Search results for: material management

Authors: Guntur Bagus Pamungkas

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As part of a tropical country that is normally rich in forest land areas, Indonesia has always been in the world's spotlight due to its significantly increasing process of deforestation. In one hand, it is related to the mainstay for maintaining the sustainability of the earth's ecosystem functions. On the other hand, they also cover the various potential sources of the global economy. Therefore, it can always be the target of different scale of investors to excessively exploit them. No wonder the emergence of disasters in various characteristics always comes up. In fact, the deforestation phenomenon does not only occur in various forest land areas in the main islands of Indonesia but also includes Java Island, the most densely populated areas in the world. This island only remains the forest land of about 9.8% of the total forest land in Indonesia due to its long history of it, especially in Central Java Province, the most densely populated area in Java. Again, not surprisingly, this province belongs to the area with the highest frequency of disasters because of it, landslides in particular. One of the areas that often experience it is Banjarnegara District, especially in mountainous areas that lies in the range from 1000 to 3000 meters above sea level, where the remains of land forest area can easyly still be found. Even among them still leaves less untouchable tropical rain forest whose area also covers part of a neighboring district, Pekalongan, which is considered to be the rest of the world's little paradise on Earth. The district's landscape is indeed beautiful, especially in the Dieng area, a major tourist destination in Central Java Province after Borobudur Temple. However, annually hazardous always threatens this district due to this landslide disaster. Even, there was a tragic event that was buried with its inhabitants a few decades ago. This research aims to find part of the concept of effective forest management through monitoring the presence of remaining forest areas in this area. The research implemented monitoring of deforestation rates using the Stochastic Cellular Automata-Markov Chain (SCA-MC) method, which serves to provide a spatial simulation of land use and cover changes (LULCC). This geospatial process uses the Landsat-8 OLI image product with Thermal Infra-Red Sensors (TIRS) Band 10 in 2020 and Landsat 5 TM with TIRS Band 6 in 2010. Then it is also integrated with physical and social geography issues using the QGIS 2.18.11 application with the Mollusce Plugin, which serves to clarify and calculate the area of land use and cover, especially in forest areas—using the LULCC method, which calculates the rate of forest area reduction in 2010-2020 in Banjarnegara District. Since the dependence of this area on the use of forest land is quite high, concepts and preventive actions are needed, such as rehabilitation and reforestation of critical lands through providing proper monitoring and targeted forest management to restore its ecosystem in the future.

Keywords: deforestation, populous area, LULCC method, proper control and effective forest management

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Authors: Masoud Mohammadpour, Nima Yazdian, Radovan Kovacevic

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The Oil and Gas industries are vigorously looking for new ways to increase the efficiency of their pipeline constructions. Besides the other approaches, implementing of new welding methods for joining pipes can be the best candidate on this regard. Hybrid Laser Arc Welding (HLAW) with the capabilities of high welding speed, deep penetration, and excellent gap bridging ability can be a possible alternative method in pipeline girth welding. This paper investigates the feasibility of applying the HLAW to join ASTM A106-B as the mostly used piping material for transporting high-temperature and high-pressure fluids and gases. The experiments were carried out on six-inch diameter pipes with the wall thickness of 10mm. AWS ER 70 S6 filler wire with diameter of 1.2mm was employed. Relating to this welding procedure, characterization of welded samples such as hardness, tensile testing and Charpy V-notch testing were performed and the results will be reported in this paper. In order to have better understanding about the thermal history and the microstructural alterations caused by the welding heat cycle, a comprehensive Finite Element (FE) model was also conducted. The obtained results have shown that the Gas Metal Arc Welding (GMAW) procedure with the minimum number of 5 passes to complete the wall thickness, was reduced to only single pass by using the HLAW process with the welding time less than 15s.

Keywords: finite element modeling, high-temperature service, hybrid laser/arc welding, welding pipes

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Authors: John Abraham, Ramesh Saravana Kumar, Francis, Xavier, Deepak Mathew

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Broiler slaughter waste has become a major source of pollution throughout the world. Utilization of broiler slaughter waste by dry rendering process produced Rendered Chicken Oil (RCO) a cheap raw material for biodiesel production and Carcass Meal a feed ingredient for pets and fishes. Conversion of RCO into biodiesel may open new vistas for generating wealth from waste besides controlling the major havoc of environmental pollution. A two-step process to convert RCO to good quality Biodiesel was invented. Acid catalysed esterification of FFA followed by base catalysed transesterification of triglycerides was carried out after meticulously standardising the methanol molar ratio, catalyst concentration, reaction temperature and reaction time to obtain the maximum biodiesel yield of 97.62% and lowest glycerol yield of 6.96%. RCO biodiesel blended was tested in a Mahindra Scorpio CRDI engine. The results revealed that the blending of commercial diesel with 20% RCO biodiesel lead to less engine wear, a quieter engine and better fuel economy. The better lubricating qualities of RCO B20 prevented over heating of engine, which prolongs the engine life. The blending of biodiesel at 20% to commercial diesel can reduce the import of costly crude oil and simultaneously, substantially reduce the engine emissions as proved by significantly lower smoke levels, thus mitigating climatic changes.

Keywords: broiler waste, rendered chicken oil, biodiesel, engine testing

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Authors: P. Mukhopadhyay, N. C. Dey

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Occupational health hazard is a very common term in every emerging country. Along with the unorganized sector, most organized sectors including government industries are suffering from this affliction. In addition to workload, the seasonal changes also have some impacts on working environment. With this focus in mind, one hundred male industrial workers, who are directly involved to the task of Periodic Overhauling (POH) in a fabricating workshop in the public domain are selected for this research work. They have been studied during work periods throughout different seasons in a year. For each and every season, the participants working heart rate (WHR) is measured and compared with the standards given by different national and internationally recognized agencies i.e., World Health Organization (WHO) and American Conference of Governmental Industrial Hygienists (ACGIH) etc. The different environmental parameters i.e. dry bulb temperature (DBT), wet bulb temperature (WBT), globe temperature (GT), natural wet bulb temperature (NWB), relative humidity (RH), wet bulb globe temperature (WBGT), air velocity (AV), effective temperature (ET) are recorded throughout the seasons to critically observe the effect of seasonal changes on the WHR of the workers. The effect of changes in environment to the WHR of the workers is very much surprising. It is found that the percentages of workers who belong to the ‘very heavy’ workload category are 83.33%, 66.66% and 16.66% in the summer, rainy and winter seasons, respectively. Ongoing undertaking of this type of job profile forces the worker towards occupational disorders causing absenteeism. This occurrence results in lower production rates, and on the other hand, costs due to medical claims also weaken the industry’s economic condition. In this circumstance, the authors are trying to focus on some remedial measures from the ergonomic angle by proposing a new work/ rest regimen and introducing engineering controls along with management controls which may help the worker, and consequently, the management also.

Keywords: workload, working heart rate, occupational health hazard, industrial worker

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Authors: Joelle Hawa, Michael Gilding

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The role of interest as a driver of action has been an on-going debate in the sociological sciences. This paper shows evidence as to how economic actors frame their environment in terms of interests and goals to take action. It introduces the concept of 'dynamic actor compass', a cognitive tool that is socially contingent and allows economic actors to navigate their environment, evaluate the level of alignment of interests and goals with other players, and decide whether or not they are willing to rely on, collaborate or partner with others in the field. The paper builds on Kaplan’s model of framing contests and integrates Max Weber’s interests, and ideas construct as well as Beckert’s concept of fictional expectations. The author illustrates this conceptual framework in the case of MedTech entrepreneurs’ capital raising activities in Australia. The study adopts a grounded theory methodology, running in-depth interviews with 24 MedTech entrepreneurs in order to examine their decision-making processes and actions to finance their innovation trajectory. The findings show that participants take into account material and ideal interests and goals that they impose adapt or negotiate with other actors in their environment. These interactions affect the way MedTech entrepreneurs perceive other funders in the field, influencing their capital raising strategies.

Keywords: expectations, financing innovation, frames, goals, interest-oriented action, managerial cognition

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Authors: Wenxin Mei, Jinhua Sun, Qingsong Wang

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The volume expansion of lithium-ion batteries is mainly induced by intercalation induced stress within the negative electrode, resulting in capacity degradation and even battery failure. Stress generation due to lithium intercalation into graphite particles is investigated based on an electrochemical-mechanical model in this work. The two-dimensional model presented is fully coupled, inclusive of the impacts of intercalation-induced stress, stress-induced intercalation, to evaluate the lithium concentration, stress generation, and displacement intra and inter-particle. The results show that the distribution of lithium concentration and stress exhibits an analogous pattern, which reflects the relation between lithium diffusion and stress. The results of inter-particle stress indicate that larger Von-Mises stress is displayed where the two particles are in contact with each other, and deformation at the edge of particles is also observed, predicting fracture. Additionally, the maximum inter-particle stress at the end of lithium intercalation is nearly ten times the intraparticle stress. And the maximum inter-particle displacement is increased by 24% compared to the single-particle. Finally, the effect of graphite particle arrangement on inter-particle stress is studied. It is found that inter-particle stress with tighter arrangement exhibits lower stress. This work can provide guidance for predicting the intra and inter-particle stress to take measures to avoid cracking of electrode material.

Keywords: electrochemical-mechanical model, graphite particle, lithium concentration, lithium ion battery, stress

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Authors: Hendrik Bernard Van Der Walt, Frik Van Niekerk

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Fuel models render a reduction in BOL when thorium is added to a reactor core. Thorium emulates the role of a fertile poison, and is beneficial for reducing beginning of cycle (BOC) excess reactivity. In spite of the build-up of 233U over the duration of a fuel cycle, the effects of fuel reloading have a significant impact on fuel viability, especially in the case of heterogeneous thorium-based fuels. The most common practice of compensating for the reduction of BOC reactivity is the addition of fissile isotopes (uranium fuel with increased enrichment or plutonium). This study introduces a heterogeneous thorium-based fuel with minimal fissile isotope additions. A pseudo reloading scheme was developed for numerical simulations of an infinite reactor based on the North-Anna 1 reactor operating in Virginia, USA. Use of this reloading pattern allows new thorium-based fuel to be loaded into the reactor model as part of a phasing in strategy at the end of any conventional reactor cycle. Results demonstrate the effects of thorium-based fuel on fuel cycle characteristics such as fuel cycle length, neutron economy and material matrix. Application of the above mentioned approach delivered promising results and presents a heterogeneous thorium-based fuel which could replace conventional fuel of typical, currently operating (or future) reactors without the need for expensive reactor redesign or fuel recycling strategies.

Keywords: nuclear fuel, nuclear characteristics, nuclear fuel cycle, thorium-based fuel, heterogeneous design, fuel reloading

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Authors: Andre Wittenborn, Jarek Krajewski

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Trauma-related sadness in speech can alter the voice in several ways. The generation of non-linear aerodynamic phenomena within the vocal tract is crucial when analyzing trauma-influenced speech production. They include non-laminar flow and formation of jets rather than well-behaved laminar flow aspects. Especially state-space reconstruction methods based on chaotic dynamics and fractal theory have been suggested to describe these aerodynamic turbulence-related phenomena of the speech production system. To extract the non-linear properties of the speech signal, we used the time delay embedding method to reconstruct from a scalar time series (reconstructed phase space, RPS). This approach results in the extraction of 7238 Features per .wav file (N= 47, 32 m, 15 f). The speech material was prompted by telling about autobiographical related sadness-inducing experiences (sampling rate 16 kHz, 8-bit resolution). After combining these features in a support vector machine based machine learning approach (leave-one-sample out validation), we achieved a correlation of r = .41 with the well-established, self-report ground truth measure (RATS) of post-traumatic stress disorder (PTSD).

Keywords: non-linear dynamics features, post traumatic stress disorder, reconstructed phase space, support vector machine

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Authors: Guizella Rocabado, Cassidy Wilkes

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It is well known that chemistry is one of the most feared courses in college. Although many students enjoy learning about science, most of them perceive that chemistry is “too difficult”. These perceptions of chemistry result in many students not considering Science, Technology, Engineering, and Mathematics (STEM) majors because they require chemistry courses. Ultimately, these perceptions are also thought to be related to high attrition rates of students who begin STEM majors but do not persist. Students perceived costs of a chemistry class can be many, such as task effort, loss of valued alternatives, emotional, and others. These costs might be overcome by students’ interests and goals, yet the level of perceived costs might have a lasting impact on the students’ overall perception of chemistry and their desire to pursue chemistry and other STEM careers in the future. In this mixed methods study, we investigated task effort and emotional cost, as well as a mastery or performance goal orientation, and the impact these constructs may have on achievement in general chemistry classrooms. Utilizing cluster analysis as well as student interviews, we investigated students’ profiles of perceived cost and goal orientation as it relates to their final grades. Our results show that students who are well prepared for general chemistry, such as those who have taken chemistry in high school, display less negative perceived costs and thus believe they can master the material more fully. Other interesting results have also emerged from this research, which has the potential to have an impact on future instruction of these courses.

Keywords: chemistry education, motivation, affect, perceived costs, goal orientations

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Authors: Eva Stefanovska, Estefania Cuenca, Aleksandra Momirov, Monika Fidanchevska, Liberato Ferrara, Emilija Fidanchevski

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Silica is used in construction materials as a part of natural raw materials or as an additive in powder form (micro and nano dimensions). SiO₂ particles in cement act as centers of nucleation, as a filler or as pozzolan material. In this regard, silica improves the microstructure of cementitious composites, increases the mechanical properties, and finally also results into improved durability of the final products. Improved properties of cementitious composites may lead to better structural efficiency, which, together with increased durability, results into increased sustainability signature of structures made with this kind of materials. The aim of the present work was to investigate the influence of silica on the properties of cement. Fly ash (as received and mechanically activated) and synthetized silica (sol-gel method using TEOS as precursor) was used in the investigation as source of silica. Four types of cement mixtures were investigated (reference cement paste, cement paste with addition of 15wt.% as-received fly ash, cement paste with 15 wt.% mechanically activated fly ash and cement paste with 14wt.% mechanically activated fly ash and 1 wt.% silica). The influence of silica on setting time and mechanical properties (2, 7 and 28 days) was followed. As a matter of fact it will be shown that cement paste with composition 85 wt. % cement, 14 wt.% mechanically activated fly ash and 1 wt. % SiO₂ obtained by the sol-gel method was the best performing one, with increased compressive and flexure strength by 9 and 10 % respectively, as compared to the reference mixture. Acknowledgements: 'COST Action CA15202, www.sarcos.eng.cam.ac.uk'

Keywords: cement, fly ash, mechanical properties, silica, sol-gel

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Authors: Aynura Valiyeva, Basil John Thomas

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Intra-firm communication is critical for building synergy amongst internal business units of a firm, where employees from various functional departments and ranks incorporate their decision-making, understanding of organizational objectives, as well as common norms and culture for better organizational effectiveness. This study builds on and assesses a framework of the causes and consequences of effective communication in business interactions between customer and supplier firms, and the path for efficient communication within a firm. The proposed study’s structural equation modeling (SEM) analysis based on 352 sample responses collected from firm representatives at different job positions ranging from marketing to logistics operations, reveals that, in the frame of reference of intra-organizational communication, organization characteristics and shared values, top management support and style of leadership, as well as information technology, are all significantly related to communication effectiveness. Furthermore, the frequency and variety of interactions enhance the outcome of communication, that improves a company’s performance. The results reveal that cultural factors are significantly related to communication effectiveness, as well as the shared beliefs and goals. In terms of organizational factors, leadership style, top management support and information technology are significant determinants of effective communication. Among the contextual factors, interaction frequency and diversity are found to be priority factors. This study also tests the relationship between supplier and supplier firm performance in the context of communication effectiveness, and finds that they are closely related, when trust and commitment is built between business partners. When firms do business in other multicultural contexts, language and shared values with destination country must be considered significant elements of communication process.

Keywords: business performance, intra-firm communication, inter-firm communication, structural equation modeling

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Authors: Roham Rafiee, Behzad Mazhari

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Composite structures, having incredible properties, have gained considerable popularity in the last few decades. Among all types, polymer matrix composites are being used extensively due to their unique characteristics including low weight, convenient fabrication process and low cost. Having polymer as matrix, these type of composites show different creep behavior when compared to metals and even other types of composites since most polymers undergo creep even in room temperature. One of the most challenging topics in creep is to introduce new techniques for predicting long term creep behavior of materials. Depending on the material which is being studied the appropriate method would be different. Methods already proposed for predicting long term creep behavior of polymer matrix composites can be divided into five categories: (1) Analytical Modeling, (2) Empirical Modeling, (3) Superposition Based Modeling (Semi-empirical), (4) Rheological Modeling, (5) Finite Element Modeling. Each of these methods has individual characteristics. Studies have shown that none of the mentioned methods can predict long term creep behavior of all PMC composites in all circumstances (loading, temperature, etc.) but each of them has its own priority in different situations. The reason to this issue can be found in theoretical basis of these methods. In this study after a brief review over the background theory of each method, they are compared in terms of their applicability in predicting long-term behavior of composite structures. Finally, the explained materials are observed through some experimental studies executed by other researchers.

Keywords: creep, comparative study, modeling, composite materials

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Authors: Renu Sisodia

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This paper attempted to explore and explain the local level river water conflicts in the larger context of state - society relations. This study also covered causes of local level river water conflicts in the catchment area of Bandi and Arvari river of Rajasthan. The focus of the study was on the emergence of community driven, decentralised management of river water bodies and strategies used by local communities to protect and manage river water conflicts. The research is conducted through the process of designing a framework based on essential theoretical and practical findings supported by primary and secondary data. Two in depth case study is conducted to understand the phenomenon in depth. The first field site is Bandi River of Pali district, which is about the struggle between textile industries, community and the State government in which water pollution is said to be one of the driving force of the conflict. Finding shows that the state is supporting textile industries in Pali district have not been adherent to the environmental ethics. Present legal infrastructure and local institutions fail to resolve the serious problem of water pollution in Bandi River and its adverse impact on the local community as a result local community resistance against the local administration and the state government. The second case illustrates the plight of Arvari River in Alwar district. Tussle for the ownership of fisheries between local community, the private fish contractor and State government has been the main bone of contestation. To resolve this conflict local community formed conflict management mechanism named as Arvari Parliament. Arvari Parliament has its own principle and rules to resolve water conflicts related to ownership of the river and use of the river water. The research findings also highlight the co-existence between conventional and modern practices in resolving conflicts.

Keywords: water, water pollution, water conflicts, water scarcity, conflict resolution, local community

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Authors: Marta Tryzna, Shahd Al Shammari

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Though Modern Standard Arabic (MSA) is the only official language in GCC states, including Kuwait, and traditionally the preferred vehicle for literacy in the Arab countries, recent studies in Qatar and the UAE observe a growing role of English, particularly in literacy and knowledge transmission contexts. The present study examines the attitudes to Arabic and English and the use of both languages in literacy-related domains based on a sample of bilingual Arabic-English undergraduates (N=522) at a private university with EMI in Kuwait. The results indicate that Arabic (Kuwaiti dialect) is associated with familial interactions, Arabic-English bilingualism predominates in interactions with classmates, friends, on social media and at work, while English is prevalent in literacy-related contexts such as reading books, magazines, or online material, domains traditionally associated with MSA. Attitudes towards Arabic and English are equally positive according to the majority of the respondents, who report being comfortable expressing themselves and projecting their identity in both languages. No statistically significant differences were found comparing the importance of Arabic and English in the sample. Future trends were identified based on high agreement on the importance of speaking English with children and low agreement on speaking only Arabic at home. The study corroborates recently observed trends in the GCC favoring bilingualism across personal, academic and professional domains, with English becoming the preferred language of literacy among young bilingual Kuwaitis.

Keywords: bilingual, English, Arabic, EMI, identity

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Authors: M. I. Benamrani, H. Benamrani

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In the research to replace silicon and other thin-film semiconductor technologies and to develop long-term technology that is environmentally friendly, low-cost, and abundant, there is growing interest today given to organic materials. Our objective is to prepare polymeric layers containing metal particles deposited on a surface of semiconductor material which can have better electrical properties and which could be applied in the fields of nanotechnology as an alternative to the existing processes involved in the design of electronic circuits. This work consists in the development of composite materials by complexation and electroreduction of copper in a film of poly (pyrrole benzoic acid). The deposition of the polymer film on a monocrystalline silicon substrate is made by electrochemical oxidation in an organic medium. The incorporation of copper particles into the polymer is achieved by dipping the electrode in a solution of copper sulphate to complex the cupric ions, followed by electroreduction in an aqueous solution to precipitate the copper. In order to prepare the monocrystalline silicon substrate as an electrode for electrodeposition, an in-depth study on its surface state was carried out using photoacoustic spectroscopy. An analysis of the optical properties using this technique on the effect of pickling using a chemical solution was carried out. Transmission-photoacoustic and impedance spectroscopic techniques give results in agreement with those of photoacoustic spectroscopy.

Keywords: photoacoustic, spectroscopy, copper sulphate, chemical solution

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Authors: Anna Triwijayati, Etsa Astridya Setiyati, Titik Desi Harsoyo

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Culture is the important determinant of human behavior and desire. Culture influences the consumer through the norms and values established by the society in which they live and reflect it. The cultural values of Javanese society certainly have united in the Javanese society behavior in consumption. This research is expected to give big enough theoretical benefits in the findings of cultural value in consumption in Javanese society. These can be an incentive in finding the local cultural value in many tribes in Indonesia, so one time, the local cultural value in Indonesia about consumption can be fundamental part in education and consumption practice in Indonesia. The approach used in this research is non positivist research or is known as qualitative approach. The method or type of research used in this research is ethnomethodology. The collection data is done in Central Java region. The research subject or informant is determined by the purposive technique by certain criteria determined by the researcher. The data is collected by deep interview and observation. Before the data analysis, the researcher does the storing method data stage and implements the data validity procedures. Then, the data is analyzed by the theme and interactive analysis technique. The Javanese Mataraman society has such consumption values such as has to be sufficient, be careful, economical, submit to the one who creates the life, the way life flow, and the present problem is thought in the present also. In the financial management for consumption, the consumer should have the simple life principles, has to be sufficient, has to be able to eat, has to be able to self-press, well-managed/diligent/accurate/careful, the open or transparent management, has the struggle effort, like to self-sacrifice and think about the future. The meaning of consumption value in family is centered to the submission and full-trust to God. These consumption values are applied in consumer behavior in self, family, investment and credit need in short term and long term perspective.

Keywords: values, consumer, consumption, Javanese Mataraman, ethnomethodology

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Authors: M. D. Levi, Netanel Shpigel, Sergey Sigalov, Gregory Salitra, Leonid Daikhin, Doron Aurbach

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We have developed an in-situ method for tracking ions adsorption into composite nanoporous carbon electrodes based on quartz-crystal microbalance (QCM). In these first papers QCM was used as a simple gravimetric probe of compositional changes in carbon porous composite electrodes during their charging since variation of the electrode potential did not change significantly width of the resonance. In contrast, when we passed from nanoporous carbons to a composite Li-ion battery material such as LiFePO4 olivine, the change in the resonance width was comparable with change of the resonance frequency (polymeric binder PVdF was shown to be completely rigid when used in aqueous solutions). We have provided a quantitative hydrodynamic admittance model of ion-insertion processes into electrode host accompanied by intercalation-induced dimensional changes of electrode particles, and hence the entire electrode coating. The change in electrode deformation and the related porosity modify hydrodynamic solid-liquid interactions tracked by QCM with dissipation monitoring. Using admittance modeling, we are able to evaluate the changes of effective thickness and permeability/porosity of composite electrode caused by applied potential and as a function of cycle number. This unique non-destructive technique may have great advantage in early diagnostics of cycling life durability of batteries and supercapacitors.

Keywords: Li-ion batteries, particles deformations, QCM-D, viscoelasticity

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Authors: Liu De-jun, Fu Jing, Zhang Rong, Luo Tian, Ma Ning

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Cs-137, the radioactive fission products of uranium, can be easily dissolved in water during the accident of nuclear power plant, such as Chernobyl, Three Mile Island, Fukushima accidents. The concentration of Cs in the groundwater around the nuclear power plant exceeded the standard value almost 10,000 times after the Fukushima accident. The adsorption capacity of Titanate nano-materials for radioactive cation (Cs+) is very strong. Moreover, the radioactive ion can be tightly contained in the nanotubes or nanofibers without reversible adsorption, and it can safely be fixed. In addition, the nano-material has good chemical stability, thermal stability and mechanical stability to minimize the environmental impact of nuclear waste and waste volume. The preparation of titanate nanotubes or nanofibers was studied by hydrothermal methods, and chemical kinetics of removal of Cs by nano-materials was obtained. The adsorption time with maximum adsorption capacity and the effects of pH, coexisting ion concentration and the optimum adsorption conditions on the removal of Cs by titanate nano-materials were also obtained. The adsorption boundary curves, adsorption isotherm and the maximum adsorption capacity of Cs-137 as tracer on the nano-materials were studied in the research. The experimental results showed that the removal rate of Cs-137 in 0.01 tons of waste water with only 1 gram nano-materials could reach above 98%, according to the optimum adsorption conditions.

Keywords: preparation, titanate, cs-137, removal, nuclear

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Authors: Jana Petru, Marie Kudrnova

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The use of technologies working with molten salts is conditioned by finding suitable construction materials that must meet several demanding criteria. In addition to temperature resistance, materials must also show corrosion resistance to salts; they must meet mechanical requirements and other requirements according to the area of use – for example, radiation resistance in Molten Salt Reactors. The present text describes an experimental device for studying the corrosion resistance of candidate materials in molten mixtures of salts and is a partial task of the international project ADAR, dealing with the evaluation of advanced nuclear reactors based on molten salts. The design of the device is based on a test exposure of Inconel 625 in the mixture of salts Hitec in a high temperature tube furnace. The result of the pre-exposure is, in addition to the metallographic evaluation of the behavior of material 625 in the mixture of nitrate salts, mainly a list of operational and construction problems that were essential for the construction of the new experimental equipment. The main output is a scheme of a newly designed gas-tight experimental apparatus capable of operating in an inert argon atmosphere, temperature up to 600 °C, pressure 3 bar, in the presence of a corrosive salt environment, with an exposure time of hundreds of hours. This device will enable the study of promising construction materials for nuclear energy.

Keywords: corrosion, experimental device, molten salt, steel

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Authors: Evgeniia V. Mekhonoshina, Vladimir Ya. Modorskii, Vasilii Yu. Petrov

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At present, vibrations of rotors of gas transmittal unit evade sustainable forecasting. This paper describes elastic oscillation modes in resilient supports and rotor impellers modeled during computational experiments with regard to interference in the system of gas-dynamic flow and compressor rotor. Verification of aeroelastic approach was done on model problem of interaction between supersonic jet in shock tube with deformed plate. ANSYS 15.0 engineering analysis system was used as a modeling tool of numerical simulation in this paper. Finite volume method for gas dynamics and finite elements method for assessment of the strain stress state (SSS) components were used as research methods. Rotation speed and material’s elasticity modulus varied during calculations, and SSS components and gas-dynamic parameters in the dynamic system of gas-dynamic flow and compressor rotor were evaluated. The analysis of time dependence demonstrated that gas-dynamic parameters near the rotor blades oscillate at 200 Hz, and SSS parameters at the upper blade edge oscillate four times higher, i.e. with blade frequency. It has been detected that vibration amplitudes correction in the test points at magnetic bearings by aeroelasticity may correspond up to 50%, and about -π/4 for phases.

Keywords: Centrifugal compressor, aeroelasticity, interdisciplinary calculation, oscillation phase displacement, vibration, nonstationarity

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Authors: Farzad Doostishoar, Abbas Pardakhty, Abdolreza Hassanzadeh, Sudeh salarpour, Elham Sharif

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Background: Sericin is a protein extracted from silk and has antioxidant, antimicrobial, antineoplastic, wound healing and moisturizing properties. Different cosmetic formulation of sericin is available in different countries such as Japan and the other south-eastern Asian countries. We formulated and evaluated the sunscreen properties of topical formulations of sericin by an in vitro method. Method: Niosomes composed of sorbitan palmitate (Span 40), polysorbate 40 (Tween 40) and cholesterol (300 µmol, 3.5:3.5:3 molar ratio) were prepared by film hydration technique. Sericin was dissolved in normal saline and the lipid hydration was carried out at 60°C and the niosomes were incorporated in a Carbomer gel base. A W/O cream was also prepared and the release of sericin was evaluated by using Franz diffusion cell. Particle size analysis, sericin encapsulation efficiency measurement, morphological studies and stability evaluation were done in niosomal formulations. SPF was calculated by using Transpore tape in vitro method for both formulations. Results: Niosomes had high stability during 6 months storage at 4-8°C. The mean volume diameter of niosomes was less than 7 µm which is ideal for sustained release of drugs in topical formulations. The SPF of niosomal gel was 25 and higher than sericin cream with a diffusion based release pattern of active material. Conclusion: Sericin can be successfully entrapped in niosomes with sustained release pattern and relatively high SPF.

Keywords: sericin, niosomes, sun protection factor, cream, gel

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Authors: Bamidele Wale-Oshinowo, Doris Akyere Boateng, Lebura Sorbarikor

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Women play significant roles when it comes to the survival of family businesses; however, their efforts are less acknowledged across the developing world. In the case where these businesses are started by husbands, women in many instances work as hard as the men to build up the business. In spite of this, the benefits women receive are not equal to their inputs. For instance, the profits accruing from ownership of these businesses are mainly enjoyed by husbands, as they are deemed to be the legal owners of family businesses in most developing economies. Though the number of women involvement in the ownership, management, and direction of family businesses keeps increasing over the years, their efforts sometimes are ‘invisible’ and not rewarded. Using a phenomenological approach, this study purposively selected 20 businesswomen each from Ghana and Nigeria for in-depth interviews on the different roles they play in ensuring the success of their family businesses (FBs). This study also explored the challenges and opportunities that these women have within their family businesses. Among the major findings of this study is the important strategic direction that women give in terms of providing both tangible and intangible resources such as transfer of transit knowledge to the next generation. Women were also found to play a significant role in the implementation of entrepreneurial orientation within small family businesses in Ghana and Nigeria. However, the study revealed that women experience various challenges as stakeholders in family businesses, among which are: work-life balance issues, succession issues, and culture-related presuppositions about gender roles both within the business and in their families. In the light of the study’s findings, critical recommendations made include encouraging founders and/or owners of family businesses to create a conducive and viable platform for women to grow into key leadership positions within Family businesses; doing this would impact strongly on the growth rate of these form of businesses within the African Region.

Keywords: emerging economies, control, management, resources, strategy, women

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Authors: Guadalupe Stefanny Aguilar-Moreno, Miguel Angel Aguilar-Mendez, Teodoro Espinosa-Solares

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In the agricultural sector, one of the main emitters of greenhouse gases is manure management, which has been increased considerably in recent years. Biogas is an energy source that can be produced from different organic materials through anaerobic digestion (AD); however, production efficiency is still low. Several techniques have been studied to increase its performance, such as co-digestion, the variation of digestion conditions, and nanomaterials used. Therefore, the aim of this investigation was to evaluate the effect of magnetite nanoparticles (NPs) concentration, synthesized by co-precipitation, on the biogas and methane production in AD using chicken litter as a substrate. Synthesis of NPs was performed according to the co-precipitation method, for which a fractional factorial experimental design 25⁻² with two replications was used. The study factors were concentrations (precursors and passivating), time of sonication and dissolution temperatures, and the response variables were size, hydrodynamic diameter (HD) and zeta potential. Subsequently, the treatment that presented the smallest NPs was chosen for their use on AD. The AD was established in serological bottles with a working volume of 250 mL, incubated at 36 ± 1 °C for 80 days. The treatments consisted of the addition of different concentrations of NPs in the microcosms: chicken litter only (control), 20 mg∙L⁻¹ of NPs + chicken litter, 40 mg∙L⁻¹ of NPs + chicken litter and 60 mg∙L⁻¹ of NPs + chicken litter, all by triplicate. Methane and biogas production were evaluated daily. The smallest HD (49.5 nm) and the most stable NPs (21.22 mV) were obtained with the highest passivating concentration and the lower precursors dissolution temperature, which were the only factors that had a significant effect on the HD. In the transmission electron microscopy performed to these NPs, an average size of 4.2 ± 0.73 nm was observed. The highest biogas and methane production was obtained with the treatment that had 20 mg∙L⁻¹ of NPs, being 29.5 and 73.9%, respectively, higher than the control, while the treatment with the highest concentration of NPs was not statistically different from the control. From the above, it can be concluded that the magnetite NPs promote the biogas and methane production in AD; however, high concentrations may cause inhibitory effects among methanogenic microorganisms.

Keywords: agricultural sector, anaerobic digestion, nanotechnology, waste management

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Authors: Ljerka Kratofil Krehula, Martina Perlog, Jasmina Stjepanović, Vanja Gilja, Marijana Kraljić Roković, Zlata Hrnjak-Murgić

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The composite preparation of titanium dioxide and zinc oxide photocatalysts with the conductive polymers gives the opportunity to carry out the catalysis reactions not only under UV light but also under visible light. Such processes may efficiently use sunlight in degradation of different organic pollutants and present new design for wastewater treatment. The paper presents the preparation procedure, material characteristics and photocatalytic efficiency of polypyrrole/titanium dioxide and polypyrrole/zinc oxide composites (PPy/TiO2 and PPy/ZnO). The obtained composite samples were characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and thermogravimetric analysis (TGA). The photocatalytic efficiency of the samples was determined following the decomposition of Acid Blue 25 dye (AB 25) under UV and visible light by UV/Vis spectroscopy. The efficiency of degradation is determined by total organic carbon content (TOC) after photocatalysis processes. The results show enhanced photocatalytic efficiency of the samples under visible light, so the prepared composite samples are recognized as efficient catalysts in degradation process of AB 25 dye. It can be concluded that the preparation of TiO2 or ZnO composites with PPy can serve as a very efficient method for the improvement of TiO2 and ZnO photocatalytic performance under visible light.

Keywords: composite, photocatalysis, polypyrrole, titanium dioxide, zinc oxide

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Authors: P. Deepak Kumar, P. R. Maiti

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In recent years, sediment scour near bridge piers and abutment is a serious problem which causes nationwide concern because it has resulted in more bridge failures than other causes. Scour is the formation of scour hole around the structure mounted on and embedded in erodible channel bed due to the erosion of soil by flowing water. The formation of scour hole around the structures depends upon shape and size of the pier, depth of flow as well as angle of attack of flow and sediment characteristics. The flow characteristics around these structures change due to man-made obstruction in the natural flow path which changes the kinetic energy of the flow around these structures. Excessive scour affects the stability of the foundation of the structure by the removal of the bed material. The accurate estimation of scour depth around bridge pier is very difficult. The foundation of bridge piers have to be taken deeper and to provide sufficient anchorage length required for stability of the foundation. In this study, computational model simulations using a 3D Computational Fluid Dynamics (CFD) model were conducted to examine the mechanism of scour around a cylindrical pier. Subsequently, the flow characteristics around these structures are presented for different flow conditions. Mechanism of scouring phenomenon, the formation of vortex and its consequent effect is discussed for a straight channel. Effort was made towards estimation of scour depth around bridge piers under different flow conditions.

Keywords: bridge pier, computational fluid dynamics, multigrid, pier shape, scour

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Authors: Taleb L., Benarbia M., Brahmi M., Belmiloud H., Boukerche A.

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Introduction and purpose of the study: Cavum cancer in children and adolescents is rare and represents 8% of all nasopharyngeal cancers treated in our department. Our objective is to study its epidemiological, clinical, therapeutic, and evolutionary particularities. Material and methods: Retrospective study of 39 patients under 20 years old, treated for undifferentiated non-metastatic carcinoma of the nasopharynx at the Emir Abdelkader Cancer Center between 2014 and 2020. Results and statistical analysis: Median age was 14 years [7-19 years], with a sex ratio of 2.9. The median time to diagnosis was 5.6 months [1 to 14 months], the circumstances of the discovery of which were dominated by lymph node syndrome in 43.6% of cases (n=17) followed by a rhinological syndrome in 30.8% of cases (n=13). The tumor stage was T1 for two patients (5.1%), T2 for 8 (20.5%), T3 for 9 (23.1%), T4 for 20 (51.3%), N0 for 2 (5 .1%) N1 for 4 (10.3%), N2 for 28 (71.8%) and N3 for 5 (12.8%). All patients received induction chemotherapy followed by concomitant radiotherapy with cisplatin. The dose of irradiation delivered to the cavum and adenopathies was 66 Gy with fractionation of 2 Gy per session in 69.2% of cases (n=27) and 1.8 Gy in 30.8% of cases (n=12). With a median follow-up of 51 months (15 to 97 months), the locoregional, metastatic, specific, and overall relapse-free survival rates at five years were 91.1%, 73.5%, 66.1%, and 68.4, respectively. Conclusion: Chemotherapy and radiotherapy treatment of cavum cancer in children and adolescents has allowed excellent locoregional control despite the advanced stage of the disease. However, the frequency of metastatic relapses could justify the possible use of systemic maintenance treatment.

Keywords: cancer, nasopharynx, radiotherapy, chemotherapy, survival

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Authors: Agodo Mugenyi Herbert

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Background: A high prevalence of both HIV infection and mental disorders exists in Sub-Saharan Africa, however there is little integration of care for mental health disorders among HIV-infected individuals. The study aimed at determining the management of common mental disorders among HIV/AIDS clients attending Antiretroviral clinic in Hoima regional referral hospital. Significancy of the study: The information generated by this study would help mental health advocates, ministry of health, Civil society organizations in HIV programming to advocate for enhanced mental health care for PLWHA. The result will be used in policy development and lobbying for integration of mental health care in HIV/AIDS care. Methods: This study applied a cross sectional design. It involved data collection from clients with HIV/AIDS attending ART clinic in Hoima regional referral hospital at one specific point in time. It aimed at providing data on the entire population under study. Data was collected from Hoima Regional Referral Hospital at the ART clinic. Data analysis was performed using SPSS version 24. Results: 66 HIV/AIDS clients and 10 health workers in the ART clinic who participated fully completed the study. The overall prevalence of at least one form of mental disorder was 83%. Majority of the health care practitioner do not use pharmacological, psychological, and social interventions to manage such disorders. Conclusion: These results are suggestive of a significant proportion of the HIV-infected patients experiencing psychological difficulty for which they do not receive treatment Recommendations: Current care practices applied to patients with HIV/AIDS should be integrated more generally to include treatment services to identify and manage common mental disorders.

Keywords: common mental disorders, mental health, mental illness, and severe mental illness

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Authors: Xin Chen, Xinyong Li, Qidong Zhao, Dong Wang

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A new coupling system was constructed by combining photo-electrochemical cell with electro-fenton cell (PEC-EF). The electrode material in this system was derived from MnyFe₁₋yCo Prussian-Blue-Analog (PBA). Mn₀.₄Fe₀.₆Co₀.₆₇-N@C spin-coated on carbon paper behaved as the gas diffusion cathode and Mn₀.₄Fe₀.₆Co₀.₆₇O₂.₂ spin-coated on fluorine-tin oxide glass (FTO) as anode. The two separated cells could degrade Sulfamethoxazole (SMX) simultaneously and some coupling mechanisms by PEC and EF enhancing the degradation efficiency were investigated. The continuous on-site generation of H₂O₂ at cathode through an oxygen reduction reaction (ORR) was realized over rotating ring-disk electrode (RRDE). The electron transfer number (n) of the ORR with Mn₀.₄Fe₀.₆Co₀.₆₇-N@C was 2.5 in the selected potential and pH range. The photo-electrochemical properties of Mn₀.₄Fe₀.₆Co₀.₆₇O₂.₂ were systematically studied, which displayed good response towards visible light. The photoinduced electrons at anode can transfer to cathode for further use. Efficient photo-electro-catalytic performance was observed in degrading SMX. Almost 100% SMX removal was achieved in 120 min. This work not only provided a highly effective technique for antibiotic treatment but also revealed the synergic effect between PEC and EF.

Keywords: electro-fenton, photo-electrochemical, synergic effect, sulfamethoxazole

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Authors: Avadhoot Bhosale, Robin Davis P., Pradip Sarkar

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The seismic performance of buildings with irregular distribution of mass, stiffness and strength along the height may be significantly different from that of regular buildings with masonry infill. Masonry infilled reinforced concrete (RC) frames are very common structural forms used for multi-storey building construction. These structures are found to perform better in past earthquakes owing to additional strength, stiffness and energy dissipation in the infill walls. The seismic performance of a building depends on the variation of material, structural and geometrical properties. The sensitivity of these properties affects the seismic response of the building. The main objective of the sensitivity analysis is to found out the most sensitive parameter that affects the response of the building. This paper presents a sensitivity analysis by considering 5% and 95% probability value of random variable in the infills characteristics, trying to obtain a reasonable range of results representing a wide number of possible situations that can be met in practice by using pushover analysis. The results show that the strength-related variation values of concrete and masonry, with the exception of tensile strength of the concrete, have shown a significant effect on the structural performance and that this effect increases with the progress of damage condition for the concrete. The seismic risk assessments of the selected frames are expressed in terms of reliability index.

Keywords: fragility curve, sensitivity analysis, reliability index, RC frames

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Authors: Martin L. Zurita García, Erick O. Martínez Luque, Jessica Morales Perdomo, Yivy Martínez Duarte, Jorge Ari Noriega

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Colombia’s click beetles (Family Elateridae) are poorly documented in their diversity and taxonomy. There are listed 43 genera for Colombia but without a specific number of their species. No species of the genus Agriotes Eschscholtz (Elaterinae: Agriotini) have been recorded in Colombia. Currently, the subtribe Agriotina in the New World includes three genera: Agriotes, Bohartina Arias and Dalopius Eschscholtz. Historically, the genera Agriotes and Dalopius have had significant taxonomic problems due to their morphological resemblance. These similarities motivated several specialists to generate taxonomic movements such as synonyms and segregations of species in these genera on several occasions. To trying to solve these taxonomic problems, an author proposes some morphological characters present in the larvae, but mainly some genital characters of the females, such as the sclerotized plates of the bursa copulatrix. After examining material newly collected in Colombia, we found a click beetle having a unique combination of diagnostic characters that clearly separate it from any other genera of Agriotina. Hence, we describe and illustrate this click beetle under the name Raphaellus deusminutosi Zurita-García, Morales-Perdomo & Martínez-Luque n. gen. & n. sp., and we also compare this genus with the other New World genera of the subtribes Agriotina.

Keywords: click beetles, new genus, new species, elaterinae, raphaellus deusminutosi

Procedia PDF Downloads 90