• 제목/요약/키워드: growth reduction

검색결과 2,764건 처리시간 0.028초

Assessment of environmental impacts of LID technologies on vegetation

  • Choi, Hyeseon;Hong, Jungsun;Geronimo, F.K.F.;Kim, Lee-Hyung
    • Membrane and Water Treatment
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    • 제10권1호
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    • pp.39-44
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    • 2019
  • LID facilities do not consider environmental factors, and due to inappropriate vegetation planting causing degradation in efficiency due to plant damage and difficulty in maintenance. Therefore, in this study, assessment of impact environmental factor by seasonal variation of chlorophyll and growth of vegetation planted in LID technologies and change of pollutant reduction were conducted. In the case of B-SJ and B-RI, growth rate decreased after summer (August), and B-MG showed steady growth until autumn (September). Chlorophyll was found to increase during spring season while it decreased during autumn season. The chlorophyll concentration was found to affect the plant growth pattern. TN reduction efficiency was highest with greater than 80% efficiency in summer, and it was analyzed that plants were identified as the main factor affecting the seasonal reduction efficiency of TN. Also, temperature and relative humidity were analyzed to affect plant growth, activity and pollutant removal efficiency. Plant type and growth pattern are considered as factors to be considered in selection of appropriate plant types in LID technologies.

수소환원공정에 의한 니켈 미분말의 합성에 미치는 마그네슘 스테아린산의 첨가 영향 (Effect of magnesium stearate addition on synthesis of fine nickel powders by hydrogen reduction process)

  • 이윤복;이상근;박희찬;이미혜;김광호
    • 한국결정성장학회지
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    • 제13권3호
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    • pp.117-121
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    • 2003
  • 염화 니켈과 마그네슘 스테아린산 혼합 분말로부터 수소환원 공정에 의하여 니켈 분말을 제조하고 반응온도 및 마그네슘스테아린산의 첨가에 따른 분말의 특성을 검토하였다. 마그네슘 스테아린산을 함유한 경우 과도한 입자 성장의 억제로 인하여 입경 감소 효과가 있었다. 마그네슘 스테아린산의 함유량이 증가함에 따라 이에 따른 액상량의 증가로 인하여 입경 감소와 입자들간의 응집 정도에도 영향을 주었다.

Effect of Electrochemical Redox Reaction on Growth and Metabolism of Saccharomyces cerevisiae as an Environmental Factor

  • Na, Byung-Kwan;Hwang, Tae-Sik;Lee, Sung-Hun;Ahn, Dae-Hee;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제17권3호
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    • pp.445-453
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    • 2007
  • The effect of an electrochemically generated oxidation-reduction potential and electric pulse on ethanol production and growth of Saccharomyces cerevisiae ATCC 26603 was experimented and compared with effects of electron mediators (neutral red, benzyl viologen, and thionine), chemical oxidants (hydrogen peroxide and hypochlorite), chemical reductants (sulfite and nitrite), oxygen, and hydrogen. The oxidation (anodic) and reduction (cathodic) potential and electric pulse activated ethanol production and growth, and changed the total soluble protein pattern of the test strain. Neutral red electrochemically reduced activated ethanol production and growth of the test strain, but benzyl viologen and thionine did not. Nitrite inhibited ethanol production but did not influence growth of the test strain. Hydrogen peroxide, hypochlorite, and sulfite did not influence ethanol production and growth of the test strain. Hydrogen and oxygen also did not influence the growth and ethanol production. It shows that the test strain may perceive electrochemically generated oxidation-reduction potential and electric pulse as an environmental factor.

The Effect of Economic Growth and Urbanization on Poverty Reduction in Vietnam

  • NGUYEN, Huyen Thi Thanh;NGUYEN, Chau Van;NGUYEN, Cong Van
    • The Journal of Asian Finance, Economics and Business
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    • 제7권7호
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    • pp.229-239
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    • 2020
  • This article aims to measure the impact of economic growth and urbanization on poverty reduction in Vietnam, and verify whether economic growth and urbanization will help reduce poverty rates. Data for this study are tabular data related to growth, urbanization and poverty at the provincial level for the period of nine years, from 2006 to 2014 provided by the Vietnam General Statistics Office and the Vietnam General Department of Customs. The level of economic growth and urbanization mentioned in the study is reflected in such indicators as GDP value, exports value, imports value, urbanization rate and employment rate. The authors used logistic regression models with fixed-effects and logistic regression models with random effects. With 5% confidence level tested by the Chi-Square test of Hausman trial with the fixed-effect model, research results show that: (1) factors with significant negative impact on the poverty rate include imports value, urbanization rate and, employment rate; (2) factors that do not affect the poverty rate include exports value and GDP value. Based on the research results, this study proposes a number of policy recommendations to help promote economic growth, to sustain the urbanization process, and to contribute directly and positively to poverty reduction in Vietnam.

성장과 분배 및 빈곤의 관계 연구 (A Survey of Relationship between Growth, Distribution and Poverty)

  • 유경준
    • KDI Journal of Economic Policy
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    • 제28권2호
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    • pp.199-237
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    • 2006
  • 지금까지 밝혀진 실증적인 성장과 분배의 관계는, 성장은 평균적으로 분배중립적으로 분배에 특정한 형태의 영향을 미친다는 실증적 증거는 없으며, 높은 부의 불평등도는 성장을 저해한다는 점이다. 한편 성장과 분배는 모두 빈곤에 이론적 실증적으로 영향을 미친다. 따라서 빈곤의 감소를 위해서는 성장과 분배의 정책적 조합이 필요하므로 성장과 분배의 이분법은 잘못된 것이다. 현 시점에서 한국이 성장과 분배의 조화를 통해 절대빈곤을 감소시키기 위해서는 세계은행에서 권장하는 빈곤감소적 성장을 추구할 필요가 있다. 한편, 절대적 빈곤과 절대적 불평등도는 음의 상관관계에 있기 때문에 양극화의 논의가 절대적 불평등도를 감소시키자는 정책으로 진행되어서는 절대빈곤의 감소를 기대하기 어려울 것이다.

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Salicylic Acid Counteracts Aluminum Stress-induced Growth and Biomass Yield Reduction in Medicago sativa L.

  • Rahman, Md. Atikur;Lee, Sang-Hoon;Song, Yowook;Ji, Hee Jung;Kim, Ki-Yong;Choi, Gi Jun;Lee, Ki-Won
    • 한국초지조사료학회지
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    • 제39권3호
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    • pp.153-157
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    • 2019
  • Salicylic acid (SA) is an essential plant growth regulator that functions as a signaling molecule in plants. The purpose of this study was to clarify how the exogenous application of SA counteracts aluminum stress-induced growth and biomass yield reduction in alfalfa exposed to aluminum (Al) stress. Two-week-old alfalfa seedlings were exposed to a combination of $AlCl_3$ ($0{\mu}M$, $50{\mu}M$ and $100{\mu}M$, respectively) and SA (0.1 mM) for 72 hours. We observed, Al stress-induced plant growth inhibition and forage yield reduction are Al stress-dependent manner. A significant reduction of plant height (42.0-52.9%), leaf relative water content (13.0-21.4%), root length (35.4-48.7%), shoot fresh weight (31.2-25.9%), root fresh weight (15.4-23.3%), shoot dry weight (12.7-22.2%), roots dry weight (47.3-53.5%), were observed in alfalfa. In contrast, SA alleviated the Al-stress and enhanced growth and biomass yield in alfalfa. This study provides useful information concerning the role of SA that counteracts aluminum stress-induced growth and yield reduction in alfalfa.

열탄화법을 사용한 탄화규소 나노와이어의 성장 (Growth of SiC Nanowire Using Carbothermal Reduction Method)

  • 노대호;김재수;변동진;양재웅;김나리
    • 한국재료학회지
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    • 제13권10호
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    • pp.677-682
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    • 2003
  • SiC nanowires were synthesized by carbothermal reduction using metal catalysts. Synthesized nanowires had mean diameters of 30∼50 nm and several $\mu\textrm{m}$ length. The kind of catalysts affects form of SiC nanowire because of difference of growth mechanisms. These differences were made by catalyst's physical property and relative activities to the source gas. Ni acted a conventional catalyst of VLS growth mechanism. But, Case of Fe, SiC nanowire was grown by stable VLS growth mechanism without relation of growth conditions. SiC nanowire was grown by two step growth model using Cr catalyst. Conversion ratios to the SiC nanowire were increased with growth conditions. Case of Cr, conversion ratio was about 45% that was higher than other catalyst used. This high conversion ratio was obtained by the addition VS growth to radial direction on the as-grown nanowires.

Growth and characterization of lead bromide: application to mercurous bromide

  • Kim, Geug-Tae
    • 한국결정성장학회지
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    • 제14권2호
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    • pp.50-57
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    • 2004
  • Mercurous Bromide ($Hg_2Br_2$) crystals hold promise for many acousto-optic and opto-electronic applications. This material is prepared in closed ampoules by the physical vapor transport (PVT) growth method. We investigate the effects of solutal convection on the crystal growth rate in a horizontal configuration for diffusive-convection conditions and purely diffusion conditions achievable in a low gravity environment. Our results show that the growth rate is decreased by a factor of one-fourth with a ten reduction of gravitational acceleration near y = 2.0 cm. For 0.1 $g_O$ the growth rate pattern exhibits relatively flat which is intimately related to diffusion-dominated processes. The growth rate nonuniformity is regardless of aspect ratio across the interfacial positions from 0 to 1.5. Also, the effect of a factor of the ten reduction in the gravitational acceleration is same to both Ar = 5 and 2. The enlargement in the molecular weight of B from 50 to 500 by a factor 4 causes a decrease in the maximum growth rate by the same factor, indicative of the effect of solutal gradients.

Inhibition of Aquatic Vascular Plants on Phytoplankton Growth II. Algal Growth Experiments with Water and Plant Extracts from Submerged Macrophytes

  • Nam, Sung-Jin;Park, Sang-Kyu
    • 생태와환경
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    • 제40권4호
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    • pp.520-526
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    • 2007
  • To select submerged macrophytes to suppress growth of Microcystis aeruginosa through releasing allelochemicals, we conducted growth experiments with water from patches of submerged macrophytes and with aqueous extracts of those submerged macrophytes. In the first experiment, growth rates of M. aeruginosa decreased as biomass of Myriophyllum spicatum and Hydrilla verticillata increased. In the second experiment, M. aeruginosa showed approximately 50% growth reduction with extracts from M. spicatum and 24% reduction with extracts from Ottelia alismoides. Both M. aeruginosa growth experiments with water and plant extracts suggest that M. spicatum would be the best candidate to reduce M. aeruginosa growth.

The Influence of Light Reduction on the Growth of Microcystis aeruginosa and Variation of Environmental and Chemical Parameters in Large-scale Cultivation System

  • Yang, Taehui;Cho, Ja-young;Kang, Ha-jin;Lee, Chang Soo;Kim, Eui-jin
    • 생태와환경
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    • 제53권4호
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    • pp.336-343
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    • 2020
  • Large-scale cultivation of Microcystis aeruginosa in different light conditions was conducted for verifying the cell growth in a greenhouse system. Environmental and chemical parameters of the large-scale culture medium were measured for analyzing the interaction between M. aeruginosa and its symbiotic bacteria. During cultivation, a difference in cell growth pattern was observed between control (natural light) and light-limited groups (reduction of blue, green, and blue/green light, respectively). Comparing the control group, the light reduced groups showed slow and delayed cell growth through the cultivation period. Also, there is differences in the consuming pattern of total nitrogen and total phosphorus which indicated that the possibility of interaction between M. aeruginosa and symbiotic bacteria.