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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Accuracies of Atmospheric Profiles Obtained from GPS Occultations

Radio occultation studies of the terrestrial atmosphere are possible through use of signals transmitted by satellites of the Global Positioning System (GPS) and received by one or more other satellites in low earth orbit (LEO). The perturbed phase of the occulted signal gives direct information on the refractivity profile in the region of occultation, from which vertical profiles of density, pressure, and temperature can be retrieved. Based on model simulations the capability of GPS to provide atmospheric profiles is assessed.

atmospheric↗
DOE OSTI2023

A Two-Step Time-Series Data Clustering Method for Building-Level Load Profile

Residential and commercial buildings have huge potential to contribute value to improve grid resilience by participating grid services. To reveal the significant value, it is critical to estimate the grid service capability from these buildings. Unlike the large-scale distributed energy resources such as wind and solar farms, those buildings need to participate grid services in aggregation, not by individual. Therefore, it is important to appropriately group buildings for aggregation. The load profiles in the same group will have similar characteristics at the same time step, so grid operators can send the grid service signal to the customer group with a higher chance to respond at that time step. In this paper, we develop a load profile clustering method to classify the building-level load profiles for grid service capability estimation and the results have proved the effectiveness of this method.

AMI↗
DOE OSTI2016

The microphysical contributions to and evolution of latent heating profiles in two MC3E MCSs

Abstract The shapes and magnitudes of latent heating profiles have been shown to be different within the convective and stratiform regions of mesoscale convective systems (MCSs). Properly representing these distinctions has significant implications for the atmospheric responses to latent heating on various scales. This study details (1) the microphysical process contributions to latent heating profiles within MCS convective, stratiform, and anvil regions and (2) the time evolution of these profiles throughout the MCS lifetime, using cloud‐resolving model simulations. Simulations of two MCS events that occurred during the Midlatitude Continental Convective Clouds Experiment (MC3E) are conducted. Several features of the simulated MCSs are compared to a suite of observations obtained during the MC3E field campaign, and it is concluded that the simulations reasonably reproduce the MCS events. The simulations show that condensation and deposition are the primary contributors to MCS latent warming, as compared to riming and nucleation processes. In terms of MCS latent cooling, sublimation, melting, and evaporation all play significant roles. It is evident that throughout the MCS lifecycle, convective regions demonstrate an approximately linear decrease in the magnitudes of latent heating rates, while latent heating within stratiform regions is associated with transitions between MCS flow regimes. Such information regarding the temporal evolution of latent heating within convective and stratiform MCS regions could be useful in developing parameterizations representing convective organization.

Marinescu, P. J.↗
DOE OSTI2021

Early Battery Performance Prediction for Mixed Use Charging Profiles Using Hierarchal Machine Learning

A key step limiting how fast batteries can be deployed is the time necessary to provide evaluation and validation of performance. Using data analysis approaches, such as machine learning, the validation process can be accelerated. However, questions on the validity of projecting models trained on limited data or simple cycling profiles, such as constant current cycling, to real-world scenarios with complex loads remains. Here, we present the ability to predict performance with less than 1.2% mean absolute percent error when trained on cells aged using complex electric vehicle discharge profiles, and either AC Level 2 charge or DC Fast charge profiles, using only the first 45 cycles, namely 5% of the total testing time. While error is low across the projections, this study also highlights that battery lifetime analysis using only cycling data may not extrapolate safely to certain real-world conditions due to the impact of calendar degradation.

25 ENERGY STORAGE↗
DOE OSTI2021

Qualitative and quantitative profiles of jejunal oligosaccharides and cecal short–chain fatty acids in broiler chickens receiving different dietary levels of fiber, protein and exogenous enzymes

Dietary supplemental carbohydrases are able to degrade non-starch polysaccharides and generate oligosaccharides in the gastrointestinal tract. This study was conducted to investigate the influence of dietary fiber and protein levels on growth performance, nutrient utilization, digesta oligosaccharides profile and cecal short-chain fatty acid (SCFA) profile in broilers receiving diets supplemented with xylanase or protease individually or in combination. Enzyme supplementation had no effect on growth performance. There was significant (P < 0.05) fiber × protein × xylanase interaction for ileal nitrogen digestibility and significant (P < 0.01) protein × xylanase × protease interaction for nitrogen-corrected apparent metabolizable energy. Birds fed high-fiber diets had higher (P < 0.05) jejunal oligosaccharides and cecal SCFA concentrations. Xylanase and protease combination produced the greatest pentose (Pent) levels in low fiber–adequate protein diets but lowest levels in highfiber–low protein diets. There was significant (P < 0.05) fiber × xylanase × protease interaction explained by the digesta concentrations of (Pent) 3 , (Pent) 4 and (Pent) 5 being greatest (P < 0.5) in protease-only supplemented high-fiber diets but lowest in protease-only supplemented low-fiber diets. Furthermore, these results suggest that, of all the factors investigated, dietary fiber level had the greatest effect on modulating digesta concentration of oligosaccharides and cecal SCFA. Evidence points to the fact that there is considerable capacity for generating pentose oligosaccharides in the digestive tract of broilers receiving diets rich in fibrous feedstuffs, and that this may have a beneficial effect on microbial profile in the digestive tract.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Parameterized complex dielectric functions of CuIn 1−x Ga x Se 2 : applications in optical characterization of compositional non‐uniformities and depth profiles in materials and solar cells

Abstract In‐situ spectroscopic ellipsometry (SE) was employed to extract the complex dielectric functions ε = ε 1 + iε 2 over the spectral range of 0.75–6.5 eV for a set of polycrystalline CuIn 1− x Ga x Se 2 (CIGS) thin films with different alloy compositions x = [Ga]/{[In] + [Ga]}. For highest possible accuracy in ε for each CIGS thin film, specialized SE procedures were adopted including (i) deposition to a thickness of ~600 Å on smooth native oxide covered crystal silicon wafers, which minimizes the surface roughness on the film and thus the required corrections in data analysis, and (ii) measurement in‐situ , which minimizes ambient contamination and oxidation of the film surface. Assuming an analytical form for each of the ε spectra for these CIGS films, oscillator parameters were obtained in best fits, and these parameters were fit in turn to polynomials in x . With the resulting database of polynomial coefficients, the ε spectra for any composition of CIGS can be generated from the single parameter, x . In addition to enabling accurate contactless determination of bulk and surface roughness layer thicknesses of CIGS films by high speed multichannel SE, the database enables characterization of the composition and its profile with depth into these films, and even how the depth profile varies spatially within the plane of the films. In this study, depth profile parameters were found to correlate spatially with solar cell performance parameters. As a result, SE provides the capability of contactless compositional analysis of production‐scale CIGS photovoltaic modules at high speed. Copyright © 2016 John Wiley & Sons, Ltd.

Aryal, Puruswottam↗
DOE OSTI2023

Depth profiling and standardization from the back side of a sample for accurate analyses: Emphasis on quantifying low‐fluence, shallow implants in diamond‐like carbon

Rationale Back‐side thinning of wafers is used to eliminate issues with transient sputtering when analyzing near‐surface element distributions. Precise and accurate calibrated implants are created by including a standard reference material during the implantation. Combining these methods allows accurate analysis of low‐fluence, shallow features even if matrix effects are a concern. Methods Implanted Na (<2.0 × 10 11 ions/cm 2 , peaking <50 nm) in diamond‐like carbon (DLC) film on silicon (solar wind returned by NASA's Genesis mission) was prepared for measurement as follows. Implanted surfaces of samples were epoxied to wafers and back‐side‐thinned using physical or chemical methods. Thinned samples were then implanted with reference ions for accurate quantification of the solar wind implant. Analyses used a CAMECA IMS 7f‐GEO SIMS in depth‐profiling mode. Results Back‐side‐implanted reference ions reduced the need to change sample mounts or stage position and could be spatially separated from the solar wind implant even when measuring monoisotopic ions. Matrix effects in DLC were mitigated and the need to find an identical piece of DLC for a reference implant was eliminated. Accuracy was only limited by the back‐side technique itself. Conclusions Combining back‐side depth profiling with back‐side‐implanted internal standards aides quantification of shallow mono‐ and polyisotopic implants. This technique helps mitigate matrix effects and keeps measurement conditions consistent. Depth profile acquisition times are longer, but if sample matrices are homogeneous, procedural changes can decrease measurement times.

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

A simple method for simulating wind profiles in the boundary layer of tropical cyclones

A method to simulate characteristics of wind speed in the boundary layer of tropical cyclones in an idealized manner is developed and evaluated. The method can be used in a single-column modelling set-up with a planetary boundary-layer parametrization, or within large-eddy simulations (LES). The key step is to include terms in the horizontal velocity equations representing advection and centrifugal acceleration in tropical cyclones that occurs on scales larger than the domain size. Compared to other recently developed methods, which require two input parameters (a reference wind speed, and radius from the centre of a tropical cyclone) this new method also requires a third input parameter: the radial gradient of reference wind speed. With the new method, simulated wind profiles are similar to composite profiles from dropsonde observations; in contrast, a classic Ekman-type method tends to overpredict inflow-layer depth and magnitude, and two recently developed methods for tropical cyclone environments tend to overpredict near-surface wind speed. When used in LES, the new technique produces vertical profiles of total turbulent stress and estimated eddy viscosity that are similar to values determined from low-level aircraft flights in tropical cyclones. Lastly, temporal spectra from LES produce an inertial subrange for frequencies ≳0.1 Hz, but only when the horizontal grid spacing ≲20 m.

17 WIND ENERGY↗
DOE OSTI2019

Effects of insertion loss, laser profile and inhomogeneity of dots distribution on properties of all-optical modulator based on GaN/AlN quantum dots

This paper reports the effects of insertion loss, laser profile and inhomogeneity of dots distribution on properties of an all-optical modulator based on spherical quantum dot. The aim of this paper is to give a quantitative description for the variation of main properties of an all-optical quantum dot modulator such as, absorption, transmission and modulation depth regard to insertion loss, laser profile and inhomogeneity of dots. To realize these points, first, we extract the field distribution in optical fiber and channel waveguide (modulator) which are defined by their structure characteristics and boundary conditions. Using the electric field equations, input coupling efficiency and insertion loss and also role of laser profile are observable. Finally we investigate the effect of size distribution and inhomogeneity of quantum dots on the modulator performance. In this structure we used electromagnetically induced transparency (EIT) in GaN/AlN structure, associated with inter-sublevel transitions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

microMS: A Python Platform for Image-Guided Mass Spectrometry Profiling

Image-guided mass spectrometry (MS) profiling provides a facile framework for analyzing samples ranging from single cells to tissue sections. The fundamental workflow utilizes a whole-slide microscopy image to select targets of interest, determine their spatial locations, and subsequently perform MS analysis at those locations. Improving upon prior reported methodology, a software package was developed for working with microscopy images. microMS, for microscopy-guided mass spectrometry, allows the user to select and profile diverse samples using a variety of target patterns and mass analyzers. Written in Python, the program provides an intuitive graphical user interface to simplify image-guided MS for novice users. The class hierarchy of instrument interactions permits integration of new MS systems while retaining the feature-rich image analysis framework. microMS is a versatile platform for performing targeted profiling experiments using a series of mass spectrometers. The flexibility in mass analyzers greatly simplifies serial analyses of the same targets by different instruments. The current capabilities of microMS are presented, and its application for off-line analysis of single cells on three distinct instruments is demonstrated. The software has been made freely available for research purposes. .

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Carbon Nanoparticles and Graphene Nanosheets as MALDI Matrices in Glycomics: a New Approach to Improve Glycan Profiling in Biological Samples

Glycomics continues to be a highly dynamic and interesting research area due to the need to comprehensively understand the biological attributes of glycosylation in many important biological functions such as the immune response, cell development, cell differentiation/adhesion, and host-pathogen interactions. Although matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) has proven to be suitable for glycomic profiling studies, there is a need for improved sensitivity in the detection of native glycans, which ionize inefficiently. In this study, we investigated the efficiencies of graphene nanosheets (GNs) and carbon nanoparticles (CNPs) as MALDI matrices and co-matrices in glycan profiling. Our results indicated an enhancement of signal intensity by several orders of magnitude upon using GNs and CNPs in MALDI analysis of N-glycans derived from a variety of biological samples. Interestingly, increasing the amounts of CNPs and GNs improved not only the signal intensities but also prompted in-source decay (ISD) fragmentations, which produced extensive glycosidic and cross-ring cleavages. Our results indicated that the extent of ISD fragmentation could be modulated by CNP and GN concentrations, to obtain MS{sup 2} and pseudo-MS{sup 3} spectra. The results for glycan profiling in high salt solutions confirmed high salt-tolerance capacities for both CNPs and GNs. Finally, the results showed that by using CNPs and GNs as co-matrices, DHB crystal formation was more homogeneous which improved shot-to-shot reproducibility and sensitivity. .

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2019

ToF-SIMS Depth Profiling of Organic Delta Layers with Low-Energy Cesium Ions: Depth Resolution Assessment

The advent of cluster ion beams has paved the way to the routine 3D analysis of organic heterojunctions. Alternatively, organic thin layers have also been successfully depth profiled with a low-energy cesium ion beam (Cs{sup +}), to exploit the high chemical reactivity of cesium atoms, acting as free-radical scavengers. Despite of this, little is known about the depth resolution associated with low-energy Cs{sup +} sputtering on organic multilayers. In this work, amino acids multilayers, consisting of phenylalanine delta layers alternated with tyrosine spacers, were used as model systems to assess the depth resolution associated with 500 eV Cs{sup +} depth profiles. High yields were obtained for quasi-molecular ions from both amino acids, and no significant chemical alteration was noticed under the monoatomic bombardment. A depth resolution as low as 4 nm is demonstrated without sensible degradation on a rather long profile depth (300 nm). Limited depth resolution (> 10 nm) along with high molecular degradation was previously reported on similar systems by combining low-energy Cs{sup +} with Ga{sup +} analysis beam. The use of the Bi{sub 3}{sup +} analysis beam results in a dramatic improvement of both the characteristic molecular signal intensities and the depth resolution. Even though the analysis beam fluence is very low compared to the sputtering beam fluence, data suggest that further reducing the analysis Bi{sub 3}{sup +} fluence could improve the depth resolution by ~ 1 nm. .

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2017

Inhibition of tissue factor signaling in breast tumour xenografts induces widespread changes in the microRNA expression profile

Highlights: • Clotting protein, tissue factor (TF) mediates intracellular signalling in cancer. • Selective inhibition of TF signalling exerts potent anticancer effect in mice. • Inhibition of TF signalling changes the tumour miR expression profile in vivo. • MiRs altered by blockade of TF signalling share common biological pathways. Tissue factor (TF) is a transmembrane receptor for coagulation factor VII/VIIa and is frequently overexpressed by cancer cells. The TF/VIIa complex acts as the main initiator of the clotting cascade in blood and a trigger of intracellular signaling that changes gene expression and the cellular phenotype. However, pathways mediating these changes are still poorly characterized and especially the impact of TF signals on regulatory microRNA (miR) networks in cancer remains unknown. We show that the monoclonal antibody that selectively neutralises the signaling (but not coagulant) function of human TF (CNTO 2559) inhibits progression of MDA-MB-231 breast cancer xenografts in mice and prolongs animal survival. CNTO 2559 blocks FVIIa-induced expression of interleukin 8 (IL-8) by cancer cells without impacting factor Xa (FXa) generation. Notably, acute exposure of MDA-MB-231 tumour xenografts to CNTO 2559 systemic injections triggers wide spread changes in the tumour miR profile including alterations in 75 miRs (55 downregulated) and impacting several miR-regulated and cancer-related pathways. These results suggest that TF signaling in the tumour microenvironment may provoke vast changes in the miR profile of cancer cells, affect disease biology, and reflect tumour interaction with the coagulation system, thereby presenting itself as a possible biomarker.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Metabololipidomic profiling of functional immunoresolvent clusters and eicosanoids in mammalian tissues

Highlights: • New methods for metabololipidomics of specialized proresolving mediators (SPM) and classic eicosanoids. • Illustration from human blood coagulation. • Illustration from solid tumor. • Regulation of SPM biosynthesis by adenosine and adenosine deaminase. Metabolomics enables a systems approach to interrogate the bioactive mediators, their pathways and further metabolites involved in the physiology and pathophysiology of human and animal tissues. New metabololipidomic approaches with mass spectrometry presented in this brief review can now be utilized for the identification and profiling of lipid mediator networks that control inflammation-resolution in human blood and healthy and diseased solid tissues. Coagulation of blood is a protective response that prevents excessive bleeding on injury of blood vessels. Here, we review novel approaches to understand the relationship(s) between coagulation and resolution of inflammation and infection. To determine whether coagulation is involved in host-protective actions by lipid mediators, we used a metabololipidomic-based profiling approach with human whole blood (WB) during coagulation. We identified recently temporal clusters of endogenously produced pro-thrombotic and proinflammatory lipid mediators (eicosanoids), as well as specialized proresolving mediators (SPMs) in this vital process. In addition to the classic eicosanoids (prostaglandins, thromboxanes and leukotrienes), a specific SPM cluster was identified that consists of resolvin E1 (RvE1), RvD1, RvD5, lipoxin B{sub 4}, and maresin 1, each of which present at bioactive concentrations (0.1–1 nM). The removal of adenosine from coagulating blood samples significantly enhances SPM amounts and unleashes the biosynthesis of RvD3, RvD4, and RvD6 evident following rapid snap freezing with centrifugation before extraction and LC-MS-MS. The classic cyclooxygenase inhibitors, celecoxib and indomethacin, that block thromboxanes and prostanoids do not block production of the clot-driven SPM cluster. Unbiased mass cytometry analysis demonstrated that the SPM cluster produced in human blood targets leukocytes at the single-cell level, directly activating extracellular signaling in human neutrophils and monocytes. Human whole blood treated with the components of this SPM cluster enhanced both phagocytosis and killing of Escherichia coli by leukocytes. Thus, we identified a pro-resolving lipid mediator circuit and specific SPM cluster that promotes host defense. This new lipid mediator (LM)-SPM metabololipidomic approach now provides accessible metabolomic profiles in healthy and diseased human tissues, including cancer, for precision and personalized medicine.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Real-time measurements of temperature, pressure and moisture profiles in High-Performance Concrete exposed to high temperatures during neutron radiography imaging

High-Performance Concrete (HPC) is particularly prone to explosive spalling when exposed to high temperature. Although the exact causes that lead to spalling are still being debated, moisture transport during heating plays an important role in all proposed mechanisms. In this study, slabs made of high-performance, low water-to-binder ratio mortars with addition of superabsorbent polymers (SAP) and polypropylene fibers (PP) were heated from one side on a temperature-controlled plate up to 550 °C. A combination of measurements was performed simultaneously on the same sample: moisture profiles via neutron radiography, temperature profiles with embedded thermocouples and pore pressure evolution with embedded pressure sensors. Spalling occurred in the sample with SAP, where sharp profiles of moisture and temperature were observed. No spalling occurred when PP-fibers were introduced in addition to SAP. The experimental procedure described here is essential for developing and verifying numerical models and studying measures against fire spalling risk in HPC.

42 ENGINEERING↗
DOE OSTI2015

Interface profile optimization for planar stress wave attenuation in bi-layered plates

Stress waves scatter upon entering a new medium. This occurs due to the reflection and transmission of the waves, which depends on the impedance mismatch between the two materials and the angle of incidence. For a bi-layered structure with finite dimensions and constant impedance ratio, the scattering and intensity of the stress waves may be varied by changing the interface profile between the two layers. In this study, a methodology is proposed for optimizing the interface profile between the layers of a finite bi-layered plate for the objective of planar stress wave attenuation. The bi-layered plates are subjected at one end to highly impulsive loadings with various durations, and the geometry of the internal interface is optimized for the purpose of minimizing the amplitude of the maximum reaction force at the opposite fixed end. The optimization methodology is based on a genetic algorithm, which is coupled with a finite element method for analyzing the wave propagation behavior of the plates. Finally, it is observed that the interface profile and the amount of stress wave attenuation depend on the duration of the applied impulsive loading, with higher amounts of attenuation obtained when the wavelength associated with the impulsive load is small compared to the dimensions of the bi-layered plates.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Solving the duck curve in a smart grid environment using a non-cooperative game theory and dynamic pricing profiles

With the intermittency that comes with electricity generation from renewables, utilizing dynamic pricing will encourage the demand-side to respond in a smart way that would minimize the electricity costs and flatten the net electricity demand curve. Determining the optimal dynamic pricing profile that would leverage distributed storage to flatten the curve is a novel idea that needs to be studied. Moreover, the economic feasibility of utilizing distributed electrical energy storage is still not given in the literature. Therefore, in this paper, a novel way of solving a citywide dynamic model using a bilevel programming algorithm is introduced. The problem is developed as a novel non-cooperative Stackelberg game that utilizes air-conditioning systems and electrical storage through the end-users to determine the optimal dynamic pricing profile. The results show that the combined effect of utilizing demand-side air-conditioning systems and distributed storage together can flatten the curve while employing the optimal dynamic pricing profile. An economic study is performed to determine the economic feasibility of 20 different cases with different battery designs and the level of solar penetration. Three metrics were used to evaluate the economic performance of each case: the levelized cost of storage, the levelized cost of energy, and the simple payback period. Most cases had levelized cost of storage values lower than 0.457 $/kWh, which is the lower bound available in the literature. Seven out of 16 cases have a simple payback period shorter than the lifetime of the system (25 years). The case with a 100 MW PV power plant and a battery storage of size 597 MWh, was found to be the most promising case with a simple payback period of 12.71 years for the photovoltaic plant and 19.86 years for the demand-side investments.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

A deep redox proteome profiling workflow and its application to skeletal muscle of a Duchenne Muscular Dystrophy model

Perturbation to the redox state accompanies many diseases and its effects are viewed through oxidation of biomolecules, including proteins, lipids, and nucleic acids. The thiol groups of protein cysteine residues undergo an array of redox post-translational modifications (PTMs) that are important for regulation of protein and pathway function. To better understand what proteins are redox regulated following a perturbation, it is important to be able to comprehensively profile protein thiol oxidation at the proteome level. Herein, we report a deep redox proteome profiling workflow and demonstrate its application in measuring the changes in thiol oxidation along with global protein expression in skeletal muscle from mdx mice, a model of Duchenne Muscular Dystrophy (DMD). In depth coverage of the thiol proteome was achieved with >18,000 Cys sites from 5608 proteins in muscle being quantified. Compared to the control group, mdx mice exhibit markedly increased thiol oxidation, where ~2% shift in the median oxidation occupancy was observed. Further, pathway analysis for the redox data revealed that coagulation system and immune-related pathways were among the most susceptible to increased thiol oxidation in mdx mice, whereas protein abundance changes were more enriched in pathways associated with bioenergetics. This study illustrates the importance of deep redox profiling in gaining greater insight into oxidative stress regulation and pathways/processes that are perturbed in an oxidizing environment.

60 APPLIED LIFE SCIENCES↗