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shaygan--jalal
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Optimization of Operational Parameters for a Semi-continuous Compost Unit
, M.Sc. Thesis Sharif University of Technology ; Shayegan, Jalal (Supervisor) ; Kariminia, Hamid Reza (Co-Advisor) ; Yusofzadeh, Ahmad (Co-Advisor)
Abstract
The sudden increase in population growth rate in major cities and the recent changes in life style (consumerism) have resulted in a massive load of municipal solid waste. Managing this huge amount of waste imposes a heavy burden on municipalities’ shoulders. There are several options to Manage Solid waste, among them incineration and landfill are widely use in Managing municipal solid waste. Considering the fact that these two options are potentially hazardous to environment, high moisture content of municipal solid waste added, composting has become more trendy approach in last decades.Although composting is more environmentally friendly, it still needs the waste to be collected from all...
Modified CMC: part 1- optimized synthesis of carboxymethylcellulose-g-polyacrylonitrile [electronic resource]
, Article Iranian Polymer Journal ; Vol. 14, No 2, 131-138, 2005 ; Pourjavadi, A ; Sadeghi, M
Abstract
As the first part of a continued research on conversion of carboxymethyl cellulosesodium salt (CMC) to useful biopolymer-based materials, large numbers of cyanide functional groups were introduced onto CMC by grafting with polyacrylonitrile (PAN). The graft copolymerization reactions were carried out under nitrogen atmosphere using ceric ammonium nitrate (CAN) as an initiator. Evidence of grafting was obtained by comparing FTIR spectra of CMC and the graft copolymer as well as solubility characteristics of the products. The synthetic conditions were systematically optimized through studying the effective factors including temperature and concentrations of initiator, acrylonitrile monomer,...
New polysaccharide-g-polyacrylonitrile copolymers: synthesis and thermal characterization [electronic resource]
, Article Polymers for Advanced Technologies ; Volume 14, Issue 7, pages 508–516, July 2003 ; Pourjavadi, Ali ; Sharif University of Technology
Abstract
Various natural and modified polysaccharides (i.e. arabic gum, tragacanth gum, xanthan gum, sodium alginate, chitosan, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose) were modified using ceric-initiated graft polymerization of acrylonitrile under inert atmosphere. Grafting was confirmed using spectral (FT-IR) proofs. The grafting parameters were determined by conventional methods. Thermal characteristics of the homopolymer-free copolymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. The major thermal transitions as well as the activation energy of the major decomposition stages were...
A Novel Approach in DNA Sequencing Based on Physical Differences of Nucleotides
, M.Sc. Thesis Sharif University of Technology ; Nejat Pishkenari, Hossein (Supervisor) ; Meghdari, Ali (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
Abstract
With the continued improvement of sequencing technologies, the prospect of genome-based medicine is now at the forefront of scientific research. To realize this potential, however, a revolutionary sequencing method is needed for the cost-effective and rapid interrogation of individual genomes. Generally there are key factors in the definition and evalution of sequencing methods: 1-read length, 2-throughput, 3-read accuracy, 4-read depth, and 5-cost per base. The purpose of developing new sequencing methods is making better at least one of these factors. In order to reach the goal of rapid and low-cost sequencing method, one cannot rely only on current techniques. Improvements of current...
Optimization of the magnetic properties and microstructure of Co 2+-La3+ substituted strontium hexaferrite by varying the production parameters
, Article Ceramics International ; Vol. 40, issue. 4 , May , 2014 , pp. 5675-5680 ; ISSN: 02728842 ; Vahedi, A ; Nemati, A ; Noorbakhsh, M ; Mirsatari. S. N ; Shaygan, M ; Mackenzie, K. J. D ; Sharif University of Technology
2014
Abstract
The aim of this paper was to improve the magnetic properties of magnetoplumbite-type (M-type) strontium hexaferrite substituted with Co 2+-La3+ produced by conventional ceramic forming techniques. The effect on the magnetic properties of varying the composition of the target compound Sr1-xLaxFe12-yCo yO19 and the primary and secondary firing temperatures was investigated. Microstructure studies and XRD phase analysis indicated that optimum values of the remanent magnetization Br and coercive field Hcj were obtained with a primary firing temperature of 1240 C and a final firing temperature of 1180 C, where (x=y)th 1=0.15, (y/x)exp 2=0.75 and the molar ratio of ferric oxide to strontium...
Experimental Studies on Biodiesel Production Using Waste Frying Oil in a Hetergogeneous Catalytic Reaction
, M.Sc. Thesis Sharif University of Technology ; Kariminia, Hamid Reza (Supervisor) ; Shaygan Salek, Jalaloddin (Supervisor) ; Pazouki, Mohammad (Co-Advisor)
Abstract
Biodiesel can be a good alternative for fossil diesel since it isrenewable, biodegradable and non-toxic. Also, in comparison with fossil fuels, it emits less air pollutants and greenhouse gases.Findacost effective and environmentally friendly wayforcontinuousproductionofbiodieselcanaddressmany of our environmental concerns. In this study, we applied heterogeneous alkali-catalyzed transesterification as method and used waste frying oil as a low cost feedstock for biodiesel production. The project was performed in two phases. First, experiments were conducted in astirred reactor to finda suitable catalyst which was strontium carbonate calcinated for 3:24 hours in 975̊C.
RPB(rotating...
RPB(rotating...
Modified CMC.2. Novel carboxymethylcellulose-based poly (amidoxime) chelating resin with high metal sorbtion capacities [electronic resource]
, Article Reactive and Functional Polymers ; Volume 61, Issue 1, August 2004, Pages 23–31 ; Pourjavadi, A ; Sadeghi, M ; Sharif University of Technology
Abstract
Carboxymethylcellulose sodium salt (CMC) was doubly modified to prepare a novel poly(acrylamidoxime) chelating resin. Acrylonitrile was firstly graft polymerized onto CMC using cerium ammonium nitrate as an initiator. The polyacrylonitrile (PAN) grafted CMC was then amidoximized via treatment with hydroxylamine to prepare the ion exchange resin. The sorption capacity of the resin towards bivalent metal ions was evaluated while varying the pH, the loading of the PAN and the initial metal ion concentration. The adsorption kinetics were investigated for the cupric ion. The chelating resin exhibited very high metal sorption capacity in comparison with either synthetic or polysaccharide-based...
Oil-soluble drag-reducing polymers [electronic resource]
, Article Journal of polymer materials ; December 1994, Volume 11, Number 4; Page(s) 239 To 247 ; Pourjavadi, A ; Nadali, M ; Sharif University of Technology
Abstract
This article reviews the oil-soluble polymeric drag-reducing agents (DRAs) with an outlook to their large-scale application in petroleum industry. A general discussion on mechanism of the DR phenomenon and mechanical degradation of the drag reducers in turbulent flow is offered with an emphasis on the molecular parameters. Furthermore, low charge density associating polymers, as a new class of oil-soluble flow improvers, are described