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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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The present investigation relates to a box-type fuselage with sides consisting of thin smooth sheet metal, stiffened by longitudinal members riveted to the flanged channel-section bulkheads or transverse frames and to the semicircular corrugated corner stiffenings. The results obtained in this particular case can be applied to a great number of similar structures.
The aim of this work is to gain physical insight into the role played by a concentrated central mass in affecting the shape of elliptical galaxies, by examining its effect on the stability of box orbits which are the backbone of triaxial elliptical galaxies. Ample observational evidence is now available for the existence of a central mass concentration or central cusps in galaxies. The central mass is expected to cause orbital stochasticity and chaotic mixing of orbits, which could have ramifications on galactic evolution. We investigate here the interplay between potential cuspiness and eccentricity on the stability of axial orbits in a scale-free potential in a simple, preliminary attempt to characterize this effect.
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Abstract Objective Northern Pike Esox lucius recently invaded Box Canyon Reservoir, Washington, expanding to over 10,000 individuals by 2011. To limit further impacts, a significant reduction in population abundance was required. Project objectives were to reduce relative abundance (catch per unit effort [CPUE]) to less than 1.7 Northern Pike/net (87% reduction) in the core area and to less than 0.5 Northern Pike/net in the northern reservoir section within 3 years and then maintain those abundance targets thereafter. Methods Using gill nets, we conducted intensive annual (2012–2018) suppression each spring, focusing on spawning aggregations in shallow (<2-m), flooded habitats. To evaluate CPUE, a standardized spring pike index netting (SPIN) survey was conducted annually in May and compared to suppression netting CPUE. Result In total, 17,464 Northern Pike were removed in 4868 net sets, with 92.9% captured in the first 3 years, limiting future recruitment. Mean SPIN CPUE in the core area declined from a presuppression (2011) high of 13.2 Northern Pike/net to less than 1.0 Northern Pike/net by 2014. Effort was reduced by up to 80% as the project transitioned from the initial suppression phase (2012–2014) to a control phase (2015–2018), which explored the minimum effort required to maintain abundance targets. A significant rebound in CPUE occurred from 2017 to 2018, indicating that over 267 net sets annually may be required for long-term control. Although the mean CPUE (±95% confidence interval) increased slightly in 2018 (0.6 ± 0.5 Northern Pike/net), the target abundance in the core area was achieved annually from 2013 to 2018. Changes in suppression CPUE reflected those observed in SPIN surveys, further validating the survey and corroborating abundance trends. Conclusion Results demonstrate that the suppression of Northern Pike in large, complex waters is feasible but requires a substantial long-term commitment. We expect the suppression of this invasive species to become standard practice outside of its native range. The methodology and equipment described here could be applied directly or modified by others to suppress Northern Pike.
The mechanisms governing pressure-induced amorphization and its reversibility in halide perovskites are not yet fully understood, particularly the contribution of local disorder. We performed high-pressure synchrotron total X-ray scattering and reverse Monte Carlo (RMC) big-box modeling using CsPbBr 3 as a model system to investigate short-range structural evolution in both the ordered and partially amorphous phases. While diffraction data indicate that long-range order persists up to 2 GPa, pair distribution function (PDF) analysis reveals significant local distortions, including PbBr 6 octahedral tilting and Cs displacement, which influence the bandgap through a complex interplay between bond compression and angular tilting. Beyond 2 GPa, CsPbBr 3 undergoes partial amorphization, with significant disordering of Cs and Br, while the Pb sublattice remains preserved, allowing for structural recovery upon decompression. Our work, accounting for both short- and long-range structural evolution through RMC modeling, successfully captures how disorder shapes the structural response of halide perovskites under pressure.
Thermal batteries are crucial for supplying power to high-consequence engineering applications such as rockets. Computational simulations have been developed to predict thermal battery behavior, but these simulations often suffer from modeling errors, including model form uncertainty. Addressing this uncertainty can be achieved by quantifying either the model discrepancy in the output or the model form error (MFE) in the governing equation. MFE is particularly valuable as it can be better extrapolated beyond observed outputs, which is essential for predictions involving changes in external system loading, system configuration and geometry, or output quantities. This paper employs a state estimation approach to estimate MFE using experimental data and then utilizes machine learning (ML) to model its relationship with state variables. A nonintrusive technique is used to estimate MFE in a black-box thermal battery heat transfer simulation. The trained machine learning model for MFE is then applied to correct simulation predictions under extrapolated initial conditions and battery configurations. In conclusion, the methodology's performance is evaluated using additional experimental data, demonstrating its effectiveness in improving prediction accuracy.
Abstract Background In response to environmental stresses, chloroplasts generate reactive oxygen species, including singlet oxygen ( 1 O 2 ), an excited state of oxygen that regulates chloroplast-to-nucleus (retrograde) signaling, chloroplast turnover, and programmed cell death (PCD). Yet, the central signaling mechanisms and downstream responses remain poorly understood. TheArabidopsis thaliana plastid ferrochelatase two(fc2) mutant conditionally accumulates 1 O 2 , and Plant U-Box 4 (PUB4), a cytoplasmic E3 ubiquitin ligase, is involved in propagating 1 O 2 signals for chloroplast turnover and cellular degradation. Thus, thefc2andfc2 pub4mutants are useful genetic tools to elucidate these signaling pathways. Previous studies have focused on the role of 1 O 2 in promoting cellular degradation infc2mutants, but its impact on retrograde signaling from mature chloroplasts (the major site of 1 O 2 production) is poorly understood. Results To gain mechanistic insights into 1 O 2 signaling pathways, we compared transcriptomes of adult wt,fc2, andfc2 pub4plants. The accumulation of 1 O 2 infc2plants broadly repressed genes involved in chloroplast function and photosynthesis, while inducing genes and transcription factors involved in abiotic and biotic stress, the biosynthesis of jasmonic acid (JA) and salicylic acid (SA), microautophagy, and senescence. Elevated JA and SA levels were observed in 1 O 2 -stressedfc2plants.pub4reversed most of this 1 O 2 -induced gene expression and reduced the JA content infc2plants. Thepub4mutation also blocked JA-induced senescence pathways in the dark. However, fc2 pub4 plantsmaintained constitutively elevated levels of SA even in the absence of bulk 1 O 2 accumulation. Conclusions Together, this work demonstrates that infc2plants, 1 O 2 leads to a robust retrograde signal that may protect cells by downregulating photosynthesis and ROS production while simultaneously mounting a stress response involving SA and JA. The induction of microautophagy and senescence pathways indicate that 1 O 2 -induced cellular degradation is a genetic response to this stress, and the bulk of this transcriptional response is modulated by the PUB4 protein. However, the effect ofpub4on hormone synthesis and signaling is complex and indicates that an intricate interplay of SA and JA are involved in promoting stress responses and programmed cell death during photo-oxidative damage.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.
This dataset contains telemetry data from the 220EV box truck as provided by the manufacturer, Dana. Data are recorded in a time series interval of 1 second. Recorded data contain odometer reading (kilometers), axle speed, state of charge of the battery, and cabin heater setting.