Technological features of manufacturing an arched gears

Розглянуто технологічні особливості виготовлення та умови обробки загартованих аркових циліндричних зубчастих передач і арочних конічних передач з зачепленням М. Л. Новікова. Розроблена методика вибору конструкторсько-технологічних вимог аркових передач і система “РНС-1” геометричного розрахунку циліндричних, конічних і рейкових передач з арковими зубцями, а також уніфікація і скорочення номенклатури засобів виробництва. Проведені стендові випробування арочних зубчастих передач дозволили створити універсальний ріжучий інструмент з круглими незатылованными різцями.Purpose. Technological peculiarities of production and conditions of hardened cylindrical arched gears and arched bevel gears with meshing M. L. Novikova. Design/methodology/approach. Developed methodology for selection of design and technological requirements of the arched guide and the system "IR-1" geometric calculation of cylindrical, bevel and pinion gear with arched teeth, as well as unification and reduction of the range of the means of production. Bench tests of the arched gear has allowed us to create a versatile cutting tool with a round niesatynowany cutters. Conical spur, helical and herringbone gear, along with the advantages are inherent operational and technological disadvantages and in some cases do not satisfy the increasing requirements of modern gears to ensure smoothness, durability, reliability. The purpose of the design and process conditions for manufacturing an arched gears. Study of the technological features of manufacturing arched teeth at the present time is a real reserve for further enhancing the efficiency of gears and means for their production. Findings. Arched teeth allow to increase the load capacity of 1.25-1.5 times and durability in 2 - 3 times a cylindrical and a rack and pinion transmission, to reduce vibration, noise characteristics, intensity and cost. Originality/value. Arched teeth allow you to create a single technological system tools for the production of cylindrical, bevel and pinion gears provide smooth transmission of motion and can find application in high-speed high-load transmission.Рассмотрены технологические особенности изготовления и условия обработки закаленных цилиндрических арочных зубчатых передач и арочных конических передач с зацеплением М.Л. Новикова. Разработана методика по выбору конструкторско-технологических требований арочных передач и система “РНС-1” геометрического расчета цилиндрических, конических и реечных передач с арочными зубьями, а также унификация и сокращение номенклатуры средств производства. Проведенные стендовые испытания арочных зубчатых передач позволили создать универсальный режущий инструмент с круглыми незатылованными резцами

Graphene Synthesis Using a CVD Reactor and a Discontinuous Feed of Gas Precursor at Atmospheric Pressure

The present work shows a new method in order to cost-effectively achieve the synthesis of graphene by Chemical Vapor Deposition (CVD). Unlike most usual processes, where precursors such as argon, H2, CH4, and high purity copper foil are used, the proposed method has replaced the previous ones by N2, N2 (90%) : H2 (10%), C2H2, and electrolytic copper (technical grade) since the use of industrialized precursors helps reduce production costs. On the other hand, the process was modified from a continuous flow system with vacuum to a discontinuous one at atmospheric pressure, eliminating the use of vacuum pump. In addition, this modification optimized the consumption of gases, which reduced the waste and the emission of pollutant gases into the atmosphere. Graphene films were grown under different gas flowrates and temperatures. Then, the obtained material was characterized by TEM, Raman spectroscopy, and AFM, confirming the presence of few graphene layers. In brief, the growth time was reduced to six minutes with acetylene as a carbon precursor at 1000°C and at atmospheric pressure, with a flow rate of 30 sccm. Finally, the reported conditions can be used for the synthesis of good quality graphene films in industrial applications

Properties of Neutral Charmed Mesons in Proton--Nucleus Interactions at 70 GeV

The results of treatment of data obtained in the SERP-E-184experiment "Investigation of mechanisms of the production of charmed particles in proton-nucleus interactions at 70 GeV and their decays" by irradiating the active target of the SVD-2 facility consisting of carbon, silicon, and lead plates, are presented. After separating a signal from the two-particle decay of neutral charmed mesons and estimating the cross section for charm production at a threshold energy {\sigma}(c\v{c})=7.1 \pm 2.4(stat.) \pm 1.4(syst.) \mub/nucleon, some properties of D mesons are investigated. These include the dependence of the cross section on the target mass number (its A dependence); the behavior of the differential cross sections d{\sigma}/dpt2 and d{\sigma}/dxF; and the dependence of the parameter {\alpha} on the kinematical variables xF, pt2, and plab. The experimental results in question are compared with predictions obtained on the basis of the FRITIOF7.02 code.Comment: 9 pages, 9 figures,3 table

Observation of narrow baryon resonance decaying into pKs0pK^0_s in pA-interactions at 70GeV/c70 GeV/c with SVD-2 setup

SVD-2 experiment data have been analyzed to search for an exotic baryon state, the $\Theta^+$-baryon, in a $pK^0_s$ decay mode at $70 GeV/c$ on IHEP accelerator. The reaction $pA \to pK^0_s+X$ with a limited multiplicity was used in the analysis. The $pK^0_s$ invariant mass spectrum shows a resonant structure with $M=1526\pm3(stat.)\pm 3(syst.) MeV/c^2$ and $\Gamma < 24 MeV/c^2$. The statistical significance of this peak was estimated to be of $5.6 \sigma$. The mass and width of the resonance is compatible with the recently reported $\Theta^+$- baryon with positive strangeness which was predicted as an exotic pentaquark ($uudd\bar{s}$) baryon state. The total cross section for $\Theta^+$ production in pN-interactions for $X_F\ge 0$ was estimated to be $(30\div120) \mu b$ and no essential deviation from A-dependence for inelastic events $(\sim A^{0.7})$ was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos correcte

Role of gallium diffusion in the formation of a magnetically dead layer at the Y3Fe5O12/Gd3Ga5O12 epitaxial interface

We have clarified the origin of a magnetically dead interface layer formed in yttrium iron garnet (YIG) films grown at above 700 degrees C onto a gadolinium gallium garnet (GGG) substrate by means of laser molecular beam epitaxy. The diffusion-assisted formation of a Ga-rich region at the YIG/GGG interface is demonstrated by means of composition depth profiling performed by x-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and x-ray and neutron reflectometry. Our finding is in sharp contrast to the earlier expressed assumption that Gd acts as a migrant element in the YIG/GGG system. We further correlate the presence of a Ga-rich transition layer with considerable quenching of ferromagnetic resonance and spin wave propagation in thin YIG films. Finally, we clarify the origin of the enigmatic low-density overlayer that is often observed in neutron and x-ray reflectometry studies of the YIG/GGG epitaxial system