Sharif Digital Repository

Design and fabrication of solar collectors with high performance of energy efficiency to convert solar energy to utility energy is vitally important. This article reports the results obtained from design, construction and investigation of the performance of a Combined Multi-Purpose Vacuum Solar Collector (CMPVSC). This collector consists of three sections: the vacuum section, the liquid section and the air section. In the present collector, it is capable of transferring heat to two flows (liquid and air) simultaneously and separate with the possibility of multipurpose applications. The CMPVSC is compared with the existing individual collectors and the effects of different parameters on the... 

It has been shown that one kind of poly silicon particles with sizes ranging from 10-500 nm, can be used in oilfields to enhance the oil recovery of water injection by 15-20%. The contributing mechanism might be reducing the interfacial tension which appears through improving relative permeability of the oil-phase. However, fundamental understanding of how hysteretic behavior of relative permeability curves affected by nanosilica particles remains a topic of debate in the literature. In this study, water as well as water dispersed nanosilica particles floods was performed on sandstone rock sample saturated by light crude oil supplied from one of Iranian oil reservoir, and the relative... 

This research investigated the long-term environmental effects on bond strength at the interface between fiber- reinforced polymers (FRPs) and timber. A total of 581 timber specimens were bonded with seven types of FRP sheets (unidirectional and bidirectional glass, carbon, aramid, and hybrids) using a wet lay-up technique. The specimens were exposed to acidic, alkaline, fresh water, and sea water solutions with pH of 2.5, 7, 7.25, 10, and 12.5 for 1, 3, 6, 9, and 12 months. A chamber was also used to simulate ultraviolet radiation after 6 months. A series of single-lap shear tests were then conducted to determine the interfacial bond strength reduction. The results showed that bidirectional... 

It has been shown that one kind of poly silicon particles with sizes ranging from 10-500 nm, can be used in oilfields to enhance the oil recovery of water injection by 15-20%. The contributing mechanism might be reducing the interfacial tension which appears through improving relative permeability of the oil-phase. However, fundamental understanding of how hysteretic behavior of relative permeability curves affected by nanosilica particles remains a topic of debate in the literature. In this study, water as well as water dispersed nanosilica particles floods was performed on sandstone rock sample saturated by light crude oil supplied from one of Iranian oil reservoir, and the relative... 

In this study, tungsten oxide films were synthesized by pulsed laser deposition (PLD) method. The as-deposited films were annealed at a temperature of 250 and 350°C in air for 1 h. The surface morphology, microstructure, crystalline phase and chemical composition of the as-prepared and annealed films were characterized by SEM, XRD and XPS techniques, respectively. Deposition of Pd nanoparticles onto the tungsten oxide surface was performed by hydrogen reduction of a drop-drying PdCl 2 solution onto a WO 3 surface at 60°C. The influence of the annealing temperature on microstructure and gasochromic performance as well as the effect of operating temperature is presented in this work. Results... 

Core-shell iron-gold (Fe@Au) nanoparticles were synthesized by a facile reverse micelle procedure and the effect of water to surfactant molar ratio (w) on the size, size distribution and magnetic properties of the nanoparticles was studied. MTT assay was utilized to evaluate the cell toxicity of the nanoparticles. To functionalize the particles for MRI imaging and targeted drug delivery, the particles were coated by polyglycerol through capping with thiol followed by polymerization of glycidol. The characteristics of the particles were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometere (VSM), UV-visible spectroscopy, and Fourier...