Using a two-dimensional algorithm, steering of triode slots was investigated for the first time with a reasonable accounting of the ion extraction sheath.

Two PLT-injector-type duoPIGatron sources, modified further by shaping the beam-forming apertures, have been tested and experimented on a prototype beam line similar to the ISX-B neutral beam injection system. The accelerator column modification has resulted in an increase of the beam power transmission efficiency from that of the straight-bore aperture by 50%. Maximum neutral beam powers achieved on a 28-cm-diam target simulating the ISX-B plasma, located 4.1 m downstream from the source, are congruent to 910 kW of H/sup 0/ at an accelerator power of 42 kV and 61 A and congruent to 1020 kW of D/sup 0/ at 43 kV and 55 A. Measurements have been made to investigate the following: the effects on beam optics of aperture shape, aspect ratio, and different ions (H/sup +/ or D/sup +/); the distribution of beam power deposition along the beam line; ion species compositions; and background pressure behavior due to scraped-off beam particles.

Experiments were performed to assess the operating characteristics and potential performance of water-augmented dry cooling systems. The work was aimed at evaluating a deluged air-cooled HOETERV plate fin heat exchanger surface proposed for integrated dry/wet cooling systems and using test results to guide the development of a predictive analytical model. In the process, all-dry performance data were obtained for the HOETERV surface as well as for two Curtiss-Wright chipped fin surfaces. The dry heat transfer data indicate that a slotted Curtiss-Wright surface slightly outperforms the HOETERV and nonslotted Curtiss-Wright surfaces based on heat rejection rate per unit of fan power. However, all three surfaces are so close in performance that other factors, such as surface cost and piping and mounting costs, will probably determine which surface is preferred at a given installation. Comparisons of deluged HOETERV performance with dry HOETERV and Curtiss-Wright performance under prototypic conditions have established that deluging can provide considerable heat rejection enhancement, particularly at low ITD and low air humidity. A deluged HOETERV core operating at a 115/sup 0/F primary fluid temperature in 105/sup 0/F air at 10% relative humidity can reject over 7 times as much heat as a dry HOETERV core operating under the …

Possible impacts of energy technologies on agriculture are evaluated, and some of the available simulation models that can be used for predictive purposes are identified. An overview of energy technologies and impacts on the environment is presented to provide a framework for the commentary on the models. Coal combustion is shown to have major impacts on the environment and these will continue into the next century according to current Department of Energy projections. Air pollution effects will thus remain as the major impacts on crop ecosystems. Two hundred reports were evaluated, representing a wide range of models increasing in complexity from mathematical functions (fitted to data) through parametric models (which represent phenomena without describing the mechanisms) to mechanistic models (based on physical, chemical, and physiological principles). Many models were viewed as suitable for adaptation to technology assessment through the incorporation of representative dose-response relationships. It is clear that in many cases available models cannot be taken and directly applied in technology assessment. Very few models of air pollutant-crop interactions were identified, even though there is a considerable data base of pollutant effects on crops.

The mirrors used on concentrating solar systems must be able to withstand severe and sustained environmental stresses for long periods of time if they are to be economically acceptable. Little is known about how commercially produced wet process silvered second surface mirrors will withstand the test of time in solar applications. Field experience in existing systems has shown that the performance of the reflective surface varies greatly with time and is influenced to a large extent by the construction details of the mirror module. Degradation of the reflective layer has been seen that ranges from non-observable to severe. The exact mechanisms involved in the degradation process are not well understood from either the phenomenological or microanalytical points of view and are thus subject to much debate. The three chapters of this report summarize the work recently performed in three general areas that are key to understanding and ultimately controlling the degradation phenomena. These areas are: a survey of the present commercial mirroring industry, the microanalytical examination of numerous degraded and nondegraded mirrors, and an investigation of several novel techniques that might be used to extend the life of heliostat mirrors. Appendices include: (a) list of mirror manufacturers and (b) recommended …

This report establishes standard unit costs and scaling rules for estimating costs of material, equipment, land, and labor components used in magnetic confinement fusion reactor plant construction and operation. Use of the standard unit costs and scaling rules will add uniformity to cost estimates, and thus allow valid comparison of the economic characteristics of various reactor concepts.

A report by the Office of Technology Assessment (OTA) that reviews "the state-of-the-art of the use of computer technology in medical education and assessment" and describes "the technologies and strategies for computer-based education and assessment, the current state of medical education and assessment activities, and computer applications in medicine" (p. iii).

This report inventories, analyzes, and appraises the existing socioeconomic data base for the ten counties in southwest Idaho that would be impacted by any significant geothermal development. The inventory describes key sociological demographic, and economic characteristics, and presents spatial boundaries, housing data, and projections of population and economic activity for the counties. The inventory identifies the significant gaps in the existing data base and makes recommendations for future research.

This report inventories, analyzes, and appraises the exiting socioeconomic data base for the ten counties in southwest Idaho that would be impacted by any significant geothermal development. The inventory describes key sociological demographic, and economic characteristics, and presents spatial boundaries, housing data, and projections of population and economic activity for the counties. The inventory identifies the significant gaps in the existing data base and makes recommendations for future research.

The first in six reports by the Office of Technology Assessment (OTA) that addresses "1) vaccine research, development, and production; 2)vaccine safety and efficacy; 3) cost-effectiveness of vaccination and implications for reimbursement; and 4) liability and compensation for vaccine-related injuries" (p. 4).

This regional assessment report portrays the major regional environmental, human health and safety, socioeconomic and institutional effects that might result from the implementation of one of a set of national energy supply and demand projections developed by the Department of Energy in 1978. General problem areas are identified and assessed on a regional and state basis that could either constrain or significantly modify the realization of the energy projections. Many of the issues identified are of a long-standing nature and would continue to exist, in spite of the particular energy projection used. The research and assessments reflected in this document were performed by six national laboratories. It is a compilation of individual reports prepared by Federal regions and available separately.