• 제목/요약/키워드: Reaction

검색결과 33,601건 처리시간 0.048초

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

  • 윤철호
    • 대한한의학회지
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    • 제30권5호
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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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The Reaction Probability and the Reaction Cross-section of N + O2→ NO + O Reaction Computed by the 6th-order Explicit Symplectic Algorithm

  • He, Jianfeng;Li, Jing
    • Bulletin of the Korean Chemical Society
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    • 제27권12호
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    • pp.1976-1980
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    • 2006
  • We have calculated the reaction probability and the reaction cross-section of the $N(^4S)+O_2(X^3\sum_{g}^{-})\;\rightarrow\;NO(X^2\Pi)+O(^3P)$ reaction by the quasiclassical trajectory method with the 6th-order explicit symplectic algorithm, based on a new ground potential energy surface. The advantage of the 6th-order explicit symplectic algorithm, conserving both the total energy and the total angular momentum of the reaction system during the numerical integration of canonical equations, has firstly analyzed in this work, which make the calculation of the reaction probability more reliable. The variation of the reaction probability with the impact parameter and the influence of the relative translational energy on the reaction cross-section of the reaction have been discussed in detail. And the fact is found by the comparison that the reaction probability and the reaction cross-section of the reaction estimated in this work are more reasonable than the theoretical ones determined by Gilibert et al.

산화제를 이용한 니트로벤젠 함유 폐수 처리 (Treatment of nitrobenzene-cotaminated Wastewater using Oxidation Reaction)

  • 신진환;손종렬
    • 환경위생공학
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    • 제17권1호
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    • pp.69-74
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    • 2002
  • This study explored for treatment processes by investigating the treatment efficiency and reaction mechanism through oxidation reaction using UV and $O_3$ as oxidant in compensate the wastewater containing nitrobenzene that is non biodegradable organic. Also by modeling these reactions, we try to step explanation of optimum reaction rate and reaction mechanism as the development of the computer program predictable the reaction rate by modeling the reaction. By using this model, after kinetic constant for each reaction from an experimental data is made an optimization and for hardly contribute to reaction rate in reaction kinetic equation is made an ignorance and suppose the simplified reaction mechanism, examined the propriety of computer simulation model and simplified reaction mechanism by comparing and inspecting the reaction kinetic constant and masstransfer coefficient. An investigation results for destructional treatment of nitrobenzene in the wastewater as non-biddegradable organic using UV, $O_3{\;}O_2{\;}H_2O_2-UV$ as oxidant.

전산모델링을 통한 투과증발-촉진 에스테르화 반응에 대한 연구 (A Parametric Study of Pervaporation-facilitated Esterification)

  • 염충균;최승학;박유인;장성순
    • 멤브레인
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    • 제17권2호
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    • pp.146-160
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    • 2007
  • 본 연구에서는 불과 함께 에스테르화 반응물 및 생성물 일부가 친수성 막을 투과하는 비완전 분리를 고려한 투과증발-촉진 에스테르화 반응모델을 확립하였으며, 이 모사모델에 막 분리 효율 및 물 제거능력을 설명하는 항들을 포함시킴으로써 막 투과분리가 에스테르화 반응에 어떻게 영향을 끼치는가를 공정모사를 통해서 체계적으로 살펴보았다. 모사결과 막을 통한 비완전 분리 즉, 분리막을 통한 반응물의 투과는 역반응을 유발시켜 전체 반응을 지연시키며 그 결과 반응 전 환율은 투과증발 공정을 사용하지 않은 반응보다는 높으나 물에 대한 완전한 투과선택도를 갖는 투과증발 공정을 사용하는 반응시스템보다는 낮음을 알 수가 있었다. 반응 시스템 내에서 장착된 막을 통한 투과로 인한 반응부피의 변화가 반응 속도에 끼치는 영향을 살펴보았는데 반응 초기에는 반응물 농축효과가 지배적이어서 반응을 촉진시키며, 반응이 진행되어 생성물이 형성됨에 따라 생성물 농축효과가 점점 중요해지고 이 효과가 반응의 속도를 감소시킴을 알 수가 있었다. 에스테르화 반응공정 중에 투과증발공정을 적용하는 시점에 따라 반응속도, 반응 전화율이 달라짐을 공정모사를 통해 관찰하였다. 반응 모델 식으로부터 분리막의 성능과 반응 인자들 간의 상관관계는 확립하고 이 상관관계를 주어진 막 분리능력 하에서 반응 인자 조건 설정, 혹은 주어진 반응조건 하에서 막 분리능력을 설계하는 도구로 사용할 수 있다.

Nonlinear Entropy Production in a Reversible Oregonator Model

  • Basavaraja, C.;Pierson, R.;Park, Seung-Hyun;Jeon, Eun-Ji;Huh, Do-Sung
    • Bulletin of the Korean Chemical Society
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    • 제29권5호
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    • pp.1051-1054
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    • 2008
  • The entropy production in a non-equilibrium state based on the reversible Oregonator model of the Belousov-Zhabotinskii (BZ) reaction system has been studied. The reaction affinity and the reaction rate for the individual steps have been calculated by varying the concentrations of key variables in the system. The result shows a linear relationship between the reaction affinity and the reaction rate in the given concentration range. However, the overall entropy calculated on the basic assumption that the entropy in a reaction system corresponds to the summation of a product of reaction affinity and reaction rate of individual steps shows a nonlinearity of the reaction system. The results well agrees with the fact that the entropy production is not linear or complicated function in a non-linear reaction system.

가열온도에 따른 수삼의 갈변반응 특성 (Browning Reaction of Fresh Ginseng (Panax ginseng C.A. Meyer) as Affected by Heating Temperature)

  • 이종원;이성계
    • Journal of Ginseng Research
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    • 제19권3호
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    • pp.249-253
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    • 1995
  • In the browning reaction of Korean ginseng, it appears that enzymatic and non-enzymatic browning reaction occurred in the initial stage of heating fresh ginseng at low temperature, and then non-enzymatic browning reaction followed in the drying period after heating. Activation energy of the browning reaction for red ginseng was about 9.0 kcal/mol. Browning reaction of red ginseng was accede- rated with an increase in steaming time, and a great extent of browning reaction occurred between 60-90 min of steaming at 10$0^{\circ}C$. Browning pigments of red ginseng were mostly water soluble subset.

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산촉매에 의한 대두유의 전이에스테르화 반응 특성 (Characteristics of Transesterification Reaction of Soy Bean Oil by Acid Catalysts)

  • 신용섭
    • 한국환경과학회지
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    • 제18권2호
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    • pp.231-238
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    • 2009
  • Characteristics of the transesterification reaction between triglycerides in soy bean oil and methanol were investigated in the presence of acid catalysts. such as sulfuric acid and PTS (p-toluene sulfonic acid). Concentrations of diglyceride and monoglyceride which were intermediates in the reaction mixtures, were far below 10% of triglyceride under any reaction conditions. Thus, conversion of the reaction could be determined from the concentration of triglyceride. Dried PTS had more superior catalytic power than sulfuric acid for transesterification reaction between soy bean oil and methanol. When transesterification reaction of soy bean oil was catalyzed by 1 wt% of PTS at methanol stoichiometric mole ratio of 2 and $65^{\circ}C$, final conversion reached 95% within 48 hours. If FAME (fatty acid methyl ester) was added into reaction mixture of soy bean oil, methanol and PTS catalyst, it converted reaction mixture into homogeneous phase, and substantially increased reaction rate. When reaction mixture was freely boiling which had equal volumetric amount of FAME to soy bean oil, methanol stoichiometric mole ratio of 2 and 1 wt% of PTS, final conversion achieved value of 94% and temperature approached to $110^{\circ}C$ within 2 hours.

탄화규소 휘스커의 합성(I) : 반응기구의 율속반응 (Synthesis of Silicon Carbide Whiskers (I) : Reaction Mechanism and Rate-Controlling Reaction)

  • 최헌진;이준근
    • 한국세라믹학회지
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    • 제35권12호
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    • pp.1329-1336
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    • 1998
  • A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

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Browning Reaction을 이용한 Meat Flavor Extract의 개발 (Manufacturing of Meat Flavor Extract used for Browning Reaction)

  • 김덕숙;김종승
    • 한국식품영양학회지
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    • 제17권3호
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    • pp.313-321
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    • 2004
  • Maillard reaction을 이용하여 제조한 여러 종류의 reaction meat flavor로부터 함유황 이원자고리 화합물을 분리, 농축한 다음 GC와 GC-MSD를 이용하연 함유황 이원자고리 화합물의 profile을 얻어 성분의 확인 및 정량분석을 시도하여 다음과 같은 결론을 얻었다. 1. Reaction meat flavor의 함유황 이원자고리 화합물의 profile을 조사한 결과 7종의 thiozole과 11종의 thiophene을 동정 할 수 있었으며, thiophene, thinzolidine, 4-methyl-5-thiazole ethanol이 주요 생성 화합물이었다. 2. 함유황 이원자고리 화합물의 경우 반응조건(온도, 시간)의 변화에 따라 생성성분의 종류에는 거의 차이가 없었지만 그 양에 있어서는 상당한 차이가 나타났고, 반응온도가 높을수록, 반응시간이 길수록 구조가 복잡한 함유황 이원자고리 화합물과 caramellike note를 갖는 함산소 이원자고리 화합물이 보다 많이 생성되었으며, 반대로 반응온도가 낮고 반응시간이 짧을수록 함유황이 원자고리 화합물의 생성이 비교적 적었다. 3. 수분함량 50%, 반응온도 10$0^{\circ}C$, 반응시간 2시간의 반응조건에서 thiophene과 thiazole 같은 비교적 구조가 단순한 함유황 이원자고리 화합물의 생성율이 가장 높았으며, reaction meat flavor의 발현을 위하여는 10$0^{\circ}C$ 이내의 온도에서 2시간을 넘기지 않고 반응시키는 것이 좋았다. 4. 수분함량이 낮으면 반응온도 및 시간을 낮고 짧게, 수분함량이 높을수록반응온도 및 시간은 높고 길게 반응시키는 등 수분함량은 반응온도 및 시간과 밀접한 관계에 있으므로 수분함량에 따라 반응조건을 변화시킴으로써 일정한 flavor profile을 계속하여 얻을 수 있었다. 이와 같이 원료를 단순화하여 reaction meat flavor를 제조한 다음 함유황 이원자고리 화합물을 추출, 분리, 농축하여 분석함으로써 향료산업 및 조미식품산업에서 reaction meat flavor의 생산에 필요한 하나의 방향을 제시할 수 있었다.

알칼리 자극제(刺戟劑)에 의해 고로(讀爐) 수쇄(水碎) 슬래그의 주위(周圍)에 형성(形成)된 Reaction Rim의 특성(特性) (Properties of Reaction Rim on Blast Furnace Slag Grain with Alkali Activator according to Hydration Reaction)

  • 이승헌;문영범
    • 자원리싸이클링
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    • 제18권3호
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    • pp.42-48
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    • 2009
  • 고로 수쇄 슬래그에 알칼리 자극제(NaOH+$Na_2O.SiO_2$)를 첨가한 계는 보통 포틀랜드 시멘트의 수화반응과 다르게, 수화반응 초기에 높은 농도의 $OH^-,\;[SiO_4]^{4-}$ 이온이 존재하게 되므로, 유도기가 없이 수화반응이 빠르게 진행되며, 슬래그 입자 주위에 수화물에 의한 reaction rim을 형성한다 반응기간 1일부터 고로 수쇄 슬래그 입자 주위에 $0.6{\mu}m$의 reaction rim이 형성되었고, 반응기간이 증가함에 따라 reaction rim의 두께는 증가하여 28일에 $1{\mu}m$으로 성장하였으며, 미반응 고로 수쇄 슬래그 입자는 각진 형태에서 구형의 형태로 변화되었다. 슬래그 입자의 내부로부터 reaction rim으로 갈수록 Ca/Si의 몰비는 감소하는 경향을 나타냈었다. 그리고 반응기간이 경과할수록 슬래그 입자 내부와 reaction rim간의 Ca/Si 몰비 차이는 작아졌으며, 생성된 수화물은 저결정성의 Ca/Si 몰비가 1.5 미만인 CSH(I)이었다.