Abstract: This study estimates the seismic demands of tall
buildings with central symmetric setbacks by using nonlinear time
history analysis. Three setback structures, all 60-story high with
setback in three levels, are used for evaluation. The effects of
irregularities occurred by setback are evaluated by determination of
global-drift, story-displacement and story drift. Story-displacement is
modified by roof displacement and first story displacement and story
drift is modified by global drift. All results are calculated at the
center of mass and in x and y direction. Also the absolute values of
these quantities are determined. The results show that increasing of
vertical irregularities increases the global drift of the structure and
enlarges the deformations in the height of the structure. It is also
observed that the effects of geometry irregularity in the seismic
deformations of setback structures are higher than those of mass
irregularity.
Abstract: Flow blockages referring to the increase in flow are
being considered as a vital equipment for marine current energy
conversion. However, the shape of these devices will result in
extracted energy under the operation. The present work investigates
the effect of two configurations of a grating, convergent and
divergent that located upstream, to the water flow velocity. The flow
characteristics are studied by Computational Fluid Dynamic
simulation by using the ANSYS Fluent solver for these specified
arrangements of the grating. The results indicate that distinguished
characteristics of flow velocity between “convergent” and
“divergent” grating placements is up to 10% in confined conditions.
Furthermore, the velocity in case of convergent grating is higher
than that of divergent grating.
Abstract: This paper presents Finite Element Method (FEM) for
analyzing the internal responses generated in thin rectangular plates
with various edge conditions and rigidity conditions. Comparison has
been made between the FEM (ANSYS software) results for
displacement, stresses and moments generated with and without the
consideration of hole in plate and different aspect ratios. In the end
comparison for responses in plain and composite square plates has
been studied.
Abstract: In this paper, the author studied the possibilities of
using Rice Husk Ash (RHA) available in India; to produce concrete.
Experiments conducted with RHA obtained from West Bengal, India;
to replace cement partially to produce concrete of grade M10, M15,
M20, M25 and M30. The concrete produced in the laboratory by
replacing cement by 5%, 10%, 15%, 20%, 25% and 30% RHA.
Compressive strength tests carried out to determine the strength of
concrete. Cost analysis and comparison done to show the cost
effectiveness of RHA Concrete. Traditional uses of Rice Husk in
India pointed out and the advantages of using RHA in making
concrete highlighted. Suggestion provided regarding prospective
application of RHA concrete in India; which in turn will definitely
reduce the cost of concrete and environmental friendly due to
utilization of waste and replacement of Cement.
Abstract: Unmanned aircraft systems (UAS) are playing
increasingly prominent roles in defense programs and defense
strategies around the world. Technology advancements have
enabled the development of it to do many excellent jobs as
reconnaissance, surveillance, battle fighters, and communications
relays. Simulating a small unmanned aerial vehicle (SUAV)
dynamics and analyzing its behavior at the preflight stage is too
important and more efficient. The first step in the UAV design is
the mathematical modeling of the nonlinear equations of motion. .
In this paper, a survey with a standard method to obtain the full
non-linear equations of motion is utilized, and then the
linearization of the equations according to a steady state flight
condition (trimming) is derived. This modeling technique is
applied to an Ultrastick-25e fixed wing UAV to obtain the valued
linear longitudinal and lateral models. At the end the model is
checked by matching between the behavior of the states of the nonlinear
UAV and the resulted linear model with doublet at the
control surfaces.
Abstract: Future mobile networks following 5th generation will
be characterized by one thousand times higher gains in capacity;
connections for at least one hundred billion devices; user experience
capable of extremely low latency and response times. To be close to
the capacity requirements and higher reliability, advanced
technologies have been studied, such as multiple connectivity, small
cell enhancement, heterogeneous networking, and advanced
interference and mobility management. This paper is focused on the
multiple connectivity in heterogeneous cellular networks. We
investigate the performance of coverage and user throughput in several
deployment scenarios. Using the stochastic geometry approach, the
SINR distributions and the coverage probabilities are derived in case
of dual connection. Also, to compare the user throughput enhancement
among the deployment scenarios, we calculate the spectral efficiency
and discuss our results.
Abstract: Absorptive capacity generally facilitates the adoption
of innovation. How does this relationship change when economic
return is not the sole driver of innovation uptake? We investigate
whether absorptive capacity facilitates the adoption of green
innovation based on a survey of 79 construction companies in
Scotland. Based on the results of multiple regression analyses, we
confirm that existing knowledge utilisation (EKU), knowledge
building (KB) and external knowledge acquisition (EKA) are
significant predictors of green process GP), green administrative
(GA) and green technical innovation (GT), respectively. We discuss
the implications for theories of innovation adoption and knowledge
enhancement associated with environmentally-friendly practices.
Abstract: The main objective of aircraft aerodynamics is to
enhance the aerodynamic characteristics and maneuverability of the
aircraft. This enhancement includes the reduction in drag and stall
phenomenon. The airfoil which contains dimples will have
comparatively less drag than the plain airfoil. Introducing dimples on
the aircraft wing will create turbulence by creating vortices which
delays the boundary layer separation resulting in decrease of pressure
drag and also increase in the angle of stall. In addition, wake
reduction leads to reduction in acoustic emission. The overall
objective of this paper is to improve the aircraft maneuverability by
delaying the flow separation point at stall and thereby reducing the
drag by applying the dimple effect over the aircraft wing. This project
includes both computational and experimental analysis of dimple
effect on aircraft wing, using NACA 0018 airfoil. Dimple shapes of
Semi-sphere, hexagon, cylinder, square are selected for the analysis;
airfoil is tested under the inlet velocity of 30m/s and 60m/s at
different angle of attack (5˚, 10˚, 15˚, 20˚, and 25˚). This analysis
favors the dimple effect by increasing L/D ratio and thereby
providing the maximum aerodynamic efficiency, which provides the
enhanced performance for the aircraft.
Abstract: Starting from nonlocal continuum mechanics, a
thermodynamically new nonlocal model of Euler-Bernoulli
nanobeams is provided. The nonlocal variational formulation is
consistently provided and the governing differential equation for
transverse displacement is presented. Higher-order boundary
conditions are then consistently derived. An example is contributed in
order to show the effectiveness of the proposed model.
Abstract: The seismic responses of steel buildings with semirigid
post-tensioned connections (PC) are estimated and compared
with those of steel buildings with typical rigid (welded) connections
(RC). The comparison is made in terms of global and local response
parameters. The results indicate that the seismic responses in terms of
interstory shears, roof displacements, axial load and bending
moments are smaller for the buildings with PC connection. The
difference is larger for global than for local parameters, which in turn
varies from one column location to another. The reason for this
improved behavior is that the buildings with PC dissipate more
hysteretic energy than those with RC. In addition, unlike the case of
buildings with WC, for the PC structures the hysteretic energy is
mostly dissipated at the connections, which implies that structural
damage in beams and columns is not significant. According to these
results, steel buildings with PC are a viable option in high seismicity
areas because of their smaller response and self-centering connection
capacity as well as the fact that brittle failure is avoided.
Abstract: This study aims to investigate the possibility of crime
prevention through CCTV by analyzing the appropriateness of the
CCTV location, whether it is installed in the hotspot of crime-prone
areas, and exploring the crime prevention effect and transition effect.
The real crime and CCTV locations of case city were converted into
the spatial data by using GIS. The data was analyzed by hotspot
analysis and weighted displacement quotient (WDQ). As study
methods, it analyzed existing relevant studies for identifying the trends
of CCTV and crime studies based on big data from 1800 to 2014 and
understanding the relation between CCTV and crime. Second, it
investigated the current situation of nationwide CCTVs and analyzed
the guidelines of CCTV installation and operation to draw attention to
the problems and indicating points of CCTV use. Third, it investigated
the crime occurrence in case areas and the current situation of CCTV
installation in the spatial aspects, and analyzed the appropriateness and
effectiveness of CCTV installation to suggest a rational installation of
CCTV and the strategic direction of crime prevention. The results
demonstrate that there was no significant effect in the installation of
CCTV on crime prevention in the case area. This indicates that CCTV
should be installed and managed in a more scientific way reflecting
local crime situations. In terms of CCTV, the methods of spatial
analysis such as GIS, which can evaluate the installation effect, and the
methods of economic analysis like cost-benefit analysis should be
developed. In addition, these methods should be distributed to local
governments across the nation for the appropriate installation of
CCTV and operation. This study intended to find a design guideline of
the optimum CCTV installation. In this regard, this study is
meaningful in that it will contribute to the creation of a safe city.
Abstract: Concrete is found to undergo degradation when
subjected to elevated temperatures and loose substantial amount of its
strength. The loss of strength in concrete is mainly attributed to
decomposition of C-S-H and release of physically and chemically
bound water, which begins when the exposure temperature exceeds
100°C. When such a concrete comes in contact with moisture, the
cement paste is found rehydrate and considerable amount of strength
lost is found to recover. This paper presents results of an
experimental program carried out to investigate the effect of recuring
on strength gain of OPC concrete specimens subjected to elevated
temperatures from 200°C to 800°C, which were subjected to
retention time of two hours and four hours at the designated
temperature. Strength recoveries for concrete subjected to 7
designated elevated temperatures are compared. It is found that the
efficacy of recuring as a measure of strength recovery reduces with
increase in exposure temperature.
Abstract: In reference to the legal state in the Thai legal system,
most people understand the minor principles of the legal state form,
which are the principles that can be explained and understood easily
and the results can be seen clearly, especially in the legitimacy of
administrative acts. Therefore, there is no awareness of justice, which
is the fundamental value of Thai law. The legitimacy of administrative
acts requires the administration to adhere to the constitution and
legislative laws in enforcement of the laws. If it appears that the
administrative acts are illegitimate, the administrative court, as the
court of justice, will revoke those acts as if they had never been set in
the legal system, this will affect people’s trust as they are unaware as
to whether the administrative acts that appoint their lives are
legitimate or not. Regarding the revocation of administrative orders
by the administrative court as if those orders had never existed, the
common individual surely cannot be expected to comprehend the
security of their juristic position. Therefore, the legal state does not
require a revocation of the government’s acts to terminate its legal
results merely because those acts are illegitimate, but there should be
considerations and realizations regarding the “The Principle of the
Protection of Legitimate Expectation,” which is a minor principle in
the legal state’s content that focuses on supporting and protecting
legitimate expectations of the juristic position of an individual and
maintaining justice, which is the fundamental value of Thai law.
Abstract: Cement concrete is a complex mixture of different
materials. Behaviour of concrete depends on its mix proportions and
constituents when it is subjected to elevated temperatures. Principal
effects due to elevated temperatures are loss in compressive strength,
loss in weight or mass, change in colour and spall of concrete. The
experimental results of normal concrete and high strength concrete
subjected elevated temperatures at 200°C, 400°C, 600°C, and 800°C
and different cooling regimes viz. air cooling, water quenching on
different grade of concrete are reported in this paper.
Abstract: The objective of this study was to assess whether
living in proximity to a roofing fiber cement factory in southern
Thailand was associated with physical, mental, social, and spiritual
health domains measured in a self-reported health risk assessment
(HRA) questionnaire. A cross-sectional study was conducted among
community members divided into two groups: near population (living
within 0-2km of factory) and far population (living within 2-5km of
factory) (N=198). A greater proportion of those living far from the
factory (65.34%) reported physical health problems than the near
group (51.04%) (p =0.032). This study has demonstrated that the near
population group had higher proportion of participants with positive
ratings on mental assessment (30.34%) and social health impacts
(28.42%) than far population group (10.59% and 16.67%,
respectively) (p
Abstract: This paper presents a methodology using
Gravitational Search Algorithm for optimal placement of Phasor
Measurement Units (PMUs) in order to achieve complete
observability of the power system. The objective of proposed
algorithm is to minimize the total number of PMUs at the power
system buses, which in turn minimize installation cost of the PMUs.
In this algorithm, the searcher agents are collection of masses which
interact with each other using Newton’s laws of gravity and motion.
This new Gravitational Search Algorithm based method has been
applied to the IEEE 14-bus, IEEE 30-bus and IEEE 118-bus test
systems. Case studies reveal optimal number of PMUs with better
observability by proposed method.
Abstract: Sustainability and eco-friendly requirement of
engineering materials are sort for in recent times, thus giving rise to
the development of bio-composites. However, the natural fibres to
matrix interface interactions remain a key issue in getting the desired
mechanical properties from such composites. Treatment of natural
fibres is essential in improving matrix to filler adhesion, hence
improving its mechanical properties. In this study, investigations
were carried out to determine the effect of sodium hydroxide
treatment on the tensile, flexural, impact and hardness properties of
crushed and uncrushed Luffa cylindrica fibre reinforced recycled low
density polyethylene composites. The LC (Luffa cylindrica) fibres
were treated with 0%, 2%, 4%, 6%, 8% and 10% wt. sodium
hydroxide (NaOH) concentrations for a period of 24 hours under
room temperature conditions. A formulation ratio of 80/20 g (matrix
to reinforcement) was maintained for all developed samples. Analysis
of the results showed that the uncrushed luffa fibre samples gave
better mechanical properties compared with the crushed luffa fibre
samples. The uncrushed luffa fibre composites had a maximum
tensile and flexural strength of 7.65 MPa and 17.08 Mpa respectively
corresponding to a young modulus and flexural modulus of 21.08
MPa and 232.22 MPa for the 8% and 4% wt. NaOH concentration
respectively. Results obtained in the research showed that NaOH
treatment with the 8% NaOH concentration improved the mechanical
properties of the LC fibre reinforced composites when compared with
other NaOH treatment concentration values.
Abstract: Total hip replacement had been one of the most
successful operations in hip arthritis surgery. The purpose of this
research had been to develop a dynamic hip contact of Thai femoral
bone to analyze the stress distribution on the implant and the strain
distribution on the bone model under daily activities and compared
with the static load simulation. The results showed the different of
maximum von Mises stress 0.14 percent under walking and 0.03
percent under climbing stair condition and the different of equivalent
total strain 0.52 percent under walking and 0.05 percent under
climbing stair condition. The muscular forces should be evaluated
with dynamic condition to reduce the maximum von Mises stress and
equivalent total strain.
Abstract: This work reports the potential of using Palm Kernel
(PK) ash and shell as a partial substitute for Portland Cement (PC)
and coarse aggregate in the development of mortar and concrete. PK
ash and shell are agro-waste materials from palm oil mills, the
disposal of PK ash and shell is an environmental problem of concern.
The PK ash has pozzolanic properties that enables it as a partial
replacement for cement and also plays an important role in the
strength and durability of concrete, its use in concrete will alleviate
the increasing challenges of scarcity and high cost of cement. In order
to investigate the PC replacement potential of PK ash, three types of
PK ash were produced at varying temperature (350-750C) and they
were used to replace up to 50% PC. The PK shell was used to replace
up to 100% coarse aggregate in order to study its aggregate
replacement potential. The testing programme included material
characterisation, the determination of compressive strength, tensile
splitting strength and chemical durability in aggressive sulfatebearing
exposure conditions. The 90 day compressive results showed
a significant strength gain (up to 26.2 N/mm2). The Portland cement
and conventional coarse aggregate has significantly higher influence
in the strength gain compared to the equivalent PK ash and PK shell.
The chemical durability results demonstrated that after a prolonged
period of exposure, significant strength losses in all the concretes
were observed. This phenomenon is explained, due to lower change
in concrete morphology and inhibition of reaction species and the
final disruption of the aggregate cement paste matrix.
Abstract: A numerical study of natural convection heat transfer
in water filled cavity has been examined in 3-Dfor single phase liquid
cooling system by using an array of parallel plate fins mounted to one
wall of a cavity. The heat generated by a heat source represents a
computer CPU with dimensions of 37.5∗37.5mm mounted on
substrate. A cold plate is used as a heat sink installed on the opposite
vertical end of the enclosure. The air flow inside the computer case is
created by an exhaust fan. A turbulent air flow is assumed and k-ε
model is applied. The fins are installed on the substrate to enhance
the heat transfer. The applied power energy range used is between 15
- 40W. In order to determine the thermal behaviour of the cooling
system, the effect of the heat input and the number of the parallel
plate fins are investigated. The results illustrate that as the fin number
increases the maximum heat source temperature decreases. However,
when the fin number increases to critical value the temperature start
to increase due to the fins are too closely spaced and that cause the
obstruction of water flow. The introduction of parallel plate fins
reduces the maximum heat source temperature by 10% compared to
the case without fins. The cooling system maintains the maximum
chip temperature at 64.68°C when the heat input was at 40W that is
much lower than the recommended computer chips limit temperature
of no more than 85°C and hence the performance of the CPU is
enhanced.