Vol. 17 No. 4 (2005)
Articles
Abstract: A spectrophotometric method is proposed for the determination of microgram amounts of paracetamol based on the reaction of hydrolytic product of paracetamol (p-aminophenol) with chlorochresol in the presence of dissolved atmospheric oxygen and sodium carbonate, The absorbance of the blue indophenol dye is measured at 630 nm and the molar absorptivity found to be 8,63xl03 l.mol"1 .cm"' and conforms to Beer's law obeyed over the range 0.1-8.0 Hg ml' .The method is successfully employed for assay of paracetamol in various pharmaceutical formulations and results have been compared well with those obtained by the official methods indicating that the proposed method can be applied successfully in the assay of pharmaceutical preparations for paracetamol.
Abstract: A simple and sensitive spectrophotornetric method for the determination ofphenol has been developed. The method is based on the oxidative-coupling reaction ofphenol with 4-amino-N,N-diethylaniline in the presence of potassium dichromate at pH 6 solution to form an intense bluish-green water-soluble dye that is stable and has a maximum absorption at 670nm. A plot of absorbance versus concentration shows that Beer's law is obeyed over the concentration range of 2.5-250 jag of phenol in a final volume of 25ml,(i-e 0.1-lOppm) with a molar absorptivity of 3.95 x 104 l.mor'cm"', a percentage recoveries of 98.10-100.75% and a relative standard deviation of better than ±0.4%, depending on the concentration level. The optimum conditions for full colour development are described and the proposed method is extended to some other phenolic compounds.
Abstract: The reactions of thiosulphate ion with some bromoalkylamines of structure RR'N-(CH2)n-Br, where n = 2,3,4,5 or 6 and R - R1 - H, methyl, ethyl or isopropyl, were studied kinetically in an aqueous solution at different pH, The kinetic results for these reactions in basic medium gave explicit evidence in favour of the formation of cyclic intermediate during the reaction course. The rate of these reactions depends mainly on the reactivity of the cyclic intermediate. It has been found that thereactivity of large ring intermediate is mainly controlled by the energy of ring strain relief. As the ring size becomes small (smaller than five members) the rate of the reaction becomes very fast and can't be explained on the bases of ring strain relief only, In order to explain this observation other factors may affect the reactivity of the cyclic intermediate are taken into account, such as the electron density at the nitrogen atom, the sterochemical situation at the reaction centre and the probability of a successful reaction. Taking into account these factors gave a better explanation for the high reactivity of small ring are given, On the other hand, it has been observed that the reaction in acidic medium proceed with a different mechanism in which the reaction occurs by a direct attackment of the nucleophile on the methylene group attached to the bromo group. The dependence of the rate constants on temperature were studied in order to estimate the thermodynamic parameters which were utilized in the discussion of the factors affecting the rate of ring opening reaction.
Abstract: The kinetics of the oxidation of nine amino acids (glycine, alanine, valine. leucine, norleucine, serine, threonine, spartic and lysine) by permanganate ion were studied in an aqueous medium. The results showed that the oxidation reaction proceeds through two different pathways, The first is noncatalyzed and the second is autocatalyzed by the colloidal inorganic product (MnO2). The rate of the noncatalyzed reaction is first-order in concentration of both amino acid and oxidizing agent, while the autocatalyzed reaction is first-order in concentration of amino acid, oxidizing and autocatalytic agent. Depending on the relation between the rate constant and temperature the thermodynamic parameters for the two pathways were calculated. A special care has been given to the effect of the structure of the group attached to chiral carbon atom of the amino acids on the rate and mechanism of oxidation reactions. Thekinetic results gave evidences supporting the proposed mechanism for the reaction, On the other hand, by measuring the rate of oxidation at different pH medium, the rate constant of oxidation of ananionic and zwitterionic form are calculated.
Abstract: Natural Iraqi mineral clays, treated chemically by acids and bases and activated physically, have been investigated using powder x-ray diffraction , x-ray "thermal analysts; mTrarecT Ifpecfra, instrumental analysis. Results indicate that those samples contain a considerable amount of feldspar mineral and have physical and structural properties evaluated their scientific and economic utilization to be applied in fractionation processes as adsorbent to separate Iraqi heavy crude oils into their simple components. Infrared spectra has been applied to study the chemical composition of the separated fractions.
Abstract: New complexes of the general formulae [Ni(L)2X2],[M(L)2]X2 and [M(L)2SO4.1 120] where M=Ni(II),Co(l[),Cu(n);L=a-(2,6-dimethyl anilino)-2,6-dimethyl acetanalide ; X=Cl",Br",N03", have been prepared and characterized by elemental analysis, conductivity measurements .magnetic moments and spectral (IR and electronic) studies. Chelated structures have been proposed for the resulting complexes in which the ligand acted as bidentate chelating ligand through the two nitrogen atoms.
Abstract: The new charge-transfer complexes (CT) of eleven Schiff1 bases molecules as n-electron donors with the acceptor 1,4-naphthoquinone were studied spectrophotometrically in chloroform solution. The physical constants (a,b,CI,C2,Ea) of 1,4-naphthoquinone were calculated and they are 0.8385, -4.157, 7.067, 1.92, '1,39 electron volt respectively. where a= slop of straight line of first order equation , hv= alp + b, b=y = interept of first order equation ,( b = hv - alp), Cl and C2 are physical constants of acceptor (eq.3.) ,Ea ~ electron affinity of 1,4 -naphthoquinone , which is calculated from equation ( 1). The physical parameters of the (CT) complexes, of Benesi- Hildebrands equation; ( l/( e K))= slop of equations, b=l/e -intercept y of the straight line of benesi-Hildebrands equation ( of first order), where the molar extinction coefficient= e and K= the equilibrium constant of the formation of bond n-pi (CT) complexes ,' the average dissociation energies of the excited state W=4.70 eV were also calculated and discussed. Key words: Charge-transfer complexes (CT), l,4-Naphthoquinone,Physical chemistry of donor, Acceptor, Aliphatic aldehyde, Valence bond theory, Schrodinger equation and quantizatin , Donor of aliphatic Schiff bases(azomethines). p-N.N-dimethylaminocinnamaylidenes, Aromatic primary a mine , Electromagnetic light photon, 1,4-Quinones and carbonyl conjugation chemistry, Physical calculation, Benesi-Hildebrand's equation , Aliphatic subslituents and their effects, Education and science studies. HOMO' *LUMO transition.
Abstract: Wheat flour (WF) of 85% meal extraction was blended with/without 50g defatted soybean flour (DSF)/kg and enriched with 50 or lOOmg iron/kg diet used in vitro and In vivo study of protein digestibility, Sixty male weanling albino rats were used as a biological model for this study. Rats were divided into two major equal groups, First group as healthy control rats and second group as iron depleted rats. Each group was subdivided into six groups according to their body mass (BM), These subgroups fed experimental diets for 10 days. Digestible protein (%) and its digestibility index, rat BM gain and its growth index were estimated using in vivo and in vitro methods, Dietary iron absorption, apparent digestibility, and rat nutritional status of iron depleted and healthy rats were determined. In addition the metabolic energy of the six diets and rat growth index were calculated. Data analysis showed that, the in vivo protein digestibility index was lower than thai index of in vitro. Protein digestibility index of the anemic rats was higher than that index of healthy rats. The growth index of the healthy rats was higher than that index of the anemic rats. The rat growth index positively proportional to the dietary iron level, The DSF presence in diet caused growth index improvement. The WF+50g DSF+50mg iron diet improves protein digestibility and rat growth index.
Abstract: Noise spectra of semiconductor laser subject to a phase-conjugate feedback were investigated theoretically. Time-delayed rate equations with feedback were solved and characteristic equations for relative intensity noise and frequency noise spectra were derived. Numerical results indicate that the relaxation resonance peak was moved to a new frequency region determined by the amount of feedback, This is a technological importance for the improvement of modulation bandwidth, Noise level was affected by the feedback parameters, mainly; the response time and the feedback rate.
Abstract: In abnormal glow discharge under d.c, excitation at different pressure in a varying axial magnetic field in the range (0 to 6.5G) some measurements of plasma parameters, glow discharge resistance Rg electrical conductivity ag and electron temperature Te have been carried out for various discharge currents using double probe method, The results show that the average discharge current increase and the corresponding voltage across the discharge gap decreased consequently glow discharge resistance and electron temperature decreased with the increasing magnetic field while the electrical conductivity increases according to that. This is due to magnetic field confinement which restricts expansion of the plasma charged practices. These measurements show a good agreement with the previous studies.
Abstract: In order to study the practicability delimitating the optimal electrical properties have been studied for soft ferrite system Mg(|. x)MnxFe20.4 , which prepared by solid state method in the temperature range 300 to 550 K by substituting Mn2+ ions instead of Mn2+ ions. The resulting of this study shows that the electrical conductivity for these systems were optimal value (10"7) The calculation of activation energy gave of 0.224 eV and 0.243 eV. The positive sign of thermoelectric power (seeback coefficient) for these samples at lower concentrations of substitution Mn2+ ions , and negative sign of at higher concentrations of substitution Mn2+ ions. Also the optimal magnetic susceptibility properties resulted in values -86x10" j -622x10". From the electrical properties (electrical conductivity and thermoelectric power) and magnetic susceptibility, the optimal results where obtained with x~ 0.1 for Mn2+ ions.
Abstract: In this paper, we find the algebra of quotients with bounded evaluation for operator algebras on a complex Hilbert space, namely: Hilbert - Schmidt and trace -class operators. Also, we study the behavior in computing the algebra of quotients with bounded evaluation for totally prime associative algebra,
Abstract: Most GPS receivers calculate their locations by a geodetic coordinate referenced to the WGS84 ellipsoid, whereas the local reference applied in IRAQ (referred as ClarkelSSO ellipsoid) have different geodetic coordinates. This paper presents the results of particulars conversion between geographical and UTM grid coordinates system from WGS84 reference ellipsoid system to ClarkelSSO reference ellipsoid system for a selective locations in Mosul (Zone 38N). Conversion formulae and parameters are also given to facilitate users to convert the coordinates of any point in the study area between the two systems by using GPS.receiver and ArcGIS software. The result shows that the geographical and UTM grid systems of the two systems are slightly different, but additive constants are sufficient to attain the general accuracy.
Abstract: Indirect spectrophotometric method has been described for determination of microgram amounts of acetaniiide in aqueous solution. The method based on the acid hydrolysis of acetaniiide and the produced aniline is reacted with DDQ reagent as 7t-acceptor at pH 9 to form charge transfer complex with maximum absorbance of 345 nm. Beer's law obeyed the concentration range of 0.1-4.0 ug / ml of acetaniiide and the molar absorptivity is 13600 1/mol.cm with good precision and accuracy, also, the optimum conditions of the reaction are studied.0
Abstract: The research workaimed to prepare an activated carbon from the external shell of the coconut . the coconut shell is rich in lignin and has a high content of carbon .The prepare method involved modification of the carbonization process by addition of different percentages of aniline. Mean while keeping the coconut amount and carbonizing agent (NaOH) in constant ratios, Carbonization was conduced at 550' C for 3 hrs. The product was purified by washing with distilled water , refluxing with 10% HCI , then carbon produced was dried for 24 hrs at 1 10-120'C Evaluation of carbon was carried out through measuring density , humidity and adsorptive properties for external and internal area by inelhylene blue and iodine adsorption respectively.
Abstract: Sunflower friable callus used in obtaining cell suspension culture in liquid MS medium containing 2,0 mg /L.NAA and 1.0 mg/ L BA, The cell started their first division after 24hours and continued their division reaching to 7,33-8.50 x 103 cell / ml after 4 days of incubation. Culturing of cell suspension using Multiple Drop Array (MDA) technique promote the divisions of cells and the formation of cell colonies which developed to form callus primordia, Electro treatment of cell suspension enhanced division of cells, and the first division, occurs during 3-5 days the. total number of cells colonies reach to 380. Callus formed cell suspension from sunflower did not overcome the regeneration problem in this plant,
Abstract: Five different fungal isolates were cultivated in a medium containing orange waste as a sole carbon source. Among fungal isolates, Aspergillus niger was superior in protein production ( 35,94 % ) based on dry weight after 8 days of incubation, Effect of different concentrations of orange waste powder also were studied. Maximum fungus growth and protein production occurred at 4 %. Out of 3 yeasts, Candida utilis gave. higher protein yields ( 33,05 % ) after 5 days of incubation. In an attempt to increase production of protein, a mixed culture of A. niger and C. utilis was done. Inoculation of C. utilis after 4 days of inoculation of A. niger resulted in increasing production of protein to 42,17 %.
Abstract: This study includes the isolations and diagnoses of Actinobacillus actinomycetemcomitans from the patients with periodontal infections , isolation process has been done through using a selective medium named (Dentaid-1), Samples was cultivated anaerobically at 37°C for 48 hours. The aqueous and ethanolic extracts of the Cy penis rotundus plant were prepared and their inhibitory effect on the growth of these bacteria was carried on using the disk diffusion method. The results showed significant inhibitory effect on the growth of these bacteria at 50 , 100 and 200 ing /ml compared with tetracycline.
Abstract: This study has dealt with the effect of four different concentrations (0.0 control, 20,40 and 60) ppm of the growth regulator (mepiquat chloride) on the growth and some physiological aspects of safflower under green-house conditions. The main results indicate that the addition of the growth regulator in different concentrations has led to decrease in the height plant, root length , and significant increase in the dry weight of shoots and roots, especially with concentration of (20) and (40) ppm. The spraying of the shoots, has led to increase the relative water content in the plant leaves and decrease the cell membrane stability in comparison with untreated plants, moreover a significant decrease noticed in the concentration of proline especially with concentrations of (20) and (40) ppm and increase in the concentration of chlorophyll b particularly with concentration (60) ppm.
Abstract: This research work was aimed to separate ethanolic extract and cinnamalciehyde from Cinnamomum zeylanicum, The isolated compounds were used to study the inhibiting effect: on the growth of bacteria. These are Pseudomonas aemginosa, Escherichia coll, Proteus mirabilis, Salmonella typhi, Bacillus subtills, Staphylococcus aureus and Streptococcus pyogenes. The isolation was performed by using column chromatography packed with activated silica gel. Furthermore, die compound was identifloated by Tt.C plale technique and infrared spectroscopy (IK). Ethanolic extract showed strong inhibiting effect on B. sub/ifis and Ps. aeroginosa as compared with control samples (Tetracycline and Chloramphenicol). It showed effect inhibitory on E. coli, Salmonella typhi and Proteus mirabilis less than control samples. Also no clear effects on Staph, aureus and Strept. Pyogenes was indicated. Cinnamaldehyde showed stronger effects (compared with ethanolic extract) on E. coll, Ps, aeroginosa, Salmonella typhi and Ptroteus mirabilis in comparison to control samples. It showed effect on Strept. pyogenes equal to that of control samples, but no effects on Staph. aureus were observed.
Abstract: This study was conducted to determine contamination of meat (cow, sheep) by salmonella in AL-anbar province to however isolation of sarnonella from meat overed in some shopes of meat and to know the Species of salmonella finally their sensitivities to some antibiotics. Atolal oflSO samples of meat (cow , sheep) were randomly collected during the period from June 2002 to February 2003. The results of study showed that the total number of isolates for meat is 11 isolated which represent 6,1 %, species of .£_ typhimurinm, S,_ anaturn, S, arizona. The results of isolates showed high percentage in July then June, August, September, then October, December, there is no isolation in November, January. The results of this study revealed that species of salmonella were resistant with a high percentage 85% to ciprofloxacin and lesser that 50% to tetracycline while susceptibility 90% to cephalexin and lesser that 50% to streptomycin.
Abstract: In this paper we investigate the existence and approximation of the periodic solution for a system of nonlinear integro -differential equations with retarded argument. The numerical -analytic method has been adapted to study the periodic solutions of the nonlinear ordinary differential equations that were introduced by Samoilenko, This work lead to develop and expand the method, which is mentioned above, and thus the results obtained are more comprehensive that the study mentioned previously in the reference [1].