Sharif Digital Repository

By using the information and communication technology (ICT) in the past three decades, many industries have been able to improve their productivity to a great extent. However, the construction industry is not experiencing such growth in productivity. Many believe that one of the most important reasons for this problem is the ineffectual use of ICT in the construction industry. To solve this problem, several construction methods have been developed in order to increase the productivity of the construction industry by using the aspects of the ICT. One of the most promising methods in this area is the Virtual Design and Construction (VDC) method.
Virtual Design and Construction (VDC) is the... 

Although Pulsed Plasma Thruster (PPT) has first been utilized in a space mission in 1964 but after more than four decades, it is still a space rated technology which has performed various propulsion tasks from stationkeeping tasks to three-axis attitude control for a variety of former missions. With respect to the rapid growth in the small satellite community and the growing interest for smaller satellites in recent years, PPT is one of the promising electric propulsion devices for small satellites (e.g. CubeSats) as the following advantages: simplicity, lightweight, robustness, low power consumptions, low production costs and small dimensions. In spite of the fact that the issues relating... 

The importance of creating a fluid flow with accurate and controllable flow in many industries is undeniable. There are several ways to create this type of flow, and a variety of pumps can be used to create such a flow. The presence of noise, limitations in reducing the flow rate (sometimes in some pumps the flow rate can not be reduced to a minimum), depreciation costs and many other limitations, reduce the attractiveness of using conventional pumps in some applications. The subject of this project is the design and construction of piezoelectric based micro-pumps to solve the above problems. In many applications, the need for fluid flow with very low flow and high quality and accuracy is... 

In this research a robotic fish was designed and fabricated. For this propose different types of manufactured robotic fish were investigated and this model was developed and made with a one-piece flexible tail with an actuator that creates lateral movement through cable strings attached to the tail. Proposed mechanism has a simple, low cost structure that facilitates the control of the robotic fish movement. To control this robotic fish, a four-channel radio controller with 40 kHz frequency, was used. Swimming mode of this robotic fish is categorized in Subcarangiform swimming mode which is faster and has better maneuverability compared to its counterparts. It should be noted that the... 

No-one likes being confined to a hospital bed. Children particularly can feel lonely, bored or frightened in these conditions. Hours feel like days, and they may not be able to fully comprehend why they are there. Among kids hospitalized because of distinct diseases, children with cancer have incomparable status and needs. They experience physical and mental problems caused by cancer and medications. Cancer treatment may cause distress which can lessen the effectiveness of the treatment. Utilizing social robots to interact with children in clinical environments has been verified to both diminish their distress level and enhance the effectiveness of the treatment process. To improve the... 

Rotating detonation engines are capable of reaching a higher efficiency in comparison with ordinary engines, due to utilizing pressure gained combustion wave. In this study, the feasibility of a laboratory sample RDE with an annular geometry of diameter of 76 mm has been studied and then designed and constructed. In this sample, hydrogen and standard air were separately injected into the combustion chamber of detonation. The injection of fuel flow and air flow are axial and radial, respectively. The designed geometry is flexible in terms of changing the injection geometry and detonation channel wide, which provided the possibility of testing for a variety of injection and detonation... 

Engineering, Procurement and Construction (EPC) contracts commonly used in the construction of oil and gas production facilities in Iran. These projects are subjected to many uncertainties. Because in these projects contractor is responsible for most of the activities related to the Engineering, Construction and Procurement, EPC contractors often assume most of project risks. Therefore, project risk management is very essential for achieving project goals. Several studies have focused on the identification and analysis of EPC project risks. However, they fail to identify appropriate risk management strategies. The objective of this study is to identify fair and efficient risk allocation and... 

In this research, the mechanical section of a reduced-scale hybrid vehicle simulator was designed and fabricated. In order to scale down the vehicle dynamics, a method based on dimensional analysis was proposed. An internal combustion engine and an electric motor were selected as power sources and then, scaling was performed, according to the specifications of the combustion engine. Afterwards, the power transmission system was designed first in concept and then in more detail. Finally, the design was manufactured and assembled. The study was made in conjunction with another study responsible for the controlling section of the work, conducted by Safabakhsh The sponsor of these two researches... 

Experimental investigation of drillstring dynamics is essential to complete the theoretical studies and to alleviate complexity of such dynamic models. Vibration is one of the most effective parameter affecting drilling operation. Most of the experimental setups are looking for drilling mud tests, operational characteristics of bit under several bad condition and bit mud stone interaction in drilling operation and there are few setups to study vibration of the drilling setups. In this project a test rig has been introduce which is a scale of a real industrial drilling rig by the factor of 10300. Then based on the field studies of drilling failures in Iranian oil drilling rig , a crack has... 

The main goal of this work is to estimate the linear transfer function of a single-blade VTOL aerial vehicle, the so-called Monocopter.At first, a prototype of this vehicle is designed and built based on the previously gathered information. The complexity and high manufacturing cost of the first prototype has forced us to build one other simple and cost-effective vehicle. A complete electronic board for data-logging has also designed and built. Many flight test has been carried out and recorded output data are processed by CIFER and MATLAB software in order to identify the dynamic model of the vehicle. The results are presented in different forms  

Implementation and development of large infrastructure projects are considered as the most important tools for governments to achieve sustainable development. Need of enormous finance, high level of technology and massive workload are the main feature of these projects. These projects cause significant effects on economic, technological and even political and social status in nations. So the appropriate project delivery method selection is very important for the preparation and implementation of this kind of projects. Also, mistake in this field will bring irreversible costs and losses.
Thus, the appropriate policy in decision making process about the project delivery method... 

Increasing fossil fuel consumption has led to serious problems in energy supply and environmental issues such as global warming, air pollution, ozone depletion, and security issues. A strategy to improve energy consumption requires recycling wasted energy and preventing it from being released into the environment. A wide range of available heat sources such as heat dissipation in the transportation industry, solar heat, biomass and geothermal have low-temperature, which contain large amounts of energy but they do not have enough temperature to make them economically viable and cost-effective. Several applied technologies have been proposed to utilize these resources, among which the organic... 

Today, the cleaning and moss removal of the hulls of ships is very important due to the strict and international laws of reducing pollutants and the exorbitant cost of fuel of the country's navy. The advantages of cleaning the hull of vessels are reduced fuel consumption, increased ship speed and longer hull life. Traditionally, the hulls are cleaned by divers, and in recent years the use of crawling robots has been welcomed by the industry because of its benefits. This important thing in Iran is still done by divers and therefore the need for indigenous development of such robots in the country is felt.In the present study, the aim is to design and build a reliance system for the ship's... 

Warming the injectable blood is a set of methods used to transfuse blood to the supplier (Accident patients, surgery, dialysis). These methods raise the temperature of the injected blood to body temperature. Blood transfusions are performed directly before World War II, so there is no need to heat the blood, Increased need for blood units caused blood banks. In these banks, to prevent the proliferation of pathogens, the temperature of blood units is reduced to 2-6 degrees Celsius. For indirect injection of these blood units, the injection temperature should be brought to the patient's body temperature before injection to prevent the recipient's body temperature from decreasing.In this... 

Being harmless to living tissues makes magnetic robots very promising for medical applications. Furthermore, since these robots are driven by external magnetic fields, no actuators are needed to be placed on the robots, enabling them to come in very small dimensions if necessary. Motion control of small magnetic particles paves the way for future applications, such as deliberate drug-delivery, sampling, and lowinvasive surgeries.The goal of this research is to design and construct a platform for generating desired magnetic fields in order to control the motion of magnetic robots in threedimensional space. In order to do so, a system of eight electromagnetic coils with iron cores was built.... 

Hand-launched UAVs are type of unmanned aerial vehicles that due to transportability and geometric specification, are operationally valuable and worthy. reconnaissance & surveillance (aerial mapping, aerial filming, inspection, border protection); health care (blood transport, body organ transport, medicine delivery); agriculture (farm monitoring, fertilization, cloud seeding); payload delivery (envelopes posting); network covering (internet supply, telecommunication relay); crisis management (remote area medical) are some of typical applications and missions of this type of aircrafts. These UAVs have almost low altitude short endurance (below 5000 ft. and less than 2 hrs.). To extend their...