• ALGAE
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• v.29 no.3
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• pp.203-215
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• 2014

As global warming continues over the coming century, marine organisms will experience a warmer, more acidic ocean. Although these stressors may behave antagonistically or synergistically and will impact organisms both directly (i.e., physiologically) and indirectly (i.e., through altered species interactions), few studies have examined the complexities of these effects in combination. To address these uncertainties, we examined the independent and combined effects of elevated temperature and $pCO_2$ on the physiology of the adult sporophyte stage of giant kelp, Macrocystis pyrifera, and the grazing of the purple sea urchin Strongylocentrotus purpuratus. While elevating $pCO_2$ alone had no effect on M. pyrifera growth or photosynthetic carbon uptake, elevating temperature alone resulted in a significant reduction in both. However, when M. pyrifera was grown under elevated temperature and $pCO_2$ together, growth and photosynthetic carbon uptake significantly increased relative to ambient conditions, suggesting an interaction of these factors on photosynthetic physiology. S. purpuratus held under future conditions generally exhibited reduced growth, and smaller gonads than urchins held under present-day conditions. However, urchins fed kelp grown under future conditions showed higher growth rates, partially ameliorating this effect. Feeding rates were variable over the course of the experiment, with only the first feeding rate experiment showing significantly lower rates for urchins held under future conditions. Together, these data suggest that M. pyrifera may benefit physiologically from a warmer, more acidic (i.e., higher $pCO_2$) ocean while S. purpuratus will likely be impacted negatively. Given that kelp-urchin interactions can be important to kelp forest structure, changes to either of these populations may have serious consequences for many coastal environments.

• Journal of the Korean Society of Tobacco Science
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• v.29 no.2
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• pp.110-117
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• 2007

In vitro toxicity tests such as cytotoxicity, mutagenicity and genotoxicity assay are useful for evaluating the relative toxicity of smoke or smoke condensates obtained from different cigarette configurations. A major disadvantage of these tests is relatively time-consuming, complicated and expensive. Recently, a cell-free glutathione consumption assay (GCA) as a rapid and simple screening method for the toxicity assessment of smoke has been reported by Cahours et al. (CORESTA, 2006). This study was carried out to assess the GCA application capable of predicting the toxicity of gas/vapor phase (GVP) of cigarette smoke and to identify individual compounds responsible for the glutathione (GSH) consumption in smoke. Each GVPs from 2R4F, standard cigarette, carbon filter cigarette (ExC) and new carbon filter cigarette (ExN), test cigarettes were collected by automatic smoking machine and evaluated the relative toxicity by GCA and neutral red uptake (NRU) assay. Toxic compounds existed in smoke were also chosen, relative toxicities of these compounds were screened by using two methods and compared individually. The overall order of toxicity by GCA was 2R4F > ExC > ExN, which was consistent with the result of Neutral Red Uptake assay. The levels of carbonyl compounds of ExN were lower than those of 2R4F and ExC, indicating that GSH consumption was associated with carbonyl compound yields. A major toxicant under current study is acrolein, which contributed to more than half of the GSH consumption. Collectively, the toxicity of GVP determined by GCA method may be mainly attributed to acrolein.

• Atmosphere
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• v.24 no.3
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• pp.303-315
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• 2014

Terrestrial ecosystem plays the important role as carbon sink in the global carbon cycle. Understanding of interactions of terrestrial carbon cycle with climate is important for better prediction of future climate change. In this paper, terrestrial carbon cycle is investigated by Hadley Centre Global Environmental Model, version 2, Carbon Cycle (HadGEM2-CC) that considers vegetation dynamics and an interactive carbon cycle with climate. The simulation for future projection is based on the three (8.5/4.5/2.6) representative concentration pathways (RCPs) from 2006 to 2100 and compared with historical land carbon uptake from 1979 to 2005. Projected changes in ecological features such as production, respiration, net ecosystem exchange and climate condition show similar pattern in three RCPs, while the response amplitude in each RCPs are different. For all RCP scenarios, temperature and precipitation increase with rising of the atmospheric $CO_2$. Such climate conditions are favorable for vegetation growth and extension, causing future increase of terrestrial carbon uptakes in all RCPs. At the end of 21st century, the global average of gross and net primary productions and respiration increase in all RCPs and terrestrial ecosystem remains as carbon sink. This enhancement of land $CO_2$ uptake is attributed by the vegetated area expansion, increasing LAI, and early onset of growing season. After mid-21st century, temperature rising leads to excessive increase of soil respiration than net primary production and thus the terrestrial carbon uptake begins to fall since that time. Regionally the NEE average value of East-Asia ($90^{\circ}E-140^{\circ}E$, $20^{\circ}N{\sim}60^{\circ}N$) area is bigger than that of the same latitude band. In the end-$21^{st}$ the NEE mean values in East-Asia area are $-2.09PgC\;yr^{-1}$, $-1.12PgC\;yr^{-1}$, $-0.47PgC\;yr^{-1}$ and zonal mean NEEs of the same latitude region are $-1.12PgC\;yr^{-1}$, $-0.55PgC\;yr^{-1}$, $-0.17PgC\;yr^{-1}$ for RCP 8.5, 4.5, 2.6.

• Korean Journal of Materials Research
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• v.26 no.6
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• pp.298-305
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• 2016

In this work, recent progress on graphene/metal oxide composites as advanced materials for $HgCl_2$ and $CO_2$ capture was investigated. Density Functional Theory calculations were used to understand the effects of temperature on the adsorption ability of $HgCl_2$ and water vapor on $CO_2$ adsorption on CaO (001) with reinforced carbon-based nanostructures using B3LYP functional. Understanding the mechanism by which mercury and $CO_2$ adsorb on graphene/CaO (g-CaO) is crucial to the design and fabrication of effective capture technologies. The results obtained from the optimized geometries and frequencies of the proposed cluster site structures predicted that with respect to molecular binding the system possesses unusually large $HgCl_2$ ($0.1-0.4HgCl_2g/g$ sorbent) and $CO_2$ ($0.2-0.6CO_2g/g$ sorbent) uptake capacities. The $HgCl_2$ and $CO_2$ were found to be stable on the surface as a result of the topology and a strong interaction with the g-CaO system; these results strongly suggest the potential of CaO-doped carbon materials for $HgCl_2$ and $CO_2$ capture applications, the functional gives reliable answers compared to available experimental data.

• Membrane Journal
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• v.6 no.2
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• pp.109-116
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• 1996

This work is a fundamental study for applying hybrid process coupling adsorption with microfiltration to waste-water treatment. Phenol was separated by adsorption on powdered activated carbon, adsorbed phenol with activated carbon was separated by microfiltration. As the particle size in suspension increased, filtration resistance decreased, and effect of particle concentration on resistance was less pronounced. The rate of uptake was greatly dependent on the degree of phenol loading. For a smaller amounts of activated carbon, the change of permeate concentration before break point and phenol loading with time were steeper than in the case of large amounts. Permeate concentration before break point decreased with decreasing particle size, this could be due to the increase of outer surface of particle and film mass transfer coefficient.

• Environmental Engineering Research
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• v.22 no.2
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• pp.149-156
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• 2017

Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and $40^{\circ}C$, establishing what temperature favored chromium(III) uptake. At $40^{\circ}C$, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at $70^{\circ}C$ (13.23 g/L $Cr^{3+}$; 42.98 g/L sulfate; and 0.40 g/L NaCl).

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.142-149
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• 2014

This study has compared carbon storages, annual carbon uptakes and annual soil respiration by planting type in Dujeong park, Cheonan city. Four plantations were selected in Dujeong park: Pinus densiflora plantation, Quercus acutissima community, Quercus acutissima-Robinia pseudoacacia plantation, and Robinia pseudoacacia plantation. We investigated each plantations from February 2012 to March 2013. Carbon storage and annual carbon uptake in each plantations were calculated with allometric method (Lee, 2003), and soil respiration was measured by using LI-6400 (LI-COR). Carbon storages in Pinus densiflora plantation, Quercus acutissima community, Quercus acutissima-Robinia pseudoacacia plantation, and Robinia pseudoacacia plantation were $17.36tonCha^{-1}$, $88.63tonCha^{-1}$, $115.38tonCha^{-1}$ and 4$9.88tonCha^{-1}$, and annual carbon uptakes were $1.04tonCha^{-1}yr^{-1}$, $2.12tonCha^{-1}yr^{-1}$, $6.47tonCha^{-1}yr^{-1}$ and $3.67tonCha^{-1}yr^{-1}$, respectively. Average annual carbon uptakes per tree of Pinus densiflora plantation, Quercus acutissima community and Robinia pseudoacacia plantation were $1.81kgC{\cdot}treeyr^{-1}$, $17.86kgC{\cdot}treeyr^{-1}$ and $9.14kgC{\cdot}treeyr^{-1}$ and Quercus acutissima was the greatest. The amounts of carbon released from soil respiration in the same four plantations were $2.20{\mu}molCO_2m^{-2}s^{-1}$, $1.90{\mu}molCO_2m^{-2}s^{-1}$, $2.47{\mu}molCO_2m^{-2}s^{-1}$ and $2.51{\mu}molCO_2m^{-2}s^{-1}$, and annual soil respiration were estimated $6.66tonCha^{-1}yr^{-1}$, $5.33tonCha^{-1}yr^{-1}$, $7.20tonCha^{-1}yr^{-1}$ and $7.25tonCha^{-1}yr^{-1}$, respectively. In this study area, Quercus acutissima-Robinia pseudoacacia plantation has a significant contribution to the role of carbon sink. However, the contribution of Pinus densiflora plantation was evaluated less. The results of this study can be used as the necessary data for tree planting and management in urban park.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.85-92
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• 2006

To evaluate the primary production and nutrient uptake of macrophytes in Lake Paldang, this study investigate the vegetation areas of six dominant aquatic plants including Typha angustifolia, Zizania latifolia, Phragmites australis, Trapa japonica, Nelumbo nucifera and Savinia natans, and contents of carbon, nitrogen and phosphorus of each macrophyte. Total vegetation area of six dominant aquatic plants was 1.37 $km^2$. Among them, Typha angustifolia was the most wide-distributed species which occupied the 46.7% of total vegetation area. Littoral zone of South Han river had the largest vegetation area with 0.458 $km^2$, and North Han river, Kyungan river and confluence area in the order named. The results of the contents of carbon, nitrogen and phosphorus of macrophytes showed that the carbon contents of emergent macrophytes was higher than that of other life-forms. The nitrogen content of Salvinia natans, free-floating macrophyte was highest and that of Typha angustifolia, emergent macrophyte was lowest. The phosphorus content of Trapa japonica showed the highest content of phosphorus among six macrophytes and emergent macrophytes such as Zizania latifolia and Phragmites australis showed lower contents of phosphorus than other life-forms. The annual net primary production of macrophytes in Lake Paldang, 2004, was calculated as 758.4 ton C $yr^{-1}$ and the annual net nitrogen and phosphorus uptake of macrophyte was 16,921 kg $yr^{-1}$ and 1,841.0 kg P $yr^{-1}$ respectively. Comparing the total budget of organic carbon, nitrogen and phosphorus in Lake Paldang, the amount of primary production and nutrient uptake by macrophytes take a small portion in total budget implying macrophytes do not play an important role in budget of matters in river-type lake, Lake Paldang.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.267-276
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• 2001

The downstream reach of the Han River adjoining Seoul in Korea was the upper boundary of an estuary where tidal effect on the flow rate could be exerted. According to the comprehensive river regulation project, the river was channelize dand impounded by two overflow dams, which provided favorable condition for algal growth in this sewage polluted eutrophic reach. In this study primary productivity of phytoplankton was measured in the down reach and the autochthonous and allochthonous organic carbon loadings were estimated. Primary production of phytoplankton measured by C-14 uptake and P-I model method ranged from 140 to $4,890\;mgC\;m^{-2}\;d^{-1}$ (median value $1,865\;mgC\;m^{-2}\;d^{-1}$) showing the level of eutrophic lakes. Phytoplankton density that varied according to water flow rate was highest in spring. Allochthonous organic carbon loading was dominated by sewage input through tributaries in most of days except flood flow period. The average proportion of autochthonous carbon generation by phytoplankton was 40.9%, which is very high proportion for a lotic habitat.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.334-342
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• 2020

BACKGROUND: To quantify carbon exchange at agricultural ecosystems in South Korea, net ecosystem exchange (NEE) at three croplands including a rice paddy, a bean field and an apple orchard was measured on the basis of the eddy covariance technique. METHODS AND RESULTS: NEE of CO2 during the growing season (June to September) averaged over the recent two years (2018-2019) was the highest at rice (-4.49 g C m-2 day-1), followed by the bean (-3.12 g C m-2 day-1) and apple (-0.93 g C m-2 day-1). The diurnal variation of NEE was the highest at the rice, while the seasonal variation of it was the highest at the bean than others. In terms of yearly variation, the rice paddy and the bean field absorbed more CO2 in 2019 compared to 2018, while the apple orchard absorbed less. CONCLUSION: Our results confirmed that these croplands consistently acted as net sinks for CO2 during the growing season because an amount of CO2 uptake from photosynthesis was larger than one of its emissions from respiration. The quantification of net CO2 exchange at agricultural ecosystems may help to better understand the local carbon cycle over various time scales.