• Title/Summary/Keyword: Half Life Time

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Elucidation of Environment Factors Affecting the Differences in the Half-Life of the Insecticide Cyfluthrin in Soil between Field and Laboratory Tests (포장과 실내실험에서 살충제 Cyfluthrin의 토양 중 반감기 차이에 미치는 환경요인 구명)

  • Lim, Bang-Hyun;Lim, Yo-Sup;Choi, Yong-Hwa;Han, Seong-Soo
    • Applied Biological Chemistry
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    • v.43 no.4
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    • pp.291-297
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    • 2000
  • This study was conducted to find out the environmental factors affecting the differences in the half-life of the insecticide cyfluthrin in soil between field and laboratory tests carried out in 1998. Degradation and leaching of cyfluthrin in soil were examined under various environmental conditions that were considered to affect the residuality. Cyfluthrin was degraded 1.9 times faster in non-sterilized soil than in sterilized soil and 1.2 times at $25^{\circ}C$ than at $15^{\circ}C$. The half-lives of cyfluthrin were 61.4 days under the dark condition and 4.5 days under sunlight, and those were 11.8 days under the open condition and 23.8 days under the closed condition. The half-lives of the authentic compound and the commercial product of cyfluthrin were 15 and 1 day in the field test and 26 and 3 days in the laboratory test, respectively. Cyfluthrin was rapidly degraded with an increase in soil moisture content and decomposed faster in the alkaline solution of pH 12 than in the acidic solution of pH 3, but the half-life of cyfluthrin did not make any difference between pH 6.4 of the field test soil and pH 5.6 of the laboratory test soil. Cyfluthrin was immobile in soil from the results that $81{\sim}94%$ of the initial amount remained in the $0{\sim}2\;cm$ layer of the soil column regardless of the amount and time of rainfall after the chemical treatments. From viewing the abovementioned results, soil moisture content, sunlight and formulation type affected greatly soil microbes and volatilization affected slightly, and temperature, pH and rainfall did not affect the big difference in the half-life of cyfluthrin in soil between the field and laboratory tests in the year of 1998.

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Research of Seokgok(石谷), Lee Gyu Jun(李圭晙)'s Chinese Poem (석곡(石谷) 이규준(李圭晙)의 한시 연구)

  • Lee, Jun-Gyu
    • Korean Journal of Oriental Medicine
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    • v.18 no.2
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    • pp.17-24
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    • 2012
  • Research on Seokgok(石谷), Lee Gyu Jun(李圭晙, 1855~1923)'s thought and medicine was progressed from various angles. There is no research on Chinese poem(漢詩) accounting for the half of his collection of literary works, "Seokgoksango(石谷散稿)" yet. Hence, the article reviewed concerns on his life and what life he lived as a Confusion(儒家) writer through his Chinese poem. Should read "Seokgoksango", Seokgok's spiritual orientation and attitude to life were found to have its core in the Confusion(儒家的), especially ethical(道學的) aspect. Seokgok's Chinese poem materialized his spiritual composition more, able to access up to general emotional state, representing concerns and frustration of intellectuals in the latter era of the Choson Dynasty. Anxiety consciousness(憂患) of patriotism and love of the people which traditional intellectuals implicated enough at the turbulent era of early modern time appeared strongly in his works. Also works seeking for devotion(歸依) toward the clean world(淸明世界) staring at the corrupt world losing the national sovereignty at the same time and the expansion(擴散) was able to be found many. The latter half of the 19th century and the early 20th century when Seokgok lived was the period of changeover in the history of civilization called intersection between traditional era and modern times. His Chinese poem showed traditional intellectuals' anxiety, frustration, conflict, and hope based on such times. Along with the status of an Oriental, medical doctor and thinker, up to discussion on the quality of a writer, the intensified research on him is expected.

Fault-tree based reliability analysis for paralleled half-bridge sub-module of HVDC (HVDC 병렬 하프브리지 서브모듈에 대한 고장나무기반의 신뢰성 분석)

  • Kang, Feel-soon;Song, Sung-Geun
    • Journal of IKEEE
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    • v.23 no.4
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    • pp.1218-1223
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    • 2019
  • In HVDC systems, the full-bridge submodule increases the number of components compared to the half-bridge submodule, but the failure-rate can be reduced by securing 100 % redundancy. However, full-bridge submodules require more complex control algorithms to ensure the redundancy and to prevent arm-short with sufficient dead-time. To solve this problem, we analyse the failure-rate of the paralleled half-bridge configuration with the same number of components and 100 % redundancy as the full-bridge submodule. The fault tree analysis (FTA) method is applied to the conventional part failure analysis to reflect the operation risk of the submodule, thereby predicting the life-cycle of the submodule more accurately. To verify the validity, the failure-rate results of the proposed FTA based analysis method are compared with the failure rate obtained by the part failure method.

Distributions of Local Supply and Exhaust Effectiveness according to the Room Airflow Patterns (실내 기류패턴에 따른 급기효율과 배기효율의 분포)

  • 한화택;최선호;장경진
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.9
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    • pp.853-859
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    • 2001
  • A pulsed tracer gas technique is applied to measure distributions of local mean age and residual life time of air in a half-scale experimental chamber. The room airflow patterns are flow-visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is either at bottom-left(Case 1), bottom-right(Case 2), or top-left(Case 3) location. Results show that the distribution of LMA and LMR are different from each other, but both of them are closely related to the airflow pattern in the space. Results on overall room ventilation effectiveness are provided depending upon ventilation airflow rates for three different supply-exhaust configurations.

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Study on Bladder Dysfunction in Elderly Women by the BFLUT Questionnaire and Bladder Scanner: Frequency and Residual Urine (질문지법과 초음파 방광용적진단기를 이용한 여성노인의 배뇨장애연구 -빈뇨, 잔뇨를 중심으로)

  • Kim, Jeung-Im
    • Women's Health Nursing
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    • v.17 no.3
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    • pp.294-303
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    • 2011
  • Purpose: This study aimed to describe bladder dysfunction in elderly women such as frequency, nocturia, and residual urine. Methods: One hundred elderly women aged 60 and over. The Bristol Female Lower Urinary Symptoms (BFLUT) was used to evaluate the bladder function and to measure the residual urine amount by using a bladder scanner. Data was analyzed with the differences between voiding dysfunction by age group and life habits by t-test, ANOVA and correlation by Pearson correlation coefficient. Results: the mean daytime frequency was 6.8 times and night-time frequency 2.7 times. Sixty three percent of subjects had urgency and 41% had urgent incontinence. Over half of subjects had problem in voiding function. There were significant differences in frequency by age groups and constipation, but not in daytime frequency and residual urine. Lastly, there were significant positive relations between daytime frequency and night-time frequency. Also results indicate that more frequency in daytime equaled to a less residual urine amount. Conclusion: We know many elderly women have lower urinary tract symptoms. Specially women over 75 years have more daytime frequency and night-time frequency. This suggests further research needed in order to understand the relation of voiding patterns and life habits and its influence on quality of life.

Marination and Physicochemical Characteristics of Vacuum-aged Duck Breast Meat

  • Khan, Muhammad Issa;Lee, Hyun Jung;Kim, Hyun-Joo;Young, Hae In;Lee, Haelim;Jo, Cheorun
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.11
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    • pp.1639-1645
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    • 2016
  • We investigated marinade absorption and physicochemical characteristics of vacuum-aged duck breasts that were halved and individually vacuum-packed for chiller aging at $4^{\circ}C$ for 14 d. One half was marinated for 0, 7, or 14 d, while the second half was used as a control. Marinade absorption, cooking loss, cooking yield, texture profile, pH, color, protein solubility, and thiobarbituric acid reactive substances (TBARS) values were evaluated, and protein sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed. Marinade absorption and pH did not vary significantly after 14 d of aging. Marination increased the pH, color ($a^*$ and $b^*$) values, and cooking yield and reduced cooking loss. TBARS values significantly increased with aging time, but were significantly reduced by marination. Myofibril and total protein solubility increased with aging and marination, while SDS-PAGE showed protein degradation. Hence, aging and marination can be used simultaneously to improve physicochemical quality and cooking yield of vacuum-aged duck breast.

The residue property of fungicide boscalid and fluidioxonil at the same time harvest leafy-vegetables (일시수확 엽채류에서 살균제 Boscalid와 Fludioxonil의 잔류특성)

  • Bae, Byung-Jin;Lee, Hae-Kuen;Son, Kyeong-Ae;Im, Geon-Jae;Kim, Jin-Bae;Kim, Tae-Hwa;Chae, Seok;Park, Jong-Woo
    • The Korean Journal of Pesticide Science
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    • v.16 no.2
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    • pp.98-108
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    • 2012
  • In order to use in the classification of minor crop for the mutual application of safe use guideline, it was investigated the residue property of fungicide boscalid and fludioxonil at the same time harvest leafy-vegetables, such as spinach, ulgaribaechu, vitaminchae and cheongkyungchae. After pesticides were applied 2 times with 1 week interval in that day of harvest, 2 days, 5 days and 7 days before harvest, vegetables were harvested, and the residue of pesticides was investigated. Base on the residue in that day of harvest, the deposit of spray solution in vegetables was calculated. The deposit of spray solution of boscalid was 253.9 mL/kg in spinach, 83.0 mL/kg in ulgaribaechu, 97.8 mL/kg in vitaminchae, and 88.3 mL/kg in cheongkyungchae, respectively. In case of fludioxonil, it was calculated 157.6 mL/kg in spinach, 67.6 mL/kg in ulgaribaechu, 64.8 mL/kg in vitaminchae, and 66.6 mL/kg in cheongkyungchae, respectively. When the amount of the deposit of both pesticides was compared in leafy-vegetables, it was the highest in the spinach. On the other hand, it was estimated the predicted dissipation curve of pesticides in leafy-vegetables during cultivation. The half-life of boscalid was 5.9 days in spinach, 7.4 days in ulgaribaechu, 4.6 days in vitaminchae, and 4.3 days in cheongkyungchae, respectively. Also, it was estimated half-life in fludioxonil, it was 3.0 days in spinach, 4.0 days in ulgaribaechu, 3.2 days in vitaminchae, and 3.5 days in cheongkyungchae, respectively. The half-life was the longest in the ulgaribaechu. When both pesticides were compared with the residue property, the deposit of spray solution and half-life of dissipation of boscalid were more than those of fludioxonil.

Pharmacokinetics of Acebutolol and Diacetolol After Oral Administration of Acebutolol in Rabbits with Folate-Induced Renal Failure (신장장애 가토에서 경구투여시 아세부토롤과 활성대사체인 디아세토롤의 약물동태)

  • Choi, Jun-Shik;Lee, Jin-Hwan
    • Journal of Pharmaceutical Investigation
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    • v.31 no.3
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    • pp.161-165
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    • 2001
  • Acebutolol (ABT) is almost absorbed after oral administration, but its bioavailability is reduced because of considerable first-pass metabolism in the gastrointestine and liver. The purpose of this study was to report the pharmacokinetic changes of ABT and its metabolite, diacetolol (DAT) after oral administration of acebutolol to control rabbits and rabbits with mild and severe folate-induced renal failure (FIRRs). Both of the area under the plasma concentration-time curve $(AUC^0_{\infty})$ of ABT and DAT were significantly increased in mild (p<0.05) and severe FIRRs (p<0.01), but the $AUC^0_{\infty}$ of DAT was more influenced than that of ABT in severe rabbits. There was a good correlation between serum creatinine and both of $AUC^0_{\infty}$ of ABT and DAT. The elimination half-life of ABT and DAT was significantly prolonged in mild (p<0.05) and severe (p<0.01) FIRRs, but the half-life of DAT was more influenced than that of ABT in severe FIRRs. The results suggest that the dosage of acebutolol should be adjusted according to the degree of renal disorder on the base of the serum creatinine concentration.

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High operating temperature stable OLEDs with reduced reflectivity cathodes

  • Popovic, Zoran D.;Aziz, Hany;Vamvounis, George;Hu, Nan-Xing;Paine, Tony
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.21-24
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    • 2003
  • The understanding of the mechanism of device degradation has been accomplished recently, for devices using $AlQ_3$ electron transport and emitter molecule. In this presentation the experimental evidence for the degradation mechanism of $AlQ_3$ based devices will be reviewed, showing that the hypothesis of an unstable $AlQ_3^+$ cation explains a large amount of experimental data. This hypothesis, however, explains not only the room temperature device degradation in time but also sheds light on temperature stability of OLEDs. Dependence of half-life of a series of devices with an emitter layer composed of a mixture of $AlQ_3$ and different hole transport molecules (mixed emitter layer) will be discussed when they are operated at elevated temperatures. These results can also be explained in the framework of an unstable $AlQ_3^+$ species. An OLED structure containing a doped mixed emitter layer will be described, which shows extraordinary stability, half-life of 1200 hours at operating temperature of 70 C and initial luminance of 1650 $cd/m^2$. We will also discuss a novel Black $Cathode^{TM}$ OLED with reduced optical reflectivity, which is also stable at elevated temperatures. The new cathode utilizes a conductive light-absorbing layer made of a mixture of metals and organic materials.

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Ceramide-Mediated c-jun Gene Expression in U-937 Cells (U-937 세포에 있어서 세라마이드에 의한 c-jun 유전자 발현의 조절)

  • Kim, Won-Ho;Kim, Mie-Young;Choi, Kyung-Hee
    • YAKHAK HOEJI
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    • v.41 no.1
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    • pp.81-85
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    • 1997
  • Ceramide has been suggested as an important mediator of the effects of extracellular agonists on cell growth inhibition, differentiation, apoptosis. However the biochemical sign aling mechanism involved in transducing the effects of ceramide on leukemia cell differentiation is still unclear. In these respects, we examined the regulatory effects of ceramide on c-jun gene expression during differentiation. In U-937 cells. ceramide increased c-jun mRNA levels in a time-dependent manner. The half life, of c-jun mRNA was 30 min. In contrast, inhibition of protein synthesis with cycloheximide in the absence, of transcription with actinomycin D increased the half-life of c-jun mRNA in ceramide-treated U-937 cells to more than 90 min. In order to examine whether ceramide-inhibited c-jun gene expression is regulated through ceramide-activated protein phosphatase (CAPP), a direct target for the action of ceramide, okadaic acid were treated to the cells. Okadaic acid inhibited enhancement of c-jun mRNA induced by C2-ceramide in a dose-dependent manner. These results suggested that ceramide increases c-jun mRNA level during differentiation in U-937 cells and regulates the gene expression on posttranscriptional level. In addition, we provide the evidence that CAPP is involved in ceramide-induced c-jun gene expression in U-937 cells.

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