Abstract: Swedish truck industry is investigating the possibility
for implementing the use of Compacted Graphite Iron (CGI) in their
heavy duty diesel engines. Compared to the alloyed gray iron used
today, CGI has superior mechanical properties but not as good
machinability. Another issue that needs to be addressed when
implementing CGI is the inhomogeneous microstructure when the
cast component has different section thicknesses, as in cylinder
blocks. Thinner sections results in finer pearlite, in the material, with
higher strength. Therefore an investigation on its influence on
machinability was needed. This paper focuses on the effect that
interlamellar distance in pearlite has on CGI machinability and
material physical properties. The effect of pearlite content and
nodularity is also examined. The results showed that interlamellar
distance in pearlite did not have as large effect on the material
physical properties or machinability as pearlite content. The paper
also shows the difficulties of obtaining a homogeneous
microstructure in inhomogeneous workpieces.
Abstract: Saturated hydraulic conductivity is one of the soil
hydraulic properties which is widely used in environmental studies
especially subsurface ground water. Since, its direct measurement is
time consuming and therefore costly, indirect methods such as
pedotransfer functions have been developed based on multiple linear
regression equations and neural networks model in order to estimate
saturated hydraulic conductivity from readily available soil
properties e.g. sand, silt, and clay contents, bulk density, and organic
matter. The objective of this study was to develop neural networks
(NNs) model to estimate saturated hydraulic conductivity from
available parameters such as sand and clay contents, bulk density,
van Genuchten retention model parameters (i.e. r
θ , α , and n) as well
as effective porosity. We used two methods to calculate effective
porosity: : (1) eff s FC φ =θ -θ , and (2) inf φ =θ -θ eff s , in which s
θ is
saturated water content, FC θ is water content retained at -33 kPa
matric potential, and inf θ is water content at the inflection point.
Total of 311 soil samples from the UNSODA database was divided
into three groups as 187 for the training, 62 for the validation (to
avoid over training), and 62 for the test of NNs model. A commercial
neural network toolbox of MATLAB software with a multi-layer
perceptron model and back propagation algorithm were used for the
training procedure. The statistical parameters such as correlation
coefficient (R2), and mean square error (MSE) were also used to
evaluate the developed NNs model. The best number of neurons in
the middle layer of NNs model for methods (1) and (2) were
calculated 44 and 6, respectively. The R2 and MSE values of the test
phase were determined for method (1), 0.94 and 0.0016, and for
method (2), 0.98 and 0.00065, respectively, which shows that method
(2) estimates saturated hydraulic conductivity better than method (1).
Abstract: Offset Double-Disk Opener (DDO) is a popular
furrow opener in conservation tillage. It has some limitations such as
negative suction to penetrate in the soil, hair pinning and mixing seed
and fertilizer in the slot. Because of importance of separation of seed
and fertilizer in the slot, by adding two horizontal mini disks to DDO
a modified opener was made (MDO) which placed the fertilizer
between and under two rows of seed. To consider performance of
novel opener an indoor comparison test between DDO and MDO was
performed at soil bin. The experiment was conducted with three
working speeds (3, 6 and 8 km h-1), two bulk densities of soil (1.1
and 1.4 Mg m-3) and two levels of residues (1 and 2 ton ha-1). The
experimental design consisted in a (3×2×2) complete randomized
factorial with three replicates for each test. Moisture of seed furrow,
separation of seed and fertilizer, hair pinning and resultant forces
acting on the openers were used as assessing indexes. There was no
significant difference between soil moisture content in slots created
by DDO and MDO at 0-4 cm depth, but at 4-8 cm the in the slot
created by MDO moisture content was higher about 9%. Horizontal
force for both openers increased with increasing speed and soil bulk
density. Vertical force for DDO was negative so it needed additional
weight for penetrating in the soil, but vertical force for MDO was
positive and, which can solve the challenge of penetration in the soil
in DDO. In soft soil with heavy residues some trash was pushed by
DDO into seed furrow (hair pinning) but at MDO seed were placed at
clean groove. Lateral and vertical separation of seed and fertilizer
was performed effectively by MDO (4.5 and 5 cm, respectively)
while DDO put seed and fertilizer close to each other. Overall, the
Modified Offset Double-disks (MDO) had better performance. So by
adapting this opener with no-tillage drillers it would possible to have
higher yield in conservation tillage where the most appropriate
opener is disk type.
Abstract: The application of agro-industrial waste in Aluminum
Metal Matrix Composites has been getting more attention as they
can reinforce particles in metal matrix which enhance the strength
properties of the composites. In addition, by applying these agroindustrial
wastes in useful way not only save the manufacturing cost
of products but also reduce the pollutions on environment. This
paper represents a literature review on a range of industrial wastes
and their utilization in metal matrix composites. The paper describes
the synthesis methods of agro-industrial waste filled metal matrix
composite materials and their mechanical, wear, corrosion, and
physical properties. It also highlights the current application and
future potential of agro-industrial waste reinforced composites in
aerospace, automotive and other construction industries.
Abstract: Some physical properties of musk lime (Citrus
microcarpa) were determined in this study. The average moisture
content (wet basis) of the fruit was found to be 85.10 (±0.72) %. The
mean of length, width and thickness of the fruit was 26.36 (±0.97),
26.40 (±1.04) and 25.26 (±0.94) mm respectively. The average value
for geometric mean diameter, sphericity, aspect ratio, mass, surface
area, volume, true density, bulk density and porosity was 26.00
(±0.82) mm, 98.67 (±2.04) %, 100.23 (±3.28) %, 10.007 (±0.878) g,
2125.07 (±133.93) mm2, 8800.00 (±731.82) mm3, 1002.87 (±39.16)
kgm-3, 501.70 (±22.58) kgm-3 and 49.89 (±3.15) % respectively.
The coefficient of static friction on four types of structural surface
was found to be varying from 0.238 (±0.025) for glass to 0.247
(±0.024) for steel surface.
Abstract: This report shows the performance of composite
biodegradable film from chitosan, starch and sawdust fiber. The main
objectives of this research are to fabricate and characterize composite
biodegradable film in terms of morphology and physical properties.
The film was prepared by casting method. Sawdust fiber was used as
reinforcing agent and starch as polymer matrix in the casting
solution. The morphology of the film was characterized using atomic
force microscope (AFM). The result showed that the film has
smooth structure. Chemical composition of the film was investigated
using Fourier transform infrared (FTIR) where the result revealed
present of starch in the film. The thermal properties were
characterized using thermal gravimetric analyzer (TGA) and
differential scanning calorimetric (DSC) where the results showed
that the film has small difference in melting and degradation
temperature.