Abstract: Air infiltration in mass scale industrial applications of
bio char production is inevitable. The presence of oxygen during the
carbonization process is detrimental to the production of biochar yield
and properties. The experiment was carried out on several wood
species in a fixed-bed pyrolyser under various fractions of oxygen
ranging from 0% to 11% by varying nitrogen and oxygen composition
in the pyrolysing gas mixtures at desired compositions. The bed
temperature and holding time were also varied. Process optimization
was carried out by Response Surface Methodology (RSM) by
employing Central Composite Design (CCD) using Design Expert 6.0
Software. The effect of oxygen ratio and holding time on biochar yield
within the range studied were statistically significant. From the
analysis result, optimum condition of 15.2% biochar yield of
mangrove wood was predicted at pyrolysis temperature of 403 oC,
oxygen percentage of 2.3% and holding time of two hours. This
prediction agreed well with the experiment finding of 15.1% biochar
yield.
Abstract: In this paper, the effects of radiation, chemical
reaction and double dispersion on mixed convection heat and mass
transfer along a semi vertical plate are considered. The plate is
embedded in a Newtonian fluid saturated non - Darcy (Forchheimer
flow model) porous medium. The Forchheimer extension and first
order chemical reaction are considered in the flow equations. The
governing sets of partial differential equations are nondimensionalized
and reduced to a set of ordinary differential
equations which are then solved numerically by Fourth order Runge–
Kutta method. Numerical results for the detail of the velocity,
temperature, and concentration profiles as well as heat transfer rates
(Nusselt number) and mass transfer rates (Sherwood number) against
various parameters are presented in graphs. The obtained results are
checked against previously published work for special cases of the
problem and are found to be in good agreement.
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: This study addresses the effect of impurities on the
crystallization of Na2CO3 produced within a strategy for capturing
CO2 from flue gases by alkaline absorption. A novel technology -
membrane assisted crystallization - is proposed for Na2CO3
crystallization from mother liquors containing impurities. High purity
of Na2CO3•10H2O crystals was obtained without impacting the
performance of the mass transfer of water vapor through membranes
during crystallization.
Abstract: In mechanical and environmental engineering, mixed
convection is a frequently encountered thermal fluid phenomenon
which exists in atmospheric environment, urban canopy flows, ocean
currents, gas turbines, heat exchangers, and computer chip cooling
systems etc... . This paper deals with a numerical investigation of
mixed convection in a vertical heated channel. This flow results from
the mixing of the up-going fluid along walls of the channel with the
one issued from a flat nozzle located in its entry section. The fluiddynamic
and heat-transfer characteristics of vented vertical channels
are investigated for constant heat-flux boundary conditions, a
Rayleigh number equal to 2.57 1010, for two jet Reynolds number
Re=3 103 and 2104 and the aspect ratio in the 8-20 range. The system
of governing equations is solved with a finite volumes method and an
implicit scheme. The obtained results show that the turbulence and
the jet-wall interaction activate the heat transfer, as does the drive of
ambient air by the jet. For low Reynolds number Re=3 103, the
increase of the aspect Ratio enhances the heat transfer of about 3%,
however; for Re=2 104, the heat transfer enhancement is of about
12%. The numerical velocity, pressure and temperature fields are
post-processed to compute the quantities of engineering interest such
as the induced mass flow rate, and average Nusselt number, in terms
of Rayleigh, Reynolds numbers and dimensionless geometric
parameters are presented.
Abstract: This research was to evaluate a technical feasibility of
making single-layer experimental particleboard panels from bamboo
waste (Dendrocalamus asper Backer) by converting bamboo into
strips, which are used to make laminated bamboo furniture. Variable
factors were density (600, 700 and 800 kg/m3) and temperature of
condition (25, 40 and 55 °C). The experimental panels were tested for
their physical and mechanical properties including modulus of
elasticity (MOE), modulus of rupture (MOR), internal bonding
strength (IB), screw holding strength (SH) and thickness swelling
values according to the procedures defined by Japanese Industrial
Standard (JIS). The test result of mechanical properties showed that
the MOR, MOE and IB values were not in the set criteria, except the
MOR values at the density of 700 kg/m3 at 25 °C and at the density
of 800 kg/m3 at 25 and 40 °C, the IB values at the density of 600
kg/m3, at 40 °C, and at the density of 800 kg/m3 at 55 °C. The SH
values had the test result according to the set standard, except with
the density of 600 kg/m3, at 40 and 55 °C. Conclusively, a valuable
renewable biomass, bamboo waste could be used to manufacture
boards.
Abstract: Nozzle is the main part of various spinning systems
such as air-jet and Murata air vortex systems. Recently, many
researchers worked on the usage of the nozzle on different spinning
systems such as conventional ring and compact spinning systems. In
these applications, primary purpose is to improve the yarn quality. In
present study, it was produced the yarns with two different nozzle
types and determined the changes in yarn properties. In order to
explain the effect of the nozzle, airflow structure in the nozzle was
modelled and airflow variables were determined. In numerical
simulation, ANSYS 12.1 package program and Fluid Flow (CFX)
analysis method was used. As distinct from the literature, Shear
Stress Turbulent (SST) model is preferred. And also air pressure at
the nozzle inlet was measured by electronic mass flow meter and
these values were used for the simulation of the airflow. At last, the
yarn was modelled and the area from where the yarn is passing was
included to the numerical analysis.
Abstract: In this paper we develop an efficient numerical method for the finite-element model updating of damped gyroscopic systems based on incomplete complex modal measured data. It is assumed that the analytical mass and stiffness matrices are correct and only the damping and gyroscopic matrices need to be updated. By solving a constrained optimization problem, the optimal corrected symmetric damping matrix and skew-symmetric gyroscopic matrix complied with the required eigenvalue equation are found under a weighted Frobenius norm sense.
Abstract: A combination of photosynthetic bacteria along with
anaerobic acidogenic bacteria is an ideal option for efficient
hydrogen production. In the present study, the optimum
concentration of substrates for the growth of Rhodobacter
sphaeroides was found by response surface methodology. The
optimum combination of three individual fatty acids was determined
by Box Behnken design. Increase of volatile fatty acid concentration
decreased the growth. Combination of sodium acetate and sodium
propionate was most significant for the growth of the organism. The
results showed that a maximum biomass concentration of 0.916 g/l
was obtained when the concentrations of acetate, propionate and
butyrate were 0.73g/l,0.99g/l and 0.799g/l, respectively. The growth
was studied under an optimum concentration of volatile fatty acids
and at a light intensity of 3000 lux, initial pH of 7 and a temperature
of 35°C.The maximum biomass concentration of 0.92g/l was
obtained which verified the practicability of this optimization.
Abstract: Despite the internet, which is one of the mass media
that has become quite common in recent years, the relationship of
Advertisement with Television and Cinema, which have always
drawn attention of researchers as basic media and where visual use is
in the foreground, have also become the subject of various studies.
Based on the assumption that the known fundamental effects of
advertisements on consumers are closely related to the creative
process of advertisements as well as the nature and characteristics of
the medium where they are used, these basic mass media (Television
and Cinema) and the consumer motivations of the advertisements
they broadcast have become a focus of study.
Given that the viewers of the mass media in question have shifted
from a passive position to a more active one especially in recent years
and approach contents of advertisements, as they do all contents, in a
more critical and “pitiless" manner, it is possible to say that
individuals make more use of advertisements than in the past and
combine their individual goals with the goals of the advertisements.
This study, which aims at finding out what the goals of these new
individual advertisement use are, how they are shaped by the distinct
characteristics of Television and Cinema, where visuality takes
precedence as basic mass media, and what kind of places they occupy
in the minds of consumers, has determined consumers- motivations
as: “Entertainment", “Escapism", “Play", “Monitoring/Discovery",
“Opposite Sex" and “Aspirations and Role Models".
This study intends to reveal the differences or similarities among
the needs and hence the gratifications of viewers who consume
advertisements on Television or at the Cinema, which are two basic
media where visuality is prioritized.
Abstract: This paper presents a speed fuzzy sliding mode
controller for a vector controlled induction machine (IM) fed by a
voltage source inverter (PWM).
The sliding mode based fuzzy control method is developed to
achieve fast response, a best disturbance rejection and to maintain a
good decoupling.
The problem with sliding mode control is that there is high
frequency switching around the sliding mode surface. The FSMC is
the combination of the robustness of Sliding Mode Control (SMC)
and the smoothness of Fuzzy Logic (FL). To reduce the torque
fluctuations (chattering), the sign function used in the conventional
SMC is substituted with a fuzzy logic algorithm.
The proposed algorithm was simulated by Matlab/Simulink
software and simulation results show that the performance of the
control scheme is robust and the chattering problem is solved.
Abstract: These Nowadays the explosion of bombs or explosive
materials such as gas and oil near or inside the buildings cause some
losses in installations and building components. This has made the
engineers to make the buildings and their components resistance
against the effects of explosion. These activities lead to provide
regulations and different methods. The above regulations are mostly
focused on the explosion effects resulting from the vehicles around
the buildings. Therefore, the explosion resulting from the vehicles
outside the buildings will be studied in this research.
In the present study, the main goals are to investigate the
explosion load effects on the structures located on the piles with the
specific quantity of plasticity and observing the permissible response
of these structures. The concentrated mass system and the spring with
two degree of freedom will be used to study the structural system.
Abstract: Healthcare issues continue to pose huge problems and incur massive costs. As a result there are many challenging problems still unresolved. In this paper, we will carry out an extensive scientific survey of different areas of management and planning in an attempt to identify where there has already been a substantial contribution from management science methods to healthcare problems and where there is a clear potential for more work to be done. The focus will be on the read-across to the healthcare domain from such approaches applied generally to management and planning and how the methods can be used to improvement patient care. We conclude that, since the healthcare domain significantly differs from traditional areas of management and planning, in some cases there is a need to modify the approaches so as to incorporate the complexities of healthcare, and fully exploit the potential for improvement.
Abstract: There has been a growing interest in utilizing surfactants in remediation processes to separate the hydrophobic volatile organic compounds (HVOCs) from aqueous solution. One attractive process is cloud point extraction (CPE), which utilizes nonionic surfactants as a separating agent. Since the surfactant cost is a key determination of the economic viability of the process, it is important that the surfactants are recycled and reused. This work aims to study the performance of the co-current vacuum stripping using a packed column for HVOCs removal from contaminated surfactant solution. Six types HVOCs are selected as contaminants. The studied surfactant is the branched secondary alcohol ethoxylates (AEs), Tergitol TMN-6 (C14H30O2). The volatility and the solubility of HVOCs in surfactant system are determined in terms of an apparent Henry’s law constant and a solubilization constant, respectively. Moreover, the HVOCs removal efficiency of vacuum stripping column is assessed in terms of percentage of HVOCs removal and the overall liquid phase volumetric mass transfer coefficient. The apparent Henry’s law constant of benzenz , toluene, and ethyl benzene were 7.00×10-5, 5.38×10-5, 3.35× 10-5 respectively. The solubilization constant of benzene, toluene, and ethyl benzene were 1.71, 2.68, 7.54 respectively. The HVOCs removal for all solute were around 90 percent.
Abstract: The proof of concept experiments were conducted to
determine the feasibility of using small amounts of Dissolved
Sulphur (DS) from the gaseous phase to precipitate platinum ions in
chloride media. Two sets of precipitation experiments were
performed in which the source of sulphur atoms was either a
thiosulphate solution (Na2S2O3) or a sulphur dioxide gas (SO2). In
liquid-liquid (L-L) system, complete precipitation of Pt was achieved
at small dosages of Na2S2O3 (0.01 – 1.0 M) in a time interval of 3-5
minutes. On the basis of this result, gas absorption tests were carried
out mainly to achieve sulphur solubility equivalent to 0.018 M. The
idea that huge amounts of precious metals could be recovered
selectively from their dilute solutions by utilizing the waste SO2
streams at low pressure seemed attractive from the economic and
environmental point of views. Therefore, mass transfer characteristics
of SO2 gas associated with reactive absorption across the gas-liquid
(G-L) interface were evaluated under different conditions of pressure
(0.5 – 2 bar), solution temperature ranges from 20 – 50 oC and acid
strength (1 – 4 M, HCl). This paper concludes with information about
selective precipitation of Pt in the presence of cations (Fe2+, Co2+,
and Cr3+) in a CSTR and recommendation to scale up laboratory data
to industrial pilot scale operations.
Abstract: Li1.5Al0.5Ti1.5 (PO4)3(LATP) has received much
attention as a solid electrolyte for lithium batteries. In this study, the
LATP solid electrolyte is prepared by the co-precipitation method
using Li3PO4 as a Li source. The LATP is successfully prepared and
the Li ion conductivities of bulk (inner crystal) and total (inner crystal
and grain boundary) are 1.1 × 10-3 and 1.1 × 10-4 S cm-1, respectively.
These values are comparable to the reported values, in which Li2C2O4
is used as the Li source. It is conclude that the LATP solid electrolyte
can be prepared by the co-precipitation method using Li3PO4 as the Li
source and this procedure has an advantage in mass production over
previous procedure using Li2C2O4 because Li3PO4 is lower price
reagent compared with Li2C2O4.
Abstract: Reinforced concrete has good durability and excellent structural performance. But there are cases of early deterioration due to a number of factors, one prominent factor being corrosion of steel reinforcement. The process of corrosion sets in due to ingress of moisture, oxygen and other ingredients into the body of concrete, which is unsound, permeable and absorbent. Cracks due to structural and other causes such as creep, shrinkage, etc also allow ingress of moisture and other harmful ingredients and thus accelerate the rate of corrosion. There are several interactive factors both external and internal, which lead to corrosion of reinforcement and ultimately failure of structures. Suitable addition of mineral admixture like silica fume (SF) in concrete improves the strength and durability of concrete due to considerable improvement in the microstructure of concrete composites, especially at the transition zone. Secondary reinforcement in the form of fibre is added to concrete, which provides three dimensional random reinforcement in the entire mass of concrete. Reinforced concrete beams of size 0.1 m X 0.15 m and length 1m have been cast using M 35 grade of concrete. The beams after curing process were subjected to corrosion process by impressing an external Direct Current (Galvanostatic Method) for a period of 15 days under stressed and unstressed conditions. The corroded beams were tested by applying two point loads to determine the ultimate load carrying capacity and cracking pattern and the results of specimens were compared with that of the companion specimens. Gravimetric method is used to quantify corrosion that has occurred.
Abstract: Truss spars are used for oil exploitation in deep and ultra-deep water if storage crude oil is not needed. The linear hydrodynamic analysis of truss spar in random sea wave load is necessary for determining the behaviour of truss spar. This understanding is not only important for design of the mooring lines, but also for optimising the truss spar design. In this paper linear hydrodynamic analysis of truss spar is carried out in frequency domain. The hydrodynamic forces are calculated using the modified Morison equation and diffraction theory. Added mass and drag coefficients of truss section computed by transmission matrix and normal acceleration and velocity component acting on each element and for hull section computed by strip theory. The stiffness properties of the truss spar can be separated into two components; hydrostatic stiffness and mooring line stiffness. Then, platform response amplitudes obtained by solved the equation of motion. This equation is non-linear due to viscous damping term therefore linearised by iteration method [1]. Finally computed RAOs and significant response amplitude and results are compared with experimental data.
Abstract: The exhaustive quality control is becoming more and
more important when commercializing competitive products in the
world's globalized market. Taken this affirmation as an undeniable
truth, it becomes critical in certain sector markets that need to offer
the highest restrictions in quality terms. One of these examples is the
percussion cap mass production, a critical element assembled in
firearm ammunition. These elements, built in great quantities at a
very high speed, must achieve a minimum tolerance deviation in
their fabrication, due to their vital importance in firing the piece of
ammunition where they are built in. This paper outlines a machine
vision development for the 100% inspection of percussion caps
obtaining data from 2D and 3D simultaneous images. The acquisition
speed and precision of these images from a metallic reflective piece
as a percussion cap, the accuracy of the measures taken from these
images and the multiple fabrication errors detected make the main
findings of this work.
Abstract: We successfully developed and tested a new
separation layer solving problems with unmanageable deposits inside the boilers of Zluticka Heating Plant. The deposits are mainly created
by glass-forming melts. We plotted straw ash compositions in K2OCaO-
SiO2 phase diagram and illustrated that they are in the area of low-melting eutectic points. To prevent the melting of ash and the
formation of deposits, we modified ash compositions by injecting additives into biomass fuel, and thus effectively suppressed deposits in a burner.