• Journal of Biosystems Engineering
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• v.37 no.2
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• pp.90-99
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• 2012

Purpose: This study was conducted to investigate the optimal sorting factors in establishing an efficient sorting technology for brown rice. Methods: The brown rice varieties used in this study were Il Pum, Chu Cheong, Dong Jin, Un Gwang, Nam Pyeong, and Dae An. These were classified into whole grain, unriped grain, and green dead rice. The shape factors were analyzed based on length, width and thickness of the grains. Results: The results revealed that the maximum length among whole grain, unriped grain, and green dead rice was observed in Dae An variety while Chu Cheong variety showed the minimum. Further more, Il Pum brown rice showed the maximum width while Dong Jin variety showed the minimum. In the case of thickness, the maximum was observed in Un Gwang variety and that of the minimum among Nam Pyeong variety for both whole grain and unriped grain. Conclusions: The length and width can be used as determinants in sorting factors of whole grain and green dead rice, and the thickness can be considered as optimum sorting factor of whole grain and unriped grain.

• Journal of the Korean Society for Heat Treatment
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• v.4 no.4
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• pp.34-43
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• 1991

A small amount of misch metal and/or Zr was added as a dopant to 70.5wt----Cu-26wt----Zn-3.5wt----Al shape memory alloy in order to study the effect of grain refinement and heat treatments on the transformation behavior, stabilization of martensite, and shape memory ability. It was found that the addition of misch metal and Zr was very effective for reducing the grain size. The fracture mode has been changed from intergranular brittle fracture to ductile fracture with void formation and coalescence by the addition of misch metal and Zr. Aging of the ${\beta}$-phase decreases the $M_s$ temperature, but that of the martensite phase increases the $A_s$ temperature. The hysteresis of transformation temperature ${\Delta}T(A_s-M_s)$ has an increasing tendancy by grain refinement. The crystal structure of martensite was identified as monoclinic structure. As the grain size decreased, martensite stabilization more easily occured and the shape, memory ability has been reduced by the grain size refined.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.357-364
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• 2010

In a previous study, we mapped 12 QTLs for 1,000 grain weight (TGW) in the 172 $BC_2F_2$ lines derived from a cross between Oryza sativa ssp. Japonica cv. Hwaseongbyeo and O. rufipogon. These QTLs explained 5.4 - 11.4% of the phenotypic variance for TGW. Marker-aided selection combined with backcrosses was employed to develop QTL-NILs for each QTL. $BC_2F_2$ lines with each target QTL were backcrossed to Hwaseongbyeo twice and then allowed to self to produce $BC_4F_5$ populations. SSR markers linked to TGW were employed to select QTL-NILs with the respective target QTL. Six QTL-NILs with the recurrent parent, Hwaseongbyeo were evaluated for nine traits for three years from 2007 and 2009. Differences were observed between each of the 6 QTL-NILs and Hwaseongbyeo in TGW. In addition to TGW, these QTL-NILs displayed differences in other agronomic traits possibly indicating a tight linkage of genes controlling these traits. The direction of the QTL for TGW in 6 QTL-NILs was consistent as in the $BC_2F_2$ lines from the same cross. Difference in TGW between each of the QTL-NILs and Hwaseongbyeo was associated with the difference in one or two grain shape traits; grain length, grain width, and grain thickness. SSR markers linked to the QTL for TGW will facilitate selection of the grain shape character in a breeding program to diversify grain shape and provide the foundation for map-based gene isolation. Also, the QTL-NILs developed in this report and the progenies from crosses between the QTL-NILs will be useful in clarifying epistatic interactions among QTLs for TGW.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.102-105
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• 2003

The purpose of this study is to examine the influence of the flowability and the compressive strength of concrete after the improving of grain shape of the coarse aggregate and fine aggregate fineness modulus. According to the experimental results, the coarse aggregate after improvement of grain shape it lead to be down by 6% fine aggregate ratio, from 47% to 41%. The 0.5% increase of fine aggregate fineness modulus lead to 3% increase of concrete slump, and 1% reduction of concrete air content. While compressive strength on fine aggregate fineness modulus, it was increased until fineness modulus 3.0, but after it reached by 3.5 it was decreased. The compressive strength of the coarse aggregate after improving the grain shape was decreased by 6% due to loss of the adhesion of cement paste.

• Korean Journal of Materials Research
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• v.32 no.10
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• pp.414-418
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• 2022

Magnesium alloy is the lightest practical metal. It has excellent specific strength and recyclability as well as abundant reserves, and is expected to be a next-generation structural metal material following aluminum alloy. This paper investigated the possibility of thin plate fabrication by applying a overheating treatment to the melt drag method, and investigating the surface shape of the thin plate, grain size, grain size distribution, and Vickers hardness. When the overheating treatment was applied to magnesium alloy, the grains were refined, so it is expected that further refinement of grains can be realized if the overheating treatment is applied to the melt drag method. By applying overheating treatment, it was possible to fabricate a thin plate of magnesium alloy using the melt drag method, and a microstructure with a minimum grain size of around 12 ㎛ was obtained. As the overheating treatment temperature increased, void defects increased on the roll surface of the thin plate, and holding time had no effect on the surface shape of the thin plate. The fabricated thin plate showed uniform grain size distribution. When the holding times were 0 and 30 min, the grain size was refined, and the effect of the holding time became smaller as the overheating treatment temperature increased. As the overheating temperature becomes higher, the grain size becomes finer, and the finer the grain size is, the higher the Vickers hardness.

• Journal of The Geomorphological Association of Korea
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• v.27 no.2
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• pp.19-28
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• 2020

Grain size analysis is the most basic procedure for identifying the origin, transport and sedimentation processes of sediments, and is widely used in geomorphology and sedimentology. Traditionally, grain size was determined by a sieve-pippette method, but the use of automated analyzers is increasing in recent years. These analyzers have many advantages over traditional techniques, but the measurement results are not always the same. It is still difficult to solve the pretreatment problem such as incomplete diffusion and residual organic matter, and inappropriate results may be obtained. This study compared image-based grain size analysis and sieve analysis to verify its statistical reliability, and conducted experiments to enhance the measurement accuracy using shape parameters. The results showed that the image-based analysis overestimated the grain size of sand dunes by about 7% compared to the sieve analysis, but the two measurements were not statistically different. In addition, by using shape parameters, such as aspect ratio, sphericity, and convexity, improved statistics were obtained compared to the original data. Using the morphological properties of the individual grains is a complementary method to the incomplete pretreatment of the grain size analysis process, and at the same time, it will contribute to improving the accuracy and reliability of the results.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.25-30
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• 1988

Seven rice varieties and $42F_1$ hybrids of $7{\times}7$ diallel cross were used in genetic analysis for grain size, weight and shape. Effects of average heterosis for grain length and shape showed significantly negative values. GCA, SCA and RCA variances were significant for all characters and also additive variance was more important than dominance variance for grain length, width, thickness and weight. GCA effects of BG 2 and Arborio were highly positive for grain size and weight, and those of BG 2 and Nagdongbyeo were highly negative for grain shape. Partial dominance was observed for all characters. The direction of dominance was negative for grain length, width and shape, and ambidirections for grain thickness and weight. The effective gene number was two for grain length and shape. Both narrow and broad sense heritability were high in all characters.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.3
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• pp.127-131
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• 2001

The effect of grain shape on the grain growth behavior of oxide system was investigated as afunction of liquid content during liquid phase sintering. As a model system, the solid grains of $Al_{2}O_{3}$ and MgO were selected during liquid phase sintering, i.e. faceted shape of $Al_{2}O_{3}$ in $CaAl_{2}Si_{2}O_{8}$ liquid phase and spherical shape of MgO in $CaMgSiO_{4}$ liquid phase. The average grain size of MgO with spherical shape was decreased with increasing the liquid phase content, whereas that of $Al_{2}O_{3}$ with faceted shape was independent of liquid phase content. In the case of $Al_{2}O_{3}$ grains with faceted shape, which interfaces are expected to be atomically flat, are likely to grow by the interfacial reaction controled process. Whereas, in the case of MgO grains with spherical shape, which interface are expected to be atomically rough, are likely to grow by the diffusion controlled process.

• Journal of Powder Materials
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• v.29 no.2
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• pp.110-117
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• 2022

The grain growth behavior in the (1-x)K_0.5Na_0.5NbO₃-xCaZrO₃ (KNNCZ-x) system is studied as a function of the amount of CZ and grain shape. The (1-x)K_0.5Na_0.5NbO₃-xCaZrO₃ (KNNCZ-x) powders are synthesized using a conventional solid-state reaction method. A single orthorhombic phase is observed at x = 0 - 0.03. However, rhombohedral and orthorhombic phases are observed at x = 0.05. The grain growth behavior changes from abnormal grain growth to the suppression of grain growth as the amount of CaZrO₃ (CZ) increases. With increasing CZ content, grains become more faceted, and the step-free energy increases. Therefore, the critical growth driving force increases. The grain size distribution broadens with increasing sintering time in KNNCZ-0.05. As a result, some large grains with a driving force larger than the critical driving force for growth exhibit abnormal grain growth behavior during sintering. Therefore, CZ changes the grain growth behavior and microstructure of KNN. Grain growth at the faceted interface of the KNNCZ system occurs via two-dimensional nucleation and growth.

• Journal of the Korean Graphic Arts Communication Society
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• v.12 no.1
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• pp.43-55
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• 1994

To investigate relations between Grain-shape of plate and Dot-Gain in the lithography, Printing plates were made by Mechanical Grain, Brush Grain and Electrolytic Grain method.Fine multi-grain by electrolytic method of them resulted in less Dot-grain on the paper, more damping water on the none image part of printing plate.