Drosophila melanogaster 韓國 自然集團에 있어서 P-M system에 依據한 系統型 轉換

成耆昌,崔喜慶,金溶聲 성균관대학교 기초과학연구소 1989 論文集 Vol.40 No.1

Isofemale lines of Drosophila melanogaster were established from Daejon in Korea and were examined in order to investigate the changes of cytotype or strain type by P-M system through 1∼15 generations. The results are as follows: 1. Using π_2 (strong P) strains and bw;st (true M) strains as standard strains, the mean sterility frequencies from Cross A were 20.8%∼34.6% for each generations and the mean sterility frequencies from Cross B were 0.0%∼0.3%. 2. Frequency of strain with P cytotype for each generation was analyzed to be 44.8%(G₁), 59.2%(G₂), 43.7%(G₄), 36.7%(G_7), 29.2%(G_10) and 36.7%(G_15). Therefore it was tend to be low as increased with generation number, but the differencies in percentage of GD sterility between each generation are non-significant statistically. 3. Among the isofemale lines, type conversions were observed. Q→M', M'→Q and M'→M changes have occured with frequency of 18.4%, 8.2% and 4.1%, respectively. The remaining lines (69.3%) were unchanged through several generations. 4. The results suggest that Drosophila melanogaster are appeared temporally as a certain strain type in natural population, but the type conversions were represented by interactions between P elements in each genome and cytoplasm for each generation.

인체 체액내 황색포도상구균의 증식과 철 획득 기전

신성희,이강길,이명희,양남웅,임용,김진호 대한감염학회 2000 감염 Vol.32 No.5

주택의 물 사용 공간계획을 위한 주문화 연리 : 조리ㆍ세탁ㆍ목욕 행위를 중심으로

조성희,박수빈 대한건축학회 2004 대한건축학회논문집 Vol.20 No.9

The purpose of this research is to find cultural design principles through the meaning and use of housing in regard to cooking, washing, and bathing. A historical and behavioral study was performed to link the past and the present The meaning and use of places for cooking, washing, and bathing were grasped by literature review In order to figure out principles of space organization for those activities, a questionnaire survey was Carried out The subjects were 646 residents who live in apartments In Busan The residents' attitudes on these Issues were investigated and analyzed The main findings are as follows (1) The kitchen, as a major place for cooking, becomes a center of dwelling space by facing the livingroom The role of the kitchen as a place for eating has become weighty (2) In the past, washing the clothing was carried out outside of the house because It was considered dirty After modernization, It was not easy to place laundry facilities Within the house Today, the design of apartments for household chores needs to be developed according to meaning and use of those spaces (3) Traditionally, bathing was considered to be clean After modernization, the bathroom appeared as a room for bath10g m a house At present, the bathroom becomes a space not only for bathing but also for taking a rest (4) Principles of space organization related to water usage 10 housing were Identified m the classes of dirty/clean, and of edible/not edible

과학 영재를 위한 캠프 운영과 교육 프로그램의 개발 준거

여상인,노석구,강호감,이희순,홍석인,송상헌,정동권 인천교육대학교 과학교육연구소 2003 과학교육논총 Vol.15 No.-

본 연구는 영재 프로그램과 그 운영의 적절성과 타당성을 판단하는데 기초 자료가 될 수 있는 준거를 추출하기 위한 연구이다. 과학캠프 활동 프로그램에 대한 학생들의 흥미와 유익성, 영재캠프 운영에 관련된 문항으로 구성된 설문지를 캠프에 참가한 학생과 그 학부모에게 실시하여 분석하였다. 영재 캠프에 참가한 학생은 직접 참여할 수 있으면서 지적 호기심을 자극하는 활동에 흥미를 느꼈고, 놀이 요소가 포함된 프로그램을 많이 선호하였다. 학생들이 모르거나, 중요하다고 생각하거나, 일상생활에 적용할 수 있는 과학 지식이나 원리를 배웠다고 인식하는 경우, 유익한 프로그램으로 인식하였다. 과학 영재 캠프의 운영에 있어서 많은 학생이 방학 중에 1주일 정도의 기간으로 합숙하는 프로그램 운영 방식을 선호하였다. 이러한 연구 결과를 토대로 본 연구에서는 캠프 활동 프로그램과 운영에 대한 몇 가지 시사점을 제안하였다. This study is to find out criteria and basic data to evaluate effectiveness and validity of program for gifted children in science. To this purpose, a questionnaire to investigate the perception of interest and usefulness for camp activities was administered to the gifted children registered to science camp. By analyzing their responses, we could conclude that the gifted children thought the activities, which stimulating their curiosity or providing opportunities to participate, to be interesting to them. They preferred the activities like a play or a game and considered that a useful activities should have something worth-learning. They and their parents preferred to stay in a camp for a week. Based on this research, we suggested some implications about academic camp program for gifted children in science.

DAF 공정에서 무기 고형입자의 유체역학적 충돌효율과 부상특성

곽동희,김성진,이화경,정흥조,이재욱,정팔진 대한상하수도학회 2002 상하수도학회지 Vol.16 No.6

Separation characteristics of inorganic particles occurred during heavy rainwater were investigated in DAF (dissolved air flotation) process. In order to remove the inorganic particles effectively, the collision and flotation efficiencies were examined from a hydrodynamic point of view. Generally, the collision efficiency increased with floc size under the variation of fluid dynamic conditions including inertial force. However, more precise model should be required to analysis the collision efficiency expressed both the physical properties for inorganic particles and hydrodynamic conditions for a reactor.

海成粘土와 다짐粘土의 透水係數 豫測에 관한 硏究

임희대,이상헌 忠南大學校 産業技術硏究所 1997 산업기술연구논문집 Vol.12 No.2

It is very important for geotechnical engineers to understand properties of coefficient of permeability. The Kozeny-Carman equation is generally used at the present for estimating the coefficient of permeability. Even though the equation proposed by Kozeny-Carman gives fairly good results in estimating of sandy soils. But it is not appropriate for fine-grained soils such as clay. In the case of clayey soils, structure and distribution of particles play and important role in the coefficient of permeability. These structure and distribution are also closely related to specific surface. Large specific surface means that the grain size is very small. Soils possessing large amount of fine grains have a long flow of water. The study comes to the conclusion that the mostly related factor between specific surface and permeability appears to be #200 passing percentage in the case of compacted clays and clay content for marine clay. So new equation is proposed with the two factor in this study. But the developed equation can be used for estimating rough values in the field. That is, it is skeptical to calculate an accurate coefficient of permeability of soils. The other equations proposed until now were considered. But the results of the equations developed by plasticity index or effective grain size are far from the actual value.

수위변동에 따른 필댐의 擧動分析

김성민,임희대 충남대학교 공업교육연구소 2002 論文集 Vol.25 No.1

Accorcing to recent statistics about damage and failure time, failure dams in 5 years after construction are 42.6%, and damage are to come under 29.3%. The primary objective of this paper is to analysis the behavior of rockfill dam due to water table fluctuations. There are many factors which affect the dam failure. One of them is the influence of water table fluctuations. Rockfill dam influenced by cyclic water table fluctuations is hardening, which can be expressed to increasing elastic modulus. Material affected cyclic loading occurs plastic and elastic deformation which actually undergo characteristic changes and is getting larger stiffness. The results of this study are summarized as follows; i) At cyclic loading of fill material test, unloading-reloading modulus number(K_ur) is larger than initial tangential modulus number (K). Modified behavior analysis result of dam considered that and existing behavior analysis result of dam assumed that two value is same, which difference is very little. Therefore unloading -reloading modulus number(K_ur) dose not much affect dam behavior analysis. ii)According to result of FEM analysis, at the rapid drawdown, stress and strain are larger, so that safety of dam decrease. Vertical displacement is more increased in upstream shell than in core, so which differential settlement can cause longitudinal crack. iii) After reservoir filling, due to cyclic water table fluctuations, vertical displacement increasing phenomenon was obvious. All of dams except Dae-chung occur 70% of total settlements in 5 years arter construction and all of dams occur 90% of total settlement in 7 years. iv) In the case of crest settlement, settlement curve appears typical consolidation settlement curve. And crest settlement ratio was converged 0.2%∼0.3% range. The minimum and maximum value was each recorded 0.18% in Daechung and 0.28% in soyanggang.

m-Methylphenyl N-methylcarbamate 유도체들의 살충활성 메카니즘

박승희,남상길,성낙도 충남대학교 농업과학연구소 1995 농업과학연구 Vol.22 No.2

A Series of meta and para-substituted phenyl N-methylcarbamate derivatives were synthesized and influence of substituents(X) on the molecular orbital(MO) quantities of carbonyl group, carbamylation reaction center, and insecticidal activities(pI_50) were discussed quantitatively. From these findings, the most stable streo conformer(Z) shows that the planer phenyl group occupies vertical(θ=90˚) position on the plane of the N-methylcarbamyl group. The carbamylation mechanism was proposed that the carbamylation process of acetylcholinesterase(ACh.E) by m-methyl substituted phenyl N-methylcarbamate derivatives proceeds via hyperconjugation of m-methyl group and carbonyl oxygene protonation, theromodynamically control reaction with acidic site of ACh.E.

Dextranase 함유 구강 세정액의 치태 제거 및 치은염 예방 효과에 관한 임상적 연구

송우성,손성희,정현주 전남대학교 치의학연구소 2001 구강과학 Vol.13 No.3

A novel glucanhydrolase (DXAMase) from a mutant of Lipomyces starkeyi (KSM 22) has been shown effective in hydrolysis of mutan, reduction of mutan formation by Streptococcus mutans and removal pre-formed sucrose-dependent adherent microbial film and DXAMase has been strongly bound to hydroxyapatitie. These in vitro properties of Lipomyces starkeyi DXAMase are desirable for its application as a dental plaque control agent. This study was performed to determine the adjunctive oral hygiene benefits and safety of dextranase (Lipomyces starkeyi KSM 22 DXAMase)-containing mouthwash when used alongside normal toothbrushing. This 6-month clinical trial was placebo-controlled double-blind design evaluating 1U/㎖ dextranase mouthwash and 0.12% chlorhexidine mouthwash. A total 39 systemically healthy subjects, who had moderate levels of plaque and gingivitis were included. At baseline, 1, 3 and 6 months, subjects were scored for plaque accumulation(Turesky modification of Quigley-Hein's plaque index), gingivitis status (Lo¨e and Silness gingival index), and tooth stain(Area and severity index system by Lang et al). Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Two weeks after pre-experiment examinations and a professional prophylaxis, the subjects were provided with allocated mousewash and instructed to use 20-ml volumes for 30s twice daily after toothbrushing. All the groups showed significant increase in plaque accumulation since 1 month of experiment. During 6 month's period, the Dextranase mouthwash group showed the least increase in plaque accumulation, compared to the Chlorhexidine mouthwash and placebo groups. As for gingival inflammation, all the groups showed significant increase during 6 months of experiment. The Experimental group (Dextranase mouthwash) also showed the least increase in gingival index score, compared to the Positive control (Chlorhexidine mouthwash) as well as the Negative control (placebo) groups. Whereas the tooth stain was increased significantly in the Positive control group, compared to the baseline score and the Negative control group since 3 months of mouthrinsing. It was significantly increased after 6 months in the Experimental group, still less severe than the Positive control group. As for the oral side effect, the Experimental group showed less tongue accumulation, bad taste, compared to the Positive control group. From these results, mouthrinsing with Lipomyces starkeyi KSM 22 dextranase provided adjunctive benefits to toothbrushing, comparable to 0.12% chlorhexidine mouthwash in inhibition of plaque accumulation and gingival inflammation and local side effects were if anything less frequent and less intense than chlorhexidine, with long-term use of the mouthwash. All data had provided positive evidence for Lipomyces starkeyi KSM 22 dextranase as an antiplaque agent and suggested that further development of dextranase formulations for plaque control are warranted.

Rockfill 댐의 Hydraulic Fracturing에 關한 硏究

임희대,우원재,우상태 忠南大學校 産業技術硏究所 1995 산업기술연구논문집 Vol.10 No.2

The term hydraulic fracturing has been used in the geotechnical engineering literature to describe situations in earth embankment dams where the reservoir water pressure initiates and propagates a cracks. The term has also been used in situations where an existing crack is further widened by the reservoir water pressure. The mechanisms of hydraulic fracturing in the core of rockfill dams that have been proposed to date are quite qualitative and have been postulated in the course of investigations to find the causes of leakage or failures as a results of internal erosion. In this study, the various mechanisms of hydraulic fracturing are outlined and the finite element analyses of 5 representative rockfill dams in Korea were conducted to examine the assumption that hydraulic fracturing occurs in embankment cores when the reservoir water pressure exceeds the total normal stresses. This numerical analyses use the hyperbolic model and its parameters from the conventional triaxial tests. As the results of the analyses, the total normal stresses by FEM exceed the water pressures in most cases which is contray to the fact that the water pressures exceed the total normal stresses by the pressure meters in the case of Soyanggang dam.