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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 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Reverberation Time Measurements in the NASA Langley Exterior Effects Room (EER)

One-third octave band background noise and reverberation time measurements were conducted in the Exterior Effect Room (EER) at the NASA Langley Research Center. The related overall acoustic absorption of the room was calculated. The acoustic field in the room was characterized. Reverberation time measurements were performed using the integrated impulse response method. The results were compared with independent measurements using the interrupted noise reverberation time method and different instrumentation. Reasonable agreement was obtained between the reverberation times of the two methods.

Grosveld, Ferdinand W.↗
NASA NTRS2013

'How To' Clean Room Video

One of the projects that I am completing this summer is a Launch Services Program intern 'How to' set up a clean room informational video. The purpose of this video is to go along with a clean room kit that can be checked out by employees at the Kennedy Space Center and to be taken to classrooms to help educate students and intrigue them about NASA. The video will include 'how to' set up and operate a clean room at NASA. This is a group project so we will be acting as a team and contributing our own input and ideas. We will include various activities for children in classrooms to complete, while learning and having fun. Activities that we will explain and film include: helping children understand the proper way to wear a bunny suit, a brief background on cleanrooms, and the importance of maintaining the cleanliness of a space craft. This project will be shown to LSP management and co-workers; we will be presenting the video once it is completed.

McCarty, Kaley Corinne↗
NASA NTRS2018

Microbial Ecology of NASA Curation Clean Rooms

Clean room standards like ISO 14644 used for facilities that construct spacecraft and store returned samples do not explicitly account for microbial contamination. While there are associated ISO standards for monitoring and controlling bio-contamination in clean rooms it is not always standard practice to do so. The NASA Astromaterials Acquisition and Curation Office maintains seven separate clean labs for storing extraterrestrial samples from the Moon, meteorites, cosmic dust, asteroids, comets, solar wind particles, and microparticle impact samples. These labs are routinely monitored for particulate and trace metal contamination. However, the sample collections are either non-sterile at the time of collection (e.g., meteorites) or are no longer being used to address scientific questions that could be affected by non-sterile conditions (e.g., Lunar samples). Outside of isolated studies there has not been a systematic, longitudinal characterization of the microbial ecology of NASA curation clean rooms. In accordance with the advanced curation initiative, and to prepare for future sample return missions, we have initiated a routine microbiological monitoring program in the Antarctic Meteorite Lab. This monitoring program will be used to determine what microbes are capable of surviving in these oligotrophic environments and whether or not they are capable of altering the sample collections in any significant manner. Repeat sampling will allow us to understand how routine use of these labs affects the microbial ecology over time.

Regberg, A. B.↗
DOE OSTI2014

Microstructure evolution in Xe-irradiated UO2 at room temperature

In situ Transmission Electron Microscopy was conducted for single crystal UO2 to understand the microstructure evolution during 300 keV Xe irradiation at room temperature. The dislocation microstructure evolution was shown to occur as nucleation and growth of dislocation loops at low irradiation doses, followed by transformation to extended dislocation segments and tangles at higher doses. Xe bubbles with dimensions of 1-2 nm were observed after room-temperature irradiation. Electron Energy Loss Spectroscopy indicated that UO2 remained stoichiometric under room temperature Xe irradiation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2011

Grain size modulation on BaTiO{sub 3} nanoparticles synthesized at room temperature

A new method is developed to synthesize massive BaTiO{sub 3} nanoparticles directly at room temperature. With this method, the synthesis efficiency is improved and mass preparation can be realized. Also, the grain size of the as-prepared nanoparticles can be modulated from several nanometers to 40 nm through proper selection of the content of water and the alkanol chain length of the dispersant. It was found that smaller water content and a larger alkanol chain length of the dispersant will lead to a finer grain size. The mechanisms of the grain size modulation of BaTiO{sub 3} nanoparticles are also discussed. - graphical abstract: This paper offers a direct facile approach to BaTiO{sub 3} nanoparticles at room temperature with a large quantity. The grain size can be modulated purposefully. Highlights: > Room temperature synthesis of BaTiO{sub 3} nanoparticles with large scale is realized. > Grain size can be controlled purposefully. > Effect of content of water on crystallization of BaTiO{sub 3} is revealed. > Influence of alkanol chain length of the dispersant is found.

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

Migration of Older to New Digital Control Systems in Nuclear Power Plant Main Control Rooms

The United States (U.S.) Department of Energy (DOE) Office of Nuclear Energy (NE) has the primary mission to advance nuclear power by resolving socio-technical issues through research and development (R&D). One DOE-NE activity supporting this mission is the Light Water Reactor Sustainability (LWRS) program. LWRS has the overall objective to sustain the operation of existing commercial nuclear power plants (NPPs) through conducting R&D across multiple “pathways,” or R&D focus areas. The Advanced Instrumentation, Information, and Control (II&C) Systems Technologies pathway conducts targeted R&D to address aging and reliability concerns with the legacy instrumentation and control (I&C) and related information systems in operating U.S. NPPs. This work involves (1) ensuring that legacy analog II&C systems are not life-limiting issues for the LWR fleet, and (2) implementing digital II&C technology in a manner that enables broad innovation and business improvement in the NPP operating model. Under the LWRS Advanced II&C pathway, Human Factors experts at Idaho National Laboratory (INL) have been conducting R&D in support of NPP main control room (MCR) modernization activities. Work in prior years has focused on migrating analog I&C systems to new digital I&C systems (). In fiscal year 2016 (FY16), one new focus area for this research is migrating older digital I&C systems to new and advanced digital I&C systems. This report summarizes a plan for conducting a digital-to-digital migration of a legacy digital I&C system to a new digital I&C system in support of control room modernization activities.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

P-Type Transparent Cu-Alloyed ZnS Deposited at Room Temperature

All transparent conducting materials (TCMs) of technological practicality are n-type; the inferior conductivity of p-type TCMs has limited their adoption. Additionally, many relatively high-performing p-type TCMs require synthesis temperatures > 400 °C. Here, room-temperature pulsed laser deposition of copper-alloyed zinc sulfide (Cu x Zn 1- x S) thin films (0 ≤ x ≤ 0.75) is reported. For 0.09 ≤ x ≤ 0.35, Cu x Zn 1- x S has high p-type conductivity, up to 42 S cm -1 at x = 0.30, with an optical band gap tunable from ≈3.0–3.3 eV and transparency, averaged over the visible, of 50%–71% for 200–250 nm thick films. In this range, synchrotron X-ray and electron diffraction reveal a nanocrystalline ZnS structure. Secondary crystalline Cu y S phases are not observed, and at higher Cu concentrations, x > 0.45, films are amorphous and poorly conducting. Furthermore, within the TCM regime, the conductivity is temperature independent, indicating degenerate hole conduction. A decrease in lattice parameter with Cu content suggests that the hole conduction is due to substitutional incorporation of Cu onto Zn sites. This hole-conducting phase is embedded in a less conducting amorphous Cu y S, which dominates at higher Cu concentrations. Finally, the combination of high hole conductivity and optical transparency for the peak conductivity Cu x Zn 1- x S films is among the best reported to date for a room temperature deposited p-type TCM.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Ergonomic Safety and Health Activities to Support Commercial Nuclear Power Plant Control Room Modernization in the United States

Affordable, abundant, and reliable electricity generation is essential to fueling a nation’s robust and globally competitive economy. In the United States (U.S.), commercial nuclear power plants (NPPs) account for approximately 19% of reliable and cost-competitive baseload electricity generation. Other technologies that reduce reliance on fossil fuels and provide baseload electricity cost-competitively at a national scale are still under development. Thus, without suitable replacements for nuclear power, the generating capacity of nuclear energy in the U.S. must be continued through the safe and efficient operation of commercial NPPs. The U.S. De-partment of Energy’s (DOE) Light Water Reactor Sustainability (LWRS) research and development (R&D) program provides the technical bases for the long-term, safe, and economical operation of NPPs. One area in the LWRS program is the Plant Modernization pathway, which includes human factors R&D, human factors engineering (HFE), and ergonomics to enable the modernization of the instrumentation and control (I&C) technologies in NPP main control rooms (MCRs). DOE researchers, including ergonomics specialists at Idaho National Laboratory (INL) have collaborated with nu-merous commercial NPP utilities over the last few years on control room modernization. This paper summarizes recent ergonomics safety and health R&D and HFE performed in collaboration with a U.S. commercial utility to modernize their NPP MCRs.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2018

Trimethyl phosphate based neutral ligand room temperature ionic liquids for electrodeposition of rare earth elements

In this communication, a new class of task-specific ionic liquids (ILs) with cationic rare earth elements (REEs) is reported. These novel ILs have a wide electrochemical window of about 6 V, enabling direct electrodeposition of REE metals at room temperature. The ILs were prepared by dissolving bis(trifluoromethane)sulfonimide (NTf 2 – ) based rare earth salts (Ln(NTf 2 ) 3 ) (Ln:Lanthanide) in trimethyl phosphate (TMP) neutral ligand. Specifically, four REEs (Nd, Dy, Gd, and Pr) have been investigated in TMP based IL systems. All four metals were successfully deposited at room temperature. In conclusion, this demonstrates the applicability of the IL systems for electrodeposition of a wide range of REEs, which opens a new avenue of research for the quest to supplant high temperature molten salt systems for rare earth deposition.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Room-Temperature Magnetic Order in Air-Stable Ultrathin Iron Oxide

Manual assembly of atomically thin materials into heterostructures with desirable electronic properties is an approach that holds great promise. Despite the rapid expansion of the family of ultrathin materials, stackable and stable ferro/ferri magnets that are functional at room temperature are still out of reach. We report the growth of air-stable, transferable ultrathin iron oxide crystals that exhibit magnetic order at room temperature. These crystals require no passivation and can be prepared by scalable and cost-effective chemical vapor deposition. We demonstrate that the bonding between iron oxide and its growth substrate is van der Waals-like, enabling us to remove the crystals from their growth substrate and prepare iron oxide/graphene heterostructures.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Solution-Processed Ultrafast, Room-Temperature Single-Photon Source at 1550 nm

Single photons are cornerstones of quantum technologies. The need for an ultrafast, bright, and stable photon source emitting in the telecom-band at ∼1550 nm, ideally operating at room temperature, has resulted in a decades-long quest. However, to date, telecom sources are hampered by inherently long radiative lifetimes that severely limit brightness and speed, material instability, or the need for cryogenic operation. Here, in this study, stable colloidal PbS/CdS quantum dots emitting at 1550 nm (C-band) or 1350 nm (O-band) are embedded in a solution-synthesized nanoparticle-on-mirror cavity. Single cavity-coupled quantum dots experience extreme Purcell factors up to 10,700, resulting in ultrafast emission lifetimes of 65 ps, along with near-complete blinking suppression. As a result, 12 million single photons are emitted per second affording a single photon source at 1550 nm that is more than two orders of magnitude brighter than previously possible at room-temperature. These telecom-band single photon sources are solution-processable and lithography-free and may leverage mature colloidal fabrication technologies for future quantum applications.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Revealing protonation states and tracking substrate in serine hydroxymethyltransferase with room-temperature X-ray and neutron crystallography

Pyridoxal 5’-phosphate (PLP)-dependent enzymes utilize a vitamin B 6 -derived cofactor to perform a myriad of chemical transformations on amino acids and other small molecules. Some PLP-dependent enzymes, such as serine hydroxymethyltransferase (SHMT), are promising drug targets for the design of small-molecule antimicrobials and anticancer therapeutics, while others have been used to synthesize pharmaceutical building blocks. Understanding PLP-dependent catalysis and the reaction specificity is crucial to advance structure-assisted drug design and enzyme engineering. Here we report the direct determination of the protonation states in the active site of Thermus thermophilus SHMT (TthSHMT) in the internal aldimine state using room-temperature joint X-ray/neutron crystallography. Conserved active site architecture of the model enzyme TthSHMT and of human mitochondrial SHMT (hSHMT2) were compared by obtaining a room-temperature X-ray structure of hSHMT2, suggesting identical protonation states in the human enzyme. The amino acid substrate serine pathway through the TthSHMT active site cavity was tracked, revealing the peripheral and cationic binding sites that correspond to the pre-Michaelis and pseudo-Michaelis complexes, respectively. At the peripheral binding site, the substrate is bound in the zwitterionic form. By analyzing the observed protonation states, Glu53, but not His residues, is proposed as the general base catalyst, orchestrating the retro-aldol transformation of L-serine into glycine.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Spin-Induced Polarizations and Nonreciprocal Directional Dichroism of the Room-Temperature Multiferroic BiFeO 3

A microscopic model for the room-temperature multiferroic BiFeO 3 that includes two Dzyaloshinskii-Moriya interactions and single-ion anisotropy along the ferroelectric polarization predicts both the zero-field spectroscopic modes as well as their splitting and evolution in a magnetic field. Due to simultaneously broken time-reversal and spatial-inversion symmetries, the absorption of light changes as the magnetic field or the direction of light propagation is reversed. We discuss three physical mechanisms that may contribute to this absorption asymmetry known as directional dichroism: the spin current, magnetostriction, and single-ion anisotropy. We conclude that the directional dichroism in BiFeO 3 is dominated by the spin-current polarization and is insensitive to the magnetostriction and easy-axis anisotropy. With three independent spin-current parameters, our model accurately describes the directional dichroism observed for magnetic field along [1, -1, 0]. Since some modes are almost transparent to light traveling in one direction but opaque for light traveling in the opposite direction, BiFeO 3 can be used as a room-temperature optical diode at certain frequencies in the GHz to THz range. This work demonstrates that an analysis of the directional dichroism spectra based on an effective spin model supplemented by first-principles calculations can produce a quantitative microscopic theory of the magnetoelectric couplings in multiferroic materials.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Optical diode effect at spin-wave excitations in the room-temperature multiferroic BiFeO 3 .

The ability to read and write a magnetic state current-free by an electric voltage would provide a huge technological advantage. Dynamic or optical ME effects are equally interesting, because they give rise to unidirectional light propagation as recently observed in low-temperature multiferroics. This phenomenon, if realized at room temperature, would allow the development of optical diodes which transmit unpolarized light in one, but not in the opposite, direction. Here, we report strong unidirectional transmission in the room-temperature multiferroic BiFeO 3 over the gigahertz-terahertz frequency range. The supporting theory attributes the observed unidirectional transmission to the spin-current-driven dynamic ME effect. Our findings are an important step toward the realization of optical diodes, supplemented by the ability to switch the transmission direction with a magnetic or electric field.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Human factors design, verification, and validation for two types of control room upgrades at a nuclear power plant

This paper describes the NUREG-0711 based human factors engineering (HFE) phases and associated elements required to support design, verification and validation (V&V), and implementation of a new plant process computer (PPC) and turbine control system (TCS) at a representative nuclear power plant. This paper reviews ways to take a human-system interface (HSI) specification and use it when migrating legacy PPC displays or designing displays with new functionality. These displays undergo iterative usability testing during the design phase and then undergo an integrated system validation (ISV) in a full scope control room training simulator. Following the successful demonstration of operator performance with the systems during the ISV, the new system is implemented at the plant, first in the training simulator and then in the main control room.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2012

Demonstration of Intelligent Control and Fan Improvements in Computer Room Air Handlers

This report documents a demonstration of the energy-efficiency improvement provided by a new control system for computer room air handling devices. It also analyzes measured and reported air handling device fan power associated with changing the fan type. A 135,000 square foot commercial data center was used for the demonstration. All air handling units were upgraded with improved efficiency fans, and a control system that automatically adjusts the fan speed for the air handling units was added. Power measurements were collected for a baseline and for a period with the fan speed control system active. Changing the fan type resulted in a savings of 47 percent of energy used by the air handling equipment and associated chiller plant energy needed to cool the air handlers themselves. The addition of the fan speed control resulted in an additional 37 percent savings in the same two categories. The combined savings for the two improvements for the same categories was 66 percent compared to the data center fitted with the original fans without a control system. The energy use reduction provided by the complete air handling device improvement program for the whole data center site is estimated to be 2.9 million kilowatt hours per year—an overall data center site savings of 8.0 percent. The reduced electrical energy use at the site provides a 1.9 million pound yearly reduction of carbon dioxide emissions. This demonstration showed that fan upgrades and a control system addition provide cost-effective improvements for data centers, with a payback reported to be under two years without utility incentives. In addition to the control system providing energy savings, the data collection and visual analysis capabilities provided immediate and long-term benefits. It is recommended that data center operators consider investing in fan upgrades and/or adding fan speed control for computer room air handlers.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗