2,448 research outputs found

    Tsunami excitation by inland/coastal earthquakes: the Green function approach

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    International audienceIn the framework of the linear theory, the representation theorem is derived for an incompressible liquid layer with a boundary of arbitrary shape and in a homogeneous gravity field. In addition, the asymptotic representation for the Green function, in a layer of constant thickness is obtained. The validity of the approach for the calculation of the tsunami wavefield based on the Green function technique is verified comparing the results with those obtained from the modal theory, for a liquid layer of infinite horizontal dimensions. The Green function approach is preferable for the estimation of the excitation spectra, since in the case of an infinite liquid layer it leads to simple analytical expressions. From this analysis it is easy to describe the peculiarities of tsunami excitation by different sources. The method is extended to the excitation of tsunami in a semiinfinite layer with a sloping boundary. Numerical modelling of the tsunami wavefield, excited by point sources at different distances from the coastline, shows that when the source is located at a distance from the coastline equal or larger than the source depth, the shore presence does not affect the excitation of the tsunami. When the source is moved towards thecoastline, the low frequency content in the excitation spectrum ecreases, while the high frequencies content increases dramatically. The maximum of the excitation spectra from inland sources, located at a distance from the shore like the source depth, becomes less than 10% of that radiated if the same source is located in the open ocean. The effect of the finiteness of the source is also studied and the excitation spectrum is obtained by integration over the fault area. Numerical modelling of the excitation spectra for different source models shows that, for a given seismic moment, the spectral level, as well as the maximum value of the spectra, decreases with increasing fault size. When the sources are located in the vicinity of a shore, the synthetic mareograms calculated at distances greater than the source depth show that the maximum tsunami amplitude decays with decreasing source-to-shore distance. The rate of decay is dependent on the dip, length and depth of the fault. The tsunami intensity, defined as maximum peak-to-peak amplitude, decays with the inland distance of the source from the coast. At an inland distance equal to the source depth, it becomes 4?5 times less than that from a source in the open ocean. If the source is located under the coastline, the intensity of tsunami is approximately the same as for oceanic sources

    Métodos para evaluar interacciones entre cuerpos de agua en un humedal y aplicación en dos casos de estudio

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    La comprensión de la dinámica de ecosistemas dependientes del recurso hídrico subterráneo, como pueden llegar a serlo algunos humedales, parte del conocimiento del sistema hidrológico. Para alcanzar esta meta se aplica una serie de métodos y procedimientos de análisis que comprenden la caracterización hi-drogeológica, la delimitación del área de captura de agua hacia el humedal, el monitoreo piezométrico, la rea-lización de balances de masas. La modelación numérica, los análisis hidrogeoquímicos y los métodos isotópi-cos permiten refinar y validar los modelos conceptuales. En el marco del proyecto Hydrochemical and isotopic techniques for assessment hidrological proccesses on wetlands, promovido entre los años 2006 y 2011 por la Agencia Internacional de Energía Atómica (IAEA), Colombia y Argentina compartieron conoci-miento y experiencias para entender la dinámica de los humedales Ciénaga Colombia y La Salada. En este texto se resumen aspectos metodológicos y los resultados de los dos casos de estudio considerados.The Understanding of ecosystem dynamics, for example the wetlands, depends of the knowledge of the hydrologic system. Many techniques can be used in order to obtain a good conceptual mod-el of the wetlands and its catchment area: hydrogeology, numerical modeling, hydrogeochemestry, and iso-tope hydrology. researchers of Argentina and Colombia studied -According with the project: ―Hydrochemical and isotopic techniques for assessment hidrological proccesses on wetlands‖ (IAEA, 2006 to 2011)- two wet-lands hydrogeology dependent: La salada Pond and Cienaga Colombia Weltand. These projects used method-ologies similar and they obtained validated hydrological models

    Atypical ulcers: Diagnosis and management

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    Atypical ulcers show atypical clinical features, histology, localization, and resistance to standard therapies. The persistence of a chronic ulcer despite treatment with standard therapies requires a more specific diagnostic investigation. Diagnosis involves obtaining the history and performing clinical examination and additional tests. A skin biopsy is frequently used to confirm unclear diagnosis. In difficult cases, microbiological and immunohistochem-ical examinations, laboratory blood tests, or instrumental tests should be evaluated. The treatment of atypical wounds is characterized by local systemic therapy and pain control. Our results highlight the need for early diagnosis, and standardized and targeted management by a multidisciplinary wound healing center

    Energy Demand in Sugarcane Residue Collection and Transportation

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    Sugarcane production system is in transition, mainly due to its harvesting process. Harvest through burning has been gradually replaced by mechanized processes, providing another by-product to be explored: sugarcane trash. In Brazil, through of the sugarcane trash, São Paulo state itself produces around 210.4 million BOE – barrel of oil equivalent (1,251,952 TJ ), which could supply consumers through cogeneration or for further second generation ethanol. For the sugarcane trash to be collected, mechanized processes are required, such as windrowing, gathering, and transporting. In agricultural production systems, embodied energy is affected by the mechanization level. In order to assess environmental performance by the energy point-of-view, analysis of energy flows provides subsidies for the decision makers. Thus, this study aimed to determine the material and energy flows for sugarcane trash collection and to identify its critical steps. The sugarcane variety grown was RB855113, spaced between rows 1.4 m, in the second cut, and yield of 108 Mg ha-1. The following mechanized operations were evaluated: windrowing, gathering, and transport, using material and energy flow as supporting tools. Regarding the energy balance, sugarcane trash collection system is feasible. Among evaluated operations, gathering is the one that presented higher energy demand. Fuel in harvesting is the main factor that affects energy demand for having sugarcane trash available.   Keywords: material flow, mechanized harvest, bioenergy, biofue

    Surrounding skin management in venous leg ulcers: A systematic review

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    Objectives: Chronic venous insufficiency may lead to the development of venous leg ulcers, the most common form of chronic wounds in the lower extremity. Key to venous leg ulcer care is the maintenance of healthy skin surrounding the ulcer, as failure to maintain skin integrity may influence the healing outcome. We thus reviewed the scientific literature looking for assessment and management instruments regarding this common but often neglected issue. Method: The search included all studies published between 2000 and May 2019. Keywords used were: “peri-wound skin care”, “surrounding skin venous ulcers”, “surrounding skin management leg ulcers”, and “peri-lesional skin management”. Results: Management of moisture-balance with the selection of appropriate dressings is the most important target in surrounding-wound skin care. Moreover, contact dermatitis related to products and the dressings themselves is a neglected problem in patients with chronic leg ulcers which clinicians increasingly have to manage. The literature search revealed that there is an increasing interest in the use of noninvasive assessment tools in the field of wound care, and focusing on the surrounding-wound skin plays a role in assessing the potential of wound healing. Transepidermal water loss measurement (TEWL) and ultrasonography are two of the measurement techniques available. Conclusion: The integrity of the surrounding skin is necessary for wound healing, and appropriate management is needed to address this aspect which is part of an overall approach to treating wounds

    Energy Embodiment in Brazilian Agriculture: An Overview of 23 Crops

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    The amount of energy required to produce a commodity or to supply a service varies from one production system to another and consequently giving rise to differing levels of environmental efficiency. Moreover, since energy prices have been continuously increasing over time, this energy amount may be a factor that has economic worth. Biomass production has a variety of end-products such as food, energy, and fiber; thus, taking into account the similarity in end-product of different crops (e.g.: sunflower, peanuts, or soybean for oil) it is possible to evaluate which crops require less energy per functional unit, such as starch, oil, and protein. This information can be used in decision-making about policies for food safety or bioenergy. In this study, 23 crops were evaluated allowing for a comparison in terms of energy embodied per functional unit. Crops were grouped as follows: starch, oil, horticultural, perennial and fiber, to provide for a deeper analysis of alternatives for the groups, and subsidize further studies comparing conventional and alternative production systems such as organic or genetically modified organisms, in terms of energy. The best energy balance observed was whole sugarcane (juice, bagasse and straw) with a surplus of 268 GJ ha−1 yr−1; palm shows the highest energy return on investment with a ratio of approximately 30:1. For carbohydrates and protein production, cassava and soybean, respectively, emerged as the crops offering the greatest energy savings in the production of these functional foods

    Energy Demand in Agricultural Biomass Production in Parana state, Brazil

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    Energy flow analysis is an interesting approach to assess and to improve sustainability of agricultural production systems, represented by the economy of energy resources and other inputs translated into energy terms. This type of analysis can complement the economic view contributing to more efficient production systems. Moreover, assessing crops with traditional food use may play an important role in energy provision. Energy efficiency tools were applied in order to determine the energy demand as well as the efficiency of the biomass production of several forage crops in mechanized systems conducted at Paraná state, Brazil. Material flow, input and output energy, energy balance, energy return over investment and embodied energy were used and identified that maize and sorghum were the crops that uses energy in the most efficient way, represented by the best results at net energy availability, profitability and embodied energy at the final product. Oat and ryegrass were the crops the presented the least efficient energy uses in the biomass production systems.   Keywords: Bioenergy, energy indicators, sustainability, embodied energy. &nbsp

    Cutaneous Metastasis As The First Manifestation Of Occult Malignant Breast Neoplasia

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    Cutaneous metastases from primary internal malignancies represent 0.7-9% of patients with cancer. We report a 65year-old female patient referred for evaluation of normochromic papules on the trunk and upper limbs that had been present for three months. A skin biopsy revealed diffuse cutaneous infiltration by small round cell tumors. Immunohistochemistry was positive for AE1/ AE3, CK7, estrogen receptor and mammaglobin. The final diagnosis was cutaneous metastasis of occult breast cancer, since the solid primary tumor was not identified. The location of the primary tumor can not be determined in 5-10% of cases. In these cases, 27% are identified before the patient's death, 57% at autopsy, and the remaining 16% can not be located.915110510

    Synthesis of substituted flavones and chromones using a Wells-Dawson heteropolyacid as catalyst

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    In this work, we report the use of bulk and silica-supported Wells-Dawson acid (H2P2W18O62.24H2O) as reusable, heterogeneous catalysts to obtain substituted flavones and chromones for the cyclization of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones. The reaction experiments were performed using toluene as solvent at reflux and in the absence of solvent, at 110°C. Under these conditions eleven examples were obtained with very good yields (82-91%) and high selectivity. The catalysts were easily recycled and reused without loss of their catalytic activity. The presented synthetic method is a simple, clean and environmentally friendly alternative for synthesizing substituted flavones and chromones.Centro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ciencias Agrarias y ForestalesLaboratorio de Servicios a la Industria y al Sistema Científic
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