Abstract: This article presents a vibration diagnostic method
designed for Permanent Magnets (PM) electrical machines–traction
motors and generators. Those machines are commonly used in traction
drives of electrical vehicles and small wind or water systems. The
described method is very innovative and unique. Specific structural
properties of machines excited by permanent magnets are used in this
method - electromotive force (EMF) generated due to vibrations. There
was analyzed number of publications, which describe vibration
diagnostic methods, and tests of electrical machines and there was no
method found to determine the technical condition of such machine
basing on their own signals. This work presents field-circuit model,
results of static tests, results of calculations and simulations.
Abstract: Currently, green rating systems are mainly utilized for
correctly sizing mechanical and electrical systems, which have short
lifetime expectancies. In these systems, passive solar and bio-climatic
architecture, which have long lifetime expectancies, are neglected.
Urban rating systems consider buildings and services in addition to
neighborhoods and public transportation as integral parts of the built
environment. The main goal of this study was to develop a more
consistent point allocation system for urban building standards by
using six different lifetime shearing layers: Site, Structure, Skin,
Services, Space, and Stuff, each reflecting distinct environmental
damages. This shearing-layer concept was applied to internationally
well-known rating systems: Leadership in Energy and Environmental
Design (LEED) for Neighborhood Development, BRE
Environmental Assessment Method (BREEAM) for Communities
and Comprehensive Assessment System for Building Environmental
Efficiency (CASBEE) for Urban Development. The results showed
that LEED for Neighborhood Development and BREEAM for
Communities focused on long-lifetime-expectancy building designs,
whereas CASBEE for Urban Development gave equal importance to
the Building and Service Layers. Moreover, although this rating
system was applied using a building-scale assessment, “Urban Area +
Buildings” focuses on a short-lifetime-expectancy system design,
neglecting to improve the architectural design by considering bioclimatic
and passive solar aspects.
Abstract: An experimental investigation is carried out to
establish the performance characteristics of a compression ignition
engine while using cerium oxide nanoparticles as additive in neat
diesel and diesel-biodiesel blends. In the first phase of the
experiments, stability of neat diesel and diesel-biodiesel fuel blends
with the addition of cerium oxide nanoparticles is analyzed. After
series of experiments, it is found that the blends subjected to high
speed blending followed by ultrasonic bath stabilization improves the
stability. In the second phase, performance characteristics are studied
using the stable fuel blends in a single cylinder four stroke engine
coupled with an electrical dynamometer and a data acquisition
system. The cerium oxide acts as an oxygen donating catalyst and
provides oxygen for combustion. The activation energy of cerium
oxide acts to burn off carbon deposits within the engine cylinder at
the wall temperature and prevents the deposition of non-polar
compounds on the cylinder wall results reduction in HC emissions.
The tests revealed that cerium oxide nanoparticles can be used as
additive in diesel and diesel-biodiesel blends to improve complete
combustion of the fuel significantly.
Abstract: This paper represents an experimental study of LPG
diffusion flame at elevated preheated air temperatures. The flame is
stabilized in a vertical water-cooled combustor by using air swirler. An
experimental test rig was designed to investigate the different
operating conditions. The burner head is designed so that the LPG fuel
issued centrally and surrounded by the swirling air issues from an air
swirler. There are three air swirlers having the same dimensions but
having different blade angles to give different swirl numbers of 0.5,
0.87 and 1.5. The combustion air was heated electrically before
entering the combustor up to a temperature about 500 K. Five air to
fuel mass ratios of 15, 20, 30, 40 and 50 were also studied. The effect
of preheated air temperature, swirl number and air to fuel mass ratios
on the temperature maps, visible flame length, high temperature region
(size) and exhaust species concentrations are studied. Some results
show that as the preheated air temperature increases, the volume of
high temperature region also increased but the flame length decreased.
Increasing the preheated air temperature, EINOx, EICO2 and EIO2
increased, while EICO decreased. Increasing the preheated air
temperature from 300 to 500 K, for all air swirl numbers used, the
highest increase in EINOx, EICO2 and EIO2 are 141, 4 and 65%,
respectively.
Abstract: The synthesis of CuFe2O4 spinel powders by an
optimized combustion-like process followed by calcination is
described herein. The samples were characterized using X-ray
diffraction (XRD), differential thermal analysis (TG/DTA), scanning
electron microscopy (SEM), dilatometry and 4-probe DC methods.
Different glycine to nitrate (G/N) ratios of 1 (fuel-deficient), 1.48
(stoichiometric) and 2 (fuel-rich) were employed. Calcining the asprepared
powders at 800 and 1000°C for 5 hours showed that the G/N
ratio of 2 results in the formation of the desired copper spinel single
phase at both calcination temperatures. For G/N=1, formation of
CuFe2O4 takes place in three steps. First, iron and copper nitrates
decompose to iron oxide and pure copper. Then, copper transforms to
copper oxide and finally, copper and iron oxides react with each other
to form a copper ferrite spinel phase. The electrical conductivity and
the coefficient of thermal expansion of the sintered pelletized
samples were 2 S.cm-1 (800°C) and 11×10-6 °C-1 (25-800°C),
respectively.
Abstract: Polyaniline is an indispensible component in lightemitting
devices (LEDs), televisions, cellular telephones, automotive,
corrosion-resistant coatings, actuators etc. The electrical conductivity
properties was found be increased by introduction of metal nano
particles. In the present study, an attempt has been made to utilize
platinum nano particles to achieve the improved electrical properties.
Polyaniline and Pt-polyaniline composite are synthesized by
electrochemical routes. X-ray diffractometer confirms the amorphous
nature of polyaniline. The Bragg’s diffraction peaks correspond to
platinum nanoparticles in Pt-polyaniline composite and
thermogravimetric analyzer indicates its decomposition at certain
temperature. The Scanning Electron Micrographs of colloidal
platinum nanoparticles were spherical, uniform shape in the
composite. The current-voltage (I-V) characteristics of the PANI and
composites were also studied which indicate a significant decreasing
resistivity than PANI-Platinum after introduction of pt nanoparticles
in the matrix of polyaniline (PANI).
Abstract: Transparent nickel doped cobalt sulfide was fabricated
on a SnO2:F electrode and tested as an efficient electrocatalyst and as
an alternative to the expensive platinum counter electrode. In order to
investigate how this electrode could affect the electrical
characteristics of a dye-sensitized solar cell, we manufactured cells
with the same TiO2 photoanode sensitized with dye (N719) and
employing the same quasi-solid electrolyte, altering only the counter
electrode used. The cells were electrically and electrochemically
characterized and it was observed that the ones with the Ni doped
CoS2 outperformed the efficiency of the cells with the Pt counter
electrode (3.76% and 3.44% respectively). Particularly, the higher
efficiency of the cells with the Ni doped CoS2 counter electrode (CE)
is mainly because of the enhanced photocurrent density which is
attributed to the enhanced electrocatalytic ability of the CE and the
low charge transfer resistance at the CE/electrolyte interface.
Abstract: RF magnetron sputtering is used on the ceramic targets,
each of which contains zinc oxide (ZnO), zinc oxide doped with
aluminum (AZO) and zinc oxide doped with gallium (GZO). The XRD
analysis showed a preferred orientation along the (002) plane for ZnO,
AZO, and GZO films. The AZO film had the best electrical properties;
it had the lowest resistivity of 6.6 × 10-4 cm, the best sheet resistance of
2.2 × 10-1 Ω/square, and the highest carrier concentration of 4.3 × 1020
cm-3, as compared to the ZnO and GZO films.
Abstract: In this study, the signal of brain electrical activities of
the sixteen students selected from the Department of Electrical and
Energy at Usak University have been recorded during a lecturer
performed happiness emotions for the first group and anger emotions
for the second group in different time while the groups were in the
classroom separately. The attention and meditation data extracted
from the recorded signals have been analyzed and evaluated toward
the teacher’s specific emotion states simultaneously. Attention levels
of students who are under influence of happiness emotions of the
lecturer have a positive trend and attention levels of students who are
under influence of anger emotions of the lecturer have a negative
trend. The meditation or mental relaxation levels of students who are
under influence of happiness emotions of the lecturer are 34.3%
higher comparing with the mental relaxation levels of students who
are under influence of anger emotions of the lecturer.
Abstract: The work aims to develop a robot in the form of
autonomous vehicle to detect, inspection and mapping of
underground pipelines through the ATmega328 Arduino platform.
Hardware prototyping is very similar to C / C ++ language that
facilitates its use in robotics open source, resembles PLC used in
large industrial processes. The robot will traverse the surface
independently of direct human action, in order to automate the
process of detecting buried pipes, guided by electromagnetic
induction. The induction comes from coils that send the signal to the
Arduino microcontroller contained in that will make the difference in
intensity and the treatment of the information, and then this
determines actions to electrical components such as relays and
motors, allowing the prototype to move on the surface and getting the
necessary information. This change of direction is performed by a
stepper motor with a servo motor. The robot was developed by
electrical and electronic assemblies that allowed test your application.
The assembly is made up of metal detector coils, circuit boards and
microprocessor, which interconnected circuits previously developed
can determine, process control and mechanical actions for a robot
(autonomous car) that will make the detection and mapping of buried
pipelines plates. This type of prototype can prevent and identifies
possible landslides and they can prevent the buried pipelines suffer an
external pressure on the walls with the possibility of oil leakage and
thus pollute the environment.
Abstract: Neural activity in the human brain starts from the
early stages of prenatal development. This activity or signals
generated by the brain are electrical in nature and represent not only
the brain function but also the status of the whole body. At the
present moment, three methods can record functional and
physiological changes within the brain with high temporal resolution
of neuronal interactions at the network level: the
electroencephalogram (EEG), the magnet oencephalogram (MEG),
and functional magnetic resonance imaging (fMRI); each of these has
advantages and shortcomings. EEG recording with a large number of
electrodes is now feasible in clinical practice. Multichannel EEG
recorded from the scalp surface provides very valuable but indirect
information about the source distribution. However, deep electrode
measurements yield more reliable information about the source
locations intracranial recordings and scalp EEG are used with the
source imaging techniques to determine the locations and strengths of
the epileptic activity. As a source localization method, Low
Resolution Electro-Magnetic Tomography (LORETA) is solved for
the realistic geometry based on both forward methods, the Boundary
Element Method (BEM) and the Finite Difference Method (FDM). In
this paper, we review the findings EEG- LORETA about epilepsy.
Abstract: An Acoustic Micro-Energy Harvester (AMEH) is
developed to convert wasted acoustical energy into useful electrical
energy. AMEH is mathematically modeled using Lumped Element
Modelling (LEM) and Euler-Bernoulli beam (EBB) modelling. An
experiment is designed to validate the mathematical model and assess
the feasibility of AMEH. Comparison of theoretical and experimental
data on critical parameter value such as Mm, Cms, dm and Ceb showed
the variances are within 1% to 6%, which is reasonably acceptable.
Then, AMEH undergoes bandwidth tuning for performance
optimization. The AMEH successfully produces 0.9V/(m/s^2) and
1.79μW/(m^2/s^4) at 60Hz and 400kΩ resistive load which only
show variances about 7% compared to theoretical data. At 1g and
60Hz resonance frequency, the averaged power output is about
2.2mW which fulfilled a range of wireless sensors and
communication peripherals power requirements. Finally, the design
for AMEH is assessed, validated and deemed as a feasible design.
Abstract: The sea waves carry thousands of GWs of power
globally. Although there are a number of different approaches to
harness offshore energy, they are likely to be expensive, practically
challenging, and vulnerable to storms. Therefore, this paper considers
using the near shore waves for generating mechanical and electrical
power. It introduces two new approaches, the wave manipulation and
using a variable duct turbine, for intercepting very wide wave fronts
and coping with the fluctuations of the wave height and the sea level,
respectively. The first approach effectively allows capturing much
more energy yet with a much narrower turbine rotor. The second
approach allows using a rotor with a smaller radius but captures
energy of higher wave fronts at higher sea levels yet preventing it
from totally submerging. To illustrate the effectiveness of the first
approach, the paper contains a description and the simulation results
of a scale model of a wave manipulator. Then, it includes the results
of testing a physical model of the manipulator and a single duct, axial
flow turbine in a wave flume in the laboratory. The paper also
includes comparisons of theoretical predictions, simulation results,
and wave flume tests with respect to the incident energy, loss in wave
manipulation, minimal loss, brake torque, and the angular velocity.
Abstract: In this paper, we proposed a novel SCR (Silicon Controlled
Rectifier) - based ESD (Electrostatic Discharge) protection device for I/O
and power clamp. The proposed device has a higher holding voltage
characteristic than conventional SCR. These characteristics enable to have
latch-up immunity under normal operating conditions as well as superior full
chip ESD protection. The proposed device was analyzed to figure out
electrical characteristics and tolerance robustness in term of individual
design parameters (D1, D2, D3). They are investigated by using the
Synopsys TCAD simulator. As a result of simulation, holding voltage
increased with different design parameters. The holding voltage of the
proposed device changes from 3.3V to 7.9V. Also, N-Stack structure ESD
device with the high holding voltage is proposed. In the simulation results,
2-stack has holding voltage of 6.8V and 3-stack has holding voltage of
10.5V. The simulation results show that holding voltage of stacking
structure can be larger than the operation voltage of high-voltage
application.
Abstract: In this study, three robust predicting methods, namely artificial neural network (ANN), adaptive neuro fuzzy inference system (ANFIS) and support vector machine (SVM) were used for computing the resonant frequency of A-shaped compact microstrip antennas (ACMAs) operating at UHF band. Firstly, the resonant frequencies of 144 ACMAs with various dimensions and electrical parameters were simulated with the help of IE3D™ based on method of moment (MoM). The ANN, ANFIS and SVM models for computing the resonant frequency were then built by considering the simulation data. 124 simulated ACMAs were utilized for training and the remaining 20 ACMAs were used for testing the ANN, ANFIS and SVM models. The performance of the ANN, ANFIS and SVM models are compared in the training and test process. The average percentage errors (APE) regarding the computed resonant frequencies for training of the ANN, ANFIS and SVM were obtained as 0.457%, 0.399% and 0.600%, respectively. The constructed models were then tested and APE values as 0.601% for ANN, 0.744% for ANFIS and 0.623% for SVM were achieved. The results obtained here show that ANN, ANFIS and SVM methods can be successfully applied to compute the resonant frequency of ACMAs, since they are useful and versatile methods that yield accurate results.
Abstract: Hybrid electric vehicles can reduce pollution and
improve fuel economy. Power-split hybrid electric vehicles (HEVs)
provide two power paths between the internal combustion engine
(ICE) and energy storage system (ESS) through the gears of an
electrically variable transmission (EVT). EVT allows ICE to operate
independently from vehicle speed all the time. Therefore, the ICE can
operate in the efficient region of its characteristic brake specific fuel
consumption (BSFC) map. The two-mode powertrain can operate in
input-split or compound-split EVT modes and in four different fixed
gear configurations. Power-split architecture is advantageous because
it combines conventional series and parallel power paths. This
research focuses on input-split and compound-split modes in the
two-mode power-split powertrain. Fuzzy Logic Control (FLC) for an
internal combustion engine (ICE) and PI control for electric machines
(EMs) are derived for the urban driving cycle simulation. These
control algorithms reduce vehicle fuel consumption and improve ICE
efficiency while maintaining the state of charge (SOC) of the energy
storage system in an efficient range.
Abstract: Microstructural and electrical properties of
Cu-chromium alloy (Cu-Cr) dispersed with vapor-grown carbon fiber
(VGCF) prepared by powder metallurgy (P/M) process have been
investigated. Cu-0.7 mass% Cr pre-alloyed powder (Cu-Cr) made by
water atomization process was used as raw materials, which contained
solid solute Cr elements in Cu matrix. The alloy powder coated with
un-bundled VGCF by using oil coating process was consolidated at
1223 K in vacuum by spark plasma sintering, and then extruded at
1073 K. The extruded Cu-Cr alloy (monolithic alloy) had 209.3 MPa
YS and 80.4 IACS% conductivity. The extruded Cu-Cr with 0.1
mass% VGCF composites revealed a small decrease of YS compared
to the monolithic Cu-Cr alloy. On the other hand, the composite had a
higher electrical conductivity than that of the monolithic alloy. For
example, Cu-Cr with 0.1 mass% VGCF composite sintered for 5 h
showed 182.7 MPa YS and 89.7 IACS% conductivity. In the case of
Cu-Cr with VGCFs composites, the Cr concentration was observed
around VGCF by SEM-EDS analysis, where Cr23C6 compounds were
detected by TEM observation. The amount of Cr solid solution in the
matrix of the Cu-Cr composites alloy was about 50% compared to the
monolithic Cu-Cr sintered alloy, and resulted in the remarkable
increment of the electrical conductivity.
Abstract: Background: Worldwide, at least 2.8 million people
die each year as a result of being overweight or obese, and 35.8
million (2.3%) of global DALYs are caused by overweight or
obesity. Obesity is acknowledged as one of the burning public
health problems reducing life expectancy and quality of life. The
body composition analysis of the university population is essential
in assessing the nutritional status, as well as the risk of developing
diseases associated with abnormal body fat content so as to make
nutritional recommendations. Objectives: The main aim was to
determine the prevalence of obesity and overweight in University
students using Anthropometric analysis and BIA methods. Material
and Methods: In this cross-sectional study, 283 university students
participated. The body composition analysis was undertaken by
using mainly: i) Anthropometric Measurement: Height, Weight,
BMI, waist circumference, hip circumference and skin fold
thickness, ii) Bio-electrical impedance was used for analysis of
body fat mass, fat percent and visceral fat which was measured by
Tanita SC-330P Professional Body Composition Analyzer. The
data so collected were compiled in MS Excel and analyzed for
males and females using SPSS 16. Results and Discussion: The
mean age of the male (n= 153) studied subjects was 25.37 ±2.39
years and females (n=130) was 22.53 ±2.31. The data of BIA
revealed very high mean fat per cent of the female subjects i.e.
30.3±6.5 per cent whereas mean fat per cent of the male subjects
was 15.60±6.02 per cent indicating a normal body fat range. The
findings showed high visceral fat of both males (12.92±3.02) and
females (16.86±4.98). BMI, BF% and WHR were higher among
females, and BMI was higher among males. The most evident
correlation was verified between BF% and WHR for female
students (r=0.902; p
Abstract: This article presents two methods for the
compensation of harmonics generated by a nonlinear load. The first is
the classic method P-Q. The second is the controller by modern
method of artificial intelligence specifically fuzzy logic. Both
methods are applied to a shunt Active Power Filter (sAPF) based on a
three-phase voltage converter at five levels NPC topology. In
calculating the harmonic currents of reference, we use the algorithm
P-Q and pulse generation, we use the intersective PWM. For
flexibility and dynamics, we use fuzzy logic. The results give us clear
that the rate of Harmonic Distortion issued by fuzzy logic is better
than P-Q.
Abstract: Dielectric ceramic samples in the BaO-Re2O3-TiO2
ternary system were synthesized with structural formula Ba2-
xRe4+2x/3Ti8O24 where Re= rare earth metal and Re= Sm and La where
x varies from 0.0 to 0.6 with step size 0.1. Polycrystalline samples
were prepared by the conventional solid state reaction technique. The
dielectric, electrical and impedance analysis of all the samples in the
frequency range 1KHz- 1MHz at room temperature (25°C) have been
done to get the understanding of electrical conduction and dielectric
relaxation and their correlation. Dielectric response of the samples at
lower frequencies shows dielectric dispersion while at higher
frequencies it shows dielectric relaxation. The ac conductivity is well
fitted by the Jonscher law. The spectroscopic data in the impedance
plane confirms the existence of grain contribution to the relaxation.
All the properties are found out to be function of frequency as well as
the amount of substitution.