Abstract: Experimental study of natural convection heat transfer
inside smooth and rough surfaces of vertical and inclined equilateral
triangular channels of different inclination angles with a uniformly
heated surface are performed. The inclination angle is changed from
15º to 90º. Smooth and rough surface of average roughness (0.02mm)
are used and their effect on the heat transfer characteristics are
studied. The local and average heat transfer coefficients and Nusselt
number are obtained for smooth and rough channels at different heat
flux values, different inclination angles and different Rayleigh
numbers (Ra) 6.48 × 105 ≤ Ra ≤ 4.78 × 106. The results show that
the local Nusselt number decreases with increase of axial distance
from the lower end of the triangular channel to a point near the upper
end of channel, and then, it slightly increases. Higher values of local
Nusselt number for rough channel along the axial distance compared
with the smooth channel. The average Nusselt number of rough
channel is higher than that of smooth channel by about 8.1% for
inclined case at θ = 45o and 10% for vertical case. The results
obtained are correlated using dimensionless groups for both rough
and smooth surfaces of the inclined and vertical triangular channels.
Abstract: In the current work, a three-dimensional geometry of a
75% stenosed blood vessel is analyzed. Large eddy simulation (LES)
with the help of a dynamic subgrid scale Smagorinsky model is
applied to model the turbulent pulsatile flow. The geometry, the
transmural pressure and the properties of the blood and the elastic
boundary were based on clinical measurement data. For the flexible
wall model, a thin solid region is constructed around the 75%
stenosed blood vessel. The deformation of this solid region was
modelled as a deforming boundary to reduce the computational cost
of the solid model. Fluid-structure interaction is realized via a twoway
coupling between the blood flow modelled via LES and the
deforming vessel. The information of the flow pressure and the wall
motion was exchanged continually during the cycle by an arbitrary
Lagrangian-Eulerian method. The boundary condition of current time
step depended on previous solutions. The fluctuation of the velocity
in the post-stenotic region was analyzed in the study. The axial
velocity at normalized position Z=0.5 shows a negative value near
the vessel wall. The displacement of the elastic boundary was
concerned in this study. In particular, the wall displacement at the
systole and the diastole were compared. The negative displacement at
the stenosis indicates a collapse at the maximum velocity and the
deceleration phase.
Abstract: Background - The TrendCare Patient Dependency
System is currently used by a large number of maternity Services
across Australia, New Zealand and Singapore. In 2012, 2013 and
2014 validation studies were initiated in all three countries to validate
the acuity tools used for women in labour, and postnatal mothers and
babies. This paper will present the findings of the validation study.
Aim - The aim of this study was to; identify if the care hours
provided by the TrendCare acuity system was an accurate reflection
of the care required by women and babies; obtain evidence of
changes required to acuity indicators and/or category timings to
ensure the TrendCare acuity system remains reliable and valid across
a range of maternity care models in three countries.
Method - A non-experimental action research methodology was
used across maternity services in four District Health Boards in New
Zealand, a large tertiary and a large secondary maternity service in
Singapore and a large public maternity service in Australia.
Standardised data collection forms and timing devices were used to
collect midwife contact times, with women and babies included in the
study. Rejection processes excluded samples when care was not
completed/rationed, and contact timing forms were incomplete. The
variances between actual timed midwife/mother/baby contact and the
TrendCare acuity category times were identified and investigated.
Results - Thirty two (88.9%) of the 36 TrendCare acuity category
timings, fell within the variance tolerance levels when compared to
the actual timings recorded for midwifery care. Four (11.1%)
TrendCare categories provided less minutes of care than the actual
timings and exceeded the variance tolerance level. These were all
night shift category timings. Nine postnatal categories were not able
to be compared as the sample size for these categories was
statistically insignificant. 100% of labour ward TrendCare categories
matched actual timings for midwifery care, all falling within the
variance tolerance levels.
The actual time provided by core midwifery staff to assist lead
maternity carer (LMC) midwives in New Zealand labour wards
showed a significant deviation to previous studies. The findings of
the study demonstrated the need for additional time allocations in
TrendCare to accommodate an increased level of assistance given to
LMC midwives.
Conclusion - The results demonstrated the importance of regularly
validating the TrendCare category timings with actual timings of the
care hours provided. It was evident from the findings that variances
to models of care and length of stay in maternity units have increased
midwifery workloads on the night shift. The level of assistance
provided by the core labour ward staff to the LMC midwife has
increased substantially.
Outcomes - As a consequence of this study, changes were made to
the night duty TrendCare maternity categories, additional acuity
indicators were developed and times for assisting LMC midwives in
labour ward increased. The updated TrendCare version was delivered
to maternity services in 2014.
Abstract: Employer branding is considered as a useful tool for
addressing the global-local problem facing complex organisations
that have operations scattered across the globe and face challenges of
dealing with the local environment alongside. Despite being an
established field of study within the Western developed world, there
is little empirical evidence concerning the relevance of employer
branding to global companies that operate in the under-developed
economies. This paper fills this gap by gaining rich insight into the
implementation of employer branding programs in a foreign
multinational operating in Pakistan dealing with the global-local
problem. The study is qualitative in nature and employs semistructured
and focus group interviews with senior/middle managers
and local frontline employees to deeply examine the phenomenon in
case organisation. Findings suggest that authenticity is required in
employer brands to enable them to respond to the local needs thereby
leading to the resolution of the global-local problem. However, the
role of signaling theory is key to the development of authentic
employer brands as it stresses on the need to establish an efficient and
effective signaling environment where in signals travel in both
directions (from signal designers to receivers and backwards) and
facilitate firms with the global-local problem. The paper also
identifies future avenues of research for the employer branding field.
Abstract: This article presents modeling studies of NiAl alloy
under solid-particle erosion and liquid-drop erosion. In the
solid-particle erosion simulation, attention is paid to the oxide scale
thickness variation on the alloy in high-temperature erosion
environments. The erosion damage is assumed to be deformation wear
and cutting wear mechanisms, incorporating the influence of the oxide
scale on the eroded surface; thus the instantaneous oxide thickness is
the result of synergetic effect of erosion and oxidation. For liquid-drop
erosion, special interest is in investigating the effects of drop velocity
and drop size on the damage of the target surface. The models of
impact stress wave, mean depth of penetration, and maximum depth of
erosion rate (Max DER) are employed to develop various maps for
NiAl alloy, including target thickness vs. drop size (diameter), rate of
mean depth of penetration (MDRP) vs. drop impact velocity, and
damage threshold velocity (DTV) vs. drop size.
Abstract: Air-cooled Blast Furnace Slag Aggregate (BFSA) is
usually referred to as a material providing for unique properties of
concrete. On the other hand, negative influences are also presented in
many aspects. The freeze-thaw resistance of concrete is dependent on
many factors, including regional specifics and when a concrete mix is
specified it is still difficult to tell its exact freeze-thaw resistance due
to the different components affecting it. An important consideration
in working with BFSA is the granularity and whether slag is sorted or
not. The experimental part of the article represents a comparative
testing of concrete using both the sorted and unsorted BFSA through
the freeze-thaw resistance as an indicator of durability. Unsorted
BFSA is able to be successfully used for concretes as they are
specified for exposure class XF4 with providing that the type of
cement is precisely selected.
Abstract: In general, classical methods such as maximum
likelihood (ML) and least squares (LS) estimation methods are used
to estimate the shape parameters of the Burr XII distribution.
However, these estimators are very sensitive to the outliers. To
overcome this problem we propose alternative robust estimators
based on the M-estimation method for the shape parameters of the
Burr XII distribution. We provide a small simulation study and a real
data example to illustrate the performance of the proposed estimators
over the ML and the LS estimators. The simulation results show that
the proposed robust estimators generally outperform the classical
estimators in terms of bias and root mean square errors when there
are outliers in data.
Abstract: In general, codes and regulations consider seismic
loads only for completed structures of the bridges while, evaluation
of incomplete structure of bridges, especially those constructed by
free cantilever method, under these loads is also of great importance.
Hence, this research tried to study the behavior of incomplete
structure of common bridge type (box girder bridge), in construction
phase under vertical seismic loads. Subsequently, the paper provided
suitable guidelines and solutions to resist this destructive
phenomenon. Research results proved that use of preventive methods
can significantly reduce the stresses resulted from vertical seismic
loads in box cross sections to an acceptable range recommended by
design codes.
Abstract: This paper presents a study of SIW circuits (Substrate
Integrated Waveguide) with a rigorous and fast original approach
based on Iterative process (WCIP). The theoretical suggested study is
validated by the simulation of two different examples of SIW
circuits. The obtained results are in good agreement with those of
measurement and with software HFSS.
Abstract: This paper presents effects of distilled water, seawater
and sustained bending strains of 30% and 50% ultimate strain at
room temperature, on the durability of unidirectional pultruded
carbon fiber reinforced polymer (CFRP) plates. In this study,
dynamic mechanical analyzer (DMA) was used to investigate the
synergic effects of the immersions and bending strains on the viscoelastic
properties of (CFRP) such as storage modulus, tan delta and
glass transition temperature. The study reveals that the storage
modulus and glass transition temperature increase while tan delta
peak decreases in the initial stage of both immersions due to the
progression of curing. The storage modulus and Tg subsequently
decrease and tan delta increases due to the matrix plasticization. The
blister induced damages in the unstrained seawater samples enhance
water uptake and cause more serious degradation of Tg and storage
modulus than in water immersion. Increasing sustained bending
decreases Tg and storage modulus in a long run for both immersions
due to resin matrix cracking and debonding. The combined effects of
immersions and strains are not clearly reflected due to the statistical
effects of DMA sample sizes and competing processes of molecular
reorientation and postcuring.
Abstract: It is well known that in recent years magnetic
materials have received increased attention due to their properties.
For this reason a significant number of patents that were published
during the last decade are oriented towards synthesis and study of
such materials. The aim of this work is to create and study ferrite
nanocrystalline materials with spinel structure, using sol-gel
technology with participation of auto-combustion. This method is
perspective in that it is a cheap and low-temperature technique that
allows for the fine control on the product’s chemical composition.
Abstract: The paper discusses mineral water consumer market
and development policy in Georgia, the tools and measures, which
will contribute to production of mineral waters and increase its
export.
The paper studies and analyses current situation in mineral water
production sector as well as the factors affecting increase and
reduction of its export. It’s noted that in order to gain and maintain
competitive advantage, it’s necessary to provide continuous supply of
high quality goods with modern design, open new distribution
channels to enter new markets, carry out broad promotional activities,
organize e-commerce. Economic policy plays an important role in
protecting markets from counterfeit goods. The state also plays an
important role in attracting foreign direct investments. Stable
business environment and export oriented strategy is the basis for the
country’s economic growth.
Based on the research, the paper suggests the strategy for
improving competitiveness of Georgian mineral waters; relevant
conclusions and recommendations are provided.
Abstract: In this study, polycaprolactone (PCL) was dissolved
in chloroform:ethanol solvent system at a concentration of 18 w/v %.
1, 2, 4, and 6 droplets of formic acid were added to the prepared 10ml
PCL-chloroform:ethanol solutions separately. Fibrous webs were
produced by electrospinning technique based on the horizontal
working principle. Morphology of the webs was investigated by
using scanning electron microscopy (SEM) whereas fiber diameters
were measured by Image J Software System. The effect of formic
acid addition to the mostly used chloroform solvent on fiber
morphology was examined.
Results indicate that there is a distinct fall in fiber diameter with
the addition of formic acid drops. The average fiber diameter was
measured as 2.22μm in PCL /chloroform:ethanol solution system. On
the other hand, 328nm and 256 nm average fiber diameters were
measured for the samples of 4 drops and 6 drops formic acid added.
This study offers alternative solvent systems to produce nanoscaled,
nontoxic PCL fibrous webs by electrospinning technique.
Abstract: Freshly laid eggs from green turtles, Chelonia mydas,
were randomly collected from Ras Al-Hadd Reserve, Oman.
Eggshells taken from eggs and sand collected from the body chamber
were analyzed for eight heavy metals (Al, Br, Cd, Co, Cu, Fe, S, and
Zn) using inductively coupled plasma mass spectrometry (ICP).
Heavy metal concentrations varied significantly (P
Abstract: The objective of this work is to study the effect of two
key factors - external magnetic field and applied current density
during template-based electrodeposition of nickel nanowires using an
electrode distance of 20 mm. Morphology, length, crystallite size and
crystallographic characterization of the grown nickel nanowires at an
electrode distance of 20mm are presented. For this electrode distance
of 20 mm, these two key electrodeposition factors when coupled was
found to reduce crystallite size with a higher growth length and
preferred orientation of Ni crystals. These observed changes can be
inferred to be due to coupled interaction forces induced by the
intensity of applied electric field (current density) and external
magnetic field known as magnetohydrodynamic (MHD) effect during
the electrodeposition process.
Abstract: This study was conducted Razakı grape variety (Vitis
vinifera L.) and its vine which was aged 19 was grown on 5 BB
rootstock in a vegetation period of 2014 in Afyon province in Turkey.
In this research, it was investigated whether the applications of
Control (C), 1/3 Cluster Tip Reduction (1/3 CTR), Shoot Tip
Reduction (STR), 1/3 CTR + STR, Boric Acid (BA), 1/3 CTR + BA,
STR + BA, 1/3 CTR + STR + BA on yield and yield components of
Razakı grape variety. The results were obtained as the highest fresh
grape yield (7.74 kg/vine) with C application; as the highest cluster
weight (244.62 g) with STR application; as the highest 100 berry
weight (504.08 g) with C application; as the highest maturity index
(36.89) with BA application; as the highest must yield (695.00 ml)
with BA and (695.00 ml) with 1/3 CTR + STR + BA applications; as
the highest intensity of L* color (46.93) with STR and (46.10) with
1/3 CTR + STR + BA applications; as the highest intensity of a*
color (-5.37) with 1/3 CTR + STR and (-5.01) with STR, as the
highest intensity of b* color (12.59) with STR application. The shoot
tip reduction to increase cluster weight and boric acid application to
increase maturity index of Razakı grape variety can be recommended.
Abstract: Phelipanche ramosa is the most damaging obligate
flowering parasitic weed on wide species of cultivated plants. The
semi-arid regions of the world are considered the main centers of this
parasitic plant that causes heavy infestation. This is due to its
production of high numbers of seeds (up to 200,000) that remain
viable for extended periods (up to 20 years). In this study, 13
treatments for the control of Phelipanche were carried out, which
included agronomic, chemical, and biological treatments and the use
of resistant plant methods. In 2014, a trial was performed at the
Department of Agriculture, Food and Environment, University of
Foggia (southern Italy), on processing tomato (cv ‘Docet’) grown in
pots filled with soil taken from a field that was heavily infested by P.
ramosa). The tomato seedlings were transplanted on May 8, 2014,
into a sandy-clay soil (USDA). A randomized block design with 3
replicates (pots) was adopted. During the growing cycle of the
tomato, at 70, 75, 81 and 88 days after transplantation, the number of
P. ramosa shoots emerged in each pot was determined. The tomato
fruit were harvested on August 8, 2014, and the quantitative and
qualitative parameters were determined. All of the data were
subjected to analysis of variance (ANOVA) using the JMP software
(SAS Institute Inc. Cary, NC, USA), and for comparisons of means
(Tukey's tests). The data show that each treatment studied did not
provide complete control against P. ramosa. However, the virulence
of the attacks was mitigated by some of the treatments tried: radicon
biostimulant, compost activated with Fusarium, mineral fertilizer
nitrogen, sulfur, enzone, and the resistant tomato genotype. It is
assumed that these effects can be improved by combining some of
these treatments with each other, especially for a gradual and
continuing reduction of the “seed bank” of the parasite in the soil.
Abstract: The hydrodynamics and heat transfer characteristics
of a vaporized elongated bubble in a rectangular microchannel have
been simulated based on Cahn-Hilliard phase-field method. In the
simulations, the initially nucleated bubble starts growing as it comes
in contact with superheated water. The growing shape of the bubble
compared well with the available experimental data in the literature.
Abstract: The paper deals with possibilities of interpretation of
iron ore reducibility tests. It presents a mathematical model
developed at Centre ENET, VŠB – Technical University of Ostrava,
Czech Republic for an evaluation of metallurgical material of blast
furnace feedstock such as iron ore, sinter or pellets. According to the
data from the test, the model predicts its usage in blast furnace
technology and its effects on production parameters of shaft
aggregate. At the beginning, the paper sums up the general concept
and experience in mathematical modelling of iron ore reduction. It
presents basic equation for the calculation and the main parts of the
developed model. In the experimental part, there is an example of
usage of the mathematical model. The paper describes the usage of
data for some predictive calculation. There are presented material,
method of carried test of iron ore reducibility. Then there are
graphically interpreted effects of used material on carbon
consumption, rate of direct reduction and the whole reduction
process.
Abstract: The problem of toughening in brittle materials
reinforced by fibers is complex, involving all of the mechanical
properties of fibers, matrix and the fiber/matrix interface, as well as
the geometry of the fiber. Development of new numerical methods
appropriate to toughening simulation and analysis is necessary. In
this work, we have performed simulations and analysis of toughening
in brittle matrix reinforced by randomly distributed fibers by means
of the discrete elements method. At first, we put forward a
mechanical model of toughening contributed by random fibers. Then
with a numerical program, we investigated the stress, damage and
bridging force in the composite material when a crack appeared in the
brittle matrix. From the results obtained, we conclude that: (i) fibers
of high strength and low elasticity modulus are beneficial to
toughening; (ii) fibers of relatively high elastic modulus compared to
the matrix may result in substantial matrix damage due to spalling
effect; (iii) employment of high-strength synthetic fibers is a good
option for toughening. We expect that the combination of the discrete
element method (DEM) with the finite element method (FEM) can
increase the versatility and efficiency of the software developed. The
present work can guide the design of ceramic composites of high
performance through the optimization of the parameters.