Abstract: Thermal decomposition characteristic of waste material from oil extraction of Jatropha
(physic nut), including shell and kernel, was investigated using thermogravimetric analysis (TGA)
and pyrolysis experiments. Effects of heating rate (5-90°C/min), reaction temperature (500-900°C)
and hold time at final temperature (3-15 min) on the feature of thermogram, kinetic parameters as
well as product distribution were evaluated. Thermal conversion of this residue composed of
cellulose, hemicellulose, and lignin degradation steps with maximum weight losses around 250 to
450°C. The order of reaction increased with temperature from 0.28 at 250°C to 0.81 at 450°C. The
activation energies ranging from 105-184 kJ/mol depend on the stage of devolatilization. The
amount of gas product increased with temperature with the expense of reducing char and liquid
from secondary heterogeneous cracking reactions. More than 14% of hydrogen in residue was
converted to H2 during pyrolysis at 900°C. Major hydrocarbon gases are those of C4+ species with
measurable amount of CH4 and C2 derivatives. Increase in reaction temperature can lead to a
noticeable increase of hydrogen and hydrocarbon gas yields. Addition of catalyst and steam would
promote the formation of fuel gas from this waste material.
Abstract: The spherical indentation obeys Hertz contact theory when the applied load is within the
elastic limit. Once the applied load is over the elastic limit, the indentation curve starts to deviate
from the original purely elastic indentation curve. This deviation point, which indicates the start of
the nonlinear deformation, is an important characteristic of a spherical indentation curve. The
indentation force corresponding to the deviation point is related to a basic material constant, which
is the yield stress for an elastic-plastic material or the transformation stress for a shape memory
alloy. This relationship can be applied to measure the yield stress or the transformation stress from a
simple spherical indentation curve. Detailed discussion on the relationship and the method is
presented in this short paper.
Abstract: The microstructures of high-temperature oxide scales on the Si-terminated surface and
C-terminated surface of 6H-SiC were investigated by transmission electron microscopy (TEM). We
found that mechanical polishing caused surface strains, about 100 nm in depth, on both sides of
specimens. Mechanically polished specimens were oxidized at 1473 K for 20 h in air. Oxide scales
of about 250 nm in thickness were formed on the Si-terminated surface and of about 400 nm on the
C-terminated surface. Since the strain regions caused by mechanical polishing were oxidized,
strains were no longer observed. As a result, this oxidation condition effectively removed the strains.
The oxide scales were identified as amorphous silica on the Si-terminated face, while crystalline
oxides and amorphous silica were observed on the C-terminated face.
Abstract: Metal injection molding (MIM) process has the advantage of better formability of three
dimensional complex shape products with high density and high performance properties
compared to the ingot metallurgy (I/M) process. Two kinds of pure titanium specimens, i.e., the first
one is prepared by the I/M process and the second one is prepared by MIM process are used in this
experiment, and their corrosion behavior under stress has been investigated in several aqueous
solutions by Slow Strain Rate Tensile (SSRT) test. Both I/M and MIM specimens showed good
corrosion resistance in the aqueous solution composed of 2.5 kmol/m3 H2SO4 and 0.2 kmol/m3
NaCl as well as saline solution. This aqueous solution is noted one in which Type 304 stainless steel
showed SCC. In the aqueous solution composed of CH3OH and 0.1 kmol/m3 HCl containing
8.6kg/m3 H2O, the elongation of MIM specimen was slightly higher than that of I/M specimen
though both specimens indicated the remarkable decrease in elongation.
Abstract: The extruded AZ31B Mg alloy specimens using powders fabricated by roll compaction
processing (RCP) was prepared, and their corrosion behavior has been investigated through the
polarization test, electrochemical impedance spectroscopy test, immersion test and SEM
observation in comparison to that of the conventional AZ31B Mg alloy, hereafter shortened as I/M
specimen. The extruded AZ31B Mg alloys using RCP powder showed little change in Ecorr
irrespective of number of pass cycles. Both anodic and cathodic current density suppression of the
RCP specimens became larger with an increase in number of pass cycles. It was also confirmed that
the corrosion characteristics of the RCP specimens depended strongly on their structural
morphology and that the corrosion resistance of the RCP specimens subjected to 50 pass cycles was
nearly same as that of the I/M specimen.
Abstract: Three cemented carbide specimens, i.e., WC-Co (Sample A), WC-Cr3C2-Co (Sample B)
and WC-βt-Co (Sample C) in which βt indicates (Ti,W,Ta,Nb)C, are prepared by liquid phase
sintering, and their corrosion behavior has been investigated by the electrochemical methods. The
similar activation, passive state and over passive state regions as SUS304 stainless steel during the
polarization test, and the preferential dissolution of Co were observed for all of the three specimens
mentioned above. Both Cr3C2 and βt improved the corrosion resistance of WC-Co alloy, in which
the effect of the former was better than that of the latter. Sample B also showed the best corrosion
resistance in all the samples for the electrochemical impedance spectroscopy (EIS) test.
Abstract: Crack formation by a rolling contact fatigue in a high carbon chromium bearing steel has
been discussed. Newly developed method for preparing specimens including pre-existing voids
enabled one to observe the early stage of fatigue crack formation. Many fatigue cracks were formed
around the voids. The positions of crack formation and the direction of the cracks were consistent
with those forecasted by finite element analysis. Fatigue crack formation was followed by formation
of the WEAs.
Abstract: The particle size distributions of tin oxide powders produced from the calcining of
precipitated tin oxalate were determined by four methods, these being two static and two dynamic
light scattering techniques. Although the individual particle sizes were ~ 75 nm, all of the powders
were heavily agglomerated as plates. The non-spherical shape resulted in the following
• None of the measurements was in agreement with any others.
• There were very significant disagreements between the two light scattering methods.
• The particle size distributions were multimodal.
• The main peaks in the distribution curves, which were used to calculate the averages and standard
deviations, were not Gaussian.
The main uncertainty with these data is associated with the non-spherical agglomerates, which
result in the multimodal size distributions. These probably were caused by variable-sized but large
Abstract: Anodic oxidation has been used to make well adhered and porous (≤1 μm pore diameter)
thin films of anatase on titanium using electrolytic solutions with combinations of H2SO4, H3PO4, and
H2O2. The crystallinity, film thickness, and pore size and number increase with time and voltage. The
voltage is limited to ~180 V by electrolysis and/or breakdown and the film thickness is ≤3 μm.
Abstract: Rutile nano-powders were suspended in a solution of acetylacetone and iodine. The
suspensions were electrophoretically deposited on titanium foil at a voltage range of 5-30 V over
times of 5-120 s. The dried tapes then were sintered at 800°C for 2 h in flowing argon. Both the
green and fired tapes were examined by field emission scanning electron microscopy, optical
microscopy, X-ray diffraction, and Raman microspectroscopy.
The thickness of the films depended on the voltage and the time of deposition. The sintered
microstructures depended significantly on the thickness of the film, which was a function the
proximity to the Ti/TiO2 interface. The interface is critical to the microstructure because it acts as
the source of defect formation, which enhances sintering, grain growth, and grain facetting.