• The Korean Journal of Ecology
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• v.25 no.3 s.107
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• pp.139-144
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• 2002

Most of army depots contaminated with co-contaminants, 2,4,6-trinitrotoluene(TNT) and heavy metals. In phytoremediation for the TNT, heavy metals may inhibit mineralization, transformation and sequestration of TNT by the plant. We studied effect of cadmium on TNT degradation and transformation by Abutilion avicennae in hydroponic cultures. When cultured in 20 mgTNT/L and 1.3 mgCd/L, the plant displayed phytotoxicities; reduction of leaf fresh, leaf roil, chlorosis, leaf loss and fresh weight loss. Phytotoxicity was severer in the combined contaminants than in single contaminant. Because A. avicennae uptake just a little cadmium, 1.3 mgCd/L included in the TNT medium did not influece significantly TNT transformation, translocation and distribution by A. avicennae. Therefore, the soil solution containing cadmium would not affect TNT degradation by Abutilion avicennae in Army depots polluted with TNT.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.350-353
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• 2009

As a result of human industrial development, carbon dioxide ($CO_2$) is currently accumulating in the atmosphere and dissolving into the oceans. Sequestration into the deep sea has been proposed as a possible solution to this increasing atmospheric $CO_2$, although the impact of such a program on marine ecosystems is unknown. We examined the effects of increased $CO_2$ levels on the growth of the olive flounder, Paralichthys olivaceus. Juvenile olive flounder 40 days post hatching were exposed to two levels of $CO_2$ (3.60-7.55 and 4.05-11.46 kPa) in running seawater for 26 days. During the exposure period, the pH and $CO_2$ levels of the water were measured, and the numbers of dead individuals were counted in each aquarium. Following the exposure period, the total lengths (mm) and body weights (mg) of the juvenile fish were measured. Both $CO_2$ treatments significantly increased fish mortality compared to controls ($19.87\pm4.53%$ vs. 7.14% and $75.96\pm1.36%$ vs. 7.14% for high and low doses, respectively). After the high $CO_2$ treatment, total length ($14.98\pm6.58$ mm vs. $19.52\pm1.83$ mm) and body weight ($28.92\pm13.85$ mg vs. $67.35\pm18.32$ mg) of the exposed flounder were reduced compared to the control fish; however, no significant differences in these values were observed after the low $CO_2$ dose. These results suggested that $CO_2$ exposure inhibits growth in the juvenile stage and that $CO_2$-enriched seawater is toxic in the early life stages of olive flounder.

• Advances in environmental research
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• v.6 no.2
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• pp.127-137
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• 2017

Cotton is the major fiber crop in Pakistan that accounts for 2% of total national gross domestic product (GDP). After picking of cotton, the dry stalks are major organic waste that has no fate except burning to cook food in villages. Present research focuses use of cotton stalks as feedstock for biochar production, its characterization and effects on soil characteristics. Dry cotton stalks collected from agricultural field of Bahauddin Zakariya University, Multan, Pakistan were combusted under anaerobic conditions at $450^{\circ}C$. The physicochemical analysis of biochar and cotton stalks show higher values of % total carbon, phosphorus and potassium concentrations in biochar as compared to cotton stalks. The concentration of nitrogen was decreased in biochar. Similarly biochar had greater values of fixed carbon that suggest its role for carbon sequestration and as a soil amendment. The fourier transformation infrared spectroscopic spectra (FTIR) of cotton stalks and biochar exposed more acidic groups in biochar as compared to cotton stalks. The newly developed functional groups in biochar have vital role in increasing surface properties, cation exchange capacity, and water holding capacity, and are responsible for heavy metal remediation in contaminated soil. In a further test, results show increase in the water holding capacity and nutrient retention by a sandy soil amended with biochar. It is concluded that cotton stalks can be effectively used to prepare biochar.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.645-651
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• 2008

In this study, the new solubility data at high pressure condition applicable to pre-combustion $CO_2$ capture system were found. Experiments were conducted within the temperature range of $40{\sim}80^{\circ}C$ while increasing the pressure from 0 to 50 bar. The effect of MDEA (N-methyldiethanolamine) concentration was studied by varying the concentration from 30 to 50 wt%. In order to improve the absorption rate of MDEA, piperazine was added in ranging of 5~10 wt% into the MDEA solution as a activator. From this experiment, the equilibrium partial pressure was increased with increasing MDEA concentration in absorbent and reaction temperature. Also absorption rate was increased with increasing the reaction temperature. It was noted that the mixture of piperazine and MDEA aqueous solution showed faster absorption rate by 2.5 times than only the MDEA aqueous solution with 40 wt% cencentration at initial reaction stage and also increased absorption capacity by 16%.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.95-105
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• 2009

Land Use Changes (LUCs) have effects on greenhouse gas emissions and carbon stocks in soil and vegetation. Therefore, predictions for LUC are very important for achieving quantitative targets of $CO_2$ reduction rates. Some research exists on carbon fluxes and carbon cycles to estimate carbon stocks in terrestrial ecosystems in Korea. However, these researches have limitations in terms of helping us understand future potential reductions of $CO_2$ that reflect the influence of LUC. The aim of this study is to analyze the reduction levels of $CO_2$ emissions while considering LUC scenarios that effect carbon fluxes for LCS basic study in the year 2030. In this study, a common approach to model the effects of LUC on carbon stocks is the use of CA-Markov technical process with LUC patterns in the past. Potential reduction of $CO_2$ is calculated by change of land use that contains different soil organic carbon, each land use type, and biomass in vegetation. An IPCC analytical method of natural carbon sink and coefficient results from previous study in Korea is used as a calculation method for potential reduction of $CO_2$. As a result, 12,419 KtC will be reduced annually, which is 8.3% percent of 2005 $CO_2$ emissions in Korea. This will result in 3,226 hundred million won of economic efficiency. In conclusion, conservation of natural carbon sinks is necessary even if the amount of potential reduction change is little.

• New & Renewable Energy
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• v.8 no.2
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• pp.24-32
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• 2012

Natural gas hydrates have a high potential as the 21st century new energy resource, because it have a large amount of deposits in many deep-water and permafrost regions of the world widely. Natural gas hydrate is formed by physical binding between water molecule and gas mainly composed of methane, which is captured in the cavities of water molecules under the specific temperature and pressure. $1m^3$ methane hydrate can be decomposed to the methane gas of $172m^3$ and water of $0.8m^3$ at standard condition. Therefore, there are a lot of practical applications such as separation processes, natural gas storage transportation and carbon dioxide sequestration. For the industrial utilization of methane hydrate, it is very important to rapidly manufacture hydrate. However, when methane hydrate is artificially formed, its reaction time may be too long and the gas consumption in water becomes relatively low, because the reaction rate between water and gas is low. So in this study, hydrate formation was experimented by adding natural zeolite and Synthetic zeolite 5A in distilled water, respectively. The results show that when the Synthetic zeolite 5A of 0.01 wt% was, the amount of gas consumed during the formation of methane hydrate was higher than that in the natural zeolite. Also, the natural zeolite and Synthetic zeolite 5A decreased the hydrate formation time to a greater extent than the distilled water at the same subcooling temperature.

• Journal of Chest Surgery
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• v.23 no.4
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• pp.698-706
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• 1990

Congenital Cystic Lung Disease is a spectrum of closed related anomalies that arise during an early stage of embryonic lung bud maturation-namely bronchogenic cyst, congenital lobar emphysema, pulmonary sequestration and congenital cystic adenomatoid malformation. And they show similar surgical strategies. So they are called as the term bronchopulmonary-foregut malformations, firstly proposed by Gerle[1968]. From Aug. 1979 to Aug 1989, 47 patients were operated upon on Dept. of Thoracic & Cardiovascular Surgery at the CUMC. There were 21 females and 26 males ranging in age from age of 21 day to age of 56 year [15 cases under 15 years old]. 30 patients had bronchogenic cysts - 23 of intrapulmonary type, 7 of mediastinal type in location. Affected lobes and locations were as follows: 11 in upper lobe, 3 in middle lobe, 11 in lower lobe and anterosuperior, middle, and posterior mediastinal type were 3, 2, 2 respectively. There were 9 pulmonary sequestrations[all intralobar type] with the distribution of 5 in right lower lobe and 4 in left lower lobe. And associated anomalies were presented with arterial supply originating from thoracic aorta[8 cases], abdominal aorta[1 case] and with venous drainage into azygos vein[1 case]. They all were operated upon lower lobectomy [8 case], pneumonectomy[1 case] in case of pulmonary hypoplasia Congenital lobar emphysema and congenital cystic adenomatoid malformation had 4 cases respectively. Their affected lobes were as follows: the former were 3 in upper lobes, 1 in middle lobe and the latter were 3 in upper lobe, 1 in lower lobe. They were treated with lobectomy and segmentectomy. Diagnosis was aided by chest X - ray, bronchography, aortography, DSA and CT scan, They all were confirmed by pathologic exams. There were no hospital death but few minor morbidities such as, atelectasis-pneumonia[2], wound infection[2], prolonged chest tube placement[2]. We experienced surgical treatments of 47 cases for 10 years and reported them with literature review.

• The Korean Journal of Ecology
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• v.25 no.2
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• pp.69-74
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• 2002

Most of army depots contaminated with co-contaminants. 2,4,6-trinitrotoluene(TNT) and heavy metais. In phytormediation for the TNT, heavy metals may inhibit mineralization, transformation and sequestration of TNT by the plant. W studied effect of cadmium on TNT degradation and transformation by Abutilion avicenneae in hydroponic cultures. When cultured in 20 ㎎TNT/L and 1.3 ㎎Cd/L. the plant displayed phytotoxicities; reduction of leaf fresh, leaf roll, chlorosis, leaf loss and fresh weight loss. Phytotoxicity was severer in the combined contaminnts than in single contaminant. Because A. avicennae uptake just a little cadmium, 1.3 ㎎Cd/L induded in the TNT medium did not influece significanfly TNT transformation, translocation and distrivution by A. Therefore, the soil solution containing cadmium would not affect TNT degradation by Abutilion avicennae in Amy depots polluted with TNT.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.631-639
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• 1996

Electrosurgical technique have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Electrosurgery is a surgical procedure performed on soft tissue utilizing controlled high frequency electricaI(radio-frequency) currents in the range of 1,500,000 to 7,500,000 cyclesper second. The radio-frequency energy used in electrosurgery is able to cut and coagulate tissue because it focuses the energy at the small, active electrode. Advantages of electrosurgery for soft-tissue management during dental procedures include improved hemostasis, ease of tissue modification, improved visibility and so on, but adverse healing responses-including necrosis of soft tissue and sequestration of alveolar bone-have been reported. The present report provides examples of treatment of soft tissue and pulp tissue of primary teeth by electrosurgery. The results are as follows; 1. Electrosurgical techniques can be used for various procedures in pedodontics. 2. Electrosurgical procedures provide improved hemostasis and visibility in the operating field, which enable to remove, reshape, and contour soft tissues easily. 3. In pulpotomy technique, it was difficult to expect the variable pulpal response based on the degree of heat accumulation and the conditions of pulp tissues. Therefore, electrosurgical pulpotomy could not be considered as a method superior to formocresol pulpotomy. 4. A greater degree of dexterity and experiences in manipulation of the electrode is required compared with the conventional scalpel surgery.

• Asian Journal of Atmospheric Environment
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• v.12 no.1
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• pp.1-16
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• 2018

Ground-level ozone ($O_3$) can be a menace for vegetation, especially in Asia where $O_3$ levels have been dramatically increased over the past decades. To ensure food security and maintain forest ecosystem services, such as nutrient cycling, carbon sequestration and functional diversity of soil biota, in the over-populated Asia, environmental standards are needed. To set proper standards, dose-response relationships should be established from which critical levels are derived. The predictor of the response in the dose-response relationship is an $O_3$ metric that indicates the dose level to which the plant has been exposed. This study aimed to review the relevant scientific literature and summarize the $O_3$ metrics used worldwide to provide insights for Asia. A variety of $O_3$ metrics have been used, for which we discuss their strengths and weaknesses. The most widely used metrics are based only on $O_3$ levels. Such metrics have been adopted by several regulatory agencies in the global. However, they are biologically irrelevant because they ignore the plant physiological capacity. Adopting AOT40 ($O_3$ mixing ratios Accumulated Over the Threshold of $40nmol\;mol^{-1}$) as the default index for setting critical levels in Asia would be a poor policy with severe consequences at national and Pan-Asian level. Asian studies should focus on flux-based $O_3$ metrics to provide relevant bases for developing proper standards. However, given the technical requirements in calculating flux-based $O_3$ metrics, which can be an important limitation in developing countries, no-threshold cumulative exposure indices like AOT0 should always accompany flux-based indices.