Search NASA⌕ Search

SEARCH · Search NASA

Results for “Love”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Intestinal single-cell atlas reveals novel lymphocytes in pigs with similarities to human cells

Lymphocytes can heavily influence intestinal health, but resolving intestinal lymphocyte function is challenging as the intestine contains a vastly heterogeneous mixture of cells. Pigs are an advantageous biomedical model, but deeper understanding of intestinal lymphocytes is warranted to improve model utility. Twenty-six cell types were identified in the porcine ileum by single-cell RNA sequencing and further compared with cells in human and murine ileum. Though general consensus of cell subsets across species was revealed, some porcine-specific lymphocyte subsets were identified. Differential tissue dissection and in situ analyses conferred spatial context, revealing similar locations of lymphocyte subsets in Peyer’s patches and epithelium in pig-to-human comparisons. Like humans, activated and effector lymphocytes were abundant in the ileum but not periphery of pigs, suggesting tissue-specific and/or activation-associated gene expression. Gene signatures for peripheral and ileal innate lymphoid cells newly discovered in pigs were defined and highlighted similarities to human innate lymphoid cells. Overall, we reveal novel lymphocyte subsets in pigs and highlight utility of pigs for intestinal research applications.

Life Sciences & Biomedicine - Other Topics↗
DOE OSTI2022

Photonic Luminescent Solar Concentrator Design for High Efficiency, Low Cost Multijunction Photovoltaics

Despite the extraordinary advances in solar cell efficiency in laboratory settings, the deployment of solar cells continues to be limited to low efficiency (<25%) silicon cells because of cost. In this work, we take advantage of the extraordinary optical properties afforded by nanophotonic structures to create a photonic luminescent solar concentrator for an InGaP-Si multijunction concentrator cell. Finite difference time domain (FDTD) simulations demonstrated a concentrator that could effectively capture, downconvert, and guide concentrated light to an InGaP subcell while still transmitting longer wavelengths to a Si subcell. We fabricated the photonic luminescent solar concentrator, which was comprised of CdSe/CdS quantum dots embedded within alternating layers of Si 3 N 4 and SiO 2 , and experimentally verified the optical performance, showing a 40% increase in light guiding and a significant reduction in reabsorption losses in the plane of the luminescent concentrator as compared to traditional designs. Finally, we utilized modified detailed balance calculations that accounted for cell and optical losses and showed >30% efficiencies are possible with this design, demonstrating the potential to meet the demands for high efficiency, inexpensive solar modules.

Eisler, Carissa N.↗
DOE OSTI2021

Light-Front Field Theory on Current Quantum Computers

We present a quantum algorithm for simulation of quantum field theory in the light-front formulation and demonstrate how existing quantum devices can be used to study the structure of bound states in relativistic nuclear physics. Specifically, we apply the Variational Quantum Eigensolver algorithm to find the ground state of the light-front Hamiltonian obtained within the Basis Light-Front Quantization (BLFQ) framework. The BLFQ formulation of quantum field theory allows one to readily import techniques developed for digital quantum simulation of quantum chemistry. This provides a method that can be scaled up to simulation of full, relativistic quantum field theories in the quantum advantage regime. As an illustration, we calculate the mass, mass radius, decay constant, electromagnetic form factor, and charge radius of the pion on the IBM Vigo chip. This is the first time that the light-front approach to quantum field theory has been used to enable simulation of a real physical system on a quantum computer.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Variational Quantum Chemistry Programs in JaqalPaq

We present example quantum chemistry programs written with JaqalPaq, a python meta-programming language used to code in Jaqal (Just Another Quantum Assembly Language). These JaqalPaq algorithms are intended to be run on the Quantum Scientific Computing Open User Testbed (QSCOUT) platform at Sandia National Laboratories. Our exemplars use the variational quantum eigensolver (VQE) quantum algorithm to compute the ground state energies of the H2, HeH+, and LiH molecules. Since the exemplars focus on how to program in JaqalPaq, the calculations of the second-quantized Hamiltonians are performed with the PySCF python package, and the mappings of the fermions to qubits are obtained from the OpenFermion python package. Using the emulator functionality of JaqalPaq, we emulate how these exemplars would be executed on an error-free QSCOUT platform and compare the emulated computation of the bond-dissociation curves for these molecules with their exact forms within the relevant basis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Urban Land Surface Temperature Downscaling in Chicago: Addressing Ethnic Inequality and Gentrification

In this study, we developed a XGBoost-based algorithm to downscale 2 km-resolution land surface temperature (LST) data from the GOES satellite to a finer 70 m resolution, using ancillary variables including NDVI, NDBI, and DEM. This method demonstrated a superior performance over the conventional TsHARP technique, achieving a reduced RMSE of 1.90 °C, compared to 2.51 °C with TsHARP. Our approach utilizes the geostationary GOES satellite data alongside high-resolution ECOSTRESS data, enabling hourly LST downscaling to 70 m—a significant advancement over previous methodologies that typically measure LST only once daily. Applying these high-resolution LST data, we examined the hottest days in Chicago and their correlation with ethnic inequality. Our analysis indicated that Hispanic/Latino communities endure the highest LSTs, with a maximum LST that is 1.5 °C higher in blocks predominantly inhabited by Hispanic/Latino residents compared to those predominantly occupied by White residents. This study highlights the intersection of urban development, ethnic inequality, and environmental inequities, emphasizing the need for targeted urban planning to mitigate these disparities. The enhanced spatial and temporal resolution of our LST data provides deeper insights into diurnal temperature variations, crucial for understanding and addressing the urban heat distribution and its impact on vulnerable communities.

Lee, Jangho (ORCID:0000000289421092)↗
DOE OSTI2022

A framework for ensemble modelling of climate change impacts on lakes worldwide: the ISIMIP Lake Sector

Abstract. Empirical evidence demonstrates that lakes and reservoirs are warming across the globe. Consequently, there is an increased need to project future changes in lake thermal structure and resulting changes in lake biogeochemistry in order to plan for the likely impacts. Previous studies of the impacts of climate change on lakes have often relied on a single model forced with limited scenario-driven projections of future climate for a relatively small number of lakes. As a result, our understanding of the effects of climate change on lakes is fragmentary, based on scattered studies using different data sources and modelling protocols, and mainly focused on individual lakes or lake regions. This has precluded identification of the main impacts of climate change on lakes at global and regional scales and has likely contributed to the lack of lake water quality considerations in policy-relevant documents, such as the Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC). Here, we describe a simulation protocol developed by the Lake Sector of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) for simulating climate change impacts on lakes using an ensemble of lake models and climate change scenarios for ISIMIP phases 2 and 3. The protocol prescribes lake simulations driven by climate forcing from gridded observations and different Earth system models under various representative greenhouse gas concentration pathways (RCPs), all consistently bias-corrected on a 0.5∘ × 0.5∘ global grid. In ISIMIP phase 2, 11 lake models were forced with these data to project the thermal structure of 62 well-studied lakes where data were available for calibration under historical conditions, and using uncalibrated models for 17 500 lakes defined for all global grid cells containing lakes. In ISIMIP phase 3, this approach was expanded to consider more lakes, more models, and more processes. The ISIMIP Lake Sector is the largest international effort to project future water temperature, thermal structure, and ice phenology of lakes at local and global scales and paves the way for future simulations of the impacts of climate change on water quality and biogeochemistry in lakes.

58 GEOSCIENCES↗
DOE OSTI2020

Electromagnetic print nozzle for direct-write additive manufacturing

A method and apparatus for additive manufacturing that includes a material guide for directing a supply of working material and a plurality of rollers for advancing the working material. An electromagnetic heater is provided to heat and deposit molten working material as a new supply of working material is forced through the material guide.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Production of Medium-Scale Metal Additive Geometry With Hybrid Manufacturing Technology

Oak Ridge National Lab’s (ORNL) Metal Big Area Additive Manufacturing (mBAAM) and Hybrid Manufacturing teams in the Manufacturing Demonstration Facility (MDF) was tasked with developing a part that exceeded 24 inches in length and 100lbs in weight on a laser hotwire welding system. The Mazak VC-500A/5X AM HWD hybrid 5-axis CNC laser hotwire system was leveraged to complete the task. The proposed geometry was manufactured with 410 stainless steel on AISI1018 steel substrate in just over 36 hours of build time. The proposed geometry was sliced and additively manufactured in three segments; the base, and two extrusions measuring 10 inches in length and 14 inches in length. Production of this component demonstrated hybrid capabilities requiring fixed 5-axis rotations to complete geometry that exceeded the defined build volume of the machine. Multiple repairs of the part were conducted in-situ leveraging the additive and subtractive capabilities of the Mazak hybrid system. Significant overbuilding challenges were encountered and manually addressed by leveraging subtractive capabilities of the hybrid system. Future processes are presented for development to reduce overheating of top layers. Final part measurements exceeded 107 lbs. in weight and 24.5 inches in length along the principal axis; the largest and heaviest part created by a hybrid system at the MDF.

Saleeby, Kyle↗
DOE OSTI2021

Foreword 1: The Medici Effect and the Importance of Women in Manufacturing

In 2004, Frans Johansson published “The Medici Effect” which emphasizes the need for diversity for innovation. His hypothesis is based on the Medici Dynasty in the 14th Century and their role in the birth of the Renaissance. The Medici’s financial support of painters, poets, scientists, architects… a variety of disciplines working closely together on diverse problems, led to an explosion of innovations. We still see this today in pockets of industries where architects work with entomologists on new designs of energy efficient building, roboticist study nature to understand locomotion and manipulation. One of my most rewarding programs was when I worked with a microbiologist to use bacteria to synthesize magnetic nanoparticles for ferrofluids. Diversity is the fuel for innovation. Our greatest source of fuel for diversity is gender.

Love, Lonnie↗
DOE OSTI2020

Dual Material System for Polymer Large Scale Additive Manufacturing

Big Area Additive Manufacturing (BAAM) technology allows for manufacturing of large-scale objects with a potential to reduce energy embedded in products, reduce or eliminate energy necessary for transportation of goods along with reducing the lead time and cost in some cases. Over the last few years, Oak Ridge National Laboratory (ORNL) has been focusing on large-scale printing of single material systems, typically un-reinforced or short fiber reinforced polymers, in order to address needs in stiffness-limited applications. This paper describes the development of a multi-material large-scale AM system through a collaboration with Cincinnati Inc. and Performance Feed Screw Inc. Modifications to the Big Area Additive Manufacturing (BAAM) system includes a new extruder design to accommodate a dual feed system, an expanded two-dryer system with a capacity of 273 kg/dryer, and a system that is capable of mixing pelletized materials up to 60Kg/hr. This article highlights the advantages and limitations of the multi-material system as well as potential applications.

Smith, Tyler↗
DOE OSTI2021

Polymer exhaust for eliminating extruder transients

An additive manufacturing method that includes an extruder providing a supply of working material and a nozzle connected with respect to the extruder, the nozzle directing the working material to a deposit surface. A diverter valve is positioned between the extruder and the nozzle to direct the working material to an exhaust port away from the deposit surface under certain conditions.

Chesser, Phillip C.↗
DOE OSTI2021

Method for printing low-density polymer structures

A method of forming a low-density three-dimensional article is provided. The method includes printing a low-density composition on a substrate to form at least one layer comprising the low-density composition. The low-density composition includes a (P) polymer component and (M) a microsphere component in a ratio by volume (P):(M). The method also includes selectively controlling a density of the low-density composition during printing to give the at least one layer on the substrate. Selectively controlling the density of the low-density composition includes varying the ratio (P):(M) during printing. The method further includes repeating the printing and selectively controlling the density of the low-density composition to form additional layer(s), thereby forming the low-density three-dimensional article. A low-density three-dimensional article prepared in accordance with the method is also provided.

Kunc, Vlastimil↗