Lift-off effect, resulting in detection error, which is a significant challenge that needs to be addressed defect using eddy current testing (ECT). A novel array sensor, with each unit composing of 4 excitation coils and receiving coil, proposed implement fast large-area scanning for metal sheet without lift-off interference. In addition, theoretical analysis based on Biot-Savart law applied illustrate the feasibility sensor eliminating effect. However, has also an angular sensitivity means...

Abstract The auricular conchae of 310 young Chinese people (169 men and 141 women) aged 18–28 years were classified into different groups differentiated in terms shape as a basis to designing wearable non‐slip earphones. Seven characteristic distances could be obtained accurately by defining 5 points extracting their 3‐dimensional (3D) coordinates from 3D digital models (obtained scanning ear impressions) automatically. differences statistically analyzed. Results show that the average...

Finite element analysis plays an essential role in the field of eddy current computation and for non-destructive testing applications. There are some analytical solutions that can be used to solve problems, however, most cases, there is no suitable method, i.e., test sample with arbitrary geometry or shape crack. Therefore, finite method a fundamental tool conducting investigations. A key feature using simulation being versatile but slow. In this paper, exploiting fact crack only causes...

While a lot of attention was given to shock wave reflections from wedges during the past four decades, only little work published regarding similar case blast reflection wedges. In present paper this subject is studied experimentally and theoretically/numerically. The obtained results show that geometry reflected pattern in two cases when both incident waves have same initial pressure jump across their fronts. However, different signatures (history) are observed these cases. pressures behind...

Using conduits in which a transmitted shock wave experiences abrupt changes its direction of propagation is an effective means for attenuation. An additional attenuation the obtained when medium contained inside conduit (through transmitted) suspension rather than pure gas. The present numerical study shows that adding small solid particles (dust) into gaseous phase results sharp all waves passing through conduit. It shown smaller dust diameter is, higher becomes. Increasing mass loading...

A method for measuring diffuse reflectivity using cubic cavity based on the variable port fraction was developed by oxygen P11 line at 762 nm tunable diode laser absorption spectroscopy. An experimental to determine additional path length l0 presented. We measured of a with scattering coatings different thickness. The error reduced from 0.004 0.0003 when increased 0.867(4) 0.9887(3). simulation result manifests that has potential be further higher reflectivity.

A detailed data of concha is currently not available. Therefore, the present study aimed to determine twelve morphometric measurements concha, investigate its sexual dimorphism and bilateral asymmetry, establish basic shapes for both sexes sides. The sample comprised 310 young Chinese aged 18-28 years. 141 left right ear impressions females, 169 males were collected scanned. 3D coordinates seven landmarks on each auricular obtained using scanning technology curvature theory. From landmarks,...

The measurement of metallic spherical objects in various industrial applications has a significant role guaranteeing safety and product quality, which can be realized by the eddy-current testing (ECT) technique without contact. In this study, for thickness radius nonmagnetic shells, original analytical model is simplified according to asymptotic forms modified Bessel functions. contains only elementary functions, therefore accelerates sphere property estimation employing optimization...

The ventilation system design of dry-type air-core reactor is a complex task that must determine the thermal loads to achieve maximum insulation material exploitation. In this study, temperature rise in due Joule's losses and heat dissipation by air convection, convection radiation. calculated coupled magnetic field-circuit analysis are used as input for field finite-element analysis, which directly with fluid analysis. Finally, distributions can be calculated. Therefore, performance could...

We report on the use of x-ray diffraction as a means extracting velocity profiles from non-Newtonian complex fluid under laminar flow. In particular, we applied this technique to concentrated undulating membrane system flowing through cylindrical capillary tube. The intermembrane separation d was measured function simple shear using Couette flow cell. A logarithmic dependence rate observed, while there linear relationship between fractional spacing and stress. Subsequent measurement system's...

This paper proposes a linear eddy-current feature to determine the radius of metallic ball in non-contact manner. An electromagnetic sensor with two coils is placed co-axially metal during measurement. It well known that distance between and test piece (i.e. lift-off) affects signals. In this paper, it found peak frequency inductance spectrum lift-off spacing centre coil ball. Besides, slope frequencies versus lift-offs linked The balls retrieved from experimental embedded analytical result...

The quality of steel balls influences the accuracy, motion performance and service life rolling bearing. eddy-current testing technique plays an important role in measurement bearing ball properties, including radius, electrical conductivity relative magnetic permeability. In this study, estimation method properties is proposed using multi-frequency technique. optimizes least squares problem between measured calculated coil inductance spectra through modified Newton-Raphson algorithm....

Lift-off can cause significant errors in the measurement of metallic ball thickness using eddy current method. In this paper, a triple-coil sensor, which is composed two receiving coils and one excitation coil, applied to address problem lift-off variation. There exists peak frequency feature, where value imaginary part inductance change occurs. The difference frequencies linearly proportional metal balls, with advantage reducing effect during measurements. simulation results agree well...

Abstract Cooperation search algorithm (CSA) is a new metaheuristic inspired from the team cooperation behaviors in modern enterprises and characterized by fast convergence. However for some complex problems, it may get trapped into local optima suffer premature convergence shortcoming of population updating guided only leading individuals. In this paper, an improved (CCSA) proposed incorporating mutation crossover operators DE algorithms to alleviate shortcoming. The two can be used increase...