The US Department of Energy has set a 20-year lifetime goal for terrestrial photovoltaic modules. In its capacity as a Residential Photovoltaic Field Test and Applications Center, Massachusetts Institute of Technology Lincoln Laboratory has established and is monitoring experimental residential test sites in various locations of the United States. These sites contain either real or simulated residences coupled with photovoltaic modules from several manufacturers as well as the necessary balance-of-system components. Tests reported include visual and electrical inspection of modules, flash testing, and determination of module I-V curves.

A secondary optical element may be added to a parabolic dish solar concentrator to increase the geometric concentration ratio attainable at a given intercept factor. This secondary may be a Fresnel lens or a mirror, such as a compound elliptic concentrator or a hyperbolic trumpet. At a fixed intercept factor, higher overall geometric concentration may be obtainable with a long focal length primary and a suitable secondary matched to it. Use of a secondary to increase the geometric concentration ratio is more likely to be worthwhile if the receiver temperature is high and if errors in the primary are large. Folding the optical path with a secondary may reduce cost by locating the receiver and power conversion equipment closer to the ground and by eliminating the heavy structure needed to support this equipment at the primary focus. Promising folded-path configurations include the Ritchey-Chretien and perhaps some three-element geometries. Folding the optical path may be most useful in systems that provide process heat.

A two-year research and development program was initiated in April of 1979 to study the hydrochlorination of silicon tetrachloride and metallurgical grade (m.g.) silicon metal to trichlorosilane, 3 SiCl/sub 4/ + 2H/sub 2/ + Si in equilibrium 4 SiHCl/sub 3/. A laboratory scale pressure reactor was constructed to study this reaction at pressures up to 500 psig. Reaction kinetic measurements were carried out as a function of reactor pressure, reaction temperature and H/sub 2//SiCl/sub 4/ feed ratio. Based on the reaction kinetic data, the hydrochlorination of SiCl/sub 4/ and m.g. silicon metal is found to be an efficient process to produce SiHCl/sub 3/ in good conversions and in high yields. Copper is an effective catalyst. Results of a corrosion study show that conventional nickel-chromium alloys are suitable material of construction for the hydrochlorination reactor. The hydrochlorination reaction is relatively insensitive to external process parameters such as silicon particle size distribution and the impurities in the m.g. silicon metal.

This report covers the work carried out during the January-March 1981 quarter of the program. Preparations are being made to ready the equipment for the moisture tolerance test program. The main effort described pertains to the redesign and procurement of the main shaft bearing and seal system. To enhance the chances of achieving the program objectives, the recommendation was made by Lockheed to use a conventional roller bearing for the present program instead of the advanced water-lubricated bearing. Nevertheless, the need exists for better long-term solutions to the bearing and seal problem, especially in view of the eventual requirement to scale the equipment to larger sizes. It is recommended that the program proceed as planned.

A liquid-phase detection instrument (LPDI) has been developed to aid in making consistently accurate alloy sintering runs. The LPDI displays the furnace temperature, detects the alloy's liquid-phase arrest temperature, calculates the necessary hold temperature from the arrest temperature (i.e., calibrates the system), and provides a digital record for quality assurance purposes. In field tests, the instrument's detected arrest temperature was within +1/sup 0/ to -0/sup 0/C of an operator's assessment of the actual arrest temperature.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Mark White, regarding a legal question submitted for clarification; Construction of section 4, 5 and 66(c) of article V of the General Appropriations Act

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Mark White, regarding a legal question submitted for clarification; Notice requirements for changing boundary lines of election precinct under article 2.04 of the Election Code

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.

Daily newspaper from Sulphur Springs, Texas that includes local, state, and national news along with advertising.

This document reports results from the initial effort to establish baseline economic performance comparators for a program whose intent is to define, develop, and demonstrate advanced systems suitable for coal resource extraction beyond the year 2000. Systems used in this study were selected from contemporary coal mining technology and from conservative conjectures of year 2000 technology. The analysis was also based on a seam thickness of 6 ft. Therefore, the results are specific to the study systems and the selected seam thickness. To be more beneficial to the program, the effort should be extended to other seam thicknesses. This document is one of a series which describe systems level requirements for advanced underground coal mining equipment. Five areas of performance are discussed: production cost, miner safety, miner health, environmental impact, and recovery efficiency. The projections for cost and production capability comprise a so-called moving baseline which will be used to assess compliance with the systems requirement for production cost. Separate projections were prepared for room and pillar, longwall, and shortwall technology all operating under comparable sets of mining conditions. This work is part of an effort to define and develop innovative coal extraction systems suitable for the significant resources remaining …

B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.

B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.