고감도 Ames test(microsuspension assay)와 임파구 소핵시험법을 이용한 변이원성에 관한 조사 연구

안지영,김해준,윤인재,성영자,김영환,장영철 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.3

In order to evaluate the mutagenic effects of extractable indoor air pollutants (organic matters), we measured the mutagenic activities by sensitive microsuspension Ames test using new tester strains (YG 1024 and YG 1029). And additionally to evaluate the mutagenic effects on vital cell, we examined the frequencies of micronucleus appearing in lymphocytes from dye handling workers and controls. This study was conducted from Jan. to May, 1995. The extractable indoor air pollutants were collected by low volume air sampler in a general office room and 3 of dye handling factories. And the environment of general office room divided into 3 different groups according to the type of room heaters. To determine the frequencies of micronucleus appearing in lymphocytes, we sampled peripheral venous blood from 20 of dye handling workers and 20 of controls, and cultured, and then examined the lymphocytes. The results obtained were as follows: 1. The indirect mutagenic activities of extractable organic matters from suspended particulates collected in a general office room were higher than the direct one. 2. The strain YG 1024 was the most sensitive, and the increasing order of test strains that showed higher number of revertant were YG 1024, YG 1029, TA 100, TA 98. 3. In the general office room, the room using kerosene heater showed the highest mutagenecity, and the next was buthan gas heater, and non-heating room in order. 4. The mutagenic effects of suspended particulates in dye handling factories on the strain YG 1024 was 1.2 times higher than YG 1029. 5. The frequencies of micronucleus appearing in lymphocyte of the circulating blood of dye handling workers and the control were 5.65±2.97‰ and 4.65±0.97‰, respectively. And the difference was statistically significant.

경골 Pilon 골절 후 가동술(mobilization)과 복합운동 적용사례 : 증례 보고

안호정,전범수,박지환 대한정형도수치료학회 2006 대한정형도수물리치료학회지 Vol.12 No.1

Purpose: The purpose of this study was to evaluate the effects of mobilization application for the lower extremity after fibula Pilon fracture operation patient. Methods: The subjects was 62 years old male who was injury of Lt. fibula shaft Fx., 3 cuneiform & cuboid Fx., 2.3.4 metatarsal bone Fx.. We were compared to result of physical therapy between pre and post exercise for 2weeks. Results: The results of this study were summarized below; The mobilization application of the Lt. lower extremity was significantly differences of the ROM at pre and post therapy after 2 weeks, especially in knee flexion (40˚). The increased of accessary movement was evaluated to increased of the physiologic movement about the joints of the lower extremity. Conclusion: We consider that factors of therapy result were not only fracture types, operation and reduction methods for the fibula Pilon fracture but also the ability of physical therapist's manual techniques.

Zeolite Synthesis from Coal Bottom Ash for Recycling as an Absorbent of Heavy Metals

Ahn, Ji Whan,Han, Gi Chun,You, Kwang Suk,Um, Nam Il,Cho, Hee Chan Trans Tech Publications, Ltd. 2006 Materials science forum Vol.510 No.-

<P>This study focused on the synthesis of zeolite from coal bottom ash and the CEC assessment of synthesized products. To that end, zeolificaion tests were carried out at four temperature levels (80, 100, 120, 150oC) and five NaOH concentration levels (1, 2, 3, 4, 5M) by the alkali hydrothermal method. Consequently, NaP1, hydroxy-sodalite, and tobermorite were produced from coal bottom ash. NaP1 with an excellent cation exchange capability had a high crystallinity at below 2M NaOH and 120 oC; and the maximum CEC value was 160meq/100g at 2M NaOH and 120 oC under the given conditions.</P>

Characteristic of Cu and Pb Leaching Behavior of Municipal Solid Waste Incineration Bottom Ash

Ahn, JI-Whan,Cho, Hee-Chan,Han, Gl-Chun,You, Gwang-Suk,Um, Nam-Il 한국암반공학회 2006 Geosystem engineering Vol.9 No.1

The leaching test with municipal solid waste incinerator (MSWI) bottom ash was studied in order to investigate leaching property of Cu and Pb and stabilization. Also carbonation reaction was processed in MSWI bottom ash and conform their effect on the leaching of Cu and Pb for maximization of weathering process. It was sampled one size of bottom ash lower than 0.15mm. In the leaching test of bottom ash (2 types) was resulted that leaching volume of Cu and Pb was high, although. Also dissolved Cu and Pb was investigated as a change of pH. Through interaction of $CO_2$ with bottom ash (carbonation), maximize stabilization of Cu and Pb leaching. As a result, leaching volume of Cu and Pb was decrease.

Ceramic Bubble Plate를 이용한 $C_2H_5OH-Ca(OH)_2-CO_2$계의 탄산칼슘 생성 및 결정화 연구

Ahn, Ji-Whan,Park, Chan-Hoon 한국자원리싸이클링학회 1996 資源 리싸이클링 Vol.5 No.3

탄산칼슘의 다형 제어를 목적으로 합성 음료, 의약품 등으로서도 폭넓게 이용되고 있는 ${C_2}{H_4}{OH}$계에서 수산화칼슘을 현탁시키고 감미제, 의약품 등의 용도로서도 이용되고 있는 에틸렌글리콜을 첨가하면서 탄산칼슘 생성 및 탄산칼슘 다형결정화 특성에 대해 연구하였다. 세라믹 bubble plate를 부착 제작한 반응기를 사용하여 $CO_2$gas와 반응 진행시 전기전도도의 연속 측정을 통해 변화시점에서 일부 현탁액을 분리 분말화하여 X선 회절 및 전자현미경을 통해 중가 생성물과 이들이 각각 Vaterite, Aragonite, Calcite로 전이됨을 확인하였다. ${C_2}{H_4}{OH}$에 대한 에틸렌글리콜 첨가를 10 vol%로 하여 500ml의 반응 현탁액에 10~50g의 수산화칼슘 첨가 변화에 따른 생성물을 조사하였다. 결정화단계에서 수산화칼슘 10g 첨가시를 제외하고는 모든 조건에서 겔화(gelation)가 일어나며 그 생성 유지시간은 수산화칼슘 양이 많아질수록 짧아짐을 관찰할 수 있었다. 상온 상압하에서 생성되기 어려웠던 Vaterite가 $Ca(OH)_2$의 30g 첨가반응계에서 구형으로 생성됨을 확인할 수 있었다. 이는 칼슘계, 흡착제 등의 가능성을 부여한 복합재료로서의 Vaterite 합성을 상온 상압화에서${C_2}{H_4}{OH}$ 계에서 다형제어 할 수 있음을 보여주었다. 탄산칼슘의 동질이상중 Vaterite는 준안정상이고 분말화 과정에서 이미 Calcite로 전이되기 쉬우나 G5 glass filter와 vacuum drier를 사용하여 안정적인 구형의 Vaterite을 확인할 수 있었다. C,H,OH system is widely used for producing synthetic beverages and pharmaceuticals. Calcium hydroxide suspension was used to callhol the morphology of calcium carbonate, and the charactenstics of the formahan and crystsllizatian of calcium cilrbonate by adding ethylenc glycol were determined A reaclor was made with attaching a ceramic bubble plate, and lhe eleclrical conductivity was continously monitored during the rcaction with CO, gas. A part of the suspension was separated and powdered at the transition point. XRD and electron microscopic observation showed that the intermedmte and final products were vilterite, ;~r;lganite and calcite. In this study, the volumc of the ethylene glycol added to CH,OH was fixed a1 10 vol\ulcornerh. The valumc of the suspension was 500 ml, and the changes oi characteristics were shdied along with variims cnntents(l0-50 g) of calcium hydroxide. Except m the case of 10 g of calcium hydroxide at the crystallization stagc, all of products showed gelation. Tne marc the calcium hydroxide the shorter the formation time. Alsa. the farmalion of spherical valcrile ivas obsemcd when 30 g Ca(OH), was added. Tne vaterite(a compound material) can bc synthesised under alnbienl pressure and lempcmhre m a C,H,OH system by morphology control. Even though the vateritc was meta-stable phasc and could bc changed to calcitc easily, the stable and spherical vateritc was observed by using G5 glass fillers and vacuum dricrs.

Stabilization Behavior of Heavy Metals Derived from Wastes on Cementitious Minerals and Hydrates

Ahn, Ji Whan,You, Kwang Suk,Han, Gi Chun,Cho, Kye Hong Trans Tech Publications, Ltd. 2006 Materials science forum Vol.510 No.-

<P>In this paper, the application of wastes as raw materials to cementitious mineral was investigated. A rolling slag, which contains plenty of heavy metals, was used as a raw material to synthesize calcium sulfoaluminate. It was found that the suitable burning temperature of CSA clinker is between 1,250°C and 1,300°C, and the residual content of heavy metals in the CSA clinker turned out sequentially as Cu, Zn, Cr, and Pb. According to the results of the investigation, it is believed that a large amount of the Cu, Zn and Cr present in the raw materials were fixed in the CSA clinker formed during the sintering process. It was further found that the distortion of the crystal morphology of hydrate, which was ettringite, took place according to the substitution of heavy metals during the hydration process.</P>

Synthesis of Precipitated Calcium carbonate in Ca(OH)₂-CO₂-H₂O System by the Continuous Drop Method of Ca(OH)₂ Slurry

Ahn, Ji-Whan,Lee, Jae-Sung,Joo, Sung-Min,Kim, Hyung-Seok,Kim, Jong-Kuk,Han, Choon,Kim, Hwan The Korean Ceramic Society 2002 한국세라믹학회지 Vol.39 No.4

Experiments were conducted to investigate the synthesis characteristics of Precipitated Calcium Carbonate(for short PCC) in Ca(OH)$_2-CO_2-H_2O$ system by the continuous drop method of Ca(OH)$_2$ slurry into the solution containing $CO_2$(aq). When the flow rate of $CO_2$(g) increases and the concentration of Ca(OH)$_2$ slurry become low, the absorption rate of $CO_2$(g) become faster than the dissolution rate of Ca(OH)$_2$. Consequently, the growth of the calcite crystal plane is facilitated resulting in synthesis of $1.0{\mu}m$ of rhombohedral calcite. On the other hand, when the flow rate of $CO_2$(g) decreases and the concentration of Ca(OH)$_2-CO_2-H_2O$ slurry become high, new nuclei is created along with the crystal growth resulting in synthesis of $0.1{\mu}m$ of prismatic calcite. Maintaining 1.0wt% of Ca(OH)$_2-CO_2-H_2O$ slurry, 120 drops/min of drop rate and $25^{circ}C$ of temperature, the shape of PCC shows colloidal and spherical agglomerate at 100 mL/min of the flow rate of $CO_2$(g); the mixture of rhombohedral and plate-shaped calcite, at 200∼500 mL/min. Therefore, as the flow rate of $CO_2$(g) increases, the shape of PCC changes from colloidal and rhombohedral calcite to plate-shaped calcite. Maintaining 500 mL/min of the flow rate of $CO_2$(g), 120 drops/min of the drop rate of Ca(OH)$_2$ slurry, and $25^{circ}C$ of temperature, the shape of PCC shows the plate-shaped calcite at 1.0∼3.0 wt% of Ca(OH)$_2$ slurry; the hexagonal plate-shape calcite of the thickness of $0.1{\mu}m$ and the width of $1.0{\mu}m$, at 4.0 wt%.

Synthesis of Amorphous Calcium Carbonation in Ethanol and its Crystallization in the Aqeous Solution

Ahn, Ji-Whan,Park, Jin-Koo,Lee, Sang-Bop,Cho, Hee-Chan,Han, Choon,Kim, Hwan 한국암반공학회 2003 Geosystem engineering Vol.6 No.4

Amorphous calcium carbonate (ACC) was synthesized by reaction to the Ca(OH)$_2$- $C_2$ $H_{5}$ OH-C$H_2O$HC$H_2O$H-$CO_2$ systems. The ACC was then crystallized in aqueous solutions while observing the changes in crystal phases. Using 1L/min of $CO_2$ flow rate, 600rpm of stirring rate and various concentrations of Ca(OH)$_2$ as the conditions, the reaction was divided into three stages according to changes of electrical conductivity that depends on $Ca^{2+}$ concentration. ACC synthesized by these reactions was stabilized to calcite through vaterite according to time. When crystallizing the ACC in an aqueous solution, it was transferred to calcite by means of a low stirring speed regardless of temperature. However, a small amount of aragonite was obtained with higher stirring fate at high temperatures. Furthermore, the addition of N $H_{4}$$^{+}$ ions resulted in an irregular shape and size of the produced calcite, while $Mg^{2+}$ ions enhanced aragonite production.ion.

Influence of Final Crystal with Synthesis of Basic Calcium Carbonate by Carbonation Process

Ahn, Ji Whan,Joo, Sung Min,Kim, Hyung Seok,Kim, Dae Hun,Kim, Jong Pyo,Kim, Hwan Trans Tech Publications, Ltd. 2003 Materials science forum Vol.439 No.-

Korean CCUS System for Circulating Fluididized Bed Combustion (CFBC) Coal Power Plant Ash Utilizing Low Concentration CO2

Ji Whan Ahn(안지환) 한국에너지학회 2017 한국에너지공학회 학술발표회 Vol.2017 No.4