eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2241
2248
3773
Synthesis, characterization and biological screening of different carbamates derived from 7-hydroxy-4-methyl-2H-1-benzopyran-2-one
Aziz-ur-Rehman Aziz-ur-Rehmana
azizryk@yahoo.com
1
S. Naeem
2
M. A. Abbasi
3
S. Rasool
4
K. Nafeesa
5
I. Ahmed
6
S. Afzal
7
Department of Chemistry, Government College University, Lahore-54000, Pakistan
Department of Chemistry, Government College University, Lahore-54000, Pakistan
Department of Chemistry, Government College University, Lahore-54000, Pakistan
Department of Chemistry, Government College University, Lahore-54000, Pakistan
Department of Chemistry, Government College University, Lahore-54000, Pakistan
Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur-63100, Pakistan
Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur-63100, Pakistan
A facile and environmentally benign series of carbamates derived from coumarin were synthesizedThe synthesis of 7-hydroxy-4-methyl-2H-1-benzopyran-2-one(3)was carried out by gearing up resorcinol (1) and ethyl acetoacetate (2)in a strong acidic media. Carbamates, 7and8,were synthesized by reacting phenylchloroformate (4) with substituted aliphatic amines, 5 and6, under dynamic pH control in aqueous media in the presence of Na2CO3 solution. The molecules 37 and 8 werebrominated to 3a7a and8a. The molecules 99a10 and 11 were synthesized by further reaction of 3 and3a with the electrophilic carbamates, 77a and 8 in a polar aprotic solvent using LiH as an activator. Finally, the compound 12 was synthesized by the nitration of 10. Structures of all the compounds were determined by IR, 1HNMR, 13C-NMR and EI-MS spectroscopic techniques. The bioactivity results of all the synthesized compounds against four gram-negative and two gram-positive bacteria showed that the synthesized coumarin derivatives exhibited moderate to good %age inhibition activity.
https://scientiairanica.sharif.edu/article_3773_a73d5618d9523fce8413199e9a5ccc5b.pdf
7-Hydroxy-4-methylcoumarin
Carbamates
Substituted aliphatic amine
Antibacterial activity
Spectral analysis
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2249
2253
3774
A green and simple approach toα-acyloxycarboxamides
Sahar Dezfooli
s.dezfooli@srbiau.ac.ir
1
Mohammad Mahmoudi Hashemi
2
Young Researchers and Elites club, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Chemistry, Science and Research Branch Islamic Azad University, Tehran, Iran
A mild and sustainable three component passerini reaction, in biodegradable deep eutectic solvent based choline chloride:urea (1:2) is described. The reaction proceeds at room temperature involving substituted benzaldehyde, benzoic acid and cyclohexyl isocyanide, with short reaction time and good to excellent yields (65-90%) without tedious workup
https://scientiairanica.sharif.edu/article_3774_5fb95d5147d8ae6d7ea86e92a34df4c0.pdf
passerini reaction
α-acyloxycarboxamides
deep eutectic solvent
choline chloride
Green chemistry
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2254
2261
3775
One-pot multi-component synthesis of 1,2,4,5-tetrasubstituted imidazoles using sulfonic acid-functionalized pyridinium chloride as an efficient and recyclable catalyst
Ahmad Reza Moosavi-Zare
moosavizare@yahoo.com
1
Zhila Asgari
2
Abdolkarim Zare
3
Mohammad Ali Zolfigol
4
Department of Chemistry, University of Sayyed Jamaleddin Asadabadi, Asadabad, 6541835583, Iran
Faculty of Chemistry, Bu-Ali Sina University, Hamedan, 6517838683, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Faculty of Chemistry, Bu-Ali Sina University, Hamedan, 6517838683, Iran
Sulfonic acid-functionalized pyridinium chloride ionic liquid {[Pyridine–SO3H]Cl} can effectively promote the one-pot multi-component condensation reaction between benzil, aldehydes, primary amines and ammonium acetate under solvent-free conditions at 100 ºC to give the desired 1,2,4,5-tetrasubstituted imidazoles, in high yields and short reaction times.
https://scientiairanica.sharif.edu/article_3775_ea008e137df47cd8f8d0befac0e4744a.pdf
1
2
4
5-tetrasubstituted imidazole
sulfonic acid-functionalized pyridinium chloride {[Pyridine–SO3H]Cl}
Ionic liquid
Solvent-free
Benzil
primary amine
aldehyde
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2262
2270
3776
A theoretical study of the structural, vibrational, and topological properties of charge distribution of the molecular complexes between furan and zeolites
L. Zeidabadinejad
1
M. Dehestani
lswugkwt@scientiaunknown.non
2
Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, P.O. Box 76169, Iran.
Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, P.O. Box 76169, Iran
The main interaction between furan and zeolites leads to formation of a hydrogen bond between the O atom of furan and the OH groups of zeolites. The present work reports a theoretical study about the structural, vibrational, and topologic properties of charge distribution of the molecular complexes between furan and the series of acids sites of zeolites. The calculated structural parameters are the highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital energy (ELUMO), energy gap (E), hardness (), softness (S), absolute electronegativity (), electrophilicity index (!), and the fractions of electrons transferred (N) from zeolites molecules to furan. We show that the H atom of the bridged OH group of zeolite clusters attacks the O atom of furan.
https://scientiairanica.sharif.edu/article_3776_101935dddc53853ec189b0c68c5d4ef7.pdf
Furan
Zeolites
DFT
Fukui function
Charge transfer
AIM
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2271
2281
3777
Characterization and application of pyrazinium di(hydrogen sulfate) as a highly efficient catalyst for synthesis of 14-aryl-14H-dibenzo[aj]xanthenes, 9-aryl-1,8-dioxo-octahydroxanthenes and 1-amidoalkyl/carbamatoalkyl-2-naphthols
Abdolkarim Zare
abdolkarimzare@yahoo.com
1
Salimeh Ahmadi
2
Fereshteh Abi
3
Tahereh Hekmat-Zadeh
4
Maria Merajoddin
5
Marzieh Hatami
6
Meisam Keshtkar
7
Ardeshir Khazaei
8
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Department of Chemistry, Payame Noor University, PO BOX 19395-3697, Tehran, Iran
Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran
In this work, characterization of Brønsted acidic ionic liquid namely pyrazinium di(hydrogen sulfate){PyH2(HSO42} using 1H and 13C NMR, mass, thermogravimetry(TG) and derivative thermogravimetry(DTG) data is achieved. Afterward, it is used as a highly efficient, green and homogeneous catalyst to promote the following organic transformations under solvent-free conditions: (i) the synthesis of 14-aryl-14H-dibenzo[aj]xanthenesfrom2-naphthol and arylaldehydes, (ii) the preparation of 9-aryl-1,8-dioxo-octahydroxanthenes by the reaction of dimedone (5,5-dimethyl-1,3-cyclohexanedione)with arylaldehydes, (iii) the synthesis of 1-amidoalkyl/carbamatoalkyl-2-naphthols by the condensation of 2-naphthol with aromatic aldehydes and amide derivatives/alkyl carbamates.
https://scientiairanica.sharif.edu/article_3777_fa2bc8889d77c538f26a160f6b758da1.pdf
Brønsted acidic ionic liquid
Pyrazinium di(hydrogen sulfate){PyH2(HSO42}
14-Aryl-14H-dibenzo[aj]xanthenes
9-Aryl-1,8-dioxo-octahydroxanthene
1-Amidoalkyl-2-naphthol
1-Carbamatoalkyl-2-naphthol
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2282
2289
3778
Nanoporous MCM-41-SO3H as an efficient catalyst for chalcones and dibenzylidene alkanones synthesis via solvent-free aldol-condensation reaction
Elham Neyestani-Naeeni
1
M. Reza Naimi-Jamal
naimi@iust.ac.ir
2
Research Laboratory of Green Organic Synthesis & Polymers, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, IRAN
Research Laboratory of Green Organic Synthesis & Polymers, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, IRAN
A one-pot and simple method for the solvent-free synthesis of chalcones and dibenzylidene alkanones, catalyzed by heterogeneous and nanoporous MCM-41-SO3H catalyst is reported. The products were afforded in most cases with excellent yields
https://scientiairanica.sharif.edu/article_3778_eb19d392c7d0913d2dd128fc54fa3436.pdf
MCM-41-SO3H
Heterogeneous catalyst
The Aldol condensation
Solvent-free grinding
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2290
2297
3779
Electrical and electrochemical properties of expanded graphite filled polythiophene nanocomposites
Gholamreza Kiani
g.kiani@tabrizu.ac.ir
1
Mohammad Mahmoudi
2
Arash Selk Ghafari
3
School of Engineering-Emerging Technologies, University of Tabriz, Tabriz, Iran
School of Engineering-Emerging Technologies, University of Tabriz, Tabriz, Iran
School of Engineering-Emerging Technologies, University of Tabriz, Tabriz, Iran
In this study, graphite nanosheets were prepared by powdering expanded graphite with sonication in aqueous alcoholic solution. A facile process for the synthesis of expanded graphite filled polythiophene (PTh/EG) conducting composites was developed. The nanocomposites were fabricated via chemical polymerization of thiophene monomer in the presence of expanded graphite nanosheets in various proportions. Nanocomposites were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Scanning Tunneling Microscopy (STM), X-ray diffraction (XRD), cyclic voltammetry (CV) and electrical conductivity measurements. . SEM observations from cross-sections of EGwere performed to understand the microstructure occurrence during interpenetration.Electrical conductivity of PTh/EG was notably enhanced by the introduction of EG. The composite exhibited good electrical conductivity of 125 Scm-1 when the EG content was 0.5 wt %. CV is the most commonly used technique for evaluation of electrochemical properties of a film on the electrode surface.The composites also showed excellent electrochemical reversibility at the scan rate of 50 mVs-1 and maximum reversible electrochemical response was almost unchanged even up to 100 cycles. The stability of oxidation and reduction peaks of nanocomposites in cyclic voltammetry up to 100 cycles show that obtained nanocomposites are very appropriate to be used in rechargeable batteries
https://scientiairanica.sharif.edu/article_3779_ba87aa2eb3322bcbb07bcde4bb080d84.pdf
Polythiophene
Nanocomposite
Expanded graphite
Electrical properties
Charge capacity
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2298
2308
3780
Crystal structure, spectroscopic characterization, and computational study of two new 4-aminobenzoic acid derived Schi base ligands
R. Kia
1
H. Kargar
2
Department of Chemistry, Sharif University of Technology, Tehran, P.O. Box 11155-3516, Iran
Department of Chemistry, Payame Noor University, Tehran, P.O. Box 19395-3697, Iran
Two new Schi base ligands, (E)-4-(3-ethoxy-2-hydroxybenzylideneamino) benzoic acid (L1) and (E)-4-(3-methoxy-2-hydroxy-benzylideneamino)benzoic acid (L2), were synthesized and characterized by elemental analyses, FT-IR, NMR spectroscopy and single-crystal X-ray diraction analysis. The compound, L1, was crystallized in the triclinic system, space group P - 1, with a = 4:9897(3) A, b = 6:9109(5) A, c = 20:7694(15) A, = 83:690(4), = 84:855(4), = 78:698(4), V = 696:35(8) A3, and Z = 2. The compound L2 was crystallized in the orthorhombic system, non-centerosymmetric space group, P212121, with a = 4:7824(4) A, b = 10:2031(11) A, c = 30:516(3) A, V = 1489:0(3) A3, and Z = 4. Both L1 and L2 display a trans-conguration about the C=N double bond. The Density Functional Theory (DFT) and the Time-Dependent Density Functional Theory (TD-DFT) were used to study the ground state properties (molecular orbitals), and interpret the absorption spectra of these ligands, respectively. Electronic Dierence Density Maps (EDDMs) were calculated from the TD-DFT study, indicating the change of electron density in the singlet excited states.
https://scientiairanica.sharif.edu/article_3780_a4feb7e28dde21fb66342119db74e1e1.pdf
Schi base ligands
Diimine ligands
N,O-donor ligands
X-ray diraction
Density Functional Theory (DFT)
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2309
2318
3781
Enantioselectivity of lipase B from Candida Antarctica in the transesterification reaction of (RS)-1-phenylethanol and S-ethyl thiooctanoate; a density functional study
Mehdi Irani
m.irani@uok.ac.ir
1
Saied Heydaryan
2
Department of Chemistry, University of Kurdistan, P. O. Box 66177-15177, Sanandaj, Iran
Department of Chemistry, University of Kurdistan, P. O. Box 66177-15177, Sanandaj, Iran
The catalyzed reaction of (RS)-1-phenylethanol and S-ethyl thio octanoate by lipase B from Candida Antarctica is studied, using density functional theory. Quantum mechanics cluster approach is used to model the enzyme’s active site. The results show that the catalytic triad amino acids of the enzyme do not abstract the alcoholic proton of 1-phenylethanol before a nucleophilic attack from the alcohol to the ester. A two-step mechanism is proposed for the reaction of theR-enantiomer of the alcohol with the ester. However, the results show no path for theS-enantiomer. We showed that the enantioselectivity of the enzyme is due to the different hydrogen-bonding patterns of the two enantiomers of the alcohol in the enzyme’s active site. The OH group of theR-enantiomer is directed toward Ser-105. While, the OH group of theS-enantiomer is far from Ser-105 and is directed toward Thr-40.
https://scientiairanica.sharif.edu/article_3781_d8cfbda870a69be21deaf7feba06e0b6.pdf
lipase B
DFT
quantum cluster
enantioselectivity
Transesterification
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2319
2325
3782
Synthesis of dihydropyrido[2,3-d]pyrimidine derivatives in the presence of sulfonic acid functionalized SBA-15 and the study of their antimicrobial activities
Ghodsi Mohammadi Ziarani
gmziarani@hotmail.com
1
Narges Hosseini Nasab
2
Mahshid Rahimifard
3
Alireza Badiei
abadiei@khayam.ut.ac.ir
4
Ali Abolhassani Soorki
5
Department of Chemistry, Alzahra University, Vanak Square, Tehran, Iran
Department of Chemistry, Alzahra University, Vanak Square, Tehran, Iran
Department of Chemistry, Alzahra University, Vanak Square, Tehran, Iran
School of Chemistry, College of Science, University of Tehran, Tehran, Iran
ACECR-Research Institute of Applied Sciences, Shahid Beheshti University, Tehran, Iran
SBA-Pr-SO3H was used as green and recyclable catalyst for the synthesis of dihydropyrdo[2,3-d]pyrimidine derivatives by three component one-pot reaction between 6-amino-1,3-dimethyl uracil, aromatic aldehydes and 1,3-dicarbonyl compounds under reflux conditions. Some of synthesized dihydropyrido[2,3-d]pyrimidines were showed antimicrobial activities against some fungi and gram positive and negative bacteria
https://scientiairanica.sharif.edu/article_3782_85542b3197dd562bfb1fe35a8dcd3b3d.pdf
6-amino-1
3-dimethyl uracil
pyrido[2
3-d]pyrimidine
1
3-dicarbonyl compounds
SBA-Pr-SO3H
Multicomponent reaction
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2326
2331
3783
A Novel bi-SO3H functional DABCO derived ionic liquid based on nitrate ion as a versatile reagent for rapid mono-nitration of phenols and naphthols
Firouzeh Nemati
fnemati@semnan.ac.ir
1
Hossein Lurestani pour
2
Department of Chemistry, Semnan University, Semnan, Iran
Department of Chemistry, Semnan University, Semnan, Iran
The mono nitration of phenols and naphthols has been reported in high yields and short reaction times using the task specific ionic liquid based on nitrate ion, 1,4-bis(4-sulfobuthyl)-1,4-diazabicyclo[2.2.2]octane di nitrate, as reagent without acid co-catalyst at mild condition. The reagent could be recovered and reused several times without significant lose of reactivity
https://scientiairanica.sharif.edu/article_3783_322210788af2b4065ffe72a3f72c140f.pdf
Task specific ionic liquid
Green chemistry
Sultone
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2332
2340
3784
Nano SbCl5.SiO2: An efficient and heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-one (thione)derivatives under solvent-free conditions
A. Bamoniri
bamoniri@kashanu.ac.ir
1
B. F. Mirjalili
2
H. Karbasizadeh
3
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R.Iran
Department of Chemistry, Faculty of Science, Yazd University, Yazd, I.R.Iran
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R.Iran
A green approach for efficient and rapid synthesis of biologically active substituted 3,4-dihydropyrimidin-2(1H)-one(thione) derivatives using nano SbCl5.SiO2as a heterogeneous catalyst under solvent-free conditions is reported. The catalyst was characterized by FT-IR, XRD, SEM, TEM and TG-DTG analysis. Compared to the classical reactions, this method consistently has advantages of excellent yields, simple operation, short reaction time, and the avoidance of the use of organic solvents and eco-friendly protocol.
https://scientiairanica.sharif.edu/article_3784_1f7da7153a68b674792c971c76a15efb.pdf
Nano SbCl5.SiO2
Heterogeneous acid catalyst
3
4-Dihydropyrimidin-2(1H)-ones(thiones)
solvent-free conditions
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2341
2349
3785
Pd/LaxSr1-xFeO3 perovskite nanocatalysts for selective catalytic reduction of NOx by hydrogen
A. Nemati
1
A.A. Khodadadi
2
Y. Mortazavi
mortazav@ut.ac.ir
3
A. Alinezhadchamazketi
4
Catalysis and Nanostructured Materials Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Catalysis and Nanostructured Materials Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Catalysis and Nanostructured Materials Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Catalysis and Nanostructured Materials Laboratory, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
In this study, LaxSr1-xFeO3 (x = 0, 0.8) perovskite-type catalysts were prepared by gel combustion method and then 1.0 wt% palladium was loaded on them by a dry impregnation. The catalysts were characterized by XRD, SEM, H2-TPR, O2-TPD, NO-TPD and BET surface area techniques.H2-TPR profiles of the Pd/perovskite catalyst shows the reduction of Pd at around 140˚C which facilitates the reduction of NO in the H2-SCR. TPD results reveal that the substitution of Sr in the perovskites structure remarkably decreases the oxygen mobility and increases the NO adsorption. The H2-SCR of NO on the catalysts was performed in a temperature-programmed reaction apparatus in the presence of oxygen.The effect of carbon monoxide in the feed on H2-SCR was also investigated. The PLSFOcatalyst (1.0 wt% Pd/La0.8Sr0.2FeO3 shows the highest NO conversion and N2 selectivity at a moderate temperature of 190oC.
https://scientiairanica.sharif.edu/article_3785_1aecec643c5c6ee5609ee674cc2b221c.pdf
Hydrogen
NO
Palladium
perovskite
Selective Catalytic Reduction
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2350
2357
3786
An Efficient Procedure for the Production of trans-4-Hydroxy-L-proline Using Recombinantly Expressed Proline Hydroxylase
Jiaojiao Chen
1
Dandan Gu
2
Tianyun Li
3
Jiansong Ju
jujiansong@hotmail.com
4
Zhangwei Xue
5
Cunhui Li
6
Jin Yan
7
Jinxiu Zhang
8
Li-an Wang
9
College of Life Sciences, Hebei Normal University, No. 20, Road East of 2nd Ring South, Yuhua District, Shijiazhuang, 050024, China
College of Life Sciences, Hebei Normal University, No. 20, Road East of 2nd Ring South, Yuhua District, Shijiazhuang, 050024, China
College of Life Sciences, Hebei Normal University, No. 20, Road East of 2nd Ring South, Yuhua District, Shijiazhuang, 050024, China
College of Life Sciences, Hebei Normal University, No. 20, Road East of 2nd Ring South, Yuhua District, Shijiazhuang, 050024, China
Hebei Brant Pharmaceutical Co., LTD, Mayu Industrial Park, Jinzhou, 052260, China
Hebei Brant Pharmaceutical Co., LTD, Mayu Industrial Park, Jinzhou, 052260, China
Beijing Hongyisifang Radiation Technology Co., LTD, Beijing, 101113, China
College of Life Sciences, Hebei Normal University, No. 20, Road East of 2nd Ring South, Yuhua District, Shijiazhuang, 050024, China
College of Life Sciences, Hebei Normal University, No. 20, Road East of 2nd Ring South, Yuhua District, Shijiazhuang, 050024, China
Due to the codon usage and high G+C contentof thetrans-4-proline-L-hydroxylase gene from the Dactylosporangium sp.strain RH1, the whole gene was optimized and cloned into several vectors for expression. In biotransformations with resting cells, the activity of the enzyme was investigated. The in-house modified plasmid pet-M-3C was found to yield the highest enzymatic activity. Additionally, after the primary fragment screening, the conversion efficiency of fragment 1-257 aa was enhanced from 76.60% to 88.97% compared with the full-length proline 4-hydroxylase within 60 h; we also found that truncation of the gene improved the solubility of the encoded protein.After optimizing the various induction conditions with respect to the enzymatic activity of the engineered strain, including the concentration of the inducer IPTG, the cell density before the inducer was added, the induction temperature and the induction time, the conversion efficiency was more than 97%within 48 h.
https://scientiairanica.sharif.edu/article_3786_73f15af548506a6e3236da0e135bbb7f.pdf
proline
hydroxy-L-proline
proline hydroxylases
optimization
conversion efficiency
truncation
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2358
2372
3787
Optimal operation of a divided-wall column with local operating condition changes
Alireza Arjomand
1
Mohammad Ali Fanaei
fanaei@um.ac.ir
2
Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
The aim of this paper is optimal operation of a divided-wall column (DWC) based on self-optimizing control (SOC). By now, the proposed SOC methods have been based on linearization of the process. The novelty of this paper is to overcome this shortcoming of the local optimality of SOC. Theoretically, changes in optimal sensitivity matrix from nominal design, due to changes in operating condition, make SOC deviate from steady state optimality. These deviations from optimal operation, in already available SOC structures, have to be counteracted by optimization layer in the control structure hierarchy which involves solving a large nonlinear optimization problem online. The proposed method in this paper solves this problem with modeling optimal sensitivity matrix with Takagi-Sugeno fuzzy inference. This fuzzy inference system is tuned offline. The proposed method is dynamically validated and compared with conventional SOC. The results showed that conventional SOC had high value of loss and deviated from optimal operation. However, in the same operating condition, the proposed method with the aid of Takagi-Sugeno fuzzy inference system, which involves online calculation of weighted average of some linear function, imposed small loss, made DWC track optimal trajectory and removed the need for online solving large nonlinear optimization problem.
https://scientiairanica.sharif.edu/article_3787_eb723f601e8a68360304cdf51cdd63c4.pdf
optimal operation
divided-wall column
plantwide control
self -optimizing control
Takagi-Sugeno fuzzy inference system
eng
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
2015-12-01
22
6
2373
2378
3788
Experimental Observation and Mathematical Modeling of Immiscible Displacement in oil Wet Reservoirs
Ehsan Kamari
kamarie@ripi.ir
1
Department of Petroleum Engineering, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
Here, a series of immiscible displacement processes have been performed on fractured porous medium developed on glass micro-models in order to investigate the role of fracture characteristics on oil displacement efficiency during immiscible displacement process. Oil recoveries were determined from image analysis of continuously recorded pictures during different flooding schemes. A clear bypassing of displacing fluid which results in premature breakthrough of injected fluid due to the fracture has been observed. Moreover, the results showed a decrease of oil recovery when fracture's length increased. In contrast, an increase of fracture orientation from flow direction increased oil recovery. Results of this work may be useful for through understanding of immiscible displacement process as well optimal field development plans.
https://scientiairanica.sharif.edu/article_3788_56d02c728e98b393c80b4852a4a336ca.pdf
Breakthrough
Fracture reservoir
Front
Heterogeneous
Immiscible displacement
Oil recovery