Search results for: direct displacement-based seismic design
10212 Optimization of the Production Processes of Biodiesel from a Locally Sourced Gossypium herbaceum and Moringa oleifera
Authors: Ikechukwu Ejim
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This research project addresses the optimization of biodiesel production from gossypium herbaceum (cottonseed) and moringa oleifera seeds. Soxhlet extractor method using n-hexane for gossypium herbaceum (cottonseed) and ethanol for moringa oleifera were used for solvent extraction. 1250 ml of oil was realized from both gossypium herbaceum (cottonseed) and moringa oleifera seeds before characterization. In transesterification process, a 4-factor-3-level experiment was conducted using an optimal design of Response Surface Methodology. The effects of methanol/oil molar ratio, catalyst concentration (%), temperature (°C) and time (mins), on the yield of methyl ester for both cottonseed and moringa oleifera oils were determined. The design consisted of 25 experimental runs (5 lack of fit points, five replicate points, 0 additional center points and I optimality) and provided sufficient information to fit a second-degree polynomial model. The experimental results suggested that optimum conditions were as follows; cottonseed yield (96.231%), catalyst concentration (0.972%), temperature (55oC), time (60mins) and methanol/oil molar ratios (8/1) respectively while moringa oleifera optimum values were yield (80.811%), catalyst concentration (1.0%), temperature (54.7oC), time (30mins ) and methanol/oil molar ratios (8/1) respectively. This optimized conditions were validated with the actual biodiesel yield in experimental trials and literature.Keywords: optimization, Gossypium herbaceum, Moringa oleifera, biodiesel
Procedia PDF Downloads 13610211 Assessment and Mitigation of Slope Stability Hazards Along Kombolcha-Desse Road, Northern Ethiopia
Authors: Biruk Wolde Eremacho
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The Kombolcha to Desse road, linking Addis Ababa with Northern Ethiopia towns traverses through one of the most difficult mountainous ranges in Ethiopia. The presence of loose unconsolidated materials (colluvium materials), highly weathered and fractured basalt rocks high relief, steep natural slopes, nature of geologic formations exposed along the road section, poor drainage conditions, occurrence of high seasonal rains, and seismically active nature of the region created favorable condition for slope instability in the area. Thus, keeping in mind all above points the present study was conceived to study in detail the slope stability condition of the area. It was realized that detailed slope stability studies along this road section are very necessary to identify critical slopes and to provide the best remedial measures to minimize the slope instability problems which frequently disrupt and endanger the traffic movement on this important road. For the present study based on the field manifestation of instability two most critical slope sections were identified for detailed slope stability analysis. The deterministic slope stability analysis approach was followed to perform the detailed slope stability analysis of the selected slope sections. Factor of safety for the selected slope sections was determined for the different anticipated conditions (i.e., static and dynamic with varied water saturations) using Slope/W and Slide software. Both static and seismic slope stability analysis were carried out and factor of safety was deduced for each anticipated conditions. In general, detailed slope stability analysis of the two critical slope sections reveals that for only static dry condition both the slopes sections would be stable. However, for the rest anticipated conditions defined by static and dynamic situations with varied water saturations both critical slope sections would be unstable. Moreover, the causes of slope instability in the study area are governed by different factors; therefore integrated approaches of remedial measures are more appropriate to mitigate the possible slope instability in the study area. Depending on site condition and slope stability analysis result four types of suitable preventive and remedial measures are recommended namely; proper managements of drainages, retaining structures, gabions, and managing steeply cut slopes.Keywords: factor of safety, remedial measures, slope stability analysis, static and dynamic condition
Procedia PDF Downloads 26610210 Determination of the Walkability Comfort for Urban Green Space Using Geographical Information System
Authors: Muge Unal, Cengiz Uslu, Mehmet Faruk Altunkasa
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Walkability relates to the ability of the places to connect people with varied destinations within a reasonable amount of time and effort, and to offer visual interest in journeys throughout the network. So, the good quality of the physical environment and arrangement of walkway and sidewalk appear to be more crucial in influencing the pedestrian route choice. Also, proximity, connectivity, and accessibility are significant factor for walkability in terms of an equal opportunity for using public spaces. As a result, there are two important points for walkability. Firstly, the place should have a well-planned street network for accessible and secondly facilitate the pedestrian need for comfort. In this respect, this study aims to examine the both physical and bioclimatic comfort levels of the current condition of pedestrian route with reference to design criteria of a street to access the urban green spaces. These aspects have been identified as the main indicators for walkable streets such as continuity, materials, slope, bioclimatic condition, walkway width, greenery, and surface. Additionally, the aim was to identify the factors that need to be considered in future guidelines and policies for planning and design in urban spaces especially streets. Adana city was chosen as a study area. Adana is a province of Turkey located in south-central Anatolia. This study workflow can be summarized in four stages: (1) environmental and physical data were collected by referred to literature and used in a weighted criteria method to determine the importance level of these data , (2) environmental characteristics of pedestrian routes gained from survey studies are evaluated to hierarchies these criteria of the collected information, (3) and then each pedestrian routes will have a score that provides comfortable access to the park, (4) finally, the comfortable routes to park will be mapped using GIS. It is hoped that this study will provide an insight into future development planning and design to create a friendly and more comfort street environment for the users.Keywords: comfort level, geographical information system (GIS), walkability, weighted criteria method
Procedia PDF Downloads 30210209 Interpreting Privacy Harms from a Non-Economic Perspective
Authors: Christopher Muhawe, Masooda Bashir
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With increased Internet Communication Technology(ICT), the virtual world has become the new normal. At the same time, there is an unprecedented collection of massive amounts of data by both private and public entities. Unfortunately, this increase in data collection has been in tandem with an increase in data misuse and data breach. Regrettably, the majority of data breach and data misuse claims have been unsuccessful in the United States courts for the failure of proof of direct injury to physical or economic interests. The requirement to express data privacy harms from an economic or physical stance negates the fact that not all data harms are physical or economic in nature. The challenge is compounded by the fact that data breach harms and risks do not attach immediately. This research will use a descriptive and normative approach to show that not all data harms can be expressed in economic or physical terms. Expressing privacy harms purely from an economic or physical harm perspective negates the fact that data insecurity may result into harms which run counter the functions of privacy in our lives. The promotion of liberty, selfhood, autonomy, promotion of human social relations and the furtherance of the existence of a free society. There is no economic value that can be placed on these functions of privacy. The proposed approach addresses data harms from a psychological and social perspective.Keywords: data breach and misuse, economic harms, privacy harms, psychological harms
Procedia PDF Downloads 18810208 Work-Related Risk Factors and Preventive Measures among Nurses and Dentists at Faculty of Oral and Dental Medicine
Authors: Marwa Mamdouh Shaban, Nagat Saied Habib, Shireen Ezz El-Din Taha, Eman Mahmoud Seif El-Naser
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Background: Dental nurses and dentists were constantly exposed to a number of specific work related health risk factors which develop and intensify with years. Awareness regarding these work-related health risk factors and implementation of preventive health care measures could provide a safe work environment for all dental nurses and dentists. Aim of the study: to assess the work-related health risk factors among dental nurses and dentists and preventive health care measures applied among dental nurses and dentists. Research design: A descriptive design was utilized. Sample: Convenience sample of 50 dental nurses and 150 dentists were included in the current study. Setting: This study was conducted at the dental clinics at faculty of oral and dental medicine, Al-Kasr Al Ainy Hospital. Tools of data collection: Three tools were developed, tested for clarity, and feasibility: a-Socio-demographic data sheet, b-Work-related health risk factors questionnaire, and c-structured observational checklist. Results: The most common work risk factors prevailing among dental nurses were emotional exhaustion (82%), low back pain (76%) and latex allergy (62%) and the most common work risk factors prevailing among dentists were percutaneous exposure incident (100%), emotional exhaustion (100%) and low back pain (93.3%). Also, statistically significant negative correlation (r=-0.274, at p = 0.045) between the incidence of chemical health risk factors and application of chemical preventive measures among dental nurses. A statistically significant negative correlation (r=-0.177, at p = 0.030) between the incidences of mechanical health risk factors among dentists and application of mechanical preventive measures. Conclusion: The studied dental nurses and dentists exposed to many work related health risk factors as latex allergy, percutaneous exposure incidents, low back pain and emotional exhaustion related to inappropriate application of preventive health care measures. Recommendation: Raise awareness of dental nurses and dentists about work-related health risk factors, design and implement health education program for preventive health care measures.Keywords: work-related risk factors, preventive measures, nurses, dentists
Procedia PDF Downloads 38810207 Variation of Airfoil Pressure Profile Due to Confined Air Streams: Application in Gas-Oil Separators
Authors: Amir Hossein Haji, Nabeel Al-Rawahi, Gholamreza Vakili-Nezhaad
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An innovative design has been examined for a gas-oil separator based on pressure reduction over an airfoil surface. The primary motivations are to shorten the release trajectory of the bubbles by minimizing the thickness of the oil layer as well as improving uniform pressure reduction zones. Restricted airflow over an airfoil is investigated for its effect on the pressure drop enhancement and the maximum attainable attack angle prior to the stall condition. Aerodynamic separation is delayed based on numerical simulation of Wortmann FX 63137 Airfoil in a confined domain using FLUENT 6.3.26. The proposed set up results in higher pressure drop compared with the free stream case. With the aim of optimum power consumption we have pursued further restriction to an air jet case over the airfoil. Then, a curved strip model is suggested for the air jet which can be applied as an analysis/design tool for the best performance conditions. Pressure reduction is shown to be inversely proportional to the curvature of the upper airfoil profile. This reduction occurs within the tracking zones where the air jet is effectively attached to the airfoil surface. The zero slope condition is suggested to estimate the onset of these zones after which the minimum curvature should be searched. The corresponding zero slope curvature is applied for estimation of the maximum pressure drop which shows satisfactory agreement with the simulation results.Keywords: airfoil, air jet, curved fluid flow, gas-oil separator
Procedia PDF Downloads 45910206 Cover Spalling in Reinforced Concrete Columns
Authors: Bambang Piscesa, Mario M. Attard, Dwi Presetya, Ali K. Samani
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A numerical strategy formulated using a plasticity approach is presented to model spalling of the concrete cover in reinforced concrete columns. The stage at which the concrete cover within reinforced concrete column spalls has a direct bearing on the load capacity. The concrete cover can prematurely spall before the full cross-section can be utilized if the concrete is very brittle under compression such as for very high strength concretes. If the confinement to the core is high enough, the column can achieve a higher peak load by utilizing the core. A numerical strategy is presented to model spalling of the concrete cover. Various numerical strategies are employed to model the behavior of reinforced concrete columns which include: (1) adjusting the material properties to incorporate restrained shrinkage; (2) modifying the plastic dilation rate in the presence of the tensile pressure; (3) adding a tension cut-off failure surface and (4) giving the concrete cover region and the column core different material properties. Numerical comparisons against experimental results are carried out that shown excellent agreement with the experimental results and justify the use of the proposed strategies to predict the axial load capacity of reinforce concrete columns.Keywords: spalling, concrete, plastic dilation, reinforced concrete columns
Procedia PDF Downloads 15310205 Effect of Povidone Iodine in Treatment of Epidemic Keratoconjunctivitis: Clinical Trail Study
Authors: Mohammad Hossain Validad
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Background and Aim: Epidemic keratoconjunctivitis is a type of conjunctivitis caused by adenoviruses that can spread rapidly through direct and indirect contact. The aim of this study was to evaluate the therapeutic effects of Povidone-Iodine 0.4% and 0.2% in improving the symptoms and signs of patients with epidemic keratoconjunctivitis. Materials and Methods: In this clinical trial study, 60 patients with a mean age of 27.8±8.4 years who were eligible for inclusion criteria were randomly divided into three groups. The first group received eye drops of Povidone-Iodine 0.4% and betamethasone 0.1%, the second group received PovidoneIodine 0.2% and betamethasone 0.1% and the third group received betamethasone 0.1%. Follow-ups were on the first, fourth, seventh and tenth days after starting treatment. Parameters examined at each examination were hyperaemia, mucopurulent discharge, eyelid edema, hemorrhage, and subepithelial infiltration. Results: The results showed that mucopurulent discharge on the fourth day of the examination (P = 0.005) and the seventh day of the examination (P = 0.001) were significantly different in the three treatment groups. Sub-epithelial infiltration on the tenth day after treatment did not show a significant difference in the 3 groups (P = 0.287). Conclusion: Based on the results of this study, Povidone-Iodine is more effective in relieving some of signs of EKC, such as reduced mucopurulent discharge than steroids alone.Keywords: EKC, topical bethadine, adenovirus, sub epithelial opacity
Procedia PDF Downloads 6910204 Investigation of Thickness Dependent Optical Properties of Bi₂Sb(₃-ₓ):Te ₓ (where x = 0.1, 0.2, 0.3) Thin Films
Authors: Reena Panchal, Maunik Jani, S. M. Vyas, G. R. Pandya
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Group V-VI compounds have a narrow bandgap, which makes them useful in many electronic devices. In bulk form, BiSbTe alloys are semi-metals or semi-conductors. They are used in thermoelectric and thermomagnetic devices, fabrication of ionizing, radiation detectors, LEDs, solid-state electrodes, photosensitive heterostructures, solar cells, ionic batteries, etc. Thin films of Bi₂Sb(₃-ₓ):Tex (where x = 0.1, 0.2, 0.3) of various thicknesses were grown by the thermal evaporation technique on a glass substrate at room temperature under a pressure of 10-₄ mbar for different time periods such as 10s, 15s, and 20s. The thickness of these thin films was also obtained by using the swaneopeol envelop method and compared those values with instrumental values. The optical absorption (%) data of thin films was measured in the wave number range of 650 cm-¹ to 4000 cm-¹. The band gap has been evaluated from these optical absorption data, and the results indicate that absorption occurred by a direct interband transition. It was discovered that when thickness decreased, the band gap increased; this dependency was inversely related to the square of thickness, which is explained by the quantum size effect. Using the values of bandgap, found the values of optical electronegativity (∆χ) and optical refractive index (η) using various relations.Keywords: thin films, band gap, film thickness, optical study, size effect
Procedia PDF Downloads 210203 The Design and Modeling of Intelligent Learners Assistance System (ILASS)
Authors: Jelili Kunle Adedeji, Toeb Akorede Akinbola
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The problem of vehicle mishap as a result of miscalculation, recklessness, or malfunction of some part in a vehicle is acknowledged to be a global issue. In most of the cases, it results into death or life injuries, all over the world; the issue becomes a nightmare to the stakeholders on how to curb mishaps on our roads due to these endemic factors. Hence this research typically examined the design of a device, specifically for learners that can lead to a society of intelligent vehicles (traffic) without withdrawing the driving authority from them, unlike pre-existing systems. Though ILASS shears a lot of principle with existing advance drivers assistance systems, yet there are two fundamental differences between ILASS system and existing systems. Firstly ILASS is meant to accept continuous input from the throttle at all time such that the devices will not constraint the driving process unnecessarily and ensure a change of speed at any point in time. Secondly, it made use of a variable threshold distance between the host vehicle and front vehicle which can be set by the host driver under the constraint of road maintenance agency, who communicates the minimum possible threshold for a different lane to the host vehicle. The results obtained from the simulation of the ILASS system concluded that ILASS is a good solution to road accidents, particularly road accident which occurs as a result of driving at high speed.Keywords: front-vehicle, host-speed, threshold-distance, ILASS
Procedia PDF Downloads 17110202 Large-Scale Photovoltaic Generation System Connected to HVDC Grid with Centralized High Voltage and High Power DC/DC Converter
Authors: Xinke Huang, Huan Wang, Lidong Guo, Changbin Ju, Runbiao Liu, Shanshan Meng, Yibo Wang, Honghua Xu
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Large-scale photovoltaic (PV) generation system connected to HVDC grid has many advantages compared to its counterpart of AC grid. DC connection can solve many problems that AC connection faces, such as the grid-connection and power transmission, and DC connection is the tendency. DC/DC converter as the most important device in the system has become one of the hot spots recently. The paper proposes a centralized DC/DC converter which uses Boost Full Bridge Isolated DC/DC Converter(BFBIC) topology and combination through input parallel output series(IPOS) method to improve power capacity and output voltage to match with the HVDC grid voltage. Meanwhile, it adopts input current sharing control strategy to realize input current and output voltage balance. A ±30kV/1MW system is modeled in MATLAB/SIMULINK, and a downscaled ±10kV/200kW DC/DC converter platform is built to verify the proposed topology and control strategy.Keywords: photovoltaic generation, cascaded dc/dc converter, galvanic isolation, high-voltage, direct current (HVDC)
Procedia PDF Downloads 44010201 Ultrastructure of the Tongue of the African Beauty Snake Psammophis sibilans
Authors: Mohamed M. A. Abumandour, Neveen E. R. El-Bakary
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The present work performed on the six tongues of African Beauty snake (Psammophis sibilans) that were obtained immediately after their catching, from agricultural fields, Desouk city, Kafrelsheikh Governorate, Egypt. These collected snakes should be from any oral abnormalities or injuries. The lingual surface of the Psammophis sibilans was studied by scanning electron microscopy (SEM). The surface of the bifurcated apex was smoother than the lingual body. The median lingual sulcus was deep and contained a number of the taste pores. By the high magnification of SEM of each part of a bifurcated area of the lingual apex have numerous taste buds and no lingual papillae were observed. A few numbers of papillae were observed in the lingual body. The microridges and microvilli distributed in the lingual body helped in spreading of mucus over the epithelial surface. Taste pores and papillae in the tongue indicate the presence of a direct chemo-sensory function for the tongue of these snakes as the chemicals dissolved in the mucus then transferred to Jacobson organ. To conclude, the bifurcation appearance of the snake lingual tip act as a chemical or edge detector help in the process named chemo-mechano-reception.Keywords: African beauty snake, taste buds, taste pores, tongue, papillae
Procedia PDF Downloads 11910200 Developing Problem Solving Skills through a Project-Based Course as Part of a Lifelong Learning for Engineering Students
Authors: Robin Lok Wang Ma
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The purpose of this paper is to investigate how engineering students’ motivation and interests are maintained in their journeys. In recent years, different pedagogies of teaching, including entrepreneurship, experiential and lifelong learning, as well as dream builder, etc., have been widely used for education purposes. University advocates hands-on practice, learning by experiencing and experimenting throughout different courses. Students are not limited to gaining knowledge via traditional lectures, laboratory demonstrations, tutorials, and so on. The capability to identify both complex problems and their corresponding solutions in daily life are one of the criteria/skill sets required for graduates to obtain their careers at professional organizations and companies. A project-based course, namely Mechatronic Design and Prototyping, was developed for students to design and build a physical prototype for solving existing problems in their daily lives, thereby encouraging them as an entrepreneur to explore further possibilities to commercialize their designed prototypes and launch them to the market. Feedbacks from students show that they are keen to propose their own ideas freely with guidance from the instructor instead of using either suggested or assigned topics. Proposed ideas of the prototypes reflect that if students’ interests are maintained, they acquire the knowledge and skills they need, including essential communication, logical thinking, and, more importantly, problem solving for their lifelong learning journey.Keywords: problem solving, lifelong learning, entrepreneurship, engineering
Procedia PDF Downloads 8510199 A Weighted Sum Particle Swarm Approach (WPSO) Combined with a Novel Feasibility-Based Ranking Strategy for Constrained Multi-Objective Optimization of Compact Heat Exchangers
Authors: Milad Yousefi, Moslem Yousefi, Ricarpo Poley, Amer Nordin Darus
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Design optimization of heat exchangers is a very complicated task that has been traditionally carried out based on a trial-and-error procedure. To overcome the difficulties of the conventional design approaches especially when a large number of variables, constraints and objectives are involved, a new method based on a well-stablished evolutionary algorithm, particle swarm optimization (PSO), weighted sum approach and a novel constraint handling strategy is presented in this study. Since, the conventional constraint handling strategies are not effective and easy-to-implement in multi-objective algorithms, a novel feasibility-based ranking strategy is introduced which is both extremely user-friendly and effective. A case study from industry has been investigated to illustrate the performance of the presented approach. The results show that the proposed algorithm can find the near pareto-optimal with higher accuracy when it is compared to conventional non-dominated sorting genetic algorithm II (NSGA-II). Moreover, the difficulties of a trial-and-error process for setting the penalty parameters is solved in this algorithm.Keywords: Heat exchanger, Multi-objective optimization, Particle swarm optimization, NSGA-II Constraints handling.
Procedia PDF Downloads 54910198 Sales-Based Dynamic Investment and Leverage Decisions: A Longitudinal Study
Authors: Rihab Belguith, Fathi Abid
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The paper develops a system-based approach to investigate the dynamic adjustment of debt structure and investment policies of the Dow-Jones index. This approach enables the assessment of relations among sales, debt, and investment opportunities by considering the simultaneous effect of the market environmental change and future growth opportunities. We integrate the firm-specific sales variance to capture the industries' conditions in the model. Empirical results were obtained through a panel data set of firms with different sectors. The analysis support that environmental change does not affect equally the different industry since operating leverage differs among industries and so the sensitivity to sales variance. Including adjusted-specific variance, we find that there is no monotonic relation between leverage, sales, and investment. The firm may choose a low debt level in response to high sales variance but high leverage to attenuate the negative relation between sales variance and the current level of investment. We further find that while the overall effect of debt maturity on leverage is unaffected by the level of growth opportunities, the shorter the maturity of debt is, the smaller the direct effect of sales variance on investment.Keywords: dynamic panel, investment, leverage decision, sales uncertainty
Procedia PDF Downloads 24010197 Encoding the Design of the Memorial Park and the Family Network as the Icon of 9/11 in Amy Waldman's the Submission
Authors: Masami Usui
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After 9/11, the American literary scene was confronted with new perspectives that enabled both writers and readers to recognize the hidden aspects of their political, economic, legal, social, and cultural phenomena. There appeared an argument over new and challenging multicultural aspects after 9/11 and this argument is presented by a tension of space related to 9/11. In Amy Waldman’s the Submission (2011), designing both the memorial park and the family network has a significant meaning in establishing the progress of understanding from multiple perspectives. The most intriguing and controversial topic of racism is reflected in the Submission, where one young architect’s blind entry to the competition for the memorial of Ground Zero is nominated, yet he is confronted with strong objections and hostility as soon as he turns out to be a Muslim named Mohammad Khan. This ‘Khan’ issue, immediately enlarged into a social controversial issue on American soil, causes repeated acts of hostility to Muslim women by ignorant citizens all over America. His idea of the park is to design a new concept of tracing the cultural background of the open space. Against his will, his name is identified as the ‘ingredient’ of the networking of the resistant community with his supporters: on the other hand, the post 9/11 hysteria and victimization is presented in such family associations as the Angry Family Members and Grieving Family Members. These rapidly expanding networks, whether political or not, constructed by the internet, embody the contemporary societal connection and representation. The contemporary quest for the significance of human relationships is recognized as a quest for global peace. Designing both the memorial park and the communication networks strengthens a process of facing the shared conflicts and healing the survivors’ trauma. The tension between the idea and networking of the Garden for the memorial site and the collapse of Ground Zero signifies the double mission of the site: to establish the space to ease the wounded and to remember the catastrophe. Reading the design of these icons of 9/11 in the Submission means that decoding the myth of globalization and its representations in this century.Keywords: American literature, cultural studies, globalization, literature of catastrophe
Procedia PDF Downloads 52210196 Decision Quality as an Antecedent to Export Performance. Empirical Evidence under a Contingency Theory Lens
Authors: Evagelos Korobilis-Magas, Adekunle Oke
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The constantly increasing tendency towards a global economy and the subsequent increase in exporting, as a result, has inevitably led to a growing interest in the topic of export success as well. Numerous studies, particularly in the past three decades, have examined a plethora of determinants to export performance. However, to the authors' best knowledge, no study up to date has ever considered decision quality as a potential antecedent to export success by attempting to test the relationship between decision quality and export performance. This is a surprising deficiency given that the export marketing literature has long ago suggested that quality decisions are regarded as the crucial intervening variable between sound decision–making and export performance. This study integrates the different definitions of decision quality proposed in the literature and the key themes incorporated therein and adapts it to an export context. Apart from laying the conceptual foundations for the delineation of this elusive but very important construct, this study is the first ever to test the relationship between decision quality and export performance. Based on survey data from a sample of 189 British export decision-makers and within a contingency theory framework, the results reveal that there is a direct, positive link between decision quality and export performance. This finding opens significant future research avenues and has very important implications for both theory and practice.Keywords: export performance, decision quality, mixed methods, contingency theory
Procedia PDF Downloads 8210195 Internal DC Short-Circuit Fault Analysis and Protection for VSI of Wind Power Generation Systems
Authors: Mehdi Radmehr, Amir Hamed Mashhadzadeh, Mehdi Jafari
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Traditional HVDC systems are tough to DC short circuits as they are current regulated with a large reactance connected in series with cables. Multi-terminal DC wind farm topologies are attracting increasing research attempt. With AC/DC converters on the generator side, this topology can be developed into a multi-terminal DC network for wind power collection, which is especially suitable for large-scale offshore wind farms. For wind farms, the topology uses high-voltage direct-current transmission based on voltage-source converters (VSC-HVDC). Therefore, they do not suffer from over currents due to DC cable faults and there is no over current to react to. In this study, the multi-terminal DC wind farm topology is introduced. Then, possible internal DC faults are analyzed according to type and characteristic. Fault over current expressions are given in detail. Under this characteristic analysis, fault detection and detailed protection methods are proposed. Theoretical analysis and PSCAD/EMTDC simulations are provided.Keywords: DC short circuits, multi-terminal DC wind farm topologies, HVDC transmission based on VSC, fault analysis
Procedia PDF Downloads 41710194 Bayesian Value at Risk Forecast Using Realized Conditional Autoregressive Expectiel Mdodel with an Application of Cryptocurrency
Authors: Niya Chen, Jennifer Chan
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In the financial market, risk management helps to minimize potential loss and maximize profit. There are two ways to assess risks; the first way is to calculate the risk directly based on the volatility. The most common risk measurements are Value at Risk (VaR), sharp ratio, and beta. Alternatively, we could look at the quantile of the return to assess the risk. Popular return models such as GARCH and stochastic volatility (SV) focus on modeling the mean of the return distribution via capturing the volatility dynamics; however, the quantile/expectile method will give us an idea of the distribution with the extreme return value. It will allow us to forecast VaR using return which is direct information. The advantage of using these non-parametric methods is that it is not bounded by the distribution assumptions from the parametric method. But the difference between them is that expectile uses a second-order loss function while quantile regression uses a first-order loss function. We consider several quantile functions, different volatility measures, and estimates from some volatility models. To estimate the expectile of the model, we use Realized Conditional Autoregressive Expectile (CARE) model with the bayesian method to achieve this. We would like to see if our proposed models outperform existing models in cryptocurrency, and we will test it by using Bitcoin mainly as well as Ethereum.Keywords: expectile, CARE Model, CARR Model, quantile, cryptocurrency, Value at Risk
Procedia PDF Downloads 10410193 Solar Energy Management: A Case Study of Bhubaneswar City
Authors: Rachita Lal
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Solar energy is a clean energy source. Because it is readily available in India and has many potential decentralized uses, urban local authorities may use it in various ways to manage the energy needs in the territory under their control. Apart from these and other services for which people pay a substantial number of money, urban local councils play a crucial role in administering essential services like water supply, street lighting, and health care. ULBs may contribute considerably to the transition to solar energy, both for their benefit and simultaneously for several additional direct and indirect advantages at multiple levels. The research primarily focuses on using clean energy management to reduce urban areas' reliance on traditional (electricity) energy. A technique for estimating the rooftop solar power potential using GIS (Geographical Information System) is described. Given that the combustion of fossil fuels produces 75% of India's power, meeting the country's energy needs through renewable energy sources is a step toward sustainable development and combating climate change. The study will further help in categorization, phasing, and understanding the demand and supply and thus calculating the cumulative benefits. The main objectives are to study the consumption of conventional energy in the study area and to identify the potential areas where solar photovoltaic intervention can be installed.Keywords: solar energy, GIS, clean energy management, sustainable development
Procedia PDF Downloads 7910192 Assessing the Impact of Electronic Payment Systems on the Service Delivery of Banks: Case of Nigeria
Authors: Idris lawal
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The most recent development in the Nigerian payment system is the venture into “electronic payment system”. Electronic payment system is simply a payment or monetary transaction made over the internet or a network of computers. This study was carried out in order to assess how electronic payment system has impacted on banks service delivery, to examine the efficiency of electronic payment system in Nigeria and to determine the level of customer’s satisfaction as a direct result of the deployment of electronic payment systems. The study was conducted using structured questionnaire distributed to 50 bank officials and customers of Access Bank plc. Chi-square(x2) was adopted for the purpose of data analysis. The result of the study showed that the development of electronic payment system offer great benefit to bank customers including; improved services, reduced turn-around time, ease of banking transaction, significant cost saving etc. The study recommend that customer protection laws should be properly put in place to safeguard the interest of end users of e-payment instruments, the banking industry and government should show strong commitment and effort to educate the populace on the benefit of patronizing e-payment system to facilitate economic development.Keywords: electronic payment system, service delivery, bank, Nigeria
Procedia PDF Downloads 27010191 Modeling and Minimizing the Effects of Ferroresonance for Medium Voltage Transformers
Authors: Mohammad Hossein Mohammadi Sanjani, Ashknaz Oraee, Arian Amirnia, Atena Taheri, Mohammadreza Arabi, Mahmud Fotuhi-Firuzabad
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Ferroresonance effects cause overvoltage in medium voltage transformers and isolators used in electrical networks. Ferroresonance effects are nonlinear and occur between the network capacitor and the nonlinear inductance of the voltage transformer during saturation. This phenomenon is unwanted for transformers since it causes overheating, introduction of high dynamic forces in primary coils, and rise of voltage in primary coils for the voltage transformer. Furthermore, it results in electrical and thermal failure of the transformer. Expansion of distribution lines, design of the transformer in smaller sizes, and the increase of harmonics in distribution networks result in an increase of ferroresonance. There is limited literature available to improve the effects of ferroresonance; therefore, optimizing its effects for voltage transformers is of great importance. In this study, comprehensive modeling of a medium voltage block-type voltage transformer is performed. In addition, a recent model is proposed to improve the performance of voltage transformers during the occurrence of ferroresonance using damping oscillations. Also, transformer design optimization is presented in this study to show further improvements in the performance of the voltage transformer. The recently proposed model is experimentally tested and verified on a medium voltage transformer in the laboratory, and simulation results show a large reduction of the effects of ferroresonance.Keywords: optimization, voltage transformer, ferroresonance, modeling, damper
Procedia PDF Downloads 8710190 Comparison of Entropy Coefficient and Internal Resistance of Two (Used and Fresh) Cylindrical Commercial Lithium-Ion Battery (NCR18650) with Different Capacities
Authors: Sara Kamalisiahroudi, Zhang Jianbo, Bin Wu, Jun Huang, Laisuo Su
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The temperature rising within a battery cell depends on the level of heat generation, the thermal properties and the heat transfer around the cell. The rising of temperature is a serious problem of Lithium-Ion batteries and the internal resistance of battery is the main reason for this heating up, so the heat generation rate of the batteries is an important investigating factor in battery pack design. The delivered power of a battery is directly related to its capacity, decreases in the battery capacity means the growth of the Solid Electrolyte Interface (SEI) layer which is because of the deposits of lithium from the electrolyte to form SEI layer that increases the internal resistance of the battery. In this study two identical cylindrical Lithium-Ion (NCR18650)batteries from the same company with noticeable different in capacity (a fresh and a used battery) were compared for more focusing on their heat generation parameters (entropy coefficient and internal resistance) according to Brandi model, by utilizing potentiometric method for entropy coefficient and EIS method for internal resistance measurement. The results clarify the effect of capacity difference on cell electrical (R) and thermal (dU/dT) parameters. It can be very noticeable in battery pack design for its Safety.Keywords: heat generation, Solid Electrolyte Interface (SEI), potentiometric method, entropy coefficient
Procedia PDF Downloads 45910189 Rotorcraft Performance and Environmental Impact Evaluation by Multidisciplinary Modelling
Authors: Pierre-Marie Basset, Gabriel Reboul, Binh DangVu, Sébastien Mercier
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Rotorcraft provides invaluable services thanks to their Vertical Take-Off and Landing (VTOL), hover and low speed capabilities. Yet their use is still often limited by their cost and environmental impact, especially noise and energy consumption. One of the main brakes to the expansion of the use of rotorcraft for urban missions is the environmental impact. The first main concern for the population is the noise. In order to develop the transversal competency to assess the rotorcraft environmental footprint, a collaboration has been launched between six research departments within ONERA. The progress in terms of models and methods are capitalized into the numerical workshop C.R.E.A.T.I.O.N. “Concepts of Rotorcraft Enhanced Assessment Through Integrated Optimization Network”. A typical mission for which the environmental impact issue is of great relevance has been defined. The first milestone is to perform the pre-sizing of a reference helicopter for this mission. In a second milestone, an alternate rotorcraft concept has been defined: a tandem rotorcraft with optional propulsion. The key design trends are given for the pre-sizing of this rotorcraft aiming at a significant reduction of the global environmental impact while still giving equivalent flight performance and safety with respect to the reference helicopter. The models and methods have been improved for catching sooner and more globally, the relative variations on the environmental impact when changing the rotorcraft architecture, the pre-design variables and the operation parameters.Keywords: environmental impact, flight performance, helicopter, multi objectives multidisciplinary optimization, rotorcraft
Procedia PDF Downloads 26010188 Design and Realization of Computer Network Security Perception Control System
Authors: El Miloudi Djelloul
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Based on analysis on applications by perception control technology in computer network security status and security protection measures, from the angles of network physical environment and network software system environmental security, this paper provides network security system perception control solution using Internet of Things (IOT), telecom and other perception technologies. Security Perception Control System is in the computer network environment, utilizing Radio Frequency Identification (RFID) of IOT and telecom integration technology to carry out integration design for systems. In the network physical security environment, RFID temperature, humidity, gas and perception technologies are used to do surveillance on environmental data, dynamic perception technology is used for network system security environment, user-defined security parameters, security log are used for quick data analysis, extends control on I/O interface, by development of API and AT command, Computer Network Security Perception Control based on Internet and GSM/GPRS is achieved, which enables users to carry out interactive perception and control for network security environment by WEB, E-MAIL as well as PDA, mobile phone short message and Internet. In the system testing, through middle ware server, security information data perception in real time with deviation of 3-5% was achieved; it proves the feasibility of Computer Network Security Perception Control System.Keywords: computer network, perception control system security strategy, Radio Frequency Identification (RFID)
Procedia PDF Downloads 43910187 Hand Gesture Interpretation Using Sensing Glove Integrated with Machine Learning Algorithms
Authors: Aqsa Ali, Aleem Mushtaq, Attaullah Memon, Monna
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In this paper, we present a low cost design for a smart glove that can perform sign language recognition to assist the speech impaired people. Specifically, we have designed and developed an Assistive Hand Gesture Interpreter that recognizes hand movements relevant to the American Sign Language (ASL) and translates them into text for display on a Thin-Film-Transistor Liquid Crystal Display (TFT LCD) screen as well as synthetic speech. Linear Bayes Classifiers and Multilayer Neural Networks have been used to classify 11 feature vectors obtained from the sensors on the glove into one of the 27 ASL alphabets and a predefined gesture for space. Three types of features are used; bending using six bend sensors, orientation in three dimensions using accelerometers and contacts at vital points using contact sensors. To gauge the performance of the presented design, the training database was prepared using five volunteers. The accuracy of the current version on the prepared dataset was found to be up to 99.3% for target user. The solution combines electronics, e-textile technology, sensor technology, embedded system and machine learning techniques to build a low cost wearable glove that is scrupulous, elegant and portable.Keywords: American sign language, assistive hand gesture interpreter, human-machine interface, machine learning, sensing glove
Procedia PDF Downloads 29110186 A Study of Transferable Strategies in Multilanguage Learning
Authors: Zixi You
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With the demand of multilingual speakers increasing in the job market, multi-language learning programs have become more and more popular among undergraduate students. A study on multi-language learning strategies is therefore highly demanded on both practical and theoretical levels. Based on previous classification of learning strategies in SLA, and an investigation of BA Modern Language program students (with post-A level L2 and ab initio L3 learning experience from year one), this study explores and compares different types of learning strategies used by multi-language speakers and learners, transferable learning strategies between L2 and L3, and factors affecting the transfer. The results indicate that all the 23 types of learning strategies of L2 are employed when learning L3 from ab initio level, yet with different tendencies. Learning strategy transfer from L2 to L3 (i.e., the learners attribute the applying of these L3 learning strategies to be a direct result of their L2 learning experience) are observed in all 23 types of learning strategies. Comparatively, six types of “cognitive strategies” have higher transfer tendency than others. With regard to the failure of the transfer of some particular L2 strategies and the development of independent L3 strategies of individual learners, factors such as language proficiency, language typology and learning environment have played important roles among others. The presentation of this study will provide audiences with detailed data, insightful analysis and discussion on both theoretical and practical aspects of multi-language learning that will benefit both students and educators.Keywords: learning strategy, multi-language acquisition, second language acquisition, strategy transfer
Procedia PDF Downloads 56910185 The Global Language Teaching Spots to Accelerate Globalization and Equitable Economic Development Worldwide
Authors: Setyo Pamuji
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The basis of this research is to create an international business project by developing an area in every country which focused on global language teaching to accelerate huge project of internationalization for mankind better with equity. It is to make an ease, learning more effective and efficient as well as economic development significantly at the place. Some have attempted to establish it, but could have not succeeded. This study uses stratified random sampling method to determine respondents. It is caused by population coming from around of Indonesia which is heterogeneity. Above all, researcher has already known well the spot including the mapping of students and societies, over 5-year, from beginning studying English (2011) until teaching English (2015). This quantitative research is able to analyze the vital factor of successful Language Village at Pare, Kediri, East Java, Indonesia which has never been obtained anywhere. This project provides valuable information regarding management used by the Language Village. Overall approach depicts vigorous marketing strategy and dedication blended. This will allow for more individual consideration of economist and may direct future research on the uniqueness of the Language Village to ascertain more profound understanding of the village which succeeds inviting people from other places to come, beside formal management and marketing.Keywords: internationalization, accelerate, global language, economic development, blended, globalization
Procedia PDF Downloads 16910184 De Novo Design of a Minimal Catalytic Di-Nickel Peptide Capable of Sustained Hydrogen Evolution
Authors: Saroj Poudel, Joshua Mancini, Douglas Pike, Jennifer Timm, Alexei Tyryshkin, Vikas Nanda, Paul Falkowski
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On the early Earth, protein-metal complexes likely harvested energy from a reduced environment. These complexes would have been precursors to the metabolic enzymes of ancient organisms. Hydrogenase is an essential enzyme in most anaerobic organisms for the reduction and oxidation of hydrogen in the environment and is likely one of the earliest evolved enzymes. To attempt to reinvent a precursor to modern hydrogenase, we computationally designed a short thirteen amino acid peptide that binds the often-required catalytic transition metal Nickel in hydrogenase. This simple complex can achieve hundreds of hydrogen evolution cycles using light energy in a broad range of temperature and pH. Biophysical and structural investigations strongly indicate the peptide forms a di-nickel active site analogous to Acetyl-CoA synthase, an ancient protein central to carbon reduction in the Wood-Ljungdahl pathway and capable of hydrogen evolution. This work demonstrates that prior to the complex evolution of multidomain enzymes, early peptide-metal complexes could have catalyzed energy transfer from the environment on the early Earth and enabled the evolution of modern metabolismKeywords: hydrogenase, prebiotic enzyme, metalloenzyme, computational design
Procedia PDF Downloads 20910183 Crack Initiation Assessment during Fracture of Heat Treated Duplex Stainless Steels
Authors: Faraj Ahmed E. Alhegagi, Anagia M. Khamkam Mohamed, Bassam F. Alhajaji
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Duplex stainless steels (DSS) are widely employed in industry for apparatus working with sea water in petroleum, refineries and in chemical plants. Fracture of DSS takes place by cleavage of the ferrite phase and the austenite phase ductile tear off. Pop-in is an important feature takes place during fracture of DSS. The procedure of Pop-ins assessment plays an important role in fracture toughness studies. In present work, Zeron100 DSS specimens were heat treated at different temperatures, cooled and pulled to failure to assess the pop-ins criterion in crack initiation prediction. The outcome results were compared to the British Standard (BS 7448) and the ASTEM standard (E1290) for Crack-Tip Opening Displacement (CTOD) fracture toughness measurement. Pop-in took place during specimens loading specially for those specimens heat treated at higher temperatures. The standard BS7448 was followed to check specimen validity for fractured toughness assessment by direct determination of KIC. In most cases, specimens were invalid for KIC measurement. The two procedures were equivalent only when single pop-ins were assessed. A considerable contrast in fracture toughness value between was observed where multiple pop-ins were assessed.Keywords: fracture toughness, stainless steels, pop ins, crack assessment
Procedia PDF Downloads 115