Sharif Digital Repository

In recent years, global salt lakes have faced severe environmental challenges. Lake Urmia, the world’s second-largest hyper saline lake, is located in the northwest of Iran, has experienced a significant shrinkage in last years. Lake Urmia is a terminal lake where water enters through precipitation and rivers inflow and loses through evaporation. Analysis of long-term trends (1990-2018) using the Mann-Kendall test indicates no significant trend in precipitation, an increasing trend in evaporation, and a decreasing trend in river discharge. However, precipitation during 1990-1999 (beginning of accelerated lake drying) showed a decreasing trend. An investigation of the correlation between... 

In this research the behavior of Circular Steel Tubes (CSTs) with corrosion under axial force and bending have been studied. There are several factors leading to corrosion in steel structures, especially marine structures that results in strength reduction of whole structure. Steel tubes are widely used in construction of on-shore and off-shore structures such as, oil rigs and platforms, oil and gas transmission lines. Current study focus on strength reduction of steel tubes with “pitting corrosion”. To this end numerical analyses using finite element software, Abaqus, have been performed. Therefore, utilizing verified models, the simultaneous effect of bending, axial load and corrosion on... 

The PM2.5 particles are considered as one the most important pollutants of Tehran’s air due to their undesirable effect on health and environment. The particular matters which are in Tehran’s air are distributed from different sources. Because of lack of sufficient data about amount and chemical compounds of such matters in different areas, this study considers only concentration of particular matter and their composing elements in Sharif University, Tehransar, Mahalati, and Shahriyar station. By use of field measuring between 2015 to 2016 mass concentration of PM2.5 pollutant was calculated and then with the help of IC, GC/MS, and ICP chemical analysis which were conducted in University of... 

In recent years, the possibility of building large systems on chip, called SoC is provided. By scaling the technology, designing Socs will face numerous challenges. The Noc paradigm, has resolved many of the SoC’s problems, by deploying network properties in the structures of on chip interconnections. Today, with advances in the semiconductor industry, we can implement broadband wireless antennas, which are integrated on chip. Such NoCs are called WNoC. Due to immaturity of WNoCs, there still exist big challenges, providing routing algorithm and controlling shared medium via MAV layers, for them. In this project, we will provide a routing algorithm based on tag switching, and then, after... 

Knee pain and injuries are very common in athletes. Anterior cruciate ligament (ACL) injury is one of the most important reason of knee acute and chronic pains. As ACL plays a significant role in knee stability and due to amount of reported ACL related injuries, much effort has been placed on finding proper and on time diagnosis and treatment of these injuries. Arthrometric methods are the most non-invasive reliable diagnosis option; however they are not fully capable of separating partial injuries from intact joint. This weakness can be investigated by quantifying the tests using computer simulations; so far few studies have been conducted toward this goal. In this study a two dimensional... 

If we accept that there is a thing called “religious Science”, then we should accept that, all of its scientific elements should be based on, or be compatible with religion (in its general meaning). So, here is the question: Is there a particular “religious methodology” required for the “religious science”? Does “religious”, as an adjective also applies to methodology of science? Anyway, if we want to generate “religious science” based on religious foundations, we should characterize our position about “methodology of religious science”. Negligence of this important subject would cause a theoretical vacuum in discussions about religious science. In this thesis, after explaining some general... 

In this study Ni-P-Al2O3-SiO2 nano composite coating developed on aluminium alloy 6061 using electroless method. Due to oxidation of aluminium, a double zincate pretreatment performed to obtain proper adhesion of coating on substrate. Effect of solution temperature and heat treatment on thickness and property of nano composite coating was studied. Furthermore, effect of concentration of nano particles in electroless solution on thickness, morphology, micro hardness, wear behavior, corrosion resistance and particle content in coating were investigated. Field emission scanning electron microscopy (FESEM, Hitachi S-4160) with energy dispersive spectroscopy (EDS) was used to evaluate morphology... 

Immensity and profundity of mathematical logic have provided an opportunity for its interconnection with other branches of science, one of which is computer science where theory of dependent types and lambda calculus lounges amongst the area of their overlap. The former has been engendered for the sake of deepening the connection between mathematical logic and programming. On the other side, lambda calculus which is a formal system in mathematical logic and computer science, developed as a tool for formal computations, could also be counted as a programming discipline. It is the objective of this thsis to study the two aforementioned fields with emphasis on unification of higher-order... 

In the last three years, the lives of many people around the world have changed with the spread of the Corona virus. In order to better manage the consequences related to the spread of this disease, extensive research has been done on this virus, and researchers in data science and artificial intelligence have devoted a part of their research to studying the effects of this virus on the people in one or different societies.On the other hand, the study of social networks about a specific issue or trend topic, allows us to examine more closely the atmosphere that governs the society and analyze the emotions, feelings and the level of concern of the members of the society about that issue.The... 

Both handling and ride comfort play an important role in the performance and quality of a vehicle, and all the vehicle companies in addition to power and transmission system, pays special attention to these properties in the way of improving their products. This thesis is performed with the aim of study on effects of rubber bushing's characteristics of suspension system on handling behavior of a homeland built vehicle (pride). Role angle, slip angle, yaw rate and lateral acceleration are interrelated and are important quantities in studying on handling behavior of a vehicle. We have chosen slip angle as one these quantities and studied on effects of rubber bushing's characteristics on slip... 

The removal of glyphosate, one of the most widely used herbicide, with membrane bioreactor (MBR) was studied. Beside of glyphosate, the synthetic wastewater contained molasses and other salts as nutrient source. The membrane was made from polypropylene and was immersed in the bioreactor. The COD of the feed was adjusted by varying the ratio of glyphosate to molasses. The total COD was 500, 750 and 1000 mg/L. The resulted showed that when the bioreactor coupled with membrane the removal efficiency increased. The increase was attributed to higher concentration of biomass or MLSS in the MBR. The average of MLSS in the MBR was 8500 mg/L while in bioreactor without cell recycling and in batch...