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    Modification of Gd-DTPA Contrast Agent for Targeted Drug Delivery be Nano Delivery

    , M.Sc. Thesis Sharif University of Technology Shahmanesh, Ashkan (Author) ; Hamid Reza, Maddah Hosseini (Supervisor) ; Amo Abedini, Ghasem (Supervisor)
    One of the most useful method in medical imaging is Magnetic Resonance Imaging. Gadolinium base contrast agents used to improve images contrast made by MRI. There are some problems with using these drugs, such as toxicity and lack of targeting. In this research, Silicon nanoparticles were produced by a new fashion of removing template method. Particle size was scanned by Dynamic light scattering (DLS), mesoporous structure was investigated by Brunauer-Emmett-Teller (BET), and amine functionalization was recognized by Fourier transform infrared (FTIR). Functionality was determined by evaluation of signal and relaxation of nanoparticles.T1 was defined by a 1.5 tesla power MRI device. The... 

    Fabrication and Characterization of Methanol and Hydrogen Sensors Based on Porous Silicon

    , Ph.D. Dissertation Sharif University of Technology Razi Astaraie, Fatemeh (Author) ; Iraji Zad, Azam (Supervisor)
    We studied porous silicon as a resistive gas sensor at room temperature. Meso- and macro- porous silicon were formed by electrochemical etching of single crystal silicon wafers in different conditions. For Meso porous Si we used p+-type wafers as substrate and for macro porous Si formation n- and p-type wafers were used. The mechanism of methanol vapor sensing was studied by Scanning tunneling spectroscopy and Fourier transform infrared spectroscopy. The results showed that methanol increases partial oxidation of surface and causes increase of defect density. These defects play important role to trap electrons and create “acceptor surface states”. These acceptor surface states in p+-type... 

    Effective Factors in Preventing Green Oil Formation in Chloride Adsorbents

    , M.Sc. Thesis Sharif University of Technology Talebkeikhah, Farzaneh (Author) ; Farhadi, Fathollah (Supervisor)
    In order to prevent the CCR catalysts from sintering and maintaining their acidity, some chloride compounds are added to these catalysts during regeneration process. The existence of these compounds in downstreams units and equipment causes problems such as corrosion, fouling, etc. Therefor for eliminating these chloride compounds from the exit stream a chloride adsorbent is used. The common compound that is suggested for this application is activated alumina for its high surface area. When Olefin or Aromatics exist in the stream, that is common in many units, a side reaction happens and green oil is formed. In this study, different factors in green oil formation has been studied. Although... 

    Application of Fourier Transform Infrared (FTIR) Spectroscopy of Biofluids in Disease Diagnosis

    , M.Sc. Thesis Sharif University of Technology Ganji, Mohammad (Author) ; Nejat, Hossein (Supervisor) ; Meghdari, Ali (Supervisor) ; Beigzadeh, Borhan (Co-Advisor)
    The ability to diagnose a disease rapidly, non-invasively, with high confidence level and low cost can be of great importance in many ways such as 'detection and on-time conduction of remedial strategies. Hence It can reduce fatality rate and costs in the hygiene field. Currently some pathological diagnosis methods are not suitable considering their precision and costs and in addition to that, most of them are single-function and are developed for diagnosis of a particular disease and don't perform well in the case of multiple disease factors. Many diseases are caused by metabolic disorders and thus direct study of metabolic factors can provide us with a lot of evidence on the disease. One... 

    Production of Thermoelectric Polymer Fabric and Investigation of Their Properties

    , M.Sc. Thesis Sharif University of Technology Amirabad, Reza (Author) ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Soltanieh, Mohammad (Supervisor)
    Flexible thermoelectric (TE) fabrics were prepared by dip coating of a mixture solution of water base colloidal geraphen nano sheet(GNS) and carbon nano tube(CNT) and polyaniline (PANI) on polyester fabric. The phase composition and morphology of the TE fabrics were investigated by FTIR-ATR diffraction and feld emission scanning electron microscopy. The TE properties of the PANI/GNS or CNT coated fabrics with different GNS and CNT loadings were measured in the temperature range from 303 to 338 K. As the content of GNS increased from 0.5 to 10 wt% and CNT increased from 0.5 to 20 wt%, the electrical conductivity of the PANI/GNS or CNT coated polyester fabrics increased, while the Seebeck... 

    Experimental and theoretical study of the spectroscopic properties and the preparation of 3-benzyl-2H-pyrano[3,2-c]chromene-2,5(6H)-dione

    , Article Journal of Molecular Structure ; Vol. 1065-1066, issue. 1 , May , 2014 , pp. 235-240 ; ISSN: 00222860 Moghaddam, F. M ; Foroushani, B. K ; Sharif University of Technology
    Compound 3-benzyl-2H-pyrano[3,2-c]chromene-2,5(6H)-dione(3), was prepared and fully characterized. The vibrational modes (FT-IR) and NMR data ( 1H and 13C chemical shifts) were compared with the results of Density Functional Theory (DFT) method at the B3LYP/cc-PVTZ level. The calculated vibrational frequencies and NMR chemical shifts are in good agreement with the experimental results. The electronic (UV-Vis) spectrum was calculated using the TD-DFT method in CH2Cl2 with the Polarizable Continuum Model using the integral equation formalism variant (IEFPCM) and was correlated to the experimental spectra. The assignment and analysis of the frontier HOMO and LUMO orbitals indicate that... 

    Characterization of optical properties of amorphous BaTiO3 nanothin films

    , Article Journal of Non-Crystalline Solids ; Volume 355, Issue 50-51 , 2009 , Pages 2480-2484 ; 00223093 (ISSN) Ashiri, R ; Nemati, A ; Sasani Ghamsari, M ; Aadelkhani, H ; Sharif University of Technology
    Amorphous barium titanate nanothin films were prepared by sol-gel dip-coating method. According to transmission spectrum, the refractive index and optical band gap of nanothin films have been determined. High transmission spectrum without any fluctuation in visible wavelength region was recorded. Experimental results indicated that the surface morphology of prepared nanothin films were improved and as a result of that, a better optical properties, less optical losses and higher band gap width were obtained in contrast with other reported data. It was found that optical propagation loss of BaTiO3 nanothin film was much lower than normal polycrystalline BaTiO3 thin film. It seems to us that,... 

    Dye Removal from Wastewater using Copper based Amine Modified Nanoparticle in Single and Binary System

    , M.Sc. Thesis Sharif University of Technology Ghezelbash, Mina (Author) ; Ghotbei, Cyrus (Supervisor) ; Mahmoodi, Niyaz Mohammad (Supervisor) ; Kazemeini, Mohammad (Supervisor)
    During the recent years, shortage of drinking water is one of the concerns of the society and necessity of purification of contaminated water are taken into consideration. Different methods to be developed to prevent problematic pollutions. Among these different methods the most common one is adsorption. In this thesis, the copper oxide nanoparticle was synthesized and its surface was modified using N-(2-aminoethyl)-3-(trimethoxysilyl)propylamine. The bi-amino surface functionalized nanoparticle was used to remove anionic dyes from single and binary systems. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDAX)... 

    Theoretical and Experimental Investigation of WAX Precipitation in Crude Oil Transportation Pipelines

    , Ph.D. Dissertation Sharif University of Technology Mashhadi Meighani, Hossein (Author) ; Ghotbi, Cyrus (Supervisor) ; Jafari Behbahani, Taraneh (Supervisor) ; Sharifi, Khashayar (Co-Supervisor)
    Wax precipitation may occur in production or transportation of crude oil form field which is a serious problem in petroleum industry. Flow assurance issues concerning wax precipitation make it necessary to develop a precise thermodynamic model to predict the wax appearance temperature and amount of precipitation at different conditions. In this work a new procedure has been proposed to characterize crude oil based on the SARA test considering the wax and asphaltene as single pseudo components. Two scenarios have been investigated for the survey of the crude oil characterization, with and without asphaltene pseudo component. Also, in this work, the Perturbed ... 

    Synthesis and characterization of a novel (salep phosphate)-based hydrogel as a carrier matrix for fertilizer release

    , Article Reactive and Functional Polymers ; Volume 72, Issue 10 , 2012 , Pages 667-672 ; 13815148 (ISSN) Pourjavadi, A ; Doulabi, M ; Soleyman, R ; Sharif, S ; Eghtesadi, S. A ; Sharif University of Technology
    Elsevier  2012
    Salep phosphate modified biopolymers with different phosphate contents were prepared via reacting salep (a multi-component polysaccharide obtained from dried tubers of certain natural terrestrial orchids) with a solution of primary and secondary sodium phosphates under basic conditions in a semidry process. Structural characterization of salep phosphates were carried out by 31P NMR, FT-IR spectra and TGA curves. Determination of the phosphate content in samples was done by a standard spectrophotometric method. Then, novel (salep phosphate)-based hydrogels were synthesized by graft copolymerization of acrylic acid (AA) monomer onto salep phosphate backbones. Effect of the phosphate contents... 

    A study of the electrophoretic deposition of bioactive glass-chitosan composite coating

    , Article Ceramics International ; Volume 38, Issue 1 , January , 2012 , Pages 471-476 ; 02728842 (ISSN) Mehdipour, M ; Afshar, A ; Sharif University of Technology
    Bioactive glass is coated on implant's surface to improve corrosion resistance and osseointegration, when placed in the body. Bioactive glass particles were synthesized through a sol-gel process and deposited along with chitosan to form a composite coating on a stainless steel substrate using electrophoretic deposition technique. Stable suspensions of chitosan-bioactive glass were prepared using bioactive glass particles (<1 μm) and 0.5 g/l chitosan solution. The influence of ethanol-water ratio on deposition yield was investigated. For all process conditions, best results were achieved with suspension of 30 vol% water in ethanol-water containing 2 g/l bioactive glass. FTIR studies showed... 

    Ultrasonic-assisted synthesis of magnetite based MRI contrast agent using cysteine as the biocapping coating

    , Article Materials Chemistry and Physics ; Volume 131, Issue 1-2 , 2011 , Pages 170-177 ; 02540584 (ISSN) Ahmadi, R ; Malek, M ; Hosseini, H. R. M ; Shokrgozar, M. A ; Oghabian, M. A ; Masoudi, A ; Gu, N ; Zhang, Y ; Sharif University of Technology
    Magnetite nanoparticles (mean particle size ranging from 10 to 20 nm) were prepared by a biomoleculeassisted solution-phase approach under ultrasonic irradiation. Cysteine was used as the capping agent in the solution. The results show that cysteine could be an efficient biocapping agent in producing Fe3O4 nanoparticles. The crystal structure and magnetic properties of the nanoparticles were characterized by XRD and VSM techniques, respectively. FT-IR was used to investigate the presence of cysteine on the nanoparticles surface. The influence of pH value of the solution on the size distribution and hydrodynamic size of nanoparticles were studied by TEM and DLS methods, respectively. The MTT... 

    Study and production of silicone rubber and polyethylene alloy

    , Article Journal of Thermoplastic Composite Materials ; Volume 24, Issue 5 , 2011 , Pages 669-677 ; 08927057 (ISSN) Tavakkoli, H ; Meibod, M. P ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    Linear silicone rubber and polyethylene alloy produced from extrusion-injecting process will be present in separate phases. While samples are mixed with 1% dicumylperoxide, DCP, and injected in extruder, an alloy is almost formed. In addition, when the samples containing silicon rubber with vinyl group are mixed with polyethylene and passed in the vicinity of electron beam, a similar reaction occurs, as confirmed from FTIR spectrum. The water contact angles for the samples has been listed in the article. Furthermore, the crystallinity of samples produced via electron beam method is more than that obtained from peroxide method. On the other hand, the tensile strengths of produced samples via... 

    Sol–gel preparation and corrosion properties of Zn–SiO2 nanocomposite thin film

    , Article Journal of Sol-Gel Science and Technology ; Volume 79, Issue 1 , 2016 , Pages 133-143 ; 09280707 (ISSN) Razavizadeh, O ; Ghorbani, M ; Sharif University of Technology
    Springer New York LLC 
    In this study, a novel nanocomposite thin film of Zn–SiO2 is considered. The thin film is a viable alternative for higher abrasion-resistant coatings. DLS technique revealed that the nanoparticle size is to be below 10 nm, and FE-SEM showed particle size to be below 17 nm in the obtained coating. The coating was found to be highly adhesive with an amorphous structure and hardness value above 1000HV. Corrosion resistance studies using linear polarization technique revealed that this unique nanocomposite has a lower corrosion rate than hot-dip galvanized steel at higher positive potentials. A conclusive mechanism for corrosion and erosion improvement has been proposed. Graphical Abstract:... 

    Key parameters in hydrothermal synthesis and characterization of low silicon content SAPO-34 molecular sieve

    , Article Microporous and Mesoporous Materials ; Volume 126, Issue 1-2 , 2009 , Pages 1-7 ; 13871811 (ISSN) Izadbakhsh, A ; Farhadi, F ; Khorasheh, F ; Sahebdelfar, S ; Asadi, M ; Yan, Z. F ; Sharif University of Technology
    Low silicon content SAPO-34 was successfully synthesized using the conventional hydrothermal crystallization in the static condition. Effects of different synthesis conditions including crystallization temperature and the silicon source were investigated through X-ray diffraction patterns. It was concluded that the silicon source had a significant effect on silicon incorporation into the alumino-phosphate building blocks in the course of crystallization. Using precipitated silica instead of silica sol resulted in the formation of impurities of alumino-phosphates phases whose crystalline structures collapse at the high temperature of calcination. For the low silicon SAPO-34 synthesis, the... 

    Synthesis and swelling behavior of a new superabsorbent hydrogel network based on polyacrylamide grafted onto salep

    , Article Journal of Applied Polymer Science ; Volume 112, Issue 5 , 2009 , Pages 2625-2633 ; 00218995 (ISSN) Pourjavadi, A ; Rezanejade Bardajee, G ; Soleyman, R ; Sharif University of Technology
    Synthesis and swelling behavior of a new superabsorbent hydrogel based on natural salep grafted with Polyacrylamide is described. The new superabsorbent hydrogel biopolymer was synthesized via radical crosslink-ing and graft copolymerization of acrylamide monomer onto salep backbones. Regarding to the water absorption of hydrogel, the best synthesis condition is reported. FTIR spectroscopy and thermogravimetric analysis were used to confirm the structure of the final product and a mechanism for superabsorbent hydrogel formation was also suggested. After preparing the desired hydrogels based on optimum condition, several factors affecting the swelling behavior of hydrogel including pH of... 

    The effects of SiO 2 and K 2O on glass forming ability and structure of CaOTiO 2P 2O 5 glass system

    , Article Ceramics International ; Volume 38, Issue 4 , 2012 , Pages 3281-3290 ; 02728842 (ISSN) Ahmadi Mooghari, H. R ; Nemati, A ; Eftekhari Yekta, B ; Hamnabard, Z ; Sharif University of Technology
    The effects of SiO 2 and K 2O were investigated on the glass forming ability (GFA) and structural characteristics of CaOTiO 2P 2O 5 system. Differential thermal analyzer (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR and 31P magic angle spinning NMR methods were applied for characterizations of the system. Unwanted crystallization in the initial three components base glass composition was observed by adding SiO 2 and crystalline phases such as TiP 2O 7, rutile (TiO 2) and cristobalite (SiO 2) were formed in it. The results showed that K 2O prevents crystallization of glasses and promotes the formation of glass. FT-IR and X-ray diffraction showed that the addition... 

    Synthesis and thermal behavior of Mg-doped calcium phosphate nanopowders via the sol gel method

    , Article Scientia Iranica ; Volume 18, Issue 6 , 2011 , Pages 1614-1622 ; 10263098 (ISSN) Gozalian, A ; Behnamghader, A ; Daliri, M ; Moshkforoush, A ; Sharif University of Technology
    The aim of this study was to investigate the thermal behavior of Mg-doped calcium phosphate compounds. Nanocrystalline HA and β-TCP mixtures containing different magnesium contents were synthesized via an alkoxide sol gel method. The ratio of (Ca+Mg)P was kept constant at 1.67, and the Mg content ranged between 0 and 3 mol%. The influence of magnesium on the phase composition, chemical structure, thermal behavior and morphological characteristics of nanopowders was analyzed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Simultaneous Thermogravimetry and Differential Thermal Analysis (STA/DTA), Scanning Electron Microscopy (SEM) and Transmission Electron... 

    Polycarbonate surface cell's adhesion examination after Nd:YAG laser irradiation

    , Article Materials Science and Engineering C ; Volume 29, Issue 4 , 2009 , Pages 1491-1497 ; 09284931 (ISSN) Ramezani Saadat Abadi, A ; Mousavi, A ; Seyedjafari, E ; Poursalehi, R ; Sareh, S ; Silakhori, K ; Poorfatollah, A. A ; Shamkhali, A. N ; Sharif University of Technology
    Nd:YAG laser treatment was used in order to increase surface cell adhesion aspects of polycarbonate (PC) films prepared via melt process. The treatment was carried out under different wavelengths and beam diameters. ATR-FTIR and UV spectra obtained from different samples before and after laser treatment in air showed that laser irradiation has induced some chemical and physical changes in surface properties. The irradiated films were also characterized using scanning electron microscopy (SEM) and contact angle measurements. Effect of pulse numbers on the surface properties was also investigated. Cell culture test was used to evaluate cell adhesion property on the PC films before and after...