86,143 research outputs found

    Design of Prototype Dynamic Ac Power Machine with Equivalent Circuit Modeling (Torque Speed Curve of Induction Motor 1,1, Kw)

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    Squirrel cage induction motors are widely used in electric motor drives due to their satisfactory mechanical characteristics (torque, current, overloading) and small dimensions, as well as their low price. When starting an induction motor, a large current is required for magnetizing its core, which results in a low power factor, rotor power losses and a temperature rise in the windings. None of these parameters should reach values beyond certain limits until the motor reaches nominal speed. The speed of an induction motor 1,1kW is affected very little by fluctuations of voltage. The greater the supply voltage of the motor, the induction motor's speed will increase. The torque values (Tstart, TSmax and Tmax) are affected by the value of the motor supply voltage: (Vp-nl : 132.8, Tstart1 : 7.4, T S-max1 : 0.4, Tmax1 : 9.9) V, (Vp-nl : 127.0, Tstart2 : 4.8, T S-max1 : 0.3, Tmax1 : 8.4) V and (Vp-nl : 121.3, Tstart3 : 3.3, T S-max3 : 0.2, Tmax3 : 7.1) V. Stator current (IL-nl ; 2.5, 2.2, 1.9 ) Amp rises gradually on account of the increase in magnetising current (Im : 2.5, 2.2, 1.9) Amp. The magnetising current required to produce the stator flux. The component of the stator current which provides the ampere-turns balancing the rotor ampere-turns will steadily diminish as the rotor current (IL-nl) decrease with the increase in rotor speed (nr).&nbsp

    Symmetry of Endomorphism Algebras

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    Motivated by recent problems regarding the symmetry of Hecke algebras, we investigate the symmetry of the endomorphism algebra EP(M)E_P(M) for PP a pp-group and MM a kPkP-module with kk a field of characteristic pp. We provide a complete analysis for cyclic pp-groups and the dihedral 2-groups. For the dihedral 2-groups, this requires the classification of the indecomposable modules in terms of string modules and band modules. We generalize our techniques to consider EΛ(M)E_{\Lambda}(M) for Λ\Lambda a Nakayama algebra, a local algebra, or even an arbitrary algebra.Comment: Submitted to journal for publicatio

    Integrable subsystem of Yang--Mills dilaton theory

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    With the help of the Cho-Faddeev-Niemi-Shabanov decomposition of the SU(2) Yang-Mills field, we find an integrable subsystem of SU(2) Yang-Mills theory coupled to the dilaton. Here integrability means the existence of infinitely many symmetries and infinitely many conserved currents. Further, we construct infinitely many static solutions of this integrable subsystem. These solutions can be identified with certain limiting solutions of the full system, which have been found previously in the context of numerical investigations of the Yang-Mills dilaton theory. In addition, we derive a Bogomolny bound for the integrable subsystem and show that our static solutions are, in fact, Bogomolny solutions. This explains the linear growth of their energies with the topological charge, which has been observed previously. Finally, we discuss some generalisations.Comment: 25 pages, LaTex. Version 3: appendix added where the equivalence of the field equations for the full model and the submodel is demonstrated; references and some comments adde

    Selling packaged software: an ethical analysis

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    Within the IS literature there is little discussion on selling software products in general and especially from the ethical point of view. Similarly, within computer ethics, although there is much interest in professionalism and professional codes, in terms of accountability and responsibility, the spotlight tends to play on safety-critical or life-critical systems, rather than on software oriented towards the more mundane aspects of work organisation and society. With this research gap in mind, we offer a preliminary ethical investigation of packaged software selling. Through an analysis of the features of competition in the market, the global nature of the packaged software market and the nature of product development we conclude that professionalism, as usually conceived in computer ethics, does not apply particularly well to software vendors. Thus, we call for a broader definition of professionalism to include software vendors, not just software developers. Moreover, we acknowledge that with intermediaries, such as implementation consultants, involved in software selling, and the packaged software industry more generally, there are even more “hands” involved. Therefore, we contend that this is an area worthy of further study, which is likely to yield more on the question of accountability

    Magnetoconductance of the Corbino disk in graphene

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    Electron transport through the Corbino disk in graphene is studied in the presence of uniform magnetic fields. At the Dirac point, we observe conductance oscillations with the flux piercing the disk area Φd\Phi_d, characterized by the period Φ0=(2h/e)ln(Ro/Ri)\Phi_0=(2h/e)\ln(R_o/R_i), where RoR_o (RiR_i) is the outer (inner) disk radius. The oscillations magnitude increase with the radii ratio and exceed 10% of the average conductance for Ro/Ri5R_o/R_i\geqslant 5 in the case of the normal Corbino setup, or for Ro/Ri2.2R_o/R_i\geqslant 2.2 in the case of the Andreev-Corbino setup. At a finite but weak doping, the oscillations still appear in a limited range of ΦdΦdmax|\Phi_d|\leqslant\Phi_d^{max}, away from which the conductance is strongly suppressed. At large dopings and weak fields we identify the crossover to a normal ballistic transport regime.Comment: RevTeX, 5 pages, 3 figures. New version with minor revisions and references added; to be published in Phys. Rev.

    Dampak Perubahan Status Badan USAha CV Menjadi Badan Hukum PT terhadap Perjanjian Kredit yang Sedang Berjalan (Studi pada Bank Bni)

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    If the credit applied by the businessmen is big enough, the bank will ask for a certain amount of movable or unmovable collateral to meet the requirements for the credit extension, besides it can also change the form of business entity from unincorporated into incorporated enterprises.The change from comanditer company (CV) into a legal business entity such as limiuted liability company (PT) against the ongoing credit agreement shall begin with the renewal of credit agreement from previous debtor (CV) to current debtor (PT) resulting in a novation (debt renewal) with a number of additional requirements such as the addition of the collateral previously given. The collateral previously given on behalf of CV shall be cancelled with the agreement of Bank BNI and is transfered on behalf of PT as current/new debtor through a General Meeting of Stockholders

    Topological energy bounds in generalized Skyrme models

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    The Skyrme model has a natural generalization amenable to a standard hamiltonian treatment, consisting of the standard sigma model and the Skyrme terms, a potential, and a certain term sextic in first derivatives. Here we demonstrate that, in this theory, each pair of terms in the static energy functional which may support topological solitons according to the Derrick criterion (i.e., each pair of terms with opposite Derrick scaling) separately posesses a topological energy bound. As a consequence, there exists a four-parameter family of topological bounds for the full generalized Skyrme model. The optimal bounds, i.e., the optimal values of the parameters, depend both on the form of the potential and on the relative strength of the different terms. It also follows that various submodels of the generalized Skyrme model have one-parameter families of topological energy bounds. We also consider the case of topological bounds for the generalized Skyrme model on a compact base space as well as generalizations to higher dimensions.Comment: Latex, 26 pages, version accepted for publication in PRD, presentation and motivation slightly changed, references added, results unchange

    Gauged BPS baby Skyrmions with quantised magnetic flux

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    A new type of gauged BPS baby Skyrme model is presented, where the derivative term is just the Schroers current (i.e., gauge invariant and conserved version of the topological current) squared. This class of models has a topological bound saturated for solutions of the pertinent Bogomolnyi equations supplemented by a so-called superpotential equation. In contrast to the gauged BPS baby Skyrme models considered previously, the superpotential equation is linear and, hence, completely solvable. Furthermore, the magnetic flux is quantized in units of 2π2\pi, which allows, in principle, to define this theory on a compact manifold without boundary, unlike all gauged baby Skyrme models considered so far.Comment: Latex, 17 page

    Theory of anharmonically modified Coriolis coupling in the S1 state of benzene and relation to experiment

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    Avoided crossings between quasidegenerate rovibrational states in the Doppler-free two-photon excitation of the 141 mode in the S1 excited state of benzene are treated theoretically. Two sets of avoided crossings in plots of spectral line frequency vs J at a given K and DeltaK have been reported experimentally between an initially prepared "light" state (141 in zeroth order) and dark states, namely, one which in zeroth order is a 51101161 state, the other being in zeroth order a 62111 and/or possibly a 31161 state, implicated earlier by Neusser et al. The identification of these states makes the phenomenon an excellent candidate for treatment of the avoided crossing via a Van Vleck transformation, no other basis set states being needed for the diagonalization in order to extract the important features. Two successive transformations are used for handling direct coupling and coupling via virtual states. The dominant calculated contribution to the coupling is, jointly, Coriolis plus cubic–cubic anharmonic interactions between vibrational modes.Playing less of a role are Coriolis terms in which the inverse moment of inertia tensor is expanded up to quadratic terms in the coordinates. There results a 5×5 (for coupling to 51101161 ) and a 3×3 (for coupling to 62111 or 31161 ) matrix of the transformed Hamiltonian, each of which can also be described, if desired, to a very good approximation by a 2×2 matrix. The coupling element V0 and the difference of the rotational constants for the light and dark states (DeltaB) are obtained from the plots of line position vs J(J+1) obtained. For the 141 to 51101161 and for the 141 to 62111 couplings the theoretical results are in reasonable agreement with the experimental results, no adjustable parameters being employed. For a coupling of 141 to 31161 the calculated V0 would be much too high compared with experiment (a factor of 10), the coupling involving the exchange of only three instead of four vibrational quanta. A situation in which the 141 state is coupled to the 62111 state to yield an avoided crossing and off-resonantly coupled to the 31161 state would be consistent with some experimental results and not affect the reasonable agreement of the slope difference and splitting for the avoided crossing plots
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