Sharif Digital Repository

Based on series of crude oil rheological properties and asphaltene flocculation confocal microscopy analysis, Najafi et al., (2011) reported the existence of an optimum radiation time at which asphaltenic crude oils reach the minimum kinematic viscosity. Accordingly, they proposed the idea of asphaltene flocculation inhibition due to wave radiation.The present investigation is a continuous effort to provide more information about the process of flocculation inhibition. Confocal microscopy and rheological analyses are performed on different crude oils to prove the repeatability of the observed phenomena. The asphaltene content analysis was done based on IP143 procedure, which provides more... 

In this study, it is aimed to compare the efficiency of ultrasonic wave technology on asphaltene flocculation inhibition of crude oils with different American Petroleum Institute (API) gravities. A set of confocal microscopy test is performed and a series of statistical analysis is done. According to the results of this study, there is an optimum radiation time for both crudes at which the viscosity and the flocculation rate of asphaltenic crude oils reduces to its minimum. This optimum appears at later times of radiation for extra heavy oil. Also, it is shown that the rate of changes in the properties measured in this study is sharper for extra heavy crude oil. It could be concluded that... 

The continued migration to smaller nanometer geometries brought fundamental limits to traditional on-chip hard wires performance. According to the International Technology Roadmap for Semiconductor (ITRS), feature size shrinking leads an increase in the operating frequency of RFCMOS devices. Thus, new interconnect methodologies such as radio frequency (RF) wireless can be employed on future chips projected for intra-chip wireless data communications. The size of Si integrated antenna in these frequencies will be several millimetres and the antenna length will be decrease by frequency increasing. In this paper, we have proposed an optimum radiation pattern achieved by a phased array (PA)...