Sharif Digital Repository

The reaction of O2N2-donor naphthodiazacrown, with salicylaldehyde afforded new O3N2-donor macrocyclic ligands (L1-3naph) mounted with 1,3-diazcyclohexane subring in high yield. The product was characterized by IR, 1HNMR spectroscopy as well as elemental microanalysis and single crystal X-ray studies (just for L3naph). The interactions of [60]fullerene in presence and absence of base, Cu(II), Hg(II) and Zn(II) with L1-3naph were investigated employing fluorescence spectroscopy. The efficient fluorescence quenching of L1-3naph in presence of C60, Cu(II)( L1-2naph) and the fluorescence enhancement in presence of Hg(II) and Zn(II) indicated that the interaction with [60]fullerene Hg(II) and... 

In this treatise, the effect of type of macrocycle ring on the final structure of the complexes which made from them was investigated. For this purpose, by changing the 15-membered benzylic macrocycle with two pyridine pendant arms (2p), which was studied in our previous experiments (the effect of the position of the nitrogen atom of the pyridine ring in the side arm and the type of metal ion in the geometry of its complexes), two new macrocycles by adding a naphthalene rings instead of benzylic ringsin in 2p and increasing the ring size from 15 to 17 members, Lpy-naph and Lpy-benz were symthesized respectively. The molecular formula and structure of Lpy-naph and Lpy-benz were confirmed by... 

In this work a new innovative microfluidic system for the selection of motile sperms was developed. The novel aspect of this work is based on the fact the motile sperms follow microchannel walls. Immotile sperms are not able to follow curved paths and therefore their movement toward the outlet gets hindered and most of them could not reach to the outlet. But motile sperms, moving alongside the microchannel walls, reach to the outlet and get separated from the immotile ones. After designing, 3 microfluidic chips having curved microchannels with curvature radius of 150, 300 and 600 micrometer and one with a straight microchannel were fabricated using photolithography and soft lithography.... 

Parkinson's is a disease caused by a disorder in the central nervous system of the body. There is no definite cure for this disease, but one of the ways to prevent the progress of this disease is to use movement therapy. One of the goals of designing wearable systems consisting of inertial sensors is to make it possible to perform this movement therapy from a distance. The purpose of the present study and research is to use the approach of simple and complex activities in order to increase the accuracy in the detection of activities and also to solve the problems of the previous system, with the help of creating the ability to detect complex meaningful activities for Parkinson's patients. In... 

In the recent decades, Polymer Electrolyte Membrane Fuel Cells (PEFC) have been known as an appropriate type of fuel cells, due to being electrochemical converter and clean energy generator with high power density and having low operation temperature and launch time. Palatine is one of the major materials that are used in electro-catalysts of fuel cell. Due to shortage of palatine resources and its high price, fuel cell production is not economical. To achieve economic conditions for production of fuel cell, two major methods are proposed:
1) Reduction of the employed amount of palatine in electro-catalyst
2) Full replacement of palatine with cheap materials
In the current... 

Solid-State Drives (SSDs) provide high performance, low power consumption, and hence are widely used in the I/O cache of enterprise storage systems and high performance servers. Although employing high performance SSDs in the I/O cache of storage systems significantly improves system performance, it comes with significant reliability threats for write operations upon power failures. In order to provide high level of reliability, storage architectures employ SSDs in I/O cache with RAID-1 configuration, however, such configuration only partially mitigates the reliability issues of the SSDs. In this thesis, we analyze the reliability of SSD-based I/O caches against power outage and high... 

With increasing rate of digital information in the world, design, configuration, and networking of enterprise storage systems has become an essential part in designing data centers. The performance of data storage systems in serving incoming requests is one of the major parameters of such systems. A major metric to measure performance is response time. This parameter is, in particular, crucial in enterprise applications such as financial, credit, multimedia, and real-time applications. A common approach to enhance the performance of enterprise storage systems is improving the hit ratio of the system global memory using prefetching technique. Using prefetching technique, a data block is... 

Nowadays, enterprise storage systems are widely used in data centers such as databases, servers, and bank institutes. Due to mechanical activity of disk drives, these systems are one of the most power consumptive components in data centers. Prefetching and RAID, which are employed to enhance performance, are widely used in data storage systems. These two methods, however, impose significant energy overhead to the system due to the increased disk activity. In this thesis, we first elaborate shortcomings of prefetching and RAID methods. Then, we propose a new energy efficient and RAID-compatible prefetching method (LPTAP), which aims at improving performance and energy consumption. To evaluate...