Microstructure of GaN Grown on (111) Si by MOCVD

Gallium nitride was grown on (111) Si by MOCVD by depositing an AIN buffer at 108O"C and then GaN at 1060 {degrees}C. The 2.2pm layer cracked along {1-100} planes upon cooling to room temperature, but remained adherent. We were able to examine the microstructure of material between cracks with TEM. The character and arrangement of dislocation are much like those of GaN grown on Al{sub 2}O{sub 3}: -2/3 pure edge and - 1/3 mixed (edge + screw), arranged in boundaries around domains of GaN that are slightly disoriented with respect to neighboring material. The 30 nm AIN buffer is continuous, indicating that AIN wets the Si, in contrast to GaN on Al{sub 2}O{sub 3}

Solvothermal Synthesis, Structure and Optical Property of Nanosized CoSb3 Skutterudite

Binary skutterudite CoSb3 nanoparticles were synthesized by solvothermal method. The nanostructuring of CoSb3 material was achieved by the inclusion of various kinds of additives. X-ray diffraction examination indicated the formation of the cubic phase of CoSb3. Structural analysis by transmission electron microscopy analysis further confirmed the formation of crystalline CoSb3 nanoparticles with high purity. With the assistance of additives, CoSb3 nanoparticles with size as small as 10 nm were obtained. The effect of the nanostructure of CoSb3 on the UV–visible absorption and luminescence was studied. The nanosized CoSb3 skutterudite may find application in developing thermoelectric devices with better efficiency

Solvothermal Synthesis, Structure and Optical Property of Nanosized CoSb3 Skutterudite

Binary skutterudite CoSb3 nanoparticles were synthesized by solvothermal method. The nanostructuring of CoSb3 material was achieved by the inclusion of various kinds of additives. X-ray diffraction examination indicated the formation of the cubic phase of CoSb3. Structural analysis by transmission electron microscopy analysis further confirmed the formation of crystalline CoSb3 nanoparticles with high purity. With the assistance of additives, CoSb3nanoparticles with size as small as 10 nm were obtained. The effect of the nanostructure of CoSb3on the UV–visible absorption and luminescence was studied. The nanosized CoSb3 skutterudite may find application in developing thermoelectric devices with better efficiency.

Size Distributions of Gold Nanoclusters Studied by Liquid Chromatography

The authors report high pressure liquid chromatography, (HPLC), and transmission electron microscopy, (TEM), studies of the size distributions of nanosize gold clusters dispersed in organic solvents. These metal clusters are synthesized in inverse micelles at room temperature and those investigated range in diameter from 1--10 nm. HPLC is sensitive enough to discern changes in hydrodynamic volume corresponding to only 2 carbon atoms of the passivating agent or metal core size changes of less than 4 {angstrom}. The authors have determined for the first time how the total cluster volume (metal core + passivating organic shell) changes with the size of the passivating agent

Financial assessment of the restoration and maintenance of the Historic Garden “El Huerto de las Bolas”

[SPA] En este estudio se ha realizado un análisis de viabilidad económica de la restauración y puesta a punto de un bien público, como es el caso del Jardín Histórico “El Huerto de las Bolas” en la ciudad de Cartagena. Para este análisis se ha aplicado la metodología de análisis coste beneficio en tres escenarios de duración: corto (3 años), medio (5 años) y largo (10 años) plazo. Los resultados muestran que los tres escenarios son viables económicamente, situándose el plazo de recuperación de la inversión por debajo de los 3 años. De estos resultados se deduce que los beneficios derivados de la recuperación de este espacio verde urbano histórico son superiores a los costes de inversión y mantenimiento. De esta manera, un estado paisajístico del jardín óptimo, no solo es viable económicamente, sino que pone en valor los beneficios que proporcionan los servicios del mismo. [ENG] In this study an economic viability analysis of the restoration and maintenance of a public good, such as the historical garden “El Huerto de las Bolas”, in the city of Cartagena, was carried out. For this analysis, the cost-benefit analysis methodology was applied for three scenarios with different time duration: short (3 years), medium (5 years) and long term (10 years). Results show the three scenarios are economically viable, with a Pay Back Period below 3 years. From these results, we can deduce that the benefits derived from the restoration and maintenance of a historical urban green space are greater than the costs of investment and maintenance. This way, an optimal state landscape of the garden is not only economically viable, but also enhances the benefits provided by its services

Maintenance cost analysis of the Historic Garden “El Huerto de las Bolas”

[SPA] El análisis económico del mantenimiento de un jardín público en un contexto específico es un tema poco abordado en la literatura científica y poco cuestionado por la sociedad. En este sentido, el objetivo de este trabajo es analizar de los costes de mantenimiento de un jardín público con un mantenimiento diferenciado por su condición de Jardín Histórico y Bien de Interés Cultural como lo es “El Huerto de las Bolas” en Cartagena. Para ello, se realiza un análisis de costes a partir de información obtenida del trabajo de campo realizado y de una valoración a precios de mercado. Los resultado muestran un coste de mantenimiento de 162.689 €/año, de los cuales 24.109 €/año corresponden a costes fijos, 105.173 €/año a costes variables y el resto a intereses e impuestos. Estos resultados arrojan un coste por superficie de aproximadamente 4,2 €/m2 que, aunque es un valor inferior al de la media del Municipio (~5€/m2), resulta un valor razonable y dentro de un coste lógico para cualquier jardín de dimensiones similares. [ENG] The economic analysis of a public garden maintenance within a specific context is an issue very little dealt with in scientific literature and little questioned by society. In this sense, the aim of this work is to analyze the maintenance costs of a public garden having a differentiated maintenance due to its condition of Historic Garden and Asset of Cultural Interest (BIC in Spanish), as it is the case for the garden “El Huerto de las Bolas” in the city of Cartagena. For that purpose, a cost analysis methodology has been used, whose information corresponds to work done on site and a valuation based on market prices. Results show a maintenance cost of 162,688.59 €/year, from which 24,109 €/year correspond to fixed costs, 105,173 €/year correspond to variable costs and the rest to financial interests and taxes. These results bring a unitary cost of about 4.2 €/m² which, although it is a value below the average of the Township (~5 €/m²), it is a reasonable one and fits in the logical cost of any other garden with similar dimensions