Loading...
Search for:
effectiveness-factor
0.005 seconds
Kinetic behaviour of α-galactosidase produced by Absidia griseola: A comparison between free and immobilized forms of the enzyme
, Article World Journal of Microbiology and Biotechnology ; Volume 18, Issue 7 , 2002 , Pages 649-653 ; 09593993 (ISSN) ; Moazami, N ; Mirdamadi, S ; Mesgarian, R ; Vossoughi, M ; Bakhtiari, M. R ; Sharif University of Technology
2002
Abstract
In this research the characteristics of free (partially purified) and immobilized (mould pellets of Absidia griseola) α-galactosidase have been investigated. Inhibition studies of the enzyme showed that p-nitrophenol and sucrose do not have any inhibitory effect on the enzyme, but that galactose is a competitive inhibitor. In the immobilized form, inhibition was lower than in the free enzyme and the level of inhibition decreased as the temperature increased. The activity and stability of free and immobilized enzyme were investigated with respect to temperature, and the results showed that the optimal temperature range of the free enzyme was 45-50°C, while the immobilized enzyme had an...
Recognizing Influential Macro Environmental Factors in Home Medical Equipments Industry and Proposing Domestic Guideline for Successful Marketing Strategy and Marketing Mix Planning
, M.Sc. Thesis Sharif University of Technology ; Najmi, Manouchehr (Supervisor)
Abstract
Diabetes is one of the most prevalent chronic diseases. Blood glucose control provides diabetics with the opportunity to keep their normal lifestyle, being a productive resource in the society, while ignoring to do so impose a huge cost to the society. Hence, it is of vital importance to find an appropriate approach to control and prevent the subsequent complications of diabetes. One of the most effective approaches is self monitoring of blood glucose (SMBG), which is now available through the commitment of a number of medical equipment companies to introduce SMBG products to the market. Some of the noted companies appointed Iran medical equipment market as a target for their market...
Application of association rule mining in supplier selection criteria
, Article World Academy of Science, Engineering and Technology ; Volume 40 , 2009 , Pages 358-362 ; 2010376X (ISSN) ; Salmasi, N ; Modarres Yazdi, M ; Iranmanesh, H ; Sharif University of Technology
2009
Abstract
In this paper the application of rule mining in order to review the effective factors on supplier selection is reviewed in the following three sections 1) criteria selecting and information gathering 2) performing association rule mining 3) validation and constituting rule base. Afterwards a few of applications of rule base is explained. Then, a numerical example is presented and analyzed by Clementine software. Some of extracted rules as well as the results are presented at the end
Bauschinger effect investigation of an aluminum alloy, and its application in autofrettaged and compound tubes
, Article 2007 ASME Pressure Vessels and Piping Conference, PVP 2007, San Antonio, TX, 22 July 2007 through 26 July 2007 ; Volume 6 , 2008 , Pages 629-637 ; 0277027X (ISSN); 0791842843 (ISBN); 9780791842843 (ISBN) ; Farrahi, G. H ; Hoseini, S. H ; Sharif University of Technology
2008
Abstract
For characterizing Bauschinger effect factor (BEF) and Bauschinger modulus reduction of an A5083 aluminum alloy experimentally, several uniaxial tension- compression tests carried out in different pre-strain levels using INSTRON testing machine. BEF was investigated using both Welter and Milligan's definitions for various offset values. It was observed that Milligan's definition predicts BEF less than Welter's definition for all offset values. In addition, real loading-unloading behavior of such alloy was recorded to predict residual stresses resulting from autofrettage and shrink fit processes. Variable material properties (VMP) method, which is capable of incorporating real unloading...
Factorial Design of Experiments to Identify Effective Factors on Domestic Vehicle Emissions and Fuel Consumption
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid (Supervisor)
Abstract
Reducing air pollutant emissions from vehicles is a difficult and time consuming procedure which needs utilizing of modern emission control equipment and setting strict regulations for car factories and drivers as well. How efficient these policies are and proposing operative solutions for air quality improvement depend on developing a sustainable model which is used in vehicle emission predictions and their share in total emissions. Emission factors are not constant values as they can be affected by various operational and ambient parameters. Development of Emission inventories calls for a huge number of measurements using different vehicles in diverse conditions. Thus, recognition of...
The application of corrugated parallel bundle model to immobilized cells in porous microcapsule membranes
, Article Journal of Membrane Science ; Volume 311, Issue 1-2 , 2008 , Pages 159-164 ; 03767388 (ISSN) ; Zarrabi, A ; Khosravi, A ; Sharif University of Technology
2008
Abstract
To describe immobilized cells in porous microcapsule membranes with straight pores, a novel model called corrugated parallel bundle model (CPBM) was utilized. In this model, a network was developed with 10 main pores each composing 10 pore elements. Cell growth kinetic in the network was examined using non-structural models. Effectiveness factor and pore plugging time were calculated by solving reaction-diffusion equation set via finite difference method. The findings revealed that diffusion coefficient for lower order reactions will create a lesser impact on the reduction of effectiveness factor. These findings also indicated that the use of such supporting carrier for cell immobilization...
Investigation of wagon derailment moving on random rail irregularities Using nonlinear 3-dimentional model
, Article International Journal of Engineering, Transactions B: Applications ; Volume 21, Issue 4 , 2008 , Pages 385-400 ; 1728-144X (ISSN) ; Jalili, M. M ; Sharif University of Technology
Materials and Energy Research Center
2008
Abstract
Rail irregularity is one of the most effective factors in train derailment. theste irregularities have generally random distribution that are assumed to be stationary random and ergodic processes in space, with Gaussian amplitude probabiliy densities and zero mean values. The quality of irregularities, their distribution along the rails and wagon speed are the main factors for train derailment which is investigated in this article. The car model is nonlinear and three-dimensional with 48 DOF. Using simulation results, the safe speed for moving wagon on different types of random rail irregularities is also determined
Evaluation of Lump Sum Contracts in the Organization for Development, Renovation and Equipping Schools
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masoud (Supervisor)
Abstract
The construction industry is one of the most important economic sectors, which shares a major part of Gross Domestic Product (GDP) and employment. In Iran many development projects are designed and implemented annually which billions of Rials are due as a result of construction and operation for executive bodies. The Organization for Development, Renovation and Equipping Schools (ODRES) as the executive branch of the Ministry of Education, is one of the largest construction bodies which undertakes construction of hundreds of educational, cultural and athletic projects annually. Given that the project delivery methods and the need to choose the correct method of contract payments exerts great...
Applying path analysis method in defining effective factors in organisation agility
, Article International Journal of Production Research ; Volume 48, Issue 6 , 2010 , Pages 1765-1786 ; 00207543 (ISSN) ; Mashayekhi, A. N ; Rajabzadeh, A ; Razavian, M. M ; Sharif University of Technology
Abstract
Changes in business environment are leading firms to adopt a new production model called agile manufacturing. This term moves away from the traditional mass production paradigm and focuses on manufacturing highly customised products when customers require them. In this paper, we present an initial approach to agile organisation based on case studies in an Iranian industrial organisation. An agile organisation conceptual model has been drawn up, based on the conclusions of the case study. The study presented here is of an exploratory factor analysis and the conclusions are drawn through path analysis, propose possible routes for future research in the field of agile organisation. By the...
Design of thick-walled cylindrical vessels under internal pressure based on elasto-plastic approach
, Article Materials and Design ; Volume 30, Issue 9 , 2009 , Pages 3537-3544 ; 02641275 (ISSN) ; Kargarnovin, M. H ; Naghdabadi, R ; Sharif University of Technology
2009
Abstract
By considering the Bauschinger effect and the yield criterion of Tresca, an exact elasto-plastic analytical solution for a thick-walled cylindrical vessel made of elastic linear-hardening material is derived. Having the working pressure and geometric dimensions of the vessel, the distribution of the hoop and equivalent stresses are optimized in the way that the distribution of stresses becomes smooth in the vessel wall. Based on two optimizing methods of the hoop and equivalent stresses, the best autofrettage pressure is determined. It is shown that this pressure is more than the working pressure and depends on the three following variables: Bauschinger effect, working pressure and geometric...
Long-term deactivation of a commercial CoMo-Al2O3 catalyst in hydrodesulfurization of a naphtha stream
, Article Industrial and Engineering Chemistry Research ; Volume 48, Issue 7 , 2009 , Pages 3331-3340 ; 08885885 (ISSN) ; Hoseini, M ; Sharif University of Technology
2009
Abstract
Long-term deactivation of a commercial CoMoγ-Al2O3 catalyst used in the hydrodesulfurization of a naphtha stream was studied using 35 months of operating data of an industrial HDS fixed bed reactor. The major sulfur-containing species of the naphtha feed was identified as 2-ethyl-4-methylthiophene (2E4MT) based on GC-MS analysis. The characterization of the industrial catalysts was performed by BET, XRD, XRF, and HCN Leco analyses. The reaction rate constant of the gas-phase hydrodesulfurization reaction was calculated by fitting the industrial reactor conversion data to the Hougen-Watson rate equation, assuming that the surface reaction between the sulfur-containing species and adsorbed...
Interference modeling and generalized static capacity for uplink CDMA cellular networks
, Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 17-22 ; 1424410940 (ISBN); 9781424410941 (ISBN) ; Ashtiani, F ; Sharif University of Technology
2007
Abstract
In this paper, we propose a new approach in computing interference distribution and outage probability for uplink CDMA cellular networks. In this approach, we model time-varying interference as a discrete-time Markov chain with flexible approximation and find its steady state distribution. Our approach is based on tracing the time variation of the effective factors in interference such as spatial locations, activity status, and shadowing status for the connected users. To this end, we approximate shadowing with several discrete levels by Lloyd algorithm. Moreover, we incorporate correlation properties of the shadowing status in our model. Then, we map the effective factors onto the...
Effective factors in the treatment of kerosene-water emulsion by using UF membranes
, Article Journal of Hazardous Materials ; Volume 161, Issue 2-3 , 2009 , Pages 1216-1224 ; 03043894 (ISSN) ; Roostaazad, R ; Hesampour, M ; Nyström, M ; Ghotbi, C ; Sharif University of Technology
2009
Abstract
The effects of different parameters including membrane type (regenerated cellulose and polysulphone), transmembrane pressure (TMP), the content of oil in the feed, the flow velocity of the feed and pH on the ultrafiltration of an emulsion of kerosene in water were studied. It was found that the important factors affecting ultrafiltration were, in order, membrane type, pressure and oil concentration. The greatest flux at the optimum conditions here of 3 bar, an oil content of 3% (v/v) and with membrane type C30F was predicted as 108 L/(m2 h) that was within the range of the confidence limit of the measured value of 106 L/(m2 h). The normalised FTIR results of the virgin cellulosic membranes...