2024-03-28T19:48:35Z
https://ijcce.ac.ir/?_action=export&rf=summon&issue=1449
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Kinetic Study of Graft Polymerization of Acrylic Acid and Ethyl Methacrylate onto Starch by Ceric Ammonium Nitrate
Mohammad Taghi
Taghizadeh
Abbas
Mehrdad
Graft polymerization of acrylic acid (AA) and ethyl methacrylate (EMA) onto starch (St) were carried out in aqueous solution using ceric ammonium nitrate (CAN) as redox system under N2 atmosphere. The effect of pH, reaction time, temperature, concentrations of CAN, St, and monomers on the graft yield was investigated. Monomer reactivity was in the following order: AA>EMA.The kinetics of the graft polymerization of AA and EMA onto starch in same system with CAN was studied by acid-base and boromometric titration, respectively. The rate expressions for graft polymerization are Rg=k[AA]0.92[CAN]0.56[St]0.46 and R/g=k/[EMA]0.92[CAN]0.53[St]0.48 and a suitable mechanism is suggested. The graft copolymers were investigated by FT-IR spectroscopy. The overall activation energy of graft polymerization of AA onto starch was found to be 36.25 kJ.mol-1 within the temperature range 20-40°C, and for graft polymerization of EMA onto starch is found to be 11.88 kJmol-1 within the temperature range 25-45°C.
Kinetics
Starch
Acrylic acid
Ethyl methacrylate
Ceric ammonium nitrate
Graft polymerization
2006
03
01
1
12
https://ijcce.ac.ir/article_7792_8fa806ab903e193816c51e40de2b88f3.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
A Study on Retention of a Series of Aromatic Compounds in Mixed Micellar Liquid Chromatography Using Linear Solvation Energy Relationship (LSER)
Mohammad Reza
Hadjmohammadi
Mitra
Rezaie
The effect of SDS (0.03-0.07 M) and Brij-35(0-0.003 M) concentrations and temperature on retention parameters of 30 solutes in micellar reversed- phase liquid chromatography systems were studied using solvation parameter model. The system constants were determined by multiple linear regression analysis from experimental values of the retention factors with known descriptors by computer using the program SPSS/PC. The experimental results showed that the variation in concentration of surfactants (SDS, Brij-35) changes the cavity formation (m) and hydrogen-bond acidity (b). The value of m decreases while the value of b increases as the SDS concentration increases. The value of m and b slightly decrease as the Brij-35 concentration increases. Variation of temperature (25-38˚C) showed changes in cavity formation (m) and hydrogen-bond acidity (b). A comparison of the predicted and experimental retention factors indicated a satisfactory agreement between the two. Normalized residual plot showed that the contribution of the systematic modeling errors is approximately minor using the linear solvation energy relationship (LSER) equation. The value of cross-validated r2 was 0.973.
Mixed Micellar Liquid Chromatography (MMLC)
Linear Solvation Energy Relationship (LSER)
LSER equation in MMLC
Solvation parameter model
Aromatic compounds
2006
03
01
13
18
https://ijcce.ac.ir/article_8093_a263830b7df324c22ef67f831c30ed64.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Separation of Biojenic Amines Using Dansyl Cloride Derivatization and Mixed Micellar Liquid Chromatography
Mohammad Reza
Hadjmohammadi
Soghra
Jafari
Separation of some biogenic amines via RP-HPLC using mixed micellar mobile phase was investigated. The compounds were derivatized before hand by dansyl chloride as a chromophoric reagent. Appropriate conditions for separation, were determined by studying factors such as temperature, type and percentage of organic modifier, concentration of surfactants (SDS and Brij-35) and the pH of the mobile phase. The number of theoretical plates (N), asymmetry factor (B/A) and selectivity factor (α) considered as criteria for finding the appropriate conditions for separation. Appropriate condition, were: 40˚C, 40 mM SDS, 0.5 mM Brij-35 and 10% 1-propanol at pH=5.
Biogenic amines
HPLC
Micellar liquid chromatography
Mixed micelles
2006
03
01
19
23
https://ijcce.ac.ir/article_8094_8db9366f82bdde0254e41dee7e0e373b.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Optimization of the Production of Biosurfactant by Psuedomonas aeruginosa HR Isolated from an Iranian Southern Oil Well
Hamid
Rashedi
Mahnaz
Mazaheri Assadi
Esmaeil
Jamshidi
Babak
Bonakdarpour
In this study 152 bacterial strains were isolated from the contaminated oils in the southwest of Iran. Hemolysis was used as a criterion for the primary isolation of biosurfactant producing-bacteria. Fifty five strains had haemolytic activity , among them tweleve strains were good biosurfactant producers by measuring surface tension and emulsification activity.Two microorganism showed the highest biosurfactant production when grown on paraffin and glycerol as the sole carbon source. Glycolipid production by the isolated bacterium using different carbon (n-hexadecane , paraffin oil, glycerol, molasses ) and nitrogen sources (NaNO3, (NH4)2SO4 and CH4N2O) was studied. Biosurfactant production was quantified by surface tension reduction, critical micelle dilution (CMD) , emulsification capacity (EC), and thin layer chromatogeraphy. Best result were obtained when using glycerol at a C/N ratio of 55/1 and sodium nitrate as nitrogen source. Production of the rhamnolipid, expressed by rhamnose was 4.2 g/L and the yield in relation to biomass, was Yp/x = 0.65 g/g. Additionally, physical-chemical characteristics of the spent broth with and without cells showed a low critical micelle concentration of 19 mg/L and a decrease in surface tension to 20 mN/m (%).
Biosurfactants
Glycolipids
Rhamnolipids
Pseudomonas aeruginosa
Molasses
Nitrogen source
Carbon source
Surface tension
Optimization
Iranian oil
2006
03
01
25
30
https://ijcce.ac.ir/article_8095_6170837c2abc78a4d5a65511b9aea33f.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Chemoenzymatic Enantioselective Formal Synthesis of (-)-Gephyrotoxin-223
Ghodsi
Mohammadi Ziarani
R.
Chenevert
Ali Reza
Badiei
(-)-Gephyrotoxin-223 was formally synthesized from chiral synthon 1 which has been chemoenzymatically synthesized in the presence of Candida Antartica lipase.
Gephyrotoxin
Indolizidine
Chemoenzymatic
Candida Antartica Lipse
Alkaloids
Desymmetrization
2006
03
01
31
38
https://ijcce.ac.ir/article_8096_5adbafaa76202883890c7a427835119b.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Optimization of Fermentation Time for Iranian Black Tea Production
Masoud
Hafezi
Bahram
Nasernejad
Farzaneh
Vahabzadeh
The optimum fermentation times of black tea manufactured by two systems of Orthodox and CTC (cut, tear & curl) were investigated by measuring the quality parameters of black tea, like: theaflavin, thearubigin, highly polymerized substances and total liquid colour during the fermentation stage. Optimum fermentation times from the beginning of fermentation were determined to be 60 min and 150 min for the fine and coarse tea of orthodox manufacturing, respectively. The optimum fermentation time of CTC tea process was 30 min. Most theaflavin content of Orthodox and CTC processes were 0.63 and 0.82 percent of the total dried solids of infusions, respectively. Total color of CTC manufacturing was 16% higher than Orthodox process.
Iranian black tea
Orthodox
CTC
Theaflavin
Thearubigin
Optimum time
Fermentation
2006
03
01
39
44
https://ijcce.ac.ir/article_8097_eda1a2ff7b938e9234bca0cb28c4e6d9.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Determination of the Binding Constant of Terbium-Transferrin
Sohrab
Abdollahi
Wesley R.
Harris
Apotransferrin (apo Tf) in 0.1 M N-(2hydroxyethyl)piperazine-N2-ethanesulfanic acid at 25 ˚C and pH 7.4 has been titrated with acidic solution of Tb3+. The binding of Tb3+ at the two specific metal-binding sites of transferrin was followed from the changes in the difference UV spectra at 245 nm. The molar absorptivity per binding site for Tb3+-Tf is 22,500 ± 1000 M-1cm-1. To determine the Tb-Tf binding constants, apo Tf was titrated with Tb3+ solutions which also contained nitrilotriacetic acid as a competitive chelating agent. The sequential macroscopic equilibrium constants for the binding of two metal ions are log K1 = 9.96 ± 0.38 and log K2 = 6.37± 0.38. Titrations of both C-terminal and N-terminal monoferric transferrin with Tb3+ indicate that terbium binding is stronger at the C-terminal binding site. The value of K1 for Tb3+ is substantially higher than the teransferrin binding constants reported for larger lanthanides. It is possible that there are steric interferences to the binding of larger lanthanides. However, an analysis of the transferrin binding constants using linear free energy relationships for metal complexation suggests that the metal ionic radius alone is not the major determining factor. A change in the number of coordinated water molecules in the aqueous ions for Tb3+ compared to the larger lanthanides may be a more important factor.
Transferrin
Binding constant
Terbium
Nitrilotriacetic acid(NTA)s
UV-Difference
2006
03
01
45
52
https://ijcce.ac.ir/article_8098_8f088081b55c45832ea029cc7ebf80c0.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Volumetric and Viscometric Studies of Nucleosides, Nucleotides and Furanose Sugar in Aqueous Medium from 288.15 to 298.15K
Man
Singh
Yogesh Kumar
Sharma
Density (r/g cm-3) and viscosity (h/10-2gcm-1s-1=1centipoise,CP) of guanosine monophosphate (GMP) and adenosine triphosphate (ATP) referred to as nucleotide, and 2-deoxy adenosine (DOA) and thymidine (TMD) as nucleoside along with their integral furanose sugar, 2-deoxy ribose (DOR) from 0.0004 to 0.0014mol kg-1 solution have been measured at 288.15, 293.15 and 298.15K at atmospheric pressure. The r was fitted into the Masson and h in Jones-Dole equationsfor apparentmolal volume (Vf/cm3mol-1) and viscositycoefficient((hr-1)/m=B/kg mol-1=103gmol-1) data. The Vfand h werealso regressed forV0f and h0 values known as the limiting constants and illustrate solute-solvent and solute-solutein teractions of systems. The apparent molal volume of their various integral units like adenine, guanine and thymine of nucleotides and nucleosidesareestimatedbyV0fTheV0fh0andB values have been used to elucidate the hydrophilic and hydrophobic interactions. The V0f values are negative over the whole range of the compositions which infer greater intermolecular forces and the biomolecules as water structure breakers.
Viscosity
Apparent molal volume
Nucleos(t)ides
Hydrophilic and hydrophobic
Water structure
2006
03
01
53
66
https://ijcce.ac.ir/article_8099_65101dcad5a55c10bf3ae2f92eb6d509.pdf
Iranian Journal of Chemistry and Chemical Engineering
Iran. J. Chem. Chem. Eng.
1021-9986
1021-9986
2006
25
1
Thermophilic Aerobic Digestion of Activated Sludge; Reduction of Solids and Pathogenic Microorganisms
Mohsen
Nosrati
Sayed Abbas
Shojaosadati
T.R.
Sreekrishnan
In the temperature range of 10 to 80 ºC and in a batch digester, a typical activated sludge was digested aerobically. Reaction rate constants were determined by measuring the amounts of volatiles removed from the suspended solids at different time intervals during the process. The maximum value of the reaction rate constant (0.45 d-1) occurred in the temperature range of 55-60˚C. Removal of indicator organisms (pathogens) in the sludge, during the batch digestion, was also studied. Sludge digestion at 60 ºC provided a noticeable difference in reduction of the indicator organisms as compared to digestion carried out at 55 ºC. Optimum thermophilic aerobic digestion for high rate removal of volatile suspended solids and effective inactivation of pathogens happened in temperature range of 60-65 ºC.
Activated sludge
Thermophilic aerobic digestion
Volatile suspended solids
Pathogen inactivation
2006
03
01
67
71
https://ijcce.ac.ir/article_8100_43bc11743a971d062cc2a78545b763c5.pdf