Energy and exergy analysis of using turbulator in a parabolic trough solar collector filled with mesoporous silica modified with copper nanoparticles hybrid nanofluid

Designing the most efficient parabolic trough solar collector (PTSC) is still a demanding and challenging research area in solar energy systems. Two effective recommended methods for this purpose that increase the thermal characteristics of PTSCs are adding turbulators and nanofluids. To study the effects of the two approaches on the energy efficiency of PTSCs, a stainless steel turbulator was used and solid nanoparticles of Cu/SBA-15 were added to the water with the volume concentrations of 0.019% to 0.075%. The generated turbulence in the fluid flow was modeled by the SST k–ω turbulent model. The results in daylight demonstrated that energy efficiency increases steadily by 11:30 a.m., and then, starts to drop gradually due to more irradiations at noon. It was observed that applying the turbulator to the studied PTSC has a significant influence on the enhancement of energy efficiency. Adding the nanoparticles augmented the average Nusselt number inside the solar collector in various studied Reynolds numbers. It was also found that the increase in volume concentrations of nanoparticles enhances heat transfer regularly

Investigating the extent of critical thinking in fielddependent and field-ındependent students’ blog posts

Identifying critical thinking and learners’ characteristics is very important in an online learning environment. This study investigated the extent of critical thinking between field-dependent and field-independent students’ critical thinking and blogging. It is a quasi-experimental in which a quantitative method was employed on an intact class of the students to develop their CT skills in their argumentative blog posts. Different aspects of CT skills, such as observation, inference, reasoning, assumption, and credibility were explained to the students. The GEFT developed by Witkin et al. (1971) was applied to evaluate the students' field dependency. Moreover, Newman et al. model (1996) was applied to analyze students’ CT in their blog posts. No significant difference was found in the number of positive and negative CT indicators used by FD and FI students. Therefore, educators who wish to improve the students’ learning may train the students in CT skills by using a pre-planned and systematic procedure without worrying about learners’ cognitive styles, particularly their field dependency

Validity of the Persian Blog Attitude Questionnaire: An Evidence-Based Approach

Validity evidence is provided for a Persian blog attitude questionnaire (P-BAQ). P-BAQ was administered to 565 Iranians and factor analysis and rating scale model identified affective, behavioral, and perseverance, and confidence dimensions underlying the data. P-BAQ’s validity argument was supported by the theoretical and psychometric evidence, although adding a few items to the instrument would improve its construct representativeness

Pedagogical blogging : promoting tertiary level students` critical thinking by using socratic questions.

This study seeks to investigate the effects of pedagogical blogging on tertiary students’ critical thinking. The authors initially discuss the role of Socratic questions in promoting students’ critical thinking through Web 2.0 tools. They further explain how blogging was incorporated into the curriculum of a course for tertiary level students enrolled in a Malaysian university. Finally, they show how qualitative and quantitative methods were used to evaluate the efficiency of Socratic questions in students’ blogging and its effects on students’ critical thinking. Findings suggest that implementing Socratic questions in students’ blogging would help promote students’ critical thinking

Effects of gibberellic acid, potassium nitrate and calcium sulfate on pomegranate fruit splitting and fruit characteristics

Pomegranate fruit splitting is one of the major problems of production which leads to economic and quality losses. Cultivars with thin peel such as ‘Kadru’ are more susceptible to this disorder. The present study was carried out in a completely randomized block design to evaluate the influence of foliar application of gibberellic acid (GA3), potassium nitrate (KNO3) and calcium sulfate (CaSO4) on alleviating fruit splitting of ‘Kadru’ cultivar in addition to some physical and quality characteristics in an orchard in Farugh region (Fars Province, Iran). Uniform healthy pomegranate trees were chosen for the experiment. Treatments included the foliar application of GA3 (50, 100 and 200 mg L-1), CaSO4 (2500, 3000 and 3500 mg L-1) and KNO3 (5000, 10,000 and 15,000 mg L-1) in May and early September in two successive years. The results indicated that most of the treatments significantly increased the number of healthy fruits, however, the application of KNO3 at 5000 mg L-1 concentration did not cause a significant response. Foliar application of GA3 (100 mg L-1) was evaluated as the most effective treatment in the reduction of the fruit splitting. Also, KNO3 (10,000 mg L-1) treatment mitigated the percentage of fruit splitting and had a beneficial impact on the weight of 100 arils, percentage of the edible part of the fruits and ascorbic acid concentration. Therefore, foliar application of KNO3 (10,000 mg L-1) is recommendable for the reduction of the pomegranate fruit splitting

Investigating the factor structure of the blog attitude scale

Due to the wide application of advanced technology in education, many attitude scales have been developed to evaluate learners’ attitudes toward educational tools. However, with the rapid development of emerging technologies, using blogs as one of the Web 2.0 tools is still in its infancy and few blog attitude scales have been developed yet. In view of this need, a lot of researchers like to design a new scale based on their conceptual and theoretical framework of their own study rather than using available scales. The present study reports the design and development of a blog attitude scale (BAS). The researchers developed a pool of items to capture the complexity of the blog attitude trait, selected 29 items in the content analysis, and assigned the scale comprising 29 items to 216 undergraduate students to explore the underlying structure of the BAS. In exploratory factor analysis, three factors were discovered: blog anxiety, blog desirability, and blog self-efficacy; 14 items were excluded. The extracted items were subjected to a confirmatory factor analysis which lent further support to the BAS underpinning structure

Devenir minorité : une monographie des institutions de la communauté chiite iranienne de Montréal

À la suite de l'installation d'une diaspora musulmane au Québec, cette communauté et leurs expériences migratoires sont devenues des sujets de recherche en sciences sociales. Toutefois, la diversité confessionnelle et ethnique de cette communauté semble négligée par ces études. Ce mémoire cherche à combler ce manque et mettre en lumière les chiites duodécimains, la plus grande minorité au sein de l'islam. Particulièrement, on se concentre sur les iraniens en tenant compte des multiples variables qui structurent leurs institutions en contexte migratoire. Les pratiquants immigrants de cette confession ont occupé un statut majoritaire dans leur pays d'origine mais, à Montréal, ils se voient considérés comme une minorité à l'échelle de la société hôte, mais aussi au niveau des communautés musulmanes ellemême. Je me suis demandée comment cette population interagissaient dans ce nouveau contexte ? Hormis les enjeux traditionnellement rencontrés par la diaspora musulmane, quelles sont les questions générées par le statut de chiite et d'iranien immigrant ? Dans un processus de négociation avec la société hôte et en tenant compte de l'expérience apportée dans les bagages des migrants, comment la diversité interne de la religion pourrait-elle se traduire au niveau institutionnel? Est-ce que ce statut minoritaire rapproche les immigrants iraniens ? Ou bien, au contraire, à distance de la supervision étatique iranienne sur la religion, de nouvelles formes de religiosité émergent ? J'ai rédigé une monographie à partir d'observations participantes réalisées au sein des institutions chiites iraniennes à Montréal. J'ai, en parallèle, conduit des entretiens approfondis avec 17 responsables et membres de ces organisations. Enfin, j'ai établi une typologie des quatre visions du chiisme à traverse une analyse comparative des institutions actives au sein de la communauté. Cette typologie renvoie à quatre approches différentes de l'action communautaire et des stratégies du " vivre " en contexte migratoire.Installation of the Muslim diaspora in Quebec has given rise to much researches in social sciences about this population and its migratory experiences became research topic of social scientists. However, it seems that intern diversity of this population in term of ethnicity and religious affiliation remain neglected. This thesis responds to this lacuna by highlighting Twelver Shias, the largest minority within Islam. Specifically, the Iranian community, by considering multiple variables that structured their institutions in the migratory context. The first-generation of Shia practitioners have held majority status in their home country of Iran, but they are viewed as a minority not only in the host society but also in the Muslim community itself. I wondered how this population interacts with their new status. Beyond the studies that have been composed about the Muslim diaspora, what kind of question is related to their affiliation to Shia confession and Iranian nation? In the process of negotiation with the host society and concerning what they bring with themselves as migrants, does the internal diversity of this religion reflect in their organizations? Does the minority status bring them closer together? Or in contrast, far from state supervision on religion, do new forms of religiosity appear? This monograph about Iranian Shia institutions in Montreal is written by using participatory observation. I did 17 in-depth interviews with organizers and members of these organizations. Finally, I have established a typology of the four visions of Shiism through a comparative analysis of active institutions in the community. This typology refers to four different approaches to community actions and "living" strategies in a migratory context

Promoting tertiary level students' critical thinking through the use of Socratic questioning on the blog

Over the past decade, much has been done to improve students' critical thinking in education. This study investigates if applying Socratic questioning on the blog can promote students' critical thinking. It applies a generic model, which associates with three fundamental components. Participants were an intact class of tertiary level students enrolled in an obligatory course. Students practiced Socratic questioning during face-to-face and online sessions. To serve this goal, they were asked to be attentive and share their ideas or questions with other students on the blog. Students' critical thinking ability was assessed using the Cornell Critical Thinking Test before and after they were trained in Socratic questioning. The results showed that the Socratic questioning training had a significant positive change on students' critical thinking ability. If students master the art of Socratic questioning, they can bring it into various courses they take. They can also use it in different discussions they engage in, and apply it not only in raising and asking questions about what is taught, but also in making questions concerning the issues in their daily life in a meaningful way

Impact of variable fluid properties on forced convection of Fe3O4/CNT/water hybrid nanofluid in a double-pipe mini-channel heat exchanger

The objective of this study is to assess the hydrothermal performance of a non-Newtonian hybrid nanofluid with temperature-dependent thermal conductivity and viscosity compared with a Newtonian hybrid nanofluid with constant thermophysical properties. A counter-current double-pipe mini-channel heat exchanger is studied to analyze the effects of the hybrid nanofluid. The nanofluid is employed as the coolant in the tube side, while the hot water flows in the annulus side. Two different nanoparticles including tetramethylammonium hydroxide-coated Fe3O4 (magnetite) nanoparticles and gum arabic-coated carbon nanotubes are used to prepare the water-based hybrid nanofluid. The results demonstrated that the non-Newtonian hybrid nanofluid always has a higher heat transfer rate, overall heat transfer coefficient, and effectiveness than those of the Newtonian hybrid nanofluid, while the opposite is true for the pressure drop, pumping power, and performance evaluation criterion. Supposing that the Fe3O4-carbon nanotube/water hybrid nanofluid is a Newtonian fluid with constant thermal conductivity and viscosity, there leads to large error in the computation of pressure drop (1.5–9.71%), pumping power (1.5–9.71%), and performance evaluation criterion (18.24–19.60%), whereas the errors in the computation of heat transfer rate, overall heat transfer coefficient, and effectiveness are not considerable (less than 2.91%)

Uniform and virus-free citrus rootstocks production via nucellus culture

Prevalence of various virus and virus-like diseases is among the main reasons for the decrease in quality and quantity of citrus crops. These diseases are mainly spread through the propagation method in citrus which is budding. Using nucellus culture of bitter orange and Mexican lime seeds, uniform and virus-free rootstocks could be produced so that the diseases prevalence could be prevented. In order to generate adventitious shoots from nucellus culture in each of the two rootstocks, direct organogenesis method is used. In all conducted experiments, Murashige and Skoog (MS) medium were used. Two plant growth regulators of benzyl adenine (BA) in 0, 1, 1.5 and 2 mg l-1 concentration and gibberellins (GA) in 0, 1 and 2 mg l-1 concentration were used in the medium and the main effects of each plant growth regulator were studied separately and their interaction on shoot generation were also surveyed. Considering the retrieved data, it was determined that the interaction of BA and GA have a higher impact on shooting, comparing to the cases where each of the regulators is used alone. In Mexican lime rootstock, the best culture medium for generating shoots from nucellus culture is the culture medium containing 2 mg l-1 BA and 2 mg l-1 GA and in bitter orange rootstock, the highest shooting rate was attributed to the culture medium containing 2 mg l-1 GA and 1 mg l-1 BA. For the Mexican lime and bitter orange shoots rooting, indole butyric acid (IBA) was used. The concentrations of this plant growth regulator used in Mexican lime were 0, 0.5, 1 and 1.5 mg l-1 and for bitter orange were 0, 1 and 1.5 mg l-1. The highest rooting rate for Mexican lime was in culture medium containing 0.5 mg l-1 IBA and for bitter orange, it was the culture medium containing 1 mg l-1 IBA. The obtained plantlets were gradually adapted with the external environment