Issues and Concerns in Implementing Quality Circles in Public School Management in Nigeria

Quality improvement in educational institutions in Nigeria and the world at large is a major concern. Countries all over the world are therefore making concerted efforts towards the improvement of educational standards. One of the management techniques applied in most of these countries especially Japan, Britain and America is the Quality Control circles. Its application in Nigeria raises a lot of concerns. These concerns and issues bother on the structure, techniques; methods; and reactions of management of the institutions in implementing the recommendations of quality circles. These and many other issues and concerns form the major crux of this paper. The paper concludes that inspite of these issues and concerns; Quality circle is a technique that will assist in the achievement of educational goals Keywords: Issues and concerns, Implementing, Public Schools and Management

CP Violation and Dark Matter

A brief review is given of the effects of CP violation on the direct detection of neutralinos in dark matter detectors. We first summarize the current developments using the cancellation mechanism which allows for the existence of large CP violating phases consistent with experimental limits on the electron and on the neutron electric dipole moments in a broad class of SUSY, string and D brane models. We then discuss their effects on the scattering of neutralinos from quarks and on the event rates. It is found that while CP effects on the event rates can be enormous such effects are reduced significantly with the imposition of the EDM constraints. However, even with the inclusion of the EDM constraints the effects are still very significant and should be included in a precision prediction of event rates in any SUSY, string or D brane model.Comment: Based on an invited talk at the conference "Sources and Detection of Dark Matter in the Universe", at Marina del Rey, CA, Feb. 23-25, 2000; 12 pages, Latex including 2 figure

Slepton Flavor Nonuniversality, the Muon EDM and its Proposed sensitive Search at Brookhaven

We analyze the electric dipole moment of the electron ($d_e$), of the neutron ($d_n$) and of the muon ($d_{\mu}$) using the cancellation mechanism in the presence of nonuniversalities of the soft breaking parameters. It is shown that the nonuniversalities in the slepton sector produce a strong violation of the scaling relation $d_{\mu}/d_e\simeq m_{\mu}/m_e$ in the cancellation region. An analysis of $d_e, d_n$ and $d_{\mu}$ under the constraints of the current experimental limits on $d_e$ and $d_n$ and under the constraints of the recent Brookhaven result on $g_{\mu}-2$ shows that in the non-scaling region $d_{\mu}$ can be as large as ($10^{-24}-10^{-23}$)ecm and thus within reach of the recently proposed Brookhaven experiment for a sensitive search for $d_{\mu}$ at the level of $10^{-24}$ ecm.Comment: 24 pages, Latex, including 5 figures with additional reference

Electromagnetic Couplings of Nucleon Resonances

An effective Lagrangian calculation of pion photoproduction including all nucleon resonances up to $\sqrt s = 1.7$ GeV is presented. We compare our results to recent calculations and show the influence of different width parametrizations and offshell cutoffs on the photoproduction multipoles. We determine the electromagnetic couplings of the resonances from a new fit to the multipole data.Comment: 20 pages, latex, 6 figures. Misprints corrected, text & 3 figures adde

Singlet ground state in the alternating spin-1/21/2 chain compound NaVOAsO4_4

We present the synthesis and a detailed investigation of structural and magnetic properties of polycrystalline NaVOAsO$_4$ by means of x-ray diffraction, magnetization, electron spin resonance (ESR), and $^{75}$As nuclear magnetic resonance (NMR) measurements as well as density-functional band structure calculations. Temperature-dependent magnetic susceptibility, ESR intensity, and NMR line shift could be described well using an alternating spin-$1/2$ chain model with the exchange coupling $J/k_{\rm B}\simeq 52$ K and an alternation parameter $\alpha \simeq 0.65$. From the high-field magnetic isotherm measured at $T=1.5$ K, the critical field of the gap closing is found to be $H_{\rm c}\simeq 16$ T, which corresponds to the zero-field spin gap of $\Delta_0/k_{\rm B}\simeq 21.4$ K. Both NMR shift and spin-lattice relaxation rate show an activated behavior at low temperatures, further confirming the singlet ground state. The spin chains do not coincide with the structural chains, whereas the couplings between the spin chains are frustrated. Because of a relatively small spin gap, NaVOAsO$_4$ is a promising compound for further experimental studies under high magnetic fields.Comment: 14 pages, 10 figures, 2 table

Raman anomalies as signatures of pressure induced electronic topological and structural transitions in black phosphorus: Experiments and Theory

We report high pressure Raman experiments of Black phosphorus up to 24 GPa. The line widths of first order Raman modes A$^1_g$, B$_{2g}$ and A$^2_g$ of the orthorhombic phase show a minimum at 1.1 GPa. Our first-principles density functional analysis reveals that this is associated with the anomalies in electron-phonon coupling at the semiconductor to topological insulator transition through inversion of valence and conduction bands marking a change from trivial to nontrivial electronic topology. The frequencies of B$_{2g}$ and A$^2_g$ modes become anomalous in the rhombohedral phase at 7.4 GPa, and new modes appearing in the rhombohedral phase show anomalous softening with pressure. This is shown to originate from unusual structural evolution of black phosphorous with pressure, based on first-principles theoretical analysis.Comment: 13pages, 12figure

Electron-Hole Asymmetry in the Electron-phonon Coupling in Top-gated Phosphorene Transistor

Using in-situ Raman scattering from phosphorene channel in an electrochemically top-gated field effect transistor, we show that its phonons with A$_g$ symmetry depend much more strongly on concentration of electrons than that of holes, while the phonons with B$_g$ symmetry are insensitive to doping. With first-principles theoretical analysis, we show that the observed electon-hole asymmetry arises from the radically different constitution of its conduction and valence bands involving $\pi$ and $\sigma$ bonding states respectively, whose symmetry permits coupling with only the phonons that preserve the lattice symmetry. Thus, Raman spectroscopy is a non-invasive tool for measuring electron concentration in phosphorene-based nanoelectronic devices