The Concept Design of a Split Flow Liquid Hydrogen Turbopump

An initial design of a split flow liquid hydrogen turbopump for the Dual Expander Aerospike Nozzle (DEAN) upper stage engine was completed. The engine nozzle is an annular aerospike. The engine cycle requires a combustion chamber pressure of 1,740 psia. The DEAN is designed to deliver 57,200 lbf of thrust and 472 seconds of Isp. The turbopump design was completed using a meanline software tool. The design consists of a single piece rotor, with a two-stage pump and radial inflow turbine. The turbopump flow rates are 15.1 and 7.55 lbm/s into the first and second stage, respectively. The first and second stage pumps use unshrouded impellers. An interstage transfer models the fluid split flow. The fluid for each stage exits through a volute. The first and second stage impeller hub-tip ratios are 0.3 and 0.35, respectively. The turbine is a full admission reaction type. At the design condition, the turbine delivers 3,607 horsepower at a total pressure ratio of 1.84

Guidelines for Affirmative Social Work Education: Enhancing the Climate for LGBQQ Students, Staff, and Faculty in Social Work Education

This report is intended to provide guidelines for the creation of social work educational environments that are affirmative of lesbian, gay, bisexual, queer, and questioning (LGBQQ) students, faculty, administrators, and staff. Creating affirmative social work educational environments for transgender and gender nonconforming populations is addressed in a companion document, Guidelines for Transgender and Gender Nonconforming (TGNC) Inclusive Social Work Education

Microstructural and continuum evolution modeling of sintering.

All ceramics and powder metals, including the ceramics components that Sandia uses in critical weapons components such as PZT voltage bars and current stacks, multi-layer ceramic MET's, ahmindmolybdenum & alumina cermets, and ZnO varistors, are manufactured by sintering. Sintering is a critical, possibly the most important, processing step during manufacturing of ceramics. The microstructural evolution, the macroscopic shrinkage, and shape distortions during sintering will control the engineering performance of the resulting ceramic component. Yet, modeling and prediction of sintering behavior is in its infancy, lagging far behind the other manufacturing models, such as powder synthesis and powder compaction models, and behind models that predict engineering properties and reliability. In this project, we developed a model that was capable of simulating microstructural evolution during sintering, providing constitutive equations for macroscale simulation of shrinkage and distortion during sintering. And we developed macroscale sintering simulation capability in JAS3D. The mesoscale model can simulate microstructural evolution in a complex powder compact of hundreds or even thousands of particles of arbitrary shape and size by 1. curvature-driven grain growth, 2. pore migration and coalescence by surface diffusion, 3. vacancy formation, grain boundary diffusion and annihilation. This model was validated by comparing predictions of the simulation to analytical predictions for simple geometries. The model was then used to simulate sintering in complex powder compacts. Sintering stress and materials viscous module were obtained from the simulations. These constitutive equations were then used by macroscopic simulations for simulating shrinkage and shape changes in FEM simulations. The continuum theory of sintering embodied in the constitutive description of Skorohod and Olevsky was combined with results from microstructure evolution simulations to model shrinkage and deformation during. The continuum portion is based on a finite element formulation that allows 3D components to be modeled using SNL's nonlinear large-deformation finite element code, JAS3D. This tool provides a capability to model sintering of complex three-dimensional components. The model was verified by comparing to simulations results published in the literature. The model was validated using experimental results from various laboratory experiments performed by Garino. In addition, the mesoscale simulations were used to study anisotropic shrinkage in aligned, elongated powder compacts. Anisotropic shrinkage occurred in all compacts with aligned, elongated particles. However, the direction of higher shrinkage was in some cases along the direction of elongation and in other cases in the perpendicular direction depending on the details of the powder compact. In compacts of simple-packed, mono-sized, elongated particles, shrinkage was higher in the direction of elongation. In compacts of close-packed, mono-sized, elongated particles and of elongated particles with a size and shape distribution, the shrinkage was lower in the direction of elongation. We also explored the concept of a sintering stress tensor rather than the traditional sintering stress scalar concept for the case of anisotropic shrinkage. A thermodynamic treatment of this is presented. A method to calculate the sintering stress tensor is also presented. A user-friendly code that can simulate microstructural evolution during sintering in 2D and in 3D was developed. This code can run on most UNIX platforms and has a motif-based GUI. The microstructural evolution is shown as the code is running and many of the microstructural features, such as grain size, pore size, the average grain boundary length (in 2D) and area (in 3D), etc. are measured and recorded as a function of time. The overall density as the function of time is also recorded

Characterization of collective ground states in single-layer NbSe2

Layered transition metal dichalcogenides (TMDs) are ideal systems for exploring the effects of dimensionality on correlated electronic phases such as charge density wave (CDW) order and superconductivity. In bulk NbSe2 a CDW sets in at TCDW = 33 K and superconductivity sets in at Tc = 7.2 K. Below Tc these electronic states coexist but their microscopic formation mechanisms remain controversial. Here we present an electronic characterization study of a single 2D layer of NbSe2 by means of low temperature scanning tunneling microscopy/spectroscopy (STM/STS), angle-resolved photoemission spectroscopy (ARPES), and electrical transport measurements. We demonstrate that 3x3 CDW order in NbSe2 remains intact in 2D. Superconductivity also still remains in the 2D limit, but its onset temperature is depressed to 1.9 K. Our STS measurements at 5 K reveal a CDW gap of {\Delta} = 4 meV at the Fermi energy, which is accessible via STS due to the removal of bands crossing the Fermi level for a single layer. Our observations are consistent with the simplified (compared to bulk) electronic structure of single-layer NbSe2, thus providing new insight into CDW formation and superconductivity in this model strongly-correlated system.Comment: Nature Physics (2015), DOI:10.1038/nphys352

Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts

As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is currently a lack of comprehensive, empirical data about the processes, interactions and feedbacks in complex human-water systems leading to flood and drought impacts. Here we present a benchmark dataset containing socio-hydrological data of paired events, i.e., two floods or two droughts that occurred in the same area. The 45 paired events occurred in 42 different study areas and cover a wide range of socio-economic and hydro-climatic conditions. The dataset is unique in covering both floods and droughts, in the number of cases assessed, and in the quantity of socio-hydrological data. The benchmark dataset comprises: 1) detailed review style reports about the events and key processes between the two events of a pair; 2) the key data table containing variables that assess the indicators which characterise management shortcomings, hazard, exposure, vulnerability and impacts of all events; 3) a table of the indicators-of-change that indicate the differences between the first and second event of a pair. The advantages of the dataset are that it enables comparative analyses across all the paired events based on the indicators-of-change and allows for detailed context- and location-specific assessments based on the extensive data and reports of the individual study areas. The dataset can be used by the scientific community for exploratory data analyses e.g. focused on causal links between risk management, changes in hazard, exposure and vulnerability and flood or drought impacts. The data can also be used for the development, calibration and validation of socio-hydrological models. The dataset is available to the public through the GFZ Data Services (Kreibich et al. 2023, link for review: https://dataservices.gfz-potsdam.de/panmetaworks/review/923c14519deb04f83815ce108b48dd2581d57b90ce069bec9c948361028b8c85/).</p

Histopathological findings of infections caused by canine distemper virus, Trypanosoma cruzi, and other parasites in two free-ranging White-nosed Coatis Nasua narica (Carnivora: Procyonidae) from Costa Rica

Canine distemper virus (CDV) causes systemic infections and immunosuppression in carnivores, which subsequently makes animals highly susceptible to opportunistic infections. Although Trypanosoma cruzi infects procyonids, chagasic myocarditis in Coatis has not been reported in Central America. The aim of this study was to report the histopathological findings caused by canine distemper virus, T. cruzi, and other parasites in two free-ranging White-nosed Coatis Nasua narica found dead in a national park on the Pacific coast of Costa Rica. Heart, lung, tongue, liver, brain and spleen samples were subjected to macroscopic and microscopic examination. A mononuclear meningoencephalitis associated with intra-nuclear eosinophilic inclusion bodies consistent with canine distemper virus was observed in nervous tissue. Myocarditis and associated nests of amastigotes of T. cruzi were observed during microscopic examination in cardiac tissue, and in muscle from the tongue of both animals. Molecular analysis confirmed T. cruzi in formalin-fixed paraffin embedded cardiac tissues. The myocardial damage caused by the opportunistic infection due to T. cruzi in these individuals could be the result of a severe compromised immunological status associated to the CDV infection, and subsequent opportunistic polyparasitism described herein. To the authors knowledge this is the first report of chagasic myocarditis in free-ranging coatis from Central America.El virus del moquillo canino (VDC) provoca infecciones sistémicas e inmunosupresión en los carnívoros, lo que posteriormente hace que los animales sean muy susceptibles a las infecciones oportunistas. Aunque Trypanosoma cruzi infecta a los procónidos, en Centroamérica no se ha informado de la existencia de una miocarditis chagásica en los coatis. El objetivo de este estudio fue reportar los hallazgos histopatológicos causados por el virus del moquillo canino, T. cruzi y otros parásitos en dos Coatis Nasua narica en libertad encontrados muertos en un parque nacional en la costa del Pacífico de Costa Rica. Se sometieron a examen macroscópico y microscópico muestras de corazón, pulmón, lengua, hígado, cerebro y bazo. En el tejido nervioso se observó una meningoencefalitis mononuclear asociada a cuerpos de inclusión eosinófilos intranucleares compatibles con el virus del moquillo canino. Durante el examen microscópico se observaron miocarditis y nidos asociados de amastigotes de T. cruzi en el tejido cardíaco y en el músculo de la lengua de ambos animales. El análisis molecular confirmó la presencia de T. cruzi en los tejidos cardíacos fijados en parafina. El daño miocárdico causado por la infección oportunista debida a T. cruzi en estos individuos podría ser el resultado de un estado inmunológico severamente comprometido asociado a la infección por CDV, y al posterior poliparasitismo oportunista aquí descrito. Hasta donde saben los autores, éste es el primer informe de miocarditis chagásica en coatíes en libertad de América Central.Universidad de Georgia, Estados Unidos.Universidad Nacional, Costa Rica.Universidad Nacional Autónoma de México, México.Escuela de Medicina Veterinari

RIG-I-Mediated Antiviral Signaling Is Inhibited in HIV-1 Infection by a Protease-Mediated Sequestration of RIG-I▿

The rapid induction of type I interferon (IFN) is essential for establishing innate antiviral responses. During infection, cytoplasmic viral RNA is sensed by two DExD/H box RNA helicases, RIG-I and MDA5, ultimately driving IFN production. Here, we demonstrate that purified genomic RNA from HIV-1 induces a RIG-I-dependent type I IFN response. Both the dimeric and monomeric forms of HIV-1 were sensed by RIG-I, but not MDA5, with monomeric RNA, usually found in defective HIV-1 particles, acting as a better inducer of IFN than dimeric RNA. However, despite the presence of HIV-1 RNA in the de novo infection of monocyte-derived macrophages, HIV-1 replication did not lead to a substantial induction of IFN signaling. We demonstrate the existence of an evasion mechanism based on the inhibition of the RIG-I sensor through the action of the HIV-1 protease (PR). Indeed, the ectopic expression of PR resulted in the inhibition of IFN regulatory factor 3 (IRF-3) phosphorylation and decreased expression of IFN and interferon-stimulated genes. A downregulation of cytoplasmic RIG-I levels occurred in cells undergoing a single-cycle infection with wild-type provirus BH10 but not in cells transfected with a protease-deficient provirus, BH10-PR−. Cellular fractionation and confocal microscopy studies revealed that RIG-I translocated from the cytosol to an insoluble fraction during the de novo HIV-1 infection of monocyte-derived macrophages, in the presence of PR. The loss of cytoplasmic RIG-I was prevented by the lysosomal inhibitor E64, suggesting that PR targets RIG-I to the lysosomes. This study reveals a novel PR-dependent mechanism employed by HIV-1 to counteract the early IFN response to viral RNA in infected cells

Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) verification and validation plan. version 1.

The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&amp;S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. To meet this objective, NEAMS Waste IPSC M&amp;S capabilities will be applied to challenging spatial domains, temporal domains, multiphysics couplings, and multiscale couplings. A strategic verification and validation (V&amp;V) goal is to establish evidence-based metrics for the level of confidence in M&amp;S codes and capabilities. Because it is economically impractical to apply the maximum V&amp;V rigor to each and every M&amp;S capability, M&amp;S capabilities will be ranked for their impact on the performance assessments of various components of the repository systems. Those M&amp;S capabilities with greater impact will require a greater level of confidence and a correspondingly greater investment in V&amp;V. This report includes five major components: (1) a background summary of the NEAMS Waste IPSC to emphasize M&amp;S challenges; (2) the conceptual foundation for verification, validation, and confidence assessment of NEAMS Waste IPSC M&amp;S capabilities; (3) specifications for the planned verification, validation, and confidence-assessment practices; (4) specifications for the planned evidence information management system; and (5) a path forward for the incremental implementation of this V&amp;V plan