Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “VALVES”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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

At least 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Oxide Removal from the InSb Plate Surface to Produce Lateral Spin Valves

Abstracts: The formation conditions of a smooth and oxide-free surface of InSb semiconductor with the purpose of fabricating lateral spin devices based on it are investigated. The dry etching rate by Ar ions of the surface of the crystalline faces (100) of InSb plates as well as a variation in their roughness depending on the power supplied to ion etching devices are investigated. The degree of oxidation of the semiconductor surface exposed to air after ion cleaning and annealing in molecular hydrogen are evaluated. Based on comparison of the efficiency of spin injection in devices formed with semiconductors subjected to various types of treatment, a conclusion is made about the parameters of optimal preparation of the surface of the InSb wafers for the fabrication of lateral spin devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Superconducting Spin Valves Based on Spiral Magnets

Abstract—Structures with spiral antiferromagnets are proposed as superconducting memory elements. The first structure consists of one superconducting layer and one magnetic layer with a spiral magnetization. The latter is a Josephson junction with spiral magnet as a weak link. The schematic diagram of switching between logic states in proposed structures is described.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Carbide Coatings for Nickel Alloys, Graphite and Carbon/Carbon Composites to be used in Fluoride Salt Valves

The focus of this research was concerned with developing materials technology that supports the evolution of Generation IV Advanced High Temperature Reactor (AHTR) concepts. Specifically, we investigate refractory carbide coatings for 1) nickel alloys, and 2) commercial carbon-carbon composites (CCCs). Numerous compelling reasons have driven us to focus on carbon and carbide materials. First, unlike metals, the strength and modulus of CCCs increase with rising temperature. Secondly, graphite and carbon composites have been proven effective for resisting highly corrosive fluoride melts such as molten cryolite [Na₃AlF₆] at ~1000°C in aluminum reduction cells. Thirdly, graphite and carbide materials exhibit extraordinary radiation damage tolerance and stability up to 2000°C. Finally, carbides are thermodynamically more stable in liquid fluoride salt than the corresponding metals (i.e. Cr and Zr) found in nickel based alloys.

36 MATERIALS SCIENCE↗
DOE OSTI2018

High-Efficiency VCR Engine with Variable Valve Actuation and New Supercharging Technology

Higher efficiency engines are needed for full size pickup trucks, utility vans and medium duty trucks. The primary objective of the program was to demonstrate the potential for improving the fuel economy of a full-size pickup truck by 40 percent while producing at least 281 horsepower. Commercialization requirements include: 1. High torque values at low vehicle speeds: This capability is needed for accelerating a heavy vehicle from a standstill, accelerating uphill, towing or any combination of these factors. 2. High power output: This capability is needed for accelerating onto a highway or passing at higher speeds. The vehicle may be carrying a heavy load, going uphill and/or towing. 3. Compliance with tailpipe emission regulations: This requirement must be met, and is difficult or costly to attain with diesel engine technology. 4. Low fuel consumption: This capability is needed both for reducing operating costs and to reduce greenhouse gas (GHG) vehicle emissions. The capability is also essential for complying with fuel economy standards. 5. Affordability: The powertrain cost must be consistent with mass market pricing. 6. Engine size and weight: The engine must fit in the existing engine bays. Engine weight must also be minimized. 7. Favorable noise vibration and harshness (NVH): The VCR must not present unique NVH challenges. The current program was successful. The efficiency target was achieved and the engine produced 300 horsepower.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

Reverse Initiation of the Reynolds RP-87 Detonator Resulting from Off-Normal Functioning of the Ultrafast Closure Valve System

A series of tests were executed to ensure complete UCV high explosive material consumption in the case of a system anomaly occurring — specifically a firing event where one or more RP-87 detonators do not function as a result of an arming and firing system problem or some other circumstance where a detonator does not function even though a firing signal is received at the bridgewire. A simplified linear array was utilized with 5 detonators per test firing only one detonator and maintaining the critical as-designed UCV dimensions and HE mass-to-volume ratios which can affect sympathetic initiation behavior. Tests were performed using both KTech Corporation's stated detonator gap of 0.060" as well as larger gaps to determine safety margin. The detonator's explosive contents were completely consumed in all cases where the gap was maintained within stated specifications. Only extreme gap conditions (0.30") indicated remaining explosive material. The mechanism by which the material is reacted does change with increasing gap however, transferring to a deflagration at larger gaps. All tests were performed at SNL/NM site 9930 in April 2013.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2022

Multi material/functionally graded wire arc additive manufacturing of high strength steel valves clad with nickel alloy 625 used for oil extraction

This Phase 1 technical collaboration project (ORNL/TM-2022/2683) began on August 1st, 2020 and concluded on July 31st, 2022. The collaboration partner Schlumberger is a large business enterprise assisting oil companies to extract oil from land and subsea cost competitively and safely. It is based in Houston, Texas USA. In this work as study of additive deposition of AWS EF100S-G and AWS ERNiCrMo-3 wires via wire-arc process was conducted.

36 MATERIALS SCIENCE↗