Abstract: This paper deals with nonlinear vibration analysis
using finite element method for frame structures consisting of elastic
and viscoelastic damping layers supported by multiple nonlinear
concentrated springs with hysteresis damping. The frame is supported
by four nonlinear concentrated springs near the four corners. The
restoring forces of the springs have cubic non-linearity and linear
component of the nonlinear springs has complex quantity to represent
linear hysteresis damping. The damping layer of the frame structures
has complex modulus of elasticity. Further, the discretized equations in
physical coordinate are transformed into the nonlinear ordinary
coupled differential equations using normal coordinate corresponding
to linear natural modes. Comparing shares of strain energy of the
elastic frame, the damping layer and the springs, we evaluate the
influences of the damping couplings on the linear and nonlinear impact
responses. We also investigate influences of damping changed by
stiffness of the elastic frame on the nonlinear coupling in the damped
impact responses.
Abstract: Work presented is interested in the characterization of
the quasistatic mechanical properties and in fatigue of a composite
laminated in jute/epoxy. The natural fibers offer promising prospects
thanks to their interesting specific properties, because of their low
density, but also with their bio-deterioration. Several scientific
studies highlighted the good mechanical resistance of the vegetable
fiber composites reinforced, even after several recycling. Because of
the environmental standards that become increasingly severe, one
attends the emergence of eco-materials at the base of natural fibers
such as flax, bamboo, hemp, sisal, jute. The fatigue tests on
elementary vegetable fibers show an increase of about 60% of the
rigidity of elementary fibers of hemp subjected to cyclic loadings. In
this study, the test-tubes manufactured by the method infusion have
sequences of stacking of 0/90° and ± 45° for the shearing and tensile
tests. The quasistatic tests reveal a variability of the mechanical
properties of about 8%. The tensile fatigue tests were carried out for
levels of constraints equivalent to half of the ultimate values of the
composite. Once the fatigue tests carried out for well-defined values
of cycles, a series of static tests of traction type highlights the
influence of the number of cycles on the quasi-static mechanical
behavior of the laminate jute/epoxy.
Abstract: A large amount of software products offer a wide
range and number of features. This is called featuritis or creeping
featurism and tends to rise with each release of the product. Feautiris
often adds unnecessary complexity to software, leading to longer
learning curves and overall confusing the users and degrading their
experience. We take a look to a new design approach tendency that
has been coming up, the so-called “What You Get is What You
Need” concept that argues that products should be very focused,
simple and with minimalistic interfaces in order to help users conduct
their tasks in distraction-free ambiences. This isn’t as simple to
implement as it might sound and the developers need to cut down
features. Our contribution illustrates and evaluates this design method
through a novel distraction-free diagramming tool named Delineato
Pro for Mac OS X in which the user is confronted with an empty
canvas when launching the software and where tools only show up
when really needed.
Abstract: A solar dish collector has been designed, fabricated
and tested for its performance on 10-03-2015 in Salem, Tamilnadu,
India. The experiments on cooking vessels of coated and un-coated
with 5 Liters capacity have been used for cooking Rice. The results
are shown in graphs. The solar cooker is always capable of cooking
food within the expected length of time and based on the solar
radiation levels. With minimum cooking power, the coated pressure
cooker of 5 Liters capacity cooks the food at faster manner. This is
due to the conductivity of the coating material provided in the cooker.
Abstract: The use of Flexible AC Transmission System
(FACTS) devices in a power system can potentially overcome
limitations of the present mechanically controlled transmission
system. Also, the advance of technology makes possible to include
new energy storage devices in the electrical power system. The
integration of Superconducting Magnetic Energy Storage (SMES)
into Static Synchronous Compensator (STATCOM) can lead to
increase their flexibility in improvement of power system dynamic
behaviour by exchanging both active and reactive powers with power
grids. This paper describes structure and behaviour of SMES,
specifications and performance principles of the STATCOM/SMES
compensator. Moreover, the benefits and effectiveness of integrated
SMES with STATCOM in power systems is presented. Also, the
performance of the STATCOM/SMES compensator is evaluated
using an IEEE 3-bus system through the dynamic simulation by
PSCAD/EMTDC software.
Abstract: High frequency automotive interior noise above 500
Hz considerably affects automotive passenger comfort. To reduce this
noise, sound insulation material is often laminated on body panels or
interior trim panels. For a more effective noise reduction, the sound
reduction properties of this laminated structure need to be estimated.
We have developed a new calculate tool that can roughly calculate the
sound absorption and insulation properties of laminate structure and
handy for designers. In this report, the outline of this tool and an
analysis example applied to floor mat are introduced.
Abstract: This research paper presents guiding on how to design
social media into higher education courses. The research
methodology used a survey approach. The research instrument was a
questionnaire about guiding on how to design social media into
higher education courses. Thirty-one lecturers completed the
questionnaire. The data were scored by frequency and percentage.
The research results were the lecturers’ opinions concerning the
designing social media into higher education courses as follows: 1)
Lecturers deem that the most suitable learning theory is Collaborative
Learning. 2) Lecturers consider that the most important learning and
innovation Skill in the 21st century is communication and
collaboration skills. 3) Lecturers think that the most suitable
evaluation technique is authentic assessment. 4) Lecturers consider
that the most appropriate portion used as blended learning should be
70% in the classroom setting and 30% online.
Abstract: This paper discusses the propagation of sound waves in
air, specifically in narrow rectangular pathways of an occluded-ear
simulator for acoustic measurements. In narrow pathways, both the
speed of sound and the phase of the sound waves are affected by the
damping of the air viscosity. Herein, we propose a new finite-element
method (FEM) that considers the effects of the air viscosity. The
method was developed as an extension of existing FEMs for porous,
sound-absorbing materials. The results of a numerical calculation for a
three-dimensional ear-simulator model using the proposed FEM were
validated by comparing with theoretical lumped-parameter modeling
analysis and standard values.
Abstract: In this paper, we report the development of the device
for diagnostics of cardiovascular system state and associated
automated workstation for large-scale medical measurement data
collection and analysis. It was shown that optimal design for the
monitoring device is wristband as it represents engineering trade-off
between accuracy and usability. Monitoring device is based on the
infrared reflective photoplethysmographic sensor, which allows
collecting multiple physiological parameters, such as heart rate and
pulsing wave characteristics. Developed device uses BLE interface
for medical and supplementary data transmission to the coupled
mobile phone, which processes it and send it to the doctor's
automated workstation. Results of this experimental model
approbation confirmed the applicability of the proposed approach.
Abstract: In order to obtain efficient pollutants removal in
small-scale wastewater treatment plants, uniform water flow has to be
achieved. The experimental setup, designed for treating high-load
wastewater (leachate), consists of two aerobic biological reactors and
a lamellar settler. Both biological tanks were aerated by using three
different types of aeration systems - perforated pipes, membrane air
diffusers and tube ceramic diffusers. The possibility of homogenizing
the water mass with each of the air diffusion systems was evaluated
comparatively. The oxygen concentration was determined by optical
sensors with data logging. The experimental data was analyzed
comparatively for all three different air dispersion systems aiming to
identify the oxygen concentration variation during different
operational conditions. The Oxygenation Capacity was calculated for
each of the three systems and used as performance and selection
parameter. The global mass transfer coefficients were also evaluated
as important tools in designing the aeration system. Even though
using the tubular porous diffusers leads to higher oxygen
concentration compared to the perforated pipe system (which
provides medium-sized bubbles in the aqueous solution), it doesn’t
achieve the threshold limit of 80% oxygen saturation in less than 30
minutes. The study has shown that the optimal solution for the
studied configuration was the radial air diffusers which ensure an
oxygen saturation of 80% in 20 minutes. An increment of the values
was identified when the air flow was increased.
Abstract: In this article, we deal with a variant of the classical
course timetabling problem that has a practical application in many
areas of education. In particular, in this paper we are interested in
high schools remedial courses. The purpose of such courses is to
provide under-prepared students with the skills necessary to succeed
in their studies. In particular, a student might be under prepared in
an entire course, or only in a part of it. The limited availability
of funds, as well as the limited amount of time and teachers at
disposal, often requires schools to choose which courses and/or which
teaching units to activate. Thus, schools need to model the training
offer and the related timetabling, with the goal of ensuring the
highest possible teaching quality, by meeting the above-mentioned
financial, time and resources constraints. Moreover, there are some
prerequisites between the teaching units that must be satisfied. We
first present a Mixed-Integer Programming (MIP) model to solve
this problem to optimality. However, the presence of many peculiar
constraints contributes inevitably in increasing the complexity of
the mathematical model. Thus, solving it through a general-purpose
solver may be performed for small instances only, while solving
real-life-sized instances of such model requires specific techniques
or heuristic approaches. For this purpose, we also propose a heuristic
approach, in which we make use of a fast constructive procedure
to obtain a feasible solution. To assess our exact and heuristic
approaches we perform extensive computational results on both
real-life instances (obtained from a high school in Lecce, Italy) and
randomly generated instances. Our tests show that the MIP model is
never solved to optimality, with an average optimality gap of 57%.
On the other hand, the heuristic algorithm is much faster (in about the
50% of the considered instances it converges in approximately half of
the time limit) and in many cases allows achieving an improvement
on the objective function value obtained by the MIP model. Such an
improvement ranges between 18% and 66%.
Abstract: Low Temperature Matrix Isolation - Electron
Paramagnetic Resonance (LTMI-EPR) Spectroscopy was utilized to
identify the species of iron oxide nanoparticles generated during the
oxidative pyrolysis of 1-methylnaphthalene (1-MN). The otherwise
gas-phase reactions of 1--MN were impacted by a polypropylenimine
tetra-hexacontaamine dendrimer complexed with iron (III) nitrate
nonahydrate diluted in air under atmospheric conditions. The EPR
fine structure of Fe (III)2O3 nanoparticles clusters, characterized by gfactors
of 2.00, 2.28, 3.76 and 4.37 were detected on a cold finger
maintained at 77 K after accumulation over a multitude of
experiments. Additionally, a high valence Fe (IV) paramagnetic
intermediate and superoxide anion-radicals, O2•- adsorbed on
nanoparticle surfaces in the form of Fe (IV) --- O2•- were detected
from the quenching area of Zone 1 in the gas-phase.
Abstract: The present study applies the inverse method and
three-dimensional CFD commercial software in conjunction with the
experimental temperature data to investigate the heat transfer and fluid
flow characteristics of the plate-fin heat sink in a rectangular closed
enclosure. The inverse method with the finite difference method and
the experimental temperature data is applied to determine the
approximate heat transfer coefficient. Later, based on the obtained
results, the zero-equation turbulence model is used to obtain the heat
transfer and fluid flow characteristics between two fins. T0 validate
the accuracy of the results obtained, the comparison of the heat transfer
coefficient is made. The obtained temperature at selected
measurement locations of the fin is also compared with experimental
data. The effect of the height of the rectangular enclosure on the
obtained results is discussed.
Abstract: Determination of genetic variation is useful for plant
breeding and hence production of more efficient plant species under
different conditions, like drought stress. In this study a sample of 28
recombinant inbred lines (RILs) of wheat developed from the cross of
Norstar and Zagross varieties, together with their parents, were
evaluated for two years (2010-2012) under normal and water stress
conditions using split plot design with three replications. Main plots
included two irrigation treatments of 70 and 140 mm evaporation
from Class A pan and sub-plots consisted of 30 genotypes. The effect
of genotypes and interaction of genotypes with years and water
regimes were significant for all characters. Significant genotypic
effect implies the existence of genetic variation among the lines
under study. Heritability estimates were high for 1000 grain weight
(0.87). Biomass and grain yield showed the lowest heritability values
(0.42 and 0.50, respectively). Highest genotypic and phenotypic
coefficients of variation (GCV and PCV) belonged to harvest index.
Moderate genetic advance for most of the traits suggested the
feasibility of selection among the RILs under investigation. Some
RILs were higher yielding than either parent at both environments.
Abstract: In this research, a questionnaire survey was conducted
to measure nap, drowsiness and fatigue of drivers who work for long
shifts, to discuss about the work environment and health conditions for
taxi and bus drivers who work at night-time. The questionnaire sheet
used for this research was organized into the following categories:
tension/tiredness, drowsiness while driving, and the nap situation
during night-time work. The number of taxi drivers was 127 and the
number of bus drivers was 40. Concerning the results of a comparison
of nap hours of taxi and bus drivers, the taxi drivers’ nap hours are
overwhelmingly shorter, and also the frequency of drivers who
experience drowsiness is higher. The burden on bus drivers does not
change because of the system of a two-driver rotation shift. In
particular, the working environment of the taxi driver may lead to
greater fatigue accumulation than the bus driver’s environment.
Abstract: New environmental regulations and the increasing
market preference for companies that respect the ecosystem had
encouraged the industry to look after new treatments for its effluents.
The sugar industry, one of the largest emitter of environmental
pollutants, follows this tendency. Membrane technology is
convenient for separation of suspended solids, colloids and high
molecular weight materials that are present in a wastewater from
sugar industry. The idea is to microfilter the wastewater, where the
permeate passes through the membrane and becomes available for
recycle and re-use in the sugar manufacturing process. For
microfiltration of this effluent a tubular ceramic membrane was used
with a pore size of 200 nm at transmembrane pressure in range of 1–3
bars and in range of flow rate of 50–150 l/h. Kenics static mixer was
used for permeate flux enhancement. Turbidity and suspended solids
were removed and the permeate flux was continuously monitored
during the microfiltration process. The flux achieved after 90 minutes
of microfiltration was in a range of 50–70 l/m2h. The obtained
turbidity decrease was in the range of 50-99 % and total amount of
suspended solids was removed.
Abstract: The possibility of application the dietary fibers in
production of crackers was observed in this work, as well as their
influence on rheological and textural properties on the dough for
crackers and influence on sensory properties of obtained crackers.
Three different dietary fibers, oat, potato and pea fibers, replaced
10% of wheat flour. Long fermentation process and baking test
method were used for crackers production. The changes of dough for
crackers were observed by rheological methods of determination the
viscoelastic dough properties and by textural measurements. Sensory
quality of obtained crackers was described using quantity descriptive
method (QDA) by trained members of descriptive panel. Additional
analysis of crackers surface was performed by videometer. Based on
rheological determination, viscoelastic properties of dough for
crackers were reduced by application of dietary fibers. Manipulation
of dough with 10% of potato fiber was disabled, thus the recipe
modification included increase in water content at 35%. Dough
compliance to constant stress for samples with dietary fibers
decreased, due to more rigid and stiffer dough consistency compared
to control sample. Also, hardness of dough for these samples
increased and dough extensibility decreased. Sensory properties of
final products, crackers, were reduced compared to control sample.
Application of dietary fibers affected mostly hardness, structure and
crispness of the crackers. Observed crackers were low marked for
flavor and taste, due to influence of fibers specific aroma. The sample
with 10% of potato fibers and increased water content was the most
adaptable to applied stresses and to production process. Also this
sample was close to control sample without dietary fibers by
evaluation of sensory properties and by results of videometer method.
Abstract: In this paper, a new SMC (Sliding Mode Control)
method with MP (Model Predictive Control) integral action for the
slip suppression of EV (Electric Vehicle) under braking is proposed.
The proposed method introduce the integral term with standard SMC
gain , where the integral gain is optimized for each control period by
the MPC algorithms. The aim of this method is to improve the safety
and the stability of EVs under braking by controlling the wheel slip
ratio. There also include numerical simulation results to demonstrate
the effectiveness of the method.
Abstract: This research presents the main ideas to implement an
intelligent system composed by communicating wireless sensors
measuring environmental data linked to drought indicators (such as
air temperature, soil moisture , etc...). On the other hand, the setting
up of a spatio temporal database communicating with a Web mapping
application for a monitoring in real time in activity 24:00 /day, 7
days/week is proposed to allow the screening of the drought
parameters time evolution and their extraction. Thus this system
helps detecting surfaces touched by the phenomenon of drought.
Spatio-temporal conceptual models seek to answer the users who
need to manage soil water content for irrigating or fertilizing or other
activities pursuing crop yield augmentation. Effectively, spatiotemporal
conceptual models enable users to obtain a diagram of
readable and easy data to apprehend. Based on socio-economic
information, it helps identifying people impacted by the phenomena
with the corresponding severity especially that this information is
accessible by farmers and stakeholders themselves. The study will be
applied in Siliana watershed Northern Tunisia.
Abstract: In addition to the advantages of light weight, resistant
corrosion and ease of processing, aluminum is also applied to the
long-span spatial structures. However, the elastic modulus of
aluminum is lower than that of the steel. This paper combines the
high performance aluminum honeycomb panel with the aluminum
latticed shell, forming a new panel-and-rod composite shell structure.
Through comparative analysis between the static and dynamic
performance, the conclusion that the structure of composite shell is
noticeably superior to the structure combined before.