Abstract: Low density polyethylene (LDPE) nanocomposites
with 3, 5 and 7 wt. % cobalt ferrite (CoFe2O4) nanopowder fabricated
with extrusion mixing and followed up by hot press to reach compact
samples. The transmission/reflection measurements were carried out
with a network analyzer in the frequency range of 8-12 GHz. By
increasing the percent of CoFe2O4 nanopowder, reflection loss (S11)
increases, while transferring loss (S21) decreases. Reflectivity (R)
calculations made using S11 and S21. Increase in percent of CoFe2O4
nanopowder up to 7 wt. % in composite leaded to higher reflectivity
amount, and revealed that increasing the percent of CoFe2O4
nanopowder up to 7 wt. % leads to further microwave absorption in
8-12 GHz range.
Abstract: Success means different things for different people.
For us, project managers, it becomes even harder to actually find a
definition. Many factors have to be included in the evaluation.
Moreover, literature is not very helpful, lacking consensus and
neutrality. Post-implementation reviews (PIR) can be an efficient tool
in evaluating how things worked on a certain project. Despite the
visible progress, PIR is not a very detailed subject yet and there is not
common understanding in this matter. This may be the reason that
some organizations include it in the projects’ lifecycle and some do
not. Through this paper, we point out the reasons why all project
managers should pay proper attention to this important step and to the
elements which can be assessed, beside the already famous triple
constraints: cost, budget and time. It is essential to take notice that PIR is not a checklist. It brings the
edge in eliminating subjectivity and judging projects based on actual
proof. Based on our experience, our success indicator model,
presented in this paper, contributes to the success of the project! In
the same time, it increases trust among customers who will perceive
success more objectively.
Abstract: This paper investigates the characteristics of wall
pressure fluctuations in naturally developing boundary layer flows
on axisymmetric bodies experimentally. The axisymmetric body has
a modified ellipsoidal blunt nose. Flush-mounted microphones are
used to measure the wall pressure fluctuations in the boundary layer
flow over the body. The measurements are performed in a low noise
wind tunnel. It is found that the correlation between the flow regime
and the characteristics of the pressure fluctuations is distinct. The
process from small fluctuation in laminar flow to large fluctuation in
turbulent flow is investigated. Tollmien-Schlichting wave (T-S wave)
is found to generate and develop in transition. Because of the T-S
wave, the wall pressure fluctuations in the transition region are higher
than those in the turbulent boundary layer.
Abstract: Game-based learning can enhance the learning
motivation of students and provide a means for them to learn through
playing games. This study used augmented reality technology to
develop an interactive card game as a game-based teaching aid for
delivering elementary school science course content with the aim of
enhancing student learning processes and outcomes. Through playing
the proposed card game, students can familiarize themselves with
appearance, features, and foraging behaviors of insects. The system
records the actions of students, enabling teachers to determine their
students’ learning progress. In this study, 37 students participated in an
assessment experiment and provided feedback through questionnaires.
Their responses indicated that they were significantly more motivated
to learn after playing the game, and their feedback was mostly
positive.
Abstract: Digital images are widely used in computer
applications. To store or transmit the uncompressed images
requires considerable storage capacity and transmission bandwidth.
Image compression is a means to perform transmission or storage of
visual data in the most economical way. This paper explains about
how images can be encoded to be transmitted in a multiplexing
time-frequency domain channel. Multiplexing involves packing
signals together whose representations are compact in the working
domain. In order to optimize transmission resources each 4 × 4
pixel block of the image is transformed by a suitable polynomial
approximation, into a minimal number of coefficients. Less than
4 × 4 coefficients in one block spares a significant amount of
transmitted information, but some information is lost. Different
approximations for image transformation have been evaluated as
polynomial representation (Vandermonde matrix), least squares +
gradient descent, 1-D Chebyshev polynomials, 2-D Chebyshev
polynomials or singular value decomposition (SVD). Results have
been compared in terms of nominal compression rate (NCR),
compression ratio (CR) and peak signal-to-noise ratio (PSNR)
in order to minimize the error function defined as the difference
between the original pixel gray levels and the approximated
polynomial output. Polynomial coefficients have been later encoded
and handled for generating chirps in a target rate of about two
chirps per 4 × 4 pixel block and then submitted to a transmission
multiplexing operation in the time-frequency domain.
Abstract: The objective of this study was to examine the
relationship between transformational leadership and innovative work
behavior and to evaluate the mediating role of leader-member
exchange relationships (LMX) on the assumed relationship. This
study has focused on the suggestion that LMX might emerge through
transformational leadership behaviors and thus could mediate the
relationship between transformational leadership and innovative
behavior. A cross-sectional survey research has been conducted on
the relationship these leadership approaches and their impact on
organizational HRM-outcomes have been conducted on two
organizations operating in the technical sector in Istanbul-Turkey.
The results of the research have supported the hypotheses.
Transformational leadership was positively related to the innovative
behaviors and LMX emerged to mediate that relationship.
Abstract: In wireless sensor network, sensor node transmits the
sensed data to the sink node in multi-hop communication
periodically. This high traffic induces congestion at the node which is
present one-hop distance to the sink node. The packet transmission
and reception rate of these nodes should be very high, when
compared to other sensor nodes in the network. Therefore, the energy
consumption of that node is very high and this effect is known as the
“funneling effect”. The tree based-data aggregation technique
(TBDA) is used to reduce the energy consumption of the node. The
throughput of the overall performance shows a considerable decrease
in the number of packet transmissions to the sink node. The proposed
scheme, TBDA, avoids the funneling effect and extends the lifetime
of the wireless sensor network. The average case time complexity for
inserting the node in the tree is O(n log n) and for the worst case time
complexity is O(n2).
Abstract: In this paper, an attempt has been made for the design
of a robotic library using an intelligent system. The robot works on
the ARM microprocessor, motor driver circuit with 5 degrees of
freedom with Wi-Fi and GPS based communication protocol. The
authenticity of the library books is controlled by RFID. The proposed
robotic library system is facilitated with embedded system and ARM.
In this library issuance system, the previous potential readers’
authentic review reports have been taken into consideration for
recommending suitable books to the deserving new users and the
issuance of books or periodicals is based on the users’ decision. We
have conjectured that the Wi-Fi based robotic library management
system would allow fast transaction of books issuance and it also
produces quality readers.
Abstract: Maintenance and design engineers have great concern
for the functioning of rotating machineries due to the vibration
phenomenon. Improper functioning in rotating machinery originates
from the damage to rolling element bearings. The status of rolling
element bearings require advanced technologies to monitor their
health status efficiently and effectively. Avoiding vibration during
machine running conditions is a complicated process. Vibration
simulation should be carried out using suitable sensors/ transducers to
recognize the level of damage on bearing during machine operating
conditions. Various issues arising in rotating systems are interlinked
with bearing faults. This paper presents an approach for fault
diagnosis of bearings using neural networks and time/frequencydomain
vibration analysis.
Abstract: In India, most of the pavement is laid by bituminous
road and the consumption of binder is high for pavement construction
and also modified binders are used to satisfy any specific pavement
requirement. Since the binders are visco-elastic material which is
having the mechanical properties of binder transition from viscoelastic
solid to visco-elastic fluid. In this paper, two different
protocols were used to measure the viscosity property of binder using
a Brookfield Viscometer and there is a need to find the appropriate
mixing and compaction temperatures of various types of binders
which can result in complete aggregate coating and adequate field
density of HMA mixtures. The aim of this work is to find the
transition temperature from Non-Newtonian behavior to Newtonian
behavior of the binder by adopting a steady shear protocol and the
shear rate ramp protocol. The transition from non-Newtonian to
Newtonian can occur through an increase of temperature and shear of
the material. The test has been conducted for unmodified binder VG
30. The transition temperature was found in the unmodified binder
VG is 120oC. Therefore, the application of both modified binder and
unmodified binder in the pavement construction needs to be studied
properly by considering temperature and traffic loading factors of the
respective project site.
Abstract: Cochlear Implantation (CI) which became a routine
procedure for the last decades is an electronic device that provides a
sense of sound for patients who are severely and profoundly deaf.
The optimal success of this implantation depends on the electrode
technology and deep insertion techniques. However, this manual
insertion procedure may cause mechanical trauma which can lead to
severe destruction of the delicate intracochlear structure.
Accordingly, future improvement of the cochlear electrode implant
insertion needs reduction of the excessive force application during
the cochlear implantation which causes tissue damage and trauma.
This study is examined tool-tissue interaction of large prototype scale
digit embedded with distributive tactile sensor based upon cochlear
electrode and large prototype scale cochlea phantom for simulating
the human cochlear which could lead to small scale digit
requirements. The digit, distributive tactile sensors embedded with
silicon-substrate was inserted into the cochlea phantom to measure
any digit/phantom interaction and position of the digit in order to
minimize tissue and trauma damage during the electrode cochlear
insertion. The digit have provided tactile information from the digitphantom
insertion interaction such as contact status, tip penetration,
obstacles, relative shape and location, contact orientation and
multiple contacts. The tests demonstrated that even devices of such a
relative simple design with low cost have potential to improve
cochlear implant surgery and other lumen mapping applications by
providing tactile sensory feedback information and thus controlling
the insertion through sensing and control of the tip of the implant
during the insertion. In that approach, the surgeon could minimize the
tissue damage and potential damage to the delicate structures within
the cochlear caused by current manual electrode insertion of the
cochlear implantation. This approach also can be applied to other
minimally invasive surgery applications as well as diagnosis and path
navigation procedures.
Abstract: The occurrences of precipitation, also commonly
referred as rain, in the form of "convective" and "stratiform" have
been identified to exist worldwide. In this study, the radar return
echoes or known as reflectivity values acquired from radar scans
have been exploited in the process of classifying the type of rain
endured. The investigation use radar data from Malaysian
Meteorology Department (MMD). It is possible to discriminate the
types of rain experienced in tropical region by observing the vertical
characteristics of the rain structure. .Heavy rain in tropical region
profoundly affects radiowave signals, causing transmission
interference and signal fading. Required wireless system fade margin
depends on the type of rain. Information relating to the two
mentioned types of rain is critical for the system engineers and
researchers in their endeavour to improve the reliability of
communication links. This paper highlights the quantification of
percentage occurrences over one year period in 2009.
Abstract: Lightweight and efficient structures have the aim to
enhance the efficiency of the components in various industries.
Toward this end, composites are one of the most widely used
materials because of durability, high strength and modulus, and low
weight. One type of the advanced composites is grid-stiffened
composite (GSC) structures, which have been extensively considered
in aerospace, automotive, and aircraft industries. They are one of the
top candidates for replacing some of the traditional components,
which are used here. Although there are a good number of published
surveys on the design aspects and fabrication of GSC structures, little
systematic work has been reported on their material modification to
improve their properties, to our knowledge. Matrix modification
using nanoparticles is an effective method to enhance the flexural
properties of the fibrous composites. In the present study, a silanecoupling
agent (3-glycidoxypropyltrimethoxysilane/3-GPTS) was
introduced onto the silica (SiO2) nanoparticle surface and its effects
on the three-point flexural response of isogrid E-glass/epoxy
composites were assessed. Based on the Fourier Transform Infrared
Spectrometer (FTIR) spectra, it was inferred that the 3-GPTS
coupling agent was successfully grafted onto the surface of SiO2
nanoparticles after modification. Flexural test revealed an
improvement of 16%, 14%, and 36% in stiffness, maximum load and
energy absorption of the isogrid specimen filled with 3 wt.% 3-
GPTS/SiO2 compared to the neat one. It would be worth mentioning
that in these structures, considerable energy absorption was observed
after the primary failure related to the load peak. In addition, 3-
GPTMS functionalization had a positive effect on the flexural
behavior of the multiscale isogrid composites. In conclusion, this
study suggests that the addition of modified silica nanoparticles is a
promising method to improve the flexural properties of the gridstiffened
fibrous composite structures.
Abstract: Mineral product, waste concrete (fine aggregates),
waste in the optical field, industry, and construction employ separators
to separate solids and classify them according to their size. Various
sorting machines are used in the industrial field such as those operating
under electrical properties, centrifugal force, wind power, vibration,
and magnetic force. Study on separators has been carried out to
contribute to the environmental industry. In this study, we perform
CFD analysis for understanding the basic mechanism of the separation
of waste concrete (fine aggregate) particles from air with a machine
built with a rotor with blades. In CFD, we first performed
two-dimensional particle tracking for various particle sizes for the
model with 1 degree, 1.5 degree, and 2 degree angle between each
blade to verify the boundary conditions and the method of rotating
domain method to be used in 3D. Then we developed 3D numerical
model with ANSYS CFX to calculate the air flow and track the
particles. We judged the capability of particle separation for given size
by counting the number of particles escaping from the domain toward
the exit among 10 particles issued at the inlet. We confirm that
particles experience stagnant behavior near the exit of the rotating
blades where the centrifugal force acting on the particles is in balance
with the air drag force. It was also found that the minimum particle
size that can be separated by the machine with the rotor is determined
by its capability to stay at the outlet of the rotor channels.
Abstract: Issues relating to the destructive phenomena that can
damage people and goods have returned to the centre of debate in
Italy with the increase in catastrophic episodes in recent years in a
country which is highly vulnerable to hydrological risk.
Environmental factors and geological and geomorphological
territorial characteristics play an important role in determining the
level of vulnerability and the natural tendency to risk. However, a
territory has also been subjected to the requirements of and
transformations of society and this brings other relevant factors. The
reasons for the increase in destructive phenomena are often to be
found in the territorial development models adopted. Stewardship of
the landscape and management of risk are related issues. This study aims to summarize the most relevant elements about
this connection and at the same time to clarify the role of
environmental risk assessment as a tool to aid in the sustainable
management of landscape. Finally, the study reflects on how regional
and urban planners deal with environmental risk and which aspects
should be monitored in order to adopt responsible and useful
interventions.
Abstract: Hard coatings are widely used in cutting and forming
tool industries. Titanium Nitride (TiN) possesses good hardness,
strength, and corrosion resistance. The coating properties are
influenced by many process parameters. The coatings were deposited
on steel substrate by changing the process parameters such as
substrate temperature, nitrogen flow rate and target power in a D.C
planer magnetron sputtering. The structure of coatings were analysed
using XRD. The hardness of coatings was found using Micro
hardness tester. From the experimental data, a regression model was
developed and the optimum response was determined using Response
Surface Methodology (RSM).
Abstract: Contemporary metropolitan areas and large cities are
dynamic, rapidly growing and continuously changing. Thus, urban
transformations and mutations are not a new phenomenon, but rather
a continuous process. Basic factors of urban transformation are
related to development of technologies, globalisation, lifestyle, etc.,
which in combination with local factors have generated an extremely
great variety of urban development conditions. This article discusses
the main urbanisation processes in Lithuania during last 50-year
period and social factors affecting urban functional mutations.
Abstract: Zinc borates are used as a multi-functional flame
retardant additive for its high dehydration temperature. In this study,
the method of ultrasonic mixing was used in the synthesis of zinc
borates. The reactants of zinc oxide (ZnO) and boric acid (H3BO3)
were used at the constant reaction parameters of 90°C reaction
temperature and 55 min of reaction time. Several molar ratios of
ZnO:H3BO3 (1:1, 1:2, 1:3, 1:4 and 1:5) were conducted for the
determination of the optimum reaction ratio. Prior to synthesis the
characterization of the synthesized zinc borates were made by X-Ray
Diffraction (XRD) and Fourier Transform Infrared Spectroscopy
(FT-IR). From the results Zinc Oxide Borate Hydrate
[Zn3B6O12.3.5H2O], were synthesized optimum at the molar ratio of
1:3, with a reaction efficiency of 95.2%.
Abstract: This first-attempt study revealed that decolorized
intermediates of azo dyes could act as redox mediators to assist
wastewater (WW) decolorization due to enhancement of
electron-transport phenomena. Electrochemical impedance spectra
indicated that hydroxyl and amino-substituent(s) were functional
group(s) as redox-mediator(s). As azo dyes are usually multiple
benzene-rings structured, their derived decolorized intermediates are
likely to play roles of electron shuttles due to lower barrier of energy
gap for electron shuttling. According to cyclic voltammetric profiles,
redox mediating characteristics of decolorized intermediates of azo
dyes (e.g., RBu171, RR198, RR141, RBk5) were clearly disclosed.
With supplementation of biodecolorized metabolites of RR141 and
198, decolorization performance of could be evidently augmented.
This study also suggested the optimal modes of microbial fuel cell
(MFC)-assisted WW decolorization would be plug-flow or batch
mode of operation with no mix. Single chamber-MFCs would be more
favourable than double chamber MFCs due to non-mixing contacting
reactor scheme for operation.
Abstract: Fluctuations of Schottky diode parameters in a
structure of the mixer are investigated. These fluctuations are
manifested in two ways. At the first, they lead to fluctuations in the
transfer factor that is lead to the amplitude fluctuations in the signal
of intermediate frequency. On the basis of the measurement data of
1/f noise of the diode at forward current, the estimation of a spectrum
of relative fluctuations in transfer factor of the mixer is executed.
Current dependence of the spectrum of relative fluctuations in
transfer factor of the mixer and dependence of the spectrum of
relative fluctuations in transfer factor of the mixer on the amplitude
of the heterodyne signal are investigated. At the second, fluctuations
in parameters of the diode lead to occurrence of 1/f noise in the
output signal of the mixer. This noise limits the sensitivity of the
mixer to the value of received signal.