Search results for: gender relation
1626 Screening for Internet Addiction among Medical Students in a Saudi Community
Authors: Nawaf A. Alqahtani, Ali M. Alqahtani, Khalid A. Alqahtani, Huda S. Abdullfattah, Ebtehal A. Alessa, Khalid S. Al Gelban, Ossama A. Mostafa
Abstract:
Background: The internet is an exciting medium that is becoming an essential part of everyday life. Although the internet is fully observed in Saudi Arabia, young people may be vulnerable to problematic internet use, possibly leading to addiction. Aim of study: To explore the magnitude of internet addiction (IA) among medical students associated risk factors and its impact on students' academic achievement. Subjects and Methods: A cross sectional study was conducted in 2014 on 571 medical students (293 males and 278 females) at the College of Medicine, King Khalid University, Abha, Saudi Arabia. Data Collection was done through using the Arabic version of the Compulsive Internet Use Scale and a checklist of demographic characteristics. Results: Age of participants ranged from 19 to 26 years (Mean+SD: 21.9+1.5 years). Internet access was available to 97.4% of students at home and to 80.2% of students at their mobile phones. The most frequently accessed websites by medical students were the social media (90.7%), scientific website (50.4%) and the news websites (31.3%). IA was mild in 47.8% of medical students while 5.8% had moderate IA. None of the students had severe IA. Prevalence of IA was significantly higher among female medical students (p=0.002), availability of internet at home (p=0.022), and availability of internet at the students' mobile phone (p=0.041). The mean General Point Average (GPA) was highest among students with mild IA (4.0+0.6), compared with 3.6+0.6 among those with moderate addiction, and 3.9+0.6 among those who did not show IA. Differences in mean GPA according to grade of IA were statistically significant ((P=0.001). Conclusions: Prevalence of IA is high among medical students in Saudi Arabia. Risk factors for IA include female gender, availability of internet at home or at the mobile phone. IA has a significant impact on students' GPA. Periodic screening of medical students for IA and raising their awareness toward the possible risk of IA are recommended.Keywords: internet addiction, medical students, risk factors, Saudi Arabia
Procedia PDF Downloads 5341625 Culturally Responsive School Leadership in Indigenous Schools in Malaysia
Authors: Nalini Murugaiyah
Abstract:
Indigenous students require a positive school environment where meaningful learning ought to be there to minimise myriad challenges. Therefore, Orang Asli student’s school environment should be culturally responsive and equipped with student-centred activities or provide constructively designed curriculum and pedagogy. This study sought to extend the knowledge of culturally responsive school leadership practises which relevant and responsive to Orang Asli students through th lens of a theoretical framework, Culturally Responsive School Leadership. The aim of the proposed study is to examine and understand the real-world application of leadership practices that are relevant and responsive to Orang Asli students in Malaysia. This study will also include the often-voiceless voices’ of Orang Asli students, parents, and community leaders to gain a deeper understanding of the process and experience of engaging in culturally responsive school leadership. The study will explore the differences between school leaders, teachers, parents, and community leaders in relation to culturally responsive school environment, non-Orang Asli school leaders’ and teachers’ support to the needs of Orang Asli children, children’s perspectives of teachers’ practices in the classroom align with their culture; and, the demonstration of teacher’s culturally responsive behaviour in the classroom. A basic qualitative study is the proposed research design for this study, and the data is collected through semi-structured interviews and focus group interviews. This qualitative research is designed to gain in-depth knowledge about how the principal’s leadership is culturally responsive towards the school environment, which will improve the quality of education received by the Orang Asli community in Malaysia, hence reducing the drop-out rates in Orang Asli students.Keywords: indigenous leadership, equity, inclusion, policy
Procedia PDF Downloads 711624 The Effects of Orientation on Energy and Plasticity of Metallic Crystalline-Amorphous Interface
Authors: Ehsan Alishahi, Chuang Deng
Abstract:
Commercial applications of bulk metallic glasses (BMGs) were restricted due to the sudden brittle failure mode which was the main drawback in these new class of materials. Therefore, crystalline-amorphous (C-A) composites were introduced as a toughening strategy in BMGs. In spite of numerous researches in the area of metallic C-A composites, the fundamental structure-property relation in these composites that are not exactly known yet. In this study, it is aimed to investigate the fundamental properties of crystalline-amorphous interface in a model system of Cu/CuZr by using molecular dynamics simulations. Several parameters including interface energy and mechanical properties were investigated by means of atomic models and employing Embedded Atom Method (EAM) potential function. It is found that the crystalline-amorphous interfacial energy weakly depends on the orientation of the crystalline layer, which is in stark contrast to that in a regular crystalline grain boundary. Additionally, the results showed that the interface controls the yielding of the crystalline-amorphous composites during uniaxial tension either by serving as sources for dislocation nucleation in the crystalline layer or triggering local shear transformation zones in amorphous layer. The critical resolved shear stress required to nucleate the first dislocation is also found to strongly depend on the crystalline orientation. Furthermore, it is found that the interaction between dislocations and shear localization at the crystalline-amorphous interface oriented in different directions can lead to a change in the deformation mode. For instance, while the dislocation and shear banding are aligned to each other in {0 0 1} interface plane, the misorientation angle between these failure mechanisms causing more homogeneous deformation in {1 1 0} and {1 1 1} crystalline-amorphous interfaces. These results should help clarify the failure mechanism of crystalline-amorphous composites under various loading conditions.Keywords: crystalline-amorphous, composites, orientation, plasticity
Procedia PDF Downloads 2941623 The Association between Psychosocial Characteristics, Training Variables and Well-Being: An Exploratory Study among Organizational Workers
Authors: Norshaffika I. Zaiedy Nor, Andrew P. Smith
Abstract:
Background: Training is essential to develop individuals’ expertise to meet current and future job demands and to improve work performance. At the same time, individuals’ well-being is crucial to ensure that they can fully and positively carry out their daily duties. In addition to the studies that have examined what constitutes well-being and the factors behind it, many researchers have investigated the predictors of training effectiveness and transfer of training. However, there has been very little integration between them. This study was an attempt to bridge the gap between training effectiveness predictors and well-being. Purpose: This research paper aimed to investigate the association between well-being among employees and psychosocial characteristics, together with training variables. Training variables consist of motivation to learn; learning; implementation intention; and cognitive dissonance. Methodology: In total, 210 workers who had undergone various training programs completed an online survey measuring various psychosocial characteristics, four training variables, and level of well-being. Findings: The results showed that certain types of positive psychosocial characteristics (e.g., positive personality, positive work behaviors, positive work and resources) predict motivation to learn, learning and implementation intention. Meanwhile, negative psychosocial characteristics (e.g. negative work demands and resources, negative coping) predict cognitive dissonance. Also, all the training variables had a moderate to high correlation with well-being. However, after controlling other variables (age, gender, education and psychosocial characteristics), none of the training variables predicted well-being. Self-determination theory, cognitive dissonance theory, and the DRIVE model were used to explain these findings. Conclusion: As there is limited research on the integration of training variables with well-being, this study gives a new perspective in the field of both training and well-being. Further investigations are needed to examine the relationships between them.Keywords: cognitive dissonance, implementation intention, learning, motivation to learn, psychosocial characteristics, well-being
Procedia PDF Downloads 2161622 Motivation Among Arab Learners of English in the UK
Authors: Safa Kaka
Abstract:
As more and more students are travelling to different countries to study and, in particular, to study English, the question of what motivates them to make such a large move has come under question. This is particularly pertinent in the case of Arab students who make up nearly 15% of the foreign student body in the UK. Given that the cultural differences between the UK and Arab nations are extremely wide, the decision to come to this country to study English must be driven by strong motivational forces. Numerous previous studies have considered what motivates foreign students to travel to the UK and other countries for their education or language learning but the specific motivators of Arab students have yet to be explored. This study undertakes to close that gap by examining the concepts and theories of motivation, both in general terms and in relation to English learning and foreign study. 70 Arab students currently studying in the UK were asked to participate in an online questionnaire which asked about their motivations for coming to the UK and for studying and learning English. A further six individuals were interviewed on a face to face basis. The outcomes have indicated that the factors which motivate the decision to come to the UK are similar to those that motivate the desire to learn English. In particular a motivation for self-improvement, career advancement and potential future benefits were cited by a number of respondents. Other indications were the ease of accessibility to the UK as an English speaking country, a motivation to experience different cultures and lifestyles and even political freedoms. Overall the motivations of Arab students were not found to be conspicuously different from those of other foreign students, although it was noted that their motivations did change, both positively and negatively following a period of time in the country. These changes were based on the expectations of the students pre-arrival and their actual experience of the country and its teaching approaches and establishments and were, as indicated both good and bad. The implications for the Arab student population and UK educational establishments are reviewed and future research pathways highlighted.Keywords: motivation, Arab learners of English, language teaching, applied linguistics
Procedia PDF Downloads 3501621 Perceived Physical Exercise Benefits among Staff of Tertiary Institutions in Adamawa State
Authors: Salihu Mohammed Umar
Abstract:
Perceived physical exercise benefits among staff of tertiary institutions in Adamawa State was investigated as a basis for formulating proper exercise intervention strategies. The study utilized descriptive survey design. The purpose of the study was to determine perceived exercise benefits among staff of tertiary institutions in Adamawa state, Nigeria. The instrument used for data collection was a questionnaire adapted from Exercise Benefit/Barrier Scale (EBBS) developed by Sechrist, Walker and Pender (1985) which was validated by five experts. Three hundred and thirty (330) copies of the questionnaire were distributed among study participants in six institutions of higher learning in Adamawa state. The scale comprised two components; Benefits and Barriers dimensions. To achieve this purpose, three research questions were posed. The instrument had a four response forced-choice Likert-type format with responses ranging from 4 = strongly agree (SA), 3 = Agree (A), 2 = Disagree (D) and 1 = Strongly Disagree (SD). The findings of the study revealed that both male and female staff in institutions of higher learning in Adamawa state perceived exercise as highly beneficial. However, male staff had higher perceived benefits score than their female counterparts. (Male: x̄ = 95.02. SD = 3.08) > female: x̄ = 94.04, SD = 4.35. There was also no significant difference in perceived exercise barriers between staff and students of tertiary institutions in Adamawa state. Based on the finding of the study, it was concluded that staff of tertiary institutions perceived exercise as highly beneficial. It was recommended that since staff of institutions of higher learning in Adamawa State irrespective of gender and religious affiliations have basic knowledge of perceived benefits of exercise, there is the need to explore programmes that will enable staff across the sub-groups to overcome barriers that could discourage physical exercise participation.Keywords: perception, physical exercise, staff, benefits
Procedia PDF Downloads 3191620 Motivation for Work and Organizational Commitment in an Engineering Public Faculty: A Perception of Technical and Administrative Employees
Authors: Fátima Aparecida de Carvalho, Ester Eliane Jeunon
Abstract:
This study addresses issues in the public service: motivation to work and organizational commitment. The goal of this research was to examine how it configures the motivation to work and organizational commitment of the technical and administrative effective staff of the School of Engineering at UFMG. For this purpose a descriptive research under a quantitative and qualitative approach has been performed. In the quantitative research it has been applied a questionnaire to all 146 technical and administrative institution effective staff, that configures a census research. This questionnaire was divided into three parts, the first one aimed at performing a socio-demographic survey of participants, the second one aimed to measure motivation and the third one aimed at measuring organizational commitment. The Bases Organizational Commitment Scale (EBACO) was used in the analysis of data obtained in the third part of the questionnaire. The qualitative research was conducted through interviews with 08 managers, with open-ended questions structured in an analysis category, thus contemplating the administrative structure of the School of Engineering. The results of the research revealed that there is no relevant difference between the hygiene and motivational indices, related to the staff´s gender and area of work. Nonetheless, it was observed higher motivational indices for staff with shorter duration of employment in the institution. Also, the results shown high organizational commitment of the staff with the institution, with a predominance of the component “Requirement for performance”, followed by commitments “Consistent line of activity”, “Affiliative” and “Affective”, which reached almost tge some average in this study. Finally the results showed that all commitment indices have positive moderated correlation to the motivational indices, except the “shortage of alternative” index.Keywords: motivation to work, organizational commitment, public service, human resources
Procedia PDF Downloads 4131619 Stress Perception, Ethics and Leadership Styles of Pilots: Implications for Airline Global Talent Acquisition and Talent Management Strategy
Authors: Arif Sikander, Imran Saeed
Abstract:
The behavioral pattern and performance of airline pilots are influenced by the level of stress, their ethical decision-making ability and above all their leadership style as part of the Crew Management process. Cultural differences of pilots, especially while working in ex-country airlines, could influence the stress perception. Culture also influences ethical decision making. Leadership style is also a variable dimension, and pilots need to adapt to the cultural settings while flying with the local pilots as part of their team. Studies have found that age, education, gender, and management experience are statistically significant factors in ethical maturity. However, in the decades to come, more studies are required to validate the results over and over again; thereby, providing support for the validity of the Moral Development Theory. Leadership style plays a vital role in ethical decision making. This study is grounded in the Moral Development theory and seeks to analyze the styles of leadership of airline pilots related to ethical decision making and also the influence of the culture on their stress perception. The sample for the study included commercial pilots from a National Airline. It is expected that these results should provide useful input to the literature in the context of developing appropriate Talent Management strategies. The authors intend to extend this study (carried out in one country) to major national carriers (many countries) to be able to develop a ultimate framework on Talent Management which should serve as a benchmark for any international airline as most of them (e.g., Emirates, Etihad, Cathay Pacific, China Southern, etc.) are dependent on the supply of this scarce resource from outside countries.Keywords: ethics, leadership, pilot, stress
Procedia PDF Downloads 1461618 Academic Staff Perspective of Adoption of Augmented Reality in Teaching Practice to Support Students Learning Remotely in a Crisis Time in Higher
Authors: Ebtisam Alqahtani
Abstract:
The purpose of this study is to investigate academic staff perspectives on using Augmented Reality in teaching practice to support students learning remotely during the COVID pandemic. the study adopted the DTPB theoretical model to guide the identification of key potential factors that could motivate academic staff to use or not use AR in teaching practices. A mixing method design was adopted for a better understanding of the study problem. A survey was completed by 851 academic staff, and this was followed by interviews with 20 academic staff. Statistical analyses were used to assess the survey data, and thematic analysis was used to assess the interview data. The study finding indicates that 75% of academic staff were aware of AR as a pedagogical tool, and they agreed on the potential benefits of AR in teaching and learning practices. However, 36% of academic staff use it in teaching and learning practice, and most of them agree with most of the potential barriers to adopting AR in educational environments. In addition, the study results indicate that 91% of them are planning to use it in the future. The most important factors that motivated them to use it in the future are the COVID pandemic factor, hedonic motivation factor, and academic staff attitude factor. The perceptions of academic staff differed according to the universities they attended, the faculties they worked in, and their gender. This study offers further empirical support for the DTPB model, as well as recommendations to help higher education implement technology in its educational environment based on the findings of the study. It is unprecedented the study the necessity of the use of AR technologies in the time of Covid-19. Therefore, the contribution is both theoretical and practiceKeywords: higher education, academic staff, AR technology as pedological tools, teaching and learning practice, benefits of AR, barriers of adopting AR, and motivating factors to adopt AR
Procedia PDF Downloads 1311617 Social Work Practice to Labour Welfare: A Proposed Model of Field Work Practicum and Role of Social Worker in India
Authors: Naeem Ahmed
Abstract:
Social work is a professional activity based on the approach of “helping people to help themselves” (Stroup). Social work education and practice both are based on humanitarian philosophy in which social workers try to increase the happiness of the society and to reduce the problems of society. Labour welfare is a specialised field of social work which especially focuses on welfare of organised and unorganised labour. In India labour is facing numerous problems in both organised and unorganised sectors because of ignorance, illiteracy, high rate of unemployment etc. In most of the Indian social work institutions we have this specialization with different names like Human Resource Management or Industrial Relation and Personnel Management or Industrial Relations and Labour Welfare or Industrial Social Work etc. Field work practice is integrated part of social work education curriculum in all specialised field. In India we have different field work practice models being followed in different institutions. The main objective of this paper is to prepare a universal field work practicum model in the field of labour welfare. This paper is exploratory in nature, researcher used personal experience and secondary data (model of field work practice in different institutions like Aligarh Muslim University, Pondicherry University, Central University of Karnataka, University of Lucknow, MJP Rohilkhand University Bareilly etc.) Researcher found that there is an immediate need to upgrade the curriculum or field work practice in this particular field, as more than 40 percent of total population engaged in either unorganised or organised sector (NSSO 2011-12) and they are not aware about their rights. In this way a social worker can play an important role in existing labour welfare facilities by making them aware.Keywords: field work, labour welfare, organised labour, social work practice, unorganised labour
Procedia PDF Downloads 4041616 Further Evidence for the Existence of Broiler Chicken PFN (Pale, Firm and Non-Exudative Meat) and PSE (Pale, Soft and Exudative) in Brazilian Commercial Flocks
Authors: Leila M. Carvalho, Maria Erica S. Oliveira, Arnoud C. Neto, Elza I. Ida, Massami Shimokomaki, Marta S. Madruga
Abstract:
The quality of broiler breast meat is changing as a result of the continuing emphasis on genetic selection for a more efficient meat production. Breast meat has been classified as PSE (pale, soft, exudative), DFD (dark, firm, dry) and normal color meat, and recently a third group has emerged: the so-called PFN (pale, firm, non-exudative) meat. This classification was based on pH, color and functional properties. The aim of this work was to confirm the existence of PFN and PSE meat by biochemical characterization and functional properties. Twenty four hours of refrigerated fillet, Pectoralis major, m. samples (n= 838) were taken from Cobb flocks 42-48 days old, obtained in Northeastern Brazil tropical region, the Northeastern, considered to have only dry and wet seasons. Color (L*), pH, water holding capacity (WHC), values were evaluated and compared with PSE group samples. These samples were classified as Normal (46Keywords: broiler breast meat, funcional properties, PFN, PSE
Procedia PDF Downloads 2501615 Smart Kids Coacher: Model for Childhood Obesity in Thailand
Authors: Pornwipa Daoduong, Jairak Loysongkroa, Napaphan Viriyautsahakul, Wachira Pengjuntr
Abstract:
Obesity is on of serious health problem in many countries including Thailand where the prevalence of childhood obesity has increased from 8.8 % in 2014 to 9.5 % in 2015 and 12.9 % in 2016. The Ministry of Public Health’s objective is to reduce prevalence of childhood Obesity to 10% or lower in 2017, by implementing the measure in relation to nutrition, physical activity (PA) and environment in 6,405 targeted school with proportion of school children with obesity is higher than 10 %. Smart Kids Coacher (SKC)” is a new innovative intervention created by Department of Health and consists of 252 regional and provincial officers. The SKC aims to train the super trainers about food and nutrition.PA and emotional control through implementing three learning activities including 1) Food for Fun is about Nutrition flag, Nutrition label, food portion and Nutrition surveillance; 2) Fun for Fit includes intermediated- and advanced level workouts within 60 minutes such as kangaroo dance, Chair stretching; and 3) Control emotional is about to prevent probability of access to unhealthy food, to ensure for having meal in appropriate time, and to recruit peers and family member to increase awareness among target groups. Apart from providing SKC lesson for 3,828 officers at district level, a number of students (2,176) as role model are selected through implementing “Smart Kids Leader: (SKL)”.Consequently. The SKC lowers proportion of childhood obesity from 17% in 2012 to 12.9% in 2016. Further, the SKC coverage should be expanded to other setting. Policy maker should be aware of the important of reduction of the prevalence of childhood obesity, and it’s related risk. Network and Collaboration between stakeholders are essential as well as an improvement of holistic intervention and knowledge “NuPETHS” for kids in the future.Keywords: childhood obesity, model, obesity, smart kids coacher
Procedia PDF Downloads 2451614 Impact of an Instructional Design Model in a Mathematics Game for Enhancing Students’ Motivation in Developing Countries
Authors: Shafaq Rubab
Abstract:
One of the biggest reasons of dropouts from schools is lack of motivation and interest among the students, particularly in mathematics. Many developing countries are facing this problem and this issue is lowering the literacy rate in these developing countries. The best solution for increasing motivation level and interest among the students is using tablet game-based learning. However, a pedagogically sound game required a well-planned instructional design model to enhance learner’s attention and confidence otherwise effectiveness of the learning games suffers badly. This research aims to evaluate the impact of the pedagogically sound instructional design model on students’ motivation by using tablet game-based learning. This research was conducted among the out-of-school-students having an age range from 7 to 12 years and the sample size of two hundred students was purposively selected without any gender discrimination. Qualitative research was conducted by using a survey tool named Instructional Material Motivational Survey (IMMS) adapted from Keller Arcs model. A comparison of results from both groups’ i.e. experimental group and control group revealed that motivation level of the students taught by the game was higher than the students instructed by using conventional methodologies. Experimental group’s students were more attentive, confident and satisfied as compared to the control group’s students. This research work not only promoted the trend of digital game-based learning in developing countries but also supported that a pedagogically sound instructional design model utilized in an educational game can increase the motivation level of the students and can make the learning process a totally immersive and interactive fun loving activity.Keywords: digital game-based learning, student’s motivation, instructional design model, learning process
Procedia PDF Downloads 4351613 Long-Term Cohort of Patients with Beta Thalassemia; Prevailing Role of Serum Ferritin Levels in Hypocalcemia and Growth Retardation
Authors: Shervin Rashidinia, Sara Shahmoradi, Seyyed Shahin Eftekhari, Mohsen Talebizadeh, Mohammad Saleh Sadeghi
Abstract:
Background: Beta-thalassemia Major (BTM) is a kind of hereditary hemolytic anemia which depended on regular monthly blood transfusion. However, iron deposition into the organs leads to multi-organ damage. The present study is the first study which aimed to evaluate the average of five-years serum ferritin level and compared by the prevalence of short stature and hypocalcemia. Materials/Methods: A cross-sectional retrospective study which a total of 140 patients with beta-thalassemia who were referred to Qom Thalassemia Clinic between February 2011 and July 2016 were enrolled to be reviewed. The exclusion criteria were consisting of incomplete medical records, diagnosis less than 2-years-ago and the blood transfusion less than every 4 weeks. The data including age, gender, weight, height, age of initial blood transfusion, age of initial chelation therapy, ferritin, and calcium were collected and analysis by SPSS version 24. Results: A total of 140 patients were enrolled. Of them, 75 (53.4%) were female. The mean age of the patients was 13.4±4.6 years.The mean age of initial diagnosis was 20.2±7.4 months. Hypocalcemia and short stature were occurred in 41 (29.3%) and 37 (26.4%) patients, respectively. The mean five-years serum ferritin level was significantly higher in the patients with short stature and hypocalcemia (P<0.0001). However, rise in serum ferritin level significantly increases the risk of short-stature and hypocalcemia (1.0004- and 1.0029 fold, respectively). Conclusion: We demonstrated that prevalence of short stature and hypocalcemia were significantly higher in the BTM.However, ferritin significantly increases the risk of short stature and hypocalcemia.Keywords: beta-thalassemia, ferritin, growth retardation, hypocalcemia
Procedia PDF Downloads 3311612 Chemical Modifications of Carotol and Their Antioxidant Activity
Authors: Dalvir Kataria, Khushminder Kaur Chahal, Amit Kumar
Abstract:
The carrot seed essential oil was obtained by hydrodistillation. Hexane, dichloromethane, and methanol solvents were used for extraction of carrot seed by Soxhlet extraction methods. The major and minor compounds identified in carrot seed essential oil were carotol (52.73), daucol (5.10), daucene (5.68), (E)-β-farnesene (5.40), β-cubebene (3.19), longifolenaldehyde (3.23), β-elimene (3.23), (E)-caryophyllene (1.22), β-bisabolene (2.95) etc. The chemical composition of hexane, dichloromethane, and methanol extracts was different. Carotol was the common compound present. Major compounds isolated were from the carrot seed essential oil by column chromatography. Chemical transformations of carotol (2) with mercuric acetate/sodium borohydride, dry hydrochloric acid gas, acetonitrile/sulfuric acid, selenium dioxide/t-butyl hydrogen peroxide, N-bromosuccinimide, hydrogen iodide, and phenol were carried out. The derivatives of carotol were designed to explore the significance of some structural modifications in relation to antioxidant activities. The structures of major compounds and derivatives were confirmed on the basis of FT-IR, 1HNMR and 13CNMR spectroscopy. Antioxidant activity of carrot seed essential oil, various extracts and isolated compounds were tested by in vitro models involving 2, 2-diphenyl-1-picrylhydrazyl (DPPH•), hydroxyl (OH•), nitric oxide (NO•), superoxide radical scavenging methods and ferric reducing antioxidant power assay (FRAP). Chemical transformations of major isolated compound carotol were carried out, and antioxidant activity of all compounds was undertaken. The major sesquiterpenoidcarotol isolated from carrot seed essential oil showed the highest antioxidant activity in all the methods. The methanol extract showed higher antioxidant potential as compared to carrot seed essential oil, hexane, and dichloromethane extracts.Keywords: antioxidant, carotol, carrot, DPPH
Procedia PDF Downloads 1351611 A Coupled Stiffened Skin-Rib Fully Gradient Based Optimization Approach for a Wing Box Made of Blended Composite Materials
Authors: F. Farzan Nasab, H. J. M. Geijselaers, I. Baran, A. De Boer
Abstract:
A method is introduced for the coupled skin-rib optimization of a wing box where mass minimization is the objective and local buckling is the constraint. The structure is made of composite materials where continuity of plies in multiple adjacent panels (blending) has to be satisfied. Blending guarantees the manufacturability of the structure; however, it is a highly challenging constraint to treat and has been under debate in recent research in the same area. To fulfill design guidelines with respect to symmetry, balance, contiguity, disorientation and percentage rule of the layup, a reference for the stacking sequences (stacking sequence table or SST) is generated first. Then, an innovative fully gradient-based optimization approach in relation to a specific SST is introduced to obtain the optimum thickness distribution all over the structure while blending is fulfilled. The proposed optimization approach aims to turn the discrete optimization problem associated with the integer number of plies into a continuous one. As a result of a wing box deflection, a rib is subjected to load values which vary nonlinearly with the amount of deflection. The bending stiffness of a skin affects the wing box deflection and thus affects the load applied to a rib. This indicates the necessity of a coupled skin-rib optimization approach for a more realistic optimized design. The proposed method is examined with the optimization of the layup of a composite stiffened skin and rib of a wing torsion box subjected to in-plane normal and shear loads. Results show that the method can successfully prescribe a valid design with a significantly cheap computation cost.Keywords: blending, buckling optimization, composite panels, wing torsion box
Procedia PDF Downloads 4111610 Digital Demands: Addressing the Digital Divide in Basic Education and Its Relation to Academic Performance and Aspirations
Authors: Jose Rodrigo Zubiri, Sofia Carmen Tomacruz
Abstract:
Amidst an increasingly digitalized society, information and communication technologies have been seamlessly integrated into the economic, social, and political life of individuals. Information has been regarded as a primary good, essential to the wellbeing and self-respect of individuals in society. The digital engagements of an individual play a key role in a variety of life outcomes ranging from academic performance to entrepreneurial success to health service uptake. As a result of varying degrees of access to the Internet and ICTs across populations and individuals, a digital divide emerges. Education, a sector pivotal to directing individual life trajectories, has been radically transformed with regards to the learning process and access to information and thus faces the implications of the digital divide, as new waves of inequalities are introduced in the classroom. As the period of basic education is critical to transitioning into civic life or higher education, digital inequalities are capable of aggravating pre-existing social inequalities. Through survey-questionnaires, conducted on 152 high school students from a Philippine public school, the study reveals the correlation of academic performance and aspirations (for their highest academic qualification) to access to digital technologies and the Internet, according to Van Dijk’s four measurements of digital poverty, namely: motivational access, material access, skills access, and usage access. The findings reveal a positive correlation for academic performance whereas no correlation was found between aspirations and digital access. In the study, significant correlational differences were also found between genders, specifically, in terms of skills access and academic performance.Keywords: digital divide, ICTs, inequality, education, life trajectories
Procedia PDF Downloads 2711609 Long-Term Modal Changes in International Traffic - Example of the Polish Eastern Border
Authors: Tomasz Komornicki
Abstract:
The possibilities of cross-border traffic depend on the degree of permeability of a given border as well as the state of the existing transport infrastructure. The aim of this paper is to identify the impact of economic transformation, EU accession, and infrastructure development on modal shifts in border traffic through the Polish eastern boundary. In the 1980s railway was still the main mode of cross-border transport in Poland. At the beginning of the 1990s, the role of the road and rail transborder passenger traffic was similar, but since 1993, the role of rail was decreasing. The general decline in rail infrastructure in Poland continued uninterruptedly until accession to the European Union. The slow opposite trend can be observed later as a result of the inflow of European funds. In the countries neighbouring Poland from the east, these processes took place with some delay, and the loss of railway position was not so drastic. Therefore, cross-border railway connections have been maintained for quite a long time since the break-up of the USSR. However, finally, cross-border rail transport proved to be completely inflexible in relation to both economic, geopolitical, and transport transformations. It has been shown that the current modal split of the passenger border traffic was shaped by the following factors: a) closure of many transborder railway lines, especially local ones; b) the signing of an agreement on minor border traffic with Ukraine; c) rapidly growing number of citizens of Ukraine working in Poland (unofficial transportation of workers by car directly to their workplaces in Poland); d) the emergence of low-cost air connections between Ukraine and Poland and the growing role of air transport in the Russia-Poland relationship. The summary points to the possibility of a renewed increase in the importance of rail transport on the eastern border of the European Union.Keywords: modal change, border, rail transport, Poland
Procedia PDF Downloads 2021608 Establishment of Reference Interval for Serum Protein Electrophoresis of Apparently Healthy Adults in Addis Ababa, Ethiopia
Authors: Demiraw Bikila, Tadesse Lejisa, Yosef Tolcha, Chala Bashea, Mehari Meles Tigist Getahun Genet Ashebir, Wossene Habtu, Feyissa Challa, Ousman Mohammed, Melkitu Kassaw, Adisu Kebede, Letebrhan G. Egzeabher, Endalkachew Befekadu, Mistire Wolde, Aster Tsegaye
Abstract:
Background: Even though several factors affect reference intervals (RIs), the company-derived values are currently in use in many laboratories worldwide. However, little or no data is available regarding serum protein RIs, mainly in resource-limited setting countries like Ethiopia. Objective: To establish a reference interval for serum protein electrophoresis of apparently healthy adults in Addis Ababa, Ethiopia. Method: A cross-sectional study was conducted on a total of 297 apparently healthy adults from April-October 2019 in four selected sub-cities (Akaki, Kirkos, Arada, Yeka) of Addis Ababa, Ethiopia. Laboratory analysis of collected samples was performed using Capillarys 2 Flex Piercing analyzer, while statistical analysis was done using SPSS version 23 and med-cal software. Mann-Whitney test was used to check Partitions. Non-parametric method of reference range establishment was performed as per CLSI guideline EP28A3C. Result: The established RIs were: Albumin 53.83-64.59%, 52.24-63.55%; Alpha-1 globulin 3.04-5.40%, 3.44-5.60%; Alpha-2 globulin 8.0-12.67%, 8.44-12.87%; and Beta-1 globulin 5.01-7.38%, 5.14-7.86%. Moreover, Albumin to globulin ratio was 1.16-1.8, 1.09-1.74 for males and females, respectively. The combined RIs for Beta-2 globulin and Gamma globulin were 2.54-4.90% and 12.40-21.66%, respectively. Conclusion: The established reference interval for serum protein fractions revealed gender-specific differences except for Beta-2 globulin and Gamma globulin.Keywords: serum protein electrophoresis, reference interval, Addis Ababa, Ethiopia
Procedia PDF Downloads 2421607 Use of a Symptom Scale Based on Degree of Functional Impairment for Acute Concussion
Authors: Matthew T. McCarthy, Sarah Janse, Natalie M. Pizzimenti, Anthony K. Savino, Brian Crosser, Sean C. Rose
Abstract:
Concussion is diagnosed clinically using a comprehensive history and exam, supported by ancillary testing. Frequently, symptom checklists are used as part of the evaluation of concussion. Existing symptom scales are based on a subjective Likert scale, without relation of symptoms to clinical or functional impairment. This is a retrospective review of 133 patients under age 30 seen in an outpatient neurology practice within 30 days of a probable or definite concussion. Each patient completed 2 symptom checklists at the initial visit – the SCAT-3 symptom evaluation (22 symptoms, 0-6 scale) and a scale based on the degree of clinical impairment for each symptom (22 symptoms, 0-3 scale related to functional impact of the symptom). Final clearance date was determined by the treating physician. 60.9% of patients were male with mean age 15.7 years (SD 2.3). Mean time from concussion to first visit was 6.9 days (SD 6.2), and 101 patients had definite concussions (75.9%), while 32 were diagnosed as probable (24.1%). 94 patients had a known clearance date (70.7%) with mean clearance time of 20.6 days (SD 18.6) and median clearance time of 19 days (95% CI 16-21). Mean total symptom score was 27.2 (SD 22.9) on the SCAT-3 and 14.7 (SD 11.9) for the functional impairment scale. Pearson’s correlation between the two scales was 0.98 (p < 0.001). After adjusting for patient and injury characteristics, an equivalent increase in score on each scale was associated with longer time to clearance (SCAT-3 hazard ratio 0.885, 95%CI 0.835-0.938, p < 0.001; functional impairment scale hazard ratio 0.851, 95%CI 0.802-0.902, p < 0.001). A concussion symptom scale based on degree of functional impairment correlates strongly with the SCAT-3 scale and demonstrates a similar association with time to clearance. By assessing the degree of impact on clinical functioning, this symptom scale reflects a more intuitive approach to rating symptoms and can be used in the management of concussion.Keywords: checklist, concussion, neurology, scale, sports, symptoms
Procedia PDF Downloads 1551606 The Factors Associated with Health Status among Community Health Volunteers in Thailand
Authors: Lapatrada Numkham, Saowaluk Khakhong, Jeeraporn Kummabutr
Abstract:
Non-communicable diseases (NCDs) are the leading cause of death in worldwide. Thailand also concerns and focuses on reduction a new case of these diseases. Community Health Volunteers (CHV) is important health personnel in primary health care and performs as a health leader in the community. If the health of CHV changes, it would impact on the performance to promote health of families and community. This cross-sectional study aimed to 1) describe the health status of community health volunteers and 2) examine the factors associated with health status among community health volunteers. The sample included 360 community health volunteers in a province in central Thailand during September-December 2014. Data were collected using questionnaires on health information, knowledge of health behaviors, and health behaviors. Body weight, height, waist circumference (WC), blood pressure (BP), and blood glucose (BS) (fingertip) were assessed. Data were analyzed using descriptive statistics and chi-square test. There were three hundred and sixty participants with 82.5% being women. The mean age was 54 + 8.9 years. Forty-seven percent of the participants had co-morbidities. Hypertension was the most common co-morbidity (26.7%). The results revealed that the health status of the volunteers included: no underlying disease, having risk of hypertension (HT) & diabetes mellitus (DM), and having HT&DM at 38.3%, 30.0%, and 31.7% respectively. The chi-square test revealed that the factors associated with health status among the volunteers were gender, age, WC and body mass index (BMI). The results suggested that community health nurses should; 1) implement interventions to decrease waist circumference and lose weight through education programs, especially females; 2) monitor people that have a risk of HT&DM and that have HT&DM by meeting and recording BP level, BS level, WC and BMI; and 3) collaborate with a district public health officer to initiate a campaign to raise awareness of the risks of chronic diseases among community health volunteers.Keywords: community health volunteers, health status, risk of non-communicable disease, Thailand
Procedia PDF Downloads 3611605 Relation between Electrical Properties and Application of Chitosan Nanocomposites
Authors: Evgen Prokhorov, Gabriel Luna-Barcenas
Abstract:
The polysaccharide chitosan (CS) is an attractive biopolymer for the stabilization of several nanoparticles in acidic aqueous media. This is due in part to the presence of abundant primary NH2 and OH groups which may lead to steric or chemical stabilization. Applications of most CS nanocomposites are based upon the interaction of high surface area nanoparticles (NPs) with different substance. Therefore, agglomeration of NPs leads to decreasing effective surface area such that it may decrease the efficiency of nanocomposites. The aim of this work is to measure nanocomposite’s electrical conductivity phenomena that will allow one to formulate optimal concentrations of conductivity NPs in CS-based nanocomposites. Additionally, by comparing the efficiency of such nanocomposites, one can guide applications in the biomedical (antibacterial properties and tissue regeneration) and sensor fields (detection of copper and nitrate ions in aqueous solutions). It was shown that the best antibacterial (CS-AgNPs, CS-AgNPs-carbon nanotubes) and would healing properties (CS-AuNPs) are observed in nanocomposites with concentrations of NPs near the percolation threshold. In this regard, the best detection limit in potentiometric and impedimetric sensors for detection of copper ions (using CS-AuNPs membrane) and nitrate ions (using CS-clay membrane) in aqueous solutions have been observed for membranes with concentrations of NPs near percolation threshold. It is well known that at the percolation concentration of NPs an abrupt increasing of conductivity is observed due to the presence of physical contacts between NPs; above this concentration, agglomeration of NPs takes place such that a decrease in the effective surface and performance of nanocomposite appear. The obtained relationship between electrical percolation threshold and performance of polymer nanocomposites with conductivity NPs is important for the design and optimization of polymer-based nanocomposites for different applications.Keywords: chitosan, conductivity nanoparticles, percolation threshold, polymer nanocomposites
Procedia PDF Downloads 2131604 Consumer Behavior in Buying Organic Product: A Case Study of Consumer in the Bangkok Metropolits and Vicinity
Authors: Piluntana Panpluem, Monticha Putsakum
Abstract:
The objectives of this study were to investigate 1) consumers’ behaviors in buying organic products; and 2) the relationships between personal factors, cultural factors, social factors, psychological factors and marketing mix factors, and the behavior in buying organic products of consumers in the greater Bangkok metropolitan area. The sample group was 400 consumers at the age of 15 and older, who bought organic agricultural products from green markets and green shops in Bangkok, including its suburbs. The data were collected by using a questionnaire, which were analyzed by descriptive statistics and chi-square test. The results showed that the consumers bought 3 – 4 types of fresh vegetables with a total expenditure of less than 499 Baht each time. They purchased organic products mainly at a supermarket, 2 – 4 times per month, most frequently on Sundays, which took less than 30 minutes of shopping each time. The purpose of the purchase was for self-consuming. Gaining or retaining good health was the reason for the consumption of the products. Additionally, the first considered factor in the organic product selection was the quality. The decisions in purchasing the products were made directly by consumers, who were influenced mainly by advertising media on television. For the relationships among personal, cultural, social, psychological and marketing mix factors, and consumers’ behavior in buying organic products, the results showed the following: 1) personal factors, which were gender, age and educational level, were related to the behavior in terms of “What”, “Why”, and “Where” the consumers bought organic products (p<0.05); 2) cultural factors were related to “Why” the consumers bought organic products (p<0.05); 3) social factors were related to “Where” and “How” the consumers bought organic products (p<0.05); 4) psychological factors were related to “When” the consumers bought organic products (p<0.05). 5) For the marketing mix factors, “Product” was related to “Who participated” in buying, “What” and “Where” the consumers bought organic products (p<0.05), while “Price” was related to “What” and “When” the consumers bought organic products (p<0.05). “Place” was related to “What” and “How” the consumers bought organic products (p<0.05). Furthermore, “Promotion” was related to “What” and “Where” the consumers bought organic products (p<0.05).Keywords: consumer behavior, organic products, Bangkok Metropolis and Vicinity
Procedia PDF Downloads 2871603 Quantitative Analysis of Potential Rainwater Harvesting and Supply to a Rural Community at Northeast of Amazon Region, Brazil
Authors: N. Y. H. Konagano
Abstract:
Riverside population of Brazilian amazon suffers drinking water scarcity, seeking alternative water resources such as well and rivers, ordinary polluted. Although Amazon Region holds high annual river inflow and enough available of underground water, human activities have compromised the conservation of water resources. In addition, decentralized rural households make difficult to access of potable water. Main objective is to analyze quantitatively the potential of rainwater harvesting to human consumption at Marupaúba community, located in northeast of Amazon region, Brazil. Methods such as historical rainfall data series of municipality of Tomé-Açu at Pará state were obtained from Hydrological Information System of National Water Agency (ANA). Besides, Rippl method was used to calculate, mainly, volume of the reservoir based on difference of water demand and volume available through rainwater using as references two houses (CA I and CA II) as model of rainwater catchment and supply. Results presented that, from years 1984 to 2017, average annual precipitation was 2.607 mm, average maximum precipitation peak was 474 mm on March and average minimum peak on September was 44 mm. All months, of a year, surplus volume of water have presented in relation to demand, considering catchment area (CA) I = 134.4m² and demand volume =0.72 m³/month; and, CA II = 81.84 m² and demand volume = 0.48 m³/month. Based on results, it is concluded that it is feasible to use rainwater for the supply of the rural community Marupaúba, since the access of drinking water is a human right and the lack of this resource compromises health and daily life of human beings.Keywords: Amazon Region, rainwater harvesting, rainwater resource, rural community
Procedia PDF Downloads 1511602 Self-Stigma Regarding Mental Illness: An Empirical Study
Authors: Linta Koka
Abstract:
Aim: The way people with severe mental disorders deal with self-stigma and how it affects their self-esteem is a problem that has gained much attention in recent years. The primary aim of this study was to empirically explore the link between self-stigma and self-esteem of individuals with the presence of a mental illness, offering a novel perspective by exploring the same variables amongst a sample without a mental illness. Methods: This study utilized a cross-sectional study. Participants with (N=85) and without (N=75) a mental health issue were included from Darlingdon's Mind organization. Participants completed two scales, one of Self-Stigma of Mental Illness Scale and one of Self-Esteem, following some demographics questions. Results: According to the primary hypothesis, self-stigma significantly correlates with self-esteem in the clinical population. Furthermore, gender and ethnicity, above all the demographics, positively correlates to the relationship of self-stigma with self-esteem in people who endure a mental health issue. Limitations: A significant limitation is that of the size of the sample of participants conducted in this study. The clinical population was limited to 85 participants, and the control group consisted of 76 participants. Since the sample was not representative. The small size used did not allow any comparisons between the group with mental illness and the control group. There was a restricted time to approach the participants since the online survey was released by the end of May. Conclusions: Individuals suffering from mental illnesses may internalize stigmatizing stereotypes on an explicit level. Efforts should be made to lessen the harmful impact stigma may have on mentally ill people, such as worsening symptoms or delays in receiving care. Further study is needed within this small research topic to improve awareness and regulate mental health among the general population. Undoubtedly, people with mental disorders are stigmatized; therefore, more research is required to explore all factors contributing to mentally ill patients' devaluation.Keywords: self-stigma, mental illness, self-esteem, clinical population, non-clinical population
Procedia PDF Downloads 651601 Assessing Household Energy Savings and Consumer Behavior in Padang City
Authors: Prima Fithri, Lusi Susanti, Karin Bestarina
Abstract:
Indonesia's electrification ratio is still around 80.1%, which means that approximately 19.9% of households in Indonesia have not been getting the flow of electrical energy. Household electricity consumptions in Indonesia are generally still dominated by the public urban. In the city of Padang, West Sumatera, Indonesia, about 94.10% are power users of government services (PLN). The most important thing of the issue is human resources efficient energy. Consumer behavior in utilizing electricity becomes significant. Intensive questioner survey, in-depth interview and statistical analysis are carried out to collect scientific evidences of the behavioral based changes instruments to reduce electricity consumption in household sector. The questioner was developed to include five factors assuming affect the electricity consumption pattern in household sector. They are: attitude, energy price, household income, knowledge and other determinants. The survey was carried out in Padang, West Sumatra Province Indonesia. About 210 questioner papers were proportionally distributed to households in 11 districts in Padang. Stratified sampling was used as a method to select respondents. The results show that the household size, income, payment methods and size of house are factors affecting electricity saving behavior in residential sector. Household expenses on electricity are strongly influenced by gender, type of job, level of education, size of house, income, payment method and level of installed power. These results provide a scientific evidence for stakeholders on the potential of controlling electricity consumption and designing energy policy by government in residential sector.Keywords: electricity, energy saving, household, behavior, policy
Procedia PDF Downloads 5281600 The Study of Platelet-Rich Plasma(PRP) on Wounds of OLEFT Rats Using Expression of MMP-2, MMP-9 mRNA
Authors: Ho Seong Shin
Abstract:
Introduction: A research in relation to wound healing also showed that platelet-rich plasma (PRP) was effective on normal tissue regeneration. Nonetheless, there is no evidence that when platelet-rich plasma was applied on diabetic wound, it normalize diabetic wound healing process. In this study, we have analyzed matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) expression to know the effect of PRP on diabetic wounds using Reverse transcription-polymerase chain reaction (RT-PCR) of MMP-2, MMP-9 mRNA. Materials and Methods: Platelet-rich plasma (PRP) was prepared from blood of 6 rats. The whole 120-mL was added immediately to an anticoagulant. Citrate phosphonate dextrose(CPD) buffer (0.15 mg CPDmL) in a ratio of 1 mL of CPD buffer to 5 mL of blood. The blood was then centrifuged at 220g for 20minutes. The supernatant was saved to produce fibrin glue. The participate containing PRP was used for second centrifugation at 480g for 20 minutes. The pellet from the second centrifugation was saved and diluted with supernatant until the platelet concentration became 900,000/μL. Twenty male, 4week-old OLETF rats were underwent operation; each rat had two wounds created on left and right sides. The each wound of left side was treated with PRP gel, the wound of right side was treated with physiologic saline gauze. Results: RT-PCR analysis; The levels of MMP-2 mRNA in PRP applied tissues were positively related to postwounding days, whereas MMP-2 mRNA expression in saline-applied tissues remained in 5day after treatment. MMP-9 mRNA was undetectable in saline-applied tissues for either tissue, except 3day after treatment. Following PRP-applied tissues, MMP-9 mRNA expression was detected, with maximal expression being seen at third day. The levels of MMP-9 mRNA in PRP applied tissues were reported high intensity of optical density related to saline applied tissues.Keywords: diabetes, MMP-2, MMP-9, OLETF, PRP, wound healing MMP-9
Procedia PDF Downloads 2741599 Household's Willingness to Pay for Safe Non-Timber Forest Products at Morikouali-Ye Community Forest in Cameroon
Authors: Eke Balla Sophie Michelle
Abstract:
Forest provides a wide range of environmental goods and services among which, biodiversity or consumption goods and constitute public goods. Despite the importance of non-timber forest products (NTFPs) in sustaining livelihood and poverty smoothening in rural communities, they are highly depleted and poorly conserved. Yokadouma is a town where NTFPs is a renewable resource in active exploitation. It has been found that such exploitation is done in the same conditions as other localities that have experienced a rapid depletion of their NTFPs in destination to cities across Cameroon, Central Africa, and overseas. Given these realities, it is necessary to access the consequences of this overexploitation through negative effects on both the population and the environment. Therefore, to enhance participatory conservation initiatives, this study determines the household’s willingness to pay in community forest (CF) of Morikouali-ye, eastern region of Cameroon, for sustainable exploitation of NTFPs using contingent valuation method (CVM) through two approaches, one parametric (Logit model) and the other non-parametric (estimator of the Turnbull lower bound). The results indicate that five species are the most collected in the study area: Irvingia gabonensis, the Ricinodendron heudelotii, Gnetum, the Jujube and bark, their sale contributes significantly to 41 % of total household income. The average willingness to pay through the Logit model and the Turnbull estimator is 6845.2861 FCFA and 4940 FCFA respectively per household per year with a social cost of degradation estimated at 3237820.3253 FCFA years. The probability to pay increases with income, gender, number of women in the household, age, the commercial activity of NTFPs and decreases with the concept of sustainable development.Keywords: non timber forest product, contingent valuation method, willingness to pay, sustainable development
Procedia PDF Downloads 4521598 The Concept of Female Beauty in Contemporary (2000-2020) Fine Arts and Design
Authors: Maria Ukolova
Abstract:
Social and cultural processes over the past decades have largely affected the understanding of conventional female beauty all over the world. Fine arts and design tendencies could not remain unchanged and show a dynamic interplay with female rights, gender equality, and other social processes. As of now, the area lacks comprehensive academic research on the tendencies of understanding female beauty in contemporary art. This article makes an attempt to outline and analyse the main tendencies of contemporary works of art that turn to the image of a woman, including photography, digital art, and various forms of design. The research bases itself on paintings, performing arts, photography, digital art, and various forms of design, mainly on the principle of the most broadly resonated in society, as an empirical basis, and on existing researches in the sphere. The results of the research show a general trend that the concept of female beauty in art is either challenged as such or its understanding has shifted to individuality, diversity, and the state of mental health. However, some categories of art, such as digital art in the gaming industry, remain resistant to change and retain the appearance-based understanding of beauty. Specific tendencies are, firstly, aestheticization of all types of appearances; secondly, a ubiquitous interest in mental health issues and understanding the state of mental health as a part of beauty; thirdly, a certain infantilization of the image of the woman is observed as compared to previous decades. The significance of the findings of the research is to contribute to a scientific understanding of the concept of beauty in contemporary art and to give ground for prospective further related research in sociology, phycology, etc. The findings might be perceived not only by academics but also by artists and practitioners in the spheres of art and society.Keywords: fine arts, history of art, contemporary art, concept of beauty
Procedia PDF Downloads 881597 Moisture Resistant K-loaded ZIF-8 Catalyst for Glycerol Carbonate Production
Authors: Anshu Tyagi
Abstract:
Zeolitic imidazolate frameworks (ZIFs), a subclass of metal-organic frameworks (MOFs) with structures resembling aluminosilicate zeolites, are gaining significant attention due to their unique properties. ZIF-8, in particular, has shown high surface area and enhanced hydrophobicity, making it a promising candidate for catalytic applications. In this study, ZIF-8 was synthesized in an aqueous medium by mixing 2-methylimidazole (mIm) with zinc nitrate hexahydrate (Zn) in deionized water. To improve the basicity and catalytic performance of ZIF-8, a series of K-loaded ZIF-8 catalysts (K/ZIF-8) were prepared by varying the KOH content from 5 to 10 wt%. Characterization of the synthesized catalysts was conducted using powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and temperature-programmed desorption (TPD) techniques. The ZIF-8 and K/ZIF-8 catalysts were applied in the transesterification of glycerol (GL) and dimethyl carbonate (DMC) to form glycerol carbonate (GLC). Various reaction parameters, including DMC/GL molar ratio, KOH loading, catalyst amount, and reaction temperature, were systematically studied to optimize the GLC yield. Under optimized conditions, the 10 wt% KOH-loaded ZIF-8 catalyst (10-K/ZIF-8) demonstrated excellent catalytic activity, achieving up to 95% GLC yield at a DMC/GL molar ratio of 3:1 within 0.5 hours. Remarkably, despite the hygroscopic nature of potassium, the catalyst exhibited significant water resistance, maintaining performance with up to 5 wt% water in relation to GL. Furthermore, the catalyst retained its activity after three recycling cycles without any notable loss in catalytic efficiency. This study highlights the potential of K/ZIF-8 as an efficient, water-tolerant catalyst for the transesterification of GL with DMC, offering high GLC yields and recyclability.Keywords: metal-organic frameworks (MOFs), zeolitic imidazolate frameworks (ZIFs), transesterification, sustainable catalytic
Procedia PDF Downloads 17