Abstract: Since the pioneering work of Zadeh, fuzzy set theory has been applied to a myriad of areas. Song and Chissom introduced the concept of fuzzy time series and applied some methods to the enrollments of the University of Alabama. In recent years, a number of techniques have been proposed for forecasting based on fuzzy set theory methods. These methods have either used enrollment numbers or differences of enrollments as the universe of discourse. We propose using the year to year percentage change as the universe of discourse. In this communication, the approach of Jilani, Burney, and Ardil is modified by using the year to year percentage change as the universe of discourse. We use enrollment figures for the University of Alabama to illustrate our proposed method. The proposed method results in better forecasting accuracy than existing models.
Abstract: The greenhouse effect and limitations on carbon
dioxide emissions concern engine maker and the future of the
internal combustion engines should go toward substantially and
improved thermal efficiency engine. Homogeneous charge
compression ignition (HCCI) is an alternative high-efficiency
technology for combustion engines to reduce exhaust emissions and
fuel consumption. However, there are still tough challenges in the
successful operation of HCCI engines, such as controlling the
combustion phasing, extending the operating range, and high
unburned hydrocarbon and CO emissions. HCCI and the exploitation
of ethanol as an alternative fuel is one way to explore new frontiers
of internal combustion engines with an eye towards maintaining its
sustainability. This study was done to extend database knowledge
about HCCI with ethanol a fuel.
Abstract: This paper presents the experimental results of a
single cylinder Enfield engine using an electronically controlled fuel
injection system which was developed to carry out exhaustive tests
using neat CNG, and mixtures of hydrogen in compressed natural gas
(HCNG) as 0, 5, 10, 15 and 20% by energy. Experiments were
performed at 2000 and 2400 rpm with wide open throttle and varying
the equivalence ratio. Hydrogen which has fast burning rate, when
added to compressed natural gas, enhances its flame propagation rate.
The emissions of HC, CO, decreased with increasing percentage of
hydrogen but NOx was found to increase. The results indicated a
marked improvement in the brake thermal efficiency with the
increase in percentage of hydrogen added. The improved thermal
efficiency was clearly observed to be more in lean region as
compared to rich region. This study is expected to reduce vehicular
emissions along with increase in thermal efficiency and thus help in
reduction of further environmental degradation.
Abstract: Solid fuel transient burning behavior under oxidizer
gas flow is numerically investigated. It is done using analysis of the
regression rate responses to the imposed sudden and oscillatory
variation at inflow properties. The conjugate problem is considered
by simultaneous solution of flow and solid phase governing
equations to compute the fuel regression rate. The advection
upstream splitting method is used as flow computational scheme in
finite volume method. The ignition phase is completely simulated to
obtain the exact initial condition for response analysis. The results
show that the transient burning effects which lead to the combustion
instabilities and intermittent extinctions could be observed in solid
fuels as the solid propellants.
Abstract: The mixture formation prior to the ignition process
plays as a key element in the diesel combustion. Parametric studies of
mixture formation and ignition process in various injection parameter
has received considerable attention in potential for reducing
emissions. Purpose of this study is to clarify the effects of injection
pressure on mixture formation and ignition especially during ignition
delay period, which have to be significantly influences throughout the
combustion process and exhaust emissions. This study investigated
the effects of injection pressure on diesel combustion fundamentally
using rapid compression machine. The detail behavior of mixture
formation during ignition delay period was investigated using the
schlieren photography system with a high speed camera. This method
can capture spray evaporation, spray interference, mixture formation
and flame development clearly with real images. Ignition process and
flame development were investigated by direct photography method
using a light sensitive high-speed color digital video camera. The
injection pressure and air motion are important variable that strongly
affect to the fuel evaporation, endothermic and prolysis process
during ignition delay. An increased injection pressure makes spray tip
penetration longer and promotes a greater amount of fuel-air mixing
occurs during ignition delay. A greater quantity of fuel prepared
during ignition delay period thus predominantly promotes more rapid
heat release.
Abstract: Combustion of sprays is of technological importance, but its flame behavior is not fully understood. Furthermore, the multiplicity of dependent variables such as pressure, temperature, equivalence ratio, and droplet sizes complicates the study of spray combustion. Fundamental study on the influence of the presence of liquid droplets has revealed that laminar flames within aerosol mixtures more readily become unstable than for gaseous ones and this increases the practical burning rate. However, fundamental studies on turbulent flames of aerosol mixtures are limited particularly those under near mono-dispersed droplet conditions. In the present work, centrally ignited expanding flames at near atmospheric pressures are employed to quantify the burning rates in gaseous and aerosol flames. Iso-octane-air aerosols are generated by expansion of the gaseous pre-mixture to produce a homogeneously distributed suspension of fuel droplets. The effects of the presence of droplets and turbulence velocity in relation to the burning rates of the flame are also investigated.
Abstract: Large scale climate signals and their teleconnections can influence hydro-meteorological variables on a local scale. Several extreme flow and timing measures, including high flow and low flow measures, from 62 hydrometric stations in Canada are investigated to detect possible linkages with several large scale climate indices. The streamflow data used in this study are derived from the Canadian Reference Hydrometric Basin Network and are characterized by relatively pristine and stable land-use conditions with a minimum of 40 years of record. A composite analysis approach was used to identify linkages between extreme flow and timing measures and climate indices. The approach involves determining the 10 highest and 10 lowest values of various climate indices from the data record. Extreme flow and timing measures for each station were examined for the years associated with the 10 largest values and the years associated with the 10 smallest values. In each case, a re-sampling approach was applied to determine if the 10 values of extreme flow measures differed significantly from the series mean. Results indicate that several stations are impacted by the large scale climate indices considered in this study. The results allow the determination of any relationship between stations that exhibit a statistically significant trend and stations for which the extreme measures exhibit a linkage with the climate indices.
Abstract: Our Medicine-oriented research is based on a medical
data set of real patients. It is a security problem to share
patient private data with peoples other than clinician or hospital
staff. We have to remove person identification information
from medical data. The medical data without private data
are available after a de-identification process for any research
purposes. In this paper, we introduce an universal automatic
rule-based de-identification application to do all this stuff on an
heterogeneous medical data. A patient private identification is
replaced by an unique identification number, even in burnedin
annotation in pixel data. The identical identification is used
for all patient medical data, so it keeps relationships in a data.
Hospital can take an advantage of a research feedback based
on results.
Abstract: In this paper a polymer electrolyte membrane (PEM)
fuel cell power system including burner, steam reformer, heat
exchanger and water heater has been considered to meet the
electrical, heating, cooling and domestic hot water loads of
residential building which in Tehran. The system uses natural gas as
fuel and works in CHP mode. Design and operating conditions of a
PEM fuel cell system is considered in this study. The energy
requirements of residential building and the number of fuel cell
stacks to meet them have been estimated. The method involved
exergy analysis and entropy generation thorough the months of the
year. Results show that all the energy needs of the building can be
met with 12 fuel cell stacks at a nominal capacity of 8.5 kW. Exergy
analysis of the CHP system shows that the increase in the ambient air
temperature from 1oC to 40oC, will have an increase of entropy
generation by 5.73%.Maximum entropy generates for 15 hour in 15th
of June and 15th of July is estimated to amount at 12624 (kW/K).
Entropy generation of this system through a year is estimated to
amount to 1004.54 GJ/k.year.
Abstract: Present study focuses on studying the oscillatory
behavior of jet diffusion flames. At a particular jet exit velocity, the
flames are seen to exhibit natural flickering. Initially the flickering
process is not continuous. In this transition region as well as in the
continuous flickering regime, the flickering displays multiple
frequency oscillations. The response of the flame to the exit velocity
profile of the burner is also studied using three types of burners. The
entire range of natural flickering is investigated by capturing high
speed digital images and processing them using a MATLAB code.
Abstract: Smoke from domestic wood burning has been
identified as a major contributor to air pollution, motivating detailed
emission measurements under controlled conditions. A series of
experiments was performed to characterise the emissions from wood
combustion in a fireplace and in a woodstove of two common species
of trees grown in Spain: Pyrenean oak (Quercus pyrenaica) and
black poplar (Populus nigra). Volatile organic compounds (VOCs) in
the exhaust emissions were collected in Tedlar bags, re-sampled in
sorbent tubes and analysed by thermal desorption-gas
chromatography-flame ionisation detection. Pyrenean oak presented
substantially higher emissions in the woodstove than in the fireplace,
for the majority of compounds. The opposite was observed for
poplar. Among the 45 identified species, benzene and benzenerelated
compounds represent the most abundant group, followed by
oxygenated VOCs and aliphatics. Emission factors obtained in this
study are generally of the same order than those reported for
residential experiments in the USA.
Abstract: This paper presents a compact thermoelectric power generator system based on temperature difference across the element. The system can transfer the burning heat energy to electric energy directly. The proposed system has a thermoelectric generator and a power control box. In the generator, there are 4 thermoelectric modules (TEMs), each of which uses 2 thermoelectric chips (TEs) and 2 cold sinks, 1 thermal absorber, and 1 thermal conduction flat board. In the power control box, there are 1 storing energy device, 1 converter, and 1 inverter. The total net generating power is about 11W. This system uses commercial portable gas stoves or burns timber or the coal as the heat source, which is easily obtained. It adopts solid-state thermoelectric chips as heat inverter parts. The system has the advantages of being light-weight, quite, and mobile, requiring no maintenance, and havng easily-supplied heat source. The system can be used a as long as burning is allowed. This system works well for highly-mobilized outdoors situations by providing a power for illumination, entertainment equipment or the wireless equipment at refuge. Under heavy storms such as typhoon, when the solar panels become ineffective and the wind-powered machines malfunction, the thermoelectric power generator can continue providing the vital power.
Abstract: Transesterified vegetable oils (biodiesel) are promising alternative fuel for diesel engines. Used vegetable oils are disposed from restaurants in large quantities. But higher viscosity restricts their direct use in diesel engines. In this study, used cooking oil was dehydrated and then transesterified using an alkaline catalyst. The combustion, performance and emission characteristics of Used Cooking oil Methyl Ester (UCME) and its blends with diesel oil are analysed in a direct injection C.I. engine. The fuel properties and the combustion characteristics of UCME are found to be similar to those of diesel. A minor decrease in thermal efficiency with significant improvement in reduction of particulates, carbon monoxide and unburnt hydrocarbons is observed compared to diesel. The use of transesterified used cooking oil and its blends as fuel for diesel engines will reduce dependence on fossil fuels and also decrease considerably the environmental pollution.
Abstract: Understanding of how and where NOx formation
occurs in industrial burner is very important for efficient and clean
operation of utility burners. Also the importance of this problem is
mainly due to its relation to the pollutants produced by more burners
used widely of gas turbine in thermal power plants and glass and steel
industry.
In this article, a numerical model of an industrial burner operating
in MILD combustion is validated with experimental data.. Then
influence of air flow rate and air temperature on combustor
temperature profiles and NOX product are investigated. In order to
modification this study reports on the effects of fuel and air dilution
(with inert gases H2O, CO2, N2), and also influence of lean-premixed
of fuel, on the temperature profiles and NOX emission.
Conservation equations of mass, momentum and energy, and
transport equations of species concentrations, turbulence, combustion
and radiation modeling in addition to NO modeling equations were
solved together to present temperature and NO distribution inside the
burner.
The results shows that dilution, cause to a reduction in value of
temperature and NOX emission, and suppresses any flame
propagation inside the furnace and made the flame inside the furnace
invisible. Dilution with H2O rather than N2 and CO2 decreases further
the value of the NOX. Also with raise of lean-premix level, local
temperature of burner and the value of NOX product are decreases
because of premixing prevents local “hot spots" within the combustor
volume that can lead to significant NOx formation. Also leanpremixing
of fuel with air cause to amount of air in reaction zone is
reach more than amount that supplied as is actually needed to burn
the fuel and this act lead to limiting NOx formation
Abstract: The purpose of our study was to compare spontaneous
re-epithelisation characteristics versus assisted re-epithelisation. In
order to assess re-epithelisation of the injured skin, we have imagined
and designed a burn wound model on Wistar rat skin. Our aim was to
create standardised, easy reproducible and quantifiable skin lesions
involving entire epidermis and superficial dermis. We then have
applied the above mentioned therapeutic strategies to compare
regeneration of epidermis and dermis, local and systemic parameter
changes in different conditions. We have enhanced the reepithelisation
process under a moist atmosphere of a polyurethane
wound dress modified with helium non-thermal plasma, and with the
aid of direct cold-plasma treatment respectively. We have followed
systemic parameters change: hematologic and biochemical
parameters, and local features: oxidative stress markers and histology
of skin in the above mentioned conditions. Re-epithelisation is just a
part of the skin regeneration process, which recruits cellular
components, with the aid of epidermal and dermal interaction via
signal molecules.
Abstract: The purpose of this paper is to investigate the
durability of cement mortar in presence of Rice Husk Ash (RHA).
The strength and durability of mortar with different replacement
level (0%, 10%, 15%, 20%, 25% and 30%) of Ordinary Portland
Cement (OPC) by RHA is investigated here. RHA was
manufactured from an uncontrolled burning process. Test samples
were prepared with river sand of FM 2.73. Samples were kept in
controlled environment up to test time. The results show that
addition of RHA was shown better results for 20% replacement
level than OPC at 90 days. In durability test all samples passed for
20 cycles except 25% and 30% replacement level.
Abstract: Coal fly ash (CFA) generated by coal-based thermal
power plants is mainly composed of quartz, mullite, and unburned
carbon. In this study, the effect of unburned carbon on CFA toward
its adsorption capacity was investigated. CFA with various carbon
content was obtained by refluxing it with sulfuric acid having various
concentration at various temperature and reflux time, by heating at
400-800°C, and by sieving into 100-mesh in particle size. To
evaluate the effect of unburned carbon on CFA toward its adsorption
capacity, adsorption of methyl violet solution with treated CFA was
carried out. The research shows that unburned carbon leads to
adsorption capacity decrease. The highest adsorption capacity of
treated CFA was found 5.73 x 10-4mol.g-1.
Abstract: Plastic waste is a big issue in Thailand, but the amount of recycled plastic in Thailand is still low due to the high investment and operating cost. Hence, the rest of plastic waste are burnt to destroy or sent to the landfills. In order to be financial viable, an effective reverse logistics infrastructure is required to support the product recovery activities. However, there is a conflict between reducing the cost and raising environmental protection level. The purpose of this study is to build a goal programming (GP) so that it can be used to help analyze the proper planning of the Thailand-s plastic recycling system that involves multiple objectives. This study considers three objectives; reducing total cost, increasing the amount of plastic recovery, and raising the desired plastic materials in recycling process. The results from two priority structures show that it is necessary to raise the total cost budget in order to achieve targets on amount of recycled plastic and desired plastic materials.
Abstract: The objective of this work is to investigate the
turbulent reacting flow in a three dimensional combustor with
emphasis on the effect of inlet swirl flow through a numerical
simulation. Flow field is analyzed using the SIMPLE method which is
known as stable as well as accurate in the combustion modeling, and
the finite volume method is adopted in solving the radiative transfer
equation. In this work, the thermal and flow characteristics in a three
dimensional combustor by changing parameters such as equivalence
ratio and inlet swirl angle have investigated. As the equivalence ratio
increases, which means that more fuel is supplied due to a larger inlet
fuel velocity, the flame temperature increases and the location of
maximum temperature has moved towards downstream. In the mean
while, the existence of inlet swirl velocity makes the fuel and
combustion air more completely mixed and burnt in short distance.
Therefore, the locations of the maximum reaction rate and temperature
were shifted to forward direction compared with the case of no swirl.
Abstract: Work is focused to the study of unburned carbon in
ash from coal (and wastes) combustion in 8 combustion tests at 3
fluidised-bed power station, at co-combustion of coal and wastes
(also at fluidized bed) and at bench-scale unit simulating coal
combustion in small domestic furnaces. The attention is paid to
unburned carbon contents in bottom ashes and fly ashes at these 8
combustion tests and to morphology of unburned carbons. Specific
surface area of coals, unburned carbons and ashes and the relation of
specific surface area of unburned carbon and the content of volatile
combustibles in coal were studied as well.