912 resultados para fault current limiter
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Three standard radiation qualities (RQA 3, RQA 5 and RQA 9) and two screens, Kodak Lanex Regular and Insight Skeletal, were used to compare the imaging performance and dose requirements of the new Kodak Hyper Speed G and the current Kodak T-MAT G/RA medical x-ray films. The noise equivalent quanta (NEQ) and detective quantum efficiencies (DQE) of the four screen-film combinations were measured at three gross optical densities and compared with the characteristics for the Kodak CR 9000 system with GP (general purpose) and HR (high resolution) phosphor plates. The new Hyper Speed G film has double the intrinsic sensitivity of the T-MAT G/RA film and a higher contrast in the high optical density range for comparable exposure latitude. By providing both high sensitivity and high spatial resolution, the new film significantly improves the compromise between dose and image quality. As expected, the new film has a higher noise level and a lower signal-to-noise ratio than the standard film, although in the high frequency range this is compensated for by a better resolution, giving better DQE results--especially at high optical density. Both screen-film systems outperform the phosphor plates in terms of MTF and DQE for standard imaging conditions (Regular screen at RQA 5 and RQA 9 beam qualities). At low energy (RQA 3), the CR system has a comparable low-frequency DQE to screen-film systems when used with a fine screen at low and middle optical densities, and a superior low-frequency DQE at high optical density.
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BACKGROUND: In recent years several trials have addressed treatment challenges in Crohn's disease. Clinical trials however, represent a very special situation. AIMS: To perform a cross-sectional survey among gastroenterologists on the current clinical real life therapeutic approach focussing on the use of biologics. METHODS: A survey including six main questions on clinical management of loss of response, diagnostic evaluation prior to major treatment changes, preference for anti-tumour necrosis factor (TNF) agent, (de-)escalation strategies as well as a basic section regarding personal information was sent by mail to all gastroenterologists in Switzerland (n=318). RESULTS: In total, 120 questionnaires were analysed (response rate 37.7%). 90% of gastroenterologists in Switzerland use a thiopurine as the first step-up strategy (anti-TNF alone 7.5%, combination 2.5%). To address loss of response, most physicians prefer shortening the interval of anti-TNF administration followed by dose increase, switching the biologic and adding a thiopurine. In case of prolonged remission on combination therapy, the thiopurine is stopped first (52.6%) after a mean treatment duration of 15.7 months (biologic first in 41.4%). CONCLUSIONS: Everyday clinical practice in Crohn's disease patients appears to be incongruent with clinical data derived from major trials. Studies investigating reasons underlying these discrepancies are of need to optimize and harmonize treatment.
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The Quaternary Active Faults Database of Iberia (QAFI) is an initiative lead by the Institute of Geology and Mines of Spain (IGME) for building a public repository of scientific data regarding faults having documented activity during the last 2.59 Ma (Quaternary). QAFI also addresses a need to transfer geologic knowledge to practitioners of seismic hazard and risk in Iberia by identifying and characterizing seismogenic fault-sources. QAFI is populated by the information freely provided by more than 40 Earth science researchers, storing to date a total of 262 records. In this article we describe the development and evolution of the database, as well as its internal architecture. Aditionally, a first global analysis of the data is provided with a special focus on length and slip-rate fault parameters. Finally, the database completeness and the internal consistency of the data are discussed. Even though QAFI v.2.0 is the most current resource for calculating fault-related seismic hazard in Iberia, the database is still incomplete and requires further review.
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This article reports on a project at the Universitat Oberta de Catalunya (UOC: The Open University of Catalonia, Barcelona) to develop an innovative package of hypermedia-based learning materials for a new course entitled 'Current Issues in Marketing'. The UOC is a distance university entirely based on a virtual campus. The learning materials project was undertaken in order to benefit from the advantages which new communication technologies offer to the teaching of marketing in distance education. The article reviews the main issues involved in incorporating new technologies in learning materials, the development of the learning materials, and their functioning within the hypermedia based virtual campus of the UOC. An empirical study is then carried out in order to evaluate the attitudes of students to the project. Finally, suggestions for improving similar projects in the future are put forward.
A Survey on Detection Techniques to Prevent Cross-Site Scripting Attacks on Current Web Applications
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RATIONALE, AIMS AND OBJECTIVES: There is little evidence regarding the benefit of stress ulcer prophylaxis (SUP) outside a critical care setting. Overprescription of SUP is not devoid of risks. This prospective study aimed to evaluate the use of proton pump inhibitors (PPIs) for SUP in a general surgery department. METHOD: Data collection was performed prospectively during an 8-week period on patients hospitalized in a general surgery department (58 beds) by pharmacists. Patients with a PPI prescription for the treatment of ulcers, gastro-oesophageal reflux disease, oesophagitis or epigastric pain were excluded. Patients admitted twice during the study period were not reincluded. The American Society of Health-System Pharmacists guidelines on SUP were used to assess the appropriateness of de novo PPI prescriptions. RESULTS: Among 255 patients in the study, 138 (54%) received a prophylaxis with PPI, of which 86 (62%) were de novo PPI prescriptions. A total of 129 patients (94%) received esomeprazole (according to the hospital drug policy). The most frequent dosage was at 40 mg once daily. Use of PPI for SUP was evaluated in 67 patients. A total of 53 patients (79%) had no risk factors for SUP. Twelve and two patients had one or two risk factors, respectively. At discharge, PPI prophylaxis was continued in 33% of patients with a de novo PPI prescription. CONCLUSIONS: This study highlights the overuse of PPIs in non-intensive care unit patients and the inappropriate continuation of PPI prescriptions at discharge. Treatment recommendations for SUP are needed to restrict PPI use for justified indications.
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Both "early" (< 16 weeks' gestation) and "late" (> 26 weeks' gestation) presentations of twin-twin transfusion syndrome (TTTS) are rare and challenging complications of monochorionic/diamniotic twin pregnancies. Growing evidence suggests that fetoscopic laser therapy for both "early" and "late" TTTS is feasible, safe, and yields similar outcomes to cases treated between 16 and 26 weeks' gestation. We suggest reevaluation of conventional gestational age guidelines for laser therapy for TTTS.
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The research of condition monitoring of electric motors has been wide for several decades. The research and development at universities and in industry has provided means for the predictive condition monitoring. Many different devices and systems are developed and are widely used in industry, transportation and in civil engineering. In addition, many methods are developed and reported in scientific arenas in order to improve existing methods for the automatic analysis of faults. The methods, however, are not widely used as a part of condition monitoring systems. The main reasons are, firstly, that many methods are presented in scientific papers but their performance in different conditions is not evaluated, secondly, the methods include parameters that are so case specific that the implementation of a systemusing such methods would be far from straightforward. In this thesis, some of these methods are evaluated theoretically and tested with simulations and with a drive in a laboratory. A new automatic analysis method for the bearing fault detection is introduced. In the first part of this work the generation of the bearing fault originating signal is explained and its influence into the stator current is concerned with qualitative and quantitative estimation. The verification of the feasibility of the stator current measurement as a bearing fault indicatoris experimentally tested with the running 15 kW induction motor. The second part of this work concentrates on the bearing fault analysis using the vibration measurement signal. The performance of the micromachined silicon accelerometer chip in conjunction with the envelope spectrum analysis of the cyclic bearing faultis experimentally tested. Furthermore, different methods for the creation of feature extractors for the bearing fault classification are researched and an automatic fault classifier using multivariate statistical discrimination and fuzzy logic is introduced. It is often important that the on-line condition monitoring system is integrated with the industrial communications infrastructure. Two types of a sensor solutions are tested in the thesis: the first one is a sensor withcalculation capacity for example for the production of the envelope spectra; the other one can collect the measurement data in memory and another device can read the data via field bus. The data communications requirements highly depend onthe type of the sensor solution selected. If the data is already analysed in the sensor the data communications are needed only for the results but in the other case, all measurement data need to be transferred. The complexity of the classification method can be great if the data is analysed at the management level computer, but if the analysis is made in sensor itself, the analyses must be simple due to the restricted calculation and memory capacity.
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Chemotherapy given in a metronomic manner can be administered with less adverse effects which are common with conventional schedules such as myelotoxicity and gastrointestinal toxicity and thus may be appropriate for older patients and patients with decreased performance status. Efficacy has been observed in several settings. An opportunity to improve the efficacy of metronomic schedules without significantly increasing toxicity presents with the addition of anti-angiogenic targeted treatments. These combinations rational stems from the understanding of the importance of angiogenesis in the mechanism of action of metronomic chemotherapy which may be augmented by specific targeting of the vascular endothelial growth factor (VEGF) pathway by antibodies or small tyrosine kinase inhibitors. Combinations of metronomic chemotherapy schedules with VEGF pathway targeting drugs will be discussed in this paper.
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QUESTIONS UNDER STUDY: The field of heart transplantation has seen substantial progress in the last 40 years. The breakthroughs in long-term survival were followed by a period of stagnation in the last decade. This review summarises current recommendations for the identification of candidates for heart transplantation and their immunological and non-immunological postoperative follow-up. RESULTS: The progress made in the treatment of patients with advanced heart failure has considerably changed the profile of candidates for heart transplantation. Patients are older, and the load of co-morbidities is more important requiring careful evaluation for candidacy. Long-standing research in the field of immunosuppression made available various drugs, which decrease the risk of acute allograft rejection and prolong survival after heart transplantation. Powerful new molecules are entering early phase clinical studies, suggesting further improvement in the near future. As a consequence, treatment of non-immunological co-morbidity after heart transplantation will gain in importance, however, the base of evidence guiding current recommendations is poor. CONCLUSIONS: The substantial progress in heart failure treatment and immunosuppression after heart transplantation has changed the profile of heart transplant recipients. The arrival of new molecules will provide additional alternatives for immunosuppressive treatment while studies have to address non-immunological treatment in order to improve long-term survival after heart transplantation.