rss_2.0Materials Sciences FeedSciendo RSS Feed for Materials Sciences Sciences Feed effect of changing graphitization temperature toward bio-graphite from Palm Kernel Shell<abstract> <title style='display:none'>Abstract</title> <p>This paper focuses on the relationship between heat treatment temperature toward structural transformation from amorphous carbon to highly graphitic carbon material during a production stage.The following report discusses a simple strategy to convert the palm kernel shell (PKS) into highly crystalline, high quality graphite via simple two-step process. The production involves impregnation of catalyst followed by thermal treatment. Both XRD and Raman spectroscopy allowed the observation of microstructural change of the prepared sample at temperature ranging from 1000°C to 1400°C using Ferum catalyst. From XRD pattern it can be observed that as graphitization temperature increased, the degree of graphitization also increased. Overall sample prepared at higher temperature 1400°C shows a higher degree of graphitization. PKS sample graphitized at 1400°C with the aid of Ferum catalyst shows a sharp intensified peak at 2θ = 26.5° reflecting formation of highly crystalline graphite structure. Raman spectrum also suggests similar results to XRD in which PKS-1400 shows the presence of large amount of graphitic structure as the value of (Id/Ig) ratio is lower than in other samples. HRTEM analysis visibly shows define lattice fringe, which further confirms the structural transformation from amorphous to highly ordered graphitic carbon structure. Overall, good quality graphitic carbon structure from Palm Kernel shell was succesfully synthesised via utilization of PKS, Ferum catalsyt and heat treatment method.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Investigation of corrosion rate of X55CrMo14 stainless steel at 65% nitrate acid at 348 K<abstract> <title style='display:none'>Abstract</title> <p>A number of factors determine the mechanical, but also physical and chemical properties. One of the most important are the steel microstructure and its working conditions. A few corrosion processes in crevices and awkward corners can be avoided at the design stage (low roughness parameters, round-section and other). But still the construction material is exposed to corrosion. These steels often come into contact with an aggressive environment based on nitric acid. Stainless steel is more and more often used in many sectors of industry.</p> <p>The purpose of this article is to investigate corrosion resistance in different time (48, 96, 144, 192, 240, 288, 336, 384 and 432 hours) using weight loss and profile roughness parameters of martensitic steel in grade X55CrMo14 in nitric acid 65% pure-basic at temperature 348 K. Corrosion tests show that the tested steel in nitric acid as a corrosive environments is characterized through continuous corrosion process whose measure may be surface roughness.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Barriers to the implementation of innovations in information systems in SMEs<abstract> <title style='display:none'>Abstract</title> <p>Information management and information flow is an important element in the strategy of developing and running a company. The need to supervise information makes it necessary to implement numerous innovations that improve the method of information management correlated with the proper reception, selection and analysis - in both external and internal information flow. This paper presents the results of research that allowed for the assessment of barriers that arise during the implementation of innovative solutions in small and medium-sized enterprises (service MSEs). On the basis of the conducted research, it was found that the mental barrier is not always crucial from the point of view of modern technologies implementation. And the determination to implement information management innovations may be forced by the necessity of the document exchange acceleration. The success of innovative solutions e.g. in the financial services industry (in SMEs) is closely related to the technological capabilities of the enterprise - the technological barrier is crucial in this type of enterprises. Especially, taking into account the assumption that employees are highly motivated to implement new products.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Agri-Food 4.0 and Innovations: Revamping the Supply Chain Operations<abstract> <title style='display:none'>Abstract</title> <p>The agri-food sector contributes significantly to economic and social advancements globally despite numerous challenges such as food safety and security, demand and supply gaps, product quality, traceability, etc. Digital technologies offer effective and sustainable ways to these challenges through reduced human interference and improved data-accuracy. Innovations led by digital transformations in the agri-food supply chains (AFSCs) are the main aim of ‘Agri-Food 4.0’. This brings significant transformations in the agri-food sector by reducing food wastage, real-time product monitoring, reducing scalability issues, etc. This paper presents a systematic review of the innovations in the agri-food for digital technologies such as internet-of-things, artificial intelligence, big data, RFID, robotics, block-chain technology, etc. The employment of these technologies from the ‘farm to fork’ along AFSC emphasizes a review of 159 articles solicited from different sources. This paper also highlights digitization in developing smart, sensible, and sustainable agri-food supply chain systems.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Analysing the machines working time utilization for improvement purposes<abstract> <title style='display:none'>Abstract</title> <p>The article is a case study of the use of snapshot observation to analyse the factors causing time losses at selected laser burner stations, and to propose changes that will increase the effective utilization of working time. The purpose of this paper is to determine the best and worst utilization of working time at the examined workplaces, analyse the amount of time lost and identify the causes of losses, and propose solutions that will improve the utilization of working time. According to the snapshot observation, procedure 2 main - work and non-work - time fractions and 10 detailed time fractions in the working day were distinguished, and their percentage share for the analysed workstations was calculated. Analyses of the working day time utilization depending on the type of machines, days of observation, single shifts were done and selected results were averaged. The paper indicates that organizational and technical aspects, as well as the employees’ faults, were the main reasons for time losses. Research has shown that the generally examined group of workstations was characterized by a high utilization level of working time. An unfavourable phenomenon was the ratio of the main time to the auxiliary time, the high share of the maintenance time fraction of the workstations, and incorrect organization of the interoperation transport, low workers motivation, rush, and routine. It was found that further improvement of work efficiency and reduce time losses requires paying attention to the optimization of employees’ working conditions, training, motivation systems, and implementation of lean concept tools and MES/CMMS solutions into production.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Economy and energy analysis in the operation of renewable energy installations – a case study<abstract> <title style='display:none'>Abstract</title> <p>In the paper an economic, ecological and energy analysis of a home photovoltaic on grid installation was presented. The increase in ecological awareness of the Polish society contributes to the continuous growth of interest in green energy. However, many people haven’t been aware of the ecological, economic and energy benefits of photovoltaic installations yet, so the following analysis is made. The analysis concerns a photovoltaic installation with a capacity of 3.96 kWp located in Ościęciny near Włocławek. The photovoltaic installation consists of 11 monocrystalline panels with a power of 360 Wp, a 4 KTLM Sofar Solar inverter and other necessary components. The first part presents basic issues related to photovoltaic installations. Parameters related to the proper functioning of the photo-voltaic installation were replaced. The analysis of the literature will help to understand the essence of the proper functioning of the photovoltaic installation. In the practical part, an analysis of a selected home photovoltaic installation was carried out. Based on the available data, it has been calculated that the installation will have a payback period of over 9 years. The photovoltaic installation will produce approximately 3 582.61 kWh of electricity and will contribute to the reduction of 70 tons of carbon dioxide during the entire operation.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00ISO 9004 - A stimulating quality management standard for the creative leaders of contemporary sustainable organizations<abstract> <title style='display:none'>Abstract</title> <p>International management standards can provide organizations with challenging opportunities only if they understand the intended aims and features of those standards and apply them creatively and integrated into their business management. For that to happen, the business leaders of the organizations play the key role. For this subject, this discursive article focuses on the ISO 9004 quality management (QM) standard, which is one of the international management standards, which can be applied to all kinds of organizations. In addition to the opportunities, this article discusses difficulties and pitfalls associated with the ISO 9004 standard, and their possible solutions in practical implementations.</p> <p>The authors highlight aspects of how ISO 9004 can be considered as the most challenging standard in the ISO 9000 series of the QM standards. However, many organizations, which have not acknowledged the differences and relationship of the ISO 9004 and ISO 9001 standards, often apply the ISO 9000 standards in inadequate ways and hence have not the ability to exploit the potential opportunities of the standards. Especially, ISO 9004 considers QM from the entire business point of view and aims at the quality of the whole organization. ISO 9004 standard can provide QM guidance to achieve sustained success even in complex, demanding and ever-changing contemporary business environments, including the challenges of the 4th industrial revolution.</p> <p>This article gives ideas and creative theoretical and practical views for the ISO 9004 implementations. The aim is to emphasize that, according to ISO 9004, the organization’s identity and its differentiating competitive advantages are the bases for the quality of the organization and its sustained success. In this context, each organization has its own and always existing QM realization, which cannot be separated from business management and which can be continually improved according to the organization’s business development strategies and practices. In this respect, the ISO 9004 can be seen as flexible and challenging. Based on the authors’ experience, QM targets can be achieved and developed in the most natural way through the principles and practices of the learning organization. In addition to the ISO 9000 standards, organizations also use other well-known managerial references, including performance excellence models and many various management system standards of the specific disciplines. All these may be seen as sub-domains within the ISO 9004 framework. ISO 9004 also can be used for diverse TQM and sustainability implementations.</p> <p>This article is based on the authors’ long experience in the practical promotion and application of the ISO 9000 standard in different kinds of organizations. The first author of the article has involved in the international drafting process of the ISO 9004 standard-editions since the 1980s. He also was a co-writer of a similar ISO 9004 article about twenty years ago. That article has been publicly available on the Internet, and its over one thousand recent readers evidence a growing interest in this standard. Moreover, after 2000, ISO 9004 standard has been revised twice and rewritten completely recently. Hence, it is well-founded to re-examine this subject again in this article.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00An investigation of wire offset and surface morphology of Die Steel D-3 on Wire EDM by using RSM-CCD<abstract> <title style='display:none'>Abstract</title> <p>The work investigated the effect on wire offset and surface morphology, with input process parameters as peak current, pulse on time, wire tension over Die Steel D3. Some of experiments were performed by using response surface methodology (RSM) as the design of experiment with central composite design (CCD) technique for the analysis. The ANOVA results annotate that the model is significant. Wire Tension and peak current are observed to have major impact on wire offset during machining operation and surface morphology. The scanning electron microscope (SEM) images confirmed that the thermal stresses produced during the machining of the workpiece resulted in the development of microcracks, craters and spherical module. Due to higher thermal gradient i.e., higher peak current and pulse on-time larger cracks and melted deposits were observed.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Production potential of biodiesel, methane and electricity in the largest steamed rice industry in Rio Grande do Sul, Brazil: case study<abstract> <title style='display:none'>Abstract</title> <p>The potential for energy production from effluents and husks generated in grain processing in the rice parboiling industries in Brazil is capable of promoting energy self-sufficiency in the sector, through the production and use of syngas and biogas. However, the production of methane from residues of the rice parboiling industries is still little explored by academic studies, in general studies on the potential of methane production by this same type of effluent are found in the south of the country, however, the same is not true for the production of biodiesel from rice bran oil. The objective of this study was to determine the production potential of biodiesel, methane and electric energy of the largest parboiled rice industry in Rio Grande do Sul, located in the southern region of the country. According to this study, the rice parboiling industry located in Rio Grande do Sul, Brazil, has a production potential of 1.2∙10<sup>2</sup> m<sup>3</sup>/day of biodiesel, 2.93∙10<sup>4</sup> Nm<sup>3</sup>/day of methane and 1.89∙10<sup>5</sup> kWh/day of electricity. Despite being a significant and high potential, which may reduce the financial expenses of the industry regarding the purchase of energy from concessionaires, it is not able to promote its energy self-sufficiency. At the same time, it would be necessary to add the energy production potential of the rice husk gasification syngas highlighted in other studies</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Influence of laser texturing on tribological properties of DLC coatings<abstract> <title style='display:none'>Abstract</title> <p>The work presents the use of laser texturing of DLC coatings to improve tribological properties. The coatings were applied by the PVD method to the rings made of 4H13 steel. The surface texturing was performed with the TruMICRO 5325c picosecond laser with the radiation wavelength λ = 343 nm. The surface microstructure analysis, surface microgeometry and microhardness measurements and tribological tests were carried out. The problem presented in the paper can be used to extend the knowledge of the areas of application of DLC coatings, especially in sliding friction pairs.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00The concept of operation and production control<abstract> <title style='display:none'>Abstract</title> <p>The theoretical aim of the paper is to analyses the main function and concept of production control in operation management. The empirical aim of the paper is to investigate polish production firm opinion about factors affecting production planning and control and also functions of production planning and control. Production control is very important in every factory, and every aspect of operation and production management especially in times of Industry 4.0 conditions. In the paper we presented all classical seven task of production management control. Also there is in the paper an analysis of main factors affecting production control in industrial organization. In the paper we analysed the problems connected with production control. Nowadays in the conditions of Industry 4.0 this is very important concept because the increasing level of digitalization of all industrial processes leads to possibility of detailed analysis of all processes and better level of control. Operation managers should have good level of knowledge about production control and especially quality control. They can use in this many new information tools like statistical methods and artificial intelligence. Especially we think that in the future many function of production control would be assisted by artificial intelligence. We also in the paper give results of research conducted on example of 30 polish production organizations located in Silesia region.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Simulation of boronizing kinetics of ASTM A36 steel with the alternative kinetic model and the integral method<abstract> <title style='display:none'>Abstract</title> <p>In this study, two different mathematical models have been proposed for estimating the diffusivities of boron in the Fe<sub>2</sub>B layer on ASTM A36 steel in the range of 1173 to 1273 K with exposure times of 2 to 8 h. The boride incubation period required for the formation of such a layer was constant regardless of the boriding conditions. In both approaches, the boron diffusivity in the iron phase was considered in an unsaturated matrix. The first approach was derived from the mass balance equation at the (Fe<sub>2</sub>B/substrate) interface while the second approach employed the integral diffusion model. The calculated values of boron activation energies for ASTM A36 steel were found to be very comparable for the two approaches (161.65 and 160.96 and kJ mol<sup>-1</sup>). Afterwards, these values of activation energy were confronted with the results from the literature. Experimental validation of these two approaches has been done by comparing the experimental value of Fe<sub>2</sub>B layer thickness measured at 1123 K for 2.5 h with the simulated values. Finally, the predicted values of Fe<sub>2</sub>B layer thickness were in line with the experimental measurement.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Environmentally assisted cracking in the low pressure superheated hydrogen steam<abstract> <title style='display:none'>Abstract</title> <p>Low pressure superheated H<sub>2</sub>-steam appears to be an interesting alternative to pressurized water environments, since it is capable of performing accelerated environmentally assisted cracking (EAC) experiments for nickel base and stainless steel alloys. Constant Extension Rate Tensile (CERT) tests were performed with displacement rates of 2×10<sup>-6</sup> or 2×10<sup>-8</sup> ms<sup>-1</sup> at 350, 400, 440 and 480 °C on flat tapered specimens of Type 316L austenitic stainless steel. The tapered shape allows the determination of crack initiation over a range of stresses and strains simultaneously on one specimen and therefore the threshold stress value was obtained. The environment was 6 times more oxidizing than the dissociation pressure of NiO. The acquired mechanical properties are summarized and threshold stresses for EAC crack initiation are evaluated.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Investigation on the microstructure, microhardness, and tribological behavior of AA1100-hBN surface composite<abstract> <title style='display:none'>Abstract</title> <p>Aluminum alloy AA1100 has less wear resistance and mechanical properties than that of other aluminum alloys. This research work is on the fabrication of surface composites of AA1100 alloy by friction stir processing (FSP). The surface composites are fabricated by reinforcing hBN (hexagonal Boron Nitride) in AA1100 alloy to improve the mechanical and tribological properties. The influence of process parameters, rotational speed (rpm), and transverse speed (mm/min) on the microstructural evolution and properties of the fabricated surface composites is investigated.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Terephthalohydrazide and isophthalo- hydrazide as new corrosion inhibitors for mild steel in hydrochloric acid: Experimental and theoretical approaches<abstract> <title style='display:none'>Abstract</title> <p>Most organic corrosion inhibitors have polar groups through which the molecule can be adsorbed strongly or specifically on the metal surface. In this investigation, terephthalo- hydrazide and isophthalohydrazide were synthesized as corrosion inhibitors, and their corrosion-inhibiting properties on mild steel were evaluated in a corrosive environment by weight loss measurements. The results of corrosion experiments revealed that terephthalohydrazide and isophthalohydrazide as inhibitors controlled or reduced corrosion through adsorption mechanism and showed inhibitive efficiencies of 96.4 % and 97.2 %, respectively, at the optimum concentration of 0.5 mM. The surface morphology of the metal was evaluated by scanning electron microscopy. The terephthalohydrazide or isophthalohydrazide molecules were adsorbed on the mild steel surface, and the process of adsorption follows chemical adsorption. Quantum chemical calculations of the tested corrosion inhibitors were consistent with the experimental observations.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Contribution to the study of improving the aesthetics of the smile by repairing and reshaping the incisors with composite materials.<abstract> <title style='display:none'>Abstract</title> <p>Introduction. Dental aesthetics, although it seems something relative and difficult to evaluate, it is governed by a series of laws and rules that connect the dental disciplines, creating a unitary whole. It is structured by rules, perfected by artistic sense and by the inclination towards beauty of all specialists in dento-facial cosmetics.</p> <p>The aim of the study is to highlight an overview of aesthetic factors to consider when restoring anterior teeth with direct composite materials.</p> <p>Material and methods. A total of 25 patients were included in the study where the anterior teeth were restored using Gradia Direct Anterior (from GC) and Filtek Z550 (from3M-ESPE) composite kits, in perfect isolation using rubber damn, with a separate appointment after 24 hours for the polishing step, for which Rainbow Kit Technic and polishing Platina Hi-Gloss (from Prevest) paste were used. While the replacement of the tooth defect, we ensured that the composite increment, which we used should not be more than 2mm in thickness, and light cured for 20 seconds as the producer recommends. In none of all tooth shape modification (elongation in incisal zone) we did not modify the occlusion, by eliminating all premature contacts. All patients included in the study have signed the informed consent and agreed to participate in this research.</p> <p>Results. From a total of 25 patients, we repaired 20 central incisors with the mesial (18 cases) or distal (2 cases) angles fractured, in different accidents, 5 cases with diastema by small shape of the crown or malposition of one of the central incisors.</p> <p>Conclusions. Restoring the incisal angle or the incisal edge and refining a natural and improved smile of the patient is e very frequent dental intervention, especially nowadays when aesthetics plays an important role in the social society.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Efficiency of different instruments used for composite filling polishing.<abstract> <title style='display:none'>Abstract</title> <p>Introduction: Improper finishing and polishing of fillings leads to surface roughness of the restoration which leads to excessive plaque accumulation, gingival irritation, increased surface staining and poor aesthetics of restored teeth. Therefore, it is essential to use polishing instruments and pastes as a final step of simple caries treatment in order to achieve optimal long-time results. The aim of this study is to evaluate the efficiency of 4 different finishing and polishing instruments used for surface smoothening of aesthetic restorative materials in vitro. Materials and methods: 40 composite (Reality X) samples were prepared in vitro. Their surface irregularities were measured along 3 diagonals before and after polishing. Sof-Lex discs (3M Espe), rubber cones (Kenda), Arkansas stone (Fino) and polishing paste and a professional toothbrush (Kerr) were used for polishing. Each sample was polished under 5N pressure for 30 seconds at 3000 rpm. The surface roughness was than measured using a profilometer. Statistic analysis was performed using ANOVA and unpaired T-tests, the significance level was set at a value of p&lt;0.05. Results: Based on the mean values, the smallest roughness was found in the control group- 0.11, while the highest in the rubber polishers and Arkansas stone group- 0.47 and 0.48. The values for the Sof-Lex disc group and the polishing paste-toothbrush group were 0.40 and 0.39. Statistical analysis showed no significant differences between the four groups. Conclusion: It is mandatory to use polishing tools in order to obtain a smooth surface of the restoration and avoid the unwanted long-term complications. Polishing using brush and abrasive paste produced the smoothest surface of the composite.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Fear and dental anxiety in children: a study of the contributing factors.<abstract> <title style='display:none'>Abstract</title> <p>Introduction: Dental fear and anxiety are an important issue affecting children’s oral health and clinical management, and also an insufficiently studied subject in dentistry.</p> <p>Aim of the study: The aim of this study was to better understand the child patient - dentist versus dentist - child patient relationship and study the dental fear and anxiety of children in order to improve the dental office practice. Material and methods: In this study a personalized questionnaire was created and applied on a number of 333 children, in 4 schools from Mures county, Romania, on girls and boys between the ages of 8 and 13. The questionnaires used emoticons alongside words in order to better determine the state of anxiety created by the dental appointment and everything that it entails. All data and results obtained were analyzed using Excel and Graph Pad Prism 5.0 software.</p> <p>Results: Out of 333 patients, 133 subjects (40%) were 8-10-year-old, 143 subjects (42.9%) 11 - 13 years and 57 subjects (17.1%) were over 14 years. 175 girls (52.6%) and 158 boys (47.4%) demonstrated their courage and desire in participating in our study. It was determined that fear of dental appointments was caused in children over 14 years of age. The state of relaxation is generally enjoyed by urban children (45%) and those aged 11-13 years (37.1%); the percentage of boys in this category is an interesting aspect (40.5%).</p> <p>Conclusion: Dental anxiety is multifactorial and is far more complex than can be explained by a single contributing factor. The direct involvement of the child from the perspective of maintaining dental health, leads to the elimination of the state of fear and anxiety. Regular visits to the dental office, on the initiative of the child patient itself can reduce the anguish.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Geostatistical analysis of spatial variability of the liquefaction potential – Case study of a site located in Algiers (Algeria)<abstract><title style='display:none'>Abstract</title><p>The city of Algiers (Algeria) is a highly seismic area, and therefore, soil liquefaction poses a major concern for structures resting on sandy soil. A campaign of 62 static penetration tests or cone penetrometer tests (CPT) was carried out on a site located in the commune of Dar El Beïda in Algiers. The soil Liquefaction Potential Index (LPI) values were assessed, for each borehole, based on the simplified procedure of Seed and Idriss. On the other hand, the geographic information system and geostatistical analysis were used to quantify the risk of soil liquefaction at the studied site. It is worth mentioning that the (LPI) was taken as a regionalized variable. In addition, the experimental variogram was modeled on the basis of a spherical model. Also, the interpolation of the LPI values in the unsampled locations was performed by the Kriging technique using both isotropic and anisotropic models. Kriging standard deviation maps were produced for both cases. The cross-validation showed that the anisotropic model exhibited a better fit for the interpolation of the values of the soil liquefaction potential. The results obtained indicated that a significant part of the soil is liable to liquefy, in particular in the northwestern region of the study area. The findings suggest that there is a proportional relationship between the risk of liquefaction and the increase or decrease in seismic acceleration.</p></abstract>ARTICLE2021-06-11T00:00:00.000+00:00T Dependence of the Mechanical Properties on the Microstructural Parameters of WC-Co<abstract> <title style='display:none'>Abstract</title> <p>The effect of binder content and WC grain size on the mechanical properties is widely investigated in literature. An increase in binder amount and WC grain size leads to a decrease in hardness and an increase in fracture toughness. Actually, these correlations are related to the influence of binder content and WC grain size through the contiguity and mean binder free path, which are the microstructural parameters that affect the mechanical properties. The aim of this study is to verify the dependence of the two microstructural parameters that govern the WCCo mechanical behaviour, namely the contiguity and mean binder free path, on the mechanical properties of an extended range of WC-Co samples, which differ in terms of Co content and tungsten carbide grain size.</p> </abstract>ARTICLE2020-06-15T00:00:00.000+00:00en-us-1