Sharif Digital Repository

The application of membranes for separate of particles in mainly microbial flacs , are fast growing in biological treatment systems. Membrane bioreactors are now considered as one of the major new processes in wastewater treatment. However , membranes are expensive and costly. This study is carried out to test an innovative , locally made filters for separation of flocs in an MBBR reactor. This innovative filter is replacing a traditional settling tank. This type of filters is made very cheaply and has important advantages in installing and operation. Experiments were carried out in a laboratory scale MBBR unit. A filter unit consisting of 3 innovative filter tubes were placed and the... 

In this thesis, the optimal trajectories of a spacecraft in the binary asteroids system is studied. The objective functions of optimal trajectories in these system are the maximum coverage of the asteroids surface and minimum time and fuel consumption. For this purpose, the dynamic of binary system is modeled. The binary system of 1999 KW4 is selected as a case study. The ellipsoid-sphere model is a good approximation for the case of this study. In this model, the asteroids orbit in a circular orbit around each other in a spin-spin-orbit resonance configuration, in which the asteroids’ rotational velocity is equal to orbital mean motion. Then, the equations of motion of the spacecraft as the... 

Friction drilling or flow drilling is a method of making holes in metal sheets, in which the material is pushed with the aid of heat from friction. This procedure allows making holes in sheet metal, with a sleeve formed as the hole is created. This sleeve is then threaded and used as the nut, thus eliminating the need for access to the interior faces of hollow steel sections. On the other hand, with the development of advanced manufacturing techniques, larger and thicker hollow structural sections are becoming more popular in mid-rise and multistory structures. onsequently, flow drilling can be considered as a viable alternative for traditional drilling techniques, where the material is... 

One of the most important methods for recycling of spent Li-ion batteries is acid leaching that various parameters affect it. In this work, influences of effective parameters on the percent of cobalt and lithium recovery with application of design of experiments (response surface methodology-central composite) were investigated and then cobalt nano oxide as the by-product synthesized by pulsing lectrolysis. In the first Phase, effects of parameters such as sulfuric acid oncentration: 2-6 molar, hydrogen peroxide volume percent: 5-10%, S/L ratio: 20-50 g/L and temperature: 50-80°C on cobalt and lithium recovery were investigated and finally an adequate model presented. For all experiments,... 

“Sustainable development” is a frequently used phrase, but the idiom has been experienced little since it was coined by the Brundtland, due to its intrinsic complications. The issue is going to compromise two key components; economy and ecology. One of the solutions based on concept of sustainable development that has been proposed for maintaining water quality at acceptable levels is to cap pollutant emissions at a sustainable level, then establish an economic market in which the right to discharge pollutants is traded according to market supply and demand mechanisms. Water quality trading or pollution trading is one such kind of market-based program that has also been described using names... 

One of the main challenges of Water Resources Planning and Management (WRPM) is to balance water allocation between different uses. Usually, due to political and economic power of other uses, ecosystem receives less attention. Environmental flow is the allocated flow to ecosystem. Ecosystem provides a wide range of services to humanity. Therefore, environmental flow is not exclusively a matter of sustaining ecosystem but also a matter of providing humans with better life. Several methods have been developed to determine the environmental flow but only a few consider its socio-economic aspects. Consideration of these aspects could assist decision-makers with determining the optimum flow and... 

Sustainable agricultural development in the country without regard to water supply problems in terms of time and place is not possible. Construction of water storage tanks filled with water and seasonal use in dry seasons in the effective action in the optimal use of water in the climate of (low and irregular rainfall) is. The most important step in the construction of water storage tanks to choose the best point for the construction of the reservoir basin in order to reduce costs and increase efficiency. Chndmyarh different methods to decide the best option for finding a few options from there. Among these methods can be Tapsys two methods (TOPSIS) and hierarchical analysis (AHP) pointed... 

Nowadays, applications of the synthetic materials are developing in civil engineering projects and widely used in these projects. Therefore, during previous years; use of the Geotextiles as one of the Geosynthetic materials in order to filtration, drainage, separation, soil protection, etc have developed ever-increasing. The goal of this research is modeling and studies of the Geotextiles application in the downstream filter zone of embankment dams in combination with granular materials using FLAC2D software. Gordeh Bin embankment dam situated in West Azerbaijan province has been chosen as case study. In this matter, different models have been made with changes in thickness of the inclined... 

Groundwater quality protection has a significant importance due to abundant applications of these resources in various fields such as agriculture, industry and drinking water. Removal of groundwater pollution is a time and money consuming process and often pollution is detected when improving the quality of groundwater is nearly impossible. For this vulnerability assessment there are three methods: Processing, Overlap-Index and Statistical Methods. Overlap-Index is composed of variety of maps such as Geology, Soil, Groundwater Depth and etc which uses in determining of vulnerability Index. In the present study for underground pollution potential determining, four indexes such as AVI، GOD،... 

Entrance of air to close water conduits occurs in many ways. This phenomenon makes displeasing effects on water transport structures. Two-phase flows in closed conduits are studied experimentally, numerically and theoretically. Even after decades, due to the complexity of the subject, these studies still require development and reformation. Numerical and theoretical two-phase models are often limited to a special regime of flow."Volume Of Fluid"(VOF) is a model for non-mixing two-phase flows. "Fluent" software uses this model in this field of flows. Volume of fluid is used successfully in some problems like dam break or rising bubbles. Main disadvantage of this model is distribution of the... 

Today, computer simulations are employed prevalently by researchers to understand biological processes. The tendency to use computational methods has been increased recently due to the high costs and errors of experimental methods. Integrins are membrane proteins that mechanically attach cells to the extra cellular matrix (ECM) and derive some behaviors such as cell migration. Moreover, integrins have biochemical functions. They transduce environment signals and trigger chemical pathways. As a result, integrins regulate cell shape, motility, etc. The investigation of integrin behavior in a real environment is very difficult due to the presence of many other proteins that interfere with the... 

Gene expression microarrays can be used for precision medicine and targeted therapies. The data generated by microarrays are high-dimensional causing statistical inference of any parameter a daunting task. In this thesis, it is shown that regardless of high-dimensional datasets produced by microarrays, the inference can be robust in the sense that random selection of features results in the same conclusion as far as the number of selected features are chosen appropriately. Stratifying patients with breast cancer based on their gene expression levels shows that patient subtypes are almost independent of the feature selection strategy. Moreover, using less noisy datasets coming from RNAseq... 

Diabetes mellitus is a group of disorders where the level of blood sugar remains high for a long period of time. This increase may be due to either reduced insulin secretion from the pancreatic gland, or insulin resistance, or both. Another key reason is the destruction of beta cells due to functional defect in the body’s immune system. Current treatments include controlling diet, insulin injection and pancreatic transplantation, all of which are temporary. For this reason, finding genetic factors participating in the progression of the disease and adapting treatments to these factors are under intensive studies.In this thesis, available information resources including genomic, biological... 

Distributed learning has been a popular area of machine learning for researchers according to having access to an unprecedented amount of data distributed over many clients in a network. Moreover, high dimensional learning, when the dimensions of data are high but the effective features are low, has great usage in learning especially in medical science. In this paper, we attempted to develop a method for learning high-dimensional sparse problems in a distributed manner, whit a star shape network. Our main focus in this research is on optimizing the communication flow in the network. The prominent idea of our proposed method is to extract the main feature in the first step, then continuing... 

The increasing advancement of computed tomography (CT) systems has led to the recognition of this type of imaging as an accurate and reliable method in diagnosing and assessing damage to humans and materials. Adding dual energy imaging to these systems can increase the material's ability to differentiate in this system and provide higher contrast than usual. Recently, a medical imaging technique has been introduced that uses an X-ray tube and two detector layers on top of each other, each layer absorbing a different energy spectrum.dual layer computed tomography system has been introduced today as a suitable tool for evaluating and diagnosing many diseases, due to the reliability and... 

Over the past few decades, brachytherapy has been used as one of the leading methods in the treatment of a wide range of cancers, including breast cancer. Due to the high dose gradient of brachytherapy radiation sources, this method is used to treat such tumors that are grown at the vicinity of sensitive points or tissues of the body. Therefore, as irradiation get started by implanting radiation sources in the desired position, at the same time healthy tissue are also receiving the same dose as tumor tissues do Reducing healthy tissue dose along with increasing the dose of tumor tissue is one of the challenging topics that researchers are always looking for a solution. In the left breast...