• Title, Summary, Keyword: carbon dioxide

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Response of Soil CO2 Fluxes to Seasonal Variations in a Grassplot (잔디밭에서 계절 변화에 따른 이산화탄소 플럭스 변동)

  • Kim, Park Sa;Kwon, Byung Hyuk;Kang, Dong Hwan
    • Journal of Environmental Science International
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    • v.23 no.6
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    • pp.1131-1142
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    • 2014
  • In this study, the variations of the carbon dioxide fluxes were investigated with soil temperatures in the grassplot and seasonal variations of carbon dioxide concentrations and fluxes were analysed. Soil temperatures, carbon dioxide concentrations and fluxes were measured on the grassplot in Pukyong National University. Field measurements were carried out 25 times from March in 2010 to March in 2011 with nine points on the grassplot. Seasonal variations of carbon dioxide concentrations and fluxes showed an inverse relation. In summer, carbon dioxide concentrations are lower and carbon dioxide fluxes are higher. In winter, carbon dioxide concentrations are higher and carbon dioxide fluxes are lower. On the grassplot, carbon dioxide emission rate increase when the soil temperature is more than $20^{\circ}C$ and the emission rate decrease when the soil temperatures are less than $10^{\circ}C$. When the accumulated rainfall for five days before measurement day is 20~100 mm, it is showed that the more rainfall, the more carbon dioxide emissions. Carbon dioxide emission rate from the grassplot to the upper atmosphere was increased or decreased by the factors such as soil temperature, growth and wither of grass and rainfall. The results of this study showed that the emission of carbon dioxide in the grassplot is dominantly controlled by seasonal factors (especially soil temperature and rainfall).

Comparative Study on the Ocean Disposal Methods of Carbon Dioxide (이산화탄소 해양 분사방법에 대한 비교연구)

  • Kim Nam-Jin;Kim Chong-Bo
    • Journal of Energy Engineering
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    • v.13 no.4
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    • pp.301-310
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    • 2004
  • Carbon dioxide ocean disposal is one of the promising options to reduce carbon dioxide concentration in the atmosphere. So, in the present study, calculations of the solubility, the surface concentration and the dissolution behavior of carbon dioxide when liquid carbon dioxide is released at 1,000m and 1,500m in depth are performed. The results show that liquid carbon dioxide changes to carbon dioxide bubbles around 500m in depth, and the hydrate acts as a resistant layer for the dissolution of liquid carbon dioxide. Also. the injection of liquid carbon dioxide from a moving ship is more effective than that from a fixed pipeline.

Simulation Model for Dissolution of Liquid $CO_2$ Discharged at Intermediate Depth of Ocean (중층심해에 분사된 액체 이산화탄소 용해 예측모델 개발)

  • 김남진;김종보
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.9
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    • pp.718-726
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    • 2003
  • Carbon dioxide ocean disposal is one of the promising options to reduce carbon dioxide concentration in the atmosphere because the ocean has vast capacity for carbon dioxide sequestration. However, the dissolution rate of liquid carbon dioxide in seawater must be known in advance in order to estimate the amount of carbon dioxide sequestration in the ocean. Therefore, in the present study, calculations of the solubility, the surface concentration and the dissolution behavior of carbon dioxide when liquid carbon dioxide is released at 1,000m and 1,500m in depth are peformed. The results show that the droplet is completely dissolved below 500 m in depth if the carbon dioxide droplet is released both at 1,000m in depth with the initial droplet diameter of 0.011m or less and at 1,500m in depth with the diameter of 0.016 or less. Also, the surface concentration of carbon dioxide droplet with the hydrate film is about 50% of carbon dioxide solubility at 1,500 m in depth and about 60% of carbon dioxide solubility at 1,000 m in depth.

Is there a causal effect between agricultural production and carbon dioxide emissions in Ghana?

  • Owusu, Phebe Asantewaa;Asumadu-Sarkodie, Samuel
    • Environmental Engineering Research
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    • v.22 no.1
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    • pp.40-54
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    • 2017
  • According to FAO, "agricultural sectors are particularly exposed to the effects of climate change and increases climate variability". As a result, the study makes an attempt to answer the question: Is there a causal effect between agricultural production and carbon dioxide emissions in Ghana? By employing a time series data spanning from 1960 to 2015 using the Autoregressive Distributed Lag method. There was evidence of a long-run equilibrium relationship running from copra production, corn production, green coffee production, milled rice production, millet production, palm kernel production and sorghum production to carbon dioxide emissions. The short-run equilibrium relationship shows that, a 1% increase in copra and green coffee production will increase carbon dioxide emissions by 0.22% and 0.03%, a 1% increase in millet and sorghum production will decrease carbon dioxide emissions by 0.13% and 0.11% in the short-run while a 31% of future fluctuations in carbon dioxide emissions are due to shocks in corn production. There was bidirectional causality between milled rice production and carbon dioxide emissions, millet production and carbon dioxide emissions and, sorghum production and carbon dioxide emissions; and a unidirectional causality running from corn production to carbon dioxide emissions and carbon dioxide emissions to palm kernel production.

A Study About Improvement of Experiment of Carbon Dioxide Production on Elementary School Science Textbook (초등학교 과학과 이산화탄소 발생실험의 개선에 관한 연구)

  • 고영신;김세경;이혜경
    • Journal of Korean Elementary Science Education
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    • v.23 no.2
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    • pp.152-158
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    • 2004
  • The purpose of this study was to find the difficulties and problems in the carbon dioxide production experiment and to suggest the device for the improvement. Many students have misconception for the smell of carbon dioxide. I found that the smell of carbon dioxide of producting through the experiment didn't concern with the quantity of calcium carbonate. I certificated that the smell of carbon dioxide was related with the concentration of hydrochloric acid. I built two trap applicaing suction in the gas production device to exclude fully the smell of carbon dioxide. So the smell of carbon dioxide was not present by passing the two trap. To find the ideal experimental conditions I perform the experiment step by step. As the result enough carbon dioxide to use for the property experiment was collected under the condition that is 60 mL of 3 molarity hydrochloric acid and 30 g calcium carbonate. I certificated to mesuring flowing quantity of carbon dioxide using the flow meter of carbon dioxide. In the improvement experiment of the property of carbon dioxide, I proposed the experiment device regarding as spreading of the gas and children's interest. To improve the problem of gas production experiment, I proposed the gas certification device using a thread.

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Dissolution Characteristics of Liquid $CO_2$ Injected at the Intermediate Depth of the Ocean (중층심해에 분사된 액체 이산화탄소의 용해특성)

  • Kim, N.J.;Lee, J.Y.;Seo, T.B.;Kim, C.B.
    • Solar Energy
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    • v.20 no.2
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    • pp.75-84
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    • 2000
  • Global wanning induced by greenhouse gases such as carbon dioxide is a serious problem for mankind. Carbon dioxide ocean disposal is one of the promising options to reduce carbon dioxide concentration in the atmosphere because the ocean has vast capacity for carbon dioxide sequestration. However, the dissolution rate of liquid carbon dioxide in seawater must be known in advance in order to estimate the amount of carbon dioxide sequestration in the ocean. Therefore, the solubility, the surface concentration, the droplet size and other factors of liquid carbon dioxide at various depths are calculated. The results show that liquid carbon dioxide changes to carbon dioxide bubble around 500 m in depth, and the droplet is completely dissolved below 500 m in depth if carbon dioxide droplet is released both at 1000 m in depth with the initial droplet diameter of 0.011 m or less and at 1500 m in depth with the diameter of 0.015 m or less. In addition, the hydrate film acts as a resistant layer for the dissolution of liquid carbon dioxide. The surface concentration of carbon dioxide droplet with the hydrate film is about 50% at 1500 m in depth and about 60% at 1000 m in depth of the carbon dioxide solubility. Also, the ambient carbon dioxide concentration in the plume is an another crucial parameter for complete dissolution at the intermediate ocean depth, and the injection of liquid carbon dioxide from a moving ship is more effective than that from a fixed pipeline.

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A Policy Suggestion for the Adaptation of Climate Change in Korea (우리나라의 기후변화 대응방안에 관한 정책 제언)

  • Shin, Im Chul;Kim, Yeongsin
    • Atmosphere
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    • v.19 no.1
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    • pp.53-66
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    • 2009
  • The purpose of this study is to describe the roles of carbon dioxide in the climate change, and carbon dioxide reduction policies in some countries. In addition, ways to cope with climate change in Korea are also discussed. Currently, global temperatures are rising due to the carbon dioxide produced by human beings. Global temperatures will rise approximately $6^{\circ}C$ until 2100 if we emit carbon dioxide at a present rate. Temperature rise will affect the terrestrial and oceanic resources, and ultimately influence the socio-economic structures including political stability. Most of the carbon dioxide comes from fossil fuels. Therefore, it is urgent to reduce the use of energy, which comes from fossil fuels. Solving the climate change due to the increases in carbon dioxide is a global problem. Korea should participate in the international community and cooperate with each other in order to reduce the carbon dioxide concentration. No policy was announced for the reduction of carbon dioxide so far. Korea should make a policy for the reduction of carbon dioxide in a specific year compared to that of certain standard year such as 1990 or 2005. Making policy should be based on the scientific result of the amount of carbon dioxide emitted and absorbed. Germanwatch announced the Climate Change Performance Index (CCPI) in order to evaluate an effort to reduce the carbon dioxide for 56 countries which emits 90 % of global carbon dioxide. Ranking for Korea is 51 among 56 countries. This clearly indicates that the appropriate carbon dioxide reduction has not been exercised yet in Korea. Researchers have a moral responsibility to provide updated new ideas and knowledges regarding climate change. Politicians should have a sharp insight to judge the ideas provided by researchers. People need an ethics to reduce the carbon dioxide in every day's life. Scientific research should not be influenced by stress caused by external budget and negative impact of capitalism. Science should be based on the pure curiosity.

Effect of Carbonization Temperature on Carbon Dioxide Adsorption Behaviors of mesoporous carbon (중기공 탄소의 탄화온도에 따른 이산화탄소 흡착 거동)

  • Jang, Dong-Il;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • pp.221.1-221.1
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    • 2011
  • In this study, we prepared the nitrogen-containing carbon spheres with mesopore processed by a facile polymerization-induced colloid aggregation method including carbonization in order to investigate the characterization and the effect on their carbon dioxide adsorption behaviors. The carbonization temperature was varied in the range of $600^{\circ}C$ to $900^{\circ}C$. The nitrogen contents of the mesoporous carbon sphere were characterized using XPS. The carbon dioxide adsorption capacities of the prepared mesoporous carbon sphere were determined by the amounts of carbon dioxide adsorptions at 298 K and 1.0 atm. The results showed that the prepared mesoporous carbons were highly effective for the carbon dioxide adsorption due to the increasing the affinity of the basic functionalities of adsorbent surface to acidic carbon dioxide. Maximum adsorption capacities of carbon dioxide at $25^{\circ}C$ were achieved up to 106 mg/g.

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Characteristics of Carbon Dioxide Destruction with a Plasma Torch and Effect of Additives (플라즈마 토치를 이용한 이산화탄소 분해특성과 첨가제의 영향)

  • Kim, Seong Cheon;Jeon, Jeong Hyeon;Chun, Young Nam
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.3
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    • pp.287-296
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    • 2013
  • To decompose carbon dioxide, which is a representative greenhouse gas, a plasma torch was designed and manufactured. To examine the characteristics of carbon dioxide decomposition via plasma discharge, a case wherein pure carbon dioxide was supplied and a case wherein methane and/or $TiCl_4$ were injected as additives were investigated and compared. The carbon dioxide and methane conversion rate, energy decomposition efficiency, produced gas concentration, carbon monoxide and hydrogen selectivity, carbon-black and $TiO_2$ were also investigated. The maximum carbon dioxide conversion rate was 28.9% when pure carbon dioxide was supplied; 44.6% when $TiCl_4$ was injected as am additive; and 100% percent when methane was injected as an additive. Therefore, this could be explained that the methane injection showed the highest carbon dioxide decomposition. Furthermore, the carbon-black and $TiO_2$ were compared with each commercial materials through XRD and SEM. It was found that the carbon-black that was produced in this study is similar for commercial materials. It was found that the $TiO_2$ that was produced in this study is suitable for photocatalyst and pigment because it has mixed anataze and rutile.

Antimicrobial Effect of Carbon Dioxide on Microorganisms (이산화탄소의 항균 효과)

  • 홍석인;변유량
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.6
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    • pp.1258-1267
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    • 1997
  • Corbon dioxide id effective for extending the shelf-life of perishable foods by retarding microbial growth. The overall effect of carbon dioxide is to increase both the lag phase and generation time of microorganisms. However, the role of carbon dioxide in affecting the growth and metabolism of any given microorganisms is not clear yet, although its inhibitory effect is generally found at moderate to high concentrations. Systematic studies of the effects of carbon dioxide on microorganisms are therefore warranted. It is also necessary to understand the role of carbon dioxide in the preservation of foods as well as the control by carbon dioxide of fermentations of biotechnological importance. In this review, the antimicrobial effect of carbon dioxide on microorganisms is investigated in terms of its gas and solution properties, inhibition of microbial growth and specific metabolic processes, perturbation of membrane structure.

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