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A linear algebraic approach to orthogonal arrays and Latin squares
, Article Ars Combinatoria ; Volume 105 , 2012 , Pages 3-13 ; 03817032 (ISSN) ; Mahdian, M ; Mahmoodian, E. S ; Sharif University of Technology
2012
Abstract
To study orthogonal arrays and signed orthogonal arrays, Ray-Chaudhuri and Singhi (1988 and 1994) considered some module spaces. Here, using a linear algebraic approach we define an inclusion matrix and find its rank. In the special case of Latin squares we show that there is a straightforward algorithm for generating a basis for this matrix using the so-called intercalates. We also extend this last idea. Copyright
On the chromatic number of Latin square graphs
, Article Discrete Mathematics ; Volume 339, Issue 11 , 2016 , Pages 2613-2619 ; 0012365X (ISSN) ; Goddyn, L ; Mahmoodian, E. S ; Mortezaeefar, M ; Sharif University of Technology
Elsevier
Abstract
The chromatic number of a Latin square is the least number of partial transversals which cover its cells. This is just the chromatic number of its associated Latin square graph. Although Latin square graphs have been widely studied as strongly regular graphs, their chromatic numbers appear to be unexplored. We determine the chromatic number of a circulant Latin square, and find bounds for some other classes of Latin squares. With a computer, we find the chromatic number for all main classes of Latin squares of order at most eight
Optimization of the Solvent Extraction of Rhenium from Acidic Solution Produced by Pressure Leaching of Molybdenite Concentrate
, M.Sc. Thesis Sharif University of Technology ; Yoozbashizadeh, Hossein (Supervisor)
Abstract
The extraction of molybdenum and rhenium from acidic solution produced by pressure leaching of molybdenite concentrate, using organophosphorus solvents has been investigated. First, extraction of molybdenum by Di-2-EthyHexyl Phosphoric Acid (D2EHPA) extractant dissolved in kerosene diluents was done. Extraction experiments were designed using Taguchi L16b orthogonal array. The effects of four factors: Shaking time, Organic solvent concentration, Organic to aqueous phase ratio, pH were studied in four levels. Optimum conditions occur at: shaking time: 35 min, organic solvent concentration: 30 volumetric percent, organic to aqueous phase ratio: 3, pH: 7 and molybdenum is completely extracted....
Exploring and Constructing Multipartite Entangled States
, Ph.D. Dissertation Sharif University of Technology ; Karimipour, Vahid (Supervisor) ; Memarzadeh, Laleh (Co-Advisor)
Abstract
Entanglement is considered to be one of the characteristic traits of quantum mechanics. Besides it plays a key role in quantum information science, being a resource for most of its applications such as quantum communication and quantum computation. The characterization (of different forms) of entanglement and its quantification play a central role in developing entanglement theory. By considering this fact, we describe a method for finding polynomial invariants under LOCC for a system of delocalized fermions shared between different parties, with global particle-number conservation as the only constraint. These invariants can be used to construct entanglement measures for different types of...
Investigation of ultrasonic-assisted drilling of Al/SiC metal matrix composite with Taguchi method
, Article Key Engineering Materials ; Volume 523-524 , 2012 , Pages 215-219 ; 10139826 (ISSN) ; 9783037855096 (ISBN) ; Akbari, J ; Yousefi, R ; Sharif University of Technology
2012
Abstract
Burr in drilling plays an important role on product quality, so analysis the burr height is essential at the final production. This paper presents the application of Taguchi method for survey the burr height by adding ultrasonic vibration to the process. In this paper L18 orthogonal array based on Taguchi techniques was used in the design of experiments. Analysis of Variance (ANOVA) was used to determination the effect of drilling parameter on burr formation. Influence of spindle speed, feed rate and percentage of SiC particle was investigated in with and without ultrasonic assisted drilling. In this paper drilling of Al/SiCp MMCs with 5, 15 and 20 wt% of particulate SiC in dry drilling...
High temperature synthesis of SAPO-34: applying an L9 taguchi orthogonal design to investigate the effects of experimental parameters
, Article Powder Technology ; Volume 217 , February , 2012 , Pages 223-230 ; 00325910 (ISSN) ; Kazemian, H ; Soltanieh, M ; Hosseinpour, M ; Rohani, S ; Sharif University of Technology
Abstract
SAPO-34 zeolite-like particles were successfully synthesized at high temperature environment. An L9 orthogonal array of the Taguchi method was implemented to investigate the effects of experimental conditions to prepare SAPO-34 with respect to crystallinity of the final product phase. The results showed that the favorable phase crystallinity was improved by increasing the hydrothermal synthesis temperature and organic template content, whereas increasing the water content in synthesis mixture decreased the crystallinity. No significant changes in crystallinity of the final products were observed by increasing the synthesis duration. In addition, zeolite SAPO-5, which was formed as the...
A study of the electrophoretic deposition of Bioglass® suspensions using the Taguchi experimental design approach
, Article Journal of the European Ceramic Society ; Volume 30, Issue 14 , October , 2010 , Pages 2963-2970 ; 09552219 (ISSN) ; Simchi, A ; Ryan, M. P ; Boccaccini, A. R ; Sharif University of Technology
2010
Abstract
This paper presents a study of the Taguchi design method to optimise the rate of electrophoretic deposition (EPD) of Bioglass® particles from aqueous suspensions. The effect of Bioglass® concentration, pH and electric field was investigated. An orthogonal array of L16 type with mixed levels of the control factors was utilized. Multivariate analysis of variance (MANOVA) and regression analysis based on the partial least-square method were used to identify the significant factors affecting the deposition rate and its stability during constant-voltage EPD. It was found that the pH of the suspension significantly influences the deposition rate whereas the applied electric field has the smallest...
Optimization of parameters for synthesis of mfi nanoparticles by taguchi robust design
, Article Chemical Engineering and Technology ; Volume 33, Issue 6 , 2010 , Pages 902-910 ; 09307516 (ISSN) ; Soltanieh, M ; Kazemian, H ; Sharif University of Technology
2010
Abstract
MFI-type zeolite was successfully synthesized by hydrothermal crystallization of clear synthesis mixtures. A statistical experimental design method (the Taguchi method with an L8 orthogonal array) was implemented to optimize the experimental conditions for the preparation of MFI nanocrystals with respect to particle size and distribution as the desirable properties. In the Taguchi experimental design, crystallization temperature, water content, template/silica molar ratio, aluminum content, as well as the presence of alkaline cations were chosen as significant parameters affecting the properties. It was shown that water and aluminum content of the synthesis solution were the most important...
Evaluation of compressive and split tensile strength of slag based aluminosilicate geopolymer reinforced by waste polymeric materials using Taguchi method
, Article Materials Research Express ; Volume 8, Issue 2 , February , 2021 ; 20531591 (ISSN) ; Tayebi, M ; Shafiee, A ; Aghaie, A ; Sharif University of Technology
IOP Publishing Ltd
2021
Abstract
In this work, slag based aluminosilicate geopolymer was reinforced with polymeric fibers including, polyester (PES) (waste tire cap plies), polymeric particles including polyethylene terephthalate (PET) (waste water bottle), styrene-butadiene rubber (SBR) (waste tire), and polyvinyl chloride (PVC) (waste water hose). The tensile and compressive strength of the material was evaluated. Taguchi method was employed to assess the influence of the effective parameters on the mechanical characteristics of the geopolymer composite. QUALITEK-4 software was used to create the L32 orthogonal array with 192 (96+96) geopolymer specimens and 32+32 experiments. Analysis of variance (ANOVA) was utilized to...
Optimization of supercritical carbon dioxide extraction of essential oil from Dracocephalum kotschyi Boiss: An endangered medicinal plant in Iran
, Article Journal of Chromatography A ; Volume 1422 , 2015 , Pages 73-81 ; 00219673 (ISSN) ; Taji, S ; Goodarznia, I ; Sharif University of Technology
Elsevier
2015
Abstract
Extraction of the essential oil from a medicinal plant called Dracocephalum kotschyi Boiss was performed by green technology of supercritical carbon dioxide (SC-CO2) extraction. A Taguchi orthogonal array design with an OA16 (45) matrix was used to evaluate the effects of five extraction variables: pressure of 150-310bar, temperature of 40-60°C, average particle size of 250-1000μm, CO2 flow rate of 2-10ml/s and dynamic extraction time of 30-100min. The optimal conditions to obtain the maximum extraction yield were at 240bar, 60°C, 500μm, 10ml/s and 100min. The extraction yield under the above conditions was 2.72% (w/w) which is more than two times the maximum extraction yield that has been...
Taguchi analysis of extrusion variables and composition effects on the morphology and mechanical properties of EPR-g-MA toughened polyamide 6 and its composite with short glass fiber
, Article Materials Science and Engineering A ; Volume 506, Issue 1-2 , 2009 , Pages 45-57 ; 09215093 (ISSN) ; Fereydoon, M ; Sharif University of Technology
2009
Abstract
Various compositions of maleated ethylene-propylene-rubber (EPR-g-MA) toughened polyamide 6 without and with short glass fiber, i.e. 5-20 wt.% rubber and 5-20 wt.% fiber, are prepared using an industrial twin-screw extruder at different levels of feed rate (100-250 kg/h), screw speed (200-450 rpm) and barrel temperature (230-260 °C). Trial runs designed based on the Taguchi's orthogonal arrays are subjected to tensile, impact, scanning electron microscopy (SEM) and optical microscopy tests; and the results are used to perform the analysis of variance (ANOVA). It is shown that the rubber particle size decreases significantly by increasing the rubber content for the unreinforced blend. The...