693 research outputs found
Components of Effective Leadership
[First paragraph] The effective schools literature demonstrates that the principal\u27s leadership is key to the revitalization of schools. The purpose of this article is to feature those components of leadership on which principals need to place attention and to provide suggested activities to enhance these components
Leadership Styles
[First paragraph] Effective schools literature shows clearly that the leadership of the principal is key to the effectiveness of the school (Hoy and Miskell, 1982, and Arnn and Mangieri, 1988). To be effective, principals must use leadership styles appropriate to the situation
Grievances
[First Paragraph] The Virginia Board of Education has adopted a procedure for resolving disputes concerning the application of local board policies, rules, and regulations as they impact the work or disciplinary actions of teachers. It is vital that the principal be aware of the process and the timeline involved in the grievance procedure since the solution should be secured at the lowest administrative level in the process. It is beyond the scope of this article to provide every detail of the grievance process. For a complete detailing of procedure, please refer to Chapter 15, Article 3, Sections 22.1-306 through 22.1-314 of the Code of Virginia
Virginia\u27s Plan for Dual Enrollment
[First paragraph] There is a plan where Virginia pays Average Daily Membership (ADM) monies to a school system for a student attending a community college - and the community college collects the Full Time Equivalency (FTE) from the State. Principals must be aware of this dual enrollment plan for secondary students with community colleges approved in September of 1988. This plan provides options for students which were not available before. Dual enrollment allows high school students to accumulate credits for graduation while simultaneously earning college credit. The courses to be offered are to be mutually agreed upon by the school division and the community college
Unit Plans
[First paragraph] Careful unit planning as a framework for daily lesson plans can help teachers individualize instruction, manage time and classroom behavior, bring cohesive-ness to a series of related daily lessons, and ultimately improve student achievement. Principals can help teachers by providing clear expectations and a consistent framework for unit planning. School and district philosophy will help determine the particular model chosen from the wide variety available. Following is one format
Relaxation kinetics of biological dimer adsorption models
We discuss the relaxation kinetics of a one-dimensional dimer adsorption
model as recently proposed for the binding of biological dimers like kinesin on
microtubules. The non-equilibrium dynamics shows several regimes: irreversible
adsorption on short time scales, an intermediate plateau followed by a
power-law regime and finally exponential relaxation towards equilibrium. In all
four regimes we give analytical solutions. The algebraic decay and the scaling
behaviour can be explained by mapping onto a simple reaction-diffusion model.
We show that there are several possibilities to define the autocorrelation
function and that they all asymptotically show exponential decay, however with
different time constants. Our findings remain valid if there is an attractive
interaction between bound dimers.Comment: REVTeX, 6 pages, 5 figures; to appear in Europhys. Letters; a Java
applet showing the simulation is accessible at
http://www.ph.tum.de/~avilfan/rela
A Degree-Scale Measurement of the Anisotropy in the Cosmic Microwave Background
We report the detection of anisotropy in the microwave sky at 3O GHz and at l deg angular scales. The most economical interpretation of the data is that the fluctuations are intrinsic to the cosmic microwave background. However, galactic free-free emission is ruled out with only 90% confidence. The most likely root-mean-squared amplitude of the fluctuations, assuming they are described by a Gaussian auto-correlation function with a coherence angle of 1.2 deg, is 41(+16/-13) (mu)K. We also present limits on the anisotropy of the polarization of the cosmic microwave background
Experimental study of viscous friction in undergraduate physics laboratory: introduction of phase diagrams to analyse dynamic equilibrium
In this work we propose using phase diagrams to explain the dynamical behaviour of simple mechanical systems. First the motion of the system x (t) is experimentally measured, and then the derivatives, v(t) and a(t), are obtained from it and the motion equation f (x, v, a) = 0 is represented graphically. This idea is applied to the study of a system with linear viscous drag, explaining the evolution of the system towards the dynamical equilibrium point corresponding to the limit velocity. The phase diagrams of the viscous drag are compared with those of the Coulomb drag, which is not continuous and does not necessarily lead to a uniformly accelerated motion. The method is illustrated by an experiment in a dynamic track with magnetic damping. The use of phase diagrams allows for the checking the linearity of this damping. Moreover it allows for the identification of the existence of a small Coulomb drag between the track and the cart that appears as a small discontinuity of the function a (v) when the direction of the movement changes.Moreno Cano, R.; Page Del Pozo, AF.; Riera Guasp, J.; Hueso Pagoaga, JL. (2015). Experimental study of viscous friction in undergraduate physics laboratory: introduction of phase diagrams to analyse dynamic equilibrium. European Journal of Physics. 36:1-15. doi:10.1088/0143-0807/36/3/035033S11536Larson, R. F. (1998). Measuring the coefficient of friction of a low-friction cart. The Physics Teacher, 36(8), 464-465. doi:10.1119/1.879928Paetkau, M., Bahniwal, M., & Gamblen, J. (2008). Magnetic Low-Friction Track. The Physics Teacher, 46(5), 307-309. doi:10.1119/1.2909753Takahashi, K., & Thompson, D. (1999). Measuring air resistance in a computerized laboratory. American Journal of Physics, 67(8), 709-711. doi:10.1119/1.19356Lindemuth, J. (1971). The Effect of Air Resistance on Falling Balls. American Journal of Physics, 39(7), 757-759. doi:10.1119/1.1986278Andereck, B. S. (1999). Measurement of air resistance on an air track. American Journal of Physics, 67(6), 528-533. doi:10.1119/1.19318Pantaleone, J., & Messer, J. (2011). The added mass of a spherical projectile. American Journal of Physics, 79(12), 1202-1210. doi:10.1119/1.3644334Feinberg, G. (1965). Fall of Bodies Near the Earth. American Journal of Physics, 33(6), 501-502. doi:10.1119/1.1971740Bohren, C. F. (2004). Dimensional analysis, falling bodies, and the fine art ofnotsolving differential equations. American Journal of Physics, 72(4), 534-537. doi:10.1119/1.1574042Moreno, R., Page, A., Riera, J., & Hueso, J. L. (2013). Experimental analysis of nonlinear oscillations in the undergraduate physics laboratory. European Journal of Physics, 35(1), 015005. doi:10.1088/0143-0807/35/1/015005Erlichson, H. (1983). Maximum projectile range with drag and lift, with particular application to golf. American Journal of Physics, 51(4), 357-362. doi:10.1119/1.13248Brancazio, P. J. (1985). Looking into Chapman’s homer: The physics of judging a fly ball. American Journal of Physics, 53(9), 849-855. doi:10.1119/1.14350Parker, G. W. (1977). Projectile motion with air resistance quadratic in the speed. American Journal of Physics, 45(7), 606-610. doi:10.1119/1.10812Page, A., Candelas, P., & Belmar, F. (2006). On the use of local fitting techniques for the analysis of physical dynamic systems. European Journal of Physics, 27(2), 273-279. doi:10.1088/0143-0807/27/2/010Shone, R. (2002). Economic Dynamics. doi:10.1017/cbo9781139165020Murray, J. D. (Ed.). (2002). Mathematical Biology. Interdisciplinary Applied Mathematics. doi:10.1007/b98868Van Buskirk, R., & Jeffries, C. (1985). Observation of chaotic dynamics of coupled nonlinear oscillators. Physical Review A, 31(5), 3332-3357. doi:10.1103/physreva.31.3332Siahmakoun, A., French, V. A., & Patterson, J. (1997). Nonlinear dynamics of a sinusoidally driven pendulum in a repulsive magnetic field. American Journal of Physics, 65(5), 393-400. doi:10.1119/1.18546Vidaurre, A., Riera, J., Monsoriu, J. A., & Giménez, M. H. (2008). Testing theoretical models of magnetic damping using an air track. European Journal of Physics, 29(2), 335-343. doi:10.1088/0143-0807/29/2/014Page, A., Moreno, R., Candelas, P., & Belmar, F. (2008). The accuracy of webcams in 2D motion analysis: sources of error and their control. European Journal of Physics, 29(4), 857-870. doi:10.1088/0143-0807/29/4/017Cadwell, L. H. (1996). Magnetic damping: Analysis of an eddy current brake using an airtrack. American Journal of Physics, 64(7), 917-923. doi:10.1119/1.1812
A study of the prompt and afterglow emission of the Short GRB 061201
Our knowledge of the intrinsic properties of short duration Gamma-Ray Bursts
has relied, so far, only upon a few cases for which the estimate of the
distance and an extended, multiwavelength monitoring of the afterglow have been
obtained. We carried out multiwavelength observations of the short GRB 061201
aimed at estimating its distance and studying its properties. We performed a
spectral and timing analysis of the prompt and afterglow emission and discuss
the results in the context of the standard fireball model. A clear temporal
break was observed in the X-ray light curve about 40 minutes after the burst
trigger. We find that the spectral and timing behaviour of the X-ray afterglow
is consistent with a jet origin of the observed break, although the optical
data can not definitively confirm this and other scenarios are possible. No
underlying host galaxy down to R~26 mag was found after fading of the optical
afterglow. Thus, no secure redshift could be measured for this burst. The
nearest galaxy is at z=0.111 and shows evidence of star formation activity. We
discuss the association of GRB 061201 with this galaxy and with the ACO S 995
galaxy cluster, from which the source is at an angular distance of 17'' and
8.5', respectively. We also test the association with a possible undetected,
positionally consistent galaxy at z~1. In all these cases, in the jet
interpretation, we find a jet opening angle of 1-2 degrees.Comment: 10 pages, 7 figures, accepted for publication in A&
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