1,488 research outputs found
ESTIMACIÓN DEL HIDROGRAMA DE CRECIENTES CON MODELACIÓN DETERMINÍSTICA Y PRECIPITACIÓN DERIVADA DE RADAR
En este estudio se destaca la importancia del uso de precipi- tación estimada por radar, en la modelación hidrológica de caudales máximos en cuencas con pluviometría deficiente. El modelado hidrológico con precipitación estimada por radar toma en consideración, detalladamente, la variabili- dad espacial y temporal de la precipitación. El objetivo del presente estudio fue evaluar la simulación hidrológica de la cuenca del río Escondido en la estación hidrométrica 24290 (en Villa de Fuentes, Coahuila, México). El modelo hidroló- gico HEC-HMS fue utilizado para simular los caudales pico con datos de precipitación estimada por radar. La cuenca se ubica en una zona semidesértica con la característica de escurrimientos efímeros y eventos extraordinarios poco fre- cuentes registrados durante el periodo de medición (1932 a la fecha). Los eventos analizados fueron: 3 de junio del 2003, 29 de septiembre del 2006 y 5 de abril del 2004, que han sido los únicos importantes del periodo de disponibili- dad de datos de radar. Los datos de precipitación etapa IV del radar NEXRAD, ubicado en la base militar Launghlin, Texas, fueron adaptados al caso de estudio. Para evaluar los resultados se utilizaron los criterios gráficos y numéricos: comparación de hidrogramas de forma visual y el coeficien- te de Eficiencia de Nash-Sutcliffe (E). Los resultados obteni- dos fueron satisfactorios debido a valores de los coeficientes Eficiencia de Nash-Sutcliffe (E) iguales con 0.96 en la cali- bración y 0.91 en la validación del modelo
Foreign invasions and the formation of the State in southern Mozambique
Este artigo se propõe indagar o processo de construção nacional, e o de modernização implícito nele, referidas ao sul de Moçambique. Parte do questionamento da tendência de uma certa historiografia europeia de querer ordenar o mundo africano à própria imagem, exemplificada na construção de uma identidade histórica imprecisa – “Tsonga” – sob um ideário nacional. Em seguida pretende-se estabelecer uma relação entre identidade étnica e condição social, sobretudo pensada a partir da primeira e parte da segunda metade do século XIX, levantando algumas hipóteses. Em primeiro lugar, que historicamente essa região caracterizou-se pela coexistência imbricada de duas formas econômicas: o comércio e a circulação voltada para o exterior, e as formas domésticas de reprodução e redistribuição. Em segundo lugar seria possível sugerir que os processos de diferenciação e estratificação social, derivados destas relações de produção e reprodução, sejam anteriores à ocupação efetiva dos portugueses (1895) e não a partir dela. Em terceiro lugar, a partir do processo que aqui se denomina de “burocratização dos tributos” iniciado após a ocupação efetiva por parte da administração colonial portuguesa, estes processos de diferenciação e estratificação social se tornariam processos de exclusão social e políticaWith a focus on southern Mozambique, this article proposes to examine the process of nation-building and the modernization implicit within it. It begins with questioning the tendency of a certain European historiography to order the African world in its own image, exemplified by the construction of an inaccurate historical identity – “Tsonga” – under a national ideology. Next, the article attempts to establish a relationship between ethnic identity and social conditions, especially considering the first and part of the second half of the nineteenth century, raising some hypotheses. In the first place, this region has been historically characterized by the overlapping coexistence of two economic forms: the foreign-oriented trade and circulation, and domestic forms of reproduction and redistribution. Secondly, it would be possible to suggest that the processes of differentiation and social stratification, derived from this coexistence, predate the occupation of the Portuguese (1895), and therefore were not instigated by it. Third, from the process that we will label “bureaucratization of taxes”, initiated after the effective occupation by the Portuguese colonial administration, these processes of differentiation and social stratification would become processes of social and political exclusionCet article examine le processus de construction nationale et de modernisation implicite qu’il contient, en relation au Sud du Mozambique. Il part de la tendance d’une certaine historiographie européenne qui voulut façonner le monde africain à son image, concré- tisée ici par la construction d’une identité historique imprécise – “Tsonga” – sous la forme d’un idéal national. Il prétend ensuite établir la relation entre identité ethnique et condition sociale, surtout dans la première et une partie de la seconde moitié du xixe siècle, émettant diverses hypothèses. La première est que, historiquement, cette région a été caractérisée par la coexistence imbriquée de deux réalités économiques: le commerce et la circulation tournées vers l’extérieur, et les formes domestiques de reproduction et redistribution. La seconde, relative aux processus de différenciation et de stratification sociales issus de ces relations de production et de reproduction, est que ces derniers furent antérieurs à l’occupation effective des Portugais (1895) et n’ont pas été provoqués par elle. La troisième, à partir de ce que l’on appellera ici la “bureaucratisation fiscale” de la part de l’administration coloniale portugaise, après l’occupation effective, est que ces processus de différenciation et stratification sociales sont devenus des processus d’exclusion sociale et politiqu
Formas de resistências cotidianas durante o colonialismo tardio no sul de Moçambique.
Since the so-called “effective occupation” made by the Portuguese (1895), Mozambique has experienced profound transformations. These transformations were marked by the introduction of different development projects, all characterized by a confrontation between forms and perceptions of the political,social and economic etc. Locating our reflection in the south of the country and in dialogue with history and anthropology – complementary areas for African studies – we will inquire the relationship between economic modernization and political modernity from a re-reading, on the one hand, of the processes of regimentation of native labor by the colonial enterprise and, on the other hand, the dynamics developed by the populations of the region in response to these policies, many of them pointed out here as forms of everyday resistance.Methodologically combining the colonial situation and the indiciary paradigm, we will revisit sources collected in previous works by authors from the two areas mentioned above, and then introduce the concepts of forced mobility, state margins, coloniality and power repertoires, searching a reinterpretation of the relationship between colonial enterprise and autonomous practices.Desde sua independência Moçambique experimentou transformações econômicas, políticas e sociais profundas. Estas transformações estiveram marcadas pela introdução de diferentes projetos de desenvolvimento que apontavam transformar um mundo rotulado de tradicional para um moderno. Localizando nossa reflexão no sul do país, tentaremos questionar os processos de arregimentação da mão de obra nativa por parte da empresa colonial e as dinâmicas que esta população desenvolveu como respostas a estas políticas, privilegiando uma abordagem que discuta a relação entre modernização econômica e modernidade política. Combinando o conceito de mobilidade forçada e margens do estado, assim como os conceitos de colonialidade e repertórios de poder, tentamos fazer uma releitura da relação entre empresa colonial e práticas autonômicas. Pretende-se assim refletir o caráter compulsório do uso da força de trabalho desde uma perspectiva que evidencie o ethos colonial dos europeus e confrontá-lo às diversificadas respostas dos habitantes da região, e em especial entender como estes processos vão mobilizar racionalidades e subjetividades diversas as quais parecem permear uma serie de práticas no período pós-colonial
Entendendo a(s) Historia(s) da Africa. Uma primeira aproximacao a um continente aparentemente conhecido.
Apreseentação do dossiê sobre África organizado pelo prof. Dr. Hector Guerr
La eutanasia en España. Proyecto de ley
A pesar de que se ha avanzado en lo referente a la calidad de vida, no es suficiente, ya
que a medida que pasa el tiempo se amplía el número de personas que sufren una
enfermedad incurable. La cuestión a debatir es si la libre decisión de poner término a la
vida, debe o no encontrar un apoyo en la sociedad, y más concretamente, en el
ordenamiento jurídico. Es un tema complejo, de ahí que tenga especial importancia la
eutanasia, para evitar sufrimiento y dolor en el ser humano, que está atravesando dicha
enfermedad. Se debe destacar el artículo 143 Código Penal, se deduce la dificultad de
distinguir en la práctica entre eutanasia activa y pasiva.
Destaca el testamento vital o declaración de instrucciones previas para los casos
legalmente previstos de eutanasia pasiva.
En España se pretende aprobar la Ley de la eutanasia, tiene como objetivo "dar una
respuesta jurídica, sistemática, equilibrada y garantista a una demanda social", tal y como
se desprende de la exposición de motivos de la Proposición de Ley. Como ya sabemos,
vida y calidad de vida, no son sinónimos.Although progress has been made in terms of quality of life, it is not enough, as time goes
on the number of people suffering from an incurable disease. The question to be discussed
is whether or not the free decision to end life must find support in society, and more
specifically, in the legal order. It is a complex issue, hence euthanasia is of particular
importance, to avoid suffering and pain in the human being, who is going through that
disease. It should be noted article 143 Penal Code, it follows the difficulty of
distinguishing in practice between active and passive euthanasia.
The living will or declaration of prior instructions for legally foreseen cases of passive
euthanasia stands out.
In Spain it is intended to adopt the Law on euthanasia, with the aim of "giving a legal,
systematic, balanced and guaranteeing response to a social demand", as is apparent from
the explanatory memorandum of the Proposition of Law. As we already know, life and
quality of life are not synonymous
Has the chemical contribution a secondary role in SERS?
It is an established understanding that the electromagnetic contribution (the
plasmon-mediated enhancement of the laser and scattered local electromagnetic
fields) is the main actor in Surface Enhanced Raman Scattering (SERS), with the
so-called chemical (molecule-related) contribution assuming only, if any, a
supporting role. The conclusion of our comprehensive resonant study of a broad
range of nanosphere lithography based metallic substrates, with covalently
attached 4-mercaptobenzoic acid monolayers used as probe (molecules
non-resonant in solution), is that this accepted understanding needs to be
revised. We present a detailed resonant SERS study of Metal-film over
nanosphere (MFON) substrates done both by scanning the laser wavelength, and by
tuning the plasmon response through the nanosphere diameter. Far and local
field properties are characterized through measures of optical reflectivity and
SERS efficiency, respectively, and are supported by numerical simulations. We
demonstrate that the SERS efficiency depends indeed on the electromagnetic
mechanism, determined by the plasmonic response of the system, but we observe
that it is also strongly defined by a chemical resonant contribution related to
a metal-to-ligand electronic transition of the covalently bound probe molecule.
Optimum amplification occurs when the plasmon modes intersect with the
ligand-to-metal chemical resonance, contributing synergically both mechanisms
together. The same general trend is observed for other nanosphere lithography
based substrates, including sphere-segment void cavities and hexagonally
ordered triangular nanoparticles, using both Ag or Au as the plasmonic metal,
and also with a commercial substrate (Klarite). We conclude that a deep
understanding of both the electromagnetic and chemical mechanisms is necessary
to fully exploit these substrates for analytical applications
Distributed Parameter Bioprocess Plant Identification and I-Term Control Using Decentralized Fuzzy-Neural Multi-Models
Application of Sustainable Remediation Techniques for Heavy Metal Reduction in Polluted Rivers in Mining Zones: Study Area Ponce Enriquez
Mining activity in Ecuador is primarily artisanal and small-scale. Rivers near the mining county of Camilo Ponce Enriquez have been severely affected by this type of mining. A field study was conducted encompassing 29 sites on the rivers Siete, Fermin, and Pagua during sampling campaigns that took place in both dry (December) and wet seasons (February). Physiochemical parameters and heavy metal concentrations were measured to enable environmental characterization of the rivers. Results revealed that most of the sampled sites had bad water quality and exceeded the environmental limits of heavy metal concentrations set by the Ecuadorian government. A parallel pilot investigation was performed for reducing the heavy metal concentrations in water ecosystems polluted by mining activities using bioremediation techniques. The bioremediation technique applied in the study used bacteria from a wastewater digestor and sugarcane bagasse as a carbon source to support the bacterial community. Sulfide was measured to monitor bacterial activity in experimental bioreactors containing local acid mine drainage (AMD). The results obtained were encouraging, as a significant decrease in heavy metal concentration was observed to nearly the level of Ecuadorian environmental regulations for Al, Cd, Cu, Fe, Pb, and Zn concentrations in freshwater in a set of bioreactors.
Keywords: acid drainage, artisanal mining, bioremediation, heavy metals, pollution.
Resumen
La actividad minera en el Ecuador es principalmente artesanal y de pequeña escala. Los ríos cercanos al área minera de Camilo Ponce Enríquez se han visto severamente afectados por este tipo de minería. Se realizó un estudio de campo en 29 sitios sobre los ríos Siete, Fermín y Pagua durante campañas de muestreo que se realizaron tanto en la época seca (diciembre) como en época húmeda (febrero). Se midieron parámetros fisicoquímicos y concentraciones de metales pesados para permitir la caracterización ambiental de los ríos. Los resultados revelaron que la mayoría de los sitios muestreados tienen agua de mala calidad y excedieron los límites ambientales de concentración de metales pesados establecidos por el gobierno ecuatoriano. También se realizó una investigación piloto paralela destinada a reducir las concentraciones de metales pesados en ecosistemas acuáticos contaminados por actividades mineras utilizando técnicas de biorremediación. La técnica de biorremediación aplicada en el estudio utilizó bacterias de un digestor de aguas residuales y bagazo de caña de azúcar como fuente de carbono para apoyar a la comunidad bacteriana. Se midió el sulfuro para controlar la actividad bacteriana en biorreactores experimentales que contenían drenaje ácido minero (AMD) local. Los resultados obtenidos son alentadores ya que en un conjunto de biorreactores se observó una disminución significativa de las concentraciones de algunos metales pesados alcanzando casi en su mayoría el nivel permisible según las regulaciones ambientales ecuatorianas para las concentraciones de Al, Cd, Cu, Fe, Pb y Zn en agua dulce.
Palabras Clave: drenajes ácidos, minería artesanal, biorremediación, metales pesados, contaminación
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