• 제목/요약/키워드: plant material

검색결과 2,185건 처리시간 0.031초

Distributed plasticity approach for nonlinear analysis of nuclear power plant equipment: Experimental and numerical studies

  • Tran, Thanh-Tuan;Salman, Kashif;Kim, Dookie
    • Nuclear Engineering and Technology
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    • 제53권9호
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    • pp.3100-3111
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    • 2021
  • Numerical modeling for the safety-related equipment used in a nuclear power plant (i.e., cabinet facilities) plays an essential role in seismic risk assessment. A full finite element model is often time-consuming for nonlinear time history analysis due to its computational modeling complexity. Thus, this study aims to generate a simplified model that can capture the nonlinear behavior of the electrical cabinet. Accordingly, the distributed plasticity approach was utilized to examine the stiffness-degradation effect caused by the local buckling of the structure. The inherent dynamic characteristics of the numerical model were validated against the experimental test. The outcomes indicate that the proposed model can adequately represent the significant behavior of the structure, and it is preferred in practice to perform the nonlinear analysis of the cabinet. Further investigations were carried out to evaluate the seismic behavior of the cabinet under the influence of the constitutive law of material models. Three available models in OpenSees (i.e., linear, bilinear, and Giuffre-Menegotto-Pinto (GMP) model) were considered to provide an enhanced understating of the seismic responses of the cabinet. It was found that the material nonlinearity, which is the function of its smoothness, is the most effective parameter for the structural analysis of the cabinet. Also, it showed that implementing nonlinear models reduces the seismic response of the cabinet considerably in comparison with the linear model.

The Extract of Couroupita guianensis Aubl. Ameliorates Benign Prostatic Hyperplasia In Vitro and In Vivo

  • Kim, Yun Na;Kim, Na-Hyun;Souliya, Onevilay;Uddin, Salah;Lee, Sang Woo;Kim, Soo-Yong;Choi, Sangho;Heo, Jeong-Doo;Jeong, Eun Ju
    • Natural Product Sciences
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    • 제27권4호
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    • pp.274-279
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    • 2021
  • The therapeutic effects of the leaves of Couroupita guianensis, a large tropical tree in the family of Lecythidaceae improving testosterone-induced Benign Prostatic Hyperplasia (BPH) were tested in vitro and in vivo. In BPH rats induced by castration and testosterone treatment, the prostate index was improved in groups administered with the extracts of C. guianensis extracted with 50%-, 100%-ethanol or boiling water, which was comparable with positive control, finasteride. The extract C. guianensis leaves showed significant inhibition on the expressions of type 2 5-alpha reductase (5αR) in RWPE-1 human prostatic epithelial cells, and effectively attenuated the expressions of androgen receptor, type 2 5αR and proliferating cell nuclear antigen in LNCap human prostatic adenocarcinoma cells. The leaves of C. guianensis that exerted evident suppression on BPH-related biomarkers in vitro and improvement of prostate index in vivo has a potential therapeutic use for the treatment of BPH.

쪽제비 싸리의 팔프 이용(利用) (Development of Bastard Indigo (Amorpha fraticosa) Utilization for Pulping)

  • 산림청 임업시험장
    • Journal of the Korean Wood Science and Technology
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    • 제2권3호
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    • pp.39-41
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    • 1974
  • Bastard indigo, prevailing shrub species planted in erosion control work to constitute vegetation, is proved to be usefull for pulp material other than existing usage of green manure or fuel. Pulp made from bastard indigo is good enough for filler pulp though the quality of it is not remarkably excellent. (1) Sorts of paper possible to make from this pulp. Packing paper of medium grade. (general packing paper except heavy packing) (2) Traits of this pulp as for pulp material (A) It is more preferable than annual plants in these respects, ego collection, transport and storage of pulp material, and yield, freeness and chemical consumption of pulp. (B) Annual probable production of pulp material per ha from this plant is higher than that from long-term tree species or similar to that from fast growing species. (C) Its cultivation on eroded area is welcomed and consecutive annual production of material by copice method is also proved possible.

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Rapid and simple method for DNA extraction from plant and algal species suitable for PCR amplification using a chelating resin Chelex 100

  • HwangBo, Kwon;Son, Su-Hyun;Lee, Jong-Suk;Min, Sung-Ran;Ko, Suk-Min;Liu, Jang-R.;Choi, Dong-Su;Jeong, Won-Joong
    • Plant Biotechnology Reports
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    • 제4권1호
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    • pp.49-52
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    • 2010
  • A DNA extraction method using Chelex 100 is widely used for bacteria, Chlamydomonas, and animal cell lines, but only rarely for plant materials due to the need for additional time-consuming and tedious steps. We have modified the Chelex 100 protocol and successfully developed a rapid and simple method of DNA extraction for efficient PCR-based detection of transgenes from a variety of transgenic plant and algal species. Our protocol consists of homogenizing plant tissue with a pestle, boiling the homogenized tissue in a microfuge tube with 5% Chelex 100 for 5 min, and centrifuging the boiled mixture. The supernatant, which is used for PCR analysis, was able to successfully amplify transgenes in transgenic tobacco, tomato, potato, Arabidopsis, rice, strawberry, Spirodela polyrhiza, Chlamydomonas, and Porphyra tenera. The entire DNA extraction procedure requires <15 min and is therefore comparable to that used for bacteria, Chlamydomonas, and animal cell lines.

하수처리장 운영의 최적화를 위한 ASM, PHOENICS의 적용 (Application of ASM and PHOENICS for Optimal Operation of Wastewater Treatment Plant)

  • 김준현;한미덕;한영한
    • 산업기술연구
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    • 제20권A호
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    • pp.73-82
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    • 2000
  • This study was implemented to find an optimal model for wastewater treatment processes using PHOENICS(Parabolic, hyperbolic or Elliptic Numerical Integration Code Series) and ASM(Activated Sludge Model). PHOENICS is a general software based upon the laws of physics and chemistry which govern the motion of fluids, the stresses and strains in solids, heat flow, diffusion, and chemical reaction. The wastewater flow and removal efficiency of particle in two phase system of a grit chamber in wastewater treatment plant were analyzed to inquire the predictive aspect of the operational model. ASM was developed for a biokinetic model based upon material balance in complex activated sludge systems, which can demonstrate dynamic and spatial behavior of biological treatment system. This model was applied to aeration tank and settling chamber in Choonchun city, and the modeling result shows dynamic transport in aeration tank. PHOENCS and ASM could be contributed for the optimal operation of wastewater treatment plant.

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Unrecorded liverwort species from Korean flora III. New data on the distribution of Mannia Opiz (Marchantiophyta)

  • CHOI, Seung Se;BAKALIN, Vadim A.;PARK, Seung Jin;SIM, Sun Hee;HYUN, Chang Woo
    • 식물분류학회지
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    • 제50권2호
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    • pp.227-231
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    • 2020
  • While conducting a floristic study of Korean hepatics, we discovered two unrecorded species, which were collected from wind holes near the Donggang River, Korea. Mannia fragrans (Balb.) Frye & L. Clark and Mannia androgyna (L.) A. Evans are hereby reported for the first time in Korea. M. androgyna is characterized by pale grayish oil bodies in both the aerenchyma and basal tissue, and saccate spores with a conspicuous proximal disc. M. fragrans is characterized by a gynoecial segment with a whitish apical brush of scales, a commonly aromatic smell, and areolate spores with a conspicuous proximal disc. Two unrecorded species are described and illustrated based on Korean material.

American Ginseng: Research Developments, Opportunities, and Challenges

  • Punja, Zamir K.
    • Journal of Ginseng Research
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    • 제35권3호
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    • pp.368-374
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    • 2011
  • American ginseng (Panax quinquefolius L.) is grown in some regions of the USA and Canada and marketed for its health promoting attributes. While cultivation of this plant species has taken place in North America for over 100 years, there are many challenges that need to be addressed. In this article, the current production method used by growers is described and the challenges and opportunities for research on this valuable plant are discussed. These include studies on pharmacological activity, genetic diversity within the species, genetic improvement of currently grown plants, molecular characterization of gene expression, and management of diseases affecting plant productivity. The current research developments in these areas are reviewed and areas requiring further work are summarized. Additional research should shed light on the nature of the bioactive compounds and their clinical effects, and the molecular basis of active ingredient biosynthesis, and provide more uniform genetic material as well as improved plant growth, and potentially reduce losses due to pathogens.

발전소 주 제어실 제어패널의 내진해석 (Seismic Analysis on a Control Panel of (Nuclear) Power Plant)

  • 이흥식;김명구;조종두
    • 한국소음진동공학회논문집
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    • 제15권6호
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    • pp.652-659
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    • 2005
  • In this paper, seismic qualification analysis for the Plant control Panel is carried out to confirm the structural integrity under the seismic conditions represented by required response spectra(RRS). The finite element method(FEM) is used for the analysis and a mode combination method is adopted to obtain a more reliable spectrum analysis results. In addition, the experimental analysis is performed to compare the reliability of the analytical results. The analysis results shows that the plant control panel system is designed to have the dynamic rigidity with no resonance frequency below 33 Hz. The analytically calculated maximum stress of the plant control panel system is $36\%$ of the field strength of material, thus it can be shown that the system has a stable structure for the seismic load.

Development of High Performance Liquid Chromatography for Paclitaxel Purification from Plant Cell Cultures

  • Kim, Jin-Hyun;Choi, Hyung-Kyoon;Hong, Seung-Suh;Lee, Hyun-Soo
    • Journal of Microbiology and Biotechnology
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    • 제11권2호
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    • pp.204-210
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    • 2001
  • Paclitaxel can be produced in high yield and with a high degree of purify from plant cell cultures of Taxus chinensis. The complete purification method was systematically established and described. This method was an efficient procedure for the purification of paclitaxel from crude paclitaxel, consisting or reverse-phase chromatography, followed by a normal-phase chromatography. The two-stage HPLC purification scheme serves as an effective and economical approach for resolving paclitaxel from complex mixtures of taxoids, with high purify (>99%) and low impurities (<0.1%). The process is readily scalable to a pilot plant and eventually to a production environment where multikilogram quantities of material are expected to be produced. The process has been optimized to minimize solvent usage, complexity, and operating costs.

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