Empirical dependence of the probability of blocks rotations on the diffusion coefficient in a cellular automaton with a Margolus neighbourhood

The paper considers a cellular automaton approach to modeling physical processes, in particular, the diffusion of pulsed periodic gas discharges in plasma. An attempt to determine the dependence of the probability of the block rotation on the diffusion coefficient for a cellular automaton diffusion model with a Margolus neighborhood is describe. Some features of the tensor approach to the implementation of random block cellular automata are described. The results of computer experiments are presented. The analysis of this results indicates that the data from the literature sources differ from the data obtained during the experiment.

The influence of joint geometry of toneholes with the main bore of wind musical instruments on their frequency characteristics

The article discusses the influence of geometric parameters (the presence and magnitude of the radius of curvature) at the junction of the toneholes with the main bore of the air column on the frequency characteristics of woodwind musical instruments. A theoretical calculation of the eigenfrequencies of an air column with one tonehole in the case of sharp edges has been carried out. The resonance frequencies were also found using computer simulation in the COMSOL Multiphysics 5.5 program for the case of sharp edges and joints with a radius of curvature. An empirical dependence of the frequency of the main tone of the air column on the radius of curvature of the edges of the tonehole is obtained. All simulation were carried out for two models: excluding and including viscous drag and thermal exchange losses.

EMPIRICAL DEPENDENCE OF THE HYDRAULIC RESISTANCE OF THE WA-TER LAYER OF THE REGULAR PACKING ON THE RESISTANCE COEFFI-CIENT AND IRRIGATION DENSITY

A criterion equation for the coefficient of hydraulic resistance of a layer of regular packing was ob-tained, and a dependence was obtained that connects the hydraulic resistance of a dry and irrigated packing.

DETERMINATION OF WIRE SWING BOOM OF OVERHEAD POWER TRANSMISSION LINES IN ICE FORMATION MONITORING DEVICE BASED ON PHYSICAL SIMULATION RESULTS

Стрела провеса является важным параметром для безопасной эксплуатации воздушных линий электропередачи и может быть использована в качестве одного из основополагающих критериев анализа интенсивности гололедообразования. В данной статье рассматривается возможность определения стрелы провеса при закреплении на одном из проводов фазы датчика, измеряющего угол между проводом и плоскостью земли в непосредственной близости от опоры. Для формализации эмпирической зависимости был проведен натурный эксперимент, моделирующий физические свойства провеса провода ВЛ, размещенного на опорах. Обработка полученных данных и аппроксимация эмпирической функции была реализована в среде MATLAB. После обработки данных была получена эмпирическая функция, которая может быть использована в автономных системах мониторинга для контроля стрелы провеса провода. Автономное устройство мониторинга гололедной обстановки на проводах ВЛ, разработанное авторами, для которого была найдена рассматриваемая эмпирическая зависимость, позволяет следить за интенсивностью гололедообразования, а также контролировать массу гололедных отложений и среднюю толщину стенки гололеда. Информация о гололедной обстановке передается на диспетчерский пункт посредством GSM модема. Увеличение интенсивности гололедных отложений вызывает увеличение стрелы провеса провода, относительно его колебаний, обусловленных технологическими параметрами, поэтому система мониторинга гололеда включающая анализ угла провеса провода является аналогом тензометрических датчиков тяжения, но не требует реконструкции ВЛ и отключения последней на время модернизации. Устройство оборудовано также дополнительными датчиками, что позволяет увеличить вероятность правильного обнаружения опасной гололедной обстановки. The sagging boom is an important parameter for the safe operation of overhead power lines and can be used as one of the fundamental criteria for the analysis of ice formation intensity. This article discusses the possibility of determining the sagging boom when a sensor phase is fixed to one of the wires, which measures the angle between the wire and the ground plane in the immediate vicinity of the support. To formalize empirical dependence, a full-scale experiment was conducted that simulates the physical properties of the LL wire held on supports. The processing of the obtained data and the approximation of the empirical function were implemented in the MATLAB environment. After processing the data, an empirical function was obtained that can be used in autonomous monitoring systems to control the wire sagging boom.An Autonomous device for monitoring the ice situation on the overhead lines, developed by the authors, for which the empirical dependence was found, al-lows to monitor the intensity of ice formation, as well as to control the mass of ice deposits and the average thickness of the ice wall. Information about the ice condi-tions is transferred to the control station via GSM modem. An autonomous device for monitoring the ice situation on VL wires, developed by the authors, for which the considered empirical dependence was found, allows you to monitor the intensity of ice formation, as well as control the mass of ice deposits and the average thickness of the ice wall. Ice information is transmitted to the control room via the GSM modem. Increasing the intensity of icy deposits causes an increase in the wire sag boom relative to its fluctuations due to process parameters, therefore, the ice monitoring system including analysis of the wire sag angle is an analogue of strain gauges, but does not require reconstruction of the VL and disconnection of the latter during modernization. The device is also equipped with additional sensors, which increases the probability of correct detection of a dangerous ice situation.

DESCRIPTION OF CHITOSANE GRAFTED ACRYLIC ACID BASED HYDROGEL SWELLING KINETICS AND THEIR USE IN NEW DESIGNED SYSTEM

Chitosan based hydrogel was synthesized via free-radical polymerization in a two-step procedure, after modification of chitosan by acrylic acid. Dynamic swelling test was carried out in distilled water at room temperature. Swelling kinetics was modeling using the principle of assuming the equation for a swelling ratio-time empirical dependence. Using regression analysis in this way gives the possibility for simpler determination of swelling ratio-time empirical dependence, knowing the graph functions. Obtained hydrogel was used for preparation of new bilayer hydrogel system which has potential application in wound dressing systems and other fields where pH sensitivity and improved mechanical properties of biopolymers are required in framework of green, cost-effective process.

Determination of the parameters of local reinforced zones under the protection means

In order to develop effective measures to ensure the operational condition of the development workings behind the face in the conditions of soft footwall rocks, the construction of local reinforced zones under the protection means has been proposed. The presence of such zones allows transferring the current load deep into the massif and creating a stable foundation under the protective structure. The results of researches concerning establishment of rational parameters of local reinforced zones with application of the method of finite elements, the method of experiment planning and the method of statistical processing of these results have been presented. The empirical dependence of the subsidence of the local reinforced footwall under the protection means on their load, deformation characteristics of the local reinforced zone and host rocks, width of protection means, strength of soft underlying rocks and geometric dimensions of the zone has been determined. The relative indicator of efficiency of local strengthening of a footwall which is used for determining of rational parameters of a locally reinforced zone has been offered.

MODELING OF THE OPERATIONAL SITUATION IN THE EXCLUSION ZONE

The urgency of the work is due to the objective dynamics of changes in the level of man-made and natural threats in the exclusion zone and unconditional (compulsory) resettlement, increasing the volume of taskssolved by operational and rescue units of the State Emergency Service of Ukraine, the need for security people who are, work and live in the Exclusion Zone. Potential threats and dangers in the exclusion zone and unconditional (compulsory) resettlement have been identified. The analysis of statistical data on the involvement of fire and rescue equipment for firefighting. The empirical dependence of the involvement offire and rescue equipment of the State Emergency Service of Ukraine on the elimination of fires in the exclusion zone during the year on their number has been established. It was found that most often 4 to 7 units of fire and rescue equipment of the State Emergency Service of Ukraine are involved in extinguishing fires. Based on the processing of numerical analysis of statistical data, the following conclusions were made: 95% of the time during the year, fire and rescue units are on duty (without calls); 438 hours a year put out single fires; Two hours a year, two fires are extinguished simultaneously. The analysis of calls by service time is carried out. It is established that the service time of calls of fire and rescue units in 25% of cases is up to 2 hours and in 22% of cases is 7-8 hours. An assessment of the locations of fire and rescue units and forest posts with the definition of their service areas. As a result of calculations, it was established that to ensure the normative response to fires at existing facilities in the exclusion zone, it is necessary to provide 4 additional locations of forces and means of fire and rescue units, as well as to ensure the functioning of the fire station on the Vector complex.

Experimental study of heating of a polyurethane shock absorber under cyclic loading

Based on the results of the experiments, an empirical dependence was obtained to determine the heating temperature of polyurethane shock absorbers of different hardness under cyclic loading, depending on the relative compression deformation, loading frequency and vibration amplitude. Keywords: polyurethane, shock absorber, heating temperature, empirical dependence. [email protected]

Calculation of the frequency of own oscillations of polyurethane shock absorbers used in shipbuilding

В работе приведено обоснование необходимости применения амортизаторов и замены традиционного эластомерного материала резины на более совершенный материал – полиуретан. Целью работы является экспериментальное исследование деформативности полиуретанового виброизоляционного массива амортизатора и получение расчетной зависимости для определения собственной частоты колебаний системы «агрегат-амортизатор». В работе представлен подробный анализ зависимости коэффициента виброизоляции от соотношения частот вынужденных и свободных колебаний. Отмечено, что эффективность виброизоляции тем выше, чем больше это соотношение частот. Учитывая, что частота вынужденных колебаний - величина заданная, для повышения эффективности виброизоляции следует понижать частоту собственных колебаний амортизатора благодаря применению новых виброизоляционных материалов. В качестве эластомерного материала предложен полиуретан фирмы «Synair» (Великобритания) твердостью 40,45 и 50 ShA. Приведено описание нагружающего устройства для исследования деформативности виброизоляционного массива амортизатора серии КАС (корабельный амортизатор сварной). Получена эмпирическая зависимость коэффициента ужесточения в зависимости от коэффициента формы виброизоляционного массива амортизатора. Представлена эмпирическая зависимость по определению модуля упругости эластомерного материала виброизоляционного массива амортизатора в зависимости от условий контактирования на торцах и фактора формы массива. Представлена расчетная зависимость по определению частоты собственных колебаний амортизатора в зависимости от величины статической деформации. Представленная зависимость позволяет на стадии проектирования определить собственную частоту колебаний и предупредить возникновение такого опасного явления, как резонанс. The paper substantiates the need for the use of shock absorbers and the replacement of the traditional elastomeric rubber material with a more advanced material - polyurethane. The aim of the work is an experimental study of the deformability of a polyurethane vibration-isolating array of a shock absorber and obtaining a calculated dependence for determining the natural frequency of oscillations of the aggregate-shock absorber system. The paper presents a detailed analysis of the dependence of the vibration isolation coefficient on the ratio of the frequencies of forced and free vibrations. It is noted that the effectiveness of vibration isolation is higher, the greater the ratio of the frequencies of forced and natural vibrations. Taking into account the fact that the frequency of forced vibrations is a given value, to increase the efficiency of vibration isolation, it is necessary to reduce the frequency of natural vibrations of the shock absorber due to the use of new vibration insulation materials. The work describes the loading device for studying the deformability of the vibration-isolating array of the KAS series shock absorber (welded ship shock absorber). An empirical dependence of the tightening coefficient is obtained depending on the shape coefficient of the vibration-isolating array of the shock absorber. The paper presents a calculated dependence on determining the frequency of natural oscillations of the shock absorber depending on the magnitude of the static deformation.