Cement 粉碎에 있어서 Ethylamine類 粉碎助劑가 미치는 影響

金昺圭,梁斗錫,金石柱 成均館大學校 1981 論文集 Vol.30 No.-

所要 粉碎動力費를 節減하기 위하여 有機溶媒를 粉碎助劑로 擇하고 液相接觸으로 그 粉碎效果를 向上시키는 硏究는 여러 학자들에 의해 進行되어 왔다. 筆者는 이에 立脚하여 우리나라에서 動力費節減이 要求되는 Cement 製造를 대상으로 하여 Ethylamine 類를 粉碎助劑로 택하고 더욱 接觸確率을 증가시키기 위하여 氣相으로 接觸시켜 Cement 粉碎效果를 硏究하였다. 또한 그 原因으로 추정되는 吸着現象을 아울러 測定하여 粉碎效果와의 관계를 檢討하였더니 粉碎가 시작된 후 0∼6 時間內에서는 각종 첨가물이 거의 없는 상태, 즉 Clinker 單一系의 粉碎現象과 비슷한 粉碎傾向을 보여 주었고, 6∼8時間 사이에서 급격한 吸着能의 증가현상을 보여주었다. 이 때부터 粉碎率이 첨가물질에 의한 特有의 증가현상을 보여주고 이Td서 吸着能이 粉碎率과 깊은 관계가 있음을 알았고, 吸着能이 큰 물질일수록 粉碎效果가 더욱 좋은 結果를 보여주어서 粉碎效果는 吸着能과 吸着量에 比例됨을 認知하였다. 더욱 構造物材料로서의 本質인 物性을 測定하여 이에 따르는 使用許容範圍를 提示하였으며 結果的으로 1. 이들 粉碎助劑의 添加量이 증가하면 粉碎效果도 증가한다. 2. 粉碎效果는 Ethylamine 類가 Ethanol보다 떨어졌고, 沸點이 높은 tri-Ethylamine이 di-Ethylamine 보다 좋았으며, Ethanol>tri-Ethylamine>di-Ethylamine順으로 됨을 알았다. 3. Ethyamine 類의 Cement 粒子에 對한 吸着現象은 Ereundilich 吸着等溫式과 恰似했으며, 어느 범위내에서는 粉碎助劑의 吸着量이 증가함에 따라 粉碎效果가 좋아진다. 4. 粉碎效果가 좋을수록 Cement의 物性을 다소 감소시키고 있으나 構造物의 原資材로 사용하는 경우 그 使用分野에 따라 큰 지장이 없이 사용할 수 있는 것으로 看做된다. Most expenses of production in cement industry are electric power, therefore, many scientists had researched through various ways for saving power cost. Especially, they are an urgent problem, for Korea electric power costs so expensively. As one of the means of saving power, by crushing aid of organics (i.e. primary, secondary alcohol series, fat, or resins), it was attempted to prevent the growth of secondary particles on liquid contacting system. But it was not sufficient on heterogeneous dispersion system. In this experiment, the increasing of crushing effect was investigated in gaseous contacting system and 100℃ of not influencing upon cement products. Then, organic crushing aid were used di-Ethylamine (bp 55.4℃) and tri-Ethylamine (bp 89.7℃) in range of 0.1-0.5wt. % concentration. Thus, saving power and properties of structures depend on factory data. On the standard of compared data, a continuous method in dry crushing was adopted to a practical operation condition. Therefore, it must be analysed by batch method in a possible application because it is better than continuous method. The computation on power should be done by crushing ratio, directly, and it become clear tendency of specific surface mean diameter of particles to be decreased according to hour limit. Also, the increment of crushing effect had been referred to the adsorption phenomena on cement particles by the vapor of organic substance with crushing aid in the experiment of crushing. Then, the adsorption phenomena has researched by Gas-chromatograpy method, because of it's convenience and accuracy. Organic substance had been used as the adsorbate (i.e. di-Ethylamine and tri-Ethylamine). Through the experimental investigation, the following results were obtained: 1. Power saving of the cement crushing system added organic substance is 2.6% better than that of a simple system of clinker crushing. 2. In crushing, the order of effectiveness are Ethanol tri-Ethylamine and di-Ethylamine. i) Ethanol is 20.8%(in range of 0.4-0.5wt%) ii) di-Ethylamine is 13.7% (in range of 0.4-0.5wt%) iii) tri-Ethylamine is 15.4% (in range of 0.4-0.5wt%) 3. The compressible strength of the cement organic substance the order of decrease are Ethanol, tri-Ethylamine, di-Ethylamine. ⅰ) Ethanol is 5-6% (decrease) ⅱ) di-Ethylamine is 4.1% (decrease) iii) tri-Ethylamine is 4.3% (decrease) 4. Absorbed amount of the organic solvents is an important factor of cement crushing system; the grinding rates are increased when the amount of grinding aid are increased. 5. The adsorptivity increased in the order of Ethanol, tri-Ethylamine, di-Ethylamine, di-Ethylamine. 6. Adsorption phenomena of Ethylamines on cement have been adsorbed to show a tendency similar to the Freundlich's adsorption isotherm equation. 7. After 6 hours of the crushing time when the increase in the crushing efflciency has taken place, the amount of adsorption has rapidly increased, while the amount of adsorption has shown almost negligible increase. 8. Crushing efflciency has been increased with the increasing amount of Ethylamines absorbed on cement i.e, the higher the absorptivity is, the better the crushing efflciency is.

회전전기기기의 회전동작과 페이서도와의 관계

황석영,김영천,이해경 단국대학교 1996 論文集 Vol.30 No.-

Energy conversion in rotating electric machines results from the relative movement of windings, magnetic flux and m.m.f which are elementary factors. In this paper, a technique repesenting the above 3 factors as space vectors in re-lative movement is proposed. The space vectors are related to phasors of A.C rotating machines under steady state. As a result of application of the technique, actual relative movements of machines corresponding to any phasor diagram are well visualized and especially concepts of torque producing mechanism is easily described.

백서 골수세포의 석회화 과장에 미치는 치은 섬유아세포의 영향

김석용,권영혁,박준봉 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.1

The purpose of this study was performed to investigate the mineralization and differentiation of osteobalsts for bone regeneration in vitro and the effect of rate of the composition in periodontal cells on mineralization. For this study, healthy gingival tissues were surgically obtained from the patients during 1st premolar extraction for the purposes of orthodontic treament. Gingival tissue was washed several time with Phosphate buffered saline contained high concentration of antibiotics and antifungal agent, and cultured in Dulbecco's Modified Eagle's Medium(DMEM, Gibco, U.S.A.) Every cell were cultured in state at 37 C, 100% of humidity, 5% of CO2 incubator. Bone marrow stromal cells were isolated from 5-day-old rat femur with using medium irrigation mathod by syringe. Cell suspension medium were centrifuged at 1500 rpm for 5 min and then cultured in the petri dish. Two kinds of cell were freezed and stocked in the liquid nitrogen tank until experiment. Cell were incubated into the 24multi-well plate with 5 x 104 cell/well of medium at 37 ° C, 100% of humidity 5% CO2 incubator for 24 hours. After discarded of the supernatent of medium, 0.5m of medium were reapplied and incubated. And counted the number of cell using the hemocytometer and inverted light microscope. We have measured the number of mineralized nodule with using Alizarin red S. staining in microscope; Furthermore every cell were observed the morphological change between every rate of co-culture of the two kinds of cell. The results were as follows; The rate of proliferation of co-culture cell revealed high rate tendency compared the bone marrow stromal cell only and low growth rate to compared with gingival fibroblast only. The tendency of formation of the mineralized nodule were observed dose-depend pattern of bone marrow stromal cell. It is concluded that the gingival fibroblast may inhibit the formation of mineralized nodule in the culture of the bone marrow stromal cell.

共通 直列 임피던스의 竝列化技法

黃錫永 단국대학교 1984 論文集 Vol.18 No.-

For the computation of branch current in a network drived by a common single voltage source with its internal impedance, node/loop analysis method or Thevenin/Norton theorem have been used. However the application of the above methods are tedious due to the common series impedance (the internal (impedance) and especially have week point that can not evaluate easily the influence of the common series impedance on each parallel branch impedance. In this paper, a method to transfer a parallel impedance equivalent to the common series impedance to each parallel branch impedance and to connect all the branch circuit in parallel with the common voltage source is proposed introducing a convenient index for the influence of the common series impedance in order that the computation of each branch current can be carried out independently and directly.

16세기 프랑스 서술문학의 장르 체계 연구

유석호 연세대학교 대학원 1987 延世論叢 Vol.23 No.1

Cet article a pour but d'analyser les traits constitutifs du genre narratif au 16e sie`cle, notamment ceux des trois genres fondamentaux: nouvelle, conte et roman. Pour cela, nous nous proposons d'e´tudier ces genres dans leur contexte historique en tenant compte e´galement du syste`me avec lequel ils sont en corre´lation. La nouvelle, introduite nouvellement en France a` la fin du 15e sie`cle sous l'influence du De´came´ron de Boccace, re´ve`le une fe´condite´ extraordinaire dans le domaine de la litte´rature narrative. Au cours de la premie`re moitie´ du 16e sie`cle, la nouvelle, conside´re´e au de´but comme une simple histoire plaisante caracte´rise´e par l'authenticite´, la nouveaute´ et la nature anecdotique de la matie`re et aussi par la brive`vete´ du re´cit, finit par s'appliquer a` des sujets plus divers de nature re´aliste. A cert e´gard, l'Heptame´ron de Marguerite de Navarre marque un sommet des recueils de nouvelles au 16e sie`clne; ses nouvelles parfois longues contrastent avec les nouvelles-fabliaux pre´ce´dentes et montrent un certain type de nouvelle sentimentale et litte´raire, plus proche de la notion moderne du genre. Par rapport a` la nouvelle, les deux autres genres, influence´s plus directement par la litte´rature orale et me´die´vale, occupent une place assez re´duite dans le syste`me du genre narratif au 16e sie`cle. Le seul exemple du recueil de contes, les Comptes amoureux de Jeanne Flore sont une re´invention litte´raire a` partir des oeuvres e´crites, qui est fondamentalement diffe´rente du conte proprement dite, issu de la tradition folklorique. De me^me, malgre´ la popularite´ conside´rable des romans de chevalerie qui sont une forme vulgarise´e du roman me´die´val, si l'on met a` part les tentatives isole´es d'He´lisenne de Crenne et de Rabelais, un nouveau type de roman n'acquiert pas encore l'autonomie suffisante pour former un nouveau genre. En conclusion, les trois genres narratifs du 16e sie`cle ne parviennent pas encore a` use syste´matisation comparable a` celle de l'e´poque classique ou` la norme des genres e´crits commence a` s'imposer, ce qui montre la limite et aussi la valeur historique de la litte´rature narrative du 16e sie`cle en tant qu'e´tape pre´paratoire de la litte´rature moderne.

충전탑에서 흡수에 따른 물질전달과 수력학적 거동에 관한 연구

김석택 한국환경과학회 2000 한국환경과학회지 Vol.9 No.5

Packing tower has been used in the chemical industry and the protection of environment for a long time. In the view of environmental protection, purification of exhaust gas can be performance effective by gas absorption in counter-current packing tower. In this study, characteristics of hydraulic and mass transfer were investigated in D. 0.3m × H. 1.4m packing tower with 50mm plastic Hiflow-ring. This study was carried out "Test systems were experimented in conditions of Air, Air/H_2O, NH_3-Air/H_2O, NH_3-Air/H_2O- H_2SO_4, and SO_2 -Air/H_2O-NaOH under steady state". The extent of test included dry and wetting pressure drop, physical law, separation efficiency, and hold-up as function of gas and liquid load.

「Sons and Lovers」에 나타난 性을 통한 자아회복 의지

김석주 瑞逸傳門大學 1988 論文集 Vol.7 No.-

Every human activity has in it volition to restore the lost humanity and regain the forlorn ego. An ardent aspiration after returning to our own pristine self lies at the bottom of our literature working. Sons and Lovers, D. H. Lawrence's early masterpiece, is the result of his self resotration will. Through his life, did Lawrence suffered from keen desire of self realization orvercoming the distorted love resulted from his mother during his childhood and young days. The purpose of this paper is to try an approach, based on his works, to his annoying attempt for settling his trouble and groping self recurrence. As shown in Sons and Lovers, he tried to get out of shadow of his mother's influence, which prevented him from establishing normal relationship with female and acquiring the independence of his real self. But such his effort could not avoid some limitation in its attribute. Lawrence's self-consciousness flow is characterized by the conflict between 'spirituality' and 'sensuality' ; the former was influenced by his mother and the latter by this fater. It seems that Lawrence's conflict in the duality of his character is helpless with regard to his view point of dualism betweem his inner and outer experience. Lawrence sought aloness because he felt that his individuality and singleness was threatened with obliteration. But soon he found it was of no realizable attempt owing to his own inclination to depend on a woman. Thus, he asserted that the domiantion of male by female, or domination of female by male should be released, and that the relationship between male and female should be a pure balance of two single beings. This means, of course, to maintain one's identity in balanced relation with the other. I think that Lawrence's greatness does not lie in his annying endeavor for resoration/recurrence of his self but lies in the point at issue presented in his works, which is considered to be a prototype of tantalizing will in our times flooded with distressed voices.

테니스경기 내용에 관한 분석 연구 : 한국 대학 테니스선수를 중심으로 Focus on Korean University Elite Athletes

김석환 韓國體育大學校 1999 論文集 Vol.22 No.-

An investigation of the points earned by various strokes in various domestic tennis competitions, as previously suggested in the methodology section, the following conclusions were made: 1. For the male university athletes, various strokes' contribution to the points earned is high in the order of smashing, drop shot, ground smashing, passing shot, forehand volley, backhand volley, lob, half volley, forehand stroke, backhand stroke, and serve return. In general, the points earned were much higher than the points lost. 2. For the female university athletes, various strokes' contribution to the points earned is high in the order of ground smashing, passing shot, drop shot, lob, backhand volley, forehand volley, smashing, half volley, forehand stroke, backhand stroke, and serve return. In general, the points earned were much higher than the points lost. Considering the above conclusions, playing near the net is safer, and playing near the baseline is less safe. Therefore, coaches must help their athletes reinforce such attack skills as volley, smashing and more, while introducing and developing scientific and systematic training methods to help their athletes' ground stroke and lob become safer and stronger.

南北韓關係 變化實相과 向後 展望 硏究

강석승 안양대학교 복지행정연구소 2002 福祉行政硏究 Vol.18 No.-

지난 2000년 6월에 이루어진 남북정상회담과 이를 통한 '6.15남북공동선언'은 남북의 양 정상이 직접 서명하였다는 점에서 민족통일의 새로운 지평(地坪)을 연 '역사적 문건'이라 할 수 있으며, 이렇기 때문에 이 선언의 채택-발효를 지켜보는 우리 모두의 기대와 희망은 '가히 하늘을 찌를 듯' 높기만 하였고, 그 이후 남북관계는 다른 어떤 시기 보다 질-양적으로 큰 변화를 보여 왔다. 그러나 이후의 남북관계는 과거와 같이 북측의 일방적인 약속 파기나 합의불이행으로 때때로 소강상태를 보이면서 ????을 나타나게 되었고, 그 때마다 우리는 적지 않은 실망과 비관적인 마음을 감출 수 없었다. 이후 임동원대통령특사의 방북(2002.4.3-4.6)으로 인해 '4.5공동보도문'이 발표되고 북측이 '서해교전(2002.6.29)에 유감을 표명하면서 중단된 남북장관급회담 재개제의를 하게 되고, 이를 우리 측이 전향적 차원에서 받아들임에 따라 6.15공동선언의 이행·실천을 위한 남북대화·회담은 정상궤도에 진입하여 제8차 남북장관급회담을 비롯한 각급 회담·대화가 진행되어 현재에 이르고 있는 것이다. 그러나 '제임스 캘리' 미특사의 방북으로 인한 북한의 '핵개발 프로그램'에 대한 문제가 좀처럼 진정될 기미를 보이지 않고, 북한 스스로가 이 문제에 관하여 '신속하고도 분명한 입장과 조치'를 밝히지 않는 한 남북관계의 질적인 개선은 어려울 것으로 보이기 때문에 그 ??은 북측의 '상응하는 조치'에 달려 있으며, 바로 이런 조치를 전제로 하여 '6.15남북공동선언'에서의 합의사항이 한치의 빈 틈이나 차질없이 이행되고 실천될 수 있도록 북측이 보다 큰 誠과 熱을 갖고 대하는 입장과 자세를 보여야 할 것이다.

原子力發電所의 所內負荷의 電源切換에 관한 硏究

黃錫永 단국대학교 1978 論文集 Vol.12 No.-

The analysis on the inrrush current due to a nondelayed interrupted circuit transfer is presented theoritically. The inrrush current is devided into two parts i,e, exciting current and load current. The inrrush current is interpreted to be caused by the initial conditions which are given by the transient behavior of motor group during bus dead time. The motor behavior gives only two conditions i,e, residual exciting flux and load resistance value by motor speed. Under such assumption, the analysis showed that the power source breaker should be closed within to±π/2 of phase angle difference between the source and the bus to reduce the inrrush current and also the vectorial difference of voltage is not always. dominant factor for the inrrush current.