Operation Principle Research Articles

Обзор исследований высокоэнтропийных сплавов, их свойств, методов создания и применения

Introduction. The paper discusses the prospects for studying high-entropy alloys (HEA), metal materials with unique properties. The study of high-entropy alloys is an urgent area of research in connection with its properties, environmental sustainability, economic benefits and technological potential. HEA are of interest to researchers due to its stability, strength, corrosion resistance and other characteristics, which makes it promising for use in the aerospace industry, automotive, medicine and microelectronics. Thus, HEA research contributes to the development of new materials and technological progress, providing opportunities for creating innovative products and improving existing solutions. To effectively use the potential of high-entropy alloys, research is required in a number of areas. First, it is necessary to improve the production technology of such alloys and develop new methods for obtaining HEA with improved characteristics and reduced cost. Secondly, it is necessary to establish the basic principles of operation of high-entropy alloys and to study the mechanisms influencing its properties. It is also necessary to develop new alloys with specified properties and conduct experiments and computer simulations to optimize the characteristics of the alloys and determine the best compositions. The purpose of the work is to study developments in the field of high-entropy alloys and conduct a comparative analysis of published studies on improving the properties of high-entropy alloys. The research method is a review and analysis based on developments mainly for 2020-2024, which were carried out by domestic and foreign scientists. The paper discusses the prospects for the study of high-entropy alloys, materials with a wide range of applications in various industries. The paper presents the results of research, mainly for 2020-2024. The main properties of high-entropy alloys are described, such as high strength, corrosion resistance, fatigue properties, plasticity and deformability, thermal stability, electrical conductivity and magnetic properties, as well as the possibility of creating alloys with specified characteristics. The most common methods of changing the properties of alloys have been identified. The directions of further development of research in this area are considered. Results and discussion: a literature review shows that developments and research are carried out on all possible properties of HEA, but most of it is devoted to corrosion-resisting properties and thermal stability. Of the methods used in high-entropy alloys, the most common and universal can be considered the alloying of high-entropy alloys with other metals. Studies also confirm that alloying metals are selected depending on its characteristic properties. The number of scientific works also confirms the relevance of this topic and the need for its study. The authors noted that future studies on the fatigue properties of high-entropy alloys, as well as the properties of alloys under the influence of magnetic and electric fields are the most interesting.

High Step‐Up Isolated Multi‐Input Converter Based on Three‐Winding Coupled Inductor and Quasi‐Z‐Source for Excellent Voltage Gain With Independent Control and Expandability

ABSTRACTThis article introduces a high step‐up isolated multi‐input converter (HSIMIC), which utilizes a three‐winding coupled inductor and a quasi‐Z‐source to obtain an extra‐high voltage gain and to feature galvanic isolation. The HSIMIC only requires a minimum count of active switches. In HSIMIC, diodes have zero current switching (ZCS) features at turn‐off, and leakage energy can be recycled. Based on the configuration of HSIMIC, the input sources can be processed simultaneously or individually. Even if either of the input sources is interrupted, the converter can still function and maintain the high step‐up characteristic. In addition, the input port number can be easily extended to deal with more clean energy sources. The converter operation principle, theoretical analysis, essential parameter design, and simulations are carried out. A 400‐W prototype is built and then tested to verify the theoretical analysis and validate the proposed HSIMIC.

Investigating Multidimensional Degenerate Hybrid Special Polynomials and Their Connection to Appell Sequences: Properties and Applications

This paper explores the operational principles and monomiality principles that significantly shape the development of various special polynomial families. We argue that applying the monomiality principle yields novel results while remaining consistent with established findings. The primary focus of this study is the introduction of degenerate multidimensional Hermite-based Appell polynomials (DMHAP), denoted as An[r]H(l1,l2,l3,…,lr;ϑ). These DMHAP forms essential families of orthogonal polynomials, demonstrating strong connections with classical Hermite and Appell polynomials. Additionally, we derive symmetric identities and examine the fundamental properties of these polynomials. Finally, we establish an operational framework to investigate and develop these polynomials further.

Application of rare earth elements in dual-modality molecular probes.

The unique 4f subshell electronic structure of rare earth elements endows them with exceptional properties in electrical, magnetic, and optical domains. These properties include prolonged fluorescence lifetimes, large Stokes shifts, distinctive spectral bands, and strong resistance to photobleaching, making them ideal for the synthesis of molecular probes. Each imaging technique possesses unique advantages and specific applicabilities but also inherent limitations due to its operational principles. Dual-modality molecular probes effectively address these limitations, particularly in applications involving high-resolution Magnetic Resonance Imaging (MRI) such as MRI/OI, MRI/PET, MRI/CT, and MRI/US. This review summarizes the applications, advantages, challenges, and current research status of rare earth elements in these four dual imaging modalities, providing a theoretical basis for the future development and application of rare earth elements in the field of dual-modality molecular probes.

Customizable Microfluidic Devices: Progress, Constraints, and Future Advances.

The field of microfluidics encompasses the study of fluid behavior within micro-channels and the development of miniature systems featuring internal compartments or passageways tailored for fluid control and manipulation. Microfluidic devices capitalize on the unique chemical and physical properties exhibited by fluids at the microscopic scale. In contrast to their larger counterparts, microfluidic systems offer a multitude of advantages. Their implementation facilitates the investigation and utilization of reduced sample, solvent, and reagent volumes, thus yielding decreased operational expenses. Owing to their compact dimensions, these devices allow for the concurrent execution of multiple procedures, leading to expedited experimental timelines. Over the past two decades, microfluidics has undergone remarkable advancements, evolving into a multifaceted discipline. Subfields such as organ-on-a-chip and paper-based microfluidics have matured into distinct fields of study. Nonetheless, while scientific progress within the microfluidics realm has been notable, its translation into autonomous end-user applications remains a frontier to be fully explored. This paper sets forth the central objective of scrutinizing the present research paradigm, prevailing limitations, and potential prospects of customizable microfluidic devices. Our inquiry revolves around the latest strides achieved, prevailing constraints, and conceivable trajectories for adaptable microfluidic technologies. We meticulously delineate existing iterations of microfluidic systems, elucidate their operational principles, deliberate upon encountered limitations, and provide a visionary outlook toward the future trajectory of microfluidic advancements. In summation, this work endeavors to shed light on the current state of microfluidic systems, underscore their operative intricacies, address incumbent challenges, and unveil promising pathways that chart the course toward the next frontier of microfluidic innovation.

Evaluating a novel bidirectional soft-switching DC-DC converter for electric vehicles

This research aims to build unique zero voltage transition (ZVT) non-isolated bidirectional DC-DC converters for hybrid electric vehicle battery storage. First, a high-voltage gain bidirectional converter (BDC) is examined. This converter can soft-switch insulated gate bipolar transistors (IGBTs). The primary insulated-gate bipolar transistors (IGBTs) are operated under zero-current conditions throughout the turn-on to turn-off commutation phase to reduce switching losses and increase efficiency. A soft-switched cell with a resonant inductor, capacitor, and additional IGBTs achieves zero-current turn-off. A new converter uses insulated-gate bipolar transistors with zero-voltage transition operation. Soft-switched cells improve the hard-switched bridgeless DC-DC converter (BDC). Resonant inductors, capacitors, and auxiliary switching devices make up the soft-switched cell. Soft-switched cells enable zero voltage turn-on of primary insulated-gate bipolar transistors. This converter charges the battery in buck mode and boosts it to provide the necessary output voltage. This study examined a 70 V/300 V power system's high-gain bidirectional converter (BDC) design simulation. The converter was tested at 50 kHz with 800 W output power. The high-gain soft-switched BDC has 96.5% boost and 97% buck efficiency. Operating principles, design analysis, and simulation assessments are included in this study.

Mission of the continuous training center for “Teleradio-Moldova” employees. P principles of organization and operation

Periodic transformations taking place in society project new approaches in the value field of an entity or organization, which aims to effectively strengthen human resources in relation to the workspace, in line with the requirements of the times and daily realities. Thus, the evolution on the axis of training and development acquires quantitative and qualitative variables, aimed at increasing the functioning process of an organization or institution. The scientific approach comes to analyze and explain the role and importance of the concept of continuous training for employees in the media industry. The perception of how employees interact with each other, how the team is conceptualized, how functions are distributed within departments/sections/editorial offices, etc., is also highlighted, from the perspective of managing the responsibilities and tasks that form the institutional status of the media entity. The article also includes a case study that reveals the mission of the Continuous Training Center (CIC) within the “Teleradio-Moldova” (TRM) Company in the context of the professional development of journalists. In this context, the importance of continuous training in the media field is highlighted, determined by the rapid changes in the industry and the need to adapt to the new demands of the audience.

A Comprehensive Strategy for Implementing Adaptive Data Rate (ADR) in LoRaWAN Technology: Optimizing IoT Networks

The Internet of Things (IoT) is increasingly essential for creating smart environments by establishing long range connectivity among devices. LoRaWAN is a prominent technology choice for these applications due to its energy efficiency and extensive coverage. Central to LoRaWAN’s functionality is the Adaptive Data Rate (ADR) mechanism, which optimizes network performance by adjusting each device’s data rate and transmission power dynamically. This study delves into ADR’s operational principles, benefits, and implementation challenges in LoRaWAN networks. The proposed simulation model, featuring configurable parameters like the spreading distribution factor (SF), the adjustable number of devices, and the SNR threshold, denotes enhanced network performance after implementing the ADR algorithm. With an SNR threshold of 15 dB, ADR reduced the average transmission power of 200 devices from 7 dBm to 3 dBm after twenty iterations, underscoring ADR’s role in minimizing energy consumption while improving network efficiency.

A Review on The Nitrogen Laser

Abstract: A nitrogen laser is a type of gas laser that uses molecular nitrogen as its gain medium to operate in the ultraviolet (UV) spectrum. First created in 1963, nitrogen lasers were first put to use in commerce in 1972. A nitrogen laser is a type of gas laser that uses molecular nitrogen as its gain medium to operate in the ultraviolet (UV) spectrum. First created in 1963, nitrogen lasers were first put to use in commerce in 1972.Applications for nitrogen lasers can be found in physics, chemistry, and medical research. The principle of operation for nitrogen lasers is a quick electrical discharge through nitrogen gas. Liquid nitrogen or a gas cylinder might be used to supply the nitrogen gas. The UV-wavelength laser light has a short pulse width and a high intensity. The principle of operation for nitrogen lasers is a rapid electrical discharge via nitrogen gas. Liquid nitrogen or a gas cylinder might be used to supply the nitrogen gas. The laser light has a short pulse width, high intensity, and is released into the ultraviolet spectrum. Electricity is used by the nitrogen laser to excite the nitrogen. The electrons in the laser strike the nitrogen atoms in the air when an electric spark passes through a spark gap, stimulating them into a metastable condition. A photon with a wavelength of 337 nm causes stimulated emission and the creation of a laser state in the excited nitrogen atoms. Electricity is used by the nitrogen laser to excite the nitrogen. The nitrogen atoms in the air are excited into a metastable condition when an electric spark passes through a spark gap in the laser. A photon with a wavelength of 337 nm causes stimulated emission and the creation of a laser state in the excited nitrogen atoms. [22]

Reducing the amount of computations at the second stage of an ensemble classifier with stacking on mine-detection drones

Using drones to search for mines is a promising area that allows accelerating the process of demining an area and reducing the danger to people. To increase the probability of detecting mines, drones use sensors with different operating principles. Each type of sensor requires specialized processing, which is carried out at the first stage of the ensemble classifier with stacking. The sensor signals are combined at the second stage of the ensemble classifier, where a multilayer perceptron is usually used as a neural network. Acceleration of terrain survey requires that processing be carried out in real time on the computing equipment of the drone itself. This, in turn, requires a reduction in the amount of computation for all algorithms used on the drone. The article is devoted to reducing the amount of computation when implementing a multilayer perceptron. The original homogeneous structure of the perceptron, when each of the neurons of the previous layer has connections with all neurons of the next layer, is redundant, since it does not take into account the features of the processed data set. The article proposes a method for finding a balance between the dimensionality and number of layers of the perceptron, the time interval between the procedures of thinning connections, the training step and the number of connections removed at a time. Using thinning connections taking into account other parameters allows you to reduce the amount of calculations by 80% or more, while saving and even increasing the quality of classification. There are removed connections that do not make a noticeable contribution to the quality of classification, but introduce additional noise into the perceptron training process and the formation of the output result.

Revenue distribution in streaming

The streaming industry has experienced exponential growth over the past decade. Streaming platforms provide subscribers with unlimited access to a diverse range of services, including movies, TV shows, and music, in exchange for a subscription fee. We take an axiomatic approach to the problem of how to share the overall revenue obtained from subscription sales among services or content producers. In doing so, we provide normative justifications for several distribution rules. We formulate several axioms that convey ethical and operational principles. In the first group, we consider properties that guarantee equal and impartial treatment of services and subscribers. In the second group, we introduce requirements designed to safeguard allocation schemes from inconvenient alterations, namely, changes in the units of measurement of inputs, subscription sharing, or group decomposition. Our analysis reveals that different combinations of these axioms define two classes of rules that strike a balance between three focal schemes, each representing distinct perspectives on the egalitarian and proportional principles. To illustrate the practical implications of our theoretical model, we explore its potential application by assessing how various types of content impact the revenues of some of the most well-known Twitch streamers.

Algorithmic Efficiency in Convex Hull Computation: Insights from 2D and 3D Implementations

This study examines various algorithms for computing the convex hull of a set of n points in a d-dimensional space. Convex hulls are fundamental in computational geometry and are applied in computer graphics, pattern recognition, and computational biology. Such convex hulls can also be useful in symmetry problems. For instance, when points are arranged symmetrically, the convex hull is also likely to be symmetrically shaped, which can be useful for object recognition in computer vision or pattern recognition. The focus is primarily on two-dimensional algorithms, including well-known methods like Gift Wrapping, Graham Scan, Divide and Conquer, QuickHull, TORCH, Kirkpatrick–Sediel, and Chan’s algorithms. These algorithms vary in terms of time complexity and scalability to higher dimensions. This study is extended to three-dimensional convex hull algorithms, such as NAW, randomized insertion, and parallelized versions, such as CudaHull and CudaChain. This study aimed to elucidate the operational principles, step-by-step procedures, and comparative time complexities of each algorithm. The implementation in Python facilitates a detailed comparison of the algorithmic performance through stepwise analysis and graphical outputs. The ultimate goal is to provide insights into the strengths and weaknesses of each algorithm under various scenarios, thereby offering a comprehensive guide for practical implementation.

A Cylindrical Lens Spectrometer with Parallel Detection for Reflection Electron Energy Loss Spectroscopy.

Reflection electron energy loss spectroscopy (REELS) has played a pivotal role in allowing researchers to explore the characteristics of various bulk materials. This study presents results for the low-loss region of REELS with a new cylindrical lens spectrometer integrated into a low-voltage scanning electron microscope. The operational principles and implementation of the spectrometer are explained through comparisons between electron optical simulations and experimental results. Notably, the analysis shows the ability to distinguish samples in film and bulk forms. Graphene and graphite, despite their identical elemental composition and crystalline structure, are found to have distinct energy spectra as indicated by plasmon peaks. Furthermore, the study explores the bandgap measurement of SiO2 at low-energy conditions of 2.5 keV, highlighting the proposed instrument's advantages in the measurement without the harmful effect of Cherenkov loss. Additionally, this method reaffirms the capability to measure multiple plasmon peaks from the energy spectra of bulk gold samples, thus introducing a pioneering avenue in energy spectrum measurement. Leveraging the compact size and simple experimental setup of the spectrometer for REELS, the method enables the measurement of energy spectra of both bulk- and film-formed samples under low electron energy conditions, marking a significant advancement in the field.

Different Techniques of Steganography in Images

Abstract—Steganography is a vital technique in information security that conceals data within other non-secret data, primarily images. This paper explores four prominent image steganography techniques: Least Significant Bit (LSB), Pixel Value Differencing (PVD), Discrete Cosine Transform (DCT), and Masking & Filtering. Each method is examined in terms of its operational principles, advantages, and limitations. LSB is straightforward but vulnerable, while PVD offers higher capacity and robustness. DCT enhances resistance against compression, and Masking & Filtering maintains high image quality. A comparative analysis illustrates the effectiveness of these techniques regarding capacity, complexity, and robustness, providing insights for researchers and practitioners in selecting appropriate steganography methods for secure communication. Keywords: Steganography, LSB, PVD, DCT, Masking & Filtering, Image Processing

Flexible bioelectronic systems with large-scale temperature sensor arrays for monitoring and treatments of localized wound inflammation

Continuous monitoring and closed-loop therapy of soft wound tissues is of particular interest in biomedical research and clinical practices. An important focus is on the development of implantable bioelectronics that can measure time-dependent temperature distribution related to localized inflammation over large areas of wound and offer in situ treatment. Existing approaches such as thermometers/thermocouples provide limited spatial resolution, inapplicable to a wearable/implantable format. Here, we report a conformal, scalable device package that integrates a flexible amorphous silicon-based temperature sensor array and drug-loaded hydrogel for the healing process. This system can enable the spatial temperature mapping at submillimeter resolution and high sensitivity of 0.1 °C, for dynamically localizing the inflammation regions associated with temperature change, automatically followed with heat-triggered drug delivery from hydrogel triggered by wearable infrared light-emitting-diodes. We establish the operational principles experimentally and computationally and evaluate system functionalities with a wide range of targets including live animal models and human subjects. As an example of medical utility, this system can yield closed-loop monitoring/treatments by tracking of temperature distribution over wound areas of live rats, in designs that can be integrated with automated wireless control. These findings create broad utilities of these platforms for clinical diagnosis and advanced therapy for wound healthcare.

A 3D printed microfluidic device for centrifugal droplet generation

PurposeThis study aims to use an additive process for the first time to develop a microfluidic device that uses centrifugal technique for precise and repeatable generation of microdroplets. Droplets have versatile applications in life sciences, but so far centrifugal devices for their production have been made mainly using standard subtractive techniques. This study focused on evaluating the applicability of 3D printing technology in the development of centrifugal microfluidic devices and investigating their properties and future applications.Design/methodology/approachFirst, the background of this interdisciplinary research, including the principle of droplet microfluidics and the centrifugal technique, is explained. The developed device has the form of a disc (similar to an audio CD), containing an integrated microfluidic system for droplet generation. The disc is rotated at a specific spin profile to induce controlled liquid flow and accurate production of oil-in-water microdroplets. The device was fabricated using material jetting technology. The design, operation principles, printing process parameters and post-processing steps are explained in detail.FindingsThe device was thoroughly characterised, including its mechanical properties, the impact of chemical treatment and the flow measurement of the liquids. The study confirms that the disc can be applied to produce various emulsions using centrifugal force alone. 3D printing technology enables potential mass production and other applications of the device.Originality/valueThe 3D printing process allowed for easy design, fabrication and duplication of the device. Compared to standard PMMA discs, a simpler fabrication protocol and a more flexible and monolithic structure were obtained. The device can be adapted to other microfluidic processes in a lab with high potential for point-of-care applications.

Miniaturized, portable gustation interfaces for VR/AR/MR

Gustation is one of the five innate sensations for humans, distinguishing from vision, auditory, tactile, and olfaction, as which is a close and chemically induced sense. Despite the fact that a handful of gustation display technologies have been developed, the new technologies still pose significant challenges in miniaturization of the overall size for portability, enriching taste options within a limited working area, supporting natural human-device interaction, and achieving precisely controlled taste feedback. To address these issues, here, we report a set of intelligent and portable lollipop-shaped taste interfacing systems covering from 2 to 9 different taste options for establishing an adjustable taste platform in virtual reality (VR), augmented reality (AR), and mixed reality (MR) environments. Tasteful and food-grade chemicals embedded agarose hydrogels serve as taste sources based on iontophoresis operation principle, with an adjustable feedback intensity and independent operation time by tuning the voltage input. To achieve portability and user-friendly operation, the devices are miniaturized into a gustation interface with 9-channel taste generators in the dimension of 8 cm × 3 cm × 1 cm. To realize both gustation and olfaction feedbacks in Metaverse, an olfaction interface based on 7-channel odor generators is also introduced into the gustation interface system. As a result, the demonstrations of our gustation interface systems in intelligent medical gustation assessment, remote shopping, and mixed reality have proven their advances and great progress in various potential application areas, ranging from human-machine interfaces, to biomedical science, and to entertainment.

Energy-efficient power summator of hydrogen fuel cell

The most important task after the end of the COVID-18 pandemic is to solve the problem of preserving the planet's climate and improving the environment in populated areas (metropolises, cities, towns). The most important principles contributing to the solution of this problem were set out in the Centenary Memorandum (A.L. Gusev, T.N. Veziroglu, J. Sheffield and other scientists, 2006). The most important element of hydrogen energy is the fuel cell. Fuel cells are produced in different modifications, they can be different in principle of operation, and different in size and DC generation power. Large consumers, both stationary and autonomous, at different times consume different amounts of power from the minimum value to the average and maximum. Obviously, if an object consumes minimal power over a given period of time, then there is no point in generating maximum power. Typically, fuel cells are designed for a specific power range. In connection with the above, in practice situations arise when it is necessary, depending on energy consumption, to connect hydrogen fuel cells of various powers.A new principle for constructing energy-efficient and small-sized summing step-up capacitor DC-DC converters (SSCC) capable of not only converting the level of output voltages, but also summing the powers of several sources in a common load is proposed. The sources are hydrogen fuel cells converted into constant voltage sources, different in output parameters and having a common grounded bus. The principle of multi-cycle construction of SSСС is proposed, which provides additional improvement of their weight and size characteristics under conditions of increased source power. It is shown that the effect is achieved by a multiple increase in the conversion frequency of individual SSСС modules and the practical elimination of a bulky output capacitor due to a sharp decrease and multiple increase in the frequency of the first harmonic of the total output current. Analytical expressions have been obtained that make it possible to calculate the parameters of the reactive elements of the SSСС, to analyze and quantify their efficiency.

Finite element analysis and experimental verifications of low-speed rotor torque of magnetic-geared motor with permanent magnets only in stator

We propose a magnetic-geared motor with controllable step-out torque. The operational principle which controls the step-out torque using DC currents is described. The controllable step-out torque characteristics are computed using finite element method. In addition, the load characteristics under vector control are also computed using finite element method. Two inherent characteristics are observed in this analysis result. One is that this magnetic-geared motor can generate the torque more than the step-out torque. The other is that the phase angle difference between the rotors when both rotors step out is around 30 deg. In this paper, the mechanism of these inherent characteristics is investigated by finite element method, and these inherent characteristics are verified by carrying out measurements on a prototype.

Novel Multipoint-drive Rotary Actuator for Extraterrestrial Celestial Ultrasonic Driller

Ultrasonic drilling has emerged as a prominent technique in extraterrestrial environments due to its advantageous features. However, its application in extraterrestrial sampling missions is constrained by challenges such as drilling, chip removal efficiency, and high and low temperature adaptability. Addressing these limitations, this study introduces a novel multi-point driven rotary helical longitudinal torsion horn. The initial phase involved a detailed analysis of the actuator’s structure and operational principle. Subsequently, the actuator’s vibration mode and elliptical motion trajectory were validated through finite element simulation. The study further explores a methodology for adjusting the parameters of the helical groove and the displacement amplitude of the impact head. Following the theoretical analysis, prototypes of the actuator and drill were fabricated. Their adaptability to high and low temperatures, as well as their output characteristics, were rigorously tested. Experimental results demonstrate that with an increase in temperature, the dynamic impedance of the actuator initially rises before decreasing, while the mechanical quality factor exhibits the opposite trend. Notably, the concurrent activation of points P1 and P2 significantly enhances the no-load speed, achieving a maximum of 506 revolutions per minute (r/min). Under conditions of power below 35 W and a drilling pressure of 10 N, the drilling speed achieved in basalt is 6.2 millimeters per minute (mm/min). The proposed multipoint-driven actuator can effectively improve the drilling and chip removal efficiency of the driller, which is an important application prospect in future extraterrestrial drilling missions.