Abstract: For schools to be desirable places in which to work, it
is necessary for principals to recognise their teachers’ emotions, and
be sensitive to their needs. This necessitates that principals are
capable to correctly identify their emotionally intelligent behaviours
(EIBs) they need to use in order to be successful leaders. They also
need to have knowledge of their emotional intelligence and be able to
identify the factors and situations that evoke emotion at an
interpersonal level. If a principal is able to do this, then the control
and understanding of emotions and behaviours of oneself and others
could improve vastly. This study focuses on the interpersonal EIBS
of principals affecting the job satisfaction of teachers. The correlation
coefficients in this quantitative study strongly indicate that there is a
statistical significance between the respondents’ level of job
satisfaction, the rating of their principals’ EIBs and how they believe
their principals’ EIBs will affect their sense of job satisfaction. It can
be concluded from the data obtained in this study that there is a
significant correlation between the sense of job satisfaction of
teachers and their principals’ interpersonal EIBs. This means that the
more satisfied a teacher is at school, the more appropriate and
meaningful a principal’s EIBs will be. Conversely, the more
dissatisfied a teacher is at school the less appropriate and less
meaningful a principal’s interpersonal EIBs will be. This implies that
the leaders’ EIBs can be construed as one of the major factors
affecting the job satisfaction of employees.
Abstract: It has been known that a characteristic
Burst-Suppression (BS) pattern appears in EEG during the early
recovery period following Cardiac Arrest (CA). Here, to explore the
relationship between cortical and subcortical neural activities
underlying BS, extracellular activity in the parietal cortex and the
centromedian nucleus of the thalamus and extradural EEG were
recorded in a rodent CA model. During the BS, the cortical firing rate
is extraordinarily high, and that bursts in EEG correlate to dense spikes
in cortical neurons. Newly observed phenomena are that 1) thalamic
activity reemerges earlier than cortical activity following CA, and 2)
the correlation coefficient of cortical and thalamic activities rises
during BS period. These results would help elucidate the underlying
mechanism of brain recovery after CA injury.
Abstract: Thermal enhancement of a single mini channel in
Proton Exchange Membrane Fuel Cell (PEMFC) cooling plate is
numerically investigated. In this study, low concentration of Al2O3 in
Water - Ethylene Glycol mixtures is used as coolant in single channel
of carbon graphite plate to mimic the mini channels in PEMFC
cooling plate. A steady and incompressible flow with constant heat
flux is assumed in the channel of 1mm x 5mm x 100mm. Nano
particle of Al2O3 used ranges from 0.1, 0.3 and 0.5 vol %
concentration and then dispersed in 60:40 (water: Ethylene Glycol)
mixture. The effect of different flow rates to fluid flow and heat
transfer enhancement in Re number range of 20 to 140 was observed.
The result showed that heat transfer coefficient was improved by
18.11%, 9.86% and 5.37% for 0.5, 0.3 and 0.1 vol. % Al2O3 in 60:40
(water: EG) as compared to base fluid of 60:40 (water: EG). It is also
showed that the higher vol. % concentration of Al2O3 performed
better in term of thermal enhancement but at the expense of higher
pumping power required due to increase in pressure drop
experienced. Maximum additional pumping power of 0.0012W was
required for 0.5 vol % Al2O3 in 60:40 (water: EG) at Re number 140.
Abstract: Structural failure is caused mainly by damage that
often occurs on structures. Many researchers focus on to obtain very
efficient tools to detect the damage in structures in the early state. In
the past decades, a subject that has received considerable attention in
literature is the damage detection as determined by variations in the
dynamic characteristics or response of structures. The study presents
a new damage identification technique. The technique detects the
damage location for the incomplete structure system using output
data only. The method indicates the damage based on the free
vibration test data by using ‘Two Points Condensation (TPC)
technique’. This method creates a set of matrices by reducing the
structural system to two degrees of freedom systems. The current
stiffness matrices obtain from optimization the equation of motion
using the measured test data. The current stiffness matrices compare
with original (undamaged) stiffness matrices. The large percentage
changes in matrices’ coefficients lead to the location of the damage. TPC technique is applied to the experimental data of a simply
supported steel beam model structure after inducing thickness change
in one element, where two cases consider. The method detects the
damage and determines its location accurately in both cases. In
addition, the results illustrate these changes in stiffness matrix can be
a useful tool for continuous monitoring of structural safety using
ambient vibration data. Furthermore, its efficiency proves that this
technique can be used also for big structures.
Abstract: In this paper, we present a quantum statistical
mechanical formulation from our recently analytical expressions for
partial-wave transition matrix of a three-particle system. We report
the quantum reactive cross sections for three-body scattering
processes 1+(2,3)→1+(2,3) as well as recombination
1+(2,3)→1+(3,1) between one atom and a weakly-bound dimer. The
analytical expressions of three-particle transition matrices and their
corresponding cross-sections were obtained from the threedimensional
Faddeev equations subjected to the rank-two non-local
separable potentials of the generalized Yamaguchi form. The
equilibrium quantum statistical mechanical properties such partition
function and equation of state as well as non-equilibrium quantum
statistical properties such as transport cross-sections and their
corresponding transport collision integrals were formulated
analytically. This leads to obtain the transport properties, such as
viscosity and diffusion coefficient of a moderate dense gas.
Abstract: This paper presents the results of a Finite Element
based vibration analysis of a solar powered Unmanned Aerial
Vehicle (UAV). The purpose of this paper was to quantify the free
vibration, forced vibration response due to differing point inputs in
order to predict the relative response magnitudes and frequencies at
various wing locations of vibration induced power generators
(magnet in coil) excited by gust and/or control surface pulse-decays
used to help power the flight of the electric UAV. A Fluid Structure
Interaction (FSI) study was performed in order to ascertain pertinent
design stresses and deflections as well as aerodynamic parameters of
the UAV airfoil. The 10 ft span airfoil is modeled using Mylar as the
primary material. Results show that the free mode in bending is 4.8
Hz while the first forced bending mode is on range of 16.2 to 16.7 Hz
depending on the location of excitation. The free torsional bending
mode is 28.3 Hz, and the first forced torsional mode is range of 26.4
to 27.8 Hz, depending on the location of excitation. The FSI results
predict the coefficients of aerodynamic drag and lift of 0.0052 and
0.077, respectively, which matches hand-calculations used to validate
the Finite Element based results. FSI based maximum von Mises
stresses and deflections were found to be 0.282 MPa and 3.4 mm,
respectively. Dynamic pressures on the airfoil range from 1.04 to
1.23 kPa corresponding to velocity magnitudes in range of 22 to 66
m/s.
Abstract: In this paper, a spatial multiple-kernel fuzzy C-means (SMKFCM) algorithm is introduced for segmentation problem. A linear combination of multiples kernels with spatial information is used in the kernel FCM (KFCM) and the updating rules for the linear coefficients of the composite kernels are derived as well. Fuzzy cmeans (FCM) based techniques have been widely used in medical image segmentation problem due to their simplicity and fast convergence. The proposed SMKFCM algorithm provides us a new flexible vehicle to fuse different pixel information in medical image segmentation and detection of MR images. To evaluate the robustness of the proposed segmentation algorithm in noisy environment, we add noise in medical brain tumor MR images and calculated the success rate and segmentation accuracy. From the experimental results it is clear that the proposed algorithm has better performance than those of other FCM based techniques for noisy medical MR images.
Abstract: Due to the interference effects, the intrinsic
aerodynamic parameters obtained from the individual component
testing are always fundamentally different than those obtained for
complete model testing. Consideration and limitation for such testing
need to be taken into account in any design work related to the
component buildup method. In this paper, the scaled model of a
straight rectangular canard of a hybrid buoyant aircraft is tested at 50
m/s in IIUM-LSWT (Low Speed Wind Tunnel). Model and its
attachment with the balance are kept rigid to have results free from
the aeroelastic distortion. Based on the velocity profile of the test
section’s floor; the height of the model is kept equal to the
corresponding boundary layer displacement. Balance measurements
provide valuable but limited information of overall aerodynamic
behavior of the model. Zero lift coefficient is obtained at -2.2o and
the corresponding drag coefficient was found to be less than that at
zero angle of attack. As a part of the validation of low fidelity tool,
plot of lift coefficient plot was verified by the experimental data and
except the value of zero lift coefficients, the overall trend has under
predicted the lift coefficient. Based on this comparative study, a
correction factor of 1.36 is proposed for lift curve slope obtained
from the panel method.
Abstract: MHD chemically reacting viscous fluid flow towards
a vertical surface with slip and convective boundary conditions has
been conducted. The temperature and the chemical species
concentration of the surface and the velocity of the external flow are
assumed to vary linearly with the distance from the vertical surface.
The governing differential equations are modeled and transformed
into systems of ordinary differential equations, which are then solved
numerically by a shooting method. The effects of various parameters
on the heat and mass transfer characteristics are discussed. Graphical
results are presented for the velocity, temperature, and concentration
profiles whilst the skin-friction coefficient and the rate of heat and
mass transfers near the surface are presented in tables and discussed.
The results revealed that increasing the strength of the magnetic field
increases the skin-friction coefficient and the rate of heat and mass
transfers toward the surface. The velocity profiles are increased
towards the surface due to the presence of the Lorenz force, which
attracts the fluid particles near the surface. The rate of chemical
reaction is seen to decrease the concentration boundary layer near the
surface due to the destructive chemical reaction occurring near the
surface.
Abstract: The current study aims to highlight the loading
characteristics impact on the time evolution (focusing particularly on
long term effects) of the deformation of realized reinforced concrete
beams. Namely the tension stiffening code provisions (i.e. within
Eurocode 2) are reviewed with a clear intention to reassess their
operational value and predicting capacity. In what follows the
experimental programme adopted along with some preliminary
findings and numerical modeling attempts are presented. For a range of long slender reinforced concrete simply supported
beams (4200 mm) constant static sustained and repeated cyclic
loadings were applied mapping the time evolution of deformation.
All experiments were carried out at the Heavy Structures Lab of the
University of Leeds. During tests the mid-span deflection, creep
coefficient and shrinkage strains were monitored for duration of 90
days. The obtained results are set against the values predicted by
Eurocode 2 and the tools within an FE commercial package (i.e.
Midas FEA) to yield that existing knowledge and practise is at times
over-conservative.
Abstract: One of the most important challenging factors in
medical images is nominated as noise. Image denoising refers to the
improvement of a digital medical image that has been infected by
Additive White Gaussian Noise (AWGN). The digital medical image
or video can be affected by different types of noises. They are
impulse noise, Poisson noise and AWGN. Computed tomography
(CT) images are subjects to low quality due to the noise. Quality of
CT images is dependent on absorbed dose to patients directly in such
a way that increase in absorbed radiation, consequently absorbed
dose to patients (ADP), enhances the CT images quality. In this
manner, noise reduction techniques on purpose of images quality
enhancement exposing no excess radiation to patients is one the
challenging problems for CT images processing. In this work, noise
reduction in CT images was performed using two different
directional 2 dimensional (2D) transformations; i.e., Curvelet and
Contourlet and Discrete Wavelet Transform (DWT) thresholding
methods of BayesShrink and AdaptShrink, compared to each other
and we proposed a new threshold in wavelet domain for not only
noise reduction but also edge retaining, consequently the proposed
method retains the modified coefficients significantly that result good
visual quality. Data evaluations were accomplished by using two
criterions; namely, peak signal to noise ratio (PSNR) and Structure
similarity (Ssim).
Abstract: This paper aims to study the heat transfer and fluid
flow characteristics of nanofluids used in spray cooling systems. The
effect of spray height, type of nanofluids and concentration of
nanofluids are numerically investigated. Five different nanofluids
such as AgH2O, Al2O3, CuO, SiO2 and TiO2 with volume fraction
range of 0.5% to 2.5% are used. The results revealed that the heat
transfer performance decreases as spray height increases. It is found
that TiO2 has the highest transfer coefficient among other nanofluids.
In dilute spray conditions, low concentration of nanofluids is
observed to be more effective in heat removal in a spray cooling
system.
Abstract: In this paper, we study the optical nonlinearities of
Silver sulfide (Ag2S) nanostructures dispersed in the Dimethyl
sulfoxide (DMSO) under exposure to 532 nm, 15 nanosecond (ns)
pulsed laser irradiation. Ultraviolet–visible absorption spectrometry
(UV-Vis), X-ray diffraction (XRD), and transmission electron
microscopy (TEM) are used to characterize the obtained nanocrystal
samples. The band gap energy of colloid is determined by analyzing
the UV–Vis absorption spectra of the Ag2S NPs using the band
theory of semiconductors. Z-scan technique is used to characterize
the optical nonlinear properties of the Ag2S nanoparticles (NPs).
Large enhancement of two photon absorption effect is observed with
increase in concentration of the Ag2S nanoparticles using open Zscan
measurements in the ns laser regime. The values of the nonlinear
absorption coefficients are determined based on the local nonlinear
responses including two photon absorption. The observed aperture
dependence of the Ag2S NP limiting performance indicates that the
nonlinear scattering plays an important role in the limiting action of
the sample. The concentration dependence of the optical liming is
also investigated. Our results demonstrate that the optical limiting
threshold decreases with increasing the silver sulfide NPs in DMSO.
Abstract: Nowadays, energy dissipation devices are commonly
used in structures. High rate of energy absorption during earthquakes
is the benefit of using such devices, which results in damage
reduction of structural elements, specifically columns. The hysteretic
damping capacity of energy dissipation devices is the key point that it
may adversely make analysis and design process complicated. This
effect may be generally represented by Equivalent Viscous Damping
(EVD). The equivalent viscous damping might be obtained from the
expected hysteretic behavior regarding to the design or maximum
considered displacement of a structure. In this paper, the hysteretic
damping coefficient of a steel Moment Resisting Frame (MRF),
which its performance is enhanced by a Buckling Restrained Brace
(BRB) system has been evaluated. Having foresight of damping
fraction between BRB and MRF is inevitable for seismic design
procedures like Direct Displacement-Based Design (DDBD) method.
This paper presents an approach to calculate the damping fraction for
such systems by carrying out the dynamic nonlinear time history
analysis (NTHA) under harmonic loading, which is tuned to the
natural system frequency. Two MRF structures, one equipped with
BRB and the other without BRB are simultaneously studied.
Extensive analysis shows that proportion of each system damping
fraction may be calculated by its shear story portion. In this way,
contribution of each BRB in the floors and their general contribution
in the structural performance may be clearly recognized, in advance.
Abstract: In this paper, to model a real life wind turbine, a
probabilistic approach is proposed to model the dynamics of the
blade elements of a small axial wind turbine under extreme stochastic
wind speeds conditions. It was found that the power and the torque
probability density functions even-dough decreases at these extreme
wind speeds but are not infinite. Moreover, we also fund that it
is possible to stabilize the power coefficient (stabilizing the output
power)above rated wind speeds by turning some control parameters.
This method helps to explain the effect of turbulence on the quality
and quantity of the harness power and aerodynamic torque.
Abstract: Electrohydraulic servo system have been used in
industry in a wide number of applications. Its dynamics are highly
nonlinear and also have large extent of model uncertainties and
external disturbances. In this paper, a robust back-stepping control
(RBSC) scheme is proposed to overcome the problem of disturbances
and system uncertainties effectively and to improve the tracking
performance of EHS systems. In order to implement the proposed
control scheme, the system uncertainties in EHS systems are
considered as total leakage coefficient and effective oil volume. In
addition, in order to obtain the virtual controls for stabilizing system,
the update rule for the system uncertainty term is induced by
the Lyapunov control function (LCF). To verify the performance and
robustness of the proposed control system, computer simulation of
the proposed control system using Matlab/Simulink Software
is executed. From the computer simulation, it was found that the
RBSC system produces the desired tracking performance and has
robustness to the disturbances and system uncertainties of EHS
systems.
Abstract: Useful lifetime evaluation of chevron rubber spring
was very important in design procedure to assure the safety and
reliability. It is, therefore, necessary to establish a suitable criterion
for the replacement period of chevron rubber spring. In this study, we
performed characteristic analysis and useful lifetime prediction of
chevron rubber spring. Rubber material coefficient was obtained by
curve fittings of uniaxial tension equibiaxial tension and pure shear
test. Computer simulation was executed to predict and evaluate the
load capacity and stiffness for chevron rubber spring. In order to
useful lifetime prediction of rubber material, we carried out the
compression set with heat aging test in an oven at the temperature
ranging from 50°C to 100°C during a period 180 days. By using the
Arrhenius plot, several useful lifetime prediction equations for rubber
material was proposed.
Abstract: Speaker Identification (SI) is the task of establishing
identity of an individual based on his/her voice characteristics. The SI
task is typically achieved by two-stage signal processing: training and
testing. The training process calculates speaker specific feature
parameters from the speech and generates speaker models
accordingly. In the testing phase, speech samples from unknown
speakers are compared with the models and classified. Even though
performance of speaker identification systems has improved due to
recent advances in speech processing techniques, there is still need of
improvement. In this paper, a Closed-Set Tex-Independent Speaker
Identification System (CISI) based on a Multiple Classifier System
(MCS) is proposed, using Mel Frequency Cepstrum Coefficient
(MFCC) as feature extraction and suitable combination of vector
quantization (VQ) and Gaussian Mixture Model (GMM) together
with Expectation Maximization algorithm (EM) for speaker
modeling. The use of Voice Activity Detector (VAD) with a hybrid
approach based on Short Time Energy (STE) and Statistical
Modeling of Background Noise in the pre-processing step of the
feature extraction yields a better and more robust automatic speaker
identification system. Also investigation of Linde-Buzo-Gray (LBG)
clustering algorithm for initialization of GMM, for estimating the
underlying parameters, in the EM step improved the convergence rate
and systems performance. It also uses relative index as confidence
measures in case of contradiction in identification process by GMM
and VQ as well. Simulation results carried out on voxforge.org
speech database using MATLAB highlight the efficacy of the
proposed method compared to earlier work.
Abstract: Barley (Hordeum vulgare L.), vetch (Vicia villosa),
and grass pea (Lathyrus sativus L.) monocultures as well as mixtures
of barley with each of the above legumes, in three seeding ratios (i.e.,
barley: legume 75:25, 50:50 and 25:75, based on seed numbers) were
used to investigated forage yield and competition indices. The results
showed that intercropping reduced the dry matter yield of the three
component plants, compared with their respective monocrops. The
greatest value of total dry matter yield was obtained from barley25-
grasspea75 (5.44 t ha-1) mixture, followed by grass pea sole crop (4.99
t ha-1). The total actual yield loss (AYL) values were positive and
greater than 0 in all mixtures, indicating an advantage from
intercropping over sole crops. Intercropped barley had a higher
relative crowding coefficient (K=1.64) than intercropped legumes
(K=1.20), indicating that barley was more competitive than legumes
in mixtures. Furthermore, grass pea was more competitive than vetch
in mixtures with barley. The highest land equivalent ratio (LER),
system productivity index (SPI) and monetary advantage index
(MAI) were obtained when barley was mixed at a rate of 25% with
75% seed rate of grass pea. It is concluded that intercropping of
barley with grass pea has a good potential to improve the
performance of forage with high land-use efficiency.
Abstract: In order to obtain efficient pollutants removal in
small-scale wastewater treatment plants, uniform water flow has to be
achieved. The experimental setup, designed for treating high-load
wastewater (leachate), consists of two aerobic biological reactors and
a lamellar settler. Both biological tanks were aerated by using three
different types of aeration systems - perforated pipes, membrane air
diffusers and tube ceramic diffusers. The possibility of homogenizing
the water mass with each of the air diffusion systems was evaluated
comparatively. The oxygen concentration was determined by optical
sensors with data logging. The experimental data was analyzed
comparatively for all three different air dispersion systems aiming to
identify the oxygen concentration variation during different
operational conditions. The Oxygenation Capacity was calculated for
each of the three systems and used as performance and selection
parameter. The global mass transfer coefficients were also evaluated
as important tools in designing the aeration system. Even though
using the tubular porous diffusers leads to higher oxygen
concentration compared to the perforated pipe system (which
provides medium-sized bubbles in the aqueous solution), it doesn’t
achieve the threshold limit of 80% oxygen saturation in less than 30
minutes. The study has shown that the optimal solution for the
studied configuration was the radial air diffusers which ensure an
oxygen saturation of 80% in 20 minutes. An increment of the values
was identified when the air flow was increased.