2,269 research outputs found

    Graduate Education in Airport Administration: Preparing Airport Managers for the 21st Century

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    Growing numbers of students pursuing management careers in aviation are seeking graduate degrees to prepare for the complex and evolving challenges in the aviation industry. This study questioned members of the American Association of Airport Executives (AAAE) about their profession and the appropriateness of current education opportunities in aviation administration. The purpose of this study was to identify the knowledge and skills that the next generation of airport administrators will need to effectively contend with the new industrial environment

    Antarctica Meta-Analysis: Psychosocial Factors Related to Long Duration Isolation and Confinement

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    This meta-analysis is examining the psychological effects of wintering-over in Antarctica. As an isolated, confined, and extreme (ICE) environment, Antarctica provides invaluable opportunities to experience stressors more common to spaceflight than to the average person s everyday life. Increased prevalence of psychological symptoms, syndromes, and psychiatric disorders, as well as positive effects, are expected to be associated with various demographic and environmental factors. Implications for spaceflight are discussed. Findings from statistical review of the Antarctic articles will be shared

    GENESIS OF DONGPING GOLD-TELLURIDE DEPOSIT BASED ON GEOCHEMICAL CHARACTERISTICS OF FLUIDS, 40Ar/39Ar DATING, STABLE AND RADIOGENIC ISOTOPES (NORTH CHINA)

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    The Dongping goldfield is located within the Shuiquangou alkaline complex of the western Yanshan Mountains of Hebei Province, on the northern margin of the North China Craton. It is one of the largest gold deposits in China, with a planned gold production of 2.57 tons annually over a lifespan of 12 years. The Dongping gold deposit is enriched in the elements Au, Te, Ag, Pb, Bi, Sb and As. Most of the gold is present in the telluride minerals calaverite (43% Au, 38% Ag) and petzite (23% Au, 46% Ag). Gold mineralization is hosted mainly by K-feldspar-quartz stockworks, veins and disseminated sulfides. The deposit contains three ore types that are distinguished by their mineral associations: vein quartz gold, telluride gold, and disseminated gold. The paragenesis of the ores exhibits three distinct hydrothermal stages, of which the second one was the main ore-enrichment stage. The ore-related 40Ar/39Ar ages determined on K-feldspar samples indicate two episodes of gold mineralization, at 154.89 ± 0.70 Ma and 176.93 ± 4.66 Ma. The gold mineralization ages thus postdate the Devonian-age granite intrusion but overlap possible JurassicCretaceous magmatic activity. The homogenization temperatures of the majority of inclusions range from 120 to 240°C and from 240 to 400°C. The inclusions in quartz veins are CO2-rich and characterized by low salinity (average 6.0–8.8 wt% NaCl eq.). The laser Raman spectrum of the inclusions shows that the fluid compositions are dominantly waterrich but also contain CO2. The hydrogen isotope compositions (δ2H) of the fluid inclusions range from ‒100.3 to ‒66.5 ‰, and the calculated oxygen isotope compositions (δ18O) for source fluids range from ‒0.3 to +6.9 ‰ "Standard Mean Ocean Water" (SMOW). These values indicate that the ore-forming fluid came from a deep magmatic hydrothermal system, with involvement of meteoric water and possibly water affected by organic matter. The sulphur isotope compositions (δ34S) of pyrite are mainly from ‒0.3 to ‒13.6 ‰ Vienna Cañon Diablo Troilite (VCDT), suggesting homogeneity of sulphur in the magmatic source with subsequent fractionation under relatively oxidizing conditions in ore-bearing quartz veins. The relationship of δ2HH2O to 87Sr/86Sr indicates that the fluid inclusions and host granitoid rocks were influenced by mixing of magmatic and meteoric waters. Key words: Chongli county; Dongping deposit; 40Ar/39Ar dating; stable and radiogenic isotopes; ore-forming fluids; gold deposit; North Chin

    Comparison between two mobile absolute gravimeters: optical versus atomic interferometers

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    We report a comparison between two absolute gravimeters: the LNE-SYRTE cold atoms gravimeter and FG5#220 of Leibniz Universit\"at of Hannover. They rely on different principles of operation: atomic and optical interferometry. Both are movable which enabled them to participated to the last International Comparison of Absolute Gravimeters (ICAG'09) at BIPM. Immediately after, their bilateral comparison took place in the LNE watt balance laboratory and showed an agreement of 4.3 +/- 6.4 {\mu}Gal

    Reconciling Incongruous Qualitative and Quantitative Findings in Mixed Methods Research: Exemplars from Research with Drug Using Populations

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    Mixed methods research is increasingly being promoted in the health sciences as a way to gain more comprehensive understandings of how social processes and individual behaviours shape human health. Mixed methods research most commonly combines qualitative and quantitative data collection and analysis strategies. Often, integrating findings from multiple methods is assumed to confirm or validate the findings from one method with the findings from another, seeking convergence or agreement between methods. Cases in which findings from different methods are congruous are generally thought of as ideal, whilst conflicting findings may, at first glance, appear problematic. However, the latter situation provides the opportunity for a process through which apparently discordant results are reconciled, potentially leading to new emergent understandings of complex social phenomena. This paper presents three case studies drawn from the authors’ research on HIV risk amongst injection drug users in which mixed methods studies yielded apparently discrepant results. We use these case studies (involving injection drug users [IDUs] using a Needle/Syringe Exchange Program in Los Angeles, CA, USA; IDUs seeking to purchase needle/syringes at pharmacies in Tijuana, Mexico; and young street-based IDUs in San Francisco, CA, USA) to identify challenges associated with integrating findings from mixed methods projects, summarize lessons learned, and make recommendations for how to more successfully anticipate and manage the integration of findings. Despite the challenges inherent in reconciling apparently conflicting findings from qualitative and quantitative approaches, in keeping with others who have argued in favour of integrating mixed methods findings, we contend that such an undertaking has the potential to yield benefits that emerge only through the struggle to reconcile discrepant results and may provide a sum that is greater than the individual qualitative and quantitative parts
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