Influence Of Substrate Temperatures On Structural, Morphological And Optical Properties Of Rf-Sputtered Anatase Tio 2 Films
A.S. Md Abdul Haseeb
In this investigation, TiO 2 thin films were deposited on glass substrates at varying substrate temperatures from room temperature to 300 °C by radio-frequency (RF) magnetron sputtering at an elevated sputtering pressure of 3 Pa. As-deposited TiO 2 films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), field emission Auger electron microscopy (FEAES), and UV-visible-NIR spectrophotometry. The XRD results reveal that all the as-deposited films possessing the anatase structure and crystallinity of TiO 2 films appears to deteriorate slightly at higher substrate temperatures. The crystallite size of the as-deposited films at different substrate temperatures ...
Selective Area Rare-Earth Doping Of Planar Glass Samples For Monolithic Integration Of Optically Passive And Active Waveguides
A.S. Md Abdul Haseeb
Successful demonstration of selective area doping of planar glass samples for monolithic integration of optically passive and active devices on a single chip is presented. Salt solution of erbium was delivered onto pre-sintered germano-silicate samples via a syringe. The samples were then consolidated to form dense glass layers containing regions doped with rare earth. Erbium tri-chloride solution, 0.1 M, was used during the solution doping phase, with the resulting erbium atomic percentage ranging from more than 0.1-0.4%, increasing linearly with the number of drips applied. © 2008 Elsevier GmbH. All rights reserved.
Advanced Wide-Area Angle Stability And Voltage Control, 2010 CINVESTAV
Advanced Wide-Area Angle Stability And Voltage Control, Arturo Roman Messina, Ramon Jimenez, Rafael Castellanos
A. R. Messina
No abstract provided.
Evaluation Of Stochastic Global Optimization Methods For Modeling Vapor-Liquid Equilibrium Data, 2010 National University of singapore
Evaluation Of Stochastic Global Optimization Methods For Modeling Vapor-Liquid Equilibrium Data, Adrian Bonilla-Petriciolet, Gade Pandu Rangaiah, Juan Gabriel Segovia-Hernández
Parameter estimation for vapor–liquid equilibrium (VLE) data modeling plays an important role in design, optimization and control of separation units. This optimization problem is very challenging due to the high non-linearity of thermodynamic models. Recently, several stochastic optimization methods such as Differential Evolution with Tabu List (DETL) and Particle Swarm Optimization (PSO) have evolved as alternative and reliable strategies for solving global optimization problems including parameter estimation in thermodynamic models. However, these methods have not been applied and compared with respect to other stochastic strategies such as Simulated Annealing (SA), Differential Evolution (DE) and Genetic Algorithm (GA) in the ...
Extractive Dividing Wall Column: Design And Optimization, 2010 Universidad de Guanajuato
Extractive Dividing Wall Column: Design And Optimization, Cristofer Bravo-Bravo, Juan Gabriel Segovia-Hernandez, Claudia Gutiérrez-Antonio, Ana Luisa Duran, Adrian Bonilla-Petriciolet, Abel Briones-Ramírez
This paper proposes a novel extractive dividing wall distillation column, which has been designed using a constrained stochastic multiobjective optimization technique. The approach is based on the use of genetic algorithms to determine the design that minimizes energy consumption and total annualized cost. Several case studies are used to show the feasibility of performing extractive separations in dividing wall distillation columns. The simulation results show the effect of the main variables on the complex extractive distillation process.
A Comparative Study Of Particle Swarm Optimization And Its Variants For Phase Stability And Equilibrium Calculations In Multicomponent Reactive And Non-Reactive Systems, 2010 Universidad de Guanajuato
A Comparative Study Of Particle Swarm Optimization And Its Variants For Phase Stability And Equilibrium Calculations In Multicomponent Reactive And Non-Reactive Systems, Adrian Bonilla-Petriciolet, Juan Gabriel Segovia-Hernández
Particle swarm optimization is a novel evolutionary stochastic global optimization method that has gained popularity in the chemical engineering community. This optimization strategy has been successfully used for several applications including thermodynamic calculations. To the best of our knowledge, the performance of PSO in phase stability and equilibrium calculations for both multicomponent reactive and non-reactive mixtures has not yet been reported. This study introduces the application of particle swarm optimization and several of its variants for solving phase stability and equilibrium problems in multicomponent systems with or without chemical equilibrium. The reliability and efficiency of a number of particle swarm ...
Phase Stability And Equilibrium Calculations In Reactive Systems Using Differential Evolution And Tabu Search, 2010 National University of singapore
Phase Stability And Equilibrium Calculations In Reactive Systems Using Differential Evolution And Tabu Search, Adrian Bonilla-Petriciolet, Gade Pandu Rangaiah, Juan Gabriel Segovia-Hernández, José Enrique Jaime-Leal
In this chapter, we present the application of Tabu search and Differential Evolution for performing phase equilibrium calculations in reactive systems, and compare their performance for benchmark problems in this area. In particular, we have analyzed the reliability and efficiency of these methods using a variable transformation approach for modeling the phase equilibrium behavior of reactive mixtures.
Harmony Search For Parameter Estimation In Vapor-Liquid Equilibrium Modeling, 2010 Universidad de Guanajuato
Harmony Search For Parameter Estimation In Vapor-Liquid Equilibrium Modeling, Adrian Bonilla-Petriciolet, Juan Gabriel Segovia-Hernandez, Juan Jose Soto-Bernal
This study introduces the application of Harmony Search (HS) method for solving the parameter estimation problem in vapor-liquid equilibrium data modeling. The performance of this novel stochastic optimization strategy has been tested using several sets of binary vapor-liquid equilibrium data with local composition models and the classical approach of least squares. Our results indicate that HS is a promising meta-heuristic for solving global optimization problems in the modeling of phase equilibrium and may offer a better performance than those obtained using current stochastic methods such as the Simulated Annealing or the Particle Swarm Optimization.
Control Properties Of Thermally Coupled Extractive Distillation Sequences, 2010 Universidad de Guanajuato
Control Properties Of Thermally Coupled Extractive Distillation Sequences, Jose De Jesus Ibarra-Sánchez, Juan Gabriel Segovia-Hernandez, Salvador Hernandez, Hector Hernandez-Escoto, Adrian Bonilla-Petriciolet
The structure of the thermally coupled distillation systems offers some control challenges arising from the transfer of vapor (or liquid) streams between the columns. In particular, the presence of recycle streams for coupled schemes has influenced the notion that control problems might be expected during the operation of those systems with respect to the rather well-known behavior of conventional distillation sequences. In this work, we analyze the control properties of thermally coupled extractive distillation schemes. The control properties are analyzed with the application of the singular value decomposition technique and a closed-loop analysis. The results showed that the energy savings ...
Padé Functions For Modeling Adsorption Data, 2010 Instituto Tecnológico de Aguascalientes
Padé Functions For Modeling Adsorption Data, Didilia I. Mendoza-Castillo, Adrian Bonilla-Petriciolet, Juan Jauregui-Rincon
In this study, we report the application of Padé approximants for fitting of adsorption kinetic and equilibrium data. Specifically, we have compared the results of data fitting using these rational functions and those obtained with conventional adsorption models. The adsorption of cadmium ions from water by bone char was used as case of study. Our results show that Padé approximants is an alternative and flexible approach to improve the results of adsorption data modeling.
Optimization Of An Extractive Dividing Wall Column Using Genetic Algorithms, 2010 Universidad de Guanajuato
Optimization Of An Extractive Dividing Wall Column Using Genetic Algorithms, Cristofer Bravo-Bravo, Juan Gabriel Segovia-Hernandez, Salvador Hernandez, Claudia Gutierrez-Antonio, Adrian Bonilla-Petriciolet, Abel Briones-Ramirez
This work proposes an extractive dividing wall distillation column, optimal designs for which are obtained through a constrained stochastic multiobjective optimization technique. The stochastic procedure allows manipulate 15 variables simultaneously; six are continuous and the rest of them are integer. All resulting optimal designs are rigorous, since the optimization procedure is coupled to Aspen PlusTM. Several case studies are used to show the feasibility of performing extractive separations in dividing wall distillation columns. The numerical performance shows that this method appears to be robust and suitable in the design of intensified distillation systems (with dividing wall).
Prediction Of Steady State Input Multiplicities For The Reactive Flash Separation Using Reaction-Invariant Composition Variables, 2010 Universidad de Guanajuato
Prediction Of Steady State Input Multiplicities For The Reactive Flash Separation Using Reaction-Invariant Composition Variables, Jose Enrique Jaime-Leal, Adrian Bonilla-Petriciolet, Juan Gabriel Segovia-Hernandez, Salvador Hernandez
In this study, we report a new approach for predicting and analyzing steady state input multiplicities in reactive flash separation processes. Necessary conditions are suggested to detect these multiple steady states using reaction-invariant composition variables. Our results suggest that the conditions proposed for identifying the presence of input multiplicities of non-reactive systems are useful for the analysis of reactive systems if transformed composition variables are employed. Performance of our approach is illustrated using MTBE production as case of study.
A Short Method To Calculate Reactive Residue Curve Maps, 2010 Universidad de Guanajuato
A Short Method To Calculate Reactive Residue Curve Maps, Marcelino Carrera-Rodriguez, Juan Gabriel Segovia-Hernandez, Adrian Bonilla-Petriciolet
Reactive residue curve maps (RRCM) are useful for the design of reactive distillation columns as a tool to establish feasible zones of reaction-separation. The calculation of RRCM usually involves great computational effort due to the nonlinearity of the model equations and its iterative nature for the determination of reactive phase equilibrium. In this study, a simplified method for the generation of RRCM is presented. This method is based on the application of reaction-invariant composition variables and assumes that the phase equilibrium constants and the relative volatilities are independent of the temperature. These assumptions allow avoiding iterative calculations for obtaining a ...
Extraction Of Silver From Waste X-Ray Films By Thiosulphate Leaching, 2010 Karadeniz Technical University
Extraction Of Silver From Waste X-Ray Films By Thiosulphate Leaching, Ersin Y. Yazici, Ahmet Deniz Bas, Haci Deveci
Ahmet Deniz Bas
No abstract provided.
Cohesiveness And Flowability Properties Of Silica Gel Powder, 2010 University of Malaya
Cohesiveness And Flowability Properties Of Silica Gel Powder, Abdul Aziz Abdul Raman
Abdul Aziz Abdul Raman
Problem statement: The measurement of powder flowability is a major concern for most industrial processes that deal with the handling of bulk solids as raw materials, intermediates, or products. Approach: The influence of particle size on the flowability of silica gel was investigated using aerated and non-aerated methods. The aerated method involved the measurement of the Hausner Ratio (HR) and Angle Of Repose (AOR) using a Hosokawa Powder Tester (PT-S), while the non-aerated method involved a Cohesion Index (CI) measurement based on a Stable Micro Systems TA.XT Plus texture analyzer. The mean size diameters of the fine and coarse ...
Application Of Natural Clay To Formulate Nontraditional Completion Fluid That Triples Oil Productivity, 2010 University of Malaya
Application Of Natural Clay To Formulate Nontraditional Completion Fluid That Triples Oil Productivity, Abdul Aziz Abdul Raman
Abdul Aziz Abdul Raman
In the last decades, the problem of perforation damage has been considered as the major factor for the reduction of oil productivity. Underbalance perforation is considered as one of the best means to minimize or overcome this problem. By maintaining wellbore pressure lower than formation pressure, perforation damage could be minimize or eliminated. This can be achieved by the use of nontraditional lightweight completion fluid. This paper presents the effect of natural clay in formulating nontraditional completion fluid to ensure successful perforation job and increase of production rate. Natural clay is used as homogenizing agent to create a stable and ...
Methanol Recovery During Transesterification Of Palm Oil In A Tio2/Al2o3 Membrane Reactor: Experimental Study And Neural Network Modeling, Abdul Aziz Abdul Raman
Abdul Aziz Abdul Raman
High quality palm oil biodiesel can be produced by combination of alkali transesterification and separation processes in a TiO2/Al 2O3 membrane reactor. Due to the small molecular size, methanol molecules are able to pass through the membrane along with the products. Since methanol is one of the process reactants it is necessary to be recovered. Methanol recovery by means of continuous distillation was employed and the influences of different operational parameters including heating temperature permeate flow rate and reactants ratio were investigated. The results indicate that these parameters have significant effects on the rate of methanol recovery. To simulate ...
Phytoremediation Of Soil Contaminated With Used Lubricating Oil Using Jatropha Curcas, 2010 University of Malaya
Phytoremediation Of Soil Contaminated With Used Lubricating Oil Using Jatropha Curcas, Abdul Aziz Abdul Raman
Abdul Aziz Abdul Raman
Soil contamination by used lubricating oil from automobiles is a growing concern in many countries, especially in Asian and African continents. Phytoremediation of this polluted soil with non-edible plant like Jatropha curcas offers an environmental friendly and cost-effective method for remediating the polluted soil. In this study, phytoremediation of soil contaminated with 2.5 and 1% (w/w) waste lubricating oil using J. curcas and enhancement with organic wastes [Banana skin (BS), brewery spent grain (BSG) and spent mushroom compost (SMC)] was undertaken for a period of 180 days under room condition. 56.6% and 67.3% loss of waste ...
Effective Sba-15 Supported Gold Catalysts For Gluconic Acid Synthesis, 2010 Institute of Chemical Engineering, Polish Academy of Sciences
Effective Sba-15 Supported Gold Catalysts For Gluconic Acid Synthesis, K. Odrozek, J. J. Malinowski, J. Mrowiec-Bialon
Janusz J. Malinowski
No abstract provided.
Survey Report On Training And Spending On Customer Care Services, 2010 The University of the South Pacific
Survey Report On Training And Spending On Customer Care Services, Deogratias Harorimana Sr
Dr Deogratias Harorimana
In a bid to promote and develop good customer care service in various sectors of Rwandan economy, a survey was conducted to assess progress and trends on customer service capacity building. Although shortcomings are there, there have been efforts and registered trends across the country on service delivery front. Investment in Capacity Building IS happening in certain sectors but this is unevenly distributed. In 2008 companies had started recognizing the significance of good service and cultivate a good working environment and training. From 2009, there was a decline in investment in capacity building in front office and key service delivery ...