• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.8
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• pp.1130-1138
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• 2013

We examined dyeing properties using cotton, Tencel, general nylon 66 and hollow nylon 66 treated with aqueous and ethanol extracts without mordant. The antimicrobial properties of fabrics treated with Artemisia extracts against gram positive Staphylococcus aureus (S. aureus) and gram negative Klebsiella pneumonia (K. pneumonia) were also examined. The dying solution concentrations were determined from a calibration curve of the concentration and absorbance of Artemisia extracts. FTIR spectra confirmed that antimicrobial components and colorants (such as 1,8-cineol, thujone, caffeoylquinic acid and chlorophyll) were more present in ethanol extract than in aqueous extract. Nylons had higher $a^*$ and $b^*$, and lower $L^*$ values than cellulose fabrics dyed with aqueous solutions of Artemisia extracts; however, the dyed nylon fabrics were brown. Fabrics dyed with ethanol-extract added solutions were greener and had higher antimicrobial properties than those dyed with aqueous solutions; however, they faded and lost their antimicrobial properties after laundering. Fabrics regained their antimicrobial properties (especially against S. aureus) by the spraying of Artemisia ethanol extract; therefore, the application of Artemisia ethanol extract onto underwear is expected to relieve atopic dermatitis.

• Journal of the Korean Society of Combustion
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• v.9 no.1
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• pp.18-24
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• 2004

Synthesis of carbon nanomaterials on a metal substrate by an ethylene fueled inverse diffusion flame was illustrated. Two stainless steel plates coated with $Ni(NO_3){_2}$ were folded with each other and used as a catalytic metal substrate. Carbon nanotubes and nanofibers with diameters of 20 - 60nm were found on the substrate. From the TEM-EDS analyses, most of the nanomaterials turned out to be Nicatalyzed. Carbon nanotubes were formed on the substrate in the region ranging from about 1,400K to 900K. The formation mechanisms of nanotubes and nanofibers were similar. The synthesis temperature of the nanofibers was lower than that of the nanotubes. The higher synthesis temperature of nanotubes might enhance the activity of the catalyst metal and produce more condensed carbons. The accumulated graphite layers led to form compartments to release the compressive stress in the layers. The growth of carbon nanotubes was bamboo-shaped showing compartments in the inside hollow. The distances between those compartments represented the growth rate that depended on the synthesis temperature.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1193-1198
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• 2011

Encapsulation of biological material in the permiselective membrane allows to construct a system separating cells from their products, which may find biotechnological as well as biomedical applications in biological processes regulation. Application of a permiselective membrane allows avoiding an attack of the implanted microorganisms on the host. Our aim was to evaluate the performance of Bacillus subtilis encapsulated in an elaborate membrane system producing listeriolysin O, a cytolysin from Listeria monocytogenes, with chosen eukaryotic cells for future application in anticancer treatment. The system of encapsulating in membrane live Bacillus subtilis BR1-S secreting listeriolysin O was proven to exert the effective cytotoxic activity on eukaryotic cells. Interestingly, listeriolysin O showed selective cytotoxic activity on eukaryotic cells: more human leukemia Jurkat T cells were killed than human chronic lymphocytic B cells leukemia at similar conditions in vitro. This system of encapsulated B. subtilis, continuously releasing bacterial products, may affect selectively different types of cells and may have future application in local anticancer treatment.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.142-143
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• 2007

A 1MW class HTS(High-Temperature Superconducting) synchronous motor has been developed. This motor is aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field coil of the developed motor is cooled by way of Neon thermosiphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes performance test results of our motor, which was conducted at steady state in generator mode and motor mode.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1532-1533
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• 2007

Hollow형 미세바늘 어레이는 주사기와 패치의 장점을 결합하여 여러 종류의 약물을 통증 없이, 전달할 수 있게 한다. 본 논문에서는 건식 식각 방법과 습식 식각 방법을 이용하여 hollow형 실리콘 미세바늘 어레이를 제작하는 제작 공정과 그 결과를 제시하였다. 미세바늘 어레이의 형태는 실리콘 웨이퍼의 앞면에서 세 번의 식각 공정을 이용해 제작되었는데, 첫 번째 건식 식각 공정으로 피부에의 침투를 원활히 하기 위해 바늘 끝을 형성하고, 두 번째 건식 식각 공정으로 바늘의 길이를 조절하며, 마지막 HNA solution을 이용한 습식 식각 공정으로 바늘을 더 가늘게 만들면서 끝을 더 날카롭게 식각한다. 바늘을 통해 약물전달이 가능하도록 웨이퍼의 뒷면으로부터 건식 식각 공정을 이용해 약물 주입통로를 형성하였다. 제작된 Hollow형 실리콘 미세바늘 어레이는 $170\;{\mu}m$의 너비와 $230\;{\mu}m$의 길이, 직경 $40\;{\mu}m$의 약물 주입통로를 가지고 있으며, $1\;cm^2$의 시편 위에 $1000\;{\mu}m$의 피치로 $9{\times}9$ 개의 바늘을 형성하였다.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.46-47
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• 2002

최근 액정을 주입한 속이 빈 광섬유(Hollow fiber)와 주기적인 전극을 이용하여 전기적으로 제어 가능한 장주기 격자에 대해서 보고된 바 있다. 액정의 중요한 특성 중의 하나는 그 광축이 외부의 전기장에 의해 동적으로 재배열된다는 점이다. 또한 액정은 광축에 따라 굴절률이 다른 비등방성 물질이기 때문에 광축의 배열에 따라, 그리고 입사하는 빛의 편광에 따라 그 빛이 느끼는 굴절률이 달라지게 된다. 본 논문에서는 입사하는 빛의 편광에 따른 액정 장주기 광섬유 격자의 특성에 대해 연구하였다. 주기적인 전극의 길이는 3 cm이고 주기는 500 ${\mu}m$ 이다. 액정을 주입한 속이 빈 광섬유의 길이는 15 mm 이다. 입사하는 빛이 이상(extraordinary) 편광 상태일 때 약 6 dB 의 투과 손실을 나타냈으며 그 대역폭은 약 15 nm 이었다. 이 때 외부에서 인가한 전압은 150 V 였다. 입사하는 빛이 정상(ordinary) 편광 상태일 때에는 액정의 유효 굴절률이 외부 전기장에 대해 변하지 않기 때문에 장주기 투과 특성을 얻을 수 없었다.

• Journal of Korean Society of Steel Construction
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• v.26 no.1
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• pp.31-42
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• 2014

In this paper, concrete-filled steel tubular columns encased with precast reinforced concrete were studied. Four eccentrically loaded columns and a concentrically loaded column were tested to investigate the axial load-carrying capacity. The test parameters were the use of fiber reinforcement for cover concrete, eccentricity, column length, and lateral reinforcement. The maximum axial loads of the specimens agreed with the nominal strengths predicted by KBC 2009. However, in some specimens, the load carrying capacity quickly decreased after the peak strength due to spalling of the cover concrete.

• Membrane Journal
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• v.11 no.4
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• pp.152-160
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• 2001

The pretreatment for COD removal of acrylic wastewater and separation characteristics of ultrafiltration hollow fiber type module and reverse osmosis spiral wound type module with the variation of applied pressure and temperature were discussed. Thc optimum washing time of membranes was decided with long team operation and the degree of fouling was discussed with operating time. Permeate flux was decreased rapidly at 14 hrs and that of reverse osmosis membrane was indicated similarly. CaO find sand filter for the first step, neutralization process with treated acrylic wastewater as the second step, UF/RO processes were used as final strep. It was shown treat COD and TDS were below allowable discharge value with the result.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.445-445
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• 2010

전자빔 플라즈마는 전자 소스 부분, 전자 가속 부분, 전자빔 플라즈마 생성 부분으로 구성되어 있다. Hollow cathode형태의 전극과 anode역할을 하는 안쪽 그리드로 DC방전을 일으켜 전자를 발생시키고 안쪽 그리드와 바깥쪽 그리드 사이의 전압차이로 전자를 가속시킨다. 가속된 전자는 중성 가스와 비탄성 충돌을 하게 되어 플라즈마가 생성이 된다. 이러한 방식으로 생성된 전자빔 플라즈마는 플라즈마 형성 공간에 전기장이 없어 전자가 에너지를 얻을 수 없으며, 중성가스와 비탄성 충돌로 인해 에너지를 쉽게 잃기 때문에 전자 온도가 낮게 유지가 된다. 일반적으로 바깥쪽 그리드는 접지를 시켜 전자빔 플라즈마를 발생시키지만, DC 전원을 연결하여 양의 전압을 걸어주면 전자빔 플라즈마의 밀도는 크게 변하지 않고 전자 온도가 급격히 상승하게 된다. Ar 전자빔 플라즈마의 경우 바깥쪽 그리드가 접지에 연결되었을 경우 전자 온도는 0.5eV 정도인 것에 비해 바깥쪽 그리드에 20V DC전압을 걸어주면 전자 온도가 1eV 정도로 크게 증가를 한다. 그 이유는 바깥쪽 그리드 전압의 영향으로 전자빔 플라즈마 전위가 상승하게 되고 그 결과 높은 에너지를 가진 전자가 플라즈마 전위에 갇히게 되기 때문이다.

• Transactions of Materials Processing
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• v.11 no.6
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• pp.495-502
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• 2002

The welding pressure in extru bending process is affected by the shape of welding chamber of porthole die. It is very important to increase the welding pressure when the tube should be extruded particulary from four billets of the materials. The high circumferential stress of the tube can make the welding pressure increase during the extru-bending. In order to increase the circumferential stress, it is necessary to make the billets pass through the narrow gap between the conical die and the conical plug. This paper describes the welding pressure by the experiments and the analysis with the two types of the chamber. One of them is the chamber between the flat die and straight mandrel, and the other one is the chamber between the conical die and conical plug. The results of the experiments and the analysis shows that the conical chamber makes the welding pressure increase by the effect of the reducing diameter of tube and the welding pressure by the conical dic and plug is stronger than the welding pressure by the flat die and straight mandrel.