Abstract: Si-Ge solid solutions (bulk poly- and mono-crystalline
samples, thin films) are characterized by high perspectives for
application in semiconductor devices, in particular, optoelectronics
and microelectronics. From this point of view, complex studying of
structural state of the defects and structural-sensitive physical
properties of Si-Ge solid solutions depending on the contents of Si
and Ge components is very important. Present work deals with the
investigations of microstructure, microhardness, internal friction and
shear modulus of Si1-xGex(x≤0,02) bulk monocrystals conducted at
room temperature. Si-Ge bulk crystals were obtained by Czochralski
method in [111] crystallographic direction. Investigated
monocrystalline Si-Ge samples are characterized by p-type
conductivity and carriers’ concentration 5.1014-1.1015cm-3.
Microhardness was studied on Dynamic Ultra Micro hardness Tester
DUH-201S with Berkovich indenter. Investigate samples are characterized with 0,5x0,5x(10-15)mm3
sizes, oriented along [111] direction at torsion oscillations ≈1Hz,
multistage changing of internal friction and shear modulus has been
revealed in an interval of strain amplitude of 10-5-5.10-3. Critical
values of strain amplitude have been determined at which hysteretic
changes of inelastic characteristics and microplasticity are observed. The critical strain amplitude and elasticity limit values are also
determined. Dynamic mechanical characteristics decreasing trend is
shown with increasing Ge content in Si-Ge solid solutions. Observed
changes are discussed from the point of view of interaction of various
dislocations with point defects and their complexes in a real structure
of Si-Ge solid solutions.
Abstract: Urinary Tract Infections are considered as one of the
most common bacterial infections with an estimated annual global
incidence of 150 million. Antimicrobial drug resistance is one of the
major threats due to wide spread usage of uncontrolled antibiotics. In
this study, a total number of 9149 urine samples were collected from
R.H Patiala and processed in the Department of Microbiology G. M.
C Patiala (January 2013 to December 2013). Urine samples were
inoculated on MacConkey’s and blood agar plates and incubated at
370C for 24 hrs. The organisms were identified by colony characters,
Gram’s staining, and biochemical reactions. Antimicrobial
susceptibility of the isolates was determined against various
antimicrobial agents (Hi – Media Mumbai India) by Kirby Bauer
DISK diffusion method on Muller Hinton agar plates. Maximum patients were in the age group of 21-30 yrs followed by
31-40 yrs. Males (34%) are less prone to urinary tract infections than
females (66%). Culture was positive in 25% of the samples.
Escherichia coli was the most common isolate 60.3% followed by
Klebsiella pneumoniae 13.5%, Proteus spp. 9% and Staphylococcus
aureus 7.6%. Most of the urinary isolates were sensitive to,
carbepenems, Aztreonam, Amikacin, and Piperacillin + Tazobactum.
All the isolates showed a good sensitivity towards Nitrofurantoin
(82%). ESBL production was found to be 70.6% in Escherichia coli
and 29.4% in Klebsiella pneumonia. Susceptibility of ESBL
producers to Imipenem, Nitrofurantoin and Amikacin were found to
be 100%, 76%, and 75% respectively. Uropathogens are increasingly
showing resistance to many antibiotics making empiric management
of outpatient UTIs challenging. Ampicillin, Cotrimoxazole and
Ciprofloxacin should not be used in empiric treatment. Nitrofurantoin
could be used in lower urinary tract infection. Knowledge of
uropathogens and their antimicrobial susceptibility pattern in a
geographical region will help in appropriate and judicious antibiotic
usage in a health care setup.
Abstract: In this paper, we present a comparative study of three
methods of 2D face recognition system such as: Iso-Geodesic Curves
(IGC), Geodesic Distance (GD) and Geodesic-Intensity Histogram
(GIH). These approaches are based on computing of geodesic
distance between points of facial surface and between facial curves.
In this study we represented the image at gray level as a 2D surface in
a 3D space, with the third coordinate proportional to the intensity
values of pixels. In the classifying step, we use: Neural Networks
(NN), K-Nearest Neighbor (KNN) and Support Vector Machines
(SVM). The images used in our experiments are from two wellknown
databases of face images ORL and YaleB. ORL data base was
used to evaluate the performance of methods under conditions where
the pose and sample size are varied, and the database YaleB was used
to examine the performance of the systems when the facial
expressions and lighting are varied.
Abstract: This paper aims to determine Fundamental Natural
Frequency (FNF) of a structural composite floor system known as
Chromite. To achieve this purpose, FNFs of studied panels are
determined by development of Finite Element Models (FEMs) in
ABAQUS program. American Institute of Steel Construction (AISC)
code in Steel Design Guide Series 11 presents a fundamental formula
to calculate FNF of a steel framed floor system. This formula has
been used to verify results of the FEMs. The variability in the FNF of
the studied system under various parameters such as dimensions of
floor, boundary conditions, rigidity of main and secondary beams
around the floor, thickness of concrete slab, height of composite
joists, distance between composite joists, thickness of top and bottom
flanges of the open web steel joists, and adding tie beam
perpendicular on the composite joists, is determined. The results
show that changing in dimensions of the system, its boundary
conditions, rigidity of main beam, and also adding tie beam,
significant changes the FNF of the system up to 452.9%, 50.8%, -
52.2%, %52.6%, respectively. In addition, increasing thickness of
concrete slab increases the FNF of the system up to 10.8%.
Furthermore, the results demonstrate that variation in rigidity of
secondary beam, height of composite joist, and distance between
composite joists, and thickness of top and bottom flanges of open
web steel joists insignificant changes the FNF of the studied system
up to -0.02%, -3%, -6.1%, and 0.96%, respectively. Finally, the
results of this study help designer predict occurrence of resonance,
comfortableness, and design criteria of the studied system.
Abstract: The effect of molybdate addition to chloride
environment on resistance of AISI 316Ti stainless steel to pitting
corrosion was studied. Potentiodynamic polarisation tests were
performed in 1 M and 0.1 M chloride acidified solutions with various
additions of sodium molybdate at room temperature. The presented
results compare the effect of molybdate anions on quality of passive
film (expressed by the pitting potential) in both chloride solutions.
The pitting potential increases with the increase inhibitor
concentration. The inhibitive effect of molybdate ions is stronger in
chloride solution of lower aggressiveness (0.1M).
Abstract: Ocean current is always available around the
surrounding of SHELL Sabah Water Platform and data are collected
every 10 minutes, 24 hours a day, for a period of 365 days. Due to
low current speed, conventional hydrokinetic power generation is not
feasible, thus leading to the study of low current enabled vortex
induced vibration power generation application. In this case, the
design of a vortex induced vibration application is studied to obtain
an optimum design for the VIV oscillator. Power output is then
determined to study the feasibility of the VIV application in low
current condition.
Abstract: This paper presents comparative analysis of
photovoltaic systems (PVS) and propose practical techniques to
improve operational efficiency of the PVS. The best engineering and
construction practices for PVS are identified and field oriented
recommendation are made. Comparative analysis of central and
string inverter based, as well as 600 and 1000VDC PVS are
performed. In addition, direct current (DC) and alternating current
(AC) photovoltaic (PV) module based systems are compared.
Comparison shows that 1000V DC String Inverters based PVS is the
best choice.
Abstract: New and more powerful communications technologies
continue to emerge at a rapid pace and their uses in education are
widespread and the impact remarkable in the developing societies.
This study investigates Mobile Collaboration Learning Technique
(MCLT) on learners’ outcome among students in tertiary institutions
of developing nations (a case of Nigeria students). It examines the
significance of retention achievement scores of students taught using
mobile collaboration and conventional method. The sample consisted
of 120 students using Stratified random sampling method. Five
research questions and hypotheses were formulated, and tested at
0.05 level of significance. A student achievement test (SAT) was
made of 40 items of multiple-choice objective type, developed and
validated for data collection by professionals. The SAT was
administered to students as pre-test and post-test. The data were
analyzed using t-test statistic to test the hypotheses. The result
indicated that students taught using MCLT performed significantly
better than their counterparts using the conventional method of
instruction. Also, there was no significant difference in the post-test
performance scores of male and female students taught using MCLT.
Based on the findings, the following submissions was made that:
Mobile collaboration system be encouraged in the institutions to
boost knowledge sharing among learners, workshop and training
should be organized to train teachers on the use of this technique,
schools and government should consistently align curriculum
standard to trends of technological dictates and formulate policies
and procedures towards responsible use of MCLT.
Abstract: Asphalt concrete pavements have a short life cycle,
failing mainly due to temperature changes, traffic loading and ageing.
Modified asphalt mixtures provide the technology to produce a
bituminous binder with improved viscoelastic properties, which
remain in balance over a wider temperature range and loading
conditions. In this research, 60/70 penetration grade asphalt binder
was modified by adding 2, 4, 6, 8 and 10 percent by weight of asphalt
binder following the wet process and the mineral aggregate was
modified by adding 1, 2, 3, 4 and 5 percent crumb rubber by volume
of the mineral aggregate following the dry process. The LDPE
modified asphalt binder rheological properties were evaluated. The
laboratory results showed an increase in viscosity, softening point
and stiffness of the binder. The modified asphalt was then used in
preparing asphalt mixtures by Marshall Mix design procedure. The
Marshall Stability values for mixes containing 2% crumb rubber and
4% LDPE were found to be 30% higher than the conventional asphalt
concrete mix.
Abstract: Carbon nanotubes (CNTs) are known for having high elastic properties with high surface area that promote them as good candidates for reinforcing polymeric matrices. In composite materials, CNTs lack chemical bonding with the surrounding matrix which decreases the possibility of better stress transfer between the components. In this work, a chemical treatment for activating the surface of the multi-wall carbon nanotubes (MWCNT) was applied and the effect of this functionalization on the elastic properties of the epoxy nanocomposites was studied. Functional amino-groups were added to the surface of the CNTs and it was evaluated to be about 34% of the total weight of the CNTs. Elastic modulus was found to increase by about 40% of the neat epoxy resin at CNTs’ weight fraction of 0.5%. The elastic modulus was found to decrease after reaching a certain concentration of CNTs which was found to be 1% wt. The scanning electron microscopic pictures showed the effect of the CNTs on the crack propagation through the sample by forming stress concentrated spots at the nanocomposite samples.
Abstract: The work reported through this paper is an
experimental work conducted on High Performance Concrete (HPC)
with super plasticizer with the aim to develop some models suitable
for prediction of compressive strength of HPC mixes. In this study,
the effect of varying proportions of fly ash (0% to 50% @ 10%
increment) on compressive strength of high performance concrete has
been evaluated. The mix designs studied were M30, M40 and M50 to
compare the effect of fly ash addition on the properties of these
concrete mixes. In all eighteen concrete mixes that have been
designed, three were conventional concretes for three grades under
discussion and fifteen were HPC with fly ash with varying
percentages of fly ash. The concrete mix designing has been done in
accordance with Indian standard recommended guidelines. All the
concrete mixes have been studied in terms of compressive strength at
7 days, 28 days, 90 days, and 365 days. All the materials used have
been kept same throughout the study to get a perfect comparison of
values of results. The models for compressive strength prediction
have been developed using Linear Regression method (LR), Artificial
Neural Network (ANN) and Leave-One-Out Validation (LOOV)
methods.
Abstract: The current-voltage (I-V) characteristics of Pd/n-GaN Schottky barrier were studied at temperatures over room temperature (300-470K). The values of ideality factor (n), zero-bias barrier height (φB0), flat barrier height (φBF) and series resistance (Rs) obtained from I-V-T measurements were found to be strongly temperature dependent while (φBo) increase, (n), (φBF) and (Rs) decrease with increasing temperature. The apparent Richardson constant was found to be 2.1x10-9 Acm-2K-2 and mean barrier height of 0.19 eV. After barrier height inhomogeneities correction, by assuming a Gaussian distribution (GD) of the barrier heights, the Richardson constant and the mean barrier height were obtained as 23 Acm-2K-2 and 1.78eV, respectively. The corrected Richardson constant was very closer to theoretical value of 26 Acm-2K-2.
Abstract: Radiative heat transfer in participating medium was
carried out using the finite volume method. The radiative transfer
equations are formulated for absorbing and anisotropically scattering
and emitting medium. The solution strategy is discussed and the
conditions for computational stability are conferred. The equations
have been solved for transient radiative medium and transient
radiation incorporated with transient conduction. Results have been
obtained for irradiation and corresponding heat fluxes for both the
cases. The solutions can be used to conclude incident energy and
surface heat flux. Transient solutions were obtained for a slab of heat
conducting in slab and by thermal radiation. The effect of heat
conduction during the transient phase is to partially equalize the
internal temperature distribution. The solution procedure provides
accurate temperature distributions in these regions. A finite volume
procedure with variable space and time increments is used to solve
the transient radiation equation. The medium in the enclosure
absorbs, emits, and anisotropically scatters radiative energy. The
incident radiations and the radiative heat fluxes are presented in
graphical forms. The phase function anisotropy plays a significant
role in the radiation heat transfer when the boundary condition is
non-symmetric.
Abstract: Piezoelectric actuator is treated as RC load when it is
modeled electrically. For some piezoelectric actuator applications,
arbitrary voltage is required to actuate. Especially for unidirectional
arbitrary voltage driving like as sine wave, some special inverter with
circuit that can charge and discharge the capacitive energy can be
used. In this case, the difference between power supply level and the
object voltage level for RC load is varied. Because the control gain is
constant, the controlled output is not uniform according to the voltage
difference. In this paper, for charge and discharge circuit for
unidirectional arbitrary voltage driving for piezoelectric actuator, the
controller gain is controlled according to the voltage difference. With
the proposed simple idea, the load voltage can have controlled
smoothly although the voltage difference is varied. The
appropriateness is proved from the simulation of the proposed circuit.
Abstract: Lots of motors have been being used in industry.
Therefore many researchers have studied about the failure diagnosis of
motors. In this paper, the effect of measuring environment for
diagnosis of gear fault connected to a motor shaft is studied. The fault
diagnosis is executed through the comparison of normal gear and
abnormal gear. The measured FFT data are compared with the normal
data and analyzed for q-axis current, noise and vibration. For bad and
good environment, the diagnosis results are compared. From these, it
is shown that the bad measuring environment may not be able to detect
exactly the motor gear fault. Therefore it is emphasized that the
measuring environment should be carefully prepared.
Abstract: Health workforce is a fundamental component of
health system and plays a significant role in delivering effective
health care services. However, there is a crucial shortage of skilled
personnel which make them prone to work in stressful conditions. In
spite of excessively high workload and burnout among the staff, little
attention is given to their job satisfaction level which has serious
implications on the productivity and effective performance of staff to
achieve organizational goals. Therefore, this study aims to explore
the job satisfaction of midwives working in the labor ward of the
Lady Dufferin Hospital, Karachi. A cross-sectional survey was
conducted. The short version of Minnesota Job Satisfaction
Questionnaire was administered on a convenient sample group of 22
midwives to gather information on their job satisfaction. The results
demonstrated that midwives were overall satisfied with their job. The
level of job satisfaction was however found different in various
positions within midwifery cadre. The head of midwives was highly
satisfied as compared to midwifery staff who works under the
supervision of head. The level of satisfaction of team leaders fall
between the head and staff of midwifery. Similar trends were
observed for both intrinsic and extrinsic job satisfaction. Such
evidences on these issues are essential and useful as it helps explore
the attitudes of individuals towards work which has direct
implications on access to quality care services. Strategic interventions
are required at organizational level to provide motivators and
satisfiers to health workers for their work related satisfaction and
enhanced motivation.
Abstract: In this numerical work, mixed convection and entropy
generation of Cu–water nanofluid in a lid-driven square cavity have
been investigated numerically using the Lattice Boltzmann Method.
Horizontal walls of the cavity are adiabatic and vertical walls have
constant temperature but different values. The top wall has been
considered as moving from left to right at a constant speed, U0. The
effects of different parameters such as nanoparticle volume
concentration (0–0.05), Rayleigh number (104–106) and Reynolds
numbers (1, 10 and 100) on the entropy generation, flow and
temperature fields are studied. The results have shown that addition
of nanoparticles to the base fluid affects the entropy generation, flow
pattern and thermal behavior especially at higher Rayleigh and low
Reynolds numbers. For pure fluid as well as nanofluid, the increase
of Reynolds number increases the average Nusselt number and the
total entropy generation, linearly. The maximum entropy generation
occurs in nanofluid at low Rayleigh number and at high Reynolds
number. The minimum entropy generation occurs in pure fluid at low
Rayleigh and Reynolds numbers. Also at higher Reynolds number,
the effect of Cu nanoparticles on enhancement of heat transfer was
decreased because the effect of lid-driven cavity was increased. The
present results are validated by favorable comparisons with
previously published results. The results of the problem are presented
in graphical and tabular forms and discussed.
Abstract: Rapid population growth, urbanization and
industrialization are known as the most important factors of
environment problems. Elimination and management of solid wastes
are also within the most important environment problems. One of the
main problems in solid waste management is the selection of the best
site for elimination of solid wastes. Lately, Geographical Information
System (GIS) has been used for easing selection of landfill area. GIS
has the ability of imitating necessary economic, environmental and
political limitations. They play an important role for the site selection
of landfill area as a decision support tool. In this study; map layers will be studied for minimum effect of
environmental, social and cultural factors and maximum effect for
engineering/economic factors for site selection of landfill areas and
using GIS for a decision support mechanism in solid waste landfill
areas site selection will be presented in Aksaray/Turkey city,
Güzelyurt district practice.
Abstract: The consumption of food contaminated with molds
(microscopic filamentous fungi) and their toxic metabolites results in
the development of food-borne mycotoxicosis. The spores of molds
are ubiquitously spread in the environment and can be detected
everywhere. Ochratoxin A is a toxic and potentially carcinogenic
fungal toxin found in a variety of food commodities. In this study, the
mycological quality of various ready-to-eat local and imported pork
meat and meat byproducts sold in Egyptian markets were assessed
and the presence of various molds was determined in pork used as a
raw material, edible organs as liver and kidney as well as in
fermented raw meat by-products. The study assessed the mycological
quality of pork raw meat and their by-products sold in commercial
shops in Cairo, Egypt. Mycological analysis was conducted on
(n=110) samples which included pig’s livers and kidneys from
Egyptian Bassatin slaughter house; local and imported processed
pork meat by-products from Egyptian pork markets. The isolates
were identified using traditional mycological and biochemical tests.
All kidney and liver samples were positive to molds growth while all
byproducts were negative. Ochratoxin A levels were quantitatively
analyzed using the high performance liquid chromatography (HPLC)
and the highest results were present in kidney 7.51 part per billion
(ppb) followed by minced meat 6.19 ppb generally the local samples
showed higher levels than the imported ones. To the best of our
knowledge, this is the first report on mycotoxins detection and
quantification from pork by-products in Egypt.
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.