Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final Report. Volume III: Silicon sheet: wafers and ribbons

The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development. The primary objective of the Silicon Sheet Task of the FSA Project was the development of one or more low-cost technologies for producing silicon sheet suitable for processing into cost-eompetitive solar cells. Silicon sheet refers to high-purity crystalline silicon of size and thickness for fabrication into solar cells. The Task effort began with state-of-the-art sheet technologies and then solicited and supported any new silicon sheet alternatives that had the potential to achieve the Project goals. A total of 48 contracts were awarded that covered work in the areas of ingot growth and casting, wafering, ribbon growth, other sheet technologies, and programs of supportive research. Periodic reviews of each sheet technology were held, assessing the technical progress and the long-range potential. Technologies that failed to achieve their promise, or seemed to have lower probabilities for success in comparison with others, were dropped. A series of workshops was initiated to assess the state of the art, to provide insights into problems remaining to be addressed, and to support technology transfer. The Task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high-quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the Task cost goals were not achieved. This FSA Final Report (JPL Publication 86-31, 5101-289, DOE/JPL 1012-125, October 1986) is composed of eight volumes, consisting of an Executive Summary and seven technology reports: Volume I: Executive Summary. Volume II: Silicon Material. Volume III: Silicon Sheet: Wafers and Ribbons Volume IV: High-Efficiency Solar Celis. Volume V: Process Development. Volume VI: Engineering Sciences and Reliability. Volume VII: Module Encapsulation. Volume VIII: Project Analysis and Integration. Two supplemental reports included in the final report package are: FSA Project: 10 Years of Progress, JPL Document 400-279. 5101-279, October 1985. Summary of FSA Project Documentation: Abstracts of Published Documents, 1975 to 1986, JPL Publication 82-79 (Revision 1),5101-221, DOE/JPL-1 012-76, September 1986

Cost of Czochralski wafers as a function of diameter

The impact of diameter in the range of 10 to 15 cm on the cost of wafers sliced from Czochralski ingots was analyzed. Increasing silicon waste and decreasing ingot cost with increasing ingot size were estimated along with projected costs. Results indicate a small but continuous decrease in sheet cost with increasing ingot size in this size range. Sheet costs including silicon are projected to be $50 to$60/sq m (1980 $) depending upon technique used

Mechanical behavior of polycrystalline ceramics: Brittle fracture of SiC-Si3N4 materials

The first study area involved magnesium oxide and the role of anion impurities, while the second area was directed toward slow crack growth in silicon nitride-silicon carbide ceramics. The oxide program involved development of fabrication techniques for anion doped materials and evaluation of the role of these anions in the hot pressing response, grain boundary diffusion of nickel doped material, grain boundary microhardness, and grain growth

The Impact of Joinder and Severance on Federal Criminal Cases: An Empirical Study

Dave is in trouble. It was bad enough to be arrested for bank robbery; now he has learned that the prosecutor plans to join the current charge with three other, unrelated bank robberies and present all four counts in a single trial. To his priest and to his lawyer, Dave admits that he committed the first and the second robberies, but he did not commit the third or fourth. Dave is smart enough to realize, however, that once the jury starts hearing evidence of some of the crimes-all of which will sound quite similar-his ability to cast doubt on the remaining charges will be dimmed. And Dave\u27s lawyer is smart enough to know that once the charges are joined, the chances of splitting them apart are relatively small. It is widely assumed that criminal defendants who face multiple charges in a single trial have a harder time prevailing than those who face several trials of one count each. Conventional wisdom also has it that a defendant who is joined for trial with other suspects is in a worse position than one who stands trial alone. These assumptions have never been tested empirically; this Article tries to fill the gap. Looking at nearly 20,000 federal criminal trials over a five-year period, the Article asks if the traditional beliefs are true and, if so, tries to measure the impact on trial outcomes of joining counts and defendants. The effect of joinder on criminal cases is part of a larger debate about how best to manage a growing criminal docket while still providing individual justice. The battle lines are easy to describe: courts and prosecutors typically want joined proceedings, defendants usually don\u27t. Courts believe that consolidated proceedings play a vital role \u27 in the administration of justice; defendants believe that they are a source of great prejudice. The problem is that both sides are right. The details of joinder and severance law are dry, even boring, and perhaps as a result, the impact of consolidated trials has received little scholarly attention. But the consequences are widespread: more than half of all federal defendants are charged with multiple counts, roughly one-third are joined with other defendants, and an overlapping one-quarter face both-a single proceeding with multiple charges plus one or more co-defendants. If joinder makes a conviction significantly more likely, it should have a bearing on prosecutors\u27 charging decisions, judicial rulings on severance motions, and defense decisions on whether to plead or stand trial. More importantly, understanding the dimensions of any prejudice should tell us something important about the tradeoffs we make between fairness to the accused and efficiency in processing criminal cases. Part II provides some background and describes the risks created by joinder. Part III(A) sets forth some working hypotheses and then offers an original empirical case for the prejudicial impact of joinder on the defense. Part III(B) then tests the empirical case with statistical models, trying to control for various features besides joinder that might explain the differences in trial outcome. To preview the results: it turns out that there is a measurable and significant prejudicial effect from joining multiple counts in a single trial, but the impact of joining multiple defendants is far less clear. With the results of the empirical test in hand, Part 1V argues for a reconsideration of the competing interests and poses questions for future study

Flat-plate solar array project. Volume 3: Silicon sheet: Wafers and ribbons

The primary objective of the Silicon Sheet Task of the Flat-Plate Solar Array (FSA) Project was the development of one or more low cost technologies for producing silicon sheet suitable for processing into cost-competitive solar cells. Silicon sheet refers to high purity crystalline silicon of size and thickness for fabrication into solar cells. Areas covered in the project were ingot growth and casting, wafering, ribbon growth, and other sheet technologies. The task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the task cost goals were not achieved

Pygomelia or supernumerary limbs in a crossbred calf

A crossbred (Sindhi × local indigenous) calf that was 12 days old was admitted to the Teaching Veterinary Hospital, Chittagong Government Veterinary College, Bangladesh, with two accessory hind limbs attached to the pelvic region in between the hind legs. This was clinically identified as a congenital anomaly popularly called pygomelia. The pygomelia was successfully corrected by surgical excisions

Designing displaced lunar orbits using low-thrust propulsion

The design of spacecraft trajectories is a crucial task in space mission design. Solar sail technology appears as a promising form of advanced spacecraft propulsion which can enable exciting new space science mission concepts such as solar system exploration and deep space observation. Although solar sailing has been considered as a practical means of spacecraft propulsion only relatively recently, the fundamental ideas are by no means new (see McInnes1 for a detailed description). A solar sail is propelled by re ecting solar photons and therefore can transform the momentum of the photons into a propulsive force. This article focuses on designing displaced lunar orbits using low-thrust propulsion

Mechanical behavior of polycrystalline ceramics: Brittle fracture of Si C - Si3N4 materials

The results are described of the final stage of the research involving the role of anions in the behavior of magnesium oxide, as well as the continued efforts of the fracture behavior of silicon nitride materials. These efforts, particularly the first, are further sub-divided in subsections describing individual types of behavior of materials