358 research outputs found
Effect of inaction on function of fast and slow muscle spindles
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
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
ΠΠ·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Ρ ΠΏΠ°Π»ΡΡΠ΅Π²ΠΎΠ³ΠΎ ΠΈΠ½Π΄Π΅ΠΊΡΠ° ΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΏΡΠ΅Π΄ΠΌΠ΅ΡΠ½ΠΎ-ΠΏΠΎΠ·Π½Π°Π²Π°ΡΠ΅Π»ΡΠ½ΡΡ ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΠ΅ΠΉ ΡΠΊΠΎΠ»ΡΠ½ΠΈΠΊΠΎΠ²
Π Π½Π°ΡΡΠΎΡΡΠ΅Π΅ Π²ΡΠ΅ΠΌΡ ΡΠ΄Π΅Π»ΡΡΡ ΡΠ΅ΡΡΠ΅Π·Π½ΠΎΠ΅ Π²Π½ΠΈΠΌΠ°Π½ΠΈΠ΅ Π°Π½ΡΡΠΎΠΏΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΌΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ. ΠΠ°ΠΌΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΠ°Π»ΡΡΠ΅Π²ΠΎΠ³ΠΎ ΠΈΠ½Π΄Π΅ΠΊΡΠ° Ρ ΡΠΊΠΎΠ»ΡΠ½ΠΈΠΊΠΎΠ² ΡΡΠ°ΡΡΠΈΡ
ΠΊΠ»Π°ΡΡΠΎΠ². Π ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΈ ΠΏΡΠΈΠ½ΠΈΠΌΠ°Π»ΠΈ ΡΡΠ°ΡΡΠΈΠ΅ 24 ΡΠΊΠΎΠ»ΡΠ½ΠΈΠΊΠ°, ΠΈΠ· Π½ΠΈΡ
ΠΌΠ°Π»ΡΡΠΈΠΊΠΎΠ² - 10 ΠΈ Π΄Π΅Π²ΠΎΡΠ΅ΠΊ - 14; ΡΡΠ΅Π΄Π½ΠΈΠΉ Π²ΠΎΠ·ΡΠ°ΡΡ - 14,5 Π»Π΅Ρ. ΠΠΊΠ°Π·Π°Π»ΠΎΡΡ, ΡΡΠΎ Ρ Π±ΠΎΠ»ΡΡΠΈΠ½ΡΡΠ²Π° ΠΌΠ°Π»ΡΡΠΈΠΊΠΎΠ² ΠΏΠ°Π»ΡΡΠ΅Π²ΠΎΠΉ ΠΈΠ½Π΄Π΅ΠΊΡ Π½ΠΈΠΆΠ΅ Π΅Π΄ΠΈΠ½ΠΈΡΡ. Π¨ΠΊΠΎΠ»ΡΠ½ΠΈΡΡ Ρ ΠΏΠ°Π»ΡΡΠ΅Π²ΡΠΌ ΠΈΠ½Π΄Π΅ΠΊΡΠΎΠΌ Π΅Π΄ΠΈΠ½ΠΈΡΠ° ΠΈ Π²ΡΡΠ΅ Π΅Π΄ΠΈΠ½ΠΈΡΡ ΡΡΠ°ΡΡΡ Π»ΡΡΡΠ΅, Π·Π°Π½ΠΈΠΌΠ°ΡΡΡΡ Π°ΠΊΡΠΈΠ²Π½ΠΎ ΡΠΏΠΎΡΡΠΎΠΌ, ΠΈΠ½ΡΠ΅ΡΠ΅ΡΡΡΡΡΡ ΡΠ°Π½ΡΠ°ΠΌΠΈ ΠΈ ΠΌΡΠ·ΡΠΊΠΎΠΉ. ΠΠ΄Π½Π°ΠΊΠΎ, Π΄ΠΎΡΡΠΎΠ²Π΅ΡΠ½ΠΎΠΉ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΡΡΠΏΠ΅Ρ
ΠΎΠ² ΠΏΠΎ ΡΡΡΡΠΊΠΎΠΌΡ ΡΠ·ΡΠΊΡ ΠΎΡ ΠΏΠ°Π»ΡΡΠ΅Π²ΠΎΠ³ΠΎ ΠΈΠ½Π΄Π΅ΠΊΡΠ° Ρ ΡΠΊΠΎΠ»ΡΠ½ΠΈΠΊΠΎΠ² Π½Π΅ ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½ΠΎ. ΠΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎ, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅ Π΄Π°Π½Π½ΡΠ΅ ΡΠ²ΡΠ·Π°Π½Ρ Ρ ΠΌΠ°Π»Π΅Π½ΡΠΊΠΎΠΉ Π²ΡΠ±ΠΎΡΠΊΠΎΠΉ ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»
Heat accumulation effects in laser processing of diamond-like nanocomposite films with bursts of femtosecond pulses
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
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
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
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
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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