358 research outputs found

    Effect of inaction on function of fast and slow muscle spindles

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    There is no data on the comparative effect of tenotomy on the function of the muscle spindles of fast and slow muscles. This study covers this question. The experiments were conducted on cats. The musuculus extensor digitorum longus (m. EDL) was selected as the fast muscle, and the musculus soleus (m. Sol.) as the slow. In a comparison of the spontaneous activity of primary and secondary endings of the fast and slow muscle spindles (i.e., the activity with complete relaxation of the muscles) normally no difference between them was successfully found. The authors recorded the integrative, and not the individual activity, and secondly, under conditions of such recording technique, those slight changes that are observed in the fast muscle receptors could remain unnoticed

    Application of the Fracture Mechanics and Reliability Methods to the Fatigue Problem

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    AbstractThe fatigue problem of high strength materials and complex mechanical systems subjected to cyclic loadings and corrosion environment is studied. It is assumed that the element of a system contains the initial cracks with the sizes expressed in the form of Weibull distribution. The kinetic equation of corrosion fatigue cracks growth, describing the cracks growth under Paris's law in the absence of the corrosion environment and purely corrosion growth of cracks in the absence of external stresses is developed. Taking into account that the reliability of the system as a whole depends on the reliability of individual elements and the type of their connection, the different types of connection, in particularly, in series, parallel and with reservation are considered. For each system the reliability function and the corresponding fatigue strength criterion are formulated

    Π’Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·ΡŒ ΠΏΠ°Π»ΡŒΡ†Π΅Π²ΠΎΠ³ΠΎ индСкса ΠΈ развития ΠΏΡ€Π΅Π΄ΠΌΠ΅Ρ‚Π½ΠΎ-ΠΏΠΎΠ·Π½Π°Π²Π°Ρ‚Π΅Π»ΡŒΠ½Ρ‹Ρ… способностСй школьников

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    Π’ настоящСС врСмя ΡƒΠ΄Π΅Π»ΡΡŽΡ‚ ΡΠ΅Ρ€ΡŒΠ΅Π·Π½ΠΎΠ΅ Π²Π½ΠΈΠΌΠ°Π½ΠΈΠ΅ антропологичСскому исслСдованию. Нами ΠΏΡ€ΠΎΠ²Π΅Π΄Π΅Π½ΠΎ исслСдованиС ΠΏΠ°Π»ΡŒΡ†Π΅Π²ΠΎΠ³ΠΎ индСкса Ρƒ школьников ΡΡ‚Π°Ρ€ΡˆΠΈΡ… классов. Π’ исслСдовании ΠΏΡ€ΠΈΠ½ΠΈΠΌΠ°Π»ΠΈ участиС 24 школьника, ΠΈΠ· Π½ΠΈΡ… ΠΌΠ°Π»ΡŒΡ‡ΠΈΠΊΠΎΠ² - 10 ΠΈ Π΄Π΅Π²ΠΎΡ‡Π΅ΠΊ - 14; срСдний возраст - 14,5 Π»Π΅Ρ‚. Оказалось, Ρ‡Ρ‚ΠΎ Ρƒ Π±ΠΎΠ»ΡŒΡˆΠΈΠ½ΡΡ‚Π²Π° ΠΌΠ°Π»ΡŒΡ‡ΠΈΠΊΠΎΠ² ΠΏΠ°Π»ΡŒΡ†Π΅Π²ΠΎΠΉ индСкс Π½ΠΈΠΆΠ΅ Π΅Π΄ΠΈΠ½ΠΈΡ†Ρ‹. Π¨ΠΊΠΎΠ»ΡŒΠ½ΠΈΡ†Ρ‹ с ΠΏΠ°Π»ΡŒΡ†Π΅Π²Ρ‹ΠΌ индСксом Π΅Π΄ΠΈΠ½ΠΈΡ†Π° ΠΈ Π²Ρ‹ΡˆΠ΅ Π΅Π΄ΠΈΠ½ΠΈΡ†Ρ‹ учатся Π»ΡƒΡ‡ΡˆΠ΅, Π·Π°Π½ΠΈΠΌΠ°ΡŽΡ‚ΡΡ Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎ спортом, ΠΈΠ½Ρ‚Π΅Ρ€Π΅ΡΡƒΡŽΡ‚ΡΡ Ρ‚Π°Π½Ρ†Π°ΠΌΠΈ ΠΈ ΠΌΡƒΠ·Ρ‹ΠΊΠΎΠΉ. Однако, достовСрной зависимости успСхов ΠΏΠΎ русскому языку ΠΎΡ‚ ΠΏΠ°Π»ΡŒΡ†Π΅Π²ΠΎΠ³ΠΎ индСкса Ρƒ школьников Π½Π΅ ΠΎΠ±Π½Π°Ρ€ΡƒΠΆΠ΅Π½ΠΎ. Π’ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎ, ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Π½Ρ‹Π΅ Π΄Π°Π½Π½Ρ‹Π΅ связаны с малСнькой Π²Ρ‹Π±ΠΎΡ€ΠΊΠΎΠΉ исслСдуСмого ΠΌΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π»

    Heat accumulation effects in laser processing of diamond-like nanocomposite films with bursts of femtosecond pulses

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    In this paper we have investigated the burst mode (BM) ablation and surface structuring of diamond-like nanocomposite (DLN) a-C:H:Si:O films with femtosecond laser pulses (wavelength Ξ»=515 nm, pulse duration Ο„=320 fs, pulse repetition rate f=100 kHz) under different scanning conditions (single spots, linear structures). The pulse separation in the bursts is 25 ns (intra-burst frequency f=40 MHz) and the pulse number is varied from 1 to 8. The ablation depth and specific ablation rates (ΞΌm3/ΞΌJ) are found to be higher for the burst mode compared to single pulse irradiation, increasing with the pulse number in the burst. The obtained experimental data of the higher ablation efficiency are shown to correlate with computer simulations of the BM ablation. In correlation with the ablation findings, Raman spectra of single spots and microgrooves have evidenced a growing graphitization of amorphous film structure with the pulse number in the bursts (at equal energy deposited into the films). Contact-mode atomic force microscopy (AFM) is applied to reveal an influence of the BM processing on the surface properties (nanoscale relief, friction) of laser-structured films. Based on the ablation and Raman data analysis, AFM examination of ablated/redeposited layers and computer simulations of the burst mode ablation, the heat accumulation is identified as the main factor responsible for the enhanced ablation efficiency during the BM processing of DLN films. In addition, results of high precision surface microstructuring of DLN films in the burst mode are presented

    Measurement of Dielectric Suppression of Bremsstrahlung

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    In 1953, Ter-Mikaelian predicted that the bremsstrahlung of low energy photons in a medium is suppressed because of interactions between the produced photon and the electrons in the medium. This suppression occurs because the emission takes place over on a long distance scale, allowing for destructive interference between different instantaneous photon emission amplitudes. We present here measurements of bremsstrahlung cross sections of 200 keV to 20 MeV photons produced by 8 and 25 GeV electrons in carbon and gold targets. Our data shows that dielectric suppression occurs at the predicted level, reducing the cross section up to 75 percent in our data.Comment: 11 pages, format is postscript file, gzip-ed, uuencode-e

    Description of radiation conditions and evaluation of the date of <sup>137</sup>Cs release to the atmosphere using the radionuclide transfer model coupled with the forecasts by the mesoscale hydrodynamic model

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    Β© 2016, Allerton Press, Inc.The estimates of 137Cs emissions from the accident happened in Elektrostal at the beginning of April 12, 2013 are presented. The transport of radionuclides and their dry and wet deposition on the surface are computed using the Lagrangian stochastic model of the NOSTRADAMUS software package worked out by Nuclear Safety Institute of Russian Academy of Sciences. Prognostic fields of wind (horizontal and vertical components) in the lower troposphere, precipitation, and vertical and horizontal turbulence diffusivity coefficients in the lower atmosphere (up to 4 km) were used as input data. Prognostic fields were obtained using the WRF-ARW numerical mesoscale model

    Usual and written law in the russian state of the early modern era: the problem of correlation

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    The article deals with the problems associated with the peculiarities of Russian state legal system development during the early modern era. The authors focused on the correlation of oral legal tradition, which forms the basis of customary law, and written, codified la

    Bremsstrahlung Suppression due to the LPM and Dielectric Effects in a Variety of Materials

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    The cross section for bremsstrahlung from highly relativistic particles is suppressed due to interference caused by multiple scattering in dense media, and due to photon interactions with the electrons in all materials. We present here a detailed study of bremsstrahlung production of 200 keV to 500 MeV photons from 8 and 25 GeV electrons traversing a variety of target materials. For most targets, we observe the expected suppressions to a good accuracy. We observe that finite thickness effects are important for thin targets.Comment: 52 pages, 13 figures (incorporated in the revtex LaTeX file
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