2,874 research outputs found

    Web based learning on KBSM chemical formulae incorporating selected multiple intelligences

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    Vision 2020 aspires our nation to establish a progressive and resourceful society that is able to contribute to the scientific and technological civilisation of the future. One of the strategies to achieve this aspiration would be through the system of education whereby web based learning would be a good platform to begin with. The aim of this project is to develop a website for KBSM Chemistry Form Four for the subtopic Chemical Formulae, which is under the topic Chemical Formulae and Equations, Chapter 3. The aim of this website is to provide a web based learning platform for students to learn Chemical Formulae. The theory of Multiple Intelligences has been incorporated in the development of this website. However, only four multiple intelligences are selected in delivering the learning contents. The four intelligences selected are Verbal Linguistics, Logical Mathematical, Visual Spatial and Interpersonal. The Hannafin & Peck Model was adapted throughout the development process, which includes Needs Assessment, Design and Development/ Implementation Phase. Evaluation was carried out simultaneously during all three phases of development. The primary software used in developing this website is Microsoft Office Frontpage. Integration of multimedia elements such as graphics, video and animation are used to enhance the process of learning. It is hoped that this website would benefit students with the selected four intelligences at an optimum level in learning Chemical Formulae

    Non-Local Matrix Generalizations of W-Algebras

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    There is a standard way to define two symplectic (hamiltonian) structures, the first and second Gelfand-Dikii brackets, on the space of ordinary linear differential operators of order mm, L=−dm+U1dm−1+U2dm−2+
+UmL = -d^m + U_1 d^{m-1} + U_2 d^{m-2} + \ldots + U_m. In this paper, I consider in detail the case where the UkU_k are n×nn\times n-matrix-valued functions, with particular emphasis on the (more interesting) second Gelfand-Dikii bracket. Of particular interest is the reduction to the symplectic submanifold U1=0U_1=0. This reduction gives rise to matrix generalizations of (the classical version of) the {\it non-linear} WmW_m-algebras, called Vm,nV_{m,n}-algebras. The non-commutativity of the matrices leads to {\it non-local} terms in these Vm,nV_{m,n}-algebras. I show that these algebras contain a conformal Virasoro subalgebra and that combinations WkW_k of the UkU_k can be formed that are n×nn\times n-matrices of conformally primary fields of spin kk, in analogy with the scalar case n=1n=1. In general however, the Vm,nV_{m,n}-algebras have a much richer structure than the WmW_m-algebras as can be seen on the examples of the {\it non-linear} and {\it non-local} Poisson brackets of any two matrix elements of U2U_2 or W3W_3 which I work out explicitly for all mm and nn. A matrix Miura transformation is derived, mapping these complicated second Gelfand-Dikii brackets of the UkU_k to a set of much simpler Poisson brackets, providing the analogue of the free-field realization of the WmW_m-algebras.Comment: 43 pages, a reference and a remark on the conformal properties for U1≠0U_1\ne 0 adde

    Multi-Component KdV Hierarchy, V-Algebra and Non-Abelian Toda Theory

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    I prove the recently conjectured relation between the 2×22\times 2-matrix differential operator L=∂2−UL=\partial^2-U, and a certain non-linear and non-local Poisson bracket algebra (VV-algebra), containing a Virasoro subalgebra, which appeared in the study of a non-abelian Toda field theory. Here, I show that this VV-algebra is precisely given by the second Gelfand-Dikii bracket associated with LL. The Miura transformation is given which relates the second to the first Gelfand-Dikii bracket. The two Gelfand-Dikii brackets are also obtained from the associated (integro-) differential equation satisfied by fermion bilinears. The asymptotic expansion of the resolvent of (L−Ο)Κ=0(L-\xi)\Psi=0 is studied and its coefficients RlR_l yield an infinite sequence of hamiltonians with mutually vanishing Poisson brackets. I recall how this leads to a matrix KdV hierarchy which are flow equations for the three component fields T,V+,V−T, V^+, V^- of UU. For V±=0V^\pm=0 they reduce to the ordinary KdV hierarchy. The corresponding matrix mKdV equations are also given, as well as the relation to the pseudo- differential operator approach. Most of the results continue to hold if UU is a hermitian n×nn\times n-matrix. Conjectures are made about n×nn\times n-matrix mthm^{\rm th}-order differential operators LL and associated V(n,m)V_{(n,m)}-algebras.Comment: 20 pages, revised: several references to earlier papers on multi-component KdV equations are adde

    Two Dimensional Quantum Dilaton Gravity and the Positivity of Energy

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    Using an argument due to Regge and Teitelboim, an expression for the ADM mass of 2d quantum dilaton gravity is obtained. By evaluating this expression we establish that the quantum theories which can be written as a Liouville-like theory, have a lower bound to energy, provided there is no critical boundary. This fact is then reconciled with the observation made earlier that the Hawking radiation does not appear to stop. The physical picture that emerges is that of a black hole in a bath of quantum radiation. We also evaluate the ADM mass for the models with RST boundary conditions and find that negative values are allowed. The Bondi mass of these models goes to zero for large retarded times, but becomes negative at intermediate times in a manner that is consistent with the thunderpop of RST.Comment: 16 pages, phyzzx, COLO-HEP-309. (Confusing points in previous version clarified, discussion of ADM and Bondi masses in RST case added.

    A method for assessing the success and failure of community-level interventions in the presence of network diffusion, social reinforcement, and related social effects

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    Prevention and intervention work done within community settings often face unique analytic challenges for rigorous evaluations. Since community prevention work (often geographically isolated) cannot be controlled in the same way other prevention programs and these communities have an increased level of interpersonal interactions, rigorous evaluations are needed. Even when the `gold standard' randomized control trials are implemented within community intervention work, the threats to internal validity can be called into question given informal social spread of information in closed network settings. A new prevention evaluation method is presented here to disentangle the social influences assumed to influence prevention effects within communities. We formally introduce the method and it's utility for a suicide prevention program implemented in several Alaska Native villages. The results show promise to explore eight sociological measures of intervention effects in the face of social diffusion, social reinforcement, and direct treatment. Policy and research implication are discussed.Comment: 18 pages, 5 figure

    Methods and Models for Metabolic Assessment in Mice

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    The development of new therapies for the treatment of type 2 diabetes requires robust, reproducible and well validated in vivo experimental systems. Mice provide the most ideal animal model for studies of potential therapies. Unlike larger animals, mice have a short gestational period, are genetically similar, often give birth to many offspring at once and can be housed as multiple groups in a single cage. The mouse model has been extensively metabolically characterized using different tests. This report summarizes how these tests can be executed and how arising data are analyzed to confidently determine changes in insulin resistance and insulin secretion with high reproducibility. The main tests for metabolic assessment in the mouse reviewed here are the glucose clamp, the intravenous and the oral glucose tolerance tests. For all these experiments, including some commonly adopted variants, we describe: (i) their performance; (ii) their advantages and limitations; (iii) the empirical formulas and mathematical models implemented for the analysis of the data arising from the experimental procedures to obtain reliable measurements of peripheral insulin sensitivity and beta cell function. Finally, a list of previous applications of these methods and analytical techniques is provided to better comprehend their use and the evidences that these studies yielded

    Classical A_n--W-Geometry

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    This is a detailed development for the AnA_n case, of our previous article entitled "W-Geometries" to be published in Phys. Lett. It is shown that the AnA_n--W-geometry corresponds to chiral surfaces in CPnCP^n. This is comes out by discussing 1) the extrinsic geometries of chiral surfaces (Frenet-Serret and Gauss-Codazzi equations) 2) the KP coordinates (W-parametrizations) of the target-manifold, and their fermionic (tau-function) description, 3) the intrinsic geometries of the associated chiral surfaces in the Grassmannians, and the associated higher instanton- numbers of W-surfaces. For regular points, the Frenet-Serret equations for CPnCP^n--W-surfaces are shown to give the geometrical meaning of the AnA_n-Toda Lax pair, and of the conformally-reduced WZNW models, and Drinfeld-Sokolov equations. KP coordinates are used to show that W-transformations may be extended as particular diffeomorphisms of the target-space. This leads to higher-dimensional generalizations of the WZNW and DS equations. These are related with the Zakharov- Shabat equations. For singular points, global Pl\"ucker formulae are derived by combining the AnA_n-Toda equations with the Gauss-Bonnet theorem written for each of the associated surfaces.Comment: (60 pages
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