Study of the surface water circulation in San Blas channel (Argentina) using landsat imagery

Este trabalho analisa a turbidez e a circulação da agua no canal San Blas durante um ciclo de maré teórico através de imagens satelitais. Foram utilizadas 8 imagens Landsat TM e ETM adquiridas em condições de céu claro e ao longo de diferentes momentos da maré. As imagens foram proporcionadas pela Comisión Nacional de Actividades Espaciales (CONAE) y pelo Serviço Geológico dos Estados Unidos (USGS). As correções geométricas e radiométricas foram realizadas nas bandas do espectro visível e do infravermelho próximo, utilizando técnicas padrões de processamento digital. Foi aplicada a correção atmosférica COST (CHAVEZ, 1996). Foi realizada uma classificação ISODATA não supervisionada para identificar diferentes níveis de turbidez al longo do canal e zonas adjacentes. Os resultados sugerem que o transporte de sedimento em suspensão para a boca do canal se da ao longo de ambos flancos, pela ação das correntes de refluxo. Estas correntes geram um delta de refluxo com uma tendência de rotação para a direção sul. As correntes de fluxo provocam turbidez principalmente sobre a costa sul do canal, gerando um delta de fluxo com bancos alargados na direção das correntes de maré. As plumas de turbidez permitiram identificar padrões gerais de circulação da maré.This paper deals with the application of satellite images to study turbidity and water circulation patterns in San Blas channel during a theoretical tidal cycle. Eight Landsat TM and ETM images acquired under clear-sky conditions and representing different tidal stages were selected from a pool of Landsat images provided by the argentinean National Commission of Space Activities (CONAE) and the US Geological Survey. Standard digital image processing techniques were used to perform geometric and radiometric corrections on the visible and near-infrared bands. An image-based atmospheric correction (COST method by CHAVEZ, 1996) was applied. An ISODATA unsupervised classification was performed in order to identify different turbidity levels throughout the channel and adjacent areas. The results suggest that suspended sediment transport towards the channel mouth by ebb currents occurs along both flanks. These currents carry suspended sediment into the open sea, generating an ebb tidal delta which tends to rotate in a clockwise direction. Flood currents trigger turbidity mostly over the southern flank of the channel, generating a flood tidal delta with elongated banks extending in the direction of the tidal currents. From the elongated shape of the turbidity plumes, general tidal circulation patterns were identified

Distribution and morphometry of shallow lakes in a temperate zone (Buenos Aires Province, Argentina)

We have developed a database of water bodies to characterise and assess the distribution and morphometry of Pampean shallow lakes and reservoirs in a temperate zone (Buenos Aires Province, Argentina). In the study area, there are over 2000 shallow lakes with a mean area 2. In the last two cases, geomorphology determines the morphometry and location of these shallow lakes. The development of numerous water bodies with areas 2). En los últimos dos casos, la morfometría y la localización de los lagos fue influenciada por la geomorfología. El desarrollo de numerosos cuerpos de agua cuya área media es menor a 1 km2 causó un incremento en el número de cuerpos de agua durante el año húmedo. El área cubierta por agua y la densidad de los lagos fue más baja en la zona de mesetas (situada al oeste del área de estudio), baja en la zona serrana, moderada en el centro del área de estudio y alta en las planicies del sector este del área de estudio

Procesos ambientales que afectan la bahía San Antonio y su área de adyacencia (Prov. de Rio Negro)

Natural processes together with human activities represent necessary variables for the changes affecting different environments in coastal areas. The aim of this paper is to identify, through the use of geo-technologies, the environmental processes that affect the natural area in the San AntonioBay, which includes the cities of San Antonio Oeste, San Antonio Este and Las Grutas. Satellite images (Spot and Landsat 5 and 7) of different tide states, aerial photographs, topographic and nautical charts were processed. All the information obtained was systematized and integrated in a GIS (Geographic Information System). The morphology of the area under study consists of tidal plains and tidal channels, spits, dunes and cliffs. This ecosystem undergoes natural processes such as: eutrophication in the channel of La Mareain San Antonio Oeste, sedimentation of tidal channels in San Antonio Este and in the Villarino peninsula, accretion in coastal areas and sandbanks displacement. Likewise, the urban growth of San Antonio Oeste directly affects the natural environment of the protected area as well as the industrial activities and urban wastes. Los procesos naturales y las actividades humanas son las variables necesariasen los cambios que afectan a los diferentes ambientes en las zonascosteras. El objetivo de este trabajo es identificar los procesos ambientalesque afectan al área natural de la bahía San Antonio, que incluye a laslocalidades de San Antonio Oeste y San Antonio Este, y Las Grutas medianteel uso de geo-tecnologías. Se procesaron imágenes satelitales (Spot yLandsat 5 y 7) en distintos estados de marea, fotografías aéreas, cartastopográficas y náuticas. Toda la información obtenida fue sistematizada eintegrada en un SIG. La morfología del área de estudio está integrada porplanicies y canales de mareas, cordones, playas, médanos y acantilados.Este ecosistema sufre procesos naturales como son: la eutrofización delcanal de La Marea en San Antonio Oeste, sedimentación de canales de mareaen San Antonio Este y en la península Villarino se observa acreción enla zona costera y desplazamiento de médanos. Asimismo, el crecimientourbano de San Antonio Oeste afecta directamente los ambientes naturalesdel área protegida como así también los usos industriales y las descargasurbanas

Microclima Urbano: variaciones Termo-Higrométricas de Bahía Blanca, Argentina

O objetivo deste estudo foi analisar o comportamento termohigrométrico em diferentes locais da cidade. Para isso, foram projetadas e instaladas dez estações meteorológicas em diferentes bairros da cidade de Bahía Blanca (Argentina) durante 408 dias com frequência de amostragem de 30 minutos. A análise foi realizada em diferentes escalas de tempo: anual, sazonal, mensal, diária, diurna e nocturna. Técnicas estatísticas diferentes foram utilizadas para analisar as informações. Diferentes comportamentos termo-higrométricos definidos pelas diferenças espaciais na rugosidade do espaço e densidade de edifícios em Bahia Blanca foram identificados, permitindo explicar o microclima local da cidad

Tormentas severas: ¿Cuán vulnerables son las costas del sur de la provincia de Buenos Aires (Argentina)?

La zona costera del sur de la provincia de Buenos Aires, Argentina, está caracterizada por la presencia de localidades donde las principales actividades son el turismo de sol y playa. Las tormentas severas con vientos fuertes constituyen los principales eventos climáticos que dañan estas costas. El objetivo de este capítulo es describir la erosión que se produce en las costas del sur de la provincia de Buenos Aires originada por tormentas severas. El número y la intensidad de estas tempestades varía de década en década como consecuencia de la variabilidad climática. Se describen los cambios en los perfiles de playa y la vulnerabilidad de la costa a la erosión en las playas de Pehuen Co, Monte Hermoso y Necochea-Quequén. La pérdida del sedimento y la destrucción de las infraestructuras fueron los mayores impactos encontrados.Fil: Piccolo, Maria Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Merlotto, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Bustos, María Luján. Universidad Nacional del Sur. Departamento de Geografía y Turismo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Huamantinco Cisneros, María Andrea. Universidad Nacional del Sur. Departamento de Geografía y Turismo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: García, Mónica C.. Universidad Nacional de Mar del Plata; Argentin

Dermoscopic evaluation of nodular melanoma

Importance: Nodular melanoma (NM) is a rapidly progressing potentially lethal skin tumor for which early diagnosis is critical

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe