Sharif Digital Repository

Due to the increasing relationships, and expand the transportation of goods and fuel by ships and other factors may also cause the release of pollution into the sea, Oil and also its derivatives are the dangerous pollutants that threaten the health of the environment and may destroy the local ecosystem.One of its highly carcinogenic pollutants that even inhaled,is furfural. A new and efficient method for the filtration of toxic substances and hazardous wastewaters, using the moving bed biofilm reactor treatment that is MBBR system. Microorganisms present in the reactor, that was used in this project, from the microorganisms of industrial Behran Company. Removal of furfural from the harsh... 

Long Term Evolution (LTE), is a standard for wireless communication of high-speed data for mobile phones and data terminals. Increasing the capacity, improved support for mobility and simplified architecture are a number of its goals. As many other standardas LTE uses Multiple Input-Multiple Output (MIMO), which is a system that uses multple antennas in the transmitter and the reciver. LTE has adopted single carrieer-frequency division multiple access (SC-FDMA) for the uplink multiple access scheme in order to decrease peak to average power ratio (PAPR). In SC-FDMA a discrete Fourier transform (DFT) is performed on the signlas before going through the OFDMA modulation.
A novel... 

Heavy metals, present in many industrial wastewaters, are considered as major pollutants of environment. Various methods to removal heavy metals effectively from effluents have been used in industry, yet more efficient and economical methods are required. Magnetic iron nanoparticles are known for their superior adsorption, ion exchange and electro-static forces characteristics.The aim of this study was to evaluate the efficiency of magnetic nanoparticles for removal of hexavalent chromium (VI) and Divalent nickel from wastewater and the parameters that influence the removal.The magnetite nanoparticles were prepared by co-precipitation method where produced Fe3O4 nanoparticle’s average size... 

In this project, the feasibility of hydrocarbon waste water treatment with low concentration by physical- chemical treatment methods will be discussed. The purpose of this thesis is to investigate the feasibility of reusing the water outlet of the oil and gas refineries, in the region of ASALUYEH where there is an urgent need for water. By using activated carbon and wooden absorbent (absorption method) efficiency of this method was determined. Both coagulation and flocculation methods were investigated. To design and optimize various operating conditions on the adsorption process the RSM method was used. Temperature, residence time, feed concentration, amount of adsorbent, and adsorbent ... 

Network structures have many applications in everyday life. For example, we can refer to the real world systems in which clients are indicated by nodes and edges represent their connectivity. Network science has witnessed tremendous progress over the last decade. The field of Network Science and Engineering started by exploring properties of real-world network systems and constructing proper models. Previous studies shows that all real world systems share some common structural features, such as scale free degree distribution and group structure. Analyzing interaction between network structure and its dynamic is a one of the main problem in studying complex dynamical networks. In this study,... 

Growing rate of eutrophication in receiving waters has made the enhancement of wastewater treatment plants to advanced methods of nutrients removal as necessary. Nitrogen and Phosphorus as the nutrients can reduce the quality of water and even make it unusable. Phosphorus is known to be one of the main reasons of eutrophication and creation of algal bloom. In this study, chemical-biological method for phosphate removal from the municipal wastewater is studied. Experiments are implemented for hydraulic retention times of 4, 8 and 16 hours, total intake concentration of phosphorus 7 ppm, COD 400 ppm and Nitrogen 25 ppm. Ferric Chloride as the precipitator chemical substance injected into the... 

The commodity market as a noteworthy section of the capital market plays a prominent role in the economy of a nation. Base metals, which are widely utilized as industrial raw materials, account for a part of the costs imposed on a nation’s economy. Hence the price levels and volatility of such metals have been under close observation by the capital markets and in the process of monetary policy. In this research we investigate the impacts of the monetary policy of the Federal Reserve on the return of base metals based on daily data and also on the stock return of the corporates which are associated with these metals by using intraday data. This poster employs Federal Funds Futures Contracts... 

There are a lot of industry, including refineries with saline wastewater. Biological wastewater treatment saline pose particular problems and leads to plasmolysis microorganisms in the presence of salt. Remove salt from the wastewater before biological treatment by reverse osmosis or ion exchange and other methods are expensive and often impossible. Remove nutrients from wastewater before disposal and give up their saline for nature is essential. Because the these materials, especially nitrogen and phosphorus can degrade water quality and even make it unusable. So that by increasing the concentration of the algae production is also too much and cause eutrophication of water tanks are grown.... 

Bridges are among the crucial elements of transportation networks, and play an important role in facilitating emergency relief efforts following earthquakes. For this reason, it is emparative to monitor their damages to ensure about their performace in earthquakes. The structure of a bridge is divided into two parts, namely the superstructure and substructure. Due to the relatively high rigidity and strength of superstructures, most of structural damage is usually concentrated in substructures, which may ultimately affect the overall stability of the bridge. Therefore, assessing the level of damage in the substructure is of utmost concern. This research attempts to evaluate the damage in the... 

The use of multiple sensors that produce different physical parameters of the measured system for its health monitoring raises the reliability of the diagnosis. At the moment, the fault detection capacities of ball bearings by means of proximity probe are detected by exploiting the advantages and reducing its defects by appropriate signal processing of the raw data in the time domain. Also, the application of numerical derivation and integration to achieve to the desired frequency spectrum in defect detection is investigated. A set of experiments with different sizes of internal ring, outer ring and ball defects, four levels of speed and two load levels have been performed. Data acquisition... 

Effective field theory is a practical method for model building and explaining experimental/observational data. These theories are constructed based on knowing low energy degrees of freedom and symmetries (accidental or fundamental). By construction, these theories are applicable up to a cut-off scale and their predictions beyond that are not reliable. For applications to higher energies a UV completion is needed through which modifications are applied or new heavy degrees of freedom are introduced. In order to complete a theory in a Wilsonian approach, scattering amplitudes must satisfy some constraints. These constraints are derived from basic assumptions like Lorentz invariance,... 

Electricity is one of the most important kinds of energy and also one of essential needs of humans for maintaining their life. Due to growth of costumer’s load and In order for delivering high reliable power to the consumers, the structure of the power grid must be expanded and/or demand side management policies like demand response programs must be taken into consideration. One of the most important and less-focused aspects of power grid expansion planning is, distribution system expansion planning. Distribution system expansion planning (DSEP) is an important task of electric distribution companies and operators in order to appropriately supply their customers load with the minimum cost... 

Price to earnings ratio is one of the most used ratios in financial markets for valuation of firms in the Iran and world. In present research for analysis of this ratio,investors’ sentiment alongside fundamental factors affecting price to earnings ratio has been investigated. Fundamental factors affecting this ratio are selected based on prior research and economics theory; these factors are, dividend ratio, growth,risk and inflation. For the analysis of investors’ sentiment, eight proxies related to sentimental behavior have been utilized; among them, four are introduced and used for the first time in this research. Implementing these eight sentimental proxies, a variable measuring... 

Occurrence of scouring around the seabed pipelines can lead to pipe failure and pose a serious threat to the marine environment, economic losses and waste of oil and gas. Therefore, to prevent the occurrence of scouring, by simulating this phenomenon and identifying the parameters affecting it, we can help to design a more efficient placement of pipes in the seabed. Various methods such as potential flow theory and turbulent single-phase and two-phase models have been proposed to simulate this phenomenon. The purpose of this article is to simulate and investigate the effective parameters of this phenomenon by combining computational fluid dynamics and separate elements. The innovation of... 

Suction caisson is a relatively new technology which was introduced about 30 years ago for the first time and after several investigations, was found its position in the oil industry and construction of anchorages, during previous decade. So nowadays, it is the most effective and economical choice as the mooring of offshore structures in comparison with the other foundations. Suction caisson is a hollow cylinder with an open bottom and a closed top. After placement on the seafloor, the caisson first penetrates into the soil by its self weight and then inserts into the ground by pumping water out of it. Although many researchers have attempted to understand the behavior of suction caissons... 

Mass transfer laws and Microorganisms growth relations are the two important factor s in modeling the “anaerobic baffeled reactors ”.
In this peaper , behavior of the anaerobic baffeled reactors studyed with using mass transfer and mass balance equations, differential equations for the unsteady state condition have been produced , then , the best microorganism growth mechanism (Monod & Haldan) has been chosen using microorganism growth equations for anaerobic system and complete model equations for steady state and unsteady state conditions have been presented. Factors and constants of the model equation have been calculated by ... 

Recently complex networks, have been widely used as a model to study the behavior of human brain. By affecting different parts the brain, Neuronal disorders change the structure of functional brain networks. Investigating these changes using different graph theory metrics can be a useful methodology for human brain analysis in health and disease. Alzheimer's disease (AD) is a neural disease causing impairment in different brain activities including memory and cognition.The aim of this study is to construct the functional brain network of 17 AD patients and 17 healthy control subjects at resting state condition and analyzing them using the theory of complex networks in order to achieve a... 

According to different interpretations of the philosophy of science schools, scientific knowledge, is responsible for explanation, description, control and prediction of material phenomena and their relationships. But these facts, besides their real aspects, which can be observed and found by episteme, have a conventional side. The conventional aspect of science is rules and contracts which are obtained from the facts you can find by techne. Although conventionals can be traced back to the division of science into theoretical and practical by Aristotle and other Hellenistic philosophers, but in this century Islamic philosophers especially, Tatbayee paid more attention to this topic. This... 

The modern science of networks helps us to have a better understanding of complex systems. Networked systems can be found everywhere and many systems can be represented by a complex network. A networked structure consists of a number of nodes and links connecting to them. Networks’ ability in information propagation is one of their amazing features that have attracted lots of scholars to work on. It has potential applications in many fields ranging from marketing to biology, epidemiology and sociology. Information propagation studies how information such as computer viruses, contagion, rumor, or new product’s interest propagates over a network. Percolation theory and various epidemic models... 

Modern communication and space systems such as satellite communication devices, radars, SAR and radio astronomy interferometers are realized with large antenna arrays since this kind of radiating systems are able to generate radiation patterns with high directivity and resolution. In such a framework, conventional arrays with uniform inter-element spacing could be not satisfactory in terms of costs and dimensions. An interesting alternative is to reduce the array elements obtaining the so called ‘ thinned arrays’. Large thinned arrays have been exploited because of their advantages in terms of weight,consumption, hardware complexity, and cost over the...