Technical Physics最新文献

{"title":"Method for Determining Transport Coefficients in the Heat- and Mass-Transfer Equations for Multicomponent Media","authors":"I. V. Anisimova,&nbsp;V. S. Frolov","doi":"10.1134/S1063784225700021","DOIUrl":"10.1134/S1063784225700021","url":null,"abstract":"<p>A method is proposed for determining the transport characteristics used in the macroscopic heat- and mass-transfer equations for multicomponent media. The method has been based on the kinetic theory of gases. To generalize this theory to a multicomponent medium, its approximation by a basic binary medium has been used. In this study, a two-level approach has been developed, which combines the description of macroscopic processes in multicomponent gaseous media with the microscopic description based on the Boltzmann equation.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2706 - 2709"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Method of Adjusting the Amplitude–Frequency Characteristics of Filters","authors":"D. N. Novomeisky,&nbsp;M. N. Piganov,&nbsp;A. A. Luptsov","doi":"10.1134/S1063784224700968","DOIUrl":"10.1134/S1063784224700968","url":null,"abstract":"<p><i>Background</i>. The relevance of the topic of this work is due to the need to reduce the level of penetrating interference and improve the quality of the useful signal received by the on-board active interference station. <i>Goal.</i> Improving the quality and functional parameters of on-board frequency-selective systems and structures by adjusting the amplitude–frequency characteristics (AFCs) of filters. <i>Methods.</i> The system analysis of the main parameters, modeling of the frequency characteristics of attenuation and the standing wave voltage coefficient, expert assessments, and research tests have been used. <i>Materials.</i> To improve the characteristics of the filters, it is proposed to adjust (control) the AFCs of the filters. The schemes and topologies of correctors are given. It is shown that with the help of thin-film and thick-film correctors, various frequency response distortions can be eliminated, the slope of the characteristic can be adjusted, and the depth of the AFC dip can be changed. <i>Results.</i> The proposed schemes, designs, and topologies of correctors make it possible to adjust the slope of the characteristics up to 16 dB, change the depth of their dip, maintain the voltage standing wave ratio within 1.35–2.5 in the operating frequency range, reduce the frequency response nonuniformity to 0.2 dB, and the noise factor to 2.3–2.4 dB. To ensure such a level of performance during the adjustment process, it is required to carry out an individual combined adjustment of the resistors in the range from –10% to +30% or functional adjustment according to a template. At the same time, the flare discharge method provides a higher time stability of the frequency response adjustment indicators and a higher yield of suitable products as compared to the laser method. <i>Conclusions.</i> The proposed method of adjusting the AFCs of the filters in a frequency-selective system makes it possible to improve the quality of the useful signal received by the active interference station. Adjusting the frequency response by adjusting the resistances of the corrector resistors by the flare discharge method provides a higher temporal stability of the parameters than the laser adjustment.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2653 - 2661"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of the Molecular Characteristics of Polypropylene and Propylene–Ethylene Copolymers on Specific Heat Capacity","authors":"I. S. Larionov,&nbsp;D. A. Balkaev,&nbsp;L. M. Amirova","doi":"10.1134/S106378422570001X","DOIUrl":"10.1134/S106378422570001X","url":null,"abstract":"<p>The paper presents studies devoted to the study of the heat capacity of propylene homopolymers and propylene–ethylene copolymers, comparison of the data obtained with the composition of macromolecules and the molecular weight of polymers. The paper considers the influence of the molecular weight and ethylene groups on the specific heat capacities of polypropylenes, found by differential scanning calorimetry.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2715 - 2718"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Inorganic Nanomodifiers on the Properties of Photocurable Binders","authors":"V. S. Nikitin,&nbsp;K. A. Andrianova,&nbsp;L. M. Amirova","doi":"10.1134/S1063784224701068","DOIUrl":"10.1134/S1063784224701068","url":null,"abstract":"<p>The influence of montmorillonite on the polymerization and properties of photocurable resin has been investigated. It has been shown that montmorillonite added to the binder composition does not retard the curing reaction and does not suppress UV curing. Montmorillonite improves the elasticity modulus and does not influence the glass transition temperature of UV-cured compositions.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2649 - 2652"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feedback Control of Service Gates of a Shipping Lock Using a System of Rules","authors":"I. A. Danilushkin,&nbsp;S. A. Kolpashchikov,&nbsp;G. N. Rogachev","doi":"10.1134/S1063784224701020","DOIUrl":"10.1134/S1063784224701020","url":null,"abstract":"<p>The problem of positional control of the service gates in a shipping lock as a multidimensional control object with lumped parameters is considered. A general formulation of the problem is given, including requirements for the final and intermediate states. To solve the problem, it is proposed to use a production model of the regulator in the form of a system of rules. The numerical method for solving the problem is based on presenting the control algorithm in the form of an a priori non-fixed and time-varying system of rules determined during the control process. The presented results of numerical modeling confirm the effectiveness of the proposed method for determining the positional control of objects of this type.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2610 - 2615"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooling by a Dispersed Flow Performing a Phase Transition of a Modifies Surface","authors":"V. S. Shteling,&nbsp;A. T. Komov,&nbsp;P. P. Shcherbakov,&nbsp;A. V. Zakharenkov,&nbsp;A. P. Sliva","doi":"10.1134/S1063784224701019","DOIUrl":"10.1134/S1063784224701019","url":null,"abstract":"<p>Cooling of a modified surface by a dispersed flow of distilled water has been investigated experimentally, and the results have been compared with cooling of an unmodified surface. The modification of the heat-exchange surface of the copper working region has been performed by processing with a high-energy electron beam; as a result, a unique microporous surface has been obtained. The macrograph of the modified surface has been obtained and profiles have been measured using a profile meter. Four series of experiments for various heat carrier parameters have been performed for the modified and unmodified surfaces. The excess pressure of the heat carrier at the sprayer input was (4–14) × 10⁵ Pa, the mass flow rate of the heat carrier (distilled water) was (2.1–4.3) × 10^–3 kg/s, and the spraying density varied in the limits (3.0–6.1) kg/(m² s). The variations of the heat flux densities for these surfaces were compared. The convective component and the component of the phase transition of the removed heat flow during cooling the surface by a dispersed flow were estimated, and the conclusion was made concerning the key contribution of the phase transition to this process was made. The amount of evaporated liquid for the considered cooling modes were compared, and the dependence of this quantity on the heat flux density was obtained. The maximal heat flux density during the cooling of the surface by a dispersed flow attained 8.5 MW/m².</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2678 - 2683"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Numerical Solution in a Hemodynamic Model of the Cardiac Chamber","authors":"I. V. Anisimova","doi":"10.1134/S1063784225700033","DOIUrl":"10.1134/S1063784225700033","url":null,"abstract":"<p>The problem of hemodynamics (i.e., blood circulation in vessels resulting from the difference in the hydrostatic pressures in different parts of the circulatory system) has been investigated. For the differential problem in the hemodynamic model of heart, a difference scheme has been constructed and the convergence of the approximate solution to the exact solution has been substantiated. A numerical solution is obtained for the model problem of a single-chamber heart.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2710 - 2714"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of Electrophysical Characteristics of Nanofluids Based on Transformer Oil","authors":"S. M. Korobeynikov,&nbsp;V. E. Shevchenko,&nbsp;A. V. Ridel","doi":"10.1134/S1063784224701032","DOIUrl":"10.1134/S1063784224701032","url":null,"abstract":"<p>Several samples of nano-oil with different concentrations of dielectric and conductive nanoparticles are prepared to describe the electrophysical characteristics of nanofluids. Permittivity and conductivity of the nanofluids are experimentally measured. The processed experimental results are compared with the calculated results obtained using the Nielsen formula. The comparative analysis shows qualitative agreement of the calculated and experimental values of permittivity and a significant difference between the experimental and calculated dependences of conductivity on the concentration of particles. Such a difference between the calculated and experimental results is due to the adsorption of ions on the surface of the particles and their subsequent sedimentation. A decrease in the conductivity can be due to a decrease in the number of mobile particles and the fact that they have significantly less mobility compared to ions in the presence of weak electric fields. Additional measurements of the conductivity of nanofluids with particles of silicon dioxide and added oleic acid reproduce the observed decrease in the conductivity.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2632 - 2637"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of Supersonic Flows with Nonequilibrium Chemical Reactions","authors":"A. M. Molchanov,&nbsp;A. S. Myakochin,&nbsp;V. I. Panevin,&nbsp;S. Yu. Mesnyankin","doi":"10.1134/S1063784224700981","DOIUrl":"10.1134/S1063784224700981","url":null,"abstract":"<p>A new efficient implicit fully coupled numerical method for calculating thermochemical nonequilibrium flows is developed. Such flows are described by partial differential equations for conservation of mass, momentum, total energy, conservation of mass for each component, transfer of turbulent characteristics, etc. The total number of equations can be very large, which greatly complicates the solution of the general finite volume vector equation by using the standard fully implicit approach. The proposed method allows one to reduce operations with block tridiagonal matrices to inversion of 5 × 5 matrices and trivial operations of matrix multiplication. The numerical method is used to calculate the afterburning of the jet and for the supersonic combustion of hydrogen in the channel. The results show that for the considered problems, the new method is about two times more efficient than the standard fully implicit method.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2642 - 2648"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a Simulation Model of a Temperature Sensor under Critical Temperature and Sinusoidal Vibrations","authors":"E. A. Fokina,&nbsp;A. A. Trofimov,&nbsp;V. N. Ponomarev,&nbsp;S. A. Zdobnov","doi":"10.1134/S1063784224701093","DOIUrl":"10.1134/S1063784224701093","url":null,"abstract":"<p>Vibration measurement is among the most popular and cost-effective methods for diagnostics of the overall condition of equipment and is of undeniable importance in modern technology. Thanks to this process, manufacturers and consumers can be sure of the reliability and quality of technical systems, as well as prevent possible malfunctioning and failures. Vibration measurements in various fields confirm their versatility and importance in modern technical progress. The measurement of the effects of critical temperatures on a temperature sensor is aimed at determination of possible changes in the accuracy and reliability of the sensor. This will improve the quality of temperature measurement, eliminate inaccuracies and errors in operation of equipment, and increase the efficiency of the equipment under various operating conditions. The research method in this paper is a simulation model of the sensor, which is used to test for vibration and exposure to critical temperatures. Ansys and SolidWorks Simulation software are used to create the model to avoid costly and time-consuming test cycles. The results of the simulation modeling are used to construct diagrams of mechanical stress distribution under sinusoidal vibration and diagrams of temperature distribution under critical temperatures.</p>","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 11","pages":"2620 - 2625"},"PeriodicalIF":1.1,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}