• 한국미생물·생명공학회지
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• 제28권1호
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• pp.26-32
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• 2000

Electrostatic forces contribute to the high degree of enzyme transition state complementarity in enzyme catalyzed reaction and such forces are modified by the solvent through its dielectric constant and polar properties. The contributions of electrostatic interaction to the formation of ES complex and the stabilization of transition state of the trypsin catalyzed reaction were probed by kinetic studied with high pressure and solvent dielectric constant. A good correlation has been observed between the increase of catalytic efficiency of trypsin and the decrease of solvent dielectric constant. Activation volume linearly decreased as the dielectric constant of solvent decreased, which means the increase in the reaction rae. Moreover, the decrease of activation volume by lowering the solvent dielectric constant implies a solvent penetration of the active with and a reduction of electrostatic energy for the formation of dipole of the active site oxyanion hole. When the 야electric constant of the solvents was lowered to 4.7 unit, the loss of activation energy and that of free energy of activation were 2.262 KJ/mol and 3.169 KJ/mol, respectively. The results of this study indicate that the high pressure kinetics combined with solvent effects can provide unique information on enzyme reaction mechanisms, and the controlling the solvent dielectric constant can stabilize the transition state of the trypsin-catalyzed reaction.

• 한국산업융합학회 논문집
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• 제15권3호
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• pp.71-77
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• 2012

This study gives the optimal reaction conditions, reaction mechanisms, reaction rates leaded from the oxidation of phenol by electron beam accelerator and ozone used for recent water treatment. It gives the new possibility of water treatment process to effectively manage industrial sewage containing toxic organic compounds and biological refractory materials. The high decomposition of phenol was observed at the low dose rate, but at this low dose rate, the reaction time was lengthened. So we must find out the optimal dose rate to promote high oxidation of reactants. The reason why the TOC value of aqueous solution wasn't decreased at the low dose was that there were a lot of low molecular organic acids as an intermediates such as formic acid or glyoxalic acid. In order to use both electron beam accelerator and biological treatment for high concentration refractory organic compounds, biological treatment is needed when low molecular organic compounds exist abundantly in sewage. In this experiment, the condition of making a lot of organic acids is from 5 kGy into 20 kGy dose. Decomposition rate of phenol by electron beam accelerator was first order reaction up to 300ppm phenol solution on the basic of TOC value and also showed first order reaction by using both air and ozone as an oxidants.

• 한국실내디자인학회논문집
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• 제38호
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• pp.65-74
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• 2003

The purpose of this study Is to find out the design guideline for women's hospital focusing on the patient needs. The results of research are as follows: 1) As a basic frame of evaluation model, the quality of service of medical facilities and patients' reaction to the physical environment are fixed as a variable called' satisfaction degree'. This study analyzes the influence on space efficiency evaluation according to the difference of types through basic model (Model I-1,2) as verification model to identify the difference between satisfaction degree of outpatients and that of inpatients. 2) The difference of satisfaction degree about the hospital facilities by space evaluation matrix is according to the types of inpatients and to space importance. 3) The control of importance degree about the interior facilities of the hospital according to the specific character of the hospital is necessary. Maintenance of the status quo, or reduction, or expansion is needed according to the satisfaction degree corresponding to the importance degree. Finally, the model is used to for the planning & design for the future women's hospital.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.75-81
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• 2003

In this paper, the study of effects of flow variables on flame structure and NOx emission concentration was performed in co-axial laminar partially premixed methane/air flames. the objectives are to reveal its effect as parameters were varied and to understand the correlation between flame structure and NOx emission characteristics in the reaction zone. equivalence ratio(${\Phi}$), fuel split degree(${\sigma}$), and mixing distance(x/D) were defined as a premixing degree and varied within $1.36{\sim}3.17$(equivalence ratio), $50{\sim}100$(fuel split degree), and $5{\sim}20$(mixing distance). the image of $OH{\ast}$ and $CH{\ast}$, and NOx concentration were obtained with an ICCD camera and a NOx analyzer. additionally the maximum intensity location of $OH{\ast}$ chemiluminescence and $CH{\ast}$ chemiluminescence were measured to compare each flame structures. In conclusion flame structure and NOx emission characteristics were changed from diffused to premixed flame when mixing degree was on the increase. the main effect on flame structure and NOx production was at first equivalence ratio(${\Phi}$), and next fuel split degree(${\sigma}$), and finally mixing distance(x/D).

• 폴리머
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• 제25권1호
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• pp.25-32
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• 2001

${\circ}C$ 범위에서 아연과 망간촉매를 사용하여 에스테르 교환반응시켜 반응속도를 살펴보았다. 반응은 반회분식 반응기에서 비등온 조건으로 진행되었고 반응온도와 메탄올 유출량으로 반응성을 평가하였다. 반응모델로서는 관능기 모델과 분자종 모델을 적용하여 상호 비교하였다. 아연촉매를 사용할 경우 DMN과 EG의 반응속도는 methyl hydroxyethyl naphthalate(MHEN)와 EG의 반응속도에 비해 1.4배정도 였으나 망간촉매를 사용할 경우 4.3배정도로 촉매 종류에 따라 반응성이 크게 차이가 있음을 알 수 있었다. 아연촉매의 경우 DMN 및 MHEN과 EG의 반응에 대한 촉매농도의 반응차수는 1보다 작았으나, 망간촉매의 경우 오히려 1보다 컸다. 활성화에너지는 DMN과 MHEN의 분자종 차이에 관계없이 아연과 망간촉매의 경우 각각 25000, 28750 cal/mol이었다. 두 가지 반응모델을 비교하여 본 결과 분자종 모델이 반응현상을 잘 표현함을 알 수 있었다.

• Elastomers and Composites
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• 제48권1호
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• pp.39-45
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• 2013

Haake Rheocorder로 각종 과산화물 개시제를 사용하여 ethylene-propylene-diene terpolymer (EPDM)에 단량체 citraconic acid (CCA)을 용융 그라프트 중합을 하여 그라프트 중합물 CCA-g-EPDM을 얻었으며, 이때 효율적인 그라프트 정도와 우수한 성능을 지닌 그라프트 중합물을 얻기 위해서 최적의 반응조건과 최적의 단량체/개시제 농도를 찾는 것은 매우 중요하다. 따라서 본 연구에서는 반응조건과 단량체 및 개시제 함량이 CCA-g-EPDM의 그라프트 정도, 그라프트 효율, 가교정도 (겔화도), 용융흐름지수(MI) 및 기계적 물성 등에 미치는 영향에 초점을 맞추었다. 그라프트 정도와 가교도가 증가함에 따라서 인장강도는 상당히 증가한 반면, 파괴신도 및 MI는 감소하였다. 개시제 중에서 2,5-dimethyl-2,5-di(tert-butyl peroxy)-hexane (T-101)가 가장 우수한 그라프트 정도 (2.31%)를 나타내었으며, CCA와 T-101의 함량이 증가함에 따라 그라프트 정도가 크게 증가하였다. 그리고 그라프트 정도는 반응(혼합)온도 및 반응시간이 증가함에 따라 역시 증가하다가 어느 온도/시간 이상에서는 안정화 혹은 약간 감소하는 경향을 나타내었다. 이러한 영향으로 결과로부터 최적의 단량체/개시제 농도는 5/0.05 wt%이었으며, 최적의 반응온도/시간은 $180^{\circ}C$/15분인 것을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제40권2호
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• pp.110-122
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• 2012

This study investigated the effects of layered clay on the thermal curing behavior and tensile properties of resole phenol-formaldehyde (PF) resin/clay/cellulose nanocomposites. The thermal curing behavior of the nanocomposite was characterized using conventional differential scanning calorimetry (DSC) and temperature modulated (TMDSC). The addition of clay was found to accelerate resin curing, as measured by peak temperature ($T_p$) and heat of reaction (${\Delta}H$) of the nanocomposite’ curing reaction increasing clay addition decreased $T_p$ with a minimum at 3~5% clay. However, the reversing heat flow and heat capacity showed that the clay addition up to 3% delayed the vitrification process of the resole PF resin in the nanocomposite, indicating an inhibition effect of the clay on curing in the later stages of the reaction. Three different methods were employed to determineactivation energies for the curing reaction of the nanocomposite. Both the Ozawa and Kissinger methods showed the lowest activation energy (E) at 3% clay content. Using the isoconversional method, the activation energy ($E_{\alpha}$) as a function of the degree of conversion was measured and showed that as the degree of cure increased, the $E_{\alpha}$ showed a gradual decrease, and gave the lowest value at 3% nanoclay. The addition of clay improved the tensile strengths of the nanocomposites, although a slight decrease in the elongation at break was observed as the clay content increased. These results demonstrated that the addition of clay to resole PF resins accelerate the curing behavior of the nanocomposites with an optimum level of 3% clay based on the balance between the cure kinetics and tensile properties.

• 대한간호학회지
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• 제23권4호
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• pp.555-568
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• 1993

The purposed of this study was to identify compliance with sick role behavoir and support by families of patients with pulmonary tuberculosis and to identify factors affecting these variables md factors that increase compiance with sick role behavoior This study was a survey design done in K. general hospital from 1992. 7 1 to 1992. 7. 20. The data were collected through personal interviews with 70 subjects who had pulmonary tuberculosis. A questionnaire was used to collect the data. 1. Demographic characteristics of the subjects The factor causing the tuberculosis for 28.6% of the subjects was that they lived with another family member who had pulmonary tuberculosis, 11.4％ of the subjects had a family member who died of tuberculosis, 24.3% of the subjects had experienced an adverse reaction to medication. Gastroenteric disorders(28.6%) had the highest rate for this kind of adverse reaction to medication. 2. Support by families for patients with pulmonary tuberculosis The items which showed high support for compliance were taking medicine regularly(80.0% ) eat-ing a balanced diet(80.0%), loving them(84.3%), taking care of them(82.8%), getting the support from people for being sick(81.1%) The items which showed low support for compliance were meeting relatives or clergymen(20%), talking with the people suffering from pulmenary tuberculosis to relieve frustrated because they were not recovering. 3. General characteristics and family support The degree of family support showed that 75 was highest score and 30, the lowest score with 55.5(74. 1%)the average score. The degree of family support appeared similar in cases where the person was married and where the person did not have a family member with pulmonary tuberculosis(P〈.01) 4. The degree of compliance with sick role behavior by patients with pulmonary tuberculosis The degree of compliance with sick role behavior showed that 100 was the highest scoure47, the low-est score and 76.4, the average score out of a Possible score of 100. 5. Correlation between compliance with sick role behavior and family support The compliance with sick role behavior and family support showed a positive correlation(r=.2094 p〈.5) So for patients with pulmonary tuberculosis. compliance with sick role behavior is related to the sup-port given by their families.

• Food Science and Biotechnology
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• 제17권4호
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• pp.839-841
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• 2008

The mutagenicity after heating of different sugars (glucose, fructose, galactose, and tagatose) on the non-enzymatic browning reaction in different sugars and glycine model system was investigated. The model system containing 0.2 M glycine and 0.2 M of different sugars in 10 mL water was heated at $150{\pm}5^{\circ}C$ for 30 min. After heating, degree of non-browning reaction intensity and mutagenicity using Salmonella typhimurium TA 98 were examined. Heated glycine model systems containing different sugars increased their mutgenicity ranged from 30 to 372 revertant colonies. After heating for 40 min, mutagenicity was achieved with glycine model systems containing 4 different sugars with by 145, 356, 206, and 369 revertants per plate, respectively. The glycine model systems containing fructose or tagatose were significantly (p<0.05) higher mutagenic activity than glycine model systems containing glucose or galactose after 40 min of heating. The linear regression between Maillard reaction intensity and mutagenic activities (slope=32.38, $R^2=0.93$) indicates that mutagenicity could be fully ascribed to Maillard reaction products.

• Preventive Nutrition and Food Science
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• 제3권4호
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• pp.320-323
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• 1998

Lysozyme was covalentyl conjugated with galactomannan through a amino-carbonyl reaction between the lysine $\varepsilon$-amino groups of lysozyme and the reducing ends of galactomannan at a relative humidity of 79% and 6$0^{\circ}C$. The resulting lysozyme-galactomannan conjugate (LGC) was investigated for its antibacterial activity against Escherichia coli. Lysozyme alone did not exhibit antibacterial activity against E. coli. in contrast , significant bactericidal effect was observed for LGC, depending on the reaction temperature. The degree of conjugation between lysozyme and galactomannan was dependent on the incubation time, which affected the antibacterial efficiency against E. coli. This study demonstrated that the amino-carbonyl reaction between lysozyme and galactomannan could be a potential tool to modify lysozyme toward broadening its antibacterial spectrum to Gram-negative bacteria.