• Bulletin of the Korean Chemical Society
• /
• v.32 no.1
• /
• pp.213-218
• /
• 2011

The scope of homogeneous Lewis acid-catalyzed benzo[N,N]-heterocyclic condensation was expanded to include the use of various metal salts not reported in the literature and $SnCl_2{\cdot}2H_2O$ was finally selected. Among various solid supports activated with $SnCl_2$, heterogeneous $SnCl_2/SiO_2$ proved to be the most effective and significantly higher conversions were achieved compared to $SnCl_2{\cdot}2H_2O$ itself. The results of TG-DTA and BET indicated that dispersed $SnCl_2$ coordinates with surface hydroxyl groups of silica leading to formation of stable Lewis acid sites. Low catalyst loading, operational simplicity, practicability and applicability to various substrates render this eco-friendly approach as an interesting alternative to previously applied procedures.

• Journal of Environmental Policy
• /
• v.6 no.1
• /
• pp.61-81
• /
• 2007

Types of agricultural policy can be catagorized into two general cases: price and income supports. Income supports are any government program designed to provide farmers with higher incomes than they would receive otherwise. These direct cash payments to farmers are known as "deficiency payment" or "direct payment" because they compensate the farmer for the failure of the market to provide farmers with adequate prices. The direct payment to environment-friendly agriculture is a form of income supports for the agriculture production using less pesticides and chemical fertilizers. Because no significant regulation exists on the use of fertilizers substituting chemical fertilizers for crop, the role of the payment on reducing environmental impacts of agriculture is not entirely clear. This uncertainty is likely to be particularly severe in the case that farmers with low-quality land showing greater demand for fertiliser have an incentive to transition to environment-friendly agriculture. The paper shows the case of the current payment system in Korea.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.3
• /
• pp.204-209
• /
• 1994

The synthesis of N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methylester (Z-APM), a precursor of aspartame, from N-(benzyloxycarbonyl)-L-aspartic acid (Z-Asp) and L-phenylalanine methylester hydrochlolide($L-PM\cdot HCI$) was investigated in a saturated-ethylacetate single phase system using immobilized thermolysin. Among the various supports tested, glyceryl-CPG was found to be most efficient for retaining enzyme activity. The enzyme immobilized onto glyceryl-CPG also showed the highest activity for Z-APM synthesis in saturated ethyl acetate. Z-APM conversion yield in saturated ethylacetate was half of that obtained in an ethyl acetate-buffer two-phase system under the same reaction conditions. However, as the mole ratio of $L-PM \cdot HCI$ to Z-Asp was increased to 4.0, the conversion yield reached 95 %. When continuous synthesis of Z-APM was canied out in a plug flow reactor (PFR) with 80 mM of L-PMㆍHCI and 20 mM of Z-Asp in saturated ethylacetate (pH 5.5), more than 95 % of Z-Asp was converted to Z-APM with a space velocity of 1.16 $hr^{-1} at 40^{\circ}C$. Although the operational stability in PFR was reduced rapidly, more than 80% of initial activity was maintained in CSTR even after a week of operation.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.1
• /
• pp.14-17
• /
• 2002

To increase the efficiency of a two-stage anaerobic wastewater digestion system, various polymers were added to the methanogenic reactor as supports. The addition of polyurethane addition (6%, w/v) to the methanogenic reactor facilitated the organic loading rate (2-day Hydraulic Retention Time), higher than that of the conventional methanogenic reactor (6-day HRT). During the operation of the polyurethane-added reactor, a significant decrease in the organic mass in the effluent (COD 5-6 kg/l) was achieved, compared to that of the conventional reactor (COD 15-20 kg/l). The methane gas production rate also improved about 3-fold in the polyurethane-added reactor. More biomass was found to accumulate in the polyurethane-liquid phase (volatile solid, 26-28kg) than in the free-liquid phase (volatile solid, 5- 7 kg/l) after 90 days of operation. A scaled-up experiment with a polyurethane-added 2.5-1 reactor confirmed the previous results, and no adverse effects such as plugging or channeling due to decreased efficiency was observed even after 4 months of operation.

• Korean Journal of Organic Agriculture
• /
• v.21 no.1
• /
• pp.1-18
• /
• 2013

Animal and crop production systems were integrated on a single farm. This integrated farming system recycled nutrients on the farm. The separation of animal and crop production with the introduction of cheap commercial fertilizers, farms were not used land-applied manure. The on-line manure matching is one of the emerging business in the achievement of recycling and resource recovery. The manure matching actively promotes the reuse and recycling of by-products and manure. This study constructs to manure matching information system to solve the exchange problems between herders and croppers. Manure matching web sites designed. This paper introduces a web-based animal manure matching system. A manure matching service, part of the manure transport, links farmers who produce excess manure with farmers who can use the manure. Farmers registered with the service have requested manure. The manure matching service supports the transport project by linking farmers with excess manure with those farmers who can utilize the manure safely as a nutrient source. The goal of the service is to protect water quality by fostering efficient land application. Benefits to those who use the manure network include reduced disposal costs, lower purchase costs and recycling of manure. The manure matching is based on the principle that 'one persons waste is another person's fertilizer.' It provides a free online matchmaking service for environmentally safe manure recycling management system.

• Korean Journal of Organic Agriculture
• /
• v.28 no.1
• /
• pp.69-93
• /
• 2020

The paper is to compare two villages in Songak-myeon, Asan, Cnungnam Province in Korea. It tries to show how the joint village project, which began with the support of the same external organization, produces different results depending on the internal conditions and circumstances of the village. From the end of the 1990s, Pyeongchon-ri and Sugok-ri started developing villages under the influence of the environmentally friendly farming movement. And subsequent supports were provided by local organizations for the development of the village. However, the village project in Sugok-ri, which focused on economic performance, later turned out to be a failure, and the residents changed to pursue activities for their own economic interests individually. On the other hand, In Pyeongchon-ri, the cooperation among villagers was strengthened in implementing support projects by similar external agencies. In addition, community ties and identity have been strengthened as problems have been solved through cooperation among residents in the process of promoting the village project. Nevertheless, projects undertaken in Pyeongchon-ri for the purpose of increasing economic performance was all failed. Through these findings, the paper asserts that the neo-endogenous development approach utilizing external support on the basis of internal cooperative network among villagers must be a very useful method for rural development in contemporary societies.

• Asian Journal of Turfgrass Science
• /
• v.10 no.3
• /
• pp.247-262
• /
• 1996

In this study, the distribution of dictyostelid cellular slime molds was investigated from F, H and $A_1$ horizon of pinus, oak forests in Mt. Puk'an, Mt. Nam and Mt. Kwanak. The relationship of cellular slime molds with other soil microorganisms and abiotic factors were analyzed. The six species were isolated as follows: Polysphondlium pallidurn, Dictyostelium purpureum, D. mucoroides, D. crassicaule, D. capitatum, D. implicatum. The dominant species in pinus forests was P. pallidum, and in oak forests it was D. macro ides. In Mt. Nam, D. mucoroides and P. pallidum were isolated at only oak forest. The Correlations of slime mold abundance with bacteria were significant. Even though positive correlations of cellular slime molds with actinomycetes or fungi were not significant, correlations between soil microorganisms were analyzed. Correlation coefficients were high in Mt. Kwanak(r=0.5921) and Mt. Nam(r=0.7243) at significant level P<0.01. There were significant correlations between total slime molds and abiotic factors. It supports that cellular slime molds are limited by foods in nature. In low level of pH, water content and organic matter, that community diversity is more affected by bacteria whose organic degradation capacity is regulated by interactions of soil microorgaisms. Key words: Cellular slime molds, Soil microorganisms, Correlations, Abiotic factors.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.1
• /
• pp.211-220
• /
• 2013

The characteristic fluorescence properties of quercetin (QCT) and apigenin (API) were studied in various $CH_3OH-H_2O$ and $CH_3CN-H_2O$ mixed solvents. The structure of QCT is completely planar. API is not planar at the ground state but becomes nearly planar at the excited state. If the molecules are excited to the $S_1$ state in organic solvents, QCT exhibits no fluorescence due to excited state intramolecular proton transfer (ESIPT) between the -OH and the carbonyl oxygen, but API shows significant fluorescence because ESIPT occurs slowly. If the molecules are excited to the $S_2$ state, both QCT and API exhibit strong $S_2{\rightarrow}S_o$ emission without any dual fluorescence. As the $H_2O$ composition of both solvents increases, the fluorescence intensity decreases rapidly due to the intermolecular hydrogen bonding interaction. The theoretical calculation further supports these results. The change in fluorescence properties as a function of the solvatochromic parameters was also studied.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.11
• /
• pp.4377-4384
• /
• 2014

According to the World Health Organization (WHO), 1.37 million people died of lung cancer all around the world in 2008, occupying the first place in all cancer-related deaths. However, this number might be decreased if patients were detected earlier and treated appropriately. Unfortunately, traditional imaging techniques are not sufficiently satisfactory for early detection of lung cancer because of limitations. As one alternative, breath volatile organic compounds (VOCs) may reflect the biochemical status of the body and provide clues to some diseases including lung cancer at early stage. Early detection of lung cancer based on breath analysis is becoming more and more valued because it is non-invasive, sensitive, inexpensive and simple. In this review article, we analyze the limitations of traditional imaging techniques in the early detection of lung cancer, illustrate possible mechanisms of the production of VOCs in cancerous cells, present evidence that supports the detection of such disease using breath analysis, and summarize the advances in the study of E-noses based on gas sensitive sensors. In conclusion, the analysis of breath VOCs is a better choice for the early detection of lung cancer compared to imaging techniques. We recommend a more comprehensive technique that integrates the analysis of VOCs and non-VOCs in breath. In addition, VOCs in urine may also be a trend in research on the early detection of lung cancer.

• Membrane Journal
• /
• v.27 no.1
• /
• pp.1-42
• /
• 2017

Metal-organic frameworks (MOFs) are nanoporous materials that consist of organic and inorganic moieties, with well-defined crystalline lattices and pore structures. With a judicious choice of organic linkers present in the MOFs with different sizes and chemical groups, MOFs exhibit a wide variety of pore sizes and chemical/physical properties. This makes MOFs extremely attractive as novel membrane materials for gas separation applications. However, the synthesis of high-quality MOF thin films and membranes is quite challenging due to difficulties in controlling the heterogeneous nucleation/growth and achieving strong attachment of films on porous supports. Microwave-based synthesis technology has made tremendous progress in the last two decades and has been utilized to overcome some of these challenges associated with MOF membrane fabrication. The advantages of microwaves as opposed to conventional synthesis techniques for MOFs include shorter synthesis times, ability to achieve unique and complex structures and crystal size reductions. Here, we review the recent progress on the synthesis of MOF thin films and membranes with an emphasis on how microwaves have been utilized in the synthesis, improved properties achieved and gas separation performance of these films and membranes.