1,377 research outputs found

    Jet Energy Density in Hadron-Hadron Collisions at High Energies

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    The average particle multiplicity density dN/deta is the dynamical quantity which reflects some regularities of particle production in low-pT range. The quantity is an important ingredient of z-scaling. Experimental results on charged particle density are available for pp, pA and AA collisions while experimental properties of the jet density are still an open question. The goal of this work is to find the variable which will reflect the main features of the jet production in low transverse energy range and play the role of the scale factor for the scaling function psi(z) and variable z in data z-presentation. The appropriate candidate is the variable we called "scaled jet energy density". Scaled jet energy density is the probability to have a jet with defined ET in defined xT and pseudorapidity regions. The PYTHIA6.2 Monte Carlo generator is used for calculation of scaled jet energy density in proton-proton collisions over a high energy range (sqrt s = 200-14000 GeV) and at eta = 0. The properties of the new variable are discussed and sensitivity to "physical scenarios" applied in the standard Monte Carlo generator is noted. The results of scaled jet energy density at LHC energies are presented and compared with predictions based on z-scaling.Comment: 11 pages, LaTeX, 8 figures, Presented at the XVII International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics & Quantum Chromodynamics", Dubna, Russia, September 27 - October 2, 200

    The influence of KrF excimer laser irradiation on the surface of collagen and collagen/PVP films

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    The surface properties of collagen and collagen/poly(vinyl pyrrolidone) (PVP) films after KrF excimer laser irradiation (Ξ»=248nm) were investigated by means of the technique of scanning electron microscopy (SEM) and optical microscopy (OM). The laser irradiation of the used specimens caused an expansion of materials above their surface with pronounced sings of its melting. The height of the ablated volume in a case of collagen film at a fluence of 1.1J/cm2 was approximately 5ΞΌm. A white damage appears on the treated surfaces at a threshold of 0.5J/cm2 with a single pulse and becomes more visible for a higher fluence. It is also noteworthy that along with increasing fluences (beginning from the fluence of 1.7J/cm2), the characteristic filaments at the spot edges are observed. The local heat and pressure generated by the laser radiation were able to induce bubble formation on the surface. Further bubble colliding and bursting produce a three-dimensional polymer β€œmicrofoam” structure with interconnected pores. These results can be of interest for some new applications

    On saturation of charged hadron production in pp collisions at LHC

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    First results on charged hadron transverse momentum spectra in pp collisions obtained by the CMS Collaboration at LHC were analyzed in z-scaling approach. The first LHC data confirm z-scaling. The saturation regime of the scaling function psi(z) observed in pp and antp-pp interactions at lower energy sqrt s = 19-1960 GeV is verified. The saturation of psi(z) for charged hadrons is found down to z=0.05 at the highest energy sqrt s = 2360 GeV reached till now at colliders. A microscopic scenario of hadron production is discussed in connection with search for new signatures of phase transitions in hadron matter. Constituent energy loss and its dependencies on the transverse momentum of charged hadrons and collision energy are estimated. The beam energy scan at LHC in the saturation region is suggested.Comment: LaTeX, 6 pages, 6 figure

    Dairy cattle breeding effectiveness analysis under the conditions of import substitution

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    The relevance of the research problem is inspired by the strategic importance of dairy farming to the national economy, which is especially evident in the context of the EU economic sanctions against the Russian Federation and carrying out the import substitution policy. First and foremost, this policy applies to food commodities, including milk. The goal of the article is to study statistical productivity analysis of dairy cattle breeding as one of the major indicators to show its effectiveness (Privolzhsky Federal district in Russia is taken as the example). The main methods, used to study this problem are the index method, time series analysis, and correlation and regression analysis. As the study result there were identified the factors affecting the dairy cattle productivity, the prognosis and the conclusion about the positive aspects in solving problems of import substitution in the field of milk production. The article can be useful to regional governments in the development and adjustment programs for socio-economic development of subjects dealing with agriculture in the Volga Federal district of Russia. Β© 2016 Tokarev et al

    Influence of Silicon on Temperature Dependence of Thermal Conductivity of Al–Si–Fe Alloys

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    Temperature dependence analysis of thermal conductivity was carried out for series of aluminum alloys with 1% Fe (mass%) and different content of silicon starting from 0% to 6% (mass%). It is shown that the best alloy for heat exchange applications is alloy with 4% of silicon (mass%). Temperature dependence of thermal conductivity shows the strong decreasing character for silicon-alloyed samples in comparison to pure aluminum. Keywords: aluminum–silicon alloys, thermal conductivity, heat exchange, iron, cast alloys, structure, temperatur

    On QCD Q2Q^2-evolution of Deuteron Structure Function F2D(xD,Q2)F_2^D(x_D,Q^2) for xD>1x_D>1

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    The deep-inelastic deuteron structure function (SF) F2D(xD,Q2)F_2^D(x_D,Q^2) in the covariant approach in light-cone variables is considered. The xDx_D and Q2Q^2-dependences of SF are calculated. The QCD analysis of generated data both for non-cumulative xD1x_D1 ranges was performed. It was shown that Q2Q^2-evolution of SF is valid for ranges 0.275<xD<0.850.275<x_D<0.85 and 1.1<xD<1.41.1<x_D<1.4 for the same value of QCD scale parameter Ξ›{\Lambda}. It was found the xDx_D-dependence of SF for the ranges is essentially different.Comment: LaTeX, 10 pages, 2 Postscript figure

    ΠšΠ°Ρ‡Π΅ΡΡ‚Π²Π΅Π½Π½Π°Ρ ΠΈ количСствСнная ΠΎΡ†Π΅Π½ΠΊΠ° Π»ΠΈΠΊΠ²ΠΎΡ€ΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ

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    Disorders of cerebrospinal fluid (CSF) secretion, dynamics and absorption are common in different illnesses and injuries of the central nervous system (CNS). Nowadays magnetic-resonance tomography (MRI) is the leading research method of CSF dynamics. There are some MRI techniques for both qualitative and quantitative evaluation of CSF dynamic. The assessment of CSF movement is needed to define treatment strategy for patients with different types of hydrocephalus. In this review we have summarized the information about physic basement, area of application of modern MRI techniques. The main attention was paid to modern views on hydrocephalus pathogenesis, pathological CSF flow dynamics in CNS disorders and traumatic brain injury.ΠΠ°Ρ€ΡƒΡˆΠ΅Π½ΠΈΡ ΠΏΡ€ΠΎΠ΄ΡƒΠΊΡ†ΠΈΠΈ, Ρ‚ΠΎΠΊΠ° ΠΈ Ρ€Π΅Π·ΠΎΡ€Π±Ρ†ΠΈΠΈ спинномозговой Тидкости (Π‘ΠœΠ–) Π²ΡΡ‚Ρ€Π΅Ρ‡Π°ΡŽΡ‚ΡΡ ΠΏΡ€ΠΈ ΠΌΠ½ΠΎΠ³ΠΈΡ… заболСваниях ΠΈ поврСТдСниях Π½Π΅Ρ€Π²Π½ΠΎΠΉ систСмы. Π’ настоящСС врСмя ΠΌΠ°Π³Π½ΠΈΡ‚Π½ΠΎ-рСзонансная томография (МРВ) являСтся Π²Π΅Π΄ΡƒΡ‰ΠΈΠΌ ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ исслСдования Π»ΠΈΠΊΠΎΠ²ΠΎΡ€ΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ. На сСгодняшний дСнь извСстно нСсколько ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΈΠΊ исслСдования, ΠΊΠΎΡ‚ΠΎΡ€Ρ‹Π΅ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡŽΡ‚ ΠΎΡ†Π΅Π½ΠΈΡ‚ΡŒ качСствСнныС ΠΈ количСствСнныС ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€Ρ‹ двиТСния спинномозговой Тидкости. ΠžΡ†Π΅Π½ΠΊΠ° Π»ΠΈΠΊΠ²ΠΎΡ€ΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ Π½Π΅ΠΎΠ±Ρ…ΠΎΠ΄ΠΈΠΌΠ° для опрСдСлСния ΠΏΡ€Π°Π²ΠΈΠ»ΡŒΠ½ΠΎΠΉ Ρ‚Π°ΠΊΡ‚ΠΈΠΊΠΈ лСчСния ΠΏΠ°Ρ†ΠΈΠ΅Π½Ρ‚ΠΎΠ² с Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹ΠΌΠΈ Π²ΠΈΠ΄Π°ΠΌΠΈ Π³ΠΈΠ΄Ρ€ΠΎΡ†Π΅Ρ„Π°Π»ΠΈΠΈ. Π’ ΠΎΠ±Π·ΠΎΡ€Π΅ Π»ΠΈΡ‚Π΅Ρ€Π°Ρ‚ΡƒΡ€Ρ‹ ΠΏΡ€ΠΈΠ²Π΅Π΄Π΅Π½Ρ‹ физичСскиС основы, области примСнСния соврСмСнных МРВ-ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠ² изучСния Π»ΠΈΠΊΠ²ΠΎΡ€ΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ. ОсобоС Π²Π½ΠΈΠΌΠ°Π½ΠΈΠ΅ ΡƒΠ΄Π΅Π»Π΅Π½ΠΎ соврСмСнным взглядам Π½Π° ΠΏΠ°Ρ‚ΠΎΠ³Π΅Π½Π΅Π· Π³ΠΈΠ΄Ρ€ΠΎΡ†Π΅Ρ„Π°Π»ΠΈΠΈ, особСнностям Ρ‚ΠΎΠΊΠ° Π»ΠΈΠΊΠ²ΠΎΡ€Π° ΠΏΡ€ΠΈ Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… заболСваниях Ρ†Π΅Π½Ρ‚Ρ€Π°Π»ΡŒΠ½ΠΎΠΉ Π½Π΅Ρ€Π²Π½ΠΎΠΉ систСмы ΠΈ Ρ‡Π΅Ρ€Π΅ΠΏΠ½ΠΎ-ΠΌΠΎΠ·Π³ΠΎΠ²ΠΎΠΉ Ρ‚Ρ€Π°Π²ΠΌΠ΅

    Tungstate Based Ceramics Obtained By Spark Plasma Sintering Method – Possible Material for Consolidation of Radioactive Wastes’ Components

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    The Spark Plasma Sintering method was used to produce high-density ceramics from tungstates SrWO4 and NaNd(WO4)2 with scheelite structure. These compounds are proposed as possible matrices for the consolidation of radwaste components. Powder samples were obtained by coprecipitation method and studied by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). After sintering, the samples retained their phase identity (scheelite structure). The total duration of sintering was ∼ 13-15 min, the relative density was reached ∼ 92, 99%. Keywords: Tungstates, RW, Spark Plasma Sintering, high density, microstructur

    Analysis of fractal events with background

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    Properties of self-similarity and fractality in the processes of interactions of hadrons and nuclei at high energies are discussed. Different methods of fractal analysis (the box counting BC, system of the equations of p-adic coverage S ePaC methods) are described. Fractal analysis of mixed events was carried out by BC and S ePaC methods. The procedure of separation of fractals and background, estimation of the number of fractals in the original data set and contamination of the extracted data was proposed. The dependence of event contamination on multiplicity and background is studied. Reconstruction of the spectrum of fractal dimensions is found to depend on the method and background
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