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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

The use of multidimensional scaling for facilities layout - An application to the design of the Space Station

Before an optimum layout of the facilities for the proposed Space Station can be designed, it is necessary to understand the functions that will be performed by the Space Station crew and the relationships among those functions. Five criteria for assessing functional relationships were identified. For each of these criteria, a matrix representing the degree of association of all pairs of functions was developed. The key to making inferences about the layout of the Space Station from these matrices was the use of multidimensional scaling (MDS). Applying MDS to these matrices resulted in spatial configurations of the crew functions in which smaller distances in the MDS configuration reflected closer associations. An MDS analysis of a composite matrix formed by combining the five individual matrices resulted in two dimensions that describe the configuration: a 'private-public' dimension and a 'group-individual' dimension. Seven specific recommendations for Space Station layout were derived from analyses of the MDS configurations. Although these techniques have been applied to the design of the Space Station, they can be applied to the design of any facility where people live or work.

Tullis, Thomas S.↗
NASA NTRS1994

Hubble Space Telescope Medium Deep Survey. 2: Deconvolution of Wide Field Camera field galaxy images in the 13 hour + 43 deg field

We present isophotal profiles of six faint field galaxies from some of the first deep images taken for the Hubble Space Telescope (HST) Medium Deep Survey (MDS). These have redshifts in the range z = 0.126 to 0.402. The images were taken with the Wide Field Camera (WFC) in `parallel mode' and deconvolved with the Lucy method using as the point-spread function nearby stars in the image stack. The WFC deconvolutions have a dynamic range of 16 to 20 dB (4 to 5 mag) and an effective resolution approximately less than 0.2 sec (FWHM). The multiorbit HST images allow us to trace the morphology, light profiles, and color gradients of faint field galaxies down to V approximately equal to 22 to 23 mag at sub-kpc resolution, since the redshift range covered is z = 0.1 to 0.4. The goals of the MDS are to study the sub-kpc scale morphology, light profiles, and color gradients for a large samole of faint field galaxies down to V approximately equal to 23 mag, and to trace the fraction of early to late-type galaxies as function of cosmic time. In this paper we study the brighter MDS galaxies in the 13 hour + 43 deg MDS field in detail, and investigate to what extent model fits with pure exponential disks or a(exp 1/4) bulges are justified at V approximately less than 22 mag. Four of the six field galaxies have light profiles that indicate (small) inner bulges following r(exp 1/4) laws down to 0.2 sec resolution, plus a dominant surrounding exponential disk with little or no color gradients. Two occur in a group at z = 0.401, two are barred spiral galaxies at z = 0.179 and z = 0.302, and two are rather subluminous (and edge-on) disk galaxies at z = 0.126 and z = 0.179. Our deep MDS images can detect galaxies down to V, I approximately less than 25 to 26 mag, and demonstrate the impressive potential of HST--even with its pre-refurbished optics--to resolve morphological details in galaxies at cosmologically significant distances (v approximately less than 23 mag). Since the median redshift of these galaxies is approximately less than 0.4, the HST resolution allows us to study sub kpc size scales at the galaxy, which cannot be done with stable images over wide fields from the best ground-based sites.

Windhorst, R. A.↗
NASA NTRS2008

Mice Drawer System

The Mice Drawer System (MDS) is an Italian Space Agency (ASI) facility which is able to support mice onboard the International Space Station during long-duration exploration missions (from 100 to 150-days) by living space, food, water, ventilation and lighting. Mice can be accommodated either individually (maximum 6) or in groups (4 pairs). MDS is integrated in the Space Shuttle middeck during transportation (uploading and downloading) to the ISS and in an EXPRESS Rack in Destiny, the US Laboratory during experiment execution. Osteoporosis is a debilitating disease that afflicts millions of people worldwide. One of the physiological changes experienced by astronauts during space flight is the accelerated loss of bone mass due to the lack of gravitational loading on the skeleton. This bone loss experienced by astronauts is similar to osteoporosis in the elderly population. MDS will help investigate the effects of unloading on transgenic (foreign gene that has been inserted into its genome to exhibit a particular trait) mice with the Osteoblast Stimulating Factor-1, OSF-1, a growth and differentiation factor, and to study the genetic mechanisms underlying the bone mass pathophysiology. MDS will test the hypothesis that mice with an increased bone density are likely to be more protected from osteoporosis, when the increased bone mass is a direct effect of a gene involved in skeletogenesis (skeleton formation). Osteoporosis is a debilitating disease that afflicts millions worldwide. One of the physiological changes experienced by astronauts during space flight is the accelerated loss of bone mass due to the lack of gravitational loading on the skeleton, a loss that is similar to osteoporosis in the elderly population on Earth. Osteoblast Stimulating Factor-1 (OSF-1), also known as pleiotrophin (PTN) or Heparin-Binding Growth- Associated Molecule (HB-GAM) belongs to a family of secreted heparin binding proteins..OSF-1 is an extracellular matrix-associated growth and differentiation factor that is normally expressed in cartilage; it can stimulate the proliferation and differentiation of human osteoprogenitor cells (cell that differentiate into an osteoblast) in vitro. The Mice Drawer System will study the effects of microgravity on transgenic mouse bones in order to identify genetic mechanisms playing a role in the reduction of the bone mass observed in humans and animals as a consequence of long-duration (greater than 100 days) microgravity exposure. Onboard the ISS, MDS is relatively self-sufficient; a crewmember will check the health status of the rodents on a daily basis, by assessing them through the viewing window. Water levels will be assessed by the crew daily and refilled as needed. Replacement of the food bars and replacement of the waste filters will be conducted inflight by crewmembers every 20-days.

Cancedda, Ranieri↗
DOE OSTI2014

Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots

We have examined the origins of interlayer formation and misfit dislocation (MD) displacement in the vicinity of InAs/GaAs quantum dots (QDs). For QDs formed by the Stranski-Krastanov mode, regularly spaced MDs nucleate at the interface between the QD and the GaAs buffer layer. In the droplet epitaxy case, both In island formation and In-induced “nano-drilling” of the GaAs buffer layer are observed during In deposition. Upon annealing under As flux, the In islands are converted to InAs QDs, with an InGaAs interlayer at the QD/buffer interface. Meanwhile, MDs nucleate at the QD/interlayer interface.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2013

Cross-field diffusion of energetic (100 keV to 2 MeV) protons in interplanetary space

Magnetic field magnitude decreases (MDs) are observed in several regions of the interplanetary medium. In this paper, we characterize MDs observed by the Ulysses spacecraft instrumentation over the solar south pole by using magnetic field data to obtain the empirical size, magnetic field MD, and frequency of occurrence distribution functions. The interaction of energetic (100 keV to 2 MeV) protons with these MDs is investigated. Charged particle and MD interactions can be described by a geometrical model allowing the calculation of the guiding center shift after each interaction. Using the distribution functions for the MD characteristics, Monte Carlo simulations are used to obtain the cross-field diffusion coefficients as a function of particle kinetic energy. It is found that the protons under consideration cross-field diffuse at a rate of up to ≈11% of the Bohm rate. The same method used in this paper can be applied to other space regions where MDs are observed, once their local features are well known.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

Identifying critical resiliency of modern distribution systems with open source modeling

Identification of temporal and topology related challenges to the operation of modern distribution systems (MDS) with high penetration of distributed energy resources is critical to developing and assessing control strategies. This paper proposes analysis of typical and historical load and generation patterns to identify and anticipate critical intersections in generation and load that stress distribution system stability. An open source modeling of representative MDS topologies, loads, and generation is presented to aid further analysis of the interaction of MDS control strategies with load and generation patterns to determine intrinsic adaptive capacity of segments of MDS.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2014

CMI Report on Project 2.3.2 Activities – 09/2013 to 03/2014

The objective of this project is to develop and apply a Materials-Design Simulator (MDS) for predicting thermodynamic phase stability, structural and magnetic properties, and performance of complex REE-based materials. We seek to create a knowledge base for identifying alloys with desirable properties. The aim of this project is to develop an efficient infrastructure for creating a knowledge base for identifying new alloys with enhance performance and reduced REE-content, and for managing material data acquired within the Focus Area 2 and with input from Focus Area 4. This project integrates two approaches to alloy process modeling that so far have been developed largely independently: (1) electronic structure theory of alloys and (2) semi-empirical methods of computational thermodynamics and kinetics (such as CALPHAD). This project will greatly benefit from experimental data on phase characterization, heat of formation (from differential scanning calorimetry), and magnetism as a function of pressure to support the search for REE substitutes without compromising on target properties for applications. The MDS will be also greatly enhanced through the use of state-of-the-art methods of materials informatics and data mining. The MDS will facilitate examination of research results, discovery of trends, identification of knowledge gaps, and even possibly underlying scientific principles, MDS will be developed and assembled for gathering, accessing, and analyzing available material data generated externally and within CMI projects by experimentalists and modelers. The data in our knowledge base will be accessible to all hub participants via a web interface and underlying engine that will allow targeted searches through heterogeneous data on composition, property and structure spaces encompassing all contributed data.

36 MATERIALS SCIENCE↗
NASA NTRS1988

A framework for implementing data services in multi-service mobile satellite systems

Mobile satellite systems being planned for introduction in the early 1990s are expected to be invariably of the multi-service type. Mobile Telephone Service (MTS), Mobile Radio Service (MRS), and Mobile Data Service (MDS) are the major classifications used to categorize the many user applications to be supported. The MTS and MRS services encompass circuit-switched voice communication applications, and may be efficiently implemented using a centralized Demand-Assigned Multiple Access (DAMA) scheme. Applications under the MDS category are, on the other hand, message-oriented and expected to vary widely in characteristics; from simplex mode short messaging applications to long duration, full-duplex interactive data communication and large file transfer applications. For some applications under this service category, the conventional circuit-based DAMA scheme may prove highly inefficient due to the long time required to set up and establish communication links relative to the actual message transmission time. It is proposed that by defining a set of basic bearer services to be supported in MDS and optimizing their transmission and access schemes independent of the MTS and MRS services, the MDS applications can be more efficiently integrated into the multi-service design of mobile satellite systems.

Ali, Mohammed O.↗
NASA NTRS1993

Real-time expert system diagnostics and monitoring for the High Resolution Microwave Survey Targeted Search

An automated monitoring and diagnostics system (MDS) using virtual real-time software was developed for NASA's High Resolution Microwave Survey (HRMS) Targeted Search System (TSS). The four main tasks required of the MDS were monitoring and recording system health, alerting operators of problems, diagnosing poor system performance, and performing an emergency system shutdown. The MDS was implemented using commercial expert system software tools in addition to interface hardware and software developed on site. The expert system used objects, rules, and schematics in its TSS knowledge representation. The MDS was successfully integrated into the HRMS computer environment, and its performance met or exceeded its requirements.

Macalou, A.↗
DOE OSTI2017

A Tritium Management Tool for Light Water Detritiation - 17320

Kurion{sup R}, Inc. (Kurion) has developed the Modular Detritiation System (MDS{sup R}) based on the working principle of combined electrolysis catalytic exchange (CECE), offering a combination of efficiency, maturity, and cost among alternatives. The technology builds on proven heavy water solutions, and although is focused on light water, it can be adapted for heavy water detritiation. The application of MDS{sup R} is a modular approach and allows for a flexible design that is adaptable to a range of facility sizes and processing needs. This modular approach delivers a factory quality and plug-n-process system that utilizes commercially available equipment and minimizes impact to a facility's day-to-day operations. In addition to focusing on optimization of the MDS{sup R} technology, Kurion has strategies for a complete detritiation solution of which MDS{sup R} is a part of. The strategy, supported by modeling and numerical analysis, is a systematic approach to managing front-end pretreatment (if required), overall volume reduction, and amount and method of tritium retention. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

c-Src activation through a TrkA and c-Src interaction is essential for cell proliferation and hematological malignancies

Highlights: •TrkA was mainly present in other types of leukemia including AML. •TrkA enhances the survival of leukemia by activation of PI3K/Akt pathway. •TrkA induced significant hematological malignancies by inducing PLK-1 and Twist-1. •TrkA acted as a key regulator of leukemogenesis and survival through c-Src activation. -- Abstract: Although the kinase receptor TrkA may play an important role in acute myeloid leukemia (AML), its involvement in other types of leukemia has not been reported. Furthermore, how it contributes to leukemogenesis is unknown. Here, we describe a molecular network that is important for TrkA function in leukemogenesis. We found that TrkA is frequently overexpressed in other types of leukemia such as acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS) including AML. In addition, TrkA was overexpressed in patients with MDS or secondary AML evolving from MDS. TrkA induced significant hematological malignancies by inducing PLK-1 and Twist-1, and enhanced survival and proliferation of leukemia, which was correlated with activation of the phosphatidylinositol 3-kinase/Akt/mTOR pathway. Moreover, endogenous TrkA associated with c-Src complexes was detected in leukemia. Suppression of c-Src activation by TrkA resulted in markedly decreased expression of PLK-1 and Twist-1 via suppressed activation of Akt/mTOR cascades. These data suggest that TrkA plays a key role in leukemogenesis and reveal an unexpected physiological role for TrkA in the pathogenesis of leukemia. These data have important implications for understanding various hematological malignancies.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Effect of Cu2+ Activation on Interfacial Water Structure at the Sphalerite Surface as Studied by Molecular Dynamics Simulation

In the first part of this paper, an experimental contact angle study of the fresh and Cu2+ activated sphalerite-ZnS surface as well as the covellite-CuS (001) surface is reported describing the increased hydrophobic character of the surface during Cu2+ activation. In addition to these experimental results, the fresh sphalerite-ZnS (110), copper-zinc sulfide-CuZnS2 (110), villamaninite- CuS2 (100), and covellite-CuS (001) surfaces were examined using Molecular Dynamics Simulation (MDS). Our MDS results on the behavior of interfacial water at the fresh sphalerite-ZnS (110), copper-zinc sulfide-CuZnS2 (110), villamaninite-CuS2 (100), and covellite-CuS (001) surfaces include simulated contact angles, water number density distribution, water dipole orientation, water residence time, and hydrogen-bonding considerations. The copper content at the Cu2+ activated sphalerite surface seems to account for the increased hydrophobicity as revealed by both experimental and MD simulated contact angle measurements. The relatively greater hydrophobic character developed at the Cu2+ activated sphalerite surface and at the copper-zinc sulfide surface has been described by MDS, based on the structure of interfacial water and its dynamic properties. L.X.D. acknowledges funding from the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences.

Jin, Jiaqi↗
DOE OSTI2014

Rapidly evolving and luminous transients from Pan-STARRS1

In the past decade, several rapidly evolving transients have been discovered whose timescales and luminosities are not easily explained by traditional supernovae (SNe) models. The sample size of these objects has remained small due, at least in part, to the challenges of detecting short timescale transients with traditional survey cadences. Here we present the results from a search within the Pan-STARRS1 Medium Deep Survey (PS1-MDS) for rapidly evolving and luminous transients. We identify 10 new transients with a time above half-maximum (t {sub 1/2}) of less than 12 days and –16.5 > M > –20 mag. This increases the number of known events in this region of SN phase space by roughly a factor of three. The median redshift of the PS1-MDS sample is z = 0.275 and they all exploded in star-forming galaxies. In general, the transients possess faster rise than decline timescale and blue colors at maximum light (g {sub P1} – r {sub P1} ≲ –0.2). Best-fit blackbodies reveal photospheric temperatures/radii that expand/cool with time and explosion spectra taken near maximum light are dominated by a blue continuum, consistent with a hot, optically thick, ejecta. We find it difficult to reconcile the short timescale, high peak luminosity (L > 10{sup 43} erg s{sup –1}), and lack of UV line blanketing observed in many of these transients with an explosion powered mainly by the radioactive decay of {sup 56}Ni. Rather, we find that many are consistent with either (1) cooling envelope emission from the explosion of a star with a low-mass extended envelope that ejected very little (<0.03 M {sub ☉}) radioactive material, or (2) a shock breakout within a dense, optically thick, wind surrounding the progenitor star. After calculating the detection efficiency for objects with rapid timescales in the PS1-MDS we find a volumetric rate of 4800-8000 events yr{sup –1} Gpc{sup –3} (4%-7% of the core-collapse SN rate at z = 0.2).

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

SELECTION OF BURST-LIKE TRANSIENTS AND STOCHASTIC VARIABLES USING MULTI-BAND IMAGE DIFFERENCING IN THE PAN-STARRS1 MEDIUM-DEEP SURVEY

We present a novel method for the light-curve characterization of Pan-STARRS1 Medium Deep Survey (PS1 MDS) extragalactic sources into stochastic variables (SVs) and burst-like (BL) transients, using multi-band image-differencing time-series data. We select detections in difference images associated with galaxy hosts using a star/galaxy catalog extracted from the deep PS1 MDS stacked images, and adopt a maximum a posteriori formulation to model their difference-flux time-series in four Pan-STARRS1 photometric bands g {sub P1}, r {sub P1}, i {sub P1}, and z {sub P1}. We use three deterministic light-curve models to fit BL transients; a Gaussian, a Gamma distribution, and an analytic supernova (SN) model, and one stochastic light-curve model, the Ornstein-Uhlenbeck process, in order to fit variability that is characteristic of active galactic nuclei (AGNs). We assess the quality of fit of the models band-wise and source-wise, using their estimated leave-out-one cross-validation likelihoods and corrected Akaike information criteria. We then apply a K-means clustering algorithm on these statistics, to determine the source classification in each band. The final source classification is derived as a combination of the individual filter classifications, resulting in two measures of classification quality, from the averages across the photometric filters of (1) the classifications determined from the closest K-means cluster centers, and (2) the square distances from the clustering centers in the K-means clustering spaces. For a verification set of AGNs and SNe, we show that SV and BL occupy distinct regions in the plane constituted by these measures. We use our clustering method to characterize 4361 extragalactic image difference detected sources, in the first 2.5 yr of the PS1 MDS, into 1529 BL, and 2262 SV, with a purity of 95.00% for AGNs, and 90.97% for SN based on our verification sets. We combine our light-curve classifications with their nuclear or off-nuclear host galaxy offsets, to define a robust photometric sample of 1233 AGNs and 812 SNe. With these two samples, we characterize their variability and host galaxy properties, and identify simple photometric priors that would enable their real-time identification in future wide-field synoptic surveys.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Assessing the methane mitigation potential of innovative management in US rice production

Abstract Rice is an important global crop while also contributing significant anthropogenic methane (CH 4 ) emissions. To support the future of rice production, more information is needed on the impacts of sustainability-driven management used to grow rice with lower associated methane emissions. Recent support for the impacts of different growing practices in the US has prompted the application of a regional methodology (Tier 2) to estimate methane emissions in different rice growing regions. The methodology estimates rice methane emissions from the US Mid-South (MdS) and California (Cal) using region-specific scaling factors applied to a region-specific baseline flux. In our study, we leverage land cover data and soil clay content to estimate methane emissions using this approach, while also examining how changes in common production practices can affect overall emissions in the US. Our results indicated US rice cultivation produced between 0.32 and 0.45 Tg CH 4 annually, which were approximately 7% and 42% lower on average compared to Food and Agriculture Organization of the UN (FAO) and US Environmental Protection Agency (EPA) inventories, respectively. Our estimates were 63% greater on average compared to similar methods that lack regional context. Introducing aeration events into irrigation resulted in the greatest methane reductions across both regions. When accounting for differences between baseline and reduction scenarios, the US MdS typically had higher mitigation potential compared to Cal. The differences in cumulative mitigation potential across the 2008–2020 period were likely driven by lower production area clay content for the US MdS compared to Cal. The added spatial representation in the Tier 2 approach is useful in surveying how impactful methane-reducing practices might be within and across regions.

Environmental Sciences & Ecology↗
DOE OSTI2021

Multi-Dimensional Scaling on Groups

Leveraging the intrinsic symmetries in data for clear and efficient analysis is an important theme in signal processing and other data-driven sciences. A basic example of this is the ubiquity of the discrete Fourier transform which arises from translational symmetry (i.e. time-delay/phase-shift). Particularly important in this area is understanding how symmetries inform the algorithms that we apply to our data. In this paper we explore the behavior of the dimensionality reduction algorithm multi-dimensional scaling (MDS) in the presence of symmetry. We show that understanding the properties of the underlying symmetry group allows us to make strong statements about the output of MDS even before applying the algorithm itself. In analogy to Fourier theory, we show that in some cases only a handful of fundamental ``frequencies'' (irreducible representations derived from the corresponding group) contribute information for the MDS Euclidean embedding.

Dimensionality reduction, Representation theory, D↗
DOE OSTI2014

A Structure-Based Distance Metric for High-Dimensional Space Exploration with Multi-Dimensional Scaling

Although the Euclidean distance does well in measuring data distances within high-dimensional clusters, it does poorly when it comes to gauging inter-cluster distances. This significantly impacts the quality of global, low-dimensional space embedding procedures such as the popular multi-dimensional scaling (MDS) where one can often observe non-intuitive layouts. We were inspired by the perceptual processes evoked in the method of parallel coordinates which enables users to visually aggregate the data by the patterns the polylines exhibit across the dimension axes. We call the path of such a polyline its structure and suggest a metric that captures this structure directly in high-dimensional space. This allows us to better gauge the distances of spatially distant data constellations and so achieve data aggregations in MDS plots that are more cognizant of existing high-dimensional structure similarities. Our MDS plots also exhibit similar visual relationships as the method of parallel coordinates which is often used alongside to visualize the high-dimensional data in raw form. We then cast our metric into a bi-scale framework which distinguishes far-distances from near-distances. The coarser scale uses the structural similarity metric to separate data aggregates obtained by prior classification or clustering, while the finer scale employs the appropriate Euclidean distance.

Clustering↗