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مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    1
  • End Page: 

    4
Measures: 
  • Citations: 

    0
  • Views: 

    25044
  • Downloads: 

    10082
Abstract: 

The stereoselective synthesis of (S)-methyl-2-[4-(2-hydroxy-2-(isopropyl amino)-ethoxy]-phenylacetate has been carried out in six steps with an overall yield of 65.6%. The key intermediate is chiral epoxide (7), which was achieved by applying Sharpless asymmetric dihydroxylation method with high enantiomeric purity and in excellent yields.

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Writer: 

AFOLABI A.S. | BORODE J.O.

Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    11
  • End Page: 

    16
Measures: 
  • Citations: 

    0
  • Views: 

    18868
  • Downloads: 

    10574
Keywords: 
Abstract: 

The corrosion inhibition of mild steel in 3.0 M sodium chloride and 0.5 M sodium sulphide using various concentrations of ammonium molybdate was investigated in this work. The inhibition effect of this reagent in these media was monitored by weight loss and pH measurements. The analyses of the weight loss results showed that the corrosion susceptibility of mild steel in 3.0 M sodium chloride was more pronounced than in 0.5 M of sodium sulphide due to the aggressive chloride ions in the former and the weak nature of the latter. Ammonium molybdate produced a better inhibition performance of mild steel in 0.5 M sodium suphide than in 3.0 M sodium chloride medium and the higher the concentration of ammonium molybdate the more the inhibition performance on mild steel in the media studied. Optimum inhibition was obtained at 2.5 M ammonium molybdate in both media. The pH values in chloride medium remained acidic throughout the exposure period while those of sulphide medium shifted to alkaline region with exposure time; an effect that was traceable to higher inhibition obtained in the latter medium.

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Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    17
  • End Page: 

    28
Measures: 
  • Citations: 

    0
  • Views: 

    20143
  • Downloads: 

    13925
Keywords: 
Abstract: 

Di-2-pyridyl ketone nicotinoylhydrazone was prepared by condensation between appropriate aldehyde/ketone with the respective acid hydrazide. The FT-IR spectrum is recorded and analysed. The vibrational frequencies were computed using the HF/6-31G(d) and B3LYP/6-31G(d) basis and compared with experimental data. The infrared intensities and first hyperpolarizability are reported. The calculated data suggest an extended π-electron delocalization over the pyridyl and nicotinoyl hydrazone moieties which are responsible for the nonlinearity of the molecule. Optimized geometrical parameters (DFT) of the title compound are in agreement with similar reported structures.

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Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    29
  • End Page: 

    38
Measures: 
  • Citations: 

    0
  • Views: 

    33193
  • Downloads: 

    16423
Keywords: 
Abstract: 

This is a case study of AL-Za’afaraniya tanning factory, 15 km to the south of Baghdad, to spot light on simple chemical treatment of the discharged water to solve the environmental problems associated with its chromium content management. The treatment was extended to the recovery and reuse of chromium. Chromium was precipitated by the addition of magnesium oxide which also aid as a neutralizer for the acidic effluent. The laboratory treatment was carried out to find the optimum conditions. The wastewater samples were taken from the outline area of the tannery. Box-Wilson method was adopted to find useful relationships between the operating variables (temperature, mixing period and magnesium oxide dose) and the pH and chromium content of effluent. The experimental data were successfully fitted to second order polynomial mathematical models for the treatment. The most favorable operating conditions for the treatment were: temperature, 30°C; mixing period, 50 min and magnesium oxide concentration, 3000 mg/L. On using the optimum conditions a mathematical model simulating the operation for the treatment was obtained as follows:Cr = 6.0848 – 0.001839 X11 – 0.105334 X12 – 0.041038 X13pH = 10.29086 – 0.001223 X11 – 0.140043 X12 – 0.00953 X13Experimentally Cr concentration was decreased to about (0.5 mg/L) in wastewater after raising the pH value to (7.35) by adding magnesium oxide.

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Writer: 

RAOUF M. | MAHDAVIAN L.

Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    39
  • End Page: 

    45
Measures: 
  • Citations: 

    0
  • Views: 

    19067
  • Downloads: 

    11298
Keywords: 
Abstract: 

In this research, the effects of Ca2+ on TnC (Troponin C) are investigated. TnC controls the calcium in muscle contraction and is the Ca2+-binding subunit of the troponin complex. The nanosecond mobility domain presents in solution, as determined by QM/MM of Charmm (Chemistry at Harvard Molecular Mechanics) program, is fully calculated in fibers. The orientation analysis revealed a bimodal orientation distribution of TnC in the presence and absence Ca2+. Thermodynamic properties are calculated for this orientation (TnC and Ca2+) and the Ca2+ interaction with NH2 and COOH terminals of troponin C, the impact of lactic acid concentration on Ca2+ from its sites on troponin C are studied, and the effect of temperature increase on the interaction.

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Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    46
  • End Page: 

    51
Measures: 
  • Citations: 

    0
  • Views: 

    18080
  • Downloads: 

    8928
Keywords: 
Abstract: 

An efficient protocol has been reported by insitu generation of HCl from cyanuric chloride and used for the synthesis of 4-aryl-3,4-dihydropyrimidines.

Yearly Impact:  

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Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    5
  • End Page: 

    10
Measures: 
  • Citations: 

    0
  • Views: 

    26840
  • Downloads: 

    18951
Keywords: 
Abstract: 

Two pectinase producing fungi species were isolated. Using a defined mineral medium and pectin as the carbon source, the capability of the species to produce pecinase was investigated in surface culture fermentation. The results showed that Aspergillus niger performs better than Thericoderma reesei in term of pectinase production, glucose has a repressive effect on pectinase production, and among nitrogen sources of ammonium sulfate, yeast extract, and sodium nitrate, ammonium sulfate is the best. The maximum exo-pectinase obtained in this research was about 1.7U/mL and the maximum endo-pectinase activity was about 0.015U/mL. Pectinase production was very weak when pectin was substituted by sugar beet pulp probably due to inefficient contact between the microorganism and substrate particles in surface culture fermentation. Using sugar beet pulp in solid-state fermentation gave results comparable with those obtained in surface culture fermentation of pectin and in this research was investigated the feasibility of continuous surface culture fermentation for pectinases production. The bioreactor was placed in an incubator at 35°C.

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Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Start Page: 

    52
  • End Page: 

    60
Measures: 
  • Citations: 

    0
  • Views: 

    14837
  • Downloads: 

    8952
Keywords: 
Abstract: 

This is a comparative study of the corrosion behaviour of welds in AISI 304 and AISI 904L stainless steels carried out in seawater model solution in the temperature range 5-35°C and the standard of corrosion testing of welds was followed. The corrosion rate and corrosion attack characteristics were determined for welds of the examined steels with several type of treatment. The aim of this work was to compare the steels based on their resistance against the corrosion in terms of pitting potential (Epit) and repassivation potential (Erepass). Seawater is an electrochemically aggressive medium, which can initiate localised corrosion in welded stainless steels. Different electrochemical and testing methods were used, including cyclic voltammetry, chronopotentiometry, electrochemical impedance spectroscopy (EIS), pH measuring and penetration tests.

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مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID
مرکز اطلاعات علمی SID