• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1472-1479
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• 2002

In order to improve automotive fuel economy, vehicle weight should be reduced. Achieving significant weight reductions will normally require reducing the panel thickness or using alternative materials such as aluminum alloy sheet. These changes will affect the dent resistance of the panel. In this study, the correlation between panel size, curvature, thickness, material properties and dent resistance is investigated. A parametric approach is adopted, utilizing a "design software" tool incorporating empirical equations to predict denting and panel stiffness for simplified panels. The most effective period to optimize an automotive body panel is early in its development. The developed design program can be used to minimize panel thickness or compare different materials, while maintaining adequate panel performance.

• Journal of Mechanical Science and Technology
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• v.16 no.12
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• pp.1673-1686
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• 2002

In the interest of improved automotive fuel economy, one solution is reducing vehicle weight. Achieving significant weight reductions will normally require reducing the panel thickness or using alternative materials such as aluminum alloy sheet. These changes will affect the dent resistance of the panel. In this study, the correlation between panel size, curvature, thickness, material properties and dent resistance is investigated. A parametric approach is adopted, utilizing a "design software" tool incorporating empirical equations to predict denting and panel stiffness for simplified panels. The most effective time to optimize an automotive body panel is early in its development. The developed design program can be used to minimize panel thickness or compare different materials, while maintaining adequate panel performance.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.177-182
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• 1999

This research was carried out in a farm situated in Malkara District of Tekirdag Province (Turkey) in 1994-95, and the effect of genotype and environmental conditions on some characters and variations of these characters in terms of silage yield in 8 dent corn varieties were determined. The results of this research showed that leaf weight, stem diameter, and silage yield had a low broad sense heritability while the number of leaves per plant had a high heritability. Yield performance of varieties varied to a significant degree because of variations in rainfall rate during the growing periods. Leaf number, silage yield, leaf weight, stem diameter, plant height and ear weight varied between 13.33-17.33 number, 8,443-11,114 ton/hec, 152.8-244.2 g, 2,615-2,965 cm, 216.5-252.5 g and 176.2-285.8 g, respectively.

• Advances in Computational Design
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• v.1 no.4
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• pp.345-356
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• 2016

Notwithstanding a considerable body of references in the literature on the buckling response of conical shell structures, it seems imperative to provide further insight on the buckling response of locally imperfect steel cones. This paper contains different simulations including non-linear FE analysis and discusses the influence of dent imperfection on the buckling load of these structures subject to external pressure. Data of the present work are evaluated against available experimental results, codes and recommendations and the effect of the local damages is exhaustively set forth. It is also found that the employed FE program can reliably predict the structural response of locally damaged conical shells.

• Steel and Composite Structures
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• v.19 no.6
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• pp.1355-1367
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• 2015

Steel conical shells have long been used in various parts of different structures. Sensitivity to the initial geometrical imperfection has been one of the most significant issues on the stability of these structures, which has made them highly vulnerable to the buckling. Most attention has been devoted to structures under normal fabrication related imperfections. Notwithstanding, the challenges of large local imperfections - presented herein as dent-shaped imperfections - have not been a focus yet for these structures. This study aims to provide experimental data on the effect of such imperfections on the buckling capacity of these shells under axial compression. The results show changes in the buckling mode and the capacity for such damaged thin specimens as is outlined in this paper, with an average overall capacity reduction of 11%.

• The Journal of Korean Academy of Prosthodontics
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• v.24 no.1
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• pp.27-31
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• 1986

The purpose of this study was to discover the elemental change of the tracemetal surface of the precious porcelain alloy. The alloy was degudent H. For this purpose, the following experiment was made the analysis of the elemental change of the surface precious gold porcelain alloy were done by EDXA, and EPMA. The result is as follows, The Indium was transported to the alloy surface and its segregation to within a few microns of the porcelain-metal interface.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.225-232
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• 1992

The purpose of this study was to compare the bond strength of the glass ionomer luting cements after the functional loads were applied to the crowns respectively 10 min, 30 min, 1 hr, 24 hrs later after mixing of cements. The conventional (GC Fuji I; GC Int. Co., Japan), water hardening type (Ketac Cem; ESPE, W. Germany) glass ionomer luting cement and C-dent ZPC (Confi-Dental Products Co., U.S.A.) as a control were used. The results of this study were obtained as follows: 1. In the bond strength of GC Fuji I, 24 hr-group was highest and there were no statistically significant differences among 10 min-, 30 min- and 1 hr- groups. 2. l3 the bond strength of Ketac Cem and C-dent ZPC, there was no statistically significant differences among 10 min-, 30 min-, 1 hr- and 24 hr-groups respectively. 3. Comparing the bond strength among cements in 10 min-, 30 min-groups respectively, GC Fuji I was lowest and there was no statistically significant difference between Ketac Cem and C-dent ZPC. 4. The bond strengths between GC Fuji I and Ketac Cem were not significantly different in 1 hr-, 24 hr-group. 5. The bond strengths among 3 types of cements were not significantly different in 24 hr-groups.

• Tribology and Lubricants
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• v.37 no.4
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• pp.144-150
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• 2021

The most cost-effective method of reducing abrasive wear in mechanical parts is increasing their hardness with thin hard coatings. In practice, the composite hardness of the coated substrate is more important than that of the substrate or coating. After full unloading of the load applied to an indenter, its indentation hardness evaluated based on the dent created on the test piece was almost dependent on plastic deformation of the substrate. Following the first part of this study, which proposes a new Brinell hardness test method for a coated surface, the remainder of the study is focused on practical application of the method. Indentation analyses of a rigid sphere and elastic-perfect plastic materials were performed using finite element analysis software. The maximum principal stress and plastic strain distributions as well as the dent shapes according to the substrate yield stress and coating thickness were compared. The substrate yield stress had a significant effect on the dent size, which in turn determines the Brinell hardness. In particular, plastic deformation of the substrate produced dents regardless of the state of the coating layer. The hardness increase by coating behaved differently depending on the substrate yield stress, coating thickness, and indentation load. These results are expected to be useful when evaluating the composite hardness values of various coated friction surfaces.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.224-232
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• 2019

Objective: Apart from various climatic differences, corn harvest stage and varieties are two major factors that can influence the yield and quality of corn silage in the tropics. A study was conducted to determine the optimum harvest stage of four corn varieties for silage production in Malaysia. Methods: Corn was harvested at four growth stages; silking, milk, dough, and dent stages from four varieties; Sweet Corn hybrid 926, Suwan, breeding test line (BTL) 1 and BTL 2. Using a split plot design, the treatments were then analysed based on the plant growth performance, yield, nutritive and feeding values followed by a financial feasibility study for potential commercialization. Results: Significant differences and interactions were detected across the parameters suggesting varying responses among the varieties towards the harvest stages. Sweet Corn was best harvested early in the dough stage due to high dry matter (DM) yield, digestible nutrient, and energy content with low fibre portion. Suwan was recommended to be harvested at the dent stage when it gave the highest DM yield with optimum digestible nutrient and energy content with low acid detergent fibre. BTL 1 and BTL 2 varieties can either be harvested at dough or dent stages as the crude protein, crude fibre, DM yield, DM content, digestible nutrient and energy were not significantly different at either stage. Further financial analysis showed that only Sweet Corn production was not financially feasible while Suwan had the best financial appraisal values among the grain varieties. Conclusion: In conclusion, only the grain varieties tested had the potential for silage making according to their optimum harvest stage but Suwan is highly recommended for commercialization as it was the most profitable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.425-431
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• 2006

In order to investigate the effects of ethylene on the seed development of three corn types (dent, sweet, and super sweet corns), aminoethoxyvinyl glycine (AVG) and silver thiosulfate (STS) and ethephon (2-chloroethylphosphonic acid, CEPA) were applied either on whole plants or shanks of ears at 9 and 21 days after silking. Ethylene production of developing super sweet corn seeds was much higher than those of sweet and dent corns. The cavity in the endosperm tissues of the super sweet corn started earlier and endosperm was collapsed more severely compared to those of sweet and dent corns. Ethylene production seemed to be related to the death of endosperm cells to form a cavity. Application of AVG and STS reduced ethylene production and delayed cavity formation in endosperm of super sweet corn seeds, while CEPA increased ethylene production and enhanced the time of cavity formation. AVG and STS increased 100-seed weight, while CEPA decreased.