• Title/Summary/Keyword: Long Life Test

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Pharmacokinetics and tissue residues of ivermectin in swine

  • Park, Kwon-moo;Park, Jln-bong;Li, Long-hua;Han, Seong-kyu;Lee, Hye-sook;Park, Jong-myung;Chang, Byoung-sun;Lee, Mun-han;Ryu, Pan-dong
    • Korean Journal of Veterinary Research
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    • v.39 no.2
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    • pp.257-266
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    • 1999
  • Ivermectin is a widely used broad spectrum antiparasitic agent in veterinary medicine. In this work, we examined the pharmacokinetic parameters and the tissue residue profile of a new injectable formulation of ivermectin developed for pigs. The plasma ivermectin levels reached the peak at about 9 and 2 hours after the administrations in young and adult pigs, respectively. But the elimination half-life (3-3.5 days) and the $C_{max}$ values (24~28 ng/ml) were not significantly different between young and adult pig groups. When compared to the reference formulation, the $C_{max}$ of test formulation was higher and $T_{1/2}$ values were shorter than those of the reference formulation, respectively. The tissue residue levels were dose- and time-dependent and were higher in the liver and fat, than in the other tissues such as the injection sites, the kidney, intestine, muscle, plasma (4~74 ng/g) at the 7th day after the administration of both formulations of ivermectin. Then, the mean tissue ivermectin levels at the 21st day after the administration in all the tissues decreased to 7.4 and 25% of the 7th day levels in the test and reference formulations, respectively. In general, the tissue levels of ivermectin in the animals treated with the test formulation decreased more rapidly than those with the reference formulation. The tissue to plasma distribution ratio (T/P ratio) of ivermectin was higher in the liver and fat than other tissues. The T/P ratio in the liver of animals treated with the test formulation was somewhat higher than that in the animals treated with the reference formulation. Taken together, the results of pharmacokinetic and tissue residue studies indicate that the test formulation of ivermectin for subcutaneous injection is comparable to the reference formulation, but unique in that it has higher peak plasma concentrations, shorter elimination half-life and higher T/P ratio in the liver than the reference formulation.

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Distribution and Trend Analysis of the Significant Wave Heights Using KMA and ECMWF Data Sets in the Coastal Seas, Korea (KMA와 ECMWF 자료를 이용한 연안 유의파고의 분포 및 추세분석)

  • Ko, Dong Hui;Jeong, Shin Taek;Cho, Hong Yeon;Seo, Kyoung Sik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.3
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    • pp.129-138
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    • 2017
  • The coastal wave environment is a very important factor that directly affects the change of coastal topography, the habitat of marine life, and the design of offshore structures. In recent years, changes in the wave environment due to climate change are expected, and a trend analysis of the wave environment using available data sets is required. In this paper, significant wave heights which are measured at six ocean buoys (Deokjeokdo, Oeyeondo, Chibaldo, Marado, Pohang, Ullengdo) have been used to analyze long-term trend of normal waves. In advance, the outlier of measured data by Korea Meteorological Administration have been removed using Rosner test. And Pearson correlation analysis between the measured data and ECMWF reanalysis data has been conducted. As a results, correlation coefficient between two data were 0.849~0.938. Meanwhile, Mann-Kendall test has been used to analyze the long-term trend of normal waves. As a results, it was found that there were no trend at Deokjeokdo, Oeyeondo and Chibaldo. However, Marado, Pohang and Ullengdo showed an increasing tendency.

Mechanical Deterioration of Overhead Transmission Lines by Forest Fires (산불에 의한 가공 송전선로의 기계적 열화 특성)

  • 김영달;김성덕;심재명;정동화;강지원
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.6
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    • pp.26-34
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    • 2000
  • The considerations for remaining life of ACSR (Aluminum Stranded Conductors Steel Reinforced) in transmission lines have become gradually important to hold reliability and stability of power supply. The remaining life of ACSR exposed to the atmosphere for a long period may rely on deterioration caused by environmental indices such as atmospheric corrosion, galvanic corrosion, crevice corrosion and fatigue corrosion. One of reduction of useful life in overhead transmission lines built on the ridge of mountain is often caused by forest fires.This paper deals with investigation of strength deterioration performance of ASCR due to fires through several testing and analyzing data for tension load and extension of blazed ACSR. Test samples are ACSR 480[$\textrm{mm}^2$] conductors, which are artificially fired to regular durations. Mechanical properties such as tension load and extension for fired ACSR conductors are tested and estimation functions for mechanical performances corresponding to fire duration are determined. As a result, it can be verified that both tension load and extension of ACSR are reduced by increasing fire duration. Hence, it is obvious that ACSR due to forest fires may lead to mechanical deterioration.

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Application and Evaluation of Spa Town Life Cycle Model through a Case Study of Bath Spa, United Kingdom (관광지 라이프사이클 모형의 검증 - 영국의 바스 온천을 사례로)

  • Young Hee Lee
    • Journal of the Korean Geographical Society
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    • v.38 no.3
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    • pp.413-425
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    • 2003
  • This article aims to validate empirically and verify theoretically, the applicability of the spa town life cycle model to Bath Spa located in United Kingdom. In order to test the model, the indicators of the model that associated with the rate of transportation infrastructure, the length of stay, tourist facilities, competitive resorts, advertising, tourism policy, environmental problem and the attitude of residents were examined through a comparative analysis. According to the result of this research, the indicators of 7 items excepting competitive resorts applied to Bath Spa. The competitive resorts of Bath Spa emerge at the maturity stage differing from the model that appeared at the stagnation stage. In conclusion if the new hypothesis of competitive resorts is added to the model, the model will be applied to western spa town, which has a small scale and a long history.

Selection of Probability Distribution of Pavement Life Based on Reliability Method (신뢰성 개념을 이용한 적정 포장 수명분포 선정)

  • Do, Myung-Sik;Kwon, Soo-Ahn
    • International Journal of Highway Engineering
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    • v.12 no.1
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    • pp.61-69
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    • 2010
  • In this paper, we present the methodology about an optimal probability distribution selection as well as survival rate estimation with the national highway database from 1999 to 2008. Probability paper methods are adopted to estimate the parameters of each hazard model. The goodness-of-fit test, such as the Anderson-Darling statistics, was performed. As a result, we found that Lognormal distributionan is an appropriate distribution of newly constructed sections as well as overlayed sections. We also ascertained that the results of survival rate for pavement life between the proposed method and observed data are similar. Such a selection methodology and measures based on reliability theory can provide useful information for maintenance plans in pavement management systems as long as additional life data on pavement sections are accumulated.

Clinical Diagnosis and Its Medical Managements from Patients with Gastrointestinal Diseases (위장관 질환자의 임상진단과 치료방법)

  • 김재웅
    • The Korean Journal of Food And Nutrition
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    • v.10 no.2
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    • pp.186-192
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    • 1997
  • Endoscopic diagnosis and medical management from K43 and C45 patients, whose sex, occupation, character and life patterns are quite different each other, were discussed. The K43 was patient with erosive gastritis, which may caused by maldietary habits and life stresses. Although the effective drugs such as H2-receptor antagonists with atacids, H+/K+-pump inhibitors, prokinetics, colloidal bismuth, and sucralfates, were administrated for long time, symptomatic relief of abdominal pain was not improved. The tests of clinical phathology and abdominal sonogram were normal, visceral hypersensitivity was appeared from barostat test of stomach. However C45 had taken headache during every day life, and endoscopically confirmed as a gastric·duodenal ulcer patiant, which may caused by chronic use of NSAIDs. The her ulceric symptoms were suppressed from active stage to healing stage by using combination therapy for H. pylori with traditional antipeptic ulcer drugs, where as amitriptyline was administrated to the K43 but not effective. Nonulcer dyspepsia and irritable bowel syndrome is pooly defined, and affect about 15% of the population annually in U. S. A. but don't seek medical care. Author would like to point out that statistics for visceral pains are absent in Korea.

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Whole-life wind-induced deflection of insulating glass units

  • Zhiyuan Wang;Junjin Liu;Jianhui Li;Suwen Chen
    • Wind and Structures
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    • v.37 no.4
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    • pp.289-302
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    • 2023
  • Insulating glass units (IGUs) have been widely used in buildings in recent years due to their superior thermal insulation performance. However, because of the panel reciprocating motion and fatigue deterioration of sealants under long-term wind loads, many IGUs have the problem of early failure of watertight properties in real usage. This study aimed to propose a statistical method for wind-induced deflection of IGU panels during the whole life service period, for further precise analysis of the accumulated fatigue damage at the sealed part of the edge bond. By the estimation of the wind occurrence regularity based on wind pressure return period, the events of each wind speed interval during the whole life were obtained for the IGUs at 50m height in Beijing, which are in good agreement with the measured data. Also, the wind-induced deflection analysis method of IGUs based on the formula of airspace coefficient was proposed and verified as an improvement of the original stiffness distribution method with the average relative error compared to the test being about 3% or less. Combining the two methods above, the deformation of the outer and inner panes under wind loads during 30 years was precisely calculated, and the deflection and stress state at selected locations were obtained finally. The results show that the compression displacement at the secondary sealant under the maximum wind pressure is close to 0.3mm (strain 2.5%), and the IGUs are in tens of thousands of times the low amplitude tensile-compression cycle and several times to dozens of times the relatively high amplitude tensile-compression cycle environment. The approach proposed in this paper provides a basis for subsequent studies on the durability of IGUs and the wind-resistant behaviors of curtain wall structures.

Prospero Homeobox 1 and Doublecortin Correlate with Neural Damage after Ischemic Stroke

  • Dong-Hun Lee;Eun Chae Lee;Sang-Won Park;Ji young Lee;Kee-Pyo Kim;Jae Sang Oh
    • Journal of Korean Neurosurgical Society
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    • v.67 no.3
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    • pp.333-344
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    • 2024
  • Objective : Markers of neuroinflammation during ischemic stroke are well characterized, but additional markers of neural damage are lacking. The study identified associations of behavioral disorders after stroke with histologic neural damage and molecular biological change. Methods : Eight-week-old, 25 g male mice of the C57BL/6J strain were subjected to middle cerebral artery occlusion (MCAO) to induce ischemic stroke. The control group was a healthy wild type (WT), and the experimental group were designed as a low severity MCAO1 and a high severity MCAO2 based on post-stroke neurological scoring. All groups underwent behavioral tests, realtime polymerase chain reaction, triphenyltetrazolium chloride (TTC) staining and Hematoxylin and Eosin staining. One-way analysis of variance was used to analyze statistical significance between groups. Results : In TTC staining, MCAO1 showed 29.02% and MCAO2 showed 38.94% infarct volume (p<0.0001). The pro-inflammatory cytokine interleukin (IL)-1β was most highly expressed in MCAO2 (WT 0.44 vs. MCAO1 2.69 vs. MCAO2 5.02, p<0.0001). From the distance to target in the Barnes maze test, WT had a distance of 178 cm, MCAO1 had a distance of 276 cm, and MCAO2 had a distance of 1051 (p=0.0015). The latency to target was 13.3 seconds for WT, 27.9 seconds for MCAO1, and 87.9 seconds for MCAO2 (p=0.0007). Prospero homeobox 1 (Prox1) was most highly expressed in MCAO2 (p=0.0004). Doublecortin (Dcx) was most highly expressed in MCAO2 (p<0.0001). Conclusion : The study demonstrated that histological damage to neural cells and changes in brain mRNA expression were associated with behavioral impairment after ischemic stroke. Prox1 and Dcx may be biomarkers of neural damage associated with long-term cognitive decline, and increased expression at the mRNA level was consistent with neural damage and long-term cognitive dysfunction.

Prediction of Life Time of Ion-exchange Membranes in Vanadium Redox Flow Battery (바나듐 레독스 흐름전지용 이온교환막의 수명 예측)

  • Cho, Kook-Jin;Park, Jin-Soo
    • Journal of the Korean Electrochemical Society
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    • v.19 no.1
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    • pp.14-20
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    • 2016
  • Vanadium redox flow battery (VRFB) is an energy conversion device in which charging and discharging are alternatively carried out by oxidation and reduction reactions of vanadium ions with different oxidation states. VRFB consists of electrolyte, electrode, ion-exchange membrane, etc. The role of ion-exchange membranes in VRFB separates anolyte and catholyte and provides a high conductivity to hydrogen ions. Recently much attention has been devoted to develop ideal ion-exchange membranes for VRFB. A number of developed ion-exchange membranes should be evaluated to find out ideal ion-exchange membranes for VRFB. Long-term durability test is a crucial characterization of ion-exchange membranes for commercialization, but is very time-consuming. In this study, the life time prediction protocol of ion-exchange membranes in VRFB cell tests was developed through short-term single cell performance evaluation (real total operation time, 87.5 hrs) at three different current densities. We confirmed a decrease in test time up to 96.2% of real durability tests (expected total operation time, 2,296 hrs) and 5~6% of relative error discrepancy between the predicted and the real life time in a unit cell.

Effect of Deboning Time on Quality Characteristics of Pressed Pork Ham (돈육 뒷다리 부위의 발골시간이 프레스햄의 품질 특성에 미치는 영향)

  • Yang, H.S.;Joo, S.T.;Park, Gu-Boo
    • Journal of Animal Science and Technology
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    • v.49 no.3
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    • pp.387-394
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    • 2007
  • To investigate the effects of deboning time and muscle type of ham on quality characteristics of cooked press ham, a total of twelve pigs(barrow, 100±5kg) were slaughtered and split in half. The left side ham of carcasses was deboned immediately after slaughter whereas the right side ham was deboned after chilling for 24 hours at 4℃. Each of two muscles(SM; Semimembranosus, BF; Biceps femoris) was used to make a press ham. The pH of hot-boning muscles was significantly(p<0.05) higher than that of cold- boning muscles, and the pH of SM samples was significantly(p<0.05) higher than BF samples. Hot-boning muscles showed significantly(p<0.05) longer sarcomere length compared with cold-boning muscles. There was no significant difference in myoglobin(Mb) percentage between SM and BF muscles, but SM samples of hot-boning showed significantly(p<0.05) lower L* value compared to hot-boning BF samples. The lightness(L*) of hot-boning muscles was significantly(p<0.05) lower than that of cold-boning muscles. These results suggested that the dark color of hot-boning samples might be due to not only the high muscle pH but also the long sarcomere length without difference in Mb percentage. Hardness and gumminess of hot-boning press ham were significantly(p<0.05) lower than those of cold-boning samples. These results implied that color and pH of press ham did not affected by deboning time or muscle type of ham. However data suggested that texture and panel test of press ham might be improved by using hot-boned muscle due to long sarcomere length of raw meat.