• Title/Summary/Keyword: CRH

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Laminate composites behavior under quasi-static and high velocity perforation

  • Yeganeh, E. Mehrabani;Liaghat, G.H.;Pol, M.H.
    • Steel and Composite Structures
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    • v.22 no.4
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    • pp.777-796
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    • 2016
  • In this paper, the behavior of woven E-glass fabric composite laminate was experimentally investigated under quasi-static indentation and high velocity impact by flat-ended, hemispherical, conical (cone angle of $37^{\circ}$ and $90^{\circ}$) and ogival (CRH of 1.5 and 2.5) cylindrical perforators. Moreover, the results are compared in order to explore the possibility of extending quasi-static indentation test results to high velocity impact test results in different characteristics such as perforation mechanisms, performance of perforators, energy absorption, friction force, etc. The effects of perforator nose shape, nose length and nose-shank connection shapes were investigated. The results showed that the quasi-static indentation test has a great ability to predict the high velocity impact behavior of the composite laminates especially in several characteristics such as perforation mechanisms, perforator performance. In both experiments, the highest performance occurs for 2.5 CRH projectile and the lowest is related to blunt projectiles. The results show that sharp perforators indicate lower values of dynamic enhancement factor and the flat-ended perforator represents the maximum dynamic enhancement factor among other perforators. Moreover, damage propagation far more occurred in high velocity impact tests then quasi-static tests. The highest damage area is mostly observed in ballistic limit of each projectile which projectile deviation strongly increases this area.

Changes in Soil Physical Properties of Peatmoss Containing Root Media as Influenced by Container Size and Packing Density (용기 크기와 충전밀도 차이에 따른 피트모스 혼합상토의 물리성 변화)

  • Park, Eun Young;Choi, Jong Myung;Lee, Dong Hoon
    • Horticultural Science & Technology
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    • v.31 no.5
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    • pp.558-564
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    • 2013
  • The objective of this research was to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. Three root media were formulated by blending peatmoss (PM) with expanded rice hull (PM + ERH, 8:2, v/v), carbonized rice hull (PM + CRH, 6:4) and ground and aged pine bark (PM + GAPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120, and 130%, then the changes in total porosity (TP), container capacity (CC), and air-filled porosity (AFP) were measured. The TP decreased significantly as the packing amount of three root media were elevated in all sizes of container. The TP did not show significant differences among the root media in small sizes of containers, but showed significant differences when sizes of containers became larger. As packing amount of three root media were elevated, the CCs in all sizes of containers were decreased. The PM + CRH had the lowest CC among three root media in containers smaller than 8.5 cm, but had the highest CC in those larger than 10.5 cm. These results indicated that the decreases in CC were influenced by the sizes of containers as well as kinds of root media. The elevation of packing amount in three root media diminished significantly the AFP. The AFP in PM + GAPB medium was two times as high as those of PM + ERH or PM + CRH when equal packing densities were applied in all sizes of containers. As the container sizes became larger in three root media, the extents in decreasing of CC were distinct than those of AFP. Above results indicate that elevation in packing amount of three root media decreased significantly the TP, CC and AFP, but these were influenced differently by sizes of containers and kinds of root media. The results would be useful for expectation in the changes of physical properties in various sizes of containers filled with peatmoss based root media.

Effect of Plug Cell Volume and Medium Composition on Rooting and Growth of Lateral Shoot Cuttings of Tomato Plant (플러그 셀의 크기와 배지(培地) 조성이 토마토 삽목묘(揷木苗)의 발근(發根)과 생육(生育)에 미치는 영향(影響))

  • Yang, Seung-Koo;Cho, Myeong-Su;Choe, Kyeong-Ju;Kim, Wol-Soo
    • Horticultural Science & Technology
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    • v.19 no.3
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    • pp.325-328
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    • 2001
  • This experiment was conducted to investigate the effect of plug cell volume and medium on rooting and growth of lateral shoot cuttings of a few tomato cultivars. Plug cell volume was varied from 23 to 300 mL or control (cutting bed) and media used were carbonized rice hull (CRH), CRH+perlite, CRH+peatmoss and perlite+peatmoss. Nursery plants were able to be transplanted in 15 to 20 days after lateral shoots cutting in tomato. In volume of cutting media, the pots of 23 to 300 mL were proper, although root growth was gradually limited in decreased media volume. Rooting and growth was not influenced by plug tray cell medium of 120 mL or more. Cherry tomato Pepe (c.v.) showed 100% rooting and better growth, while in Momotaro (c.v.) rooting was 90%. There were 100% rooting and no considerable changes grown in all media tested of cutting plug tray volume of 30 mL.

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Study of Anti-inflammatory Activity of 7 Herbal Prescription Effective for Sleep Disorders and Atopic Dermatitis (수면 장애 및 아토피피부염에 효과적인 7 가지 한약 처방의 항염증 활성 연구)

  • Choi, Min-Jin;Nguyen, Ly Thi Huong;Jeong, Jeonghwa;Park, Minyoung;Yoon, Joohee;Lee, Byung-Wook;Yang, In-Jun;Shin, Heung-Mook
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.35 no.2
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    • pp.56-63
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    • 2021
  • This study was conducted to find a candidate prescription with anti-inflammatory efficacy of 7 herbal prescriptions known to be effective in atopic dermatitis and sleep disorders in Korean medicine. The anti-inflammatory of the 7 herbal prescriptions extracts were evaluated by ELISA assay and Western blot assay. 7 herbal prescriptions, Seongyutang(SU), Danseontoetang(DST), Sotosajahwan(ST), Jisiljagyagsan(JJ), Seokchangpo(SCP), Wiryeongseon(WLS), Gogojohwan(GGJ) 30 % EtoH extract was used for in vitro experiments. In TNF-α + IFN-γ(TI) stimulated HaCaT cells, all 7 herbal prescriptions reduced TARC and MDC production, and JJ strongly reduced TARC and MDC production at 100 ㎍/ml concentration. SCP strongly reduced MDC production at 10 ㎍/ml and 100 ㎍/ml concentration. In addition, in substance P(SP)/CRH stimulated HMC-1 cells, JJ strongly inhibited VEGF production at both 10 and 100 ㎍/ml concentrations. In LPS/CRH stimulated Raw264.7 cells, all 7 herbal prescriptions significantly inhibited TNF-α. PMA + Ionomycin(PI)/CRH stimulated EL4 cells, SU significantly reduced IL-4 production at both concentrations of 10 and 100 ㎍/ml. WLS significantly reduced IL-17 production at both concentrations of 10 and 100㎍/ml. This suggests that 7 herbal prescriptions have anti-inflammatory effects by reducing inflammatory cytokines in keratinocytes, mast cells and macrophages caused by inflammation. Therefore, it is expected that 7 herbal prescriptions that are effective for sleep disorders and atopic dermatitis can be used as therapeutic materials for sleep disorders and diseases associated with atopic dermatitis.

An Overview of Psychoneuroimmunology (정신신경면역학 개관)

  • Kim, Do Hoon
    • Korean Journal of Biological Psychiatry
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    • v.15 no.3
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    • pp.147-151
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    • 2008
  • This review briefly summarizes the relevant knowledge of psychoneuroimmunological basis for neuroimmunology, with particular emphasis on bidirectional neural-immune interactions. The immune system and the nervous system maintain extensive communication, including hardwiring of sympathetic and parasympathetic nerves to lymphoid organs. Immune system is modulated by various neurotransmitters such as acetylcholine, norepinephrine, substance P and histamine. Neuroendocrine hormones such as corticotrophin-releasing hormone(CRH) or substance P regulate cytokine balance. The immune system modulates brain activity including sleep and body temperature. Recent studies have revealed that psychological factors which influence immunity and immune-related disease may modulate brain-to -immune interaction. But, we still await the scientific research and evidences to prove whether or how behavioral or treatment intervention of stress can influence the development, progress or prevention of a specific disease.

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3D-QSAR Studies of 8-Substituted-2-aryl-5-alkylaminoquinolines as Corticotropin-releasing Factor-1 Receptor Antagonists

  • Nagarajan, Santhosh Kumar;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.8 no.3
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    • pp.176-183
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    • 2015
  • Corticotropin-releasing actor receptors (CRFRs) activates the hypothalamic pituitary adrenal axis, one of the 2 parts of the fight or flight response to stress. Increased CRH production has is associated with Alzheimer's disease and major depression and hypoglycemia. In this study, we report the important structural and chemical parameters for CRFR inhibitors using the derivatives of 8-substituted-2-aryl-5-alkylaminoquinolines. A 3D QSAR study, Comparative molecular field analysis (CoMFA) was performed. The best predictions were obtained for the best CoMFA model with a $q^2$ of 0.607 with 6 components and $r^2$ of 0.991. The statistical parameters from the generated CoMFA models indicated that the data are well fitted and have high predictive ability. The contour map resulted from the CoMFA models might be helpful in the future designing of novel and more potent CRFR derivatives.

Mechanics of missile penetration into geo-materials

  • Siddiqui, N.A.;Abbas, H.
    • Structural Engineering and Mechanics
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    • v.13 no.6
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    • pp.639-652
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    • 2002
  • The present study aims to improve an existing model for the prediction of deceleration time history, penetration depth and forces on ogive and conical nose shaped missiles under normal impact into geo-material targets. The actual ogive nose shaped missile has been considered in the analysis and the results thus obtained have been compared with the existing model and significant improvements are found. A close proximity in the results has also been observed with the experimental values. The results of ogive nose shaped missile have also been compared with equivalent conical nose shaped missile. Variation of radial stresses along nose length and radial direction has been studied. Effect of CRH on missile penetrating performance has been investigated.

Comparative Molecular Similarity Indices Analysis (CoMSIA) of 8-substituted-2-aryl-5-alkylaminoquinolines as Corticotropin-releasing factor-1 Receptor Antagonists

  • Nagarajan, Santhosh Kumar;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.9 no.4
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    • pp.241-248
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    • 2016
  • Corticotropin-releasing factor receptors (CRFRs) activate the hypothalamic-pituitary-adrenal axis, which is an integral part of the fight or flight response to stress. Increase in CRH level is observed in Alzheimer's disease and major depression and hypoglycemia. Here, we report on the relevant physicochemical parameters required for the CRFR inhibitors. Comparative molecular similarity indices analysis (CoMSIA) was performed with the derivatives of 8-substituted-2-aryl-5-alkylaminoquinolinesas CRFR inhibitors. The best predictions were obtained for the best CoMSIA model with a $q^2$ of 0.576 with 6 components and $r^2$ of 0.977. The statistical parameters from the generated CoMSIA models indicated that the data are well fitted and have high predictive ability. CoMSIA contour maps could be useful in the designing of more potent and novel CRFR derivatives.

Stress response: Physiological and Behavioral Aspects (스트레스반응의 생 행동적 접근)

  • Kim, Keum-Soon
    • Perspectives in Nursing Science
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    • v.2 no.1
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    • pp.61-75
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    • 2005
  • Physical and psychological events can produce stress response in various degrees. Stress affects many aspects of physiology including both brain and peripheral elements which is represented as hypothalamus-pituitary-adrenal axis. Brain elements consist of corticotropin-releasing hormone(CRH), locus ceruleus(LC)-norepinephrine(NE)/autonomic system. Peripheral elements include pituitary-adrenal axis and the autonomic nervous system, which coordinate the stress response. Current trend of the stress researches is emphasizing the mechanisms of the stress response which is adaptive or become maladaptive. This review introduces 1) the concepts of stress, 2) physiological and behavioral aspects of stress responses, 3) the consequences of stress response, 4) the measurements of stress and 5) stress management for those interested in stress research.

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Steady-State Harmonic Domain Matrix-Based Modeling of Four-Quadrant EMU Line Converter

  • Wang, Hui;Wu, Mingli;Agelidis, Vassilios G.;Song, Kejian
    • Journal of Power Electronics
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    • v.14 no.3
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    • pp.572-579
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    • 2014
  • As a non-linear time variant system, the four-quadrant line converter of an electric multiple unit (EMU) was expressed by linear time periodic functions near an operating point and modeled by a steady-state harmonic domain matrix. The components were then combined according to the circuit connection and relations of the feedback control loops to form a complete converter model. The proposed modeling method allows the study of the amplitude of harmonic impedances to explore harmonic coupling. Moreover, the proposed method helps provide a better design for the converter controllers, as well as solves the problem in coordination operation between the EMUs and the AC supply. On-site data from an actual $CRH_2$ high-speed train were used to validate the modeling principles presented in the paper.