Physical Principles Of Operation Research Articles

РАЗРАБОТКА МОДЕЛИ ФИЗИЧЕСКОГО ПРИНЦИПА ДЕЙСТВИЯ СИСТЕМЫ АВТОМАТИЧЕСКОГО РЕГУЛИРОВАНИЯ ПОДАЧИ ТОПЛИВА ДИЗЕЛЬНОГО ДВИГАТЕЛЯ

The article discusses the use of an engineering-physical method for automatically regulating fuel supply in a diesel engine at the stage of constructing a model of the physical principle of operation. The resulting model of the system allows us to display the movement of the working fluid in space and its physical interaction in time.

Building a Model of the Physical Principle of Operation of an Autonomous Locomotive with a Steam Power Unit

Building a Model of the Physical Principle of Operation of an Autonomous Locomotive with a Steam Power Unit

Mitochondria at the Nanoscale: Physics Meets Biology-What Does It Mean for Medicine?

Mitochondria are commonly perceived as "cellular power plants". Intriguingly, power conversion is not their only function. In the first part of this paper, we review the role of mitochondria in the evolution of eukaryotic organisms and in the regulation of the human body, specifically focusing on cancer and autism in relation to mitochondrial dysfunction. In the second part, we overview our previous works, revealing the physical principles of operation for proton-pumping complexes in the inner mitochondrial membrane. Our proposed simple models reveal the physical mechanisms of energy exchange. They can be further expanded to answer open questions about mitochondrial functions and the medical treatment of diseases associated with mitochondrial disorders.

A Systematic Approach to the Search for New Technical Solutions for Electronic Equipment at the Initial Stages of Design

A systematic approach is described to search for new technical solutions for radio-electronic units at the stage of technical proposal. It is based on the transformation of the electrical circuit of the device being developed into an object-oriented model reflecting its physical principle of operation. Operators for processing working signals are proposed, which allow choosing alternative technical implementations of fragments of electrical circuits for obtaining new technical solutions. At the same time, parameters are introduced to limit the applicability of operators as part of signal processing facilities to ensure the operability of the radio-electronic device. The proposed approach can be used in the development of new and modernization of existing computer-aided design systems of electronic equipment.

Manipulations of Electronic and Spin States in Co-Quantum Dot/WS2 Heterostructure on a Metal-Dielectric Composite Substrate by Controlling Interfacial Carriers.

Charge and spin are two intrinsic attributes of carriers governing almost all of the physical processes and operation principles in materials. Here, we demonstrate the manipulation of electronic and spin states in designed Co-quantum dot/WS2 (Co-QDs/WS2) heterostructures by employing a metal-dielectric composite substrate and via scanning tunneling microscope. By repeatedly scanning under a unipolar bias, switching the bias polarity, or applying a pulse through nonmagnetic or magnetic tips, the Co-QDs morphologies exhibit a regular and reproducible transformation between bright and dark dots. First-principles calculations reveal that these tunable characters are attributed to the variation of density of states and the transition of magnetic anisotropy energy induced by carrier accumulation. It also suggests that the metal-dielectric composite substrate is successful in creating the interfacial potential for carrier accumulation and realizes the electrically controllable modulations. These results will promote the exploration of electron-matter interactions in quantum systems and provide an innovative way to facilitate the development of spintronics.

Overview of Promising Solutions in Subsurface Sounding Equipment.

This overview analyzes current advances in the equipment for detecting various subsurface metal and metal-containing objects. Various metal detector types are discussed alongside their operation principles, properties, and capabilities. Following the analysis of conventional metal detectors, promising design and technical solutions are explored, implementing new physical metal detector operation principles that have not been used before for this equipment class. The information provided allows for evaluating new metal detector concepts developed to improve the sensitivity and accuracy of detecting equipment.

Высокоточный элементный анализ образцов горных пород и археологических артефактов методом рентгеновской фотоэлектронной спектроскопии

Introduction. Despite a fairly wide range of methods currently used for the chemical and elemental analysis of rocks and archaeological artifacts, many questions regarding the qualitative and quantitative accuracy of the analysis and the distribution of elements over the surface and volume of the sample with a high degree of locality remain open. In this regard, to solve these issues, in this work, for the first time, the method of X-ray photoelectron spectroscopy (XPS) was proposed and tested, which allows unambiguous and high-precision chemical identification of an object and the construction of its elemental map of the surface and volume. Materials and methods. The physical principles of the XPS method operation, which determine its record high qualitative and quantitative accuracy, are considered, a description of one of the most highly efficient X-ray photoelectron spectrometers Escalab 250 Xi, features of its operation and methods of adaptation for the study of rocks and archaeological artifacts are given. A special methodological advantage is the possibility of sample preparation and research under ultrapure conditions of ultrahigh vacuum. Results. XPS spectra were obtained in a wide range of photoelectron binding energies, which makes it possible to cover a fairly wide range of chemical elements that make up rocks and archaeological artifacts. With a high degree of spatial locality – at the level of 30 μm – elemental maps of the objects under study were built. Using the additional advantage of the method, based on the analysis of the energy position and the shape of the photoelectron spectral line, the chemical states of the elements that make up the samples were determined. Discussion. The obtained results of high-precision chemical analysis, combining both the general composition of the elements of the test sample as a whole and their spatial distribution with a high degree of locality, make it possible to achieve greater unambiguity in the identification of the objects under study compared to currently used analysis methods. Such high accuracy makes it possible to establish a correspondence between the composition of the rock and the archaeological artifact from the same area. The non-destructive nature of the XPS method, combined with ultrapure analysis conditions, makes it possible to ensure the safety of often unique objects. Conclusion. As a result of the study, it was shown that the XPS method can be quite effectively used for high-precision qualitative and quantitative analysis of rocks and archaeological artifacts, which is achieved both by the features of the method itself and by sample preparation and study of materials in ultrapure conditions of ultrahigh vacuum. The advantage of the method is the combination of a number of possibilities, such as not only the elemental, but also the chemical composition of objects, as well as the possibility of chemical mapping of the surface and analysis of the depth of the object with high spatial resolution. The research results can be used in solving a wide range of problems – from archeology to the development of mountainous areas, in particular, solving environmental problems by developing a scientific reserve for creating effective geochemical barriers. Further research should be focused on the development of techniques for adapting the XPS method to obtain three-dimensional tomographic models of the studied objects, which will improve the quality of their identification, in particular, from the point of view of geology and archeology.

Concept of Beam Instrumentation System for High-Intensity DARIA Proton Linac

Beam diagnostics is one of the main tasks during operation of charged particle accelerators. The paper presents a concept of a beam instrumentation system that provides diagnostic procedures and allows to measure and adjust the clue beam parameters in a linear resonant proton accelerator of a compact neutron source DARIA: current, position, profile, emittance, energy, phase characteristics. An important requirement is to provide measurements during the accelerator tuning procedure, when the beam parameters can be changed in a wide range. It is proposed to include in the main structure of the system such types of diagnostic devices as beam current transformers, stripline beam position monitors, wire scanners, ionization beam cross-section monitor, slit emittance meter, bunch shape monitor, water-cooled Faraday cup. A particular attention is paid to a non-destructive method due to a high pulse and average beam intensity in conjunction with a relatively low beam energy to provide continuous operational control of the beam parameters. Main physical principles of operation, typical characteristics, as well as features of the practical implementation of the devices are included. A possible arrangement layout of diagnostic units along the accelerator is proposed, taking into account peculiarities of using the proposed types of detectors in various parts of the accelerator.

Passive electrochemical hydrogen recombiner for hydrogen safety systems: prospects

This paper presents the concept of a passive electrochemical hydrogen recombiner (PEHR). The reaction energy of the recombination of hydrogen and oxygen is used as a source of electrical energy according to the operating principle for hydrogen fuel cells to establish forced circulation of the hydrogen mixture as an alternative to natural circulation (as is not utilized in conventional passive autocatalytic hydrogen recombiners currently used in nuclear power plants (NPPs)). The proposed concept of applying the physical operation principles of a PEHR based on a fuel cell simultaneously increases both productivity in terms of recombined hydrogen and the concentration threshold of flameless operation (the ‘ignition’ limit). Thus, it is possible to reliably ensure the hydrogen explosion safety of NPPs under all conditions, including beyond-design accidents. An experimental setup was assembled to test a laboratory sample of a membrane electrode assembly (MEA) at various hydrogen concentrations near the catalytic surfaces of the electrodes, and the corresponding current–voltage characteristics were recorded. The simplest MEA based on the Advent P1100W PBI membrane demonstrated stable performance (delivery of electrical power) over a wide range of hydrogen concentrations.

Anthropogenic emissions from coal-water slurry combustion: Influence of component composition and registration methods

The flue gas composition is often measured using a combination of techniques that differ in terms of both physical operation principle and type of output. Gas analyzers, FTIR spectrometers, and mass spectrometers are the most popular tools used for this purpose. In this research, we study the composition of the flue gas from the combustion of fuel slurries and dry composite fuels based on industrial and agricultural waste. It has been established that the use of slurry fuels makes the anthropogenic emissions 2–4 times lower than from the combustion of coal slime. For example, the CO2 emissions from the combustion of dry coal slime were 2.5–3.7 times higher than from the combustion of slurry fuels. In addition, the combustion of slurry fuels made it possible to cut down the nitrogen oxide emissions by 1.3–1.5 times and sulfur oxide emissions by 1.3–2.7 times. A comparison of the results obtained using different measurement techniques has shown that differences between the CO and CO2 content in the combustion products measured by a gas analyzer and an FTIR spectrometer did not exceed 20%. The use of FTIR spectroscopy provided new knowledge on the concentrations of hydrocarbons from the combustion of fuels based on promising industrial wastes.

Development of Thin-film Sensors for In-process Measurement during Injection Molding

Resource and energy efficiency in manufacturing is of great significance for future developments. Digitization is becoming an important strategy for meeting these challenges and opening up different paths to sustainability. Injection molding as a high-volume process technology offers great opportunities for this approach due to its wide range of applications, producing polymer parts for use in industrial, automotive and consumer use. Due to process variation and individualizations, manufacturing ramp-ups currently produce significant volumes of scrap due to process variations. For improved process parameter setting and validation of simulation models in-process measurement data is mandatory and expected to be a key enabler for automated real-time quality monitoring in future production. One way to measure temperature and melt flow directly in the cavity with contact to the melt is to use thin-film sensors. They are applied to the surface of the tool with high hardness, high wear resistance, low coefficient of friction and high load capacity, are very small and only a few micrometers thick. This research describes the development of thin-film sensors, starting with the tool concept to integrate a sensor insert, followed by the physical operating principle. The developed thin-film layer system and its fabrication process using vacuum-based deposition techniques such as physical vapor deposition and chemical vapor deposition are explained. Combined with microstructuring techniques such as photolithography, the thin-film sensor structures were fabricated and their thermoresistive behavior is characterized. The applied sensor design with a high spatial resolution to detect both temperature and flow front movement is shown. Finally, the developed sensors were experimentally tested in the laboratory. Results of temperature measurements, sensor performance and flow front movement are presented and future potential for applications are discussed.

Smart production system for the process-reliable assembly of hydrogen tube fittings

Large electrolyzer plants are needed to meet the world's demand for hydrogen. Most of the installation costs for an electrolyzer plant are incurred during production. Therefore, this article aims to illustrate a reference process for automation by assembling hydrogen tube fittings. The assembly process has not been automated yet; Thus, the physical operating principle is elaborated and implemented in a demonstrator. The process is examined simulatively and transferred in a robot cell to determine the required functionality. It is mapped entirely and optimized in the simulation, while the real demonstration shows a successful functional test of the physical operating principle.

Thick-walled coating in Gunn diode for measuring of electromagnetic radiation power in microwave range

In the introduction, the analysis of the physical basis for the operation of the semiconductor Gunn diode is carried out and the issues that should be resolved in substantiation of the basic physical principles of this diode operation are stated. At applied voltages of up to 0.6 V to a gallium arsenide or indium phosphide Gunn diode, free electrons appear in the conduction band of aluminum as a result of ionization of negative ions of gallium or indium atoms. At voltages from 0.6 to 2.0 V, free electrons appear in the aluminum conduction band as a result of ionization of negative ions of arsenic atoms, and at voltages from 0.6 to 3.0 V — phosphorus. The formation of negative gallium or indium ions is caused by electron capture directly from the aluminum base, while the formation of negative arsenic or phosphorus ions is mainly due to spontaneous electron transfer from the aluminum conduction band and from the negative gallium or indium ions. Electric current flows only over the surface of a gallium arsenide or indium phosphide crystal. The frequency of electric current oscillation is defined by the voltage applied to the Gunn diode and the thickness of the gallium arsenide or indium phosphide crystal. Determination of the power of microwave signals by the Gunn diode is carried out by applying a constant voltage between the cathode and the anode, which provides the frequency of current oscillation equal to the frequency of the measured microwave signal. The maximum radiation power in microwave wavelengths measured by the Gunn diode is determined by the equality of the electromagnetic wave perturbation energy and the electron affinity energy of gallium or indium atoms in the vicinity of the aluminum conduction band.

Development and research of layered composite materials based on Cu2ZnSnS(Se)4 for solar cells

This paper discusses the development of manufacturing technology with low costs for the production of solar cells based on Cu2ZnSnS(Se)4 crystals, elucidation of the physical principles of operation and the search for solutions to improve the efficiency of converting solar energy into electrical energy. The morphology of grown ingots and some electrophysical properties of Cu2ZnSnS(Se)4 crystals were studied.

АВТОМАТИЗОВАНА СИСТЕМА З АВТОНОМНОЮ СТАБІЛІЗАЦІЄЮ НА БАЗІ МОБІЛЬНОЇ ПЛАТФОРМИ ДЛЯ ВИМІРЮВАННЯ ТЕПЛОВИХ ПОКАЗНИКІВ ОБ’ЄКТІВ

Mobile robotic platforms are autonomous devices consisting of mechanical, electrical and electronic components that allow them to move on land, water or in the air. These platforms can be used in a variety of industries, including medicine, industry, research and intelligence, and military applications. The article deals with a new automated system with autonomous stabilization based on a mobile platform for measuring the thermal indicators of objects. The developed 3D model of a mobile robotic platform for measuring the thermal performance of objects with an autonomous stabilization system is presented. Attention is focused on the choice of optical devices for measuring the thermal performance of objects, namely, a night vision camera and a thermal imaging camera. A description of the day-night camera operation is given, and its application areas are analyzed. The physical principle of operation of thermal imaging cameras and their applications are described. It is established that the image quality varies depending on whether the thermal imager is active or passive. The TELEDYNE FLIR TAU 2 thermal imaging camera was chosen for the new mobile platform, which uses infrared imaging technology to detect the thermal signatures of objects. Possible errors of optical devices were analyzed: calibration error, reading error, video image delay error, other instrumental errors (from the influence of temperature, lighting, orientation in space, noise, etc.). Experimental studies of the developed mobile robotic platform for measuring the thermal performance of objects with an autonomous stabilization system were carried out, having previously calibrated it, and their results are presented. It is determined to measure the surface temperature of an object using a thermal imaging camera; it is necessary to know its emission, which is determined by the properties of the material from which the object is made. This can be done using a calibrated infrared source, making it possible to measure the temperature of objects in the image accurately.

Sorghum as a substitute for corn in poultry feed

The article substantiates the expediency of using sorghum grain (seeds) as a substitute for corn in feed for poultry. The aim of the study was to develop a recipe and technology for the preparation of compound feed of increased nutritional value for birds using sorghum grain subjected to IR - processing. Examples of its impact on grain quality and its biological value are considered. The physical principles of operation of this technology and the properties of the applied method are analyzed. It was found that protein digestibility and attack by its enzymes increased from 82.3 to 89.8%. The results of a comparative zootechnical assessment of the quality of feed without sorghum and with the replacement of 47.0% of corn with this raw material are presented. The economic efficiency from the use of the proposed composition of feed for chickens and the profitability of its production have been established.

Methods for downhole soil water sensor calibration—Complications of bulk density and water content variations

AbstractDownhole soil volumetric water content (VWC) sensors are used in access tubes to assess the soil water content at multiple depths. If sensor readings are spaced closely enough vertically and are accurate enough, then accurate soil profile water content storage and change in storage can be determined over the depth range of readings, leading to accurate estimates of evapotranspiration (ET) if readings extend to well below the root zone. Even if sensing only covers the active root zone, soil water depletion may be determined well enough to inform irrigation scheduling. While sensor accuracy is dependent on many factors, including the sensor's physical principle of operation, soil‐specific calibration is typically required for good accuracy. In soils with multiple horizons (layers) of different texture, bulk density (BD), or chemical composition, horizon‐specific calibrations may be necessary. We describe methods and equipment used for downhole sensor calibration to typical accuracy of <0.01 m3 m−3 with specific reference to calibration of 10 neutron scattering meters in a soil that required three different horizon‐specific calibrations. Our results contrast with the factory calibration, which would result in a 38‐mm error in water stored in a 1.5‐m deep profile of our soil. We describe variability of measured VWC and BD with depth, distance, and water content and the errors that result from using BD to convert mass basis (g g−1) water content data to VWC data, which can be as much as 35 mm (7.26% underestimation) for soil water storage in a 1.5‐m deep profile of our soil.

Calculation of Step Discontinuities in Electric Circuits: A Time-Domain Analysis

Contribution: Two general rules for calculating, in the time domain, step discontinuities of voltages and currents in electric circuits, combining physical principles and basic mathematical treatment. The two general rules, resulting from a formal method of analysis, provide a straightforward way to update the states of a circuit, immediately after the occurrence of switching or impulsive excitation. Among its advantages, they can be used to simplify the numerical simulation of elaborate circuit topologies by avoiding approximate models of impulsive sources or switches. Background: In most engineering undergraduate textbooks, the effects of switching and impulsive sources on higher order electric circuits are usually studied for the particular case of linear time-invariant (LTI) circuits in the Laplace transform domain. This approach, however, can be time consuming and demands little reasoning on the physical principles of circuit operation. Moreover, it is not adequate for linear time-variant or nonlinear circuits. Intended Outcomes: Step discontinuities in electric circuits, caused by switching or impulsive sources, are identified and calculated through the method, allowing complete responses to be obtained afterward. Not only can the method be extended to linear time-variant and nonlinear circuits but it also has interesting consequences in numerical simulation of circuits. Application Design: An application exercise and a set of conceptual questions on the subject were proposed to electrical engineering students. Findings: The analysis of the educational experiment indicates that applying the method presented herein improves the students’ ability to obtain initial conditions of circuits, being a more straightforward and effective approach than using Laplace transform techniques.

The concept of a new two-stage fuse for high power pulse forming

This manuscript introduces the concept, physical operating principle and studies on a new and unique two stage forming fuse (TSFF) with interstage spark gap commutation and presents its application for forming high power pulses of extreme parameters. The paper classifies TSFF performance and compares it with conventional single-stage forming fuses. The conclusions are supported by analytical and experimental studies in laboratory conditions. The design of the TSFF prototype as well as the applied measurement methods and test stands are also presented. The developed technology of the TSFF enables the achievement of unprecedented parameters of high-power pulses with overvoltages reaching 800 kV and pulse power of tens of GW in a very compact design. The unique properties of the TSFF enable its efficient integration with a wide range of energy sources, even with very limited current rising steepness or limited output voltage, which has not been possible so far with conventional single-stage forming fuses. The proposed system can be easily scaled, while ensuring much greater flexibility of applications.

(Invited) Decoding the Symbiotic Relationship between Ionomer and Water in Cathode Catalyst Layers of PEM Fuel Cells

The pressing need for highly-performing and environmentally benign energy technologies continues to spur on research on polymer electrolyte fuel cells (PEFC). Among the components that are needed for a well-functioning, durable, and affordable PEFC, the cathode catalyst layer (CCL) continues to stand out. The main function to be provided by the CCL is to facilitate the oxygen reduction reaction (ORR). However, this function entails an intricate interplay of microscopic kinetics with the transport of electrons, protons, oxygen molecules, and water. A hierarchy of structural effects must be considered, as illustrated in Figure 1. Due to the complex composition and multiscale nature of the CCL, physical modeling has gained high importance in efforts to rationalize the dynamic interplay of structure, properties, and performance. The first part of the presentation will briefly review the capabilities of model-based analyses of experimental data to deconvolute and quantify voltage loss contributions,1 extract kinetic and transport parameters from fitting and discover systematic trends and correlations among these parameters,2 provide an activity map of the layer, and evaluate the overall effectiveness factor of Pt utilization.3 Macrohomogeneous modelling can propose or predict the optimal CCL thickness or macroscopic effective composition (for the target range of operating conditions).Recognizing the importance of an optimal water-distribution for a well-functioning CCL, recent efforts in CCL modeling have been focusing on the consistent treatment of aspects like pore size distributions and pore network morphologies as well as wettability properties. The ionomer inclusions in the CCL play a crucial role in this context. At the microscopic scale, the ionomer film that forms an interface with the water-covered catalyst-support surface strongly impacts the local reaction environment that determines the rate of the ORR as well as that of platinum dissolution. Moreover, the structure and distribution of ionomer inclusions determine the wetting behaviour of pores and thus the water sorption properties of the porous composite CCL, which in turn affect the transport properties for oxygen and water. Recent forays in modelling that strive to unravel the intertwined impacts of ionomer and water will be presented. As a final consideration, a CCL cannot be understood and optimized as a stand-alone component. Overarching balances at the PEFC level in terms of reactant, charge, water, and heat fluxes must be considered. Comprehensive modeling approaches must account for the coupling of the corresponding local equilibria and transport phenomena across the whole cell, including polymer electrolyte membrane, diffusion media and flow fields. Efforts focusing on the coupled water fluxes across the cell are underway with promising results to look out for. References. 1 M. Baghalha, J. Stumper and M. Eikerling, ECS Transactions 28, 159–167 (2010). 2 T. Muzaffar, T. Kadyk and M. Eikerling, Sustainable Energy & Fuels 2, 1189–1196 (2018). 3 M. Eikerling and A.A. Kulikovsky, Polymer Electrolyte Fuel Cells – Physical Principles of Materials and Operation, CRC Press Taylor & Francis Group, 2014. Figure 1