Abstract: Ocimum americanum L (Lamiaceae) is an annual herb
that is native to tropical Africa. The in vitro and in vivo antioxidant
activity of its aqueous extract was carefully investigated by assessing
the DPPH radical scavenging activity, ABTS radical scavenging
activity and hydrogen peroxide radical scavenging activity. The
reducing power, total phenol, total flavonoids and flavonols content
of the extract were also evaluated. The data obtained revealed that the
extract is rich in polyphenolic compounds and scavenged the radicals
in a concentration dependent manner. This was done in comparison
with the standard antioxidants such as BHT and Vitamin C. Also, the
induction of oxidative damage with paracetamol (2000 mg/kg)
resulted in the elevation of lipid peroxides and significant (P < 0.05)
decrease in activities of superoxide dismutase, glutathione
peroxidase, glutathione reductase and catalase in the liver and kidney
of rats. However, the pretreatment of rats with aqueous extract of O.
americanum leaves (200 and 400 mg/kg) and silymarin (100 mg/kg)
caused a significant (P < 0.05) reduction in the values of lipid
peroxides and restored the levels of antioxidant parameters in these
organs. These findings suggest that the leaves of O. americanum have
potent antioxidant properties which may be responsible for its
acclaimed folkloric uses.
Abstract: The present study was undertaken to investigate the
effect of aging parameters (time and temperature) on the mechanical
properties of Be-and/or Zr- treated Al-Mg-Zn (7075) alloys. Ultimate
tensile strength, 0.5% offset yield strength and % elongation
measurements were carried out on specimens prepared from cast and
heat treated 7075 alloys containing Be and/or Zr. Different aging
treatment were carried out for the as solution treated (SHT)
specimens (after quenching in warm water). The specimens were
aged at different conditions; Natural and artificial aging was carried
out at room temperature, 120C, 150C, 180C and 220C for different
periods of time. Duplex aging was performed for SHT conditions
(pre-aged at different time and temperature followed by high
temperature aging). Ultimate tensile strength, yield strength and %
elongation data results as a function of different aging parameters are
analysed. A statistical design of experiments (DOE) approach using
fractional factorial design is applied to acquire an understanding of
the effects of these variables and their interactions on the mechanical
properties of Be- and/or Zr- treated 7075 alloys. Mathematical
models are developed to relate the alloy mechanical properties with
the different aging parameters.
Abstract: This study concerned the dynamic behavior of the
wind turbine rotor. Before all we have studied the loads applied to the
rotor, which allows the knowledge their effect on the fatigue, also
studied the rotor with longitudinal crack in order to determine stress,
strain and displacement. Firstly we compared the first six modes
shapes between cracking and uncracking of HAWT rotor. Secondly
we show show evolution of first six natural frequencies with
longitudinal crack propagation. Finally we conclude that the residual
change in the natural frequencies can be used as in shaft crack
diagnosis predictive maintenance.
Abstract: Early detection of breast cancer saves many thousands
of lives each year via application of mammography and genetic
screening and many more lives could be saved if nurses are involved
in breast care screening practices. So, the aim of the study was to
identify nurse's role in early detection of breast cancer through
mammography and genetic screening and its impact on patient's
outcome. In order to achieve this aim, 400 women above 40 years,
asymptomatic were recruited for mammography and genetic
screening. In addition, 50 nurses and 6 technologists were involved in
the study. A descriptive analytical design was used. Five tools were
utilized: sociodemographic, mammographic examination and risk
factors, women's before, during and after mammography, items
relaying to technologists, and items related to nurses were also
obtained. The study finding revealed that 3% of women detected for
malignancy and 7.25% for fibroadenoma. Statistically significant
differences were found between mammography results and age,
family history, genetic screening, exposure to smoke, and using
contraceptive pills. Nurses have insufficient knowledge about
screening tests. Based on these findings the present study
recommended involvement of nurses in breast care which is very
important to in force population about screening practices.
Abstract: Numeracy, like Literacy is considered to be a core
value of modern societies. Most higher education institutions in
South Africa include being numerate as an important graduate
attribute. It is argued that a suitability numerate society contributes to
social justice, empowerment, financial and environmental
sustainability and a lack of numeracy practices can contribute to
disempowerment.
Numeracy is commonly misconstrued as a basic and simple
practice, similar in nature to basic arithmetic. This study highlights
the complexities of higher education numeracy practices by analyzing
a programme in a higher education institution in South Africa using
the New Literacies Studies perspective.
Abstract: The tombolo of Giens is located in the town of Hyères
(France). We recall the history of coastal erosion, and prominent
factors affecting the evolution of the western tombolo. We then
discuss the possibility of stabilizing the western tombolo. Our
argumentation relies on a coupled model integrating swells, currents,
water levels and sediment transport. We present the conclusions of
the simulations of various scenarios, including pre-existing
propositions from coastal engineering offices. We conclude that
beach replenishment seems to be necessary but not sufficient for the
stabilization of the beach. Breakwaters reveal effective particularly in
the most exposed northern area. Some solutions fulfill conditions so
as to be elected as satisfactory. We give a comparative analysis of the
efficiency of 14 alternatives for the protection of the tombolo.
Abstract: In this research the effects of adding silica and
alumina nanoparticles on flow ability and compressive strength of
cementitious composites based on Portland cement were investigated.
In the first stage, the rheological behavior of different samples
containing nanosilica, nanoalumina and polypropylene, polyvinyl
alcohol and polyethylene fibers were evaluated. With increasing of
nanoparticles in fresh samples, the slump flow diameter reduced.
Fibers reduced the flow ability of the samples and viscosity
increased. With increasing of the micro silica particles to cement
ratio from 2/1 to 2/2, the slump flow diameter increased. By adding
silica and alumina nanoparticles up to 3% and 2% respectively, the
compressive strength increased and after decreased. Samples
containing silica nanoparticles and fibers had the highest compressive
strength.
Abstract: The aim of this paper is to give an assessment of
environmental effects of IPPC permit conditions of installations that
are in specific territory with high concentration of industrial
activities.
The IPPC permit is the permit that each operator should hold to
operate the installation as stated by the directive 2010/75/UE on
industrial emissions (integrated pollution prevention and control),
known as IED (Industrial Emissions Directive).
The IPPC permit includes all the measures necessary to achieve a
high level of protection of the environment as a whole, also defining
the monitoring requirements as measurement methodology,
frequency and evaluation procedure. The emissions monitoring of a
specific plant may also give indications of the contribution of these
emissions on the air quality of a definite area.
So, it is clear that the IPPC permits are important tools both to
improve the environmental framework and to achieve the air quality
standards, assisting to assess the possible industrial sources
contributions to air pollution.
Abstract: In this paper we describe one critical research
program within a complex, ongoing multi-year project (2010 to 2014
inclusive) with the overall goal to improve the learning outcomes for
first year undergraduate commerce/business students within an
Information Systems (IS) subject with very large enrolment. The
single research program described in this paper is the analysis of
student attitudes and decision making in relation to the availability of
formative assessment feedback via Web-based real time conferencing
and document exchange software (Adobe Connect). The formative
assessment feedback between teaching staff and students is in respect
of an authentic problem-based, team-completed assignment. The
analysis of student attitudes and decision making is investigated via
both qualitative (firstly) and quantitative (secondly) application of the
Theory of Planned Behavior (TPB) with a two statistically-significant
and separate trial samples of the enrolled students. The initial
qualitative TPB investigation revealed that perceived self-efficacy,
improved time-management, and lecturer-student relationship
building were the major factors in shaping an overall favorable
student attitude to online feedback, whilst some students expressed
valid concerns with perceived control limitations identified within the
online feedback protocols. The subsequent quantitative TPB
investigation then confirmed that attitude towards usage, subjective
norms surrounding usage, and perceived behavioral control of usage
were all significant in shaping student intention to use the online
feedback protocol, with these three variables explaining 63 percent of
the variance in the behavioral intention to use the online feedback
protocol. The identification in this research of perceived behavioral
control as a significant determinant in student usage of a specific
technology component within a virtual learning environment (VLE)
suggests that VLEs could now be viewed not as a single, atomic
entity, but as a spectrum of technology offerings ranging from the
mature and simple (e.g., email, Web downloads) to the cutting-edge
and challenging (e.g., Web conferencing and real-time document
exchange). That is, that all VLEs should not be considered the same.
The results of this research suggest that tertiary students have the
technological sophistication to assess a VLE in this more selective
manner.
Abstract: This study is concerned with the optimization of
fermentation parameters for the hyper production of mannanase from
Fusarium oxysporum SS-25 employing two step statistical strategy
and kinetic characterization of crude enzyme preparation. The
Plackett-Burman design used to screen out the important factors in
the culture medium revealed 20% (w/w) wheat bran, 2% (w/w) each
of potato peels, soyabean meal and malt extract, 1% tryptone, 0.14%
NH4SO4, 0.2% KH2PO4, 0.0002% ZnSO4, 0.0005% FeSO4, 0.01%
MnSO4, 0.012% SDS, 0.03% NH4Cl, 0.1% NaNO3 in brewer’s spent
grain based medium with 50% moisture content, inoculated with
2.8×107 spores and incubated at 30oC for 6 days to be the main
parameters influencing the enzyme production. Of these factors, four
variables including soyabean meal, FeSO4, MnSO4 and NaNO3 were
chosen to study the interactive effects and their optimum levels in
central composite design of response surface methodology with the
final mannanase yield of 193 IU/gds. The kinetic characterization
revealed the crude enzyme to be active over broader temperature and
pH range. This could result in 26.6% reduction in kappa number with
4.93% higher tear index and 1% increase in brightness when used to
treat the wheat straw based kraft pulp. The hydrolytic potential of
enzyme was also demonstrated on both locust bean gum and guar
gum.
Abstract: The progress of industry integrated circuits in recent
years has been pushed by continuous miniaturization of transistors.
With the reduction of dimensions of components at 0.1 micron and
below, new physical effects come into play as the standard simulators
of two dimensions (2D) do not consider. In fact the third dimension
comes into play because the transverse and longitudinal dimensions
of the components are of the same order of magnitude. To describe
the operation of such components with greater fidelity, we must
refine simulation tools and adapted to take into account these
phenomena. After an analytical study of the static characteristics of
the component, according to the different operating modes, a
numerical simulation is performed of field-effect transistor with
submicron gate MESFET GaInP. The influence of the dimensions of
the gate length is studied. The results are used to determine the
optimal geometric and physical parameters of the component for their
specific applications and uses.
Abstract: Advanced head and neck cancers are aggressive
tumours, which require aggressive treatment. Treatment efficiency is
often hindered by cancer cell repopulation during radiotherapy,
which is due to various mechanisms triggered by the loss of tumour
cells and involves both stem and differentiated cells. The aim of the
current paper is to present in silico simulations of radiotherapy
schedules on a virtual head and neck tumour grown with biologically
realistic kinetic parameters. Using the linear quadratic formalism of
cell survival after radiotherapy, altered fractionation schedules
employing various treatment breaks for normal tissue recovery are
simulated and repopulation mechanism implemented in order to
evaluate the impact of various cancer cell contribution on tumour
behaviour during irradiation. The model has shown that the timing of
treatment breaks is an important factor influencing tumour control in
rapidly proliferating tissues such as squamous cell carcinomas of the
head and neck. Furthermore, not only stem cells but also
differentiated cells, via the mechanism of abortive division, can
contribute to malignant cell repopulation during treatment.
Abstract: Different tools and technologies were implemented
for Crisis Response and Management (CRM) which is generally
using available network infrastructure for information exchange.
Depending on type of disaster or crisis, network infrastructure could
be affected and it could not be able to provide reliable connectivity.
Thus any tool or technology that depends on the connectivity could
not be able to fulfill its functionalities. As a solution, a new message
exchange framework has been developed. Framework provides
offline/online information exchange platform for CRM Information
Systems (CRMIS) and it uses XML compression and packet
prioritization algorithms and is based on open source web
technologies. By introducing offline capabilities to the web
technologies, framework will be able to perform message exchange
on unreliable networks. The experiments done on the simulation
environment provide promising results on low bandwidth networks
(56kbps and 28.8 kbps) with up to 50% packet loss and the solution is
to successfully transfer all the information on these low quality
networks where the traditional 2 and 3 tier applications failed.
Abstract: Bio-composites derived from plant fiber and/or bioderived
polymer, are likely more ecofriendly and demonstrate
competitive performance with petroleum based composites. In this
research, the bio phenol-formaldehyde (bio-PF) was used as a matrix
and oil palm empty fruit bunch fiber (EFB) as reinforcement. The
matrix was synthesized via liquefaction and condensation to enhance
the combination of phenol and formaldehyde, during the process.
Then, the bio-PF was mixed with different percentage of EFB (5%,
10%, 15% and 20%) and molded at 180oC. The samples that viewed
under scanning electron microscopy (SEM) showed an excellent
wettability and interaction between EFB and matrix. Samples of 10%
EFB gave the optimum properties of impact and hardness meanwhile
sample 15% of EFB gave the highest reading of flexural modulus
(MOE) and flexural strength (MOR). For thermal stability analysis, it
was found that the weight loss and the activation energy (Ea) of the
bio-composites samples were decreased as the filler content
increased.
Abstract: Exact solution of an unsteady flow of elastico-viscous
fluid through a porous media in a tube of spherical cross section
under the influence of constant pressure gradient has been obtained in
this paper. Initially, the flow is generated by a constant pressure
gradient. After attaining the steady state, the pressure gradient is
suddenly withdrawn and the resulting fluid motion in a tube of
spherical cross section by taking into account of the porosity factor of
the bounding surface is investigated. The problem is solved in twostages
the first stage is a steady motion in tube under the influence of
a constant pressure gradient, the second stage concern with an
unsteady motion. The problem is solved employing separation of
variables technique. The results are expressed in terms of a nondimensional
porosity parameter (K) and elastico-viscosity parameter
(β), which depends on the Non-Newtonian coefficient. The flow
parameters are found to be identical with that of Newtonian case as
elastic-viscosity parameter tends to zero and porosity tends to
infinity. It is seen that the effect of elastico-viscosity parameter,
porosity parameter of the bounding surface has significant effect on
the velocity parameter.
Abstract: The research presented in this paper has been focused
on analysing the impact of traffic on the sustainable development of
tourism in Croatia's Dubrovacko-Neretvanska County by the year
2020, based on the figures and trends reported in 2014 and using the
relevant variables that characterise the synergy of traffic and tourism
in, speaking from the geographic viewpoint, the most problematic
county in the Republic of Croatia. The basic hypothesis has been
confirmed through scientifically obtained research results, through
the quantification of the model's variables and the direct growth rates
of the designed model. On the basis of scientific insights into the
sustainable development of traffic and tourism in Dubrovacko-
Neretvanska County, it is possible to propose a new information
model for traffic at the service of the sustainable development of
tourism in the County for the period 2014-2020.
Abstract: Vegetation affects the mean and turbulent flow
structure. It may increase flood risks and sediment transport.
Therefore, it is important to develop analytical approaches for the bed
shear stress on vegetated bed, to predict resistance caused by
vegetation. In the recent years, experimental and numerical models
have both been developed to model the effects of submerged
vegetation on open-channel flow. In this paper, different analytic
models are compared and tested using the criteria of deviation, to
explore their capacity for predicting the mean velocity and select the
suitable one that will be applied in real case of rivers. The
comparison between the measured data in vegetated flume and
simulated mean velocities indicated, a good performance, in the case
of rigid vegetation, whereas, Huthoff model shows the best
agreement with a high coefficient of determination (R2=80%) and the
smallest error in the prediction of the average velocities.
Abstract: This paper presents the details of a numerical study of
buckling and post buckling behaviour of laminated carbon fiber
reinforced plastic (CFRP) thin-walled cylindrical shell under axial
compression using asymmetric meshing technique (AMT) by
ABAQUS. AMT is considered to be a new perturbation method to
introduce disturbance without changing geometry, boundary
conditions or loading conditions. Asymmetric meshing affects both
predicted buckling load and buckling mode shapes. Cylindrical shell
having lay-up orientation [0^o/+45^o/-45^o/0^o] with radius to thickness
ratio (R/t) equal to 265 and length to radius ratio (L/R) equal to 1.5 is
analysed numerically. A series of numerical simulations
(experiments) are carried out with symmetric and asymmetric
meshing to study the effect of asymmetric meshing on predicted
buckling behaviour. Asymmetric meshing technique is employed in
both axial direction and circumferential direction separately using
two different methods, first by changing the shell element size and
varying the total number elements, and second by varying the shell
element size and keeping total number of elements constant. The
results of linear analysis (Eigenvalue analysis) and non-linear
analysis (Riks analysis) using symmetric meshing agree well with
analytical results. The results of numerical analysis are presented in
form of non-dimensional load factor, which is the ratio of buckling
load using asymmetric meshing technique to buckling load using
symmetric meshing technique. Using AMT, load factor has about 2%
variation for linear eigenvalue analysis and about 2% variation for
non-linear Riks analysis. The behaviour of load end-shortening curve
for pre-buckling is same for both symmetric and asymmetric meshing
but for asymmetric meshing curve behaviour in post-buckling
becomes extraordinarily complex. The major conclusions are:
different methods of AMT have small influence on predicted
buckling load and significant influence on load displacement curve
behaviour in post buckling; AMT in axial direction and AMT in
circumferential direction have different influence on buckling load
and load displacement curve in post-buckling.
Abstract: The present work aims to throw light on the effects of
arcing in air on the surface state of contact pastilles made of silvernickel
Ag-Ni (60/40). Also, the photoelectric emission from these
electrical contacts has been investigated in the spectral range of 196-
256 nm. In order to study the effects of arcing on the EWF, the
metallic samples were subjected to electrical arcs in air, at
atmospheric pressure and room temperature, after that, they have
been introduced into the vacuum chamber of an experimental UHV
set-up for EWF measurements. Both Fowler method of isothermal
curves and linearized Fowler plots were used for the measurement of
the EWF by the photoelectric effect.
It has been found that the EWF varies with the number of applied
arcs. Thus, after 500 arcs in air, the observed EWF increasing is
probably due to progressive inclusion of oxide on alloy surface.
Microscopic examination is necessary to get better understandings on
EWF of silver alloys, for both virgin and arced electrical contacts.
Abstract: Background: With the perceived pain and poor
function experienced following knee arthroplasty, patients usually
feel un-satisfied. Yet, a controversy still persists on the appropriate
operative technique that doesn’t affect proprioception much.
Purpose: This study compared the effects of Cruciate Retaining
(CR) and Posterior Stabilized (PS) total knee arthroplasty (TKA on
dynamic balance, pain and functional performance following
rehabilitation.
Methods: Thirty patients with CRTKA (group I), thirty with
PSTKA (group II) and fifteen indicated for arthroplasty but weren’t
operated on yet (group III) participated in the study. The mean age
was 54.53±3.44, 55.13±3.48 and 55.33±2.32 years and BMI
35.7±3.03, 35.7±1.99 and 35.73±1.03 kg/m2 for groups I, II and III
respectively. The Berg Balance Scale (BBS), WOMAC pain subscale
and Timed Up-and-Go (TUG) and Stair-Climbing (SC) tests were
used for assessment. Assessments were conducted four weeks preand
post-operatively, three, six and twelve months post-operatively
with the control group being assessed at the same time intervals. The
post-operative rehabilitation involved hospitalization (1st week),
home-based (2nd-4th weeks), and outpatient clinic (5th-12th weeks)
programs, follow-up to all groups for twelve months.
Results: The Mixed design MANOVA revealed that group I had
significantly lower pain scores and SC time compared with group II
three, six and twelve months post-operatively. Moreover, the BBS
scores increased significantly and the pain scores and TUG and SC
time decreased significantly six months post-operatively compared
with four weeks pre- and post-operatively and three months postoperatively
in groups I and II with the opposite being true four weeks
post-operatively. But no significant differences in BBS scores, pain
scores and TUG and SC time between six and twelve months postoperatively
in groups I and II.
Interpretation/Conclusion: CRTKA is preferable to PSTKA,
possibly due to the preserved human proprioceptors in the un-excised
PCL.