Search results for: back to back PWM converter

Authors: Yanyan Wang

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This paper on second language teaching and learning uses conversation analysis (CA) approach and focuses on how second language learners of Chinese do repair when making clarification requests. In order to demonstrate their behavior in interaction, a comparison was made to study the differences between native speakers of Chinese with non-native speakers of Chinese. The significance of the research is to make second language teachers and learners aware of repair and how to seek clarification. Utilizing the methodology of CA, the research involved two sets of naturally occurring recordings, one of native speaker students and the other of non-native speaker students. Both sets of recording were telephone talks between students and teachers. There were 50 native speaker students and 50 non-native speaker students. From multiple listening to the recordings, the parts with repairs for clarification were selected for analysis which included the moments in the talk when students had problems in understanding or hearing the speaker and had to seek clarification. For example, ‘Sorry, I do not understand ‘and ‘Can you repeat the question? ‘were the parts as repair to make clarification requests. In the data, there were 43 such cases from native speaker students and 88 cases from non-native speaker students. The non-native speaker students were more likely to use repair to seek clarification. Analysis on how the students make clarification requests during their conversation was carried out by investigating how the students initiated problems and how the teachers repaired the problems. In CA term, it is called other-initiated self-repair (OISR), which refers to student-initiated teacher-repair in this research. The findings show that, in initiating repair, native speaker students pay more attention to mutual understanding (inter-subjectivity) while non-native speaker students, due to their lack of language proficiency, pay more attention to their status of knowledge (epistemic) switch. There are three major differences: 1, native Chinese students more often initiate closed-class OISR (seeking specific information in the request) such as repeating a word or phrases from the previous turn while non-native students more frequently initiate open-class OISR (not specifying clarification) such as ‘sorry, I don’t understand ‘. 2, native speakers’ clarification requests are treated by the teacher as understanding of the content while non-native learners’ clarification requests are treated by teacher as language proficiency problem. 3, native speakers don’t see repair as knowledge issue and there is no third position in the repair sequences to close repair while non-native learners take repair sequence as a time to adjust their knowledge. There is clear closing third position token such as ‘oh ‘ to close repair sequence so that the topic can go back. In conclusion, this paper uses conversation analysis approach to compare differences between native Chinese speakers and non-native Chinese learners in their ways of conducting repair when making clarification requests. The findings are useful in future Chinese language teaching and learning, especially in teaching pragmatics such as requests.

Keywords: conversation analysis (CA), clarification request, second language (L2), teaching implication

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Authors: Surekha Barkur, Aseefhali Bankapur, Santhosh Chidangil

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Raman Tweezers technique has become prevalent in single cell studies. This technique combines Raman spectroscopy which gives information about molecular vibrations, with optical tweezers which use a tightly focused laser beam for trapping the single cells. Thus Raman Tweezers enabled researchers analyze single cells and explore different applications. The applications of Raman Tweezers include studying blood cells, monitoring blood-related disorders, silver nanoparticle-induced stress, etc. There is increased interest in the toxic effect of nanoparticles with an increase in the various applications of nanoparticles. The interaction of these nanoparticles with the cells may vary with their size. We have studied the effect of silver nanoparticles of sizes 10nm, 40nm, and 100nm on erythrocytes using Raman Tweezers technique. Our aim was to investigate the size dependence of the nanoparticle effect on RBCs. We used 785nm laser (Starbright Diode Laser, Torsana Laser Tech, Denmark) for both trapping and Raman spectroscopic studies. 100 x oil immersion objectives with high numerical aperture (NA 1.3) is used to focus the laser beam into a sample cell. The back-scattered light is collected using the same microscope objective and focused into the spectrometer (Horiba Jobin Vyon iHR320 with 1200grooves/mm grating blazed at 750nm). Liquid nitrogen cooled CCD (Symphony CCD-1024x256-OPEN-1LS) was used for signal detection. Blood was drawn from healthy volunteers in vacutainer tubes and centrifuged to separate the blood components. 1.5 ml of silver nanoparticles was washed twice with distilled water leaving 0.1 ml silver nanoparticles in the bottom of the vial. The concentration of silver nanoparticles is 0.02mg/ml so the 0.03mg of nanoparticles will be present in the 0.1 ml nanoparticles obtained. The 25 ul of RBCs were diluted in 2 ml of PBS solution and then treated with 50 ul (0.015mg) of nanoparticles and incubated in CO2 incubator. Raman spectroscopic measurements were done after 24 hours and 48 hours of incubation. All the spectra were recorded with 10mW laser power (785nm diode laser), 60s of accumulation time and 2 accumulations. Major changes were observed in the peaks 565 cm-1, 1211 cm-1, 1224 cm-1, 1371 cm-1, 1638 cm-1. A decrease in intensity of 565 cm-1, increase in 1211 cm-1 with a reduction in 1224 cm-1, increase in intensity of 1371 cm-1 also peak disappearing at 1635 cm-1 indicates deoxygenation of hemoglobin. Nanoparticles with higher size were showing maximum spectral changes. Lesser changes observed in case of 10nm nanoparticle-treated erythrocyte spectra.

Keywords: erythrocytes, nanoparticle-induced toxicity, Raman tweezers, silver nanoparticles

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Authors: Chiahsu Yang, Peiling Wu, Ted Ho

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From emphasizing economic development to stressing public happiness, the international community mainly hopes to be able to understand whether the quality of life for the public is becoming better. The Better Life Index (BLI) constructed by OECD uses living conditions and quality of life as starting points to cover 11 areas of life and to convey the state of the general public’s well-being. In light of the BLI framework, the Directorate General of Budget, Accounting and Statistics (DGBAS) of the Executive Yuan instituted the Gross National Happiness Index to understand the needs of the general public and to measure the progress of the aforementioned conditions in residents across the island. Whereas living conditions consist of income and wealth, jobs and earnings, and housing conditions, health status, work and life balance, education and skills, social connections, civic engagement and governance, environmental quality, personal security. The ICT area consists of health care, living environment, ICT-enabled communication, transportation, government, education, pleasure, purchasing, job & employment. In the wake of further science and technology development, rapid formation of information societies, and closer integration between lifestyles and information societies, the public’s well-being within information societies has indeed become a noteworthy topic. the Board of Science and Technology of the Executive Yuan use the OECD’s BLI as a reference in the establishment of the Taiwan-specific ICT-Enabled Better Life Index. Using this index, the government plans to examine whether the public’s quality of life is improving as well as measure the public’s satisfaction with current digital quality of life. This understanding will enable the government to gauge the degree of influence and impact that each dimension of digital services has on digital life happiness while also serving as an important reference for promoting digital service development. The content of the ICT Enabled Better Life Index. Information and communications technology (ICT) has been affecting people’s living styles, and further impact people’s quality of life (QoL). Even studies have shown that ICT access and usage have both positive and negative impact on life satisfaction and well-beings, many governments continue to invest in e-government programs to initiate their path to information society. This research is the few attempts to link the e-government benchmark to the subjective well-being perception, and further address the gap between user’s perception and existing hard data assessment, then propose a model to trace measurement results back to the original public policy in order for policy makers to justify their future proposals.

Keywords: information and communications technology, quality of life, satisfaction, well-being

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Authors: Niina Meriläinen

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Digital platforms are arenas for dialogue, various kinds of political debates, information and news gathering, policymaking, and social change processes. Human rights serve as examples of social and political issues that are universally noted as principles and yet often violated on digital platforms as well as in the analog world. Digital platforms in this study are different Internet sites, blogs, discussion platforms, social media apps, and gaming. Various actors, from human rights activists and non-governmental organizations to individual people, governments, and corporations, use digital platforms along with analog arenas to discuss and defend human rights, while violators can find new victims and continue violating rights on the same platforms. Digital platforms create opportunities for various women and minorities to empower themselves and others and to be active in various arenas of society and policymaking. At the same time, digital platforms pose threats to human rights globally, especially to women, girls, and minorities. The results of this meta-study of n=120 academic case studies indicate that more research is needed to determine the framework of human rights and human rights on digital platforms. A broad discussion must be had on what human rights require in the digital realm and how ICTs may enhance or threaten our ability to respect, protect, and fulfill a wide variety of human rights while various digital platforms pose multiple threats to human rights. This relates to the willingness of political decision-makers to act upon various crimes committed on and with online platforms. More research is needed to determine the framework of digital human rights and human rights on digital platforms in relation to political communication and decision-making. It is important to develop a framework in which these are defined. It must be discussed who participates in this process: those whose rights are violated, companies that profit by selling our personal data, activists, governments, and some unknown actors. In the end, the question comes back to who has the power to define what we talk about, when, and where. This use of power plays a big role. Digital platforms illustrate the darker side of technological progress, which, on the one hand, has given various people the possibility to engage in society, empower themselves, and take ownership of their rights globally. At the same time, the platforms enable others to use the same platforms to find victims, abuse them, and exploit them. Bullying, harassment, and violence are rampant on various digital platforms, where minorities and people with limited support are victims. There is indeed a need for a discussion of normative values in the era of fake news, the power of influencers, Trumpism, and institutionalized disregard for human rights, gender equality, and the elimination of gender-based violence online. Attention and obligations must be placed on politicians and internet architecture, such as corporations, and their roles in human rights and their violations online.

Keywords: human rights, digital platforms, violations, internet, social media

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Authors: Nicolas Peyret, Sylvain Courtois, Gaël Chevallier

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This article outlines the development of the Project Based Learning (PBL) at the level of a last year’s Bachelor’s Degree. This form of pedagogy has for objective to allow a better involving of the students from the beginning of the module. The theoretical contributions are introduced during the project to solving a technological problem. The module in question is the module of mechanical dimensioning method of Supméca a French engineering school. This school issues a Master’s Degree. While the teaching methods used in primary and secondary education are frequently renewed in France at the instigation of teachers and inspectors, higher education remains relatively traditional in its practices. Recently, some colleagues have felt the need to put the application back at the heart of their theoretical teaching. This need is induced by the difficulty of covering all the knowledge deductively before its application. It is therefore tempting to make the students 'learn by doing', even if it doesn’t cover some parts of the theoretical knowledge. The other argument that supports this type of learning is the lack of motivation the students have for the magisterial courses. The role-play allowed scenarios favoring interaction between students and teachers… However, this pedagogical form known as 'pedagogy by project' is difficult to apply in the first years of university studies because of the low level of autonomy and individual responsibility that the students have. The question of what the student actually learns from the initial program as well as the evaluation of the competences acquired by the students in this type of pedagogy also remains an open problem. Thus we propose to add to the pedagogy by project format a regressive part of interventionism by the teacher based on pedagogy by example. This pedagogical scenario is based on the cognitive load theory and Bruner's constructivist theory. It has been built by relying on the six points of the encouragement process defined by Bruner, with a concrete objective, to allow the students to go beyond the basic skills of dimensioning and allow them to acquire the more global skills of engineering. The implementation of project-based teaching coupled with pedagogy by example makes it possible to compensate for the lack of experience and autonomy of first-year students, while at the same time involving them strongly in the first few minutes of the module. In this project, students have been confronted with the real dimensioning problems and are able to understand the links and influences between parameter variations and dimensioning, an objective that we did not reach in classical teaching. It is this form of pedagogy which allows to accelerate the mastery of basic skills and so spend more time on the engineer skills namely the convergence of each dimensioning in order to obtain a validated mechanism. A self-evaluation of the project skills acquired by the students will also be presented.

Keywords: Bruner's constructivist theory, mechanisms dimensioning, pedagogy by example, problem based learning

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Authors: Ramdan B. A. Koad, Ahmed F. Zobaa

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Since the output characteristics of Photovoltaic (PV) system depends on the ambient temperature, solar radiation and load impedance, its maximum Power Point (MPP) is not constant. Under each condition PV module has a point at which it can produce its MPP. Therefore, a Maximum Power Point Tracking (MPPT) method is needed to uphold the PV panel operating at its MPP. This paper presents comparative study between the conventional MPPT methods used in (PV) system: Perturb and Observe (P&O), Incremental Conductance (IncCond), and Particle Swarm Optimization (PSO) algorithm for (MPPT) of (PV) system. To evaluate the study, the proposed PSO MPPT is implemented on a DC-DC converter and has been compared with P&O and INcond methods in terms of their tracking speed, accuracy and performance by using the Matlab tool Simulink. The simulation result shows that the proposed algorithm is simple, and is superior to the P&O and IncCond methods.

Keywords: photovoltaic systems, maximum power point tracking, perturb and observe method, incremental conductance, methods and practical swarm optimization algorithm

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Authors: Christofas Stergianos, Jason Atkin, Herve Morvan

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As air traffic increases, more airports are interested in utilizing optimization methods. Many processes happen in parallel at an airport, and complex models are needed in order to have a reliable solution that can be implemented for ground movement operations. The ground movement for aircraft in an airport, allocating a path to each aircraft to follow in order to reach their destination (e.g. runway or gate), is one process that could be optimized. The Quickest Path Problem with Time Windows (QPPTW) algorithm has been developed to provide a conflict-free routing of vehicles and has been applied to routing aircraft around an airport. It was subsequently modified to increase the accuracy for airport applications. These modifications take into consideration specific characteristics of the problem, such as: the pushback process, which considers the extra time that is needed for pushing back an aircraft and turning its engines on; stand holding where any waiting should be allocated to the stand; and runway sequencing, where the sequence of the aircraft that take off is optimized and has to be respected. QPPTW involves searching for the quickest path by expanding the search in all directions, similarly to Dijkstra’s algorithm. Finding a way to direct the expansion can potentially assist the search and achieve a better performance. We have further modified the QPPTW algorithm to use a heuristic approach in order to guide the search. This new algorithm is based on the A-star search method but estimates the remaining time (instead of distance) in order to assess how far the target is. It is important to consider the remaining time that it is needed to reach the target, so that delays that are caused by other aircraft can be part of the optimization method. All of the other characteristics are still considered and time windows are still used in order to route multiple aircraft rather than a single aircraft. In this way the quickest path is found for each aircraft while taking into account the movements of the previously routed aircraft. After running experiments using a week of real aircraft data from Zurich Airport, the new algorithm (A-star QPPTW) was found to route aircraft much more quickly, being especially fast in routing the departing aircraft where pushback delays are significant. On average A-star QPPTW could route a full day (755 to 837 aircraft movements) 56% faster than the original algorithm. In total the routing of a full week of aircraft took only 12 seconds with the new algorithm, 15 seconds faster than the original algorithm. For real time application, the algorithm needs to be very fast, and this speed increase will allow us to add additional features and complexity, allowing further integration with other processes in airports and leading to more optimized and environmentally friendly airports.

Keywords: a-star search, airport operations, ground movement optimization, routing and scheduling

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Authors: Xavier Louis, Madhava Soma Sundaram

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The Palk Bay, a narrow strip of water, separates the state of Tamil Nadu in India from north Sri Lanka. The bay, which is 137 km in length and varies from 64 to 137 kilometers in width and is home to more than 580 fish species and chunks of shrimp’s resources, is divided by the International Maritime Boundary Line (IMBL). The bay, bordering it are five Tamil Nadu districts of India and three Sri Lankan districts and assumes importance as it is one of the areas presenting permanent and serious challenges to both India and Sri Lanka with respect to the fishing rights in the Bay. Fishermen from both sides were enjoying fishing with hormones for centuries. Katchchadeevu is a tiny Island located in the Bay, which was a part of India. After the Katchchadeevu agreement 1974 it became a part of Sri Lanka and a fishing conflict arose between the two countries' fishermen. Fuelling the dispute over Katchatheevu is the overfishing of Indian mechanized trawlers in Palk Bay and the damaging environmental and economic effects of trawling. Since 2008, more than 300 Indian fishermen have been killed by firing by Sri Lankan Navy, nearly 100 fishermen have gone missing and more than 3000 fishermen were arrested and later released after the trials for trespassing into Sri Lankan waters. Currently, more than 120 fishing boats and 29 fishermen are in Sri Lankan custody. This paper attempts to find out the causes of fishing conflict and who has the fishing rights in the mentioned waters, how the international treaties are complied with at the time of arrest and trials, how the arrested fishermen are treated by them and how they suffer from fishermen families without a breadwinner. A Semi-structured interview schedule tool was prepared by the researcher, which is suitable for measuring quantitative and qualitative aspects of the above-mentioned theme. One hundred arrested fishermen were interviewed and recorded their prison experiences in Sri Lanka. The research found that the majority of the fishermen believe that they have the right to fish in the historical water and that the Sri Lankan Naval personnel have brutally attacked the Indian fishermen at the time of the arrest. The majority of the fishermen accepted that they had limited fishing grounds. As a result, they entered Sri Lankan waters for their livelihood. The majority of the fishermen expected that they would also get their belongings back at the time of release, primarily the boats. Most of the arrested fishermen's families face financial crises in the absence of their breadwinners and this situation has created conditions for child labor among the affected families and some fishers migrate to different places for different occupations. The majority of the fishers have trauma about their victimization and face uncertainty in the future of their occupation. We can discuss more the causes and nature of the fishing conflict and the financial and psychological victimization of Indian fishermen in relation to the conflict.

Keywords: palk bay, historical water, fishing conflict, arrested fishermen, victimization

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Authors: Pooja S. Billade, Sanjay S. Chopade

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This paper focuses on the design of three phase induction motor control using single phase input and GSM.The controller used in this work is a wireless speed control using a GSM technique that proves to be very efficient and reliable in applications.The most common principle is the constant V/Hz principle which requires that the magnitude and frequency of the voltage applied to the stator of a motor maintain a constant ratio. By doing this, the magnitude of the magnetic field in the stator is kept at an approximately constant level throughout the operating range. Thus, maximum constant torque producing capability is maintained. The energy that a switching power converter delivers to a motor is controlled by Pulse Width Modulated signals applied to the gates of the power transistors in H-bridge configuration. PWM signals are pulse trains with fixed frequency and magnitude and variable pulse width. When a PWM signal is applied to the gate of a power transistor, it causes the turn on and turns off intervals of the transistor to change from one PWM period.

Keywords: index terms— PIC, GSM (global system for mobile), LCD (Liquid Crystal Display), IM (Induction Motor)

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Authors: Ruchirek Ratchaburi, W. Kevin. Hicks, Christopher S. Malley, Lisa D. Emberson

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Air pollution problems in Thailand have improved over the last few decades, but in some areas, concentrations of coarse particulate matter (PM₁₀) are above health and regulatory guidelines. It is, therefore, useful to investigate how PM₁₀ varies across Thailand, what conditions cause this variation, and how could PM₁₀ concentrations be reduced. This research uses data collected by the Thailand Pollution Control Department (PCD) from 17 monitoring sites, located across 12 provinces, and obtained between 2011 and 2015 to assess PM₁₀ concentrations and the conditions that lead to different levels of pollution. This is achieved through exploration of air mass pathways using trajectory analysis, used in conjunction with the monitoring data, to understand the contribution of different months, an hour of the day and source regions to annual PM₁₀ concentrations in Thailand. A focus is placed on locations that exceed the national standard for the protection of human health. The analysis shows how this approach can be used to explore the influence of biomass burning on annual average PM₁₀ concentration and the difference in air pollution conditions between Northern and Southern Thailand. The results demonstrate the substantial contribution that open biomass burning from agriculture and forest fires in Thailand and neighboring countries make annual average PM₁₀ concentrations. The analysis of PM₁₀ measurements at monitoring sites in Northern Thailand show that in general, high concentrations tend to occur in March and that these particularly high monthly concentrations make a substantial contribution to the overall annual average concentration. In 2011, a > 75% reduction in the extent of biomass burning in Northern Thailand and in neighboring countries resulted in a substantial reduction not only in the magnitude and frequency of peak PM₁₀ concentrations but also in annual average PM₁₀ concentrations at sites across Northern Thailand. In Southern Thailand, the annual average PM₁₀ concentrations for individual years between 2011 and 2015 did not exceed the human health standard at any site. The highest peak concentrations in Southern Thailand were much lower than for Northern Thailand for all sites. The peak concentrations at sites in Southern Thailand generally occurred between June and October and were associated with air mass back trajectories that spent a substantial proportion of time over the sea, Indonesia, Malaysia, and Thailand prior to arrival at the monitoring sites. The results show that emissions reductions from biomass burning and forest fires require action on national and international scales, in both Thailand and neighboring countries, such action could contribute to ensuring compliance with Thailand air quality standards.

Keywords: annual average concentration, long-range transport, open biomass burning, particulate matter

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Authors: P.Kiruthika, K. Ramani

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This paper presented the design and advancement of a single-phase 27-level Hybrid Multilevel DC-AC Converter interfacing with Photo Voltaic. In this context, the Multicarrier Pulse Width Modulation method can be implemented in 27-level Hybrid Multilevel Inverter for generating a switching pulse. Perturb & Observer algorithm can be used in the Maximum Power Point Tracking method for the Photo Voltaic system. By implementing Maximum Power Point Tracking with three separate solar panels as an input source to the 27-level Hybrid Multilevel Inverter. This proposed method can be simulated by using MATLAB/simulink. The result shown that the proposed method can achieve silky output wave forms, more flexibility in voltage range, and to reduce Total Harmonic Distortion in medium-voltage drives.

Keywords: Multi Carrier Pulse Width Modulation Technique (MCPWM), Multi Level Inverter (MLI), Maximum Power Point Tracking (MPPT), Perturb and Observer (P&O)

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Authors: Piyangkun Kukutapan, Siridech Boonsang

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The article proposes maximum power point tracking without mechanical sensor using Multilayer Perceptron Neural Network (MLPNN). The aim of article is to reduce the cost and complexity but still retain efficiency. The experimental is that duty cycle is generated maximum power, if it has suitable qualification. The measured data from DC generator, voltage (V), current (I), power (P), turnover rate of power (dP), and turnover rate of voltage (dV) are used as input for MLPNN model. The output of this model is duty cycle for driving the converter. The experiment implemented using Arduino Uno board. This diagram is compared to MPPT using MLPNN and P&O control (Perturbation and Observation control). The experimental results show that the proposed MLPNN based approach is more efficiency than P&O algorithm for this application.

Keywords: maximum power point tracking, multilayer perceptron netural network, optimal duty cycle, DC generator

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Authors: Sajeesh Sulaiman, Gomathisankar A., Aravind Devaraj, Aswin R., Vijay Kumar G., Rachana Raj

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Wind turbines are the next big answer to the emerging and ever-growing demand for electricity, and this need is increasing day by day. These high mast structures, whether on land or on the sea, has also become one of the big sources of electromagnetic interferences (EMI) in the not so distant past. With the emergence of the AC-AC converter and drawing of large power cables through the wind turbine towers has made this clean and efficient source of renewable energy to become one of the culprits in creating electromagnetic interference. This paper will present the sources of such EMIs, a comparison of radiated emissions (both electric and magnetic field) patterns in wind turbine towers for both onshore and offshore wind turbines and close look into the IEC 61400-40 (new standard for EMC design on wind turbine). At present, offshore wind turbines are tested in onshore facilities. This paper will present the anomaly in results for offshore wind turbines when tested in onshore, which the existing standards and the upcoming standards have failed to address.

Keywords: emissions, electric field, magnetic field, wind turbine, tower, standards and regulations

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Authors: Radhika Jain

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The nursing community in India face unique challenges ranging from lack of adequate career progression, low social status attached to the profession, poor nurse-to-patient ratio leading to heavy workload resulting in stress and burnout, lack of general recognition and the responsibility of often having to deal with the ire of the patients and their families. This study explores how a combination of Playback Theatre and Expressive Arts could be used as a very powerful tool to understand the concerns, and consequently as a self-care tool to bring about the sense of well-being and emotional awareness for the nurses. For the purpose of this study, Playback Theatre was used as an entry tool to understand the thoughts, feelings and concerns. Playback theatre is a unique improvisational form of theatre developed by Jonathan Fox and Jo Salas in 1975, in which audience share their own stories from their lives and the performers play them back through a range of improv techniques such as metaphor, poetry, music and movement. Playback Theatre helped in first warming them up to the idea of sharing and then gave them the confidence of a safe space to collectively go deeper into their emotional experiences. As the next step, structured sessions of Expressive Arts were conducted with the same set of nurses, for them to work on the issues and concerns they have (and which they shared during the Playback performance). These sessions were to enable longer engagements as many of the concerns expressed were related to perceptions and beliefs that have been ingrained over a period of time and hence it needs a longer engagement to be worked on in detail. The Expressive Art sessions helped in this regard. Expressive arts therapy combines psychology and the creative process to promote emotional growth and healing. The study was conducted at two places: one a geriatric centre and the other, a palliative care centre. The study revealed that concerns and challenges would not be identical across the nursing community or across similar types of health care organizations but would be specific to each organization or centre as the circumstances and set-up at each place would be different. At the geriatric centre, stress and burnout emerged as the main concerns while at the palliative care centre, the main concern that came up was around the difficulty the nurses faced in expressing emotions and in communicating their feelings. The objective analysis of the results of the study indicated how longer-term engagements using Expressive Arts as the modality helped the nurses have better awareness of their emotions and helped them develop tools of self-care tools while also tapping into their emotions to express and experience. The process of eliciting the main concerns from the nurses using a Playback Theatre performance and then following that with subsequent sessions of expressive arts helped the nurses in the way nurses approached their job and the reduced level of overwhelm that they felt.

Keywords: palliative care, nurses, self-care, expressive arts, playback theatre

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Authors: Balarabe Z. Ahmad, Anne-Lorène Vernay

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The emergence of electricity in Nigeria was dated back to 1896. The power plants have the potential to generate 12,522 MW of electric power. Whereas current dispatch is about 4,000 MW, access to electrification is about 60%, with consumption at 0.14 MWh/capita. The government embarked on energy reforms to mitigate energy poverty. The reform targeted the provision of electricity access to 75% of the population by 2020 and 90% by 2030. Growth of total electricity demand by a factor of 5 by 2035 had been projected. This means that Nigeria will require almost 530 TWh of electricity which can be delivered through generators with a capacity of 65 GW. Analogously, the geographical location of Nigeria has placed it in an advantageous position as the source of solar energy; the availability of a high sunshine belt is obvious in the country. The implication is that the far North, where energy poverty is high, equally has about twice the solar radiation as against southern Nigeria. Hence, the chance of generating solar electricity is 66% possible at 11850 x 103 GWh per year, which is one hundred times the current electricity consumption rate in the country. Harvesting these huge potentials may be a mirage if the entrepreneurs in the solar panel business are left with the conventional business models that are not uncertainty resilient. Currently, business entities in RE in Nigeria are uncertain of; accessing the national grid, purchasing potentials of cooperating organizations, currency fluctuation and interest rate increases. Uncertainties such as the security of projects and government policy are issues entrepreneurs must navigate to remain sustainable in the solar panel industry in Nigeria. The aim of this paper is to identify how entrepreneurial firms consider uncertainties in developing workable business models for commercializing solar energy projects in Nigeria. In an attempt to develop a novel business model, the paper investigated how entrepreneurial firms assess and navigate uncertainties. The roles of key stakeholders in helping entrepreneurs to manage uncertainties in the Nigeria RE sector were probed in the ongoing study. The study explored empirical uncertainties that are peculiar to RE entrepreneurs in Nigeria. A mixed-mode of research was embraced using qualitative data from face-to-face interviews conducted on the Solar Energy Entrepreneurs and the experts drawn from key stakeholders. Content analysis of the interview was done using Atlas. It is a nine qualitative tool. The result suggested that all stakeholders are required to synergize in developing an uncertainty resilient business model. It was opined that the RE entrepreneurs need modifications in the business recommendations encapsulated in the energy policy in Nigeria to strengthen their capability in delivering solar energy solutions to the yawning Nigerians.

Keywords: uncertainties, entrepreneurial, business model, solar-panel

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Authors: Debabrata Das

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This paper explains how to design a regulation loop for a power supply circuit. It also discusses the need of a regulation loop and the improvement of a circuit with regulation loop. A sample design is used to demonstrate how to use PSpice to design feedback loop to control output voltage of a power supply and how to check if the power supply is stable or oscillatory. A sample design is made using a specific Integrated Circuit (IC) available in the PSpice library. A designer can experiment feedback loop design using Cadence Pspice tool. PSpice is easy to use, reliable, and convenient. To test a feedback loop, generally, engineers use trial and error method with the hardware which takes a lot of time and manpower. Moreover, it is expensive because component and Printed Circuit Board (PCB) may go bad. PSpice can be used by designers to test their loop designs without using hardware circuits. A designer can save time, cost, manpower and simulate his/her power supply circuit accurately before making a real hardware using this software package.

Keywords: power electronics, feedback loop, regulation, stability, pole, zero, oscillation

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Authors: Shahrukh Ahmad, Purnendu Bose

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Algal-Bacterial photobioreactors (ABPBRs) have emerged as a promising technology for sustainable biomass production and wastewater treatment. Nutrient removal is seldom done in sewage treatment plants and large volumes of wastewater which still have nutrients are being discharged and that can lead to eutrophication. That is why ABPBR plays a vital role in wastewater treatment. However, improving the efficiency of ABPBR remains a significant challenge. This study aims to enhance ABPBR efficiency by focusing on two key aspects: nutrient removal and cost-effective optimization of the light source. By integrating nutrient removal and cost analysis for light source optimization, this study proposes practical strategies for improving ABPBR efficiency. To reduce organic carbon and convert ammonia to nitrates, domestic wastewater from a 130 MLD sewage treatment plant (STP) was aerated with a hydraulic retention time (HRT) of 2 days. The treated supernatant had an approximate nitrate and phosphate values of 16 ppm as N and 6 ppm as P, respectively. This supernatant was then fed into the ABPBR, and the removal of nutrients (nitrate as N and phosphate as P) was observed using different colored LED bulbs, namely white, blue, red, yellow, and green. The ABPBR operated with a 9-hour light and 3-hour dark cycle, using only one color of bulbs per cycle. The study found that the white LED bulb, with a photosynthetic photon flux density (PPFD) value of 82.61 µmol.m-2 .sec-1 , exhibited the highest removal efficiency. It achieved a removal rate of 91.56% for nitrate and 86.44% for phosphate, surpassing the other colored bulbs. Conversely, the green LED bulbs showed the lowest removal efficiencies, with 58.08% for nitrate and 47.48% for phosphate at an HRT of 5 days. The quantum PAR (Photosynthetic Active Radiation) meter measured the photosynthetic photon flux density for each colored bulb setting inside the photo chamber, confirming that white LED bulbs operated at a wider wavelength band than the others. Furthermore, a cost comparison was conducted for each colored bulb setting. The study revealed that the white LED bulb had the lowest average cost (Indian Rupee)/light intensity (µmol.m-2 .sec-1 ) value at 19.40, while the green LED bulbs had the highest average cost (INR)/light intensity (µmol.m-2 .sec-1 ) value at 115.11. Based on these comparative tests, it was concluded that the white LED bulbs were the most efficient and costeffective light source for an algal photobioreactor. They can be effectively utilized for nutrient removal from secondary treated wastewater which helps in improving the overall wastewater quality before it is discharged back into the environment.

Keywords: algal bacterial photobioreactor, domestic wastewater, nutrient removal, led bulbs

Procedia PDF Downloads 25

Authors: Marcin Jakiel, Maria Kurek, Karolina Gutkowska, Sylwia Sanakiewicz, Dominika Stolarczyk, Jakub Batko, Rafał Jakiel, Mateusz K. Hołda

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Proper imaging of the interventricular septum during endocavital lead implantation is essential for successful procedure. The interventricular septum is located oblique to the 3 main body planes and forms angles of 44.56° ± 7.81°, 45.44° ± 7.81°, 62.49° (IQR 58.84° - 68.39°) with the sagittal, frontal and transverse planes, respectively. The optimal left anterior oblique (LAO) projection is to have the septum aligned along the radiation beam and will be obtained for an angle of 53.24° ± 9,08°, while the best visualization of the septal surface in the right anterior oblique (RAO) projection is obtained by using an angle of 45.44° ± 7.81°. In addition, the RAO angle (p=0.003) and the septal slope to the transverse plane (p=0.002) are larger in the male group, but the LAO angle (p=0.003) and the dihedral angle that the septum forms with the sagittal plane (p=0.003) are smaller, compared to the female group. Analyzing the optimal RAO angle in cross-sections lying at the level of the connections of the septum with the free wall of the right ventricle from the front and back, we obtain slightly smaller angle values, i.e. 41.11° ± 8.51° and 43.94° ± 7.22°, respectively. As the septum is directed leftward in the apical region, the optimal RAO angle for this area decreases (16.49° ± 7,07°) and does not show significant differences between the male and female groups (p=0.23). Within the right ventricular apex, there is a cavity formed by the apical segment of the interventricular septum and the free wall of the right ventricle with a depth of 12.35mm (IQR 11.07mm - 13.51mm). The length of the septum measured in longitudinal section, containing 4 heart cavities, is 73.03mm ± 8.06mm. With the left ventricular septal wall formed by the interventricular septum in the apical region at a length of 10.06mm (IQR 8.86 - 11.07mm) already lies outside the right ventricle. Both mentioned lengths are significantly larger in the male group (p<0.001). For proper imaging of the septum from the right ventricular side, an oblique position of the visualization devices is necessary. Correct determination of the RAO and LAO angle during the procedure allows to improve the procedure performed, and possible modification of the visual field when moving in the anterior, posterior and apical directions of the septum will avoid complications. Overlooking the change in the direction of the interventricular septum in the apical region and a significant decrease in the RAO angle can result in implantation of the lead into the free wall of the right ventricle with less effective pacing and even complications such as wall perforation and cardiac tamponade. The demonstrated gender differences can also be helpful in setting the right projections. A necessary addition to the analysis will be a description of the area of the ventricular septum, which we are currently working on using autopsy material.

Keywords: anatomical variability, angle, electrocardiological procedure, intervetricular septum

Procedia PDF Downloads 75

Authors: Mir Mohammad Badrul Hasan, Anwar Abdkader, Chokri Cherif

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With the increasing demand and use of carbon fibre reinforced composites (CFRC), disposal of the carbon fibres (CF) and end of life composite parts is gaining tremendous importance on the issue especially of sustainability. Furthermore, a number of processes (e. g. pyrolysis, solvolysis, etc.) are available currently to obtain recycled CF (rCF) from end-of-life CFRC. Since the CF waste or rCF are neither allowed to be thermally degraded nor landfilled (EU Directive 1999/31/EC), profitable recycling and re-use concepts are urgently necessary. Currently, the market for materials based on rCF mainly consists of random mats (nonwoven) made from short fibres. The strengths of composites that can be achieved from injection-molded components and from nonwovens are between 200-404 MPa and are characterized by low performance and suitable for non-structural applications such as in aircraft and vehicle interiors. On the contrary, spinning rCF to yarn constructions offers good potential for higher CFRC material properties due to high fibre orientation and compaction of rCF. However, no investigation is reported till yet on the direct comparison of the mechanical properties of thermoplastic CFRC manufactured from virgin CF filament yarn and spun yarns from staple rCF. There is a lack of understanding on the level of performance of the composites that can be achieved from hybrid yarns consisting of rCF and PA6 fibres. In this drop back, extensive research works are being carried out at the Textile Machinery and High-Performance Material Technology (ITM) on the development of new thermoplastic CFRC from hybrid yarns consisting of rCF. For this purpose, a process chain is developed at the ITM starting from fibre preparation to hybrid yarns manufacturing consisting of staple rCF by mixing with thermoplastic fibres. The objective is to apply such hybrid yarns for the manufacturing of load bearing textile reinforced thermoplastic CFRCs. In this paper, the development of innovative multi-component core-sheath hybrid yarn structures consisting of staple rCF and polyamide 6 (PA 6) on a DREF-3000 friction spinning machine is reported. Furthermore, Unidirectional (UD) CFRCs are manufactured from the developed hybrid yarns, and the mechanical properties of the composites such as tensile and flexural properties are analyzed. The results show that the UD composite manufactured from the developed hybrid yarns consisting of staple rCF possesses approximately 80% of the tensile strength and E-module to those produced from virgin CF filament yarn. The results show a huge potential of the DREF-3000 friction spinning process to develop composites from rCF for high-performance applications.

Keywords: recycled carbon fibres, hybrid yarn, friction spinning, thermoplastic composite

Procedia PDF Downloads 228

Authors: Martin Pellon Consunji

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Due to the rise in popularity of Bitcoin and other crypto assets as a store of wealth and speculative investment, there is an ever-growing demand for automated trading tools, such as bots, in order to gain an advantage over the market. Traditionally, trading in the stock market was done by professionals with years of training who understood patterns and exploited market opportunities in order to gain a profit. However, nowadays a larger portion of market participants are at minimum aided by market-data processing bots, which can generally generate more stable signals than the average human trader. The rise in trading bot usage can be accredited to the inherent advantages that bots have over humans in terms of processing large amounts of data, lack of emotions of fear or greed, and predicting market prices using past data and artificial intelligence, hence a growing number of approaches have been brought forward to tackle this task. However, the general limitation of these approaches can still be broken down to the fact that limited historical data doesn’t always determine the future, and that a lot of market participants are still human emotion-driven traders. Moreover, developing markets such as those of the cryptocurrency space have even less historical data to interpret than most other well-established markets. Due to this, some human traders have gone back to the tried-and-tested traditional technical analysis tools for exploiting market patterns and simplifying the broader spectrum of data that is involved in making market predictions. This paper proposes a method which uses neuro evolution techniques on both sentimental data and, the more traditionally human-consumed, technical analysis data in order to gain a more accurate forecast of future market behavior and account for the way both automated bots and human traders affect the market prices of Bitcoin and other cryptocurrencies. This study’s approach uses evolutionary algorithms to automatically develop increasingly improved populations of bots which, by using the latest inflows of market analysis and sentimental data, evolve to efficiently predict future market price movements. The effectiveness of the approach is validated by testing the system in a simulated historical trading scenario, a real Bitcoin market live trading scenario, and testing its robustness in other cryptocurrency and stock market scenarios. Experimental results during a 30-day period show that this method outperformed the buy and hold strategy by over 260% in terms of net profits, even when taking into consideration standard trading fees.

Keywords: neuro-evolution, Bitcoin, trading bots, artificial neural networks, technical analysis, evolutionary algorithms

Procedia PDF Downloads 94

Authors: Kai Way Li, Lang Gan

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Slip &Fall are common in Taiwan. They could result in injuries and even fatalities. Official statistics indicate that more than 15% of all occupational incidences were slip/fall related. All the workers in Taiwan are required by the law to join the worker’s insurance program administered by the Bureau of Labor Insurance (BLI). The BLI is a government agency under the supervision of the Ministry of Labor. Workers claim with the BLI for insurance compensations when they suffer fatalities or injuries at work. Injuries statistics based on worker’s compensation claims were rarely studied. The objective of this study was to quantify the injury statistics and financial cost due to slip-fall incidences based on the BLI compensation records. Compensation records in the BLI during 2007 to 2013 were retrieved. All the original application forms, approval opinions, results for worker’s compensations were in hardcopy and were stored in the BLI warehouses. Xerox copies of the claims, excluding the personal information of the applicants (or the victim if passed away), were obtained. The content in the filing forms were coded in an Excel worksheet for further analyses. Descriptive statistics were performed to analyze the data. There were a total of 35,024 claims including 82 deaths, 878 disabilities, and 34,064 injuries/illnesses which were slip/fall related. It was found that the average losses for the death cases were 40 months. The total dollar amount for these cases paid was 86,913,195 NTD. For the disability cases, the average losses were 367.36 days. The total dollar amount for these cases paid was almost 2.6 times of those for the death cases (233,324,004 NTD). For the injury/illness cases, the average losses for the illness cases were 58.78 days. The total dollar amount for these cases paid was approximately 13 times of those of the death cases (1134,850,821 NTD). For the applicants/victims, 52.3% were males. There were more males than females for the deaths, disability, and injury/illness cases. Most (57.8%) of the female victims were between 45 to 59 years old. Most of the male victims (62.6%) were, on the other hand, between 25 to 39 years old. Most of the victims were in manufacturing industry (26.41%), next the construction industry (22.20%), and next the retail industry (13.69%). For the fatality cases, head injury was the main problem for immediate or eventual death (74.4%). For the disability case, foot (17.46%) and knee (9.05%) injuries were the leading problems. The compensation claims other than fatality and disability were mainly associated with injuries of the foot (18%), hand (12.87%), knee (10.42%), back (8.83%), and shoulder (6.77%). The slip/fall cases studied indicate that the ratios among the death, disability, and injury/illness counts were 1:10:415. The ratios of dollar amount paid by the BLI for the three categories were 1:2.6:13. Such results indicate the significance of slip-fall incidences resulting in different severity. Such information should be incorporated in to slip-fall prevention program in industry.

Keywords: epidemiology, slip and fall, social burden, workers’ compensation

Procedia PDF Downloads 303

Authors: Gilda Santos, Rita Marques, Francisca Marques, João Ribeiro, André Fonseca, João M. Miranda, João B. L. M. Campos, Soraia F. Neves

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Every year, an unacceptable number of firefighters are seriously burned during firefighting operations, with some of them eventually losing their life. Although thermal protective clothing research and development has been searching solutions to minimize firefighters heat load and skin burns, currently commercially available solutions focus in solving isolated problems, for example, radiant heat or water-vapor resistance. Therefore, episodes of severe burns and heat strokes are still frequent. Taking this into account, a consortium composed by Portuguese entities has joined synergies to develop an innovative protective clothing system by following a procedure based on the application of numerical models to optimize the design and using a combinationof protective clothing components disposed in different layers. Recently, it has been shown that Phase Change Materials (PCMs) can contribute to the reduction of potential heat hazards in fire extinguish operations, and consequently, their incorporation into firefighting protective clothing has advantages. The greatest challenge is to integrate these materials without compromising garments ergonomics and, at the same time, accomplishing the International Standard of protective clothing for firefighters – laboratory test methods and performance requirements for wildland firefighting clothing. The incorporation of PCMs into the firefighter's protective jacket will result in the absorption of heat from the fire and consequently increase the time that the firefighter can be exposed to it. According to the project studies and developments, to favor a higher use of the PCM storage capacityand to take advantage of its high thermal inertia more efficiently, the PCM layer should be closer to the external heat source. Therefore, in this stage, to integrate PCMs in firefighting clothing, a mock-up of a vest specially designed to protect the torso (back, chest and abdomen) and to be worn over a fire-resistant jacketwas envisaged. Different configurations of PCMs, as well as multilayer approaches, were studied using suitable joining technologies such as bonding, ultrasound, and radiofrequency. Concerning firefighter’s protective clothing, it is important to balance heat protection and flame resistance with comfort parameters, namely, thermaland water-vapor resistances. The impact of the most promising solutions regarding thermal comfort was evaluated to refine the performance of the global solutions. Results obtained with experimental bench scale model and numerical simulation regarding the integration of PCMs in a vest designed as protective clothing for firefighters will be presented.

Keywords: firefighters, multilayer system, phase change material, thermal protective clothing

Procedia PDF Downloads 124

Authors: Huimin Liu, Li Xiang, Yue Liu, Jing Wang

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Background: As one of typical case for the developing countries who are stepping into the aging times globally, more and more older people in China might face the problem of which they could not maintain normal life due to the functional disability. While the government take efforts to build long-term care system and further carry out related policies for the core concept, there is still lack of strong evidence to evaluating the profile of disability states in the elderly population and its transition rate. It has been proved that disability is a dynamic condition of the person rather than irreversible so it means possible to intervene timely on them who might be in a risk of severe disability. Objective: The aim of this study was to depict the picture of the disability transferring status of the older people in China, and then find out individual characteristics that change the state of disability to provide theory basis for disability prevention and early intervention among elderly people. Methods: Data for this study came from the 2011 baseline survey and the 2013 follow-up survey of the China Health and Retirement Longitudinal Study (CHARLS). Normal ADL function, 1~2 ADLs disability,3 or above ADLs disability and death were defined from state 1 to state 4. Multi-state Markov model was applied and the four-state homogeneous model with discrete states and discrete times from two visits follow-up data was constructed to explore factors for various progressive stages. We modeled the effect of explanatory variables on the rates of transition by using a proportional intensities model with covariate, such as gender. Result: In the total sample, state 2 constituent ratio is nearly about 17.0%, while state 3 proportion is blow the former, accounting for 8.5%. Moreover, ADL disability statistics difference is not obvious between two years. About half of the state 2 in 2011 improved to become normal in 2013 even though they get elder. However, state 3 transferred into the proportion of death increased obviously, closed to the proportion back to state 2 or normal functions. From the estimated intensities, we see the older people are eleven times as likely to develop at 1~2 ADLs disability than dying. After disability onset (state 2), progression to state 3 is 30% more likely than recovery. Once in state 3, a mean of 0.76 years is spent before death or recovery. In this model, a typical person in state 2 has a probability of 0.5 of disability-free one year from now while the moderate disabled or above has a probability of 0.14 being dead. Conclusion: On the long-term care cost considerations, preventive programs for delay the disability progression of the elderly could be adopted based on the current disabled state and main factors of each stage. And in general terms, those focusing elderly individuals who are moderate or above disabled should go first.

Keywords: Markov model, elderly people, disability, transition intensity

Procedia PDF Downloads 258

Authors: Angela Cristina Da F. De Oliveira, Salma E. Asmar, Norbert P. Battlori, Yaz Vera, Uriel R. Valencia, Tâmara D. Borges, Antoni D. Bueno, Leandro B. Costa

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The present study aimed to evaluate the replacement of 5% of starch per 5% of sunflower oil (SO) on meat quality and animal welfare of growing and finishing pigs (Iberic x Duroc), exposed to a heat stress environment. The experiment lasted 90 days, and it was carried out in a randomized block design, in a 2 x 2 factorial, composed of two diets (starch or sunflower oil (with or without) and two feed intake management (ad libitum and restriction). Seventy-two crossbred males (51± 6,29 kg body weight - BW) were housed in climate-controlled rooms, in collective pens and exposed to heat stress environment (32°C; 35% to 50% humidity). The treatments studies were: 1) control diet (5% starch x 0% SO) with ad libitum intake (n = 18); 2) SO diet (replacement of 5% of starch per 5% of SO) with ad libitum intake (n = 18); 3) control diet with restriction feed intake (n = 18); or 4) SO diet with restriction feed intake (n = 18). Feed were provided in two phases, 50-100 Kg BW for growing and 100-140 Kg BW for finishing, respectively. Within welfare evaluations, dirtiness score was evaluated all morning during ninety days of the experiment. The presence of manure was individually measured based on one side of the pig´s body and scored according to: 0 (less than 20% of the body surface); 1 (more than 20% but less than 50% of the body surface); 2 (over 50% of the body surface). After the experimental period, when animals reach 130-140 kg BW, they were slaughtered using carbon dioxide (CO2) stunning. Carcass weight, leanness and fat content, measured at the last rib, were recorded within 20 min post-mortem (PM). At 24h PM, pH, electrical conductivity and color measures (L, a*, b*) were recorded in the Longissimus thoracis and Semimembranosus muscles. Data shown no interaction between diet (control x SO) and management feed intake (ad libitum x restriction) on the meat quality parameters. Animals in ad libitum management presented an increase (p < 0.05) on BW, carcass weight (CW), back fat thickness (BT), and intramuscular fat content (IM) when compared with animals in restriction management. In contrast, animals in restriction management showing a higher (p < 0.05) carcass yield, percentage of lean and loin thickness. To welfare evaluations, the interaction between diet and management feed intake did not influence the degree of dirtiness. Although, the animals that received SO diet, independently of the management, were cleaner than animals in control group (p < 0,05), which, for pigs, demonstrate an important strategy to reduce body temperature. Based in our results, the diet and management feed intake had a significant influence on meat quality and animal welfare being considered efficient nutritional strategies to reduce heat stress and improved meat quality.

Keywords: dirtiness, environment, meat, pig

Procedia PDF Downloads 234

Authors: Piotr Wisniewski, Sławomir Dykas

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Condensation has a negative impact on turbomachinery efficiency in many energy processes.In technical applications, it is often impossible to dry the working fluid at the nozzle inlet. One of the most popular working fluid is atmospheric air that always contains water in form of steam, liquid, or ice crystals. Moreover, it always contains some amount of suspended particles which influence the phase change process. It is known that the phenomena of evaporation or condensation are connected with release or absorption of latent heat, what influence the fluid physical properties and might affect the machinery efficiency therefore, the phase transition has to be taken under account. This researchpresents an attempt to evaluate the impact of solid and liquid particles suspended in the air on the expansion of moist air in a low expansion rate, i.e., with expansion rate, P≈1000s⁻¹. The numerical study supported by analytical and experimental research is presented in this work. The experimental study was carried out using an in-house experimental test rig, where nozzle was examined for different inlet air relative humidity values included in the range of 25 to 51%. The nozzle was tested for a supersonic flow as well as for flow with shock waves induced by elevated back pressure. The Schlieren photography technique and measurement of static pressure on the nozzle wall were used for qualitative identification of both condensation and shock waves. A numerical model validated against experimental data available in the literature was used for analysis of occurring flow phenomena. The analysis of the suspended particles number, diameter, and character (solid or liquid) revealed their connection with heterogeneous condensation importance. If the expansion of fluid without suspended particlesis considered, the condensation triggers so called condensation wave that appears downstream the nozzle throat. If the solid particles are considered, with increasing number of them, the condensation triggers upwind the nozzle throat, decreasing the condensation wave strength. Due to the release of latent heat during condensation, the fluid temperature and pressure increase, leading to the shift of normal shock upstream the flow. Owing relatively large diameters of the droplets created during heterogeneous condensation, they evaporate partially on the shock and continues to evaporate downstream the nozzle. If the liquid water particles are considered, due to their larger radius, their do not affect the expanding flow significantly, however might be in major importance while considering the compression phenomena as they will tend to evaporate on the shock wave. This research proves the need of further study of phase change phenomena in supersonic flow especially considering the interaction of droplets with the aerodynamic waves in the flow.

Keywords: aerodynamics, computational fluid dynamics, condensation, moist air, multi-phase flows

Procedia PDF Downloads 88

Authors: Frazer McDonald Ng'oma

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Online Learning in Malawi has only immersed in recent years due to the need to increase access to higher education, the need to accommodate upgrading students who wish to study on a part time basis while still continuing their work, and the COVID-19 pandemic, which forced the closure of schools resulting in academic institutions seeking alternative modes of teaching and Learning to ensure continued teaching and Learning. Realizing that this mode of Learning is becoming a norm, institutions of higher Learning have started pioneering online post-graduate programs from which they can draw lessons before fully implementing it in undergraduate programs. Online learning pedagogy has not been fully grasped and institutions are still experimenting with this mode of Learning until online Learning guiding policies are created and its standards improved. This single case descriptive qualitative research study sought to investigate online postgraduate students’ perceptions and experiences with Student to student interactive pedagogy in their programs. The results of the study are to inform institutions and educators how to structure their programs to ensure that their students get the full satisfaction. 25 Masters students in 3 recently introduced online programs at Kamuzu University of Health Sciences (KUHES), were engaged; 19 were interviewed and 6 responded to questionnaires. The findings from the students were presented and categorized in themes and subthemes that emerged from the qualitative data that was collected and analysed following Colaizzi’s framework for data analysis that resulted in themes formulation. Findings revealed that Student to student interactions occurred in the online programme during live sessions, on class Whatsapp group, in discussion boards as well as on emails. Majority of the students (n=18) felt the level of students’ interaction initiated by the institution was too much, referring to mandatory interactions activities like commenting in discussion boards and attending to live sessons. Some participants (n=7) were satisfied with the level of interaction and also pointed out that they would be fine with more program-initiated student–to–student interactions. These participants attributed having been out of school for some time as a reason for needing peer interactions citing that it is already difficult to get back to a traditional on-campus school after some time, let alone an online class where there is no physical interaction with other students. In general, majority of the participants (n=18) did not value Student to student interaction in online Learning. The students suggested that having intensive student-to-student interaction in postgraduate online studies does not need to be a high priority for the institution and they further recommended that if a lecturer decides to incorporate student-to-student activities into a class, they should be optional.

Keywords: online learning, interactions, student interactions, post graduate students

Procedia PDF Downloads 48

Authors: Angeliki Gkiouzeli, Christine Rotonda, Elise Eby, Claire Touchet, Marie-Jo Brennstuhl, Cyril Tarquinio

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Resilience is a psychological concept of possible relevance to the development and maintenance of chronic pain (CP). It refers to the ability of individuals to maintain reasonably healthy levels of physical and psychological functioning when exposed to an isolated and potentially highly disruptive event. Extensive research in recent years has supported the importance of this concept in the CP literature. Increased levels of resilience were associated with lower levels of perceived pain intensity and better mental health outcomes in adults with persistent pain. The ongoing project seeks to include the concept of pain-specific resilience in the French literature in order to provide more appropriate measures for assessing and understanding the complexities of CP in the near future. To the best of our knowledge, there is currently no validated version of the pain-specific resilience measure, the Pain Resilience scale (PRS), for French-speaking populations. Therefore, the present work aims to address this gap, firstly by performing a linguistic and cultural translation of the scale into French and secondly by studying the internal validity and reliability of the PRS for French CP populations. The forward-translation-back translation methodology was used to achieve as perfect a cultural and linguistic translation as possible according to the recommendations of the COSMIN (Consensus-based Standards for the selection of health Measurement Instruments) group, and an online survey is currently conducted among a representative sample of the French population suffering from CP. To date, the survey has involved one hundred respondents, with a total target of around three hundred participants at its completion. We further seek to study the metric properties of the French version of the PRS, ''L’Echelle de Résilience à la Douleur spécifique pour les Douleurs Chroniques'' (ERD-DC), in French patients suffering from CP, assessing the level of pain resilience in the context of CP. Finally, we will explore the relationship between the level of pain resilience in the context of CP and other variables of interest commonly assessed in pain research and treatment (i.e., general resilience, self-efficacy, pain catastrophising, and quality of life). This study will provide an overview of the methodology used to address our research objectives. We will also present for the first time the main findings and further discuss the validity of the scale in the field of CP research and pain management. We hope that this tool will provide a better understanding of how CP-specific resilience processes can influence the development and maintenance of this disease. This could ultimately result in better treatment strategies specifically tailored to individual needs, thus leading to reduced healthcare costs and improved patient well-being.

Keywords: chronic pain, pain measure, pain resilience, questionnaire adaptation

Procedia PDF Downloads 64

Authors: Asma Ben Rhouma, Mahmoud Hamouda

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The delta inverter is considered as the reduced three-phase dc/ac converter topology. It contains only three two-quadrant power switches compared to six in the conventional one. This reduced power conversion topology is widely considered in many industrial applications, such as electric traction and large photovoltaic systems. This paper is focused on a new sinusoidal pulse width modulation algorithm (SPWM) developed for the delta inverter. As an unconventional inverter’s structure, irregular modulating functions waveforms of the SPWM switching technique are generated. The performances of the proposed SPWM technique was proven through computer simulations carried out on a delta inverter feeding a three-phase RL load. Digital Signal Processor (DSP) implementation of the novel SPWM algorithm have been realized on a laboratory prototype of the delta inverter feeding an RL load and a squirrel cage induction motor. Experimental results have highlighted its high performances under the proposed SPWM method.

Keywords: delta inverter, SPWM, simulation, DSP implementation

Procedia PDF Downloads 134

Authors: Tom Elias, Kiran G. Shirlal

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Coastal erosion is one of the major issue faced by maritime countries, globally. More than 1200 km stretch of Indian coastline is marked eroding. There have been numerous attempts to impede the erosion rate and to attain equilibrium beach profiles. High cost and unavailability of natural rocks forced coastal engineers to find alternatives for conventional hard options like seawalls and groynes. Geosynthetic containment systems, emerged in the mid 20th century proved promising in catering coastal protection in countries like Australia, Germany and United States. The present study aims at reviewing Indian timeline of protection works that uses geosynthetic containment systems. Indian exploration regarding geosynthetic containment system dates back to early 2000s. Generally, protection structures use geosynthetics in the form of Geotubes, Geocontainers, and Geobags with Geotubes being most widely used in the form of submerged reefs, seawalls, groynes and breakwaters. Sand and dredged waste are used to fill these containment systems with calculated sand fill ratio. Reviewing the prominent protection works constructed in the east and west coast of India provides an insight into benefits and the difficulties faced by the practical installation. Initially, geosynthetic structures were considered as a temporary protection method prior to the construction of some other hard structure. Later Dahanu, Hamala and Pentha experiences helped in establishing geotubes as an alternative to conventional structures. Nearshore geotubes reefs aimed to attain equilibrium beach served its purpose in Hamala and Dahanu, Maharashtra, while reef constructed at Candolim, Goa underwent serious damage due to Toe Scour. In situ filling by pumping of sand slurry as in case of Shankarpur Seawall, West Bengal remains as a major concern. Geosynthetic systems supplemented by gabions and rock armours improves the wave dissipation, stability and reflection characteristics as implied in Pentha Coast, Odisha, Hazira, Gujarat and Uppada, Andhra Pradesh. Keeping improper design and deliberate destruction by vandals apart, geosynthetic containment systems offer a cost-effective alternative to conventional coastal protection methods in India. Additionally, geosynthetics supports marine growth in its surface which enhances its demand as an eco-friendly material and encourages usage.

Keywords: coastal protection, geotubes, geobags, geocontainers

Procedia PDF Downloads 130

Authors: James Gallagher, Phillip Benachour

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As location aware mobile technologies become ever more omnipresent, the prospect of exploiting their context awareness to enforce learning approaches thrives. Utilizing the growing acceptance of ubiquitous computing, and the steady progress both in accuracy and battery usage of pervasive devices, we present a case study of remote location viewing, how the application can be utilized to support mobile learning in situ using an existing scenario. Through the case study we introduce a new innovative application: Mobipeek based around a request/response protocol for the viewing of a remote location and explore how this can apply both as part of a teacher lead activity and informal learning situations. The system developed allows a user to select a point on a map, and send a request. Users can attach messages alongside time and distance constraints. Users within the bounds of the request can respond with an image, and accompanying message, providing context to the response. This application can be used alongside a structured learning activity such as the use of mobile phone cameras outdoors as part of an interactive lesson. An example of a learning activity would be to collect photos in the wild about plants, vegetation, and foliage as part of a geography or environmental science lesson. Another example could be to take photos of architectural buildings and monuments as part of an architecture course. These images can be uploaded then displayed back in the classroom for students to share their experiences and compare their findings with their peers. This can help to fosters students’ active participation while helping students to understand lessons in a more interesting and effective way. Mobipeek could augment the student learning experience by providing further interaction with other peers in a remote location. The activity can be part of a wider study between schools in different areas of the country enabling the sharing and interaction between more participants. Remote location viewing can be used to access images in a specific location. The choice of location will depend on the activity and lesson. For example architectural buildings of a specific period can be shared between two or more cities. The augmentation of the learning experience can be manifested in the different contextual and cultural influences as well as the sharing of images from different locations. In addition to the implementation of Mobipeek, we strive to analyse this application, and a subset of other possible and further solutions targeted towards making learning more engaging. Consideration is given to the benefits of such a system, privacy concerns, and feasibility of widespread usage. We also propose elements of “gamification”, in an attempt to further the engagement derived from such a tool and encourage usage. We conclude by identifying limitations, both from a technical, and a mobile learning perspective.

Keywords: context aware, location aware, mobile learning, remote viewing

Procedia PDF Downloads 267