Synthesis of Nano Particles of LTA Zeolite by Means of Microemulsion Technique
Nazila
Esmaeili
Faculty of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, I.R. IRAN
author
Hossein
Kazemian
Department of Chemical and Biochemical Engineering, Faculty of Engineering,
The University of Western Ontario (UWO), London, Ontario, CANADA
author
Dariush
Bastani
Faculty of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, I.R. IRAN
author
text
article
2011
eng
This mini review article, intends to provide the essential information about microemulsion technique as a reliable approach toward the synthesis of zeolitic nano crystallites. The strategy discussed here provides a unique, effective, and potentially general methodology to the preparation of uniform and high purity nano crystallites of template-free zeolitic materials including LTA, faujasite type and other zeolitic-like materials (i.e. zeotype materials). Microemulsion is a reliable approach for controlled synthesis of uniform nano sized zeolitic particulates. On the other hand, the microwave assisted microemulsion technique has the advantages of short reaction time, producing smaller and more uniform particles with a narrower size distribution and high purity, in comparing to the conventional heating approaches.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
1
8
https://ijcce.ac.ir/article_6245_6394735606f91327f74b33f1529f2b77.pdf
dx.doi.org/10.30492/ijcce.2011.6245
Controlled Crystallization of LTA Zeolitic Nanoparticles from a Clear Solution Using Organic Template
Nazila
Esmaeili
Faculty of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, I.R. IRAN
author
Hossein
Kazemian
Department of Chemical and Biochemical Engineering, Faculty of Engineering,
The University of Western Ontario (UWO), London, Ontario, CANADA
author
Dariush
Bastani
Faculty of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, I.R. IRAN
author
text
article
2011
eng
LTA Zeolite nanoparticles was successfully synthesized from clear solution under controlled conditions using hydrothermal method using tetramethyl ammonium hydroxide as a structural directing agent. The as-synthesized LTA zeolite particles were characterized by powder X-ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), Fourier Transform InfraRed (FT-IR) spectroscopy, Energy Dispersive X-ray (EDX) analysis and surface area measuring technique of Brunauer, Emmett and Teller (BET). XRD patterns and FT-IR spectra were ascertained the formation of pure crystalline phase of 4A (i.e. LTA) zeolite. SEM micrograph was shown particles size in the range of 60 -170 nm with uniform morphology. The Si /Al ratio of the as-synthesized zeolite nanoparticles was 1.66 with a BET surface area of 421 m2/g.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
9
14
https://ijcce.ac.ir/article_6246_9037257e0cf859132025d3085884aecc.pdf
dx.doi.org/10.30492/ijcce.2011.6246
Removal of Cysteine (an Aliphatic Amino Acid) by Natural Clinoptilolite
Hossein
Faghihian
Department of Chemistry, University of Isfahan, Isfahan, I.R. IRAN
author
Massoud
Nejati-Yazdinejad
Department of Chemistry, University of Zabol, Zabol, I.R. IRAN
author
text
article
2011
eng
Amino acids have been extensively used in several processes of the pharmaceutical and food industries. Treatments for the recovery and reuse of the wastewaters generated from these processes are few and little known. This work aims at studying the influence of different variables on the sorption of L-cysteine, contained in aqueous solutions, on clinoptilolite mineral. L-Cysteine (Cys) was sorbed by Clinoptilolie (Clino) from aqueous solutions of variable concentrations, temperatures and pHs. The powder X-Ray Diffraction (XRD), InfraRed (IR) spectroscopy and thermal analysis (TG, DTG and DSC) techniques were applied for characterization of materials. The results indicated that the sorption process depends strongly on pH, temperature and concentration of amino acid. Cysteine is specifically sorbed on clinoptilolite surface sites, probably through its NH3+ moiety. The pH dependence suggests that these sites may be silanolate groups (≡Si-O-).The experimental data of sorption isotherms obtained and analyzed with Langmuir model showed that this model fitted the sorption data. Calculated thermodynamic parameters (ΔH°, ΔS°, and ΔG°) indicate that the sorption processes were exothermic.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
15
22
https://ijcce.ac.ir/article_6280_1e72a40c0774f6885fd94100689e0ba9.pdf
dx.doi.org/10.30492/ijcce.2011.6280
Synthesis, Characterization and Application of a Novel Zirconium Phosphonate Ion-Exchanger for Removal of Ni2+, Cu2+ and Zn2+ from Aqueous Solutions
Hossein
Faghihian
Department of Chemistry, Islamic Azad University, Shahreza Branch, Shahreza, I.R. IRAN
author
Hooman
Yaghobb Nejadasl
Department of Chemistry, University of Isfahan, Isfahan, I.R. IRAN
author
text
article
2011
eng
A new category of hybrid organic-inorganic zirconium phosphonate, Zr[(O3PCH2)2NC6H4CO2H].2H2O was synthesized and the applicability of the prepared sorbent as an ion-exchanger for removal of Ni2+, Cu2+ and Zn2+ from aqueous solutions was evaluated. The characterization of the synthesis product was done using TG-DTG, SEM, XRD, FT-IR techniques. Study of the sorption isotherms and its kinetic parameters was performed by atomic absorption spectroscopy and potentiometric techniques respectively. The adsorbent showed very high sorption rate and good adsorption capacity. Based on the high sorption rates, a typical ion exchange chromatography separation was performed using a column packed with the synthesized ion-exchanger and the results are discussed.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
23
31
https://ijcce.ac.ir/article_6281_2706b527b658937a9263a45f4cf45742.pdf
dx.doi.org/10.30492/ijcce.2011.6281
Study on Catalysis of Cu-Fe Metal Composite Oxides to Thermal Decomposition Behavior of Bluestone
Hui Wei
Liao
Material Science and Engineering College, Southwest University of Science and Technology,
Mianyang Sichuan, CHINA
author
Lan
Mu
Material Science and Engineering College, Southwest University of Science and Technology,
Mianyang Sichuan, CHINA
author
Min
Zhen
Material Science and Engineering College, Southwest University of Science and Technology,
Mianyang Sichuan, CHINA
author
Yan Yan
Meng
Material Science and Engineering College, Southwest University of Science and Technology,
Mianyang Sichuan, CHINA
author
text
article
2011
eng
Nano-CuFe2O4 catalysts with different Cu/Fe molar ratios (CunFemO(n+1.5m)) were prepared by hydrothermal method. The thermal decomposition performance of CunFemO(n+1.5m) on CuSO4 were determined with TG-DSC method to evaluate its catalytic activity and the roasted product was characterized by XRD. The results showed that CunFemO(n+1.5m) had superior catalytic properties and efficiency to CuSO4 crystals in 1:1 Cu/Fe molar ratios and 4% CunFemO(n+1.5m) (in mass) contained. Under these conditions, the high and low temperature decomposition peaks of CuSO4 were overlapped. The temperature and heat of decomposition were decreased by 29.5 °C and 112.1 J/g, respectively. The results were also confirmed by roasting experiments of CuSO4·5H2O in muffle furnace in the presence of CunFemO(n+1.5m) as catalyst at the same temperature.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
33
36
https://ijcce.ac.ir/article_6282_831e12ddc06b6070b7d6d0b2e31dbf39.pdf
dx.doi.org/10.30492/ijcce.2011.6282
Simple, Practical and Eco-friendly Reduction of Nitroarenes with Zinc in the Presence of olyethylene Glycol Immobilized on Silica Gel as a New Solid–liquid Phase Transfer Catalyst in Water
Ali Reza
Kiasat
Department of Chemistry, Faculty of Science, Shahid Chamran University,
P.O. Box 61357-4-3169 Ahvaz, I.R. IRAN
author
Maryam
Zayadi
Department of Chemistry, Faculty of Science, Shahid Chamran University,
P.O. Box 61357-4-3169 Ahvaz, I.R. IRAN
author
Fatemeh
Mohammad-Taheri
Department of Chemistry, Faculty of Science, Shahid Chamran University,
P.O. Box 61357-4-3169 Ahvaz, I.R. IRAN
author
Mehdi
Fallah-Mehrjard
Department of Marine Chemistry, Khoramshahr Marine Science & Technology University, Khoramshahr, I.R. IRAN
author
text
article
2011
eng
Polyethylene glycol was easily grafted to silica gel and used as a solid–liquid phase transfer catalyst in the reduction of aromatic nitro compounds. This silica-grafted polyethylene glycol is proved to be an efficient heterogeneous catalyst in the reduction of nitroarenes to the corresponding aromatic amines with zinc powder in water. The reduction reactions proceeded efficiently with excellent chemoselectivity without affecting other sensitive functional groups.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
37
41
https://ijcce.ac.ir/article_6283_9e49081495e429346700319818e4ad57.pdf
dx.doi.org/10.30492/ijcce.2011.6283
Experimental Investigation of Reactive Absorption of Ammonia and Carbon Dioxide by Carbonated Ammonia Solution
Ahad
Ghaemi
Faculty of Chemical Engineering, Iran University of Science and Technology,
P.O. Box 16765-163 Tehran, I.R. IRAN
author
Shahrokh
Shahhosseini
Faculty of Chemical Engineering, Iran University of Science and Technology,
P.O. Box 16765-163 Tehran, I.R. IRAN
author
Mohammad
Ghannadi Maragheh
Nuclear Fuel Cycle School, Nuclear Science and Technology Research Institute, P.O. Box 14155-1339 Tehran, I.R. IRAN
author
text
article
2011
eng
In this work, reactive absorption of gases in aqueous electrolyte solutions has been investigated resulting in the development of a procedure in order to calculate the concentrations of ionic and molecular species in the liquid phase. Two duplicate experiments were conducted to investigate simultaneous reactive absorption of ammonia and carbon dioxide in partially carbonated ammonia solutions. The experiments were carried out employing an absorption pilot plant. The compositions of the electrolytes (ammonia and carbon dioxide groups) have been determined using principle knowledge of electrolyte solutions. The results revealed that the concentrations of ionic and molecular species in the liquid phase drastically influence the absorption rates of ammonia and carbon dioxide.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
43
50
https://ijcce.ac.ir/article_6284_f90849c36977102fd1a4856743837c06.pdf
dx.doi.org/10.30492/ijcce.2011.6284
Chemistry of Pyrolysis and Kinetic Studies of Shea Nut (Vitellaria paradoxa) Shells Activated Carbon for Textile Waste Water Treatment
Adams Udoji
Itodo
Department of Chemistry, Kebbi State University of Science and Technology, Aliero, NIGERIA
author
Funke Wosilat
Abdulrahman
Department of Pure and Applied Chemistry, Usmanu Danfodiyo University, Sokoto, NIGERIA
author
Lawal Gusau
Hassan
Department of Pure and Applied Chemistry, Usmanu Danfodiyo University, Sokoto, NIGERIA
author
Shehu Ahmad
Maigandi
Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto, NIGERIA
author
Ugbede Onojah
Happiness
Department of Chemistry, Benue State University, Makurdi, NIGERIA
author
text
article
2011
eng
Phosphoric acid (H3PO4) and Zinc chloride (ZnCl2) catalyzed shea nut shells, subjected to a one way activation scheme was employed to study the adsorption kinetics and mode of diffusion of industrial dye uptake. Thermodynamics data obtained in this study indicate that the sorption of dye spontaneously increases with time and decreases after equilibration was reached. The adsorption follows the pseudo second order kinetic model which gave the least % SSE (0.449-1.348), best linearity (R2=0.998-0.999) and closer agreement between the experimental and calculated qe values (qe exp., 96.985/qe cal., 100.00).Mode of transport deviate from the intraparticle diffusion model. According to this study, percent dye removal coupled with the close proximity of generated data to those reviewed in literatures, is an indication that shea nut shells could compare, to a good extent with commercial activated carbon for organic dye removal from dyestuff wastewater.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
51
57
https://ijcce.ac.ir/article_6285_ef06823332b2fb3e513ce406448d0c63.pdf
dx.doi.org/10.30492/ijcce.2011.6285
Synthesis of 3,4-Dihydropyrano[c]Chromene Derivatives Using Sulfonic Acid Functionalized Silica (SiO2PrSO3H)
Ghodsi
Mohammadi Ziarani
Department of Chemistry, University of Alzahra, Tehran, I.R. IRAN
author
Alireza
Badiei
School of Chemistry, College of Science, University of Tehran, Tehran, I.R. IRAN
author
Masoomeh
Azizi
Department of Chemistry, University of Alzahra, Tehran, I.R. IRAN
author
Peshman
Zarabadi
School of Chemistry, College of Science, University of Tehran, Tehran, I.R. IRAN
author
text
article
2011
eng
3,4-ِDihydropyrano[c]chromene derivatives were synthesized using sulfonic acid functionalized silica (SiO2-Pr-SO3H) as a highly efficient heterogenous solid acid catalyst via one-pot three-component condensation of aromatic aldehydes with malononitrile and 4-hydroxycoumarin in excellent yields.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
59
65
https://ijcce.ac.ir/article_6286_e94b51d65875a6242b6d1e20141ce762.pdf
dx.doi.org/10.30492/ijcce.2011.6286
Structure and Fungicidal Activity of Some Diorganotin(IV) with 2-Thioacetic-5-Phenyl-1,3,4-Oxadiazole and Benzamidophenylalanine
Emad
Yousif
Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, IRAQ
author
Yang
Farina
School of Chemical Science and Food Technology, Faculty of Science and Technology,
University Kebangsaan Malaysia, 43600 Bangi, Selangor, MALAYSIA
author
Abdulbasit
Graisa
School of Chemical Science and Food Technology, Faculty of Science and Technology,
University Kebangsaan Malaysia, 43600 Bangi, Selangor, MALAYSIA
author
Nadia
Salih
School of Chemical Science and Food Technology, Faculty of Science and Technology,
University Kebangsaan Malaysia, 43600 Bangi, Selangor, MALAYSIA
author
Jumat
Salimon
School of Chemical Science and Food Technology, Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 Bangi, Selangor, MALAYSIA
author
text
article
2011
eng
New diorganotin(IV) complexes of the type Ph2SnL2, Bu2SnL2 and Me2SnL2 of the ligands 2-thioacetic-5-phenyl-1,3,4-oxadiazole (HL1) and benzamidophenylalanine (HL2). Have been synthesized and characterized by physico-chemical techniques such as (elemental analysis, and electrolytic conductance) and spectral UV-Visible, IR and 1H, 13C and 119Sn NMR). Monomer structures for the complexes, bidentate and octahedral geometry was proposed for the prepared complexes. Preliminary in vitro tests for fungicidal activity show that all prepared compounds display good fungicidal activity to Gibberela, Cercospora arachidicola, Physolospora piricola and Fusarium oxysporum. Moreover, the Ph2Sn(L2)2 shows a higher fungicide activity than diorganotin carboxylate.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
67
72
https://ijcce.ac.ir/article_6287_fb3ed92cd09c53ee47cb3ae56bed4ba1.pdf
dx.doi.org/10.30492/ijcce.2011.6287
HNO3/N,N-Diethylethanaminium-2-(Sulfooxy)Ethyl Sulfate as an Efficient System for the Regioselective of Aromatic Compounds
Farajollah
Mohanazadeh
Institute of Industrial Chemistry, Iranian Research Organization fro Science and Technology, Tehran, I.R. IRAN
author
Sakineh
Rahimi
Institute of Industrial Chemistry, Iranian Research Organization fro Science and Technology, Tehran, I.R. IRAN
author
text
article
2011
eng
N,N-diethylethanaminium-2-(sulfooxy) ethyl sulfate was synthesized and used as an efficient, green, and recyclable catalyst and solvent for the nitration of aromatic compounds by nitric acid at 80oC
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
73
77
https://ijcce.ac.ir/article_6288_ca1523263edeecebc9db98749595023a.pdf
dx.doi.org/10.30492/ijcce.2011.6288
Density and Temperature Dependencies of Liquid Surface Tension
Haniyeh
Alizadeh Osgouei
Faculty of Chemistry, Sharif University of Technology, P.O. Box 11365-9516 Tehran, I.R. IRAN
author
Gholam Abbas
Parsafar
Faculty of Chemistry, Sharif University of Technology, P.O. Box 11365-9516 Tehran, I.R. IRAN
author
Hamed
Akbarzadeh
Faculty of Chemistry, Sharif University of Technology, P.O. Box 11365-9516 Tehran, I.R. IRAN
author
text
article
2011
eng
In this paper the density and temperature dependencies of surface tension are investigated. Using the Lennard-Jones (12,6), as an effective pair interaction potential, a linear expression is derived for isotherms of g /r2 versus r2 for some normal and ChloroFluoroCarbons (CFCs) fluids, where is surface tension and r = 1/v is molar density. The linearity behavior of the derived equation is well fitted onto the experimental data of surface tension for monatomic, diatomic, nonpolar, polar, hydrogen-bonded and chlorofluorocarbons. In addition, the temperature dependence of surface tension for 20 different fluids is examined, in which the contributions of both terms of the average effective pair potential to the g are determined. For all liquids investigated in this work, surface tension increases with density except for water. The surface tension of water for isotherms within 280-300 K decreases with density, whereas increases within the range of 310-320 K.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
79
90
https://ijcce.ac.ir/article_6289_3ab43b165bca4821ffea5b14a9d89797.pdf
dx.doi.org/10.30492/ijcce.2011.6289
Turbulent Events and Gas-Side Mass Transfer Coefficients in a Wavy Air-Water Stratified Flow
Mohsen
Nasr Esfahany
Faculty of Chemical Engineering, Isfahan University of Technology, Isfahan, I.R. IRAN
author
Nazi
Amanatchi
Faculty of Chemical Engineering, Isfahan University of Technology, Isfahan, I.R. IRAN
author
text
article
2011
eng
Turbulence structure on the gas side of a wavy stratified flow was experimentally investigated in a near horizontal 18.7 cm (H) 10 cm (W) 5.5m (L) rectangular duct.By applying the Variable Interval Time Averaging (VITA) technique to the hot wire anemometer measurements frequency of occurrence of turbulent events were detected near the air-water interface. Experimental results showed that frequency of occurrence of turbulent events over the waves increased with the interfacial shear at the interface. Mass transfer coefficients were calculated making use of eddy cell model and calculated turbulent event frequencies. Predicted mass transfer coefficients show good agreement with experimental correlation. Conditional averages of turbulent events were obtained by applying VITA technique to the measured instantaneous velocities. Despite near wall region, both ejection and sweep can initiate turbulent event at the interface.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
91
99
https://ijcce.ac.ir/article_6290_475b3369bd84c934c01075fe5efd922f.pdf
dx.doi.org/10.30492/ijcce.2011.6290
Five-Zone Simulating Moving Bed for Ternary Separation
Hayat
Khan
Department of Chemical Engineering, N-WFP University of Engineering & Technology,
Peshawar, 25000, PAKISTAN
author
Mohammad
Younas
Department of Chemical Engineering, N-WFP University of Engineering & Technology,
Peshawar, 25000, PAKISTAN
author
text
article
2011
eng
Five-zone Simulating Moving Bed (SMB) system, designed for ternary separation, is a modified form of standard four-zone SMB which is only effective in binary separation. It was reported in literature that the five-zone SMB separates the extract-II stream with a lower purity value than that of raffinate and extract-I streams. To address this issue, five zone SMB was designed, using safety margin method for the separation of a ternary amino acid mixture comprises of methionine, phenylalanine and tryptophan having linear isotherms values. The operating conditions at fixed zone-I flow rate were calculated by using triangle theory and the developed mathematical model was run for the simulation studies with Aspen Chromatography vis 12.1. (2004) simulator. The simulation results of the 2-extract five-zone SMB system were illustrated for the effect of change in zone safety factor (β2, β3 and β4) values on the separation performance (product purity and recovery) and on solutes band propagation behavior at cyclic steady state.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
101
117
https://ijcce.ac.ir/article_6291_90d057e97a9718010ff24443c2997dcf.pdf
dx.doi.org/10.30492/ijcce.2011.6291
Improving Cyclone Efficiency by Recycle and Jet Impingement Streams
Sepideh
Akhbarifar
Faculty of Chemical Engineering, Iran University of Science and Technology,
P.O. Box 16846-13114 Tehran, I.R. IRAN
author
Mansour
Shirvani
Faculty of Chemical Engineering, Iran University of Science and Technology,
P.O. Box 16846-13114 Tehran, I.R. IRAN
author
Sorood
Zahedi
Modeling and Control department, Process Development Division, Research Institute of Petroleum Industry (RIPI), P.O. Box 14665-1998 Tehran, I.R. IRAN
author
Mohammad Reza
Zahiri
Research and Development Section, Abadan Oil Refining Co., P.O. Box 555 Abadan, I.R. IRAN
author
Yousef
Shamsaii
Research and Development Section, Abadan Oil Refining Co., P.O. Box 555 Abadan, I.R. IRAN
author
text
article
2011
eng
In this paper a new process is presented for improving efficiency of cyclone de-dusting systems. The cyclone is coupled with a specially designed cylindrical chamber which includes a rotating tube inside it with air impinging nuzzles, drilled on the peripheral surface of the tube. The nuzzles help in pushing and throwing the particles to the outer radius distances during downward flow of dust included air stream inside the chamber. In this way dust particles will become concentrated near the surface of the cylindrical chamber which is then collected from a recycling stream, taken from the higher radius zone of the chamber in the lower part and passed through a cyclone for dust removal. The exhaust dusty flow of the cyclone is also recycled to the jet-impingement chamber for further de-dusting. Experiments were conducted on the apparatus by feed stream input to the chamber in such a way that the performances of chamber alone can be investigated with respect to the three variables; feed stream, recycle stream and jet-impingement stream.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
119
124
https://ijcce.ac.ir/article_6292_826b0b3b27318f3745d4897b41227f13.pdf
dx.doi.org/10.30492/ijcce.2011.6292
Adaptive Predictive Controllers Using a Growing and Pruning RBF Neural Network
Mohammad Reza
Jafari
Department of Automation and Instrumentation, Petroleum University of Technology, Tehran, I.R. IRAN
author
Karim
Salahshoor
Department of Automation and Instrumentation, Petroleum University of Technology, Tehran, I.R. IRAN
author
text
article
2011
eng
An adaptive version of growing and pruning RBF neural network has been used to predict the system output and implement Linear Model-Based Predictive Controller (LMPC) and Non-linear Model-based Predictive Controller (NMPC) strategies. A radial-basis neural network with growing and pruning capabilities is introduced to carry out on-line model identification.An Unscented Kalman Filter (UKF) algorithm with an exponential time-varying forgetting factor has been presented to enable the neural network model to track any time-varying process dynamic changes. An adaptive NMPC has been designed based on the sequential quadratic programming technique. The paper makes use of a dynamic linearization approach to extract a linear model at each sampling time instant so as to develop an adaptive LMPC. The servo and regulating performances of the proposed adaptive control schemes have been illustrated on a non-linear Continuous Stirred Tank Reactor (CSTR) as a benchmark problem. The simulation results demonstrate the capability of the proposed identification strategy to effectively identify compact, accurate and transparent model for the CSTR process. It is shown that the proposed adaptive NMPC controller presents better improvement with faster response time for both servo and regulatory control objectives in comparison with the proposed adaptive LMPC, an adaptive generalized predictive controller based on Recursive Least Squares (RLS) algorithm and well-tuned PID controllers.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
125
138
https://ijcce.ac.ir/article_6293_0261dd5ed36985ef55a1e4c25f8d31d2.pdf
dx.doi.org/10.30492/ijcce.2011.6293
gpALIGNER: A Fast Algorithm for Global Pairwise Alignment of DNA Sequences
Mostafa
Hadian Dehkordi
Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics (IBB), University of Tehran, I.R. IRAN
author
Ali
Masoudi-Nejad
Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics (IBB), University of Tehran, I.R. IRAN
author
Morteza
Mohamad-Mouri
Department of Mathematics, Statistics and Computer Science, College of Science, University of Tehran, Tehran, I.R. IRAN
author
text
article
2011
eng
Bioinformatics, through the sequencing of the full genomes for many species, is increasingly relying on efficient global alignment tools exhibiting both high sensitivity and specificity. Many computational algorithms have been applied for solving the sequence alignment problem. Dynamic programming, statistical methods, approximation and heuristic algorithms are the most common methods applied to this problem. We introduce gpALIGNER, a fast pairwise DNA-DNA global alignment algorithm. gpALIGNER uses similar score schema with DIALIGN-T to produce the final alignment. It also uses the concept of “spaced seeds” to determine locally aligned subsequences which construct semi-global alignment as the preliminaries of global alignment computation. This enables gpALIGNER to have the precision provided by the DIALIGN-T algorithm in considerably less time and space complexities. We performed benchmarking of our approach based on numerous datasets from standard benchmarking databases and real sequences of NCBI database where gpALIGNER performed three times faster than DIALIGN-T. gpALIGNER is a new alternative for having sensitivity and selectivity of DIALIGN-T but with less computational cost.
Iranian Journal of Chemistry and Chemical Engineering
Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
1021-9986
30
v.
2
no.
2011
139
146
https://ijcce.ac.ir/article_6294_34cbf3b93476d717c90c7c39e1515702.pdf
dx.doi.org/10.30492/ijcce.2011.6294