Abstract: Electromagnetic flow meter by measuring the varying of magnetic flux, which is related to the velocity of conductive flow, can measure the rate of fluids very carefully and precisely. Electromagnetic flow meter operation is based on famous Faraday's second Law. In these equipments, the constant magnetostatic field is produced by electromagnet (winding around the tube) outside of pipe and inducting voltage that is due to conductive liquid flow is measured by electrodes located on two end side of the pipe wall. In this research, we consider to 2-dimensional mathematical model that can be solved by numerical finite difference (FD) solution approach to calculate induction potential between electrodes. The fundamental concept to design the electromagnetic flow meter, exciting winding and simulations are come out by using MATLAB and PDE-Tool software. In the last stage, simulations results will be shown for improvement and accuracy of technical provision.
Abstract: This study presents an investigation of
electrochemical variables and an application of the optimal
parameters in operating a continuous upflow electrocoagulation
reactor in removing dye. Direct red 23, which is azo-based, was used
as a representative of direct dyes. First, a batch mode was employed
to optimize the design parameters: electrode type, electrode distance,
current density and electrocoagulation time. The optimal parameters
were found to be iron anode, distance between electrodes of 8 mm
and current density of 30 A·m-2 with contact time of 5 min. The
performance of the continuous upflow reactor with these parameters
was satisfactory, with >95% color removal and energy consumption
in the order of 0.6-0.7 kWh·m-3.
Abstract: Electric impedance imaging is a method of
reconstructing spatial distribution of electrical conductivity inside a
subject. In this paper, a new method of electrical impedance imaging
using eddy current is proposed. The eddy current distribution in the
body depends on the conductivity distribution and the magnetic field
pattern. By changing the position of magnetic core, a set of voltage
differences is measured with a pair of electrodes. This set of voltage
differences is used in image reconstruction of conductivity
distribution. The least square error minimization method is used as a
reconstruction algorithm. The back projection algorithm is used to
get two dimensional images. Based on this principle, a measurement
system is developed and some model experiments were performed
with a saline filled phantom. The shape of each model in the
reconstructed image is similar to the corresponding model,
respectively. From the results of these experiments, it is confirmed
that the proposed method is applicable in the realization of electrical
imaging.
Abstract: In situ observation of absorption spectral change of
heptil viologen cation radical (HV+.) was performed by slab optical
waveguide (SOWG) spectroscopy utilizing indium-tin-oxide (ITO)
electrodes. Synchronizing with electrochemical techniques, we
observed the adsorption process of HV+.on the ITO electrode. In this
study, we carried out the ITO-SOWG observations using KBr aqueous
solution containing different concentration of HV to investigate the
concentration dependent spectral change. A few specific absorption
bands, which indicated HV+.existed as both monomer and dimer on
ITO electrode surface with a monolayer or a few layers deposition,
were observed in UV-visible region. The change in the peak position
of the absorption spectra from adsorption species of HV+. were
correlated with the concentration of HV as well as the electrode
potential.
Abstract: This work attempts to improve the permselectivity of poly-ortho-phenylenediamine (PPD) coating for glutamate biosensor applications on Pt microelectrode, using constant potential amperometry and cyclic voltammetry. Percentage permeability of the modified PPD microelectrode was carried out towards hydrogen peroxide (H2O2) and ascorbic acid (AA) whereas permselectivity represents the percentage interference by AA in H2O2 detection. The 50-μm diameter Pt disk microelectrode showed a good permeability value toward H2O2 (95%) and selectivity against AA (0.01%) compared to other sizes of electrode studied here. The electrode was further modified with glutamate oxidase (GluOx) that was immobilized and cross linked with glutaraldehyde (GA, 0.125%), resulting in Pt/PPD/GluOx-GA electrode design. The maximum current density Jmax and apparent Michaelis constant, KM, obtained on Pt/PPD/GluOx-GA electrodes were 48 μA cm-2 and 50 μM, respectively. The linear region slope (LRS) was 0.96 μA cm-2 mM-1. The detection limit (LOD) for glutamate was 3.0 ± 0.6 μM. This study shows a promising glutamate microbiosensor for brain glutamate detection.
Abstract: Planar systems of electrodes arranged on both sides of dielectric piezoelectric layer are applied in numerous transducers. They are capable of electronic beam-steering of generated wave both in azimuth and elevation. The wave-beam control is achieved by addressable driving of two-dimensional transducer through proper voltage supply of electrodes on opposite surfaces of the layer. In this paper a semi-analytical method of analysis of the considered transducer is proposed, which is a generalization of the well-known BIS-expansion method. It was earlier exploited with great success in the theory of interdigital transducers of surface acoustic waves, theory of elastic wave scattering by cracks and certain advanced electrostatic problems. The corresponding nontrivial electrostatic problem is formulated and solved numerically.
Abstract: This paper presents development of an ignition system using spark electrodes for application in a research explosion vessel.
A single spark is aimed to be discharged with quantifiable ignition energy. The spark electrode system would enable study of flame
propagation, ignitability of fuel-air mixtures and other fundamental characteristics of flames. The principle of the capacitive spark circuit
of ASTM is studied to charge an appropriate capacitance connected across the spark gap through a large resistor by a high voltage from
the source of power supply until the initiation of spark. Different spark energies could be obtained mainly by varying the value of the
capacitance and the supply current. The spark sizes produced are found to be affected by the spark gap, electrode size, input voltage
and capacitance value.
Abstract: Hydrogen is considered to be the most promising
candidate as a future energy carrier. One of the most used
technologies for the electrolytic hydrogen production is alkaline
water electrolysis. However, due to the high energy requirements, the
cost of hydrogen produced in such a way is high. In continuous
search to improve this process using advanced electrocatalytic
materials for the hydrogen evolution reaction (HER), Ni type Raney
and macro-porous Ni-Co electrodes were prepared on AISI 304
stainless steel substrates by electrodeposition. The developed
electrodes were characterized by SEM and confocal laser scanning
microscopy. HER on these electrodes was evaluated in 30 wt.% KOH
solution by means of hydrogen discharge curves and galvanostatic
tests. Results show that the developed electrodes present a most
efficient behaviour for HER when comparing with the smooth Ni
cathode. It has been reported a reduction in the energy consumption
of the electrolysis cell of about 25% by using the developed coatings
as cathodes.
Abstract: Electrolytic dissolution characteristics of UO2 and
SIMFUEL electrodes were studied at several potentials in carbonate
solutions of a high concentration at several pHs. The electrolytic
uranium dissolution was much affected by a corrosion product of
UO2CO3 generated at the electrode during the dissolution in carbonate
solution. The corrosion product distorted the voltammogram at UO2
and SIMFUEL electrodes in the potential region of oxygen evolution
and increased the overpotential of oxygen evolution at the electrode.
The effective dissolution in a carbonate solution could be obtained at
an applied potential such as +4 V (vs SSE) or more which had an
overpotential of oxygen evolution high enough to rupture the
corrosion product on the electrode surface.
Abstract: This paper investigates the influence of various
parameters on the behaviour of water droplets on polymeric surfaces
under high electric fields. An inclined plane test was carried out to
understand the droplet behaviour in strong electric field. Parameters
such as water droplet conductivity, droplet volume, polymeric
surface roughness and droplet positioning with respect to the
electrodes were studied. The flashover voltage is affected by all
aforementioned parameters. The droplet positioning is in some cases
more vital than the droplet volume. Surface damages were analysed
using Scanning Electron Microscopy (SEM) studies and by Energy
dispersive X-ray Analysis (EDAX). It is observes that magnitude of
discharge have direct influence on amount of surface da
Abstract: This paper presents an exact solution and a finite element method (FEM) for a Piezoceramic Rod under static load. The cylindrical rod is made from polarized ceramics (piezoceramics) with axial poling. The lateral surface of the rod is traction-free and is unelectroded. The two end faces are under a uniform normal traction. Electrically, the two end faces are electroded with a circuit between the electrodes, which can be switched on or off. Two cases of open and shorted electrodes (short circuit and open circuit) will be considered. Finally, a finite element model will be used to compare the results with an exact solution. The study uses ABAQUS (v.6.7) software to derive the finite element model of the ceramic rod.
Abstract: The objective of this paper is to characterize the spontaneous Electroencephalogram (EEG) signals of four different motor imagery tasks and to show hereby a possible solution for the present binary communication between the brain and a machine ora Brain-Computer Interface (BCI). The processing technique used in this paper was the fractal analysis evaluated by the Critical Exponent Method (CEM). The EEG signal was registered in 5 healthy subjects,sampling 15 measuring channels at 1024 Hz.Each channel was preprocessed by the Laplacian space ltering so as to reduce the space blur and therefore increase the spaceresolution. The EEG of each channel was segmented and its Fractaldimension (FD) calculated. The FD was evaluated in the time interval corresponding to the motor imagery and averaged out for all the subjects (each channel). In order to characterize the FD distribution,the linear regression curves of FD over the electrodes position were applied. The differences FD between the proposed mental tasks are quantied and evaluated for each experimental subject. The obtained results of the proposed method are a substantial fractal dimension in the EEG signal of motor imagery tasks and can be considerably utilized as the multiple-states BCI applications.
Abstract: Effect of temperature and light was investigated on a
thin film of organic semiconductor formyl-TIPPCu(II) deposited on a
glass substrate with preliminary evaporated gold electrodes. The
electrical capacitance and resistance of the fabricated device were
evaluated under the effect of temperature and light. The relative
capacitance of the fabricated sensor increased by 4.3 times by rising
temperature from 27 to 1870C, while under illumination up to 25000
lx, the capacitance of the Au/formyl-TIPPCu(II)/Au photo capacitive
sensor increased continuously by 13.2 times as compared to dark
conditions.
Abstract: We demonstrate a nonfaradaic electrochemical impedance spectroscopy measurement of biochemically modified gold plated electrodes using a two-electrode system. The absence of any redox indicator in the impedance measurements provide more precise and accurate characterization of the measured bioanalyte at molecular resolution. An equivalent electrical circuit of the electrodeelectrolyte interface was deduced from the observed impedance data of saline solution at low and high concentrations. The detection of biomolecular interactions was fundamentally correlated to electrical double-layer variation at modified interface. The investigations were done using 20mer deoxyribonucleic acid (DNA) strands without any label. Surface modification was performed by creating mixed monolayer of the thiol-modified single-stranded DNA and a spacer thiol (mercaptohexanol) by a two-step self-assembly method. The results clearly distinguish between the noncomplementary and complementary hybridization of DNA, at low frequency region below several hundreds Hertz.
Abstract: Nuclear matrix protein 22 (NMP22) is a FDA approved
biomarker for bladder cancer. The objective of this study is to develop
a simple NMP22 immumosensor (NMP22-IMS) for accurate
measurement of NMP22. The NMP22-IMS was constructed with
NMP22 antibody immobilized on screen-printed carbon electrodes.
The construction procedures and antibody immobilization are simple.
Results showed that the NMP22-IMS has an excellent (r2³0.95)
response range (20 – 100 ng/mL). In conclusion, a simple and reliable
NMP22-IMS was developed, capable of precisely determining urine
NMP22 level.
Abstract: We succeeded to produce a high performance and flexible graphene/Manganese dioxide (G/MnO2) electrode coated on flexible polyethylene terephthalate (PET) substrate. The graphene film is initially synthesized by drop-casting the graphene oxide (GO) solution on the PET substrate, followed by simultaneous reduction and patterning of the dried film using carbon dioxide (CO2) laser beam with power of 1.8 W. Potentiostatic Anodic Deposition method was used to deposit thin film of MnO2 with different loading mass 10 – 50 and 100 μg.cm-2 on the pre-prepared graphene film. The electrodes were fully characterized in terms of structure, morphology, and electrochemical performance. A maximum specific capacitance of 973 F.g-1 was attributed when depositing 50μg.cm-2 MnO2 on the laser reduced graphene oxide rGO (or G/50MnO2) and over 92% of its initial capacitance was retained after 1000 cycles. The good electrochemical performance and long-term cycling stability make our proposed approach a promising candidate in the supercapacitor applications.
Abstract: In this paper we introduce a novel method for
the characterization of synchronziation and coupling effects
in multivariate time series that can be used for the analysis
of EEG or ECoG signals recorded during epileptic seizures.
The method allows to visualize the spatio-temporal evolution
of synchronization and coupling effects that are characteristic
for epileptic seizures. Similar to other methods proposed for
this purpose our method is based on a regression analysis.
However, a more general definition of the regression together
with an effective channel selection procedure allows to use the
method even for time series that are highly correlated, which
is commonly the case in EEG/ECoG recordings with large
numbers of electrodes. The method was experimentally tested
on ECoG recordings of epileptic seizures from patients with
temporal lobe epilepsies. A comparision with the results from
a independent visual inspection by clinical experts showed
an excellent agreement with the patterns obtained with the
proposed method.
Abstract: Electrochemical-oxidation of Reactive Black-5 (RB- 5) was conducted for degradation using DSA type Ti/RuO2-SnO2- Sb2O5 electrode. In the study, for electro-oxidation, electrode was indigenously fabricated in laboratory using titanium as substrate. This substrate was coated using different metal oxides RuO2, Sb2O5 and SnO2 by thermal decomposition method. Laboratory scale batch reactor was used for degradation and decolorization studies at pH 2, 7 and 11. Current density (50mA/cm2) and distance between electrodes (8mm) were kept constant for all experiments. Under identical conditions, removal of color, COD and TOC at initial pH 2 was 99.40%, 55% and 37% respectively for initial concentration of 100 mg/L RB-5. Surface morphology and composition of the fabricated electrode coatings were characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) respectively. Coating microstructure was analyzed by X-ray diffraction (XRD). Results of this study further revealed that almost 90% of oxidation occurred within 5-10 minutes.
Abstract: The aim of this study was to remove the two principal
noises which disturb the surface electromyography signal
(Diaphragm). These signals are the electrocardiogram ECG artefact
and the power line interference artefact. The algorithm proposed
focuses on a new Lean Mean Square (LMS) Widrow adaptive
structure. These structures require a reference signal that is correlated
with the noise contaminating the signal. The noise references are
then extracted : first with a noise reference mathematically
constructed using two different cosine functions; 50Hz (the
fundamental) function and 150Hz (the first harmonic) function for
the power line interference and second with a matching pursuit
technique combined to an LMS structure for the ECG artefact
estimation. The two removal procedures are attained without the use
of supplementary electrodes. These techniques of filtering are
validated on real records of surface diaphragm electromyography
signal. The performance of the proposed methods was compared with
already conducted research results.
Abstract: Carbon nanotubes (CNTs) with their high mechanical,
electrical, thermal and chemical properties are regarded as promising
materials for many different potential applications. Having unique
properties they can be used in a wide range of fields such as
electronic devices, electrodes, drug delivery systems, hydrogen
storage, textile etc. Catalytic chemical vapor deposition (CCVD) is a
common method for CNT production especially for mass production.
Catalysts impregnated on a suitable substrate are important for
production with chemical vapor deposition (CVD) method. Iron
catalyst and MgO substrate is one of most common catalyst-substrate
combination used for CNT. In this study, CNTs were produced by
CCVD of acetylene (C2H2) on magnesium oxide (MgO) powder
substrate impregnated by iron nitrate (Fe(NO3)3•9H2O) solution. The
CNT synthesis conditions were as follows: at synthesis temperatures
of 500 and 800°C multiwall and single wall CNTs were produced
respectively. Iron (Fe) catalysts were prepared by with Fe:MgO ratio
of 1:100, 5:100 and 10:100. The duration of syntheses were 30 and
60 minutes for all temperatures and catalyst percentages. The
synthesized materials were characterized by thermal gravimetric
analysis (TGA), transmission electron microscopy (TEM) and Raman
spectroscopy.