scholarly journals Internal Rot Detection with the Use of Low-Frequency Flaw Detector

2014 ◽  
Vol 13 (2) ◽  
Author(s):  
Marek Proskórnicki ◽  
Grzegorz Ligus
2013 ◽  
Vol 23 (3) ◽  
pp. 235-246
Author(s):  
Seong-Seung Kang ◽  
Chin-Surk Ko ◽  
Cheong-Bin Kim ◽  
Bo-An Jang
Keyword(s):  

2019 ◽  
pp. 36-49
Author(s):  
A. M. Slyadnev

Considered the use in the production of aviation equipment (airplanes and helicopters), polymer composites differing in enhanced operational and technological properties, such as strength, rigidity, level of working temperatures, etc. Examples are given of using newer gliders in multilayer structures MS-21 aircraft and Mi-38 helicopter of modern composite materials. The review of defects of multilayer structures made of polymer composite materials arising at the stage of manufacturing, storage, transportation and operation of aircraft, and low-frequency methods of their control is presented. It is noted that the main of low-frequency control methods are the impedance method and the method of free oscillations proposed by domestic scientists.The principle of operation of the first portable multifunctional computerized pulsed flaw detector DAMI-C09, combining impedance, impact and eddy current ND methods, is described. It is noted that the flaw detector can be used for manual and automated, as part of a robotic complex, to identify bundles, nonglues and other violations of the integrity of composites, honeycomb structures and glued structures, to determine corrosion centers, surface and internal defects in non-ferromagnetic materials. A feature of the flaw detector is the simplified preparation process for work due to the automated mode of tuning the signal in amplitude or phase using a spectrum analyzer, documenting the monitoring results with the ability to transfer to a computer and subsequent processing with the help of a special APM of the Flaw Detector. Examples of the effective use of the flaw detector in the production and operation of aviation equipment are given.


2017 ◽  
Vol 6 (2) ◽  
pp. 109-117
Author(s):  
Фролов ◽  
Ivan Frolov

The article presents information on methods bucking wood core rot. Offering flaw detector used as X-ray unit upgraded to sight through the X-ray transmission type, and it is paired with 3D scanner. The article presents the scheme bucking of stems with heart rot for different companies depending on the volume and type of products. Used peeled or not burking whips, de-pending on the technological production chain.


Author(s):  
K. Hama

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.


Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.


Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.


Author(s):  
G. Y. Fan ◽  
J. M. Cowley

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.


Author(s):  
M. T. Postek ◽  
A. E. Vladar

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.


1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.


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