Sharif Digital Repository

In the first part of the thesis, we introduce the structure of a Nano-Newton CMOS-MEMS capacitive force sensor. This force sensor has been utilized out-of-plane sensing mechanism with high accuracy and reliability. Also, we discuss about sensitivity analysis of this force sensor. The largest change of capacitance (increased capacitance + decreased capacitance) occurs in ℓ=2/3. Sensitivity for increased capacitance grows by 8.33% and for decreased capacitance grows by 2.27%. The proposed method provides useful guidelines to increase the sensitivity of the sensor up to 250%. In the second part, a fixed structure controller, PID type, is proposed to control and suppress the in-plane vibration... 

Biosorption capacity of zinc (II) by biomasses produced from four species of microorganism including two kinds of bacteria (Pseudomonas putida and Streptomyces rimosus) and two kinds of fungi ( Aspergillus niger and Phanerochate chrysosporium) in batch case were investigated and compared. In all cases dried original bio mass and dried pretreated bio mass with NaOH were used. In all cases biosorption capacity of pretreated biomasses were much higher than non-treated biuomasses to the ratio of 3.8 – 1.4 times. Freundlich and Langmuir equilibrium isotherms were used to match with experimental results of this research. Except S.rimosus, all others were completely matched with Langmuir... 

Labneh is a semisolid product that is produced by concentrating milk to approximately 23% total solids (wt/vol) by the traditional cloth bag method, ultrafiltration and direct reconstitution. For ultrafiltration membrane processing is carried out either before or immediately after fermentation. The effect of storage time on the flow properties of concentrated yogurt (labneh) was investigated using a rotational viscometer. Experiments were performed at after 0, 2, 5 and 14 days after production. The apparent viscosity of fresh sample was then measured as a function of shear rate. For a given shear rate, the apparent viscosity was measured as a function of shearing time. The increase in the... 

The ever-increasing volume of data and the lack of computational and storage facilities have caused a managerial challenge to organizations. The existence of these challenges on the one hand and the increase of storage services on the other hand have compelled the organizations to delegate their storage and management of data to the server providers of cloud storage services. The outsourcing of data to servers obviates the need for purchasing exorbitant storage equipment and recruiting professional workforce in the organization. Since the organization’s data will be kept outside the organization’s ambience in case of using such services in form of outsourcing, and the data will not be under... 

Autism Spectrum Disorder (ASD) is a group of neurodevelopmental disorders that cause repetitive behaviors and social and communication skills abnormalities. Autistic Disorder(AD) is one of the disorders in ASD that is being investigated in this study. There has been an increase in research about AD in recent years due to the increasing AD prevalence and the high autistic living costs. The dynamic functional connectivity between healthy and autistic groups has been analyzed by using graph theory. The brain is modeled as a dynamic graph using resting-state fMRI. The graph theory metric is calculated in the dynamic graph of each subject, and the distinction of the two groups is checked using... 

Food rich in antioxidants plays an essential role in the prevention of diseases and plum is an example of these food .Our objective in this research was to determine the amount of variation in total phenolic compound present in plum fruits, so that it can be utilized in breeding programs to enhance the health benefits.Total phenolic content of the fruits, which were determined in 7 genotypes by using 4 solvents (water , methanol , ethanol , acetone) to extract phenolic compound, ranged from 178 to 497 mg/100 gr for methanol, from 306 to 407.33 mg/100 gr for ethanol , from 300 to 392 mg/100 gr for acetone and from 193 to 281.25 mg/100 gr for water. The results show that the methanol... 

Fats and oils are one of the main human food diet components that provide the necessary fatty acids for our body. So the fatty acids available in consuming oils are so important. In this research the mixture of palm and sunflower oils with different compounds: (80:20, 60:40, 50:50, 40:60, 20:80) were used for preparing free- trans shortening by interesterification. For this purpose a special stabilized lipase (Lipozyme TLIM) were used and performed the physicochemical properties: free fatty acids, peroxide value, iodine value, slip melting point, solid fat content, P-anisidine value, soap, oxidative stability at 110 0C, and the profile of fatty acids on the primitive blends and final samples... 

In this thesis, TTL-1 thermo hydraulic test loop which was constructed in the Nuclear Science and Technology Research Institute (NSTRI) has been modified. These modifications include changing core section from one fuel rod to a fuel assembly with triangular arrangement, adding a pressurizer on the hot leg of loop, an accumulator, LOCA valve and installation of new sensors for upgrading of data acquisition system and modification of loop piping design. By these modifications, we will able to study different accidents such as LOHA, LOFA and LOCA and validate nuclear thermo hydraulic codes. Moreover, this new thermo hydraulic test loop (TTL-2) has been modeled by RELAP5/MOD3.2 in order to... 

In this survey the TTL-1 thermal hydraulic test loop in Nuclear Science and Technology Research Institute (NSTRI) has been modified to study thermal hydraulic phenomenon in research reactor thermal condition. These modifications include: replacing the test section containing a single heating rod by a group of 31 rods in a triangular array, relocating the pressurizer from the cold leg to the hot leg and improving piping of the test loop. In order to measure the time dependant flowrate of the coolant, a rotameter flowmeter is added. Three level meter measure the water level in pressurizer, test section and the primary loop drain tank and a 3-phase AC inverter controls the rotational speed of... 

A prismatic high temperature gas-cooled reactor (HTGR), which is a graphite moderated, helium-cooled reactor, is a promising candidate for next generation nuclear power plant in that it enables applications, such as hydrogen production or process heat for petrochemical by supplying heat with core outlet temperatures as high as 1000°C. A Thermal Hydraulic Analysis Code (THAC) for gas-cooled reactors has been developed. THAC implicitly solves heat transfer equation of fuel, graphite block and helium. Three types of fuel pins were considered; solid fuel pin, fuel pins with inside holes and annular fuels with coolant flow from its inside and outside surfaces. THAC predicts axial and radial... 

In this work the large break loss of coolant accident at Boushehr Nuclear Power Plant (NPP) has been studied. At first, primary and secondary side’s components which play important role in the accident have been modeled using RELAP5/MOD3.2 GAMMA system code. The components are: reactor pressure vessel, main pipe lines, main coolant pumps, pressurizer, steam generators, steam lines, emergency core cooling accumulators, boron solution supply tanks and pumps (LP& HP) and KWU accumulators. After preparing the input file and running the code, thermal hydraulic properties such as radial distribution of temperature in fuel rods, temperature distribution in steam generator primary and secondary... 

High temperature gas cooled reactors (HTGR) are one of the most promising reactors in the new generation of world commercial reactors. They are divided into two main categories: Prismatic gas cooled reactors and pebble bed gas cooled reactors. These reactors have many advantages, such as inherent safety, high thermodynamic efficiency and the possibility of producing hydrogen. One of the most important challenges in developing these reactors is providing appropriate codes in design and simulating their performance. Two codes have been developed in this thesis. The first, THFAM, is a steady state thermal hydraulic code which helps in analyzing a fuel assembly. The second, named THCM is... 

Fluorapatite (FA) has been widely used on orthopedic and dentistry prosthesis due to its excellent bioactivity properties. Therefore, the aim of this work is to prepare and characterize copper doped nanostructured fluorapatite powder via mechanical alloying (MA) method using a high energy planetary ball mill.FA powder samples with the general chemical formula Cux.Ca(10-x).(PO4)6.F2 (where x is the ratio of substitution of Cu-2 by F−1) are successfully synthesized using the starting materials of calcium oxide (CaO), phosphorous pentoxide (P2O5), calcium fluoride (CaF2), and copper (II) oxide (CuO) powders under various milling times. In order to evaluate the antibacterial effect of copper,... 

Research on convective heat transfer coefficient around a rod bundle has several applications in industry. So far, many studies have been conducted in correlations related to internal fully developed flow. By comparing Dittus-Boelter, Sieder-Tate and Petukhov found to be more practical. The present study examines the validity of these frequently applied correlations experimentally. A thermohydraulic loop has been designed and manufactured to test and measuring the convective heat transfer coefficient. Due to its generalizibility, the unique geometry of this test facility (hexagonal arranged, 7 vertical rods in a hexagonal tube) has achieved extensive application. The major deviation factors...