• Title/Summary/Keyword: natural medium

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Isotropic Compression Behavior of Lawsonite Under High-pressure Conditions (로소나이트(Lawsonite)의 압력에 따른 등방성 압축거동 연구)

  • Im, Junhyuck;Lee, Yongjae
    • Economic and Environmental Geology
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    • v.49 no.1
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    • pp.23-30
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    • 2016
  • Powder samples of natural lawsonite (Ca-lawsonite, $CaAl_2Si_2O_7(OH)_2{\cdot}H_2O$) was studied structurally up to 8 GPa at room temperature using monochromatic synchrotron X-ray powder diffraction and a diamond anvil cell (DAC) with a methanol : ethanol : water (16 : 3 : 1 by volume) mixture solution as a penetrating pressure transmitting medium (PTM). Upon pressure increase, lawsonite does not show any apparent pressure induced expansion (PIE) or phase transition. Pressure-volume data were fitted to a second-order Birch-Murnaghan equation of state using a fixed pressure derivative of 4 leading to a bulk modulus ($B_0$) of 146(6) GPa. This compression is further characterized to be isotropic with calculated linear compressibilities of ${\beta}^a=0.0022GPa^{-1}$, ${\beta}^b=0.0024GPa^{-1}$, and ${\beta}^c=0.0020GPa^{-1}$.

A Study on the Engineering Properties of Alluvial Clays (충적점토의 토질공학적 제성상에 관한 연구)

  • 류기송;김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.20 no.4
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    • pp.4805-4811
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    • 1978
  • This paper deals with the correlations between the results of the physical property tests and the mechanical property tests for estimating the mechanical indexes by the physical property test results. The soil samples were taken at changweon area, Gyeon-gsangnam-do, where the structures would be placed on the alluvial clay foundation. The outcomes of the study are as follows: 1. Judging from casagrande's plasticity chart, it is considered that the almost all soil samples belong to inorganic silty clay with medium plasticity (clay 14∼62%, silt 36∼73%, sand 1∼29%). The specific gravities are between 2.61 and 2.72, the wet unit weights 1.53g/㎤ and 1.93g/㎤, the liquid limits 28% and 51%, the plastic limits 15% and 31%, the plastic indexes 7% and 27%, the natural moisture contents 33% and 64%. 2. The unconfined compression strengths are between 0.07kg/$\textrm{cm}^2$ and 0.77kg/$\textrm{cm}^2$, the cohesions 0.04kg/$\textrm{cm}^2$ and 0.37kg/$\textrm{cm}^2$, the internal friction angles 0$^{\circ}$ and 9$^{\circ}$. 3. The consolidation tests show that the initial void ratios are between 0.68 and 1.68, the precompression loads 0.27kg/$\textrm{cm}^2$ and 1.15kg/$\textrm{cm}^2$, the compression indexes 0.12 and 0.59. 4. The correlations between the results of the physical property tests and the mechanical property tests for the soil samples are presented as follows: rt=0.011 (203-wn), Cc=0.025 (LL-27.2), Cc=0.46 (e0-0.58), Cc=0.013 (wn-23.2), C=0.021+qu/2.08, qu=2.268rt-3.635

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Formation of Fruiting Body of Omphalotus japonicus by Sawdust Cultivation (톱밥재배에 의한 화경버섯의 자실체 발생)

  • Ka, Kang-Hyeon;Park, Hyun;Hur, Tae-Chul;Bak, Won-Chull
    • The Korean Journal of Mycology
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    • v.38 no.1
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    • pp.80-82
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    • 2010
  • Omphalotus japonicus is known to as a poisonous mushroom in East Asia, but Illudin S, bioluminescent compound, has been recently reported for an anticancer effect. The fungus is quite rare in natural condition in Korea. Therefore, we tried to cultivate in the mushroom on the sawdust cultivation to provide sufficient amount of mushroom for pharmaceutical study for the future. The mushroom could be harvested from all sawdust media used in this study, and the sawdust of Pinus densiflora was considered to be the best for mushroom cultivation with considering mushroom productivity and cultivation period. The mushroom was produced 43~80 g fresh weight per 600 g sawdust medium in average, and could be harvested one to three times during cultivation period.

Deterioration Diagnosis and Conservation Treatment of the Three-storied Stone Pagoda in Seungansaji Temple Site, Hamyang, Korea (함양 승안사지 삼층석탑의 풍화훼손도 진단과 보존처리)

  • Lee, Myeong Seong;Choi, Hee Su;Kim, Ji Young;Lee, Chan Hee;Kim, Sun Duk
    • 보존과학연구
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    • s.32
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    • pp.99-112
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    • 2011
  • The three-storied stone pagoda located in Seungansaji temple site consists mainly of medium to fine-grained biotite granite and granitic gneiss, and partly macrocrystalline gneiss, muscovite gneiss and gabbro. The surface of the stone pagoda is extensively colonized by lichen and moss due to surrounding trees and lawns, and severly deteriorated. Therefore, a comprehensive deterioration diagnosis has been carried out and conservation treatment was conducted in this study. For the conservation treatment, dry cleaning is performed throughout all the surface of the pagoda for naturally grown lichen and biological contaminants using a soft brush and wooden knife. Crustose lichen strongly adhere to the surface was removed by wet cleaning using distilled water. Also, protective railings were reinstalled to an appropriate height with taking the distance from the stone pagoda into account. Finally, the ground around the stone pagoda was repaired with clay sand, and dike was installed with a natural gradient to facilitate water drainage.

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A Yeast MRE3/REC114 Gene is Essential for Normal Cell Growth and Meiotic Recombination

  • Leem, Sun-Hee
    • Journal of Microbiology
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    • v.37 no.4
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    • pp.248-255
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    • 1999
  • We have analyzed the MRE3/REC114 gene of Saccharomyces cerevisiae, previously detected in isolation of mutants defective in meiotic recombination. We cloned the MRE3/REC114 gene by complementation of the meiotic recombination defect and it has been mapped to chormosome XIII. The DNA sequence analysis revealed that the MRE3 gene is identical to the REC114 gene. The upstream region of the MRE3/REC114 gene contains a T_4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. Coincidentally, northern blot analysis indicated that the three sizes of MRE3/REC114 transcripts, 3.4, 1.4 and 1.2 kb, are induced in meiosis. A less abundant transcript of 1.4 kb is detected in both mitotic and meiotic cells, suggesting that it is needed in mitosis as well as meiosis. To examine the role of the MRE3/REC114 gene, we constructed mre3 disruption mutants. Strains carrying an insertion or null deletion of the MRE3/REC114 gene showed slow growth in nutrient medium and the doubling time of these cells increased approximately by 2-fond compared to the wild-type strain. Moreover, the deletion mutant (${\delta}$mre3) displayed no meiotically induced recombination and no viable spores. The mre3/rec114 spore lethality can be suppressed by spo13, a mutation that causes cells to bypass reductional division. The double-stranded breaks (DSBs) which are involved in initiation of meiotic recombination were not detected in the analysis of meiotic chromosomal DNA from the mre3/rec114 disruptant. From these results we suggest that the MRE3/REC114 gene product is essential in normal growth and in early meiotic stages involved in meiotic recombination.

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Antioxidative and Anti-inflammatory Effect of Ethanol Extract from Duchesnea chrysantha (사매 에탄올 추출물의 항산화 및 항염증 효과)

  • Lee, Deok-Jae;Jeon, In-Hwa;Kim, Hyeon-Soo;Cho, Il-Young;Jang, Seon-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.1
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    • pp.59-66
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    • 2012
  • Oxidative stress has been implicated in cutaneous damage in various inflammatory skin diseases, including atopic dermatitis. The present study was undertaken to investigate the antioxidative and anti-inflammatory activities of the extract of Duchesnea chrysantha (DCE). DEC was prepared by extracting with 80% ethanol. Total flavonoids and polyphenols were measured by a colorimetric assay. The free radical scavenging activity of the extract was analyzed by the DPPH (1,1-diphenyl-2-picryl hydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and Griess reagent assay. An oxidative product of nitric oxide (NO), was measured in the culture medium by the Griess reaction. The level of prostaglandin $E_2$ ($PGE_2$) was measured by enzyme-linked immunosorbent assay. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were measured by Western blot analysis. Total flavonoid and polyphenol contents of DCE were included $24.73{\pm}0.45$ and $178.77{\pm}2.65$, respectively. DCE significantly increased electron donating ability (DPPH), nitrite scavenging (NO) and ABTS reducing activity in dose dependant. We investigated the anti-inflammatory effects of DCE on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. DCE significantly suppressed NO and prdstaglandin $E_2$ ($PGE_2$) in dose dependant. Furthermore, the levels of iNOS and COX-2 protein expressions were markedly suppressed by the treatment with DCE in a dose dependent manner. These results suggest that DEC may has value as natural product with its high quality functional components, antioxidative and anti-inflammatory activities.

Inhibition of Arachidonate Release From Rat Peritoneal Macrophage by Biflavonoids

  • Lee, Song-Jin;Son, Kun-Ho;Chang, Hyeun-Wook;Kang, Sam-Sik;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
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    • v.20 no.6
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    • pp.533-538
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    • 1997
  • Biflavonoid is one of unique classes of naturally-occurring bioflavonoid. Previously, certain biflavonoids were found to possess the inhibitory effects on phospholipase $A_2$ activity and lymphocytes $ proliferation^1$ suggesting their anti-inflammatory/immunoregulatory potential. In this study, effects of several biflavonoids on arachidonic acid release from rat peritoneal macrophages were investigated, because arachidonic acid released from the activated macrophages is one of the indices of inflammatory conditions. When resident peritoneal macrophages labeled with $[^{3}H]$arachidonic acid were activated by phorbol 12-myristate 13-acetate(PMA) or calcium ionophore, A23187, radioactivity released in the medium was increased approximately 4.1-7.3 fold after 120 min incubation compared to the spontaneous release in the control incubation. In this condition, biflavonoids (10 uM) such as ochnaflavone, ginkgetin and isoginkgetin, showed inhibition of arachidonate release from macrophages activated by PMA (32.5-40.0% inhibition) or A23187 (21.7-41.7% inhibition). Amentoflavone showed protection only against PMA-induced arachidonate release, while apigenin, a monomer of these biflavonoids, did not show the significant inhibition up to 10 uM. Staurosporin (1 uM), a protein kinase C inhibitor, showed an inhibitory effect only against PMA-induced arachidonate release (96.8% inhibition). Inhibition of arachidonate release from the activated macrophages may contribute to an anti-inflammatory potential of biflavonoids in vivo.

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Simulation of Sustainable Co-evolving Predator-Prey System Controlled by Neural Network

  • Lee, Taewoo;Kim, Sookyun;Shim, Yoonsik
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.9
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    • pp.27-35
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    • 2021
  • Artificial life is used in various fields of applied science by evaluating natural life-related systems, their processes, and evolution. Research has been actively conducted to evolve physical body design and behavioral control strategies for the dynamic activities of these artificial life forms. However, since co-evolution of shapes and neural networks is difficult, artificial life with optimized movements has only one movement in one form and most do not consider the environmental conditions around it. In this paper, artificial life that co-evolve bodies and neural networks using predator-prey models have environmental adaptive movements. The predator-prey hierarchy is then extended to the top-level predator, medium predator, prey three stages to determine the stability of the simulation according to initial population density and correlate between body evolution and population dynamics.

Comparative analysis of internal flow characteristics of LBE-cooled fast reactor main coolant pump with different structures under reverse rotation accident conditions

  • Lu, Yonggang;Wang, Xiuli;Fu, Qiang;Zhao, Yuanyuan;Zhu, Rongsheng
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2207-2220
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    • 2021
  • Lead alloy is used as coolant in Lead-based cooled Fast Reactor (LFR). The natural characteristics of lead alloy are combined with the simple structural design of LFR. This constitutes the inherent safety characteristics of LFR. The main work of this paper is to take the main coolant pump (MCP) in the lead-cooled fast reactor (LFR) as the research object, and to study the flow pattern distribution of the internal flow field under the reverse rotation pump condition, the reverse rotation positive-flow braking condition and the reverse rotation negative-flow braking condition. In this paper, the double-outlet volute type and the space guide vane are selected as the potential designs of the CLEAR-I MCP. In this paper, the CFD method is used to study the potential reverse accident of the MCP. It is found that the highest flow velocity in the impeller appears at the impeller outlet, and the Q-H curves of the two design programs basically coincide. The space guide vane type MCP has better hydraulic performance under the reverse rotation positive-flow condition, the Q-H curves of the two designs gradually separate with increasing flow rate, and the maximum flow velocity inside the space guide vane type MCP is obviously lower than that of the double-outlet volute type. For the reverse rotation test of MCP, only the condition of the forward rotating pump of the main coolant pump is tested and verified. For the simulation of the MCP in LBE medium, it proved that the turbulence model and basic settings selected in the simulation are reliable.

Regeneration of plants from alginate-encapsulated axenic nodal segments of Paederia foetida L. - A medicinally important and vulnerable plant species

  • Behera, Biswaranjan;Behera, Shashikanta;Shasmita, Shasmita;Mohapatra, Debasish;Barik, Durga Prasad;Naik, Soumendra Kumar
    • Journal of Plant Biotechnology
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    • v.48 no.4
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    • pp.255-263
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    • 2021
  • Paederia foetida L. is an important medicinal plant that has been used for the treatment of various gastrointestinal related ailments by different tribal communities in India. This plant is also known for its use as a food. Due to overexploitation, P. foetida has been classified as a vulnerable plant in some states of India. The propagation of P. foetida by conventional methods is easy but very slow. Synthetic seed technology offers incredible potential for in vitro propagation of threatened and commercially valuable plants, and can also facilitate the storage and exchange of axenic plant material between laboratories. However, synthetic seed production for P. foetida has not yet been reported. Thus, to the best of our knowledge, the present study is the first attempt to produce synthetic seeds of P. foetida by calcium alginate encapsulation of in vitro regenerated axenic nodal segments. Sodium alginate (3%) and CaCl2 (100 mM) were found to be the optimal materials for the preparation of ideal synthetic seeds, both in terms of morphology and germination ability. The synthetic seeds showed the best germination (formation of both shoot as well as root; 83.3%) on ½ MS medium augmented with 0.5 mg/L indole-3-acetic acid. The plantlets obtained from these synthetic seeds could be successfully acclimatized under field conditions. We also studied the storage of these synthetic seeds at low temperature and their subsequent sprouting/germination. The seeds showed a germination rate of 63.3% even after 21 days of storage at 4 ℃; thus, they could be useful for transfer and exchange of P. foetida germplasm.