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Design and Operation of Proper Freeze Drying Process to Recover Active Biological Agent
, M.Sc. Thesis Sharif University of Technology ; Rosta Azad, Reza (Supervisor)
Abstract
One of the most important unit operations in the production of dry powder biological products involves a freeze dryer apparatus. In this process, Liqueur, which is containing the α-amylase enzyme, undergoes a frigidity condition in which loses its moisture during sublimation. Under these circumstances, applying an adequate supply of sublimation enthalpy without raising the temperature of the frigid material up to melting, plays an important role in the quality of the product and preventing degradation of the α-amylase enzyme. Freeze drying depends on two main factors; time and energy. Furthermore, it is necessary to obtain an optimal temperature and pressure for different steps and...
Modeling and comparison of different simulations for release of amoxicillin from chitosan hydrogels
, Article Polymer - Plastics Technology and Engineering ; Volume 52, Issue 11 , 2013 , Pages 1147-1153 ; 03602559 (ISSN) ; Ramazani S. A., A ; Shafiee, M ; Alemzadeh, I ; Ebrahimi, H ; Sharif University of Technology
2013
Abstract
In this research work, different devices made of glutaraldehyde cross-linked chitosan hydrogels loaded by amoxicillin, have been prepared using freeze-drying method. Effects of system parameters such as cross-linker concentration, pH, and gel structure on the morphology and release behavior of devices have been investigated using standard methods. Morphological studies were performed using SEM instrument and controlled releases are followed via spectrophotometeric method. Reaction of glutaraldehyde with chitosan has been studied using FTIR instrument. SEM micrographs have shown that with increasing cross-linker percentage in hydrogel, pore sizes increased where pore size distribution...
Modeling of two-phase flow in porous media with heat generation
, Article International Journal of Multiphase Flow ; Volume 69 , March , 2015 , Pages 115-127 ; 03019322 (ISSN) ; Saidi, M. S ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
The main purpose of this work is investigation of coolability of a boiling debris bed. The main governing equations are derived using volume averaging technique. From this technique some specific interfacial areas between phases are appeared and proper relations for modeling these areas are proposed. Using these specific areas, a modification for the Tung/Dhir model in the annular flow regime is proposed. The proposed modification is validated and the agreements with experimental data are good. Finally, governing equations and relations are implemented in the THERMOUS program to model two-phase flow in the debris bed in the axisymmetric cylindrical coordinate. Two typical configurations...
Bilayered heparinized vascular graft fabricated by combining electrospinning and freeze drying methods
, Article Materials Science and Engineering C ; Volume 94 , 2019 , Pages 1067-1076 ; 09284931 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Small diameter vascular grafts (<6 mm) are highly demanded for patients suffering from severe occluded arteries to be used as a bypass or substituted conduit. Fabricating a graft with appropriate structural, mechanical and cell growth properties which has simultaneously anti-thrombogenic trait is a challenge nowadays. Here, we proposed a bilayer heparinized vascular graft that can mimic the structural and mechanical characteristics close to those of the native coronary artery by combining electrospinning and freeze drying methods. In this study, the inner layer was made by co-electrospinning of synthetic polymer, poly-caprolactone (PCL) and the natural polymer, gelatin (Gel). Also, heparin...
Bilayered heparinized vascular graft fabricated by combining electrospinning and freeze drying methods
, Article Materials Science and Engineering C ; Volume 94 , 2019 , Pages 1067-1076 ; 09284931 (ISSN) ; Shamloo, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Small diameter vascular grafts (<6 mm) are highly demanded for patients suffering from severe occluded arteries to be used as a bypass or substituted conduit. Fabricating a graft with appropriate structural, mechanical and cell growth properties which has simultaneously anti-thrombogenic trait is a challenge nowadays. Here, we proposed a bilayer heparinized vascular graft that can mimic the structural and mechanical characteristics close to those of the native coronary artery by combining electrospinning and freeze drying methods. In this study, the inner layer was made by co-electrospinning of synthetic polymer, poly-caprolactone (PCL) and the natural polymer, gelatin (Gel). Also, heparin...
Dry sliding wear behavior of SiCP/QE22 magnesium alloy matrix composites
, Article Materials Science and Engineering A ; Volume 435-436 , 2006 , Pages 653-657 ; 09215093 (ISSN) ; Masoudi, A ; Purazrang, K ; Sharif University of Technology
2006
Abstract
In present work, an attempt has been made to investigate the wear behavior of particle reinforced composites based on one of the proper magnesium alloys. The SiCP/QE22 composites and QE22 unreinforced specimens were produced via the powder metallurgy route. The volume fractions of SiC particles with three different shapes, i.e. sharp, blocky and round, were selected in the range of 10-25 vol.%. The dry sliding tests were conducted on unreinforced matrix and SiCP/QE22 composites using pin-on-disk apparatus, according to ASTM G99-95a standard. The applied loads were selected as 3, 5 and 20 N. The tests were carried out under sliding speeds of 0.5 and 1.2 m/s. In all tests, the sliding...
Dynamic compaction method in physical model tests
, Article Scientia Iranica ; Volume 13, Issue 2 , 2006 , Pages 187-192 ; 10263098 (ISSN) ; Sharif University of Technology
Sharif University of Technology
2006
Abstract
In this paper, physical modeling tests are conducted to study some aspects of the dynamic compaction method. The loose models are prepared with dry sand. Four cylindrical tampers with different weight and cross section areas are used for compaction of the models and dropped from various heights. Strain gage type total stress measuring sensors are placed at different levels inside the model to measure the transferred vertical stresses due to collision of the tamper with the surface of the models. The typical stress time histories are presented. Improvement depth and crater depth and diameter created on the model surface are studied, among the various parameters affecting the phenomena. Using...
Dynamic parameters of dry sand using one dimensional shaking table tests
, Article 6th International Conference on Physical Modelling in Geotechnics, ICPMG'06, Hong Kong, 4 August 2006 through 6 August 2006 ; Volume 1-2 , 2006 , Pages 279-283 ; 041541587X (ISBN); 9780415415873 (ISBN) ; Torghabeh, E. A ; Farahi Jahromi, H ; Sharif University of Technology
2006
Abstract
In this paper the dynamic properties of Babolsar dry sand was investigated through one dimensional shaking table tests. 8 models of Babolsar loose dry sand under low confining pressures, were subjected to different harmonic and irregular dynamic loadings. The container was a laminar shear box having 24 layers each moving on the lower one. The dynamic properties including shear wave velocity, maximum shear modulus and damping ratio of the samples were addressed in this project. © 2006 Taylor & Francis Group, London
Machine learning approach for carrier surface design in carrier-based dry powder inhalation
, Article Computers and Chemical Engineering ; Volume 151 , 2021 ; 00981354 (ISSN) ; Alishiri, M ; Lau, R ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this study, a machine learning approach was applied to evaluate the impact of operating and design variables on dry powder inhalation efficiency. Emitted dose and fine particle fraction data were extracted from the literature for a variety of drug and carrier combinations. Carrier surface properties are obtained by image analysis of SEM images reported. Models combining artificial neural network and genetic algorithm were developed to determine the emitted dose and fine particle fraction. Design strategies for the carrier surface were also proposed to enhance the fine particle fractions. © 2021 Elsevier Ltd
Aerodynamic Improvement of Cooling Systems for a Thermal Power Plant Using CFD
, M.Sc. Thesis Sharif University of Technology ; Darbandi, Masoud (Supervisor)
Abstract
This research considers the wind effects on the thermal deficiency of natural draught dry cooling tower (NDDCT) using the CFD tool. To have a realistic study, the NDDCT of Shazand Powerplant, located in Shazand, Iran, is simulated as the sample cooling tower design points. Considering of Shazand NDDCT model, the mal-effects of local wind were studied against its thermal efficiency. As is known, the thermal efficiency of a NDDCT can be affected by local wind in either its upper (i.e., outlet section) or lower (i.e., the radiator section) parts. In this study, a full study is performed to quantify the mal-effects of local wind on either upper or lower parts of one tower. The results show that...
Production of New Nanocomposites for Neutron and Gamma Shielding and Modeling of the Attenuation Phenomena Using Computational Methods
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohammad (Supervisor) ; Vosoughi, Naser (Supervisor) ; Kiani, Mohammad Amin (Co-Supervisor)
Abstract
If nuclear radiation is not weakened and absorbed, it can cause serious damage to human devices or the environment. Dual-purpose dry casks are one of the sources of nuclear radiation production as a place to keep the spent fuel assemblies. One of the ways to protect against them is to use shield. One of the most common of them is composite shield. The composite used in this study has a polymer matrix. The matrix of the used polymer is epoxy resin. In this study, two separate composites have been made to attenuate neutron and gamma radiation. In this thesis, first, by using the MCNPX code, the necessary simulations for the design and construction of composite shields have been carried out....
Investigation of the effect of Al-5Ti-1B grain refiner on dry sliding wear behavior of an Al-Zn-Mg-Cu alloy formed by strain-induced melt activation process
, Article Materials and Design ; Volume 46 , 2013 , Pages 766-775 ; 02641275 (ISSN) ; Aghdam, B. G ; Rahnoma, H. E ; Emamy, M ; Sharif University of Technology
2013
Abstract
This study was undertaken to investigate the influence of Al-5Ti-1B master alloy and modified strain-induced melt activation process on the structural characteristics, mechanical properties and dry sliding wear behavior of Al-12Zn-3Mg-2.5Cu aluminum alloy. The optimum amount of Ti containing master alloy for proper grain refining was selected as 2. wt.%. The alloy was produced by modified strain-induced melt activation (SIMA) process. Reheating condition to obtain a fine globular microstructure was optimized. The optimum temperature and time in strain-induced melt activation process are 575. °C and 20. min, respectively. T6 heat treatment was applied for all specimens before tensile testing....
Quality evaluation of Jajrood river (IRAN) by quality indices methods
, Article 2012 International Conference on Advances in Materials Science and Engineering, AMSE 2012, Seoul, 9 December 2012 through 10 December 2012 ; Volume 650 , 2013 , Pages 652-657 ; 10226680 (ISSN); 9783037855997 (ISBN) ; Hasanian, H ; Sharif University of Technology
2013
Abstract
This Regular evaluation and analysis of river quality helps accurate management to reach acceptable quality. In this study, water quality indices (WQI) method applied to evaluate quality of Jajrood River which is one of the main sources of Tehran drinking water. It helps to subsidize management actions in Jajrood watershed. Sampling carried out for 9 years during 2001-2010 in 10 stations along the river in wet and dry stations to identify water quality and the main source of pollution. Results show water quality in all stations classifies as medium according to National Sanitation Foundation (NSF) and water quality index in wet season is better than the corresponding value in dry seasons....
Analysis of near well-bore behavior of gas condensate reservoir in production stage
, Article Petroleum Science and Technology ; Volume 30, Issue 24 , 2012 , Pages 2594-2603 ; 10916466 (ISSN) ; Aminshahidy, B ; Sanati, A ; Taghikhani, V ; Sharif University of Technology
2012
Abstract
The formation of condensate banking in the near well-bore region will lead to the reduction in gas relative permeability and loss of well deliverability. This loss is investigated by conducting a series of fine grid numerical compositional simulation with the gas condensate and dry gas reservoir data. Also, a method for calculation of condensate blockage skin factor is introduced in which the skin factor is calculated using dry gas and gas condensate simulation production data. The authors also found that absolute permeability and pressure drawdown of the producing well have significant influence on the well gas deliverability and condensate blockage skin factor
H∞ Robust control of continuous fluidized tea bed dryer
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings, 13 November 2009 through 19 November 2009, Lake Buena Vista, FL ; Volume 10, Issue PART A , 2010 , Pages 321-327 ; 9780791843833 (ISBN) ; Hajikolaei, K. H ; Motamedi, M ; Vossoughi, G. R ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2010
Abstract
During drying processes, moisture control of food products, such as dried tea, is of great importance. Improving dryer control, results in consistent production and reduction of energy consumption. However, the dryer is a complex system associated with model uncertainties. In this paper, a realistic uncertain model of a fluidized tea bed dryer is considered. Moisture content and temperature of tea leaves (or other products) are controlled at desired values by manipulating tea leaves heating rate. Developing a code by Robust Control Toolbox of MATLAB and modeling uncertainties, a robust controller is designed based on ′-synthesis with DK-iteration algorithm. Results show that in the presence...
Motion analysis of a vibrational micro-robot with two perpendicular harmonic actuators and deriving the design parameters in stick-slip-jump mode
, Article Journal of Sound and Vibration ; Volume 372 , 2016 , Pages 266-282 ; 0022460X (ISSN) ; Vossoughi, G ; Salarieh, H ; Sharif University of Technology
Academic Press
2016
Abstract
In this paper, the motion of a micro-robot with two perpendicular vibrational actuators is studied. In this work, separation of the micro-robot body from the substrate of motion takes place. The separation happens while the vertical force applied to the micro-robot body is greater than the micro-robot weight. In this condition, body of the micro-robot jumps apart from the substrate and then returns to it, and this motion will continue intermittently until it becomes damped. In this condition, the motion mechanism of "stick-slip" is not valid and we introduce a new mechanism of hybrid motion as "stick-slip-jump". In this case (hybrid motion), the micro-robot dynamics is modeled and the result...
Infrared thin layer drying of saffron (Crocus sativus L.) stigmas: Mass transfer parameters and quality assessment
, Article Chinese Journal of Chemical Engineering ; 2016 ; 10049541 (ISSN) ; Ghanbarian, D ; Maghsoodi, V ; Moheb, A ; Sharif University of Technology
Chemical Industry Press
Abstract
Saffron is the most precious and expensive agricultural product. A dehydration treatment is necessary to convert Crocus sativus L. stigmas into saffron spice. To the best of our knowledge, no information on mass transfer parameters of saffron stigmas is available in the literature. This study aimed at investigating the moisture transfer parameters and quality attributes of saffron stigmas under infrared treatment at different temperatures (60, 70, ..., 110°C). It was observed that the dehydration process of the samples occurred in a short accelerating rate period at the start followed by a falling rate period. The effective moisture diffusivity and convective mass transfer coefficient were...
Study of a piezo-electric actuated vibratory micro-robot in stick-slip mode and investigating the design parameters
, Article Nonlinear Dynamics ; Volume 89, Issue 3 , 2017 , Pages 1927-1948 ; 0924090X (ISSN) ; Salarieh, H ; Vossoughi, G ; Sharif University of Technology
Springer Netherlands
2017
Abstract
In this paper, the stick-slip motion of a new type of micro-robot with two perpendicular vibratory actuators is studied which is based on the friction drive principle. The actuators are based on piezo-electric phenomenon which are driven by a harmonic voltage, and both of them are mounted on the micro-robot body. These actuators cause the micro-robot moves forward or backward due to the specified phase difference between the voltages applied to vertical and horizontal actuators. Since the dynamics of the actuators affects on the micro-robot motion, so to derive the equations of motion the coupled dynamics between the body of robot and vibratory masses of actuators are considered, and the...
Infrared thin layer drying of saffron (Crocus sativus L.) stigmas: Mass transfer parameters and quality assessment
, Article Chinese Journal of Chemical Engineering ; Volume 25, Issue 4 , 2017 , Pages 426-432 ; 10049541 (ISSN) ; Ghanbarian, D ; Maghsoodi, V ; Moheb, A ; Sharif University of Technology
Chemical Industry Press
2017
Abstract
Saffron is the most precious and expensive agricultural product. A dehydration treatment is necessary to convert Crocus sativus L. stigmas into saffron spice. To the best of our knowledge, no information on mass transfer parameters of saffron stigmas is available in the literature. This study aimed at investigating the moisture transfer parameters and quality attributes of saffron stigmas under infrared treatment at different temperatures (60, 70, …, 110 °C). It was observed that the dehydration process of the samples occurred in a short accelerating rate period at the start followed by a falling rate period. The effective moisture diffusivity and convective mass transfer coefficient were...
Storage of Ag nanoparticles in pore-arrays of SU-8 matrix for antibacterial applications
, Article Journal of Physics D: Applied Physics ; Volume 42, Issue 13 , 2009 ; 00223727 (ISSN) ; Abdolahad, M ; Asadi, R ; Sharif University of Technology
2009
Abstract
Silver nanoparticles (NPs) stored in pore-arrays (pa) SU-8 photoresist layer were utilized as an antibacterial nanocomposition against E. coli bacteria. The pa-SU-8 matrix was fabricated by an optical interference lithography method resulting in small pores with a diameter of ∼50 nm and a depth of ∼100 nm. The Ag NPs were deposited on the soft polymeric matrix at different drying temperatures of 50 and 90 °C. X-ray photoelectron spectroscopy showed that the deposited silver NPs were substantially in the metallic state, independent from the drying condition. However, the concentration of the immobilized Ag NPs on the film surface increased (by a factor of 2.5) at the higher drying...