Sharif Digital Repository

Despite the increase in the number of cardiovascular diseases worldwide, the number of new drugs to treat these diseases has been decreasing in the last decade. Current preclinical drug evaluation strategies, which use cell cultures and oversimplified animal models, cannot meet the growing demand for new and effective drugs. In the last decade, the development of microfluidic bioreactors and organ-on-chip systems to improve the drug screening process has been increasing significantly. These systems have shown many advantages over previous preclinical models. Despite all these advantages, keeping the oxygen concentration at the optimal physiological level in microfluidic systems has its own... 

Organ-on-chip microfluidic devices create a three-dimensional and dynamic model that allows researchers to model diseases and test different drug candidates. In this regard, using a lung-on-a-chip microfluidic device, Covid-19 disease was numerically modeled. Initially, the distribution of oxygen concentration in the blood and respiratory membrane in the healthy state; when the respiratory membrane is the only barrier between air and blood; was found and observed that in this case, the length that the blood had to travel to reach full saturation was the same in the alveolar capillaries and the lung-on-a-chip microdevice. Then, to simulate the different phases of the disease, the formation of... 

In this study, chitosan-based nanoparticles were prepared due to their biocompatibility, availability, high loading capacity of drug, stimulus responsive behavior and the presence of active functional groups. Chitosan was chemically functionalized with reactive oxygen species (ROS)-responsive moiety to respond to the oxidative stess and endosomal pH in nerve injuries. To prepare nanoparticles, functinalized chitosan ionically gelated with pH-responsive polyanions with ROS-scavenging properties such as polyacrylic acid and hyaluronic acid. Then, pH- and ROS-responsive nanoparticles were used for selective transfection into reactive astrocytes and axonal regeneration in spinal cord injuries.... 

The bronchial tree consists of two main parts: conducting airways and respiratory airways. Parametric Lindenmayer System (L-System) has been used for modeling of the structure. The conducting airways are divided into two parts: central region consisting of trachea up to segmental bronchi and bronchioles located in the bronchopulmonary segments. The boundary of these segments has been found by image processing techniques. Stochastic Parametric L-system has been used for modeling of acinar region. To find the characteristic properties of conducting airways and respiratory bronchioles, an intelligent method has been developed. The parameters of the model are either age dependent or... 

Treatment of Wastewater of textile industries has been always challenging due to the high organic matter which is a suitable substrate for the growth of microorganisms. Also, discharge of wastewater into the open water causes water adsorbing more sunlight, raising water temperature and therefor decreasing dissolved oxygen. In addition, the acidity of wastewater decreases the quality of agricultural soil. Among wastewater treatment methods, biological methods are cheaper, environment friendly, and produce less by product. Among all the microorganism responsible for biological treatment, fungi and enzymes are more applicable. Especially white-rot fungi are the most effective microorganism to... 

In the present study, the electrochemical oxidation process was introduced as a green process for complete degradation and removal of non-biodegradable pollutants from aquatic environments and effluents of various industries without the need to use chemicals and toxins. Research stages include comprehensive preliminary studies in the field of electrochemistry and wastewater treatment, software design of electro-oxidation reactor using titanium mesh anode and stainless steel cathode mesh inside a body made of polypropylene, designed cell construction and then evaluation of device performance in polluting environment Are different. In software simulation using COMSOL MULTIPHYSICS software, it... 

Today cancer is one of the leading causes of death worldwide. It is caused by some cells that they gather together in part of the body and they have an abnormal and very high proliferation rate. Investigations on tumors have shown that when tumor volume increases, oxygen concentration in some regions of tumors decreases and this hypoxic condition leads to some cancer hallmarks, e.g. angiogenesis, deregulation of apoptosis, and shift in cell energy sources. So treatment strategies that can increase tissue oxygenation are good choices for cancers. Hyperbaric oxygen therapy (HBOT) which is used to treat diabetic ulcers and carbon monoxide poisoning, have been used experimentally for cancer and... 

Antibiotic medications are widely used in medicine and veterinary medicine. Since these drugs are extremely dangerous to the environment and specially to drinking water for humans and other organisms, the need to treat these wastewater is becoming increasingly important. One of the most commonly used antibiotics is oxytetracycline which is used for a wide range of infectious diseases Husbandry wastewater is one of the wastewaters that contains high diversity and large amounts of antibiotics. In this study, the performance of a Moving bed biofilm reactor (MBBR) was investigated for removal of oxytetracycline from synthetic wastewater with similar characteristics to Husbandry wastewater. A... 

Oxygen enriched combustion is one of the attractive combustion technologies to control pollution and improve combustion in diesel engines. In the present work after an introduction to membrane seperation and membrane seperators for oxygen-nitrogen from air, a simulation of combustion chamber by GT-Power and membrane COMSOL Multiphysics was used to study the impact of oxygen enrichment on combustion, pollution and performance parameters with 23, 25 and 27% levels of enrichment. Increasing the oxygen engine content with the air leads to faster burn rates and the ability to burn more fuel at the same stoichiometry. These effects have the potential to decrease specific fuel consumption and... 

Drug delivery systems (DDS), which, are sensitive to tumor medium have high importance. one of the most important problem of current treatment of cancer is damage of the normal tissue, which, it is expected to solve by smart drug delivery systems. In such cases, one or more features of cancer medium cause to release of the drug. One of features of cancer medium is high concentration of reactive oxygen species and hydrogen peroxide in the most common between them. The purpose of this study is to build a drug delivery system, which it is sensitive to hydrogen peroxide. This carrier has 4 main parts. The first part is anti-cancer drug, which, it is located in the carrier. Second part is... 

Discharging treated or raw waste water in to surface water may cause lots of serious problems, including growth of algae, as a result of the presence of nutrients in waste water.algae decrease the concentration of dissolve oxygen in water.phosphorus removal from waste water is of absolute necessity. according to the standards set by the environmental organization, discharge the untreated waster water in to the surface water is not allowed. on the other hand, given manager facilities of deprived area,effort is channeled to reach the desired result through designing the simplest treatment systems. anaerobic-aerobic systems have remarkably been used for many years in the treatment of urban and... 

Biological treatment is an essential part of wastewater treatment. One of the major problems of the biological treatment systems is a solid separation. Filamentous bulking is a type of solid separation problem that settled sludge volume and the turbidity of the effluent will be increase in bulking condition. The presence of excessive Filamentous bacteria causes filamentous bulking. In this thesis, filamentous bulking were studied to understand this phenomena better and tried to control that with the different methods. This research was conducted in laboratory scale Sequencing Batch Reactor (SBR), conventional activated sludge and conventional activated sludge with anaerobic selector with... 

Pharmaceutical waste has attracted considerable attention, in the Past two decades. These pollutants had not previously been detected in the environment. In fact, the concentration of pharmaceuticals became a matter of concern after the increase in the production and consumption of drugs. Nowadays, considering their higher consumption and more developed detection technologies, they are found in waste water, treated water, rivers, etc. The purpose of this research is to study treatment of a Synthetic waste water contaminated by Diclofenac and Ibuprofen in a Moving Bed Biofilm Reactor. An aerobic Moving Bed Biofilm Reactor (MBBR) with the volume of 8.5 liters and Kaldness packing filling ratio... 

In this study, the use of a fixed bed of the Kaldnes commercial carrier in the activated sludge system has been investigated. In this way, at zero time, a submerged fixed bed of Kaldnes was placed into a completely mixed activated sludge reactor and its various parameters were investigated during the time. During the experiment, the fixed bed (Kaldnes carriers enclosed in a lace) with 20, 35 and 50 percentage of volumes were compared to regular activated sludge reactors (without any carriers). The studied parameters are COD, DO, MLSS, and P-PO43-. Input COD was changed at concentrations of 1200 and 400 mg/L, and the reactor hydraulic time was adjusted to 10 and 16 hours. It was observed that... 

In this research, start-up, performance and stability of a A2O system (Anaerobic/ Anoxic/ Oxic) combined with a Moving Bed Bio Reactor (MBBR), using Kaldnes packings, have been investigated in treating synthetic dairy wastewater. Also the effect of influent Chemical Oxygen Demand (COD), Hydroulic Retention Time (HRT) and Ruturn Activated Sludge (RAS) ratio on removing pollutants such as COD, Total Nitrogen and Total Phosphorous have been studied. The experiments have been designed using ‘Design Of Experiments’ software, and at the end the results have been optimized based on desired terms. The performance and capability of the reactor in removing pollutants in 8, 12 and 16 hours of HRT,... 

Core-shell structures of Ag@Pt nanoparticles (NPs) dispersed on Carbon Vulcan XC-72, Multiwalled carbon nanotube and reduced graphene oxide (rGO) support containing different Ag:Pt mass ratios and applied to the oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell (PEMFC) were synthesized by the ultrasonic and reduction treatment method. The morphology of as-prepared catalysts characterized by the high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and induced coupled plasma atomic emission spectroscopy (ICP-OES). The ORR activities and stabilities of catalysts were studied through electrochemical measurements utilizing the Cyclic Voltammetry... 

In this research, the capability of an aerobic moving bed biofilm reactor (MBBR) for removal of phenol from Arak refinery dilute wastewater has been investigated. A cubical MBBR with approximate capacity of 10 liters was filled with Kaldnes-K1 biocarriers at filling ratio at 50 percent. Moreover, The MBBR which filled with actual refinery wastewater, combined with Flocculation and Coagulation in order to removing more COD, turbidity and TSS and also reaching to criterion that water can be used by cooling tower. The effects of Phenol concentration (10-100 mgl-1), COD concentration (50-500 mgl-1), Hydraulic Retention Time (HRT) (4-12 h) and Phenol shocks on the performance of MBBR were... 

In various industries, for energy production, fossil fuels are burned. Oxygen needed for combustion, taken directly from the ambient air; So that the inert gas is about 80%. The presence of this inert gas, mainly nitrogen, reduce combustion efficiency and increase the use of combustible material. In this project with the help of membrane technology, was used to remove the amount of nitrogen in the air so that the incoming air into the combustion chamber is enriched with oxygen. For this purpose, several gas separation membrane was applied and evaluated. Then, according to the oxygen enrichment, fuel efficiency and the amount of savings, increasing chamber temperature, reduction manufacturing... 

Water is one of the world’s most valuable resources, yet it is under constant threat due to climate change, explosive population growth, and waste. One of the most promising efforts to stem the global water crisis is river contaminated, water reclamation and reuse. This study was carried out to investigate in the water quality “S. H. C.” using treatment techniques. Research project was to check out which method give maximum removal of TOC, COD and coliform, fecal coliform and TSS where this parameters exceeded the permissible limits and therefore “S. H. C.” water was contaminated by these parameters. After carrying out the study more from 8 month on water treatment "S. H. C." we get the... 

The main objective of this research was to evaluate the application of a new strain of Brevundimonas naejangsanensis which is newly identified sulfate-reducing bacteria (SRB), in bioremediation. A laboratory scale packed bed reactor (PBR) was fabricated and operated to study the new bacteria’s feasibility on SO_4^(2-) reduction. The reactor was packed with polyurethane foam cubes and operated under different feeding and operating conditions of HRT, COD/SO_4^(2-) ratio and salinity. A maximum SO_4^(2-) reduction of 73.6% was achieved in the PBR when operated at an HRT of 12 h with SO_4^(2-) concentration of 670 mg/L, COD/SO_4^(2-) ratio of 1 and salinity of 3%. The results show that this...