• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.362-370
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• 2013

The coconut shell based activated carbon was applied for EDLC (electric double layer capacitor) electrode with the post treatments. The electrochemical properties were evaluated with a coin cell using the activated carbon as electrode. The initial gravimetric and volumetric capacitance of the coconut shell based activated carbon electrode s were 66 F/g and 39 F/cc, and these values decreased to 54 F/g and 32 F/cc after 100 cycles, respectively showing 82% of charge-discharge efficiency. The properties of CV graph with the commercial activated carbon electrodes showed the serious polarization as the result of additional reaction between electrolyte and impurities of the electrode materials. In order to remove impurities efficiently, the commercial activated carbon was treated by alkali and acid solutions consecutively, and then heat treated to control the pore size distribution and the content of surface functional groups. The surface functional groups decreased with the increased heat temperature and the specific capacitance increased with the decreased surface functional groups. The initial capacitance of coconut shell based activated carbon elec trode which was treated with NaOH and HNO3, and then heat treated at $800^{\circ}C$ was 44 F/cc, and the value turned out to be 42 F/cc after 100 cycles, showing over 95% of charge-discharge efficiency.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.74-84
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• 2002

This experiment was carried out to evaluate supplemental effects of various preservatives to preserve the Brewers grain and Soymilk from decay and degeneration. The NaCl, organic acid(Ca-propionate), microbial fermenter(H/MF inoculant), and methionine hydroxy analogue(MHA) were used as additives in order to compare preservability of brewers grain and soymilk by-product during 20 days at July to August. Most treatments were appeared rapid decay and degeneration as soften and covered with molds on surface from the early days of experiment. However, MHA treatments showed any change until 20 days of storage. In terms of pH and $NH_3-N$ contents, only MHA treatment showed a stable and low value. The other treatments including Control showed high values as time flowed or unstable states. In conclusion, when high moisture agricultural by-product was treated by over 5% of MHA, there was no significant physicochemical changes in long term preservation over 20 days at summer season.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.72-81
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• 2004

For disposal food wastes which is about 30% portion of tatal organic wastes, vermicomposting is more environmental-friendly treatment than lanfill, incineration, etc. Recently, the interest has been increasing but there are many problems on management of vermicopmposting in field especially. This study was conducted to investigate an optimal factors, which are limit NaCl conc., the mixing rate of food wastes and casting for growth of an earthworm related to efficient vermicomposting. The limit conc. of NaCl was 0.5% and in case of feeding food wastes to earthworms as a prey only, most earthworms were dead in a few hours due to excessive degradation of organic materials and high NaCl conc. However as feeding with the casting of proper mixing rate(3:7), most earthworms were survived until finishing composting. It was investigated the increaser degree of matureness of food wastes, the higher conc. of NaCl, therefore for efficient vermicomposting, it seemed proper mixing rate of food wastes and the casting is better than matureness of food wastes. and the most suitable mixing rate was 3:7 food wastes and the casting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.10-16
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• 1997

To confirm the possibility of seaweed extracts for functional food, water or ethyl alcohol solubles were extracted from laver, Porphyra yezoensis and evaluated those food components such as proteins, carbohydrates, nucleic acids, taurine, pigments and browning extent. The amount of proteins, polysaccharides and nucleic acids extracted decreased with increasing ethyl alcohol concentration, which was maximal when water was used as extraction solvent. The extractability of proteins, polysaccharides and nucleic acids was different between the dried and the roasted laver. Taurine was extracted about 1% from the dried and the roasted laver in the range of o~7o% ethyl alcohol concentration. The amount of carotenoids extracted by 95% ethyl alcohol from the dried and the roasted laver were 146.6 and 138.4mg%, respectively, which was 66 ~ 80% of yield extracted by methanol/acetone(1/1) solvent. The browning value of 50 ~6o% ethyl alcohol extraction group from roasted laver was highest among water/ethyl alcohol extraction group. The extraction yield was maximum when laver was extracted with water, and the value was 26.3% for the dried laver and 27.5% for the roasted layer. Organoleptic characteristics from four kinds of extraction groups containing hot water extraction showed that extracts from the roasted laver were evaluated most eminent and thought to be applicable to various preparation of food.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.443-452
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• 2006

This study was conducted to investigate the site and growth characteristics of Mackia amurensis stand in natural forest of Mt. Joongwang, Pyongchang-Gun, Gangwon-Do, Korea. The 28 sample plots ($30m{\times}30m$) were established to examine the vegetation and site characteristics for M. amurensis stand. Stem analysis was performed on two sample trees for each of the 5 plots situated at intervals of 100 m by altitude. M. amurensis trees were mainly distributed at the ridge and the slope facing north, with altitudes ranging from 790 to 1,170 m. The M. amurensis grew at relatively deep A-layer of soil with high moisture but infertile. Dominant species with M. amurensis were Quercus mongolica, Fraxinus rhynchophylla, Acer pseudo-sieboldianum, A. pictum subsp. mono, Ulmus davidiana var., japonica, Tilia amurensis, and Populus davidiana. TWINSPAN classified four communities in Mt. Joongwang area; M. amurensis-P. davidiana community (xeric type), M. amurensis-U. davidiana var. japonica community (xeric type), M. amurensis-T. amurensis community (moist type), and M. amurensis-Styrax obassia community (moist type). According to the community type, trees per ha were more abundant in the area of the moist types than the xeric types. Height growth of M. amurensis increased with increasing ages until 10 years, and then decreased thereafter, especially at altitude of 1,020m. M. amurensis showed rapid early growth of height and volume, indicating possible high biomass production under enough light. Growth of M. amurensis increased greatly at about 40 years if released from severe competitions. The rotation age of natural M. amurensis stand was expected for above 50 years.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.65-76
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• 2000

Lichen flora of 'Backwoon' mountain, Korea, was investigated during the summer of 1998 and 1999 to screen out lichen species which can be used as a biomonitor for atmospheric ozone. The identified foliose or fructicose lichens in the area were classified into 9 families, 20 genera and 34 species. The dominant lichen species in the area were found to be Leptogium sp., Parmelia sp., Parmotrema sp., Phaeophyscia sp. and Cladonia sp. It was also found that lichen species showing a wide range of sensitiveness to air pollution were distributed in 'Backwoon' mountain. The Parmotrema austrosinense, P. tinctorum, Certrelia braunsiana and Ramalina yasudae collected in the area were exposed to ozone at the level of 200ppb, 8hr/day in controlled growth chamber for 2 weeks. Malondialdehyde(MDA), hydroperoxy conjugated dienes(HPCD), soluble protein content and OD435nm/OD415nm ratio for phaeophytinization of chlorophyll were measured and a pollution index(PI) was calculated for each lichen. Ozone exposure severely damaged to the lichens in the order of P. austrosinense>P. tinctorum>C. braunsiana>R. yasudae. P. austrosinens easily identified and widely distributed in Korea is likely to be a very useful biomonitor of air pollution, especially for ozone. These results indicate that Korean lichen species can be used as a biomonitor for air pollution to evaluate air quality contaminated with ozone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.988-993
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• 2012

The objective of this study was to investigate the physicochemical properties of Yukwa bases with different quantities of Soju during long-term storage. We examined Yukwa bases with 5 different quantities (0%, 25%, 50%, 75%, and 100%) (v/w) of Soju after intervals of 10 days up to 50 days at $30{\pm}1^{\circ}C$. The L and a values of all Yukwa bases decreased as storage time increased. The b value of Yukwa bases with 0% Soju increased as storage time increased, but Yukwa bases with 25~100% Soju decreased. The compression and shared force decreased as storage time increased for all subjects, but those with bases of 50% and 75% Soju changed less during storage. The acid values of all Yukwa bases increased significantly during storage. In addition, the peroxide values of all Yukwa bases significantly increased during storage time. Yukwa bases with 0% Soju showed great change of the peroxide value during long-term storage. The peroxide values of all Yukwa bases changed less as the quantity of Soju increased.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.520-528
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• 2006

Free amino acids in epidermis function as a major component of Natural Moisturizing Factor (NMF), which maintains the optimal level of water in skin even at the low humidity. In fact, the depletion of free amino acids is reported in the epidermis of atopic dermatitis, the skin condition involving dryness. As an effort searching the dietary source for improving the level of water and free amino acid in epidermis, the dietary effects of silk protein, sericin (S) and fibroin (F) on trans epidermal water loss (TEWL), and plasma and epidermal levels of free amino acids were compared in this study. Thirty of male NC/Nga mice, an animal model of atopic dermatitis, were divided into three groups: group CA as an atopic control with control diet, group S: 1% sericin diet and group F: 1% fibroin diet. Ten of male BALB/c mice were served as group C (control group) with control diet. All mice were fed on diet and water ad libitum for 10weeks. Dry skin condition was established in group CA as TEWL was increased (148.7% of group C). In parallel, epidermal level of glutamate, one of major amino acids functioning as NMF, was dramatically decreased and epidermal levels of methionine and alanine were inversely elevated. Dietary supplementation of sericin (group S) reduced TEWL at the similar level with group C and increased epidermal levels of glutamate as well as serine and glycine, the other major amino acids as NMF. Despite a marked decrease of methionine and alanine, the reduction of TEWL and epidermal levels of glutamate, serine and glycine of group F were less than of group S. Furthermore, in contrast to similar levels of other free amino acids in plasma and epidermis of group S and group C, plasma and epidermal levels of other free amino acids, specifically phenylalanine, isoleucine, cysteine and tyrosine in epidermis of group F, were significantly higher than of group C. Together, our data demonstrate that dietary supplementation of sericin is more effective at improving dry skin condition that paralleled with the normalization of free amino acids in plasma and epidermis of NC/Nga mice.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.108-114
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• 2017

The effect of 1-methylcyclopropene (1-MCP) at $1.0{\mu}L{\cdot}L^{-1}$ was compared with control and $10{\mu}L{\cdot}L^{-1}$ ethylene treatment to evaluate softening control of apple (Malus ${\times}$ domestica Borkh.) fruit for 180 days at $0.5^{\circ}C$ in the air, followed for 28 days at a room temperature. 1-MCP or 1-MCP+ethylene treatment maintained high fruit titratable acidity and firmness after 120 days during the cold storage, which was similarly observed for 28 days at a room temperature. 1-MCP treatment maintained fruit firmness more than 14 N during the cold storage and shelf-life at room temperature. Fruit surface red color was not consistently affected by the treatments during the cold storage but enhanced more than 4.0 by 1-MCP at 21- and 28-days of room temperature. Control or ethylene treatment advanced overall preceeding of fruit softening as rapid ethylene production and respiration rates at 90 days during the cold storage increased to a climacteric maximum. Therefore, pre 1-MCP-treated fruit maintained high fresh condition at a long-term low storage + approximately one month room temperature-storage under $10{\mu}L{\cdot}L^{-1}$ ethylene treatment.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.26.2-26.2
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• 2010

최근에는 차세대 조명용 후보광원인 고출력 백색 LED를 개발하기 위한 경쟁이 치열하며, 이를 위해 업체가 고심하고 있는 가장 큰 문제 중의 하나가 칩에서 발생하는 열을 어떻게 관리하는가 하는 방열의 문제이다. 따라서, LED의 가장 큰 특징인 장수명을 손해보지 않기 위해서는 칩에서 발생되고 있는 열을 외부에 확산시키기 위한 기술 개발이 필수적이다. 다양한 방열소재 중 W-Cu 복합재는 W의 낮은 열팽창계수와 Cu의 높은 열전도도로 인해 방열소재로써 유망한 소재로 주목받고 있으나, 우수한 열적 특성을 발현하기 위해서는 고치밀화를 갖는 W-Cu 복합재 제조가 우선적으로 필요하다. W-Cu 복합체는 일반적으로 액상소결법을 통해 균일한 미세조직을 얻을 수 있으나, 열팽창계수를 낮추기 위해 Cu 함량이 적어지게 되면 치밀화가 어려우며 이를 해결하기 위해 나노입자를 갖는 분말을 이용하고자 하는 연구가 많이 진행되고 있다. 본 연구에서는 W과 Cu 산화물을 이용하는 것이 구성성분끼리의 편석이 발생하지 않으며, 소결성도 우수하여 양산화에 가장 접근한 방법으로 알려져 있다. 그러나, 지금까지의 얻어진 W-Cu 복합체의 경우, 분말상태에서의 얻어진 나노입자가 승온시에 마이크로 크기로 과도한 입자성장이 일어나기 때문에 소결 후에도 나노크기를 유지하기 어려울 뿐만 아니라, 구성상끼리의 응집체가 형성된다. 본 연구에서는 액상소결후에 W 입자가 Cu 기지내에 균일하게 분산되는 동시에 나노크기의 입자를 가지는 고분산 W-Cu 소결체를 얻고자 하였다. 이를 위해 금속산화물 분말의 분쇄를 위해 효과적인 방법으로 알려진 습식상태에서의 고에너지 볼밀링을 통하여 혼합된 텅스텐과 구리 산화물 분말의 수소환원공정을 통해 얻어진 100nm 이하의 입자를 가지는 W-20wt%Cu 나노복합분말을 출발분말로 사용하였다. W-20wt%Cu 나노복합분말의 성형체를 $1050^{\circ}C-1250^{\circ}C$의 온도범위에서 소결거동을 조사하였다. 그 결과, $1100^{\circ}C$ 온도에서 이론밀도에 가까운 소결밀도를 나타내었으며, 이는 기존에 비해 $100^{\circ}C$ 정도 치밀화 온도를 낮추는 결과이다. 소결체의 미세구조 관찰결과, 소결 후 약 200nm의 텅스텐 입자가 Cu내에 균일하게 분산되어 있었다. 제조된 W-Cu 시편에 대해서는 LED 응용성을 조사하기 위해 열전도도와 열팽창계수 등을 평가하였다.