• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.205-210
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• 1999

The Mo(V) $di-{\mu}-oxo$ type $[Mo_2O_4(H_2O)_2L]Cl_2$ complexes(L: 4,4'-Diphenyl-2,2'-dipyridyl, 4,4'-Dimethyl-2,2'-dipyridyl, 4,7-Diphenyl-1,10-phenanthroline) have been prepared by the reaction of $[Mo_2O_4(H_2O)_6]^{2+}$ with a series of chelate ligands. These complexes are completed by two terminal oxygens arranged trans to one another and each ligand forms a chelate types. In $Mo_2O_4(H_2O)_2L$ two $H_2O$ coordinated at trans site of terminal oxgens. The prepared complexes have been characterized by elemental analysis, infrared spectra, electronic spectra, $^1H$ nuclear magnetic resonance spectra, and thermal analysis(TG-DTA). In the potential range -0.00V to -1.00V at scan rate of $50mVs^{-1}$, a cathodic peak at -0.83V ${\sim}$ -0.88V (vs SCE) and an anodic peak at -0.54V ${\sim}$ -0.88V (vs SCE) have been observed in aquous solution. The ratio of the cathodic to anodic current(Ipc/Ipa) is almost 2, we infer that redox is irreversible as dimer forms broken.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.30.3-31
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• 2009

"칠정산 외편"은 태양 태음 오성의 운행, 교식(交食), 태음오성능범(太陰五星凌犯) 등의 천문 현상을 추보하는 데 필요한 표(입성)[立成]와 계산법을 수록한 역법서이다. 최근에 우리는 칠정산 외편의 일식과 일출입 계산의 전 과정을 전산화하였다. 잘 알려진 바와 같이, 관측지의 위도와 관련된 두 입성-"주야시 궁도분 입성"(晝夜時宮度分立成), "경위시 가감차 입성"(經緯時加減差立成)-의 계산 기준점은 중국의 난징이다. 위도와 관련이 없는 다른 입성들 역시 회회력에 수록된 것과 동일하다. 그러나 외편법으로 구한 합삭과 식심 시각은 난징이 아닌 한양의 지방시 시각이다. 이 역설을 해결할 단서는 달의 평균 황경, 즉 태음 중심행도(太陰中心行度) 계산에 쓰이는 보정 상수에 있다. 이론적인 보정값, 즉 외편법의 입성 조성 원리에 부합하는 보정값($243^{\circ}58'$)과 "외편"에 기록된 실제 보정값($243^{\circ}44'$)의 차이는 한양과 난징의 시차(時差)에 따른 달의 황경 증가량과 대략 일치한다. 한양 기준의 합삭 시각을 구하려면 "외편"에 기록된 보정값($243^{\circ}44'$)을 적용하여야 한다. 반면에 이론적인 보정값($243^{\circ}58'$)을 적용하면 합삭 시각이 난징의 지방시로 계산된다. 이 발표에서는 "칠정산 외편"의 역원(曆元)의 차이에 따른 보정 상수 중에서 태음과 관련된 상수 네 개가 모두 일정한 규칙에 따라 한양의 경도에 맞게 조정되었음을 밝힐 것이다. 아울러 태음중심 행도 보정값과 관련된 선행 연구의 오류들을 모두 바로잡고자 한다.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.254-260
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• 2001

The Mo(V) $di-{\mu}-oxo$ type [$Mo_{2}O_{4}(H_{2}O)_{2}L_{2}$] $SO_{4}$ complexes(L: 2,2'-dipyridyl,4,4'-ethylenedianlline) have been prepared by the reaction of $[Mo_{2}O_{4}(H_{2}O)_{6}]SO_{4}$ with a series of chelate ligands. These complexes are completed by two terminal oxygens arranged trans to one another and each ligand forms a chelate types. In $Mo_{2}O_{4}(H_{2}O)_{2}L_{2}$, two $H_{2}O$ coordinated at trans site of terminal oxygens. The prepared complexes have been characterized by elemental analysis, infrared spectra, $^{1}H$ nuclear magnetic resonance spectra, and thermal analysis(TG-DTA). In the potential range -0.00V to -1.00V at a scan rate of $50mVs^{-1}$, a cathodic peak at -0.81V ${\sim}$ -0.87V (vs SCE) and an anodic peak at -0.61V ${\sim}$ -0.63V (vs SCE) have been observed in aquous solution. We infer these redox are irreversible reaction.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.136-142
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• 2014

In an attempt to find natural sources of antioxidants and whitening agents, comparisons of the antioxidative and tyrosinase inhibitory activities of various ethanol extracts of Cuscutae Semen, Rubi Fructus and Paeoniae Radix were carried out. Comparison of the three ethanol extracts revealed that, Paeoniae Radix had the highest electron-donating ability(79.3%),; however, Rubi Fructus had the highest SOD-like ability(31.1%). The xanthine oxidase experiment exhibited a hindrance effect of 74.3% in Cuscutae Semen, 80.4% in Rubi Fructus and 60.8% in Paeoniae Radix. A tyrosinase inhibitory activity assay was conducted to evaluate the whitening effects of the extracts, The tyrosinase inhibitory activity was 20.1% in the Cuscutae Semen, 54.2% in the Rubi Fructus, 56.3% in the Paeoniae Radix. Based on these results, we suggest that the ethanol extracts of Cuscutae Semen, Rubi Fructus and Paeoniae Radix can be used as food and cosmetic ingredients.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.92-97
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• 1993

Sol-Gel Process is a new method of synthesis of high-quality of glass and glass-ceramics. Ferroeletric material, $BaTiO_3$ powder was made by reacting $Ba(OH)_2$ and $Ti[OCH(CH_3)_2]_4$ in alcohol. There was about 16.5% weight loss in thermogravimetric analysis. It was crystallized to tetragonal structure by heat treatment at $700^{\circ}C$ for 2 hours and had a specific surface area, 16.0 $m^2/g.$ Shrinkage curve by sintering was began around $1100^{\circ}C$ in dilatometer analysis.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.98-107
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• 2010

This paper introduces step by step procedures for the design, fabrication and operation of a solar tracking system. The system presented in this study consists of motion controllers, motor drives, step-motors, feedback devices and other accessories to support its functional stability. CdS sensors are used to constantly generate feedback signals to the controller, which assures a high-precision solar tracking even under adverse conditions. It enables instant correction if the system goes off track by strong winds causing gear backlash. A parabolic dish concentrator is mounted on the tracking system whose diameter was 30cm. The solar position data, in terms of azimuth and elevation, sunrise and sunset times were compared with those of the Astronomical Applications Department of the U.S. Naval Observatory. The results presented here clearly demonstrate the high-accuracy of the present system in solar tracking, which are applicable to many existing solar systems.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.346-351
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• 1999

According to their flower color and the shape of petal, sepal, and lip, Calanthe species native to Cheju Island are named as follows; 'Arang', 'Cheongsu', 'Sara', 'Aeyeol', 'Darigot', 'Saebaengi', 'Andeok', 'Setbyeol', 'Kyorae', 'Jasujeong', 'Baekrok', 'Seokwang', 'Deokcheon', 'Seonheul', 'Saechimi', 'Jokduri', 'Baedal', 'Noksu', 'Noeul', and 'Dansim for 20 cultivars of Calanthe discolor; 'Hwanghee', 'Waheul', 'Illchool', 'Hwangryong', 'Dabo', 'Hwangjinee', 'Daeha', 'Chwikwang', 'Seokyang', 'Eunpa', 'Chwiseon', 'Sinbaram', 'Ara', 'Dano', 'Pakae', and 'Sojeob' for 16 cultivars of Calanthe sieboldii; 'Dongkwang', 'Myeongdeok', 'Wangdolseon', 'Myeongryeok', 'Kwibuin', 'Semi', 'Cheonwangsa', 'Mandeok', 'Seolmundae', 'Kyeongok', 'Darangsi', 'Byeolbang', 'Honghak', 'Dongbaeksan', 'Chejudo', 'Samda', 'Kwandeok', 'Youngjusan', 'Tamra', 'Koyeongdi', 'Yongduam', and 'Jeolbuam' for 22 cultivars of Calanthe bicolor.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.381-386
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• 2010

We have cultured the bluefin tuna in Yokjido, Tongyeong with floating cage which was vulnerable to harmful dinoflagellate, Cochiodinium polykrikoides. This study inspected a vertical migration of phytoplankton and Chl-a for reasonable sinking depth in floating cage. Furthermore, we analyzed the fluctuation of the phytoplankton including harmful dinoflagellates occurring in Yokgido for 6 years. Total cell density showed a significant monthly variation and the flora was predominated with diatoms. Gymnodinium sp. occurred 19 times, the greatest number of occurrence in all kinds of dinoflagellates during summer. In particular, the total number of occurrence at C. polykrikoides was 8, and harmful dinoflagellates such as Karenia brevis/Fibrcapsa japonica occurred. The relationship between Chl-a concentration/total cell number and sunset/sunrise was significant and reasonable sinking depth in floating cage was found to be at least 3m from the water surface, which was associated with massive fish kills caused by C. polykrikoides.

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.69-74
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• 2020

The current study was conducted to evaluate the effect of music enrichment on the live body weight of chickens and meat quality grade of the carcasses. Fourteen flocks at four broiler farms with identical windowless houses were provided with identical starter and finisher diets. These were either exposed to classical music or not exposed to any music from the starter to slaughter age. At 30 days posthatch, the chickens were transported from farms to a slaughterhouse. Two hundred carcasses from each flock were randomly selected for measurement of the carcass traits by the licensed meat inspectors at the slaughterhouse. The live body weights at the slaughter age were not significantly different between the two treatments. In addition, music enrichment did not affect meat freshness (i.e., torrymeter values) nor did it affect other carcass trait variables including percentage of bruises, flesh blemishes, abnormalities, and quality A grade. In conclusion, music enrichment did not affect the body weight or carcass quality of broiler chickens.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.43-47
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• 2003

Air temperature was continuously measured in hilly pear orchards at 4 sites with elevations of 10, 49, 104 and 253 m above sea level. The mean air temperature, averaged over the 10-month period from August 2001 to June 2002, decreased as the site elevation increased by 0.2$^{\circ}C$ per 100 m. This weak lapse condition was amplified during daytime by sun-slope geometry. But on most days an inversion condition began by sunset and persisted until the next sunrise. During the observation period, daily minimum temperature at the valley bottom was lower than that of the hilltop on 67% of the days, and the average temperature difference was 1.4$^{\circ}C$. Inversion of daily minimum temperature under clear sky conditions was stronger in spring and autumn than in winter with a maximum of 6$^{\circ}C$. Lapse condition was predominant in daily minimum temperature on rainy days, and the lapse rate was strongest in winter.