Availability of Books and Other Informational Materials and the Use of Academic Libraries.

Gone are the days when librarians perform duties manually except for the few libraries that have not automated their services. Ability to store up-to-date materials, retrieve them for use by the prospective users is very important. A good library is judged by the effective utilization of the resources of the library. The materials must be accessible to their users without the wastage of precious time. With the advent of computers and the internet, library operations have become simplified, faster, more accurate and current. Learning, teaching and research have become more interesting and less stressful as it used to be. Fears been expressed in some quarters that with the advent of computers and internet in libraries, the traditional librarians may become redundant and irrelevant in the scheme of things, may not be 100% correct as there are some minute and local information that may be so necessary to the researcher that may not be the internet Serials/periodical should be given proper place in the acquisition policy in any academic library in such a ration of 70:30 for books and periodicals respectively. Proper retrieval system should be put in place so that the materials so acquired will be put into judicious use. African Research Review Vol. 1 (3) 2007: pp. 51-6

Modern Library Facilities to Enhance Learning in a Teachers' College

This paper examines modern facilities for enhance teachers Education. A brief definition of the library was made well as attempt at what the objectives of an academic library should be. The concept, Education was examined and a brief but concise analysis of teacher education was also looked at. Modern facilities/Equipments in the library that can aid effective utilization of the resources of the library were discussed. A brief summary was also made. African Research Review Vol. 1 (3) 2007: pp. 198-21

Unexplored photoluminescence from bulk and mechanically exfoliated few layers of Bi2Te3

We report the exotic photoluminescence (PL) behaviour of 3D topological insulator Bi2Te3 single crystals grown by customized self-flux method and mechanically exfoliated few layers (18 plus minus 2 nm)/thin flakes obtained by standard scotch tape method from as grown Bi2Te3 crystals.The experimental PL studies on bulk single crystal and mechanically exfoliated few layers of Bi2Te3 evidenced a broad red emission in the visible region. These findings are in good agreement with our theoretical results obtained using the ab initio density functional theory framework.Comment: Main MS (17 Pages text including 4 Figs): Suppl. info. (4 pages); Accepted Scientific Report

Spin Glass Behavior in RuSr2Gd1.5Ce0.5Cu2O10

The dynamics of the magnetic properties of polycrystalline RuSr2Gd1.5Ce0.5Cu2O10 (Ru-1222) have been studied by ac susceptibility and dc magnetization measurements, including relaxation and ageing studies. Ru-1222 is a reported magneto-superconductor with Ru spins magnetic ordering at temperatures near 100 K and superconductivity in Cu-O2 planes below Tc ~ 40 K. The exact nature of Ru spins magnetic ordering is still debated and no conclusion has been reached yet. In this work, a frequency-dependent cusp was observed in ac susceptibility vs. T measurements, which is interpreted as a spin glass transition. The change in the cusp position with frequency follows the Vogel-Fulcher law, which is commonly accepted to describe a spin glass with magnetically interacting clusters. Such interpretation is supported by themoremanaent magnetization (TRM) measurements at T = 60 K. TRM relaxations are well described by a stretched exponential relation, and present significant ageing effects.Comment: 4 pages, 6 figures, submitted to Phys. Rev.

PENGEMBANGAN BAHAN AJAR ILMU KESEHATAN DAN GIZI PROGRAM SBI PENDIDIKAN BIOLOGI DAN IMPLEMENTASINYA MELALUI LESSON STUDY

Tujuan dari penelitian ini adalah mengembangkan bahan ajar ilmu kesehatan dan gizi (Health and Nutrition) dan mengaplikasikannya dalam pembelajaran melalui lesson study guna meningkatkan kualitas belajar dari aspek interaksi mahasiswa serta hasil belajar mahasiswa. Penelitian dilakukan dengan kegiatan penyusunan buku ajar Ilmu Kesehatan dan Gizi (Health and Nutrition) serta diimplementasikan melalui lesson study. Proses lesson study melalui tahapan pembentukan tim, perumusan tim apa yang akan dibelajarkan pada mahasiswa, penyusunan disain pembelajaran, pelaksanaan pembelajaran, analisa pembelajaran dan pengulangan tahap pembelajaran dengan perbaikan. Efektivitas adanya buku ajar diketahui melalui aspek pengamatan interaksi mahasiswa dalam proses pembelajaran serta hasil belajar. Berdasar hasil penelitian dapat disimpulkan bahwa pada akhir penelitian telah dihasilkan luaran buku ajar IKG (Health and Nutrition) yang telah diimplementasikan dalam pembelajaran melalui lesson study dan diketahui efektif meningkatkan kualitas pembelajaran dari aspek interaksi mahasiswa (mahasiswa antar mahasiswa, mahasiswa dengan dosen, mahasiswa dengan media) serta peningkatan hasil belajar (100% mahasiswa tuntas mencapai hasil belajar di atas 70) Kata kunci : bahan ajar, lesson study, Ilmu Kesehatan dan Gizi, Health and Nutritio

Impact of Zn substitution on phase formation and superconductivity of Bi1.6Pb0.4 Sr2Ca2Cu3-xZnxO10 with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12

Samples of series Bi1.6Pb0.4Sr2Ca2Cu3-xZnxO10 with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12 are synthesized by solid-state reaction route. All the samples crystallize in tetragonal structure with majority (> 90%) of Bi-2223 (Bi2Sr2Ca2Cu3O10) phase (c-lattice parameter ~ 36 A0). The proportion of Bi-2223 phase decreases slightly with an increase in x. The lattice parameters a and c of main phase (Bi-2223) do not change significantly with increasing x. Superconducting critical transition temperature (Tc) decreases with x as evidenced by both resistivity [(T)] and AC magnetic susceptibility [(T)] measurements. Interestingly the decrement of Tc is not monotonic and the same saturates at around 96 K for x > 0.06. In fact Tc decreases fast (~10K/at%) for x = 0.015 and 0.03 samples and later nearly saturates for higher x values. Present results of Zn doping in Bi-2223 system are compared with Zn doped other HTSC (High temperature superconducting) systems, namely the RE-123 (REBa2Cu3O7) and La-214 ((La,Sr)2CuO4).Comment: 12, pages of text and Figs. TO APPEAR IN Mod. Phys. Lett. B (2005)

INTERLAYER COUPLING AND THE METAL-INSULATOR TRANSITION IN Pr-SUBSTITUTED Bi(2)Sr(2)CaCu(2)O(8+y)

Substitution of rare-earth ions for Ca in Bi2Sr2CaCu2O8+y is known to cause a metal-insulator transition. Using resonant photoemission we study how this chemical substitution affects the electronic structure of the material. For the partial Cu-density of states at E_F and in the region of the valence band we observe no significant difference between a pure superconducting sample and an insulating sample with 60% Pr for Ca. This suggests that the states responsible for superconductivity are predomi- nately O-states. The partial Pr-4f density of states was extracted utilizing the Super- Koster-Kronig Pr 4d-4f resonance. It consists of a single peak at 1.36eV binding energy. The peak shows a strongly assymetric Doniach-Sunjic line- shape indicating the presence of a continuum of electronic states with sharp cut off at E_F even in this insulating sample. This finding excludes a bandgap in the insulating sample and supports the existance of a mobility gap caused by spatial localization of the carriers. The presence of such carriers at the Pr-site, between the CuO_2 planes shows that the electronic structure is not purely 2-dimensional but that there is a finite interlayer coupling. The resonance enhancement of the photoemission cross section, at the Pr-4d threshold, was studied for the Pr-4f and for Cu-states. Both the Pr-4f and the Cu-states show a Fano-like resonance. This resonance of Cu-states with Pr-states is another indication of coupling between the the Pr-states and those in the CuO_2 plane. Because of the statistical distribution of the Pr-ions this coupling leads to a non-periodic potential for the states in the CuO_2 plane which can lead to localization and thus to the observed metal-insulator transition.Comment: Gziped uuencoded postscript file including 7 figures Scheduled for publication in Physical Review B, May 1, 1995

Unexplored photoluminescence from bulk and mechanically exfoliated few layers of Bi2Te3

We report the exotic photoluminescence (PL) behaviour of 3D topological insulator Bi2Te3 single crystals grown by customized self-flux method and mechanically exfoliated few layers (18 +/- 2 nm)/thin flakes obtained by standard scotch tape method from as grown Bi2Te3 crystals. The experimental PL studies on bulk single crystal and mechanically exfoliated few layers of Bi2Te3 evidenced a broad red emission in the visible region from 600-690 nm upon 375 nm excitation wavelength corresponding to optical band gap of 2 eV. These findings are in good agreement with our theoretical results obtained using the ab initio density functional theory framework. Interestingly, the observed optical band gap is several times larger than the known electronic band gap of similar to 0.15 eV. The experimentally observed 2 eV optical band gap in the visible region for bulk as well as for mechanically exfoliated few layers Bi2Te3 single crystals clearly rules out the quantum confinement effects in the investigated samples which are well known in the 2D systems like MoS2, WS2, WSe2, and MoSe2 for 1-3 layers