Abstract: The agriculture lignocellulosic by-products are receiving increased attention, namely in the search for filter materials that retain contaminants from water. These by-products, specifically almond and hazelnut shells are abundant in Portugal once almond and hazelnuts production is a local important activity. Hazelnut and almond shells have as main constituents lignin, cellulose and hemicelluloses, water soluble extractives and tannins. Along the adsorption of heavy metals from contaminated waters, water soluble compounds can leach from shells and have a negative impact in the environment. Usually, the chemical characterization of treated water by itself may not show environmental impact caused by the discharges when parameters obey to legal quality standards for water. Only biological systems can detect the toxic effects of the water constituents. Therefore, the evaluation of toxicity by biological tests is very important when deciding the suitability for safe water discharge or for irrigation applications.
The main purpose of the present work was to assess the potential impacts of waters after been treated for heavy metal removal by hazelnut and almond shells adsorption systems, with short term acute toxicity tests.
To conduct the study, water at pH 6 with 25 mg.L-1 of lead, was treated with 10 g of shell per litre of wastewater, for 24 hours. This procedure was followed for each bark. Afterwards the water was collected for toxicological assays; namely bacterial resistance, seed germination, Lemna minor L. test and plant grow. The effect in isolated bacteria strains was determined by disc diffusion method and the germination index of seed was evaluated using lettuce, with temperature and humidity germination control for 7 days. For aquatic higher organism, Lemnas were used with 4 days contact time with shell solutions, in controlled light and temperature. For terrestrial higher plants, biomass production was evaluated after 14 days of tomato germination had occurred in soil, with controlled humidity, light and temperature.
Toxicity tests of water treated with shells revealed in some extent effects in the tested organisms, with the test assays showing a close behaviour as the control, leading to the conclusion that its further utilization may not be considered to create a serious risk to the environment.
Abstract: In this study, effects of EGR on CO and HC emissions
of a dual fuel HCCI-DI engine are investigated. Tests were
conducted on a single-cylinder variable compression ratio (VCR)
diesel engine with compression ratio of 17.5. Premixed gasoline is
provided by a carburetor connected to intake manifold and equipped
with a screw to adjust premixed air-fuel ratio, and diesel fuel is
injected directly into the cylinder through an injector at pressure of
250 bars. A heater placed at inlet manifold is used to control the
intake charge temperature. Optimal intake charge temperature was
110-115ºC due to better formation of a homogeneous mixture
causing HCCI combustion. Timing of diesel fuel injection has a great
effect on stratification of in-cylinder charge in HCCI combustion.
Experiments indicated 35 BTDC as the optimum injection timing.
Coolant temperature was maintained 50ºC during the tests. Results
show that increasing engine speed at a constant EGR rate leads to
increase in CO and UHC emissions due to the incomplete
combustion caused by shorter combustion duration and less
homogeneous mixture. Results also show that increasing EGR
reduces the amount of oxygen and leads to incomplete combustion
and therefore increases CO emission due to lower combustion
temperature. HC emission also increases as a result of lower
combustion temperatures.
Abstract: The objective from this paper is to design a solar
thermal engine for space vehicles orbital control and electricity
generation. A computational model is developed for the prediction of
the solar thermal engine performance for different design parameters and conditions in order to enhance the engine efficiency. The engine is divided into two main subsystems. First, the concentrator dish
which receives solar energy from the sun and reflects them to the
cavity receiver. The second one is the cavity receiver which receives
the heat flux reflected from the concentrator and transfers heat to the
fluid passing over. Other subsystems depend on the application required from the engine. For thrust application, a nozzle is
introduced to the system for the fluid to expand and produce thrust.
Hydrogen is preferred as a working fluid in the thruster application.
Results model developed is used to determine the thrust for a
concentrator dish 4 meters in diameter (provides 10 kW of energy),
focusing solar energy to a 10 cm aperture diameter cavity receiver.
The cavity receiver outer length is 50 cm and the internal cavity is 47
cm in length. The suggested design material of the internal cavity is
tungsten to withstand high temperature. The thermal model and
analysis shows that the hydrogen temperature at the plenum reaches
2000oK after about 250 seconds for hot start operation for a flow rate
of 0.1 g/sec.Using solar thermal engine as an electricity generation
device on earth is also discussed. In this case a compressor and
turbine are used to convert the heat gained by the working fluid (air)
into mechanical power. This mechanical power can be converted into
electrical power by using a generator.
Abstract: Reinforced Concrete (RC) structures strengthened
with fiber reinforced polymer (FRP) lack in thermal resistance under
elevated temperatures in the event of fire. This phenomenon led to
the lining of strengthened concrete with thin high performance
cementitious composites (THPCC) to protect the substrate against
elevated temperature. Elevated temperature effects on THPCC, based
on different cementitious materials have been studied in the past but
high-alumina cement (HAC)-based THPCC have not been well
characterized. This research study will focus on the THPCC based on
HAC replaced by 60%, 70%, 80% and 85% of ground granulated
blast furnace slag (GGBS). Samples were evaluated by the
measurement of their mechanical strength (28 & 56 days of curing)
after exposed to 400°C, 600°C and 28°C of room temperature for
comparison and corroborated by their microstructure study. Results
showed that among all mixtures, the mix containing only HAC
showed the highest compressive strength after exposed to 600°C as
compared to other mixtures. However, the tensile strength of THPCC
made of HAC and 60% GGBS content was comparable to the
THPCC with HAC only after exposed to 600°C. Field emission
scanning electron microscopy (FESEM) images of THPCC
accompanying Energy Dispersive X-ray (EDX) microanalysis
revealed that the microstructure deteriorated considerably after
exposure to elevated temperatures which led to the decrease in
mechanical strength.
Abstract: New lead-free ferroelectric relaxor ceramics were
prepared by conventional solid-state synthesis in the BaTiO3-Bi2O3-
Y2O3 systems. Some of these ceramics present a ferroelectric relaxor
with transition temperature close to room temperature. These new
materials are very interesting for applications and can replace leadbased
ceramic to prevent the toxic pollutions during the preparation
state. In the other hand, the energy band diagram shows the
potentiality of these compounds for the solar energy conversion.
Thus, some compositions have been tested successfully for H2
production upon visible light. The best activity occurs in alkaline
media with a rate evolution of about 0.15 mL g-1 mn-1 and a quantum
yield of 1% under polychromatic light.
Abstract: The plastic flow of metal in the extrusion process is
an important factor in controlling the mechanical properties of the
extruded products. It is, however, difficult to predict the metal flow
in three dimensional extrusions of sections due to the involvement of
re-entrant corners. The present study is to find an upper bound
solution for the extrusion of triangular sectioned through taper dies
from round sectioned billet. A discontinuous kinematically
admissible velocity field (KAVF) is proposed. From the proposed
KAVF, the upper bound solution on non-dimensional extrusion
pressure is determined with respect to the chosen process parameters.
The theoretical results are compared with experimental results to
check the validity of the proposed velocity field. An extrusion setup
is designed and fabricated for the said purpose, and all extrusions are
carried out using circular billets. Experiments are carried out with
commercially available lead at room temperature.
Abstract: In this paper, the feasibility study of using a hybrid
system of ground heat exchangers (GHE) and direct evaporative
cooling system in arid weather condition has been performed. The
model is applied for Yazd and Kerman, two cities with arid weather
condition in Iran. The system composed of three sections: Ground-
Coupled-Circuit (GCC), Direct Evaporative Cooler (DEC) and
Cooling Coil Unite (CCU). The GCC provides the necessary precooling
for DEC. The GCC includes four vertical GHE which are
designed in series configuration. Simulation results show that
hybridization of GCC and DEC could provide comfort condition
whereas DEC alone did not. Based on the results the cooling
effectiveness of a hybrid system is more than unity. Thus, this novel
hybrid system could decrease the air temperature below the ambient
wet-bulb temperature. This environmentally clean and energy
efficient system can be considered as an alternative to the mechanical
vapor compression systems.
Abstract: During the last decade ultrafine grained (UFG) and nano-structured (NS) materials have experienced a rapid development. In this research work finite element analysis has been carried out to investigate the plastic strain distribution in equal channel angular process (ECAP). The magnitudes of Standard deviation (S. D.) and inhomogeneity index (Ci) were compared for different ECAP passes. Verification of a three-dimensional finite element model was performed with experimental tests. Finally the mechanical property including impact energy of ultrafine grained pure commercially pure Aluminum produced by severe plastic deformation method has been examined. For this aim, equal channel angular pressing die with the channel angle, outer corner angle and channel diameter of 90°, 20° and 20mm had been designed and manufactured. Commercial pure Aluminum billets were ECAPed up to four passes by route BC at the ambient temperature. The results indicated that there is a great improvement at the hardness measurement, yield strength and ultimate tensile strength after ECAP process. It is found that the magnitudes of HV reach 67HV from 21HV after the final stage of process. Also, about 330% and 285% enhancement at the YS and UTS values have been obtained after the fourth pass as compared to the as-received conditions, respectively. On the other hand, the elongation to failure and impact energy have been reduced by 23% and 50% after imposing four passes of ECAP process, respectively.
Abstract: Turbulent heat transfer to fluid flow through channel with triangular ribs of different angles are presented in this paper. Ansys 14 ICEM and Ansys 14 Fluent are used for meshing process and solving Navier stokes equations respectively. In this investigation three angles of triangular ribs with the range of Reynolds number varied from 20000 to 60000 at constant surface temperature are considered. The results show that the Nusselt number increases with the increase of Reynolds number for all cases at constant surface temperature. According to the profile of local Nusselt number on ribs walled of channel, the peak is at the midpoint between the two ribs. The maximum value of average Nusselt number is obtained for triangular ribs of angel 60°and at Reynolds number of 60000 compared to the Nusselt number for the ribs of angel 90° and 45° and at same Reynolds number. The recirculation regions generated by the ribs corresponding to the velocity streamline show the largest recirculation region at triangular ribs of angle 60° which also provides the highest enhancement of heat transfer.
Abstract: Technology of thin film deposition is of interest in
many engineering fields, from electronic manufacturing to corrosion
protective coating. A typical deposition process, like that developed
at the University of Eindhoven, considers the deposition of a thin,
amorphous film of C:H or of Si:H on the substrate, using the
Expanding Thermal arc Plasma technique. In this paper a computing
procedure is proposed to simulate the flow field in a deposition
chamber similar to that at the University of Eindhoven and a
sensitivity analysis is carried out in terms of: precursor mass flow
rate, electrical power, supplied to the torch and fluid-dynamic
characteristics of the plasma jet, using different nozzles. To this
purpose a deposition chamber similar in shape, dimensions and
operating parameters to the above mentioned chamber is considered.
Furthermore, a method is proposed for a very preliminary evaluation
of the film thickness distribution on the substrate. The computing
procedure relies on two codes working in tandem; the output from
the first code is the input to the second one. The first code simulates
the flow field in the torch, where Argon is ionized according to the
Saha-s equation, and in the nozzle. The second code simulates the
flow field in the chamber. Due to high rarefaction level, this is a
(commercial) Direct Simulation Monte Carlo code. Gas is a mixture
of 21 chemical species and 24 chemical reactions from Argon plasma
and Acetylene are implemented in both codes. The effects of the
above mentioned operating parameters are evaluated and discussed
by 2-D maps and profiles of some important thermo-fluid-dynamic
parameters, as per Mach number, velocity and temperature. Intensity,
position and extension of the shock wave are evaluated and the
influence of the above mentioned test conditions on the film
thickness and uniformity of distribution are also evaluated.
Abstract: The abundance and availability of rice husk, an agricultural waste, make them as a good source for precursor of activated carbon. In this work, rice husk-based activated carbons were prepared via base treated chemical activation process prior the carbonization process. The effect of carbonization temperatures (400, 600 and 800oC) on their pore structure was evaluated through morphology analysis using scanning electron microscope (SEM). Sample carbonized at 800oC showed better evolution and development of pores as compared to those carbonized at 400 and 600oC. The potential of rice husk-based activated carbon as an alternative adsorbent was investigated for the removal of Ni(II), Zn(II) and Pb(II) from single metal aqueous solution. The adsorption studies using rice husk-based activated carbon as an adsorbent were carried out as a function of contact time at room temperature and the metal ions were analyzed using atomic absorption spectrophotometer (AAS). The ability to remove metal ion from single metal aqueous solution was found to be improved with the increasing of carbonization temperature. Among the three metal ions tested, Pb(II) ion gave the highest adsorption on rice husk-based activated carbon. The results obtained indicate the potential to utilize rice husk as a promising precursor for the preparation of activated carbon for removal of heavy metals.
Abstract: The aim of this study was to extract sugar from
sugarcane using high electric field pulse (HELP) as a non-thermal cell permeabilization method. The result of this study showed that it
is possible to permeablize sugar cane cells using HELP at very short times (less than 10 sec.) and at room temperature. Increasing the field strength (from 0.5kV/cm to 2kV/cm) and pulse number (1 to 12) led to increasing the permeabilization of sugar cane cells. The energy
consumption during HELP treatment of sugar cane (2.4 kJ/kg) was about 100 times less compared to thermal cell disintegration at 85
Abstract: Heating systems are a necessity for regions which
brace extreme cold weather throughout the year. To maintain a comfortable temperature inside a given place, heating systems
making use of- Hydronic boilers- are used. The principle of a single
pipe system serves as a base for their working. It is mandatory for these heating systems to control the room temperature, thus
maintaining a warm environment. In this paper, the concept of regulation of the room temperature over a wide range is established
by using an Adaptive Fuzzy Controller (AFC). This fuzzy controller automatically detects the changes in the outside temperatures and
correspondingly maintains the inside temperature to a palatial value. Two separate AFC's are put to use to carry out this function: one to
determine the quantity of heat needed to reach the prospective temperature required and to set the desired temperature; the other to control the position of the valve, which is directly proportional to the
error between the present room temperature and the user desired temperature. The fuzzy logic controls the position of the valve as per
the requirement of the heat. The amount by which the valve opens or closes is controlled by 5 knob positions, which vary from minimum to maximum, thereby regulating the amount of heat flowing through the valve. For the given test system data, different de-fuzzifier
methods have been implemented and the results are compared. In order to validate the effectiveness of the proposed approach, a fuzzy controller has been designed by obtaining a test data from a real time
system. The simulations are performed in MATLAB and are verified with standard system data. The proposed approach can be implemented for real time applications.
Abstract: Method of determining of moisture diffusivity on two types of autoclaved aerated concretes with different bulk density is represented in the paper. On the specimens were measured one dimensional water transport only on liquid phase. Ever evaluation was done from moisture profiles measured in specific times by capacitance moisture meter. All values from capacitance meter were recalculated to moisture content by mass. Moisture diffusivity was determined in dependence on both moisture and temperature. The experiment temperatures were set at values 55, 65, 75 and 85°C.
Abstract: Aggregation behavior of sodium salicylate and sodium cumene sulfonate was studied in aqueous solution at different temperature. Specific conductivity and relative viscosity were measured at different temperature to find minimum hydrotropic concentration. The thermodynamic parameters (free energy, enthalpy and entropy) were evaluated in the temperature range of 30°C-70°C. The free energy decreased with increase in temperature. The aggregation was found to be exothermic in nature and favored by positive value of entropy.
Abstract: Photoselective plastic films with thermic properties
are now available so that greenhouses clad with such plastics exhibit
a higher degree of “Greenhouse Effect” with a consequent increase in
night time temperature. In this study, we investigate the potential
benefits of a range of thermic plastic films used as greenhouse cover
materials on the vegetative and reproductive growth and development
of Iceberg lettuce (Lactuca sativa L). Transplants were grown under
thermic films and destructively harvested 4, 5, and 6 weeks after
transplanting. Thermic films can increase night temperatures up to 2
⁰C reducing the wide fluctuation in greenhouse temperature during
winter compared to the standard commercial film and consequently
increased the yield (leaf number, fresh weight, and dry weight) of
lettuce plants. Lettuce plants grown under Clear film respond to cold
stress by the accumulation of secondary products (phenolics, and
flavonoids).
Abstract: Dengue fever is prevalent in Malaysia with numerous
cases including mortality recorded over the years. Public education
on the prevention of the desease through various means has been
carried out besides the enforcement of legal means to eradicate
Aedes mosquitoes, the dengue vector breeding ground. Hence, other
means need to be explored, such as predicting the seasonal peak
period of the dengue outbreak and identifying related climate factors
contributing to the increase in the number of mosquitoes. Simulation
model can be employed for this purpose. In this study, we created a
simulation of system dynamic to predict the spread of dengue
outbreak in Hulu Langat, Selangor Malaysia. The prototype was
developed using STELLA 9.1.2 software. The main data input are
rainfall, temperature and denggue cases. Data analysis from the graph
showed that denggue cases can be predicted accurately using these
two main variables- rainfall and temperature. However, the model
will be further tested over a longer time period to ensure its
accuracy, reliability and efficiency as a prediction tool for dengue
outbreak.
Abstract: One of the most important requirements for the
operation and planning activities of an electrical utility is the
prediction of load for the next hour to several days out, known as
short term load forecasting. This paper presents the development of
an artificial neural network based short-term load forecasting model.
The model can forecast daily load profiles with a load time of one
day for next 24 hours. In this method can divide days of year with
using average temperature. Groups make according linearity rate of
curve. Ultimate forecast for each group obtain with considering
weekday and weekend. This paper investigates effects of temperature
and humidity on consuming curve. For forecasting load curve of
holidays at first forecast pick and valley and then the neural network
forecast is re-shaped with the new data. The ANN-based load models
are trained using hourly historical. Load data and daily historical
max/min temperature and humidity data. The results of testing the
system on data from Yazd utility are reported.
Abstract: Various solar energy technologies exist and they have
different application techniques in the generation of electrical power.
The widespread use of photovoltaic (PV) modules in such
technologies has been limited by relatively high costs and low
efficiencies. The efficiency of PV panels decreases as the operating
temperatures increase. This is due to the affect of solar intensity and
ambient temperature. In this work, Computational Fluid Dynamics
(CFD) was used to model the heat transfer from a standard PV panel
and thus determine the rate of dissipation of heat. To accurately
model the specific climatic conditions of the United Arab Emirates
(UAE), a case study of a new build green building in Dubai was
used. A finned heat pipe arrangement is proposed and analyzed to
determine the improved heat dissipation and thus improved
performance efficiency of the PV panel. A prototype of the
arrangement is built for experimental testing to validate the CFD
modeling and proof of concept.
Abstract: Nowadays, the focus on renewable energy and alternative fuels has increased due to increasing oil prices, environment pollution, and also concern on preserving the nature. Biodiesel has been known as an attractive alternative fuel although biodiesel produced from edible oil is very expensive than conventional diesel. Therefore, the uses of biodiesel produced from non-edible oils are much better option. Currently Jatropha biodiesel (JBD) is receiving attention as an alternative fuel for diesel engine. Biodiesel is non-toxic, biodegradable, high lubricant ability, highly renewable, and its use therefore produces real reduction in petroleum consumption and carbon dioxide (CO2) emissions. Although biodiesel has many advantages, but it still has several properties need to improve, such as lower calorific value, lower effective engine power, higher emission of nitrogen oxides (NOX) and greater sensitivity to low temperature. Exhaust gas recirculation (EGR) is effective technique to reduce NOX emission from diesel engines because it enables lower flame temperature and oxygen concentration in the combustion chamber. Some studies succeeded to reduce the NOX emission from biodiesel by EGR but they observed increasing soot emission. The aim of this study was to investigate the engine performance and soot emission by using blended Jatropha biodiesel with different EGR rates. A CI engine that is water-cooled, turbocharged, using indirect injection system was used for the investigation. Soot emission, NOX, CO2, carbon monoxide (CO) were recorded and various engine performance parameters were also evaluated.