Abstract: This paper presents the electromagnetic interference
(EMI) shielding effectiveness of rice husk and carbon nanotubes
(RHCNTs) composites in the X-band region (8.2-12.4 GHz). The
difference weight ratio of carbon nanotubes (CNTs) were mix with
the rice husk. The rectangular waveguide technique was used to
measure the complex permittivity of the RHCNTs composites
materials. The complex permittivity is represented in terms of both
the real and imaginary parts of permittivity in X-band frequency. The
conductivity of RHCNTs shows increasing when the ratio of CNTs
mixture increases. The composites materials were simulated using
Computer Simulation Technology (CST) Microwave Studio
simulation software. The shielding effectiveness of RHCNTs and
pure rice husk was compared. The highest EMI SE of 30 dB is
obtained for RHCNTs composites of 10 wt % CNTs with 10mm
thickness.
Abstract: Advances technology in the field of photogrammetry
replaces analog cameras with reflection on aircraft GPS/IMU system
with a digital aerial camera. In this system, when determining the
position of the camera with the GPS, camera rotations are also
determined by the IMU systems. All around the world, digital aerial
cameras have been used for the photogrammetry applications in the
last ten years. In this way, in terms of the work done in
photogrammetry it is possible to use time effectively, costs to be
reduced to a minimum level, the opportunity to make fast and
accurate.
Geo-referencing techniques that are the cornerstone of the GPS /
INS systems, photogrammetric triangulation of images required for
balancing (interior and exterior orientation) brings flexibility to the
process. Also geo-referencing process; needed in the application of
photogrammetry targets to help to reduce the number of ground
control points. In this study, the use of direct and indirect georeferencing
techniques on the accuracy of the points was investigated
in the production of photogrammetric mapping.
Abstract: The objectives were to study language learning strategies (LLSs) employed by Chinese students, and the frequency of LLSs they used, and examine the relationship between the use of LLSs and gender. The Strategy Inventory for Language Learning (SILL) by Oxford was administered to thirty-six Chinese students at Suan Sunandha Rajabhat University in Thailand. The data obtained was analyzed using descriptive statistics and chi-square tests. Three useful findings were found on the use of LLSs reported by Chinese students. First, Chinese students used overall LLSs at a high level. Second, among the six strategy groups, Chinese students employed compensation strategy most frequently and memory strategy least frequently. Third, the research results also revealed that gender had significant effect on Chinese Student’s use of overall LLSs.
Abstract: Owing to the lack of synchronization between the solar energy availability and the heat demands in a specific application, the energy storing sub-system is necessary to maintain the continuity of thermal process. The present work is dealing with an active solar heating storing system in which an air solar collector is connected to storing unit where this energy is distributed and provided to the heated space in a controlled manner. The solar collector is a box type absorber where the air flows between a number of vanes attached between the collector absorber and the bottom plate. This design can improve the efficiency due to increasing the heat transfer area exposed to the flowing air, as well as the heat conduction through the metal vanes from the top absorbing surface. The storing unit is a packed bed type where the air is coming from the air collector and circulated through the bed in order to add/remove the energy through the charging / discharging processes, respectively. The major advantage of the packed bed storage is its high degree of thermal stratification. Numerical solution of the packed bed energy storage is considered through dividing the bed into a number of equal segments for the bed particles and solved the energy equation for each segment depending on the neighbor ones. The studied design and performance parameters in the developed simulation model including, particle size, void fraction, etc. The final results showed that the collector efficiency was fluctuated between 55%-61% in winter season (January) under the climatic conditions of Misurata in Libya. Maximum temperature of 52ºC is attained at the top of the bed while the lower one is 25ºC at the end of the charging process of hot air into the bed. This distribution can satisfy the required load for the most house heating in Libya.
Abstract: Gold nanoparticles (AuNPs) have gained increasing
interest in recent times. This is greatly due to their special features,
which include unusual optical and electronic properties, high stability
and biological compatibility, controllable morphology and size
dispersion, and easy surface functionalization. In typical synthesis,
AuNPs were produced by reduction of gold salt AuCl4 in an
appropriate solvent. A stabilizing agent was added to prevent the
particles from aggregating. The antibacterial activity of different
sizes of gold nanoparticles was investigated against Staphylococcus
aureus, Salmonella typhi and Pseudomonas pneumonia using the disk
diffusion method in a Müeller–Hinton Agar. The Au-NPs were
effective against all bacteria tested. That the Au-NPs were
successfully synthesized in suspension and were used to study the
antibacterial activity of the two medicinal plants against some
bacterial pathogens suggests that Au-NPs can be employed as an
effective bacteria inhibitor and may be an effective tool in medical
field. The study clearly showed that the Au-NPs exhibiting inhibition
towards the tested pathogenic bacteria in vitro could have the same
effects in vivo and thus may be useful in the medical field if well
researched into.
Abstract: In the present time, energy crises is considered a severe problem across the world. For the protection of global environment and maintain ecological balance, energy saving is considered one of the most vital issues from the view point of fuel consumption. As the industrial sectors everywhere continue efforts to improve their energy efficiency, recovering waste heat losses provides an attractive opportunity for an emission free and less costly energy resource. In the other hand the using of solar energy has become more insistent particularly after the high gross of prices and running off the conventional energy sources. Therefore, it is essential that we should endeavor for waste heat recovery as well as solar energy by making significant and concrete efforts. For these reasons this investigation is carried out to study and analyze the performance of a power plant working by a combined cycle in which heat recovery system generator (HRSG) gets its energy from the waste heat of a gas turbine unit. Evaluation of the performance of the plant is based on different thermal efficiencies of the main components in addition to the second law analysis considering the exergy destructions for the whole components. The contribution factors including the solar as well as the wasted energy are considered in the calculations. The final results have shown that there is significant exergy destruction in solar concentrator and the combustion chamber of the gas turbine unit. Other components such as compressor, gas turbine, steam turbine and heat exchangers having insignificant exergy destruction. Also, solar energy can contribute by about 27% of the input energy to the plant while the energy lost with exhaust gases can contribute by about 64% at maximum cases.
Abstract: Protein hydrolysates prepared from a number of medicinal plants are promising sources of various bioactive peptides. In this work, proteins from dried whole plant of Euphorbia hirta Linn. were extracted and digested with pepsin for 12h. The hydrolysates of lesser than 3 KDa were fractionated by a cut-off membrane. The peptide hydrolysate was then purified by an anion-exchange chromatography on DEAE-Sephacel™ column and reverse-phase chromatography on Sep-pak C18 column, respectively. The cytotoxic effect of each peptide fraction against a gastric carcinoma cell line (KATO-III, ATCC No. HTB103) was investigated using colorimetric MTT viability assay. A human liver cell line (Chang Liver, CLS No. 300139) was used as a control normal cell line. Two purified peptide peaks, peak l and peak ll at 100µg peptides mL-1 affected cell viability of the gastric cancer cell lines to 63.85±4.94 and 66.92±6.46%, respectively. Our result showed for the first time that the peptide fractions derived from protein hydrolysate of Euphorbia hirta Linn. have anti-gastric cancer activity, which offers a potential novel and natural anti-gastric cancer remedy.
Abstract: One of the main objectives of order reduction is to
design a controller of lower order which can effectively control the
original high order system so that the overall system is of lower
order and easy to understand. In this paper, a simple method is
presented for controller design of a higher order discrete system.
First the original higher order discrete system in reduced to a lower
order model. Then a Proportional Integral Derivative (PID)
controller is designed for lower order model. An error minimization
technique is employed for both order reduction and controller
design. For the error minimization purpose, Differential Evolution
(DE) optimization algorithm has been employed. DE method is
based on the minimization of the Integral Squared Error (ISE)
between the desired response and actual response pertaining to a
unit step input. Finally the designed PID controller is connected to
the original higher order discrete system to get the desired
specification. The validity of the proposed method is illustrated
through a numerical example.
Abstract: An approach for experimental measurement of the
dynamic characteristics of linear electromagnet actuators is
presented. It uses accelerometer sensor to register the armature
acceleration. The velocity and displacement of the moving parts can
be obtained by integration of the acceleration results. The armature
movement of permanent magnet linear actuator is acquired using this
technique. The results are analyzed and the performance of the
supposed approach is compared with the most commonly used
experimental setup where the displacement of the armature vs. time
is measured instead of its acceleration.
Abstract: An exact algorithm for a n-link manipulator movement amidst arbitrary unknown static obstacles is presented.
The algorithm guarantees the reaching of a target configuration of the manipulator in a finite number of steps. The algorithm is
reduced to a finite number of calls of a subroutine for planning a trajectory in the presence of known forbidden states. The polynomial approximation algorithm which is used as the subroutine is presented. The results of the exact algorithm
implementation for the control of a seven link (7 degrees of
freedom, 7DOF) manipulator are given.
Abstract: Surgical site infections (SSIs) are the most common
nosocomial infection in surgical patients resulting in significant
increases in postoperative morbidity and mortality. The commonly
causative bacteria developed resistance to virtually all antibiotics
available. The aim of this study was to isolation and identification the
most common bacteria that cause SSIs in Medical Research Institute,
and to compare their sensitivity to selected group of antibiotics and
natural products (garlic, oregano, olive, and Nigella sativa oils). The
isolated pathogens collected from infected surgical wounds were
identified, and their sensitivities to the antibiotics commonly
available for clinical use, and also to the different concentrations of
the used natural products were investigated. The results indicate to
the potential therapeutic effect of the tested natural products in
treatment of surgical wound infections.
Abstract: This work presents a study on the abrasive water jet
(AWJ) machining. An explicit finite element analysis (FEA) of
single abrasive particle impact on stainless steel 1.4304 (AISI 304) is
conducted. The abrasive water jet machining is modeled by FEA
software ABAQUS/CAE. Shapes of craters in FEM simulation
results were used and compared with the previous experimental and
FEM works by means of crater sphericity. The influence of impact
angle and particle velocity was observed. Adaptive mesh domain is
used to model the impact zone. Results are in good agreement with
those obtained from the experimental and FEM simulation. The
crater-s depth is also obtained for different impact angle and abrasive
particle velocities.
Abstract: This work presents the hydrogen production from
steam gasification of palm kernel shell (PKS) at 700 oC in the
presence of 5% Ni/BEA and 5% Fe/BEA as catalysts. The steam
gasification was performed in two-staged reactors to evaluate the
effect of calcinations temperature and the steam to biomass ratio on
the product gas composition. The catalytic activity of Ni/BEA
catalyst decreases with increasing calcinations temperatures from 500
to 700 oC. The highest H2 concentration is produced by Fe/BEA
(600) with more than 71 vol%. The catalytic activity of the catalysts
tested is found to correspond to its physicochemical properties. The
optimum range for steam to biomass ratio if found to be between 2 to
4. Excess steam content results in temperature drop in the gasifier
which is undesirable for the gasification reactions.
Abstract: Probability-based identity disclosure risk
measurement may give the same overall risk for different
anonymization strategy of the same dataset. Some entities in the
anonymous dataset may have higher identification risks than the
others. Individuals are more concerned about higher risks than the
average and are more interested to know if they have a possibility of
being under higher risk. A notation of overall risk in the above
measurement method doesn-t indicate whether some of the involved
entities have higher identity disclosure risk than the others. In this
paper, we have introduced an identity disclosure risk measurement
method that not only implies overall risk, but also indicates whether
some of the members have higher risk than the others. The proposed
method quantifies the overall risk based on the individual risk values,
the percentage of the records that have a risk value higher than the
average and how larger the higher risk values are compared to the
average. We have analyzed the disclosure risks for different
disclosure control techniques applied to original microdata and
present the results.
Abstract: Chemical vapor deposition method was used to
produce carbon nanotubes on an iron based catalyst from acetylene.
Gas-phase samples collected from the different positions of the tubular reactor were analyzed by GC/MS. A variety of species ranging from hydrogen to naphthalene were observed and changes in their concentrations were plotted against the reactor position. Briefly benzene, toluene, styrene, indene and naphthalene were the main
higher molecular weight species and vinylacetylene and diacetylene were the important intermediates. Nanotube characterization was performed by scanning electron microscopy and transmission electron microscopy.
Abstract: This paper aims to study decomposition behavior in
pyrolytic environment of four lignocellulosic biomass (oil palm shell,
oil palm frond, rice husk and paddy straw), and two commercial
components of biomass (pure cellulose and lignin), performed in a
thermogravimetry analyzer (TGA). The unit which consists of a
microbalance and a furnace flowed with 100 cc (STP) min-1 Nitrogen,
N2 as inert. Heating rate was set at 20⁰C min-1 and temperature
started from 50 to 900⁰C. Hydrogen gas production during the
pyrolysis was observed using Agilent Gas Chromatography Analyzer
7890A. Oil palm shell, oil palm frond, paddy straw and rice husk
were found to be reactive enough in a pyrolytic environment of up to
900°C since pyrolysis of these biomass starts at temperature as low as
200°C and maximum value of weight loss is achieved at about
500°C. Since there was not much different in the cellulose,
hemicelluloses and lignin fractions between oil palm shell, oil palm
frond, paddy straw and rice husk, the T-50 and R-50 values obtained
are almost similar. H2 productions started rapidly at this temperature
as well due to the decompositions of biomass inside the TGA.
Biomass with more lignin content such as oil palm shell was found to
have longer duration of H2 production compared to materials of high
cellulose and hemicelluloses contents.
Abstract: As the fossil fuels kept on depleting, intense research in developing hydrogen (H2) as the alternative fuel has been done to cater our tremendous demand for fuel. The potential of H2 as the ultimate clean fuel differs with the fossil fuel that releases significant amounts of carbon dioxide (CO2) into the surrounding and leads to the global warming. The experimental work was carried out to study the production of H2 from palm kernel shell steam gasification at different variables such as heating rate, steam to biomass ratio and adsorbent to biomass ratio. Maximum H2 composition which is 61% (volume basis) was obtained at heating rate of 100oCmin-1, steam/biomass of 2:1 ratio, and adsorbent/biomass of 1:1 ratio. The commercial adsorbent had been modified by utilizing the alcoholwater mixture. Characteristics of both adsorbents were investigated and it is concluded that flowability and floodability of modified CaO is significantly improved.
Abstract: A modified Saleh-Valenzuela channel model has been
adapted for Ultra Wideband (UWB) system. The suggested realistic
channel is assessed by its distribution of fading amplitude and time of
arrivals. Furthermore, the propagation characteristic has been distinct
into four channel models, namely CM 1 to 4. Each are differentiate in
terms of cluster arrival rates, rays arrival rate within each cluster and
its respective constant decay rates. This paper described the
multiband OFDM system performance simulates under these
multipath conditions. Simulation work described in this paper is
based on WiMedia ECMA-368 standard, which has been deployed
for practical implementation of low cost and low power UWB
devices.
Abstract: Solidarity and kinship has long been an intangible
emblem to Malay community especially in the rural area. It is visibly
seen through the dependability among each unit of the community
either in religious and social events including the matrimonial or
wedding. Nevertheless, the inevitable phenomenon, modernization
legitimately alters every facets of human life not only the routines,
traditions, rituals, norms but also to the daily activities and the
specific occasion. Using triangulation approach of interview and self
completed questionnaire this study empirically examine the level of
alteration of Malays wedding foodways which relate to the
preparation and consumption of it and its impact on the community
social bonding. Some meaningful insights were obtained whereby
modernization through technology (modern equipments) and social
factors (education, migration, and high disposal income) significantly
contribute to the alteration of wedding foodways from preparation up
to consumption stages. The domino effect of this alteration
consequently leads to the fragility of social kinship or somehow
reduced cohesiveness and interaction among the individual of Malay
society in the rural area.
Abstract: The aim of this paper is to present the kinematic
analysis and mechanism design of an assistive robotic leg for
hemiplegic and hemiparetic patients. In this work, the priority is to
design and develop the lightweight, effective and single driver
mechanism on the basis of experimental hip and knee angles- data for
walking speed of 1 km/h. A mechanism of cam-follower with three
links is suggested for this purpose. The kinematic analysis is carried
out and analysed using commercialized MATLAB software based on
the prototype-s links sizes and kinematic relationships. In order to
verify the kinematic analysis of the prototype, kinematic analysis data
are compared with the experimental data. A good agreement between
them proves that the anthropomorphic design of the lower extremity
exoskeleton follows the human walking gait.