Abstract: In this research work, poly (acrylonitrile-butadienestyrene)/
polypropylene (ABS/PP) blends were processed by melt
compounding in a twin-screw extruder. Upgrading of the thermal
characteristics of the obtained materials was attempted by the
incorporation of organically modified montmorillonite (OMMT), as
well as, by the addition of two types of compatibilizers;
polypropylene grafted with maleic anhydride (PP-g-MAH) and ABS
grafted with maleic anhydride (ABS-g-MAH). The effect of the
above treatments was investigated separately and in combination.
Increasing the PP content in ABS matrix seems to increase the
thermal stability of their blend and the glass transition temperature
(Tg) of SAN phase of ABS. From the other part, the addition of ABS
to PP promotes the formation of its β-phase, which is maximum at 30
wt% ABS concentration, and increases the crystallization temperature
(Tc) of PP. In addition, it increases the crystallization rate of PP.The
β-phase of PP in ABS/PP blends is reduced by the addition of
compatibilizers or/and organoclay reinforcement. The incorporation
of compatibilizers increases the thermal stability of PP and reduces
its melting (ΔΗm) and crystallization (ΔΗc) enthalpies. Furthermore it
decreases slightly the Tgs of PP and SAN phases of ABS/PP blends.
Regarding the storage modulus of the ABS/PP blends, it presents a
change in their behavior at about 10°C and return to their initial
behavior at ~110°C. The incorporation of OMMT to no compatibilized
and compatibilized ABS/PP blends enhances their storage modulus.
Abstract: The aim of this paper is to study in depth some methodological aspects of social interventation, focusing on desirable passage from social maternage method to peer advocacy method. For this purpose, we intend analyze social and organizative components, that affect operator's professional action and that are part of his psychological environment, besides the physical and social one. In fact, operator's interventation should not be limited to a pure supply of techniques, nor to take shape as improvised action, but “full of good purposes".
Abstract: Nonlinear propagation of ion-acoustic waves in a selfgravitating
dusty plasma consisting of warm positive ions,
isothermal two-temperature electrons and negatively charged dust
particles having charge fluctuations is studied using the reductive
perturbation method. It is shown that the nonlinear propagation of
ion-acoustic waves in such plasma can be described by an uncoupled
third order partial differential equation which is a modified form of
the usual Korteweg-deVries (KdV) equation. From this nonlinear
equation, a new type of solution for the ion-acoustic wave is
obtained. The effects of two-temperature electrons, gravity and dust
charge fluctuations on the ion-acoustic solitary waves are discussed
with possible applications.
Abstract: The effect of artificial pozzolan (waste brick) on the
physico-chemical properties of cement manufactured was
investigated. The waste brick is generated by the manufacture of
bricks. It was used in the proportions of 0%, 5%, 10%, 15% and 20%
by mass of cement to study its effect on the physico-chemical
properties of cement incorporating artificial pozzolan. The physicochemical
properties of cement at anhydrous state and the hydrated
state (chemical composition, specific weight, fineness, consistency of
the cement paste and setting times) were studied. The experimental
results obtained show that the quantity of pozzolanic admixture
(waste brick) of cement manufactured is the principal parameter who
influences on the variation of the physico-chemical properties of the
cement tested.
Abstract: In the recent years, functionally gradient materials (FGMs) have gained considerable attention in the high temperature environment applications. In this paper, free vibration of thin functionally graded cylindrical shell with hole composed of stainless steel and zirconia is studied. The mechanical properties vary smoothly and continuously from one surface to the other according to a volume fraction power-law distribution. The Influence of shell geometrical parameters, variations of volume fractions and boundary conditions on natural frequency is considered. The equations of motion are based on strains-displacement relations from Love-s shell theory and Rayleigh method. The results have been obtained for natural frequencies of cylindrical shell with holes for different shape, number and location in this paper.
Abstract: Using the finite element analyses, this paper discusses the effects of temperature-dependent material properties on the stress and temperature fields in a cracked metal plate under the electric current load. The practical and complicated results are obtained when the temperature-dependent material properties are adopted in the analysis. If the simplified (temperature-independent) material properties are used, incorrect results will be obtained.
Abstract: The advances in multimedia and networking technologies
have created opportunities for Internet pirates, who can easily
copy multimedia contents and illegally distribute them on the Internet,
thus violating the legal rights of content owners. This paper describes
how a simple and well-known watermarking procedure based on a
spread spectrum method and a watermark recovery by correlation can
be improved to effectively and adaptively protect MPEG-2 videos
distributed on the Internet. In fact, the procedure, in its simplest
form, is vulnerable to a variety of attacks. However, its security
and robustness have been increased, and its behavior has been
made adaptive with respect to the video terminals used to open
the videos and the network transactions carried out to deliver them
to buyers. In fact, such an adaptive behavior enables the proposed
procedure to efficiently embed watermarks, and this characteristic
makes the procedure well suited to be exploited in web contexts,
where watermarks usually generated from fingerprinting codes have
to be inserted into the distributed videos “on the fly", i.e. during the
purchase web transactions.
Abstract: Mobile learning (M-learning) is the current technology that is becoming more popular. It uses the current mobile and wireless computing technology to complement the effectiveness of traditional learning process. The objective of this paper is presents a survey from 90 undergraduate students of Universiti Teknologi PETRONAS (UTP), to identify the students- perception on Mlearning. From the results, the students are willing to use M-learning. The acceptance level of the students is high, and the results obtained revealed that the respondents almost accept M-learning as one method of teaching and learning process and also able to improve the educational efficiency by complementing traditional learning in UTP.
Abstract: The abundance and availability of rice husk, an agricultural waste, make them as a good source for precursor of activated carbon. In this work, rice husk-based activated carbons were prepared via base treated chemical activation process prior the carbonization process. The effect of carbonization temperatures (400, 600 and 800oC) on their pore structure was evaluated through morphology analysis using scanning electron microscope (SEM). Sample carbonized at 800oC showed better evolution and development of pores as compared to those carbonized at 400 and 600oC. The potential of rice husk-based activated carbon as an alternative adsorbent was investigated for the removal of Ni(II), Zn(II) and Pb(II) from single metal aqueous solution. The adsorption studies using rice husk-based activated carbon as an adsorbent were carried out as a function of contact time at room temperature and the metal ions were analyzed using atomic absorption spectrophotometer (AAS). The ability to remove metal ion from single metal aqueous solution was found to be improved with the increasing of carbonization temperature. Among the three metal ions tested, Pb(II) ion gave the highest adsorption on rice husk-based activated carbon. The results obtained indicate the potential to utilize rice husk as a promising precursor for the preparation of activated carbon for removal of heavy metals.
Abstract: Indigenous Knowledge (IK) has many social and
economic benefits. However, IK is at the risk of extinction due to the
difficulties to preserve it as most of the IK largely remains
undocumented. This study aims to design a model of the factors
affecting the adoption of Information and Communication
Technologies (ICTs) for the preservation of IK. The proposed model
is based on theoretical frameworks on ICT adoption. It was designed
following a literature review of ICT adoption theories for households,
and of the factors affecting ICT adoption for IK. The theory that
fitted to the best all factors was then chosen as the basis for the
proposed model. This study found that the Model of Adoption of
Technology in Households (MATH) is the most suitable theoretical
framework for modeling ICT adoption factors for the preservation of
IK.
Abstract: In this paper the Differential Quadrature Method (DQM) is employed to study the coupled lateral-torsional free vibration behavior of the laminated composite beams. In such structures due to the fiber orientations in various layers, the lateral displacement leads to a twisting moment. The coupling of lateral and torsional vibrations is modeled by the bending-twisting material coupling rigidity. In the present study, in addition to the material coupling, the effects of shear deformation and rotary inertia are taken into account in the definition of the potential and kinetic energies of the beam. The governing differential equations of motion which form a system of three coupled PDEs are solved numerically using DQ procedure under different boundary conditions consist of the combinations of simply, clamped, free and other end conditions. The resulting natural frequencies and mode shapes for cantilever beam are compared with similar results in the literature and good agreement is achieved.
Abstract: In this paper, we present a method named Signal Level
Matrix (SLM) which can improve the accuracy and stability of active
RFID indoor positioning system. Considering the accuracy and cost,
we use uniform distribution mode to set up and separate the
overlapped signal covering areas, in order to achieve preliminary
location setting. Then, based on the proposed SLM concept and the
characteristic of the signal strength value that attenuates as the
distance increases, this system cross-examines the distribution of
adjacent signals to locate the users more accurately. The experimental
results indicate that the adaptive positioning method proposed in this
paper could improve the accuracy and stability of the positioning
system effectively and satisfyingly.
Abstract: The vibrations produced by a single point defect on
various parts of the bearing under constant radial load are predicted
by using a theoretical model. The model includes variation in the
response due to the effect of bearing dimensions, rotating frequency
distribution of load. The excitation forces are generated when the
defects on the races strike to rolling elements. In case of the outer
ring defect, the pulses generated are with periodicity of outer ring
defect frequency where as for inner ring defect, the pulses are with
periodicity of inner ring defect frequency. The effort has been carried
out in preparing the physical model of the system. Different defect
frequencies are obtained and are used to find out the amplitudes of
the vibration due to excitation of the bearing parts. Increase in the
radial load or severity of the defect produces a significant change in
bearing signature characteristics.
Abstract: 16-Mercaptohexadecanoic acid (MHDA) and tripeptide glutathione conjugated with gold nanoparticles (Au-NPs) are characterized by Fourier Transform InfaRared (FTIR) spectroscopy combined with Surface-enhanced Raman scattering (SERS) spectroscopy. Surface Plasmon Resonance (SPR) technique based on FTIR spectroscopy has become an important tool in biophysics, which is perspective for the study of organic compounds. FTIR-spectra of MHDA shows the line at 2500 cm-1 attributed to thiol group which is modified by presence of Au-NPs, suggesting the formation of bond between thiol group and gold. We also can observe the peaks originate from characteristic chemical group. A Raman spectrum of the same sample is also promising. Our preliminary experiments confirm that SERS-effect takes place for MHDA connected with Au-NPs and enable us to detected small number (less than 106 cm-2) of MHDA molecules. Combination of spectroscopy methods: FTIR and SERS – enable to study optical properties of Au- NPs and immobilized bio-molecules in context of a bio-nano-sensors.
Abstract: The recent growth of using multimedia transmission
over wireless communication systems, have challenges to protect the
data from lost due to wireless channel effect. Images are corrupted
due to the noise and fading when transmitted over wireless channel,
in wireless channel the image is transmitted block by block, Due to
severe fading, entire image blocks can be damaged. The aim of this
paper comes out from need to enhance the digital images at the
wireless receiver side. Proposed Boundary Interpolation (BI)
Algorithm using wavelet, have been adapted here used to
reconstruction the lost block in the image at the receiver depend on
the correlation between the lost block and its neighbors. New
Proposed technique by using Boundary Interpolation (BI) Algorithm
using wavelet with Pixel interleaver has been implemented. Pixel
interleaver work on distribute the pixel to new pixel position of
original image before transmitting the image. The block lost through
wireless channel is only effects individual pixel. The lost pixels at the
receiver side can be recovered by using Boundary Interpolation (BI)
Algorithm using wavelet. The results showed that the New proposed
algorithm boundary interpolation (BI) using wavelet with pixel
interleaver is better in term of MSE and PSNR.
Abstract: The objectives of this study are to determine the
effects of soil cover type on characteristics of leachates generated
from landfill lysimeters. Four lysimeters with diameter and height
of 0.15 and 3.00 m, respectively, were prepared. Three lysimeters
were filled with municipal waste and three different cover soil types
i.e. sandy loam soil, silty loam soil and clay soil while another
lysimeter was filled solely with municipal waste. The study was
conducted in the rainy season. Leachate quantities were measured
every day and leachate characteristics were determined once a week.
The cumulative leachate quantity from the lysimeter filled solely
with municipal waste was found to be around 27% higher than the
lysimeters using cover soils. There were no any differences of the
cumulative leachate amounts generated from the lysimeters using
three types of soils. The comparison of the total mass of pollutants
generated from all lysimeters showed that the lysimeter filled solely
with municipal waste generated the maximum quantities of
pollutants. Among the lysimeters using different types of soils, the
lysimeter using sandy loam soil generated the lowest amount of most
of pollutants, compared with the lysimeters using silty loam and clay
soils. It can be concluded that in term of pollutant attenuation in the
leachate, a sandy loam is the most suitable soil to be used as a cover
soil in the landfill.
Abstract: This contribution deals with the relationship between
communication effectiveness and the extent of communication
among organizational units. To facilitate communication between
employees and to increase the level of understanding, the knowledge
of communication tools is necessary. Recent experience has shown
that personal communication is critical for smooth running of
companies and cannot be fully replaced by any form of technical
communication devices.
Below are presented the outcomes of the research on the
relationship between the extent of communication among
organisational units and its efficiency.
Abstract: A Variable Structure Model Reference Adaptive Controller using state variables is proposed for a class of multi input-multi output systems. Adaptation law is of variable structure type and switching functions is designed based on stability requirements. Global exponential stability is proved based on Lyapunov criterion. Transient behavior is analyzed using sliding mode control and shows perfect model following at a finite time.
Abstract: This study aims to investigate mechanical behavior of
deep-drawn cups consisting of aluminum (A1050)/ duralumin
(A2017) multi-layered clad structures with micro- and macro-scale
functional gradients. Such multi-layered clad structures are possibly
used for a new type of crash-boxes in automobiles to effectively
absorb the impact forces generated when automobiles having
collisions. The effect of heat treatments on microstructure,
compositional gradient, micro hardness in 2 and 6-layered aluminum/
duralumin clad structures, which were fabricated by hot rolling, have
been investigated. Impact compressive behavior of deep-drawn cups
consisting of such aluminum/ duralumin clad structures has been also
investigated in terms of energy absorption and maximum force.
Deep-drawn cups consisting of 6-layerd clad structures with microand
macro-scale functional gradients exhibit superior properties in
impact compressive tests.
Abstract: Recent evidences on liquidity and valuation of securities in the capital markets clearly show the importance of stock market liquidity and valuation of firms. In this paper, relationship between transparency, liquidity, and valuation is studied by using data obtained from 70 companies listed in Tehran Stock Exchange during2003-2012. In this study, discriminatory earnings management, as a sign of lack of transparency and Tobin's Q, was used as the criteria of valuation. The results indicate that there is a significant and reversed relationship between earnings management and liquidity. On the other hand, there is a relationship between liquidity and transparency.The results also indicate a significant relationship between transparency and valuation. Transparency has an indirect effect on firm valuation alone or through the liquidity channel. Although the effect of transparency on the value of a firm was reduced by adding the variable of liquidity, the cumulative effect of transparency and liquidity increased.