142 research outputs found

    Armored carrier MT-LB and support vehicles produced on its basis in Poland

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    The article presents the history of construction of the armored carrier MT-LB designed in 1960s in Kharkiv Tank Factory in the USSR. The serial production of the carrier in Poland and the involvement of Polish scientific and research centers in the preparation of its specialized versions is discussed. The individual versions of the carrier are characterized, streaming them according to: vehicles produced in Poland, prototype vehicles constructed in Polish scientific and research centers and vehicles obtained for the Polish Armed Forces under import. Furthermore, the article outlines the utilization of the MT-LB armored carrier and anti-aircraft missile launchers, engineering vehicles, armored recovery and command-staff vehicles built on its basis by the Polish Armed Forces’ units, drawing the attention to their role in process of technical modernization of the land forces

    TOFtracker: combination of time-of-flight and high-accuracy bidimensional tracking in a single gaseous detector

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    A 5-gap timing RPC equipped with patterned electrodes coupled to both charge-sensitive and timing circuits yields a time accuracy of 77 ps along with a position accuracy of 38 μm. These results were obtained by calculating the straight-line fit residuals to the positions provided by a 3-layer telescope made out of identical detectors, detecting almost perpendicular cosmic-ray muons. The device may be useful for particle identification by time-of-flight, where simultaneous measurements of trajectory and time are necessary

    Biotinylated Metathesis Catalysts: Synthesis and Performance in Ring Closing Metathesis

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    Nine biotinylated Grubbs-Hoveyda and Grubbs-type metathesis catalysts were synthesized and evaluated in ring closing metathesis reactions of N-tosyl diallylamine and 5-hydroxy-2-vinylphenyl acrylate. Their catalytic activity in organic- and aqueous solvents was compared with the second generation Grubbs-Hoveyda catalyst. The position of the biotin-moiety on the N-heterocyclic carbene was found to critically influence the catalytic activity of the corresponding ruthenium-based catalysts. Graphical Abstract

    Ruthenium Complex Bearing a Hydroxy Group Functionalised N-Heterocyclic Carbene Ligand – A Universal Platform for Synthesis of Tagged and Immobilised Catalysts for Olefin Metathesis

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    Six olefin metathesis catalysts, based on a common ruthenium precursor featuring a hydroxy-substituted N-heterocyclic carbene ligand, were successfully prepared and fully characterised. As proof-of-concept, two of them ([Ru]isonico and [Ru]dmab) were directly immobilised on a solid support. These non-covalently heterogenised catalysts are efficient in different metathesis reactions and sufficiently stable to be used for repeated runs under batch and continuous flow conditions. In nonpolar media such as n-hexane, the catalytic character of the metathesis reactions is truly heterogeneous, and the contamination of the products with ruthenium is very low. © 2021 The Authors. European Journal of Organic Chemistry published by Wiley-VCH Gmb

    Electromagnetic Calorimeter for HADES

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    We propose to build the Electromagnetic calorimeter for the HADES di-lepton spectrometer. It will enable to measure the data on neutral meson production from nucleus-nucleus collisions, which are essential for interpretation of dilepton data, but are unknown in the energy range of planned experiments (2-10 GeV per nucleon). The calorimeter will improve the electron-hadron separation, and will be used for detection of photons from strange resonances in elementary and HI reactions. Detailed description of the detector layout, the support structure, the electronic readout and its performance studied via Monte Carlo simulations and series of dedicated test experiments is presented. The device will cover the total area of about 8 m^2 at polar angles between 12 and 45 degrees with almost full azimuthal coverage. The photon and electron energy resolution achieved in test experiments amounts to 5-6%/sqrt(E[GeV]) which is sufficient for the eta meson reconstruction with S/B ratio of 0.4% in Ni+Ni collisions at 8 AGeV. A purity of the identified leptons after the hadron rejection, resulting from simulations based on the test measurements, is better than 80% at momenta above 500 MeV/c, where time-of-flight cannot be used.Comment: 40 pages, 38 figures version2 - the time schedule added, information about PMTs in Sec.III update

    Multichannel FPGA based MVT system for high precision time (20~ps~RMS) and charge measurement

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    In this article it is presented an FPGA based MMulti-VVoltage TThreshold (MVT) system which allows of sampling fast signals (121-2 ns rising and falling edge) in both voltage and time domain. It is possible to achieve a precision of time measurement of 2020 ps RMS and reconstruct charge of signals, using a simple approach, with deviation from real value smaller than 10%\%. Utilization of the differential inputs of an FPGA chip as comparators together with an implementation of a TDC inside an FPGA allowed us to achieve a compact multi-channel system characterized by low power consumption and low production costs. This paper describes realization and functioning of the system comprising 192-channel TDC board and a four mezzanine cards which split incoming signals and discriminate them. The boards have been used to validate a newly developed Time-of-Flight Positron Emission Tomography system based on plastic scintillators. The achieved full system time resolution of σ\sigma(TOF) 68\approx 68 ps is by factor of two better with respect to the current TOF-PET systems.Comment: Accepted for publication in JINST, 10 pages, 8 figure

    Evaluation of Single-Chip, Real-Time Tomographic Data Processing on FPGA - SoC Devices

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    A novel approach to tomographic data processing has been developed and evaluated using the Jagiellonian PET (J-PET) scanner as an example. We propose a system in which there is no need for powerful, local to the scanner processing facility, capable to reconstruct images on the fly. Instead we introduce a Field Programmable Gate Array (FPGA) System-on-Chip (SoC) platform connected directly to data streams coming from the scanner, which can perform event building, filtering, coincidence search and Region-Of-Response (ROR) reconstruction by the programmable logic and visualization by the integrated processors. The platform significantly reduces data volume converting raw data to a list-mode representation, while generating visualization on the fly.Comment: IEEE Transactions on Medical Imaging, 17 May 201
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