7,520 research outputs found
Ocular manifestations in the mucopolysaccharidoses - a review
No full textP>Ocular manifestations are very common in all types of mucopolysaccharidoses (MPS) and often lead to visual impairment. They arise as a result of the accumulation of glycosaminoglycans deposits in ocular tissues or secondary to increased intracranial pressure. Typical ocular features in MPS include corneal clouding, retinopathy, glaucoma, optic disc swelling, optic atrophy, and ocular motility and refractive error problems. This paper reviews the ocular features in patients with MPS, discusses the diagnosis of these ocular features and the diagnostic problems that may arise in patients (children) with MPS, and highlights the central role ophthalmologists may play in the diagnosis and follow-up of these patients
Influencia antrópica en la evolución del paisaje hidrológico de la planicie costera de Ajó (Argentina)
No full textLa planicie costera de Ajó forma parte del humedal de Bahía Samborombón (Argentina). Debido a la configuración morfológica y la presencia de suelos arcillosos estos humedales se inundan con frecuencia en periodos lluviosos. Con el fin de mejorar el drenaje, desde el siglo pasado se construyeron numerosos canales para favorecer la descarga de agua superficial hacia la bahía. Por otra parte, en las últimas décadas, se construyeron una serie de terraplenes y rutas para facilitar la conexión de los sectores de planicie aislados. Las imágenes satélites indicaron la presencia de un paleocauce cuyo curso se evidencia sólo en condiciones de alta humedad del suelo. Desafortunadamente, no hay mapas históricos para demostrar su ocurrencia. El objetivo del trabajo es evaluar cómo las obras de ingeniería condicionan la evolución del paisaje hidrológico en un sector de la planicie costera de Ajó. Para ello se efectuaron análisis de cartas topográficas e imágenes satelitales y relevamientos de campo. Los estudios realizados evidencian cómo las obras hidráulicas transversales al drenaje natural ocasionan la desaparición del curso. La parte distal del antiguo curso sufre procesos de sedimentación y se obtura, mientras que los sectores internos topográficamente deprimidos sin aporte de sedimentos forman cañadas.PublishedSanta Fe, Argentina6A. Monitoraggio ambientale, sicurezza e territorioope
Ecohidrología de un humedal intermareal antropizado: un estudio de caso en la Bahia de Samborombón (Argentina)
No full textEn los humedales intermareales los procesos hidrológicos y ecológicos están íntimamente
conectados, razón por la cual los cambios en la hidrología derivados de las actividades humanas pueden modificar los ecosistemas. En el humedal de la marisma del río Ajó la expansión ganadera dio a lugar a la realización de numerosos terraplenes que cortan los canales limitando la propagación del flujo mareal. El objetivo del trabajo es analizar cómo los cambios hidrológicos ocasionados por el hombre en la marisma pueden afectar la ecohidrología del humedal en relación al desarrollo de la vegetación. Se estudiaron las características hidrológicas y ambientales en áreas naturales y antropizadas a partir de observaciones de campo y medición de variables hidrológicas. Para evaluar las modificaciones en la vegetación se efectuó una estimación de los cambios estacionales en la cantidad, calidad y desarrollo de la misma a partir del análisis del índice de vegetación de diferencia normalizada (NDVI) en imágenes Landsat. Los resultados obtenidos evidencian que cerca de un 18% del área de marisma está actualmente fuera del ciclo mareal debido a las alteraciones antrópicas. En estas zonas el funcionamiento hidrológico natural fue modificado afectando el desarrollo de la vegetación intermareal típica de este ambiente y en consecuencia la ecohidrología del humedal.PublishedSanta Fe, Argentina6A. Monitoraggio ambientale, sicurezza e territorioope
Fe-Cluster Pushing Electrons to N‑Doped Graphitic Layers with Fe<sub>3</sub>C(Fe) Hybrid Nanostructure to Enhance O<sub>2</sub> Reduction Catalysis of Zn-Air Batteries
No full textNon-noble metal catalysts with catalytic
activity toward oxygen reduction reaction (ORR) comparable or even
superior to that of Pt/C are extremely important for the wide application
of metal–air batteries and fuel cells. Here, we develop a simple
and controllable strategy to synthesize Fe-cluster embedded in Fe3C nanoparticles (designated as Fe3C(Fe)) encased
in nitrogen-doped graphitic layers (NDGLs) with graphitic shells as
a novel hybrid nanostructure as an effective ORR catalyst by directly
pyrolyzing a mixture of Prussian blue (PB) and glucose. The pyrolysis
temperature was found to be the key parameter for obtaining a stable
Fe3C(Fe)@NDGL core–shell nanostructure with an optimized
content of nitrogen. The optimized Fe3C(Fe)@NDGL catalyst
showed high catalytic performance of ORR comparable to that of the
Pt/C (20 wt %) catalyst and better stability than that of the Pt/C
catalyst in alkaline electrolyte. According to the experimental results
and first principle calculation, the high activity of the Fe3C(Fe)@NDGL catalyst can be ascribed to the synergistic effect of
an adequate content of nitrogen doping in graphitic carbon shells
and Fe-cluster pushing electrons to NDGL. A zinc–air battery
utilizing the Fe3C(Fe)@NDGL catalyst demonstrated a maximum
power density of 186 mW cm–2, which is slightly
higher than that of a zinc–air battery utilizing the commercial
Pt/C catalyst (167 mW cm–2), mostly because of the
large surface area of the N-doped graphitic carbon shells. Theoretical
calculation verified that O2 molecules can spontaneously
adsorb on both pristine and nitrogen doped graphene surfaces and then
quickly diffuse to the catalytically active nitrogen sites. Our catalyst
can potentially become a promising replacement for Pt catalysts in
metal-air batteries and fuel cells
Precipitation of supersaturated solute in H ion irradiated Fe-Au and Fe-Au-W alloys studied by positron annihilation spectroscopy
No full textThe effect of thermal aging of homogenized Fe-Au and Fe-Au-W alloys, irradiated at room temperature with hydrogen ions, was studied for an aging treatment at 300 °C for aging times up to 100 h. The aging behavior of the Fe-based alloys is compared to the results for pure Fe. The precipitation behavior of Au-rich and W-rich precipitates and its correlation to the H+ irradiation-induced defects is investigated by variable energy positron annihilation spectroscopy (VEPAS). The formation of open-volume defects after irradiation is monitored by an increase in the S parameter, while the recovery of the vacancy-like defects and the formation of precipitates are signalled by an increase in the W parameter. Au-rich precipitation continuously develops during long-term aging, as indicated by the increase in the W parameter. The change of the W parameter in the Fe-Au-W alloy is not only due to the effect of solute W on the Au precipitates, but also because of the interface of W-rich Laves phase with matrix.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Novel Aerospace MaterialsRST/Fundamental Aspects of Materials and Energ
General Sheman's Visit to Santa Fe
No full textComments on an article by the Jesuits, concerning General Sherman's visit to Santa Fe, from Revista Catolica, October 12, 1878. Fight against the Jesuits, Catholic Church, comment on Bishop Lamy, St. Francis Cathedral, Protestants. Translated from Spanish to English. No sure of author? Document in English, 1 pp/fr, two pages per frame
Respuesta hidrológica del Bañado de Maldonado en la planicie costera del Río de la Plata: eventos extremos de abril de 2013
No full textOn April 2, 2013 unprecedented flash floods due to extreme rainfalls (approximately 400 mm in a few hours) occurred in La Plata and its surroundings causing loss of human live and great socioeconomic harm. The southeastern part of La Plata was an important flooded area. The lack of hydrological data at regional scale represents a significant constraint to the water management planning. This work aims to evaluate the hydrological response to the extreme precipitation events. Herein, we analyzed the satellite images acquired on April 5 (ASTER), April 9 (SPOT5), April 13 (Landsat7) and May 21, 2013 (SPOT5) and the topographical setting of the coastal plain. We suggest that the quantification of the evolution of the stored water in the low flooded areas of coastal plain is an indirect way to know the response of the coastal plain to the extreme precipitation events.PublishedSanta Fe, Argentina6A. Monitoraggio ambientale, sicurezza e territorioope
Respuesta hidrológica del Bañado de Maldonado en la planicie costera del Río de la Plata: eventos extremos de abril de 2013
No full textOn April 2, 2013 unprecedented flash floods due to extreme rainfalls (approximately 400 mm in a few hours) occurred in La Plata and its surroundings causing loss of human live and great socioeconomic harm. The southeastern part of La Plata was an important flooded area. The lack of hydrological data at regional scale represents a significant constraint to the water management planning. This work aims to evaluate the hydrological response to the extreme precipitation events. Herein, we analyzed the satellite images acquired on April 5 (ASTER), April 9 (SPOT5), April 13 (Landsat7) and May 21, 2013 (SPOT5) and the topographical setting of the coastal plain. We suggest that the quantification of the evolution of the stored water in the low flooded areas of coastal plain is an indirect way to know the response of the coastal plain to the extreme precipitation events.PublishedSanta Fe, Argentina6A. Monitoraggio ambientale, sicurezza e territorioope
Direct promotion effect of Fe on no reduction by activated carbon loaded with Fe species
No full textActivated carbon materials loaded with Fe species were prepared via an impregnation method and studied. Various analyses showed good dispersion of Fe species on the activated carbon surface when the loading amount did not exceed 2 g of iron(III) nitrate nonahydrate on 10 g of activated carbon. Additionally, the simultaneously existing forms of Fe species on the activated samples were found to be Fe3O4, FeO, and elemental Fe(0). NO reduction experiments under anaerobic conditions showed that the loading of Fe species enhanced the NO reducing ability from an NO conversion of (28 to 86)% at 850 degrees C, which is a more remarkable influence on NO reduction than that of the well-known C-O complexes. Thermodynamic analysis and detailed experimental results led to a new mechanism with two independent routes, both of which require Fe participation and proceed at temperatures below and above 800 degrees C, respectively, and generate different COx products. Furthermore, one of the routes was more efficient in reducing NO than the other. This mechanism explained the experiments much better than the existing C-O theory of complexes. (C) 2015 Elsevier Ltd. All rights reserved
Simultaneously Improved Bendability and Strength of Al–Mg–Si–Cu–Zn Alloys by Controlling the Formation and Evolution of Primary Fe-Rich Phase
No full textIn present work, the formation, evolution, and distribution of the primary Fe-rich phase in an Al–Mg–Si–Cu–Zn–Fe–Mn alloy are coupling controlled by ultrasonic melt treatment (USMT) and thermomechanical processing (TMP). It is shown in the results that the size of grains and Fe-rich phase in the as-cast state can be greatly reduced by the applied optimum USMT at 680 °C. Additionally, the transformation rate of β-Fe-rich phase to α-Fe-rich phase can be also enhanced. After the coupling control of USMT and TMP, the number density and distribution uniformity of multiscale Fe-rich particles can be greatly increased or improved, which contributes to the fine-grained recrystallization microstructure and weakened texture. Finally, compared with the 6xxx series Al alloys (such as AA6016 and AA6111), the alloy sheet in the pre-aging state exhibits substantially improved bendability and strength (the plastic strain ratio and tensile strength are 0.67 and 304 MPa, respectively). The effect of USMT on the formation and transformation of primary Fe-rich phase and the mechanisms of improved bendability and strength are deeply discussed.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Maria Santofimia Navarr
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