Abstract: This paper investigates experimental studies on
vibration suppression for a cantilever beam using an
Electro-Rheological (ER) sandwich shock absorber. ER fluid (ERF) is a
class of smart materials that can undergo significant reversible changes
immediately in its rheological and mechanical properties under the
influence of an applied electric field. Firstly, an ER sandwich beam is
fabricated by inserting a starch-based ERF into a hollow composite
beam. At the same time, experimental investigations are focused on the
frequency response of the ERF sandwich beam. Second, the ERF
sandwich beam is attached to a cantilever beam to become as a shock
absorber. Finally, a fuzzy semi-active vibration control is designed to
suppress the vibration of the cantilever beam via the ERF sandwich
shock absorber. To check the consistency of the proposed fuzzy
controller, the real-time implementation validated the performance of
the controller.
Abstract: A device analysis of the photoconductive
semiconductor switch is carried out to investigate distribution of
electric field and carrier concentrations as well as the current density
distribution. The operation of this device was then investigated as a
switch operating in X band. It is shown that despite the presence of
symmetry geometry, switch current density of the on-state steady
state mode is distributed asymmetrically throughout the device.
Abstract: In this paper, for the first time, a two-dimensional
(2D) analytical drain current model for sub-100 nm multi-layered
gate material engineered trapezoidal recessed channel (MLGMETRC)
MOSFET: a novel design is presented and investigated using
ATLAS and DEVEDIT device simulators, to mitigate the large gate
leakages and increased standby power consumption that arise due to
continued scaling of SiO2-based gate dielectrics. The twodimensional
(2D) analytical model based on solution of Poisson-s
equation in cylindrical coordinates, utilizing the cylindrical
approximation, has been developed which evaluate the surface
potential, electric field, drain current, switching metric: ION/IOFF
ratio and transconductance for the proposed design. A good
agreement between the model predictions and device simulation
results is obtained, verifying the accuracy of the proposed analytical
model.
Abstract: Electrophoretic motion of a liquid droplet within an
uncharged cylindrical pore is investigated theoretically in this study. It
is found that the boundary effect in terms of the reduction of droplet
mobility (droplet velocity per unit strength of the applied electric field)
is very significant when the double layer surrounding the droplet is
thick, and diminishes as it gets very thin. Moreover, the viscosity ratio
of the ambient fluid to the internal one, σ, is a crucial factor in
determining its electrophoretic behavior. The boundary effect is less
significant as the viscosity ratio gets high. Up to 70% mobility
reduction is observed when this ratio is low (σ = 0.01), whereas only
40% reduction when it is high (σ = 100). The results of this study can
be utilized in various fields of biotechnology, such as a biosensor or a
lab-on-a-chip device.
Abstract: This paper presents the simulation results of electric field and potential distributions along surface of silicone rubber polymer insulators under clean and various contamination conditions with/without water droplets. Straight sheds insulator having leakage distance 290 mm was used in this study. Two type of contaminants, playwood dust and cement dust, have been studied the effect of contamination on the insulator surface. The objective of this work is to comparison the effect of contamination on potential and electric field distributions along the insulator surface when water droplets exist on the insulator surface. Finite element method (FEM) is adopted for this work. The simulation results show that contaminations have no effect on potential distribution along the insulator surface while electric field distributions are obviously depended on contamination conditions.
Abstract: In order to realize long-lived electric propulsion
systems, we have been investigating an electrodeless plasma thruster.
In our concept, a helicon plasma is accelerated by the magnetic nozzle
for the thrusts production. In addition, the electromagnetic thrust can
be enhanced by the additional radio-frequency rotating electric field
(REF) power in the magnetic nozzle. In this study, a direct
measurement of the electromagnetic thrust and a probe measurement
have been conducted using a laboratory model of the thruster under the
condition without the REF power input. Fromthrust measurement, it is
shown that the thruster produces a sub-milli-newton order
electromagnetic thrust force without the additional REF power. The
thrust force and the density jump are observed due to the discharge
mode transition from the inductive coupled plasma to the helicon wave
excited plasma. The thermal thrust is theoretically estimated, and the
total thrust force, which is a sum of the electromagnetic and the
thermal thrust force and specific impulse are calculated to be up to 650
μN (plasma production power of 400 W, Ar gas mass flow rate of 1.0
mg/s) and 210 s (plasma production power of 400 W, Ar gas mass flow
rate of 0.2 mg/s), respectively.
Abstract: In the present work we model a Multiquantum Well
structure Separate Absorption and Charge Multiplication Avalanche
Photodiode (MQW-SACM-APD), while the Absorption region
coincide with the MQW. We consider the nonuniformity of electric
field using split-step method in active region. This model is based on
the carrier rate equations in the different regions of the device. Using
the model we obtain the photocurrent, and dark current. As an
example, InGaAs/InP SACM-APD and MQW-SACM-APD are
simulated. There is a good agreement between the simulation and
experimental results.
Abstract: In this paper, the computation of the electrical field distribution around AC high-voltage lines is demonstrated. The advantages and disadvantages of two different methods are described to evaluate the electrical field quantity. The first method is a seminumerical method using the laws of electrostatic techniques to simulate the two-dimensional electric field under the high-voltage overhead line. The second method which will be discussed is the finite element method (FEM) using specific boundary conditions to compute the two- dimensional electric field distributions in an efficient way.
Abstract: In this paper, gate leakage current has been mitigated
by the use of novel nanoscale MOSFET with Source/Drain-to-Gate
Non-overlapped and high-k spacer structure for the first time. A
compact analytical model has been developed to study the gate
leakage behaviour of proposed MOSFET structure. The result
obtained has found good agreement with the Sentaurus Simulation.
Fringing gate electric field through the dielectric spacer induces
inversion layer in the non-overlap region to act as extended S/D
region. It is found that optimal Source/Drain-to-Gate Non-overlapped
and high-k spacer structure has reduced the gate leakage current to
great extent as compared to those of an overlapped structure. Further,
the proposed structure had improved off current, subthreshold slope
and DIBL characteristic. It is concluded that this structure solves the
problem of high leakage current without introducing the extra series
resistance.
Abstract: This paper presents the mathematical model of electric field and magnetic field in transmission system, which performs in second-order partial differential equation. This research has conducted analyzing the electromagnetic field radiating to atmosphere around the transmission line, when there is the transmission line transposition in case of long distance distribution. The six types of 500 kV transposed HV transmission line with double circuit will be considered. The computer simulation is applied finite element method that is developed by MATLAB program. The problem is considered to two dimensions, which is time harmonic system with the graphical performance of electric field and magnetic field. The impact from simulation of six types long distance distributing transposition will not effect changing of electric field and magnetic field which surround the transmission line.
Abstract: Estimation of natural frequency of structures is very
important and isn-t usually calculated simply and sometimes
complicated. Lack of knowledge about that caused hard damage and
hazardous effects.
In this paper, with using from two different models in FEM
method and based on hydrodynamic mass of fluids, natural frequency
of an especial bearing (Fig. 1) in an electric field (or, a periodic
force) is calculated in different stiffness and different geometric. In
final, the results of two models and analytical solution are compared.
Abstract: Titanium oxide hollow microspheres were synthesized from organic precursor titanium tetraisopropoxide (TTIP) using continuous spray pyrolysis reactor. Effects of precursor concentration, applied voltage and annealing have been investigated. It was observed that the annealing of the as-synthesized TiO2 hollow microspheres at 2500C, which had an average external diameter of 200 nm, leads to an increase in the size and also more spherical shape. The precursor concentration was found to have a direct impact on the size of the microspheres, which is also evident in the absorption spectrum. The as-prepared TiO2 hollow microspheres exhibited good photocatalytic activity for the degradation of MO.
Abstract: In nature, electromagnetic fields always appear like
atmosphere static electric field, the earth's static magnetic field and
the wide-rang frequency electromagnetic field caused by lightening.
However, besides natural electromagnetic fields (EMF), today human
beings are mostly exposed to artificial electromagnetic fields due to
technology progress and outspread use of electrical devices. To
evaluate nuisance of EMF, it is necessary to know field intensity for
every frequency which appears and compare it with allowed values.
Low frequency EMF-s around transmission and distribution lines are
time-varying quasi-static electromagnetic fields which have
conservative component of low frequency electrical field caused by
charges and eddy component of low frequency magnetic field caused
by currents. Displacement current or field delay are negligible, so
energy flow in quasi-static EMF involves diffusion, analog like heat
transfer. Electrical and magnetic field can be analyzed separately.
This paper analysis the numerical calculations in ELF-400 software
of EMF in distribution substation in shopping center. Analyzing the
results it is possible to specify locations exposed to the fields and
give useful suggestion to eliminate electromagnetic effect or reduce it
on acceptable level within the non-ionizing radiation norms and
norms of protection from EMF.
Abstract: The present work deals with the calculation of
transport properties of Hg0.8Cd0.2Te (MCT) semiconductor in
degenerate case. Due to their energy-band structure, this material
becomes degenerate at moderate doping densities, which are around
1015 cm-3, so that the usual Maxwell-Boltzmann approximation is
inaccurate in the determination of transport parameters. This problem
is faced by using Fermi-Dirac (F-D) statistics, and the non-parabolic
behavior of the bands may be approximated by the Kane model. The
Monte Carlo (MC) simulation is used here to determinate transport
parameters: drift velocity, mean energy and drift mobility versus
electric field and the doped densities. The obtained results are in
good agreement with those extracted from literature.
Abstract: In this paper, the thermo-electro-structural coupledfield
in a cracked metal plate is studied using the finite element
analysis. From the computational results, the compressive stresses
reveal near the crack tip. This conclusion agrees with the past
reference. Furthermore, the compressive condition can retard and stop
the crack growth during the Joule heating process.
Abstract: A power cable is widely used for power supply in
power distributing networks and power transmission lines. Due to
limitations in the production, delivery and setting up power cables,
they are produced and delivered in several separate lengths. Cable
itself, consists of two cable terminations and arbitrary number of
cable joints, depending on the cable route length. Electrical stress
control is needed to prevent a dielectric breakdown at the end of the
insulation shield in both the air and cable insulation. Reliability of
cable joint depends on its materials, design, installation and operating
environment. The paper describes design and performance results for
new modeled cable joints. Design concepts, based on numerical
calculations, must be correct. An Equivalent Electrodes
Method/Boundary Elements Method-hybrid approach that allows
electromagnetic field calculations in multilayer dielectric media,
including inhomogeneous regions, is presented.
Abstract: This paper presents a low cost automatic system for
sampling the electric field in a limited area. The scanning area is a
flat surface parallel to the ground at a selected height. We discuss
in detail the hardware, software and all the arrangements involved
in the system operation. In order to show the system performance
we include a campaign of narrow band measurements with 6017
sample points in the surroundings of a cellular base station. A
commercial isotropic antenna with three orthogonal axes was used
as sampling device. The results are analyzed in terms of its space
average, standard deviation and statistical distribution.