Engineering topics

Kistler, C. W.

Publications and source records attributed to Kistler, C. W..

5 records

NASA NTRS1977

Methodology for designing accelerated aging tests for predicting life of photovoltaic arrays

A methodology for designing aging tests in which life prediction was paramount was developed. The methodology builds upon experience with regard to aging behavior in those material classes which are expected to be utilized as encapsulant elements, viz., glasses and polymers, and upon experience with the design of aging tests. The experiences were reviewed, and results are discussed in detail.

Gaines, G. B.↗

NASA NTRS1976

Review of world experience and properties of materials for encapsulation of terrestrial photovoltaic arrays

Published and unpublished information relating to encapsulation systems and materials properties was collected by searching the literature and appropriate data bases (over 1,300 documents were selected and reviewed) and by personal contacts including site and company visits. A data tabulation summarizing world experience with terrestrial photovoltaic arrays (50 installations) is presented in the report. Based on criteria of properties, processability, availability, and cost, candidate materials were identified which have potential for use in encapsulation systems for arrays with a lifetime of over 20 years high reliability, an efficiency greater than 10 percent, a total price less than $500/kW, and a production capacity of 500,000 kW/yr. The recommended materials (all commercially available) include, depending upon the device design, various borosilicate and soda-lime glasses and numerous polymerics suitable for specific encapsulation system functions.

Carmichael, D. C.↗

NASA NTRS1976

Materials for encapsulation systems for terrestrial photovoltaic arrays

The paper is concerned with glass and polymeric candidate materials and processes for potential encapsulation systems that could be used in low-cost long-life terrestrial photovoltaic arrays. The characteristics of encapsulation systems in use are reviewed, and the properties of proposed materials are examined. These materials include acrylics, epoxies, fluorocarbons, polycarbonates, polyesters, polyimides, polyxylylenes, and silicones. Properties of glass types are also considered. The prospects for glass and polymeric systems are analyzed, and the knowledge gained from a study of existing systems is discussed with attention to weather/aging effects, failures, environments, hazards, costs, development efforts, and materials choices.

Carmichael, D. C.↗

NASA NTRS1973

Evaluation of RSI Materials

Novel attachment and strain-measuring techniques were developed to obtain valid mechanical and thermophysical property data to above 1530 K in air on nonmetallic insulators and their coatings. The lever-arm extensometer developed used for measuring thermal and/or mechanical strain. Thermal expansion measurements were made on a tensile load to define their softening points. Creep characteristics of the insulators were monitored at elevated temperatures and found to become significant above 1090 K (1500 F).

Kistler, C. W.↗

NASA NTRS1970

Evaluation of nonmetallic thermal protection materials for the manned space shuttle. Volume 1, task 1: Assessment of technical risks associated with utilization of nonmetallic thermal protection system

Technical problems of design and flight qualification of the proposed classes of surface insulation materials and leading edge materials were reviewed. A screening test plan, a preliminary design data test plan and a design data test plan were outlined. This program defined the apparent critical differences between the surface insulators and the leading edge materials, structuring specialized screening test plans for each of these two classes of materials. Unique testing techniques were shown to be important in evaluating the structural interaction aspects of the surface insulators and a separate task was defined to validate the test plan. In addition, a compilation was made of available information on proposed material (including metallic TPS), previous shuttle programs, pertinent test procedures, and other national programs of merit. This material was collected and summarized in an informally structured workbook.

Wilkinson, W. H.↗