فهرست مطالب

science and Technology (A: siences) - Volume:39 Issue:4, 2015
  • Volume:39 Issue:4, 2015
  • تاریخ انتشار: 1394/09/30
  • تعداد عناوین: 14
  • N. Samani Pages 463-472
    A neural network is developed for the determination of leaky confined aquifer parameters. Leakage into the aquifer takes place from the storage in the confining aquitard. The network is trained for the well function of leaky confined aquifers by the back propagation technique and adopting the Levenberg–Marquardt optimization algorithm. By applying the principal component analysis (PCA) on the adopted training input data and through a trial and error procedure the optimum structure of the network is fixed with the topology of [2×10×2]. The network generates the optimal match point coordinates for any individual real pumping test data set which are incorporated with Hantush’s analytical solution and the aquifer parameter values are determined. The performance of the network is evaluated by real field data and its accuracy is compared with that of the type curve matching technique. The network eliminates graphical error inherent in the type curve matching technique and is recommended as a simple and reliable alternative to the type-curve matching technique.
    Keywords: Aquifer parameters, aquitard, well function, artificial neural network, pumping test
  • S. Albayrak Pages 473-483
    The antioxidant activities of methanol (ME), ethanol (EE), water (WE) and ethyl acetate (EAE) extracts of four Inula helenium L. taxa (I. helenium ssp. orygalis (Boiss.) Grierson, I. helenium ssp. pseudohelenium Grierson, I. helenium ssp. turcarasemosa Grierson and I. helenium ssp. vanensis Grierson) were investigated. The phosphomolybdenum assay, β-carotene–linoleate bleaching and DPPH radical scavenging activity were used to evaluate the antioxidant capacity. The total phenolic contents determined by Folin-Ciocalteu assay of the extracts ranged from 4.18 to 102.91 mg gallic acid equivalents (GAE)/g dry extract. The extracts showed considerable effect on reducing the oxidation of β-carotene. The highest radical scavenging activity was obtained for ME of I. helenium ssp. orygalis in DPPH assay. ME, EE and EAE of four Inula helenium taxa showed significant antibacterial activity against 13 bacteria tested. WEs had no inhibitory effect against bacteria tested except for I. helenium ssp. orygalis. EE of I. helenium ssp. orygalis was only effective against C. albicans.
    Keywords: Inula helenium, antimicrobial activity, antioxidant activity, DPPH
  • A. Ahmadi Peyghan Pages 485-489
    Adsorption of NH3 and H2O molecules on pristine and B–doped Al12N12 nano–cage was investigated using density functional theory, by means of B3LYP and X3LYP functionals. Both NH3 and H2O molecules were found to bind to an Al atom of Al12N12 via chemisorption, releasing energies ranging from –1.48 to –1.53 and –1.16 to –1.22 eV, respectively. The binding energies of X3LYP functional are somewhat larger than those of the B3LYP. The Morokuma–Kitaura energy decomposition approach reveals that the nature of these interactions is mainly electrostatic rather than covalent. The Al12N12 strongly adsorbs these molecules without any change in its electronic properties namely, these processes are electronically ineffectual. B–doping decreases the adsorption energies of the studied molecules whereas it cannot affect the sensitivity of the Al12N12 towards them.
    Keywords: Aluminum nitride nanocluster, adsorption, theoretical study, DFT
  • S. A. Amin Pages 491-495
    Indoor radon concentrations, the annual effective dose rate and the annual equivalent dose rate to the lung and to the public were measured in the dwellings of 10 neighborhoods located on the west side of the river Tigris (Al-Karkh) in Baghdad city using passive dosimeters. CR-39 solid state nuclear track detector (SSNTD) technique was used for radon measurements. Ninety-one dosimeters were distributed in the dwellings of the study area, three dosimeters were planted in three rooms of each house depending on the usage of the room (bedroom, living or sitting room and kitchen). They were left for a period of 3 months during winter time from November 2013 to February 2014. Radon concentrations were found to range from 64.9 Bq.m-3 to 94.7 Bq.m-3 in Daoudi and Hayy Al-Jamiaa, respectively, with a mean value of 79.82±1.05 Bq.m-3. The mean annual effective dose rate and the mean equivalent dose rate were found 2.00±0.04 mSv.y-1and 4.81±0.06 mSv.y-1. The dwellers of Hayy Al-Jamiaa were found to be exposed annually to the highest equivalent dose rate of 5.74 mSv.y-1. All measured values were lower than the international recommended value given by ICRP.
    Keywords: Indoor radon, CR, 39, annual effective dose, annual equivalent dose, Baghdad
  • F. Ghanati Pages 497-501
    Marshmallow is a medicinal plant containing mucilage polysaccharides and various phenolic acids. Boron (B) is an essential micronutrient whose necessity for plant growth and development has been attributed to its role in cell wall pectin network and maintenance of integrity and performance of membranes. The present study was aimed to investigate the effects of different concentrations of B (0.01, 0.1, and 1 mM respectively as deficient, sufficient or control, and excess concentrations) on cell wall polysaccharides of suspension-cultured Althaea officinalis cells in a modified LS medium. The results showed that under B deficiency higher ratio of cell production was devoted to produce wall materials (4.4% of fresh weight), compared with normal and excess B supply (2.3% and 1.8% of fresh weights, respectively). Moreover, B deficiency drastically reduced relative contents of hemicellulose A and cellulose (78% and 72%) compared to those of the control cells. No significant change appeared in the relative amount of pectin in cell walls of deficient and excess B treated cells, in comparison with normal concentration of B. Boron deficiency significantly increased hemicellulose B (157% of the control). This may help the cells with increasing sites for B adsorption under insufficient B supply, while improving its health benefit, since hemicellulose contributes to lowering cholesterol and increasing gut bacteria.
    Keywords: Boron, marshmallow, medicinal plant, mucilage polysaccharides, tissue culture
  • J. K. Bhatia Pages 503-513
    Modification of natural polymers like protein by graft co-polymerization is an important method to incorporate the desired properties into the backbone. Soy protein concentrate (SPC) was grafted with ethylmethacrylate (EMA) using ascorbic acid /potassium persulphate as redox initiator system under pressure. Different reaction parameters such as reaction time, reaction pressure, solvent amount, initiator ratio, pH and monomer concentration were optimized to get maximum graft yield (59.5%). The optimized reaction conditions were: reaction time; 150 min, reaction pressure; 7.5 psi, solvent; 150ml, AAc: KPS; 1:1.25, pH; 8, [EMA]; 1.99 X 10-3 Mol L-1. The graft copolymer formed was characterized by FTIR, XRD and SEM techniques. The grafted protein was found to undergo physico-chemical changes on incorporation of polymer chains onto backbone through graft copolymerization which resulted in enhanced resistance towards moisture absorbance and acid-base attack. Thermal analysis showed higher final decomposition temperature of grafted protein as compared to that of ungrafted backbone.
    Keywords: Biopolymers, graft copolymer, soy protein concentrate, thermal analysis, moisture resistance, swelling studies, redox initiator, pressure induced
  • E. Bagherzadeh, Khajeh Marjan Pages 515-519
    In this paper, absorption spectra of both solution and films of cyano azobenzene polymer are investigated. The analysis of overlapped absorption spectra of polymer, related to trans and cis isomers, shows that the population of cis isomers is higher than trans isomers. It means that, cyano azobenzene molecules have a folded structure in polymer, in thermal equilibrium. Presence of cyano molecules causes this folded structure. Illumination of polymer films, prepared by THF solvent, with light of diode pumped solid state laser, results in increasing the population of isomers and their absorption peaks, due to trans-cis and cis-trans photoisomerization process. Then, Isopropanol is added to solution to enhance the freedom degree of molecules. So, the population of trans isomers in films and solutions, prepared by THF+Isopropanol are higher than trans isomers in films prepared only by THF. The illumination of polymer films prepared by THF+Isopropanol changes the concentrations of isomers due to photoisomerization process.
    Keywords: Photoisomerization process, cyano azobenzene, trans isomer, cis isomer
  • S. Huang Pages 521-525
    A polynomial 1 2 (,, ,) n f X X X is called multilinear if it is homogeneous and linear in every one of its variables. In the present paper our objective is to prove the following
    Let R be a prime K-algebra over a commutative ring K with unity and let 1 2 (,, ,) n f X X X be a multilinear polynomial over K. Suppose that d is a nonzero derivation on R such that 1 2 1 2 (,, ,) (,, ,) s t df x x x n  f x x xn for all 1 2 ,, , n x x x R, where s,t are fixed positive integers. Then 1 2 (,, ,) n f X X X is central-valued on R . We also examine the case R which is a semiprime K-algebra.
    Keywords: Prime, semiprime rings, ideal, derivation, GPIs
  • M. Karimkoshteh Pages 527-532
    The selective reduction of oximes with sodium borohydride (NaBH4) in the presence of nano Cu and charcoal was investigated. Cu nanoparticles are widely used as catalysts; efficacious catalyst: copper and copper alloy nanometer feature high efficacy and selectivity, and can be used as catalyst in some reactions. We have shown that NaBH4 in the presence of charcoal is an efficient protocol for the reduction of oximes. Reduction reactions were carried out in EtOH (5 mL) as solvent under reflux condition at 70–80oC. The product amines were obtained in high to excellent yields. The stereo-chemistry of the reduction by using nano Cu is distinctively different from the other methods.
    Keywords: Reduction, Oxime, NaBH4, Nano, particle Cu, Charcoal
  • H. Kocayigit Pages 533-541
    In this paper, we give some characterizations for Legendre spherical, Legendre normal and Legendre rectifying curves in the 3-dimensional Sasakian space. Furthermore, we show that Legendre spherical curves are also Legendre normal curves. In particular, we prove that the inverse of curvature of a Legendre rectifying curve is a non-constant linear function of the arclength parameter.
    Keywords: Legendre curve, normal curve, rectifying curve, Sasakian space
  • S. Dadras Pages 543-549
    In this work we simulated the representative volume element (RVE) of carbon nanotube (CNT) which is surrounded by high temperature superconductor (YBCO) by using ANSYS finite element software. First we considered perfect model (for YBCO and CNT) and investigated the effect of radius, length, and the number of nanotube in Young’s modulus of the YBCO by applying force on RVE. Then, a third region an interphase between CNT and YBCO were considered, the Young’s modulus of which is between CNT and YBCO. It is demonstrated that there is a critical radius around 6 nm for the CNT and by applying the CNT with a radius smaller than 6 nm, the Young's modulus of the YBCO increases. Also, by increasing the number of the CNTs with radius smaller than 6nm, the Young's modulus and strength of the matrix (YBCO) increases. According to the non-linear analysis, the Young’s modulus of the CNT doped YBCO matrix is increased 20-22% more than the undoped YBCO sample.
    Keywords: CNT, Young's modulus, YBCO, RVE
  • M. A. Javed Pages 551-558
    In this paper, the flow of couple stress fluid is investigated in a helical screw rheometer (HSR). By unwrapping the channel, lands, and the outside rotating barrel, the geometry of HSR is approximated as a shallow infinite channel. Both one- and two-dimensional analysis of the problem is presented using rectangular coordinates. In either case an exact solution of the flow problem is presented and the formulas of velocity profile and volumetric flow rate are obtained as a function of couple stress parameter. It is observed that velocity profile decreases in going from Newtonian to couple stress fluid which indicates a decrease in extrusion process for a couple stress fluid in comparison with Newtonian fluid. Moreover, the volumetric flow rate is found to be a decreasing function of couple stress parameter.
    Keywords: Couple stress fluid, helical screw rheometer (hsr), volumetric flow rate, exact solution
  • Qing, Tian Deng Pages 559-565
    Functionally graded Poisson’s ratio structures have been developed for critical protection. In this paper, the static bending and buckling of FGPR nanoscale beam are studied based on the nonlocal Timoshenko beam model, in which both Young’s modulus and Poisson’s ratio are assumed to vary continuously in the thickness direction. By utilizing total potential energy principle, equilibrium equations are derived. In the numerical results, beam models with different material properties are introduced, and the effects of the nonlocal parameter, aspect ratio and the Poisson’s ratio on the deflection and buckling are discussed.
    Keywords: Functionally graded, Poisson's ratio, nanoscale beam, nonlocal theory
  • Mahmood, Ur, Rahman Ansari Pages 567-572
    Seed–storage proteins are important reservoirs of food and energy which are also involved in the determination of bread making quality. Solubility properties of these proteins are traditionally classified into four classes: albumin, globulin, prolamin and glutelin. Gliadin and glutenin have also been studied extensively and the genetics and biochemistry are relatively well known. Grain proteins from 18 Pakistani wheat genotypes were checked for genetic diversity evaluation based on 15% sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS–PAGE). According to quality score, WL–711, Abadghar, Yacoora, Punjab–96 and Zardana showed the highest score of 10. All these varieties had subunit 5+10 which had positive correlation for bread-making quality. Different Bioinformatics tools like STRUCTURE, TASSEL AND STATISTIXL were used to examine the data obtained from different varieties and the outcomes were conveyed in the course of a dendrogram revealing the conflicts and similarities among varieties. STRUCTURE was used for the analysis of population structure. This tool performed the grouping of 18 wheat varieties into two groups. TASSEL was used for cluster analysis, which grouped the varieties under study into two main groups containing the same individuals as described by other tools. STATISTIXL performed a cluster analysis using the similarity measure of Jaccard. The results were shown in the form of dendrogram on the basis of group average. Dendrogram revealed two main clusters differentiated as A and B at the distance of about 85%. With the aim of improving flour quality, wheat seed storage protein fingerprinting is used to govern the gluten protein pattern in studies.
    Keywords: Storage Proteins, wheat, glutelin, SDS–PAGE, dendrogram, Bioinformatics