Abstract: Road signs are the elements of roads with a lot of
influence in driver-s behavior. So that signals can fulfill its function,
they must overcome visibility and durability requirements,
particularly needed at night, when the coefficient of retroreflection
becomes a decisive factor in ensuring road safety. Accepting that the
visibility of the signage has implications for people-s safety, we
understand the importance to fulfill its function: to foster the highest
standards of service and safety in drivers. The usual conditions of
perception of any sign are determined by: age of the driver, reflective
material, luminosity, vehicle speed and emplacement. In this way,
this paper evaluates the different signals to increase the safety road.
Abstract: The dental composites are preferably used as filling
materials due to their esthetic appearances. Nevertheless one of the
major problems, during the application of the dental composites, is
shape change named as “polymerisation shrinkage" affecting clinical
success of the dental restoration while photo-polymerisation.
Polymerisation shrinkage of composites arises basically from the
formation of a polymer due to the monomer transformation which
composes of an organic matrix phase. It was sought, throughout this
study, to detect and evaluate the structural polymerisation shrinkage
of prepared dental composites in order to optimize the effects of
various fillers included in hydroxyapatite (HA)-reinforced dental
composites and hence to find a means to modify the properties of
these dental composites prepared with defined parameters. As a
result, the shrinkage values of the experimental dental composites
were decreased by increasing the filler content of composites and the
composition of different fillers used had effect on the shrinkage of
the prepared composite systems.
Abstract: Virtual Assembly (VA) is one of the key technologies
in advanced manufacturing field. It is a promising application of
virtual reality in design and manufacturing field. It has drawn much
interest from industries and research institutes in the last two decades.
This paper describes a process for integrating an interactive Virtual
Reality-based assembly simulation of a digital mockup with the
CAD/CAM infrastructure. The necessary hardware and software
preconditions for the process are explained so that it can easily be
adopted by non VR experts. The article outlines how assembly
simulation can improve the CAD/CAM procedures and structures;
how CAD model preparations have to be carried out and which
virtual environment requirements have to be fulfilled. The issue of
data transfer is also explained in the paper. The other challenges and
requirements like anti-aliasing and collision detection have also been
explained. Finally, a VA simulation has been carried out for a ball
valve assembly and a car door assembly with the help of Vizard
virtual reality toolkit in a semi-immersive environment and their
performance analysis has been done on different workstations to
evaluate the importance of graphical processing unit (GPU) in the
field of VA.
Abstract: E-learning is not restricted to the use of new technologies for the online content, but also induces the adoption of new approaches to improve the quality of education. This quality depends on the ability of these approaches (technical and pedagogical) to provide an adaptive learning environment. Thus, the environment should include features that convey intentions and meeting the educational needs of learners by providing a customized learning path to acquiring a competency concerned In our proposal, we believe that an individualized learning path requires knowledge of the learner. Therefore, it must pass through a personalization of diagnosis to identify precisely the competency gaps to fill, and reduce the cognitive load To personalize the diagnosis and pertinently measure the competency gap, we suggest implementing the formative assessment in the e-learning environment and we propose the introduction of a pre-regulation process in the area of formative assessment, involving its individualization and implementation in e-learning.
Abstract: Post cracking behavior and load –bearing capacity of
the steel fiber reinforced high-strength concrete (SFRHSC) are
dependent on the number of fibers are crossing the weakest crack
(bridged the crack) and their orientation to the crack surface. Filling
the mould by SFRHSC, fibers are moving and rotating with the
concrete matrix flow till the motion stops in each internal point of the
concrete body. Filling the same mould from the different ends
SFRHSC samples with the different internal structures (and different
strength) can be obtained. Numerical flow simulations (using Newton
and Bingham flow models) were realized, as well as single fiber
planar motion and rotation numerical and experimental investigation
(in viscous flow) was performed. X-ray pictures for prismatic
samples were obtained and internal fiber positions and orientations
were analyzed. Similarly fiber positions and orientations in cracked
cross-section were recognized and were compared with numerically
simulated. Structural SFRHSC fracture model was created based on
single fiber pull-out laws, which were determined experimentally.
Model predictions were validated by 15x15x60cm prisms 4 point
bending tests.
Abstract: We numerically study the three-dimensional
magnetohydrodynamics (MHD) stability of oscillatory natural
convection flow in a rectangular cavity, with free top surface, filled
with a liquid metal, having an aspect ratio equal to A=L/H=5, and
subjected to a transversal temperature gradient and a uniform
magnetic field oriented in x and z directions. The finite volume
method was used in order to solve the equations of continuity,
momentum, energy, and potential. The stability diagram obtained in
this study highlights the dependence of the critical value of the
Grashof number Grcrit , with the increase of the Hartmann number
Ha for two orientations of the magnetic field. This study confirms
the possibility of stabilization of a liquid metal flow in natural
convection by application of a magnetic field and shows that the
flow stability is more important when the direction of magnetic field
is longitudinal than when the direction is transversal.
Abstract: This paper presents an overview of current municipal
solid waste management in Khoram Abad city.
According to data collected by the local authorities, the waste
generation rate is estimated to be 800 g/cap.d with density of 243
kg/m3. Solid waste is stored in different types of containers at the
source of generation in different areas of the city.
Local Authority is responsible for waste collection, transportation.
Municipality is responsible for waste collection, using private sector
contracts.
At present, both mechanical and manual methods are used to
collect residential waste. Manual methods of collection are the most
commonly used for waste collection in most parts of the city.
Land filling is the main disposal method in this city. But it has
some obvious problem and deficiencies
The current state of solid waste management has been improved
slightly in the last decade. By more actions can reduce the human and
environmental risks.
Abstract: This article presents a numerical study of the doublediffusive
mixed convection in a vertical channel filled with porous
medium by using non-equilibrium model. The flow is assumed
fully developed, uni-directional and steady state. The controlling
parameters are thermal Rayleigh number (RaT ), Darcy number (Da),
Forchheimer number (F), buoyancy ratio (N), inter phase heat transfer
coefficient (H), and porosity scaled thermal conductivity ratio
(γ). The Brinkman-extended non-Darcy model is considered. The
governing equations are solved by spectral collocation method. The
main emphasize is given on flow profiles as well as heat and solute
transfer rates, when two diffusive components in terms of buoyancy
ratio are in favor (against) of each other and solid matrix and fluid
are thermally non-equilibrium. The results show that, for aiding flow
(RaT = 1000), the heat transfer rate of fluid (Nuf ) increases upto a
certain value of H, beyond that decreases smoothly and converges
to a constant, whereas in case of opposing flow (RaT = -1000),
the result is same for N = 0 and 1. The variation of Nuf in (N,
Nuf )-plane shows sinusoidal pattern for RaT = -1000. For both cases
(aiding and opposing) the flow destabilize on increasing N by inviting
point of inflection or flow separation on the velocity profile. Overall,
the buoyancy force have significant impact on the non-Darcy mixed
convection under LTNE conditions.
Abstract: The increasing number of senior population gradually
causes to demand the use of information and communication
technology for their satisfactory lives. This paper presents the
development of an integrated TV based system which offers an
opportunity to provide value added services to a large number of
elderly citizens, and thus helps improve their quality of life. The
design philosophy underlying this paper is to fulfill both technological
and human aspects. The balance between these two dimensions has
been currently stressed as a crucial element for the design of usable
systems in real use, particularly to the elderly who have physical and
mental decline. As the first step to achieve it, we have identified
human and social factors that affect the elder-s quality of life by a
literature review, and based on them, build four fundamental services:
information, healthcare, learning and social network services.
Secondly, the system architecture, employed technologies and the
elderly-friendly system design considerations are presented. This
reflects technological and human perspectives in terms of the system
design. Finally, we describe some scenarios that illustrate the
potentiality of the proposed system to improve elderly people-s quality
of life.
Abstract: This work presents a low-cost and eco-friendly
building material named Agrostone panel. Africa-s urban population
is growing at an annual rate of 2.8% and 62% of its population will
live in urban areas by 2050. As a consequence, many of the least
urbanized and least developed African countries- will face serious
challenges in providing affordable housing to the urban dwellers.
Since the cost of building materials accounts for the largest
proportion of the overall construction cost, innovating low-cost
building material is vital. Agrostone panel is used in housing projects
in Ethiopia. It uses raw materials of agricultural/industrial wastes
and/or natural minerals as a filler, magnesium-based chemicals as a
binder and fiberglass as reinforcement. Agrostone panel reduces the
cost of wall construction by 50% compared with the conventional
building materials. The pros and cons of Agrostone panel as well as
the use of other waste materials as a raw material to make the panel
more sustainable, low-cost and better properties are discussed.
Abstract: An autonomous environmental monitoring system
(Smart Landfill) has been constructed for the quantitative
measurement of the components of landfill gas found at borehole
wells at the perimeter of landfill sites. The main components of
landfill gas are the greenhouse gases, methane and carbon dioxide
and have been monitored in the range 0-5 % volume. This monitoring
system has not only been tested in the laboratory but has been
deployed in multiple field trials and the data collected successfully
compared with on-site monitors. This success shows the potential of
this system for application in environments where reliable gas
monitoring is crucial.
Abstract: Among the chemicals used for ammunition production, TNT (Trinitrotoluene) play a significant role since World War I and II. Various types of military weapon utilize TNT in casting process. However, the TNT casting process for warhead is difficult to control the cooling rate of the liquid TNT. This problem occurs because the casting process lacks the equipment to detect the temperature during the casting procedure This study presents the temperature detected by infrared camera to illustrate the cooling rate and cooling zone of curing, and demonstrates the optimization of TNT condition to reduce the risk of air gap occurred in the warhead which can result in the destruction afterward. Premature initiation of explosive-filled projectiles in response to set-back forces during gunfiring cause by casting defects. Finally the study can help improving the process of the TNT casting. The operators can control the curing of TNT inside the case by rising up the heating rod at the proper time. Consequently this can reduce tremendous time of rework if the air gaps occur and increase strength to lower elastic modulus. Therefore, it can be clearly concluded that the use of Infrared Cameras in this process is another method to improve the casting procedure.
Abstract: Self-compacting concrete (SCC), a new kind of high
performance concrete (HPC) have been first developed in Japan in
1986. The development of SCC has made casting of dense
reinforcement and mass concrete convenient, has minimized noise.
Fresh self-compacting concrete (SCC) flows into formwork and
around obstructions under its own weight to fill it completely and
self-compact (without any need for vibration), without any
segregation and blocking. The elimination of the need for
compaction leads to better quality concrete and substantial
improvement of working conditions. SCC mixes generally have a
much higher content of fine fillers, including cement, and produce
excessively high compressive strength concrete, which restricts its
field of application to special concrete only. To use SCC mixes in
general concrete construction practice, requires low cost materials to
make inexpensive concrete.
Rice husk ash (RHA) has been used as a highly reactive
pozzolanic material to improve the microstructure of the interfacial
transition zone (ITZ) between the cement paste and the aggregate in
self compacting concrete. Mechanical experiments of RHA blended
Portland cement concretes revealed that in addition to the pozzolanic
reactivity of RHA (chemical aspect), the particle grading (physical
aspect) of cement and RHA mixtures also exerted significant
influences on the blending efficiency.
The scope of this research was to determine the usefulness of Rice
husk ash (RHA) in the development of economical self compacting
concrete (SCC). The cost of materials will be decreased by reducing
the cement content by using waste material like rice husk ash instead
of.
This paper presents a study on the development of Mechanical
properties up to 180 days of self compacting and ordinary concretes
with rice-husk ash (RHA), from a rice paddy milling industry in
Rasht (Iran). Two different replacement percentages of cement by
RHA, 10%, and 20%, and two different water/cementicious material
ratios (0.40 and 0.35), were used for both of self compacting and
normal concrete specimens. The results are compared with those of
the self compacting concrete without RHA, with compressive,
flexural strength and modulus of elasticity. It is concluded that RHA
provides a positive effect on the Mechanical properties at age after
60 days.
Base of the result self compacting concrete specimens have higher
value than normal concrete specimens in all test except modulus of
elasticity. Also specimens with 20% replacement of cement by RHA
have the best performance.
Abstract: Studies on residential satisfaction have been actively
discussed under family house setting. However, limited studies have
been conducted on student residential satisfaction. This study is an
attempt to fill the research gap. It focuses on the influence of socioeconomic
on students- satisfaction with the universities- student
housing facilities. The students who stayed at the on-campus student
housing were the respondents. This study employed two-stage cluster
sampling method in classifying the respondents. Self-administered
questionnaires were distributed face-to-face to the students. In
general, it is confirmed that students- socio-economic backgrounds
have influence on the students- satisfaction with their housing
facilities. The main influential factors were the students- economic
status, sense of sharing, and ethnicity of their roommates.
Furthermore, this study could also provide a useful feedback for the
universities in order to improve their student housing facilities.
Abstract: The fine structure of supercavitation in the wake of a
symmetrical cylinder is studied with high-speed video cameras. The
flow is observed in a cavitation tunnel at the speed of 8m/sec when the
sidewall and the wake are partially filled with the massive cavitation
bubbles. The present experiment observed that a two-dimensional
ripple wave with a wave length of 0.3mm is propagated in a
downstream direction, and then abruptly increases to a thicker
three-dimensional layer. IR-photography recorded that the wakes
originated from the horseshoe vortexes alongside the cylinder. The
wake was developed to inside the dead water zone, which absorbed the
bubbly wake propelled from the separated vortices at the center of the
cylinder. A remote sensing classification technique (maximum most
likelihood) determined that the surface porosity was 0.2, and the mean
speed in the mixed wake was 7m/sec. To confirm the existence of
two-dimensional wave motions in the interface, the experiments were
conducted at a very low frequency, and showed similar gravity waves
in both the upper and lower interfaces.
Abstract: An envelope echo signal measurement is proposed in
this paper using echo signal observation from the 200 kHz echo
sounder receiver. The envelope signal without any object is compared
with the envelope signal of the sphere. Two diameter size steel ball
(3.1 cm & 2.2 cm) and two diameter size air filled stainless steel ball
(4.8 cm & 7.4 cm) used in this experiment. The target was positioned
about 0.5 m and 1.0 meter from the transducer face using nylon rope.
From the echo observation in time domain, it is obviously shown that
echo signal structure is different between the size, distance and type
of metal sphere. The amplitude envelope voltage for the bigger
sphere is higher compare to the small sphere and it confirm that the
bigger sphere have higher target strength compare to the small
sphere. Although the structure signal without any object are different
compare to the signal from the sphere, the reflected signal from the
tank floor increase linearly with the sphere size. We considered this
event happened because of the object position approximately to the
tank floor.
Abstract: Sandwich panels are widely used in the construction
industry for their ease of assembly, light weight and efficient thermal
performance. They are composed of two RC thin outer layers
separated by an insulating inner layer. In this research the inner
insulating layer is made of lightweight Autoclaved Aerated Concrete
(AAC) blocks which has good thermal insulation properties and yet
possess reasonable mechanical strength. The shear strength of the
AAC infill is relied upon to replace the traditionally used insulating
foam and to provide the shear capacity of the panel. A
comprehensive experimental program was conducted on full scale
sandwich panels subjected to bending. In this paper, detailed
numerical modeling of the tested sandwich panels is reported. Nonlinear
3-D finite element modeling of the composite action of the
sandwich panel is developed using ANSYS. Solid elements with
different crashing and cracking capabilities and different constitutive
laws were selected for the concrete and the AAC. Contact interface
elements are used in this research to adequately model the shear
transfer at the interface between the different layers. The numerical
results showed good correlation with the experimental ones
indicating the adequacy of the model in estimating the loading
capacity of panels.
Abstract: Neighborhood Rough Sets (NRS) has been proven to
be an efficient tool for heterogeneous attribute reduction. However,
most of researches are focused on dealing with complete and noiseless
data. Factually, most of the information systems are noisy, namely,
filled with incomplete data and inconsistent data. In this paper, we
introduce a generalized neighborhood rough sets model, called
VPTNRS, to deal with the problem of heterogeneous attribute
reduction in noisy system. We generalize classical NRS model with
tolerance neighborhood relation and the probabilistic theory.
Furthermore, we use the neighborhood dependency to evaluate the
significance of a subset of heterogeneous attributes and construct a
forward greedy algorithm for attribute reduction based on it.
Experimental results show that the model is efficient to deal with noisy
data.
Abstract: Antimosy-doped tin oxide (ATO) particles were
prepared via chemical coprecipitation and reverse emulsion. The size
and size distribution of ATO particles were obviously decreased via
reverse microemulsion method. At the relatively high yield the ATO
particles were nearly spherical in shape, meanwhile the crystalline
structure and excellent conductivity were reserved, which could satisfy
the requirement as composite fillers, such as dielectric filler of
polyimide film.
Abstract: This article attempts to analyze functionally graded beam thermal buckling along with piezoelectric layers applying based on the third order shearing deformation theory considering various boundary conditions. The beam properties are assumed to vary continuously from the lower surface to the upper surface of the beam. The equilibrium equations are derived using the total potential energy equations, Euler equations, piezoelectric material constitutive equations and third order shear deformation theory assumptions. In order to fulfill such an aim, at first functionally graded beam with piezoelectric layers applying the third order shearing deformation theory along with clamped -clamped boundary conditions are thoroughly analyzed, and then following making sure of the correctness of all the equations, the very same beam is analyzed with piezoelectric layers through simply-simply and simply-clamped boundary conditions. In this article buckling critical temperature for functionally graded beam is derived in two different ways, without piezoelectric layer and with piezoelectric layer and the results are compared together. Finally, all the conclusions obtained will be compared and contrasted with the same samples in the same and distinguished conditions through tables and charts. It would be noteworthy that in this article, the software MAPLE has been applied in order to do the numeral calculations.