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physical-and-chemical-properties
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Physical and chemical properties of lamb renal capsule irradiated by ArF laser
, Article Journal of Laser Applications ; Volume 27, Issue 1 , 2015 ; 1042346X (ISSN) ; Parvin, P ; Reyhani, A ; Mortazavi, S. Z ; Baghapour, Sh ; Amjadi, A ; Sharif University of Technology
Abstract
Excimer laser at 193 nm was irradiated on the renal tissues during various exposure times in order to investigate the chemical and physical surface properties using Fourier transform infrared spectroscopy, photo electron spectroscopy, contact angle measurements, and tensile test accordingly. We have shown that ultraviolet laser strongly alters the oxygen content of skin layer that causes changes in the tissue morphology leading to significant skin hydrophilicity
Electrically rotating suspended films of polar liquids
, Article Experiments in Fluids ; Volume 50, Issue 2 , August , 2011 , Pages 419-428 ; 07234864 (ISSN) ; Amjadi, A ; Tonddast Navaei, A ; Ejtehadi, M. R ; Sharif University of Technology
Abstract
Controlled rotation of a suspended soap water film, simply generated by applying an electric field, has been reported recently. The film rotates when the applied electric field exceeds a certain threshold. In this study, we investigate the phenomenon in films made of a number of other liquids with various physical and chemical properties. Our measurements show that the intrinsic electrical dipole moments of the liquid molecules seems to be vital for the corresponding film rotation. All the investigated rotating liquids have a molecular electric dipole moment of above 1 Debye, while weakly polar liquids do not rotate. However, the liquids investigated here cover a wide range of physical...
Hydrogen-deuterium chemical exchange in supercritical water: Thermodynamic considerations for optimizing the synthesis of high degree deuterated benzene
, Article Journal of Supercritical Fluids ; Volume 125 , 2017 , Pages 96-103 ; 08968446 (ISSN) ; Hosseinpour, M ; Mohammadnezhad, F ; Ahmadi, S. J ; Khazayi, M. A ; Sharif University of Technology
Abstract
In the light of the novel physical-chemical properties of supercritical water as a green reaction medium, we studied the synthesis of deuterated benzene in supercritical heavy water, in the presence of sodium deutroxide, as a catalyst. The effects of operational parameters including temperature, time, pressure (density), catalyst amount and benzene/D2O volumetric ratio on the degree of deuteriation (D%) and deuterated benzene yield were investigated extensively and the conditions for the highest degree of deuteration and product yield, were optimized. Furthermore, because of the importance of the pressure of solution inside the reaction medium on the H/D exchange process as well as the...
Polymer-functionalized carbon nanotubes in cancer therapy: A review
, Article Iranian Polymer Journal (English Edition) ; Vol. 23, issue. 5 , May , 2014 , p. 387-403 ; Hosseini, S. H ; Adeli, M ; Pourjavadi, A ; Sharif University of Technology
Abstract
The increasing importance of nanotechnology in the field of biomedical applications has encouraged the development of new nanomaterials endowed with multiple functions. Novel nanoscale drug delivery systems with diagnostic, imaging and therapeutic properties hold many promises for the treatment of different types of diseases, including cancer, infection and neurodegenerative syndromes. Carbon nanotubes (CNTs) are both low-dimensional sp2 carbon nanomaterials exhibiting many unique physical and chemical properties that are interesting in a wide range of areas including nanomedicine. Since 2004, CNTs have been extensively explored as drug delivery carriers for the intracellular transport of...
Experimental investigation of forced convective heat transfer coefficient in nanofluids of Al2O3/EG and CuO/EG in a double pipe and plate heat exchangers under turbulent flow
, Article Experimental Thermal and Fluid Science ; Volume 35, Issue 3 , April , 2011 , Pages 495-502 ; 08941777 (ISSN) ; Oskouie, S. N ; Doosthoseini, A ; Joneidi, A ; Pazouki, M ; Sharif University of Technology
2011
Abstract
Nanofluid is the term applied to a suspension of solid, nanometer-sized particles in conventional fluids; the most prominent features of such fluids include enhanced heat characteristics, such as convective heat transfer coefficient, in comparison to the base fluid without considerable alterations in physical and chemical properties. In this study, nanofluids of aluminum oxide and copper oxide were prepared in ethylene glycol separately. The effect of forced convective heat transfer coefficient in turbulent flow was calculated using a double pipe and plate heat exchangers. Furthermore, we calculated the forced convective heat transfer coefficient of the nanofluids using theoretical...
Ugi four-component assembly process: An efficient approach for one-pot multifunctionalization of nanographene oxide in water and its application in lipase immobilization
, Article Chemistry of Materials ; Volume 28, Issue 9 , 2016 , Pages 3004-3016 ; 08974756 (ISSN) ; Akhavan, O ; Hashemi, E ; Shamsara, M ; Sharif University of Technology
American Chemical Society
2016
Abstract
Graphene-based materials are revealing the leading edge of advanced technology for their exceptional physical and chemical properties. Chemical manipulation on graphene surface to tailor its unique properties and modify atomic structures is being actively pursued. Therefore, the discovery of robust and general protocols to anchor active functionality on graphene basal plane is still of great interest. Multicomponent reactions promise an enormous level of interest due to addressing both diversity and complexity in combinatorial synthesis, in which more than two starting compounds react to form a product derived from entire inputs. In this article, we present the first covalent...
Silver and gold nanoparticles for antimicrobial purposes against multi-drug resistance bacteria
, Article Materials ; Volume 15, Issue 5 , 2022 ; 19961944 (ISSN) ; Ahmadi, S ; Akhavan, O ; Luque, R ; Sharif University of Technology
MDPI
2022
Abstract
Several pieces of research have been done on transition metal nanoparticles and their nanocomplexes as research on their physical and chemical properties and their relationship to biological features are of great importance. Among all their biological properties, the antibacterial and antimicrobial are especially important due to their high use for human needs. In this article, we will discuss the different synthesis and modification methods of silver (Ag) and gold (Au) nanoparticles and their physicochemical properties. We will also review some state-of-art studies and find the best relationship between the nanoparticles’ physicochemical properties and potential antimicrobial activity. The...
A photocatalytic approach in micro arc oxidation of WO3-TiO 2 nano porous semiconductors under pulse current
, Article Materials Chemistry and Physics ; Volume 128, Issue 3 , 2011 , Pages 427-432 ; 02540584 (ISSN) ; Golestani Fard, F ; Moshfegh, A. Z ; Molaei, R ; Sharif University of Technology
2011
Abstract
Since ultraviolet (UV) irradiation cannot be applied for a long time in practical applications, it is necessary to develop a narrow band gap photocatalyst to decompose environmental pollutants under visible irradiation. In this research, (WO3)x-(TiO2)1-x nano-porous layers were fabricated by micro arc oxidation (MAO) and influence of the electrical current type on their physical and chemical properties was investigated. Morphological studies, performed by SEM technique, revealed that pore size and roughness decreased with the frequency and increased with the duty cycle. The pulse-grown layers had a finer structure when compared to those fabricated under direct current. XRD and XPS results...
On the photocatalytic activity of the sulfur doped titania nano-porous films derived via micro-arc oxidation
, Article Applied Catalysis A: General ; Volume 389, Issue 1-2 , 2010 , Pages 60-67 ; 0926860X (ISSN) ; Moshfegh, A. Z ; Golestani Fard, F ; Sharif University of Technology
2010
Abstract
Sulfur doped TiO2 layers containing nano/micro-sized pores were synthesized by micro-arc oxidation process. Effect of the applied voltage and the electrolyte composition on physical and chemical properties of the layers was investigated using SEM, AFM, XRD, XPS, and EDS techniques. A UV-vis spectrophotometer was also used to study optical properties of the layers. It was found that the doped layers were porous with a pore size of 40-170 nm. They consisted of anatase and rutile phases with varying fraction depending on the applied voltage and electrolyte concentration. Our XPS investigations revealed the existence of sulfur in the forms of S4+ and S6+ states which substituted Ti4+ in the...
Influence of nano-SiO2 addition on microstructure and mechanical properties of cement mortars for ferrocement
, Article Transportation Research Record ; Issue 2141 , 2010 , Pages 15-20 ; 03611981 (ISSN) ; Booshehrian, A ; Farshchi, S ; Sharif University of Technology
Abstract
Because of their unique physical and chemical properties, nanoparticles have been gaining increasing attention and have been used in many fields to fabricate new materials with novel functions. If nanoparticles are integrated with cement-based building materials, the new materials might possess some outstanding properties. Ferrocement is a type of thin-wall reinforced concrete commonly constructed of hydraulic cement mortar reinforced with closely spaced layers of continuous and relatively small-sized wire mesh. The low level of technical skill required to make ferrocement and the ready availability of its materials make ferrocement suitable for a wide variety of applications. This study...
Characterization and transesterification of Iranian bitter almond oil for biodiesel production
, Article Applied Energy ; Volume 88, Issue 7 , 2011 , Pages 2377-2381 ; 03062619 (ISSN) ; Kariminia, H. R ; Sharif University of Technology
2011
Abstract
In the present work the production of biodiesel using bitter almond oil (BAO) in a potassium hydroxide catalyzed transesterification reaction was investigated. The BAO was obtained from resources available in Iran and its physical and chemical properties including iodine value, acid value, density, kinematic viscosity, fatty acid composition and mean molecular weight were specified. The low acid value of BAO (0.24. mg. KOH/g) indicated that the pretreatment of raw oil with acid was not required. The fatty acid content analysis confirmed that the contribution of unsaturated fatty acids in the BAO is high (84.7. wt.%). Effect of different parameters including methanol to oil molar ratio (3-11....