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This issue of the RECENT journal was edited with the support of: ContentsTechnical Textiles Market Research and Added Value Analysis: A Regio-Global Case Study
RECENT J. (2023), 71:162-180 https://doi.org/10.31926/RECENT.2023.71.162 Abstract High-value-added products such as technical textiles are increasingly in demand in global markets. In the last decade, many countries have transformed their production processes towards producing these products, aiming to become more competitive in the international arena in terms of economy. This study aims to reveal the current situation of the textile industry and its transition to higher value-added technical textiles in Türkiye, particularly in Bursa, as one of the textile hubs. Current global trade volumes of products, import-export data, and Türkiye's position in this sector are analyzed. Additionally, technology and market trends for technical textile products are discussed. The number of global exports in technical textiles increased to approximately 118 billion dollars, increasing by 3.38% compared to the previous year. Türkiye's exports in 2021 were realized as 2,413 billion dollars, a decrease of -12.91% compared to the previous year. Calculating the Grubel-Lloyd Index in Türkiye's technical textile product groups revealed that the intra-industry trade is two-way, except for a few product groups. The average index value for all technical textile products was calculated as 0.7968. Technical textiles are classified into 12 subcategories according to their application areas. It is anticipated that by 2028, the most significant trade items will be in the Mobiltech, Indutech, and Packtech subcategories of technical textiles. Keywords technical textiles, market analysis, high-value-added, Grubel-Lloyd index, Bursa The Influence of the Manufacturing Process on the Average Grain Size Behaviour of the 6063-Aluminum Core Alloy Clad With 4004 Alloy, O Temper
RECENT J. (2023), 71:181-187 https://doi.org/10.31926/RECENT.2023.71.181 Abstract This paper aimed to evaluate the influence of manufacturing process of AA6063 core cladded with AA4004 on average grain size behaviour. Therefore, multiple experimental trials were conducted to investigate the effects of the homogenization soaking time of the AA6063 slabs and the final annealing soaking time on the grain size of the obtained clad coils. A correlation between the average grain size and these variables of the production process was established, indicating that specific material properties can be achieved by manipulating certain process parameters during the manufacturing process of the AA6063 core cladded with AA4004, O temper. Keywords AA6063 core, AA4004 clad, soaking time, average grain size Prediction of the Average Grain Size for AA5754 Plates and Sheets by Using Supervised Machine Learning
RECENT J. (2023), 71:188-193 https://doi.org/10.31926/RECENT.2023.71.188 Abstract The enhancement of aluminium alloys mechanical properties can be achieved through the process of grain refinement. Grain size stands out as the primary indicative factor employed in industry to define grain refinement. This has led to a growing interest in the creation of precise models for predicting grain size. Methods rooted in data-focused informatics are gaining significance in assessing material properties that prove challenging to gauge or calculate through conventional means-often due to constraints related to cost, time, or labour. These methods leverage existing dependable data or have the potential to generate such data, particularly for essential scenarios. In this paper, several models are presented for predicting the average grain size of plate or sheet products made from AA5754, specifically in H111 or H22 tempers and with thicknesses ranging from 1 mm to 100 mm. These models are developed through regression analysis of empirical data, emphasizing the influence of factors like alloy composition, mechanical characteristics, and final product thickness. The findings underscore the efficacy of machine learning in constructing a data-oriented predictive model for grain size in AA5754. Keywords AA5754, average grain size, regression Teaching Technical Students Industrial Process Engineering
RECENT J. (2023), 71:194-201 https://doi.org/10.31926/RECENT.2023.71.194 Abstract Pursuing the current tendencies, this paper aims at presenting a method of teaching process engineering to students, during the entire university period of studies. This method will easily cover the degree programmes and as well as the master studies, building a bridge between academic and industrial fields. Besides technical issues the essential of industrial continuous improvement methodologies are considered. Using simple methodology tools as SMART, Brainstorming, Eisenhower, Ishikawa, PDCA and SWOT students should buy in the industrial analysing approach. Without these kinds of tools, the technical knowledge by itself is incomplete in the industrial environment. A future specialist combining the critical thinking, curiosity and technical knowledge becomes a valuable HC for the company he will perform into. Within this paper I highlighted practical examples of learning process engineering methodology. In order to have an approach process based I underlined the input as the graduate recommended features and the output as the job profile of a specific industrial role. The positive measured impact and feedback after each generation of students assured me that we are on the right learning track. Keywords lean, student, human capital, job Determining the Diffusion Coefficient in Practice of Nitrogen and Carbon for Nitro-Carburizing High Alloy Steel
RECENT J. (2023), 71:202-207 https://doi.org/10.31926/RECENT.2023.71.202 Abstract Through concomitant diffusion of carbon and nitrogen it is aimed the obtaining of superior characteristics of layer and the increasing of efficiency of diffusion process, compared with the simple nitriding. The phenomena of wear, fatigue and corrosion are the main factors that lead to out of use of a tool. All these unwanted phenomena have a common feature: they preponderant occur or in exclusiveness in the superficial layer of the tool. From these considerations appears special significance that is giving researching the physical -chemical processes which occur in superficial layers, as well technologies of obtaining of these layers. Hardness, wear, and fatigue problems are resolved by using in majority of cases of some thermo-chemical and heat treatments, which allow the obtaining of the necessary proprieties of exploitation due to transformations that occur in steel at heating-cooling it. Keywords diffusion process, thermo-chemical and heat treatments, superficial layer, X-ray spectra Modern Society Facing Morality of Large Language Models
RECENT J. (2023), 71:208-220 https://doi.org/10.31926/RECENT.2023.71.208 Abstract Interest in Artificial Intelligence has increased in recent years, as hardware technologies have evolved to the level at which they can support the real-time operation of complex systems such as the Large Language Models (LLM). Modern Artificial Intelligence systems are based on technologies such as Deep Learning, Reinforcement Learning, Machine Learning-Based Attention, Long Short-Term Memory. The present paper identifies the main morality issues that arise with free access to the development of artificial intelligence by the population. These are problems that affect especially educational system, because in the last years pupils and students have used more often these chats to access information or solve problems. Keywords AI, morality, ethics Research on Correlation Analysis of Stainless Steels Experimental Results
RECENT J. (2023), 71:221-227 https://doi.org/10.31926/RECENT.2023.71.221 Abstract The analysis of industrial processes mainly uses fundamental statistical methods, which allow the drawing of conclusions from the observed values on the distribution of the frequency of various parameters, their interaction, as well as the verification of the validity of certain hypotheses. When studying the dependence between the parameters of a process, there should be determined whether the parameters initiating the process are independent of each other or influence each other (depend on each other) thus, to determine the correlation between the parameters and to establish the type of the connection between parameters. In this paper, the Correlation Analysis is used to define and characterize the relationship between the process performance, Y, microhardness [HV100] and variables X1, carbon percentage, C [%], respectively X2, chromium percentage, Cr [%], of the specific chemical composition of six stainless steels, used in industry. Based on the values obtained for the 3 simple correlation coefficients (ryx1=0.98; ryx2=0.85; rx1x2=0.87) and for the multiple correlation coefficient (ry,x1x2 =0.98), after applying the Student and Fischer Criteria, there is accepted the alternative hypothesis (H1), asserting with a probability of 95% the existence of a correlation between the dependent variable Y and independent variables X1 and X2, an thus there can be stated that X1 and X2 are the technological parameters of the studied process, highly influencing it. Keywords correlation analysis, simple and multiple correlation, Pearson correlation coefficient (PCC), microhardness The Performance of Production Systems: Indicators, Influencing Factors, Improvement Solutions
RECENT J. (2023), 71:228-233 https://doi.org/10.31926/RECENT.2023.71.228 Abstract Nowadays, the demanding requirements of the market and the accelerated pace of change are the main threats to the production systems. The survival and success of a production system depends on its ability to produce goods adapted to the requirements, the speed with which it responds to requests, the prices of products, etc. These requirements must be considered permanently, throughout the life of the productive system, materializing in specific performance indicators. Performance indicators are defined for all relevant departments and functions of the company, starting from its strategic objectives. The Key Performance Indicators are the relevant indicators regarding the performance of the system to which they refer. The purpose of this article is to evaluate the efficiency of the use of human resources and equipment for a component assembly line in the automotive industry. The considered performance indicators were labour productivity and OEE. In the presented case study, it was shown how and to what extent the adopted work method and work organization influence the considered KPIs values. Also, the causes of deviations from the planned levels and possible solutions for improvement were highlighted. Keywords performance management, productivity, OEE, RULA analysis CADOProSys Software. Design Conveyors and AGVS
RECENT J. (2023), 71:234-242 https://doi.org/10.31926/RECENT.2023.71.234 Abstract CADOProSys Software (Computer Aided Design and Optimisation of Production Systems) was developed by the authors of this paper for didactic purposes, to facilitate the analysis and selection of certain equipment and processes occurring in production systems. Thus, this software can support the didactic process, by introducing IT into the selection and design stage, without eliminating the needs of knowledge of theory, of the design of material handling logistic equipment. The software is developed on several modules, a general one for defining the production system, one for selecting the production system and one for logistics. Within the logistics component, the application has implemented the robotic structure selection module and the material transport equipment selection module, the one presented in this paper. In the context of Industry 4.0, designing and choosing systems geared exclusively to the current needs of the user are essential processes. The application is structured on the theoretical design of the equipment concerned, but also connects to the technical specifications of existing components on the market. Keywords conveyor, supply chain, selection Assembly Line Balancing
RECENT J. (2023), 71:243-248 https://doi.org/10.31926/RECENT.2023.71.243 Abstract The main objective of balancing an assembly line is to allocate elementary assembly tasks to workstations in order to obtain a uniform load within the line. An assembly line is optimally balanced, when the cycle time is approximately equal to the tact time and the waiting times are minimal. For the optimal balancing of an assembly line, heuristic engineering methods will be used, as well as simulation with the Tecnomatix Plant Simulation software. The method of allocating elementary tasks to workstations is also called the line balancing method. The method uses engineering heuristics and consists of logical solving, through several attempts, and does not guarantee ideal optimization, but finding good, practically acceptable solutions. Keywords simulation, assembly line, line balancing, production productivity, workstation Engineering and Management of the Precision Treatments Spraying System Implementation on Horticultural Crops
RECENT J. (2023), 71:249-255 https://doi.org/10.31926/RECENT.2023.71.249 Abstract The paper presents an analysis of the precision treatments spraying system implementation on horticultural crops. The aim of the paper is to present the typical architecture and the functionality of a spray treatment application system, mounted on a mini-multicopter UAV. The laboratory model of a miniUAV-RW aerial platform adapted for precision transport with high payload rate was presented. Methods of applying the currently existing phytosanitary treatments were identified and innovative solutions were identified for the topic addressed. The proposed precision treatments spraying system improves the quality of spraying, necessary to cover to a greater extent the surfaces and crops. This application is very interesting and actual for a lot of end-users in the actual context of precision agriculture and horticulture constraints. Keywords mini-unmanned aerial vehicles (miniUAV), precision treatments, spraying system, horticulture, crops Evaluation of Graphite Distribution-Part Thickness Ratio in Gray Cast Irons Microstructure
RECENT J. (2023), 71:256-259 https://doi.org/10.31926/RECENT.2023.71.256 Abstract A wedge-shaped sample of gray cast iron was examined under the microscope where the graphite distribution was graded according to SR EN ISO 945-1 standard. The importance of sample thickness on graphite dimensions and distribution, based on different cooling rates observed during the solidification phenomena, is highlighted. For that reason, six areas from the sample were selected for evaluation in terms of microstructure and hardness. When the sample thickness decreased from 7 mm to a minimum of 1.5 mm, a range of hardness average values from 73HRB to 90HRB was recorded. An average length of graphite separations for each area was calculated. It is observed that in this particular sample, the lamellar aspect of graphite was average measured within 7.8 μm to 118.8 μm. Evidence of sliding planes at the graphite boundaries near the indentation area are presented. Despite of inconvenient as low shock resistance limited tensile strength and reduced elasticity; gray cast iron is widely used across diverse industries. Keywords gray cast iron, graphite dimension, hardness Ways of Preventing Water Losses in Real Water Installations
RECENT J. (2023), 71:260-263 https://doi.org/10.31926/RECENT.2023.71.260 Abstract The paper intends to present different ways in which one can prevent losses of water volume in real water installations. The study is performed on real data obtained by recording the water consumption in each apartment from a block of flats, during several months, and also, by considering the total volume of water indicated by the branch water meter, the one indicating the water consumption for the entire block of flats. The number of persons living in each apartment is considered. The paper contains a study on the ways in which errors in metering the consumed water volume are produced, due to the sensitivity of the water meters mounted in the apartments from the block of flats considered. Data analysis was performed on data collected from the water meters considered, in order to establish the water loss volume and to obtain instruments which can help in identifying any water leakage in any apartment, such as to be able to sense any modification drift from the medium consumption such as to analyse the water loss estimated for a month for each type of water meter considered. In this way, it is possible to estimate the water loss volume for a certain period of time for the block of flats considered and, by that, to find ways to prevent losses in the potable water supply system. Keywords water flow, water meter, water loss volume Application of the Experiential Learning Theory in Engineering Education
RECENT J. (2023), 71:264-268 https://doi.org/10.31926/RECENT.2023.71.264 Abstract The paper presents some aspects on applying the experiential learning theory in engineering education, focusing on the issues related to teaching graphical subjects. The experiential learning theory describes the process of learning from experience and presents learning as being cyclical, with four stages - experience, reflection, abstract conceptualization and experimentation, each stage being related to a certain learning style. As an important fact, the paper presents the organization of laboratory applications for graphical subjects as descriptive geometry and technical drawing, the case study considered in the paper being related to projecting prismatic parts. The paper outlines features that may help students increase their creation capacity and may help them to develop appropriate learning styles and also, would help to improve students learning, by gaining experience continuously and transforming it into knowledge. Keywords engineering education, experiential learning, cycle of learning Silver Nanoparticles Synthesized by Orange Peel Extract
RECENT J. (2023), 71:269-273 https://doi.org/10.31926/RECENT.2023.71.269 Abstract The current work is presenting the biosynthesis of silver nanoparticles, using AgNO3 as a precursor and orange peel extract as reducer and stabilizer agent. The research structure is based on the synthesis process, from extract preparation, precursor, to final colloidal solutions. The samples were prepared in a ratio of 9:1, precursor to plant extract. The first signs of successful synthesis appeared in about 30 minutes, when the formation of nanoparticles was assigned to a change in colour, from pale yellow to brown. After the synthesis steps, the obtained samples were characterized by UV-Vis spectrophotometry. This analysis has indicated an absorbance peak with highest intensity around 420 nm wavelength. This is matching with surface plasmon resonance of silver nanoparticles, being the first step in proving that silver nanoparticles were formed in the colloidal solution. The removal of toxic elements from the synthesis stages opens new opportunities for the use of particles, there these are intended to be used in medicine and water treatment, afterwards testing antimicrobial and photocatalysis potential. Moreover, this method of obtaining nano-scale particles is an efficient and economical one. Keywords silver nanoparticles, orange peel extract, green synthesis
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