1,098 research outputs found

    Performance of a local electron density trigger to select extensive air showers at sea level

    Get PDF
    Time coincident voltage pulses in the two closely space (1.6m) plastic scintillators were recorded. Most of the recorded events are expeted to be due to electrons in cosmic ray showers whose core fall at some distance from the detectors. This result is confirmed from a measurement of the frequency distribution of the recorded density ratios of the two scintillators

    Intelligent reconfiguration of large mobile networks using complex organic distributed architecture

    Get PDF
    This paper presents a possible solution to the intelligent evolution of mobile systems using a Complex Organic Distributed Architecture (CODA), which supports intelligent reconfiguration of all system components. A key feature of this architecture is the deployment of multiple warehouses. The warehouses store data in a variety of ways depending on the type of intelligence required. On Line Analytical Processing (OLAP) software is used to monitor and control data in the system. An effective system of filters and wrappers ensures that data is secure. A system of feedback loops ensures that information travels through the system quickly and effectively

    Equilibre agro-sylvo-pastoral Massif des Beni Salah (Algérie).

    Get PDF

    Self-affine surface morphology of plastically deformed metals

    Full text link
    We analyze the surface morphology of metals after plastic deformation over a range of scales from 10 nm to 2 mm, using a combination of atomic force microscopy and scanning white-light interferometry. We demonstrate that an initially smooth surface during deformation develops self-affine roughness over almost four orders of magnitude in scale. The Hurst exponent HH of one-dimensional surface profiles is initially found to decrease with increasing strain and then stabilizes at H0.75H \approx 0.75. By analyzing their statistical properties we show that the one-dimensional surface profiles can be mathematically modelled as graphs of a fractional Brownian motion. Our findings can be understood in terms of a fractal distribution of plastic strain within the deformed samples

    Vulnerability analysis of satellite-based synchronized smart grids monitoring systems

    Get PDF
    The large-scale deployment of wide-area monitoring systems could play a strategic role in supporting the evolution of traditional power systems toward smarter and self-healing grids. The correct operation of these synchronized monitoring systems requires a common and accurate timing reference usually provided by a satellite-based global positioning system. Although these satellites signals provide timing accuracy that easily exceeds the needs of the power industry, they are extremely vulnerable to radio frequency interference. Consequently, a comprehensive analysis aimed at identifying their potential vulnerabilities is of paramount importance for correct and safe wide-area monitoring system operation. Armed with such a vision, this article presents and discusses the results of an experimental analysis aimed at characterizing the vulnerability of global positioning system based wide-area monitoring systems to external interferences. The article outlines the potential strategies that could be adopted to protect global positioning system receivers from external cyber-attacks and proposes decentralized defense strategies based on self-organizing sensor networks aimed at assuring correct time synchronization in the presence of external attacks

    Coronary slow flow: Benign or ominous?

    Get PDF
    Objective: Coronary slow flow phenomenon has been arbitrarily defined as delayed coronary blood flow in the absence of obstructive coronary artery disease. The present study sought to investigate the clinical features, natural history, and outcomes of affected patients. Methods: In this prospective cross-sectional study, 217 consecutive patients who had undergone coronary angiography and showed features of coronary slow flow phenomenon were evaluated for demographic and coronary risk factor profile, as well as clinical outcomes, at baseline and following treatment. Results: The study population consisted of 165 (76) males and 52 (24) females. The mean age of patients was 52.6±10 years. Mean ejection fraction was 48.2±5.4, 39.3 had diabetes, 43.3 had hypertension, 49.8 was a cigarette smoker, 41.9 had dyslipidemia, and 15 had a familial history of cardiac disease. Forty-nine percent was detected to have abnormal hsCRP levels. The most prevalent presenting complaint was atypical chest pain. Fifty-four percent of patients had slow blood flow in all three vessels. Thirty-six people had undergone repeat coronary angiography in a follow-up period of 5-7 years due to persisting or worsening clinical symptoms, of whom 6 (16.6) showed significant coronary artery stenosis. Eight (22.2) had mild CAD, and the rest still showed coronary slow flow without significant stenosis. The most common complaint during follow-up and after initiation of medical therapy was nonanginal chest pain. Conclusion: Patients with coronary slow flow phenomenon are predisposed to atherosclerosis and obstructive coronary artery disease. Therefore, this pathology should not be considered as a totally benign condition. Primary and secondary cardiovasculature preventive measures should be constituted and seem worthwhile in this patient population. © Copyright 2015 by Turkish Society of Cardiology

    Increasing the number of embryos transferred from two to three, does not increase pregnancy rates in good prognosis patients

    Get PDF
    Background: To compare the pregnancy outcomes after two embryos versus three embryos transfers (ETs) in women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles. Materials and Methods: This retrospective study was performed on three hundred eighty seven women with primary infertility and with at least one fresh embryo in good quality in order to transfer at each IVF/ICSI cycle, from September 2006 to June 2010. Patients were categorized into two groups according to the number of ET as follows: ET2 and ET3 groups, indicating two and three embryos were respectively transferred. Pregnancy outcomes were compared between ET2 and ET3 groups. Chi square and student t tests were used for data analysis. Results: Clinical pregnancy and live birth rates were similar between two groups. The rates of multiple pregnancies were 27 and 45.2 in ET2 and ET3 groups, respectively. The rate of multiple pregnancies in young women was significantly increased when triple instead of double embryos were transferred. Logistic regression analysis indicated two significant prognostic variables for live birth that included number and quality of transferred embryos; it means that the chance of live birth following ICSI treatment increased 3.2-fold when the embryo with top quality (grade A) was transferred, but the number of ET had an inverse relationship with live birth rate; it means that probability of live birth in women with transfer of two embryos was three times greater than those who had three ET. Conclusion: Due to the difficulty of implementation of the elective single-ET technique in some infertility centers in the world, we suggest transfer of double instead of triple embryos when at least one good quality embryo is available for transfer in women aged 39 years or younger. However, to reduce the rate of multiple pregnancies, it is recommended to consider the elective single ET strategy. � 2015, Royan Institute (ACECR). All rights reserved

    Comparison of different stimulation protocols efficacy in poor responders undergoing IVF: A retrospective study

    Get PDF
    Purpose: To compare the efficacy of different stimulation protocols on pregnancy outcomes in poor responders undergoing in vitro fertilization (IVF). Materials and methods: This was a retrospective study to compare the efficacy of four different protocols including gonadotropin-releasing hormone (GnRH) agonist (long, short and miniflare) and GnRH antagonist on pregnancy outcomes in poor responders. This investigation was performed on 566 poor respond patients who were candidates for IVF. Main outcome measures included the total number of oocytes and mature oocytes retrieved, pregnancy rates, implantation and overall cancellation rates which were compared between four mentioned groups. Results: Number of follicles >18mm on hCG day were significantly higher in GnRH-a long versus GnRH antagonist, GnRH-a short and GnRH-a miniflare protocols. The mean number of oocytes and mature oocytes retrieved were significantly higher in GnRH-a long versus miniflare (4.7±3.05 versus 3.26±2.9 and 3.69±3.1 versus 2.65±2.2, respectively). There were no significant differences in implantation, pregnancy and overall cancellation rates between four groups. Conclusion: The present study suggests that the application of four different protocols in poor respond patients seem to have similar efficacy in improving clinical outcomes such as implantation, pregnancy rates and cancellation rate even though GnRH-a long protocol yielded more retrieved oocytes and mature oocytes compared to GnRH-a miniflare protocol. © 2012 Informa UK, Ltd
    corecore