Consider the choice of coating anodes for electrolysis of sodium hypochlorite nizkokontsentrovannogo 3% solution of sodium salt of food and water of the Black Sea. Defined corrosion resistance of anodes with different laying oxides of ruthenium and iridium and their characteristics: yield chlorine-current voltage on the cell growth dynamics of the concentration of active chlorine in the solution.
Keywords: oxide coatings, iridium, ruthenium, low concentration of sodium hypochlorite, the corrosion resistance of anodes according to the output current of chlorine, the electrolysis of a 3% solution of sodium edible salt and sea water.
The article considers the design of modern electrically driven gas-pumping unit (EGPA). The advantages of a smooth adjustment of speed and performance EGPA. Provides an analysis of options for building the power part of the high-voltage frequency converters, used in the composition of the EGPA at compressor stations of main pipelines. Refer to the element base of high-voltage frequency converters. The characteristics of each of variants. The method of work of the frequency converters. Compare the characteristics of frequency converters of various manufacturers. The basic approaches to manufacturing. Defined the most optimal scheme of the power part of frequency converters.
Keywords: frequency converter, topology, design, optimization, structural scheme
Systems of passive damping of oscillations of high-rise constructions are considered. Their merits and demerits are revealed. The roller system of oscillations indemnification of the high-rise constructions subject to seismic influence is offered. The principle of its work is described. Advantages are estimated.
Keywords: high-rise construction, damping of oscillations, passive systems, roller system of indemnification, vibroisolation
Directions of innovative activity of commercial organizations to ensure its development in the competitive, volatile market environment are investigated.
Keywords: commercial organization, management, directions of innovative activity
The paper describes a method to build Jerah krietriev for solving decision making in the management of complex multivariable systems based on functional decomposition . The result of functional decomposition takes the form of an ontology -based posnroennoy deskriptinvyh logic to build a hierarchy of concepts. The advantage of this method is the ability to use it for semi-structured systems. The result of the ontological analysis of the functional structure of the system is the taxonomy, including a description of the processes , organizational structures, and indicators of quality of running processes . When referring to this ontology by using the proposed request is generated hierarchy of indicators , based on the processing of values is carried out and decisions .
Keywords: ontological analysis, systems analysis, ontology, descriptive logic
"Dynamic mode of heat exchangers is typical for a number of technological thermal plants , as well as air-heating systems , ventilation, and air conditioning. Technologically predetermined control algorithm operating mode heat exchangers in practice implemented by means of manual or automatic adjustment in one or more control parameters . Obviously, the most efficient in the energy and technically and economically dynamic mode control algorithm of the heat exchanger can be detected only in the form of a review of the relevant mathematical model. In this paper we consider a mathematical model of the dynamic operation of the system of heat exchangers with natural air circulation . As input parameters are considered the temperature of hot and cold air streams. Modeled by changing the inputs are heat exchangers and the extent to which these changes will not affect the operation of the entire system. In order to keep the temperature at the i- MOT has not changed , the coefficient of variation should tend to zero , since all the other quantities are limited by technical parameters of the system . By changing the values of the input parameters is analyzed mass flow of hot flow limits are changing the output parameters of the preceding heat exchangers that will not change the entire system ."
Keywords: heat loss into the environment, the starting temperature of the hot (cold) flow, the final temperature of the hot (cold) flow, the range of variation of hot, cold flow
Currently actively developing direction of seismic protection, the identified using absorbing screens made in the form of sandwich structures. The present paper presents a design руктивная scheme of energy absorbing panel, which allows you to raise, if used, seismic stability of constructions.
Keywords: Dynamic loading, uprugoplastichesky deformation, deformation chart, power absorption
The problem of air quality control is relevant at the present time. There are a lot of different devices and methods of air monitoring. The promising devices for air monitoring are automated air monitoring systems functioning in real time regime. The basic part of such system is a chemical gas sensor. Gas sensors can be combined into the arrays or so called multisensory systems to increase their effectiveness. Sensor arrays using semiconductor sensors based on SiO2CuOx, SiO2SnOxCuOy, SnOxZrOy, silver-polyacrylonitrile thin films made at department of chemistry and ecology have been investigated in this work. As a result of sensors signals processing gas recognition technique has been developed. The recognition of ammonia, nitrogen dioxide, chlorine has been made.
Keywords: monitoring, massifs of sensors, semiconductor sensors of gases
We have investigated electrical and gas sensitive properties of gas sensor based on carbon nanotubes (CNT) and carbon nanotubes modified by metal oxides (such as tin oxide and silicon oxide). Also we have find out that modification of CNT by metal oxides helps to improve film`s adhesion to substrate, decrease electrical resistance, recovery time, working temperature , enhance gas sensitivity in comparison with sensitive elements based only on CNT or metal oxides. Moreover experimental results showed that properties of composite material depend on concentration correlation of solutions. As a result we can get highest sensitivity of sensor element by choosing optimal relation between concentrations of solutions.
Keywords: Сarbon nanotubes, modification, tin oxide, silicon oxide, gas sensor
Information about authors of issue №4 (2013)
In this work the technology of receiving high-sensitivity gas sensors on the basis of zirconium oxide is developed for hybrid sensor systems. Laboratory samples of sensors of gas on the basis of zirconium oxide are made with use sol-gel method. Gas-sensitive characteristics of samples of sensors in relation to nitrogen dioxide are defined: limit of detection and factor of gas sensitivity. The received gas sensors will help to determine approach of an attack of bronchial asthma some hours prior to its beginning by level of an oxide of nitrogen in exhaled air of the person.
Keywords: hybrid sensor systems, zirconium oxide, bronchial asthma, nitrogen dioxide
The article is devoted to the resistance accounts composite structures. It is based on all-covariance-energy principle. We consider the calculation of the stress-strain state of construction, consisting of a base in the form of hexagonal plates, rigid base related to the circular cylindrical shell.
Keywords: plate, shell, variation-energy principle, the strength, the composite structure.
The article is devoted to the resistance accounts composite structures. The basis of the position of women variational energy principle. Considered potential energy flanging to calculate the stress-strain state of construction, consisting of a base of the form of hexagonal plates, rigidly connected to the base of circular cylindrical shells, the upper end of which is enhanced by the hexagonal crimping.
Keywords: plate, shell, variation-energy principle, the strength, the composite structure
The article is dedicated to increasing the strength properties of building structures based on bionic principles. Used research on modeling of plant materials. The different types of window openings. The recommendations to improve the strength of the restoration works for the construction of openings.
Keywords: shell, strength, mesh structure
The article is devoted to the modeling of plant material and to increase the strength properties of building structures using bionic principles. The different kinds of structures reinforcing fabric leafy plants. Recommendations on the use of reinforcement cages during restoration work in construction.
Keywords: shell strength, plant, reinforcing fabric, building construction