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Synthesis and X-ray structural characterization of unsymmetrical tetradentate complexes of Ni(II) and Cu(II)
, Article Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry ; Volume 32, Issue 2 , 2002 , Pages 345-355 ; 00945714 (ISSN) ; Boghaei, D. M ; Sharif University of Technology
2002
Abstract
The unsymmetrical tetradentate Schiff base H2L was prepared by the reaction of salicylaldehyde with the mono Schiff base derived from o-phenylenediamine and o-hydroxyacetophenone (HL1). NiL and CuL complexes were prepared and characterized by 1H NMR, IR and single crystal X-ray structure determination. Crystal data for NiL: triclinic space group P-1, a = 7.190 (2) Å, b = 13.059 (4) Å, c = 17.867 (10) Å, α = 74.888 (10)°, β = 84.206 (10)°, γ = 86.542 (2)° and z = 4. Crystal data for CuL: monoclinic space group P2I/n, a = 12.8209 (6) Å, b = 6.988 (3) Å, c = 18.601 (9) Å, β = 105.15° and z = 4. The Ni and Cu atoms have a slightly distorted square-planar coordination geometry
Development of Microorganisms with Improved Biosurfactant Activity
, Ph.D. Dissertation Sharif University of Technology ; Roosta Azad, Reza (Supervisor) ; Rouholamini Najafabadi, Abdolhossein (Supervisor) ; Akbari Noghabi, Kambiz (Co-Advisor) ; Shahcheraghi, Fereshte (Co-Advisor)
Abstract
This thesis discusses the work on the production of a rhamnolipid-type biosurfactant by Pseudomonas aeruginosa MR01, its structural characterization and environmental applications. First, results from analytical approaches for screening of biosurfactant producers suggested the oil spreading method as the fastest, simplest and most consistent analytical method. The second part of the thesis describes the properties of the most efficient biosurfactant-producing bacteria isolated from oil fields in south of Iran and according to it’s biochemical characteristics and partial sequenced 16S rRNA gene affiliated with Pseudomonas aeruginosa. Time course study indicated that the maximum biosurfactant...
Experimental design in analytical chemistry - Part II: Applications
, Article Journal of AOAC International ; Vol. 97, issue. 1 , 2014 , p. 12-18 ; Leardi, R ; Jalali-Heravi, M ; Sharif University of Technology
Abstract
This paper reviews the applications of experimental design to optimize some analytical chemistry techniques such as extraction, chromatography separation, capillary electrophoresis, spectroscopy, and electroanalytical methods
A conically fixed position single drop microextraction method for isolation of aryloxyphenoxypropionate herbicides from aquatic media
, Article Analytical Methods ; Volume 5, Issue 18 , Jul , 2013 , Pages 4846-4851 ; 17599660 (ISSN) ; Dehghan, M ; Es'Haghi, A ; Naderi, M ; Sharif University of Technology
2013
Abstract
A new and convenient format of single drop microextraction (SDME) was developed and applied for isolation of some selected aryloxyphenoxypropionate herbicides from aquatic media. In contrast to the conventional SDME procedure, in this set-up the extraction microdrop was positioned at the bottom of a conical vial in order to provide much higher stability for the organic extraction phase while a magnetic bar was used for stirring the aqueous solution. A simple magnet was used for positioning the bar on the top of the microdrop prior to stirring. The whole set-up led to the use of any volume of extraction solvent with unlimited stirring rates. Some important extraction parameters such as the...
Efficient batch-mode mixing and flow patterns in a microfluidic centrifugal platform: a numerical and experimental study
, Article Microsystem Technologies ; 2016 , Pages 1-13 ; 09467076 (ISSN) ; Tirandazi, P ; Normandie, M ; Saidi, M. S ; Sharif University of Technology
Springer Verlag
Abstract
During recent years centrifugal-based microfluidic devices known as Lab-on-a-CD have attracted a lot of attentions. Applications of these CD-based platforms are ubiquitous in numerous biological analyses and chemical syntheses. Mixing of different species in microscale is one of the essential operations in biochemical applications where this seemingly simple task remains a major obstruction. Application of centrifugal force, however, may significantly improve the flow agitation and mixing, especially when it is combined with the Coriolis force which acts perpendicular to centrifugal force. In this study, mixing process in minichambers located on a rotating platform under a periodic...
Manufacturing of hydrogel biomaterials with controlled mechanical properties for tissue engineering applications
, Article Acta Biomaterialia ; Volume 62 , 2017 , Pages 42-63 ; 17427061 (ISSN) ; Minooei, F ; Mohammadi, M. H ; Khetani, S ; Rezaei Kolahchi, A ; Mashayekhan, S ; Sanati Nezhad, A ; Sharif University of Technology
Abstract
Hydrogels have been recognized as crucial biomaterials in the field of tissue engineering, regenerative medicine, and drug delivery applications due to their specific characteristics. These biomaterials benefit from retaining a large amount of water, effective mass transfer, similarity to natural tissues and the ability to form different shapes. However, having relatively poor mechanical properties is a limiting factor associated with hydrogel biomaterials. Controlling the biomechanical properties of hydrogels is of paramount importance. In this work, firstly, mechanical characteristics of hydrogels and methods employed for characterizing these properties are explored. Subsequently, the most...
Efficient batch-mode mixing and flow patterns in a microfluidic centrifugal platform: a numerical and experimental study
, Article Microsystem Technologies ; Volume 23, Issue 7 , 2017 , Pages 2767-2779 ; 09467076 (ISSN) ; Tirandazi, P ; Normandie, M ; Saidi, M. S ; Sharif University of Technology
Abstract
During recent years centrifugal-based microfluidic devices known as Lab-on-a-CD have attracted a lot of attentions. Applications of these CD-based platforms are ubiquitous in numerous biological analyses and chemical syntheses. Mixing of different species in microscale is one of the essential operations in biochemical applications where this seemingly simple task remains a major obstruction. Application of centrifugal force, however, may significantly improve the flow agitation and mixing, especially when it is combined with the Coriolis force which acts perpendicular to centrifugal force. In this study, mixing process in minichambers located on a rotating platform under a periodic...
Practical properties and formaldehyde emission of medium density fiberboards (MDFs) recycled by electrical method
, Article European Journal of Wood and Wood Products ; Volume 76, Issue 4 , 2018 , Pages 1287-1294 ; 00183768 (ISSN) ; Abdolkhani, A ; Doost hoseini, K ; Ramazani Saadat Abadi , A ; Tarmian, A ; Sharif University of Technology
Springer Verlag
2018
Abstract
In this study, the performance of the electrical method in MDF wastes recycling was determined. For investigating the practical aspect of the electrical method, the hydrothermal method as a known recycling method was studied too. The recycling process by electrical method conducted for two different time durations (2 and 4 min) at a temperature of 100 °C and recycling using the hydrothermal method was done at a temperature of 105 °C for 150 min under 4 bar pressure with subsequent refining step. Recycled fibers were analyzed by determination of the chemical composition of fibers and fiber classification. After that, laboratory MDF boards with dimensions of 35 × 35 × 12 mm3 and density of...
Iron-catalyzed inexpensive and practical synthesis of N-substituted pyrroles in water
, Article Synlett ; Issue 14 , 2009 , Pages 2245-2248 ; 09365214 (ISSN) ; Khajeh Amiri, A ; Ghafuri, H ; Bolourtchian, M ; Saidi, M. R ; Sharif University of Technology
2009
Abstract
An operationally simple, practical, and economical protocol for iron(III) chloride catalyzed Paal-Knorr pyrrole synthesis in water in good to excellent yields has been developed. Several N-substituted pyrroles are readily prepared from the reaction of 2,5-dimethoxytetrahydrofuran and aryl/alkyl, sulfonyl and acyl amines under very mild reaction conditions. © Georg Thieme Verlag Stuttgart
Semi-automatic context-aware composition of semantic Web services
, Article 2nd International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies, UBICOMM 2008, Valencia, 29 September 2008 through 4 October 2008 ; 2008 , Pages 502-509 ; 9780769533674 (ISBN) ; Orang, M ; Abolhassani, H ; Sharif University of Technology
2008
Abstract
In many cases, atomic Semantic Web services are not able to provide requested functionalities. Therefore, in order to satisfy users' requests, the composition task is required on available atomic services. In addition, Context awareness in Web services is gaining momentum as the opportunity to benefit the interactions between human, applications and the environment. So it seems reasonable to use available context information in composition procedure to provide a composite Semantic Web service which is adapted to the context of participant Web services and the requester. In this paper, we introduce a novel approach for semi-automatic context-aware graph-based composition of Semantic Web...
Oxidation of aldehydes and ketones into carboxylic acids and esters using 4-amino-2-chloroperbenzoic acid supported on silica gel
, Article Synthetic Communications ; Volume 35, Issue 8 , 2005 , Pages 1103-1107 ; 00397911 (ISSN) ; Ghazanfari, D ; Ahmadibeni, Y ; Karimi Jaberi, Z ; Ezabadi, A ; Sharif University of Technology
2005
Abstract
4-Amino-2-chloroperbenzoic acid supported on silica gel was found to be a versatile and efficient oxidant for the oxidation of aldehydes and ketones to the corresponding carboxylic acids and esters. Copyright © Taylor & Francis, Inc
The influence of surface nanocrystallization induced by shot peening on corrosion behavior of niti alloy
, Article Journal of Materials Engineering and Performance ; Volume 24, Issue 8 , August , 2015 , Pages 3093-3099 ; 10599495 (ISSN) ; Sadrnezhaad, S. K ; Atai, M ; Sharif University of Technology
Springer New York LLC
2015
Abstract
Nickel-titanium (NiTi) shape memory alloys have been widely used as implant materials, due to their superior shape memory properties and similar mechanical behavior to bone tissue. The presence of nickel on the surface of nickel-titanium alloy and release of this ion in the body environment will result in some allergic reactions. In current study, we used shot pinning process to produce nanocrystalline nickel-titanium alloy with increased corrosion resistance. Field emission scanning electron microscopy (FE-SEM), x-ray diffraction (XRD) analysis, and atomic force microscopy were employed to investigate the surface features of samples. The quantitative chemical analysis of NiTi and modified...
Facile synthesis of highly substituted 2-pyrone derivatives via a tandem Knoevenagel condensation/lactonization reaction of β-formyl-esters and 1,3-cyclohexadiones
, Article Tetrahedron Letters ; Vol. 55, issue. 18 , April , 2014 , p. 2908-2911 ; ISSN: 00404039 ; Mirjafary, Z ; Javan, M. J ; Motamen, S ; Saeidian, H ; Sharif University of Technology
Abstract
A mild and efficient tandem process for the synthesis of new highly substituted 2-pyrones starting from commercially available 2-arylacetic acids has been developed. The synthesis is based on the Knoevenagel condensation of 1,3-cyclohexadiones with various β-formyl-esters, followed by lactonization in the presence of nano ZnO (20 mol %). Moderate to high yields and readily available cheap starting materials are the key features of the present method
Experimental design in analytical chemistry -Part I: Theory
, Article Journal of AOAC International ; Vol. 97, issue. 1 , 2014 , pp. 3-11 ; ISSN: 10603271 ; Leardi, R ; Jalali-Heravi, M ; Sharif University of Technology
Abstract
This paper reviews the main concepts of experimental design applicable to the optimization of analytical chemistry techniques. The critical steps and tools for screening, including Plackett-Burman, factorial and fractional factorial designs, and response surface methodology such as central composite, Box-Behnken, and Doehlert designs, are discussed. Some useful routines are also presented for performing the procedures
Failure analysis: Sulfide stress corrosion cracking and hydrogen-induced cracking of A216-WCC wellhead flow control valve body
, Article Journal of Failure Analysis and Prevention ; Vol. 14, issue. 3 , 2014 , p. 376-383 ; Kokabi A.H ; Mostowfi J ; Sharif University of Technology
Abstract
The wellhead flow control valve bodies which are the focal point of this failure case study were installed in some of the upstream facilities of Khangiran's sour gas wells. These valve bodies have been operating satisfactorily for 3 years in wet H2S environment before some pits and cracks were detected in all of them during the periodical technical inspections. One failed valve body was investigated by chemical and microstructural analytical techniques to find out the failure cause and provide preventive measures. The valve body alloy was A216-WCC cast carbon steel. During investigation many cracks were observed on the inner surface of the valve body grown from the surface pits. The results...
A metabonomics investigation of multiple sclerosis by nuclear magnetic resonance
, Article Magnetic Resonance in Chemistry ; Volume 51, Issue 2 , DEC , 2013 , Pages 102-109 ; 07491581 (ISSN) ; Kyani, A ; Tafazzoli, M ; Fathi, F ; Joghataie, M. T ; Sharif University of Technology
2013
Abstract
Multiple sclerosis (MS) is a nervous system disease that affects the fatty myelin sheaths around the axons of the brain and spinal cord, leading to demyelination and a broad range of signs and symptoms. MS can be difficult to diagnose because its signs and symptoms may be similar to other medical problems. To find out which metabolites in serum are effective for the diagnosis of MS, we utilized metabolic profiling using proton nuclear magnetic resonance spectroscopy (1H-NMR). Random forest (RF) was used to classify the MS patients and healthy subjects. Atomic absorption spectroscopy was used to measure the serum levels of selenium. The results showed that the levels of selenium were lower in...
Copper(II) acetate
, Article Synlett ; Volume 23, Issue 13 , 2012 , Pages 1995-1996 ; 09365214 (ISSN) ; Sharif University of Technology
2012
Abstract
(A) Chakraborty and co-workers have developed a green method for the bulk ring-opening polymerization of lactides in the presence of Cu(OAc)2 as a good catalyst to synthesize polymers with different end-terminal groups.3 These polymerizations are highly controlled leading to the formation of polymers with the expected number of average molecular weights and narrow molecular weight distribution. (B) Garden and co-workers have found that the oxidative addition of anilines with 1,4-naphthoquinone to give N-aryl-2-amino-1,4-naphthoquinones can be performed in the presence of catalytic amounts of copper(II) acetate.4 All the reactions are generally more efficient in that they are cleaner, higher...
Investigation of the Shaft Failure Connected to Extruder
, Article Journal of Failure Analysis and Prevention ; Volume 15, Issue 6 , 2015 , Pages 775-781 ; 15477029 (ISSN) ; Mashayekhi, F ; Movahedi-Rad, A ; Sharif University of Technology
Springer New York LLC
2015
Abstract
In this study, the failure analysis of a shaft of a unit, which had been failed during the service, was studied. This shaft was welded to the blades, and their chemical compositions were determined by spectroscopy method. In order to determine the root cause of failure and contribution factors, different investigation methods including visual examination, optical microscopy and scanning electron microscope analysis, and hardness test were carried out. It was concluded that the shaft was failed due to fatigue. The failure was caused by improper welding of blades to the shaft. At the end, in order to prevent or decelerate such failure, some recommended remedies were suggested
Supercritical synthesis and characterization of graphene-pbs quantum dots composite with enhanced photovoltaic properties
, Article Industrial and Engineering Chemistry Research ; Volume 54, Issue 30 , 2015 , Pages 7382-7392 ; 08885885 (ISSN) ; Tavakoli, M. M ; Outokesh, M ; Shafiekhani, A ; Simchi, A ; Sharif University of Technology
American Chemical Society
2015
Abstract
Lead sulfide quantum dots (PbS QDs) were decorated onto a graphene surface in a semi-core-shell structure using supercritical ethanol. The temperature of ethanol played significant role in controlling size and agglomeration of QDs as well as the extent of reduction of graphene. Average size of the QDs was estimated by transmission electron microscopy to be around 3.96 nm and by quantum models to be about 4.34 nm. PbS QDs prepared at 330 °C were of high purity, and the yield was 99%. Instrumental and chemical analyses demonstrated formation of a strong bond between PbS QDs and graphene, through a Pb-O-C bridge. UV and photoluminescence measurements along with theoretical considerations...
H2S gasochromic effect of mixed ammonium salts of phosphomolybdate nanoparticles synthesized by microwave assisted technique
, Article Sensors and Actuators, B: Chemical ; Volume 237 , 2016 , Pages 715-723 ; 09254005 (ISSN) ; Iraji zad, A ; Tadjarodi, A ; Sharif University of Technology
Elsevier B.V
2016
Abstract
In the present paper, new H2S gasochromic nanomaterial of mixed silver nickel ammonium phosphomolybdate synthesized by microwave assisted technique is reported. The microwave treatment was performed in the solid phase using urea and ammonium nitrate as the promoter and oxidizer agents. The designed process allows rapid synthesis of large amounts of this product in nanosized particulate morphology. Morphological and structural features of the prepared products were studied in detail. Chemical analyses indicated a stoichiometry of (NH4)0.5Ni0.75AgPMo12O40·4H2O revealing a Keggin-type framework with substitution of silver and nickel cations in its secondary structure. A home-made set-up was...