1,744 research outputs found

    Creation of a ceramics handbook

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    A group of common ceramic materials (alumina, magnesium oxide, silicon nitride, and silicon carbide) were characterized through literature searches according to their physical properties. The files used were the NASA file, DDC/GRA File, Engineering Index File and standard library searches. The results of these searches are arranged by material properties including mechanical, electrical, electromagnetic, where applicable, and fracture; and the entries are arranged in chronological order by candidate. A list, by author, follows where tabular information including charts and figures of results is given along with a brief statement of the results and conclusions. In both cases, information on the independent variables along with their range is given. The results of an extensive industry survey asking for names of other candidates on which information is lacking and also what type of service, if any, is desired in keeping a current information file on general ceramic materials

    Creation of a ceramics handbook

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    A study was conducted to develop a ceramics handbook defining properties and parameters necessary for thermostructural design. Continuing efforts toward this goal, and in particular toward the evolution of a reliable predictor of fracture from current literature, are described

    The effects of lightning on digital flight control systems

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    Present practices in lightning protection of aircraft deal primarily with the direct effects of lightning, such as structural damage and ignition of fuel vapors. There is increasing evidence of troublesome electromagnetic effects, however, in aircraft employing solid-state microelectronics in critical navigation, instrumentation and control functions. The potential impact of these indirect effects on critical systems such as digital fly-by-wire (DFBW) flight controls has been studied by several recent research programs, including an experimental study of lightning-induced voltages in the NASA F8 DFBW airplane. The results indicate a need for positive steps to be taken during the design of future fly-by-wire systems to minimize the possibility of hazardous effects from lightning

    Incidence and survival for cancer in children and young adults in the North of England, 1968–1995: a report from the Northern Region Young Persons’ Malignant Disease Registry

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    The Northern Region Young Persons’ Malignant Disease Registry records information on young people under 25 years old diagnosed with cancer in the Northern Region of England. Incidence and survival rates were calculated for children and young adults diagnosed with cancer between 1968 and 1995. There were 2099 (M:F 1.28:1) children (age 0–14 years) and 2217 (M:F 1.23:1) young adults (15–24 years) diagnosed with a first cancer between 1968 and 1995. The age-standardized rate (ASR) for childhood cancer was 121 per million 0 to 14 year-olds per year. For young adults the ASR was 175 per million 15 to 24 year-olds, per year. Incidence of childhood cancer increased over time at a rate of 12 extra cases per million children, per decade (P< 0.001). In young adults incidence rates increased by 16 extra cases per million 15 to 24 year-olds, per decade (P< 0.001). For childhood cancer 5-year survival was 42% for those diagnosed 1968–1977, 57% for 1978–1987 and 71% (95% CI 67–75) for 1988–1995. Survival for young adults over the three periods was 45%, 62% and 73% (95% CI 70–78) respectively. The cumulative risk of developing cancer before the age of 25 is 1 in 285. Over the 28-year period there were significant improvements in survival and modest increases in incidence in both children and young adults. © 2000 Cancer Research Campaig
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