1,021 research outputs found

    Absolute 1* quantum yields for the ICN A state by diode laser gain versus absorption spectroscopy

    Get PDF
    Absolute I* quantum yields were measured as a function of wavelength for room temperature photodissociation of the ICN A state continuum. The temperature yields are obtained by the technique of time-resolved diode laser gain-versus-absorption spectroscopy. Quantum yields are evaluated at seven wavelengths from 248 to 284 nm. The yield at 266 nm is 66.0 +/- 2% and it falls off to 53.4 +/- 2% and 44.0 +/- 4% at 284 and 248 respectively. The latter values are significantly higher than those obtained by previous workers using infrared fluorescence. Estimates of I* quantum yields obtained from analysis of CN photofragment rotational distributions, as discussed by other workers, are in good agreement with the I* yields. The results are considered in conjunction with recent theoretical and experimental work on the CN rotational distributions and with previous I* yield results

    Bone mineral density in resistance trained premenopausal females

    Get PDF
    The purpose of this study was to compare the effects of chronic resistance training on bone mineral density (BMD) in resistance trained and sedentary premenopausal females. [This is an excerpt from the abstract. For the complete abstract, please see the document.

    Transforming Ourselves, Transforming the World: Justice in Jesuit Higher Education

    Get PDF
    Review of Transforming Ourselves, Transforming the World: Justice in Jesuit Higher Education

    Professional Skills and Values in Legal Education: The GPS Model

    Get PDF

    Analysis and Insights from a Dynamical Model of Nuclear Plant Safety Risk

    Get PDF
    In this paper, we expand upon previously reported results of a dynamical systems model for the impact of plant processes and programmatic performance on nuclear plant safety risk. We utilize both analytical techniques and numerical simulations typical of the analysis of nonlinear dynamical systems to obtain insights important for effective risk management. This includes use of bifurcation diagrams to show that period doubling bifurcations and regions of chaotic dynamics can occur. We also investigate the impact of risk mitigating functions (equipment reliability and loss prevention) on plant safety risk and demonstrate that these functions are capable of improving risk to levels that are better than those that are represented in a traditional risk assessment. Next, we analyze the system response to the presence of external noise and obtain some conclusions with respect to the allocation of resources to ensure that safety is maintained at optimal levels. In particular, we demonstrate that the model supports the importance of management and regulator attention to plants that have demonstrated poor performance by providing an external stimulus to obtain desired improvements. Equally important, the model suggests that excessive intervention, by either plant management or regulatory authorities, can have a deleterious impact on safety for plants that are operating with very effective programs and processes. Finally, we propose a modification to the model that accounts for the impact of plant risk culture on process performance and plant safety risk. We then use numerical simulations to demonstrate the important safety benefits of a strong risk culture.Nonlinear Dynamical Systems, Process Model, Risk Management

    Sinonasal undifferentiated carcinoma of the maxillary sinus

    Get PDF
    We describe the case of a 43-year-old man who was referred to our dental school’s acute care clinic with pain and swelling of presumed dental origin in the left maxillary quadrant. Radiographic examination revealed extensive dental decay and periodontal disease. On questioning, the patient admitted to paresthesia of recent onset. Paresthesia associated with pain or swelling of the jaws is an ominous sign that should alert the clinician to the possibility of an underlying aggressive neoplasm. In this case, biopsy of the lesion confirmed that the patient had a rare malignant tumour of maxillary sinus origin,a sinonasal undifferentiated carcinoma

    Beryllium Biochemistry in a Forested Ecosystem

    Get PDF
    High rates of atmospheric deposition of beryllium are toxic biologically and are exacerbated by synergistic interaction with aluminum. The Czech Republic is experiencing growing problems, and similar consequences may well soon be experienced in Maine. An expert international research team would pursue parallel pilot studies into the biogeochemical controls on Be fate and transport by examining beryllium biogeochemistry in forested ecosystems. This project funds the work in Maine and travel for international collaboration; the Czechs are supporting the work in their country. The plan for the pilot study is to develop chemical time series for beryllium fluxes into, through, and out of watersheds in a paired study in the Bear Brook Watershed where one watersheds is being artificially acidified with ammonium sulfate. The study evaluates the fluxes of total BE and 7Be at the forest floor, leaving the watersheds, and in litter fall. Be in stream vegetation and sediment is being evaluated before and after acidic discharge events to assess temporary exchangeable pools
    • …
    corecore