202 research outputs found

    High-sensitive pyroelectric detectors with internal thermal amplification

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    AbstractA novel procedure for increasing the sensitivity of pyroelectric detectors and its mathematical and physical analysis are presented. Due to a 3-dimensional pattern that is etched into the sensitive element lateral heat flux spreading is used to improve the responsivity. Here, the effect is used, that very thin regions between thicker regions show a faster heating due to incident radiation and, hence, lead to an additional heat flow from this intermediate regions to the sensitive element. The analysis allows the description of the thermal and electrical behavior of the sensitive element depending on the dimensions of the pattern and the modulation frequency

    Monte Carlo Production Management at CMS

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    The analysis of the LHC data at the Compact Muon Solenoid (CMS) experiment requires the production of a large number of simulated events. During the RunI of LHC (20102012), CMS has produced over 12 Billion simulated events, organized in approximately sixty different campaigns each emulating specific detector conditions and LHC running conditions (pile up). In order to aggregate the information needed for the configuration and prioritization of the events production, assure the book-keeping of all the processing requests placed by the physics analysis groups, and to interface with the CMS production infrastructure, the web- based service Monte Carlo Management (McM) has been developed and put in production in 2013. McM is based on recent server infrastructure technology (CherryPy + AngularJS) and relies on a CouchDB database back-end. This contribution covers the one and half year of operational experience managing samples of simulated events for CMS, the evolution of its functionalities and the extension of its capability to monitor the status and advancement of the events production

    Terahertz Pulse Emission from Semiconductor Heterostructures Caused by Ballistic Photocurrents

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    Terahertz radiation pulses emitted after exciting semiconductor heterostructures by femtosecond optical pulses were used to determine the electron energy band offsets between different constituent materials. It has been shown that when the photon energy is sufficient enough to excite electrons in the narrower bandgap layer with an energy greater than the conduction band offset, the terahertz pulse changes its polarity. Theoretical analysis performed both analytically and by numerical Monte Carlo simulation has shown that the polarity inversion is caused by the electrons that are excited in the narrow bandgap layer with energies sufficient to surmount the band offset with the wide bandgap substrate. This effect is used to evaluate the energy band offsets in GaInAs/InP and GaInAsBi/InP heterostructures

    Vitamin E therapy in IgA nephropathy: a double-blind, placebo-controlled study

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    IgA nephropathy is the world's most common primary glomerulonephropathy. Recent evidence in a rat model implicated excessive production of oxygen-free radicals in the pathogenesis and suggested that vitamin E-treatment ameliorated progression. We studied this antioxidant therapy on the glomerular filtration rate (GFR), proteinuria and hematuria in biopsy-proven IgA nephropathy in children. The duration of treatment or placebo was 2 years, with vitamin E treatment consisting of 400 IU/day in children weighing 30 kg. We measured GFR at entry, midpoint and exit. At baseline and at 4-month intervals after randomization, urinary protein/creatinine ratios and urinalysis were examined. The mixed model procedure with log transformation was used in data analysis to test treatment difference as well as the potential time effect. Fifty-five patients were randomized and 38 completed at least 1 year of follow-up. At entry, the clinical characteristics were not different between the treatment and placebo groups. There was a trend toward better preservation of GFR in vitamin E-treated versus placebo patients, 127±50 vs. 112±31 ml/min/1.73 m 2 , respectively ( P =0.09). The urinary protein/creatinine ratio was significantly lower in the vitamin E-treated group vs. placebo; 0.24±0.38 vs. 0.61±1.37 ( P <0.013). However, there was no difference in the prevalence of hematuria between the groups. Vitamin E treatment in our study patients was associated with significantly lower proteinuria, but no effect on hematuria. While there was a trend toward stabilization of GFR in the vitamin E-treated patients, long-term treatment and follow-up are needed to determine whether antioxidant therapy is associated with preservation of renal function in IgA nephropathy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47819/1/467_2003_Article_1205.pd

    Baltic labour in the crucible of capitalist exploitation: reassessing 'post-communist' transformation

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    Thirty years after the fall of the Berlin Wall, this article re-assesses ‘post-communist’ transformation in the Baltic countries from the perspective of labour. The argument is based on a historical materialist approach focusing on the social relations of production as a starting point. It is contended that the uneven and combined unfolding of ‘post-communist’ transformation has subjected Baltic labour to doubly constituted exploitation processes. First, workers in Estonia, Latvia and Lithuania have suffered from extreme neoliberal restructuring of economic and employment relations at home. Second, migrant workers from Central and Eastern Europe in general, trying to escape exploitation at home, have faced another set of exploitative dynamics in host countries in Western Europe such as the UK. Nevertheless, workers have continued to challenge exploitation in Central and Eastern Europe and also in Western Europe, and have been active in extending networks of transnational solidarity across the continent

    The challenges of renewed independence: The Baltic states since 1991

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    This article offers a comparative assessment of how successfully Estonia, Latvia, and Lithuania have coped with the challenges of renewed independence since 1991, focusing on various aspects of political, economic, and social development. In the post-communist context the Baltic states have clearly outpaced other former Soviet republics and also performed reasonably well in comparison to the countries of Eastern Europe. The convergence of the Baltic experience, which began already in the early 20th century, has continued in the recent past as well, as the three states have adopted a number of similar approaches in domestic politics, the search for security, and economic policy. They also face a number of similar unsolved problems, including considerable political alienation, tensions in relations with Russia, socioeconomic disparity, and demographic challenges. The most important difference in the issues confronting the Baltic states today continues to be the large non-Baltic, mainly Russian presence in Estonia and Latvia, a result of Soviet-era policies. How to effect the meaningful integration of a multiethnic society remains a continuing challenge in these two countries. In contrast, population shifts under Soviet rule never became massive in Lithuania, and ethnic relations are a minor issue there today
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