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Design and Construction of Copper Bromide Laser
, M.Sc. Thesis Sharif University of Technology ; Saddighi Bonabi, Rasoul (Supervisor)
Abstract
In this work, design and construction of copper vapor and Cu Br laser is explained. By special design of copper electrodes the average power from Cu laser system was increased more than 20% in comparison to the same system with expensive electrodes made from molybdenum. However, the basic goal of this work was the construction of CuBr laser. Based on the home made fast trigger unit for Hydrogen thyratron, operation of the manufactured system was possible up to 25 kHz. By using special designed copper electrodes very uniform operation of CuBr plasma diluted in Ne gas was observed. By tuning of the laser parameters such as gas pressure, exciting voltage and pulse repetition rate, from 9 Cm3 of...
Design and Fabrication of Optimumhalide Copper Vapour Lasers
,
M.Sc. Thesis
Sharif University of Technology
;
Sadighi Bonabi, Rasoul
(Supervisor)
Energy and Economic Analysis of Micro CHP Systems in Buildings
, M.Sc. Thesis Sharif University of Technology ; Sattari, Sourena (Supervisor)
Abstract
In recent decades, due to economic, political and environmental issues, tend to use of the CHP systems (combined heating and power) have increased. CHP systems not only increase energy efficiency, but also decrease fuel consumption and emission levels of systems. The use of CHP technology in the industry has a long history, but the use of these systems in the commercial and residential sector, is considered, recently. As to the residential buildings, both electricity and thermal energy demands fluctuate seasonally and hourly, so it is necessary to take account of the plant’s annual operational strategies for the variations of load demands. In this paper, a nonlinear programming model is...
Toward chemical perfection of graphene-based gene carrier via ugi multicomponent assembly process
, Article Biomacromolecules ; Volume 17, Issue 9 , 2016 , Pages 2963-2971 ; 15257797 (ISSN) ; Akhavan, O ; Hashemi, E ; Shamsara, M ; Sharif University of Technology
American Chemical Society
Abstract
The graphene-based materials with unique, versatile, and tunable properties have brought new opportunities for the leading edge of advanced nanobiotechnology. In this regard, the use of graphene in gene delivery applications is still at early stages. In this study, we successfully designed a new complex of carboxylated-graphene (G-COOH) with ethidium bromide (EtBr) and used it as a nanovector for efficient gene delivery into the AGS cells. G-COOH, with carboxyl functions on its surface, in the presence of EtBr, formaldehyde, and cyclohexylisocyanide were participated in Ugi four component reaction to fabricate a stable amphiphilic graphene-EtBr (AG-EtBr) composite. The coupling reaction was...
The synergic effects of anionic and cationic chemical surfactants, and bacterial solution on wettability alteration of carbonate rock: an experimental investigation
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 513 , 2017 , Pages 422-429 ; 09277757 (ISSN) ; Lashkarbolooki, M ; Ayatollahi, S ; Hashemi, A ; Sharif University of Technology
Abstract
Changing the wettability of reservoir rock towards strongly water-wet state is effective way to enhance oil recovery from fractured carbonate reservoirs which are typically oil-wet. Regarding this fact, the injection of surfactant and the bacterial solution as EOR agents is proposed in the current work as a potential method to alter the wettability of rock surface reservoir. Nevertheless, there is a definite lack of experimental data regarding this method and the synergistic effect of both chemical and bacterial solutions on this process. In this study, the sole and combined effects of the bacterial solution using an Enterobacter cloacae strain as a biosurfactant-producer are compared with...
The first report on the catalytic oxidation of urazoles to their corresponding triazolinediones via in situ catalytic generation of Br+ using periodic acid or oxone®/KBr system
, Article Journal of Molecular Catalysis A: Chemical ; Volume 270, Issue 1-2 , 2007 , Pages 219-224 ; 13811169 (ISSN) ; Bagherzadeh, M ; Mallakpour, S ; Chehardoli, G ; Ghorbani Choghamarani, A ; Koukabi, N ; Dehghanian, M ; Doroudgar, M ; Sharif University of Technology
2007
Abstract
A combination of periodic acid or oxone® and a catalytic amount of KBr in the presence of few drops of water, were used for the catalytic oxidation of urazoles and bis-urazoles to their corresponding triazolinediones under mild and heterogeneous conditions with moderate to excellent yields. © 2007 Elsevier B.V. All rights reserved
Template-directed hydrothermal synthesis of dandelion-like hydroxyapatite in the presence of cetyltrimethylammonium bromide and polyethylene glycol
, Article Ceramics International ; Volume 35, Issue 7 , 2009 , Pages 2563-2569 ; 02728842 (ISSN) ; Solati Hashjin, M ; Shafiei, S. S ; Salarian, R ; Nemati, Z. A ; Sharif University of Technology
2009
Abstract
A template-directed synthetic method, using surfactant cetyltrimethylammonium bromide (CTAB) as a template and co-surfactant polyethylene glycol (PEG600) as a co-template under hydrothermal conditions, has been applied to obtain dandelion-like HAp. The morphology, size, crystalline phase, chemical composition, physical characteristics, and thermal behavior of the product were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier ransform infrared spectroscopy (FTIR), induced coupled plasma spectroscopy (ICP), BET (Brunauer, Emmett, and Teller) method, and simultaneous thermal analysis (STA). SEM and TEM...
Synthesis of new hybrid nanomaterials: Promising systems for cancer therapy
, Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 7, Issue 6 , 2011 , Pages 806-817 ; 15499634 (ISSN) ; Kalantari, M ; Parsamanesh, M ; Sadeghi, E ; Mahmoudi, M ; Sharif University of Technology
2011
Abstract
Polyrotaxanes consisting of cyclodextrin rings, polyethylene glycol axes and quantum dot (QD) stoppers were synthesized and characterized. The molecular self-assembly of polyrotaxanes led to spindlelike nano-objects whose shape, size and position were dominated by QD stoppers. Due to their well-defined molecular self-assemblies, carbohydrate backbone, high functionality and several types of functional groups together with the high luminescence yield, synthesized hybrid nanostructures were recognized as promising candidates for biomedical applications. The potential applications of the molecular self-assemblies as drug-delivery systems was investigated by conjugation of doxorubicin (DOX) to...
Surfactant-assisted synthesis and characterization of hydroxyapatite nanorods under hydrothermal conditions
, Article Materials Science- Poland ; Volume 27, Issue 4 , 2009 , Pages 961-971 ; 01371339 (ISSN) ; Solati Hashjin, M ; Sara Shafiei, S ; Goudarzi, A ; Salarian, R ; Nemati, A ; Sharif University of Technology
2009
Abstract
Hydroxyapatite (HAp) nanorods with uniform morphology and controllable size were successfully synthesized by precipitating Ca(NO3) 24H2O and (NH4)2HPO4 in the presence of cetyltrimethylammonium bromide (CTAB) and polyethylene glycol 400 (PEG 400) as cationic surfactant and non-ionic cosurfactant, respectively, under hydrothermal conditions. The effect of hydrothermal temperature on the composition, morphology and size of HAp particles was studied using X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM). Results revealed that the morphology and size of HAp particles can be effectively controlled by the presence of CTAB and PEG...
Rheology, stability and filtration characteristics of colloidal gas aphron fluids: role of surfactant and polymer type
, Article Journal of Natural Gas Science and Engineering ; Volume 26 , September , 2015 , Pages 895-906 ; 18755100 (ISSN) ; Arabloo, M ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier
2015
Abstract
Colloidal Gas Aphron (CGA) are finding increasing application in fields of science and engineering because of their distinctive characteristic. As interest in the application of CGA based fluids grows and in order to select the best procedure for using them in successful petroleum engineering operations, there is a need to gain a better understanding of the factors that affect their properties and behavior. This article discusses the rheological characterization, stability analysis and filtration properties of CGA based fluids for three bio-polymers and two ionic surfactant. The stability and filtration analysis were investigated with the static drain rate technique and API filtration tests,...
Reinforced polydiphenylamine nanocomposite for microextraction in packed syringe of various pesticides
, Article Journal of Chromatography A ; Volume 1222 , January , 2012 , Pages 13-21 ; 00219673 (ISSN) ; Ayazi, Z ; Es'haghi, A ; Aghakhani, A ; Sharif University of Technology
2012
Abstract
Reinforced polydiphenylamine (PDPA) nanocomposite was synthesized by oxidation of diphenylamine in 4molL-1 sulfuric acid solution containing a fixed amount of carbon nanotubes (CNTs) in the presence of cetyltrimethylammonium bromide (CTAB). The surface characteristic of PDPA and PDPA/CNT nanocomposites was investigated using scanning electron microscopy (SEM). The prepared PDPA/CNT nanocomposite was used as an extraction medium for microextraction in packed syringe (MEPS) of selected pesticides from aquatic environment. The effect of CNT doping level and the presence of surfactant on the extraction capability of nanocomposite was investigated and it was revealed that when 4% (w/w) of CNT in...
Preparation and biological evaluation of radiolabeled-folate embedded superparamagnetic nanoparticles in wild-type rats
, Article Journal of Radioanalytical and Nuclear Chemistry ; Volume 287, Issue 1 , January , 2011 , Pages 119-127 ; 02365731 (ISSN) ; Hosseini Salekdeh, S. L ; Mahmoudi, M ; Yousefnia, H ; Majdabadi, A ; Pouladian, M ; Sharif University of Technology
2011
Abstract
In this study, superparamagnetic iron oxide nanoparticles (SPION) embedded by folic acid (SPION-folate) were prepared by a modified co-precipitation method. The structure, size, morphology, magnetic property and relaxivity of the SPION-folate were characterized systematically by means of XRD, VSM, HRSEM and TEM and the interaction between folate and iron oxide (Fe3O 4) was characterized by FT-IR. The particle size was shown to be ≈5-10 nm. To ensure biocompatibility, the interaction of these SPION with mouse connective tissue cells (adhesive) was investigated using an MTT assay. Consequently, gallium-67 labeled nanoparticles ([67Ga]-SPION-folate) were prepared using 67Ga with a high labeling...
Preconcentration and determination of pantoprazole by solid-phase extraction coupled with spectrophotometry using iron oxide nanoparticles modified with cetyltrimethylammonium bromide
, Article Nano Biomedicine and Engineering ; Volume 7, Issue 3 , 2015 , Pages 102-110 ; 21505578 (ISSN) ; Naghian, E ; Sahebi, H ; Asgari, S ; Sharif University of Technology
Open Access House of Science and Technology
2015
Abstract
Solid phase extraction coupled with spectrophotometric detection was applied to trace amounts of Pantoprazole (PP) drug using Cetyltrimethylammonium bromide coated-iron oxide magnetite nanoparticles CTAB@Fe3O4 MNPs. After characterization of the prepared nano-adsorbents, experimental parameters affecting the extraction efficiency of the developed method were optimized. The results obtained showed that this proposed approach is applicable in concentrations ranging from 0.1 to 1.5 μg/ml (R2 = 0.9958) indicating that follows Beer's-Lambert law. The limit of detection and the limit of quantification calculated to be 0.014 and 0.04 μg/ml, respectively. The repeatability of the proposed method was...
Polypyrrole nanowires network for convenient and highly efficient microextraction in packed syringe
, Article Analytical Methods ; Volume 3, Issue 11 , 2011 , Pages 2630-2636 ; 17599660 (ISSN) ; Ayazi, Z ; Sharif University of Technology
Abstract
A novel method based on microextraction in packed syringe (MEPS), as a sample preparation technique in combination with gas chromatography-mass spectrometry (GC-MS) was developed using a polypyrrole (PPy) nanowires network as the extracting medium. The PPy nanowires network was prepared using a soft template technique and its characterization was studied by scanning electron microscopy (SEM). The use of micelles in this methodology has an important role in the shape of the growing polymer. The pyrrole monomer was introduced into cetyltrimethylammonium bromide (CTAB) micelles and this has led to the formation of nanowires with diameters ranging from 30 to 60 nm. The bulk PPy prepared without...
Polymeric ionic liquid nanogel-anchored tungstate anions: A robust catalytic system for oxidation of sulfides to sulfoxides
, Article New Journal of Chemistry ; Volume 39, Issue 2 , 2015 , Pages 1348-1354 ; 11440546 (ISSN) ; Nazari Chamazkoti, M ; Hosseini, S. H ; Sharif University of Technology
Abstract
A new heterogeneous catalytic system was prepared by immobilization of tungstate ions on a cross-linked poly(ionic liquid) nanogel. The solid nanogel was easily synthesized by a surfactant-less method. The resulting catalyst was highly active in selective oxidation of sulfides to sulfoxides by H2O2. The oxidation reactions were successfully performed under solvent-free conditions affording high yields. The catalyst was recycled and reused for several reaction cycles without any significant loss of catalytic activity
Numerical modeling of incline plate LiBr absorber
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 47, Issue 3 , November , 2011 , Pages 259-267 ; 09477411 (ISSN) ; Farhanieh, B ; Sharif University of Technology
2011
Abstract
Among major components of LiBr-H 2O absorption chillers is the absorber, which has a direct effect on the chillier size and whose characteristics have significant effects on the overall efficiency of absorption machines. In this article, heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water-cooled incline plate absorber in the Reynolds number range of 5
Michael-Addition-Initiated chemoselective three-component reaction for the synthesis of 2-(3-Oxo-1,3-diarylpropyl)malononitrile derivatives using cerium(IV) ammonium nitrate in phosphorus ionic liquid
, Article Polycyclic Aromatic Compounds ; Volume 42, Issue 9 , 2022 , Pages 6328-6336 ; 10406638 (ISSN) ; Batooie, N ; Mousavi, S. R ; Miraghaee, S. S ; Hosseinzadeh, N ; Mousavian, S ; Hoshyari, A ; Sajadimajd, S ; Mohammadi, B ; Hatami, R ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
The aim of this research is the study of hexyltriphenylphosphonium bromide (HTPB) ionic liquid as a bifunctional promoter (solvent and catalyst) in the presence of cerium(IV) ammonium nitrate as a single electron oxidant for the Michael reaction at room temperature and solvent-free conditions. A novel, one-pot and environmentally benign the process to achieve the chemoselective of 2-(3-oxo-1,3-diarylpropyl)malononitrile derivatives instead of 2-(1,3-diarylallylidene)malononitriles using a three-component reaction involving acetophenone derivatives, various aromatic aldehydes and malononitrile was developed. This protocol is simple and provides biologically interesting products in good...
Michael-addition-initiated chemoselective three-component reaction for the synthesis of 2-(3-oxo-1,3-diarylpropyl)malononitrile derivatives using cerium(iv) ammonium nitrate in phosphorus ionic liquid
, Article Polycyclic Aromatic Compounds ; 2021 ; 10406638 (ISSN) ; Batooie, N ; Mousavi, R ; Miraghaee, S ; Hosseinzadeh, N ; Mousavian, M ; Hoshyari, A ; Sajadimajd, S ; Mohammadi, B ; Hatami, R ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
The aim of this research is the study of hexyltriphenylphosphonium bromide (HTPB) ionic liquid as a bifunctional promoter (solvent and catalyst) in the presence of cerium(IV) ammonium nitrate as a single electron oxidant for the Michael reaction at room temperature and solvent-free conditions. A novel, one-pot and environmentally benign the process to achieve the chemoselective of 2-(3-oxo-1,3-diarylpropyl)malononitrile derivatives instead of 2-(1,3-diarylallylidene)malononitriles using a three-component reaction involving acetophenone derivatives, various aromatic aldehydes and malononitrile was developed. This protocol is simple and provides biologically interesting products in good...
Layered ruddlesden–popper perovskites with various thicknesses for stable solid-state solar cells
, Article Physics of the Solid State ; Volume 62, Issue 3 , 2020 , Pages 529-541 ; Abdizadeh, H ; Mirhosseini, M ; Taghavinia, N ; Sharif University of Technology
Pleiades Publishing
2020
Abstract
Abstract: The present research comes up with optimizing the layers thickness of a Ruddlesden–Popper perovskite with the general formula of (S0.97S0.03 ')2[Cs0.05(FA0.097MA0.03)0.95]n – 1Pbn(I0.97Br0.03)3n + 1 for efficient, stable solar cell applications. Such a triple-cation quasi-two-dimensional (2D) structure simultaneously contains two spacers, namely 5-ammonium valeric acid iodide (S) and tetra-n-octylammonium bromide (S'). Systematic studies showed that morphology, crystal structure, optical properties, photovoltaic performance, and internal resistances of this compound depended upon the value of the n integer. Field emission scanning electron microscopy set forth that the deposited...
Hydrothermal synthesis of aligned Hydroxyapatite nanorods with ultra-high crystallinity
, Article International Journal of Engineering, Transactions B: Applications ; Volume 21, Issue 2 , 2008 , Pages 109-116 ; 1728-144X (ISSN) ; Rahimipour, M. R ; Yazdani, B ; Sadrnezhaad, S. K ; Amin, M. H ; Sharif University of Technology
Materials and Energy Research Center
2008
Abstract
Hydroxyapatite nanorods aligned with ultrahigh crystallinity and high-yield were successfully synthesized through a hydrothermal approach. In this experiment, a new composition of cetyltrimethylammonium bromide ((CH 3(CH2)15N+(CH3) 3Br-) was designated as CTAP)/Ca(NO3) 2/ (NH4)2HPO4/NaOH and distilled water under hydrothermal condition, to synthesize single crystal HAp nanorods with diameter of 20 ± 10 nm and length of 80 ± 20 nm, was introduced. Crystal phases were determined by X-ray diffraction (XRD). Scanning electron microscope (SEM) was applied to investigate the morphology. The microstructure of the HAp products were further observed by transmission electron microscope (TEM) and high...