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Mode of access: Internet.

The need for an improved control strategy for the operation of a wind-powered refrigeration system for the storage of apples was investigated. The results are applicable to other systems which employ intermittently available power sources, battery and thermal storage, and an auxiliary, direct current power supply. Tests were conducted on the wind-powered refrigeration system at the Virginia Polytechnic Institute and State University Horticulture Research Farm in Blacksburg, Virginia. Tests were conducted on the individual components of the system. In situ windmill performance were also conducted. The results of these tests have been presented. An improved control strategy was developed to improve the utilization of available wind energy and to reduce the need for electrical energy from an external source while maintaining an adequate apple storage environment. Ph. D.

Performed in cooperation with the School of Mineral Engineering, University of Washington. ; Includes bibliographical references. ; Mode of access: Internet.

The Greenland Ice Sheet, which extends south of the Arctic Circle, is vulnerable to melt in a warming climate. Complete melt of the ice sheet would raise global sea level by about 7 meters. Prediction of how the ice sheet will react to climate change requires inputs with a high degree of spatial resolution and improved simulation of the ice-dynamical responses to evolving surface mass balance. No Greenland Ice Sheet model has yet met these requirements.A three-dimensional thermo-mechanical ice sheet model of Greenland was enhanced to address these challenges. First, it was modified to accept high-resolution surface mass balance forcings. Second, a parameterization for basal drainage (of the sort responsible for sustaining the Northeast Greenland Ice Stream) was incorporated into the model. The enhanced model was used to investigate the century to millennial-scale evolution of the Greenland Ice Sheet in response to persistent climate trends. During initial experiments, the mechanism of flow in the outlet glaciers was assumed to be independent of climate change, and the outlet glaciers' dominant behavior was to counteract changes in surface mass balance. Around much of the ice sheet, warming resulted in calving front retreat and reduction of total ice sheet discharge. Observations show, however, that the character of outlet glacier flow changes with the climate. The ice sheet model was further developed to simulate observed dynamical responses of Greenland's outlet glaciers. A phenomenological description of the relation between outlet glacier discharge and surface mass balance was calibrated against recent observations. This model was used to investigate the ice sheet's response to a hypothesized 21st century warming trend. Enhanced discharge accounted for a 60% increase in Greenland mass loss, resulting in a net sea level increment of 7.3 cm by year 2100. By this time, the average surface mass balance had become negative, and widespread marginal thinning had caused 30% of historically active calving fronts to retreat. Mass losses persisted throughout the century due to flow of dynamically responsive outlets capable of sustaining high calving rates. Thinning in these areas propagated upstream into higher elevation catchments. Large drainage basins with low-lying outlets, especially those along Greenland's west coast and those fed by the Northeast Greenland Ice Stream, were most susceptible to dynamic mass loss in the 21st century

Includes bibliographical references. ; Mode of access: Internet.

"June 1994"--T.p. verso. ; Cover title. ; Includes bibliographical references. ; Mode of access: Internet.

According to a report by the World Bank published in April 2018, air pollution in Tehran incurs annual loss of billions of dollars and over 4,000 premature deaths from exposure to fine particles ambient concentrations. Particulate matter (PM), one of the primary pollutants from diesel exhaust, is associated with many different types of respiratory and cardiovascular effects, and premature mortality. The main objective of this study is to evaluate the cost effectiveness of retrofitting existing city diesel bus fleet in Tehran with best available Diesel particulate filters (DPFs) available in the market. The report provides an updated assessment on the diesel retrofit solutions for an ageing diesel city bus fleet in Tehran based on publicly available information. The economic benefits of DPF installed in buses are evaluated with standard techniques of environmental economics, and technological assumptions about how much PM emissions can be avoided and control costs. The report highlights a number of national, regional and local examples of effective emission control program that exhibit best practices from around the world. Also, it presents important features and global experiences of successful retrofit program on heavy-duty diesel vehicles (HDDVs), including benefit-cost analysis from several case studies to help Tehran city leadership in taking informed economic and policy decisions. Finally, it recommends a set of critical actions to the government both at the national and local level for implementation of an effective emission control programs.

Shipping list no.: 95-0048-P. ; Distributed to some depository libraries in microfiche. ; Includes bibliographical references. ; Microform. ; Mode of access: Internet.