Selection Of Components Research Articles

The impacts of phase noise on a long-baseline cross-eye jammer

Cross-eye jamming is a technique used for deceiving the angle measurement of monopulse radars. Long baseline (i.e., long spacing of jammer antennas) is an attractive option for cross-eye jammers, which can increase the angular error for monopulse radars. Phase error is a key factor restricting the performance of cross-eye jammers. In this paper, one of the sources of the phase error, i.e., local oscillator (LO) phase noise, is analyzed for a long-baseline cross-eye jammer. The effect of LO phase noise on the jamming performance is revealed for the first time. Additionally, the tolerance requirements for the LO phase noise of long-baseline cross-eye jammers are determined through theoretical analyses. Finally, the theoretical analyses are verified by Monte Carlo simulations. The research results can provide theoretical insights for system design and component selection for cross-eye jammers.

SPECIFICS OF DESIGNING AN INFRARED PYROMETER-REFLECTOMETER FOR SEMICONDUCTOR HETEROSTRUCTURE FABRICATION

There are general technical requirements for all types of reactors for chemical vapour deposition technology using AIII- BV metalorganic compounds. Among them, it is worth highlighting the large temperature gradients that cause the origin of convection loops, which in turn, taking into account the high speed of the gas flow, lead to turbulence in the reactor instead of the expected laminar flow. It is also important to take into account the change in parameters of the wafer surface during the growth process and the need for signal separation between the useful signal from the wafer surface and the background signal from the wafer carrier, which rotates at fixed speed for uniform deposition of compounds. To obtain high-quality heterostructures with reproducible parameters, it is important to have a system of precise temperature control on the wafer surface directly in the deposition area, since the deposition process for many complex semiconductor devices (for example, laser diodes, LEDs, photodiodes, transistors on heterojunctions) is very sensitive to temperature changes. The method of optical pyrometry is a non-contact method that allows to precisely determine the temperature of the wafer surface and meets the technical requirements of CVD epitaxy growth reactors. This article is devoted to the analysis of the features of the development of optoelectronic systems for precise temperature measurement during epitaxial growth in order to determine the criteria for the selection or development of components of the optoelectronic system of the pyrometer-reflectometer. The main physical processes, electro-optical characteristics of Si photodiode, AlGaAs/GaAs LED and parameters of bandpass interference filters were investigated. Based on the analysis of the obtained research and measurement results, scientific recommendations have been developed. The recommendations aimed at the selection and optimization of the parameters of the components of the pyrometer-reflectometer (photodetectors, light emitting diodes, optical filters) in order to improve the accuracy and temperature stability of measurements in the pyrometer’s operation conditions, which take into account the compensation of emissivity change from the surface of the wafer.

Research and application of continuous and precise nitrogen injection fire extinguishing technology in coal mines

To overcome shortcomings in traditional nitrogen injection fire prevention techniques, such as discontinuous nitrogen distribution, poor inerting effects, and severe waste of pipeline resources, a method for continuous and precise nitrogen injection fire extinguishing was proposed. To implement this method, this study utilizes FLUENT, FLAC 3D simulations, and principles of elasticity to determine the process and dynamic parameters of nitrogen injection. This information guides the selection, design, and manufacturing of equipment components, leading to the development of a novel “rotating towing type” continuous and precise nitrogen injection fire extinguishing equipment. Taking Wenzhuang 15,102 working face as an example, the inerting effect was compared and analyzed by using CO, Graham coefficient R2 (ΔCO/ΔO2), R3 (ΔCO/ΔCO2) and other quantitative indicators. The findings revealed following results: after deploying this equipment, there was an approximate 70 % reduction in CO concentration. Comparatively, R2 in the extraction area decreased by 45 % compared to the 0.38 % observed in the buried pipe nitrogen injection process. Similarly, the R3 values for the gob and upper corner were reduced by about 56 % and 60 %, respectively. These substantial improvements highlight the superior efficacy of the continuous and precise nitrogen injection fire extinguishing method for nitrogen injection and fire suppression in gobs.

Design and Research of Intelligent Fixture for Drawing Machine

Tensile machine is a very sophisticated test equipment, which can test the mechanical properties of some materials. In the drawing machine, the clamping device is to prevent the relative displacement and vibration phenomenon in the process of tensile test. The clamping device is the most important part of the structure of the test machine, and the main task of the clamping device is to control the degree of freedom of the specimen needs to be clamped, so as to further add loads to the various specimens to be held, and finally complete the mechanical property test of the material. But at present, the existing fixture mechanism is mainly hydraulic, pneumatic, mechanical fixture. At present, the existing mechanical fixture still has bending stress during the clamping process, which will affect the accuracy of the experiment. Therefore, a clamping mechanism with adjustable clamping force and flat pushing is designed. An electric control type fixture mechanism is very rare, so in this paper, an electrically controlled fixture is designed on this basis. The main contents are as follows: (1) On the basis of the existing fixture types, the working mode of the fixture is studied, and the working principle related to the fixture is mastered. (2) The main components of the fixture mechanism are analysed, the design scheme is determined, and the selection of the components of the drive part and the selection of the related components within the fixture mechanism is completed. ( 3) The force analysis of the main body of the fixture is carried out by using theoretical mechanics knowledge, and the relevant calculations are completed. The solid modeling of the whole mechanism is completed by using SolidWorks. The force analysis of key parts is carried out by using ANSYS software, and the correctness and safety of material selection and design are verified. The main parts of the fixture mechanism to complete the corresponding force analysis, and the theoretical calculation results are compared and verified, and finally realize the electric control of the fixture mechanism and complete the design of the fixture mechanism.

Breast cancer patient-derived organoids for the investigation of patient-specific tumour evolution

BackgroundA reliable preclinical model of patient-derived organoids (PDOs) was developed in a case study of a 69-year-old woman diagnosed with breast cancer (BC) to investigate the tumour evolution before and after neoadjuvant chemotherapy and surgery. The results were achieved due to the development of PDOs from tissues collected before (O-PRE) and after (O-POST) treatment.MethodsPDO cultures were characterized by histology, immunohistochemistry (IHC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), confocal microscopy, flow cytometry, real-time PCR, bulk RNA-seq, single-cell RNA sequencing (scRNA-seq) and drug screening.ResultsBoth PDO cultures recapitulated the histological and molecular profiles of the original tissues, and they showed typical mammary gland organization, confirming their reliability as a personalized in vitro model. Compared with O-PRE, O-POST had a greater proliferation rate with a significant increase in the Ki67 proliferation index. Moreover O-POST exhibited a more stem-like and aggressive phenotype, with increases in the CD24low/CD44low and EPCAMlow/CD49fhigh cell populations characterized by increased tumour initiation potential and multipotency and metastatic potential in invasive lobular carcinoma. Analysis of ErbB receptor expression indicated a decrease in HER-2 expression coupled with an increase in EGFR expression in O-POST. In this context, deregulation of the PI3K/Akt signalling pathway was assessed by transcriptomic analysis, confirming the altered transcriptional profile. Finally, transcriptomic single-cell analysis identified 11 cell type clusters, highlighting the selection of the luminal component and the decrease in the number of Epithelial–mesenchymal transition cell types in O-POST.ConclusionNeoadjuvant treatment contributed to the enrichment of cell populations with luminal phenotypes that were more resistant to chemotherapy in O-POST. PDOs represent an excellent 3D cell model for assessing disease evolution.

Method of pre-project selection of components for fpv uavs the quadropter type according to the set values of thrust, speed and flight time

Method of pre-project selection of components for fpv uavs the quadropter type according to the set values of thrust, speed and flight time

Thermodynamic evaluation of thermomagnetic motors with first and second order transition magnetocaloric materials

Thermomagnetic motors serve as energy harvesters by converting low-grade thermal wastes into useful mechanical power. This paper proposes a mathematical model based on the first law of thermodynamics for assessing the specific work produced by thermomagnetic motors utilizing first and second-order magnetocaloric materials. After initial verification of the results against data from open literature for the ideal Ericsson and Brayton cycles, the model then explores the impact of losses and irreversibilities on the output work. It was found that internal demagnetizing fields reduce the available work up to 42% for the simulated conditions, while heat losses and magnetic hysteresis are complex to implement and show minor impacts. Thermal hysteresis, in turn, may enhance the specific work, but prolong cycle periods. The model provides a cost-effective means to compare magnetocaloric materials and evaluate motor performance, aiding in component selection for thermomagnetic motors.

Switched capacitor and coupled inductor based high power factor charger for E-2/E-3 wheelers

This paper introduces a modified Zeta converter topology designed specifically for charging low voltage electric vehicles (LVEVs), enhancing performance for electric two (E-2) and electric three (E-3) wheelers. Unlike traditional Zeta converter, which offers buck-boost gain, an AC-DC converter in this study, utilizes a switched capacitor configuration to efficiently step-down voltage in a single phase, bridging the gap between the AC grid and low potential battery assemblies. This design incorporates a coupled inductor structure and operates in discontinuous inductor current mode (DICM), reducing the size of magnetic components and overall dimensions of converter and power factor correction (PFC) rectifier. DICM operation provides intrinsic PFC and minimizes switching losses, ensuring exceptional grid-side performance with unity power factor and minimal input current harmonic distortions, while maintaining an optimal battery charging profile. The meticulously developed hardware prototype, rated at 450 W, features precise component selection and carefully designed modes of operation. Performance analysis reveals a converter peak efficiency of 94.7 %, total harmonics distortion (THD) in input current at 2.7 % under rated conditions, and near unity power factor with zero phase displacement between input voltage and current.

NGHIÊN CỨU XÂY DỰNG THIẾT BỊ Y TẾ HỖ TRỢ THEO DÕI TỪ XA CHO BỆNH NHÂN TIM MẠCH

This article focuses on researching and developing a medical support device with functions to monitor various health parameters of patients directly or remotely, such as body temperature, heart rate, and blood oxygen saturation. The implementation method includes designing algorithm diagrams, hardware circuit design, component selection, and building a display application on smartphones or a website interface that allows monitoring the parameters quickly and accurately. Actual testing initially showed that, the device essentially operates quite accurately according to the design and programming with many advantages such as: The system operates stably, meeting design requirements; Results can be monitored visually in a variety of ways and conveniently on LCD screen, App, Web; Each measurement data is saved with data security assurance; The system is evaluated to have minimal errors, low power consumption, and is cost-effective, along with the convenience of result monitoring, making it suitable for various user groups. Furthermore, the research results can serve as a practical model for students in the Biomedical Engineering field at educational institutions where there is currently a shortage of devices catering to learning needs.

Rational Design of Molecularly Imprinted Polymers for Curcuminoids Binding: Computational and Experimental Approaches for the Selection of Functional Monomers.

Molecularly imprinted polymers (MIPs) have emerged as bespoke materials with versatile molecular applications. In this study, we propose a proof of concept for a methodology employing molecular dynamics (MD) simulations to guide the selection of functional monomers for curcuminoid binding in MIPs. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin are phenolic compounds widely employed as spices, pigments, additives, and therapeutic agents, representing the three main curcuminoids of interest. Through MD simulations, we investigated prepolymerization mixtures composed of various functional monomers, including acrylamide (ACA), acrylic acid (AA), methacrylic acid (MAA), and N-vinylpyrrolidone (NVP), with ethylene glycol dimethacrylate (EGDMA) as the cross-linker and acetonitrile as the solvent. Curcumin was selected as the template molecule due to its structural similarity to the other curcuminoids. Notably, the prepolymerization mixture containing NVP as the functional monomer demonstrated superior molecular recognition capabilities toward curcumin. This observation was supported by higher functional monomer molecules surrounding the template, a lower total nonbonded energy between the template and monomer, and a greater number of hydrogen bonds in the aggregate. These findings suggest a stronger affinity between the functional monomer NVP and the template. We synthesized, characterized, and conducted binding tests on the MIPs to validate the MD simulation results. The experimental binding tests confirmed that the MIP-NVP exhibited higher binding capacity. Consequently, based on MD simulations, our computational methodology effectively guided the selection of the functional monomer, leading to MIPs with binding capacity for curcuminoids. The outcomes of this study provide a valuable reference for the rational design of MIPs through MD simulations, facilitating the selection of components for MIPs. This computational approach holds the potential for extension to other templates, establishing a robust methodology for the rational design of MIPs.

The Role of Different Total Water Level Definitions in Coastal Flood Modelling on a Low-Elevation Dune System

The present study investigates different combinations and methods for estimating the extreme Total Water Level (TWL) and its implications for predicting flood extension caused by coastal storms. This study analyses various TWL components and approaches and assesses how different methodologies alter flood predictions, with implications for warning systems and emergency responses. Using different combinations of individual TWL components, flood extension simulations were conducted using a hydrodynamic model in the Volano Beach area (Emilia-Romagna, Italy). A real coastal storm event was used as a reference for comparison. The findings indicate that the selection of individual TWL components and calculation methods significantly impacts flood extension predictions. The approaches, which involve calculating extreme values from a combined time series or the water level time series plus the extreme value of wave setup, yield the most realistic results, excluding the runup component. In comparison, the other combinations overestimate the flood. Incorporating hydromorphological models like XBeach could enhance the accuracy of runup estimations and improve the overall method reliability. Despite limitations such as runup estimation and the use of generic regional parameters, this study underscores the importance of the TWL combination selection in accurately predicting flood extents, emphasising the need for context-specific adaptations in environmental contexts.

A novel economic and technical dispatch model for household photovoltaic system considering energy storage system in “Duhok” City/Iraq as a case study

Photovoltaic (PV) systems harnessing solar power to generate electricity have gained widespread adoption worldwide due to clean innovations. The geographic position of the Kurdistan region, north of Iraq, is very favourable for the photovoltaic power generation system. In Duhok City, the average daily hours of sunshine per year are 8.5 h; this is a good point, which makes installing photovoltaic systems more interesting because the performance of PV systems depends mainly on solar radiation. This study analyses the design of a PV system that supplies electricity to households in Duhok City during the period when there is no general electricity considering the economic and technical dispatch aspects. The system is to be designed to power the household for 10 h (Grid-connected PV system) since it is assumed that the general electricity supply only lasts for 10 h per day. The system will be an alternative source of electricity to the local generators. The full design of the proposed system is implemented, so that the data on the electrical load and site radiations of a specific household at the site under consideration are collected during the design stages. Further, the technician's and economic evaluations are considered as well during each step of analysis and selection for system components. The cost estimate was based on the following data: the electrical load of the house is 6239.1 Wh/day, the electricity cost is $0.005 per Wh and the total investment amount is $3475. The ultimate outcomes, when juxtaposed with the local expenses of diesel generators and PV solar systems, indicate that within 4.5 years, PV solar systems will recoup their initial costs, providing a clean and noise-free energy source thereafter.

Optimizing Components Selection in Blended Learning: Toward Sustainable Students Engagement and Success

Selecting the most appropriate components for a blended learning course is a multifaceted challenge influenced by various criteria. The impact of these influential criteria on the design process is not always obvious. The aim of this study is to assist academics in designing sustainable and engaging blended courses by investigating the impact of these criteria on the selection of blended learning components. By selecting the right mix of components, academics can foster a sustainable and meaningful involvement of students in their learning process over time, ensuring that students’ engagement is both enduring and beneficial in achieving academic success. A modified Delphi survey was utilized in this study, involving the participation of eighteen experts experienced in instructional design and online teaching. The analysis primarily relied on quantitative methods, utilizing the mean (to indicate central tendency) and standard deviation (to measure dispersion) for presenting the experts’ responses. Additionally, qualitative analysis of experts’ comments provided deeper insights into their quantitative ratings. Findings indicate that face-to-face collaborative activities should be the preferred method of delivery for academics aiming to enhance students’ engagement and foster their higher-order thinking skills, which students often find challenging. However, this approach is most effective when the group size is manageable. For larger student groups, online collaborative work can be a suitable alternative, provided there is ample online resource support. The results also indicate that online self-paced learning can be advantageous for lower-order thinking learning outcomes, particularly in situations where teaching staff is limited.

An improved method planning path of an autonomous ground robot with using the MBD-RRT*FFT algorithm

The study analyzed the problems associated with planning the path of robots and increasing the accuracy and reliability of their guidance in real time. To solve this problem, a practical study was conducted, based on the obtained analysis, a modification of the asymptotically optimal BD-RRT*FT algorithm and was proposed and improved the MBD-RRT*FFT algorithm. was developed. Which, when applied in dynamic environments due to the use of multi-threaded computations, has better dynamic scheduling capabilities, and the use of Fitch's optimal search result selection algorithm provides a general tendency to choose the optimal straight-line path. To verify the effectiveness of the proposed algorithm improvement method, simulations were carried out using our own simulation program. A comparison of the MBD-RRT*FFT algorithm with other algorithms was carried out on three maps with an evaluation of performance indicators. In order to evaluate the behavior of the program, as well as to identify bottlenecks in the execution of the algorithm, the memory load of the decision-making system was monitored at all stages of the verification. This made it possible to see an increase in the consumption of memory resources by 12-15%, but taking into account the obtained results regarding the optimality and speed of calculations, conclusions were made regarding the minimal impact. Additional understanding of the need for careful selection of the hardware component of decision-making systems is provided. The scientific novelty of the method consists in the application of a scientific and methodological apparatus for improving the BD-RRT*FT algorithm, which ensured further development in terms of expanding and supplementing known data on algorithms with robot path planning and increasing accuracy and reliability in real time. The method includes methods of research, systematization and adjustment of new and previously acquired knowledge.

Engineered heart tissue: Design considerations and the state of the art.

Originally developed more than 20 years ago, engineered heart tissue (EHT) has become an important tool in cardiovascular research for applications such as disease modeling and drug screening. Innovations in biomaterials, stem cell biology, and bioengineering, among other fields, have enabled EHT technologies to recapitulate many aspects of cardiac physiology and pathophysiology. While initial EHT designs were inspired by the isolated-trabecula culture system, current designs encompass a variety of formats, each of which have unique strengths and limitations. In this review, we describe the most common EHT formats, and then systematically evaluate each aspect of their design, emphasizing the rational selection of components for each application.

Fault diagnosis method of rolling bearing based on MSSA-VMD algorithm

Abstract Early fault signals of rolling bearings are affected by environmental noise, which makes it challenging to extract fault characteristics. In this paper, a bearing fault diagnosis method based on Sparrow Search Algorithm (SSA) and Variable Modal Decomposition (VMD) is proposed to achieve adaptive signal decomposition and feature extraction. First, the fusion shock index is constructed based on the envelope spectrum pulse factor and correlation coefficient to measure the shock fault components. Then, the VMD parameters are adaptively optimized by the improved sparrow search algorithm MSSA, and the fusion shock index is established as the optimal modal component selection method of the fitness function. Finally, the envelope spectrum of the signal after noise reduction is analyzed to extract the fault characteristic frequency. By analyzing the bearing outer ring fault signal and inner ring fault signal under strong noise, the results show that this method can adaptively determine the mode number and penalty factor of VMD, effectively extract the fault signal characteristics, and realize rolling bearing fault diagnosis.

The Symmetric Dual Inductor Hybrid Converter for Direct 48V-to-PoL Conversion

This work introduces the symmetric dual inductor hybrid (SDIH) dc-dc converter topology, which is suitable for large conversion ratios where regulation is required, such as direct 48 V to point-of-load (PoL) applications. A dickson-type switched capacitor network is used to effectively produce two interleaved PWM outputs with a greatly reduced voltage amplitude relative to the input voltage, allowing the subsequent magnetic volume to be reduced while retaining modest switching frequencies. Distinct from related variations, part count is significantly reduced while both even and odd order switched capacitor networks can be used with straightforward split-phase control; allowing either network type to achieve complete soft-charging of all flying capacitors. Additionally, charge flow is uniformly distributed through all elements, with equal capacitor and inductor values being preferred. Subsequently this topology is expected to simplify component selection, improve electrical and thermal performance, and reduce cost. Furthermore, analysis is presented that calculates precise phase durations without making small ripple assumptions, revealing up to a 75% timing error in cases where either inductor or capacitor ripple is ignored. Finally, a discrete prototype validates this analysis and demonstrates very high measured power densities of 1,029 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , 754 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , and 663 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> for 48 V input and regulated output voltages of 3 V, 2 V, and 1 V, respectively, while switching at a frequency of 750 kHz.

Blockchain Technologies: A scrutiny into Hyperledger Fabric for Higher Educational Institutions"

Over the past decade, significant technological advancements have taken place, with a strong focus on systems designed to enhance the security and reliability of distributed data across various sectors, both public and private. Among these technological innovations, blockchain technology has emerged as a standout paradigm, offering unique characteristics that guarantee data security and reliability in different applications.The model presented represents a culmination of efforts that trace their origins to the Ethereum platform, restructured to align with Hyperledger Fabric. This transformation elaborated according to the comprehensive analysis of various Hyperledger frameworks involving segmentation, comparison, and selection of components that augment the model's conceptual foundation. The overarching objective of this article is twofold: firstly, to delve into the exploration of Hyperledger technology, substantiating the rationale behind the chosen implementation model, and secondly, to showcase the model's restructuring within the framework presented.A central facet of this article is a compelling case study that illustrates the transformative potential of blockchain technology in reshaping existing systems and processes. Specifically, integrating Hyperledger Fabric as an enterprise-grade technology underscores its role in facilitating the practical implementation of blockchain solutions.Ultimately, the primary contribution of this article lies in its endeavour to formalise knowledge surrounding blockchain technology applicability and to underscore its potential societal and organisational benefits. By presenting a well-structured model and a practical case study, this work aims to advance the comprehension of blockchain's relevance and capacity to drive positive change across various domains.

Rancang Bangun Sistem Transfer Liquid Berbasis Arduino Uno Menggunakan Sensor YF-S401

This article discusses the design of a liquid transfer system using a YF-S401 flow sensor and the evaluation of various calibration factors to create a reliable system. The research methods included water flow measurement, system component selection, system design, and workflow. The research results showed that a calibration factor of 50 was the optimal choice, showing good liquid transfer precision at a scale of 100 ml. However, testing at a scale of 200 ml and 300 ml showed suboptimal performance, especially in maintaining liquid transfer precision. Further development recommended in the selection of more reliable components, the improvement of the Arduino Uno program, and the implementation of technologies such as real time operating system (RTOS) to improve the accuracy of the liquid transfer system at larger scales. Overall, this research provides important insights for the development of automatic liquid transfer systems with a focus on precision in various measurement scales. Keywords—Liquid transfer system, Flow sensor, Calibration factor, Water flow measurement, Arduino Uno

Optimal intersurface stability for unicompartmental femoral component design with two pegs placed on the distal resection surface:5 mm peg length incrementand 10° peg inclination.

The present study aimed to identify the optimal design of the unicompartmental femoral component through parameter analysis and stability evaluation. A finite element (FE) analysis was applied to analyse and adjust the parameter combinations of the anterior tilt angle of the posterior condyle resection surface, the position of the peg, the length of the pegand the inclination angle of the peg, resulting in 10 different FE models. Setting three knee flexion angles of 8.4° (maximum load state during walking), 40° (maximum load state during stair climbing)and 90° (maximum load state during squatting exercise), quantitatively analysing the micromotion values of the bone-prosthesis interfaceand defining a weighted scoring formula to evaluate the stability of different FE models. The validity of the FE analysis was verified using the Digital Image Correlation (DIC) device. The errors between the FE analysis and the DIC test at three flexion angles were 5.6%, 1.7%and 11.1%. The 10 different femoral component design models were measured separately. The FE analysis demonstrated that the design with a 0° anterior tilt angle of the posterior condyle resection surface, both pegs placed on the distal resection surface, lengthened 5 mm pegsand a 10° peg inclination angle provided the best stability. The current study proposed a method for evaluating the stability of the femoral component design. The optimal intersurface stability design of the unicompartmental femoral component was achieved with two pegs placed on the distal resection surface, a 5-mm peg length incrementand a 10° peg inclination. These results might provide a reference for the selection of unicompartmental femoral components in clinical practice and therefore improve the survival rate of future unicompartmental knee arthroplasty. Level III.