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We prove that on each 2-step Carnot group with a corank 1 horizontal distribution two arbitrary points can be joined with a horizontal broken line consisting of at most 3 segments, while on every canonical 3-step Carnot group $ 𝔾 $ with a corank 2 horizontal distribution two arbitrary points can be joined with a horizontal broken line consisting of at most 7 segments. We show that two arbitrary points in the center of $ 𝔾 $ are joined by infinitely many horizontal broken lines with 4 segments. Here by a segment of a horizontal broken line we mean a segment of an integral line of some left-invariant horizontal vector field that is a linear combination of left-invariant horizontal basis vector fields of the Carnot group.

We consider sublimation in M–X (M = Mg, Cr, Sm, Eu; X = impurity with a preset activation energy for diffusion) model systems, for which the Peclet number Ре = wr/(ρD) (where D is the diffusion coefficient, w is the mass vaporization rate, ρ is the density of the substance, and r is a size factor) is calculated as a function of temperature by a semiempirical method. The Pe(T) temperature dependence is shown to exhibit complex behavior. Knowledge of the Peclet number as a function of temperature allows one to use it for calculating sublimation refining of a substance in the case of an impurity with a given separation factor and get an idea of how the sublimation refining process depends on temperature.

The article presents data on pathomorphological changes of the digestive organs in the associative course of heterakidosis and histomoniasis in turkeys. Changes in the liver were observed in 57.1% of cases: protein and fatty dystrophy, hepatocyte necrosis. The cеcal lesions were observed in 100% of cases, mainly fibrinous inflammation. In other parts of the intestinal tract – acute catarrhal inflammation.

Propagation was studied of the ionization front of the gas discharge sustained by the microwave surface wave in a quartz tube filled with low-pressure air. In a wide pressure range, the characteristic propagation velocities of the discharge front were measured, as well as the parameters of the stationary plasma column. The experimental results obtained are in satisfactory agreement with the discharge propagation model based on the concept of nonlocal electron heating in the plasma resonance region. The electrodynamic characteristics of the discharge were studied and the electron density averaged over the cross section of the plasma column was measured. Based on the experimental measurements of the ionization and electron loss rates, the electric field distribution was estimated in the ionization front region.

The article shows endothelium-vascular effects on the roots of the spinal cord with the progression of pain as a result of compression of the epidural microvascular plexus. In 68 patients with chronic low back pain before and after treatment were determined mediators of endothelium-vascular and axonal injuries, such as NR2-antibodies to NMDA microvascular receptors and the expression of soluble adhesion molecules of vascular endothelium-1 (sVCAM-1) and soluble intercellular adhesion molecules-1 (sICAM-1). All patients with low back pain showed an increase in the NR2 titer of antibodies to NMDA receptors and sVCAM-1 and sICAM-1 expression before treatment and a decrease in these parameters after treatment, especially in patients in the 2nd observation group. Thus, pregabalin at a dose of 150 mg in combination therapy convincingly influenced the reduction of neurovascular mediators and blocked neuropathic pain.

Применяемый пылевозврат с горячего конца печи позволяет увеличить ее производительность в среднем на 8–10%. В результате исследования компонентного состава пыли, уносимой газами промышленных печей спекания, установлен факт отличия пыли 4 и 5 полей электрофильтров от исходной шихты и пыли с пылевой камеры повышенным содержанием щелочей, хлоридов и сульфатов, влияющих отрицательно на качество спека. Для повышения эффективности пыль электрофильтров предложено выводить из оборота печи и не смешивать ее с пылью пылевой камеры, а утилизировать отдельно по индивидуальной схеме, разделяя ее на фракции по полям электрофильтра.

Solid propellants are mature systems playing a key role for both launch and in-space applications. This central position has been gained through years of continuous development and three main pillars: (i) the availability of suitable binders providing high enough mechanical properties also in the case of high filler loads, (ii) the use of ammonium perchlorate (AP) as oxidizer, and (iii) the performance tailoring offered by metal fuels and, in particular, by Al. In spite of its suitable characteristics, and, in particular, of the favorably high oxygen balance, AP implies the presence of Cl in the solid propellant exhaust. A drawback of the AP-based solid propellants is the presence of a significant mass fraction of HCl in the exhaust products. Thermochemical equilibrium calculations identify nearly 20 wt% of HCl in the plume of solid rocket motors with AP loads in the range 65-70 wt% which is typically encountered in commercial system applications. The propulsion grade Al powder is typically micron-sized, with relatively high metal content favoring increased theoretical specific impulse values. The actual specific impulse of aluminized fuels is influenced by the presence of 2P-flow losses originated by the presence of condensed combustion products and by metal combustion process. Micron-sized Al combustion implies aggregation/agglomeration phenomena. Agglomerates are responsible for performance losses (incomplete metal combustion, kinetic and thermal lags in the expanding gaseous propellant). The aggregation/agglomeration process is affected by factors as the propellant composition and burning rate. Ammonium nitrate (AN) is a Cl-free candidate for AP substitution in solid propellants. This process is hindered by inherent difficulties: (i) AN is highly hygroscopic (this implies strict storage and handling conditions), (ii) AN features a reduced oxygen balance with respect to AP, (iii) pure AN is subject to crystalline-phase transitions at relatively low temperature (and this transformation is affected by humidity) [1], (iv) inherent combustion mechanism. A suitable method for the augmentation of AN thermal stability is the use of phase-stabilized AN (PSAN). Mitigation of the issues related to the combustion process of AN/PSAN can be obtained by metal fuels featuring enhanced reactivity and more prompt ignition/combustion, as nano-sized or activated Al-based powders. This work discusses recent results obtained in a collaboration program between the Space Propulsion Laboratory (SPLab) of Politecnico di Milano, Tomsk State University (TSU) and the Institute of Physics Strength and Material Science of the Siberian Branch of the Russian Academy of Sciences. The work focuses on the use of composite Al-Mg powders in AP-PSAN solid propellants. The use of a dual oxidizer is considered as a suitable strategy to limit the HCl emission from the propellant combustion, while the selection of an Al-Mg powder aims at enhancing the powder reactivity with respect to the conventional micron-sized Al [2]. Mechanically activated Al-Mg powders produced by different methods are considered. In the work two mechanical activation methods are considered. These procedures yield different particle morphologies with flakes vs. spheroidal particles. In addition to this, composite powder composition is changed varying the Mg mass fraction. The two composites considered in the study contains 30 wt% and 50 wt% Mg, respectively. The propellant burning behavior is assessed considering quasi-steady burning rate under different combustion chamber pressures, and burning surface visualizations.

Based on the analysis of the current legislation, the article analyzes demographic processes, norms and requirements necessary for population growth, as well as the most dangerous deviations from them for the development of Russian civilization, that is, deviations. The author identifies three periods in the history of natural population growth, two of which are depopulation (1992 - 2012, 2015 - present), and moderately positive (2013 - 2015), and also lists the factors influencing the increase in population. During the analysis of deviations from the favorable and desirable development of the processes of saving the population of the Russian Federation, the main reasons for the decline in fertility are identified, reserves of population growth are identified, the author's idea of ways to overcome depopulation of the population is formulated in terms of such a disastrous phenomenon as large-scale artificial termination of pregnancy, and the negative impact on the birth rate of the ban on abortions is revealed.

A possible influence of location of the effective Fermi level in the forbidden gap of the surface base region on dose rate sensitivity of bipolar integrated circuits was described. Also, it is shown, that the position of the effective Fermi level leads to different behavior of bipolar devices during post-irradiation annealing at enhanced temperature. Experimental tests on dose rate sensitive devices were provided and discussed.

Dependences of LM 111 voltage comparator input current on time during post-radiation annealing are investigated. The technique based on the Gummel- Poon model of a bipolar transistor for numerical simulation of the annealing process, taking into account the temperature drift of the radiation-sensitive parameter is presented.

This paper presents the results of measurement and calculation within an upgraded Zuber model of critical heat flux (CHF) during nucleate boiling in thin horizontal layers of liquid. The layer height was increased in regimes of developed nucleate boiling. The two-phase layer was foam with vapor columns ascending at the corners of a rectangular square lattice. In the calculations, the foam was considered as an isotropic homogeneous system. The model assumes that the diameter of the vapor columns and the critical Helmholtz instability wavelength are independent of the foam density and are determined by the length of the most dangerous Rayleigh--Taylor instability wavelength. The proposed model fits the CHF experimental data for boiling liquid and can explain the CHF decrease in solutions with addition of surfactants that increase foaming.

The scope of this research is the prediction of a cast billet surface temperature, which it will have in the rolling mill after the heating process. The main problem is that such a prediction is needed before the cast billet will really leave the furnace. In many cases, the boundary value problem of the heat transfer, particularly the differential equations of the transient heat conduction, is used to solve this problem. But in this research an alternative data-driven approach is proposed, which is based on a model of the dependence of the billet temperature on the retrospection of its heating in the continuous furnace. Such a model is developed as a result of the analysis of the data from the furnace control system. Such data from the real furnace were collected and stored in the data warehouse. Their exploratory analysis was conducted. All data were splitted into training, testing and validation subsets. As a part of this research, the regression model previously developed by the authors was also validated. It seemed to be overfitted (the error on the test set was significantly higher than the one on the training set). To overcome this disadvantage, an alternative method to develop the required data-based model is proposed by authors on the basis of the Boosting and Bagging algorithms. They belong to the machine learning field. As a result of the experiments with the bagging and boosting, the required model structure was chosen as a “Random Forest” with special class of the regression trees known as DART (Dropout Adaptive Regression Trees). Based on a significant number of experiments with that model, the two confidence intervals of the temperature prediction were found: 68 % and 95 % ones. The mean value of the temperature prediction error was estimated as ~ 9 °C for both the test and validation sets.

Application of the method of layer-by-layer selective laser sintering of a metal powder for depositing capillary-porous coatings with a prescribed porosity onto heat-releasing surfaces is considered. Implementation of this method in experimental investigations of the boiling process on modified surfaces allows broad-range variations of the main parameters of microstructured capillary-porous coatings and other three-dimensional structures: material, porosity, amplitude (height), thickness of the residual layer and wavelength of capillary-porous coatings, and size and shape of three-dimensional ordered microtextures. It is demonstrated that the use of this technology can increase the heat transfer coefficient the case of boiling on the surface with a capillary-porous coating by several times as compared to the uncoated surface.

The article describes two main approaches to assessing the thermal loading of friction pairs—experimental and theoretical for evaluating friction pairs in terms of the phenomenon of fading. Most of the kinetic energy of a car with ABS is extinguished due to friction in the braking mechanism. Overheating of the brake mechanism, namely, its friction pairs, leads to the occurrence of critical fading, accompanied by a sharp decrease in braking torque. Reducing the influence of this phenomenon is a very difficult task both from the point of view of taking into account the cost of the brake mechanism and its minimal complexity. The authors propose the use of cryogenic treatment of brake discs to reduce the influence of thermal stress on the occurrence of fading, as well as comparing the results of theoretical and experimental evaluation of friction pairs of the brake mechanism. Modern methods of calculating temperature values and obtaining experimental data have been applied, allowing one to increase the accuracy of thermal load estimation.

This study is to apply the Data Mining concept to process technological data, which are received from a field level of an industrial control system of a steel billet heating in a continuous furnace of a rolling-mill shop. The main scope of the study is to find a regression dependence of the steel billet temperature on a history of its heating in such a furnace. This paper describes: 1) the principles of data warehouse implementation to store values of signals obtained from a steel billets tracking system, 2) the chosen features (input variables, regressors) to solve the problem under consideration, such as temperature in all furnace zones and time of a steel billet heating in each of them, 3) the applied algorithms of data pre-processing and exploratory analysis. Then the results of research on various machine learning algorithms application to find the required dependence are presented. The best quality of approximation is achieved using a model, which is based on classification and regression trees. They are trained with the help of an extreme gradient boosting algorithm modification - DART. Obtained prediction accuracy is ~9°C.

The performance of the total ionizing dose sensor based on a bipolar transistor were researched in this work.

Surface electromagnetic waves (SEWs) on imperfect conductors proposed by A. Sommerfeld and J. Zenneck in the early 20th century have remained unrecognized by academic science for almost a hundred years due to a regrettable misunderstanding of theorists and unsolved radio communication problems. Recognition could have come much earlier if radiophysicists had been able to apply excitation of SEWs in the centimeter range of microwaves, generation of which became possible in the first half of the 20th century with development of radar. Radiophysical experiments on excitation of surface electromagnetic waves on conductors in the centimeter range of radio waves are presented. A method for selective excitation of SEWs is described. Its essence is that the space radio wave radiation is suppressed by screening while the SEW on the conductive strip is excited by isolated currents launched through a slit in the screen.

Background. The study deals with the pathophysiological changes in nervous tissue at spinal roots ischemia and the search for neurodegradation markers at the early stages of the pathological process for more effective treatment. The purpose of the study: to determine structural changes in lipid metabolism in spinal roots compression and their relationship to the vascular growth factor (VEGF-A) under the influence of pathogenetically oriented therapy. Materials and methods. Seventy-six patients with chronic spinal roots compression are divided into 2 groups. Patients in the first group (31 patients) received a complex therapy with pentoxifylline, whereas 45 patients in group 2 received melatonin C3 in addition to this therapy. Serotonin, VEGF-A indexes were studied, lipid oxidation status was evaluated by malonic dialdehyde content. Also, the rates of total cholesterol, high-density lipoprotein cholesterol, sphingomyelin, and glutathione peroxidase were assessed. Results. Before treatment, the patients were detected with an increase in malonic dialdehyde, IL-1β, IL-6 and TNF-α, which indicates the development of immune inflammation as a result of the release of free radicals and accumulation of neurotoxic substances and increased oxidative stress. There were also an increase of total cholesterol and VEGF-A, reduced high-density lipoprotein cholesterol, sphingomyelin, glutathione peroxidase and serotonin. The complex therapy added with pentoxifylline in combination with melatonin leads to the decrease in malonic dialdehyde, VEGF-A, proinflammatory interleukins and increase in total cholesterol, high-density lipoprotein cholesterol, sphingomyelin, glutathione peroxidase and serotonin. Thus, ele-vated levels of high-density lipoprotein cholesterol and sphingomyelin after treatment contributed to the ordering of the lipid bilayer of the neuron-vascular membranes and led to a more rapid recovery and reparation of the conductive function of spinal roots and prevented the development of radiculomyelopathy. Conclusions. Compression of spinal roots showed changes in the activity of VEGF-A, neurohormones, and exacerbation of immune inflammation, which caused damage to the vascular neuronal cells of the membranes of spinal roots and led to the accumulation of neurotoxic products that cause intraneural damage with development of radiculomyelopathy. The use of pentoxifylline in combination with melatonin led to normalization of the above indicators and resulted in faster restoration of the structure and function of the nervous tissue and prevented the formation of radiculomyelopathy., Актуальность. Исследование посвящено изучению патофизиологических изменений в нервной ткани при ишемии корешков спинного мозга (КСМ) и поиску маркеров нейродеструкции на ранних этапах развития патологического процесса с целью более эффективного лечения. Цель исследования — изучение структурных изменений в липидном обмене при компрессии КСМ и их взаимосвязь с васкулярным фактором роста (VEGF-А) под влиянием патогенетически направленной терапии. Материалы и методы. 76 больных с хронической компрессией корешков спинного мозга были разделены на 2 группы. Больные 1-й группы (31 пациент) получали комплексную терапию с пентоксифиллином, в то время как 45 пациентам 2-й группы в эту же терапию включали мелатонин-С3. Изучались показатели серотонина, активность VEGF-А, состояние окисления липидов оценивали по содержанию малонового диальдегида (МДА). Также изучались показатели общего холестерина (ОХС), холестерина липопротеинов высокой плотности (ХС ЛПВП), сфингомиелина и глутатионпероксидазы (ГП). Результаты. У больных до лечения отмечалось повышение МДА, ИЛ-1β, ИЛ-6 и ФНО-α, что свидетельствует о развитии иммунного воспаления в результате высвобождения свободных радикалов, накопления нейротоксических веществ и усиления оксидативного стресса. Также отмечались повышение содержания VEGF-А, снижение ОХС, ХС ЛПВП, сфингомиелина, ГП и серотонина. Включение в комплексную терапию пентоксифиллина в комбинации с мелатонином привело к снижению содержания МДА, VEGF-А, провоспалительных интерлейкинов и повышению ОХС, ХС ЛПВП, сфингомиелина, ГП, серотонина. Таким образом, повышение уровня ХС ЛПВП и сфингомиелина после лечения способствовало упорядочиванию структуры липидного бислоя нейрососудистых мембран, приводило к более быстрому восстановлению электропроводящей функции КСМ и предотвращало формирование радикуломиелопатии. Выводы. При компрессии КСМ отмечались изменения активности VEGF-А, нейрогормонов и обострение иммунного воспаления, что приводило к повреждению сосудисто-нейрональных мембран оболочек КСМ и способствовало накоплению нейротоксичных продуктов, которые обусловливают интраневральные повреждения с формированием радикуломиелопатии. Применение пентоксифиллина в комбинации с мелатонином способствовало нормализации вышеуказанных показателей, приводило к более быстрому восстановлению структуры и функции и предотвращало формирование радикуломиелопатии., Актуальність. Дослідження присвячене вивченню патофізіологічних змін у нервовій тканині при ішемії корінців спинного мозку (КСМ) та пошуку маркерів нейродеструкції на ранніх етапах розвитку патологічного процесу з метою більш ефективного лікування. Мета дослідження — визначення структурних змін у ліпідному обміні при компресії корінців спинного мозку та їх взаємозв’язок із васкулярним фактором росту (VEGF-А) під впливом патогенетично скерованої терапії. Матеріали та методи. 76 хворих із хронічною компресією КСМ розподілені на 2 групи. Хворі 1-ї групи (31 пацієнт) одержували комплексну терапію з пентоксифіліном, тоді як 45 хворим 2-ї групи до цієї терапії включали мелатонін-С3. Вивчались показники серотоніну, активність VEGF-А, стан окислення ліпідів оцінювали за вмістом малонового діальдегіду (МДА). Також вивчались показники загального холестерину (ЗХС), холестерину ліпопротеїнів високої щільності (ХС ЛПВЩ), сфінгомієліну та глутатіонпероксидази (ГП). Результати. У хворих до лікування відмічалось підвищення МДА, ІЛ-1β, ІЛ-6 та ФНП-α, що свідчить про перебіг імунного запалення в результаті вивільнення вільних радикалів, накопичення нейротоксичних речовин та підсилення оксидативного стресу. Також відмічались збільшення вмісту VEGF-А, зниження ЗХС, ХС ЛПВЩ, сфінгомієліну, ГП та серотоніну. Включення до комплексної терапії пентоксифіліну в комбінації з мелатоніном привело до зниження вмісту МДА, VEGF-А, прозапальних інтерлейкінів та підвищення ЗХС, ХС ЛПВЩ, сфінгомієліну, ГП і серотоніну. Таким чином, підвищення рівня ХС ЛПВЩ і сфінгомієліну після лікування сприяло упорядкуванню структури ліпідного бішару нейросудинних мембран, приводило до більш швидкого відновлення і репарації електропровідної функції КСМ та запобігало формуванню радікуломієлопатії. Висновки. При компресії КСМ відмічались зміни активності VEGF-А, нейрогормонів та загострення імунного запалення, що спричиняло пошкодження судинно-нейрональних клітин оболонок КСМ та спонукало накопиченню нейротоксичних продуктів, які зумовлюють інтраневральні пошкодження з формуванням радикуломієлопатії. Застосування пентоксифіліну з мелатоніном спонукало до нормалізації вищезазначених показників, приводило до більш швидкого відновлення структури та функції нервової тканини та запобігало формуванню радикуломієлопатії.

The possibilities of application of known models of domain structure to multiphase alloys are analyzed with the aim to assess the anisotropy constants and to search for magnetically uniaxial highly anisotropic phases. It is shown in what cases and how the standard models of domain structure may be applied to such alloys. Recommendations on the necessary amendments of the model to be applied to multiphase materials are given.

The results testing technique of the structural optimization of the relational databases founded on the effect leveling of the cache-system is considered. Its feasibility through the paths with object flat sharing is proved.

The problem of increasing the cache system efficiency using the adaptive vector control of the stoch a s tic hybrid caching algorithm is investigated. The mathematical model of the abstract one - level caching system permitting to describe the known replacement strategies, including those which use object sizes for calculating their cache rating, is considered. This model is used in the mathematical cache - system model with the controlled stochastic hybridiz ation of several basic caching algorithms. The adaptive co n trol scheme of the stochastic hybrid caching algorithm permitting to shorten ten times the adaptation time compared to the previously considered methods at the e x pense of abandoning the direct solution to the performanc e criterion maximization problem at the preceding route section is presented. The known replacement strategies with the description of their operation fundamentals are surveyed. The chosen investigative techniques and the performed methods structure are ch aracterized. The comparison r esults of the obtained replacement strat e gies productivity on the non - stationary routes composed of the quasi stationary sections o b tained on the base of 20/80 Zipf’s distribution law are presented.