Search results for: process issues
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 19064

Search results for: process issues

5444 Understanding the Role of Social Entrepreneurship in Building Mobility of a Service Transportation Models

Authors: Liam Fassam, Pouria Liravi, Jacquie Bridgman

Abstract:

Introduction: The way we travel is rapidly changing, car ownership and use are declining among young people and those residents in urban areas. Also, the increasing role and popularity of sharing economy companies like Uber highlight a movement towards consuming transportation solutions as a service [Mobility of a Service]. This research looks to bridge the knowledge gap that exists between city mobility, smart cities, sharing economy and social entrepreneurship business models. Understanding of this subject is crucial for smart city design, as access to affordable transport has been identified as a contributing factor to social isolation leading to issues around health and wellbeing. Methodology: To explore the current fit vis-a-vis transportation business models and social impact this research undertook a comparative analysis between a systematic literature review and a Delphi study. The systematic literature review was undertaken to gain an appreciation of the current academic thinking on ‘social entrepreneurship and smart city mobility’. The second phase of the research initiated a Delphi study across a group of 22 participants to review future opinion on ‘how social entrepreneurship can assist city mobility sharing models?’. The Delphi delivered an initial 220 results, which once cross-checked for duplication resulted in 130. These 130 answers were sent back to participants to score importance against a 5-point LIKERT scale, enabling a top 10 listing of areas for shared user transports in society to be gleaned. One further round (4) identified no change in the coefficient of variant thus no further rounds were required. Findings: Initial results of the literature review returned 1,021 journals using the search criteria ‘social entrepreneurship and smart city mobility’. Filtering allied to ‘peer review’, ‘date’, ‘region’ and ‘Chartered associated of business school’ ranking proffered a resultant journal list of 75. Of these, 58 focused on smart city design, 9 on social enterprise in cityscapes, 6 relating to smart city network design and 3 on social impact, with no journals purporting the need for social entrepreneurship to be allied to city mobility. The future inclusion factors from the Delphi expert panel indicated that smart cities needed to include shared economy models in their strategies. Furthermore, social isolation born by costs of infrastructure needed addressing through holistic A-political social enterprise models, and a better understanding of social benefit measurement is needed. Conclusion: In investigating the collaboration between key public transportation stakeholders, a theoretical model of social enterprise transportation models that positively impact upon the smart city needs of reduced transport poverty and social isolation was formed. As such, the research has identified how a revised business model of Mobility of a Service allied to a social entrepreneurship can deliver impactful measured social benefits associated to smart city design existent research.

Keywords: social enterprise, collaborative transportation, new models of ownership, transport social impact

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5443 Task Value and Research Culture of Southern Luzon State University

Authors: Antonio V. Romana, Rizaide A. Salayo, Maria Lavinia E. Fetalino

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This study assessed the subjective task value and research culture of SLSU faculty. It used the sequential explanatory mixed-method research design. For the quantitative phase, a questionnaire on the research culture and task value were used. While in the qualitative phase, the data was coded and thematized to interpret the focus group discussion outcome. Results showed that the dimensions of the subjective task value, intrinsic, got the highest rank while the utility value got the lowest. It is worth mentioning that all subjective task values were "Agreed." From the FGD, faculty members valued research and wanted to be involved in this undertaking. However, the limited number of faculty researchers, heavy teaching workload, inadequate information on the research process, lack of self-confidence, and low incentives received from research hindered their writing and engagement with research. Thus, a policy brief was developed. It is recommended that the institution may conduct a series of research seminar workshops for the faculty members, plan regular research idea exchange activities, and revisit the university's research thrust and agenda for faculties specialization and expertise alignment. In addition, the university may also lessen the workload and hire additional faculty members so that educators may focus on their research work. Finally, cash incentives may still be considered upon knowing that the faculty members have varied experiences in doing research tasks.

Keywords: task value, interest value, attainment value, utility value, research culture

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5442 Biochar Assisted Municipal Wastewater Treatment and Nutrient Recycling

Authors: A. Pokharel, A. Farooque, B. Acharya

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Pyrolysis can be used for energy production from waste biomass of agriculture and forestry. Biochar is the solid byproduct of pyrolysis and its cascading use can offset the cost of the process. A wide variety of research on biochar has highlighted its ability to absorb nutrients, metal and complex compounds; filter suspended solids; enhance microorganisms’ growth; retain water and nutrients as well as to increase carbon content of soil. In addition, sustainable biochar systems are an attractive approach for carbon sequestration and total waste management cycle. Commercially available biochar from Sigma Aldrich was studied for adsorption of nitrogen from effluent of municipal wastewater treatment plant. Adsorption isotherm and breakthrough curve were determined for the biochar. Similarly, biochar’s effects in aerobic as well as anaerobic bioreactors were also studied. In both cases, the biomass was increased in presence of biochar. The amount of gas produced for anaerobic digestion of fruit mix (apple and banana) was similar but the rate of production was significantly faster in biochar fed reactors. The cumulative goal of the study is to use biochar in various wastewater treatment units like aeration tank, secondary clarifier and tertiary nutrient recovery system as well as in anaerobic digestion of the sludge to optimize utilization and add value before being used as a soil amendment.

Keywords: biochar, nutrient recyling, wastewater treatment, soil amendment

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5441 Melancholia, Nostalgia: Bernardo Soares after Fernando Pessoa

Authors: Maria de Fátima Lambert

Abstract:

Bernardo Soares is one of Fernando Pessoa' several heteronyms (and "half-heteronyms"). Perhaps the one that brought together the majority of his qualities and characters of self-identity within the famous inner-persona-alter-diversity. The Book of Disquiet by Bernardo Soares was released in 1983, consisting of ontological remarks caught by an obsessive inquiring about self-existence. The book became a highly valuable substance when focusing upon the philosophical grounds of Pessoa's aesthetics. For sure, we cannot consider a single aesthetic, admitting that each heteronym has its own particular one, developed after different principles and convictions. Regarding Bernardo Soares, his thought arises from sequenced self-clues expressing peculiar existential doubtless presented as certainties -and vice-versa. His written self-search-images are reported, molding the painful awareness of existence through the discredited tolerance of any conclusive dialogue with others. Given the nature of Soares’ [maybe] unfinished writings, it is obvious that he headed far from his self-insurance-capsule: the office, bedroom, or even the walkscapes through Lisbon. The idea of travel/journey is one of the most relevant when recognizing his profound - although undercover - anguish as melancholy and nostalgia. In Bernardo Soares, Aesthetics is taken agonizingly, grounded upon discreet poetic phraseology and terms. His poetical awareness developed compulsive titles such "Aesthetics of Indifference", "Aesthetics of Discouragement". Soares' Aesthetics emerges directly from oneself, understanding art as inner acts and living experienced issues. Art is not freed from the intellectual expression of oneself emotions. The Disquiet Book is an existential nightmare nourished by everyday life, single written thoughts, balanced by melancholia, nostalgia, and distress. One might wonder if it was dreams that guided his fictional literary persona or the narrow facts of life itself. Along with his endless disquiet writing, Pessoa’s semi-heteronymous traveled without physically going anywhere. The complexity of inner existence is fulfilled by lonely mental walks and travels, as in two texts titled The Never Accomplished Journey. Although we also can consider other fragments, these are the deepest reflections about travelling. Let’s recall that Fernando Pessoa’s ortonyms writings -poems and essays- also addressed this issue from a philosophical perspective. We believe that this theme is one of the meaningful concepts for featuring the main principles of his aesthetics. As we know, Fernando Pessoa did not travel to foreign countries (or in Portugal), except for the journey, with his family, from Lisbon to South Africa (as a child) and, some years later, the return back to Lisbon. One may wonder why the poet never undertook other journeys. Maybe due to a disbelief in moving away from his comfort zone or due to the fear of becoming addicted to endless travels and the loss of his convenient self-closeness. In The Book of Disquiet, the poet shared his internal visions of the outer world but mainly visualizing his deepest enigmas and experiences -so strongly incorporated into reality and fiction.

Keywords: aesthetic principles, Bernardo Soares, Fernando Pessoa , melancholia, nostalgia, non-accomplished travel, The Book of Disquiet

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5440 A Method for Consensus Building between Teachers and Learners in a Value Co-Creative Learning Service

Authors: Ryota Sugino, Satoshi Mizoguchi, Koji Kimita, Keiichi Muramatsu, Tatsunori Matsui, Yoshiki Shimomura

Abstract:

Improving added value and productivity of services entails improving both value-in-exchange and value-in-use. Value-in-use is realized by value co-creation, where providers and receivers create value together. In higher education services, value-in-use comes from learners achieving learning outcomes (e.g., knowledge and skills) that are consistent with their learning goals. To enhance the learning outcomes of a learner, it is necessary to enhance and utilize the abilities of the teacher along with the abilities of the learner. To do this, however, the learner and the teacher need to build a consensus about their respective roles. Teachers need to provide effective learning content; learners need to choose the appropriate learning strategies by using the learning content through consensus building. This makes consensus building an important factor in value co-creation. However, methods to build a consensus about their respective roles may not be clearly established, making such consensus difficult. In this paper, we propose some strategies for consensus building between a teacher and a learner in value co-creation. We focus on a teacher and learner co-design and propose an analysis method to clarify a collaborative design process to realize value co-creation. We then analyze some counseling data obtained from a university class. This counseling aimed to build a consensus for value-in-use, learning outcomes, and learning strategies between the teacher and the learner.

Keywords: consensus building, value co-creation, higher education, learning service

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5439 Effect of Ultrasound on Carotenoids Extraction from Pepper and Process Optimization Using Response Surface Methodology (RSM)

Authors: Elham Mahdian, Reza Karazhian, Rahele Dehghan Tanha

Abstract:

Pepper (Capsicum annum L.) which belong to the family Solananceae, are known for their versatility as a vegetable crop and are consumed both as fresh vegetables or dehydrated for spices. Pepper is considered an excellent source of bioactive nutrients. Ascorbic acid, carotenoids and phenolic compounds are its main antioxidant constituents. Ultrasound assisted extraction is an inexpensive, simple and efficient alternative to conventional extraction techniques. The mechanism of action for ultrasound-assisted extraction are attributed to cavitations, mechanical forces and thermal impact, which result in disruption of cells walls, reduce particle size, and enhance mass transfer across cell membranes. In this study, response surface methodology was used to optimize experimental conditions for ultrasonic assisted extraction of carotenoid compounds from Chili peppers. Variables were included extraction temperatures at 3 levels (30, 40 and 50 °C), extraction times at 3 levels (10, 25 and 40 minutes) and power at 3 levels (30, 60 and 90 %). It was observed that ultrasound waves applied at temperature of 49°C, time of 10 minutes and power 89 % resulted to the highest carotenoids contents (lycopene and β-carotene), while the lowest value was recorded in the control. Thus, results showed that ultrasound waves have strong impact on extraction of carotenoids from pepper.

Keywords: carotenoids, optimization, pepper, response surface methodology

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5438 An Empirical Analysis of the Freight Forwarders’ Buying Behaviour: Implications for the Ocean Container Carriers

Authors: Peter Dzakah Fanam, Hong O. Nguyen, Stephen Cahoon

Abstract:

The objective of this study is to explore the buying behavior of the freight forwarders and to evaluate how their buying decision affects the ocean container carriers’ market share. This study analysed the buying decisions of the freight forwarders and validated the process of stages that the freight forwarders’ pass through before choosing an ocean container carrier. Factor analysis was applied to data collected from 105 freight forwarding companies to unveil the influential factors the freight forwarders’ consider important when selecting an ocean container carrier. This study did not only analysed the buying behaviour of the freight forwarders but also unveiled the influential factors affecting the competitiveness of the ocean container carriers in their market share maximisation. Furthermore, the study have made a methodological contribution that helps in better understanding of the critical factors influencing the selection of the ocean container carriers from the freight forwarders’ perspective. The implications of the freight forwarders’ buying behaviour is important to the ocean container carriers because it have severe effect on the market share of the ocean container carriers and the percentage of customers they control within the liner shipping sector. The findings of this study will help the ocean container carriers to formulate relevant marketing strategies in attracting the freight forwarders in purchasing the liner shipping service.

Keywords: ocean carrier, freight forwarder, buying behaviour, influential factors

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5437 ECE Teachers’ Evolving Pedagogical Documentation in MAFApp: ICT Integration for Collective Online Thinking in Early Childhood Education

Authors: Cynthia Adlerstein-Grimberg, Andrea Bralic-Echeverría

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An extensive and controversial research debate discusses pedagogical documentation (PD) within early childhood education (ECE) as integral to ECE teachers' professional development. The literature converges in acknowledging that ICT integration in PD can be fundamental for children's and teachers' collaborative learning by making their processes visible and open to reflection. Controversial issues about PD emerge around ICT integration and the use of multimedia applications and platforms, displacing the physical experience involved in this pedagogical practice. Authors argue that online platforms make PD become a passive device to demonstrate accountability and performance. Furthermore, ICT integration would make educators inform children and families of pedagogical processes, positioning them more as consumers instead of involving them in collective thinking and pedagogical decision-making. This article analyses how pedagogical documentation mediated by a multimedia application (MAFApp) allows for the positive strengthening of an ECE pedagogical online community that thinks collectively about learning environments. In doing so, the paper shows how ICT integration supports ECE teachers' collective online thinking, enabling them to move from the controversial version of online PD, where they only act as informers of children's learning and assume a voyeuristic perspective, towards a collective online thinking that builds professional development and supports pedagogical decision-making about learning environments. This article answers How ECE teachers' pedagogical documentation evolves with ICT integration using the MAFApp multimedia application in a national ECE online community. From a posthumanist stance, this paper draws on an 18-month collaborative ethnographic immersion in Chile's unique public ECE online PD community. It develops a unique case study of an online ECE pedagogical community mediated by a multimedia application called MAFApp. This ECE online community includes 32 Chilean public kindergartens, 45 ECE teachers, and 72 assistants, who produced 534 pedagogical documentation. Fieldwork included 35 in-depth interviews, 13 discussion groups, and the constant comparison method for the PD coding. Findings show ICT integration in PD builds collective online thinking that evolves through four moments of growing complexity: 1) teachernalism of built environments, 2) onlookerism of children's anecdotes in learning environments; 3) storytelling of children's place-making, and 4) empowering pedagogies for co-creating learning environments. ICT integration through the MAFApp multimedia application enabled ECE teachers to build collective online thinking, making pedagogies of place visible and engaging children in co-constructing learning environments. This online PD is a continuous professional learning space for ECE teachers, empowering pedagogies of place. In conclusion, ICT integration into PD progressively empowers pedagogies of place in Chilean public ECE. Strengthening collective online thinking using the MAFApp multimedia application sharply contrasts with some recent PD research findings. ICT integration to PD enabled strong collective online thinking. Doing so makes PD operate as a place of professional development, pedagogical reflective encounters, and experimentation while inhabiting their own learning environments with children.

Keywords: early childhood education, ICT integration, multimedia application, online collective thinking, pedagogical documentation, professional development

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5436 An Application of Meta-Modeling Methods for Surrogating Lateral Dynamics Simulation in Layout-Optimization for Electric Drivetrains

Authors: Christian Angerer, Markus Lienkamp

Abstract:

Electric vehicles offer a high variety of possible drivetrain topologies with up to 4 motors. Multi-motor-designs can have several advantages regarding traction, vehicle dynamics, safety and even efficiency. With a rising number of motors, the whole drivetrain becomes more complex. All permutations of gearings, drivetrain-layouts, motor-types and –sizes lead up in a very large solution space. Single elements of this solution space can be analyzed by simulation methods. In addition to longitudinal vehicle behavior, which most optimization-approaches are restricted to, also lateral dynamics are important for vehicle dynamics, stability and efficiency. In order to compete large solution spaces and to find an optimal result, genetic algorithm based optimization is state-of-the-art. As lateral dynamics simulation is way more CPU-intensive, optimization takes much more time than in case of longitudinal-only simulation. Therefore, this paper shows an approach how to create meta-models from a 14-degree of freedom vehicle model in order to enable a numerically efficient drivetrain-layout optimization process under consideration of lateral dynamics. Different meta-modelling approaches such as neural networks or DoE are implemented and comparatively discussed.

Keywords: driving dynamics, drivetrain layout, genetic optimization, meta-modeling, lateral dynamicx

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5435 Collaborative Online Learning for Lecturers

Authors: Lee Bih Ni, Emily Doreen Lee, Wee Hui Yean

Abstract:

This paper was prepared to see the perceptions of online lectures regarding collaborative learning, in terms of how lecturers view online collaborative learning in the higher learning institution. The purpose of this study was conducted to determine the perceptions of online lectures about collaborative learning, especially how lecturers see online collaborative learning in the university. Adult learning education enhance collaborative learning culture with the target of involving learners in the learning process to make teaching and learning more effective and open at the university. This will finally make students learning that will assist each other. It is also to cut down the pressure of loneliness and isolation might felt among adult learners. Their ways in collaborative online was also determined. In this paper, researchers collect data using questionnaires instruments. The collected data were analyzed and interpreted. By analyzing the data, researchers report the results according the proof taken from the respondents. Results from the study, it is not only dependent on the lecturer but also a student to shape a good collaborative learning practice. Rational concepts and pattern to achieve these targets be clear right from the beginning and may be good seen by a number of proposals submitted and include how the higher learning institution has trained with ongoing lectures online. Advantages of online collaborative learning show that lecturers should be trained effectively. Studies have seen that the lecturer aware of online collaborative learning. This positive attitude will encourage the higher learning institution to continue to give the knowledge and skills required.

Keywords: collaborative online learning, lecturers’ training, learning, online

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5434 Accessible Facilities in Home Environment for Elderly Family Members in Sri Lanka

Authors: M. A. N. Rasanjalee Perera

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The world is facing several problems due to increasing elderly population. In Sri Lanka, along with the complexity of the modern society and structural and functional changes of the family, “caring for elders” seems as an emerging social problem. This situation may intensify as the county is moving into a middle income society. Seeking higher education and related career opportunities, and urban living in modern housing are new trends, through which several problems are generated. Among many issues related with elders, “lack of accessible and appropriate facilities in their houses as well as public buildings” can be identified as a major problem. This study argues that welfare facilities provided for the elderly people, particularly in the home environment, in the country are not adequate. Modern housing features such as bathrooms, pantries, lobbies, and leisure areas etc. are questionable as to whether they match with elders’ physical and mental needs. Consequently, elders have to face domestic accidents and many other difficulties within their living environments. Records of hospitals in the country also proved this fact. Therefore, this study tries to identify how far modern houses are suited with elders’ needs. The study further questioned whether “aging” is a considerable matter when people are buying, planning and renovating houses. A randomly selected sample of 50 houses were observed and 50 persons were interviewed around the Maharagama urban area in Colombo district to obtain primary data, while relevant secondary data and information were used to have a depth analysis. The study clearly found that none of the houses included to the sample are considering elders’ needs in planning, renovating, or arranging the home. Instead, most of the families were giving priority to the rich and elegant appearance and modern facilities of the houses. Particularly, to the bathrooms, pantry, large setting areas, balcony, parking slots for two vehicles, ad parapet walls with roller-gates are the main concerns. A significant factor found here is that even though, many children of the aged are in middle age and reaching their older years at present, they do not plan their future living within a safe and comfortable home, despite that they are hoping to spent the latter part of their lives in the their current homes. This fact highlights that not only the other responsible parts of the society, but also those who are reaching their older ages are ignoring the problems of the aged. At the same time, it was found that more than 80% of old parents do not like to stay at their children’s homes as the living environments in such modern homes are not familiar or convenient for them. Due to this context, the aged in Sri Lanka may have to be alone in their own homes due to current trend of society of migrating to urban living in modern houses. At the same time, current urban families who live in modern houses may have to face adding accessible facilities in their home environment, as current modern housing facilities may not be appropriate them for a better life in their latter part of life.

Keywords: aging population, elderly care, home environment, housing facilities

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5433 A Study to Assess the Energy Saving Potential and Economic Analysis of an Agro Based Industry in Karnataka, India

Authors: Sangamesh G. Sakri, Akash N. Patil, Sadashivappa M. Kotli

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Agro based industries in India are considered as the micro, small and medium enterprises (MSME). In India, MSMEs contribute approximately 8 percent of the country’s GDP, 42 percent of the manufacturing output and 40 percent of exports. The toor dal (scientific name Cajanus cajan, commonly known as yellow gram, pigeon pea) is the second largest pulse crop in India accounting for about 20% of total pulse production. The toor dal milling industry in India is one of the major agro-processing industries in the country. Most of the dal mills are concentrated in pulse producing areas, which are spread all over the country. In Karnataka state, Gulbarga is a district, where toor dal is the main crop and is grown extensively. There are more than 500 dal mills in and around the Gulbarga district to process dal. However, the majority of these dal milling units use traditional methods of processing which are energy and capital intensive. There exists a huge energy saving potential in these mills. An energy audit is conducted on a dal mill in Gulbarga to understand the energy consumption pattern to assess the energy saving potential, and an economic analysis is conducted to identify energy conservation opportunities.

Keywords: conservation, demand side management, load curve, toor dal

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5432 Significant Factors to Motivate Small and Medium Enterprise (SME) Construction Firms in the Philippines to Implement ISO 9001:2008

Authors: Joseph Berlin P. Juanzon, Manuel M. Muhi

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Motivating SME-based construction firms to adopt different management systems is not a simple task, especially if they are not aware of the benefits that they will gain from the new process-based management system. The implementation of ISO 9001:2008, Quality Management System in the construction industry is an ongoing trend, more so in the Small and Medium Enterprise. However, the level of awareness and readiness of the construction industry in the Philippines is still low as compared to the neighboring countries in Asia and in the western countries where ISO 9001:2008 originated. The purpose of this research is to determine the significant factors that will motivate SME-based construction firms in the Philippines to implement ISO 9001:2008. A field study was conducted on SME based construction firms in the Philippines, wherein a total of 139 respondents out of the 613 SME-based construction firms in CALABARZON areas were surveyed. Results reveal that the three main factors that will motivate SME-based construction firms to implement ISO 9001:2008 are: - if required by their clients, - to qualify for bidding, and - to increase customer satisfaction. Therefore, based on the results and findings, a certification of ISO 9001:2008 from an accredited auditor shall be required by clients as a constituent in accrediting SME-based construction firms and to qualify for bidding.

Keywords: construction, ISO 9001:2008, quality management systems (QMS), small medium enterprise (SME)

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5431 Chemistry Teachers’ Perception of the Militating and Mitigating Factors Affecting the Use of Information and Communication Technology in Teaching and Learning of Chemistry

Authors: Peter I. I. Ikokwu

Abstract:

Recent developments in the world, both in the health and education sectors, have further popularized the importance of Information and Communication Technology (ICT). ICT is available for many purposes, including teaching and learning, and its use in education is believed to empower both teachers and students by making the educational process more effective and interactive. The study examined the perceptions of teachers on the factors affecting the use of ICT in the teaching and learning of chemistry and the mitigating factors. The study involved all the lecturers (herein referred to as teachers) in the Colleges of Education in South Eastern Nigeria. The survey design was employed. 35 teachers were selected by stratified random sampling from about 78 chemistry teachers in these Colleges. However, 34 questionnaires were recovered, comprising 13 males and 21 females. 3 research questions and 3 hypotheses guided the study. Results show that the teachers have a clear perception of the factors militating against the use of ICT in the teaching and learning of chemistry, with a pooled mean of 2.96. But there was no significant difference in the perceptions of male and female teachers. Also, they identified the mitigating factors highlighted with no significant difference between the perceptions of the males and females with pooled means of 3.23 and 3.11, respectively. In all, it is noteworthy that lack of funds, irregular and inadequate power supply, and inadequate time in the school timetable was among the militating factors. Recommendations were made for the consideration of the government, the teachers, and the Institutions.

Keywords: chemistry, teachers, perception, ICT, learning

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5430 Design of a Customized Freshly-Made Fruit Salad and Juices Vending Machine

Authors: María Laura Guevara Campos

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The increasing number of vending machines makes it easy for people to find them more frequently in stores, universities, workplaces, and even hospitals. These machines usually offer products with high contents of sugar and fat, which, if consumed regularly, can result in serious health threats, as overweight and obesity. Additionally, the energy consumption of these machines tends to be high, which has an impact on the environment as well. In order to promote the consumption of healthy food, a vending machine was designed to give the customer the opportunity to choose between a customized fruit salad and a customized fruit juice, both of them prepared instantly with the ingredients selected by the customer. The main parameters considered to design the machine were: the storage of the preferred fruits in a salad and/or in a juice according to a survey, the size of the machine, the use of ecologic recipients, and the overall energy consumption. The methodology used for the design was the one proposed by the German Association of Engineers for mechatronics systems, which breaks the design process in several stages, from the elaboration of a list of requirements through the establishment of the working principles and the design concepts to the final design of the machine, which was done in a 3D modelling software. Finally, with the design of this machine, the aim is to contribute to the development and implementation of healthier vending machines that offer freshly-made products, which is not being widely attended at present.

Keywords: design, design methodology, mechatronics systems, vending machines

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5429 Effects of Bipolar Plate Coating Layer on Performance Degradation of High-Temperature Proton Exchange Membrane Fuel Cell

Authors: Chen-Yu Chen, Ping-Hsueh We, Wei-Mon Yan

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Over the past few centuries, human requirements for energy have been met by burning fossil fuels. However, exploiting this resource has led to global warming and innumerable environmental issues. Thus, finding alternative solutions to the growing demands for energy has recently been driving the development of low-carbon and even zero-carbon energy sources. Wind power and solar energy are good options but they have the problem of unstable power output due to unpredictable weather conditions. To overcome this problem, a reliable and efficient energy storage sub-system is required in future distributed-power systems. Among all kinds of energy storage technologies, the fuel cell system with hydrogen storage is a promising option because it is suitable for large-scale and long-term energy storage. The high-temperature proton exchange membrane fuel cell (HT-PEMFC) with metallic bipolar plates is a promising fuel cell system because an HT-PEMFC can tolerate a higher CO concentration and the utilization of metallic bipolar plates can reduce the cost of the fuel cell stack. However, the operating life of metallic bipolar plates is a critical issue because of the corrosion phenomenon. As a result, in this work, we try to apply different coating layer on the metal surface and to investigate the protection performance of the coating layers. The tested bipolar plates include uncoated SS304 bipolar plates, titanium nitride (TiN) coated SS304 bipolar plates and chromium nitride (CrN) coated SS304 bipolar plates. The results show that the TiN coated SS304 bipolar plate has the lowest contact resistance and through-plane resistance and has the best cell performance and operating life among all tested bipolar plates. The long-term in-situ fuel cell tests show that the HT-PEMFC with TiN coated SS304 bipolar plates has the lowest performance decay rate. The second lowest is CrN coated SS304 bipolar plate. The uncoated SS304 bipolar plate has the worst performance decay rate. The performance decay rates with TiN coated SS304, CrN coated SS304 and uncoated SS304 bipolar plates are 5.324×10⁻³ % h⁻¹, 4.513×10⁻² % h⁻¹ and 7.870×10⁻² % h⁻¹, respectively. In addition, the EIS results indicate that the uncoated SS304 bipolar plate has the highest growth rate of ohmic resistance. However, the ohmic resistance with the TiN coated SS304 bipolar plates only increases slightly with time. The growth rate of ohmic resistances with TiN coated SS304, CrN coated SS304 and SS304 bipolar plates are 2.85×10⁻³ h⁻¹, 3.56×10⁻³ h⁻¹, and 4.33×10⁻³ h⁻¹, respectively. On the other hand, the charge transfer resistances with these three bipolar plates all increase with time, but the growth rates are all similar. In addition, the effective catalyst surface areas with all bipolar plates do not change significantly with time. Thus, it is inferred that the major reason for the performance degradation is the elevated ohmic resistance with time, which is associated with the corrosion and oxidation phenomena on the surface of the stainless steel bipolar plates.

Keywords: coating layer, high-temperature proton exchange membrane fuel cell, metallic bipolar plate, performance degradation

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5428 Psychophysiological Synchronization between the Manager and the Subordinate during a Performance Review Discussion

Authors: Mikko Salminen, Niklas Ravaja

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Previous studies have shown that emotional intelligence (EI) has an important role in leadership and social interaction. On the other hand, physiological synchronization between two interacting participants has been related to, for example, intensity of the interaction, and interestingly also to empathy. It is suggested that the amount of covariation in physiological signals between the two interacting persons would also be related to how the discussion is perceived subjectively. To study the interrelations between physiological synchronization, emotional intelligence, and subjective perception of the interaction, performance review discussions between real manager – subordinate dyads were studied using psychophysiological measurements and self-reports. The participants consisted of 40 managers, of which 24 were female, and 78 of their subordinates, of which 45 were female. The participants worked in various fields, for example banking, education, and engineering. The managers had a normal performance review discussion with two subordinates, except two managers who, due to scheduling issues, had discussion with only one subordinate. The managers were on average 44.5 years old, and the subordinates on average 45.5 years old. Written consent, in accordance with the Declaration of Helsinki, was obtained from all the participants. After the discussion, the participants filled a questionnaire assessing their emotions during the discussion. This included a self-assessment manikin (SAM) scale for the emotional valence during the discussion, with a 9-point graphical scale representing a manikin whose facial expressions ranged from smiling and happy to frowning and unhappy. In addition, the managers filled EI360, a 37-item self-report trait emotional intelligence questionnaire. The psychophysiological activity of the participants was recorded using two Varioport-B portable recording devices. Cardiac activity (ECG, electrocardiogram) was measured with two electrodes placed on the torso. Inter-beat interval (IBI, time between two successive heart beats) was calculated from the ECG signals. The facial muscle activation (EMG, electromyography) was recorded on three sites of the left side of the face: zygomaticus major (cheek muscle), orbicularis oculi (periocular muscle), and corrugator supercilii (frowning muscle). The facial-EMG signals were rectified and smoothed, and cross-coherences were calculated between members of each dyad, for all the three EMG signals, for the baseline and discussion periods. The values were natural-log transformed to normalize the distributions. Higher cross-coherence during the discussion between the manager’s and the subordinate’s zygomatic muscles was related to more positive valence self-reported emotions, F(1; 66,137) = 7,051; p=0,01. Thus, synchronized cheek muscle activation, either due to synchronous smiling or talking, was related to more positive perception of the discussion. In addition, higher IBI synchronization between the manager and the subordinate during the discussion was related to the manager’s higher self-reported emotional intelligence, F(1; 27,981)=4,58; p=0,041. That is, the EI was related to synchronous cardiac activity and possibly to similar physiological arousal levels. The results imply that the psychophysiological synchronization could be a potentially useful index in the study of social interaction and a valuable tool in the coaching of leadership skills in organizational contexts.

Keywords: emotional intelligence, leadership, psychophysiology, social interaction, synchronization

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5427 IPO Valuation and Profitability Expectations: Evidence from the Italian Exchange

Authors: Matteo Bonaventura, Giancarlo Giudici

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This paper analyses the valuation process of companies listed on the Italian Exchange in the period 2000-2009 at their Initial Public Offering (IPO). One the most common valuation techniques declared in the IPO prospectus to determine the offer price is the Discounted Cash Flow (DCF) method. We develop a ‘reverse engineering’ model to discover the short term profitability implied in the offer prices. We show that there is a significant optimistic bias in the estimation of future profitability compared to ex-post actual realization and the mean forecast error is substantially large. Yet we show that such error characterizes also the estimations carried out by analysts evaluating non-IPO companies. The forecast error is larger the faster has been the recent growth of the company, the higher is the leverage of the IPO firm, the more companies issued equity on the market. IPO companies generally exhibit better operating performance before the listing, with respect to comparable listed companies, while after the flotation they do not perform significantly different in term of return on invested capital. Pre-IPO book building activity plays a significant role in partially reducing the forecast error and revising expectations, while the market price of the first day of trading does not contain information for further reducing forecast errors.

Keywords: initial public offerings, DCF, book building, post-IPO profitability drop

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5426 The Analysis of the Role of Handicrafts in Consolidating Iran National Identity

Authors: Nadia Pourabbas Tahvildari

Abstract:

National identity is formed in the process of time and in the community while influenced by the historical events. The country which has a more coherent national and historical identity would be successful as well as strengthening solidarity and social cohesion. Among the international community where the various likes challenge the subject of identity, taking into consideration the components which using identity seems to be very critical. Handicrafts as reflecting the historical and cultural characteristics of the product location can be used as an important component in order to introduce the culture and identity to be evaluated. As one of the most durable crafts for man, handicrafts have played a continuous role in sustaining human culture. Today without the presence of handicrafts, restoration of culture and national identity and religious beliefs of the past clans and people, is not only difficult but is even impossible also. Due to its brilliant historical experience and having rich culture and civilization, Iran has accomplished to the high competence in the field of traditional arts and handicrafts. This article is a scientific approach which by using descriptive – analytic method based on library studies tried to address the issue of handicrafts looking to examine the position of the industry to consolidate the national identity. Studies indicate that Iran as one of the original human habitats in the field of handicrafts has adequate enrichment and in case there will be an appropriate planning and investment away from oil-based industry, it would be beneficent. Furthermore, the quality and variety of handicrafts can be used as an essential yardstick for the consolidation of Iran national identity in the age of globalization.

Keywords: handicrafts, Iran national identity, globalization, cultural heritage

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5425 A Systematic Review of Forest School for Early Childhood Education in China: Lessons Learned from European Studies from a Perspective of Ecological System

Authors: Xiaoying Zhang

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Forest school – an outdoor educational experience that is undertaken in an outdoor environment with trees – becomes an emerging field of early childhood education recently. In China, the benefits of natural outdoor education to children and young people’s wellness have raised attention. Although different types of outdoor-based activities have been involved in some pre-school of China, few study and practice have been conducted in terms of the notion of forest school. To comprehend the impact of forest school for children and young people, this study aims to systematically review articles on the topic of forest school in preschool education from an ecological perspective, i.e. from individual level (e.g., behavior and mental health) to microsystem level (e.g., the relationship between teachers and children) to ecosystem level. Based on PRISMA framework flow, using the key words of “Forest School” and “Early Childhood Education” for searching in Web-of-science database, a total of 33 articles were identified. Sample participants of 13 studies were not preschool children, five studies were not on forest school theme, and two literature review articles were excluded for further analysis. Finally, 13 articles were eligible for thematic analysis. According to Bronfenbrenner's ecological systems theory, there are some fingdings, on the individual level, current forest school studies are concerned about the children behavioral experience in forest school, how these experience may relate to their achievement or to develop children’s wellbeing/wellness, and how this type of learning experience may enhance children’s self-awareness on risk and safety issues. On the microsystem/mesosystem level, this review indicated that pedagogical development for forest school, risk perception from teachers and parents, social development between peers, and adult’s role in the participation of forest school were concerned, explored and discussed most frequently. On the macrosystem, the conceptualization of forest school is the key theme. Different forms of presentation in various countries with diverse cultures could provide various models of forest school education. However, there was no study investigating forest school on an ecosystem level. As for the potential benefits of physical health and mental wellness that results from forest school, it informs us to reflect the system of preschool education from the ecological perspective for Chinese children. For instance, most Chinese kindergartens ignored the significance of natural outdoor activities for children. Preschool education in China is strongly oriented by primary school system, which means pre-school children are expected to be trained as primary school students to do different subjects, such as math. Hardly any kindergarteners provide the opportunities for children and young people to take risks in a natural environment like forest school does. However, merely copying forest school model for a Chinese preschool education system will be less effective. This review of different level concerns could inform us that the localization the idea of forest school to adapt to a Chinese political, educational and cultural background. More detailed results and profound discussions will be presented in the full paper.

Keywords: early childhood education, ecological system, education development prospects in China, forest school

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5424 Evaluation of Chromium Fortified-Parboiled Rice Coated with Herbal Extracts: Resistant Starch, and Glycemic Index

Authors: Wisnu Adi Yulianto, Chatarina Lilis Suryani, Mamilisti Susiati, Hendy Indra Permana

Abstract:

Parboiled rice was developed to produce rice that has low glycemic index, especially for diabetics. Yet, parboiled rice is not enough because diabetics also lack of chromium. The sign of chromium (Cr) deficiency in diabetics is impaired glucose tolerance. Cr fortification was done for increasing Cr content in rice. Naturally-occurring compounds that have been proven to improve insulin sensitivity include Cr and polyphenol found in cinnamon, pandan and bay leaf. This research aimed to evaluate content of resistant starch and glycemic index of Cr - fortified - parboiled rice (Cr-PR) coated with herbal extracts. Variety of unhulled rice and forticant used in the experiment were Ciherang and CrCl3, respectively. Three herbal extracts used were cinnamon, pandan and bay leaf. Each concentration of herbal extracts in the amount of 3%, 6%, and 9% were added in the coating substance to coat Cr-PR. Resistant starch (RS) content was determined by enzymatic process through glucooxydase method. Testing of the GI was conducted on 18 non-diabetic volunteers. RS content of Cr-PR coated with herbal extracts ranged between 8.27 – 8.84 % (dry weight). Cr-PR coated with all herbal extracts of 3% concentration had higher RS content than the ones with herbal extracts of 6% and 9% concentration (P <0.05). Value of the rice GI ranged 29 - 40. The lowest GI (29-30) was attained by the rice coated with enrichment of 6-9% cinnamon extract.

Keywords: coating, Cr-fortified-parboiled rice, glycemic index, herbal extracts, resistant starch

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5423 Making Haste Slowly: South Africa's Transition from a Medical to a Social Model regarding Persons with Disabilities

Authors: Leoni Van Der Merwe

Abstract:

Historically, in South Africa, disability has been viewed as a dilemma of the individual. The discourse surrounding the definition of disability and applicable theories are as fluid as the differing needs of persons with disabilities within society. In 1997, the Office of the Deputy President published the White Paper on the Integrated National Disability Strategy (WPINDS) which sought to integrate disability issues in all governmental development strategies, planning and programs as well as to solidify the South African government’s stance that disability was to be considered according to the social model and not the, previously utilized, medical model of disability. The models of disability are conceptual frameworks for understanding disability and can provide some insight into why certain attitudes exist and how they are reinforced in society. Although the WPINDS was regarded as a critical milestone in the history of the disability rights struggle in South Africa; it has taken approximately twenty years for the publication of a similar document taking into account South Africa’s changing social, economic, political and technological dispensation. December 2015 marked the approval of the White Paper on the Rights of Persons with Disabilities (WPRPD) which seeks to update the WPINDS, integrate principles contained in international law instruments and endorse a mainstreaming trajectory for realizing the rights of persons with disabilities. While the WPINDS and the WPRPD were published two decades apart, both documents contain an emphasis on a transition from the medical model to the social model. Whereas, the medical model presupposes that disability is mainly a health and welfare matter and is focused on an individualistic and dependency-based approach; the social model requires a paradigm shift in the manner in which disability is constructed so as to highlight the shortcomings of society in respect of disability and to bring to the fore the capabilities of persons with disabilities. The social model has led to unmatched success in changing the perceptions surrounding disability. This article seeks to investigate the progress made in the implementation of the social model in South Africa by taking into account the effect of the diverse political and cultural landscape in promoting the historically entrenched medical model and the rise of disability activism prior to the new democratic dispensation as well as legislation, case law, policy documents and barriers in respect of persons with disabilities that are pervasive in South African society. The research paper will conclude that although numerous interventions have been identified and implemented to promote the consideration of disability within a social construct in South Africa, such interventions require increased national and international collaboration, resources and pace to ensure that the efforts made lead to sustainable results. For persons with disabilities, what remains to be seen is whether the proliferation of activism by interest groups, social awareness as well as the development of policy documents, legislation and case law will serve as the impetus to dissipate the view that disability is burden to be carried solely on the shoulders of the person with the disability.

Keywords: disability, medical model, social model, societal barriers, South Africa

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5422 3D Scanning Documentation and X-Ray Radiography Examination for Ancient Egyptian Canopic Jar

Authors: Abdelrahman Mohamed Abdelrahman

Abstract:

Canopic jars are one of the vessels of funerary nature used by the ancient Egyptian in mummification process that were used to save the viscera of the mummified body after being extracted from the body and treated. Canopic jars are made of several types of materials like Limestone, Alabaster, and Pottery. The studied canopic jar dates back to Late period, located in the Grand Egyptian Museum (GEM), Giza, Egypt. This jar carved from limestone with carved hieroglyphic inscriptions, and it filled and closed by mortar from inside. Some aspects of damage appeared in the jar, such as dust, dirts, classification, wide crack, weakness of limestone. In this study, we used documentation and investigation modern techniques to document and examine the jar. 3D scanning and X-ray Radiography imaging used in applied study. X-ray imaging showed that the mortar was placed at a time when the jar contained probably viscera where the mortar appeared that not reach up to the base of the inner jar. Through the three-dimensional photography, the jar was documented, and we have 3D model of the jar, and now we have the ability through the computer to see any part of the jar in all its details. After that, conservation procedures have been applied with high accuracy to conserve the jar, including mechanical, wet, and chemical cleaning, filling wide crack in the body of the jar using mortar consisting of calcium carbonate powder mixing with primal E330 S, and consolidation, so the limestone became strong after using paraloid B72 2% concentrate as a consolidate material.

Keywords: vessel, limestone, canopic jar, mortar, 3D scanning, X-ray radiography

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5421 The Application of Cellulose-Based Halloysite-Carbon Adsorbent to Remove Chloroxylenol from Water

Authors: Laura Frydel

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Chloroxylenol is a common ingredient in disinfectants. Due to the use of this compound in large amounts, it is more and more often detected in rivers, sewage, and also in human body fluids. In recent years, there have been concerns about the potentially harmful effects of chloroxylenol on human health and the environment. This paper presents the synthesis, a brief characterization and the use of a halloysite-carbon adsorbent for the removal of chloroxylenol from water. The template in the halloysite-carbon adsorbent was acid treated bleached halloysite, and the carbon precursor was cellulose dissolved in zinc (II) chloride, which was dissolved in 37% hydrochloric acid. The FTIR spectra before and after the adsorption process allowed to determine the presence of functional groups, bonds in the halloysite-carbon composite, and the binding mechanism of the adsorbent and adsorbate. The morphology of the bleached halloysite sample and the sample of the halloysite-carbon adsorbent were characterized by scanning electron microscopy (SEM) with surface analysis by X-ray dispersion spectrometry (EDS). The specific surface area, total pore volume and mesopore and micropore volume were determined using the ASAP 2020 volumetric adsorption analyzer. Total carbon and total organic carbon were determined for the halloysite-carbon adsorbent. The halloysite-carbon adsorbent was used to remove chloroxylenol from water. The degree of removal of chloroxylenol from water using the halloysite-carbon adsorbent was about 90%. Adsorption studies show that the halloysite-carbon composite can be used as an effective adsorbent for removing chloroxylenol from water.

Keywords: adsorption, cellulose, chloroxylenol, halloysite

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5420 Increased Nitrogen Removal in Cold Deammonification Biofilm Reactor (9-15°C) by Smooth Temperature Decreasing

Authors: Ivar Zekker, Ergo Rikmann, Anni Mandel, Markus Raudkivi, Kristel Kroon, Liis Loorits, Andrus Seiman, Hannu Fritze, Priit Vabamäe, Toomas Tenno, Taavo Tenno

Abstract:

The anaerobic ammonium oxidation (anammox) and nitritation-anammox (deammonification) processes are widely used for N-rich wastewater treatment nowadays. A deammonification moving bed biofilm reactor (MBBR) with a high maximum total nitrogen removal rate (TNRR) of 1.5 g N m-2 d-1 was started up and similarly high TNRR was sustained at low temperature of 15°C. During biofilm cultivation, temperature in MBBR was lowered by 0.5° C week-1 sustaining the high TNRR. To study the short-term effect of temperature on the TNRR, a series of batch-scale experiments performed showed sufficient TNRRs even at 9-15° C (4.3-5.4 mg N L-1 h-1, respectively). After biomass was adapted to lower temperature (15°C), the TNRR increase at lower temperature (15°C) was relatively higher (15-20%) than with biomass adapted to higher temperatures (17-18°C). Anammox qPCR showed increase of Candidatus Brocadia quantities from 5×103 to 1×107 anammox gene copies g-1 TSS despite temperature lowered to 15°C. Modeling confirmed causes of stable and unstable periods in the reactor and in batch test high Arrhenius constant of 29.7 kJ mol-1 of the process as high as at 100 mg NO2--N L-1 were determined. 

Keywords: deammonification, reject water, intermittent aeration, nitrite inhibition

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5419 The Hotel Logging Behavior and Factors of Tourists in Bankontee District, Samut Songkhram Province, Thailand

Authors: Aticha Kwaengsopha

Abstract:

The purpose of this research was to study the behaviour and related factors that tourists utilized for making decisions to choose their accommodations at a tourist destination, Bangkontee district, Samut Songkhran Province, Thailand. The independent variables included gender, age, income, occupation, and region, while the three important dependent variables included selection behaviour, factors related selection process, and satisfaction of the accommodation service. A total of 400 Thai and international tourists were interviewed at tourist destination of Bangkontee. A questionnaire was used as the tool for collecting data. Descriptive statistics in this research included percentage, mean, and standard deviation. The findings revealed that the majority of respondents were single, female, and with the age between 23-30 years old. Most of the international tourists were from Asia and planned to stay in Thailand about 1-6 days. In addition, the majority of tourists preferred to travel in small groups of 3 persons. The majority of respondents used internet and word of mouth as the main tool to search for information. The majority of respondents spent most of their budget on food & drink, accommodation, and travelling. Even though the majority of tourists were satisfied with the quality of accommodation, the price range of accommodation, and the image of accommodation and the facilities of the accommodation, they indicated that they were not likely to re-visit Thailand in the near future.

Keywords: behaviour, decision factors, tourists, media engineering

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5418 Particle Size Analysis of Itagunmodi Southwestern Nigeria Alluvial Gold Ore Sample by Gaudin Schumann Method

Authors: Olaniyi Awe, Adelana R. Adetunji, Abraham Adeleke

Abstract:

Mining of alluvial gold ore by artisanal miners has been going on for decades at Itagunmodi, Southwestern Nigeria. In order to optimize the traditional panning gravity separation method commonly used in the area, a mineral particle size analysis study is critical. This study analyzed alluvial gold ore samples collected at identified five different locations in the area with a view to determine the ore particle size distributions. 500g measured of as-received alluvial gold ore sample was introduced into the uppermost sieve of an electrical sieve shaker consisting of sieves arranged in the order of decreasing nominal apertures of 5600μm, 3350μm, 2800μm, 355μm, 250μm, 125μm and 90μm, and operated for 20 minutes. The amount of material retained on each sieve was measured and tabulated for analysis. A screen analysis graph using the Gaudin Schuman method was drawn for each of the screen tests on the alluvial samples. The study showed that the percentages of fine particle size -125+90 μm fraction were 45.00%, 36.00%, 39.60%, 43.00% and 36.80% for the selected samples. These primary ore characteristic results provide reference data for the alluvial gold ore processing method selection, process performance measurement and optimization.

Keywords: alluvial gold ore, sieve shaker, particle size, Gaudin Schumann

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5417 Enhancing the Rollability of Cu-Ge-Ni Alloy through Heat Treatment Methods

Authors: Morteza Hadi

Abstract:

This research investigates the potential enhancement of the rollability of Cu-Ge-Ni alloy through the mitigation of microstructural and compositional inhomogeneities via two distinct heat treatment methods: homogenization and solution treatment. To achieve this objective, the alloy with the desired composition was fabricated using a vacuum arc remelting furnace (VAR), followed by sample preparation for microstructural, compositional, and heat treatment analyses at varying temperatures and durations. Characterization was conducted employing optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers hardness testing. The results obtained indicate that a minimum duration of 10 hours is necessary for adequate homogenization of the alloy at 750°C. This heat treatment effectively removes coarse dendrites from the casting microstructure and significantly reduces elemental separations. However, despite these improvements, the presence of a second phase with markedly different hardness from the matrix results in poor rolling ability for the alloy. The optimal time for solution treatment at various temperatures was determined, with the most effective cycle identified as 750°C for 2 hours, followed by rapid quenching in water. This process induces the formation of a single-phase microstructure and complete elimination of the second  phase, as confirmed by X-ray diffraction analysis. Results demonstrate a reduction in hardness by 30 Vickers, and the elimination of microstructural unevenness enables successful thickness reduction by up to 50% through rolling without encountering cracking.

Keywords: Cu-Ge-Ni alloy, homogenization. solution treatment, rollability

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5416 Assessment of Hygroscopic Characteristics of Hevea brasiliensis Wood

Authors: John Tosin Aladejana

Abstract:

Wood behave differently under different environmental conditions. The knowledge of the hygroscopic nature of wood becomes a key factor in selecting wood for use and required treatment. This study assessed the hygroscopic behaviour of Hevea brasiliensis (Rubber) wood. Void volume, volumetric swelling in the tangential, radial and longitudinal directions and volumetric shrinkage were used to assess the response of the wood when loosing or taking up moisture. Hevea brasiliensis wood samples cut into 20 × 20 × 60 mm taken longitudinally and transversely were used for the study and dried in the oven at 103 ± 2⁰C. The mean values for moisture content in green Hevea brasiliensis wood were 49.74 %, 51.14 % and 54.36 % for top, middle and bottom portion respectively while 51.77 %, 50.02 % and 53.45 % were recorded for outer, middle and inner portions respectively for the tree. The values obtained for volumetric shrinkage and swelling indicated that shrinkage and swelling were higher at the top part of H. brasiliensis. It was also observed that the longitudinal shrinkage was negligible while tangential direction showed the highest shrinkage among the wood direction. The values of the void volume obtained were 43.0 %, 39.0 % and 38.0 % at the top, middle and bottom respectively. The result obtained showed clarification on the wood density of hevea brasiliensis based on the position and portion of the wood species and the variation in moisture content, void volume, volumetric shrinkage and swelling were also revealed. This will provide information in the process of drying hevea brasiliensis wood to ensure better wood quality devoid of defects.

Keywords: moisture content, shrinkage, swelling, void volume

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5415 Doping Density Effects on Minority Carrier Lifetime in Bulk GaAs by Means of Photothermal Deflection Technique

Authors: Soufiene Ilahi

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Photothermal effect occurs when absorbed light energy that generate a thermal wave that propagate into the sample and surrounding media. Subsequently, the propagation of the vibration of phonons or electrons causes heat transfer. In fact, heat energy is provided by non-radiative recombination process that occurs in semiconductors sample. Three heats sources are identified: surface recombination, bulk recombination and carrier thermalisation. In the last few years, Photothermal Deflection Technique PTD is a nondestructive and accurate technique that prove t ability for electronics properties investigation. In this paper, we have studied the influence of doping on minority carrier lifetime, i.e, nonradiative lifetime, surface and diffusion coefficient. In fact, we have measured the photothermal signal of two sample of GaAs doped with C et Cr.In other hand , we have developed a theoretical model that takes into account of thermal and electronics diffusion equations .In order to extract electronics parameters of GaAs samples, we have fitted the theoretical signal of PTD to the experimental ones. As a results, we have found that nonradiative lifetime is around of 4,3 x 10-8 (±11,24%) and 5 x 10-8 (±14,32%) respectively for GaAs : Si doped and Cr doped. Accordingly, the diffusion coefficient is equal 4,6 *10-4 (± 3,2%) and 5* 10-4 (± 0,14%) foe the Cr, C and Si doped GaAs respectively.

Keywords: nonradiative lifetime, mobility of minority carrier, diffusion length, surface and interface recombination in GaAs

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