Evaporation of Two Dimensional Black Holes

Callan, Giddings, Harvey and Strominger have proposed an interesting two dimensional model theory that allows one to consider black hole evaporation in the semi-classical approximation. They originally hoped the black hole would evaporate completely without a singularity. However, it has been shown that the semi-classical equations will give a singularity where the dilaton field reaches a certain critical value. Initially, it seems this singularity will be hidden inside a black hole. However, as the evaporation proceeds, the dilaton field on the horizon will approach the critical value but the temperature and rate of emission will remain finite. These results indicate either that there is a naked singularity, or (more likely) that the semi-classical approximation breaks down when the dilaton field approaches the critical value.Comment: 12 page

Agogo Presbyterian College of Education Under the Missionaries and After Take-Over by the Government (1931-2013): A Comparative Study

The study analyzed the Agogo Presbyterian College of Education (1930-1971) and when it was taken over by the Government (1972-2013). This became relevant in the wake of the recent plea by the churches that the Government should hand over Mission Schools to the churches. The study therefore examines the state of management and leadership and infrastructural development both under the regime of the Missionaries and the Government. It also sought to assess academic standard of the students, and the discipline of the College, qualification of the teachers, supervision, and students’ patronage of library and entry grade of students to the College with the view of establishing the progression or retrogression over the period. In doing this, a comparative study was undertaken and data were derived from archival materials of the Agogo Presbyterian College of Education, and direct interviews with past Principals and Administrators of the College. The results revealed that despite an increase in student-intake (210 students in 1942 to 750 students in 2014) with a corresponding increase of teachers (from 5 missionary teachers with lower academic degrees in 1931 to 28 teachers with masters qualifications), inadequate infrastructural development; lack of discipline and competitions among students have characterized APCE since it was managed by the Government as compared to the Missionaries. The study recommends that the Government would complete the construction of the students‟ hall complex, and also put up large auditorium and classroom blocks to accommodate the high students’ intake in the College to enhance education delivery

Multiple Dis[L]abling Conditions

Produced by The Center on Disability Studies, University of Hawaii at Manoa Honolulu, Hawaii and The School of Social Sciences, The University of Texas at Dallas Richardson, Texas for The Society for Disability Studies

A manual for teaching consonants and vowels in speech and reading(kindergarten and primary grades).

Thesis (Ed.M.)--Boston Universit

Magnetospheric signatures of ionospheric density cavities observed by cluster

AJBR ackowledges support from STFC under consolidated grant ST/K000993/1.We present Cluster measurements of large amplitude electric fields corre- lated with intense downward field-aligned currents, observed during a nightside crossing of the auroral zone. The data are reproduced by a simple model of magnetosphere-ionosphere coupling which, under different conditions, can also produce a divergent electric field signature in the downward current region, or correlation between the electric and perturbed magnetic fields. We conclude that strong electric field associated with intense downward field-aligned current, such as this observation, is a signature of ionospheric plasma depletion caused by the downward current. It is also shown that the electric field in the downward current region correlates with downward current density if a background field is present, e.g. due to magnetospheric convection.Publisher PDFPeer reviewe

Neutrino Detection using Lead Perchlorate

We discuss the possibility of using lead perchlorate as a neutrino detector. The primary neutrino interactions are given along with some relevant properties of the material.Comment: 2 pages, 2 figures, TAUP-99, TEX fil