• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.11
• /
• pp.2076-2082
• /
• 2011

The goal of this paper is to find an operating conditions of the single direct ethanol fuel cell such as the cell temperature, and flow rates of ethanol and oxygen. To investigate the output characteristics, the electrical current increased from 0[A] with interval of 0.001[A] every 2[s], and the cell voltage was increased until the voltage became 0.05[V]. Related to the effect of the cell temperature, the output characteristics both voltage and power were increased upto 80[$^{\circ}C$] according to the increase of the current density, but those were decreased over that temperature. In addition, the optimal flow rate of ethanol in anode was identified as of 2[mL/min] due to the dependence of generation rate such as the hydrogen ion and electron. And the flow rate of oxygen in cathode was desirable to about 300[sccm/min], it might be affected by the chemical reaction rate of the water formation among hydrogen ion, electron, and oxygen. Consequently, the fundamental conditions were identified in this work, and it will be carried out to find the best conditions of membrane by the effect of the plasma surface treatment, and the effect of other catalysts except for a platinum.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.7
• /
• pp.738-746
• /
• 2004

Recently zinc oxide(ZnO) has emerged as one of the most promising transparent conducting films with a strong demand of low cost and high performance optoelectronic devices, ZnO film has many advantages such as high chemical and mechanical stabilities, and abundance in nature. In this paper, in order to obtain the excellent transparent conducting film with low resistivity and high optical transmittance for Plasma Display Pannel(PDP), aluminium doped zinc oxide films were deposited on Corning glass substrate by dc magnetron sputtering method. The effects of the discharge power and doping amounts of $Al_2$$O_3$ on the electrical and optical properties were investigated experimentally. Particularly in order to lower the electrical resistivity, positive and negative bias voltages were applied on the substrate, and the effect of bias voltage on the electrical properties of ZnO:Al thin film were also studied and discussed. Films with lowest resistivity of $4.3 \times 10 ^{-4} \Omega-cm$ and good transmittance of 91.46 % have been achieved for the films deposited at 1 mtorr, $400^{\circ}C$, 40 W, Al content of 2 wt% with a substrate bias of +30 V for about 800 nm in film thickness.

• Journal of Pharmaceutical Investigation
• /
• v.30 no.4
• /
• pp.283-288
• /
• 2000

The purpose of the present study was to investigate the topical bioavailability of retinol (vitamin A) after its transdermal administration. For this purpose, we developed the convenient HPLC method to measure the retinol concentration in the biological fluids such as plasma and skin tissues. The low detection limit was $0.1\;{\mu}g/ml$ using a gradient HPLC system of UV detection. The initial plasma concentration of retinol was about $20\;{\mu}g/ml$ after its i.v. bolus administration (4.32 mg/kg). The half life $(t_{1/2{\alpha}})$ in the distributive phase was 1.3 min, while retinol was slowly disappeared in the post-distributive phase. On the other hand, the maximum plasma concentration $(C_{max})$ was about 776 ng/ml after appling to rat skin at a dose of 43.2 mg/kg. Furthermore, the concentration of retinol in the skin tissues was about 600 ng/g tissue at 12 hr after its transdermal administration. In conclusion, the initial plasma concentration of retinol was comparable with the skin concentration after its cutaneous absorption, followed by being decreased with the passage of the time.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1896-1897
• /
• 2007

Medical equipment of high frequency has been presently applied to various parts of human body and novel treatment effects have been shown by it. Recently there are many cases that high frequency apparatus has been used in dermatology as the interest in beauty has been growing. Especially used in skin, blood volume is increased by keeping surface temperature of skin at around $43^{\circ}C$ and domodex folliculorum are treated by applying high electric field. It is the aspect we consider that increasing blood volume and domodex folliculorum treatment take effect on hair loss. In this study, high frequency electrotherapy apparatus was proposed to be applied to hair loss treatment. For that, human body was experimented with varying output voltage and frequency. The adjustable switching signal for treatment was obtained from 100[kHz] to 1000[kHz] by using DSP. Stable output specific was also obtained by feedback control to protect human body. The best hair growth conditions were the output voltage of 1.2[kV], the frequency of near 300[kHz] and the maximum current of 2[mA]. We apply this high frequency electrotherapy apparatus to two bald men, 46-year-old and 45-year-old. After treatment for a month they had thick and strong hair.

• Journal of the Korean Geosynthetics Society
• /
• v.16 no.2
• /
• pp.159-164
• /
• 2017

This paper presents the results of an investigation into the thermo-hydromechanical response of weathered granite soil. The effect of forced change temperature and relative humidity at the soil layer boundaries were monitored during heating. A series of load settlement test were performed on layers of compacted, unsatureated weathered granite soil with geosynthetic embedded at mid height before and after application of heat exchanger to the base of the soil layers. The results from this study indicated the potential for using embedded heat exchangers for the mechanical improvement of geotechnical systems incorporating weathered granite soil.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.123-126
• /
• 2005

Eye Glass Display (EGD) with microdisplay to realize the virtual display can make the large screen, so virtual image has been developed by using microdisplay panel. This paper shows study of low cost lens design and simulation for microdisplay system with 0.6"LCoS panel. Lens design optimized consider to spherical aberration, astigmatism, distortion, and chromatic aberration. Code V is used and it designed an aspheric lens about exit pupil 6mm, eye relief 20mm and 35 degree of field of view (FOV). With the application this aspheric lens to liquid crystal on silicon (LCOS) type's microdisplay, virtual image showed 50 inch at 2m. One side of the aspheric lens was constituted from diffractive optical element (DOE) for the improvement in a performance. It had less than 2.5% of distortion value and modulation transfer function in axial had 20% of resolution with 32 lp/mm spatial frequency. The optical system is suitable for display of 15.6 mm-diagonal with SVGA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.174-175
• /
• 2007

A programmable metallization cell (PMC) memory structure with copper-saturated GeTe solid electrolyte films doped by nitrogen was prepared on a TiW bottom electrode by a co-sputtering technique at room temperature. The $Ge_{45}Te_{55}$ solid electrolyte films deposited with various $N_2$/Ar flow ratios showed an increase of crystallization temperature and especially, the electrolyte films deposited at $N_2$/Ar ratios above 30% showed a crystallization temperature above $400^{\circ}C$, resulting in surviving in a back-end process in semiconductor memory devices. The device with a 200 nm thick $Cu_{1-x}(Ge_{45}Te_{55})_x$ electrolyte switches at 1 V from an "off " state resistance, $R_{off}$, close to $10^5$ to an "on" resistance state, Ron, more than 20rders of magnitude lower for this programming current.

• Journal of Plant Biotechnology
• /
• v.5 no.2
• /
• pp.107-113
• /
• 2003

The effect of sodium sulphate on shoot induction and multiple shoot formation from nodal explants of Vitex negundo L. was tested on Murashige and Skoog's (MS) medium fortified with different auxins, cytokinins and sucrose. Highest percentage $(97.78\%)$ of explants for shoot induction and multiple shoot (20.68/explant) production were observed in the combination treatment of $N^6-Benzyl$ adenine (BA) $(17.80\;{\mu}M/L)$, ${\alpha}-Naphthalene$ acetic acid (NAA) $(2.15\;{\mu}M/L)$ and $5\%$ sucrose supplemented with 100 mg/L sodium sulphate. In vitro raised shoots were rooted on the half-strength MS medium fortified with different concentrations of NAA, Indole-3-acetic acid (IAA), and Indole-3-butyric acid (IBA) alone and in combinations. Among the treatments, $4.90\;{\mu}M/L$ of IBA was found most effective $(95.56\%)$ in inducing roots. The rooted plantlets were shifted to glasshouse for acclimatization and later transferred to the field with cent percent survival. Furthermore, in vitro flowering was observed in the shoots cultured on MS medium supplemented with BA $(8.90\;{mu}M/L)$ and NAA $(1.61\;{\mu}M/L)$.

• Journal of Oriental Neuropsychiatry
• /
• v.3 no.2
• /
• pp.97-106
• /
• 1992

The literature which was written about manual technique of 'Four method of conducting the Qi(氣)'suggest the following results. 1. Four method of conducting the Qi(氣) is a total method based on the basic manual method, lifing and thrusting, twisting and rotating(捻轉), timing the insertion and withdrawal(呼吸) ect. 2) Cheongryongphami method(靑龍擺尾法) come to understanding channels and conducting and Qi(氣), Paekhoyodu method(白虎搖頭法) using a channels understanding and Qi(氣) introducing, Changkuthamhyeol method(蒼龜探穴法) using a channels understanding, Ceokpongyeongweon method(赤鳳迎源法) using a collaterals understanding. 3) Cheongryongphami(靑龍擺尾) and Changkuthamhyeol method(蒼龜探穴法) were used on disease like insufficiency symptom-complex(盧證), Paekhoyodu(白虎搖頭) and Ceokpongyeongweon method(赤鳳迎源法) were used on excessivess symptom-complex(實證) of pathogenic factors selectively. But all of them often used on C.V.A. 4) The Yang Channel's points, under the elbow and knee point, are often used as points which are used in "Four method of conducting the Qi(氣), and the Yin, Ren(任) Du(督) channels are used less than the former. 5) The manual techniques of 'Four method of conducting the Qi(氣)' are often used in clinically. "Four method of conducting the Qi(氣)"has been studies as above, but there weren't a lot of literature which is about total manual technique of acupuncture. So there is a need study about it.

• Food Science and Biotechnology
• /
• v.15 no.4
• /
• pp.564-571
• /
• 2006

In order to improve the quality and preservation of nabakkimchi, omija was added as an ingredient to determine its effect on the physicochemical characteristics of kimchi during fermentation, as well as the optimum level of omija extract. Omija extract was prepared from omija seeds by extraction with water for 9 hr at room temperature in concentrations (w/v) of 0.5, 1.0, 1.5, and 2.0% for use as an ingredient in nabakkimchi. The physicochemical characteristics of nabakkimchi containing omija extract were analyzed during fermentation of the product for up to 25 days. Delayed fermentation was observed, particularly in the early stage of fermentation, and was dependent on the concentration of the omija extract, as shown by stabilization of pH decreases and increases in the total acidity. An increased concentration of omija extract also raised the initial total vitamin C content and the reducing sugar content, which both then stabilized thereafter. Delayed development of turbidity within the optimum fermentation period of 16 days, increased redness and total color difference, and an electron-donor effect were also promoted by the omija extract. However, the omija extract also triggered extra tannin production, which leads to an astringent taste, especially at the 1.5 and 2.0% treatment levels.