485 research outputs found

    Nonlinearity in Single Photon Detection: Modeling and Quantum Tomography

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    Single Photon Detectors are integral to quantum optics and quantum information. Superconducting Nanowire based detectors exhibit new levels of performance, but have no accepted quantum optical model that is valid for multiple input photons. By performing Detector Tomography, we improve the recently proposed model [M.K. Akhlaghi and A.H. Majedi, IEEE Trans. Appl. Supercond. 19, 361 (2009)] and also investigate the manner in which these detectors respond nonlinearly to light, a valuable feature for some applications. We develop a device independent model for Single Photon Detectors that incorporates this nonlinearity

    Modeling the effects of high strain rate loading on RC columns using Arbitrary Lagrangian Eulerian (ALE) technique

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    In recent years, many studies have been conducted by governmental and nongovernmental organizations across the world in an attempt to better understand the effect of explosive loads on buildings in order to better design against specific threats. This study is intended to contribute to increase the knowledge about how explosions affect reinforced concrete (RC) columns. In this study, a nonlinear model is developed to study the blast response of RC columns subjected to explosive loads. Numerical modeling of RC column under explosive load is presented using advanced finite element code LS DYNA. The obtained numerical model is validated with the experimental test and the results are in substantial agreement with the experimental data. ALE method for blast analysis is presented in the current research. The effects of scaled distance on the damage profile of RC columns are investigated. The results demonstrate that the level of damage increased with describing the scaled distance. Also the results shown duration for the blast loading, and hence the impulse, varies with charge masses at the specified scaled distance. Higher magnitude charge masses produced longer blast loading durations than lower magnitude charge masses. This means that at the same scaled distance, a charge mass of higher magnitude produced a higher impulse than the lower magnitude charge mass. The findings of this research represent the scaled distance is an important parameter that should be taken into account when analyzing the behavior of RC columns under explosive effects. The data collected from this research are being used to improve the knowledge of how structures will respond to a blast event, and improve finite element models for predicting the blast performance of concrete structures.Peer Reviewe

    Epidemiology and the agreement rate of serological tests in human brucellosis in North East of Iran

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    Background: Brucellosis still remains a major health problem with different symptoms and various diagnostic methods. Diagnostic methods of brucellosis are usually based on detecting specific antibodies in the patient’s serum. Nowadays, many serological tests are applied for the diagnosis of human brucellosis. Most routine tests are serum agglutination tests based on Wright and 2-Mercaptoethanol (2-ME). Objectives: The aim of this study (cross sectional study) was to evaluate the prevalence of brucellosis and assess the degree of agreement among serum samples of suspected brucellosis serological tests routinely performed in Mashhad, Iran. Patients and Methods: This study was conducted in Mashhad from August 2011 to September 2012. Sera (2 - 3 mL) were collected from 83 cases suspected of brucellosis among 594 patients. Ten serum samples were collected from healthy subjects as control sera. Rose Bengal test for initial screening and Wright and 2 ME as standard tests were conducted to determine antibody titers. Thereafter, IgG and IgM levels were determined by the Enzyme Linked Immunosorbent Assay (ELISA) method. Results: Among 83 serum samples, Rose Bengal test was able to identify 20 (12%) positive specimens; the standard tube agglutination test was able to detect 30 (18%) positive samples, and the ELISA IgG and ELISA IgM were able to trace 42 (21%) and 13 (6.5%) positive samples, respectively. Ten control samples had negative results for the ELISA method. The results were calculated by the Kappa formula. The highest level of agreement was among 1 = KRB-SAT tests and the lowest level of agreement was among tests K ELISA IgM-IgG = 0.30. Conclusions: According to the results, brucellosis has remained endemic in this region. Most cases were detected by ELISA IgG. The highest kappa agreements were between tests KRB-SAT, KRB-IgG and KSAT-IgG, while the lowest levels of agreement were between tests SAT-IgM and ELISA IgM-IgG. Considering that ELISA IgM results are covered by SAT and ELISA IgG test results, applications of this test do not seem necessary. © 2015, Infectious Diseases and Tropical Medicine Research Center

    Efficient Single Photon Absorption by Optimized Superconducting Nanowire Geometries

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    We report on simulation results that shows optimum photon absorption by superconducting nanowires can happen at a fill-factor that is much less than 100%. We also present experimental results on high performance of our superconducting nanowire single photon detectors realized using NbTiN on oxidized silicon.Comment: \copyright 2013 IEEE. Submitted to "Numerical Simulation of Optoelectronic Devices - NUSOD 2013" on 19-April-201

    Observation on hydatid cyst infection in Kordestan province (West of Iran) using epidemiological and seroepidemiological criteria

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    Echinococcosis is the major helminthic parasitic infection in Iran. The health hazard and economic loss in man and livestock is significant. In this study 3 major topics as the prevalence of hydatid cyst in human population, in livestock and echinococcosis in stray dogs, were studied. Total of 1114 serum samples in different age groups in Sanandaj and Divandareh area of Kurdestan province in west of Iran were examined by indirect immunoflurecent test (IFA). In Sanandaj area 3.3 and in Divandareh 9.5 of serum samples were positive for hydatidosis. In livestock using abattoir inspection the rate of infection was 51.9 and 28.02 for sheep and cattle, respectively. Nine stray dogs (44) autopsied in Sanandaj were positive for Echinococcosis

    An investigation on the sustained releasing delivery of GnRHa using Freund's incomplete adjuvant in rainbow trout (Oncorhynchus mykiss)

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    In this study, Freund's incomplete adjuvant (FIA) was used for emulsifying and sustained releasing of gonadotropin releasing hormone agonist (GnRHa) in Rainbow trout (Oncorhynchus mykiss). The hormone [D-Ala6, des GlylO] m GnRHa was diluted in 0.25ml physiological saline and mixed with equal volume of FIA (GnRHa-FIA). A group of Rainbow trout broodstock were injected with GnRHa-FIA and compared with those receiving the treatment in two steps or one acute GnRHa injection. All of the fish that received GnRHa in emulsified form or in two steps injection ovulated in 10 and 11 days after injection respectively. In contrast, only 75% of the control fish and 60% of the fish with an acute injection ovulated up to 36 days after injection

    Gated Mode Superconducting Nanowire Single Photon Detectors

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    Single Photon Detectors (SPD) are fundamental to quantum optics and quantum information. Superconducting Nanowire SPDs (SNSPD) [1] provide high performance in terms of quantum efficiency (QE), dark count rate (DCR) and timing jitter [2], but have limited maximum count rate (MCR) when operated as a free-running mode (FM) detector [3, 4]. However, high count rates are needed for many applications like quantum computing [5] and communication [6], and laser ranging [7]. Here we report the first operation of SNSPDs in a gated mode (GM) that exploits a single photon triggered latching phenomenon to detect photons. We demonstrate operation of a large active area single element GM-SNSPD at 625MHz, one order of magnitude faster than its FM counterpart. Contrary to FM-SNSPDs, the MCR in GM can be pushed to GHz range without a compromise on the active area or QE, while reducing the DCR

    Effects of letrozole, non-steroidal aromatase inhibitor, on serum sex steroid levels, oocyte diameter and gonadosomatic index (GSI) in rainbow trout (Oncorhynchus mykiss)

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    The objective of this study was to contribute to investigate the efficacy of letrozole, a potent non-steroidal aromatase inhibitor, on serum sex steroid levels and oocyte growth in rainbow trout females. Serum steroid levels were measured using an indirect enzyme-linked immunosorbent assay (ELISA) before and 22 days after an initial injection with 1, 2.5 mg kg^-1 and subsequent weekly injection with 2.5 mg kg^-1 letrozole. After the last blood collection, gonad tissues were removed and oocyte diameter and GSI were determined. In all groups treated with letrozole, serum 17β-esteradiol levels (E2) decreased significantly and inversely serum 17α-20ß dihydroxy-4 pregnen-3-one (17α-20ß-P), testosterone (T) levels increased significantly from 6 to 96 h after injection (p<0.05). The lowest E2 levels, oocyte diameter and GSI were measured in the group treated weekly with 2.5 mg kg^-1 letrozole (p<0.05). This study demonstrates that letrozole has the potential to interfere in the synthesis of endogenous estrogens from androgens and delay gonadal development
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