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    Effect of Urease on the Motion of Janus Micromotors Based on Black Titanium Dioxide

    , M.Sc. Thesis Sharif University of Technology Hassani, Atefeh (Author) ; Madaah Hosseini, Hamid Reza (Supervisor)
    Abstract
    The bladder is one of the most important internal organs of human that improper functioning of this organ causes various diseases such as bladder exstrophy, bladder syndrome, bladder cancer and bladder infection. The main challenge in treating these diseases is the presence of a mucous layer consisting of glycosaminoglysis (GAG) in the bladder wall that prevents drugs from reaching the surface of the bladder. Hence, drug delivery through the mucosal layer is not easy, Hence, urease micro/nano carriers have recently been considered for the treatment of bladder diseases. In this study, new janus micromotors based on black titanium oxide with asymmetric urease catalytic coating were synthesized... 

    Measuring Concentration of Heavy Metals in Waste Water Using Biosensor

    , M.Sc. Thesis Sharif University of Technology Heydarian Dolatabadi, Ehsan (Author) ; Alemzadeh, Iran (Supervisor) ; Kalantarian, Asadollah (Supervisor)
    Abstract
    Wastewater, especially with heavy metal contamination, is a global environmental concern. Numerous techniques have been tested for online controlling and monitoring the concentration of heavy metal ions; yet, there are many challenges in performing these techniques. Biosensor is cheap, easily available, simple, fast, selective, sensitive, and repeatable so it is an excellent alternative for the detection and quantification of hazardous particles in the wastewater. In this study, a Nano biosensor with high detection of copper ions has been fabricated. PEDOT:PSS as a highly conductive polymer is coupled with gold nanoparticles to modify the surface of graphite electrode and results in higher... 

    Fabrication of Janus Micromotors Based on Black Titanium Dioxide for Medical Application

    , M.Sc. Thesis Sharif University of Technology Amiri, Zahra (Author) ; Madaah Hosseini, Hamid Reza (Supervisor) ; Tavakoli, Rohollah (Co-Supervisor)
    Abstract
    Enzyme-powered motors self-propel through the catalysis of biofuels, which makes them excellent candidates for biomedical applications. However, fundamental issues such as their movement in biological fluids and understanding the mechanism of propulsion are important aspects that must be considered before application in biomedicine. Building active systems based on biocompatible materials that use non-toxic fuels to power their vehicles have always been challenging. In this study, self-propelled micromotors consist of titanium dioxide black spheres asymmetrically coated with a thin layer of gold. Cysteine was used to bind urease enzyme due to thiol binding. By biocatalytically converting... 

    Constructing Calcite Core by Microbially Induced Calcite Precipitation (MICP) Usable in Oil and Gas Tests

    , M.Sc. Thesis Sharif University of Technology Ali Doust Salimi, Nazanin (Author) ; Yaghmaei, Soheila (Supervisor) ; Bazargan, Mohammad (Supervisor) ; Ghobadi Nejad, Zahra (Co-Supervisor)
    Abstract
    Acidizing is the most widely performed job to remove the formation damage, and enhance the oil recovery. Different models have been introduced to design the optimized condition for acidizing. However, none of them are able to predict the optimum injection flow rate in the actual application. As a result, Calcite cores are extracted from reservoirs for conducting experiments and modifying the present models. Nevertheless, acidizing is an intrusive technique destroying the costly extracted cores. Thus, there is a need to construct calcite cores of various porosities and permeabilities to take advantage of them in acidizing modelling.Microbially induced calcite precipitation is a well-known... 

    Construction of porous calcite structure using microbially induced calcite precipitation

    , Article Journal of Petroleum Science and Engineering ; Volume 217 , 2022 ; 09204105 (ISSN) Alidoustsalimi, N ; Bazargan, M ; Ghobadi Nejad, Z ; Yaghmaei, S ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Sporosarcina pasteurii is a well-known ureolytic bacteria that promotes the microbially induced calcite precipitation (MICP) process for several environmental and engineering purposes. In our work, for the first time, MICP has been implemented to form pure, porous calcite structures. The maximum urease activity of S. pasteurii was 1.91 mM urea hydrolyzed min−1 at the late-exponentially phase. A reactor has been designed to achieve semi-continuous treatments, and reagents were introduced to it by a peristaltic pump. A new alternating injection pattern was adopted to obtain well-distributed precipitation. SEM images of treated structures indicated the shapes of CaCO3 crystals at a microscale...