Abstract: We present a framework of researcher knowledge
development in conducting a study in mathematics education. The
key components of the framework are: knowledge germane to
conducting a particular study, processes of knowledge accumulation,
and catalyzing filters that influence a researcher decision making.
The components of the framework originated from a confluence
between constructs and theories in Mathematics Education, Higher
Education and Sociology. Drawing on a self-reflective interview with
a leading researcher in mathematics education, Professor Michèle
Artigue, we illustrate how the framework can be utilized in data
analysis. Criteria for framework evaluation are discussed.
Abstract: Feed oil samples which are used as mixed feed raw
material were taken from six different feed factories in March, May
and July. All factories make production in Konya, Turkey and all of
the samples were crude soybean oils. Physical and chemical analyses,
free radical scavenger effect, and total phenol content were
determined on these oil samples. Moisture (M) content was found
between 0.10-22.23%, saponification number (SF) was determined
143.13 to 167.93 KOH/kg, free fatty acidity (FFA) was varied 0.73 to
35.00%, peroxide value (PV) was found between 1.53 and 28.43
meq/kg, unsaponifiable matter (USM) was determined from 0.40 to
17.10%, viscosity (V) was found between 34.30 and 625.67 mPas,
sediment (S) amount was determined between 0.60-18.16%, free
radical scavenger effect (FRSE) was varied 20.7 to 43.04% inhibition
of the extract and total phenol (TPC) content was found between 1.20
and 2.69mg/L extract. Different results were found between months
and factories.
Abstract: Forward Osmosis (FO) polyamide thin-film composite
membranes have been prepared by interfacial polymerization using
commercial UF polyethersulfoneas membrane support. Different
interfacial polymerization times (10s, 30s and 60s) in the organic
solution containing trimesoyl chloride (TMC) at constant m-phenylenediamine
(MPD) concentration (2% w/v) were studied. The
synthesized polyamide membranes then tested for treatment of
natural organic matter (NOM) and compared to commercial Cellulose
TriAcetate (CTA) membrane. It was found that membrane prepared
with higher reaction time (30s and 60s) exhibited better membrane
performance (flux and humic acid removal) over commercial CTA
membrane.
Abstract: In this paper, the effects of fiber types and elevated
temperatures on compressive strength, modulus of rapture and the
bond characteristics of fiber reinforced concretes (FRC) are
presented. By using the three different types of fibers (steel fiber-SF,
polypropylene-PPF and polyvinyl alcohol-PVA), FRC specimens
were produced and exposed to elevated temperatures up to 800 ºC for
1.5 hours. In addition, a plain concrete (without fiber) was produced
and used as a control. Test results obtained showed that the steel fiber
reinforced concrete (SFRC) had the highest compressive strength,
modulus of rapture and bond stress values at room temperatures, the
residual bond, flexural and compressive strengths of both FRC and
plain concrete dropped sharply after exposure to high temperatures.
The results also indicated that the reduction of bond, flexural and
compressive strengths with increasing the exposed temperature was
relatively less for SFRC than for plain, and FRC with PPF and PVA.
Abstract: High gain broadband plasmonic slot nano-antenna has
been considered. The theory of plasmonic slot nano-antenna (PSNA)
has been developed. The analytical model takes into account also the
electrical field inside the metal due to imperfectness of metal in
optical range, as well as numerical investigation based on finite
element method (FEM) has been realized. It should be mentioned that
Yagi-Uda configuration improves directivity in the plane of structure.
In contrast, in this paper the possibility of directivity improvement of
proposed PSNA in perpendicular plane of structure by using
reflection metallic surface placed under the slot in fixed distance has
been demonstrated. It is well known that a directivity improvement
brings to the antenna gain increasing. This method of diagram
improving is also well known from RF antenna design theory.
Moreover the improvement of directivity in the perpendicular plane
gives more flexibility in such application as improving the light and
atom, ion, molecule interactions by using such type of plasmonic slot
antenna. By the analogy of dipole type optical antennas the widening
of working wavelengths has been realized by using bowtie geometry
of slots, which made the antenna broadband.
Abstract: The textile industry plays a major role in the economy
of India and on the other side of the coin it is the major source for
water pollution. As azo dyes is the largest dye class they are
extensively used in many fields such as textile industry, leather
tanning industry, paper production, food, color photography,
pharmaceuticals and medicine, cosmetic, hair colorings, wood
staining, agricultural, biological and chemical research etc. In
addition to these, they can have acute and/or chronic effects on
organisms depending on their concentration and length of exposure
when they discharged as effluent in the environment. The aim of this
study was to assess the genotoxic and histotoxic potentials of
environmentally relevant concentrations of C. I. Reactive Red 120
(RR 120) on Catla catla, important edible freshwater fingerlings. For
this, healthy Catla catla fingerlings were procured from the
Government Fish Farm and acclimatized in 100 L capacity and
continuously aerated glass aquarium in laboratory for 15 days.
According to APHA some physic-chemical parameters were
measured and maintained such as temperature, pH, dissolve oxygen,
alkalinity, total hardness. Water along with excreta had been changed
every 24 hrs. All fingerlings were fed artificial food palates once a
day @ body weight. After 15 days fingerlings were grouped in 5 (10
in each) and exposed to various concentrations of RR 120 (Control,
10, 20, 30 and 40 mg.l-1) and samples (peripheral blood and gills,
kidney) were collected and analyzed at 96 hrs. All results were
compared with the control. Micronuclei (MN), nuclear buds (NB),
fragmented-apoptotic (FA) and bi-nucleated (BN) cells in blood
smears and in tissues (gills and kidney cells) were observed.
Prominent histopathological alterations were noticed in gills such as
aneurism, hyperplasia, degenerated central axis, lifting of gill
epithelium, curved secondary gill lamellae etc. Similarly kidney
showed some detrimental changes like shrunken glomeruli with
increased periglomerular space, degenerated renal tubules etc. Both
haematological and histopathological changes clearly reveal the toxic
potential of RR 120. This work concludes that water pollution
assessment can be done by these two biomarkers which provide
baseline to the further chromosomal or molecular work.
Abstract: Dental porcelain composites reinforced and toughened
by 20 wt.% tetragonal zirconia (3Y-TZP) were processed by hot
pressing at 1000°C. Two types of particles were tested: yttriastabilized
zirconia (ZrO2–3%Y2O3) agglomerates and pre-sintered
yttria-stabilized zirconia (ZrO2–3%Y2O3) particles. The composites
as well as the reinforcing particles were analyzed by the means of
optical and Scanning Electron Microscopy (SEM), Energy Dispersion
Spectroscopy (EDS) and X-Ray Diffraction (XRD). The mechanical
properties were obtained by the transverse rupture strength test. Wear
tests were also performed on the composites and monolithic
porcelain. The best mechanical results were displayed by the
porcelain reinforced with the pre-sintered ZrO2–3%Y2O3
agglomerates.
Abstract: Flexible AC Transmission Systems (FACTS) is
granting a new group of advanced power electronic devices emerging
for enhancement of the power system performance. Unified Power
Flow Controller (UPFC) is a recent version of FACTS devices for
power system applications. The back-up energy supply system
incorporated with UPFC is providing a complete control of real and
reactive power at the same time and hence is competent to improve
the performance of an electrical power system. In this article, backup
energy supply unit such as superconducting magnetic energy storage
(SMES) is integrated with UPFC. In addition, comparative
exploration of UPFC–battery, UPFC–UC and UPFC–SMES
performance is evaluated through the vibrant simulation by using
MATLAB/Simulink software.
Abstract: Taking into account the significance of measuring the
daily use of the study space in the libraries in order to develop and
reorganize the space for enhancing the efficiency of the study space,
the current study aimed to apply GIS in analyzing the study halls of
the Central Library and Document Center of Tehran University in
order to determine how study desks and chairs were used by the
students. The study used a combination of survey-descriptive and
system design method. In order to gather the required data, surveydescriptive
method was used. For implementing and entering data
into ArcGIS and analyzing the data and displaying the results on the
maps of the study halls of the library, system design method was
utilized. The design of the spatial database of the use of the study
halls was measured through the extent of occupancy of the space by
the library users and the maps of the study halls of the central library
of Tehran University as the case study. The results showed that
Abooreyhan hall had the highest rate of occupancy of the desks and
chairs compared to the other halls. The Hall of Science and
Technology, with an average occupancy rate of 0.39 for the tables
represented the lowest number of users and Rashid al-Dins hall, and
Science and Technology hall with an average occupancy rate (0.40)
had the lowest number of users for seats. In this study, the
comparison of the space occupied at different periods in the morning,
evenings, afternoons, and several months was performed through
GIS. This system analyzed the space relationships effectively and
efficiently. The output of this study would be used by administrators
and librarians to determine the exact extent of use of the equipment
of the study halls and librarians can use the output map to design the
space more efficiently at the library.
Abstract: Nanofibers of PVA /nickel nitrate/silica/alumina
izopropoxide/boric acid composite were prepared by using sol-gel
processing and electrospinning technique. By high temperature
calcinations of the above precursor fibers, nanofibers of
NiO/Al2O3/B2O3/SiO2 composite with diameters about 500 nm
could be successfully obtained. The fibers were characterized by
XRD and SEM analyses.
Abstract: There are several possibilities of reducing the required
amount of cement in concrete production. Natural zeolite is one of
the raw materials which can partly substitute Portland cement. The
effort to reduce the amount of Portland cement used in concrete
production is brings both economical as well as ecological benefits.
The paper presents the properties of concrete containing natural
zeolite as an active admixture in the concrete which partly substitutes
Portland cement. The properties discussed here bring information
about the basic mechanical properties and frost resistance of concrete
containing zeolite. The properties of concretes with the admixture of
zeolite are compared with a reference concrete with no content of
zeolite. The properties of the individual concretes are observed for
360 days.
Abstract: Many organizations are investing in web applications
and technologies in order to be competitive, some of them could not
achieve its goals. The quality of web-based applications could play
an important role for organizations to be competitive. So the aim of
this study is to investigate the impact of quality of web-based
applications to achieve a competitive advantage. A new model has
been developed. An empirical investigation was performed on a
banking sector in Jordan to test the new model. The results show that
impact of web-based applications on competitive advantage is
significant. Finally, further work is planned to validate and evaluate
the proposed model using several domains.
Abstract: In order to protect data privacy, image with sensitive or
private information needs to be encrypted before being outsourced to
the cloud. However, this causes difficulties in image retrieval and data
management. A secure image retrieval method based on orthogonal
decomposition is proposed in the paper. The image is divided into two
different components, for which encryption and feature extraction are
executed separately. As a result, cloud server can extract features from
an encrypted image directly and compare them with the features of the
queried images, so that the user can thus obtain the image. Different
from other methods, the proposed method has no special requirements
to encryption algorithms. Experimental results prove that the proposed
method can achieve better security and better retrieval precision.
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: Non-water based fixed abrasive polishing was adopted
to manufacture LBO crystal for nano precision surface quality because
of its deliquescent. Ethyl alcohol was selected as the non-water based
slurry solvent and ethanediamine, lactic acid, hydrogen peroxide was
added in the slurry as a chemical additive, respectively. Effect of
different additives with non-water based slurry on material removal
rate, surface topography, microscopic appearances, and surface
roughness were investigated in fixed abrasive polishing of LBO
crystal. The results show the best surface quality of LBO crystal with
surface roughness Sa 8.2 nm and small damages was obtained by
non-water based slurry with lactic acid. Non-water based fixed
abrasive polishing can achieve nano precision surface quality of LBO
crystal with high material removal.
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: The design philosophy of building structure has been
changing time to time. The reason for this is because of an increase of
human inertest, an improved building materials and technology that
will impact how we live, to speed up construction period and natural
effect which includes earthquake disasters and environmental effect.
One technique which takes in to account the above case is using a
prefabricable structural system. In which each and every structural
element is designed and prefabricated and assembled on a site so that
the construction speed is increased and the environmental impact is
also enhanced. This system has an immense advantage such as: reduce
construction cost, reusable, recyclable, speed up construction period
and less environmental effect. In this study, it is tried to present some
of the developed and evaluated structural elements of building
structures.