• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1999.10a
• /
• pp.61-64
• /
• 1999

산성침출수에 의한 광산폐기물 매립지 근처의 지하 환경의 오염 및 대처 방안의 효과를 수치적으로 예측하였다. 이를 위하여 지하토양에서 Darcy 법칙을 사용한 침출수의 흐름과 이산-분산에 의한 오염물질의 이동현상을 예측하기 위하여 Galerkin 유한요소법을 활용하였다. 토양오염의 지연을 위하여 석회석 차수막을 연직형과 수평형을 도입하여 그 효과를 조사하였다. 수평차수막에서의 수착이 오염물질의 이동을 지연시키는데 상당한 효과가 있는 것으로 나타났다. 반면에 연직차수막은 지하수의 우회유동으로 인한 오염물질의 확산이 가중되고 있는 것으로 예측되었다. 전반적으로 침출수의 흐름은 광산매립지 제방 근처에서 강하게 일어나는 것으로 나타났다. 이를 근거로 차수막의 효과적인 설치방안이 고안되어야 할 것으로 보인다.

• Resources Recycling
• /
• v.29 no.5
• /
• pp.64-72
• /
• 2020

When the multi-stage combustion process is applied to the cement kiln to reduce nitrogen oxide emissions in the cement industry, oxidation/reduction section that can increase combustion efficiency by reducing NO_x to NO and completely burning unburned materials is essential In this study, when applied the oxidation/reduction system of the cement kiln preheater and calciner, the optimal oxidation/reduction calcination crisis that can secure the quality stability of the final product, cement clinker, was to be observed macroscopically, and the mass change of raw materials according to the burning conditions, decarbonation rate, and calcination rate were investigated. The results showed that the thermal decomposition of raw materials tends to be promoted in the oxidation condition rather than in the reduction condition, and that the thermal decomposition of limestone, which has a relatively high CaO content, is carried out later than that of cement raw meal, which is thought to be caused by the CO₂ fractionation in the kiln. The thermal decomposition properties of raw materials according to oxidation/reducing burning condition showed a relatively large difference in temperature range lower than normal limestone themal decomposition temperature, which is thought to be expected to improve the thermal efficiency of raw materials according to the formation of oxidation condition in the section 750℃ of burning temperature. However, for this study, lab scale. Because there is a difference from the field process as a scale study, it is deemed necessary to verify the actual test results of the pilot scale.

• Korean Journal of Environmental Agriculture
• /
• v.4 no.2
• /
• pp.102-107
• /
• 1985

A pot experiment was conducted to find out the effects of water management, slaked lime and wollastonite on growth and Cu uptake of rice at Cu added soil. The soil was adjusted to 0, 50, 100 and 200 ppm concentration of Cu. The application amount of slaked lime was the lime requirement plus 150 ㎏/l0a and wollastonite 200 ㎏/10a, respectively. The copper concentration in soil which reduced yield significantly was 133.1 ppm for submersion and 136.8 ppm for intermittent irrigation. The application of lime and wollastonite reduced Cu content in brown rice as well as increased rice yields compared to that of no lime. The copper content in plant was increased with increasing soil Cu concentration, however, reduced with submersion and application of slaked lime, and increased with increasing the ratio of Cu/Ca+Mg equivalent in soil.

• The Journal of Engineering Research
• /
• v.3 no.1
• /
• pp.223-233
• /
• 1998

The kinetic and mechanism of the hydrothermal reaction between lime and quartz used solid state reaction equations have been investigated. Hydrothermal reaction on the starting materials was carried out in an autoclave that quartz mixed with calcium hydroxide in CaO/$SiO_2$ ratio of 0.8-1.0 for 0.5-8 hour at saturated steam pressure of $180-200^{\circ}C$. The rate of reaction was given from the ratio of uncombined lime and quartz content to the total lime and quartz content. The rate of reaction was obtained the results by the Jander's equation $[1-(1-\alpha)^{1/3}]^N=Kt$. The reaction of lime is controlled mainly by the dissolution such as N=1, and the reaction of quartz is controlled mostly by the diffusion such as $N\risingdotseq2$. The rate of hydrothermal reaction in the calcium silicate hydrates system is suggested to be determined generally by the mass transfer through the product laver formed around the reactant particles. The rate equation for whole hydrothermal reaction is shown that it is converted into the rate determining step by the diffusion from the boundary reaction such as approximately $N=1-2$.

• Korean Journal of Soil Science and Fertilizer
• /
• v.15 no.3
• /
• pp.166-171
• /
• 1982

A laboratiory experiment incubated at about $30^{\circ}C$ for 34 days was conducted in order to learn the effect of liming materials and rice straw on the volatilization of ammonia from flooded soils applied with urea. 1. The application of calcium hydroxide and calcium silicate increased buffer action of flood soil, though it resulted in increase in the volatilization of ammonia through raising flooded soil pH containing bicarbonate. 2. The mixing of rice straw powder to soil lowered pH of flooded soil, and decreased the volatilization of ammonia. The effect was particulary large when noliming material was used. 3. Calcium hydroxide depressed the evolution of $CO_2$ in the early days of incubation after flooding, while calcium silicate promoted the ammonification of soil nitrogen from the begining of flooding giving slow change in soil chemical properties. The rice straw was also effective in providing a favorable soil condition for the ammonification rather quickly.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 1997.06a
• /
• pp.209.1-210
• /
• 1997

• Clinics in Shoulder and Elbow
• /
• v.14 no.2
• /
• pp.242-247
• /
• 2011

Purpose: We present an atypical case of calcific tendinitis of the shoulder with intraosseous loculation. Materials and Methods: A 59 year-old female complained of acute exacerbation of chronic left shoulder pain and restricted range of motion. Simple radiographs showed a subacromial calcific deposit and magnetic resonance imaging revealed cortical erosion with intraosseous extension of calcific material mimicking infection or tumor. She was managed with arthroscopic excision of the calcific deposit, curettage of the intraosseous lesion and subsequent rotator cuff repair with a suture anchor. Results: Her acute pain promptly subsided. Her rehabilitation was uneventful and she gained full range of motion. Radiographs five months after the operation showed no recurrence of calcific material. Conclusion: Calcific tendinitis of the shoulder can present with a variety of images involving the adjacent bone. The correct recognition of this disorder may avoid unnecessary investigation and treatment.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1063-1070
• /
• 2011

In this study, total of 5 different chemical amendments were evaluated for determining kinetic parameters and stabilization efficiency of heavy metals in aqueous phase. Standard solution of Cd and Pb ($100mg\;L^{-1}$) was mixed with various ratio of amendments (1, 3, 5, 10%) and heavy metal stabilization efficiency was monitored for 24hrs. All examined amendments showed over 90% of removal efficiency for both Cd and Pb except zerovalent iron (ZVI) for Cd (43-63%). Based on result of heavy metal stabilization efficiency, it was ordered as $CaCO_3$ > Dolomite > Zeolite > Steel slag > ZVI for both Cd and Pb in aqueous phase. For kinetic study, first order kinetic model was adapted to calculate kinetic parameters. In terms of reaction rate constants (k), zeolite showed the fastest reaction rate (k value from 0.4882 for 1% to 2.0105 for 10%) for Cd and ZVI (k value from 0.2304 for 1% to 0.5575 for 10%) for Pb. Considering reaction rate constant and half life for heavy metal stabilization, it was ordered as Zeolite > $CaCO_3$ > Dolomite > Steel slag > ZVI for Cd and $CaCO_3$ > Dolomite > Steel slag > Zeolite > ZVI for Pb. Overall result in this study can be interpreted that lime containing materials are more beneficial to remove heavy metals with high efficiency and less time consuming than absorbent materials.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.1
• /
• pp.109-115
• /
• 2006

The calcifying odontogenic cyst (COC) predominantly affected Maxillary anterior segment and it is developmental cyst. But COC showed diverse terminology or classification, clinicopathologic features as well as its biologic behavior COC usually presents as slowly enlarging but otherwise symptomless swelling. Association with impacted teeth and odontoma is described in $24{\sim}30%$. The epithelial lining of COC(ghost cell) appears to have ability to induce the formation of dental tissues in the asjcents connective tissue wall. This case is a COC associated with a odontoma involving an impacted left maxillary canine in 14-year-old female child. Radiographic examination revealed a well-demarcated radiolucent lesion partially occupied by a radiopaque mass, involving the left canine. The histologic sections showed cystic cavity lined with ameloblastic epithelium containing ghost cell masses with regular and irregular shape odontoma. The final pathologic diagnosis was calcifying odontogenic cyst with odontoma(Type IB by Preatorius). Enucleation and elimination of the included tooth were performed. Now endodontic treatment was preformed on the 1st premolar of the upper left jaw, which had a lesion. And the patient and their parents want to have the orthodontic treatment performed and would like to keep the space maintainer.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.4
• /
• pp.645-650
• /
• 2004

Calcifying odontogenic cyst(COC) is a rare developmental odontogenic cyst, which shows diverse classification and terminology. Cystic epithelial lining of COC is composed of basal cell layer of columnar cells and overlying layer of stellate reticulum. In the epithelium, ghost cells that might induce adjacent mesenchymal tissue to develop dental organ are shown characteristically. In spite of low rate of recurrence, we have to get a histopathological examination so that odontogenic lesions may recur without fully curettage of lining epithelium. 7-year-old male child came pediatric dentistry in wonkwang university dental hospital in order to check the delayed eruption of left maxillary central incisor. Radiographic examination revealed a well-defined radiopaque mass, overlapping impacted left central and lateral incisor crown. Enucleated mass was tooth-like features and also had epithelium lining. Results of histopathologic procedure, we saw the lots of ghost cell and proliferating hard dental tissues. Also we saw the cystic epithelium cells. It revealed diagnosis of the COC associated complex odontoma. For this reason one should consider of COC when patients present odontoma-like lesion with impacted tooth.