373 research outputs found

    Finite Element Modelling of Strengthened Simple Beams using FRP Techniques: A parametric Study

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    The main objective of this paper is to study analytically the strengthening of a simplereinforced concrete beams due to excessive uniform loads in flexure, shear and acombination of flexure and shear, using externally bonded FRP sheets technique. Acommercial finite element computer program ANSYS has been used to perform a structurallinear and non-linear analysis for several models using several schemes of FRP sheets. Aparametric study has been performed for a lot of strengthened beams. FE models studies amain parameter of different schemes of FRP sheets in flexure, shear and combinationflexure/shear. Comparing the results with a control beam model – simple reinforcedconcrete beam without strengthening – it is obvious that all strengthened beams have agreater ultimate capacity than the control beam and noticeable enhancement in memberductility. The increasing level differs as a result of the strengthening scheme. Thestrengthened beam in both flexure and shear gives a higher ultimate load capacity, delay thefailure and prevent debonding failure up to a level at which debonding occurs in bothlongitudinal and wrapped jackets CFRP sheets

    An O((m+n) Max {m+n, nÂł}) Procedure for Solving the Linear Programming Problem

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    An iterative method based on conjugate gradient projection method (and not on any variant of Karmarkars algorithm) for solving linear programming problems is given. Our method consists of a sequence of moves: Starting with an initial interior point x our procedure finds a second feasible point 0 x then a third point and so on until the optimal point is reached in at most m+n steps . A simple example is given to illustrate our method

    DNA Fingerprinting, Chemical Composition, Antitumor and Antimicrobial Activities of the Essential Oils and Extractives of four Annona Species from Egypt

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    The leaf essential oils of four members of the Annonaceae grown in Egypt (namely; Annona cherimola, A. squamosa, A. muricata and A. glabra) have been obtained by hydrodistillation and analyzed by GC-MS in order to compare and contrast the volatile chemical compositions of these species.  The essential oils were screened for in-vitro cytotoxic activity against breast cancer (MCF-7), colon cancer (CACO) and liver cancer (HEPG2) cell lines and antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeuroginosa, Aspergillus flavus and Candida albicans. beta-elemene (25.02%), beta-caryophyllene (37.11%), bicycloelemene (23.58%) and and beta-gurjunene (42.49%), were the major constituents of Annona cherimola, A. squamosa, A. muricata and A. glabra, respectively. Ethanol extracts showed highly significant cytotoxic activities (low IC50) much more than results displayed by essential oils on breast (MCF-7), colon (CACO) and liver (HEPG2) carcinoma cell lines. Relative to breast carcinoma cell line (MCF-7), The IC50 values of ethanol extracts were 3.43, 3.89 and 4.34 ?g/ml for A. cherimola, A. squamosa and A. muricata ethanol extractives respectively. While colon carcinoma cell line (CACO) displayed IC50 values 2.82, 2.97, 3.58 and 3.89 ?g/ml for A. muricata, A. cherimola, A. glabra and A. squamosa, respectively. Liver carcinoma cell line (HEPG2) exhibited IC50 valus of 3.12, 3.43 and 3.73 for A. squamosa, A. muricata and A. cherimola, respectively. Three of the four leaf essential oils showed notable invitro cytotoxic activity. Essential oils of A. glabra, A. muricata and A. squamosa showed moderate cytotoxic activities with IC50 values ranging from 12.35 to 24.21?g/ml. While the essential oils of A. cherimola showed IC50 values ranging from 7.67 to 9.22?g/ml. Leaf oils and ethanol extractives showed appreciable antibmicobial activity with variable MIC ranging from 30 to 315µg/ml. These findings suggest that A. cherimola essential oil and ethanol extract have great potential as a natural medicine for cancers and microbial infections. Keywords:Annona cherimola; A. squamosa;, A. muricata ; A. glabra;   Annonaceae;   DNA, essential   oil   composition; cytotoxicity; antimicobia

    DNA Fingerprinting, Chemical Composition, Antitumor and Antimicrobial Activities of the Essential Oils and Extractives of four Annona Species from Egypt

    Get PDF
    The leaf essential oils of four members of the Annonaceae grown in Egypt (namely; Annona cherimola, A. squamosa, A. muricata and A. glabra) have been obtained by hydrodistillation and analyzed by GC-MS in order to compare and contrast the volatile chemical compositions of these species.  The essential oils were screened for in-vitro cytotoxic activity against breast cancer (MCF-7), colon cancer (CACO) and liver cancer (HEPG2) cell lines and antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeuroginosa, Aspergillus flavus and Candida albicans. beta-elemene (25.02%), beta-caryophyllene (37.11%), bicycloelemene (23.58%) and and beta-gurjunene (42.49%), were the major constituents of Annona cherimola, A. squamosa, A. muricata and A. glabra, respectively. Ethanol extracts showed highly significant cytotoxic activities (low IC50) much more than results displayed by essential oils on breast (MCF-7), colon (CACO) and liver (HEPG2) carcinoma cell lines. Relative to breast carcinoma cell line (MCF-7), The IC50 values of ethanol extracts were 3.43, 3.89 and 4.34 ?g/ml for A. cherimola, A. squamosa and A. muricata ethanol extractives respectively. While colon carcinoma cell line (CACO) displayed IC50 values 2.82, 2.97, 3.58 and 3.89 ?g/ml for A. muricata, A. cherimola, A. glabra and A. squamosa, respectively. Liver carcinoma cell line (HEPG2) exhibited IC50 valus of 3.12, 3.43 and 3.73 for A. squamosa, A. muricata and A. cherimola, respectively. Three of the four leaf essential oils showed notable invitro cytotoxic activity. Essential oils of A. glabra, A. muricata and A. squamosa showed moderate cytotoxic activities with IC50 values ranging from 12.35 to 24.21?g/ml. While the essential oils of A. cherimola showed IC50 values ranging from 7.67 to 9.22?g/ml. Leaf oils and ethanol extractives showed appreciable antibmicobial activity with variable MIC ranging from 30 to 315µg/ml. These findings suggest that A. cherimola essential oil and ethanol extract have great potential as a natural medicine for cancers and microbial infections. Keywords:Annona cherimola; A. squamosa;, A. muricata ; A. glabra;   Annonaceae;   DNA, essential   oil   composition; cytotoxicity; antimicobia

    Magnetogravitodynamic Stability of Resistive Streaming Triple Superposed of Fluid Layers

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    Stability of Magnetohydrodynamic streaming resistive triple superposed fluid layers has been studied. The basic equations were obtained by combining ordinary hydrodynamic equations and Maxwells equations related to electromagnetic field theory. The appropriate boundary conditions have been established for this model, then we obtained the dispersion relationship. The behavior of the system in terms of whether stable or unstable has been discussed. The curves are drawn to illustrate the areas of stability and instability. The effect of different parameters on the stability and the instability of this system was studied. It is found in the magnetic field permeability coefficient and the intensity of the magnetic field values has a destabilizing influence. Also, the increase of the fluids density values has a stabilizing influence. The streaming velocity has a destabilizing influence

    Effect of Annealing and Ion Beam Irradiation on AC Electrical Properties for Gold Sputtered PM-355

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    171-181Deposition of different gold thickness on PM-355 cleaned by ethanol forming thin films using magnetron sputtering. Gold layer with thickness 300, 400, 500, 700, 1000, 1300, and 1500 nm were deposited to prepare Au / PM-355 thin films. Then, ac electrical properties response of thin films for a wide frequency range 20Hz - 5MHz were measured at room temperature. Meanwhile, the measurements of ac conductivity, dielectric constant, and dielectric loss factor were plotted at different frequencies to determine the optimum thickness. Hence, the comparison was done between optimum Au thickness thin films cleaned by two organic solvents and ethanol before annealing at different frequencies. Also, study the effect of annealing and ion beam that extracted radially from conical anode and disc cathode ion source on optimum Au thickness thin film electrical properties. It is found that the annealing increases both dielectric constant, dielectric loss, and ac conductivity of optimum Au thin film at different frequencies. Despite, the nitrogen ion beam effected on these thin films by decreasing the dielectric constant and ac conductivity for all thin films except the chloroform one. Finally, study the comparison between the annealing and followed by ion irradiation thin films. It is noticed the decrease in ac electrical conductivity and dielectric constant at different frequencies

    On Pairwise λ-Open Soft Sets and Pairwise Locally Closed Soft Sets

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    Kandil and his colleagues [10], introduced the notion of -closed soft set by involving -soft set and -closed soft set. In this paper, we give some additional properties of -closed soft sets. We also introduce and study a related new class of -spaces which lies between  and  . Moreover, we show that there exists a very important relation between the notion of -closed soft sets and the  property, ,  , . In addition, we offer the notion of -locally closed soft sets and we investigate a related new pairwise soft separation axiom  which is independent from . The relationships between the -closed soft sets and the -locally closed soft sets are obtained. Furthermore, we introduce the notion of -open soft sets and we construct supra soft topology associated with the class of -open soft sets and we present pairwise soft separation axioms related to such soft sets, namely . We provide some illustrative examples to support the results
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