Sharif Digital Repository

Entrance of secular science to Muslim societies has made them face a duality. That is because, on the one hand, they like to preserve their religious values; and on the other, prevalence of secular ideas prevents people from being committed to such values. Therefore, some Islamic scholars proposed religious science as opposed to Western secular science as a remedy to this crisis In case of religious science, explanatory model has the highest position, but disagreement over how to combine experimental and religious characteristics has led to different models in this area. One of the explanatory models of religious knowledge is that of Doctor Mehdi Golshani which has received due attention at... 

Monopiles are large-diameter with a typical diameter of 2 to 10 meters that are used for the base of offshore wind turbines. During its life, this structure is subjected to wind, wave, and sea currents, and due to the lateral displacement of the monopile, the wind turbine base structure with a considerable height can create the effect of "P-Δ". Therefore, accuracy in modeling and accurate estimation of monopile displacements and rotations is important. At present, the lateral design of monopiles is based on force-displacement (p-y) curves. P-y curves are semi-empirical curves based on experimental results obtained on piles with a diameter of less than one meter in different soils and under... 

The bladder is one of the most important internal organs of human that improper functioning of this organ causes various diseases such as bladder exstrophy, bladder syndrome, bladder cancer and bladder infection. The main challenge in treating these diseases is the presence of a mucous layer consisting of glycosaminoglysis (GAG) in the bladder wall that prevents drugs from reaching the surface of the bladder. Hence, drug delivery through the mucosal layer is not easy, Hence, urease micro/nano carriers have recently been considered for the treatment of bladder diseases. In this study, new janus micromotors based on black titanium oxide with asymmetric urease catalytic coating were synthesized... 

Optimum railroad alignment, which can be categorized into continuous problems, has been a conundrum for engineers because of two reasons: At the first, there is a wide variety of information that is necessary for finding optimum one. Secondly, the major costs of a railway, such as length-dependent, traffic-dependent, volume-dependent and location-dependent are affected by the numerous factors so that, it may be difficult to formulate them. In order to solve large scale continuous optimization problems, there are two approaches: firstly, such problems may be tackled with a combinatorial optimization algorithm, e.g. ant colony optimization (ACO), by the continuous range of allowed values are... 

Regarding the existing contrary in the literature in relation to the effect of plastic fine on sand liquefaction behaviour, we decided to study this effect. Amounts of 5, 15, and 25 percent of two types of plastic fine, Kaolinite with PI=19 and Bentonite with PI=116 added to Firoozkooh Sand and 68 stress controlled tests were conducted using cyclic simple shear apparatus. In all teste the frequency of shear loading and consolidating vertical effective stress were constant and 0.1 Ht and 100 kPa respectively. Reaching excess pore water pressure ratio to the maximum value (r_u=Max) and reaching double amplitude shear strain to the value of 5% have been considered as liquefaction critera. In... 

increased cohesion up to 4H pencil. Results of immersion test in water showed stability of coatings. Polarization test in naphtha and water mixture for stainless steel, copper and aluminum meshes demonstrated 98.89%, 86.25% and 66.6% protection efficiency respectively. In order to study of oil and water separation efficiency, mixtures of water and naphtha with different content of naphtha were used. Separation test for 200μm St.St mesh in different slopes demonstrated that changing of slop increase separation efficiency up to 95.5% for water and up to 100% for naphtha. Separation test for meshes with different pore size demonstrated that meshes with small pore size are more appropriate for... 

The railroad blocking problem emerges as an important issue at the tactical level of planning in freight rail transportation. This problem consists of determining the paths of each shipment which minimize the total cost subject to the key constraints such as limitation on travel time, limitation on number of dispatched trains, and limitation on the number of cars classified at each station. The multi-path railroad blocking model is developed and then a new heuristic algorithm based on the Lagrangian relaxation technique to solve the realistic rail network is introduced.To consider the uncertainty which is inherent in the demand and travel time (as a supply indicator of rail system), a... 

Vortex-induced vibration is a known phenomenon in fluids flow that is being studied in different fields of engineering and usually, we want to reduce the harmful effects of this phenomenon on the subjected structures. Also, it is possible to use this phenomenon for harvesting clean energy from fluids flow. Energy harvesting from vortex-induced vibrations is based on the maximizing of flow instead of its reduction, and the utilization of these vibrations instead of their suppression. Vortex induced vibrations occur in any ranges of Reynolds numbers. Only in three transient regions cause a reduction in vortex-induced vibrations; therefore, even in streams with a velocity less than 0.2 m/s, it... 

The aim of this work is to design, build and test a laboratory scale flameless combustion chamber. Also, a theoretical model is developed to simulate flameless combustion with a simple model. Flameless combustion is a combustion type with transparent flame which consumes less fuel than typical premix and diffusion flames and emits very low level of NOx. In flameless combustion, recirculation ratio is higher than typical diffusion flames so the flow field is highly turbulent. High recirculation ratio causes low oxygen concentration in combustion zone; thus requiring inlet air to be preheated for flame stabilization at low equivalence ratio and oxygen concentration. We have designed a... 

Solid State Drives (SSDs) have an electronic architecture based on non-volatile memories. The unique merit of a SSD is its internal parallelism. Thus, adopting SSDs as the storage media in the storage systems in various devices, such as smart phones, personal computers, large workstations, and etc., improves the performance of the device, substantially. However, the conventional host interface protocols in SSDs, i.e. SATA and SAS, have critical limitations, like low bus bandwidth (maximum 12Gbps), and a single shared request queue. With such limitations, the host interface turns into a performance bottleneck in conventional SSDs. Therefore, the high performance provided by such SSDs cannot... 

High-quality online services demand reliable and fast packet delivery at the network layer. However, clear evidence documents the existence of compromised routers in the ISP and enterprise networks, threatening network availability and reliability. A compromised router can stealthily drop, modify, inject, or delay packets in the forwarding path to launch Denial-of-Service, surveillance, man-in-the-middle attacks, etc. So researches tried to create intrusion detection methods to identify adversarial routers and switches. To this end, data-plane fault localization (FL) aims to identify faulty links and is an effective means of achieving high network availability. FL protocols use... 

Gene expression microarrays include thousands of probes spotted on their surface to measure the expression level of a set of genes. Identifying the amount of a transcript level by hybridization, each probe is complementary to a fragment of a specific gene transcripts. Although probes are designed to avoid crosshybridization to non-specific transcripts, occurrences of cross-hybridizations is inevitable due to massive probes that are spotted on microarrays. The main question is whether these non-specific cross-hybridization have significant effect on the downstream analysis of gene expression microarray datasets. This thesis aims at answering to this question by considering datasets from... 

Confining nematic liquid crystal between two curved boundary conditions while the nematic molecules have a degenerate planar anchoring leads to complex and beautiful textures of molecular disparagement(defect) in the bulk and on the surfaces. Such the liquid crystal shells are made with double-emulsion techniques in microfluidic devices have provided applications for micro-scale colloidal linkers.In this work, we have numerically minimized the elastic energy in one-constant approximation in present of Fournier’s degenerate surface potential with finite element method. The nematic shell is confined between two spherical surfaces that we have studied the final energies and their related... 

Secure routing is a major key to service maintenance in wireless ad hoc networks. Ad hoc nature exposes the network to several types of node misbehavior or attacks. Wormhole attack is one of the most severe active attacks to mobile ad hoc networks. Noting the resource limitations in such networks, nodes may have a tendency to behave selfishly. Selfish behavior can have drastic impacts on network performance. We have proposed a Misbehavior-Tolerant Multipath Routing protocol (MTMR) which detects and punishes all types of misbehavior such as selfish behavior, wormhole, sinkhole and grey-hole attacks. The protocol utilizes a proactive approach to enforce cooperation. In addition, it uses a... 

Providing high bandwidth network infrastructures for ever increasing need of data transport is of great importance. The underling infrastructure for many communication services such as GSM/3G/4G mobile networks and Internet services is Synchronous Digital Hierarchy (SDH) optical transport systems. SDH are standardized protocols that multiplex multiple lower rate digital bit streams, such as E1 and Ethernet, and transfer them synchronously over optical fiber using lasers or LEDs. In addition to high data transfer rates, flexible network management and protection mechanisms have great importance, hence are part of SDH standards. In order to obtain flexible network architecture and protected... 

Development of Smart Grid and deployment of smart meters in large scale has raised a lot of concerns regarding customers’ privacy. Consequently, several schemes have been proposed to overcome the above mentioned issue. These schemes mainly rely on data aggregation as a method of protecting users’ privacy from the grid operators. However, the main problem with most of these schemes is the fact that they require a large amount of processing power at the meter side. This, together with the fact that smart meters don’t usually have a powerful processor, can cause the unavailability of smart meter data at the required time for operators of the grid, and at the same time disables smart meters from... 

A liquid crystal is a state of matter composed of highly anisotropic building blocks. When liquid crystals are exposed to surfaces with given shapes and anchoring conditions, the orientation of their molecules gets spatially disordered and topological defects may form in the system. The interplay between liquid crystals and the geometry and topology of the colloidal particles has motivated extensive recent studies.In this thesis, we present the numerical modeling results for two faceted colloidal particles in a thermotropic nematic liquid crystal. To obtain the equilibrium nematic field with a finiteelement method, we numerically minimize the free energy of the system that based on the...