1,089 research outputs found

    Electron diffraction studies of pulsed cluster beams

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    A pulsed nozzle source has been installed in the electron diffraction unit at the University of Michigan. The pulsed mode of operation is found to offer several important advantages in the investigation of clusters generated in nozzle flow. These advantages, including the feasibility of operating without a skimmer, are discussed. Design features and characteristic results are briefly outlined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43899/1/10053_2005_Article_BF01426894.pd

    Dermal Exposure to Jet Fuel JP-8 Significantly Contributes to the Production of Urinary Naphthols in Fuel-Cell Maintenance Workers

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    Jet propulsion fuel 8 (JP-8) is the major jet fuel used worldwide and has been recognized as a major source of chemical exposure, both inhalation and dermal, for fuel-cell maintenance workers. We investigated the contributions of dermal and inhalation exposure to JP-8 to the total body dose of U.S. Air Force fuel-cell maintenance workers using naphthalene as a surrogate for JP-8 exposure. Dermal, breathing zone, and exhaled breath measurements of naphthalene were obtained using tape-strip sampling, passive monitoring, and glass bulbs, respectively. Levels of urinary 1- and 2-naphthols were determined in urine samples and used as biomarkers of JP-8 exposure. Multiple linear regression analyses were conducted to investigate the relative contributions of dermal and inhalation exposure to JP-8, and demographic and work-related covariates, to the levels of urinary naphthols. Our results show that both inhalation exposure and smoking significantly contributed to urinary 1-naphthol levels. The contribution of dermal exposure was significantly associated with levels of urinary 2-naphthol but not with urinary 1-naphthol among fuel-cell maintenance workers who wore supplied-air respirators. We conclude that dermal exposure to JP-8 significantly contributes to the systemic dose and affects the levels of urinary naphthalene metabolites. Future work on dermal xenobiotic metabolism and toxicokinetic studies are warranted in order to gain additional knowledge on naphthalene metabolism in the skin and the contribution to systemic exposure

    The Men's Safer Sex (MenSS) trial: protocol for a pilot randomised controlled trial of an interactive digital intervention to increase condom use in men

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    Sexually transmitted infections (STI) are a major public health problem. Condoms provide effective protection but there are many barriers to use. Face-to-face health promotion interventions are resource-intensive and show mixed results. Interactive digital interventions may provide a suitable alternative, allowing private access to personally tailored behaviour change support. We have developed an interactive digital intervention (the Men's Safer Sex (MenSS) website) which aims to increase condom use in men. We describe the protocol for a pilot trial to assess the feasibility of a full-scale randomised controlled trial of the MenSS website in addition to usual sexual health clinical care

    Intercomparison of Nine Micrometeorological Stations during the BEAREX08 Field Campaign

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    Land–atmosphere interactions play a critical role in regulating numerous meteorological, hydrological, and environmental processes. Investigating these processes often requires multiple measurement sites representing a range of surface conditions. Before these measurements can be compared, however, it is imperative that the differences among the instrumentation systems are fully characterized. Using data collected as a part of the 2008 Bushland Evapotranspiration and Agricultural Remote Sensing Experiment (BEAREX08), measurements from nine collocated eddy covariance (EC) systems were compared with the twofold objective of 1) characterizing the interinstrument variation in the measurements, and 2) quantifying the measurement uncertainty associated with each system. Focusing on the three turbulent fluxes (heat, water vapor, and carbon dioxide), this study evaluated the measurement uncertainty using multiple techniques. The results of the analyses indicated that there could be substantial variability in the uncertainty estimates because of the advective conditions that characterized the study site during the afternoon and evening hours. However, when the analysis was limited to nonadvective, quasi-normal conditions, the response of the nine EC stations were remarkably similar. For the daytime period, both the method of Hollinger and Richardson and the method of Mann and Lenschow indicated that the uncertainty in the measurements of sensible heat, latent heat, and carbon dioxide flux were approximately 13 W m‒2, 27 W m‒2, and 0.10 mg m‒2 s‒1, respectively. Based on the results of this study, it is clear that advection can greatly increase the uncertainty associated with EC flux measurements. Since these conditions, as well as other phenomena that could impact the measurement uncertainty, are often intermittent, it may be beneficial to conduct uncertainty analyses on an ongoing basis

    The argument of the broken pane: Suffragette consumerism and newspapers

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    Within the cut-throat world of newspaper advertising the newspapers of Britain's Women's Social and Political Union (WSPU) Votes for Women and the Suffragette managed to achieve a balance that has often proved to be an impossible challenge for social movement press—namely the maintenance of a highly political stance whilst simultaneously exploiting the market system with advertising and merchandising. When the militant papers advocated window smashing of West End stores in 1912–1913, the companies who were the target still took advertisements. Why? What was the relationship between news values, militant violence and advertising income? ‘Do-it-yourself’ journalism operated within a context of ethical consumerism and promotionally orientated militancy. This resulted in newspaper connections between politics, commerce and a distinct market profile, evident in the customisation of advertising, retailer dialogue with militants and longer-term loyalty—symptomatic of a wider trend towards newspaper commercialism during this period

    Análise do envolvimento dos conselhos de administração na gestão estratégica

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    This study analyzes the involvement of boards of directors in strategic management. Through a survey of 36 Brazilian companies affiliated with the Brazilian Institute of Corporate Governance, we intend to analyze the factors that determine the degree of involvement of boards of directors in strategic decisions. Three dimensions were focused: which strategic decisions are under the boards' responsibility; which criteria are used to determine the optimum involvement of the board; and to what degree boards centralize strategic decisions. Results showed that boards are increasing their involvement in different types of strategic decisions, not limiting themselves to monitoring and controlling the company. Also, boards will tend to reach a balance when it comes to centralization of authority, sharing decisions with top managers and acting like counselors in the strategic management process.Este estudio analiza la relación de los consejos de administración con la gestión estratégica. A partir de un levantamiento con 36 empresas brasileñas afiliadas con el Instituto Brasileño de Gobernanza Corporativa, fueron analizados los factores que determinan el grado de relación de los consejeros en las decisiones estratégicas. Fueron abordadas tres dimensiones: cuáles decisiones están bajo la responsabilidad del consejo; cuáles criterios determinan el grado óptimo de relación del consejo; y en qué medida los consejos centralizan las decisiones estratégicas. Los resultados mostraron que los consejos están aumentando su relación en diferentes tipos de decisiones estratégicas, no limitándose solamente a monitorear y controlar la empresa. Además, los mismos buscan un equilibrio al centralizar la autoridad, dividiendo las decisiones importantes con la alta administración y con actuación en el proceso de aconsejamiento.Este estudo analisa o envolvimento dos conselhos de administração na gestão estratégica. A partir de um levantamento com 36 empresas brasileiras afiliadas com o Instituto Brasileiro de Governança Corporativa, foram analisados os fatores que determinam o grau de envolvimento dos conselheiros nas decisões estratégicas. Foram abordadas três dimensões: quais decisões estão sob a responsabilidade do conselho; quais critérios determinam o grau ótimo de envolvimento do conselho; e em que medida os conselhos centralizam as decisões estratégicas. Os resultados mostraram que os conselhos estão aumentando seu envolvimento em diferentes tipos de decisões estratégicas, não se limitando a monitorar e controlar a empresa. Além disso, eles buscam um equilíbrio ao centralizar a autoridade, dividindo decisões importantes com a alta administração e agindo no processo de aconselhamento

    Coastal saltmarsh managed realignment drives rapid breach inlet and external creek evolution, Freiston Shore (UK)

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    The creation of saltmarsh through the managed realignment of sea defences, implemented in NW Europe as a sustainable coastal defence option, represents a substantial hydrodynamic perturbation to the local coastal system. The impact of a significantly increased tidal prism on hydromorphological features was investigated at Freiston Shore, Lincolnshire UK. Local tidal conditions and inadequate drainage at this realignment trial contributed to significant channel erosion due to the establishment of water surface slopes and pooling between the newly realigned site and the adjacent intertidal zone. Very high spatial resolution aerial photography and blimp photography were used to monitor inlet evolution from breaching in August 2002 to March 2008, showing a highly non-linear response with breach channels increasing in width by up to 960% within 2.5. months. Airborne laser scanning/LiDAR and terrestrial laser scanning quantified breach channel volume increases, showing a similar pattern. Breach channel evolution did not follow established tidal prism-channel width/cross-sectional area relationships that are often used to guide realignment design. Pre- and post-breach rates of external creek morphology change between 1999 and 2006 were also quantified, with intertidal creeks attached to the breach channels increasing significantly after realignment in both width and depth. This study highlights the physical processes affected by managed realignment, and the importance of understanding the causes of complex water surface slopes at multiple scales. © 2013 Elsevier B.V
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