• Title/Summary/Keyword: the nature of science

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A Study on Proposal of Landscape Management Improvement on the Quantitative Analysis of National Parks (국립공원(國立公園) 자연경관(自然景觀)의 계량적(計量的) 분석(分析)을 통(通)한 경관관리(景觀管理) 개선방안(改善方案)에 관(關)한 연구)

  • Kim, Sei Cheon
    • Journal of Korean Society of Forest Science
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    • v.80 no.1
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    • pp.32-41
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    • 1991
  • This study is focusted to the national park of Korean typical mountain Chi-ri, its visual resources of forests, and practiced inspectind course by way of hypothesis and tests, to show visual resource management objectively, and that of quantitative basic data. spatial image structure measured by Semantic Differential(S.D.) Scale was shown through factor analysis algorithm for the analyzing psychological amount and examined the flowing out of decisive factor and the objective importance related mutual factors by appling the measurement of visual quality. Also, it has been investigated the differences between the degrees of expectation which is used before and of satisfaction which is used, by appling instrumental expectation theory. And showed patterns of investigation area through factor analyzing algorithm. As a national Park, visual factors that have natural landscape harmonized forest, sky, surface of the water, curious stones and rocks, temples should be escalate their values affirmatively so as to be the scenery of pointed direction and enjoyable, and it is needs the techniques visual resource management and its controlling technique to make artificial structures more intentional planning and systemical setting. Manmade distinctive quality in the spatials that affect complementally or harmonizingly, should be received considering relations between the distifution and joining which in line with various visual presenting massive factors. More than that, it is needed united basic standard to the beauty of arrangements which contain visual continuity considered balance between nature and human work, simplicity of structural types, assimilation, emphasis, unification of different factors and pro rata.

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Effect of soil temperature on the growth and dry matter accumulationof sorghum and corn (토양온도가 수수와 옥수수의 생육 및 건물축적에 미치는 영향)

  • 한흥전;한민수;김정갑
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.6 no.3
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    • pp.179-184
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    • 1986
  • The pot trial was carried out to investigate the influence of soil temperature on the growth and dry matter accumulation in sorghum cv. Pioneer 931 and corn cv. Suweon 19 during their growing season in 1985. Soil temperature maintained with low ($22.3^{\circ}C$), natural($25.9^{\circ}C$) and high temperature($30.5^{\circ}C$) over 24 hour. The results are summarized as follows; 1. Growth of sorghum plants was associated with increasing of soil temperature, while that of corn was reduced under high temperature($30.5^{\circ}C$). The highest plant height of corn was found at natural temperature($25.9^{\circ}C$). Sorghum had higher growth rate than corn plants in all temperature levels. 2. Assimirable leaf areas of the plants were greately increased under high temperature both in sorghum and corn. Sorghum plants maintained almost same levels of leaf area during maturity stage, but those of corn were markedly decreased after mild stage. 3. The highest rates of photosynthesis were found at nature' soil temperature ($25.9^{\circ}C$) both in sorghum($1.619mg/s/m^2$) and corn plants($1.084mg/s/m^2$). Under high temperature($30.5^{\circ}C$) the photosynthesis rates of the plants were decreased to about 1.553 mg and 0.404 mg for sorghum and corn, respectively. Low temperature ($22.3^{\circ}C$) produced only a value of 0.775 mg for sorghum and 0.048 mg for corn. 4. Seasonal dry matter accumulation of sorghum increased in the order of high>natural>low soil temperature, but that of corn increased in the order of natural>high>low soil temperature, respectively.

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A Comparative Study of Biotope Mapping between Korea and Germany (한국과 독일의 비오톱지도화에 대한 비교)

  • Choi, Il-Ki;Ahn, Geun-Young;Lee, Eun-Heui
    • Korean Journal of Environment and Ecology
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    • v.21 no.6
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    • pp.565-575
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    • 2007
  • The purpose of this study is to derive political implications and to look into the establishment of new directions for the biotope mapping across the Korean territory so that such biotope mapping process could be used as a means of actual plan for natural environment preservation through the comparative study of biotope mapping methodology with that of the biotope mapping pioneer-Germany. As for research methodology, this study collected literature and data related to the biotope mapping of Korea and Germany and examined the general characteristics and inclinations about biotope mapping of both country, at a level of the national territory, federal government, provincial government, city and settlement areas. As a result of the examination, first, it was found that Germany drew up a landscape eco-type map and ecological landscape grade map throughout the nation in order to preserve and manage effectively by differential landscape eco-type unit. In contrast, Korea drew up a map on which Degree of Green Naturality and Ecological Nature Status are reflected for natural environment preservation at a nationwide unit. Secondly, the biotope mapping of German was worked centering on natural areas and their corresponding areas at German provincial government level and it drew up a Red-list by each province, while Korea has yet to carry out biotope mapping at a provincial level corresponding to Germany's. Thirdly, the biotope mapping on German cities and settlement areas includes not only big city areas but also medium & small cities and rural areas whereas Korean biotope mapping is conducted mainly centering on urban areas. In conclusion, this study suggests that the biotope mapping including natural areas and anti-natural area, not limited to city areas should be revitalized in order to be a real means of the all territory's balanced natural environment and biotope preservation & management. In addition, for this purpose, this study suggests that research on biotope pattern catalog and biotope red-list applicable to all territory should be preceded.

Synthesis, Spectroscopic, and Biological Studies of Chromium(III), Manganese(II), Iron(III), Cobalt(II), Nickel(II), Copper(II), Ruthenium(III), and Zirconyl(II) Complexes of N1,N2-Bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl)phthalamide (N1,N2-bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl)phthalamide의 크롬(III), 망간(II), 철(III), 코발트(II), 니켈(II), 구리(II), 루테늄(III) 및 산화 지르코늄(II) 착물에 대한 합성과 분광학 및 생물학적 연구)

  • Al-Hakimi, Ahmed N.;Shakdofa, Mohamad M.E.;El-Seidy, Ahemd M.A.;El-Tabl, Abdou S.
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.418-429
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    • 2011
  • Novel chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), ruthenium(III), and zirconyl(II) complexes of $N^1,N^2$-bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl)phthalamide ($H_4L$, 1) have been synthesized and characterized by elemental, physical, and spectral analyses. The spectral data showed that the ligand behaves as either neutral tridentate ligand as in complexes 2-5 with the general formula $[H_4LMX_2(H_2O)]{\cdot}nH_2O$ (M=Cu(II), Ni(II), Co(II), X = Cl or $NO_3$), neutral hexadentate ligand as in complexes 10-12 with the general formula $[H_4LM_2Cl_6]{\cdot}nH_2O$ (M=Fe(III), Cr(III) or Ru(III)), or dibasic hexadentate ligand as in complexes 6-9 with the general formula $[H_2LM_2Cl_2(H_2O)_4]{\cdot}nH_2O$ (M = Cu(II), Ni(II), Co(II) or Mn(II), and 13 with general formula $[H_4L(ZrO)_2Cl_2]{\cdot}8H_2O$. Molar conductance in DMF solution indicated the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complexes 2, 5, and 6 showed $g_{\parallel}$ >g> $g_e$, indicating distorted octahedral structure and the presence of the unpaired electron in the $N^1,N^2$ orbital with significant covalent bond character. For the dimeric copper(II) complex $[H_2LCu_2Cl_2(H_2O)_4]{\cdot}3H_2O$ (6), the distance between the two copper centers was calculated using field zero splitting parameter for the parallel component that was estimated from the ESR spectrum. The antibacterial and antifungal activities of the compounds showed that, some of metal complexes exhibited a greater inhibitory effect than standard drug as tetracycline (bacteria) and Amphotricene B (fungi).

CO2 Methanation Characteristics over Ni Catalyst in a Pressurized Bubbling Fluidized Bed Reactor (가압 기포 유동층 반응기에서의 Ni계 촉매 CO2 메탄화 특성 연구)

  • Son, Seong Hye;Seo, Myung Won;Hwang, Byung Wook;Park, Sung Jin;Kim, Jung Hwan;Lee, Do Yeon;Go, Kang Seok;Jeon, Sang Goo;Yoon, Sung Min;Kim, Yong Ku;Kim, Jae Ho;Ryu, Ho Jeong;Rhee, Young Woo
    • Korean Chemical Engineering Research
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    • v.56 no.6
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    • pp.871-877
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    • 2018
  • Storing the surplus energy from renewable energy resource is one of the challenges related to intermittent and fluctuating nature of renewable energy electricity production. $CO_2$ methanation is well known reaction that as a renewable energy storage system. $CO_2$ methanation requires a catalyst to be active at relatively low temperatures ($250-500^{\circ}C$) and selectivity towards methane. In this study, the catalytic performance test was conducted using a pressurized bubbling fluidized bed reactor (Diameter: 0.025 m and Height: 0.35 m) with $Ni/{\gamma}-Al_2O_3$ (Ni70%, and ${\gamma}-Al_2O_3$30%) catalyst. The range of the reaction conditions were $H_2/CO_2$ mole ratio range of 4.0-6.0, temperature of $300-420^{\circ}C$, pressure of 1-9 bar, and gas velocity ($U_0/U_{mf}$) of 1-5. As the $H_2/CO_2$ mole ratio, temperature and pressure increased, $CO_2$ conversion increases at the experimental temperature range. However, $CO_2$ conversion decreases with increasing gas velocity due to poor mixing characteristics in the fluidized bed. The maximum $CO_2$ conversion of 99.6% was obtained with the operating condition as follows; $H_2/CO_2$ ratio of 5, temperature of $400^{\circ}C$, pressure of 9 bar, and $U_0/U_{mf}$ of 1.4-3.

Exploring Small Group Features of the Social-Construction Process of Scientific Model in a Combustion Class (연소 모델의 사회적 구성과정에서 나타나는 소집단 활동 특징 탐색)

  • Shim, Youngsook;Kim, Chan-Jong;Choe, Seung-Urn;Kim, Heui-Baik;Yoo, Junehee;Park, HyunJu;Kim, HyeYeong;Park, Kyung-Mee;Jang, Shinho
    • Journal of The Korean Association For Science Education
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    • v.35 no.2
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    • pp.217-229
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    • 2015
  • In this study, we explored the development of scientific model through the social-construction process on "combustion." Students were 8th graders from one middle school class. Each student engaged in small group discussions three times and made a group model on combustion. Discourses between peers and teacher were videotaped, audiotaped, and transcribed. The results show that the small groups constructed an initial concept: 'Conditions of combustion', which they then evaluated and revised the initial concept through combustion experiment. Following the discussions, some small groups evaluated their model and made a revised model. Then, the small groups compared various models and constructed a scientific model through consensus within the small group and as a whole class. Finally, students kept revising their model to 'Burning needs oxygen.' This tells us that the social construction process of scientific model made a meaningful role to build scientific model through diverse discussion between the students and their teacher, although they have had some difficult process to reach the final consensus. The data also showed some group features: the members were open to other's ideas. They analyzed the differences between their own ideas from others and revised their model after the whole class discussion. Lastly, they showed the tendency to make a good use of teacher's guidance. This study implies the importance of having social interaction process for students to understand the scientific model and learn the nature of scientific inquiry in class.

Dependence of Sub-Cellular Activities of the Blooming and Harmful Dinoflagellate Cochlodinium Polykrikoides on Temperature (수온에 따른 유해성 Cochlodinium polykrikoides 적조생물의 세포생리 변화)

  • Cho, Eun-Seob
    • Journal of Life Science
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    • v.18 no.9
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    • pp.1194-1201
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    • 2008
  • Water temperature-dependent fluctuations of biochemical and molecular activities in the harmful dinoflagellate, Cochlodinium polykrikoides were studied. In terms of genomic DNA concentration, a similar value of 0.6 was observed at $12^{\circ}C$ and $15^{\circ}C$. However, DNA significantly increased beyond $18^{\circ}C$ (p<0.05), to a maximum of 1.8 at $24^{\circ}C$. DNA concentration significantly decreased to 0.6. The concentrations of RNA and total protein were likely at their highest values of 1.7 and 0.07 ${\mu}g$ $ml^{-1}$ at $24^{\circ}C$, respectively. RNA and total protein concentrations began to increase at $15^{\circ}C$. Oxygen availability between lower and higher temperatures was significantly different and increased from $18^{\circ}C$ according to light intensity, regardless of wavelengths (p<0.05). At $24^{\circ}C$, the highest value of the maximum electron transport rate ($ETR_{max}$), ranging from 537.9 (Ch 1) to 602.5 ${\mu}mol$ electrons $g^{-1}$ Chl ${\alpha}s^{-1}$ (Ch 4), was also apparent. Nitrate reductase (NR) and ATPase activities were at their highest values of 0.11 ${\mu}mol$ $NO_{2}^{-}$ ${\mu}g^{-1}$ Chl ${\alpha}h^{-1}$ and 0.78 pmol 100 $mg^{-1}$ at $24^{\circ}C$, respectively. In an analysis of CHN, the concentration of C and N also significantly increased (p<0.05). Most of the measurements for the cellular activities at $27^{\circ}C$, however, were less than at $24^{\circ}C$. These results suggest that the sub-cellular activities of C. polykrikoides are sensitive to changes in water temperature. It may be desirable to estimate at $18^{\circ}C$ the initiation of the massive blooming development of C. polykrikoides. In nature, it will be very difficult to maintain the massive blooms beyond $24^{\circ}C$ because of a possibly significant decrease in molecular activity of C. polykrikoides.

Conditioned Media of RAW 264.7 Cells Stimulated with Phellinus linteus Extract Regulates the Epithelial-mesenchymal Transition in Prostate Cancer Cells (상황버섯에 의해 활성화된 RAW 264.7 대식세포주 배양액의 인간 전립선암 세포주의 epithelial-mesenchymal transition 조절)

  • Kang, Taewoo;An, Hyun-Hee;Park, Sul-Gi;Yu, Sun-Nyoung;Hwang, You-Lim;Kim, Ji-Won;Ahn, Soon-Cheol
    • Journal of Life Science
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    • v.29 no.8
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    • pp.904-915
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    • 2019
  • Prostate cancer (PCa) is one of the most metastatic tumor. Although hormone therapy or surgical castration is mostly conducted to treat PCa, it has a lot of side effects. Recently, many researchers have been exploring the tumor microenvironment to remedy these circumstances. Immune cells, especially macrophages, are an important composition of the tumor microenvironment. Under normal conditions, macrophages exhibit mild tumoricidal activity against tumors. However, once activated by interferon gamma or lipopolysaccharides, macrophages can kill cancer cells directly or indirectly by secreting cytokines and chemokines. In this study, murine macrophage RAW 264.7 cells were treated with Phellinus linteus extract. To analyze their pro-inflammatory phenotype, we were used several assays such as a real-time polymerase chain reaction, an enzyme-linked immunosorbent and nitric oxide assay. Prostate cancer cells were treated with the RAW 264.7-conditioned media, which was identified as a pro-inflammatory nature, for 48 h, and the expression of epithelial-mesenchymal transition (EMT)-related genes was determined. Not only N-cadherin, Snail, Twist, Slug, and Cadherin 11, which are mechenchymal-related proteins, were decrease, but epithelial marker of E-cadherin was increased. In addition, the mRNA level of vimentin, ccl2, and vegfa were decreased, as the EMT is closely related to the migration and invasion of cancer cells. In conclusion, the RAW 264.7-conditioned media stimulated with P. linteus extract inhibited migration and invasion and regulated the EMT pathway in human prostate cancer cells.

Diversity, Spatial Distribution and Ecological Characteristics of Relict Forest Trees in South Korea (한국 산림유존목의 다양성, 공간 분포 및 생태 특성)

  • CHO, Hyun-Je;Lee, Cheol-Ho;Shin, Joon-Hwan;Bae, Kwan-Ho;Cho, Yong-Chan;Kim, Jun-Soo
    • Journal of Korean Society of Forest Science
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    • v.105 no.4
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    • pp.401-413
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    • 2016
  • Forest resources utilization and variable disturbance history have been affected the rarity and conservation value of forest relict trees, which served as habitat for forest biodiversity, important carbon stock and cultural role include human and natural history in South Korea. This study was conducted to establish the baseline data for forest resources conservation by clarifying species diversity, spatial distribution and ecological characteristics (individual and habitat) of forest relict trees (DBH > 300 cm) based on the data getting from mountain trail, high resolution aerial photos and field professionals and field survey. As results, 54 taxa (18 family 32 genus 48 species 1 subspecies 3 variety and 2 form) as about 22% of tree species in Korea was identified in the field. 837 individuals of forest relict trees were observed and the majority of the trees was in Pinaceae, deciduous Fagaceae and Rosaceae, which families are abundant in population diversity. High elevation area was important to relict trees as mean altitudinal distribution was 1,200 m a.s.l as likely affected by human activity gradients and mid-steep slope and North aspect was important environment for the trees remain. Many individuals exhibited 'damage larger branch' (55.6%) and consequent relatively lower mean canopy coverages (below 80%). Synthetically, present diversity and abundance of relict forest trees in South Korea were the result of complex process among climate variation, local weather and biological factors and the trees of big and old were estimated to important forest biodiversity elements. In the future, clarifying the role and function of relict trees in forest ecosystem, in- and ex- situ programmes for important trees and habitat, and activities for building the background of conservation policy such as "Guideline for identifying and measurement of forest relict trees".

Analysis of research trends for utilization of P-MFC as an energy source for nature-based solutions - Focusing on co-occurring word analysis using VOSviewer - (자연기반해법의 에너지원으로서 P-MFC 활용을 위한 연구경향 분석 - VOSviewer를 활용한 동시 출현단어 분석 중심으로 -)

  • Mi-Li Kwon;Gwon-Soo Bahn
    • Journal of Wetlands Research
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    • v.26 no.1
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    • pp.41-50
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    • 2024
  • Plant Microbial Fuel Cells (P-MFCs) are biomass-based energy technologies that generate electricity from plant and root microbial communities and are suitable for natural fundamental solutions considering sustainable environments. In order to develop P-MFC technology suitable for domestic waterfront space, it is necessary to analyze international research trends first. Therefore, in this study, 700 P-MFC-related research papers were investigated in Web of Science, and the core keywords were derived using VOSviewer, a word analysis program, and the research trends were analyzed. First, P-MFC-related research has been on the rise since 1998, especially since the mid to late 2010s. The number of papers submitted by each country was "China," "U.S." and "India." Since the 2010s, interest in P-MFCs has increased, and the number of publications in the Philippines, Ukraine, and Mexico, which have abundant waterfront space and wetland environments, is increasing. Secondly, from the perspective of research trends in different periods, 1998-2015 mainly carried out microbial fuel cell performance verification research in different environments. The 2016-2020 period focuses on the specific conditions of microbial fuel cell use, the structure of P-MFC and how it develops. From 2021 to 2023, specific research on constraints and efficiency improvement in the development of P-MFC was carried out. The P-MFC-related international research trends identified through this study can be used as useful data for developing technologies suitable for domestic waterfront space in the future. In addition to this study, further research is needed on research trends and levels in subsectors, and in order to develop and revitalize P-MFC technologies in Korea, research on field applicability should be expanded and policies and systems improved.