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This paper presents the results of a study of the effect of ultrasonic and ultrahigh-frequency treatments on the structure and adsorption index of the organic dye methylene blue bentonite of the Republic of Tatarstan. It was found that ultrasonic treatment of an aqueous suspension of bentonite reduces the average diameter of its particles by 4 times and increases the adsorption capacity by 20% due to an increase in the specific surface area and the formation of a homogeneous structure. The optimal mode of ultrasonic treatment: the treatment time is 3 minutes, the frequency is 20 kHz, the ratio of bentonite and water is 1:1.2, the settling of the suspension before treatment is 12-16 hours. Based on the comparison of various modes of ultrasonic exposure, it is shown that the efficiency of dispersion of solid particles in the liquid phase depends more on its intensity per unit volume of the treated bentonite suspension. With ultrahigh-frequency treatment of bentonite lasting 4 minutes and a power of 750 Watts, the adsorption index increases by 5% due to the expansion of the adsorption space by removing adsorbed water. It is confirmed by a change in the surface structure of bentonite particles and a decrease in the interplane distance in the layered mineral montmorillonite from 15.05 Å to 12.71 Å. Ultrahigh-frequency treatment, compared with thermal treatment, makes it possible to significantly intensify the processes of dehydration of layered bentonite minerals up to 7.5 times when higher values of adsorption of organic molecules of the methylene blue dye are achieved. The paper presents diagrams of the density distribution of bentonite particles, the microstructure of bentonite before and after treatment with an ultrahigh frequency electromagnetic field, and X-ray phase analysis data. [ABSTRACT FROM AUTHOR]

This paper explores the characteristics of heterogeneous reactions occurring during the release of gas bubbles upon contact with a solid reducing agent. The investigation considers the hydrodynamics and heat/mass transfer features involved in the reduction reaction within the coke zone of an ore-thermal furnace. The complexity arises from the presence of a gas phase bubbling through the melt. The conditions created by the formation of bubbles enhance mixing, thereby activating chemical and metallurgical reduction processes. A fundamental element of the reaction involves the reagent actively diffusing due to vigorous mixing, causing a transition of the reduction process into the kinetic domain. Key considerations at this juncture encompass the temperature within the reaction zone and the concentration of the reagent. The interplay of the reduction reaction and the creation of gas bubbles affects the development of convective currents, with their formation being influenced by both temperature and reagent concentration. [ABSTRACT FROM AUTHOR]

This paper examines the stress-strain state of a pipeline inspection window made of polymethyl methacrylate (PMMA). Two cases are considered: without a defect in the thickness of the body under consideration; taking into account a small defect near the inner wall. The problem reduces to the Lamé problem, taking into account the physical nonlinearity of the material. Analytical estimates of the principal stresses in a cylindrical coordinate system for a defect-free body are given. Based on the obtained estimates, a numerical solution to a similar problem was verified using COMSOL Multiphysics. The problem of the influence of a defect on the stress-strain state of a body was solved numerically, taking into account the physical nonlinearity of the material, and the dependence of the safety factor on the position of the spherical cavity was shown. [ABSTRACT FROM AUTHOR]

The paper presents solutions for selecting controllers for boiler houses and heating networks. It is shown that controllers are highly specialized in performing functions specific to the requirements for heating networks. Specialization can be seen at all levels - from input-output characteristics, microprocessor characteristics and data visualization and alarm signals on the computer panel. Among the selected functions, the functions of ensuring the operation of controllers according to the seasons "Winter - Summer", as well as the choice of modes in order to simplify control tasks, stand out. An important requirement for network controllers is low cost and the ability to operate the controller by a low-skilled user. Using the example of Vitotronic and Segnetics controllers, the implementation of the requirements for the selection of controllers for boiler houses and heating networks is demonstrated. [ABSTRACT FROM AUTHOR]

The paper is devoted to solving the Neumann boundary value problem for the Poisson equation in an elliptic body. In this case, heat transfer occurs under boundary conditions of the second kind. Based on the methods of differentiation and integration, a solution was obtained to the problem of the distribution of the temperature field of the body under study. The resulting solution has an analytical form containing hypergeometric and hyperbolic functions. The reliability of the obtained result is confirmed by the fact that the general solution of the problem coincides with the solution obtained in one of the author's works for the case of a temperature field distribution in a body with an elliptical cross section of infinite length under boundary conditions of the third kind. [ABSTRACT FROM AUTHOR]

The paper deals with innovative building materials which, in the future, should significantly reduce construction time and significantly reduce heat and electricity costs. These materials have a unique production technology, are among the most environmentally friendly, and their composition and novelty have been confirmed by patents. They are produced under conditions that do not harm the environment. Manufacturers of new materials today rely on the ease of use of products with high performance characteristics, as a result, it is possible to change both the process itself and the general trend in construction. The authors have provided a comparative description and classification of modern building materials that are popular at the current stage of construction and will be used in the foreseeable future. [ABSTRACT FROM AUTHOR]

The paper considers a model problem of the thermal diffusion process in a silicon wafer. The mathematical model of this process is an initial boundary value problem for a system of linear partial differential equations of parabolic type. In this system, one equation describes the process of heat propagation in silicon in the presence of internal heat sources, and the other describes the process of diffusion of impurities in it. Moreover, these equations are related in the same way that the diffusion coefficient of an impurity depends on temperature. A special form of the volumetric heat release function was considered, which made it possible in this particular case to write down an explicit solution in the form of a Fourier series. To find an approximate solution to the boundary value problem, an implicit difference scheme and the classical sweep method are used. A computational experiment is presented. [ABSTRACT FROM AUTHOR]

The authors of the article propose to increase the efficiency of waterjet cutting of materials by reducing the hydrodynamic resistance in the nozzle channel during jet formation by adding multifunctional surfactants simultaneously with abrasive feeding. The paper shows the mechanism of surfactant layer formation on the metal surface of the wall of the focusing tube wall of the nozzle of the waterjet machine. [ABSTRACT FROM AUTHOR]

The authors provide an insight into the process of creating a vehicle, from conceptual idea to finished product. They analyze various aspects of its engineering, including the choice of materials, manufacturing techniques and design. The main objective was determined by the need to improve the design and performance, which was identified using available rental and other models. This paper describes the stages of preparation, design, test, improvement and further use of a homemade velomobile type vehicle. As a result of the work it was possible to create a four-wheeled, electric-powered transport with increased characteristics of strength, speed, handling and others. The operational experience of both the project team and focus groups is described. The authors propose their suggestions for the possible future construction improvements. The research results may be useful for experts in the field of bicycle and car engineering, as well as for students and academics of relevant technical disciplines. [ABSTRACT FROM AUTHOR]

The paper presents the results of studies to determine the dependence of porosity of gas-thermal coatings on laser radiation parameters. On the basis of analytical dependences the effect of laser radiation on the surface layers of gas-thermal coating is described. Its discontinuity caused by the presence of open and closed pores was taken into account. It is shown that to reduce the porosity of the coating under the influence of laser radiation it is necessary to create on the surface of the coating the temperature in the interval "melting temperature - boiling temperature". Increase of temperature caused by increase of radiation intensity above the specified range leads to evaporation of surface layers of the coating up to its complete removal in the zone of thermal influence. Laser treatment of pre-sprayed gas-thermal coatings based on and non-metallic (Al2O3) components was carried out in the course of experimental studies. Quantitative estimation of porosity change was performed with the help of image processing program developed in Visual Studio 2008 environment by means of pixel-by-pixel comparison of areas occupied by pores and coating material in the microstructure image. It was found that the laser radiation exposure leads to a decrease in the average porosity of gas-thermal coatings from 24.5 % in the initial state to 15-18 % after laser treatment. [ABSTRACT FROM AUTHOR]

This work is devoted to the development of a method for optimal load distribution between units of thermal stations using geometric programming. Load distribution problems for thermal power plants, including turbines, boilers, units and other components, are complex and relevant in the context of energy systems. The paper discusses optimization features for condensing turbine units, blocks and boilers. The use of geometric programming makes it possible to simplify the conditions for the most favorable distribution, providing effective methods for solving the problem. The developed method not only provides optimal load distribution, but also takes into account various technical characteristics and limitations of plant components. The results of the study represent a significant contribution to the field of optimization of energy systems, and the proposed method can be effectively used in practical problems of controlling thermal power plants to improve their efficiency and reliability. [ABSTRACT FROM AUTHOR]

Power systems facing dynamic and nonlinear characteristics require effective optimization techniques to ensure stability, efficiency, and controllability. This paper proposes a method for optimizing power systems using a genetic algorithm that takes into account complex relationships in the power infrastructure. The genetic algorithm provides a flexible and versatile means for global optimization, providing robustness to local minima and adaptation to system dynamics. The method was applied to optimize the energy balance, minimize costs and take into account the nonlinear characteristics of the power system. Experimental results validated the effectiveness of the proposed method, demonstrating energy balance and high accuracy while accounting for complex system characteristics. However, further research is required to improve the method, including a more in-depth analysis of the influence of algorithm parameters and consideration of additional uncertainty factors. This research provides valuable insights into the field of power system optimization and provides a basis for the development of more effective control techniques in complex and dynamic energy environments. [ABSTRACT FROM AUTHOR]

The paper substantiates the use of a non-contact method for estimating linear expansion under thermal influence. The basic optical scheme of the interferometer has been developed and its 3D model has been created. Tests were carried out to determine the arithmetic mean of the linear thermal expansion: the variance, the mean square deviation and the confidence interval were calculated. An algorithm and a layout of a hardware and software complex for measuring changes in linear dimensions in a non-contact manner, in which the movement of the controlled surface is controlled by means of a laser interferometer, has been developed. [ABSTRACT FROM AUTHOR]

The paper examines optimization problems for underground structures based on algorithmic methods, develops mathematical models, and specifies algorithms for solving them. Solving these problems allowed us to achieve significant savings in materials and costs compared to existing projects. The possibility of designing vault structures with minimal consumption of materials is being explored. The results of calculations for the optimization of underground structures are presented. [ABSTRACT FROM AUTHOR]

LOFAR (Low Frequency Array) is a radio telescope consisting of two types of antenna arrays – for low and high frequency. In this paper we discuss the High Band Array – HBA and represent option to better its accuracy, using the FEM (Finite element method), that can help us increase the precision of the modeling of antenna elements in large antenna arrays, which is the case of the HBA. [ABSTRACT FROM AUTHOR]

In this paper, the Intensity of the Characteristic Q-learning (InCh Q-learning) algorithm is proposed. It allows for finding the shortest and at the same time the safest escape route. Data on the intensity and spread of a fire occurring in a virtual electrical substation are used. Matrices are entered with the intensity values of each considered fire characteristic. As the fire spreads in space, zones of intensity are formed. Rules are introduced that take into account intensity zones for finding an escape route. The learning algorithm finds the shortest path for which the intensity of each of the dangerous features is the least. A threshold of the intensity of each character is introduced at which a person can pass and evacuate successfully. The use of priorities for the dangerous features allows one to choose a path with a greater intensity of the safer features and at the same time with a lower intensity of the more dangerous ones. The optimal escape route found is used to build a decision tree to find the location of an injured user as quickly as possible. [ABSTRACT FROM AUTHOR]

The examined pollution sources in the current paper include combustion and industrial processes; agriculture; household heating; waste and waste water treatment; road, rail and aviation transport. The investigated group of contaminants released from each of the listed pollution sources for the period 2011-2020 in Bulgaria are the following: sulphur and nitrogen oxides, non-methane volatile organic compounds, methane, carbon and dinitrogen oxide, carbon dioxide and ammonia. A hierarchical organization of the objects from the mentioned sets is built. This studied information from time series stored in xlsx files is structured in a relational database. In this connection, the values of contaminants from a certain pollution source in the relevant file are presented in matrix form. The variation of the number of columns in the formed rectangular matrix depends on the number of the examined years. The data are regrouped to obtain the transposed matrix. The components from each column of this matrix are entered into a selected field of a certain table from the database. The presented approach integrates the processes of searching the indicated data, restructuring and grouping separate datasets, and entering them in the built database. Certain criteria are defined in order to form and extract groups of elements from one or more tables of the database, as well as to establish the relevant dependencies for the studied objects. Analysis of variance and Tukey's range test are used for statistical assessment of the data. The approach can also be applied to examine datasets on air pollutant emissions for other countries. [ABSTRACT FROM AUTHOR]

This paper focuses on the creation of Asset Administration Shells (AASs) for industrial manufacturing components. A decentralized production line with 3D printers is presented. The customer can choose a product in the e-shop and its production is negotiated between individual printers based on predetermined parameters. It introduces the reader to the concepts of Industry 4.0 and explains the structure and methods of AAS development using available software tools. This paper also illustrates decentralized control in practice with the use of a demonstration testbed. The testbed consists of an online e-shop and a group of 3D printing units whose AAS are implemented in the programming language Python. [ABSTRACT FROM AUTHOR]

Cloud computing has revolutionized the way organizations manage their IT infrastructure by providing a flexible, scalable, and cost-effective solution for delivering computing resources as a service over the internet. OpenStack is an open-source cloud computing platform that provides a standardized framework for deploying private and public clouds. A typical OpenStack deployment consists of a set of interdependent components or services that work together to provide a complete cloud computing environment. The paper presents a deployment of an OpenStack private cloud to be used as a testbed for containerized workloads. A centralized architecture pattern is chosen and the Ceph platform is used as a distributed storage system. The proposed deployment is evaluated and confirmed to meet the required performance metrics. [ABSTRACT FROM AUTHOR]

In this paper, the possibilities of the national and European policy for the development of innovations are considered. The aim of the paper is to analyse the opportunities provided by the main strategies and programmes in the new programming period 2021-2027, 2030 of the industrial companies in Bulgaria and their potential for the development of innovation activity. The research has been done by analyzing and synthesizing data and information collected, and information, studies, strategies and work guidelines from national and European strategies and policies. [ABSTRACT FROM AUTHOR]

Scientific research and innovation ensure the achievement of smart growth, high levels of employment and incomes, improving the economic situation of the country. The aim of the paper is to explore the possible sources of funding for innovation in Bulgarian enterprises, the methods for determining the costs of research and experimental design work, the funding programmes for sub-cluster research and innovation projects for the 2020-2027 programming period. The main obstacles and challenges in financing innovation are outlined. The methodological basis of scientific research is a systematic approach, general scientific abstraction, induction, synthesis, content analysis, statistical data analysis, socio-economic modeling, empirical research methods, qualitative and quantitative data collection and processing methods. [ABSTRACT FROM AUTHOR]

With the growing amount of digital data being produced every day, secure and reliable storage solutions have become increasingly important. Data integrity is crucial in the government, business and public sectors. Data loss can mean unrecoverable losses of money, reputation or trust. OpenZFS, a modern file system, offers advanced features for data integrity, protection against data corruption, and flexible storage management. This paper explores the properties of OpenZFS and its application in securely storing data. [ABSTRACT FROM AUTHOR]

Financial markets were the first to react on COVID-19 pandemic and were also very sensitive on following lock-outs, support policies and restrictions. Though equally exposed to the threat and lack of information, different countries reacted to the disease in a different way. In this paper we focus on European financial markets and respective representative indices to analyze their characteristics and study their response to the economic changes that followed the outbreak of the pandemic. We use six European stock market indices (FTSE 100, CAC 40, DAX, IBEX 35, FTSE MIB and STOXX Europe 600) to compare their performance before and after 2020, assess their reaction on COVID-19 and discuss their recovery. Using MLE estimation and BFGS optimization we analyze return distribution and use them as proxy for pandemic impact. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the trends in banking services. The consequences of the severe post-Covid-19 crisis and the isolation have had a strong impact on all areas of business. This has led to a rapid digitization and implementation of smart bank branch technology, aiming at saving financial resources. Transactional models, representing the participants in a mobile payment transaction, as well as the connections, by means of which the communication takes place, are considered. The application of artificial intelligence in the bank activities and in the activities of the new bank branches is analyzed. The trends for future development of both the bank branches and the banking operations are outlined. [ABSTRACT FROM AUTHOR]

Speed estimation problem stands viral for the field of electric drive control theory. This paper presents a study of two angular speed estimation methods of AC motor drives. On the example of an induction motor drive with direct stator field vector control speed feedback and with speed monitors, a comparative analysis is carried out. A comparative analysis of classical model-reference adaptive system and a neural network speed estimator is given. The study analyzes the effectiveness of well-known artificial neural network-based techniques and shows how they can be strengthened using some expert knowledge. Whereas many researchers denote that using black-box concept in electrical drives parameters estimation does not give the best solutions. Better results could be achieved by involving known relations between the estimated parameter and the other known parameters of the drive. Here come the so-called grey-box techniques, where expert knowledge supports the estimation algorithms. [ABSTRACT FROM AUTHOR]

The object of the following paper is to present the process of designing and implementing and verifying a new bioinformatics information system containing a biological database. It is designed for collecting and analyzing nucleotide/protein sequence data for scientific research work and educational purposes. The Needleman-Wunsch global alignment algorithm is implemented and verified by conducting experiments using online bioinformatics tools. It is also used to test the performance of the proposed bioinformatics information system. In addition, several test cases, in which the alignment of biological sequences is used for clinical diagnosis, are considered; detecting patient similarity; gene prediction, etc. The paper includes a brief state-of-the-art on online biological databases and bioinformatics systems and tools. [ABSTRACT FROM AUTHOR]

Based on a performed analysis, an analytical method is proposed in the paper, for determining the accuracy during processing, taking into account the mutual influence of the components of the total inaccuracy. This is of particular importance in the processes of finishing treatment, such as surface plastic deformation (SPD), where technological heredity and the formative technological environment play an important role in forming the quality of the finished part. The matrix approach is applied, describing most fully the mechanism of formation of the constituent inaccuracies, taking into account the phenomenon of "technological heredity". The sequence for determining the transformation coefficients is given, by which the degree of mutual influence of the constituent inaccuracies in the interaction of the workpiece with the technological environment at the level of an operation is shown. [ABSTRACT FROM AUTHOR]

The aim of this paper is to describe the effects of heat input on the microstructure and properties of laser cladded AISI H13 and Capilla 66 tool steel. The laser cladding or laser metal deposition (LMD) process is affected by a number of parameters that could degrade the final surface properties. The H13 tool steel powder is often used for hot work tools repair and also for additive manufacturing. During cladding, the temperature of the part rises, which changes the process conditions. The paper describes how the cladding strategy itself affects the resulting properties, especially in terms of hardness and abrasion resistance. As the heat input increases, there is higher dilution with the cladded part. The accumulation of heat during 3D cladding or AM printing also leads to a loss of properties due to temperature effects. The Capilla 66 powder shows less loss of properties compared to the more commonly used H13 steel. Hardness after cladding of Capilla 66 is about 100HV1 higher and more uniform in heat affected zones. Despite similar chemistry, Capilla 66 shows less tendency to soften both during cladding and during post-processing heat treatment. But, for the same processing parameters, AISI H13 shows higher cladded volume per unit of time approx. about 40%. The experiment proved that by suitable heat treatment, the hardness of the deposit can be homogenized and increased by secondary precipitation, possibly also by residual austenite transformation on martensite. [ABSTRACT FROM AUTHOR]

The present paper is devoted to experimentally registered recordings of ECG signal and heart rate, using a textile-embedded online monitoring tool for recording heart activity. The experiment was conducted by surveying squash athletes during their training period. [ABSTRACT FROM AUTHOR]

The paper considers the problem of observability and controllability gramians computation for one-dimensional and two-dimensional heat equations. The heat equation is a parabolic differential equation representing the process of heat flow. In the one-dimensional case, the heat equation models the physical process of a heat flow in a rod. In the two-dimensional case, this equation shows how the heat flow changes in a plate. The solutions of the heat equations are derived by applying the time-space separation principle and by using the Fourier series approximation. The zero input solution participates in computing the observability gramian of the distributed parameter system. The solution of the nonhomogeneous differential equation under zero initial conditions is used for computing the controllability gramian. Both solutions are based on the state space formulation of the infinite dimensional systems into an abstract differential form. The gramians computation procedure uses the Riesz-spectral framework of trajectory representation. The obtained system gramians are derived in explicit form, which allows their simple form of computation. [ABSTRACT FROM AUTHOR]

The focus of the present theoretical paper is on analysis of longitudinal fracture in a functionally graded load-carrying beam structure with curvilinear axis subjected to impact loading. The structure is hit on its top by a striking object that falls from a relatively low height, i.e. the longitudinal fracture induced by low velocity impact is inquired into. The impact is in the mid-span of the structure. The longitudinal crack problem in a curvilinear structure under impact loading is solved by the method of integral J. Solution is extracted also for static loading of structure. The two solutions are compared. [ABSTRACT FROM AUTHOR]

This paper deals with theoretical analysis of a delaminated multilayered functionally graded rod subjected to centric impact by a falling object. The case of low velocity impact loading (the object that strikes the rod falls from a relatively low height above the rod) is studied. The rod is vertical. The lower end of the rod is fixed, the upper end is free. The falling object hits the rod in the centre of the upper end. Thus, the rod is under centric longitudinal impact. The strain energy release rate is derived for both cases (impact loading and statically applied load). [ABSTRACT FROM AUTHOR]

Pedestrian crossing is important question about road safety. It must be guaranteed at every junction and another places on a street when it requires. Its implementation need to be carried out in such way that it does not lead to negative consequences for traffic flows for which it is required to carry out the necessary in-depth studies of traffic indicators. This paper present the application of a conventional approach to ensuring a safety crossing at a light regulated junction in town of Vratsa with no opportunity provided up to this point. The need to ensure the crossing of pedestrians was assessed and the necessary times ensuring safety were calculated. [ABSTRACT FROM AUTHOR]

For successful implementation of the fused deposition modeling (FDM) process, a combination of large number of well-balanced process parameters is needed. After years of research, the surface quality of FDM-produced parts is still an issue. In this paper, 16 combinations of eight main FDM process parameters are examined to receive a high surface quality. A design of experiments approach is performed to find the proper combinations and to analyze the results. Specially designed test specimens with six differently tilted surfaces were printed using polylactide (PLA) filament. The results indicate that the layer height and the tilt angle of the surface have a major effect on the surface roughness. Specific parameters sets are recommended for each surface angle of the tested part. [ABSTRACT FROM AUTHOR]

Bi-level formalization is applied to define an optimization problem that integrates two important business tasks: inventory management and production with the delivered resources. The inventory task increases costs and they reduce the potential profit of the business entity. On the contrary, the production task directly increases profit, but it has resource limitations provided by the inventory policy. Synchronization of these two tasks can benefit the business entity and increase its profit. The paper provides a formalization of such a problem, allowing maximizing the profit from integrating these two tasks into a common business policy. The upper problem in the bi-level formalization is aimed at minimizing the cost, allocated to resource delivery. The low-level problem aims to maximize production by using available resources. As a result, the objective function of the bi-level problem is aimed at maximizing profit. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present digital twin development of flexible assembly stations (FAS) and discuss it implementation and describe a real application. The FAS-200 of company system proposes training near to the industrial reality, including a real assembly process and digital twin technologies. This system configuration has five phases and cells as follow for: assembly, handling, quality classification, transfer and storage. It is a modular one, flexible equipment and in close to the automation reality. The main goal of this paper was to create a digital twin of two stations: lid classification station and lid rejecting and transferring station. The first item to attend was the creation of the three-dimensional model of the mechanical components, for what AutoSim (SMC) was used. The second-virtual system works like a physical system when it is connected to the PLC program. Finally, there are obtained good results of digital twin implementation with two of the real stations. [ABSTRACT FROM AUTHOR]

Electrical substations are critical components of the electrical grid, responsible for voltage regulation, switching and protection of the electrical system. However, like any other complex system, substations are vulnerable to various problems such as sparks, oil leaks, cracks and other malfunctions, which can lead to equipment damage, power outages and safety risks. In this paper, a 3D model of the outdoor part of a substation is proposed for educational purposes. The model allows students to carry out the behaviour of a professional electrician who performs a routine preventive walk by interacting with the system. During the experimental walk-through in the virtual electrical substation, students can observe various weather conditions, detect potential equipment problems that occur randomly, and report the need to fix them. The problems, which can be found in the electrical substations during the preventive inspections and the actions that must be taken by the electricians in these cases are analysed. Experimental results confirm the utility of realistic, interactive, 3D modelling of real-world objects for educational purposes. [ABSTRACT FROM AUTHOR]

In this paper, an experimental investigation is conducted to examine the electrical conductivity of glass epoxy composites containing graphene and carbon nanofillers. The hand lay-up technique was used to fabricate the GN–glass, MWCN–glass, and GN–MWCN–glass hybrid epoxy composites. The nanofiller weight fraction at 1.5 and 3 wt. % was analysed. The electrical conductivity test was carried out using two-probe methods to evaluate the GN and MWCN nanofiller's contribution to forming conductive networks within the epoxy matrix and glass fibre. The result indicates a higher electrical conductivity value of GN–MWCN–glass hybrid epoxy composites due to hybrid nanofillers incorporation. Field emission scanning electron microscope analyses the nanofiller's dispersion and random distribution in the composites. The good conductivity was related to the better bond formation of the nanofillers with the epoxy matrix. The electrical conductivity results obtained from this study will serve as a basis for investigating the correlation between electrical resistance and strain characteristics in the self-sensing monitoring composite for future research. [ABSTRACT FROM AUTHOR]

A one-dimensional (1-D) seismic site response analysis were conducted using the nonlinear (NL) methods to assess the peak surface acceleration (PSA) and soil amplification. 10 profiles were selected from Peninsular Malaysia site. Three earthquake time history such as Loma Prieta, Acheh and Ranau were scaled to 0.03g, 0.07g and 0.10g and applied to all sites. The results showed that the calculated PSA and soil amplification factor are higher at soil types C compared to soil types D. Moreover, the NL results showed that deamplification did occur in the soft soils of Peninsular Malaysia. The paper contributes to the seismic site-response studies for soil amplification in Peninsular Malaysia. [ABSTRACT FROM AUTHOR]

Maximum Power Point Tracking (MPPT) is a crucial technique for photovoltaic (PV) systems to maximize their energy conversion efficiency. This paper briefly reviews various MPPT techniques and algorithms utilized in solar-powered systems. The benefits and drawbacks of each strategy are explored, and a brief comparison table is offered to make it easier to choose the best MPPT approach for a given application. The paper also discusses the importance of MPPT research in harvesting pure energy from renewable energy sources. The paper also highlights the power output issues faced by solar-powered systems, especially in partial shading conditions, which reduce the power output of the systems. Nonetheless, the maximum power point (MPP) is the only power point needed to obtain maximum PV power. Overall, this paper provides valuable insights into MPPT techniques and algorithms, their strengths, and limitations, and their suitability for different applications. [ABSTRACT FROM AUTHOR]

Geological hazard such as slope failure poses a great threat to human life and properties all around the world. Slope stability analysis is conducted to identify the critical slip surface and the factor of safety of the slope. It may be induced by many factors such as the infiltration of rainwater and surcharge loading including the groundwater movement where all the possible causes may reduce the strength of residual soil that is tremendously influenced by weathering condition. Commonly, the stability analysis is conducted by using the Limit Equilibrium Method (LEM) utilising analysis by using various method of slices. Alongside the innovation of technology and the development of knowledge, the Finite Element Method (FEM) has come to its function as a quick and robust tool for slope analysis. The main objective of this paper is to determine the stability of a slope in Universiti Pertahanan Nasional Malaysia (UPNM) campus based on finite element utilizing strength reduction method (SRM) using Plaxis software. The new slope construction on granitic residual soil in UPNM campus requires a study concerning the stability of slope as high groundwater table in this area had been discovered with spring water that seeps through soil and fractured rock at several locations particular at slope section greater than 45˚. From the result, it is observed that the safety factor for slope angle reduced from 2.254 to 1.188 when the inclination angle increased form 15˚to 45˚ respectively by limiting the height up to 10 m at the uphill section. The results of this study had shown that FEM software such as Plaxis can be practically used to accessed stability of existing slope by utilising strength reduction method approach. In comparison, the slope with greater angle of 45˚ exhibits the least value of safety factor and smaller slip surface compared to that of more gradual slope in this study. This could help us identify the potential failure zone and implement possible remedial measures. [ABSTRACT FROM AUTHOR]

The development of health monitoring systems has generated considerable interest among researchers in WBAN. The WBAN require a MAC protocol that aligns with BAN principles and fulfills specific requirements. However, designing an efficient MAC protocol for WBAN is challenging due to the distinctive attributes of the wireless channel and the need to minimize energy consumption. This paper aims to comprehensively analyze the performance of MAC protocols specifically designed for WBAN. To achieve this, under different scenarios, we evaluate the performance of two widely used MAC protocols, namely IEEE 802.15.4 (ZigBee MAC) and IEEE 802.15.6 (Baseline MAC). We utilize the Castalia-3.2 framework and the OMNet++ simulator to conduct our evaluations. We assess the performance of these MAC protocols in two configurations: GTS ON, which combines CSMA/CA and TDMA, meanwhile GTS OFF, which employs only the CSMA/CA access mechanism. The simulation results demonstrate that the MAC protocol incorporating CSMA/CA and TDMA outperforms the MAC protocol based solely on CSMA/CA. [ABSTRACT FROM AUTHOR]

The utilisation of composite materials in aircraft structures has constantly been in an uptrend in the aerospace industry. However, composites do require protection to preserve their strength and prevent the components from experiencing external reaction such as corrosion. This can be done by applying a layer of sealant on the machined surfaces of the composites. The study focused to achieve the desired base-accelerator proportion required to form the sealant. This paper will discuss the viable parameters expressed in the Hagen-Poiseuille equation, the methodology practised, and the potential factors affecting viscous flows. The latter section of this study proposes the desirable parameters which shall be set as variables for dispensing systems which involve the handling of viscous fluid flows. The experimental data revealed and validated that varying the tube length yields the highest accuracy and consistency, with a minimum error of 0.403% compared to the desired base-to-accelerator ratio, and the lowest standard deviation of only 0.040. [ABSTRACT FROM AUTHOR]

Nonlocal theories are widely used in the mathematical modeling and analysis of solid structures and materials, particularly in micro-nano/structural studies, including fatigue assessment and crack analysis of these structures. Hence, contrasting the outcomes of these theories can significantly help in the selection of a more appropriate and practical model. In this paper, two nonlocal theories, the nonlocal elasticity model, and the stress intensity factor model were employed to analyze an elastic plate with a tip crack. An elastic plate with a tip crack under the impact of axial tension was examined and the results of maximum stress component along the crack line for various crack sizes were compared. Also, the effect of characteristic length in nonlocal models was investigated. Furthermore, ABAQUS CAE software was utilized for finite element modeling by applying the mechanical properties of an elastic steel plate to numerically investigate the elastic plate with a tip crack. The results illustrate the mesh sensitivity of finite element modeling and its compatibility with the stress intensity factor model; however, the numerical study cannot demonstrate the characteristic length effect. [ABSTRACT FROM AUTHOR]

Precast concrete is one of Industrialized Building System (IBS) types that is mainly used in Malaysia. Even though precast shows promising performance in ongoing project but in building maintenance, precast shows otherwise. This is due to the usage of the conventional method (paper-based report/unsystematic data of maintenance which is Computerized Maintenance Management System (CMMS) and by integrating it with BIM technology will help in enhance maintenance. BIM shows its benefits through maintenance by showing its coordination in design and three-dimensional visualization. This paper help into identifying the requirement of integrating CMMS and BIM technology in precast building maintenance. An interview was conducted to gain the objective of the study. Results showed that there are two requirements to support CMMS and BIM integration in maintenance management which is a complete and organize data and a compilation of a standard requirement that stated by the department (e.g., Fire and Rescue Department of Malaysia, Syarikat Air Selangor and JKR). This resulted in the creation of a crucial aspect of the maintenance management system that uses emerging technology to aid engineers at precast building in improving their present maintenance management practices. [ABSTRACT FROM AUTHOR]

Precast concrete is one of the most common forms of Industrialized Building System (IBS) in Malaysia. Although it performs well in ongoing projects, it performs poorly in building upkeep. This is due to the use of the conventional approach of maintenance, Computerized Maintenance Management System (CMMS), which will be enhanced by merging it with BIM technology. BIM demonstrates its value in maintenance by demonstrating design coordination and three-dimensional modelling. This paper help into identifying the factor lacking awareness of CMMS and BIM integration for precast building maintenance. An interview was conducted to gain the objective of the study. Results showed that one out of 6 interviewee is aware of the CMMS and BIM integration for building maintenance. It shows that there is a lacking awareness of the integration of this technology for building maintenance. The factors of this lacking awareness are due to lack of professional interactive, lack of research on BIM implementation and training expenses and the learning curve. [ABSTRACT FROM AUTHOR]

The goal of this study is to outline the outcomes of analysis on the creation of useful math learning resources during the COVID-19 pandemic. The issue is that goods from the creation of math learning resources are required to counteract an acceleration in learning following the COVID-19 epidemic. Many of the results of development research, however, are only kept as study materials and are only preserved in Study Program documents or on Google Drive. The study was conducted utilizing the survey methodology, questionnaire data collection strategies, and development research outcomes papers completed by students of the Mathematics Education Study Program FKIP UPGRI Palembang during the COVID-19 epidemic. strategies for analyzing quantitatively described data. The outcomes of the development research take the form of products for math learning devices, with PBL/PBM, RME, CTL, and mathematics software being the most widely utilized learning models and methods. E-modules, LKPD/LKS, learning media in the form of video, and PPT are the most common product kinds. Algebra, Geometry, Calculus, trigonometry, statistics, and Arithmetic are among the mathematics topics covered throughout the development. The development's validity yields a product quality of 87.19%, while its practicality comes in at 85.48% and its potential impact is at 83.48%. According to the development research's findings, it should be given some thought if mathematics instruction is to be changed following the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

This paper aims to find out the initial information and describe the needs and obstacles in learning physics from the point of view of students. It was found that teaching and learning activities have used Kurikulum Merdeka and there are still shortcomings in the availability of learning resources. This research uses a descriptive method with data analyzed using data reduction. A total of 128 students participated in this survey. The results showed that: (1) renewable energy material is the most difficult topic for students to understand; (2) there are some difficulties felt by students during online physics learning such as difficult-to-understand material, lack of learning resources, explanations are not accompanied by examples of application in daily life, and learning tends to assignments; (3) 84.3% of students argue that the stem approach can help them understand the taught physics material. (3) 58.6% of survey results stated that it is very important in developing stem-based e-learning to improve students' creative thinking skills. (3) Physics learning content that students want includes images, videos, audio, and text. The results of this study indicate that stem-based learning needs to be developed to improve students' creative thinking skills. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop worked example-based learning tools as an effort to improve the representation ability of junior high school students. The subjects of this research were students of class VIII SMP Negeri 1 Talang Kelapa as many as 2 classes. This research is Research and Development (R&D) research. There are 5 stages in this research, namely (1) Analyzing the developed product, (2) Developing the initial product, (3) Expert validation and revision, (4) Small-scale field trial and product revision, and (5) Field trial large scale and final product. Worked example-based learning tools consist of lesson plans and teaching materials, where the lesson plans contain step-by-step activities with a worked example approach and also a textbook containing material, sample questions and exercises. This worked example approach emphasizes giving examples of questions and questions must be made at the same time, one page on the front of the paper, and parallel to each other and not much modification in the problem. This is to reduce the cognitive load of students. With this worked example, even low-ability students can do well on the questions. Based on the results of the study, several research conclusions were obtained, including the lesson plan based on the worked example which was developed valid according to expert appraisal with an average score of 3.40 and for textbooks based on the worked example 3.66 scale of 4. From the limited test, the results obtained that the ability test questions representation is also valid and reliable. The worked example-based learning tools developed was also practical with an average score of 3.92 on a scale of 4. And the average result of the mathematical representations value in the experimental class was better than the control class. This means that worked example-based learning tools are effective in improving students' mathematical representations abilities. In this way, worked example-based learning tools can be said to be valid, practical and effective. [ABSTRACT FROM AUTHOR]

This paper aimed to describe the implications mathematics education in finance. Calculation of interest rates, discounts, profits, taxes, GDP growth requires basic arithmetic skills such as percentages. By imbuing financial literacy in math learning, not only do students know firsthand the use of percent in financial situations, but they are also increasingly knowledgeable about finance. Financial literacy in our study spans three dimensions: content, context, and process. By using the proportion and equation approach as well as two types of construction, namely the bar model and the circle model, we present the learning situation of monthly salary allocation table. Through this situation, students are expected to be able to construct fractional material and financial knowledge on salary and income content. [ABSTRACT FROM AUTHOR]