• Textile Coloration and Finishing
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• v.1 no.1
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• pp.7-18
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• 1989

The distinguishing characteristic of the glow discharge is that chemical reaction induced by partially ionized gases are limited only to the substrate surface. Most studies have been done on the plasma etching and polymerization. The graft polymerization in vapour phase by cold plasma has been rarely investigated. In this study the system of tub3ar reaction chamber with capacitively coupled electrode of alternative current of 60 Hz was employed for the graft polymerization. The graft polymerization of Acylic Acid(AA) onto the poly (ethylene terephthalate) (PET) was carried out by treatment of PET film and fabric by cold plasma (glow discharge of argon gas), followed by the supply of AA vapour. The graft yield was about 1 wt%. The surface property was determined by contact angle, the surface tension was evaluated by zisman’s plot and equation of surface tension mesurement. The results were as follows: 1. In order to obtain lower contact angle, it was effective to avoid the vicinity of electrodes for a setting position of substrate. 2. Contact angle affected on the monomer pressure and its duration of exposure to the acid vapour. 3. Polymer radical formation was influenced by the changes of the value of current density and plasma treatment time. 4. Total surface tension of plasma grafted PET film increased. With an increase in the carboxylic acid content, the dispersion force decreased, while, the polar force and hydrogen bonding force increased. 5. The contact angle decreased from $75^\circ$ to around $30^\circ$ by plasma grafting. There was no ageing effect on the contact angle after 4 months.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.40-46
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• 2007

A laboratory scale experiment on phenol conversion properties by pulsed corona discharge process was carried out. Effects of operating parameters such as applied voltage, input oxygen, and electrode geometry on phenol conversion and solution properties were investigated. Electrical discharges generated in liquid phase increased the liquid temperature by heat transfer from current flow, decreased the pH value by producing various organic acids from phenol degradation, and increased conductivity by generating charge carriers and organic acids. The oxygen supply enhanced the phenol conversion through the ozone generation dissolution and the production of OH radicals. Series type electrode configuration induced more ozone production than reference type configuration because it produced gas phase discharges as well as liquid phase discharges. Therefore, the higher phenol conversion and TOC(total organic carbon) removal efficiency were obtained in series type configuration.

• ALGAE
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• v.21 no.1
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• pp.109-124
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• 2006

Responses to various types of mechanically induced wounding were followed in the giant-celled Caulerpalean species, Derbesia tenuissima, using time-lapse video-microscopy. Gametophyte vesicle cells. Puncture wounding: the gametophyte cell seals the puncture in 5 min. This is followed by cycles of ruptures and sealing, ending with full recovery in 24 hrs. Cut wounding: the protoplast immediately retracts away from the wall and reforms an intact, deflated protoplast that expands to fill the original cell within 21 hrs. Crush wounding (internal). When retained within the cell wall many protoplast fragments condense, round up, and coalesce; the reconstituted protoplast expands until it attains complete recovery, filling the original cell shape in 12 hrs. Crush wounding (external). Protoplast fragments extruded from the crushed cell are more numerous and smaller taking longer to recover. Most fragments become spherical, transforming into small viable cells capable of reproduction in several days. Sporophyte filaments. Crush wounding creates many small fragments that initially condense, coalesce and then expand within the wall to restore a complete filament with normal cytoplasmic streaming within 5 hrs. Reproduction: gametophyte. Our culture isolates produce more females than males (30:1). Gametangia develop one day before discharge that occurs explosively (1/6 sec) at first morning light. The vesicle cell forms successive gametangia every 14 days. Sporophyte. Each sporangium develops on a lateral branch that becomes isolated by the creation of successive basal plugs. After cytoplasmic cleavage and differentiation the stephanokont spores are discharged. The spores settle quickly and germinate forming gametophyte cells.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.295-302
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• 2009

The flow in the draft tube cone of Francis turbines operated at partial discharge is a complex hydrodynamic phenomenon where an incoming steady axisymmetric swirling flow evolves into a three-dimensional unsteady flow field with precessing helical vortex (also called vortex rope) and associated pressure fluctuations. The paper addresses the following fundamental question: is it possible to compute the circumferentially averaged flow field induced by the precessing vortex rope by using an axisymmetric turbulent swirling flow model? In other words, instead of averaging the measured or computed 3D velocity and pressure fields we would like to solve directly the circumferentially averaged governing equations. As a result, one could use a 2D axi-symmetric model instead of the full 3D flow simulation, with huge savings in both computing time and resources. In order to answer this question we first compute the axisymmetric turbulent swirling flow using available solvers by introducing a stagnant region model (SRM), essentially enforcing a unidirectional circumferentially averaged meridian flow as suggested by the experimental data. Numerical results obtained with both models are compared against measured axial and circumferential velocity profiles, as well as for the vortex rope location. Although the circumferentially averaged flow field cannot capture the unsteadiness of the 3D flow, it can be reliably used for further stability analysis, as well as for assessing and optimizing various techniques to stabilize the swirling flow. In particular, the methodology presented and validated in this paper is particularly useful in optimizing the blade design in order to reduce the stagnant region extent, thus mitigating the vortex rope and expending the operating range for Francis turbines.

• Journal of the Korea Fashion and Costume Design Association
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• v.11 no.1
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• pp.43-51
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• 2009

The cotton, wool, cotton/wool blended(80:20) and tencel fabrics were treated with low temperature oxygen or argon plasma, enzymes(cellulase or protease), or oxygen plasma-enzyme and examined for their weight loss and conditions for treatment for the environment friendly finishing. In the plasma treatment argon gas had better effect on the weight loss than oxygen gas did and the weight loss of all the fabrics was increased as increasing discharge power and discharge time. The weight loss of cotton, wool, cotton/wool blended(80:20) fabrics decreased in a large measure after 1 hr but that of tencel didn't decrease after 1 hr. In case of cellulose fibers oxygen gas plasma induced chemical functional groups on the surface of substrate more than argon gas plasma did so the weight loss of wool was larger than that of cotton, tencel fabrics in oxygen plasma-enzyme treatment. The weight loss of cotton and tencel fabrics decreased the initial stage because oxygen plasma pre-treatment caused cross linking as well as etching effect but argon plasma pre-treatment didn't. The plasma pre-treatment cleared the way for enzyme treatment on the whole but oxygen plasma pre-treatment bear in hand the increase of weight loss more or less because of the cross linking on the surface of cellulose fibers. The appropriate conditions for plasma treatment was 10-1Torr, 40W for 30minutes and for cellulase treatment were enzyme concentration of $3g/{\ell}$, pH 5, $60^{\circ}C$ for 1hr and for protease treatment were enzyme concentration of $4g/{\ell}$ pH 8, $60^{\circ}C$ for 1hr.

• Korean Journal of Acupuncture
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• v.26 no.3
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• pp.27-42
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• 2009

Objectives : The vestibular system detects head movement and serve to regulate and maintain the equilibrium and orientation of the body. It is known that the vestibular imbalance leads to vestibular symptoms such as nausea, vomiting, vertigo and postural disturbance. The objectives of the present study were to examine a modification of the dynamic activities of medial vestibular nucleus (MVN) neurons following electroacupuncture (EA) of GB43 (Hyepgye). Methods : In Sprague-Dawley rats weighing $250{\sim}300g$, dynamic responses induced by sinusoidal whole body rotation about vertical axis at 0.2 Hz were observed in MVN of rats during EA of GB43 (Hyepgye) with 0.2 ms, 40 Hz and $600{\pm}200{\mu}A$. Also, expression of cFos protein was observed 2 hours after EA for 30 mins. Results : In dynamic response of vestibular neuron, the excitatory or inhibitory responses of gain were predominant in the ipsilateral MVN neurons during EA but not predominant in the contralateral MVN. Most neurons showing decreased gain were classified to inhibitory responses of spontaneous firing discharge during EA and ones showing increased gain were classified to excitatory response of spontaneous firing discharge during EA. Also, EA of the left GB43 (Hyepgye) for 30 mins produced the expression of cFos protein in MVN, inferior olive (IO) and solitary tract nuclei (SOL). Spatial expressions of cFos protein were predominant in the contralateral MVN, ipsilateral IO and bilateral SOL. Conclusion : These results suggest that the excitability of MVN neurons was influenced by EA of GB43 (Hyepgye) and EA may be related to the convergence on MVN.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3109-3114
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• 2010

Flexible composite films of $V_2O_5$ and conductive polypyrrole ($V_2O_5$/PPy) were grown by facile electrochemical polymerization, wherein an anodization potential was applied to the substrate electrode in an electrolyte solution containing pyrrole monomer and dispersed $V_2O_5$ particles. The coating of polypyrrole (PPy) on the surface of $V_2O_5$ particles was induced by the oxidative catalytic action of $V_2O_5$ during the electrochemical polymerization of pyrrole. PPy in the composite film connects the isolated $V_2O_5$ particles. This results in the formation of conductive networks in the composite film cathode, thereby enhancing the Li+ ion diffusion to the surface of the isolated $V_2O_5$ particles and thus increasing the accessibility of the $Li^+$ ions. The specific capacity tests of the Li rechargeable batteries revealed that the discharge capacity of this composite film cathode was higher, i.e., $497\;mAhg^{-1}$, than that of $V_2O_5$/PPy powder or pristine $V_2O_5$.

• Journal of the Optical Society of Korea
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• v.13 no.4
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• pp.428-433
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• 2009

A photonic crystal fiber with two large air holes outside the holey cladding region is fabricated to induce an effective long periodic grating (LPG) in the core by an electric arc discharge. We believe that the two large air holes lead to the asymmetric perturbation in the core under the electric arc discharge, thereby introducing the coupling to the first higher-order mode. The transmission characteristics of the PCF with the LPG for the external perturbation such as strain, curvature, and temperature are also investigated. It was found that the shift of resonance peak in the transmission spectrum depends on the bending direction. The curvature of 8.55 $m^{-1}$ results in the center wavelength shifts of 1.8, 4.3, and 11 nm for a vertical, diagonal, and horizontal direction of the curvature to the large air-hole alignment, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.553-553
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• 2013

상압 플라즈마 기술은 표면처리, 온존 발생장치, VOC (Volatile Organic compound) 제거등 다양한 산업분야에서 응용되고 있다. 상압플라즈마 기술 또한 DBD (Dielectric barrier discharge), Griding Arc, SDIP (Surface Discharge Induced Plasma) 등 다양한 기술들이 개발되어져 왔다. VOC를 제거하기 위한 다양한 플라즈마 기술중 특히 BDB 방법과 SDIP 기술들은 플라즈마에 의한 VOC 분해 뿐만 아니라 오존 발생을 통하여 VOC성분을 분해하는 것으로 알려져 있으며 효율이 매우 뛰어난 것으로 보고 되고 있다. 그러나 BDB 방전의 경우 방전이 발생하는 간격이 매우 작아 공기를 정화시키기 위해 좁은 유로를 통하여 일정넓이를 이동하여하 하기 때문에 압력감소가 심하며 이를 개선하기위해 다단으로 설계할 경우 구조가 복잡하고 가격이 고가인 단점이 있다. 본 연구에서는 두 개의 면 전극이 마주보는 형태로 된 DBD 구조의 단점을 보완하기 위하여 빗살무늬 모양의 다층구조의 선형전극으로 구조를 변화시켜 전극에 의한 압력감소를 방지하고 효율적으로 플라즈마 및 오존을 발생시킬 수 있는 VOC제거용 상압 플라즈마 발생장치를 개발하였다. 또한 플라즈마 발생 및 오존발생량이 우수한 것으로 알려져 있는 SDIP 장치 또한 제작하여 비교 평가를 하였다. 제작된 플라즈마 발생장치는 60 Hz와 20kHz의 교류 고압파워 서플라이를 이용하여 플라즈마 발생실험을 진행하였다. 선행 연구에서는 60 Hz의 고압 파워 서플라이를 이용하여도 플라즈마 방전이 잘 된다고 보고되었는데 본 실험에서 60 Hz 파워 서플라이를 사용할 경우 15 kV 이상이 인가될 때 아주 약하게 오존이 발생하는 현상이 관찰되었으나 육안으로 구분이 될 만큼의 플라즈마 방전은 발생하지 않았다. 20kHz의 고압파워 서플라이를 사용한 경우에는 비교적 낮은 전압인 7 kV에서 방전이 관찰되었으며 분당 22 mg의 오존이 발생하였다. SDIP를 이용한 경우 플라즈마가 발생하는 조건은 SDIP의 기하학적 형상에 많이 의존하게 된다. 본 실험에 SDIP 장치는 매우 낮은 전압에서 방전을 시작하였다. 기존의 DBD와는 다르게 1.7 kV에서 플라즈마 발생하였으며 1.8 kV에서 정상적인 플라즈마 방전이 발생하였다. 이때 분당 3.1 mg의 오존이 발생하였다. 오존 발생양은 앞에 빗살형 플라즈마 방전장치에 비하여 낮은데 인가되는 전력을 고려하면 입력된 전기 에너지당 오존발생양은 비슷한 수준이였다.

• Tuberculosis and Respiratory Diseases
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• v.62 no.2
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• pp.125-128
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• 2007

Docetaxel is a taxoid antineoplastic drug, which is widely used to treat locally advanced or metastatic non-small cell lung cancer (NSCLC). Among the adverse dermatological reactions, nail disorders such as bending, onycholysis, hypoor hyperpigmentation are rare. We report a case of a 62-year-old male with advanced NSCLC (cT4N3M1, stage IV), who developed purulent discharge and onycholysis in the nail of all his fingers and the left great toe after five courses of anti-neoplastic chemotherapy, which included docetaxel (cumulative dose: $370mg/m^2$, 590 mg). Seven days after the final session of chemotherapy, the patient had become aware of discoloration and swelling of the nail beds with out pain. Three days later, greenish-yellow purulent discharge oozed out from the involved nails. Microbiologic studies revealed Pseudomonas aeruginosa. Intravenous and topical antibiotics (mupirocin) were applied. After 2 weeks, regrown nails were observed and the onycholysis had improved.