Investigation of elastic modes propagating in multi-wire helical waveguides

Elastic waves in helical waveguides

Coupling of gap plasmons in multi-wire waveguides.

We investigate the coupling of gap plasmons in various configurations of neighboring metallic nanowires. Starting with the basic element defining a gap plasmon, consisting of two neighboring silver wires, we study the energy splitting and symmetry properties of hybridized plasmons resulting from the interaction of two wire pairs. The system is shown to display non-avoided crossings of hybridize...

investigation of single-user and multi-user detection methods in mc-cdma systems and comparison of their performances

در این پایان نامه به بررسی روش های آشکارسازی در سیستم های mc-cdma می پردازیم. با توجه به ماهیت آشکارسازی در این سیستم ها، تکنیک های آشکارسازی را می توان به دو دسته ی اصلی تقسیم نمود: آشکارسازی سیگنال ارسالی یک کاربر مطلوب بدون در نظر گرفتن اطلاعاتی در مورد سایر کاربران تداخل کننده که از آن ها به عنوان آشکارساز های تک کاربره یاد می شود و همچنین آشکارسازی سیگنال ارسالی همه ی کاربران فعال موجود در...

Paraxial Coupling of Propagating Modes in Three-Dimensional Waveguides with Random Boundaries

We analyze long range wave propagation in three-dimensional random waveguides. The waves are trapped by top and bottom boundaries, but the medium is unbounded in the two remaining directions. We consider scalar waves, and motivated by applications in underwater acoustics, we take a pressure release boundary condition at the top surface and a rigid bottom boundary. The wave speed in the waveguid...

BRUNEL UNIVERSITY Signal Processing Methods for Defect Detection in Multi-Wire Helical Waveguides using Ultrasonic Guided Waves

Non-Destructive Testing of industrial components carries vital importance, both financially and safety-wise. Among all Non-Destructive techniques, Long Range Ultrasonic Testing utilizing the guided wave phenomena is a young technology proven to be commercially valid. Owing to its well-documented analytical models, Ultrasonic Guided Waves has been successfully applied to cylindrical and plate-li...