• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.857-871
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• 2017

The major substrates used in soilless growing media are peat moss and perlite, where peat moss is a limited and expensive natural resource. Determination of appropriate substrates based on technical and economic feasibility is the vital aspect of research and the key to success in any soilless production system. This research work was performed to evaluate different low-cost and sustainable alternative substrate as soilless growing media for horticulture plant. The objective of this study was to compare the effect of sawdust species and steam treatment, for physico-chemical properties and growth of horticultural plant. This study involves the physical and chemical characterization and growth test of four substrate (pine sawdust, oak sawdust, steamed pine sawdust and steamed oak sawdust) in order to evaluate their use as components of growing media. Steamed oak sawdust ($121^{\circ}C$, 30 min) showed adequate physical and chemical properties compared to peat moss for their use as growing media. The growing media were prepared using different mixture proportion to grow Brassica campestris L., Festuca arundinacea and Lespedeza cyrtobotrya Miq. The highest germination, stem length and leaf area of Brassica campestris L., Festuca arundinacea and Lespedeza cyrtobotrya were observed in 30 minute steamed oak sawdust mixture growing media. The steam treatment condition of sawdust used in the growing media significantly positive affected the germination, the stem length and the leaf area.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.179-182
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• 2001

The chloride volatilization method for the recovery of zirconium and removal of uranium from zirconium containing metallic wastes formed in spent fuel reprocessing was studied using the simulated alloy waste, i.e. the mixture of Zr foil and UO$_2$/U$_3$O$_{8}$ powder. When the simulated waste was heated to react with chlorine gas at 350- l00$0^{\circ}C$, the zirconium metal changed to volatile ZrCl$_4$showing high volatility ratio (Vzr) of 99%. The amount of volatilized uranium increases at higher temperatures causing lowering of decontamination factor (DF) of uranium. This is thought to be caused by the chlorination of UO$_2$ with ZrCl$_4$vapor. The highest DF value of 12.5 was obtained when the reaction temperature was 35$0^{\circ}C$. Addition of 10 vol.% oxygen gas into chlorine gas was effective for suppressing the volatilization of uranium, while the volatilization ratio of zirconium was decreased to 68% with the addition of 20 vol.% oxygen. In the case of the mixture of Zr foil and U$_3$O$_{8}$, the V value of uranium showed minimum (44%) at 40$0^{\circ}C$ with chlorine gas giving the highest DF value 24.3. When the 10 vol.% oxygen was added to chlorine gas, the V value of zirconium decreased to 82% at $600^{\circ}C$, but almost all the uranium volatilized (Vu=99%), which may be caused by the formation of volatile uranium chlorides under oxidative atmosphere.ere.

• 한국수소및신에너지학회논문집
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• 제28권3호
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• pp.238-245
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• 2017

Mg-Ni nanoparticles were synthesized by a physical vapor condensation method (DC arc-discharge) in a mixture of argon and hydrogen atmosphere, using compressed mixture of micro powders as the raw materials. The crystal phases, morphology, and microstructures of nanoparticles were analyzed by means of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It was found that the intermetallic compounds of $Mg_2Ni$ and $Mg_2Ni$ formed with existence of phases of Mg, Ni, and MgO in Mg-Ni nanoparticles. After one cycle of hydrogen absorption/desorption process (activation treatment), Mg-Ni nanoparticles exhibited excellent hydrogen absorption properties. $Mg_2Ni$ phase became the main phase by aphase transformation during the hydrogen treatments. The phenomenon of refinement of grain size in the nanoparticle was also observed after the hydrogen absorption/desorption processes, which was attributed to the effect of volume expansion/shrinkage and subsequent break of nanoparticles. Maximum hydrogen absorption contents are 1.75, 2.21 and 2.77 wt.% at 523, 573 and 623 K, respectively.

• 폴리머
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• 제25권1호
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• pp.15-24
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• 2001

본 연구에서는 불포화 폴리에스테르 수지의 글리콜 몰비에 따른 경화거동을 실험하였다. 경화과정은 Tanaka 강체진자(rigid-body pendulum)형 점탄성 모델과 differential scanning calorimetry(DSC)법을 이용하였다. 강체진자의 회전축부에 수지막을 형성하여 자유진동을 시키면 수지막의 점탄성 변화에 응답하여 pendulum의 진동주기 T 및 대수 감쇄율 ${\Delta}$가 변화한다. Pendulum의 회전축부에 있어서의 수지막의 역학적인 응답을 pendulum의 진동 운동으로 취급하고 T 및 ${\Delta}$를 이용, 수지막의 dynamic modulus(E') 및 modulus loss(E')을 구하는 계산식을 만들었다. 이 측정법과 계산식을 이용하여 불포화 폴리에스테르 수지의 경화과정에 있어서의 점탄성 변화를 추적하여 수지막의 경화성의 차이를 알 수 있었다. Neopentyl glycol(NPG)의 몰비가 증가할수록 진동주기의 감소폭 기울기에 의한 경화반응속도가 느리고, damping 값에 의한 점도값의 상승속도가 감소하는 경화거동을 고찰하였다.

• 한국초지조사료학회지
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• 제14권3호
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• pp.206-214
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• 1994

This experiment was conducted to find out the response of orchardgrass (Dactylis glomrrata L.) varieties to grazing at the condition of monocultures and mixed pastures on the field of Livestock Experiment Station at Suwon from Sep. 1989 to Oct. 1991. The varieties of orchardgrass used in this experiment were Potomac, Hallmark and Syn. No. 2 as a early maturing type, and Lidacta, Rancho and Syn. No. 10 as a late maturing type. The results obtained were as follows: I. Heading date of early maturing varieties among orchardgrass like as Potomac, Hallmark and Syn. 2 ranged from May 9 to May 14. Otherwise those of late varieties(Lidacta Rancho and Syn. 10) were between May 21 to May 25. Leaf types of early varieties were shown erect, those of late varieties were erect or semi-erect. 2. In dry matter production per ha, mixture with Rancho variety(T5) was the highest as 7.818 kg and mixture with Hallmark(T2) was the lowest as 7,013 kg. But there was not significantly different(P>0.05) among mixtures. While in monocultures, Syn. 10 variety was the highest(6.626 kglha) and Lidacta was Iowest(5,775 kg). But no difference was found(P>0.05). 3. In mean grass height after grazing, mixtures with early maturing types were higher as 9.8 cm than that of late (8.8cm), and early types were higher as 10.5cm than that of late(9.4cm) in monocultures. But there was no significant difference both mixtures and monocultures.

• 한국식품영양과학회지
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• 제12권3호
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• pp.284-288
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• 1983

Ascorbic acid (AsA)와 Catechin의 혼합용액에서 AsA의 안정성을 조사할 목적으로 각각의 농도 및 pH별 혼합용액을 조제하여 가열하는 동안 AsA와 catechin의 함량변화를 조사하였다. AsA의 손실은 각 혼합구 모두 가열 시작 10분 동안에 가장 많았으며 catechin의 혼합에 의해 촉진되었으나 혼합비율이 높은 경우가 낮은 것에 비하여 AsA의 손실은 적었다. Catechin의 손실도 가열 시작 10분 동안에 가장 컸으며 AsA의 농도가 높고 catechin의 농도가 낮을수록, AsA의 농도가 낮고 catechin의 농도가 높을수록 작았다. AsA의 안정성은 catechin의 함유비가 낮을 경우에는 pH 4pH 5>pH 6 순으로 pH 4 에서 높았다.

• 복식
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• 제59권8호
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• pp.82-96
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• 2009

The purpose of this study is to present the basic approach of producing the luxury fashion brands containing of the Korean traditional traits on the basis of traditional transformation with the modern concept, taking the 'Vivienne Tam' 2000's collections. This study has focused on its transformation of the traditional one of China, and made this as the subject of investigation. It's design characteristic could be defined as "modern interpretations of China chic", and it would be divided into two groups. The ingenious mixture of Chinese tradition into the modern chic could be concluded like these. The external characteristics is categorized in the three ways (1) the aesthetic application of the Chinese traditional patterns(dragon, water waves, peony, Japanese apricot flower, bamboo, bats, Chinese characters etc.), (2)the modern application of Chinese traditional costume details(front opening of Chipao, mandarin collar and knot buttons) and (3)the modernization of Chinese traditional technique(knotting, embroidery, beading and paper cutting). To deal with the internal characteristics, (1)the aesthetic mixture of East and West, (2)the formative expressions of the traditional view on the universe and religion are remarkable. The Chinese embodiment and the view of the universe and religion was integrated into the patterns of dragon, water waves, clouds, fire, woods, and metals. In order to afford the creative designer capable of encompassing the East and West, the teaching about the Korean tradition along with the technical and practical aspect of fashion is most important, while encouraging the professional designer to make a sophisticated ones which are attributed to the Korean tradition, and thereby come to be attractive to the world customer. The study about the Korean costumes, traditional colors, the symbolic meaning of the traditional patterns, cuttings, compositions, extending to the various kinds of myths, songs, paintings and crafts are essential for the Korean designer brand to be the global luxury brands.

• 한국표면공학회지
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• 제49권2호
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• pp.218-224
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• 2016

Thermal radiation pastes were prepared by dispersing carbon materials as fillers with a content of 1 weight percent in an acrylic resin. The kind of fillers was as follows; $25{\mu}m$ graphite, $45{\mu}m$ graphite, $15{\mu}m$ carbon nanotube(CNT), a 1:1 mixture of $25{\mu}m$ graphite and $15{\mu}m$ CNT, and a 1:1 mixture of $45{\mu}m$ graphite and $15{\mu}m$ CNT. Thermal emissivity was measured as 0.890 for the samples with graphite only, 0.893 for that with CNT only, and 0.892 for those containing both. After coating prepared pastes on a side of 0.4 mm thick aluminium plate and placing the plate over an opening of a box maintained at $92^{\circ}C$ with the coated side out, the temperatures on the uncoated side of the plates were measured. The samples containing graphite and CNT showed the lowest temperatures. The paste with mixed fillers was coated on the back side of the PCB of an LED module and thermal analysis was carried out using Thermal Transient Tester (T3ster) in a still air box. The thermal resistance of the module with coated PCB was measured as 14.34 K/W whereas that with uncoated PCB was 15.02 K/W. The structure function analysis of T3ster data revealed that the difference between junction and ambient temperatures was $13.8^{\circ}C$ for the coated case and $18.0^{\circ}C$ for the uncoated. From the infrared images of heated LED modules, the hottest-spot temperature of the module with coated PCB was lower than that of the uncoated one for a given period of LED operation.

• 한국지반공학회논문집
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• 제26권10호
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• pp.5-14
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• 2010

토사안정제를 이용한 비탈면 보강공법은 환경친화적이고 원지반의 강도증대를 통한 비탈면안정성을 확보하는 방법이다. 그러나 비탈면 보강공법으로 적용할 경우 현장토질과의 혼합에 따른 실제 강도증가 정도가 명확하지 못하고 보강효과에 대한 연구가 부족하여 현장에서 많이 적용되고 있지 못하고 있는 실정이다. 본 논문에서는 토사안정제 혼합율에 따른 지반강도증가 효과를 알아보고 수치해석을 통하여 비탈면 설계 적용시 비탈면 높이에 따른 적정 보강두께를 제시하고자 하였다. 실험결과 토사안정제 함량별로 강도증가가 차이는 있지만 대략 2.0~3.0배정도 강도가 증가 효과가 있는 것으로 나타났으며 수치해석을 통해서도 비탈면 높이에 따른 적정높이를 산정할 수 있었다. 향후 비탈면 보강목적으로 토사안정제의 활용도가 높을 것으로 판단된다.

• 펄프종이기술
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• 제46권4호
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• pp.28-36
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• 2014

We studied the green synthesis and antibacterial activity of paper coated with chitosan-silver (Ag) green nanocomposites for packaging applications. Green synthesis of Ag nanoparticles (AgNPs) was achieved by a chemical reaction involving a mixture of chitosan-silver nitrate ($AgNO_3$) in an autoclave at 15 psi, $121^{\circ}C$, for 30 min. AgNPs and their formation in chitosan was confirmed by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). As-prepared chitosan-AgNPs composite materials were coated on manila paper using Meyer rod. Surface morphology and Ag contents in coating layer were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). The mechanical properties such as tensile strength and elongation were significantly affected by coating with chitosan-AgNPs. The antibacterial test of coated paper was performed qualitatively and quantitatively against Escherichia coli (E. coli). It was shown to be effective in suppressing the growth of E. coli with increasing Ag contents on the surface of coated paper and more than 95 R (%) of antimicrobial rate was obtained at chitosan-AgNPs coated papers.