The techniques generate a directivity diagram a slot antenna array with variable polarization. The results of calculation the characteristics of radiation for an array dimension 4x4 elements.
Keywords: AESA, microstrip antennas, spacecraft, remote sensing of the earth.
The kinetics of the electrodeposition of zinc to the steel base of the sulfate electrolyte supplements with synthetic surfactants was studied. Found that at potentials more positive than the equilibrium value the process of pre phase zinc deposition. Additives synthesized organic compounds adsorbed to the surface of the electrode at its cathodic polarization, increasing of overvoltage process. The adsorption is in the range of 0,5•10-7 to 2,6•10-5 mol/сm2.
Keywords: zinc, electrolyte, electrode, surface-active agents (surfactants), electrodeposition, adsorption, diffusion coefficient, and pre phase deposition
The paper studies the possibility of quantitative processing of the GPR data for determining the dielectric permittivity and conductivity of a medium (soil samples). Experimental studies are made using radargrams of soil samples with specified values of moisture and conductivity. New methods of quantitative processing of radargrams are proposed in this work to determine the dielectric permittivity and conductivity of soils. The methods were successfully tested on various sections of Russian railways net.
Keywords: layered road profiling, GPR, soil moisture, soil layers profiling, soil conductivity
This work deals with the study of atomic and electronic structure of kaolinite samples (Glukhovtsy deposit) and montmorillonite (Millerovsky deposit) by density functional theory. The applicability of existing exchange-correlation potential in the local density approximation (LDA) and the generalized gradient approximation (GGA) is analised for an adequate description of the physical properties of layered aluminosilicate. An experimental and theoretical study of the IR spectra of minerals, as well as the identification of the most intense absorption bands, performed in the approximation of DFT using the exchange-correlation potential PW91. The analysis of the band structure of these minerals, which showed that these compounds are direct-gap insulators.
Keywords: DFT, clay, clay minerals, phyllosilicates, atomic and electronic structure, crystalline systems, IR spectrum band strukutra, the electron density
This work deals with the integrated study of the composition and structural characteristics of the rock-forming minerals in Millerovsky bentonite clay. The qualitative and quantitative analysis of the clay samples is made by X-ray diffraction , X-ray photoelectron spectroscopy and thermal analysis . The morphological and microstructural features of minerals are investigated by scanning electron microscopy. The application of the method of direct theoretical calculation of the diffraction patterns is showm to determine the crystal-chemical parameters of the studied minerals. The results are aimed at explaining a number of physical and chemical properties of layered aluminosilicate.
Keywords: clays, clay minerals, layered silicates, x-ray diffraction, crystalline systems
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
Tendencies of technological improvement of electronic chips led to reduction of their sizes, weight, development of functionality and decrease in power consumption. It allows us to discuss questions of developing renewable micro power sources which can provide power supply of autonomous microelectronic and micro circuitry systems for charge indication, paying attention to snow transfer, etc.
The purpose of the paper is researching a profile of electrostatic field potential in the mountain district which was estimated as a possible use as a renewable micro power source.
It is found out that on windward sides of snow relieves the potential of electrostatic field exceeds three times to a similar indicator for lee sides and is 80 V. The potential is 3,5kV on polymeric surfaces (Nylon, teflon).
Keywords: snow storming electricity, electrization, potential of electrostatic field, charge, the salting, the loaded particles of snow, innovation electronics, micro circuitry, renewable micro power sources.
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
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
To solve the traffic problems , namely the coordination of the movement of transport modes have been developed micro-and macro-modeling programs that predict traffic situations , to choose the most appropriate solutions for specific problems by using real data and statistics. The emergence of intelligent transportation systems, traffic simulation pushed to the fact that it has become one of the most used methods for studying the traffic flow, allowing to plan and predict the situation on the roads. The possibilities offered by the modeling of traffic flows , helping to simulate the situation on the roads, and it becomes a unique tool for understanding the complexity of transport systems. For precise work of model needs an indicator such as the time of the trip. Travel time - the time it takes to travel from one point to another , consisting of travel time and the stop time of the vehicle.
Keywords: travel Time, microsimulations , flows, methods of intelligent transport systems
In article statistical data on failures on a linear part of the main gas pipelines are presented, the reasons of their emergence are defined. Standard scenarios of development of emergencies are provided, and also the basic principles of determination of frequency of emergence of failures are shined.
Keywords: accident, analysis, diameter, linear part of the main gas pipelines, depressurization, scenario, pipeline.
In article questions of pilot studies of disperse structure of drop ablation are considered when putting electroplated coatings, the technique of performance of experiment is given, the design of experimental installation is considered, results of researches of dependence of height of take-off of drops of ablation over an electrolyte surface from their effective radius are given
Keywords: electroplated coatings, drop ablation, bubbling, drop, height of take-off of a drop, effective radius of a drop
В данной статье приводятся примеры стандартных и не стандартных точек контакта с потенциальными клиентами, описаны механизмы их выявления, а также приведены примеры из практического опыта работы авторов по данной теме. Дано определение понятию «клиентоориентированнсть» с точки зрения клиента, и предложены варианты, где применима данная стратегия. Поднят вопрос о качестве обслуживания и что стоит за этим пониманием для клиента, чего он ждет от сферы услуг и на что рассчитывает. В статье рассмотрены этапы анализа точек контакта, приведены примеры влияния этих точек на формирование лояльного отношения клиента к качеству услуг.
Keywords: услуга, точки контакт, идентификация, стратегия, анализ, клиент, потребитель, контакт, точки взаимодействия, ориентация на клиента
This paper presents a comparative analysis of the effectiveness of the method Cuthill-McKee algorithm and fill-reducing ordering of a sparse matrix, based on multi-level nested dissection paradigm, developed at the Department of "Computer Science and Engineering," University of Minnesota. For short, we shall call the algorithm Cuthill-McKee CM, and the algorithm of the University of Minnesota — NodeND (Node nested dissection). This article uses a modification of the CM algorithm — RCM (reverse Cuthill-McKee), because in practice the reverse numbering index allows you to get a greater advantage than using a direct algorithm CM. The reason for using these algorithms are high speed computational algorithm, as it is necessary to solve the system proximal to the diagonal, the great acceleration of algorithms for solving FE problems using technology such as CUDA
Keywords: finite element mesh renumbering methods, three-dimensional mathematical modeling, elasticity theory problems, finite element method, finite element meshes
Considered the organizational and technological systems in monolithic housing construction as the elements of the organization and management of the construction of production. Offered a choice of variability of the production apparatus , determine the most effective scheme of the system organization monolithic construction . It is recommended the formation of a number of consecutive and concurrent source OTSS interconnected unity of purpose , time and place of the action. Developed of activities that provide improved use of construction equipment.
Keywords: organization, technology, building systems, modeling, research, quality, communication, production, operation