994 resultados para Kotzebue Sound region
Resumo:
Con el objetivo de conocer la presencia de agentes Etiológicos causantes de homoparásitosis en equinos se realizó un estudio en la faja del Pacifico de Nicaragua durante los meses de Abril a Noviembre del 2006, en los Departamentos de Carazo, Chinandega, Granada, León, Managua, Masaya y Rivas. Esta zona geográfica del país presenta una temperatura media anual en el rango de 30ºC a 32ºC y una humedad relativa de 76% ± 78 5%; precipitación pluvial media anual en el rango de 1483.9 a 1970.0 mm; la altitud osciló entre 82.97 msnm a 580.13 msnm. Se realizo un muestreo de 150 equinos mayores de dos años, correspondiente al 1.30 % de la población muestradas, en los cuales se tomo 3cc de sangre de la vena yugular, mediante una punción, a las muestras de sangre se les realizo dos frotis sanguíneos, y se obtuvo el hematocrito de la misma , tiñéndose los frotis sanguíneos por el método de Giemsa, posteriormente se observaron los frotis sanguíneos por cada equino muestrado, se utilizo microscopia óptica de inmersión para identificar lo hemoparásitos haciendo uso de los parámetros morfológicos de sus clasificación taxonómica. Se encontraron 58 equinos positivos de Babesia ssp correspondiente al 38.66 % de los 150 equinos muestrados y 92 casos de equinos negativos de Babesia ssp correspondiente al 61.33 % de los 150 equinos muestrados. Además se encontró prevalencia de Babesia de 5.92% en toda la faja del pacifico, encontrando para cada uno de los Departamentos muestrados son: a Managua con un 7.14 %, Masaya 6.43%, Granada 5.71%, Rivas 7.14%, Carazo 3,57%, León 3,57%, Chinandega 7,86% de Babesia ssp.
Resumo:
El presente trabajo se realizó con el fin de contribuir al conocimiento dando a conocer la Caracterización del comportamiento de la estomatitis Vesicular en animales domésticos de pezuña hendida en la región VI (Jinotega y Matagalpa) en el periodo 2008, debido a su gran poder de difusión considerando que en Nicaragua no existe un programa de erradicación o control de la estomatitis vesicular, aunque los humanos también pueden contraer estomatitis vesicular. Se hizo necesario realizar un monitoreo de la enfermedad en esta región, determinar el tipo de cepa que es mas prevalente en la especie de pezuña hendida y el lugar anatómico que más afecta , se tomaron muestras en conjunto con técnicos del MAGFOR y fueron enviadas al Laboratorio de Diagnóstico de Enfermedades Vesiculares (LADIVES) ,localizado en Panamá, se llevó a cabo un análisis estadístico descriptivo, para este análisis se utilizó la información que se colectó en los casos atendidos entre el mes de Julio a Diciembre 2008 y la información retrospectiva de Enero a Junio, con apoyo de la base de datos de Enfermedades Vesiculares que lleva la oficina del Convenio Bilateral Antiaftosa (CAB) del MAGFOR Se elaboraron distribuciones de frecuencia, para las variables; diagnóstico, prevalencia, especie animal y región anatómica, lo que nos accedió informarnos sobre los valores concretos que adoptaron las variables a analizar y sobre el número(o porcentaje) de veces que se repite cada uno de esos valores y nos permitió construir los diagramas con los resultados, concluyendo que de un total de 132 muestras enviadas al laboratorio 82 resultaron positivas a Estomatitis Vesicular, 44 de ellas resultaron al serotipo New Jersey en la zona de Matagalpa y 33 en Jinotega, 5 resultaron positivas al serotipo Indian a en Matagalpa y en la región de Jinotega no se presentó ninguna positiva a este serotipo, la especie más afectada fue el bovino, de las 132 muestras enviadas 129 fueron tomadas en esta especie, siendo las pezuñas el lugar anatómico de mayor predilección para el virus, del total de muestras 91 se tomaran esta región, manifestándose con mayor frecuencia en épocas de lluvia sobre todo en los meses de mayo a octubre.
Resumo:
We propose a single optical photon source for quantum cryptography based on the acousto-electric effect. Surface acoustic waves (SAWs) propagating through a quasi-one-dimensional channel have been shown to produce packets of electrons which reside in the SAW minima and travel at the velocity of sound. In our scheme these electron packets are injected into a p-type region, resulting in photon emission. Since the number of electrons in each packet can be controlled down to a single electron, a stream of single (or N) photon states, with a creation time strongly correlated with the driving acoustic field, should be generated.
Resumo:
The generation of sound by turbulent boundary-layer flow at low Mach number over a rough wall is investigated by applying a theoretical model that describes the scattering of the turbulence near field into sound by roughness elements. Attention is focused on the numerical method to approximately quantify the absolute level of far-field radiated roughness noise. Models for the source statistics are obtained by scaling smooth-wall data by the increased skin friction velocity and boundary-layer thickness for a rough surface. Numerical integration is performed to determine the roughness noise, and it reproduces the spectral characteristics of the available empirical formula and experimental data. Experiments are conducted to measure the radiated sound from two rough plates in an open jet The measured noise spectra of the rough plates are above that of a smooth plate in 1-2.5 kHz frequency and exhibit reasonable agreement with the predicted level. Estimates of the roughness noise for a Boeing 757 sized aircraft wing with idealized levels of surface roughness show that hi the high-frequency region the sound radiated from surface roughness may exceed that from the trailing edge, and higher overall sound pressure levels are observed for the roughness noise. The trailing edge noise is also enhanced by surface roughness somewhat A parametric study indicates that roughness height and roughness density significantly affect the roughness noise with roughness height having the dominant effect The roughness noise directivity varies with different levels of surface roughness. Copyright © 2007 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Resumo:
The generation of sound by turbulent boundary layer flow at low Mach number over a rough wall is investigated by applying the theoretical model which describes the scattering of the turbulence near field into sound by roughness elements. Attention is focused on the numerical method to approximately quantify the absolute level of the roughness noise radiated to far field. Empirical models for the source statistics are obtained by scaling smooth-wall data through increased skin friction velocity and boundary layer thickness for the rough surface. Numerical integration is performed to determine the roughness noise, and it reproduces the spectral characteristics of the available empirical formula and experimental data. Experiments are conducted to measure the radiated sound from two rough plates in an open jet by four 1/2'' free-field condenser microphones. The measured noise spectra of the rough plates are above that of a smooth plate in 1-2.5 kHz frequency and exhibits encouraging agreement with the predicted spectra. Also, a phased microphone array is utilized to localize the sound source, and it confirms that the rough plates generate higher source strengthes in this frequency range. A parametric study illustrates that the roughness height and roughness density significantly affect the far-field radiated roughness noise with the roughness height having the dominant effect. The estimates of the roughness noise for a Boeing 757 sized aircraft wing show that in high frequency region the sound radiated from surface roughness may exceed that from the trailing edge, and higher overall sound pressure levels for the roughness noise are also observed.
Resumo:
In this paper we consider the propagation of acoustic waves along a curved hollow or annular duct with lined walls. The curvature of the duct centreline and the wall radii vary slowly along the duct, allowing application of an asymptotic multiple scales analysis. This generalises Rienstra's analysis of a straight duct of varying cross-sectional radius. The result of the analysis is that the modal wavenumbers and mode shapes are determined locally as modes of a torus with the same local curvature, while the amplitude of the modes evolves as the mode propagates along the duct. The duct modes are found numerically at each axial location using a pseudo-spectral method. Unlike the case of a straight duct, there is a fundamental asymmetry between upstream and downstream propagating modes, with some mode shapes tending to be concentrated on either the inside or outside of the bend depending on the direction of propagation. The interaction between the presence of wall lining and curvature is investigated in particular; for instance, in a representative case it is found that the curvature causes the first few acoustic modes to be more heavily damped by the duct boundary than would be expected for a straight duct. Analytical progress can be made in the limit of very high mode order, in which case well-known 'whispering gallery' modes, localised close to the wall, can be identified.
Resumo:
We present solutions to scattering problems for unsteady disturbances to a mean swirling flow in an annular duct with a rigid 'splitter'. This situation has application to rotor-stator interaction noise in aeroengines, where the flow downstream of the fan is swirling and bifurcates into the by-pass duct and the engine core. We also consider the trailing edge extension of this problem. Inviscid mean flow in a cylindrical annulus is considered, with both axial and swirling (azimuthal) velocity components. The presence of vorticity in the mean flow couples the acoustic and vorticity modes of irrotational flow. Instead we have one combined spectrum of acoustic-vorticity waves in which the 'sonic' and 'nearly-convected' modes are fully coupled. In addition to the aeroacoustics application the results offer insight into the behaviour of these acoustic-vorticity waves, and the precise nature of the coupling between the two types of mode. Two regimes are discussed in which progress has been made, one for a specialised mean flow, uniform axial flow and rigid body swirl, and a second regime in which the frequency is assumed large, valid for any axisymmetric mean flow. The Wiener-Hopf technique is used to solve the scattering problems mathematically, and we present numerical evaluations of these solutions. Several new effects are seen to arise due to the mean vorticity, in particular the generation of sound at a trailing edge due to the scattering of a nearly convected disturbance, in contrast to the way a convected gust silently passes a trailing edge in uniform mean flow.
Resumo:
Durante el período de los meses de junio 1989 a febrero 1990, se estudió la fluctuación poblacional de la broca del fruto del cafeto Hypothenemus hampei Ferr. en alturas de 950,1000 y 11SO m.s.n.m en la Región VI de Nicaragua. La temperatura en las localidades del estudio oscila entre 18 y 212 C. Las mayores precipitaciones se registran de junio a noviembre y la menor de diciembre a febrero. Los niveles máximos de infestación de broca oscilaron entre 0.5 y 1.55% de frutos brocados encontrandose mayores niveles en las menores alturas donde se observa que el incremento de la población ocurre entre los 107 y 246 días después de la floración principal (ddfp). En las alturas superiores a 1000 m.s.n.m las infestaciones comienzan incrementarse en fechas tardías (141 ddfp). Sin embargo, dichos niveles decrecen al momento de la cosecha. El desarrollo de los diferentes estadíos de H. hampei resultó diferentes en las localidades estudiadas. La producción de huevos se inicia más temprano en las zonas de menor altitude (78 ddfp) en comparación con zonas de mayor altitud (141 ddfp). Las poblaciones de huevos, larvas y pupas aumentan posteriormente con al número de adultos, alcanzando los máximos valores durante la maduración del fruto y disminuyendo al momento final de la cosecha. H. hampei se reproduce en frutos semiconsistentes, consistentes y maduros, sin embargo, se puede encontrar adultos de broca en los canales de penetración en los frutos en estado lechoso.
Resumo:
El presente trabajo de investigación se llevó a cabo en la IV región del pais con el fin de obtener una relación entre los diferentes grados de abastecimiento hídrico y los rendimientos del cultivo del maiz, variedad NB-6, para asi poder dar un mejor uso de los recursos hidricos (en nuestro caso las precipitaciones) mediante la determinación de fechas de siembra con el menor riesgo posible de pérdidas económicas. Nos encontramos con la limitante de trabajar con un número no muy grande de muestras debido a perdida de información (registros incompletos) y además de trabajar con solamente un ciclo de producción disminuyendo esto la variabilidad de los datos. Se logró validar efectivamente un modelo de balance hidríco para las condiciones especificas del año en estudio < 1989) y se encontró una relación clara, aunque no rígida, entre el indice de satisfacción hidrica del cultivo y los rendimientos obtenidos en ese año. Sin embargo, se recomienda utilizar modelos mas precisos para este tipo de investigación y repetirlo sobre una serie mayor de años. Por ahora, solo contamos con esta relación obtenida y de utilización reservada.
Resumo:
To describe the various complex mechanisms of the dissipative dynamical system between waves, currents, and bottoms in the nearshore region that induce typically the wave motion on large-scale variation of ambient currents, a generalized wave action equation for the dissipative dynamical system in the nearshore region is developed by using the mean-flow equations based on the Navier-Stokes equations of viscous fluid, thus raising two new concepts: the vertical velocity wave action and the dissipative wave action, extending the classical concept, wave action, from the ideal averaged flow conservative system into the real averaged flow dissipative system (that is, the generalized conservative system). It will have more applications.
Resumo:
The evidence from Erimi-Laonin tou Porakou within the Kouris valley settlement system can offer further new data to outline a picture of the development trends from MBA to LBA I periods in the Kourion region. As to this area, such a “transitional” phase could be particularly relevant to better understand the development process of the mature LBA II–III urban centers (in Alassa as well as the most recent discovered in Erimi-Pitharka). In 2008–2009 a focus investigation (an intensive survey, geoperspections and excavations) within the Kouris Valley Project has been addressed to the site of Erimi-Laonin tou Porakou, which lies on one of the highest hilltops facing southward the Kouris dam. The excavations evidenced a double circuit wall which surrounds the top mound and the lower terrace. The top mound (Area A) has been widely occupied by a complex workshop, directly linked with a storage area. The natural limestone bedrock has been worked out to arrange a system of carved deep basins connected each other by a series of flow channels. Southward from the workshop, a large storage area has been cleared, with a relevant assemblage of big pithoi and storage devices. The first lower terrace area (Area B) has been possibly occupied by a domestic quarter; a cemetery area (Area E) has been also evidenced outside the external circuit wall, where a series of five rock-cut tombs (Tombs 228– 232) with single chamber and small incoming dromoi has been excavated.