Sharif Digital Repository

Limited fossil energy resources and problems with greenhouse gas emissions, has increasingly focused attentions on renewable energy as a solution to this issue. Marine energy due to the the vast amount of wind, current and wave available resources, can play a major role in providing renewable energy and reducing CO2 emissions. However, using one renewable energy, in some cases due to its high volatility and high costs is impractical. Combining different marine renewable energies, can be mentioned as a solution to increase competitiveness with fossil fuels. The aim of the current research, is to introduce a method to select the best location in terms of renewable energy farms wind, current... 

Oil spills in marine environments lead to serious environmental disasters and have significant short-term and long-term effects on the aquatic life cycle, the health of people living on the coasts, the region's ecology, and social and economic activities. Shipping and marine transportation are responsible for many oil accidents. For this reason, harbors- as one of the most important marine transportation infrastructures- are always exposed to oil spills which in addition to economic losses, can lead to disruption of ports' performance.To reduce the environmental and economic damages caused by oil spill incidents, it is necessary to prepare the harbors to deal with and clean up oil pollution... 

Most marine areas such as bays and lagoons are usually exposed to the high pollution load of their catchment area. Gorgan Bay and Miankaleh Wetland is a connected water body that is subject to the entry of various pollutants through the surrounding agricultural and urban areas, due to the ecological importance of this area and its registration as a biosphere reserve in the United Nations. It is important to control and evaluate its water quality. TSI and NSF-WQI environmental indicators have been used to evaluate the level of water pollution and water quality respectively. TSI and NSF-WQI indices have been evaluated in 8 stations in January and September 2023. The parameters of total... 

Gas and oil reservoirs on Caspian Sea made Engineers to choose suitable riser for conveying oil and gas. Steel catenary riser is one of the best choices for deep and ultra-deep water. Although these kinds of risers show very good resistance on buckling but cyclic loads made them to fail by fatigue damage. Two sensitive points regarding to fatigue damage are Hang off point and touch down point. Fatigue damage on TDP is related to soil properties. Because of the cyclic movement of the riser a trench would shape on seabed. In this research, based on Finite element analysis, the effect of trench on fatigue life of SCR would be analyzed  

This study investigates the ovality on the burst pressure of the pipe inside the well. In the last decade, the use of natural offshore oil and gas resources has increased, and as a result, the importance of well integration as a major part of offshore platforms is clear. At the same time, accidents at oil and gas wells have economic and environmental consequences that underscore the importance of ensuring safe operation. Integrity management of fluid pressure wells has been developed to ensure the safe operation of wells. The functional area of integrity management begins with planning, then inspects and then evaluates, and eventually leads to corrective action, and this loop is repeated on... 

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... 

Paper and cardboard waste pulping consume large volumes of water, so the discharge of this effluent without proper treatment can have far-reaching environmental consequences. The color and variable COD concentration of wastewater in this industry make treating this wastewater complicated. Therefore, this study aims to reduce the COD of the wastewater treatment plant of a pulp and paper mill under different laboratory conditions to achieve environmental standards in Iran.In this study, coagulation-flocculation and the Fenton process on the wastewater entering the treatment plant were investigated first. It was found that coagulation and flocculation by 750-1250 ppm of alum coagulant and ten... 

In this study, a framework for reliability analysis of offshore wind turbine structures has been presented. The rapid development of these structures in the world due to the increasing need for electrical energy and limited sources of fossil fuels has increased the importance of research on the behavior and condition of these structures. For Iran, despite its fossil fuels resources due to its international voluntary commitments to reduce greenhouse gases such as Paris agreement, the use of renewable energy such as offshore wind energy is important. Also, the offshore wind turbine structure is affected by different forces and environmental conditions in its life cycle, which are associated... 

The purpose of this study is to numerically investigate the Vortex-Induced Vibration (VIV) around the cylinder, which occurs in many engineering structures, including offshore structures, offshore risers, deep-sea pipelines, bridges, cables, and tall buildings. This phenomenon is non-linear and self-limitting and is the major cause of fatigue and failure in engineering structures. At the same time, it is possible to harvest Aquatic Clean Energy from Vortex-Induced Vibration. This research investigates the single degree of freedom and two degrees of freedom oscillator. The numerical model is validated using an experimental model in the Sharif University of Technology's advanced hydraulics... 

Knowing the location and time of oil accidents and trying to track the pollution caused by these accidents is very important for the purpose of monitoring and protecting the environment. The occurrence of large oil spills in the marine environment can have serious environmental, social and economic consequences. In this research, oil spills in the Persian Gulf were first identified using remote sensing method and Sentinel-1 satellite images. The images of this satellite were called for the processes needed to identify oil spills in Google Earth Engine space. After detecting the oil spills, it is necessary to determine the duplicate spills and remove these types of spills, as well as estimate... 

Gorgan Bay, registered as a biosphere reserve, has environmental value in the country and the world. The bay is separated from the Caspian Sea by sedimentation in the sandy spit of Miankaleh. Due to the declining water level of the Caspian Sea and the possibility of hydraulic connection disruption and closure of its openings, this water body may face many problems in the future. Main problems are the increase in water retention time and, consequently, the decrease in water quality and the problem of local access during the seasons when the water level drops. In this study, engineering solutions have been studied in proportional with the current conditions of the Gorgan Gulf, which include... 

This dissertation documents the study of Omni-max anchor, and the development of a computational procedure and its application to the analysis of OMNI-MAX anchor behavior under mooring loads. An OMNI-MAX anchor is an offshore anchor designed and developed in recent years, to overcome the uncertainty in the capacity of ordinary offshore anchors.In the process of this research to understand the capacity and mechanisms in which the anchor carries applied loads, the contribution of different parts of the anchor to the total capacity of the anchor is estimated using classical soil mechanics. Then, due to the failure of the used approach to model the dynamic behavior of the anchor and to better... 

Hazardous Noxious Substances (HNS) are chemicals. Due to population increase and as a result, increased demand, HNS transportation by sea has been raised. Gasoline and diesel are two kinds of HNS which have the largest transported amount via northern ports of Iran especially Anzali port. So, HNS spill from tankers is an imminent event and threat for environment of Caspian Sea. Organizations that are concern about the health of coasts and seas water always try to use the softwares to simulate the currents and waves to define the hydrocarbon slick transport. Therfore in this study, a 2D hydrodynamic/oil spill model has been developed to predict the transportation of diesel and gasoline slick... 

Different causes in the exploration, production and transport of oil in the marine environment result in oil spill events. Since elimination of the probability of occurrence of spills is not possible, it is important to have a plan to control the risk of oil spills by optimal response. In this research, a general stucture is presented for the DSS required for oil spill response planning. This system can be used for evaluation of the effectiveness of response drills, and risk-based ranking of receptor areas and spill sources. Ranking based on risk is realized through probabilistic or stochastic risk assessment. The applicability of the proposed system is examined in differnet case studies in... 

Energy production from fossil fuels such as oil and gas is one of the non-renewable energies, which causes many environmental problems such as global warming and environmental pollution. The existence of these problems has led to agreements such as the Glasgow Environmental Agreement, which obligates governments to apply methods to reduce the production of greenhouse gases, which include reducing the consumption of fossil fuels and increasing the use of renewable energy. Sea wave energy is one of the renewable energies that can be used to generate electricity. In the seas of Iran, including the Caspian Sea, Persian Gulf and Oman, there are sources of wave energy that can be used and are... 

The development of industries in a region without considering the atmospheric environmantal capacity, can lead to an environmental disaster. This research has investigated the air pollution and emission of standard pollutant sulfur dioxide under different scenarios of the development of gas refineries in the Mokran coast. In order to achieve this goal, by having information of pollutant sources and sulfur dioxide emission rates from each of them, modeling was done by inputting temperature data, cloud coverage percentage, wind direction and wind speed, and the output data including pollutant emission rates in the regions. The selected places to investigate the results include: Ramin,... 

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... 

One of the natural functions of wetlands is to neutralize the dangers caused by floods. Therefore, if a facility is built in the area of wetlands, it should not disturb their natural functioning. During the Iran-Iraq war, several antenna roads were built across the wetland, and the construction of these roads divided the wetland into 5 separate reservoirs. After the end of the war and with the development of the oil fields west of Karun (Hor al-Azim region), the extraction of oil from this region was put on the agenda. With the flood of April 2018, these facilities and roads were exposed to damage and flooding, and oil production from these reservoirs was stopped. In this research, after... 

Gorgan Bay and Miankaleh Wetland are considered as one of the biosphere reserves and among the areas of international importance in the Ramsar Convention, thus they have great importance. These two inseparable zones are located in the southeast of the Caspian Sea and are connected to the Caspian Sea through Chapaghli Canal and Ashuradeh Canal. The health and water quality of this area has undergone many changes over the years, and the re-reduction of its water level has caused concern among environmental activists. Since Miankaleh wetland is a shallow and semi-enclosed water area that is connected to the Caspian Sea through two narrow canals, pollutants that enter it from land will have a... 

Purpose of this research is an investigation on the effect of soil behavior on fatigue life of steel catenary risers in touch down zone. Steel catenary risers are a part of pipeline installed between the seabed and the offshore platform on the sea level, and its application is to transfer the gas or oil from the seabed to the sea level. Steel catenary risers for their resilience against buckling, easy installation, lower cost comparing other conductors are preferred to other means of conducting oil in recent years. The most challenging issue in the design of this kind of riser is the fatigue problem. The characteristic of the wave loadings we are facing in this environment is cyclic;...