493 research outputs found

    The Morphology External Organs Of The Body Of Bandicoot Echymipera Kalubu

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    Study on the morphology of external organs of the body of peroryctids is less available. Bandicoot  (Echymipera kalubu) is one of marsupial in peroryctids and is endemic species in Papua.  The morphological characteristic of the external organs of five adults bandicootS (E. kalubu)  with the body weight of 1,16 ± 0,29 kg and 38,2 ± 4,76 cm of body length were studied macroscopically. The external organs of the body of bandicoot were identified the eye, nose, limb and reproductive systems. The nose of the E. kalubu had tactile hairs on the trunk and the cheek under the eye. The ear of the E. kalubu had tragus. The forelimb which were shorter of the hind limb. The hind limb unique where only consisting of four toes and having five claws. The tail of the E. kalubu there was long but there were also species are not having tail. Uniqueness was also in the external organs of reproductive systems which there is only scortum, that out the abdomen of the body. The penis not found around skortum. The condition reproductive system of male E. kalubu like cloaca in poultry. The penis only will look when there was coitus. In a female has sac with the nipple. Keywords: Bandicoot, Echymipera kalubu, marsupialia, external organ

    Suspended liquid particle disturbance on laser-induced blast wave and low density distribution

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    The impurity effect of suspended liquid particles on the laser-induced gas breakdown was experimentally investigated in quiescent gas. The focus of this study is the investigation of the influence of the impurities on the shock wave structure as well as the low density distribution. A 532 nm Nd:YAG laser beam with an 188 mJ/pulse was focused on the chamber filled with suspended liquid particles 0.9 ± 0.63 μm in diameter. Several shock waves are generated by multiple gas breakdowns along the beam path in the breakdown with particles. Four types of shock wave structures can be observed: (1) the dual blast waves with a similar shock radius, (2) the dual blast waves with a large shock radius at the lower breakdown, (3) the dual blast waves with a large shock radius at the upper breakdown, and (4) the triple blast waves. The independent blast waves interact with each other and enhance the shock strength behind the shock front in the lateral direction. The triple blast waves lead to the strongest shock wave in all cases. The shock wave front that propagates toward the opposite laser focal spot impinges on one another, and thereafter a transmitted shock wave (TSW) appears. The TSW interacts with the low density core called a kernel; the kernel then longitudinally expands quickly due to a Richtmyer-Meshkov-like instability. The laser-particle interaction causes an increase in the kernel volume which is approximately five times as large as that in the gas breakdown without particles. In addition, the laser-particle interaction can improve the laser energy efficiency

    The shock wave ignition of dusts

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76923/1/AIAA-1984-205.pd

    Parity forbidden excitations of Sr2CuO2Cl2 revealed by optical third-harmonic spectroscopy

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    We present the first study of nonlinear optical third harmonic generation in the strongly correlated charge-transfer insulator Sr2CuO2Cl2. For fundamental excitation in the near-infrared, the THG spectrum reveals a strongly resonant response for photon energies near 0.7 eV. Polarization analysis reveals this novel resonance to be only partially accounted for by three-photon excitation to the optical charge-transfer exciton, and indicates that an even-parity excitation at 2 eV, with a_1g symmetry, participates in the third harmonic susceptibility.Comment: Requires RevTeX v4.0beta

    Liquid-crystal blazed-grating beam deflector

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    A transmission-type nonmechanical multiple-angle beam-steering device that uses liquid-crystal blazed grating has been developed. Sixteen steering angles with a contrast ratio of 18 has been demonstrated. A detailed analysis of the Liquid-crystal and poly(methyl methacrylate) blazed-grating deflector was carried out to provide guidance during the deflector's development. A manufacturing offset compensation technique is proposed to improve the device's performance greatly. A hybrid approach utilizing electrically generated blazed grating combined with the cascading approach described here yields in excess of 500 deflecting angles. (C) 2000 Optical Society of America OCIS codes: 050.1970, 230.3720, 230.2090, 050.1940

    Counter-propagating entangled photons from a waveguide with periodic nonlinearity

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    The conditions required for spontaneous parametric down-conversion in a waveguide with periodic nonlinearity in the presence of an unguided pump field are established. Control of the periodic nonlinearity and the physical properties of the waveguide permits the quasi-phase matching equations that describe counter-propagating guided signal and idler beams to be satisfied. We compare the tuning curves and spectral properties of such counter-propagating beams to those for co-propagating beams under typical experimental conditions. We find that the counter-propagating beams exhibit narrow bandwidth permitting the generation of quantum states that possess discrete-frequency entanglement. Such states may be useful for experiments in quantum optics and technologies that benefit from frequency entanglement.Comment: submitted to Phys. Rev.

    Mapping the dynamical regimes of a SESAM mode-locked VECSEL with long cavity using time series analysis

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    The different dynamical regions of an optically-pumped SESAM mode-locked, long-cavity VECSEL system with a fundamental pulse repetition frequency of ~200 MHz are investigated. The output power, captured as 250 μs long time series using a sampling rate of 200 GSa/s, for each operating condition of the system, is analyzed to determine the dynamical state. A wavelength range of 985-995 nm and optical pump powers of 10 W-16.3 W is studied. The system produces high quality fundamental passive mode-locking (FML) over an extensive part of the parameter space, but the different dynamical regions outside of FML are the primary focus of this study. We report five types of output: CW emission, FML, modelocking of a few modes, double pulsing, and, semi-stable 4th harmonic mode-locking. The high sampling rate of the oscilloscope, combined with the long duration of the time series analyzed, enables insight into how the structure and substructure of pulses vary systematically over thousands of round trips of the laser cavity. Higher average output power is obtained in regions characterized by semi-stable 4th harmonic mode-locking than observed for FML, raising whether such average powers might be achieved for FML. The observed dynamical transitions from fundamental mode-locking provide insights into instability challenges in developing a stable, widely tunable, low repetition rate, turn-key system; and to inform future modelling of the system

    Theory of four-wave mixing of matter waves from a Bose-Einstein condensate

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    A recent experiment [Deng et al., Nature 398, 218(1999)] demonstrated four-wave mixing of matter wavepackets created from a Bose-Einstein condensate. The experiment utilized light pulses to create two high-momentum wavepackets via Bragg diffraction from a stationary Bose-Einstein condensate. The high-momentum components and the initial low momentum condensate interact to form a new momentum component due to the nonlinear self-interaction of the bosonic atoms. We develop a three-dimensional quantum mechanical description, based on the slowly-varying-envelope approximation, for four-wave mixing in Bose-Einstein condensates using the time-dependent Gross-Pitaevskii equation. We apply this description to describe the experimental observations and to make predictions. We examine the role of phase-modulation, momentum and energy conservation (i.e., phase-matching), and particle number conservation in four-wave mixing of matter waves, and develop simple models for understanding our numerical results.Comment: 18 pages Revtex preprint form, 13 eps figure
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