In the present work proposes a specified description of potential functions when the free spreading in the two-dimensional turbulent flow of planning. In contrast to previous decisions, new parameter satisfies the continuity of flow when the flow flowing from rectangular tubes on the discharging track
Keywords: final line of motion, lines of equal potential, horizontal rectangular tube, diverting from the mainstream flow
In this paper is offered hydraulic sensor to measure the kinematic, power and energy parameters. Developed scheme and the principles of the hydraulic sensor. Identification on the special flow lab with real modes of the device is determined by its performance in different conditions. Approximation of the results received dependences flow and pressure drop characteristics on the speed and entrance pressure, allowed more correctly assess and describe the operation of the hydraulic sensor over the entire range of speed and entrance pressure.
Keywords: hydraulic sensor, spilling method, flow and pressure drop characteristics, multifunction control unit.
An analysis of the problem of increasing the efficiency of the functioning of the logging trucks for hauling timber to the lower timber depots and consumers. Proposed technical solutions for of raising cross-trains in complex natural and industrial environments.
Keywords: Active semi-trailer used forestry, passableness, prosary operation.
The temperature dependencies of the main parameters of p-channel MOSFET model in a temperature range 20 ... 300 K are measured. The universal formal four-parametric model, which allows approximating all experimental temperature dependencies with the relative error less than 1 % is proposed. The model is intended for the MOSFETs which are applying in low-noise amplifiers of the radio-receiving devices of an optical and infrared range on astronomical satellites, radio telescopes and space observatories. The presented results can be used to simulate the temperature modes of MOSFET amplifiers in SPICE-type electronic simulators. The solution of this problem will predict uptime device when the temperature changes in the cases of emergency or extraordinary situations and also will allow optimizing the choice of refrigerant and increasing the reliability of the amplifier in the conditions of cryogenic temperatures.
Keywords: MOSFET, MOSFET parameters, cryogenic temperature, parameters measurement, temperature dependencies
A mathematical model of a surface mini-ship "Neptune", including a mathematical model of the actuators. Used to identify the parameters of the mathematical model. analysis of stability and controllability of surface mini-vehicle for its mathematical model.
Keywords: mathematical model, surface mini-ship, handling, stability
The method of digital parametric measurement of the phase shift of signals with slowly varying amplitudes of the same slowly varying instantaneous frequencies was proposed. The numerical simulations and experiments on the developed hardware and software system were carried out. The error of measurement the phase difference of harmonic signals in the experiments were not more than 0,00001 radian. The method can be used in applications where the measured value is expressed in terms of the phase difference of quasi-harmonic signals.
Keywords: quasi-harmonic signal, phase shift, real time measurements, hardware and software system
In this paper a systematic study of individual single-walled and multi-walled carbon nanotubes was performed by Raman spectroscopy and high-resolution electron microscopy. We have presented the geometrical and electronic structure analysis on the examples of two tubes: individual single-walled and double-walled nanotubes. The role of different environmental effects and their influence on the final structure assignment are discussed. Moreover, we have shown that the Raman spectroscopy gives reliable estimations of the nanotube diameters and the conductivity. Given a non-destructible character of Raman spectroscopy, we may conclude that it is one of the most efficient methods for structure analysis of carbon nanotubes.
Keywords: Carbon nanotubes, Raman spectroscopy, electron microscopy
Proposed by parallel implementation structures aloritmicheskih simulating year-round circulation of water bodies. The research evaluation of computation time, find the optimal algorithm for the implementation of independent calculations for multi-core processors to reduce the computation time.
Keywords: parallelization of computations, thermohydrodynamics modeling of water objects, multi-core processors
This article describes the model of the pseudorandom sequences (PRS) generator developed in OrCAD program suite.The described model is applicable for radio systems modules circuits simulation that are using in the operation a PRS. The PRS generator implementation in OrCAD make possible to change PRS parametres immediately in the program, without using other software. A model specificity is that it is parametrised. Parametrization facilitates model control and that is reduce to a minimum necessary manipulations for changing of PRS type. The model is constructed on the basis of circuitry implementation of the linear feedback shift register (LFSR). For adjustment of model it is enough to instal code words setting starting state a LFSR, parametres of a signal of a clock source and to specify register tap output. As an example, used a 16-bit LFSR to create maximum length PRS, tap sequence {0, 5, 9, 13}. Emulation results are presented.
Keywords: pseudorandom sequence, PRS generator, LFSR, OrCAD, circuit simulation
In the paper we consider the energy efficiency of electric trains in overcoming the curved portion of the profile path. In this paper, were synthesized motion control algorithms that will help conserve energy resources by means of changes in traffic patterns electric depending on the profile path. The simulation electrorolling stock motion by offer the model showed a reduction in energy consumption compared to the nominal operation.
Keywords: energy efficiency, electric train, traffic management, motion control algorithms, reducing the consumption of energy resources
Chlorination is the most common, and in fact no alternative method of disinfection using in Baghdad water supply system. Thus there is an urgent need to control the trihalomethanes (THMs) in drinking water. One of the objectives of this study is to investigate the content of THMs in Baghdad water supply network. Studies showed that the substantial amount of THMs formed in water distribution system, THMs content tends to increase with the distance from the starting point coupled with a decrease of residual chlorine concentration. It is observed that in summer total THMs concentration growth rate in water supply network was 1.3-1.4 times higher than in winter as well as total amount of THMs increase by 30 percent in summer. It was found that the concentration of total THMs never exceeded 80 μg/l – the level specified in National Primary Drinking Water Regulations: Disinfectants and Disinfection Byproducts (Stage 1) established by USEPA. However, in summer total THMs concentration in the water always exceeded 40 μg/l – the level set in accordance with Stage 2 of this Rule. The most of total THMs (73-80%) were bromine compounds (CHCl2Br, CHClBr2 and CHBr3). It is shown that the most efficient way to reduce THMs in Baghdad water supply network is to use the chlorine dioxide for chlorination.
Keywords: chlorine dioxide, chlorination, drinking water, trihalomethanes (THM), water supply network, water supply system
The represented approach of dynamic process modeling is based on the technology of automatical semantic text analysis. An associative network is forming during text processing. Its key notions, including lexical and psycholinguistic markers of the analyzed process, are ranked by theirs semantic weight. The weight being multiplied by marker status value at the scale of “good-bad” gives its contribution to the process stage characteristic. Transformation of the accumulated for all of the markers process characteristic from one period of time to another one is characterize a direction of the process.
Keywords: automatical text processing, associative (homogenous semantic) network, process dynamic modeling, social processes, lexical and psycholinguistic markers
The article discusses a method for optimizing the synthesis of digital state machines for solving tasks of search patterns with masks on FPGA using automatic models. Standard methods for the synthesis of the FPGA don't optimize digital state machines, but only optimize the placement of logic elements on the chip. The method of vectoring states involve the decomposition the structure of the machine and the combining the variety of states to the vertex-array of states. The states in the vertex-array is controlled by special state machine. This simplifies the addressing to the heights of states of the graph , and optimizes logical structure of machine. The number of states of the digital machine remains unchanged. Vectorization of states is simplifying the synthesis and control of state machine and reduces the number of logical elements.
Keywords: digital state machine, graph of digital state machine, synthesis of digital state machine, FPGA, reconfigurable computing system, pattern search, vectoring states of digital state machine.
The subject of the article is a two-level optimization system of thermal processing of pellets mode within an automated control system of technological process of a horizontal-grate machine. At the top level the problem of the static optimization of the mode is solved periodically based on a mathematical models of a technological zones. At the bottom level, the pellets layer's immeasurable parameters are estimated with a help of a state observer and the optimal thermal processing mode is being stabilized.
Keywords: horizontal-grate machine, mode optimization, mathematical model, state observer
The results of a patent search in the field of shut-off valve constructions for nuclear power plants, thermal power plants and main piping are given.
Keywords: Nuclear power plants, shut-off valve, construction, main piping