Studies on Stable Crack Growth

The goal of this work is to experimentally investigate the stable crack growth (SCG) fracture behavior of AISI 4340 alloy steel. A series of mode I and mixed mode SCG fracture tests were carried out on 8 mm thick compact tension (CT) specimens subjected to quasistatic loading. The wire cutting technique was used to introduce a pre-notch/ pre-crack of 0.05 mm root radius to the specimen. Five different loading angles Ψ between the loading axis and the crack surface were employed; 90° (mode I), 75°, 65°, 60° and 50°. Five different ratios of original crack length to specimen width ao/w were also employed, 0.41, 0.42, 0.43, 0.44 and 0.45. Different combinations of Ψ and ao/w were used. Data concerned with direction of initial crack extension load-load line displacement (L-LLD) diagrams, initiation and maximum loads, range of stable crack growth, crack blunting, crack front geometry, fracture surfaces, and scanning electron microscope fracto graphs were obtained. A noticeable blunting was observed prior the crack initiation. Although the crack commences its growth from a pre-notch / pre-crack of a straight front it has a considerable tunneling at each stage of stable crack growth. In mixed mode, the crack takes place along a straight-line path initially, inclined with the main crack at an angle equal to the direction of crack extension. The loading angle Ψ and the initial crack length to the specimen width ao/w ratio affect the SCG fracture behavior significantly. The direction of initial stable crack extension was determined through an elastic finite element analysis. There was reasonably good agreement between the experimental and the predicted results

Exploring the factors that influence students’ participation in English classrooms at Ibri College of Applied Sciences in Oman

This study is concerned with the process of how teachers and students manage classroom participation in the English Foreign Language (EFL) classroom. Student participation is often associated with their verbal and non-verbal interaction in class, and how they respond to teachers’ questions. The main aim of the study, then, is to explore the factors that influence students’ participation in the English classroom at Ibri College of Applied Sciences in Oman. The sample of the study includes two gender-mixed classes (Level A and Level C) from the Foundation Year program, as well as six foreign teachers who taught these classes, and were voluntarily chosen. Since many previous studies focus on analysing the verbal and non-verbal participation of students in the classroom, this study tries to explore deeper to discover the implicit and unseen causes of participation in an attempt to shed some light on the factors that may contribute to what happens in the class, rather than the actions themselves. This requires an understanding of the relationships between teachers and students and how they create the classroom context, as well as understanding the classroom as a unique social context. Three research methods (classroom observation, interviews and students' diaries) were used to provide the study with comprehensive qualitative data where each of these methods complemented the other. This study adapts some principles of ethnographic approach and grounded theory in dealing with data collection and analysis. The findings of the study emphasize the roles of teachers and students in shaping classroom participation, and confirm that classroom context is a unique social place where many interrelated factors contribute to how and why things happen in class. Furthermore, the findings point out several socio-cultural factors, such as shyness, religion, gender and culture, that influence much of what happens in the class. An interesting finding of this study is expressed by the learners’ positive perception of ‘shyness’, because it is seen as a positive natural feeling that shows a mutual respect of all this study’s participants, both male and female. It indicates that shyness is related to different causes, such as the unfamiliarity of the class context, and the expected social and Islamic practices. Finally, the study concludes that the classroom is a small complex world which has its unique culture and context. Therefore, EF teachers need to understand the complexity of the classroom and involve their learners in understanding and constructing this mini-society context for a better learning environment

Author Correction: Chlorination disadvantages and alternative routes for biofouling control in reverse osmosis desalination

In the original version of this Review Article the affiliation and address for Lorenzo Rosa were incorrectly given as "University of Parma, Department of Information Engineering, Parma 43121, Italy"

First Implementation of Transfusion Consent Policy in Oman : Audit of compliance from a tertiary care university hospital

Objectives: Transfusions are a common medical intervention. Discussion of the benefits, risks and alternatives with the patient is mandated by many legislations prior to planned transfusions. At the Sultan Qaboos University Hospital (SQUH), Muscat, Oman, a written transfusion consent policy was introduced in March 2014. This was the first time such a policy was implemented in Oman. This study therefore aimed to assess adherence to this policy among different specialties within SQUH. Methods: The medical records of patients who underwent elective transfusions between June and August 2014 were reviewed to assess the presence of transfusion consent forms. If present, the consent forms were examined for completeness of patient, physician and witness information. Results: In total, the records of 446 transfused patients (299 adult and 147 paediatric patients) were assessed. Haematology patients accounted for 50% of adult patients and 71% of paediatric patients. Consent was obtained for 75% of adult and 91% of paediatric patients. The highest adherence rate was observed among adult and paediatric haematology specialists (95% and 97%, respectively). Consent forms were correctly filled out with all details provided for 51% and 52% of adult and paediatric patients, respectively. Among inadequately completed forms, the most common error was a lack of witness details (20–25%). Conclusion: In most cases, the pre-transfusion consent policy was successfully adhered to at SQUH. However, further work is required to ensure full compliance with the consent procedure within different specialties. Implementation of transfusion consent in other hospitals in the country is recommended

Learning to teach algebra Secondary trainee-teachers knowledge of students errors and difficulties

Available from British Library Document Supply Centre- DSC:DXN057054 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Secondary trainee-teachers’ knowledge of students’ errors and difficulties in algebra

This study investigated trainee-teachers' explanations of students' errors in algebra and their suggested ways for addressing such errors. The findings indicate that only a small proportion of trainee-teachers understand the sort of characteristics that determine the complexity of an algebra problem such as the number of variables in the problem, the nature of the elements involved and, importantly, students' interpretations of the letters

Learning to teach algebra : secondary trainee-teachers' knowledge of students' errors and difficulties

This study investigates secondary trainee-teachers' knowledge of students' errors and difficulties in algebra. We noted that, on the one hand, there is a great deal of research about student's errors and difficulties in algebra. On the other hand, there are only few studies of teacher knowledge about student's errors. There are even fewer studies of secondary mathematics trainee-teachers' knowledge of student's errors and difficulties. This area of research therefore forms the focus of this study because it is less well-documented by research despite the fact that secondary trainee-teachers constitute the next generation of teachers. To investigate what trainee-teachers know about students' errors and difficulties in algebra, we carried out a national survey in which we asked the participants to explain given students' errors and then suggest ways for helping students who make the errors. We also asked them to predict the most likely errors that students might make when working out given algebra problems. In addition, we asked them to rank order the problems in a way suitable as a teaching sequence. Finally, we asked them to give their expectations about students' success in working out the problems. This study suggests that secondary mathematics trainee-teachers are able to suggest a teaching sequence that takes into account the relative difficulty of the algebra ideas that are part of the high school mathematics curriculum. For example, most can correctly identify rank-order algebra questions from those that particular groups of students find the easiest to those they find most difficult. the trainee-teachers are also able to predict the most likely errors that secondary students are known to make when encountering algebra in secondary school. On the other hand, the study indicates that less than one-fifth of secondary mathematics trainee-teachers are able to identify major sources of students' errors (i.e. the reason why such errors occurred). Consequently, most secondary mathematics trainee-teachers are unable to suggest ways that challenge students' thinking and make the students realise their faults in advance of the teacher attempting to add additional knowledge. Instead trainee-teachers are likely to devote time and energy to explaining the whole topic again.</p

Best practices and factors to enhance transfer of training in Oman

Increasing investments are devoted to human resources development in Oman. Training is an essential component of these investments. This study aims to explore the perceptions of trainers on the best practices to enhance the transfer of training. The study was guided by three main questions: (1) How can we best enhance transfer in Oman, (2) what does affect transfer of training in Oman, (3) who should be involved in the process of training transfer. Using Swanson and Holton‟s (2001) and Baldwin and Ford‟s (1988) models of the transfer of training, the study explores the transfer of training from a systemic and multidimensional perspective that represents the challenge of the transfer of training to performance (Burke and Hutchins, 2007). The current study employs the qualitative approach to provide answers to the research questions. Semi-structured interviews were used to investigate the views of the participants on the research problem, based on their experiences in the training field. The technique of semi-structured interviews allowed to get in-depth information on the trainers‟ opinions and, hence, to provide answers to the research questions. Moreover, the gathered data were analyzed qualitatively to suggest the most effective practices (best practices) that should be integrated in the training interventions. The study participants indicated that trainees‟ involvement, setting clear objectives, linking training outcomes to the workplace performance, supervisory support, evaluation assignments, post-training discussions, peers training, having supportive work climate, and performance observation as the best practices that enhance the transfer of training in Oman. Moreover, the participants reported some factors that affect training transfer to the workplace, such as expectations, trainees‟ characteristics, supervisor‟s or manager‟s attitude towards training, and work environment. They also determined a list of stakeholders, whom are able to support or hinder the transfer of training. The list includes training designers, trainers, supervisor, managers, peers, top management, and customers or clients of the organizations. To my knowledge, this could be the first study conducted on the issue of the transfer of training in the Omani context. The conclusions drawn from this study may guide the training managers and planners to take the proper procedures in order to boost the training effectiveness and deliver the required results in the workplace. The study may also support the efforts of the training professionals in Oman to uncover the weaknesses in the training process that may hinder the positive impact of training on the work environment