• Korean Journal of Organic Agriculture
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• v.18 no.3
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• pp.291-313
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• 2010

The objective of this paper is to apply choice experiment methods to estimate non-market value of organic farming and its policy implication. A preliminary survey shows that the attributes of organic farming are reduce environmental pollution, bio-diversity improvements, cultural diversity improvements and maintain local community, reduce green-house gas emissions, energy saving, landscape improvements and tax for organic farming improvement policy. Questionnaire was eight different choice sets presented to each respondent. Implicit values of the attributive levels of organic farming have been calculated into tax money costs per house. This paper compared the six feasible scenarios in terms of willingness to pay per year. This study is expected to contribute to government's organic farming policies and quantitative information related to practice of organic farming.

• Journal of the Korea Furniture Society
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• v.27 no.4
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• pp.302-308
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• 2016

It has been known that acetylation improves the dimensional stability of wood. Liquid phase acetylation is more popular than gas-phase acetylation for the effectiveness of weight gain of wood. In this study the specimens of domestic red and Korean pines are acetylated in liquid phase and their physical properties, such as density, bending strength, anti-hygroscopicity etc., are analyzed. Acetylation increases the average weights and volume of larch specimens by 11.4% and 3.4%, respectively, and their average oven-dry densities are increased by $0.03g/cm^3$. Acetylation does not influence on Modulus of Rupture (MOR) and Modulus of Elasticity (MOE). The average Percentage Reduction in Hygroscopicity (PRH) and average Percentage Reduction in Water soaking (PRW) of larch specimens are respectively 20.2% and 20.8%. Thus it can be concluded that acetylation improves the dimensional stability of larch specimens.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.691-709
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• 2007

Concerns on environmental waste problems caused by non-biodegradable petrochemical-based plastic packaging materials as well as consumer's demand for high quality food products has caused an increasing interest in developing biodegradable packaging materials using annually renewable natural biopolymers such as polysaccharides and proteins. However, inherent shortcomings of natural polymer-based packaging materials such as low mechanical properties and low water resistance are causing a major limitation for their industrial use. By the way, recent advent of nanocomposite technology rekindled interests on the use of natural biopolymers in the food packaging application. Polymer nanocomposites, especially natural biopolymer-layered silicate nanocomposites, exhibit markedly improved packaging properties due to their nanometer size dispersion. These improvements include increased mechanical strength, decreased gas permeability, and increased water resistance. Additionally, biologically active ingredients can be added to impart the desired functional properties to the resulting packaging materials. Consequently, natural biopolymer-based nanocomposite packaging materials with bio-functional properties have huge potential for application in the active food packaging industry. In this review, recent advances in the preparation and characterization of natural biopolymer-based nanocomposite films, and their potential use in food packaging applications are addressed.

• Preventive Nutrition and Food Science
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• v.17 no.3
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• pp.234-238
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• 2012

The volatile aroma constituents of Chrysanthemum zawadskii var. latilobum K. were separated by hydro distillation extraction (HDE) method using a Clevenger-type apparatus, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of C. zawadskii var. latilobum K. flower essential oil (FEO) was 0.12% (w/w) and the color was light green. Fifty-five volatile chemical components, which make up 88.38% of the total aroma composition, were tentatively characterized. C. zawadskii var. latilobum K. FEOs contained 27 hydrocarbons, 12 alcohols, 7 ketones, 4 esters, 1 aldehyde, 1 amine, and 3 miscellaneous components. The major functional groups were terpene alcohol and ketone. Borneol (12.96), (${\pm}$)-7-epi-amiteol (12.60), and camphor (10.54%) were the predominant volatiles. These compounds can be used in food and pharmaceutical industries due to their active bio-functional properties.

• Journal of Life Science
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• v.9 no.6
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• pp.653-658
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• 1999

A novel marine microorganism, Vibrio sp. YE-101, was isolated from pufferfish and investigated for its ability to synthesize tetrodotoxin (TTX). Various strains isolated from the intestine of pufferfish were grown on TCBS agar plate, and then cultured on Ocean Research Institute (ORI) medium supplemented with 3% NaCl at 23$^{\circ}C$ for 3days. The cells were harvested, disrupted, fractionated by Bio-Gel P-2 column chromatography and then TTX-producing strain, Vibrio sp. YE-101, was identified using mouse bioassay. The isolated TTX from Vibrio sp. YE-101 was also analyzed and identified by HPLC and gas chromatography-mass spectrometer (GC-MS). The mass fragmentation of trimethylsilyl derivatives of C9-base of TTX from Vibrio sp. YE-101 was interpreted and the pattern of fragmentation was same with that of authentic standard. The purfied TTX was also positive to the mouse bioassay, which clearly represents that Vibrio sp. YE-101 can synthesize TTX.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.528-528
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• 2012

Recently, atmospheric pressure plasmas attract lots of interests for the useful applications such as surface modification and bio-medical treatment. In this study, a particle-in-cell Monte Carlo collision (PIC-MCC) simulation was adopted to investigate the discharge characteristics of a planar micro dielectric barrier discharge (DBD) with a driving frequency from 13.56 MHz to 162.72 MHz and with a gap distance of 80 micrometers. The variation of frequency, in the change in the electron energy probability function (EEPF). Through the relation between the ion trajectories and the frequency, results in the change of EEPFs is achievable with the turning point of frequency mode. Therefore, it is possible to categorize the efficient operation range of DBDs for its applications by controlling the interactions between plasmas and neutral gas for the generation of preferable radicals.

• Journal of Biosystems Engineering
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• v.28 no.4
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• pp.285-294
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• 2003

This study was carried out to propose a new-concept internal combustion engine which has great potential advantages to the conventional engines. Proposed new-concept engine is a kind of rotary engine. A rotor is rotating concentrically in a cylinder which is divided into two partitioning valves, and it makes four compartments in the cylinder. The volumes of each of four compartments are changing continuously with the rotor movement and performs the functions of intake, compression. expansion and exhaust simultaneously. Expected thermal efficiency for the real cycle is 26 percent at conditions of 1,000 rpm and compression ratio of 8.0, which is 3 to 4 percent higher than that of the conventional engines such as the piston engine, gas turbine and Wankel rotary engine. A simulation procedure proved that the new concept engine is functional, and has many potential advantages compared to the existing conventional engines.

• Carbon letters
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• v.13 no.1
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• pp.48-50
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• 2012

Mass production of graphene-based materials, which have high specific surface area, is of importance for industrial applications. Herein, we report on a facile approach to produce thermally modified graphene oxide (TMG) in large quantities. We performed this experiment with a hot plate under environments that have relatively low temperature and no using inert gas. TMG materials showed a high specific surface area (430 $m^2g^{-1}$). Successful reduction was confirmed by elemental analysis, X-ray photoelectron spectroscopy, thermogravimetic analysis, and X-ray diffraction. The resulting materials might be useful for various applications such as in rechargeable batteries, as hydrogen storage materials, as nano-fillers in composites, in ultracapacitors, and in chemical/bio sensors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1972-1977
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• 2007

Micro plasma has been recently studied to investigate the effects on various cells. We study a micro-plasma produced by a plasma needle that is operated with RF power and its effects on G361 melanoma cells. The micro plasma size ranges from sub-mm to several mm at a few watts of RF power. For the bio-medical treatment, low-temperature plasma is obtained and gas temperature is controlled within several tens of degrees $(^{\circ}C)$ in order not to disturb cell activities. Elementary spectroscopic studies to obtain plasma characteristics are presented for Ar and He plasma with different frequencies of RF power. Also the preliminary results of the micro plasma effects on G361 melanoma cells are presented. It was observed that the irradiation of micro plasma induces cell death through the deprivation of tyrosine phosphorylation in the G361 cells.

• Journal of Aquaculture
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• v.18 no.2
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• pp.130-132
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• 2005

Genomics research has two ultimate applied goals: to Isolate and clone genes of economic importance for bio-technology and gene-assisted selection (GAS), and to locate and use markers for marker-assisted selection (MAS) in selective breeding programs. To this end, we have identified linked markers for feed conversion efficiency growth rate, and disease resistance to enteric septicemia of catfish (ESC). Three microsatellite markers Ip266, Ip384, and Ip607 were identified to be linked to feed conversion efficiency. Similarly one marker each was identified to be linked to growth rate (Ip607) and disease resistance to ESC (Ip477). Ip607 marker linked to both growth rate and feed conversion efficiency, indicating that the QTL for both growth rate and feed conversion efficiency may either be the same or located in the same chromosomal region in the catfish genome. On phenotypic evaluation, certain traits such as growth rate can be accurately evaluated by body weight evaluation while other traits such as disease resistance can be quite complex. The linked DNA markers will be highly useful for MAS programs and for directing further efforts of genomic mapping for important quantitative traits.