Abstract: This paper presents the results of a Finite Element
based vibration analysis of a solar powered Unmanned Aerial
Vehicle (UAV). The purpose of this paper was to quantify the free
vibration, forced vibration response due to differing point inputs in
order to predict the relative response magnitudes and frequencies at
various wing locations of vibration induced power generators
(magnet in coil) excited by gust and/or control surface pulse-decays
used to help power the flight of the electric UAV. A Fluid Structure
Interaction (FSI) study was performed in order to ascertain pertinent
design stresses and deflections as well as aerodynamic parameters of
the UAV airfoil. The 10 ft span airfoil is modeled using Mylar as the
primary material. Results show that the free mode in bending is 4.8
Hz while the first forced bending mode is on range of 16.2 to 16.7 Hz
depending on the location of excitation. The free torsional bending
mode is 28.3 Hz, and the first forced torsional mode is range of 26.4
to 27.8 Hz, depending on the location of excitation. The FSI results
predict the coefficients of aerodynamic drag and lift of 0.0052 and
0.077, respectively, which matches hand-calculations used to validate
the Finite Element based results. FSI based maximum von Mises
stresses and deflections were found to be 0.282 MPa and 3.4 mm,
respectively. Dynamic pressures on the airfoil range from 1.04 to
1.23 kPa corresponding to velocity magnitudes in range of 22 to 66
m/s.
Abstract: A teeming set of doctors that graduated from various
universities within and outside Nigeria with the hope of practicing in
the country, has their hope shattered because of poor financing, lack
of medical equipments and a very weak healthcare systems. Such
hydra headed challenges, allows room for quackery which
increasingly contributes to the cause of mortality in Nigeria. With a
view of reversing the challenges of healthcare delivery and financing
in Nigeria, African Health Market for Equity (AHME), a project
funded by the Bill and Melinda Gates foundation [With contribution
from Department For International Development (DFID)] and
currently implemented in three African Countries (Nigeria, Kenya
and Ghana) over a Five (5) year period supports the healthcare sector
via Medical credit fund (MCF). The study examines the impact of
credit policy and medical credit funding on Nigerian health market.
Ordinary least square analysis, correlation and granger causality tests
were employed to measure the extent to which the Nigerian
healthcare market has been influenced. Medical credit fund
significantly and positively influenced average monthly turnover of
private healthcare providers and Commercial bank’s lending rate had
a weak relationship with access to credit/approved loans (13.46%).
The programme has so far made 13.91% progress, which is very
poor, considering the minimum targeted private health care providers
(437.6) and expected number of loan approvals (180.4) for the two
years. Medical credit policy in Nigeria should be revised to include
private healthcare providers in rural area for more positive impact
and increased returns. Good brand advert and sensitization of the
programme to stakeholders and health pressure group, and an
extension of the programme beyond five years is necessary to better
address the issues raised in the study.
Abstract: This paper presents the modeling approach in SBO
sequence for VVER 1000 reactors and describes the reactor core
behavior at late in-vessel phase in case of late reflooding by HPIS
and gives preliminary results for the ASTECv2 validation. The work
is focused on investigation of plant behavior during total loss of
power and the operator actions. The main goal of these analyses is to
assess the phenomena arising during the Station blackout (SBO)
followed by primary side high pressure injection system (HPIS)
reflooding of already damaged reactor core at very late “in-vessel”
phase. The purpose of the analyses is to define how the later HPIS
switching on can delay the time of vessel failure or possibly avoid
vessel failure. The times for HPP injection were chosen based on
previously performed investigations.
Abstract: In this study, failure analysis of pipe system at a micro
hydroelectric power plant is investigated. Failure occurred at the pipe
system in the powerhouse during shut down operation of the water
flow by a valve. This locking had caused a sudden shock wave, also
called “Water-hammer effect”, resulting in noise and inside pressure
increase. After visual investigation of the effect of the shock wave on
the system, a circumference crack was observed at the pipe flange
weld region. To establish the reason for crack formation, calculations
of pressure and stress values at pipe, flange and welding seams were
carried out and concluded that safety factor was high (2.2), indicating
that no faulty design existed. By further analysis, pipe system and
hydroelectric power plant was examined. After observations it is
determined that the plant did not include a ventilation nozzle (air
trap), that prevents the system of sudden pressure increase inside the
pipes which is caused by water-hammer effect. Analyses were carried
out to identify the influence of water-hammer effect on inside
pressure increase and it was concluded that, according Jowkowsky’s
equation, shut down time is effective on inside pressure increase. The
valve closing time was uncertain but by a shut down time of even one
minute, inside pressure would increase by 7.6 bar (working pressure
was 34.6 bar). Detailed investigations were also carried out on the
assembly of the pipe-flange system by considering technical
drawings. It was concluded that the pipe-flange system was not
installed according to the instructions. Two of five weld seams were
not applied and one weld was carried out faulty. This incorrect and
inadequate weld seams resulted in; insufficient connection of the pipe
to the flange constituting a strong notch effect at weld seam regions,
increase in stress values and the decrease of strength and safety
factor.
Abstract: Recently attention has been focused on incomplete
spinal cord injuries (SCI) to the central spine caused by pressure on
parts of the white matter conduction pathway, such as the pyramidal
tract. In this paper, we focus on a training robot designed to assist with
primary walking-pattern training. The target patient for this training
robot is relearning the basic functions of the usual walking pattern; it is
meant especially for those with incomplete-type SCI to the central
spine, who are capable of standing by themselves but not of
performing walking motions. From the perspective of human
engineering, we monitored the operator’s actions to the robot and
investigated the movement of joints of the lower extremities, the
circumference of the lower extremities, and exercise intensity with the
machine. The concept of the device was to provide mild training
without any sudden changes in heart rate or blood pressure, which will
be particularly useful for the elderly and disabled. The mechanism of
the robot is modified to be simple and lightweight with the expectation
that it will be used at home.
Abstract: The application of cold Radio-Frequency (RF) plasma
in the conservation of cultural heritage became important in the last
decades due to the positive results obtained in decontamination
treatments. This paper presents an equipment especially designed for cold RF
plasma application on paper documents, developed within a research
project. The equipment consists in two modules: the first one is
designed for decontamination and cleaning treatments of any type of
paper supports, while the second one can be used for coating friable
papers with adequate polymers, for protection purposes. All these
operations are carried out in cold radio-frequency plasma, working in
gaseous nitrogen, at low pressure. In order to optimize the equipment parameters ancient paper
samples infested with microorganisms have been treated in nitrogen
plasma and the decontamination effects, as well as changes in surface
properties (color, pH) were assessed. The microbiological analysis
revealed complete decontamination at 6 minutes treatment duration;
only minor modifications of the surface pH were found and the
colorimetric analysis showed a slight yellowing of the support.
Abstract: In this paper numerical studies have been carried out
to examine the pre-ignition flow features of high-performance solid
propellant rocket motors with two different port geometries but with
same propellant loading density. Numerical computations have been
carried out using a validated 3D, unsteady, 2nd-order implicit, SST k-
ω turbulence model. In the numerical study, a fully implicit finite
volume scheme of the compressible, Reynolds-Averaged, Navier-
Stokes equations is employed. We have observed from the numerical
results that in solid rocket motors with highly loaded propellants
having divergent port geometry the hot igniter gases can create preignition
pressure oscillations leading to thrust oscillations due to the
flow unsteadiness and recirculation. We have also observed that the
igniter temperature fluctuations are diminished rapidly thereby
reaching the steady state value faster in the case of solid propellant
rocket motors with convergent port than the divergent port
irrespective of the igniter total pressure. We have concluded that the
prudent selection of the port geometry, without altering the propellant
loading density, for damping the total temperature fluctuations within
the motor is a meaningful objective for the suppression and control of
instability and/or thrust oscillations often observed in solid propellant
rocket motors with non-uniform port geometry.
Abstract: A new design of aerostatic thrust bearing is proposed
for high static stiffness. The bearing body, which is mead of polymer
covered with metallic membrane, is held by a circular ring. Such a
support helps form a concave air gap to grasp the air pressure. The
polymer body, which can be made rapidly by either injection or
molding is able to provide extra damping under dynamic loading. The
smooth membrane not only serves as the bearing surface but also
protects the polymer body. The restrictor is a capillary inside a silicone
tube. It can passively compensate the variation of load by expanding
the capillary diameter for more air flux. In the present example, the
stiffness soars from 15.85 N/μm of typical bearing to 349.85 N/μm at
bearing elevation 9.5 μm; meanwhile the load capacity also enhances
from 346.86 N to 704.18 N.
Abstract: Traditional mechanical control systems in thrust
vectoring are efficient in rocket thrust guidance but their costs
and their weights are excessive. The fluidic injection in the nozzle
divergent constitutes an alternative procedure to achieve the goal. In
this paper, we present a 3D analytical model for fluidic injection
in a supersonic nozzle integrating an orifice. The fluidic vectoring
uses a sonic secondary injection in the divergent. As a result, the
flow and interaction between the main and secondary jet has built in
order to express the pressure fields from which the forces and thrust
vectoring are deduced. Under various separation criteria, the present
analytical model results are compared with the existing numerical
and experimental data from the literature.
Abstract: This paper presents a study on the effect of
second-order slip and jump on forced convection through a long
isothermally heated or cooled planar microchannel. The fully
developed solutions of thermal flow fields are analytically obtained on
the basis of the second-order Maxwell-Burnett slip and Smoluchowski
jump boundary conditions. Results reveal that the second-order term in
the Karniadakis slip boundary condition is found to contribute a
negative velocity slip and then to lead to a higher pressure drop as well
as a higher fluid temperature for the heated-wall case or to a lower
fluid temperature for the cooled-wall case. These findings are contrary
to predictions made by the Deissler model. In addition, the role of
second-order slip becomes more significant when the Knudsen
number increases.
Abstract: The LSTF experiment simulating the SGTR accident at
the Mihama Unit-2 reactor is analyzed using the RELAP5/MOD3.3
code. In the accident, and thus in the experiment, the ECC water was
injected not only into the cold legs but into the upper plenum. Overall
transients during the experiment such as pressures and fluid
temperatures are simulated well by the code. The cold-leg fluid
temperatures are shown to decrease if the upper plenum injection
system is connected to the cold leg. It is found that the cold-leg fluid
temperatures also decrease if the upper-plenum injection is not used
and the cold-leg injection alone is actuated.
Abstract: Below-knee amputees commonly experience
asymmetrical gait patterns. It is generally believed that ischemia is
related to the formation of pressure sores due to uneven distribution
of forces. Micro-vascular responses can reveal local malnutrition.
Changes in local skin blood supply under various external loading
conditions have been studied for a number of years. Radionuclide
clearance, photo-plethysmography, trans-cutaneous oxygen tension
along with other studies showed that the blood supply would be
influenced by the epidermal forces, and the rate and the amount of
blood supply would decrease with increased epidermal loads being
shear forces or normal forces. Several cases of socket designs were
investigated using Finite Element Model (FEM) and Design of
Experiment (DOE) to increase flexibility and minimize the pressure
at the limb/socket interface using ultra high molecular weight
polyethylene (UHMWPE) and polyamide 6 (PA6) or Duraform. The
pressure reliefs at designated areas where reducing thickness is
involved are seen to be critical in determination of amputees’ comfort
and are very important to clinical applications. Implementing a hole
between the Patellar Tendon (PT) and Distal Tibia (DT) would
decrease stiffness and increase prosthesis range of motion where
flexibility is needed. In addition, displacement and prosthetic energy
storage increased without compromising mechanical efficiency and
prosthetic design integrity.
Abstract: This paper presents a fully Lagrangian coupled
Fluid-Structure Interaction (FSI) solver for simulations of
fluid-structure interactions, which is based on the Moving Particle
Semi-implicit (MPS) method to solve the governing equations
corresponding to incompressible flows as well as elastic structures.
The developed solver is verified by reproducing the high velocity
impact loads of deformable thin wedges with three different materials
such as mild steel, aluminium and tin during water entry. The present
simulation results for aluminium are compared with analytical solution
derived from the hydrodynamic Wagner model and linear Wan’s
theory. And also, the impact pressure and strain on the water entry
wedge with three different materials, such as mild steel, aluminium
and tin, are simulated and the effects of hydro-elasticity are discussed.
Abstract: This study presents three different approaches to
estimate bubble point pressures for the binary system of CO2 and
ethyl palmitate fatty acid ethyl ester. The first method involves the
Peng-Robinson (PR) Equation of State (EoS) with the conventional
mixing rule of Van der Waals. The second approach involves the PR
EOS together with the Wong Sandler (WS) mixing rule, coupled with
the UNIQUAC GE model. In order to model the bubble point
pressures with this approach, the volume and area parameter for ethyl
palmitate were estimated by the Hansen group contribution method.
The last method involved the Peng-Robinson, combined with the
Wong-Sandler method, but using NRTL as the GE model. Results
using the Van der Waals mixing rule clearly indicated that this
method has the largest errors among all three methods, with errors in
the range of 3.96-6.22%. The PR-WS-UNIQUAC method exhibited
small errors, with average absolute deviations between 0.95 to 1.97
percent. The PR-WS-NRTL method led to the least errors, where
average absolute deviations ranged between 0.65-1.7%.
Abstract: A solar dish collector has been designed, fabricated
and tested for its performance on 10-03-2015 in Salem, Tamilnadu,
India. The experiments on cooking vessels of coated and un-coated
with 5 Liters capacity have been used for cooking Rice. The results
are shown in graphs. The solar cooker is always capable of cooking
food within the expected length of time and based on the solar
radiation levels. With minimum cooking power, the coated pressure
cooker of 5 Liters capacity cooks the food at faster manner. This is
due to the conductivity of the coating material provided in the cooker.
Abstract: New environmental regulations and the increasing
market preference for companies that respect the ecosystem had
encouraged the industry to look after new treatments for its effluents.
The sugar industry, one of the largest emitter of environmental
pollutants, follows this tendency. Membrane technology is
convenient for separation of suspended solids, colloids and high
molecular weight materials that are present in a wastewater from
sugar industry. The idea is to microfilter the wastewater, where the
permeate passes through the membrane and becomes available for
recycle and re-use in the sugar manufacturing process. For
microfiltration of this effluent a tubular ceramic membrane was used
with a pore size of 200 nm at transmembrane pressure in range of 1–3
bars and in range of flow rate of 50–150 l/h. Kenics static mixer was
used for permeate flux enhancement. Turbidity and suspended solids
were removed and the permeate flux was continuously monitored
during the microfiltration process. The flux achieved after 90 minutes
of microfiltration was in a range of 50–70 l/m2h. The obtained
turbidity decrease was in the range of 50-99 % and total amount of
suspended solids was removed.
Abstract: Indonesia has experienced annual forest fires that have
rapidly destroyed and degraded its forests. Fires in the peat swamp
forests of Riau Province, have set the stage for problems to worsen,
this being the ecosystem most prone to fires (which are also the most
difficult, to extinguish). Despite various efforts to curb deforestation,
and forest degradation processes, severe forest fires are still
occurring. To find an effective solution, the basic causes of the
problems must be identified. It is therefore critical to have an indepth
understanding of the underlying causal factors that have
contributed to deforestation and forest degradation as a whole, in
order to attain reductions in their rates. An assessment of the drivers of deforestation and forest
degradation was carried out, in order to design and implement
measures that could slow these destructive processes. Research was
conducted in Giam Siak Kecil–Bukit Batu Biosphere Reserve
(GSKBB BR), in the Riau Province of Sumatera, Indonesia. A
biosphere reserve was selected as the study site because such reserves
aim to reconcile conservation with sustainable development. A
biosphere reserve should promote a range of local human activities,
together with development values that are in line spatially and
economically with the area conservation values, through use of a
zoning system. Moreover, GSKBB BR is an area with vast peatlands,
and is experiencing forest fires annually. Various factors were
analysed to assess the drivers of deforestation and forest degradation
in GSKBB BR; data were collected from focus group discussions
with stakeholders, key informant interviews with key stakeholders,
field observation and a literature review. Landsat satellite imagery was used to map forest-cover changes
for various periods. Analysis of landsat images, taken during the
period 2010-2014, revealed that within the non-protected area of core
zone, there was a trend towards decreasing peat swamp forest areas,
increasing land clearance, and increasing areas of community oilpalm
and rubber plantations. Fire was used for land clearing and most
of the forest fires occurred in the most populous area (the transition
area). The study found a relationship between the deforested/
degraded areas, and certain distance variables, i.e. distance from
roads, villages and the borders between the core area and the buffer
zone. The further the distance from the core area of the reserve, the
higher was the degree of deforestation and forest degradation. Research findings suggested that agricultural expansion may be
the direct cause of deforestation and forest degradation in the reserve,
whereas socio-economic factors were the underlying driver of forest
cover changes; such factors consisting of a combination of sociocultural,
infrastructural, technological, institutional (policy and governance), demographic (population pressure) and economic
(market demand) considerations. These findings indicated that local
factors/problems were the critical causes of deforestation and
degradation in GSKBB BR. This research therefore concluded that
reductions in deforestation and forest degradation in GSKBB BR
could be achieved through ‘local actor’-tailored approaches such as
community empowerment.
Abstract: Coal tar is a liquid by-product of coal pyrolysis
processes. This liquid oil mixture contains various kinds of useful
compounds such as benzoic aromatic compounds and phenolic
compounds. These compounds are widely used as raw material for
insecticides, dyes, medicines, perfumes, coloring matters, and many
others. The coal tar was collected by pyrolysis process of coal
obtained from PT Kaltim Prima Coal and Arutmin-Kalimantan. The
experiments typically occurred at the atmospheric pressure in a
laboratory furnace at temperatures ranging from 300 to 550oC with a
heating rate of 10oC/min and a holding time of 1 hour at the pyrolysis
temperature. The Gas Chromatography-Mass Spectroscopy (GC-MS)
was used to analyze the coal tar components. The obtained coal tar
has the viscosity of 3.12 cp, the density of 2.78 g/cm3, the calorific
value of 11,048.44 cal/g, and the molecular weight of 222.67. The
analysis result showed that the coal tar contained more than 78
chemical compounds such as benzene, cresol, phenol, xylene,
naphtalene, etc. The total phenolic compounds contained in coal tar
are 33.25% (PT KPC) and 17.58% (Arutmin-Kalimantan). The total
naphtalene compounds contained in coal tar is 14.15% (PT KPC) and
17.13% (Arutmin-Kalimantan).
Abstract: Liquid-Liquid Equilibrium (LLE) data are measured
for the ternary mixtures of water + 1-butanol + butyl acetate and
quaternary mixtures of water + 1-butanol + butyl acetate + glycerol at
atmospheric pressure at 313.15 K. In addition, isothermal
vapor–liquid–liquid equilibrium (VLLE) data are determined
experimentally at 333.15 K. The region of heterogeneity is found to
increase as the hydrophilic agent (glycerol) is introduced into the
aqueous mixtures. The experimental data are correlated with the
NRTL model. The predicted results from the solution model with the
model parameters determined from the constituent binaries are also
compared with the experimental values.
Abstract: This paper presents the results obtained by numerical
simulation using the software ANSYS CFX-CFD for the air
pollutants dispersion in the atmosphere coming from the evacuation
of combustion gases resulting from the fuel combustion in an electric
thermal power plant. The model uses the Navier-Stokes equation to
simulate the dispersion of pollutants in the atmosphere. It is
considered as important factors in elaboration of simulation the
atmospheric conditions (pressure, temperature, wind speed, wind
direction), the exhaust velocity of the combustion gases, chimney
height and the obstacles (buildings). Using the air quality monitoring
stations it is measured the concentrations of main pollutants (SO2,
NOx and PM). The pollutants were monitored over a period of 3
months, after that the average concentration are calculated, which is
used by the software. The concentrations are: 8.915 μg/m3 (NOx),
9.587 μg/m3 (SO2) and 42 μg/m3 (PM). A comparison of test data
with simulation results demonstrated that CFX was able to describe
the dispersion of the pollutant as well the concentration of this
pollutants in the atmosphere.