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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 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

3D-printed sheet jet for stable megahertz liquid sample delivery at X-ray free-electron lasers

X-ray free-electron lasers (XFELs) can probe chemical and biological reactions as they unfold with unprecedented spatial and temporal resolution. A principal challenge in this pursuit involves the delivery of samples to the X-ray interaction point in such a way that produces data of the highest possible quality and with maximal efficiency. This is hampered by intrinsic constraints posed by the light source and operation within a beamline environment. For liquid samples, the solution typically involves some form of high-speed liquid jet, capable of keeping up with the rate of X-ray pulses. However, conventional jets are not ideal because of radiation-induced explosions of the jet, as well as their cylindrical geometry combined with the X-ray pointing instability of many beamlines which causes the interaction volume to differ for every pulse. This complicates data analysis and contributes to measurement errors. An alternative geometry is a liquid sheet jet which, with its constant thickness over large areas, eliminates the problems related to X-ray pointing. Since liquid sheets can be made very thin, the radiation-induced explosion is reduced, boosting their stability. These are especially attractive for experiments which benefit from small interaction volumes such as fluctuation X-ray scattering and several types of spectroscopy. Although their use has increased for soft X-ray applications in recent years, there has not yet been wide-scale adoption at XFELs. Here, gas-accelerated liquid sheet jet sample injection is demonstrated at the European XFEL SPB/SFX nano focus beamline. Its performance relative to a conventional liquid jet is evaluated and superior performance across several key factors has been found. This includes a thickness profile ranging from hundreds of nanometres to 60 nm, a fourfold increase in background stability and favorable radiation-induced explosion dynamics at high repetition rates up to 1.13 MHz. Its minute thickness also suggests that ultrafast single-particle solution scattering is a possibility.

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

Investigating the Combustion Performance of Dual Fuel Combustion with Diesel and Port Injected Hydrogen in a Large Bore Locomotive Engine

The heavy-duty transportation sector has primarily relied on conventional diesel combustion engines given their reliability and high thermal efficiency relative to spark ignition engines, but increased focus on reducing greenhouse gas emissions has led to investigation into alternative fuels. Gaseous hydrogen fuel has garnered a great deal of recent interest in the engine community given it has zero carbon, but hydrogen is not available at the scale and cost that petroleum fuels are currently available, and this is a barrier to adoption for industries that are looking to decarbonize their operations. Because of the fuel flexibility provided, dual fuel technology offers a pathway for some industries to adopt hydrogen as a fuel source while maintaining sufficient flexibility in times and locations where the new fuel is not yet available. This computational study investigates dual fuel combustion in a large bore locomotive engine architecture using direct injected diesel and port injected gaseous hydrogen fuel. With an optimal port fuel injection configuration from previous work, simulations of varying substitution ratio, compression ratio, manifold air temperature, diesel injection timing, and diesel injection pressure were performed to understand their effect on combustion performance. Results indicated that both increased substitution ratio and higher intake air temperature accelerates hydrogen flame propagation and can result in high peak cylinder pressures. Additionally, diesel injection timing and injection pressure were demonstrated as effective methods for controlling dual fuel combustion heat release rates.

ODonnell, Patrick Christopher↗
DOE OSTI2025

Cyanobacterial circadian regulation enhances bioproduction under subjective nighttime through rewiring of carbon partitioning dynamics, redox balance orchestration, and cell cycle modulation

Abstract Background The industrial feasibility of photosynthetic bioproduction using cyanobacterial platforms remains challenging due to insufficient yields, particularly due to competition between product formation and cellular carbon demands across different temporal phases of growth. This study investigates how circadian clock regulation impacts carbon partitioning between storage, growth, and product synthesis in Synechococcus elongatus PCC 7942, and provides insights that suggest potential strategies for enhanced bioproduction. Results After entrainment to light-dark cycles, PCC 7942 cultures transitioned to constant light revealed distinct temporal patterns in sucrose production, exhibiting three-fold higher productivity during subjective night compared to subjective day despite moderate down-regulation of genes from the photosynthetic apparatus. This enhanced productivity coincided with reduced glycogen accumulation and halted cell division at subjective night time, suggesting temporal separation of competing processes. Transcriptome analysis revealed coordinated circadian clock-driven adjustment of the cell cycle and rewiring of energy and carbon metabolism, with over 300 genes showing differential expression across four time points. The subjective night was characterized by altered expression of cell division-related genes and reduced expression of genes involved in glycogen synthesis, while showing upregulation of glycogen degradation pathways, alternative electron flow components, the pentose phosphate pathway, and oxidative decarboxylation of pyruvate. These molecular changes created favorable conditions for product formation through enhanced availability of major sucrose precursors (glucose-1-phosphate and fructose-6-phosphate) and maintained redox balance through multiple mechanisms. Conclusions Our analysis of circadian regulatory rewiring of carbon metabolism and redox balancing suggests two potential approaches that could be developed for improving cyanobacterial bioproduction: leveraging natural circadian rhythms for optimizing cultivation conditions and timing of pathway induction, and engineering strains that mimic circadian-driven metabolic shifts through controlled carbon flux redistribution and redox rebalancing. While these strategies remain to be tested, they could theoretically improve the efficiency of photosynthetic bioproduction by enabling better temporal separation between cell growth, carbon storage accumulation, and product synthesis phases.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Safeguards Technology Development Program 3rd Quarter FY 2018 Report

LLNL will evaluate the performance of a stilbene-based scintillation detector array for IAEA neutron multiplicity counting (NMC) applications. This effort will combine newly developed modeling methodologies and recently acquired high-efficiency stilbene detector units to quantitatively compare the prototype system performance with the conventional He-3 counters and liquid scintillator alternatives.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2020

XXVIIth International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2019) (Final Report)

Supersymmetry (SUSY) is one of most elegant extensions of the Standard Model (SM) and explains the puzzles of the SM by providing a candidate to explain the dark matter content of the universe, allowing scientists to understand the origin of the electroweak scale requiring the top mass to be around 170 GeV and leading to the unification of forces at a grand unified scale. Further the minimal supersymmetric standard model (MSSM) predicts the Higgs boson mass to be less than 135 GeV. The discovery of the Higgs Boson with mass around 125 GeV at the LHC has provided a major support to SUSY ideas. Searches for SUSY are ongoing at the Large Hadron Collider (LHC). Direct and indirect dark matter experiments are searching for a particle dark matter candidate which arises most naturally in SUSY models. Proton decay predicted by SUSY grand unified theories is being searched for at deep underground experiments. In addition, recent advances in neutrino and dark matter physics, observational astrophysics, precision cosmology and the promising new window into the cosmos opened by the direct detection of gravitational waves, have brought new ideas on the potential connections between new fundamental particles and our understanding of their impact on the early universe and its evolution. At present, the major questions include: Is SUSY still the best candidate for models beyond the SM? Do we have any well motivated alternative to SUSY? Have we exhausted all possibilities to search for new physics at high and low energy scales? XXVIIth International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2019), hosted by Texas A&M University – Corpus Christi during May 20-24, 2019, provided a unique venue to discus and understand the status of SUSY, connection between particle physics and cosmology, supersymmetry and its alternative, Higgs sector, neutrino sector, flavor sector, dark matter, electroweak phase transition, astroparticle physics, gravitational waves and string theory. Discussion of results from the LHC, recent neutrino experiments and observations, direct and indirect dark matter detection experiments, detection of gravitational waves, data from particle colliders, as well as measurements of the CMB and Large Scale Structure were an integral part of SUSY 2019. To ensure the younger participants will benefit from the conference the most, the conference was preceded by the 4 day long pre-SUSY summer school for graduate students and postdocs. The invited speakers were leading scientists in the fields of SUSY interest. The school took place on Texas A&M University – Corpus Christi campus during the week prior the SUSY 2019 conference (May 15 – 18, 2019). Since its inception in 1993, SUSY has become one of the most important and widely attended international meetings in high energy physics, devoted to new ideas in fundamental particle physics. SUSY 2019 brought together approximately 250 scientists, theorists, phenomenologists, experimentalists and cosmologists, (including over 60 graduate students and 70 postdocs) representing 22 nations: Australia, Belgium, Canada, Chile, China, Colombia, France, Germany, India, Italy, Japan, Mexico, Peru, Portugal, Romania, South Korea, Spain, Sweden, Switzerland, Taiwan, United Kingdom and United States. SUSY 2019 provided a stimulating venue for the exchange of scientific ideas among experts in dark matter, neutrino physics, particle physics, astrophysics and cosmology. The following scientific topics were delivered during SUSY 2019 in form of 44 plenary talks and over 200 parallel talks: Unification of Forces; Electroweak, Top and Higgs Physics; Precision Calculations and MC tools; BSM in Flavor Physics; Neutrino Masses: Models and Phenomenology; Cosmology and Gravitational Waves; Dark Matter, Astroparticle Physics; Formal Field Theory and Strings; Alternatives to Supersymmetry; Quantum Information: Machine Learning/Big Data. 28 talks were given during the pre-SUSY program related to the following topics: Neutrino Physics; Big Data; Collider Physics & SUSY; String Phenomenology; Cosmology; Dark Matter; SUSY Models and Phenomenology

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Advanced Airfoil Cooling Schemes to Increase Efficiency in Gas Turbines for Combined Heat and Power Applications

This report describes a three-year interdisciplinary effort funded by the U.S. Department of Energy’s (DOE) Energy Efficiency and Renewable Energy/Advanced Manufacturing Office (EERE/AMO) to promote market penetration of combined heat and power (CHP) technologies. Prior studies have shown the technical potential for CHP in the United States is much larger than the current deployment of CHP systems. A large portion of the technical potential CHP market aligns with small (<20 MWe) gas turbines. CHP systems are an attractive alternative to reduce greenhouse gas (GHG) emissions. For example, CHP systems can reduce GHG emissions by 30–40% relative to a conventional boiler and power configuration. These GHG emission reductions are “avoided emissions” which means no CO 2 separation or sequestration is required. This report describes an effort to use additive manufacturing (AM) technologies and advanced airfoil cooling designs to increase the turbine inlet temperature by 100 °C for small gas turbines typically used in CHP systems. At the beginning of this effort, baseline performance data for small gas turbines was not available, and the potential benefits of cooling system improvements were not quantified in the available literature.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1967

Analytical technique permits comparison of reliability of alternate mechanical designs

Failure Rate Index analysis permits comparison of reliability of alternate mechanical designs. All failure modes for a mechanical component are identified, and computed on an index which relates the failure mode to failure of the component. The summation of all failure mode indexes relates the potential reliability of the component.

Henning, F. W.↗
NASA NTRS1968

Concepts for a theoretical and experimental study of lifting rotor random loads and vibrations, Phase 2

A comparison with NASA conducted simulator studies has shown that the approximate digital method for computing rotor blade flapping responses to random inputs, tentatively suggested in Phase I Report, gives with increasing rotor advance ratio the wrong trend. Consequently, three alternative methods of solution have been considered and are described: (1) an approximate method based on the functional relation between input and output double frequency spectra, (2) a numerical method based on the system responses to deterministic inputs and (3) a perturbation approach. Among these the perturbation method requires the least amount of computation and has been developed in two forms - the first form to obtain the response correlation function and the second for the time averaged spectra of flapping oscillations.

Hohenemser, K. H.↗
NASA NTRS1976

Reassessment of roles of oxygen and ultraviolet light in Precambrian evolution

It is argued that the transition to an oxidizing atmosphere preceded the origin of eukaryotic cells, which in turn must have preceded the origin of metazoa. Moreover, the number of methods by which organisms can protect themselves from harmful UV radiation is sufficiently large to suggest that solar UV, even when the atmosphere was anaerobic, was not such as to control the distribution and diversification of life. An alternative explanation for the late and sudden appearance of metazoa in lower Cambrian sediments is proposed, which is related to the mechanisms by which fully mature eukaryotic cells probably originated. There was probably a protracted evolution of modern genetic systems based on mitosis in cells which acquired organelles (e.g., plastids and mitochondria) by hereditary endosymbiosis. The origin of hard parts underlies the Cambrian explosion of metazoans.

Margulis, L.↗
NASA NTRS1978

Site dependent factors affecting the economic feasibility of solar powered absorption cooling

A procedure was developed to evaluate the cost effectiveness of combining an absorption cycle chiller with a solar energy system. A basic assumption of the procedure is that a solar energy system exists for meeting the heating load of the building, and that the building must be cooled. The decision to be made is to either cool the building with a conventional vapor compression cycle chiller or to use the existing solar energy system to provide a heat input to the absorption chiller. Two methods of meeting the cooling load not supplied by solar energy were considered. In the first method, heat is supplied to the absorption chiller by a boiler using fossil fuel. In the second method, the load not met by solar energy is net by a conventional vapor compression chiller. In addition, the procedure can consider waste heat as another form of auxiliary energy. Commercial applications of solar cooling with an absorption chiller were found to be more cost effective than the residential applications. In general, it was found that the larger the chiller, the more economically feasible it would be. Also, it was found that a conventional vapor compression chiller is a viable alternative for the auxiliary cooling source, especially for the larger chillers. The results of the analysis gives a relative rating of the sites considered as to their economic feasibility of solar cooling.

Bartlett, J. C.↗
NASA NTRS1980

Quartz ball valve

A ball valve particularly suited for use in the handling of highly corrosive fluids is described. It is characterized by a valve housing formed of communicating segments of quartz tubing, a pair of communicating sockets disposed in coaxial alignment with selected segments of tubing for establishing a pair of inlet ports communicating with a common outlet port, a ball formed of quartz material supported for displacement between the sockets and configured to be received alternately thereby, and a valve actuator including a rod attached to the ball for selectively displacing the ball relative to each of the sockets for controlling fluid flow through the inlet ports.

Goetz, C.↗
NASA NTRS1986

Linearly polarized magnetic fluctuations at comet Giacobini-Zinner

The fully electromagnetic linear Vlasov dispersion equation for instabilities in a homogeneous, magnetized plasma is solved. Parameters appropriate to conditions observed during the ICE encounter with comet Giacobini-Zinner are used to study the polarization of electromagnetic instabilities driven by the relative streaming of two ion components. If the ion/ion relative drift is near the Alfven speed, the associated long-wavelength modes may be approximately linearly polarized at relatively small angles of propagation with respect to the magnetic field. The relatively inhomogeneous plasma background of the comet may impose such oblique propagation, so that this result provides an alternate explanation to the observations of linearly polarized waves near the comet.

Gary, S. Peter↗
NASA NTRS1989

The Allegheny Observatory search for planetary systems

The accomplishments of the observatory's search for planetary systems are summarized. Among these were the construction, implementation, and regular use of the Multichannel Astrometric Photometer (MAP), and the design, fabrication and use of the second largest refractor objective built since 1950. The MAP parallax and planetary observing programs are described. Various developments concerning alternate solid state photodetectors and telescope instrumentation are summarized. The extreme accuracy of the system is described in relation to a study of the position and velocity of the members of the open cluster Upgren 1. The binary star system stringently tests the theory of stellar evolution since it is composed of an evolved giant F5 III and a subgiant F5 IV star. A study that attempts to measure the luminosities, surface temperatures, and masses of these stars is discussed.

Gatewood, George D.↗
NASA NTRS1989

The Solar Power Satellite (SPS): Progress so far

Major developments in key Solar Power Satellite (SPS)-related technologies are outlined and the significance of these developments are evaluated considering the SPS, both as an alternate energy option for use on Earth and as a potential stimulus for space infrastructure developments and expansion of the use of extraterrestrial resources.

Glaser, Peter E.↗
NASA NTRS1990

Test of the gravitational redshift effect at Saturn

The results of a test of the gravitational redshift effect at Saturn are reported. Measurements of the redshift were obtained with the Voyager 1 spacecraft during its encounter with Saturn in 1980. Because the spacecraft was equipped with an ultrastable crystal oscillator (USO), it is possible to test the redshift effect at an interesting level of accuracy. Assuming that radiation in the Saturn magnetosphere has had a negligible effect on the USO, the prediction of general relativity to an accuracy of 1 percent is verified. This limit could be of interest for constraining possible alternative theories of gravity.

Krisher, Timothy P.↗
NASA NTRS1990

QUEST/Ada (Query Utility Environment for Software Testing of Ada): The development of a prgram analysis environment for Ada, task 1, phase 2

The results of research and development efforts are described for Task one, Phase two of a general project entitled The Development of a Program Analysis Environment for Ada. The scope of this task includes the design and development of a prototype system for testing Ada software modules at the unit level. The system is called Query Utility Environment for Software Testing of Ada (QUEST/Ada). The prototype for condition coverage provides a platform that implements expert system interaction with program testing. The expert system can modify data in the instrument source code in order to achieve coverage goals. Given this initial prototype, it is possible to evaluate the rule base in order to develop improved rules for test case generation. The goals of Phase two are the following: (1) to continue to develop and improve the current user interface to support the other goals of this research effort (i.e., those related to improved testing efficiency and increased code reliable); (2) to develop and empirically evaluate a succession of alternative rule bases for the test case generator such that the expert system achieves coverage in a more efficient manner; and (3) to extend the concepts of the current test environment to address the issues of Ada concurrency.

Brown, David B.↗
NASA NTRS1991

The structure and evolution of rich star clusters in the Large Magellanic Cloud

The present evaluation of surface brightness profiles and color-magnitude diagrams for 18 rich star clusters in the LMC, whose ages range from 10 million to 1 billion years, notes that while the profiles of the older clusters are representable by models with King-like cores, those of many younger clusters resist such modeling in virtue of bumps, sharp 'shoulders', and central dips. If the clusters have undergone violent relaxation, then the small cores of the youngest ones may be indicative of formation from relatively 'cool' initial conditions. The sharp shoulders would then point point toward 'warmer' initial conditions, although they are alternatively explainable as signatures of merging subcondensations.

Elson, Rebecca A. W.↗
NASA NTRS1992

Stronger Source As Reference For Weaker Source In VLBI

Observation of weak astronomical radio source by very-long-baseline interferometry (VLBI) enhanced by using relatively strong astronomical radio source within small angular distance from weak source. Strong source and weak source observed alternately during measurement session. Direct detection of strong source provides reference delays and rates of change of delays used to integrate radio visibilities of weak source. Integrated visibilities added coherently over entire measurement session, using observed phases of strong source as references.

Lestrade, Jean-Francois↗