45 research outputs found

    Feasibility of a Small, Rapid Optical-to-IR Response, Next Generation Gamma Ray Burst Mission

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    We present motivations for and study feasibility of a small, rapid optical to IR response gamma ray burst (GRB) space observatory. By analyzing existing GRB data, we give realistic detection rates for X-ray and optical/IR instruments of modest size under actual flight conditions. Given new capabilities of fast optical/IR response (about 1 s to target) and simultaneous multi-band imaging, such an observatory can have a reasonable event rate, likely leading to new science. Requiring a Swift-like orbit, duty cycle, and observing constraints, a Swift-BAT scaled down to 190 square cm of detector area would still detect and locate about 27 GRB per yr. for a trigger threshold of 6.5 sigma. About 23 percent of X-ray located GRB would be detected optically for a 10 cm diameter instrument (about 6 per yr. for the 6.5 sigma X-ray trigger).Comment: Elaborated text version of a poster presented at 2012 Malaga/Marbella symposiu

    The current status of orbital experiments for UHECR studies

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    Two types of orbital detectors of extreme energy cosmic rays are being developed nowadays: (i) TUS and KLYPVE with reflecting optical systems (mirrors) and (ii) JEM-EUSO with high-transmittance Fresnel lenses. They will cover much larger areas than existing ground-based arrays and almost uniformly monitor the celestial sphere. The TUS detector is the pioneering mission developed in SINP MSU in cooperation with several Russian and foreign institutions. It has relatively small field of view (+/-4.5 deg), which corresponds to a ground area of 6.4x10^3 sq.km. The telescope consists of a Fresnel-type mirror-concentrator (~2 sq.m) and a photo receiver (a matrix of 16x16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite, and is currently at the final stage of preflight tests. Recently, SINP MSU began the KLYPVE project to be installed on board of the Russian segment of the ISS. The optical system of this detector contains a larger primary mirror (10 sq.m), which allows decreasing the energy threshold. The total effective field of view will be at least +/-14 degrees to exceed the annual exposure of the existing ground-based experiments. Several configurations of the detector are being currently considered. Finally, JEM-EUSO is a wide field of view (+/-30 deg) detector. The optics is composed of two curved double-sided Fresnel lenses with 2.65 m external diameter, a precision diffractive middle lens and a pupil. The ultraviolet photons are focused onto the focal surface, which consists of nearly 5000 multi-anode photomultipliers. It is developed by a large international collaboration. All three orbital detectors have multi-purpose character due to continuous monitoring of various atmospheric phenomena. The present status of development of the TUS and KLYPVE missions is reported, and a brief comparison of the projects with JEM-EUSO is given.Comment: 18 pages; based on the rapporteur talk given by M.I. Panasyuk at ECRS-2014; v2: a few minor language issues fixed thanks to the editor; to be published in the proceeding

    Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

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    JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 ⋅ 1019 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics

    Science of atmospheric phenomena with JEM-EUSO

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    Dynamics of biochemical and immunological blood markers in patients with pseudoarthrosis of the femoral neck after total hip arthroplasty

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    The importance of biomarkers to predict recovery following total hip arthroplasty (THA) is still unclear to clinicians. To assess the preoperative biomarkers of patients with pseudoarthrosis of the femoral neck and their dynamics in the early postoperative period after THA, 50 patients aged 33 to 82 years old, 18 males and 32 females diagnosed with pseudoarthrosis of the femoral neck after failed internal fixation and failed conservative management were studied. The control group consisted of 30 healthy people aged 27 to 50 years, 13 males, 17 females. Patients’ blood was examined for biochemical markers upon admission, and then on the 7th and 14th days after surgery. Their blood serum content of total protein, albumin, glycoproteins, sialic acids, chondroitin sulfates, haptoglobin, glucose, cholesterol, triglycerides, ALT, AST, alkaline phosphatase, GGT, acid phosphatase, thymol index; interleukins (IL-1, IL-4 and IL-6.) and C-reactive protein was measured. The content of glycoproteins in the blood exceeded the norm by 2.3 times, chondroitin sulfate by 4.7 times, sialic acids by 1.5 times, haptoglobin by 55.8%, fibrinogen by 19.1%, globulin by 19,6%, alkaline phosphatase activity by 72.3%, IL-1 by 94.7 and IL-6 by 3 times, C-reactive protein by 2.6 times. After THA there was a gradual decrease in blood biochemical and immunological markers. The most informative laboratory markers were glycoproteins, chondroitin sulfates, sialic acids, haptoglobin, activity of alkaline phosphatase, IL-1, IL-6 and IL-4, and C-reactive protein. Subsequent research is required to validate these dynamics

    A Case of Agglutination and Hemolysis of Erythrocytes Caused by the Patient’s Own Plasma

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    The aim of the work was to study the agglutination and hemolysis of erythrocytes under diff erent conditions in vitro in a patient with unknown cause of anemia and concomitant secondary instability of endoprosthesis

    Performances of JEM–EUSO : energy and X_{max} reconstruction

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    The Extreme Universe Space Observatory (EUSO) on–board the Japanese Experimental Module (JEM) of the International Space Station aims at the detection of ultra high energy cosmic rays from space. The mission consists of a UV telescope which will detect the fluorescence light emitted by cosmic ray showers in the atmosphere. The mission, currently developed by a large international collaboration, is designed to be launched within this decade. In this article, we present the reconstruction of the energy of the observed events and we also address the X_{max} reconstruction. After discussing the algorithms developed for the energy and X_{max} reconstruction, we present several estimates of the energy resolution, as a function of the incident angle, and energy of the event. Similarly, estimates of the X_{max} resolution for various conditions are presented
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