Sharif Digital Repository

The main objective of this project is the deposition of photo-catalysts on cement and concrete blocks with an emphasis on commercialization. We started with an extensive study of common methods introduced in previous literature, and conclude with a number of suggestions for industrialization. First, slurry and sol-gel deposition of the photo-catalysts on blocks of type 2 commercial cement which is one of the most used materials in construction of buildings and waste-water treatment plants has been examined to reach a method of sample formation. Due to the simplicity of common methods and low quality of formed samples (less than 5 percent aging efficiency), the obtained experience was used to... 

Design, simulation, optimization and manufacturing of an enzyme-based microfluidic biosensor has been carried out during this research to measure histamine concentration in a sample. The designed biosensor is composed of a micro-bioreactor to degrade histamine and yield hydrogen peroxide, and a chemical reactor to measure the amount of hydrogen peroxide, using chemiluminescence methods. The geometry of the bioreactor and chemical reactor is developed through comparison and optimization of several different geometries. In theory, the designed sensor can determine histamine concentration in a range of 10M to 1mM under one minute, with a maximum error of 5%. Designed biosensor is built using... 

Acceleration of healing process for crucial wounds has been remained a challenging issue and it is critical to improve treatments against infection during wound healing period. Among various antimicrobial agents, silver components has been extensively since they are resistant against a wide range of bacteria. In this study, we developed electrospun mats composed of Polycaprolactone (PCL) and Polyvinyl alcohol (PVA) loaded with major silver components using co-electrospinnig method. Chitosan- Ag nanoparticles was synthesized using chitosan via heating prior to electrospinning. Various amounts of Silver components including Ag+, Silversulfadiazine (SSD) and Chitosan- Ag NPs were added to PVA... 

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,... 

Alpha amylase enzyme is one of the most important enzymes used in a wide range of industries. The enzyme is used in industries such as detergents, food, pharmaceuticals, paper making and textile. Various national and international articles have been published on this enzyme that focused on specific targets. Despite the extensive studies carried out in this area inside the country, there is still no industrial production of alpha amylase and other enzymes in our country. In the view of the fundamental problem of the lack of industrialization of these studies, in addition to the lack of a riskier investor, it seems that there is a lack of industrial vision in these studies.In this study, the... 

Due to the high cost and destructive effects of fossil fuels, the biogas production as a renewable and environmentally friendly fuel attracted much attention. In this regard, several targets are considered in this research. First, in order to increase of biogas production yield and accelerating the rate limiting steps in anaerobic digestion of wheat straw (lignocellulosic feedstock), the effect of additives containing trace elements (Fe and Ni) in form of nanoparticles and their salts was investigated through batch experiments. The results showed that addition of nanoparticles or salts resulted in the increase of methane production rate during the first 4 days of experiments. Then, a... 

In this research, an adsorptive affinity membrane has been prepared based on the combination of the nanofiber structure’s intrinsic characteristic in the dye adsorption and its membrane filtration properties. Electrospinning method has been used to prepare chitosan/poly(vinyl alcohol) (PVA) nanofibers. The morphology and properties of the prepared nanofibrous membranes were characterized using Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), image processing, atomic force microscopy (AFM), and thermogravimetric analysis (TGA). Also, the major drawback of electrospun nanofibrous membranes (ENMs) is their low mechanical resistance. So,... 

Living in a digital era, more and more of businesses are going online. Sudden outbreak of covid19 pandemic accelerated the expansion of e-commerce and pushed an increasing number of businesses to go online. One of the most important issues in a world of e-commerce, is how to measure the results and improve the outputs. Focusing on the digital marketing, the process is usually called “conversion rate optimization”. While there is an extensive literature on various methods of improvement and optimization, we aim to do so using the notion of digital nudging, which is rather a novel concept. Digital nudging is a model that, by incorporating nudge techniques and cognitive biases, tries to change... 

Type 1 diabetes, formerly known as insulin-dependent diabetes, may present at any age, but is the most common type of diabetes affecting children and adolescents. People with type 1 diabetes do not produce enough insulin. This type accounts for 5-10% of all types of diabetes. In this type of diabetes, beta cell destruction occurs in the pancreas. In type 1 diabetes, the pancreas does not secrete any insulin; insulin is a hormone that enables the body to convert glucose in food into energy. If sugar in the blood cannot enter the cells, it accumulates in the arteries and results in high blood sugar. High blood sugar over time can have irreversible effects on various parts of the body. Curcumin... 

Beta cells are responsible for secreting insulin to maintain normoglycaemia throughout the individual’s life. Type 1 Diabetes Mellitus (T1DM) is a metabolic disorder characterized by an autoimmune response that promotes the destruction of beta-cells within the pancreatic islets, resulting in lifelong inadequate insulin secretion. Encapsulating beta cells inside a semipermeable membrane to protect encapsulated cells from direct contact with the host immune system, is a new way to treat type 1 diabetes without the need for long-term immunosuppression. . In this case, the semipermeable membrane surrounds the cells and allows oxygen, nutrients, and cell products to penetrate bilaterally while... 

Separation of biomolecules such as enzymes is the most important part of biotechnology process which 10-90 % of costs is for separation and purification. There are several methods for purification of bio materials and one of them is chromatography which use in enzyme purification but this method have several problem such as cost ,time consuming and scale up Because of this a suitable alternative demands for industrial separation. An alternative is aqueous two-phase systems (ATPS). In this project was studied about partial purification of alkaline protease produced by Bacillus licheniformis ATCC 21424 in aqueous two-phase system and comparison with chromatography method. an aqueous two-phase... 

In this research we aim to find enhance oil recovery mechanisms involved in nano-bio material injection by micro model apparatus which has not been studied before. Especially for injection in heavy oil and shaly porous media that forms most of heavy oil reservoirs. To this end, microscopic images from injection of nano-bio materials to shaly patterns have been taken and analyzed to find the process mechanism. Also amount of enhance oil recovery in different conditions like type of microbe forming bio material, nano-bio material concentration and type of flow pattern (shale characteristics including length, direction and distance from injection and production wells) will be studied.Three... 

Chlorinated hydrocarbons such as trichloroethylene form a kind of dense non-aqueous phase liquid contaminants in groundwater and soil that are so difficult to remediate. In recent years, many field research has been demonstrated application of nano scale zero valent iron can degrade these contaminants.
In this research, nZVI particle synthesized by liquid phase reduction method. Nickel (25%wt ) has been added to increase the reduction rate and also reduce intermediate pollutions. However, the combination of a noble metal to nZVI, leads to more rapid oxidation and tendency to agglomeration. So nZVI particles coated by applying a water soluble-starch solution (0.4%wt) as a stabilizer. The... 

Circulating tumor cells (CTCs) are cancer cells which shed from the primary tumor, enter circulation and spread cancer all over the body. CTCs give valuable information about cancer and can help diagnosis and prognosis. Hence separating and isolating CTCs from blood is a necessity for cancer therapeutics. CTCs are separated from blood cells by their different physical or biochemical properties. Many groups have attempted different methods for separation of CTCs. Inertial microfluidics is one of the newest approaches in CTC separation technologies which separates CTCs based on their size. Current inertial microfluidic systems containing straight, spiral, serpentine and contraction expansion... 

The best method for stabilizing sludge is anaerobic digestion, In addition to reducing the amount of volatile solids; it produces biogas, which can be considered as a sustainable energy source for wastewater treatment plants. However, the most important factor limiting the process of digestion is the sludge hydrolysis, the best way to increase the speed of hydrolysis is to pre-treatment the sludge before entering the digester; One of the most effective pretreatment methods is pre-treatment by ozone gas, This gas, which is highly unstable, quickly reacts with the wall of the bacterial cell and oxidizes it due to its high oxidizing properties And accelerates the process of sludge hydrolysis.... 

In recent years, many studies have conducted research about stem cells due to their prominent features such as proliferation and differentiation. By changing the specific parameters of the cellular micro-environment, it is possible to determine the stem cells fate and thereby use them in medical affairs. For this purpose, various devices and methods have been designeds such as microfluidic devices and scaffolds. The microfluidic devices has been especially focuced in the researchs due to their unique features, like the possibility of testing with small amounts of samples, the creation and control of low cost cellular micro-environment and low practical time. Two-dimensional scaffolds made up... 

Due to the increased public awareness about the role of food on health, an increased interest of consuming fortified food has grown rapidly. Probiotic bacteria and DHA poly-unsaturated fatty acid are two major bioactive ingredients becoming increasingly popular in food fortification industry due to their beneficial effects. However, high susceptibility of probiotic bacteria during production, maintenance and digestion in acidic and enzymatic conditions of gastrointestinal tract results in decreasing the survivability and therefore reducing health effects in body. Besides, having multiple double bonds in the structure of DHA fatty acid leads to oxidative degradation that produces volatile... 

Making artificial skin and skin alternatives is one of the most important areas in tissue engineering. Although much progress has been made so far, there is still no definitive cure for second- and third-degree burns. To create new tissue in the body, a suitable substrate for cells is needed, which is called scaffolding, and an ideal scaffold in tissue engineering should mimic the dimensions of extracellular matrix, and nanofibers seem to be the best option for this purpose. Among the methods of manufacturing of nanofibers, electrospun is very easy and accurate method. In previous studies, many natural and synthetic polymers such as chitosan, alginate, collagen, polyathylene oxide, etc.... 

Developing a simple, cost effective and accurate detection method for L-lysine (Lys), L-leucine (Leu) and glycine (Gly) as the important analytes in clinical diagnostics, biological processes and food industries is of great interest. Therefore, in the first part of this research, cellulose nanofibrils (CNFs) were coated on a quartz crystal microbalance (QCM) surface by spin coating to achieve a QCM biodetector for Gly. Thus, the two-layer CNFs coating was selected as sensing film and was applied for following experiments. In the next step, the coated QCMs were carefully characterized before and after interaction with Gly using water contact angle (WCA), Fourier transform infrared... 

Skin, the largest organ in the body, presents sophisticated functions for maintaining the structural integrity of the entire body. Skin can regulate the temperature of the body, protect the body against microorganisms, have a sensory function, and produce vitamin-D through UV exposure when in direct sunlight.Due to the self-healing property of skin tissue, skin can be repaired by itself. Nevertheless, if extensive skin loss happens, owing to diabetic ulcers or deep burns, skin will not be able to repair the wound by itself. Therefore, it will lose its functions, and the fabrication of a skin equivalent will be necessary. These skin equivalents will cover the wound, regenerate the native...