• Korean Journal of Weed Science
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• v.10 no.4
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• pp.277-284
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• 1990

The response of rice (Oryza sativa L.) cultivars to mixtures of 2, 4-D(2, 4-dichlorophenoxyacetic acid) and other herbicides was investigated to determine if there was an interaction between them. When 2, 4-D was applied, shoot growth of Taipei 309 was more affected than that of IR28 at all concentrations used. In contrast, when thiobencarb (S-[(4-chlorophenyl)methyl]diethylcarbamothioate), butachlor [N-(buthoxymethyl) -2-chloro-N-(2, 6-diethylphenyl) acetamide], and glyphosate [N-(phosphonomethyl)glycine] were applied, the shoot growth of Taipei 309 was less affected than that of IR28 at all herbicide concentrations. Combination of 2, 4-D and the lowest thiobencarb concentration was antagonistic for shoot length for both cultivars, but at higher concentrations, it was synergistic. Synergism for shoot fresh weight between 2, 4-D and thiobencarb was observed with IR28 at all concentrations but, for Taipei 309, synergism was observed only at lower 2, 4-D concentrations. Mixing 2. 4-D with butachlor resulted in greater inhibition in shoot length and fresh weight of IR28 than Taipei 309 at all concentrations indicating a synergistic interaction. With combinations of 2, 4-D and glyphosate, an antagonistic interaction for shoot length was observed for both cultivars. A synergistic interaction for shoot fresh weight was observed with IR28 when combinations of the highest concentration of glyphosate and 2, 4-D were applied but there was an antagonistic interaction with Taipei 309.

• Korean journal of applied entomology
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• v.26 no.3 s.72
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• pp.151-157
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• 1987

The toxicities of binary mixtures of the four insecticides acephate, demeton-S-methyl, cypermethrin and pirimicarb to the two strains of green peach aphid (Myzus persicae Sulz.) resistant to acephate and demeton-S-methyl were investigated and compared to the toxicities of their individual insecticides. The synergistic action of the insecticide mixtures to the insects were greatly varied with the kind of insecticide combinations, their mixture ratios, and the origin of resistance by an insecticide. The maximum synergistic action of acephate for the acephate resistant strain was obtained at 1:1 mixed with demeton-S-methyl. However, there were some antagonistic effects in all acephate mixtures with pirimicarb and cypermethrin. With the strain of demeton-S-methyl resistance, acephate, cypermethrin, and pirimicarb were synergized at the given mixture ratios by demeton-S-methyl. The maximum synergistic effect was observed at 2:3 with acephate, 1:1 with cypermethrin and 3:2 with pirimicarb.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.436-437
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• 2003

고형오구의 분산안정화 작용은 고체 입자의 계면에 흡착한 계면활성제에 의한 전기적 반발력과 입체적 보호작용에 영향을 받게 된다. 특히 현재 시판세제의 조성에서 비이온계 계면활성제의 혼합이 점차 중요시되는 이때 입체적 보호작용에 의한 고형오구의 분산안정성은 의류제품의 세척성 제고에 좋은 정보가 되리라 생각된다. 따라서 본 연구는 시판되고 있는 세제 대부분이 음-비이온계 계면활성제의 혼합으로 되어 있는 점을 고려하여 음이온 계면활성제로서 D5S(sodium dodecyl benzene sulfonate), 비이온계 계면활성계 NPE(nonyl phenol polyoxyethylene ether, EO$_{10}$) 혼합용액에서 음이온과 비이온계 계면활성제의 입자에의 흡착과 고형오구의 안정성을 관련시켜 고찰하였다. (중략)

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.187-193
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• 1985

The experiment was carried out to evaluated the interaction between perfluidone(2-methyl-4-phenylsulphonyltrifluoromethylsulphoanilide) and bifenox(2,4-dichlorophenyl-3-methoxycarbonyl-4-nitrophenylether). A synergistic effect was found between perfluidone and bifenox. The highest synergistic effect on Echinochloa crus-galli (L.). Beauv. was obtained when 10 g a.i./10a of perfluidone was combined with 24.9 g a.i./10a of bifenox. However, bifenox should be increased to 33.3, g a.i./10a to obtain the highest synergistic effect when applied to Cyperus serotinus Rottb. at 1.0-1.5 leaf stage. Sagittaria pygmaea Miq. at 0.5-1.0sleaf stage was completely controlled by the lowest combination rate employed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.9
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• pp.853-860
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• 2017

To evaluate the effects of mode II on the crack initiation and propagation stages, the effects in the fatigue threshold region under a mixed-mode I+II loading state was experimentally investigated. In the case of mixed-mode I + II, during the crack initiation stage, as the loading application angle (${\theta}$) increased, cracks occurred in the lower load owing to the effects of mode II, while the crack propagation rate decreased. The effects of mode II were experimentally investigated in the crack propagation stage by means of multilevel loading direction variation. Following mixed-mode I+II ($0^{\circ}{\rightarrow}{\theta}{\rightarrow}60^{\circ}$), as the load application angle increased, the fatigue crack propagation rate decreased, as did the fatigue crack propagation rate, which occurred later. Following mixed-mode I + II in case of(${\theta}{\geq}75^{\circ}$), the fatigue crack propagation rate was found to increase, while the fatigue life decreased.

• The Journal of the Petrological Society of Korea
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• v.25 no.4
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• pp.349-360
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• 2016

The Bunam Stock ($29.5km^2$ area) is an outcrop of plutonic complex classified four facies: coarse-grained granite, quartz monzodiorite, granodiorite and fine-grained granite. Three facies except the last one exhibit very irregular boundaries with gradational compositional variations between both facies and show concentric zoning from the central quartz monzodiorite through granodiorite to outer coarse-grained granite. Mafic microgranular enclaves (MME) commonly occur in granodiorite. Some MMEs, have very fine-grained chilled margins and indentedly crenulate contacts, and display horizontally circular and vertically elongate shapes. Their shape and granularity indicate coeval flow and mingling of partly crystalline felsic and mafic magmas. MMEs exhibit dark fine-grained margins giving them a ellipsoidal form that has been attributed to undercooling of a mafic magma as blobs intruded into a felsic magma. The observed relations in the Bunam Stock identify that two endmembers are coarse-grained granite from a felsic magma and quartz monzodiorite from a mafic magma, and hybrid is granodiorite including MMEs. So they exhibit concentric zoning that lays the center on the mafic endmember due to magma mixing at the contacts of two magmas, when mafic magma injected into felsic magma. Thus the quartz monzodiorite may probably represent an ancient conduit of mafic magma transport through a granitic magma chamber. Mafic magma would rise through the conduit in which favorable conditions for magma mixing occurred. All these features suggest that they formed from mixing processes of calc-alkaline magma in the Bunam Stock.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.155-163
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• 1985

Three pyrazole-herbicides, pyrazolate, pyrazoxyfene and benzophenap, were evaluated for their interaction in controlling barnyardgrass (Echinochloa crusgalli) with two chloroacetamide-herbicides, butachlor and pretilachlor. Percent inhibition of barnyardgrass growth by pyrazolate, pyrazoxyfene, and benzophenap was 44%, 64%, and 0%, respectively, when each was applied at the 1.5 leaf-stage of barnyardgrass at a rate of 3㎏ ai per ㏊ as single treatment, and the benzophenap showed 60% inhibition when it was applied at the coleoptile stage. While the lowest rate controlling the 1.5 leaf-stage barnyardgrasses by 98 to 100% of the butachlor and pretilachlor was 1.5㎏ and 200g per ㏊, respectively. All of the combinations of pyrazolate with butachlor, pyrazoxyfene with pretilachlor, and benzophenap with butachlor have shown synergistic interaction in controlling barnyardgrass on the Chisaka's isobole of 90% growth inhibition as well as on the Colby`s interaction efficacy data; synergism indices were 2.44, 1.62 and 1.52 in order. The dose combinations shown the maximal synergism were 1870g of pyrazolate with 140g of butachlor (1:0.075), 33008 of pyrazoxyfene with 338 of pretilachlor (1:0.01), and 3350g of benzophenap with 520g of butachlor (1:0.15) on the ai/㏊ basis.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.164-168
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• 1985

In order to enhance herbicidal efficacy of amide and diazine herbicides, synergistic effects of pretilachlor and pyrazoxyfene or butachlor and pyrazolate on control of Cyperus serotinus were determined by isobole method. Interaction indices(I) between pretilachlor and pyrazoxyfene treated at 0 and 3rd leaf stage were 2.64 and 2.07 and hence showed synergistic effect for control of Cyperus serotinus. The points indicated Imax between pretilachlor and pyrazoxyfene were 0.7:1.3 g ai/a and 9.0:20.5 g ai/a at 0 and 3rd leaf stage, respectively. Combination of butachlor and pyrazolate showed synergistic effect(1=1.57) on control of Cyperus serorinus and point indicated Imax was 48.0:20.9 g ai/a.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.279-286
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• 1999

Wall-bounded 유동과 달리 자유 전단 유동은 Hyperbolic Tangent Profile을 가지고 비점성 불안정에 의해 지배된다. 따라서 자유 전단 유동에서 난류로의 천이과정은 비점성 불안정성 이론에 의해 해석되어 진다. 본 연구는 분리판(Splitter plate)에 의해 분리된 속도가 다른 자유 유속의 혼합에 의해 형성되는 혼합층에서 와류병합과정에 대한 속도비의 영향에 대하여 연구한다. 속도비는, R, $ \frac{U_1-U_2}{U_1+U_2}$ 로 정의되며, 여기서 $U_1$은 분리판 위에서의 자유 유속을 그리고 $U_2$ 는 분리판 아래에서의 자유 유속을 나타낸다. 본 연구에서 와류구조의 병합작용을 분석하기 위하여 2차원 비정상 Large-Eddy Simulation 방법을 적용하였다. 속도비의 변화에 따라 혼합층에서 불안정 Wave가 성장하게 되고, 유체는 2차원 와류구조에서 Roll-up한다. 이러한 2차원 와류구조는 주위의 다른 와류구조와 상호작용을 하게 되고 하나의 커다란 와류구조를 형성하는 것을 볼 수 있다. 혼합층에서 와류병합과정은 반복적으로 일어나는 것을 알 수 있었고, 이 결과를 이용하여 혼합층의 성장을 제어할 수 있다.

• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.27-35
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• 2015

General education is changed by accepting the change in education environment to digital generation, emphasis about student-centered education, and change of teacher's role. E-learning has taken center stage as an effective learning environment but the problems are drawn for the absence of interaction that is important in learning. In this study, on the basis of questionnaire results about learning using website, we operated blended-learning where students come and go in cyberspace and physical space to set up the lesson environment for emphasizing interaction. We selected a control group (N=40) and an experimental group (N=40) from second grade students in a middle school for this research. General instructor-led lessons were implemented in the control group and blended-learning lessons to emphasize interaction between teacher and students were implemented in the experimental group. The experiments were applied to eight class-hours in 'characteristics of matter' unit. We implemented Test of Science Related Attitude (TOSRA) to the students before and after the lessons and administered questionnaire for checking attitude changes and perception in students. The results of the test show that the experimental group students were more encouraged and became more confident and curious about scientific learning than the control group students. The analysis of the interview and results of TOSRA show that blended-learning provided guidance and feedback by the teacher to the experimental group students more than the control group students. Blended-learning is suggested as a learning-method that is helpful in improving scientific attitude in students because it enables them to express their experiences without limit of time-space and promote interaction between teacher and students.