84 research outputs found

    An algorithm to generate input data from meteorological and space shuttle observations to validate a CH4-CO model

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    Objective procedures to analyze data from meteorological and space shuttle observations to validate a three dimensional model were investigated. The transport and chemistry of carbon monoxide and methane in the troposphere were studied. Four aspects were examined: (1) detailed evaluation of the variational calculus procedure, with the equation of continuity as a strong constraint, for adjustment of global tropospheric wind fields; (2) reduction of the National Meteorological Center (NMC) data tapes for data input to the OSTA-1/MAPS Experiment; (3) interpolation of the NMC Data for input to the CH4-CO model; and (4) temporal and spatial interpolation procedures of the CO measurements from the OSTA-1/MAPS Experiment to generate usable contours of the data

    Production of Anhydrous 1,4-Dioxane

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    This invention relates to the production of anhydrous 1,4-dioxane by the dimerization of ethylene oxide in the presence of an acidic type of cation exchanger, preferably an acidic cation exchanger resin having sulfonic acid groups associated therewith. The 1,4-dioxane is formed by contacting ethylene oxide in the liquid phase with an acidic-type cation exchanger at a first temperature and for a time sufficient to yield a reaction product of the ethylene oxide and the cation exchanger, and thereafter heating the reaction product at a second temperature higher than the first temperature and for a time period sufficient to dissociate the reaction product and thereby yield 1,4-dioxane

    Geographic and social influences on HIV risk behavior among urban young men in Tanzania

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    Introduction: In Sub-Saharan Africa, over six million youth ages 15-24 are living with HIV. One promising HIV prevention strategy for youth is to target high risk sexual networks in the places where they socialize. High risk sexual networks are characterized in part by concurrent sexual partnerships. This study described the prevalence of and associated risk factors for having concurrent partnerships among a sample of young men in Tanzania, and qualitatively described the venues in which these young men socialize. Methods: The PLACE (priorities for local AIDS control efforts) method was applied in one ward of Dar es Salaam. Interviews with community informants identified eighty-three venues where young men were known to meet new sexual partners. In sixty-seven of these venues a cross-sectional survey was conducted with 671 men ages 15-19 to describe their sexual partnerships. Observations (n=23) and in-depth interviews (n=46) were conducted at twenty-four purposively selected venues to describe their physical and social features. Results: Half of all sexually active men in the sample engaged in at least one concurrent partnership within the past six months. Men who reported symptoms of sexually transmitted infections were twice as likely to have engaged in a concurrent partnership as those who reported no symptoms (95% CI: 1.62-2.77). Factors that increased the likelihood of concurrency included early sexual debut, attendance at multiple venues, not sleeping at parents' home the night before the interview, and alcohol use within sexual partnerships. Qualitative results described the venues in which these men met new sexual partners. The majority of the venues (86%) were known as camps, social gathering places for youth that required membership. The camp environment facilitated risky behaviors, including drinking alcohol. Healthy behaviors were promoted among camp members through camp leadership, strong social ties and income-generating activities. Conclusions: Young men reported a high prevalence of concurrent sexual partnerships. The camps where young men socialize have both risk and therapeutic features that influence men's behaviors. Program implications include enhancing the role of camps in promoting healthy behaviors and addressing concurrent partnerships as part of the constellation of risk behaviors that place youth at risk for HIV

    KINETICS OF THE TRANSESTERIFICATION REACTIONS OF DIMETHYL-TEREPHTHALATE WITH ETHYLENE GLYCOL.

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    Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1975 .Y24. Source: Dissertation Abstracts International, Volume: 36-02, Section: B, page: 0834. Thesis (Ph.D.)--University of Windsor (Canada), 1975

    Solid Oxide Fuel Cell APU Feasibility Study for a Long Range Commercial Aircraft Using UTC ITAPS Approach

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    The objective of this contract effort was to define the functionality and evaluate the propulsion and power system benefits derived from a Solid Oxide Fuel Cell (SOFC) based Auxiliary Power Unit (APU) for a future long range commercial aircraft, and to define the technology gaps to enable such a system. The study employed technologies commensurate with Entry into Service (EIS) in 2015. United Technologies Corporation (UTC) Integrated Total Aircraft Power System (ITAPS) methodologies were used to evaluate system concepts to a conceptual level of fidelity. The technology benefits were captured as reductions of the mission fuel burn and emissions. The baseline aircraft considered was the Boeing 777-200ER airframe with more electric subsystems, Ultra Efficient Engine Technology (UEET) engines, and an advanced APU with ceramics for increased efficiency. In addition to the baseline architecture, four architectures using an SOFC system to replace the conventional APU were investigated. The mission fuel burn savings for Architecture-A, which has minimal system integration, is 0.16 percent. Architecture-B and Architecture-C employ greater system integration and obtain fuel burn benefits of 0.44 and 0.70 percent, respectively. Architecture-D represents the highest level of integration and obtains a benefit of 0.77 percent

    Leveraging strong social ties among young men in Dar es Salaam: A pilot intervention of microfinance and peer leadership for HIV and gender-based violence prevention

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    Gender inequality is at the core of the HIV patterns that are evident in sub-Saharan Africa. Gender-based violence (GBV) and lack of economic opportunity are important structural determinants of HIV risk. We piloted a microfinance and health promotion intervention among social networks of primarily young men in Dar es Salaam. Twenty-two individuals participated in the microfinance component and 30 peer leaders were recruited and trained in the peer health leadership component. We collected and analyzed observational data from trainings, monitoring data on loan repayment, and reports of peer conversations to assess the feasibility and acceptability of the intervention. Eighteen of the loan recipients (82%) paid back their loans, and of these 15 (83%) received a second, larger loan. Among the loan defaulters, one died, one had chronic health problems, and two disappeared, one of whom was imprisoned for theft. The majority of conversations reported by peer health leaders focused on condoms, sexual partner selection and HIV testing. Few peer leaders reported conversations about GBV. We demonstrated the feasibility and acceptability of this innovative HIV and GBV prevention intervention. The lessons learned from this pilot have informed the implementation of a cluster-randomized trial of the microfinance and peer health leadership intervention

    Evidence of social network influence on multiple HIV risk behaviors and normative beliefs among young Tanzanian men

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    Research on network-level influences on HIV risk behaviors among young men in sub-Saharan Africa is severely lacking. One significant gap in the literature that may provide direction for future research with this population is understanding the degree to which various HIV risk behaviors and normative beliefs cluster within men’s social networks. Such research may help us understand which HIV-related norms and behaviors have the greatest potential to be changed through social influence. Additionally, few network-based studies have described the structure of social networks of young men in sub-Saharan Africa. Understanding the structure of men’s peer networks may motivate future research examining the ways in which network structures shape the spread of information, adoption of norms, and diffusion of behaviors. We contribute to filling these gaps by using social network analysis and multilevel modeling to describe a unique dataset of mostly young men (n= 1,249 men and 242 women) nested within 59 urban social networks in Dar es Salaam, Tanzania. We examine the means, ranges, and clustering of men’s HIV-related normative beliefs and behaviors. Networks in this urban setting varied substantially in both composition and structure and a large proportion of men engaged in risky behaviors including inconsistent condom use, sexual partner concurrency, and intimate partner violence perpetration. We found significant clustering of normative beliefs and risk behaviors within these men’s social networks. Specifically, network membership explained between 5.78 and 7.17% of variance in men’s normative beliefs and between 1.93 and 15.79% of variance in risk behaviors. Our results suggest that social networks are important socialization sites for young men and may influence the adoption of norms and behaviors. We conclude by calling for more research on men’s social networks in Sub-Saharan Africa and map out several areas of future inquiry

    Jet fuel based high pressure solid oxide fuel cell system

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    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both

    Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

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    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both
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