3,087 research outputs found

    Identification and Environmental Assessments for Different Scenarios of Repurposed Decommissioned Wind Turbine Blades

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    The rapidly growing wind industry poses a fundamental problem for wind turbine blade (WTB) disposal in many areas of the world. WTBs are primarily manufactured from composites consisting of a thermoset matrix and reinforcing fibers. Currently, there are no economically viable recycling technologies available for such large-scale composite products. Thus, other treatment strategies for disposed WTBs have to be considered. This study explores the repurpose of WTBs as a promising alternative approach from a processual and technological point of view. For this purpose, the study is guided by the categorization into four different types of repurposed applications: high-loaded complete structure (T1), low-loaded complete structure (T2), high-loaded segmented structure (T3), and low-loaded segmented structure (T4). A three-dimensional CAD model of an Enercon-40/500 (E40) wind turbine blade is derived in a reverse engineering procedure to obtain knowledge about the actual geometry of the WTB. Based on the design, three ecosystems of product scenarios (S) with different manufacturing technologies involved are investigated: a climbing tower (S1), a playground (S2) and the combination of a photovoltaic (PV)-floating pontoon, and a lounger (S3). A screening life cycle assessment (LCA) is conducted to evaluate the three repurposed scenarios according to environmental aspects. It is shown that the repurpose of E40 WTB composite material can reduce the environmental impact and leads to significant resource savings in relation to a reference product of similar quality. A particularly high saving potential is identified for the substitution of emission-intensive materials in construction applications. Furthermore, it is found that transport processes are the primary contributor to the environmental impact of repurposed applications

    Protocol for the 'e-Nudge trial' : a randomised controlled trial of electronic feedback to reduce the cardiovascular risk of individuals in general practice [ISRCTN64828380]

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    Background: Cardiovascular disease (including coronary heart disease and stroke) is a major cause of death and disability in the United Kingdom, and is to a large extent preventable, by lifestyle modification and drug therapy. The recent standardisation of electronic codes for cardiovascular risk variables through the United Kingdom's new General Practice contract provides an opportunity for the application of risk algorithms to identify high risk individuals. This randomised controlled trial will test the benefits of an automated system of alert messages and practice searches to identify those at highest risk of cardiovascular disease in primary care databases. Design: Patients over 50 years old in practice databases will be randomised to the intervention group that will receive the alert messages and searches, and a control group who will continue to receive usual care. In addition to those at high estimated risk, potentially high risk patients will be identified who have insufficient data to allow a risk estimate to be made. Further groups identified will be those with possible undiagnosed diabetes, based either on elevated past recorded blood glucose measurements, or an absence of recent blood glucose measurement in those with established cardiovascular disease. Outcome measures: The intervention will be applied for two years, and outcome data will be collected for a further year. The primary outcome measure will be the annual rate of cardiovascular events in the intervention and control arms of the study. Secondary measures include the proportion of patients at high estimated cardiovascular risk, the proportion of patients with missing data for a risk estimate, and the proportion with undefined diabetes status at the end of the trial

    An update on the global use of risk assessment models and thromboprophylaxis in hospitalized patients with medical illnesses from the World Thrombosis Day steering committee: Systematic review and meta-analysis

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    INTRODUCTION Venous thromboembolism (VTE) is a leading cause of cardiovascular morbidity and mortality. The majority of VTE events are hospital-associated. In 2008, the Epidemiologic International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting (ENDORSE) multinational cross-sectional study reported that only approximately 40% of medical patients at risk of VTE received adequate thromboprophylaxis. METHODS In our systematic review and meta-analysis, we aimed at providing updated figures concerning the use of thromboprophylaxis globally. We focused on: (a) the frequency of patients with an indication to thromboprophylaxis according with individual models; (b) the use of adequate thromboprophylaxis; and (c) reported contraindications to thromboprophylaxis. Observational nonrandomized studies or surveys focusing on medically ill patients were considered eligible. RESULTS After screening, we included 27 studies from 20 countries for a total of 137 288 patients. Overall, 50.5% (95% confidence interval [CI]: 41.9-59.1, I2^{2} 99%) of patients had an indication to thromboprophylaxis: of these, 54.5% (95% CI: 46.2-62.6, I2^{2} 99%) received adequate thromboprophylaxis. The use of adequate thromboprophylaxis was 66.8% in Europe (95% CI: 50.7-81.1, I2^{2} 98%), 44.9% in Africa (95% CI: 31.8-58.4, I2^{2} 96%), 37.6% in Asia (95% CI: 25.7-50.3, I2^{2} 97%), 58.3% in South America (95% CI: 31.1-83.1, I2^{2} 99%), and 68.6% in North America (95% CI: 64.9-72.6, I2^{2} 96%). No major differences in adequate thromboprophylaxis use were found across risk assessment models. Bleeding, thrombocytopenia, and renal/hepatic failure were the most frequently reported contraindications to thromboprophylaxis. CONCLUSIONS The use of anticoagulants for VTE prevention has been proven effective and safe, but thromboprophylaxis prescriptions are still unsatisfactory among hospitalized medically ill patients around the globe with marked geographical differences

    Rasiowa–Sikorski deduction systems in computer science applications

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    AbstractA Rasiowa-Sikorski system is a sequence-type formalization of logics. The system uses invertible decomposition rules which decompose a formula into sequences of simpler formulae whose validity is equivalent to validity of the original formula. There may also be expansion rules which close indecomposable sequences under certain properties of relations appearing in the formulae, like symmetry or transitivity. Proofs are finite decomposition trees with leaves having “fundamental”, valid labels. The author describes a general method of applying the R-S formalism to develop complete deduction systems for various brands of C.S and A.I. logic, including a logic for reasoning about relative similarity, a three-valued software specification logic with McCarthy's connectives and Kleene quantifiers, a logic for nondeterministic specifications, many-sorted FOL with possibly empty carriers of some sorts, and a three-valued logic for reasoning about concurrency

    Elevated gamma glutamyl transferase levels are associated with the location of acute pulmonary embolism. Cross-sectional evaluation in hospital setting

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    ABSTRACT CONTEXT AND OBJECTIVE: The location of embolism is associated with clinical findings and disease severity in cases of acute pulmonary embolism. The level of gamma-glutamyl transferase increases under oxidative stress-related conditions. In this study, we investigated whether gamma-glutamyl transferase levels could predict the location of pulmonary embolism. DESIGN AND SETTING: Hospital-based cross-sectional study at Cumhuriyet University, Sivas, Turkey. METHODS : 120 patients who were diagnosed with acute pulmonary embolism through computed tomography-assisted pulmonary angiography were evaluated. They were divided into two main groups (proximally and distally located), and subsequently into subgroups according to thrombus localization as follows: first group (thrombus in main pulmonary artery; n = 9); second group (thrombus in main pulmonary artery branches; n = 71); third group (thrombus in pulmonary artery segmental branches; n = 34); and fourth group (thrombus in pulmonary artery subsegmental branches; n = 8). RESULTS : Gamma-glutamyl transferase levels on admission, heart rate, oxygen saturation, right ventricular dilatation/hypokinesia, pulmonary artery systolic pressure and cardiopulmonary resuscitation requirement showed prognostic significance in univariate analysis. The multivariate logistic regression model showed that gamma-glutamyl transferase level on admission (odds ratio, OR = 1.044; 95% confidence interval, CI: 1.011-1.079; P = 0.009) and pulmonary artery systolic pressure (OR = 1.063; 95% CI: 1.005-1.124; P = 0.033) remained independently associated with proximally localized thrombus in pulmonary artery. CONCLUSIONS : The findings revealed a significant association between increased existing embolism load in the pulmonary artery and increased serum gamma-glutamyl transferase levels

    Are hospitals delivering appropriate VTE prevention? The venous thromboembolism study to assess the rate of thromboprophylaxis (VTE start)

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    The 7th conference of the American College of Chest Physicians (ACCP7) provides recommendations on the type, dose, and duration of thromboprophylaxis in hospitalized patients at risk of venous thromboembolism (VTE), but the extent to which hospitals follow these criteria has not been well studied. Discharge and billing records for patients admitted to any of 16 acute-care hospitals from January 2005 to December 2006 were obtained. Patients 18 years or older who had an inpatient stay ≥2 days and no apparent contraindications for thromboprophylaxis were grouped into the categories of critical care, surgery and medically ill before being assessed for additional VTE risk factors based on the diagnostic criteria outlined in ACCP7. For patients at risk, the recommended type (mechanical or pharmacologic), dose, and duration of thromboprophylaxis was identified based on the guidelines and compared to the regimen actually received, if any. Among the 258,556 hospitalized patients, 68,278 (26.4%) were determined to be at risk of VTE without apparent contraindications for thromboprophylaxis. The proportions of patients who received the appropriate type, dose, and duration of thromboprophylaxis were 10.5, 9.8, and 17.9% for critical care, medical, and surgical patients, respectively. Of those at risk, 36.8% received no thromboprophylaxis and an additional 50.2% received thromboprophylaxis deemed inappropriate for one or more reasons. The implementation of ACCP7 guidelines for type, dosage, and duration of thromboprophylaxis is low in patients at risk of VTE. There is a need for physicians and health systems to improve awareness and implementation of recommended thromboprophylaxis
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