Abstract: This paper was to study the clothes dryer using waste
heat from a split type air conditioner with a capacity of 12,648 btu/h.
The drying chamber had a minimum cross section area with the size
of 0.5 x 1.0 m2. The chamber was constructed by sailcloth and was
inside folded with aluminium foil. Then, it was connected to the
condensing unit of an air conditioner. The experiment was carried out
in two aspects which were the clothes drying with and without
auxiliary fan unit. The results showed that the drying rate of clothes
in the chamber installed with and without auxiliary fan unit were
2.26 and 1.1 kg/h, respectively. In case of the chamber installed with
a auxiliary fan unit, the additional power of 0.011 kWh was
consumed and the drying rate was higher than that of clothes drying
without auxiliary fan unit. Without auxiliary fan unit installation, no
energy was required but there was a portion of hot air leaks away
through the punctured holes at the wall of the drying chamber, hence
the drying rate was dropped below. The drying rate of clothes drying
using waste heat was higher than natural indoor drying and
commercial dryer which their drying rate were 0.17 and 1.9 kg/h,
respectively. It was noted that the COP of the air conditioner did not
change during the operating of clothes drying.
Abstract: The present work analyses different parameters of pressure die casting to minimize the casting defects. Pressure diecasting is usually applied for casting of aluminium alloys. Good surface finish with required tolerances and dimensional accuracy can be achieved by optimization of controllable process parameters such as solidification time, molten temperature, filling time, injection pressure and plunger velocity. Moreover, by selection of optimum process parameters the pressure die casting defects such as porosity, insufficient spread of molten material, flash etc. are also minimized. Therefore, a pressure die casting component, carburetor housing of aluminium alloy (Al2Si2O5) has been considered. The effects of selected process parameters on casting defects and subsequent setting of parameters with the levels have been accomplished by Taguchi-s parameter design approach. The experiments have been performed as per the combination of levels of different process parameters suggested by L18 orthogonal array. Analyses of variance have been performed for mean and signal-to-noise ratio to estimate the percent contribution of different process parameters. Confidence interval has also been estimated for 95% consistency level and three conformational experiments have been performed to validate the optimum level of different parameters. Overall 2.352% reduction in defects has been observed with the help of suggested optimum process parameters.
Abstract: The objective of this research was to determine the
potency of indigenous acid-aluminium tolerant Bradyrhizobium
japonicum as producer of indole acetic acid (IAA) and applied it as
nitrogen fixation on local soybeans viz Anjasmoro, Tanggamus
(yellow soybean seeds), and Detam (black soybean seed). Three
isolates of acid-aluminium tolerant Bradyrhizobium japonicum (BJ)
were used in this research, i.e. BJ 11 (wt), BJ 11 (19) - BJ 11(wt)
mutant, and USDA 110 as a reference isolate. All of isolates tested to
produce the IAA by using Salkowsky method. Effect of IAA
production by each of B. japonicum was tested on growth pouch and
greenhouse using three varieties of soybean. All isolates could grow
well and produce IAA on yeast mannitol broth (YMB) medium in
the presence of 0.5 mM L-tryptophan. BJ 11 (19) produced the
highest of IAA at 4 days incubation compared to BJ 11 (wt) and
USDA 110. All tested isolates of Bradyrhizobium japonicum have
showed effect on stimulating the formation of root nodules in
soybean varieties grown on Leonard bottle. The concentration of
IAA on root nodules of soybean symbiotic with B. japonicum was
significantly different with control, except on the treatment using
Tanggamus soybean.
Abstract: Fluids are used for heat transfer in many engineering
equipments. Water, ethylene glycol and propylene glycol are some
of the common heat transfer fluids. Over the years, in an attempt to
reduce the size of the equipment and/or efficiency of the process,
various techniques have been employed to improve the heat transfer
rate of these fluids. Surface modification, use of inserts and
increased fluid velocity are some examples of heat transfer
enhancement techniques. Addition of milli or micro sized particles
to the heat transfer fluid is another way of improving heat transfer
rate. Though this looks simple, this method has practical problems
such as high pressure loss, clogging and erosion of the material of
construction. These problems can be overcome by using nanofluids,
which is a dispersion of nanosized particles in a base fluid.
Nanoparticles increase the thermal conductivity of the base fluid
manifold which in turn increases the heat transfer rate. In this work,
the heat transfer enhancement using aluminium oxide nanofluid has
been studied by computational fluid dynamic modeling of the
nanofluid flow adopting the single phase approach.
Abstract: This paper concerns about the experimental and
numerical investigations of energy absorption and axial tearing
behaviour of aluminium 6060 circular thin walled tubes under static
axial compression. The tubes are received in T66 heat treatment
condition with fixed outer diameter of 42mm, thickness of 1.5mm
and length of 120mm. The primary variables are the conical die
angles (15°, 20° and 25°). Numerical simulations are carried on
ANSYS/LS-DYNA software tool, for investigating the effect of
friction between the tube and the die.
Abstract: Addition of milli or micro sized particles to the heat
transfer fluid is one of the many techniques employed for improving
heat transfer rate. Though this looks simple, this method has
practical problems such as high pressure loss, clogging and erosion
of the material of construction. These problems can be overcome by
using nanofluids, which is a dispersion of nanosized particles in a
base fluid. Nanoparticles increase the thermal conductivity of the
base fluid manifold which in turn increases the heat transfer rate.
Nanoparticles also increase the viscosity of the basefluid resulting in
higher pressure drop for the nanofluid compared to the base fluid. So
it is imperative that the Reynolds number (Re) and the volume
fraction have to be optimum for better thermal hydraulic
effectiveness. In this work, the heat transfer enhancement using
aluminium oxide nanofluid using low and high volume fraction
nanofluids in turbulent pipe flow with constant wall temperature has
been studied by computational fluid dynamic modeling of the
nanofluid flow adopting the single phase approach. Nanofluid, up till
a volume fraction of 1% is found to be an effective heat transfer
enhancement technique. The Nusselt number (Nu) and friction factor
predictions for the low volume fractions (i.e. 0.02%, 0.1 and 0.5%)
agree very well with the experimental values of Sundar and Sharma
(2010). While, predictions for the high volume fraction nanofluids
(i.e. 1%, 4% and 6%) are found to have reasonable agreement with
both experimental and numerical results available in the literature.
So the computationally inexpensive single phase approach can be
used for heat transfer and pressure drop prediction of new nanofluids.
Abstract: Water, soil and sediment contaminated with
metolachlor poses a threat to the environment and human health.
We determined the effectiveness of nano-zerovalent iron (NZVI) to
dechlorinate metolachlor [2-chloro-n-(2-ethyl-6-methyl-phenyl)-n-
(1-methoxypropan-2-yl)acetamide] in pH solution and the presence
of aluminium salt. The optimum dosage of degradation of 100 mlL-1
metolachlor was 1% (w/v) NZVI. The degradation kinetic rate (kobs)
was 0.218×10-3 min-1 and specific first-order rates (kSA) was
8.72×10-7 L m-2min-1. By treating aqueous solutions of metolachlor
with NZVI, metolachlor destruction rate were increased as the pH
decrease from 10 to 4. Lowering solution pH removes Fe (III)
passivating layers from the NZVI and makes it free for reductive
transformations. Destruction kinetic rates were 20.8×10-3 min-1 for
pH4, 18.9×10-3 min-1 for pH7, 13.8×10-3 min-1 for pH10. In addition,
destruction kinetic of metolachlor by NZVI was enhanced when
aluminium sulfate was added. The destruction kinetic rate were
20.4×10-3 min-1 for 0.05% Al(SO4)3 and 60×10-3 min-1 for 0.1%
Al(SO4)3.
Abstract: End milling process is one of the common metal
cutting operations used for machining parts in manufacturing
industry. It is usually performed at the final stage in manufacturing a
product and surface roughness of the produced job plays an
important role. In general, the surface roughness affects wear
resistance, ductility, tensile, fatigue strength, etc., for machined parts
and cannot be neglected in design. In the present work an
experimental investigation of end milling of aluminium alloy with
carbide tool is carried out and the effect of different cutting
parameters on the response are studied with three-dimensional
surface plots. An artificial neural network (ANN) is used to establish
the relationship between the surface roughness and the input cutting
parameters (i.e., spindle speed, feed, and depth of cut). The Matlab
ANN toolbox works on feed forward back propagation algorithm is
used for modeling purpose. 3-12-1 network structure having
minimum average prediction error found as best network architecture
for predicting surface roughness value. The network predicts surface
roughness for unseen data and found that the result/prediction is
better. For desired surface finish of the component to be produced
there are many different combination of cutting parameters are
available. The optimum cutting parameter for obtaining desired
surface finish, to maximize tool life is predicted. The methodology is
demonstrated, number of problems are solved and algorithm is coded
in Matlab®.
Abstract: This work is focused on the numerical prediction of the fracture resistance of a flat stiffened panel made of the aluminium alloy 2024 T3 under a monotonic traction condition. The performed numerical simulations have been based on the micromechanical Gurson-Tvergaard (GT) model for ductile damage. The applicability of the GT model to this kind of structural problems has been studied and assessed by comparing numerical results, obtained by using the WARP 3D finite element code, with experimental data available in literature. In the sequel a home-made procedure is presented, which aims to increase the residual strength of a cracked stiffened aluminum panel and which is based on the stochastic design improvement (SDI) technique; a whole application example is then given to illustrate the said technique.
Abstract: Removal of a reactive dye (Reactive blue 4) by
adsorption utilizing waste aluminium hydroxide sludge as an
adsorbent was investigated. The removal of the dye was optimized
using response surface methodology (RSM). In the RSM
experiments; initial dye concentration, adsorbent concentration and
contact time were critical parameters. RSM experiments were
performed at the range of initial dye concentration 31.82-368.18
mg/L, adsorbent concentration 3.18-36.82 g/L, contact time 15.82-
56.18 h. Optimum initial dye concentration, adsorbent concentration
and contact time were obtained as 108.83 mg/L, 29.36 g/L and 33.57
h respectively. At these conditions, maximum removal of the dye was
obtained as 95%. The experiments were performed at the optimum
conditions to verify these results and the same results were obtained.
Abstract: This study reports an empirical investigation of
fatigue crack initiation and propagation in 2024 T351 aluminium
alloy using constant amplitude loading. In initiation stage, local
strain approach at the notch was used and in stable propagation stage
NASGRO model was applied.
In this investigation, the flat plate of double through crack at hole
is used. Based on experimental results (AFGROW Database), effect
of stress ratio, R, is highlights on fatigue initiation life (FIL) and
fatigue crack growth rate (FCGR). The increasing of dimension of
hole characterizing the notch effect decrease the fatigue life.
Abstract: Independent component analysis (ICA) is a computational method for finding underlying signals or components from multivariate statistical data. The ICA method has been successfully applied in many fields, e.g. in vision research, brain imaging, geological signals and telecommunications. In this paper, we apply the ICA method to an analysis of mass spectra of oligomeric species emerged from aluminium sulphate. Mass spectra are typically complex, because they are linear combinations of spectra from different types of oligomeric species. The results show that ICA can decomposite the spectral components for useful information. This information is essential in developing coagulation phases of water treatment processes.
Abstract: Explosive welding is a process which uses explosive
detonation to move the flyer plate material into the base material to
produce a solid state joint. Experimental tests have been carried out
by other researchers; have been considered to explosively welded
aluminium 7039 and steel 4340 tubes in one step. The tests have been
done using various stand-off distances and explosive ratios. Various
interface geometries have been obtained from these experiments. In
this paper, all the experiments carried out were simulated using the
finite element method. The flyer plate and collision velocities
obtained from the analysis were validated by the pin-measurement
experiments. The numerical results showed that very high localized
plastic deformation produced at the bond interface. The
Ls_dyna_971 FEM has been used for all simulation process.
Abstract: This paper reports the tensile fracture location
characterizations of dissimilar friction stir welds between 5754
aluminium alloy and C11000 copper. The welds were produced using
three shoulder diameter tools; namely, 15, 18 and 25 mm by varying
the process parameters. The rotational speeds considered were 600,
950 and 1200 rpm while the feed rates employed were 50, 150 and
300 mm/min to represent the low, medium and high settings
respectively. The tensile fracture locations were evaluated using the
optical microscope to identify the fracture locations and were
characterized. It was observed that 70% of the tensile samples failed
in the Thermo Mechanically Affected Zone (TMAZ) of copper at the
weld joints. Further evaluation of the fracture surfaces of the pulled
tensile samples revealed that welds with low Ultimate Tensile
Strength either have defects or intermetallics present at their joint
interfaces.
Abstract: The aim of the work was to attenuate the vibration amplitude in CESNA 172 airplane wing by using Functionally Graded Material instead of uniform or composite material. Wing strength was achieved by means of stress analysis study, while wing vibration amplitudes and shapes were achieved by means of Modal and Harmonic analysis. Results were verified by applying the methodology in a simple cantilever plate to the simple model and the results were promising and the same methodology can be applied to the airplane wing model. Aluminum models, Titanium models, and functionally graded materials of Aluminum and titanium results were compared to show a great vibration attenuation after using the FGM. Optimization in FGM gradation satisfied our objective of reducing and attenuating the vibration amplitudes to show the effect of using FGM in vibration behavior. Testing the Aluminum rich models, and comparing it with the titanium rich model was an optimization in this paper. Results have shown a significant attenuation in vibration magnitudes when using FGM instead of Titanium Plate, and Aluminium wing with FGM Spurs instead of Aluminium wings. It was also recommended that in future, changing the graphical scale to 1:10 or even 1:1 when the computers- capabilities allow.
Abstract: In this study, mechanically alloyed Al 2024 powder is
densified by conventional sintering and by equal channel angular
pressing (ECAP) with and without back pressure. The powder was
encapsulated in an aluminium can for consolidation through ECAP.
The properties obtained in the compacts by conventional sintering
route and by ECAP are compared. The effect of conventional
sintering and ECAP on consolidation behaviour of powder,
microstructure, density and hardness is discussed. Room temperature
back pressure aided ECAP results in nearly full denser (97% of its
theoretical density) compact at room temperature. NanoIndentation
technique was used to determine the modulus of the consolidated
compacts.
Abstract: Paper presents knowledge about types of test in area
of materials properties of selected methods of rapid prototyping
technologies. In today used rapid prototyping technologies for
production of models and final parts are used materials in initial state
as solid, liquid or powder material structure. In solid state are used
various forms such as pellets, wire or laminates. Basic range
materials include paper, nylon, wax, resins, metals and ceramics. In
Fused Deposition Modeling (FDM) rapid prototyping technology are
mainly used as basic materials ABS (Acrylonitrile Butadiene
Styrene), polyamide, polycarbonate, polyethylene and polypropylene.
For advanced FDM applications are used special materials as silicon
nitrate, PZT (Piezoceramic Material - Lead Zirconate Titanate),
aluminium oxide, hydroxypatite and stainless steel.
Abstract: The aim of this study was to investigate ammonium
exchange capacity of natural and activated clinoptilolite from
Kwazulu-Natal Province, South Africa. X – ray fluorescence (XRF)
analysis showed that the clinoptilolite contained exchangeable ions
of sodium, potassium, calcium and magnesium. This analysis also
confirmed that the zeolite sample had a high silicon composition
compared to aluminium. Batch equilibrium studies were performed
in an orbital shaker and the data fitted the Langmuir isotherm very
well. The ammonium exchange capacity was found to increase with
pH and temperature. Clinoptilolite functionalization with
hydrochloric acid increased its ammonia uptake ability.
Abstract: Fatigue cracking continues to be the main challenges in
improving the performance of bituminous mixture pavements. The
purpose of this paper is to look at some aspects of the effects of fine
aggregate properties on the fatigue behaviour of hot mixture asphalt.
Two types of sand (quarry and mining sand) with two conventional
bitumen (PEN 50/60 & PEN 80/100) and four polymers modified
bitumen PMB (PM1_82, PM1_76, PM2_82 and PM2_76) were used.
Physical, chemical and mechanical tests were performed on the sands
to determine their effect when incorporated with a bituminous
mixture. According to the beam fatigue results, quarry sand that has
more angularity, rougher, higher shear strength and a higher
percentage of Aluminium oxide presented higher resistance to
fatigue. Also a PMB mixture gives better fatigue results than
conventional mixtures, this is due to the PMB having better viscosity
property than that of the conventional bitumen.
Abstract: This paper features the modeling and design of a Fast
Output Sampling (FOS) Feedback control technique for the Active
Vibration Control (AVC) of a smart flexible aluminium cantilever
beam for a Single Input Single Output (SISO) case. Controllers are
designed for the beam by bonding patches of piezoelectric layer as
sensor / actuator to the master structure at different locations along
the length of the beam by retaining the first 2 dominant vibratory
modes. The entire structure is modeled in state space form using the
concept of piezoelectric theory, Euler-Bernoulli beam theory, Finite
Element Method (FEM) and the state space techniques by dividing
the structure into 3, 4, 5 finite elements, thus giving rise to three
types of systems, viz., system 1 (beam divided into 3 finite
elements), system 2 (4 finite elements), system 3 (5 finite elements).
The effect of placing the sensor / actuator at various locations along
the length of the beam for all the 3 types of systems considered is
observed and the conclusions are drawn for the best performance and
for the smallest magnitude of the control input required to control the
vibrations of the beam. Simulations are performed in MATLAB. The
open loop responses, closed loop responses and the tip displacements
with and without the controller are obtained and the performance of
the proposed smart system is evaluated for vibration control.