• Title/Summary/Keyword: Side Reaction

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Two different reaction mechanisms of cinnamate side groups attached to the various polymer backbones

  • Hah, Hyun-Dae;Sung, Shi-Joon;Cho, Ki-Yun;Jeong, Yong-Cheol;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.772-775
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    • 2006
  • Cinnamate polymers are well known photoreactive polymers due to [2+2] cycloaddition reaction of cinnamate side group. In this work, we have found that the cinnamate side groups could be also reacted by thermal energy, and this reaction is presumed to attribute to the radical reaction of carbon double bond in the cinnamate groups. Contrary to the photocycloaddition reaction of the cinnamate side groups, the thermal reaction of cinnamate side group was closely related to the flexibility of polymer backbone. The difference of the mechanism between the photocycloaddition reaction and thermal crosslinking reaction was confirmed by $^1H-NMR$$ and $^{13}C-NMR$ analysis of the model compound.

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Effect of Plasticization of Poly(Vinyl Cinnamate) on Liquid Crystal Orientation Stability

  • Hah, Hyun-Dae;Sung, Shi-Joon;Cho, Ki-Yun;Kim, Won-Sun;Jeong, Yong-Cheol;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1518-1522
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    • 2005
  • A cinnamate group is a well-known compound group used in the dimerization reaction by ultraviolet irradiation, and cinnamate polymers are studied as photoalignment materials. In this study, the radical reaction of cinnamate side groups attached to a flexible polymer backbone is considered feasible using thermal energy. To induce the thermal reaction of cinnamate side groups, we modified the flexibility of poly(vinyl cinnamate) by introducing a plasticizer into the polymers and investigated the thermal reaction behavior of cinnamate side groups. The plasticization of poly(vinyl cinnamate) makes the induction of the thermal reaction of cinnamate side groups easier than that of unmodified poly(vinyl cinnamate). The thermal reaction of cinnamate side groups is closely related to the enhancement of the thermal stability of the liquid crystal orientation of polymer films with polarized UV irradiation.

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Anatomical Studies on the Differentiation of Reaction Tissues in Ginkgo biloba L. Seedling (은행나무 유식물에 있어서 반응조직의 분화에 대한 해부학적 연구)

  • 강경덕
    • Journal of Plant Biology
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    • v.33 no.4
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    • pp.285-292
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    • 1990
  • In order to elucidate the formation of reaction tissues during the transition from primary to secondary growth, the developmental anatomy was conducted in the first internode of Ginkgo biloba seedling in horizontal position. The righting of the horizontal first internode took place at the middle portion and gradually proceeded to the base during the primary growth. Reaction tissues were formed corresponding to the righting movement in the horizontal first internode. During the transition from primary to secondary growth, compression wood was gradually developed on the lower side only. The anatomical features of compression wood also extended longitudinally to the lower side of the vertical portion where it coincided with the lower side of the horizontal first internode occurs acropetally from basal to apical portion. Eventually, some of the anatomical features of compression wood occurred at the primary growth. And the typical compression wood is gradually established during the secondary growth. On the other hand, the lower side tracheid and ray were longer and higher than those of the upper side in the horizontal first internode. However, difference in the width of ray was not observed between the lower and upper sides.

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The Control of Side Reactions in Bunsen Reaction Section of Sulfur-Iodine Hydrogen Production Process (황-요오드 수소 생산 공정의 분젠 반응 부분에서 부반응 제어)

  • Lee, Kwang-Jin;Hong, Dong-Woo;Kim, Young-Ho;Park, Chu-Sik;Bae, Ki-Kwang
    • Transactions of the Korean hydrogen and new energy society
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    • v.19 no.6
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    • pp.490-497
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    • 2008
  • For continuous operation of the sulfur-iodine(SI) thermochemical cycle, which is expected practical method for massive hydrogen production, suggesting operation conditions at steady state is very important. Especially, in the Bunsen reaction section, the Bunsen reaction as well as side reactions is occurring simultaneously. Therefore, we studied on the relation between the variation of compositions in product solution and side reactions. The experiments for Bunsen reaction were carried out in the temperature range, from 268 to 353 K, and in the $I_2/H_2O$ molar ratio of $0.094{\sim}0.297$ under a continuous flow of $SO_2$ gas. As the result, sulfur formed predominantly with increasing temperature and decreasing $I_2/H_2O$ molar ratios. The molar ratios of $H_2O/H_2SO_4$ and $HI/H_2SO_4$ in global system were decreased as the more side reaction occurred. A side reactions did not appear at $I_2/H_2O$ molar ratios, saturated with $I_2$, irrespective of the temperature change. We concluded that it caused by the increasing stability of an $I_{2x}H^+$ complex and a steric hindrance with increasing $I_2/HI$ molar ratios.

A Study on Heat Storage System Using Calcined Dolomite - Numerical Analysis of Heat Transfer in Calcined Dolomite Dehydration Packed Bed - (소성Dolomite 수화물계의 축열시스템에 관한 연구 - 소성Dolomite 탈수반응층의 전열해석 -)

  • Park, Young-Hae;Kim, Jong-Shik
    • Journal of the Korean Solar Energy Society
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    • v.23 no.1
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    • pp.29-38
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    • 2003
  • To develope chemical heat pump using available energy sources, solar heat and other kinds of waste thermal energy, we have studied the material and heat transfer rate in the cylindrical bed reactor packed with Calcined Dolomite. Our results from the studies are as follows ; 1 The time needed to complete dehydration reaction at the wall side of the cylindrical reactor(r/rL=0.5) was shorter than that of the center(r/rL=0.0) as much as 12%. 2. Two dimensional (radial and circumferential) partial differential equations, concerning heat and mass transfer rate in the packed bed of calcined Dolomite, are solved numerically to describe the characteristics of the reaction in the cylindrical reactor. The solution reads rate of reaction in the packed bed reactor depends on the temperature and concentration of reactants. These results read the supplied heat transfers from the wall side of the cylinder to the center, dehydration reaction begins at the inner side of the wall of the cylindrical reactor and the dehydration reaction proceeds from the wall side to center of cylinder.

A Study of Reports about Dizziness Reaction - Focus on the China Academic Journal - (명현(瞑眩) 반응에 대한 보고 연구 - China Academic Journal을 중심으로 -)

  • Yoon, Cheol-Ho
    • The Journal of Korean Medicine
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    • v.30 no.5
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    • pp.1-15
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    • 2009
  • Objectives: I carried out this study for research on dizziness (瞑眩) reaction. Methods: I found 14 papers about dizziness reaction from 1994 to 2009 in China Academic Journal (CAJ) website, and synthesized these reports. Results: Dizziness reaction, presupposing that the diagnosis and treatments are correct, is a peculiar reaction which occurs with severe and various symptoms temporarily diverging from regular course. As dizziness reaction disappears, the symptoms of the disease are improved. Though it mostly occurs rapidly and disappears in a short time, it can occur after a long treatment or occur gradually in chronic diseases. As a general rule, the faster dizziness reaction occurs, the more severe the reaction. The faster dizziness reaction disappears, the quicker the recovery from illness. Upon catching a disease, healthy qi(正氣) and the pathogen (邪氣) fight each other. Just at that moment, if the medicine or acupuncture treatment hits the mark of the pathogen (邪氣), healthy qi(正氣) attacks the origin of the disease in full force. Thus, all symptoms disappear at a time and various reactions occur which we can't accurately determine. So, we can call it 'Right action', 'Improving reaction' or 'Adjusting reaction'. Conclusions: It is difficult for us to predict whether a dizziness reaction will occur. Thus, we don't have to seek dizziness reaction blindly, and must distinguish dizziness reaction from side effects or toxic effects. So, we must pay more close attentions to symptom changes.

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Stereospecific Synthesis of 2,4-Dienoci Acid Derivatives from Vinylmercuric Chlorides and Acrylic Acid Derivatives by Palladium(II) Salt

  • Kim Jin Il;Lee Jong Tae
    • Bulletin of the Korean Chemical Society
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    • v.7 no.6
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    • pp.472-477
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    • 1986
  • The reaction of (E)- or (Z)-1-alkenylmercuric chlorides with acrylic acid derivatives in the presence of 10 mol% of lithium trichloropalladate ($LiPdCl_3$) and an equimolar amount of cupric chloride, as a reoxidant for the palladium, in acetonitrile at room temperature gave the corresponding (E,E)- or (E,Z)-2,4-dienoic acid derivatives stereospecifically in moderate to good yields. The reaction of (E)- or (Z)-3-chloromercuripropenoic acid with olefins under the reaction condintion described above similarly gave good yields of (E,E)- or (Z,E)-2,4-dienoic acids stereospecifically. A side reaction, the homocoupling of alkenylmercuric chlorides, could be minimized by employing the condition described above. However, in the reaction of 3-chloromercuripropenoic acid with olefins under the present condition, the homocoupled side reaction product was not produced.

Investigation on Performance Analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor (소듐냉각고속로 원형로 소듐-물 반응 압력완화계통 성능 해석 연구)

  • Park, Sun Hee;Han, Ji-Woong
    • Korean Chemical Engineering Research
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    • v.57 no.1
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    • pp.28-41
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    • 2019
  • We carried out performance analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor. We analyzed transient-dynamic behavior of fluids inside the steam generator to vent into a sodium dump tank or a water dump tank when tubes in the steam generator were broken to cause a large-water-leak accident. Accordingly, we preliminarily evaluated design requirements of our system. Our results showed that sodium in the shell side of the steam generator and in Intermediate Heat Transport System was completely vented within 50 s and feed water in the tube side of the steam generator was completely vented within 2.5 s. It was analyzed that pressure of the tube side of the steam generator was higher than pressure of the shell side of the steam generator, which showed that sodium in the shell side did not flow into the tube side. Our results are expected to be used as basis information to performance analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor.

Structural Changes of the Spinach Photosystem II Reaction Center After Inactivation by Heat Treatment

  • Jang, Won-Cheoul;Tae, Gun-Sik
    • BMB Reports
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    • v.29 no.1
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    • pp.58-62
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    • 1996
  • The structural changes in the electron donor side of the PSII reaction center have been monitored since heat treatment ($45^{\circ}C$ for 5 min) of thylakoids is known to decrease the oxygen evolving activity. In heat-treated spinach chloroplast thylakoids, the inhibitory effect of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the electron transport activity of the PSII reaction center from diphenyl carbazide to dichlorophenolindophenol became reduced approximately 3.8 times and [$^{14}C$]-labeled DCMU binding on the D1 polypeptide decreased to 25~30% that of intact thylakoid membranes, implying that the conformational changes of the DCMU binding pocket, residing on the D1 polypeptide, occur by heat treatment. The accessibility of trypsin to the $NH_2$-terminus of the cytochrome b-559 ${\alpha}$-subunit, assayed with Western blot using an antibody generated against the synthetic peptide (Arg-68 to Arg-80) of the COOH-terminal domain, was also increased, indicating that heat-treatment caused changes in the structural environments near the stromal side of the cytochrome b-559 ${\alpha}$-subunit, allowing trypsin more easily to cleave the $NH_2$-terminal domain. Therefore, the structural changes in the electron donor side of the PSII reaction center complexes could be one of the reasons why the oxygen evolving activity of the heat-treated thylakoid membranes decreased.

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A Study on Reaction Stability Between Nickel and Side-wall Materials With Silicidation Temperature (니켈실리사이드 제조온도에 따른 측벽물질과의 반응안정성 연구)

  • An, Yeong-Suk;Song, Oh-Sung
    • Korean Journal of Materials Research
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    • v.11 no.2
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    • pp.71-75
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    • 2001
  • The reaction stability of nickel with side-wall materials of SiO$_2$ and Si$_3$N$_4$ on p-type 4"(100) Si substrate were investigated. Ni on 1300 $\AA$ thick SiO$_2$ and 500 $\AA$ - thick Si$_3$N$_4$ were deposited. Then the samples were annealed at 400, 500, 750 and 100$0^{\circ}C$ for 30min, and the residual Ni layer was removed by a wet process. The interface reaction stability was probed by AES depth Profiling. No reaction was observed at the Ni/SiO$_2$ and Ni/Si$_3$N$_4$, interfaces at 400 and 50$0^{\circ}C$. At 75$0^{\circ}C$, no reaction occurred at Ni/SiO$_2$ interface, while $NiO_x$ and Si$_3$N$_4$ interdiffused at Ni/Si$_3$N$_4$ interface. At 100$0^{\circ}C$, Ni layers on SiO$_2$ and Si$_3$N$_4$ oxidized into $NiO_x$ and then $NiO_x$ interacted with side-wall materials. Once $NiO_x$ was formed, it was not removed in wet etching process and easily diffused into sidewall materials, which could lead to bridge effect of gate-source/drain.

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