Search results for: bio-sourced phase change material
Commenced in January 2007
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Paper Count: 16267

Search results for: bio-sourced phase change material

3667 Modeling Loads Applied to Main and Crank Bearings in the Compression-Ignition Two-Stroke Engine

Authors: Marcin Szlachetka, Mateusz Paszko, Grzegorz Baranski

Abstract:

This paper discusses the AVL EXCITE Designer simulation research into loads applied to main and crank bearings in the compression-ignition two-stroke engine. There was created a model of engine lubrication system which covers the part of this system related to particular nodes of a bearing system, i.e. a connection of main bearings in an engine block with a crankshaft, a connection of crank pins with a connecting rod. The analysis focused on the load given as a distribution of hydrodynamic oil film pressure corresponding different values of radial internal clearance. There was also studied the impact of gas force on minimal oil film thickness in main and crank bearings versus crankshaft rotational speed. Our model calculates oil film parameters, an oil film pressure distribution, an oil temperature change and dimensions of bearings as well as an oil temperature distribution on surfaces of bearing seats. Accordingly, it was possible to select, for example, a correct clearance for each of the node bearings. The research was performed for several values of engine crankshaft speed ranging from 800 RPM to 4000 RPM. Bearing oil pressure was changed according to engine speed ranging between 1 bar and 5 bar and an oil temperature of 90°C. The main bearing clearances made initially for the calculation and research were: 0.015 mm, 0.025 mm, 0.035 mm, 0.05 mm, 0.1 mm. The oil used for the research corresponded the SAE 5W-40 classification. The paper presents the selected research results referring to certain specific operating points and bearing radial internal clearances. Acknowledgement: This work has been realized in the cooperation with The Construction Office of WSK ‘PZL-KALISZ’ S.A. and is part of Grant Agreement No. POIR.01.02.00-00-0002/15 financed by the Polish National Centre for Research and Development.

Keywords: crank bearings, diesel engine, oil film, two-stroke engine

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3666 Factors Associated with Overweight and Obesity among Recipients of Antiretroviral Therapy at HIV Clinics in Botswana

Authors: Jose G. Tshikuka, Goabaone Rankgoane-Pono, Mgaywa G. M. D. Magafu, Julius C. Mwita, Tiny Masupe, Fortunat M. Kandanda, Shimeles G. Hamda, Roy Tapera, Mooketsi Molefi, John T. Tlhakanelo

Abstract:

Background: Factors associated with overweight and obesity among antiretroviral therapy (ART) recipients have not been sufficiently studied in Botswana. We aimed to study (i) the prevalence and trends in overweight/obesity by duration of exposure to ART among recipients, (ii) changes in body mass index (BMI) categories among recipients before ART initiation (BMI-1) and after ART initiation (BMI-2), (iii) associations between ART and overweight/obesity and (iv) factors associated with BMI changes among ART recipients. Methods: A 12 years retrospective record-based review was conducted. Factors potentially associated with BMI change among patients after at least three years of ART exposure were examined using multiple regression model. Adjusted odds ratios (AOR) and their 95% confidence intervals (CIs) were computed. ART regimens, duration of exposure to ART, and recipients’ demographic and biomedical characteristics including the presence or absence of diabetes mellitus related comorbidities (DRC) were investigated as potential factors associated with overweight/obesity. Results: Twenty-nine percent of recipients were overweight, 16.6% had obesity of whom 2.4% were morbidly-obese at the last clinic visit. Overweight/obesity recipients were more likely to be female, to have DRC and less likely to have nadir CD4 count or CD4 count between 201 – 249 cells/mm³. Neither the first-line nor the second-, third-line ART regimens predicted overweight/obesity more than the other and neither did the duration of exposure to ART. No significant linear trends were observed in the prevalence of overweight/obesity by the duration of exposure to ART. Conclusions: These results indicate that overweight/obesity seen among ART recipients is not directly induced by ART. ART used CD4 and/or DRC pathway to induce overweight/obesity seen among recipients; suggesting that, weight gain documented herein is likely a reflection of improved health status that mirrors trends in the general population or a DRC related effect. Weight management programs may be important components of HIV care.

Keywords: overweight/obesity, recipients of antiretroviral therapy, HIV/AIDS, Botswana

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3665 Sociology Curriculum and Capabilities Formation: A Case Study of Two South African Universities

Authors: B. Manyonga

Abstract:

Across the world, higher education (HE) is expanding rapidly and issues of curriculum change have become more contentious and political than ever before. Although research informing curricula review in social sciences and particularly sociology has been conducted, much analysis has been devoted to teaching and transmitting disciplinary knowledge, student identity and epistemology, with little focus on curriculum conceptualisation and capability formation. This paper builds on and contributes to accumulating knowledge in the field of sociology curriculum design in the South African HE context. Drawing from the principles of Capabilities Approach (CA) of Amartya Sen and Martha Nussbaum, the paper argues that sociology curriculum conceptualisation may be enriched by capabilities identification for students. Thus, the sociological canon ought to be the vehicle through which student capabilities could be developed. The CA throws a fresh light on how curriculum ought to be designed to offer students real opportunities, expanding choices for individuals to be what they want to be and do. The paper uses a case of two South African universities to present analysis of qualitative data collected from undergraduate sociology lecturers. The major findings of the paper indicate that there is no clear philosophy guiding the conceptualisation of curriculum. The conceptualisation is based on lecturer expertise, carrying out research, response to topical and societal issues. Sociology lecturers highlighted that they do not consult students on what they want to do and to be as a result of studying for a sociology degree. Although lecturers recognise some human development capabilities such as critical thinking, multiple perspectives and problem solving as important for sociology students, there is little evidence to illustrate how these are being cultivated in students. Taken together, the results suggest that sociological canon is being regarded as the starting point for curriculum planning and construction.

Keywords: capabilities approach, graduate attributes, higher education, sociology curriculum

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3664 Diagnosing Depression during Pregnancy-Identifying Risk Factors of Prenatal Depression in Polish Women

Authors: Olga Plaza, Katarzyna Kosinska-Kaczynska, Stepan Feduniw, Dominika Pazdzior, Kinga Zebrowska, Katarzyna Kwiatkowska

Abstract:

Introduction: The main causes of depression among pregnant women remain unclear. However, it is clear that pregnancy carries a higher risk of depression occurrence. Left untreated, prenatal depression can be a cause of serious both maternal and neonatal complications. Aim of the study: The aim of the study was to define potential risk factors of prenatal depression and to assess the frequency of its occurrence among pregnant women. Material and Methods: A prospective cross-sectional study was performed among 346 women. The self- composed questionnaire consisting of 46 questions, was distributed via the Internet between November 2017 and March 2018. The questionnaire contained the Edinburgh Postnatal Depression Scale (EPDS), in which the results of 13 and more points (out of 30) suggested possible prenatal depression. Statistical analysis was performed with Chi2 Pearson. P value < 0.05 was considered significant. Results: 37.57% (n=130) of women had a score of 13 or more points. Women with depressive symptoms (DS) reported lack of support from the partner (46.9% vs. 16.2%; p < 0.001) as well as other family members (40.8% vs. 14.4%; p < 0.001), current pregnancy being unplanned (21.5% vs. 12.5%; p=0.014) and low socio-economic status (10% vs. 0.9%; p < 0.001). Both early and advanced maternal age seemed to play a role in occurrence of DS: in women aged 17-24 40.8% declared symptoms (vs 28.7%; p < 0.01), in mothers aged ≥37 6.2% did (vs 0.5%; p < 0.001). Smoking during pregnancy was also more frequent among patients with DS (31.5% vs. 18.1%; p=0.004). Previous diagnosis of depression or other mood disorders significantly increased a chance of DS occurrence (respectively- 17.7% vs. 4.6%; p < 0.001 and 49.2% vs. 25%; p<0.001). Parental diagnosis of mood disorders and other mental disorders was also more frequent in this group of patients (respectively- 24.6% vs. 15.7%; p= 0.026 and 26.4% vs. 9.7%; p < 0.001). Only 23.8% of women with DS sought help from healthcare professionals, with 21.5% receiving pharmacological treatment. Conclusions: Pregnant women often report having DS. Evaluation of risk factors of DS and possible prenatal depression is essential in proper screening for depression among pregnant women.

Keywords: obstetrics, polish women, prenatal care, prenatal depression, risk factors

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3663 Deproteinization of Moroccan Sardine (Sardina pilchardus) Scales: A Pilot-Scale Study

Authors: F. Bellali, M. Kharroubi, Y. Rady, N. Bourhim

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In Morocco, fish processing industry is an important source income for a large amount of by-products including skins, bones, heads, guts, and scales. Those underutilized resources particularly scales contain a large amount of proteins and calcium. Sardina plichardus scales from resulting from the transformation operation have the potential to be used as raw material for the collagen production. Taking into account this strong expectation of the regional fish industry, scales sardine upgrading is well justified. In addition, political and societal demands for sustainability and environment-friendly industrial production systems, coupled with the depletion of fish resources, drive this trend forward. Therefore, fish scale used as a potential source to isolate collagen has a wide large of applications in food, cosmetic, and biomedical industry. The main aim of this study is to isolate and characterize the acid solubilize collagen from sardine fish scale, Sardina pilchardus. Experimental design methodology was adopted in collagen processing for extracting optimization. The first stage of this work is to investigate the optimization conditions of the sardine scale deproteinization on using response surface methodology (RSM). The second part focus on the demineralization with HCl solution or EDTA. And the last one is to establish the optimum condition for the isolation of collagen from fish scale by solvent extraction. The advancement from lab scale to pilot scale is a critical stage in the technological development. In this study, the optimal condition for the deproteinization which was validated at laboratory scale was employed in the pilot scale procedure. The deproteinization of fish scale was then demonstrated on a pilot scale (2Kg scales, 20l NaOH), resulting in protein content (0,2mg/ml) and hydroxyproline content (2,11mg/l). These results indicated that the pilot-scale showed similar performances to those of lab-scale one.

Keywords: deproteinization, pilot scale, scale, sardine pilchardus

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3662 Powerful Media: Reflection of Professional Audience

Authors: Hamide Farshad, Mohammadreza Javidi Abdollah Zadeh Aval

Abstract:

As a result of the growing penetration of the media into human life, a new role under the title of "audience" is defined in the social life .A kind of role which is dramatically changed since its formation. This article aims to define the audience position in the new media equations which is concluded to the transformation of the media role. By using the Library and Attributive method to study the history, the evolutionary outlook to the audience and the recognition of the audience and the media relation in the new media context is studied. It was perceived in past that public communication would result in receiving the audience. But after the emergence of the interactional media and transformation in the audience social life, a new kind of public communication is formed, and also the imaginary picture of the audience is replaced by the audience impact on the communication process. Part of this impact can be seen in the form of feedback which is one of the public communication elements. In public communication, the audience feedback is completely accepted. But in many cases, and along with the audience feedback, the media changes its direction; this direction shift is known as media feedback. At this state, the media and the audience are both doers and consistently change their positions in an interaction. With the greater number of the audience and the media, this process has taken a new role, and the role of this doer is sometimes taken by an audience while influencing another audience, or a media while influencing another media. In this article, this multiple public communication process is shown through representing a model under the title of ”The bilateral influence of the audience and the media.” Based on this model, the audience and the media power are not the two sides of a coin, and as a result, by accepting these two as the doers, the bilateral power of the audience and the media will be complementary to each other. Also more, the compatibility between the media and the audience is analyzed in the bilateral and interactional relation hypothesis, and by analyzing the action law hypothesis, the dos and don’ts of this role are defined, and media is obliged to know and accept them in order to be able to survive. They also have a determining role in the strategic studies of a media.

Keywords: audience, effect, media, interaction, action laws

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3661 Synthesis of ZnFe₂O₄-AC/CeMOF for Improvement Photodegradation of Textile Dyes Under Visible-light: Optimization and Statistical Study

Authors: Esraa Mohamed El-Fawal

Abstract:

A facile solvothermal procedure was applied to fabricate zinc ferrite nanoparticles (ZnFe₂O₄ NPs). Activated carbon (AC) derived from peanut shells is synthesized using a microwave through the chemical activation method. The ZnFe₂O₄-AC composite is then mixed with a cerium-based metal-organic framework (CeMOF) by solid-state adding to formulate ZnFe₂O₄-AC/CeMOF composite. The synthesized photo materials were tested by scanning/transmission electron microscope (SEM/TEM), Photoluminescence (PL), (XRD) X-Ray diffraction, (FTIR) Fourier transform infrared, (UV-Vis/DRS) ultraviolet-visible/diffuse reflectance spectroscopy. The prepared ZnFe₂O₄-AC/CeMOFphotomaterial shows significantly boosted efficiency for photodegradation of methyl orange /methylene blue (MO/MB) compared with the pristine ZnFe₂O₄ and ZnFe₂O₄-AC composite under the irradiation of visible-light. The favorable ZnFe₂O₄-AC/CeMOFphotocatalyst displays the highest photocatalytic degradation efficiency of MB/MO (R: 91.5-88.6%, consecutively) compared with the other as-prepared materials after 30 min of visible-light irradiation. The apparent reaction rate K: 1.94-1.31 min-1 is also calculated. The boosted photocatalytic proficiency is ascribed to the heterojunction at the interface of prepared photo material that assists the separation of the charge carriers. To reach optimization, statistical analysis using response surface methodology was applied. The effect of independent parameters (such as A (pH), B (irradiation time), and (c) initial pollutants concentration on the response function (%)photodegradation of MB/MO dyes (as examples of azodyes) was investigated via using central composite design. At the optimum condition, the photodegradation efficiency (%) of the MB/MO is 99.8-97.8%, respectively. ZnFe2O₄-AC/CeMOF hybrid reveals good stability over four consecutive cycles.

Keywords: azo-dyes, photo-catalysis, zinc ferrite, response surface methodology

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3660 Assessing the Legacy Effects of Wildfire on Eucalypt Canopy Structure of South Eastern Australia

Authors: Yogendra K. Karna, Lauren T. Bennett

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Fire-tolerant eucalypt forests are one of the major forest ecosystems of south-eastern Australia and thought to be highly resistant to frequent high severity wildfires. However, the impact of different severity wildfires on the canopy structure of fire-tolerant forest type is under-studied, and there are significant knowledge gaps in relation to the assessment of tree and stand level canopy structural dynamics and recovery after fire. Assessment of canopy structure is a complex task involving accurate measurements of the horizontal and vertical arrangement of the canopy in space and time. This study examined the utility of multitemporal, small-footprint lidar data to describe the changes in the horizontal and vertical canopy structure of fire-tolerant eucalypt forests seven years after wildfire of different severities from the tree to stand level. Extensive ground measurements were carried out in four severity classes to describe and validate canopy cover and height metrics as they change after wildfire. Several metrics such as crown height and width, crown base height and clumpiness of crown were assessed at tree and stand level using several individual tree top detection and measurement algorithm. Persistent effects of high severity fire 8 years after both on tree crowns and stand canopy were observed. High severity fire increased the crown depth but decreased the crown projective cover leading to more open canopy.

Keywords: canopy gaps, canopy structure, crown architecture, crown projective cover, multi-temporal lidar, wildfire severity

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3659 Changing Roles and Skills of Urban Planners in the Turkish Planning System

Authors: Fatih Eren

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This research aims to find an answer to the question of which knowledge and skills do the Turkish urban planners need in their business practice. Understanding change in cities, making a prediction, making an urban decision and putting it into practice, working together with actors from different organizations from various academic disciplines, persuading people to accept something and developing good personal and professional relationships have become very complex and difficult in today’s world. The truth is that urban planners work in many institutions under various positions which are not similar to each other by field of activity and all planners are forced to develop some knowledge and skills for success in their business in Turkey. This study targets to explore what urban planners do in the global information age. The study is the product of a comprehensive nation-wide research. In-depth interviews were conducted with 174 experienced urban planners, who work in different public institutions and private companies under varied positions in the Turkish Planning System, to find out knowledge and skills needed by next-generation urban planners. The main characteristics of next-generation urban planners are defined; skills that planners needed today are explored in this paper. Findings show that the positivist (traditional) planning approach has given place to anti-positivist planning approaches in the Turkish Planning System so next-generation urban planners who seek success and want to carve out a niche for themselves in business life have to equip themselves with innovative skills. The result section also includes useful and instructive findings for planners about what is the meaning of being an urban planner and what is the ideal content and context of planning education at universities in the global age.

Keywords: global information age, Turkish Planning System, the institutional approach, urban planners, roles, skills, values

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3658 Optimization of Sodium Lauryl Surfactant Concentration for Nanoparticle Production

Authors: Oluwatoyin Joseph Gbadeyan, Sarp Adali, Bright Glen, Bruce Sithole

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Sodium lauryl surfactant concentration optimization, for nanoparticle production, provided the platform for advanced research studies. Different concentrations (0.05 %, 0.1 %, and 0.2 %) of sodium lauryl surfactant was added to snail shells powder during milling processes for producing CaCO3 at smaller particle size. Epoxy nanocomposites prepared at filler content 2 wt.% synthesized with different volumes of sodium lauryl surfactant were fabricated using a conventional resin casting method. Mechanical properties such as tensile strength, stiffness, and hardness of prepared nanocomposites was investigated to determine the effect of sodium lauryl surfactant concentration on nanocomposite properties. It was observed that the loading of the synthesized nano-calcium carbonate improved the mechanical properties of neat epoxy at lower concentrations of sodium lauryl surfactant 0.05 %. Meaningfully, loading of achatina fulica snail shell nanoparticles manufactures, with small concentrations of sodium lauryl surfactant 0.05 %, increased the neat epoxy tensile strength by 26%, stiffness by 55%, and hardness by 38%. Homogeneous dispersion facilitated, by the addition of sodium lauryl surfactant during milling processes, improved mechanical properties. Research evidence suggests that nano-CaCO3, synthesized from achatina fulica snail shell, possesses suitable reinforcement properties that can be used for nanocomposite fabrication. The evidence showed that adding small concentrations of sodium lauryl surfactant 0.05 %, improved dispersion of nanoparticles in polymetrix material that provided mechanical properties improvement.

Keywords: sodium lauryl surfactant, mechanical properties , achatina fulica snail shel, calcium carbonate nanopowder

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3657 The Incidence of Obesity among Adult Women in Pekanbaru City, Indonesia, Related to High Fat Consumption, Stress Level, and Physical Activity

Authors: Yudia Mailani Putri, Martalena Purba, B. J. Istiti Kandarina

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Background: Obesity has been recognized as a global health problem. Individuals classified as overweight and obese are increasing at an alarming rate. This condition is associated with psychological and physiological problems. as a person reaches adulthood, somatic growth ceases. At this stage, the human body has developed fully, to a stable state. As the capital of Riau Province in Indonesia, Pekanbaru is dominated by Malay ethnic population habitually consuming cholesterol-rich fatty foods as a daily menu, a trigger to the onset of obesity resulting in high prevalence of degenerative diseases. Research objectives: The aim of this study is elaborating the relationship between high-fat consumption pattern, stress level, physical activity and the incidence of obesity in adult women in Pekanbaru city. Research Methods: Among the combined research methods applied in this study, the first stage is quantitative observational, analytical cross-sectional research design with adult women aged 20-40 living in Pekanbaru city. The sample consists of 200 women with BMI≥25. Sample data is processed with univariate, bivariate (correlation and simple linear regression) and multivariate (multiple linear regression) analysis. The second phase is qualitative descriptive study purposive sampling by in-depth interviews. six participants withdrew from the study. Results: According to the results of the bivariate analysis, there are relationships between the incidence of obesity and the pattern of high fat foods consumption (energy intake (p≤0.000; r = 0.536), protein intake (p≤0.000; r=0.307), fat intake (p≤0.000; r=0.416), carbohydrate intake (p≤0.000; r=0.430), frequency of fatty food consumption (p≤0.000; r=0.506) and frequency of viscera foods consumption (p≤0.000; r=0.535). There is a relationship between physical activity and incidence of obesity (p≤0.000; r=-0.631). However, there is no relationship between the level of stress (p=0.741; r=0.019-) and the incidence of obesity. Physical activity is a predominant factor in the incidence of obesity in adult women in Pekanbaru city. Conclusion: There are relationships between high-fat food consumption pattern, physical activity and the incidence of obesity in Pekanbaru city whereas physical activity is a predominant factor in the occurrence of obesity, supported by the unchangeable pattern of high-fat foods consumption.

Keywords: obesity, adult, high in fat, stress, physical activity, consumption pattern

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3656 Digitizing Masterpieces in Italian Museums: Techniques, Challenges and Consequences from Giotto to Caravaggio

Authors: Ginevra Addis

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The possibility of reproducing physical artifacts in a digital format is one of the opportunities offered by the technological advancements in information and communication most frequently promoted by museums. Indeed, the study and conservation of our cultural heritage have seen significant advancement due to the three-dimensional acquisition and modeling technology. A variety of laser scanning systems has been developed, based either on optical triangulation or on time-of-flight measurement, capable of producing digital 3D images of complex structures with high resolution and accuracy. It is necessary, however, to explore the challenges and opportunities that this practice brings within museums. The purpose of this paper is to understand what change is introduced by digital techniques in those museums that are hosting digital masterpieces. The methodology used will investigate three distinguished Italian exhibitions, related to the territory of Milan, trying to analyze the following issues about museum practices: 1) how digitizing art masterpieces increases the number of visitors; 2) what the need that calls for the digitization of artworks; 3) which techniques are most used; 4) what the setting is; 5) the consequences of a non-publication of hard copies of catalogues; 6) envision of these practices in the future. Findings will show how interconnection plays an important role in rebuilding a collection spread all over the world. Secondly how digital artwork duplication and extension of reality entail new forms of accessibility. Thirdly, that collection and preservation through digitization of images have both a social and educational mission. Fourthly, that convergence of the properties of different media (such as web, radio) is key to encourage people to get actively involved in digital exhibitions. The present analysis will suggest further research that should create museum models and interaction spaces that act as catalysts for innovation.

Keywords: digital masterpieces, education, interconnection, Italian museums, preservation

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3655 Impacts of Hydrologic and Topographic Changes on Water Regime Evolution of Poyang Lake, China

Authors: Feng Huang, Carlos G. Ochoa, Haitao Zhao

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Poyang Lake, the largest freshwater lake in China, is located at the middle-lower reaches of the Yangtze River basin. It has great value in socioeconomic development and is internationally recognized as an important lacustrine and wetland ecosystem with abundant biodiversity. Impacted by ongoing climate change and anthropogenic activities, especially the regulation of the Three Gorges Reservoir since 2003, Poyang Lake has experienced significant water regime evolution, resulting in challenges for the management of water resources and the environment. Quantifying the contribution of hydrologic and topographic changes to water regime alteration is necessary for policymakers to design effective adaption strategies. Long term hydrologic data were collected and the back-propagation neural networks were constructed to simulate the lake water level. The impacts of hydrologic and topographic changes were differentiated through scenario analysis that considered pre-impact and post-impact hydrologic and topographic scenarios. The lake water regime was characterized by hydrologic indicators that describe monthly water level fluctuations, hydrologic features during flood and drought seasons, and frequency and rate of hydrologic variations. The results revealed different contributions of hydrologic and topographic changes to different features of the lake water regime.Noticeable changes were that the water level declined dramatically during the period of reservoir impoundment, and the drought was enhanced during the dry season. The hydrologic and topographic changes exerted a synergistic effect or antagonistic effect on different lake water regime features. The findings provide scientific reference for lacustrine and wetland ecological protection associated with water regime alterations.

Keywords: back-propagation neural network, scenario analysis, water regime, Poyang Lake

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3654 Assessment of E-Learning Facilities in Open and Distance Learning and Information Need by Students

Authors: Sabo Elizabeth

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Electronic learning is increasingly popular learning approach in higher educational institutions due to vast growth of internet technology. This approach is important in human capital development. An investigation of open distance and e-learning facilities and information need by open and distance learning students was carried out in Jalingo, Nigeria. Structured questionnaires were administered to 70 registered ODL students of the NOUN. Information sourced from the respondents covered demographic, economic and institutional variables. Data collected for demographic variables were computed as frequency count and percentages. Assessment of the effectiveness of ODL facilities and information need among open and distance learning students was computed on a three or four point Likert Rating Scale. Findings indicated that there are more men compared to women. A large proportion of the respondents are married and there are more matured students in ODL compared to the youth. A high proportion of the ODL students obtained qualifications higher than the secondary school certificate. The proportion of computer literate ODL students was high, and large number of the students does not own a laptop computer. Inadequate e -books and reference materials, internet gadgets and inadequate books (hard copies) and reference material are factors that limit utilization of e-learning facilities in the study areas. Inadequate computer facilities and power back up caused inconveniences and delay in administering and use of e learning facilities. To a high extent, open and distance learning students needed information on university time table and schedule of activities, availability and access to books (hard and e-books) and reference materials. The respondents emphasized that contact with course coordinators via internet will provide a better learning and academic performance.

Keywords: open and distance learning, information required, electronic books, internet gadgets, Likert scale test

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3653 Product Architecture and Production Process of Battery Modules from Prismatic Lithium-Ion-Battery Cells

Authors: Achim Kampker, Heiner Hans Heimes, Nemanja Sarovic, Jan-Philip Ganser, Saskia Wessel, Christoph Lienemann

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The electrification of the power train is a fundamental technical transition in the automotive industry and poses a major challenge for established car companies. Providing the traction energy, requiring an ever greater amount of space within the car and having a high share of value-add the lithium-ion battery is a central component of the electric power train and a completely new component to car manufacturers at the same time. Being relatively new to the automotive industry, the current design of the product architecture and production process (including manufacturing and assembling processes) of lithium-ion battery modules do not allow for an easy and cost-efficient disassembly or product design change. Yet these two requirements will increase in importance with rising sales volumes of electric cars in the near future and need to be addressed for the electric car to be competitive with conventional power train systems. This paper focuses on the current product architecture and production process of common automotive battery modules from prismatic lithium-ion battery cells to derive impacts for a remanufacturing concept. The information necessary for this purpose were gathered by literature research, patent inquiries, industry expert interviews and first-hand experiences of the authors. On the basis of these results, the underlying causes for the design´s lack of remanufacturability and flexibility with regards to product design changes are examined. In all, this paper gives an extensive and detailed overview of the state of the art of the product architecture and production process of lithium-ion battery modules from prismatic battery cells, identifies its deficiencies and derives improvement measures.

Keywords: battery module, prismatic lithium-ion battery cell, product architecture, production process, remanufacturing, flexibility

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3652 Electrospun Conducting Polymer/Graphene Composite Nanofibers for Gas Sensing Applications

Authors: Aliaa M. S. Salem, Soliman I. El-Hout, Amira Gaber, Hassan Nageh

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Nowadays, the development of poisonous gas detectors is considered to be an urgent matter to secure human health and the environment from poisonous gases, in view of the fact that even a minimal amount of poisonous gas can be fatal. Of these concerns, various inorganic or organic sensing materials have been used. Among these are conducting polymers, have been used as the active material in the gassensorsdue to their low-cost,easy-controllable molding, good electrochemical properties including facile fabrication process, inherent physical properties, biocompatibility, and optical properties. Moreover, conducting polymer-based chemical sensors have an amazing advantage compared to the conventional one as structural diversity, facile functionalization, room temperature operation, and easy fabrication. However, the low selectivity and conductivity of conducting polymers motivated the doping of it with varied materials, especially graphene, to enhance the gas-sensing performance under ambient conditions. There were a number of approaches proposed for producing polymer/ graphene nanocomposites, including template-free self-assembly, hard physical template-guided synthesis, chemical, electrochemical, and electrospinning...etc. In this work, we aim to prepare a novel gas sensordepending on Electrospun nanofibers of conducting polymer/RGO composite that is the effective and efficient expectation of poisonous gases like ammonia, in different application areas such as environmental gas analysis, chemical-,automotive- and medical industries. Moreover, our ultimate objective is to maximize the sensing performance of the prepared sensor and to check its recovery properties.

Keywords: electro spinning process, conducting polymer, polyaniline, polypyrrole, polythiophene, graphene oxide, reduced graphene oxide, functionalized reduced graphene oxide, spin coating technique, gas sensors

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3651 Ultra-Reliable Low Latency V2X Communication for Express Way Using Multiuser Scheduling Algorithm

Authors: Vaishali D. Khairnar

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The main aim is to provide lower-latency and highly reliable communication facilities for vehicles in the automobile industry; vehicle-to-everything (V2X) communication basically intends to increase expressway road security and its effectiveness. The Ultra-Reliable Low-Latency Communications (URLLC) algorithm and cellular networks are applied in combination with Mobile Broadband (MBB). This is particularly used in express way safety-based driving applications. Expressway vehicle drivers (humans) will communicate in V2X systems using the sixth-generation (6G) communication systems which have very high-speed mobility features. As a result, we need to determine how to ensure reliable and consistent wireless communication links and improve the quality to increase channel gain, which is becoming a challenge that needs to be addressed. To overcome this challenge, we proposed a unique multi-user scheduling algorithm for ultra-massive multiple-input multiple-output (MIMO) systems using 6G. In wideband wireless network access in case of high traffic and also in medium traffic conditions, moreover offering quality-of-service (QoS) to distinct service groups with synchronized contemporaneous traffic on the highway like the Mumbai-Pune expressway becomes a critical problem. Opportunist MAC (OMAC) is a way of proposing communication across a wireless communication link that can change in space and time and might overcome the above-mentioned challenge. Therefore, a multi-user scheduling algorithm is proposed for MIMO systems using a cross-layered MAC protocol to achieve URLLC and high reliability in V2X communication.

Keywords: ultra-reliable low latency communications, vehicle-to-everything communication, multiple-input multiple-output systems, multi-user scheduling algorithm

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3650 The Construction Technology of Dryer Silo Materials to Grains Made from Webbing Bamboo: A Drying Technology Solutions to Empowerment Farmers in Yogyakarta, Indonesia

Authors: Nursigit Bintoro, Abadi Barus, Catur Setyo Dedi Pamungkas

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Indonesia is an agrarian country have almost population work as farmers. One of the popular agriculture commodity in Indonesia is paddy and corn. Production of paddy and corn are increased, but not balanced to the development of appropriate technology to farmers. Methods of drying applied with farmers still using sunshine. Drying by this method has some drawbacks, such as differences moisture content of corn grains, time used to dry around 3 days, and less quality of the products obtained. Beside it, the method of drying by using sunshine can’t do when the rainy season arrives. On this season the product obtained has less quality. One solution to the above problems is to create a dryer with simple technology. That technology is made silo dryer from webbing bamboo and wood. This technology is applicable to be applied to farmers' groups as well as the creation technology is quite cheap. The experiment material used in this research will be obtained from the corn grains. The equipment used are woven bamboo with a height of 3 meters and have capacity of up to 900 kgs as a silo, gas, burner, blower, bucket elevators, thermocouple, Arduino microcontroller 2560. This tools automatically records all the data of temperature and relative humidity. During on drying, each 30 minutes take 9 sample for measuring moisture content with moisture meter. By using this technology, farmers can save time, energy, and cost to the drying their agriculture product. In addition, by using this technology have good quality moisture content of grains and have a longer shelf life because the temperature when the heating process is controlled. Therefore, this technology is applicable to be applied to the public because the materials used to make the dryer easier to find, cheaper, and manufacture of the dryer made simple with good quality.

Keywords: grains, dryer, moisture content, appropriate technology

Procedia PDF Downloads 344
3649 Effectiveness of Active Learning in Social Science Courses at Japanese Universities

Authors: Kumiko Inagaki

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In recent, years, Japanese universities have begun to face a dilemma: more than half of all high school graduates go on to attend an institution of higher learning, overwhelming Japanese universities accustomed to small student bodies. These universities have been forced to embrace qualitative changes to accommodate the increased number and diversity of students who enter their establishments, students who differ in their motivations for learning, their levels of eagerness to learn, and their perspectives on the future. One of these changes is an increase in awareness among Japanese educators of the importance of active learning, which deepens students’ understanding of course material through a range of activities, including writing, speaking, thinking, and presenting, in addition to conventional “passive learning” methods such as listening to a one-way lecture.  The purpose of this study is to examine the effectiveness of the teaching method adapted to improve active learning. A teaching method designed to promote active learning was implemented in a social science course at one of the most popular universities in Japan. A questionnaire using a five-point response format was given to students in 2,305 courses throughout the university to evaluate the effectiveness of the method based on the following measures: ① the ratio of students who were motivated to attend the classes, ② the rate at which students learned new information, and ③ the teaching method adopted in the classes. The results of this study show that the percentage of students who attended the active learning course eagerly, and the rate of new knowledge acquired through the course, both exceeded the average for the university, the department, and the subject area of social science. In addition, there are strong correlations between teaching method and student motivation and between teaching method and knowledge acquisition rate. These results indicate that the active learning teaching method was effectively implemented and that it may improve student eagerness to attend class and motivation to learn.

Keywords: active learning, Japanese university, teaching method, university education

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3648 First Principle-Based Dft and Microkinetic Simulation of Co-Conversion of Carbon Dioxide and Methane on Single Iridium Atom Doped Hematite with Surface Oxygen Defect

Authors: Kefale W. Yizengaw, Delele Worku Ayele, Jyh-Chiang Jiang

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The catalytic co-conversion of CO₂ and CH₄ to value-added compounds has become one of the promising approaches to addressing global climate change by having valuable fossil fuels. Thedirect co-conversion of CO₂ and CH₄ to value-added compounds is attractive but tremendously challenging because of both molecules' thermodynamic stability and kinetic inertness. In the present study, a single iridium atom doped and a single oxygen atom defect hematite (110)surface model catalyst, which can comprehend direct C–O coupling based on simultaneous activation of CO2 and CH4 was studied using density functional theory plus U (DFT + U)calculations. The presence of dual active sites on the Ir/Fe₂O₃(110)-OV surface catalyst enablesCO₂ activation on the Ir site and CH₄ activation at the defect site. The electron analysis for the theco-adsorption of CO₂ and CH₄ deals with the electron redistribution on the surface and clearly shows the synergistic effect for simultaneous CO₂ and CH₄ activation on Ir/α- Fe₂O₃(110)-OVsurface. The microkinetic analysis shows that the dissociation of CH4 to CH3 * and H* plays an excellent role in the C–O coupling. The coverage analysis for the intermediate products of the microkinetic simulation results indicates that C–O coupling is the reaction limiting step. Finally, after the CH₃O* intermediate product species is produced, the radical hydrogen species spontaneously diffuse to the CH3O* intermediate product to form methanol at around 490 [K]. The present work provides mechanistic and kinetic insights into the direct C–O coupling of CO₂and CH₄, which could help design more-efficient catalysts.

Keywords: co-conversion, C–O coupling, doping, oxygen vacancy, microkinetic

Procedia PDF Downloads 103
3647 Looking beyond Lynch's Image of a City

Authors: Sandhya Rao

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Kevin Lynch’s Theory on Imeageability, let on explore a city in terms of five elements, Nodes, Paths, Edges, landmarks and Districts. What happens when we try to record the same data in an Indian context? What happens when we apply the same theory of Imageability to a complex shifting urban pattern of the Indian cities and how can we as Urban Designers demonstrate our role in the image building ordeal of these cities? The organizational patterns formed through mental images, of an Indian city is often diverse and intangible. It is also multi layered and temporary in terms of the spirit of the place. The pattern of images formed is loaded with associative meaning and intrinsically linked with the history and socio-cultural dominance of the place. The embedded memory of a place in one’s mind often plays an even more important role while formulating these images. Thus while deriving an image of a city one is often confused or finds the result chaotic. The images formed due to its complexity are further difficult to represent using a single medium. Under such a scenario it’s difficult to derive an output of an image constructed as well as make design interventions to enhance the legibility of a place. However, there can be a combination of tools and methods that allows one to record the key elements of a place through time, space and one’s user interface with the place. There has to be a clear understanding of the participant groups of a place and their time and period of engagement with the place as well. How we can translate the result obtained into a design intervention at the end, is the main of the research. Could a multi-faceted cognitive mapping be an answer to this or could it be a very transient mapping method which can change over time, place and person. How does the context influence the process of image building in one’s mind? These are the key questions that this research will aim to answer.

Keywords: imageability, organizational patterns, legibility, cognitive mapping

Procedia PDF Downloads 298
3646 Characterization of Biogenic Silver Nanoparticles by Salvadora persica Leaves Extract and its Application Against Some MDR Pathogens E. Coli and S. Aureus

Authors: Mudawi M. Nour

Abstract:

Background: Now a days, the multidisciplinary scientific research conception in the field of nanotechnology has witnessed development with regard to the numerous applications and synthesis of nanomaterials. Objective: The current investigation has been conducted with the main focus on the green synthesis of silver nanoparticles from the leaves of Salvadora persica and its antibacterial activity against MDR pathogens E. coli and S. aureus. Methodology: Silver nanoparticles (AgNPs) were prepared after addition of aqueous extract of Salvadora persica leaves. The UV-Vis spectrophotometer, Transmission Electron Microscopy (TEM), zeta potential and Scanning Electron Microscopy (SEM) were employed to detect the particle size and morphology, besides Fourier transform infra-red spectrometer (FTIR) analysis was performed to determine the capping and stabilizing agents in the extract. Antibacterial assay for the biogenic AgNPs was conducted against E. coli and S. aureus. Results: Color change of the mixture from yellow to dark brown is the first indication to AgNPs formation. Furthermore, 420 nm was the peak value for UV-Vis spectroscopy absorption of the mixture. Besides, TEM and SEM micrographs showed wide variability in the diameter of smaller NPs aggregated together with spherical shapes, and zeta sizer showed about 153.3 nm as an average size of nanoparticles. Microbial suppression was noticed for the tested microorganisms. Furthermore, with the help of FTIR analysis, the biomolecules that act as capping and stabilizing agents of AgNPs are proteins and phenols present in the plant extract. Conclusion: Salvadora persica leaves extract act as a reducing and stabilizing agent for the synthesis of AgNPs, keeping its ability to suppress the MDR pathogen.

Keywords: green synthesis, FTIR, MDR pathogen, salvadora persica

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3645 Potentiometric Determination of Moxifloxacin in Some Pharmaceutical Formulation Using PVC Membrane Sensors

Authors: M. M. Hefnawy, A. M. A. Homoda, M. A. Abounassif, A. M. Alanazia, A. Al-Majed, Gamal A. E. Mostafa

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PVC membrane sensors using different approach e.g. ion-pair, ionophore, and Schiff-base has been used as testing membrane sensor. Analytical applications of membrane sensors for direct measurement of variety of different ions in complex biological and environmental sample are reported. The most important step of such PVC membrane sensor is the sensing active material. The potentiometric sensors have some outstanding advantages including simple design, operation, wide linear dynamic range, relative fast response time, and rotational selectivity. The analytical applications of these techniques to pharmaceutical compounds in dosage forms are also discussed. The construction and electrochemical response characteristics of Poly (vinyl chloride) membrane sensors for moxifloxacin HCl (MOX) are described. The sensing membranes incorporate ion association complexes of moxifloxacin cation and sodium tetraphenyl borate (NaTPB) (sensor 1), phosphomolybdic acid (PMA) (sensor 2) or phosphotungstic acid (PTA) (sensor 3) as electroactive materials. The sensors display a fast, stable and near-Nernstian response over a relative wide moxifloxacin concentration range (1 ×10-2-4.0×10-6, 1 × 10-2-5.0×10-6, 1 × 10-2-5.0×10-6 M), with detection limits of 3×10-6, 4×10-6 and 4.0×10-6 M for sensor 1, 2 and 3, respectively over a pH range of 6.0-9.0. The sensors show good discrimination of moxifloxacin from several inorganic and organic compounds. The direct determination of 400 µg/ml of moxifloxacin show an average recovery of 98.5, 99.1 and 98.6 % and a mean relative standard deviation of 1.8, 1.6 and 1.8% for sensors 1, 2, and 3 respectively. The proposed sensors have been applied for direct determination of moxifloxacin in some pharmaceutical preparations. The results obtained by determination of moxifloxacin in tablets using the proposed sensors are comparable favorably with those obtained using the US Pharmacopeia method. The sensors have been used as indicator electrodes for potentiometric titration of moxifloxacin.

Keywords: potentiometry, PVC, membrane sensors, ion-pair, ionophore, schiff-base, moxifloxacin HCl, sodium tetraphenyl borate, phosphomolybdic acid, phosphotungstic acid

Procedia PDF Downloads 425
3644 Determinants of Quality of Life and Mental Health in Medical Students During Two Years Observation

Authors: Szymon Szemik, Małgorzata Kowalska

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Objective: Medical students experience numerous demands during the education process, determining their quality of life (QoL) and health status. POLLEK (POLski LEKarz, eng. Polish Physician) study aims to identify and evaluate the quality of life, mental health status, and ever-recognized chronic diseases by simultaneously assessing their determinants in Polish medical students during long-term observation. Material and Methods: The POLLEK is the follow-up cohort study conducted among medical students at the Medical University of Silesia in Katowice. Students were followed during two observation periods: in their first year of studies, the academic year 2021/2022 (T1), and in their second year, the academic year 2022/2023 (T2). Results: The total number of participants in the first year of observation (T1) was 427 while in the second year (T2) was 335. Obtained results confirmed that the QoL score significantly decreased in their second year of studies mainly in the somatic and psychological domains. Moreover, we observed a significant increase in self-declared scoring of somatic symptoms year by year (from M=4.75 at T1 to M=8.06 at T2, p<0.001) in the GHQ-28 questionnaire survey. The determinants of QoL domains common to T1 and T2 remained self-declared health status, frequency of physical activity, and current financial situation. In the first year of evaluation, 56 students (13.10%) were overweight or obese, and 52 (15.8%) in the second. Regardless of the academic year, the increased risk of being overweight or obese was significantly associated with dissatisfaction with personal health, financial deficiencies, and a diet abundant in meat consumption. Conclusions: The QoL in medical students and selected determinants of their health status deteriorated during the observation period. Our findings suggest that medical schools should actively promote the activity needed to achieve a balance between schoolwork and the personal life of medical students from the beginning of university study.

Keywords: quality of life, mental health, medical students, follow-up study

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3643 Attitudes of Secondary School Students towards Science and Technical Education in Yauri Metropolis Kebbi State, Nigeria

Authors: Ibrahim Alhassan Libata

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This study was carried out to assess attitude of secondary school students towards science and technical education in Yauri metropolis, Kebbi State, Nigeria. The population of the study was 200. Proportionate random sampling method was used in selecting 132 as sample size. Science and technical education is the most powerful forces for change in the world today, and students who hope to have a hand in shaping a better future must participate for their advancements. Four Null hypotheses were generated to guide the conduct of the study, questionnaire was the only instrument used in the study; the instrument was subjected to test-retest reliability. The reliability index of the instrument was 0.69. Overall scores of the Students were analyzed and a mean score was determined, the mean score of students was 85. There were no significant differences between the attitudes of male and female students towards science and technical education. The results also revealed that there was significant difference between the attitude of boding and day school students towards science and technical education, personality constraints of students is one factor militating against the participation of students in science and technical education, socio-economic status of the parents over the years have been the dominant factor of student’s inadequate representation in the field of science and technical education. Based on the findings of this study, the researcher recommended that teachers should motivate students, which they can do through their teaching styles and by showing them the relevance of the learning topics to their everyday lives. Government and the school management should create the learning environment that helps motivate students not only to come to classes but also want to learn and enjoy learning science and technical education, establishment of more Science and Technical Colleges education, more Public enlightenment campaigns to motivate parents and the entire community to support their children in studying science and technical education.

Keywords: attitude, students, science, Yauri

Procedia PDF Downloads 233
3642 Characterization of Electrical Transport across Ultra-Thin SrTiO₃ and BaTiO₃ Barriers in Tunnel Junctions

Authors: Henry Navarro, Martin Sirena, Nestor Haberkorn

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We report the electrical transport through voltage-current curves (I-V) in tunnels junction GdBa₂Cu₃O₇-d/ insulator/ GdBa₂Cu₃O₇-d, and Nb/insulator/ GdBa₂Cu₃O₇-d is analyzed using a conducting atomic force microscope (CAFM) at room temperature. The measurements were obtained on tunnel junctions with different areas (900 μm², 400 μm² and 100 μm²). Trilayers with GdBa₂Cu₃O₇-d (GBCO) as the bottom electrode, SrTiO₃ (STO) or BaTiO₃ (BTO) as the insulator barrier (thicknesses between 1.6 nm and 4 nm), and GBCO or Nb as the top electrode were grown by DC sputtering on (100) SrTiO₃ substrates. For STO and BTO barriers, asymmetric IV curves at positive and negative polarization can be obtained using electrodes with different work function. The main difference is that the BTO is a ferroelectric material, while in the STO the ferroelectricity can be produced by stress or deformation at the interfaces. In addition, hysteretic IV curves are obtained for BTO barriers, which can be ascribed to a combined effect of the FE reversal switching polarization and an oxygen vacancy migration. For GBCO/ BTO/ GBCO heterostructures, the IV curves correspond to that expected for asymmetric interfaces, which indicates that the disorder affects differently the properties at the bottom and top interfaces. Our results show the role of the interface disorder on the electrical transport of conducting/ insulator/ conduction heterostructures, which is relevant for different applications, going from resistive switching memories (at room temperature) to Josephson junctions (at low temperatures). The superconducting transition of the GBCO electrode was characterized by electrical transport using the 4-prong configuration with low density of topological defects and with Tc over liquid N₂ can be obtained for thicknesses of 16 nm, our results demonstrate that GBCO films with an average root-mean-square (RMS) smaller than 1 nm and areas (up 100 um²) free of 3-D topological defects can be obtained.

Keywords: thin film, sputtering, conductive atomic force microscopy, tunnel junctions

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3641 Creating an Enabling Learning Environment for Learners with Visual Impairments Inlesotho Rural Schools by Using Asset-Based Approaches

Authors: Mamochana, A. Ramatea, Fumane, P. Khanare

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Enabling the learning environment is a significant and adaptive technique necessary to navigate learners’ educational challenges. However, research has indicated that quality provision of education in the environments that are enabling, especially to learners with visual impairments (LVIs, hereafter) in rural schools, remain an ongoing challenge globally. Hence, LVIs often have a lower level of academic performance as compared to their peers. To balance this gap and fulfill learners'fundamentalhuman rights¬ of receiving an equal quality education, appropriate measures and structures that make enabling learning environment a better place to learn must be better understood. This paper, therefore, intends to find possible means that rural schools of Lesotho can employ to make the learning environment for LVIs enabling. The present study aims to determine suitable assets that can be drawn to make the learning environment for LVIs enabling. The study is also informed by the transformative paradigm and situated within a qualitative research approach. Data were generated through focus group discussions with twelve teachers who were purposefully selected from two rural primary schools in Lesotho. The generated data were then analyzed thematically using Braun and Clarke's six-phase framework. The findings of the study indicated that participating teachers do have an understanding that rural schools boast of assets (existing and hidden) that have a positive influence in responding to the special educational needs of LVIs. However, the participants also admitted that although their schools boast of assets, they still experience limited knowledge about the use of the existing assets and thus, realized a need for improved collaboration, involvement of the existing assets, and enhancement of academic resources to make LVIs’ learning environment enabling. The findings of this study highlight the significance of the effective use of assets. Additionally, coincides with literature that shows recognizing and tapping into the existing assets enable learning for LVIs. In conclusion, the participants in the current study indicated that for LVIs’ learning environment to be enabling, there has to be sufficient use of the existing assets. The researchers, therefore, recommend that the appropriate use of assets is good, but may not be sufficient if the existing assets are not adequately managed. Hence,VILs experience a vicious cycle of vulnerability. It was thus, recommended that adequate use of assets and teachers' engagement as active assets should always be considered to make the learning environment a better place for LVIs to learan in the future

Keywords: assets, enabling learning environment, rural schools, learners with visual impairments

Procedia PDF Downloads 88
3640 An Energy-Balanced Clustering Method on Wireless Sensor Networks

Authors: Yu-Ting Tsai, Chiun-Chieh Hsu, Yu-Chun Chu

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In recent years, due to the development of wireless network technology, many researchers have devoted to the study of wireless sensor networks. The applications of wireless sensor network mainly use the sensor nodes to collect the required information, and send the information back to the users. Since the sensed area is difficult to reach, there are many restrictions on the design of the sensor nodes, where the most important restriction is the limited energy of sensor nodes. Because of the limited energy, researchers proposed a number of ways to reduce energy consumption and balance the load of sensor nodes in order to increase the network lifetime. In this paper, we proposed the Energy-Balanced Clustering method with Auxiliary Members on Wireless Sensor Networks(EBCAM)based on the cluster routing. The main purpose is to balance the energy consumption on the sensed area and average the distribution of dead nodes in order to avoid excessive energy consumption because of the increasing in transmission distance. In addition, we use the residual energy and average energy consumption of the nodes within the cluster to choose the cluster heads, use the multi hop transmission method to deliver the data, and dynamically adjust the transmission radius according to the load conditions. Finally, we use the auxiliary cluster members to change the delivering path according to the residual energy of the cluster head in order to its load. Finally, we compare the proposed method with the related algorithms via simulated experiments and then analyze the results. It reveals that the proposed method outperforms other algorithms in the numbers of used rounds and the average energy consumption.

Keywords: auxiliary nodes, cluster, load balance, routing algorithm, wireless sensor network

Procedia PDF Downloads 265
3639 Effect of Rice Cultivars and Water Regimes Application as Mitigation Strategy for Greenhouse Gases in Paddy Fields

Authors: Mthiyane Pretty, Mitsui Toshiake, Aycan Murat, Nagano Hirohiko

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Methane (CH₄) is one of the most dangerous greenhouse gases (GHG) emitted into the atmosphere by terrestrial ecosystems, with a global warming potential (GWP) 25-34 times that of CO2 on a centennial scale. Paddy rice cultivations are a major source of methane emission and is the major driving force for climate change. Thus, it is necessary to find out GHG emissions mitigation strategies from rice cultivation. A study was conducted at Niigata University. And the prime objective of this research was to determine the effects of rice varieties CH4 lowland (NU1, YNU, Nipponbare, Koshihikari) and upland (Norin 1, Norin 24, Hitachihatamochi) japonica rice varieties using different growth media which was paddy field soil and artificial soil. The treatments were laid out in a split plot design. The soil moisture was kept at 40-50% and 70%, respectively. The CH₄ emission rates were determined by collecting air samples using the closed chamber technique and measuring CH₄ concentrations using a gas chromatograph. CH₄ emission rates varied with the growth, growth media type and development of the rice varieties. The soil moisture was monitored at a soil depth of 5–10 cm with an HydraGO portable soil sensor system every three days for each pot, and temperatures were be recorded by a sensitive thermometer. The lowest cumulative CH4 emission rate was observed in Norin 24, particularly under 40 to 50% soil moisture. Across the rice genotypes, 40-50% significantly reduced the cumulative CH4 , followed by irrigation of 70% soil moisture. During the tillering stage, no significant variation in tillering and plant height was observed between and 70% soil moisture. This study suggests that the cultivation of Norin 24 and Norin 1 under 70% soil irrigation could be effective at reducing the CH4 in rice fields.

Keywords: methane, paddy fields, rice varieties, soil moisture

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3638 Structural Property and Mechanical Behavior of Polypropylene–Elemental Sulfur (S8) Composites: Effect of Sulfur Loading

Authors: S. Vijay Kumar, Kishore K. Jena, Saeed M. Alhassan

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Elemental sulfur is currently produced on the level of 70 million tons annually by petroleum refining, majority of which is used in the production of sulfuric acid, fertilizer and other chemicals. Still, over 6 million tons of elemental sulfur is generated in excess, which creates exciting opportunities to develop new chemistry to utilize sulfur as a feedstock for polymers. Development of new polymer composite materials using sulfur is not widely explored and remains an important challenge in the field. Polymer nanocomposites prepared by carbon nanotube, graphene, silica and other nanomaterials were well established. However, utilization of sulfur as filler in the polymer matrix could be an interesting study. This work is to presents the possibility of utilizing elemental sulfur as reinforcing fillers in the polymer matrix. In this study we attempted to prepare polypropylene/sulfur nanocomposite. The physical, mechanical and morphological properties of the newly developed composites were studied according to the sulfur loading. In the sample preparation, four levels of elemental sulfur loading (5, 10, 20 and 30 wt. %) were designed. Composites were prepared by the melt mixing process by using laboratory scale mini twin screw extruder at 180°C for 15 min. The reaction time and temperature were maintained constant for all prepared composites. The structure and crystallization behavior of composites was investigated by Raman, FTIR, XRD and DSC analysis. It was observed that sulfur interfere with the crystalline arrangement of polypropylene and depresses the crystallization, which affects the melting point, mechanical and thermal stability. In the tensile test, one level of test temperature (room temperature) and crosshead speed (10 mm/min) was designed. Tensile strengths and tensile modulus of the composites were slightly decreased with increasing in filler loading, however, percentage of elongation improved by more than 350% compared to neat polypropylene. The effect of sulfur on the morphology of polypropylene was studied with TEM and SEM techniques. Microscope analysis revels that sulfur is homogeneously dispersed in polymer matrix and behaves as single phase arrangement in the polymer. The maximum elongation for the polypropylene can be achieved by adjusting the sulfur loading in the polymer. This study reviles the possibility of using elemental sulfur as a solid plasticizer in the polypropylene matrix.

Keywords: crystallization, elemental sulfur, morphology, thermo-mechanical properties, polypropylene, polymer nanocomposites

Procedia PDF Downloads 330