5,791 research outputs found

    Chimera states: The Existence Criteria Revisited

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    Chimera states, representing a spontaneous break-up of a population of identical oscillators that are identically coupled, into sub-populations displaying synchronized and desynchronized behavior, have traditionally been found to exist in weakly coupled systems and with some form of nonlocal coupling between the oscillators. Here we show that neither the weak-coupling approximation nor nonlocal coupling are essential conditions for their existence. We obtain for the first time amplitude-mediated chimera states in a system of globally coupled complex Ginzburg-Landau oscillators. We delineate the dynamical origins for the formation of such states from a bifurcation analysis of a reduced model equation and also discuss the practical implications of our discovery of this broader class of chimera states.Comment: 5 pages, 5 figure

    Study of fragmentation and momentum correlations in heavy-ion collisions

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    The role of momentum correlations is studied in the production of light and medium mass fragments by imposing momentum cut in clusterization the phase space. Our detailed investigation shows that momentum cut has major role to play in the emission of fragments.Comment: 16 pages, 7 figure

    Stability of networks of delay-coupled delay oscillators

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    Dynamical networks with time delays can pose a considerable challenge for mathematical analysis. Here, we extend the approach of generalized modeling to investigate the stability of large networks of delay-coupled delay oscillators. When the local dynamical stability of the network is plotted as a function of the two delays then a pattern of tongues is revealed. Exploiting a link between structure and dynamics, we identify conditions under which perturbations of the topology have a strong impact on the stability. If these critical regions are avoided the local stability of large random networks can be well approximated analytically

    CP Violation and Flavour Mixings in Orbifold GUTs

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    We address the flavour problem by incorporating the hypothesis of universal strength of Yukawa couplings in the framework of a 5D GUT model compactified on an S1/(Z2×Z2′)S^1/(Z_2 \times Z_2^{\prime}) orbifold. We show that a quantitatively successful picture of fermion masses and mixings emerges from the interplay between the bulk suppression factors of geometric origin and the phases of the Yukawa matrices. We give an explicit example, where we obtain a good fit for both the CKM and PMNS matrices.Comment: 8 pages, no figures; v2: minor changes, published in Phys Rev D (Rapid Communication

    On the Balance of Intercalation and Conversion Reactions in Battery Cathodes

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    We present a thermodynamic analysis of the driving forces for intercalation and conversion reactions in battery cathodes across a range of possible working ion, transition metal, and anion chemistries. Using this body of results, we analyze the importance of polymorph selection as well as chemical composition on the ability of a host cathode to support intercalation reactions. We find that the accessibility of high energy charged polymorphs in oxides generally leads to larger intercalation voltages favoring intercalation reactions, whereas sulfides and selenides tend to favor conversion reactions. Furthermore, we observe that Cr-containing cathodes favor intercalation more strongly than those with other transition metals. Finally, we conclude that two-electron reduction of transition metals (as is possible with the intercalation of a 2+2+ ion) will favor conversion reactions in the compositions we studied

    Operation of Induction Motor Open-delta Transformer Banks

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    Induction motors and transformers are among the earliest electrical equipment to be manufactured. The squirrel-cage induction motor has been studied very widely from the time of Tesla and Ferraris in 1889. The operation of a squirrel-cage induction motor with an unbalanced supply voltage has also been studied in great detail. Yet there is little mention of an induction motor operating on an open-delta or vee-connected transformer bank in textbooks. The open-delta transformer connection is the equivalent of the delta-delta connection with one transformer removed. The vee-connection is equivalent to a star-delta connection with one transformer removed; the primary neutral must be connected. However, both of these connections behave identically as far as the output is concerned. Hence, as a general term open-delta will be used throughout the discussion. Open-delta connections are used in emergencies where one of a group of three delta-delta connected transformers becomes defective and has to be removed from service. The remaining two transformers transmit three-phase power with a reduced load capacity. Such connections are also used in areas where the load is expected to increase. A third transformer can be readily added converting the open-delta to a delta-delta or wye-delta, thereby increasing the load ca pa city. Open-delta transformer banks are quite commonly used by rural electric co-operatives. It is cheaper to install an open-wye open-delta bank. The loads are often house-hold loads, small motors, and seasonal pumps; the slight unbalance introduced due to an open-delta secondary is usually not serious. Open-delta transformer banks, as can be seen, are used to supply three-phase induction motors. However, due to the lack of sufficient published works and detailed studies, there may be a substantial waste in transformers and/or motor capacity. The author, therefore, chose to investigate the development of an equivalent circuit for an induction motor supplied by an open-delta transformer bank, and to study the performance of the induction motor. Finally, a family of curves was developed for easy evaluation of the voltage unbalance factor. Unbalance factor plays an important part in determining the performance of the motor operating under unbalanced voltage conditions. Unbalance factor is defined as the ratio of the negative to positive-sequence voltage

    Draft genome sequence of the naturally competent Bacillus simplex strain WY10

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    ABSTRACT We sequenced a naturally competent bacterial isolate, WY10, cultured from a Wyoming soil sample. Sequence analysis revealed that WY10 is a novel strain of Bacillus simplex . To our knowledge, WY10 is the first B. simplex strain to be characterized as naturally competent for DNA uptake by transformation. </jats:p

    Mistakes, Miscalculations and the Search for Middle Ground: An Exit Strategy for Nepal

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    Although he may have had good intentions, King Gyanendra miscalculated the effect of his draconian measures on February 1, 2005. The King and his advisors miscalculated the capacity of the military, the response from the international community, the effectiveness of loyalists, the appeal to Hindus, the role of China, as well as attitudes towards corruption and censorship. In order to return to a democratic path, a path that is also the only viable option for the survival of the constitutional monarchy, Nepals three political protagonists — the King, the Maoists, and the political parties — must compromise. An exit strategy is possible, but it requires that these three protagonists put the interests of Nepal above their own narrow, parochial interests.\u2
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