Abstract: The objective of the paper is a numerical study of heat
transfer between perforated metal plates and the surrounding air
flows. Different perforation structures can nowadays be found in
various industrial products. Besides improving the mechanical
properties, the perforations can intensify the heat transfer as well. The
heat transfer coefficient depends on a wide range of parameters such
as type of perforation, size, shape, flow properties of the surrounding
air etc. The paper was focused on three different perforation
structures which have been investigated from the point of the view of
the production in the previous studies. To determine the heat
coefficients and the Nusselt numbers, the numerical simulation
approach was adopted. The calculations were performed using the
OpenFOAM software. The three-dimensional, unstable, turbulent and
incompressible air flow around the perforated surface metal plate was
considered.
Abstract: The objective of this study was to synthesize and
characterize the poly(alkenoic acid)s with different molecular
structures, use these polymers to formulate a dental cement
restorative, and study the effect of molecular structures on reaction
kinetics, viscosity, and mechanical strengths of the formed polymers
and cement restoratives. In this study, poly(alkenoic acid)s with
different molecular structures were synthesized. The purified
polymers were formulated with commercial Fuji II LC glass fillers to
form the experimental cement restoratives. The reaction kinetics was
studied via 1HNMR spectroscopy. The formed restoratives were
evaluated using compressive strength, diametral tensile strength,
flexural strength, hardness and wear-resistance tests. Specimens were
conditioned in distilled water at 37oC for 24 h prior to testing. Fuji II
LC restorative was used as control. The results show that the higher
the arm number and initiator concentration, the faster the reaction
was. It was also found that the higher the arm number and branching
that the polymer had, the lower the viscosity of the polymer in water
and the lower the mechanical strengths of the formed restorative. The
experimental restoratives were 31-53% in compressive strength, 37-
55% in compressive modulus, 80-126% in diametral tensile strength,
76-94% in flexural strength, 4-21% in fracture toughness and 53-96%
in hardness higher than Fuji II LC. For wear test, the experimental
restoratives were only 5.4-13% of abrasive and 6.4-12% of attritional
wear depths of Fuji II LC in each wear cycle. The aging study also
showed that all the experimental restoratives increased their strength
continuously during 30 days, unlike Fuji II LC. It is concluded that
polymer molecular structures have significant and positive impact on
mechanical properties of dental cement restoratives.
Abstract: Temperature regulating system by gaseous nitrogen is
of importance to the space environment simulator, which keeps the
shrouds in the temperature range from -150°C to +150°C. Liquid
nitrogen spray equipment is one of the most critical parts in the
temperature regulating system by gaseous nitrogen. Y type jet
atomizer and internal mixing atomizer of the liquid nitrogen spray
equipment are studied in this paper, 2D/3D atomizer model was
established and grid division was conducted respectively by the
software of Catia and ICEM. Based on the above preparation,
numerical simulation on the spraying process of the atomizer by
FLUENT is performed. Using air and water as the medium,
comparison between the tests and numerical simulation was conducted
and the results of two ways match well. Hence, it can be conclude that
this atomizer model can be applied in the numerical simulation of
liquid nitrogen spray equipment.
Abstract: Cancer is still one of the serious diseases threatening
the lives of human beings. How to have an early diagnosis and
effective treatment for tumors is a very important issue. The animal
carcinoma model can provide a simulation tool for the studies of
pathogenesis, biological characteristics, and therapeutic effects.
Recently, drug delivery systems have been rapidly developed to
effectively improve the therapeutic effects. Liposome plays an
increasingly important role in clinical diagnosis and therapy for
delivering a pharmaceutic or contrast agent to the targeted sites.
Liposome can be absorbed and excreted by the human body, and is
well known that no harm to the human body. This study aimed to
compare the therapeutic effects between encapsulated (doxorubicin
liposomal, Lipodox) and un-encapsulated (doxorubicin, Dox)
anti-tumor drugs using magnetic resonance imaging (MRI).
Twenty-four New Zealand rabbits implanted with VX2 carcinoma at
left thighs were classified into three groups: control group (untreated),
Dox-treated group, and LipoDox-treated group, 8 rabbits for each
group. MRI scans were performed three days after tumor implantation.
A 1.5T GE Signa HDxt whole body MRI scanner with a high
resolution knee coil was used in this study. After a 3-plane localizer
scan was performed, three-dimensional (3D) fast spin echo (FSE)
T2-weighted Images (T2WI) was used for tumor volumetric
quantification. Afterwards, two-dimensional (2D) spoiled gradient
recalled echo (SPGR) dynamic contrast-enhanced (DCE) MRI was
used for tumor perfusion evaluation. DCE-MRI was designed to
acquire four baseline images, followed by contrast agent Gd-DOTA
injection through the ear vein of rabbit. A series of 32 images were
acquired to observe the signals change over time in the tumor and
muscle. The MRI scanning was scheduled on a weekly basis for a
period of four weeks to observe the tumor progression longitudinally.
The Dox and LipoDox treatments were prescribed 3 times in the first
week immediately after the first MRI scan; i.e. 3 days after VX2 tumor
implantation. ImageJ was used to quantitate tumor volume and time
course signal enhancement on DCE images. The changes of tumor size
showed that the growth of VX2 tumors was effectively inhibited for
both LipoDox-treated and Dox-treated groups. Furthermore, the tumor
volume of LipoDox-treated group was significantly lower than that of
Dox-treated group, which implies that LipoDox has better therapeutic effect than Dox. The signal intensity of LipoDox-treated group is
significantly lower than that of the other two groups, which implies
that targeted therapeutic drug remained in the tumor tissue. This study
provides a radiation-free and non-invasive MRI method for
therapeutic monitoring of targeted liposome on an animal tumor
model.
Abstract: Hypertension is a common condition causing cardio
and cerebrovascular complications. Portugal has one of the highest
mortality rates from stroke and a high prevalence of hypertension.
Systolic Blood Pressure (SBP) is an important risk factor for
cardiovascular events (myocardial infarction and stroke) and
premature mortality, particularly in the elderly population. The
present study aims to estimate the prevalence of hypertension in a
Portuguese population living in a coastal city and to identify some of
its determinants (namely gender, age, the body mass index and
physical activity frequency). A total of 91 adults who attended three pharmacies of a coastal
city in the center of Portugal, between May and August of 2013 were
evaluated. Attendants who reported to have diabetes or taking
antihypertensive drugs in the 2 previous weeks were excluded from
the study. Sociodemographic factors, BMI, habits of exercise and BP
were assessed. Hypertension was defined as blood pressure ≥140/90
mmHg. The majority of the studied population was constituted by women
(75.8%), with a mean age of 54.2±1.6 years old, married or living in
civil union and that had completed secondary school or had higher
education (40%). They presented a mean BMI of 26.2±4.76 Kg/m2.,
and were sedentary. The mean BP was 127.0±17.77mmHg- 74.69 ±
9.53. In this population we found 4.3% of people with hypertension
and 16.1% with normal high blood pressure. Men exhibit a tendency to present higher systolic blood pressure
values than women. Of all the factors considered, SBP values also
tended to be higher with age and higher BMI values.
Despite the fact that the mean values of SBP did not present values
higher than 140 mmHg we must be concerned because the studied
population is undiagnosed for hypertension. Although this is a preliminary study, it might be a prelude to the
upcoming research about the underlying factors responsible for the
occurrence of SBP.
Abstract: The steady flow of a second order fluid through
constricted tube with slip velocity at wall is modeled and analyzed
theoretically. The governing equations are simplified by implying no
slip in radial direction. Based on Karman Pohlhausen procedure
polynomial solution for axial velocity profile is presented.
Expressions for pressure gradient, shear stress, separation and
reattachment points, and radial velocity are also calculated. The
effect of slip and no slip velocity on magnitude velocity, shear stress,
and pressure gradient are discussed and depicted graphically. It is
noted that when Reynolds number increases magnitude velocity of
the fluid decreases in both slip and no slip conditions. It is also found
that the wall shear stress, separation, and reattachment points are
strongly affected by Reynolds number.
Abstract: Obturator Foramen is a specific structure in Pelvic
bone images and recognition of it is a new concept in medical image
processing. Moreover, segmentation of bone structures such as
Obturator Foramen plays an essential role for clinical research in
orthopedics. In this paper, we present a novel method to analyze the
similarity between the substructures of the imaged region and a hand
drawn template as a preprocessing step for computation of Pelvic
bone rotation on hip radiographs. This method consists of integrated
usage of Marker-controlled Watershed segmentation and Zernike
moment feature descriptor and it is used to detect Obturator Foramen
accurately. Marker-controlled Watershed segmentation is applied to
separate Obturator Foramen from the background effectively. Then,
Zernike moment feature descriptor is used to provide matching
between binary template image and the segmented binary image for
final extraction of Obturator Foramens. Finally, Pelvic bone rotation
rate calculation for each hip radiograph is performed automatically to
select and eliminate hip radiographs for further studies which depend
on Pelvic bone angle measurements. The proposed method is tested
on randomly selected 100 hip radiographs. The experimental results
demonstrated that the proposed method is able to segment Obturator
Foramen with 96% accuracy.
Abstract: An early diagnosis of bone metastasis is very
important for making a right decision on a subsequent therapy. One
of the most important steps to be taken initially, for developing a new
radiopharmaceutical is the measurement of organ radiation exposure
dose. In this study, the dosimetric studies of a novel agent for
SPECT-imaging of the bone metastasis, 111In-(4-
{[(bis(phosphonomethyl))carbamoyl]methyl}7,10bis(carboxymethyl)
-1,4,7,10-tetraazacyclododec-1-yl) acetic acid (111In-BPAMD)
complex, have been carried out to estimate the dose in human organs
based on the data derived from mice. The radiolabeled complex was
prepared with high radiochemical purity in the optimal conditions.
Biodistribution studies of the complex was investigated in the male
Syrian mice at the selected times after injection (2, 4, 24 and 48 h).
The human absorbed dose estimation of the complex was made based
on data derived from the mice by the radiation absorbed dose
assessment resource (RADAR) method. 111In-BPAMD complex was prepared with high radiochemical
purity >95% (ITLC) and specific activities of 2.85 TBq/mmol. Total
body effective absorbed dose for 111In-BPAMD was 0.205
mSv/MBq. This value is comparable to the other 111In clinically used
complexes. The results show that the dose with respect to the critical
organs is satisfactory within the acceptable range for diagnostic
nuclear medicine procedures. Generally, 111In-BPAMD has
interesting characteristics and it can be considered as a viable agent
for SPECT-imaging of the bone metastasis in the near future.
Abstract: Cesium molybdates with general formula
CsMIII(MoO4)2, where MIII = Bi, Dy, Pr, Er, exhibit rich
polymorphism, and crystallize in a layered structure. These properties
cause intensive studies on cesium molybdates. CsBi(MoO4)2 was synthesized by microwave method by using
cerium sulphate, bismuth oxide and molybdenum (VI) oxide in an
appropriate molar ratio. Characterizations were done by x-ray
diffraction (XRD), fourier transform infrared (FTIR) spectroscopy,
scanning electron microscopy/energy dispersive analyze (SEM/EDS),
thermo gravimetric/differantial thermal analysis (TG/DTA).
Abstract: Cost overruns are a persistent problem in oil and gas
megaprojects. Whilst the extant literature is filled with studies on
incidents and causes of cost overruns, underlying theories to explain
their emergence in oil and gas megaprojects are few. Yet, a way to
contain the syndrome of cost overruns is to understand the bases of
‘how and why’ they occur. Such knowledge will also help to develop
pragmatic techniques for better overall management of oil and gas
megaprojects. The aim of this paper is to explain the development of
cost overruns in hydrocarbon megaprojects through the perspective of
chaos theory. The underlying principles of chaos theory and its
implications for cost overruns are examined and practical
recommendations proposed. In addition, directions for future research
in this fertile area provided.
Abstract: Annihilations, phase shifts, scattering lengths and
elastic cross sections of low energy positrons scattering from
magnesium atoms were studied using the least-squares variational
method (LSVM). The possibility of positron binding to the
magnesium atoms is investigated. A trial wave function is suggested
to represent e+-Mg elastic scattering and scattering parameters were
derived to estimate the binding energy and annihilation rates. The
trial function is taken to depend on several adjustable parameters, and
is improved iteratively by increasing the number of terms. The
present results have the same behavior as reported semi-empirical,
theoretical and experimental results. Especially, the estimated
positive scattering length supports the possibility of positronmagnesium
bound state system that was confirmed in previous
experimental and theoretical work.
Abstract: Adoption of Information Systems (IS) is receiving
increasing attention such that its implications have been closely
monitored and studied by the IS management community, industry
and professional gatekeepers. Building on previous research
regarding the adoption of technology, this paper develops and
validates an integrated model of the adoption of mobile banking. The
model originates from the Technology Acceptance Model (TAM) and
the Theory of Planned Behaviour (TPB). This paper intends to offer a
preliminary scrutiny of the antecedents of the adoption of mobile
banking services in the context of a developing country. Data was
collected from Pakistan. The findings showed that an integrated TAM
and TPB model greatly explains the adoption intention of mobile
banking; and perceived behavioural control and its antecedents play a
significant role in predicting adoption Theoretical and managerial
implications of findings are presented and discussed.
Abstract: In this paper, we describe an application for face
recognition. Many studies have used local descriptors to characterize
a face, the performance of these local descriptors remain low by
global descriptors (working on the entire image). The application of
local descriptors (cutting image into blocks) must be able to store
both the advantages of global and local methods in the Discrete
Cosine Transform (DCT) domain. This system uses neural network
techniques. The letter method provides a good compromise between
the two approaches in terms of simplifying of calculation and
classifying performance. Finally, we compare our results with those
obtained from other local and global conventional approaches.
Abstract: The traditional rhythms of the West African country
of Guinea have played a centuries-long role in defining the different
people groups that make up the country. Throughout their history,
before and since colonization by the French, the different ethnicities
have used their traditional music as a distinct part of their historical
identities. That is starting to change. Guinea is an impoverished
nation created in the early twentieth-century with little regard for the
history and cultures of the people who were included. The traditional
rhythms of the different people groups and their heritages have
remained. Fifteen individual traditional Guinean rhythms were
chosen to represent popular rhythms from the four geographical
regions of Guinea. Each rhythm was traced back to its native village
and video recorded on-site by as many different local performing
groups as could be located. The cyclical patterns rhythms were
transcribed via a circular, spatial design and then copied into a box
notation system where sounds happening at the same time could be
studied. These rhythms were analyzed for their consistency-overperformance
in a Fundamental Rhythm Pattern analysis so rhythms
could be compared for how they are changing through different
performances. The analysis showed that the traditional rhythm
performances of the Middle and Forest Guinea regions were the most
cohesive and showed the least evidence of change between
performances. The role of music in each of these regions is both
limited and focused. The Coastal and High Guinea regions have
much in common historically through their ethnic history and
modern-day trade connections, but the rhythm performances seem to
be less consistent and demonstrate more changes in how they are
performed today. In each of these regions the role and usage of music
is much freer and wide-spread. In spite of advances being made as a
country, different ethnic groups still frequently only respond and
participate (dance and sing) to the music of their native ethnicity.
There is some evidence that this self-imposed musical barrier is
beginning to change and evolve, partially through the development of
better roads, more access to electricity and technology, the nationwide
Ebola health crisis, and a growing self-identification as a
unified nation.
Abstract: The article deals with the readiness of military
professionals for challenging situations. It discusses higher
requirements on the psychical endurance of military professionals
arising from the specific nature of the military occupation, which is
typical for being very difficult to maintain regularity, which is in
accordance with the hygiene of work alternated by relaxation. The
soldier must be able to serve in the long term and constantly intense
performance that goes beyond human tolerance to stress situations. A
challenging situation is always associated with overcoming
difficulties, obstacles and complicated circumstances or using
unusual methods, ways and means to achieve the desired (expected)
objectives, performing a given task or satisfying an important need.
This paper describes the categories of challenging situations, their
classification and characteristics. Attention is also paid to the
formation of personality in challenging situations, coping with stress
in challenging situations, Phases of solutions of stressful situations,
resistance to challenging life situations and its factors. Finally, the
article is focused on increasing the readiness of military professionals
for challenging situations.
Abstract: Exact solution of an unsteady MHD flow of elasticoviscous
fluid through a porous media in a tube of elliptic cross
section under the influence of magnetic field and 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 elliptical cross section by taking into
account of the porosity factor and magnetic parameter of the
bounding surface is investigated. The problem is solved in two-stages
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 non-dimensional
porosity parameter, magnetic parameter and elastico-viscosity
parameter, which depends on the Non-Newtonian coefficient. The
flow parameters are found to be identical with that of Newtonian case
as elastic-viscosity parameter, magnetic parameter tends to zero, and
porosity tends to infinity. The numerical results were simulated in
MATLAB software to analyze the effect of Elastico-viscous
parameter, porosity parameter, and magnetic parameter on velocity
profile. Boundary conditions were satisfied. It is seen that the effect
of elastico-viscosity parameter, porosity parameter and magnetic
parameter of the bounding surface has significant effect on the
velocity parameter.
Abstract: Abstract—[Tris (1,10-phenanthroline) lanthanum(III)]
trithiocyanate is a new compound that has shown high ability for
stopping the synthesis of DNA and also acting as a photosensitizer.
Nowadays, the radiation dose assessment resource (RADAR) method
is known as the most common method for absorbed dose calculation.
177Lu was produced by (n, gamma) reaction in a research reactor.
177Lu-PL3 was prepared in the optimized condition. The
radiochemical yield was checked by ITLC method. The
biodistribution of the complex was investigated by intravenously
injection to wild-type rats via their tail veins. In this study, the
absorbed dose of 177Lu-PL3 to human organs was estimated by
RADAR method. 177Lu was prepared with a specific activity of 2.6-3
GBq.mg-1 and radionuclide purity of 99.98 %. Final preparation of
the radiolabelled complex showed high radiochemical purity of >
99%. The results show that liver and spleen have received the highest
absorbed dose of 1.051 and 0.441 mSv/MBq, respectively. The
absorbed dose values for these two dose-limiting tissues suggest
more biological studies special in tumor-bearing animals.
Abstract: The measurement of organ radiation exposure dose is
one of the most important steps to be taken initially, for developing a
new radiopharmaceutical. In this study, the dosimetric studies of a
novel agent for SPECT-imaging of the bone metastasis, 111In-
1,4,7,10-tetraazacyclododecane-1,4,7,10 tetraethylene phosphonic
acid (111In-DOTMP) complex, have been carried out to estimate the
dose in human organs based on the data derived from rats. The
radiolabeled complex was prepared with high radiochemical purity in
the optimal conditions. Biodistribution studies of the complex was
investigated in the male Syrian rats at selected times after injection
(2, 4, 24 and 48 h). The human absorbed dose estimation of the
complex was made based on data derived from the rats by the
radiation absorbed dose assessment resource (RADAR) method.
111In-DOTMP complex was prepared with high radiochemical purity
of >99% (ITLC). Total body effective absorbed dose for 111In-
DOTMP was 0.061 mSv/MBq. This value is comparable to the other
111In clinically used complexes. The results show that the dose with
respect to the critical organs is satisfactory within the acceptable
range for diagnostic nuclear medicine procedures. Generally, 111In-
DOTMP has interesting characteristics and can be considered as a
viable agent for SPECT-imaging of the bone metastasis in the near
future.
Abstract: Here, we have shown the reaction of [Cr(ArN(CH2)3NAr)2Cl2] (1) where (Ar = 2,6-Pri
2C6H3) and in presence of NaCp (2) (Cp= C5H5 = cyclopentadien), with a center
coordination η5 interaction between Cp as co-ligand and chromium
metal center, for optimization we used density functional theory
(DFT), under methods, explicitly including electrons correlations, for
the final calculations as MB3LYP (Becke) (Lee–Yang–Parr) level of
theory we used to obtain more exact results. This complex was
calculated as electronic energy for molecular system, because the
calculation accounting all electrons correlations interactions. The
optimised of [Cr(ArN(CH2)3NAr)2(η5-Cp)] (Ar = 2,6-Pri2C6H3 and Cp = C5H5) was found to be thermally stable. By using Dewar-Chatt-Duncanson model, as a basis of the molecular orbital (MO) analysis
and showed the highest occupied molecular orbital (HOMO) and
lowest occupied molecular orbital LUMO.
Abstract: Evolutionary Algorithms (EAs) have been used
widely through evolution theory to discover acceptable solutions that
corresponds to challenges such as natural resources management.
EAs are also used to solve varied problems in the real world. EAs
have been rapidly identified for its ease in handling multiple
objective problems. Reservoir operations is a vital and researchable
area which has been studied in the last few decades due to the limited
nature of water resources that is found mostly in the semi-arid
regions of the world. The state of some developing economy that
depends on electricity for overall development through hydropower
production, a renewable form of energy, is appalling due to water
scarcity. This paper presents a review of the applications of
evolutionary algorithms to reservoir operation for hydropower
production. This review includes the discussion on areas such as
genetic algorithm, differential evolution, and reservoir operation. It
also identified the research gaps discovered in these areas. The results
of this study will be an eye opener for researchers and decision
makers to think deeply of the adverse effect of water scarcity and
drought towards economic development of a nation. Hence, it
becomes imperative to identify evolutionary algorithms that can
address this issue which can hamper effective hydropower
generation.