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The development of forage crop varieties that adapt to changing environmental conditions is an effective strategy to mitigate the impact of climate change with minimal losses. Temperature influences both the timing and rate of seed germination, which in turn ensures uniform seedling emergence, compatibility of red clover with other crops, and the ability to exploit optimal sowing conditions. This study aimed to determine the temperature and time required to achieve maximum germination, as well as the range within which germination occurred, for four red clover samples of varying biological status (cultivars, wild and local populations). Germination capacity and energy of red clover samples were assessed according to the standards outlined in DSTU 4138 2002 and DSTU 2949-94 at temperatures ranging from 3°C to 33°C in 10°C increments. It was established that the optimal temperature for the germination of red clover seeds among the four studied samples ranges from 13°C to 33°C on filter paper and from 13°C to 23°C on sand. The research identified the Vytis cultivar as outperforming other samples in all measured parameters when germinated on filter paper, while the Truskavchanka cultivar demonstrated superior traits when germinated on sand. The best germination rates were observed in the wild population at a temperature of 13°C. These findings explain the uneven emergence of red clover samples of varying biological status in collection and breeding nurseries, as observed under field conditions. The results of this study can inform the development of sowing technologies for red clover under various temperature regimes. [ABSTRACT FROM AUTHOR]

In this research, we have studied a self-heating effect in hybrid 2D-3D heterostructure diode, considering planar GaN-based structure of 1280 nm with n-type channel and donor concentration of 6·1017 cm-3. Two type c-plane substrate-based sapphire and GaN are considered in order to investigate heating effects in diode channel. Monolayer hexagonal boron nitride (h-BN) on the top of canal is considered as an element for thermal control of the diode. The model of a heating based on macroscopic thermal parameters of materials is used. The simulation of diode operation was carried out using the Ensemble Monte Carlo Technique selfconsistently with numerical solving of system of heat equations by full multigrid (FMG) method. Transport properties of diode is considered under condition of high electric fields and impact ionization. Characteristics of the diode with both h-BN monolayer and without one were obtained at DC applied voltage. A temperature distribution in diode is obtained with account of thermal boundary resistance at each interface, considering voltage range of 0-20 V. In strong electric field in anode, the heating rises maximal temperature in channel diode up to over 600 K. The h-BN was found to affect the temperature magnitudes and their redistribution in diode channel. Temperature decrease can achieve 3 % and increase in case of high temperature region. Role h-BN monolayer as a factor avoiding formation of localized overheating of a device is demonstrated. It is shown that, h-BN monolayer is effective in diode using the substrate with low thermal conductivity and can be applied for semiconductor devices with length of several micrometers. [ABSTRACT FROM AUTHOR]

Surface corrosion and wear significantly limit the lifetimes of industrial components, resulting in high economic and safety costs. However, as surface-level phenomena, these degradation mechanisms can potentially be mitigated through surface modifications alone, without altering bulk properties. Recent advances in nanotechnology have made possible a range of nanostructured protective coatings for surfaces. By incorporating nanomaterials like ceramics and metals, these coatings provide enhanced resistance to chemical corrosion and physical wear. This review discusses the current state of research on nanostructured coatings for surface protection. It summarizes the synthesis techniques for producing nanostructured coatings such as solgel and electrochemical deposition methods. The corrosion and tribological behaviors of various coating materials like metal oxides and nitrides are compared. Composite polymer-metal coatings are highlighted for their superior crack resistance compared to traditional ceramic coatings. In addition, bio-inspired self-healing and lubricating coatings are described. Finally, current technical challenges and future research directions are outlined such as improving coating adhesion strength and scale-up for mass production and commercialization. [ABSTRACT FROM AUTHOR]

При получении гречневой крупы и гречневой муки используют гидротермическую обработку (ГТО). Для ГТО применяют влаготепловую обработку – пропаривание и сушку или увлажнение с отволаживанием. При увлажнении с отволаживанием полнее сохраняется белковый состав зерна, проще реализуется технологический процесс. Пропаривание позволяет обеспечить технологические свойства гречневого зерна – прочность и упругость ядра при шелушении. Различными режимами пропаривания регулируются и потребительские и нутрицевтические свойства будущего продукта – цветность, хранимость, усваиваемость и т.п. При пропаривании используют различные теплоносители – насыщенный или перегретый водяной пар, горячий воздух. Некондиционное гречневое сырье - сырое, сухое, перезимовавшее под снегом, также может быть переработано в кондиционный продукт модифицированными способами ГТО. Режимы обработки – длительность экспозиции и температуру - варьируются в зависимости от назначения конечной продукции – товарная крупа, мука. Гречневое зерно обладает нутрицевтическим потенциалом использования в качестве функционального продукта, обладая антиоксидантными свойствами, что может быть обеспечено специфическими режимами ГТО. В качестве технологического оборудования применяют емкостные периодические пропариватели, с греющей поверхностью и другие. Исследуется процесс и устройства непрерывного пропаривания. Обобщены возможности использования гречневой лузги, типичного отхода переработки зерна гречихи.

Метою дослідження було вивчення ефективності використання цифрової інфрачервоної термографії для ранньої діагностики та виявлення ділянок порушеної перфузії і некрозу тканин у пацієнтів із некротизуючим фасціїтом. Матеріали та методи. Робота базується на основі спостережень за 10 пацієнтами з підозрою на некротизуючий фасціїт упродовж 2022-2023 років. За допомогою портативного цифрового інфрачервоного тепловізора пацієнтам виконували термографію уражених ділянок із метою отримання теплових карт і термограм, які згодом аналізували на наявність аномальних теплових патернів. Результати термографії порівнювали з іншими ознаками некротизуючого фасціїту. Результати. У пацієнтів із некротизуючим фасціїтом виявлено теплову емісію шкіри у вигляді трьох концентричних зон із різною поверхневою температурою навколо основного вогнища інфекції. Центральна зона (N) мала знижену температуру, проміжна зона (F) - підвищену, а зовнішня зона (S) - температуру, що була близькою до нормальної для цієї ділянки тіла. Результати статистичного аналізу показали, що між зовнішньою та проміжною зонами не було суттєвої різниці в температурі. Однак були значні відмінності між зовнішньою і центральною зонами, а також між проміжною і центральною. Дослідження показало, що наявність зони «N» із різко зниженою тепловою емісією, оточеною зоною підвищеної теплової емісії «F» та різницею температур 5,72±0,23°С, є ознакою пізньої стадії некротизуючого фасціїту. Водночас на ранній стадії розвитку некротизуючого фасціїту зона «N» є відсутньою, хоча спостерігається виражена зона «F», що оточена зоною «S» із різницею температури приблизно 1,92±0,28°С. Висновки. Виразні теплові патерни, що простежуються в пацієнтів із некротизуючим фасціїтом, дають змогу підвищити точність діагностики та допомогти у своєчасному виконанні хірургічного втручання. Продовження вивчення та удосконалення медичної термографії допоможе надалі включати її у стандартну клінічну практику з метою поліпшення діагностично-лікувального процесу некротизуючого фасціїту. Дослідження виконано відповідно до принципів Гельсінської декларації. Протокол дослідження ухвалено локальним етичним комітетом зазначених у роботі установ. На участь у дослідженні отримано інформовану згоду пацієнтів. Автори заявляють про відсутність конфлікту інтересів.

Розглянуто основні підходи для забезпечення потрібної температури потоків речовин і матеріалів, що перебувають у технологічному й допоміжному обладнанні різних галузей економіки, зокрема хімічної, харчової, мікробіологічної, теплоенергетичної, металургійній, сільськогосподарської, медичної й будівельної. Робочі органи технологічного обладнання та певні конструктивні елементи допоміжного обладнання при цьому запропоновано виготовляти з магнітного матеріалу з температурою фазового переходу ІІ роду (точкою Кюрі), що відповідає температурі проходження технологічного або допоміжного процесу. Розглянуто технологічні процеси з використанням магнітотермічного ефекту та відповідні конструкції обладнання: теплообмінного, тепломасообмінного, механічного й гідромеханічного, обладнання для перероблення термопластів, а також інших пристроїв. Зазначений метод забезпечення потрібного теплового режиму доцільно застосовувати насамперед у великотоннажних виробництвах неперервної дії. Перевагою методу є стабільне проходження процесу у вузькому температурному діапазоні, що надзвичайно важливо під час оброблення термочутливої сировини й напівфабрикатів для забезпечення стабільних властивостей одержуваної продукції, а недоліком – труднощі під час пошуку наявних або створення нових феромагнітних матеріалів з потрібними термомагнітними властивостями для виготовлення відповідних конструктивних елементів технологічного й допоміжного обладнання.

Отримання круглих порожнистих напівфабрикатів гарячим зворотним видавлюванням із заготовок круглого і квадратного перерізу є першим переходом штампування при виготовленні порожнистих виробів спеціального призначення. Для таких виробів потрібно забезпечити певні механічні властивості по висоті стінки і в донній частині, які можна досягти за рахунок пропрацювання структури металу пластичною деформацією. Пропрацювання донної частини здійснюється при зворотному видавлюванні. Властивості по висоті стінки отримують на подальших переходах витягування з потоншенням напівфабрикату після видавлювання. Використання заготовок квадратного перерізу приводить до більш інтенсивного пропрацювання донної частини напівфабрикатів при зворотному видавлюванні. Однак в результаті видавлювання виникають чотири виступи на торці стінки напівфабрикату в місцях, які відповідають кутовим зонам заготовки. Наявність виступів приводить до необхідності застосування додаткової операції підрізання торцю стінки напівфабрикату перед витягуванням, а також до збільшення витрат металу. Тому актуальною задачею є дослідження способу усунення виступів у напівфабрикаті та додаткової операції підрізання торцю. Підвищення точності форми і розмірів порожнистих напівфабрикатів при гарячому зворотному видавлюванні із заготовок квадратного перерізу. Усунення виступів досягається за рахунок утворення фасок в кутових зонах заготовки квадратного перерізу шляхом попереднього осаджування перед видавлюванням. За допомогою методу скінченних елементів (МСЕ) проведено моделювання процесів гарячого осаджування кутових зон на вихідній заготовці квадратного перерізу та подальшого зворотного видавлювання з роздачою круглих порожнистих напівфабрикатів. Визначено розміри фасок на заготовці із маловуглецевої сталі, які забезпечили усунення виступів на торці стінки круглого напівфабрикату після видавлювання. Встановлено залежності зусиль осаджування та видавлювання від переміщення пуансонів. Виявлено питомі зусилля на деформуючому інструменті. Наведено розподіли напружень, деформацій та температури у здеформованому металі в кінці осаджування та видавлювання. Проведено оцінку пропрацювання структури металу гарячою пластичною деформацією. Розроблено конструкцію штампу для виконання осаджування і видавлювання. Встановлено геометрію заготовки квадратного перерізу з фасками у кутових зонах, яка забезпечує усунення виступів на торці стінки при гарячому зворотному видавлювання з роздачою круглих порожнистих напівфабрикатів.

The paper studies the gettering properties of nickel clusters in the silicon lattice. The gettering properties of nickel clusters were studied in various states, i.e., in original (reference) samples, as well as in samples with additionally doped interstitial and lattice site impurity atoms of sulfur and manganese. The electrophysical and photoelectric parameters were studied using modern instrumentation: INFRAM-I-type infrared microscope, IKS-21 and scanning electron microscope SEM (Oxford Instruments ZEISS EVOMA10), IKS-21. A new technology has also been proposed that makes it possible to getter harmful impurities; it is recommended for widespread use in the electronics industry and scientific research institutes for the production of materials with stable parameters and the development of fundamentally new devices. [ABSTRACT FROM AUTHOR]

This study investigates the fabrication and performance of SnO2 thin films for gas sensing applications, utilizing a deposition method at 2 bar pressure and 8 ml/min flow rate. A multilayer structure was developed, comprising 14 layers, each with a thickness of 250 nm, optimized for sensitivity and stability. The gas sensor, featuring a film heater and sensitive elements doped with a 1% silicon additive, demonstrated a wide operational temperature range (20-370 °C). Characterization of resistance changes revealed significant hysteresis before isothermal annealing, with resistance values stabilizing after prolonged exposure to 370 °C. Post-annealing, the sensor exhibited three orders of magnitude higher resistance, indicating improved stability and electronic transport properties. Doping with a 1N AgNO3 solution significantly enhanced sensitivity to ammonia, with a detection threshold of 500 ppm, while sensitivity to alcohol vapors decreased, indicating selectivity. Experimental results confirm that local doping and thermal treatment effectively enhance the metrological characteristics of SnO2-based sensors, making them suitable for detecting toxic gases. [ABSTRACT FROM AUTHOR]

In this paper, the effect of doping silicon with dysprosium (Dy) on its structural and optical characteristics is investigated. Silicon n-Si was doped with dysprosium by thermal diffusion at 1473 K for 50 h. Raman spectroscopy and X-ray diffraction analysis were used for the analysis. The Raman spectroscopy results showed a main peak at 523.93 cm-1, corresponding to n-Si optical phonons, with an increase in the intensity and full width at half maximum (FWHM) in n-Si samples, indicating an improvement in the crystallinity of the structure. A decrease in the intensity of the peaks at 127.16 cm-1 and 196.24 cm-1, associated with amorphous structures, confirms a decrease in defects. The detection of a new peak at 307.94 cm-1 indicates successful deposition of dysprosium as nanocrystallites associated with the 2TA phonon mode in the cubic phase of Dy2O3. X-ray diffraction analysis revealed characteristic structural lines indicating the (111) crystalline orientation and the presence of microdistortions in the lattice. Heat treatment and rapid cooling lead to a change in the intensity of structural lines, an increase in the second- and third-order lines, which indicates microstrains and a change in the size of subcrystallites. Doping of silicon with dysprosium improves the crystallinity of the structure, reduces the number of defects and forms polycrystalline layers on the surface consisting of SiO2 and Dy2O3 nanocrystals. [ABSTRACT FROM AUTHOR]

The results of the analysis of temperature monitoring data were obtained using the information and measuring system (IMS) “Finish” (1991 - 2015) and expert research system, new safe confinement (NSC) integrated control system in the main volume (MV) under the arched space, and the weather station in Chornobyl (1991 - 2023). After the NSC was installed in the design position, a slight increase in average annual MV NSC air temperature was observed before 2021. During the same period, the average annual temperature of concrete around the localization area of nuclearly hazardous clusters of fuel-containing materials (FCM NHC) in room 305/2 of the “Shelter” object increased by 1.3 - 1.4 times and had returned to 0.7 - 0.8 of the value of 1991. From 2021, no next increase in the mean annual temperature of concrete has been noticed. As of 2023, if compared to the monitoring period before Arch pushed into its design position, the calendar shift between the temperature of concrete and the surrounding environment enhanced to 1 month, according to both minimum and maximum average month values. [ABSTRACT FROM AUTHOR]

Cold spray is a solid-state deposition technology widely used in additive manufacturing. The particles temperature is mostly used to adjust the porosity of the coating. This article uses Pyhon script to model the multi-particle model; then the multi-particle model is nested in the CEL deposition model to simulate the actual cold spray multi-particle deposition process; The CEL method has the characteristics of high accuracy and robustness and was selected as the simulation method for the multi-particle deposition model. The porosity of the coating is expressed by studying the value of the EVF void area in the Euler domain. Multiple groups of samples were taken on the coating surface to calculate the porosity of each group, and the average value was finally taken as the porosity of the entire coating. Numerical results show that increasing the particle temperature can effectively reduce the porosity of the coating. The average porosity of the coating under the particles temperature conditions are 600 K: 5.08 %; 650 K: 4.02 %; 700 K: 3.58 %; deposition completed the inside of the coating appears to be compacted. The substrate temperature will affect the combination of the coating and the substrate. It is recommended that the temperature difference between the particles and the substrate should not be too large. The CEL method simulates the process of cold spray multi-particle deposition, which is an effective method to observe and predict the porosity of the coating, which is also unachievable by the SPH and ALE methods. [ABSTRACT FROM AUTHOR]

Stamping of round hollow semi-finished products by hot reverse extrusion from round and square workpieces is the first stamping step in the manufacture of hollow products for special purposes. These products require certain mechanical properties along the wall height and in the bottom part, which can be achieved by working out the metal structure by plastic deformation. The bottom part is worked out by reverse extrusion. The wall properties are obtained in the following stages of drawing the semi-finished product with thinning after extrusion. The use of square workpieces results in more intensive working out of the bottom of the semi-finished products during the reverse extrusion. However, as a result of extrusion, four protrusions appear at the end of the semi-finished product wall in places that match the corner areas of the workpiece. The presence of protrusions leads to the need for an additional operation of cutting the end of the semifinished product before extrusion, as well as to an increase in metal usage. Therefore, an urgent task is to study the method of eliminating protrusions in the semi-finished product and the additional cutting operation. To improve the accuracy of the shape and size of hollow semi-finished products during hot reverse extrusion from square workpieces. Elimination of protrusions is achieved by forming chamfers in the corner zones of the square workpiece by preliminary deposition before extrusion. The finite element method (FEM) was used to model the processes of hot deposition of corner zones on a square workpiece and subsequent reverse extrusion with the dispensing of round hollow semi-finished products. The dimensions of the chamfers on the high-carbon steel workpiece were determined, which ensured the elimination of protrusions at the end of the wall of the round semi-finished product after extrusion. The dependence of the deposition and extrusion forces on the punch movement was determined. The specific forces on the deforming tool were determined. The distributions of stresses, strains, and temperature in the deformed metal at the end of deposition and extrusion are presented. The working out of the metal structure by hot plastic deformation is evaluated. The design of a stamp for deposition and extrusion is developed. The geometry of a square workpiece with chamfers in the corner zones was determined, which ensures the elimination of protrusions at the wall end during hot reverse extrusion with the dispensing of round hollow semi-finished products. [ABSTRACT FROM AUTHOR]

Purpose. To study the course of heat phenomena in disc brakes using modern computing systems in order to determine and substantiate the operating parameters for the hoisting machine components. Methodology. The research uses software packages, with the help of which a computational-theoretical apparatus is developed for heat mode modeling processes. In particular, the mentioned function is used in the SolidWorks Simulation software with the ability to evaluate the errors of the calculation results. Findings. In the course of the research, the dependence of the hoisting machine disc brake performance on the operating parameters of its components was determined. The research has led to a better understanding of the heat transfer processes in disc braking devices, as well as the ability to study the friction response of various materials and determine optimal parameters that help improve the performance of braking systems. The effectiveness has been proven of the proposed method for analyzing the heat distribution processes of the mine hoisting machine drum components under the influence of operating and emergency braking modes. Originality. For the first time, a methodology for calculating the heating temperature distribution along the brake rim plane during a safety stop has been developed and substantiated. A method has also been developed for determining the temperature field arising under steady-state heating conditions, which occur after repeated operating braking and cooling of the device. In this case, when using the formula for determining the temperature on the brake rim surface, the sample length, the relative velocity between the friction components and the heat flow distribution coefficient are taken into account. The brake disc geometric model developed in the SolidWorks software package makes it possible to study the temperature change on the device rim in real time. Practical value. The proposed design improvement based on the research results of heating processes should improve vehicle safety. The cost of braking systems is expected to be reduced through the use of optimal materials and production technologies. The software methods for modeling and analyzing the temperature influence on brake discs of the Mine Hoisting Machine (MHM) have been improved. Based on the research results, recommendations have been developed for the optimum braking process of machines in various operating conditions. [ABSTRACT FROM AUTHOR]

В работе выполнены обработка и анализ долговременных рядов вертикального распределения температуры в средней атмосфере (интервал высот 15-60 км) над Томском, полученных на базе регулярных измерений лидарной станции Института оптики атмосферы СО РАН за период 2010-2023 гг. За данный период было накоплено и обработано порядка 1000 суммарных сигналов обратного рассеяния на длине волны 532 нм. На основе полученных экспериментальных данных выявлены региональные особенности внутри- и межгодовой изменчивости термического состояния средней атмосферы над Западной Сибирью. Для теплого периода каждого года (с мая по сентябрь) установлено стабильное распределение температуры с отличием до нескольких К по отдельным годам. Весной и осенью отличие среднемесячных профилей температуры возрастает до 5-10 К и в январе достигает максимума 15 К. Выявлено принципиальное отличие вертикального распределения температуры, построенного по лидарным данным, и предлагаемой моделью CIRA-86. С октября по апрель в интервале высот от 15 до 25 км лидарный профиль температуры сдвинут от модельного в отрицательную сторону, выше от 25 до 50 км в положительную. Максимальный отрицательный сдвиг профилей отмечается в декабре и составляет 16 К, а отрицательный до 15 К в январе. Приводится описание методов анализа ряда экспериментальных данных на наличие значений, которые значительно отличаются от остальной части данных и могут привести к искажению полученных результатов

Для ефективної роботи гідросистем промислового і мобільного гідроприводу важливо враховувати температуру робочої рідини, яка впливає на втрати потужності, включаючи гідро-механічні втрати, такі як тертя в трубах, і об’ємні втрати, такі як втрати через витоки. Для гідросистем з високими вимогами до ефективності і точності позиціонування вихідної ланки, значна увага має бути приділена впливу температури рідини на характеристики регулюючої апаратури, по-ширеним видом якої є регулятор витрати. В статті проведено аналіз принципової схеми, конструктивних особливостей і геометричних параметрів трьох-лінійного регулятора витрати з пілотним пропорційним керуванням і сил, які діють на його внутрішні елементи. Висунуто дві гіпотези, які пов’язують конструктивні особливості з відхиленням витрати через регулятор витрати при зміні температури робочої рідини. Проведено експериментальне дослідження впливу температури на витратну характеристику регулятора витрати. Встановлено, що збільшення температури робочої рідини зменшує витрату через регулятор при сталому значенні керуючого сигналу. Запропоновано спосіб компенсації відхилення від початкового налаштування витрати шляхом врахування поточного значення температури робочої рідини в алгоритмі керування програмованого логічного контролера. Для технічної реалізації запропонованого методу необхідно додати в гідравлічну систему контроль температури і внести зміни в алгоритм керування регулятором витрати.

Різкі зміни температури та вологості повітря негативно впливають на вирощування сільськогосподарських культур. Сучасні методи регулювання мікроклімату тепличних об’єктів здебільшого зводяться до регулювання потоку та температури повітряних мас. Метою цієї роботи є аналіз теплового випромінювання тепличного об’єкту та створення мехатронної системи керування елементами нагрівання. Виконано моделювання однієї доби в Херсонській області (23 травня 2023 року). Вплив водяної пари на теплове випромінювання і змішаний механізм конвекції всередині теплиці не враховувалися при дослідженні. Для спрощення аналізу, теплиця була змодельована без рослин, оскільки така повна імітаційна модель виходить за рамки цього дослідження. Цей аналіз призводить до точної оцінки загального коефіцієнта теплопередачі і теплового потоку теплиці, що послугувало основою для створення і тестування (перевірка правдоподібності) спрощеної програми керування системою мікроклімату теплиці. Результати дослідження і розроблена програма керування калориферами придатні для використання в алгоритмах керування мехатронною системою теплиці для врахування циклічних добових змін параметрів.

The I-V characteristics of heterostructures n-GaAsp-(ZnSe)1-x-y(Ge2)x(GaAs1-δBiδ) exhibit a characteristic quadratic law - J~V² I-V curve, followed by a sharp pre-breakdown current growth, which well explains the observed straight branch of the I-V characteristics and this regularity remains unchanged at different temperatures. The analysis of the I-V characteristics of n-GaAs-p-(ZnSe) 1-x-y(Ge2)x(GaAs1-δBiδ) heterostructures with an extended intermediate solid solution layer shows that the drift mechanism of charge transport predominates under forward bias conditions. [ABSTRACT FROM AUTHOR]

A quantitative theory of two-photon linear-circular dichroism caused between the subbands of light and heavy holes of the valence band and conduction band is constructed, which takes into account the admixture of valence band states to the conduction band states and the temperature dependence of the band gap (Eg(T)) in semiconductors of tetrahedral symmetry in the multiband Kane model. It is shown that the type of oscillatory angular dependence or the amplitude values of the probabilities of two-photon optical transitions depend on the state of light polarization. This is due to the fact that, under the influence of linearly polarized light, alignment along the pulse occurs, and under the action of circularly polarized light, the moments of current carriers are oriented. It has been determined that the probability of two-photon optical transitions from the heavy hole subband to the conduction band of semiconductors at a fixed temperature increases with increasing frequency, passes through a maximum, and sharply decreases regardless of the degree of polarization of light, as well as the band gap. [ABSTRACT FROM AUTHOR]

The photoelectric properties of n-GaAs – p-(GaAs)1–x–y(Ge2)x(ZnSe)y heterostructures have been investigated both in photodiode and photovoltaic modes. It has been revealed that the spectral dependence of the photocurrent covers a wide range of energy intervals, ranging from 1.07 eV to 3 eV. It has been demonstrated that as the temperature of the crystallization onset (Toc) increases, the peaks of the spectral dependencies of the photoelectromotive force (photo-EMF) shift towards shorter wavelengths. It has been observed that as the crystallization onset temperature (Toc) of the solid solution layer (GaAs)1–x–y(Ge2)x(ZnSe)y increases, the lifetime of photo carriers increases from 10-7 s at Toc=650°C to 5ꞏ10-5 s at Toc=730°C. It is demonstrated that the peaks of the intrinsic photoluminescence band shift towards shorter wavelengths with an increase in the temperature of the crystallization onset. Additionally, the study of the intrinsic spectral region of photoluminescence in samples across the thickness of the epitaxial layer confirms the variability of the obtained structures. [ABSTRACT FROM AUTHOR]

This study investigates the impact of ambient conditions on the performance of P3HT/Ru-dye/nc-TiO2 solar cells (TLSCs). It has been found that the increase of temperature and irradiation duration affect on the parameters of TLSCs. When the temperature was increased from 293 k to 393 k, the short circuit current density (Jsc ) and open circuit voltgae (Voc) decrease from 2.2 to 1.7 mA/cm² and 0.7 V to 0.5 V respectively. That is attributed to the effect of high temperature on recombination of photo-generated charges and reduction of shunt resistance (Rsh ) in the TLSC. Moreover, we also present the effect of irradiation duration on performance of the TLSCs. The measurement reveals that Jsc decreased by 0.5 mA/cm² while Voc decreased by ~ 0.18 V during 4800 s illumination. This decrease suggests the filling of traps or defects at the interface with photo-genertated charges. Finally, the maximum output power of TLSCs dropped by almost half within 6 days during a 20-day test because of affecting atmosphere moisture on the interface properties between dye/ nc-TiO2 and P3HT [ABSTRACT FROM AUTHOR]

The advantages of the method of heating dielectric materials in the microwave field, which are based on the features of the conversion of electromagnetic energy into heat directly in the volume of the layer, are considered. The transformation of the energy of the microwave field into thermal energy in the volume of the material can lead to unique effects that are not manifested when using traditional methods of heat treatment, such as changing the internal structure of the material, which makes it possible to obtain a final product with qualitatively new properties. It is determined that processes based on microwave heating of materials with sufficiently high dielectric coefficients have a great potential for energy efficiency. Heating in a microwave field is an alternative to traditional methods, but it is not used for many technologies on an industrial scale due to the insufficiently studied features of the absorption of microwave energy by a specific material and the possibility of negative phenomena, such as large temperature inhomogeneities, local overheating, low efficiency of converting the energy of the microwave field into internal material energy. The main focus of the work is focused ondetermination of the effectiveness of microwave heating for the regeneration of zeolites. Interest in the use of zeolites is determined by a wide range of applications, includingtechnology of heat storage without loss for long periods of time. The results of research on drying a dense layer of zeolite 13X in a microwave field and an assessment of the influence of dielectric characteristics on the energy efficiency of the conversion of microwave energy into heat are presented. The results proved that the drying of zeolite 13X is somewhat more intensive compared to zeolite 4A. A comparison of the dielectric properties of 13X and 4A zeolites, which significantly affect the conversion of the energy of the microwave field into heat and energy efficiency, was carried out. [ABSTRACT FROM AUTHOR]

Pulsating heat pipes (PHP) are novel heat transfer devices which have wide prospects of application in energy, refrigeration, cryogenic systems and electronics cooling because of simple design and high efficiency of heat transfer. However, heat transfer characteristics of PHP depend on many parameters. This paper is dedicated to experimental investigation of the impact of heating zone length and angle of inclination on the start-up and operational characteristics of PHP. The investigation involved a systematic variation of the heating zone length and inclination angle with measuring of key performance indicators, including start-up heat flux density and temperature, transient heat flux density, and thermal resistance, for water, methanol and pentane as a heat carrier. 5-turn PHP made of copper capillary tube with inner diameter 1,1 mm was used as experimental sample. Main operational modes of PHP were defined and described in the paper based on obtained experimental data. Results indicate that increasing the heating zone length from 10 to 50 mm at all tested inclination angles significantly enhances the thermal performance of PHP by reducing start-up, transient heat flux densities and thermal resistance. Specifically, thermal resistance decreased by up to 51,8% and start-up, transient heat flux densities up to 68-71% with longer heating zone lengths. Also, it was shown that maximum transferred heat flux increased up to 59% with increasing in heating zone length. These findings suggest that optimizing heat zone length can improve start-up efficiency and overall heat transfer performance. The impact of inclination angle varies with the coolant used; generally, water outperforms methanol and pentane across all orientations. Methanol ranks next, with pentane showing the least performance. However, methanol and pentane are viable choices for low heat flux applications in vertical bottom heating mode. The study provides valuable insights for the design of PHP in energy, refrigeration and electronics cooling systems, highlighting the importance of heating zone (HZ) length configuration in achieving optimal performance. [ABSTRACT FROM AUTHOR]

Due to the impact of various types of pollution on the available water resources, inland waters are facing a decrease in water quantity and the quality of surface waters is deteriorating. Tributaries of the Saigon River are an important feature of the river, Ho Chi Minh City. The tributaries selected were mainly located in Binh Chanh District. In this context, assessing the quality of surface waters is an essential, critical and challenging activity to be undertaken to protect these waters. At 31 research sites (n = 31), surface water was collected from upstream to downstream tributaries. Monitoring parameters included Temperature, pH, Electrical conductivity (EC), Total dissolved solid (TDS), Ammonium nitrogen (NH4+-N), Nitrate nitrogen (NO³ –-N), Phosphate (PO4 ³ –), Iron (Fe), Zinc (Zn) and Copper (Cu). In terms of data analysis, the results of this study will provide valuable information for the improvement of water quality in the study area. Ecological and economic zoning through the 31 research sites has been mentioned. The results of these water parameters can be specifically discussed and have comparisons with the previous studies. Finally, the results were synthesised to describe the variation in water quality values across the study area in the wet season. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the evapotranspiration (ET) of sudangrass for silage first crop grown under optimum irrigation conditions on meadow-cinnamon soil. For the area of the town of. A field experiment was carried out with sudangrass (cv. Endje-1) during the period 2021-2023 for the field experiment in Stara Zagora (Bulgaria). On the basis of tracking the dynamics of soil moisture (75-80%) of the FC the following variants were studied: lime. 1 - no irrigation, var. 2 - optimum irrigation - 100% irrigation rate, var. 3 - irrigation with 70% of the calculated irrigation rate and var. 4 - irrigation with 40% of the calculated irrigation rate. Evapotranspiration (ET) was established for optimally irrigated variant 2 by water balance calculations. For the soil-climatic conditions of the region,the mean daily ET of sudangrass, during the three years of the study was dependent on the weather conditions during the months of active crop vegetation and ranged from 0.90 to 4.23 mm. ET reached its maximum in the emergence phase (4.4 mm) per day in the middle of the second ten days of August. The total evapotranspiration of the sudangrass, while maintaining 75-80% of the ET, averaged 290.43 mm over the experimental study period. [ABSTRACT FROM AUTHOR]

Metal-polymer composite materials were tested at ambient temperatures of 20 and 60 °C. The most modern composite wear-resistant materials used in mechanisms as sliding bearings were used. The relevance of the tests is determined by the application of worldwide trends to mechanisms without maintenance for the entire life cycle. The influence of temperature on the wear resistance of metal-polymer composite materials that can be used in aviation spherical plane bearings is determined. It was determined that heat generation caused by both the friction process and dynamic load as a result of reverse motion has the greatest influence on the wear intensity. Increasing the test temperature affects polymer composite materials to a greater extent than metal-polymer tape. At this stage, a significant role in wear resistance is played with the ability of the material to dissipate heat, which occurs in the contact zone from reversible sliding. It has also been established that the carbon fabric of the Fluroglide material can withstand higher temperatures than the babbitt of the metal-polymer tape. A key role in the durability of spherical plane bearings that work in non-standard temperatures will be played by the composite materials design selection and the polymer materials themselves for specific operating conditions [ABSTRACT FROM AUTHOR]

Currently, interbreeding has become quite widely used in global dairy farming, which improves reproductive characteristics, resistance and health indicators, duration of productive use, and quality composition of milk in individuals of the first generation. The purpose of this work was to compare the qualitative composition of milk and its suitability for processing into cheese in cows of the Ukrainian redspotted dairy breed and their crossbreeds with the Montbeliarde breed. The research was carried out at the enterprise “Azorel” LLC, Vinnytsia District, Vinnytsia Region (49°57′01″N, 28°47′09″E). The farm keeps cows of the Ukrainian red-spotted dairy breed and crossbreeds of the first generation obtained as a result of crossing with the Montbeliarde breed. Two groups of (pure-bred and cross-breed) analogue cows were formed with the number of 17 cows each in the 2nd-3rd months of lactation. Research was conducted during July 2021 during the period of high temperature load (average daily air temperature was +23.2 °C). It was established that during the study, the temperature-humidity index (THI) was in the acceptable range (70.5) during the period from 08.00 to 10.00, and 71.6–78.8 from 10.00 to 22.00, which is a sign of moderate heat stress The average daily temperature and relative humidity during these hours were 23–32 °С and 37–64 %, respectively. In general, long-term high-temperature loads became a significant stress factor, which affected both the productive characteristics of animals of both groups, as well as the syrupability and physicochemical properties of milk. The interbreeding of the Ukrainian red-spotted breed with the Montbeliarde breed had a positive effect on the indicators of nutrients in milk, such as the content of fat, protein, lactose, as well as on the suitability of milk for processing into cheese. Local first-born cows had higher indicators of the theoretically possible output of rennet cheese and the energy value of milk. In addition, milk samples from crossbreeds were characterized by a shorter coagulation phase and a higher class of rennet clot characteristics. [ABSTRACT FROM AUTHOR]

For Ukrainians, potatoes are a key foodstuff and the most important strategic crop in the vegetable segment, and therefore it is vital to investigate the quality characteristics of potato tubers. The purpose of this study was to investigate the influence of various meteorological factors on the taste and starch content of tubers of different potato cultivars. The study employed laboratory, analytical, mathematical, and statistical methods. Both positive and negative correlation between starch content in tubers, taste, average monthly temperature, and precipitation were found in cultivars of different ripeness groups. For some potato cultivars, the positive effect on the starch content in tubers was due to the synergistic interaction of temperatures in August and precipitation in July, while for other cultivars this effect was determined by temperature and precipitation in August. It was found that an increase in temperature in August contributed to the improvement of the taste characteristics of early-ripening cultivars, while for middle early and mid-ripening genotypes, increased temperatures in June and August were key factors, and middle-late cultivars responded to increased precipitation in August. For each of the 19 cultivars studied, periods with a positive effect of average monthly temperature and precipitation on the improvement of taste were identified. The cluster analysis helped to identify potato cultivars with high starch content - Lietana, Opillia, Vzirets, and Oleksandryt, with high taste qualities - Lietana, Mezhyrichka 11, Vzirets, Avanhard, Partner, Oleksandryt, Fanatka, Rostavytsia, and Opillia. The findings of this study can serve as a scientific basis for the formulation of policies aimed at mitigating the effects of climate change and adapting existing cultivars to support sustainable potato production in a particular region and creating new plastic potato genotypes with sustainable quality characteristics. [ABSTRACT FROM AUTHOR]

При массовом содержании нимф Macrolophus pygmaeus в условиях избыточного кормления яйцами Sitotroga cerealella, наличия воды и листа растения их выживаемость достоверно ниже при более низкой температуре 20–22 °C, в сравнении с температурами 24–25 °C и 27–28 °C во всех вариантах плотности личинок. Развития достоверно более продолжительное в варианте с температурой 20–22 °C. При этом дружность выхода имаго достоверно больше также при 20–22 °C. Вес имаго определяется только полом и не зависит ни от температуры, ни от плотности содержания нимф. Снижение выживаемости при 20–22 °C мы связываем с проявлением каннибализма при нарушении потребления воды и пищи, снижением прибавки веса (в 1.3 раза при наличии воды и 1.5 раза при наличии воды и корма) и десинхронизации возрастного состава личинок в первоначально одновозрастной группе. В результате разной скорости развития личинок в группе более крупные личинки уничтожают отстающих в развитии, что приводит к выравниванию возрастного состава и дружному выходу имаго, но снижению доли полученных имаго. Плотность содержания личинок достоверно влияет только на их выживаемость и проявляется при более низких температурах 20–22 °C и 24–25 °C. Однако несмотря на то, что между низкой и высокими плотностями содержания личинок различия выживаемости достоверны, они не велики и при массовом разведении ими можно пренебречь в пользу более высокой плотности содержания, позволяющей интенсифицировать производство M. pygmaeus.

Штампування круглих порожнистих напівфабрикатів гарячим зворотним видавлюванням є однією з початкових операцій при виготовленні порожнистих виробів спеціального призначення. На зусилля і формозміну металу при гарячому пластичному формоутворенні суттєво впливає швидкість деформування або швидкість переміщення деформуючого інструменту. Для виробів спеціального призначення потрібно забезпечити певні механічні властивості по висоті стінки і в донній частині. Властивості по висоті стінки забезпечуються на подальших переходах витягування з потоншенням напівфабрикату, що отримано гарячим видавлюванням, при якому здійснюється пропрацювання структури металу пластичною деформацією з досягненням необхідних властивостей. Тому актуальною задачею є дослідження впливу швидкості деформування на зусилля і формозміну металу при гарячому зворотному видавлюванні порожнистих напівфабрикатів. Визначення за допомогою моделювання методом скінченних елементів (МСЕ) впливу швидкості деформування на параметри гарячого зворотного видавлювання з роздачою порожнистих напівфабрикатів із заготовок круглого і квадратного перерізу та порівняння результатів теоретичних досліджень. Теоретичні дослідження силових режимів видавлювання, питомих зусиль та напружено-деформованого стану металу проведено моделюванням з використанням МСЕ в програмному середовищі DEFORM. За допомогою МСЕ проведено моделювання процесу гарячого зворотного видавлювання з роздачою із маловуглецевої сталі круглих порожнистих напівфабрикатів з виступами на торці донної частини зі сторони порожнини та на зовнішній поверхні. Швидкість деформування була у межах 20-80 мм/сек. Використані заготовки круглого і квадратного перерізу. Встановлено залежності зусилля видавлювання від переміщення пуансону. Виявлено розподіл питомих зусиль на деформуючому інструменті. Визначено напружено-деформований стан та температурний розподіл у здеформованому металі в кінці видавлювання. Проведено оцінку пропрацювання структури металу гарячою пластичною деформацією та виконано порівняння отриманих результатів. Встановлено вплив швидкості деформування на параметри гарячого зворотного видавлювання з роздачою круглих порожнистих напівфабрикатів.

Гомогенізація є стандартним процесом обробки молока, який використовується для стабілізації жирової емульсії від гравітаційного осадження. У молочній промисловості зазвичай застосовується гомогенізація під високим тиском, що вимагає значних енерговитрат для досягнення оптимальних умов обробки. Розмір і склад мембрани жирових кульок впливають на сенсорні та реологічні властивості вторинних молочних продуктів [1]. Останнім часом для гомогенізації молока часто використовують ультразвук [2]. На відміну від ультразвуку, механічне змішування не забезпечує стабільності емульсій навіть після тривалої обробки, що підкреслює відмінності між цими двома технологіями. Ці відмінності виникають через різний ступінь руйнування жирових кульок та мембран. Проте, молочні продукти з різними фізико-хімічними та функціональними властивостями можуть бути виготовлені як за допомогою ультразвукової обробки, так і в поєднанні з іншими традиційними методами гомогенізації. Дослідження впливу параметрів ультразвукової обробки молока, а саме різних їх значень, на розмір жирових включень та стабільність молочної емульсії протягом певного часу після обробки. В роботі було використано дослідний метод обробки молока за допомогою ультразвукової кавітаційної установки. Досліджено вплив ультразвукової кавітації на якість гомогенізації молока в сталому об’ємі. Експериментальним шляхом визначено оптимальні параметри процесу, а саме потужність ультразвукового поля та час обробки. Встановлено недоцільність використання частоти ультразвуку більшої за 33 кГц. Експериментальним шляхом було доведено надзвичайну ефективність ультразвукової кавітаційної обробки молока для отримання однорідних емульсій. З огляду на те, що надмірне нагрівання (˃ 65 °С) є небажаним при виробництві молочних продуктів з технологічної точки зору, безумовною перевагою цього методу, є низькотемпературний (50 °С), у порівнянні з традиційними способами обробки (75–80 °С), режим, що також позитивно впливає на збереження поживних речовин.

The object of the study is the process of changing tribological efficiency according to tribotechnical characteristics (wear intensity, friction coefficient, temperature in the contact zone) of composites based on phenylone C-1 and polyamide PA-6 with arimide-T filler and fullerene C-60. The study solved the problem of obtaining composites with high wear resistance. Based on the results of research, it was found that varying the content of arimide-T makes it possible to obtain composites with different patterns of changes in tribotechnical characteristics under conditions of dry friction, lubrication with water and I-50 oil. Composites with the composition: phenylone C-1+15 wt. have the maximum tribological efficiency. % arimide-T+3 wt. % fullerene C-60 and polyamide PA-6+30 wt. % arimide-T+3 wt. % fullerene C-60. Phenylone C-1 has destructive properties when working in the environment of water and temperature in the friction zone. Its reinforcement with arimide-T and fullerene C60 gave positive results of a complex of tribotechnical characteristics under these conditions. It was found that the wear of composites based on phenylone C-1 in I-50 oil is two orders of magnitude lower than in water. Research of samples from the obtained composites based on phenylone C-1 and polyamide PA-6, reinforced with the optimal content of arimide-T and fullerene C60, showed that their wear resistance when lubricated with oil is 3.5...4.0 times greater than the wear resistance of bronze. An applied aspect of the reported results is the introduction of manufacturing technologies and restoration of machine parts from the proposed composites. It has been proven that their optimal composition contributes to high tribological efficiency and could provide the required level of wear resistance and reliability of resource-determining nodes, systems, and machine assemblies. The results could be used by machine-building and repair-technological enterprises [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental studies on the developed bone degreasing stand. The object of the study is the production of valuable components from organic raw materials. Fractions of cattle crushed to the size of 2.5 mm, 5.2 mm and 10.5 mm were used to identify the effective mode of operation of an electrohydroimpulse installation. Physical and chemical methods of fat extraction are currently not relevant from the point of view of economy, due to environmental damage and labor intensity. In this regard, new effective methods of extracting fat from bone mass are needed. Therefore, the proposed method of extracting fat by spark discharge is an actual and alternative method for today. During the study, an acceptable temperature regime for fat production was obtained. Next, a laboratory stand was assembled, with which you can degrease the bone mass without changing the properties of fat. Experimental studies show that with an increase in the capacity of the capacitor bank in energy storage devices and the length of the discharge gap, the bone degreasing process becomes more efficient. During the study, it was found that at a liquid temperature of 38 °C and a pulse voltage of 25 kV on a switching device of an electrohydroimpulse installation, the degree of fat extraction increases without destroying the morphological structure of bone mass. Using the hexane extraction reaction, we determined the efficiency of fat extraction at a temperature of 38 °C, at which the fat mass from the bones is effectively broken down, and using the UV-1800 spectrophotometer, we determined the amount of protein in the bones before and after treatment. The study also showed that with a capacitor bank capacity of 0.5 uF, crushed to a fraction of 10.5 mm of pelvic bone, the separated fat is 18.7 %, and with constant grinding of the capacitor bank to a fraction of 2.5 mm – 19.4 % [ABSTRACT FROM AUTHOR]

For the efficient operation of hydraulic systems of industrial and mobile hydraulic drives, it is important to consider the temperature of the fluid, which affects power losses, including hydro-mechanical losses, such as friction in pipes, and volume losses, such as losses due to leaks. For hydraulic systems with high requirements for the efficiency and accuracy of the positioning of the output link, considerable attention should be paid to the influence of the fluid temperature on the characteristics of the regulating equipment, a common type of which is the flow control valve. The article analyzes the schematic diagram, design features, and geometric parameters of the three-way flow control valve with pilot proportional control and the forces acting on its internal elements. Two hypotheses have been put forward, which connect the design features with the deviation of the flow through the flow control valve when the temperature of the fluid changes. An experimental study of the effect of temperature on the flow characteristics of the flow control valve was carried out. It was established that an increase in the temperature of the fluid reduces the flow through the flow control valve at a constant value of the control signal. A method of compensating the deviation from the initial flow setting by taking into account the current value of the temperature of the fluid in the control algorithm of the programmed logic controller is proposed. For the technical implementation of the proposed method, it is necessary to add temperature control to the hydraulic system and make changes to the control algorithm of the flow control valve. [ABSTRACT FROM AUTHOR]

The composition, functions, and characteristics of microclimate systems in small greenhouses are analyzed. The features that ensure the creation of favorable conditions for growing plants are identified. It is proposed to choose temperature and humidity as the parameters of priority provision. It is taken into account that modern methods and systems of microclimate of greenhouse facilities are focused on the regulation of air mass flows and heat exchange flows. The aim of the study is to create a mechatronic system for controlling air mass flows and heating elements to ensure heat balance in a greenhouse, taking into account the thermal radiation of the greenhouse object and heat exchange processes in a closed volume. A feature of the approach is a biased algorithm for controlling heat and mass transfer processes based on a daily weather forecast. A computer model of a greenhouse facility has been substantiated and developed, which takes into account heat exchange processes in the greenhouse, heat exchange with the external environment, added heat output by heaters, convection and forced air movement in the greenhouse. The study does not take into account the effect of water vapor on thermal radiation and the mixed convection mechanism inside the greenhouse. To generalize the model, the greenhouse was modeled without plants. Based on the results of the research, a mathematical model of changes in the heat flow of the greenhouse during the day was developed in SOLIDWORKS software. A one-day simulation of changes in air parameters in a greenhouse was performed to forecast the weather in the Kherson region (May 23, 2023). The simulation was based on the design parameters of the greenhouse, an initial temperature of 20 °C in the greenhouse, and an ambient temperature ranging from 14 °C to 20 °C according to the weather forecast. The modeling results were used to determine changes in the heat flux density on the greenhouse surfaces and the total heat output of heat exchange processes. It was found that the obtained characteristics provide an estimate of the total heat transfer coefficient and heat flux of the greenhouse, which served as the basis for determining the required power of heaters and developing a control cyclogram for the greenhouse temperature stabilization system. Based on the results of the model experiment, an operating mode for the heaters was developed. The results of the study and the developed algorithm for controlling heaters are suitable for use in mechatronic microclimate control systems, taking into account daily changes in environmental parameters. [ABSTRACT FROM AUTHOR]

In this research, a comprehensive study of the effect of doping silicon with gold on the optical properties and morphology of silicon layers was carried out. For this purpose, the methods of Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used. The results of the study showed that the transition from original silicon to gold-doped silicon leads to significant changes in the optical properties and morphology of the layers. Raman spectra showed characteristic peaks in the regions of 144, 304, 402, 464, 522, 948 and 973 cm-1, associated with the violation of long-range order of the crystal lattice and the interaction of gold with silicon. The intensity and position of the peaks in the spectra allowed us to draw conclusions about structural changes, including a decrease in crystallinity and the formation of amorphous and nanocrystalline structures in the samples after treatment at 1373 K. New peaks in the Raman spectra associated with Au-Au stretching and the formation of new bonds Si-Au, confirm the processes in silicon layers when alloyed with gold. SEM studies provided information on the structure, chemical composition and arrangement of n-Si-Au and p-Si-Au samples. The spherical arrangement of gold atoms on the surface of single-crystalline silicon was experimentally established, which indicates the diffusion of gold and the formation of gold silicate, which introduces a positive charge to the interface. Morphological changes included an increase in the number of agglomerates with nanocrystals smaller than 7-9 nm and an increase in the transparency of the layer. These results indicate the possibility of improving the photosensitivity of heterostructures with a Si-Au composite layer due to the quantum-size and plasmonic effects of inclusions containing silicon and gold nanoparticles. [ABSTRACT FROM AUTHOR]

The study of thin-film nanocomposites, including crystalline and amorphous silicon nanoparticles embedded in silicon oxide layers, is a key direction in the field of materials for optoelectronics. This study explored the interest in such composites, including erbium silicide (ErSi2-x), in the context of their applications in non-volatile memory and photovoltaic devices. Particular attention was paid to the structure and properties of such materials, including the analysis of defects in erbium-doped silicon. The results of the study, based on Raman spectroscopy and X-ray phase analysis, made it possible to identify the characteristics of the composition and structure of the studied samples. The identified data confirmed the presence of crystalline phases of Si and Er in the p-Si-Er composite, and also showed the substitution of Er in the p-Si/SiO2 structure. Additionally, X-ray microanalysis data confirmed the presence of Si, O and Er in the expected concentrations in the composite film. Further research showed that the introduction of erbium atoms onto the silicon surface leads to minor changes in some signals and the appearance of new vibrations in the Raman spectra of the samples. The decrease in the intensity of the peaks belonging to silicon is associated with the weakening and breaking of some bonds in the structure of the silicon crystal lattice and due to the formation of new bonds in which erbium atoms participate. Thus, the results of this study represent a significant contribution to the understanding of the properties and potential of thin film nanocomposites for applications in optoelectronics, and also enrich our knowledge of the effect of doping on the structure and properties of silicon materials. [ABSTRACT FROM AUTHOR]

In this work, the structural and optical characteristics of silicon (n-Si) samples and its compositions with dysprosium (n-Si-Dy) were analyzed using Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy methods. Characteristic peaks in the FTIR spectra such as 640 cm-1 (Si-H mode) and 1615 cm-1 (perpendicular stretching mode) were identified, indicating the structural features of the material. The appearance of additional peaks in the n-Si-Dy spectra at 516.71 cm-1 and 805 cm-1 indicates the influence of dysprosium on the structure and defectiveness of the material. Examination of the frequency range (1950-2250 cm-1) further confirms local vibration modes associated with defects and interactions with dysprosium. Peaks associated with Dy-Dy stretching, as well as interaction with silicon, were found at 2110 cm-1 and 2124 cm-1. Analysis of Raman spectra indicates the formation of silicon nanocrystals during annealing, which is confirmed by XRD results. The results obtained provide important insight into the effect of dysprosium on the structure and properties of silicon materials, which could potentially find application in optoelectronics and materials science. [ABSTRACT FROM AUTHOR]

The present work is devoted to studying the effect of temperature on the formation of a submicron-sized particles of lead sulfide (PbS). Lead sulfide samples were obtained by chemical bath deposition method. 25 ml of an aqueous solution of lead nitrate Pb(NO3)2, 75 ml of sodium hydroxide NaOH and 50 ml of thiourea CH4N2S with molar concentrations of 0.18 M (1.52 g), 0.38 M (1.151 g) and 0.11 M (0.397 g), respectively, were used as reagents. In the process of obtaining samples, solutions of lead nitrate and sodium hydroxide were initially mixed at temperatures of 70℃ and 100℃, then a thiourea solution was added to this mixture. It was found that temperature has an effect on the formation of PbS structures. It is shown that at a temperature of 100℃ isolated particles are formed, whereas at a temperature of 70℃ a film is formed. The morphology and elemental composition of the obtained lead sulfide (PbS) samples were studied by scanning electron microscopy (SEM) and the surface structure was studied using an atomic force microscope (AFM). As a result of the study of the morphology and texture of the surface of lead sulfide samples, the average size of isolated particles was determined, which is ~144 nm, and these particles also had a cubic shape with a smooth surface. [ABSTRACT FROM AUTHOR]

We propose an original method for the production from biomass two synthetic gases of different composition and calorific value in one reactor: low-calorific gas - CO2 = 3.36 %, CO = 32.9 %, H2 = 17.65 %, H2О = 3.72 % and N2 = 42.35 % with a calorific value of 6066 kJ/nm3 and medium-calorific one - CO2 = 9.2 %, CO = 34 %, H2 = 13%, H2O = 24 %, C1.16H4 = 19 % (70 % CH4+30 % C2H4), C6H6.2O0.2 = 0.54 % and N2 = 0.23 % with a calorific value of 14581 kJ/nm3 and a low tar content. The experimental unit consists of two fixed bed pyrolyzers with an air fountain (or pneumatic transport) and a Bagasse coke-ash residue fixed bed gasifier. The fixed bed pyrolyzer consists of two concentric cylinders with electric heaters on their surfaces. The fixed bed of pellets is located in the gap between the cylinders. Two versions of the pilot plant are presented. In the first of them, rapid pyrolysis in a fixed bed occurs under the influence of three external sources of thermal energy: two electric heaters located on the walls of the cylinders and the recirculation of high-temperature pyrolysis gases, which makes it possible to achieve high heating rates of Bagasse pellets in a fixed bed - 736-1389 С/min. To reduce the consumption of electric energy, the second variant provides a combined energy supply: 50% of electric energy and 50% of thermal energy from flue gases with a temperature of 1300 С. In the aerofoil (or pneumatic transport) mode, pyrolysis occurs due to the thermal energy of flue gases with a temperature of 850-950 С, which heat the outer surface of the shell, and the thermal energy of the carrier medium (recirculating pyrolysis gas with a temperature of 800С). [ABSTRACT FROM AUTHOR]

A microwave-convective dryer for seed grain is considered as an effective drying system that allows reducing energy consumption. It is emphasized that for optimal design and cost-effective operation, as well as proper observance of optimal storage conditions for agricultural products, in particular grain products, it is advisable to use microwave heating with simultaneous blowing of air through the layer and to ensure utilization of air heat from the magnetron cooling system. It was determined that one of the main problems of using a microwave field for processing dense layers of grain is to ensure sufficient uniformity of the distribution of the microwave field. It is emphasized that the use of horn-type waveguides makes it possible to effectively irradiate grain with microwave energy. The scheme of the installation for microwave-convective grain drying is proposed, in which horn antennas are proposed as waveguides, closed with fluoroplastic plates to prevent water vapor from entering the working chamber to the waveguide. The calculations of the cooling system of the anode blocks of magnetrons and the calculation of the grain preheating chamber are presented. The heating medium is air blown through the layer in a horizontal direction at a filtration speed of 0.14 m/s. Based on the calculation of the working chamber of a microwave-convective dryer with a dense layer moving with a flow rate of G = 1,25·10-2 kg/s, the power consumed from the network by magnetrons, taking into account the efficiency of the microwave chamber, and the appropriate number of magnetrons are determined. At the drying rate N = 5,8·10-5 с -1 and using three magnetrons with a total power of 3 kW, the specific consumption per kilogram of evaporated moisture will be 5.3 MJ/kg. The use of a heat recovery system in the preheating chamber reduces energy consumption by 1.3 times. [ABSTRACT FROM AUTHOR]

In this study, the object of the research is low-rank coal during the process of thermal heating of five types: brown, high moisture brown, long-flame, coke weakly sintering and coke fusinite. In the research, when conducting thermal and gas analysis in inert media, the problem of using low-rank coal in the thermal heating process to obtain volatile fuel gases was solved by identifying the quantitative and qualitative performance of its behavior. Quantitative indicators are determined as the mass of thermal destruction products: the mass of coal tar and gas products and semi-coke under optimal temperature conditions of their maximum release. Qualitative indicators of coal behavior are components of thermal decomposition products. It is revealed that the behavior of low-rank coals in the process of thermal heating is determined by the degree of metamorphism. In this case, long-flame and brown coals have a lower release of volatile fuel gases than coke weakly sintering and coke fusinite coals due to a lower degree of metamorphism and greater degrees of thermal oxidation and dehydration. Thermal decomposition component ranges consisting of polyaromatic fragments (HCN, C6H12, C4H5N), greenhouse gases (CH4 and CO2), toxic gases (H2S and NH3) and synthesis gases (CO and H2) have the highest share of release. Optimal temperature conditions and ranges for the release of low molecular weight gases used as high calorific volatile fuel gases are obtained. The results can be used in the design, optimization and construction of thermal heating equipment, correction of gasification and pyrolysis processes. Moreover, they can be applied in localized coal tar spots minimization technologies and for designing targeted gases extraction [ABSTRACT FROM AUTHOR]

Purpose. Development of physical and mathematical model linking nanostructured surface layer of coal substance with geodynamic phenomena of coal seam, through adhesion energy of different layers and coal grades, melting temperature of the nanolayer, determination of the role of stress-strain state of the seam in the formation of fine coal and methane at their emissions into the mine workings. Methodology. Mathematical and experimental studies of the regular change in the surface layer of coal substance depending on the grade of coals for different formations of the Karaganda basin; assessment of the influence of the surface layer of coal on the adhesion energy, which determines the stress-strain state of the coal seam. Physical methods for studying the decomposition temperature of methane-bearing coal seams, changes in its concentration, reaction rate of methane release from coals. Findings. A regular decrease in the thickness of the surface nanolayer of coal substance in different coal grades and formations in the metamorphic series of coals is shown. It has been found that this decrease is accompanied by an increase in surface energy and adhesion energy. The connection of gas-dynamic phenomena with stress-strain state of coal seam, which forms fine-dispersed structure of coal, forms of methane location, activation energy of solid coal-methane solution, rate of thermal decomposition reaction, critical stresses determining development of cracks in coal substance is shown. Originality. For the first time, a physical model for calculating the thickness of the surface nanolayer and its surface energy for coals of different grades of the Karaganda basin has been developed; the relationship between the thickness of the nanolayer and the melting temperature, adhesion energy, linking the stress-strain state of the coal bed in the zone of gas-dynamic phenomena and the concentration of methane has been established. The value of internal stresses in the surface layer of coals of different grades has been found to be a constant value. Connection of activation energy of decomposition of solid coal-methane solution from Gibbs energy and methane concentration, which explains its significant amount in gas-dynamic phenomena, has been established. Practical value. The physical and mathematical model describes the influence of surface coal on the processes occurring in the zone of gas-dynamic phenomena and the regularities of their changes depending on the thickness of the surface nanolayer determining such parameters as: stress-strain state, dispersion of coals, as well as the release of a large amount of methane at the sudden release of coal gas into the mine workings [ABSTRACT FROM AUTHOR]

Актуальность работы. Согласно докладам межправительственной группы экспертов по изменению климата (МГЭИК), климатические изменения проявляются не только в глобальном масштабе, но и на региональном уровне. Изменение температурного режима и режима осадков, несомненно, сказывается на агроклиматических показателях территории. Одной из ведущих отраслей Северо-Кавказского региона является сельское хозяйство, которое в достаточной мере зависит от климатических условий и их изменчивости. Так как наиболее востребованными в растениеводстве являются степные ландшафты Северного Кавказа, занимающие 40% всей территории, то тематика исследования представляет не только научный, но и практический интерес. Цель – оценка современных агроклиматических условий степных ландшафтов Северного Кавказа. Задачи – на основе традиционных методов, используемых в агрометеорологии обработать статистический материал, обобщить и интерпретировать полученные результаты, сделать обоснованные выводы о динамике агроклиматических показателей на фоне меняющегося климата. Материалы и методы. Для оценки агроклиматических условий использовались традиционные агроклиматические показатели, такие как суммы среднесуточных значений температуры воздуха за период календарного года со среднесуточной температурой, превышающей 0, 5 и 10°С; даты устойчивого перехода среднесуточной температуры воздуха через 0, 5 и 10°С весной и осенью; средняя температура самого холодного и самого теплого месяцев календарного года; гидротермический коэффициент Г.Т. Селянинова (ГТК). Обработка материала проводилась методами математической статистики с использованием электронных таблиц Excel. Обработаны данные по температуре и осадкам в период с 1961 по 2020 годы по 10 метеорологическим станциям. Результаты. Годовая температура выросла на 0,98оС. Суммы активных температур, превышающих 5 и 10оС, выросли до 10 и 16% соответственно. Зимы стали более мягкими, а лето более жарким. Осадки выросли в среднем на 72 мм. Значение ГТК соответствует таким ландшафтным зонам как степь и лесостепь. Выводы. Наблюдаемые изменения климата степных ландшафтов Северного Кавказа способствуют улучшению условий тепло- и влагообеспечения.

During operation of water-water reactors including KLT-40 type reactors widely used nowadays on icebreakers and floating power units (FPU), the issue of the duration of safe operation of steam generators is acute. The problem is connected with the formation of microcracks in the steam generator water and steam piping during normal operation at power, through which radioactive nitrogen 16N7 enters the steam piping, the content of which in the steam is just a sign of leakage failure of the steam generator second circuit water and steam piping. This effect, further named "leaks", was considered earlier in a number of works of the authors under conditions of cyclic operation of the steam generator water-steam mode. In the present work the main attention is paid to mathematical and physical analysis of the mechanisms causing the formation of microcracks in the steam pipeline of a steam generator arising in the steam pipeline region in which water and steam pressures are balanced, and their effective length is estimated. Calculations of temperature distribution along the steam-pipe thickness in the steam-water transition region at periodic "slamming" of this region with water are carried out. It is shown that depending on the time period of steam-water oscillations, the radial temperature distribution along the tube thickness shows a significant difference in the distribution at a constant temperature on the outer surface of the tube, and the maximum temperature difference is observed in the area of the inner surface of the tube. The distribution of mechanical stresses arising in the tube metal is characterized by a linear dependence of stresses on temperature, the maximum value of which corresponds to the maximum temperature difference characteristic of the area of the inner surface of the tube. This allows us to state that the formation of cracks starts exactly from the area of the inner surface of the tube of the steam generator in the specified transitional area of the tube.

The paper presents the results of lidar studies of the behavior of the thermal regime of the middle atmosphere over Tomsk in the period for 2022. Note that such studies in the monitoring mode at the Institute of Atmospheric Optics SB RAS began in 1994 and are currently ongoing. Particular attention is paid to studying the manifestation of sudden disturbances in the stratosphere caused by winter stratospheric warming (SW). A description of lidar technology for studying the middle atmosphere and the results obtained on this topic in recent years can be found in works [1–8]. The indicated observation period covers periods of disturbed (SP winters 2021/22 and 2022/23), calm (summer) and transitional (spring, autumn) states of the middle atmosphere. Based on the accumulated experimental material, a number of features of the intra-annual dynamics of the thermal regime of the stratosphere for the region of Western Siberia have been established. Thus, winter stratospheric warming occurs annually from November to March, and for the long period of the year April – November, in the vast majority of cases, the vertical temperature distribution is in good agreement with the CIRA-86 model distribution. As primary information for analyzing the observation results for 2022, a data array of 93 total signals accumulated on individual nights was used. The interval of sounded heights extended from 10 to 70 km, the spatial resolution was 192 m. Reception of lidar signals was carried out in the photopulse counting mode with accumulation of 12×10412×104 launches of laser pulses (accumulation time – about two hours per night). Observations were carried out at night under cloudless sky conditions.

The paper considers the photometric characteristics of LED retrofit lamps produced by the Russian-Chinese company Uniel: Uniel LED-G45-6W/4000K, Uniel LED-A60-8W/6500K, and Uniel LED-A60-9W/4000K, designed to replace traditional incandescent bulbs. During the research, comprehensive measurements of photometric parameters (luminous flux, power consumption, color temperature, color rendering index, ripple factor, power factor) have been carried out and the luminous efficacy has been calculated. The results of the measurements have been presented in relation to the supply voltage. Based on the data obtained, an analysis is carried out of the compliance of the initial measured characteristics of the lamps with the values declared by the manufacturer. The analysis of the emission spectra leads to the conclusion that the Uniel LED-A60-8W/6500K lamps are equipped with white light-emitting diodes, the spectrum of which consists of a blue emission band from the semiconductor crystal with a maximum at ~450 nm and a phosphor band with a maximum at ~560 nm, which converts some of the blue emission from the crystal into long-wavelength spectrum. The emission spectra of the Uniel LED-G45-6W/4000K and Uniel LED-A60-9W/4000K lamps, in addition to the blue emission band from the semiconductor crystal with a maximum at ~450 nm, contain emissions from two phosphors, the bands of which have maxima at ~560 nm (green) and ~630 nm (red), which results in a lower color temperature of the LEDs. The paper also provides a detailed analysis of the light power distribution curves, thermal operating conditions, and structural features of the lamps. The research results lead to the conclusion that it is advisable to recommend Uniel LED-G45-6W/4000K and Uniel LED-A60-9W/4000K lamps for use as light sources to replace traditional incandescent lamps because their photometric characteristics comply with the declared parameters and permissible deviations specified in the regulatory standards.

Цеоліти широко використовуються у багатьох галузях промисловості: у водоочисних приладах у якості адсорбентів, іонообмінників, молекулярних сит, у вакуумних насосах сорбційного типу. Також цеоліти використовують у якості каталізаторів багатьох процесів нафтохімії і нафтопереробки. Для ефективного застосування цеолітів необхідно вибрати не тільки правильний тип цеоліту, а й організувати їх регенерацію, тобто видалення вологи, яка здійснюється у процесі сушіння. В даний час сушіння цеолітів здійснюється за використання гарячого повітря, яке нагрівається від електричного нагрівача, або використовується відпрацьоване тепло промислових підприємств. Застосування мікрохвильового нагрівання якісно змінює процес десорбції. Зазначається, що застосування мікрохвильового нагріву дозволяє вести процес набагато швидше, чистіше та з нижчою енергоємністю порівняно з традиційними методами. Крім того, мікрохвильове сушіння може сприяти зменшенню втрати цеоліту. Проведено дослідження кінетики циклічного та безперервного мікрохвильового сушіння цеоліту 4А з насипною щільністю ρ = 780 кг/м3 та рівноважним вологовмістом 13,4 %. Представлено методику експериментальних досліджень та описано експериментальне обладнання. Наведено результати експериментальних досліджень десорбції цеоліту при мікрохвильовому підведенні енергії до зразків з масою 100, 200 та 300 г. Проведено порівняльний аналіз кривих зміни вологовмісту та температури за часом. Наведено результати розрахунків основних теплових характеристик процесу сушіння: теплоти випаровування вологи, теплоти нагрівання матеріалу, корисного теплового потоку, ККД. Проаналізовано можливі причини перерозподілу теплових потоків на випаровування та нагрівання в процесі сушіння. Хід кривих ККД вказує на зміну діелектричних характеристик цеоліту в процесі сушіння

Розглянуто проблему підвищення енергетичної ефективності обертових печей, які використовуються в різних галузях промисловості для термічної обробки матеріалів. Одним з важливих аспектів їх експлуатації є енергетична ефективність, яка залежить від багатьох факторів і загалом характеризує ступень використання теплоти палива для нагрівання матеріалу. Тому вкрай актуальною є проблема пошуку та використання методів зменшення теплових втрат і використання теплоти. У цьому контексті, підігрів вторинного повітря може виявитися одним з важливих методів для підвищення теплової ефективності обертових печей особливо тих, які працюють в режимі для піролізного випалювання таких матеріалів як вугілля, деревина, торф тощо. У роботі досліджена можливість підвищення енергетичної ефективності обертових печей за допомогою підігріву вторинного повітря шляхом регенерації використаного тепла. Запропоновано використання спірального теплообмінника, який дозволяє передавати тепло від корпусу печі до вторинного повітря без перешкоджання обертанню печі. Розроблено математичну модель для числового розрахунку спірального теплообмінника, що дозволяє оцінювати теплові і температурні характеристики теплообмінника. Показано, що за рахунок тепла корпусу можливо підігрівати вторинне повітря до температури 270 °С в кількості необхідній для забезпечення роботи пальника. Проведено аналіз місця встановлення теплообмінника та використання ізоляційного покриття, що дало можливість суттєво зменшити його розміри без зміни сумарного теплового ефекту в порівнянні з теплообмінником встановленим на всю довжину корпусу печі. Показано ефективність використання теплової ізоляції, що дає можливість при її товщині 7 мм додатково підвищити температура повітря на 50 °С. Отримані результати можуть бути корисними для подальших розробок та оптимізації проектів, спрямованих на поліпшення теплообмінних систем в напрямах ефективного використання теплових ресурсів при розробці та експлуатації обертових печей. Результати розрахунку приведені в електронному додатку до статті у вигляді відеофайлу.

The purpose of this paper is to investigate the thermophysical state of a cylindrical rod of constant cross-section and limited length. This paper is devoted to the automation of the study of the thermophysical state of a rod of constant cross-section and limited length. The process of automating research relies on the laws of conservation of energy. A three-dimensional body is considered, the constant cross section of which has the shape of a cylinder. However, due to the complexity of the studied phenomena, to solve analytically partial differential equations by modern mathematical methods. There are also many solution methods suitable for practical use. The problem is solved by reduction to a partial derivative equation in a cylindrical coordinate system, for the solution of which an appropriate algorithm is developed. The obtained results are translated into Cartesian coordinate system. This solves the original problem. A program for finding the temperature propagation along the rod has been developed, which puts the results of numerical calculations into several files. The results of numerical calculations in dynamics (by time) are output in the form of a table and displayed as one-dimensional graphs. A promising direction is the application of interval mathematics to the study of the heat conduction equation. [ABSTRACT FROM AUTHOR]