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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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Hybrid energy systems (HESs) using small modular reactors (SMRs)

Large-scale nuclear reactors are traditionally operated for a singular purpose: steady-state production of dispatchable baseload electricity that is distributed broadly on the electric grid. While this implementation is key to a sustainable, reliable energy grid, small modular reactors (SMRs) offer new opportunities for increased use of clean nuclear energy for both electric and thermal ap plications in more locations – while still accommodating the desire to support renewable production sources.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Manually operated small envelope scanner system

A scanner system and method for acquisition of position-based ultrasonic inspection data are described. The scanner system includes an inspection probe and a first non-contact linear encoder having a first sensor and a first scale to track inspection probe position. The first sensor is positioned to maintain a continuous non-contact interface between the first sensor and the first scale and to maintain a continuous alignment of the first sensor with the inspection probe. The scanner system may be used to acquire two-dimensional inspection probe position data by including a second non-contact linear encoder having a second sensor and a second scale, the second sensor positioned to maintain a continuous non-contact interface between the second sensor and the second scale and to maintain a continuous alignment of the second sensor with the first sensor.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Small Unmanned Aerial Systems (sUAS) on the NNSS White Paper

The Nevada National Security Site (NNSS) prides itself on being the premier outdoor, indoor, and underground national laboratory. It is the preferred location for experiments supporting the National Nuclear Security Administration’s nuclear weapons Stockpile Stewardship Programs, national defense programs, and national security research, development, and training programs, as well as vital programs of other federal agencies. Work at the NNSS supports the Stockpile Stewardship Program, Global and Homeland Security programs, and Environmental Management. The NNSS looks to incorporate safer work practices and continuous improvements. Unmanned Aerial Surveys (UAS) have already been implemented in areas off the NNSS for multiple uses. Using these best practices with systems catered to the NNSS would allow integration of new technology and would allow work at the NNSS to maintain the high level of quality already exhibited. The Management and Operating Contractor (M&O) has shown experience in multiple UAS platforms. Through the coordination and experience developed through these projects, the M&O can further improve the quality and cost effectiveness of services currently rendered and offer new services not currently available today. Several NNSS departments that could implement UAS technology are Emergency Response, Facility Management, Environmental Management, and Training. These departments would be able to improve their capabilities and expand personnel effectiveness with the inclusion of UASs and the information they provide.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2019

Characteristics of refrigerant leaks from small HVAC&R systems

Reduced use of high global warming potential (GWP) hydrofluorocarbon (HFC) refrigerants is desired. However, many lower-GWP alternatives are flammable, some of higher flammability levels, or A3, and others of lower flammability (A2 or A2L).Safety standards for A2 and A3 flammable refrigerants, including the International Electrotechnical Commission (IEC) standard IEC 60335-2-40 calculate maximum flammable refrigerant charge limits using a fixed 4-minute leak time based on the time to leak 150 g of CO2 through a capillary tube.Actual refrigerant leak times depend on the equipment type, leak location, leak orifice diameter and equipment operation condition (on or off).Five systems were installed in test chambers with leak quantities and rates measured by tracking total system weight during the leak event. Among the major results were that almost all of the system charge was shown to escape the units, >80% within the first 10 minutes.

Patel, Viral↗
DOE OSTI2017

Experimentation of Synchronous and Variable Speed Small Scale Hydropower Systems

Hydropower is the one of the oldest renewable energy technologies and is wrongly thought of today as having little room to grow. The opportunity for new hydropower capacity is immense through both technology advancement and run-of-river new stream reach projects. Despite the age of hydropower, a divide in opinion is forming regarding how we should proceed with generating power from smaller undisturbed rivers and canals. Hydropower generation techniques have been primarily fixed speed since its inception in the late 19th century, but it seems as though variable speed generation could hold the key to more efficiently utilizing new stream reach resources. This research aims to provide a cost benefit analysis of fixed speed vs. variable speed hydropower generation topologies, and distinguish the performance advantages that variable speed generation could hold in other aspects of hydropower. Simulation results are validated with hardware.

13 HYDRO ENERGY↗
NASA NTRSDate not supplied

NASA Small Spacecraft and Distributed Systems Program - Recent and Upcoming Technology Demonstrations and Development Efforts

NASA’s Small Spacecraft & Distributed Systems (SSDS) program strengthens U.S. ability to conduct unique missions by rapidly developing and demonstrating capabilities for SmallSat exploration, science, and commercial space. In collaboration with NASA Centers, other government agencies, commercial industry, and academia, SSDS advances next generation SmallSat technologies like power, processing, propulsion, communications, autonomous navigation, architectures (swarms), and applications (AI/ML/Edge Computing)—to extend missions beyond LEO into cislunar and planetary space. Various investment mechanisms exist for SSDS to select and fund projects that will ultimately advance NASA’s Moon to Mars Architecture. Presented here are the latest achievements and findings from recently completed SSDS projects, along with updates from ongoing efforts and planned future work. Successful missions like Starling and CAPSTONE continue to demonstrate their capability after several years on-orbit. Advancements in next generation swarm configurations are being implemented by Starling for space traffic monitoring and management applications. Findings from recent SSDS flight projects are discussed: DiskSat, a unique SmallSat platform alternative to canisterized nanosatellites, launched December 2025 and is gathering data; the PTD series of missions concluded in December 2025. Current SSDS efforts are focused on addressing NASA Shortfalls relating to rendezvous and proximity operations, neuromorphic computing, and space situational awareness.

Roger C Hunter↗
DOE OSTI2016

Calculating potential energy curves with fixed-node diffusion Monte Carlo: CO and N 2

This study reports on the prospect for the routine use of Quantum Monte Carlo (QMC) for the electronic structure problem, applying fixed-node Diffusion Monte Carlo (DMC) to generate highly accurate Born-Oppenheimer potential energy curves (PECs) for small molecular systems. The singlet ground electronic states of CO and N 2 were used as test cases. The PECs obtained by DMC employing multiconfigurational trial wavefunctions were compared with those obtained by conventional high-accuracy electronic structure methods such as multireference configuration interaction and/or the best available empirical spectroscopic curves. The goal was to test whether a straightforward procedure using available QMC codes could be applied robustly and reliably. Results obtained with DMC codes were found to be in close agreement with the benchmark PECs, and the n 3 scaling with the number of electrons (compared with n 7 or worse for conventional high-accuracy quantum chemistry) could be advantageous depending on the system size. Due to a large pre-factor in the scaling, for the small systems tested here, it is currently still much more computationally intensive to compute PECs with QMC. Nevertheless, QMC algorithms are particularly well-suited to large-scale parallelization and are therefore likely to become more relevant for future massively parallel hardware architectures.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Novel collective phenomena in high-energy proton–proton and proton–nucleus collisions

The observation of long-range rapidity correlations among particles in high-multiplicity p–p and p–Pb collisions created new opportunities for investigating novel high-density QCD phenomena in small colliding systems. We also review experimental results related to the study of collective phenomena in small systems at RHIC and the LHC along with the related developments in theory and phenomenology. Finally, perspectives on possible future directions for research are discussed with the aim of exploring emergent QCD phenomena.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2024

Melting and freezing of a skyrmion lattice

We report comprehensive Monte–Carlo studies of the melting of skyrmion lattices (SkL) in systems of small, medium, and large sizes with the number of skyrmions ranging from 10 3 to over 10 5 . Large systems exhibit hysteresis similar to that observed in real experiments on the melting of SkLs. For sufficiently small systems which achieve thermal equilibrium, a fully reversible sharp solid–liquid transition on temperature with no intermediate hexatic phase is observed. A similar behavior is found on changing the magnetic field that provides the control of pressure in the SkL. Here, we find that on heating the melting transition occurs via a formation of grains with different orientations of hexagonal axes. On cooling, the fluctuating grains coalesce into larger clusters until a uniform orientation of hexagonal axes is slowly established. The observed scenario is caused by collective effects involving defects and is more complex than a simple picture of a transition driven by the unbinding and annihilation of dislocation and disclination pairs.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗