• Title/Summary/Keyword: critical experiment

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Designing a Highly Sensitive Eddy Current Sensor for Evaluating Damage on Thermal Barrier Coating (열차폐코팅의 비파괴적 손상 평가를 위한 고감도 와전류 센서 설계)

  • Kim, Jong Min;Lee, Seul-Gi;Kim, Hak Joon;Song, Sung Jin;Seok, Chang Seong;Lee, Yeong-Ze
    • Journal of the Korean Society for Nondestructive Testing
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    • v.36 no.3
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    • pp.202-210
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    • 2016
  • A thermal barrier coating (TBC) has been widely applied to machine components working under high temperature as a thermal insulator owing to its critical financial and safety benefits to the industry. However, the nondestructive evaluation of TBC damage is not easy since sensing of the microscopic change that occurs on the TBC is required during an evaluation. We designed an eddy current probe for evaluating damage on a TBC based on the finite element method (FEM) and validated its performance through an experiment. An FEM analysis predicted the sensitivity of the probe, showing that impedance change increases as the TBC thermally degrades. In addition, the effect of the magnetic shield concentrating magnetic flux density was also observed. Finally, experimental validation showed good agreement with the simulation result.

Public Participation in Healthcare Decision Making : Experience of Citizen Council for Health Insurance (보건의료 정책 의사결정과 시민참여 : 『건강보험 보장성 시민위원회』의 사례)

  • Kwon, Soonman;You, Myoungsoon;Oh, Juhwan;Kim, Soojung;Jeon, Boyoung
    • Health Policy and Management
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    • v.22 no.4
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    • pp.467-496
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    • 2012
  • Public participation in the decision making for scarce health resources is important because health policy requires trust based consensus, which can be achieved by public's understanding and involvement of related policies. In the past, opportunities for interaction between health policy decision makers and lay public were rare in Korea. As political impulses towards public participation in health policy have increased, a few of deliberation methods were attempted. However, there is little research, reporting such cases with a critical examination of relevant theories and previous studies. We first critically review the literature on public participation within theories of democracy, governance, and empowerment. Next, we report a case of a citizen council experiment, which was held to examine public's preferences among different benefit options regarding new drugs and medical technologies. Specifically, in an one-day long citizen council with a total of 28 lay public, twelve questions of whether a drug or a technology should be included in the benefit package of health insurance were asked. Pre- and post-surveys investigated participants' perception of public engagement in health policy. Although it was experimental, the citizen council ensured that lay public could be careful enough to rationally compare the costs and benefits of different options and collectively make decisions. Further, results from pre- and post-survey showed a strong willingness of members to be involved in health care decision making. In the conclusion, we emphasize that better theories and methods need to be developed for more cases of citizen participation in health care policy and management.

Effect of Gardenia Jasminoides on Insulin Resistance Induced by Non-alcoholic Fatty Liver Disease (치자 추출물의 지방대사조절을 통한 비알콜성 지방간 유도 인슐린저항성 개선 효과)

  • Seo, Il-bok;Ahn, Sang Hyun;Jeong, Han Sol;Kim, Ki Bong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.33 no.5
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    • pp.288-294
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    • 2019
  • Gardenia jasminoides is an herbal medicine that treats obesity and dampness-phlegm. This study aimed to investigate the efficacy of Gardenia jasminoides on insulin resistance induced by Non-alcoholic fatty liver disease (NAFLD). 8-week-old C57BL/6 male mice were divided into three groups: control group (Ctrl), high-fat diet group (HFF), and high fat diet with Gardenia jasminoides extract administration group (GJT). Each 10 mice was allocated to each group (a total of 30 mice). All mice were allowed to eat fat-rich diet freely throughout the experiment. To examine the effect of Gardenia jasminoides, we observed weight changes, lipid blot distributions, PPAR-${\gamma}$, p-IkB, p-JNK in liver tissue, total cholesterol, and glucose levels in serum. Comparing of body weight measurements between 3 groups, in the GJT group, weight gain was significantly suppressed compared to the HFF group. The distribution of lipid blots and positive reaction of PPAR-${\gamma}$ were significantly lower in GJT group. The expression levels of p-$I{\kappa}B$ and p-JNK that plays critical roles in the development of insulin resistance were significantly decreased by GJ treatment. Total cholesterol and glucose levels in serum were also significantly lower in GJT group. Gardenia jasminoides has the effect of improving non - alcoholic fatty liver induced insulin resistance through the regulation of lipid metabolism.

Shell Valve Movement of Pacific Oysters, Crassostrea gigas, in Response to Low Salinity Water (저염수에서 이매패류 참굴(Crassostrea gigas)의 패각운동)

  • Moon, Suyeon;Oh, Seok Jin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.684-689
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    • 2017
  • We examined the possibility of developing an early monitoring system using the shell valve movement activity of Pacific oyster (Crassostrea gigas) for early detection of low salinity water in coastal areas. At salinity levels of 30 psu and 20 psu, SVMs were detected $7.32{\pm}3.21times/hr$ and $7.11{\pm}3.90times/hr$, respectively, The patterns and times of SVMs were not significantly different between the two experiment phases. However, at 10 psu and 5 psu, shell valves were observed to be permanently closed in all experiments. Under combined condition (Group 1: temperature $15^{\circ}C$ ${\times}$ salinity 15 psu), SVMs were observed from 20 psu to 30 psu over a 2 - 3 hr period, and then remained closed. In Group 2 (temperature $30^{\circ}C$ ${\times}$ salinity 15 psu), SVMs were observed, which indicated that the physiological condition of the oysters reached a critical point. Thus, it may be possible to utilize SVMs as an early warning signal for low salinity water.

Prediction of Thermal-Hydraulic Phenomena in the LBLOCA Experiment L2-3 Using RELAP5/MOD2 (RELAP5/MOD2 코드에 의한 대형냉각재 상실사고 모사실험 L2-3의 열수력 현상 예측)

  • Bang, Young-Seok;Chung, Bub-Dong;Kim, Hho-Jung
    • Nuclear Engineering and Technology
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    • v.23 no.1
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    • pp.56-65
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    • 1991
  • The LOFT LOCE L2-3 was simulated using the RELAP5/MOD2 Cycle 36.04 code to assess its capability in predicting the thermal-hydraulic phenomena in LBLOCA of a PWR. The reactor vessel was simulated with two core channels and split downcomer modeling for a base case calculation using the frozen code. The result of the base calculation showed that the code predicted the hydraulic behavior, and the blowdown thermal response at high power region of the core reasonably and that the code had deficiencies in the critical How model during subcooled-two-phase transition period, in the CHF correlation at high mass flux and in the blowdown rewet criteria. An overprediction of coolant inventory due to the deficiencies yielded the poor prediction of reflood thermal response. Improvement of the code, RELAP5 / MOD2 Cycle 36.04, based on the sensitivity study increased the accuracy of the prediction of the rewet phenomena.

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Non-destructive Analysis of Nano-Cementitious Composites Using Ultrasonic and Electrical Resistance (초음파 및 전기저항을 활용한 나노-시멘트 복합체의 비파괴 분석)

  • Shin, Yangsub;Lee, Heeyoung;Cho, Sanghyeon;Park, Sohyeon;Chung, Wonseok
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.3
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    • pp.322-329
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    • 2021
  • Nano-cementitious composites may have defects due to poor dispersion of nanomaterials and fabrication process. These defects can cause critical problems for nano-cementitious composites, but studies related to non-destructive analysis of defects sizes inside nano-cementitious composites are insufficient. This study aims to perform non-destructive analysis of nano-cementitious composites by utilizing ultrasonic and electrical resistance. Various sizes of defects were implemented inside the specimens and the specimens were subjected to ultrasonic non-destructive analysis and electrical resistance non-destructive analysis depending on the size of defects and curing days. As a result of the experiment, ultrasonic pulse velocity decreased by up to 11% as the defects size increased, and the electrical resistance increased by up to 14% depending on the defects size. For this reason, this study concluded that non-destructive analysis using ultrasonic and electrical resistance can predict defects inside nano-cementitious composites.

Modified Renshen Wumei Decoction Alleviates Intestinal Barrier Destruction in Rats with Diarrhea

  • Guan, Zhiwei;Zhao, Qiong;Huang, Qinwan;Zhao, Zhonghe;Zhou, Hongyun;He, Yuanyuan;Li, Shanshan;Wan, Shifang
    • Journal of Microbiology and Biotechnology
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    • v.31 no.9
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    • pp.1295-1304
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    • 2021
  • Modified Renshen Wumei decoction (MRWD), a famous traditional Chinese medicine, is widely used for treating persistent diarrhea. However, as the mechanism by which MRWD regulates diarrhea remains unknown, we examined the protective effects of MRWD on intestinal barrier integrity in a diarrhea model. In total, 48 male rats were randomly distributed to four treatment groups: the blank group (CK group), model group (MC group), Medilac-Vita group (MV group) and Chinese herb group (MRWD group). After a 21-day experiment, serum and colon samples were assessed. The diarrhea index, pathological examination findings and change in ᴅ-lactate and diamine oxidase (DAO) contents illustrated that the induction of diarrhea caused intestinal injury, which was ameliorated by MV and MRWD infusion. Metabolomics analysis identified several metabolites in the serum. Some critical metabolites, such as phosphoric acid, taurine, cortisone, leukotriene B4 and calcitriol, were found to be significantly elevated by MRWD infusion. Importantly, these differences correlated with mineral absorption and metabolism and peroxisome proliferator-activated receptor (PPAR) pathways. Moreover, it significantly increased the expression levels of TLR4, MyD88 and p-NF-κB p65 proteins and the contents of IL-1 and TNF-α, while the expression levels of occludin, claudin-1 and ZO-1 proteins decreased. These deleterious effects were significantly alleviated by MV and MRWD infusion. Our findings indicate that MRWD infusion helps alleviate diarrhea, possibly by maintaining electrolyte homeostasis, improving the intestinal barrier integrity, and inhibiting the TLR4/NF-κB axis.

Resistance of Oryza sativa and Oryza glaberrima Genotypes to RBe24 Isolate of Rice Yellow Mottle Virus in Benin and Effects of Silicon on Host Response

  • Anato, Vital Kouessi Sixte;Agnoun, Yves;Houndjo, Joel;Oludare, Aderonke;Agbangla, Clement;Akoroda, Malachy;Adetimirin, Victor O.
    • The Plant Pathology Journal
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    • v.37 no.4
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    • pp.375-388
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    • 2021
  • Rice yellow mottle virus (RYMV) is the most harmful virus that affects irrigated and lowland rice in Africa. The RBe24 isolate of the virus is the most pathogenic strain in Benin. A total of 79 genotypes including susceptible IR64 (Oryza sativa) and the resistant TOG5681 (O. glaberrima) as checks were screened for their reactions to RBe24 isolate of RYMV and the effects of silicon on the response of host plants to the virus investigated. The experiment was a three-factor factorial consisting of genotypes, inoculation level (inoculated vs. non-inoculated), and silicon dose (0, 5, and 10 g/plant) applied as CaSiO3 with two replications and carried out twice in the screen house. Significant differences were observed among the rice genotypes. Fifteen highly resistant and eight resistant genotypes were identified, and these were mainly O. glaberrima. Silicon application did not affect disease incidence and severity at 21 and 42 days after inoculation (DAI); it, however, significantly increased plant height of inoculated (3.6% for 5 g CaSiO3/plant and 6.3% for 10 g CaSiO3/plant) and non-inoculated (1.9% for 5 g CaSiO3/plant and 4.9% for 10 g CaSiO3/plant) plants at 42 DAI, with a reduction in the number of tillers (12.3% for both 5 and 10 g CaSiO3/plant) and leaves (26.8% for 5 g CaSiO3/plant and 28% for 10 g CaSiO3/plant) under both inoculation treatments. Our results confirm O. glaberrima germplasm as an important source of resistance to RYMV, and critical in developing a comprehensive strategy for the control of RYMV in West Africa.

Evaluation of Punching Shear Safety of a Two-Way Void Plywood Slab System with Form (거푸집 패널이 부착된 2방향 중공슬래브의 뚫림 전단 안전성 평가)

  • Hur, Moo-Won;Woo, Hyung-Sik;Park, Jung-Min;Kang, Hyun-Wook;Park, Tae-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.5
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    • pp.182-189
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    • 2021
  • VPS(Void Plywood Slab System, VPS) has optimized the shape of the hollow material. In addition, it has a function to prevent the floating of the hollow material and the separation due to the working load. In this study, the punching shear capacity of flat plate was performed using Void Plywood Slab System with form work panel proposed in the previous study. As a result of the test, the strength of the VSPS specimen in which the hollow material was placed beyond 2.0 times the column width from the loading point was reduced by 9.4% compared to the reference specimen. However, the strength value was about 1.57 times higher than the design value suggested by KBC 2016. It was found that there was no change in stiffness compared to the reference specimen until shear failure occurred in the VSPS specimen in which the hollow material was placed. It can be seen that this experiment is being destroyed by shear as the flexural reinforcing bars are sufficiently reinforced.

A New Experiment or Institutional Subsumption? The Outcomes and Tasks of Contingent Worker Center for Korean Labor Movement (노동운동의 새로운 시도 혹은 제도적 포섭? 비정규노동센터의 성과와 과제)

  • Noh, Sung-Chul;Jung, Heung-Jun;Lee, Cheol
    • Korean Journal of Labor Studies
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    • v.24 no.2
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    • pp.137-179
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    • 2018
  • To reduce labor market discrimination, there are lively discussions about the role of extant labor regime based on labor unions. It includes both the critical perspective on extant labor movement and the necessity of new actors for resolving discriminations within labor market. Among new actors, the present study focuses on contingent labor centers. Specifically, we have investigated on the development and identity of contingent labor centers as coalition of local government-labor organization. The core content of this study is to reconstruct the activities and strategies of contingent labor centers throughout the longitudinal approach. From many evidences, we can confirm that contingent labor centers have evolved via three phases such as differentiation, de- politicizing, and networks. This finding also provides insights about inside relationships between contingent labor centers and outside tensions between contingent labor center and extant labor organizations. We finally discuss on the theoretical implications of contingent labor center as new actor for contingent worker movement.