Contractor point of view for system development and test program

Industry's practice of testing space qualified hardware is examined. An overview of the Global Positioning System (GPS) Test Program is discussed from the component level to the sub-system compatibility tests with the space vehicle and finally to the launch site tests, all related to the Rubidium clock

Rubidium and cesium frequency standards status and performance on the GPS program

The on-oribt operational performance of the frequency standards on the Global Positioning System (GPS) 1 to 10 NAVSTAR satellites are discussed. The history of the Rb frequency standards showing the improvements incorporated at various stages of the program and the corresponding results are presented. Also presented is the operational history of the NAVSTAR cesium frequency standards. The frequency standards configuration data presented covers the chronology of events from the concept validation satellites, NAVSTAR 1 to 10, starting in 1978 to the present, including the configurations of clocks to be used on the GPS Production Program. Data are presented showing the results of long-term laboratory testing of a production Rb frequency standard with the necessary data taken to calculate Delta F, drift, time error, and Allan variance

Production of gaseous fuel by pyrolysis of municipal solid waste

Pilot plant tests were conducted on a simulated solid waste which was a mixture of shredded newspaper, wood waste, polyethylene plastics, crushed glass, steel turnings, and water. Tests were conducted at 1400 F in a lead-bath pyrolyser. Cold feed was deaerated by compression and was dropped onto a moving hearth of molten lead before being transported to a sealed storage container. About 80 percent of the feed's organic content was converted to gaseous products which contain over 90 percent of the potential waste energy; 12 percent was converted to water; and 8 percent remained as partially pyrolyzed char and tars. Nearly half of the carbon in the feed is converted to benzene, toluene and medium-quality fuel gas, a potential credit of over $25 per ton of solid waste. The system was shown to require minimal preprocessing and less sorting then other methods

Enhancement of Transition Temperature in FexSe0.5Te0.5 Film via Iron Vacancies

The effects of iron deficiency in FexSe0.5Te0.5 thin films (0.8<x<1) on superconductivity and electronic properties have been studied. A significant enhancement of the superconducting transition temperature (TC) up to 21K was observed in the most Fe deficient film (x=0.8). Based on the observed and simulated structural variation results, there is a high possibility that Fe vacancies can be formed in the FexSe0.5Te0.5 films. The enhancement of TC shows a strong relationship with the lattice strain effect induced by Fe vacancies. Importantly, the presence of Fe vacancies alters the charge carrier population by introducing electron charge carriers, with the Fe deficient film showing more metallic behavior than the defect-free film. Our study provides a means to enhance the superconductivity and tune the charge carriers via Fe vacancy, with no reliance on chemical doping.Comment: 15 pages, 4 figure

The genealogy of judgement: towards a deep history of academic freedom

The classical conception of academic freedom associated with Wilhelm von Humboldt and the rise of the modern university has a quite specific cultural foundation that centres on the controversial mental faculty of 'judgement'. This article traces the roots of 'judgement' back to the Protestant Reformation, through its heyday as the signature feature of German idealism, and to its gradual loss of salience as both a philosophical and a psychological concept. This trajectory has been accompanied by a general shrinking in the scope of academic freedom from the promulgation of world-views to the offering of expert opinion

College Students Experiencing Homelessness: The Consequence of Failed Macro Policies

Homelessness among college students is a growing trend, yet the problem is difficult to document due to the stigma associated with the circumstance. Flaws in policies related to jobs and wages, affordable housing, and affordable education interact to increase the risks faced by economically vulnerable students who enter college without secure housing, or who lose it during the course of their studies. A concerted institutional response is needed to mitigate both the risks and the consequences of homelessness, and to reduce the numbers of U.S. college students whose educational attainment is compromised by housing insecurity

Innovative Sexually Transmitted Infection Prevention-Intervention for African-American Adolescent Girls

The purpose of this study is to determine whether implementation of an innovative STI prevention intervention design affects participants’ knowledge of sexually transmitted infections and sexual self-efficacy. The population this research focuses on is African-American adolescent girls. The participants included in this study are aged 13-19. This particular population is disproportionately infected by sexually transmitted diseases, so it is vital that intervention programs be tailored to fit their culture and gender-specific needs in order to achieve maximum results. However, current interventions for African-American girls could be improved. The researcher has designed an innovative STI prevention intervention that draws from current, best evidence interventions. The researcher has hypothesized that: (1) participants that complete the intervention will have increased STI knowledge; and, (2) upon completion of the intervention, participants will have greater sexual self-efficacy

QCD resummation in hadron production

We present calculations of next-to-leading order and resummed QCD corrections for semi-inclusive deep-inelastic scattering and single-inclusive e+e− annihilation. The resummation is performed to next-to-leading logarithmic accuracy. Knowing these QCD corrections is important in order to extract parton distribution functions and fragmentation functions from present and future data for these reactions. We present phenomenological results relevant for the COMPASS, HERMES, and BELLE experiments