This article presents the rationale for the selection of measuring instruments (strain gauges) for testing light steel thin-walled structures (LSTC) to determine the stress-strain state. Article discrebes in detail optimal sensor's installation locations, the required measures for correct value.
Keywords: thin-walled profile, test, frame, strain gauge, compression, tension, tension, bending, loss of stability
Phantoms are an imitation of biological tissue. With the help of phantoms, it is possible to simulate the propagation of light in biological tissue. During any biophysical experiments there is a need for the constancy of the initial conditions of the experiment. The use of solid phantoms that do not degrade over time and under the influence of external factors is the Foundation for reliable results and repeatability of the experiment. The creation of phantoms of biological tissue containing fluorescent nanoparticles or nanoparticles with high absorption, and which correspond to specific mechanical or optical properties, is an urgent task. The paper describes the development, fabrication and characterization of solid tissue phantoms containing gold and upconversion nanoparticles. Optical and mechanical properties of phantoms are studied. The temperature range suitable for the use of samples as phantoms of biological tissue for laser thermolysis problems was revealed.
Keywords: phantom, gold nanorods, luminescence, quantum dots, thermogravimetric analysis
The paper reveals data on the development of simulation models of integrated circuit pulse voltage converters for applying in automated measuring equipment used in the tests of integrated circuits. The integrated circuit of switching voltage converter LM2676 was simulated taking into account heat generation and taking into account the mutual influence of crystal temperature on external electrical characteristics as part of a general behavioral model.The authors obtained results and dependences, coinciding with the experimental data and with the SPICE model at the transistor level, that reflects the influence of the crystal temperature on the the chip operation. In addition, the authors consider a possibility of using behavioral models as a source of reference information in the process of testing electronic components.
Keywords: ATE, integrated circuit (IC) testing, switching voltage converters, behavioral model, VHDL-AMS
In article the situational centers operating in the territory of Russia in the educational sphere are considered, their classification is offered and need of expansion of functionality of their activity is revealed. The structural model of the innovative situational center within the certain region allowing to carry out processing of big data arrays that will increase efficiency of decision-making process in crisis situations is developed. This model is universal and applicable to any region.
Keywords: situational center, education, model, region, information systems, management, digitalization, information system
The paper presents the systematization of the main methods for increasing the rigidity and stability of the cable-stayed and hanging types bridge structures , its given in conjunction with the analysis of the real objects. Among the methods presented are such techniques as: improving the quality of the material; additional structural elements that perceive vibrations; modification of the main elements of the design scheme. Also in the paper innovative developments applicable in the field of study are described.
Keywords: transport structure, bridge, cable-stayed bridge, suspension bridge, bridge construction, guyed, pylon, rigidity of the bridge structure, stability of the bridge structure, operational safety of the bridge, aerodynamics of the bridge
This article raised the topic of choosing the best method of fire protection for structures consisting of light steel thin-walled elements. Attention is paid to experiments on samples that have different protection against the effects of fire, both in materials and in design. It tells about a new multi-layer method of protecting thin-walled metal structures. The findings of these tests are given and recommendations are given to increase the fire resistance of the above structures.
Keywords: fire protection, fire resistance, frame, LSTK, experience, testing, multi-layered, recommendation, house building, cold-formed profile
By centrifuging it is possible to manufacture a wide range of building structures and products from reinforced concrete. Such products have several advantages, being relevant in modern construction, however, it requires careful compliance and quality control of the process. The frost resistance of concrete is one of the main indicators characterizing the durability of such building structures as reinforced concrete pillars of power transmission lines and contact network. The analysis of the literature and a series of experimental studies in the laboratory. The influence of the technology of manufacturing products from heavy concrete on the indicator of their cold resistance has been identified and determined.
Keywords: Racks of power transmission poles, racks of supports of the contact network, centrifugation, vibrating, frost resistance, heterogeneity of concrete, variotropy
The paper presents the classification of the main causal aspects of the occurrence of catastrophes of large-span bridge structures, given with elements of the analysis of actual examples of the destruction of structures of various types. Also are described the innovative developments applicable in the field.
Keywords: fatigue failure, bridge, large-span bridge, failure of structures, destruction of bridge structures, accident in construction, resonance, wear, aerodynamics of bridge structures, stiffness beam, bolted joint
In the article we discuss temperature errors caused by non-stationary thermal processes in a thin-film Hall transducer. When solving the heat conduction equation we show the significant influence of effects of Peltier and Seebeck on the Hall voltage measurement results in the current switching mode. A new twenty-step switching currents algorithm for the Hall transducer is proposed. In this algorithm the additional voltages are measured at the absence of current through the transducer. From the additional voltages we estimate the contribution of the temperature drift. It was experimentally shown that for the PHE602117 converter the additive temperature error decreases by 30 times in comparison with the four-step algorithm while reducing performance by 20%.
Keywords: Hall transducer, additive error, Peltier effect, non-stationary processes, thermo-emf., magnetic measurements, current switching
The structural properties of cobalt catalysts and their active component are studied. The influence of metal oxides on the specific surface area, pore volume and size, the average crystallite size and the active surface area of the catalyst Co-Al2O3/SiO2 was studied.
Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, cobalt, promoter, carrier, specific surface, porous structure, catalytic activity, degree of reduction, active surface area
The physical and chemical properties of cobalt catalysts promoted by manganese oxides for the synthesis of hydrocarbons by the Fischer-Tropsch method are studied. The influence of polymorphic modifications of the alumina carrier on the specific surface area, pore volume, degree of reduction, size of cobalt crystallites,catalytic activity, dispersion degree of catalyst reduction is considered.
Keywords: Synthesis of Fischer-Tropsch, synthetic hydrocarbons, the cobalt catalyst, promoter MnO2, the carrier of Al2O3, specific surface area, the degree of recovery of the catalytic activity, dispersion, and the crystallites of cobalt
The article presents an analysis of promising research on the formation of vibrational mechanochemical coatings from the point of view of practical use in the real sector of the economy
Keywords: combined methods of treatment, vibration treatment, the vibration mechano-chemical (chemical-mechanical) coverage webrevolve technological system, mechanical coating, fragmentary nature, plastic deformation, uniform coating, vibrowave impact, microstructu
Article is devoted problems of safety of traffic. In given article are sounded a number of the reasons of occurrence of failures on highways. In article questions of influence of psychophysiological features of drivers on occurrence accidents are considered. The special attention is given that use of cellular telephones by drivers (despite prohibition by traffic regulations), and also every possible advertising materials in sight of drivers do not promote concentration of attention on driving process. Also in article questions of increase of safety of pedestrians, as participants of traffic are mentioned. In article the interrelation between road conditions and safety of traffic is investigated. That fact is marked, the reasons of adverse influence of road conditions can be obvious and hidden. In article the developed practice of roads design is analyzed. The given practice, in a due measure, does not consider requirements of landscape designing. Which, in turn, though are registered in the arch of rules, but have recommendatory character. Also in article questions of use of the minimum parameters of highways are mentioned at its designing.
Keywords: Safety of traffic, accidents , a highway, the driver, the pedestrian, roads design, a road condition, road conditions, intensity of movement, the road maintenance, landscape design of road
In the article the features of application of logistic approaches of the organization of movement of the cable cars, as well as the method of selecting the cable car and the slopes at various characteristics of the operation of the complex. The results of experimental research on the network of cable cars of the mountain resort "Rosa Khutor"are offered. The paper uses the methods of monitoring the movement of passengers on cable cars by means of identification by ski pass and GPS
Keywords: transport mobility, route network, public transport, automated monitoring of passenger traffic, logistics approach, cable car, monitoring of cable car congestion on-line, traffic volume, digital transport management system
The model of the occurrence of failures as a result of aging of insulation materials of power cable lines is considered. It is shown that the residual life depends on the ratio of the safety margin and the ultimate strength of the materials used. A simulation of the resource actuation processes was carried out using a mathematical model of the insulation state that relates the time and probability of its trouble-free operation with certain parameters of it. The model allows to predict the state of the insulation and the service life of the power cable lines.
Keywords: Reliability, life, insulation materials, heat aging