• 제목/요약/키워드: Quasi-state

검색결과 502건 처리시간 0.029초

Kinetic Study of Thermolysin-Catalyzed Synthesis of N-(Benzyloxycarbonyl)-L-Phenylalanyl-L-Leucine Ethyl Ester in an Ethyl Acetate Saturated Aqueous System

  • Nam, Kwang-Ho;Lee, Chang-Kyung;Jeong, Seung-Weon;Chi, Young-Min
    • Journal of Microbiology and Biotechnology
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    • 제11권4호
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    • pp.649-655
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    • 2001
  • The kinetics of the thermolysin-catalyzed synthesis of N-(benzyloxycarbonyl)-L-phenylalanyl-L-leucine ethyl ester (Z-Phe-LeuOEt) from N-(benzyloxycarbonyl)-L-phyenylalanine (Z-Phe) and L-leucine ethyl ester (LeuOEt) in an ethyl acetate saturated aqueous system in a batch operation were studied. The kinetics for the synthesis of Z-Phe-LeuOEt were expressed using a rate equation for the rapid equilibrium random bireactant mechanism. The four kinetic constants involved in the rate equation were determined numerically by the quasi-Newton method so as to fit the calculated results with the experimental data. Within the pH and temperature range examined, the $K_{cat}$ value for the synthesis of Z-Phe-LeuOEt reached a maximum at pH 7.0 and $45^{\circ}C$, whereas the affinity between Z-Phe and thermolysin reached a maximum at pH 6.0 adn $40^{\circ}C$. The inhibitory effect of Z-Phe on the condensation reaction decreased as the pH and temperature decreased. In contrast, they affinity between LeuOEt and thermolysin remained unchanged within the pH and temperature range examined. Therefore, it was concluded that the protonation state of the carboxyl groups. of Z-Phe was more imprtant than that of the amono groups of LeuOEt for the synthesis of Z-Phe-LeuOEt in the present solvent system. The equilibrium yield at pH 6.0 and $30^{\circ}C$ was 8% higher than that at pH 7.0 and $40^{\circ}C$, although the rate was much slower. This result suggested that the affinity between the enzyme and the substrate rather than the overall rate was a more important factor affecting the equilibrium yield, when the peptide synthesis was carried out in a product-precipitation system.

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부산북항 재개발에 따른 유동장 및 해수교환 변화 모의 (Simulation of Flow field and Water exchange Change on the Redevelopment of Busan North Port)

  • 오동훈;이중우;금동호;전성환;김강민
    • 한국항해항만학회지
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    • 제30권10호
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    • pp.861-867
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    • 2006
  • 부산항(북항) 재개발사업은 노후화된 북항 일반부두를 해양관광의 중심지역 그리고 부산시민을 위한 친수공간으로 개발하기 위해 그동안 많은 연구와 노력이 진행되어 왔으며, 현재 구체적인 방안이 모색되는 실행단계로 진입하였다. 한편, 재개발로 인한 유동장 및 해수교환의 변화는 환경적인 측면에서 중요한 검토사항 중 하나이다. 본 연구에서는 북항 재개발에 따른 일반적인 자료를 수집 분석하고, 이를 바탕으로 하여 재개발에 따른 유동장의 변화와 만 내 해수교환을 수치실험으로 검토하였다. 실험결과, 조류속 변화는 북항 및 내항에서 감소가 나타나고 주수로상에서 증가가 나타나고 있다. 해수교환 변화는 15일이 지난 준 정상상태에서 재개발 전후 공히 약 77% 내외에 달하는 것으로 나타났다.

분만 중 전신마사지가 초산부의 분만진통과 분만스트레스 반응에 미치는 효과 (Effects of Full Body Massage on Labor Pain and Delivery Stress Reaction for Primipara during Labor)

  • 이군자;장춘자;조현숙
    • 여성건강간호학회지
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    • 제9권3호
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    • pp.224-234
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    • 2003
  • Purpose: This study was to test the effects of a full body massage on labor pain and delivery stress reaction for primipara during labor. Method: This study employed a quasi- experimental method(nonequivalent control group, pre-post test design). The subjects of this study were 57 primipara hospitalized at the U OB & GYN hospital in Inchon from November 1. 2001 to July 31, 2002. 28 women were assigned to the experimental group and 29 to the control group. The experimental group was given 20 minutes full body massage for each of three delivery phases. The control group was given conventional delivery care. The levels of labor pain were measured by the Visual Analogue Scale and the expression scores of the labor pain and the levels of delivery stress reaction were measured by pulse rate, respiration rate, and blood pressure, and State-Anxiety Scale. Data were analyzed using the repeated measures analysis of covariance(ANCOVA), t-test, $X^2$- test, simple ANCOVA with SPSS program. Result: There was no interaction effect between time and group(F=.370, p=.693), but significant time effects were found for subjective labor pain(F=3.840, p=.028). There was no interaction effect between time and group(F=.112, p=.894), but significant group effects were found for objective labor pain(F=12.299, p=.001). There was no interaction effect between time and group for PR(F=.172, p=.843), RR(F=.626, p=.539), SBP(F=.089, p=.915), DBP(F=.748, p=.479), but significant group effects were found for SBP(F=7.547, p=.008). The level of status anxiety of the experimental group was significantly lower than the control group(F=11.787, p=.001). Conclusion: This study showed that the full body massage has partially positive effect on labor pain and delivery stress reaction. Therefore this study suggested that the full body massage might be used clinically to help primipara during labor.

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발 반사요법 교육프로그램 제공이 간호대학생의 장 기능, 불안 및 우울에 미치는 효과 (Effects of Foot Reflexology Education Program on Bowel Function, Anxiety and Depression in Nursing Students)

  • 김영희;최의순
    • 여성건강간호학회지
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    • 제9권3호
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    • pp.277-286
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    • 2003
  • Purpose: The purpose of this study was to probe the effect of foot reflexology education program on nursing students with constipation, anxiety and depression. This study was a quasi-experimental study of pre-test and posttest design on non-equivalent control group. Method: The data of this study were collected from October 28, to December 14, 2002. The subjects consisted of 61 nursing students (experimental group: 31, control group: 30) with constipation, anxiety and depression. 31 out of them were devided into the experimental group and received foot reflexology education program that was authorized by the World Foot Reflexology Association and made to suit for the subjects by the author for 6weeks composed of 2 weeks theory and of 4 weeks practical skill on the program. The effect of the program was measured by Bowel Function Assessment Form for constipation, State Anxiety Inventory, and Beck Depression Inventory. Data were analyzed by t-test, $x^2$-test, Repeated measures ANOVA, Bonferroni multiple comparison using SAS/PC 8.12 program. Result: After all session of treatment, the score of bowel function assessment were significantly decreased in the experimental group compared to the control group. Outcomes of 6 and 7 weeks were significantly different from those of pre-experiment. After all session of treatment, anxiety states were significantly decreased in the experimental group compared to the control group. Outcomes of 7 weeks were significantly different from those of pre-experiment. After all session of treatment, depression states were significantly decreased in the experimental group compared to the control group. Outcomes of 6 and 7 weeks were significantly different from those of pre- experiment. Conclusion: The results are suggested that the foot reflexology education program might improve the bowel function, anxiety and depression for the nursing students with constipation, anxiety and depression.

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메탄화재의 이산화탄소 생성법에 의한 화재발열량 측정 (Measurement of Heat Release Rate by Carbon Dioxide Generation Method for Methane Fire)

  • 김성찬
    • 한국화재소방학회논문지
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    • 제34권2호
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    • pp.1-6
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    • 2020
  • 연소상태의 가연물에서 방출되는 에너지는 비정상적인 특성과 폭넓은 크기규모를 가지기 때문에 다른 화재물리량에 비해 측정하기 어려운 문제 중의 하나로 인식된다. 본 연구는 실험실규모의 화재 발열량계에서 이산화탄소생성법과 산소소모법에 의해 계산된 측정 발열량을 비교하여 상대오차를 분석하였다. 메탄 버너화재에 대해 산소소모계수와 CO2 질량유량의 상관관계는 6% 이내에서 우수한 선형성을 보였다. CDG법의 계산에서 CO에 의한 발열량 기여분은 CO2에 의한 기여분에 비해 7% 이내로 크지 않게 나타났다. 준정상상태의 기준 버너 발열량 대비 OC법과 CDG법의 선형성은 1% 이내를 보여 발열량 측정에 있어서 CDG법은 상호 보완할 수 있는 측정수단으로 활용될 수 있다.

노인의 관절 건강증진 프로그램 효과 (The Evaluation of a Program to Promote Healthy feints in Older Adults Residing in the Community)

  • 은영;강영실;김은심;권인수;오현숙;구미옥
    • 기본간호학회지
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    • 제12권2호
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    • pp.171-179
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    • 2005
  • Purpose: This study was conducted from March to August, 2003 to evaluate the process and outcomes of a program to promote healthy joints in older adults residing in the community. Method: A quasi experimental research design (one group pretest posttest design) was used in this study. The participants were 26 older adults (but 74 older adults also participated in a program immediately after the study program). Program had 4 sessions (8 hours) once a week. Data were collected before the program, immediately after and 4 weeks after the program was completed and were analyzed with paired t-test. Results: The level of a satisfaction, interest and understanding of the program were high. Significant differences were found in the health state, the flexibility of neck and shoulder joints and joint exercise habits between the scores before the program started and 4 weeks after it finished. Conclusion: This results suggest that the joint health promotion program for older adults in the community developed this study is effective. So this program can be recommended as an effective nursing intervention for joint health promotion in older adults living in the community.

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인지행동적 분노관리 프로그램이 군인의 자의식과 분노에 미치는 효과 (The Effects of Cognitive Behavioral Anger Management Program on Self-consciousness and Anger in Korean Military Man)

  • 현명선;남경아;강희선
    • 대한간호학회지
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    • 제36권6호
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    • pp.1076-1084
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    • 2006
  • Purpose: The purpose of this study was to evaluate a cognitive behavioral anger management intervention in order to increase self-consciousness and decrease anger among Korean military men, Methods: A quasi-experimental design was used for this study. Ninety two soldiers were screened for unhealthy anger expression using a questionnaire. Among them, 26 soldiers who showed unhealthy anger expression were selected for this study. They were matched by rank and assigned to either a treatment or control group. The treatment group received the intervention three consecutive times, once a week and for 120 minutes per session. Participants were assessed before and after the intervention for anger (the State-Trait Anger Scale) and self-consciousness (Self-consciousness Scale). Data was analyzed using descriptive statistics, $x^2-test$, Mann-Whitney test, and Wilcox on signed rank test. Results: There was no statistically significant decrease in anger or increase in self-consciousness between the two groups following treatment. However, there was a significant increase in private self-consciousness in the treatment group after the intervention(p=.006). Conclusion: The cognitive behavioral anger management program improves private self-consciousness in soldiers. However, Additional research is needed to explore whether long-term intervention is more effective for anger control in the military setting. The findings from this study suggest that more attention should be given to mental health care for Korean soldiers.

Effect of annealing temperature on Al2O3 layer for the passivation of crystalline silicon solar cell

  • Nam, Yoon Chung;Lee, Kyung Dong;Kim, JaeEun;Bae, Soohyun;Kim, Soo Min;Park, Hyomin;Kang, Yoonmook;Lee, Hae-Seok;Kim, Donghwan
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.335.2-335.2
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    • 2016
  • The fixed negative charge of the Al2O3 passivation layer gives excellent passivation performance for both n-type and p-type silicon wafers. For the best passivation quality, annealing is known to be a prerequisite step and a lot of studies concerning annealing effect on the passivation characteristics have been performed. Meanwhile, for manufacturing a crystalline silicon solar cell, firing process is applied to the Al2O3 passivation layer. Therefore, study on not only annealing effect but also on firing effect is necessary. In this work, Al2O3 passivation performance (minority carrier lifetime) for p-type silicon wafer was evaluated with Quasi-Steady-State Photoconductance(QSSPC) measurement after annealing at different temperatures. For the samples which showed different aspects, C-V measurement was performed for the cause - whether it is due to the chemical effect or field-effect. The change in Al2O3 passivation property after firing processes was investigated and the mechanism for the change could be estimated.

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Optimized ultra-thin tunnel oxide layer characteristics by PECVD using N2O plasma growth for high efficiency n-type Si solar cell

  • Jeon, Minhan;Kang, Jiyoon;Oh, Donghyun;Shim, Gyeongbae;Kim, Shangho;Balaji, Nagarajan;Park, Cheolmin;Song, Jinsoo;Yi, Junsin
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.308-309
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    • 2016
  • Reducing surface recombination is a critical factor for high efficiency silicon solar cells. The passivation process is for reducing dangling bonds which are carrier. Tunnel oxide layer is one of main issues to achieve a good passivation between silicon wafer and emitter layer. Many research use wet-chemical oxidation or thermally grown which the highest conversion efficiencies have been reported so far. In this study, we deposit ultra-thin tunnel oxide layer by PECVD (Plasma Enhanced Chemical Vapor Deposition) using $N_2O$ plasma. Both side deposit tunnel oxide layer in different RF-power and phosphorus doped a-Si:H layer. After deposit, samples are annealed at $850^{\circ}C$ for 1 hour in $N_2$ gas atmosphere. After annealing, samples are measured lifetime and implied Voc (iVoc) by QSSPC (Quasi-Steady-State Photo Conductance). After measure, samples are annealed at $400^{\circ}C$ for 30 minute in $Ar/H_2$ gas atmosphere and then measure again lifetime and implied VOC. The lifetime is increase after all process also implied VOC. The highest results are lifetime $762{\mu}s$, implied Voc 733 mV at RF-power 200 W. The results of C-V measurement shows that Dit is increase when RF-power increase. Using this optimized tunnel oxide layer is attributed to increase iVoc. As a consequence, the cell efficiency is increased such as tunnel mechanism based solar cell application.

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Al2O3/SiO2/Si(100) interface properties using wet chemical oxidation for solar cell applications

  • Min, Kwan Hong;Shin, Kyoung Cheol;Kang, Min Gu;Lee, Jeong In;Kim, Donghwan;Song, Hee-eun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.418.2-418.2
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    • 2016
  • $Al_2O_3$ passivation layer has excellent passivation properties at p-type Si surface. This $Al_2O_3$ layer forms thin $SiO_2$ layer at the interface. There were some studies about inserting thermal oxidation process to replace naturally grown oxide during $Al_2O_3$ deposition. They showed improving passivation properties. However, thermal oxidation process has disadvantage of expensive equipment and difficult control of thin layer formation. Wet chemical oxidation has advantages of low cost and easy thin oxide formation. In this study, $Al_2O_3$/$SiO_2/Si(100)$ interface was formed by wet chemical oxidation and PA-ALD process. $SiO_2$ layer at Si wafer was formed by $HCl/H_2O_2$, $H_2SO_4/H_2O_2$ and $HNO_3$, respectively. 20nm $Al_2O_3$ layer on $SiO_2/Si$ was deposited by PA-ALD. This $Al_2O_3/SiO_2/Si(100)$ interface were characterized by capacitance-voltage characteristics and quasi-steady-state photoconductance decay method.

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