• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.85-89
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• 1996

This paper was undertaken to analyze the morphology of wear debris for operating condition evaluatio of lubricated machine surfaces. The lubricating wear test was carried out under different experimental conditions using tile wear test device was made in our laboritory and wear testing spcimen of the pin on disk type was rubbed in paraffine series base oil, by varying specimen, applied load, sliding distance. The four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) to describe morphology of wear debris have been developed and are outlined in tile paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology in machine condition monitoring

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.167-168
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• 2006

A hyrdrothermal synthesis has been developd to prepare rod-like crystals of copper oxide using copper nitrate trihydrate as a function of synthesis temperature, stirring speed and solution pH value. The properties of the fabricated crystals were studied using scanning electron microscopy, X-ray diffraction and particle size analysis. The morphology of the synthesized CuO was dependent on both the pH value of the solution and the morphology of the seed materials. Synthesized particles have regular morphologies and a uniform size distribution.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04b
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• pp.60-67
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• 1996

This paper was undertaken to analyze the morphology of wear debris on operating condition of lubricated machine surfaces. The lubricating wear test was carried out under different experimental conditions using the wear test device was made in our laboritory and wear testing spcimen of the pin on disk type was rubbed in paraffine series base oil, by varying specimen, applied load, sliding distance. The four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) to describe morphology of wear debris have been developed and are outlined in the paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology for machine condition monitoring.

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2002.01a
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• pp.21-21
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• 2002

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2002.08a
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• pp.83-83
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• 2002

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.600-603
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• 1997

Spherical, submicrometer particles of barium-titanyl oxalate were homogeneously precipitated by thermal decomposition of diethyl oxalate in acidic aqueous solutions. The rates of oxalate ion generations, determined by various combinations of temperature and initial concentration of diethyl oxalate had a very important effect on the particle size distribution. Monosized, bimodal, or broad unimodal powders were obtained under certain combinations of experimental variables.

• Corrosion Science and Technology
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• v.13 no.4
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• pp.130-138
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• 2014

Wall thinning can be classified into three types: flow-accelerated corrosion, cavitation erosion and solid particle erosion. This article presents a study of solid particle erosion, which frequently causes damages to power plants' pipe system. Unlike previous studies, this study uses a mechanism to make solid particles in a fluid flow collide with pipe materials in underwater condition. Experiment is conducted in three cases of velocity according to solid-water ratio using the three types of the materials of A106B, SS400, and A6061. The experiments were performed for 30 days, and the surface morphology and hardness of the materials were examined for every 7 days. Based on the velocity change of the solid particles in a fluid flow, the surface changes, the change in the amount of erosion, the erosion rate and the variation in the hardness of carbon steel and aluminum family pipe materials can all be determined. In addition, factor-based erosion rates are verified and a wall-thinning relation function is suggested for the pipe materials.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.9
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• pp.1139-1150
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• 1999

The evolution of silica aggregate particles in coflow diffusion flames has been studied experimentally using light scattering and thermophoretic sampling techniques. The measurements of scattering cross section from $90^{\circ}$ light scattering have been utilized to calculate the aggregate number density and volume fraction using with combination of measuring the particle size and morphology through the localized sampling and a TEM image analysis. Aggregate or particle number densities and volume fractions were calculated using Rayleigh-Debye-Gans and Mie theory for fractal aggregates and spherical particles, respectively. Of particular interests are the effects of flame temperature on the evolution of silica aggregate particles. As the flow rate of $H_2$ increases, the primary particle diameters of silica aggregates have been first decreased, but, further increase of $H_2$ flow rate causes the diameter of primary particles to increase and for sufficiently larger flow rates, the fractal aggregates finally become spherical particles. The variation of primary particle size along the upward jet centerline and the effect of burner configuration have also been studied.

• Fashion & Textile Research Journal
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• v.6 no.5
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• pp.667-672
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• 2004

Poly(ethylene terephthalate) (PET) fabrics were treated with a silica particle and phosphate flame retardant to determine the optimum process condition of the digital textile printing(DTP) media. The treating conditions for the study were 6 conditions, from F1 to F6, in which F3, F4 and F5 were treated with mixture of both silica particle and phosphate compound in process of pad, dry and cure fixation. F6 was treated with phosphate compound only and silica particle coating successively. Xanthan gum was used to control the migration of liquid phosphate compound onto PET fabrics. The change in surface morphology of fabrics treated with silica particle and phosphate compound was observed by SEM and flame retardance was evaluated by limiting oxygen index(LOI). It was observed that F6 was the excellent flame retardance and low bleeding in printing, Collectively, the printing characteristics of silica to cyan, magenta, yellow and black ink and flame retardance of fabrics finished with phosphate compound were identified in this study.

• Korean Journal of Materials Research
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• v.15 no.11
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• pp.717-721
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• 2005

Silica powders were synthesized using emulsion solution containing water, nonionic surfactant of Triton N-57, and cyclohexane. Silica powders were prepared at low cost using inexpensive starting material of sodium silicate and ammonium sulfate. Morphology, size and size distribution were observed and determined using SEM. The powder was identified as silica by FT-IR and XRD analysis. Particle size and size distributions were affected by concentration of reactants, reaction time, and concentration of surfactant. Particle size were increased with increasing concentration of reactants and particles became dense with increasing reaction time. As R value increased, tile particle size was increased, reached a certain value and then decreased again. The silica powders synthesized under optimum condition were spherical in shape, $0.8{\mu}m$ in average particle size, narrow in particles size distribution, and well dispersed.