EUREKA: Physics and Engineering

The modeling of changes in the specific activity of tritium in plants

2023-05-25T13:27:12+03:00

Birch juice is a drink made of birch sap of medium-sized wild trees at the springtime. It is popular especially in northern Europe and Asia on territories with occasionally waterlogged permeable soils. However, some of these areas coincide with highest tritium leakage ever recorded (Kyshtym, Chernobyl and Fukushima). Robust analyses on tritium levels (scintillation method) in the birch sap were carried out in location with a constant load of tritiated water between 2003 and 2016. Sampling the birch sap was carried out annually in season (usually from the final week of February to the first-week of April. Sampling of birch sap was usually has been carried out during the period when the daytime air temperature was within +(5–8) °C minimum for 3 days. During this period, began intensive sap flow. Data obtained is put in relation to air temperature and humidity in order to contribute to the understanding basic mechanisms of tritium intake via birch. Findings confirmed that tritium easily penetrates via water into any organism and it can accumulate there for much longer than its half-decay times. It was firstly revealed that it is possible to predict the concentration of this dangerous pollutant in the birch sap based on the temperature and humidity dynamics. And with continuous input of tritium into the environment, the concentration of tritium in free water increases polynomial. The specific tritium activity values due to the gradient of tritium concentration in the atmosphere-plant-ground system of the change in temperature and humidity. For the organization of monitoring and control, the possibility of radioecological safety for the affected areas was determined

A comparison study of the behaviors of single-phase turbulent flow at low to moderate Reynolds numbers through a vertical pipe: 3D counters analysis

2023-05-25T13:27:12+03:00

The study presented three-dimensional (3D) analysis of water's upward flowing through the vertical pipe under turbulent characteristic considerations. Both numerical constructed and improved the model of 3D for cylindrical coordinates of governing equations for incompressible turbulent flow with the Reynolds Average Navier-Stokes (RANS) model using the improved constants of the (k–ε) type. The present model is then compared with a previous study to give the feasibility of the present single-phase turbulent flow parameters. The pipe length is tested to measure how much it affected the turbulent parameters though one of the expected factors is the turbulent time scale. On the other hand, the model is numerically examined to determine the velocity profile, shear rate, and surface deformation of the water domain. While the pressure distribution, turbulent kinetic energy, and turbulent dissipation rate, these parameters are classified as the mechanic's system factors. The simulation is done with wide software used to simulate industrial is COMSOL 5.4 Multiphysics software. The results obtained increased the velocity of three inlet water velocities used ranging from (0.087, 0.105, and 0.123 m/sec) of upward flow. High fluctuation in the water flow moves along the entire pipe length and it can notice the sensitivity to any change in water properties or mechanical properties. The liquid upward flow in turbulent conditions is suffered from many characteristics such them related to liquid properties and others related to the mechanics of the application through the systems. The interaction between the fluid film (fluid boarded the pipe inner diameter) has been observed by the shear rate and liquid surface deformation

Improving the maneuverability of vehicles by using front swivel axles with separate electric wheels

2023-05-25T13:27:12+03:00

There is a need for vehicles to maneuver when there are traffic jams, to overcome narrow streets and various obstacles. This leads to increased requirements for dynamism and maneuverability of vehicles.

The authors present the results of the development and research of the steering control of the vehicle, which provides increased maneuverability. Such circumstances significantly affect the increase in maneuverability of wheeled vehicles, including tractors, for which the use of front suspension axles is possible in terms of layout. The use of a front swing axle with electric motor-wheels with separate control will increase the maneuverability of a two-axle vehicle and minimize the steering effort when turning.

When solving the task, a mathematical model of the movement of the vehicle on a turn was created. The forces in the contact of the wheels with the road surface were determined, which made it possible to determine the forces and moments of resistance to the rotation of the front axle. Rational laws of control of turning the front axle, providing minimal resistance to the movement of the vehicle, were obtained.

A vehicle turning control option is proposed, in which the wheels of the outer and inner sides are alternately braked when the vehicle enters and exits the turn. In addition, it is possible to alternately create a torque difference on the wheels of the outer and inner sides of the front axle. Using the proposed turn control options, it is possible to create a multi-axle vehicle with a rocking axle.

The materials of the article on the controllability of vehicles depending on the design of the steering and front axle are of interest to researchers, designers of mobile equipment, graduate students and students of engineering specialties

The technical assessment of the level of innovative traction transmission of railway vehicle

2023-05-25T13:27:12+03:00

The article deals with the development of an innovative model of traction transmissions of railway vehicles with a higher technical level, which allows to eliminate the existing shortcomings of the mechanical system, simplify the repair processes and reduce the cost, and evaluate its technical level. By reducing the overall dimensions and weight of the mechanical system, increasing reliability due to equal distribution of the load and shortening the power arm, as well as reducing the number of structural elements, increasing the useful work coefficient due to the reduction of the mass of double sliding pads and rotating parts, saving electricity and thereby improving the technical level of rail transport. Traction transmissions consisting of an innovative reducer are offered that ensure the increase.

The technical level of the proposed dart transmission is determined based on three compatibility parameters with a creative approach. Compatibility parameters are determined according to the minimum value of the geometric dimensions characterizing the mass of the mechanical system, the maximum value of the useful work coefficient characterizing economic efficiency, as well as the maximum values of the degree of reliability characterizing safety. The technical level of the proposed project transmitter is determined and compared with existing buildings, its technical and economic advantages are highlighted. As a result of the application of the proposed innovative reducers in the traction drives of railway vehicles, the basis is created for reducing the cost and maintenance costs of traction vehicles, increasing the level of traffic safety, as well as improving the traction and braking characteristics

Design and simulation of automotive radar for autonomous vehicles

2023-05-25T13:27:12+03:00

Modern automobile technology is pushing towards maximizing road safety, connected vehicles, autonomous vehicles, etc. Automotive RADAR is core sensor technology used for ADAS (Advanced Driver Assistance Technology), ACC (Adaptive Cruise Control), AEB (Automatic Emergency Braking System), traffic assistance, parking aid, and obstacle/pedestrian detection. Despite being inexpensive, RADAR technology provides robust results in harsh conditions such as harsh weather, extreme temperature, darkness, etc. However, the performance of these systems depends on the position of the RADAR and its characteristics like frequency, beamwidth, and bandwidths. Moreover, the characterization of varied materials like layers of paint, polish, primer, or layer of rainwater needs to be analyzed. This performance can be predicted through real-time simulation using advanced FEM software like Altair FEKO&WinProp. These simulations can provide valuable insight into the performance of the system, allowing engineers to optimize the system for specific use cases. For example, simulation can be used to determine the optimal parameters of the RADAR system for a given application. This information can then be used to design and build a physical model or prototype that is optimized for the desired performance. These simulations play a prominent role in determining appropriate data collection and sensor fusion, which reduces the cost and time required for the development of a physical model or prototype. The continued growth and demand for advanced safety features in vehicles further highlight the importance of RADAR technology in modern automobile technology. By accurately characterizing the environment and simulating the system's behavior in real time, engineers can optimize RADAR systems for specific use cases, contributing to safer and more efficient driving experiences

Smart automated fish feeding based on IoT system using LoRa TTGO SX1276 and cayenne platform

2023-05-25T13:27:12+03:00

One type of aquaculture that is commonly found in Indonesia is freshwater fisheries in the form of densely stocked fish ponds. An important factor that supports the success of this aquaculture is an appropriate and scheduled feeding system the fish. To address this problem, this paper proposed a smart automation system was designed and implemented to perform feeding management with solar panel as the power. To enhance the productivity of the fish, this paper proposing a new contribution based on Internet of Things (IoT) solution that could control and monitoring the schedule time and amount of feeding and the food behavior of fish. This system is accessed through the Cayenne website and using LoRa TTGO SX1276 to microcontroller and it showed that the schedule and amount of feed was successful with a high accuracy and the panel system also worked well in monitoring and controlling the power system. From the results of testing the entire system, it can be concluded that the feeding automation system can help optimize the productivity of freshwater aquaculture, and provides an innovative solution which user-friendly, secure, scalable, low cost and go green, reliable

The design of a fully balanced current–tunable active RC integrator

2023-05-25T13:27:12+03:00

The design of the active RC integrator presented in this research utilizes a fully balanced technique and current-tunable frequencies to create the active RC integrator and reliable circuit. The circuit is made up of six npn bipolar junction transistors (BJT), six resistors (R), and a capacitor (C), with the fully balanced technique used to make the circuit structure uncomplicated and symmetrical with signal differencing. This approach results in a low number of internal devices in the circuit, making it an attractive option for integrated circuit (IC) development. One of the key features of the fully balanced current-tunable active RC integrator is its ability to be frequency-tunable with bias current (I_f). This feature enables the circuit to be used in a variety of applications, including filter circuits, communication signal generators, instrumentation signal generators, and various automatic controls. The fully balanced design also ensures that the circuit is stable and robust, even in the presence of device parameter variations. To evaluate the performance of the active RC integrator, simulations were conducted using Pspice.

The results show that a fully current-tunable active RC integrator can be precisely tuned with the active bias to a value consistent with the theoretically calculated value. This demonstrates the efficiency and reliability of the circuit design and simulation method. The Monte Carlo (MC) method was also used to analyze the circuit performance in cases where the resistor (R) and capacitor (C) device had a 10 percent error and the transistor gain (β) was set to an error of 50 percent. The MC analysis showed that the phase shift (degree) and magnitude (dB) of the circuit were stable, and the circuit's performance was not significantly impacted by the device parameter variations. This further demonstrates the robustness and versatility of the fully balanced current-tunable active RC integrator design. Finally, harmonic distortion was evaluated to confirm the performance of the designed and developed fully balanced current-tunable active RC integrator. The results showed low levels of harmonic distortion, which indicates that the circuit is suitable for high-performance applications that require low distortion

Research to determine the best value of both Z and OVC in micro-EDM using carbon coated electrode using topsis method

2023-05-25T13:27:12+03:00

In the machining process, it is difficult to solve problems due to the relationship between productivity and quality, for example, as the productivity increases, the quality of reprocessing may decrease. Some methods only address specific objectives, such as the quality of the machining method, the machining productivity, the quality, or even the cost. Electrical discharge machining (EDM) and micro-EDM are most commonly used for processing the surfaces of die and moulds. The amount of electrode wear in micro-EDM has a direct effect on the dimensional accuracy of the machined hole. Therefore, improving the corrosion resistance of electrodes in micro-EDM is still of great interest. The effective coating of thin film for the micro tool electrodes in the case of micro – EDM can lead to minimize the electrode wear which eventually improve the productivity and machining quality. In the present study, experiments were performed on micro – EDM using carbon coated tool electrode and optimized using Taguchi-Topsis to investigate optimum levels of Depth of cut (Z) and overcut (OVC). It was concluded that optimum conditions had improved significantly using carbon coated micro tool electrode. Optimal levels of technological parameters include V=160 V, C=10000 pF, RPM=400 rpm, and Zopt=2,525 mm, OVCopt=72,856 μmm. The quality of the machined surface with the coated electrode at optimal conditions is analyzed and evaluated. The Topsis method is a suitable solution to this problem, and the steps to perform the calculation in this technique are simple

Optimization of technological parameters in ultrasonic welding of the polypropylene fabric using Taguchi and FCCCD methods

2023-05-25T13:27:12+03:00

Ultrasonic welding is a welding method that has been applied for welding nonwoven fabrics, with many advantages such as fast speed, high reliability, easy automation and especially less pollution to the environment. This paper studies the optimization of technological parameters in the welding process such as welding time, pressure, and weld shape on the breaking strength of ultrasonic welding of Polypropylene (PP) nonwovens. To evaluate the influence level and find the reasonable technological parameters domain in the paper, the Taguchi method is used in combination with the face-centered central composite design (FCCCD) response surface method. The research results have determined the regression equations used to calculate the breaking strength for each weld shape as well as the optimal domain for the main technological parameters, ensuring the breaking strength of the weld. There are different degrees of influence of technological parameters (shape of the weld zone, welding time and welding pressure) on the breaking strength of ultrasonic welds. Among them, the influence level of welding time t is 45.31 %, the weld shape is Pattern 2 with the rate of 30.03 %, and the welding pressure is 24.66 %. Carrying out a verification test with the welding parameters: t=1.6 s, p=3.1 kgf/cm², two patterns ( Pattern 2 and Pattern 3), the result of breaking strength for patterns was achieved. Pattern 2 has a difference of 1.19 % between the regression equation results and the actual experimental results, while the figure for Pattern 3 is 0.77 %. From these results, it is possible to select the appropriate technological parameters for ultrasonic welding equipment when processing products from nonwoven fabrics to ensure the highest quality and productivity

Development of mechanical property prediction model and optimization for dissimilar aluminum alloy joints with the friction stir welding (FSW) process

2023-05-25T13:27:12+03:00

Friction stir welding (FSW) is a solid-state joining process used to weld dissimilar aluminum alloys with varying material properties and compositions. Unlike traditional welding methods, FSW does not involve melting the materials being welded but instead uses a rotating tool to heat and stir the materials until they are in a plastic state. The process results in a welded joint with high strength, excellent ductility, and minimal distortion, making it a popular choice in various industries, including aerospace, automotive, and marine. AA6061-T6 (Mg-Si) and AA7075 (Al-Zn-Mg-Cu) aluminum alloys are one of the most popular grades of aluminum alloys used in current manufacturing industries, such as aerospace and automotive, joined by the Friction Stir Welding Process (FSW) technique. Taguchi orthogonal array (L9) experimental design was applied to reduce the number of insignificant factors in the process. First, the study determines three welding factors: rotation speed, travel speed, and pin eccentricity. Investigations found that travel speeds significantly on tensile strength (Ts) and elongation ( %El), but the rotational speed and tool eccentricity did not affect Ts and %El. Furthermore, considering the fabricated parameters on the hardness (HV) of the joint, it was found that all factors unaffected the HV of the joint zone at a 95 % confidence level. Next, examine the microstructure; Mg₂Al₃ and Al₂O₃ intermetallic compounds were found in the weld. Therefore, investigating the crystallite size found that welding significantly affects the crystallite size. Finally, consider the fracture surface, experimental condition A₂B₁C₂ (optimal parameter), which is the parameter with the highest tensile strength having dimple fracture characteristics. On the other hand, the welding condition A₁B₃C₃, the parameter with the lowest tensile strength, Small and fine dimple fracture with cleavage fracture. Because the material is highly ductile and can undergo large deformations before it is damaged. On the other hand, materials with low tensile strength exhibiting cleavage fracture indicate that the materials are brittle and can break easily under stress

Design, analysis and construction of a simple pulse duplicator system

2023-05-25T13:27:13+03:00

One of the most important human diseases that need to be considered in terms of development of the medical engineering devices is cardiovascular disease which is a significant cause of death globally recently. Valvular heart disease is normally treated by restoring or altering heart valves with an artificial one. But the new prosthetic valve designs necessitate testing for durability estimate and failure method. It is significant to simulate the circulation system by the building of a pulse duplicator system. This study is stated by clarifying the parameter and implementation steps of the pulse duplicator system in which the different researchers have utilized the system and tried to explain the design steps of using this system without going into the system design by steps or what are the main part of this system and how can be implemented, tested, and developed individually.

In this design, a DC motor produces, through a hydraulic piston, a flow pulse to the left ventricle chamber model, which is linked with two interchangeable prosthetic heart valves. The computer is used to control and process data from volumetric flow rate and image. The findings show that the linear displacement, the velocity of the piston and the linear acceleration regularly become significant particularly and follows a sinusoidal wave shape during one cycle, when (crank length/connecting rod length) value is equal 0.2 or less. Several sets of measured flow rate readings were obtained by using flow meter sensor YF-S201, results after calibration showed the error rate falls within permissible limits

The development of cognitive workload management framework based on neuronal dynamics principle to maintain train driver’s health and railway safety

2023-05-25T13:27:13+03:00

Fatigue increases the tendency of poor train driving strategy decision. Decision making in cognitive overload and cognitive underload situation mostly outputs bad decisions. Accordingly, train driver’s cognitive function is required to be sTable during travel so that they can give correct response at a given situation. This study constructs a conceptual framework for cognitive workload management (CWM) of train driver by taking the energy expenses from cognition into the account. This study combines objective and subjective cognitive workload analysis to evaluate train driver duty readiness. The objective load analysis was performed through energy level approximation based on neuronal dynamics simulation from 76 brain regions. The cognitive energy expenditure (CEE) calculated from neuron action potential (NAP) and the ion-membrane current (IMC) from the simulation results. The cognitive load (CL) approximated by converts the continuous time-based CEE to discrete frequency-based CL using Fourier series. The subjective cognitive workload obtained from train simulation results followed by 27 participants. The participants fill the questionnaire based on their simulated journey experience. The results of the evaluation used to build readiness evaluation classifier based on control chart. The control chart evaluation helps the management to determine weekly rest period and daily short rest period treatment base on each train driver workload. The CWM framework allows different recovery treatment to be applied to each train driver. The impact of the CWM application is the performance of train drivers are kept stable. Thus, the CWM framework based on CEE is useful to prevent physical and mental fatigue

Effect of particle size on ignition and oxidation of single aluminum: molecular dynamics study

2023-05-25T13:27:13+03:00

Alumina nanoparticle is one of the attractive nanoparticles synthesized by the plasma method. The oxidation step in this method is challenging to explain experimentally. This work was to perform a molecular dynamics simulation to determine the oxidation mechanism of aluminum nanoparticles with different sizes and oxidation levels in the oxide layer. This work was to perform a molecular dynamics simulation to determine the oxidation mechanism of aluminum nanoparticles with different sizes and oxidation levels in the oxide layer. The simulation method employed the ReaxFF potential. The material used is aluminum nanoparticles in three different sizes (8, 12, and 16 nm) with an oxide layer thickness of 0.5 nm. Aluminum nanoparticles were given a relaxation treatment of 300 K for 1 ps and then heated to a temperature of 3250 K with a heating rate of 5×10¹³ K/s and cooled to 300 K. The ensemble used is a canonical ensemble with the Nose/Hoover thermostat method. The result shows that the higher the temperature applied to the system, the more oxygen molecules adsorption occurs on the surface of the oxide layer and the diffusion of oxygen to the particle core. The higher temperature applied also causes gaps, or void spaces, between the core and the shell. The reaction barrier for diffusion of oxygen also decreased significantly due to void space, and the surface of the aluminum core dissociates to the surface (alumina shell). Particles with a smaller size have a shorter ignition delay time. In addition, the smaller the particle size, the more oxygen molecules' reacted with aluminum particles in the particle core

Investigation on high-strength low alloy 0.35Cr-1.9Ni-0.55Mo steel deposited on 20Cr substrate by wire and arc-based directed energy deposition

2023-05-25T13:27:13+03:00

This article aims to observe the microstructure, mechanical properties, and interface bonding of a 0.35Cr-1.9Ni-0.55Mo alloy deposited on 20Cr steel by wire and arc-based directed energy deposition (WA-DED). For this purpose, different characterization techniques such as optical microscope, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and high-resolution X-ray diffractometer were used to analyze microstructure, chemical composition, and phases of the deposited material. Microhardness and tensile tests were also carried out. The results show that the microstructure of the deposited material is relatively homogeneous with a slight increase in grain size from the bottom to the top of the deposited part, thus resulting in a gradually decreasing trend in microhardness, from 288±16.78 HV0.1 (in the bottom) to 256±17.04 HV0.1 (in the top). The heat-affected zone (HAZ) is the hardest (301±2.70 HV0.1), while the substrate has the lowest microhardness (203±17.64 HV0.1). The tensile strengths of deposited materials are relatively isotropic in both the horizontal direction (HD) and vertical (VD) direction: UTS_VD = 1013±9.29 MPa, UST_HD = 985±24.58 MPa, YS_(0.2%)VD= 570±4.51 MPa, and YS_(0.2%)HD = 614±19.66 MPa. The tensile strengths of interface specimens are also comparable to those of the substrate materials (e.g., 951 vs. 972 MPa in UTS), indicating an excellent metallurgical bonding between the deposited and substrate materials. The results of this work confirm the efficiency of WA-DED technique to produce high-quality components in industry

Hybrid kalman filtering algorithm with wavelet packet data processing for linear dynamical systems

2023-05-25T13:27:13+03:00

The paper develops a hybrid algorithm for predicting a linear dynamic system based on a combination of an adaptive Kalman filter with preprocessing using a wavelet packet analysis of the initial data of the background of the system under study.

Being based on Fourier analysis, wavelet analysis and wavelet packet analysis are quite acceptable for time-frequency analysis of a signal, but they cannot be performed recursively and in real time and, therefore, cannot be used for dynamic analysis of random processes. In combination with the Kalman filter, a combination of the characteristics of the multiple-resolution wavelet transform and the recurrent formulas of the Kalman filter in real time is obtained.

Since the original signal is usually given in the form of discrete measurements, to implement their convolution used in the Kalman filter, it is necessary to use cyclic convolutions with periodic continuation of the signal for any time interval. In the case of different values of the original signal at the ends of the considered time interval [0,T], the periodized signal can have large values and sharp different amplitude at the ends of the periodization interval.

To smooth out the values of the periodized signal at the ends of the periodization interval, a cascade decomposition and recovery algorithm was used using Dobshy boundary wavelets with a finite number of moments. Signal recovery is performed in a series of operations comparable to the duration of the time interval under consideration.

The smoothed signal obtained in this way is used as a Kalman filter platform for predicting the dynamic system under study.

Taking into account that the correlation functions of the noise in the observation equation and the phase state of the system are usually unknown, the adaptation of the Kalman filter to these noises (interference) is carried out on the basis of a zeroing sequence. The manuscript does not contain related data

The development of the solution search method based on the improved bee colony algorithm

2023-05-29T10:31:43+03:00

Active digitization of people's daily life leads to the use of the decision-making support systems (DMSS). DMSS is actively used in data processing, forecasting the course of various processes, providing informational support for the decision-making process by decision makers. However, a number of problems arise while evaluating monitoring objects, namely: a large number of destabilizing factors affecting the efficiency of the processes of information collection, processing and transmission; high dynamism of changes in the state and composition of heterogeneous monitoring objects during the conduct of hostilities (operations); high dynamism of conducting hostilities (operations); the uncertainty of the initial situation and the noise of the initial data. In this article, a method of finding solutions based on an improved bee colony algorithm was developed.

The efficiency of information processing is achieved by learning the architecture of artificial neural networks; taking into account the type of uncertainty of the information to be evaluated; the use of an improved algorithm of the bee colony, the use of an unordered linguistic scale of measurements with adjustment coefficients for the degree of awareness and the degree of noise of the initial data. An approbation of the use of the proposed method was carried out on the example of assessing the state of the operational grouping of troops (forces). The method is proposed to be used in the development of software for automated systems of control of troops and weapons, namely, in the modernization of existing and development of new automated systems of control of troops and weapons. The evaluation of the effectiveness of the proposed method showed an increase in the efficiency of the evaluation at the level of 21–28 % in terms of the efficiency of information processing

Enhancing an image’s compression while keeping quality standards utilizing new mathematical technology

2023-05-25T13:27:13+03:00

The rapid development of technology led to the need to keep pace with it, especially in the field of image processing, because of its importance in the need to get better results. In this paper, new discrete Chebyshev wavelet transforms (DChWT) derived from Chebyshev polynomials (ChP) were proposed and characterized. In terms of orthogonality and approximation (convergence) in the field of mathematics, (ChP) were qualified to transform into discrete wavelets called (DChWT), depending on the mother function with operators (s, r), and were used in image processing to analyze them in the low filter and the high filter so that the image is analyzed into coefficients. Proximity and detail coefficients, which lead to dividing the image into four parts, low left (LL), in which the proximity coefficients are concentrated while the rest of the parts are centered on the detail coefficients, which are high left (HL), low right (LR), and high right (HR), and image compression through the new filter, which has proven its efficiency at level (8) in our results. The results of the proposed wavelets in this work were reached in calculating quality standards in the image obtained after the compression process after comparing them with the results obtained using the standard wavelet used in HaarSymlet 2, Conflict 2, and Daubecheis 2. The most important of these standards is a mean square error (MSE), peak signal-to-noise ratio (PSNR), bit per pixel (BPP), compression ratio (CR), and table one. In this paper, the efficiency of the proposed new wavelets is explained after adding it to MATLAB and according to a specific program to drop in with the basic wavelets to take on their role in important tasks in the image processing area, like artificial intelligence