Determination of harmonic contributions using active filter: Theoretical and experimental results

Author(s):  
Franklin Clement Veliz ◽  
Sergio Luis Varricchio ◽  
Cristiano de Oliveira Costa
2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.


2018 ◽  
Vol 233 ◽  
pp. 00025
Author(s):  
P.V. Polydoropoulou ◽  
K.I. Tserpes ◽  
Sp.G. Pantelakis ◽  
Ch.V. Katsiropoulos

In this work a multi-scale model simulating the effect of the dispersion, the waviness as well as the agglomerations of MWCNTs on the Young’s modulus of a polymer enhanced with 0.4% MWCNTs (v/v) has been developed. Representative Unit Cells (RUCs) have been employed for the determination of the homogenized elastic properties of the MWCNT/polymer. The elastic properties computed by the RUCs were assigned to the Finite Element (FE) model of a tension specimen which was used to predict the Young’s modulus of the enhanced material. Furthermore, a comparison with experimental results obtained by tensile testing according to ASTM 638 has been made. The results show a remarkable decrease of the Young’s modulus for the polymer enhanced with aligned MWCNTs due to the increase of the CNT agglomerations. On the other hand, slight differences on the Young’s modulus have been observed for the material enhanced with randomly-oriented MWCNTs by the increase of the MWCNTs agglomerations, which might be attributed to the low concentration of the MWCNTs into the polymer. Moreover, the increase of the MWCNTs waviness led to a significant decrease of the Young’s modulus of the polymer enhanced with aligned MWCNTs. The experimental results in terms of the Young’s modulus are predicted well by assuming a random dispersion of MWCNTs into the polymer.


1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.


2014 ◽  
Vol 698 ◽  
pp. 466-471
Author(s):  
Oleg V. Panchenko ◽  
Alexey M. Levchenko ◽  
Victor A. Karkhin

Specimens of various sizes are used to determine hydrogen content in deposited metals in such standards as ISO 3690, AWS A 4.3, and GOST 23338 while measuring methods are the same. It causes problems in comparison of experimental results and brings up the following question: what kind of specimen size is optimal to determine hydrogen content? An optimal specimen size was estimated using a calculation method. Experimental and calculation results obtained by using specimens with estimated dimensions were compared to the results obtained by using the specimen with dimensions of 100*25*8 mm to determine hydrogen content in a deposited metal.


1973 ◽  
Vol 51 (6) ◽  
pp. 605-609 ◽  
Author(s):  
C. Boulet ◽  
N. Lacome ◽  
P. Isnard

From the analysis of the available experimental results, a vibrational dependence of N2O line widths is shown, which can be explained, applying the Anderson–Tsao–Curnutte theory. But no dependence on ν of any of the molecular parameters can be deduced. In the last part, we have pointed out the effect on the determination of the quadrupole moment of assuming a nonvanishing octupole moment for N2O.


2013 ◽  
Vol 543 ◽  
pp. 171-175
Author(s):  
Jose Andrés Somolinos ◽  
Rafael Morales ◽  
Carlos Morón ◽  
Alfonso Garcia

In the last years, many analyses from acoustic signal processing have been used for different applications. In most cases, these sensor systems are based on the determination of times of flight for signals from every transducer. This paper presents a flat plate generalization method for impact detection and location over linear links or bars-based structures. The use of three piezoelectric sensors allow to achieve the position and impact time while the use of additional sensors lets cover a larger area of detection and avoid wrong timing difference measurements. An experimental setup and some experimental results are briefly presented.


1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.


1989 ◽  
Vol 54 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Květuše Říčná ◽  
Jaroslav Matouš ◽  
Josef P. Novák ◽  
Vladimír Kubíček

Liquid-liquid equilibrium at 5, 25, and 50 °C was measured in the water-ethanol-toluene system. Special attention was paid to the determination of distribution coefficient of ethanol. Besides, the composition and boiling point of azeotropic mixture at normal pressure were determined.


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