문헌정보 분석을 통한 탄소 나노 튜브 기술 개발 동향 분석(Ⅱ)

홍태환 忠州大學校 2003 한국교통대학교 논문집 Vol.38 No.4

The current status of research and development on the nanotechnologies are reviewed by using literature information analysis. Especially, carbon nanotube(CNT) is one of the most important advanced materials for nanotechnology. Because of the extremely small dimensions, a large volume fraction of the carbon atoms are formed to the tubes-single or multi wall tube-, and this confers special attributes to these materials. The CNT appears to be a great potential for applications, such as emitter, field emission display(FED), secondary battery electrode, fuel cell, atomic force microscopy(AFM)/scanning tunneling microscopy(STM) tip, ultra small diodes, hydrogen storage cell, gas sensors, microwave devices, nano capsule, oil absorbers, nano composites, etc… in the near future for CNTs.

방폭공구 생산을 위한 제조 방법의 개발에 관한 연구

정태규,백고길,박성환,이소영,한복수 한밭대학교 산업과학기술연구소 1995 논문집 Vol.3 No.-

Arsenazo I-XAD-2 킬레이트수지를 이용한 U(VI) 이온의 분리 및 농축에 관한 연구

엄태윤,김인환,이창헌,강창희,이시은,이원,임재희 濟州大學校 基礎科學硏究所 1994 基礎科學硏究 Vol.7 No.1

Aresenazo I-XAD-2 킬레이수지를 합성하고 이 수지에 대한 U(VI)이온의 흡착 거동을 조사 검토하였다. 킬레이트수지는 Arsenazo I 킬레이트제와 Amberlite XAD-2의 디아조늄짝지움 반응에 의해서 합성하였으며 원소 분석법과 적외선 분광법으로 확인하였다. U(VI)이온흡착의 최적 조건을 찾기 위해서 pH, U(VI) 이온농도와 진탕 시간에 관해서 조사하였다. U(VI)이온에 대한 킬레이트수지의 전체 흡착능은 pH 4.0∼4.5 범위에서 0.39mmol U(VI)/g resin이었고, pH값이 증가함에 따라 흡착능이 증가하였다. Arsenazo I-XAD-2 킬레이트 수지에 대한 U(VI)이온의 흡착 메카니즘은 U(VI)이온과 H+ 이온 사이의 경쟁반응임을 확인하였다. 컬럼법으로 구한 U(VI) 이온의 돌파점 부피와 전체 흡착능은 각각 600ml, 0.38mmol U(VI)/g resin 이었다. 3M HNO₃와 3m Na₂CO₃의 탈착용액을 사용하여 구한 회수율은 90∼96%였다. 따라서 본 연구에서는 합성한 Arsenaso I-XAD-2 킬레이트수지는 자연수 바닷물 중에 함유된 U(VI)이온의 분리와 농축에 매우 유용함을 알았다. Some sorption behaviors of U(VI) ion on Arsenazo I-XAD-2 chelating resin were investigated. This chelating resin was synthesized by the diazonium coupling of Amberlite XAD-2 resin with Arsenazo I chelating reagent and characterized by elementary analysis method and IR spectrometry. The optimum conditions for the sorption of U(VI) ion were examined with respect to pH, U(VI) ion concentration and shaking time. Total sorption capacity of this chelating resin on U(VI) ion was 0.39 mmol U(VI)/g resin in the pH range of 4.0∼4.5. This chelating resin was showed increased sorption capacity on the increased pH value. It was confirmed that sorption mechanism of U(VI) ion on the Arsenazo I-XAD-2 chelating resin was competition reaction between U(VI) ion and H+ ion. Breakthrough volume and overall capacity of U(VI) ion measured by column were was 600ml and 0.38 mmol U(VI)/g resin, respectively. The desorption of U(VI) ion was showed recovery of 90∼96% using 3M HNO₃and 3M Na₂CO₃as a desorption solution. The separation and concentration of U(VI) ion from natural water and sea water was performed successfully by Arsenazo I-XAD-2 chelating resin.

Laser Doppler flowmeter를 이용한 치수혈류 측정

반태환,이재상,김성교 大韓齒科保存學會 1999 Restorative Dentistry & Endodontics Vol.24 No.4

문헌정보 분석을 통한 탄소나노튜브 기술 개발 동향 분석(Ⅰ)

홍태환 忠州大學校 2002 한국교통대학교 논문집 Vol.37 No.4

The current status of rsearch and development on the nanotechnologies are reviewed by using literature information analysis.

配當政策에 있어서 代替原價利益 情報의 有用性

金台煥 嶺南大學校附設 社會科學硏究所 1990 社會科學硏究 Vol.10 No.2

胎兒 腹圍 및 頭圍의 超音波 測定

李星煥,李台鎬 慶北大學校 醫科大學 1982 慶北醫大誌 Vol.23 No.2

1981年 4月부터 1982年 3月까지 1年間 慶北大學校 醫科大學 附屬病院 産婦人科에서 産前管理를 위하여 來院한 患者中 最終月經이 正確한 正常姙婦中 超音波斷層診斷裝置로 兒頭圍 및 腹圍를 測定한 例中 測定日부터 3日以內에 分娩한 128例의 胎兒腹圍 測定値 및 兒頭圍測定値와 兒體重 및 胎齡과의 相關關係 및 이들 超音波測定値와 生後 實測値를 硏究檢討한 바 그 成績을 아래와 같이 要約한다. 가장 높은 相關關係는 兒腹圍와 兒體重間에서 觀察할 수 있었고 相關係數는 γ=0.98, (p<0.005)이었다. 兒腹圍와 胎齡과의 相關은 相關係數 γ=0.93,(p<0.995)로 높은 相關을 보였다. 兒頭圍와 兒體重과의 相關은 相關係數 γ=0.94,(p<0.005)로 역시 높은 相關을 보였다. 兒頭圍와 胎齡과의 相關은 가장 낮았고 相關係數는γ=0.91, (p<0.005)이었다. 胎兒腹圍의 超音波測定 平均値와 實測平均値의 差및 胎兒頭圍의 超音波測定 平均値와 實測平均値의 差는 各各 0.85cm 및 1.43cm 로 兩者 共히 實測値와 매우 近似하였으나 胎兒腹圍 묘사가 보다 正確하였다. 以上의 成績으로 超音波 兒頭圍測定은 正確할 뿐만 아니라 胎兒體重 및 胎齡을 豫測하는데 매우 優秀한 方法이라 思料되며 兒頭圍測定 또한 그 成績은 前者에 比하여 若干 못미치나 日常臨床에서 利用할 充分한 價値를 지닌 것으로 생각된다. Studies were made whether or not correlation take place between fetal body weight and gestational age and prenatal ultrasonic fetal head circumference as well as fetal abdominal circumference measurement with 128 cases of gravida who were delivered within 3 days after fetal sonometry. All gravidas were randomly selected having regular menstrual period who visited prenatal clinic from April 1981 to March 1982. Results summarized were as follows. The highest correlation observed was between fetal abdominal circumference measurement and fetal body weight revealed correlation coefficiency, r=0.98(p<0.005) and mean standard deviation of ±339.4gm. Correlation between fetal abdominal circumference and gestational age showed, r=0.93(p<0.005) and mean standard deviation of gestational age, ±2.4 week. Correlatio between fetal head circumference measurement and fetal body weight indicated r=0.94(p<0.005) and mean standard deviation of body weight was ±400.9gm. The least correlation observed was between fetal head circumference measurement and fetal gestational age, r=0.91(p<0.005) and mean standard deviation of ±2.5 week. The difference between mean ultrasound fetal abdominal circumference measurement and actual measurement was 0.85cm with minor difference and that of feral head circumference was 1.43cm respectively. It was suggested that prediction of fetal body weight was more accurate with sole fetal abdominal circumference measurement than fetal head circumference measurement. Even though measurement of fetal head circumference revealed less accurate than feral abdominal circumference measurement in predicting fetal body weight but results indicated that it was worth-while and convenient for estimation of fetal maturity on routine obstetic prenatal care.

비용ㆍ편익 분석을 중심으로 한 중수도 시설의 처리방법별 적정규모선정

노상환,민동기,송영일,박태욱,박주양 한양대학교 환경공학연구소 2000 環境科學論文集 Vol.21 No.-

미래의 안정적인 수자원 확보를 위한 수요관리방안인 중수도 시설 설치 시 발생하는 비용과 편익의 현재가치를 이용하여 처리방식별로 중수도 시설의 경제성 분석을 하였다. 사회적 편익을 고려하였을 경우 중수도 시설규모가 300㎥이상의 1일 처리용량의 경우 경제성이 있는 것으로 나타났다. 그러나 사적편익을 고려하였을 경우에는 사회적 편익에서 고려된 환경비용절감등의 여러 외부 편익이 포함되지 않아 중수도 시설에 의한 편익이 작아지게 된다. 따라서 사적편익만을 고려할 경우에는 대체로 경제성이 있는 중수도 시설의 규모는 사회적 비용을 고려하였을 경우 보다 커진다. Water reuse is a control method of water demand to steadily assure water resources in the future. Economical efficiency of wastewater reuse plants with various treatment processes was studied using the present value of cost-benefit. When social benefits are considered, the capacity of 300㎥/ day was found to be economically effiecient. However, when private benefits are considered, the social benefit of wastewater treatment plant decreases because the private benefits do not include environmental expenses and other benefits which are included in social benefits. Therefore, when the private benefits are only considered, the economically efficient capacity of the wastewater reuse plant will be higher than that considering social expenses.

Inx Ga₁-xAs/InP 비대칭 이중 양자 우물의 전자 부띠에 대한 연구

김태환 光云大學校 1995 論文集 Vol.24 No.-

Shubnikov-de Haas (s-dH) and Van der Pauw Hall-effect measurements of In? Ga₁?As/InP double quantum wells grown by metalorganic chemical vapor deposition have been carried out to demonstrate the existence of the two-dimensional electron gas (2DEG) in the double quantum wells. Transmission electron microscopy measurements showed that a InAs and a In0.53 Ga0.47As quantum wells were separated by a In0.25Ga0.75As potential barrier in an active region. The results for the S0dH data and quantum Hall-effects at 1.5K have demonstrated clearly the existence of a 2DEG in quantum well. The fast Fourier transformation results for the S-dH data clearly indicate the occupation of two subbands in the coupled by a self-consistent method taking into account exchange-correlation effects. The 1st excited subband wave functions in the asymmetric double quantum well is strongly coupled over both InAs and In0.53Ga0.47As wells.

변조도핑된 Inx Ga₁_x As/In₁_y As 계단형 양자우물에 대한 전자 부띠에 대한 연구

김태환 광운대학교 기초과학연구소 1997 기초과학연구소논문집 Vol.26 No.-

Shubmikov-de Haas(S-dH) and Van der Pauw Hall-effect measurements on In?Ga??As/In?Al??As one-side-modulation-doped step quantum wells were carried out to investigate the electrical properties of a free electron gas and to determine the electronic subband energies and the corresponding wave functions in the In?Ga??As/In?Al??As step quantum wells. The angular dependent S-dH measurements at 1.5 K demonstrated clearly the existence of a quasi-tow-dimensional electron gas in the In?Ga??As step quantum wells, and the fast Fourier transform results for the S-dH data indicated clearly the occupation by that gas of two subbands with electron carrier densities of 1.19×10?? and 2.7×10?? cm?? for the first excited and the ground subbands, respectively. The electronic subband energies and the wave functions in the In?Ga??As/In?Al??As step quantum wells were calculated by a self-consistent method taking into account exchange-correlation effects together with the strain and nonparabolicity effects. These results can help improve understanding for the application of In?Ga??As/In?Al??As step quantum wells in optoelectronic devices.