توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Implementation of a SQUID–Based NDE System for Detection of Hidden Cracks and Comparison with an Efficient Proposed FEM Algorithm
نویسنده(ها): ، ، ،
اطلاعات انتشار: دومین کنفرانس بین المللی بازرسی فنی و آزمون غیرمخرب، سال
تعداد صفحات: ۵
A 2–D scanning SQUID–Based NDE system for testing of room temperature stationary samples in unshielded environments has been designed and implemented (in SERL Laboratory, http:\\serl.sharif.edu\). Using our NDE system with white noise level of about 50 mF0\Hz–1\2 at 500Hz (in unshielded environment) and with a nonmagnetic 2–D robot, we performed NDE scans of hidden cracks in aluminum sheets. We have also designed a FEM solution algorithm for electromagnetic simulation of the NDE scans. The algorithm divides the whole electromagnetic problem in two more simple problems which results in a great extent saving of commutating memory usage and simulation time. Using these two approaches, it is shown that our experimental results match the simulations very well.<\div>

۲NICS Rate Evaluation for Some Substituted Aromatic Rings : B3LYP Study
نویسنده(ها): ،
اطلاعات انتشار: دومین همایش ملی نفت، گاز و پتروشیمی، سال
تعداد صفحات: ۷
The NICS–rate indicator is introduced as a new aromaticity scale. The attendance of the maximum\minimum in the NICS–rate curve of a molecule shows to aromaticity\antiaromaticity of the system. In this research the optimized structure of six and four member conjugated rings were calculated by B₃LYP method, 6–311++G**(d,p) basis sets, and Gaussian03w program. After optimization the structure of rings, the NMR or the magnetic field above the rings from zero to about 3.0 angstrom was calculated by locating the Ghost atoms in the each place (NICS). The results are very interesting and show that the NICS–rate of six member rings are increases as the number of F , NO₂ and CF₃ atoms increases. . In the same trend increasing the F and CF₃ number attached to four rings decreases the antiaromaticity of them.<\div>

۳Evaluation of Aromaticity NICS of The Substituted Cyclobutadiene Molecule : B3LYP Study
نویسنده(ها): ،
اطلاعات انتشار: اولین همایش ملی فناوری های نوین در شیمی و مهندسی شیمی، سال
تعداد صفحات: ۵
Aromaticity can also be considered as strength of magnetic field around the cyclic molecules is occurred when the delocalization and resonance of electrons in rings exists. In this research the optimized structures of Cyclobutadiene molecules substituted with electronegative substitutions were calculated by B3LYP method, 6–311++G(d,p) basis sets, and Gaussian03w package. After optimization the structure of rings, the NMR or the magnetic field above the rings from zero to about 3 angstrom was calculated by locating the ghost atoms in the each place (NICS). The results are very interesting and similar in all cases. The result in all molecules show that the antiaromaticity of substituted four member rings are decreases as the number of substitution atoms increases.<\div>
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