Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
DFT/B3LYP Study of Thermochemistry of D-Glucosamine, a Representative Polyfunctional Bioorganic Compound
2925
EN
A.
Pourjavadi
Department of Chemistry,Sharif University of Technology
A.
Fattahi
Department of Chemistry,Sharif University of Technology
M.
Kurdtabar
Department of Chemistry,Sharif University of Technology
Journal Article
2009
05
27
D-glucosamine, as a representative polyfunctional compound, is a bioactive amino sugar. In
this study, the gas phase thermochemical properties of D-glucosamine, including its Metal Ion
Anity (MIA), metal binding sites, Anion Anity (AA), acidity and proton anity, have been
explored, using the Density Functional Theory (DFT) and a 6-311++Gbasis set. The summary
of the MIA and AA results (in kcal/mol????1) are: Li+= 67.6, Na+= 51.1, K+= 37.3, Mg2+=
207.9, Ca2+= 150.4, Zn2+= 251.2, Cl????= 27.4, CN????= 28.0. The acidity values calculated
at dierent sites, including four -OH groups and one -NH2 group, range from 344.0 to 373.0
kcal/mol????1. These results, surprisingly, indicate how drastically the presence of multiple -OH and
-NH2 groups may vary the thermochemical properties of a polyfunctional bioorganic compound,
such as D-glucosamine.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Solid Trichlorotitanium (IV) Tri uoromethanesulfonate TiCl3 (OTf) Catalyzed Highly Ecient Protection of Aldeyhydes as their Acylals at Room Temperature under Solvent-Free Conditions
2926
EN
H.
Firouzabadi
Department of Chemistry,Shiraz University
N.
Iranpoor
Department of Chemistry,Shiraz University
S.
Farahi
Department of Chemistry,Shiraz University
Journal Article
2009
05
27
TiCl3(OTf) catalyzed eciently the protection of aromatic aldehydes with acetic anhydride in
the absence of solvent at room temperature with excellent yields. By this method, aliphatic
aldehydes were also converted to their corresponding acylals, in the presence of a mixture of
acetic anhydride and acetic acid at high yields.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Determination of Reservoir Model from Well Test Data, Using an Articial Neural Network
2927
EN
R.
Kharrat
-------,The Research Center of Petroleum University
Journal Article
2009
05
27
Nowadays, neural networks have a wide range of usage in dierent elds of engineering. In the
present work, this method is used to determine a reservoir model. Model identication, followed
by parameter estimation, is a kind of visual process. Pressure derivative curves showing more
features are usually used to determine the reservoir model based on the shape of the curve
and no calculation is included. So, it is dicult to convert this kind of visual process to an
applicable algorithm for computers. In fact, the model identication is a pattern recognition
which is best done by an Articial Neural Network (ANN). If neural networks were learned
successfully, they would be able to categorize dierent shapes into dierent groups, due to their
visual characterization. So, their use in such a job would seem to be useful. In this work, it is
shown how to train, examine and use neural networks to determine a reservoir model. The input
of an ANN is fty points of the normalized pressure derivative type curve. Each ANN is trained,
based on a specic model, and the output of the ANN is the probability of occurrence of a fed
curve to the related model.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Potentiometric Chromate Quantication Based on Interaction with N, N' Butylen Bis (Saliciliden Iminato) Copper (II)
2928
EN
M.
Mazloum Ardakani
Department of Chemistry,University of Yazd
A.
Sadeghi
Department of Chemistry,University of Kashan
Journal Article
2009
05
27
A new chromate-selective electrode, based on the N, N' butylen bis (saliciliden iminato) copper
(II) complex as the membrane carrier, was developed. The electrode exhibited a good Nernstian
slope of ????28:8 0:5 mV/decade and a linear range of 3:0 10????6 ???? 1:0 10????1 mol.L????1 for
chromate. The limit of detection was 3:0 10????6 mol.L????1. It had a fast response time of 5-10
sec and could be used for more than three months. The selective coecients were determined
by the Fixed Interference Method (FIM). A chromate-selective electrode could be used in the
pH range of 6.5-10.5. It was employed as an indicator electrode for the direct determination of
chromate in real samples.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Mathematical Modeling of a Cross Flow Conveyor Belt Dryer
2929
EN
N.
Kasiri
Department of Chemical Engineering,Iran University of Science and Technology
E.
Mirzahoseinkashani
Department of Chemical Engineering,Iran University of Science and Technology
Journal Article
2009
05
27
The drying of solids in a cross
ow conveyor belt dryer (continuous operation system), in which
particles (thin-layer) move in a wire net conveyor, was theoretically studied. A mathematical
modeling that considers the in
uence of bed porosity and transient terms in the drying process
was developed and the changes in bed porosity and product density with the moisture content of
seeds have been considered. Also, to have a more accurate model, some changes have been made
to the specic surface of the seed. The nite volume method was used to solve, numerically, the
governing conservation equations. The results of the moisture content of the material (yellow
corn kernel), residence time and conveyor length are presented and analyzed in order to modify
the model, according to bed porosity, product density and the specic surface changes of the
seed. This model can predict humidity ratio, the temperature of air, moisture content and the
temperature of the material throughout the drying process.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Al(HSO4)3 Mediated for the Preparation of Primary Carbamates under Solvent-Free Conditions
2930
EN
A.R.
Modarresi-Alam
Department of Chemistry,University of Sistan and Baluchestan
M.
Nasrollahzadeh
Department of Chemistry,University of Sistan and Baluchestan
F.
Khamooshi
Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran
Journal Article
2009
05
27
Al(HSO4)3 as an acidic salt, i.e. a mild, convenient and ecient reagent, was applied for<br />the conversion of compounds containing a hydroxyl group to primary carbamates, at room<br />temperature, with high yield and purity and without any epimerization, under solvent-free<br />conditions.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Essential Components of an Integrated Data Mining Tool for the Oil and Gas Industry with an Example Application in the DJ Basin
2931
EN
Sh.D.
Mohaghegh
Department of Petroleum and Natural Gas Engineering,West Virginia University
Journal Article
2009
05
27
Data mining seems to be the new buzz word. During the past several years many industries
other than the oil and gas industry have realized the potential benets of da5ta mining and
have established sophisticated operations in order to implement this exciting technology in their
respective organizations. Data mining is not new. It has been around for many years. What
is new about its current implementation is the incorporation of machine learning techniques.
The oil and gas industry has become familiar with machine learning techniques since the early
1990s. Neural networks, genetic optimization and fuzzy logic have been used in numerous
applications, from well log interpretations to hydraulic fracturing optimization. Therefore, the
new interest in data mining in this industry is not surprising. The industry is at its peak state
for beneting from what data mining has to oer, thanks to an abundance of digital data. A
word of caution is in order, which is the main motivation behind writing this paper. As with
many other new tools and technologies, the term \Data Mining" can be, and is currently being,
misused on several occasions. In this paper, an attempt has been made to answer questions such
as; what is Data Mining? How can it be accomplished? What are the essential components of
an integrated data mining process and what would be the benets of such a process? In addition
to answering questions such as those mentioned above, this paper will provide a road map (a
set of guidelines) for a successful data mining project. Finally, the paper concludes by applying
the presented guidelines to a hydraulic fracturing data set in the DJ basin of the United States
Rockies for a data mining study.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Eect of Permeable Contacts on the Performance of a Gas-Oil Gravity Drainage Mechanism in a Stack of Matrix Blocks
2932
EN
S.
Nejadi
Department of Reservoir Engineering,Iranian Offshore Oil Company
V.A.
Sajjadian
-------,Arvandan Oil and Gas Producing Company
Journal Article
2009
05
27
In the gas invaded zone of a well fractured carbonate reservoir, gravity drainage mechanism
plays the main role in expelling oil from dense, low permeability matrix blocks. Whenever the
active mechanism is gravity drainage, reinltration and capillary continuity phenomena notably
in
uence the rate and amount of oil recovery from matrix blocks. In the current research, six
experiments were performed to study the eects of a permeable contact area (between two blocks
located on top of each other) on reinltration and capillary continuity. Two of the experiments
were performed using single blocks of 30 and 60 cm height, whilst others were stacks of two 30
cm high blocks. Results of the experiments reveal that, by increasing the permeable contact area
between blocks, due to capillary continuity and reinltration, there will be more communication
between them, consequently, both ultimate oil recovery and production rate will improve. It is
also noticeable that, if the permeable contact area is approximately greater than 20% of the total
block surface area, the stack of blocks behaves analogous to a unique block with a height equal
to that of the stack. The outcome of the present work, along with data from other studies, such
as the eects of horizontal fracture apertures and fracture dips, can be utilized in order to have
a better understanding of block to block eects. By this, the modeling of the gravity drainage
mechanism, while injecting gas into fractured carbonate formations, would be improved.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Determination of Traces of 2,4-Dichlorophenoxy Acetic Acid in Environmental Samples
2933
EN
N.
Maleki
Department of Chemistry,Shiraz University
A.
Safavi
Department of Chemistry,Shiraz University
Journal Article
2009
05
27
drop electrode in aqueous media and in the presence of Britton-Robinson buer as the electrolyte.
In this study, the electroinactive 2,4-D was rst converted to electroactive nitrated 2,4-D.
Subsequent determination was carried out by dierential pulse polarography. Under optimum
conditions (pH = 11; = 90 mV s????1; modulation amplitude = 120 mV), the relative standard
deviation was 4.5% and limit of detection in terms of nitrated 2,4-D was 5 g L????1 (1:8810????8 M)
with linear concentration range from 8 to 300 g L????1(310????8 ????1:1210????6M). The proposed
method oered high sensitivity as well as good selectivity. A mechanistic study, showed fourelectron
reduction of nitrated 2,4-D to its hydroxylamine derivative. The proposed method was,
also, applied to the determination of 2,4-D in environmental samples such as soil samples.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Thermal Behavior of Alkaline Lead Acetate, a Study of Thermogravimetry and Dierential Scanning Calorimetry
2934
EN
S.J.
Hashemian
Institute of Water and Energy,Sharif University of Technology
Journal Article
2009
05
27
The compound, alkaline lead acetate, Pb(CH3COO)2
:PbO:H2O (ALA), was purchased from the
Fluka Company. The X-ray diraction lm and SEM electron microgaph of this compound
were obtained and reported in this paper for the rst time. The thermal behavior of alkaline
lead acetate (ALA) was studied using thermogravimetery (TGA) and Dierential Scanning
Calorimetery (DSC) techniques under an O2 gas atmosphere from 25 to 600C. Four distinct
energy changes associated with weight changes were observed, all of them being exothermic in
the DSC results. The amount of H for each peak is reported.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
KBr Catalyzed Oxidation of Alcohols and Trimethylsilyl and Tetrahydropyranyl Ethers with Fe(NO3)3.9H2O
2935
EN
F.
Shirini
Department of Chemistry,Guilan University
M.
Abedini
Department of Chemistry,Guilan University
M.A.
Zolfigol
Department of Chemistry,University of Bu-Ali-Sina
Journal Article
2009
05
27
Alcohols and trimethylsilyl and tetrahydropyranyl ethers are eciently oxidized to their
corresponding carbonyl compounds, using Fe(NO3)3.9H2O, in the presence of KBr, under mild
and completely heterogeneous reaction conditions, with good to high yields.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Determination of Mercury and Methylmercury in Aqueous Samples by Cold Vapor Atomic Absorption Spectrometry after Pre-Concentration with Bis (2-Mercaptobenzothlazole) Immobilized on Microcrystalline Naphthalene
2936
EN
S.M.
Talebi
Department of Chemistry,Isfahan University of Technology
M.
Moayed
Department of Chemistry,Isfahan University of Technology
Journal Article
2009
05
27
A method based on cold vapor atomic absorption spectrometry was used for the determination
of trace mercury (Hg+2) and methylmercury (MeHg+) in aqueous samples. The mercury in the
sample was concentrated in a column packed with bis (2-mercaptobenzothiazole), immobilized
on microcrystalline naphthalene. The method was optimized for dierent parameters aecting
the pre-concentration process, in order to obtain better sensitivity. The recovery test showed
that the method is quite reliable for use in the determination of trace amounts of mercury in
aqueous samples. The method was applied to the speciation of mercury in river water and in
the euents of wastewater treatment plants.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Application of Response Surface Methodology in Study of the Product Yield Distribution of Thermal Cracking of Atmospheric Gasoil
2937
EN
J.
Towfighi
Department of Chemical Engineering,Tarbiat Modares University
Journal Article
2009
05
27
In order to determine the yield distribution of thermal cracking of gasoil, a pilot plant was
designed and setup. A systematic experimental design was utilized based on CCD (central
composite design). The feed
ow rate, steam ratio and temperature were considered as factors
to design the experiments. Some statistical models were tuned based on the results of conducted
experiments. The models were evaluated with lack-of-t and R-squared tests. The results of
the analysis proved that the models tted well with the experimental results of the considered
products. Based on the experiments and statistical models the pilot plant was optimized in order
to maximize the net prot. At the optimum point coil outlet temperature, the feed
ow rate
and steam ratio were, respectively, equal to 843.8C, 6.02 g/min and 0.46. Regarding these
conditions, the yield of ethylene, propylene and butadiene and rate of coke formation would be
23.82 wt%, 12.13 wt%, 2.42 wt% and 14:44 10????7 g/cm2.sec, respectively.
Sharif University of Technology
Scientia Iranica
1026-3098
15
4
2008
07
01
Feed Stu Production from Methanol by Methylotrophic Microorganisms
2938
EN
P.
Jafari
Biotechnology Division,Jahad-e Agriculture Engineering Research Center
G.M.
Zamani
Biotechnology Division,Jahad-e Agriculture Engineering Research Center
Journal Article
2009
05
27
Methanol has been of great interest as a substrate for production as a novel feed grade protein
in Iran. Up to 160 methylotrophic strains were isolated at the Jahad-e Agriculture Research
Engineering Center for Scientic Research and various batch experiments were carried out at
dierent pH, temperature, agitation, aeration rate and methanol concentrations. By these
experiments, optimum production conditions were determined for one of the strains using the
Taguchi method. The results showed optimum pH around 8 at temperatures of 26 to 30C,
aeration equal to 3 vvm and agitation about 800 rpm. The methanol was found to be optimum
at concentration equal to 18 g.l????1 . In this condition, the biomass yield coecient was 0.52
g/g methanol, biomass dry weight was 20-25 g/l and the crude protein content was about 70-
78%. A deep jet fermentor of 1 m3 capacity, with a working volume of 600 liters, was used for
SCP production using isolated strains. In this continuous system, dilution rates ranging from
0.15 to 0.2 lit.h????1 were used to establish optimal condition for biomass production. Under
this condition, 30 kg cell dry weight per day was obtained. These experiments showed that
the selected methylotrophic strain has good potential for SCP production from methanol as a
substrate.