989 resultados para Space distribution
Resumo:
The effect of habitat fragmentation on the structure of orchid bee communities was analyzed by the investigation of the existence of a spatial structure in the richness and abundance of Euglossini species and by determining the relationship between these data and environmental factors. The surveys were carried out in four different forest fragments and one university campus. Richness, abundance, and diversity of species were analyzed in relation to abiotic (size of the area, extent of the perimeter, perimeter/area ratio, and shape index) and biotic characteristics (vegetation index of the fragment and of the matrix of each of the locations studied). We observed a highly significant positive correlation between the diversity index and the vegetation index of the fragment, landscape and shape index. Our analysis demonstrated that the observed variation could be explained mainly by the vegetation index and the size of the fragment. Variations in relative abundance showed a tendency toward an aggregated spatial distribution between the fragments studied, as well as between the sampling stations within the same habitat, demonstrating the existence of a spatial structure on a small scale in the populations of Euglossini. This distribution will determine the composition of species that coexist in the area after fragmentation. These data help in understanding the differences and similarities in the structure of communities of Euglossini resulting from forest fragmentation.
Resumo:
An dem Schwerionenspeicherring TSR (MPI für Kernphysik, Heidelberg) wurde ein 7 Li +-Ionenstrahl geringer Dichte durch RF-Bunchen und Laserkühlung präpariert.Die Phasenraumverteilung in dem Strahl wurde durch Laser- spektroskopie an Ionen im metastabilen Zustand untersucht. Ein umlaufsynchrones, zeitaufgelöstes Meßverfahren für das Fluoreszenzlicht ermöglichte die Bestimmung der räumlichen Struktur mit dieser rein optischen Methode.Durch einen speziellen Präparationsschritt wurden die Ionen im Grundzustand aus dem Speicherring entfernt. Der sonst dominierende Heizeffekt der strahlinternen Streuung war dadurch vernachlässigbar und es konnte eine Temperatur von 160 mK erreicht werden.Der präparierte Ionenstrahl bietet besondere Eigenschaften im Hinblick auf Präzisionsexperimente, bei denen mit möglichst ungestörten Ionen gearbeitet werden soll. Es wird gezeigt, daß die Phasenraumverteilung der Ionen nicht mehr durch Ion-Ion-Wechselwirkungen bestimmt ist und daß der verbleibende Heizmechanismus durch die Streuung am Restgas erklärt werden kann.1993 wurde durch Laserspektroskopie an 7 Li + im TSR die spezielle Relativitätstheorie im Hinblick auf die relativistische Zeitdilatation experimentell getestet. In diesem Zusammenhang wird das zu erwartende Ergebnis eines Experimentes diskutiert, das, basierend auf den in dieser Arbeit vorgestellten Verfahren, einen erneuten Test der relativistischen Zeitdilatation mit verbesserter Genauigkeit durchführen könnte.
Resumo:
This dissertation presents a detailed study in exploring quantum correlations of lights in macroscopic environments. We have explored quantum correlations of single photons, weak coherent states, and polarization-correlated/polarization-entangled photons in macroscopic environments. These included macroscopic mirrors, macroscopic photon number, spatially separated observers, noisy photons source and propagation medium with loss or disturbances. We proposed a measurement scheme for observing quantum correlations and entanglement in the spatial properties of two macroscopic mirrors using single photons spatial compass state. We explored the phase space distribution features of spatial compass states, such as chessboard pattern by using the Wigner function. The displacement and tilt correlations of the two mirrors were manifested through the propensities of the compass states. This technique can be used to extract Einstein-Podolsky-Rosen correlations (EPR) of the two mirrors. We then formulated the discrete-like property of the propensity Pb(m,n), which can be used to explore environmental perturbed quantum jumps of the EPR correlations in phase space. With single photons spatial compass state, the variances in position and momentum are much smaller than standard quantum limit when using a Gaussian TEM00 beam. We observed intrinsic quantum correlations of weak coherent states between two parties through balanced homodyne detection. Our scheme can be used as a supplement to decoy-state BB84 protocol and differential phase-shift QKD protocol. We prepared four types of bipartite correlations ±cos2(θ12) that shared between two parties. We also demonstrated bits correlations between two parties separated by 10 km optical fiber. The bits information will be protected by the large quantum phase fluctuation of weak coherent states, adding another physical layer of security to these protocols for quantum key distribution. Using 10 m of highly nonlinear fiber (HNLF) at 77 K, we observed coincidence to accidental-coincidence ratio of 130±5 for correlated photon-pair and Two-Photon Interference visibility >98% entangled photon-pair. We also verified the non-local behavior of polarization-entangled photon pair by violating Clauser-Horne-Shimony-Holt Bell’s inequality by more than 12 standard deviations. With the HNLF at 300 K (77 K), photon-pair production rate about factor 3(2) higher than a 300 m dispersion-shifted fiber is observed. Then, we studied quantum correlation and interference of photon-pairs; with one photon of the photon-air experiencing multiple scattering in a random medium. We observed that depolarization noise photon in multiple scattering degrading the purity of photon-pair, and the existence of Raman noise photon in a photon-pair source will contribute to the depolarization affect. We found that quantum correlation of polarization-entangled photon-pair is better preserved than polarization-correlated photon-pair as one photon of the photon-pair scattered through a random medium. Our findings showed that high purity polarization-entangled photon-pair is better candidate for long distance quantum key distribution.
Resumo:
We provide the circumstances and details of the fireball observation, search expeditions, recovery, strewn field, and physical characteristics of the Kosice meteorite that fell in Slovakia on February 28, 2010. The meteorite was only the 15th case of an observed bolide with a recovered mass and subsequent orbit determination. Despite multiple eyewitness reports of the bolide, only three videos from security cameras in Hungary were used for the strewn field determination and orbit computation. Multiple expeditions of professionals and individual searchers found 218 fragments with total weight of 11.3 kg. The strewn field with the size of 593 km is characterized with respect to the space distribution of the fragments, their mass and size-frequency distribution. This work describes a catalog of 78 fragments, mass, size, volume, fusion crust, names of discoverers, geographic location, and time of discovery, which represents the most complex study of a fresh meteorite fall. From the analytical results, we classified the Kosice meteorite as an ordinary H5 chondrite.
Resumo:
En parcelas con 7 años de siembra directa continua se realizó una labor de escarificado. A los 40 días se abrieron trincheras y sobre una grilla cuadriculada se determinó la penetrometría de pared y la humedad en los perfiles de suelo. Para procesar los histogramas obtenidos en la integración de los relevamientos de resistencia a la penetración en escarificado (E) y no escarificado (NE) se utilizó el módulo fuzzy (tratamiento de imágenes de un sistema de información geográfica). Se determinaron 7 clases de compactación en cada situación, diferenciadas por promedios y rangos. La trinchera con los valores promedios fuzzy de penetrometría en E presentó 25.71 % menos de las clases consideradas más compactadas, siendo significativo el efecto de la labor en el espesor 5-25 cm. No hubo diferencias en humedad entre ambas situaciones, a excepción del estrato 30-35 cm donde -en E- fue mayor. La labor de escarificado produjo modificaciones favorables en los distintos estados de compactación de suelo, principalmente en los espesores intermedios. A través del tratamiento de lógica difusa se determinaron diferentes clases de compactación y su distribución espacial.
Resumo:
The idea of Territorial Intelligence emphasizes the participation of different types from actors in the decisions that concern to the local territory. Between the communitarian actors, the ocal organizations are fundamental because they have an existential knowledge of the geographic space who share the neighbors. That knowledge, is focused generally in the deficiencies of the district or of the district and it is constituted in its reason of being, like average for the defense as opposed to the authority of the local government. This so shared in common function is left lamentably to a quite traditional relation like intermediary between municipality and community annotated. A special case constitutes the cooperative calls of rural services or vicinal organizations that are in charge to administer the service of potable water, those that are generally led by people greater or small proprietors of traditional agriculture. A strong territorial identity can be observed that, as opposed to the transformations and modernization of the field, subsists exactly by that feeling of root. In the province of Mendoza, the importance of the ocal organizations was increased during the decade of the' 90 with the decentralization processes, to canalize house policies, some public works and services in the districts. From a perspective of associated management, projects of economic, cultural, environmental development would have to revitalize their function like organizations able to also agglutinate not only demands but that they promote to the local territory from other dimensions. With these motivations and the purpose of proposing strategies to induce practices of ocal work with territorial intelligence, a set of reflections that allow to compare the space distribution and the characteristics of these organizations between 90 years' and the present time, in some departments of the province of Mendoza appears. The most important result is expressed in a tipología of ocal unions, with a cartography that ties feasible territory and social actors to collaborate to generate transformations social, specially in rural areas
Resumo:
The mean residence time of 234Th associated with suspended matter in the Kara Sea was calculated from distributions of dissolved and suspended 234Th. Integral particulate fluxes at different levels were estimated for two stations. The flux increases only in the pycnocline; below it changes insignificantly. Two maxima of differential fluxes are noted in vertical profiles: in the surface layer where primary production is maximal, and in the interface layer where zooplankton realizing active transport of suspended matter is usually concentrated. Differential fluxes were determined at 10 stations; their space distribution is controlled by primary production, which depends usually on turbidity of river water in estuaries.
Resumo:
The idea of Territorial Intelligence emphasizes the participation of different types from actors in the decisions that concern to the local territory. Between the communitarian actors, the ocal organizations are fundamental because they have an existential knowledge of the geographic space who share the neighbors. That knowledge, is focused generally in the deficiencies of the district or of the district and it is constituted in its reason of being, like average for the defense as opposed to the authority of the local government. This so shared in common function is left lamentably to a quite traditional relation like intermediary between municipality and community annotated. A special case constitutes the cooperative calls of rural services or vicinal organizations that are in charge to administer the service of potable water, those that are generally led by people greater or small proprietors of traditional agriculture. A strong territorial identity can be observed that, as opposed to the transformations and modernization of the field, subsists exactly by that feeling of root. In the province of Mendoza, the importance of the ocal organizations was increased during the decade of the' 90 with the decentralization processes, to canalize house policies, some public works and services in the districts. From a perspective of associated management, projects of economic, cultural, environmental development would have to revitalize their function like organizations able to also agglutinate not only demands but that they promote to the local territory from other dimensions. With these motivations and the purpose of proposing strategies to induce practices of ocal work with territorial intelligence, a set of reflections that allow to compare the space distribution and the characteristics of these organizations between 90 years' and the present time, in some departments of the province of Mendoza appears. The most important result is expressed in a tipología of ocal unions, with a cartography that ties feasible territory and social actors to collaborate to generate transformations social, specially in rural areas
Resumo:
The idea of Territorial Intelligence emphasizes the participation of different types from actors in the decisions that concern to the local territory. Between the communitarian actors, the ocal organizations are fundamental because they have an existential knowledge of the geographic space who share the neighbors. That knowledge, is focused generally in the deficiencies of the district or of the district and it is constituted in its reason of being, like average for the defense as opposed to the authority of the local government. This so shared in common function is left lamentably to a quite traditional relation like intermediary between municipality and community annotated. A special case constitutes the cooperative calls of rural services or vicinal organizations that are in charge to administer the service of potable water, those that are generally led by people greater or small proprietors of traditional agriculture. A strong territorial identity can be observed that, as opposed to the transformations and modernization of the field, subsists exactly by that feeling of root. In the province of Mendoza, the importance of the ocal organizations was increased during the decade of the' 90 with the decentralization processes, to canalize house policies, some public works and services in the districts. From a perspective of associated management, projects of economic, cultural, environmental development would have to revitalize their function like organizations able to also agglutinate not only demands but that they promote to the local territory from other dimensions. With these motivations and the purpose of proposing strategies to induce practices of ocal work with territorial intelligence, a set of reflections that allow to compare the space distribution and the characteristics of these organizations between 90 years' and the present time, in some departments of the province of Mendoza appears. The most important result is expressed in a tipología of ocal unions, with a cartography that ties feasible territory and social actors to collaborate to generate transformations social, specially in rural areas
Resumo:
The monograph highlights extensive materials collected during expeditions of P.P. Shirshov Institute of Oceanology. We consider facial conditions of nodule formation, regularities of their distribution, stratigraphic position, petrography, mineral composition, textures, geochemistry of nodules and hosting sediments. Origin of iron-manganese nodules in the Pacific Ocean is considered as well.