분광광도법에 의한 3-Chloro 및 3-Bromopyridine의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,尹永炷,金學成 慶北大學校 1984 論文集 Vol.38 No.-

Pyridine and most of substituted pyridines react as base in aqueous solutions. Strength of their basicities can be represented quantitatively by the dissociation constant of a base or its conjugated acid. The dissociation constants of weak acid or base are highly dependent on the pressure and the temperature. The dissociation constants of these substituted pyridines have been reported only under the pressure of atmosphere but not high pressure. In this study, we measured the dissociation constants of 3-chloro and 3-bromopyridine under high pressure by the method of spectrophotometry. Also, we obtained the thermodynamic parameters on the dissociation reactions that show the effects of the temperature and the pressure on the dissociation constants.

몇가지 치환 피리딘계 화합물의 해리에 미치는 온도와 압력의 영향

황정의,윤영주,김학성 慶北大學校 物理化學硏究所 1983 硏究論文集 Vol.4 No.-

피리딘이나 치환 피리딘 화합물은 염기로서 작용한다. 염기도는 적량적 표시로 염기의 해리 상수나 공액산의 해리 상수로서 나타낼 수 있다. 즉 ◁그림삽입▷(원문을 참조하세요) 반응의 Ka값으로 나타낼 수 있다. 이들 피리딘 치환체의 해리 상수는 상압에서만 알려져 있으나 고압하에서는 전혀 측정된바 없다. 그래서 본 연구에서는 높은 압력하에서 이들 해리 상수를 분광법과 전도도법으로 측정하는 시도를 하였다. 분광법은 흡수 띠가 UV 영역에 있어서 UV 분광법으로 측정했다. 전도도법은 보통 방법으로는 불가능하였고 상압에서의 해리 상수를 알고 있는 물질에 대해서 용액의 전도도를 측정하고, 이 값에서 관여 이온 전도도를 계산하여 해리 상수를 계산하였다. 측정은 m-chloro, m-bromo 및 o-bromopyridine에 대해서 이루어졌으며 양방법에 의한 값들 사이에 약간의 차이가 있었으나 이온 전도도법에 사용한 가정이나 외삽한 값을 이용한 점을 감안할때 비교적 성공적이라고 할 수 있었다. 또 해리반응에 대한 열역학적 데이터를 감안할때 온도나 압력에 따른 변화가 비슷하게 얻어졌고 이들 값을 미루어 보아 해리과정을 추적하는데 도움이 되었다. Pyridine and most of substituted pyridines react as base in aqueous solutions. Strength of their basicities can be represented quantitatively by the dissociation constant of a base or its conjugated acid. For example, the basicity of pyridine can be represented by Ka of the following reaction. ◁그림삽입▷(원문을 참조하세요) The dissociation constants of these substituted pyridines have been reported only under pressure of atmosphere but not high pressure. In this study, we try to measure the dissociation constants of some substituted pyridines under high pressure by the methods of conductance, spectrophotometry. Because the adsorption band exists in UV range, we used UV spectrophotometry. In conductometry we could not apply the general method of conductivity, hence measured the conductivity of the mixed ionic species and then calculated the ionic conductances. From the ionic conductivity of hydrogen ion the dissociation constants (Ka) can be calculated. We measured the dissociation constants of m-chloro, m-bromo and o-bromopyridine. There is a little difference between the dissociation constants from spectrophotometric and conductometric methods. But when we consider the approximated conditions and extrapolated values used in calculating ionic conductance, we could conclude that its difference is insignificant. We obtained the thermodynamic data on the dissociation reactions that showing the effect of the temperature and the pressure on the dissociation constants are similar and we can deduce the mechanism of the dissociation process of some substituted pyridines.

전도도법에 의한 치환 피리딘들의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,金學成,尹永炷,朴義煥 慶北大學校 1984 論文集 Vol.38 No.-

Generally, pyridine and most of substituted pyridines act as base in aqueous solutions. The strengths of their basicities can be expressed quantitatively by the dissociation constant of base or its conjugated acid. Generally, the acidity of substituted pyridines can be expressed by K_a of the following reaction. ◁그림 삽입▷ (원문을 참조하세요) The dissociation constants of these subtituted pyridines have not been reported under high pressure but under atmospheric pressure. In this papers, the dissociation constants of some substituted pyridines were measured under high pressure by the conductometry. From the ionic conductivity of hydrogen ion, the dissociation constants (K_a) were calculated. The K_a values were increased with increasing temperature and were decreased with increasing presure. The charateristics of dissociation process of some substituted pyridines were deduced from the thermodynamic properties calculated from the dissociation constants.

전도도법에 의한 치환 피리딘들의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,金學成,尹永炷,朴義煥 慶北大學校 物理化學硏究所 1985 硏究論文集 Vol.6 No.-

Generally, pyridine and most of substituted pyridines act as base in aqueous solutions. The strengths of their basicities can be expressed quantitatively by the dissociation constant of base or its conjugated acid. Generally, the acidity of substituted pyridines can be expressed by K_a of the following reaction. ◁그림삽입▷(원문을 참조하세요) The dissociation constants of these subtituted pyridines have not been reported under high pressure but under atmospheric pressure. In this papers, the dissociation constants of some substituted pyridines were measured under high pressure by the conductometry. From the ionic conductivity of hydrogen ion, the dissociation constants(K_a) were calculated. The K_a values were increased with increasing temperature and were decreased with increasing pressure. The characteristics of dissociation process of some substituted pyridines were deduced from the thermodynamic properties calculated from the dissociation constants.

쌍발 복합재 비행기의 속도, 고도 보정 및 상승성능에 관한 연구

황명신,박윤진,이정모,김칠영,은희봉 한국항공운항학회 1997 한국항공운항학회지 Vol.5 No.1

Airspeed and altimeter calibration of "win Mee was conducted by the flight test. We have adopted system to system method. Flight test data is corrected for instrumented error and position error, and the resultin data was satisfied. Climb Performance flight test also was conducted. But we could not have all data because of limited flight time. The resulted data was satisfied compare with calculated dab.

W-Index 광도파로를 이용한 협대역 스펙트럼 필터에 관한 연구

윤중현,황정연,정래성,김종빈 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.1

In this paper, a narrow-band spectral filter constructed with a W-index optical waveguide is proposed and analyzed. The proposed filter offers a spectral width on the order of one nanometer, considerably narrower than that provided by a filter made of two step-index optical waveguides having the same transmission wavelength. The narrow spectral width is achieved by exploiting a relatively large slope difference between the dispersion characteristics of the W-index and step-index waveguides constituting the filter. The transmission characteristic of the proposed filter with peak transmission at 1550nm is calculated and compared with that of a corresponding filter made of two step-index waveguides

다양한 교정용 미니 스크류의 인공 피질골 두께에 따른 삽입 토오크와 Pull-out 강도 비교

송영윤,차정열,황충주 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.1

본 연구는 스크류의 역학적인 특성을 알아보고자 세 종류의 self-drilling형의 교정용 미니 스크류 (Type A; 순수한 원통형, Type B; 내경이 증가하는 구간이 있는 부분적인 원통형, Type C; 원통형과 원추형이 함께 있는 복합형)를 피질골의 두께를 다르게 설정한 인공골 시편에 삽입하였다. 일정한 회전 속도와 수직력을 부여할 수 있는 구동식 토오크 시험기(Biomaterials Korea, Seoul, Korea)를 이용하여 삽입 토오크를 측정하고 만능시험기(Instron 3366, Instron, Norwood, MA, USA)를 이용하여 Pull-out 강도를 측정하여 다음과 같은 결과를 얻었다. 피질골 두께의 증가에 따른 최대 삽입 토오크(maximum insertion torque) 값은 Type A는 차이가 없는 반면(p> 0.05), Type B와 Type C에서는 유의한 증가가 관찰되었다(p<0.05). 모든 피질골 두께에서 Type C > Type A > Type B의 순으로 최대 삽입 토오크 값이 크게 나타났다(p<0.05). Pull-out 강도는 모든 경우에 Type A가 Type B와 Type C보다 낮게 측정되었다(p<0.05). Type별로 피질골 두께와 최대 삽입 토오크, Pull-out 강도 간에 통계적으로 유의한 상관관계가 있었다(p<0.05). 이상의 결과는 미니 스크류 식립을 위한 디자인 선택 시 식립부위의 피질골 두께를 고려해야 함을 시사한다. Objective: The purpose of this study was to evaluate the mechanical performance of mini-screws during insertion into artificial bone with use of the driving torque tester (Biomaterials Korea, Seoul, Korea), as well as testing of Pull-out Strength (POS). Methods: Experimental bone blocks with different cortical bone thickness were used as specimens. Three modules of commercially available drill-free type mini-screws (Type A; pure cylindrical type, Biomaterials Korea, Seoul, Korea, Type B; partially cylindrical type, Jeil Medical, Seoul, Korea, Type C; combination type of cylindrical and tapered portions, Ortholution, Seoul, Korea), were used. Results: Difference in the cortical bone thickness had little effect on the maximum insertion torque (MIT) in Type A mini-screws. But in Type B and C, MIT increased as the cortical bone thickness increased. MIT of Type C was highest in all situations, then Type B and Type A in order. Type C showed lower POS than Type A or B in all situations. There were statistically significant correlations between cortical bone thickness and MIT, and POS for each type of the mini-screws. Conclusion: Since different screw designs showed different insertion torques with increases in cortical bone thickness, the best suitable screw design should be selected according to the different cortical thicknesses at the implant sites.

반응표면분석법에 의한 동충하초 첨가 증편 제조의 최적화

박금순,윤광섭,황성희,조현정,김정숙 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.4

To optimize the preparation process of Jeung-Pyun, an experiment was derived, using a central composite design, to find the optimal mixing conditions. The addition of Paecilomyces japonica powder, the volume of Tak-Ju and the second fermentation time were independent variables, with the pH, volume, color, sensory and texture properties of the Jeung-Pyun selected as response variables. As the Paecilomyces japonica powder and fermentation time were increased, the b values and volume after the second fermentation also increased. The color of the Jeung-Pyun became deeper with increases in the Paecilomyces japonica powder and fermentation time, and was deepest on the addition of 30% Tak-Ju. The pH increased with increasing fermentation time of the Jeung-Pyun, and on the addition of 3% Paecilomyces japonica rapidly increased more than with the other groups. The optimal mixing conditions for the best quality Jeung-Pyun, with restricted conditions above a b value of 3, a color intensity above 3, and a volume of 40㎖ and a pH of 4.02~4.04 after the second fermentation, were 4.0%, 20% and 45 mins for the Paecilomyces japonica powder, Tak-Ju and second fermentation time, respectively.

동종 골수이식을 시행받은 환자에서 폐색성 세기관지염에 의하여 발생한 자발성 기종격동과 피하 기종

이병환,이제중,이연경,안재숙,김여경,황호인,박무림,조상희,정익주,김형준 대한조혈모세포이식학회 2002 대한조혈모세포이식학회지 Vol.7 No.2

저자들은 만성골수성백혈병으로 동종 골수이식과 이식편 부전으로 인하여 추가적인 말초혈액 조혈모세포이식을 시행 받은 환자에서 만성 이식편대숙주질환과 그 폐 합병증인 폐색성 세기관지염에 동반된 자발성 기종격동과 피하 기종이 병발한 1예를 경험하였기에 이를 보고하는 바이다. Obstructive lung disorders following after allogeneic bone marrow transplantation (BMT) in association with graft- versus-host disease (GVHD) contribute significant morbidity and mortality. We report a case of a 28-year-old man who developed spontaneous pneumomediatinum and subcutaneous emphysema complicating bronchiolitis obliterans after allogeneic BMT. He received an allogeneic BMT for chronic phase of chronic myeloid leukemia. Five months after BMT, he was boostered by allogeneic peripheral blood stem cells from the same donor due to graft failure. One month after the boostering, chronic GVHD developed and were treated with cyclosporine and steroid. The patients developed spontaneous pneumomediatinum and subcutaneous emphysema secondary to severe bronchiolitis obliterans 4 months after boostering donor cells. The air-leak syndromes were recovered by conservative management, including high-flow oxygen.

저수축형 폴리머 콘크리트의 제조 및 물리·역학적 특성

연규석,이윤수,최동순,정경현,황진하 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

본 연구에서는 폴리머 콘크리트의 수축저감을 목적으로 수지량, 수축저감제함량과 S/a 비등을 변화시켜 경화수축의 변화와 강도 특성을 실험적으로 구명하였다. 경화수축량은 수치량이 105%일 때 보다 11.5%일 때, 즉 수지량이 증가할수록 커짐을 알 수 있었다. 수축저감제의 첨가에 따른 경화수축량은 감소함을 알 수 있었다. B10.5-SR10일 경우 수축저감제가 첨가되지 않았을 때 보다 약 30%, B10.5-SR20 일 경우 약 53%, B11.5-SR10일 경우 약 31%, B11.5-SR20 일 경우 약 47% 정도의 수축저감의 효과를 볼 수 있었다. S/a 비에 따른 경화 수축챨ㅇ은 S/a 60일 때 가장 적은 값을 보였으며, S/a 50, S/a 40 일때는 S/a60 일 때 가장 적은 값을 보였으며, S/a 50, S/a 40일 때는 S/a 60일 때 보다 각각 10%, 30% 정도 수축량이 증가함을 알 수 있었다. 압축 및 휨 강도특성은 수지량이 증가할수록 높아지고, 수축저감제의 첨가량이 증가할수록 낮아짐을 알 수 있었다. S/a 비에 따른 강도 특성은 압축강도와 휨강도 모두 S/a 비가 60일 때 가장 큰 값을 보였으며, S/a 비가 50,40 순으로 감소하였다. Many different polymer based concrete materials are known today, but the large setting or hardening shrinkage of polymer concrete is a problem to overcome in their practical applications. The setting shrinkage reaches about five to ten times the drying shrinkage of ordinary cement concrete, i.e, 50 to 60 ×10^4. This paper deals with a reduction in the hardening shrinkage of unsaturated polyester resin concrete which is treated with respect to shrinkage-reducing agent content, S/a ratio and catalyst content, and tested for length change during hardening, and flexural and compressive strengths. It is shown that the change of shrinkage-reducing agent content and S/a ration the length change of the unsaturated polyester resin concrete during hardening.