분사법에 의한 탄산칼슘 제조

신보철,한상오,김주호,송지훈,송근호,이광래 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

본 연구는 탄산가스화법에 의한 탄산칼슘 입자 제조 공정에 있어서, 탄산가스로 채워진 반응기에 수산화칼슘 슬러리를 분사하는 방법으로 탄산칼슘 입자를 제조하였다. 수산화 칼슘의 농도(0.25~1.0wt%), 분사압력(0.5kgf /㎠~1.5kgf /㎠) 및 반응기 온도(20℃, 28℃)의 변화에 따른 생성된 탄산칼슘을 관찰하였다. 수산화 칼슘의 농도가 비교적 높으면(0.75wt%, 1.0wt%), 생성물의 pH와 전도도는 높게 나타났다. 분사압력에 의한 탄산칼슘 제조의 변화는 분사압력이 높아질수록(1.5kgf /㎠), pH와 전도도는 높게 측정되었다. 그러나, 수산화 칼슘의 농도와 분사압력의 변화가 탄산칼슘의 입자크기, 형태, 결정구조에 영향을 미치지는 않았다. 반응기의 온도가 28℃에서 생성된 탄산칼슘은 1.0㎛이하의 칼사이트 상 입자가 제조되었으며, 20℃에서 생성된 탄산칼슘은 0.5㎛이하의 칼사이트 상 입자가 제조되었다. 반응기의 온도가 낮아질수록 탄산칼슘 입자의 크기가 작아짐을 알 수 있었다. For the preparation of calcium carbonate particles from aqueous Ca(OH)2 slurry, carbonation reaction of aqueous Ca(OH)2 slurry was carried out by spouting the aqueous slurry of Ca(OH)2 into reactor filled with CO2 gas. The concentration of Ca(OH)2 varies from 0.25wt% to 1.0wt%, nozzle pressure from 0.5kgf /㎠ to 1.5kgf /㎠, and reactor temperature were set at 20℃ and 28℃. With relatively high concentration of 0.75wt% and 1.0wt% of Ca(OH)2, pH and conductivity of product-stream were observed high value. High pH and conductivity were observed at high nozzle pressure of 1.5kgf /㎠. The concentration of Ca(OH)2 and nozzle pressure, however, did not change the particle size and shape of calcium carbonate synthesized by carbonation reaction. The reaction temperature affected particle size. At reactor temperatures of 28℃ and 20℃, the particle sizes were about 1.0㎛ and 0.5㎛, respectively. Crystal structure of calcium calcium carbonate was of calcite. When reactor temperature was lower, the size of calcium carbonate particle was smaller.

The Computer Algebra Systems in Mathematics Education : A Review of Recent Research

Kwon, Oh-Nam,Shin, Eun-Ju,Shon, Bo-Kyung 이화여자대학교 교과교육연구소 2001 East west education Vol.18 No.-

This study examines the potential role for Computer Algebra Systems(CAS) in such an educational context, particularly their potential to get students more engaged in the learning of mathematics as well as to reduce the "strangle hold" of prerequisite algebraic skills, in courses such as functions, introductory calculus. What is the present status of and near-future outlook for computer algebra in Korean secondary schools? The answer that arises from this review of available fact is: bright with promise, but still dim. Several recent developments have set the stage for an acceleration in the dissemination rate for CAS to high schools. However, this review of some past and present conditions indicates that many years will pass before computer algebra is impacting high school mathematics as much as hand-held calculators are doing now.

방사선 수술시 경험적 표적 근사화에 근거한 최적화 방법 개선

오승종,최경식,송주영,서태석,Oh Seungjong,Choi Kyoung-Sik,Song Ju-Young,Suh Tae-Suk 한국의학물리학회 2005 의학물리 Vol.16 No.4

정위적 방사선수술(stereotactic radiosurgery, SRS)은 한번에 고선량의 방사선을 병변에 조사하는 방사선 치료법으로 단 한번의 조사로 고선량의 방사선이 환자에게 주어지므로 정확한 수술계획의 수립이 필요하다. 현재, 수술계획은 수술계획자에 의해 직접 시행착오를 거듭하며 수립되고 있으며 이로 인해 계획의 재연성과 신뢰성에 문제가 제기되고 있다. 본 연구에서는 경험적 표적 근사화에 근거한 오등의 연구방법을 바탕으로 각 단계를 개선하여 더 나은 수술계획 결과를 얻을 수 있도록 하였다. 주어지는 병소의 다양한 모양을 동일한 높이의 원통을 사용해 근사화하고, 각각의 원통의 중심점의 위치와 지름에 의해 주변의 원통과 하나로 결합시켰다. 그 후 각각의 원통 내에 등선량중심점(Isocenter)을 모사한 구를 미리 정의된 규칙에 의해 채워 나갔다. 두 개의 가상 표적을 이용해 기존 알고리듬과 본 연구에서 개선한 알고리듬을 이용해 최적화를 수행하였다. 그 결과 두 개의 가상 표적에서 PITV (proscription isodose to tumour volume ratio)와 MDPD (maximum dose to prescription dose ratio)의 별다른 차이가 보이지 않았으며, 사용된 구의 수를 각각 $36\%$, $26\%$ 줄일 수 있었다. 원통과 구형을 이용한 이러한 기법은 정위적 방사선 수술시 수술 계획자에게 도움을 줄 수 있을 것으로 생각된다. Stereotactic radiosurgery (SRS) is a technique to deliver a high dose to a target region and a low dose to a critical organ through only one or a few irradiation. The SRS must be planned exactly. Currently the surgery plan is peformed by trial and error method. There are many questions about the reliability and reproducibility of the plan result. This study Improve each step of the Oh's method based on heuristic target shaping to obtain the better result. The target was reconstructed using cylinders with same height and the neighbored cylinders were combined according to the difference of each center and diameter. Then, spheres were packed within each cylinders by the packing rules. Two virtual targets were used to compare this method with Oh's method. As a result, the numbers of isocenter were successfully reduced - more than $35\%$ and $26\%$ - without serious differences of proscription isodose to tumour volume ratio (PITV) and maximum dose to proscription dose ratio (MDPD). This technique using cylinder piling and sphere packing will be a helpful tool to planner in stereotactic radiosurgery.

석탄회를 이용한 석탄광산 폐기물의 안정화 효율성 평가

오세진(Se-Jin Oh),김성철(Sung-Chul Kim),고주인(Ju-In Ko),이진수(Jin-Soo Lee),양재의(Jae E. Yang) 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.6

본 연구는 다량의 중금속을 함유하는 폐석탄 광산에 적치된 폐석으로부터 발생하는 침출수의 안정화를 위해 석탄회를 안정화제로서의 적용성을 평가하는데 목적이 있다. 석탄폐석에 석탄회를 적용하여 컬럼시험을 수행한 결과는 다음과 같다. 1) 석탄회의 pH는 비산재와 바닥재가 각각 11.1, 9.7의 강알칼리성을 갖는 것으로 나타나 강산성 조건의 폐석 (pH 3.5)를 교정하였으며 유기물을 비롯하여 식물생장에 필요한 영양소인 인산, 칼슘 등을 함유하는 것으로 나타나 폐석과 혼합할 경우 비옥도가 개선될 수 있을 것으로 판단된다. 2) 폐석만을 충진한 컬럼에서 발생하는 침출수의 pH는 3.5~4.0의 수준을 시험기간 동안 지속적으로 유지하는 것으로 나타나지만, 석탄회의 처리량에 따라 40% (pH 5.0~6.0) 〉 20% (pH 4.5)로 나타나고, 동일 처리량 (40%)의 처리방법에 따른 효율성은 완전혼합 (pH& & 5.0~6.0) 방법이 층위처리 (pH 4.0~4.5)에 비해 pH 상승효과가 높은 것으로 조사되었다. 3) 침출수의 Ca과 Mg의 함량은 4 pore volume까지 빠르게 용탈되다 그 이후부터 안정화 되었으며 석탄회에서 용탈된 Ca과 Mg의 영향으로 폐석에 함유되었던 Cu, Pb, As, 및 Al 등이 탄산이온 (CO₃<SUP>2-</SUP>) 또는 수산화이온 (OH-)과 불용성 화합물을 형성하여 안정화 되는 것으로 사료된다. 4) 철의 용존함유량에 대한 분석결과 석탄회 처리구의 용존량이 석탄회를 40% 층위처리한 처리구를 제외하고 대조구에 비해 약 8-74% 정도 감소하는 것으로 조사 되었다. 5) 석탄회를 이용한 폐석의 중화 및 철의 용존량 감소 효율성을 평가한 결과 폐석의 중화 효율성은 석탄회를 40% 완전혼합한 경우 가장 높았으며 철의 용존량 감소 효율성은 석탄회를 20% 완전혼합한 경우가 가장 좋은 것으로 조사되었다. 따라서 석탄회를 이용하여 현장에서 폐석을 처리할 경우 약 20-40%의 석탄회를 처리해야 높은 효율성을 얻을 수 있을것으로 사료된다. In this study, coal combustion ash (CCA) was evaluated for its stabilization effect on acidic mine waste with column experiment. Total of six treatments were installed depending on mixing ratio between coal wastes and CCA (0, 20, 40%) and mixing method (completely mixing and layered). Artificial acidic rain (pH 5.6) was used for feeding solution with flow rate of 0.05 mL min<SUP>-1</SUP>. Result showed that higher pH of leachate was observed as more CCA was mixed. The highest pH in leachate was measured when 40% of CCA was mixed with coal waste (pH of 5.8). Also, complete mixing with CCA and coal waste was more effective to increase the pH of leachate than layered treatment. Regarding the reduction of soluble Fe amount, the highest efficiency (78%) was observed when 20% of coal ash was completely mixed with mine waste. Based on those result, optimum mixing ratio of coal ash with mine waste can be ranged 20-40% depending on environmental circumstances in the field.

회분식 반응기에서의 공정변수 변화에 의한 침강성 탄산칼슘 제조

신보철,한상오,김주호,송지훈,송근호,이광래 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

For the preparation of calcium carbonate particles from aqueous Ca(OH)2 slurry, carbonation reaction of aqueous Ca(OH)2 slurry was carried out by batch method the CO2 into reactor filled with aqueous slurry of Ca(OH)2. The concentration of Ca(OH)2 varies from 1.00 to 7.00wt%, reactor temperature at 20 and 40℃, and reactor pressure from atmospheric pressure to 6.0kgf/cm2. Crystal structure of calcium carbonate was of calcite, the particle size were about 0.05 ∼2.0㎛, and the particle shape was cubic and spindle. When reactor temperature was higher, particle size of calcium carbonate was bigger and particle share was varied, but reaction rate was increased. When reactor pressure was higher, particle size of calcium carbonate was smaller, particle shape was cubic, and reaction ramie was increased.

Streptobacillus sp.가 생산하는 pullulanase에 관한 연구

오두환,지희숙,최형택,신원철,유주현 연세대학교 산업기술연구소 1986 논문집 Vol.18 No.2

A bacterium with the highest pullulanase activity was isolated from the soil and identified as Streptobacillus sp. Y-716. The optimum culture condition of Streptobacillus sp. for the production of pullulanase was as follows; 1.2%(w/v)soluble starch, 0.7%(w/v) CH₃COONH₄, 0.05%(w/v) MgSO₄7 H₂O, 0.01%(w/v)FeSO₄7H₂O, at 30℃, for 48 hrs. The pullulanase from the culture broth of Streptobacillus sp. Y-716 was purified about 46 fold by ammonium sulfate precipitation, dialysis. DEAE-cellulose and Sephadex G-200 column chromatography. The purified enzyme was stable between pH 5.0 and pH 7.5. It was inactivated rapidly above 35℃. The Km value and Vmax of the purified enzyme were 0.0137mg/m/ and 0.666μm/min. on pullulan, respectively.

요먼리 沒落의 再評價

吳主煥 慶北大學校 1992 論文集 Vol.52 No.-

근세초 英國農村社會의 中核으로서 영국인들이 자부하던 獨立自營農民層 요먼리(yeo-manry)의 成立과 性格에 대해서는 이미 다른 곳에서 취급된 바 있으나 그 沒落問題는 時間的인 거리때문에 취급되지 못하였다. 따라서 요먼리의 沒落問題는 그 成立과 같은 水準에서 취급될 필요가 있다 할 것이다. 뿐만아니라 다른나라들에서는 19세기말 이래 오늘날에 이르기까지 한 社會階層으로서의 存在意義를 상실하게된 요먼리의 沒落문제가 크게 論難의 대상이 되어왔으나 우리나라에선 그에 대한 연구가 전연 업는 실정이다. 그리고 英國 요먼리가 겪었던 歷史的 운명이 現下 우리나라 農民層이 겪고 있는 운명과 흡사하다는 생각을 가지고 있다. 이러한 關心에서 본고에서는 요먼리 沒落에 관한 제문제를 다각적으로 再檢討하므로써 우리나라 農民層에게 닥쳐올 운명을 전망해 보고자 한다. 요먼리 沒落문제는 學者들간에 見解를 달리하여 왔으나 그중에서도 요먼리沒落→산업노동자 創出의 原因을 둘러싼 論難이 그 中心 課題로서 마르크스주의 史家들의 見解와 부르조아 史家들의 見解가 오랫동안 대립되어 왔다. 前者는 議會인클로저(parliamentary enclosure)라는 英國政策의 강제적 수단에 의하여 요먼리는 沒落하여 勞動者로 전락하였다고 주장하는데 대하여 候者는 요먼리는 議會인클로저가 실시되기 이전에 다른 要因들에 의하여 몰락하였으며 산업노동자의 創出은 잉여人口에 의한 자연발생적인 현상이었다고 주장하고 있다. 본고에서는 먼저 요먼리沒落論의 대두와 그 內容을 개관한 다음 그 沒落의 정도와 시기, 요먼리의 性格과 法的 保障度, 沒落의 原因등을 차례로 살펴보고, 끝으로 1960년대 이래 요먼리 沒落문제를 꾸준히 추구해온 체임버스(J. D. Chambers)와 민게이(G. E. Mingay), 그리고 마르크스주의 史家인 라조니크(W. Lazonick)등의 최근의 연구를 중심으로 요먼리沒落 論爭史를 再檢討하여 요먼리와 의회인클로저와의 관계를 밝혀보고자 한다. The time-honoured debate on the decline of yeomanry has been afresh raised by bourgeois historians such as J.D.Chambers, G.E.Mingay and D.S.Landes on the one hand and by Marxist historians such as E.P. Thompson and W.Lazonick and local historian W.G.Hoskins on the other. This article aims to clarify the unexhausted problems of the decline of yeomanry by reexamining of many-sided angles of the decline of yeomanry, that is, its declining period, extent and causes as well as legal protection of copyholders and impact of parliamentary enclosure and population growht on the decline of yeomanry in terms of having an insinght into fortunes of peasants in Korea, who are facing with the storm of Urguay Round. The reappraisal will be summarized as follows; The view on the first half of the 18th century among views on the declinning period seems to gain great support from scholars who have made statistical case studies. This writer, however, feels that this view has to be supplemented by further local studies throughout the country. The extent of its decline amounted to abort 50% during the period from the end of the 17th century to 1750s, when the typical yeomanry has lost its significace of a distinct social class as a historical category. And the causes of the decline were various in short and long-term factors; uncertainty of legal protection of copyholders, heavy war taxes, fall of corn prices, enclosures by agreement and by parlinament which Marxists stressed, partible inheritance system and growth of population in the 18th century which bourgeois historians emphasized. Lastly, just as the fortunes of yeomanry had badly depended on the interference of state power, parliamentary enclosure, so the fate of peasants in Korea will depend on the interference of national power, the Urguay Round. Already considerably declining peasant in Korea are liably to trace the same fate as yeomanry in the 18th century England, if they won't be sided by the protection of national policy.

관행농법과 유기농법의 비교연구

오주성,박흥식,정순재,정원복,진동호 東亞大學校 大學院 2000 大學院論文集 Vol.25 No.-

This study focuses on Comparative of conventional Agriculture and Organic Farming Among various kinds of environmentally sound farming practices the organic and Conventional Agriculture practices are chosen for this study. The main objective of this study is to evaluate the technological systems of organic farming practice in order to find the possibility of extending such technological system to the general farmers. Compared with the general farming practices, the organic farming requires many special technologies. Among them, technologies relating to compost making, pest, insect and weed control are different from those fo general farming practices. New technologies for the improvement of organic farming practices are developed or and imported from abroad by the organic farming association. As far as technology development for the organic farming, many research organizations between the goals of technology development of the conventional and organic farming system. In other words, land productivity of the organic farming technological system is lower than that of the conventional farming technological system.

『Yeomanry 消滅考』

吳主煥 慶北大學校 1971 論文集 Vol.15 No.-

This thesis is an attempt to approach the true nature of modern (capitalistic) society by examining the disappearance of yeomanry. A little work has been done by this writer on the subject of "A Consideration on the Yeomanry-Especially in the Process of Its Growth and Defining Its Concept," and now it remains as an unaccomplished task for him to consider the process of the stratification of yeomanry and its disappearance. Why and when did yeomanry disappear? Two things must be considered before we can answer these questions; the historical characteristics of yeomanry and a survey of the theories of the disappearance of yeomanry by scholars. As the parcelling peasantry (parzellen Bauern) typical yeomanry has dual, transitional and self-destructive characteristics and plays its historical role in the transitional period between the dissolution of feudal land-ownership and the establishment of a modern capitalistic system (from 16th century to 19th century). On the disappearance of yeomanry, different views have been expressed by scholars who differed from one another in their definition of its conception, in the historical sources of evidence analized, and in their opinion of causes. Their opinions of the true period of the disappearance of yeomanry range from ① the first half of the 18th century, ② to the latter half of the 18th century and ③ to the first half of the 19th century after 1815. The first view appears to have wider support of scholars who have made partial, sectional studies about yeomanry by statistical analysis. The following may be stated as a summary of this thesis; With Tudor Enclosure and a great shift in the land-ownership caused by the dissolution of Monasteries and the English Revolution, yeomanry which was already in the beginning process of stratification in the 16th century was further accelerated into dissolution and began to disappear from the society. The stratification of yeomanry, along with Paliamentary Enclosure and the Industrial Revolution, was completed by the time the capitalistic system (tripartite division) was firmly established. However, the exact period of the disappearance of yeomanry can be stated only after precise definition of its conception and further partial, sectional studies expanded on a national scale are made by statistical analyses.

Tawney敎授의 近代社會觀

吳主煥 경북대학교 1968 論文集 Vol.12 No.-

This thesis is intended as a brief evaluation of Professor Tawney's view on the modern (capitalistic) society. Richard Henry Tawney, as a great historian, thinker and humanist, made epoch-making achievements through his scholastic works. His study of the 16th century made such a great impact that the century is often called Tawney's century". His works were motivated by his serious consciousness of the need to reform conflicts and vice in the modern society through analyzing its essence in the light of history. He attempted to investgate the modern society in terms of relation between economy and religion. His theory was based on the conviction that economic categories of the modern society along with religion have been the most potent force in giving its character. The gist of his theory on modern society can be summarized as follows; ① The modern society after the Glorious Revolution became absolutely irreligious without internal union with religion. ② Religion, which ceased to be the master interest of mankind as a result of triumph of religious indifferentism and economic virtues, has dwindled into a part of an individual life. ③ On the other hand, material riches has become the supreme object of human endevour, and economic expediency is regarded as the final criterion to estimate human interests and activities. ④ The modern society in which economic activities claim the supreme object of all human being interests and activities, resulted in estrangement of humanity and value inversion. Professor Tawney criticized severely that the irreligious and inhuman modern society is one of fetish worship and idol worship of material riches. He laid stress on the role of religion in reforming vicious elements and in reralizing social justice in the modern society.