SUMMARY

This thesis entitled comprises four chapters and ends with alist of references.

The first chapter covers the literature up to date of the reaction of nucleophilic substitution reactions and their different mechanisms.then describes .of preparation of the methods

the procedure used to determina the rate constant for the reaction and kinetic data

then deals the discussion and interpretation of the results from the above mentioned reaction .

application of Hammett relationship . and application of Bronsted equation

Technology has become an essential part of education today, and learning environment has changed from that of many years ago; students need to use technology as an alternative effective learning tool for learning English language as a foreign language (EFL). Most of current studies in the educational use of social media seem to pay more attention to the students' use of Facebook in learning. This research explores 14 university learners use of Facebook group and it mainly focuses on lecturers' role in Facebook group. This qualitative study involved observation and some interview questions. Current findings highlight that there are potential benefits to using Facebook for learning with reference that these students still need a guideline and support from their lecturers to learn English via Facebook. This paper suggests that considerable students' content knowledge of educational technology as Facebook is required to improve their learning. This study hopes to add and expand current body of knowledge about learning English in relation to Facebook used in English foreign language context. 

Group work is believed to be one of the possible solutions to the problem of dealing with large number of students within one speaking class. However, how students perceive group work in their EFL speaking classes is an area that needs to be researched. This study looks at how students perceive group work in their speaking classes and their preference of being given a specific role in a given speaking task that involves working in a group. A questionnaire has been distributed to 42 students to highlight their perceptions towards group work. Results from this study revealed that EFL students seem to like the idea of working in groups in their speaking classes as they reported a number of benefits that they gain when they work in groups, for example, they feel more independent, they have a chance to share ideas, and they speak English in most of the time in the class. However, a number of drawbacks have been also reported by the students, for example, the domination of one student in the group, some students find it difficult to work in a group of mixed gender, and low level students sometimes feel frustrated to work in group.  

In this paper we define the Weyl algebra by two ways, and we study some theorems related to this algebra. We also study it widely as a ring of differential operators.

in Higher education sector, assessment criteria are important in measuring students‟ learning and support teaching. The assessment of students EFL writing could help in identifying students‟ learning needs, progress and also teaching. This research examines university tutors and students understanding of assessment criteria used in EFL writing skills. The analysis shows important finding that most of the tutors did not inform students about assessment criteria or discuss them which affected the students‟ ability to gain higher grades and produce better work. This might be due to lack of knowledge about the importance of providing and involving students in the criteria. The finding prompts a re-thinking about the use of assessment criteria and could make significant contribution to improve and provide great insights into the education especially in the Libyan context and in an EFL context.