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: The statistical study has become indispensable for various fields of knowledge. Not any different, in Geotechnics the study of probabilistic and statistical methods has gained power considering its use in characterizing the uncertainties inherent in soil properties. One of the situations where engineers are constantly faced is the definition of a probability distribution that represents significantly the sampled data. To be able to discard bad distributions, goodness-of-fit tests are necessary. In this paper, three non-parametric goodness-of-fit tests are applied to a data set computationally generated to test the goodness-of-fit of them to a series of known distributions. It is shown that the use of normal distribution does not always provide satisfactory results regarding physical and behavioral representation of the modeled parameters.
Abstract: In this study, Brillouin Gain Spectrum (BGS) is
experimentally analyzed in the Brillouin Optical Time Domain
Reflectometry (BOTDR) and Brillouin Optical Time Domain
Analyzer (BOTDA). For this purpose, the signal level of the
microwave generator is varied and the effects of BGS are
investigated. In the setups, 20 km conventional single mode fiber is
used to both setups and laser wavelengths are selected around 1550
nm. To achieve best results, it can be used between 5 dBm to 15 dBm
signal level of microwave generator for BOTDA and BOTDR setups.
Abstract: In this paper, a linear mixed model which has two
random effects is broken up into two models. This thesis gets
the parameter estimation of the original model and an estimation’s
statistical qualities based on these two models. Then many important
properties are given by comparing this estimation with other general
estimations. At the same time, this paper proves the analysis of
variance estimate (ANOVAE) about σ2 of the original model is equal
to the least-squares estimation (LSE) about σ2 of these two models.
Finally, it also proves that this estimation is better than ANOVAE
under Stein function and special condition in some degree.
Abstract: The social logic of 'Sequina' slum area in Alexandria details the integral measure of space syntax at the room-level of twenty-building samples. The essence of spatial structure integrates the central 'visitor' domain with the 'living' frontage of the 'children' zone against the segregated privacy of the opposite 'parent' depth. Meanwhile, the multifunctioning of shallow rooms optimizes the integral 'visitor' structure through graph and visibility dimensions in contrast to the 'inhabitant' structure of graph-tails out of sight. Common theme of the layout integrity increases in compensation to the decrease of room visibility. Despite the 'pheno-type' of collective integration, the individual layouts observe 'geno-type' structure of spatial diversity per room adjoins. In this regard, the layout integrity alternates the cross-correlation of the 'kitchen & living' rooms with the 'inhabitant & visitor' domains of 'motherhood' dynamic structure. Moreover, the added 'grandparent' restructures the integral measure to become the deepest space, but opens to the 'living' of 'household' integrity. Some isomorphic layouts change the integral structure just through the 'balcony' extension of access, visual or ignored 'ringiness' of space syntax. However, the most integrated or segregated layouts invert the 'geno-type' into a shallow 'inhabitant' centrality versus the remote 'visitor' structure. Overview of the multivariate social logic of spatial integrity could never clarify without the micro-data analysis.
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: Background modeling and subtraction in video
analysis has been widely used as an effective method for moving
objects detection in many computer vision applications. Recently, a
large number of approaches have been developed to tackle different
types of challenges in this field. However, the dynamic background
and illumination variations are the most frequently occurred problems
in the practical situation. This paper presents a favorable two-layer
model based on codebook algorithm incorporated with local binary
pattern (LBP) texture measure, targeted for handling dynamic
background and illumination variation problems. More specifically,
the first layer is designed by block-based codebook combining with
LBP histogram and mean value of each RGB color channel. Because
of the invariance of the LBP features with respect to monotonic
gray-scale changes, this layer can produce block wise detection results
with considerable tolerance of illumination variations. The pixel-based
codebook is employed to reinforce the precision from the output of the
first layer which is to eliminate false positives further. As a result, the
proposed approach can greatly promote the accuracy under the
circumstances of dynamic background and illumination changes.
Experimental results on several popular background subtraction
datasets demonstrate very competitive performance compared to
previous models.
Abstract: Polymeric composites are being increasingly used as
repair material for repairing critical infrastructures such as building,
bridge, pressure vessel, piping and pipeline. Technique in repairing
damaged pipes is one of the major concerns of pipeline owners.
Considerable researches have been carried out on the repair of
corroded pipes using composite materials. This article attempts a
short review of the subject matter to provide insight into various
techniques used in repairing corroded pipes, focusing on a wide range
of composite repair systems. These systems including pre-cured
layered, flexible wet lay-up, pre-impregnated, split composite sleeve
and flexible tape systems. Both advantages and limitations of these
repair systems were highlighted. Critical technical aspects have been
discussed through the current standards and practices. Research gaps
and future study scopes in achieving more effective design
philosophy are also presented.
Abstract: Rapid developments in technology in the present age
have made it necessary for communities to follow technological
developments and adapt themselves to these developments. One of
the fields that are most rapidly affected by these developments is
undoubtedly education. Determination of the attitudes of preservice
teachers, who live in an age of technology and get ready to raise
future individuals, is of paramount importance both educationally and
professionally. The purpose of this study was to analyze attitudes of
preservice teachers towards technology and some variables that
predict these attitudes (gender, daily duration of internet use, and the
number of technical devices owned). 329 preservice teachers
attending the education faculty of a large university in central Turkey
participated, on a volunteer basis, in this study, where relational
survey model was used as the research method. Research findings
reveal that preservice teachers’ attitudes towards technology are
positive and at the same time, the attitudes of male preservice
teachers towards technology are more positive than their female
counterparts. As a result of the stepwise multiple regression analysis
where factors predicting preservice teachers’ attitudes towards
technology, it was found that duration of daily internet use was the
strongest predictor of attitudes towards technology.
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: The purpose of this study is to analyze the temporal
and spatial variability of thermal conditions in the Republic of
Armenia. The paper describes annual fluctuations in air temperature.
Research has been focused on case study region of Armenia and
surrounding areas, where long–term measurements and observations
of weather conditions have been performed within the National
Meteorological Service of Armenia and its surrounding areas. The
study contains yearly air temperature data recorded between 1961-
2012. Mann-Kendal test and the autocorrelation function were
applied to detect the change trend of annual mean temperature, as
well as other parametric and non-parametric tests searching to find
the presence of some breaks in the long term evolution of
temperature. The analysis of all records reveals a tendency mostly
towards warmer years, with increased temperatures especially in
valleys and inner basins. The maximum temperature increase is up to
1,5°C. Negative results have not been observed in Armenia. The
patterns of temperature change have been observed since the 1990’s
over much of the Armenian territory. The climate in Armenia was
influenced by global change in the last 2 decades, as results from the
methods employed within the study.
Abstract: River Hindon is an important river catering the
demand of highly populated rural and industrial cluster of western
Uttar Pradesh, India. Water quality of river Hindon is deteriorating at
an alarming rate due to various industrial, municipal and agricultural
activities. The present study aimed at identifying the pollution
sources and quantifying the degree to which these sources are
responsible for the deteriorating water quality of the river. Various
water quality parameters, like pH, temperature, electrical
conductivity, total dissolved solids, total hardness, calcium, chloride,
nitrate, sulphate, biological oxygen demand, chemical oxygen
demand, and total alkalinity were assessed. Water quality data
obtained from eight study sites for one year has been subjected to the
two multivariate techniques, namely, principal component analysis
and cluster analysis. Principal component analysis was applied with
the aim to find out spatial variability and to identify the sources
responsible for the water quality of the river. Three Varifactors were
obtained after varimax rotation of initial principal components using
principal component analysis. Cluster analysis was carried out to
classify sampling stations of certain similarity, which grouped eight
different sites into two clusters. The study reveals that the
anthropogenic influence (municipal, industrial, waste water and
agricultural runoff) was the major source of river water pollution.
Thus, this study illustrates the utility of multivariate statistical
techniques for analysis and elucidation of multifaceted data sets,
recognition of pollution sources/factors and understanding
temporal/spatial variations in water quality for effective river water
quality management.
Abstract: In the present work, forming limit diagrams and strain
distribution profile diagrams for extra deep drawing steel at room and
elevated temperatures have been determined experimentally by
conducting stretch forming experiments by using designed and
fabricated warm stretchforming tooling setup. With the help of
forming Limit Diagrams (FLDs) and strain, distribution profile
diagrams the formability of Extra Deep Drawing steel has been
analyzed and co-related with mechanical properties like strain
hardening COEFFICIENT (n) and normal anisotropy (r−). Mechanical
properties of EDD steel from room temperature to 4500C were
determined and discussed the impact of temperature on the properties
like work hardening exponent (n) anisotropy (r-) and strength
coefficient of the material. In addition, the fractured surfaces after
stretching have undergone the some metallurgical investigations and
attempt has been made to co-relate with the formability of EDD steel
sheets. They are co-related and good agreement with FLDs at various
temperatures.
Abstract: A physical model for guiding the wave in
photorefractive media is studied. Propagation of cos-Gaussian beam
as the special cases of sinusoidal-Gaussian beams in photorefractive
crystal is simulated numerically by the Crank-Nicolson method in
one dimension. Results show that the beam profile deforms as the
energy transfers from the center to the tails under propagation. This
simulation approach is of significant interest for application in optical
telecommunication. The results are presented graphically and
discussed.
Abstract: Green and renewable energy is getting extraordinary
consideration today, because of ecological concerns made by blazing
of fossil powers. Photovoltaic and wind power generation are the
basic decisions for delivering power in this respects. Producing
power by the sun based photovoltaic systems is known to the world,
yet control makers may get confounded to pick between on-grid and
off-grid systems. In this exploration work, an endeavor is made to
compare the off-grid (stand-alone) and on-grid (grid-connected)
frameworks. The work presents relative examination, between two
distinctive PV frameworks situated at V.V.P. Engineering College,
Rajkot. The first framework is 100 kW remain solitary and the
second is 60 kW network joined. The real-time parameters compared
are; output voltage, load current, power in-flow, power output,
performance ratio, yield factor, and capacity factor. The voltage
changes and the power variances in both frameworks are given
exceptional consideration and the examination is made between the
two frameworks to judge the focal points and confinements of both
the frameworks.
Abstract: A Friction stir welding tool is a critical component to
the success of the process. The tool typically consists of a rotating
round shoulder and a threaded cylindrical pin that heats the work
piece, mostly by friction, and moves the softened alloy around it to
form the joint. In this research work, an attempt has been made to
investigate the relationship between FSW variables mainly tool
profile, rotating speed, welding speed and the mechanical properties
(tensile strength, yield strength, percentage elongation, and micro
hardness) of friction stir welded aluminum alloy 5083 joints. From
the experimental details, it can be assessed that the joint produced by
using Triflute profile tool has contribute superior mechanical and
structural properties as compared to Tapered unthreaded & Threaded
tool for 1000rpm.
Abstract: In this paper, a prototype PEM fuel cell vehicle
integrated with a 1 kW air-blowing proton exchange membrane fuel
cell (PEMFC) stack as a main power sources has been developed for
a lightweight cruising vehicle. The test vehicle is equipped with a
PEM fuel cell system that provides electric power to a brushed DC
motor. This vehicle was designed to compete with industrial
lightweight vehicle with the target of consuming least amount of
energy and high performance. Individual variations in driving style
have a significant impact on vehicle energy efficiency and it is well
established from the literature. The primary aim of this study was to
assesses the power and fuel consumption of a hydrogen fuel cell
vehicle operating at three difference driving technique (i.e. 25 km/h
constant speed, 22-28 km/h speed range, 20-30 km/h speed range).
The goal is to develop the best driving strategy to maximize
performance and minimize fuel consumption for the vehicle system.
The relationship between power demand and hydrogen consumption
has also been discussed. All the techniques can be evaluated and
compared on broadly similar terms. Automatic intelligent controller
for driving prototype fuel cell vehicle on different obstacle while
maintaining all systems at maximum efficiency was used. The result
showed that 25 km/h constant speed was identified for optimal
driving with less fuel consumption.
Abstract: Online measurement of the product quality is a
challenging task in cement production, especially in the production of
Celitement, a novel environmentally friendly hydraulic binder. The
mineralogy and chemical composition of clinker in ordinary Portland
cement production is measured by X-ray diffraction (XRD) and
X-ray fluorescence (XRF), where only crystalline constituents can be
detected. But only a small part of the Celitement components can be
measured via XRD, because most constituents have an amorphous
structure. This paper describes the development of algorithms
suitable for an on-line monitoring of the final processing step of
Celitement based on NIR-data. For calibration intermediate products
were dried at different temperatures and ground for variable
durations. The products were analyzed using XRD and
thermogravimetric analyses together with NIR-spectroscopy to
investigate the dependency between the drying and the milling
processes on one and the NIR-signal on the other side. As a result,
different characteristic parameters have been defined. A short
overview of the Celitement process and the challenging tasks of the
online measurement and evaluation of the product quality will be
presented. Subsequently, methods for systematic development of
near-infrared calibration models and the determination of the final
calibration model will be introduced. The application of the model on
experimental data illustrates that NIR-spectroscopy allows for a quick
and sufficiently exact determination of crucial process parameters.