Mathematical models have been developed to evaluate methane emission from landfills. The Intergovernmental Panel on Climate Change (IPCC) and the US Environmental Protection Agency (USEPA) have provided first-order decay (FOD) models to estimate methane emission from landfills. The methane generation potential (L0) and the methane generation rate constant (k) are the two primary parameters in the FOD model. A major challenge in landfill gas modeling is estimating these parameters. The IPCC recommended that every country should develop country-specific emission factors appropriate for its circumstances and characteristics. The k value represents the rate constant associated with waste decomposition. In general, there are two different approaches for estimating a k value for a landfill. One uses actual field data in comparison with modeled data. However, this approach is limited by the spatial and temporal characteristics of landfill. Another approach is to collect samples of landfilled waste and then measure their biodegradability of waste as a function of waste age. As biodegradability is a surrogate for landfilling age, lower biodegradability would be expected in order samples. The objective of this study was to determine a k value using an anaerobic test (GB21). To achieve this objective, the GB21 which is used in Germany was conducted to estimate biodegradability of waste samples, and k value was determined based on FOD equation. Waste samples were collected at a landfill located in A City, Korea. The landfill is a valley-type landfill. It received municipal solid waste from 1990 to 2010. Food and paper wastes were the major fractions, constituting about 62.9% of the total amount disposed. However, the Ministry of Environment in Korea banned direct landfilling of food wastes in 2005, since then, food waste has no longer been disposed into landfills. In this study, the landfill site was separated into four areas based on landfilling age, and four samples were collected from each area. Cumulative biogas production for the waste excavated from the landfill varied from 6.9 to 35.8 Nl/kg-Dry Matter. Cumulative biogas production for landfilling age of 1 year was 35.8 Nl/kg-DM and it decreased to 6.9 Nl/kg-DM after 14 years. The k value obtained from this study was 0.156 yr-1 and was higher than the default k prescribed by the IPCC, which is 0.09 yr-1 in boreal and temperate climates. The higher k values obtained in this study can be explained by the high proportion of food waste disposed into the studied landfill. The default k values of rapidly degrading wastes including food waste and sludge are 0.185 yr-1. In addition a higher k value will result in predictions of more methane generation in the early years after waste burial, resulting in higher estimates of uncollected methane in greenhouse gas inventories. This work contributes to understanding decomposition rate of landfilled waste by examining biodegradability determination and providing k value for landfill.

Pollutants generated by the biodegradation of livestock carcasses have the potential for contamination of the environment. Hence, livestock mortalities burial has been banned in the EU. In spite of the hazard, research on the biodegradation of livestock carcasses is lacking. In this study, five lysimeters were used to evaluate the enhanced biodegradation of organic materials in livestock mortalities burial. Lysimeter 1(control), lysimeter 2(grinding of livestock carcass), lysimeter 3(anaerobic microorganisms), lysimeter 4(Corynebacterium glutamicum in anaerobic condition) and lysimeter 5(Corynebacterium glutamicum in aerobic condition) were operated with temperature control. The degradation efficiencies of livestock carcass in the lysimeters were evaluated based on total organic carbon balance. The degradation efficiencies of ground livestock carcass were 1.9 times more than those of livestock carcass without grinding. In anaerobic condition, anaerobic microorganisms were more effective compared with Corynebacterium glutamicum on the biodegradation of livestock carcasses. However, the degradation efficiencies with Corynebacterium glutamicum in aerobic condition were significantly influenced on the biodegradation of livestock carcasses. Even if it would be helpful to degrade the livestock carcass in aerobic condition in terms of stabilization, potential risks on the environment by odor and bioaerosol must be solved.

Lead leached out from the metal lead-sinker attached to fishing nets or contained in ropes are likely to cause the environmental contamination, consequently, resulting in ecotoxicity. However, it is very difficult to find out the data on the disposal reality of fishing nets, lead-containing form of/in fishing net and its content. In previous studies, we presented the containing form of lead and the lead concentration leached out by the containing forms. As a result, the leaching concentration of lead was the highest under the supposition condition of lead-sinker deposited on sandy tidal flat. In this study, as a subsequent study, we investigated long-term leaching characteristics from lead-sinker deposited on sandy tidal flat. We used a serial batch leaching experiment to investigate the long-term leaching characteristics, and the experimental conditions were as follows; solid to liquid ratio 1:20, shaking time 24 hours (repetition of 7 times), room temperature, and shaking rate 170 rpm. As a result, lead leaching concentration after shaking for 24 hours was 0.215 mg/L, showing the highest leaching concentration, and then the leaching concentrations between 2-7 times were greatly decreased. Analysis result by Visual Minteq 3.1 said most of the leached lead component could be extracted as crystal such as Anglesite (PbSO4), Cerrusite (PbCO3), Cotunnite (PbCl2), and Pb(OH)2 by sulfate and carbonate in seawater.

Reuse, recycling and recovery (3R) of industrial wastes are common and encouraging in Korea. Industrial symbiosis is one of typical methods for implementing 3R and has been defined as engaging “traditionally separate industries in a collective approach to competitive advantage involving physical exchange of materials, energy, water, and by-products”. The keys to industrial symbiosis are collaboration and the synergistic possibilities offered by geographic proximity. Recently, several countries in East Asia such as Taiwan, South Korea, Japan and China are promoting ‘designed’ symbiosis networks in various industrial complexes based on their national Eco-industrial Park (EIP) demonstration programs. Despite the recently promoted EIP initiatives worldwide, only very few studies furnish the operational and functional details of ‘designed’ industrial symbiosis networks, starting from the planning to implementation stage. The production of terephthalic acid (TPA) in Korea is 6.5 million ton based on 2011. The production of waste generated in the process of TPA is about 15,000 ton/yr and included useful materials like residue TPA as well as isophthalic acid (iPA), benzoic acid (BA) and p-toluic acid (p-TL). Until now, TPA waste was incinerated due to high caloric value. This study was conducted for recovery of valuable materials from industrial waste and utilization of recovered material as an example of Korean EIP. In this study, the experiment was performed to separate above four materials from the waste by solvent (methanol and water) extraction. The solubility of TPA (0.1g/100g) for methanol is relatively low compared to other materials. Also the solubility of BA (68g/L at 95℃) and p-TL (11.6g/L at 98℃) for water is relatively high in comparison with other materials. Finally, BA was separated from p-TL by molecular distillation system. The purity of recovered materials was analyzed by ultra-high performance liquid chromatography (Waters Xevo TQ system). The recovery rate and purity of BA is 90% and 93%. The recovered BA could be recycled the companies which are produced plastic plasticizer and paints.

In this study, the experiment was carried out to produce methane by applying Semi-Continuous Leachate Recirculation Anaerobic Digestion System fed with source separated food waste from school cafeteria. There were two systems and each system consisted of a bioreactor and a leachate tank. Each bioreactor had a screen near the bottom of the reactor. 2L of Separated leachate was collected to the leachate tank each day by using a tubing pump and the leachate from the leachate tank was pumped to the bioreactor at the upper of the bioreactor. Through this circulation, the leachate having high concentration of VFAs was supplied to the bioreactor. At the beginning of the experiment, food waste/inoculum anaerobic sludge volume ratio was 2:8 that is 9g VS/L of OLR(Organic Loading Rate). Feeding was conducted every two weeks. Initial conditions of bioreactor was 30g VS/2･week and 33g VS/2･week were fed to bioreactor A and bioreactor B, respectively. Average biogas yields of the bioreactor were 0.723m³ Biogas/kg VS added in reactor A and 0.648m³ Biogas/kg VS added in reactor B.

Experimental studies were carried out on surface area of char during pyrolysis of sewage sludge. To evaluate surface area of resultant char we use iodine number. Increase of iodine number shows that the surface area of char increases. The process parameters, temperature and holding time have significant effect on surface area of char. Increasing temperature above 400℃ surface area of char decreases while slightly increasing when holding time increases. In this study, the optimum conditions for high surface area of resultant char were found 400℃ and 30minutes, respectively.

We carried out to investigate of CO2 reaction mechanism in oxy gasification reaction field. Capacity of gasification system is 0.5ton/day and that consists of feeder, gasification reactor assembled ash melting function, multi cyclone, wet scrubber, combustion chamber, heat exchanger, bag filter, ID fan and noncatalyst (steam reformer)/catalyst reformer. Gasification temperature was about 1,400~1,450℃ and RPF was used as a input material. We confirmed to possibility of Boudouard Reaction at the oxy gasification system. Boudouard Reaction is a reaction between carbon(soot) and carbon monoxide in the reaction field. We can find that the more Boudouard Reaction, the more residence time. For optimal reforming conditions such as temperature, amount of steam and residential time were investigated. It can be acquired that conditions of 45% H2 concentration and 3.0 H2/CO ratio in non-catalyst syngas reforming test and conditions of 60% H2 and 35% CO2 concentration in catalyst syngas reforming test.

The world consumption of the coal has been increased very sharply during past few years result from oil exhaustion, fluctuation in the price of oil and low price competitiveness of alternative energy. The International Energy Agency (IEA) has estimated that coal will be available for over 110 years, with coal reserves of close to 860 billion tons. The pulverized coal is blended coal powder that the particle diameter under 10μm. It has advantage of combustion efficiency and flame stabilization. The use of coal blends is becoming increasingly common in pulverized-coal power plants because it improves the economic performance of these plants by diversifying the fuel range. However, although blending can improve combustion behaviors and decrease gaseous pollutant emissions, it has difficulty of design and operating the pulverized coal combustor because despite the small particle size, combustion process of pulverized coal is exceedingly complex. Because of that the detail study on the combustion characteristic is important for increasing of efficiency. As a base investigation for numerical calculation of pulverized coal combustion, this study verified validity of models and compare the numerical calculation results with the experimental results.

아바타는 <나의 분신>이라 불리는 사이버상에서 캐릭터를 이르는 단어로, 본 연구에서는 MMORPG 게임에서 자신을 치장하며 실제 자기표현과 이상화(理想化) 기능을 하는 캐릭터로 정의하 였다. 본 연구를 통해 멀티 아바타와 성별 전환 사이에서 작동하는 유병률(有病率)을 설명하는 것을 목적으로 하였다. 본 실험을 위하여 선행된 방법은 유저에게 지정된 게임 연습과 질문을 미리 제공하 였고, 이는 선행적으로 사용자에게 게임 동기를 발생하여 아바타 생성에 도움을 주고자하는 것이 목 적이었다. 본 연구를 통해 연령, 성별과 성전환 사이에 상관관계를 살펴보았고, 비 전형적인 방식에서 는 성전환 가능성이 높아졌고 일반 참가자 또한 절반의 성전환 선택의 경향을 보여주었다. 마지막으 로, 경험의 성격 특성에 대한 경험에 대한 개방성은 성별과 유사한 상관관계를 보였다.

Connexin (Cx) is a complex which allows direct communication between neighboring cells via exchange of signaling molecules and eventually leads to functional harmony of cells in a tissue. The initial segment (IS) is an excurrent duct of male reproductive tract and expression of numerous genes in the IS are controlled by androgens and estrogens. The effects of these steroid hormones on gene expression in the IS during postnatal development have not extensively examined. The present research investigated expressional modulation of Cx isoforms in the IS by exogenous exposure to estrogen agonist, estradiol benzoate (EB), or androgen antagonist, flutamide (Flu), at weaning age. Two different doses of EB or Flu were subcutaneously administrated in 21-day old of male rats, and expressional changes of Cx isoforms in the adult IS were analyzed by quantitative real-time PCR. Treatment of a low-dose EB (0.015 μg/kg body weight) resulted in an increased expression of Cx31 gene and a decreased expression of Cx37 gene. A high-dose EB (1.5 μg/kg body weight) treatment caused an increase of Cx31 gene expression. Increased levels of Cx30.3 and Cx40 transcripts were observed with a low-dose Flu (500 μg/kg body weight) treatment. Treatment of high-dose Flu (50 mg/kg body weight) led to expressional increases of Cx30.3, 40, and 43 genes. Our previous and present findings suggest differential responsiveness on gene expression of Cx isoforms in the IS by androgens and estrogens at different postnatal ages.

This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.

The purpose of the present study was to examine the seminiferous epithelium cycle of Bombina orientalis using a light microscope. The cycle was divided into a total of 10 stages, according to the morphological characteristics of the cells. The spermatogenetic cells included primary spermatogonia, secondary spermatogonia, primary spermatocytes, secondary spermatocytes, spermatid and sperm. At stageⅠ, the primary spermatogonia was located closer to basal lamina of the seminiferous tubule without spermatocyst formations. Especially at the stage Ⅱ, the secondary spermatogonia were located in the spermatocyst. The primary and secondary spermatocytes were found from stages Ⅲ to Ⅵ. The secondary spermatocytes were smaller in size than the primary spermatocytes, but they had thicker nucleoplasm and smaller nuclei. The round-shaped, early sperm cells were formed in stage Ⅶ, and further divided at stage Ⅷ to have more concentrated nucleoplasm before division to matured sperm cells. At stage Ⅹ, the matured sperm cells emerged from the spermatocyst. Considering the above results, this study presented the special characteristics in the generation and type of sperm formation. The germ cell formation occurred in various stages, like the perspectives of Franca et al (1999), ultimately, providing taxonomically useful information.

Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves.

Direct cell-cell communication through connexin (Cx) complexes is a way to achieve functional accordance of cells within a tissue or an organ. The initial segment (IS), a part of the epididymis, plays important roles in sperm maturation. Steroid hormones influence on expression of a number of genes in the IS of adult animals. However, developmental effect of sex hormones on the gene expression in the IS has not been examined. In this study, estradiol benzoate (EB, an estrogen agonist) or flutamide (Flu, an androgen antagonist) was exogenously administrated at 1 week of postnatal age, and expressional changes of Cx genes in the IS were determined at 4 months of age by a quantitative real-time PCR analysis. Treatment of EB at 0.015 mg/kg body weight (BW) increased expression of Cx30.3, 31.1, and 43 genes. However, treatment of 1.5 mg EB/kg BW resulted in expressional decreases of Cx31, 32, and 45 genes and caused increases of Cx30.3 and 43 gene expression. Significant decreases of Cx31, 31.1, 32, 37, and 45 gene expression were detected with a treatment of 500 mg Flu/kg BW, while expression of Cx43 gene was significantly increased with a treatment of 500 mg Flu/kg BW. A treatment of 50 mg Flu/kg BW led to significant increases of Cx30.3, 32, 37, 40, and 43 gene expression. These findings imply that exogenous exposure of steroidal hormones during the early developmental period would result in aberrant expression of Cx genes in the adult IS.

Autophagy is a homeostatic degradation process that is involved in tumor development and normal development. Autophagy is induced in cancer cells in response to chemotherapeutic agents, and inhibition of autophagy results in enhanced cancer cell death or survival. Chloroquine (CQ), an anti-malarial drug, is a lysosomotropic agent and is currently used as a potential anticancer agent as well as an autophagy inhibitor. Here, we evaluate the characteristics of these dual activities of CQ using human colorectal cancer cell line HCT15. The results show that CQ inhibited cell viability in doseand time-dependent manner in the range between 20 to 80 uM, while CQ did not show any antiproliferative activity at 5 and 10 uM. Cotreatment of CQ with antitumor agent NVP-BEZ235, a dual inhibitor of PI3K/mTOR, rescued the cell viability at low concentrations meaning that CQ acted as an autophagy inhibitor, but CQ induced the lethal effect at high concentrations. Acridine orange staining revealed that CQ at high doses induced lysosomal membrane permeabilization (LMP). High doses of CQ produced cellular reactive oxygen species (ROS) and cotreatment of antioxidants, such as NAC and trolox, with high doses of CQ rescued the cell viability. These results suggest that CQ may exert its dual activities, as autophagy inhibitor or LMP inducer, in concentration-dependent manner.

최근 전력 전송을 위해 지하에 건설되는 전력구 구조물이 증가함에 따라, 이러한 구조물의 수명 연장은 매우 중요한 문제로 대두되고 있다. 현재까지의 현장 및 실험결과들은 콘크리트 내부의 철근이 콘크리트 피복의 탄산화 현상에 의해 부식될 수 있음을 보이고 있으며,이러한 탄산화에 의한 철근의 부식은 구조물 주변의 높은 이산화탄소 농도에 의해 빈번히 발생할 가능성을 내포하고 있다. 따라서, 본 연구에서는 실제 전력구 현장에서의 철근 깊이와 탄산화 깊이를 측정한 결과를 바탕으로 우리나라의 전력구 콘크리트 구조물에 대한 탄산화위험도를 평가하였다. 현장 데이터를 기반으로 철근 주변에서의 탄산화에 의한 전력구의 사용수명을 평가하였으며, 이를 위해 확률론적 방법인 몬테카를로 기법을 적용하였다. 또한 균열을 유발한 시험체에 대한 탄산화 촉진 실험을 수행하여, 그 실험결과를 바탕으로 균열을 고려한 경우의 전력구의 사용수명을 수치적으로 평가하고 분석하였다.

The aim of this study is to evaluate the possibility of improvement quality of a city inhabitancy and comfort creation in a daily life in an environment of population in developing cities by reconstruction an existing engineering - architectural building and a construction and creations of new intellectual architectural projects.

Guppy has become a model organism for studying behavioral traits such as courtship and mate choice, as well as for understanding ecogeographic adaptation. Unfortunately, studying the early development of live bearers is more complicated than that of oviparous species, due to the inaccessibility of developing embryos for experimental manipulation. Ulrike et al. showed that the embryos could not be cultured for the entire period of their embryonic development. To optimize conditions embryo in vitro culture we established system for varying the concentration of fetal bovine serum in the medium impact on the embryonic development of in vitro embryos. For in vitro culture, embryos were incubated in 8 ml of sterile embryo medium (L-15 [Leibovitz] medium, supplemented with 5, 10, 15, and 20% fetal bovine serum respectively, 20 units/ml penicillin, and 200 mg/ml streptomycin) in a dark incubator at 25℃. Our study found that in 5% of FBS of the medium, embryos can be maintained until the middle-eyed. In 10% and 15% embryos can be maintained constant development; some of them can be fed; however, in 15% it is faster than 10%. And although in 20% of FBS can sustain rapid development of early stage, but ultimately died. According to our experimental data, both 10% and 15% FBS in medium can be used for in vitro culture, the slowly development in 10% FBS appears to be more conducive to observation.

Development of the central nervous system (CNS) occurs normally in mammalian fetus despite lower temperature in the brain region than in the heart. To investigate the effects of temperature niche on the neural differentiation of stem cells in vitro, P19 embryonic carcinoma (EC) stem cells and N2a neuroblastoma stem cells were induced to undergo neural differentiation by retinoic acid and LiCl, respectively. The cells were analyzed for the expression of neural marker genes during 12 days differentiation. Although there were Map2 and NCAM expressions in both groups, no clear difference was found. Similarly, expression patterns of Tuj1 and NF-M were not different in both groups, showing more intensive staining patterns at day 12 than those at days 4 and 8, respectively. However, more cells expressed GFAP markedly at day 12 in 37℃ group. There was little expression of the above markers in N2a cells during differentiation except for Ngn2 and Tuj1. It was found that Ngn2 was expressed more intensely at days 6 and 9 in 33℃ group. Tuj1 expression showed a similar pattern to those of P19 EC cells. RT-PCR analysis also showed that the expressed transcripts did not quite different in both groups, although they were different among the days of differentiation. Thus, it appears that neural differentiation occurs normally with a slight delay and probably less cell death in the cells at 33℃ than that at 37℃.