http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 조현갑 (검색결과 16 건)
- 무료
- 기관 내 무료
- 유료
-
-
극저온 볼 밀링을 통한 Ibuprofen 분말의 마이크로화
조현갑(Hyun Kab Cho),이경엽(Kyong Yop Rhee),백영남(Young Nam Paik),박훈재(Hoon Jae Park),이상목(Sang Mok Lee) Korean Society for Precision Engineering 2004 한국정밀공학회지 Vol.21 No.11
For the present study, the cryogenic ball milling process was applied to make Ibuprofen microsized. The cryogenic ball milling was performed at low temperature of about -180℃ for 6 hours. The particle size distribution was determined before and after the cryogenic process. X-ray diffraction (XRD) measurement was made to determine the effect of cryogenic process on the crystallinity of Ibuprofen. The results showed that the size of Ibuprofen was reduced about 10 times by the cryogenic process. The degree of crystallinity of Ibuprofen was slightly reduced by the cryogenic process.
-
극저온 볼 밀링을 통한 Ibuprofen 분말의 나노화Ⅱ
조현갑(H.K. Cho),이경엽(K.Y. Rhee),백영남(Y.N. Paik),박훈재(H.J. Park),이상목(S.M. Lee) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월
Reducing the particle size of drug materials down to submicron is an important matter in pharmaceutical industry. Cryogenic milling technology is one of the mechanical milling processes, which is mostly utilized in refining grain size of metal and ceramics at extremely low temperature environment. This technique has not been readily studied in application to medical and biotechnology. This paper, therefore, describes the application of cryogenic milling process to reduce particle size of Ibuprofen. The shape and size of the Ibuprofen particle before and after the cryogenic ball milling process were analyzed. XRD analysis was performed to examine a change in crystallinity of Ibuprofen by the cryogenic ball milling process. The results showed that the size of Ibuprofen particles was reduced to 1/10 or less of its initial size. The results also showed that the degree of crystallinity of Ibuprofen was slightly reduced after cryogenic ball milling with nitrogen.
-
Al-Fe-Ni 공정복합합금의 응고속도에 따른 전기저항의 변화
이재갑,조현기 경북대학교 산업기술연구소 1988 産業技術硏究誌 Vol.17 No.-
Numerous researchs have been investigated concerning the mechanism of unidirectionally solidification and the relationships between microstructure and growth rate in eutectic alloys. Although it is expected that the anisotropic microstructure associated with eutectic should produced the interesting electrical properties, almost all studies on eutectic composite alloy have been investigated about morphology, mechanical properties and thermal stability. In the present study, changes of electrical resistivity according to cooling rate in Al-Fe-Ni eutectic composite alloy is investigated. The obtained results are as follows; As cooling rate(R) increased, electrical resistivity of Al-Fe-Ni eutectic composite alloy at 520℃ increased with increaseing of fineness of eutectic fibers and formation of cellular structure. The higher the cooling rate, the higher the temperature dependence of electrical resistivity and the lower the stability of eutectic composite alloy, respectively.
-
-
-
-
-
Mg0.5Sr0.5FCl0.5Br0.5 혼합 결정 내에 도핑된 Sm2+ (1 mol) 이온들의 발광 특성 및 영구적 스펙트럼 홀 생성
장기완,조현갑,조은진,김상수,한창희,정용화,박성태,서효진 한국물리학회 2003 새물리 Vol.46 No.4
Mg$_{0.5}$Sr$_{0.5}$FCl$_{0.5}$Br$_{0.5}$ mixed crystals containing Sm$^{2+}$ were prepared by mixing MgF$_2$, SrCl$_2$$\cdot$6H$_2$O, SrBr$_2$$\cdot$6H$_2$O and Sm$_2$O$_3$ in stoichiometric amounts and then heating the mixture for 1 hour at 1,100 $^\circ$C in flowing hydrogen gas atmosphere. The optical properties of the samples were studied through emission spectroscopy and persistent spectral holeburning (PSHB). The emission spectrum due to the ${^5}$D${_1}$ $\rightarrow$ $^7$F$_0$ transition was shifted toward low energy with decreasing temperature. The PSHB was made by using a one-color or a two-color process at 300 K but by using a two-color process at 1.5 K. MgF$_2$, SrCl$_2$$\cdot$6H$_2$O, SrBr$_2$$\cdot$6H$_2$O와 Sm$_2$O$_3$를 정량적으로 혼합하여 수소가스가 흐르는 알루미나 관내에 넣고 1100 $^\circ$C에서 한 시간 동안 열처리하여 Sm$^{2+}$가 도핑된 Mg$_{0.5}$Sr$_{0.5}$FCl$_{0.5}$Br$_{0.5}$ 혼합결정을 제조하였다. 제조된 시료들에 대해 발광 특성 및 실온과 1.5 K 에서의 영구적 스펙트럼 홀 생성 특성에 대해 연구하였으며, ${^5}$D${_1}$ $\rightarrow$ $^7$F$_0$ 천이에 의한 발광 스펙트럼은 온도가 하강함에 따라 낮은 에너지 쪽으로 이동되는 것을 관측하였다. 또한 단색 및 이색 홀 생성 방법을 이용하여 영구적 스펙트럼의 특성을 조사한 결과, 실온에서는 단색 또는 이색 홀 생성 방법에 의해서도 영구적 홀이 잘 생성되나 1.5 K에서는 단색 홀 생성 방법에 의해서는 영구적 홀이 잘 형성되지 않는데 비하여 이색 홀 생성 방법에 의해서는 훨씬 더 효율적으로 생성되는 재미있는 결과를 얻었다.
-
최양일,조현갑,김일석 한국축산학회 1998 한국축산학회지 Vol.40 No.1
This study was undertaken to investigate the pH, sensory and storage characteristics of 7 domestic chilled porks during 21 days of storage at 4℃. The pH values of chilled porks at 0 day of storage were 5.47∼5.67. Until the 21 days of storage period, the pH values of all chilled porks appeared to be normal. 1n the proximal analysis of chilled porks, the ranges of moisture and fat contents were larger than the other contents. However, all the chilled porks contained more than s% fat content and showed deposit of intramuscular fat well enough. In visual color scores, all the chilled porks showed high color scores until 14 days of the storage period except one sample of PSE(Pale, soft, exudative) meat. In sensory flavor scores, all the chilled porks showed similar scores and there was no sex odor problem. In sensory juiciness and tenderness scores, there were little differences among the porks at 0 day of storage, but after 3 days all the porks showed increased scores resulting from the aging effect until the 14th day of storage period. During the 21 days of storage at 4 C, the VBN (volatile basic nitrogen) values of chilled porks were in safe range until the 14th day of storage and the TBA(2-thiobarbituric acid) values of chilled porks were in very safe range until the 2lst day. In the total microbial counts, there were little differences among the porks at 0 day of storage, but they showed safe ranges(below the 106 Colony forming unit/g) until the 14th day. However, they reached the putrefaction ranges the 21st day of storage. In the coliform bacteria counts, 3 chilled porks among 7 companies showed coliform bacteria counts, but the count numbers were not high. However, better and/or tighter pork quality control should be necessary during the slaughtering and processing lines.
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
