توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Effect of ionic resistance on cathodic delamination resistance of bituminous coatings
نویسنده(ها): ،
اطلاعات انتشار: اولین همایش بین المللی قیر، سال
تعداد صفحات: ۷
Two types of bituminous coating, bitumen and coal tar pitch, were investigated using electrochemical impedance spectroscopy (EIS) and cathodic delamination measurements. The softening point of both bituminous materials was 80oC. The Bituminous coatings applied on shot blasted steel with 100 µm thickness and then subjected to EIS and cathodic delamination tests in %3.5 NaCl w\w solution. The ionic
resistance of coatings were extracted from bode and Nyquist diagrams by fitting of appropriate electrical model. The cation diffusion mechanism in cathodic delamination process examined for each of coatings. Results revealed effective role of ionic resistance on cation diffusion process and rate of delamination in cathodic delamination test.<\div>

۲Study of Coating Thickness and Electrolyte Concentration on Cathodic Disbonding of Polyurethane Coated Mild Steel via EIS
نویسنده(ها): ، ،
اطلاعات انتشار: سومین کنگره بین المللی رنگ و پوشش، سال
تعداد صفحات: ۹
The influence of the coating thickness and electrolyte concentration parameters on cathodic disbondment of polyurethane coating applied on solvent degreased mild steel was assessed using electrochemical impedance spectroscopy (EIS) at open circuit potential (OCP). In order to polarize the samples, sacrificial magnesium anode imposing potential –1.46VAg\AgCl was employed. Through taking advantage of polarization resistance as well as total impedance extracted from EIS data, coating thickness and electrolyte concentration revealed a significant impact on the diffusion mechanism.<\div>

۳Micro mechanisms of load transfer in a hybrid unidirectional fiber–reinforced epoxy composite with broken fibers
نویسنده(ها): ،
اطلاعات انتشار: دومین کنفرانس بین المللی کامپوزیت، سال
تعداد صفحات: ۶
In this paper effects of mechanical and physical properties of polymer matrices of hybrid unidirectional fiber–reinforced composites with broken fibers are investigated, numerically and analytically. It is assumed that all fibers lie in one direction while loaded by a force po at infinity. The matrix and the fibers are considered homogeneous, isotropic and linearly elastic. To study effects of hybridization two types fiber arrangements are presented. The analytical solution is obtained using shear–lag and improved shear–lag theory. The analytical results based on two models, were compared to those of finite element values. Comparison of the predicted shear stresses and average normal stresses to finite element analysis demonstrates that improved shear–lag model can be used to rapidly estimate the average normal stress distribution in the various constituents, although the interfacial shear stresses are less accurate.<\div>

۴Stress transfer modeling in viscoelastic polymer matrix composites with an internal damage
نویسنده(ها): ،
اطلاعات انتشار: دومین کنفرانس بین المللی کامپوزیت، سال
تعداد صفحات: ۶
A viscoelastic analysis of a multilayered composite model is carried out to investigate the timedependent stress transfer between elastic unidirectional Fibers and viscoelastic matrix for loading in the axial direction. The laminate is subjected to an elliptical damaged zone of radii r1 and r2. The stress state in the composite is solved at incremental time intervals to obtain the stabilized solution, and the time required to reach a stable state. To study effect of viscoelasticity on unidirectional composite material used The Wiechert model. It is assumed that all long fibers lie in a finite width laminate. A hexagonal arrangement is postulated to deduce the equilibrium equations. Upon proper use of boundary and boundness conditions, stress and displacement fields are derived within the laminate and as well as elliptic hole surrounding. In order to simulate almost a crack and a circular hole, two values of r1\r2 assume 0 and 1, respectively. The solution is obtained analytically as well as numerically, using finite element technique. The analytical results on stress concentration factors were compared to those of finite element values. A close match is observed between the two methods<\div>

۵INVESTIGATION ON THE EFFECT OF TIME AND ACIDITY ON THE INHIBITORY ACTION OF 2–METHYL BENZIMIDAZOLE
نویسنده(ها): ،
اطلاعات انتشار: دومین کنفرانس بین المللی نفت، گاز و پتروشیمی، سال
تعداد صفحات: ۱۰
The inhibitory action of a model benzimidazole derivative, namely 2–methyl benzimidazole (2–MBI) on mild steel in different concentration HCl solutions was studied by weight loss. The results were used to describe the effect of environment corrosiveness on the inhibitory action of 2–MBI, on the other hand the effect of time was taken into account. Inhibition efficiencies increased with increasing concentration of inhibitor and HCl. The quantum chemical descriptors including: EHOMO, ELUMO, energy gap (E), dipole moment (μ), hardness (ƞ), softness (σ), electronegativity index (χ) and fraction of electrons transferred (N), that are most relevant to the potential action of a molecule as corrosion inhibitor, have been calculated in vacuum, water and protonated form of the molecule. Electronic parameters of these three inhibitors have been studied using DFT\B3LYP, and HF methods with 6–31G (d, p) basis set<\div>
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