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The purpose of this study is to demonstrate the usage of three-dimensionally (3D) printed polylactic acid (PLA)-carbon black (CB) conductive polymer composite in the measurement of the void fraction and liquid level.

PLA-CB conductive polymer composite is 3D printed through fused deposition modelling (FDM) technique and used as a capacitive sensor for void fraction measurement and liquid level sensing. The sensitivity of 3D printed ring and concave type capacitive sensors are compared for void fraction measurement. The effect of electrode length, thickness and pipe dimension on the capacitance achievable for the particular void fraction is studied. Concept of fringing capacitance is used for the sensing of liquid level.

Compared to the concave design comprising four electrodes, the ring-type capacitive sensor produced better results in void fraction measurement. Increase in pipe diameter and electrode length results in the enhancement of capacitance arising from specific void fraction. For a 100 mm diameter pipe, the capacitance of the 150 mm-long concave electrode (0.4 mm thick) increased from 9.98 to 67.77 pF as the void fraction decreased from 100% to 0%. Development of the fringing capacitance in 3D printed PLA-CB composite helps in the measurement of liquid level. Both parallel finger topology and interdigital electrode configuration are able to sense the liquid level.

Ability of the 3D printed conductive PLA-CB composite to act as a capacitive sensor is experimentally analysed. Performance of different electrode configuration is tested for both void fraction measurement and liquid level sensing. Results of experimentation prove that FDM printed PLA-CB composite is suitable for the void fraction and liquid level measurement.

This paper aims to present the capacitance characterization of tapered dielectrophoresis (DEP) microelectrodes as micro-electro-mechanical system sensor and actuator device. The application of DEP-on-a-chip (DOC) can be used to evaluate and correlate the capacitive sensing measurement at an actual position and end station of liquid suspended targeted particles by DEP force actuator manipulation.

The capability of both, sensing and manipulation was analysed based on capacitance changes corresponding to the particle positioning and stationing of the targeted particles at regions of interest. The mechanisms of DEP sensor and actuator, designed in DOC applications were energized by electric field of tapered DEP microelectrodes. The actual DEP forces behaviour has been also studied via quantitative analysis of capacitance measurement value and its correlation with qualitative analysis of positioning and stationing of targeted particles.

The significance of the present work is the ability of using tapered DEP microelectrodes in a closed mode system to simultaneously sense and vary the magnitude of manipulation.

The integration of DOC platform for contactless electrical-driven with selective detection and rapid manipulation can provide better efficiency in in situ selective biosensors or bio-detection and rapid bio-manipulation for DOC diagnostic and prognostic devices.

In some developing countries, vehicles are often over‐loaded, which causes road accidents and damage to road surfaces. Currently, large measuring facilities are used to measure the vehicle‐loading on highways. A major limitation is that they can measure vehicle‐loading at fixed locations only. This paper seeks to present an on‐vehicle loading measurement system with capacitance and acceleration transducers.

A description and analysis of the system are presented.

The capacitance transducers sense the variation in distance between electrodes, using the on‐vehicle leaf springs as weighing elastomers. The acceleration transducers deal with the influence of acceleration to vehicle‐loading measurement. The major advantage of this system over the existing systems is that both static and dynamic loading can be measured.

This system is simple and easy to install.

The paper shows that with this system both a driver and an inspector can check vehicle‐loading at any time and any location through radio communication, thus identifying over‐loaded vehicles on highways.

Electrical capacitance tomography (ECT) and electrical resistance tomography (ERT) are promising techniques for multiphase flow measurement due to their high speed, low cost, non-invasive and visualization features. There are two major difficulties in image reconstruction for ECT and ERT: the “soft-field”effect, and the ill-posedness of the inverse problem, which includes two problems: under-determined problem and the solution is not stable, i.e. is very sensitive to measurement errors and noise. This paper aims to summarize and evaluate various reconstruction algorithms which have been studied and developed in the word for many years and to provide reference for further research and application.

In the past 10 years, various image reconstruction algorithms have been developed to deal with these problems, including in the field of industrial multi-phase flow measurement and biological medical diagnosis.

This paper reviews existing image reconstruction algorithms and the new algorithms proposed by the authors for electrical capacitance tomography and electrical resistance tomography in multi-phase flow measurement and biological medical diagnosis.

The authors systematically summarize and evaluate various reconstruction algorithms which have been studied and developed in the word for many years and to provide valuable reference for practical applications.

The oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film thickness of the bearing.

On a specially designed test rig, measurement of the capacitance is used to monitor the oil film thickness of ball bearing. A corrected film thickness formula taking account of the influences of non-Newtonian shear thinning and thermal is introduced to predict the oil film thickness of ball bearing. And then the film thickness distribution and the corresponding capacitances are calculated.

Measurement and calculation of oil film thickness in a ball bearing are carried out under various rotating speeds and external loads. By comparing the calculated capacitances with measured results, it can be concluded that the calculated results obtained by the amended film thickness formula are much closer to the test findings than the classical computed values according to Hamrock–Dowson.

A new corrected film thickness formula is introduced in predicting oil film thickness of ball bearing and verified by the series of experiments according to capacitance method.

The purpose of this paper is to present work on the incorporation of capacitors into printed circuit boards (PCB) as a method to measure moisture content and follow moisture diffusion under ground planes.

PCBs were manufactured of FR‐4 incorporating different arrangements and sizes of capacitors formed between the tracks on adjacent layers of the PCB. The boards were placed in an 85°C and 85 per cent relative humidity (RH) environment to absorb moisture before baking at temperatures of 80, 110 or 125°C with the capacitance periodically measured. The effect of ground planes with different densities of plated and non‐plated through holes (PTH) has been studied by placing capacitors between ground planes.

Parallel plate capacitors embedded within a PCB showed a 10 per cent capacitance increase going from a dry state to being saturated with moisture in an 85°C and 85 per cent RH environment. The slow ingression of moisture under the capacitance planes meant that the measured capacitance change did not reflect the moisture content of the remainder of the board well. Capacitor plates with slots for the moisture to penetrate were also investigated, with the increase in capacitance found to show good correlation with the increase in board mass. In investigating moisture under ground planes, either by decreasing the hole density or by plating the holes, the time for moisture to diffuse out of the board was found to increase due to the lower exposed area on the PCB.

The paper illustrates a method that can be applied to PCB manufacturing to assess the moisture content of a board prior to reflow.

This paper aims to report the investigations of capacitors and inductors embedded into printed circuit boards (PCBs) designed in various layouts.

The research were focused on the components embedded into four-layer PCBs with different structures of the inner layers. Three special capacitive laminates for manufacturing of thin-film embedded capacitors and several types of coils in the form of a spiral, meander and solenoid are described. In addition, a part of the spiral-type coils was formed with an aperture in the center in which the magnetic core, made of soft magnetic composites’ material was placed to increase the coil inductance.

Various constructions of embedded capacitors and coils were designed and manufactured. Capacitance and loss tangent of capacitors to determine the repeatability of the production process were determined. Capacitor’s long-term stability analysis was performed by exposing test samples to elevated temperatures (70, 100 or 130°C), realized with the aid of heating plate, for at least 160 h. The temperature characteristics for the capacitance and loss tangent from 15 to 100°C were determined. Also the induction of different designs and layouts coils was determined.

The wide parameters’ characterization of capacitors and coils embedded into PCBs allow the analysis of their properties with regard to their practical application. The promising results of the realized measurements show that the capacitors and induction coils with studied structures can be widely used in the construction of embedded circuits into PCBs (e.g. filters, radio frequency identification systems and generators).

To make individualized men's basic upper garment patterns without sleeves, the authors developed a measuring garment that measures necessary body dimensions and angles all together. Additionally, the authors proposed a method for making individualized basic body block patterns using the obtained dimensions and angles.

The authors decided on the locations of the dimensions of the body required for making the individualized garments. The authors then sewed multiple stretchable capacitance sensors to corresponding locations on a stretchable T-shirt. To obtain the dimensions with sensors of short length, the authors indirectly obtained each length from the relationship between the actual body length and the capacitance of the sensor. Beforehand, the authors obtained linear-approximation equations for the relationship between actual body dimensions and the capacitance of sensors for five participants and a dummy. The authors then used the measuring garment and the equations to obtain the body dimensions of another six participants. The authors compared the obtained and actual body dimensions to verify the equations. The authors made individualized upper-garment patterns without sleeves and garments for the 11 participants with the obtained dimensions and angles. The authors verified the proposed method in wearing tests comparing garments designed using the proposed method with conventionally designed garments.

Using the measuring garment, the authors obtained body dimensions close to actual body dimensions. A pattern of the individualized basic upper garment using the obtained dimensions and angles could be drawn. Compared with the conventional patterns, the individualized patterns had notable differences in the locations of the shoulder point and side neck point and directions of the shoulder line, which relate to the shoulder shape (i.e. square, sloping, forward, or backward). In wearing tests, all participants declared that the individualized garment better fitted their shoulders than the conventional garment without tightness around the shoulders, neck, and armpits. The proposed method with the developed measuring garment was thus found to be effective in designing individualized garments.

This paper presents the possibility of not only measuring body dimensions but also designing individualized basic upper garments using the proposed measuring garment. The proposed measuring garment will assist the efficient manufacture of individualized upper garments without a three-dimensional scanner or special skills.

Crystallization is the process widely used for components separation and solids purification. The systems for crystallization process evaluation applied so far, involve numerous non-invasive tomographic measurement techniques which suffers from some reported problems. The purpose of this paper is to show the abilities of three-dimensional Electrical Capacitance Tomography (3D ECT) in the context of non-invasive and non-intrusive visualization of crystallization processes. Multiple aspects and problems of ECT imaging, as well as the computer model design to work with the high relative permittivity liquids, have been pointed out.

To design the most efficient (from a mechanical and electrical point of view) 3D ECT sensor structure, the high-precise impedance meter was applied. The three types of sensor were designed, built, and tested. To meet the new concept requirements, the dedicated ECT device has been constructed.

It has been shown that the ECT technique can be applied to the diagnosis of crystallization. The crystals distribution can be identified using this technique. The achieved measurement resolution allows detecting the localization of crystals. The usage of stabilized electrodes improves the sensitivity of the sensor and provides the images better suitable for further analysis.

The dedicated 3D ECT sensor construction has been proposed to increase its sensitivity in the border area, where the crystals grow. Regarding this feature, some new algorithms for the potential field distribution and the sensitivity matrix calculation have been developed. The adaptation of the iterative 3D image reconstruction process has also been described.

Within the framework of image reconstruction in cylindrical electrical capacitance tomography (ECT) sensors, the purpose of this study is to select the structure of a sensor in terms of number and size of the electrodes, to predict the radius and the position of a single circular shape lying in the cross-section defined by the sensor electrodes.

Nonlinear black-box models using a set of physically independent capacitances and least-square support vector machines models selected with a sophisticated validation method are implemented.

The coordinates of circular shapes are well estimated in fixed and variable permittivity environments even with noisy data. Various numerical experiments are presented and discussed. Sensors formed by three or four electrodes covering 50 per cent of the sensor perimeter provide the best prediction performances.

The proposed method is limited to the detection of a single circular shape in a cylindrical ECT sensor.

This method can be advantageously implemented in real-time applications, as it is numerically cost-effective and necessitates a small amount of measurements.

The contribution is two-fold: a fast computation of a circular shape position and radius with a satisfactory precision compared to the sensor size, and the determination of a cylindrical ECT sensor architecture that allows the most efficient predictions.