Low‐frequency function generator/controller using an X–Y recorder

1977 ◽  
Vol 48 (11) ◽  
pp. 1500-1502
Author(s):  
John H. Myers ◽  
Charles F. Frost
Keyword(s):  
Low Frequency ◽  
Frequency Function ◽  
Function Generator

scholarly journals An inexpensive, low-frequency function generator

1973 ◽  
Vol 5 (5) ◽  
pp. 442-443
Author(s):  
Martin J. Steinbach
Keyword(s):  
Low Frequency ◽  
Frequency Function ◽  
Function Generator

scholarly journals Effect of cochlear implant electrode insertion on middle-ear function as measured by intra-operative laser Doppler vibrometry

2009 ◽  
Vol 123 (7) ◽  
pp. 723-729 ◽  
Author(s):  
N Donnelly ◽  
A Bibas ◽  
D Jiang ◽  
D-E Bamiou ◽  
C Santulli ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Middle Ear ◽  
Low Frequency ◽  
Laser Doppler ◽  
Frequency Function ◽  
Laser Doppler Vibrometry ◽  
Variable Effect ◽  
Custom Made ◽  
Electrode Insertion ◽  
The Impact

AbstractHypothesis:The aim of this study was to investigate the impact of cochlear implant electrode insertion on middle-ear low frequency function in humans.Background:Preservation of residual low frequency hearing with addition of electrical speech processing can improve the speech perception abilities and hearing in noise of cochlear implant users. Preservation of low frequency hearing requires an intact middle-ear conductive mechanism in addition to intact inner-ear mechanisms. Little is known about the effect of a cochlear implant electrode on middle-ear function.Methods:Stapes displacement was measured in seven patients undergoing cochlear implantation. Measurements were carried out intra-operatively before and after electrode insertion. Each patient acted as his or her own control. Sound was delivered into the external auditory canal via a speaker and calibrated via a probe microphone. The speaker and probe microphone were integrated into an individually custom-made ear mould. Ossicular displacement in response to a multisine stimulus at 80 dB SPL was measured at the incudostapedial joint via the posterior tympanotomy, using an operating microscope mounted laser Doppler vibrometry system.Results:Insertion of a cochlear implant electrode into the scala tympani had a variable effect on stapes displacement. In three patients, there was little change in stapes displacement following electrode insertion. In two patients, there was a significant increase, while in a further two there was a significant reduction in stapes displacement. This variability may reflect alteration of cochlear impedance, possibly due to differing loss of perilymph associated with the electrode insertion.Conclusion:Insertion of a cochlear implant electrode produces a change in stapes displacement at low frequencies, which may have an effect on residual low frequency hearing thresholds.

scholarly journals Application Of Diadynamic Currents To Reduce Pain

2021 ◽  
Vol 3 (2) ◽  
pp. 59-62
Author(s):  
Amalia Solichati Rizqi
Keyword(s):  
Data Analysis ◽  
Low Frequency ◽  
Sampling Technique ◽  
The Body ◽  
Wilcoxon Test ◽  
Frequency Function ◽  
Exclusion Criteria ◽  
Signed Rank ◽  
Background Pain ◽  
Parametric Statistics

Background: Pain has become a separate complaint or disease, not only as a means of protecting the body or a symptom of other diseases. With increasing age, a person will experience a decrease in physiological functions that can affect the system in the body. Diadynamic currents are part of electrecal stimulation which has a low frequency function to reduce pain.Methods:This is an experimental research with a quantitative approach. The sampling technique used nonprobability sampling based on the inclusion and exclusion criteria. The data analysis used was non-parametric statistics, namely by using the Wilcoxon signed rank test.Results: Based on the result of the Wilcoxon test showed that the value. Sig. is 0.000, which is less than 0.05. By giving a diadynamic current, the pain felt by someone will be reduced.Conclusion: diadynamic currents can be used to reduce pain

scholarly journals Frequency Response Characteristics of Rogowski Coil with Active Integrator for Lightning Measurement

2020 ◽  
Vol 18 (1) ◽  
pp. 45-53
Author(s):  
Busayapol Paophan ◽  
Anantawat Kunakorn ◽  
Peerawut Yutthagowith ◽  
Kazuo Yamamoto
Keyword(s):  
Frequency Response ◽  
Rogowski Coil ◽  
Current Measurement ◽  
Measuring System ◽  
Frequency Function ◽  
Electrical System ◽  
Function Generator ◽  
Response Characteristics ◽  
Lightning Current ◽  
Frequency Response Characteristics

This paper presents frequency response characteristics of a Rogowski coil which is developed with an active integrator. Experiments are performed in a laboratory with a frequency function generator as a source. The frequency responses of the Rogowski coil and the integrator are recorded with both magnitude and phase in order to verify the capability in measuring lightning current waveshapes.  For availability in lightning current measurement in the electrical system, the developed Rogowski coil is specifically designed as a clamp on device. The standard lightning current waveshape of the first positive impulse (10/350μs) is simulated to investigate the measuring system. It is found that the frequency bandwidth of the Rogowski coil with the integrator developed in this paper is proper in lightning current measurement.

scholarly journals Evaluation of the Capability of the Multigrid Method in Speeding Up the Convergence of Iterative Methods

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Iman Harimi ◽  
Mohsen Saghafian
Keyword(s):  
Convergence Rate ◽  
Boundary Conditions ◽  
Laplace Equation ◽  
Multigrid Method ◽  
Low Frequency ◽  
Dirichlet Boundary Conditions ◽  
Frequency Function ◽  
Frequency Error ◽  
Multigrid Algorithm ◽  
The Difference

The performance of the multigrid method and the effect of different grid levels on the convergence rate are evaluated. The two-, three-, and four-level V-cycle multigrid methods with the Gauss-Seidel iterative solver are employed for this purpose. The numerical solution of the one-dimensional Laplace equation with the Dirichlet boundary conditions is obtained using these methods. For the Laplace equation, a two-frequency function involving high- and low-frequency components is defined. It is observed that, however, the GS method can smooth out the high-frequency error components properly, but because the difference scheme for Laplace equation is remarkably concise, in the fine grids, a very large number of iterations are needed for extending the boundary conditions into the domain. Furthermore, the obtained results reveal that the number of necessary iterations for convergence is reduced considerably by employing the two-level multigrid algorithm. But increasing the number of levels of algorithm does not have any significant effect on the convergence rate in this study.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

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.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

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.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

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.

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