Search results for: safety situation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5737

Search results for: safety situation

1597 Technical Sustainable Management: An Instrument to Increase Energy Efficiency in Wastewater Treatment Plants, a Case Study in Jordan

Authors: Dirk Winkler, Leon Koevener, Lamees AlHayary

Abstract:

This paper contributes to the improvement of the municipal wastewater systems in Jordan. An important goal is increased energy efficiency in wastewater treatment plants and therefore lower expenses due to reduced electricity consumption. The chosen way to achieve this goal is through the implementation of Technical Sustainable Management adapted to the Jordanian context. Three wastewater treatment plants in Jordan have been chosen as a case study for the investigation. These choices were supported by the fact that the three treatment plants are suitable for average performance and size. Beyond that, an energy assessment has been recently conducted in those facilities. The project succeeded in proving the following hypothesis: Energy efficiency in wastewater treatment plants can be improved by implementing principles of Technical Sustainable Management adapted to the Jordanian context. With this case study, a significant increase in energy efficiency can be achieved by optimization of operational performance, identifying and eliminating shortcomings and appropriate plant management. Implementing Technical Sustainable Management as a low-cost tool with a comparable little workload, provides several additional benefits supplementing increased energy efficiency, including compliance with all legal and technical requirements, process optimization, but also increased work safety and convenient working conditions. The research in the chosen field continues because there are indications for possible integration of the adapted tool into other regions and sectors. The concept of Technical Sustainable Management adapted to the Jordanian context could be extended to other wastewater treatment plants in all regions of Jordan but also into other sectors including water treatment, water distribution, wastewater network, desalination, or chemical industry.

Keywords: energy efficiency, quality management system, technical sustainable management, wastewater treatment

Procedia PDF Downloads 164
1596 Numerical Modeling of Film Cooling of the Surface at Non-Uniform Heat Flux Distributions on the Wall

Authors: M. V. Bartashevich

Abstract:

The problem of heat transfer at thin laminar liquid film is solved numerically. A thin film of liquid flows down an inclined surface under conditions of variable heat flux on the wall. The use of thin films of liquid allows to create the effective technologies for cooling surfaces. However, it is important to investigate the most suitable cooling regimes from a safety point of view, in order, for example, to avoid overheating caused by the ruptures of the liquid film, and also to study the most effective cooling regimes depending on the character of the distribution of the heat flux on the wall, as well as the character of the blowing of the film surface, i.e., the external shear stress on its surface. In the statement of the problem on the film surface, the heat transfer coefficient between the liquid and gas is set, as well as a variable external shear stress - the intensity of blowing. It is shown that the combination of these factors - the degree of uniformity of the distribution of heat flux on the wall and the intensity of blowing, affects the efficiency of heat transfer. In this case, with an increase in the intensity of blowing, the cooling efficiency increases, reaching a maximum, and then decreases. It is also shown that the more uniform the heating of the wall, the more efficient the heat sink. A separate study was made for the flow regime along the horizontal surface when the liquid film moves solely due to external stress influence. For this mode, the analytical solution is used for the temperature at the entrance region for further numerical calculations downstream. Also the influence of the degree of uniformity of the heat flux distribution on the wall and the intensity of blowing of the film surface on the heat transfer efficiency was also studied. This work was carried out at the Kutateladze Institute of Thermophysics SB RAS (Russia) and supported by FASO Russia.

Keywords: Heat Flux, Heat Transfer Enhancement, External Blowing, Thin Liquid Film

Procedia PDF Downloads 150
1595 The Role of Situational Factors in User Experience during Human-Robot Interaction

Authors: Da Tao, Tieyan Wang, Mingfu Qin

Abstract:

While social robots have been increasingly developed and rapidly applied in our daily life, how robots should interact with humans is still an urgent problem to be explored. Appropriate use of interactive behavior is likely to create a good user experience in human-robot interaction situations, which in turn can improve people’s acceptance of robots. This paper aimed to systematically and quantitatively examine the effects of several important situational factors (i.e., interaction distance, interaction posture, and feedback style) on user experience during human-robot interaction. A three-factor mixed designed experiment was adopted in this study, where subjects were asked to interact with a social robot in different interaction situations by combinations of varied interaction distance, interaction posture, and feedback style. A set of data on users’ behavioral performance, subjective perceptions, and eye movement measures were tracked and collected, and analyzed by repeated measures analysis of variance. The results showed that the three situational factors showed no effects on behavioral performance in tasks during human-robot interaction. Interaction distance and feedback style yielded significant main effects and interaction effects on the proportion of fixation times. The proportion of fixation times on the robot is higher for negative feedback compared with positive feedback style. While the proportion of fixation times on the robot generally decreased with the increase of the interaction distance, it decreased more under the positive feedback style than under the negative feedback style. In addition, there were significant interaction effects on pupil diameter between interaction distance and posture. As interaction distance increased, mean pupil diameter became smaller in side interaction, while it became larger in frontal interaction. Moreover, the three situation factors had significant interaction effects on user acceptance of the interaction mode. The findings are helpful in the underlying mechanism of user experience in human-robot interaction situations and provide important implications for the design of robot behavioral expression and for optimal strategies to improve user experience during human-robot interaction.

Keywords: social robots, human-robot interaction, interaction posture, interaction distance, feedback style, user experience

Procedia PDF Downloads 133
1594 System Dietadhoc® - A Fusion of Human-Centred Design and Agile Development for the Explainability of AI Techniques Based on Nutritional and Clinical Data

Authors: Michelangelo Sofo, Giuseppe Labianca

Abstract:

In recent years, the scientific community's interest in the exploratory analysis of biomedical data has increased exponentially. Considering the field of research of nutritional biologists, the curative process, based on the analysis of clinical data, is a very delicate operation due to the fact that there are multiple solutions for the management of pathologies in the food sector (for example can recall intolerances and allergies, management of cholesterol metabolism, diabetic pathologies, arterial hypertension, up to obesity and breathing and sleep problems). In this regard, in this research work a system was created capable of evaluating various dietary regimes for specific patient pathologies. The system is founded on a mathematical-numerical model and has been created tailored for the real working needs of an expert in human nutrition using the human-centered design (ISO 9241-210), therefore it is in step with continuous scientific progress in the field and evolves through the experience of managed clinical cases (machine learning process). DietAdhoc® is a decision support system nutrition specialists for patients of both sexes (from 18 years of age) developed with an agile methodology. Its task consists in drawing up the biomedical and clinical profile of the specific patient by applying two algorithmic optimization approaches on nutritional data and a symbolic solution, obtained by transforming the relational database underlying the system into a deductive database. For all three solution approaches, particular emphasis has been given to the explainability of the suggested clinical decisions through flexible and customizable user interfaces. Furthermore, the system has multiple software modules based on time series and visual analytics techniques that allow to evaluate the complete picture of the situation and the evolution of the diet assigned for specific pathologies.

Keywords: medical decision support, physiological data extraction, data driven diagnosis, human centered AI, symbiotic AI paradigm

Procedia PDF Downloads 26
1593 Design and Thermal Analysis of Power Harvesting System of a Hexagonal Shaped Small Spacecraft

Authors: Mansa Radhakrishnan, Anwar Ali, Muhammad Rizwan Mughal

Abstract:

Many universities around the world are working on modular and low budget architecture of small spacecraft to reduce the development cost of the overall system. This paper focuses on the design of a modular solar power harvesting system for a hexagonal-shaped small satellite. The designed solar power harvesting systems are composed of solar panels and power converter subsystems. The solar panel is composed of solar cells mounted on the external face of the printed circuit board (PCB), while the electronic components of power conversion are mounted on the interior side of the same PCB. The solar panel with dimensions 16.5cm × 99cm is composed of 36 solar cells (each solar cell is 4cm × 7cm) divided into four parallel banks where each bank consists of 9 solar cells. The output voltage of a single solar cell is 2.14V, and the combined output voltage of 9 series connected solar cells is around 19.3V. The output voltage of the solar panel is boosted to the satellite power distribution bus voltage level (28V) by a boost converter working on a constant voltage maximum power point tracking (MPPT) technique. The solar panel module is an eight-layer PCB having embedded coil in 4 internal layers. This coil is used to control the attitude of the spacecraft, which consumes power to generate a magnetic field and rotate the spacecraft. As power converter and distribution subsystem components are mounted on the PCB internal layer, therefore it is mandatory to do thermal analysis in order to ensure that the overall module temperature is within thermal safety limits. The main focus of the overall design is on compactness, miniaturization, and efficiency enhancement.

Keywords: small satellites, power subsystem, efficiency, MPPT

Procedia PDF Downloads 77
1592 An Exploratory Study to Understand the Economic Opportunities from Climate Change

Authors: Sharvari Parikh

Abstract:

Climate change has always been looked upon as a threat. Increased use of fossil fuels, depletion of bio diversity, certain human activities, rising levels of Greenhouse Gas (GHG) emissions are the factors that have caused climate change. Climate change is creating new risks and aggravating the existing ones. The paper focuses on breaking the stereotypical perception of climate change and draws attention towards the constructive side of it. Researches around the world have concluded that climate change has provided us with many untapped opportunities. The next 15 years will be crucial, as it is in our hands whether we are able to grab these opportunities or just let the situation get worse. The world stands at a stage where we cannot think of making a choice between averting climate change and promoting growth and development. In fact, the solution to climate change itself has got economic opportunities. The data evidences from the paper show how we can create the opportunity to improve the lives of the world’s population at large through structural change which will promote environment friendly investments. Rising Investment in green energy and increased demand of climate friendly products has got ample of employment opportunities. Old technologies and machinery which are employed today lack efficiency and demand huge maintenance because of which we face high production cost. This can be drastically brought down by adaptation of Green technologies which are more accessible and affordable. Overall GDP of the world has been heavily affected in aggravating the problems arising out of increasing weather problems. Shifting to green economy can not only eliminate these costs but also build a sound economy. Accelerating the economy in direction of low-carbon future can lessen the burdens such as subsidies for fossil fuels, several public debts, unemployment, poverty, reduce healthcare expenses etc. It is clear that the world will be dragged into the ‘Darker phase’ if the current trends of fossil fuels and carbon are being consumed. Switching to Green economy is the only way in which we can lift the world from darker phase. Climate change has opened the gates for ‘Green and Clean economy’. It will also bring countries of the world together in achieving the common goal of Green Economy.

Keywords: climate change, economic opportunities, green economy, green technology

Procedia PDF Downloads 244
1591 Simulation of the FDA Centrifugal Blood Pump Using High Performance Computing

Authors: Mehdi Behbahani, Sebastian Rible, Charles Moulinec, Yvan Fournier, Mike Nicolai, Paolo Crosetto

Abstract:

Computational Fluid Dynamics blood-flow simulations are increasingly used to develop and validate blood-contacting medical devices. This study shows that numerical simulations can provide additional and accurate estimates of relevant hemodynamic indicators (e.g., recirculation zones or wall shear stresses), which may be difficult and expensive to obtain from in-vivo or in-vitro experiments. The most recent FDA (Food and Drug Administration) benchmark consisted of a simplified centrifugal blood pump model that contains fluid flow features as they are commonly found in these devices with a clear focus on highly turbulent phenomena. The FDA centrifugal blood pump study is composed of six test cases with different volumetric flow rates ranging from 2.5 to 7.0 liters per minute, pump speeds, and Reynolds numbers ranging from 210,000 to 293,000. Within the frame of this study different turbulence models were tested including RANS models, e.g. k-omega, k-epsilon and a Reynolds Stress Model (RSM) and, LES. The partitioners Hilbert, METIS, ParMETIS and SCOTCH were used to create an unstructured mesh of 76 million elements and compared in their efficiency. Computations were performed on the JUQUEEN BG/Q architecture applying the highly parallel flow solver Code SATURNE and typically using 32768 or more processors in parallel. Visualisations were performed by means of PARAVIEW. Different turbulence models including all six flow situations could be successfully analysed and validated against analytical considerations and from comparison to other data-bases. It showed that an RSM represents an appropriate choice with respect to modeling high-Reynolds number flow cases. Especially, the Rij-SSG (Speziale, Sarkar, Gatzki) variant turned out to be a good approach. Visualisation of complex flow features could be obtained and the flow situation inside the pump could be characterized.

Keywords: blood flow, centrifugal blood pump, high performance computing, scalability, turbulence

Procedia PDF Downloads 382
1590 Patterns of Occurrence of Bovine Haemoparasitic Diseases and Its Co-Incidence with Viral Epidemics of Foot and Mouth Disease and Lumpy Skin Disease

Authors: Amir Hamed Abd-Elrahman, Mohamed Bessat

Abstract:

450 fattening cattle and buffaloes aged from 6 to 30 months old were examined clinically to determine patterns of occurrence of hemoparasitic diseases and the efficacy of different anti theilerial drugs. 420 animals examined clinically to determine relation between different outbreak of FMD and LSD in Egypt 2012- 2013 and haemoprotozoal diseases. The clinical pictures of haemoprotozoal diseases are variable, from sever to mild, depending on the endemic situation which governed by frequent previous exposure and tick infestation. B. bigemina is the most common haemoprotozoal diseases in the area of study and the infection rate in a descending manner for B. bigemina, A. marginale and T. annulata were 20%, 9.7% and 6.6% respectively. The species susceptibility of B. bigemina and T. annulata showed a higher incidence in cattle than buffaloes while in A. marginale showed a little difference in cattle and buffaloes susceptibility by 10% and 9.2% respectively. The breed susceptibility of B. bigemina and T. annulata showed a higher incidence in crossbred cattle than native baladi cattle while A. marginale showed a higher incidence in native baladi cattle than crossbred cattle. The maximal infection rates were recorded during summer months. The infection rates of B. bigemina and A. marginale were higher among young animals over 6 months and declined above 2 year old while in T. annulata the infection rates were lower among young animals and increased above 2 year old. The case fatality of T. annulata was higher than A. marginale and B. bigemina. Efficacy of different anti theilerial drugs were studied, cure rate of chlouroquine group and Butalex group were 60% disappearance of schizont in lymph node smear after 9 days and 5 days respectively while cure rate of Oxytetracycline Dihydrate (Alamycine) group 20% with disappearance of schizont in lymph node smear after 14 days. FMD and LSD infection enhancement the occurrence of bovine haemoprotozoal diseases.

Keywords: Babesia bigemina, Anaplasma marginale, Theileria annulata, FMD, LSD, ephemeral fever

Procedia PDF Downloads 330
1589 Improving Electrical Safety through Enhanced Work Permits

Authors: Nuwan Karunarathna, Hemali Seneviratne

Abstract:

Distribution Utilities inherently present electrical hazards for their workers in addition to the general public especially due to bare overhead lines spreading out over a large geographical area. Therefore, certain procedures such as; de-energization, verification of de-energization, isolation, lock-out tag-out and earthing are carried out to ensure safe working conditions when conducting maintenance work on de-energized overhead lines. However, measures must be taken to coordinate the above procedures and to ensure successful and accurate execution of those procedures. Issuing of 'Work Permits' is such a measure that is used by the Distribution Utility considered in this paper. Unfortunately, the Work Permit method adopted by the Distribution Utility concerned here has not been successful in creating the safe working conditions as expected which was evidenced by four (4) number of fatalities of workers due to electrocution occurred in the Distribution Utility from 2016 to 2018. Therefore, this paper attempts to identify deficiencies in the Work Permit method and related contributing factors through careful analysis of the four (4) fatalities and work place practices to rectify the short comings to prevent future incidents. The analysis shows that the present level of coordination between the 'Authorized Person' who issues the work permit and the 'Competent Person' who performs the actual work is grossly inadequate to achieve the intended safe working conditions. The paper identifies the need of active participation of a 'Control Person' who oversees the whole operation from a bird’s eye perspective and recommends further measures that are derived through the analysis of the fatalities to address the identified lapses in the current work permit system.

Keywords: authorized person, competent person, control person, de-energization, distribution utility, isolation, lock-out tag-out, overhead lines, work permit

Procedia PDF Downloads 133
1588 Research on Intercity Travel Mode Choice Behavior Considering Traveler’s Heterogeneity and Psychological Latent Variables

Authors: Yue Huang, Hongcheng Gan

Abstract:

The new urbanization pattern has led to a rapid growth in demand for short-distance intercity travel, and the emergence of new travel modes has also increased the variety of intercity travel options. In previous studies on intercity travel mode choice behavior, the impact of functional amenities of travel mode and travelers’ long-term personality characteristics has rarely been considered, and empirical results have typically been calibrated using revealed preference (RP) or stated preference (SP) data. This study designed a questionnaire that combines the RP and SP experiment from the perspective of a trip chain combining inner-city and intercity mobility, with consideration for the actual condition of the Huainan-Hefei traffic corridor. On the basis of RP/SP fusion data, a hybrid choice model considering both random taste heterogeneity and psychological characteristics was established to investigate travelers’ mode choice behavior for traditional train, high-speed rail, intercity bus, private car, and intercity online car-hailing. The findings show that intercity time and cost exert the greatest influence on mode choice, with significant heterogeneity across the population. Although inner-city cost does not demonstrate a significant influence, inner-city time plays an important role. Service attributes of travel mode, such as catering and hygiene services, as well as free wireless network supply, only play a minor role in mode selection. Finally, our study demonstrates that safety-seeking tendency, hedonism, and introversion all have differential and significant effects on intercity travel mode choice.

Keywords: intercity travel mode choice, stated preference survey, hybrid choice model, RP/SP fusion data, psychological latent variable, heterogeneity

Procedia PDF Downloads 111
1587 Sensor and Actuator Fault Detection in Connected Vehicles under a Packet Dropping Network

Authors: Z. Abdollahi Biron, P. Pisu

Abstract:

Connected vehicles are one of the promising technologies for future Intelligent Transportation Systems (ITS). A connected vehicle system is essentially a set of vehicles communicating through a network to exchange their information with each other and the infrastructure. Although this interconnection of the vehicles can be potentially beneficial in creating an efficient, sustainable, and green transportation system, a set of safety and reliability challenges come out with this technology. The first challenge arises from the information loss due to unreliable communication network which affects the control/management system of the individual vehicles and the overall system. Such scenario may lead to degraded or even unsafe operation which could be potentially catastrophic. Secondly, faulty sensors and actuators can affect the individual vehicle’s safe operation and in turn will create a potentially unsafe node in the vehicular network. Further, sending that faulty sensor information to other vehicles and failure in actuators may significantly affect the safe operation of the overall vehicular network. Therefore, it is of utmost importance to take these issues into consideration while designing the control/management algorithms of the individual vehicles as a part of connected vehicle system. In this paper, we consider a connected vehicle system under Co-operative Adaptive Cruise Control (CACC) and propose a fault diagnosis scheme that deals with these aforementioned challenges. Specifically, the conventional CACC algorithm is modified by adding a Kalman filter-based estimation algorithm to suppress the effect of lost information under unreliable network. Further, a sliding mode observer-based algorithm is used to improve the sensor reliability under faults. The effectiveness of the overall diagnostic scheme is verified via simulation studies.

Keywords: fault diagnostics, communication network, connected vehicles, packet drop out, platoon

Procedia PDF Downloads 239
1586 Research on the Renewal and Utilization of Space under the Bridge in Chongqing Based on Spatial Potential Evaluation

Authors: Xvelian Qin

Abstract:

Urban "organic renewal" based on the development of existing resources in high-density urban areas has become the mainstream of urban development in the new era. As an important stock resource of public space in high-density urban areas, promoting its value remodeling is an effective way to alleviate the shortage of public space resources. However, due to the lack of evaluation links in the process of underpass space renewal, a large number of underpass space resources have been left idle, facing the problems of low space conversion efficiency, lack of accuracy in development decision-making, and low adaptability of functional positioning to citizens' needs. Therefore, it is of great practical significance to construct the evaluation system of under-bridge space renewal potential and explore the renewal mode. In this paper, some of the under-bridge spaces in the main urban area of Chongqing are selected as the research object. Through the questionnaire interviews with the users of the built excellent space under the bridge, three types of six levels and twenty-two potential evaluation indexes of "objective demand factor, construction feasibility factor and construction suitability factor" are selected, including six levels of land resources, infrastructure, accessibility, safety, space quality and ecological environment. The analytical hierarchy process and expert scoring method are used to determine the index weight, construct the potential evaluation system of the space under the bridge in high-density urban areas of Chongqing, and explore the direction of renewal and utilization of its suitability. To provide feasible theoretical basis and scientific decision support for the use of under bridge space in the future.

Keywords: high density urban area, potential evaluation, space under bridge, updated using

Procedia PDF Downloads 71
1585 [Keynote Talk]: Quest for Sustainability in the Midst of Conflict Between Climate and Energy Security

Authors: Deepak L. Waikar

Abstract:

Unprecedented natural as well as human made disasters have been responsible for loss of hundreds of thousands of lives, injury & displacement of millions of people and damages in billions of dollars in various parts of the world. Scientists, experts, associations and united nation have been warning about colossal disregard for human safety and environment in exploiting natural resources for insatiable greed for economic growth and rising lavish life style of the rich. Usual blame game is routinely played at international forums & summits by vested interests in developing and developed nations, while billions of people continue to suffer in abject energy poverty. Energy security, on the other hand, is becoming illusive with the dominance of few players in the market, poor energy governance mechanisms, volatile prices and geopolitical conflicts in supply chain. Conflicting scenarios have been cited as one of the major barriers for transformation to a low carbon economy. Policy makers, researchers, academics, businesses, industries and communities have been evaluating sustainable alternatives, albeit at snail’s pace. This presentation focuses on technologies, energy governance, policies & practices, economics and public concerns about safe, prudent & sustainable harnessing of energy resources. Current trends and potential research & development projects in power & energy sectors which students can undertake will be discussed. Speaker will highlight on how youths can be engaged in meaningful, safe, enriching, inspiring and value added self-development programmes in our quest for sustainability in the midst of conflict between climate and energy security.

Keywords: clean energy, energy policy, energy security, sustainable energy

Procedia PDF Downloads 488
1584 Heavy Metal Contents in Vegetable Oils of Kazakhstan Origin and Life Risk Assessment

Authors: A. E. Mukhametov, M. T. Yerbulekova, D. R. Dautkanova, G. A. Tuyakova, G. Aitkhozhayeva

Abstract:

The accumulation of heavy metals in food is a constant problem in many parts of the world. Vegetable oils are widely used, both for cooking and for processing in the food industry, meeting the main dietary requirements. One of the main chemical pollutants, heavy metals, is usually found in vegetable oils. These chemical pollutants are carcinogenic, teratogenic and immunotoxic, harmful to consumption and have a negative effect on human health even in trace amounts. Residues of these substances can easily accumulate in vegetable oil during cultivation, processing and storage. In this article, the content of the concentration of heavy metal ions in vegetable oils of Kazakhstan production is studied: sunflower, rapeseed, safflower and linseed oil. Heavy metals: arsenic, cadmium, lead and nickel, were determined in three repetitions by the method of flame atomic absorption. Analysis of vegetable oil samples revealed that the largest lead contamination (Pb) was determined to be 0.065 mg/kg in linseed oil. The content of cadmium (Cd) in the largest amount of 0.009 mg/kg was found in safflower oil. Arsenic (As) content was determined in rapeseed and safflower oils at 0.003 mg/kg, and arsenic (As) was not detected in linseed and sunflower oil. The nickel (Ni) content in the largest amount of 0.433 mg/kg was in linseed oil. The heavy metal contents in the test samples complied with the requirements of regulatory documents for vegetable oils. An assessment of the health risk of vegetable oils with a daily consumption of 36 g per day shows that all samples of vegetable oils produced in Kazakhstan are safe for consumption. But further monitoring is needed, since all these metals are toxic and their harmful effects become apparent only after several years of exposure.

Keywords: vegetable oil, sunflower oil, linseed oil, safflower oil, toxic metals, food safety, rape oil

Procedia PDF Downloads 134
1583 Reconstruction of Complex Post Oncologic Maxillectomy Defects

Authors: Vinay Kant Shankhdhar

Abstract:

Purpose: Maxillary defects are three dimensional and require complex bone and soft tissue reconstruction. Maxillary reconstruction using fibula osteocutaneous flaps in situation requiring orbital floor, orbital wall, palatal defects, and external skin, all at the same time require special planning and multiple osteotomies. We tried to improvise our reconstruction using multiple osteotomies and skin paddle designs for fibula and Flexor Hallucis Longus Muscle. This study aims at discussing the planning and outcome in complex maxillary reconstructions using fibula flaps and soft tissue flaps with or without bone grafts. Material and Methods: From 2011 to 2017 a total of 129 Free fibula flaps were done, 67 required two or more struts, 164 Anterolateral Thigh Flaps, 11 Deep Inferior Epigastric Artery perforator flaps and 3 vertical rectus abdominis muscle flaps with iliac crest bone graft. The age range was 2 to 70 years. The reconstruction was evaluated based on the post-operative rehabilitation including orbital support (prevention of diplopia), oral diet, speech and cosmetic appearance. Results: The follow- up is from 5 years to 1 year. In this series, we observed that the common complications were the de-vascularisation of most distal segment of osteotomised fibula and native skin necrosis. Commonest area of breakdown is the medial canthal region. Plate exposure occurs most commonly at the pyriform sinus. There was extrusion of one non-vascularized bone graft. All these complications were noticed post-radiotherapy. Conclusions: The use of free fibula osteocutaneous flap gives very good results when only alveolar reconstruction is required. The reconstruction of orbital floor with extensive skin loss with post operative radiotherapy has maximum complication rate in long term follow up. A soft tissue flap with non vascularized bone graft may be the best option in such cases.

Keywords: maxilla reconstruction, fibula maxilla, post cancer maxillary reconstruction

Procedia PDF Downloads 134
1582 Pattern of Admission and Recruitment for PhD Positions in European Universities: Globalization of Education or Evading the Hidden Agenda of Racism through Systematic Rejection

Authors: Bashar Dahiru Bashar

Abstract:

Growing research reveals an unprecedented increase in African applicants for PhD positions across European universities. Meanwhile, a very small percentage is accepted as qualified candidates to marginalize, perpetuate stereotypes, and institute racial discrimination. Candidates of color very often encounter barriers and prejudices that not only diminish their sense of belonging but also hinder their academic progress. Although this issue has existed for quite some time, it attracts little attention, even from the academic community in higher education. Moreover, the focus is mostly on the applicants. In this contribution, concern has been raised that the African applicants for PhD positions in European Universities are the victims rather than the perpetrators. The Universities designed a recruitment process that is in all respects exclusive, biased, and European. The recruitment exercise is a hocus-post in order to cover language and racial and ethnic rejection. Just in the same way legacy admission is practiced in the US. The paper further expressed that the logic is to systematically maintain racial hierarchy and social dominance within the education sector. And because those at an advantage are also the ones that have the media and are predominant in academia, issues like this are not receiving deserved attention. Many people were victims of this recruitment process, while others survived severely wounded as a result of mental, social, and economic trauma. It is not the aim of this paper to provide an armchair solution to this issue but only to showcase the process with the hope of providing something that is needed to improve the present day's literacy and situation. The findings contribute to the broader discourse on diversity, equity, and inclusiveness within European Universities, emphasizing, amongst others, the need for cultivating an atmosphere where individuals are valued for their contributions rather than assessed based on race and ethnicity is essential for creating a vibrant and equitable global academic community, forging a path towards a just and harmonious educational landscape where everyone irrespective of race or ethnicity can thrive and contribute to the collective pursuit of knowledge.

Keywords: admission and recruitment for PhD position, globalization of education, systemic rejection, European university

Procedia PDF Downloads 50
1581 The Effects of Organizational Apologies for Some Members’ Annoying Behavior on Other Members’ Appraisal of Their Organization

Authors: Chikae Isobe, Toshihiko Souma, Yoshiya Furukawa

Abstract:

In Japan, an organization is sometimes asked for responsibility and apology toward the organization for the annoying behavior of employees, even though the behavior is not relevant to the organization. Our studies have repeatedly shown that it is important for organizational evaluation to organization propose compensatory behavior for such annoying behavior, even though the behavior is not relevant to the organization. In this study, it was examined how such an organizational response (apology) was likely to evaluate by members of the organization who were not related to the annoying behavior. Three independent variables were manipulated that is organization emotion (guilt and shame), compensation (proposal or not), and the relation between organization and the annoying behavior (relate or not). And the effects of organizational identity (high and low) were also examined. We conducted an online survey for 240 participants through a crowdsourcing company. Participants were asked to imagine a situation in which an incident in which some people in your company did not return an important document that they borrowed privately (vs. at work) became the topic of discussion, and the company responded. For the analysis,189 data (111 males and 78 females, mean age = 40.6) were selected. The results of ANOVA of 2 by2 on organizational appraisal, perceived organizational responsibility, and so on were conducted. Organization appraisal by members was also higher when the organization proposed compensatory behavior. In addition, when the annoying behavior was related to their work (than no related), for those who were high in organization identity (than low), organization appraisal was high. The interaction between relatedness and organizational identity was significant. Differences in relatedness between the organization and annoying behavior were significant in those with low organizational identity but not in those with high organizational identity. When the organization stated not taking compensatory action, members were more likely to perceive the organization as responsible for the annoying behavior. However, the interaction results indicated this tendency was limited to when the annoying behavior was not related to the organization. Furthermore, it tended to be perceived as responsible for the organization when the organization made a statement that felt shame for the annoying behavior not related to the organization and would compensate for the annoying behavior. These results indicate that even members of the organization do not consider the organization's compensatory actions to be unjustified. In addition, because those with high organizational identity perceived the organization to be responsible when it showed strong remorse (shame and compensation), they would be a tendency to make judgments that are consistent with organizational judgments. It would be considered that the Japanese have the norm that even if the organization is not at fault for a member's disruptive behavior, it should respond to it.

Keywords: appraisal for organization, annoying behavior, group shame and guilt, compensation, organizational apologies

Procedia PDF Downloads 124
1580 The Constitutional Rights of a Child to a Clean and Healthy Environment: A Case Study in the Vaal Triangle Region

Authors: Christiena Van Der Bank, Marjone Van Der Bank, Ronelle Prinsloo

Abstract:

The constitutional right to a healthy environment and the constitutional duty imposed on the state actively to protect the environment fulfill the specific duties to prevent pollution and ecological degradation and to promote conservation. The aim of this paper is to draw attention to the relationship between child rights and the environment. The focus is to analyse government’s responses as mandated with section 24 of the Bill of Rights for ensuring the right to a clean and healthy environment. The principle of sustainability of the environment encompasses the notion of equity and the harm to the environment affects the present as well as future generations. Section 24 obliges the state to ensure that the legacy of future generations is protected, an obligation that has been said to be part of the common law. The environment is an elusive and wide concept that can mean different things to different people depending on the context in which it is used for example clean drinking water or safe food. An extensive interpretation of the term environment would include almost everything that may positively or negatively influence the quality of human life. The analysis will include assessing policy measures, legislation, budgetary measures and other measures taken by the government in order to progressively meet its constitutional obligation. The opportunity of the child to grow up in a healthy and safe environment is extremely unjustly distributed. Without a realignment of political, legal and economic conditions this situation will not fundamentally change. South Africa as a developing country that needs to meet the demand of social transformation and economic growth whilst at the same time expediting its ability to compete in global markets, the country will inevitably embark on developmental programmes as a measure for sustainable development. The courts would have to inquire into the reasonableness of those measures. Environmental threats to children’s rights must be identified, taking into account children’s specific needs and vulnerabilities, their dependence and marginalisation. Obligations of states and violations of rights must be made more visible to the general public.

Keywords: environment, children rights, pollution, healthy, violation

Procedia PDF Downloads 173
1579 Investigation of the Physicochemistry in Leaching of Blackmass for the Recovery of Metals from Spent Lithium-Ion Battery

Authors: Alexandre Chagnes

Abstract:

Lithium-ion battery is the technology of choice in the development of electric vehicles. This technology is now mature, although there are still many challenges to increase their energy density while ensuring an irreproachable safety of use. For this goal, it is necessary to develop new cathodic materials that can be cycled at higher voltages and electrolytes compatible with these materials. But the challenge does not only concern the production of efficient batteries for the electrochemical storage of energy since lithium-ion battery technology relies on the use of critical and/or strategic value resources. It is, therefore, crucial to include Lithium-ion batteries development in a circular economy approach very early. In particular, optimized recycling and reuse of battery components must both minimize their impact on the environment and limit geopolitical issues related to tensions on the mineral resources necessary for lithium-ion battery production. Although recycling will never replace mining, it reduces resource dependence by ensuring the presence of exploitable resources in the territory, which is particularly important for countries like France, where exploited or exploitable resources are limited. This conference addresses the development of a new hydrometallurgical process combining leaching of cathodic material from spent lithium-ion battery in acidic chloride media and solvent extraction process. Most of recycling processes reported in the literature rely on the sulphate route, and a few studies investigate the potentialities of the chloride route despite many advantages and the possibility to develop new chemistry, which could get easier the metal separation. The leaching mechanisms and the solvent extraction equilibria will be presented in this conference. Based on the comprehension of the physicochemistry of leaching and solvent extraction, the present study will introduce a new hydrometallurgical process for the production of cobalt, nickel, manganese and lithium from spent cathodic materials.

Keywords: lithium-ion battery, recycling, hydrometallurgy, leaching, solvent extraction

Procedia PDF Downloads 81
1578 Design Components and Reliability Aspects of Municipal Waste Water and SEIG Based Micro Hydro Power Plant

Authors: R. K. Saket

Abstract:

This paper presents design aspects and probabilistic approach for generation reliability evaluation of an alternative resource: municipal waste water based micro hydro power generation system. Annual and daily flow duration curves have been obtained for design, installation, development, scientific analysis and reliability evaluation of the MHPP. The hydro potential of the waste water flowing through sewage system of the BHU campus has been determined to produce annual flow duration and daily flow duration curves by ordering the recorded water flows from maximum to minimum values. Design pressure, the roughness of the pipe’s interior surface, method of joining, weight, ease of installation, accessibility to the sewage system, design life, maintenance, weather conditions, availability of material, related cost and likelihood of structural damage have been considered for design of a particular penstock for reliable operation of the MHPP. A MHPGS based on MWW and SEIG is designed, developed, and practically implemented to provide reliable electric energy to suitable load in the campus of the Banaras Hindu University, Varanasi, (UP), India. Generation reliability evaluation of the developed MHPP using Gaussian distribution approach, safety factor concept, peak load consideration and Simpson 1/3rd rule has presented in this paper.

Keywords: self excited induction generator, annual and daily flow duration curve, sewage system, municipal waste water, reliability evaluation, Gaussian distribution, Simpson 1/3rd rule

Procedia PDF Downloads 558
1577 Euthanasia with Reference to Defective Newborns: An Analysis

Authors: Nibedita Priyadarsini

Abstract:

It is said that Ethics has a wide range of application which mainly deals with human life and human behavior. All ethical decisions are ultimately concerned with life and death. Both life and death must be considered dignified. Medical ethics with its different topics mostly deals with life and death concepts among which euthanasia is one. Various types of debates continue over Euthanasia long since. The question of putting an end to someone’s life has aroused controversial in legal sphere as well as in moral sphere. To permit or not to permit has remained an enigma the world over. Modern medicine is in the stage of transcending limits that cannot be set aside. The morality of allowing people to die without treatment has become more important as methods of treatment have become more sophisticated. Allowing someone to die states an essential recognition that there is some point in any terminal illness when further curative treatment has no purpose and the patient in such situation should allow dying a natural death in comfort, peace, and dignity, without any interference from medical science and technology. But taking a human life is in general sense is illogical in itself. It can be said that when we kill someone, we cause the death; whereas if we merely let someone die, then we will not be responsible for anyone’s death. This point is often made in connection with the euthanasia cases and which is often debatable. Euthanasia in the pediatric age group involves some important issues that are different from those of adult issues. The main distinction that occurs is that the infants and newborns and young children are not able to decide about their future as the adult does. In certain cases, where the child born with some serious deformities with no hope of recovery, in that cases doctor decide not to perform surgery in order to remove the blockage, and let the baby die. Our aim in this paper is to examine, whether it is ethically justified to withhold or to apply euthanasia on the part of the defective infant. What to do with severely defective infants from earliest time if got to know that they are not going to survive at all? Here, it will deal mostly with the ethics in deciding the relevant ethical concerns in the practice of euthanasia with the defective newborns issues. Some cases in relation to disabled infants and newborn baby will be taken in order to show what to do in a critical condition, that the patient and family members undergoes and under which condition those could be eradicated, if not all but some. The final choice must be with the benefit of the patient.

Keywords: ethics, medical ethics, euthanasia, defective newborns

Procedia PDF Downloads 204
1576 Radon-222 Concentration and Potential Risk to Workers of Al-Jalamid Phosphate Mines, North Province, Saudi Arabia

Authors: El-Said. I. Shabana, Mohammad S. Tayeb, Maher M. T. Qutub, Abdulraheem A. Kinsara

Abstract:

Usually, phosphate deposits contain 238U and 232Th in addition to their decay products. Due to their different pathways in the environment, the 238U/232Th activity concentration ratio usually found to be greater than unity in phosphate sediments. The presence of these radionuclides creates a potential need to control exposure of workers in the mining and processing activities of the phosphate minerals in accordance with IAEA safety standards. The greatest dose to workers comes from exposure to radon, especially 222Rn from the uranium series, and has to be controlled. In this regard, radon (222Rn) was measured in the atmosphere (indoor and outdoor) of Al-Jalamid phosphate-mines working area using a portable radon-measurement instrument RAD7, in a purpose of radiation protection. Radon was measured in 61 sites inside the open phosphate mines, the phosphate upgrading facility (offices and rooms of the workers, and in some open-air sites) and in the dwellings of the workers residence-village that lies at about 3 km from the mines working area. The obtained results indicated that the average indoor radon concentration was about 48.4 Bq/m3. Inside the upgrading facility, the average outdoor concentrations were 10.8 and 9.7 Bq/m3 in the concentrate piles and crushing areas, respectively. It was 12.3 Bq/m3 in the atmosphere of the open mines. These values are comparable with the global average values. Based on the average values, the annual effective dose due to radon inhalation was calculated and risk estimates have been done. The average annual effective dose to workers due to the radon inhalation was estimated by 1.32 mSv. The potential excess risk of lung cancer mortality that could be attributed to radon, when considering the lifetime exposure, was estimated by 53.0x10-4. The results have been discussed in detail.

Keywords: dosimetry, environmental monitoring, phosphate deposits, radiation protection, radon

Procedia PDF Downloads 275
1575 Examining How Youth Use Mobile Devices for Health Information: Preliminary Findings of a Survey Study with High School Students in Croatia

Authors: Sung Un Kim, Ivana Martinović, Snježana Stanarević Katavić

Abstract:

As more and more youth use mobile devices, such as tablets and smartphones, for information seeking in their everyday lives, the purpose of this study is to understand the behaviors of youth seeking health information on mobile devices. The specific objective of this study is to examine 1) for what health issues youth use mobile devices, 2) for what reasons youth use mobile devices to obtain health information, 3) in what ways youth use mobile devices for health information, and 4) the features of health applications that youth find useful. The researchers devised a questionnaire for this study. Four hundred eight students from two high schools, located in Osijek, Croatia, participated by answering the questionnaire (281 girls and 127 boys). The collected data were analyzed using descriptive statistics and content analysis. The results show that among all participants, about 85 percent (n = 344) reported having used mobile devices for health information. The most frequent health topic for which they had been using mobile devices is physical activity (n = 273), followed by eating issues and nutrition (n = 224), mental health (n = 160), sexual health (n = 157), alcohol, drugs, and tobacco (n = 125), safety (n = 96) and particular diseases (n = 62). They use mobile devices to obtain health information due to the ease of use (n = 342), the ease of sharing health information (n = 281), portability (n = 215), timeliness (n = 162), and the ease of tracking/recording/monitoring health status (n = 147). Of those who have used mobile devices for health information, three-quarters (n = 261) use mobile devices to search health information, while 32.8% (n =113) use applications and 31.7% (n =109) browse information. Those who have used applications for health information (n = 113) consider the alert feature (n=107) as the most useful, followed by the tracking/recording/monitoring feature (n =92), the customized information feature (n = 86), the video feature (n = 58), and the sharing feature (n =39). It is notable that although health applications have been actively developed and studied, a majority of the participants search for or browse information on mobile devices, instead of using applications. The researchers will discuss reasons that some of them did not use mobile devices to obtain health information, students’ concerns about using health applications, and features that they wish to have in health applications.

Keywords: Croatia, health information, information seeking behaviors, mobile devices, youth

Procedia PDF Downloads 405
1574 Violence against Police Officers in Germany

Authors: Anne T. Herr, Clemens Lorei

Abstract:

Employees of organizations with security tasks, such as emergency services, public order services, or police forces, work every day to ensure people's safety. Violence against police is, therefore, a relevant topic both socially and politically. An increase in violence is often discussed without there being any verifiable and generally valid data. So far, scientific research has mainly focused on offender characteristics and crime statistics. These surveys are mostly subjective, retrospective, and neglect the dynamics and interactions in concrete violent situations. Therefore, more recent research methods attempt to capture the issue of violence against emergency forces more comprehensively. However, the operationalization of the constructs and the methodological approach pose particular challenges. This contribution provides an overview of new perspectives on the understanding of violent assaults and identifies current research gaps. In addition, a new research project of the Hessian University of Police and Administration in Germany is presented. In the 'AMBOSafe' study, different theoretical backgrounds for understanding violence against police and emergency services personnel will be combined in order to capture as many different perspectives of violent assaults as possible in a multimodal research approach. In a retrospective as well as in a longitudinal survey, the conditions of escalation dynamics in the assaults are recorded and supplemented by the current and valid prevalence of physical and verbal assaults in a period of four months. In addition, qualitative interviews with those affected will be used to record more detailed descriptions of and the feelings during the assaults, as well as possible causes and connections between the different groups of people. In addition to the reports of the police forces, the motives of the attackers will be collected and supplemented by analyzing the criminal case files. This knowledge can contribute to a more comprehensive understanding of violent assaults against police forces in order to be able to derive scientifically based preventive measures.

Keywords: assaults, crime statistics, escalation dynamics, police

Procedia PDF Downloads 115
1573 Analysis of the Behavior of the Structure Under Internal Anfo Explosion

Authors: Seung-Min Ko, Seung-Jai Choi, Gun Jung, Jang-Ho Jay Kim

Abstract:

Although extensive explosion-related research has been performed in the past several decades, almost no research has focused on internal blasts. However, internal blast research is needed to understand about the behavior of a containment structure or building under internal blast loading, as in the case of the Chornobyl and Fukushima nuclear accidents. Therefore, the internal blast study concentrated on RC and PSC structures is performed. The test data obtained from reinforced concrete (RC) and prestressed concrete (PSC) tubular structures applied with an internal explosion using ammonium nitrate/fuel oil (ANFO) charge are used to assess their deformation resistance and ultimate failure load based on the structural stiffness change under various charge weight. For the internal blast charge weight, ANFO explosive charge weights of 15.88, 20.41, 22.68 and 24.95 kg were selected for the RC tubular structures, and 22.68, 24.95, 27.22, 29.48, and 31.75 kg were selected for PSC tubular structures, which were detonated at the center of cross section at the mid-span with a standoff distance of 1,000mm to the inner wall surface. Then, the test data were used to predict the internal charge weight required to fail a real scale reinforced concrete containment vessels (RCCV) and prestressed concrete containment vessel (PCCV). Then, the analytical results based on the experimental data were derived using the simple assumptions of the models, and another approach using the stiffness, deformation and explosion weight relationship was used to formulate a general method for analyzing internal blasted tubular structures. A model of the internal explosion of a steel tube was used as an example for validation. The proposed method can be used generically, using factors according to the material characteristics of the target structures. The results of the study are discussed in detail in the paper.

Keywords: internal blast, reinforced concrete, RCCV, PCCV, stiffness, blast safety

Procedia PDF Downloads 80
1572 Digital Environment as a Factor of the City's Competitiveness in Attracting Tourists: The Case of Yekaterinburg

Authors: Alexander S. Burnasov, Anatoly V. Stepanov, Maria Y. Ilyushkina

Abstract:

In the conditions of transition to the digital economy, the digital environment of the city becomes one of the key factors of its tourism attractiveness. Modern digital environment makes travelling more accessible, improves the quality of travel services and the attractiveness of many tourist destinations. The digitalization of the industry allows to use resources more efficiently, to simplify business processes, to minimize risks, and to improve travel safety. The city promotion as a tourist destination in the foreign market becomes decisive in the digital environment. Information technologies are extremely important for the functioning of not only any tourist enterprise but also the city as a whole. In addition to solving traditional problems, it is also possible to implement some innovations from the tourism industry, such as the availability of city services in international systems of booking tickets and booking rooms in hotels, the possibility of early booking of theater and museum tickets, the possibility of non-cash payment by cards of international payment systems, Internet access in the urban environment for travelers. The availability of the city's digital services makes it possible to reduce ordering costs, contributes to the optimal selection of tourist products that meet the requirements of the tourist, provides increased transparency of transactions. The users can compare prices, features, services, and reviews of the travel service. The ability to share impressions with friends thousands of miles away directly affects the image of the city. It is possible to promote the image of the city in the digital environment not only through world-scale events (such as World Cup 2018, international summits, etc.) but also through the creation and management of services in the digital environment aimed at supporting tourism services, which will help to improve the positioning of the city in the global tourism market.

Keywords: competitiveness, digital environment, travelling, Yekaterinburg

Procedia PDF Downloads 138
1571 Fault-Tolerant Control Study and Classification: Case Study of a Hydraulic-Press Model Simulated in Real-Time

Authors: Jorge Rodriguez-Guerra, Carlos Calleja, Aron Pujana, Iker Elorza, Ana Maria Macarulla

Abstract:

Society demands more reliable manufacturing processes capable of producing high quality products in shorter production cycles. New control algorithms have been studied to satisfy this paradigm, in which Fault-Tolerant Control (FTC) plays a significant role. It is suitable to detect, isolate and adapt a system when a harmful or faulty situation appears. In this paper, a general overview about FTC characteristics are exposed; highlighting the properties a system must ensure to be considered faultless. In addition, a research to identify which are the main FTC techniques and a classification based on their characteristics is presented in two main groups: Active Fault-Tolerant Controllers (AFTCs) and Passive Fault-Tolerant Controllers (PFTCs). AFTC encompasses the techniques capable of re-configuring the process control algorithm after the fault has been detected, while PFTC comprehends the algorithms robust enough to bypass the fault without further modifications. The mentioned re-configuration requires two stages, one focused on detection, isolation and identification of the fault source and the other one in charge of re-designing the control algorithm by two approaches: fault accommodation and control re-design. From the algorithms studied, one has been selected and applied to a case study based on an industrial hydraulic-press. The developed model has been embedded under a real-time validation platform, which allows testing the FTC algorithms and analyse how the system will respond when a fault arises in similar conditions as a machine will have on factory. One AFTC approach has been picked up as the methodology the system will follow in the fault recovery process. In a first instance, the fault will be detected, isolated and identified by means of a neural network. In a second instance, the control algorithm will be re-configured to overcome the fault and continue working without human interaction.

Keywords: fault-tolerant control, electro-hydraulic actuator, fault detection and isolation, control re-design, real-time

Procedia PDF Downloads 179
1570 Stress among Mothers of Children with Cerebral Palsy

Authors: Priyanka Tiwari, Uma Devi Ranjit, Ritesh Thapa

Abstract:

Background and Significance: Cerebral Palsy (CP) influences not only the child's everyday functioning but also the functioning of whole family. Application of study findings can be used in clinical or community setting to screen the parents of children with cerebral palsy in order to identify the compromised domain of stress which in turn will help to improve the interaction between parent and child with disability and thus ultimately affect the progress that a child makes in his or her therapeutic or educational programs. Objective: The objective of the study was to assess the level of stress in mothers of children with CP by adopting mixed method design. Methodology: Cross-sectional descriptive design was adopted in the quantitative design where Parental Stress Scale (PSS) was utilized to collect data from a convenient sample of 40 mothers of children with CP who were under regular follow-up by home visitor of Self-help Group for Cerebral Palsy while embedded qualitative design was used to explore the stress of mothers of CP affected children. From the parent population of quantitative sample 4 mothers were chosen for in-depth exploration, regarding their stress by means of case study method. Descriptive statistics like frequency, percentage, mean, median, standard deviation, correlation and inferential statistics like Mann-Whitney U test and Kruskal-Wallis H test were used to describe and assess relationship between variables. Findings: The mean stress experienced by mothers of children with cerebral palsy was 53.62±9.53 with 15% percent of the mothers experiencing severe stress. There was significant association between age group of mother and total stress score and negative themes of stress. Similarly, signification association was found between educational status of the mother and positive themes of stress which was convergent with the qualitative finding as well, where literate mothers had more positive view of their child's disability which could be attributed to their educational level as education provides us with a broad perspective to look at a situation. Conclusions: Still one-sixth of the mothers experienced severe stress so if we want to ensure the well-being of the children affected by cerebral palsy, then parents caring for them need to be looked after as well.

Keywords: stress, cerebral palsy, mothers, mixed method

Procedia PDF Downloads 259
1569 Effect of Thermal Aging on Low Cycle Fatigue of Alloy 690

Authors: Kushal Gowda Jayaram, Joseph Huret, Jonathan Quibel, Walter-John Chitty, Gilbert Henaff

Abstract:

Thermal aging is one of the concerns for the long-term operation of nuclear power plants. Indeed, components in the primary circuit undergo thermal aging while exposed to the chemically active environment of Pressurized Water Reactors (PWRs) over time. Among the materials used in the reactor components, Alloy 690 can be found in some critical components for nuclear safety. Despite its importance, research on the effect of thermal aging on the microstructural changes and low cycle fatigue (LCF) behavior of Alloy 690 remains limited. This study aims to assess the impact of thermal aging on the fatigue life of Alloy 690. The as-received sample underwent aging at 420°C for 4000 hours, representing the equivalent aging of 60 years in reactor working conditions. First, the characterization of the area and density of intergranular and intragranular precipitates was performed to understand the microstructural changes in the aged specimen. Then, low cycle fatigue tests were conducted on the as received and aged samples at varying strain amplitudes. To investigate the influence of thermal aging on the fatigue behavior of Alloy 690, fracture surfaces were analyzed to estimate fatigue crack growth rates based on striation spacing measurements. Additionally, the axially cut fractured samples have undergone analysis using Electron Backscatter Diffraction (EBSD) to understand the effect of aging on strain localization near the crack path. Results indicate that while the characterization of the area and density of intergranular precipitates in the aged specimen (for 2000 hours, approximately 30 years) showed no significant changes, there was a slight increase in the area and density of intragranular precipitates under the same conditions.

Keywords: alloy 690, thermal aging, low cycle fatigue, precipitates

Procedia PDF Downloads 40
1568 Using Baculovirus Expression Vector System to Express Envelop Proteins of Chikungunya Virus in Insect Cells and Mammalian Cells

Authors: Tania Tzong, Chao-Yi Teng, Tzong-Yuan Wu

Abstract:

Currently, Chikungunya virus (CHIKV) transmitted to humans by Aedes mosquitoes has distributed from Africa to Southeast Asia, South America, and South Europe. However, little is known about the antigenic targets for immunity, and there are no licensed vaccines or specific antiviral treatments for the disease caused by CHIKV. Baculovirus has been recognized as a novel vaccine vector with attractive characteristic features of an optional vaccine delivery vehicle. This approach provides the safety and efficacy of CHIKV vaccine. In this study, bi-cistronic recombinant baculoviruses vAc-CMV-CHIKV26S-Rhir-EGFP and vAc-CMV-pH-CHIKV26S-Lir-EGFP were produced. Both recombinant baculovirus can express EGFP reporter gene in insect cells to facilitate the recombinant virus isolation and purification. Examination of vAc-CMV-CHIKV26S-Rhir-EGFP and vAc-CMV-pH-CHIKV26S-Lir-EGFP showed that this recombinant baculovirus could induce syncytium formation in insect cells. Unexpectedly, the immunofluorescence assay revealed the expression of E1 and E2 of CHIKV structural proteins in insect cells infected by vAc-CMV-CHIKV26S-Rhir-EGFP. This result may imply that the CMV promoter can induce the transcription of CHIKV26S in insect cells. There are also E1 and E2 expression in mammalian cells transduced by vAc-CMV-CHIKV26S-Rhir-EGFP and vAc-CMV-pH-CHIKV26S-Lir-EGFP. The expression of E1 and E2 proteins of insect and mammalian cells was validated again by Western blot analysis. The vector construction with dual tandem promoters, which is polyhedrin and CMV promoter, has higher expression of the E1 and E2 of CHIKV structural proteins than the vector construction with CMV promoter only. Most of the E1 and E2 proteins expressed in mammalian cells were glycosylated. In the future, the expression of structural proteins of CHIKV in mammalian cells is expected can form virus-like particle, so it could be used as a vaccine for chikungunya virus.

Keywords: chikungunya virus, virus-like particle, vaccines, baculovirus expression vector system

Procedia PDF Downloads 424