نتایج جستجو برای: guided waves and frequency response

تعداد نتایج: 17055911  

2012
M. N. Toksoz C. H. Cheng

The propagation of seismic waves in an open borehole is reviewed. The principal wave types are the refracted P and S waves and the two guided waves pseudo-Rayleigh and Stoneley. The dispersion properties of the gUided waves are analyzed. An efficient method of computing synthetic microseismograms is described. The relative effects of the borehole. fluid and formation properties on the propagati...

2016
Zhenhua Tian Cara A.C. Leckey Lingyu Yu

This paper presents the phased array beamforming and imaging using guided waves in anisotropic composite laminates. A generic phased array beamforming formula is presented, based on the classic delay-and-sum principle. The generic formula considers direction-dependent guided wave properties induced by the anisotropic material properties of composites. Moreover, the array beamforming and imaging...

امیرحسینی, طاهره, عابدینی, عباس,

Slow magneto-acoustic waves are often observed in polar plumes and active region fan loops. The observed periodicities of these waves are in the range of 1- 40 minutes. Mainly, the ratio of damping time to the oscillation period is less than 2 (equal to the ratio damping length to the wave length), which corresponds to the strong damping regime. In general, slow magneto-acoustic waves can be da...

Journal: :Journal of Nonlinear Optical Physics & Materials 2016

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

acknowledgements i wish to express my gratitude to all those who have helped me in preparing this thesis. i would like to express my deep gratitude to my respected advisor dr. kourosh akef, whose advice and comments helped me in the early stages of the research and throughout the writing process. i would also like to express my gratitude to dr. hajar khanmohammad whose invaluable guidance he...

2009
A. Demma

Lo screening di tubazioni utilizzando il metodo ad onde guidate è una realtá assodata sia in Italia che nel resto del mondo. I metodi PND tradizionali sono metodi per il controllo di punti o di aree ad estensione limitata. Inoltre il target della ispezione diventa di anno in anno più complesso a causa dell’invecchiamento delle strutture e delle carenze tecniche di alcuni metodi PND classici, ev...

A Tavakoli Golpaygani, F Nouri L Ataee M M Movahedi M Taheri, S Amani

Background: The increasing use of telecommunication devices such as Wi-Fi modems and mobile phones in the recent years can change the cellular structure of microorganisms so the generation of electromagnetic waves has led to concern in the community whenever be exposed to these fields and may have harmful effects on human health.Material and Methods: Standard strains of bacteria were prepared o...

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