Abstract: Aerated concrete is a load bearing construction
material, which has high heat insulation parameters. Walls can be
erected from aerated concrete masonry constructions and in perfect
circumstances additional heat insulation is not required. The most
common problem in aerated concrete heat insulation properties is the
humidity distribution throughout the cross section of the masonry
elements as well as proper and conducted drying process of the
aerated concrete construction because only dry aerated concrete
masonry constructions can reach high heat insulation parameters.
In order to monitor drying process of the masonry and detect
humidity distribution throughout the cross section of aerated concrete
masonry construction application of electrical impedance
spectrometry is applied. Further test results and methodology of this
non-destructive testing method is described in this paper.
Abstract: An algorithm is a well-defined procedure that takes
some input in the form of some values, processes them and gives the
desired output. It forms the basis of many other algorithms such as
searching, pattern matching, digital filters etc., and other applications
have been found in database systems, data statistics and processing,
data communications and pattern matching. This paper introduces
algorithmic “Enhanced Bidirectional Selection” sort which is
bidirectional, stable. It is said to be bidirectional as it selects two
values smallest from the front and largest from the rear and assigns
them to their appropriate locations thus reducing the number of
passes by half the total number of elements as compared to selection
sort.
Abstract: In this paper, a coupled damage effect in the
instability of a composite rotor is presented, under dynamic loading
response in the harmonic analysis condition. The analysis of the
stress which operates the rotor is done. Calculations of different
energies and the virtual work of the aerodynamic loads from the rotor
blade are developed. The use of the composite material for the rotor
offers a good stability.
Numerical calculations on the model developed prove that the
damage effect has a negative effect on the stability of the rotor.
The study of the composite rotor in transient system allowed
determining the vibratory responses due to various excitations.
Abstract: Regardless of the manufacturing process used,
subtractive or additive, material, purpose and application, produced
components are conventionally solid mass with more or less complex
shape depending on the production technology selected. Aspects
such as reducing the weight of components, associated with the low
volume of material required and the almost non-existent material
waste, speed and flexibility of production and, primarily, a high
mechanical strength combined with high structural performance, are
competitive advantages in any industrial sector, from automotive,
molds, aviation, aerospace, construction, pharmaceuticals, medicine
and more recently in human tissue engineering. Such features,
properties and functionalities are attained in metal components
produced using the additive technique of Rapid Prototyping from
metal powders commonly known as Selective Laser Melting (SLM),
with optimized internal topologies and varying densities. In order to
produce components with high strength and high structural and
functional performance, regardless of the type of application, three
different internal topologies were developed and analyzed using
numerical computational tools. The developed topologies were
numerically submitted to mechanical compression and four point
bending testing. Finite Element Analysis results demonstrate how
different internal topologies can contribute to improve mechanical
properties, even with a high degree of porosity relatively to fully
dense components. Results are very promising not only from the
point of view of mechanical resistance, but especially through the
achievement of considerable variation in density without loss of
structural and functional high performance.
Abstract: This paper focuses on the dynamic behavior of
reinforced concrete (RC) slabs. Therefore, the theoretical modal
analysis was performed using two different types of boundary
conditions. Modal analysis method is the most important dynamic
analyses. The analysis would be modal case when there is no external
force on the structure. By using this method in this paper, the effects
of freely and simply supported boundary conditions on the
frequencies and mode shapes of RC square slabs are studied. ANSYS
software was employed to derive the finite element model to
determine the natural frequencies and mode shapes of the slabs.
Then, the obtained results through numerical analysis (finite element
analysis) would be compared with the exact solution. The main goal
of the research study is to predict how the boundary conditions
change the behavior of the slab structures prior to performing
experimental modal analysis. Based on the results, it is concluded
that simply support boundary condition has obvious influence to
increase the natural frequencies and change the shape of the mode
when it is compared with freely supported boundary condition of
slabs. This means that such support conditions have the direct
influence on the dynamic behavior of the slabs. Thus, it is suggested
to use free-free boundary condition in experimental modal analysis to
precisely reflect the properties of the structure. By using free-free
boundary conditions, the influence of poorly defined supports is
interrupted.
Abstract: The Lean Environmental Management Integration
System (LEMIS) framework development is integration between lean
core element and ISO 14001. The curiosity on the relationship
between continuous improvement and sustainability of lean
implementation has influenced this study toward LEMIS.
Characteristic of ISO 14001 standard clauses and core elements of
lean principles are explored from past studies and literature reviews.
Survey was carried out on ISO 14001 certified companies to examine
continual improvement by implementing the ISO 14001 standard.
The study found that there is a significant and positive relationship
between Lean Principles: value, value stream, flow, pull and
perfection with the ISO 14001 requirements. LEMIS is significant to
support the continuous improvement and sustainability. The
integration system can be implemented to any manufacturing
company. It gives awareness on the importance on why organizations
need to sustain its environmental management system. In the
meantime, the lean principle can be adapted in order to streamline
daily activities of the company. Throughout the study, it had proven
that there is no sacrifice or trade-off between lean principles with ISO
14001 requirements. The framework developed in the study can be
further simplified in the future, especially the method of crossing
each sub requirements of ISO 14001 standard with the core elements
of Lean principles in this study.
Abstract: Yttrium oxide (Y2O3) films have been successfully
deposited with yttrium-ethylenediamine tetraacetic acid (EDTA·Y·H)
complexes prepared by various milling techniques. The effects of the
properties of the EDTA·Y·H complex on the properties of the
deposited Y2O3 films have been analyzed. Seven different types of the
raw EDTA·Y·H complexes were prepared by various commercial
milling techniques such as ball milling, hammer milling, commercial
milling, and mortar milling. The milled EDTA·Y·H complexes
exhibited various particle sizes and distributions, depending on the
milling method. Furthermore, we analyzed the crystal structure,
morphology and elemental distribution profile of the metal oxide films
deposited on stainless steel substrate with the milled EDTA·Y·H
complexes. Depending on the milling technique, the flow properties of
the raw powders differed. The X-ray diffraction pattern of all the
samples revealed the formation of Y2O3 crystalline phase, irrespective
of the milling technique. Of all the different milling techniques, the
hammer milling technique is considered suitable for fabricating dense
Y2O3 films.
Abstract: In recent decades with the development of technology
and lack of food sources, sewage sludge in production of human
foods is inevitable. Various sources of municipal and industrial
sewage sludge that is produced can provide the requirement of plant
nutrients. Soils in arid, semi-arid climate of central Iran that most
affected by water drainage, iron and zinc deficiencies, using of
sewage sludge is helpful. Therefore, the aim of this study is
investigation of sewage sludge and manure application on Ni, Pb and
Cd uptake by Savory. An experiment in a randomized complete block
design with three replications was performed. Sewage sludge
treatments consisted of four levels, control, 15, 30, 80 tons per
hectares; the manure was used in four levels of control, 20, 40 and 80
tons per hectare. Results showed that the wet and dry weights was not
affected by sewage sludge using, while, manure has significant effect
on them. The effect of sewage sludge on the cadmium and lead
concentrations were significant. Interactions of sewage sludge and
manure on dry weight values were not significant. Compare mean
analysis showed that increasing the amount of sewage sludge had no
significant effect on cadmium concentration and it reduced when
sewage sludge usage increased. This is probably due to increased
plant growth and reduced concentrations of these elements in the
plant.
Abstract: This paper reports the numerical and experimental
performances of Double Glass Wall are investigated. Two
configurations were considered namely, the Double Clear Glass Wall
(DCGW) and the Double Translucent Glass Wall (DTGW). The
coupled governing equations as well as boundary conditions are
solved using the finite element method (FEM) via COMSOLTM
Multiphysics. Temperature profiles and flow field of the DCGW and
DTGW are reported and discussed. Different constant heat fluxes
were considered as 400 and 800 W.m-2 the corresponding initial
condition temperatures were 30.5 and 38.5ºC respectively. The
results show that the simulation results are in agreement with the
experimental data. Conclusively, the model considered in this study
could reasonable be used simulate the thermal and ventilation
performance of the DCGW and DTGW configurations.
Abstract: Nowadays, the Web has become one of the most
pervasive platforms for information change and retrieval. It collects
the suitable and perfectly fitting information from websites that one
requires. Data mining is the form of extracting data’s available in the
internet. Web mining is one of the elements of data mining
Technique, which relates to various research communities such as
information recovery, folder managing system and simulated
intellects. In this Paper we have discussed the concepts of Web
mining. We contain generally focused on one of the categories of
Web mining, specifically the Web Content Mining and its various
farm duties. The mining tools are imperative to scanning the many
images, text, and HTML documents and then, the result is used by
the various search engines. We conclude by presenting a comparative
table of these tools based on some pertinent criteria.
Abstract: The usage of e-health facilities is seen to be the first
priority by the Libyan government. As such this paper focuses on
how the key factors or elements of working size in terms of
technological availability, structural environment, and other
competence-related matters may affect nurses’ sharing of knowledge
in e-health. Hence, this paper investigates learning readiness
assessment to raise e-health for Libyan regional hospitals by using ehealth
services in nursing education.
Abstract: This paper discusses the potential benefits of an
interactive multimedia information representation in enhancing
students’ critical thinking aligned with history reasoning in learning
history amongst Secondary School students in Malaysia. Two modes
of multimedia information representation were implemented;
chronologic and thematic information representations. A qualitative
study of an unstructured interview was conducted among two history
teachers, one history education lecturer, two i-think experts, and five
students from Form Four secondary school. The interview was to
elicit their opinions on the implementation of thinking maps and
interactive multimedia information representation in history learning.
The key elements of the interactive multimedia (e.g. multiple media,
user control, interactivity and use of timelines and concept maps)
were then considered to improve the learning process. Findings of the
preliminary investigation reveal that the interactive multimedia
information representations have the potential benefits to be
implemented as an instructional resource in enhancing students’
higher order thinking skills (HOTs). This paper concludes by giving
suggestions for future work.
Abstract: Two micromechanical models for 3D smart composite
with embedded periodic or nearly periodic network of generally
orthotropic reinforcements and actuators are developed and applied to
cubic structures with unidirectional orientation of constituents.
Analytical formulas for the effective piezothermoelastic coefficients
are derived using the Asymptotic Homogenization Method (AHM).
Finite Element Analysis (FEA) is subsequently developed and used
to examine the aforementioned periodic 3D network reinforced smart
structures. The deformation responses from the FE simulations are
used to extract effective coefficients. The results from both
techniques are compared. This work considers piezoelectric materials
that respond linearly to changes in electric field, electric
displacement, mechanical stress and strain and thermal effects. This
combination of electric fields and thermo-mechanical response in
smart composite structures is characterized by piezoelectric and
thermal expansion coefficients. The problem is represented by unitcell
and the models are developed using the AHM and the FEA to
determine the effective piezoelectric and thermal expansion
coefficients. Each unit cell contains a number of orthotropic
inclusions in the form of structural reinforcements and actuators.
Using matrix representation of the coupled response of the unit cell,
the effective piezoelectric and thermal expansion coefficients are
calculated and compared with results of the asymptotic
homogenization method. A very good agreement is shown between
these two approaches.
Abstract: The biosynthesis of nanoparticles by microorganisms,
on the contrary to chemical synthesis, is an environmentally-friendly
process which has low energy requirements. In this investigation, we
used the microorganism Geobacillus wiegelii, strain GWE1, an
aerobic thermophile belonging to genus Geobacillus, isolated from a
drying oven. This microorganism has the ability to reduce selenite
evidenced by the change of color from colorless to red in the culture.
Elemental analysis and composition of the particles were verified
using transmission electron microscopy and energy-dispersive X-ray
analysis. The nanoparticles have a defined spherical shape and a
selenium elemental state. Previous experiments showed that the
presence of the whole microorganism for the reduction of selenite
was not necessary. The results strongly suggested that an intracellular
NADPH/NADH-dependent reductase mediates selenium
nanoparticles synthesis under aerobic conditions. The enzyme was
purified and identified by mass spectroscopy MALDI-TOF TOF
technique. The enzyme is a 1-pyrroline-5-carboxylate dehydrogenase.
Histograms of nanoparticles sizes were obtained. Size distribution
ranged from 40-160 nm, where 70% of nanoparticles have less than
100 nm in size. Spectroscopic analysis showed that the nanoparticles
are composed of elemental selenium. To analyse the effect of pH in
size and morphology of nanoparticles, the synthesis of them was
carried out at different pHs (4.0, 5.0, 6.0, 7.0, 8.0). For
thermostability studies samples were incubated at different
temperatures (60, 80 and 100 ºC) for 1 h and 3 h. The size of all
nanoparticles was less than 100 nm at pH 4.0; over 50% of
nanoparticles have less than 100 nm at pH 5.0; at pH 6.0 and 8.0 over
90% of nanoparticles have less than 100 nm in size. At neutral pH
(7.0) nanoparticles reach a size around 120 nm and only 20% of them
were less than 100 nm. When looking at temperature effect,
nanoparticles did not show a significant difference in size when they
were incubated between 0 and 3 h at 60 ºC. Meanwhile at 80 °C the
nanoparticles suspension lost its homogeneity. A change in size was
observed from 0 h of incubation at 80ºC, observing a size range
between 40-160 nm, with 20% of them over 100 nm. Meanwhile
after 3 h of incubation at size range changed to 60-180 nm with 50%
of them over 100 nm. At 100 °C the nanoparticles aggregate forming
nanorod structures. In conclusion, these results indicate that is
possible to modulate size and shape of biologically synthesized
nanoparticles by modulating pH and temperature.
Abstract: South Africa has some regions which are susceptible
to moderate seismic activity. A peak ground acceleration of between
0.1g and 0.15g can be expected in the southern parts of the Western
Cape. Unreinforced Masonry (URM) is commonly used as a
construction material for 2 to 5 storey buildings in underprivileged
areas in and around Cape Town. URM is typically regarded as the
material most vulnerable to damage when subjected to earthquake
excitation. In this study, a three-storey URM building was analysed
by applying seven earthquake time-histories, which can be expected
to occur in South Africa using a finite element approach.
Experimental data was used to calibrate the in- and out-of-plane
stiffness of the URM. The results indicated that tensile cracking of
the in-plane piers was the dominant failure mode. It is concluded that
URM buildings of this type are at risk of failure especially if
sufficient ductility is not provided. The results also showed that
connection failure must be investigated further.
Abstract: Pavement surface unevenness plays a pivotal role on
roughness index of road which affects on riding comfort ability.
Comfort ability refers to the degree of protection offered to vehicle
occupants from uneven elements in the road surface. So, it is
preferable to have a lower roughness index value for a better riding
quality of road users. Roughness is generally defined as an
expression of irregularities in the pavement surface which can be
measured using different equipments like MERLIN, Bump integrator,
Profilometer etc. Among them Bump Integrator is quite simple and
less time consuming in case of long road sections. A case study is
conducted on low volume roads in West District in Tripura to
determine roughness index (RI) using Bump Integrator at the
standard speed of 32 km/h. But it becomes too tough to maintain the
requisite standard speed throughout the road section. The speed of
Bump Integrator (BI) has to lower or higher in some distinctive
situations. So, it becomes necessary to convert these roughness index
values of other speeds to the standard speed of 32 km/h. This paper
highlights on that roughness index conversional model. Using SPSS
(Statistical Package of Social Sciences) software a generalized
equation is derived among the RI value at standard speed of 32 km/h
and RI value at other speed conditions.
Abstract: An investigation into the effect of countersunk depth,
plate thickness, countersunk angle and plate width on the stress
concentration around countersunk hole is carried out with the help of
finite element analysis. The variation of stress concentration with
respect to these parameters is studied for three types of loading viz.
uniformly distributed load, uniformly varying load and functionally
distributed load. The results of the finite element analysis are
interpreted and some conclusions are drawn. The distribution of
stress concentration around countersunk hole in isotropic plates
simply supported at all the edges is found similar and is independent
of loading. The maximum stress concentration also occurs at a
particular point irrespective of the loading conditions.
Abstract: Present study is aimed on the cutting process of circular
cross-section rods where the fracture is used to separate one rod
into two pieces. Incorporating the phenomenological ductile fracture
model into the explicit formulation of finite element method, the
process can be analyzed without the necessity of realizing too many
real experiments which could be expensive in case of repetitive
testing in different conditions. In the present paper, the steel AISI
1045 was examined and the tensile tests of smooth and notched
cylindrical bars were conducted together with biaxial testing of the
notched tube specimens to calibrate material constants of selected
phenomenological ductile fracture models. These were implemented
into the Abaqus/Explicit through user subroutine VUMAT and used
for cutting process simulation. As the calibration process is based
on variables which cannot be obtained directly from experiments,
numerical simulations of fracture tests are inevitable part of the
calibration. Finally, experiments regarding the cutting process were
carried out and predictive capability of selected fracture models is
discussed. Concluding remarks then make the summary of gained
experience both with the calibration and application of particular
ductile fracture criteria.
Abstract: In the present work, the finite element formulation for
the investigation of the effects of a localized interfacial degeneration
on the dynamic behavior of the [90°/0°] laminated composite plate
employing the state-space technique is performed. The stiffness of
the laminate is determined by assembling the stiffnesses of subelements.
This includes an introduction of an interface layer adopting
the virtually zero-thickness formulation to model the interfacial
degeneration. Also, the kinematically consistent mass matrix and
proportional damping have been formulated to complete the free
vibration governing expression. To simulate the interfacial
degeneration of the laminate, the degenerated areas are defined from
the center propagating outwards in a localized manner. It is found
that the natural frequency, damped frequency and damping ratio of
the plate decreases as the degenerated area of the interface increases.
On the contrary, the loss factor increases correspondingly.
Abstract: The substantial similarity of fatigue mechanism in a
new test rig for rolling contact fatigue (RCF) has been investigated. A
new reduced-scale test rig is designed to perform controlled RCF
tests in wheel-rail materials. The fatigue mechanism of the rig is
evaluated in this study using a combined finite element-fatigue
prediction approach. The influences of loading conditions on fatigue
crack initiation have been studied. Furthermore, the effects of some
artificial defects (squat-shape) on fatigue lives are examined. To
simulate the vehicle-track interaction by means of the test rig, a threedimensional
finite element (FE) model is built up. The nonlinear
material behaviour of the rail steel is modelled in the contact
interface. The results of FE simulations are combined with the critical
plane concept to determine the material points with the greatest
possibility of fatigue failure. Based on the stress-strain responses, by
employing of previously postulated criteria for fatigue crack initiation
(plastic shakedown and ratchetting), fatigue life analysis is carried
out. The results are reported for various loading conditions and
different defect sizes. Afterward, the cyclic mechanism of the test rig
is evaluated from the operational viewpoint. The results of fatigue
life predictions are compared with the expected number of cycles of
the test rig by its cyclic nature. Finally, the estimative duration of the
experiments until fatigue crack initiation is roughly determined.