• 한국융합학회논문지
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• 제7권6호
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• pp.307-315
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• 2016

본 연구는 인터벌 태권도 프로그램을 통하여 중년비만여성들의 코티졸, 유리지방산 및 근 손상지표에 어떠한 변화가 나타나는지를 알아보고자 하였다. 이를 위해 중년비만 여성을 대상으로 최대심박수를 활용한 80~85%의 운동강도로 매회 40분간 실시되는 인터벌 태권도 운동을 주 3회씩 8주간 실시하였으며, 다음과 같은 결과를 얻었다. 첫째, 코티졸은 8주간 인터벌 태권도 프로그램 전 후 감소를 보였으나 유의한 변화는 나타나지 않았다. 둘째, 유리지방산은 8주간 인터벌 태권도 프로그램 전 후 감소를 보였으며 유의한 변화가 나타났다. 셋째, 근 손상지표는 8주간 인터벌 태권도 프로그램 전 후 감소를 보였으나 유의한 변화는 나타나지 않았다. 본 연구결과를 통해 인터벌 태권도 운동은 스트레스를 이겨내는 내성 및 저항력 향상과 근 손상 예방 효과는 다소 낮았으나, 지방 산화 능력 증가를 위한 운동 프로그램으로 활용될 수 있을 것이라는 결론을 얻었다.

• 대한기계학회논문집A
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• 제22권3호
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• pp.579-587
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• 1998

In this study, fatigue behavior of the optical fiber sensor embedded in composite laminate was investigated. Static tensile and fatigue tests were performed for three types of laminated composite specimens with embedded optical fiber sensor in the neutral plane ; [0/sub 6//OF/0/sub 6/]/sub T/, [0/sub 2//90/sub 4//OF/90/sub 4//0/sub 2/]/sub T/ and [0/sub 3//90/sub 3//OF/90/sub 3//0/sub 3/]/sub T/. The fracture of the embedded optical fiber sensor was detected by the intensity drop off of laser signal transmitted through the optical fiber sensors embedded within laminated composite specimen. The maximum fatigue stress applied to laminated specimen was compared with the average tensile stress at which the fracture of the embedded optical fiber within the laminate occurred under static tensile loading. From the experiments, firstly it is observed that the decrease in the life of optical fiber sensors embedded within unidirectional-ply laminate by the fatigue loading is relatively small compared to that of cross-ply laminate. Secondly, the optical fiber embedded in unidirectional-ply laminate is fractured by the fatigue damage due to the growth of internal defects of optical fiber, however the optical fiber embedded in cross-ply laminate is fractured by the growth of transverse matrix crack.

• Food Science and Biotechnology
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• 제17권5호
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• pp.983-989
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• 2008

Two flavonoids, isorhamnetin 3-O-$\beta$-D-glucopyranoside (1) and quercetin 3-O-$\beta$-D-glucopyranoside (2), from slander glasswort (Salicornia herbacea, Korean name hamcho) were isolated. Antioxidative and matrix metalloproteinase-9(MMP-9) inhibitory effects of these compounds were investigated in HT 1080 cell lines. These compounds suppressed the electron spin resonance (ESR) signal intensity on generation of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in a free-cellular system. Their scavenging effects on generation of intercellular reactive oxygen species (ROS) also exhibited similar trends with DPPH radical in the free cellular system. Also, a control group combined only with Fe(II)-$H_{2}O_2$ resulted in DNA apoptosis by oxidative stress, whereas treatments with these compounds suppressed radical-mediated DNA damage. Intracellular glutathione (GSH) levels were slightly increased in the presence of compound 1 and 2. Moreover, these compounds led to the reduction of the expression levels of MMP-9 without cytotoxic influence. These results suggest that these compounds have a potential as a valuable natural antioxidant and MMP inhibitor related to oxidative stress. Therefore, these compounds not only can be developed as a candidate for a therapeutic potential but also a source for use as ingredients of health foods or functional foods to prevent metastasis involving MMP-9, closely related to ROS.

• 소성∙가공
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• 제16권2호
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• pp.126-131
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• 2007

Voids in a large rotor are formed in solidification process of a cast ingot. The voids have to be eliminated from the rotor by a forming process, because they would became stress-intensity factors which suddenly fracture the rotor in the operation. Previous studies on void-elimination of a large rotor have mainly focused on finding the process variables affecting the void-closure. But the study on the amount of void closure in a large rotor has been very rare. This study was performed to obtain an equation which predicts the amount of void-closure in a forging process of a large rotor and to evaluate the availability of the void-closure equation through finite element analyses. Firstly, 2D FE analysis was carried out to find effects of time integral of hydrostatic stress and effective strain on void volume rate of a large rotor in the upsetting process for various diameters and shapes of void, and material temperature. From the 2D FE analysis, we found that effective strain was suitable for predicting the void-closure of a large rotor, because there was a constant relationship between void volume rate and effective strain. And a void-closure equation was proposed fur predicting void-closure of a large rotor in the upsetting process. Finally, ken the 3D FE analysis, the proposed void-closure equation was verified to be useful for upsetting and cogging processes.

• 한국임상수의학회지
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• 제29권6호
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• pp.494-497
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• 2012

6년령의 수컷 미니어쳐 핀셔견이 천둥소리로 인한 떨림, 빈호흡 및 부적절한 배뇨를 주증으로 내원하였다. 환축은 2년전 발생한 교통사고 이후 큰 소리에 공포감을 가지게 되었으며, 이는 천둥 발생이 잦은 지난 3개월간 지속적으로 나빠졌다. 기본 신체검사에서 미열, 빈호흡, 빈맥과 함께 혈압의 상승이 확인되었다. 실험실 검사에서 동맥혈의 산소포화도 감소와 함께 적혈구증가증이 확인되었다. 병력, 신체검사 및 실험실적 검사를 바탕으로 본 환축은 소리공포증과 함께 발생한 상대적 적혈구증가증으로 진단 되었다. 증상의 완화를 위하여, 행동교정 및 탈감각화, 반대조건화, 그리고 약물치료가 시작되었다. 다른 치료들과 함께 음악치료도 병행되었으며, 치료기간 중 임상증상 및 적혈구증가증이 개선되었다. 따라서, 본 증례는 소리공포증과 같은 만성적인 스트레스에 의하여 발생한 상대적 적혈구증가증의 진단증례 보고 이다.

• 농약과학회지
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• 제14권4호
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• pp.415-420
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• 2010

본 연구는 서로 다른 주파수에 따른 복숭아혹진딧물(Myzus persicae)의 약제 감수성과 그에 따른 효과를 조사하였다. 소리세기를 95 dB로 고정하고 0-5,000 Hz의 서로 다른 주파수 음파를 진딧물의 전체 발육기간에 걸쳐서 처리했다. 처리 음파의 주파수 증가에 따라 진딧물의 유충에서 성충까지의 발육기간이 지연되었고，암컷 성충의 생식력을 감소시켰다. 이차원 전기영동분석 결과는 5,000 Hz의 음파로 처리된 진딧물이 대조구에 비해 체내의 단백질의 변화가 있었음을 나타냈다. 2,000 Hz 이상의 음파 처리는 이미다클로프리드 약제에 대한 진딧물의 감수성을 증가시켰다. 본 연구는 복숭아혹진딧물이 감응하는 스트레스 음파가 존재하며, 이는 이 해충의 생리적 교란을 유발한다는 것을 제시하고 있다.

• International Journal of Concrete Structures and Materials
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• 제10권2호
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• pp.163-175
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• 2016

This paper presents a revised procedure for computation of double-K fracture parameters of concrete split-tension cube specimen using weight function of the centrally cracked plate of finite strip with a finite width. This is an improvement over the previous work of the authors in which the determination of double-K fracture parameters of concrete for split-tension cube test using weight function of the centrally cracked plate of infinite strip with a finite width was presented. In a recent research, it was pointed out that there are great differences between a finite strip and an infinite strip regarding their weight function and the solution of infinite strip can be utilized in the split-tension specimens when the notch size is very small. In the present work, improved version of LEFM formulas for stress intensity factor, crack mouth opening displacement and crack opening displacement profile presented in the recent research work are incorporated. The results of the double-K fracture parameters obtained using revised procedure and the previous work of the authors is compared. The double-K fracture parameters of split-tension cube specimen are also compared with those obtained for standard three point bend test specimen. The input data required for determining double-K fracture parameters for both the specimen geometries for laboratory size specimens are obtained using well known version of the Fictitious Crack Model.

• 한국가스학회지
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• 제5권4호
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• pp.49-55
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• 2001

본 연구에서는 $9\%$ 니켈강재로 제작된 완전 방호식 내부탱크 구조물의 설계 안전성 문제를 유한요소법으로 해석하고자 한다. 내부탱크 구조물에 대한 수치적 해석결과에 의하면 내부탱크에 부착된 톱가더와 스티프너는 내부탱크의 변형율과 응력을 제어하는 중요한 역할을 하고 있다. 내부탱크에 작용하는 여러 하중에서 초저온 액체에 의한 유체정압은 $-162^{\circ}C$의 초저온 온도하중보다 더 큰 영향을 미치고 있음을 알 수 있다. 그러나, 내부탱크에 작용하는 자중량 좌굴하중에 의한 영향은 내부탱크 구조물이 충분한 강도로 이미 설계되어 있으므로 대단히 자게 나타났지만, 특히 톱가더나 스티프너의 역할은 미미한 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1240-1249
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• 2005

Saccharomyces cerevisiae KNU5377 has potential as an industrial strain that can ferment wasted paper for fuel ethanol at $40^{\circ}C$ [15, 16]. To understand the characteristics of the strain, genome-wide expression was performed using DNA microarray technology. We compared the homology of the DNA microarray between genomic DNAs of S. cerevisiae KNU5377 and a control strain, S. cerevisiae S288C. Approximately $97\%$ of the genes in S. cerevisiae KNU5377 were identified with those of the reference strain. YHR053c (CUP1), YLR155c (ASP3), and YDR038c (ENA5) showed lower homology than those of S. cerevisiae S288C. In particular, the differences in the regions of YHR053c and YLR155c were confirmed by Southern hybridization, but did not with that of the region of YDR038c. The expression level of mRNA in S. cerevisiae KNU5377 and S288C was also compared: the 550 ORFs of S. cerevisiae KNU5377 showed more than two-fold higher intensity than those of S. cerevisiae S288C. Among the 550 ORFs, 59 ORFs belonged to the groups of ribosomal proteins and mitochondrial ribosomal proteins, and 200 ORFs belonged to the group of cellular organization. DIP5 and GAP1 were the most highly expressed genes. These results suggest that upregulated DIP5 and GAP 1 might take the place of ASP3 and, additionally, the sensitivity against copper might be contributable to the lowest expression level of copper-binding metallothioneins encoded by CUP 1a (YHR053c) and CUP1b (YHR055c) in S. cerevisiae KNU5377.

• 한국압력기기공학회 논문집
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• 제12권1호
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• pp.62-69
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• 2016

Current guidance considers that uniaxially loaded specimen with a deep crack is used for the determination of the ductile-to-brittle transition temperature. However, reactor pressure vessel is under biaxial loading in real and the existence of deep crack is not probable through periodic in-service-inspection. The elastic stress intensity factor and the elastic-plastic J-integral which were used for crack-tip stress field and fracture mechanics assessment parameters. The difference of the loading condition and crack geometry can significantly influence on these parameters. Thus, a constraint effect caused by differences between standard specimens and a real structure can over/underestimate the fracture toughness, and it affects the results of the structural integrity assessment, consequentially. The present paper investigates the constraint effects by evaluating the master curve $T_0$ reference temperature of PCVN (Pre-cracked Charpy V-Notch) and small scale cruciform specimens which was designed to simulate biaxial loading condition with shallow crack through the fracture toughness tests and 3-dimensional elastic-plastic finite element analyses. Based on the finite element analysis results, the fracture toughness values of a small scale cruciform specimen were estimated, and the geometry-dependent factors of the cruciform specimen considered in the present study were determined. Finally, the transferability of the test results of these specimens was discussed.