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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 91 records · Page 5

Extension of similarity test procedures to cooled engine components with insulating ceramic coatings

Material thermal conductivity was analyzed for its effect on the thermal performance of air cooled gas turbine components, both with and without a ceramic thermal-barrier material, tested at reduced temperatures and pressures. The analysis shows that neglecting the material thermal conductivity can contribute significant errors when metal-wall-temperature test data taken on a turbine vane are extrapolated to engine conditions. This error in metal temperature for an uncoated vane is of opposite sign from that for a ceramic-coated vane. A correction technique is developed for both ceramic-coated and uncoated components.

Gladden, H. J.↗

Cell-level reliability testing procedures for CIGS photovoltaics

The reliability of photovoltaics is commonly studied at the module level. Many reliability problems originate from module attributes, such as metal interconnections to cells, junction boxes. However, significant work in reliability can also be done prior to module design. Testing for reliability earlier in the research cycle increases the probability of avoiding common module reliability problems before cell changes are implemented on a large scale. Cell-level reliability studies can thus lower the rates of module failures in the field and provide confidence to investors that new technologies will perform as advertised. This report summarizes how we investigated three reliability concerns in Cu(In,Ga)Se 2 (CIGS) photovoltaics at the cell level: metastability, shading-induced damage, and potential-induced degradation (PID). We find that examining these concerns required developing robust measurement protocols including the fabrication of novel testing structures. This information will allow readers to incorporate sound metrics for investigating reliability phenomena and aid their studies of cell and module reliability improvements.

14 SOLAR ENERGY↗

A summary of the test procedures and operational details of a Delaware River and an ocean dumping pollution monitoring experiment conducted 28 August 1975

Two remote sensor evaluation experiments are discussed. One experiment was conducted at the DuPont acid-dump site off the Delaware coast. The second was conducted at an organic waste outfall in the Delaware River. The operational objective of obtaining simultaneous sea truth sampling with remote sensors overpasses was met. Descriptions of the test sites, sensors, sensor platforms, flight lines, sea truth data collected, and operational chronology are presented.

Hypes, W. D.↗

Human Factors Process Task Analysis: Liquid Oxygen Pump Acceptance Test Procedure at the Advanced Technology Development Center

This viewgraph presentation provides information on Human Factors Process Failure Modes and Effects Analysis (HF PFMEA). HF PFMEA includes the following 10 steps: Describe mission; Define System; Identify human-machine; List human actions; Identify potential errors; Identify factors that effect error; Determine likelihood of error; Determine potential effects of errors; Evaluate risk; Generate solutions (manage error). The presentation also describes how this analysis was applied to a liquid oxygen pump acceptance test.

Diorio, Kimberly A.↗

Automating Test Procedures Using Robot Software

This paper will discuss the project I was assigned during the 2018 Spring semester NIFS internship, what the project does for NASA, and what I contributed to the project. It will begin with a broad analysis of the types of software I worked on and how they were used to complete the project. Then, it will narrow in scope to concentrate on the group and parts of NASA assigned the project. Next, it will pay attention to the project itself and how it worked. After that, it will focus on my direct contributions to the project. Lastly, a few personal experiences I encountered to make my internship relatable. The initial points discussed will be an introduction to the basics of automated testing and the types of software used. Next, I will briefly discuss why these tools were chosen and whether or not they can be improved. Then, a look at where my group fits into the hierarchy of NASA, what the group working on my project did for NASA, and who were the entities working together for this project. Afterwards, a review of my involvement in the program, my development as an individual, and my new skills and abilities. Finally, a sense of involvement with the community through personal development will be demonstrated using unique experiences only available to me through this internship..

SikuliX↗

Module Testing Procedures and Results for the CMS Phase-2 Outer Tracker Upgrade at Fermilab

The High-Luminosity LHC (HL-LHC) will operate at significantly increased luminosities and is expected to deliver about 3000 $fb^{-1}$ of proton-proton collision data at $\sqrt{s}=14$ TeV over a decade of operation. To maintain efficient tracking and triggering performance under high pileup and radiation conditions, the CMS experiment is upgrading its tracking detector for Phase-2 operations. The upgraded Outer Tracker (OT) will consist of Pixel-Strip (PS) and Strip-Strip (2S) silicon modules capable of providing tracking information to the Level-1 trigger at 40 MHz. Production and qualification of OT modules have been ongoing for about one year across several assembly and testing centers in the US, Europe, India, and Pakistan, requiring extensive testing to ensure stable operation in the HL-LHC environment. Fermilab is responsible for the production and testing of a significant fraction of the OT modules. The testing activities include IV characterization of silicon sensors, noise and pedestal measurements, verification of communication between module components, and burn-in studies using cold-box systems operated under controlled thermal conditions. Results from module testing and qualification studies performed during production will be presented.

Baradia, Sweta [UC, Davis (main)]↗

A Versatile Drop Test Procedure for the Simulation of Impact Environments

In order to assure the reliability of space flight systems and spacecraft, it is necessary to subject these systems, vehicles, and their components to expected shock and impact environmental loads. The Langley Laboratory has found the apparatus and methods discussed in this paper useful in its work along these lines, and feels that other organizations might also find them of value.

Drop test↗

Application of Self Nulling Eddy Current Probe Technique to the Detection of Fatigue Crack Initiation and Control of Test Procedures

A major part of fracture mechanics is concerned with studying the initiation and propagation of fatigue cracks. This typically requires constant monitoring of crack growth during fatigue cycles and the knowledge of the precise location of the crack tip at any given time. One technique currently available for measuring fatigue crack length is the Potential Drop method. The method, however, may be inaccurate if the direction of crack growth deviates considerably from what was assumed initially or the curvature of the crack becomes significant. Another popular approach is to optically view the crack using a high magnification microscope, but this entails a person constantly monitoring it. The present proposed technique uses an automated scheme, in order to eliminate the need for a person to constantly monitor the experiment. Another technique under development elsewhere is to digitize an optical image of the test specimen surface and then apply a pattern recognition algorithm to locate the crack tip. A previous publication showed that the self nulling eddy current probe successfully tracked a simulated crack in an aluminum sample. This was the impetus to develop an online real time crack monitoring system. An automated system has been developed which includes a two axis scanner mounted on the tensile testing machine, the probe and its instrumentation and a personal computer (PC) to communicate and control all the parameters. The system software controls the testing parameters as well as monitoring the fatigue crack as it propagates. This paper will discuss the experimental setup in detail and demonstrate its capabilities. A three dimensional finite element model is utilized to model the magnetic field distribution due to the probe and how the probe voltage changes as it scans the crack. Experimental data of the probe for different samples under zero load, static load and high cycle fatigue load will be discussed. The final section summarizes the major accomplishments of the present work, the elements of the future R&D needs and the advantages and disadvantages of using this system in the laboratory and field.

Namkung, M.↗

Heat-transfer testing procedures in phase B shuttle studies with emphasis on phase change data improvement

The procedures used in the application of the phase change technique to the phase B shuttle configuration are discussed along with factors which may affect data accuracy. These factors include variation of thermal properties of phase change model material, sensitivity of measured heat transfer coefficients to the assumed value of the adiabatic to total temperature ratio, and wall temperature effects. These sensitivities are illustrated in sample calculations for a shuttle geometry. Factors which may affect the visual clarity and interpretation of phase change data are discussed, and a method of improving photographic data quality through the use of polarized light is presented.

Throckmorton, D. A.↗

SYMAT, COVAR: Test Procedures for Matrix Calculations

The FORTRAN subroutine SYMAT and related subroutines are described. In essence SYMAT is an iterative algorithm in which the problem of finding eigenvalues and eigenvectors of a real symmetric matrix is transformed into an equivalent problem of finding eigenvalues and eigenvectors of an infinite sequence of matrices of order two. A DEMO PROGRAM contains a subroutine COVAR which is used to compute the covariance matrix (denoted by A) of a data matrix (denoted by X). Since a covariance matrix is symmetric it can be analyzed by using subroutine SYMAT.

Morris, W. L.↗

Test procedure for Hasselblad field irradiance

The procedure is defined for determining the uniformity of film plane illumination (field irradiance) of the Hasselblad cameras. The data source shall consist of photographs, with X-Y scans being taken for indication only. The accuracy requirement is 2.0%.

George, C.↗

Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state

The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking.

Lifka, B. W.↗

Test procedures and performance measures sensitive to automobile steering dynamics

A maneuver complex and related performance measures used to evaluate driver/vehicle system responses as effected by variations in the directional response characteristics of passenger cars are described. The complex consists of normal and emergency maneuvers (including random and discrete disturbances) which, taken as a whole, represent all classes of steering functions and all modes of driver response behavior. Measures of driver/vehicle system response and performance in regulation tasks included direct describing function measurements and rms yaw velocity. In transient maneuvers, measures such as steering activity and cone strikes were used.

Klein, R. H.↗