28 research outputs found

    Study of the energy spectrum of primary cosmic rays: EAS size fluctuations at a fixed primary energy

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    During the initial period of the Samarkand EAS array operations the showers were selected on the basis of charged-particle flux density, and during the subsequent periods the showers were selected on the basis of Cerenkov light flux density. This procedure made it possible to measure the shower energy, to estimate the EAS size fluctuations at a fixed primary energy, and to experimentally obtain the scaling factor K(Ne, Eo) from the EAS size spectrum to the primary energy spectrum. Six scintillators of area S = 2 sq m each were added to the array. The fluctuations of EAS sizes in the showers of fixed primary energies and the scaling factors K(Ne, Eo) were inferred from the data obtained. The showers with zenith angles 30 deg were selected. The EAS axis positions were inferred from the amplitude data of the scintillators. The primary energy Eo was determined by the method of least squares for the known EAS axis position using the data of the Cerenkov detector located at 80 to 150 m EAS axis. It is shown that the Cerenkov light flux fluctuations at 100 m from EAS axis, q sub 100, do not exceed 10% at a fixed EAS energy, so the parameter q sub 100 may be used to estimate the EAS-generating primary particle-energy

    On the determination of the depth of EAS development maximum using the lateral distribution of Cerenkov light at distances 150 m from EAS axis

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    The Samarkand extensive air showers (EAS) array was used to measure the mean and individual lateral distribution functions (LDF) of EAS Cerenkov light. The analysis of the individual parameters b showed that the mean depth of EAS maximum and the variance of the depth distribution of maxima of EAS with energies of approx. 2x10 to the 15th power eV can properly be described in terms of Kaidalov-Martirosyan quark-gluon string model (QGSM)

    STUDY OF THE MECHANICAL PROPERTIES OF FABRICS FROM COMPOSITE FIBERS AND EVALUATION OF TEST RESULTS ACCORDING TO THE LAWS OF STATISTICS AND PROBABILITY THEORY

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    This article presents the results of experimental studies of the physical and mechanical properties of a fabric made of threads with different fibrous composition, statistical processing and evaluation using probability theory. The main goal of the research is to identify the most rational fibrous composition of threads for the production of the required fabric of the dress assortment. In the course of the experiment, studies were carried out on the physical and mechanical properties of a fabric made of threads using cotton and mixed fibers with different fibers. As a result of the research, recommendations were developed on the rational composition of the new fabric of the dress assortment

    Study of the shower maximum depth by the method of detection of the EAS Cerenkov light pulse shape

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    The results of processing the data on the shape of the EAS Cerenkov light pulses recorded by the extensive air showers (EAS) array are presented. The pulse FWHM is used to find the mean depth of EAS maximum

    The change in the inclination angle of the non-eclipsing binary SS Lacertae: future eclipses

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    Eclipses in the 14.4-day period double-lined binary SS Lac were observed photographically and visually early in the 20th century, but stopped some 50 or 60 years ago. This has been explained by the presence of a distant third star in the system, which has now been detected spectroscopically with a period of 679 days. The plane of the orbit of the binary is changing relative to the line of sight in response to perturbations from this third object. A recent analysis by Milone et al. (M00) of all photometric material available for the system, including a re-measurement of original Harvard plates, has confirmed earlier reports of changes in the depth of the eclipses as a function of time, which are due to the third star. In this paper we discuss our detailed analysis of the eclipse amplitude measurements, and extract from them information on the change in the inclination angle of the binary over the last century. Our use of a much improved ephemeris for the system by Torres & Stefanik was found to be crucial, and prompted us to re-determine all the amplitudes from the historical data at our disposal, including the Harvard material used by M00. Systematically lower measurements on the branches of the minima were properly accounted for, and we made use of both a linear approximation to the time variation of the inclination angle and a more realistic model based on the theory of three-body interactions ("regression of the nodes" effect). The nodal cycle is found to be about 600 yr, within which TWO eclipse "seasons" occur, each lasting about 100 yr. The non-eclipsing status of the system is expected to continue until the beginning of the 23rd century.Comment: 32 pages, including figures and tables. Accepted for The Astronomical Journal, April 200

    Analysis of clothing elements reflecting fashion trends in the collection of fashion shows

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    The aim of the work is to study fashion trends, to establish a set of elements through which changes are expressed in models (samples) of collections of fashion shows of clothes, and how these changes are introduced into mass production and are repeated over time. The theoretical significance of the work lies in the development of a methodology for studying clothing samples, identifying fashion trends and making forecasts. The results obtained can be used in training for the formation of competencies among specialists in the field of fashion technology, modeling and clothing design, at industry enterprises for the development of promising collections. The proposed technique was tested, elements of models and materials were identified, the use and combination of which ensures the relative novelty and integrity of the collections, forms a promising trend, which is further implemented in the mass production of clothing

    Influence of Silver and Copper Nanoparticles on the Enzymatic Activity of Soil-Borne Microorganisms

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    Influence of metal nanoparticles synthesized by microorganisms upon soil-borne microscopic fungus Aspergillus terreus K-8 was studied. It was established that the metal nanoparticles synthesized by microorganisms affect the enzymatic activity of the studied culture. Silver nanoparticles lead to a decrease in cellulase activity and completely suppress the amylase activity of the fungus, while copper nanoparticles completely inhibit the activity of both the cellulase complex and amylase. The obtained results imply that the large-scale use of silver and copper nanoparticles may disrupt biological processes in the soil and cause change in the physiological and biochemical state of soil-borne microorganisms as well

    Tides in colliding galaxies

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    Long tails and streams of stars are the most noticeable upshots of galaxy collisions. Their origin as gravitational, tidal, disturbances has however been recognized only less than fifty years ago and more than ten years after their first observations. This Review describes how the idea of galactic tides emerged, in particular thanks to the advances in numerical simulations, from the first ones that included tens of particles to the most sophisticated ones with tens of millions of them and state-of-the-art hydrodynamical prescriptions. Theoretical aspects pertaining to the formation of tidal tails are then presented. The third part of the review turns to observations and underlines the need for collecting deep multi-wavelength data to tackle the variety of physical processes exhibited by collisional debris. Tidal tails are not just stellar structures, but turn out to contain all the components usually found in galactic disks, in particular atomic / molecular gas and dust. They host star-forming complexes and are able to form star-clusters or even second-generation dwarf galaxies. The final part of the review discusses what tidal tails can tell us (or not) about the structure and content of present-day galaxies, including their dark components, and explains how tidal tails may be used to probe the past evolution of galaxies and their mass assembly history. On-going deep wide-field surveys disclose many new low-surface brightness structures in the nearby Universe, offering great opportunities for attempting galactic archeology with tidal tails.Comment: 46 pages, 13 figures, Review to be published in "Tidal effects in Astronomy and Astrophysics", Lecture Notes in Physics. Comments are most welcom

    The Impact of Behavioral and Structural Remedies on Electricity Prices: The Case of the England and Wales Electricity Market

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    During the liberalization process the UK regulatory authority introduced a behavioral remedy (through price-cap regulation) and structural remedy (through divestment series) in order to mitigate an exercise of market power and lower the influence of incumbent producers on wholesale electricity prices. We study the impact of these remedies on the dynamics of the wholesale electricity price during the peak-demand period over trading days. An extended autoregressive and autoregressive conditional heteroscedasticity (AR⁻ARCH) model with a novel skew generalized error distribution is used. This distribution allows one to capture the features of asymmetry, excess kurtosis, and heavy tails. The model is extended to include individual incumbent producers’ market shares and other explanatory variables reflecting seasonal patterns and regulatory regimes. We find that the structural remedy was more successful than the behavioral remedy because the effect of market share of the previously larger incumbent producer on the wholesale price is statistically insignificant. Moreover, after the second series of divestments, price volatility reduced

    Estimating the volatility of electricity prices: the case of the England and Wales wholesale electricity market

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    Price fluctuations that partially comove with demand are a specific feature inherent to liberalized electricity markets. The regulatory authority in Great Britain, however, believed that sometimes electricity prices were significantly higher than what was expected and, therefore, introduced price-cap regulation and divestment series
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