4,775 research outputs found
Study to determine peening stress profile of rod peened aluminum structural alloys versus shot peened material
The objective of this program was to determine the peening stress profiles of rod peened aluminum structural alloys versus shot peened material to define the effective depth of the compressed surface layer
El género Porphyra (Bangiaceae, Rhodophyta) en la costa Pacífico de México. I. Porphyra suborbiculata Kjellman
Porphyra suborbiculata Kjellman (Bangiaceae, Rhodophyta) is described with detail for the Pacific coast of Mexico, where was recently recorded, based on samples collected from western coast of Baja California between 1985 and 2001. We describe details of vegetative and reproductive morpho-anatomic characters of the thallus, as well as habitat and distribution on the Baja California coast.Se presenta una descripción extensa de Porphyra suborbiculata Kjellman (Bangiaceae, Rhodophyta), specierecientemente registrada para la costa del Pacífico de México, con base en material recolectado en la costaoccidental de Baja California, durante 1985-2001. Se describen en forma detallada los caracteres morfo-anatómicos y estructuras reproductoras de los talos; así como su hábitat y distribución en la costa de Baja California
Minimal open sets on generalized topological space
We introduce the notion of minimal open sets in a generalized topological space (X μ). We investigate some of their fundamental properties and proved that any subset of a minimal open set on a GTS (X μ) is a μ-preopen se
Exactly Solvable Hydrogen-like Potentials and Factorization Method
A set of factorization energies is introduced, giving rise to a
generalization of the Schr\"{o}dinger (or Infeld and Hull) factorization for
the radial hydrogen-like Hamiltonian. An algebraic intertwining technique
involving such factorization energies leads to derive -parametric families
of potentials in general almost-isospectral to the hydrogen-like radial
Hamiltonians. The construction of SUSY partner Hamiltonians with ground state
energies greater than the corresponding ground state energy of the initial
Hamiltonian is also explicitly performed.Comment: LaTex file, 21 pages, 2 PostScript figures and some references added.
To be published in J. Phys. A: Math. Gen. (1998
On property (Saw) and others spectral properties type Weyl-Browder theorems
An operator T acting on a Banach space X satisfies the property (aw) if σ(T) \ σw(T) = Ea(T), where σw(T) is the Weyl spectrum of T and Eo a(T) is the set of all eigenvalues of T of finite multiplicity that are isolated in the approximate point spectrum of T. In this paper we introduce and study two new spectral properties, namely (Saw) and (Sab), in connection with Weyl-Browder type theorems. Among other results, we prove that T satisfies property (Saw) if and only if T satisfies property (aw) and σSBF-+(T) = σw(T), where σSBF-+ (T) is the upper semi B-Weyl spectrum of T
MACROALGAS MARINAS DE LA BAHÍA DE SAN QUINTÍN, BAJA CALIFORNIA, MÉXICO
In order to know the composition anddistribution of macroalgae species in thelagoon complex of San Quintin Bay, BajaCalifornia, nine sampled were realized inthree sites during 1988, 1989, 1990, 1995 and1996; also a bibliographyc revision on themarine benthic algae cited from the studyarea. A total of 37 genera with 46 species ofmarine macroalgae were determined, ofwhich 22 are Rhodophyta, (47.82 %), 12Phaeophyta (26.08 %) and 12 Chlorophyta(26.08 %). The floristic list includes data onthe presence and distribution of speciesfound, reproductive stage, substrate and epiphytism. The families with bestrepresentation with regard to richnessand occurrence are: Corallinaceae,Ceramiaceae, Rhodomelaceae (Rhodophyta); Ectocarpaceae, Scytosiphonaceae(Phaeophyta) and Ulvaceae (Chlorophyta).18 (39.13 %) represent new records from thestudy area. Ulva expansa Linnaeus isreported for the first time for the occidentalcoast of Baja California. The floristc list andthe bibliographyc information wereactualized; the dates show that the numberod species of marine algae from San QuintinBay is composed for 59 species.Con la finalidad de determinar la distribucióny composición de las especies demacroalgas presentes en el complejolagunar de la bahía de San Quintín, BajaCalifornia, se realizaron nueve muestreos entres sitios, durante 1988, 1989, 1990, 1995 y1996; así como una revisión bibliográficade algas marinas citadas para el área deestudio. Los resultados obtenidos delmaterial recolectado indican la presencia de37 géneros con 46 especies, de las cuales22 son Rhodophyta (47.82 %), 12Phaeophyta (26.08 %) y 12 Chlorophyta(26.08 %). En la lista florística se incluyendatos sobre la presencia y distribuciónde las especies en el área de estudio,su estado reproductivo, sustrato yepifitismo. En términos de diversidadde especies, las familias mejorrepresentadas corresponden a Corallinaceae, Ceramiaceae, Rhodomelaceae(Rhodophyta), Ectocarpaceae, Scytosiphonaceae (Phaeophyta) y Ulvaceae(Chlorophyta). Del total de algasidentificadas, 18 (39.13 %) representannuevos registros para el área de estudio. Se cita por primera vez a Ulva expandaLinnaeus para la costa occidental de BajaCalifornia. Al depurar y actualizar lainformación bibliográfica desde el punto devista florístico y nomenclatural, se encontróque la flora marina conocida hasta hoy parala bahía de San Quintín es de 59 especies
Laminosioptes cysticola and Gallibacterium anatis infections in a lymphoma diseased chicken hen with a cystic right oviduct
A domestic hen showing infraorbital swelling was presented for a routine classroom demonstration of avian diagnostics. At necropsy, tiny whitish caseo-calcareous nodules were found in the subcutaneous tissues of the carcass, produced by the subcutaneous fowl mite, Laminosioptes cysticola. Gallibacterium anatis biovar haemolytica was isolated from the infraorbital sinus, it containing a caseous exudate. During necropsy, a conspicuous cyst was found in the abdominal cavity. Microscopic examination of the internal lining of the cyst revealed a single cuboidal to columnar, ciliated epithelium, leading to a diagnosis of oviductal cyst. Also, the microscopic examination of the heart, lung, liver and kidney reveal a multifocal infiltration of lymphoma cells. It appears the first case of simultaneous presentation of these conditions from a single chicken
Distorted Heisenberg Algebra and Coherent States for Isospectral Oscillator Hamiltonians
The dynamical algebra associated to a family of isospectral oscillator
Hamiltonians is studied through the analysis of its representation in the basis
of energy eigenstates. It is shown that this representation becomes similar to
that of the standard Heisenberg algebra, and it is dependent of a parameter
. We name it {\it distorted Heisenberg algebra}, where is the
distortion parameter. The corresponding coherent states for an arbitrary
are derived, and some particular examples are discussed in full detail. A
prescription to produce the squeezing, by adequately selecting the initial
state of the system, is given.Comment: 21 pages, Latex, 3 figures available as hard copies upon request from
the first Autho
Calculation of Band Edge Eigenfunctions and Eigenvalues of Periodic Potentials through the Quantum Hamilton - Jacobi Formalism
We obtain the band edge eigenfunctions and the eigenvalues of solvable
periodic potentials using the quantum Hamilton - Jacobi formalism. The
potentials studied here are the Lam{\'e} and the associated Lam{\'e} which
belong to the class of elliptic potentials. The formalism requires an
assumption about the singularity structure of the quantum momentum function
, which satisfies the Riccati type quantum Hamilton - Jacobi equation, in the complex plane. Essential
use is made of suitable conformal transformations, which leads to the
eigenvalues and the eigenfunctions corresponding to the band edges in a simple
and straightforward manner. Our study reveals interesting features about the
singularity structure of , responsible in yielding the band edge
eigenfunctions and eigenvalues.Comment: 21 pages, 5 table
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