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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Autonomous Emergency Landing for Fixed-Wing Aircraft with Energy-Constrained Closed-Loop Prediction

Here this paper presents a new approach for autonomous motion planning for aircraft suffering from a loss-of-thrust emergency. Specifically, we show how modifications to the Closed-Loop Rapidly exploring Random Trees (CL-RRT) framework combined with controlled energy dissipation can enable rapid and effective kinodynamic motion planning. This CL-RRT Glide algorithm uses closed-loop prediction not only for node connections but also to estimate the remaining energy and prune infeasible paths. This greatly speeds up the search process, which is essential for emergency situations. In addition, we improve the ability of the gliding aircraft to reach a goal position and energy state. We do so by creating a Dissipative Total Energy Control Scheme (TECS). Dissipative TECS enables the glider to lose excess altitude in order to reach a desired energy level. Simulation results illustrate how the proposed methods enable faster motion planning. We also integrate the system into a small unmanned aerial vehicle system and experimentally demonstrate autonomous glide planning and execution during a motor-failure event. This type of algorithm can primarily benefit unmanned aircraft but can also serve to assist pilots in stressful emergency situations.

42 ENGINEERING↗
DOE OSTI2016

LAB SAFETY: Responding to an Emergency at Berkeley Lab

Berkeley Lab's Protective Services team stages an annual emergency exercise event to test and practice the response and coordination needed for large scale emergency at the lab. The procedures, planning, and training brought to life in these scenarios helps teams become better prepared for an actual event.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2021

Comprehensive Performance Calibration Guidance for Perovskites and Other Emerging Solar Cells

Emerging photovoltaic (PV) technologies (e.g., organic, perovskite, and solution processed quantum dot) have attracted remarkable attention with the rapid growth of their efficiencies, and their transition toward commercialization. Accurate and reliable efficiency measurements of these PV technologies are crucial, yet much more complicated than for conventional PV technologies due to the former's pronounced dynamic responses to changes in measurement conditions (e.g., current–voltage (I–V) scan rate and preconditioning) and their susceptibility to degradation. Adjustments to the measurement procedures are therefore necessary so that a reproducible “steady state” is reached during measurement. Furthermore, given the small size of many emerging cells, inappropriate device area definition and solar simulator setup can lead to measurement errors. Here, comprehensive efficiency calibration guidance is offered for emerging solar cells, including area measurement; spectral irradiance translation to standard test conditions; and steady-state electrical performance. The necessity of reporting steady-state efficiency is justified with a statistical performance comparison between conventional and steady-state I–V scans over hundreds of cells the group has received globally for efficiency certifications. The procedures described here do not require specialized measurement instrumentation; what matters most are changes to the measurement protocols. These described changes aim to enable better comparisons between reported efficiencies.

14 SOLAR ENERGY↗
DOE OSTI2024

Gopakumar-Vafa invariants and the Emergent String Conjecture

Abstract The Emergent String Conjecture of Lee, Lerche, and Weigand holds that every infinite-distance limit in the moduli space of a quantum gravity represents either a decompactification limit or an emergent string limit in some duality frame. Within the context of 5d supergravities coming from M-theory compactifications on Calabi-Yau threefolds, we find evidence for this conjecture by studying (a) the gauge couplings and (b) the BPS spectrum, which is encoded in the Gopakumar-Vafa invariants of the threefold. In the process, we disuss a testable geometric consequence of the Emergent String Conjecture, and we verify that it is satisfied in all complete intersection Calabi-Yau threefolds in products of projective spaces (CICYs).

Physics↗
DOE OSTI2015

Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasation of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Efficacy of Automated Supplying Artery Tracking Software Using Multidetector-Row Computed Tomography Images for Emergent Transcatheter Arterial Embolization

PurposeTo assess the reliability of a prototype automated supplying artery tracking software (ASATS) using multidetector-row CT (MDCT) images in emergent TAE.Materials and MethodsConsecutive 53 patients underwent 57 sessions of emergent TAE during 7 months. Twenty-one cases were excluded due to a lack of CT data (n = 12) or negative angiographic findings (n = 9). Remaining 34 sessions of TAE and MDCT images in 32 patients (mean age 62.9 years; age range 37–92 years) were enrolled. ASATS was retrospectively conducted for the identification of supplying arteries which were confirmed with angiography (automated method). Manual modification was added as needed (semi-automated method). Two observers independently reviewed the MDCT images to detect supplying arteries (manual method). Detectability of supplying artery and time to analysis were compared among the automated, semi-automated, and manual methods by both observers.ResultsA total of 64 bleeding sites were demonstrated on angiography. The detectability was 28 (43.8%) for automated method, 53 (82.8%) for semi-automated method, 55 (85.9%) for observer 1, and 58 (90.6%) for observer 2. Detectability of semi-automated method was significantly better than of automated method (P = 0.000) and comparable with manual method by both observers (P = 0.193 and 0.081). Average time to analysis was 185.4 s for automated method, 297.2 s for semi-automated method, 186.2 s for observer 1, and 243.7 s for observer 2.ConclusionASATS has a sufficient ability to identify supplying arteries of bleeding by adding manual modification as needed and can be used for emergent TAE. Level of Evidence: Level 4, Case Control Study.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Utilization of stress testing for low-risk patients with chest discomfort in the emergency department

Background: The management of patients presenting to an emergency department with chest discomfort at low-risk for acute coronary syndrome represents a common clinical challenge. Such patients are often triaged to chest pain units for monitoring and cardiac stress testing for further risk stratification. Methods: We conducted a retrospective study of 292 low-risk patients who presented to an emergency department with chest discomfort. We performed physician-adjudicated chart reviews of all patients with positive stress tests to assess downstream testing, subsequent coronary revascularization, and outcomes. Results: Of the 292 patients, 33 (11.3%) had stress tests positive for ischemia, and 12 (4.1%) underwent diagnostic cardiac catheterization. Of the 292 patients, 4 (1.4%) underwent coronary revascularization that may have resulted in a mortality benefit. Conclusion: These data suggest a very low yield of detecting clinically significant coronary disease with stress testing low-risk patients with chest discomfort in emergency department chest pain units.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Emergent geometry experienced by fermions in graphene in the presence of dislocations

In graphene in the presence of strain the elasticity theory metric naturally appears. However, this is not the one experienced by fermionic quasiparticles. Fermions propagate in curved space, whose metric is defined by expansion of the effective Hamiltonian near the topologically protected Fermi point. We discuss relation between both types of metric for different parametrizations of graphene surface. Next, we extend our consideration to the case, when the dislocations are present. We consider the situation, when the deformation is described by elasticity theory and calculate both torsion and emergent magnetic field carried by the dislocation. The dislocation carries singular torsion in addition to the quantized flux of emergent magnetic field. Both may be observed in the scattering of quasiparticles on the dislocation. Emergent magnetic field flux manifests itself in the Aharonov–Bohm effect while the torsion singularity results in Stodolsky effect.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2018

Mitochondria-associated membranes (MAMs): An emerging platform connecting energy and immune sensing to metabolic flexibility

Highlights: • Both mitochondria and MAMs recently emerge as key nutrient and immune sensors. • MAMs are key hub connecting energy and immune sensing to metabolic flexibility. • ER-mitochondria miscommunication is involved in metabolic diseases. Living organisms have the capacity to sense both nutrients and immune signals in order to adapt their metabolism to the needs, and both metabolic inflexibility and exacerbated immune responses are associated with metabolic diseases. Over the past decade, mitochondria emerged as key nutrient and immune sensors regulating numerous signalling pathways, and mitochondria dysfunction has been extensively implicated in metabolic diseases. Interestingly, mitochondria interact physically and functionally with the endoplasmic reticulum (ER, in contact sites named mitochondria-associated membranes (MAMs), in order to exchange metabolites and calcium and regulate cellular homeostasis. Emerging evidences suggest that MAMs provide a platform for hormone and nutrient signalling pathways and for innate immune responses, then regulating mitochondrial bioenergetics and apoptosis. Here, I thus propose the concept that MAMs could be attractive nutrient and immune sensors that regulate mitochondria physiology in order to adapt metabolism and cell fate, and that organelle miscommunication could be involved in the metabolic inflexibility and the pro-inflammatory status associated with metabolic diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Early emergence of de novo EGFR T790M gatekeeper mutations during erlotinib treatment in PC9 non-small cell lung cancer cells

The emergence of the T790M gatekeeper mutation in the Epidermal Growth Factor Receptor (EGFR) gene is an important mechanism that can lead to the acquired resistance to EGFR-targeted tyrosine kinase inhibitors such as erlotinib or gefitinib. These drugs have been used in treating a subset of non-small cell lung cancer (NSCLC) patients harboring EGFR activating mutations. Here we investigated the paths leading to the acquisition of the T790M mutation by establishing an erlotinib resistant PC9 cell model harboring ectopically introduced EGFR cDNA. We detected the emergence of T790M mutation within the EGFR cDNA in a subset of erlotinib resistant PC9 cell models through Sanger sequencing and droplet digital PCR-based methods, demonstrating that T790M mutation can emerge via de novo events following treatment with erlotinib. In addition, we show that the de novo T790M bearing erlotinib resistant PC9 cells are sensitive to the 3rd generation EGFR-targeted drug, WZ4002. Furthermore, GFP-based competition cell proliferation assays reveal that PC9 cells ectopically expressing EGFR mutant become more rapidly resistant to erlotinib than parental PC9 cells through the acquisition of the T790M mutation. Taken together, we believe that our findings expand upon the previous notion of evolutionary paths of T790M development, providing an important clue to designing a therapeutic strategy to overcome drug resistance.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Removal of priority and emerging pollutants from aqueous media by adsorption onto synthetic organo-funtionalized high-charge swelling micas

Highlights: • Adsorption occurs in the interlayer space (C{sub 18}-Mica-4: 49.9 Å). • Pollutants remained sorbed into C{sub 18}-Mica-4 at least 7 days after treatment. • No sample pH adjustment neither NaCl addition is required. • Removal rates from 70% to 100% for most of the 18 pollutants in 24 h. • Applicability to wastewater, surface and tap water samples demonstrated. In this work, the removal of different types of emerging pollutants (four perfluoroalkyl compounds, two preservatives, three surfactants and nine pharmaceutical compounds) from aqueous solution by adsorption onto two novel synthetic clays, a high-charge swelling mica (Na-Mica-4) and an organo-functionalized mica (C{sub 18}-Mica−4), was evaluated. Na-Mica-4 and C{sub 18}-Mica− 4 were prepared and characterized by X-Ray diffraction, Zeta potential, specific surface area, thermogravimetric analysis and transmission electron microscopy, before and after adsorption experiments. The influence of the aqueous sample pH, salt addition and extraction time in the removal were evaluated. The results showed the high adsorption affinity of C{sub 18}-Mica-4 for most of the emerging pollutants analysed after a removal time of 24 h (14 out of 18 pollutants were effectively removed [70–100%]). A high correlation was observed between the log K{sub ow} of the selected emerging pollutants and the adsorption onto C{sub 18}-Mica-4. The results also indicate that adsorption occurs in the interlayer space. While the removal rates with Na-Mica-4 were in the range 8–97% after seven days, some of the compounds, perfluorobutanoic acid and most of pharmaceutically active compounds, were not adsorbed onto the high-charge mica. C{sub 18}-Mica− 4 was effectively used for the removal of contaminants from four types of water samples.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Agnostic capture of pathogens for the detection and diagnostics of emerging threats

The continued emergence of pathogens, whether novel, re-emerging, or engineered, poses a persistent global biosecurity and public health challenge. Recent outbreaks, including COVID-19, Lassa fever, Marburg virus, mpox, and avian influenza, underscore the urgent need for robust systems that enable rapid surveillance, early diagnosis, and timely countermeasures before widespread human transmission occurs. In this article, we focus on early detection technologies and systematically evaluate current diagnostic and sensing modalities. We highlight sequencing and spectroscopy as two complementary approaches capable of providing broad, agnostic detection and rich biological insight. Our analysis emphasizes that scientific innovation alone is insufficient: effective preparedness also requires improved data curation, integration, and sharing to build AI-ready resources that accelerate future responses. We argue for coordinated advances in both technological capabilities and supporting infrastructure to enable the rapid identification and characterization of emerging pathogens and to fully leverage modern science against evolving infectious threats.

Environmental health↗
DOE OSTI2019

Emerging Manufacturing Technologies for Fuel Cells and Electrolyzers

Fuel cells have emerged as viable solutions in areas such as stationary and backup power systems, material handling equipment (MHE), and fuel cell electric vehicles (FCEV). Persistent challenges for fuel cells and electrolyzers include high initial cost and the availability of hydrogen infrastructure to support FCEV and MHE fleets. Cost of fuel cells are still high compared to other power generation systems such as diesel and natural gas generators. This, however, can be linked to two facts: first is low production volumes generally and second is emerging manufacturing technologies currently in R&D that need to be scaled up to factory production volumes. This study investigates current manufacturing processes used in production of fuel cells (e.g., spray coating and manual assembly) and emerging manufacturing technologies (e.g., roll-to-roll catalyst coating) to investigate key cost drivers and potential cost reductions in manufacturing of fuel cells and electrolyzers. In particular, we focus on how cost reductions for advance manufacturing technologies may be more significant at scale than existing technologies.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2024

Emergent Properties from Three-Dimensional Assemblies of (Nano)particles in Confined Spaces

The assembly of (nano)particles into compact hierarchical structures yields emergent properties not found in the individual constituents. The formation of these structures relies on a profound knowledge of the nanoscale interactions between (nano)particles, which are often designed by researchers aided by computational studies. These interactions have an effect when the (nano)particles are brought into close proximity, yet relying only on diffusion to reach these closer distances may be inefficient. Recently, physical confinement has emerged as an efficient methodology to increase the volume fraction of (nano)particles, rapidly accelerating the time scale of assembly. Specifically, the high surface area of droplets of one immiscible fluid into another facilitates the controlled removal of the dispersed phase, resulting in spherical, often ordered, (nano)particle assemblies. In this review, we discuss the design strategies, computational approaches, and assembly methods for (nano)particles in confined spaces and the emergent properties therein, such as trigger-directed assembly, lasing behavior, and structural photonic color. Finally, we provide a brief outlook on the current challenges, both experimental and computational, and farther afield application possibilities.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Emergent Nanostructure and Ion Transport in Polyzwitterion/Polyanion Blends

Solid polymer electrolytes (SPEs) hold great promise for the advancement of next-generation energy storage devices. However, the ion transport mechanism in SPEs remains poorly understood. In this study, we investigate blends of poly(1-(3-sulfonatopropyl)-2-vinylpyridinium) (P2VPPS) and poly(lithium (trifluoromethane)sulfonimide methacrylate) (P(MTFSI)Li) of varying molar ratios to develop a mechanistic understanding of ionic conductivity in a miscible polyzwitterion/polyanion system. Polyanions can act as single-ion conductors, but conductivity is often prohibitively low due to the decreased segmental mobility and ion aggregation. Here, it is hypothesized that the introduction of a polyzwitterion would competitively interact with the polyanion charge groups to realize improvements in the conductivity. Attractive interactions between the polyanions and polyzwitterions are confirmed by the blend’s increased glass transition temperature using the Gordon–Taylor equation. Notably, an ordered local nanostructure (∼24 Å) emerged in the P2VPPS/P(MTFSI)Li system at certain compositions, as characterized by small-angle X-ray and neutron scattering (SAXS/SANS). Concurrent with the emergence of this structure, broadband dielectric spectroscopy confirmed improvements in ionic conductivity. The highest conductivity is observed at a specific blend ratio P2VPPS:P(MTFSI)Li = 0.2:1 in the glassy state and 0.3:1 in the rubbery state, corresponding to the lowest effective activation energy (E*). Coarse-grained molecular dynamics simulations further emphasize the role of complexation between polyzwitterion and polyanion chains, correlating with the emergence of a new peak in SAXS and SANS for the blends. This work provides a fresh perspective on the role of local structural design in developing SPEs and offers insights into the morphological effects on ionic conductivity.

chemical structure↗
DOE OSTI2025

Skyrmion-like Spin Textures Emerging in the Material Derived from Structural Frustration

Magnetic materials with complex spin textures present both fundamental and practical appeal. The complex patterns of magnetic moments emerging on underlying crystal lattices hold potential for robust information storage and processing, including the promise of topological quantum computing. The scope of materials that host such patterns, however, remains rather limited. Here, in this study, we report a discovery of a complex spin texture in a noncentrosymmetric material that emerges from the structural frustration at the boundary between centrosymmetric parent structures MnCoGe (the hexagonal Ni 2 In or the orthorhombic TiNiSi structure type) and MnCoAs (the TiNiSi structure type). Our findings demonstrate that such structural frustration provides a powerful handle for identifying compositional spaces where complex magnetic behavior and associated nontrivial magnetic structures are likely to emerge. Thus, the new phase MnCoGe 1/3 As 2/3 exhibits a modulated cycloidal antiferromagnetic arrangement of electron spins on a noncentrosymmetric lattice (of the hexagonal ZrNiAl type) that materializes in the space between centrosymmetric collinear ferromagnets. This work provides a pathway for discovering novel materials with exotic spin textures for next-generation spintronics and quantum technologies.

Wang, YiXu [Florida State University, Tallahassee,↗
DOE OSTI2016

Thermodynamics of emergent magnetic charge screening in artificial spin ice

Electric charge screening is a fundamental principle governing the behaviour in a variety of systems in nature. Through reconfiguration of the local environment, the Coulomb attraction between electric charges is decreased, leading, for example, to the creation of polaron states in solids or hydration shells around proteins in water. Here, we directly visualize the real-time creation and decay of screened magnetic charge configurations in a two-dimensional artificial spin ice system, the dipolar dice lattice. By comparing the temperature dependent occurrence of screened and unscreened emergent magnetic charge defects, we determine that screened magnetic charges are indeed a result of local energy reduction and appear as a transient minimum energy state before the system relaxes towards the predicted ground state. These results highlight the important role of emergent magnetic charges in artificial spin ice, giving rise to screened charge excitations and the emergence of exotic low-temperature configurations.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Emergent long-range magnetic order in ultrathin (111)-oriented LaNiO3 films

Abstract The emergence of ferromagnetism in materials where the bulk phase does not show any magnetic order demonstrates that atomically precise films can stabilize distinct ground states and expands the phase space for the discovery of materials. Here, the emergence of long-range magnetic order is reported in ultrathin (111) LaNiO 3 (LNO) films, where bulk LNO is paramagnetic, and the origins of this phase are explained. Transport and structural studies of LNO(111) films indicate that NiO 6 octahedral distortions stabilize a magnetic insulating phase at the film/substrate interface and result in a thickness-dependent metal–insulator transition at t = 8 unit cells. Away from this interface, distortions relax and bulk-like conduction is regained. Synchrotron x-ray diffraction and dynamical x-ray diffraction simulations confirm a corresponding out-of-plane unit-cell expansion at the interface of all films. X-ray absorption spectroscopy reveals that distortion stabilizes an increased concentration of Ni 2+ ions. Evidence of long-range magnetic order is found in anomalous Hall effect and magnetoresistance measurements, likely due to ferromagnetic superexchange interactions among Ni 2+ –Ni 3+ ions. Together, these results indicate that long-range magnetic ordering and metallicity in LNO(111) films emerges from a balance among the spin, charge, lattice, and orbital degrees of freedom.

36 MATERIALS SCIENCE↗