Search results for: contemporary conditions

Authors: Ece Kök Yetimoğlu, Soner Çubuk, Neşe Taşci, M. Vezir Kahraman

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Lead(II) is one of the most toxic environmental pollutants in the world, due to its high toxicity and non-biodegradability. Lead exposure causes severe risks to human health such as central brain damages, convulsions, kidney damages, and even death. To determine lead(II) in environmental or biological samples, scientists use atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICPMS), fluorescence spectrometry and electrochemical techniques. Among these systems the fluorescence spectrometry and fluorescent chemical sensors have attracted considerable attention because of their good selectivity and high sensitivity. The fluorescent polymers usually contain covalently bonded fluorophores. In this study imidazole based UV cured polymeric film was prepared and designed to act as a fluorescence chemo sensor for lead (II) analysis. The optimum conditions such as influence of pH value and time on the fluorescence intensity of the sensor have also been investigated. The sensor was highly sensitive with a detection limit as low as 1.87 × 10−8 mol L-1 and it was successful in the determination of Pb(II) in water samples.

Keywords: fluorescence, lead(II), photopolymerization, polymeric sensor

Procedia PDF Downloads 668

Authors: Nathalie Gagnon, Andréanne Gagné, Julie Courcy

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Quebec's vocational education teachers experience an atypical induction process into the workplace and thus face unique challenges. In contrast to elementary and high school teachers, who must undergo initial teacher training in order to access the profession, vocational education teachers, in most cases, are hired based on their professional expertise in the trade they are teaching, without prior pedagogical training. In addition to creating significant stress, which does not foster the acquisition of teaching roles and skills, this approach also forces recruits into a particular posture during their practical training: that of juggling their dual identities as teacher and trainee simultaneously. Recruits are supported by Cooperating Teachers (CPs) who, as experienced educators, take a critical and constructive look at their practices, observe them in the classroom, give them constructive feedback, and encourage them in their reflective practice. Thus, the vocational setting CP also assumes a distinctive posture and role due to the characteristics of the trainees they support. Although it is recognized that preparation, training, and supervision of CPs are essential factors in improving the support provided to trainees, there is little research about how CPs develop their support skills, and very little research focuses on the distinct posture they occupy. However, in order for them to be properly equipped for the important role they play in recruits’ practical training, it is vital to know more about their experience. An individual’s competencies cannot be studied without first examining what characterizes their experience, how they experience any given situation on cognitive, emotional, and motivational levels, in addition to how they act and react in situ. Depending on its nature, the experience will or will not promote the development of a specific competency. The research from which this communication originates focuses on describing the overall experience of vocational education CP in an effort to better understand the mechanisms linked to the development of their mentoring competencies. Experience and competence were, therefore, the two main theoretical concepts leading the research. As per methodology choices, case study methods were used since it proves to be adequate to describe in a rich and detailed way contemporary phenomena within contexts of life. The set of data used was collected from semi-structured interviews conducted with 15 vocational education CP in Quebec (Canada), followed by the use of a data-driven semi-inductive analysis approach to let the categories emerge organically. Focusing on the development needs of vocational education CP to improve their mentoring skills, this paper presents the results of our research, namely the importance of adequate training, better support offered by university supervisors, greater recognition of their role, and specific time slots dedicated to trainee support. The knowledge resulting from this research could improve the quality of support for trainee teachers in vocational education settings and to a more successful induction into the workplace. This communication also presents recommendations regarding the development of training systems that meet the specific needs of vocational education CP.

Keywords: development of competencies, cooperating teacher, mentoring trainee teacher, practical training, vocational education

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Authors: Kenza Maher, Yahya Zakaria, Noora S. Al-Jaidah

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Temperature is a critical parameter for lithium-ion battery performance, life, and safety. In this study, four commercially available 18650 lithium-ion cells from four different manufacturers are subjected to accelerated cycle aging for up to 500 cycles at two different temperatures (25°C and 45°C). The cells are also calendar-aged at the same temperatures in both charged and discharged states for 6 months to investigate the effect of aging and temperature on capacity fade and state of health. The results showed that all battery cells demonstrated good cyclability and had a good state of health at both temperatures. However, the capacity loss and state of health of these cells are found to be dependent on the cell chemistry and aging conditions, including temperature. Specifically, the capacity loss is found to be higher at the higher aging temperature, indicating the significant impact of temperature on the aging of lithium-ion batteries.

Keywords: lithium-ion battery, aging mechanisms, cycle aging, calendar aging.

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Authors: Aniket Aaba Kadam, Manish Mangesh Panchal, Roushan Ashit Sharma

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This project focuses on the design and development of a lab-scale hybrid rocket motor to accurately determine the regression rate of a fuel/oxidizer combination consisting of solid paraffin and gaseous oxygen (GOX). Hybrid motors offer the advantage of on-demand thrust control over both solid and liquid systems in certain applications. The thermodynamic properties of the propellant combination were calculated using NASA CEA at different chamber pressures and corresponding O/F values to determine initial operating conditions with suitable peak temperatures and optimal O/F values. The project also includes the design of the injector orifice and the determination of the final design configurations of the motor casing, pressure control setup, and valve configuration. This research will be valuable in advancing the understanding of paraffin-based propulsion and improving the performance of hybrid rocket motors.

Keywords: hybrid rocket, NASA CEA, injector, thrust control

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Authors: M. Nafis Alfarizi, Dinda A. Utami, Arif Hidayat

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Biodiesel is one solution to overcome the use of petroleum fuels. Many alternative feedstocks that can be used among which canola oil. The purpose of this study was to determine the ability of canola oil and KOH for the trans-esterification reaction in biodiesel production. Canola oil has a very high purity that can be used as an alternative feedstock for biodiesel production and expected it will be produced biodiesel with excellent quality. In this case of study, we used trans-esterification process wherein the triglyceride is reacted with an alcohol with KOH as a catalyst, and it will produce biodiesel and glycerol as byproduct and we choose trans-esterification process because canola oil has a 0,445% FFA content. The variables studied in this research include the comparison of canola oil and methanol, temperature, time, and the percent of catalyst used. In this study the method of analysis we use GCMS and FTIR to know what the characteristic in canola oil. Development of canola oil seems to be the perfect solution to produce high-quality biodiesel. The reaction conditions resulted in 97.87% -w methyl ester (biodiesel) product by using a 0.5% wt KOH catalyst with canola and methanol ratio 1:8 at 60°C.

Keywords: biodiesel, canola oil, KOH, trans-esterification

Procedia PDF Downloads 254

Authors: Yuchen Niu, Liang Zhao, Fangfang Xie, Weiyu Liu

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In the past decades, rapid urbanization in China has significantly promoted economic growth and caused a large number of environmental problems. In consideration of land resources shortage, high-density cities will become a common phenomenon in the future. How to improve the living environment under high density is a new challenge. Shenzhen is a typical high-density city, but also the forefront of China's development and reform area. This study selects 9 urban parks with different natural attributes in Shenzhen and explores the relationship of natural, economic, and social conditions within the service scope. Based on correlation analysis and system analysis, the results indicate that improvement of park design and management methods contribute to obtaining higher ecological value and promote economic and social development.

Keywords: correlation analysis, high-density city, park improvement, urban green spaces

Procedia PDF Downloads 121

Authors: Luísa P. Cruz-Lopes, Liliana Rodrigues, Idalina Domingos, José Ferreira, Luís Teixeira de Lemos, Bruno Esteves

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Currently, the polyurethanes industry is dependent on fossil resources to obtain their basic raw materials (polyols and isocyanate), as these are obtained from petroleum products. The aim of this work was to use biopolyols from liquefied Pseudotsuga (Pseudotsuga menziesii) and Turkey oak (Quercus cerris) barks for the production of polyurethane foams and optimize the process. Liquefaction was done with glycerol catalyzed by KOH. Foams were produced following different formulations and using biopolyols from both barks. Subsequently, the foams were characterized according to their mechanical properties and the reaction of the foam formation was monitored by FTIR-ATR. The results show that it is possible to produce polyurethane foams using bio-based polyols and the liquefaction conditions are very important because they influence the characteristics of biopolyols and, consequently the characteristics of the foams. However, the process has to be further optimized so that it can obtain better quality foams.

Keywords: Bio-based polyol, mechanical tests, polyurethane foam, Pseudotsuga bark, renewable resources, Turkey oak bark

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Authors: Nicola Harrison

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Familial childhood sexual abuse (FCSA) prevalence rates in Aotearoa, New Zealand, are amongst the highest globally, particularly in indigenous communities. However, such statistics seem incongruent with indigenous paradigms of unity, care, and connection. The inability of policymakers and mainstream service providers to acknowledge the direct links between the social contexts created by colonisation for indigenous families in Aotearoa and intergenerational FCSA has meant there has been little meaningful success in combatting this significant social problem. This research traces the conditions of intergenerational FCSA to the systemic inequalities created by colonization. Kaupapa Māori methodologies were applied to this qualitative piece of empirical research wherein 17 indigenous contributors shared their stories of FCSA. From these stories and existing literature, we can identify how the machinations of colonisation are mirrored by techniques used to perpetrate abuse. Once identified, we are then able to recommend actions for halting FCSA for future generations.

Keywords: indigenity, family violence, childhood sexual abuse, colonization

Procedia PDF Downloads 121

Authors: Arunporn Itharat, Srisopa Ruangnoo, Pakakrong Thongdeeying

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The rhizomes of Dioscorea membranacea (DM) has long been used in Thai Traditional medicine to treat cancer and inflammatory conditions such as rheumatism. The objective of this study was to investigate anti-inflammatory activity by determining the inhibitory effect on LPS-induced TNF-α from RAW264.7 cells of crude extracts and pure isolated compounds from DM. Three known dihydrophenantrene compounds were isolated by a bioassay guided isolation method from DM ethanolic extract [2,4 dimethoxy-5,6-dihydroxy-9,10-dihydrophenanthrene (1) and 5-hydroxy-2,4,6-trimethoxy-9,10-dihydrophenanthrene(2) and 5,6,2 -trihydroxy 3,4-methoxy, 9,10- dihydrophenanthrene (3)]. 1 showed the highest inhibitory effect on PGE2, followed by 3 and 1 (IC50 = 2.26, 4.97 and >20 μg/ml or 8.31,17.25 and > 20 µM respectively). These findings suggest that this plant showed anti-inflamatory effects by displaying an inhibitory effect on TNF-α release, hence, this result supports the usage of Thai traditional medicine to treat inflammation related diseases.

Keywords: Dioscorea membranacea, anti-inflammatory activity, TNF-Alpha , dihidrophenantrene compound

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Authors: N. Manjunatha, K. T. Rangswamy, N. Nagaraju, H. A. Prameela, P. Rudraswamy, M. Krishnareddy

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The identification of virus in cowpea especially potyviruses is confusing. Even though there are several studies on viruses causing diseases in cowpea, difficult to distinguish based on symptoms and serological detection. The differentiation of potyviruses considering as a constraint, the present study is initiated for molecular characterization, host plant resistance and epidemiology of the BCMV infecting cowpea. The etiological agent causing cowpea mosaic was identified as Bean Common Mosaic Virus (BCMV) on the basis of RT-PCR and electron microscopy. An approximately 750bp PCR product corresponding to coat protein (CP) region of the virus and the presence of long flexuous filamentous particles measuring about 952 nm in size typical to genus potyvirus were observed under electron microscope. The characterized virus isolate genome had 10054 nucleotides, excluding the 3’ terminal poly (A) tail. Comparison of polyprotein of the virus with other potyviruses showed similar genome organization with 9 cleavage sites resulted in 10 functional proteins. The pairwise sequence comparison of individual genes, P1 showed most divergent, but CP gene was less divergent at nucleotide and amino acid level. A phylogenetic tree constructed based on multiple sequence alignments of the polyprotein nucleotide and amino acid sequences of cowpea BCMV and potyviruses showed virus is closely related to BCMV-HB. Whereas, Soybean variant of china (KJ807806) and NL1 isolate (AY112735) showed 93.8 % (5’UTR) and 94.9 % (3’UTR) homology respectively with other BCMV isolates. This virus transmitted to different leguminous plant species and produced systemic symptoms under greenhouse conditions. Out of 100 cowpea genotypes screened, three genotypes viz., IC 8966, V 5 and IC 202806 showed immune reaction in both field and greenhouse conditions. Single marker analysis (SMA) was revealed out of 4 SSR markers linked to BCMV resistance, M135 marker explains 28.2 % of phenotypic variation (R2) and Polymorphic information content (PIC) value of these markers was ranged from 0.23 to 0.37. The correlation and regression analysis showed rainfall, and minimum temperature had significant negative impact and strong relationship with aphid population, whereas weak correlation was observed with disease incidence. Path coefficient analysis revealed most of the weather parameters exerted their indirect contributions to the aphid population and disease incidence except minimum temperature. This study helps to identify specific gaps in knowledge for researchers who may wish to further analyse the science behind complex interactions between vector-virus and host in relation to the environment. The resistant genotypes identified are could be effectively used in resistance breeding programme.

Keywords: cowpea, epidemiology, genotypes, virus

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Authors: Kerem Can Dizdar, Semih Ateş, Ozan Güler, Gökhan Basman, Derya Dışpınar, Cevat Fahir Arısoy

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Grain refinement and obtaining homogeneous microstructure is the key parameter in casting of aluminum alloys. Ti has been traditionally used as grain refiner, however, inconsistency and heterogeneous dendrite arms, as well as fading efficiency, have been the drawbacks of Ti. Alternatively, Nb (Niobium) has gained attention. In this work, the effect of Nb was investigated in case of both as cast and T6 heat treated conditions. Different ratios of Nb (0.0, 0.03, 0.05, 0.07, 0.1 weight%) were added to AlSi11 alloy, mechanical properties were examined statistically, and relationship was established between microstructure and mechanical properties by examining the grain size and dendrite characteristics before and after heat treatment. Results indicate that in the case of as cast state; with the increasing addition of Nb has no significant effect on yield strength, however, it increases the tensile strength and elongation starting with 0.05wt% ratio, and it remains constant up to 0.1wt%. For the heat-treated condition; Nb addition provides increment at yield strength and tensile strength up to 0.05wt%, but it leads to decrementfrom 0.05 to 0.1wt%. The opposite is valid for the elongation; It decreases in between 0-0.05wt% then rises in range of 0.05-0.1wt%. Highest yield strength and ultimate tensile strength were found T6 heat treated 0.05wt% Nb addition. 0.05wt% was found as critical Nbaddition ratio for mechanical properties of Al-11Si alloys. Grain refinement and obtaining homogeneous microstructure is the key parameter in casting of aluminum alloys. Ti has been traditionally used as grain refiner, however, inconsistency and heterogeneous dendrite arms, as well as fading efficiency, have been the drawbacks of Ti. Alternatively, Nb (Niobium) has gained attention. In this work, the effect of Nb was investigated in case of both as cast and T6 heat treated conditions. Different ratios of Nb (0.0, 0.03, 0.05, 0.07, 0.1 weight%) were added to AlSi11 alloy, mechanical properties were examined statistically, and relationship was established between microstructure and mechanical properties by examining the grain size and dendrite characteristics before and after heat treatment. Results indicate that in the case of as cast state; with the increasing addition of Nb has no significant effect on yield strength, however, it increases the tensile strength and elongation starting with 0.05wt% ratio, and it remains constant up to 0.1wt%. For the heat-treated condition; Nb addition provides increment at yield strength and tensile strength up to 0.05wt%, but it leads to decrement from 0.05 to 0.1wt%. The opposite is valid for the elongation; It decreases in between 0-0.05wt% then rises in range of 0.05-0.1wt%. Highest yield strength and ultimate tensile strength were found T6 heat treated 0.05wt% Nb addition. 0.05wt% was found as critical Nbaddition ratio for mechanical properties of Al-11Si alloys.

Keywords: al-si alloy, grain refinement, heat treatment, mechanical properties, microstructure, niobium, sand casting

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Authors: Koichi Kurita

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In this study, we propose a real-time data collection technique for the detection of human walking motion from the charge generated on the human body. This technique is based on the detection of a sub-picoampere electrostatic induction current, generated by the motion, flowing through the electrode of a wireless portable sensor attached to the subject. An FFT analysis of the wave-forms of the electrostatic induction currents generated by the walking motions showed that the currents generated under normal and restricted walking conditions were different. Moreover, we carried out a cepstrum analysis to detect any differences in the walking style. Results suggest that a slight difference in motion, either due to the individual’s gait or a splinted leg, is directly reflected in the electrostatic induction current generated by the walking motion. The proposed wireless portable sensor enables the detection of even subtle differences in walking motion.

Keywords: human walking motion, motion measurement, current measurement, electrostatic induction

Procedia PDF Downloads 339

Authors: Ahmed Amine Hachicha

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Temperature effect on the performance of a photovoltaic module is one of the main concern that face this renewable energy, especially in the hot arid region, e.g United Arab Emirates. Overheating of the PV modules reduces the open circuit voltage and the efficiency of the modules dramatically. In this work, water cooling is developed to enhance the performance of PV modules. Different scenarios are tested under UAE weather conditions: front, back and double cooling. A spraying system is used for the front cooling whether a direct contact water system is used for the back cooling. The experimental results are compared to a non-cooling module and the performance of the PV module is determined for different situations. A mathematical model is presented to estimate the theoretical performance and validate the experimental results with and without cooling. The experimental results show that the front cooling is more effective than the back cooling and may decrease the temperature of the PV module significantly.

Keywords: PV cooling, solar energy, cooling methods, electrical efficiency, temperature effect

Procedia PDF Downloads 492

Authors: Leila Samiee, Amir Yadegari, Saeedeh Tasharrofi

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In the work presented here, nitrogen-doped graphene materials were synthesized and used as metal-free electrocatalysts for oxygen reduction reaction (ORR) under alkaline conditions. Paraphenylenediamine was used as N precursor. The N-doped graphene was synthesized under hydrothermal treatment at 200°C. All the materials have been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and X-ray photo-electron spectroscopy (XPS). Moreover, for electrochemical evaluation of samples, Rotating Disk electrode (RDE) and Cyclic Voltammetry techniques (CV) were employed. The resulting material exhibits an outstanding catalytic activity for the oxygen reduction reaction (ORR) as well as excellent resistance towards methanol crossover effects, indicating their promising potential as ORR electrocatalysts for alkaline fuel cells.

Keywords: alkaline fuel cell, graphene, metal-free catalyst, paraphenylen diamine

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Authors: Razieh Esfandiarisedgh

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Community architecture has been proposed as an alternative approach in architecture, with three political, sociological, and psychological approaches. In community architecture, the psychological approach, as the only approach related to community design, has an important index called a sense of community. Changes in today's modern society, such as the shrinking of families, cause a decrease in the sense of community and unwillingness of people. It has become a residential complex to be present in public spaces. This issue can be increased by creating motivation with the help of design for the presence and participation of people in public spaces and taking advantage of the facilities and quality of these spaces. This research used the qualitative research method, studied and collected information, and used observation and interviews in the selected sample. Through targeted sampling and matching it with the extracted design table, it was concluded that climate and culture are known as two important factors in the collective view of housing in Hamedan.

Keywords: community architecture, sense of community, environmental psychology, architecture

Procedia PDF Downloads 55

Authors: Syeda Azeem Unnisa

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The present study was undertaken at Jawaharnagar Solid Waste Municipal Dumpsite, Greater Hyderabad Municipal Corporation, Telangana State, India in 2017 which generates 90,000 litres of leachate per day. The main objective of the leachate treatment was to remove organic compounds like color, suspended solids, ammonia and COD by coagulation-flocculation using polyaluminum chloride (PAC) as coagulant which has higher coagulant efficiency and relative low cost compared to the conventional coagulants. Jar test apparatus was used to conduct experiments for pH 7, rapid mixing speed 150 rpm for 3 minute, slow mixing speed 30 rpm for 20 minute and the settling time of 30 minute for different dosage of PAC (0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 5.0 g/L). The highest percentage of removal of suspended solids, color, COD and ammonical nitrogen are 97%, 96%, 60% and 37% with PAC optimum dose of 2.0 g/l. The results indicate that the PAC was effective in leachate treatment which is very much suitable for high toxicity of waste and economically feasible for Indian conditions. The treated water can be utilized for other purpose apart from drinking.

Keywords: coagulant, leachate, polyaluminium chloride, treatment

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Authors: Maha Alaoui Ismaili, Bouchta Saidi, Mohamed Zahar, Abed Hamama

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Thirty one samples of raw camel milk obtained from the region of Laâyoune (South of Morocco) were examined for their microbial quality and presence of some pathogenic bacteria (Staphylococcus aureus and Salmonella sp.). pH of the samples ranged from 6.31 to 6.64 and their titratable acidity had a mean value of 18.56 °Dornic. Data obtained showed a strong microbial contamination with an average total aerobic flora of 1.76 108 ufc ml-1 and a very high fecal counts: 1.82 107 ; 3.25 106 and 3.75 106 ufc.ml-1 in average for total coliforms, fecal coliforms and enterococci respectively. Yeasts and moulds were also found at average respective levels of 3.13 106 and 1.60 105 ufc.ml-1. Salmonella sp. and S. aureus was detected respectively in 13% and 30% of the milk samples. These results indicate clearly the lack of hygienic conditions of camel milk production and storage in this region. Lactic acid bacteria were found at the following average numbers: 4.25 107 ; 4.45 107 and 3.55 107 ufc.ml-1 for Lactococci, Leuconostocs and Lactobacilli respectively.

Keywords: camel milk, microbial quality, Salmonella, Staphylococcus aureus

Procedia PDF Downloads 463

Authors: Ayoola T. Brimmo, Mohamed I. Hassan

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The push to mitigate the aluminum smelting industry’s enormous energy consumption and high emission releases is now even more persistent with the recent climate change happenings. Common approaches to achieve this have been focused on improving energy efficiency in the pot line and cast house sections of the smelter. However, the conventional energy efficiency analyses are based on the first law of thermodynamics, which do not shed proper light on the smelter’s degradation of energy. This just gives a general idea of the furnace’s performance with no reference to locations where improvement is a possibility based on the second law of thermodynamics. In this study, we apply exergy analyses on the pot line and cast house sections of the smelter to identify the locality and causes of energy degradation. The exergy analyses, which are based on a real life smelter conditions, highlight the possible locations for technology improvement in a typical smelter. With this established, methods of minimizing the smelter’s exergy losses are assessed.

Keywords: exergy analysis, electrolytic cell, furnace, heat transfer

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Authors: S. C. Kattimani

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This article deals with the analysis of active constrained layer damping (ACLD) of smart multiferroic or magneto-electro-elastic doubly curved shells. The kinematics of deformations of the multiferroic doubly curved shell is described by a layer-wise shear deformation theory. A three-dimensional finite element model of multiferroic shells has been developed taking into account the electro-elastic and magneto-elastic couplings. A simple velocity feedback control law is employed to incorporate the active damping. Influence of layer stacking sequence and boundary conditions on the response of the multiferroic doubly curved shell has been studied. In addition, for the different orientation of the fibers of the constraining layer, the performance of the ACLD treatment has been studied.

Keywords: active constrained layer damping (ACLD), doubly curved shells, magneto-electro-elastic, multiferroic composite, smart structures

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Authors: Omonov Jahongir Mahmatkulovic

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Purpose: To study the significance of D-dimer (DD), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen coagulation parameters (Fg) in predicting the course, severity and prognosis of COVID-19. Source and method of research: From September 15, 2021, to November 5, 2021, 93 patients aged 25 to 60 with suspected COVID-19, who are under inpatient treatment at the multidisciplinary clinic of the Tashkent Medical Academy, were retrospectively examined. DD, PT, APTT, and Fg were studied in dynamics and studied changes. Results: Coagulation disorders occurred in the early stages of COVID-19 infection with an increase in DD in 54 (58%) patients and an increase in Fg in 93 (100%) patients. DD and Fg levels are associated with the clinical classification. Of the 33 patients who died, 21 had an increase in DD in the first laboratory study, 27 had an increase in DD in the second and third laboratory studies, and 15 had an increase in PT in the third test. The results of the ROC analysis of mortality showed that the AUC DD was three times 0.721, 0.801, and 0.844, respectively; PT was 0.703, 0.845, and 0.972. (P<0:01). Conclusion”: Coagulation dysfunction is more common in patients with severe and critical conditions. DD and PT can be used as important predictors of mortality from COVID-19.

Keywords: Covid19, DD, PT, Coagulogram analysis, APTT

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Authors: Wanting Zeng, Hsunling Bai

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Silica was extracted from agriculture waste rice husk ash (RHA) and was used as the silica source for synthesis of RMCM-48 and RSBA-16. An alkali fusion process was utilized to separate silicate supernatant and the sediment effectively. The CTAB/Si and F127/Si molar ratio was employed to control the structure properties of the obtained RMCM-48 and RSBA-16 materials. The N2 adsorption-desorption results showed the micro-mesoporous RSBA-16 possessed high specific surface areas (662-1001 m2/g). All the obtained RSBA-16 materials were applied as the adsorbents for acetone adsorption. And the breakthrough tests clearly revealed that the RSBA-16(0.004) materials could achieve the highest acetone adsorption capacity of 186 mg/g under 1000 ppmv acetone vapor concentration at 25oC, which was also superior to ZSM-5 (71mg/g) and MCM-41 (157mg/g) under same test conditions. This can help to reduce the solid waste and the high adsorption performance of the obtained materials could consider as potential adsorbents for acetone adsorption.

Keywords: acetone, adsorption, micro-mesoporous material, rice husk ash (RHA), RSBA-16

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Authors: Md Abdullah Al Faruque

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A very large percentage of bridge failures are attributed to scouring around bridge piers and this directly influences public safety. Experiments are carried out in a 12-m long rectangular open channel flume made of transparent tempered glass. A 300 mm thick bed made up of sand particles is leveled horizontally to create the test bed and a 50 mm hollow plastic cylinder is used as a model bridge pier. Tests are carried out with varying flow depths and velocities. Data points of various scour parameters such as scour depth, width, and length are collected based on different flow conditions and visual observations of changes in the stream bed downstream the bridge pier are also made as the scour progresses. Result shows that all three major flow characteristics (flow depth, Froude number and densimetric Froude number) have one way or other affect the scour profile.

Keywords: bridge pier scour, densimetric Froude number, flow depth, Froude number, sand

Procedia PDF Downloads 163

Authors: Mina Henneb, Rafik Belabbas, Safia Zenia

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The objective of this study was to determine the prevalence and to identify the risk factors of Eimeria spp. and Giardia spp. infection in rabbits from the local population of four localities in northern Algeria. Dung samples were collected from 16 farms, totalling 111 rabbits, and were analysed by the flotation method. Additional, data regarding the farms and management practices were obtained by means of a questionnaire used in the surveys and interviews. The results revealed that the prevalence of Eimerias pp. contamination was 68.75% (11/16) for farms and 58.56% (65/111) for rabbits, respectively. The prevalence of Giardia spp. was respectively 56.25% (9/16) for farms and 11.7% (13/111) for rabbits. The analyses showed that the prevalence of Eimeria spp. was significantly higher in the farms that did not comply with hygiene and non-conventional feeding and watering. However, the prevalence of Giardia spp. was significant in rabbits kept in poor conditions of rearing. In conclusion, this study showed that the prevalence of these two parasites in rabbits from the local population is relevant and may have important implications for the rabbit industry and public health, especially in rural areas.

Keywords: Algeria, digestive parasites, prevalence, rabbits, risk factors

Procedia PDF Downloads 165

Authors: Kamel Laidi, Khelifa Benmansour, Ouahid Bouchhida

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Neural networks-based approach for 2-cells serial converter has been developed and implemented. The approach is based on a behavioural description of the different operating modes of the converter. Each operating mode represents a well-defined configuration, and for which is matched an operating zone satisfying given invariance conditions, depending on the capacitors' voltages and the load current of the converter. For each mode, a control vector whose components are the control signals to be applied to the converter switches has been associated. Therefore, the problem is reduced to a classification task of the different operating modes of the converter. The artificial neural nets-based approach, which constitutes a powerful tool for this kind of task, has been adopted and implemented. The application to a 2-cells chopper has allowed ensuring efficient and robust control of the load current and a high capacitors voltages balancing.

Keywords: neural nets, control, multicellular converters, 2-cells chopper

Procedia PDF Downloads 828

Authors: Brandtner-Hafner Martin

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Biocomposites have established themselves as a sustainable material class in the industry. Their advantages include lower density, lower price, and easier recycling compared to conventional materials. Now there are a variety of ways to measure their technical performance. One possibility is mechanical tests, which are widely used and standardized. However, these provide only very limited insights into damage capacity, which is particularly problematic under cracking conditions. To overcome such shortcomings, experimental tests were performed applying the fracture energetically GF-concept to study the structural safety of the interface under crack opening (mode-I loading). Two different types of biocomposites based on extruded henequen-fibers (NFRP) and wood-particles (WPC) in an HDPE matrix were evaluated. The results show that the fracture energy values obtained are higher than those given in the literature. This suggests that alternatives to previous linear elastic testing methods are needed to perform authentic safety evaluations of green plastics.

Keywords: biocomposites, structural safety, Gғ-concept, fracture analysis

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Authors: V. D. Thi, M. Li, M. Khelifa, M. El Ganaoui, Y. Rogaume

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This paper presents a two-dimensional model to study the heat and moisture transfer through porous building materials. Dynamic and static coupled models of heat and moisture transfer in porous material under low temperature are presented and the coupled models together with variable initial and boundary conditions have been considered in an analytical way and using the finite element method. The resulting coupled model is converted to two nonlinear partial differential equations, which is then numerically solved by an implicit iterative scheme. The numerical results of temperature and moisture potential changes are compared with the experimental measurements available in the literature. Predicted results demonstrate validation of the theoretical model and effectiveness of the developed numerical algorithms. It is expected to provide useful information for the porous building material design based on heat and moisture transfer model.

Keywords: finite element method, heat transfer, moisture transfer, porous materials, wood

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Authors: Assaad Ghazouani, Ati Abdessatar

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In the world, agriculture maintains a social and economic importance in the national economy. Its importance is distinguished by its ripple effects not only downstream but also upstream vis-à-vis the non-agricultural sector. However, the situation is relatively fragile because of weather conditions. In this work, we propose a model to highlight the impacts of climate change (CC) on economic growth in the world where agriculture is considered as a strategic sector. The CC is supposed to directly and indirectly affect economic growth by reducing the performance of the agricultural sector. The model is tested for Tunisia. The results validate the hypothesis that the potential economic damage of the CC is important. Indeed, an increase in CO2 concentration (temperatures and disruption of rainfall patterns) will have an impact on global economic growth particularly by reducing the performance of the agricultural sector. Analysis from a vector error correction model also highlights the magnitude of climate impact on the performance of the agricultural sector and its repercussions on economic growth

Keywords: Climate Change, Agriculture, Economic Growth, World, VECM, Cointegration.

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Authors: Elias Bensalem

Abstract:

This study investigates the effect of two types of captioning (full and keyword captioning) on listening comprehension. Thirty-six university-level EFL students participated in the study. They were randomly assigned to watch three video clips under three conditions. The first group watched the video clips with full captions. The second group watched the same video clips with keyword captions. The control group watched the video clips without captions. After watching each clip, participants took a listening comprehension test. At the end of the experiment, participants completed a questionnaire to measure their perceptions about the use of captions and the video clips they watched. Results indicated that the full captioning group significantly outperformed both the keyword captioning and the no captioning group on the listening comprehension tests. However, this study did not find any significant difference between the keyword captioning group and the no captioning group. Results of the survey suggest that keyword captioning were a source of distraction for participants.

Keywords: captions, EFL, listening comprehension, video

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Authors: Alvyra Galkienė, Ona Monkevičienė

Abstract:

The full participation of all pupils in the overall educational process is defined by the concept of inclusive education, which is gradually evolving in education policy and practice. It includes the full participation of all pupils in a shared learning experience and educational practices that address barriers to learning. Inclusive education applying the principles of Universal Design for Learning (UDL), which includes promoting students' involvement in learning processes, guaranteeing a deep understanding of the analysed phenomena, initiating self-directed learning, and using e-tools to create a barrier-free environment, is a prerequisite for the personal success of each pupil. However, the sustainability of quality education is affected by the transformation of education systems. This was particularly evident during the period of the forced transition from contact to distance education in the COVID-19 pandemic. Research Problem: The transformation of the educational environment from real to virtual one and the loss of traditional forms of educational support highlighted the need for new research, revealing the individual profiles of teachers using UDL-based learning and the pathways of sustainable transfer of successful practices to non-conventional learning environments. Research Methods: In order to identify individual latent teacher profiles that encompass the essential components of UDL-based inclusive teaching and direct leadership of students' learning, the quantitative analysis software Mplius was used for latent profile analysis (LPA). In order to reveal proven, i.e., sustainable, pathways for the transit of the components of UDL-based inclusive learning to distance learning, latent profile transit analysis (LPTA) via Mplius was used. An online self-reported questionnaire was used for data collection. It consisted of blocks of questions designed to reveal the experiences of subject teachers in contact and distance learning settings. 1432 Lithuanian, Latvian, and Estonian subject teachers took part in the survey. Research Results: The LPA analysis revealed eight latent teacher profiles with different characteristics of UDL-based inclusive education or traditional teaching in contact teaching conditions. Only 4.1% of the subject teachers had a profile characterised by a sustained UDL approach to teaching: promoting pupils' self-directed learning; empowering pupils' engagement, understanding, independent action, and expression; promoting pupils' e-inclusion; and reducing the teacher's direct supervision of the students. Other teacher profiles were characterised by limited UDL-based inclusive education either due to the lack of one or more of its components or to the predominance of direct teacher guidance. The LPTA analysis allowed us to highlight the following transit paths of teacher profiles in the extreme conditions of the transition from contact to distance education: teachers staying in the same profile of UDL-based inclusive education (sustainable transit) or jumping to other profiles (unsustainable transit in case of barriers), and teachers from other profiles moving to this profile (ongoing transit taking advantage of the changed new possibilities in the teaching process).

Keywords: distance education, latent teacher profiles, sustainable transit, UDL

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Authors: Gabriela T. Nakashima, Elias R. D. Padilla, Joao L. Barros, Gabriela B. Belini, Hiroyuki Yamamoto, Fabio M. Yamaji

Abstract:

Biochar can be an alternative to use sugarcane trash. Biochar is a solid material obtained from pyrolysis, that is a biomass thermal degradation with low or no O₂ concentration. Pyrolysis transforms the carbon that is commonly found in other organic structures into a carbon with more stability that can resist microbial decomposition. Biochar has a versatility of uses such as soil fertility, carbon sequestration, energy generation, ecological restoration, and soil remediation. Biochar has a great ability to retain water and nutrients in the soil so that this material can improve the efficiency of irrigation and fertilization. The aim of this study was to characterize biochar produced from sugarcane trash in three different pyrolysis temperatures and determine the lowest temperature with the high yield and carbon content. Physical characterization of this biochar was performed to help the evaluation for the best production conditions. Sugarcane (Saccharum officinarum) trash was collected at Corredeira Farm, located in Ibaté, São Paulo State, Brazil. The farm has 800 hectares of planted area with an average yield of 87 t·ha⁻¹. The sugarcane varieties planted on the farm are: RB 855453, RB 867515, RB 855536, SP 803280, SP 813250. Sugarcane trash was dried and crushed into 50 mm pieces. Crucibles and lids were used to settle the sugarcane trash samples. The higher amount of sugarcane trash was added to the crucible to avoid the O₂ concentration. Biochar production was performed in three different pyrolysis temperatures (200°C, 325°C, 450°C) in 2 hours residence time in the muffle furnace. Gravimetric yield of biochar was obtained. Proximate analysis of biochar was done using ASTM E-872 and ABNT NBR 8112. Volatile matter and ash content were calculated by direct weight loss and fixed carbon content calculated by difference. Porosity measurement was evaluated using an automatic gas adsorption device, Autosorb-1, with CO₂ described by Nakatani. Approximately 0.5 g of biochar in 2 mm particle sizes were used for each measurement. Vacuum outgassing was performed as a pre-treatment in different conditions for each biochar temperature. The pore size distribution of micropores was determined using Horváth-Kawazoe method. Biochar presented different colors for each treatment. Biochar - 200°C presented a higher number of pieces with 10mm or more and did not present the dark black color like other treatments after 2 h residence time in muffle furnace. Also, this treatment had the higher content of volatiles and the lower amount of fixed carbon. In porosity analysis, while the temperature treatments increase, the amount of pores also increase. The increase in temperature resulted in a biochar with a better quality. The pores in biochar can help in the soil aeration, adsorption, water retention. Acknowledgment: This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil – PROAP-CAPES, PDSE and CAPES - Finance Code 001.

Keywords: proximate analysis, pyrolysis, soil amendment, sugarcane straw

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