Search results for " Solar"
showing 10 items of 958 documents
Synthesis and Photoelectrical Properties of 3-(Diphenylamino)Carbazolyl-Functionalized DMABI Derivatives
2019
A modular approach was used in the synthesis of the 3-(diphenylamino)carbazolyl- functionalized 2-(4-(dimethylamino)benzylidene)-1H-indene-1,3(2H)-dione (DMABI) derivatives. For this purpose, carboxyl functional group was introduced into the framework of DMABI molecule. Additionally, a regioselective method for substitution of carbonyl group of DMABI with dicyanomethylene group was investigated and verified using the heteronuclear multiple bond correlation NMR spectra. Steglich esterification method was used to connect the 3‑(diphenylamino)carbazolyl moiety via an unconjugated spacer. The UV-Vis absorption spectra and molecular energy level data were obtained for the evaluation of the synth…
Fabrication and Characterisation of Titania Photonic Nanostructures
2015
In this work, we report about the preparation and morphological characterization of photonic nanopatterned titania films (~ 200 nm).
Emission of Rhodamine B in PMMA opals for luminescent solar concentrators
2012
In conventional luminescent solar concentrators (LSC) incident light is absorbed by luminophores and emitted isotropically. Most of the emitted light is trapped inside the LSC by total internal reflection and guided to solar cells at the edges. Light emitted towards the surfaces, however, is lost in the escape cone. Furthermore, when the luminophore emits light in its absorption range, light is lost due to reabsorption. To overcome these losses, we embed the luminescent material in photonic structures to influence the emission characteristics. Directional and spectral redistribution of emission is supposed to enhance the light guiding in LSCs and reduce reabsorption losses. For this purpose…
Origin of SiO2-rich components in ordinary chondrites
2006
Abstract Silica-rich objects are common minor components in ordinary chondrites (OC), occurring as fragments and as chondrules. Their typical paragenesis is orthopyroxene + SiO 2 (with bulk SiO 2 >65 wt%) and occasionally with additional olivine and/or spinel. Individual silica-rich components (SRC) have previously been studied in various types of OCs, although there is only one comprehensive study of these objects by Brigham et al. [Brigham, C.A., Murrell, M.T., Yabuki, H., Ouyang, Z., El Goresy, A., 1986. Silica-bearing chondrules and clasts in ordinary chondrites. Geochim. Cosmochim. Acta 50, 1655–1666]. Several different explanations of how SRCs formed have been published. The main ques…
Alternatives to Methyl Bromide in strawberry cultivations
2009
Implantación de modelos tridimensionales de piel humana: Aplicación en la evaluación de los marcadores moleculares de la radicación solar
2022
La piel es el órgano más grande del cuerpo humano y está compuesta por tres capas desde el exterior hasta el interior: epidermis, dermis e hipodermis. Es la primera barrera que protege al cuerpo frente a gran variedad de factores ambientales estresantes, entre ellos, las radiaciones solares. La radiación solar es un espectro de longitudes de onda compuestos por la luz ultravioleta (UV), de la cual llega a la superficie terrestre una combinación de rayos UVB y UVA, el espectro visible (VIS), que tiene un rango que va desde la luz azul en el extremo más corto del espectro, hasta el rojo en el extremo más largo, y la luz infrarroja (IR), que se subdivide en tres regiones (IR-A, IR-B e IR-C). S…
La barca solar en el arte del antiguo Egipto
2009
Las embarcaciones han sido uno de los elementos básicos en el desarrollo y evolución de la civilización egipcia. Ampliamente utilizadas en la vida diaria por las especiales características geográficas del territorio, dieron el salto al ámbito del Más Allá convirtiéndose en vehículos de la divinidad a la vez que sirvieron de transporte a los difuntos en su tránsito al otro mundo. Este trabajo tiene como objeto mostrar la importancia de la barca en las concepciones egipcias, a lo largo de las diferentes épocas históricas de esta civilización, en relación a su significado e iconografía referida en especial a los ámbitos religiosos y funerarios, señalando las diferencias tipológicas que observa…
Assessment of Energy and Economic Effectiveness of Photovoltaic Systems Operating in a Dense Urban Context
2013
A methodology that permits testing the level of integration of the photovoltaic technology in urban areas is presented. The percentage of coverage of the electricity demand of grid-connected photovoltaic systems installed on the roofs of buildings were investigated in a district of the city of Palermo (Sicily). After classifying roofs according to their shape, orientation and pitch by means of satellite images provided by Google Earth, the ratio of the productivity of the PV systems and the consumption of electricity of the households was analysed. The results of the energy assessment have been screened considering the economic feasibility of grid-connected photovoltaic systems: the energy …
The optimisation of the angle of inclination of a solar collector to maximise the incident solar radiation
1999
Abstract Irradiation data, recorded on vertical surfaces facing north, south, east and west and on a horizontal surface every ten minutes during daylight hours from January–December 1992 in Valencia, Spain, have been compared with estimated solar irradiation from inclined-surface models. Results show that Hays model most accurately reproduces the variation in irradiation on all vertical surfaces. Hays model has been used to find the hourly variation in the optimum tilt angle for a South-facing solar collector in Valencia, Spain, and also to calculate the yearly average of this angle. This method has been compared with the results provided by another model that uses average monthly values of…
Innovative Compact Solar Air Conditioner based on Fixed and Cooled Adsorption Beds and Wet Heat Exchangers
2014
Abstract In this work, a new all-in-one compact solar air conditioner concept is presented. The system is mainly based on a new DEC process which utilises fixed and cooled adsorption beds operating in a batch process and two wet heat exchangers. The proposed innovative adsorption bed is a fin and tube heat exchanger commonly used in the air conditioning sector, wherein the spaces between the fins are filled with silica gel grains. The main feature of this component is to allow simultaneous dehumidification and cooling of air. Furthermore, since the component hosts a considerable amount of adsorption material, solar energy can be efficiently stored in the desiccant media in terms of accumula…