The problem of utilization of iron ore tailings . The prospects of iron ore mining in the Russian underground . A method for extracting iron from tailings to 9 % of the original content, by mechanochemical processing. The results of particle size distribution , chemical and mineralogical analyzes of samples collected waste ferruginous quartzites LGOK . Experiments were carried out using the methods of planning optimal experiments , Box-Behnken and included 24 experience. Obtained according to the content of metal recovery in the leach solution of sulfuric acid , sodium chloride , rotor speed and the ratio of disintegrant liquid and solid phases. This dependence allows to determine the optimal parameters of technology in terms of " metal recovery ." The resulting secondary processing of tailings to be used in the manufacture of hardening mixes for stowing as an inert filler and binder counterpart .
Keywords: tailings, mechano-chemical activation, iron ore, ferruginous quartzites, metal recovery
The results of computational experiments to determine the characteristics of the porous piezoelectric ceramics based on the methodology, including the effective modules method, simulations of representative volumes on a simple random method and the method of Witten-Sander, finite element method to solve static piezoelectric problems for heterogeneous composite media and the accounting of inhomogeneous polarization near the pores are presented. A comparison of the results of computer simulation with the known experimental data for the porous material PZT-4 and its analogs is realized. It is concluded that the accounting of inhomogeneous polarization in the vicinity of porous provide the better agreement between numerical results and large number of known experimental data. Thus, for most effective constants the smallest errors are obtained for a representative volume of the porous piezoelectric material, constructed by Witten-Sander method.
Keywords: piezocomposite, porous piezoelectric ceramics, inhomogeneous polarization, mathematical modelling, models of representative volumes, finite element method, effective moduli
This article deals with the unification of the elements of wood as on the principle of similarity with the material counterpart. Also estimated the economic benefits of the technical parameters of Glulam. As a result of optimizing the size of these elements. Unification is held on the main criterion of similarity bearing members with the solution graphically. Resulting in optimal size sections are then calculated the opportunity cost of production.
Keywords: unification, glued wooden structures
In article the safety mechanism in construction is shown. Main types of monitoring of unique buildings and constructions are opened
Keywords: risk, construction, monitoring, labor protection, safety
In article questions of planning of load-lifting works are reflected and the assessment of category of degree of risk is carried out
Keywords: risk, load-lifting mechanisms, labor protection, safety, technological cards
In article dynamics questions formation of drop ablation at destruction of bubbling streams are considered at a rupture of bubbles, experimental data of some characteristics of processes of destruction of streams are given, the analysis of the factors influencing formation of drop ablation is made
Keywords: drop ablation, bubbling, drop, stream, blanket
The coloration centres (CC) in crystals of rear earth gallium garnets (REGG): Gd3Ga5O12 (GGG), Gd3Sc1,6Ga3,4O12 (GSGG) и Nd3Ga5O12 (NGG) obtained by Chohraljskiy method, were investigated by methods of optical spectroscopy and spectral analysis in the wavelength range of 0,2-0,87 microns. In the case of keeping the samples under dark conditions, unstable CC were formed in the crystals of GGG and GSGG. The absorption maxima are at λmax1 = 0,243 m and λmax2 = 0,275 m at concentration of N ~ 1018 cm-3. It is suggested that the observed enlightenment is caused by the recharging of growth defects and occurring the energy levels in the band gap of garnets. It appears that these CC correspond to centres of O- holes, originated from gallium vacancies V3-Ga 3+ in tetrahedral and octahedral nots which form near clusters of [V3-Ga 3+ - V2+O2- ]
Keywords: color centers, rare earth gallium garnets, kristylly, Czochralski method, the crystal lattice
Belt conveyors are widely used in factories of building materials. They are used to transport bulk and General cargo on the short, medium and long расстояния.Установка the working body of the screw conveyor brushes allows to increase capacity of the conveyor by eliminating the accumulation of the material to be transported inside the gutter.
Keywords: Operating enterprise, belt and screw conveyors, building materials.
Re-equipment of existing enterprises is comprehensive intensification of production, increase production capacity, production and improvement of its quality while ensuring productivity growth and job cuts to reduce material capacity and cost of production, saving of material and energy resources, improvement of other technical and economic performance of the company in General
Keywords: Modernization, технологическоя line, production, ceramic brick, operating enterprise
Is devoted to the actual problem of constructing classifiers objects given by a point in a multidimensional space of feature values. The principle of linear normal classification of objects in multi-dimensional space of attributes can be used to build a classifier in the case of many complex structures, in general, are inseparable one hyperplane. In such cases, proposed to use a set of hierarchically related normal separating hyperplanes, which is called the normal hierarchical classifier.
Keywords: recognition, classification, feature space, the geometric method
In the process of exploitation of the building there is a reduction of its operational reliability in accordance with the inevitable influence of several groups of factors. The two main groups, influencing the technical condition of the buildings was considered
Keywords: operational reliability; technical condition; engineering diagnostics
To date, the main method of mass production of advanced functional materials for various purposes is the ceramic technology. In the manufacture of multi-component oxide compounds using of ceramic technology is difficult to achieve high uniformity of chemical composition. For activation of the raw ingredients and make it more uniform use of chemical-tions (co-precipitation of salts or hydroxides, spray drying, Cryochemistry) and physical-tions (mechano-chemical, microwave, ultrasonic) methods. The paper presents the results of work on obtaining Ni-Zn-ferrite 2000NN radiation-thermal sintering. The influence of base composition and alloying additions on the electromagnetic properties of the ferrites. Confirmed the effectiveness of the use of surface-active additives To increase the density of the raw pieces and level parameters. We propose a model that explain schaya efficiency of dopants in the radiation-thermal sintering.
Keywords: Nickel-zinc ferrite, radiation thermal sintering, base composition, alloying additives, permeability
"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
Discusses various aspects of ensuring effective functioning of the enterprises of the fuel and energy complex. The substantiation of the composition of resources, groups of indicators to assess the efficiency of the fuel and energy complex enterprises. Justified types of resources, define technical and socio-economic development of the enterprise. The author proposes to the elements of production include indicators reflecting the quantitative and qualitative composition of the means of labor, subjects of work and technical equipment. Justified measures on the creation of an interconnected system of indices, which will analyze the changes in the industry with the purpose of planning and realization of actions aimed at sustainable development of the industry in the future.
Keywords: fuel and energy complex; resources; enterprise; sustainable development of the power industry; the effectiveness of the functioning of the fuel and energy complex
Promising absorbing materials along with a Ni-Zn-ferrites are Mg-Zn-ferrites, as they are also intensively absorbs electromagnetic waves in the frequency range from 50 MHz to 1000 MHz. The main advantage of the Mg-Zn-ferrite is used as an inexpensive raw material magnesium oxide. The paper presents the results of research to improve the efficiency of broadband radio-magnesium-zinc ferrite by increasing the contribution of the dielectric loss. The influence of alloying elements of the atmosphere gas and cooling after the sintering thermal radiation by absorption of electromagnetic waves. Confirmed cooling efficiency of products after sintering in an atmosphere with reduced oxygen partial pressure to increase the dielectric constant. A model is proposed to explain the increase in the dielectric loss ferrite during cooling in a reducing atmosphere.
Keywords: radioabsorbing ferrites, microstructure grain boundaries radio measurement radiation thermal sintering