26 research outputs found

    SnBrP-A SnIP-type representative in the Sn-Br-P system

    Get PDF
    One-dimensional semiconductors are interesting materials due to their unique structural features and anisotropy, which grant them intriguing optical, dielectric and mechanical properties. In this work, we report on SnBrP, a lighter homologue of the first inorganic double helix compound SnIP. This class of compounds is characterized by intriguing mechanical and electronic properties, featuring a high flexibility without modulation of physical properties. Semiconducting SnBrP can be synthesized from red phosphorus, tin and tin(II)bromide at elevated temperatures and crystallizes as red-orange, cleavable needles. Raman measurements pointed towards a double helical building unit in SnBrP, showing similarities to the SnIP structure. After taking PL measurements, HR-TEM, and quantum chemical calculations into account, we were able to propose a sense full structure model for SnBrP

    Containment structures and port configurations

    Get PDF
    This article describes the DEMO cryostat, the vacuum vessel, and the tokamak building as well as the system configurations to integrate the main in-vessel components and auxiliary systems developed during the Pre-Conceptual Design Phase. The vacuum vessel is the primary component for radiation shielding and containment of tritium and other radioactive material. Various systems required to operate the plasma are integrated in its ports. The vessel together with the external magnetic coils is located inside the even larger cryostat that has the primary function to provide a vacuum to enable the operation of the superconducting coils in cryogenic condition. The cryostat is surrounded by a thick concrete structure: the bioshield. It protects the external areas from neutron and gamma radiation emitted from the tokamak. The tokamak building layout is aligned with the VV ports implementing floors and separate rooms, so-called port cells, that can be sealed to provide a secondary confinement when a port is opened during in-vessel maintenance. The ports of the torus-shaped VV have to allow for the replacement of in-vessel components but also incorporate plasma limiters and auxiliary heating and diagnostic systems. The divertor is replaced through horizontal ports at the lower level, the breeding blanket (BB) through upper vertical ports. The pipe work of these in-vessel components is also routed through these ports. To facilitate the vertical replacement of the BB, it is divided into large vertical segments. Their mechanical support during operation relies on vertically clamping them inside the vacuum vessel by a combination of obstructed thermal expansion and radial pre-compression due to the ferromagnetic force acting on the breeding blanket structural material in the toroidal magnetic field

    Physiological modeling, tight glycemic control, and the ICU clinician: what are models and how can they affect practice?

    Get PDF
    Critically ill patients are highly variable in their response to care and treatment. This variability and the search for improved outcomes have led to a significant increase in the use of protocolized care to reduce variability in care. However, protocolized care does not address the variability of outcome due to inter- and intra-patient variability, both in physiological state, and the response to disease and treatment. This lack of patient-specificity defines the opportunity for patient-specific approaches to diagnosis, care, and patient management, which are complementary to, and fit within, protocolized approaches

    Automatic classification of manual snow profiles by snow structure

    Get PDF
    Manual snowpack observations are an important component of avalanche hazard assessment for the Swiss avalanche forecasting service. Approximately 900 snow profiles are observed each winter, in flat study plots or on representative slopes. So far, these profiles have been manually classified combining both information on snow stability (e.g. Rutschblock test) and snowpack structure (e.g. layering, hardness). To separate the classification of snowpack stability and structure, and also to reduce inconsistencies in ratings between forecasters, we developed and tested an automatic approach to classify profiles by snowpack structure during two winters. The automatic classification is based on a calculated index, which consists of three components: properties of (1) the slab (thickness), (2) weakest layer interface and (3) the percentage of the snowpack which is soft, coarse-grained and consists of persistent grain types. The latter two indices are strongly based on criteria described in the threshold sum approach. The new snowpack structure index allows a consistent comparison of snowpack structure to detect regional patterns, seasonal or inter-annual differences but may also supplement snow-climate classifications

    Point observations of liquid water content in wet snow – investigating methodical, spatial and temporal aspects

    No full text
    Information about the volume and the spatial and temporal distribution of liquid water in snow is important for forecasting wet snow avalanches and for predicting melt-water run-off. The distribution of liquid water in snow is commonly estimated from point measurements using a "hand" squeeze test, or a dielectric device such as a "Snow Fork" or a "Denoth meter". Here we compare estimates of water content in the Swiss Alps made using the hand test to those made with a Snow Fork and a Denoth meter. Measurements were conducted in the Swiss Alps, mostly above tree line; more than 12 000 measurements were made at 85 locations over 30 days. Results show that the hand test generally over estimates the volumetric liquid water content. Estimates using the Snow Fork are generally 1 % higher than those derived from the Denoth meter. The measurements were also used to investigate temporal and small-scale spatial patterns of wetness. Results show that typically a single point measurement does not characterize the wetness of the surrounding snow. Large diurnal changes in wetness are common in the near-surface snow, and associated changes at depth were also observed. A single vertical profile of measurements is not sufficient to determine whether these changes were a result of a spatially homogeneous wetting front or caused by infiltration through pipes. Based on our observations, we suggest that three measurements at horizontal distances greater than 50 cm are needed to adequately characterize the distribution of liquid water through a snowpack. Further, we suggest a simplified classification scheme that includes five wetness patterns that incorporate both the vertical and horizontal distribution of liquid water in a snowpack

    An <i>in silico</i> method to identify computer-based protocols worthy of clinical study:an insulin infusion protocol use case

    No full text
    Objective Develop an efficient non-clinical method for identifying promising computer-based protocols for clinical study. An in silico comparison can provide information that informs the decision to proceed to a clinical trial. The authors compared two existing computer-based insulin infusion protocols: eProtocol-insulin from Utah, USA, and Glucosafe from Denmark. Materials and Methods The authors used eProtocol-insulin to manage intensive care unit (ICU) hyperglycemia with intravenous (IV) insulin from 2004 to 2010. Recommendations accepted by the bedside clinicians directly link the subsequent blood glucose values to eProtocol-insulin recommendations and provide a unique clinical database. The authors retrospectively compared in silico 18 984 eProtocol-insulin continuous IV insulin infusion rate recommendations from 408 ICU patients with those of Glucosafe, the candidate computer-based protocol. The subsequent blood glucose measurement value (low, on target, high) was used to identify if the insulin recommendation was too high, on target, or too low. Results Glucosafe consistently provided more favorable continuous IV insulin infusion rate recommendations than eProtocol-insulin for on target (64% of comparisons), low (80% of comparisons), or high (70% of comparisons) blood glucose. Aggregated eProtocol-insulin and Glucosafe continuous IV insulin infusion rates were clinically similar though statistically significantly different (Wilcoxon signed rank test P = .01). In contrast, when stratified by low, on target, or high subsequent blood glucose measurement, insulin infusion rates from eProtocol-insulin and Glucosafe were statistically significantly different (Wilcoxon signed rank test, P < .001), and clinically different. Discussion This in silico comparison appears to be an efficient nonclinical method for identifying promising computer-based protocols. Conclusion Preclinical in silico comparison analytical framework allows rapid and inexpensive identification of computer-based protocol care strategies that justify expensive and burdensome clinical trials

    Increases and decreases in marine disease reports in an era of global change

    No full text
    Outbreaks of marine infectious diseases have caused widespread mass mortalities, but the lack of baseline data has precluded evaluating whether disease is increasing or decreasing in the ocean. We use an established literature proxy method from Ward and Lafferty (Ward and Lafferty 2004 PLoS Biology2, e120 (doi:10.1371/journal.pbio.0020120)) to analyse a 44-year global record of normalized disease reports from 1970 to 2013. Major marine hosts are combined into nine taxonomic groups, from seagrasses to marine mammals, to assess disease swings, defined as positive or negative multi-decadal shifts in disease reports across related hosts. Normalized disease reports increased significantly between 1970 and 2013 in corals and urchins, indicating positive disease swings in these environmentally sensitive ectotherms. Coral disease reports in the Caribbean correlated with increasing temperature anomalies, supporting the hypothesis that warming oceans drive infectious coral diseases. Meanwhile, disease risk may also decrease in a changing ocean. Disease reports decreased significantly in fishes and elasmobranchs, which have experienced steep human-induced population declines and diminishing population density that, while concerning, may reduce disease. The increases and decreases in disease reports across the 44-year record transcend short-term fluctuations and regional variation. Our results show that long-term changes in disease reports coincide with recent decades of widespread environmental change in the ocean
    corecore