• Korean Journal of Materials Research
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• v.15 no.3
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• pp.161-165
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• 2005

We investigated selective dry etching of GaAs over AlGaAs and InGaP in high density planar inductively coupled $BCl_3/SF_6$ plasmas. The process parameters were ICP source power (0-500 W), RE chuck power (0-30W) and gas composition $(60-100\%\;BCl_3\;in\;BCl_3/SF_6)$. The process results were characterized in terms of etch rate, selectivities of GaAs over AlGaAs and InGaP, surface morphology, surface roughness and residues after etching. $BCl_3/SF_6$ selective etching of GaAs showed quite good results in this study. Selectivities of GaAs $(GaAs:AlGaAs\~36:1,\;GaAs:InGaP\~45:1)$ were superior at $18BCl_3/2SF_6$, 20 W RF chuck power, 300 W ICP source power and 7.5 mTorr. Addition of $(5-15\%)SF_6\;to\;BCl_3$ produced relatively high selectivities of GaAs over AlGaAs and InGaP during etching due to decrease of etch rates of AlGaAs and InGaP (boiling points of etch products: $AlF_3\~1300^{\circ}C,\;InF_3>1200^{\circ}C$ at atmosphere) at the condition. SEM and AFM data showed slightly sloped sidewall and somewhat rough surface$(RMS\~9nm)$. XPS study on the surface of processed GaAs proved a very clean surface after dry etching. It shows that planar inductively coupled $BCl_3/SF_6$ plasmas could be a good candidate for selective dry etching of GaAs over AlGaAs and InGaP.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.17-20
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• 2005

Natural products has been occasionally used in place of growth regulators to control lateral root formation and growth of soybean sprouts. The study was done to measure the effects of treatment concentration of hard rubber tree (Eucommia ulmoides Oliver) leaf extract on lateral root formation, growth and morphological characters of the sprouts. Seeds of three cultivars, Pungsannamulkong, Sowonkong and Junjery, were imbibed for 5 hours into water, its 5 and 10% solutions immediately before 6 day culture. The cultured sprouts were classified into 4 categories to calculate their composition rates on the base of hypocotyl lengths; >7 cm (A),4 to 7 cm (B),<4 cm (C) and not germinated (D), and their morphological characters, fresh and dry weights were measured. Rate of A was decreased with increased concentrations, while that of C showed reverse result compared to A. Regardless of concentrations, the former rate was less in cv. Junjery than in cv. Pungsannamulkong and Sowonkong than in cv. Junjery although the latter rate was truly opposite to the former one. In 10% treatment concentration, lateral roots were less formed in cv. Junjery although nearly formed in cv. Pungsannamulkong and Sowonkong. In all the 3 cultivars, lateral roots per sprouts were decreased with increased treatment concentration. shorter and thicker sprout was observed in cv. Junjery than in the other cultivars, and in increased concentrations compared to relatively lower ones. Total fresh weight was the greatest in cv. Sowonkong due to mainly increment of its hypocotyl, but was reduced with increased concentration due to mainly decrement of hypocotyl in all the cultivars.

• Archives of design research
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• v.2 no.1
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• pp.43-62
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• 1989

The luxury is the expression of human being's ornament instinct. In this study, in order to grasp the moulding system of the Korean's personal ornaments, the process of luxury prohibition was reviewed to search for to which direction the ornaments developed in the frame of the prohibited style connected closely to the character of the personal ornaments. The proiod was fixed from the old society to the late Chosun dynasty era. The beginning of the luxury in Korea seems to be the start of the luxury burial at the time of funeral in the age of Koguryo., In the era of Koguryo, 10th year of King Dongmyung (B. C. 28), in the era of Baekje, 27th year of King Koi(260), the prohibition of dress regulation and the style of dress were conducted. The prohibition of personal ornaments in Silla was started from King Bup:Heung, and in the 9th year of King Heung-Duk, the prohibition was conducted in order to correct the luxury of the nobles and set up the social discipline. In the 11 th of King Il-Sung-Ni-Sa-Kum, the use of gold, silver and jade was prohibited in the civilian circles. The prohibition of Silla was succeeded to Koryo era, and in the 7th year of King Kwangjong(956), the system of Baekgwan Gongbok(uniform for government officials) was set up, and the system of Sasek Gongbok(four color official uniform) was set up in the 11 th year of the same King, and the prohibition of the personal ornaments such as crown and band is considred to have been conducted. The prohibition of gold and silver was conducted in the first year of King Sungjong(982), and in the 4th year of King Chungryul(l260), the order of wearing the dress and hat in accordance with the Yusan dynasty and the Mongolian customs were widely circulated in the royal court and vivilian circles. The strong influence of Mongolia made the taste of the traditional personal ornaments laste. The personal ornaments were used for the nobles until the age of the Unified Sillar but even the common people could use them in case they were rich, and such a circumstances made the use of foreign goods inflated. The prohibition of Koryo era was aimed at the prohibition of the foreign goods of luxury, and the classification of the social status.In the age of Chosun Dynasty, the production of gold and silver was feeble indeed but the oute reason of the prohibition was to eradicate the luxurious tendency, elevate the custom of eradicate the luxurious tendency, elevate the custom of thrift, and moreover, the gold, silver and jade were no the products of Korea and the prohibition was conducted but the true reason was afor the tribute tt China and the classification of status. The prohibition of Chosun dynasty was conducted first in the June of the 3rd year of King Taejo The major contents of prohibition was no use of gold, silver and jade, coral, agate, amber, etc. of th, wives of the Dang-Sang-Kwan (Court Nobleman) or their sons and daughters, and the same pheno menon was common even at the time of marriage. The people engaged in the secret trade there of wert beheaded. The personal ornaments in the prohibition were the pendent trinket, Binyo (crossbar) ceremonial ornamental hat, ring, earring, ornamental knife, hat string, hat ornament, belt, etc. Thl luxurious marriage expenses out of the luxury was severe, and lose of the marriageable age because 0 non-preparing the marriage goods was the national evil. The prohibition oC luxury was hard to bt kept to the nobles or rich people, the same as old days and present days. The prohibition of th{ luxury and personal ornaments of Korea had nothing to do with the commons, and it was limited tc the nobles and rich people. The prohibition was aimed to cultivating the custom of frugality by eradicating the luxurious atmosphere, but it was chiefly due to the tribute to the China and tht discrimination of the. status. We can say that the recent personal ornament was the flower of handi craft industry bloomed in the prohibition and regulation.

• Journal of Life Science
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• v.27 no.10
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• pp.1176-1184
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• 2017

The contents of inorganic and functional components in the organic Cheongyang pepper, tomato, and strawberry were compared with those of the conventional produce. The analyzed functional components were total phenol, total flavonoid, vitamin C, vitamin E, ${\beta}-carotene$, and capsaicin in Cheongyang peppers; lycopene in tomatoes; and anthocyanin in strawberries. The analyzed inorganic components were total N, Zn, Fe, Ca, Mg, Na, K, and P. The total phenol contents of Cheongyang peppers and tomatoes were 14% and 30% higher, respectively, in the organic vegetables than the conventional ones, whereas strawberries had 13% higher components than the conventional ones. The total flavonoid contents of the Cheongyang peppers and tomatoes were 11% and 29% higher, respectively, than in the conventional produce, but those of the strawberries were 100% higher than in conventional strawberries. Vitamins were mostly higher in organic cultivation products, but there was no significant difference. The ${\beta}-carotene$ content was 22% higher in organic tomatoes, but conventional strawberries and peppers had more ${\beta}-carotene$ than the organic types did. The contents of capsaicin and lycopene were no different between the various cultivations, while anthocyanin was higher in the conventional cultivation. Analysis of inorganic components did not differ between cultivation methods for peppers and tomatoes, and the total N, K, and P contents were higher by 20-28% in the conventional cultivation. The contents of K, Ca, Mg, and P were 16-29% higher in the conventional cultivation of strawberries. Depending on the crops, there were many syntheses of functional components in the organic cultivation. This was thought to be due to nutrients and environmental stress.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.226-232
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• 2019

The biological wastewater treatment is more eco-friendly and can be used effectively in wastewater for a variety of purposes than that of the conventional treatment. In particular, the wastewater treatment using microalgae in biological treatment processes has attracted great attention due to its ability to remove economically nutrients from wastewater and have many advantages as a renewable energy source. This study was investigated to establish the optimal growth conditions for microalga Scenedesmus obliquus. Additionally, the removal efficiencies of nutrients (N, P) and heavy metals (Cu, Zn) from the synthetic wastewater were evaluated. As a results, the optimal growth conditions were established at $28^{\circ}C$, pH 7, and light and dark cycle of 14 : 10 h. In the evaluation of nutrient removal efficiencies at each concentrations of 500, 1,000, 5,000, and 10,000 mg/L, the removal rates were 17.6~70% N and 8.4~34% P in the single treatment and 12.0~58.0% N and 3.0~40.3% P in the binary mixture treatment. In addition, the evaluation of heavy metal removal efficiencies at each concentrations of 10, 30 and 50 mg/L, the removal rates were 13.7~40.3% Cu and 10.0~30.0% Zn in the single treatment and 16.0~40.0% Cu and 12.0~20.0% Zn in the binary mixture treatment. Based on the results of the study, it appears that Scenedesmus obliquus can be used for the removal of nutrients and heavy metals from the swine wastewater.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.119-127
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• 2016

The current disinfection method of vehicles being applied in South Korea has various shortcomings. So, the epidemic has generated continuously at livestock farms. It is very important to develop an effective disinfection system for reduction of the epidemic. And various basic data is required for this development. Therefore, this study was performed to identify the nozzle type and proper discharge pressure of sprayers. The experiment was conducted from January 10, 2012 until February 28, 2012. All the performance measurement experiments were repeated five times. The subjects of experiment were the A, B and C company's products. The sprayed capacity, angle of spray and the covering area ratio were measured for each product. As a result, the sprayed capacity, angle of spray and the covering area ratio were increased as the discharge pressure of the sprayer was increased. In conclusion, the conical shaped of the nozzle is considered more appropriate than V-shaped, and the proper discharge pressure is expected to be at least 20kg/㎠.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.158-171
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• 2023

Pottery filled with organic materials was excavated from the G-2 building site of Yongjangseong Fortress, Jingo, a relic of the Goryeo Dynasty. In this study, the characteristics of organic material were confirmed by a scientific analysis of organic material in pottery found at the palace in Yongjangseong, Jindo. In addition, it was intended to review the analysis method to identify the natural resin and to secure characteristic components(biomarkers) for each natural resin and use them as basic data in the future. The organic materials in the pottery were analyzed using attenuated total reflectance Fourier-transformed infrared spectroscopy(ATR-FTIR) and gas chromatography mass spectrometry(GC-MS). The infrared spectral characteristics were estimated to be natural resin, and biomarkers of organic materials were identified as sesquiterpene-based compounds(C₁₅H₂₄, MW 204) and derivatives. The lacquer(T.vemicifluum) is composed mainly of alkenes, alkanes, and catechol. Pine resin(P.densiflora), on the other hand, is primarily composed of diterpenoid(abietic acid, pimaric acid) and Whangchil(yellow lacquer) is identified to have sesquiterpenes(such as selinene, muurolene, calamenene) as its main components. So, the organic material in the pottery can be identified as Whangchil by comparing their compounds with modern resin materials from Dendropanax. morbifera that correspond with the results. Whangchil, which is exuded from the Dendropanax. morbifera, has been used as a natural coating materials since ancient times, and it has been confirmed that the characteristic components are well preserved even 700 years later. It can be assumed that the interior Whangchil was stored not for use as a coating, but rather for ritual purposes when the building was constructed, because the pottery was found near the cornerstone. Furthermore, based on simplified sample preparation using pyrolysis-gas chromatography mass spectrometry(Py-GC-MS), the thermal decomposition products were found to be similar to the characteristic components, suggesting that this method can be applied to the identification of natural resins used in historic artifacts.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.613-626
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• 2010

Coming with the well-being era, consumer's demand for safe agricultural products is increasing. It is urgent to develop an environment-friendly pear production system. Accordingly, this study was conducted to develop an environment-friendly pear production system by using several environment-friendly agricultural materials which is known to be effective in agricultural production. In the effects of environment-friendly agricultural materials on the soil chemical characteristics in pear orchard, the content of total carbon, organic matter, Ca and Mg increased a little respectively compared with those of 2008, and 2nd treatment showed the highest EC and Mg content in the soil among treatments. The content of leaf N, P and Ca in 2009 decreased compared with those of 2008, while Mg content showed no difference between 2008 and 2009 years. Average pear weight in 2009 was 31g higher than that of 2008 (682g) and 2nd treatment showed the highest pear weight (738g) among treatments. The average sugar content was higher in 2009 (12.6$^{\circ}Bx$) compared with that of 2008 (12.2$^{\circ}Bx$) and the plot of 2nd treatment highest sugar content (12.6$^{\circ}Bx$) among treatments. There were no difference in hunter value of L among treatments, but hunter value of a showed higher 1.62 in 2009 than that of 2008 (3.73). The highest of gumminess and cohesiveness of fruits were obtained from 1st treatment and adhesiveness and chewiness of fruits were obtained from 3rd and 1st treatment respectively. Firmness of fruit increased a little in 2009 compared with that of 2008, while the highest firmness was obtained from 3rd treatment with 1.63kg/5mm$\oint$ among treatments. Phosphate content in the peel of 'Niitaka' pear of fruit skin in 2009 (0.97g/kg) showed 0.06g/kg more content than that of 2008 (0.91g/kg), while the highest content was obtained from 3rd treatment (1.15g/kg). Potassium content in the peel of 'Niitaka' pear in 2009 was 8.20g/kg, which is 0.06g/kg more content than that of 2008 (7.82g/kg) and the highest content was obtained from 1st treatment (8.34g/kg) among treatments. The highest nitrogen content in the flesh of 'Niitaka' pear was obtained from 3rd treatment (4.32mg/g), while it was the lowest in control plot (3.10mg/g). Phosphate content in the flesh of 'Niitaka' pear in 2009 (8.20g/kg) showed 0.06g/kg more content than that of 2008 (7.82g/kg), while the highest content was obtained from 1st treatment (8.34g/kg). There were no difference of the potassium content in the fruit peel of 'Niitaka' pear between years, but 1st treatment showed the highest content (11.81g/kg) among treatments, while the lowest was obtained from the control plot (10.83g/kg).

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.565-571
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• 2006

The purpose of this study was to investigate the regional differences in anthropometric measurement, dietary behavior and nutrient intake among the nation-wide college students participating in a nutritional education program via internet. The subjects were 1614 college students (male: 752, female: 862) and divided into 4 regional groups. A cross-sectional survey was conducted using a self administered questionnaire, and the data were collected via internet or by mail. The nutrient intake data collected from food record were analyzed by the Computer Aided Nutritional Analysis Program. Data were analyzed by SPSS 10.0 program. Average age of male and female college students were 23.6 years and 21.0 years, respectively. Most of the male and female college students had poor eating habits, such as unbalanced meals and skipping meals. In particular, more than 60% of the male college students in Chungcheong and Gyeongsang areas had irregularity of meal time. Female students in Seoul and Incheon areas showed significantly higher consumption frequency of yellow and green leafy vegetables compared to Chungcheong and Gyeongsang areas. Female students in Seoul, Incheon and Chungcheong areas showed significantly higher consumption frequency of milk and milk products compared to Gyeongsang area. Calorie, vitamin A, calcium and iron intakes of the male students and calorie, vitamin A, vitamin $B_2$, niacin and calcium intakes of female students were lower than the Korean RDA. Female students in Incheon area showed significantly higher vitamin C and iron intakes compared to the other areas. These results provide a nation-wide information on dietary behavior and nutrient intake among Korean college students.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.107-114
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• 2002

Rice straw silage added with apple pomace in different ratios were mixed with commercial concentrates and fed to Korean native goats in comparison to the corn silage mixed with the same content of commercial concentrates in whole diet as that of apple pomace added rice straw silage (rice straw : apple pomace = 100:0, 80:20, 60:40, 40:60). Dry matter intake, digestibilities of nutrients and nitrogen retention were investigated for the possibilities of application of agricultural by-products for the diets of Korean native goats. Crude protein contents of rice straw silage added with apple pomace were 6.3~7.3% and the contents of ADF, NDF and crude ash were highest in 100% rice straw mixed ratio (A) as 39.4, 61.6 and 8.9% respectively. Those were lower in corn silage (E) as 30.3, 53.4 and 4.9% respectively, however NSC content of corn silage was highest among the experimental treatments as 31.4%. Daily dry matter intakes per head and also per metabolic basal weight (DM g/kg of $BW^{0.75}$ were significantly (p<0.05) higher in D of the highest mixed ratio of apple pomace (605.3, 69.5g) than those of corn silage (E: 394.0, 46.8g). Daily live weight changes were significantly (p<0.05) higher in 40% (C: 16.7g) and 60% (D: 22.9g) apple pomace mixed ratios than 0% (A: 0.17g) and 20% (B: 4.3g) apple pomace mixed ratios. Digestibilities of dry matter and organic matter were higher in D and E than in A and B and those of ADF and NDF were higher in D as 50.2 and 57.4% respectively than the digestibilities in A, B and E. Nitrogen retention (g, %) was highest in D of the highest mixed apple pomace ratio (1.4g, 20.4%) however lowest in A (-0.3g, -7.75%).