17 results for “surface tension”

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Research ArticleOpen accessIn the abstractBiosurfactan Production by Bacillus sp. Isolated from Petroleum Contaminated Soils of Sirri IslandM. Ghayyomi Jazeh, F. Forghani, Deog-Hwan OhProblem statement: Biosurfactants are active surface components produced by some bacteria and fungi. These molecules reduce surface and interfacial tension in aqueous solutions and hydrocarbon mixtures. The most important application of biosurfactants is in oil industry to enhance oil quality and facilitate oil extraction. The aim of this study was to isolate biosurfactant producing bacteria and optimize the conditions like … …American Journal of Applied Sciences, Vol. 9, Issue 1 · 13 Jan 2012 · 8,552 accessesView PDF Cite

Research ArticleOpen accessIn the abstractBioengineering Assessment on Sloppy GroundMu'azu Mohammed Abdullahi, Nazri Bn Ali, Kamarudin Bn Haj AhmedProblem statement: Soft engineering solution of sloppy surface utilizes mechanical and hydrological effects of vegetation. The hydrological effects driven by transpiration, induces an increase in matric suction and consequently tension also increase along with the decrease of moisture. Therefore once the horizontal stress of the soil exceeds the limit of tensile strain of the soil cracks occurs. Approach: The negative … …American Journal of Environmental Sciences, Vol. 6, Issue 4 · 31 Aug 2010 · 7,242 accessesView PDF Cite

Research ArticleOpen accessIn the abstractEarthquake Resistant Design of Reinforced Soil Structures Using Pseudo Static MethodB. Munwar Basha, G.L. Sivakumar BabuProblem statement: This study presented a method to evaluate the internal stability of reinforced soil structures against tension and pullout modes of failure using pseudo-static method for earthquake conditions. Approach: Using limit equilibrium method and assuming the failure surface to be logarithmic spiral, analysis was conducted to maintain internal stability against both tensile and pullout failure of the reinforcements. For … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 3 · 30 Sep 2009 · 7,572 accessesView PDF Cite

Research ArticleOpen accessIn the abstractScreening Three Strains of Pseudomonas aeruginosa: Prediction of Biosurfactant-Producer StrainGholamreza Dehghan-Noudeh, Mohammad Hasan Moshafi, Effat Behravan et al.Problem statement: The chemical surfactants have some disadvantages; especially, toxicity and no biodegradability. Approach: Biosurfactants were the structurally diverse group of surface-active molecules synthesize by micro-organisms. The microbial surfactants were interesting, because of the biodegradable and have many applications in industry, agriculture, medicine. Results: In the present study, the production of biosurfactant by three strains of Pseudomonas aeruginosa (PTCC 1074, … …American Journal of Applied Sciences, Vol. 6, Issue 8 · 31 Aug 2009 · 7,552 accessesView PDF Cite

Research ArticleOpen accessIn the abstractAn Investigation of Valve Lift Effect on Air Flow and Coefficient of Discharge of Four Stroke Engines Based on ExperimentAbdul Rahim Ismail, Rosli Abu Bakar, SeminThe coefficient of discharge (CD) is defined as the ratio of actual discharge to ideal discharge. In an engine environment, ideal discharge considers an ideal gas and the process to be free from friction, surface tension, etc. Coefficients of discharge are widely used to monitor the flow efficiency through various engine components and are quite useful in improving the performance … …American Journal of Applied Sciences, Vol. 5, Issue 8 · 31 Aug 2008 · 7,431 accessesView PDF Cite

Research ArticleOpen accessIn the abstractFinite Element Analysis of Plasticity- Induced Fatigue Crack Closure with Singular ElementR. Rahgozar, H. Saffari, R. TabatabaeiDeveloping a new method is presented to compute crack opening values in planar geometries using the crack surface nodal force distribution under minimum loading as determined from finite element analyses (FEM). In this technique, two-dimensional elastic-perfectly plastic finite element analyses of middle-crack tension (MT) geometry is conducted to study fatigue crack closure and to calculate the crack opening values under … …American Journal of Applied Sciences, Vol. 4, Issue 6 · 30 Jun 2007 · 6,850 accessesView PDF Cite

Research ArticleOpen accessIn the abstractNon Destructive Tests of Structural Bonds by Guided Ultrasonic Waves: Effect of a Surface Pretreatment or a Localized DefectValentina Vlasie, Martine RousseauThe aim of this study was to propose a non destructive method to test the mechanical quality of a bond aluminium/epoxy/aluminium. Thus, for each aluminium/epoxy interface, an intermediate interface modelling between a simple geometrical interface and an interphase (3D material medium), i.e. a 2D material medium. In order to describe the surface stresses, we introduce the surface free energy (the … …American Journal of Applied Sciences, Vol. 2, Issue 3 · 31 Mar 2005 · 6,883 accessesView PDF Cite