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.

先天性代謝異常症의 Pilot 硏究

黃泰周,崔榮倫,程文泰 全南大醫大 1985 전남의대학술지 Vol.22 No.4

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.

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.

브라켓 부착시 실런트 레진이 법랑질 탈회에 미치는 영향

윤영아,이기헌,황현식,홍석진 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.1

The purpose of this study was to evaluate the effects of a sealant resin on enamel demineralization in orthodontic bracket bonding. The forty eight extracted sound bovine teeth was subdivided into four groups and treated with Phase Ⅱ^(r) on the surface. Group 1 was not treated, Group 2 was acid etched with 37% phosphoric acid for 30 seconds, Group 3 was sealant applied after acid etching and Group 4 was resin paste applied after acid etching and sealant application. Each group was demineralized in artificial caries solution. Demineralized enamel depth was measured using by confocal laser scanning microscopy. The results were as follows. 1. The mean demineralized enamel depth was Group 1 (47.4㎛), Group 2 (61.8㎛), Group 3 (13.9㎛), Group 4 (8.2㎛). 2. The demineralized enamel depth was increased in Group 2 than Group 1 (p<0.05). 3. The demineralized enamel depth was reduced in Group 3 than Group1 and Group 2 with statistically significant differences (p<0.05). 4. Group 4 was very little demineralized. The results of the present study indicate that sealant application is useful for reducting enamel demineralization in orthodontic bracket bonding.

성남시 지역주민의 정신질환에 대한 태도 연구

고영,신수경,황태연,이충순,박연수,김인숙,황은숙,정원재 용인정신의학연구소 1999 용인정신의학보 Vol.6 No.1

폐Al dust와 폐주물사를 이용한 재료 개발

黃龍吉,金蓮洙,金宰逸 동아대학교 환경문제연구소 1986 硏究報告 Vol.19 No.2

The results of sulphuric acid leaching Aluminium dust and of making hydraulic-setting cement stone using Aluminium dust are as follows. 1. Sulphuric acid leaching efficient of Al is better when concentration of sulphuric acid is 200gr/ℓ, over 60℃, for lhours. 2. The aqueous solution recovered from sulphuric acid leaching of Aluminium dust contains Al^(+3) 13.5gr/ℓ and Fe^(2+) 1.65g/ℓ. 3. The hydraulic-setting cement stone making from mixture of cement, foundry sand, fly ash and Aluminium dust pulp(Na₂O·Al₂O₃) has more compressive strength comparing to other cement stones which make from mixture of cement, foundry sand and Aluminium dust pulp and mixture of cement and sand only. 4. Aluminium dust pulp has rapid hydraulic-setting effect in making cement stone.

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.

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.

치은연하 파절로 치조골 소실을 동반한 상악측절치에서 orthodontic extrusive remodeling후 임플란트 식립을 통한 심미수복 : 증례보고

황수연,손원준,한영철,배광식,백승호,이우철,금기연 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.1

심미적으로 중요한 전치부에서 단일 치아 임플란트를 이용한 보철수복은 임상의에게 새로운 도전과제 중의 하나가 되었다. 그러나 전치부에서 single-unit implant는 식립할 부위의 치조골 상태가 양호해야 하는데 치은연하 파절로 인해 치아 주위에 골 손실이 있는 경우 immediate implant는 심미적으로 문제를 야기할 수 있다. 따라서 본 증례는 "orthodontic extrusive remodeling"을 통해 파절치와 주위 조직을 교정적으로 정출시켜 임플란트 식립을 위한 연조직과 경조직을 증대시킨 후 임플란트 식립을 통해 상악측절치에서 성공적인 심미수복을 이룬 증례에 관한 것이다. The treatment of esthetic areas with single-tooth implants represents a new challenge for the clinician. In 1993, a modification of the forced eruption technique, called "orthodontic extrusive remodelling" was proposed as a way to augment both soft- and hard-tissue profiles at potential implant sites. This case report describes augmentation of the coronal soft and hard tissues around a fractured maxillary lateral incisor associated with alveolar bone loss, which was achieved by forced orthodontic extrusion before implant placement. Through these procedures we could reconstruct esthetics and function in a hopeless tooth diagnosed with subgingival root fracture by trauma.