| Title: |
Stability
analysis of circular pressure dam hydrodynamic journal bearing
with couple stress lubricant |
| Author (s): |
N. P. Mehta,
S. S. Rattan and Rajiv Verma |
| Abstract: |
A generalized Reynolds equation
has been derived for carrying out the stability analysis of a
plain circular pressure dam hydrodynamic bearing operating
with couple stress fluids. The Galerkin form of the finite
element method has been used to solve the equation obtained. A
non-dimensional parameter, ‘l’ has been used to
indicate the length of the long chain polymer added to the
bulk Newtonian fluid. The dynamic characteristics, which have
been calculated for a wide range of dam parameters, have been
found to be greatly influenced with the variation of the
couple stress parameter ‘l’. The critical mass of the
journal, obtained as a solution to the linearized equations of
motion is used to demonstrate the increased stability of the
journal bearing system. |
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| Title: |
Strength
appraisal of artificial sand as fine aggregate in SFRC |
| Author (s): |
Mahendra R.
Chitlange and Prakash S. Pajgade |
|
Abstract: |
The huge quantity concrete is
consumed by the construction industry all over the world,
probably second largest after water. In India, the
conventional concrete is produced by using natural sand from
riverbeds as fine aggregate. Dwindling sand resources poses
the environmental problem and hence government restrictions on
sand quarrying resulted in scarcity and significant increase
in its cost. This paper presents the study of steel fiber
reinforced concrete with artificial sand as fine aggregate.
Three matrices with compressive strength 20, 30 and 40 MPa
were designed and reinforced with crimpled steel fibers at
dosage rate of volume fraction 0, 0.5, 1.0, 1.5 and 2.0
percent. The specimens were prepared, cured and tested for
compressive strength, flexural strength and split tensile
strength. The strength of steel fiber reinforced natural sand
concrete (SFRNSC) and steel fiber reinforced artificial sand
concrete (SFRASC) have been compared with the test data from
the present study. The promotional use of artificial sand will
conserve the natural resources for the sustainable development
of the concrete in construction industry. |
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| Title: |
A comparative study of diagonal updating Newton methods for
systems of nonlinear equations with singular Jacobian |
| Author (s): |
Mohammed waziri Yusuf and Ibrahim Saidu |
|
Abstract: |
We have compared the efficiency of two diagonal updating
Newton methods for solving systems of nonlinear equations with
singular Jacobian. Due to the fact that, the quadratic rate of
convergence of Newton method for solving nonlinear systems of
equations depends on when the Jacobian is nonsingular in the
neighborhood of the solution. Contrary to this condition, i.e.
the Jacobian to be singular the convergence is very slow and
may even vanished. The two approaches are simple and straight
forward to implement. We report on numerous numerical
experiments which show that, the proposed algorithms are very
efficient and reliable. |
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| Title: |
A recursive
procedure for commensal- host ecological model with
replenishment rate for both the species - A numerical approach |
| Author (s): |
N. Phani
Kumar and N. Ch. Pattabhi Ramacharyulu |
| Abstract: |
In this paper a four stage
recursive procedure is adopted to give an approximate solution
to the mathematical model equations of a commensal-host
ecological model with replenishment rate for both species.
Numerical examples are discussed to explain the trajectories
of the solutions and the results are illustrated. |
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|
| Title: |
Evaluation of
the parameters affecting the solvent extraction of soybean oil |
| Author (s): |
Lawson O. S.,
Adefemi O., Ologunagba F. O. and Ojomo A. O. |
|
Abstract: |
Soybean is grown primarily for
its protein content and secondarily for its oil; it is an
excellent protein supplement for enriching cereal diet. The
primary processing of soybean before oil extraction include
cleaning, cracking, flaking and conditioning, these ruptures
the oil cells, for efficient extraction. Most modern oil
extraction industries use the solvent extraction process and
the solvent commonly used is the food grade hexane. In this
paper detail experiments were carried out on the various
processing parameters affecting the solvent extraction of
soybean oil. Among the process factors considered are:
particle size, flakes thickness, temperature of extraction,
extraction time, flakes and particle moisture content. The
results showed that, at a particle size of 2mm, flakes
thickness of 0.25mm, and moisture content of 12-13%, at
temperature of 69▫c and the extraction time between 3˝ and 4 ˝
hours the oil yield was maximum. |
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| Title: |
Performance
of DVR under different voltage sag and swell conditions |
| Author (s): |
T. Devaraju,
V. C. Veera Reddy and M. Vijaya Kumar |
|
Abstract: |
The problem of voltage
sags and Swells and its severe impact on sensitive loads is
well known. To solve this problem, custom power devices are
used. One of those devices is the Dynamic Voltage Restorer (DVR),
which is one of the most efficient and effective modern custom
power devices used in power distribution networks.
This paper described
DVR principles and voltage correction methods for balanced
and/or unbalanced voltage sags and swells in a distribution
system. Simulation results were presented to illustrate and
understand the performances of DVR under voltage sags/swells
conditions. The results obtained by simulation using MATLAB
confirmed the effectiveness of this device in compensating
voltage sags and swells with very fast response (relative to
voltage sag/swell time). |
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| Title: |
An evaluation
of the factors influence the electric power production from
biomass in the certain area of Kavala, Greece |
| Author (s): |
C. Potolias,
E. Stathakis, D.V. Bandekas and N. Vordos |
|
Abstract: |
This paper deals with the
issue of whether then are benefits in establishing an
electric power production plant (EPPP) using biomass as fuel
in a certain geographical area (prefecture of Kavala/ Greece)
taking into account nine certain factors that strongly
influence and determine the final decision about the
capacity/size and viability/feasibility of the EPPP unit
proposed. Using the M. Falia Model we concluded that a certain
capacity’s EPPP can be established in prefecture of Kavala being viable and
profitable. The nine factors used in the model are: 1. The
extent of area capable to produce the biomass required for the
EPPP operation; 2. The quantity of biomass required; 3. The
plant mix of biomass; 4. The quality of biomass defined
international standards; 5. The net thermal value 6. The
ex-factory total unit cost of biomass used as «fuel»; 7. The
environmental benefits quantified by us; 8. The total
investment cost for the EPPP; 9. The real discount rate or
International Rate of Return (IRR). The model uses the EPPP
capacity as dependent variable and the nine factors as
independent ones, resulted in an optimal solution about the
feasibility of establishing an EPPP unit in the certain area
of Kavala prefecture.
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| Title: |
Effect of
silica fume additions on porosity of fly ash geopolymers |
| Author (s): |
Debabrata
Dutta, Suresh Thokchom, Partha Ghosh and Somnath Ghosh |
|
Abstract: |
This paper presents the results
of an experimental study performed to investigate effect of
incorporating silica fume in the fly ash geopolymer on its
porosity and compressive strength. Geopolymer specimens were
prepared by activating fly ash incorporated with additional
silica fume in the range of 2.5% to 5% with a mixture of
Sodium hydroxide and Sodium silicate having Na2O
content of 8%. The characterization of the geopolymer
specimens was done with SEM/EDAX and MIP tests. Addition of
silica fume up to 5% enhanced compressive strength. However,
further increase of silica fume caused a decrease in
compressive strength. SEM micrographs for specimens
incorporated with silica fume showed better microstructure and
exhibited lesser porosity. MIP results of paste specimens
indicate higher pore volume in the specimen prepared with
additional silica fume while for mortar specimens; the pore
volume was seen lesser in specimens with additional silica
fume. Silica fume may be used as an additional material to
improve or modify some properties of the resulting geopolymer. |
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|
| Title: |
Effect of
methyl esters of neem and diesel oil blends on the combustion
and emission characteristics of a CI engine |
| Author (s): |
Elango T. and
Senthilkumar T. |
|
Abstract: |
The depletion of oil resources
as well as the stringent environmental regulations has led to
the development of alternate energy sources. In this work the
combustion, performance and emission characteristics of a
single cylinder diesel engine when fuelled with blends of neem
and diesel oil are evaluated. Experiments were conducted with
different blends of neem oil and diesel at various loads. The
results show that the variations in the peak pressures of all
the blends at full load are marginal. There is an increase in
the ignition delay with biodiesel because of its high
viscosity and density. It is found that the brake thermal
efficiency of diesel is higher at all loads followed by blends
of neem oil and diesel. The maximum brake thermal efficiency
and minimum specific fuel consumption were found for blends
upto B20. The specific fuel consumption, exhaust gas
temperature, smoke opacity and NOx were comparatively higher.
However there is an appreciable decrease in HC and CO2
emissions while the decrease in CO emission is marginal. It
was observed that the combustion characteristics of the blends
of esterified neem oil with diesel followed closely with that
of the base line diesel. |
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|
| Title: |
MHD effects on convective flow of dusty viscous fluid with
volume fraction |
| Author (s): |
Ibrahim Saidu, Mohammed W. Y., Abubakar Roko and Hamisu Musa |
|
Abstract: |
The problem of laminar convective flow of an incompressible,
conducting, viscous fluid embedded with non-conducting dust
particles in the presence of uniform magnetic field and
constant pressure gradient taking volume fraction of a dust
particles into account when one plate of the channel is fixed
and the other is oscillating in time and magnitude about a
constant non-zero mean is formulated. Solutions are obtained
for the velocity of fluid, dust particles and the fluid
temperature within the channel. The effects of various
parameters on the velocities are shown graphically and
discussed. It is found that both the velocity of the liquid
and dust particles decreases with the increase in the porous
parameter. |
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|
| Title: |
Hydraulic
hysteresis effect on compressibility of unsaturated soils |
| Author (s): |
Anuchit
Uchaipichat |
|
Abstract: |
An experimental program of
laboratory testing on a compacted kaolin in a modified
triaxial cell was perform to investigate the effect of
hydraulic hysteresis on a loading collapse curve of
unsaturated soils. The test data are presented on a range of
constant suction isotropic loading tests along wetting and
drying paths. The effect of hydraulic hysteresis on the
compression curves at different values of matric suction and
the loading collapse curves was observed. The loading collapse
curve also indicates a constant value of effective
preconsolidation pressure with decreasing matric suction along
the wetting scanning curve. |
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