Abstract: For several hundred years, the design of railway tracks
has practically remained unchanged. Traditionally, rail tracks are
placed on a ballast layer due to several reasons, including economy,
rapid drainage, and high load bearing capacity. The primary function
of ballast is to distributing dynamic track loads to sub-ballast and
subgrade layers, while also providing lateral resistance and allowing
for rapid drainage. Upon repeated trainloads, the ballast becomes
fouled due to ballast degradation and the intrusion of fines which
adversely affects the strength and deformation behaviour of ballast.
This paper presents the use of three-dimensional discrete element
method (DEM) in studying the shear behaviour of the fouled ballast
subjected to direct shear loading. Irregularly shaped particles of
ballast were modelled by grouping many spherical balls together in
appropriate sizes to simulate representative ballast aggregates. Fouled
ballast was modelled by injecting a specified number of miniature
spherical particles into the void spaces. The DEM simulation
highlights that the peak shear stress of the ballast assembly decreases
and the dilation of fouled ballast increases with an increase level of
fouling. Additionally, the distributions of contact force chain and
particle displacement vectors were captured during shearing progress,
explaining the formation of shear band and the evolutions of
volumetric change of fouled ballast.
Abstract: Parental expectations often differ to that of their children and the influence and involvement of parents, at home, may affect the student performance in the classroom. This paper presents results from a survey of Asian and European background secondary school mathematics students (N=128) in Melbourne, Australia. Student responses to survey questions were analysed using confirmatory factor analysis, followed by t-tests and ANOVA. The aim of the analysis was to identify similarities and differences in parental expectations in relation to ethnicity, gender, and the year level of the students. The notable findings from the analysis showed no significant difference (at 0.05 level) in parental expectations and student performance, in relation to ethnicity or gender. Conversely, there was a significant difference in both parental expectations and student performance between year 7 and year 12 students. Further, whilst there was a significant difference in parental expectations between year 7 and year 11 students, the students’ performances were not significantly different. The results suggest further research may be needed to understand the parental expectations and student performance between the lower and upper secondary school mathematics students.
Abstract: We have aimed to produce a self-cleaning transparent
polymer coating with polyurethane (PU) matrix as the latter is highly
solvent, chemical and weather resistant having good mechanical
properties. Nano-silica modified by 1H, 1H, 2H, 2Hperflurooctyltriethoxysilane
was incorporated into the PU matrix for
attaining self-cleaning ability through hydrophobicity. The
modification was confirmed by particle size analysis and scanning
electron microscopy (SEM). Thermo-gravimetric (TGA) studies were
carried to ascertain the grafting of silane onto the silica. Several
coating formulations were prepared by varying the silica loading
content and compared to a commercial equivalent. The effect of
dispersion and the morphology of the coated films were assessed by
SEM analysis. All coating standardized tests like solvent resistance,
adhesion, flexibility, acid, alkali, gloss etc. have been performed as
per ASTM standards. Water contact angle studies were conducted to
analyze the hydrophobic character of the coating. In addition, the
coatings were also subjected to salt spray and accelerated weather
testing to analyze the durability of the coating.
Abstract: The purpose of the research described in this work is
to answer how to measure the rheologic (viscoelastic) properties
tendo–deformational characteristics of soft tissue. The method would
also resemble muscle palpation examination as it is known in clinical
practice. For this purpose, an instrument with the working name
“myotonometer” has been used. At present, there is lack of objective methods for assessing the
muscle tone by viscous and elastic properties of soft tissue. That is
why we decided to focus on creating or finding quantitative and
qualitative methodology capable to specify muscle tone.
Abstract: A 15-storey RC building, studied in this paper, is
representative of modern building type constructed in Madina City in
Saudi Arabia before 10 years ago. These buildings are almost
consisting of reinforced concrete skeleton i.e. columns, beams and
flat slab as well as shear walls in the stairs and elevator areas
arranged in the way to have a resistance system for lateral loads
(wind – earthquake loads). In this study, the dynamic properties of
the 15-storey RC building were identified using ambient motions
recorded at several, spatially-distributed locations within each
building. Three dimensional pushover analysis (Nonlinear static
analysis) was carried out using SAP2000 software incorporating
inelastic material properties for concrete, infill and steel. The effect
of modeling the building with and without infill walls, on the
performance point as well as capacity and demand spectra due to EQ
design spectrum function in Madina area has been investigated. ATC-
40 capacity and demand spectra are utilized to get the modification
factor (R) for the studied building. The purpose of this analysis is to
evaluate the expected performance of structural systems by
estimating, strength and deformation demands in design, and
comparing these demands to available capacities at the performance
levels of interest. The results are summarized and discussed.
Abstract: Concrete is an essential building material which is
widely used in construction industry all over the world due to its
compressible strength. Curing of concrete plays a vital role in
durability and other performance necessities. Improper curing can
affect the concrete performance and durability easily. When areas
like scarcity of water, structures is not accessible by humans external
curing cannot be performed, so we opt for internal curing. Internal
curing (or) self curing plays a major role in developing the concrete
pore structure and microstructure. The concept of internal curing is to
enhance the hydration process to maintain the temperature uniformly.
The evaporation of water in the concrete is reduced by self curing
agent (Super Absorbing Polymer – SAP) there by increasing the
water retention capacity of the concrete. The research work was
carried out to reduce water, which is prime material used for concrete
in the construction industry. Concrete curing plays a major role in
developing hydration process. Concept of self curing will reduce the
evaporation of water from concrete. Self curing will increase water
retention capacity as compared to the conventional concrete. Proper
self curing (or) internal curing increases the strength, durability and
performance of concrete. Super absorbing Polymer (SAP) used as
internal curing agent. In this study 0.2% to 0.4% of SAP was varied
in different grade of high strength concrete. In the experiment
replacement of cement by silica fumes with 5%, 10% and 15% are
studied. It is found that replacement of silica fumes by 10 % gives
more strength and durability when compared to others.
Abstract: The construction of most coastal infrastructure developments around the world are usually made considering wave height, current velocities and river discharges; however, little effort has been paid to surveying sediment transport during dredging or the modification to currents outside the ports or marinas during and after the construction. This study shows a complete survey during the construction of one of the largest ports of the Gulf of Mexico. An anchored Acoustic Doppler Current Velocity profiler (ADCP), a towed ADCP and a combination of model outputs were used at the Veracruz port construction in order to describe the hourly sediment transport and current modifications in and out of the new port. Owing to the stability of the system the new port was construction inside Vergara Bay, a low wave energy system with a tidal range of up to 0.40 m. The results show a two-current system pattern within the bay. The north side of the bay has an anticyclonic gyre, while the southern part of the bay shows a cyclonic gyre. Sediment transport trajectories were made every hour using the anchored ADCP, a numerical model and the weekly data obtained from the towed ADCP within the entire bay. The sediment transport trajectories were carefully tracked since the bay is surrounded by coral reef structures which are sensitive to sedimentation rate and water turbidity. The survey shows that during dredging and rock input used to build the wave breaker sediments were locally added (< 2500 m2) and local currents disperse it in less than 4 h. While the river input located in the middle of the bay and the sewer system plant may add more than 10 times this amount during a rainy day or during the tourist season. Finally, the coastal line obtained seasonally with a drone suggests that the southern part of the bay has not been modified by the construction of the new port located in the northern part of the bay, owing to the two subsystem division of the bay.
Abstract: Excessive vibration means increased wear, increased
repair efforts, bad product selection & quality and high energy
consumption. This may be sometimes experienced by cavitation or
suction/discharge recirculation which could occur only when net
positive suction head available NPSHA drops below the net positive
suction head required NPSHR. Cavitation can cause axial surging, if it
is excessive, will damage mechanical seals, bearings, possibly other
pump components frequently, and shorten the life of the impeller.
Efforts have been made to explain Suction Energy (SE), Specific
Speed (Ns), Suction Specific Speed (Nss), NPSHA, NPSHR & their
significance, possible reasons of cavitation /internal recirculation, its
diagnostics and remedial measures to arrest and prevent cavitation in
this paper. A case study is presented by the author highlighting that
the root cause of unwanted noise and vibration is due to cavitation,
caused by high specific speeds or inadequate net- positive suction
head available which results in damages to material surfaces of
impeller & suction bells and degradation of machine performance, its
capacity and efficiency too. Author strongly recommends revisiting
the technical specifications of CW pumps to provide sufficient NPSH
margin ratios >1.5, for future projects and Nss be limited to 8500 -
9000 for cavitation free operation.
Abstract: A combined heat and power (CHP) system is an efficient and clean way to generate power (electricity). Heat produced by the CHP system can be used for water and space heating. The CHP system which uses hydrogen as fuel produces zero carbon emission. Its’ efficiency can reach more than 80% whereas that of a traditional power station can only reach up to 50% because much of the thermal energy is wasted. The other advantages of CHP systems include that they can decentralize energy generation, improve energy security and sustainability, and significantly reduce the energy cost to the users. This paper presents the economic benefits of using a CHP system in the domestic environment. For this analysis, natural gas is considered as potential fuel as the hydrogen fuel cell based CHP systems are rarely used. UK government incentives for CHP systems are also considered as the added benefit. Results show that CHP requires a significant initial investment in returns it can reduce the annual energy bill significantly. Results show that an investment may be paid back in 7 years. After the back period, CHP can run for about 3 years as most of the CHP manufacturers provide 10 year warranty.
Abstract: The study of the aerodynamics related to the
improvement in the acting of airplanes and automobiles with the
objective of being reduced the effect of the attrition of the air on
structures, providing larger speeds and smaller consumption of fuel.
The application of the knowledge of the aerodynamics not more
limits to the aeronautical and automobile industries. Therefore, this
research aims to design and construction of a wind tunnel to perform
aerodynamic analysis in bodies of cars, seeking greater efficiency.
Therefore, this research aims to design and construction of a wind
tunnel to perform aerodynamic analysis in bodies of cars, seeking
greater efficiency. For this, a methodology for wind tunnel type
selection is designed to be built, taking into account the various
existing configurations in which chose to build an open circuit tunnel,
due to the lower complexity of construction and installation;
operational simplicity and low cost. The guidelines for the project
were teaching: the layer that limits study and analyze specimens with
different geometries. For the variation of pressure in the test, section
of a switched gauge used a pitot tube. Thus, it was possible to obtain
quantitative and qualitative results, which proved to be satisfactory.
Abstract: Biodiesel is widely investigated to solve the twin
problem of depletion of fossil fuel and environmental degradation.
The main objective of the present work is to compare performance,
emissions, and combustion characteristics of biodiesel derived from
cotton seed oil in a diesel engine with the baseline results of
petrodiesel fuel. Tests have been conducted on a single cylinder, four
stroke CIDI diesel engine with a speed of 1500 rpm and a fixed
compression ratio of 17.5 at different load conditions. The
performance parameters evaluated include brake thermal efficiency,
brake specific fuel consumption, brake power, indicated mean
effective pressure, mechanical efficiency, and exhaust gas
temperature. Regarding combustion study, cylinder pressure, rate of
pressure rise, net heat release rate, cumulative heat release, mean gas
temperature, mass fraction burned, and fuel line pressure were
evaluated. The emission parameters such as carbon monoxide, carbon
dioxide, un-burnt hydrocarbon, oxides of nitrogen, and smoke
opacity were also measured by a smoke meter and an exhaust gas
analyzer and compared with baseline results. The brake thermal
efficiency of cotton seed oil methyl ester (CSOME) was lower than
that of petrodiesel and brake specific fuel consumption was found to
be higher. However, biodiesel resulted in the reduction of carbon
dioxide, un-burnt hydrocarbon, and smoke opacity at the expense of
nitrogen oxides. Carbon monoxide emissions for biodiesel was higher
at maximum output power. It has been found that the combustion
characteristics of cotton seed oil methyl ester closely followed those
of standard petrodiesel. The experimental results suggested that
biodiesel derived from cotton seed oil could be used as a good
substitute to petrodiesel fuel in a conventional diesel without any
modification.
Abstract: Energy consumption of a hotel can be a hot topic in
smart city; it is difficult to evaluate the contribution of impact factors
to energy consumption of a hotel. Therefore, grasping the key impact
factors has great effect on the energy saving management of a hotel.
Based on the SPIRTPAT model, we establish the identity with the
impact factors of occupancy rate, unit area of revenue, temperature
factor, unit revenue of energy consumption. In this paper, we use the
LMDI (Logarithmic Mean Divisia Index) to decompose the impact
factors of energy consumption of hotel from Jan. to Dec. in 2001. The
results indicate that the occupancy rate and unit area of revenue are the
main factors that can increase unit area of energy consumption, and the
unit revenue of energy consumption is the main factor to restrain the
growth of unit area of energy consumption. When the energy
consumption of hotel can appear abnormal, the hotel manager can
carry out energy saving management and control according to the
contribution value of impact factors.
Abstract: In this research, we propose to conduct diagnostic and
predictive analysis about the key factors and consequences of urban
population relocation. To achieve this goal, urban simulation models
extract the urban development trends as land use change patterns from
a variety of data sources. The results are treated as part of urban big
data with other information such as population change and economic
conditions. Multiple data mining methods are deployed on this data to
analyze nonlinear relationships between parameters. The result
determines the driving force of population relocation with respect to
urban sprawl and urban sustainability and their related parameters.
This work sets the stage for developing a comprehensive urban
simulation model for catering to specific questions by targeted users. It
contributes towards achieving sustainability as a whole.
Abstract: The paper deals with possibilities of increase train
capacity by using a new type of railway wagon. In the first part is
created a mathematical model to calculate the capacity of the train.
The model is based on the main limiting parameters of the train -
maximum number of axles per train, maximum gross weight of train,
maximum length of train and number of TEUs per one wagon. In the
second part is the model applied to four different model trains with
different composition of the train set and three different average
weights of TEU and a train consisting of a new type of wagons. The
result is to identify where the carrying capacity of the original trains
is higher, respectively less than a capacity of train consisting of a new
type of wagons.
Abstract: This work aims to investigate the structure–property
relationship in ternary nanocomposites consisting of polypropylene
as the matrix, polyamide 66 as the minor phase and treated nanoclay
DELLITE 67G as the reinforcement. All PP/PA66/Nanoclay systems
with polypropylene grafted maleic anhydride PP-g-MAH as a
compatibilizer were prepared via melt compounding and
characterized in terms of nanoclay content. Morphological structure
was investigated by scanning electron microscopy. The rheological
behavior of the nanocomposites was determined by various methods,
viz melt flow index (MFI) and parallel plate rheological
measurements. The PP/PP-g-MAH/PA66 nanocomposites showed a homogeneous
morphology supporting the compatibility improvement between PP,
PA66, and nanoclay. SEM results revealed the formation of
nanocomposites as the nanoclay was intercalated and exfoliated. In
the ternary nanocomposites, the rheological behavior showed that, the
complex viscosity is increased with increasing the nanoclay. The results showed that the use of nanoclay affects the variations
of storage modulus (G′), loss modulus (G″) and the melt elasticity.
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 aim of this study is to examine, through
experimentation in the laboratory, the supercritical flow in the
presence of an obstacle in a rectangular channel. The supercritical
regime in the whole hydraulic channel is achieved by adding a
convergent. We will observe the influence of the obstacle shape and
dimension on the characteristics of the supercritical flow, mainly the
free-surface elevation and the velocity profile. The velocity
measurements have been conducted with the one dimension laser
anemometry technique.
Abstract: Journal bearings used in IC engines are prone to premature
failures and are likely to fail earlier than the rated life due to
highly impulsive and unstable operating conditions and frequent
starts/stops. Vibration signature extraction and wear debris analysis
techniques are prevalent in industry for condition monitoring of
rotary machinery. However, both techniques involve a great deal of
technical expertise, time, and cost. Limited literature is available on
the application of these techniques for fault detection in reciprocating
machinery, due to the complex nature of impact forces that
confounds the extraction of fault signals for vibration-based analysis
and wear prediction. In present study, a simulation model was developed to investigate
the bearing wear behaviour, resulting because of different operating
conditions, to complement the vibration analysis. In current
simulation, the dynamics of the engine was established first, based on
which the hydrodynamic journal bearing forces were evaluated by
numerical solution of the Reynold’s equation. In addition, the
essential outputs of interest in this study, critical to determine wear
rates are the tangential velocity and oil film thickness between the
journals and bearing sleeve, which if not maintained appropriately,
have a detrimental effect on the bearing performance. Archard’s wear prediction model was used in the simulation to
calculate the wear rate of bearings with specific location information
as all determinative parameters were obtained with reference to crank
rotation. Oil film thickness obtained from the model was used as a
criterion to determine if the lubrication is sufficient to prevent contact
between the journal and bearing thus causing accelerated wear. A
limiting value of 1 μm was used as the minimum oil film thickness
needed to prevent contact. The increased wear rate with growing
severity of operating conditions is analogous and comparable to the
rise in amplitude of the squared envelope of the referenced vibration
signals. Thus on one hand, the developed model demonstrated its
capability to explain wear behaviour and on the other hand it also
helps to establish a co-relation between wear based and vibration
based analysis. Therefore, the model provides a cost effective and
quick approach to predict the impending wear in IC engine bearings
under various operating conditions.
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: The paper presents a method in which the expert
knowledge is applied to fuzzy inference model. Even a less
experienced person could benefit from the use of such a system, e.g.
urban planners, officials. The analysis result is obtained in a very
short time, so a large number of the proposed locations can also be
verified in a short time. The proposed method is intended for testing
of locations of car parks in a city. The paper shows selected examples
of locations of the P&R facilities in cities planning to introduce the
P&R. The analyses of existing objects are also shown in the paper
and they are confronted with the opinions of the system users, with
particular emphasis on unpopular locations. The results of the
analyses are compared to expert analysis of the P&R facilities
location that was outsourced by the city and the opinions about
existing facilities users that were expressed on social networking
sites. The obtained results are consistent with actual users’ feedback.
The proposed method proves to be good, but does not require the
involvement of a large experts team and large financial contributions
for complicated research. The method also provides an opportunity to
show the alternative location of P&R facilities. Although the results
of the method are approximate, they are not worse than results of
analysis of employed experts. The advantage of this method is ease of
use, which simplifies the professional expert analysis. The ability of
analyzing a large number of alternative locations gives a broader
view on the problem. It is valuable that the arduous analysis of the
team of people can be replaced by the model's calculation. According
to the authors, the proposed method is also suitable for
implementation on a GIS platform.