Search results for: petrography analysis
1495 Computational Fluid Dynamics (CFD) Calculations of the Wind Turbine with an Adjustable Working Surface
Authors: Zdzislaw Kaminski, Zbigniew Czyz, Krzysztof Skiba
Abstract:
This paper discusses the CFD simulation of a flow around a rotor of a Vertical Axis Wind Turbine. Numerical simulation, unlike experiments, enables us to validate project assumptions when it is designed and avoid a costly preparation of a model or a prototype for a bench test. CFD simulation enables us to compare characteristics of aerodynamic forces acting on rotor working surfaces and define operational parameters like torque or power generated by a turbine assembly. This research focused on the rotor with the blades capable of modifying their working surfaces, i.e. absorbing wind kinetic energy. The operation of this rotor is based on adjusting angular aperture α of the top and bottom parts of the blades mounted on an axis. If this angular aperture α increases, the working surface which absorbs wind kinetic energy also increases. The operation of turbines is characterized by parameters like the angular aperture of blades, power, torque, speed for a given wind speed. These parameters have an impact on the efficiency of assemblies. The distribution of forces acting on the working surfaces in our turbine changes according to the angular velocity of the rotor. Moreover, the resultant force from the force acting on an advancing blade and retreating blade should be as high as possible. This paper is part of the research to improve an efficiency of a rotor assembly. Therefore, using simulation, the courses of the above parameters were studied in three full rotations individually for each of the blades for three angular apertures of blade working surfaces, i.e. 30 °, 60 °, 90 °, at three wind speeds, i.e. 4 m / s, 6 m / s, 8 m / s and rotor speeds ranging from 100 to 500 rpm. Finally, there were created the characteristics of torque coefficients and power as a function of time for each blade separately and for the entire rotor. Accordingly, the correlation between the turbine rotor power as a function of wind speed for varied values of rotor rotational speed. By processing this data, the correlation between the power of the turbine rotor and its rotational speed for each of the angular aperture of the working surfaces was specified. Finally, the optimal values, i.e. of the highest output power for given wind speeds were read. The research results in receiving the basic characteristics of turbine rotor power as a function of wind speed for the three angular apertures of the blades. Given the nature of rotor operation, the growth in the output turbine can be estimated if angular aperture of the blades increases. The controlled adjustment of angle α enables a smooth adjustment of power generated by a turbine rotor. If wind speed is significant, this type of adjustment enables this output power to remain at the same level (by reducing angle α) with no risk of damaging a construction. This work has been financed by the Polish Ministry of Science and Higher Education.Keywords: computational fluid dynamics, numerical analysis, renewable energy, wind turbine
Procedia PDF Downloads 2151494 Measuring Emotion Dynamics on Facebook: Associations between Variability in Expressed Emotion and Psychological Functioning
Authors: Elizabeth M. Seabrook, Nikki S. Rickard
Abstract:
Examining time-dependent measures of emotion such as variability, instability, and inertia, provide critical and complementary insights into mental health status. Observing changes in the pattern of emotional expression over time could act as a tool to identify meaningful shifts between psychological well- and ill-being. From a practical standpoint, however, examining emotion dynamics day-to-day is likely to be burdensome and invasive. Utilizing social media data as a facet of lived experience can provide real-world, temporally specific access to emotional expression. Emotional language on social media may provide accurate and sensitive insights into individual and community mental health and well-being, particularly with focus placed on the within-person dynamics of online emotion expression. The objective of the current study was to examine the dynamics of emotional expression on the social network platform Facebook for active users and their relationship with psychological well- and ill-being. It was expected that greater positive and negative emotion variability, instability, and inertia would be associated with poorer psychological well-being and greater depression symptoms. Data were collected using a smartphone app, MoodPrism, which delivered demographic questionnaires, psychological inventories assessing depression symptoms and psychological well-being, and collected the Status Updates of consenting participants. MoodPrism also delivered an experience sampling methodology where participants completed items assessing positive affect, negative affect, and arousal, daily for a 30-day period. The number of positive and negative words in posts was extracted and automatically collated by MoodPrism. The relative proportion of positive and negative words from the total words written in posts was then calculated. Preliminary analyses have been conducted with the data of 9 participants. While these analyses are underpowered due to sample size, they have revealed trends that greater variability in the emotion valence expressed in posts is positively associated with greater depression symptoms (r(9) = .56, p = .12), as is greater instability in emotion valence (r(9) = .58, p = .099). Full data analysis utilizing time-series techniques to explore the Facebook data set will be presented at the conference. Identifying the features of emotion dynamics (variability, instability, inertia) that are relevant to mental health in social media emotional expression is a fundamental step in creating automated screening tools for mental health that are temporally sensitive, unobtrusive, and accurate. The current findings show how monitoring basic social network characteristics over time can provide greater depth in predicting risk and changes in depression and positive well-being.Keywords: emotion, experience sampling methods, mental health, social media
Procedia PDF Downloads 2491493 An Integrated Theoretical Framework on Mobile-Assisted Language Learning: User’s Acceptance Behavior
Authors: Gyoomi Kim, Jiyoung Bae
Abstract:
In the field of language education research, there are not many tries to empirically examine learners’ acceptance behavior and related factors of mobile-assisted language learning (MALL). This study is one of the few attempts to propose an integrated theoretical framework that explains MALL users’ acceptance behavior and potential factors. Constructs from technology acceptance model (TAM) and MALL research are tested in the integrated framework. Based on previous studies, a hypothetical model was developed. Four external variables related to the MALL user’s acceptance behavior were selected: subjective norm, content reliability, interactivity, self-regulation. The model was also composed of four other constructs: two latent variables, perceived ease of use and perceived usefulness, were considered as cognitive constructs; attitude toward MALL as an affective construct; behavioral intention to use MALL as a behavioral construct. The participants were 438 undergraduate students who enrolled in an intensive English program at one university in Korea. This particular program was held in January 2018 using the vacation period. The students were given eight hours of English classes each day from Monday to Friday for four weeks and asked to complete MALL courses for practice outside the classroom. Therefore, all participants experienced blended MALL environment. The instrument was a self-response questionnaire, and each construct was measured by five questions. Once the questionnaire was developed, it was distributed to the participants at the final ceremony of the intensive program in order to collect the data from a large number of the participants at a time. The data showed significant evidence to support the hypothetical model. The results confirmed through structural equation modeling analysis are as follows: First, four external variables such as subjective norm, content reliability, interactivity, and self-regulation significantly affected perceived ease of use. Second, subjective norm, content reliability, self-regulation, perceived ease of use significantly affected perceived usefulness. Third, perceived usefulness and perceived ease of use significantly affected attitude toward MALL. Fourth, attitude toward MALL and perceived usefulness significantly affected behavioral intention to use MALL. These results implied that the integrated framework from TAM and MALL could be useful when adopting MALL environment to university students or adult English learners. Key constructs except interactivity showed significant relationships with one another and had direct and indirect impacts on MALL user’s acceptance behavior. Therefore, the constructs and validated metrics is valuable for language researchers and educators who are interested in MALL.Keywords: blended MALL, learner factors/variables, mobile-assisted language learning, MALL, technology acceptance model, TAM, theoretical framework
Procedia PDF Downloads 2371492 A Bayesian Approach for Health Workforce Planning in Portugal
Authors: Diana F. Lopes, Jorge Simoes, José Martins, Eduardo Castro
Abstract:
Health professionals are the keystone of any health system, by delivering health services to the population. Given the time and cost involved in training new health professionals, the planning process of the health workforce is particularly important as it ensures a proper balance between the supply and demand of these professionals and it plays a central role on the Health 2020 policy. In the past 40 years, the planning of the health workforce in Portugal has been conducted in a reactive way lacking a prospective vision based on an integrated, comprehensive and valid analysis. This situation may compromise not only the productivity and the overall socio-economic development but the quality of the healthcare services delivered to patients. This is even more critical given the expected shortage of the health workforce in the future. Furthermore, Portugal is facing an aging context of some professional classes (physicians and nurses). In 2015, 54% of physicians in Portugal were over 50 years old, and 30% of all members were over 60 years old. This phenomenon associated to an increasing emigration of young health professionals and a change in the citizens’ illness profiles and expectations must be considered when planning resources in healthcare. The perspective of sudden retirement of large groups of professionals in a short time is also a major problem to address. Another challenge to embrace is the health workforce imbalances, in which Portugal has one of the lowest nurse to physician ratio, 1.5, below the European Region and the OECD averages (2.2 and 2.8, respectively). Within the scope of the HEALTH 2040 project – which aims to estimate the ‘Future needs of human health resources in Portugal till 2040’ – the present study intends to get a comprehensive dynamic approach of the problem, by (i) estimating the needs of physicians and nurses in Portugal, by specialties and by quinquenium till 2040; (ii) identifying the training needs of physicians and nurses, in medium and long term, till 2040, and (iii) estimating the number of students that must be admitted into medicine and nursing training systems, each year, considering the different categories of specialties. The development of such approach is significantly more critical in the context of limited budget resources and changing health care needs. In this context, this study presents the drivers of the healthcare needs’ evolution (such as the demographic and technological evolution, the future expectations of the users of the health systems) and it proposes a Bayesian methodology, combining the best available data with experts opinion, to model such evolution. Preliminary results considering different plausible scenarios are presented. The proposed methodology will be integrated in a user-friendly decision support system so it can be used by politicians, with the potential to measure the impact of health policies, both at the regional and the national level.Keywords: bayesian estimation, health economics, health workforce planning, human health resources planning
Procedia PDF Downloads 2511491 Fostering Diversity, Equity, and Inclusion: Case of Higher Education Institutions in Kazakhstan
Authors: Gainiya Tazhina
Abstract:
Higher education systems of many countries have increased diversity and ensured equal rights and opportunities for inclusive students in the last decades. Issues of diversity-equity-inclusion (DEI) in Kazakhstani higher education began to be considered in legislation in 2021-2023. The adoption of the Road Map of the Ministry of Education and Science for universities’ inclusivity indicated strategies for change. The paper traces how this government initiative is being implemented in universities across the country. Content analysis of legislative documents, media publications, surveys of students, staff and interviews with leaders have demonstrated the inconsistency of these strategic decisions. Thus, the Road Map required that by 2023 conditions for promoting and ensuring inclusive education and barrier-free environments should be created in 60% -100% of Kazakhstani universities, including spaces inside academic buildings and dormitories in a short period of time. (March 2023-August 2025). Educational programs and curricula have not been adapted to the needs of students with special education needs (SEN); teachers do not have the skills and methods to work with students with SEN, students from minority groups, and international students. 60% of universities have not created a barrier-free environment on campuses due to the high cost of elevators, tactile tiles and assistive devices. Only 1% of school-disabled graduates enter universities due to the unwillingness of universities to educate people with disabilities. At the same time, universities do not adapt their educational programs and services to the needs of inclusive students; their needs are not identified; they study under the same conditions as regular students. Accordingly, teaching staff does not have the knowledge and skills to teach inclusive students; university lecturers misunderstand or oversimplify the social phenomena of ‘inclusion’ and ‘diversity’. The situation is more acute with the creation of a barrier-free architectural environment on university campuses. Recent reports indicate that these reforms have not been implemented to date, proven controversial in practice due to the inconsistency of national research on inclusion in higher education. Widely announced reforms have not produced the expected results leading to distortions at the local level. Inconsistent policies, contradictory legislative acts without expertise of needs and developing specific implementation criteria, without training specialists and indicators for achieving reforms are doomed to failure and mistrust of society. Based on the results of this research, recommendations have been developed: (1) to overcome inconsistencies in legislation regarding DEI in higher education; (2) to encourage initiatives in universities' inclusive environments; (3) to develop projects that will promote public awareness of DEI.Keywords: diversity-equity-inclusion, Kazakhstani universities, reforms, legislation, accessibility
Procedia PDF Downloads 101490 Revolutionizing Healthcare Communication: The Transformative Role of Natural Language Processing and Artificial Intelligence
Authors: Halimat M. Ajose-Adeogun, Zaynab A. Bello
Abstract:
Artificial Intelligence (AI) and Natural Language Processing (NLP) have transformed computer language comprehension, allowing computers to comprehend spoken and written language with human-like cognition. NLP, a multidisciplinary area that combines rule-based linguistics, machine learning, and deep learning, enables computers to analyze and comprehend human language. NLP applications in medicine range from tackling issues in electronic health records (EHR) and psychiatry to improving diagnostic precision in orthopedic surgery and optimizing clinical procedures with novel technologies like chatbots. The technology shows promise in a variety of medical sectors, including quicker access to medical records, faster decision-making for healthcare personnel, diagnosing dysplasia in Barrett's esophagus, boosting radiology report quality, and so on. However, successful adoption requires training for healthcare workers, fostering a deep understanding of NLP components, and highlighting the significance of validation before actual application. Despite prevailing challenges, continuous multidisciplinary research and collaboration are critical for overcoming restrictions and paving the way for the revolutionary integration of NLP into medical practice. This integration has the potential to improve patient care, research outcomes, and administrative efficiency. The research methodology includes using NLP techniques for Sentiment Analysis and Emotion Recognition, such as evaluating text or audio data to determine the sentiment and emotional nuances communicated by users, which is essential for designing a responsive and sympathetic chatbot. Furthermore, the project includes the adoption of a Personalized Intervention strategy, in which chatbots are designed to personalize responses by merging NLP algorithms with specific user profiles, treatment history, and emotional states. The synergy between NLP and personalized medicine principles is critical for tailoring chatbot interactions to each user's demands and conditions, hence increasing the efficacy of mental health care. A detailed survey corroborated this synergy, revealing a remarkable 20% increase in patient satisfaction levels and a 30% reduction in workloads for healthcare practitioners. The poll, which focused on health outcomes and was administered to both patients and healthcare professionals, highlights the improved efficiency and favorable influence on the broader healthcare ecosystem.Keywords: natural language processing, artificial intelligence, healthcare communication, electronic health records, patient care
Procedia PDF Downloads 741489 The Effect of Mindfulness Meditation on Pain, Sleep Quality, and Self-Esteem in Patients Receiving Hemodialysis in Jordan
Authors: Hossam N. Alhawatmeh, Areen I. Albustanji
Abstract:
Hemodialysis negatively affects physical and psychological health. Pain, poor sleep quality, and low self-esteem are highly prevalent among patients with end-stage renal disease (ESRD) who receive hemodialysis, significantly increasing mortality and morbidity of those patients. Mind-body interventions (MBI), such as mindfulness meditation, have been recently gaining popularity that improved pain, sleep quality, and self-esteem in different populations. However, to our best knowledge, its effects on these health problems in patients receiving hemodialysis have not been studied in Jordan. Thus, the purpose of the study was to examine the effect of mindfulness meditation on pain, sleep quality, and self-esteem in patients with ESR receiving hemodialysis in Jordan. An experimental repeated-measures, randomized, parallel control design was conducted on (n =60) end-stage renal disease patients undergoing hemodialysis between March and June 2023 in the dialysis center at a public hospital in Jordan. Participants were randomly assigned to the experimental (n =30) and control groups (n =30) using a simple random assignment method. The experimental group practiced mindfulness meditation for 30 minutes three times per week for five weeks during their hemodialysis treatments. The control group's patients continued to receive hemodialysis treatment as usual for five weeks during hemodialysis sessions. The study variables for both groups were measured at baseline (Time 0), two weeks after intervention (Time 1), and at the end of intervention (Time 3). The numerical rating scale (NRS), the Rosenberg Self-Esteem Scale (RSES-M), and the Pittsburgh Sleep Quality Index (PSQI) were used to measure pain, self-esteem, and sleep quality, respectively. SPSS version 25 was used to analyze the study data. The sample was described by frequency, mean, and standard deviation as an appropriate. The repeated measures analysis of variance (ANOVA) tests were run to test the study hypotheses. The results of repeated measures ANOVA (within-subject) revealed that mindfulness meditation significantly decrease pain by the end of the intervention in the experimental group. Additionally, mindfulness meditation improved sleep quality and self-esteem in the experimental group, and these improvements occurred significantly after two weeks of the intervention and at the end of the intervention. The results of repeated measures ANOVA (within and between-subject) revealed that the experimental group, compared to the control group, experienced lower levels of pain and higher levels of sleep quality and self-esteem over time. In conclusion, the results provided substantial evidence supporting the positive impacts of mindfulness meditation on pain, sleep quality, and self-esteem in patients with ESRD undergoing hemodialysis. These results highlight the potential of mindfulness meditation as an adjunctive therapy in the comprehensive care of this patient population. Incorporating mindfulness meditation into the treatment plan for patients receiving hemodialysis may contribute to improved well-being and overall quality of life.Keywords: hemodialysis, pain, sleep quality, self-esteem, mindfulness
Procedia PDF Downloads 861488 Pregnancy Outcome in Women with HIV Infection from a Tertiary Care Centre of India
Authors: Kavita Khoiwal, Vatsla Dadhwal, K. Aparna Sharma, Dipika Deka, Plabani Sarkar
Abstract:
Introduction: About 2.4 million (1.93 - 3.04 million) people are living with HIV/AIDS in India. Of all HIV infections, 39% (9,30,000) are among women. 5.4% of infections are from mother to child transmission (MTCT), 25,000 infected children are born every year. Besides the risk of mother to child transmission of HIV, these women are at risk of the higher adverse pregnancy outcome. The objectives of the study were to compare the obstetric and neonatal outcome in women who are HIV positive with low-risk HIV negative women and effect of antiretroviral drugs on preterm birth and IUGR. Materials and Methods: This is a retrospective case record analysis of 212 HIV-positive women delivering between 2002 to 2015, in a tertiary health care centre which was compared with 238 HIV-negative controls. Women who underwent medical termination of pregnancy and abortion were excluded from the study. Obstetric outcome analyzed were pregnancy induced hypertension, HIV positive intrauterine growth restriction, preterm birth, anemia, gestational diabetes and intrahepatic cholestasis of pregnancy. Neonatal outcome analysed were birth weight, apgar score, NICU admission and perinatal transmission.HIV-positiveOut of 212 women, 204 received antiretroviral therapy (ART) to prevent MTCT, 27 women received single dose nevirapine (sdNVP) or sdNVP tailed with 7 days of zidovudine and lamivudine (ZDV + 3TC), 15 received ZDV, 82 women received duovir and 80 women received triple drug therapy depending upon the time period of presentation. Results: Mean age of 212 HIV positive women was 25.72+3.6 years, 101 women (47.6 %) were primigravida. HIV positive status was diagnosed during pregnancy in 200 women while 12 women were diagnosed prior to conception. Among 212 HIV positive women, 20 (9.4 %) women had preterm delivery (< 37 weeks), 194 women (91.5 %) delivered by cesarean section and 18 women (8.5 %) delivered vaginally. 178 neonates (83.9 %) received exclusive top feeding and 34 neonates (16.03 %) received exclusive breast feeding. When compared to low risk HIV negative women (n=238), HIV positive women were more likely to deliver preterm (OR 1.27), have anemia (OR 1.39) and intrauterine growth restriction (OR 2.07). Incidence of pregnancy induced hypertension, diabetes mellitus and ICP was not increased. Mean birth weight was significantly lower in HIV positive women (2593.60+499 gm) when compared to HIV negative women (2919+459 gm). Complete follow up is available for 148 neonates till date, rest are under evaluation. Out of these 7 neonates found to have HIV positive status. Risk of preterm birth (P value = 0.039) and IUGR (P value = 0.739) was higher in HIV positive women who did not receive any ART during pregnancy than women who received ART. Conclusion: HIV positive pregnant women are at increased risk of adverse pregnancy outcome. Multidisciplinary team approach and use of highly active antiretroviral therapy can optimize the maternal and perinatal outcome.Keywords: antiretroviral therapy, HIV infection, IUGR, preterm birth
Procedia PDF Downloads 2591487 Mapping and Mitigation Strategy for Flash Flood Hazards: A Case Study of Bishoftu City
Authors: Berhanu Keno Terfa
Abstract:
Flash floods are among the most dangerous natural disasters that pose a significant threat to human existence. They occur frequently and can cause extensive damage to homes, infrastructure, and ecosystems while also claiming lives. Although flash floods can happen anywhere in the world, their impact is particularly severe in developing countries due to limited financial resources, inadequate drainage systems, substandard housing options, lack of early warning systems, and insufficient preparedness. To address these challenges, a comprehensive study has been undertaken to analyze and map flood inundation using Geographic Information System (GIS) techniques by considering various factors that contribute to flash flood resilience and developing effective mitigation strategies. Key factors considered in the analysis include slope, drainage density, elevation, Curve Number, rainfall patterns, land-use/cover classes, and soil data. These variables were computed using ArcGIS software platforms, and data from the Sentinel-2 satellite image (with a 10-meter resolution) were utilized for land-use/cover classification. Additionally, slope, elevation, and drainage density data were generated from the 12.5-meter resolution of the ALOS Palsar DEM, while other relevant data were obtained from the Ethiopian Meteorological Institute. By integrating and regularizing the collected data through GIS and employing the analytic hierarchy process (AHP) technique, the study successfully delineated flash flood hazard zones (FFHs) and generated a suitable land map for urban agriculture. The FFH model identified four levels of risk in Bishoftu City: very high (2106.4 ha), high (10464.4 ha), moderate (1444.44 ha), and low (0.52 ha), accounting for 15.02%, 74.7%, 10.1%, and 0.004% of the total area, respectively. The results underscore the vulnerability of many residential areas in Bishoftu City, particularly the central areas that have been previously developed. Accurate spatial representation of flood-prone areas and potential agricultural zones is crucial for designing effective flood mitigation and agricultural production plans. The findings of this study emphasize the importance of flood risk mapping in raising public awareness, demonstrating vulnerability, strengthening financial resilience, protecting the environment, and informing policy decisions. Given the susceptibility of Bishoftu City to flash floods, it is recommended that the municipality prioritize urban agriculture adaptation, proper settlement planning, and drainage network design.Keywords: remote sensing, flush flood hazards, Bishoftu, GIS.
Procedia PDF Downloads 331486 Secure Optimized Ingress Filtering in Future Internet Communication
Authors: Bander Alzahrani, Mohammed Alreshoodi
Abstract:
Information-centric networking (ICN) using architectures such as the Publish-Subscribe Internet Technology (PURSUIT) has been proposed as a new networking model that aims at replacing the current used end-centric networking model of the Internet. This emerged model focuses on what is being exchanged rather than which network entities are exchanging information, which gives the control plane functions such as routing and host location the ability to be specified according to the content items. The forwarding plane of the PURSUIT ICN architecture uses a simple and light mechanism based on Bloom filter technologies to forward the packets. Although this forwarding scheme solve many problems of the today’s Internet such as the growth of the routing table and the scalability issues, it is vulnerable to brute force attacks which are starting point to distributed- denial-of-service (DDoS) attacks. In this work, we design and analyze a novel source-routing and information delivery technique that keeps the simplicity of using Bloom filter-based forwarding while being able to deter different attacks such as denial of service attacks at the ingress of the network. To achieve this, special forwarding nodes called Edge-FW are directly attached to end user nodes and used to perform a security test for malicious injected random packets at the ingress of the path to prevent any possible attack brute force attacks at early stage. In this technique, a core entity of the PURSUIT ICN architecture called topology manager, that is responsible for finding shortest path and creating a forwarding identifiers (FId), uses a cryptographically secure hash function to create a 64-bit hash, h, over the formed FId for authentication purpose to be included in the packet. Our proposal restricts the attacker from injecting packets carrying random FIds with a high amount of filling factor ρ, by optimizing and reducing the maximum allowed filling factor ρm in the network. We optimize the FId to the minimum possible filling factor where ρ ≤ ρm, while it supports longer delivery trees, so the network scalability is not affected by the chosen ρm. With this scheme, the filling factor of any legitimate FId never exceeds the ρm while the filling factor of illegitimate FIds cannot exceed the chosen small value of ρm. Therefore, injecting a packet containing an FId with a large value of filling factor, to achieve higher attack probability, is not possible anymore. The preliminary analysis of this proposal indicates that with the designed scheme, the forwarding function can detect and prevent malicious activities such DDoS attacks at early stage and with very high probability.Keywords: forwarding identifier, filling factor, information centric network, topology manager
Procedia PDF Downloads 1531485 Bedouin of Silicon Wadi: A Case Study Analysis of the Multi-Level Perspectives and Factors Affecting Bedouin Entrepreneurialism as Obstacles to Entry into the Israeli High-Tech Industry
Authors: Frazer G. Thompson
Abstract:
Israel is a nation of cultural and historical diversity, yet the success factors for a modern Bedouin-Arab high-tech entrepreneur seem to be different from those of other Jewish-Israeli citizens. The purpose of this descriptive narrative case study is to explore how an Arab-Israeli all Negev-Bedouin technology company has succeeded in the Israeli high-tech industry by utilizing technology and engineering career opportunities available to Bedouin youth for ‘Sadel Tech,’ at Be’er-Sheva, the Negev, Israel. Methods: The strategy of inquiry seeks to explore real-life contextual understandings, multi-level perspectives, and the cultural influences of personal, community, educational, and entrepreneurial factors. The research methodology includes in-depth one-on-one interviews, focus group sessions, and overt observation to explore the meaning and understanding of the constructs toward determining the effect all or a few of the elements may have on the overall success factors of the company. Results: Study results indicate that the state-run educational system in Israel fails to adequately integrate important aspects of Bedouin culture into the learning environment. However, Bedouin entrepreneurs are finding ways to compensate for these inadequacies by utilizing non-traditional methods of teaching, learning, and doing business. Government incentives for Bedouin start-ups are also recognized as contributors. Employees of Sadel live and work in the Negev, the Gaza Strip, and the West Bank, further informing the study that the traditions of tribal etiquette continue to contribute to modern Bedouin-Arab business culture. Conclusion: Bedouin's business success in Israel is a multi-dimensional concept. While cultural acumen plays a prominent and unique role for both Arab-Israelis and Jewish-Israelis in economic and entrepreneurial pursuits, the marginalization of the Bedouin continues to contribute to the lack of educational and professional opportunities for Bedouin in Israel. Although recognized as important at the government level, programs necessary to implement the infrastructure required to support Bedouin entrepreneurship in Israel remain infantile. The Israeli Government is providing opportunities through grants and other incentives for Bedouin entrepreneurial start-ups, indicating that Israel has recognized the impact of this growing demographic. However, although many Bedouin graduates from University each year with advanced degrees, opportunities for Bedouin within the Israeli high-tech sector remain scarce.Keywords: Bedouin education, Bedouin entrepreneur, economic anthropology, ethnic business opportunities, Israeli tech, Silicon Wadi
Procedia PDF Downloads 1201484 The Politics of Fantasy Meet Precarity of Place
Authors: Claudia Popescu, Adriana Mihaela Soaita
Abstract:
Within the EU accession process, Romania, as well as other CEE countries, have embarked on the post-1990 urbanization wave aiming to reduce the gaps between ‘older’ and ‘new’ EU member states. While post-socialist urban transitions have been extensively scrutinized, little is known about the developing trajectories of these new towns across the CEE region. To start addressing this knowledge gap, we wish to bring to the fore one of the most humble expressions of urbanism, that of the small, new towns of Romania. Despite rural-to-urban reclassification, urbanization levels have remained persistently low over the last three decades. In this context, it is timely and legitimate to ask about the prospects of new towns for a ‘successful’ socioeconomic performance within the urban network and avoidance of precarity and marginalization and adequate measure of place performance within the urban/settlement network and understanding the drivers that trigger towns’ socioeconomic performances. To answer these, we create a socioeconomic index of the place in order to compare the profile of the 60 new towns with large cities, old small towns and rural. We conceive ‘successful’ and ‘precarious’ performance in terms of a locality’s index value being above or below all small towns’ index average. Second, we performed logistic regression to interrogate the relevance of some key structural factors to the new towns’ socioeconomic performance (i.e. population size, urban history, regional location, connectivity and political determination of their local governments). Related to the first research question, our findings highlight the precarity of place as a long-standing condition of living and working in the new towns of Romania, particularly evident through our cross-comparative analysis across key category along the rural-urban continuum. We have substantiated the socioeconomic condition of precarity in rural places, with the new towns still maintaining features of ‘rurality’ rather than ‘urbanity’ - except a few successful satellites of economically striving large cities, particularly the country capital of Bucharest, which benefited from spillover effects. Related to our second research question, we found that the new towns of Romania have significantly higher odds of being characterized by precarity as a socioeconomic condition than all other small towns and urban places, but less so compared to the even more marginalized rural areas. Many new towns contain resource-dependent rural communities with a poor response to the context of change. Therefore, issues pertaining to local capacity building to adapt to the new urban environment should be addressed by the spatial planning policy. Our approach allowed us to bring to the fore the idea of precarity as a condition of whole localities. Thinking of precarity of place is important as it brings the whole institutional and political apparatus of spatial planning, urban and regional, into conversation with other causative or substantive axes of precarity developed in the literature. We recommend future research on the new towns in Romania and elsewhere.Keywords: politics of fantasy, precarity of place, urbanization, Romania
Procedia PDF Downloads 131483 The Gut Microbiome in Cirrhosis and Hepatocellular Carcinoma: Characterization of Disease-Related Microbial Signature and the Possible Impact of Life Style and Nutrition
Authors: Lena Lapidot, Amir Amnon, Rita Nosenko, Veitsman Ella, Cohen-Ezra Oranit, Davidov Yana, Segev Shlomo, Koren Omry, Safran Michal, Ben-Ari Ziv
Abstract:
Introduction: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer related mortality worldwide. Liver Cirrhosis is the main predisposing risk factor for the development of HCC. The factor(s) influencing disease progression from Cirrhosis to HCC remain unknown. Gut microbiota has recently emerged as a major player in different liver diseases, however its association with HCC is still a mystery. Moreover, there might be an important association between the gut microbiota, nutrition, life style and the progression of Cirrhosis and HCC. The aim of our study was to characterize the gut microbial signature in association with life style and nutrition of patients with Cirrhosis, HCC-Cirrhosis and healthy controls. Design: Stool samples were collected from 95 individuals (30 patients with HCC, 38 patients with Cirrhosis and 27 age, gender and BMI-matched healthy volunteers). All participants answered lifestyle and Food Frequency Questionnaires. 16S rRNA sequencing of fecal DNA was performed (MiSeq Illumina). Results: There was a significant decrease in alpha diversity in patients with Cirrhosis (qvalue=0.033) and in patients with HCC-Cirrhosis (qvalue=0.032) compared to healthy controls. The microbiota of patients with HCC-cirrhosis compared to patients with Cirrhosis, was characterized by a significant overrepresentation of Clostridium (pvalue=0.024) and CF231 (pvalue=0.010) and lower expression of Alphaproteobacteria (pvalue=0.039) and Verrucomicrobia (pvalue=0.036) in several taxonomic levels: Verrucomicrobiae, Verrucomicrobiales, Verrucomicrobiaceae and the genus Akkermansia (pvalue=0.039). Furthermore, we performed an analysis of predicted metabolic pathways (Kegg level 2) that resulted in a significant decrease in the diversity of metabolic pathways in patients with HCC-Cirrhosis (qvalue=0.015) compared to controls, one of which was amino acid metabolism. Furthermore, investigating the life style and nutrition habits of patients with HCC-Cirrhosis, we found significant correlations between intake of artificial sweeteners and Verrucomicrobia (qvalue=0.12), High sugar intake and Synergistetes (qvalue=0.021) and High BMI and the pathogen Campylobacter (qvalue=0.066). Furthermore, overweight in patients with HCC-Cirrhosis modified bacterial diversity (qvalue=0.023) and composition (qvalue=0.033). Conclusions: To the best of the our knowledge, we present the first report of the gut microbial composition in patients with HCC-Cirrhosis, compared with Cirrhotic patients and healthy controls. We have demonstrated in our study that there are significant differences in the gut microbiome of patients with HCC-cirrhosis compared to Cirrhotic patients and healthy controls. Our findings are even more pronounced because the significantly increased bacteria Clostridium and CF231 in HCC-Cirrhosis weren't influenced by diet and lifestyle, implying this change is due to the development of HCC. Further studies are needed to confirm these findings and assess causality.Keywords: Cirrhosis, Hepatocellular carcinoma, life style, liver disease, microbiome, nutrition
Procedia PDF Downloads 1271482 Development of an Automatic Computational Machine Learning Pipeline to Process Confocal Fluorescence Images for Virtual Cell Generation
Authors: Miguel Contreras, David Long, Will Bachman
Abstract:
Background: Microscopy plays a central role in cell and developmental biology. In particular, fluorescence microscopy can be used to visualize specific cellular components and subsequently quantify their morphology through development of virtual-cell models for study of effects of mechanical forces on cells. However, there are challenges with these imaging experiments, which can make it difficult to quantify cell morphology: inconsistent results, time-consuming and potentially costly protocols, and limitation on number of labels due to spectral overlap. To address these challenges, the objective of this project is to develop an automatic computational machine learning pipeline to predict cellular components morphology for virtual-cell generation based on fluorescence cell membrane confocal z-stacks. Methods: Registered confocal z-stacks of nuclei and cell membrane of endothelial cells, consisting of 20 images each, were obtained from fluorescence confocal microscopy and normalized through software pipeline for each image to have a mean pixel intensity value of 0.5. An open source machine learning algorithm, originally developed to predict fluorescence labels on unlabeled transmitted light microscopy cell images, was trained using this set of normalized z-stacks on a single CPU machine. Through transfer learning, the algorithm used knowledge acquired from its previous training sessions to learn the new task. Once trained, the algorithm was used to predict morphology of nuclei using normalized cell membrane fluorescence images as input. Predictions were compared to the ground truth fluorescence nuclei images. Results: After one week of training, using one cell membrane z-stack (20 images) and corresponding nuclei label, results showed qualitatively good predictions on training set. The algorithm was able to accurately predict nuclei locations as well as shape when fed only fluorescence membrane images. Similar training sessions with improved membrane image quality, including clear lining and shape of the membrane, clearly showing the boundaries of each cell, proportionally improved nuclei predictions, reducing errors relative to ground truth. Discussion: These results show the potential of pre-trained machine learning algorithms to predict cell morphology using relatively small amounts of data and training time, eliminating the need of using multiple labels in immunofluorescence experiments. With further training, the algorithm is expected to predict different labels (e.g., focal-adhesion sites, cytoskeleton), which can be added to the automatic machine learning pipeline for direct input into Principal Component Analysis (PCA) for generation of virtual-cell mechanical models.Keywords: cell morphology prediction, computational machine learning, fluorescence microscopy, virtual-cell models
Procedia PDF Downloads 2031481 Convective Boiling of CO₂/R744 in Macro and Micro-Channels
Authors: Adonis Menezes, J. C. Passos
Abstract:
The current panorama of technology in heat transfer and the scarcity of information about the convective boiling of CO₂ and hydrocarbon in small diameter channels motivated the development of this work. Among non-halogenated refrigerants, CO₂/ R744 has distinct thermodynamic properties compared to other fluids. The R744 presents significant differences in operating pressures and temperatures, operating at higher values compared to other refrigerants, and this represents a challenge for the design of new evaporators, as the original systems must normally be resized to meet the specific characteristics of the R744, which creates the need for a new design and optimization criteria. To carry out the convective boiling tests of CO₂, an experimental apparatus capable of storing (m= 10kg) of saturated CO₂ at (T = -30 ° C) in an accumulator tank was used, later this fluid was pumped using a positive displacement pump with three pistons, and the outlet pressure was controlled and could reach up to (P = 110bar). This high-pressure saturated fluid passed through a Coriolis type flow meter, and the mass velocities varied between (G = 20 kg/m².s) up to (G = 1000 kg/m².s). After that, the fluid was sent to the first test section of circular cross-section in diameter (D = 4.57mm), where the inlet and outlet temperatures and pressures, were controlled and the heating was promoted by the Joule effect using a source of direct current with a maximum heat flow of (q = 100 kW/m²). The second test section used a cross-section with multi-channels (seven parallel channels) with a square cross-section of (D = 2mm) each; this second test section has also control of temperature and pressure at the inlet and outlet as well as for heating a direct current source was used, with a maximum heat flow of (q = 20 kW/m²). The fluid in a biphasic situation was directed to a parallel plate heat exchanger so that it returns to the liquid state, thus being able to return to the accumulator tank, continuing the cycle. The multi-channel test section has a viewing section; a high-speed CMOS camera was used for image acquisition, where it was possible to view the flow patterns. The experiments carried out and presented in this report were conducted in a rigorous manner, enabling the development of a database on the convective boiling of the R744 in macro and micro channels. The analysis prioritized the processes from the beginning of the convective boiling until the drying of the wall in a subcritical regime. The R744 resurfaces as an excellent alternative to chlorofluorocarbon refrigerants due to its negligible ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) rates, among other advantages. The results found in the experimental tests were very promising for the use of CO₂ in micro-channels in convective boiling and served as a basis for determining the flow pattern map and correlation for determining the heat transfer coefficient in the convective boiling of CO₂.Keywords: convective boiling, CO₂/R744, macro-channels, micro-channels
Procedia PDF Downloads 1411480 Reinventing Smart Tourism via Use of Smart Gamified and Gaming Applications in Greece
Authors: Sofia Maria Poulimenou, Ioannis Deliyannis, Elisavet Filippidou, Stamatella Laboura
Abstract:
Smart technologies are being actively used to improve the experience of travel and promote or demote a destination’s reputation via a wide variety of social media applications and platforms. This paper conceptualises the design and deployment of smart management apps to promote culture, sustainability and accessibility within two destinations in Greece that represent the extremes of visiting scale. One is the densely visited Corfu, which is a UNESCO’s heritage site. The problems caused by the lack of organisation of the visiting experience and infrastructures affect all parties interacting within the site: visitors, citizens, public and private sector. Second is Kilkis, a low tourism destination with high seasonality and mostly inbound tourism. Here the issue faced is that traditional approaches to inform and motivate locals and visitors to explore and taste of the culture have not flourished. The problem is apprehended via the design and development of two systems named “Hologrammatic Corfu” for Corfu old town and “BRENDA” for the area of Kilkis. Although each system is designed independently, featuring different solutions to the problems, both approaches have been designed by the same team and a novel gaming and gamification methodology. The “Hologramatic Corfu” application has been designed, for the exploration of the site covering user requirments before, during and after the trip, with the use of transmedia content such as photos, 360-degree videos, augmented reality and hologrammatic videos. Also, a statistical analysis of travellers’ visits to specific points of interest is actively utilized enabling visitors to dynamically re-rooted during their visit, safeguarding sustainability and accessibility and inclusivity along the entire tourism cycle. “BRENDA” is designed specifically to promote gastronomic and historical tourism. This serious game implements and combines gaming and gamification elements in order to connect local businesses with cultural points of interest. As the environment of the project has a strong touristic orientation, “BRENDA” supports food-related gamified processes and historical games involving active participation of both local communities (content providers) and visitors (players) which are more likely to be successfully performed in the informal environment of travelling and promote sustainable tourism experiences. Finally, the paper presents the ability to re-use existing gaming components within new areas of interest via minimal adaptation and the use of transmedia aspects that enables destinations to be rebranded into smart destinations.Keywords: smart tourism, gamification, user experience, transmedia content
Procedia PDF Downloads 1731479 Experimental Investigation on Tensile Durability of Glass Fiber Reinforced Polymer (GFRP) Rebar Embedded in High Performance Concrete
Authors: Yuan Yue, Wen-Wei Wang
Abstract:
The objective of this research is to comprehensively evaluate the impact of alkaline environments on the durability of Glass Fiber Reinforced Polymer (GFRP) reinforcements in concrete structures and further explore their potential value within the construction industry. Specifically, we investigate the effects of two widely used high-performance concrete (HPC) materials on the durability of GFRP bars when embedded within them under varying temperature conditions. A total of 279 GFRP bar specimens were manufactured for microcosmic and mechanical performance tests. Among them, 270 specimens were used to test the residual tensile strength after 120 days of immersion, while 9 specimens were utilized for microscopic testing to analyze degradation damage. SEM techniques were employed to examine the microstructure of GFRP and cover concrete. Unidirectional tensile strength experiments were conducted to determine the remaining tensile strength after corrosion. The experimental variables consisted of four types of concrete (engineering cementitious composite (ECC), ultra-high-performance concrete (UHPC), and two types of ordinary concrete with different compressive strengths) as well as three acceleration temperatures (20, 40, and 60℃). The experimental results demonstrate that high-performance concrete (HPC) offers superior protection for GFRP bars compared to ordinary concrete. Two types of HPC enhance durability through different mechanisms: one by reducing the pH of the concrete pore fluid and the other by decreasing permeability. For instance, ECC improves embedded GFRP's durability by lowering the pH of the pore fluid. After 120 days of immersion at 60°C under accelerated conditions, ECC (pH=11.5) retained 68.99% of its strength, while PC1 (pH=13.5) retained 54.88%. On the other hand, UHPC enhances FRP steel's durability by increasing porosity and compactness in its protective layer to reinforce FRP reinforcement's longevity. Due to fillers present in UHPC, it typically exhibits lower porosity, higher densities, and greater resistance to permeation compared to PC2 with similar pore fluid pH levels, resulting in varying degrees of durability for GFRP bars embedded in UHPC and PC2 after 120 days of immersion at a temperature of 60°C - with residual strengths being 66.32% and 60.89%, respectively. Furthermore, SEM analysis revealed no noticeable evidence indicating fiber deterioration in any examined specimens, thus suggesting that uneven stress distribution resulting from interface segregation and matrix damage emerges as a primary causative factor for tensile strength reduction in GFRP rather than fiber corrosion. Moreover, long-term prediction models were utilized to calculate residual strength values over time for reinforcement embedded in HPC under high temperature and high humidity conditions - demonstrating that approximately 75% of its initial strength was retained by reinforcement embedded in HPC after 100 years of service.Keywords: GFRP bars, HPC, degeneration, durability, residual tensile strength.
Procedia PDF Downloads 551478 Light, Restorativeness and Performance in the Workplace: A Pilot Study
Authors: D. Scarpanti, M. Brondino, M. Pasini
Abstract:
Background: the present study explores the role of light and restorativeness on work. According with the Attention Restoration Theory (ART) and a Model of Work Environment, the main idea is that some features of environment, i.e., lighting, influences the direct attention, and so, the performance. Restorativeness refers to the presence/absence level of all the characteristics of physical environment that help to regenerate direct attention. Specifically, lighting can affect level of fascination and attention in one hand; and in other hand promotes several biological functions via pineal gland. Different reviews on this topic show controversial results. In order to bring light on this topic, the hypotheses of this study are that lighting can affect the construct of restorativeness and, in the second time, the restorativeness can affect the performance. Method: the participants are 30 workers of a mechatronic company in the North Italy. Every subject answered to a questionnaire valuing their subjective perceptions of environment in a different way: some objective features of environment, like lighting, temperature and air quality; some subjective perceptions of this environment; finally, the participants answered about their perceived performance. The main attention is on the features of light and his components: visual comfort, general preferences and pleasantness; and the dimensions of the construct of restorativeness; fascination, coherence and being away. The construct of performance per se is conceptualized in three level: individual, team membership and organizational membership; and in three different components: proficiency, adaptability, and proactivity, for a total of 9 subcomponents. Findings: path analysis showed that some characteristics of lighting respectively affected the dimension of fascination; and, as expected, the dimension of fascination affected work performance. Conclusions: The present study is a first pilot step of a wide research. These first results can be summarized with the statement that lighting and restorativeness contribute to explain work performance variability: in details perceptions of visual comfort, satisfaction and pleasantness, and fascination respectively. Results related to fascination are particularly interesting because fascination is conceptualized as the opposite of the construct of direct attention. The main idea is, in order to regenerate attentional capacity, it’s necessary to provide a lacking of attention (fascination). The sample size did not permit to test simultaneously the role of the perceived characteristics of light to see how they differently contribute to predict fascination of the work environment. However, the results highlighted the important role that light could have in predicting restorativeness dimensions and probably with a larger sample we could find larger effects also on work performance. Furthermore, longitudinal data will contribute to better analyze the causal model along time. Applicative implications: the present pilot study highlights the relevant role of lighting and perceived restorativeness in the work environment and the importance to focus attention on light features and the restorative characteristics in the design of work environments.Keywords: lighting, performance, restorativeness, workplace
Procedia PDF Downloads 1541477 Optimizing the Pair Carbon Xerogels-Electrolyte for High Performance Supercapacitors
Authors: Boriana Karamanova, Svetlana Veleva, Luybomir Soserov, Ana Arenillas, Francesco Lufrano, Antonia Stoyanova
Abstract:
Supercapacitors have received a lot of research attention and are promising energy storage devices due to their high power and long cycle life. In order to developed an advanced device with significant capacity for storing charge and cheap carbon materials, efforts must focus not only on improving synthesis by controlling the morphology and pore size but also on improving electrode-electrolyte compatibility of the resulting systems. The present study examines the relationship between the surface chemistry of two activated carbon xerogels, the electrolyte type, and the electrochemical properties of supercapacitors. Activated carbon xerogels were prepared by varying the initial pH of the resorcinol-formaldehyde aqueous solution. The materials produced are physicochemical characterized by DTA/TGA, porous characterization, and SEM analysis. The carbon xerogel based electrodes were prepared by spreading over glass plate a slurry containing the carbon gel, graphite, and poly vinylidene difluoride (PVDF) binder. The layer formed was dried consecutively at different temperatures and then detached by water. After, the layer was dried again to improve its mechanical stability. The developed electrode materials and the Aquivion® E87-05S membrane (Solvay Specialty Polymers), socked in Na2SO4 as a polymer electrolyte, were used to assembly the solid-state supercapacitor. Symmetric supercapacitor cells composed by same electrodes and 1 M KOH electrolytes are also assembled and tested for comparison. The supercapacitor performances are verified by different electrochemical methods - cyclic voltammetry, galvanostatic charge/discharge measurements, electrochemical impedance spectroscopy, and long-term durability tests in neutral and alkaline electrolytes. Specific capacitances, energy, and power density, energy efficiencies, and durability were compared into studied supercapacitors. Ex-situ physicochemical analyses on the synthesized materials have also been performed, which provide information about chemical and structural changes in the electrode morphology during charge / discharge durability tests. They are discussed on the basis of electrode-electrolyte interaction. The obtained correlations could be of significance in order to design sustainable solid-state supercapacitors with high power and energy density. Acknowledgement: This research is funded by the Ministry of Education and Science of Bulgaria under the National Program "European Scientific Networks" (Agreement D01-286 / 07.10.2020, D01-78/30.03.2021). Authors gratefully acknowledge.Keywords: carbon xerogel, electrochemical tests, neutral and alkaline electrolytes, supercapacitors
Procedia PDF Downloads 1361476 Blunt Abdominal Trauma Management in Adult Patients: An Investigation on Safety of Discharging Patients with Normal Initial Findings
Authors: Rahimi-Movaghar Vafa, Mansouri Pejman, Chardoli Mojtaba, Rezvani Samina
Abstract:
Introduction: Blunt abdominal trauma is one of the leading causes of morbidity and mortality in all age groups, but diagnosis of serious intra-abdominal pathology is difficult and most of the damages are obscure in the initial investigation. There is still controversy about which patients should undergo abdomen/pelvis CT, which patients needs more observation and which patients can be discharged safely The aim of this study was to determine that is it safe to discharge patients with blunt abdominal trauma with normal initial findings. Methods: This non-randomized cross-sectional study was conducted from September 2013 to September 2014 at two levels I trauma centers, Sina hospital and Rasoul-e-Akram hospital (Tehran, Iran). Our inclusion criteria were all patients were admitted for suspicious BAT and our exclusion criteria were patients that have serious head and neck, chest, spine and limb injuries which need surgical intervention, those who have unstable vital signs, pregnant women with a gestational age over 3 months and homeless or without exact home address. 390 patients with blunt trauma abdomen examined and the necessary data, including demographic data, the abdominal examination, FAST result, patients’ lab test results (hematocrit, base deficit, urine analysis) on admission and at 6 and 12 hours after admission were recorded. Patients with normal physical examination, laboratory tests and FAST were discharged from the ED during 12 hours with the explanation of the alarm signs and were followed up after 24 hours and 1 week by a telephone call. Patients with abnormal findings in physical examination, laboratory tests, and FAST underwent abdomino-pelvic CT scan. Results: The study included 390 patients with blunt abdominal trauma between 12 and 80 years of age (mean age, 37.0 ± 13.7 years) and the mean duration of hospitalization in patients was 7.4 ± 4.1 hours. 88.6% of the patients were discharged from hospital before 12 hours. Odds ratio (OR) for having any symptoms for discharge after 6 hours was 0.160 and after 12 hours was 0.117 hours, which is statistically significant. Among the variables age, systolic and diastolic blood pressure, heart rate, respiratory rate, hematocrit and base deficit at admission, 6 hours and 12 hours after admission showed no significant statistical relationship with discharge time. From our 390 patients, 190 patients have normal initial physical examination, lab data and FAST findings that didn’t show any signs or symptoms in their next assessment and in their follow up by the phone call. Conclusion: It is recommended that patients with no symptoms at admission (completely normal physical examination, ultrasound, normal hematocrit and normal base deficit and lack of microscopic hematuria) and good family and social status can be safely discharged from the emergency department.Keywords: blunt abdominal trauma, patient discharge, emergency department, FAST
Procedia PDF Downloads 3651475 Offshore Wind Assessment and Analysis for South Western Mediterranean Sea
Authors: Abdallah Touaibia, Nachida Kasbadji Merzouk, Mustapha Merzouk, Ryma Belarbi
Abstract:
accuracy assessment and a better understand of the wind resource distribution are the most important tasks for decision making before installing wind energy operating systems in a given region, there where our interest come to the Algerian coastline and its Mediterranean sea area. Despite its large coastline overlooking the border of Mediterranean Sea, there is still no strategy encouraging the development of offshore wind farms in Algerian waters. The present work aims to estimate the offshore wind fields for the Algerian Mediterranean Sea based on wind data measurements ranging from 1995 to 2018 provided of 24 years of measurement by seven observation stations focusing on three coastline cities in Algeria under a different measurement time step recorded from 30 min, 60 min, and 180 min variate from one to each other, two stations in Spain, two other ones in Italy and three in the coast of Algeria from the east Annaba, at the center Algiers, and to Oran taken place at the west of it. The idea behind consists to have multiple measurement points that helping to characterize this area in terms of wind potential by the use of interpolation method of their average wind speed values between these available data to achieve the approximate values of others locations where aren’t any available measurement because of the difficulties against the implementation of masts within the deep depth water. This study is organized as follow: first, a brief description of the studied area and its climatic characteristics were done. After that, the statistical properties of the recorded data were checked by evaluating wind histograms, direction roses, and average speeds using MatLab programs. Finally, ArcGIS and MapInfo soft-wares were used to establish offshore wind maps for better understanding the wind resource distribution, as well as to identify windy sites for wind farm installation and power management. The study pointed out that Cap Carbonara is the windiest site with an average wind speed of 7.26 m/s at 10 m, inducing a power density of 902 W/m², then the site of Cap Caccia with 4.88 m/s inducing a power density of 282 W/m². The average wind speed of 4.83 m/s is occurred for the site of Oran, inducing a power density of 230 W/m². The results indicated also that the dominant wind direction where the frequencies are highest for the site of Cap Carbonara is the West with 34%, an average wind speed of 9.49 m/s, and a power density of 1722 W/m². Then comes the site of Cap Caccia, where the prevailing wind direction is the North-west, about 20% and 5.82 m/s occurring a power density of 452 W/m². The site of Oran comes in third place with the North dominant direction with 32% inducing an average wind speed of 4.59 m/s and power density of 189 W/m². It also shown that the proposed method is either crucial in understanding wind resource distribution for revealing windy sites over a large area and more effective for wind turbines micro-siting.Keywords: wind ressources, mediterranean sea, offshore, arcGIS, mapInfo, wind maps, wind farms
Procedia PDF Downloads 1411474 Efficacy and Safety of Combination Therapy in Androgenetic Alopecia: Randomized Uncontrolled Evaluator, Blind Study
Authors: Shivani Dhande, Sanjiv Choudhary, Adarshlata Singh
Abstract:
Introduction: Early age of onset of baldness has marked psychological impact on personality. Combination therapies have better efficacy than monotherapy in androgenetic alopecia. Although medical, surgical treatment and cosmetic aids are available for treatment of pattern baldness, medical is first preferred the line of treatment. Although only 5% topical minoxidil is USFDA approved, 10% is available in India since 2007. Efficacy of tablet finasteride is well established in male pattern baldness. 5% topical minoxidil is effective and safe in female pattern baldness. There is a role of saw palmetto in regrowth of scalp hair. With this background research was undertaken to study efficacy and safety of topical minoxidil 10% + tab. Finesteride (1mg) + dermaroller in male pattern baldness and topical minoxidil 5% + cap. Saw palmetto (320 mg) + dermaroller in female pattern baldness. Methods and Materials: It was a randomized uncontrolled evaluator blind study consisting of total 21 patients, 15 of male pattern baldness and 6 of female pattern baldness within 20-35 yrs of age were enrolled. Male patients had Hamilton grade 2-4 MPB and females had Ludwig grade 2 FPB. Male patients were treated with Tab Finesteride 1mg once daily + 10% topical Minoxidil 1ml twice daily for 6 months. Female patients were treated with Cap. Saw palmetto 320 mg once daily + 5% topical Minoxidil twice daily for 6 months. In both male & female patients dermaroller therapy was used once in 10 days for 4 sittings followed by once in 15 days for next 5 months. Blood pressure and possible side effects were monitored in every follow up visits. Pre and post treatment photographs were taken. Assessment of hair growth was done at baseline and at the end of 6 months. Patients satisfactory grading scale and Physician assessment of hair growth scale were used to assessing the results. Trichoscan was done for assessment of hair-shaft diameter and density. Pre and post treatment photographs and Trichoscan hair growth analysis (by diameter and density) was done by physician (dermatologist) not directly involved in this study (evaluator blind). Result: This combination therapy showed moderate response in female pattern alopecia and good to excellent results in male pattern alopecia at the end of 6 months. During therapy none of the patients showed side effects like hypotension, headache and loss of libido, hirsuitism. Mild irritation due to crystal deposition was noted by 3 patients. Conclusion: Effective and early treatment using combination therapy with higher percent of Minoxidil for rapid hair growth is necessary in initial period since it will boost up the self-confidence in patients leading to better treatment compliance. Subsequent maintenance of hair growth can be done with lower concentration. No significant side effects with treatment are observed in both group of patients.Keywords: androgenetic alopecia, dermaroller, finasteride, minoxidil, saw palmetto
Procedia PDF Downloads 2471473 Adaptation and Validation of Voice Handicap Index in Telugu Language
Authors: B. S. Premalatha, Kausalya Sahani
Abstract:
Background: Voice is multidimensional which convey emotion, feelings, and communication. Voice disorders have an adverse effect on the physical, emotional and functional domains of an individual. Self-rating by clients about their voice problem helps the clinicians to plan intervention strategies. Voice handicap index is one such self-rating scale contains 30 questions that quantify the functional, physical and emotional impacts of a voice disorder on a patient’s quality of life. Each subsection has 10 questions. Though adapted and validated versions of VHI are available in other Indian languages but not in Telugu, which is a Dravidian language native to India. It is mainly spoken in Andhra Pradesh and neighbouring states in southern India. Objectives: To adapt and validate the English version of Voice Handicap Index (VHI) into Telugu language and evaluate its internal consistency and clinical validate in Telugu speaking population. Materials: The study carried out in three stages. First stage was a forward translation of English version of VHI, was given to ten experts, who were well proficient in writing and reading Telugu and five speech-language pathologists to translate into Telugu. Second Stage was backward translation where translated version of Telugu was given to a different group of ten experts (who were well proficient in writing and reading Telugu) and five speech-language pathologists who were native Telugu speakers and had good proficiency in Telugu and English. The third stage was an administration of translated version on Telugu to the targeted population. Totally 40 clinical subjects and 40 normal controls served as participants, and each group had 26 males and 14 females’ age range of 20 to 60 years. Clinical group comprised of individuals with laryngectomee with the Tracheoesophageal puncture (n=18), laryngitis (n=11), vocal nodules (n=7) and vocal fold palsy (n=4). Participants were asked to mark of their each experience on a 5 point equal appearing scale (0=never, 1=almost never, 2=sometimes, 3=almost always, 4=always) with a maximum total score of 120. Results: Statistical analysis was made by using SPSS software (22.0.0 Version). Mean, standard deviation and percentage (%) were calculated all the participants for both the groups. Internal consistency of VHI in Telugu was found to be excellent with the consistency scores for all the domains such as physical, emotional and functional are 0.742, 0.934and 0.938. The validity of scores showed a significant difference between clinical population and control group for domains like physical, emotional and functional and total scores. P value found to be less than 0.001( < 0.001). Negative correlation found in age and gender among self-domains such as physical, emotional and functional total scores in dysphonic and control group. Conclusion: The present study indicated that VHI in Telugu is able to discriminate participants having voice pathology from normal populations, which make this as a valid tool to collect information about their voice from the participants.Keywords: adaptation, Telugu Version, translation, Voice Handicap Index (VHI)
Procedia PDF Downloads 2751472 Metamorphosis of Caste: An Examination of the Transformation of Caste from a Material to Ideological Phenomenon in Sri Lanka
Authors: Pradeep Peiris, Hasini Lecamwasam
Abstract:
The fluid, ambiguous, and often elusive existence of caste among the Sinhalese in Sri Lanka has inspired many scholarly endeavours. Originally, Sinhalese caste was organized according to the occupational functions assigned to various groups in society. Hence cultivators came to be known as Goyigama, washers Dobi, drummers Berava, smiths Navandanna and so on. During pre-colonial times the specialized services of various groups were deployed to build water reservoirs, cultivate the land, and/or sustain the Buddhist order by material means. However, as to how and why caste prevails today in Sinhalese society when labour is in ideal terms free to move where it wants, or in other words, occupation is no longer strictly determined or restricted by birth, is a question worth exploring. Hence this paper explores how, and perhaps more interestingly why, when the nexus between traditional occupations and caste status is fast disappearing, caste itself has managed to survive and continues to be salient in politics in Sri Lanka. In answer to this larger question, the paper looks at caste from three perspectives: 1) Buddhism, whose ethical project provides a justification of social stratifications that transcends economic bases 2) Capitalism that has reactivated and reproduced archaic relations in a process of 'accumulation by subordination', not only by reinforcing the marginality of peripheral caste groups, but also by exploiting caste divisions to hinder any realization of class interests and 3) Democracy whose supposed equalizing effect expected through its ‘one man–one vote’ approach has been subverted precisely by itself, whereby the aggregate ultimately comes down to how many such votes each ‘group’ in society has. This study draws from field work carried out in Dedigama (in the District of Kegalle, Central Province) and Kelaniya (in the District of Colombo, Western Province) in Sri Lanka over three years. The choice of field locations was encouraged by the need to capture rural and urban dynamics related to caste since caste is more apparently manifest in rural areas whose material conditions partially warrant its prevalence, whereas in urban areas it exists mostly in the ideological terrain. In building its analysis, the study has employed a combination of objectivist and subjectivist approaches to capture the material and ideological existence of caste and caste politics in Sinhalese society. Therefore, methods such as in-depth interviews, observation, and collection of demographical and interpretive data from secondary sources were used for this study. The paper has been situated in a critical theoretical framework of social inquiry in an attempt to question dominant assumptions regarding such meta-labels as ‘Capitalism’ and ‘Democracy’, and also the supposed emancipatory function of religion (focusing on Buddhism).Keywords: Buddhism, capitalism, caste, democracy, Sri Lanka
Procedia PDF Downloads 1341471 Analysis of Resistance and Virulence Genes of Gram-Positive Bacteria Detected in Calf Colostrums
Authors: C. Miranda, S. Cunha, R. Soares, M. Maia, G. Igrejas, F. Silva, P. Poeta
Abstract:
The worldwide inappropriate use of antibiotics has increased the emergence of antimicrobial-resistant microorganisms isolated from animals, humans, food, and the environment. To combat this complex and multifaceted problem is essential to know the prevalence in livestock animals and possible ways of transmission among animals and between these and humans. Enterococci species, in particular E. faecalis and E. faecium, are the most common nosocomial bacteria, causing infections in animals and humans. Thus, the aim of this study was to characterize resistance and virulence factors genes among two enterococci species isolated from calf colostrums in Portuguese dairy farms. The 55 enterococci isolates (44 E. faecalis and 11 E. faecium) were tested for the presence of the resistance genes for the following antibiotics: erythromicyn (ermA, ermB, and ermC), tetracycline (tetL, tetM, tetK, and tetO), quinupristin/dalfopristin (vatD and vatE) and vancomycin (vanB). Of which, 25 isolates (15 E. faecalis and 10 E. faecium) were tested until now for 8 virulence factors genes (esp, ace, gelE, agg, cpd, cylA, cylB, and cylLL). The resistance and virulence genes were performed by PCR, using specific primers and conditions. Negative and positive controls were used in all PCR assays. All enterococci isolates showed resistance to erythromicyn and tetracycline through the presence of the genes: ermB (n=29, 53%), ermC (n=10, 18%), tetL (n=49, 89%), tetM (n=39, 71%) and tetK (n=33, 60%). Only two (4%) E. faecalis isolates showed the presence of tetO gene. No resistance genes for vancomycin were found. The virulence genes detected in both species were cpd (n=17, 68%), agg (n=16, 64%), ace (n=15, 60%), esp (n=13, 52%), gelE (n=13, 52%) and cylLL (n=8, 32%). In general, each isolate showed at least three virulence genes. In three E. faecalis isolates was not found virulence genes and only E. faecalis isolates showed virulence genes for cylA (n=4, 16%) and cylB (n=6, 24%). In conclusion, these colostrum samples that were consumed by calves demonstrated the presence of antibiotic-resistant enterococci harbored virulence genes. This genotypic characterization is crucial to control the antibiotic-resistant bacteria through the implementation of restricts measures safeguarding public health. Acknowledgements: This work was funded by the R&D Project CAREBIO2 (Comparative assessment of antimicrobial resistance in environmental biofilms through proteomics - towards innovative theragnostic biomarkers), with reference NORTE-01-0145-FEDER-030101 and PTDC/SAU-INF/30101/2017, financed by the European Regional Development Fund (ERDF) through the Northern Regional Operational Program (NORTE 2020) and the Foundation for Science and Technology (FCT). This work was supported by the Associate Laboratory for Green Chemistry - LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020).Keywords: antimicrobial resistance, calf, colostrums, enterococci
Procedia PDF Downloads 1951470 Excess Body Fat as a Store Toxin Affecting the Glomerular Filtration and Excretory Function of the Liver in Patients after Renal Transplantation
Authors: Magdalena B. Kaziuk, Waldemar Kosiba, Marek J. Kuzniewski
Abstract:
Introduction: Adipose tissue is a typical place for storage water-insoluble toxins in the body. It's connective tissue, where the intercellular substance consist of fat, which level in people with low physical activity should be 18-25% for women and 13-18% for men. Due to the fat distribution in the body we distinquish two types of obesity: android (visceral, abdominal) and gynoidal (gluteal-femoral, peripheral). Abdominal obesity increases the risk of complications of the cardiovascular system diseases, and impaired renal and liver function. Through the influence on disorders of metabolism, lipid metabolism, diabetes and hypertension, leading to emergence of the metabolic syndrome. So thus, obesity will especially overload kidney function in patients after transplantation. Aim: An attempt was made to estimate the impact of amount fat tissue on transplanted kidney function and excretory function of the liver in patients after Ktx. Material and Methods: The study included 108 patients (50 females, 58 male, age 46.5 +/- 12.9 years) with active kidney transplant after more than 3 months from the transplantation. An analysis of body composition was done by using electrical bioimpedance (BIA) and anthropometric measurements. Estimated basal metabolic rate (BMR), muscle mass, total body water content and the amount of body fat. Information about physical activity were obtained during clinical examination. Nutritional status, and type of obesity were determined by using indicators: Waist to Height Ratio (WHR) and Waist to Hip Ratio (WHR). Excretory functions of the transplanted kidney was rated by calculating the estimated renal glomerular filtration rate (eGFR) using the MDRD formula. Liver function was rated by total bilirubin and alanine aminotransferase levels ALT concentration in serum. In our patients haemolitic uremic syndrome (HUS) was excluded. Results: In 19.44% of patients had underweight, 22.37% of the respondents were with normal weight, 11.11% had overweight, and the rest were with obese (49.08%). People with android stature have a lower eGFR compared with those with the gynoidal stature (p = 0.004). All patients with obesity had higher amount of body fat from a few to several percent. The higher amount of body fat percentage, the lower eGFR had patients (p <0.001). Elevated ALT levels significantly correlated with a high fat content (p <0.02). Conclusion: Increased amount of body fat, particularly in the case of android obesity can be a predictor of kidney and liver damage. Due to that obese patients should have more frequent control of diagnostic functions of these organs and the intensive dietary proceedings, pharmacological and regular physical activity adapted to the current physical condition of patients after transplantation.Keywords: obesity, body fat, kidney transplantation, glomerular filtration rate, liver function
Procedia PDF Downloads 4601469 Dietary Flaxseed Decreases Central Blood Pressure and the Concentrations of Plasma Oxylipins Associated with Hypertension in Patients with Peripheral Arterial Disease
Authors: Stephanie PB Caligiuri, Harold M Aukema, Delfin Rodriguez-Leyva, Amir Ravandi, Randy Guzman, Grant N. Pierce
Abstract:
Background: Hypertension leads to cardiac and cerebral events and therefore is the leading risk factor attributed to death in the world. Oxylipins may be mediators in these events as they can regulate vascular tone and inflammation. Oxylipins are derived from fatty acids. Dietary flaxseed is rich in the n3 fatty acid, alpha-linolenic acid, and, therefore, may have the ability to change the substrate profile of oxylipins. As a result, this could alter blood pressure. Methods: A randomized, double-blinded, controlled clinical trial, the Flax-PAD trial, was used to assess the impact of dietary flaxseed on blood pressure (BP), and to also assess the relationship of plasma oxylipins to BP in 81 patients with peripheral arterial disease (PAD). Patients with PAD were chosen for the clinical trial as they are at an increased risk for hypertension and cardiac and cerebral events. Thirty grams of ground flaxseed were added to food products to consume on a daily basis for 6 months. The control food products contained wheat germ, wheat bran, and mixed dietary oils instead of flaxseed. Central BP, which is more significantly associated to organ damage, cardiac, and cerebral events versus brachial BP, was measured by pulse wave analysis at baseline and 6 months. A plasma profile of 43 oxylipins was generated using solid phase extraction, HPLC-MS/MS, and stable isotope dilution quantitation. Results: At baseline, the central BP (systolic/diastolic) in the placebo and flaxseed group were, 131/73 ± 2.5/1.4 mmHg and 128/71 ± 2.6/1.4 mmHg, respectively. After 6 months of intervention, the flaxseed group exhibited a decrease in blood pressure of 4.0/1.0 mmHg. The 6 month central BP in the placebo and flaxseed groups were, 132/74 ± 2.9/1.8 mmHg and 124/70 ± 2.6/1.6 mmHg (P<0.05). Correlation and logistic regression analyses between central blood pressure and oxylipins were performed. Significant associations were observed between central blood pressure and 17 oxylipins, primarily produced from arachidonic acid. Every 1 nM increase in 16-hydroxyeicosatetraenoic acid (HETE) increased the odds of having high central systolic BP by 15-fold, of having high central diastolic BP by 6-fold and of having high central mean arterial pressure by 15-fold. In addition, every 1 nM increase in 5,6-dihydroxyeicosatrienoic acid (DHET) and 11,12-DHET increased the odds of having high central mean arterial pressure by 45- and 18-fold, respectively. Flaxseed induced a significant decrease in these as well as 4 other vasoconstrictive oxylipins. Conclusion: Dietary flaxseed significantly lowered blood pressure in patients with PAD and hypertension. Plasma oxylipins were strongly associated with central blood pressure and may have mediated the flaxseed-induced decrease in blood pressure.Keywords: hypertension, flaxseed, oxylipins, peripheral arterial disease
Procedia PDF Downloads 4651468 The Highly Dispersed WO3-x Photocatalyst over the Confinement Effect of Mesoporous SBA-15 Molecular Sieves for Photocatalytic Nitrogen Reduction
Authors: Xiaoling Ren, Guidong Yang
Abstract:
As one of the largest industrial synthetic chemicals in the world, ammonia has the advantages of high energy density, easy liquefaction, and easy transportation, which is widely used in agriculture, chemical industry, energy storage, and other fields. The industrial Haber-Bosch method process for ammonia synthesis is generally conducted under severe conditions. It is essential to develop a green, sustainable strategy for ammonia production to meet the growing demand. In this direction, photocatalytic nitrogen reduction has huge advantages over the traditional, well-established Haber-Bosch process, such as the utilization of natural sun light as the energy source and significantly lower pressure and temperature to affect the reaction process. However, the high activation energy of nitrogen and the low efficiency of photo-generated electron-hole separation in the photocatalyst result in low ammonia production yield. Many researchers focus on improving the catalyst. In addition to modifying the catalyst, improving the dispersion of the catalyst and making full use of active sites are also means to improve the overall catalytic activity. Few studies have been carried out on this, which is the aim of this work. In this work, by making full use of the nitrogen activation ability of WO3-x with defective sites, small size WO3-x photocatalyst with high dispersibility was constructed, while the growth of WO3-x was restricted by using a high specific surface area mesoporous SBA-15 molecular sieve with the regular pore structure as a template. The morphology of pure SBA-15 and WO3-x/SBA-15 was characterized byscanning electron microscopy (SEM). Compared with pure SBA-15, some small particles can be found in the WO3-x/SBA-15 material, which means that WO3-x grows into small particles under the limitation of SBA-15, which is conducive to the exposure of catalytically active sites. To elucidate the chemical nature of the material, the X-ray diffraction (XRD) analysis was conducted. The observed diffraction pattern inWO3-xis in good agreement with that of the JCPDS file no.71-2450. Compared with WO3-x, no new peaks appeared in WO3-x/SBA-15.It can be concluded that WO3-x/SBA-15 was synthesized successfully. In order to provide more active sites, the mass content of WO3-x was optimized. Then the photocatalytic nitrogen reduction performances of above samples were performed with methanol as a hole scavenger. The results show that the overall ammonia production performance of WO3-x/SBA-15 is improved than pure bulk WO3-x. The above results prove that making full use of active sites is also a means to improve overall catalytic activity.This work provides material basis for the design of high-efficiency photocatalytic nitrogen reduction catalysts.Keywords: ammonia, photocatalytic, nitrogen reduction, WO3-x, high dispersibility
Procedia PDF Downloads 1571467 An Overview on Micro Irrigation-Accelerating Growth of Indian Agriculture
Authors: Rohit Lall
Abstract:
The adoption of Micro Irrigation (MI) technologies in India has helped in achieving higher cropping and irrigation intensity with significant savings on resource savings such as labour, fertilizer and improved crop yields. These technologies have received considerable attention from policymakers, growers and researchers over the years for its perceived ability to contribute towards agricultural productivity and economic growth with the well-being of the growers of the country. Keeping the pace with untapped theoretical potential to cover government had launched flagship programs/centre sector schemes with earmarked budget to capture the potential under these waters saving techniques envisaged under these technologies by way of providing financial assistance to the beneficiaries for adopting these technologies. Micro Irrigation technologies have been in the special attention of the policymakers over the years. India being an agrarian economy having engaged 75% of the population directly or indirectly having skilled, semi-skilled and entrepreneurs in the sector with focused attention and financial allocations from the government under these technologies in covering the untapped potential under Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) 'Per Drop More Crop component.' During the year 2004, a Taskforce on Micro Irrigation was constituted to estimate the potential of these technologies in India which was estimated 69.5 million hectares by the Task Force Report on MI however only 10.49 million hectares have been achieved so far. Technology collaborations by leading manufacturing companies in overseas have proved to a stepping stone in technology advancement and product up gradation with increased efficiencies. Joint ventures by the leading MI companies have added huge business volumes which have not only accelerated the momentum of achieving the desired goal but in terms of area coverage but had also generated opportunities for the polymer manufacturers in the country. To provide products matching the global standards Bureau of Indian Standards have constituted a sectional technical committee under the Food and Agriculture Department (FAD)-17 to formulated/devise and revise standards pertaining to MI technologies. The research lobby has also contributed at large by developing in-situ analysis proving MI technologies a boon for farming community of the country with resource conservation of which water is of paramount importance. Thus, Micro Irrigation technologies have proved to be the key tool for feeding the grueling demand of food basket of the growing population besides maintaining soil health and have been contributing towards doubling of farmers’ income.Keywords: task force on MI, standards, per drop more crop, doubling farmers’ income
Procedia PDF Downloads 1161466 Features of Composites Application in Shipbuilding
Authors: Valerii Levshakov, Olga Fedorova
Abstract:
Specific features of ship structures, made from composites, i.e. simultaneous shaping of material and structure, large sizes, complicated outlines and tapered thickness have defined leading role of technology, integrating test results from material science, designing and structural analysis. Main procedures of composite shipbuilding are contact molding, vacuum molding and winding. Now, the most demanded composite shipbuilding technology is the manufacture of structures from fiberglass and multilayer hybrid composites by means of vacuum molding. This technology enables the manufacture of products with improved strength properties (in comparison with contact molding), reduction of production duration, weight and secures better environmental conditions in production area. Mechanized winding is applied for the manufacture of parts, shaped as rotary bodies – i.e. parts of ship, oil and other pipelines, deep-submergence vehicles hulls, bottles, reservoirs and other structures. This procedure involves processing of reinforcing fiberglass, carbon and polyaramide fibers. Polyaramide fibers have tensile strength of 5000 MPa, elastic modulus value of 130 MPa and rigidity of the same can be compared with rigidity of fiberglass, however, the weight of polyaramide fiber is 30% less than weight of fiberglass. The same enables to the manufacture different structures, including that, using both – fiberglass and organic composites. Organic composites are widely used for the manufacture of parts with size and weight limitations. High price of polyaramide fiber restricts the use of organic composites. Perspective area of winding technology development is the manufacture of carbon fiber shafts and couplings for ships. JSC ‘Shipbuilding & Shiprepair Technology Center’ (JSC SSTC) developed technology of dielectric uncouplers for cryogenic lines, cooled by gaseous or liquid cryogenic agents (helium, nitrogen, etc.) for temperature range 4.2-300 K and pressure up to 30 MPa – the same is used for separating components of electro physical equipment with different electrical potentials. Dielectric uncouplers were developed, the manufactured and tested in accordance with International Thermonuclear Experimental Reactor (ITER) Technical specification. Spiral uncouplers withstand operating voltage of 30 kV, direct-flow uncoupler – 4 kV. Application of spiral channel instead of rectilinear enables increasing of breakdown potential and reduction of uncouplers sizes. 95 uncouplers were successfully the manufactured and tested. At the present time, Russian the manufacturers of ship composite structures have started absorption of technology of manufacturing the same using automated prepreg laminating; this technology enables the manufacture of structures with improved operational specifications.Keywords: fiberglass, infusion, polymeric composites, winding
Procedia PDF Downloads 236