Ce$O_2$첨가 및 분말처리가 U$O_2$ 분말의 소결에 미치는 영향

김형수,이영우,최창범,양명승,전풍일,Kim, Hyeong-Su,Lee, Yeong-U,Choe, Chang-Beom,Yang, Myeong-Seung,Jeon, Pung-Il 한국재료학회 1993 한국재료학회지 Vol.3 No.3

순수 $UO_2$에 첨가량 변화 및 ball-milling 시간에 따른 (U, Ce)$O_2$ 분말의 특성과 각 조건별로 제조된 분말을 압분 및 소결하여 (U, Ce)$O_2$ 분말 특성에 따른 소결성을 비교 조사하였다. 실험 결과로 부터 ball-milling시간이 길어짐에 따라 입자들은 미세화되고, Ce$O_2$ 함량이 증가할수록 압분, 소결밀도는 저하 하였으며, $CeO_2$는 소결성을 저하시키는 산화물임을 확인하였다. 10wt%,$CeO_2$ 가 첨가된 (U, Ce)$O_2$ 분말의 경우, ball-milling 4시간 수행한 분말의 소결체가 기공의 수도 적고, 구형에 가까왔으며, 소결밀도가 가장 높았다. 이는 4시간 ball-milling한 (U, Ce)$O_2$분말이 비표면적이 크로 그의 packing ratio가 적절하였기 때문이다. We investigated the changes of (U, Ce)$O_2$ powder characteristics with $CeO_2$ contents and ball-milling time and then studied on the sintering properties with those (U, Ce)$O_2$ powder characteristics. From the results of this study, it was concluded that the longer ball-milling time of (U, Ce)$O_2$ powder was, the finer its particle size was. Green and sintered densities were decreased with $CeO_2$ contensts increase. And also $CeO_2$ was recongized deteriorating oxide on the $UO_2$ sintering. In case of the lOwt. % $CeO_2$ contents, (U, Ce)$O_2$ sintered pellet which was made of ball-milled powder for 4 hours had few pores and its pores got near to the sphere. And its sintered density had the highest. Because its powder had higher surface area and its packing ratio was appropriated much better than others.

Zinc stearate의 첨가가 $UO_{2}$분말의 겉보기밀도, 혼합 및 성형에 미치는 효과

나상호,김시형,이영우,양명승,손동성,Na, Sang-Ho,Kim, Si-Hyeong,Lee, Yeong-U,Yang, Myeong-Seung,Son, Dong-Seong 한국재료학회 1995 한국재료학회지 Vol.5 No.4

윤활제인 zinc stearate의 첨가량 (0~4wt%)을 변화시켜 U$O_{2}$분말의 겉보기밀도, 성형시의 분말입자간 마찰과 입자/다이벽 마찰간의 상관관계를 조사하였다. 소량의 윤활제 첨가시에는 U$O_{2}$분말입자간 박막의 윤활제 도포층이 형성되어 겉보기밀도가 증가한 반면 다량의 윤활제를 첨가한 경우에는 U$O_{2}$ 분말입자에 두꺼운 윤활제 도포층이 형성되고 미혼합된 윤활제가 존재하여 겉보기밀도는 감소하는 경향을 보였다. 윤활제를 첨가혼합한 상태에서 다이벽 윤활도포 유무에 따라 구한 U$O_{2}$ 성형체의 성형압력/성형밀도 자료로부터 분말입자간 마찰, 입자/다이벽 마찰 그리고 성형시 lubrication/inhibition등의 상대적 중요성을 조사하였다. 입자/다이벽 마찰에 의한 압력손실은 입자간 마찰에 의한 압력손실보다 크게 나타났다. 입자/다이벽 마찰에 의한 압력손실은 다이벽 윤활제 도포에 의해 최소화될 수 있지만 상대적으로 바람직하지 않은 성형시의 inhibition이 야기되는 것으로 나타났다.

인광석의 인산비효증진에 관한 연구-토양중 mycorrhizae 포자밀도조사 및 인광석용해성사상균의 분리와 배양-

유장걸,김형옥,이신찬 제주대학교 1985 논문집 Vol.20 No.-

To make a survey on the distribution of V. A. mycorrhizae on Cheju-Island. 60 soil samples were taken from the cultivated and non-cultivated lands (27 volcanic soils and 33 non-volcanic soils). Spore densities (spore number/100g soil) were measured by the floating method Phosphate-solubilizing fungi were isolated from 18 soil samples and selected by the pure cultivation method on PDA-calcium phosphate media Adaptation cultivations of the selected fungi were conducted in the rock phosphate-liquid media succeesive- ly with the change of sugar to straw composition. 1. Low spore density below 100 was observed in 19 sampling sites and high density above 500 was shown in only five fields, rest of the locations being ordinary levels. It seemed that spore density was related to the locality but not to pH. water content, total nitrogen and phosphate percentage of the soil. 2. Phosphate solubilizing fungi were found on PDA-calcium phosphate media in 41 soil samples. 3. After 6-day pure cultivatin on PDA-media. fungi having 8-15mm of colony radii(R). 14-22mm of halo radii(H) and higher H/R ratio than 1.2. were obtained in 18 soil samples. 4. Five successive cultivations in the liquid media containing powdered rock phosphate were undertaken to adapt the selected fungi to the low sugar/straw condition (sugar 0.35%. straw 1.15%). At the end of 5 th cultivation, seven fungi (from soil No. 1. 8. 24, 26. 31, 43 and 45) remained and showed about 29 percentage of rock phosphate solubility making the liquid media neutral.

??C追跡子法에 依한 柑橘의 糖과 有機酸에 關한 硏究 : Effects of Foliar Application of ?? ??의 葉面處理效果

金瀅玉,康順善,柳基中,柳長杰 제주대학교 방사능이용연구소 1985 연구보고 Vol.1 No.-

柑橘(Citrus unshiu Marc.)의 糖, 有機酸 및 아미노酸에 대한 ??의 영향을 보기 위하여 KCI과 K₂SO₄溶液을 葉面處理하고 ?? 를 同化시킨 뒤 ??C로 標識된 同化産物의 徑時的 變化를 3週間 調査하였다. ?? 處理後 1週日間 果實에 轉流된 ??C 同化産物의 比放射能(cpm/㎖)은 ?? 處理區에서 더컸다. 果汁의 糖分劃 放射能은 그 水準과 變化樣相이 ?? 處理間에 差異가 없었지만, 有機酸分劃에 있어서는 ?? 處理後 2週日 以後에 有機酸分劃의 比放射能 減少量이 ?? 處理區에서 더 많았다. 有機酸分劃의 比放射能에 對한 糖分劃比放射能의 比率이 SO?? 處理區에서는 時間이 경과함에 따라 增加하는 경향이었으나 ?? 處理區는 급격히 減少했다. 따라서 ??가 ??보다 果汁의 甘味比를 증가시키는 것으로 생각되었다. 아미노산分劃의 比放射能은 ?? 處理區보다 ?? 處理區에서 더 많이 增加했다. The effects of spraying ?? solutions on sugar, organic acid and amino acid levels in citrus(C. unshiu Marc.) fruit juice were examined using the ?? method. Each ?? compound under investigation was measured during the three weeks after ??assimilation. The total carbon compound, which was measured as the specific activity (cpm/㎖) of ??, was transported more into the fruit juice within one week after ??assimilation with the SO treatment than with the ?? treatment. The ?? activity changes of the sugar fraction were very similar in both ?? and ?? treatments although the organic acid fraction was reduced more by ??. The specific activity ratio of the sugar fraction to organic acid was increased rapidly when treated with ??. This indicates that ?? plays a role in raising the ratio of sugar to organic acid. It was found that the ?? activity in the amino acid fraction was higher when ?? was applied.

식물근권중의 질소고정균 특성에 관한 연구

김형옥,황다리아,유장걸 제주대학교 방사능이용연구소 1988 연구보고 Vol.3 No.-

본 연구는 아열대성 기후를 가지는 제주지역의 벼의 근권중에 서식하는 질소고정균의 특성을 조사하고자 수행되었다. MPN방법을 이용, 제주도내의 수도재배 5개 지역과 육도재배 6개 지역에서의 질소고정균 밀도와 분포를, 그리고 미생물과 토양의 화학적 성질과의 상호관계를 검토하였고, 한편 이들로부터 질소환원효소 활성이 높은 미생물을 선발하여 그들의 생리적 특성과 식물과의 상호관계에 관한 연구를 수행하였다. 1. 수도 뿌리중의 미생물 밀도는 육도와 비슷한 수준이었다. 그리고 근권토양의 미생물 밀도는 육도지역이 수도지역보다 potato agar배지와 dobereiner배지에서 더 높았지만 azotobacter배지에서는 반대로 논토양이 밭토양보다 미생물 밀도가 더 높았다. 2. 뿌리중의 미생물 밀도는 모든 조사대상 지역에서 토양보다 더 높게 나타났다. 3. 지역간의 MPN 값을 보면 수도에서는 시료 채취지역간에 비슷하였는데, 육도에서는 태흥, 송당, 시흥이 다른 곳에 비해 미생물 밀도가 더 높았다. 4. 사용한 배지에 따른 MPN 값은 뿌리와 토양에 관계없이 potato agar 배지에서 제일 높았고, dob + multivitamin 배지, dobereiner 배지, 그리고 azotobacter배지의 순서로 낮았다. 5. 이와같은 미생물의 밀도분포는 토양의 화학성 즉, 유기물함량, 전인산, 전질소와 밀접한 정의상관( 1% 유의성 ) 을 보였다. 6. 선발된 질소고정미생물(HP, SU, TU)은 탄소원 및 blotin요구도, pH, 8 % NaCl 배지에서의 생장여부 등 생리적 특성에 있어서 azospirillum brasilence와 유사하였다. 7. 또한, 이들 질소고정미생물은 무균적으로 재배된 벼의 뿌리에 흡착되어 협생할 수 있었고, 흡착정도는 선발된 미생물 모두 비슷한 경향이었으나 수도보다는 육도에 더 잘 흡착되었다. 8. 한편, 식물뿌리에 협생된 미생물의 acetylene환원력은 수도지역에서 분리된 질소고정 미생물(HP)의 경우 육도보다 수도에서, 육도지역에서 분리된 미생물은 수도보다 육도에서 더 높았다. The distribution and characteristics of nitrogen fixing bacteria associated with the rice plant roots were investigated, taking the roots and soil samples from five paddy and six upland fields on Cheju-do. In the first year, the population density of root associative microorganisms existing in the rice roots and soil was determined using MPN method and correlated with chemical properties of the soils. In the second year, the N-fixing bacteria (HP, SU, TU) having high acetylene reduction capacity were selected and their physiological characteristics were examined, comparing with A. brasilence and A. lipoferum. Association of the selected bacteria with the rice roots was confimed in vitro under the asceptic condition. 1. The population density of microorganisms existing in the paddy rice roots was similar to that of the upland rice roots. The upland soils showed higher MPN on potato agar and Dobereiner media than the paddy soils. On Azotobacter media, however, the paddy soils higher MPN than the upland soils. 2. Regardless of sampling sites, and the used media, much more microorganisms ( general heterotrophic and N-fixing ) were observed in the roots than in the soils. 3. In the paddy rice fields, all the sampling sites gave very similar MPN in both the roots and the soils. In the uplands, however, microoraganism densities were varied with the sampling sites; Tacheung, Songdang, and Siheung showed higher MPN in the roots and in the soils, than the other sampling sites. 4. There were highly significant differences in MPN depending on the media. Potato agar media showed the highest MPN, which decreased in the order of Dob.+multivitamin media, Dobereiner media, and Azotobacter media. 5. Statistically significant correlation was found between the population density of microorganisms in the soils ( upland and paddy field ) and the soil chemical properties such as organic matter, total N, total P, and pH. 6. The physilological characteristics of nitrogen fixing bacteria (HP, SU, TU) selected were similar to those of A. brasilence. 7. All of the selected bacteria (HP,SU, TU) made good association with the paddy and upland rice roots, showing better association in the upland than in the paddy rice. 8. The bacteria isolated from the paddy fields made higher acetylene reduction when associated with the paddy rice than with the upland rice while the bacteria from the upland had more acetylene reduction on the upland rice roots than on the paddy rice roots.

제주도 감귤원 토양의 V.A-mycorrhizae분포 및 사상균에 의한 인광석의 용해에 관한 연구

김형옥,유장걸,이신찬,R.M.N. Kucey 제주대학교 1984 논문집 Vol.17 No.-

The mycorrhizae spore densities (spore numbers/100g soil) were measured on six sites of citrus field by the floating method to estimate the mycorrhizae distniution on volcanic ash soil in Jejudo. Phosphate solubilizing fungi and bacteria in the soils were isolated and selected by the succesive pure culture in the potato dextrose agarcalcium phosphate (PDA-P) media. The phosphate solubilizing capacities of the sele-cted fungi were measured after incubating in the liquid media mixed with 200 mg of powdered rock phos-phate for one week. 1. The highest spore density (456/100g soil) was observed in the soil from the 6 years citrus field located on Samyangdong, Jeju-si and the next one (385/100g soil) from the 18 years citrus field at the same place. The soils from Topyeongdong, Seogwipo-si (1)(2) were found to contain lower mycorrhizae spores than other sampling sites, 256/100g soil at seven years citrus field and 166/10g soil at twenty one years citrus field. 2. Colony radii and halo radii of bacteria measured 4mm - 11mm and 6mm-22mm, and colony radii and halo radii of fungi were 8mm-12mm and 14mm-18mm respectively when they were incubated in PDA-P media for one week. 3. The selected fungi, based on the radius size of colony and halo, dissolved 0.46mg-2.64mg P_(2)0_(3) from 200mg of powdered rock phosphate in the liquid media.

정위상 및 탈위상 경사에코영상과 생체 수소 자기공명분광법을 이용한 담낭 담즙내 지질성분의 측정$^1$

신석환,조순구,김영수,우제홍,김형진,서창해,Sin, Seok-Hwan,Jo, Sun-Gu,Kim, Yeong-Su,U, Je-Hong,Kim, Hyeong-Jin,Seo, Chang-Hae 대한영상의학회 2002 대한영상의학회지 Vol.46 No.2

목적: 지질 억제 자기공명영상 기법과 수소 자기공명분광에서 측정한 지질 피크의 상대적 비율을 비교 분석하여,이 두 방법에 의한 담낭내 담즙 지질의 정량적 분석이 가능한 지를 알아보고자 하였다. 대상과 방법: 간기능 검사 및 콜레스테롤 수치가 정상이며, 초음파검사에서 담낭벽의 비후가 없고 담낭이 잘 팽창되어 있는 정상자원자 26명을 대상으로 하였다.담낭의 정위상 및 탈위상 경사에 코영상에서 담낭의 신호강도 차이를 계산하였으며, 담낭 자기공명분광 스펙트럼의 지질피크(0.8-1.6 ppm)와,2.0-2.4 ppm,3.2-3.4 ppm,3.9-4.1 ppm,5.2-5.4 ppm에서 관찰되는 피크의 넓이를 측정하였다. 전체 피크의 합에 대한 지질피크의 비율를 계산하였고, 신호강도 비율과 지질피크 비율를 비교하였다. 결과: 정위상 및 탈위상 자기공명영상에서의 신호강도비율은11.3-43.4%(평균 26 $\pm$8.9%)였고, 생체 수소 자기공명분광의 가장 현저한 피크는 지질피크(21명,92%)였으며, [ 피크0.8-1.6 ppm의 면적/모든 피크의 면적의 합] 은 0.10-0.97(평균 0.66 $\pm$0.21)였다. 신호강도 비율과 지질피크 비율의 상관성은 통계적으로 의미있는 상관성을 보였다(r=0.478,p=0.014). 결론: 지질 억제 자기공명영상 기법과 수소 자기공명분광법이 담낭내 담즙 지질성분을 측정하는 방법으로 이용될 가능성이 있다. Purpose: To evaluate the utility of signal intensity differences between in- and opposed-phase MRI and the lipid peak ratio in in-vivo proton MR spectroscopy of the gallbladder as diagnostic tools for measuring the lipidcontent of gallbladder bile. Materials and Methods: Twenty-six normal volunteers underwent MR imaging (FMPSPGR) and in-vivo proton MR spectroscopy of the gallbladder. In all cases the results of liver function tests were normal, as were cholesterol levels,and ultrasonography of the gaubladder revealed nothing unusual. For MRI and MRS a 1.5T unit (Signa Horizon; GE Medical Systems, Milwaukee, U.S.A.) was used. In-phase and opposed-phase coronal-section MR images(FMPSPGR; TR=125 msec, TE=1.8, 4.2 msec) of the gallbladder were obtained, and differences in signal intensity thus determined. For proton MR spectroscopy of the gallbladder, a localized proton STEAM sequence was employed. A single voxel of 1-8 cm3 was placed at the center of the gallbladder cavity, peak areas at 0.8-1.6 ppm (lipid), 2.0-2.4 ppm, 3.2-3.4 ppm, 3.9-4.1 ppm, and 5.2-5.4 ppm were measured by proton MRS and the relative peak area ratios of peak 0.8-1.6 ppm/other peaks were calculated. The degree of correlation between signal intensity differences at MRI and the relative peak area ratio of lipid in proton MRS was estimated using the p-value and Pearson's correlation coefficient. Results: Signal intensity differences ranged from 11.3 to 43.4% (mean,26$\pm$8.9%), and the range of lipid peak area ratio at MRS was 0.10-0.97 (mean, 0.66$\pm$0.21). There was significant correlation between the two measured values (P=0.014, Pearson’s correlation coefficient=0.478). Conclusion: In normal cystic bile, signal intensity differences at in- and opposed-phase MRI and relative lipid peak area ratios at MRS varied, though both methods could be used diagnostically for measuring the lipid contents of body tissue.

Realization of Wafer-scale 1T-MoS₂ Film using Cold-Plasma

Hyeong-U Kim,Woo Seok Kang,Dae-Woong Kim,Dae Hoon Lee,Jae-Hyun Lee,Taesung Kim 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.5

α-glucosidase inhibition of Cudrania tricuspidata according to each parts and period. (초)

( Hyeong U Son ),( Chul Hong Park ),( Jin Chul Heo ),( Dong Yoon Nam ),( Si Rim Lee ),( Hyun Jin Lee ),( Tae Yang Cha ),( Jin Hong Baek ),( Sang Han Lee ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2010 한국식품저장유통학회 학술대회 Vol.2010 No.-

Low temperature synthesis of wafer scale 2D materials and application

Hyeong-U Kim(김형우),Atul Kulkarni(아툴 쿨카르니),Hyeyoun Kim(김혜윤),Dongjoo Shin(신동주),Vinit Kanade(비니트 카나데),Minho Lee(이민호),Taesung Kim(김태성) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.5