5,912 research outputs found

    Nonlinear resonance absorption in laser-cluster interaction

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    Rare gas or metal clusters are known to absorb laser energy very efficiently. Upon cluster expansion the Mie plasma frequency may become equal to the laser frequency. This linear resonance has been well studied both experimentally and theoretically employing pump probe schemes. In this work we focus on the few-cycle regime or the early stage of the cluster dynamics where linear resonance is not met but nevertheless efficient absorption of laser energy persists. By retrieving time-dependent oscillator frequencies from particle-in-cell simulation results, we show that nonlinear resonance is the dominant mechanism behind outer ionization and energy absorption in near infrared laser-driven clusters.Comment: 4 pages, 4 figures, REVTeX, minor modifications according to referee comments, accepted for publication in Phys. Rev. Let

    Yang-Baxter algebra and generation of quantum integrable models

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    An operator deformed quantum algebra is discovered exploiting the quantum Yang-Baxter equation with trigonometric R-matrix. This novel Hopf algebra along with its q1q \to 1 limit appear to be the most general Yang-Baxter algebra underlying quantum integrable systems. Three different directions of application of this algebra in integrable systems depending on different sets of values of deforming operators are identified. Fixed values on the whole lattice yield subalgebras linked to standard quantum integrable models, while the associated Lax operators generate and classify them in an unified way. Variable values construct a new series of quantum integrable inhomogeneous models. Fixed but different values at different lattice sites can produce a novel class of integrable hybrid models including integrable matter-radiation models and quantum field models with defects, in particular, a new quantum integrable sine-Gordon model with defect.Comment: 13 pages, revised and bit expanded with additional explanations, accepted for publication in Theor. Math. Phy

    Coke Oven Emission Standards - A Comparative Assessment

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    In USA, Clean Air Act(CAA) came into existence from 1963 onwards. Consent decrees, state implementation plans and Occupational Safety and Health Administration(OSHA) regulations were put in vogue for coke oven emissions in 1970s. These were different for different batteries. Progressively charging practices were changed and many developments were also carried in door, lid, and off-take arrangements. Extensive research (both technical and financial) was carried out for the development of regul-atory alternatives in 1980s. Finally CAAA-1990 came into extistence after lot of negotiations. Whereas in India, there were almost no standards (except CO and particulate matter emissions) existed before 1997. The philosophy behind the new standards is new to coke oven designers, suppliers, builders and operators. The environmental aspects so far remained focused on the ear-lier standards only. Adapting new concept would take time for all the players in the industry. The paper elaborates the methodology adopted for evaluation of coke oven emi-ssion standards in USA with respect to the same followed in India and at the end comes out with a proposal for acceptance by the Regulatory Authorities

    Seed yield of linseed varieties grown as ‘paira’ crop as influenced by dates of sowing

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    Linseed is an industrial crop cultivated for its seeds, fibres and oil purpose. Linseed crop can met their requirement i.e. moisture and nutritional demand from stored soil moisture and residual fertility status in "utera? or "paira? system of cropping. On the basis of this fact an experiment was conducted on “Seed yield of linseed varieties grown as paira crop as influenced by dates of sowing” in red and laterite zone of West Bengal during rabi season of 2012-13 and 2013-14 at Rice Research Station, Bankura, West Bengal, India. Poor in organic matter content, available phosphate and bases, hard structure of iron and aluminium patterned as honeycomb are present in the subsurface regions of the profiles and kaolinite is the predominant clay minerals of red and lateritic zone (western part) of West Bengal. This experiment was laid out in a split-plot design with three replications and compared two factors (dates of sowing and linseed varieties). Objective was identifying the optimum date of sowing and suitable linseed varieties grown as „paira? crop under changed climate in red and laterite zone of West Bengal. The experimental results revealed that the highest seed yield (534 kg ha-1 as pooled value) was recorded from the treatment D1 i.e. linseed sown on 15th November. The lowest seed yield (489.2 kg ha-1 as pooled value) was obtained with treatment D3 i.e. linseed sown on 29th November. Among linseed varieties, T-397 has yielded highest seed yield (573.4 kg ha-1 as pooled value). Lowest seed yield (409. 3 kg ha-1 as pooled data) was recorded from Neela variety. From the present study it may be concluded that linseed sown on 15th November is the best time and T-397 is the suitable linseed variety grown as "paira? crop under changed climate in red and laterite zone of West Bengal

    Effects of non-denumerable fixed points in finite dynamical systems

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    The motion of a spinning football brings forth the possible existence of a whole class of finite dynamical systems where there may be non-denumerably infinite number of fixed points. They defy the very traditional meaning of the fixed point that a point on the fixed point in the phase space should remain there forever, for, a fixed point can evolve as well! Under such considerations one can argue that a free-kicked football should be non-chaotic.Comment: This paper is a replaced version to modify the not-so-true claim, made unknowingly in the earlier version, of being first to propose the peculiar dynamical systems as described in the paper. With respect to the original workers, we present here our original finding
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