2,141 research outputs found

    On the simpleness of zeros of Stokes multipliers

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    The aim of this paper is to discuss the simpleness of zeros of Stokes multipliers associated with the differential equation −Φ′′(X)+W(X)Φ(X)=0-\Phi''(X) + W(X)\Phi(X) =0, where W(X)=Xm+a1Xm−1+...+am W(X) = X^{m} +a_{1}X^{m-1}+... +a_{m} is a real monic polynomial. We show that, under a suitable hypothesis on the coefficients aka_k, all the zeros of the Stokes multipliers are simple

    Acoustic bubble removal method

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    A method is described for removing bubbles from a liquid bath such as a bath of molten glass to be used for optical elements. Larger bubbles are first removed by applying acoustic energy resonant to a bath dimension to drive the larger bubbles toward a pressure well where the bubbles can coalesce and then be more easily removed. Thereafter, submillimeter bubbles are removed by applying acoustic energy of frequencies resonant to the small bubbles to oscillate them and thereby stir liquid immediately about the bubbles to facilitate their breakup and absorption into the liquid

    A new root-knot nematode, Meloidogyne moensi n. sp. (Nematoda : Meloidogynidae), parasitizing Robusta coffee from Western Highlands, Vietnam

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    A new root-knot nematode, parasitizing Robusta coffee in Dak Lak Province, Western Highlands of Vietnam, is described as Meloidogyne moensi n. sp. Morphological and molecular analyses demonstrated that this species differs clearly from other previously described root-knot nematodes. Morphologically, the new species is characterized by a swollen body of females with a small posterior protuberance that elongated from ovoid to saccate; perineal patterns with smooth striae, continuous and low dorsal arch; lateral lines marked as a faint space or linear depression at junction of the dorsal and ventral striate; distinct phasmids; perivulval region free of striae; visible and wide tail terminus surrounding by concentric circles of striae; medial lips of females in dumbbell-shaped and slightly raised above lateral lips; female stylet is normally straight with posteriorly sloping stylet knobs; lip region of second stage juvenile (J2) is not annulated; medial lips and labial disc of J2 formed dumbbell shape; lateral lips are large and triangular; tail of J2 is conoid with rounded unstriated tail tip; distinct phasmids and hyaline; dilated rectum. Meloidogyne moensi n. sp. is most similar to M. africana, M. ottersoni by prominent posterior protuberance. Results of molecular analysis of rDNA sequences including the D2-D3 expansion regions of 28S rDNA, COI, and partial COII/16S rRNA of mitochondrial DNA support for the new species status

    The dynamics of free liquid drops

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    The behavior of rotating and oscillating free liquid drops was studied by many investigators theoretically for many years. More recent numerical treatments have yielded predictions which are yet to be verified experimentally. The purpose is to report the results of laboratory work as well as that of the experiments carried out in space during the flight of Spacelab 3, and to compare it with the existing theoretical studies. Ground-based experiments were attempted as a first approximation to the ideal boundary conditions used by the theoretical treatments by neutralizing the overwhelming effects of the Earth's gravitational field with an outside supporting liquid and with the use of levitation technology. The viscous and inertial loading of such a suspending fluid was found to profoundly effect the results, but the information thus gathered has emphasized the uniqueness of the experimental data obtained in the low-gravity environment of space

    Design of scalar functional observers of order less than (v-1)

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    This paper presents a new method of designing scalar functional observers of order less than the well-known upper bound (&nu; - 1). A condition for the existence of observers of order p where 1 &le; p &le; (&nu; - 1) is given. A simple and effective algorithm for solving the constrained generalized Sylvester equation is proposed. Several numerical examples are given to illustrate the attractiveness of the design algorithm. <br /

    selective dissolution of woody biomass under hydrothermal conditions

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    Abstract This study analyzes semi-continuous hydrothermal hydrolysis of lignocellulosic biomass operating between 200°C and 300°C with constant inlet water flow rate. Experiments were executed in a novel reactor system that offered a nearly linear temperature behavior during the heating period with heating rates between 40°C/min and 60 °C/min and a nearly flat temperature profile during retention. Experimental results suggest that conversion efficiency improved at higher temperatures. After completion of the batch, solid and liquid products were collected and mass balance closures reached an average of 89%. It was discovered that, regardless of the temperature, a minimum of 90% of the total dissolution occurs within the first 15 minutes of the reaction. This work identifies various stages and conditions that favor the dissolution of certain components (hemicellulose, cellulose or lignin)

    Nonlinear Pseudo-Supersymmetry in the Framework of N-fold Supersymmetry

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    We recall the importance of recognizing the different mathematical nature of various concepts relating to PT-symmetric quantum theories. After clarifying the relation between supersymmetry and pseudo-supersymmetry, we prove generically that nonlinear pseudo-supersymmetry, recently proposed by Sinha and Roy, is just a special case of N-fold supersymmetry. In particular, we show that all the models constructed by these authors have type A 2-fold supersymmetry. Furthermore, we prove that an arbitrary one-body quantum Hamiltonian which admits two (local) solutions in closed form belongs to type A 2-fold supersymmetry, irrespective of whether or not it is Hermitian, PT-symmetric, pseudo-Hermitian, and so on.Comment: 10 pages, no figures; typos correcte
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