rss_2.0Materials Sciences FeedSciendo RSS Feed for Materials Sciences Sciences Feed of automotive sand casting with different wall thickness from progressive secondary alloy<abstract> <title style='display:none'>Abstract</title> <p>This paperwork is focused on the quality of AlSi6Cu4 casting with different wall thicknesses cast into the metal mold. Investigated are structural changes (the morphology, size, and distribution of structural components). The quantitative analysis is used to numerically evaluate the size and area fraction of structural parameters (α-phase, eutectic Si, intermetallic phases) between delivered experimental material and cast with different wall thicknesses. Additionally, the Brinell hardness is performed to obtain the mechanical property benefits of the thin-walled alloys. This research leads to the conclusion, that the AlSi6Cu4 alloy from metal mold has finer structural components, especially in small wall thicknesses, and thus has better mechanical properties (Brinell hardness). These secondary Al-castings have a high potential for use in the automotive industry, due to the thin thicknesses and thus lightweight of the construction.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Contribution of the quality costs to sustainable development<abstract> <title style='display:none'>Abstract</title> <p>This paper presents a framework of contemporary quality costs concept contributing to a more sustainable society regarding an integrated view of quality costs in all phases of the product life cycle (engineering, production, use, and end-of-life) by all stakeholders in the supply chain. The development of this framework is viewed through the complementarity of the sustainability dimensions and the circular economy concept understood as a waste management concept, which represents a solid basis for the development of a novel approach to understanding quality costs which, in turn, reflects the sustainable quality concept. By providing sustainable criteria (economic, environmental, and social) as an integral part of the quality costs concept, this framework will improve the sustainability performance in the early phases of product design, increase the added value of the products and the duration of the added value, and strengthen the responsibility of all stakeholders beyond the limits of their organizational processes. This will inevitably lead to changes to the quality cost structure, dominated by new quality costs elements which reflect sustainability. This research demonstrates the findings that should support the setting the theoretic assumptions for the development of a sustainable quality cost generic model.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00The Effect of Formal and Informal Regulations on Industrial Effluents and Firm Compliance Behavior in Malaysia<abstract> <title style='display:none'>Abstract</title> <p>The rapid development of the manufacturing sector has been causing industrial effluents pollution. The practice of environmental regulation in the emerging economy focused on the externalities impact of industrialization. In conjunction with the issue, this study examines the effect of formal and informal regulation on the industrial effluent act and the firm compliance behavior in Malaysia. This quantitative study uses a survey questionnaire (structured) and involved 42 factories of three industries, namely food and beverages, textiles, and paper in Penang, Kedah, and Perlis. The data were analyzed using non-parametric tests: The Chi-Square, Mann-Whitney, and Spearman’s Rho. This study uses the firm behavior theory as the framework, and our non-parametric analyses showed that the traditional enforcement and fined probability could significantly affect compliance levels. We also find the market, consumer, competitor, and investor pressure positively influence firm compliance. The empirical results suggest effective enforcement of environmental regulation and the role of non-regulation must be empowered as a support mechanism for pollution control.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Forecasting municipal waste accumulation rate and personal consumption expenditures using vector autoregressive (VAR) model<abstract> <title style='display:none'>Abstract</title> <p>Accurate forecasting of municipal solid waste (MSW) generation is important for the planning, operation and optimization of municipal waste management system. However, it’s not easy task due to dynamic changes in waste volume, its composition or unpredictable factors. Initially, mainly conventional and descriptive statistical models of waste generation forecasting with demographic and socioeconomic factors were used. Methods based on machine learning or artificial intelligence have been widely used in municipal waste projection for several years. This study investigates the trend of municipal waste accumulation rate and its relation to personal consumption expenditures based on the yearly data achieved from Local Data Bank (LDB) driven by Polish Statistical Office. The effect of personal consumption expenditures on the municipal waste accumulation rate was analysed by using the vector autoregressive model (VAR). The results showed that such method can be successfully used for this purpose with an approximate level of 2.3% Root Mean Square Error (RMSE).</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Surface Roughness Reduction in A Fused Filament Fabrication (FFF) Process using Central Composite Design Method<abstract> <title style='display:none'>Abstract</title> <p>The objective of this study is to optimize the fabrication factors of a consumer-grade fused filament fabrication (FFF) system. The input factors were nozzle temperature, bed temperature, printing speed, and layer thickness. The optimization aims to minimize average surface roughness (Ra) indicating the surface quality of benchmarks. In this study, Ra was measured at two positions, the bottom and top surface of benchmarks. For the fabrication, the material used was the Polylactic acid (PLA) filament. A response surface method (RSM), central composite design (CCD), was utilized to carry out the optimization. The analysis of variance (ANOVA) was calculated to explore the significant factors, interactions, quadratic effect, and lack of fit, while the regression analysis was performed to determine the prediction equation of Ra. The model adequacy checking was conducted to check whether the residual assumption still held. The total number of thirty benchmarks was fabricated and measured using a surface roughness tester. For the bottom surface, the analysis results indicated that there was the main effect from only one factor, printing speed. However, for the top surface, the ANOVA signified an interaction between the printing speed and layer thickness. The optimal setting of these factors was also recommended, while the empirical models of Ra at both surface positions were also presented. Finally, an extra benchmark was fabricated to validate the empirical model.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Project of Micro-hydroelectric Power Generation System – Case study<abstract> <title style='display:none'>Abstract</title> <p>The article describes a student project of installing a micropower generation system utilizing energy from the water drained from underground coalmines. The paper contains a description of the site which is a manmade phenomenon from the anthracite mining era. The project described in the article was completed as part of the project-based learning curriculum. Students had the opportunity to work on a team and apply theoretical knowledge learned in individual courses as part of the engineering curriculum. The article also focuses on the calculation of the potential power capacity to a proposed hydropower generation system. The proposed micro-hydro system is harvesting the potential and kinetic energy of the water discharged from the water-draining tunnel. A commercially available micro-hydro turbine combined with an electric power generator was adapted for this purpose. The article also includes an analysis of the profitability of the project and the time of return on investment. The calculations are based on the current price of electricity (2021), depreciation schedule and present tax incentives (2021) to generate electricity from renewable sources. The article also includes some lessons learned from the project as well as the recommendations for future projects.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Formation of coatings with technologies using concentrated energy stream<abstract> <title style='display:none'>Abstract</title> <p>A number of modern surface processing methods use an energy flux. The examples include electro-spark deposition (ESD) and laser beam processing (LBP). The work concerns the study of Cu-Mo coatings deposited on C45 carbon steel, which were then eroded with a laser beam. The analysis included the analysis of the microstructure, measurements of macrogeometry and microhardness, corrosion resistance tests of selected areas after laser treatment. The coatings were applied with ELFA-541 and subjected to Nd:YAG laser treatment with variable laser parameters. The problem presented in the work can be used to extend the knowledge of the areas of application of ESD coatings, especially in sliding friction pairs.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Modeling and optimization of friction stir stitching of AISI 201 stainless steel via Box-Behnken design methodology<abstract> <title style='display:none'>Abstract</title> <p>The paper investigates the modelling and optimization of the notch-repaired/friction stir stitched AISI 201 stainless steel welds via the use of a non-consumable tool-based repair process. The repair process employs a sequential hopping-stitching approach. This approach involves the application of two intercepted and completely overlapped plunging actions of a probe-less titanium carbide tool to create an effective refilling and repair of the notched zone. Box-Behnken design (BBD) was employed for the experimental planning, modelling, and optimization of the notch-repair process. Tool rotational speed, penetration depth and dwell time of the tool were the studied process parameters while tensile strength was the response variable. A quadratic model was identified as the best model for the notch-repaired welds based on the combination of a low sequential P-value of 0.008216, a high lack of fit P-value of 0.931366, and a close to unity adjusted and predicted R-square values. The process parameter and their interaction effects on the tensile strength of the repaired notch were identified via the ANOVA analysis. Plunge depth (main effect) and interaction effect of tool rotational speed and dwell time had significant influences on the notch-repair process and the resultant tensile strength of the AISI 201 stainless steel. The visual representations of these effects were shown through the 2D elliptical contour and 3D response surface plots. The optimized process parameters were identified as 1215.9795 rpm, 0.40262212 mm, and 5.98706376 s while the resultant notch-repaired joint yielded a tensile strength of 886 MPa, which is close to the predicted value.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Numerical simulation of the processes of burning lignite in a vortex furnace with swirling countercurrent flows<abstract> <title style='display:none'>Abstract</title> <p>This work presents the results of a numerical study of the working processes of burning lignite in a vortex furnace with swirling countercurrent flows. The results of computer simulation of the processes of burning lignite with a moisture content of 30%, an ash content of 20% and 35% and a higher calorific value of Qрв = 13.9 MJ/kg and 9.7 MJ/kg, respectively are given. The fields of temperature distribution, gas velocity and particle trajectory in the volume and at the outlet of the furnace are determined. The values of the swirling flow velocity near the exit from the furnace reach 150-170 m/s. Mechanical underburning is 3.7% and 9.4% depending on the ash content. The results of a numerical study have showed that the diameter of lignite particles affects their combustion process: coke particles with an initial diameter from 25 microns to 250 microns burn out by 96%. The furnace provides a complete combustion of pulverized coal particles - 99.8% and of volatiles - 100% at volumetric heat stress in the 2500 kW/m<sup>3</sup> furnace. The afterburning of fuel particles containing carbon is ensured by their circulation</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Influence of the heat insulation layer on the thermally stressed condition of the facade wall<abstract> <title style='display:none'>Abstract</title> <p>The temperature-stress state of the concrete facade wall with a window opening, which is the external enclosing structure of the room with a steel heating device, was investigated by the method of numerical modeling. Estimated studies were performed for winter period when the heating system of the building is functioning. According to the results of solving the system of equations of thermal stress and equation of thermal conductivity, the temperature distribution over the wall volume and distribution of normal and tangential stresses were determined. Areas of the wall where these stresses are maximum were identified. The research was performed for cases of both, absence and presence of a heat-insulating layer on the outer surface of the facade wall. From comparison of the results obtained for these two options, it follows that the external thermal insulation coating not only helps to reduce dissipative heat loss through the facade wall, but also reduces the absolute values of stresses in the concrete wall arising resulting from temperature deformations. In some cases, the sign of stresses changes from stretching (wall without external insulation) to compressive (wall with insulation).</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Revitalization of Mining Dumps. Assessment of Possibilities<abstract> <title style='display:none'>Abstract</title> <p>The revitalization of mining dumps in the Silesian agglomeration is a very difficult and complex problem. It has a substantial impact on the concepts of sustainable urban development. Other than the key areas including people, the environment and the economy, revitalization also refers to spatial management, and thus to a significant improvement in the functioning conditions of the local cities’ communities. The article describes an algorithm assessing the possibilities of revitalizing a mining dump by one of the Polska Grupa Górnicza’s mines. With legal status and location taken into account, several potential scenarios had been proposed, out of which one was chosen based on the adopted criteria. The chosen scenario had been subjected to further assessment using analyses such as SWOT/TOWS, FMEA, and QFD. The analyses had been carried out in order to acquire more effective and meaningful assessments, having taken social and economic aspects into consideration. In effect of the carried out analysis a recreational scenario was proposed. The adopted solution shows that the mine can continue its work in accordance with the principle of sustainable development as well as apply the concept of corporate social responsibility.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Dimensions and Factors that Determine Integration of Small-Scale Sources in the Structures of Virtual Power Plants<abstract> <title style='display:none'>Abstract</title> <p>In the paper the author has attempted to achieve two convergent objectives: cognitive and empirical ones. The cognitive goal constituted an analysis of the definitions of virtual organi-sations and their adaptation while defining Virtual Power Plants (VPPs). When discussing the discourse in the area of virtual organisations, the author has attempted to justify the fact that the terminology pertaining to virtual organisations should constitute the foundations for defining Virtual Power Plants. With such an assumption, a vital importance has been assigned to co-sharing of “soft” resources – key competencies, and also organisational (managerial) integration. In the context of the adopted definitions, the distributed structure of virtual power plant has been em-bedded into four layers of Smart Grid: Customer Technology, Operational Technology, Smart Metering, Energy Management System. A measurable value of the conducted discourse has been aggregation of management functions of VPP, carried out in the four-layer structure of Smart Grid. In turn, the empirical objective was to determine and distinguish, based on the conducted expert research, the factors that determine the development of small-scale energy sector, including re-newable energy sources and prosumer installations – simultaneously determining the inclination of distributed electricity producers to mutual integration in the structures of virtual power plants. Assuming, in accordance with the definitions and discourse included in the first part of the paper, that the determined factors, among others, creating virtual power plants are not only of techno-logical nature, the author has developed four portfolios of these factors. They include the following ones: technological, economic (including micro- and macro-economic), environmental, and social. The experts participating in the research could select 5 factors from each of the developed portfolio which in their opinion determined the inclination of distributed electricity producers to integrate their sources in the structures of virtual power plants. A measurable value of the empirical part has been aggregating the determinants generated and distinguished in the research process.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Physico-mechanical properties, structure, and phase composition of (BeO + TiO)-ceramics containing TiO nanoparticles (0.1–2.0 wt.%)<abstract> <title style='display:none'>Abstract</title> <p>This research studies the effects of addition of micro- and nanoparticles of TiO<sub>2</sub> and variations in the firing temperature on the physico-mechanical properties of oxide-beryllium ceramics, shows the evolution of the microstructure of such ceramics during sintering, and presents the data of X-ray phase analysis. It was shown that the addition of TiO<sub>2</sub> nanoparticles leads to a higher density of the ceramic material after sintering due to the interpenetration of TiO<sub>2</sub> and BeO phases, which is caused by an increase in the diffusion mobility of atoms that can in turn be attributed to an increase in the imperfection of the structure and the fraction of grain boundaries. It was found that the presence of nanoparticles contributes to an increase in the apparent density of the material, as well as a decrease in its total and closed porosity; and an increase in the sintering temperature contributes to the transformation of the crystalline structure of TiO<sub>2</sub> into a more conductive Ti<sub>3</sub>O<sub>5</sub>with an orthorhombic structure. The presence of nanoparticles also promotes self-healing of micropores, which can be explained by the blocking of a certain fraction of the interfaces between BeO particles by nanoparticles and the creation of a diffusion barrier.</p> </abstract>ARTICLE2022-05-16T00:00:00.000+00:00The preparation of CNT/PMMA composite film on SiO substrates<abstract> <title style='display:none'>Abstract</title> <p>Microelectromechanical system (MEMS) has been highly valued since the size of the MEMS structure is miniaturized, the spacing between the components is in the nanometer range, and the behaviors of friction and adhesion greatly affect the reliability of MEMS. An atomic force microscope (AFM) was used to observe the surface morphology of carbon nanotube (CNT)/polymethyl methacrylate (PMMA) film, and X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical state of typical elements on the surface of the film. The friction and wear properties of composite nano-films under macroscopic conditions were systematically studied. The research results show that the composite nano-film has excellent anti-friction and anti-wear properties.</p> </abstract>ARTICLE2022-05-16T00:00:00.000+00:00Decomposition mechanisms of continuously cooled bainitic rail in the critical heat-affected zone of a flash-butt welded joints<abstract> <title style='display:none'>Abstract</title> <p>The joining process of bainitic rails is significant in terms of their industrialization in high-speed and heavy-loaded railways. This paper demonstrates the microstructure changes in the critical zone of the welded joint, which is responsible for the greatest deterioration in mechanical properties. Extensive progress in the decomposition of the retained austenite and bainitic ferrite occurs in the low-temperature heat-affected zone (LTHAZ) of the flash-butt welded joint of low-carbon bainitic rail. The decomposition products of the retained austenite were mainly a mixture of cementite and ferrite. The cementite was mainly precipitated at the boundary of the bainitic ferrite laths, which indicates lower thermal stability of the filmy austenite. Moreover, it was found that a part of the refined blocky retained austenite was decomposed into the ferrite and nanometric cementite, while another remained in the structure. The decomposition mechanisms are rather heterogeneous with varying degrees of decomposition. A relatively high proportion of dislocations and stress fields prove the occurrence of residual stresses formed during the welding process.</p> </abstract>ARTICLE2022-05-10T00:00:00.000+00:00The Analysis of the New Farm Tractors Market in Poland in 2010-2020 in the Context of Income Generated by Farmers’ Households<abstract> <title style='display:none'>Abstract</title> <p>The objective of the paper is to analyse changes in the new farm tractor market in Poland and the annual income of farmers’ households generated in the same period. The studies covered the period from 2010 to 2020. The new farm tractors market was analysed with reference to the number of sold tractors, which was measured by the number of registrations. The paper considers quarterly seasonality of sale along with demand for selected producers and engine-power categories of new farm tractors sold in Poland. By “new tractors” the authors mean those registered for the first time in Poland and manufactured in the same or the preceding year. In 2010-2020, there were over 148,000 new farm tractors registered in Poland. The highest number of tractors sold was recorded in 2012, the lowest in 2016. Tractors from Western Europe, USA, and Japan predominate on the Polish market. Among new vehicles, the highest number registered in the investigated period constituted New Holland (23,780) tractors, followed by John Deere (19,453), Zetor (16,398), Deutz-Fahr (10,508), and Kubota (7,674). The total share of these producers in 2010-2020 amounted to approx. 58%. With regard to the engine-power categories in the analysed period, tractors with power of 37-73 kW and 74-132 kW (33.85%) constituted the largest proportion (49.07%). An increased interest in tractors with power below 36 kW was also observed from 2016 to 2020. Such vehicles accounted for 10% of all registrations. The general trend related to the volume of average annual income is not consistent with the trend of purchasing new farm tractors, while the highest number of registrations was recorded during the period in which inflation rates reached their highest values.</p> </abstract>ARTICLE2022-05-06T00:00:00.000+00:00Medical Devices Management System Based on Blockchain Technology<abstract> <title style='display:none'>Abstract</title> <p>The recent use of digital Distributed Ledger Technology (DLT) in the healthcare domain can surpass the existing limitations in the centralized IT systems, such as the lack of security, access control or immutability of the electronic health information. If we discuss about clinical information, this innovative informatics advance gives back the control to the data owner. In decentralized environments, smart contracts allow trustable agreements grounded by irreversible transactions, which permit transparency and traceability. Moreover, smart contracts are the living heart of the decentralized applications that run on DTL. In this work, our attention is focused on medical equipments that helps health staff to diagnose and treat patients keeping much of their clinical data taken in dynamics. Hence, we propose a smart contract-based decentralized application framework for the management of devices, targeting also medical services, meant to facilitate the interaction of the involved entities. Our testing environment is the Ethereum platform, extensively used recently in the healthcare domain, being itself a smart operating system that allows decentralized applications to run on it.</p> </abstract>ARTICLE2022-04-30T00:00:00.000+00:00Walnut (Juglans Regia): A Review of Phytosanitary Properties and Theirs Mathematical Modeling<abstract> <title style='display:none'>Abstract</title> <p>Walnut (Juglans regia L.) is the most widespread walnut in the world. All parts of the plant are important: bark, leaves, dried and green peel of the fruit, septum, core. The benefits of walnuts are due to the presence of phytochemicals such as flavonoids, carotenoids, alkaloids, polyphenols, etc. In addition to the many benefits that walnut has on our health (antibacterial, antioxidant), it also has important phytosanitary and insecticidal properties. Walnuts can be used because of their plant-friendly properties in the form of biopesticides that are safe and can be a viable, inexpensive and cleaner alternative to synthetic products that can be harmful to the environment. This review paper seeks to bring to the fore the available literature on Juglans regia directed on the properties, antifungals and insecticides with action on plants and antibacterials with action on the human body, as well as mathematical models regarding the multiplication of microorganisms.</p> </abstract>ARTICLE2022-04-30T00:00:00.000+00:00General Considerations Related to the Membrane Material Locking Models ‒ A Short Rewiew<abstract> <title style='display:none'>Abstract</title> <p>The problem of clogging membrane pores has become an area of interest for the vast majority of researchers in the field, because according to the literature, membrane materials are very sensitive when it comes to clogging and blocking pores.</p> <p>Therefore, this paper briefly describes the problems that occur during the process of obstruction the pores of the membrane. Models and characteristics of pore blocking mechanisms have also been developed.</p> <p>It is essential to mention that the principal purpose of the paper, which which consisted to review the simulations and classical models that were optimized, used in the analysis processes of clogging of membrane materials, was successfully fulfilled.</p> <p>According to those mentioned, the combined mathematical models of pore blocking (methods combined with three blocking mechanisms using Hagen-Poiseuille’s law or standard 0-order blocking) have proven to be very effective in describing membrane clogging problems.</p> </abstract>ARTICLE2022-04-30T00:00:00.000+00:00A Review of Metallic Materials Corrosion<abstract> <title style='display:none'>Abstract</title> <p>The present manuscript presents a theoretical study for the corrosion process. Corrosion processes are primed and stimulated in 60% of cases by chemical and biological elements. One of the most used biological elements are: bacteria, actinomycetes, microscopic fungi, algae. Corrosion of a solid body results from the transformation of structural bonds in that body. Less than certain influences (water, oxygen, light, etc.) the atom - which is practically neutral - can lose or gain electrons and it is ionized.</p> <p>Brake pads are affected of corrosion process. The conceptions and mathematical symbols serve as the models building blocks. Authors like, Boz M, and other authors demonstrate in their researches that starting with the concept of number, where every mathematical object is a mathematical model.</p> <p>In practice it is not possible to reproduce some experimental, theoretical conditions related to corrosion processes. These processes are therefore, to some extent, different in terms of the applicability of theoretical laws. From a thermodynamic point of view, metals are not stable and due to corrosion, metals tend to return to the stable form of oxides with the help of oxygen and moisture in the air. For this each metal requires certain ionization energy.</p> <p>When establishing the mathematical model, those characteristics of the modeling object are highlighted, which, on the one hand, are informative, and on the other hand, they admit the mathematical form review.</p> </abstract>ARTICLE2022-04-30T00:00:00.000+00:00en-us-1