Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
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479 kb

USING DISCRETE WAVELET TRANSFORM FOR CALCULATION OF TRANSIENT REGIMES OF POWER SUPPLY SYSTEMS

abstract 1131509060 issue 113 pp. 814 – 825 30.11.2015 ru 1013
This article presents an algorithm based on the discrete wavelet transform for the analysis of current root mean square (RMS) value and total harmonic distortion (THD) in power systems. Power quality indices play an important role in case of non-stationary distorted waveforms, where neither a frequency-domain-based approach using fast Fourier transform tools nor a timedomain-based approach using real time data give satisfactory results. The algorithm proposed decomposes the current waveforms into uniform frequency bands corresponding to the odd harmonic components of the signal. The proposed algorithm overcomes the spectra leakage problem. Computer simulations verified the effectiveness of the proposed algorithm
153 kb

CHANGE IN THE CONCENTRATION OF NITROUS CONNECTIONS DURING THE FERMENTATION OF MUST BY THE NEW RACES OF YEAST

abstract 1011407045 issue 101 pp. 722 – 731 30.09.2014 ru 1014
We have established a change in the concentration of nitrous connections - amino, ammonium, total nitrogen and protein - during the fermentation of grape must by different races of yeast. Yeast which ensure reduction in the number of nitrous connections at the stage of the active fermentation were isolated
221 kb

APPLICATION OF ELECTRICAL TECHNOLOGIES FOR ENHANCING OF IN-HEAVE MICROCLIMATE

abstract 1061502008 issue 106 pp. 135 – 150 28.02.2015 ru 1015
One of the integrative indicators of over-all performance estimation is profitability of the production. It is possible to increase competitiveness of beekeeping production as well as national food security via implementation of efficient electrical technologies. Enhancing of microclimate parameters in hives allows us to enhance the intensity of spring development of bees. The counting of integrate heat losses in heaves with ozone treatment and without the one was carried out. Using the obtained results and graphs we can develop the automation system for in-heave microclimate control. The article presents the graphs of heat losses in a beehive on the outdoor temperature and relative humidity, which were obtained experimental. It is proved that when the outdoor temperature from -15 to 8 ° C and the change in ambient air humidity of 60 to 100% heat loss beehive decrease from 4-5 W to 0.2-0.4 W. It is concluded that treatment of bees by ozone, while reducing the concentration of pathogenic microorganisms, will reduce the energy loss by reducing the air exchange, i.e. improve conditions for the development of the bee colony
314 kb

CHOOSING THE BEST METHODS FOR ASSESSING THE EFFICIENCY OF INFORMATION TECHNOLOGIES USING THE KEMENY MEDIAN

abstract 1101506052 issue 110 pp. 774 – 786 30.06.2015 ru 1016
The research is devoted to the problem of choosing the best methods for assessing the economic efficiency of information technologies. Using the Kemeny median is proposed to solve this problem. This method will allow to obtain the ranking of methods of evaluating of IT effectiveness by various criteria. The existing methods of valuation of economic efficiency of information technology were systematized in the article. Preliminarily, all the methods were divided into three groups: financial, probabilistic and qualitative analysis tools. The advantages and disadvantages of methods, their purpose, use and limitations were also considered. As a result of systematization, it was concluded that there were some limited and one-sided methods. No single method allows to assess comprehensively the effectiveness of an information technology. Obviously, the methods should be considered in the system. But for this they need to be ranked. In order to obtain the ranking the method of Kemeny median was used. In the beginning the expert evaluation of methods by the eight proposed criteria (taking into account the specificity of the original data, validity, unambiguity, information content, exactness, complexity, the access to information, the cost) was carried out. Next, the search of the group ranking was carried. The matrix of losses was compiled. The problem of appointments was solved in MS Excel. At the end, the matrix of paired comparisons has been obtained. This matrix helped to determine the final ranking of alternative methods. Therefore, using the Kemeny median allowed us to prioritize the use of methods of evaluating of the effectiveness of information technology
366 kb

PROSPECTS OF SMALL HYDROPOWER PLANTS IN THE PIEDMONT AND MOUNTAIN STREAMS

abstract 1121508068 issue 112 pp. 951 – 963 30.10.2015 ru 1016
The article reveals the advantages of low energy in comparison with other renewable energy sources. It is shown that broad prospects are visible for small (100 - 1000 kW) and micro hydropower plants (up to 100 kW) when used in the foothill and mountain areas. At the same time, the construction of hydropower plants of sleeve-type has improved the operational and technical characteristics, among other types of small-scale power plants. The article presents main analytical expressions for calculating hydroelectric power generator and it has built graphic dependences for the power generator of pressure and water flow. To improve the performance of small hydroelectric power plants we have proposed using unregulated water turbine and non-contact induction generator in their construction, thus, we could stabilize voltage and frequency directly by the frequency converter. Depending on the requirements of consumers to power supply reliability and electricity quality, we have offered several options for structural and circuit solutions of autonomous systems of electrosupply, made using small hydroelectric power plants. Thus, we can greatly enhance the efficiency of such systems if they are used with other types of renewable sources, such as windfarms or solar power plants
453 kb

A CENTRIFUGAL DEVICE WITH SUPPLY OF MATERIAL ALONG SHOVELS

abstract 1121508109 issue 112 pp. 1495 – 1507 30.10.2015 ru 1016
Introduction of mineral fertilizers is performed by centrifugal devices. By quantity of disks, centrifugal devices distinguish one disk and two-disk. On the volume of capacities for storage of mineral fertilizers distinguish bunker and body. Bunker contains volume from 0.5 to 1.5m3. Body has capacity more 2m3. Advantages of bunker centrifugal devices are noted. Material from the bunker moves on a centrifugal disk perpendicular to the rotation plane. At the time of material capture by shovels, crushing of particles and their reflection from shovels and the plane of a disk takes place. It leads to increase in unevenness of introduction of mineral fertilizers. At EMTP chair of the Kuban GAU the centrifugal device with supply of material along shovels is developed. The scheme of the centrifugal device is submitted. A device for introduction of mineral fertilizers contains the one-disk centrifugal device, the cone-shaped bunker and the cylindrical batcher. The batcher gate regulates supply of material on a disk. The technique of determination of design and technological data of the developed design is presented. The place of supply of material on a disk is regulated by rotation of the batcher round a vertical axis. The norm of supply of material on a disk changes the batcher gate. Preliminary control of a place of giving is made on model material with coefficient of friction of f 1. Under production conditions, turn of the batcher from initial situation is made depending on coefficient of friction of the f2 fertilizers. At f1 ˃ f2 turn of the batcher against the direction of rotation of a disk, and at f1 ≤ f2 turn of the batcher in the direction of rotation of a disk
617 kb

CHALLENGES AND TECHNICAL SOLUTIONS OF USING HIGH-PERFORMANCE TRANSPORT OF AGRICULTURAL MACHINERY

abstract 1141510073 issue 114 pp. 952 – 977 30.12.2015 ru 1017
Material and technical resources form a large part of the costs in agricultural production and determine the level of intensity of agriculture, productivity and competitiveness of the industry. The most important role in agricultural production is played by transport operation, from productivity and quality of which directly depends the volume and the grade of final products. More preferable is tractor transport, particularly for on-farm transport, taking into account the impact of navigation systems on the ground. Continuous growth in the saturation of tractors carried out around the world, improves the performance of tractor transport aggregate by increasing their capacity and speed, either on the road or in the field. However, if you increase the saturation of tractors, it encounters problems related to the deterioration of the controllability of the tractor and transport unit. The reduced controllability leads to an increase of damage to transported agricultural products owing to increased oscillatory processes in the system of "road – trailer – tractor – operator" when driving on-farm trails, deteriorating the smoothness and braking properties. Especially sharp these questions relate to transportation of easy-to-damage agricultural products at farm transportation. The feature of data traffic lies in the sharp drop in grade products (products receive numerous mechanical damages, deteriorating its quality, and lose marketability and accordingly reduced its cost). Influence on fruit and vegetable products of unfavorable factors can lead not only to a dramatic loss of quality at the time of transportation, but also reduce the resistance during further storage. To solve the problems emerging when increasing the saturation of tractors, we have proposed devices, allowing reducing negative impact on the production of elevated oscillatory processes, to increase the permeability and straightness of movement of tractor-transport unit
1077 kb

EXPERIMENTAL RESEARCH EFFORTS TO UPROOTING TREES AND BUSHES PLANTED

abstract 1021408032 issue 102 pp. 500 – 510 31.10.2014 ru 1019
The article presents the methodology and the results of experimental studies to determine actual values of effort arising from uprooting trees and shrubs plan-tations in the Republic of Mari El. On the basis of experiments and regression analysis we have established the coefficients of the approximation-defining relation between the force and the diameter of the stem of tearing depending on the type of crops
369 kb

MATHEMATICAL MODEL OF REFERRING AUTOMATED SYSTEM DOCUMENTS TO INFORMATION SPHERES OF USERS RESPONSIBILITY

abstract 0921308057 issue 92 pp. 850 – 859 31.10.2013 ru 1021
In the article, we present the mathematical model of referring documents entering the automated system to the spheres of users responsibility. The possibility of application of mathematical apparatus of final predicates algebra as a basic means of model description is proved
162 kb

THEORETICAL SUBSTANTIATION AND DEVELOPMENT OF THE TECHNOLOGY OF SPARING DRYING OF TOMATO RAW MATERIAL WITH THE MAXIMUM RETENTION OF THE INITIAL USEFUL PROPERTIES

abstract 1001406044 issue 100 pp. 712 – 722 30.06.2014 ru 1022
The peculiarities of tomato cultivation and processing grown in Dagestan are considered. The layout of multistory electric dryer allowing drying prepared and sliced tomatoes in an inert gas is described
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