LCR Meter Research Articles

Role of moisture content, temperature, and frequency on dielectric behaviour of red lentil and Kabuli chickpea in relation to radio frequency heating

Dielectric constant (ε′) and loss factor (ε″) of lentil (grain and flour) and chickpea (split and flour) were determined over four moisture content (MC), seven temperature, and seven frequency using a computer-controlled precision LCR meter built for measurements at low frequencies. Both properties increased with MC and temperature but decreased as frequency increased. The decrease was prominent at high MC and temperature as frequency increased from 5 to 30 MHz for all samples. At 13.56 MHz, penetration depth of lentil grain and flour ranged from 1.77 to 34.25 m and 1.78 to 61.07 m, while for split chickpea and chickpea flour, it ranged from 0.99 to 31.79 m and 1.29 to 105.75 m, respectively. The resulting penetration depth indicated that thick layer of samples can be processed with adequate heating uniformity using radio frequency heating as an innovative option in industrial processing of grains. Regression models generated in this study could be used to predict ε′ and ε″of grains at low frequencies (5 to 30 MHz) and temperature of up to 90°C, and for modeling and simulation of radio frequency heating.

Effects of temperature, analysis and modelling uncertainties on the reliability of base-isolated bridges in Eastern Canada

The seismic response of base-isolated bridges depends strongly on the seismic isolation system (SIS) properties, which typically vary under the effect of multiple conditions, such as temperature. The North American Bridge Design Codes and the EN-Eurocode 8 recommend a bounding analysis method in order to consider the effect of SIS properties variation with different conditions. However, this method is not founded on a rigorous probabilistic approach, and thus does not impact the reliability of base-isolated bridges. This paper presents an estimate of the seismic reliability and its variation range for a typical two-span concrete base-isolated bridge located in Montreal, a typical site for Eastern Canada. Temperature, bidirectional horizontal seismic hazard and the main parameters affecting the resistance of bridge components, specifically, dimensions, material properties of the bridge pier and SIS properties are all modelled as Random Variables (RVs). Bridge failure associated with two limit states is examined: (1) damage at the pier base by lack of bending moment capacity and (2) SIS failure due to a lack of displacement capacity. The Monte-Carlo method is used to evaluate each limit state’s reliability and probability of failure. In earlier studies, epistemic uncertainties (EUs) associated with the modelling and seismic analysis method were either ignored or not thoroughly considered. A main innovation of the present study is to include EUs associated with the seismic response analysis method and the lead core heating of the lead rubber bearing SIS are modelled as RVs. Their margins of variation are estimated, and their probabilistic distribution parameters are identified. The effects of these EUs on the reliability of the bridge are investigated. The effect of the natural rubber material type on the reliability of the bridge is also studied. Preliminary results show that, due to any of these uncertainties, the global reliability index is within a range of [3.36–3.62], whereas the reliability index when these EUs are not included is 3.49. When including the epistemic uncertainty associated with the response analysis method, the reliability index of the pier base flexural behaviour limit state varies between 3.52 and 3.76(as compared to a value of 3.56 obtained without including the above EUs). Similarly, when including the epistemic uncertainty associated with the heating effect, the reliability index of the SIS displacement limit state varies between 3.31, for an extreme effect, and 3.49 for a more representative effect (as compared toa value of 3.51 obtained without including the above EUs). Earlier studies considering fewer variability sources showed that the global seismic reliability varies between 3.47 and 3.52 for the same typical two-span base-isolated bridge in Montreal. In these studies, the SIS material and geometrical properties were considered deterministic. Other sites in Quebec have shown comparable reliabilities to those at the studied site, with a maximum variation of 3% between sites.

Antimicrobial performance and charge transport mechanism of Poly(N-methylpyrrole)-boron nitride composite

This study reports structural, dielectric and antibacterial properties of Poly(N-methylpyrrole)-Boron nitride (PNMPy-BN) composite synthesized via an interfacial polymerization method. Characterization and morphological analyses were performed by Fourier transform infrared (FT-IR), X-ray diffraction (Xrd), Fluorescence (FL), Thermogravimetric (TG), Scanning electron microscopy (SEM) and Atomic Force Microscope (AFM) analyses. Temperature-dependent dielectric measurements were carried out by an LCR meter. For the antimicrobial activity tests, the disk diffusion method was used. BN nanoparticles decreased the π-π stacking distance of the polymer chains, while they showed a quenching effect on the fluorescence emission intensity of polymer matrix. For the degradation process of PNMPy, the extrapolated onset temperature increased from 292 to 317 °C after filling process. Surface analyses showed that BN nanoparticles reduced the average roughness and size of agglomerated structures on the polymer surface. In dielectric analysis, it was determined that the conduction mechanism of PNMPy and its composite was compatible with the correlated barrier hopping (CBH) model, but for the composite there was a little tunneling effect in the conductivity at high temperatures. Furthermore, filling process decreased the minimum hopping distance of the charge carriers in the polymer matrix. BN nanoparticles increased the inhibition zone diameter of PNMPy between 2 and 8 mm against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis bacterial species.

Automatically extracting surfaces of reinforced concrete bridges from terrestrial laser scanning point clouds

Three-dimensional (3D) geometric bridge models play an important role in bridge inspection, assessment, and management. Laser scanning nowadays offers a cost-efficient method to capture dense, accurate 3D topographic data of surfaces of the bridge. However, given the typical complexity of bridges, current workflows using commercial software to construct a bridge model still require intensive labour work. This paper presents a new approach to automatically extract the point cloud of surfaces of structural components of box and slab-beam bridges. The proposed method consists of 3 Parts: (1) point-to-surface, (2) superstructure and (3) substructure extraction. The method uses both spatial point clouds and contextual knowledge to extract point cloud subsets corresponding to surfaces of individual bridge components in a consecutive order from superstructure to substructure. For each bridge component, two levels of extraction are (1) coarse extraction to separate candidate points of the component from the full data set and (2) fine filtering to obtain final 3D points of individual surfaces using cell- or voxel-based region growing (CRG or VRG), followed by a connected surface component (CSC) method. An experimental test on one box-girder and one slab-beam bridges shows that the proposed method successfully extracts all surfaces of bridge components with the lowest F1-score of 0.93 based on a point-based evaluation. Moreover, a shape similarity evaluation also shows that discrepancies between extracted surfaces and ground truth ones are no larger than 0.82 for the area overlap ratio and 0.59 degrees for the angular deviation. The proposed method contributes to the automatic generation of 3D geometric bridge models and to give point clouds of individual surface for damage identification.

Perbandingan Metode Pelaksanaan Standar Konstruksi Jembatan Bailey dengan Pelaksanaan di Lapangan

Bailey Bridge is a steel frame bridge that is generally used as a temporary emergency bridge. Although this type of bridge hasbeen widely used, one of them is at the location of the Pesaguan-Kendawangan Road, but there are still some obstacles in thesteel frame assembly process. Therefore, the researcher wants to make a comparison between the standard method ofimplementing the Bailey Bridge in the Temporary Bridge Technology book and the method implemented in the location. Thepurpose of this study was to determine the implementation method of bridge assembly at the location of Jalan PesaguanKendawangan and compare it with the standard method. The research was carried out using observation and interviewmethods with informants to obtain information about the assembly of the Bailey bridge at the location. The results ofobservations and interviews were analyzed by comparison with the standard Bailey Bridge. The data obtained shows thatthere are nine steps of implementing the assembly of Bailey Bridge components at the location of the PesaguanKendawangan Road Section, starting from the assembly of base plate components, panel components, panel post Icomponents, transom components, pin components, bracing components, raker components, panel post II components, andfinally the deck plate component. The comparison results show that 6 out of 10 bridge assembly parameters have met existingstandards.

A New Method to Determine the Steel Fibre Content of Existing Structures—Evaluation and Validation

The in-situ measurement of the content and orientation of steel fibres in concrete structures is of great importance for the assessment of their specific mechanical properties, especially in the case of repair. For existing structures, the actual fibre content as well as the orientation of the fibres, which is based on many factors such as casting or compacting direction, is typically unknown. For structural maintenance or rehabilitation, those factors have to be determined in order to apply meaningful structural design calculations and plan necessary strengthening methods. For this reason, a new method based on the analysis of drilling cores of concrete structures has been established. The newly developed non-destructive test setup used in this research consists of a framework for cylindrical specimens in combination with an LCR meter to determine the electrical resistance of the fibre reinforced concrete. In combination with a suitable FEM model, concretes with fibre contents up 80 kg/m3 were analysed to derive a first model to assess the actual fibre content of steel fibre reinforced concretes. After a calibration of the literature’s equation by use of an adjusted aspect ratio for the analysis of drilling cores, the estimation of the fibre content is possible with high accuracy for the tested material combination. The results show that the newly developed test method is suitable for the rapid and non-destructive structural diagnosis of the fibre content of steel fibre reinforced concrete based on drilling cores using electrical resistivity measurements.

МОДЕРНИЗИРОВАННАЯ УСТАНОВКА ДЛЯ ФИЗИЧЕСКОГО МОДЕЛИРОВАНИЯ ПРОМЫВКИ ЗАСОЛЕННЫХ ПОЧВ

The purpose of the study is to improve the design of the installation through the use of soil moisture concentration sensors and digital LCR meter XJW01. The digitalization of hydrotechnical melioration of agricultural lands in the Russian Federation requires the active use of mathematical models for the movement of moisture fl ows, nutrients, air, and heat in the soil profile. The parameters of these flows in the laboratory are determined by the methods of physical modeling. Improving the design of installations for the physical modeling of soil processes increases the accuracy of measurements and reduces the labor intensity of work. The modernized facility for physical modeling of saline soil leaching includes electrical sensors for measuring the concentration of soil moisture. The sensors are equipped with conductive plates and conductive windings. Digital LCR meter XJW01 automatically detects the sensor as an electrical oscillatory circuit and fixes its quality factor. The quality factor of the sensor depends on the concentration of soil moisture that fi lls its body. The operating prototype of the installation was tested. In the concentration range of NaHCO3 solution from 0 to 350 mmol/dm3 , the quality factor of the sensors varies from 282±2.1 to 221±2.7 (signifi cance level P = 0.99, number of degrees of freedom k = 4, and Student’s test t = 4.60).

Ferroelectric and dielectric behaviour of MWCNT/poly urethane composite

This study includes the fabrication of multi walled CNT reinforced polyurethane composite (MWCNT/PU) which are characterized for Ferroelectric and dielectric behaviour. Ferroelectric property (P-E loop and I-V curve) leakage current behavior of MWCNT/PU composite were studied using P-E loop tracer. It is found that electric Polarization depends on the frequency because of mass associated with the change in the dipole. Leakage current behavior is analyzed and discussed. Dielectric parameters like Dielectric constant and Dissipation factor were studied at different temperature (30–70 °C) through LCR meter. It is found that the dielectric constant and dissipation factor increased as temperature increases. The dissipation factor increases with frequency and temperature.

Comparison of four-terminal-pair 1 pF, 10 pF, 100 pF and 1000 pF capacitance standards at frequencies of 10 kHz, 100 kHz, 1 MHz and 10 MHz (APMP.EM-S15)

Main textIn order to calibrate an LCR meter, metrological traceability of capacitance above 10 kHz becomes more and more important. For this reason, NIM (National Institute of Metrology, China)，NPLI (National Physical Laboratory, India) and NIMT (National Institute of Metrology, Thailand) have carried out research on capacitance metrology from 10 kHz to 10 MHz.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Transparent, Breathable Temperature and Humidity Sensor using Ion Gel and Polymer Thin Films

In this study, a transparent and highly breathable thin-film temperature and humidity sensor was developed as a concept proof for multimodal patchable devices using ion gels. The sensor can detect temperature and humidity selectively by using two types of ionic liquids for sensing layers. Ionic liquids were compatibilized with polymers to form a semi-solid state, called ion gels. Polydimethylsiloxane (PDMS) thin film was used for substrates. Carbon nanotube (CNT) transparent electrodes were fabricated onto PDMS substrate by spray coating method. Ion gel sensing layers were also spray-coated onto CNT electrodes. The fabricated sensor exhibited more than 80 % visible light transmittance and 3.9 times higher water vapor transmission than skin evaporation. LCR meter was used for measuring the impedance of temperature and humidity sensors. As a result, selective detection of temperature and humidity was achieved by using two types of ion gels with different hydrophilicity. These results suggest the easy fabrication of multimodal patchable devices by using various types of ionic liquids.

Investigation of Ceramic Based Composites by Using 2D Graphene Filler

The ceramic composites of sodium bismuth titanate with reduce graphene oxide NBT/rGO of different compositions were fabricated by solid state sintering method and characterized. In this work, the graphene oxide (GO) and reduce graphene oxide (rGO) was successfully synthesized by Hummer’s modified method which is confirmed by FTIR and XRD results. The reduce graphene oxide used as 2D filler in piezoelectric creamic material. The crystalline structure of NBT/rGO composite was confirmed by X-ray diffraction with rhombohedral symmetry. The dispersion of rGO in the ceramic can be detect by the optical microcopy images. The electrical conductivity of sodium bismuth titanate shows increase at higher values of frequency and conductivity nanocomposites of different wt% were start decreases up to certain value of frequency. The broadening of peaks in frequency explicit plots of electrical conductivity with the help of LCR Meter (Impedance Capacitance and Resistance). The crystalline size of reduced graphene oxide and NBT is calculated by Scherrer’s formula of XRD peaks.

Effect of Fe substitution on the structural, microstructural and dielectric properties of sodium bismuth titanate

Lead free sodium bismuth titanate (NBT) is widely being studied as an emerging room temperature multiferroic and as a ferroelectric material with potential to replace toxic lead based ceramics. Various elements can be substituted in the A-site or B-site to improve its electrical and magnetic properties. In this work, pure and Fe substituted NBT having the chemical formula Na0.5Bi0.5Ti(1-x)FexO3 (x = 0.00, 0.02) were synthesized using sol gel auto ignition method to study the effect of Fe substitution on the properties of NBT. XRD analysis confirmed the rhombohedral symmetry of the synthesized samples and the crystallite size of the samples were calculated using Scherrer’s formula. The morphological property of the samples was studied from the SEM images. UV–Visible Spectroscopy method was employed to study the optical properties of the samples. The dielectric properties of the samples were measured as a function of frequency in the range 100 Hz to 1 MHz at room temperature and also as a function of temperature in the range of 298 K- 473 K using an Agilent HP4284 LCR meter. Usual dispersive behavior of dielectric constant was observed for both the samples at the studied temperature range. Study of frequency and temperature dependence of the AC conductivity suggested that the conduction process in the materials is thermally activated. Jonchers’ universal power law was used to fit the AC conductivity curves to describe the dynamics of charge carrier with suitable conduction mechanism.

Capacitive Readout System for Micro Sensors and Actuators With Automatic Parasitic Cancellation

In this article, a capacitive readout system with automatic parasitic capacitance cancellation function is designed and implemented. The readout system is implemented with discrete components on a board level. The parasitic cancellation is realized by matching a digital programmable capacitor to the parasitic capacitance using a PI controller. The function of the readout system is verified by using standard ceramic capacitors and a MEMS micromirror device. Capacitance measurements up to 35 pF for ceramic capacitors are performed, the maximum error between the measurement results of the circuit and an LCR meter is 0.07 pF. For MEMS micromirror, the circuit cancels the parasitic capacitance of 32.63 pF and realizes a measurement error within 0.06 pF. The proposed system can be used as a proof-of-concept platform demonstrating the feasibility of the generic parasitic cancellation method for MEMS sensors and actuators.

Influence of temperature variations on the dielectric parameters of thermally reduced graphene oxide

Large-scale production of graphene remains a great challenge in which the oxidation of graphite is a promising approach for it. Graphene has unique thermal, electrical, and mechanical properties, but it is in the most common solvents insoluble. Graphene oxide can be considered as an insulator or semiconductor material. As compared to the properties of graphene and graphene oxide (GO), the reduced graphene oxide (rGO) behaves as an intermediate state between graphene and GO. Graphene oxide has been successfully synthesized from graphite powder via Hummer’s method and followed by thermal treated at 800 °C for the reduction GO in order to obtain rGO. This work elucidates the preparation method of GO and rGO step-by-step in detail. Structural characterization by X-ray diffraction of the synthesized rGO explains that the preparation and reduction of GO were effective. The morphology and structure of GO and rGO were analyzed using Scanning Electron Microscopy (SEM). Fourier Transform Infrared (FTIR) analysis displayed the disappearing of some oxygen functional groups in rGO in comparison to GO, as well as some peaks of rGO were flattened due to the removal of the carbonyl group. The aim of this paper is to analyze the dielectric properties of rGO as a function of temperature. The pellet of rGO was prepared to study the dielectric properties with respect to temperature in the range of 25 °C–300 °C for selected frequencies using LCR meter. The relative dielectric constant (ε′), dielectric loss factor (ε′′), dielectric loss tangent (tanδ), and the impedance of rGO were found to depend highly on the extent of temperature.

Barium Doping Effects on Frequency-dependent Dielectric Properties of Cobalt Ferrite Nanoparticles

The chemical method was employed for the preparation of barium doped cobalt (Co1-xBaxFe2O4) . Different concentrations of barium were doped in cobalt “CoFe2O4” to get Co1-xBaxFe2O4; x = 0, 0.25, 0.50, 0.75 and 1.0 . X-ray diffraction (XRD) spectroscopy was employed for the analysis of crystallographic structure and Debye-Scherrer formula was employed for the determination of average size. The morphological study and size calculation of Co1-xBaxFe2O4 were carried out by using scanning electron microscopy (SEM). Energy X-ray (EDX) spectroscopy was used for the analysis of these . The modes of different atoms present in these were investigated using Fourier transform infrared (FTIR) spectroscopy. The dielectric parameters such as capacitance, real and imaginary parts of dielectric constant, loss tangent and ac-conductivity were inspected using LCR meter. Significant improvement in charge storage and transport properties were achieved with the doping of barium in CoFe2O4 .

In situ Polymerization of Polyaniline/Samarium Oxide - Anatase Titanium Dioxide (PANI/Sm2O3-TiO2) Nanocomposite: Structure, Thermal and Dielectric Constant Supercapacitor Application Study.

Pure and varying weigh ratio of Sm2O3-TiO2 modified polyaniline nanocomposite has been successfully synthesized using in situ polymerization of aniline solution with Sm2O3-TiO2 binary oxide. The nanocomposite have been characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-photoelectron microscopy (XPS), Field emission-scanning electron microscope (FE-SEM), transmission electron microscopy (TEM) thermogravimetric analysis (TGA) and LCR meter. The XRD results show synthesis anatase TiO2 phase with tetragonal structure and (monoclinic and cubic) mixture structure of Sm2O3. The FE-SEM and TEM measurements appear preparing spherical nanoparticles that covered fiber morphology of polyaniline and successfully in situ polymerization process. The TGA measurements are obtain high thermal stability for polyaniline after incorporation by Sm2O3-TiO2 binary oxide nanoparticles. LCR measurement is obtained that the DC conductivity, dielectric constant and dielectric loss of nanocomposite is larger than pure polyaniline and the electric properties increase with increasing the concentration of nanoparticles.

Non-Destructive testing to detect multiple cracks in reinforced concrete beam using electromechanical impedance technique

One of the most common engineering constructions is the Reinforced Concrete (RC) structure. As a result, it's critical to monitor the structure's health constantly. Significant causes of damage in RC structures are overloading, deficient design, fatigue; these factors induce cracks. These induced cracks severely impact the capacity of RC structures. It's critical to surveil the existence and progression of cracks early on in the damage cycle to prevent catastrophic structural failure. Electromechanical Impedance (EMI) is an effective non-destructive testing technique that uses smart materials-based Lead Zirconate Titanate (PZT) to detect cracks. The EMI technique generates admittance ((Y)) ̅ comprising of conductance, G and susceptance, B. The structure's diagnosis of damage signature is a plot of G over a frequency range. Any variation in the plot of G indicates damage in the structure. The proposed method is experimentally validated using surface-bonded PZTs on the lab-sized RC beam of grade M25. Two PZTs are bonded near each support, with one in the RC beam's centre. The RC beam is put through a four-point bending test in the experiment. Shear and flexural cracks in the beam have been monitored continuously by extracting admittance signatures from the surface bonded PZTs using an LCR meter. The admittance signatures measured at the pristine and damaged stage are compared to locate the damages. The lateral and vertical shifts in conductance signatures indicated cracks in the beam. RMSD and MAPD are used as pattern recognition techniques to quantify the variations of damaged signatures with undamaged signatures of the host structure. It demonstrates that EMI method based on PZT transducers have the ability to detect the shear and flexural cracks of the beam, and the pattern recognition techniques can effectively quantify the damage levels. The proposed method of damage detection is quite effective and sensitive to concrete.

Influence of Graphene Oxide on AC-conduction of Hematite Nanoparticles

The chemical sol-gel method was opted for the preparation of hematite (α-Fe2O3) . The of graphene oxide (GO) and α-Fe2O3 {i.e. (GO)x/α-Fe2O3; x = 0, 0.5, 1.0 and 1.5 wt.%} were synthesized using two-step method. The dispersion of GO and α-Fe2O3 was done using Toluene for the preparation of (GO)x/α-Fe2O3 . The crystal structure, surface morphology and modes of these were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. XRD spectra confirmed the phase formation and crystal structure of (GO)x/α-Fe2O3 . The SEM images displayed that α-Fe2O3 were successfully dispersed over GO . FTIR spectra showed two transmittance bands at 464 cm-1 and 537 cm-1 correspond to Fe-O bond. LCR meter was used for the acquisition of frequency-dependent dielectric and impedance measurements of the samples. The variation in frequency-dependent dielectric and impedance properties was observed as GO were hybridized with α-Fe2O3 . Furthermore, the advancement in dielectric and impedance properties give evidence that the synthesized (GO)x/α-Fe2O3 could be worthy useful for high frequency devices and energy storage appliances.

Dielectric and physical properties of aqueous solutions of 1,3-dimethylurea at 298.15 K

The complex dielectric function ε*(ω) = ε'(ω)-jε“(ω) is studied for aqueous solutions of 1,3-dimethylurea (1,3-DMU) at constant temperature 298.15 K across the frequency range 20 Hz to 2 MHz. Dielectric properties are measured using Agilent E 4980 precision LCR meter with a four terminal liquid test fixture (Agilent-16452). From measured dielectric data, the frequency dependent electric modulus M*(ω), electrical conductivity σ*(ω) and complex impedance spectra Z*(ω) were obtained. Effects of concentration variation of 1,3-DMU in distilled water on dielectric and electrical properties are discussed to gain information about the self-aggregative nature of 1,3-dimethylurea and dissociation process in aqueous solutions. Density, viscosity, and refractive index of all the solutions are measured and reported.

Phase and Electrical Properties of Rice Husk Silica-based Na2FeSiO4 Precursors Sintered at High Temperature

The aim of this work is to characterize the phase and electrical properties of Na2FeSiO4 precursor synthesized by the sol-gel technique and then sintering with a holding period of 10 h. The FTIR analysis indicates the presence of Na-O, Fe-O, Si-O and Si-O-Si groups. Their phases were analyzed using XRD coupled with qualitative and quantitative analysis. Meanwhile, the electrical properties were characterized using UV-Vis DRS and LCR meter. The phase analysis revealed that the samples were dominated by SiO2 and Na2FeSiO4 and were followed by Fe2O3, Fe2SiO4 and Na2SiO3. There was no substantial differences in phase composition over the sintering temperature range of 805-815 ºC. However, the volume of cell units in each phase increased gradually with an increase in sintering temperature and was followed by the increasing electrical conductivity of the samples.