• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.107.1-107.1
• /
• 2012

Because of beautiful glossy and color, the value of gold leverage is very high in Europe. For improve the quality of white gold, we performed heat treatment on 14K white gold alloys at various age-hardening conditions. Age-hardening behavior and the related phase transformation changes were studied to elucidate the hardening mechanism of 14K white gold alloys. For solid solution treatment [ST], casted 14K white gold alloy specimens were treated at high temperature ($750^{\circ}C$) during 30 minute, and the specimens dropped to water for quenching immediately. For Age-hardening treatment [AT], the specimens were treated at various temperatures ($250^{\circ}C{\sim}300^{\circ}C$). After the heat treatment, we observed increased hardness from 144 Hv to 214 Hv by Vicker's hardness tester. Variation of the grain size measured by optical microscopy (OM) and scanning electron microscopy (SEM) images. By electron probe micro-analysis (EPMA) mapping analysis, we investigated that irregular particles were changed uniformly. After heat treatment, 14K white gold alloys showed improved hardness and became uniformity of grain size by age-hardening treatment.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47
• /
• pp.95-106
• /
• 2002

Soybean is one of the most important sources of protein and oil in the world. Recently, emphasis has been laid on the chemical composition of soybean seeds for the processing soybean foods. Improvement of soybean components has been expected to improve food-processing quality for the processed soybean products such as soymilk and various edible ingredients as well as fur the traditional soyfoods. In Korea, soybean breeding research programmes have been focused on the quality of the products derived from soybean with yield stability, and some new modified soybean varieties haying good food-processing quality were developed recently. So the efforts of establishing standard and standardization of products in soybean are important. Three main categories should be considered in view of soybean seed quality; the marketing value such as grain size, shape, and appearance; the eating and processing value such as dehulled ratio, water absorption rate, and benny flavor; the nutritional value such as protein, lipid, and carbohydrate contents. And the new frontiers in research are looking at the functional nutrients in soybeans and how to improve them. In case marketing value, mainly the appearance is evaluated, therefore, each country has an application of standard related to quality. Each determination of standard class, heat-damaged kernels, splits, and soybeans of other colors is made on the basis of the grain when free from foreign materials. But processing value and nutritional value for standardization were not studied in detail till now. In addition, soybean has potential roles in the prevention and treatment of chronic diseases, most notably cancer, osteoporosis, and heart disease. The functional nutrients include a protease inhibitor, phytic acid, saponins, and isoflavones, etc.. It is believed that standardization of soybean quality should perform to overcome the difficulties, relatively high price of domestic soybean products has weakened the competitive power, in the market related to WTO. So, we should focus on further research into the evaluation and establishment of quality-standard in soybean.

• Korean journal of food and cookery science
• /
• v.32 no.5
• /
• pp.531-540
• /
• 2016

Purpose: To improve the cooking quality of brown rice, newly inbred soft rice cultivars were investigated. Methods: The physicochemical properties of brown rice flour and water absorption patterns and cooking characteristics of brown rice grain were compared to Ilmi white and brown rice. Results: General composition and total dietary fiber contents of five rices were significantly different with higher ash, protein, and total dietary fiber contents in soft brown rice than white rice. The hardness of raw rice grain was higher in Ilmi brown rice than in soft brown rice. The water absorption increased rapidly in 30 min of white rice and in 4-6 h of brown rices. The apparent amylose content of soft brown rice was lower than that of Ilmi rice. The initial pasting temperature and all viscosities were significantly different, but the trend was not similar. The textural properties of hardness and roughness were higher, but adhesiveness, cohesiveness, and stickiness were lower in Ilmi brown rice than white and soft brown rices. In sensory preference test, not only textural properties, hardness, adhesiveness, cohesiveness, stickiness, and roughness, but also color, glossiness, and roasted flavor were higher in soft brown rices. Especially soft brown rice B showed the best cooking quality among all rices. Conclusion: The results of the study suggested that soft brown rice is developed for cooking with high nutritional and functional quality.

• Solar Energy
• /
• v.17 no.4
• /
• pp.3-11
• /
• 1997

Because grain boundaries in polycrystalline silicon act as potential barriers and recombination centers for the photo-generated charge carriers, these defects degrade conversion effiency of solar cell. To reduce these effects of grain boundaries, we investigated various influencing factors such as thermal treatment, various grid pattern, selective wet etching for grain boundaries, buried contact metallization along grain boundaries, grid on metallic thin film. Pretreatment above $900^{\circ}C$ in $N_2$ atmosphere, gettering by $POCl_3$ and Al treatment for back surface field contributed to obtain a high quality poly-Si. To prevent carrier losses at the grain boundaries, we carried out surface treatment using Schimmel etchant. This etchant delineated grain boundaries of $10{\mu}m$ depth as well as surface texturing effect. A metal AI diffusion into grain boundaries on rear side reduced back surface recombination effects at grain boundaries. A combination of fine grid with finger spacing of 0.4mm and buried electrode along grain boundaries improved short circuit current density of solar cell. A ultra-thin Chromium layer of 20nm with transmittance of 80% reduced series resistance. This paper focused on the grain boundary effect for terrestrial applications of solar cells with low cost, large area, and high efficiency.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2002.05a
• /
• pp.58-62
• /
• 2002

The standard of crop quality is required to promote the consumption and produce the high quality products. It will contribute the stability for processing products and the marketability of crops. Upland crop quality is considered to the three categories; the marketing value such as grain size, shape and appearance; the eating and processing value such as milling rate, dehulled ratio and kernel hardness; the nutritional value such as protein, lipid and isoflavone content. Even though many characters were analyzed for crop quality, effective method of evaluation to enhance the control of quality was not performed till now. Therefore, in the future, research in upland crop quality should emphasize to establish the standard evaluation method.

• Corrosion Science and Technology
• /
• v.6 no.4
• /
• pp.193-197
• /
• 2007

It is well known that the development of Advanced High Strength Steels (AHSS) is very important for the automotive industry in order to improve fuel efficiency and the reduction of material costs. However, it is particularly difficult to improve the surface quality of AHSS because the high amount of Si, Al, Mn and Ti etc. in AHSS promote selective oxidation, resulting in surface defects. The reheating process in the hot strip mill would cause severe oxidation because it is carried out at elevated temperatures under aggressive environments. In this study a reheating furnace simulator was developed to investigate oxidation phenomena in the reheating process. The environmental gas for the reheating furnace was made by burning coke oven gas with air in the simulator. The air/fuel ratio is precisely controlled by MFC. Ti oxides are easily formed on grain boundaries and Mn and Si oxides are usually formed in inner grains near the steel surface with a small round shape.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.2
• /
• pp.73-78
• /
• 2000

This study was conducted for 2 years at Chinju region to establish suitable seeding rate and fertilizing levels of nitrogen, phosphorous and potassium in spring-sown Jinyangbori. Heading and maturing were delayed by increasing fertilizers, especially nitrogen. Number of spikes per were secured by much seeding and increased application of nitrogen. One thousand grain weight reduced with increasing fertilization at any seeding rate. Relatively high harvest indices were observed with 12-10-4 at 10kg. 10a$^{-l}$ seeds planted, followed by 6-10-8 at 15 kgㆍ 10a$^{-1}$, and 6-10-4kgㆍ 10a$^{-l}$ at 20kg ㆍ 10a$^{-l}$ of N-P-K fertilizing combinations, respectively. There was no distinct differences on yield for various seeding rates in spring-sown barley. When seeding rate increased up to 15kgㆍ10a$^{-1}$, the positive effect of fertilizers was recognized as the function of balanced-application. It was possible to recommend 10kgㆍ10a$^{-1}$ as seeding rate and 6-5-4(N-P-K)kgㆍ10a$^{-1}$ as fertilizing combination in spring-time seeding considering low input and sustainable agriculture. There was no significant difference of protein content in grain by seeding rate. Increase of nitrogen fertilizer enhanced protein content in grain.

• Korean Journal of Breeding Science
• /
• v.51 no.3
• /
• pp.222-233
• /
• 2019

'Haepum' is a bacterial blight-resistant, medium maturing rice cultivar with high grain quality. It was derived from a cross between 'Iksan493' (cultivar name 'Jinbaek') and the F₁ cross between 'Iksan495' ('Dacheong') and 'Iksan496' ('Jungmo1005'). Of these three cultivars, 'Jinbaek' is a bacterial blight-resistant mid-late maturing rice cultivar with high grain quality, 'Dacheong' is a mid-late maturing rice cultivar with multiple resistance to disease and insects, and 'Jungmo1005' is a mid-late maturing rice cultivar with lodging tolerance. To develop fixed lines, the anther culture method was applied to F₁ plants. The cultivar 'Haepum' was selected using the pedigree method, yield trials, and local adaptability tests. The heading date of 'Haepum' was August 11^th, three days earlier than that of 'Nampyeong' cultivar. Haepum' is a cultivar tolerant to lodging and it has short culms. Due to its low rate of viviparous germination, 'Haepum' could be useful for preventing pre-harvest sprouting in cultivation of medium maturing rice in the southern plain area of Korea. 'Haepum' carries two bacterial blight resistance genes (Xa3 and xa5), and in our study, it exhibited high-level and broad-spectrum resistance against bacterial blight, including K3a, the most virulent race in Korea. 'Haepum' is also resistant to the rice stripe virus and moderately resistant to rice blast. The yield of 'Haepum' was similar to that of 'Nampyeong'. 'Haepum' showed excellent grain appearance and good taste of cooked rice, and therefore it could contribute to the development of bacterial blight-resistant rice cultivars of improved quality. 'Haepum' would be suitable for cultivation in the southern plain area of Korea as well as in bacterial blight-prone areas. (Registration No. 6068)

• Korean Journal of Agricultural Science
• /
• v.43 no.3
• /
• pp.330-339
• /
• 2016

The effect of transplanting and harvest timing was evaluated for the production of high quality pigmented rice in the Yeongnam plain area. Rice was transplanted on June $2^{nd}$ and $14^{th}$ and harvested between 35 - 55 days after panicle heading at 5 - day intervals. Three black- and 3 red-pigmented rice cultivars (such as early cultivar : Josengheugchal, Jeogjinju; medium cultivar : Heugseol, Hongjinju; and mid-late cultivar : Sintoheugmi, Geongganghongmi) were studied. Yield components like spikelet number, ripened grain ratio, and 1,000 - grain weight of the black- and red-pigmented rice cultivars were similar for both the June 2 and June 14 transplantings but panicle number per $m^2$ was higher for the June 14 transplanting than for June 2. This contributed to a higher brown rice yield for the June 14 transplanting, by 6 - 19% for black-pigmented rice, and by 10 - 21% for red-pigmented rice than the yield for the June 2 transplanting. Total anthocyanin and polyphenol productions of the pigmented rice were also higher in the June 14 transplanting than that in the June 2 transplanting due to high brown rice yield. Based on the combined pigmented brown rice yield, we concluded that the optimal harvest timing would be 40 - 45 days after panicle heading (DAH) for the black-pigmented rice and 45 - 50 DAH for the red-pigmented rice. This study suggests that optimum transplanting and harvest timings play an important role for production of high quality pigmented rice in the Yeongnam plain area.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.6
• /
• pp.534-539
• /
• 2003

The yield and quality characteristics of three rice varieties(Seojinbyeo, Ilpumbyeo, and Chuchungbyeo) in reclaimed saline paddy field were investigated under different cultural practices, three transplanting times (May 15, May 30 and June 15) and four harvest times (40, 50, 60 and 70days after heading) in order to obtain basic information for the production of high quality rice. Brown rice yield of three rice varieties were significantly higher in early and medium than late season cultivation. The protein content of milled rice showed high interaction effect between transplanting time and harvest time. Palatability values of Seojinbyeo and Ilpumbyeo were significantly higher in late than medium season cultivation, but Chucheongbyeo did not show any difference in its palatability value by different transplanting time. The palatability values of three rice variety was the highest in the harvest at 40 days after heading. The grain yield of three rice varieties were higher in early and medium than late season cultivation, whereas palatability values of three rice varieties were significantly higher in the early and late season cultivation than medium season cultivation. The palatability value measured by rice taster showed a highly negative correlation(r=$0.43^{**}$) with cumulative air temperature during ripening period.