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The paper presents a comparative theoretical analysis of the movements of the curved rods of various curvature forms, which can be applied as tools for ultrasonic treatment of holes in fragile materials. It has been shown that the traditional processing of holes by an ultrasonic method is based on the use of straight rods, in which the amplitudes of displacements on the working – free end corresponds to the value of displacements at the point of its attachment to the ultrasonic oscillation concentrator. Supplementing the configuration of a straight rod with a curvilinear shape in the form of a circular arc or a spiral twisted by one turn will allow obtaining additional displacements caused by the elastic properties of a section with a curved shape. The paper considers several calculated schemes of a curvilinear rod bounded by angles j equal to p/2, p and 2p, fferent direction of the external force action. The obtained results have shown that an increase in the circular arc angle leads to a corresponding increase in the elastic displacement index of the rod free end. In this case, the total displacements of the rod free end will be made from displacements caused by vibrations of the acoustic system and the displacements of a curved thin rod from an external force. Calculations have established that the magnitude of the elastic displacements of curved rods is influenced by the shape and magnitude of the angle, the direction of the external force, the radius of curvature, the rigidity of the cross section. The considered schemes of thin rods with curvilinear sections can find practical application in ultrasonic oscillatory systems for processing small-diameter holes in fragile materials. This increases the intensity of tool oscillations and improves the process performance.

Методом формы осциллирующей капли исследованы адсорбционные и дилатационные реологические характеристики (модуль упругости и вязкости) лактата хитозана на границе раздела жидкость - газ. Определены зависимости динамического и равновесного поверхностного натяжения от концентрации лактата хитозана в растворе. Установлено, что полученные зависимости сходны с таковыми для поверхностноактивных высокомолекулярных соединений. Изучены зависимости поверхностных упругости и вязкости лактата хитозана от частоты осцилляций и концентрации. Показано, что лактат хитозана способен образовывать упругие адсорбционные слои со значениями модуля вязкоупругости сопоставимыми для биополимеров белковой природы. The adsorption and dilatational rheological characteristics (the elasticity and viscosity modulus) of chitosan lactate at the liquid-gas interface are investigated by the oscillating drop shape method. The dependences of the dynamic and equilibrium surface tension on the concentration of chitosan lactate in solution have been determined. It was found that the dependences obtained are similar to those for surface-active high-molecular weight compounds. The dependences of the surface elasticity and viscosity of chitosan lactate on the oscillation frequency and concentration have been studied. It has been shown that chitosan lactate is capable of forming elastic adsorption layers with the values of the viscoelastic modulus comparable to that of protein biopolymers.

Bstract. Aim is to determine the Frank elastic constants of an erbium-based liquid crystal complex. Methodology. The orienting effect of a magnetic field on an erbium-based liquid crystal complex was studied by a capacitive method. The dependence of the effective values of the components of the dielectric permittivity of the complex on the magnetic field is obtained. A theoretical approach and a numerical method for determining the Frank elastic constants are proposed based on the experimental dependence of the effective values of the permittivity of a cell on a magnetic field. Results. The dependences of the permittivity of the sample on the applied magnetic field explained, and Frank elastic constants for this substance are found. Research implications. Paramagnetic nematic liquid crystal complexes based on lanthanide ions (lanthanide mesogens) possess highly efficient luminescence and anisotropy of magnetic susceptibility is anomalously large for liquid crystals. The indicated properties of nematic lanthanide mesogens make it possible to create optical media with linearly polarized luminescence for use in optoelectronic devices controlled by electric and magnetic fields.

Objectives. Development of a model and carrying out numerical calculations for the cooling of thin jets of Hydrogen and Deuterium as applicable to installations on receiving cryogenic monodisperse targets.Methods. To achieve this purpose, the model of cryogenic jet outflow into the low pressure area was created and using PHOENICS software the temperature change of the surface and the interior of a jet over time for various external parameters is investigated through the numerical method.Result. The dependences of temperature changes of liquid Hydrogen and Deuterium jets along the jet surface and along the radius depending on the jet diameter, speed, initial jet temperature and pressure in the working chamber of installations for receiving cryogenic monodisperse targets were carried out.Conclusion. The principal possibility of creating high-speed cryogenic monodisperse targets is shown. According to the calculations, at input of thin liquid jets of Hydrogen or Deuterium with a speed up to 100 m/s into the working chamber with low pressure, jets at a distance of up to 1 mm do not have time to freeze and can be broken into monodisperse drops. Drops are cooled due to evaporation and become granules. The developed model, the program for determination of parameters of steady monodisperse disintegration of liquid cryogenic streams and results of numerical calculations can be used during creation of units for receiving high-speed cryogenic monodisperse targets.

The shielding characteristics of hydrophilic polymer, which is a crosslinked polyelectrolyte hydrogels and used for developing of flexible modules for electromagnetic radiation shields, are studied.

By the method of capillary viscosimetry, the melt flow curves of the molded phenolic resin and its compositions with lubricant, plasticizer and their mixture were obtained. It was shown that the size (diameter) of the capillary channel influences the dependence of the effective shear rate on the shear stress (flow curves) of the studied compositions. Such rheological behavior of the compositions during flow is associated with the effect of sliding along the surface of the capillary wall. According to the Mooney method, the dependences of the effective shear rate at given values of shear stress on the reciprocal of the capillary radius are plotted. The function of the slip velocity on the shear stress on the capillary wall is characterized in terms of the slip coefficient, which relates the shear stress on the capillary wall to the velocity of the composition along it. For the studied compositions, the total flow through the capillary was divided into volume fractions, one of which is associated with a shear flow; the other is determined by the slip effect. It has been shown that the introduction of both a lubricant and a plasticizer into the composition leads to an increase in the fluidity of the compositions. At the same time, adding of lubricant increases the volume fraction of the slip flow. The greatest effect of increasing the fluidity of the composition gives the use of complex modifying additives containing both lubricant and plasticizer.

We consider the effect of the disjoining pressure on the critical conditions for the realization of the instability of a charged liquid surface. The evolution of the surface of a charged layer of liquid is theoretically analyzed. In addition, it is proved that when the thickness of the liquid layer on a solid substrate is reduced to a value on the order of 100 nm, the effect of the disjoining pressure becomes very significant.

The shear dynamics and features of behaviour of liquid crystals in external magnetic and electric fields are investigated. The relations which determine the shear impedance and the effective viscosity coefficient of spatially inhomogeneous liquid crystals are obtained. The efficiency of shear waves and flows in external fields for experimental study of liquid crystals is discussed.

In this paper we have obtained polarization and dispersion corrections to the interfacial energy of the faces at the boundary between calcium and barium crystals of low-temperature modifications and nonpolar organic liquids using the electron-statistical method. We have shown orientation dependence of the corrections and interfacial energy of the crystals in view of polarization and dispersion corrections.

the paper analyzes the results of research in the field of polymer coatings and nanocarbon Components, in connection with which it was hypothesized that the modification of polymer coatings with fullerenes can improve their physical-mechanical properties and performance characteristics

The aim of the study is to create a methodology for calculating the equal strength of structural elements of composite reinforcement in tension and transverse shear and to develop recommendations for conducting tests to determine the mechanical properties in tension. In theoretical studies, design schemes were compiled and a comparative structural and mechanical analysis of composite reinforcement was performed according to the criteria for strength at break of the rod, as well as shear strength of its polymer shell. It is shown that the main contribution during the tests is made by the transverse shear strength of the polymer shell in special couplings for gripping the samples, as well as the alignment of the samples and couplings during the tests. Recommendations are given on calculating the minimum required coupling length and on ensuring alignment of samples and couplings.

The dependence of the shear viscosity of spherical particles suspension on the volume fraction is analyzed. Existing experimental works on modeling the behavior of a suspension of solid spherical particles show incomplete agreement between the data obtained. This is because it is quite difficult to exclude various factors that affect the viscosity of the suspension. It is rather difficult to obtain particles which shape is closest to spherical. Eliminating all types of interactions inherent in colloidal systems is also a difficult task. However, it can be assumed that the form of the dependence of the shear viscosity of the suspension on the volume fraction of particles has a certain shape typical of a suspension of hard spheres.The entire range of volume fraction changes from 0 to 0.64 is considered. An estimate of the region of variation in the volume fraction of the dispersed phase is proposed, at which hydrodynamic interactions can be ignored. It is shown that the range of applicability of the Einstein model of shear viscosity of an infinitely diluted suspension is much narrower than previously thought. Thus, checking the adequacy of the Einstein formula leads to significant technical difficulties.Cell models are widely used to describe the shear viscosity behavior of concentrated colloidal systems. In this case, one of two cell models describing a suspension of solid spherical particles is selected as the basis. A relationship between the volume fraction of suspension particles and the internal parameter of cell models, which characterizes the degree of interparticle hydrodynamic interaction, is obtained. It was shown that 1) these models themselves do not adequately describe the experimental data; 2) the choice of the internal parameter in both models is not consistent with the geometry of the system; 3) if we choose the internal parameter of the system adequately to the geometry, then the results do not agree with the experimental data even at a qualitative level., Проведен анализ зависимости сдвиговой вязкости суспензии сферических частиц от их объемной доли. Рассмотрены случаи бесконечно разбавленных, полуразбавленных и концентрированных суспензий. Предложена оценка значений концентрации частиц суспензии, при которой можно не учитывать вклад от гидродинамических взаимодействий. Получена связь между объемной долей частиц суспензии и внутренним параметром ячеечных моделей, который характеризует степень межчастичного гидродинамического взаимодействия, Проведений аналіз залежності зсувної в'язкості суспензії сферичних частинок від їх об'ємної долі. Існуючі експериментальні роботи по моделюванню поведінки суспензії твердих сферичних частинок показують не повну узгодженість отриманих даних між собою. Це пояснюється тим, що виключити різні чинники, що роблять вплив на в'язкість суспензії досить складно. Отримати частинки, форма яких найбільш наближена до сферичної досить важко. Виключити всі види взаємодій властиві колоїдним системам також є складним завданням. Проте можна вважати, що вигляд залежності зсувної в'язкості суспензії від об'ємної долі частинок має певну форму, характерну для суспензії твердих сферичних частинок між якими існують лише гідродинамічні взаємодії.Розглянутий весь інтервал зміни об'ємної долі від 0 до 0.64. Запропонована оцінка області зміни об'ємної долі дисперсної фази, при якій можна не враховувати гідродинамічні взаємодії. Показано, що область застосування моделі Айнштайна зсувної в'язкості нескінченно розбавленої суспензії набагато вужча, ніж вважалося раніше. Таким чином, перевірка адекватності формули Айнштайна приводить до значних технічних складнощів.Для опису поведінки зсувної в'язкості концентрованих колоїдних систем широко використовують коміркові моделі. При цьому за основу вибирають одну з двох коміркових моделей, що описують суспензію твердих сферичних частинок. В роботі отриманий зв'язок між об'ємною долею частинок суспензії і внутрішнім параметром коміркових моделей, який характеризує міру міжчасткової гідродинамічної взаємодії. Показано, що 1) самі ці моделі не цілком адекватно описують експериментальні дані; 2) вибір внутрішнього параметра в обох моделях не узгоджується з геометрією системи; 3) якщо вибрати внутрішній параметр системи адекватно геометрії, то результати не узгоджуються з експериментальними даними навіть на якісному рівні.

Alkali-alumina-borate glass-ceramics doped with Cr3+ ions are successfully synthesized by the melt quenching technique with variable annealing time. The optical and luminescent properties of glass-ceramics were investigated in detail.

The study of the karbotitanosianirovanie process in multycompounds melt salts, in radio-frequency electromagnetic field was considered. At was shown the possibility of checking of "diligences" melt salts by means of acoustic emission experimental method.

The problem on pressure distribution in the bulk material of the round silo with allowance for viscous fluid with dry internal friction is considered.

The interfacial energy of uranium boundary with alkali and alkaline-earth metals has been estimated by the electron-statistical method. It has been shown that alkali and alkaline-earth metals are strong surfactants relative to uranium. Formulas for polarization correction, external and temperature terms, have been obtained which take into account change of density at the contact boundary. The temperature contribution in the interfacial energy of crystal faces of three allotropic modification of uranium has been estimated. The influence of s-metal melts on the profile of electron density has been analysed.

The contribution of the dispersion interaction into the interfacial energy of lithium and sodium BCC-crystals has been found on the boundaries with non-polar organic liquids on the grounds of the electron-statistical method as well as the E.M. Lifshits theory.

The matter of thermal conductivity is considered in an approximation, in which the free length of phonons is limited and doesn't depend on temperature, so that the temperature behavior of thermal conductivity coefficient is only determined by thermal capacity. In these conditions the problem of non-stationary thermal conductivity of chain structures at low temperatures (T<

We developed a modified version of the electron - statistical method of calculation of the temperature contribution to the interfacial energy of the metal on the boundary with non-polar organic liquids. The dependence of the temperature contribution to the interfacial energy of Sc , α- Ti and α- Co metal on the orientation of the crystal and the dielectric permeability of the liquid has been obtained.

Oxide glasses were obtained by high-speed melt quenching. The glass ceramic samples were prepared by thermal crystallization method in reducing atmosphere. The phase composition and magnetic characteristics of the glass-containing Sr2FeMoO3 are investigated.

This paper continues the author’s series of works on the modeling of one-sided surfaces. There is a closed curve (disorienting contour) on a one-sided surface, and this curve has the property of changing the sign when it is bypassed local orientation in tangent space. A one-sided surface is a Klein bottle. Two smooth vector functions are considered. It is assumed that one of them is 2 pi — periodic, the other is 2 pi — antiperiodic. The Klein bottle equations, disorienting contours, and the equations of two Mobius sheets into which a Klein bottle is cut are determined using the obtained functions. In this paper, the inversion of the Klein bottle is investigated. We prove that if a Klein bottle does not pass through the center of inversion, then the inversion of the Klein bottle is also the Klein bottle. It is also proved that if the Klein bottle does not pass through the center of inversion, then the disorienting contours of the Klein bottle under the inversion will pass into the disorienting contours. Models of the considered surfaces are built with the help of the computer mathematics system., Данная публикация продолжает серию работ автора о моделировании односторонних поверхностей. На односторонней поверхности существует замкнутая кривая (дезориентирующий контур), обладающая тем свойством, что при обходе локальная ориентация в касательном пространстве меняет знак. Односторонней поверхностью является бутылка Клейна. Рассматриваются две гладкие вектор-функции. Предполагается, что одна из них есть 2π периодическая, другая 2π — антипериодическая. С использованием найденных функций определяются уравнения бутылки Клейна, дезориентирующие контуры и уравнения двух листов Мебиуса, на которые разрезается бутылка Клейна. В работе исследуется инверсия бутылки Клейна. Доказывается, что если бутылка Клейна не проходит через центр инверсии, то инверсия бутылки Клейна есть бутылка Клейна. Доказывается также, что если бутылка Клейна не проходит через центр инверсии, то дезориентирующие контуры бутылки Клейна при инверсии перейдут в дезориентирующие контуры. С помощью системы компьютерной математики строятся исследуемые поверхности.

Analytically, in a linear approach on the dimensionless amplitude of capillary waves on the charged surface of a layer of a viscous conducive liquid on a metal wire, the dispersive equation is derived. It is shown that the wire exerts the stabilizing influence on capillary waves. The influence of a wire becomes essential only at great values of its radius. Emergence of an electric charge on a layer of the liquid leads to complication of a range of the implemented movements of the liquid and to a quantitative change of values of frequencies, increments, and decrements.

Questions on the definition of shear force in the slope of the cross section., Рассмотрены вопросы по определению поперечной силы в наклоном сечении., Розглянуто питання щодо визначення поперечної сили в нахилом перетині.

In this paper, we investigate the dispersions of magnetic polymers by molec-ular dynamics method. We considered four types of magnetic polymers: chain, ring, X- and Y-structures. We have studied the behavior of the initial magnetic susceptibility and con-ducted cluster analysis to obtain full information about the structural properties of magnetic polymers in the systems under study.

This paper is devoted to the study of the polydispersity effect on the self-assembly of supramolecular magnetic polymers. With the help of Langevin dynamics simu-lations we study the various structure parameters of a single magnetic polymer of different conformations: closed ring, X-shaped and Y-shaped.

Liquidity planning or forecasting is a complex, complicated by uncertainty and a large number of unknown parameters task. Economical agents solve this problem using various methods and processes to manage liquidity. The article describes a liquidity forecasting process, use of financial modelling, and a method to forecast company’s liquidity via Monte-Carlo modelling.

The method to calculate the interfacial energy on the boundary with non-polar organic liquids has been developed within the electron-statistical theory. The dependence of interfacial energy of faces of alkali metal crystals bounding to hexane on the atomic number of the element has been obtained. The anisotropy of the interfacial energy has been found.

Analysis of characteristics of relaxation processes of vitrification and their known phenomenological descriptions was done. A detailed examination of the microscopic description of vitrification and nature of atomic dynamics in glassy materials led the author to the conclusion that physical-chemical functions of fractional exponents, widely used for the spectrum of structural relaxation times.

A comparison of the solubility line and the metastability boundary in aqueous solutions have been carried out on the basis of the salt dimensional factors. It is shown that these solution parameters and other ones are changed non-monotonically due to the ionic radii increasing for iso- valence salt groups. It is observed the salt taxonomy on the characteristic subgroups of ideal and non- ideal electrolytes.

The problems of constructing of large-scale model of composites based on polymers and aluminosilicate nanotubes have been considered.

Purpose. Coefficient of rolling friction in bearings determines the amount of resistance to rotation of rope drums of the lifting mechanisms of transporting machines, which affects the value of the efficiency of such machines and their dynamics accordingly. To clarify the values of the efficiency and the speed of cargo, it is necessary to determine analytically the amount of rolling friction coefficient for the ball bearings of the lifting mechanism drum, reduced to a pin, and also to evaluate its influence on the dynamics of such a mechanism. Methodology. In the paper, dependences are given for determining the coefficient of resistance of the ball bearing of the cable drum of the lifting mechanism when it is rotated by both the inner and outer cages, as well as the design schemes of the bearing and drum. Findings. According to the results of research the dependences for definition of cargo movement speed and efficiency of the lifting mechanism of transporting cars with the specified value of movement resistance coefficient are presented. The corresponding graphical dependencies for a concrete example are constructed. Analysis of the obtained dependencies and graphs allows us to draw the following conclusions: 1) the rate of lowering the load depends on the position of the rope along the length of the drum, decreasing as it approaches its middle; 2) the coefficient of friction of the bearings of the drum reduced to the pin increases as the rope approaches the middle of the drum; 3) the efficiency of the rope drum depends on the position of the rope on the drum, decreasing as the rope approaches the middle of the drum; 4) the efficiency of the bearing depends on whether the holder rotates: internal or external, and the difference depends on both the load on the bearing and the lubricant, reaching more than 3% in its absence and 2% - with liquid lubrication. Originality. The authors obtained more accurate dependences of the lifting speed of the load and the efficiency of the lifting mechanisms, using, in this case, the dependences determined by the drag coefficient in the drum bearings. Practical value. The obtained values of resistances can be used for refined calculations of the lifting mechanisms of transporting machines., Цель. Коэффициент трения качения в подшипниках определяет величину сопротивления вращению канатных барабанов механизмов подъема транспортирующих машин, что влияет на значение коэффициента полезного действия таких машин и, соответственно, на их динамику. Для уточнения величин коэффициента полезного действия (КПД) и скорости движения груза в работе необходимо аналитическим способом определить величину приведенного к цапфе коэффициента трения качения для шариковых подшипников барабана механизма подъема, а также оценить его влияние на динамику такого механизма. Методика. В работе применяются зависимости для определения коэффициента сопротивления шарикового подшипника канатного барабана механизма подъема при вращении его как внутренней, так и наружной обойм, а также расчетные схемы подшипника и барабана. Результаты. По итогам исследований приведены зависимости для определения скорости движения груза и коэффициента полезного действия механизма подъема транспортирующих машин с уточненным значением коэффициента сопротивления движению. Построены соответствующие графические зависимости для конкретного примера. Анализ полученных зависимостей и графиков позволяет сделать следующие выводы: 1) скорость опускания груза зависит от положения каната по длине барабана, уменьшаясь при приближении к середине; 2) приведенный к цапфе коэффициент трения подшипников барабана увеличивается с приближением каната к середине барабана; 3) КПД канатного барабана зависит от положения каната на барабане, уменьшаясь с приближением каната к середине барабана; 4) КПД подшипника зависит от того, какая обойма вращается: внутренняя или наружная, и разница зависит как от нагрузки на подшипник, так и от смазки, достигая более 3 % при ее отсутствии и 2 % – при жидкой смазке. Научная новизна. Авторы получили уточненные зависимости скорости подъема груза и КПД механизмов подъема, используя при этом зависимости по определению коэффициента сопротивления движения в подшипниках барабана. Практическая значимость. Полученные значения сопротивлений могут быть применены для уточненных расчетов механизмов подъема транспортирующих машин., Мета. Коефіцієнт тертя кочення в підшипниках визначає величину опору обертанню канатних барабанів механізмів підйому транспортуючих машин, що впливає на значення коефіцієнта корисної дії (ККД) таких машин та, відповідно, на їх динаміку. Для уточнення величин коефіцієнта корисної дії та швидкості руху вантажу необхідно аналітичним способом визначити величину приведеного до цапфи коефіцієнта тертя кочення для кулькових підшипників барабана механізму підйому, а також оцінити його вплив на динаміку такого механізму. Методика. В роботі наводяться залежності для визначення коефіцієнта опору кулькового підшипника канатного барабана механізму підйому при обертанні його як внутрішньої, так і зовнішньої обойм, а також розрахункові схеми підшипника і барабана. Результати. В роботі наведені залежності для визначення швидкості руху вантажу і коефіцієнта корисної дії механізму підйому транспортуючих машин із уточненим значенням коефіцієнта опору руху. Побудовано відповідні графічні залежності для конкретного прикладу. Аналіз отриманих залежностей та графіків дозволяє зробити наступні висновки: 1) швидкість опускання вантажу залежить від положення каната по довжині барабана, зменшуючись при наближенні до середини; 2) приведений до цапфи коефіцієнт тертя підшипників барабана збільшується з наближенням каната до середини барабана; 3) ККД канатного барабана залежить від положення каната на барабані, зменшуючись із наближенням каната до середини барабана; 4) ККД підшипника залежить від того, яка обойма обертається: внутрішня або зовнішня, і різниця залежить як від навантаження на підшипник, так і змащення, досягаючи більш 3 % при її відсутності та 2 % – при рідкому мастилі. Наукова новизна. Автори отримали уточнені залежності швидкості підйому вантажу і ККД механізмів підйому, використавши при цьому залежності по визначенню коефіцієнта опору руху в підшипниках барабана. Практична значимість. Отримані значення опорів можуть бути використані для уточнених розрахунків механізмів підйому транспортуючих машин.

The paper describes the features of films formation from glassy dielectric suspension on sapphire substrate by centrifugation. This method allows to obtain the glassy dielectric films with most uniform thickness and uniform coating of different compositions without the use of complex processes. It was found the set of parameters influencing on the roughness value for obtained glassy dielectric on sapphire. The technological route for glassy dielectric formation on sapphire substrate is presented. It can be the basis for the production of radiation-resistant elements for microelectronics. The glassy dielectric suspension solution was prepared initially for glass dielectric film obtaining on sapphire substrate. At the first stage it is necessary to grind glassy dielectric material to powder with specific surface of 5000 cm2 /g and then to add the isobutyl alcohol, and to grind glass powder with frequency of 1500 rpm for 24 hours in an agate drum. Technological route for junction formation of glassy dielectric and sapphire substrate for microelectronic components was developed. Putting the glassy dielectric material suspension on sapphire substrate is performed for 3-5 minutes with the rotational speed of the centrifuge of 7000 rpm. Drying uniformly inflicted glassy dielectric conducted in an oven at the temperature of 50–60 ° C for 3–5 min. High temperature annealing is carried out in a muffle furnace at T

The calculations of the parameters of the model of delocalized atoms for metallic glasses, where the fluctuation volume fg at the glass transition temperature is about fg  0.025-0.027, which is consistent with the data for amorphous organic polymers and other glassy systems.

The use of mesoporous silica nanoparticles doped with manganese dioxide produced by the physical method of electron beam evaporation for MRI-contrast.

Mutual solubility of components for binary interstitial solutions were calculated in static approximation. Temperature and concentration dependences for solubility were found. It was shown that the solubility obey the law of Arrhenius.

Dielectric properties of polymer materials based on epoxide oligomer and polyamine amide are studying. Via dielectric spectroscopy method it is proved that dipole groups orientation of epoxide polymer macromolecules fixed by third-dimensional grid and are carriers of thermoelectret charge occurs under polymer transition into electret state. Electret state of polymer matrix is characterized by a free state of epoxyamine macromolecules.

In this paper, by a low-temperature colloidal aqueous method, without the use of toxic media, the quantum dots of cadmium selenide in the shell of chitosan were synthesized. Chitosan was used as a matrix for the growth of colloidal semiconductor particles, and it also stabilized the obtained particles.The purpose of this work was studying the protective properties of chitosan in colloidal solutions of cadmium selenide quantum dots. The objective of the study was to analyze the protective effect of chitosan in colloidal systems by analyzing the optical and rheological properties of the obtained solutions.The dependence of the light transmission of colloidal solutions of cadmium selenide quantum dots in the shell of chitosan on the concentration of polysaccharide was investigated.It has been established that the light transmission of colloidal solutions decreases with time, the lower the content of chitosan in solution, which indicates that the protective action of colloidal solutions of quantum dots of cadmium selenide increases with increasing concentration of the polysaccharide.A study was made of the kinematic viscosity of the obtained solutions with different concentrations of chitosan in time. It was established that when the quantum dots are formed in the chitosan matrix, the viscosity of the colloidal system decreases. The protective effect of chitosan increases with increasing concentration in the solution., В данной работе низкотемпературным коллоидным водным способом без использования токсичных сред был проведен синтез квантовых точек селенида кадмия в оболочке хитозана. Хитозан выступал в качестве матрицы для роста коллоидных частиц полупроводника, а также стабилизировал полученные частицы.Целью настоящей работы было исследование защитных свойств хитозана в коллоидных растворах квантовых точек селенида кадмия. Задача исследования – путем анализа оптических и реологических свойств полученных растворов проанализировать защитное действие хитозана в коллоидных системах.Исследовали зависимость величины светопропускания коллоидных растворов квантовых точек селенида кадмия в оболочке хитозана от концентрации полисахарида.Установлено, что величина светопропускания коллоидных растворов со временем уменьшается тем быстрее, чем меньше содержание хитозана в растворе, что свидетельствует о том, что с ростом концентрации полисахарида его защитное действие в коллоидных растворах квантовых точек селенида кадмия увеличивается.Провели исследование кинематической вязкости полученных растворов разной концентрации хитозана во времени. Установили, что при формировании квантовых точек в матрице хитозана вязкость коллоидной системы падает. Защитное же действие хитозана растет с увеличением его концентрации в растворе.

The paper considers a problem of falling the partially wetting liquid across solid surface taking into account the disjoining pressure for liquid particles in its thin layers close to the three phase contact line. Within the frame of dropping liquid hydrodynamics it is easy to take into consideration the surface tension. On the other hand, with available surface tension, the attempts to fulfill Yung condition for a contact angle encounter truly insurmountable difficulties. Generally speaking, this problem has no solution within the limits of standard hydrodynamic theory of viscous liquid if the surface tension occurs and, at the same time, it is necessary to fulfill Yung condition for partial wetting. These problems can be solved if, instead of Yung condition, which is specified on the three phase contact line, the task is reformulated taking into account an additional chemical potential (or, in other words, the disjoining pressure) of the liquid particles in thin liquid layers close to the three-phase contact line. This approach allows us to formulate the appropriate problem of mathematical physics in the consistent closed-form. The unique dependence of the disjoining pressure on the liquid film thickness and the decline angle of the free surface leads to degeneration of hydrodynamics equations on the three phase contact line, on the one hand, and to fulfilling the Yung condition, on the other one. The paper demonstrates application of the developed theory in the context of calculating liquid surface form at different movement velocities. The asymptotic relationships obtained from the results of numerical experiments allow us to describe the variation law of the apparent 'dynamic' contact angle versus rate of the falling liquid from the wetted surface in the way suitable for calculations.

The paper proposes an approximate method to calculate the melting time of the sludge-like cryogenic product in horizontal cylindrical tank with spherical bottoms during drainage storage. The problem to find where there is the liquid - clean slush interface taking into account the heat flows from the walls and the area of clean liquid. It is assumed that the area of sludge is isothermal and has a melting point of solids, sludge - clean liquid interface is flat, free surface of the liquid is stationary and has a saturation temperature at a given pressure. The temperature in the clean liquid is distributed linearly. These approximate relationships allow us to estimate the melting time of the sludge-like cryogenic product in tank without detailed calculation of temperature fields in clean liquid.

For the first time, the acoustic emission (AE) method applicability to study the processes ongoing in the microporous medium under capillary pore filling with liquid is investigated. In particular, the temperature contribution to the dynamics of the porous materials impregnation is studied. The experimental results have shown that the most informative AE parameters reflecting the capillary liquid rise dynamics are the signal sum and the oscillation sum. The curve shape of the signal sum dependence on the AE amount follows the curve shape of the dynamic pattern of changing in the liquid elevation through the capillaries of the ceramic sample constructed from the experimental data. At the beginning of the capillary rise, the AE activity is significantly higher at higher temperatures. With increase of the liquid capillary rise, the process intensity decreases. The experimental data indicate that the AE parameters reflect the impregnation dynamics and kinetics under any change in the impregnation conditions, and they can be used for the remote process control.

The paper considers characteristic points on the Joule-Thomson curve: the inversion temperature, the maximum point in P, T-coordinates, the point of intersection with the critical isochore, the ideal gas curve, and the binodal of the liquid. The coordinates of these points and the possibility of using them for constructing the equation of a curve are discussed., Рассмотрены характерные точки на кривой Джоуля-Томсона: температура инверсии, точка максимума в P, T-координатах, точки пересечения с критической изохорой, кривой идеального газа, бинодалью жидкости. Обсуждаются координаты этих точек и возможность использования их для построения уравнения кривой., Розглянуто характерні точки на кривій Джоуля-Томсона: температура інверсії, точка максимуму в P, T-координатах, точки перетину з критичною ізохорою, кривою ідеального газу, бінодал’ю рідини. Обговорюються координати цих точок і можливість використання їх для побудови рівняння кривої.

Results of the development of electromagnetic shielding glass compositions for protection against electromagnetic radiation are given in this work.

A classification of amphiphilic monomers based on the partitioning properties was performed. Partition coefficients were calculated for six amine-containing (meth)acrylamides. Dependence of the partition coefficient on a monomer structure was shown.

The comparative study of change of surface tension of solutions of some commercial rubbers before and after thermal ageing technique du-Nui, analyzed the features of change of surface tension of solutions of various rubbers in the presence of a mixture of fullerenes. Calculations of the Gibbs energy and the analysis of the obtained data to predict the behavior of polymer systems when changes are made to mix of fullerenes in a wide concentration range. When comparing the results of changes in Gibbs energy and the surface tension in fluids rubbers shown that mentioned above in solutions of elastomers aged, than the control. This fact confirms the initial chapeau of physic-chemical interactions of molecules fullerenes by segments of the Kuna and end groups of the polymer chains, as it is known that when thermal-oxidative degradation of rubbers, respectively the number of segments of the Kuna and branched loose ends of macromolecules that are free to react with fullerenes in solution, free from spatial constraints. A comparative analysis of the interaction of rubbers with different chemical composition with double branches has shown that it is easier to just react and has minimum energy polibutadien interaction that has to do with lack of branching and no radicals in its structure and in the backbone chain. The maximum energy of interaction with Fullerenes have SBS rubber because it has large styrene blocks in the main polymer chain that causes the spatial constraints to direct contact with fullerene molecules, you can assume that the interaction is only low-molecular fraction of Fullerenes mixture, possessing the necessary dimensions. As a result of the study shows that the application of the method of separation ring (Du-Nui) allows you to predict the properties of rubber with modified nanomaterial’s with minimal labor costs.

The theory of heat stress for viscoelastic bodies based on linear rheological models of Maxwell and Kelvin for infinite domain bounded from inside by surfaces of either flat or cylindrical, or spherical shape together was examined. The influence of the geometrical factor and features of viscoelastic substances were found.

Summary. The irregular behavior of some kinds of suspensions on the basis of polymeric compositions and fine-dispersed fractions is characterized. As a simple, one-dimensional, shearing, viscometric flow such materials demonstrate the following mechanical behavior. There is no deformation if the shear stress does not exceed a certain critical value. If this critical value is exceeded, the flow is begins. This behavior is well-known and corresponds to the rheological models of viscoplastic fluid. However, further increase in the shear rate results in “solidification”. The rheological model of such viscoplastic fluids, mechanical behavior demonstrating the “solidification” effect is offered . This model contains four empirical parameters. The impact of the exponent on the dependence of the shearing stress and effective viscosity on the shear rate in the rheological model is graphically presented. The rheological model extrapolation on the three-dimensional flow is proposed.

We consider a method for determining the parameters of a rheological model of the fluid, which demonstrates the effect of “solidification”. Example on the use of the proposed algorithm is given.

Tumbling drums are widely applied in various mechanical engineering branches. The basic deficiency of such technological machines is high intensity of the sound radiation. In modern drums, quiet drives are applied. In practice, the excess of the sanitary noise code is created by the sound radiation of the drum body under the operating environment. The investigation of the dynamic interaction behavior of the environment and drum barrels is resulted. R – ε method of the media turbulence records is used in the present work. According to this approach, Navier-Stokes system of the equations and the continuity equation are used in describing the granular medium motion. The finite-element model geometry meets the form and the sizes of the CF1×18B tumbling drum. The drum axial symmetry has allowed constructing one half of its sectional elevation passing through the geometric centre. Medium energy flows affecting the drum barrels are defined for the calculated ambient velocities and normal velocity components on the boundaries, wall pressure. This data allows calculating theoretically the acoustic characteristics of the tumbling drums.

The article shows the possibility of using formal analogy of processes with restructuring of the original system to calculate the main parameters of self-dispersion: interfacial tension at the interface and the drops radius of the formed emulsion.

Based on the IR spectroscopy data and on the analysis of rheological characteristics of polypyrrole aqueous suspension stabilized with poly-(N-vinylpyrrolidone) we conjecture that a physical lattice composed with poly-(N-vinylpyrrolidone) is formed, where the lattice points are the polypyrrole chain aggregates interlaced with poly-(N-vinylpyrrolidone) chains. It was shown that there is a hydrogen bond between the constitutional repeating units of poly-(N-vinylpyrrolidone) and polypyrrole. It was determined that the size of the particles of the disperse phase decreases with the increase of poly-(N-vinylpyrrolidone) molecular weight. It was also determined that the size of particles increases with the increase of the mass fraction of polypyrrole aqueous suspension. It was shown that the disperse phase particles are rod-like, and the increase of molecular weight of poly-(N-vinylpyrrolidone) in an aqueous solution results in additional lengthwise stretching of particles. It was also shown that the viscosity of the stabilized poly-(N-vinylpyrrolidone) aqueous suspension follows the Einstein law.