Search results for: visible light sources
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8152

Search results for: visible light sources

502 Influence of Mandrel’s Surface on the Properties of Joints Produced by Magnetic Pulse Welding

Authors: Ines Oliveira, Ana Reis

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Magnetic Pulse Welding (MPW) is a cold solid-state welding process, accomplished by the electromagnetically driven, high-speed and low-angle impact between two metallic surfaces. It has the same working principle of Explosive Welding (EXW), i.e. is based on the collision of two parts at high impact speed, in this case, propelled by electromagnetic force. Under proper conditions, i.e., flyer velocity and collision point angle, a permanent metallurgical bond can be achieved between widely dissimilar metals. MPW has been considered a promising alternative to the conventional welding processes and advantageous when compared to other impact processes. Nevertheless, MPW current applications are mostly academic. Despite the existing knowledge, the lack of consensus regarding several aspects of the process calls for further investigation. As a result, the mechanical resistance, morphology and structure of the weld interface in MPW of Al/Cu dissimilar pair were investigated. The effect of process parameters, namely gap, standoff distance and energy, were studied. It was shown that welding only takes place if the process parameters are within an optimal range. Additionally, the formation of intermetallic phases cannot be completely avoided in the weld of Al/Cu dissimilar pair by MPW. Depending on the process parameters, the intermetallic compounds can appear as continuous layer or small pockets. The thickness and the composition of the intermetallic layer depend on the processing parameters. Different intermetallic phases can be identified, meaning that different temperature-time regimes can occur during the process. It is also found that lower pulse energies are preferred. The relationship between energy increase and melting is possibly related to multiple sources of heating. Higher values of pulse energy are associated with higher induced currents in the part, meaning that more Joule heating will be generated. In addition, more energy means higher flyer velocity, the air existing in the gap between the parts to be welded is expelled, and this aerodynamic drag (fluid friction) is proportional to the square of the velocity, further contributing to the generation of heat. As the kinetic energy also increases with the square of velocity, the dissipation of this energy through plastic work and jet generation will also contribute to an increase in temperature. To reduce intermetallic phases, porosity, and melt pockets, pulse energy should be minimized. The bond formation is affected not only by the gap, standoff distance, and energy but also by the mandrel’s surface conditions. No correlation was clearly identified between surface roughness/scratch orientation and joint strength. Nevertheless, the aspect of the interface (thickness of the intermetallic layer, porosity, presence of macro/microcracks) is clearly affected by the surface topology. Welding was not established on oil contaminated surfaces, meaning that the jet action is not enough to completely clean the surface.

Keywords: bonding mechanisms, impact welding, intermetallic compounds, magnetic pulse welding, wave formation

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501 An Exploratory Study of the Ghanaian Music Industry: Its Impacts on the Economy and Society

Authors: Ralph Nyadu-Addo, Francis Matambalya, Utz Dornberger

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The global music industry is a multi-billion dollar sector. The potential of Africa’s music industry is widely recognised in the socio-economic development milieu. It has impacted positively on several sectors including most especially the tourism, media and information, communication technology (ICT) among others. It is becoming increasingly clear that even in Africa (as demonstrated in Nigeria) that in addition to its intrinsic value, the sector has significant economic returns. UNCTAD observed, the creative industries offer some of the best prospects for high growth in least developed countries. The statistics from Africa may be far lower than similar sectors in developed countries but it goes to give further credence to several UNCTAD publications which say the creative industry is under researched and its potential under-estimated but holds the key to its rapid development The emerging creative economy (music in particular) has become a leading component of economic growth, employment, trade, innovation, and social cohesion in many countries. In line with these developments, the Ghana government recognizes the potential that the Creative Industries have to shape and reinforce Ghana’s economic growth. Creative sectors, particularly music, tend to rely less on sophisticated infrastructure or capital-intensive investment. Potential is particularly abundant in Africa, where musical creativity is rich, diverse, well-loved, and constantly evolving while drawing on strong traditions. The development of a popular music industry thus represents low-hanging fruit for most African economies says the World Bank. As we shift towards economic diversification using the creative industry, value is increasingly created at the intersection of arts, business and technology. Cultural and creative entrepreneurs are leading this trend. It is one of the areas where value is captured within the country as emerging trends have shown in Nigeria and Ghana among others. Yet, evidence shows that the potential of the cultural and creative sectors remains largely untapped. Furthermore, its socio-economic impact remains under-researched in many developing countries and its dynamics unknown. Despite its huge influence on music repertoire across the globe, most countries in Africa have not historically been significant markets for the international music industry. Today, that is beginning to change. Generally, reliable and adequate literature about music in the sub-region is difficult to obtain. The growing interests in academia and business cycles about a reliable data on the growing music industry in developing countries have called for an urgent need to undertake this research. Research questions: i. Who are the major stakeholders in the music value chain in Ghana? ii. How much of value is captured domestically iii. What is the economic impact of the Ghanaian music industry iv. How has the advent of ICT (internet) impacted on the music landscape? Research sources will be mainly through interviews of major stakeholders, baseline study of the industry by KPMG and content analysis of related newspapers and magazines.

Keywords: economic impact, information communications technology (ICT), music-industry, value chain

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500 Islam in Nation Building: Case Studies of Kazakhstan and Kyrgyzstan

Authors: Etibar Guliyev, Durdana Jafarli

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The breakdown of the Soviet Union in the early 1990s and the 9/11 attacks resulted in the global changes created a totally new geopolitical situation for the Muslim populated republics of the former Soviet Union. Located between great powers such as China and Russia, as well as theocratic states like Iran and Afghanistan, the newly independent Central Asian states were facing a dilemma to choose a new politico-ideological course for development. Policies dubbed Perestroyka and Glasnost leading to the collapse of the world’s once superpower brought about a considerable rise in the national and religious self-consciousness of the Muslim population of the USSR where the religion was prohibited under the strict communist rule. Moreover, the religious movements prohibited during the Soviet era acted as a part of national straggle to gain their freedom from Moscow. The policies adopted by the Central Asian countries to manage the religious revival and extremism in their countries vary dramatically from each other. As Kazakhstan and Kyrgyzstan are located between Russia and China and hosting a considerable number of the Russian population, these countries treated Islamic revival more tolerantly trying benefit from it in the nation-building process. The importance of the topic could be explained with the fact that it investigates an alternative way of management of religious activities and movements. The recent developments in the Middle East, Syria and Iraq in particular, and the fact that hundreds of fighters from the Central Asian republics joined the ISIL terrorist organization once again highlights the implications of the proper regulation of religious activities not only for domestic, but also for regional and global politics. The paper is based on multiple research methods. The process trace method was exploited to better understand the Russification and anti-religious policies to which the Central Asian countries were subject during the Soviet era. The comparative analyse method was also used to better understand the common and distinct features of the politics of religion of Kazakhstan and Kyrgyzstan and the rest of the Central Asian countries. Various legislation acts, as well as secondary sources were investigated to this end. Mostly constructivist approach and a theory suggesting that religion supports national identity when there is a third cohesion that threatens both and when elements of national identity are weak. Preliminary findings suggest that in line with policies aimed at gradual reduction of Russian influence, as well as in the face of ever-increasing migration from China, the mentioned countries incorporated some Islamic elements into domestic policies as a part and parcel of national culture. Kazakhstan and Kyrgyzstan did not suppress religious activities, which was case in neighboring states, but allowed in a controlled way Islamic movements to have a relatively freedom of action which in turn led to the less violent religious extremism further boosting national identity.

Keywords: identity, Islam, nationalism, terrorism

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499 A Supply Chain Risk Management Model Based on Both Qualitative and Quantitative Approaches

Authors: Henry Lau, Dilupa Nakandala, Li Zhao

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In today’s business, it is well-recognized that risk is an important factor that needs to be taken into consideration before a decision is made. Studies indicate that both the number of risks faced by organizations and their potential consequences are growing. Supply chain risk management has become one of the major concerns for practitioners and researchers. Supply chain leaders and scholars are now focusing on the importance of managing supply chain risk. In order to meet the challenge of managing and mitigating supply chain risk (SCR), we must first identify the different dimensions of SCR and assess its relevant probability and severity. SCR has been classified in many different ways, and there are no consistently accepted dimensions of SCRs and several different classifications are reported in the literature. Basically, supply chain risks can be classified into two dimensions namely disruption risk and operational risk. Disruption risks are those caused by events such as bankruptcy, natural disasters and terrorist attack. Operational risks are related to supply and demand coordination and uncertainty, such as uncertain demand and uncertain supply. Disruption risks are rare but severe and hard to manage, while operational risk can be reduced through effective SCM activities. Other SCRs include supply risk, process risk, demand risk and technology risk. In fact, the disorganized classification of SCR has created confusion for SCR scholars. Moreover, practitioners need to identify and assess SCR. As such, it is important to have an overarching framework tying all these SCR dimensions together for two reasons. First, it helps researchers use these terms for communication of ideas based on the same concept. Second, a shared understanding of the SCR dimensions will support the researchers to focus on the more important research objective: operationalization of SCR, which is very important for assessing SCR. In general, fresh food supply chain is subject to certain level of risks, such as supply risk (low quality, delivery failure, hot weather etc.) and demand risk (season food imbalance, new competitors). Effective strategies to mitigate fresh food supply chain risk are required to enhance operations. Before implementing effective mitigation strategies, we need to identify the risk sources and evaluate the risk level. However, assessing the supply chain risk is not an easy matter, and existing research mainly use qualitative method, such as risk assessment matrix. To address the relevant issues, this paper aims to analyze the risk factor of the fresh food supply chain using an approach comprising both fuzzy logic and hierarchical holographic modeling techniques. This novel approach is able to take advantage the benefits of both of these well-known techniques and at the same time offset their drawbacks in certain aspects. In order to develop this integrated approach, substantial research work is needed to effectively combine these two techniques in a seamless way, To validate the proposed integrated approach, a case study in a fresh food supply chain company was conducted to verify the feasibility of its functionality in a real environment.

Keywords: fresh food supply chain, fuzzy logic, hierarchical holographic modelling, operationalization, supply chain risk

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498 Predicting Provider Service Time in Outpatient Clinics Using Artificial Intelligence-Based Models

Authors: Haya Salah, Srinivas Sharan

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Healthcare facilities use appointment systems to schedule their appointments and to manage access to their medical services. With the growing demand for outpatient care, it is now imperative to manage physician's time effectively. However, high variation in consultation duration affects the clinical scheduler's ability to estimate the appointment duration and allocate provider time appropriately. Underestimating consultation times can lead to physician's burnout, misdiagnosis, and patient dissatisfaction. On the other hand, appointment durations that are longer than required lead to doctor idle time and fewer patient visits. Therefore, a good estimation of consultation duration has the potential to improve timely access to care, resource utilization, quality of care, and patient satisfaction. Although the literature on factors influencing consultation length abound, little work has done to predict it using based data-driven approaches. Therefore, this study aims to predict consultation duration using supervised machine learning algorithms (ML), which predicts an outcome variable (e.g., consultation) based on potential features that influence the outcome. In particular, ML algorithms learn from a historical dataset without explicitly being programmed and uncover the relationship between the features and outcome variable. A subset of the data used in this study has been obtained from the electronic medical records (EMR) of four different outpatient clinics located in central Pennsylvania, USA. Also, publicly available information on doctor's characteristics such as gender and experience has been extracted from online sources. This research develops three popular ML algorithms (deep learning, random forest, gradient boosting machine) to predict the treatment time required for a patient and conducts a comparative analysis of these algorithms with respect to predictive performance. The findings of this study indicate that ML algorithms have the potential to predict the provider service time with superior accuracy. While the current approach of experience-based appointment duration estimation adopted by the clinic resulted in a mean absolute percentage error of 25.8%, the Deep learning algorithm developed in this study yielded the best performance with a MAPE of 12.24%, followed by gradient boosting machine (13.26%) and random forests (14.71%). Besides, this research also identified the critical variables affecting consultation duration to be patient type (new vs. established), doctor's experience, zip code, appointment day, and doctor's specialty. Moreover, several practical insights are obtained based on the comparative analysis of the ML algorithms. The machine learning approach presented in this study can serve as a decision support tool and could be integrated into the appointment system for effectively managing patient scheduling.

Keywords: clinical decision support system, machine learning algorithms, patient scheduling, prediction models, provider service time

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497 Traditional Rainwater Harvesting Systems: A Sustainable Solution for Non-Urban Populations in the Mediterranean

Authors: S. Fares, K. Mellakh, A. Hmouri

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The StorMer project aims to set up a network of researchers to study traditional hydraulic rainwater harvesting systems in the Mediterranean basin, a region suffering from the major impacts of climate change and limited natural water resources. The arid and semi-arid Mediterranean basin has a long history of pioneering water management practices. The region has developed various ancient traditional water management systems, such as cisterns and qanats, to sustainably manage water resources under historical conditions of scarcity. Therefore, the StorMer project brings together Spain, France, Italy, Greece, Jordan and Morocco to explore traditional rainwater harvesting practices and systems in the Mediterranean region and to develop accurate modeling to simulate the performance and sustainability of these technologies under present-day climatic conditions. The ultimate goal of this project was to resuscitate and valorize these practices in the context of contemporary challenges. This project was intended to establish a Mediterranean network to serve as a basis for a more ambitious project. The ultimate objective was to analyze traditional hydraulic systems and create a prototype hydraulic ecosystem using a coupled environmental approach and traditional and ancient know-how, with the aim of reinterpreting them in the light of current techniques. The combination of ‘traditional’ and ‘modern knowledge/techniques’ is expected to lead to proposals for innovative hydraulic systems. The pandemic initially slowed our progress, but in the end it forced us to carry out the fieldwork in Morocco and Saudi Arabia, and so restart the project. With the participation of colleagues from chronologically distant fields (archaeology, sociology), we are now prepared to share our observations and propose the next steps. This interdisciplinary approach should give us a global vision of the project's objectives and challenges. A diachronic approach is needed to tackle the question of the long-term adaptation of societies in a Mediterranean context that has experienced several periods of water stress. The next stage of the StorMer project is the implementation of pilots in non-urbanized regions. These pilots will test the implementation of traditional systems and will be maintained and evaluated in terms of effectiveness, cost and acceptance. Based on these experiences, larger projects will be proposed and could provide information for regional water management policies. One of the most important lessons learned from this project is the highly social nature of managing traditional rainwater harvesting systems. Unlike modern, centralized water infrastructures, these systems often require the involvement of communities, which assume ownership and responsibility for them. This kind of community engagement leads to greater maintenance and, therefore, sustainability of the systems. Knowledge of the socio-cultural characteristics of these communities means that the systems can be adapted to the needs of each location, ensuring greater acceptance and efficiency.

Keywords: oasis, rainfall harvesting, arid regions, Mediterranean

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496 Residents' Incomes in Local Government Unit as the Major Determinant of Local Budget Transparency in Croatia: Panel Data Analysis

Authors: Katarina Ott, Velibor Mačkić, Mihaela Bronić, Branko Stanić

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The determinants of national budget transparency have been widely discussed in the literature, while research on determinants of local budget transparency are scarce and empirically inconclusive, particularly in the new, fiscally centralised, EU member states. To fill the gap, we combine two strands of the literature: that concerned with public administration and public finance, shedding light on the economic and financial determinants of local budget transparency, and that on the political economy of transparency (principal agent theory), covering the relationships among politicians and between politicians and voters. Our main hypothesis states that variables describing residents’ capacity have a greater impact on local budget transparency than variables indicating the institutional capacity of local government units (LGUs). Additional subhypotheses test the impact of each variable analysed on local budget transparency. We address the determinants of local budget transparency in Croatia, measured by the number of key local budget documents published on the LGUs’ websites. By using a data set of 128 cities and 428 municipalities over the 2015-2017 period and by applying panel data analysis based on Poisson and negative binomial distribution, we test our main hypothesis and sub-hypotheses empirically. We measure different characteristics of institutional and residents’ capacity for each LGU. Age, education and ideology of the mayor/municipality head, political competition indicators, number of employees, current budget revenues and direct debt per capita have been used as a measure of the institutional capacity of LGU. Residents’ capacity in each LGU has been measured through the numbers of citizens and their average age as well as by average income per capita. The most important determinant of local budget transparency is average residents' income per capita at both city and municipality level. The results are in line with most previous research results in fiscally decentralised countries. In the context of a fiscally centralised country with numerous small LGUs, most of whom have low administrative and fiscal capacity, this has a theoretical rationale in the legitimacy and principal-agent theory (opportunistic motives of the incumbent). The result is robust and significant, but because of the various other results that change between city and municipality levels (e.g. ideology and political competition), there is a need for further research (both on identifying other determinates and/or methods of analysis). Since in Croatia the fiscal capacity of a LGU depends heavily on the income of its residents, units with higher per capita incomes in many cases have also higher budget revenues allowing them to engage more employees and resources. In addition, residents’ incomes might be also positively associated with local budget transparency because of higher citizen demand for such transparency. Residents with higher incomes expect more public services and have more access to and experience in using the Internet, and will thus typically demand more budget information on the LGUs’ websites.

Keywords: budget transparency, count data, Croatia, local government, political economy

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495 Environmental Impact of a New-Build Educational Building in England: Life-Cycle Assessment as a Method to Calculate Whole Life Carbon Emissions

Authors: Monkiz Khasreen

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In the context of the global trend towards reducing new buildings carbon footprint, the design team is required to make early decisions that have a major influence on embodied and operational carbon. Sustainability strategies should be clear during early stages of building design process, as changes made later can be extremely costly. Life-Cycle Assessment (LCA) could be used as the vehicle to carry other tools and processes towards achieving the requested improvement. Although LCA is the ‘golden standard’ to evaluate buildings from 'cradle to grave', lack of details available on the concept design makes LCA very difficult, if not impossible, to be used as an estimation tool at early stages. Issues related to transparency and accessibility of information in the building industry are affecting the credibility of LCA studies. A verified database derived from LCA case studies is required to be accessible to researchers, design professionals, and decision makers in order to offer guidance on specific areas of significant impact. This database could be the build-up of data from multiple sources within a pool of research held in this context. One of the most important factors that affects the reliability of such data is the temporal factor as building materials, components, and systems are rapidly changing with the advancement of technology making production more efficient and less environmentally harmful. Recent LCA studies on different building functions, types, and structures are always needed to update databases derived from research and to form case bases for comparison studies. There is also a need to make these studies transparent and accessible to designers. The work in this paper sets out to address this need. This paper also presents life-cycle case study of a new-build educational building in England. The building utilised very current construction methods and technologies and is rated as BREEAM excellent. Carbon emissions of different life-cycle stages and different building materials and components were modelled. Scenario and sensitivity analyses were used to estimate the future of new educational buildings in England. The study attempts to form an indicator during the early design stages of similar buildings. Carbon dioxide emissions of this case study building, when normalised according to floor area, lie towards the lower end of the range of worldwide data reported in the literature. Sensitivity analysis shows that life cycle assessment results are highly sensitive to future assumptions made at the design stage, such as future changes in electricity generation structure over time, refurbishment processes and recycling. The analyses also prove that large savings in carbon dioxide emissions can result from very small changes at the design stage.

Keywords: architecture, building, carbon dioxide, construction, educational buildings, England, environmental impact, life-cycle assessment

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494 An Investigation into Why Very Few Small Start-Ups Business Survive for Longer Than Three Years: An Explanatory Study in the Context of Saudi Arabia

Authors: Motaz Alsolaim

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Nowadays, the challenges of running a start-up can be very complex and are perhaps more difficult than at any other time in the past. Changes in technology, manufacturing innovation, and product development, combined with intense competition and market regulations are factors that have put pressure on classic ways of managing firms, thereby forcing change. As a result, the rate of closure, exit or discontinuation of start-ups and young businesses is very high. Despite the essential role of small firms in an economy, they still tend to face obstacles that exert a negative influence on their performance and rate of survival. In fact, it is not easy to determine with any certainty the reasons why small firms fail. For this reason, failure itself is not clearly defined, and its exact causes are hard to diagnose. In this current study, therefore, the barriers to survival will be covered more broadly, especially personal/entrepreneurial, enterprise and environmental factors with regard to various possible reasons for this failure, in order to determine the best solutions and make appropriate recommendations. Methodology: It could be argued that mixed methods might help to improve entrepreneurship research addressing challenges emphasis in previous studies and to achieve the triangulation. Calls for the combined use of quantitative and qualitative research were also made in the entrepreneurship field since entrepreneurship is a multi-faceted area of research. Therefore, explanatory sequential mixed method was used, using questionnaire online survey for entrepreneurs, followed by semi-structure interview. Collecting over 750 surveys and accepting 296 valid surveys, after that 13 interviews from government official seniors, businessmen successful entrepreneurs, and non-successful entrepreneurs. Findings: The first phase findings ( quantitative) shows the obstacles to survive; starting from the personal/ entrepreneurial factors such as; past work experience, lack of skills and interest, are positive factors, while; gender, age and education level of the owner are negative factors. Internal factors such as lack of marketing research and weak business planning are positive. The environmental factors; in economic perspectives; difficulty to find labors, in socio-cultural perspectives; Social restriction and traditions found to be a negative factors. In other hand, from the political perspective; cost of compliance and insufficient government plans found to be a positive factors for small business failure. From infrastructure perspective; lack of skills labor, high level of bureaucracy and lack of information are positive factors. Conclusion: This paper serves to enrich the understanding of failure factors in MENA region more precisely in SA, by minimizing the probability of failure in small-micro entrepreneurial start-up in SA, in the light of the Saudi government’s Vision 2030 plan.

Keywords: small business barriers, start-up business, entrepreneurship, Saudi Arabia

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493 Potency of Some Dietary Acidifiers on Productive Performance and Controlling Salmonella enteritidis in Broilers

Authors: Mohamed M. Zaki, Maha M. Hady

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Salmonella spp. have been categorized as the world’s biggest threats to human health and poultry products are mostly incriminated sources. In Egypt, it was found that S. enteritidis and S. typhimurium are the most prevalent ones in poultry farms. It is recommended to eliminate salmonella from living bird by competing for salmonella contamination in feed in order to establish a healthy gut. The Feed acidifiers are the group of feed additives containing low-molecular-weight organic acids and/ or their salts which act as performance promoters by lowering the pH in the gut, optimizes digestion and inhibit bacterial growth. The inclusion of organic acid in pure form nonetheless effective in feed, yet, it is difficult to handle in feed mills as it is corrosive and produce more losses during pelleting process. The current study aimed at to evaluate the impact of incorporation of sodium diformate (SDF) and a commercial acidifier, CA (a mixture of butyric and propionic acids and their ammonium salts) at 0.4% dietary levels on broilers performance and the control S. enteritidis infection. Two hundreds and seventy unsexed cobb chickens were allotted in one of three treatments (90/ group) which were, the control (no acidifier, C- &C+), the 0.4% SDF (SDF- & SDF +) and the 0.4% CA (CA- & CA +) dietary levels for 35 days. Before the allocation of the groups, ten extra birds and a diet sample were bacteriologically examined to ensure negative contamination with salmonella. The birds were raised on deep-litter separated pens and had free access to feed and water all the time. The experimentally formulated diets were kept at 40C. After 24h access to the different dietary treatments, all the birds in the positive groups (n=15/ replicate) were inoculated intra-crop with 0.2 ml of 24 h broth culture of S. entertidis containing 1X 107 organisms while the negative-treated groups were inoculated with the same amount of the negative broth and second inoculation was done at 22 d of age. Colocal swabs were collected individually from all birds 2 h pre-inoculation to assure the absence of salmonella, then 1, 3, 5, 7, 21 days post-inoculation to recover salmonella. Performance parameter (body weight gain and feed efficiency) were calculated. Mortalities were recorded and reisolation of the salmonella was adopted to ensure it was the inoculated ones. The results revealed that the dietary acidification with sodium diformate significantly improved broilers performance and tends to produce heavier birds as compared to the negative control and CA groups. Moreover, the dietary inclusion of both acidifiers at level of 0.4% was able to eliminate mortalities completely at the relevant inoculation time. Regarding the shedding of S. enteritidius in positive groups, the SDF treatment resulted in significant (p<0.05) cessation of the shedding at 3 days post-inoculation compared to 7 days post-inoculation for the CA-group. In conclusion, sodium diformate at 0.4% dietary level in broiler diets has a valuable effect not only on broilers performance but also by eliminating S. enteritidis the main source of salmonella contamination in poultry farms which is feed.

Keywords: acidifier, broilers, Salmonalla spp, sodium diformate

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492 Graphene Supported Nano Cerium Oxides Hybrid as an Electrocatalyst for Oxygen Reduction Reactions

Authors: Siba Soren, Purnendu Parhi

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Today, the world is facing a severe challenge due to depletion of traditional fossil fuels. Scientists across the globe are working for a solution that involves a dramatic shift to practical and environmentally sustainable energy sources. High-capacity energy systems, such as metal-air batteries, fuel cells, are highly desirable to meet the urgent requirement of sustainable energies. Among the fuel cells, Direct methanol fuel cells (DMFCs) are recognized as an ideal power source for mobile applications and have received considerable attention in recent past. In this advanced electrochemical energy conversion technologies, Oxygen Reduction Reaction (ORR) is of utmost importance. However, the poor kinetics of cathodic ORR in DMFCs significantly hampers their possibilities of commercialization. The oxygen is reduced in alkaline medium either through a 4-electron (equation i) or a 2-electron (equation ii) reduction pathway at the cathode ((i) O₂ + 2H₂O + 4e⁻ → 4OH⁻, (ii) O₂ + H₂O + 2e⁻ → OH⁻ + HO₂⁻ ). Due to sluggish ORR kinetics the ability to control the reduction of molecular oxygen electrocatalytically is still limited. The electrocatalytic ORR starts with adsorption of O₂ on the electrode surface followed by O–O bond activation/cleavage and oxide removal. The reaction further involves transfer of 4 electrons and 4 protons. The sluggish kinetics of ORR, on the one hand, demands high loading of precious metal-containing catalysts (e.g., Pt), which unfavorably increases the cost of these electrochemical energy conversion devices. Therefore, synthesis of active electrocatalyst with an increase in ORR performance is need of the hour. In the recent literature, there are many reports on transition metal oxide (TMO) based ORR catalysts for their high activity TMOs are also having drawbacks like low electrical conductivity, which seriously affects the electron transfer process during ORR. It was found that 2D graphene layer is having high electrical conductivity, large surface area, and excellent chemical stability, appeared to be an ultimate choice as support material to enhance the catalytic performance of bare metal oxide. g-C₃N₄ is also another candidate that has been used by the researcher for improving the ORR performance of metal oxides. This material provides more active reaction sites than other N containing carbon materials. Rare earth oxide like CeO₂ is also a good candidate for studying the ORR activity as the metal oxide not only possess unique electronic properties but also possess catalytically active sites. Here we will discuss the ORR performance (in alkaline medium) of N-rGO/C₃N₄ supported nano Cerium Oxides hybrid synthesized by microwave assisted Solvothermal method. These materials exhibit superior electrochemical stability and methanol tolerance capability to that of commercial Pt/C.

Keywords: oxygen reduction reaction, electrocatalyst, cerium oxide, graphene

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491 Exploring the Impact of Eye Movement Desensitization and Reprocessing (EMDR) And Mindfulness for Processing Trauma and Facilitating Healing During Ayahuasca Ceremonies

Authors: J. Hash, J. Converse, L. Gibson

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Plant medicines are of growing interest for addressing mental health concerns. Ayahuasca, a traditional plant-based medicine, has established itself as a powerful way of processing trauma and precipitating healing and mood stabilization. Eye Movement Desensitization and Reprocessing (EMDR) is another treatment modality that aids in the rapid processing and resolution of trauma. We investigated group EMDR therapy, G-TEP, as a preparatory practice before Ayahuasca ceremonies to determine if the combination of these modalities supports participants in their journeys of letting go of past experiences negatively impacting mental health, thereby accentuating the healing of the plant medicine. We surveyed 96 participants (51 experimental G-TEP, 45 control grounding prior to their ceremony; age M=38.6, SD=9.1; F=57, M=34; white=39, Hispanic/Latinx=23, multiracial=11, Asian/Pacific Islander=10, other=7) in a pre-post, mixed methods design. Participants were surveyed for demographic characteristics, symptoms of PTSD and cPTSD (International Trauma Questionnaire (ITQ), depression (Beck Depression Inventory, BDI), and stress (Perceived Stress Scale, PSS) before the ceremony and at the end of the ceremony weekend. Open-ended questions also inquired about their expectations of the ceremony and results at the end. No baseline differences existed between the control and experimental participants. Overall, participants reported a decrease in meeting the threshold for PTSD symptoms (p<0.01); surprisingly, the control group reported significantly fewer thresholds met for symptoms of affective dysregulation, 2(1)=6.776, p<.01, negative self-concept, 2 (1)=7.122, p<.01, and disturbance in relationships, 2 (1)=9.804, p<.01, on subscales of the ITQ as compared to the experimental group. All participants also experienced a significant decrease in scores on the BDI, t(94)=8.995, p<.001, and PSS, t(91)=6.892, p<.001. Similar to patterns of PTSD symptoms, the control group reported significantly lower scores on the BDI, t(65.115)=-2.587, p<.01, and a trend toward lower PSS, t(90)=-1.775, p=.079 (this was significant with a one-sided test at p<.05), compared to the experimental group following the ceremony. Qualitative interviews among participants revealed a potential explanation for these relatively higher levels of depression and stress in the experimental group following the ceremony. Many participants reported needing more time to process their experience to gain an understanding of the effects of the Ayahuasca medicine. Others reported a sense of hopefulness and understanding of the sources of their trauma and the necessary steps to heal moving forward. This suggests increased introspection and openness to processing trauma, therefore making them more receptive to their emotions. The integration process of an Ayahuasca ceremony is a week- to months-long process that was not accessible in this stage of research, yet it is an integral process to understanding the full effects of the Ayahuasca medicine following the closure of a ceremony. Our future research aims to assess participants weeks into their integration process to determine the effectiveness of EMDR, and if the higher levels of depression and stress indicate the initial reaction to greater awareness of trauma and receptivity to healing.

Keywords: ayahuasca, EMDR, PTSD, mental health

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490 Adopting a New Policy in Maritime Law for Protecting Ship Mortgagees Against Maritime Liens

Authors: Mojtaba Eshraghi Arani

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Ship financing is the vital element in the development of shipping industry because while the ship constitutes the owners’ main asset, she is considered a reliable security in the financiers’ viewpoint as well. However, it is most probable that a financier who has accepted a ship as security will face many creditors who are privileged and rank before him for collecting, out of the ship, the money that they are owed. In fact, according to the current rule of maritime law, which was established by “Convention Internationale pour l’Unification de Certaines Règles Relatives aux Privilèges et Hypothèques Maritimes, Brussels, 10 April 1926”, the mortgages, hypotheques, and other charges on vessels rank after several secured claims referred to as “maritime liens”. Such maritime liens are an exhaustive list of claims including but not limited to “expenses incurred in the common interest of the creditors to preserve the vessel or to procure its sale and the distribution of the proceeds of sale”, “tonnage dues, light or harbour dues, and other public taxes and charges of the same character”, “claims arising out of the contract of engagement of the master, crew and other persons hired on board”, “remuneration for assistance and salvage”, “the contribution of the vessel in general average”, “indemnities for collision or other damage caused to works forming part of harbours, docks, etc,” “indemnities for personal injury to passengers or crew or for loss of or damage to cargo”, “claims resulting form contracts entered into or acts done by the master”. The same rule survived with only some minor change in the categories of maritime liens in the substitute conventions 1967 and 1993. The status que in maritime law have always been considered as a major obstacle to the development of shipping market and has inevitably led to increase in the interest rates and other related costs of ship financing. It seems that the national and international policy makers have yet to change their mind being worried about the deviation from the old marine traditions. However, it is crystal clear that the continuation of status que will harm, to a great extent, the shipowners and, consequently, the international merchants as a whole. It is argued in this article that the raison d'être for many categories of maritime liens cease to exist anymore, in view of which, the international community has to recognize only a minimum category of maritime liens which are created in the common interests of all creditors; to this effect, only two category of “compensation due for the salvage of ship” and “extraordinary expenses indispensable for the preservation of the ship” can be declared as taking priority over the mortgagee rights, in anology with the Geneva Convention on the International Recognition of Rights in Aircrafts (1948). A qualitative method with the concept of interpretation of data collection has been used in this manuscript. The source of the data is the analysis of international conventions and domestic laws.

Keywords: ship finance, mortgage, maritime liens, brussels convenion, geneva convention 1948

Procedia PDF Downloads 72
489 Relative Expression and Detection of MUB Adhesion Domains and Plantaricin-Like Bacteriocin among Probiotic Lactobacillus plantarum-Group Strains Isolated from Fermented Foods

Authors: Sundru Manjulata Devi, Prakash M. Halami

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The immemorial use of fermented foods from vegetables, dairy and other biological sources are of great demand in India because of their health benefits. However, the diversity of Lactobacillus plantarum group (LPG) of vegetable origin has not been revealed yet, particularly with reference to their probiotic functionalities. In the present study, the different species of probiotic Lactobacillus plantarum group (LPG) i.e., L. plantarum subsp. plantarum MTCC 5422 (from fermented cereals), L. plantarum subsp. argentoratensis FG16 (from fermented bamboo shoot) and L. paraplantarum MTCC 9483 (from fermented gundruk) (as characterized by multiplex recA PCR assay) were considered to investigate their relative expression of MUB domains of mub gene (mucin binding protein) by Real time PCR. Initially, the allelic variation in the mub gene was assessed and found to encode three different variants (Type I, II and III). All the three types had 8, 9 and 10 MUB domains respectively (as analysed by Pfam database) and were found to be responsible for adhesion of bacteria to the host intestinal epithelial cells. These domains either get inserted or deleted during speciation or evolutionary events and lead to divergence. The reverse transcriptase qPCR analysis with mubLPF1+R1 primer pair supported variation in amplicon sizes with 300, 500 and 700 bp among different LPG strains. The relative expression of these MUB domains significantly unregulated in the presence of 1% mucin in overnight grown cultures. Simultaneously, the mub gene expressed efficiently by 7 fold in the culture L. paraplantarum MTCC 9483 with 10 MUB domains. An increase in the expression levels for L. plantarum subsp. plantarum MTCC 5422 and L. plantarum subsp. argentoratensis FG16 (MCC 2974) with 9 and 8 repetitive domains was around 4 and 2 fold, respectively. The detection and expression of an integrase (int) gene in the upstream region of mub gene reveals the excision and integration of these repetitive domains. Concurrently, an in vitro adhesion assay to mucin and exclusion of pathogens (such as Listeria monocytogenes and Micrococcus leuteus) was investigated and observed that the L. paraplantarum MTCC 9483 with more adhesion domains has more ability to adhere to mucin and inhibited the growth of pathogens. The production and expression of plantaricin-like bacteriocin (plnNC8 type) in MTCC 9483 suggests the pathogen inhibition. Hence, the expression of MUB domains can act as potential biomarkers in the screening of a novel probiotic LPG strain with adherence property. The present study provides a platform for an easy, rapid, less time consuming, low-cost methodology for the detection of potential probiotic bacteria. It was known that the traditional practices followed in the preparation of fermented bamboo shoots/gundruk/cereals of Indian foods contain different kinds of neutraceuticals for functional food and novel compounds with health promoting factors. In future, a detailed study of these food products can add more nutritive value, consumption and suitable for commercialization.

Keywords: adhesion gene, fermented foods, MUB domains, probiotics

Procedia PDF Downloads 270
488 Regulation of Desaturation of Fatty Acid and Triglyceride Synthesis by Myostatin through Swine-Specific MEF2C/miR222/SCD5 Pathway

Authors: Wei Xiao, Gangzhi Cai, Xingliang Qin, Hongyan Ren, Zaidong Hua, Zhe Zhu, Hongwei Xiao, Ximin Zheng, Jie Yao, Yanzhen Bi

Abstract:

Myostatin (MSTN) is the master regulator of double muscling phenotype with overgrown muscle and decreased fatness in animals, but its action mode to regulate fat deposition remains to be elucidated. In this study a swin-specific pathway through which MSTN acts to regulate the fat deposition was deciphered. Deep sequenincing of the mRNA and miRNA of fat tissues of MSTN knockout (KO) and wildtype (WT) pigs discovered the positive correlation of myocyte enhancer factor 2C (MEF2C) and fat-inhibiting miR222 expression, and the inverse correlation of miR222 and stearoyl-CoA desaturase 5 (SCD5) expression. SCD5 is rodent-absent and expressed only in pig, sheep and cattle. Fatty acid spectrum of fat tissues revealed a lower percentage of oleoyl-CoA (18:1) and palmitoleyl CoA (16:1) in MSTN KO pigs, which are the catalyzing products of SCD5-mediated desaturation of steroyl CoA (18:0) and palmitoyl CoA (16:0). Blood metrics demonstrated a 45% decline of triglyceride (TG) content in MSTN KO pigs. In light of these observations we hypothesized that MSTN might act through MEF2C/miR222/SCD5 pathway to regulate desaturation of fatty acid as well as triglyceride synthesis in pigs. To this end, real-time PCR and Western blotting were carried out to detect the expression of the three genes stated above. These experiments showed that MEF2C expression was up-regulated by nearly 2-fold, miR222 up-regulated by nearly 3-fold and SCD5 down-regulated by nearly 50% in MSTN KO pigs. These data were consistent with the expression change in deep sequencing analysis. Dual luciferase reporter was then used to confirm the regulation of MEF2C upon the promoter of miR222. Ecotopic expression of MEF2C in preadipocyte cells enhanced miR222 expression by 3.48-fold. CHIP-PCR identified a putative binding site of MEF2C on -2077 to -2066 region of miR222 promoter. Electrophoretic mobility shift assay (EMSA) demonstrated the interaction of MEF2C and miR222 promoter in vitro. These data indicated that MEF2C transcriptionally regulates the expression of miR222. Next, the regulation of miR222 on SCD5 mRNA as well as its physiological consequences were examined. Dual luciferase reporter testing revealed the translational inhibition of miR222 upon the 3´ UTR (untranslated region) of SCD5 in preadipocyte cells. Transfection of miR222 mimics and inhibitors resulted in the down-regulation and up-regulation of SCD5 in preadipocyte cells respectively, consistent with the results from reporter testing. RNA interference of SCD5 in preadipocyte cells caused 26.2% reduction of TG, in agreement with the results of TG content in MSTN KO pigs. In summary, the results above supported the existence of a molecular pathway that MSTN signals through MEF2C/miR222/SCD5 to regulate the fat deposition in pigs. This swine-specific pathway offers potential molecular markers for the development and breeding of a new pig line with optimised fatty acid composition. This would benefit human health by decreasing the takeup of saturated fatty acid.

Keywords: fat deposition, MEF2C, miR222, myostatin, SCD5, pig

Procedia PDF Downloads 129
487 Temporal Changes Analysis (1960-2019) of a Greek Rural Landscape

Authors: Stamatia Nasiakou, Dimitrios Chouvardas, Michael Vrahnakis, Vassiliki Kleftoyanni

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Recent research in the mountainous and semi-mountainous rural landscapes of Greece shows that they have been significantly changed over the last 80 years. These changes have the form of structural modification of land cover/use patterns, with the main characteristic being the extensive expansion of dense forests and shrubs at the expense of grasslands and extensive agricultural areas. The aim of this research was to study the 60-year changes (1960-2019) of land cover/ use units in the rural landscape of Mouzaki (Karditsa Prefecture, central Greece). Relevant cartographic material such as forest land use maps, digital maps (Corine Land Cover -2018), 1960 aerial photos from Hellenic Military Geographical Service, and satellite imagery (Google Earth Pro 2014, 2016, 2017 and 2019) was collected and processed in order to study landscape evolution. ArcGIS v 10.2.2 software was used to process the cartographic material and to produce several sets of data. Main product of the analysis was a digitized photo-mosaic of the 1960 aerial photographs, a digitized photo-mosaic of recent satellite images (2014, 2016, 2017 and 2019), and diagrams and maps of temporal transformation of the rural landscape (1960 – 2019). Maps and diagrams were produced by applying photointerpretation techniques and a suitable land cover/ use classification system on the two photo-mosaics. Demographic and socioeconomic inventory data was also collected mainly from diachronic census reports of the Hellenic Statistical Authority and local sources. Data analysis of the temporal transformation of land cover/ use units showed that they are mainly located in the central and south-eastern part of the study area, which mainly includes the mountainous part of the landscape. The most significant change is the expansion of the dense forests that currently dominate the southern and eastern part of the landscape. In conclusion, the produced diagrams and maps of the land cover/ use evolution suggest that woody vegetation in the rural landscape of Mouzaki has significantly increased over the past 60 years at the expense of the open areas, especially grasslands and agricultural areas. Demographic changes, land abandonment and the transformation of traditional farming practices (e.g. agroforestry) were recognized as the main cause of the landscape change. This study is part of a broader research project entitled “Perspective of Agroforestry in Thessaly region: A research on social, environmental and economic aspects to enhance farmer participation”. The project is funded by the General Secretariat for Research and Technology (GSRT) and the Hellenic Foundation for Research and Innovation (HFRI).

Keywords: Agroforestry, Forest expansion, Land cover/ use changes, Mountainous and semi-mountainous areas

Procedia PDF Downloads 108
486 Evaluation of Different Inoculation Methods of Entomopathogenic Fungi on Their Endophytism and Pathogenicity against Chilo partellus (Swinhoe)

Authors: Mubashar Iqbal, Iqra Anjum, Muhammad Dildar Gogi, Muhammad Jalal Arif

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The present study was carried to screen out the effective entomopathogenic fungi (EPF) inoculation method in maize and to evaluate pathogenicity and oviposition-choice in C. partellus. Three entomopathogenic fungi (EPF) formulations Pacer® (Metarhizium anisopliae), Racer® (Beauveria bassiana) and Meailkil® (Verticillium lecanii) were evaluated at three concentrations (5000, 10000 and 20000 ppm) for their endophytism in maize and pathogenicity in C. partellus. The stock solution of the highest concentration (20,000 ppm) was prepared and next lower from stock solution. In the first experiment, three EPF was inoculated in maize plant by four methods, i.e., leaf-inoculation (LI), whorl-inoculation (WI), shoot-inoculation (SI) and root-inoculation (RI). Leaf-discs and stem-cutting were sampled in all four inoculation methods and placed on fungus growth media in Petri dishes. In the second experiment, pathogenicity, pupal formation, adult emergence, sex ratio, oviposition-choice, and growth index of C. partellus were calculated. The leaves and stem of the inoculated plants were given to the counted number of larvae of C. Partellus. The mortality of larvae was recorded on daily basis till the pupation. The result shows that maximum percent mortality (86.67%) was recorded at high concentration (20000ppm) of Beauveria bassiana by leaf inoculation method. For oviposition choice bioassay, the newly emerged adults were fed on diet (water, honey and yeast in 9:1:1) for 48 hours. One pair of C. Partellus were aspirated from the rearing cages and were detained in large test tube plugged with diet soaked cotton. A set of four plants for each treatment were prepared and randomized inside the large oviposition chamber. The test tubes were opened and fitted in the hole made in the wall of oviposition chamber in front of each treatment. The oviposition chamber was placed in a completely dark laboratory to eliminate the effect of light on moth’s behavior. The plants were removed from the oviposition chamber after the death of adults. The number of eggs deposited on the plant was counted. The results of 2nd experiment revealed that in all EPF and inoculation methods, the fecundity, egg fertility and growth index of C. partellus decreased with the increase in concentration being significantly higher at low concentration (5000ppm) and lower at higher concentration (20000ppm). Application of B. bassiana demonstrated that minimum fecundity (126.83), egg fertility (119.52) and growth index (15%) in C. partellus followed by M. anisopliae with fecundity (135.93), egg fertility (132.29) and growth index (17.50%) while V. lecanii show higher values of fecundity (137.37), egg fertility (1135.42) and growth index (20%). Overall leaf inoculation method showed least fecundity (123.89) with egg fertility (115.36) and growth index (14%) followed by whorl, shoot inoculation method and root inoculation method show higher values of fecundity, egg fertility and growth index.

Keywords: Beauveria bassiana, Chilo partellus, entomopathoganic, Metarhizium anisopliae, Verticillium lecanii

Procedia PDF Downloads 138
485 Adopting Data Science and Citizen Science to Explore the Development of African Indigenous Agricultural Knowledge Platform

Authors: Steven Sam, Ximena Schmidt, Hugh Dickinson, Jens Jensen

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The goal of this study is to explore the potential of data science and citizen science approaches to develop an interactive, digital, open infrastructure that pulls together African indigenous agriculture and food systems data from multiple sources, making it accessible and reusable for policy, research and practice in modern food production efforts. The World Bank has recognised that African Indigenous Knowledge (AIK) is innovative and unique among local and subsistent smallholder farmers, and it is central to sustainable food production and enhancing biodiversity and natural resources in many poor, rural societies. AIK refers to tacit knowledge held in different languages, cultures and skills passed down from generation to generation by word of mouth. AIK is a key driver of food production, preservation, and consumption for more than 80% of citizens in Africa, and can therefore assist modern efforts of reducing food insecurity and hunger. However, the documentation and dissemination of AIK remain a big challenge confronting librarians and other information professionals in Africa, and there is a risk of losing AIK owing to urban migration, modernisation, land grabbing, and the emergence of relatively small-scale commercial farming businesses. There is also a clear disconnect between the AIK and scientific knowledge and modern efforts for sustainable food production. The study combines data science and citizen science approaches through active community participation to generate and share AIK for facilitating learning and promoting knowledge that is relevant for policy intervention and sustainable food production through a curated digital platform based on FAIR principles. The study adopts key informant interviews along with participatory photo and video elicitation approach, where farmers are given digital devices (mobile phones) to record and document their every practice involving agriculture, food production, processing, and consumption by traditional means. Data collected are analysed using the UK Science and Technology Facilities Council’s proven methodology of citizen science (Zooniverse) and data science. Outcomes are presented in participatory stakeholder workshops, where the researchers outline plans for creating the platform and developing the knowledge sharing standard framework and copyrights agreement. Overall, the study shows that learning from AIK, by investigating what local communities know and have, can improve understanding of food production and consumption, in particular in times of stress or shocks affecting the food systems and communities. Thus, the platform can be useful for local populations, research, and policy-makers, and it could lead to transformative innovation in the food system, creating a fundamental shift in the way the North supports sustainable, modern food production efforts in Africa.

Keywords: Africa indigenous agriculture knowledge, citizen science, data science, sustainable food production, traditional food system

Procedia PDF Downloads 82
484 Telomerase, a Biomarker in Oral Cancer Cell Proliferation and Tool for Its Prevention at Initial Stage

Authors: Shaista Suhail

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As cancer populations is increasing sharply, the incidence of oral squamous cell carcinoma (OSCC) has also been expected to increase. Oral carcinogenesis is a highly complex, multistep process which involves accumulation of genetic alterations that lead to the induction of proteins promoting cell growth (encoded by oncogenes), increased enzymatic (telomerase) activity promoting cancer cell proliferation. The global increase in frequency and mortality, as well as the poor prognosis of oral squamous cell carcinoma, has intensified current research efforts in the field of prevention and early detection of this disease. The advances in the understanding of the molecular basis of oral cancer should help in the identification of new markers. The study of the carcinogenic process of the oral cancer, including continued analysis of new genetic alterations, along with their temporal sequencing during initiation, promotion and progression, will allow us to identify new diagnostic and prognostic factors, which will provide a promising basis for the application of more rational and efficient treatments. Telomerase activity has been readily found in most cancer biopsies, in premalignant lesions or germ cells. Activity of telomerase is generally absent in normal tissues. It is known to be induced upon immortalization or malignant transformation of human cells such as in oral cancer cells. Maintenance of telomeres plays an essential role during transformation of precancer to malignant stage. Mammalian telomeres, a specialized nucleoprotein structures are composed of large conctamers of the guanine-rich sequence 5_-TTAGGG-3_. The roles of telomeres in regulating both stability of genome and replicative immortality seem to contribute in essential ways in cancer initiation and progression. It is concluded that activity of telomerase can be used as a biomarker for diagnosis of malignant oral cancer and a target for inactivation in chemotherapy or gene therapy. Its expression will also prove to be an important diagnostic tool as well as a novel target for cancer therapy. The activation of telomerase may be an important step in tumorgenesis which can be controlled by inactivating its activity during chemotherapy. The expression and activity of telomerase are indispensable for cancer development. There are no drugs which can effect extremely to treat oral cancers. There is a general call for new emerging drugs or methods that are highly effective towards cancer treatment, possess low toxicity, and have a minor environment impact. Some novel natural products also offer opportunities for innovation in drug discovery. Natural compounds isolated from medicinal plants, as rich sources of novel anticancer drugs, have been of increasing interest with some enzyme (telomerase) blockage property. The alarming reports of cancer cases increase the awareness amongst the clinicians and researchers pertaining to investigate newer drug with low toxicity.

Keywords: oral carcinoma, telomere, telomerase, blockage

Procedia PDF Downloads 175
483 The Impact of Regulation of Energy Prices on Public Trust in Europe during Energy Crisis: A Cross-Sectional Study in the Aftermath of the Russia-Ukraine Conflict

Authors: Sempiga Olivier, Dominika Latusek-Jurczak

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The conflict in Ukraine has had far-reaching economic consequences, not only for the countries directly involved in it but also for their trading partners and allies, and on the global economy in general. Different European Union (EU) countries, being some of Ukraine and Russia's major trading partners, have also felt the impact of the conflict on their economy. In a special way, the energy sector has suffered the most due to the fact that Russia is a huge exporter of gas and other energy sources on which rely European countries. Energy is a locomotive of the economy and once energy prices skyrocket there is a spill over effects in other areas causing different commodities’ prices to rise thereby affecting people’s social economic lifestyles. To minimise the impact energy crisis’ socio-political and economic consequences, the EU and countries have tightened their regulatory mechanisms to stop some energy firms exploit the crisis at the expense of the vulnerable mass. The key question is to what extent these regulatory instruments put in place during the energy crisis times have an affect on citizen trust in the governing institutions. The question is of paramount importance after years of declining trust in the EU and in most countries in Europe. Earlier research have analysed how wars or global political risks relate to citizen trust in government and organizations but very few empirical research have examined the relationship between regulatory instruments during the time of crisis on citizen trust in government and institutions. Using data from INSEE (the French National Institute of Statistics and Economic Studies) and European Social Survey (ESS), it carry out a multilinear regression analysis and investigate the impact of regulation both from the EU and different countries on energy prices on citizen trust. To understand the dynamics between regulatory actions during crises and citizen trust, this study draws on the theoretical framework of institutional trust and regulatory legitimacy. Institutional trust theory posits that citizens’ trust in government and institutions is influenced by perceptions of fairness, transparency, and efficacy in governance. Regulatory legitimacy, a related concept, suggests that regulatory measures, especially in response to crises, are more effective when perceived as just, necessary, and in the public interest. Results of this cross sectional study show that regulatory frameworks strongly affect the levels of trust, the association varying from strong to moderate depending on countries and period. This study contributes to the understanding of the vital relationship between regulatory measures implemented during crises and citizen trust in government institutions. By identifying the conditions under which trust is fostered or eroded, the findings provide policymakers with valuable insights into effective strategies for enhancing public confidence, ultimately guiding interventions that can mitigate the socio-political impacts of future energy crises.

Keywords: energy crisis, price, regulation, russia-Ukraine conflict, trust

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482 Test Rig Development for Up-to-Date Experimental Study of Multi-Stage Flash Distillation Process

Authors: Marek Vondra, Petr Bobák

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Vacuum evaporation is a reliable and well-proven technology with a wide application range which is frequently used in food, chemical or pharmaceutical industries. Recently, numerous remarkable studies have been carried out to investigate utilization of this technology in the area of wastewater treatment. One of the most successful applications of vacuum evaporation principal is connected with seawater desalination. Since 1950’s, multi-stage flash distillation (MSF) has been the leading technology in this field and it is still irreplaceable in many respects, despite a rapid increase in cheaper reverse-osmosis-based installations in recent decades. MSF plants are conveniently operated in countries with a fluctuating seawater quality and at locations where a sufficient amount of waste heat is available. Nowadays, most of the MSF research is connected with alternative heat sources utilization and with hybridization, i.e. merging of different types of desalination technologies. Some of the studies are concerned with basic principles of the static flash phenomenon, but only few scientists have lately focused on the fundamentals of continuous multi-stage evaporation. Limited measurement possibilities at operating plants and insufficiently equipped experimental facilities may be the reasons. The aim of the presented study was to design, construct and test an up-to-date test rig with an advanced measurement system which will provide real time monitoring options of all the important operational parameters under various conditions. The whole system consists of a conventionally designed MSF unit with 8 evaporation chambers, versatile heating circuit for different kinds of feed water (e.g. seawater, waste water), sophisticated system for acquisition and real-time visualization of all the related quantities (temperature, pressure, flow rate, weight, conductivity, pH, water level, power input), access to a wide spectrum of operational media (salt, fresh and softened water, steam, natural gas, compressed air, electrical energy) and integrated transparent features which enable a direct visual control of selected physical mechanisms (water evaporation in chambers, water level right before brine and distillate pumps). Thanks to the adjustable process parameters, it is possible to operate the test unit at desired operational conditions. This allows researchers to carry out statistical design and analysis of experiments. Valuable results obtained in this manner could be further employed in simulations and process modeling. First experimental tests confirm correctness of the presented approach and promise interesting outputs in the future. The presented experimental apparatus enables flexible and efficient research of the whole MSF process.

Keywords: design of experiment, multi-stage flash distillation, test rig, vacuum evaporation

Procedia PDF Downloads 387
481 Techno Economic Analysis of CAES Systems Integrated into Gas-Steam Combined Plants

Authors: Coriolano Salvini

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The increasing utilization of renewable energy sources for electric power production calls for the introduction of energy storage systems to match the electric demand along the time. Although many countries are pursuing as a final goal a “decarbonized” electrical system, in the next decades the traditional fossil fuel fed power plant still will play a relevant role in fulfilling the electric demand. Presently, such plants provide grid ancillary services (frequency control, grid balance, reserve, etc.) by adapting the output power to the grid requirements. An interesting option is represented by the possibility to use traditional plants to improve the grid storage capabilities. The present paper is addressed to small-medium size systems suited for distributed energy storage. The proposed Energy Storage System (ESS) is based on a Compressed Air Energy Storage (CAES) integrated into a Gas-Steam Combined Cycle (GSCC) or a Gas Turbine based CHP plants. The systems can be incorporated in an ex novo built plant or added to an already existing one. To avoid any geological restriction related to the availability of natural compressed air reservoirs, artificial storage is addressed. During the charging phase, electric power is absorbed from the grid by an electric driven intercooled/aftercooled compressor. In the course of the discharge phase, the compressed stored air is sent to a heat transfer device fed by hot gas taken upstream the Heat Recovery Steam Generator (HRSG) and subsequently expanded for power production. To maximize the output power, a staged reheated expansion process is adopted. The specific power production related to the kilogram per second of exhaust gas used to heat the stored air is two/three times larger than that achieved if the gas were used to produce steam in the HRSG. As a result, a relevant power augmentation is attained with respect to normal GSCC plant operations without additional use of fuel. Therefore, the excess of output power can be considered “fuel free” and the storage system can be compared to “pure” ESSs such as electrochemical, pumped hydro or adiabatic CAES. Representative cases featured by different power absorption, production capability, and storage capacity have been taken into consideration. For each case, a technical optimization aimed at maximizing the storage efficiency has been carried out. On the basis of the resulting storage pressure and volume, number of compression and expansion stages, air heater arrangement and process quantities found for each case, a cost estimation of the storage systems has been performed. Storage efficiencies from 0.6 to 0.7 have been assessed. Capital costs in the range of 400-800 €/kW and 500-1000 €/kWh have been estimated. Such figures are similar or lower to those featuring alternative storage technologies.

Keywords: artificial air storage reservoir, compressed air energy storage (CAES), gas steam combined cycle (GSCC), techno-economic analysis

Procedia PDF Downloads 214
480 Recognition of Sanitation as a Human Right: An Overview of Unresolutions and Reports That Recognizes the Human Right to Sanitation in South-Asian Countries

Authors: Anju Vaidya

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Sanitation is concerned with proper disposal of human excreta, waste water and promotion of hygiene. Lack of sanitation impacts our environment affecting our finance, schooling, health, and thus exacerbating poverty, discrimination and exclusion of the marginalized group. Sanitation can be a route and one of the most important factor to reach the goals of all Millennium Development goals. This study aims at exploring what are the rights to sanitation of the people, how it is enacted and what challenges are being faced while implementing the right to sanitation in South-Asian countries (India, Nepal, Pakistan, Bangladesh, Srilanka) at government, non-government and international level. This study also aims at finding how right sanitation is interlinked with children rights. The available reports submitted by government and civil society organizations working in South-Asian countries from the website of the Office of High Commissioner for Human Rights that were submitted under International covenant on economic, social and cultural rights and Convention on rights of the child have been selected and analyzed. The study uses Literature review to analyze these UN documents submitted from 2000 to 2015 in the context of South-Asian countries. Preliminary insight reveals that sanitation is recognized as one of the important factor to attain adequate standard of living. It has been found that inadequate sanitation has been a major factor that affects all aspects of life and one of its devastating impacts is increased child mortality. Many efforts have been made at national and international level in South-Asian countries to improve the state of sanitation and sanitation services. Various approaches such as Community led Total Sanitation, School led Total Sanitation, establishing Open Defecation free zone, water supply services and other sanitation and hygiene awareness programs are being launched. Despite different efforts and programs being implemented, sanitation and hygiene practices and behavior change remains to be a big challenge. Disparity in access and imbalance between urban and rural services and geographical regions, inadequate financing, clear policy framework and fragile functionality are some of the significant challenges faced while implementing these programs. Children are one of the most vulnerable group that are affected to a large extent. The study brings into light varied approaches that are being made and challenges that are being faced by government, non-government and civil society organizations while implementing the programs and strategies related to sanitation. It also highlights the relation of sanitation as a human right with child rights. This can help the stakeholders and policymakers better understand that improving sanitation situation is a process that requires learning, planning and behavior change and achieving sanitation coverage targets and motivating behavior change requires additional tools based on participation, non-discrimination and process approaches for planning and feedback.

Keywords: challenges, child rights, open defecation, sanitation as a human right

Procedia PDF Downloads 281
479 Influence of Urban Design on Pain and Disability in Women with Chronic Low Back Pain in Urban Cairo

Authors: Maha E. Ibrahim, Mona Abdel Aziz

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Background: Chronic low back pain (CLBP) in urban communities represents a challenge to healthcare systems worldwide. The traditional biomedical approach to back pain has been particularly inadequate. Failure of the biomedical model to explain the poor correlation between pain and disability on the one hand, and biological and physical factors that explain those symptoms on the other has led to the adoption of the biopsychosocial model, to recognize the reciprocal influence of physical, social and psychological factors implicated in CLBP, a condition that shows higher prevalence among women residing in urban areas. Urban design of the built community has been shown to exert a significant influence on physical and psychological health. However, little research has investigated the relationship between elements of the built environment, and the level of pain and disability of women with CLBP. As Egypt embarks on building a new capital city, and new settlements proliferate, better understanding of this relationship could greatly reduce the economic and human costs of this widespread medical problem for women. Methods: This study was designed as an exploratory mixed qualitative and quantitative study. Twenty-Six women with CLBP living in two neighborhoods in Cairo, different in their urban structure, but adjacent in their locations (Old Maadi and New Maadi) were interviewed using semi-structured interviews (8 from Old Maadi and 18 from New Maadi). Located in the South of Cairo, New Maadi is a neighborhood with the characteristic modern urban style (narrow streets and tall, adjacent buildings), while Old Maadi is known for being greener, quieter and more relaxed than the usual urban districts of Cairo. The interviews examined their perceptions of the built environment, including building shapes and colors and street light, as well as their sense of safety and comfort, and how it affects their physical and psychological health in general, and their back condition in particular. In addition, they were asked to rate their level of pain and to fill the Oswestry Disability Index (ODI), and the General Health Questionnaire (GHQ-12) to rate their level of disability and psychological status, respectively. Results: Women in both districts had moderate to severe pain and moderate disability with no significant differences between the two districts. However, those living in New Maadi had significantly worse scores on the GHQ-12 than those living in Old Maadi. Most women did not feel that specific elements of the built environment affected their back pain, however, they expressed distress of the elements that were ugly, distorted or damaged, especially where there were no ways of avoiding or fixing them. Furthermore, most women affirmed that the unsightly and uncomfortable elements of their neighborhoods affected their mood states and were a constant source of stress. Conclusion: This exploratory study concludes that elements of the urban built environment do not exert a direct effect on CLBP. However, the perception of women regarding these elements does affect their mood states, and their levels of stress, making them a possible indirect cause of increased suffering in these women.

Keywords: built environment, chronic back pain, disability, urban Cairo

Procedia PDF Downloads 146
478 Stakeholder-Driven Development of a One Health Platform to Prevent Non-Alimentary Zoonoses

Authors: A. F. G. Van Woezik, L. M. A. Braakman-Jansen, O. A. Kulyk, J. E. W. C. Van Gemert-Pijnen

Abstract:

Background: Zoonoses pose a serious threat to public health and economies worldwide, especially as antimicrobial resistance grows and newly emerging zoonoses can cause unpredictable outbreaks. In order to prevent and control emerging and re-emerging zoonoses, collaboration between veterinary, human health and public health domains is essential. In reality however, there is a lack of cooperation between these three disciplines and uncertainties exist about their tasks and responsibilities. The objective of this ongoing research project (ZonMw funded, 2014-2018) is to develop an online education and communication One Health platform, “eZoon”, for the general public and professionals working in veterinary, human health and public health domains to support the risk communication of non-alimentary zoonoses in the Netherlands. The main focus is on education and communication in times of outbreak as well as in daily non-outbreak situations. Methods: A participatory development approach was used in which stakeholders from veterinary, human health and public health domains participated. Key stakeholders were identified using business modeling techniques previously used for the design and implementation of antibiotic stewardship interventions and consisted of a literature scan, expert recommendations, and snowball sampling. We used a stakeholder salience approach to rank stakeholders according to their power, legitimacy, and urgency. Semi-structured interviews were conducted with stakeholders (N=20) from all three disciplines to identify current problems in risk communication and stakeholder values for the One Health platform. Interviews were transcribed verbatim and coded inductively by two researchers. Results: The following key values were identified (but were not limited to): (a) need for improved awareness of veterinary and human health of each other’s fields, (b) information exchange between veterinary and human health, in particularly at a regional level; (c) legal regulations need to match with daily practice; (d) professionals and general public need to be addressed separately using tailored language and information; (e) information needs to be of value to professionals (relevant, important, accurate, and have financial or other important consequences if ignored) in order to be picked up; and (f) need for accurate information from trustworthy, centrally organised sources to inform the general public. Conclusion: By applying a participatory development approach, we gained insights from multiple perspectives into the main problems of current risk communication strategies in the Netherlands and stakeholder values. Next, we will continue the iterative development of the One Health platform by presenting key values to stakeholders for validation and ranking, which will guide further development. We will develop a communication platform with a serious game in which professionals at the regional level will be trained in shared decision making in time-critical outbreak situations, a smart Question & Answer (Q&A) system for the general public tailored towards different user profiles, and social media to inform the general public adequately during outbreaks.

Keywords: ehealth, one health, risk communication, stakeholder, zoonosis

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477 Sustainability and Smart Cities Planning in Contrast with City Humanity. Human Scale and City Soul (Neighbourhood Scale)

Authors: Ghadir Hummeid

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Undoubtedly, our world is leading all the purposes and efforts to achieve sustainable development in life in all respects. Sustainability has been regarded as a solution to many challenges of our world today, materiality and immateriality. With the new consequences and challenges our world today, such as global climate change, the use of non-renewable resources, environmental pollution, the decreasing of urban health, the urban areas’ aging, the highly increasing migrations into urban areas linked to many consequences such as highly infrastructure density, social segregation. All of that required new forms of governance, new urban policies, and more efficient efforts and urban applications. Based on the fact that cities are the core of life and it is a fundamental life axis, their development can increase or decrease the life quality of their inhabitants. Architects and planners see themselves today in the need to create new approaches and new sustainable policies to develop urban areas to correspond with the physical and non-physical transformations that cities are nowadays experiencing. To enhance people's lives and provide for their needs in this present without compromising the needs and lives of future generations. The application of sustainability has become an inescapable part of the development and projections of cities' planning. Yet its definition has been indefinable due to the plurality and difference of its applications. As the conceptualizations of technology are arising and have dominated all life aspects today, from smart citizens and smart life rhythms to smart production and smart structures to smart frameworks, it has influenced the sustainability applications as well in the planning and urbanization of cities. The term "smart city" emerged from this influence as one of the possible key solutions to sustainability. The term “smart city” has various perspectives of applications and definitions in the literature and in urban applications. However, after the observation of smart city applications in current cities, this paper defined the smart city as an urban environment that is controlled by technologies yet lacks the physical architectural representation of this smartness as the current smart applications are mostly obscured from the public as they are applied now on a diminutive scale and highly integrated into the built environment. Regardless of the importance of these technologies in improving the quality of people's lives and in facing cities' challenges, it is important not to neglect their architectural and urban presentations will affect the shaping and development of city neighborhoods. By investigating the concept of smart cities and exploring its potential applications on a neighbourhood scale, this paper aims to shed light on understanding the challenges faced by cities and exploring innovative solutions such as smart city applications in urban mobility and how they affect the different aspects of communities. The paper aims to shape better articulations of smart neighborhoods’ morphologies on the social, architectural, functional, and material levels. To understand how to create more sustainable and liveable future approaches to developing urban environments inside cities. The findings of this paper will contribute to ongoing discussions and efforts in achieving sustainable urban development.

Keywords: sustainability, urban development, smart city, resilience, sense of belonging

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476 The Effect of Artificial Intelligence on Mobile Phones and Communication Systems

Authors: Ibram Khalafalla Roshdy Shokry

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This paper gives service feel multiple get entry to (CSMA) verbal exchange model based totally totally on SoC format method. Such model can be used to guide the modelling of the complex c084d04ddacadd4b971ae3d98fecfb2a communique systems, consequently use of such communication version is an crucial method in the creation of excessive general overall performance conversation. SystemC has been selected as it gives a homogeneous format drift for complicated designs (i.e. SoC and IP based format). We use a swarm device to validate CSMA designed version and to expose how advantages of incorporating communication early within the layout process. The wireless conversation created via the modeling of CSMA protocol that may be used to attain conversation among all of the retailers and to coordinate get proper of entry to to the shared medium (channel).The device of automobiles with wi-fiwireless communique abilities is expected to be the important thing to the evolution to next era intelligent transportation systems (ITS). The IEEE network has been continuously operating at the development of an wireless vehicular communication protocol for the enhancement of wi-fi get admission to in Vehicular surroundings (WAVE). Vehicular verbal exchange systems, known as V2X, help car to car (V2V) and automobile to infrastructure (V2I) communications. The wi-ficiencywireless of such communication systems relies upon on several elements, amongst which the encircling surroundings and mobility are prominent. as a result, this observe makes a speciality of the evaluation of the actual performance of vehicular verbal exchange with unique cognizance on the effects of the actual surroundings and mobility on V2X verbal exchange. It begins by wi-fi the actual most range that such conversation can guide and then evaluates V2I and V2V performances. The Arada LocoMate OBU transmission device changed into used to check and evaluate the effect of the transmission range in V2X verbal exchange. The evaluation of V2I and V2V communique takes the real effects of low and excessive mobility on transmission under consideration.Multiagent systems have received sizeable attention in numerous wi-fields, which include robotics, independent automobiles, and allotted computing, where a couple of retailers cooperate and speak to reap complicated duties. wi-figreen communication among retailers is a critical thing of these systems, because it directly influences their usual performance and scalability. This scholarly work gives an exploration of essential communication factors and conducts a comparative assessment of diverse protocols utilized in multiagent systems. The emphasis lies in scrutinizing the strengths, weaknesses, and applicability of those protocols across diverse situations. The studies additionally sheds light on rising tendencies within verbal exchange protocols for multiagent systems, together with the incorporation of device mastering strategies and the adoption of blockchain-based totally solutions to make sure comfy communique. those developments offer valuable insights into the evolving landscape of multiagent structures and their verbal exchange protocols.

Keywords: communication, multi-agent systems, protocols, consensussystemC, modelling, simulation, CSMA

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475 Hydrogen Production from Auto-Thermal Reforming of Ethanol Catalyzed by Tri-Metallic Catalyst

Authors: Patrizia Frontera, Anastasia Macario, Sebastiano Candamano, Fortunato Crea, Pierluigi Antonucci

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The increasing of the world energy demand makes today biomass an attractive energy source, based on the minimizing of CO2 emission and on the global warming reduction purposes. Recently, COP-21, the international meeting on global climate change, defined the roadmap for sustainable worldwide development, based on low-carbon containing fuel. Hydrogen is an energy vector able to substitute the conventional fuels from petroleum. Ethanol for hydrogen production represents a valid alternative to the fossil sources due to its low toxicity, low production costs, high biodegradability, high H2 content and renewability. Ethanol conversion to generate hydrogen by a combination of partial oxidation and steam reforming reactions is generally called auto-thermal reforming (ATR). The ATR process is advantageous due to the low energy requirements and to the reduced carbonaceous deposits formation. Catalyst plays a pivotal role in the ATR process, especially towards the process selectivity and the carbonaceous deposits formation. Bimetallic or trimetallic catalysts, as well as catalysts with doped-promoters supports, may exhibit high activity, selectivity and deactivation resistance with respect to the corresponding monometallic ones. In this work, NiMoCo/GDC, NiMoCu/GDC and NiMoRe/GDC (where GDC is Gadolinia Doped Ceria support and the metal composition is 60:30:10 for all catalyst) have been prepared by impregnation method. The support, Gadolinia 0.2 Doped Ceria 0.8, was impregnated by metal precursors solubilized in aqueous ethanol solution (50%) at room temperature for 6 hours. After this, the catalysts were dried at 100°C for 8 hours and, subsequently, calcined at 600°C in order to have the metal oxides. Finally, active catalysts were obtained by reduction procedure (H2 atmosphere at 500°C for 6 hours). All sample were characterized by different analytical techniques (XRD, SEM-EDX, XPS, CHNS, H2-TPR and Raman Spectorscopy). Catalytic experiments (auto-thermal reforming of ethanol) were carried out in the temperature range 500-800°C under atmospheric pressure, using a continuous fixed-bed microreactor. Effluent gases from the reactor were analyzed by two Varian CP4900 chromarographs with a TCD detector. The analytical investigation focused on the preventing of the coke deposition, the metals sintering effect and the sulfur poisoning. Hydrogen productivity, ethanol conversion and products distribution were measured and analyzed. At 600°C, all tri-metallic catalysts show the best performance: H2 + CO reaching almost the 77 vol.% in the final gases. While NiMoCo/GDC catalyst shows the best selectivity to hydrogen whit respect to the other tri-metallic catalysts (41 vol.% at 600°C). On the other hand, NiMoCu/GDC and NiMoRe/GDC demonstrated high sulfur poisoning resistance (up to 200 cc/min) with respect to the NiMoCo/GDC catalyst. The correlation among catalytic results and surface properties of the catalysts will be discussed.

Keywords: catalysts, ceria, ethanol, gadolinia, hydrogen, Nickel

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474 Predictors, Barriers, and Facilitators to Refugee Women’s Employment and Economic Inclusion: A Mixed Methods Systematic Review

Authors: Areej Al-Hamad, Yasin Yasin, Kateryna Metersky

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This mixed-method systematic review and meta-analysis provide an encompassing understanding of the barriers, facilitators, and predictors of refugee women's employment and economic inclusion. The study sheds light on the complex interplay of sociocultural, personal, political, and environmental factors influencing these outcomes, underlining the urgent need for a multifaceted, tailored approach to devising strategies, policies, and interventions aimed at boosting refugee women's economic empowerment. Our findings suggest that sociocultural factors, including gender norms, societal attitudes, language proficiency, and social networks, profoundly shape refugee women's access to and participation in the labor market. Personal factors such as age, educational attainment, health status, skills, and previous work experience also play significant roles. Political factors like immigration policies, regulations, and rights to work, alongside environmental factors like labor market conditions, availability of employment opportunities, and access to resources and support services, further contribute to the complex dynamics influencing refugee women's economic inclusion. The significant variability observed in the impacts of these factors across different contexts underscores the necessity of adopting population and region-specific strategies. A one-size-fits-all approach may prove to be ineffective due to the diversity and unique circumstances of refugee women across different geographical, cultural, and political contexts. The study's findings have profound implications for policy-making, practice, education, and research. The insights garnered a call for coordinated efforts across these domains to bolster refugee women's economic participation. In policy-making, the findings necessitate a reassessment of current immigration and labor market policies to ensure they adequately support refugee women's employment and economic integration. In practice, they highlight the need for comprehensive, tailored employment services and interventions that address the specific barriers and leverage the facilitators identified. In education, they underline the importance of language and skills training programs that cater to the unique needs and circumstances of refugee women. Lastly, in research, they emphasize the need for ongoing investigations into the multifaceted factors influencing refugee women's employment experiences, allowing for continuous refinement of our understanding and interventions. Through this comprehensive exploration, the study contributes to ongoing efforts aimed at creating more inclusive, equitable societies. By continually refining our understanding of the complex factors influencing refugee women's employment experiences, we can pave the way toward enhanced economic empowerment for this vulnerable population.

Keywords: refugee women, employment barriers, systematic review, employment facilitators

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473 Thermoluminescence Investigations of Tl2Ga2Se3S Layered Single Crystals

Authors: Serdar Delice, Mehmet Isik, Nizami Hasanli, Kadir Goksen

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Researchers have donated great interest to ternary and quaternary semiconductor compounds especially with the improvement of the optoelectronic technology. The quaternary compound Tl2Ga2Se3S which was grown by Bridgman method carries the properties of ternary thallium chalcogenides group of semiconductors with layered structure. This compound can be formed from TlGaSe2 crystals replacing the one quarter of selenium atom by sulfur atom. Although Tl2Ga2Se3S crystals are not intentionally doped, some unintended defect types such as point defects, dislocations and stacking faults can occur during growth processes of crystals. These defects can cause undesirable problems in semiconductor materials especially produced for optoelectronic technology. Defects of various types in the semiconductor devices like LEDs and field effect transistor may act as a non-radiative or scattering center in electron transport. Also, quick recombination of holes with electrons without any energy transfer between charge carriers can occur due to the existence of defects. Therefore, the characterization of defects may help the researchers working in this field to produce high quality devices. Thermoluminescence (TL) is an effective experimental method to determine the kinetic parameters of trap centers due to defects in crystals. In this method, the sample is illuminated at low temperature by a light whose energy is bigger than the band gap of studied sample. Thus, charge carriers in the valence band are excited to delocalized band. Then, the charge carriers excited into conduction band are trapped. The trapped charge carriers are released by heating the sample gradually and these carriers then recombine with the opposite carriers at the recombination center. By this way, some luminescence is emitted from the samples. The emitted luminescence is converted to pulses by using an experimental setup controlled by computer program and TL spectrum is obtained. Defect characterization of Tl2Ga2Se3S single crystals has been performed by TL measurements at low temperatures between 10 and 300 K with various heating rate ranging from 0.6 to 1.0 K/s. The TL signal due to the luminescence from trap centers revealed one glow peak having maximum temperature of 36 K. Curve fitting and various heating rate methods were used for the analysis of the glow curve. The activation energy of 13 meV was found by the application of curve fitting method. This practical method established also that the trap center exhibits the characteristics of mixed (general) kinetic order. In addition, various heating rate analysis gave a compatible result (13 meV) with curve fitting as the temperature lag effect was taken into consideration. Since the studied crystals were not intentionally doped, these centers are thought to originate from stacking faults, which are quite possible in Tl2Ga2Se3S due to the weakness of the van der Waals forces between the layers. Distribution of traps was also investigated using an experimental method. A quasi-continuous distribution was attributed to the determined trap centers.

Keywords: chalcogenides, defects, thermoluminescence, trap centers

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