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International Journal of Research and Reviews in Applied Sciences
ISSN: 2076-734X, EISSN: 2076-7366
Volume 24, Issue 2(August, 2015)
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1. |
A PROCEDURE TO DETERMINE THE INTRINSIC MODEL OF CNTFETs FOR RF APPLICATIONS |
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by Roberto Marani & Anna Gina Perri |
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Abstract |
The aim of this paper is
to present a procedure to determine the intrinsic model of Carbon NanoTube Field Effect Transistors (CNTFETs)
for RF applications.
In particular an active model, deduced from S parameters measurements, already proposed by us, is examined. Moreover, through a de-embedding procedure, which
allows to remove random errors in measured S parameters of small-signal device, we evaluate the
intrinsic model of CNTFETs to implement
directly in simulation software.
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Source: |
International Journal of Research and Reviews in Applied Sciences
August 2015-- Vol. 24 Issue 2 -- 2015 |
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2. |
SOUND ABSORPTION SYSTEMS WITH THE COMBINATION OF A MICROPERFORATED PANEL (MPP), PERMEABLE MEMBRANE AND POROUS MATERIAL: SOME IDEAS TO IMPROVE THE ACOUSTIC PERFORMANCE OF MPP SOUND ABSORBERS |
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by Kimihiro Sakagami
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Abstract |
A microperforated panel (MPP) is one of the most promising
and attractive alternatives among various type next-generation sound absorbers.
However, an MPP absorber has a shortcoming that its absorption frequency range is
limited into the resonance frequency range. In order to overcome this problem, various
attempts to make it more wideband since it was proposed. The authors also have tried
to make it wideband in our previous studies. Among them, a simple alternative is
to use MPPs with a permeable membrane and/or porous absorbent. In this
article,
a review
introducing
the
main results of the
studies in the author’s group
on sound absorbing
structures composed of an MPP, permeable membrane and/or porous absorbent,
as attempts to improve MPP absorbers, is presented. Even in the case of a
simple MPP absorber,
a permeable membrane or porous absorbent in its back-cavity are
useful to make a
more wideband sound absorber. In this review,
also some
more complex sound absorbing system including MPPs, permeable membranes and porous
absorbents are introduced and the basic idea is given.
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Source: |
International Journal of Research and Reviews in Applied Sciences
August 2015-- Vol. 24 Issue 2 -- 2015 |
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3. |
INVESTIGATION INTO THE USE OF MICROSILICA AND FLY ASH IN SELF COMPACTING CONCRETE |
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by Victor Ajileye Faseyemi |
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Abstract |
This research work presents the results of an experiment investigation into the
use of microsilica and fly ash in self compacting concrete. In this study the microsilica
and fly ash used in various proportions 10%, 8%, 6%, 4% & 2% together with that
of fly ash 35%, 30%, 25% 15% & 10% y weight of cement. The mix proportions of
normal concrete had a water/cement ratio of 0.4 while for self compacting concrete
had a water/cement ratio from 0.35 to 0.30.
Super plasticizer and rheomatix III
was used as viscous modifier. Water demand increases in proportion to the amount
of microsilica added. The total binder ratio was 450kg/m3. The self compacting
concrete (SCC) specimens were cured on temperature of 20±20. The compressive
strengths were determined at various ages up to 56 days i.e 3,7,28 and 56 days.
Various tests were conducted on fresh self-compacting concrete i.e slump flow, V-funnel
test, L- Box test and results were recorded down. The specific gravity and chemical
composition of fly ash, microsilica and cement were determined. Cubes (150 X 150
X 150mm) were used to determine the compressive strength, density of self compacting
concrete. The specific gravity of the fly ash was 2.1, microsilica was 2.0 and cement
was 3.15. The total amount of SiO2, Al2O3 and Fe2O3
in fly ash was 67.1% which was above the minimum requirement (50% min.) specified
by ASTM C 618 for fly ash. Both chemical compositions for microsilca, fly ash were
in compliance with ASTM C 1240 while cement was in compliance with BS12/EN 196:1996.
The density of the concrete decreased with increase in percentage of microsilica
and fly ash replacement. Increase in the level of fly ash and microsilica replacement
led to an increase in the compressive strength of the hardened self compacting concrete
up to 10% ash and 2% microsilica while up to 30% fly ash and 10% microsilica in
cement replacement of self compacting concrete led to reduction in the compressive
strength of hardened concrete at 3, 7, 28 & 56days. Based upon the experimental
results, there was a relationship between workability and strength of self compacting
concrete with 10% fly ash & 4% microsilica, 15% fly ash & 6% microsilica
with viscous modifiers in comparism with the control.
This study shows that microsilica and fly ash at 2% and 10% replacement in self
compacting concrete was the best design and it developed strength sufficient for
construction purposes. These replacements led to a reduction in cement quantity
required for construction purposes and hence enhance sustainability in the construction
as well as aid economic construction.
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Source: |
International Journal of Research and Reviews in Applied Sciences
August 2015-- Vol. 24 Issue 2 -- 2015 |
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4. |
WAVE SOLUTIONS IN TWO-COMPONENT NONLINEAR DIFFUSION SYSTEMS OF KOLMOGOROV-FISHER TYPE BIOLOGICAL POPULATION TASK |
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by Dildora Muhamediyeva
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Abstract |
In the present work investigated
the properties of solutions of the problem of biological populations of the Kolmogorov-Fisher
dual nonlinear cross-diffusion, describing nonlinear processes in two-component
nonlinear media in the presence of convective diffusion, the speed of which depends
on the
time. It is shown that in such models there is the phenomenon of localization
solutions. Obtained the asymptotics of the finite vanishing at infinity of solutions.
Suggested suitable initial approximation for fast covergence iterative process.
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Source: |
International Journal of Research and Reviews in Applied Sciences
August 2015-- Vol. 24 Issue 2 -- 2015 |
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5. |
A COMPARATIVE EXPERIMENTAL STUDY BETWEEN THE BIODIESELS OF JATROPHA AND PALM OILS BASED ON THEIR PERFORMANCE AND EMISSIONS IN A FOUR STROKE DIESEL ENGINE |
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by Deepesh Nagar, Sumeet Sharma, S.K. Mohapatra & K. Kundu |
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Abstract |
Stringent emission norms and depletion of oil resources have led the researchers
to find
alternative fuels for internal combustion
engines. The main objectives of this study are to investigate the
effects of using different types of fuel samples in terms of emission characteristics
and feasibility of using alternative
fuels. A total of four fuel samples, such as 100% diesel fuel (D100); 20% jatropha
biodiesel and 80% diesel fuel (JB20); 20% palm
biodiesel and 80% diesel fuel (PB20); and 10% jatropha biodiesel, 10%
palm biodiesel and 80% diesel fuel (JPB20)
respectively were used to analyze the
performance on the basis of brake specific fuel consumption, brake thermal efficiency
and exhaust gas temperature and exhaust emissions
referring to carbon monoxide, carbon dioxide,
and oxides of nitrogen. Short-term
engine performance tests are conducted on a single-cylinder, four-stroke, variable
compression ratio, compression ignition engine using the
four fuel samples mentioned above at load of 0, 2, 4, 6, 8 Kg and at
compression ratios of 12, 14, 16. It is found from the results that biodiesels differ
very little from diesel in performance and are better than diesel with regard to
hydrocarbon and carbon monoxide emissions. However oxides of nitrogen are found
to be higher for biodiesels but not significantly higher when compared with diesel.
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Source: |
International Journal of Research and Reviews in Applied Sciences
August 2015-- Vol. 24 Issue 2 -- 2015 |
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