Sharif Digital Repository

Natural gas contains small amount of benzene, toluene, ethyl benzene and meta-xylene (BTEX). These compounds are soluble in amine solutions and accumulate in aqueous amine solution during sour gas removal process. They produce problems such as foaming in amine adsorption columns. The aim of this work is to study BTEX removal from aqueous amine solution by means of activated carbon. Three different commercially available granular activated carbons were used in experiments. Experiments were divided in static and dynamic adsorption categories. In the static tests, equilibrium adsorption of all three activated carbons were performed and the most effective activated carbon sample determined by... 

In general, release of hazardous gas in chemical process plants could be due to two reasons. First is failures due to degradation of components that have inventory of hazardous gas in standard process conditions, and the second is deviation of system from standard process conditions because of different failure modes of related components, e.g. controller equipments. The purpose of this study is, calculating the probability of H2S releasing in GS(03) plant of Arak Heavy Water factory, using PSA methods and its risk assessment. At First, fifteen groups of initiating events were identified with Hazop study for desired system. Then, for calculating the frequency of each event, the combination... 

Information Technology Strategic Planning (ITSP) is performing strategic planning in Information Technology in alignment with overall goals' of organizations. An ITSP framework is consisted of stages, instructions, and models that should be used during an ITSP project. In this research an appropriate framework for public universities which are under supervision of Ministry of Science, Research and Technology of Iran, is proposed –and not selected nor presented. Process, models, methodology and altogether framework of ITSP projects (in case of out-sourcing or doing in-house), have a vital role in the success of project. Therfore, Iranian public universities and also other educational and... 

When the human body is subjected to high accelerations, cardiac function and blood supply to the body can be changed. Due to the complex geometrical and mechanical properties of heart, finite element method is useful way for analysis of response of this structure under different load types. Modeling heart using finite element method requires mechanical and geometrical properties of heart. Soft tissues modeling, such as heart muscle using finite element method is one of the most challenging issues in field of biomechanics. In this thesis, the mechanical properties of heart are obtained by performing experimental compression tests on samples of fresh bovine heart. Using obtained experimental... 

There has been a lively debate between two major strategist groups in innovation strategy literature. The first, with Ansoff being the protagonist, pose a rational approach in describing a corporate innovation strategy formulation process while the other group, with Mintzburg as the protagonist, prescribe an incremental approach.It seems that in continuous change and uncertainty, rational approach can weakly predict the reality and one can claim that in such situations incremental approach is more effective than rational approach. Based on the review of literature and consequent classification, most of the strategies that are named as innovation strategies in literature use rational... 

Nowadays, Microelectromechanical accelerometers are of the main parts of inertial navigation systems, and so it is essential to characterize and understand the parameters affecting their performance in order to design them in a way that enables them to survive different practical applications. Mechanical shock is one of the factors existing in almost every industrial environment and cause damages or even permanent failures in MEMS devices. Identifying these damages and protecting the microstructure against them seems inevitable for the designer and engineer of this field.
In general, approaches of protecting microstructures against mechanical shock are categorized into two major... 

New developments have led to the creation of functionally graded materials which their unique property is continous changing in material properties. The increasing use of these materials has caused a lot of research on various issues related to them. One of the applications is applying these materials in spherical structures and open and closed rings. In mechanical equipment spherical structures and rings are used in various ways. The spherical structures of small parts, such as bearings to large structures such as spherical tanks are used. Due to the rapid growth of technology in the construction of structures of functionally graded materials, analysis of these structures in different... 

Energy constraint is the most critical problem in wireless sensor networks (WSNs). To address this issue, clustering has been introduced as an efficient way for data aggregation and routing. However, there also exist some disadvantages associated with the clustering scheme, such as additional overheads during the cluster-head election and cluster formation process. Most available clustering algorithms do not efficiently take into consideration the geographical information of nodes in the cluster-head election. This leads to uneven distribution of cluster-heads and unbalanced cluster sizes, which brings about uneven energy dissipation in clusters. In this research, an Efficient Distributed... 

Grasping and manipulation of biological cells have an extensive applications in genetics ,cell proliferation ,cell injection and etc. In robotic manipulation ,it is often assumed that the objects being handled are rigid and only small deformations occurred during manipulation. this does not apply for the case of biological cells. biological cells are highly deformable structures, and their material properties are not well quantified. Therefore strategies for characterizing and manipulating of such deformable objects needs to develop. Different experimental techniques have recently been used and devised to study biological cells. On the one hand, although this experimental techniques have... 

Medical images contain information about vital organic tissues inside of the human body and are widely used for diagnoses of diseases or for surgical purposes. Image Reconstruction is essential for medical imaging for medical systems like suppression of noise or de-blurring from projections in order to have images with better quality and contrast. Due to the vital role of image reconstruction in medical sciences the corresponding algorithms with better efficiency and higher speed is preferable. Most algorithms in the field of image reconstruction are operated in frequency domain such as the filtered back projection which is a popular algorithm for the reconstruction of the medical images. In... 

Optical Tweezers (OT) are non-invasive micro-manipulation tools based on a tightly focused Gaussian laser beam for applying and measuring pico-Newton range optical forces. They are also utilized for trapping and moving particles and biological specimens. The force exerted by OT is mainly determined by detecting the position of the trapped object inside the harmonic potential well of OT. Conventionally,a Quadrant Photo-Diode (QPD) positioned at the Back Focal Plane (BFP) of the condenser lens provides the position of the bead with MHz temporal and nanometer spatial resolution. As a disadvantage of this detection scheme, it is impossible to obtain simultaneously the maximal lateral and axial... 

With increasing population and lack of habitable spaces, the building heights increased in cities around the world. Placing components of a structure in tandem may cause a permanent failure of the members due to strength reduction. During recent years, this kind of failure occurred in different places of the world, and is called progressive collapse. There are some various samples of the progressive collapse which all are good samples of failures such as building failure in Ronan Point in the UK, Twin Towers or the world trade center in NY, and Pentagon building. According to these issues, different institutions codified guidelines and codes in this field such as Department of Defense as DoD... 

In recent years, hardware Trojans (HTs) have become one of the main challenging concerns within the chain of manufacturing digital integrated circuit chips. Because of their diversity in chips, HTs are difficult to detect and locate. This thesis attempted to propose a new improved method for detection and localization of HTs based on the real-time logical values of nodes. The algorithm extracts the nodes with special attributes. At the next stage, the nodes with the greatest similarity in terms of logical value are selected as targets. Depending on the size of the circuit, the extraction continues until a sufficient number of similar nodes has been selected. The logical relationship between... 

The energy consumed by lighting, heating, ventilating, and air conditioning (LHVAC) systems have been increasing over the last decades. Thus, improving the efficiency of LHVAC systems has gained the attention of industry and academia. This concern has posed challenges for controlling and optimizing LHVAC systems. The traditional methods, such as on/off and PID approaches, usually involve conditions and parameters that may not hold in practice since LHVAC systems are complex, nonlinear, and dynamic. Also, controllers are one of the important components of a method for its efficiency. This research focuses on controlling LHVAC systems. Fuzzy logic controllers one of the best controller for... 

In drilling oil well with respect to depth of several thousand meters, knowing the physical conditions of down-hole well such as temperature, pressure and stress have particular importance in prevention of possible injuries such as breaking the drill bit or increasing temperature. If these data can transfer from down-hole to bore-hole of the well, the operators can prevent from critical conditions such as intertangle of the drill-string. Currently, because of this lack of information, there are irreparable damages in oil industry annually. Based on researches, because of down-hole conditions of the well, these data can’t transfer with electromagnetic telemetry. Currently one of the data... 

Drilling in oil industry, is an expensive process in produce and extract oil from well. Any mistake in drilling may cause many drawbacks for industry owners. Phisic’s quantities information at downhole like tempreture, pressure and force on bit synchronously can inform user from torrid conditions and prevent undesired events by actions like evoke bit from downhole or change at rotation velocity in drilling and finally stop operations. With attention to a lot of problems in data transport from long distance more than one kilometer from downhole, scientists believe that one of the methods to do this process is converting data gathered at the bottom hole to acoustic waves and transmit them to... 

Steam-Assisted Gravity Drainage (SAGD) is one of the best and the most effective methods of enhanced oil recovery (EOR) which is used in the production from Heavy Oil Reservoirs which constitute large amount of oil throughout the globe. In a typical process of SAGD, steam is injected into a horizontal well and the oil is produced several meters deeper in the ground. In order to increase the Recovery of this process, it is better to review on the Pre-heating methods around the injecting and producing wells. Pre-heating is important when the viscosity of the oil is large enough to prevent oil from any motion at the beginning of the SADG operation, and makes it necessary to to use a Pre-heating... 

Today, with the spread of various videos especially sports video and availability of them, the need for automated methods for search and retrieval of concepts from videos is strongly felt. On the other hand, summarizing video in order to making significant parts of them available is very important. One of the broadest scope that researchers have provided methods for extracting semantic concepts, is soccer videos. Often to extract high-level events, we need a definition and use of intermediate concepts. In this thesis "replay", "audio highlights" and "view type" are used to extract important events in the game. Here, two new methods are introduced for replay detection and view type...