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Susceptibilities of power metal-oxide/semiconductor field-effect transistors (MOSFET's) to single-event gate ruptures analyzed by exposing devices to beams of energetic bromine ions while applying appropriate bias voltages to source, gate, and drain terminals and measuring current flowing into or out of each terminal.
Two related computer programs written for use in analyzing leakage through cracks. Leakage flow laminar or turbulent. One program used to determine dimensions of crack under given flow conditions and given measured rate of leakage. Other used to determine rate of leakage of gas through crack of given dimensions under given flow conditions. Programs, written in BASIC language, accelerate and facilitate iterative calculations and parametric analyses. Solve equations of Fanno flow. Enables rapid solution of leakage problem.
This manual updates the original 1986 NASA TP-2515, Integrated Composite Analyzer (ICAN) Users and Programmers Manual. The various enhancements and newly added features are described to enable the user to prepare the appropriate input data to run this updated version of the ICAN code. For reference, the micromechanics equations are provided in an appendix and should be compared to those in the original manual for modifications. A complete output for a sample case is also provided in a separate appendix. The input to the code includes constituent material properties, factors reflecting the fabrication process, and laminate configuration. The code performs micromechanics, macromechanics, and laminate analyses, including the hygrothermal response of polymer-matrix-based fiber composites. The output includes the various ply and composite properties, the composite structural response, and the composite stress analysis results with details on failure. The code is written in FORTRAN 77 and can be used efficiently as a self-contained package (or as a module) in complex structural analysis programs. The input-output format has changed considerably from the original version of ICAN and is described extensively through the use of a sample problem.
The University of Texas at Dallas (UTD) Center for Space Sciences (CSS) has designed, developed, and fabricated three miniature mass spectrometers and their associated instrumentation in fulfillment of a NASA contract. The ion mass spectrometer analyzers furnished under this contract were modeled after a unit developed during a previous NASA grant. Three assemblies are described: (1) the magnetic sector; (2) the ion detector; and (3) the amplifier and power supply.
This manual describes the organization and flow of data and analysis modules in the computer code, HITCAN (High Temperature Composite ANalyzer). HITCAN is a general purpose computer program for predicting nonlinear global structural and local stress-strain response of arbitrarily oriented, multilayered high temperature metal matrix composite structures. This manual describes the architecture of the HITCAN code, followed by the listing of subroutines and calling tree, data storage scheme, file system, and a dictionary of code terminology. The primary intention of the manual is to familiarize the user with some of the computer program related issues so as to facilitate maintenance/modification/updates of the HITCAN computer code.
This manual comprises a variety of demonstration cases for the HITCAN (HIgh Temperature Composite ANalyzer) code. HITCAN is a general purpose computer program for predicting nonlinear global structural and local stress-strain response of arbitrarily oriented, multilayered high temperature metal matrix composite structures. HITCAN is written in FORTRAN 77 computer language and has been configured and executed on the NASA Lewis Research Center CRAY XMP and YMP computers. Detailed description of all program variables and terms used in this manual may be found in the User's Manual. The demonstration includes various cases to illustrate the features and analysis capabilities of the HITCAN computer code. These cases include: (1) static analysis, (2) nonlinear quasi-static (incremental) analysis, (3) modal analysis, (4) buckling analysis, (5) fiber degradation effects, (6) fabrication-induced stresses for a variety of structures; namely, beam, plate, ring, shell, and built-up structures. A brief discussion of each demonstration case with the associated input data file is provided. Sample results taken from the actual computer output are also included.
This manual outlines some of the theoretical aspects embedded in the computer code, HITCAN (High Temperature Composite ANalyzer). HITCAN is a general purpose computer program for predicting nonlinear global structural and local stress-strain response of arbitrarily oriented, multilayered high temperature metal matrix composite structures. This code combines composite mechanics and laminate theory with an internal data base of the constituents (matrix, fiber and interface) material properties. The thermal and mechanical properties of the constituents are considered to be nonlinearly dependent on several parameters including temperature, stress and stress rate. The computational procedure for the analysis of the composite structure uses the finite element method. HITCAN consists of three modules: COBSTRAN, METCAN and MHOST. COBSTRAN generates the geometry (pre-processor) and defines the layup of the different plies. METCAN computes the material behavior of the composite and of the constituents. Finally, MHOST is a finite element program based on the mixed iterative solution technique. MHOST has a library for 2D and 3D isoparametric elements. HITCAN is written in FORTRAN 77 computer language and has been configured and executed on the NASA Lewis Research Center CRAY XMP and YMP computers.
This manual describes 'how-to-use' the computer code, HITCAN (HIgh Temperature Composite ANalyzer). HITCAN is a general purpose computer program for predicting nonlinear global structural and local stress-strain response of arbitrarily oriented, multilayered high temperature metal matrix composite structures. This code combines composite mechanics and laminate theory with an internal data base for material properties of the constituents (matrix, fiber and interphase). The thermo-mechanical properties of the constituents are considered to be nonlinearly dependent on several parameters including temperature, stress and stress rate. The computation procedure for the analysis of the composite structures uses the finite element method. HITCAN is written in FORTRAN 77 computer language and at present has been configured and executed on the NASA Lewis Research Center CRAY XMP and YMP computers. This manual describes HlTCAN's capabilities and limitations followed by input/execution/output descriptions and example problems. The input is described in detail including (1) geometry modeling, (2) types of finite elements, (3) types of analysis, (4) material data, (5) types of loading, (6) boundary conditions, (7) output control, (8) program options, and (9) data bank.
Viewgraphs on a distributed system for visualizing and analyzing multivariate and multidisciplinary data are presented. Topics covered include: program objectives; and the linked windows interactive data system (LinkWinds).
The modified plasma dispersion function Z* sub kappa (xi) based on the generalized Lorentzian distribution, which was introduced by Summers and Thorne (1991), is used to analyze three classical problems of plasma physics. These include the Landau damping of Langmuir waves, the ion acoustic instability in a current-carrying plasma, and the cyclotron resonant instability of electromagnetic R mode waves propagating parallel to an ambient magnetic field. It was found that, in each case, the results for a generalized Lorentzian plasma can differ significantly from those for a Maxwellian plasma. It is suggested that previous calculations based on a Maxwellian plasma distribution function Z(xi) have to be reexamined.
The performance of a Phase Doppler Particle Analyzer (PDPA) based icing probe suitable for use in icing tunnels and airborne applications is assessed. The instrument is shown to accurately and repeatably measure liquid water content (LWC) to within better than 20 percent of the nominal expected value in the NASA Lewis IRT. This was seen to be true over a wide range of tunnel operating conditions. The principles used by the PDPA for MVD and LWC determination are discussed. Calibration curves for the IRT median volume diameter are also determined and compared to the existing calibration determined via the PMS instruments. As has been shown in previous work, the PDPA is quite repeatable. The results are typically 3 to 5 microns smaller than the existing calibrations for a given run condition. Reasons for these differences are also discussed.
Response time and accuracy are sensitive measures of overall performance but may mask underlying response strategies. For example, analysis of latency and accuracy measures produced in a computerized-maze task does not reveal whether rhesus monkeys really 'solve a maze' or simply move as much as is possible toward the target, negotiating barriers through trial and error as they encounter them. Regression procedures are described for analyzing response path against several hypothetical response curves, and analyses of response path for rhesus monkeys' performance on the computerized MAZE task are presented as an illustration. The data suggest that rhesus monkeys do invoke a response strategy of solving the maze, because the observed response topography is significantly associated with the optimal path of responding. Many experimental paradigms should similarly benefit from analysis of the response paths that subjects exhibit.
An ASDA model developed to evaluate the heat and mass transfer characteristics of advanced pressurized suit design concepts for low pressure or vacuum planetary applications is presented. The model is based on a generalized 3-layer suit that uses the Systems Integrated Numerical Differencing Analyzer '85 in conjunction with a 41-node FORTRAN routine. The latter simulates the transient heat transfer and respiratory processes of a human body in a suited environment. The user options for the suit encompass a liquid cooled garment, a removable jacket, a CO2/H2O permeable layer, and a phase change layer.
An on-board Volatile Organic Analyzer (VOA), an essential component of the Environmental Health System (EHS) air-quality monitoring strategy, is described. The strategy is aimed at warning the crew and ground personnel if volatile compounds exceed safe exposure limits. The VOA uses a combination of gas chromatography (GC) and ion-mobility spectrometry (IMS) for environmental monitoring and analysis. It is concluded that the VOA dual-mode detection capability and the ion mobilities in the drift region are unique features that can assist in the resolution of coeluting GC peaks. The VOA is capable of accurately identifying and quantifying target compounds in a complex mixture.
A user's manual is described and is provided for ASAP, an automated tool for static source code analysis of programs written in the Ada programming language. The purpose of the analysis is to collect and store information pertaining to the analyzed Ada compilation unit's size, complexity, usage of Ada language constructs and features, and static interface with other Ada compilation units.
SEAL computer program analyzes steady-state performance of face seal with two-phase leakage flow. Calculates general trends of performance under both low- and high-leakage conditions and, by extrapolation, behavior in intermediate region. Parameters investigated include subcooling, coning of seal faces, speeds of rotation, conductivities of seal materials, and widths of seal faces. Program incorporates idealized mathematical models, and based on finite-difference approach. Written in FORTRAN 77.
Integrated Composites Analyzer (ICAN/PC) computer program designed to carry out comprehensive linear analysis of multilayered continuous-fiber polymer matrix composites. Performs micromechanics, macromechanics, and laminate analyses, taking account of hygrothermal responses of fiber composites. Written in FORTRAN 77.
Theory and computer codes developed for use in analyzing propagation of sinusoidal components of fluctuations of pressure (acoustic waves) through fluid in diffuser and in volute or discharge duct of centrifugal pump. Reflections from impedance mismatches taken into account. Such analysis of propagation and resultant fluctuations of pressure important part of analysis of fluid-borne contributions to stresses on volute housing, volute liner, and/or discharge duct.