Design of the main racetrack microtron accelerator end magnets of the Institute of Physics of University of São Paulo

This work deals with the design of the Institute of Physics of the University of São Paulo (IFUSP) main racetrack microtron accelerator end magnets. This is the last stage of acceleration, comprised of an accelerating section (1.04 m) and two end magnets (0.1585 T), in which a 5.10 MeV beam, produced by a racetrack microtron booster has its energy raised up to 31.15 MeV after 28 accelerations. POISSON code was used to give the final configuration that includes auxiliary pole pieces (clamps) and auxiliary homogenizing gaps. The clamps create a reverse fringe field region and avoid the vertical defocusing and the horizontal displacement of the beam produced by extended fringe fields; PTRACE code was used to perform the trajectory calculations in the fringe field region. The auxiliary homogenizing gaps improve the field uniformity as they create a magnetic shower that provides uniformity of ±0.3%, before the introduction of the correcting coils that will be attached to the pole faces. This method of correction, used in the IFUSP racetrack microtron booster magnets, enabled uniformity of ±0.001% in an average field of 0.1 T and will also be employed for these end magnets. © 1999 The American Physical Society.

Availability and Use of Audiovisual and Electronic Resources by Distance Learning Students in Nigerian Universities: a Case Study of National Open University of Nigeria (NOUN), Ibadan Study Centre

This study investigated the availability and use of audiovisual and electronic resources by distance learning students at the National Open University of Nigeria (NOUN). A questionnaire was administered tothe distance learning students selected across the various departments of the NOUN. The findings revealed that even though NOUN made provision for audiovisual and electronic resources for students' use, a majority of the audiovisual and electronic resources are available through personal provision by the students.The study also revealed regular use of audiovisual and electronic resources by the distance learning students. Constraints on use include poor power supply, poor infrastructure, lack of adequate skill, and high cost of access.

Perception of the Internet as an Enabler of Scholarship among Postgraduate Students of the University of Ibadan, Oyo State, Nigeria

This paper investigates postgraduate students' perceptions of the Internet as an enabler of scholarship.The specific objectives of the study are: to ascertain the perception held by the postgraduate students on the Internet usage as an enabler of scholarship, and to determine what interventions are necessary to facilitate postgraduate students' adoption of the Internet as a tool for learning and research. The subjects of study are the postgraduate students of the University of Ibadan, Nigeria. A random sample of 100 students was selected with representation from each faculty of the university. A questionnaire instrument with a 12-item scale was designed and administered. Data analysis was done using the chi-square statistical method. The results show that majority of the postgraduate students have positive perceptions of the Internet as an enabler of information sourcing for learning and research. However some of these students have low self-efficacy in Internet use for information sourcing.