Abstract: High precision in motion is required to manipulate the
micro objects in precision industries for micro assembly, cell
manipulation etc. Precision manipulation is achieved based on the
appropriate mechanism design of micro devices such as
microgrippers. Design of a compliant based mechanism is the better
option to achieve a highly precised and controlled motion. This
research article highlights the method of designing a compliant based
three fingered microgripper suitable for holding asymmetric objects.
Topological optimization technique, a systematic method is
implemented in this research work to arrive a topologically optimized
design of the mechanism needed to perform the required micro
motion of the gripper. Optimization technique has a drawback of
generating senseless regions such as node to node connectivity and
staircase effect at the boundaries. Hence, it is required to have post
processing of the design to make it manufacturable. To reduce the
effect of post processing stage and to preserve the edges of the image,
a cubic spline interpolation technique is introduced in the MATLAB
program. Structural performance of the topologically developed
mechanism design is tested using finite element method (FEM)
software. Further the microgripper structure is examined to find its
fatigue life and vibration characteristics.
Abstract: Development of motor car safety devices has reduced
fatality rates in car accidents. Yet despite this increase in car safety,
neck injuries resulting from rear impact collisions, particularly at low
speed, remain a primary concern. In this study, FEA(Finite Element
Analysis) of seat was performed to evaluate neck injuries in rear
impact. And the FEA result was verified by comparison with the actual
test results. The dummy used in FE model and actual test is BioRID II
which is regarded suitable for rear impact collision analysis. A
threshold of the BioRID II neck injury indicators was also proposed to
upgrade seat performance in order to reduce whiplash injury. To
optimize the seat for a low-speed rear impact collision, a method was
proposed, which is multi-objective optimization idea using DOE
(Design of Experiments) results.
Abstract: RF performance of SOI CMOS device has attracted
significant amount of interest recently. In order to improve RF
parameters, Strained Si/Relaxed Si0.8Ge0.2 investigated as a
replacement for Si technology .Enhancement of carrier mobility
associated with strain engineering makes Strained Si a promising
candidate for improving RF performance of CMOS technology.
From the simulation, the cut-off frequency is estimated to be 224
GHZ, whereas in SOI at similar bias is about 188 GHZ. Therefore,
Strained Si exhibits 19% improvement in cut-off frequency over
similar Si counterpart. In this paper, Ion/Ioff ratio is studied as one of
the key parameters in logic and digital application. Strained Si/SiGe
demonstrates better Ion/Ioff characteristic than SOI, in similar channel
length of 100 nm.Another important key analog figures of merit such
as Early Voltage (VEA) ,transconductance vs drain current (gm /Ids)
are studied. They introduce the efficiency of the devices to convert
dc power into ac frequency.
Abstract: Single-pole switching scheme is widely used in the
Extra High Voltage system. However, the substantial negativesequence
current injected to the turbine-generators imposes the
electromagnetic (E/M) torque of double system- frequency
components during the dead time (between single-pole clearing and
line reclosing). This would induce supersynchronous resonance
(SPSR) torque amplifications on low pressure turbine generator
blades and even lead to fatigue damage. This paper proposes the
design of a mechanical filter (MF) with natural frequency close to
double-system frequency. From the simulation results, it is found that
such a filter not only successfully damps the resonant effect, but also
has the characteristics of feasibility and compact.
Abstract: The effect of extraction solvent upon properties
of carrageenan from Eucheuma cottonii was studied. The
distilled water and KOH solution (concentration 0.1- 0.5N) were
used as the solvent. Extraction process was carried out in water
bath equipped by stirrer with constant speed of 275 rpm with a
constant ratio of seaweed weight to solvent volume ( 1:50 g/mL)
at 86oC for 45 minutes. The extract was then precipitated in 3
volume of 90% ethanol, oven dried at 60oC. Based on
experimental data, alkali significantly influenced yield and
properties of extracted carrageenan. The extracted carrageenan
was found to have essentially identical FTIR spectra to the
reference samples of kappa-carrageenan. Increasing the KOH
concentration led to carrageenan containing less sulfate content
and intrinsic viscosity. The gel strength increased along with the
increasing of KOH concentration. The decreasing of intrinsic
viscosity value indicates that a polymer degradation occurs
during alkali extraction.
Abstract: The aim of this study was to compare the solubility of selected volatile organic compounds in water and silicon oil using the simple static headspace method. The experimental design allowed equilibrium achievement within 30 – 60 minutes. Infinite dilution activity coefficients and Henry-s law constants for various organics representing esters, ketones, alkanes, aromatics, cycloalkanes and amines were measured at 303K. The measurements were reproducible with a relative standard deviation and coefficient of variation of 1.3x10-3 and 1.3 respectively. The static determined activity coefficients using shaker flasks were reasonably comparable to those obtained using the gas liquid - chromatographic technique and those predicted using the group contribution methods mainly the UNIFAC. Silicon oil chemically known as polydimethysiloxane was found to be better absorbent for VOCs than water which quickly becomes saturated. For example the infinite dilution mole fraction based activity coefficients of hexane is 0.503 and 277 000 in silicon oil and water respectively. Thus silicon oil gives a superior factor of 550 696. Henry-s law constants and activity coefficients at infinite dilution play a significant role in the design of scrubbers for abatement of volatile organic compounds from contaminated air streams. This paper presents the phase equilibrium of volatile organic compounds in very dilute aqueous and polymeric solutions indicating the movement and fate of chemical in air and solvent. The successful comparison of the results obtained here and those obtained using other methods by the same authors and in literature, means that the results obtained here are reliable.
Abstract: Solid state fermentation of cassava peel with emphasis on protein enrichment using Trichoderma viride was evaluated. The effect of five variables: moisture content, pH, particle size (p), nitrogen source and incubation temperature; on the true protein and total sugars of cassava peel was investigated. The optimum fermentation period was established to be 8 days. Total sugars were 5-fold higher at pH 6 relative to pH 4 and 7-fold higher when cassava peels were fermented at 30oC relative to 25oC as well as using ammonium sulfate as the nitrogen source relative to urea or a combination of both. Total sugars ranged between 123.21mg/g at 50% initial moisture content to 374mg/g at 60% and from 190.59mg/g with particle size range of 2.00>p>1.41mm to 310.10mg/g with 4.00>p>3.35mm.True protein ranged from 229.70 mg/g at pH 4 to 284.05 mg/g at pH 6; from 200.87 mg/g with urea as nitrogen source and to 254.50mg/g with ammonium sulfate; from 213.82mg/g at 50% initial moisture content to 254.50mg/g at 60% moisture content, from 205.75mg/g in cassava peel with 5.6>p> 4.75mm to 268.30 in cassava peel with particle size 4.00>p>3.35mm, from 207.57mg/g at 25oC to 254.50mg/g at 30oC Cassava peel with particle size 4.00>p>3.35 mm and initial moisture content of 60% at pH 6.0, 30oC incubation temperature with ammonium sulfate (10g N / kg substrate) was most suitable for protein enrichment with Trichoderma viride. Crude protein increased from 4.21 % in unfermented cassava peel samples to 10.43 % in fermented samples.
Abstract: A novel thermo-sensitive superabsorbent hydrogel
with salt- and pH-responsiveness properties was obtained by grafting
of mixtures of acrylic acid (AA) and N-isopropylacrylamide
(NIPAM) monomers onto kappa-carrageenan, kC, using ammonium
persulfate (APS) as a free radical initiator in the presence of
methylene bisacrylamide (MBA) as a crosslinker. Infrared
spectroscopy was carried out to confirm the chemical structure of the
hydrogel. Moreover, morphology of the samples was examined by
scanning electron microscopy (SEM). The effect of MBA
concentration and AA/NIPAM weight ratio on the water absorbency
capacity has been investigated. The swelling variations of hydrogels
were explained according to swelling theory based on the hydrogel
chemical structure. The hydrogels exhibited salt-sensitivity and
cation exchange properties. The temperature- and pH-reversibility
properties of the hydrogels make the intelligent polymers as good
candidates for considering as potential carriers for bioactive agents,
e.g. drugs.
Abstract: It was analyzed of fatty acid composition of 16 strains
of microalgae lipid fractions isolated from different basins of
Kazakhstan and characterized by stable active growth in the
laboratory. Three species of green microalgae (Oocystis
rhomboideus, Chlorococcum infusionum, Dictyochlorella globosa)
and three species of diatoms (Synedra sp., Nitzshia sp., Pleurosigma
attenuatum) are characterized by a high content of lipids and are
promising for further study as a source of polyunsaturated fatty acids.
Abstract: L-system is a tool commonly used for modeling and simulating the growth of fractal plants. The aim of this paper is to join some problems of the computational geometry with the fractal geometry by using the L-system technique to generate fractal plant in 3D. L-system constructs the fractal structure by applying rewriting rules sequentially and this technique depends on recursion process with large number of iterations to get different shapes of 3D fractal plants. Instead, it was reiterated a specific number of iterations up to three iterations. The vertices generated from the last stage of the Lsystem rewriting process are used as input to the triangulation algorithm to construct the triangulation shape of these vertices. The resulting shapes can be used as covers for the architectural objects and in different computer graphics fields. The paper presents a gallery of triangulation forms which application in architecture creates an alternative for domes and other traditional types of roofs.
Abstract: Biodiesel production with used frying by
transesterification reaction with methanol, using a commercial
kaolinite thermally-activated solid acid catalyst was investigated.
The surface area, the average pore diameter and pore volume of the
kaolinite catalyst were 10 m2/g, 13.0 nm and 30 mm3/g, respectively.
The optimal conditions for the transesterification reaction were
determined to be oil/methanol, in a molar ratio 1:31, temperature 160
ºC and catalyst concentration of 3% (w/w). The yield of fatty acids
methyl esters (FAME) was 92.4% after 2 h of reaction. This method
of preparation of biodiesel can be a positive alternative for utilizing
used frying corn oil for feedstock of biodiesel combined with the
inexpensive catalyst.
Abstract: In this paper fatigue crack growth behavior of
aeronautical aluminum alloy 2024 T351 was studied. Effects of
various loading and geometrical parameters are studied such as stress
ratio, amplitude loading, etc. The fatigue crack growth with constant
amplitude is studied using the AFGROW code when NASGRO
model is used. The effect of the stress ratio is highlighted, where one
notices a shift of the curves of crack growth. The comparative study
between two orientations L-T and T-L on fatigue behavior are
presented and shows the variation on the fatigue life. L-T orientation
presents a good fatigue crack growth resistance. Effects of crack
closure are shown in Paris domain and that no crack closure
phenomenons are present at high stress intensity factor.
Abstract: Three strains of Vibrio parahaemolyticus (690, BCRC
13023 and BCRC 13025) implicated in food poisoning outbreaks in
Taiwan were subjected to acid adaptation at pH 5.5 for 90 min. The
growth behaviors of acid-adapted and non-adapted V.
parahaemolyticus in the media supplemented with various nitrogen
and carbon sources were investigated. The effects of acid adaptation
on the thermostable direct hemolysin (TDH) secretion and fatty acid
profiles of V. parahaemolyticus were also examined. Results showed
that acid-adapted and non-adapted V. parahaemolyticus 690, BCRC
13023 and BCRC 13025 grew similarly in TSB-3% NaCl and basal
media supplemented with various carbon and nitrogen sources during
incubation period. Higher TDH secretion was noted with V.
parahaemolyticus 690 among the three strains. However, acid-adapted
strains produced less amounts of TDH than non-adapted strains when
they were grown in TSB-3% NaCl. Additionally, acid adaptation
increased the ratio of SFA/USFA in cells of V. parahaemolyticus
strains.
Abstract: Scheduling for the flexible job shop is very important
in both fields of production management and combinatorial
optimization. However, it quit difficult to achieve an optimal solution
to this problem with traditional optimization approaches owing to the
high computational complexity. The combining of several
optimization criteria induces additional complexity and new
problems. In this paper, a Pareto approach to solve the multi
objective flexible job shop scheduling problems is proposed. The
objectives considered are to minimize the overall completion time
(makespan) and total weighted tardiness (TWT). An effective
simulated annealing algorithm based on the proposed approach is
presented to solve multi objective flexible job shop scheduling
problem. An external memory of non-dominated solutions is
considered to save and update the non-dominated solutions during
the solution process. Numerical examples are used to evaluate and
study the performance of the proposed algorithm. The proposed
algorithm can be applied easily in real factory conditions and for
large size problems. It should thus be useful to both practitioners and
researchers.
Abstract: One approach to assess neural networks underlying the cognitive processes is to study Electroencephalography (EEG). It is relevant to detect various mental states and characterize the physiological changes that help to discriminate two situations. That is why an EEG (amplitude, synchrony) classification procedure is described, validated. The two situations are "eyes closed" and "eyes opened" in order to study the "alpha blocking response" phenomenon in the occipital area. The good classification rate between the two situations is 92.1 % (SD = 3.5%) The spatial distribution of a part of amplitude features that helps to discriminate the two situations are located in the occipital regions that permit to validate the localization method. Moreover amplitude features in frontal areas, "short distant" synchrony in frontal areas and "long distant" synchrony between frontal and occipital area also help to discriminate between the two situations. This procedure will be used for mental fatigue detection.
Abstract: This paper presents a ray tracing simulation technique for characterize the radiowave propagation inside building. The implementation of an algorithm capable of enumerating a large number of propagation paths in interactive time for the special case of 2.5D. The effective dielectric constants of the building structure in the simulations are indicated. The study describes an efficient 2.5D model of ray tracing algorithm were compared with 3D model. The result of the first investigations is that the environment of the indoor wave significantly changes as we change the electric parameters of material constructions. A detailed analysis of the dependence of the indoor wave on the wideband characteristics of the channel: root mean square (RMS) delay spread characteristics and Mean excess delay, is also investigated.
Abstract: Currently, there is no database or local norms for the
physical performance of Malaysian rugby players. This database or
norms are vital for Malaysian-s sports development as programs can
be setup to improve the current status. This pilot study was
conducted to evaluate the status of our semi professional rugby
players. The rugby players were randomly selected from the
Malaysian National team and several clubs in the Klang valley, Kuala
Lumpur Malaysia. 54 male rugby players (Age: 24.41 ± 4.06 years)
were selected for this pilot study. Height, bodyweight, percentage
body fat and body mass index (BMI) and several other physical tests
were performed. Results from the BLEEP test revealed an average of
level 9, shuttle 2 for the players. Interestingly, forwards were taller,
heavier, and had lower maximal aerobic power than backs in the
same team. In conclusion, the physical characteristics of the rugby
players were much lower when compared to international players
from other countries. From this pilot study, the physical performance
of the Malaysian team must be improved in order to further develop
the sports.
Abstract: Hydrogenated biodiesel is one of the most promising
renewable fuels. It has many advantages over conventional biodiesel,
including higher cetane number, higher heating value, lower
viscosity, and lower corrosiveness due to its absence of oxygen.
From previous work, Pd/TiO2 gave high conversion and selectivity in
hydrogenated biodiesel. In this work, the effect of biomass feedstocks
(i.e. beef fat, chicken fat, pork fat, and jatropha oil) on the production
of hydrogenated biodiesel over Pd/TiO2 has been studied. Biomass
feedstocks were analyzed by ICP-OES (inductively coupled plasma
optical emission spectrometry) to identify the content of impurities
(i.e. P, K, Ca, Na, and Mg). The deoxygenation catalyst, Pd/TiO2,
was prepared by incipient wetness impregnation (IWI) and tested in a
continuous flow packed-bed reactor at 500 psig, 325°C, H2/feed
molar ratio of 30, and LHSV of 4 h-1 for its catalytic activity and
selectivity in hydrodeoxygenation. All feedstocks gave high
selectivity in diesel specification range hydrocarbons and the main
hydrocarbons were n-pentadecane (n-C15) and n-heptadecane (n-
C17), resulting from the decarbonylation/decarboxylation reaction.
Intermediates such as oleic acid, stearic acid, palmitic acid, and esters
were also detected in minor amount. The conversion of triglycerides
in jatropha oil is higher than those of chicken fat, pork fat, and beef
fat, respectively. The higher concentration of metal impurities in
feedstock, the lower conversion of feedstock.
Abstract: Technical laboratories are typically considered as
highly hazardous places in the polytechnic institution when
addressing the problems of high incidences and fatality rates. In
conjunction with several topics covered in the technical curricular,
safety and health precaution should be highlighted in order to
connect to few key ideas of being safe. Therefore the assessment of
safety awareness in terms of safety and health about hazardous and
risks at laboratories is needed and has to be incorporated with
technical education and other training programmes. The purpose of
this study was to determine the efficacy of technical laboratory safety
in one of the polytechnics in northern region. The study examined
three related issues that were; the availability of safety material and
equipment, safety practice adopted by technical teachers and
administrator-s safety attitudes in enforcing safety to the students. A
model of efficacy technical laboratory was developed to test the
linear relationship between existing safety material and equipment,
teachers- safety practice and administrators- attitude in enforcing
safety and to identify which of technical laboratory safety issues was
the most pertinent factor to realize safety in technical laboratory.
This was done by analyzing survey-based data sets particularly those
obtained from samples of 210 students in the polytechnic. The
Pearson Correlation was used to measure the association between the
variables and to test the research hypotheses. The result of the study
has found that there was a significant correlation between existing
safety material and equipment, safety practice adopted by teacher
and administrator-s attitude. There was also a significant relationship
between technical laboratory safety and safety practice adopted by
teacher and between technical laboratory safety and administrator
attitude. Hence, safety practice adopted by teacher and administrator
attitude is vital in realizing technical laboratory safety.
Abstract: A thirty Rahmani weaned male lambs of average body weight (27.28±1.40 kg) were randomly allotted to three similar groups, ten lambs in each, to study the benefit of commercial feed additives Tonilisat (Saccharomyces cerevisiae) and Roemin W2 (Lactobacillus acidophilus, Lactobacillus thermophilus, Bifidobacterium and Lactose) as growth promoters on lambs performance, digestibility, rumen activity and some blood constituents. The experiment lasted about 107 days. Three experimental groups were allotted as control group: received the basal ration, T1 group: received the basal ration supplemented with Tonilisat as (0.5kg/ ton concentrate feed mixture) and T2 group: received the basal ration supplemented with Roemin W2 (1kg/ ton concentrate feed mixture). Our study revealed that addition of Tonilisat significantly increased digestion coefficient of crude protein than that of the control group, Furthermore, the supplementation of Tonilisat or Roemin W2 increased (p