http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/lbnl/rss Recent eScholarship items from Lawrence Berkeley National Laboratory Sun, 30 Aug 2026 09:52:31 +0000 https://escholarship.org/uc/item/7k45v2mn We experimentally evaluate the performance of a novel pixelated diamond sensor for non-invasive x-ray beam monitoring in the tender x-ray regime (6–30 keV). Through simulations and experiments, we assess its precision in measuring beam parameters (flux, position and size) and compare it to a scintillator re-imaging microscope, an established, invasive photon beam diagnostic. Experimental results for the pixelated diamond sensor show a position sensitivity better than 50μm-rms (on the order of the pixel size), up to &gt;100Hz feedback rates, and accurate beam size tracking. The pixelated diamond sensor, though less precise than a scintillator reimaging microscope, offers the advantage of being non-invasive and has been successfully integrated into automated alignment routines using EPICS/Bluesky instrument control framework. https://escholarship.org/uc/item/7k45v2mn Sat, 29 Aug 2026 00:00:00 +0000 Chong, Xiaoya Morris, Thomas W Forgacs, Tyler Goldberg, Kenneth A https://orcid.org/0000-0001-9984-5780 Islegen-Wojdyla, Antoine https://orcid.org/0000-0003-4321-8387 https://escholarship.org/uc/item/7f1716bf The future of synchrotron light sources will bring diffraction-limited x-ray beams, providing high brightness and coherent wavefronts to an increasing number of beamline endstations around the world. In order to engineer coherent wavefronts and harness the high power densities, we need to develop x-ray deformable mirrors that can control the wavefront with high precision (&lt; 5 nm-rms), can steer the beam at high speed (&gt; 1kHz) and be compatible with ultra-high vacuum environments. We show that deformable mirrors made on industry-grade silicon wafers, borrowing a technological platform developed for space x-ray telescopes, could potentially be used for synchrotron applications, with residual figure error of about 10nm-rms that can be actuated to cause 100nm PV local deformation and operation at frequencies up to 10kHz. We also show that we can use machine learning techniques to improve their performance in operation, reducing the effects of drift and hysteresis, and make the... https://escholarship.org/uc/item/7f1716bf Sat, 29 Aug 2026 00:00:00 +0000 Chong, Xiaoya Buffo, Kenneth M Griffin, Philip Tipsawat, Pannawit DeRoo, Casey Trolier-McKinstry, Susan Ochoa, Bryan Bryant, Diane Ericksen, Morgan Sabbah, Ali Smith, Nicolás Lacey, Ian https://orcid.org/0000-0001-5277-1067 Yashchuk, Valeriy https://orcid.org/0000-0001-7970-2862 Goldberg, Kenneth A https://orcid.org/0000-0001-9984-5780 Islegen-Wojdyla, Antoine https://orcid.org/0000-0003-4321-8387 https://escholarship.org/uc/item/6p69t0w9 The generational advances in synchrotron radiation sources have historically been bottlenecked by the optics used to focus and manipulate x-ray beamlines. Such optics have strict metrology requirements while needing to be versatile in their abundance of applications. To meet these requirements, thin adaptive optics (TAOs) have been developed to correct optical surface error and perform source wavefront shaping. These TAOs consist of a series of thin-film piezoelectric actuators deposited on a mirror substrate that induce spatially localized figure deformations. In this work, the fabrication and actuator performance of two TAO mirror segments are reported. These ∼ 0.5mm thick optics have addressable actuators whose responses were measured using Fizeau interferometry. The individual actuator responses of the two TAOs induced a figure change peak-to-valley (PV) of 183nm and 63nm on average. Finally, the TAOs were used to measure the deflection of an optical laser under operation... https://escholarship.org/uc/item/6p69t0w9 Sat, 29 Aug 2026 00:00:00 +0000 Buffo, Kenneth DeRoo, Casey Griffin, Philip Islegen-Wojdyla, Antoine https://orcid.org/0000-0003-4321-8387 Chong, Xiaoya Goldberg, Kenneth https://orcid.org/0000-0001-9984-5780 Ochoa, Bryan Trolier-McKinstry, Susan Tipsawat, Pannawit https://escholarship.org/uc/item/4kr0109n We demonstrate an experimental approach to determine magneto-optical effects that combines x-ray magnetic circular dichroism (XMCD) with x-ray interferometry, based on the concepts of Young's canonical double slit. By covering one of two slits with a magnetic thin film and employing XMCD, we show that it is possible to determine both the real and the imaginary parts of the complex refractive index by measuring the fringe shifts that occur due to a change in the sample magnetization. Our hybrid spectroscopic-interferometric methodology provides a means to probe changes in the magnetic refractive index in terms of the electron spin moment. https://escholarship.org/uc/item/4kr0109n Sat, 29 Aug 2026 00:00:00 +0000 Atkar, S Tumbleson, Z Morley, SA https://orcid.org/0000-0001-8197-2431 Burdet, N Islegen-Wojdyla, A https://orcid.org/0000-0003-4321-8387 Goldberg, KA https://orcid.org/0000-0001-9984-5780 Scholl, A Montoya, SA Datta, Trinanjan Roy, S https://escholarship.org/uc/item/3qv0q872 X-ray magnetic circular dichroism (XMCD), an experimental technique that utilizes circularly polarized light at synchrotron light sources to probe the magnetic properties of materials, is performed by taking the difference of two x-ray absorption spectroscopy (XAS) spectra with x-rays of opposite circular polarizations. Each XAS spectrum measurement requires an energy scan by rotating a diffraction grating, which takes on the order of minutes to complete. Variations in the light source beam conditions or sample material environment can occur in the time between each XAS measurement and can lead to systematic shifts and fluctuations in the collected spectra and ultimately affect the XMCD measurement. We describe a concept using adaptive optics with active feedback to enable the use of fast polarization switching with lock-in amplification to reduce these effects and increase the sensitivity of XMCD measurements, and the development of such an adaptive optics system at the Advanced... https://escholarship.org/uc/item/3qv0q872 Sat, 29 Aug 2026 00:00:00 +0000 Ho, Johnny Islegen-Wojdyla, Antoine https://orcid.org/0000-0003-4321-8387 Chong, Xiaoya Sabbah, Ali Goldberg, Kenneth A https://orcid.org/0000-0001-9984-5780 N'Diaye, Alpha T https://escholarship.org/uc/item/3dj6c87h Coherent x-ray imaging faces fundamental speed limitations due to computational reconstruction requirements of current phase retrieval methods. We demonstrate dual-beam zone plates that enable direct phase-contrast measurements by structuring coherent x-rays into two focused 110nm spots separated by 11μm, bypassing iterative algorithms entirely. Experimental validation at the COSMIC beamline confirms precise dual-beam formation with clear interference patterns analogous to Young’s double-slit experiment. Comparative measurements reveal enhanced sensitivity: phase detection achieves 45° phase shifts at sample boundaries where intensity contrast shows poor signal clarity due to noise. Spectroscopic demonstrations across the oxygen K-edge show energy-selective capabilities, with phase features providing improved signal-to-noise ratio compared to conventional absorption measurements. The high photon efficiency of this direct measurement approach enables fast imaging capabilities,... https://escholarship.org/uc/item/3dj6c87h Sat, 29 Aug 2026 00:00:00 +0000 He, Wei Islegen-Wojdyla, Antoine https://orcid.org/0000-0003-4321-8387 Ditter, Alex https://orcid.org/0000-0002-8733-1982 Basak, Rourav Chao, Weilun Burdet, Nicolas Chong, Xiaoya Gu, Chaoying Frañó, Alex Roy, Sujoy Scholl, Andreas Shapiro, David Goldberg, Kenneth https://orcid.org/0000-0001-9984-5780 https://escholarship.org/uc/item/0sb6m8r9 We present a comprehensive review of Fourier transform spectroscopy in the soft x-ray region, focusing on Mach-Zehnder interferometer configurations. This study evaluates advantages over traditional grating-based methods, including higher resolution potential (&gt;10,000) and rapid data acquisition. We examine historical implementations and their limitations, highlighting how recent advances in laser interferometry, mechanical stability, and detector technology may enable successful development. Through detailed simulations of interferometer schemes and beam splitter designs, we demonstrate how modern piezoelectric stages and feedback systems could overcome previous technical challenges. Applications for resonant inelastic x-ray scattering (RIXS) experiments at advanced light sources are discussed. https://escholarship.org/uc/item/0sb6m8r9 Sat, 29 Aug 2026 00:00:00 +0000 Lindburg, Andrew Chen, Chuzida Ding, Honghe Glans, Per-Anders Islegen-Wojdyla, Antoine https://orcid.org/0000-0003-4321-8387 White, Victor Goldberg, Kenneth A https://orcid.org/0000-0001-9984-5780 Guo, Jinghua https://orcid.org/0000-0002-8576-2172 https://escholarship.org/uc/item/9pf9n13w Crassulacean acid metabolism (CAM) is a specialized photosynthetic pathway that enhances water-use efficiency by temporally separating nocturnal CO₂ uptake from daytime decarboxylation and carbon fixation. To uncover the regulatory mechanisms coordinating these temporal dynamics, we generated high-resolution, 48 h time-course transcriptomes for the CAM model <i>Kalanchoe fedtschenkoi</i> under both 12 h/12 h light/dark (LD) cycles and continuous light (LL). A rhythmicity analysis revealed that diel light cues are the dominant driver of transcript oscillations: 16,810 genes (54.3% of annotated genes) exhibited rhythmic expression only under LD, whereas just 399 genes (1.3%) remained rhythmic under LL. A smaller set of 3009 genes (9.7%) oscillated in both conditions, indicating that the intrinsic circadian clock sustains rhythmicity for a limited subset of the transcriptome. A gene co-expression network analysis revealed extensive integration between circadian clock components,... https://escholarship.org/uc/item/9pf9n13w Fri, 28 Aug 2026 00:00:00 +0000 Hu, Rongbin Jawdy, Sara Sreedasyam, Avinash Lipzen, Anna https://orcid.org/0000-0003-2293-9329 Wang, Mei Ng, Vivian https://orcid.org/0000-0001-8941-6931 Daum, Christopher https://orcid.org/0000-0003-3895-5892 Keymanesh, Keykhosrow Liu, Degao Hu, Alex Pasha, Asher Provart, Nicholas J Borland, Anne M Tschaplinski, Timothy J Tuskan, Gerald A Schmutz, Jeremy Yang, Xiaohan https://escholarship.org/uc/item/8w76778j Most atomic nuclei exhibit ellipsoidal shapes characterized by quadrupole deformation<i>β</i>₂and triaxiality<i>γ</i>, and sometimes even a pear-like octupole deformation<i>β</i>₃. The STAR experiment introduced a new 'imaging-by-smashing' technique ((STAR Collaboration) 2024<i>Nature</i><b>635</b>67; Jia 2025<i>Rep. Prog. Phys.</i><b>88</b>092301) to image the nuclear global shape by colliding nuclei at ultra-relativistic speeds and analyzing outgoing debris. Features of nuclear shape manifest in collective observables like anisotropic flow<i>v_n</i>and radial flow via mean transverse momentum[pT]. We present new measurements of the variances of<i>v_n</i>(<i>n</i> = 2, 3, and 4) and[pT], and the covariance ofvn2with[pT], in collisions of highly deformed²³⁸U and nearly spherical¹⁹⁷Au. Ratios of these observables between the two systems effectively suppress common final-state effects, isolating the strong impact of... https://escholarship.org/uc/item/8w76778j Fri, 28 Aug 2026 00:00:00 +0000 Collaboration, The STAR https://escholarship.org/uc/item/8g19t3pn Many Rickettsia species undergo actin-based motility to promote cell-cell spread during infection. Rickettsial genomes often encode two motility effectors, RickA and Sca2, which in the spotted fever group I species, Rickettsia parkeri act by activating the host Arp2/3 complex and by mimicking eukaryotic formins, respectively. The function of RickA and Sca2 orthologs in the distantly related species Rickettsia bellii was unclear. We report that R. bellii RickA activates the host Arp2/3 complex but has no discernible role in bacterial motility. The R. bellii Sca2 ortholog, Sca2/6, nucleates and elongates actin with a flexible structure and an unusual actin monomer-binding motif in a mechanism distinct from formins or other microbial actin nucleators. R. bellii motility is solely correlated with Sca2/6 localization and, compared with R. parkeri motility, is slow and meandering, generating distinctly organized actin tails. The evolutionary flexibility in the mechanism and regulation... https://escholarship.org/uc/item/8g19t3pn Fri, 28 Aug 2026 00:00:00 +0000 Bacher, Meghan C Choe, Julie E Jiang, Jiawen Idrovo, Joanna M Del Mundo, Joshua T Hammel, Michal https://orcid.org/0000-0002-5610-9289 Welch, Matthew D https://escholarship.org/uc/item/87w3z5gj The cross-correlation of cosmic voids with the lensing convergence ( κ ) map of the Cosmic Microwave Background (CMB) fluctuations provides a powerful tool to refine our understanding of the current cosmological model. However, several studies have reported a moderate tension (up to ∼2 σ ) between the lensing imprint of cosmic voids on the observed CMB and the ΛCDM signal predicted by simulations. To address this “lensing-is-low” tension and to obtain new, precise measurements of the signal, we exploit the large DESI Legacy Survey Luminous Red Galaxy (LRG) data set, covering approximately 19 500 deg 2 of the sky and including about 10 million LRGs at z &lt; 1.05. Our ΛCDM template was created using the Buzzard mocks, which we specifically calibrated to match the clustering properties of the observed galaxy sample by exploiting more than one million DESI spectra. We identified our catalogs of 3D voids in the range 0.35 &lt; z &lt; 0.95 and cross-correlated them through a stacking... https://escholarship.org/uc/item/87w3z5gj Fri, 28 Aug 2026 00:00:00 +0000 Sartori, S Vielzeuf, P Escoffier, S Cousinou, MC Kovács, A DeRose, J Ahlen, S Bianchi, D Brooks, D Burtin, E Claybaugh, T de la Macorra, A Forero-Romero, JE Garcia-Bellido, J Gontcho, S Gontcho A Gutierrez, G Honscheid, K Kehoe, R Kirkby, D https://orcid.org/0000-0002-8828-5463 Kisner, T Landriau, M Levi, ME https://orcid.org/0000-0003-1887-1018 Meisner, A Miquel, R Moustakas, J Newman, JA Palanque-Delabrouille, N Pérez-Ràfols, I Prada, F Rossi, G Sanchez, E Sprayberry, D Tarlé, G Weaver, BA https://escholarship.org/uc/item/7f8558ms Leveraging predicted origin sequences from a previously characterized groundwater plasmidome, we constructed a barcoded plasmid library to screen for previously unknown origins. Testing this library against a panel of representative bacterial strains led to the identification of 3 previously unknown origins that replicate in gram-negative bacteria not previously associated with these origin sequences. Experimental validation confirmed that a plasmid bearing origin 6911 as the sole origin could replicate with a copy number of 9 (±2) in <i>Pantoea</i> sp. MT58, a fast growing and metal tolerant, environmentally important bacterium. Plasmids based on this new origin were used to express the reporter protein GFP, and non-native metabolite pathways for the natural product indigoidine and the terpenoid compound isoprenol. Functional previously unknown origins of replication in such non-model organisms can expand the toolkit for genetic manipulations of both model and less-studied bacteria. https://escholarship.org/uc/item/7f8558ms Fri, 28 Aug 2026 00:00:00 +0000 Codik, Alex Kothari, Ankita Liu, Hualan Weinberg, Benjamin L Owens, Trenton K Srinivasan, Aparajitha Rivier, Alex Eng, Thomas https://orcid.org/0000-0002-4974-3863 Arkin, Adam P https://orcid.org/0000-0002-4999-2931 Deutschbauer, Adam M Mukhopadhyay, Aindrila https://orcid.org/0000-0002-6513-7425 https://escholarship.org/uc/item/71h375g6 Postpolymerization functionalization of polymers can create new applications for existing materials, while retaining their most favorable, intrinsic properties. Polyvinyl chloride (PVC) is a widely used, commodity polymer that is particularly challenging to modify. We report a copper-catalyzed protocol that replaces a small fraction of the C-Cl bonds in PVC with C-B bonds to boronic esters. The reaction occurs with an inexpensive catalyst comprising copper(II) chloride and an NHC ligand derived from a common ionic liquid that is distinct from the N-heterocyclic carbene (NHC) used for the borylation of small alkyl halides. The resulting materials adhere strongly to common surfaces, such as glass and metals, even more strongly than do commercial glues. https://escholarship.org/uc/item/71h375g6 Fri, 28 Aug 2026 00:00:00 +0000 D’Angelo, Kyan A Sun, Nathan Ciccia, Nicodemo R Yu, Isaac F Helms, Brett A https://orcid.org/0000-0003-3925-4174 Hartwig, John F https://escholarship.org/uc/item/6x99n0cg The first measurement of the pair production at midrapidity and low invariant mass in central Pb-Pb collisions at at the Large Hadron Collider is presented. The yield of pairs is compared with a cocktail of expected hadronic decay contributions in the invariant mass ( ) and pair transverse momentum ( ) ranges and . For the ratio of data to the cocktail of hadronic contributions amounts to and , including or not including medium effects in the estimation of the heavy-flavor background, respectively. It is consistent with predictions from two different models for an additional contribution of thermal pairs from the hadronic and partonic phases. In the intermediate-mass range ( ), the pair transverse impact parameter of the pairs ( , where “DCA” denotes “distance of closest approach”) is used for the first time in Pb-Pb collisions to separate displaced dielectrons from heavy-flavor hadron decays from a possible (thermal) contribution produced at the interaction point.... https://escholarship.org/uc/item/6x99n0cg Fri, 28 Aug 2026 00:00:00 +0000 Acharya, S Adamová, D Rinella, G Aglieri Agnello, M Agrawal, N Ahammed, Z Ahmad, S Ahn, SU Ahuja, I Akindinov, A Al-Turany, M Aleksandrov, D Alessandro, B Alfanda, HM Molina, R Alfaro Ali, B Alici, A Alizadehvandchali, N Alkin, A Alme, J Alocco, G Alt, T Altamura, AR Altsybeev, I Alvarado, JR Anaam, MN Andrei, C Andreou, N Andronic, A Anguelov, V Antinori, F Antonioli, P Apadula, N Aphecetche, L Appelshäuser, H Arata, C Arcelli, S Aresti, M Arnaldi, R Arneiro, JGMCA Arsene, IC Arslandok, M Augustinus, A Averbeck, R Azmi, MD Baba, H Badalà, A Bae, J Baek, YW Bai, X Bailhache, R Bailung, Y Balbino, A Baldisseri, A Balis, B Banerjee, D Banoo, Z Barbera, R Barile, F Barioglio, L Barlou, M Barman, B Barnaföldi, GG Barnby, LS Barret, V Barreto, L Bartels, C Barth, K Bartsch, E Bastid, N Basu, S Batigne, G Battistini, D Batyunya, B Bauri, D Alba, JL Bazo Bearden, IG Beattie, C Becht, P Behera, D Belikov, I Hechavarria, ADC Bell Bellini, F Bellwied, R Belokurova, S Beltran, YAV Bencedi, G Beole, S Berdnikov, Y Berdnikova, A Bergmann, L Besoiu, MG Betev, L Bhaduri, PP Bhasin, A Bhat, MA Bhattacharjee, B Bianchi, L Bianchi, N Bielčík, J https://escholarship.org/uc/item/6jw731z7 Retrofitting central HVAC systems in large commercial buildings with advanced technologies like heat recovery chillers (HRCs) offers a significant opportunity to enhance energy efficiency. However, analyzing these retrofits is challenging with traditional whole-building simulation tools, which require intensive calibration and struggle to model innovative system configurations and controls. To overcome these limitations, this study proposes a load profilebased retrofit analysis framework that provides better decisions under uncertainty. The main focus of this paper is the development of a probabilistic load profile model that can be used in the framework by using exploratory data analysis (EDA) of measured building data to properly quantify its inherent variability. A non-parametric Gaussian Process (GP) model was employed to capture the time- and weather-dependent characteristics of the heating load while explicitly modeling its uncertainty. The model's effectiveness is demonstrated... https://escholarship.org/uc/item/6jw731z7 Fri, 28 Aug 2026 00:00:00 +0000 Ham, SW https://orcid.org/0000-0003-1776-2610 Excell, L Kim, D https://orcid.org/0000-0002-1868-6341 https://escholarship.org/uc/item/69b358rz Although the green revolution adapted a handful of crops to homogeneous and high-input industrialized agriculture, much of the global population still relies on the local production of variable crop cultivars by low-input smallholder farms. This diversity of unhomogenized crops1, like that of the grain and bioenergy crop sorghum2, 3, 4–5, offers raw materials for genetic gain and cultivar improvement. However, breeding efforts can be constrained by highly specialized traits and breeding targets6. Here, to bridge this diversity, we constructed a 33-member pangenome reference and a diversity panel across 1,984 cultivars and landraces. We leveraged these resources to explore the complex interplay among historical contingency, ongoing adaptation and previously uncharacterized structural diversity. Specifically, our analyses conclusively demonstrated multiple nested and deeply diverged structural variants in the domestication gene SHATTERING1, which distinguish the previously established... https://escholarship.org/uc/item/69b358rz Fri, 28 Aug 2026 00:00:00 +0000 Morris, Geoffrey P Harder, Avril M Healey, Adam L McLaughlin, Chloee M Rifkin, Joanna L Cruet-Burgos, Clara Jenkins, Jerry W Shu, Shengqiang Spiekerman, John J VanGessel, Carl J Agnew, Erica Audebert, Alain Barry, Kerrie https://orcid.org/0000-0002-8999-6785 Baxter, Ivan Beurier, Gregory Boston, Lori Beth Boyles, Richard E Brady, Siobhan M https://orcid.org/0000-0001-9424-8055 Bunting, Victoria Chaparro, Jacqueline M Courtney, Chaney Dembele, Joseph Sékou B Deshpande, Santosh Diatta, Cyril Eck, Nathaniel Eveland, Andrea L Faye, Jacques M Flowers, Dave Fonceka, Daniel Gano, Boubacar de Gracia Coquerel, Marie Goodstein, David Grimwood, Jane Hudson, Matthew E Kholova, Jana Johnson, Katherine Johnson, Kristen K Kawa, Dorota Kouressy, Mamoutou Kresovich, Stephen Lee, Scott Lemaux, Peggy G Lowery, Robert Luquet, Delphine Maina, Fanna Mamidi, Sujan McKay, John K Michael, Todd P https://orcid.org/0000-0001-6272-2875 Mindaye, Taye T Mullet, John Ozersky, Philip Plott, Christopher Prenni, Jessica E Pressoir, Gael Rami, Jean-François Rife, Trevor W Saxton, Jocelyn Sine, Bassirou Sreedasyam, Avinash Talag, Jayson Teme, Niaba Tuinstra, Mitchell R Vadez, Vincent Vogel, John P https://orcid.org/0000-0003-1786-2689 Walstead, Rachel Wang, Jianan Webber, Jenell Williams, Melissa Xu, Yuxing Mockler, Todd C Lasky, Jesse R Rice, Brian R Schmutz, Jeremy Shakoor, Nadia Lovell, John T https://escholarship.org/uc/item/6722d4zv Correction to: Scientific Datahttps://doi.org/10.1038/s41597-024-03319-8, published online 23 May 2024 In this article the author’s name Marcelo Salles Olinger was incorrectly given as Marcello Salles Olinger. The original article has been corrected. https://escholarship.org/uc/item/6722d4zv Fri, 28 Aug 2026 00:00:00 +0000 Machard, Anaïs Salvati, Agnese P. Tootkaboni, Mamak Gaur, Abhishek Zou, Jiwei Wang, Liangzhu Leon Baba, Fuad Ge, Hua Bre, Facundo Bozonnet, Emmanuel Corrado, Vincenzo Luo, Xuan Levinson, Ronnen https://orcid.org/0000-0003-1463-1359 Lee, Sang Hoon Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Salles Olinger, Marcelo Machado, Rayner Maurício E Silva da Guarda, Emeli Lalesca Aparecida Veiga, Rodolfo Kirch Lamberts, Roberto Afshari, Afshin Ramon, Delphine Ngoc Dung Ngo, Hoang Sengupta, Abantika Breesch, Hilde Heijmans, Nicolas Deltour, Jade Kuborn, Xavier Sayadi, Sana Qian, Bin Zhang, Chen Rahif, Ramin Attia, Shady Stern, Philipp Holzer, Peter https://escholarship.org/uc/item/5vt5n573 Geometrically frustrated lattices can display a range of correlated phenomena, ranging from spin frustration and charge order to dispersionless flat bands due to quantum interference. One particularly compelling family of such materials is the half-valence spinel LiB2O4 materials. On the B-site frustrated pyrochlore sublattice, the interplay of correlated metallic behavior and charge frustration leads to a superconducting state in LiTi2O4 and heavy fermion behavior in LiV2O4. To date, however, LiTi2O4 has primarily been understood as a conventional BCS superconductor despite a lattice structure that could host more exotic ground states. Here, we present a multimodal investigation of LiTi2O4, combining ARPES, RIXS, proximate magnetic probes, and ab-initio many-body theoretical calculations. Our data reveals a novel mobile polaronic ground state with spectroscopic signatures that underlie co-dominant electron-phonon coupling and electron-electron correlations also found in the lightly... https://escholarship.org/uc/item/5vt5n573 Fri, 28 Aug 2026 00:00:00 +0000 Hasan, Zubia Pan, Grace A LaBollita, Harrison Kaczmarek, Austin Sung, Suk Hyun Sharma, Shekhar Balakrishnan, Purnima P Mercer, Edward Bhartiya, Vivek N’Diaye, Alpha T Salman, Zaher Prokscha, Thomas Suter, Andreas Grutter, Alexander J Garcia-Fernandez, Mirian Zhou, Ke-Jin Pelliciari, Jonathan Bisogni, Valentina El Baggari, Ismail Schlom, Darrell G Barone, Matthew R Brooks, Charles M Nowack, Katja C Botana, Antia S Faeth, Brendan D de la Torre, Alberto Mundy, Julia A https://escholarship.org/uc/item/5sc7s3w2 Transmission electron microscopy (TEM) continues to transform polymer science by revealing key aspects of chain packing, phase separation and nanoscale structure. The development of instrumentation and data analyses tools is driving the field forward and enabling new experiments. Here, we use automated high-resolution TEM (HRTEM) and image processing to identify the structure of a conjugated polymer used in organic electronics. Analysis of more than 600 HRTEM images reveals lattice parameters and orientation correlations between crystals, including the preferred alignment of neighboring crystals along the same crystallographic direction that is likely the result of liquid crystalline order. https://escholarship.org/uc/item/5sc7s3w2 Fri, 28 Aug 2026 00:00:00 +0000 Fair, Ryan A Gamdha, Dhruv Del Mundo, Joshua T Fenton, Abigail M O’Connell, Agatha Bustillo, Karen C https://orcid.org/0000-0002-2096-6078 Gomez, Esther W Minor, Andrew M https://orcid.org/0000-0003-3606-8309 Ganapathysubramanian, Baskar Gomez, Enrique D https://escholarship.org/uc/item/5ms743n4 Retrofitting existing central plants with high-efficiency heat pump technologies can play a crucial role in achieving long-term planning goals. Modern heat pump technologies are able to use waste heat recovery to meet a building's heating demand, but there is a lack of accessible tools designed for non-HVAC experts, such as building owners, to quickly and easily conduct what-if analysis, e.g., estimating retrofit costs and payback period for their partial or full equipment replacement. This paper introduces an open-source software toolkit designed to facilitate the initial screening and decision-making of heat pump retrofits in existing central plants using a building's yearly load profile from metered or utility bill data. The toolkit evaluates the technical and economic viability of replacing traditional central plant equipment with various options including water-to-water or air-to-water heat pumps, which can provide efficient and lower-cost heating and cooling. It allows users... https://escholarship.org/uc/item/5ms743n4 Fri, 28 Aug 2026 00:00:00 +0000 Excell, L Anderson, I Breda, J Ham, SW https://orcid.org/0000-0003-1776-2610 White, G Kim, D https://orcid.org/0000-0002-1868-6341 https://escholarship.org/uc/item/4zz9t5tf Polyhydroxyalkanoates (PHAs) are widespread microbial storage polymers increasingly recognized for roles beyond carbon and energy storage, including redox homeostasis and stress physiology. While PHA accumulation is classically associated with stationary-phase metabolism under severe nutrient imbalance, comparatively little is known about growth-associated PHA synthesis in facultative anaerobes with unusual respiratory strategies. Here, we investigated polyhydroxybutyrate (PHB) metabolism in <i>Azospira suillum</i> PS, a genetically tractable perchlorate-reducing bacterium capable of both aerobic and anaerobic respiration. Using physiological growth experiments, targeted gene deletions, PHB extractions, and intracellular redox measurements, we examined PHB accumulation under varying respiratory and nutrient conditions. We demonstrate that PHB accumulates during exponential growth under moderately nitrogen-limited conditions, both aerobically and during perchlorate respiration,... https://escholarship.org/uc/item/4zz9t5tf Fri, 28 Aug 2026 00:00:00 +0000 Meier, David AO Glazer, Benjamin Lanclos, V Celeste Carlson, Hans K https://orcid.org/0000-0002-1583-5313 Coates, John D https://escholarship.org/uc/item/4qm7z40s Solid-state synthesis involves a web of coupled chemical reactions and physical changes that unfold across multiple scales. Efforts to fine-tune its parameters have historically followed heuristic, trial-driven workflows that demand significant time and resources. In this study, we aimed to open this black box by employing multiscale in situ synchrotron imaging and diffraction. Using LiNi0.5Mn0.3Co0.2O2 battery positive electrode material as a model system and Ba-based sintering aids, we reveal dopant segregation, intergranular mass transport, and porosity evolution as key drivers of single-crystalline particle formation. Notably, we uncovered a dynamic competition between particle-level grain coalescence and atomic-scale cation disordering, both of which are thermally activated yet have opposing impacts on battery performance. These findings highlight the coupled, multiscale nature of structure development and offer a mechanistic basis for optimizing the solid-state synthesis... https://escholarship.org/uc/item/4qm7z40s Fri, 28 Aug 2026 00:00:00 +0000 Xue, Zhichen Sun, Tianxiao Oruganti, Sreevishnu Huang, Xiaojing Parkinson, Dilworth Y https://orcid.org/0000-0002-1817-0716 Chu, Yong S Pianetta, Piero Ge, Mingyuan Liu, Yijin https://escholarship.org/uc/item/4kv3q3rz Heavy-flavor quarks produced in proton-proton (pp) collisions provide a unique opportunity to investigate the evolution of quark-initiated parton showers from initial hard scatterings to final-state hadrons. By examining jets that contain heavy-flavor hadrons, this study explores the effects of both perturbative and nonperturbative QCD on jet formation and structure. The angular differences between various jet axes, , offer insight into the radiation patterns and fragmentation of charm quarks. The first measurement of -tagged jet axes differences in pp collisions at by the ALICE experiment at the LHC is presented for jets with transverse momentum and mesons with . In this -meson-tagged jet measurement, three jet axis definitions, each with different sensitivities to soft, wide-angle radiation, are used: the standard axis, soft drop groomed axis, and winner-takes-all axis. Measurements of the radial distributions of mesons with respect to the jet axes, , are reported,... https://escholarship.org/uc/item/4kv3q3rz Fri, 28 Aug 2026 00:00:00 +0000 Acharya, S Agarwal, A Rinella, G Aglieri Aglietta, L Agnello, M Agrawal, N Ahammed, Z Ahmad, S Ahn, SU Ahuja, I Akindinov, A Akishina, V Al-Turany, M Aleksandrov, D Alessandro, B Alfanda, HM Molina, R Alfaro Ali, B Alici, A Alizadehvandchali, N Alkin, A Alme, J Alocco, G Alt, T Altamura, AR Altsybeev, I Alvarado, JR Anaam, MN Andrei, C Andreou, N Andronic, A Andronov, E Anguelov, V Antinori, F Antonioli, P Apadula, N Appelshäuser, H Arata, C Arcelli, S Arnaldi, R Arneiro, JGMCA Arsene, IC Arslandok, M Augustinus, A Averbeck, R Averyanov, D Azmi, MD Baba, H Badalà, A Bae, J Bae, Y Baek, YW Bai, X Bailhache, R Bailung, Y Bala, R Baldisseri, A Balis, B Bangalia, S Banoo, Z Barbasova, V Barile, F Barioglio, L Barlou, M Barman, B Barnaföldi, GG Barnby, LS Barreau, E Barret, V Barreto, L Barth, K Bartsch, E Bastid, N Basu, S Batigne, G Battistini, D Batyunya, B Bauri, D Alba, JL Bazo Bearden, IG Becht, P Behera, D Belikov, I Hechavarria, ADC Bell Bellini, F Bellwied, R Belokurova, S Beltran, LGE Beltran, YAV Bencedi, G Bensaoula, A Beole, S Berdnikov, Y Berdnikova, A Bergmann, L Bernardinis, L Betev, L Bhaduri, PP Bhalla, T Bhasin, A https://escholarship.org/uc/item/47n2269p We present the measurement of the -differential production cross section&nbsp;of mesons in and -Pb collisions at TeV at midrapidity by ALICE. In addition, the first measurement of the nuclear modification factor for mesons at LHC energies is presented, complementing the existing measurements of lighter neutral mesons such as the and . Within the measured range, the of mesons is compatible with no cold nuclear matter effects within the uncertainties, consistent with previous measurements at lower energies. The ratio is presented for both collision systems, showing no collision system dependence within the uncertainties. The comparison to previously published ratios at lower and higher collision energies in collisions suggests a decreasing trend of the ratio above = 4 GeV/ with increasing collision energy. The data in both collision systems are compared to predictions from PYTHIA 8, EPOS LHC, and DPMJET event generators, revealing significant shortcomings in these... https://escholarship.org/uc/item/47n2269p Fri, 28 Aug 2026 00:00:00 +0000 Acharya, S Agarwal, A Rinella, G Aglieri Aglietta, L Agnello, M Agrawal, N Ahammed, Z Ahmad, S Ahn, SU Ahuja, I Akindinov, A Akishina, V Al-Turany, M Aleksandrov, D Alessandro, B Alfanda, HM Molina, R Alfaro Ali, B Alici, A Alizadehvandchali, N Alkin, A Alme, J Alocco, G Alt, T Altamura, AR Altsybeev, I Alvarado, JR Anaam, MN Andrei, C Andreou, N Andronic, A Andronov, E Anguelov, V Antinori, F Antonioli, P Apadula, N Appelshäuser, H Arata, C Arcelli, S Arnaldi, R Arneiro, JGMCA Arsene, IC Arslandok, M Augustinus, A Averbeck, R Averyanov, D Azmi, MD Baba, H Badalà, A Bae, J Bae, Y Baek, YW Bai, X Bailhache, R Bailung, Y Bala, R Baldisseri, A Balis, B Bangalia, S Banoo, Z Barbasova, V Barile, F Barioglio, L Barlou, M Barman, B Barnaföldi, GG Barnby, LS Barreau, E Barret, V Barreto, L Barth, K Bartsch, E Bastid, N Basu, S Batigne, G Battistini, D Batyunya, B Bauri, D Alba, JL Bazo Bearden, IG Becht, P Behera, D Belikov, I Hechavarria, ADC Bell Bellini, F Bellwied, R Belokurova, S Beltran, LGE Beltran, YAV Bencedi, G Bensaoula, A Beole, S Berdnikov, Y Berdnikova, A Bergmann, L Bernardinis, L Betev, L Bhaduri, PP Bhasin, A Bhattacharjee, B https://escholarship.org/uc/item/47j4k2gt The powerful jets of blazars have been historically considered as likely sites of high-energy cosmic-ray acceleration. However, the particulars of the launched jet and the locations of leptonic and hadronic jet loading remain unclear. In the case when leptonic and hadronic particle injection occur jointly, a temporal correlation between synchrotron radiation and neutrino production is expected. We use a first catalog of millimeter wavelength (95–225 GHz) blazar light curves from the Atacama Cosmology Telescope for a time-dependent correlation with 12 yr of muon neutrino events from the IceCube South Pole Neutrino Observatory. Such millimeter emission traces activity of the bright jet base, which is often self-absorbed at lower frequencies and potentially gamma-ray opaque. We perform an analysis of the population, as well as analyses of individual, selected sources. We do not observe a significant signal from the stacked population. TXS 0506+056 is found as the most significant,... https://escholarship.org/uc/item/47j4k2gt Fri, 28 Aug 2026 00:00:00 +0000 Abbasi, R Ackermann, M Adams, J Agarwalla, SK Aguilar, JA Ahlers, M Alameddine, JM Amin, NM Andeen, K Argüelles, C Ashida, Y Athanasiadou, S Axani, SN Babu, R Bai, X Baines-Holmes, J V., A Balagopal Barwick, SW https://orcid.org/0000-0003-2050-6714 Bash, S Basu, V Bay, R Beatty, JJ Tjus, J Becker Behrens, P Beise, J Bellenghi, C Benkel, B BenZvi, S Berley, D Bernardini, E Besson, DZ Blaufuss, E Bloom, L Blot, S Bodo, I Bontempo, F Motzkin, JY Book Meneguolo, C Boscolo Böser, S Botner, O Böttcher, J Braun, J Brinson, B Brisson-Tsavoussis, Z Burley, RT Butterfield, D Campana, MA Carloni, K Carpio, J Chattopadhyay, S Chau, N Chen, Z Chirkin, D Choi, S Clark, BA Coleman, A Coleman, P Collin, GH Connolly, A Conrad, JM Corley, R Cowen, DF De Clercq, C DeLaunay, JJ Delgado, D Delmeulle, T Deng, S Desiati, P de Vries, KD de Wasseige, G DeYoung, T Díaz-Vélez, JC DiKerby, S Dittmer, M Domi, A Draper, L Dueser, L Durnford, D Dutta, K DuVernois, MA Ehrhardt, T Eidenschink, L Eimer, A Eller, P Ellinger, E Elsässer, D Engel, R Erpenbeck, H Esmail, W Eulig, S Evans, J Evenson, PA Fan, KL Fang, K Farrag, K Fazely, AR Fedynitch, A Feigl, N Finley, C Fischer, L https://escholarship.org/uc/item/46d065bv Mycobacterium tuberculosis (Mtb) is a human bacterial pathogen that establishes chronic infection in the lung. Although the genome of Mtb was sequenced nearly 25 years ago, the genetic basis of Mtb's success as a human pathogen remains to be fully elucidated. Large-scale mutation-based genetic approaches to understanding gene function are hindered by the limited throughput of traditional transposon sequencing strategies used in mycobacteria. To create a resource for determining the function of genes, we generated a pooled random barcode transposon-site sequencing (RB-TnSeq) library in Mtb. A unique 20-nucleotide barcode in the transposon allows for rapid, high-throughput genetic screening without the laborious protocol of standard bacterial TnSeq screens. We performed 95 RB-TnSeq screens on an array of carbon sources, nitrogen sources, stressors, and antibiotics. Using the resulting dataset, we examined phenotypes of pe and ppe genes, a mycobacterial gene family whose function... https://escholarship.org/uc/item/46d065bv Fri, 28 Aug 2026 00:00:00 +0000 Dinshaw, Kayla M Lien, Katie A Knight, Matthew Ouonkap, Sorel V Yimga Liu, Hualan Savage, David F Carlson, Hans K https://orcid.org/0000-0002-1583-5313 Deutschbauer, Adam M Stanley, Sarah A https://escholarship.org/uc/item/3w91z93v The mechanics of fracture healing in calcite remain poorly constrained yet are fundamental to managing fluid transport in geothermal reservoirs and hydrocarbon systems. Here, we apply microfocused synchrotron Laue X-ray diffraction and infrared spectroscopy to investigate subcritical crack healing in a 1 mm-thick calcite crystal subjected to controlled loading in a double-torsion device. Over a 44-hour period following load removal, we map the evolution of residual strain fields surrounding the crack tip and observe a progressive increase in compressive strain perpendicular to the crack plane accompanied by infrared spectroscopic signatures that reveal enhanced accumulation of water at the healed interface. The correlation between strain evolution and surface chemistry suggests that spontaneous crack healing in calcite is driven by dynamic anelastic relaxation coupled with irreversible fluid-mineral interactions. These findings offer insight into time-dependent crack closure processes... https://escholarship.org/uc/item/3w91z93v Fri, 28 Aug 2026 00:00:00 +0000 Devoe, Michelle P. Lisabeth, Harrison Nakagawa, Seiji https://orcid.org/0000-0002-9347-0903 Hao, Zhao https://orcid.org/0000-0003-0677-8529 Tamura, Nobumichi https://orcid.org/0000-0002-3698-2611 Wenk, Hans-Rudolf https://escholarship.org/uc/item/3w5961bx The rapid deployment of direct air capture and storage (DACS) is critical for achieving emission targets, necessitating precise evaluation of the scale and cost of carbon dioxide removal. This study examines the availability of land, electricity generation, and geologic CO₂ storage within the United States, estimating a technical potential for low-temperature, adsorbent-based DACS to remove approximately 9 gigatonnes of CO₂ annually. By 2050, a substantial portion of this removal could be achieved at net-removed costs below $300/tonneCO₂, though costs are highly variable depending on factors such as facility scale, construction expenses, climate-dependent productivity and heating efficiency, and geologic storage conditions. In the short term, DACS deployment will help identify key research priorities for advancing technology and reducing removal costs. Concurrently, there is an urgent need for scientifically robust and standardized frameworks for... https://escholarship.org/uc/item/3w5961bx Fri, 28 Aug 2026 00:00:00 +0000 Hunter-Sellars, Elwin Dai, Tao https://orcid.org/0000-0002-7646-5774 Ellebracht, Nathan C Pilorgé, Hélène Pisciotta, Maxwell Bump, Alexander P Calzado, Edna Rodriguez Hovorka, Susan D Scown, Corinne D https://orcid.org/0000-0003-2078-1126 Pang, Simon H https://escholarship.org/uc/item/30k4075r The response of microbial communities that regulate belowground carbon turnover to climate change drivers in peatlands is poorly understood. Here, we leverage a whole ecosystem warming experiment to elucidate the key processes of terminal carbon decomposition and community responses to temperature rise. Our dataset of 697 metagenome-assembled genomes (MAGs) represents the microbial community from the surface (10 cm) to 2 m deep into the peat column, with only 3.7% of genomes overlapping with other well-studied peatlands. Community composition has yet to show a significant response to warming after 3 years, suggesting that metabolically diverse soil microbial communities are resistant to climate change. Surprisingly, abundant and active methanogens in the genus Candidatus Methanoflorens, Methanobacterium, and Methanoregula show the potential for both acetoclastic and hydrogenotrophic methanogenesis. Nonetheless, the predominant pathways for anaerobic carbon decomposition include... https://escholarship.org/uc/item/30k4075r Fri, 28 Aug 2026 00:00:00 +0000 Duchesneau, Katherine Aldeguer-Riquelme, Borja Petro, Caitlin Makke, Ghiwa Green, Madison Tfaily, Malak Wilson, Rachel Roth, Spencer W Johnston, Eric R Kluber, Laurel A Schadt, Christopher W Trejo, Jesse B Callister, Stephen J Purvine, Samuel O Chanton, Jeffrey P Hanson, Paul J Tringe, Susannah https://orcid.org/0000-0001-6479-8427 Eloe-Fadrosh, Emiley https://orcid.org/0000-0002-8162-1276 Glavina del Rio, Tijana Konstantinidis, Konstantinos T Kostka, Joel E https://escholarship.org/uc/item/2pk772ns Constraints on Wilson coefficients (WCs) corresponding to dimension-6 operators of the standard model effective field theory (SMEFT) are determined from a simultaneous fit to seven sets of CMS measurements probing Higgs boson, electroweak vector boson, top quark, and multijet production. Measurements of electroweak precision observables are also included and provide complementary constraints to those from the CMS experiment. The CMS measurements, using LHC proton-proton collision data at s=13Te$$\sqrt{s}=13\,\text {Te}\text {V} $$, corresponding to integrated luminosities of 36.3 or 138fb-1$$\,\text {fb}^{-1}$$, are chosen to provide sensitivity to a broad set of operators, for which consistent SMEFT predictions can be derived. These are primarily measurements of differential cross sections which are parameterized as functions of the WCs. In measurements targeting t(t¯)X$${\text {t}} (\bar{\textrm{t}})\text {X} $$ production, SMEFT effects are modelled at the detector level. Individual... https://escholarship.org/uc/item/2pk772ns Fri, 28 Aug 2026 00:00:00 +0000 Chekhovsky, V Hayrapetyan, A Makarenko, V Tumasyan, A Adam, W Andrejkovic, JW Benato, L Bergauer, T Damanakis, K Dragicevic, M Giordano, C Hussain, PS Jeitler, M Krammer, N Li, A Liko, D Mikulec, I Schieck, J Schöfbeck, R Schwarz, D Sonawane, M Waltenberger, W Wulz, C-E Janssen, T Kwon, H Van Laer, T Van Mechelen, P Bierkens, J Breugelmans, N D’Hondt, J Dansana, S De Moor, A Delcourt, M Heyen, F Hong, Y Lowette, S Makarenko, I Müller, D Tavernier, S Tytgat, M Van Onsem, GP Van Putte, S Vannerom, D Bilin, B Clerbaux, B Das, AK De Bruyn, I De Lentdecker, G Evard, H Favart, L Gianneios, P Khalilzadeh, A Khan, FA Malara, A Shahzad, MA Thomas, L Bemden, M Vanden Vander Velde, C Vanlaer, P Zhang, F De Coen, M Dobur, D Gokbulut, G Knolle, J Lambrecht, L Marckx, D Skovpen, K Van Den Bossche, N van der Linden, J Vandenbroeck, J Wezenbeek, L Bein, S Benecke, A Bethani, A Bruno, G Cappati, A De Jeneret, J De Favereau Delaere, C Giammanco, A Guzel, AO Jain Lemaitre, V Lidrych, J Mastrapasqua, P Turkcapar, S Alves, GA Coelho, E Silva, G Correia Hensel, C De Oliveira, T Menezes Herrera, C Mora Teles, P Rebello Soeiro, M Manganote, EJ Tonelli Pereira, A Vilela Júnior, WL Aldá Filho, M Barroso Ferreira Malbouisson, H Brandao Carvalho, W Chinellato, J https://escholarship.org/uc/item/2698d2ds We present a high-throughput experimental investigation of the phase behavior in triblock copolymers (PS-<i>b</i>-PB-<i>b</i>-PS and PS-<i>b</i>-PI-<i>b</i>-PS) and polystyrene (PS) homopolymer blends as a function of homopolymer molecular weight (MW) and blend ratio. Using a robotic thin-film processing platform (NOVA) integrated with Grazing Incidence Small-Angle X-ray Scattering (GISAXS) and Atomic Force Microscopy (AFM), we systematically mapped the order-disorder transition (ODT) boundaries and domain spacing evolution across a broad MW range (4.0-101.3 kDa) with varying homopolymer loadings (10% to 90%). The results reveal three distinct regimes: low-MW homopolymers, corresponding to the wet-brush regime produced only gradual domain swelling before disordering at high blend ratios (weight fraction); medium-MW homopolymers, corresponding to thedry-brush regime induced significant domain spacing increase up to 80% followed by earlier disordering, while high-MW homopolymers... https://escholarship.org/uc/item/2698d2ds Fri, 28 Aug 2026 00:00:00 +0000 Upreti, Saroj Xu, Lan Moniruzzaman, Md Wang, Yunfei Adhikari, Kailash Baral, Sabin Patton, Derek Ma, Boran Xu, Jie Li, Ruipeng Zhu, Chenhui https://orcid.org/0000-0003-1263-5065 Xia, Wenjie Gu, Xiaodan https://escholarship.org/uc/item/1kz0j2x7 Antiviral immune systems diversify by integrating new genes into existing pathways, creating new mechanisms of viral resistance. We identified genes encoding a predicted nuclease paired with a trypsin-like protease repeatedly acquired by multiple, otherwise unrelated antiviral immune systems in bacteria. Cell-based and biochemical assays revealed that the nuclease is a proenzyme that cleaves DNA only after activation by its partner protease. Two distinct immune systems, Hachiman and AVAST (antiviral adenosine triphosphatase/nucleoside triphosphatase of the STAND superfamily, Avs), use the same mechanism of proteolytic activation despite their independent evolutionary origins. Examination of nuclease-protease inheritance patterns identified caspase-nuclease (<i>canu</i>) genomic loci that confer antiviral defense in a pathway reminiscent of eukaryotic caspase activation. These results uncover the coordinated activities of pronucleases and their activating proteases within different... https://escholarship.org/uc/item/1kz0j2x7 Fri, 28 Aug 2026 00:00:00 +0000 Tuck, Owen T Hu, Jason J Lopez, Santiago C Adler, Benjamin A O’Brien, Claire E Hsieh, Kendall Meredith, Charlotte Loi, Kenneth J Yoon, Peter H Doherty, Erin E https://orcid.org/0000-0002-1555-4124 Lahiri, Arushi Doudna, Jennifer A https://escholarship.org/uc/item/1dt8b375 Electronic flat bands associated with quenched kinetic energy and heavy electron mass have attracted great interest for promoting strong electronic correlations and emergent phenomena such as high-temperature charge fractionalization and superconductivity. Intense experimental and theoretical research has been devoted to establishing the rich nontrivial metallic and heavy fermion phases intertwined with such localized electronic states. Here, we investigate the transition metal oxide spinel LiV₂O₄, an enigmatic heavy fermion compound lacking localized <i>f</i> orbital states. We use angle-resolved photoemission spectroscopy and dynamical mean-field theory to reveal a kind of correlation-induced flat band with suppressed interatomic electron hopping arising from intra-atomic Hund's coupling. The appearance of heavy quasiparticles is ascribed to a proximate orbital-selective Mott state characterized by fluctuating local moments as evidenced by complementary... https://escholarship.org/uc/item/1dt8b375 Fri, 28 Aug 2026 00:00:00 +0000 Oh, Dongjin Hampel, Alexander Wakefield, Joshua P Moen, Peter C Smit, Steef Luo, Xiangyu Zonno, Marta Gorovikov, Sergey Leandersson, Mats Polley, Craig Kundu, Asish K Rajapitamahuni, Anil Vescovo, Elio Jozwiak, Chris Bostwick, Aaron https://orcid.org/0000-0002-9008-2980 Rotenberg, Eli https://orcid.org/0000-0002-3979-8844 Isobe, Masahiko Verma, Manish Crispino, Matteo Grundner, Martin Kugler, Fabian B Parcollet, Olivier Schollwöck, Ulrich Takagi, Hidenori Damascelli, Andrea Sangiovanni, Giorgio Checkelsky, Joseph G Georges, Antoine Comin, Riccardo https://escholarship.org/uc/item/12c2491k Diamine functionalization of the metal-organic framework Mg₂(dobpdc) (dobpdc^4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) significantly enhances its selectivity for CO₂ capture from flue gases and air. The structure and CO₂ capacity of such materials are typically assessed using bulk techniques that rely on averaging signal over large ensembles of unit cells, obscuring local heterogeneities, such as variations in CO₂ occupancy across individual nanocrystals. To resolve this limitation, we demonstrate a multimodal, nanoscale characterization of Mg₂(dobpdc) appended with 1,3-diaminopropane. By employing recently developed characterization techniques at progressively smaller length scales, we uncover insights from correspondingly smaller populations of unit cells. First, we use parallel-beam 3D electron diffraction (3D ED) to identify a prominent expansion in lattice parameters upon desorption of CO₂, as... https://escholarship.org/uc/item/12c2491k Fri, 28 Aug 2026 00:00:00 +0000 Karstens, SarahL Dods, Matthew N https://orcid.org/0000-0003-2828-7376 Saha, Ambarneil https://orcid.org/0000-0002-6548-5403 Garai, Máté Dai, William Graf, Katerina I Klein, Ryan A Jiang, Henry ZH Cho, Jung Bustillo, Karen C https://orcid.org/0000-0002-2096-6078 Raschke, Markus B Ercius, Peter https://orcid.org/0000-0002-6762-9976 Long, Jeffrey R https://orcid.org/0000-0002-5324-1321 Minor, Andrew M https://orcid.org/0000-0003-3606-8309 https://escholarship.org/uc/item/92r451mq The beautification of urban facades in China often includes covers for the outdoor units of air conditioners. Although these covers improve cityscapes, they reduce cooling efficiency, increase noise pollution, risk system failures and embody carbon emissions. A call urges rethinking their necessity, and presses for sustainable, efficient design to counteract extreme heat. https://escholarship.org/uc/item/92r451mq Thu, 27 Aug 2026 00:00:00 +0000 Wang, Wei Deng, Yuwen Wu, Jiyuan Wang, Zhe Wei, Hailu Hu, Qinran Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Qian, Tao https://escholarship.org/uc/item/7jh4s386 Heat pumps account for a significant portion of electricity consumption in buildings, making their energy efficiency a critical area of research. Control optimization is recognized as an effective approach for enhancing the efficiency of building HVAC systems. Specifically, since the efficiency of heat pumps increases with reduced superheat and the optimal refrigerant charge level varies with operating conditions, zero-superheat active charge control is a promising strategy to maximize the system’s COP. However, due to its complexity, this control strategy remains in the research phase and has only been tested under limited operating conditions. This paper proposes a methodology to evaluate the seasonal performance improvement of zero-superheat active charge control across a full range of heating conditions in buildings. The methodology includes the development of an optimal controller that utilizes an accumulator to store excess refrigerant and manages the active charge level... https://escholarship.org/uc/item/7jh4s386 Thu, 27 Aug 2026 00:00:00 +0000 Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Shen, Bo Hlanze, Philani Cai, Jie https://escholarship.org/uc/item/7h09w0kh Housing sufficiency is an emerging concept in the provision of environmentally sustainable housing. It aims for demand-side strategies that reduce excessive, aggregate consumption levels to promote efficient resource utilization and sustainability in the construction sector while providing everyone with a decent standard of housing. However, it is challenging to implement as it interferes with housing-related social and cultural norms. This paper poses and answers ten questions that highlight the challenges, opportunities, and examples of sufficiency strategies in the context of housing provision and the environmental crisis. Question 1 discusses the need for sufficiency as a tool to complement supply-side strategies including efficiency and renewable energy strategies in providing housing. Question 2 examines the concept of housing sufficiency from different perspectives, such as ecological economics and social ecology. Question 3 summarizes the methods used to measure housing... https://escholarship.org/uc/item/7h09w0kh Thu, 27 Aug 2026 00:00:00 +0000 Arceo, Aldrick Touchie, Marianne O'Brien, William Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Malik, Jeetika https://orcid.org/0000-0003-0398-5303 Mayer, Matan Peters, Terri Saxe, Shoshanna Tamas, Ruth Villeneuve, Hannah Schmaltz, Benoît https://escholarship.org/uc/item/7fq9d8ng Accurate and efficient evaluations of refrigerant thermophysical properties and their partial derivatives are essential for transient simulations of thermofluid systems, where several computations need to be executed at each integration time step. Since the utilization of an Equation of State for retrieving properties based on a pair of independent inputs typically involves numerical iterations in solution procedures, when the input variables differ from the refrigerant state variables employed in dynamic models, a variety of approaches including lookup table interpolation and curve fitting have been developed to explicitly approximate these properties based on the state variables, and consequently eliminate internal iterations. This paper presents an alternative method that exploits derivative-informed neural networks to model refrigerant properties explicitly from inputs of pressure and enthalpy, while ensuring consistent partial derivatives generated by differentiating the... https://escholarship.org/uc/item/7fq9d8ng Thu, 27 Aug 2026 00:00:00 +0000 Ma, Jiacheng Thorade, Matthis Kim, Donghun https://orcid.org/0000-0002-1868-6341 https://escholarship.org/uc/item/71z5w93f Ruthenium (Ru) polypyridyl complexes have been extensively used as optical probes, photoactivated anticancer agents, and photocages for biologically active ligands. In this study, Ru²⁺ polypyridyl complexes were investigated as photoreleasing agents for the H₂S donor GYY4137. Four complexes of the general formula <i>cis</i>-[Ru(NN)₂(GYY4137)]⁺, where NN = 2-2'-bipyridine (bpy), 2,2'-biquinoline (biq), 4,4'-methoxy-2,2'-bipyridine (dmobpy), and 4,4'-di-<i>tert</i>-butyl-2,2'-bipyridine (dtbpy), were synthesized and characterized by NMR spectroscopy and X-ray crystallography. The photochemical reactivity of these complexes was investigated, revealing that ligand photodissociation occurs in a two-step reaction. For these reactions, long-lived intermediates where the bidentate ligands attain a monodentate coordination mode could be detected. Furthermore, the ancillary diimine ligands dictated the identity of the final photoproducts observed,... https://escholarship.org/uc/item/71z5w93f Thu, 27 Aug 2026 00:00:00 +0000 Lotlikar, PiyushaS Chang, Valerie Mikhailovsky, Alexander A Woods, Joshua J https://orcid.org/0000-0002-6213-4093 Bigham, Nicholas P Wilson, Justin J https://orcid.org/0000-0002-4086-7982 https://escholarship.org/uc/item/6sk8s22t Community-scale building retrofits are not merely scaled-up versions of single-building retrofits. They involve complex challenges, such as reconciling individual interests with collective goals and managing the dynamic interplay between buildings through mechanisms like power grids and social connections. Internet of Things (IoT) connectivity holds the potential to leverage these interplays to balance individual and collective interests effectively in smart communities. One critical aspect of this interplay is information diffusion, which shapes how retrofit decisions spread among neighbors, influencing individual choices and ultimately impacting community-level retrofit outcomes. In other words, IoT-based smart devices automatically push tailored retrofit notifications to homeowners, which completely changes the format of information diffusion in the future. To investigate this influence by such information diffusion, the study used CityBES to simulate energy performance for... https://escholarship.org/uc/item/6sk8s22t Thu, 27 Aug 2026 00:00:00 +0000 Shu, Lei Zhao, Dong Zhang, Wanni Li, Han https://orcid.org/0000-0003-4638-9907 Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 https://escholarship.org/uc/item/5t48x8xk As more distributed energy resources become part of the demand-side infrastructure, quantifying their energy flexibility on a community scale is crucial. CityLearn v1 provided an environment for benchmarking control algorithms. However, there is no standardized environment utilizing realistic building-stock datasets for distributed energy resource control benchmarking without co-simulation or third-party frameworks. CityLearn v2 extends CityLearn v1 by providing a stand-alone simulation environment that leverages the End-Use Load Profiles for the U.S. Building Stock dataset to create grid-interactive communities for resilient, multi-agent, and objective control of distributed energy resources with dynamic occupant feedback. While the v1 environment used pre-simulated building thermal loads, the v2 environment uses data-driven thermal dynamics and eliminates the need for co-simulation with building energy performance software. This work details the v2 environment and provides application... https://escholarship.org/uc/item/5t48x8xk Thu, 27 Aug 2026 00:00:00 +0000 Nweye, Kingsley Kaspar, Kathryn Buscemi, Giacomo Fonseca, Tiago Pinto, Giuseppe Ghose, Dipanjan Duddukuru, Satvik Pratapa, Pavani Li, Han https://orcid.org/0000-0003-4638-9907 Mohammadi, Javad Ferreira, Luis Lino Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Ouf, Mohamed Capozzoli, Alfonso Nagy, Zoltan https://escholarship.org/uc/item/5m42r7qw As we transition towards a decarbonized economy, the integration of variable renewable energy resources and new demands (e.g., electric vehicles, heat pumps) into the electricity grid places unprecedented pressure on grid operators to effectively anticipate and manage peak load. In this context, machine learning algorithms are proving to be indispensable for accurate short-term load forecasting, a crucial task to address these challenges. This study benchmarks 6 machine learning algorithms, including three neural networks and three tree-based algorithms, across various levels of spatial aggregation and time horizons (1, 4, 8, 24, and 48 h). The central contribution of this work is the comparison and analysis of load forecasting models not only based on statistical metrics, but also based on a novel error metric, which evaluates the cost implications of forecast errors for power system stakeholders. Results show that tree-based models outperform neural networks, based on statistical... https://escholarship.org/uc/item/5m42r7qw Thu, 27 Aug 2026 00:00:00 +0000 Houben, Nikolaus Heleno, Miguel https://orcid.org/0000-0001-8021-7661 Li, Han https://orcid.org/0000-0003-4638-9907 Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Auer, Hans Ajanovic, Amela Haas, Reinhard https://escholarship.org/uc/item/5fv266vz Membrane-electrode assemblies utilize ionomer-coated electrocatalysts to achieve facile ion transport. Consequently, isolation of intrinsic catalyst kinetics from measured polarization curves is challenging, as the properties of the catalyst and ionomer both affect the measurements. Here, we employ a Pt microelectrode coated by a thin perfluorosulfonic acid (PFSA) layer to measure polarization curves for the hydrogen oxidation reaction/hydrogen evolution reaction (HER/HOR). Intrinsic electrode kinetics are isolated by theoretical analysis of the local catalyst microenvironment, accounting for mass transport and thermodynamics. The observed enhancements in HER and HOR rates with increasing relative humidity (RH) at the working electrode are attributable to two competing factors: the decrease in activity of H+ in the ionomer and the dominant decrease in the water reorganization energy in the Marcus–Hush–Chidsey representation of HER/HOR kinetics. The increase in intrinsic rate with... https://escholarship.org/uc/item/5fv266vz Thu, 27 Aug 2026 00:00:00 +0000 Anderson, GraceC Rajupet, Siddharth Kushner, Douglas I https://orcid.org/0000-0002-3020-7737 Weber, Adam Z https://orcid.org/0000-0002-7749-1624 Radke, Clayton J https://orcid.org/0000-0002-1587-4822 Bell, Alexis T https://orcid.org/0000-0002-5738-4645 https://escholarship.org/uc/item/5d71h7zg Residential building energy retrofits are essential for enhancing environmental sustainability and reducing energy costs. The selection of retrofit measures is influenced by factors such as building systems, occupant behavior, government policy, weather variability, and climate change, all of which can significantly impact energy performance. Compared to retrofitting individual homes, evaluating and selecting optimal retrofit solutions for an entire community is challenging due to diverse residential compositions and variability present. Therefore, engineering robustness is crucial for ensuring consistent energy performance and resilience across different conditions. In this context, robustness refers to the ability of a retrofit measure to maintain its functionality and remain an optimal choice despite external disturbances or changes in inputs and conditions. This study presents a framework for evaluating the robustness of multiple retrofit measures across various building systems,... https://escholarship.org/uc/item/5d71h7zg Thu, 27 Aug 2026 00:00:00 +0000 Shu, Lei Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Sun, Kaiyu Zhao, Dong https://escholarship.org/uc/item/5928q8zf This study proposes a practical and simplified demand response (DR) control strategy from the perspective of grid-interactive efficient buildings (GEBs), aiming to secure demand flexibility while ensuring occupant thermal comfort. Focusing on summer on-peak periods, a linear demand response (LDR) strategy that integrates cooling setpoint adjustment and lighting dimming was designed, and its performance was quantitatively evaluated. A case study was conducted using EnergyPlus-based simulations for a U.S. DOE small office prototype building under summer on-peak weather conditions. Compared with a conventional rapid demand response (RDR) strategy, the proposed LDR approach gradually reduced electrical loads while maintaining occupant thermal comfort indices, including predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), within acceptable comfort ranges. Quantitative analysis of demand flexibility using the grid-interactive impact index (GII) and the flexibility... https://escholarship.org/uc/item/5928q8zf Thu, 27 Aug 2026 00:00:00 +0000 Jung, Dong Eun Seo, Byeongmo Choi, Haneul Han, Gwangwoo Jin, San Kim, Donghun https://orcid.org/0000-0002-1868-6341 Son, Sung-yong Kim, Jonghun https://escholarship.org/uc/item/5640136c Development and calibration of first-principles dynamic models of vapor compression cycles (VCCs) is of critical importance for applications that include control design and fault detection and diagnostics. Nevertheless, the inherent complexity of models that are represented by large systems of differential–algebraic equations leads to significant challenges for model calibration processes that utilize classical gradient-based methods. Bayesian optimization (BO) is a sample-efficient and gradient-free approach using a probabilistic surrogate model and optimal search over a feasible parameter space. Despite the benefits of BO in reducing computational costs, challenges remain in dealing with a high-dimensional calibration task resulting from a large set of parameters that have significant impacts on system behavior and need to be calibrated simultaneously. This paper presents a reduced-dimension BO framework for calibrating transient VCCs models where the calibration space is projected... https://escholarship.org/uc/item/5640136c Thu, 27 Aug 2026 00:00:00 +0000 Ma, Jiacheng Kim, Donghun https://orcid.org/0000-0002-1868-6341 Braun, James E https://escholarship.org/uc/item/54s0v55w The refrigerant charge level in heat pump systems significantly impacts their energy efficiency. Virtual refrigerant charge (VRC) sensing technology has been comprehensively investigated and well-established due to its lower cost compared to physical sensors. However, the previous VRC research often relied on expert judgment and physical reasoning for their variable selection, which can potentially select redundant (or highly correlated) or insignificant features, and it is also primarily focused on single-speed systems. To address these challenges, this study proposes a VRC algorithm for variable-speed heat pumps that selects features through a rigorous feature selection method in combination with physical insights. We also propose a piecewise linear model structure segmented by subcooling temperature to accurately predict charge levels, particularly when subcooling temperatures are substantially low. The proposed algorithm was evaluated using experimental data of a residential... https://escholarship.org/uc/item/54s0v55w Thu, 27 Aug 2026 00:00:00 +0000 Liang, Chenjiyu Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Hlanze, Philani Cai, Jie https://escholarship.org/uc/item/2bd2z9sw The charge level of refrigerant in heat pump systems significantly affects their operational performance. Virtual refrigerant charge (VRC) sensing technology has been well-established for traditional refrigerants (HFCs and HCFCs) for its low cost compared to physical sensors. However, other than traditional refrigerants, HFOs are increasingly used in next-generation heat pumps; whether these conventional VRC sensing methods remain applicable for heat pump systems utilizing next-generation refrigerants requires further investigation. To address these issues, this study develops a low-cost VRC sensing method for next-generation refrigerant heat pumps used in residential buildings. The developed algorithm is evaluated by using simulation models to evaluate the accuracy, considering an R454B heat pump with a nominal heating capacity of 51K Btu/hr (14.95 kW) as an example, and compared with those of the two reference VRC sensing algorithms. Though the developed VRC sensing algorithm... https://escholarship.org/uc/item/2bd2z9sw Thu, 27 Aug 2026 00:00:00 +0000 Liang, Chenjiyu https://orcid.org/0009-0003-6454-5915 Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Shen, Bo https://escholarship.org/uc/item/11t9j3x1 Industrial separation processes account for 10-15% of global energy consumption. Membrane-based processes are less energy-intensive than traditional gas separation technologies; however, enhanced material separation performance and stability for numerous gas mixtures are needed for widespread industrial adoption. This work presents a generalizable strategy for preparing mixed-matrix gas separation membranes exceeding the performance upper bounds of existing polymer membranes for a wide variety of industrial gases. By incorporating robust porous aromatic framework (PAF) particles into various dense commercial polymer matrices, gas diffusivity and solubility can be enhanced. For diverse gas mixtures (e.g., CO₂/N₂, O₂/N₂, He/CH₄, H₂/N₂, and C₂H₄/C₂H₆), the resulting composite membranes exhibit enhanced gas permeabilities-by as much as 520%-and largely unchanged... https://escholarship.org/uc/item/11t9j3x1 Thu, 27 Aug 2026 00:00:00 +0000 Uliana, Adam A Velasquez, Ever O Graf, Katerina I Kwon, Ohchan Engler, Kaitlyn E Miller, Daniel J Long, Jeffrey R https://orcid.org/0000-0002-5324-1321 https://escholarship.org/uc/item/0sq1f441 Project 2 develops software infrastructure, test cases, and extensions for the Building Optimization Testing Framework (BOPTEST) to address the expanding needs of building and urban energy system controls through open international collaboration. This paper provides an overview of the new test cases available as of BOPTEST version 0.7.1. Each test case is developed using open-source Modelica libraries and Spawn of EnergyPlus, enabling the creation of high-fidelity building models that incorporate envelope dynamics, Heating Ventilation and Air Conditioning (HVAC) systems, and explicit control representations. Currently, eight test cases are available, with five additional cases under development. These test cases cover a wide range of climates, building types, and HVAC systems. This paper compiles and summarizes test case descriptions, cites original manuscripts that developed them for a more detailed description, and reports baseline control performance metrics. Furthermore, two... https://escholarship.org/uc/item/0sq1f441 Thu, 27 Aug 2026 00:00:00 +0000 Zanetti, Ettore https://orcid.org/0000-0002-9056-3813 Blum, David https://orcid.org/0000-0003-3231-7937 Arroyo, Javier Walnum, Harald Taxt Cupeiro, Iago Van Hove, Matthias Lu, Xing Chen, Yan Bae, Yeonjin Li, Guowen Zhang, Kun https://escholarship.org/uc/item/08f1371p Efficient control of Heating, Ventilation, and Air Conditioning (HVAC) systems is crucial for optimizing energy use and maintaining indoor comfort in buildings. Traditional control methods, such as PID control, cannot handle energy use trade-offs among multiple components in the building energy system at a supervisory level. Reinforcement learning (RL) presents a promising solution, offering adaptive and data-driven control strategies that optimize performance over time. However, RL also faces several challenges, including the conflicts encountered in co-optimizing energy savings, occupant comfort, and indoor air quality, and the requirement for extensive interactions with the environment in training. We proposed a flexible simulation platform that integrates a hybrid model for RL training and designed an RL agent to control the entire central HVAC system, focusing on co-optimizing energy consumption, thermal comfort, and indoor air quality ($\text{CO}_{2}$ and PM2.5 concentrations).... https://escholarship.org/uc/item/08f1371p Thu, 27 Aug 2026 00:00:00 +0000 Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Ham, Sang woo https://orcid.org/0000-0003-1776-2610 Kim, Donghun https://orcid.org/0000-0002-1868-6341 https://escholarship.org/uc/item/9s30g2mq Providing fresh air to rooms can ensure indoor air quality. The direct expansion fresh air handling units are widely used, and most of them are single-stage treatment units, which are less energy-efficient under variable operating conditions. To overcome the shortcomings of existing systems, a direct expansion system using multiple stages and adjustable heat exchange areas for fresh air handling is proposed in this study. The fresh air is handled by coils stage by stage to achieve high efficiency, and the dampers of the idle coils are opened when some of the coils are working, which results in the performance improvement under partial load conditions. The simulation model is established, and operating conditions at load ratio of 95.70%, 45.38%, 31.76% and 0 are selected as typical operating conditions. The proposed system performances under different conditions are compared with traditional system. The results show that: (1) For four conditions, as the load rate decreases, the... https://escholarship.org/uc/item/9s30g2mq Wed, 26 Aug 2026 00:00:00 +0000 Zha, Fuhai Liang, Chenjiyu https://orcid.org/0009-0003-6454-5915 Fang, Lin Tanaka, Toshio Matsui, Nobuki Li, Xianting https://escholarship.org/uc/item/9km6t35v While standardized ontologies like the Brick schema address data heterogeneity in Building Automation Systems (BAS), accessing this semantic data remains a challenge as domain experts often lack the expertise to formulate complex SPARQL queries. To bridge this gap, we present BrickQA, a Large Language Model (LLM)-based framework that translates natural language into executable SPARQL queries through structured query decomposition, dynamic schema exploration, and inline validation. BrickQA utilizes an iterative reasoning agent to actively navigate graph topology through dynamic exploration actions without requiring exhaustive context injection or model fine-tuning. This approach effectively mitigates hallucinations, particularly in large-scale building knowledge graphs. Empirical evaluation on BuildingQA, a standardized benchmark, demonstrates that BrickQA significantly outperforms ReAct baselines, delivering a 0.291–0.355 absolute F1 improvement while achieving 3 × –12.7 × higher... https://escholarship.org/uc/item/9km6t35v Wed, 26 Aug 2026 00:00:00 +0000 Ko, Yun-Dam Jung, Hyeyun Eunice Pritoni, Marco https://orcid.org/0000-0003-4200-6905 Jain, Rishee https://escholarship.org/uc/item/99z5314d Electrification of residential buildings is a key strategy for increasing the use of renewable energy sources. Central to this transition is understanding the capacity of existing electrical infrastructure—specifically electrical panels—to safely and effectively manage increased electricity demands from electrification technologies. However, comprehensive nationwide data on electrical panel capacities in U.S. single-family homes is currently lacking. To address this gap, we conducted a nationwide survey of single-family homes, collecting detailed data on electrical panel capacities, breaker slot availability, major electric and gas appliances, electrical panel models, and home characteristics such as construction year and floor area. Photographic documentation was used to verify electrical panel data and appliance information. Results show that approximately 60% of surveyed homes have electrical panels rated at ≥200 amperes (A), indicating that a significant portion of the existing... https://escholarship.org/uc/item/99z5314d Wed, 26 Aug 2026 00:00:00 +0000 Gul, Sadia Meier, Alan https://orcid.org/0000-0002-1260-2151 https://escholarship.org/uc/item/8nq156tb The multi-stage air treatment system has been proposed recently, and lower grade chilled/hot water could be used and energy efficiency could be improved. However, it has not been studied which division method of air treatment processes has higher energy efficiency. In this study, the model to calculate the energy consumption of multi-stage air treatment process is introduced, and the effects of two division methods, i.e. multi-stage air treatment process divided by the same temperature difference (ST method) or same enthalpy difference (SE method) between inlet and outlet at each stage, under 9 different air inlet parameters in the 2-stage and 3-stage air treatment processes are analysed and compared. The results show that (1) the system energy consumption of the SE method is generally lower than that of the ST method; (2) there is generally a larger energy consumption reduction rate of SE method when the air relative humidity is 70% compared to relative humidity of 50% and 90%;... https://escholarship.org/uc/item/8nq156tb Wed, 26 Aug 2026 00:00:00 +0000 Wang, Wentao Liang, Chenjiyu https://orcid.org/0009-0003-6454-5915 Zha, Fuhai Li, Xianting https://escholarship.org/uc/item/8gm2d39b U.S. Commercial buildings account for about 20% of total U.S. energy consumption. Because the thermal performance of windows significantly affects building energy efficiency and HVAC system performance, best practice guidance often includes window and envelope improvements in conjunction with HVAC upgrades to optimize energy use and improve occupant comfort. It is an open question, however, regarding how often these best practices are implemented in the field. This paper aims to address that gap by conducting a literature review and a series of interviews with commercial building auditing and management professionals to explore the factors that drive window retrofits in commercial buildings. The paper explores a range of case studies from deep energy retrofits across the globe, comparing projects with and without window retrofits. The primary goals of this review are to: (1) provide data from real-world case studies illustrating the role of windows in deep energy renovations and... https://escholarship.org/uc/item/8gm2d39b Wed, 26 Aug 2026 00:00:00 +0000 Cort, Katherine Palani, Hevar Kono, Jamie Stanislaus, Travis Bhandari, Mahabir Hart, Robert https://escholarship.org/uc/item/8553f80m The growing energy demand of the industrial sector and the need for sustainable solutions highlight the importance of efficient decision making in solar photovoltaic (PV) implementation. Selecting optimal PV configuration is complex due to the interdependent technical, economic, environmental, and social factors involved. This study introduces an integrated decision-making method combining a morphological matrix and fuzzy TOPSIS to systematically select and rank optimal PV system configurations for manufacturing firms. While the morphological matrix exhaustively examines possible design solutions based on sensing, smart, sustainable, and social (S4) attributes, the fuzzy TOPSIS method ranks the alternatives by handling uncertainty in decision making. A case study conducted in a Mexican manufacturing company validates the methodology’s effectiveness. The optimal PV configuration identified comprehensively addresses operational and sustainability criteria, covering all lifecycle... https://escholarship.org/uc/item/8553f80m Wed, 26 Aug 2026 00:00:00 +0000 Briceño, Citlaly Pérez Ponce, Pedro Fayek, Aminah Robinson Anthony, Brian Bradley, Russel Peffer, Therese https://orcid.org/0000-0001-5569-7448 Meier, Alan https://orcid.org/0000-0002-1260-2151 Mei, Qipei https://escholarship.org/uc/item/826584wd With the recent demand for decarbonization and energy efficiency, advanced HVAC control using Deep Reinforcement Learning (DRL) becomes a promising solution. Due to its flexible structures, DRL has been successful in energy reduction for many HVAC systems. However, only a few researches applied DRL agents to manage the entire central HVAC system and control multiple components in both the water loop and the air loop, owing to its complex system structures. Moreover, those researches have not extended their applications by incorporating the indoor air quality, especially both CO2 and PM2.5concentrations, on top of energy saving and thermal comfort, as achieving those objectives simultaneously can cause multiple control conflicts. What's more, DRL agents are usually trained on the simulation environment before deployment, so another challenge is to develop an accurate but relatively simple simulator. Therefore, we propose a DRL algorithm for a central HVAC system to co-optimize... https://escholarship.org/uc/item/826584wd Wed, 26 Aug 2026 00:00:00 +0000 Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Ham, Sang woo https://orcid.org/0000-0003-1776-2610 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Moon, Hyeun Jun https://escholarship.org/uc/item/7vb673m7 The authors regret an error in the acknowledgments section regarding the U.S. Department of Energy Solar Energy Technologies Office award number. The previously listed grant number, 2597–1625, was incorrect. The corrected acknowledgment should read: “This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technologies of the United States Department of Energy (DOE), under Contract No. DE-AC02–05CH11231. This material is based upon work supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Solar Energy Technologies Office Award Number DE-EE00040384. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Department of Energy.” The authors would like to apologise for any inconvenience caused. https://escholarship.org/uc/item/7vb673m7 Wed, 26 Aug 2026 00:00:00 +0000 Malik, Jeetika https://orcid.org/0000-0003-0398-5303 Wei, Max Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 https://escholarship.org/uc/item/7676p1xs K-12 school buildings account for the highest energy consumption within the public sector. Implementing advanced HVAC controls in grid-interactive K-12 schools could bring substantial economic advantages and grid flexibility. Our previous study demonstrated that a low-cost model predictive control (MPC) solution, which coordinates multiple packaged units, can enable demand flexibility without major hardware upgrades. However, a significant gap remains between academic pilots and market-ready scalable solutions. This paper extends the previous single-site pilot to a multi-site demonstration involving three school campuses (95 total units) through a commercial technology transfer process. Addressing the challenge of verifying performance with sparse field data, we present a new statistical approach using Bayesian methods to estimate the MPC’s effect on peak demand. Unlike traditional methods, this approach robustly quantifies uncertainty in non-normal, limited datasets. The results... https://escholarship.org/uc/item/7676p1xs Wed, 26 Aug 2026 00:00:00 +0000 Ham, Sang Woo https://orcid.org/0000-0003-1776-2610 Hariri, Mohamad El Kim, Donghun https://orcid.org/0000-0002-1868-6341 Barham, Tanya https://escholarship.org/uc/item/75n9f2w1 Frequent heatwaves and hot summers increasingly challenge occupant comfort, health, and energy grid stability. Addressing these challenges requires a detailed understanding of household cooling behaviors, such as thermostat adjustments and adaptive responses to extreme conditions. Traditional analyses often rely on aggregated numerical metrics that overlook subtle but important household-specific variations. In this study, we introduce a generalizable methodology that integrates large language models (LLMs) with vision capabilities to enable scalable and detailed analysis of residential thermostat data. Using Ecobee's Donate Your Data (DYD) dataset—which provides five-minute records of indoor temperatures, thermostat setpoints, and HVAC runtimes—we focus on two U.S. cities with contrasting summer climates : Austin (TX) and Phoenix (AZ). Because raw time-series data are not well suited for direct LLM analysis, we transform them into visual representations, such as daily indoor... https://escholarship.org/uc/item/75n9f2w1 Wed, 26 Aug 2026 00:00:00 +0000 Nihar, Kopal Li, Han https://orcid.org/0000-0003-4638-9907 Malik, Jeetika https://orcid.org/0000-0003-0398-5303 Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 https://escholarship.org/uc/item/5h30p5xb We present a fast sparse matrix permutation algorithm tailored to linear systems arising from triangle meshes. Our approach produces nested-dissection-style permutations while significantly reducing permutation runtime overhead. Rather than enforcing strict balance and separator optimality, the algorithm deliberately relaxes these design decisions to favor fast partitioning and efficient elimination-tree construction. Our method decomposes permutation into patch-level local orderings and a compact quotient-graph ordering of separators, preserving the essential structure required by sparse Cholesky factorization while avoiding its most expensive components. We integrate our algorithm into vendor-maintained sparse Cholesky solvers on both CPUs and GPUs. Across a range of graphics applications, including single factorizations and repeated factorizations, our method reduces permutation time and improves the sparse Cholesky solve performance by up to 6.27 ×. Our code is available at... https://escholarship.org/uc/item/5h30p5xb Wed, 26 Aug 2026 00:00:00 +0000 Zarebavani, Behrooz Mahmoud, Ahmed H Dodik, Ana Yuan, Changcheng Porumbescu, Serban D Owens, John D https://orcid.org/0000-0001-6582-8237 Dehnavi, Maryam Mehri Solomon, Justin https://escholarship.org/uc/item/5874h222 Supplying fresh air is important for indoor air quality, but the energy consumption to treat fresh air is significant. The main problems in existing fresh air system include: supplying single-temperature water to treat fresh air and not applying natural energy sufficiently restrict the efficiency improvement of cooling and heat sources; unused air handling devices under most operating conditions throughout the year increase the fan energy consumption. Thus, this study proposes an efficient fresh air system that uses lake water to pre-treat fresh air and two-stage heat pumps for further treatment, and the unused air handling devices in the system are bypassed. A fresh air system in northern China is selected as a case to show the annual energy performance of the proposed system, and a comparative analysis is conducted between the proposed system and a traditional system. The results show that the annual energy-savings of the proposed system compared to the traditional system come... https://escholarship.org/uc/item/5874h222 Wed, 26 Aug 2026 00:00:00 +0000 Liang, Chenjiyu https://orcid.org/0009-0003-6454-5915 Li, Xianting https://escholarship.org/uc/item/3ng7f19j To achieve energy efficiency in the operation of heating devices and ensure thermal comfort in indoor environments, the integrated convective/radiant terminals have become an important development direction for heating systems. This study selected a 14 m 2 bedroom hot summer and cold winter region in China as a case study. Computational Fluid Dynamics (CFD) methodology was used to investigate the design of integrated convective/radiant terminals to ensure thermal comfort for both the entire room and partial space. The results indicate that focusing on partial space during the steady-state stage can achieve energy savings of 31.1% compared to guaranteeing the entire room. Additionally, during the start-up stage, there is a significant reduction of convective unit capacity by 17.6% when the start-up time is 15 minutes. These findings provide data support for the design and engineering applications of products of integrated convective/radiant terminals. Besides, the excess convection... https://escholarship.org/uc/item/3ng7f19j Wed, 26 Aug 2026 00:00:00 +0000 Chi, Junjie Yang, Zixu Liang, Chenjiyu https://orcid.org/0009-0003-6454-5915 Wang, Baolong Li, Xianting Shi, Wenxing https://escholarship.org/uc/item/3d86v8rd Building Performance Simulation (BPS) has been adopted as an essential tool for designing, operating, and retrofitting buildings to optimize energy efficiency throughout the building life cycle. The Green Building XML (gbXML) schema facilitates seamless data exchange between Building Information Modeling (BIM) and Building Energy Modeling (BEM) software tools. However, limited occupant behavior (OB) representation in BIM often leads to inconsistent and inaccurate energy simulation in BEM software. This paper presents 154 systematic enhancements to the existing occupant behavior XML (obXML) schema v1.3.4, initially developed for standardizing OB representation for BEM, to address existing limitations and improve interoperability with BIM models. The enhancements encompass improved integration with BIM models through extended building representations and system operations, expanded support for advanced OB models with additional environmental parameters and mathematical capabilities,... https://escholarship.org/uc/item/3d86v8rd Wed, 26 Aug 2026 00:00:00 +0000 Chung, Jihoon Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 Malik, Jeetika https://orcid.org/0000-0003-0398-5303 Shelden, Dennis https://escholarship.org/uc/item/3b60j9mt The reliable determination of transition states (TSs) benefits from second-order information for robust convergence and validation, but the computational expense of Hessians prohibits their routine use in TS optimization. Here, we present a machine-learning-driven TS optimizer that directly predicts the leftmost Hessian eigenvector (LMHE), which is the critical mode that locally approximates the reaction coordinate encompassing the TS. We demonstrate that our LMHE optimizer recovers TS solutions at the same rate as full-Hessian optimizers and robustly from degraded initial guess geometries, thereby eliminating the excessively long wall times characteristic of full-Hessian approaches and reducing total gradient evaluations compared to standard quasi-Newton methods. We further improve accuracy and robustness using uncertainty quantification for identifying occasional LMHE prediction failures, where we then fall back to a full-Hessian update from the machine-learned potential at... https://escholarship.org/uc/item/3b60j9mt Wed, 26 Aug 2026 00:00:00 +0000 Wu, Guanchen https://orcid.org/0009-0008-5789-6393 Yuan, Eric C-Y Hegazy, Kareem Blau, Samuel M Head-Gordon, Teresa https://orcid.org/0000-0003-0025-8987 https://escholarship.org/uc/item/3056t653 The unprecedented growth in artificial intelligence (AI) workloads, recently dominated by large language models (LLMs) and vision-language models (VLMs), has intensified power and cooling demands in data centers. This study benchmarks LLMs and VLMs on two HGX nodes, each with 8× NVIDIA H100 graphics processing units (GPUs), using liquid and air cooling. Leveraging GPU Burn, Weights &amp; Biases, and IPMItool, we collect detailed thermal, power, and computation data. Results show that the liquid-cooled systems maintain GPU temperatures between 41-50$^\circ$C, while the air-cooled counterparts fluctuate between 54-72$^\circ$C under load. This thermal stability of liquid-cooled systems yields 17% higher performance (54 TFLOPs/ GPU vs. 46 TFLOPs/GPU), performance-per-watt, reduced energy overhead, and greater system efficiency than the air-cooled counterparts. These findings underscore the energy and sustainability benefits of liquid cooling, offering a compelling path forward for... https://escholarship.org/uc/item/3056t653 Wed, 26 Aug 2026 00:00:00 +0000 Latif, Imran Shafique, Muhammad Ali Ullah, Hayat Newkirk, Alex C https://orcid.org/0000-0002-6213-6865 Yu, Xi Munir, Arslan https://escholarship.org/uc/item/2tm676r4 Building energy simulation is a critical tool for developing and testing advanced control strategies, such as Reinforcement Learning (RL), to provide demand flexibility and affordable energy costs. The recently introduced Smart Buildings Control Suite (sbsim) provides a lightweight, scalable, and data-calibrated simulation environment based on a 2D finite-difference model. However, the initial model primarily focused on conductive and convective heat transfer, neglecting the significant impact of long-wave radiative heat exchange between interior surfaces. This paper presents a significant extension to the sbsim framework by incorporating a physically-grounded model for interior radiative heat transfer. Our primary contribution is the development and integration of a fully tensorized radiative heat transfer module, which preserves the computational efficiency and scalability of the original simulator. This was achieved by developing a pipeline for view factor calculation, including... https://escholarship.org/uc/item/2tm676r4 Wed, 26 Aug 2026 00:00:00 +0000 Ham, Sang woo https://orcid.org/0000-0003-1776-2610 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Rossetti, Michael Sipple, John https://escholarship.org/uc/item/2r84r4qs Urban Building Energy Modeling (UBEM) is an important reference for urban energy-related policymaking. Because of the significant impact of urban microclimates on the energy simulation, UBEM requires simulations of many microclimate-prototype pairs. Surrogate modeling is commonly used to reduce the cost of simulation computations. In UBEM surrogate modeling, it is important to determine the percentage of microclimates related to a prototype used for generating surrogate model training data. This study analyzes the prototype-wise variations and sensitivities of surrogate model estimation accuracy to the microclimate sampling ratios. The results of the study can help determine the number of simulations used for generating surrogate modeling data, avoid redundant simulations, and reduce the computational cost for UBEM surrogate modeling and its time. https://escholarship.org/uc/item/2r84r4qs Wed, 26 Aug 2026 00:00:00 +0000 Pan, Xiyu Mohammadi, Neda Taylor, John E Xu, Yujie https://orcid.org/0000-0002-1805-1872 Hong, Tianzhen https://orcid.org/0000-0003-1886-9137 https://escholarship.org/uc/item/1r95j7rd Shallow geothermal has gained increasing attention in recent years; however, a reliable framework for its accurate incorporation into large-scale energy system optimization remains lacking. This study proposes a Mixed-Integer Linear Programming (MILP) framework combined with the g-function approach to integrate Borehole Thermal Energy Storage (BTES) technology into energy system optimization. Validation against a Modelica-based reservoir network simulation demonstrates that the proposed framework effectively captures the ground thermal response under varying energy loads and accurately estimates the borefield energy supply. To enhance scalability, a Rolling Horizon with Multi-Timescale (RH-MTS) method is further introduced, reducing computational time by 73 % for the 1-year optimization model with only minor loss of optimality. The framework is demonstrated through the case study of the UC Berkeley campus. Results indicate that BTES is a cost-effective and low-carbon solution:... https://escholarship.org/uc/item/1r95j7rd Wed, 26 Aug 2026 00:00:00 +0000 Yang, Jiahui Soga, Kenichi Sulzer, Matthias https://orcid.org/0000-0003-2094-2460 Chen, Kecheng https://escholarship.org/uc/item/1bs9m05r Natural refrigerants are increasingly adopted in next-generation heat pump systems, among which CO₂ heat pumps have attracted significant attention. However, due to their high operating pressures, the leakage risk is higher, resulting in undercharge conditions and degraded heat pump performance. Thus, developing an accurate refrigerant charge level detection technique is necessary to guarantee safe and efficient operation. Although virtual refrigerant charge (VRC) level calculation algorithms for CO₂ heat pumps exist, they typically rely on empirically selected features without a systematic selection framework, leading to multicollinearity and potential overfitting, which limit their prediction accuracy and generalizability. To address these issues, this study proposes a VRC algorithm framework with a systematic feature selection method that identifies physically meaningful and statistically significant features, and is applied using a residential CO₂ heat pump as a case study.... https://escholarship.org/uc/item/1bs9m05r Wed, 26 Aug 2026 00:00:00 +0000 Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Liang, Chenjiyu https://orcid.org/0009-0003-6454-5915 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Shen, Bo Hu, Yifeng https://escholarship.org/uc/item/0vs9c70h The removal of selenite (SeO₃^2-) from water is challenging due to the risk of secondary pollutants. To address this, we developed RuO₂-based nanocatalysts on the titanium plate (RuO₂/TP) for direct electrochemical reduction of Se(IV) to elemental selenium [Se(0)]. Optimizing Sn doping in RuO₂ nanoparticles to induce charge redistribution enabled the Ru_0.9Sn_0.1O_<i>x</i>/TP catalyst to achieve ∼90% Se(IV) removal across concentrations of 0.1, 1, and 10 mM at -2 mA cm^-2 over 8 h, outperforming undoped RuO₂/TP. Furthermore, Ru_0.9Sn_0.1O_<i>x</i>/TP also maintained ∼90% removal efficiency in 1 mM of Se(IV) solutions containing competitive anions (0.5 M Cl^-, 0.1 M SO₄^2-, 0.01 M NO₃^-, and their mixtures), demonstrating suitability for complex wastewater treatment. Importantly, the catalysts... https://escholarship.org/uc/item/0vs9c70h Wed, 26 Aug 2026 00:00:00 +0000 Hao, Shaoyun Feng, Yuge Wang, Duo Cho, Jinwon https://orcid.org/0000-0003-0200-2950 Qiu, Chang Wi, Tae-Ung Xu, Ziang Yu, Zhou Sellers, Chase Zou, Shiqiang Jain, Anubhav https://orcid.org/0000-0001-5893-9967 Wang, Haotian https://escholarship.org/uc/item/0gb1x475 Advanced supervisory-level control with reinforcement learning (RL) is regarded as a promising solution for HVAC systems to minimize energy consumption while maintaining thermal comfort and indoor air quality. However, most RL applications were conducted in the simulation environment rather than real-world HVAC systems. This paper developed a value-based RL controller termed Deep Q-Network (DQN) for a typical central HVAC system and evaluated its performance in a building test facility. By comparing DQN with a rule-based controller, the study not only demonstrated the cases where DQN could properly maintain indoor comfort but also discussed possible reasons why DQN failed in some other situations. Recognizing the limitations of value-based RL algorithms from the experimental tests, a simulation study was conducted to compare DQN with an alternative RL approach, an actor–critic algorithm termed Deep Deterministic Policy Gradient (DDPG). In scenarios with a relatively large action... https://escholarship.org/uc/item/0gb1x475 Wed, 26 Aug 2026 00:00:00 +0000 Guo, Fangzhou https://orcid.org/0000-0001-6234-3090 Ham, Sang woo https://orcid.org/0000-0003-1776-2610 Kim, Donghun https://orcid.org/0000-0002-1868-6341 Kim, Sun Ho Moon, Hyeun Jun https://escholarship.org/uc/item/9xj455kh A dynamic disulfide network introduced into donor/acceptor blends enables room-temperature self-healing and mechanical resilience in intrinsically stretchable organic solar cells, achieving performance recovery after high mechanical strain. The development of intrinsically stretchable organic solar cells (IS-OSCs) faces significant challenges in balancing mechanical durability and optoelectronic performance. Conventional π-conjugated polymer-based donor/acceptor blend films often exhibit limited stretchability and irreversible performance degradation under mechanical strain. To address these limitations, we propose a novel self-healable donor/acceptor blended film with a dual-network morphology, achieved by incorporating a dynamic disulfide bond-based crosslinked network into the bulk-heterojunction film. The resulting thin films demonstrate a power conversion efficiency (PCE) of 16.39% in rigid OSC devices and a fracture strain of 15.6%. Remarkably, the IS-OSCs retain 80% of... https://escholarship.org/uc/item/9xj455kh Tue, 25 Aug 2026 00:00:00 +0000 Yang, Wenyu Luo, Xuanang Liu, Jiankang Chen, Jingchuan Wu, Xuefei Fink, Zachary Shi, Chuqi Zhong, Wenkai Wang, Cheng https://orcid.org/0000-0001-7192-5471 Ying, Lei https://escholarship.org/uc/item/8v66207m For accurate characterization of grazing-incidence X-ray mirrors, we present a comprehensive framework to fit measured surface shapes (either slope or height) of X-ray mirrors used in synchrotron radiation and free-electron laser facilities. We summarize the closed-form expressions of some typical surface shapes of X-ray mirrors including elliptic cylinders, hyperbolic cylinders, ellipsoids, hyperboloids, and diaboloids. This framework is composed of four layers: definition of standard shapes with closed-form expressions, generation of theoretical surface with pose parameters (six degrees of freedom defining an object's position and orientation relative to a coordinate system), parameter optimization with the ability to select which parameters are fit and which are held constant, and the development of user-friendly fitting function wrappers for&nbsp;particular fitting tasks. A few practical fitting examples are demonstrated to verify the effectiveness of the proposed fitting... https://escholarship.org/uc/item/8v66207m Tue, 25 Aug 2026 00:00:00 +0000 Huang, Lei Xu, Ruochen Wang, Tianyi Yamada, Jumpei Dvorak, Joseph Austin, Corey Van Eeckhout, Albert Roman, Josep Nicolàs Goldberg, Kenneth https://orcid.org/0000-0001-9984-5780 Idir, Mourad https://escholarship.org/uc/item/8jg734t5 Photoenzymatic reduction of CO₂ to formate is a promising strategy for carbon valorization, yet its efficiency is still limited by inefficient energy and mass transport. Here, we design a series of isostructural hydrogen-bonded organic frameworks (HOFs) that establish confinement effects to promote photocatalytic NADH regeneration and the subsequent NADH-dependent enzymatic CO₂-to-formate reduction. We demonstrate that spatial confinement within the framework channels localizes exciton migration to nanoscale domains and promotes interfacial dissociation. Additionally, Rh-induced electronic-structure modulation enables ultrafast electron transfer, while the intrinsic hydrogen-bond network furnishes directional proton conduction to NAD⁺. These synergistic regulations afford a photocatalytic NADH regeneration efficiency of 99.8% with a record apparent quantum efficiency of 32.8%, and drive formate production at a rate of 3020 μmol g^-1 h^-1... https://escholarship.org/uc/item/8jg734t5 Tue, 25 Aug 2026 00:00:00 +0000 Xu, Jiaxing Zhang, Xiang Ma, Lijuan Wu, Tao Wang, Hui Deng, Yuanfang Xia, Jun Qiu, Zhongyang Sun, Kai He, Aiyong Zhang, Jian https://orcid.org/0000-0003-0274-0814 Zhang, Xu Chen, Banglin https://escholarship.org/uc/item/8g14h50r Abstract Polarization detection enhances signal contrast and is widely utilized in diverse advanced applications. An ongoing challenge is the development of high‐performance polarization‐sensitive photodetectors based on optically anisotropic organic semiconductors, particularly in the near‐infrared (NIR) region. While uniaxially aligned π‐conjugated polymers with high aspect ratios exhibit strong linear dichroism and have shown promise, their limited NIR performance and heavy reliance on polymer material now represent critical limitations. Here, a breakthrough is reported in achieving giant linear dichroism and exceptional polarization detection with low aspect‐ratios (AR) non‐fullerene small‐molecule (NFSM) acceptors, extending polarization sensitivity from the UV–vis to the NIR range. An impressive dichroic ratio of 27.1 at 605 nm and 12.0 at 780 nm is demonstrated. The maximum polarization photocurrent ratio is 11.2 at 780 nm under parallel versus perpendicular polarized light.... https://escholarship.org/uc/item/8g14h50r Tue, 25 Aug 2026 00:00:00 +0000 Xue, Yingying Zuo, Qiong Zhu, Qi Li, Yukun Deng, Zilin Zhang, Zibang Yang, Zhiyuan Wang, Cheng https://orcid.org/0000-0001-7192-5471 Zhang, Rui Liu, Xianjie Zhong, Jingang Zhong, Wenkai Ying, Lei Cai, Wanzhu https://escholarship.org/uc/item/7pp3n21m It is a critical national imperative to transform the buildings sector, yet innovation is impeded by deployment failures that leave promising technologies stranded. Conventional market reports and techno-economic analysis provide an insufficient understanding of markets and resource allocation for emerging building technologies. They omit crucial commercialization factors such as ecosystem maturity and adoption friction, where the coordinated participation of a network of suppliers, contractors, financiers, regulators, and integrators is required to scale solutions. This study addresses these gaps by introducing an evaluation framework grounded in front-line data from six years of the DOE's IMPEL incubator, comprising experience from 300 building-sector innovators and the adjacent, complex ecosystem. Our methodology synthesizes top-down market analysis with bottom-up, practitioner-level data across five megatrends: (M1) Affordable materials and industrialized construction; (M2)... https://escholarship.org/uc/item/7pp3n21m Tue, 25 Aug 2026 00:00:00 +0000 Singh, Reshma Jain, Yashima https://escholarship.org/uc/item/76h4s78v Connecting 0 K density functional theory (DFT) energies to finite-temperature, finite-pressure synthesis conditions is a well-established thermodynamic formalism, yet quantified guidance on when and how to accurately calibrate these results to experimental chemical potentials in practice remains sparse. In this work, we systematically benchmark a complete workflowthe virtual furnacethat constructs effective oxygen chemical potentials (μO2) for common synthesis atmospheres (air, Ar, H2, CO) as functions of temperature and partial pressure and propagates quantified errors from formation enthalpies through reaction energies to critical chemical potentials. Applying this workflow to 11 binary oxides, we find that “gas-only” thermal corrections are sufficient at low temperatures and for Group II oxides across all temperatures, while solid-phase vibrational contributions become critical at elevated temperatures for transition metal oxides. We quantify this threshold through the ratio... https://escholarship.org/uc/item/76h4s78v Tue, 25 Aug 2026 00:00:00 +0000 Walters, Lauren N https://orcid.org/0000-0002-9710-9146 Jain, Anubhav https://orcid.org/0000-0001-5893-9967 Ceder, Gerbrand https://orcid.org/0000-0001-9275-3605 https://escholarship.org/uc/item/757507rg Elemental carbon (EC), operationally quantified by thermal-optical analysis, is widely used as a proxy for black carbon (BC) relevant to short-term climate forcing and public health. Current EC emission inventories remain highly uncertain, with persistent discrepancies between bottom-up and top-down estimates. In this study, we develop a source-resolved, log-space Bayesian inversion framework applied to estimate California’s statewide EC emissions in 2019. By integrating surface EC measurements from the EPA’s Air Quality System network with high-resolution source contributions simulated by a chemical transport model, we identify a one-third underestimation in the existing statewide EC inventory, requiring an increase of the total from a prior of 8.58 [5.49–13.75] Gg year–1 to a posterior estimate of 12.78 [10.71–15.37] Gg year–1. This discrepancy is primarily driven by substantial underestimations in the power and industrial and off-road mobile sectors. Furthermore, population-weighted... https://escholarship.org/uc/item/757507rg Tue, 25 Aug 2026 00:00:00 +0000 Zhang, Jie https://orcid.org/0000-0001-6400-3639 Jin, Ling Xu, Xiaodan https://orcid.org/0000-0002-9650-9156 Neyestani, Soroush E Zhang, Xinyi Ho, Tin Zhang, Jiachen Butler, James Preble, Chelsea V Kirchstetter, Thomas W Ying, Qi Chen, Zichong Spurlock, Anna Breunig, Hanna https://escholarship.org/uc/item/52p7z80k Vehicles with electrified powertrains carry the promise of significant reductions in greenhouse gas (GHG) emissions from a lifecycle analysis (LCA) standpoint compared to conventional internal combustion engine (CICE) vehicles. However, trade-offs exist between different types of electrified powertrains in terms of cost, consumer acceptance, and GHG reduction efficacy for different operating conditions. The open-source tool CarGHG was developed with an aim to enable the exploration of a plethora of parametric study scenarios, including the cost of electrification technologies, different driving patterns and charging habits, and the cost and carbon intensity of electricity and fuel blends. This paper introduces the framework of CarGHG, then showcases total cost of ownership (TCO) and LCA GHG results for select models of light-duty vehicles. Another capability of CarGHG, which is the ability to estimate the performance of “virtual” vehicle models (perceived vehicle design specifications... https://escholarship.org/uc/item/52p7z80k Tue, 25 Aug 2026 00:00:00 +0000 Hamza, Karim Laberteaux, Kenneth Chu, Kang-Ching Benoliel, Peter https://orcid.org/0000-0003-0508-5675 https://escholarship.org/uc/item/4gt7h0d8 Upgrading electrical panels and services in U.S. homes represents a significant barrier to building modernization, imposing considerable costs, delays, and procedural uncertainties on homeowners, contractors, utilities, and building departments. Although cost databases document individual infrastructure activities, they rarely capture the integrated, whole-project perspective required to understand how electrical upgrades are planned, executed, and regulated. Existing research is often geographically constrained, narrowly scoped, or derived from limited samples, leaving significant knowledge gaps unaddressed. This study examines the timelines and costs associated with residential electrical panel and service upgrades using data from a national cross- sectional survey conducted in summer 2025. The survey captured responses from 140 stakeholders across 34 states, including building industry professionals, utility staff, and building department staff. Findings indicate that project... https://escholarship.org/uc/item/4gt7h0d8 Tue, 25 Aug 2026 00:00:00 +0000 Casquero-Modrego, Nuria https://orcid.org/0000-0001-5677-4142 Venkatraman,, Meena Gul, Sadia Less, Brennan Walker, Iain https://orcid.org/0000-0001-9667-1797 https://escholarship.org/uc/item/3s50n5w3 The favorable energy configurations of nuclei at magic numbers of N neutrons and Z protons are fundamental for understanding the evolution of nuclear structure. The Z=50 (tin) isotopic chain is a frontier for such studies, with particular interest at and around the doubly magic Sn100 isotope, for which the mass is a topic of debate. Precise mass values for neutron-deficient isotopes provide necessary anchor points for mass models to test extrapolations near the proton drip line, where experimental studies remain out of reach. In this work, we report a Penning trap mass measurement of Sn101. The determined mass excess of −59889.89(96) keV for Sn101 represents a factor-of-300 improvement over the current precision and indicates that Sn101 is less bound than previously thought. Mass predictions from a recently developed Bayesian model combination framework employing statistical machine learning and nuclear masses computed within seven global models based on nuclear density functional... https://escholarship.org/uc/item/3s50n5w3 Tue, 25 Aug 2026 00:00:00 +0000 Ireland, CM Bollen, G Campbell, SE Chen, X Erington, H Gamage, ND Godbey, K Houff, AM Izzo, C Knight, B Lalit, S Leistenschneider, E https://orcid.org/0000-0003-0377-8523 Lykiardopoulou, EM Maier, FM Nazarewicz, W Orford, R Porter, WS Quick, C Ravlić, A Redshaw, M Reinhard, P-G Ringle, R Schwarz, S Sumithrarachchi, CS Valverde, AA Villari, ACC https://escholarship.org/uc/item/3d94n54n Despite being recognized as the best practice for advanced building controls, ASHRAE Guideline 36 (G36) has seen slow adoption in retrofit cases. Decisionmakers lack credible field evidence to justify the time and person-power investment. Most prior analyses have relied on software simulations, which overlook implementation challenges and fail to persuade owners to move from models to real-world deployment. This paper presents a multi-site field study of G36 performance, drawing on measured results from 17 projects across diverse building types and climate zones. The analysis disaggregates outcomes by the most widely adopted air handling unit (AHU) based G36 strategies, including trim-and-respond approaches to supply air temperature (SAT) and duct static pressure (DSP) reset, and economizer controls. Results for controls re programming implementations are encouraging, with HVAC savings ranging from 2% - 49%, with a median of 18%. The range aligns with simulation study findings... https://escholarship.org/uc/item/3d94n54n Tue, 25 Aug 2026 00:00:00 +0000 Deshpande, Reva Casillas, Armando Velmurugan, Guhan Granderson, jessica https://escholarship.org/uc/item/39f7p4vn Accurately quantifying the energy use of artificial intelligence (AI) training is critical for infrastructure planning, carbon accounting, and sustainable data center operation, but few studies have directly measured the power consumption of production workloads on contemporary hardware. By combining empirical measurements from Brookhaven National Laboratory during AI training on 8-graphics-processing-unit H100 systems with open-source benchmarking data, we develop statistical models relating computational intensity to node-level power consumption. We measure the gap between manufacturer-rated thermal design power (TDP) and actual power demand during AI training. Our analysis reveals that even computationally intensive workloads operate at only 76% of the 10.2 kW TDP rating. Our architecture-specific model, calibrated to floating-point operations, predicts energy consumption with 11.4% mean absolute percentage error, significantly outperforming TDP-based approaches (27%–37% error).... https://escholarship.org/uc/item/39f7p4vn Tue, 25 Aug 2026 00:00:00 +0000 Newkirk, Alex C https://orcid.org/0000-0002-6213-6865 Fernandez, Jared Koomey, Jonathan Latif, Imran Strubell, Emma Shehabi, Arman https://orcid.org/0000-0002-1735-6973 Samaras, Constantine https://escholarship.org/uc/item/3582z6mq To meet California and the nation's ambitious energy targets, energy use in the building sector must drop dramatically. Windows continue to be the lowest thermally performing envelope system in the nation's buildings, resulting in poor overall envelope performance and potential impacts to human health and comfort. Current best practice new window performance is typically met by double-pane low-solar-gain glazing. Thin-glass triple-pane windows are a highly promising next step forward in performance and have been deployed in two California multi-family sites to quantify field performance and building energy savings. The technology assessed offers the performance benefits of traditional triple-pane but with little increase in weight or cost, enabling incremental costs competitive with alternative energy reduction solutions for the building envelope. This paper covers a detailed investigation into the demonstration project and measured performance benefits of the windows after a... https://escholarship.org/uc/item/3582z6mq Tue, 25 Aug 2026 00:00:00 +0000 Hart, Robert Yu, Tammie https://escholarship.org/uc/item/2d31n1h5 The authors regret the inaccuracy in the vertical axis title of Fig. 4 and the distortion in the legend of Fig. 13. Corrections have been made to the vertical axis title and legend of Figs. 4 and 13, respectively. These changes do not affect the analysis, calculations, or results in any way. The authors apologize for any inconvenience caused. The corrected figures are as follows: https://escholarship.org/uc/item/2d31n1h5 Tue, 25 Aug 2026 00:00:00 +0000 Zuberi, M Jibran S Shehabi, Arman https://orcid.org/0000-0002-1735-6973 Rao, Prakash https://escholarship.org/uc/item/26t5775g A series of electron and proton transfer reactions are carried out in photosynthetic reaction centers that convert the energy of light into high energy reduced products and add to the proton gradient. All photosynthetic reaction centers (photosystems I, II, and different bacterial reaction centers (bRCs)) have their charge separating cofactors arranged with two, <i>c</i>₂-symmetric paths from a primary donor to a terminal acceptor. In Type II reaction centers (PSII and bRCs), electrons utilize only one active branch. In bRCs the electron transfer occurs in the A branch from the excited state of the bacteriochlorophyll (BChl) dimer P₈₆₀ through BChl_A, bacteriopheophytin_A (BPh_A), to ubiquinone Q_A, and then to the B-branch Q_B. B-branch BChl_B and BPh_B do not participate. A similar path is found in PSII. These proteins challenge our understanding of how proteins can turn on or turn off... https://escholarship.org/uc/item/26t5775g Tue, 25 Aug 2026 00:00:00 +0000 Wei, Rongmei Judy Kirmaier, Christine Holten, Dewey Kern, Jan https://orcid.org/0000-0002-7272-1603 Laible, Philip D Hanson, Deborah K Ranepura, Gehan Uddin, Md Raihan Ortiz-Soto, Jose Gunner, MR https://escholarship.org/uc/item/0wk8n4bq The era of protein design has enabled the creation of hybrid protein-inorganic interfaces, leading to both surface-directed self-assembly of de novo protein architectures and protein-directed formation of inorganic materials. However, the resulting patterns of protein assembly are often unexpected, implying that essential interactions are not accounted for in current design platforms. Here, we use high-speed atomic force microscopy (AFM) analyzed through machine learning to follow the assembly of protein nanorods in aqueous electrolytes on two types of mica exhibiting disparate symmetry elements, which are imprinted on the overlying hydration structure. Using Monte Carlo simulations, we reproduce the observed phases and show that an observed smectic phase, previously thought to be unstable for non-interacting rods in two dimensions, emerges when crystal symmetry introduces a directional bias. The findings demonstrate the importance of incorporating solvent forces as modulated... https://escholarship.org/uc/item/0wk8n4bq Tue, 25 Aug 2026 00:00:00 +0000 Yadav Schmid, Sakshi Helfrecht, Benjamin Stegmann, Amy Legg, Benjamin A Pyles, Harley Chen, Jiajun Edison, John R Ziatdinov, Maxim Preisler, Zdenek Dollar, Orion Whitelam, Stephen Kalinin, Sergei Baker, David Mundy, Christopher J Zhang, Shuai De Yoreo, James J https://escholarship.org/uc/item/0d6956js Fired clay bricks (FCBs) are a dominant building material globally due to their low cost and simplicity of production, especially in low- and middle-income countries. With a projected rising housing demand, commensurate growth in brick demand is anticipated, the production of which could result in significant greenhouse gas (GHG) emissions. Robust models are needed to estimate brick demand and emissions to systematically address decarbonization pathways. Few sources report production values; hence, we present two novel proxy models: (i) a consumption prediction model, relying on country-specific clay extraction data, dynamic building stock modeling, and average material intensity use allowing for projections to 2050; and (ii) a GHG emissions model, using literature-based data and production technology-specific inputs. Based on these models, the current global FCB consumption is estimated as 2.18 Gt annually, resulting in approximately 500 million tCO₂e (1% of current... https://escholarship.org/uc/item/0d6956js Tue, 25 Aug 2026 00:00:00 +0000 Olsson, Josefine A Hafez, Hisham Miller, Sabbie A https://orcid.org/0000-0001-6888-7312 Scrivener, Karen L https://escholarship.org/uc/item/07w871b9 Satellite data provides essential insights into the spatiotemporal distribution of CO₂ concentrations. However, many atmospheric inverse models fail to adequately incorporate the spatial and temporal correlations inherent in satellite observations and often lack rigorous methods for estimating parameters like spatial length scales. We introduce an inference model that processes the spatiotemporal covariance in satellite data and estimates hyperparameters such as covariance length scales. Our approach uses the Gaussian process (GP) machine learning (ML) and modern probabilistic programming languages (PPLs) to perform atmospheric inversions of emissions from satellite data. We develop a GP ML inversion system based on modern PPLs and the GEOS-Chem chemical transport model, simulating atmospheric CO₂ concentrations corresponding to the Orbiting Carbon Observatory-2/3 (OCO-2/3) data for July 2020. In our supervised learning framework, we treat the GEOS-Chem simulated... https://escholarship.org/uc/item/07w871b9 Tue, 25 Aug 2026 00:00:00 +0000 Jeong, Seongeun https://orcid.org/0000-0003-2032-0127 Hamilton, Sofia D https://orcid.org/0000-0002-3662-5737 Johnson, Matthew S Wu, Dien Turner, Alexander J Fischer, Marc L https://escholarship.org/uc/item/9s82223j Abstract In recent years, machine‐learning (ML) models trained on reanalysis data have rivaled physics‐based forecast models in terms of performance skill for global weather forecasting. With increased rollout stability, the question of how these models perform for subseasonal to seasonal (S2S, week 3–8) forecasting has emerged. In this study we run a large set of subseasonal hindcasts over 2004–2023 to evaluate two ML weather forecast models at the S2S time scale, SFNO‐HENS (Nvidia, fully ML) and NeuralGCM (Google Research, hybrid). Corresponding hindcasts from the European Centre for Medium‐Range Weather Forecasts (ECMWF) are used as a baseline for comparison to a physics‐based model. Because our focus is on predicting moisture transport over the Western United States between October and March, we evaluate the models' prediction skill for the Madden‐Julian Oscillation (MJO) and its associated teleconnections in the North Pacific. We find that both ML models are competitive with... https://escholarship.org/uc/item/9s82223j Mon, 24 Aug 2026 00:00:00 +0000 Peings, Yannick https://orcid.org/0000-0001-6852-7333 Dong, Cameron Mahesh, Ankur Pritchard, Michael https://orcid.org/0000-0002-0340-6327 Collins, William https://orcid.org/0000-0002-4463-9848 Magnusdottir, Gudrun https://orcid.org/0000-0001-6079-5886 https://escholarship.org/uc/item/9rz5w9wj Supramolecular hydrogels that mimic the extracellular matrix (ECM) represent promising materials for tissue engineering and drug delivery. However, conventional hydrogels formed via the self-assembly of natural or synthetic building blocks often face a trade-off between biological functionality and biochemical stability, limiting their utility in long-term or protease-rich environments. Peptoids, a class of peptide-inspired, sequence-defined polymers, offer a compelling alternative due to their exceptional proteolytic resistance and bioactivity. Despite this potential, the development of supramolecular peptoid hydrogels has been hindered by the absence of backbone hydrogen bond donors, which limits long-range ordering necessary for efficient hydrogel formation. This work describes a short peptoid functionalized at the <i>N</i>-terminus with an octyl chain that readily self-assembles into hydrogels. Hydrophobic interactions among pendant octyl groups promote directional peptoid... https://escholarship.org/uc/item/9rz5w9wj Mon, 24 Aug 2026 00:00:00 +0000 Park, Il-Soo Cho, Younghak Lee, Yen Jea https://orcid.org/0000-0003-2699-8676 Gutierrez, Daniela Zuckermann, Ronald N Seong, Hyejeong Kim, Jae Hong https://escholarship.org/uc/item/9m6969ps The cost-effective and sustainable deployment of hydrogen supply and demand networks, especially in large economic regions like California, can be challenging considering the spatial-temporal availability and variability of the different actors across the network such as production processes, distribution modes, and end-users. In this presentation, we will provide an overview and demonstration of a modeling framework used to assess the environmental, economic, and human health impacts of plausible hydrogen production and supply chain networks in California. Scenarios focus on green hydrogen production pathways using water electrolysis and biomass gasification. End-use applications included in the model are transit, medium and heavy-duty trucking, port authorities, and power and aviation companies that currently consume natural gas, diesel, and aviation fuel for their day-to-day operation. Representative locations for hydrogen production and end-use are based on recent projections... https://escholarship.org/uc/item/9m6969ps Mon, 24 Aug 2026 00:00:00 +0000 Zaki, Mohammed Tamim https://orcid.org/0000-0002-7197-0608 Jeong, Seongeun Weber, Adam Z https://orcid.org/0000-0002-7749-1624 Breunig, Hanna https://escholarship.org/uc/item/8m42g0t5 Manure management and land application can improve soil health and nutrient recycling but can also be a major source of air pollutant emissions and regional eutrophication. A high-resolution, regional framework can now facilitate assessment of current and future manure management policies in a representative livestock-dense region of Europe. https://escholarship.org/uc/item/8m42g0t5 Mon, 24 Aug 2026 00:00:00 +0000 Harrison, Brendan P Leonhardt, Branden E Englander, Jacob G Scown, Corinne D https://orcid.org/0000-0003-2078-1126 https://escholarship.org/uc/item/83m894pd Zero-shot and prompt-based models have excelled at visual reasoning tasks by leveraging large-scale natural image corpora, but they often fail on sparse and domain-specific scientific image data. We introduce Zenesis, a no-code interactive computer vision platform designed to reduce data readiness bottlenecks in scientific imaging workflows. Zenesis integrates lightweight multimodal adaptation for zero-shot inference on raw scientific data, human-in-the-loop refinement, and heuristic-based temporal enhancement. We validate our approach on Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) datasets of catalyst-loaded membranes. Zenesis outperforms baselines, achieving an average accuracy of 0.947, Intersection over Union (IoU) of 0.858, and Dice score of 0.923 on amorphous catalyst samples; and 0.987 accuracy, 0.857 IoU, and 0.923 Dice on crystalline samples. These results represent a significant performance gain over conventional methods such as Otsu thresholding and standalone... https://escholarship.org/uc/item/83m894pd Mon, 24 Aug 2026 00:00:00 +0000 Mukherjee, Shubhabrata Lang, Jack Kwon, Obeen https://orcid.org/0000-0002-7950-4820 Zenyuk, Iryna https://orcid.org/0000-0002-1612-0475 Brogden, Valerie Weber, Adam https://orcid.org/0000-0002-7749-1624 Ushizima, Daniela https://orcid.org/0000-0002-7363-9468 https://escholarship.org/uc/item/7st2q0bd Direct methane conversion to liquid fuels or value-added chemicals is a promising technology to utilize natural resources without resorting to further petroleum extraction. However, discovering efficient catalysts for this reaction is challenging due to either coke formation or unfavorable C-H bond activation. Herein, we design single-atom alloy (SAA) catalysts to simultaneously eliminate the above two bottlenecks based on mechanism-guided strategies: (1) the active single atom enables favorable C-H bond breaking and (2) the less reactive host metal facilitates C-C coupling and thus avoids strong binding of carbonaceous species. Employing electronic structure theory calculations, we screened the stability of multiple SAAs with 3d-5d transition metals atomically dispersed on a copper surface in terms of avoiding dopant aggregation and segregation. We then evaluated reactivities of the stable SAAs as catalysts for direct methane conversion to C₂ products, including methane... https://escholarship.org/uc/item/7st2q0bd Mon, 24 Aug 2026 00:00:00 +0000 Kothakonda, Manish LaCroix, Sarah Zhou, Chengyu Yang, Ji Su, Ji Zhao, Qing https://escholarship.org/uc/item/7rs224s8 Buildings significantly impact worldwide energy consumption, emphasizing the need to reduce the cooling energy demand, especially in warm climates. Minimum energy performance standards (MEPS) and seasonal performance metrics such as the Cooling Seasonal Performance Factor (CSPF) are crucial for improving room air conditioning (RAC) efficiency. However, challenges remain, particularly in emerging markets like Brazil, where seasonal performance metrics have recently been introduced. This study assesses the factors influencing country-level seasonal efficiency metrics and proposes a framework to refine these calculations by considering local climates and expected RAC usage in real-world households via building simulations. Key considerations include outdoor air temperature binning for different climates, RAC usage patterns (i.e., daytime and nighttime usages), envelope thermal performance of households, and urban heat island (UHI) effects. The results reveal that CSPF values can... https://escholarship.org/uc/item/7rs224s8 Mon, 24 Aug 2026 00:00:00 +0000 Bavaresco, Mateus Machado, Rayner Maurício E Silva Krelling, Amanda F https://orcid.org/0000-0003-2585-4320 Melo, Ana Paula Park, Won Young Lamberts, Roberto https://escholarship.org/uc/item/7jn1x8dp Hydrogen (H₂) is experiencing renewed interest throughout the world as a low carbon fuel alternative or complement to fossil fuels. Significant uncertainties remain regarding the environmental impact of increasing H₂ usage, in part due to gaps in our understanding of the H₂ atmospheric budget, including the H₂ release from industrial activities and the H₂ soil removal, the most important sink of H₂. This study focuses on H₂ dry air mole fractions measured by the NOAA Global Monitoring Laboratory in discrete ambient air samples collected every few days at sites located in the contiguous United States between 2010 and 2022. We take advantage of the long-term observations from this network to study the regional distribution of H₂ sources using the potential source contribution function (PSCF). We find that H₂ PSCF is consistent with a large anthropogenic source of atmospheric H₂... https://escholarship.org/uc/item/7jn1x8dp Mon, 24 Aug 2026 00:00:00 +0000 Paulot, Fabien Pétron, Gabrielle Crotwell, Andrew Crotwell, Molly Handley, Philip Kofler, Jonathan Madronich, Monica Mefford, Thomas Moglia, Eric Mund, John Thoning, Kirk Biraud, Sébastien C Andrews, Arlyn https://escholarship.org/uc/item/7h8056bh India is poised for a rapid surge in space cooling demand, driven by rising incomes, urbanization, and intensifying heat. Between 2025 and 2035, the country is expected to add 130–150 million new room air conditioners (ACs). If Minimum Energy Performance Standards (MEPS) continue to improve at the historical rate of 2–3 % annually, room ACs alone could contribute over 180 GW to peak electricity demand by 2035-nearly 30 % of the projected national total. This study evaluates the impact of an accelerated MEPS trajectory, proposing to raise the 1-star threshold to ISEER 5.0 by 2027, ISEER 6.3 by 2030, and ISEER 7.4 by 2033. Drawing on engineering cost analysis, stock turnover modeling, and retail pricing data, we find that this pathway could reduce peak demand by over 60 GW, save 118 TWh of electricity annually, avoid 49 MtCO₂ of electricity-related emissions per year, avert ₹7.5 trillion (∼US$85 billion) in power system investments, and yield ₹0.7–2.3 trillion (∼US$8–26 billion)... https://escholarship.org/uc/item/7h8056bh Mon, 24 Aug 2026 00:00:00 +0000 Abhyankar, Nikit https://orcid.org/0000-0003-3383-8558 Dominguez, Jose Shah, Nihar https://orcid.org/0000-0002-2500-0483 Jain, Neelima Phadke, Amol https://orcid.org/0000-0002-2607-1689