Search NASA⌕ Search

SEARCH · Search NASA

Results for “Single use”

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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Analyzing System on A Chip Single Event Upset Responses using Single Event Upset Data, Classical Reliability Models, and Space Environment Data

We are investigating the application of classical reliability performance metrics combined with standard single event upset (SEU) analysis data. We expect to relate SEU behavior to system performance requirements. Our proposed methodology will provide better prediction of SEU responses in harsh radiation environments with confidence metrics. single event upset (SEU), single event effect (SEE), field programmable gate array devises (FPGAs)

single event effect (SEE)↗
NASA NTRS1987

Self-contained, single-use hose and tubing cleaning module

A self contained, single use hose and tubing cleaning module which utilizes available water supplies without requiring access to precision cleaning facilities is presented. The module is attached to the water source at the inlet side and to the hose or tubing to be cleaned at the outlet side. The water flows through a water purification zone, a detergent dispensing zone, a filtration zone before the detergent laden water flows into the tubing to clean the tubing walls. The module contains an embedded pad which is impregnated with a pH indicator to indicate to the user when the detergent has dissolved and rinsing of the tubing begins.

Rollins, Fred P.↗
NASA NTRS2018

Vegetation Height Estimate in Rice Fields Using Single Polarization TanDEM-X Science Phase Data

This study presents the retrieval of rice paddy height using single polarization (single-pol) interferometric SAR (InSAR) data by means of model-based height inversion without an external DEM. A total of eight TanDEM-X (TDX) scenes were used and the TDX images were; acquired using a large cross-track baseline configuration during the TDX Science Phase (June–August 2015). A single-pol inversion approach for a flooded rice field is proposed and evaluated over the Buan test site in South Korea. A novel approach is adopted for the estimation of the ground (i.e., water level) interferometric phase within a flooded rice paddy from TDX data acquired during a period of early rice growth. It is consequently possible to apply the model-based inversion algorithm to the single-pol InSAR data. Rice height maps during the rice growth cycle presented and validated by field measurements. The results demonstrated the high performance of the inversion with a correlation coefficient of 0.78 and an RMSE of 0.10 m. The proposed methodology will be useful to monitor rice plants and to predict a gross rice yield, along with dual and fully polarimetric interferometric SAR data.

Lee, Seung-Kuk↗
NASA NTRS2011

Crop and Substrate Tests with Single Use Rooting "Pillows" for the VEGGIE Plant Growth Hardware

VEGGIE is a small plant production chamber built by ORBITEC. This chamber can be collapsed for easy stowage and deployed in orbit. It is designed for gravity independent operation, and provides 0.17 square m of crop growth area with three primary subsystems: an LED light panel, extendable transparent Teflon bellows to enclose the plants, and a wicking reservoir. VEGGIE would provide the capability for astronauts to grow fresh foods for dietary supplementation. Initial planting concepts tested with the VEGGIE included direct seeding or plug placement on the reservoir surface. These options had issues of salt accumulation and eventual toxicity if the reservoir was filled with nutrient solution, and hardware reuse was limited due to sanitation. In response a rooting packet or "pillow" concept was developed: single-use bags of media containing time release fertilizer with a wicking surface contacting the VEGGIE reservoir. Pillows being tested are small electrostatic bags with a Nitex nylon mesh side, each holding 100 mL of dry media. Six pillows fit in one VEGGIE unit; however pillow size could vary depending on crop selected. Seeds can be planted directly in pillows and planted pillows can be hydrated in space as desired. Our goals were to define optimal media and crops for an ISS mission scenario. Plant tests in pillows were performed in a controlled environment chamber set to habitat-relevant conditions, and capillary reservoir analogs were utilized. Media tested within pillows included: a commercial peat-based potting mix, arcillite (calcined clay), perlite: vermiculite, and peat-based: arcillite blends. Testing included 15 types of leafy greens, snow pea, radish, and herbs. Media performance was crop dependent, but generally plants showed the greatest growth in the peat-based: arcillite mixes. Crops with the best performance in pillows were identified, and testing is underway with select leafy greens examining plant and microbial load response to repeated harvest. We plan to use findings from previous flight testing with media to evaluate the effects of capillary flow from the reservoir to pillows in microgravity.

Massa, Gioia↗
NASA NTRS1993

Optimal open-loop and feedback control using single gimbal control moment gyroscopes

Methods for control of spacecraft maneuvers through the use of single gimbal control moment gyroscopes are developed. The development employs an integrated model of the spacecraft dynamics with the control moment gyroscope dynamics. Smooth and continuous open-loop control profiles are obtained which minimize a weighted function of maneuver time, magnitude of control effort, and proximity to singular gimbal configurations. Closed-loop state feedback control laws are derived by invoking Lyapunov stability theory. The schemes are presented for implementing the commanded state feedback: gimbal rate control and gimbal acceleration control. The appropriate handling of singular gimbal configurations is also discussed.

Hoelscher, Brian R.↗
NASA NTRS1979

Base line estimation using single passes of laser data

The laser data of the GEOS 3 satellite passes observed by four stations at Greenbelt (Maryland), Bermuda, Grand Turk Island (Bahamas) and Patrick Air Force Base (Florida), were employed to determine precise interstation base lines and relative heights in short orbital arcs of no more than 12-min duration. No more than five arcs of data are required to define the interstation base lines to 30-cm precision. Base lines running parallel to the orbital motion can be defined to submeter precision from a single short arc of data. Combining arcs of different orbital geometry in a common adjustment of two or more stations relative to the base station helps to compensate for weak base line definition in any single arc. This technique can be used for tracking such spacecraft as Lageos, a high-altitude retroreflector-carrying satellite designed for precise laser ranging studies.

Dunn, P. J.↗
NASA NTRS1992

A 200 GHz tripler using single barrier varactor

The GaAs Schottky varactor diode is the nonlinear device most commonly used for submillimeter wave harmonic generation. Output power adequate to serve as a local oscillator source for SIS tunnel junctions has been demonstrated with whisker-contacted GaAs Schottky varactor multipliers in waveguide mounts up to about 800 GHz. In this paper, we present results for a tripler to 200 GHz using a new multiplier device, the single barrier varactor (SBV). This new varactor has a potential advantages such as stronger nonlinearities or special symmetry, which make it attractive for submillimeter wave frequency multiplication. The performance of a tripler using a SBV over a output frequency range from 186 to 207 GHz has been measured in a crossed waveguide mount. The theoretical performance of the device has been calculated using large signal analysis. A comparison of theoretical and measured results and a discussion of various losses in the mount and the varactor have also been presented.

Choudhury, Debabani↗
NASA NTRS2017

SpaRibs Geometry Parameterization for Wings with Multiple Sections using Single Design

The SpaRibs topology of an aircraft wing has a significant effect on its structural behavior and stability as well as the flutter performance. The development of additive manufacturing techniques like Electron Beam Free Form Fabrication (EBF3) has made it feasible to manufacture aircraft wings with curvilinear spars, ribs (SpaRibs) and stiffeners. In this article a new global-local optimization framework for wing with multiple sections using curvilinear SpaRibs is described. A single design space is used to parameterize the SpaRibs geometry. This method has been implemented using MSC-PATRAN to create a broad range of SpaRibs topologies using limited number of parameters. It ensures C0 and C1 continuities in SpaRibs geometry at the junction of two wing sections with airfoil thickness gradient discontinuity as well as mesh continuity between all structural components. This method is advantageous in complex multi-disciplinary optimization due to its potential to reduce the number of design variables. For the global-local optimization the local panels are generated by an algorithm which is totally based on a set algebra on the connectivity matrix data. The great advantage of this method is that it is completely independent of the coordinates of the nodes of the finite element model. It is also independent of the order in which the elements are distributed in the FEM. The code is verified by optimizing of the CRM Baseline model at trim condition at Mach number equal to 0.85 for five different angle of attack (-2deg, 0deg,2deg,4deg and 6deg). The final weight of the wing is 19,090.61 lb. This value is comparable to that obtained by Qiang et al. 6 (19,269 lb).

wing sections↗
NASA NTRS1962

Performance Evaluation of Fixed- and Variable-Area Rocket Exhaust Diffusers Using Single and Clustered Nozzles with and Without Gimbaling

An investigation of exhaust diffusers used for altitude simulation in testing rocket engines was conducted with model diffusers and gaseous nitrogen as the working fluid. This investigation was conducted to eval­uate the effects on performance of gimbaling clustered nozzles in a single fixed-area exhaust diffuser. A two-nozzle cluster was gimbaled in all attitudes in four different exhaust-diffuser configurations: (1) a straight circular tube, (2) a straight figure-eight tube, (3) a circular tube with a second throat, and (4) a figure-eight tube with a second throat. Gimbaling clustered nozzles had little effect on the operating pressure ratio for either straight-tube or second-throat diffusers, but caused a large increase in the starting-pressure-ratio requirements in some straight-tube exhaust diffusers. The performance of two or four clustered nozzles with no gimbaling was compared with single-nozzle per­formance on the basis of the ratio of diffuser area to nozzle-throat area. The performance was found to be dependent on the diffuser- to nozzle-throat-area ratio and independent of both the number of primary nozzles and the nozzle-area ratio. A separate investigation was also conducted to evaluate the per­formance improvement obtainable with a variable-area exhaust diffuser. This type of diffuser achieved a 26-percent reduction in starting pressure ratio, a 40-percent reduction in operating pressure ratio, and a 50-percent reduction in the overall diffuser length over the values attainable with a fixed-area second-throat diffuser.

ROCKET↗
NASA NTRS2010

Comparing Aircraft Observations of Snowfall to Forecasts Using Single or Two Moment Bulk Water Microphysics Schemes

High resolution weather forecast models with explicit prediction of hydrometeor type, size distribution, and fall speed may be useful in the development of precipitation retrievals, by providing representative characteristics of frozen hydrometeors. Several single or double-moment microphysics schemes are currently available within the Weather Research and Forecasting (WRF) model, allowing for the prediction of up to three ice species. Each scheme incorporates different assumptions regarding the characteristics of their ice classes, particularly in terms of size distribution, density, and fall speed. In addition to the prediction of hydrometeor content, these schemes must accurately represent the vertical profile of water vapor to account for possible attenuation, along with the size distribution, density, and shape characteristics of ice crystals that are relevant to microwave scattering. An evaluation of a particular scheme requires the availability of field campaign measurements. The Canadian CloudSat/CALIPSO Validation Project (C3VP) obtained measurements of ice crystal shapes, size distributions, fall speeds, and precipitation during several intensive observation periods. In this study, C3VP observations obtained during the 22 January 2007 synoptic-scale snowfall event are compared against WRF model output, based upon forecasts using four single-moment and two double-moment schemes available as of version 3.1. Schemes are compared against aircraft observations by examining differences in size distribution, density, and content. In addition to direct measurements from aircraft probes, simulated precipitation can also be converted to equivalent, remotely sensed characteristics through the use of the NASA Goddard Satellite Data Simulator Unit. Outputs from high resolution forecasts are compared against radar and satellite observations emphasizing differences in assumed crystal shape and size distribution characteristics.

Molthan, Andrew L.↗
NASA NTRSDate not supplied

10-kHz PLIF Thermometry for a Turbulent Jet Flame using Single Burst-mode OPO

Two-color Planar laser-induced fluorescence (TC-PLIF) thermometry techniques that employ two laser systems and two cameras face challenges when implemented in practical combustion facilities because of experimental complexity and multiple laser and camera requirements, particularly for high-speed TC-PLIF. To circumvent those problems, we developed a fast, dual-wavelength switching, burst-mode OPO technology to significantly reduce the experimental complexity of high-speed TC-PLIF thermometry and simplify its implementation in harsh combustion and flow test facilities. A fast, dual-wavelength switched seed laser enabled a high-energy, high-repetition-rate burst-mode laser to generate two 10-kHz pulse trains at wavelengths of ~354.8 nm. The injection-seeded OPO efficiently converts the burst-mode laser output to285.62 nm and 285.67 nm to excite the Q2(12) and P1(8) OH transitions. PLIF images were collected from each of the two excitation transitions with a single camera and an UV intensifier, and intensity ratios from the images were used to determine local temperatures. Ten kHz hydroxyl radical (OH) TC-PLIF for premixedCH4/Air/H2 jet flame was demonstrated.

thermometry↗
NASA NTRSDate not supplied

10-kHz PLIF Thermometry for Turbulent Jet Flame using Single Burst-mode OPO

Two-color Planar Laser-Induced Fluorescence (TC-PLIF) thermometry techniques that employ two laser systems and two cameras face challenges when implemented in practical combustion facilities because of experimental complexity and multiple laser and camera requirements, particularly for high-speed TC-PLIF. To circumvent those problems, we developed a fast, dual-wavelength switching, burst-mode OPO technology to significantly reduce the experimental complexity of high-speed TC-PLIF thermometry and simplify its implementation in harsh combustion and flow test facilities. A fast, dual-wavelength switched seed laser enabled a high-energy, high-repetition-rate burst-mode laser to generate two 10-kHz pulse trains at wavelengths of ~354.8 nm. The injection-seeded OPO efficiently converts the burst-mode laser output to 285.62 nm and 285.67 nm to excite the Q2(12) andP1(8) OH transitions. PLIF images were collected from each of the two excitation transitions with a single camera and an UV intensifier, and intensity ratios from the images were used to determine local temperatures. Ten kHz hydroxyl radical (OH) TC-PLIF for premixedCH4/Air/H2 jet flame was demonstrated.

thermometry↗
NASA NTRS1992

Using single buffers and data reorganization to implement a multi-megasample fast Fourier transform

Data ordering in large fast Fourier transforms (FFT's) is both conceptually and implementationally difficult. Discribed here is a method of visualizing data orderings as vectors of address bits, which enables the engineer to use more efficient data orderings and reduce double-buffer memory designs. Also detailed are the difficulties and algorithmic solutions involved in FFT lengths up to 4 megasamples (Msamples) and sample rates up to 80 MHz.

Brown, R. D.↗
NASA NTRS1990

Unsteady transonic Navier-Stokes computations for an oscillating wing using single and multiple zones

Modern jet transports and maneuvering tactical fighters operating in the transonic regime often give rise to time-dependent fluid physics that interact with flexible structural components, e.g., vortical flow, shocks, and separation. Efficient computational fluid dynamic (CFD) methods are required to study such computationally intensive problems. In this work a numerical method is presented to address this problem. Time-dependent, compressible, Navier-Stokes equations are used to simulate unsteady transonic flow about a three-dimensional rigid wing undergoing a forced periodic motion in angle of attack. An efficient, implicit, diagonal algorithm is utilized because of its low operation count per time step compared to other methods that solve systems of block matrix equations. The formal time accuracy is addressed theoretically and demonstrated numerically by comparison of computational results with experimental data. A zonal grid approach, capable of treating complex geometries, is presented and its time accuracy is demonstrated by comparing a zonal computation with a single grid computation and experimental data.

Chaderjian, Neal M.↗
NASA NTRS1970

Color television system using single gun color cathode ray tube

Two-primary color and single gun system provides quality differential color and variation in brightness for specific colors by varying current and controlling duty cycle of electron beam. Number of video amplifiers, deflection circuits, and guns required to display color TV picture is reduced and less complex tube is required.

Gaiser, E. E.↗
NASA NTRS1974

Characteristics of epitaxial garnets grown by CVD using single metal alloy sources

Single metal alloys have been explored as the cation source in the chemical vapor deposition (CVD) of iron garnets. Growth of good quality single crystal garnet films containing as many as five different cations has been achieved over a wide range of deposition conditions. The relationship of film composition to alloy compositions and deposition conditions has been determined for several materials. By proper choice of the alloy composition and the deposition conditions, uncrazed deposits were grown on (111) gadolinium gallium garnet (GGG) substrates. Data on physical, magnetic and optical properties of representative films is presented and discussed.

Besser, P. J.↗
NASA NTRS1974

Digital adaptive flight control design using single stage model following indices

Simple mechanical linkages are often unable to cope with many control problems associated with high-performance aircraft. This has led to the development of digital fly-by-wire control systems and in particular digital adaptive controllers that can be efficiently adjusted during system operation. To this effect, a control law has been derived based upon the minimization of a single-stage weighted combination of control energy and the squared error between the states of a linear plant and model. This control logic is interfaced with an on-line weighted least-squares estimator and a Kalman state filter. The utility of the resultant control system is illustrated by its application to the linearized dynamics of a typical fighter aircraft.

Alag, G.↗