Parallel Metal Plates Research Articles

PERUBAHAN SUDUT POLARISASI ALAMI DAN ELEKTROOPTIS MINYAK SAWIT YANG DICAMPUR BERBAGAI MINYAK HEWANI

Palm oil-based cooking oil is the most widely used cooking oil. Palm oil circulating in the market is often mixed with animal oil by culinary entrepreneurs with a view to produce a more tasty taste so it needs to be examined purity. Research on the content of saturated fatty acids using gas chromatography mass spectrophotometer (GCMS) requires quite expensive cost so that an alternative method is needed to determine the quality of cooking oil; especially its purity is by using polarization both naturally and by electrooptic method. This research uses incandescent lamp as light source. Samples flanked by parallel metal plates are placed between polarizers and analyzers. Samples of a mixture of palm oil with each animal oil (chicken oil, pork oil, cow oil). The samples of each oil are tested byu using natural polarization (active polarization) and electro-polarization polarization (impact polarization). The results showed that the polarization angle change in the oil of the mixture was greater than that of pure palm oil with the greatest angular change produced by a mixture of palm oil and cow oil (1.5 for natural polarization and 3 for electro-polarization). This result was in accordance with the result of the titration test shows that mixed oils have free fatty acids and PV peroxide numbers higher than pure palm oil. The cow's oil mix is the greatest change compared to pigs and chickens. This result shows that cow's oil has the highest saturated fatty acid content. Electrooptical polarization angle larger than natural polarization. This is due to the interaction of the electric field of the light source with the electric field of the molecule induced by the electric field of the power supply. The polarization method successfully distinguishes the type of pure and mixed cooking oil.

Two discharge modes of a repetitive nanosecond pulsed helium glow discharge under sub-atmospheric pressure in the repetition frequency range of 20 to 600 kHz

Two discharge modes, α and γ, of a repetitive nanosecond pulsed helium glow discharge at a gas pressure of 10 kPa in the repetition frequency range from 20 to 600 kHz are reported for the first time. The pulsed glow discharge is produced in a pair of parallel plate metal electrodes without insertion of dielectrics. The α mode discharge is volumetrically produced in the electrode gap at a low-repetition frequency, whereas the γ mode discharge is localized at the cathode surface at a high-repetition frequency. At high-repetition frequency, the time interval between voltage pulses is shorter than the lifetime of the afterglow produced by the preceding discharge. Then, the γ mode discharge is maintained by a large number of secondary electrons emitted from the cathode exposed to high-density ions and metastable helium atoms in the afterglow. In the α mode discharge with a low-repetition frequency operation, primary electrons due to gas ionization dominate the ionization process. Thus, a large discharge voltage is needed for the excitation of the α mode discharge. It is established that the bifurcation of α-γ discharge mode, accompanied by a decrease in the discharge voltage, occurs at the high-repetition frequency of ∼120 kHz.

Amplitude and Wavelength Measurement of Sound Waves in Free Space using a Sound Wave Phase Meter

We developed a sound wave phase meter (SWPM) and measured the amplitude and wavelength of sound waves in free space. The SWPM consists of two parallel metal plates, where the front plate was operated as a diaphragm. An aluminum perforated plate was additionally installed in front of the diaphragm, and the same signal as that applied to the sound source was applied to the perforated plate. The SWPM measures both the sound wave signal due to the diaphragm vibration and the induction signal due to the electric field of the aluminum perforated plate. Therefore, the two measurement signals interfere with each other due to the phase difference according to the distance between the sound source and the SWPM, and the amplitude of the composite signal that is output as a result is periodically changed. We obtained the wavelength of the sound wave from this periodic amplitude change measured in the free space and compared it with the theoretically calculated values.

Handwritten Oxide Electronics on Paper

The present work reports on the handwriting of electronic circuits on paper based on the deposition of an inorganic oxide semiconductor, exploiting the pen‐on‐paper (PoP) approach. The method relies on the use of a parallel metal plate pen, well known from calligraphy applications, which permits controlled deposition of a continuous zinc oxide (ZnO) dual‐phase layer on conventional printing paper. The hand‐drawn ZnO film exhibits a continuous and uniform surface with a thickness of roughly 1.5 µm, allowing the application as active layer for UV sensors and field effect transistors on paper. Photocurrent generated from the UV radiation reaches values up to 3.4 mA cm−2 with switching times on the order of few seconds. The final written paper transistors, where paper plays simultaneously the role of substrate and dielectric, reaches On/Off current ratios (IOn/IOff) of about two orders of magnitude and field effect mobility close to 5 × 10−3 cm2 V−1 s−1. As a final proof‐of‐concept a common source amplifier showing clear inverting characteristics is fabricated using a PoP written driving ZnO‐based transistor and a pencil‐drawn track as the load resistance.

Low‐cost fabrication of polymer substrate‐based piezoelectric microgenerator with PPE, IDE and ME

Piezoelectric microgenerator is an incredible method which makes a self-powered wireless sensor node. It is a process of converting ambient energy into electrical energy. Flexible microgenerator goes well with many natural curved, rough and arbitrary surfaces such as human bodies, organisms, clothes and structure surfaces. Zinc oxide and polymer have been used as piezoelectric material and substrate, respectively, for biocompatible device. The harmonic analysis was carried out using finite element method (FEM) tool to examine the effect of the electrodes on the output voltage. Microgenerators with different electrodes were fabricated and examined their performance. Traditional parallel plate metal electrodes (PPEs) are prone to cracks and internal defects on bending or stretching, thus mesh electrodes (MEs) has been proposed. Copper MEs based microgenerator has performed at par. Open-circuit electric potential of 2.8 VPEAK, 435 mVRMS for ME against electric potential of 2.3 VPEAK, 430 mVRMS and 0.9 V, 340 VPEAK, 40 mVRMS for interdigitated electrodes (IDEs) and PPE, respectively, were recorded. Design, fabrication, electrical characterisation and comparative evaluation of microgenerator with three different electrodes are presented.

Инженерный расчет и оптимизация параметров полуэкранированного диэлектрического волновода в неизлучающем режиме

The parameters of half-shielded dielectric waveguides optimized in terms of their frequency bandwidth are investigated as a supplement to the procedure for designing waveguide transitions. The half-shielded dielectric waveguide is a rectangular dielectric rod placed between two parallel metal plates. Such a waveguide is in its own way a "hybrid" of open and closed transmission lines. It simultaneously has the properties of both the types of transmission lines; these properties may exhibit themselves to a greater or lesser extent depending on the design. Under certain conditions, a so called non-radiating effect is observed in this waveguide, a phenomenon consisting in that the electromagnetic energy is held in the dielectric rod when it is bent or deformed (provided, however, that the plane symmetry is retained). The ratio of the distance between the metal plates to the dielectric rod width is called the rod form-factor. For a non-radiating mode, there exists a certain optimal form-factor, at which the maximum frequency bandwidth is reached. The frequency bandwidth as a function of the waveguide form-factor is presented. Dependences characterizing the optimum form factor (according to the largest frequency bandwidth criterion) versus the medium parameters are investigated, and empirical formulas for evaluating them are proposed. An engineering method is proposed for calculating the physical parameters of non-radiating dielectric waveguides, which is one of the stages in calculating waveguide transitions. Empirical formulas for estimating the dependence of optimal form-factor on the parameters of medium are investigated and proposed. Dependences of the optimal form-factor and the frequency bandwidth coefficient on the ratio of dielectric constants of the waveguide rod and external medium are presented. An engineering method for calculating the physical parameters of non-radiating half-shielded dielectric waveguides is suggested. It is found that the non-radiating dielectric waveguide's frequency ratio lies in the range from 24 to 30%. It is shown that materials with a dielectric constant higher than 5 are best suited for achieving the largest frequency bandwidth. A formula for approximating the dependence of the optimal form-factor on the rod dielectric constant in the range from 1.5 to 30 is proposed.

The Field-Programmable Microwave Substrate

A novel low-loss programmable microwave waveguide is demonstrated. The waveguide is developed for applications in field-programmable microwave circuits with similar levels of programmability as that seen in field-programmable gate arrays. The waveguide is realized with a field-programmable microwave substrate (FPMS). The substrate consists of small unit cells that can be individually reconfigured to have a range of positive dielectric constants or a negative dielectric constant. The substrate is contained in a metal parallel plate structure. Programming a positive material sandwiched between two negative material sidewalls results in a waveguide that behaves in a way that is described by the slab waveguide equations. Miniaturization and increased density of unit cells can result in lower loss and better performance. Two implementations of the FPMS are presented. One implementation is on FR4 using all industry standard processes and components. The other implementation uses low-temperature cofired ceramic and custom designed CMOS chips. The FR4 implementation is used to demonstrate programmable waveguides, amplifiers, and oscillators from 0.9 to 3 GHz. The LTCC implementation is used to demonstrate miniaturization of the FPMS. The proposed FPMS concept promises a new era of programmable microwave circuit design for cognitive radio, the Internet of things, and self-healing/adaptive systems.

Numerical analysis of terahertz surface plasmon polaritons propagating in a parallel plate configuration

In this paper, we present numerical analysis of terahertz (THz) surface plasmon polaritons propagating in a parallel plate configuration. A planar metal surface has the ability to support loosely bound surface waves, called Zenneck waves at terahertz frequencies. Two parallel metal plates separated by a narrow vacuum region can lead to the highly confined terahertz surface plasmon modes at specific frequencies. The frequency of the terahertz mode can be changed with a change in the gap between the plates. Further, we observed that the carrier concentration of plates strongly effect the frequency of the terahertz mode as well as its properties. We have examined in detail the dispersion properties of the terahertz surface plasmons supported by the parallel plate configuration with a varying gap width as well as carrier density of the plates.

A highly accurate and efficient algorithm for electrostatic interactions of charged particles confined by parallel metallic plates.

We present an accurate and efficient algorithm to calculate the electrostatic interaction of charged point particles with partially periodic boundary conditions that are confined along the non-periodic direction by two parallel metallic plates. The method preserves the original boundary conditions, leading to an exact solution of the problem. In addition, the scaling complexity is quasilinear O(Nln(N)), where N is the number of particles in the simulation box. Based on the superposition principle in electrostatics, the problem is split into two electrostatic problems where each can be calculated by the appropriate Poisson solver. The method is applied to NaCl ultra-thin films where its dielectric response with respect to an external bias voltage is investigated. Furthermore, the total charge induced on the metallic boundaries can be calculated to an arbitrary precision.

High‐gain wideband SIW offset parabolic antenna

ABSTRACTA substrate integrated waveguide (SIW) offset parabolic antenna is proposed in this letter. The antenna consists of four main parts: a feeder with a horn radiator, a parabolic reflector, parallel plate metal blocks, and a dielectric load. The configuration of the horn and parabolic reflector is based on the parabolic reflector principle. The parallel plate metal blocks and the dielectric load improve the impedance matching and radiation performance of the antenna. Measured results show that the antenna is very well matched in the V‐band and the gain of the antenna in end‐fire direction varies from 13.2 dBi to 16.8 dBi. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2888–2892, 2016

Interfacial Mechanical Performance of Composite Honeycomb Sandwich Panels for Aerospace Applications

A simple and cost-effective manufacturing process was employed to prepare composite honeycomb sandwich panels for aerospace applications. Carbon fiber–epoxy matrix composite facesheets were first prepared by vacuum-assisted resin transfer molding, and later these facesheets were bonded with the Nomex\(^{\textregistered }\) honeycomb core by compression technique wherein the whole sandwich assembly containing facesheets, epoxy- based adhesive film and honeycomb core was clamped between two parallel metallic plates followed by curing in oven. Different curing temperatures, i.e., 100, 110, 120 and 130\({^{\circ }}\)C, and curing times, i.e., 2 and 3 h, were employed to optimize the curing parameters of the adhesive film to join CF–epoxy facesheets with the honeycomb core. The optimization of the curing parameters was related to the maximum load-bearing capability of composite honeycomb sandwich panels under three-point bend test and associated mechanical properties. It was shown that the composite honeycomb sandwich panels cured at 130\({^{\circ }}\)C for 3 h demonstrated maximum mechanical performance.

Environmentally friendly power generator based on moving liquid dielectric and double layer effect.

An electrostatic power generator converts mechanical energy to electrical energy by utilising the principle of variable capacitance. This change in capacitance is usually achieved by varying the gap or overlap between two parallel metallic plates. This paper proposes a novel electrostatic micro power generator where the change in capacitance is achieved by the movement of an aqueous solution of NaCl. A significant change in capacitance is achieved due to the higher than air dielectric constant of water and the Helmholtz double layer capacitor formed by ion separation at the electrode interfaces. The proposed device has significant advantages over traditional electrostatic devices which include low bias voltage and low mechanical frequency of operation. This is critical if the proposed device is to have utility in harvesting power from the environment. A figure of merit exceeding 10000(108μW)/(mm2HzV2) which is two orders of magnitude greater than previous devices, is demonstrated for a prototype operating at a bias voltage of 1.2 V and a droplet frequency of 6 Hz. Concepts are presented for large scale power harvesting.

A high current pulsed power generator CQ-3-MMAF with co-axial cable transmitting energy for material dynamics experiments.

A high current pulsed power generator CQ-3-MMAF (Multi-Modules Assembly Facility, MMAF) was developed for material dynamics experiments under ramp wave and shock loadings at the Institute of Fluid Physics (IFP), which can deliver 3 MA peak current to a strip-line load. The rise time of the current is 470 ns (10%-90%). Different from the previous CQ-4 at IFP, the CQ-3-MMAF energy is transmitted by hundreds of co-axial high voltage cables with a low impedance of 18.6 mΩ and low loss, and then hundreds of cables are reduced and converted to tens of cables into a vacuum chamber by a cable connector, and connected with a pair of parallel metallic plates insulated by Kapton films. It is composed of 32 capacitor and switch modules in parallel. The electrical parameters in short circuit are with a capacitance of 19.2 μF, an inductance of 11.7 nH, a resistance of 4.3 mΩ, and working charging voltage of 60 kV-90 kV. It can be run safely and stable when charged from 60 kV to 90 kV. The vacuum of loading chamber can be up to 10(-2) Pa, and the current waveforms can be shaped by discharging in time sequences of four groups of capacitor and switch modules. CQ-3-MMAF is an adaptive machine with lower maintenance because of its modularization design. The COMSOL Multi-physics® code is used to optimize the structure of some key components and calculate their structural inductance for designs, such as gas switches and cable connectors. Some ramp wave loading experiments were conducted to check and examine the performances of CQ-3-MMAF. Two copper flyer plates were accelerated to about 3.5 km/s in one shot when the working voltage was charged to 70 kV. The velocity histories agree very well. The dynamic experiments of some polymer bonded explosives and phase transition of tin under ramp wave loadings were also conducted. The experimental data show that CQ-3-MMAF can be used to do material dynamics experiments in high rate and low cost shots. Based on this design concept, the peak current of new generators can be increased to 5-6 MA and about 100 GPa ramp stress can be produced on the metallic samples for high pressure physics, and a conceptual design of CQ-5-MMAF was given.

Particle-in-cell simulation of multipactor discharge on a dielectric in a parallel-plate waveguide

An original 2D3V (two-dimensional in coordinate space and three-dimensional in velocity space) particle-in-cell code has been developed for simulation of multipactor discharge on a dielectric in a parallelplate metal waveguide with allowance for secondary electron emission (SEE) from the dielectric surface and waveguide walls, finite temperature of secondary electrons, electron space charge, and elastic and inelastic scattering of electrons from the dielectric and metal surfaces. The code allows one to simulate all stages of the multipactor discharge, from the onset of the electron avalanche to saturation. It is shown that the threshold for the excitation of a single-surface multipactor on a dielectric placed in a low-profile waveguide with absorbing walls increases as compared to that in the case of an unbounded dielectric surface due to escape of electrons onto the waveguide walls. It is found that, depending on the microwave field amplitude and the SEE characteristics of the waveguide walls, the multipactor may operate in two modes. In the first mode, which takes place at relatively low microwave amplitudes, a single-surface multipactor develops only on the dielectric, the surface of which acquires a positively potential with respect to the waveguide walls. In the second mode, which occurs at sufficiently high microwave intensities, a single-surface multipactor on the dielectric and a two-surface multipactor between the waveguide walls operate simultaneously. In this case, both the dielectric surface and the interwall space acquire a negative potential. It is shown that electron scattering from the dielectric surface and waveguide walls results in the appearance of high-energy tails in the electron distribution function.

Effects of Asymmetric Dynamic Loading on Intervertebral Disc – towards a Scoliosis Mimicking Organ Culture Model

Introduction The etiology of spinal deformity in idiopathic scoliosis is unclear to date. One of the suspected influences is the asymmetric loading condition involved in the disorder. The aim of this project is to test the hypothesis that asymmetric dynamic loading influences the morphological and biological characteristics of the intervertebral discs in scoliosis. The study is performed with organ cultured discs by using a custom-designed asymmetrical loading device. Material and Methods Bovine caudal discs (6–10 months) were used in current study. For symmetric dynamic loading (Parallel), discs were placed in custom-designed chambers, and compressed by parallel metal plates in a Bose mechanical testing device. For asymmetric dynamic loading (Wedge), a 10° wedge was placed underneath the discs to mimic the load bearing condition of discs in scoliotic patients. The discs were submitted to 2 different load regimes: (1) 1 hour dynamic loading (0.02–0.4 MPa, 1Hz) and 23 hours free swelling culture for 7 days; (2) 1 hour dynamic loading (0.02–0.4 MPa, 1Hz) and 23 hours static loading (0.2 MPa) for 7 days. Disc heights were measured with caliper before and after each loading. After 7 days of culture, gene expression levels of aggrecan (ACAN), type I and II collagen (COL1 and COL2), IL1, IL6, and MMP1 in the annulus fibrosus was analyzed by real-time PCR. Genes that have been found dysregulated in human scoliotic discs compared with healthy controls were also measured in the organ cultured discs, including MMP13, type X collagen (COL10), CXCR4, BMP3, S100A12, and S100A8 ( n = 8). Results Disc height showed a constant drop in load regime 2, while a temporary decrease after 1h dynamic loading followed by free swelling recovery was noted in load regime 1. After 7th dynamic loading, the change in shape was greater in load regime 2 (disc height ratio wedged to non-wedged side of 0.81), than that in load regime 1 (height ratio of 0.87, p < 0.05). Under load regime 2, MMP13 gene expression level increased 6.1-fold in Wedge disc compared with Parallel disc, while gene expression levels of COL10, CXCR4, BMP3, S100A12, and S100A8 were not affected. Gene expression levels of ACAN, COL1 and COL2 under load regime 1 were significantly higher compared with load regime 2. Moreover, discs under load regime 2 showed a trend in higher IL1, IL6, and MMP1 gene expression compared with regime 1. Conclusion Diurnal dynamic loading and free swelling recovery could maintain the gene expression of organ cultured discs at their physiological level. Diurnal dynamic loading followed by static loading mimicked a degenerative condition, as indicated by lower anabolic and higher catabolic gene expression. These results suggest that recovery of disc height and morphology after dynamic load may help to prevent degeneration of discs under constant loading. Asymmetric dynamic and static loading regime induces an increase in MMP13 gene expression compared with symmetric loading, which was also observed in a human scoliosis sample dataset. These results indicate that short-term asymmetric loading may be used to mimic early changes associated with the onset of scoliosis. Acknowledgment This study is supported by AOSpine International.

Radiative heat conductances between dielectric and metallic parallel plates with nanoscale gaps.

Recent experiments have demonstrated that radiative heat transfer between objects separated by nanometre-scale gaps considerably exceeds the predictions of far-field radiation theories. Exploiting this near-field enhancement is of great interest for emerging technologies such as near-field thermophotovoltaics and nano-lithography because of the expected increases in efficiency, power conversion or resolution in these applications. Past measurements, however, were performed using tip-plate or sphere-plate configurations and failed to realize the orders of magnitude increases in radiative heat currents predicted from near-field radiative heat transfer theory. Here, we report 100- to 1,000-fold enhancements (at room temperature) in the radiative conductance between parallel-planar surfaces at gap sizes below 100 nm, in agreement with the predictions of near-field theories. Our measurements were performed in vacuum gaps between prototypical materials (SiO2-SiO2, Au-Au, SiO2-Au and Au-Si) using two microdevices and a custom-built nanopositioning platform, which allows precise control over a broad range of gap sizes (from <100 nm to 10 μm). Our experimental set-up will enable systematic studies of a variety of near-field-based thermal phenomena, with important implications for thermophotovoltaic applications, that have been predicted but have defied experimental verification.

Calculation of Magnetization and Permeability Tensor of a Partially Magnetized Cylindrical Ferrite Resonator

A accurate method of calculating a magnetization and permeability tensor of ferrites is proposed in this paper. We introduce a cylindrical ferrite resonator that is located between parallel metal plates. We theoretically derive exact eigenvalue equations for the mode-splitting phenomenon of the HE 111 mode. We also show that the mode-splitting behavior depends on a single magnetization value of the ferrite. The magnetization and permeability tensor components are computed from the measured resonant frequencies of the resonator. We present an analysis of cylindrical ferrite resonator and its experimental results.

25-Gb/s broadband silicon modulator with 0.31-V·cm VπL based on forward-biased PIN diodes embedded with passive equalizer.

We investigated the broadband operations of a silicon Mach-Zehnder modulator (MZM) based on a forward-biased-PIN diode. The phase shifter was integrated with a passive-circuit equalizer to compensate for the narrowband characteristics of the diodes, which consists of a simple resistance of doped silicon and a parallel-plate metal capacitance. The device structure was simple and fabricated using standard CMOS processes. The measured results for a 50-Ω driver indicated there was a small VπL of 0.31 V·cm and a flat frequency response for a 3-dB bandwidth (f(3dB)) of 17 GHz, which agree well with the designed values. A 25-Gb/s large-signal operation was obtained using binary signals without pre-emphasis. The modulator showed a linear modulation property to the applied voltage, due to the metal capacitance of the equalizer.

Measurement method of charge densities at ground level under high‐voltage direct current conductor

Ions generated by corona discharge of high-voltage direct current (HVDC) transmission lines exist in the space between conductors and the ground. Electric field strength, ion current density, and space charge density are significant electromagnetic environment parameters of HVDC transmission lines. To measure the charge densities at ground level under the HVDC power lines, an aspirator-type charge meter is designed and utilised. The charge meter is calibrated in the ionised field generated by parallel metal mesh and plate. Charge densities on the ground under the unipolar HVDC conductor are measured by the calibrated devices in the laboratory. Experimental results show that reasonable agreement between measured data by the devices and the ones by field mills and ion current plates could be obtained, which establishes a foundation to research the charge characteristics of ions near the ground.

Casimir effects are not an experimental demonstration that free vacuum gravitates: connections to the Cosmological Constant Problem

We discuss a concrete model of a Casimir cavity, with plane parallel metallic plates kept in mechanical equilibrium by a spring and placed in a weak gravitational field. We show that simple basic physics implies that the plates cannot be idealized as massless and therefore the effect of the vacuum is inextricably connected with the interaction with the matter of the plates. In Casimir cavities, it is a vacuum bound by matter which is at work. Therefore, the existence of the Casimir force does not imply that free vacuum gravitates and contributes to the cosmological constant.