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    Influence of ethanol-biodiesel blends on diesel engines combustion behavior and particulate matter physicochemical characteristics
    (2022-12-01)
    Karin, Preechar
    ;
    Tripatara, Aphichai
    ;
    Wai, Phyo
    ;
    Oh, Ban Seok
    ;
    Charoenphonphanich, Chinda
    Ethanol-blended biodiesel fuel can reduce smoke emissions by over 50% on both a single-cylinder engine and a four-cylinder engine. The average single primary particle size of biodiesel blended diesel, biodiesel, and ethanol blended biodiesel soot are approximately 30, 27, and 29 nm, respectively. The maximum graphene fringe length of biodiesel blended diesel, biodiesel, and ethanol blended biodiesel CI engine's soot are approximately 5.2, 4.6, and 4.5 nm. The carbon atom density of soot particles emitted from the diesel, biodiesel, and ethanol blended biodiesel CI engines are approximately 102, 91, and 88 atoms/nm3.
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    Physicomechanical Characteristics of Carbon Fiber Reinforced Polymer Composite Using X-Ray Diffraction, Atomic Force and Electron Microscopies
    (2022-10-01)
    Lin, Ye Htet
    ;
    Karin, Preechar
    ;
    Larpsuriyakul, Patcharee
    ;
    Ohtake, Naoto
    The physicomechanical characteristics of PAN-based carbon fibers were investigated by SEM-EDS, XRD, TEM and AFM analysis while the mechanical properties of the composites were studied by tensile, flexural and Charpy impact tests with ASTM standards. Regarding the tensile test of carbon fiber fabric, the average tensile strength of CF-I, CF-II and CF-III fibers were around 147 MPa, 137 MPa and 225 MPa and the tensile modulus of those were 12.8 GPa, 13.2 GPa and 12.8 GPa, respectively. Later, the nanostructure of carbon fiber was recognized not as a pure graphite carbon structure because they mixed with graphite and amorphous structures. The higher tensile strength and modulus of CF-III fiber fabric was lower interlayer spacing (d002) because it consisted of more graphene layers in the graphite structure when compared with CF-I and CF-II fiber fabrics. Concerning AFM analysis’s results, CF-I fiber fabric has higher surface roughness (Ra) of 34.8 nm and more in-depth with wider pit lines along the fiber axis, which caused higher mechanical properties among the three composites. According to this article, the nanostructure of carbon fibers had a lower impact on CFRP composite because the interfacial bonding between fiber and epoxy matrix, which obtained the higher mechanical properties in the composite, was directly enhanced by the higher surface roughness of the fibers.
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    Impact of soot nanoparticle size and quantity on four-ball steel wear characteristics using EDS, XRD and electron microscopy image analysis
    (2022-01-01)
    Karin, Preechar
    ;
    Chammana, Pattara
    ;
    Oungpakornkaew, Pitchaporn
    ;
    Rungsritanapaisan, Panyakorn
    ;
    Amornprapa, Warawut
    The effect of soot contamination on the tribological performance of engine oil was investigated. Carbon black is introduced to simplify diesel engine soot contamination. Besides, the tribological performance issue is verified by a four-ball tribometer. The steel ball worn surfaces were studied by Scanning Electron Microscopy (SEM), Optical Microscope (OM) and Energy Dispersive X-ray spectroscopy (EDX). In addition, Transmission Electron Microscopy (TEM) was used to investigate the morphology and nanostructure of soot and carbon black. According to the four ball test results, the average wear scar diameter of steel ball tested with engine oil blended with N220, N330, N550 and N660 by 1% by weight is larger than that of pure engine oil by 26%, 38%, 41%, and 39%, respectively. The wear scar diameter tends to increase after blended larger size of carbon black particle. The steel balls tested with formulated engine oil without soot contamination and with soot contamination by 0.5 wt%, 1 wt%, and 2 wt% have average wear scar diameters of 621, 567, 784 and 894 nm, respectively. On the other hand, wear scar roughness of steel balls tested with formulated engine oil without soot contamination and with soot contamination by 0.5 wt%, 1 wt%, and 2 wt% were 2.28, 0.25, 1.49 and 1.76 μm, respectively. Consequently, quantity of the soot nanoparticle approximately 0.5% by mass in engine oil significantly plays an important role in steel ball wear scar diameter and surface roughness reduction. Moreover, the agglomerated soot which is larger than the oil film thickness might block the lubricant from entering the contact. It leads to the breakdown of the oil film thickness resulting in increasing adhesive wear on the worn surface.