Search results for: temporary competitive advantage

Authors: Linda D. F. Bambara, Marie Sawadogo

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Jatropha curcas (jatropha) is the plant that has been the most studied for biofuel production in West Africa. There exist however other plants such as Balanites aegyptiaca (balanites) that have been targeted as a potential feedstock for biofuel production. This biomass could be an alternative feedstock for the production of straight vegetable oil (SVO) at costs lower than jatropha-based SVO production costs. This study aims firstly to determine, through an MILP model, the optimal organization that minimizes the costs of the oilseeds supply of two biomass conversion units (BCU) exploiting respectively jatropha seeds and the balanitès seeds. Secondly, the study aims to carry out a comparative study of these costs obtained for each BCU. The model was then implemented on two theoretical cases studies built on the basis of the common practices in Burkina Faso and two scenarios were carried out for each case study. In Scenario 1, 3 pre-processing locations ("at the harvesting area", "at the gathering points", "at the BCU") are possible. In scenario 2, only one location ("at the BCU") is possible. For each biomass, the system studied is the upstream supply chain (harvesting, transport and pre-processing (drying, dehulling, depulping)), including cultivation (for jatropha). The model optimizes the area of land to be exploited based on the productivity of the studied plants and material losses that may occur during the harvesting and the supply of the BCU. It then defines the configuration of the logistics network allowing an optimal supply of the BCU taking into account the most common means of transport in West African rural areas. For the two scenarios, the results of the implementation showed that the total area exploited for balanites (1807 ha) is 4.7 times greater than the total area exploited for Jatropha (381 ha). In both case studies, the location of pre-processing “at the harvesting area” was always chosen for scenario1. As the balanites trees were not planted and because the first harvest of the jatropha seeds took place 4 years after planting, the cost price of the seeds at the BCU without the pre-processing costs was about 430 XOF/kg. This cost is 3 times higher than the balanites's one, which is 140 XOF/kg. After the first year of harvest, i.e. 5 years after planting, and assuming that the yield remains constant, the same cost price is about 200 XOF/kg for Jatropha. This cost is still 1.4 times greater than the balanites's one. The transport cost of the balanites seeds is about 120 XOF/kg. This cost is similar for the jatropha seeds. However, when the pre-processing is located at the BCU, i.e. for scenario2, the transport costs of the balanites seeds is 1200 XOF/kg. These costs are 6 times greater than the transport costs of jatropha which is 200 XOF/kg. These results show that the cost price of the balanites seeds at the BCU can be competitive compared to the jatropha's one if the pre-processing is located at the harvesting area.

Keywords: Balanites aegyptiaca, biomass conversion, Jatropha curcas, optimization, post-harvest operations

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Authors: Xiaobo Rui, Zhoumo Zeng, Yibo Li

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A novel tri-cantilever energy harvester with magnetic oscillator was presented, which could convert the ambient vibration into electrical energy to power the low-power devices such as wireless sensor networks. The most common way to harvest vibration energy is based on the use of linear resonant devices such as cantilever beam, since this structure creates the highest strain for a given force. The highest efficiency will be achieved when the resonance frequency of the harvester matches the vibration frequency. The limitation of the structure is the narrow effective bandwidth. To overcome this limitation, this article introduces a broadband tri-cantilever harvester with nonlinear stiffness. This energy harvester typically consists of three thin cantilever beams vertically arranged with Neodymium Magnets ( NdFeB)magnetics at its free end and a fixed base at the other end. The three cantilevers have different resonant frequencies by designed in different thicknesses. It is obviously that a similar advantage of multiple resonant frequencies as piezoelectric cantilevers array structure is built. To achieve broadband energy harvesting, magnetic interaction is used to introduce the nonlinear system stiffness to tune the resonant frequency to match the excitation. Since the three cantilever tips are all free and the magnetic force is distance dependent, the resonant frequencies will be complexly changed with the vertical vibration of the free end. Both model and experiment are built. The electromechanically coupled lumped-parameter model is presented. An electromechanical formulation and analytical expressions for the coupled nonlinear vibration response and voltage response are given. The entire structure is fabricated and mechanically attached to a electromagnetic shaker as a vibrating body via the fixed base, in order to couple the vibrations to the cantilever. The cantilevers are bonded with piezoelectric macro-fiber composite (MFC) materials (Model: M8514P2). The size of the cantilevers is 120*20mm2 and the thicknesses are separately 1mm, 0.8mm, 0.6mm. The prototype generator has a measured performance of 160.98 mW effective electrical power and 7.93 DC output voltage via the excitation level of 10m/s2. The 130% increase in the operating bandwidth is achieved. This device is promising to support low-power devices, peer-to-peer wireless nodes, and small-scale wireless sensor networks in ambient vibration environment.

Keywords: tri-cantilever, ambient vibration, energy harvesting, magnetic oscillator

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Authors: Hanee Ryu

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The supporting policies for renewable energy have been designed to deploy renewable energy technology targeting domestic market. The government encourages market creation through obligations such as FIT or RPS on an energy supplier. With these policy measures, the securing vast market needs to induce technology development. Furthermore, it is crucial that ensuring developing market can make the environment nurture the renewable energy industry. Overseas expansion to countries being in demand is essential under immature domestic market. Extending its business abroad can make the domestic company get the knowledge through learning-by-doing. Besides, operation in the countries to be rich in renewable resources such as weather conditions helps to develop proven track record required for verifying technologies. This paper figures out the factor to hamper the global market entry and build up the strategies to overcome difficulties. Survey conducted renewable energy company having overseas experiences at least once. Based on the survey we check the obstacle against exporting home goods and services. As a result, securing funds is salient fact to proceed to business. It is difficult that only private bank or investment agencies participate in the project under uncertainty which renewable energy development project bears inherently. These uncertainties need public fund such as ODA to encourage private sectors to start a business. Furthermore, international organizations such as IRENA or multilateral development banks as WBG play a role to guarantee the investment including risk insurance against uncertainty. It can also manage excavation business cooperating with developing countries and supplement inadequate government funding involved. With survey results strategies to obtain the order, the international organization places are categorized according to the type of getting a contract. This paper suggests 3 types approaching to the international organization project (going through international competitive bidding, using ODA and project financing) and specifies the role of government to support the domestic firms with running out of funds. Under renewable energy industry environment where hard to being created as a spontaneous market, government policy approach needs to motivate the actors to get into the business. It is one of the good strategies that countries with the low demand of renewable energies participate in the project international agencies order in the developing countries having abundant resources. This provides crucial guidance for the formulation of renewable energy development policy and planning with consideration of business opportunities and funding.

Keywords: exporting strategies, multilateral development banks, promoting in developing countries, renewable energy technologies

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Authors: Said Cheto, Khawla Oukaltouma, Imane Chamkhi, Ammar Ibn Yasser, Bouchra Benmrid, Ahmed Qaddoury, Lamfeddal Kouisni, Joerg Geistlinger, Youssef Zeroual, Adnane Bargaz, Cherki Ghoulam

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Our study aimed to assess, the role of inoculation of faba bean/wheat intercrops with selected rhizobacteria consortia gathering one rhizobia and two phosphate solubilizing bacteria “PSB” to alleviate the effects of combined water deficit and P limitation on Faba bean/ wheat intercrops versus monocrops under greenhouse conditions. One Vicia faba L variety (Aguadulce “Ag”), and one Triticum durum L. variety (Karim “K”) were grown as sole crops or intercrop in pots containing sterilized substrate (sand: peat 4:1v/v) added either with rock phosphate (RP) as the alone P source (P limitation) or with KH₂PO₄ in nutrient solution (P sufficient control). Plant inoculation was done using rhizobacterial consortia composed; C1(Rhizobium laguerreae, Kocuria sp, and Pseudomonas sp) and C2 (R. laguerreae, Rahnella sp, and Kocuria sp). Two weeks after inoculation, the plants were submitted to water deficit consisting of 40% of substrate water holding Capacity (WHC) versus 80% WHC for well-watered plants. At the flowering stage, the trial was assessed, and the results showed that inoculation with both consortia (C1 and C2) improved faba bean biomass in terms of shoots, roots, and nodules compared to inoculation with rhizobia alone, particularly C2 improved these parametres by 19.03, 78.99, and 72.73%, respectively. Leaf relative water content decreased under combined stress, particularly in response to C1 with a significant improvement of this parameter in wheat intercrops. For faba bean under P limitation, inoculation with C2 increased stomatal conductance (gs) by 35.73% compared to plants inoculated with rhizobia alone. Furthermore, the same inoculum C2 improved membrane stability by 44,33% versus 16,16% for C1 compared to inoculation with rhizobia alone under P deficit. For sole cropped faba bean plants, inoculation with both consortia improved N accumulation compared to inoculation with rhizobia alone with an increase of 70.75% under P limitation. Moreover, under the combined stress, intercropping inoculation with C2 improved plant biomass and N content (112.98%) in wheat plants, compared to the sole crop. Our finding revealed that consortium C2 might offer an agronomic advantage under water and P deficit and could be used as inoculum for enhancing faba bean and wheat production under both monocropping and intercropping systems.

Keywords: drought, phosphorus, intercropping, PSB, rhizobia, vicia faba, Triticum durum

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Authors: Thomas Rowan, Mohammed Seaid

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A fast finite volume solver for multi-layered shallow water flows with mass exchange and an erodible bed is developed. This enables the user to solve a number of complex sediment-based problems including (but not limited to), dam-break over an erodible bed, recirculation currents and bed evolution as well as levy and dyke failure. This research develops methodologies crucial to the under-standing of multi-sediment fluvial mechanics and waterway design. In this model mass exchange between the layers is allowed and, in contrast to previous models, sediment and fluid are able to transfer between layers. In the current study we use a two-step finite volume method to avoid the solution of the Riemann problem. Entrainment and deposition rates are calculated for the first time in a model of this nature. In the first step the governing equations are rewritten in a non-conservative form and the intermediate solutions are calculated using the method of characteristics. In the second stage, the numerical fluxes are reconstructed in conservative form and are used to calculate a solution that satisfies the conservation property. This method is found to be considerably faster than other comparative finite volume methods, it also exhibits good shock capturing. For most entrainment and deposition equations a bed level concentration factor is used. This leads to inaccuracies in both near bed level concentration and total scour. To account for diffusion, as no vertical velocities are calculated, a capacity limited diffusion coefficient is used. The additional advantage of this multilayer approach is that there is a variation (from single layer models) in bottom layer fluid velocity: this dramatically reduces erosion, which is often overestimated in simulations of this nature using single layer flows. The model is used to simulate a standard dam break. In the dam break simulation, as expected, the number of fluid layers utilised creates variation in the resultant bed profile, with more layers offering a higher deviation in fluid velocity . These results showed a marked variation in erosion profiles from standard models. The overall the model provides new insight into the problems presented at minimal computational cost.

Keywords: erosion, finite volume method, sediment transport, shallow water equations

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Authors: Akinwumi Omotayo, Badu-B Apraku, Joseph Olobasola, Petra Abdul Saghir, Yinka Sobowale

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In southwestern Nigeria, climate change has led to loss of at least two months of rainfall. Consequently, only one cycle of maize can now be grown because of the shorter duration of rainy season as against two cycles in the past. The Early and Extra-early maturing varieties of maize were originally developed for the semi-arid and arid zones of West and Central Africa where there are seasonal challenges of water threatening optimum performance of the traditional maize grown, which are commonly late in maturity (115 to 120 days). The early varieties of maize mature in 90 to 95 days; while the Extra-Early maize varieties reach physiological maturity in less than 90 days. It was broadly hypothesized that the extra early varieties of maize could mitigate the effects of climate change in southwestern Nigeria with higher levels of rainfall by reinstating the original two cycles of rain-fed maize crop. Trials were therefore carried out in southwestern Nigeria on the possibility of adapting the extra early maize to mitigate the effects of climate change. The trial was the Mother/Baby design. The mother trial involves the evaluation of extra-early varieties following ideal recommendations and closely supervised centrally at the University research farm and the Agricultural Development Programmes (ADPs). This requires farmers to observe and evaluate the technology and the management regime meant to precede the second stage of evaluation at several satellite farmers field managed by selected farmers. The Baby Trial is expected to provide a realistic assessment of the technology by farmers in their own environment. A stratified selection of thirty farmers for the Baby Trial ensured appropriate representation across the different categories of the farming population by age and gender. Data from the trials indicate that extra early maize can be grown in two cycles rain fed in south west Nigeria and a third and fourth cycle could be obtained with irrigation. However the long duration varieties outyielded the extra early maize in both the mother and baby trials. When harvested green, the extra early maize served as source of food between March and May when there was scarcity of food. This represents a major advantage. The study recommends that further work needs to be done to improve the yield of extra early maize to encourage farmers to adopt.

Keywords: adaptation, climate change, extra early, maize varieties, mitigation

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Authors: Ewa Toloczko

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Studies show that developing writing skills throughout years of formal foreign language instruction does not necessarily result in rewarding accomplishments among learners, nor an affirmative attitude they build towards written assignments. What causes this apparently wide-spread bias to writing might be a diminished relevance students attach to it, as opposed to the other productive skill — speaking, insufficient resources available for them to succeed, or the ways writing is approached by instructors, that is inapt teaching techniques that discourage rather that inflame learners’ engagement. The assumption underlying this presentation is that psychological and psycholinguistic factors constitute a key dimension of every writing process, and hence should be seriously considered in both material design and lesson planning. The author intends to demonstrate research in which writing tasks were conceived of as attitudinal rather than technical operations, and consequently turned into meaningful and socially-oriented incidents that students could relate to and have an active hand in. The instrument employed to achieve this purpose and to make writing even more interactive was the format of a project, a carefully devised series of tasks, which involved students as human beings, not only language learners. The projects rested upon the premise that the presence of peers and the teacher in class could be taken advantage of in a supportive rather than evaluative mode. In fact, the research showed that collaborative work and constant meaning negotiation reinforced not only bonds between learners, but also the language form and structure of the output. Accordingly, the role of the teacher shifted from the assessor to problem barometer, always ready to accept the slightest improvements in students’ language performance. This way, written verbal communication, which usually aims to merely manifest accuracy and coherent content for assessment, became part of the enterprise meant to emphasise its social aspect — the writer in real-life setting. The samples of projects show the spectrum of possibilities teachers have when exploring the domain of writing within school curriculum. The ideas are easy to modify and adjust to all proficiency levels and ages. Initially, however, they were meant to suit teenage and young adult learners of English as a foreign language in both European and Asian contexts.

Keywords: projects, psycholinguistic/ psychological dimension of writing, writing as a social enterprise, writing skills, written assignments

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Authors: Jaharlal Debbarma

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The ecological crisis has become a threat to earth’s well-being. Man’s ambitious desire of wealth, pleasure, fame, longevity and happiness has extracted natural resources so vastly that it is unable to sustain a healthy life. Man’s greed for wealth and power has caused the setting up of vast factories which further created the problem of air, water and noise pollution, which have adversely affected both fauna and flora.It is no secret that man uses his inherent powers of reason, intelligence and creativity to change his environment for his advantage. But man is not aware that the moral force he himself creates brings about corresponding changes in his environment to his weal or woe whether he likes it or not. As we are facing the global warming and the nature’s gift such as air and water has been so drastically polluted with disastrous consequences that man seek for a ways and means to overcome all this pollution problem as his health and life sustainability has been threaten and that is where man try to question about the moral ethics and value.It is where Buddhist philosophy has been emphasized deeply which gives us hope for overcoming this entire problem as Buddha himself emphasized in eradicating human suffering and Buddhism is the strongest form of humanism we have. It helps us to learn to live with responsibility, compassion, and loving kindness.It teaches us to be mindful in our action and thought as the environment unites every human being. If we fail to save it we will perish. If we can rise to meet the need to all which ecology binds us - humans, other species, other everything will survive together.My paper will look into the theory of Dependent Origination (Pratītyasamutpāda), Buddhist understanding of suffering (collective suffering), and Non-violence (Ahimsa) and an effort will be made to provide a new vision to Buddhist ecological perspective. The above Buddhist philosophy will be applied to ethical values and belief systems of modern society. The challenge will be substantially to transform the modern individualistic and consumeristic values. The stress will be made on the interconnectedness of the nature and the relation between human and planetary sustainability. In a way environmental crisis will be referred to “spiritual crisis” as A. Gore (1992) has pointed out. The paper will also give important to global consciousness, as well as to self-actualization and self-fulfillment. In the words of Melvin McLeod “Only when we combine environmentalism with spiritual practice, will we find the tools to make the profound personal transformations needed to address the planetary crisis?”

Keywords: dependent arising, collective ecological suffering, remediation, Buddhist approach

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Authors: A. Kesraoui, M. Seffen

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Applications of adsorption onto activated carbon for water treatment are well known. The process has been demonstrated to be widely effective for removing dissolved organic substances from wastewaters, but this treatment has a major drawback is the high operating cost. The main goal of our research work is to improve the retention capacity of Tunisian biomass for the depollution of industrial wastewater and retention of pollutants considered toxic. The biosorption process is based on the retention of molecules and ions onto a solid surface composed of biological materials. The evaluation of the potential use of these materials is important to propose as an alternative to the adsorption process generally expensive, used to remove organic compounds. Indeed, these materials are very abundant in nature and are low cost. Certainly, the biosorption process is effective to remove the pollutants, but it presents a slow kinetics. The improvement of the biosorption rates is a challenge to make this process competitive with respect to oxidation and adsorption onto lignocellulosic fibers. In this context, the alternating current appears as a new alternative, original and a very interesting phenomenon in the acceleration of chemical reactions. Our main goal is to increase the retention acceleration of dyes (indigo carmine, methylene blue) and phenol by using a new alternative: alternating current. The adsorption experiments have been performed in a batch reactor by adding some of the adsorbents in 150 mL of pollutants solution with the desired concentration and pH. The electrical part of the mounting comprises a current source which delivers an alternating current voltage of 2 to 15 V. It is connected to a voltmeter that allows us to read the voltage. In a 150 mL capacity cell, we plunged two zinc electrodes and the distance between two Zinc electrodes has been 4 cm. Thanks to alternating current, we have succeeded to improve the performance of activated carbon by increasing the speed of the indigo carmine adsorption process and reducing the treatment time. On the other hand, we have studied the influence of the alternating current on the biosorption rate of methylene blue onto Luffa cylindrica fibers and the hybrid material (Luffa cylindrica-ZnO). The results showed that the alternating current accelerated the biosorption rate of methylene blue onto the Luffa cylindrica and the Luffa cylindrica-ZnO hybrid material and increased the adsorbed amount of methylene blue on both adsorbents. In order to improve the removal of phenol, we performed the coupling between the alternating current and the biosorption onto two adsorbents: Luffa cylindrica and the hybrid material (Luffa cylindrica-ZnO). In fact, the alternating current has succeeded to improve the performance of adsorbents by increasing the speed of the adsorption process and the adsorption capacity and reduce the processing time.

Keywords: adsorption, alternating current, dyes, modeling

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Authors: Ali Alahmari

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Urban drainage in Saudi Arabia is an increasingly challenging issue due to factors such as climate change and rapid urban expansion. The existing infrastructure, based on traditional drainage systems, is not always able to cope with the increased precipitation, sometimes leading to rainwater runoff and floods causing disturbances and damage to property. Therefore, there is a need to find new ways of managing drainage, such as Sustainable Urban Drainage Systems (SUDS). The research has highlighted the main driving forces behind the need for change, revealed by the participants, to the need to adopt new ideas and approaches for urban drainage. However, while moving towards this, certain factors that may hinder the aim of using the experiences of other countries and taking advantage of innovative solutions. The research illustrates an initial conceptual model for these factors emerging from the analysis. It identifies some of the fundamental issues affecting the resistance to change towards the adoption of the concept of sustainability in Saudi Arabia, with Riyadh city as a case study. This was by using a qualitative approach, whereby, through two phases of fieldwork during 2013 and 2014, twenty-six semi-structured interviews were conducted with a number of representative officials and professionals from key government departments and organisations related to urban drainage management. Grounded Theory approach was followed to analyse the qualitative data obtained. Resistance to change was classified to: firstly: individual inertia (e.g. familiarity with the conventional solutions and approaches, lack of awareness, and considering sustainability as a marginal matter in urban planning). This resulted in not paying the desired attention, and impact on planning and setting priorities for development. Secondly: institutionalised inertia (e.g. lack of technical and design specifications for other unconventional drainage solutions, lack of consideration by decision makers in other disciplines such as contributions from environmental and geographical studies, and routine work and bureaucracy). This contributes to the weakness of decision-making, weakness in the role of research, and a lack of human resources. It seems that attitudes towards change may have reduced the ability to move forward towards sustainable development, in addition to contributing towards difficulties in some aspects of the decision-making process. Thus, the chapter provides insights into the current situation in Saudi Arabia and contributes to understanding the decisions that are made regarding change.

Keywords: climate change, new knowledge and approaches, resistance to change, Saudi Arabia, SUDS, urban drainage, urban expansion

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Authors: Mclee Kerolle

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For more than 50 years, the state of Hawaii has had the beginnings of a burgeoning commercial aerospace presence statewide. While Hawaii provides the aerospace industry with unique assets concerning geographic location, lack of range safety issues and other factors critical to aerospace development, Hawaii’s strategy and commitment for aerospace have been unclear. For this reason, this paper presents a comparative analysis of Hawaii’s space sector with two of the world’s leading space sectors, Colorado and the Netherlands, in order to provide a strategic plan that establishes a firm position going forward to support Hawaii’s aerospace development statewide. This plan will include financial and other economic incentives legislatively supported by the State to help grow and diversify Hawaii’s aerospace sector. The first part of this paper will examine the business model adopted by the Colorado Space Coalition (CSC), a group of industry stakeholders working to make Colorado a center of excellence for aerospace, as blueprint for growth in Hawaii’s space sector. The second section of this paper will examine the business model adopted by the Netherlands Space Business Incubation Centre (NSBIC), a European Space Agency (ESA) affiliated program that offers business support for entrepreneurs to turn space-connected business ideas into commercial companies. This will serve as blueprint to incentivize space businesses to launch and develop in Hawaii. The third section of this paper will analyze the current policies both CSC, and NSBIC implores to promote industry expansion and legislative advocacy. The final section takes the findings from both space sectors and applies their most adaptable features to a Hawaii specific space business model that takes into consideration the unique advantage and disadvantages found in developing Hawaii’s space sector. The findings of this analysis will show that the development of a strategic plan based on a comparative analysis that creates high technology jobs and new pathways for a trained workforce in the space sector, as well as elicit state support and direction, will achieve the goal of establishing Hawaii as a center of space excellence. This analysis will also serve as a signal to the federal, private sector and international community that Hawaii is indeed serious about developing its’ aerospace industry. Ultimately this analysis and subsequent aerospace development plan will serve as a blueprint for the benefit of all space-faring nations seeking to develop their space sectors.

Keywords: Colorado, Hawaii, Netherlands, space policy

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Authors: Susumu Fukita, Hiromi Kawasaki, Satoko Yamasaki, Kotomi Yamashita, Tomoko Iki

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The increase in the number of workers with mental health problems has become an issue. Many workers work in small- and medium-sized enterprises, which often support local employment and economy, especially in underpopulated mountainous areas. It is important for managers to take mental health measures for employees since there is no budget to hire health staff in small- and medium-sized enterprises. It is necessary to understand the manager's attitude toward the mental health of employees and to publicly support the manager in promoting mental health measures for employees. The purpose of this study was to study the awareness of managers of small- and medium-sized enterprises regarding the mental health of employees and to consider support for managers to take measures for the mental health of employees. Semi-structured interviews were conducted with six managers of small- and medium-sized enterprises in underpopulated mountainous areas in November 2019. Managers were asked about their awareness of the mental health of their employees. Qualitative descriptive analysis was used, and subcategories and categories were extracted. Four categories emerged. Regarding the mental health of employees, the managers acknowledged that if the appearance and behavior of the employees do not interfere with their lives, the manager judges that the employees’ mental health is normal. It was also found that the managers acknowledged that there is a comfortable working environment due to the characteristics of the underpopulated mountainous area. On the other hand, the managers acknowledged that employees are dissatisfied with salaries and management systems. In addition, it was found the manager acknowledged that some employees retire due to mental health problems. Although managers recognized that employees may be dissatisfied with salaries, they also recognized that there was a comfortable working environment due to the characteristics of the areas, with good interpersonal relationships. Economic challenges are difficult to solve in underpopulated mountainous areas. It is useful to consider measures that take advantage of the characteristics of the areas where it is easy to work because of good relations with each other, for example, to create a family-like workplace culture where managers and employees can engage in daily conversation. The managers judged that the employees were in good health if there was no interference with their lives. However, it is too late to take measures at the stage when it becomes an obstacle to life. Therefore, it is necessary to provide training for managers to learn observation techniques by which they quickly notice changes in the situation of employees and give appropriate responses; and to set up a contact point for managers to consult. Local governments should actively provide public support such as training for managers and establishing consultation desks to maintain valuable employment and local economics in underpopulated mountainous areas.

Keywords: employer, mental health, small- and medium- sized enterprises, underpopulated areas

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Authors: Dipo Dunsin, Mohamed C. Ghanem, Karim Ouazzane

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Digital investigators often have a hard time spotting evidence in digital information. It has become hard to determine which source of proof relates to a specific investigation. A growing concern is that the various processes, technology, and specific procedures used in the digital investigation are not keeping up with criminal developments. Therefore, criminals are taking advantage of these weaknesses to commit further crimes. In digital forensics investigations, artificial intelligence is invaluable in identifying crime. It has been observed that an algorithm based on artificial intelligence (AI) is highly effective in detecting risks, preventing criminal activity, and forecasting illegal activity. Providing objective data and conducting an assessment is the goal of digital forensics and digital investigation, which will assist in developing a plausible theory that can be presented as evidence in court. Researchers and other authorities have used the available data as evidence in court to convict a person. This research paper aims at developing a multiagent framework for digital investigations using specific intelligent software agents (ISA). The agents communicate to address particular tasks jointly and keep the same objectives in mind during each task. The rules and knowledge contained within each agent are dependent on the investigation type. A criminal investigation is classified quickly and efficiently using the case-based reasoning (CBR) technique. The MADIK is implemented using the Java Agent Development Framework and implemented using Eclipse, Postgres repository, and a rule engine for agent reasoning. The proposed framework was tested using the Lone Wolf image files and datasets. Experiments were conducted using various sets of ISA and VMs. There was a significant reduction in the time taken for the Hash Set Agent to execute. As a result of loading the agents, 5 percent of the time was lost, as the File Path Agent prescribed deleting 1,510, while the Timeline Agent found multiple executable files. In comparison, the integrity check carried out on the Lone Wolf image file using a digital forensic tool kit took approximately 48 minutes (2,880 ms), whereas the MADIK framework accomplished this in 16 minutes (960 ms). The framework is integrated with Python, allowing for further integration of other digital forensic tools, such as AccessData Forensic Toolkit (FTK), Wireshark, Volatility, and Scapy.

Keywords: artificial intelligence, computer science, criminal investigation, digital forensics

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Authors: Stephanie Chen, Mitja Echim, Christof Büskens

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To describe and propagate the behavior of a system mathematical models are formulated. Parameter identification is used to adapt the coefficients of the underlying laws of science. For complex systems this approach can be incomplete and hence imprecise and moreover too slow to be computed efficiently. Therefore, these models might be not applicable for the numerical optimization of real systems, since these techniques require numerous evaluations of the models. Moreover not all quantities necessary for the identification might be available and hence the system must be adapted manually. Therefore, an approach is described that generates models that overcome the before mentioned limitations by not focusing on physical laws, but on measured (sensor) data of real systems. The approach is more general since it generates models for every system detached from the scientific background. Additionally, this approach can be used in a more general sense, since it is able to automatically identify correlations in the data. The method can be classified as a multivariate data regression analysis. In contrast to many other data regression methods this variant is also able to identify correlations of products of variables and not only of single variables. This enables a far more precise and better representation of causal correlations. The basis and the explanation of this method come from an analytical background: the series expansion. Another advantage of this technique is the possibility of real-time adaptation of the generated models during operation. Herewith system changes due to aging, wear or perturbations from the environment can be taken into account, which is indispensable for realistic scenarios. Since these data driven models can be evaluated very efficiently and with high precision, they can be used in mathematical optimization algorithms that minimize a cost function, e.g. time, energy consumption, operational costs or a mixture of them, subject to additional constraints. The proposed method has successfully been tested in several complex applications and with strong industrial requirements. The generated models were able to simulate the given systems with an error in precision less than one percent. Moreover the automatic identification of the correlations was able to discover so far unknown relationships. To summarize the above mentioned approach is able to efficiently compute high precise and real-time-adaptive data-based models in different fields of industry. Combined with an effective mathematical optimization algorithm like WORHP (We Optimize Really Huge Problems) several complex systems can now be represented by a high precision model to be optimized within the user wishes. The proposed methods will be illustrated with different examples.

Keywords: adaptive modeling, automatic identification of correlations, data based modeling, optimization

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Authors: Athena Daniilidou, Maria Platsidou

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Resilience is considered to greatly affect the personal and occupational wellbeing and efficacy of individuals; therefore, it has been widely studied in the social and behavioral sciences. Given its significance, several scales have been created to assess resilience of children and adults. However, most of these scales focus on examining only the internal protective or risk factors that affect the levels of resilience. The aim of the present study is to create a reliable scale that assesses both the internal and the external protective factors that affect Greek teachers’ levels of resilience. Participants were 136 secondary school teachers (89 females, 47 males) from urban areas of Greece. Connor-Davidson Resilience Scale (CD-Risc) and Resilience Scale for Adults (RSA) were used to collect the data. First, exploratory factor analysis was employed to investigate the inner structure of each scale. For both scales, the analyses revealed a differentiated factor solution compared to the ones proposed by the creators. That prompt us to create a scale that would combine the best fitting subscales of the CD-Risc and the RSA. To this end, the items of the four factors with the best fit and highest reliability were used to create the ‘Teachers' resilience scale’. Exploratory factor analysis revealed that the scale assesses the following protective/risk factors: Personal Competence and Strength (9 items, α=.83), Family Cohesion Spiritual Influences (7 items, α=.80), Social Competence and Peers Support (7 items, α=.78) and Spiritual Influence (3 items, α=.58). This four-factor model explained 49,50% of the total variance. In the next step, a confirmatory factor analysis was performed on the 26 items of the derived scale to test the above factor solution. The fit of the model to the data was good (χ2/292 = 1.245, CFI = .921, GFI = .829, SRMR = .074, CI90% = .026-,056, RMSEA = 0.43), indicating that the proposed scale can validly measure the aforementioned four aspects of teachers' resilience and thus confirmed its factorial validity. Finally, analyses of variance were performed to check for individual differences in the levels of teachers' resilience in relation to their gender, age, marital status, level of studies, and teaching specialty. Results were consistent to previous findings, thus providing an indication of discriminant validity for the instrument. This scale has the advantage of assessing both the internal and the external protective factors of resilience in a brief yet comprehensive way, since it consists 26 items instead of the total of 58 of the CD-Risc and RSA scales. Its factorial inner structure is supported by the relevant literature on resilience, as it captures the major protective factors of resilience identified in previous studies.

Keywords: protective factors, resilience, scale development, teachers

Procedia PDF Downloads 281

Authors: Priya Jaswal, Vivek, S. K. Sinha

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One of the most important and complicated factors influencing the functional performance of unpaved roads is traffic loading. The complexity of traffic loading is caused by the variable magnitude and frequency of load, which causes unpaved roads to fail prematurely. Unpaved roads are low-volume roads, and as peri-urbanization increases, unpaved roads act as a means to boost the rural economy. This has also increased traffic on unpaved roads, intensifying the issue of settlement, rutting, and fatigue failure. This is a major concern for unpaved roads built on poor subgrade soil, as excessive rutting caused by heavy loads can cause driver discomfort, vehicle damage, and an increase in maintenance costs. Some researchers discovered that when a consistent static load is exerted as opposed to a rapidly changing load, the rate of deformation of unpaved roads increases. Previously, some of the most common methods for overcoming the problem of rutting and fatigue failure included chemical stabilisation, fibre reinforcement, and so on. However, due to their high cost, engineers' attention has shifted to geotextiles which are used as reinforcement in unpaved roads. Geotextiles perform the function of filtration, lateral confinement of base material, vertical restraint of subgrade soil, and the tension membrane effect. The use of geotextiles in unpaved roads increases the strength of unpaved roads and is an economically viable method because it reduces the required aggregate thickness, which would need less earthwork, and is thus recommended for unpaved road applications. The majority of geotextiles used previously were polymeric, but with a growing awareness of sustainable development to preserve the environment, researchers' focus has shifted to natural fibres. Coir is one such natural fibre that possesses the advantage of having a higher tensile strength than other bast fibres, being eco-friendly, low in cost, and biodegradable. However, various researchers have discovered that the surface of coir fibre is covered with various impurities, voids, and cracks, which act as a plane of weakness and limit the potential application of coir geotextiles. To overcome this limitation, chemical surface modification of coir geotextiles is widely accepted by researchers because it improves the mechanical properties of coir geotextiles. The current paper reviews the effect of using treated coir geotextiles as reinforcement on the load-deformation behaviour of a two-layered unpaved road model.

Keywords: coir, geotextile, treated, unpaved

Procedia PDF Downloads 76

Authors: Xiao-Hua Zhu, Xin Yuan, Yi-Ran Zhao

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High-cadmium pollution in rice is a serious problem in many parts of China. Many kinds of remediation technologies have been tested and applied in many farmlands. Because of the productive function of the farmland, most technologies are inappropriate due to their destruction to the tillage soil layer. And the large labours and expensive fees of many technologies are also the restrictive factors for their applications. The conception of 'Root Micro-Geochemical Barrier' was proposed to reduce cadmium (Cd) bioavailability and the concentration of the cadmium in rice. Remediation and mitigation techniques were demonstrated on contaminated farmland in the downstream of some mine. According to the rule of rice growth, Cd would be absorbed by the crops in every growth stage, and the plant-absorb efficiency in the first stage of the tillering stage is almost the highest. We should create a method to protect the crops from heavy metal pollution, which could begin to work from the early growth stage. Many materials with repair property get our attention. The materials will create a barrier preventing Cd from being absorbed by the crops during all the growing process because the material has the ability to adsorb soil-Cd and making it losing its migration activity. And we should choose a good chance to put the materials into the crop-growing system cheaply as soon as early. Per plant, rice has a little root system scope, which makes the roots reach about 15cm deep and 15cm wide. So small root radiation area makes it possible for all the Cd approaching the roots to be adsorbed with a small amount of adsorbent. Mixing the remediation materials with the seed-raising soli and adding them to the tillage soil in the process of transplanting seedlings, we can control the soil-Cd activity in the range of roots to reduce the Cd-amount absorbed by the crops. Of course, the mineral materials must have enough adsorptive capacity and no additional pollution. More than 3000 square meters farmlands have been remediated. And on the application of root micro-geochemical barrier, the Cd-concentration in rice and the remediation-cost have been decreased by 90% and 80%, respectively, with little extra labour brought to the farmers. The Cd-concentrations in rice from remediated farmland have been controlled below 0.1 ppm. The remediation of one acre of contaminated cropland costs less than $100. The concept has its advantage in the remediation of paddy field contaminated by Cd, especially for the field with outside pollution sources.

Keywords: cadmium pollution, growth stage, cost, root micro-geochemistry barrier

Procedia PDF Downloads 62

Authors: Swati Tomar, Sunil Kumar Gupta

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Anammox is a novel and promising technology that has changed the traditional concept of biological nitrogen removal. The process facilitates direct oxidation of ammonical nitrogen under anaerobic conditions with nitrite as an electron acceptor without the addition of external carbon sources. The present study investigated the feasibility of anammox hybrid reactor (AHR) combining the dual advantages of suspended and attached growth media for biodegradation of ammonical nitrogen in wastewater. The experimental unit consisted of 4 nos. of 5L capacity AHR inoculated with mixed seed culture containing anoxic and activated sludge (1:1). The process was established by feeding the reactors with synthetic wastewater containing NH4-H and NO2-N in the ratio 1:1 at HRT (hydraulic retention time) of 1 day. The reactors were gradually acclimated to higher ammonium concentration till it attained pseudo steady state removal at a total nitrogen concentration of 1200 mg/l. During this period, the performance of the AHR was monitored at twelve different HRTs varying from 0.25-3.0 d with increasing NLR from 0.4 to 4.8 kg N/m3d. AHR demonstrated significantly higher nitrogen removal (95.1%) at optimal HRT of 1 day. Filter media in AHR contributed an additional 27.2% ammonium removal in addition to 72% reduction in the sludge washout rate. This may be attributed to the functional mechanism of filter media which acts as a mechanical sieve and reduces the sludge washout rate many folds. This enhances the biomass retention capacity of the reactor by 25%, which is the key parameter for successful operation of high rate bioreactors. The effluent nitrate concentration, which is one of the bottlenecks of anammox process was also minimised significantly (42.3-52.3 mg/L). Process kinetics was evaluated using first order and Grau-second order models. The first-order substrate removal rate constant was found as 13.0 d-1. Model validation revealed that Grau second order model was more precise and predicted effluent nitrogen concentration with least error (1.84±10%). A new mathematical model based on mass balance was developed to predict N2 gas in AHR. The mass balance model derived from total nitrogen dictated significantly higher correlation (R2=0.986) and predicted N2 gas with least error of precision (0.12±8.49%). SEM study of biomass indicated the presence of the heterogeneous population of cocci and rod shaped bacteria of average diameter varying from 1.2-1.5 mm. Owing to enhanced NRE coupled with meagre production of effluent nitrate and its ability to retain high biomass, AHR proved to be the most competitive reactor configuration for dealing with nitrogen laden wastewater.

Keywords: anammox, filter media, kinetics, nitrogen removal

Procedia PDF Downloads 364

Authors: Fatema Akram, Mohammad G. Rasul, M. Masud K. Khan, M. Sharif I. I. Amir

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Australia is a country of some 7,700 million square kilometres with a population of about 22.6 million. At present water security is a major challenge for Australia. In some areas the use of water resources is approaching and in some parts it is exceeding the limits of sustainability. A focal point of proposed national water conservation programs is the recycling of both urban storm-water and treated wastewater. But till now it is not widely practiced in Australia, and particularly storm-water is neglected. In Australia, only 4% of storm-water and rainwater is recycled, whereas less than 1% of reclaimed wastewater is reused within urban areas. Therefore, accurately monitoring, assessing and predicting the availability, quality and use of this precious resource are required for better management. As storm-water is usually of better quality than untreated sewage or industrial discharge, it has better public acceptance for recycling and reuse, particularly for non-potable use such as irrigation, watering lawns, gardens, etc. Existing storm-water recycling practice is far behind of research and no robust technologies developed for this purpose. Therefore, there is a clear need for using modern technologies for assessing feasibility of storm-water harvesting and reuse. Numerical modelling has, in recent times, become a popular tool for doing this job. It includes complex hydrological and hydraulic processes of the study area. The hydrologic model computes storm-water quantity to design the system components, and the hydraulic model helps to route the flow through storm-water infrastructures. Nowadays water quality module is incorporated with these models. Integration of Geographic Information System (GIS) with these models provides extra advantage of managing spatial information. However for the overall management of a storm-water harvesting project, Decision Support System (DSS) plays an important role incorporating database with model and GIS for the proper management of temporal information. Additionally DSS includes evaluation tools and Graphical user interface. This research aims to critically review and discuss all the aspects of storm-water harvesting and reuse such as available guidelines of storm-water harvesting and reuse, public acceptance of water reuse, the scopes and recommendation for future studies. In addition to these, this paper identifies, understand and address the importance of modern technologies capable of proper management of storm-water harvesting and reuse.

Keywords: storm-water management, storm-water harvesting and reuse, numerical modelling, geographic information system, decision support system, database

Procedia PDF Downloads 348

Authors: Bill Wang, Paul Childerhouse, Yuanfei Kang

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Purpose: The research is to extend resource orchestration theory (ROT) into supply chain management (SCM) area to investigate the dyadic relationships at both individual and organizational levels in supply chain integration (SCI). Also, we try to explore the interaction mechanism between inter-personal relationships (IPRs) and inter-organizational (IORs) during the whole SCI process. Methodology/approach: The research employed an exploratory multiple case study approach of four New Zealand companies. The data was collected via semi-structured interviews with top, middle, and lower level managers and operators from different departments of both suppliers and customers triangulated with company archival data. Findings: The research highlights the important role of both IPRs and IORs in the whole SCI process. Both IPRs and IORs are valuable, inimitable resources but IORs are formal and exterior while IPRs are informal and subordinated. In the initial stage of SCI process, IPRs are seen as key resources antecedents to IOR building while three IPRs dimensions work differently: personal credibility acts as an icebreaker to strengthen the confidence forming IORs, and personal affection acts as a gatekeeper, whilst personal communication expedites the IORs process. In the maintenance and development stage, IORs and IPRs interact each other continuously: good interaction between IPRs and IORs can facilitate SCI process while the bad interaction between IPRs can damage the SCI process. On the other hand, during the life-cycle of SCI process, IPRs can facilitate the formation, development of IORs while IORs development can cultivate the ties of IPRs. Out of the three dimensions of IPRs, Personal communication plays a more important role to develop IORs than personal credibility and personal affection. Originality/value: This research contributes to ROT in supply chain management literature by highlighting the interaction of IPRs and IORs in SCI. The intangible resources and capabilities of three dimensions of IPRs need to be orchestrated and nurtured to achieve efficient and effective IORs in SCI. Also, IPRs and IORs need to be orchestrated in terms of breadth, depth, and life-cycle of whole SCI process. Our study provides further insight into the rarely explored inter-personal level of SCI. Managerial implications: Our research provides top management with further evidence of the significance roles of IPRs at different levels when working with trading partners. This highlights the need to actively manage and develop these soft IPRs skills as an intangible competitive resource. Further, the research identifies when staff with specific skills and connections should be utilized during the different stages of building and maintaining inter-organizational ties. More importantly, top management needs to orchestrate and balance the resources of IPRs and IORs.

Keywords: case study, inter-organizational relationships, inter-personal relationships, resource orchestration, supply chain integration

Procedia PDF Downloads 213

Authors: Huseyin Guler, Cigdem Kosar

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The aim of this study is to propose Bridge estimator for seasonal unit root tests. Seasonality is an important factor for many economic time series. Some variables may contain seasonal patterns and forecasts that ignore important seasonal patterns have a high variance. Therefore, it is very important to eliminate seasonality for seasonal macroeconomic data. There are some methods to eliminate the impacts of seasonality in time series. One of them is filtering the data. However, this method leads to undesired consequences in unit root tests, especially if the data is generated by a stochastic seasonal process. Another method to eliminate seasonality is using seasonal dummy variables. Some seasonal patterns may result from stationary seasonal processes, which are modelled using seasonal dummies but if there is a varying and changing seasonal pattern over time, so the seasonal process is non-stationary, deterministic seasonal dummies are inadequate to capture the seasonal process. It is not suitable to use seasonal dummies for modeling such seasonally nonstationary series. Instead of that, it is necessary to take seasonal difference if there are seasonal unit roots in the series. Different alternative methods are proposed in the literature to test seasonal unit roots, such as Dickey, Hazsa, Fuller (DHF) and Hylleberg, Engle, Granger, Yoo (HEGY) tests. HEGY test can be also used to test the seasonal unit root in different frequencies (monthly, quarterly, and semiannual). Another issue in unit root tests is the lag selection. Lagged dependent variables are added to the model in seasonal unit root tests as in the unit root tests to overcome the autocorrelation problem. In this case, it is necessary to choose the lag length and determine any deterministic components (i.e., a constant and trend) first, and then use the proper model to test for seasonal unit roots. However, this two-step procedure might lead size distortions and lack of power in seasonal unit root tests. Recent studies show that Bridge estimators are good in selecting optimal lag length while differentiating nonstationary versus stationary models for nonseasonal data. The advantage of this estimator is the elimination of the two-step nature of conventional unit root tests and this leads a gain in size and power. In this paper, the Bridge estimator is proposed to test seasonal unit roots in a HEGY model. A Monte-Carlo experiment is done to determine the efficiency of this approach and compare the size and power of this method with HEGY test. Since Bridge estimator performs well in model selection, our approach may lead to some gain in terms of size and power over HEGY test.

Keywords: bridge estimators, HEGY test, model selection, seasonal unit root

Procedia PDF Downloads 309

Authors: W. A. Nalaka Wijesooriya

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The increasing paddy production, stabilization of domestic rice consumption and the increasing dynamism of rice processing and domestic markets call for a rethinking of the general direction of the rice milling industry in Sri Lanka. The main purpose of the study was to explore levels of concentration in rice milling industry in Polonnaruwa and Hambanthota which are the major hubs of the country for rice milling. Concentration indices reveal that the rice milling industry in Polonnaruwa operates weak oligopsony and is highly competitive in Hambanthota. According to the actual quantity of paddy milling per day, 47 % is less than 8Mt/Day, while 34 % is 8-20 Mt/day, and the rest (19%) is greater than 20 Mt/day. In Hambanthota, nearly 50% of the mills belong to the range of 8-20 Mt/day. Lack of experience of the milling industry, poor knowledge on milling technology, lack of capital and finding an output market are the major entry barriers to the industry. Major problems faced by all the rice millers are the lack of a uniform electricity supply and low quality paddy. Many of the millers emphasized that the rice ceiling price is a constraint to produce quality rice. More than 80% of the millers in Polonnaruwa which is the major parboiling rice producing area have mechanical dryers. Nearly 22% millers have modern machineries like color sorters, water jet polishers. Major paddy purchasing method of large scale millers in Polonnaruwa is through brokers. In Hambanthota major channel is miller purchasing from paddy farmers. Millers in both districts have major rice selling markets in Colombo and suburbs. Huge variation can be observed in the amount of pledge (for paddy storage) loans. There is a strong relationship among the storage ability, credit affordability and the scale of operation of rice millers. The inter annual price fluctuation ranged 30%-35%. Analysis of market margins by using series of secondary data shows that farmers’ share on rice consumer price is stable or slightly increases in both districts. In Hambanthota a greater share goes to the farmer. Only four mills which have obtained the Good Manufacturing Practices (GMP) certification from Sri Lanka Standards Institution can be found. All those millers are small quantity rice exporters. Priority should be given for the Small and medium scale millers in distribution of storage paddy of PMB during the off season. The industry needs a proper rice grading system, and it is recommended to introduce a ceiling price based on graded rice according to the standards. Both husk and rice bran were underutilized. Encouraging investment for establishing rice oil manufacturing plant in Polonnaruwa area is highly recommended. The current taxation procedure needs to be restructured in order to ensure the sustainability of the industry.

Keywords: conduct, performance, structure (SCP), rice millers

Procedia PDF Downloads 311

Authors: Fathi Abid, Bilel Kaffel

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The olive tree, the olive harvest during winter season and the production of olive oil better known by professionals under the name of the crushing operation have interested institutional traders such as olive-oil offices and private companies such as food industry refining and extracting pomace olive oil as well as export-import public and private companies specializing in olive oil. The major problem facing producers of olive oil each winter campaign, contrary to what is expected, it is not whether the harvest will be good or not but whether the sale price will allow them to cover production costs and achieve a reasonable margin of profit or not. These questions are entirely legitimate if we judge by the importance of the issue and the heavy complexity of the uncertainty and competition made tougher by a high level of indebtedness and the experience and expertise of speculators and producers whose objectives are sometimes conflicting. The aim of this paper is to study the formation mechanism of olive oil prices in order to learn about speculators’ behavior and expectations in the market, how they contribute by their industry knowledge and their financial alliances and the size the financial challenge that may be involved for them to build private information hoses globally to take advantage. The methodology used in this paper is based on two stages, in the first stage we study econometrically the formation mechanisms of olive oil price in order to understand the market participant behavior by implementing ARMA, SARMA, GARCH and stochastic diffusion processes models, the second stage is devoted to prediction purposes, we use a combined wavelet- ANN approach. Our main findings indicate that olive oil market participants interact with each other in a way that they promote stylized facts formation. The unstable participant’s behaviors create the volatility clustering, non-linearity dependent and cyclicity phenomena. By imitating each other in some periods of the campaign, different participants contribute to the fat tails observed in the olive oil price distribution. The best prediction model for the olive oil price is based on a back propagation artificial neural network approach with input information based on wavelet decomposition and recent past history.

Keywords: olive oil price, stylized facts, ARMA model, SARMA model, GARCH model, combined wavelet-artificial neural network, continuous-time stochastic volatility mode

Procedia PDF Downloads 317

Authors: Suraj D. Khadka, Priyantha W. Jayawickrama

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In search of a sustainable construction material, geopolymer has been investigated for past decades to evaluate its advantage over conventional products. Synthesis of geopolymer requires a source of aluminosilicate mixed with sodium hydroxide and sodium silicate at different proportions to maintain a Si/Al molar ratio of 1-3 and Na/Al molar ratio of unity. A comprehensive geopolymer study was performed with Metakaolin and Class C Fly ash as primary aluminosilicate sources. Synthesized geopolymer was analyzed for time-dependent viscosity, setting period and strength at varying initial moisture content, curing temperature and humidity. Different concentration of Ca(OH)₂ and CaSO₄.2H₂O were added to vary the amount of calcium contained in synthesized geopolymer. Influence of calcium content in unconfined compressive strength behavior of geopolymer were analyzed. Finally, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was performed to investigate the hardened product. It was observed that fly ash based geopolymer had shortened setting time and faster increase in viscosity as compared to geopolymer synthesized from metakaolin. This was primarily attributed to higher calcium content resulting in formation of calcium silicate hydrates (CSH). SEM-EDS was performed to verify the presence of CSH phases. Spectral analysis of geopolymer prepared by addition of Ca(OH)₂ and CaSO₄.2H₂O indicated higher CSH phases at higher concentration. It was observed that lower concentration of added calcium favored strength gain in geopolymer. However, at higher calcium concentration, decrease in strength was observed. Strength variation was also observed with humidity at initial curing condition. At 100% humidity, geopolymer with added calcium presented higher strength compared to samples cured at ambient humidity condition (40%). Reduction in strength in these samples at lower humidity was primarily attributed to reduction in moisture content in specimen due to the formation of CSH phases and loss of moisture through evaporation. For low calcium content geopolymers, with increase in temperature, gain in strength was observed with maximum strength observed at 200 ˚C. However, samples with higher calcium content demonstrated severe cracking resulting in low strength at elevated temperatures.

Keywords: calcium silicate hydrates, geopolymer, humidity, Scanning Electron Microscopy-Energy Dispersive Spectroscopy, unconfined compressive strength

Procedia PDF Downloads 102

Authors: Cagri Mollamahmutoglu, Aykut Levent, Ali Mercan

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Micro-beams are one of the most common components of Nano-Electromechanical Systems (NEMS) and Micro Electromechanical Systems (MEMS). For this reason, static bending, buckling, and free vibration analysis of micro-beams have been the subject of many studies. In addition, micro-beams restrained with elastic type foundations have been of particular interest. In the analysis of microstructures, closed-form solutions are proposed when available, but most of the time solutions are based on numerical methods due to the complex nature of the resulting differential equations. Thus, a robust and efficient solution method has great importance. In this study, a mixed finite element formulation is obtained for a functionally graded Timoshenko micro-beam resting on two-parameter elastic foundation. In the formulation modified couple stress theory is utilized for the micro-scale effects. The equation of motion and boundary conditions are derived according to Hamilton’s principle. A functional, derived through a scientific procedure based on Gateaux Differential, is proposed for the bending and buckling analysis which is equivalent to the governing equations and boundary conditions. Most important advantage of the formulation is that the mixed finite element formulation allows usage of C₀ type continuous shape functions. Thus shear-locking is avoided in a built-in manner. Also, element matrices are sparsely populated and can be easily calculated with closed-form integration. In this framework results concerning the effects of micro-scale length parameter, power-law parameter, aspect ratio and coefficients of partially or fully continuous elastic foundation over the static bending, buckling, and free vibration response of FG-micro-beam under various boundary conditions are presented and compared with existing literature. Performance characteristics of the presented formulation were evaluated concerning other numerical methods such as generalized differential quadrature method (GDQM). It is found that with less computational burden similar convergence characteristics were obtained. Moreover, formulation also includes a direct calculation of the micro-scale related contributions to the structural response as well.

Keywords: micro-beam, functionally graded materials, two-paramater elastic foundation, mixed finite element method

Procedia PDF Downloads 132

Authors: Gela Gelashvili, David Gelenidze, Sulkhan Nanobashvili, Irakli Nanobashvili, George Tavkhelidze, Tsiuri Sitchinava

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Development of new highly efficient plasma arc combustion system of pulverized coal is presented. As it is well-known, coal is one of the main energy carriers by means of which electric and heat energy is produced in thermal power stations. The quality of the extracted coal decreases very rapidly. Therefore, the difficulties associated with its firing and complete combustion arise and thermo-chemical preparation of pulverized coal becomes necessary. Usually, other organic fuels (mazut-fuel oil or natural gas) are added to low-quality coal for this purpose. The fraction of additional organic fuels varies within 35-40% range. This decreases dramatically the economic efficiency of such systems. At the same time, emission of noxious substances in the environment increases. Because of all these, intense development of plasma combustion systems of pulverized coal takes place in whole world. These systems are equipped with Non-Transferred Plasma Arc Torches. They allow practically complete combustion of pulverized coal (without organic additives) in boilers, increase of energetic and financial efficiency. At the same time, emission of noxious substances in the environment decreases dramatically. But, the non-transferred plasma torches have numerous drawbacks, e.g. complicated construction, low service life (especially in the case of high power), instability of plasma arc and most important – up to 30% of energy loss due to anode cooling. Due to these reasons, intense development of new plasma technologies that are free from these shortcomings takes place. In our proposed system, pulverized coal-air mixture passes through plasma arc area that burns between to carbon electrodes directly in pulverized coal muffler burner. Consumption of the carbon electrodes is low and does not need a cooling system, but the main advantage of this method is that radiation of plasma arc directly impacts on coal-air mixture that accelerates the process of thermo-chemical preparation of coal to burn. To ensure the stability of the plasma arc in such difficult conditions, we have developed a power source that provides fixed current during fluctuations in the arc resistance automatically compensated by the voltage change as well as regulation of plasma arc length over a wide range. Our combustion system where plasma arc acts directly on pulverized coal-air mixture is simple. This should allow a significant improvement of pulverized coal combustion (especially low-quality coal) and its economic efficiency. Preliminary experiments demonstrated the successful functioning of the system.

Keywords: coal combustion, plasma arc, plasma torches, pulverized coal

Procedia PDF Downloads 143

Authors: O. E. Akinyemi, P. O. Alege, O. O. Ajayi, L. A. Amaghionyediwe, A. A. Ogundipe

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Nigeria as an oil-producing developing country in Africa is one of the many countries that had been subsidizing consumption of fossil fuel. Despite the numerous advantage of this policy ranging from increased energy access, fostering economic and industrial development, protecting the poor households from oil price shocks, political considerations, among others; they have been found to impose economic cost, wasteful, inefficient, create price distortions discourage investment in the energy sector and contribute to environmental pollution. These negative consequences coupled with the fact that the policy had not been very successful at achieving some of its stated objectives, led to a number of organisations and countries such as the Group of 7 (G7), World Bank, International Monetary Fund (IMF), International Energy Agency (IEA), Organisation for Economic Co-operation and Development (OECD), among others call for global effort towards reforming fossil fuel subsidies. This call became necessary in view of seeking ways to harmonise certain existing policies which may by design hamper current effort at tackling environmental concerns such as climate change. This is in addition to driving a green growth strategy and low carbon development in achieving sustainable development. The energy sector is identified to play a vital role. This study thus investigates the prospects of using fuel subsidy reform as a viable tool in driving an economy that de-emphasizes carbon growth in Nigeria. The method used is the Johansen and Engle-Granger two-step Co-integration procedure in order to investigate the existence or otherwise of a long-run equilibrium relationship for the period 1971 to 2011. Its theoretical framework is rooted in the Environmental Kuznet Curve (EKC) hypothesis. In developing three case scenarios (case of subsidy payment, no subsidy payment and effective subsidy), findings from the study supported evidence of a long run sustainable equilibrium model. Also, estimation results reflected that the first and the second scenario do not significantly influence the indicator of environmental quality. The implication of this is that in reforming fuel subsidy to drive environmental quality for an economy like Nigeria, strong and effective regulatory framework (measure that was interacted with fuel subsidy to yield effective subsidy) is essential.

Keywords: environmental quality, fuel subsidy, green growth, low carbon growth strategy

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Authors: Masanori Kimura

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Due to the decline of the 18-year-old population, Japanese universities have a tendency to convert their form of employment from tenured positions to fixed-term positions for newly hired teachers. The advantage of this is that universities can be more flexible in their employment plans in case they fail to fill the enrollment of quotas of prospective students or they need to supplement teachers who can engage in other academic fields or research areas where new demand is expected. The most serious disadvantage of this, however, is that if secure positions cannot be provided to faculty members, there is the possibility that coherence of education and continuity of research supported by the university cannot be achieved. Therefore, the question of this presentation is as follows: Are universities aiming to give first priority to management, or are they trying to prioritize educational and research rather than management? To answer this question, the author examined the number of job offerings for college foreign language teachers posted on the JREC-IN (Japan Research Career Information Network, which is run by Japan Science and Technology Agency) website from April 2012 to October 2015. The results show that there were 1,002 and 1,056 job offerings for tenured positions and fixed-term contracts respectively, suggesting that, overall, today’s Japanese universities show a tendency to give first priority to management. More detailed examinations of the data, however, show that the tendency slightly varies depending on the types of universities. National universities which are supported by the central government and state universities which are supported by local governments posted more job offerings for tenured positions than for fixed-term contracts: national universities posted 285 and 257 job offerings for tenured positions and fixed-term contracts respectively, and state universities posted 106 and 86 job offerings for tenured positions and fixed-term contracts respectively. Yet the difference in number between the two types of employment status at national and state universities is marginal. As for private universities, they posted 713 job offerings for fixed-term contracts and 616 offerings for tenured positions. Moreover, 73% of the fixed-term contracts were offered for low rank positions including associate professors, lectures, and so forth. Generally speaking, those positions are offered to younger teachers. Therefore, this result indicates that private universities attempt to cut their budgets yet expect the same educational effect by hiring younger teachers. Although the results have shown that there are some differences in personal strategies among the three types of universities, the author argues that all three types of universities may lose important human resources that will take a pivotal role at their universities in the future unless they urgently review their employment strategies.

Keywords: higher education, management, employment status, foreign language education

Procedia PDF Downloads 115

Authors: Ali Benali Djouher Leila

Abstract:

Labiovelarization of velar consonants and labials is a very widespread phenomenon. It is attested in all the major northern Berber dialects. Only the Tuareg is totally unaware of it. But, even within the large Berber-speaking regions of the north, it is very unstable: it may be completely absent in certain dialects (such as the Bougie region in Kabylie), and its extension and frequency can vary appreciably between the dialects which know it. Some dialects of Great Kabylia or the Chleuh domain, for example, "labiovélarize" more than others from the same region. Thus, in Great Kabylia, the adjective "large" will be pronounced: amqqwran with the At Yiraten and amqqran with the At Yanni, a few kilometers away. One of the problems with them is deciding whether it is one or two phonemes. All the criteria used by linguists in this kind of case lead to the conclusion that they are unique phonemes (a phoneme and not a succession of two phonemes, / k + w /, for example). The phonetic and phonological criteria are moreover clearly confirmed by the morphological data since, in the system of verbal alternations, these complex segments are treated as single phonemes: agree, "to draw, to fetch water," akwer, "to fly," have exactly the same morphology as as "jealous," arem" taste," Ames, "dirty" or afeg, "steal" ... verbs with two radical consonants (type aCC). At the level of notation, both scientific and usual, it is, therefore, necessary to represent the labiovélarized by a single letter, possibly accompanied by a diacritic. In fact, actual practices are diverse. - The scientific representation of type does not seem adequate for current use because its realization is easy only on a microcomputer. The Berber Documentation File used a small ° (of n °) above the writing line: k °, g ° ... which has the advantage of being easy to achieve since it is part of general typographical conventions in Latin script and that it is present on a typewriter keyboard. Mouloud Mammeri, then the Berber Study Group of Vincennes (Tisuraf review), and a majority of Kabyle practitioners over the last twenty years have used the succession "consonant +" semi-vowel / w / "(CW) on the same line of writing; for all the reasons explained previously, this practice is not a good solution and should be abandoned, especially as it particularizes Kabyle in the Berber ensemble. In this study, we were interested in two velar consonants, / g / and / k /, labiovellarized: / gw / and the / kw / (we adopted the addition of the "w") for the representation for ease of writing in graphical mode. It is a question of trying to characterize these four consonants in order to see if they have different places of articulation and if they are distinct (if these velars are distinct from their labiovellarized counterpart). This characterization is done using locus equations.

Keywords: berber consonants;, labiovelarization, locus equations, acoustical caracterization, kabylian dialect, algerian language

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Authors: Mauricio Quintero Angel, Alexander Pereira, Selene Alarcón

Abstract:

One of the elements of greatest importance in agricultural production is the harvesting; an activity associated to different occupational health risks such as harvesting in high altitudes, the transport of heavy materials and the application of excessive muscle strain that leads to muscular-bone disorders. Therefore, there is an urgent necessity to improve and validate interventions to reduce exposition and risk to harvesters. This article has the objective of describing the co-development under the ergonomic analysis framework of an assisted manual harvesting tool for peach palm oriented to reduce the risk of death and accidents as it avoid the harvest in heights. The peach palm is a palm tree that is cultivated in Colombia, Perú, Brasil, Costa Rica, among others and that reaches heights of over 20 m, with stipes covered with spines. The fruits are drupes of variable size. For the harvesting of peach palm, in Colombia farmers use the “Marota” or “Climber”, a tool in a closed X shape built in wood, that has two supports adjusted at the stipe, that elevate alternately until reaching a point high enough to grab the bunch that is brought down using a rope. An activity of high risk since it is done at a high altitude without any type of protection and safety measures. The Marota is alternated with a rod, which as variable height between 5 and 12 Meters with a harness system at one end to hold the bunch that is lowered with the whole system (bamboo bunch). The rod is used from the ground or from the Marota in height. As an alternative to traditional tools, the Bajachonta was co-developed with farmers, a tool that employs a traditional bamboo hook system with modifications, to be able to hold it with a rope that passes through a pulley. Once the bunch is hitched, the hook system is detached and this stays attached to the peduncle of the palm tree, afterwards through a pulling force being exerted towards the ground by tensioning the rope, the bunch comes loose to be taken down using a rope and the pulley system to the ground, reducing the risk and efforts in the operation. The bajachonta was evaluated in tree productive zones of Colombia, with innovative farmers, were the adoption is highly probable, with some modifications to improve its efficiency and effectiveness, keeping in mind that the farmers perceive in it an advantage in the reduction of death and accidents by not having to harvest in heights.

Keywords: assisted harvesting, ergonomics, harvesting in high altitudes, participative design, peach palm

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