نتایج جستجو برای: guided waves and frequency response
تعداد نتایج: 17055911 فیلتر نتایج به سال:
Introduction and purpose: Cardiac response to body core temperature variation measured with the very low-frequency parameter of heart rate variability. The aim of this study was to investigate the variability of very low frequency due to different temperatures of aerobic training in water and dry. Materials and methods: 40 academic active male were selected as research subjects. Then, all subje...
the purpose of this study was to investigate the relationship between family functioning and marital adjustment humor couples are due to the nature and objectives of the research and application of methods for its implementation correlation was used. the study population consisted of all the couples in the city who uses random cluster sampling of 200 students were selected as sample. data from ...
Ultrasonic Guided Wave inspection of pipes has been extensively used in various industries such as oil, gas and petrochemical industries. The behavior of guided waves in straight pipes is well known but the presence of features like pipe bends, welds may distort the receiving signals. It is therefore a challenging task to study the behavior of guided waves through these features. However, the 3...
a novel and ultra low cost isfet electrode and measurement system was designed for isfet application and detection of hydronium, hydrazinium and potassium ions. also, a measuring setup containing appropriate circuits, suitable analyzer (advantech board), de noise reduction elements, cooling system and pc was used for controlling the isfet electrode and various characteristic measurements. the t...
In order fully to exploit energy of wind power the construction elements of the wind turbine should be inspected periodically. Ultrasonic air-coupled technique using guided waves has been selected for inspection of wind turbine blades, because only one side access is enough and no contact is needed. Dispersion curves of phase velocities as well as leakage losses versus frequency were calculated...
Ultrasonic guided waves have been extensively applied for non-destructive testing of plate-like structures particularly pipes in past two decades. In this regard, if a structure has a simple geometry, obtained guided waves' signals are easy to explain. However, any small degree of complexity in the geometry such as contacting with other materials may cause an extra amount of complication in the...
This study carries out the edge-reflection analysis of guided waves in a 3-D plate. First, we excite an incident guided wave by applying a normal traction on the surface of a 3-D plate. The excited wave field is obtained in the frequency and wavenumber domains. Secondly, we perform the edge-reflection analysis in the frequency and wavenumber domains by applying the mode-decomposition method to ...
chapter i provides an overview of structural linguistics and touches upon the saussurean dichotomies with the final goal of exploring their relevance to the stylistic studies of literature. to provide evidence for the singificance of the study, chapter ii deals with the controversial issue of linguistics and literature, and presents opposing views which, at the same time, have been central to t...
the present study was an attempt to conduct a contrastive analysis between general english (ge) and english for specific purposes (esp) texts in terms of cohesion and cohesive devices. to this end, thirty texts from different esp and ge textbooks were randomly selected. then they were analyzed manually to find the frequency of cohesive devices. cohesive devices include reference, substitution, ...
Guided wave ultrasonic testing has been widely used for nondestructive and long-range evaluation of diverse mechanical structures, such as pipes plates. In general, a large number guided modes exist even in the simplest geometries, they exhibit highly dispersive characteristics. Thus, sophisticated excitation methods elaborate modal analyses need to be implemented excite, acquire, process well-...
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