• 한국토양비료학회지
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• 제37권3호
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• pp.136-142
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• 2004

몬모릴로나이트와 일라이트를 대상으로 Hybrid 모델, 세슘흡착법, CEC와 결정분석 및 전원소분석으로 계산한 영구전하량을 상호 비교하였다. 격자구조 계산에 의하면 몬모릴로나이트와 일라이트의 영구전하는 각각 $71.82cmol\;kg^{-1}$, $14.20cmol\;kg^{-1}$로 나타났고. 세슘흡착법으로 구한 영구전하는 격자 구조의 계산 값과 $3.07-6.41cmol\;kg^{-1}$ 이하의 차이를 나타내었다. 따라서 세슘흡착법으로 구한 영구전하 량은 이론적 계산치와 일치함을 알 수 있었다. Hybrid 모델로 구한 영구전하 값은 세슘흡착법과 격자계산법에 비하여 약 5-13배가 과소평가되므로 이 모델을 점토광물의 영구전하 측정에 적용하기는 어려울 것으로 판단되었다. 암모늄 이온을 이용한 양이온교환용량 값의 경우 몬모릴로나이트는 세슘흡착법으로 구한 영구전하 값과 동일하였다. 한편 일라이트에서 영구전하의 이론적 계산치와 CEC 값이 차이를 나타낸 것은 CEC측정에 사용된 암모늄 이온이 층간에 고정된 칼륨이온을 치환시킴으로서 CEC가 상대적으로 높게 평가된 것으로 판단되었다. 이상의 결과를 종합하여 볼 때 영구전하의 함량이 높은 점토광물이나 토양에서 영구전하를 분리 정량하고자 할 때에는 세슘흡착법을 이용하는 것이 바람직할 것으로 판단되었다.

• Journal of Photoscience
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• 제6권3호
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• pp.91-96
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• 1999

Zeolites and microporouos materials continue to attract attention as novel hosts for photochemical reactions. Zeolities are attractive because of their ability to selectivity exchange and incorporate species within the void spaces and interconnecting channels, providing a spatial arrangement of molecules. Our research has primarily focused on intrazeolitic electron transfer from excited Ru(bpy)32+ in supercages of zeolite Y to a series of bipyridinium ions. In the Ru(bpy)32+ viologen-zeolite Y samples, the slowing of the back electron transfer from the bipyridinium radical cation to Ru(bpy)32+ allows for charge propagation via self exchange between diquat molecules. This provides an opportunity for permanent charge separation. When the migrating charge on the diquat radical within the zeolite reaches the surface, it can be transferred to a neutral viologen (PVS) in solution, resulting in permanent charge separation. The advantage of long-lived charge separation can be exploited for useful chemistry if suitable catablysts can be assembled on the zeolities. We have studied Ru(bpy)2 as water oxdiation catalysts. We have demonstrated that synthesis of RuO2 fibers on a zeolite via thermal decomposition of Ru3(CO)12 leads to the most active water decomposition catalyst reported to date. Because of the extensive interest of photochemical water reduction to H2, much is known about catalytic systems usin gone electron catalyst, and even more importantly, that no reaction of viologen occurred with H2 over this catalyst. The present challenge is to incorporate all these elements of the system into an architecture and we are examining zeolite membranes for this purpose.

• 한국토양비료학회지
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• 제24권4호
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• pp.241-247
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• 1991

제주도(濟州島) 한라산(漢拏山) 남사면(南斜面)에 toposequence를 이루고 있는 9개 토양통(土壤統)과 제주도(濟州島) 주요(主要) 토양군(土壤群)인 암갈색토(暗褐色土), 농암갈색토(濃暗褐色土), 흑색토(黑色土), 갈색삼림토(褐色森林土) 등을 대상으로 Extractable acidity, 치환성(置換性) Al, CEC, 염기포화도(鹽基飽和度), 영구전하(永久電荷), 변이전하(變異電荷), 변이전하비(變異電荷比) 등을 분석(分析)하여 제주도(濟州島) 대표토양(代表土壤)의 전하특성(電荷特性)을 Andic 특성(特性)에 따라 구명(究明)하고자 하였다. 저지대(低地帶)에 분포(分布)한 암갈색토(暗褐色土)인 월평(月坪) 및 용흥통(龍興統)에서는 치환성(置換性) 염기함량(鹽基含量), 영구전하량(永久電荷量), 염기포화도(鹽基飽和度)가 높은 반면에 Ext. acidity, CEC, 변이전하량(變異電荷量) 등이 비교적 낮아 CEC(양이온 합)/점토(粘土)가 150 cmol(＋)/kg 이하였고, 변이전하비(變異電荷比)도 0.80 이하였다. Allophone 또는 Al-유기복합체(有機複合體)가 주(主)가 되는 토양(土壤)에서는 Ext. acidity, CEC, 변이전하(變異電荷), 변이전하비(變異電荷比) 등이 매우 높고, 置換性 鹽基含量, 永久電荷, 염기포화도(鹽基飽和度)가 낮았는데, 이러한 경향(傾向)은 Al-유기복합체(有機複合體)가 주(主)가 되는 토층(土層)인 흑색토(黑色土)와 갈색삼림토(褐色森林土)의 A층에서 더욱 현저하였다. Ext. acidity, CEC($NH_4OAc$). CEC(양이온 합), 변이전하(變異電荷) 등은 유기탄소(有機炭素), Cp, Alp 함량 등과 고도(高度)로 유의(有意)한 상관관계가 있는데 그중에서도 Cp 함량(含量)과 가장 높은 상관관계가 있었다. Allophone이 주(主)가 되는 토양(土壤)에서는 염기포화도(鹽基飽和度)가 낮은데도 치환성(置換性) Al함량이 매우 낮으며 pH가 6.0 내외로 높은데, Al-유기복합체(有機複合體)가 주가 되는 토양(土壤)에서는 치환성(置換性) Al 함량이 비교적 높고 pH가 낮았다.

• 전기학회논문지
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• 제58권2호
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• pp.278-284
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• 2009

The global force and interaction body force density were evaluated in permanent magnets by using the virtual air-gap scheme incorporating the finite-element method. Until now, the virtual air-gap concept has been successfully applied to calculate a contact force and a body force density in soft magnetic materials. These force calculating methods have been called as generalized methods such as the generalized magnetic charge force density method, the generalized magnetizing current force density method, and the generalized Kelvin force density method. For permanent magnets, however, there have been few research works on a contact force and a force density field. Unlike the conventional force calculating methods resulting in surface force densities, the generalized methods are novel methods of evaluating body force density. These generalized methods yield the actual total force, but their distributions have an irregularity, which seems to be random distributions of body force density. Inside permanent magnets, however, a smooth pattern was obtained in the interaction body force density, which represents the interacting force field among magnetic materials. To evaluate the interaction body force density, the intrinsic force density should be withdrawn from the total force density. Several analysis models with permanent magnets were tested to verify the proposed methods evaluating the interaction body force density and the contact force, in which the permanent magnet contacts with a soft magnetic material.

• 한국입자에어로졸학회지
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• 제5권2호
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• pp.71-81
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• 2009

In this study, Nylon 6,6 electrospun (ES) nanofiber filter media were prepared at various spinning conditions. The ES filters tested had no intrinsic electrical charges. The ES filters were triboelectrically charged in the course of filter sample handling, and the charge was drastically decayed in a few hours. On the other hand, the corona charged melt blown filter media showed a permanent electrical charge. The electrical charge state of the ES filters was also examined by comparing collection efficiencies of ES filters for uncharged and charged aerosol particles.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권3호
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• pp.289-294
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• 2012

In this paper, the three-dimensional magnetic field created by non-periodic magnet arrays is calculated analytically. The analytical expression of the magnetic field is derived by using a magnetic charge model. The influence of ferromagnetic boundaries is formulated with an image method. Finally, we compare the results determined by analytical calculations to those from a finite element simulation.

• 한국토양비료학회지
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• 제26권3호
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• pp.160-171
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• 1993

Ultisol(필리핀의 Luisiana 토양)과 Alfisol(필리핀의 Maahas 토양)및 Inceptisol(한국의 용지통) 토양의 표면전하 특성을 전위차 측정법과 역적정법 및 이온흡착법 등의 세가지 방법으로 정량하였고 분석법간의 차이를 비교한 결과는 아래와 같다. 1. 이온흡착법(또는 CEC-AEC method)으로 구한 PZNC(point of zero net charge)값은 Luisiana토양과 Maahas 토양 및 용지통에서 각각 3.1, 2.2 및 2.9였다. 따라서 이들 토양의 자연 pH조건에서는 음전하를 보였다. 2. 전위차 적정법과 역적정법에서 구한 PZSE(point of zero salt effect)값은 Maahas토양 외의 두 토양에서 일치하였다. 3. PZNC값은 PZSE값에 비해 모든 토양에서 낮았는데 이는 영구음전하의 영향으로 생각되었다. 한편 Uehara and gillman(1980)의 이론에 의해 구한 영구음전하는 Luisiana 토양과 Maahas 토양 및 용지통에서 각각 2.6, 4.5 및 0.4me/100g로 pH 7에서 측정된 CEC중 상당히 적은 부분을 차지하였다. 4. 역적정법은 pH가 너무 높거나 낮을 때 전위차 적정법이 표면전하를 과다 평가하는 결점을 보완해 주었으나 여전히 이온흡착법에 비해 과대 평가하고 있어 영구전하의 영향이 큰 보통 토양에서는 이온흡착법의 사용이 나을 것으로 판단되었다.

• 한국염색가공학회지
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• 제35권1호
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• pp.20-28
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• 2023

In this study, TPU resin for coating was prepared by varying the mixing ratio of antistatic TPU and recycled TPU to manufacture permanent antistatic materials. The coated yarn was prepared by coating on the nylon yarn, and then the thermal, rheological, mechanical properties and antistatic properties were analyzed. In addition, antistatic properties and durability were confirmed after manufacturing UD fabrics using coated yarns. The mixing ratio of antistatic TPU and recycled TPU was most appropriate at 4:6, and the antistatic property had a surface resistance of 2.20 × 10⁹ Ω and a static charge of 398 V. In the coating process, the coating speed was most appropriate at 0.21 m/s, and the surface resistance of the UD fabric manufactured with the coated yarn manufactured under this condition was 6.80 × 10⁹ Ω and the static charge was 484 V. The UD fabric had a surface resistance of 7.21 × 10⁹ Ω and a static charge of 517 V after washing 10 times, and it was confirmed that the permanent antistatic property was excellent.

• 한국응급구조학회지
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• 제7권1호
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• pp.179-198
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• 2003

If see disaster administration system of our country, start in terms of is coping by countermeasure after four immediately after disaster occurrence many problems blessing with a sons by tribe and so on of link nature between formation, disaster administration complete charge utensil's absence, disaster charge manpower and budget be indicated and join. If examine improvement way accordingly, is as following ; Necessity of synthetic disaster administration system, Fire fighting formation's independence guarantee, Integration of fire fighting connection similarity business, Disaster administration's permanent establishment complete charge utensil's necessity, Disaster administration midautumn complete charge utensil at a metropolitan autonomous fire fighting system reorganization, Role division of labor between center and local government, Disaster administration professional human strength positivity, Disaster administration information system construction practical use, Equipment and improvement of budget state, Education public information for safety culture consciousness fixing, Internationalization of fire fighting business, globalization propulsion, Structure, member of rescue confrontation system and efficiency. Fire fighting environment is changing greatly, and fire fighting must become center to correspond to do confrontation that do one thing troble when produce disaster.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.963-967
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• 2007

Flywheel energy storage systems (FESS) have advantages over other types of energy storage methods due to their infinite charge/discharge cycles and environmental friendliness. The system has two radial bearings and one hybrid-thrust bearing. Thrust hybrid-type bearing use permanent magnet to relieve gravity load. The radial bearings were designed to provide sufficient force slew rate considering the unbalance disturbance at the operating speeds. In this paper, we will derive dynamic model of hybrid-type bearing using permanent magnet for thrust bearing and present simulation and stability of the model.