• 과학교육연구지
• /
• 제33권2호
• /
• pp.317-320
• /
• 2009

부피 측정법을 이용하여 산 염기 적정 실험에서 중화점을 측정할 때, 나는 용액의 부피 변화에 대한 한국 대학생들의 개념을 조사하였다. 이 연구에 의하면, 대부분의 대학생들은 산 염기 적정 동안 중화반응에 의해 물이 생성되기 때문에 부피가 증가한다는 오개념을 갖고 있었다. 그러나 이것은 용액에 있는 염에 의한 효과를 무시한 것이기 때문에, 부피 변화를 설명하는데 충분하지 않다. HCl/NaOH 중화반응 동안 용액의 부피 증가를 설명하기 위해, 나는 생성된 NaCl의 부분 몰부피를 계산하였다. 실험 결과와 계산된 부분 몰부피를 비교할 때, 나는 부피 증가의 주요 효과는 HCl/NaOH 중화반응 동안 생성된 NaCl의 부분 몰부피 때문이라는 것을 밝혔다. 여기서 산 염기 중화 적정 동안 용액의 부피 변화에 대한 오개념을 줄이기 위해, 나는 부분 몰부피의 개념을 대학생들에게 도입하도록 제안한다.

• 한국염색가공학회지
• /
• 제14권5호
• /
• pp.294-301
• /
• 2002

The effects of various parameters on partial decoloration of cotton dyeings using discharge reactive dye were investigated. The decoloration of dyed cotton fabrics with varying pH were very sensitive below 100g/1 of amount of potassium carbonate. Our results did indicate any significant changes in color when the amount of Rongalite C in reducing liquor was increased 10g/l to 200g/l. The steaming time had significant effects on fade-out, with an steaming time of 3~5 min. being sufficient for deceleration build up. The change of color below $130^\circ{C}$ was not significant and it only become evident above $140^\circ{C}$. The additional color changes did not cause by washing under suitable concentrations of oxidation and neutralization agents. The decoloration treatment did not affect the mechanical property of cotton fabrics such as tensile strength.

• 자원리싸이클링
• /
• 제12권2호
• /
• pp.3-10
• /
• 2003

PCB (Printed Circuit Board) 산업에서 배출되는 산성 염화동 폐액으로부터 농약원제로 사용이 가능한 고순도의 copper oxycloride를 제조하였다. PCB제조 산업은 구리 소재를 이용한 전자 부품 가공 산업으로서 제조 공정인 부식 과정에서 다량의 구리가 함유된 에칭 폐액이 발생한다. 환경과 경제적인 측면에서 폐액으로부터 구리성분을 재회수하는 기술의 개발은 매우 중요하다. 본 연구에서는 가성소다로 폐액을 중화하여 copper oxychloride를 회수하는 공정의 반응 조건을 확립하였다. 반응 온도 2$0^{\circ}C$-4$0^{\circ}C$, pH 5-7 사이에서 순수한 copper oxychloride제조가 가능하였고 이때 수득율은 95% 이상이었다. 생성물의 물리적 특성을 SEM, XRD, TGA, ICP 그리고 원자 흡수 분광기를 사용하여 분석하였다.

• Journal of Chest Surgery
• /
• 제13권1호
• /
• pp.13-20
• /
• 1980

Heparin would have been used for preventing clotting of blood during extracorporeal circulation and subsequent use of protamine sulfate and made possible the neutralization of heparin. This procedure has been adopted for eliminating one of the great causes of bleeding, especially in cardiac surgery. In this experiment, the hypocoagulability of blood induced by heparin followed by neutralization with treatment of protamine sulfate were estimated by the Lee-White clotting time [CT], partial thromboplastin time [PTT] and protamine titration test. The results were as follows: 1] Comparison of clotting time between the heparinized [2.0 mg/kg] and non-heparinized dogs was done using CT and PT`I` of the blood. In heparinized group [Group I], the CT lasted infinitively and prolongation of PTT [4 times than normal] until 60 minutes. The CT [2 times] and PTT [3 times] has been shortened after 90 minutes, however they returned to normal limit level within 180 minutes. 2] The determination of appropriate ratio of heparin and protamine In vivo were performed. The group II [heparin 2.0 mg/kg, protamine 1.0 mg/kg] revealed rapid decrease of CT and PTT, but returned to normal after 120 minutes. The group III [heparin 2.0 mg/kg, protamine 2.0 mg/kg] returned rapidly to normal within 15 minutes. The group IV [heparin 2.0 mg/kg, protamine 3.0 mg/kg] recovered its normal level after 60 minutes. The group V [heparin 2.0 mg/kg, protamine 4.0 mg/kg] recovered its normal level after 90 minutes. 3] In the combined experimental study In vivo and vitro, the protamine titration test was done using the dog which were given 2.0 mg/kg and 3.0 mg/kg of heparin, respectively and coagulation time were checked after 15, 30, 60 and 120 minutes. The complete neutralization was showed to be heparin-protamine ratio of 1:1 to 1.5. 4] In vitro study, fresh blood was drawn into known amount of heparin content [20, 40, 60 and 100/ug per 1 ml of blood] syringe, thereafter protamine titration test was done. In all cases, the complete neutralization was found in heparin-protamine ratio of 1:0.85 to 1.5. 5] It was found by the present experiment that the ideal heparin-protamine ratio was 1:1 within 60 minutes and 1:0.5 after 60 minutes for avoiding the serious side effect due to overadministration of protamine sulfate.

• 대기
• /
• 제24권1호
• /
• pp.49-68
• /
• 2014

This study analyzed atmospheric conditions for the convergent cloud band (Cu-Cb line) in developing stage and its neighbouring convections formed over the East Sea on 1 February 2012, by using synoptic, satellites data, and WRF numerical simulation output of high resolution. In both satellite images and the WRF numerical simulation outputs, the Cu-Cb line that stretched out toward northwest-southeast was shown in the East Sea, and cloud lines of the L mode were aligned in accordance with the prevailing surface wind direction. However, those of the T mode were aligned in the direction of NE-SW, which was nearly perpendicular direction to the surface winds. The directions of the wind shear vectors connecting top winds and bottom winds of the moist layers of the L mode and the T mode were identical with those of the cloud lines of L mode and T mode, respectively. From the WRF simulation convection circulations with a convergence in the lower layer of atmosphere and a divergence above 1.5 km ASL (Above Sea Level) were identified in the Cu-Cb line. A series of small sized vortexes (maximum vortex: $320{\times}10^{-5}s^{-1}$) of meso-${\gamma}$-scale formed by convergences was found along the Cu-Cb lines, suggesting that Cu-Cb lines, consisting of numerous convective clouds, were closely associated with a series of the small vortexes. There was an absolute unstable layer (${\partial}{\theta}/{\partial}z$ < 0) between sfc and ~0.3 km ASL, and a stable layer (${\partial}{\theta}/{\partial}z$ > 0) above ~2 km ASL over the Cu-Cb line and cloud zones. Not only convectively unstable layers (${\partial}{\theta}_e/{\partial}z$ < 0) but also neutral layers (${\partial}{\theta}_e/{\partial}z{\approx}=0$) in the lower atmosphere (sfc~1.5 km ASL) were scattered around over the cloud zones. Particularly, for the Cu-Cb line there were convectively unstable layers in the surface layer, and neutral layers (${\partial}{\theta}_e/{\partial}z{\approx}=0$) between 0.2 and ~1.5 km ASL over near the center of the Cu-Cb line, and the neutralization of unstable layers came from the release of convective instability.

• 융복합기술연구소 논문집
• /
• 제12권1호
• /
• pp.19-23
• /
• 2022

Interest in hydrogen production to respond to climate change is increasing. Until now, hydrogen has been mainly produced through the SMR (Steam Methane Reforming) process using natural gas. A large amount of CO₂ is emitted in the hydrogen production process through SMR, and the gas flow including CO₂ generated in the SMR process has different characteristics for each emission source, so it is important to apply a suitable CO₂ capture process. In the case of PSA tail gas or synthesis gas, the applicability of an amine-based process has been confirmed or demonstrated close to a commercial level. However, in the case of the flue gas generated from the reformer, it is still difficult to apply the conventional amine-based process because the partial pressure of CO₂ is relatively low. Energy-saving innovative absorbents such as phase separation absorbents can be a solution to these difficulties.

• 대한수의학회지
• /
• 제32권1호
• /
• pp.83-90
• /
• 1992

소 설사병 바이러스 구조단백에 대한 단크론항체를 작성하여 혈청중화시험, 전기영동, 면역침전반응을 이용하여 분석하였던 바 다음의 결과를 얻었다. 중화능력이 있는 항체의 경우 56K내지 54K의 구조단백에 대응하였다. 그외 중화력을 나타내지 않는 항체는 45K와 36K의 바이러스 항원과 대응하였다. 순수정제된 바이러스의 전기영동 분석결과 12종 이상의 바이러스 단백성분이 구조단백질로서 검출되었으며 중화능력을 나타내는 항체를 이용한 면역침전 결과는 이들의 존재를 뒷받침하였다. 중화단백성분의 세포내 전구물질의 검출은 불가능하였으나 방사선동위원소 부착즉시 세포배지에서 바이러스의 존재를 확인할 수 있었다. Staphylococcus aureus $V_8$효소를 이용한 항원의 부분소화 분석결과 45K와 36K의 바이러스 항원은 서로 상관이 있는 것으로서 입증되었다.

• 펄프종이기술
• /
• 제35권2호
• /
• pp.18-25
• /
• 2003

The adsorption of co-cationic dual polymer system was investigated as was the fiber dispersion stability of a paper stock suspension. Polyaluminum chloride(PAC) and polyamidoamine epichlorohy-drin(PAE) polymers were used as wet-end additives. The adsorbed amounts of PAE polymer in a wet stock were measured by using polyelectrolytic PCD titration. The sheet forming experiments were carried out in a standard handsheet machine. Fiber dispersion stability and relative retention were evaluated in terms of M/K non-uniformity index and sheet basis weight, respectively. The PAE polymer adsorption of Langmuir-isothermal type decreased with increasing PAC addition level. The combination of the two cationic polymers presumably exerts a site-blocking effect by the low molecular weight PAC which gives a partial charge neutralization at a minimum level of addition. From a thermodynamic view point of PAE adsorption, an increase in adsorption entropy and a decrease in train number suggests that the PAR polymer has an extended conformation structure that potentially leads to an enhancement of the fiber dispersion stability. This conclusion is supported by handsheet experiments that examined the PAC-PAE dual polymer effects on the sheet formation and retention.

• 공업화학
• /
• 제10권6호
• /
• pp.871-875
• /
• 1999

인산형 양이온교환수지 특성 계산과, 이온교환수지의 전위차 적정곡선의 형태에 따른 정확한 이온교환용량을 결정할 수 있는 방법을 알아보았다. 이온교환수지는 divinylbenzene 4%로 가교화된 polystyrene 공중합체를 인산화한 것으로 이온교환용량이 5.7 meq/g이다. 인산형 양이온교환수지는 직선의 식으로 설명할 수 있었고, 직선 기울기로부터 적정시 zero중화와 완전중화사이의 평형상수 음의 대수(pK) 값의 차인 ${\Delta}pK$의 값을 구할 수 있었으며, ${\mathit{x}}=0.5$에서 얻어진 실험 및 이론의 pK값이 잘 일치하는 것을 알 수 있었다. 이온교환수지의 전위차 적정곡선은 NaOH나 $Ba(OH)_2$로 적정할 때 ${\mathit{x}}$의 변화에 따른 pK의 실험 값과 계산 값이 잘 일치하는 것을 알 수 있었다. 전위차 적정곡선의 변곡점은 원자가가 1가인 이온보다는 2가 이온이 크게 변화되는 것을 알 수 있었으며, g값과 도함수 ${\partial}pH/{\partial}g$의 관계를 Lorentz함수로서 나타내어 더욱 정확한 이온교환용량을 결정할 수 있었다.

• 수산해양교육연구
• /
• 제18권2호
• /
• pp.85-97
• /
• 2006

With extension of national jurisdiction over coastal living resources, new dimensions and objectives should be added to international cooperation in distant-water fisheries concepts. For distant-water fishing nations, Korea, joint exploitation of these resources is today considered not only as a way of producing additional income opportunities, but first of all as at least a partial solution to neutralization of harvesting limitations imposed on them in traditionally exploited fishing grounds.This paper explores the development of Korean distant-water fisheries agreements and reviews the various types of agreements currently in place and discusses the future of Korean distant-water fisheries agreements with third countries. The relationship between coastal States and fishing fleets from non-adjacent countries has been transformed since the 1980s. This was primarily a result of the declaration of Exclusive Economic Zones(EEZs) by many coastal states in the years leading up to the close of the negotiations of the UNCLOS in 1982. Significantly, by recognizing the right of coastal states to determine how their waters were to be exploited, UNCLOS provided a legal basis and economic motivation for the negotiation of access agreements between coastal states and distant-water fishing nations, KoreaThere is a real danger that Korean distant-water fisheries agreements could and do result in the adverse environmental impacts experienced in Korean coastal waters being transferred to third country water and consequently creating socio-economic problems for these third countries. Korean distant-water fisheries agreements with third countries have the potential to be a force for good if they are well managed and if the principals that will be applied within Korean coastal waters, through the reform of the distant-water fisheries policy, are applied equally upon third country waters.