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At least 199 records · Page 11

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DOE OSTI2024

Analyzing Residential Charging Demand for Light-Duty Electric Vehicles in Colorado: Preprint

The past decade has witnessed the rapid adoption of electric vehicles (EVs). The momentum is expected to continue with strong support from the government and industry. Rapid EV adoption brings significant charging demand to the power grid, causing additional stress and non-negligible risks to the already-aging power grid. To help power grid operators understand the impacts of EV home charging on the grid and identify risk factors, this study presents a data-driven residential charging demand analysis for light-duty vehicles. This study considers two real-world grid service regions in Colorado and merges multiple data sources and state-of-the-art tools that characterize EV adoption projections, vehicle travel patterns, seasonal variations, residential charging accessibility, ambient temperature impact, EV charging behaviors, grid utility customers, vehicle registration, and household-level EV charging demand distribution. We characterize potential residential charging demand in 2030 for two regions within the state of Colorado: Boulder and Aurora. We project that EVs will be 26% of the light-duty vehicle population in Boulder and 16% in Aurora. Charging demand is characterized for ten power grid feeders (five for each study region). Across the ten feeders, peak total EV charging powers during wintertime range from less than 1 MW to more than 4 MW.

ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2025

Laser ablation of high-loading Li-ion battery electrodes improves accessible capacity and cycle life for Behind-the-Meter Storage

Adoption of Behind-the-Meter Storage (BTMS) requires design of batteries that enable high safety, long cycle life, and low cost at the system level. Pairing Li 4 Ti 5 O 12 (LTO) with LiMn 2 O 4 (LMO) achieves targets related to safety and cycle life, but these materials' low energy densities contribute to higher cost at the system scale. Increasing electrode loading is a simple approach to improve energy density, but comes with a trade-off in electrode utilization due to long, tortuous Li + diffusion pathways. Here, laser ablation is used to microstructure (pattern) high-loading electrodes to enhance electrode performance through improved Li + diffusion pathways. Four cell types, comprising combinations of standard or patterned anode and cathode, were prepared to evaluate the effects of laser ablation at each electrode. A rate test shows that patterning electrodes enhances active material utilization at ≳1C rates. Patterning the cathode yields the most benefit, as cells with a patterned cathode demonstrate a ~20% higher accessible capacity than those without at 1.4C. Additionally, 1C capacity retention of cells with patterned cathode (91% through 3000 cycles) is significantly improved over cells with only the anode patterned (64%) and non-patterned electrodes (50%). Characterization of post-mortem cells before and after refreshing their electrolyte suggests that 1C capacity retention is improved by mitigation of electrode "dry-out". We hypothesize that the microstructure acts as a reservoir of additional electrolyte, or a path for gas to escape, so that active material remains wetted throughout long-term cycling, and/or the microstructure may reduce localized, gas-forming overpotentials in the high-loading electrode.

25 ENERGY STORAGE↗

DOE OSTI2021

Transcriptional network orchestrating regional patterning of cortical progenitors

We uncovered a transcription factor (TF) network that regulates cortical regional patterning in radial glial stem cells. Screening the expression of hundreds of TFs in the developing mouse cortex identified 38 TFs that are expressed in gradients in the ventricular zone (VZ). We tested whether their cortical expression was altered in mutant mice with known patterning defects (Emx2, Nr2f1, and Pax6), which enabled us to define a cortical regionalization TF network (CRTFN). To identify genomic programming underlying this network, we performed TF ChIP-seq and chromatin-looping conformation to identify enhancer–gene interactions. To map enhancers involved in regional patterning of cortical progenitors, we performed assays for epigenomic marks and DNA accessibility in VZ cells purified from wild-type and patterning mutant mice. This integrated approach has identified a CRTFN and VZ enhancers involved in cortical regional patterning in the mouse.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2021

Conserved and reproducible bacterial communities associate with extraradical hyphae of arbuscular mycorrhizal fungi

Abstract Extraradical hyphae (ERH) of arbuscular mycorrhizal fungi (AMF) extend from plant roots into the soil environment and interact with soil microbial communities. Evidence of positive and negative interactions between AMF and soil bacteria point to functionally important ERH-associated communities. To characterize communities associated with ERH and test controls on their establishment and composition, we utilized an in-growth core system containing a live soil–sand mixture that allowed manual extraction of ERH for 16S rRNA gene amplicon profiling. Across experiments and soils, consistent enrichment of members of the Betaproteobacteriales, Myxococcales, Fibrobacterales, Cytophagales, Chloroflexales, and Cellvibrionales was observed on ERH samples, while variation among samples from different soils was observed primarily at lower taxonomic ranks. The ERH-associated community was conserved between two fungal species assayed, Glomus versiforme and Rhizophagus irregularis, though R. irregularis exerted a stronger selection and showed greater enrichment for taxa in the Alphaproteobacteria and Gammaproteobacteria. A distinct community established within 14 days of hyphal access to the soil, while temporal patterns of establishment and turnover varied between taxonomic groups. Identification of a conserved ERH-associated community is consistent with the concept of an AMF microbiome and can aid the characterization of facilitative and antagonistic interactions influencing the plant-fungal symbiosis.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2019

Measurement and modeling of magnetic configurations to mimic overload scenarios in the W7-X stellarator

Experiments were performed during the first divertor operational phase (OP1.2a) of the Wendelstein 7-X stellarator to verify predictions of potential overload conditions corresponding to certain high-power long-pulse OP2 scenarios. A potential solution to this overload is the installation of new divertor components called scraper elements, which are designed to intercept heat flux that would otherwise be incident on low-rated divertor edges. Heat flux measurements were obtained in a series of magnetic configurations designed to mimic the magnetic topology evolution caused by net toroidal current and beta, which is not directly accessible in OP1.2a. The experimental flux patterns are qualitatively reproduced in position and magnitude for by field line diffusion simulations using ad hoc cross-field diffusivities near the value used to design the scraper element. However, some important differences are observed, including a shift towards the pumping gap and low-rated components. Potential sources of discrepancy such as toroidal current evolution and error fields are discussed. In conclusion, a shift in the experimental heat flux pattern due to increasing toroidal current is observed in a 12 s discharge.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2025

Exploring the Utility-Privacy Trade-Off: Impacts of Semantic and Visit Types Ambiguities on Human Mobility Simulation

Humans are in perpetual movement, constantly traversing buildings, cities, waters, oceans, and countries. Mobility stands out as a major driving force shaping our modern societies. Capturing and explaining human behavior in a world of eight billion distinct mobility agendas is a complex challenge. With the rise of interconnected devices and platforms, such as smartphones, wearables, and point-of-interest data, largescale behavioral data has become more accessible, enabling rich insights into mobility patterns. However, the widespread availability of such data introduces significant ethical challenges. Detailed mobility data can inadvertently reveal sensitive personal information, including individuals' locations, habits, social interactions, and even political or religious affiliations. Beyond privacy breaches, the ethical implications of uncovering and potentially manipulating underlying behavioral patterns demand attention. Striking a balance between the utility of mobility models and the protection of individual privacy is therefore paramount. This paper explores the utility-privacy trade-offs in human mobility modeling, focusing on the impacts of introducing semantic and visit type ambiguities. By systematically examining how these ambiguities affect the fidelity of simulated trajectories and privacy risks, we provide a framework for evaluating ethical and privacy-conscious modeling practices. Our findings emphasize the need for methods that safeguard privacy without undermining the usefulness of mobility models, contributing to the responsible advancement of mobility science in alignment with ethical standards and societal expectations.

Amichi, Licia [ORNL] (ORCID:0000000177631394)↗

DOE OSTI2016

A Weather Radar Simulator for the Evaluation of Polarimetric Phased Array Performance

A radar simulator capable of generating time series data for a polarimetric phased array weather radar has been designed and implemented. The received signals are composed from a high-resolution numerical prediction weather model. Thousands of scattering centers, each with an independent randomly generated Doppler spectrum, populate the field of view of the radar. The moments of the scattering center spectra are derived from the numerical weather model, and the scattering center positions are updated based on the three-dimensional wind field. In order to accurately emulate the effects of the system-induced cross-polar contamination, the array is modeled using a complete set of dual-polarization radiation patterns. The simulator offers reconfigurable element patterns and positions as well as access to independent time series data for each element, resulting in easy implementation of any beamforming method. It also allows for arbitrary waveform designs and is able to model the effects of quantization on waveform performance. Simultaneous, alternating, quasi-simultaneous, and pulse-to-pulse phase coded modes of polarimetric signal transmission have been implemented. This framework allows for realistic emulation of the effects of cross-polar fields on weather observations, as well as the evaluation of possible techniques for the mitigation of those effects.

phased array↗

DOE OSTI2025

CareWELL: Multimodal Region Representation Learning with Spatial Contexts for Urban Health

Rapid urbanization affects living environments by intensifying exposure to air pollution, heat, noise, and urban dynamics, which together contribute to uneven health outcomes across neighborhoods. For instance, cardiovascular, respiratory, and mental health conditions are each influenced by distinct exposures such as air pollution, extreme temperatures, or limited access to green space. These heterogeneous patterns require understanding the characteristics of geographic regions in order to explain why urban health risks vary across urban areas. Recent work in self-supervised region representation learning provides a promising way to model such characteristics from multimodal geospatial data. However, existing methods face two major limitations: (i) they often depend on non-public datasets, limiting reproducibility and applicability, and (ii) their generic pretraining objectives overlook health-relevant determinants, including temporal variability in environmental exposures and inequalities in social conditions. To address these gaps, we propose Context-Aware Region rEpresentation with Weather, Environment, and Location Learning (CareWELL). CareWELL leverages large language models to encode seasonal variability in weather, employs contrastive learning to align geo-coordinate and weather representations, and introduces a context-aware objective that integrates socio-demographic factors while preserving spatial correlations. We evaluate CareWELL by predicting six urban health outcomes in Manhattan, New York City, and demonstrate that CareWELL consistently outperforms state-of-the-art baselines as well as a traditional spatial computing method. These results suggest the importance of context-aware pretraining objectives for learning health-relevant region representations.

Namgung, Min [ORNL]↗

DOE OSTI2026

Transit Survey - Miami-Dade Metrorail - 2009

This Miami-Dade Metrorail Survey obtained ridership characteristics such as origin-destination patterns, trip purpose, and mode of access and egress. The data obtained from this survey was used to update and validate the Southeast Regional Planning Model (SERPM v6.5) and for transportation planning in the region.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

NASA NTRS1984

Temporal evolution of the solar wind and the formation of a standing shock

The temporal evolution of the solar wind from one steady state to another is explored when momentum deposition produces multiple critical points in the flow. It is shown that the wind always evolves in time to a new steady state compatible with the solution of the steady state equation of motion. However, for the same initial state and identical asymptotic momentum deposition rate, the temporal evolution pattern of the wind depends on the detailed time history of momentum addition and is therefore not unique. This feature plays an important role in the particular case when multiple (three in this study) steady states exist for identical boundary conditions; each one of these solutions is thus shown to be physically accessible. The details of the temporal evolution pattern of the wind reveal the formation of a shock discontinuity whenever the flow becomes supersonic at a critical point upstream from the initial critical point. If the flow remains supersonic at that inner critical point, the shock can become a standing one, depending on the strength and the temporal history of momentum addition. The results of this study indicate that the time scale required for the solar wind to evolve between steady states is of the order of 30-60 hours. Furthermore, the results also reveal the interesting and novel phenomenon that a standing shock is likely to develop in the inner solar wind flow within this time frame, in particular, in coronal hole regions with rapidly diverging geometries.

Habbal, S. R.↗

NASA NTRSDate not supplied

Speckle Pattern Application to Woven Softgoods

Space habitation is becoming more accessible and commercially available which is driving the development and testing of inflatable softgoods habitats that can be both lighter and more volume-efficient than heritage metallic pressure vessels. Photogrammetry test methods are used on new materials and larger inflatable softgood test articles to measure material displacement and strain during pressurization. A speckle pattern must be applied to the surface of interest for testing when using photogrammetry which is typically a very labor and time intensive process. Two methods were tested as options for a faster and more effective application to hand painting and temporary tattoos, which are the current application methods for the structural/restraint layer. One approach was to mix a plastic additive with a matte clear coat to create a speckle pattern that could be applied to the article. The second method uses a speckle paint gun to speckle the article after a white base coat is applied. Both methods adhered well to the Kevlar test sample materials and showed up well when examined with photogrammetry cameras. On the woven test samples the additive in a clear coat method could be applied evenly as was the paint gun method.

Rylee Cardon↗

NASA NTRSDate not supplied

Speckle Pattern Application to Woven Softgoods

Rylee Cardon↗

DOE OSTI2024

In Search of Optimum Fresh-Cut Raw Material: Using Computer Vision Systems as a Sensory Screening Tool for Browning-Resistant Romaine Lettuce Accessions

The popularity of ready-to-eat (RTE) salads has prompted novel technology to prolong the shelf life of their ingredients. Fresh-cut romaine lettuce is widely used in RTE salads; however, its tendency to quickly discolor continues to be a challenge for the industry. Selecting the ideal lettuce accessions for use in RTE salads is essential to ensure maximum shelf life, and it is critical to have a practical way to assess and compare the quality of multiple lettuce accessions that are being considered for use in fresh-cut applications. Thus, in this work we aimed to determine whether a computer vision system (CVS) composed of image acquisition, processing, and analysis could be effective to detect visual quality differences among 16 accessions of fresh-cut romaine lettuce during postharvest storage. The CVS involved a post-capturing color correction, effective image segmentation, and calculation of a browning index, which was tested as a predictor of quality and shelf life of fresh-cut romaine lettuce. The results demonstrated that machine vision software can be implemented to replace or supplement the scoring of a trained panel and instrumental quality measurements. Overall visual quality, a key sensory parameter that determines food preferences and consumer behavior, was highly correlated with the browning index, with a Pearson correlation coefficient of −0.85. Other important sensory decision parameters were also strongly or moderately correlated with the browning index, with Pearson correlation coefficients of −0.84 for freshness, 0.79 for off odor, and 0.57 for browning. The ranking of the accessions according to quality acceptability from the sensory evaluation produced a similar pattern to those obtained with the CVS. This study revealed that multiple lettuce accessions can be effectively benchmarked for their performance as fresh-cut sources via a CVS-based method. Future opportunities and challenges in using machine vision image processing to predict consumer preferences for RTE salad greens is also discussed.

Agriculture↗

DOE OSTI2017

Element-resolved Kikuchi pattern measurements of non-centrosymmetric materials

Angle-resolved electron Rutherford backscattering (ERBS) measurements using an electrostatic electron energy analyser can provide unique access to element-resolved crystallographic information. We present Kikuchi pattern measurements of the non-centrosymmetric crystal GaP, separately resolving the contributions of electrons backscattered from Ga and P. In comparison to element-integrated measurements like in the method of electron backscatter diffraction (EBSD), the effect of the absence of a proper 4-fold rotation axis in the point group of GaP can be sensed with a much higher visibility via the element-resolved Ga to P intensity ratio. These element-resolved measurements make it possible to experimentally attribute the previously observed point-group dependent effect in element-integrated EBSD measurements to the larger contribution of electrons scattered from Ga compared to P. - Highlights: •Element specific Kikuchi patterns are presented for GaP. •Absence of a proper four-fold rotation axis is demonstrated. •Ga and P intensity variations after 90 degree rotation have opposite phase. •The asymmetry in the total intensity distribution resembles that of Ga.

36 MATERIALS SCIENCE↗

DOE OSTI2024

Systems, devices, and methods for authenticating millimeter wave devices

Systems, devices, and methods are described for millimeter wave device authentication. A system may include one or more access points. Each access point of the one or more access points is configured to extract, from one or more beam patterns generated via a client device, a beam feature associated with the client device. Each access point may also be configured to transmit the beam feature. The system may also include a server communicatively coupled to the one or more access points and including a database for storing known beam features. The server may be configured to receive the beam feature associated with the client device from at least one access point of the one or more access points. Also, the server may be configured to authenticate the client device in response to the received beam feature matching a known beam feature stored in the at least one database.

Bhuyan, Arupjyoti↗

DOE OSTI2022

Supply sunspots and shadows: Business siting patterns and inequitable rooftop solar adoption in the United States

Entrepreneurs in certain industries tend to locate new businesses in relatively affluent areas. Preferences to site businesses in affluent areas can reduce low-income household access to certain products. Some argue that business siting patterns could explain inequitable consumption patterns, though such causal claims are often empirically weak. Here, we explore whether business siting patterns partly explain inequitable adoption of rooftop solar photovoltaics in California. We show that solar business formation drives an immediate and sustained increase in local solar adoption, including in low-income areas. However, solar business siting patterns have only weak impacts on solar adoption equity. The data show how solar businesses headquartered in low-income areas nonetheless install solar for relatively affluent customers. Customer-level adoption inequity partly offsets the potential equity gains of siting more businesses in low-income areas. We discuss how the emergent nature and unique business model of rooftop solar help explain these nuanced results.

14 SOLAR ENERGY↗

DOE OSTI2017

Patterns of Care in Adjuvant Therapy for Resected Oral Cavity Squamous Cell Cancer in Elderly Patients

Purpose: To characterize the patterns of care and potential barriers to access to care for elderly patients with oral cavity cancer in the adjuvant setting. Methods and Materials: We performed a retrospective cohort study using the National Cancer Data Base and identified patients with resected oral cavity squamous cell carcinoma diagnosed between 2004 and 2012, who survived for ≥3 months after surgery. We used logistic regression models to assess the association between age (<70, 70-79, and ≥80 years) and the receipt of adjuvant therapy within 3 months of surgery. We additionally assessed the association between patient and tumor characteristics and the receipt of adjuvant therapy among those aged ≥70 years. Results: A total of 25,829 patients were included in the study. Compared with those aged <70 years, older patients were more likely to have no neck dissection or have fewer lymph nodes dissected and were less likely to receive adjuvant therapy than younger patients. Among our cohort, 11,361 patients (44%) had pathologic T3-T4 disease or N2-N3 disease, and 4185 patients (16%) had extracapsular nodal extension or positive surgical margins. In multivariate analyses controlling for comorbidity and demographic characteristics, older age was independently associated with lower odds of receiving adjuvant radiation therapy in the subgroup with T3 or T4 disease or N2 or N3 disease and adjuvant chemoradiation therapy in the positive extracapsular nodal extension or positive surgical margin subgroup. Among elderly patients, both greater patient distance from reporting facility and older age were associated with lower odds of receiving both adjuvant radiation therapy (odds ratio 0.66; 95% confidence interval, 0.55-0.81) and chemoradiation therapy (odds ratio 0.56; 95% confidence interval, 0.40-0.79). Conclusions: In a national hospital-based cohort of patients with oral cavity cancer, elderly patients were less likely to receive adjuvant radiation or chemoradiation therapy. Greater patient distance from reporting facility, in addition to older age, was associated with lower odds of receiving both adjuvant radiation therapy and adjuvant chemoradiation therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2018

Atomically precise graphene etch stops for three dimensional integrated systems from two dimensional material heterostructures

Atomically precise fabrication methods are critical for the development of next-generation technologies. For example, in nanoelectronics based on van der Waals heterostructures, where two-dimensional materials are stacked to form devices with nanometer thicknesses, a major challenge is patterning with atomic precision and individually addressing each molecular layer. Here we demonstrate an atomically thin graphene etch stop for patterning van der Waals heterostructures through the selective etch of two-dimensional materials with xenon difluoride gas. Graphene etch stops enable one-step patterning of sophisticated devices from heterostructures by accessing buried layers and forming one-dimensional contacts. Graphene transistors with fluorinated graphene contacts show a room temperature mobility of 40,000 cm 2 V -1 s -1 at carrier density of 4 × 10 12 cm -2 and contact resistivity of 80 Ω·μm. We demonstrate the versatility of graphene etch stops with three-dimensionally integrated nanoelectronics with multiple active layers and nanoelectromechanical devices with performance comparable to the state-of-the-art.

36 MATERIALS SCIENCE↗