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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Observing Venus near the sun.

Discussion of the special requirements posed by telescopic observing near the sun. The sky brightness in the image plane must be kept to a minimum. Sunlight scattered from dust in the atmosphere or on the optical surfaces is the main difficulty, particularly at red and infrared wavelengths where Rayleigh scattering by air molecules is weak. Atmospheric dust is less troublesome at high altitudes and in dry climates than at low, humid sites. Excellent seeing is required, especially to get the thin crescent of Venus at inferior conjunction into the narrow slit of a spectrograph. The spectroscopic phase effect of Venus is discussed, and the procedures used to carry out observations near the sun are described in detail.

Young, A. T.↗
NASA NTRS1987

Processing of laser formed SiC powder

Processing research was undertaken to demonstrate that superior SiC characteristics could be achieved through the use of ideal constituent powders and careful post-synthesis processing steps. Initial research developed the means to produce approximately 1000 A uniform diameter, nonagglomerated, spherical, high purity SiC powders. Accomplishing this goal required major revision of the particle formation and growth model from one based on classical nucleation and growth to one based on collision and coalescence of Si particles followed by their carburization. Dispersions based on pure organic solvents as well as steric stabilization were investigated. Test parts were made by the colloidal pressing technique; both liquid filtration and consolidation (rearrangement) stages were modeled. Green densities corresponding to a random close packed structure were achieved. After drying, parts were densified at temperatures ranging from 1800 to 2100 C. This research program accomplished all of its major objectives. Superior microstructures and properties were attained by using powders having ideal characteristics and special post-synthesis processing procedures.

Haggerty, J. S.↗
DOE OSTI2016

Free-standing Liquids in a Resin Disposal Container - How Unidentified Legacy Issues and Decisions Can Affect Current Radwaste Processing Activities - 16605

On Monday, October 27, 2014 a radwaste and transportation specialist was informed that a condensate filter demineralizer (CFD) radwaste disposal container exceeded the radioactive waste disposal facility free-standing liquid requirement for acceptance for disposal (limit is 0.5% of waste volume or 5.6 gallons); 8.5 gallons was measured). As a result, on October 28, the plant was informed that our disposal site use permit was suspended, pending a point-of-origin inspection by the agreement state regulatory authority. This paper details the investigation conducted to identify causes, especially legacy issues one may not necessarily identify, and documents corrective actions taken to assure similar issues are not repeated. Actions taken to prevent recurrence have been successful. The five containers shipped, including 14-033, were verified dewatered and dried to comply with the disposal facility waste acceptance criteria. Although discoloration is viewed in the dewatering sight glass, milky color has not been viewed and the dewatering process has continued. Isolation of the lowest set of dewatering filter laterals for use at the end of the dewatering process has worked well and use of the dewatering verification filters has provided evidence that each CRF resin liner was successfully dewatered and dried. To date, 37 CFD liners have been successfully dewatered, dried, verified, transported to the disposal facility, and buried without incident. If similar issues are encountered, you should keep an open mind regarding causes including, but not limited to discussions with your vendor and conduct a search of past procedure revisions to gain additional insight regarding program/procedure changes and how they could have an effect on issues, which occur today.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2000

BOREAS RSS-15 SIR-C and Landsat TM Biomass and Landcover Maps of the NSA

As part of BOREAS, the RSS-15 team conducted an investigation using SIR-C, X-SAR, and Landsat TM data for estimating total above-ground dry biomass for the SSA and NSA modeling grids and component biomass for the SSA. Relationships of backscatter to total biomass and total biomass to foliage, branch, and bole biomass were used to estimate biomass density across the landscape. The procedure involved image classification with SAR and Landsat TM data and development of simple mapping techniques using combinations of SAR channels. For the SSA, the SIR-C data used were acquired on 06-Oct-1994, and the Landsat TM data used were acquired on 02-Sep-1995. The maps of the NSA were developed from SIR-C data acquired on 13-Apr-1994. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Hall, Forrest G.↗
DOE OSTI2022

National Ignition Facility. Facility and Infrastructure Systems Maintenance Plan

Ensuring the reliability of the NIF, including its support systems, laser systems, target diagnostic systems, and utilities, is essential to the availability of the NIF in its support of NNSA missions. NIF is a key capability in the DOE Stockpile Stewardship Program and supports high energy physics experiments for nuclear weapons, energy, and astrophysics applications. High system reliability provides opportunities for shots and scientific discoveries with opportunities to enhance and upgrade capabilities. This Maintenance Plan (MP) identifies the policies and procedures used to perform and support asset management of the NIF Facility and Infrastructure Systems (FInS), NIF Lasers & Alignment (LASE), NIF Target Experimental Operations (TOPS), NIF Target Area Science and Engineering (TASE), and NIF&PS Control Systems (NCS). The FInS systems include the facility, HVAC, contamination control, beampath, and Line Replaceable Units (LRUs) as well as utilities which create the beampath environments, such as vacuum, argon, or clean dry air. The LASE systems are Programmatic systems which include laser diagnostics, alignment, power conditioning, pulsed power, and input laser systems. The TOPS and TASE systems are also Programmatic systems which include target and diagnostic delivery systems and positioners, many different insertable and fixed target diagnostics, and cryogenic and target gas fill systems. Finally, the NCS systems include both software and hardware for industrial and shot operation control systems. Policies governing administrative and operational practices related to maintenance of FInS, LASE, TOPS, TASE, and NCS systems are described in this plan. In addition, the plan provides processes and procedures for managing, tracking, and documenting the work. This document, the NIF Operations Management Plan, NIF-5020544 (Ref. 1), and NIF Shot Operations Plan, NIF-5018506 (Ref. 2), together satisfy the requirements of the Conduct of Operations. Duties, responsibilities, and reporting requirements of the various positions associated with FInS, LASE, and TOPS maintenance are detailed in this plan. The FInS systems include both Real Property systems with asset management requirements specified in DOE Order 430.1C (Ref. 3) and Programmatic systems. In addition, for FInS, there is a list of the System Level Maintenance Plans (SLMPs) in NIF-1007419198 (Ref. 4) which provide the system descriptions and maintenance plan and schedule. In addition, the list includes the Reliability Centered Maintenance (RCM) and Experience Centered Maintenance (ECM) evaluations that have been performed for applicable FInS systems as well as reliability criticality per Section 3.5. The -AM version of the NIF Maintenance Plan focuses on the reliability program for FInS, LASE, TOPS, TASE, and NCS within the context of the overall NIF Reliability, Availability, and Maintainability (RAM) program and incorporates changes since the -AL version from August 2011 and has been updated to be fully consistent with the updates to Ref. 1. It also includes asset management considerations, updates to the Work Order (WO) process within the NIF Computerized Maintenance Management System (CMMS) which is EAM infor® System Maintenance and Reliability Tracking (SMaRT) (Ref. 5), and updates to metrics and key performance indicators (KPIs).

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2012

Addressing Facility Needs for Concrete Assessment Using Ultrasonic Testing: Mid-year Report

The UFD Gap Analysis to Support Extended Storage of Used Nuclear Fuel (June 30, 2011) emphasizes the need for the development of monitoring techniques and technologies for dry storage cask materials. A high priority is given to the development of 'systems for early detection of confinement boundary degradation.' This requires both new techniques for monitoring and inspection, as well as new measurable parameters to quantify mechanical degradation. The use of Nonlinear Elastic Wave Spectroscopy (NEWS) has been shown to provide sensitive parameters correlating to mechanical degradation in a wide variety of materials. Herein we report upon recent research performed to address the high priority of concrete degradation using a selection of these techniques and compare to a ASTM standard ultrasonic technique. Also reported are the near term plans to continue this research in the remaining FY and into the coming years. This research was conducted at Los Alamos National Laboratory (LANL) in the Acoustics Lab of the Geophysics group in the Earth and Environmental Sciences division, and in collaboration with the Laboratory for Nondestructive Evaluation at the University of the Mediterranean (Aix en Provence, France) and the Electrical Power Research Institute (EPRI). The objective of this research project was to determine the feasibility of using an NDE technique based on non-linear ultrasound for determining the depth and degree of microcracking in the near surface of concrete and to assess the degree of sensitivity of such technique. This objective is reached by the means of combining linear and nonlinear measurements, associated with numerical simulation. We first study the global effect of thermal damage on concrete's linear and nonlinear properties by resonance inspection techniques. We show that standard pulse wave speed techniques are not relevant to extract mechanical properties of concrete. The high sensitivity of measured nonlinearity is shown and serves as a validation tool for the rest of the study, i.e., probing the material nonlinearity at various depths through the use of Time Reversal Elastic Nonlinearity Diagnostic (TREND). The basic idea of probing the material nonlinearity at various depths by changing the frequency is validated by exhibiting a similar trend as nonlinear resonance measurements. We address at the end of this report, the potentialities of applying these procedures to real concrete structures.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Direct current injection and thermocapillary flow for purification of aligned arrays of single-walled carbon nanotubes

Aligned arrays of semiconducting single-walled carbon nanotubes (s-SWNTs) represent ideal configurations for use of this class of material in high performance electronics. Development of means for removing the metallic SWNTs (m-SWNTs) in as-grown arrays represents an essential challenge. Here, we introduce a simple scheme that achieves this type of purification using direct, selective current injection through interdigitated electrodes into the m-SWNTs, to allow their complete removal using processes of thermocapillarity and dry etching. Experiments and numerical simulations establish the fundamental aspects that lead to selectivity in this process, thereby setting design rules for optimization. Single-step purification of arrays that include thousands of SWNTs demonstrates the effectiveness and simplicity of the procedures. The result is a practical route to large-area aligned arrays of purely s-SWNTs with low-cost experimental setups.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1976

The reactions of O(ID) and OH with CH3OH, oxidation of the HCO radial, and the photochemical oxidation of formaldehyde

An experimental, laboratory study of the various photochemical reactions that can occur in the mesosphere and stratosphere is presented. N2O was photolyzed at 2139 A in the presence of CH3OH and CO. The O(id) produced in the photolysis reacted with CH3OH to produce OH radicals, and thus the reactions of both O(id) and OH were able to be studied. Also considered was the oxidation of the HCO radical. Mixtures of Cl2, O2, H2CO, and sometimes N2 or He were irradiated at 3660 A at several temperatures to photodecompose the Cl2. The photochemical oxidation of formaldehyde was studied as follows: formaldehyde in the presence of N2 and/or O2 (usually dry air) was photolyzed with a medium pressure Hg lamp used in conjunction with various filters which transmit different relative amounts of Hg lines from 2894 A to 3660 A. Results are presented and discussed, along with a description of experimental procedures and apparatus, and chemical reaction kinetics.

Osif, T. L.↗
NASA NTRS1981

Development of advanced lightweight containment systems

Parametric type data were obtained on advanced lightweight containment systems. These data were used to generate design methods and procedures necessary for the successful development of such systems. The methods were then demonstrated through the design of a lightweight containment system for a CF6 size engine. The containment concept evaluated consisted basically of a lightweight structural sandwich shell wrapped with dry Kevlar cloth. The initial testing was directed towards the determination of the amount of Kevlar required to result in threshold containment for a specific set of test conditions. A relationship was then developed between the thickness required and the energy of the released blade so that the data could be used to design for conditions other than those tested.

Stotler, C.↗
DOE OSTI2018

Fabrication of Core–Shell Nanotube Array for Artificial Photosynthesis Featuring an Ultrathin Composite Separation Membrane

We report macroscale arrays of cobalt oxide-silica core-shell nanotubes with high aspect ratio and ultrathin walls of less than 20 nm have been fabricated. The silica shells feature embedded oligo-para(phenylenevinylene) molecules for charge transport across the insulating silica layer, which is tightly controlled by their electronic properties. The assembly is based on the use of a sacrificial Si nanorod array template combined with atomic layer deposition, covalent anchoring of organic wire molecules, and dry cryo-etching. High-resolution TEM imaging of samples prepared by microtome affords structural details of single core-shell nanotubes. The integrity of silica-embedded organic wire molecules exposed to atomic layer deposition, thermal treatment, and harsh etching procedures is demonstrated by grazing angle ATR FT-IR, FT-Raman, and XPS spectroscopy. The inorganic oxide-based core-shell nanotubes with ultrathin gas-impermeable, proton-conducting silica shells functionalized by molecular wires enable complete nanoscale photosynthetic units for CO 2 reduction by H 2 O under membrane separation. Arrays of massive numbers of such core-shell nanotube units afford a design that extends the separation of the incompatible H 2 O oxidation and CO 2 reduction catalysis environments across the continuum of length scales from nanometers to centimeters.

molecular wires↗
NASA NTRS1972

Spacecraft sterilization.

Spacecraft sterilization is a vital factor in projects for the successful biological exploration of other planets. The microorganisms of major concern are the fungi and bacteria. Sterilization procedures are oriented toward the destruction of bacterial spores. Gaseous sterilants are examined, giving attention to formaldehyde, beta-propiolactone, ethylene oxide, and the chemistry of the bactericidal action of sterilants. Radiation has been seriously considered as another method for spacecraft sterilization. Dry heat sterilization is discussed together with the effects of ethylene oxide decontamination and dry heat sterilization on materials.

Kalfayan, S. H.↗
NASA NTRS2002

Isocyanate Cross-Linked Silica: Structurally Strong Aerogels

Molecular-level synergism between the silica nanoparticles of pre-formed monoliths and molecular cross-linkers inverts the relative host-guest roles in glass-polymer composites, leading to new strong low-density materials. Attempts to load gels with variable amounts of polyurethane precursors such as di-ISO and diol end-capped polybutylene adipate followed by heat treatment, washing, and supercritical drying led to opaque materials, somewhat stronger than silica but still quite brittle and much inferior to the materials described above. Direct mixing of a diisocyanate and an alcohol-free sol has been attempted recently by Yim et al. Reportedly, that procedure leads to week-long gelation times and requires an at least equally long aging period. In our attempt to add various amounts of di-ISO in a base-catalyzed sol in PC, we also noticed a week-long gelation time. The resulting aerogels were translucent but no less brittle than native silica. According to more recent studies, if propylene carbonate is replaced with acetone, it leads not only to shorter processing times, but also to much stronger gels that can tolerate loads in excess of 40 kg in the arrangement presented. We attribute that behavior to the lower viscosity of acetone, that allows faster diffusion of the di-ISO solution within the pores before di-ISO has time to react with the surface of silica. Further studies are underway to vary the chemical identity of the diisocyanate, as well as the composition and density of silica.

Leventis, Nicholas↗
NASA NTRS2009

Hydrogen Fuel System Design Trades for High-Altitude Long-Endurance Remotely- Operated Aircraft

Preliminary design trades are presented for liquid hydrogen fuel systems for remotely-operated, high-altitude aircraft that accommodate three different propulsion options: internal combustion engines, and electric motors powered by either polymer electrolyte membrane fuel cells or solid oxide fuel cells. Mission goal is sustained cruise at 60,000 ft altitude, with duration-aloft a key parameter. The subject aircraft specifies an engine power of 143 to 148 hp, gross liftoff weight of 9270 to 9450 lb, payload of 440 lb, and a hydrogen fuel capacity of 2650 to 2755 lb stored in two spherical tanks (8.5 ft inside diameter), each with a dry mass goal of 316 lb. Hydrogen schematics for all three propulsion options are provided. Each employs vacuum-jacketed tanks with multilayer insulation, augmented with a helium pressurant system, and using electric motor driven hydrogen pumps. The most significant schematic differences involve the heat exchangers and hydrogen reclamation equipment. Heat balances indicate that mission durations of 10 to 16 days appear achievable. The dry mass for the hydrogen system is estimated to be 1900 lb, including 645 lb for each tank. This tank mass is roughly twice that of the advanced tanks assumed in the initial conceptual vehicle. Control strategies are not addressed, nor are procedures for filling and draining the tanks.

Millis, Marc G.↗
DOE OSTI2012

Ex vivo evaluation of a coherent normalization procedure to quantify in vivo finger strontium XRS measurements

Purpose: Energy dispersive x-ray fluorescence spectroscopy (XRS) measurements were performed on human cadaver index fingers to measure bone strontium content in the presence of intact overlying soft-tissue. This work assesses the feasibility of applying a normalization procedure including soft-tissue correction of x-ray absorption as a means to quantify an ex vivo bone strontium XRS measurement. Methods: Bone strontium measurements were made using an excitation-detection system incorporating an {sup 125}I x-ray excitation source and an Ortec registered Ametek-AMT Si(Li) detector in 180 deg. backscatter geometry. Spectral processing was accomplished using an in-house nonlinear least-squares Marquardt fitting routine. Bone strontium was quantified using an egs5 Monte Carlo based x-ray soft-tissue correction algorithm in conjunction with the normalization of strontium x-rays to the coherent scatter peaks of 35.5 keV {sup 125}I {gamma}-rays. Results: Comparison of tissue intact and bare bone finger XRS measurement quantification attempts revealed an overall discrepancy of 18.6% that is attributed primarily to the significant contribution of soft-tissue to coherent scatter of 35.5 keV source {gamma}-rays and to a lesser degree, inconsistencies with the simulated tissue correction model. Work toward the beginnings of an experimentally derived tissue correction model, as a means to validate the simulated model, have been reported. Two observations hinted at a systematic inflation of the observed K{beta} peak area. First, strontium concentrations estimated by K{alpha} peak areas were less than the K{beta} peak areas by 28.6% (p < 0.0001) and 10.5% (p < 0.001) for tissue intact and bare bone measurements, respectively. Second, the K{alpha}:K{beta} x-ray average ratios between tissue corrected (3.61 {+-} 0.55) and bare bone predicted (4.4 {+-} 0.4) did not agree (p < 0.0001) and pointed to shortcomings with the current processing treatment of strontium K x-ray peak area extraction. Through finger bone XRS measurements, bone strontium concentration in the Caucasian population was estimated at 95 {+-} 15 {mu}g Sr/g dry bone. Conclusions: The discrepancies observed: between quantification attempts of tissue corrected and bare bone measurements, the inflated estimates of K{beta} relative to K{alpha} peak concentrations and between observed and expected K{alpha}:K{beta} ratios, have indicated that shortcomings with the bone strontium coherent normalization and tissue correction procedure exist. Coherent scatter contribution of soft-tissue overlying bone, tissue correction model limitations, and spectra processing issues are all mentioned as sources of observed discrepancies.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Ultra-selective membrane composed of charge-stabilized fixed carrier and amino acid-based ionic liquid mobile carrier for highly efficient carbon capture

Membrane technology has been extensively studied for CO 2 capture applications, especially for flue gas sources. In the past decades, facilitated transport membranes (FTMs) have made breakthroughs overcoming the permeance-selectivity trade-off upper bound restricting traditional CO 2 separation membranes, but are still facing challenges towards practical applications, including limited performance, such as insufficient CO 2 /N 2 selectivity to achieve 95 % CO 2 dry-base purity by one step separation, and long-term stability. Herein, we designed and fabricated a novel FTM structure containing an ionic liquid (1-ethyl-3-methylimidazolium aminoacetate, [Emim][Gly]) as mobile CO 2 -carrier and a polymeric amine (polyethyleneimine, PEI) as fixed CO 2 -carrier. In this study, the fixed carrier is confined within a carbon nanotube (CNT) framework of 230 nm thickness via electrostatic forces adjusted by a polyelectrolyte (polystyrene sulfonate, PSS), while the mobile carrier diffuses freely within the CNT framework. After optimization of the membrane recipe and spray-coating fabrication procedure, following our previous work, the resulting CNT-PSS-PEI ~ IL membranes demonstrated an ultra-high CO 2 /N 2 selectivity up to 1,000 with CO 2 permeance up to 2,400 GPU (Gas Permeation Unit, 1 GPU = 3.348 × 10 -10 mol·s -1 ·m -2 ·Pa -1 ) under vacuum operation condition. Furthermore, one 100-cm 2 flat sheet membrane sample was prepared and exhibited one-stage CO 2 enrichment from 15 % to 95 % purity (dry-base) for the first time amongst all reported CO 2 separation membranes. The membrane retained a stable performance over 50-h operation period under vacuum condition. The extraordinary CO 2 separation performance illustrates the great potential of the CNT-PSS-PEI ~ IL membranes for flue gas carbon capture application.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1993

Humidity effects on soluble core mechanical and thermal properties (polyvinyl alcohol/microballoon composite) type CG extendospheres, volume 2

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties under Contract No. 100345. This report describes test results procedures employed, and any unusual occurrences or specific observations associated with this test program. The primary objective of this work was to determine if cured soluble core filler material regains its tensile and compressive strength after exposure to high humidity conditions and following a drying cycle. Secondary objectives include measurements of tensile and compressive modulus, and Poisson's ratio, and coefficient of thermal expansion (CTE) for various moisture exposure states. A third objective was to compare the mechanical and thermal properties of the composite using 'SG' and 'CG' type extendospheres. The proposed facility for the manufacture of soluble cores at the Yellow Creek site incorporates no capability for the control of humidity. Recent physical property tests performed with the soluble core filler material showed that prolonged exposure to high humidity significantly degradates in strength. The purpose of these tests is to determine if the product, process or facility designs require modification to avoid imparting a high risk condition to the ASRM.

Source record↗
NASA NTRS2001

Use of Capillaries for Macromolecular Crystallization in a Cryogenic Dewar

The Enhanced Gaseous Nitrogen (EGN) Dewar is a cryogenic dry shipper with a sealed cylinder inserted inside along with a temperature-monitoring device, and is intended for macromolecular crystallization experiments on the International Space Station. Within the Dewar, each crystallization experiment is contained as a solution within a plastic capillary. The standard procedure for loading samples in these tubes has involved rapid freezing of the precipitant and biomolecule solution directly in liquid nitrogen; this method, however, often results in uncontrolled formation of air voids. These air pockets, or bubbles, then can lead to irreproducible crystallization results. A novel protocol has been developed to prevent formation of bubbles, and this has been tested in the laboratory as well as aboard the International Space Station during a 42-day long mission of July/August of 2001. Furthermore, gain or loss of mass from solutions within the capillaries revealed that mass transport amongst separated tubes occurred, and that this mass transport was determined by the hygroscopic character of a solution contained in any given tube. The sample volume and the surface area of the plastic capillary tube also related to the observed mass transport.

Ciszak, Ewa↗
NASA NTRS2002

Use of Capillaries for Macromolecular Crystallization in a Cryogenic Dewar

The enhanced gaseous nitrogen (EGN) dewar is a cryogenic dry shipper with a sealed cylinder inserted inside along with a temperature monitoring device, and is intended for macromolecular crystallization experiments on the International Space Station. Within the dewar, each crystallization experiment is contained as a solution within a plastic capillary tube. The standard procedure for loading samples in these tubes has involved rapid freezing of the precipitant and biomolecular solution, e.g., protein, directly in liquid nitrogen; this method, however, often resulted in uncontrolled formation of air voids, These air pockets, or bubbles, can lead to irreproducible crystallization results. A novel protocol has been developed to prevent formation of bubbles, and this has been tested in the laboratory as well as aboard the International Space Station during a 42-day long mission of July/August 2001. The gain or loss of mass from solutions within the plastic capillaries revealed that mass transport occurred among separated tubes, and that this mass transport was dependent upon the hygroscopic character of the solution contained in any given tube. The surface area of the plastic capillary tube also related to the observed mass transport. Furthermore, the decreased mass of solutions of-protein correlated to observed formation of protein crystals.

Ciszak, Ewa↗