Switching Transient Traced Scheme Based on Sinusoidal Waveform to Reduce EMI for IGBTs

2021 ◽  
Author(s):  
Jianan Chen ◽  
Dong Jiang ◽  
Wei Sun
Keyword(s):  
Sinusoidal Waveform

Influence of Supporting Characteristics on Sphericity of Ceramic Balls in Rotated Dual-Plates Lapping Process

2009 ◽  
Vol 69-70 ◽  
pp. 69-73 ◽  
Author(s):  
Bing Hai Lv ◽  
Ju Long Yuan ◽  
F. Cheng ◽  
Fan Yang
Keyword(s):  
Numerical Calculation ◽  
Fourier Analysis ◽  
Support System ◽  
Spherical Surface ◽  
Surface Generation ◽  
Shape Error ◽  
Lower Natural Frequency ◽  
Sinusoidal Waveform ◽  
Higher Spin ◽  
Ball Surface

Ceramic balls have become an important component in advanced bearings, and the sphericity of balls is a key qualification focused in lapping process. An investigation on the effect of dynamic behavior of ball support system on the performance of ball lapping in rotated dual-plates lapping method is carried out. Sinusoidal waveform in terms of Fourier analysis is employed to express the shape error of the ball surface, and a dynamic model for support is setup. It is found with numerical calculation that the variation of lapping load lags behind the variation of the shape error for the damping of support. A lower natural frequency of the support system, higher spin speed of balls and a larger value of spin angle in RDP lapping are better to rectify the shape error of balls and reduce the lagged effect. It is concluded that dynamics of lapping system must be taken into consideration in order to understand comprehensively the spherical surface generation mechanism.

Sinusoidal Waveform

2003 ◽  
pp. 65-73
Author(s):  
Edward V. Barnat ◽  
Toh-Ming Lu
Keyword(s):  
Sinusoidal Waveform

scholarly journals Fatigue Strength of Acacia Mangium

2019 ◽  
pp. 29-32
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Ultimate Tensile Strength ◽  
Endurance Limit ◽  
Acacia Mangium ◽  
Vertical Axis ◽  
Life Cycles ◽  
Grain Angle ◽  
Sinusoidal Waveform ◽  
Fatigue Endurance

The works in this study is to investigate and understand the nature of Acacia mangium axial fatigue strengths under repeated stress. Acacia mangium trees were cut to produce oven-dried Small Clear Specimens that were then tested until fracture in parallel to the grain direction. This was carried out in order to discover its Ultimate Tensile Strength, which was later identified as 143.87 MPa, in parallel to the grain direction (0° grain angle). In the next phase, specimens were tested for fatigue strengths in repeated-tensile sinusoidal waveform loading at 100 Hz frequency. The stress levels for this test were at the ratios of 80, 60, 40, 30, 20 and 10% of the Ultimate Tensile Strength (0° grain angle) for the construction of Life (N) - Stress (S) plots and empirical correlation. It was observed that the Acacia Mangium N-S (Wöhler) plots have an exponential correlation with the N – intercept of vertical axis at five (5) million cycles, while the intercept of horizontal, S – axis, was at 143.87 MPa. The study also observed that Acacia mangium achieves 106 life cycles at 10% stress level. For this reason, it is concluded that the material has a fatigue endurance limit at 10% of the Ultimate Tensile Strength for 0° grain angle.

Design, Manufacturing and Testing of Small Shaking Table

2018 ◽  
Vol 7 (4.20) ◽  
pp. 426 ◽  
Author(s):  
Asad H. Humaish ◽  
Mohammed S. Shamkhi ◽  
Thualfiqar K. Al-Hachami
Keyword(s):  
Dynamic Response ◽  
Shaking Table ◽  
Single Frequency ◽  
Main Body ◽  
Maximum Displacement ◽  
Maximum Acceleration ◽  
Geotechnical Centrifuge ◽  
Concrete Gravity Dams ◽  
Sinusoidal Waveform ◽  
Model Weight

The seismic performance and the dynamic response of concrete gravity dams can be verified by several techniques. Both geotechnical centrifuge apparatus (under N-g values) and shaking table (under 1-g) are the commonly used techniques in the world. This paper deals with designing, manufacturing, and testing of small shaking table to investigate different geotechnical and engineering problems. The main body of the designed shaking table consists of steel frame (local iron) manufactured as a hollow box with steel plate, 6mm in thickness and one-direction movable platform (as a basket carrying the container of the model).  Inside this main box, all the mechanical parts that work as one system to generate the motion of the seismic wave with an acceleration that needed to the test.  The facilities of this shaking table, the movable base has a dimension of 0.8m x1.2m and the platform mass approximately 2 kN, the maximum allowable model weight of 10kN, the range of frequency from 0 to 20 Hz, the maximum acceleration amplitude of 1.2g and maximum displacement of 14mm. It can simulate only the single frequency motion (i.e. sinusoidal wave). The measured accelerations at different soil model level for the tested shaker under 0.6g sinusoidal waveform gave a reasonable prediction for the dynamic response and the amplification characteristics.  

scholarly journals Testing Sensitivity of A-Type Residual Current Devices to Earth Fault Currents with Harmonics

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2044
Author(s):  
Stanislaw Czapp
Keyword(s):  
Power Systems ◽  
Electric Shock ◽  
Low Voltage ◽  
Wide Spectrum ◽  
Residual Current ◽  
Motor Speed ◽  
Earth Fault ◽  
Fault Currents ◽  
Wide Range ◽  
Sinusoidal Waveform

In many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in low-voltage power systems is commonly performed with the use of residual current devices (RCDs). In the presence of harmonics, the RCDs may have a tripping current significantly different from that provided for the nominal sinusoidal waveform. Thus, in some cases, protection against electric shock may not be effective. The aim of this paper is to present the result of a wide-range laboratory test of the sensitivity of A-type RCDs in the presence of harmonics. This test has shown that the behavior of RCDs in the presence of harmonics can be varied, including the cases in which the RCD does not react to the distorted earth fault current, as well as cases in which the sensitivity of the RCD is increased. The properties of the main elements of RCDs, including the current sensor, for high-frequency current components are discussed as well.

scholarly journals The Effect of Repetitive Head Impact in Sensory Reweighting in Collision College Athletes

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S25.2-S26
Author(s):  
Fernando Vanderlinde Santos ◽  
Jaclyn Caccese ◽  
Felipe Yamaguchi ◽  
John Jeka
Keyword(s):  
Repeated Measures ◽  
Sport Participation ◽  
Collegiate Athletes ◽  
Vestibular Stimulation ◽  
High Amplitude ◽  
Head Impact ◽  
Group Effect ◽  
Contact Sport ◽  
Sensory Reweighting ◽  
Sinusoidal Waveform

ObjectiveTo compare sensory reweighting for upright stance between collegiate collision and non-contact sport athletes.BackgroundThe potentially adverse effects of repetitive head impact (RHI) exposure through routine collision sport participation have become a major public health concerns.Design/MethodsThirty male collegiate athletes were grouped by sport type, including collision (n = 15, 21.2 ± 2 years, 85.9 ± 13.8 kg, 179.7 ± 8.2 cm) and non-contact (n = 15, 20.8 ± 2.1 years, 72.9 ± 4.8 kg, 178.3 ± 4.3 cm) sport athletes. Participants underwent a standing balance assessment; they experienced simultaneous perturbations to visual, vestibular, and somatosensory systems. The visual stimulus consisted of 500 pyramids displayed on a virtual reality cave and translated in the anterior-posterior direction at 0.2 Hz in a sinusoidal waveform. The vestibular stimulus consisted of binaural-monopolar galvanic vestibular stimulation (GVS) at 0.36 Hz in a sinusoidal waveform. The somatosensory stimulus consisted of bilateral Achilles’ tendon vibration at 0.28 Hz in a square waveform with equal on/off times. Different frequencies were chosen for each modality so that we could calculate the gain to each stimulus independently. There were four conditions: two conditions of each high amplitude (0.2 m) and low amplitude (0.8 m) visual scene translation and two conditions of each vibration on and vibration off. The leg segment gain to each modality was compared between groups and across conditions using a repeated-measures ANOVA.ResultsThere were no changes in leg segment gain to vision (i.e. group effect; F = 2.624, p = 0.094, η2 = 0.086), gain to GVS (F = 1.341, p = 0.266, η2 = 0.46), or gain to vibration (F = 3.124, p = 0.088, η2 = 0.100). In addition, there were no changes in sensory reweighting for any modality (i.e. condition X group effect; vision, F = 0.074, p = 0.788, η2 = 0.003; GVS, F = 0.547, p = 0.46, η2 = 0.019; vibration, F = 0.734, p = 0.399, η2 = 0.026).ConclusionsOur findings suggest that there are no differences in sensory reweighting between collegiate collision and non-contact sport athletes. Despite concerns that RHI exposure through routine collision sport participation may result in balance disturbances, our results do not support this association.

scholarly journals Synchronization of mouse islets of Langerhans by glucose waveforms

2011 ◽  
Vol 301 (4) ◽  
pp. E742-E747 ◽  
Author(s):  
Xinyu Zhang ◽  
Arij Daou ◽  
Tuan M. Truong ◽  
Richard Bertram ◽  
Michael G. Roper
Keyword(s):  
Spectral Analysis ◽  
Preliminary Evidence ◽  
Dominant Frequency ◽  
Microfluidic System ◽  
Main Peak ◽  
Fura 2 ◽  
Glucose Levels ◽  
Sinusoidal Waveform ◽  
The Individual

Pancreatic islets secrete insulin in a pulsatile manner, and the individual islets are synchronized, producing in vivo oscillations. In this report, the ability of imposed glucose waveforms to synchronize a population of islets was investigated. A microfluidic system was used to deliver glucose waveforms to ∼20 islets while fura 2 fluorescence was imaged. All islets were entrained to a sinusoidal waveform of glucose (11 mM median, 1 mM amplitude, and a 5-min period), producing synchronized oscillations of fura 2 fluorescence. During perfusion with constant 11 mM glucose, oscillations of fura 2 fluorescence were observed in individual islets, but the average signal was nonoscillatory. Spectral analysis and a synchronization index (λ) were used to measure the period of fura 2 fluorescence oscillations and evaluate synchronization of islets, respectively. During perfusion with glucose waveforms, spectral analysis revealed a dominant frequency at 5 min, and λ, which can range from 0 (unsynchronized) to 1 (perfect synchronization), was 0.78 ± 0.15. In contrast, during perfusion with constant 11 mM glucose, the main peak in the spectral analysis corresponded to a period of 5 min but was substantially smaller than during perfusion with oscillatory glucose, and the average λ was 0.52 ± 0.09, significantly lower than during perfusion with sinusoidal glucose. These results indicated that an oscillatory glucose level synchronized the activity of a heterogeneous islet population, serving as preliminary evidence that islets could be synchronized in vivo through oscillatory glucose levels produced by a liver-pancreas feedback loop.

The Effects of Total Harmonics Distortion for Power Factor Correction at Non-Linear Load

2016 ◽  
Vol 7 (2) ◽  
pp. 551 ◽  
Author(s):  
R. A. Rani ◽  
Shakir Saat ◽  
Yusmarnita Yusop ◽  
Huzaimah Husin ◽  
F. K. Abdul Rahman ◽  
...  
Keyword(s):  
Power Factor ◽  
Single Phase ◽  
Power Factor Correction ◽  
Harmonic Distortion ◽  
The Other ◽  
Linear Load ◽  
Non Linear ◽  
Sinusoidal Waveform ◽  
Non Linear Load ◽  
The Relationship

This paper presents the effect of total harmonic distortion (THD) in power factor correction (PFC) at non-linear load. This study focuses on the relationship between THD and PFC. This is beacuse,the power factor affects THD. This occurs in power system as we have variety of loads, i. e linear load or non-linear load. The variety of loads will influence the sinusoidal waveform, which comes out from harmonic distortion. Thus, based on this study, we can compare the effective method in improving the power factor as it will not disturb the performance of THD. The focus of study is on the single phase load, where the voltage restriction is 240 V.  The analysis will  only focus on the consumer, which depends on the variety of non-linear load. Besides, the parameters for analysis are based on the percentage of THD and the value of power factor. The instrument for measuring the parameter is based on power factor correction device or technique. On the other hand, the method that was used for this study is based on simulation which incorporated the Multisim software. At the end of ths study, we can choose the most effective method that can be used to improve the power factor correction without disturbing the THD.

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