20 research outputs found

    High-Power Laser Systems of UV and Visible Spectral Ranges

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    Three high-power excimer laser systems with apertures of 25 and 40 cm of the output laser beam are described. The first and second laser systems consist of four and five excimer lasers, respectively. Third system consists of Ti:Sa front end and XeF(C-A) amplifier. The experimental results of the generation of the high-quality and high-power laser pulses are presented. Laser beams with pulse energy of up to 330 J (308 nm, 250 ns) and peak power 14 TW (450 nm, 50 fs) were obtained

    KrF laser with a power of 100 W

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    The development of effective discharge pulse-repetition KrF laser is informed. Research the possibility of forming in this laser long laser pulse with input pump energy for a few half periods of the discharge current are presented. In the repetitively pulsed regime (up to 100 Hz) laser provides laser pulses with energy of 1 J and duration of 60 ns at the base. The maximum total efficiency of the laser is 3%. The results of studies on the formation in this laser of narrowband radiation with a wide spectral band tuning are reported. The possibility of forming a radiation pulse with a linewidth 2 pm, energy 0.15 J and spectral tuning region 247.5-249.6 nm are demonstrated. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Aspects for efficient wide spectral band THz generation via CO2 laser down conversion

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    Detailed model study of THz generation by CO2 laser down-conversion in pure and solid solution crystals GaSe1-xSx is carried out for the first time. Both forward and backward collinear interactions of common (eo-e, oe-e, oe-o, oo-e, ee-o) and original (ee-e, oo-o) types are considered. Possibility of realization, phase matching angles and figure of merits are estimated for line mixing within 9 μm and 10 μm emission bands, as well between them. Dispersion properties of o- and e-wave refractive indices and absorption coefficients for GaSe, GaS and GaSe1-xSx crystals were preliminary measured by THz-TDS, approximated in the equation form and then used in the study. Estimated results are presented in the form of 3-D figures that are suitable for rapid analyses of DFG parameters. The most efficient type of interaction is eo-o type. Optimally doped (x = 0.09-0.13) GaSe1-xSx crystals are from 4 to 5 times more efficient at limit pump intensity than not doped GaSe crystals

    A method for identification of the methylation level of CpG islands from NGS data

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    In the course of sample preparation for Next Generation Sequencing (NGS), DNA is fragmented by various methods. Fragmentation shows a persistent bias with regard to the cleavage rates of various dinucleotides. With the exception of CpG dinucleotides the previously described biases were consistent with results of the DNA cleavage in solution. Here we computed cleavage rates of all dinucleotides including the methylated CpG and unmethylated CpG dinucleotides using data of the Whole Genome Sequencing datasets of the 1000 Genomes project. We found that the cleavage rate of CpG is significantly higher for the methylated CpG dinucleotides. Using this information, we developed a classifier for distinguishing cancer and healthy tissues based on their CpG islands statuses of the fragmentation. A simple Support Vector Machine classifier based on this algorithm shows an accuracy of 84%. The proposed method allows the detection of epigenetic markers purely based on mechanochemical DNA fragmentation, which can be detected by a simple analysis of the NGS sequencing data

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    Lidar Detection of Explosives Traces

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    The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF) is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT), hexogen (RDX), trotyl-hexogen (Comp B), octogen (HMX), and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented

    INCREASE OF AIR DEDUSTING EFFECTIVENESS IN FUNCTIONAL ZONES OF METAL- AND WOODWORKING PRODUCTIONS

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    A new cyclone apparatus enable to control the part specifications depending on the dust environment properties and characteristics is designed. This leads to the increase of the processing off-gas collection efficiency. The experimental study is resulted, and the geometrics of the diversiform cyclonic devices is related to the dedusting effectiveness. It is shown that the dedusting efficiency is higher in the inverted-cone cyclones (ICC) than in the cylinder devices. The ICC optimal design factors (the immersion depth of an exhaust branch pipe, and the cyclone working part/bunker volume ratio) raising the dust cleaning degree are found. The ICC with controlled parameters and with the gravity-discharge bin is offered. The developed ICC allows the considerable efficiency increase of the preliminary air cleaning from the metal- and woodworking production dust
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