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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Laboratory Monitoring of Bone Tissue Remodeling after Augmentation of Impression Intraarticular Fracture with Different Types of Bone Graft

The effects of bone graft materials on the inflammatory response and biochemical markers of bone remodeling were studied on a rabbit model of fracture augmentation with the following grafts: β-tricalcium phosphate, demineralized bone matrix, nanostructured carbon implant, and porous titanium implant made by additive 3D printing. The markers of bone remodeling and the blood system response in the postoperative period were studied. It was found that porous titanium implant and β-tricalcium phosphate induced osteogenesis and minimized osteoclastic resorption. Augmentation with nanostructured carbon implant and demineralized bone matrix stimulated the processes of osteoclastic resorption.

3D PRINTING↗
DOE OSTI2015

Impression of plasma voltage on growth of α-V{sub 2}O{sub 5} nanostructured thin films

In this communication, we synthesized vanadium pentoxide (α-V{sub 2}O{sub 5}) nanostructured thin films (NST{sub s}) accompanied with nanoflakes/ nanoplates on the Ni-coated glass substrates employing plasma assisted sublimation process (PASP) as a function of plasma voltage (V{sub p}). The effect of plasma voltage on structural, morphological, compositional, and vibrational properties have been studied systematically. The structural analysis divulged that all films deposited at different V{sub p} have pure orthorhombic phase, no impurity phase is detected under resolution limit of XRD and XPS. The morphological studies of samples is carried out by SEM, revealed that features as well as alignment of V{sub 2}O{sub 5} NST{sub s} is greatly monitored by V{sub p} and the film possessing the best features is obtained at 2500volt. In addition, XPS results reveal that V{sup 5+} oxidation state is the most prominent state in sample V{sub 2}, which represents better stoichiometric nature of film. The vibrational study of all samples is performed by FTIR and strongly support the XRD observations. All the results are in consonance with each other.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

User Impressions and Gait Analysis of Exoskeleton Device Usage in Generalized Tank Farm Activities

Tank farm workers involved in nuclear cleanup activities perform physically demanding tasks, typically while wearing heavy personal protective equipment (PPE). Exoskeleton devices have the potential to bring considerable benefit to this industry but have not been thoroughly studied in the context of nuclear cleanup. In this paper, we examine the performance of exoskeletons during a series of tasks emulating jobs performed on tank farms while participants wore PPE commonly deployed by tank farm workers. The goal of this study was to evaluate the effects of commercially available lower-body exoskeletons on a user’s gait kinematics and user perceptions. Three participants each tested three lower-body exoskeletons in a 70-min protocol consisting of level treadmill walking, incline treadmill walking, weighted treadmill walking, a weight lifting session, and a hand tool dexterity task. Results were compared to a no exoskeleton baseline condition and evaluated as individual case studies. The three participants showed a wide spectrum of user preferences and adaptations toward the devices. Individual case studies revealed that some users quickly adapted to select devices for certain tasks while others remained hesitant to use the devices. Temporal effects on gait change and perception were also observed for select participants in device usage over the course of the device session. Here, device benefit varied between tasks, but no conclusive aggregate trends were observed across devices for all tasks. Evidence suggests that device benefits observed for specific tasks may have been overshadowed by the wide array of tasks used in the protocol.

Tank farm↗
DOE OSTI2019

Fundamental Forces, Lasting Impressions: Historical Documentation of the Sigma Press Building (TA-3-35) Volume 1

The US Department of Energy, National Nuclear Security Administration, Los Alamos Field Office (Field Office) has prepared final documentation for the resolution of adverse effects to Building 35 in Technical Area (TA) 3 at Los Alamos National Laboratory (LANL or the Laboratory). This documentation is being submitted to the New Mexico State Historic Preservation Officer (SHPO). TA-3-35, a Cold War-era press building, was determined eligible for listing in the National Register of Historic Places (Register) in the report Pressing Matters: An Evaluation of the Cold War Buildings at the Sigma Complex (LA-UR-15-28961). This report also identified Building TA-3-35 as excess property to be decontaminated, decommissioned, and demolished by the LANL Footprint Reduction Program in Fiscal Year 2016, an adverse effect requiring mitigation. The SHPO concurred with the both the eligibility determination of, and adverse impact to, Building TA-3-35 on February 29, 2016.

42 ENGINEERING↗
DOE OSTI2023

First Impressions: Early-time Classification of Supernovae Using Host-galaxy Information and Shallow Learning

Substantial effort has been devoted to the characterization of transient phenomena from photometric information. Automated approaches to this problem have taken advantage of complete phase coverage of an event, limiting their use for triggering rapid follow-up of ongoing phenomena. In this work, we introduce a neural network with a single recurrent layer designed explicitly for early photometric classification of supernovae (SNe). Our algorithm leverages transfer learning to account for model misspecification, host-galaxy photometry to solve the data-scarcity problem soon after discovery, and a custom weighted loss to prioritize accurate early classification. We first train our algorithm using state-of-the-art transient and host-galaxy simulations, then adapt its weights and validate it on the spectroscopically confirmed SNe Ia, SNe II, and SNe Ib/c from the Zwicky Transient Facility Bright Transient Survey. On observed data, our method achieves an overall accuracy of 82% ± 2% within 3 days of an event’s discovery, and an accuracy of 87% ± 5% within 30 days of discovery. At both early and late phases, our method achieves comparable or superior results to the leading classification algorithms with a simpler network architecture. These results help pave the way for rapid photometric and spectroscopic follow-up of scientifically valuable transients discovered in massive synoptic surveys.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1970

Pilot impressions of lifting body vehicles

Piloting aspects of the lifting body vehicles are discussed in this paper by two of the pilots assigned to the flight program. Subjects discussed include: approach, landing, and energy management considerations; field of view requirements, stability considerations, and vehicle riding qualities, including the effects of turbulence. Remarks pertinent to the various subject areas are made by each pilot.

William H Dana↗
NASA NTRS1974

Outer planet probe cost estimates: First impressions

An examination was made of early estimates of outer planetary atmospheric probe cost by comparing the estimates with past planetary projects. Of particular interest is identification of project elements which are likely cost drivers for future probe missions. Data are divided into two parts: first, the description of a cost model developed by SAI for the Planetary Programs Office of NASA, and second, use of this model and its data base to evaluate estimates of probe costs. Several observations are offered in conclusion regarding the credibility of current estimates and specific areas of the outer planet probe concept most vulnerable to cost escalation.

Niehoff, J.↗
NASA NTRS1975

Duct wall impedance control as an advanced concept for acoustic impression

Models and tests on an acoustic duct liner system which has the property of controlled-variable acoustic impedance are described. This is achieved by a novel concept which uses the effect of steady air flow through a multi-layer, locally reacting, resonant-cavity absorber. The scope of this work was limited to a 'proof of concept.' The test of the concept was implemented by means of a small-scale, square-section flow duct facility designed specifically for acoustic measurements, with one side of the duct acoustically lined. The test liners were designed with the aid of previously established duct acoustic theory and a semi-empirical impedance model of the liner system. Over the limited range tested, the liner behaved primarily as predicted, exhibiting significant changes in resistance and reactance, thus providing the necessary concept validation.

Dean, P. D.↗
NASA NTRS1976

Viking-1 meteorological measurements - First impressions

A preliminary evaluation is given of in situ meteorological measurements made by Viking 1 on Mars. The data reported show that: (1) the atmosphere has approximate volume mixing ratios of 1.5% argon, 3% nitrogen, and 95% carbon dioxide; (2) the diurnal temperature range is large and regular, with a sunrise minimum of about 188 K and a midafternoon maximum near 244 K; (3) air and ground temperatures coincide quite closely during the night, but ground temperature exceeds air temperature near midday by as much as 25 C; (4) the winds exhibit a marked diurnal cycle; and (5) a large diurnal pressure variation with an afternoon minimum and an early-morning maximum parallels the wind pattern. The variations are explained in terms of familiar meteorological processes. It is suggested that latent heat is unlikely to play an important role on Mars because no evidence has been observed for traveling synoptic-scale disturbances such as those that occur in the terrestrial tropics.

Hess, S. L.↗
NASA NTRS1987

Taking Impressions of Hidden Cavity Walls

Lightweight, portable internal-molding device makes it possible to measure radii of, or examine contours of, passageways in hidden or complicated cavities. With device, measurements made in field, without returning assemblies to shop or laboratory for inspection. Molding head expands when compressed air applied. Inflatable tubes around head perform dual sealing and aligning function.

Burley, D.↗
NASA NTRS1991

Flexible Interior-Impression-Molding Tray

Device used inside combustion chamber of complicated shape for nondestructive evaluation of qualities of welds, including such features as offset, warping, misalignment of parts, and dropthrough. Includes flexible polypropylene tray trimmed to fit desired interior surface contour. Two neodymium boron magnets and inflatable bladder attached to tray. Tray and putty inserted in cavity to make mold of interior surface.

Anders, Jeffrey E.↗