• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.109-114
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• 2008

Though ethanol can theoretically generate 12 electrons during oxidation to carbon dioxide, the complete oxidation of ethanol is hard to achieve due to the strong bond between the two carbons in its molecular structure. Therefore, development of high activity catalyst for ethanol oxidation is necessary for the commercialization of direct ethanol fuel cell. In this study, some binary and ternary electrocatalysts of PtSn/C and PtSnAu/C have been synthesized and characterized. The catalysts were fabricated with modified polyol method with the amounts of 20 wt%, where the Pt : Sn ratios in the PtSn/C were 1 : 0, 4 : 1, 3 : 1, 2 : 1, 1.5 : 1, 1 : 1, 1 : 1.5 and Pt:Sn:Au ratios in the PtSnAu/C were 5 : 5 : 0, 5 : 4 : 1, 5 : 3 : 2, 5 : 2 : 3. From the XRD and TEM analysis results, the catalysts were found to have face centered cubic structure with particle size of around $1.9{\sim}2.4\;nm$. The activity in the ethanol oxidation was examined with cyclic voltammetry and the results indicated that PtSn(1.5 : 1)/C and PtSnAu(5 : 2 : 3)/C had the highest activity in each catalyst system. Further tests with single cell were performed with those catalysts. It was found that PtSn/C(1.5 : 1) exhibited the best performance while the long term stability of PtSnAu/C(5 : 2 : 3) is better than PtSn/C(1.5 : 1).

• Journal of the Korean Chemical Society
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• v.33 no.2
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• pp.192-202
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• 1989

Tetradentate schiff bases cabalt (II) complexes; Co(SED) and Co(ο-BSDT) were synthesized and these complexes allowed to reaction with dry oxygen to form oxygen adduct cobalt(III) complexes such as $[Co(o-BSDT)(DMSO)]_2O_2,\;[Co(SED)(Py)]_2O_2\;and\;[Co(o-BSDT)(Py)]_2O_2$ in DMSO and pyridine solutions. It has been found that the oxygen adduct cobalt(III) complexes have hexacoordinated octahedral configuration with tetradentate schiff base cobalt(II), DMSO or pyridine and oxygen, and the mole ratio of oxygen to cobalt(II) complexes are 1:2. The redox processes, were investigated for Co(SEDT) and Co(ο-BSD) complexes in 0.1M TEAP-DMSO and 0.1M TEAP-pyridine by cyclic voltammetry with glassy carbon electrode. As a result the redox processes of Co(II)/Co(III) and Co(II)/Co(I) found to be reversible or quasi-reversible for non uptake oxygen complexes but oxygen adduct complexes found to be irreversible processes and reaction processes of oxygen for oxygen adduct complexes are quasi-reversible process, the potential range was $E_{pc}=-0.85{\sim}-1.19V\;and\;E_{pa}=-0.74{\sim}-0.89V$.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.228-236
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• 1993

The effect of ferric ion on the reaction of CH_3$MgI with benzylbromide was investigated by determining the product ratio between cross-coupling product, ethylbenzene (A) and homocoupling product, bibenzyl (B) in the presence of ferric ion. When CH_3$MgI prepared with pure magnesium was used, the ratio of A to B was 22 to 78 and with reagent grade magnesium, the ratio became 33 to 67 indicating that metallic impurities in magnesium affect the reaction mechanism to lead less homocoupling product, B. The ratio changes became significant when ferric chloride was added in the reaction mixture in catalytic amounts and the ratio of A to B reached to 80 to 20 at maximum. The reaction in the presence of ferric ion seems to follow mainly an ionic mechanism which involves iron-benzyl bromide ${\pi}$-complex formation. The complex formation is expected to be able to enhance ionic attack of CH_3$MgI on benzyl carbon to give more A.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1061-1066
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• 2003

The present study was performed to investigate the effect of ozonation of the swine nursery building on indoor air quality and growth efficiency of the weanling piglets. Forty 21-day-old, cross-bred weanling piglets were housed in two ozonated or unozonated pens(10 males and 10 females per pen) for 3 wk alternately in a swine nursery building and this procedure was repeated three times. Ozone was generated using a commercial apparatus outside the nursery building and infused into the nursery building through a duct at a level of 0.03 ppm. Indoor concentrations of harmful gases were measured at 2-h intervals for a 24-h period per each 3-wk feeding trial. Indoor ammonia and carbon dioxide gas concentrations were reduced by the ozonation(P〈0.01) by 21% and 7%, respectively, compared with those of the control(unozonation), although hydrogen sulfide concentration was not affected by the treatment. However, the weight gain, feed intake and feed/gain of the piglets did not change due to the ozonation. Results suggest that ozonation of the swine nursery building is effective for improving the indoor air quality without affecting the production efficiency of weanling piglets.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.423-428
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• 2010

Electrostatic precipitators (ESPs) used currently in industries for removing fine particles from semiconductors have to be made of expensive anticorrosive metallic materials in order to maintain their particle-removal performance. To satisfy the economical demands of industries, a novel ESP was developed; in this ESP, the charger is made of carbon fibers and collection plates consist of PET films among which an aluminum sheet is inserted. The ESP was evaluated by changing the voltages applied to the chargers and collection plates, flow rates, and number of charging channels. KCl particles with mean diameters of 100 nm were used, and a scanning mobility particle sizer was used to measure the changes in particle number concentrations upstream and downstream of the ESP. The experimental results showed that more than 90% of the particles were removed by using the ESP containing ionizers with nine channels and 65-mm collection plates at $500\;m^3/hr$ when voltages of 7 kV and 10 kV were applied to the ionizers and collection plates, respectively.

• Journal of the Korean Chemical Society
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• v.37 no.5
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• pp.473-476
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• 1993

Dipropargyldiphenylmetane, $C_{19}H_{16}, crystallizes in a monoclinic space group $C2/_c$$ with a = 11304(3), b = 20.799(5), c = 6.622(2)${\AA}$, ${\beta} = 112.8(3)^{\circ}$, Z = 4, V = 1435.3${\AA}^3,\;F(000)\;=\;520,\;D_c\;=\;1.14g{\cdot}cm^{-3}$ and ${\mu}\;=\;0.32\;cm^{-1}$. The structure was solved by direct methods and all non-H atoms were identified in the E-map. The final refinement gave R = 0.055 from 1328 unique observed reflections with I $\geq$ -1.0 $\sigma(I).$ The molecule belongs to the point group $C_2$ of Symmetry by possessing the 2-fold axis which coincides witeh the crystallographic symmetry axis in the unit cell. The linear propargyl moiety is nearly $perpendicular(94.2)^{\circ}$ to the molecular plane of the benzene ring. The internal angle of methane carbon atoms in $108.1(1)^{\circ}$, bonding to the benzene and the propargyl moiety with the bond lengths of 1.530(2) and $1.560(2)\AA$, respectively. The shortest contant between the molecules is $3.538(2)\AA$ between C(9) and C(9) (-x, y, -1/2-z).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.2
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• pp.121-127
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• 2010

The in-furnace desulfurization technique is applied to the $O_2/CO_2$ combustion system for the carbon capture and storage (CCS) process because this combustion system does not need an additional chamber for the desulfurization. $CaCO_3$ sorbent particles, which have a wide range in size from a few nanometers to several tens of micrometers, are used for this process. In this study, an experimental system which can simulate the $O_2/CO_2$ combustion system was developed. $CaCO_3$ sorbent particles were exposed to the high temperature reactor at $1200^{\circ}C$ with various residence times (0.33-1.46 s) in air and $CO_2$ atmospheric conditions, respectively. The sorbent particles were then sampled at the inlet and outlet of the reactor and analyzed qualitatively/quantitatively using SMPS, XRD, TGA, and SEM. The results showed that the residence time and atmospheric condition in a high temperature reactor can affect the characteristics of the $CaCO_3$ sorbent particles used in the in-furnace desulfurization technique, such as the calcination rate and reaction mechanism.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.118-122
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• 2003

Oxidative stress and its consequent lipid peroxidation exert harmful effects, which have been currently involved in the generation of carbon tetrachloride (CCl₄)-induced fibrosis(cirrhosis). In this study, it was investigated whether dried extract of 田螺(Concha Cipangopaludinae; CC) has liver functional improvement, antioxidative and antifibrotic effect in rats those were induced liver fibrosis by CCl₄ administration. The female Sprague-Dawley rats were divided into 3 groups(Normal, AC, AC-CC) and were observed in 6 weeks. Except for normal group, liver fibrosis(cirrhosis) in rats were developed by CCl₄ administration(0.8 ㎖/rat/week). And the rats were treated with prepared CC(p. o. 2 ㎖/day/rat). At the time of sacrifice, the liver, kidney and spleen were weighed and the ratio of organ weight/body weight was calculated. The MDA, hyp and biochemical parameters(AST, ALT, ALP, t-bili) were measured in sera and liver tissue of rats. The strong yellow color of urine was observed in all CCl₄-treated group compared with normal group, but jaundice didn't appear in CCl₄-treated group. The mortality of CCl₄-treated group is very low(<13%) during 6 weeks of observation time. The ratio of liver/body as well as the weight of liver in CCl₄-treated rats significantly increased compared with that in normal group(p<0.001). The level of clinical parameters in sera of all liver fibrosis(cirrhosis) developed rats were significantly higher than that of normal group(p<0.001-0.05). Especially the value of BUN, ALP, t-bilirubin in AC-CC group showed 20.9%, 19.6%, 47.9% lower than that in AC group. The content of hyp in CCl₄-treated rats was significantly higher than normal group(p<0.001～<0.05), and showed 12.2% lower value in the AC-CC group than AC group(p<0.05). The production of lipid peroxidation(MDA) in sera and liver tissue significantly increased under the fibrotic(cirrhotic) condition(p<0.001～<0.05). Especially the MDA value of AC-CC group in sera significantly 46.5% decreased compared with that of AC group(p<0.05), and the MDA value of AC-CC in liver tissue showed 21.4% lower than that of AC group. Concha Cipangopaludinae can be improved hepatic function, and maybe have effect of liver protection, antioxidation and antifibrosis.

• Toxicological Research
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• v.21 no.2
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• pp.107-113
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• 2005

[ $BARODON^{(R)}$ ] is a multi-purpose, high functional alkali solution made by mixing and liquid-ionizing silicon, calcium, sodium, borax, organic carbon chemicals and silver. In this study, we have investigated the apoptotic potential and mechanistic insights of $BARODON^{(R)}$ in human gastric cancer cell line (AGS cells). In MTT assay, $BARODON^{(R)}$ reduced cell viability in AGS cells. Morphological features of apoptosis with marked cytoplasmic vacuolation and appearance of apoptotic peaks in flow cytometry were observed in AGS cells with$BARODON^{(R)}$ treatment. In addition, $BARODON^{(R)}$ induced apoptosis of stomach cancer cell is related to bax up-regulation, caspase 7 protease activation and subsequent cleavage of poly (ADP-ribose) polymerase (PARP). These results suggest that BARODON can induce the apoptosis of AGS cells through modulation of bcl-2 family and the activation of intrinsic caspase cascades, indicating that it is potentially useful as a anti-cancer agent.

• Journal of Environmental Health Sciences
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• v.7 no.1
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• pp.43-49
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• 1981

This survey was carried out for a month from Jan. 15th, 1979 to Feb, 15th, 1979 to study the sanitary environments of the "book-lending" shops (comic-book shops) in Inchon area, and the special emphasis was placed on their illumination and carbon monoxide gas, which plays an important part in the whole sanitary environment. 120 shops surveyed were chosen at random from 4 administrative districts, 30 shops from one district respectively. The results of the survey were as follows:1) The average space of the book-lending shops (63.3%) was 2.0~3.9 pyung, at 21 number of shops (17.5%) was 1.0~1.9 pyung, at 53 number of shops (10.8%) was 4.0~5.9 pyung, at 9 number of shops (7.5%) was 6.0~7.9 pyung. 2) The ages of 42.8 percent of the whole 888 customers range from 10 to 14 and those of 36.5 percent from 15 to 19, and those of 11.9 percent from 20 to 24, and 89.2 percent were male and 10.8 percent were females and the percent of spending time in shops was shown 10.2% in under 1 hr, 25.4% in 1 hr to 2 hrs, 46.5% in 2 hrs to 3 hrs and 17.8% in over 3 hrs. 3)The CO pollution was quite different by shops where the ventilator was equipped and where not equipped. In the shops equipped shown 36 shops (80.8%) and non-equipped shown 65 shops (86.7%), the pollution ratio of all the shops (120 shops) was 84.2 percent. 4) The CO Concentration of the ventilator equipped shops was shown 44.5 percent in 100~149 ppm, 150~199 ppm shown 33.3 percent and 22.2 percent was 200~250 ppm, In the non-equipped shops the CO concentration was shown 36.9 percent was 150~199 ppm and 200~250 ppm was 25.6 percent. The totally was 39.6 percent in 100~149 ppm. 5) 37.5 percent of the book-lending shops had the ventilation facilities but 62.6 percent had no ventilators. 6) The maxmum average illumination of the shops was 38.5 Lux and the minimum average illumination was 14.1 Lux, and the mean average illumination S.D. was 24.6\pm38.4. 7) 35.8 percent of the shops had the illumination of 20~29 Lux and 8.3 percent had that of more than 40 Lux. In other words 91.7 percent had the illumination of less than 40 Lux.