Вимірювальна техніка та метрологія. – 2015. – Випуск 76

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https://ena.lpnu.ua/handle/ntb/32930

Міжвідомчий науково-технічний збірник.

Вимірювальна техніка та метрологія : міжвідомчий науково-технічний збірник / Міністерство освіти і науки України ; відповідальний редактор Б. І. Стадник. – Львів : Видавництво Львівської політехніки, 2015. – Випуск 76. – 165 с. : іл.

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Томографічний метод вимірювання просторового розподілу температури за результатами вимірювань опору лінійних резистивних перетворювачів
(Видавництво Львівської політехніки, 2015) Дорожовець, Михайло; Бурдега, Мар’яна
Проаналізовано можливості реконструкції температурного поля на поверхні стінки томографічним методом за результатами вимірювання опорів лінійних резистивних перетворювачів температури. Опрацьовано модель апроксимації просторового розподілу питомого опору залежно від температури алгебраїчними двовимірними многочленами порядку 4 і 5. Сформовані матриці коефіцієнтів лінійних систем рівнянь, що описують шуканий просторовий розподіл питомого опору чутливих елементів від результатів вимірювань опорів чутливих елементів вздовж лінії їх розміщення на об’єкті дослідження. Моделюванням досліджено якість відтворення просторового розподілу температури томографічним методом з використанням мідних чутливих елементів. Встановлено, що за кількості вимірювань 54 та 96, а також за порядків многочлена 4 і 5 під час відтворення просторового розподілу температури у вигляді косинусної та гауссівської двовимірних моделей середньоквадратична зведена похибка становить від 0.65% до 1.55% , а максимальна зведена похибка відтворення – 1.25–9.35 %. Проанализировано возможности реконструкции температурного поля на поверхности стенки томографическим методом по результатам измерения сопротивлений линейных резистивных преобразователей температуры. Обработано модель аппроксимации пространственного распределения удельного сопротивления в зависимости от температуры алгебраическими двумерными многочленами порядка 4 и 5. Сформированы матрицы коэффициентов линейных систем уравнений, описывающих искомое пространственное распределение удельного сопротивления чувствительных элементов вдоль линии их размещения на обьекте исследования. Путем моделирования исследовано качество воспроизведения пространственного распределения температуры томографическим методом с использованием медных чувствительных элементов. Установлено, что при количестве измерений чувствительных элементов 54 и 96, а также при порядке многочлена 4 и 5 во время воспроизведения пространственного распределения температуры в виде косинусной и гауссовской моделей среднеквадратичная приведенная погрешность составляет от 0.65% до 1.55%, а максимальная приведенная погрешность воспроизведения от 1.25% до 9.35%. In the article the review of measurement problems related to spatial temperature distribution at various industrial facility is carried out. In particular for furnace, rubbish burning stove and walls of building structures. For these measurements acoustic and optical tomography are often used. In particular for spatial temperature distribution at furnace and rubbish burning stove acoustic tomography are used. To measuring the spatial temperature distribution of liquid medium ultrasound tomography is used. The disadvantage of the acoustic tomography is that the trajectory of acoustic waves greatly depended on the temperature distribution of an object. In the case of using screening, these methods aren’t used. In this article, the possibilities of reconstruction of temperature field on the surface of the wall using tomography method based on results of measurement of the resistance of linear resistive temperature sensors are analyzed. One of the possible ways of placing of the sensitive elements on the rectangular surface is reviewed (Fig. 1). Fig. 2 shows the generalized line along which the resistance of sensing element can be calculated. The resistance of linear resistive temperature sensors depending on resistivity are presented by equation (3). The resistance of linear resistive temperature sensors along line l j except vertical lines are presented can be calculate by equation (5), and resistance for vertical lines can be calculated by equation (6). The approximation of the spatial distribution of resistivity of sensitive elements two-dimensional function is present by equation (7). Coefficients’ matrices of systems of linear equations that describe desired spatial distribution of sensitive elements resistance from the results of resistance measurements of sensitive elements along the line of their placement on the subject of research were formed (equation 10). Coefficients’ vector of the basic functions were calculated using the method of least squares (equation 12). Approximated spatial temperature distribution can be calculated on the basis of approximation model of the spatial distribution of resistivity (equations 16 and 17). In the article proposed method is investigated for sensitive elements with the following parameters: resistivity ρ0 = 0.01724 μΩ m, temperature coefficient of resistance α = 4.3∙10-3 1/ºС, diameter of sensitive element d = 0.2 mm is simulated. The wall size of 6×6 m×m is investigation. Three approximation models of the temperature distribution in the form of two-dimensional cosine, Gaussian and asymmetrical functions with initial temperature Θ0 =100 ºС and maximal change temperature Θm = 75 ºС are used. For these temperature distributions and set parameters of sensitive elements the measured resistances sensitive elements (equation 21) are calculated. Using simulated results (equation (12) and (7)) the spatial distributions of resistivity are reconstructed. Also the spatial temperature distribution using simulated results is reconstructed (equation (17)) and presented in Fig. 4. The maximum modulo and root mean square characteristics errors of reconstructed temperature are calculated (equation (22), (23)) and presented in table 2. Found, that for 54 and 96 measurement results and for algebraic polynomials 4 and 5 order root mean square error of reconstruction of temperature field varies from 0.65% to 1.55% and maximum modulo error of reconstruction of temperature field varies from 1.25% to 9.35%. In conclusion, the reconstructed image of temperature depends on the number of linear resistive sensitive elements and also of order of polynomial approximation functions.
Про використання сейсмічних хвиль Релея в охоронних системах
(Видавництво Львівської політехніки, 2015) Рак, Володимир
Запропоновано використання сейсмічних хвиль Релея у охоронних системах сигналізації, які, крім ідентифікації порушення охоронного режиму, дадуть змогу визначати координати цього порушення. Проведено оцінку зони чутливості таких систем та визначено напрями подальших експериментальних досліджень з метою встановлення доцільності їх практичної реалізації. Предложено использование сейсмических волн Рэлея в охранных системах сигнализации, которые, помимо идентификации нарушения охранного режима, смогут определять координаты этого нарушения. Проведена оценка зоны чувствительности таких систем и определены направления дальнейших экспериментальных исследований с целью установления целесообразности их практической реализации. There are four types of seismic waves: primary waves , secondary waves , wave Rayleigh and Love waves. The first two types are called depth waves, because these waves penetrate into the depths of the earth. Rayleigh waves and Love waves called surface waves. They can to propagate on the surface. Given the characteristics of propagation of these waves can be concluded that even at low energies excitation source, Rayleigh waves can propagate at a much greater distance than depth waves, so it would be advisable to use them in security systems. Knowing the velocity of the waves, which is measured the sensors, the ratio of amplitudes and time delays with which they come, we can determine the coordinates of the source of vibration. The output voltage of existing sensors (seismometers) is a function of frequency seismic waves and their amplitudes. This may be the cause of the error. Autor is suggested another principle of the sensor, output signal of which is a function only of the amplitude. Is posted conversion function of sensors and dependence on the sensitivity threshold. If we know threshold of the sensitivity of the sensors, with certain assumptions, we can estimated distance from which capacitive seismometer feels seismic waves excitedWalking man at different values of the coefficient of energy absorption of seismic waves geological environment. For seismic exploration seismic surface waves are interference. Most likely, thismay explain the lack of information about the amount of energy that falls on the formation of surface waves and the dependence of this quantity on the power source. Zone of sensitivity may be limited to so-called microseisms arising from soil vibrations caused by fluctuations of the trees, transport, and industry. To limit the impact of microseisms be appropriate to apply filters. Therefore, before decision about the possibility of practical implementation of such systems, data relating to the area of sensitivity of seismometers need additional experimental verification in the field where necessary to experimentally explore: how much energy of the source belongs Rayleigh waves and Love waves ; energy distribution between surface waves; by the ratio of amplitudes determine the absorption coefficient of surface waves for areas where the security system will be used.
Аналіз шкал вимірювань
(Видавництво Львівської політехніки, 2015) Мотало, Василь
Розглянуто й проаналізовані основні питання теорії та принципи систематизації типів шкал вимірювань. Розглянуто види властивостей емпіричних об’єктів та особливості їх прояву і відповідні їм шкали вимірювань. Вибір і використання тієї чи іншої шкали і, відповідно, методики вимірювання залежить від виду вимірюваної величини та способу отримання вимірювальної інформації, тобто способу порівняння розмірів величин. Рассмотрены и проанализированы основные вопросы теории и принципы систематизации типов шкал измерений. Рассмотрены виды свойств эмпирических объектов, особенности их проявления и соответствующие им шкалы измерений. Выбор и использование той или иной шкалы и, соответственно, методики измерения зависят от вида измеряемой величины и от способа получения измерительной информации, т. е. способа сравнения размеров величин. The basic principles of systematization of measurement scales types are describes and analyses in this article. Properties types of the empirical objects and corresponding measurement scales are considered. According to VIM3 (“International vocabulary of metrology: Basic and general concepts and associated terms”), measurement scale (quantity-value scale) is an ordered set of quantity values of quantities of a given kind of quantity used in ranking, according to magnitude, quantities of that kind, for example, Celsius temperature scale, time scale, Rockwell C hardness scale etc. According to the metric determination, depending on the type of the investigated empirical object, in particular, of its properties, and therefore the type of measured value, measurement scales are divided into the following types: nonmetric scales: nominal scales and ordinal scales; metric scales: intervals scales, ratios scales and absolute scales. Metric scales – these are scales, which have the units of measurement (for eg., meter, ampere, m/s). Non-metric scales – these are scales, which do not have units of measurement. According to the form of empirical data obtaining, measurement scales are divided into verbal, numerical and graphic. According to the number of the displayed properties of empirical objects, measurement scales are divided into onedimensional and multidimensional. Nominal scales are formed in the case when a certain property of empirical objects is evident only in respect of equivalence. The main informative parameter of such objects is their quantity (number), which is determined by counting. This feature can be displayed by any number or other mark that does not contain any information about the value size, which is inherent in this property. Nominal scales or scales of names are used in the measurement of objective evidences such as odor, color, blood groups, nationality, marital status, age, gender, work experience, qualifications, telephone numbers, passports, bar codes of products, etc. Ordinal scales are formed in the case when a certain property of empirical objects is shown in relation of equivalence and order (of level). Located according to ascending or descending order, namely, according to the rank, the size of the measured values constitute ordinal scale or rank scale. The ordinal scale or rank scale is expressed in the form of an ordered sequence of points, marked with letters, numbers or symbols that meet certain values size Qі, і=1,2,3,…,п: Q1
Метрологія, кваліметрія та кваліметричні вимірювання: теорія і практика
(Видавництво Львівської політехніки, 2015) Мотало, Василь; Мотало, Андрій; Стадник, Богдан
Розглянуто й проаналізовані основні проблеми розвитку кваліметрії. Обґрунтовано використання в теорії та практиці кваліметрії концептуального поняття “кваліметричні вимірювання” як одного із видів вимірювань, що дозволяє поєднати методологію кваліметрії та метрології, істотно розширити можливості кваліметрії щодо достовірності й точності отриманих оцінок якості продукції. Розглянуто і проаналізовано основні завдання кваліметрії з оцінювання якості вуглеводневих газів. Рассмотрены и проанализированы основные проблемы развития квалиметрии. Обосновано использование в теории и практике квалиметрии концептуального понятия “квалиметрические измерения” как одного из видов измерений, что позволяет совместить методологию квалиметрии и метрологии и существенно расширить возможности квалиметрии в достоверности иточности полученных оценок качества продукции. Рассмотрены и проанализированы основные задачи квалиметрии в области оценивания качества углеводородных газов. In the article, the main issues of interrelation between qualimetry and metrology reviewed and analyzed. Qualimetry is a branch of science where research subject is product quality quantitative assessment and as an each new science it has some theoretical and methodological problems. Solving these problems, according to the authors, is possible only in a complex combination of quality control methodology and metrology. Metrology, the science of measurement and its application, has the strong scientific, practical and legal tools, which allows research in any field of knowledge. Analysis of the ways of solving these problems is the subject of this study. The authors propose to use the concept of “qualimetrical measurements” as one of the types of measurements in the theory and practice of quality control. That allows combine the methodology of qualimetry and metrology and significantly extend qualimetry opportunities in the reliability and accuracy of the product quality estimates. Qualimetrical measurements, by the authors definition, is indirect measurements of product quality level, the meaning of which can be obtained by the way of measurement results processing of its characteristics according to multidimensional scaling methodology. Product quality level is a relative characteristic of product quality grounding on the comparison of values of products quality assessed indexes and basic values of corresponding indexes. Generally, qualimetrical measurements as any other one consists of two principal stages: • carrying out the measuring experiment during which different characteristics (mechanical, dimensional, electric, magnetic, thermic and chemical composition etc.) of studied products are measured; • measuring experiment results processing during which the studied products quality Q is defined. This is the qualimetrical measurements results. Therefore, the mentioned above approach of qualimetrical measurements essence and purpose enables to treat them as one of the indirect measurements types and to use the main principles of measuring theory for their analysis. The procedure of qualimetrical measurements for measuring of product quality level is developed and its practical implementation described in this article and such tasks of research to achieve the work goal solved: • a synthesis of the product quality measure; • developing of the procedure of qualimetrical measurements; • a synthesis of the one-dimensional qualimetrical scale of product quality level; • a practical implementation of the qualimetrical measurements methodology on the example of the determining the quality level of natural gas as an energy source. The basis of any measurement is the comparison ofmeasured value and measure which reproduce and (or) keeps one ormore known values of a given quantity. Qualimetrical measurements specificity is absence of specific physical (material) quality measures of some products. Product quality virtual measure used formethodological providing of qualimetricalmeasurements procedure realization and their accuracy and quality assessment. Virtualmeasure is the theoretical analog of corresponding physical (material)measure of studied product and it’s the reflection of real physical (material) measure of current product quality is expressed by mathematical and programmeans. In this case, the product quality virtualmeasure is a weighted basic profile of product qualityPK,bz , formed from single relative weighted basic quality indexes Kbz,i , і = 1,2,…,п, where n – number of product quality indexes, equal to the number of properties of the investigated product. To measure the quality level of the investigated product Q, namely for full implementation of qualimetric measurements procedures, it is necessary to compare the weighted estimated profile of product quality PK,oz , formed from single relative weighted estimated quality indexes Koz,i , with weighted basic profile PK ,bz , namely with virtual quality measure. To compare profiles of quality PK,oz and PK,bz is used the methodology ofmultidimensional scaling – one of the sections of mathematical statistics, the subject of research of which is data processing on pairwise similarities, connections and relationship between objects that are analyzed in order to present these objects in the form of points of some multidimensional space. In the case of statistic independent (non-correlated) single relative quality indexes for comparision profiles of quality PK,oz and PK,bz it should be used weighed Euclidean individual differences model. In the case of correlation between the single quality indexes to determine product quality level it should be used three-model multidimensional scalingmodel. In both cases it should be defined the absolute difference or deviation function DП between profiles of quality PK,oz and PK,bz . On the basis of obtained deviations DП the scale of product quality level Q determination can be build, and as result bigger numerical quality Q level value will correspond for higher product quality: Q = 1 –DП or Q = (1 –DП)×100%. Thus, based on the methodology of qualimetrical measurements, developed in the article, the complex evaluation of the Natural Gas quality as an energy source was realized, in which were taking into account a ratio of themost important gas characteristics, such as caloric content, humidity, density, composition, availability and quantity of non-flammable and harmful components.
Оцінювання стандартної непевності типу “В” на основі складових адитивної та мультиплікативної похибок
(Видавництво Львівської політехніки, 2015) Васілевський, Олександр
Запропоновано спосіб перерахунку адитивної та мультиплікативної складових похибок, аналітичні вирази яких отримуються розкладанням відповідного рівняння перетворення у ряд Тейлора, в стандартну непевність типу В. Цей спосіб апробовано під час оцінювання статичних характеристик засобу вимірювання кутової швидкості. Він дає змогу представляти характеристики точності засобів вимірювань відповідно до вимог міжнародних стандартів з оцінювання якості вимірювань. Предложен способ пересчета аддитивной и мультипликативной составляющих погрешностей, аналитические выражения которых получают путем разложения соответствующего уравнения преобразования в ряд Тейлора, в стандартную неопределенность типа В. Этот способ апробирован при оценке статических характеристик средства измерения угловой скорости. Он позволяет представлять характеристики точности средств измерений в соответствии с требованиями международных стандартов по оценке качества измерений. A method for conversion additive and multiplicative constituents of errors, analytical expressions are obtained by decomposition of the corresponding transformation equations in Taylor series in a standard uncertainty of type B. Decomposition of transformation equations used means of measuring in the Taylor series allows to obtain analytical expressions of basic static characteristics of the means of measuring on the basis of which it is possible to explore the characteristics of changes in the sensitivity of means of measuring, the nominal conversion function, influencing coefficients, additive and multiplicative errors in a deviation of influencing parameters on their nominal values. This method has been tested in the evaluation of static characteristics of measuring angular velocity. It allows you to represent the characteristics of precision of means of measurements in accordance with the requirements of international standards to assess the quality of measurements. These mathematical expressions allow investigation of basic metrological characteristics of a measuring angular velocity, and the causes and conditions that lead to increased measurement errors in the angular velocity of electric motors to be identified. To represent standard uncertainty of type B, which is caused by the presence of additive and multiplicative errors in the measurement means, mathematical expressions are proposed that allow recalculation of these errors to standard uncertainty. The mathematical expressions were tested using the example of the recalculation of additive and multiplicative errors of the measurement means of the torque in the standard uncertainty of type B. The resulting mathematical tools and characteristics of change of the basic static metrological measuring means for angular velocity give us the opportunity to identify the causes of increase in error in the measurement of angular velocity in electric motors. This enables us to explore how to diminish or eliminate them, and also to synthesise measuring means angular velocity with standardised metrological characteristics. To convert received instrumental error components measuring angular velocity in a standard uncertainty of type B and presentation characteristics of precision measuring instruments in accordance with the requirements of international standards to assess the quality of measurements suggested model equations given in the article. On the basis of the proposed model equations executed counts additive and multiplicative error components measuring the angular speed of the combined standard uncertainty of type B, which is caused by the presence of the instrumental components of errors in deviation vlyayuschih magnitude of its nominal value. The studies found that the type B standard uncertainty is 3.38 rad/s in the range of conversion from 0 to 100 rad/s rejecting influence quantity β from its nominal value of 0.01 radians.
Дослідження акустичних методів вимірювання температури в рідинах
(Видавництво Львівської політехніки, 2015) Петровська, Ірина; Івах, Роман; Сопрунюк, Анастасія
Досліджено можливість вимірювань температури у воді із застосуванням двох акустичних методів: ехо-пульс і часоімпульсного. Для проведення вимірювань використано потоковий канал, через який пропускали воду, температура якої змінювалась і вимірювалась з використанням ультразвукових сенсорів. Встановлено залежність температури води від параметрів ультразвукового сигналу. Проведені дослідження показали, як саме змінюється швидкість звуку у воді зі зміною температури у ній. Наведено графік отриманого сигналу зі зміною температури від 10 °С до 60 °С. Исследована возможность измерений температуры в воде с использованием двух акустических методов: эхо-пульс и время-импульсного. Для проведения измерений использовано потоковый канал, через который пропускали воду, температура которой изменялась и измерялась с использованием ультразвуковых сенсоров. Выявлено зависимость между амплитудой и временем ультразвукового сигнала. Проведенные испытания показали, как именно изменяется скорость звука в воде с изменением температуры в ней. Представлено график полученного сигнала с изменением температуры от 10 °С до 60 °С. In this work the subject of the research is the average temperature of liquids by using two acoustic methods: echo-pulse method and time-pulse method. For conducting the measurements the flow channel is used, through which water was passed, the temperature of which has changed and which must be measured. For the temperature measurements ultrasonic sensors are used, which are fixed on both sides of the current channel. The calculation of the special design of the mounting is made and the ultrasonic sensors are chosen. The size estimation of the glass coupling rod is made, based on the average temperature of the glass cylinder, thermal resistance, cylindrical glass square.The block diagram is presented for measuring the passage time of the ultrasonic signal in the measuring channel, according to which the transmitter and receiver are in direct contact with the pipe. For better contact ultrasonic gel was used. In addition, the oscilloscope to measure audio signals and device for generating acoustic pulses and their measurement using echo-pulse method are used. The results of studies using the echo pulse and the time-pulse methods are presented. The first measurement of the echo-pulse method was performed using the ultrasonic sensor on the pipe when the flow of water is active and the temperature of the water in the thermostat is fixed in the range from +10 C to 60 °C. The second dimension using this method is conducted when the flow of water is inactive in conditions of the same temperatures. The obtained results of measurements using the time-pulse method with an oscilloscope and an exemplary device when the temperature changes from 20 °C to 60 °C in increment of 10 are presented. The graphs of the dependencies obtained for all investigated temperatures are depicted. It is revealed that the current times of the sound pulses with increasing temperature are short. The chart is moved to the left. The signal on the oscilloscope screen in conditions of 60 °C is received. The first channel shows the audio signal acquiring with an exemplary device. The second channel shows the measuring signal. The next measurement is made with a glass cylinder, which is placed between the pipe and the ultrasonic sensor. The results of measurements using a glass cylinder in the temperature range from 20 °C to 60 °C are presented. The results of the carried out measurements show how the amplitude of the ultrasonic signals with a signal change is modified. Having this change it is possible to find the temperature which is needed to be determined. By using oscilloscope the dependence between amplitude and time of the ultrasonic signal is revealed. Studies have shown in which way the sound speed in water is changing with its internal temperature change.
Інтелектуальний кутовий сенсор для антенних систем та його метрологічний аналіз
(Видавництво Львівської політехніки, 2015) Паламар, Михайло; Чайковський, Андрій; Лупенко, Анатолій
Запропонована електронно-оптична схема, конструкція та алгоритм функціонування оптоелектронного сенсора абсолютних кутових положень з функціями виявлення та компенсації низки похибок, що виникають у механічних вузлах обертового механізму, за допомогою опрацювання інформації мікроконвертором у самому сенсорі. Виконано метрологічний аналіз сенсора й оцінку джерел похибок за результатами моделювання та експериментальних досліджень. Інтелектуальний сенсор орієнтований на використання у системах керування наведенням антенних комплексів космічного зв’язку. Предложена электронно-оптическая схема, конструкция и алгоритм функционирования оптоэлектронного сенсора абсолютных угловых положений с функциями обнаружения и компенсации ряда погрешностей, возникающих в механических узлах вращающегося механизма, путем непосредственной обработки информации микроконвертором в самом сенсоре. Проведен метрологический анализ сенсора и оценка источников погрешностей по результатам моделирования и экспериментальных исследований. Сенсор ориентирован на использование в системах управления наведением антенных комплексов космической связи. The design and electron-optical scheme of intelligent opto-electronic sensor of absolute angular position are proposed. The sensor is completed by microconverter for data processing to implement the detection and compensation a number of errors that caused by mechanical nodes of rotating mechanisms. The principle of the operation of proposed angle sensor are based on themethod of determining the absolute angular position using a code disk with one track. Pseudorandom code sequence of track is composed of different widths sectors. The code reading and processing is realised by means of two single-line photo-matrices located at the ends of the chord of the disk. The code sequence is constructed so that any fragment of sectorswhen projected on photo-matrix is unique and occurs only once in passing the code sequence on the disk. To accurately determine the angular position the algorithm of the sub-pixel processing image is used. It allows determine the distance to the edges of the sectorswith resolution ability higher than half of the pixel width, that is equal of 2 micrometer. The resolution ability in the angle determination by sensor is increased to 16 bits. Due to the sensor design features, such as usage of two opto-electronic channels and software implementation of algorithms for processing information from photo-lines, errors caused by mechanical nodes of sensor via disk offset and eccentricity are minimized. Measuring at the proposed scheme also avoids the influence of random displacement sensor axis due to backlash in the bearings. The resolution ability of the designed sensor is 20 arcseconds. Based on simulation results and experimental studies metrological analysis of sensor and evaluation of error sources are given. Intelligent sensor in design and functionality was designing for the usage in control systems in particular in the pointing and tracking the antenna of the space communication systems with a narrow directional diagram.
Моделювання та якість моніторингу діагностичних систем
(Видавництво Львівської політехніки, 2015) Чабан, Олеся; Юзевич, Лариса
Розроблено рекомендації щодо поліпшення якості математичних моделей моніторингу складних об’єктів техніки та медицини з низьким рівнем динаміки процесів, що характеризуються особливостями раннього виявлення кризових (передаварійних) ситуацій. Разработаны рекомендации относительно повышения качества математических моделей мониторинга сложных объектов техники и медицины с низким уровнем динамики процессов, которые характеризуются особенностями раннего выявления кризисных (предаварийных) ситуаций. The example of improvement of the mathematical model of monitoring of difficult objects of technique and medicine with the low level of dynamics of processes is examined. The article of researches is normative documents, which should be expediented to specify and perfect on the basis of thein formation, got as a result of analysis of results, mathematical models of monitoring of difficult objects of technique, medicine got with a help with the low level of dynamics of processes. An aim of the put article is an evaluation of quality of theim proved mathematical model of monitoring of difficult objects of technique, medicine with the low level of dynamics of processes. As an example, the diagnostic system of the corrosive monitoring of pipelines (SCMP) is examined, the methodologies described and regulated by a state standard are fixed in basis of functioning of that. Facilities of SCMP are diagnose the stress corrosive spalling of pipelines, that is initiated and develops as defects on the external surface of pipe at using of isolating coverage and cathode defence for simultaneous influence of the mechanical loading and corrosive-active environment. A corrosive environment is designed by an aquasystem with the different value of pH-value. The criterion of damage of sheeting the methods of measuring of protective and polarization potentials is a jection of electric potential, that is compared to the value, set corresponding normative document. It is suggested to use methodology of control of constituents for slushing coverage on the stage of making of steel pipes with coverage on the size of regional corner of moistening. Coverages can be metallic, dielectric. In particular, the three-stratified polyethylene coverage is used in the last time. On the size of regional corner of moistening it is possible to estimate adhesion of coverage, in particular, work of adhesion and energy of adhesive bonds. The criterion of adhesion strength for coverage (metallic or dielectric), that is expressed through the critical values of power descriptions of interface layer on the border of metal of pipe with coverage is introduced. The methods of scientific researches are constantly developed and improved. Therefore in course of time standards need additions, id est bringing of new more actual information. Touches such type of addition integral criterion of evaluation of biocorrosive aggressiveness of soils, that takes into account exceptelectro-resistance also a quantity most corrosive dangerous groups of microorganisms and elements of chemical composition of soils. Possible penetration of oxygen, water and other substances is through sheeting. As a result there is a hasp of passive tape with formation of local cells of corrosion – pitting. Pitting of transformed in microcrack, and on the finishing stage one of microcracks initiates distribution of main crack. Procedure of calculation of durability and longevity of pipeline is offered at presence of defects as a cavity there is pitting in the top of that. Methodologies of calculation of durability of steel pipes at presence of defects are complemented by the criteria of durability, that in the models of SCMP was not examined before. The first criteria represents connection of threshold value of coefficient of intensity of tensions of К1SCC with work off lowage in a calculation on unit of the accrued surface at distribution of crack of PPL and overstrain of anodic reaction z of corrosive dissolution. The parameter of PPL is included in the known formula (criterion of durability) of Griffits-Orovan, that it is also suggested to be used. The criterion of Griffits-Orovan binds the limit of fluidity (to durability) of metal to length of crack, by the Young’s module and by the Poisson’s ratio of material. The system of mathematical correlations of SCMP is suggested to complement correlation for the closeness of current of ia in the top of pitting, that is expressed through a corner in the top of pitting, conductivity of electrolyte, dependency upon resistance change of potential between anodic and cathode parts. This correlation is set forth as a criterion of corrosive firmness of pitting. The model of SCMP is complemented by criterion correlation for determination of speed of remaining corrosion of metal (id est closeness of Ik of corrosive current) in the defect of isolating coverage, polarization potential and potential of corrosion of metal of pipeline are included in that. The new entered criteria of durability and corrosive firmness complement, specify and perfect SCMP and can be used for control of corrosive process and development of recommendations of slushing defence. With their help optimization of terms of defence of elements of constructions of metallic underground pipelines can be conducted. The compatible use of the new entered criteria allows in detailen ough from positions of electrochemistry, physics of superficial processes and mechanics of destruction to study the mechanisms of distribution of corrosive cracks in main pipelines that are in aggressive environments. Monitoring quality is characterized by quality of measuring and recreation of information, in particular: by exactness, comparativeness, authenticity, operationability, stability of estimations of parameters, that is included in the new entered criteria. Recommendations in relation to upgrading of mathematical models of monitoring of difficult objects of technique and medicine with the low level of dynamics of processes touch protective potentials, them uncertainty and gradients. An algorithm that is base on the use of the new entered criterion correlations and allows to optimize oscillation of protective and polarization potentials in time is offered in the system of the corrosive monitoring of underground pipelines, that it is necessary for the correct evaluation of corrosive activity of soil and speed of remaining corrosion of metal of pipeline. Corresponding results give an opportunity to forecast the change of the corrosive state of metal of pipeline in course of time and to expect the resource of capacity of local area and all pipeline on the whole. The indicated innovations will help to perfect normative documents, in particular, standards that touch anticorrosion defence.
Розроблення та аналіз варіантів апаратної реалізації портативних частотних аналізаторів імпедансу
(Видавництво Львівської політехніки, 2015) Стадник, Богдан; Хома, Володимир; Хома, Юрій
Описано та проаналізовано три варіанти побудови портативних частотних аналізаторів імпедансу на сучасній елементній базі та розглянуто можливості їх використання в поєднанні із ПК, а саме: на базі спеціалізованих мікросхем AD5933/AD5934, сигнального мікроконтролера STM32F4, програмованої логічної матриці сім’ї Cyclone. Також наведено алгоритми функціонування ЧАІ, з описом процедур калібрування та визначення параметрів АВП, коригування та опрацювання результатів вимірювання. Описаны и проанализированы три варианта построения портативных частотных анализаторов импеданса на современной элементной базе и рассмотрены возможности их использования в сочетании с ПК, а именно: на базе специализированных микросхем AD5933 / AD5934, сигнального микроконтроллера STM32F4, программируемой логической матрицы семейства Cyclone. Также приведены алгоритмы функционирования ЧАИ, включающие описание процедур калибровки и определения параметров АИП, корректировки и обработки результатов измерения. Impedance spectroscopy is widely used to study biological, physical and chemical objects, for example in biomedical measurements, in study of the materials properties, particularly on micro- and nanoscale, for corrosion monitoring and diagnostics, for control of batteries, fuel cells. Often research is carried out on a objects under non-laboratory conditions. A good example of such research is the use of impedance spectroscopy for testing of corrosion-resistant coatings on various steel structures such as bridges, pipelines and other. This leads to the need for cheap, small portable measuring devices – impedance analyzers. A novel concept for design of portable impedance analyzers have been developed in the article. Themain idea is based on minimization of the analog part ofmeasurement channel, aswell as on the replacement of a number of functions to a personal computer. Three variants of design of portable impedance analyzers are described and analyzed in the article. The first option involves the use of single-chip converter AD5933, combined with universal processor Atmega16U2 and external operational amplifier. The hardware implementation is quite simple, but the main disadvantage is limited frequency band (maximum frequency converter AD5933 is 100 kHz). Also this approach has no possibility for tuning and optimization of measuring channel parameters. The second implementation of portable impedance analyzers is based on the STM32F4 digital signal controller with built-in DACs and ADCs, which makes it an extremely attractive in terms of flexibility and simplicity in the design. However, the drawback of this implementation includes limited frequency band (100 kHz). The third option involves the implementation of digital part of the impedance analyzer (CPU, DDS and DSP blocks) on FPGA in combination with external DAC and ADC. This method is the most flexible in terms of configuration, as the digital part enables optimization of measurement channel parameters and DAC and ADC specifications can be chosen according to current application needs. The main disadvantage of this approach is relatively high price and power consumption.
Ризики харчового ланцюга біологічно активних добавок (на прикладі вітамінних додатків, що містять аскорбінову кислоту)
(Видавництво Львівської політехніки, 2015) Бойко, Тарас; Христина, Дух
Проаналізовано структуру вимог до біологічно активних добавок відповідно до міжнародних нормативних документів; виконано їх порівняльний аналіз з національними вимогами. Показано, що вдосконалення чинного нормативного забезпечення щодо вимог безпеки біологічно активних добавок повинно ґрунтуватись на вимогах HACCP. Запропоновано визначати ризики як комбінацію втрат, оцінених через “втрату якості” схильних до небезпеки об’єктів, та вірогідності виникнення небезпеки, отриманої експертним оцінюванням ймовірності її виникнення. Зроблено висновок, що, ідентифікуючи на основі отриманих оцінок у продукті небезпечні чинники з найвищим ризиком, можна достовірно визначати критичні точки контролю і здійснювати відповідні коригувальні дії, а отже, підвищити ефективність системи НАССР. Проанализирована структура требований к биологически активным добавкам согласно международным нормативным документам; выполнен их сравнительный анализ с национальными требованиями. Показано, что совершенствование существующего нормативного обеспечения требований безопасности биологически активных добавок должно базироваться на требованиях HACCP. Предложено определять риски как комбинацию потерь, оцененных как “потеря качества” предрасположенных к опасности объектов, и достоверность возникновения опасности как экспертная оценка вероятности ее возникновения. Сделан вывод, что, идентифицируя на основе полученных оценок в продукте опасные факторы с наивысшим риском, можно достоверно определять критические точки контроля и соответствующие корректирующие действия, а следовательно, повысить эффективность системы НАССР. Biologically active additives (Dietary Supplements) - a special product that is used to correct the structure of human nutrition and to prevent certain diseases. One of the most common supplements are vitamin supplements. Their use is recommended in situation when the number of vitamin in the body is insufficient. That is why vitamin additives should be considered as an important products that require a responsible attitude to the evaluation of their quality characteristics. First of all it concerns safety hazard - risks. Organization that specifically created for standardization requirements for food products is the Codex Alimentarius Commission. The Commission acknowledges dietary supplements that contain vitamins and minerals as food, it is obvious that they should apply the requirements of ISO 22000: 2005. According to the standard, the concept of food safety means that food will not cause harm to the consumer when it is prepared and / or consumed in food according to its intended use. Food is characterized by the food chain, which is the sequence of stages and operations since primary production to consumption. Food Safety should be monitored at all stages of the food chain. Basic concept by which determined food safety is a food safety hazard. It is a biological, chemical or physical agent in food or a condition of product, potentially causing adverse health effects. Risk as combinations of likelihood of damage and the effects of the damage. Risk is a quantitative assessment of food safety hazard. In particular, in the context of food safety risk is determined as a function the likelihood of adverse health effects (eg, the probability of disease) and materiality consequences of such exposure (eg, disease severity). In turn, severity, such as can be determined indirectly through duration of lasting disability of the employee in the event of defeat this dangerous factor and the probability determined by the characteristics of the distribution of probability derived from statistical processing of disability cases for the period. For mentioned the size of the losses (primarily as a component of risk) assessment of the proposed so-called "quality loss". The concept requires explanation. Let facility in certain circumstances, can become a source of potential danger. If its quality as a set of properties that are responsible for security, goes to the “one”, the danger of such an object goes to zero and vice versa. Quality, as we know, can be estimated using the methodology of qualimetry using indicators of quality, which in our case will be safety indicators. The contribution of each indicator in the overall assessment of the factors traditionally expressed by weight coefficients. The risk can be determinated as a danger of loss quality, means deviation qualimetric assessment from “one”. Probability danger (the second component of risk) should be determined based on the prerequisite programme food safety, which is the basic conditions and activities necessary to maintain the desired environmental hygiene throughout the food chain. Separate prerequisite programme is specific in each field, depending on the segment of the food chain, which operates the organization and type of organization. For example, it may be: Good Agricultural Practices (GAP), Good Veterinary Practice (GVP), Good Manufacturing Practice (GMP), Good Hygiene Practices (GHP), Good Practice Primary Production (GPP), Good Distribution practice (GDP). The specified for certain products are operational prerequisite programme, containing identification and analysis of hazards that are significant to control their introduction to the food product. Identification, analysis and setting of values of probability in expert way involving, for example, the method of direct evaluation. As food safety depends on the presence of these dangerous factors at the time of consumption, and the hazards can appear on any stage of the food chain, for adequate control in each link of the food chain must have the specific values of all possible risks. Accordingly, the requirements ofHACCP should form the operational prerequisite programme identification and analysis of dangerous factors, which are essential to control the probability of introduction to food and to provide control measures and monitoring. Required to identify hazards in the product at high risk (assessment). And for each establish critical control points, critical limits, monitoring procedures and corrective actions.
Дослідження електрофізичних параметрів олійних рідин в електромагнітному полі
(Видавництво Львівської політехніки, 2015) Міхалєва, Марина; Чурко, Галина
Розглянуто основні проблеми якості фармацевтичних олій різних рослин. Визначено електрофізичні параметри олій розмарину, бергамоту, евкаліпту та мигдального горіха у електромагнітному полі різної частоти. Наведено фрагмент атласу залежностей складу ефірних олій від електричних параметрів для експресного контролю якості. Рассмотрены основные проблемы качества фармацевтических масел различных растений. Определены электрофизические параметры масел розмарина, бергамота, эвкалипта и миндального ореха в электромагнитном поле различной частоты. Приведен фрагмент атласа зависимостей состава эфирных масел от электрических параметров для экспрессного контроля качества. Reviewed the main methods of using essential oils in aromatherapy, medicine, food and pharmaceutical industries. Formulated the concept of quality essential oils that covers their effectiveness and harmlessness. Found factors that affect the main warehouse oils and factors, that depends on the content of individual substances in essential oils. Set forth basic indicators of the quality of essential oils and the conditions of getting from plants. Described the such problem of the quality of essential oils as falsification. Reviewed examples of substances that are used for adulteration of essential oils. Specified on the similarity of natural and adulterated oils on organoleptic characteristics and the difference in quality. Specified the necessity of using only natural oils for treatment. Refuted the information about the existence of essential oils from fruits and described the harm from such counterfeit products. Defined the crucial issue of essential oils - naturalness. Describes how to get the natural oils from plants and are prohibited from use in oils components. Analyzed the duration and complexity of laboratory methods for quality control of essential oils and the lack of control of naturalness in Ukraine. Asked to identify the essential oils in a magnetic field of different frequencies on the electrophysical parameters. Analyzed effectiveness studies of the composition of the modern devices. Tasked to develop a method for fast control quality of essential oils on the basis of the dependency of the electrical parameter from the composition of the oils. Determined the dependence of the dielectric conductivity of essential oils on their individual chemical composition and its informativeness about the composition of the essential oils and their physico-chemical properties. Tasked to investigate the electrical properties of the samples of the finished product and on the basis of the obtained results to create an atlas of the dependency of the active component of the conductivity from their individual chemical composition. On the basis of the tasks conducted a number of studies electrophysical parameters of essential oils. To ensure accuracy, measurements used samples from 14 industrial units for each of the samples of the finished product. Studies performed using capacitive primary converter. Eliminated spurious effect on the readings. Defined electrophysical parameters oils of rosemary, bergamot, eucalyptus and almond in the electromagnetic field of varying frequency. According results the research created atlas dependency electrophysical parameters from the composition of essential oils. Shows a fragment of the atlas. Conclusions are made about the dependence of the components of the complex conductivity of oils in the electromagnetic field of different frequencies from the chemical nature of the oil-bearing plants and selectivity of the created method. As well as improvement the rapid of methods of identification of natural oils and their quality control. Is proposed to use the received frequency dependence of electrical parameters of essential oils to improve (automation) certification studies and control in distribution networks.
Методика визначення тепловтрат будинку за результатами тепловізійного дослідження
(Видавництво Львівської політехніки, 2015) Дзіковська, Юлія; Гоц, Наталія
Проаналізовано методики розрахунку тепловтрат будинку, виявлено їх особливості та недоліки. Розроблено методику проведення розрахунку теплових втрат поверхні огороджувальних конструкцій будинку за результатами тепловізійного дослідження залежно від опору теплопередачі та градієнта температури базової й дефектної ділянок. Проанализированы действующие методики расчета теплопотерь здания, выявлены их особенности и недостатки. Разработана методика проведения расчета тепловых потерь поверхности ограждающих конструкций здания по результатам тепловизионного исследования в зависимости от сопротивления теплопередаче и градиента температуры базового и дефектного участков. The application of infrared thermography as a method of estimation of heat losses of building structures is becoming more popular within the resolve the issues of power resources economy, determination of energy efficiency and increasing of buildings thermal protection. It should be remembered that the output result of buildings thermal imaging research is thermal temperature distribution of the investigated surface on the thermogram. Other information, including the value of the heat losses from the surface of the building envelopes, is gotten by analytical method, which involves the construction of certain algorithm. As the results of the review of recent researches and publications we can conclude that the usage of thermal imaging research is mainly limited by finding places with thermal field deviations from basic values and recognition that they are defective. Quantitative processing of heat losses that are related with it is missing out. Therefore, in the article the brief overview of current methods of heat losses calculation is provided, their features and weaknesses are identified and the method of calculating of heat losses of the building envelopes surface, that is based on the results of thermal imaging research depending on resistance of the thermal transmittance and temperature gradient of the basic and defect areas, is developed. Methods, that are provided by acting normative documents of Ukraine, optimally satisfy the conditions of complex heat exchange because they take into account within the usage of the resulted and subjunctive thermal transmittance coefficients all three types of heat exchange, namely conductivity (through heat conductivity of material), convection (through heat transmission) and radiation (through heat emission). Thus, if we can find all unknown values in the methods formulas such algorithms give us possibility to determine the basic value of building envelope heat losses for a specific rooms and building in general. The negative aspect of the usage of these algorithms is proximity of calculation (for example, as a result of surface heterogeneity of the building envelopes) and the reference to table values of most variables, which can significantly vary from the actual values as a result of the building exploitation, the influence of climatic conditions, the repairs etc. In addition, the awkwardness of the calculations and the need of the simultaneous availability of a large number of normative documents increase the time that is required to their realization, respectively the cost of such work, as well as the growth of subjective component of calculations error. Therefore we propose to add to the normative methods method of heat losses calculation of building that is based on the results of thermal imaging research. The first algorithm involves the determining of the value of resulted resistance of thermal transmittance of defective area using its basic value from formula of the surface temperature distribution of the building envelopes. The second algorithm allows to determining the growth of heat losses compared to its value of the basic area using the identified quantity of the relative resistance of thermal transmittance. The disadvantage of these two algorithms is that to calculate the heat losses we must have information about the structure of the building envelope (its basic area) to determine the resulted resistance of the thermal transmittance of the construction. The effectiveness of these two algorithms is justified in the case of simulation of potential thermal characteristics of the building on the results of the implementation of the recommendations for building thermomodernization, when the resulted resistance of building thermal transmittance is predetermined. The third algorithm allows to consider that in practice in real conditions operators have to work with the buildings of long time exploitation, for which its thermal characteristics are changed due to influence of various factors or data of these characteristics are absent. In this case, in calculating of heat losses we have to be limited only by the data of thermogram and the results of accounting of the research conditions to determine the resulted resistances of basic and defective areas. For this we provide the creation of the system of two equations based on the formula of surface temperature distribution of the building envelopes. Creation of such system is possible in three variants. Selection of each of them depends on the thermograms information of building and the possibility of second thermal imaging research, because each of the options makes its own budget of uncertainty in the resulting value of the resulted resistance of thermal transmittance. The following algorithm for determination of the heat losses suggests their definition only in the radiative component of heat flux. It allows to limit the minimum number of input variables, whose values are provided exclusively by thermal imager and technical documentation on it. It should be remembered that such losses are always smaller than losses that are determined by the total heat flux. On the basis of the calculation of building heat losses increase their monetary evaluation is conducted. It helps to estimate the recoupment of work to eliminate the sources of such heat losses.
Дослідження методів знешумлення інтерферограми білого світла
(Видавництво Львівської політехніки, 2015) Хома, Анна
Проаналізовано джерела спотворень інтерферограми білого світла. Обґрунтовано методику та досліджено ефективність знешумлення синтезованого сигналу інтерферограми з використанням цифрових фільтрів та вейвлет-перетворення. Результати апробовано на реальній інтерферометричній картині. Проанализированы источники искажений интерферограмы белого света. Обоснована методика и исследована эффективность фильтрации синтезированного сигнала интерферограмы с использованием цифровых фильтров и вейвлет-преобразования. Результаты апробированы на реальной интерферометрической картине. White light interferometry (WLI) is a non-contact measurement technique which is commonly used in determining the mechanical quantities such as geometric dimensions, position, and surface topography of the object. The main areas of use of the white light interferometers are micro- and nanotechnology, biomechanics, polymer chemistry, semiconductor equipment, and others. The measuring channel of optical interferometer includes the optical part and the computer unit. The accuracy of surface reconstruction depends on the quality of interferogram registration (optical part) and metrological properties of the reconstruction algorithm (computer unit). In practice interferogram registration is accompanied by different distortions, including optical nonlinearities and noise. Reduce of the distortions destabilizing effect can be achieved by processing the obtained interferogram in a computing unit by special algorithms. The aim of the work is analysis of methods for white light interferogram denoising. The article analyzes the distortion sources of white light interferogram and the ways of their processing. The technique of researchis based on analyzing the effectiveness of denoising the synthesized white light interferogram with signal-tonoise ratio of 30 dB. Quantitative parameter for evaluating the filtering effectiveness is signal-to-noise ratio. Firstly the researches were conducted on one-dimensional data (for the central line of interferometric pattern). This article examines the possibility of WLI denoising with digital filters (frequency domain) and wavelet transform (time-frequency domain). When using digital filters, the non-recursive filters were selected, as they are characterized by a linear phase response that will keep the shape signal. Filtering of interferogram signal using nonrecursive filter has not produced satisfactory results, as in one case with noise suppression the part of useful signalis damaged, and the signal-to-noise ratio was 15 dB. By increasing the cutoff frequency of the filter, signal shape does not undergo distortion, but there are some artifacts, especially in its central part. The reason is that the signal lies partly in the frequency dominated, where the noise predominates. The signal-to-noise ratio was 35 dB. Wavelet transform allows to decompose a signal to approximating and detailing components, with higher levels of detailing component responsible for scheduling and signal noise can be set to zero without signal distortion. Application of wavelet transformation made it possible to achieve better denoising results compared to digital filters with signal-tonoise ratio about 50 dB. Taking into account these results, the wavelet transform method is adapted to the two-dimensional data (interferometric pattern). Compared to the one-dimensional data the denoising is slightly lower, as evidenced by the signal-to-noise ratios about 40 dB. This is due to the fact that the interferogram signal intensity decreases as the distance from its center. The effectiveness of the denoising method based on wavelet transform was investigated on a real white light interferogram obtained for a spherical surface. Defects observed in the interferometric pattern after denoising are caused by optical distortions.
Дослідження термометричного матеріалу Hf Ni1-x COx Sn
(Видавництво Львівської політехніки, 2015) Крайовський, Володимир; Ромака, Володимир; Стадник, Юрій; Ромака, Любов
Досліджено енергетичні, кінетичні та магнітні характеристики термометричного матеріалу HfNi1-xCoxSn у діапазонах: T = 80 ¸ 400 K, Co » 9,5×1019 NA см-3 ( x = 0,005 )÷ 5,7 ×1021 см-3 ( x = 0,30 ) і напруженості магнітного поля H £10 кГс. Показано, що характеристики HfNi1-xCoxSn чутливі до зміни температури і він може бути основою для виготовлення чутливих елементів термоперетворювачів. Исследованы энергетические, кинетические и магнитные характеристики термометрического материала HfNi1-xCoxSn в диапазонах: T = 80 ¸ 400 K, Co » 9,5×1019 NA см-3 ( x = 0,005 )÷ 5,7 ×1021 см-3 ( x = 0,30 ) и напряженности магнитного поля H £10 кГс. Показано,что характеристики HfNi1-xCoxSn чувствительны к изменениям температуры и он может быть основой для изготовления чувствительных элементов термопреобразователей. The electron energy state, magnetic and transport characteristics of thermometric materials HfNi1-xCoxSn were investigated in the T = 80 ¸ 400 K temperature range and at charge carriers concentration from Co » 9,5×1019 NA см-3 ( x = 0,005 )÷ 5,7 ×1021 см-3 ( x = 0,30 ) and H £ 10 kGs. The material HfNi1-xCoxSn is sensitive to the temperature change and could be used as the basis for the sensitive thermoelectric devices. We investigated the crystal structure, electron density of states (DOS) and the kinetic and energy characteristics of n-HfNiSn heavily doped with the Co impurity. Samples were synthesized at the laboratory of the Institute of Physical Chemistry, Vienna University. The HfNi1-xCoxSn crystal-lattice periods were determined by X_ray analysis with the use of the Fullprof software. We employed a data array obtained by the powder method using a Guinier-Huber image plate system. The chemical and phase compositions of the samples were determined using a Ziess Supra 55VP scanning electron microscope and an EMPA energy dispersive X-ray analyzer. The electronic structure was calculated by the Korringa–Kohn–Rostoker (KKR) technique in the coherent potential approximation (CPA) and local density approximation (LDA), as well as the full-potential linearized plane wave (FP-LAPW) method within density functional theory (DFT). In the calculations, we used experimental values of the lattice constant on a k grid 10 × 10 × 10 in size and the Moruzzi–Janak–Williams exchange correlation potential parametrization. The width of the contoured energy window was 16 eV. The number of energy values for DOS calculations was 1000. To predict the behavior of the Fermi level, band gap, and electrokinetic characteristics of n-HfNiSn doped with Co atoms, the electron density distribution (DoS) was calculated. The calculated results pretending to be adequate to experimental studies should account for complete information on the semiconductor’s crystalline structure. To obtain more accurate results, we calculated the DoS for almost all possible cases of the mutual substitution of atoms at sites of the HfNiSn unit cell. Shows the result most consistent with experimental data. It was found that the disordered structure (Hf1-xNix)NiSn, x = 0.01, of the HfNiSn compound is most probable. We note that the same result was obtained from structural studies of HfNiSn. The partial (to 1 at%) substitution of Hf atoms with Ni atoms generates donor-type structural defects in the crystal, and the Fermi level is in the band gap which becomes narrower. It was also found that the minimum in the dependence of variations in the DoS at the Fermi level (DoSF(x)) for the disordered structure (Hf1-xNix)NiSn of the HfNiSn compound corresponds to the (Hf0.99Ni0.01)NiSn composition. In this semiconductor model, the Fermi level is in the band gap which is εg ≈ 282 meV. The same question arises when analyzing the behavior of the dependences (x) and (x) in HfNi1-xCoxSn. For example, the (x) variation in the concentration range 0.05 ≤ x ≤ 0.20 shows that the modulation amplitude of the continuous energy bands of HfNi1-xCoxSn HDCSs increases. Indeed, the activation energies (x) increase from (x = 0.05) = 38.3 meV to (x) (x = 0.20) = 59.2 meV. As we already noted, such behavior is possible only when compensating electrons appear in the p-type semiconductor due to the ionization of donors whose appearance was not initially assumed. In HfNi1-xCoxSn samples, x > 0.20, the decrease in (x) indicates a decrease in the modulation amplitude of the continuous energy bands, which is possible only when the degree of compensation of HfNi1-xCoxSn decreases due to a decrease or termination of the generation of donor-type structural defects. Thus, the initial assumption that n-HfNiSn doping with Co atoms by substituting Ni atoms is accompanied by the generation of only acceptor-type structural defects in the crystal does not allow consistent explanation of the behavior of the energy characteristics of HfNi1-xCoxSn HDCSs. The variations in the activation energy of hopping conduction (x) and the modulation amplitude of the continuous energy bands (x) unambiguously prove the existence of a donor source in HfNi1-xCoxSn. Further, we will identify the possible mechanism for the appearance of donors. The series of studies on the crystalline structure, energy spectrum, and electrokinetic parameters of the n_HfNiSn intermetallic semiconductor heavily doped with the Co impurity allowed determination of the variation in the degree of compensation of the semiconductor due to the generation of both structural defects of acceptor nature during the substitution of Ni atoms with Co atoms and defects of donor nature during the partial substitution of Ni sites with Sn atoms. The n_HfNiSn crystalline structure is disordered, and the Hf site can be occupied by Ni to ~1 at%, which generates structural defects of donor nature in the semiconductor and explains the mechanism of its “a priori doping with donors”. The mechanism of the degree of compensation of the semiconductor as the result of the crystal structure transformation during doping, leading to the generation of structural defects of the acceptor and donor nature was established. The results of the electronic structure calculation are in agreement with experimental data and the HfNi1-xCoxSn semiconductor is a promising thermoelectric material. The results are discussed in the framework of the heavily doped and compensated semiconductor model by Shklovsky–Efros.
Уточнений розрахунок на міцність захисних оболонок термоперетворювачів за умов експлуатації
(Видавництво Львівської політехніки, 2015) Гук, Олександр; Дробенко, Богдан
Запропоновано наближений метод порядкових статистик для опрацювання випадкових спостережень за апріорі невідомого розподілу ймовірності генеральної сукупності. Використання наближеного методу не потребує складних розрахунків інтегралів і коваріаційна матриця визначається за допомогою простих арифметичних операції. Подано результати наближеного методу і продемонстровано його ефективність. Разработана численная методика исследования процессов деформирования защитных оболочек термопреобразователей в условиях сложного силового и температурного нагружения на основе трехмерных соотношений термомеханики. Выполнены исследования защитных оболочек различных типоразмеров на статическую и циклическую прочность в условиях их гидравлических испытаний эксплуатации и установлены коэффициенты их запаса. Accurate evaluation of possible safe operation of thermowells essentially depends on the accuracy of the maximum stresses in them during operation. These stresses are generally determined from simple engineering formulas for bulk of canonical shape, mostly cylindrical shells or beams for the relevant boundary conditions. Thus the general solution is obtained step by step. First the tangential stresses are obtained from relations for cylinder subjected to external pressure. Next, axial stress is estimated and the stability of the thermowell is researched from the equations for cylindrical rod. The additional bending stresses that occur during flow of working environment (fluid or steam) around the thermowell, determined on the basis of simple ratios of strength ofmaterials, considering cylindrical beam set perpendicular to the direction of the flow; the beam is clamped at one end and is free at the other one. Then the resulting maximum stress, obtained as a sum of these categories of stresses, is compared with the stress, admissible for material. The possible error of this approach is compensated by introducing a safety factor. However, in general, the thermowells are the spatial solids with complex geometric shapes, and their stress-strength state is spatially non-uniform during operation. So determination of stresses in them using simple engineering formulas, obtained for simplest elements of mechanical systems, can lead to significant errors. This article deals with the problem of estimation of resource and operational reliability of thermowells. In the proposed approach the thermowells are considered as a three-dimensional solids, and the computer simulation of deformation processes in thermowells under operational conditions is executed on the basis of refined spatial three-dimensional models of stress calculation in solids under complex force and temperature loading. Numerical analysis of thermowell stress-strength state is performed using the finite element method. It allows to describe adequately complex geometric shape and three dimensional stress-strength state of thermowell during its operation, and to identify the most loaded areas of thermowell. This approach also allows us to estimate the limits of applicability of simple engeneer formulas, which are used as a rule in the practice of thermowells strength estimation. The strength calculations of the thermowells of different sizes made from a steel 08H18N10T and types during hydraulic test (at pressure 36 MPa) and operation conditions (at pressure 25 MPa, temperature 365 °C, for different velocities of water and water vapor – from 0 to 120 m/s) are fulfilled, and their safety factors are determined on the basis of the proposed approach. In particular, the safety factor for the most loaded thermowell is about 1,4 (compared maximum of stress intensity in the thermowell with a yield stress of the steel at operating temperature) and 3 (in comparison with the tensile strength). Whereas, steel 08H18N10T can significantly strengthen during the plastic deformation, the actual safety factors are larger than calculated ones. The research of convergence obtained numerical solutions is fulfilled. The results of comparative analysis of the solutions based on the proposed approach and standardized methods using simple engineering relationships are shown. In particular, the maximal stress intensities inmost loaded thermowell during operational conditions obtained from these two approaches differ in 1.5 times. So the use of simple engineering formulas in this case leads to higher values ofmaximal stresses. The analysis of a cyclic fatigue calculation shows that the possibility of destruction of thermowells caused by low cycle fatigue during operation is unlikely (we get over 33,000 acceptable cycles “initial state – operational mode – initial state” or “loading – unloading” for the most loaded thermowell during operation). The proposed approach can be used for determining the geometry of thermowell at the fixed conditions of operation and for determining the parameters of operation modes (for example, the pressure or velocity of working environment, etc.) for specific parameters of thermowell fixed geometry.
Дослідження термометричного матеріалу Zr1-xCeNiSn
(Видавництво Львівської політехніки, 2015) Крайовський, Володимир; Ромака, Володимир; Стадник, Юрій; Ромака, Любов; Андрій, Горинь
Досліджено енергетичні, кінетичні та магнітні характеристики термометричного матеріалу Zr1-xCexNiSn у діапазонах: T = 80÷400 K, x=0.01÷0.10 і напруженості магнітного поля H £10 кГс. Показано, що характеристики Zr1-xCexNiSn чутливі до зміни температури і він може бути основою для виготовлення чутливих елементів термоперетворювачів. Исследованы энергетические, кинетические и магнитные характеристики термометрического материала Zr1-xCexNiSn в диапазонах: T = 80÷400 K, x=0.01÷0.10 и напряженности магнитного поля H £10 кГс. Показано,что характеристики Zr1-xCexNiSn чувствительны к изменениям температуры и он может быть основой для изготовления чувствительных элементов термопреобразователей. The electron energy state, magnetic and transport characteristics of of thermometric materials Zr1-xCexNiSn were investigated in the T = 80 ¸ 400 K temperature range and at charge carriers concentration from x=0.01÷0.10 and H £ 10 kGs. The material Zr1-xCexNiSn is sensitive to the temperature change and could be used as the basis for the sensitive thermoelectric devices. We investigated the crystal structure, electron density of states (DOS) and the kinetic and energy characteristics of n-ZrNiSn heavily doped with the Ce impurity. Samples were synthesized at the laboratory of the Institute of Physical Chemistry, Vienna University. The Zr1-xCexNiSn crystal-lattice periods were determined by X-ray analysis with the use of the Full-prof software. We employed a data array obtained by the powder method using a Guinier-Huber image plate system. The chemical and phase compositions of the samples were determined using a Ziess Supra 55VP scanning electron microscope and an EMPA energy dispersive X-ray analyzer. The electronic structure was calculated by the Korringa–Kohn–Rostoker (KKR) technique in the coherent potential approximation (CPA) and local density approximation (LDA), as well as the full-potential linearized plane wave (FP-LAPW) method within density functional theory (DFT). In the calculations, we used experimental values of the lattice constant on a k grid 10 × 10 × 10 in size and the Moruzzi–Janak–Williams exchange-correlation potential parametrization. The width of the contoured energy window was 16 eV. The number of energy values for DOS calculations was 1000. To predict the behavior of the Fermi level, band gap, and electrokinetic characteristics of n-ZrNiSn doped with Ce atoms, the electron density distribution (DoS) was calculated. The calculated results pretending to be adequate to experimental studies should account for complete information on the semiconductor’s crystalline structure. To obtain more accurate results, we calculated the DoS for almost all possible cases of the mutual substitution of atoms at sites of the ZrNiSn unit cell. Shows the result most consistent with experimental data. It was found that the disordered structure (Zr1-xNix)NiSn, x = 0.01, of the ZrNiSn compound is most probable. We note that the same result was obtained from structural studies of ZrNiSn. The partial (to 1 at %) substitution of Zr atoms with Ni atoms generates donor-type structural defects in the crystal, and the Fermi level is in the band gap which becomes narrower. It was also found that the minimum in the dependence of variations in the DoS at the Fermi level (DoSF(x)) for the disordered structure (Zr1-xNix)NiSn of the ZrNiSn compound corresponds to the (Zr0.99Ni0.01)NiSn composition. In this semiconductor model, the Fermi level is in the band gap which is εg ≈ 282 meV. The same question arises when analyzing the behavior of the dependences (x) and (x) in Zr1-xCexNiSn. For example, the (x) variation in the concentration range 0.02 ≤ x ≤ 0.10 shows that the modulation amplitude of the continuous energy bands of Zr1-xCexNiSn HDCSs increases. Indeed, the activation energies (x) increase from (x = 0.05) = 38.3 meV to (x)(x = 0.07) = 59.2 meV. As we already noted, such behavior is possible only when compensating electrons appear in the p-type semiconductor due to the ionization of donors whose appearance was not initially assumed. In Zr1-xCexNiSn samples, x > 0.05, the decrease in (x) indicates a decrease in the modulation amplitude of the continuous energy bands, which is possible only when the degree of compensation of Zr1-xCexNiSn decreases due to a decrease or termination of the generation of donor-type structural defects. Thus, the initial assumption that n-ZrNiSn doping with Ce atoms by substituting Zr atoms is accompanied by the generation of only donor-type structural defects in the crystal does not allow consistent explanation of the behavior of the energy characteristics of Zr1-xCexNiSn HDCS. The variations in the activation energy of hopping conduction (x) and the modulation amplitude of the continuous energy bands (x) unambiguously prove the existence of a donor source in HfNi1-xCеxSn. Further, we will identify the possible mechanism for the appearance of donors. The series of studies on the crystalline structure, energy spectrum, and electro-kinetic parameters of the n-ZrNiSn intermetallic semiconductor heavily doped with the Ce impurity allowed determination of the variation in the degree of compensation of the semiconductor due to the generation of both structural defects of donor nature during the substitution of Zr atomswith Ce atoms and defects of donor nature during the partial substitution of Ni sites with Sn atoms. The n-ZrNiSn crystalline structure is disordered, and the Zr site can be occupied by Ni to ~1 at%, which generates structural defects of donor nature in the semiconductor and explains the mechanism of its “a priori doping with donors”. The mechanism of the degree of compensation of the semiconductor as the result of the crystal structure transformation during doping, leading to the generation of structural defects of donor nature was established. The results of the electronic structure calculation are in agreement with experimental data and the Zr1-xCexNiSn semiconductor is a promising thermoelectric material. The results are discussed in the framework of the heavily doped and compensated semiconductor model by Shklovsky–Efros.
Пристрій для дистанційного вимірювання параметрів поверхонь рефлекторів антен
(Видавництво Львівської політехніки, 2015) Михайло, Паламар; Ігор, Зелінський; Мирослава, Яворська
Запропоновано схему приладу та оптичної системи для дистанційного вимірювання координат поверхні рефлектора за принципом суміщення світлових марок від монохромних джгутів. Наведено формули для обчислення координат точок сканованої поверхні за значеннями параметрів приладу. Подано оцінки точності значень вимірюваних величин. Предложена схема прибора и оптической системы для дистанционного измерения координат поверхности рефлектора путем совмещения световых марок от монохромных пучков. Приведены формулы для вычисления координат точек сканированной поверхности, исходя из значений параметров прибора. Даны оценки точности значений измеряемых величин. The scheme of the device and the optical system for reflector surfacemeasurement is proposed. The device implements a triangulation principle in the determination of distance to a remote point. The optical system forms two coaxial light beams of equal intensity. One beam directed at a right angle to the base. At the initial stage of themeasurements second beamis direct in a manner to provide beams tracks juxtaposition on the beginning of the Cartesian coordinate system tied to the scanned surface. The displacement of the light beams tracks on a surface implemented by means of turning of the base around the point of its fixing, and the basis length changing in a neighborhood of its initial length value. The values of the point coordinates are determined through the base displacement and the angle of the base rotation, provided the juxtaposition of both beams. It should be noted that beamtrack on the surface is observed as a diffraction pattern on the ring diaphragmin the far zone with a clear expressed main peak whose diameter at the working distance (about 2–3 m) is approximately 0.2 mm. Visual observation of beams tracks juxtaposition is conduct by means of photographic system, which contains long-focal objective, a set of filters for laser light selection and digital camera.Monitoring is conduct on the computer screen at 50-foldmagnifications ofmain peaks. It allowed us to make a conclusion aboutmain peaks juxtaposition with accuracy ~ 0.1mm. The formulas to calculate the coordinates of the point on the surface scanned through base rotation angle and base length displacement are given. An analysis of the performance parameters ranges of device depending on the size of the surface scanned ismade. Also the sensitivity coefficients ofmeasured values to device parameters are assessed. It is established that the instrumental errors of the device in the range of angle changing within (–5◦, 5◦) and the range of base displacement changing within (–12 cm, 12 cm) do not exceed fractions of tenths of amillimeter. To light beams displacement vertically there is a possibility in the device to rotate the optical system in the plane perpendicular to the base. A map of the surface deviation fromthe shape is formed with regard to assessments of instrumental errors in a defined range of the device settings change.
Багаторівнева метрологічна перевірка кіберфізичних систем
(Видавництво Львівської політехніки, 2015) Олеськів, Ольга
Проаналізовано особливості функціонування кіберфізичних систем та їх компонентів. Розглянуто можливості під’єднання первинних перетворювачів до кіберфізичних систем. Запропоновано варіанти структурної реалізації кіберфізичних систем. Запропоновано багаторівневу метрологічну перевірку кіберфізичних систем. Запропоновано алгоритми перевірки програмного забезпечення кіберфізичних систем на системному, підсистемному рівнях та на рівні інтелектуальних первинних перетворювачів. Проанализированы особенности функционирования киберфизических систем и их компонентов. Рассмотрены возможности подключения первичных преобразователей к киберфизическим системам. Предложены варианты структурной реализации киберфизических систем. Предложено многоуровневую метрологическую проверку киберфизических систем. Предложены алгоритмы проверки программного обеспечения киберфизических систем на системном и подсистемном уровнях, а также на уровне интеллектуальных первичных преобразователей. This article presents the features of functioning the cyber-physical systems and their components. The cyber-physical systems are complex systems which components may be located at great distance from one another. The cyber-physical systems perform processing of information and functions of monitoring and control equipment. Cyber-physical systems infrastructure mainly consists of subsystems, which electronic components are implemented through the embedded system control and get information about the environment through sensors and measuring device and can influence it through actuators. The analysis opportunity of sensors possible accession to embedded system control is examined. The classification by the sensors output signal type is considered. On the basis of the sensors classification concluded that the cyber-physical systems is most expedient to use intelligent sensors. Intelligent sensors have a number of properties that significantly distinguish them from other types of sensors. Intelligent sensors can automatically choose measuring range, carry out algorithmic correction of the measurement results, operate in a dialogue with the central control system, take decisions, transfer measurement results in digital form, as well as alarms and others. Intelligent sensors can conduct self-tuning, selftesting and self-examination. Intelligent sensors performing necessary conversion of measurement data andmathematical processing of measurement results. Therefore, the use of intelligent sensors enables to release embedded system control from storage and processing of a large number of intermediate data. Given the above information allows considering the optimal use of intelligent sensors in cyber-physical systems. A structural implementation of cyber-physical systems in two ways is proposed: 1) all subsystems of cyber-physical systems is equal, able to form task and together with other components to participate in solving them, carry out a self-testing, self-examination, etc.; 2) in the cyber-physical systems are basic subsystem that controls and verification all other subsystems, primary means, and sensors performs. According to the results of the analysis of the cyber-physical system and those components characteristics, amultilevel remote metrological verification of cyber-physical systems is proposed.With the proposed algorithm the cyber-physical system components can be verified at the request of any component, subsystem or system as a whole. Also a person can initiate ametrological testing process, if there is suspicion of incorrect operation or its time for cyber-physical system routine verification. The algorithms of metrological verification the software of cyber-physical systems at the system, subsystem and sensors levels are proposed. Ideally, the human factor is excluded from the verification process. The person will be involved in the verification of the cyber-physical systems software only when are errors with which the system can not cope on their own.
Зміст до збірника «Вимірювальна техніка та метрологія» Випуск 76
(Видавництво Львівської політехніки, 2015)
Титульний аркуш до збірника «Вимірювальна техніка та метрологія» Випуск 76
(Видавництво Львівської політехніки, 2015)

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