• Information Display
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• v.23 no.4
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• pp.12-21
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• 2022

반도체 기반 양자점 (QD)소재와 CsPbX3 (X=Cl, Br, I)기반 perovskite 양자점 또는 나노결정 소재(PNC)는 매우 우수한 양자효율과 좁은 발광 선폭으로 고색재현성 디스플레이 색변환 소재 또는 발광 소재로서 각광을 받고 있다. 그러나, 기존 화학적 합성법을 통해 제조되는 QD 및 PNC 소재는 취약한 열 및 화학적 안정성으로 인해 장기 내구성의 개선이 요구된다. 이들 QD 및 PNC 소재는 모두 완전 무기 소재인 산화물 기반 유리 소재내에 생성이 가능하며, 이를 통해 장기 내구성을 근본적으로 개선할 수 있다. 반도체 기반 QD 함유 유리소재 (QDEG)의 경우, 유리 내 core/shell 구조를 가진 QD의 생성으로 양자효율의 향상이 가능했으나, 콜로이드 기반 양자점 (cQD)과 달리 다중 shell의 형성이 어려워 양자효율이 제한되고, 발광 선폭이 넓어 고색재현성 디스플레이용 색변환 소재로 적용되기에는 아직 한계가 있다. 한편, Perovskite 양자점 (또는 나노결정) 함유 유리소재 (PNEG) 소재는 QDEG과 달리 콜로이드 기반의 PNC (c-PNC)가 가지는 우수한 양자효율과 20 nm 수준의 좁은 선폭을 유리 내에서도 가지며, c-PNC 대비 열적, 화학적 및 광학적 안정성이 획기적으로 향상되어 실질적인 응용 가능성을 높이고 있다. 특히, 일반적인 용융-급랭법으로 제조하여 대량생산에 용이하고, 분말 또는 판상 등 다양한 형태로의 제작이 가능한 장점이 있다. 현재까지 제조된 PNEG의 최대 PL-QY는 450 nm 여기 시 녹색 및 적색에서 약 60% 수준이며, Al₂O₃ 분말을 이용할 경우 최대 80% 수준까지 달성이 가능하다. 또한, PNEG과 blue LED를 이용하여 백색 LED를 구현할 경우 color filter를 적용하지 않을 때, NTSC 대비 최대 약 130 % 수준의 높은 색재현 영역을 보여 주고 있으며, 실제 LCD용 BLU로 적용 시 기존 상용 c-QD 소재와 동등 이상의 색재현 영역을 보이고 있어, 실질적인 응용 가능성이 매우 높음을 확인하였다. PNEG의 상업적인 응용을 위해서는 몇 가지 추가적인 연구 개발이 필요하다. 기존 c-QD 또는 c-PNC는 나노 수준 크기의 입자가 액상에 분산된 형태로 입도 제어가 용이하나, PNEG의 경우 분말 제조 시 유리 형성 후 분쇄를 통해 제조되며, 입도가 대개 수십 ㎛ 이하로 작아질 경우 PL-QY가 저하되어, 향후 잉크젯 공정 응용을 위해서는 고효율의 분말 제조공정 개발이 필요하다. 또한, 유리 소재의 경우 절연체로서 기존 QD 소재 대비 electro-luminescence(EL) 소자의 활성층으로 사용하는데 제약이 있어 PNEG을 이용한 EL 소자 제작에 대한 연구도 필요하다. 마지막으로, 기존 c-PNC 소재와 같이 Pb가 함유되지 않은 PNEG 소재의 개발이 선결되어야 할 것으로 판단된다. 이와 같은 해결 과제들에도 불구하고, PNEG 소재는 기존 c-QD 소재 대비 매우 우수한 안정성을 기반으로 고품위 고색재현 디스플레이용 색변환 소재로서 다양한 응용에 활용될 수 있을 것으로 기대된다.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.13-22
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• 1977

The following results were obtained in this work intended for getting more informations on features of phosphorus in Korean characteristic virgin, upland and paddy soils for knowing the ways how to evaluate the soil phosphorus availability and utilize fertilizers efficiently. 1. A large part of soil phosphorus is occupied by inorganic phosphorus in the soils of which the cultivated soils showed higher accumulation of applied phosphorus as inorganic forms than the uncultivated soils. The accumulation of organic phosphorus was indicated the highest in the paddy soils, and the lowest in the uncultivated soils. Than the cultuivated soil, the uncultivated soils have higher C/P ratio which was estimated to be related to soil fertility status essentially. 2. Iron phosphate was shown to be the most dominant form in soil phosphorus. Difference in parent rocks, from which the soils were originated, was shown to affect the carious distribution of phosphorus forms in the uncultivated soils to a large extent. The paddy soils have almost same distribution pattern of soil phosphorus forms regardless of different parent rocks. 3. The different methods for available phosphorus estimation extracted different amounts of phosphorus from the soils. Close relations between the available phosphours extracted with the different methods and the amounts of seil inorganic phosphorus were shown : e.g. between Fe-P and available-P by Olsen method. 4. Phosphorus absorption coefficient correlated negatively to soil inorganic phosphorus, and also to available phosphorus extracted with the several methods.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.183-183
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• 2009

OLED소자의 양극재료로써 현재는 산화인듐주석(ITO : indium tin oxide) 박막이 널리 이용되고 있다. 그러나 낮은 전기 비저항과 높은 투과도를 갖는 ITO 박막을 얻기 위해서는 $300^{\circ}C$ 이상의 고온에서 성막되어야 하며, 원료 물질인 인듐의 수급량 부족으로 인한 문제점과 독성, 저온증착의 어려움, 스퍼터링 시 음이온 충격에 의한 막 손상으로 저항의 증가의 문제점이 있고, 또한 유기발광소자의 투명전극으로 쓰일 경우에 유기물과의 계면 부적합성, 액정디스플레이의 투명전극으로 사용될 경우에 $400^{\circ}C$정도의 놓은 온도와 수소 플라즈마 분위기에서 장시간 노출 시 열화로 인한 광학적 특성변화가 문제가 된다. 이러한 문제점을 지닌 ITO 박막을 대체할 수 있는 물질로 산화 인듐아연(lZO) 박막이 많은 각광을 받고 있다. IZO(Indium Zinc Oxide) 박막은 저온 ($100^{\circ}C$ 이상)에서 증착이 가능하고 추가적인 열처리 없이도 가시광 영역에서 90% 이상의 광 투과도와 ${\sim}10^{-4}{\Omega}cm$ 이하의 낳은 전기 비저항을 갖는 것으로 알려져 있다. 이러한 IZO박막은 성막 후 고온의 열처리 과정이 필요 없기 때문에 폴리카보네이트와 같은 유기물 기판을 사용하여 제작 가능한 유연한 평판형 표시 소자의 제작에도 적용될 수 있다. IZO(Indium Zinc Oxide) 박막은 상온 공정에서도 우수한 전기적, 광학적, 표면 특성을 나타낼 뿐만 아니라 양극재료로써 높은 일함수를 가지고 있어 고효율의 유기 발광 소자를 구현하는데 유리한 재료라 판단된다. 본 연구에서는 TCO 박막의 면 저항과 표면 거칠기가 OLED 소자의 성능에 미치는 영향을 조사하였다. R.F Magnetron Sputtering을 이용하여 투명 전도막을 성막 형성 하였으며, 기판온도와 증착과정에서 주입되는 산소, 수소의 유랑 변화가 박막의 구조적, 전기적 특성에 어떠한 영향 미치는 것인가를 자세히 규명하였다 ITO 와 IZO박막은 챔버 내 다양한 가스 분위기(Ar, $Ar+O_2$ and $Ar+H_2$) 에서 R.F Magnetron Sputtering 방법으로 증착했다. TCO박막의 구조적인 이해를 돕기 위해서 X-ray diffraction 과 FESEM으로 분석했다. 광학적 투과도와 박막의 두께는 Ultraviolet Spectrophotometer(Varian, cary-500)와 Surface profile mersurement system으로 각각 측정하였다. 면저항, charge carrier농도, 그리고 TCO박막의 이동성과 길은 전기적특성은 Four-point probe와 Hall Effect Measurement(HMS-3000)로 각각 측정한다. TCO 박막의 표면 거칠기에 따른 OLED소자의 성능분석 측면에서는 TCO 박막의 표면 거칠기 조절을 위해 photo lithography 공정을 사용하여 TCO 박막을 에칭 하였다. 미세사이즈 패턴 마스크가 사용되고 에칭의 깊이는 에칭시간에 따라 조절한다. TCO박막의 표면 형태는 FESEM과 AFM으로 관찰하고 그리고 나서 유기메탈과 음극 전극을 연속적으로 TCO 박막위에 증착한다. 투명전극으로 사용되는 IZO기판 상용화를 위해 IZO기판 위에 $\alpha$-NPB, Alq3, LiF, Al순서로 OLED소자를 제작하였다. 전류밀도와 전압 그리고 발광과 OLED소자의 전압과 같은 전기적 특성은 Spectrometer (minolta CS-1000A) 에 의하여 I-V-L분석을 했다.

• Journal of Conservation Science
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• v.33 no.5
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• pp.331-344
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• 2017

In this study, glass beads from Osan Sucheong were classified according to color into 10 groups. Among these groups, reddish brown, bluish green, and purplish blue were identified as the main colors of glass beads based on their large quantities in Osan Sucheong. The glass beads of these main colors were then classified according to their chemical compositions and and looked at the changing process. Based on the results, reddish brown and bluish green glass beads can both be divided into five types, and purplish blue glass beads can be divided into four types. Furthermore, according to continuity of type, it was identified as the main attributes that the reddish brown beads belong to two types, whereas the bluish green and purplish blue each belong to one type. Based on a review of primary attributes, beads of these three colors were identified as soda glass and high-alumina glass. The results indicate that these beads came from a single, consistent route of origin into the region. However, it is possible that glass beads came through various routes into Osan Sucheong in the $4^{th}$ century, because many types of chemical compositions have been detected for beads from this time.

• Research in Community and Public Health Nursing
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• v.9 no.2
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• pp.502-517
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• 1998

This research intends to survey family environment, health behavior and health status of the students in urban-rural elementary schools and analyze those factors comparatively, and use the result as basic material for school health teacher to teach health education in connection with family and regional areas. It also intends to improve a pupil's self-abilitiy in health care. The subjects involve 2,774 students of urban elementary schools and 583 student in rural ones, who were selected by means of a multi -stage probability sampling. Using the questionnaire and school documents, we collected data on family environment, health behavior and health status for 19 days. Feb. 2nd 1998 through Feb. 20th 1998. The R -form of Family Environment Scale (Moos, 1974) was used in the analysis of family environment(Cronbach's Alpha =0.80). Questionnaires of Health Behavior in School-aged children used by the WHO in Europe(Aaro et al., 1986) and the ones developed by the Health Promotion Committee of the Western Pacific(WHO, 1995)(adapted by long Young-suk and Moon Young-hee(1996)) were used in the analysis of health behavior, as well documents on absences due to sickness, school health room-visits, levels of physical strength, height, weight and degree of obesity were used to determine health status. In next step, We used them with an $X^2$-test, t-test, Odds Ratio, and a 95% Confidence Interval. 1. In two dimensions of three, family-relationship (t=3.41, p=0.001) and system -maintenances(t= 2.41, p=0.0l6) the mean score of urban children were significantly higher than those of rural ones. In the personal development dimension however, there was little significant difference. Assorting family environment into 10 sub-fields and analyzing them, we recognized that urban children were superior to rural children in the sub-fields of expressiveness (t =3.47, p=0.001), conflict (t=0.48, p=0.001), active-recreational orientation (t = 1.97, p=0.049) and organization (t=4.33, p=0.000). 2. Referring to the Odds Ratios of urban-rural children's health behaviors, urban children set up more desirable behavior than rural children wear ing safety belts (Odds Ratio =0.32, p=0.000), washing hands after meals(Odds Ratio = 0.43, p= 0.000), washing hands after excreting (Odds Ratio = 0.39, p=O.OOO), washing hands after coming - home ( Odds Ratio = 0.75, p = 0.003), brushing teeth before sleeping(Odds Ratio =0.45, p=0.000), brushing teeth more than once a day (Odds Ratio =0.73, p=0.0l2), drinking boiled water (Odds Ratio = 0.49, p=0.000), collecting garbage at home(Odds Ratio=0.31, p=0.000) and in the school(Odds Ratio =0. 67, p=0.000). All these led to significant differences. As to taking milk(Odds Ratio = 1.50, p=0.000), taking care of eyesight(Odds Ratio=1.41, p=0.001) and getting physical exercise in(Odds Ratio = 1.33, p=0.0l9) and outside the school(Odds Ratio = 1.32, p=0.005), rural children had more desirable behavior which also revealed a significant difference. There was little significant difference in smoking, but the smoking rate of rural children(5.5%) was larger than that of urban children(3.9%). 3. Health status was analyzed in terms of absences, school health room-visits, levels of physical strength, and the degree of obesity, height and weight. Considering Odds Ratios of the health status of urban-rural children, the health status of rural children was significantly better than that of the urban ones in the level of physical strength(t=1.51, p=0.000) and the degree of obesity(t=1.84, p=0.000). The mean height of urban children ($150.4{\pm}7.5cm$) is taller than that of their counterparts($149.5{\pm}7.9$), which revealed a significant difference (t =2.47, p=0.0l4). The mean weight of urban children($42.9{\pm}8.6kg$) is larger than that of their counterparts($41.8{\pm}9.0kg$), which was also a significant difference(t=2.81, p=0.005). Considering the results above, we can recognize that there are significant differences in family environment, health behavior, and health status in urban-rural children. These results also suggestion ideas for health education. What we would suggest for the health program of elementary schools is that school health teachers should play an active role in promoting the need and importance of health education, develop the appropriate programs which correspond to the regional characteristics, and incorporate them into schools to improve children's ability to manage their own health management.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.186-199
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• 1997

The soils derived from granite gneiss occupy almost one third of the land area in Korea. The soils under forest vegetation, formed on granite gneiss, in Sun chon-shi, Chollanam-do in southern part of Korea, were studied to evaluate the weathering and the transformation of primary minerals into secondary minerals, clay minerals. The studied soils contained large amounts of ferromagnesian minerals, weathered biotites and were well weathered, strongly acid and low in organic matters and in ration exchange capacity. The clay contents in the Bt horizon were almost two times higher than those in the C horizon. The O horizon had a thin layer which consisted of a little decomposed plant components with a granic fabric and high porosity, and showed the micromorphological characteristics of moder humus. The related distribution pattern of the E horizon were enaulic and large amounts of silts and small amounts of sand grains were another characteristics of the E horizon. The most striking micromorphological features were multilaminated clay coating and infillings in the voids in the Bt and C horizons, and generally limpid ferriargillans ejected from the biotites and imparted red color to the soils in the Bt horizon. High clay contents in the Bt horizon was not only due to clay translocation, but also due to intensive in situ mineral weathering in this horizon. The most significant pedogenic process, revealed by the petrographic microscope and SEM, was the formation of iron oxides from biotites, the formation of tubular halloysites and the weathering models of biotites; wedge weathering and layer weathering. The thick coating on the weathering biotites showed the characteristics of the weathering process and the synthetic hematites were revealed in clays by TEM. Total chemical analysis of clays revealed extensive loss of Ca, and Na and the concentration of Fe and Al. Mineralogical studies of clays by XRD showed that micas were almost completely weathered to kaolinite, vermiculite-kaolinite intergrade, hematite, gibbsite, while halloysites from other primary minerals. Some dioctahedral mica appeared to be resistant in the soils. Parent rock of the soils contained a considerable amounts of biotites and this forest soils showed especially a dominant characteristics of biotite weathering.

• Journal of the Mineralogical Society of Korea
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• v.26 no.2
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• pp.101-110
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• 2013

Due to the large specific surface area and great reactivity toward environmental contaminants, nanocrystalline mackinawite (FeS) has been widely applied for the remediation of contaminated groundwater and soil. Furthermore, nanocrystalline FeS is rather thermodynamically stable against anoxic corrosion, and its reactivity can be regenerated continuously by the activity of sulfate-reducing bacteria. However, nanocrystalline mackinawite is prone to either spread out along the groundwater flow or cause pore clogging in aquifers by particle aggregation. Accordingly, this mineral should be modified for the application of permeable reactive barriers (PRBs). In this study, coating methods were investigated by which mackinawite nanoparticles were deposited on the surface of alumina or activated alumina. The amount of FeS coating was found to significantly vary with pH, with the highest amount occurring at pH ~6.9 for both minerals. At this pH, the surfaces of mackinawite and alumina (or activated alumina) were oppositely charged, with the resultant electrostatic attraction making the coating highly effective. At this pH, the coating amounts by alumina and activated alumina were 0.038 and 0.114 $mmol{\cdot}FeS/g$, respectively. Under anoxic conditions, arsenite sorption experiments were conducted with uncoated alumina, uncoated activated alumina, and both minerals coated with FeS at the optimal pH for comparison of their reactivity. Uncoated activated alumina showed the higher arsenite removal compared to uncoated alumina. Notably, the arsenite sorption capacity of activated alumina was little changed by the coating with FeS. This might be attributed to the abundance of highly reactive hydroxyl functional groups (${\equiv}$AlOH) on the surface of activated alumina, making the arsenite sorption by the coated FeS unnoticeable. In contrast, the arsenite sorption capacity of alumina was found to increase substantially by the FeS coating. This was due to the consumption of the surface hydroxyl functional groups on the alumina surface and the subsequent occurrence of As(III) sorption by the coated FeS. Alumina, on the surface area basis, has about 8 times higher FeS coating amount and higher As(III) sorption capacity than silica. This study indicates that alumina is a better candidate than silica for the coating of nanocrystalline mackinawite.

• Animal Systematics, Evolution and Diversity
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• v.9 no.2
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• pp.151-170
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• 1993

Morphometric, band-pattern and electrophoretic analysis on Cobitis taenia complex were performed to investigate the morphological and genetic differentiation and to clarify their taxonomic status. Intermediate types of band-pattern (C and D type) were more frequently expressed than that of types of C. t. taenia(type A) and C. t. lutheri (type B). Sexual dimorphism of band-pattern was observed not only in C. t. taenia(type A) and C. t. lutheri(type B). Sexual dimorphism of band-pattern was observed not only in C. t. lutheri but also in C. t. taenia and C. t. striata as well. Discriminant function analysis based on 19 morphological characters shows no significant differences among C. taenia complex. The degree of genic variation of C. t. striata was higher ( =1.48, P=31.2%, HD=0.009) than those of C. t. striata was higher( =1.48, P=31.2%, HD=0.082 and HG=0.009) than those of C. t. lutheri ( =1.37, P=2.7%, HD=0.058 and HG=0.065). The average genetic similarities between C. t. lutheri and C. t. taenia-C. t. striata were S=0.62 and S=0.66 respectively and these values indicate that C. t. tanenia has evolved specific level of differentiation. C. t. striata and C. t. lutheri show subspecifc level of close genetic similarity (S=0.82). Based on the divergent time estimate (Nei, 1975) it is assumed that C. t. tanenia was branched off from the other subspecies about two million years before present (MYBP) and C. t. striata and C. t. lutheri were differentiated about 0.6 MYBP. The use of C. sinesis an the scientific name for the Korean C. t. taenia, proposed by Kim and Lee (1988) seems incorrect since they are quite different in the structure of lamina circularis (Vladycov, 1935), the external morphology and distribution (Cheng and Zheng, 1987) and the chromosome number(Yu et al., 1989). Kim and Lee(1988) also argued that C.t. striata and C. t. lutheri should be treated as distinct species but the present study and other reports (Kim and Lee, 1984; Kim and Yang, 1993) do not support it. We conclude that C. t. taenia is a good species and C. t. striata and C. t. lutheri are subspecific status. Their scientific names should be revised in the future.

• Korean Journal of Veterinary Research
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• v.10 no.1
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• pp.11-23
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• 1970

Recently Carter(1952) reported the capsule antigens of Pasteurella multocida could be divided into four serological types A,B,C and D by means of precipitation tests. Subsequently he showed that the most sensitive for identification of these types involved the use of capsule substance adsorbed by erythrocytes in hemagglutination test. It may be somewhat difficult to conduct the hemagglutination test in small laboratory, because relatively large amounts of antisera and erythrocytes of the human O type are required for the test. A simple method for serological typing of P. multocida was the slide agglutination test employed by Little et al. (1943) and Namioka et al. (1962), but this method is still in controversy. The author tried adapting Carter's hemagglutination method to the slide method so called "micromethod technique", and studied on the stabilization of erythrocytes for use of slide hemagglutination to P. multocida although many invesigators reported the stabilization of erythrocytes. The results obtained are summarized as follows: 1. A simplified method (slide method) for capsule typing of the organism was developed by adapting Carter's hemagglutination reaction(tube method). Antibody-containing serum can be diluted serially on Boerner's microtest slide with capillary or serological pipetts with a considerable accuracy. The slide reaction can be carried out with case on the slide by adding $0.05m{\ell}$ of antigen-sensitized erythrocytes suspension diluted to one percent on $0.05m{\ell}$ of serially diluted antibody-containing sera, and the final result can be read after 60 minutes at the room temperature ($15^{\circ}C$). 2. It is difficult to determine superiority of inferiority between the slide method and the tube method on the pattern of the reaction of hemagglutination. 3. The pH range of 6.6 to 8.3 is optimal for the slide hemagglutination reaction. 4. The antigen-sensitization against erythrocytes at $37^{\circ}C$ is optimal for the slide hemagglutination. 5. Both the doses and concentration of antigen do not influence the antigen-adsorbing capacity of erythrocytes. 6. The reduction of antigen-sensitizing hours does not influence the antigen-adsorbing capacity of erythrocytes even 30 minutes. 7. The tannic acid treatment against formalinized and non-formalinized erythrocytes showed no effect on the reaction of hemagglutination. 8. The erythrocytes preserved at $4^{\circ}C$ in the ACD solution do not decrease the reactivity on the reaction of hemagglutination for 60 days, while they begin slight hemolysis 30 days after preserving. 9. The stable preparation of erythrocytes can be obtained by treating the cells at $37^{\circ}C$ for 20 hours with from 4 to 8 percent of formalin in saline or buffer. These cells can be preserved at $4^{\circ}C$ for more than 8 months experimented without hemolysis. With low concentration of formalin, the cells were not sufficiently stabilized resulting in the hemolysis after short period of preservation at $4^{\circ}C$. 10. The erythrocytes treated with 16 percent of formalin remain constantly or increase the reactivity for the reaction of hemagglutination. On the contrary, the cells treated with I to 8 percent of formalin decrease the reactivity. 11. There is no difference between nontreated fresh erythrocytes and the erythrocytes preserved in the ACD solution on the reactivity against the hemagglutination, and the erythrocytes treated with 16 percent of formalin showed the reactivity of higher level than that of the above two kinds of erythrocytes. 12. There is no difference between the saline and the isotonic buffer solution on the reaction of hemagglutination.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.144-157
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• 1992

The study was conducted to compare the interprete methods and examine the feasibility of mixture use of oxyfluorfen and bensulfuron in controlling principal Paddy weeds, annuals and perennials. Application ratio of both chemicals were obtained from the combinations of 5 levels(0, 5, 10, 15, 20 g ai/ha) of each chemicals, respectively. All the treatments were applied at 5 days after transplanting and water was maintained at 3.0cm in depth. Shoot fresh-weight of weeds was assessed at 35 days after treatments. Data obtained was analysed by Colby, Isobole, Calculus, Regression and EQM method, respectively. The results from the analysis of variance on the principal weeds treated with oxyfluorfen and bensulfuron showed significant interactions at 1% level on both Echinochloa crus-galli and Eleocharis Kuroguwai, and total species at 0.5% level on both Potamogeton distinctus and Cyperus serotinus, but non significant on Scirpus juncoides and Sagittaria pygmaea. Thereafter, the results of the models applied to Echinochloa crus-galli, Eleocharis kuroguwai and total species were as follows ; 1. The Colby method gave values nearly identical to regression estimate method (both multiplicative models) as provided by Akobundu et al. The Colby method and Regression method indicated synergistic toward Echinochloa curs-galli, and total species, but antagonistic toward Eleocharis kuroguwai. 2. The Isobole method shows synergism on Echinochloa crus-galli at $ID_{50}$, and total species at $ID_{60}$ on Eleochari kuroguwai. 3. The Calculus method gave positive signs for the first differentiation and negative signs for the second differentiation except for some rates on Echinochloa crus-galli and total species, but reverse on Eleocharis kuroguwai. These result does not agree with the observed values. 4. ${\theta}$ value from the EQM method was greater than one at all combinations. This result was quite different from those of other methods. 5. The various models did not show the same results, but mixture of oxyfluorfen and bensulfuron tend to have synergistic effect. Weeding effect also was high. Treatment in terms of two chemical combination was expected to reduce rates, and to enhence weeding efficacy compared with single treatment.