Search results for: interest flooding attack

Authors: Mohammad A. Bani-Khaled

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In this work we use the Discrete Proper Orthogonal Decomposition transform to characterize the properties of coupled dynamics in thin-walled beams by exploiting numerical simulations obtained from finite element simulations. The outcomes of the will improve our understanding of the linear and nonlinear coupled behavior of thin-walled beams structures. Thin-walled beams have widespread usage in modern engineering application in both large scale structures (aeronautical structures), as well as in nano-structures (nano-tubes). Therefore, detailed knowledge in regard to the properties of coupled vibrations and buckling in these structures are of great interest in the research community. Due to the geometric complexity in the overall structure and in particular in the cross-sections it is necessary to involve computational mechanics to numerically simulate the dynamics. In using numerical computational techniques, it is not necessary to over simplify a model in order to solve the equations of motions. Computational dynamics methods produce databases of controlled resolution in time and space. These numerical databases contain information on the properties of the coupled dynamics. In order to extract the system dynamic properties and strength of coupling among the various fields of the motion, processing techniques are required. Time- Proper Orthogonal Decomposition transform is a powerful tool for processing databases for the dynamics. It will be used to study the coupled dynamics of thin-walled basic structures. These structures are ideal to form a basis for a systematic study of coupled dynamics in structures of complex geometry.

Keywords: coupled dynamics, geometric complexity, proper orthogonal decomposition (POD), thin walled beams

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Authors: Emmanuel Dangana Monday

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Africa as a continent has been ravaged and bedeviled by series of political conflicts associated with politics and power-sharing maneuvering. As a result it has become the most unstable continent in the world in terms of power distribution and stable political culture. This paper examines the efficacy of conscious and deliberate power-sharing strategies to settle or resolve political conflicts in Africa in the arrangements of creation of states, revenue and resources allocation, and office distribution systems. The study is concerned with the spatial impact of conflicts generated in some renowned African countries in which power-sharing would have been a solution. Ethno-regional elite groups are identified as the major actors in the struggles for the distribution of territorial, economic and political powers in Africa. The struggle for power has become so intense that it has degenerated to conflicts and wars of inter and intra-political classes and parties respectively. Secondary data and deductive techniques were used in data collection and analysis. It is discovered that power-sharing has become an indispensable tool to curb the incessant political and power crisis in Africa. It is one of the finest tolerable modality of mediating elite’ competition, since it reflects the interests of both the dominant and the perceived marginalized groups. The study recommends that countries and regions of political, ethnic and religious differences in Africa should employed power-sharing strategy in order to avoid unnecessary political tension and resultant crisis. Interest groups should always come to the negotiation table to reach a realistic, durable and expected compromise to secure a peacefully resolute Africa.

Keywords: Africa, power-sharing, conflicts, politics and political stability

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Authors: Zhifei Hu, Feng Xia

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In recent years, Graph neural network has been widely used in knowledge graph recommendation. The existing recommendation methods based on graph neural network extract information from knowledge graph through entity and relation, which may not be efficient in the way of information extraction. In order to better propose useful entity information for the current recommendation task in the knowledge graph, we propose an end-to-end Neural network Model based on multi-stream graph attentional Mechanism (MSGAT), which can effectively integrate the knowledge graph into the recommendation system by evaluating the importance of entities from both users and items. Specifically, we use the attention mechanism from the user's perspective to distil the domain nodes information of the predicted item in the knowledge graph, to enhance the user's information on items, and generate the feature representation of the predicted item. Due to user history, click items can reflect the user's interest distribution, we propose a multi-stream attention mechanism, based on the user's preference for entities and relationships, and the similarity between items to be predicted and entities, aggregate user history click item's neighborhood entity information in the knowledge graph and generate the user's feature representation. We evaluate our model on three real recommendation datasets: Movielens-1M (ML-1M), LFM-1B 2015 (LFM-1B), and Amazon-Book (AZ-book). Experimental results show that compared with the most advanced models, our proposed model can better capture the entity information in the knowledge graph, which proves the validity and accuracy of the model.

Keywords: graph attention network, knowledge graph, recommendation, information propagation

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Authors: Sadaf Karkoodi, Hassan Karampour

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There is a growing interest in the construction industry towards hybrid systems. The hybrid systems use construction materials such as timber, steel, and concrete smartly, can be prefabricated, and are cost-effective and sustainable solutions to an industry targeting reduced carbon footprint. Moreover, in case of periodical shortage in timber resources, reusable and waste wood such as fibres can be used in the hybrid modules, which facilitates the circular economy. In this research, a hybrid frame is proposed and experimentally validated by introducing dried wood fibre products inside cold-formed steel square hollow sections without using any adhesives. As such, fibre-filled steel tubular (FFST) columns, beams, and 2D frames are manufactured and tested. The results show that the FFST columns have stiffness and strength 44% and 55% higher than cold-formed steel columns, respectively. The bearing strength of the FFST beams shows an increase of 39.5% compared to steel only. The flexural stiffness and strength of the FFST beams are 8.5% and 28% higher than the bare steel beams, respectively. The FFST frame depicted an 18.4% higher ultimate load capacity than the steel-only frame under a mid-point concentrated load. Moreover, the FFST beam-to-column bolted connection showed high ductile performance. The initial results and the proposed simple manufacturing process suggest that the proposed FFST concept can be upscaled and used in real structures.

Keywords: wood fibre, reusing wood, fibre-filled steel, hybrid construction

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Authors: Mick Jackowski

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In terms of popularity in the United States, horse racing has been in a steady state of decline since the 1970s. This trend can be attributed to deterioration in the prestige of the sport, due to a shift in cultural values around the treatment of horses, as well as the growing interest of other sports and gambling options. Despite this drift, horse racing still commands a significant piece of the sport landscape through specific events like the Triple Crown and the Breeders Cup. The 2024 Kentucky Derby enjoyed it largest peak television audience (20.1 million) ever. It is because of this still significant attraction to thoroughbred racing that hope exists, not only for the survivability of one of the oldest organized sports in North America, but also for its future growth. But the spectacle that makes select races very popular must be expanded to tracks around the country on a regular basis. The first step is to create a centralized governing body that regulates operation of all races at all tracks in the country, instead of the state-by-state government fiefdoms that currently oversee operations in each jurisdiction. One league office, if you will, can also better coordinate marketing efforts to promote races. These promotions, though, must be targeted to specific audiences, focusing on the strengths that horse racing has in relation to other recreational activities. The industry should utilize a multi-segment strategy that targets the following four groups: Families, Young Adults, Fashion-Conscious, and Sports Bettors. Beyond the traditional marketing mix, the most vital means of establishing and maintaining relationships with each of these consumer segments is through community building.

Keywords: community building, horse racing, sport marketing, thoroughbreds

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Authors: Inalegwu Stephany Akipu

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A cultural festival is characterized by feasting and celebration, with a day or period that has been set aside solely for this reason. Often expressed by an organized series of acts and performances, it forms a very important part of man’s cultural heritage. Nigeria is a country with many ethnic groups and diverse languages. Each of these ethnic groups has a plethora of festivals that depict their culture which is exhibited in many forms ranging from dancing to feasting and celebration. Being a very important aspect of man’s life, it is pertinent to document and optimally harness it. However, there is a significant decline of these practices in some areas in Nigeria while some areas have registered a total loss of same. It is the aim of this paper therefore, to appraise the factors responsible for this and also, to project ways of resuscitating these festivals which by the way are viable tools for revenue generation through tourism. Not only do festivals serve as a source of revenue, they also aid in national integration which in turn further enhances sustainable development. The interest of this paper will focus on the Kuteb people of Taraba State and the Idoma people of Benue State. The methodologies applied include primary (oral interviews) and secondary (consultation of written records on the subject matter) sources of data. It finally concludes by comparing the approaches that are in use by the ethnic groups in Nigeria who have successfully preserved this aspect their culture and suggestions are made as to how to apply same approaches to these two communities that form the subject of this paper.

Keywords: festival, cultural heritage, Nigeria, national integration, sustainable development

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Authors: Mohd Afif Md Nasir, Faizal Amin Nur Yunus, Jamaluddin Hashim, Abd Samad Hassan Basari, A. Halim Sahelan

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The aim of this study is to identify the suitability of Virtual Learning Environment (VLE) in welding simulator application towards Computer-Based Training (CBT) in developing skills upon new students at the Advanced Technology Training Center (ADTEC), Batu Pahat, Johor, Malaysia and GIATMARA, Batu Pahat, Johor, Malaysia. The purpose of the study is to create a computer-based skills development approach in welding technology among new students in ADTEC and GIATMARA, as well as cultivating the elements of general skills among them. This study is also important in elevating the number of individual knowledge workers (K-workers) working in manufacturing industry in order to achieve a national vision which is to be an industrial nation in the year of 2020. The design of the study is a survey type of research which uses questionnaires as the instruments and 136 students from ADTEC and GIATMARA were interviewed. Descriptive analysis is used to identify the frequency and mean values. The findings of the study shows that the welding technology skills have developed in the students as a result of the application of VLE simulator at a high level and the respondents agreed that the skills could be embedded through the application of the VLE simulator. In summary, the VLE simulator is suitable in welding skills development training in terms of exposing new students with the relevant characteristics of welding skills and at the same time spurring the students’ interest towards learning more about the skills.

Keywords: computer-based training (CBT), knowledge workers (K-workers), virtual learning environment, welding simulator, welding technology

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Authors: Tien S. H. Pham, Peter J. Mahon, Aimin Yu

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The detection of drug molecules by voltammetry has attracted great interest over the past years. However, many drug molecules exhibit poor electrochemical signals at common electrodes which result in low sensitivity in detection. An efficient way to overcome this problem is to modify electrodes with functional materials. Since discovered in 2004, graphene (or reduced graphene oxide) has emerged as one of the most studied two-dimensional carbon materials in condensed matter physics, electrochemistry, and so on due to its exceptional physicochemical properties. Additionally, the continuous development of technology has opened the new window for the successful fabrications of many novel graphene-based nanomaterials to serve in electrochemical analysis. This research aims to synthesize and characterize gold nanoparticle coated beta-cyclodextrin functionalized reduced graphene oxide (Au NP–β-CD–RGO) nanocomposites with highly conductive and strongly electro-catalytic properties as well as excellent supramolecular recognition abilities for the modification of electrodes. The electrochemical responses of ciprofloxacin at the as-prepared nanocomposite modified electrode was effectively amplified was much higher in comparison with that at the bare electrode. The linear concentration range was from 0.01 to 120 µM, with a detection limit of 2.7 nM using differential pulse voltammetry. Thus, Au NP–β-CD–RGO nanocomposite has great potential as an ideal material to construct sensitive sensors for the electrochemical determination of ciprofloxacin or similar antibacterial drugs in the future based on its excellent stability, selectivity, and reproducibility.

Keywords: Au nanoparticles, β-CD, ciprofloxacin, electrochemical determination, graphene based nanomaterials

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Authors: Fajana Sola Isaac

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In the last two decades, we have witnessed an increased interest in exchange rate pass-through (ERPT) in developing economies and emerging markets. This is perhaps due to the acknowledged significance of the pattern of exchange rate pass-through as a key instrument in monetary policy design, principally in retort to a shock in exchange rate in literature. This paper analyzed Exchange Rate Pass-Through by A Model of Oil Prices and Asymmetric Exchange Rate Fluctuations in Selected African Countries. The study adopted A Non-Linear Autoregressive Distributed Lag approach using yearly data on Algeria, Burundi, Nigeria and South Africa from 1986 to 2022. The paper found asymmetry in exchange rate pass-through in net oil-importing and net oil-exporting countries in the short run during the period under review. An ERPT exhibited a complete pass-through in the short run in the case of net oil-importing countries but an incomplete pass-through in the case of the net oil-exporting countries that were examined. An extended result revealed a significant impact of oil price shock on exchange rate pass-through to domestic price in the long run only for net oil importing countries. The Wald restriction test also confirms the evidence of asymmetric with the role of oil price acting as an accelerator to exchange rate pass-through to domestic price in the countries examined. The study found the outcome to be very useful for gaining expansive knowledge on the external shock impact on ERPT and could be of critical value for national monetary policy decisions on inflation targeting, especially for countries examined and other developing net oil importers and exporters.

Keywords: pass through, exchange rate, ARDL, monetary policy

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Authors: A. Bendarma, T. Jankowiak, A. Rusinek, T. Lodygowski, M. Klósak, S. Bouslikhane

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The analysis of the mechanical characteristics and dynamic behavior of aluminum alloy sheet due to perforation tests based on the experimental tests coupled with the numerical simulation is presented. The impact problems (penetration and perforation) of the metallic plates have been of interest for a long time. Experimental, analytical as well as numerical studies have been carried out to analyze in details the perforation process. Based on these approaches, the ballistic properties of the material have been studied. The initial and residual velocities laser sensor is used during experiments to obtain the ballistic curve and the ballistic limit. The energy balance is also reported together with the energy absorbed by the aluminum including the ballistic curve and ballistic limit. The high speed camera helps to estimate the failure time and to calculate the impact force. A wide range of initial impact velocities from 40 up to 180 m/s has been covered during the tests. The mass of the conical nose shaped projectile is 28 g, its diameter is 12 mm, and the thickness of the aluminum sheet is equal to 1.0 mm. The ABAQUS/Explicit finite element code has been used to simulate the perforation processes. The comparison of the ballistic curve was obtained numerically and was verified experimentally, and the failure patterns are presented using the optimal mesh densities which provide the stability of the results. A good agreement of the numerical and experimental results is observed.

Keywords: aluminum alloy, ballistic behavior, failure criterion, numerical simulation

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Authors: AlHanoof A. Alharbi, Fatima M. Alamoudi, Razan A. Albrahim, Sarah F. Alharbi, Abdullah M Almuhaideb, Norah A. Almubairik, Abdulrahman Alharby, Naya M. Nagy

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Recently, drones received a rapid interest in different industries worldwide due to its powerful impact. However, limitations still exist in this emerging technology, especially privacy violation. These aircrafts consistently threaten the security of entities by entering restricted areas accidentally or deliberately. Therefore, this research project aims to develop drone detection and prevention mechanism to protect the restricted area. Until now, none of the solutions have met the optimal requirements of detection which are cost-effectiveness, high accuracy, long range, convenience, unaffected by noise and generalization. In terms of prevention, the existing methods are focusing on impractical solutions such as catching a drone by a larger drone, training an eagle or a gun. In addition, the practical solutions have limitations, such as the No-Fly Zone and PITBULL jammers. According to our study and analysis of previous related works, none of the solutions includes detection and prevention at the same time. The proposed solution is a combination of detection and prevention methods. To implement the detection system, a passive radar will be used to properly identify the drone against any possible flying objects. As for the prevention, jamming signals and forceful safe landing of the drone integrated together to stop the drone’s operation. We believe that applying this mechanism will limit the drone’s invasion of privacy incidents against highly restricted properties. Consequently, it effectively accelerates drones‘ usages at personal and governmental levels.

Keywords: detection, drone, jamming, prevention, privacy, RF, radar, UAV

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Authors: Gabriel S. De Oliveira, Patricia P. Adriani, Christophe Moriseau, Bruce D. Hammock, Felipe S. Chambergo

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Epoxide hydrolases (EHs) are enzymes that are present in all living organisms and catalyze the hydrolysis of epoxides to the corresponding vicinal diols. EHs have high biotechnological interest for the drug design and chemistry transformation for industries. In this study, we describe the identification of substrates and inhibitors of epoxide hydrolase enzyme from the filamentous fungus Trichoderma reesei (TrEH), and these inhibitors showed the fungal growth inhibitory activity. We have used the cloned enzyme and expressed in E. coli to develop the screening in the library of fluorescent substrates with the objective of finding the best substrate to be used in the identification of good inhibitors for the enzyme TrEH. The substrate (3-phenyloxiranyl)-acetic acid cyano-(6-methoxy-naphthalen-2-yl)-methyl ester showed the highest specific activity and was chosen for the next steps of the study. The inhibitors screening was performed in the library with more than three thousand molecules and we could identify the 6 best inhibitors. The IC50 of these molecules were determined in nM and all the best inhibitors have urea or amide in their structure, because It has been recognized that these groups fit well in the hydrolase catalytic pocket of the epoxide hydrolases. Then the growth of T. reesei in PDA medium containing these TrEH inhibitors was tested, and fungal growth inhibition activity was demonstrated with more than 60% of inhibition of fungus growth in the assay with the TrEH inhibitor with the lowest IC50. Understanding how this EH enzyme from T. reesei responds to inhibitors may contribute for the study of fungal metabolism and drug design against pathogenic fungi.

Keywords: epoxide hydrolases, fungal growth inhibition, inhibitor, Trichoderma reesei

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Authors: Dainius Genys, Vylius Leonavicius, Ricardas Krikstolaitis

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Energy security problems in Lithuania are analyzed on a regular basis; however, there is no comprehensive research on the very issue of the concept of public energy security. There is a lack of attention not only to social determinants of perception of energy security, but also a lack of a deeper analysis of the public opinion. This article aims to research the Lithuanian public perception of energy security. Complex tasks were set during the sociological study. Survey questionnaire consisted of different sets of questions: view of energy security (risk perception, political orientation, and energy security; comprehensiveness and energy security); view of energy risks and threats (perception of energy safety factors; individual dependence and burden; disobedience and risk); view of the activity of responsible institutions (energy policy assessment; confidence in institutions and energy security), demographic issues. In this article, we will focus on two aspects: a) We will analyze public opinion on the most important aspects of energy security and social factors influencing them; The hypothesis is made that public perception of energy security is related to value orientations: b) We will analyze how public opinion on energy policy executed by the government and confidence in the government are intertwined with the concept of energy security. Data of the survey, conducted on May 10-19 and June 7-17, 2013, when Seimas and the government consisted of the coalition dominated by Social Democrats with Labor, Order and Justice Parties and the Electoral Action of Poles, were used in this article. It is important to note that the survey was conducted prior to Russia’s occupation of the Crimea.

Keywords: energy security, public opinion, risk, energy threat, energy security policy

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Authors: Seyyed Kavous Abbasi

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Technical and professional branch is a subcategory of high school educational system. It deals with the programs which have been designed for the promotion of applied science and necessary skill and growth of potential talents in students. The purpose of performance of this branch is preparing of preponderance of in police in different section of industries and service. The aim of this research is the survey of group relation family, economic, educational and individual factors and the student's tendency toward technical professional courses. The method of the study is descriptive survey. 195 subjects were chosen randomly from all the male and female students of technical and professional school in Izeh. Instrument for this research was research-made questionnaire consisting of 22 questions on the base of likers spectrum. The reliability of this questionnaire has been estimated 0.8. Analyses of research data has been performed in two levels of descriptive and inferential statistics. Analyses of data has shown that the family factors with average of 3.12, individual factors 3.95, economic factors 3.92 and educational factors 3.57 more than middle level have more effects , in comparison with the factor of group relation with average of 2.79 less than average level in tendency the technical and professional course . Comparison of effective factors in tendency to technical and professional course has shown that individual factors had the most effects and the group relation factors had the least effects. Comparison between male and female subject's ideas showed that there is a different between their ideas about economics and family factors.

Keywords: high school, relation family, individual factors, analysis interest

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Authors: Neha Parekh, Divya Ladha, Poonam Wadhwani, Nisha Shah

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Nano scaled materials have attracted tremendous interest as corrosion inhibitor due to their high surface area on the metal surfaces. It is well known that the zinc oxide nanoparticles have higher reactivity towards aqueous acidic solution. This work presents a new method to incorporate zinc oxide nanoparticles with white sesame seeds extract (nano-green inhibitor) for corrosion protection of zinc in acidic medium. The morphology of the zinc oxide nanoparticles was investigated by TEM and DLS. The corrosion inhibition efficiency of the green inhibitor and nano-green inhibitor was determined by Gravimetric and electrochemical impedance spectroscopy (EIS) methods. Gravimetric measurements suggested that nano-green inhibitor is more effective than green inhibitor. Furthermore, with the increasing temperature, inhibition efficiency increases for both the inhibitors. In addition, it was established the Temkin adsorption isotherm fits well with the experimental data for both the inhibitors. The effect of temperature and Temkin adsorption isotherm revealed Chemisorption mechanism occurring in the system. The activation energy (Ea) and other thermodynamic parameters for inhibition process were calculated. The data of EIS showed that the charge transfer controls the corrosion process. The surface morphology of zinc metal (specimen) in absence and presence of green inhibitor and nano-green inhibitor were performed using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) techniques. The outcomes indicated a formation of a protective layer over zinc metal (specimen).

Keywords: corrosion, green inhibitor, nanoparticles, zinc

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Authors: Anna Perrone, Federico Martinelli

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Olive fruit is well-known for the high content in secondary metabolites with high interest at nutritional, nutraceutical, antioxidant, and healthy levels. The content of secondary metabolites in olive at harvest may be affected by different water regimes, with significant effects on olive oil composition and quality and, consequently, on its healthy and nutritional features. In this work, a summary of several research studies dealing with the biosynthesis of healthy and nutraceutical metabolites of the secondary metabolism in olive fruit will be reported. The phytochemical findings have been correlated with the expression of key genes involved in polyphenol, terpenoid, and carotenoid biosynthesis and metabolism in response to different development stages and water regimes. Flavonoids were highest in immature fruits, while anthocyanins increased at ripening. In epicarp tissue, this was clearly associated with an up-regulation of the UFGT gene. Olive fruits cultivated under different water regimes were analyzed by metabolomics. This method identified several hundred metabolites in the ripe mesocarp. Among them, 46 were differentially accumulated in the comparison between rain-fed and irrigated conditions. Well-known healthy metabolites were more abundant at a higher level of water regimes. Increased content of polyphenols was observed in the rain-fed fruit; particularly, anthocyanin concentration was higher at ripening. Several secondary metabolites were differentially accumulated between different irrigation conditions. These results showed that these metabolic approaches could be efficiently used to determine the effects of agronomic treatments on olive fruit physiology and, consequently, on nutritional and healthy properties of the obtained extra-virgin olive oil.

Keywords: olea europea, anthocyanins, polyphenols, water regimes

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Authors: Abdullah Alshakhi

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This study aims to explore the assessment practices of transnational western teachers in Saudi EFL writing classrooms. The study adopts a critical ethnographic approach to understand the views and the experiences of four transnational TESOL professionals about how they navigate and negotiate their writing assessment practices in the Saudi EFL context. The qualitative data were collected through classroom observations and video recordings of the classroom teaching, which were followed by semi-structured interviews with the four TESOL teachers from Australia, England, USA, and Ireland. The data were analyzed from three perspectives of these transnational TESOL teachers in the Saudi EFL context: as a transnational teacher in monolingual context, as a transitional teacher abides by the prescribed curriculum and assessment instructions, and as a transnational teacher’s vision for monolingual students. The results of the study revealed that owing to the transnational teachers’ lack of understanding of the Saudi monolingual culture, bureaucratic structures, and top-down assessment policies in the institute where they work, their teaching and assessment of writing and other language skills are negatively affected and consequently had to be modified. Also, the Saudi learners’ lack of interest and their lower level of English proficiency pose serious challenges to those transnational teachers’ writing assessment practices. More often, the teachers find the prescribed writing curriculum and assessment tools ineffective in the Saudi EFL context. Because of these experiences, the transnational teachers in this study have exhibited their awareness of their monolingual/monoculture background, Saudi’s cultural and religious values, and institutional structures, which have helped them customize or supplement the writing assessment practices accordingly.

Keywords: critical ethnography, Saudi EFL context, TESOL professionals, transnationalism, writing assessment

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Authors: Ali Kassem, Yaser Kamal, Mohamed Abdel Wahab, Mohamed Hussen

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Introduction: Atherosclerosis is one of the leading causes of death all over the world. Recently, there is an increasing interest in Carotid Intima-Medial Thickness (CIMT) and Ankle Brachial Index (ABI) as non-invasive tools for identifying subclinical atherosclerosis. We aim to examine the role of CIMT and ABI as predictors of the severity of angiographically documented coronary artery disease (CAD). Methods: A cross-sectional study conducted on 60 patients who were investigated by coronary angiography at Sohag University Hospital, Egypt. CIMT: After the carotid arteries were located by transverse scans, the probe was rotated 90 ° to obtain and record longitudinal images of bilateral carotid arteries ABI: Each patient was evaluated in the supine position after resting for 5 min. ABI was measured in each leg using a Doppler Ultrasound while the patient remained in the same position. The lowest ABI obtained for either leg was taken as the ABI measurement for the patient. Results: Patients with carotid mean IMT ≥ 0.9 mm had significantly more severe coronary artery disease than patients without thickening (mean IMT > 0.9 mm). Similarly, patients with low ABI (< 0.9) had significantly more severe coronary artery disease than patients with ABI ≥ 0.9. When the patients were divided into 4 groups (group A, n = 15, mean IMT < 0.9 mm, ABI ≥ 0.9; group B, n = 25, mean IMT < 0.9 mm, low ABI; group C, n = 5, mean IMT ≥ 0.9 mm, ABI ≥ 0.9; group D, n = 19, mean IMT ≤ 0.9 mm, low ABI), the presence of significant coronary stenosis (> 50%) of the groups were significantly different (group A, n = 5: (33.3%); group B, n = 11: (52.4%); group C, n = 4: (60%); group D, n=15, (78.9%), P = 0.001). Conclusion: CIMT and ABI provide useful information on the severity of CAD. Early and aggressive intervention should be considered in patients with CAD and abnormalities in one or both of these non-invasive modalities.

Keywords: ankle brachial index, carotid intima media thickness, coronary artery disease, predictors of severity

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Authors: Masek A., Diakowska K., Zaborski M.

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Polymeric materials have found their use almost in every branch of industry worldwide. Most of them constitute so-called “petropolymers" obtained from crude oil. However literature information sounds a warning that its global sources are running out. Thus, it seems that one should search for polymeric materials from renewable raw materials belonging to the group of green polymers. Therefore on account of environmental protection and the issue of sustainable technologies, nowadays greater and greater achievements have been observed in the field of green technology using engineering sciences to develop composite materials. The main aim of this study was to research what is the influence of biofillers on the properties. We used biofillers like : cellulose with different length of fiber, cellulose UFC100, silica and montmorillonite. In our research, we reported on biodegradable composites exhibitingspecificity properties by melt blending of polylactide (PLA), one of the commercially available biodegradable material, and epoxidized natural rubber (ENR) containing 50 mol.%epoxy group. Blending hydrophilic natural polymers and aliphatic polyesters is of significant interest, since it could lead to the development of a new range of biodegradable polymeric materials. We research the degradation of composites on the basis epoxidized natural rubber and poly(lactide). The addition of biofillers caused far-reaching degradation processes. The greatest resistance to biodegradation showed a montmorillonite-based mixtures, the smallest inflated cellulose fibers of varying length.The final aim in the present study is to use ENR and poly(lactide) to design composite from renewable resources with controlled degradation.

Keywords: renewable resources, biopolymer, degradation, polylactide

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Authors: Kelsey Scanlon

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Introduction: With the rate of female collegiate and professional athletes on the rise in recent decades, fluctuations in physical performance in relation to the menstrual cycle is an important area of study. PURPOSE: The purpose of this research was to compare differences in upper and lower body maximal anaerobic capacities across a single menstrual cycle. Methode: Participants (n=11) met a total of four times; once for familiarization and again on day 1 of menses (follicular phase), day 14 (ovulation), and day 21 (luteal phase) respectively. Upper body power was assessed using a bench press weight of ~50% of the participant’s predetermined 1-repetition maximum (1-RM) on a ballistic measurement system and variables included peak force (N), mean force (N), peak power (W), mean power (W), and peak velocity (m/s). Lower body power output was collected using a standard Wingate test. The variables of interest were anaerobic capacity (w/kg), peak power (W), mean power (W), fatigue index (W/s), and total work (J). Result: Statistical significance was not observed (p > 0.05) in any of the aforementioned variables after completing multiple one ways of analyses of variances (ANOVAs) with repeated measures on time. Conclusion: Within the parameters of this research, neither female upper nor lower body power output differed across the menstrual cycle when analyzed using 50% of one repetition (1RM) maximal bench press and the 30-second maximal effort cycle ergometer Wingate test. Therefore, researchers should not alter their subject populations due to the incorrect assumption that power output may be influenced by the menstrual cycle.

Keywords: anaerobic, athlete, female, power

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Authors: Ekin Nurbaş

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One of the essential challenges in array signal processing, which has drawn enormous research interest over the past several decades, is estimating the direction of arrival (DOA) of plane waves impinging on an array of sensors. In recent years, the Compressive Sensing based DoA estimation methods have been proposed by researchers, and it has been discovered that the Compressive Sensing (CS)-based algorithms achieved significant performances for DoA estimation even in scenarios where there are multiple coherent sources. On the other hand, the Genetic Algorithm, which is a method that provides a solution strategy inspired by natural selection, has been used in sparse representation problems in recent years and provides significant improvements in performance. With all of those in consideration, in this paper, a method that combines the Genetic Algorithm (GA) and the Multi-Criteria Decision Making (MCDM) approaches for Direction of Arrival (DoA) estimation in the Compressive Sensing (CS) framework is proposed. In this method, we generate a multi-objective optimization problem by splitting the norm minimization and reconstruction loss minimization parts of the Compressive Sensing algorithm. With the help of the Genetic Algorithm, multiple non-dominated solutions are achieved for the defined multi-objective optimization problem. Among the pareto-frontier solutions, the final solution is obtained with the multiple MCDM methods. Moreover, the performance of the proposed method is compared with the CS-based methods in the literature.

Keywords: genetic algorithm, direction of arrival esitmation, multi criteria decision making, compressive sensing

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Authors: Elisa Silva, Rui Lança, Fátima Farinha, Miguel José Oliveira, Manuel Duarte Pinheiro, Cátia Miguel

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Tourism is one of the global engines of development. With good planning and management, it can be a positive force, bringing benefits to touristic destinations around the world. However, without constrains, boundaries well established and constant survey, tourism can be very harmful and induce destination’s degradation. In the interest of the tourism sector and the community it is important to develop the destination maintaining its sustainability. The OBSERVE project is an instrument for monitoring and evaluating the sustainability of the region of Algarve. Its main priority is to provide environmental, economic, social-cultural and institutional indicators to support the decision-making process towards a sustainable growth. In the pursuit of the objectives, it is being developed a digital platform where the significant indicators will be continuously updated. It is known that the successful development of a touristic region depends from the careful planning with the commitment of central and regional government, industry, services and community stakeholders. Understand the different perspectives of stakeholders is essential to engage them in the development planning. However, actual stakeholders’ engagement process is complex and not easy to accomplish. To create a consistent system of indicators designed to monitor and evaluate the sustainability performance of a touristic region it is necessary to access the local data and the consideration of the full range of values and uncertainties. This paper presents the OBSERVE project and describes the stakeholders´ engagement process highlighting the contributions, ambitions and constraints.

Keywords: sustainable tourism, stakeholders' engagement, OBSERVE project, Algarve region

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Authors: Mariella Pinna

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Sustainable entrepreneurship is an innovative corporate approach to create value combining economic, social and environmental goals over time. In the last two decades, the interest in sustainable entrepreneurship has flourished thanks to its potential to answer the current challenges of sustainable development. As a result, scholars are increasingly interested in understanding the determinants of the intentions to become a sustainable entrepreneur and consistent behavior. To date, prior studies provided empirical evidence for the influence of attitudes, perceived feasibility and desirability, values, and personality traits on the decision-making process of becoming a sustainable entrepreneur. Conversely, scant effort has been provided to understand which factors inhibit sustainable entrepreneurial intentions and behaviors. Therefore a global understanding of the sustainable entrepreneurship decision-making process is missing. This paper contributes to the debate on sustainable entrepreneurship by proposing a conceptual model that combines the factors which are predicted to facilitate and hinder the proclivity of individuals to become sustainable entrepreneurs. More in particular, the proposed framework theorizes about the role of the characteristics of the prospective sustainable entrepreneur (e.g., socio-demographic, psychological, cultural), the positive antecedents (e.g., attitude, social feasibility and desirability, among others) and the negative precursors (e.g., neutralization) in influencing sustainable entrepreneurship intentions and subsequent behavior. The proposed framework is expected to shed further light on the decision-making process of becoming a sustainable entrepreneur, which in turn, is of practical relevance for public policy institutions and the society as a whole to enhance the favorable conditions to create new sustainable ventures.

Keywords: sustainable entrepreneurship, entrepreneurial intentions, entrepreneurial decision-making, antecedents of entrepreneurial intention and behavior

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Authors: Bo Zhang, Ellen S. Wilschut, Dehlia M. C. Willemsen, Marieke H. Martens

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With the rapid development of intelligent transportation systems, automated platooning of trucks is drawing increasing interest for its beneficial effects on safety, energy consumption and traffic flow efficiency. Nevertheless, one major challenge lies in the safe transition of control from the automated system back to the human drivers, especially when they have been inattentive after a long period of highly automated driving. In this study, we investigated driver take-over time after a system initiated request to leave the platooning system Virtual Tow Bar in a non-critical scenario. 22 professional truck drivers participated in the truck driving simulator experiment, and each was instructed to drive under three experimental conditions before the presentation of the take-over request (TOR): driver ready (drivers were instructed to monitor the road constantly), driver not-ready (drivers were provided with a tablet) and eye-shut. The results showed significantly longer take-over time in both driver not-ready and eye-shut conditions compared with the driver ready condition. Further analysis revealed hand movement time as the main factor causing long response time in the driver not-ready condition, while in the eye-shut condition, gaze reaction time also influenced the total take-over time largely. In addition to comparing the means, large individual differences can be found especially in two driver, not attentive conditions. The importance of a personalized driver readiness predictor for a safe transition is concluded.

Keywords: driving simulation, highly automated driving, take-over time, transition of control, truck platooning

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Authors: Abdelkader Elhanaoui, Mhamed Hadji, Rachid Skouri, Said Agounad

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The purpose of this paper is to study the phenomenon of acoustic scattering by using a new method. The signal processing (Fast Fourier Transform FFT Inverse Fast Fourier Transform iFFT and BESSEL functions) is widely applied to obtain information with high precision accuracy. Signal processing has a wider implementation in general-purpose pro-cessors. Our interest was focused on the use of FPGAs (Field-Programmable Gate Ar-rays) in order to minimize the computational complexity in single processor architecture, then be accelerated on FPGA and meet real-time and energy efficiency requirements. Gen-eral-purpose processors are not efficient for signal processing. We implemented the acous-tic backscattered signal processing model on the Altera DE-SOC board and compared it to Odroid xu4. By comparison, the computing latency of Odroid xu4 and FPGA is 60 sec-onds and 3 seconds, respectively. The detailed SoC FPGA-based system has shown that acoustic spectra are performed up to 20 times faster than the Odroid xu4 implementation. FPGA-based system of processing algorithms is realized with an absolute error of about 10⁻³. This study underlines the increasing importance of embedded systems in underwater acoustics, especially in non-destructive testing. It is possible to obtain information related to the detection and characterization of submerged cells. So we have achieved good exper-imental results in real-time and energy efficiency.

Keywords: DE1 FPGA, acoustic scattering, form function, signal processing, non-destructive testing

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Authors: Özgür Öztürk, Cumhur Sipahi, Hande Yeşil

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Implant retained restorations commonly consist of a metal-framework veneered with ceramic or composite facings. The increasing and expanding use of indirect resin composites in dentistry is a result of innovations in materials and processing techniques. Of special interest to the implant restorative field is the possibility that composites present significantly lower peak vertical and transverse forces transmitted at the peri-implant level compared to metal-ceramic supra structures in implant-supported restorations. A 43-year-old male patient referred to the department of prosthodontics for an implant retained fixed prosthesis. The clinical and radiographic examination of the patient demonstrated the presence of an implant in the right mandibular first molar tooth region. A considerable amount of marginal bone loss around the implant was detected in radiographic examinations combined with a remarkable peri-implant soft tissue deficiency. To minimize the chewing loads transmitted to the implant-bone interface it was decided to fabricate an indirect composite resin veneered single metal crown over a screw-retained abutment. At the end of the treatment, the functional and aesthetic deficiencies were fully compensated. After a 6 months clinical and radiographic follow-up period the not any additional pathologic invasion was detected in the implant-bone interface and implant retained restoration did not reveal any vehement complication.

Keywords: dental implant, fixed partial dentures, indirect composite resin, peri-implant defects

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Authors: Ahmad Ghanem, Mohamad Yasin, Mona Abdel Rehim, Fabrice Gouanve, Eliane Espuche

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Biodegradable polymers are of great interest, especially for biomedical and packaging applications. Current research efforts are focused on the development of biopolymers with the purpose of reducing the plastic pollution induced by the widely used in biodegradable polyolefins. The main challenge is focused on the elaboration of biopolymers having properties competitive to those of polyolefins. On the other hand, graphene oxide (GO), a graphene derivative, is characterized by the presence of several functional groups on the surface such as carboxylic, hydroxyl and epoxide. This feature enables modification of GO surface with different modifiers to obtain versatile surface properties and overcome the problem of graphene sheets aggregations during inclusion in a polymer matrix. In this context, poly (butylene succinate) (PBS) as promising biopolyester is modified through blending with different ratios of functionalized (GO) to improve its barrier properties. Modification of GO has been carried out using different hyperbranched polymeric structures in order to increase miscibility of the nanosheets in the hosting polymeric matrix. Films have been prepared from the modified PBS and their mechanical, thermal and gas barrier properties were investigated. The results reveal enhancement in the thermal and mechanical properties beside observed improvement of the barrier properties for the films prepared from the modified PBS. This improvement is related to the strong dependence on tortuosity effects of dispersion, exfoliation levels of fillers into the polymer matrix and interactions between the fillers and the polymer matrix.

Keywords: gas barrier properties, graphene oxide, food packaging, transport properties

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Authors: Kolela J Nyembwe, Darlington C. Ashiegbu, Herman J. Potgieter

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Over the past few decades, the demand for metals has increased significantly. This has led to a decrease and decline of high-grade ore over time and an increase in mineral complexity and matrix heterogeneity. In addition to that, there are rising concerns about greener processes and a sustainable environment. Due to these challenges, the mining and metal industry has been forced to develop new technologies that are able to economically process and recover metallic values from low-grade ores, materials having a metal content locked up in industrially processed residues (tailings and slag), and complex matrix mineral deposits. Several methods to address these issues have been developed, among which are ionic liquids (IL), heap leaching, and bioleaching. Recently, the gas phase extraction technique has been gaining interest because it eliminates many of the problems encountered in conventional mineral processing methods. The technique relies on the formation of volatile metal complexes, which can be removed from the residual solids by a carrier gas. The complexes can then be reduced using the appropriate method to obtain the metal and regenerate-recover the organic extractant. Laboratory work on the gas phase have been conducted for the extraction and recovery of aluminium (Al), iron (Fe), copper (Cu), chrome (Cr), nickel (Ni), lead (Pb), and vanadium V. In all cases the extraction revealed to depend of temperature and mineral surface area. The process technology appears very promising, offers the feasibility of recirculation, organic reagent regeneration, and has the potential to deliver on all promises of a “greener” process.

Keywords: gas-phase extraction, hydrometallurgy, low-grade ore, sustainable environment

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Authors: Saira Hossain

Abstract:

Well-being commonly refers to the concept that equates to a good life. Similarly, student well-being can be understood as a notion of a good life at school. What constitutes a good life at school for students? – is an emerging question that poses huge interest in this area of research. Student well-being is not only associated with a student’s socio-emotional and academic development at school but also success in life after school as an adult. Today, student well-being is a popular agenda for educators, policymakers, teachers, parents, and most importantly, for students. With the emergence of student well-being, student's voice in matters important to them at school is increasingly getting priority. However, the coin has another side too. Despite the growing importance of understanding student well-being, it is still an alien concept in countries like Bangladesh. The education system of Bangladesh is highly rigid, centralized, and exam-focused. Student's academic achievement has been given the utmost priority at school, whereas their voice, as well as their well-being, is grossly neglected in practice. In this regard, the study set out to explore students' conceptualization of well-being at school in Bangladesh. The study was qualitative. It employed a participatory research approach to elicit the views of 25 secondary school students of aged 14-16 in Bangladesh to explore the concept of well-being. Data analysis was conducted following the thematic analysis technique. The results suggested that student conceptualized well-being as a multidimensional concept with multiple domains, including having, being, relating, feeling, thinking, functioning, and striving. The future implication of the study findings is discussed. Additionally, the study also underscores the implication of the participatory approach as a research technique to explore students' opinion in Bangladesh, where there exists a culture of silence regarding the student's voice.

Keywords: Bangladesh, participatory research, secondary school, student well-being

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Authors: Miguel Costa

Abstract:

Despite the "time" element being an intrinsic characteristic of the work with the landscape, its execution and completion are also often dependent on external factors, i.e., the slow bureaucratic procedures required for the implementation of a project. In the urban areas of the city, these conditions are even more present — some landscape projects are articulated with the architectural/urban design, transporting itself long, expensive and inflexible processes related with the constant transformations of contemporary urban culture, where the needs and expectations could change before the project is finished. However, despite the renewed interest and growing concern for issues related to the landscapes (particularly since the European Landscape Convention, its scope and fields of action, extended to all the landscapes and not just the selected ones), still lacks the need for a greater inclusion of citizens in its protection and construction processes as well as a greater transparency and clarity of the consequences and results of their active participation. This article aims to reflect on the production processes of urban landscapes, on its completion runtime and its relationship with the citizens by introducing temporary projects as a fieldwork methodology, as well as using the contribution of different professional practices and knowledge for its monitoring, execution, and implementation. These strategies address a more interdisciplinary, transdisciplinary and performative approach, not only from the ephemeral experience of objects and actions but also from the processes and the dynamic events that are organized from these objects and actions over the landscape. The goal is to discuss the results of these approaches on its different dimensions: critical dimension; experimental and strategic dimension; pedagogical dimension; political dimension; cultural.

Keywords: landscape fieldwork, interdisciplinarity, public inclusion, public participation, temporary projects, transdisciplinarity

Procedia PDF Downloads 323