• 한국환경과학회지
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• 제6권2호
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• pp.125-131
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• 1997

The mechanism of stomatal closing in response to $O_2$ was indirectly investigated by using $H_2O_2$ which is the intermediate product of $O_2$ metabolites. Stomata in epidermal strips close in response to $H_2O_2$. The effect of $H_2O_2$ on stomatal closing was dependent on the concentration of $H_2O_2$. 10 ppm $H_2O_2$ showed a clear effect on stomatal closing and 1000 ppm $H_2O_2$ induced complete stomatal closing after the treatment of 3 hours. Stomatal closing by $H_2O_2$ in intact leaf was also observed by measuring the diffusion resistance with porometer. It was found that the stomatal closing by $H_2O_2$ was not mediated by $Ca^{2+}$, and that was a different result observed in stomatal closing by water stress. Reversely, $Ca^{2+}$ showed a great inhibition on stomatal closing. The leakage of K+ in epidermal strips was doubled in response to $H_2O_2$ when it was campared to the control. 10 ppm $H_2O_2$ decreased photosynthetic activity. Fv/Fm representing the activity of Photosystem II was reduced about 4 % in 10 ppm $H_2O_2$ and 8 % in 100 ppm $H_2O_2$ In the treatment of 1.5 hour. However, stomatal closing by 10 ppm $H_2O_2$ was reduced about 56 %. According1y, it can be suggested that stomatal closing by $H_2O_2$ is related with the decrease of photosynthetic activity, but it was chiefly induced by the change of the membrane permeability. Key words Commelina communis, stomatal closing, $H_2O_2$, $Ca^{2+}$, photosynthesis.

• Journal of Dairy Science and Biotechnology
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• 제30권2호
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• pp.93-109
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• 2012

This study was performed to investigate the effects of added whey protein concentrates (WPC) and whey powder (WP) on the quality and shelf life of Tofu, a traditional food in Korea. Combined whey powder and whey protein concentrates were obtained at drainage after the casein was separated by using rennet enzyme or acidification of milk. We manufactured whey Tofu and evaluated its nutritional quality by testing, the general composition for yield, moisture, pH, crude protein, crude fat, carbohydrate, rheology, sensory properties, and change during storage. 1. The general compositions of WPC and WP were as follows: (a) WPC: moisture, 5.9%; crude protein, 56.2%; crude fat, 0.1%; carbohydrate, 32.6%; ash, 5.2%; and pH 5.93 and (b) WP: moisture, 3.7%; crude protein, 13.2%; crude fat, 1.6%; carbohydrate, 74.4%; ash, 7.1%; and pH, 6.65. 2. The yield of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=8:2 and (b) in WP, 2% addition was the highest (265%) at $13.3g/cm^2$, but with 4% addition WP was the lowest (184%) at $22.2g/cm^2$. 3. The moisture content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL = 6:4 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=8:2 and (b) in WP, 2% addition was the highest at 79.82% ($13.3g/cm^2$), but 4% was the lowest at 75.18% ($22.2g/cm^2$). 4. The pH of Tofu was as follows: (a) in WPC, the value was WPC 6% > WPC 4% > WPC 2% > control and $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=7:3 and (b) in WP, WP 4% > WP 2% > control. 5. The ash content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=9:1 and (b) in WP, there was no difference between 2% and 4% addition. 6. The crude protein content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=6:4 and (b) in WP, there was no difference between 2% and 4% addition. 7. The crude fat content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=9:1 > $CaCl_2$:GDL=6:4 and (b) in WP, values decreased with increasing pressed weight. 8. The carbohydrate content of Tofu was as follows: (a) in WPC, the content was $CaCl_2$:GDL=8:2 > $CaCl_2$:GDL=7:3 > $CaCl_2$:GDL=6:4 > $CaCl_2$:GDL=9:1 and (b) in WP, values increased with increasing pressed weight. 9. The rheology test results of Tofu were as follows: (a) in WPC, hardness and brittleness was highest with $CaCl_2$:GDL=8:2 and 6% added WPC. Cohesiveness was highest with $CaCl_2$:GDL=6:4 and 2% added WPC. Elasticity was the highest with $CaCl_2$:GDL=7:3 and the added WPC control. (b) in WP, hardness was the highest with $22.2g/cm^2$ and added WP control. Cohesiveness was the highest with $17.8g/cm^2$ and added WP 2%. Elasticity was the highest with $17.8g/cm^2$ and added WP 4%. Brittleness was the highest with $17.8g/cm^2$ and added WP control. 10. The sensory test results of Tofu were as follows: (a) in WPC, the texture, flavor, color, and smell were the highest with $CaCl_2$:GDL=6:4 and 6% added WPC. (b) in WP, the texture was the highest in the control with $22.2g/cm^2$. Flavor and smell were the highest in WP 2% and $22.2g/cm^2$. Color was the highest in WP 2% and $17.8g/cm^2$. 11. The quality change of Tofu during storage was as follows: (a) in WPC, after 60 h, all samples began to get spoiled and their color changed, and mold began to germinate. (b) in WP, the result was similar, but the rate of spoilage was more rapid than that in the control.

• 한국태양에너지학회 논문집
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• 제33권2호
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• pp.93-100
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• 2013

Two-step thermochemical cycle using ferrite-oxide($Fe_2O_4$) device was investigated. The $H_2O$(g) was converted into $H_2$ in the first experiment which was performed using a dish type solar thermal system. However the experiment was lasted only for 2 cycles because the metal oxide device was sintered and broken down. Another problem was that the reaction was taken place mainly on a side of the metal oxide device. The m-$ZrO_2$, which was widely known as a material preventing sintering, was applied on the metal oxide device. The ferrite loading rate and the thickness of the metal oxide device were increased from 10.67wt% to 20wt% and from 10mm to 15mm, respectively. The chemical reactor having two inlets was designed in order to supply the reactants uniformly to the metal oxide device. The second-experiment was lasted for 5 cycles, which was for 6 hours. The total amount of the $H_2$ production was 861.30ml. And cerium oxide($CeO_2$) device was used for increasing $H_2$ production rate. $CeO_2$ device had low thermal resistance, however, more $H_2$ production rate than $Fe_2O_4$ device.

• Journal of Plant Biology
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• 제37권2호
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• pp.231-236
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• 1994

분리한 시금치 엽록체에 $Cd^{2+}$을 처리하였을 때 광계 I에 비해서 광계 II의 활성이 낮은 농도의 $Cd^{2+}$에 의해 억제되었다. 그러므로 $Cd^{2+}$에 의해 1차적으로 광계 II 활성이 저해되었다는 것을 알 수 있다. 광계 II의 전자공여체인 diphenylcarbazide를 첨가했을 때 대조구에 비해 활성이 크게 증가하였다. $Cd^{2+}$ 처리시 $Mn^{2+}과\;Ca^{2+}을$ 외부에서 첨가했을 때 광계 II 활성은 회복되었지만 회복되는 정도가 15%로 낮았다. $50\;\mu\textrm{M}\;Cd^{2+}$ 처리구에서 광계 II 활성은 크게 감소하였으나 Fv/Fm는 미소하게 감소하였으며 $100\;\mu\textrm{M}\;Cd^{2+}$ 처리구에서 Fv/Fm는 크게 감소하였다. 광계 I활성은 $Cd^{2+}$의 처리 농도가 증가함에 따라 감소하였으나 세척하였을 경우 0.2 mM의 $Cd^{2+}$ 처리구에서 대조구보다 활성이 증가하였으며 농도가 높아짐에 따라 활성의 회복 정도가 컸다.

• 환경위생공학
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• 제15권4호
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• pp.26-34
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• 2000

In order to treat the dyeing wastewater, the $UV/TiO_2/H_2O_2$ system was investigated, and proper pretreatment methods were examined to reduce the load on the system considering economical and technical efficiency. The results of this study were as follows: 1. $UV/TiO_2/H_2O_2$ system with pretreatment process was adopted, the result of Chemical coagulation and pH control units was $pH{\;}11{\;}{\rightarrow}{\;}coagulation{\;}{\rightarrow}{\;}pH{\;}4$ and the optimum dosage of $FeCl_3$ was $600mg/{\ell}$. 2. Proper dosage of $TiO_2$ in the $UV/TiO_2/H_2O_2$ system with pretreatment process was $2g/{\ell}$ and $H_2O_2$ was $1000mg/{\ell}$, UV contact time was 20min to get $200mg/{\ell}$ of $COD_{Cr}$.

• 상하수도학회지
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• 제11권4호
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• pp.133-141
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• 1997

In order to treat the landfill leachate, $UV/TiO_2/H_2O_2$ system connected with biological treatment was investigated, and proper pretreatment methods were examined to reduce the load on the system considering economical and technical efficiency. It was more profitable to put $H_2O_2$ into the system in the early stage for the sample which was treated with $H_2SO_4$ to decrease alkalinity and with $FeCl_3-6H_2O$ flocculation. Because the required reaction time run up by increasing $H_2O_2$ input amount, though the COD was reduced slightly, the optimal $H_2O_2$ input amount should be determined for the desired COD and the economical efficiency. The appropriate way to get the lowest COD in the shortest time was the method to treat the sample which was controlled to pH 3.5 after adjusting to pH 12 and put 500 ppm $H_2O_2$ into the system. In that case, to increase $H_2O_2$ input amount was not profitable for the system efficiency. The sufficient photocatalytic excited time was required to reduce the photocatalytic decomposition time for the sample which was gone through the alkali state.

• 한국세라믹학회지
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• 제19권4호
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• pp.309-315
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• 1982

$FeAl_2O_4$ was formed from the starting material of $Fe_2O_3$ and $Al_2O_3$ by controlling the oxygen partial pressure using $H_2-CO_2$ gas mixture, over the temperature range of 800~120$0^{\circ}C$. The formation mechanism of $FeAl_2O_4$ was found to be a second order chemical reaction, and the activation energy of formation was observed as 39.97 kcal/mole. Vaporization behavior of $FeAl_2O_4$ under $CO_2$ atmosphere was observed over the temperature range of 800~120$0^{\circ}C$. $FeAl_2O_4$ was vaporized by a second order chemical reaction and the activation energy was found to be 21.8kcal/mole. Electrical conductivity of $FeAl_2O_4$ was also measured.

• 환경위생공학
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• 제16권4호
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• pp.62-68
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• 2001

The advantages of hydrogen peroxide dissolution method were no discharge of noxious matter when dissolution of iron wire which used as the center supporter, reactions occur in room temperature and easy to recover dissolved iron. This study was aimed at gathering the basic data of iron wire dissolution- recovery process and proposes the reaction condition of iron wire dissolution- recovery process rind the factors influencing those reactions. The results were as follows : 1 . Hydrogen peroxide dissolution method used hydrochloric acid as the catalyst. 1. In the dissolution of iron wire(1.668 g), the condition of reaction was E1702(30 ml), HCI(20 ml) and $H_2O$(200 ml) ; time of the reaction was 18 min. P.W.(Piece weight) was 7.75 mg, and C.R. was $2.34{\;}{\Omega}$ 2. In the dissolution of iron wire(1.529 g), the condition of reaction was H7O2(30 ml), HCI(20 ml) and $H_2O$(200 ml), time of the reaction was 21 min., P.W.(Piece weight) was 7.73 mg, and C.R. was $2.35{\;}{\Omega}$. Hydrogen peroxide dissolution method used sulfuric acid as the catalyst. 1. In the dissolution of iron wire(0.834 g), the condition of reaction was $H_2O$(65 ml), $H_2SO_4$(5 ml) and 1702(5 ml) ; time of the reaction was 5 min.30 sec, P.W.(Piece weight) was 7.74 mg, and C.R. was $2.33{\;}{\Omega}$ 2. In the dissolution of iron wire(1.112 g), the condition of reaction was $H_2O$(65 ml), $H_2SO_4$(5 ml) and $H_2O_2$(5 ml) ; time of the reaction was 4 min.30 sec, P.W.(Piece weight) was 7.75 mg, and C.R. was $2.33{\;}{\Omega}$. Hydrogen peroxide dissolution method used hydrochloric acid and sulfuric acid as the catalyst confirmed a clean technology, because there were not occurred a pollutant discharged in the existing method.

• 한국연초학회지
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• 제23권2호
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• pp.141-148
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• 2001

Insecticidal effect or sulfuryl fluoride ($SO_2F_2$) to cigarette beetle, Lasiodema serricorne (F.), was studied in two different containers, one was 1m$^3$(without cardboard block) and the other was 0.5m$^3$(with cardboard block). Adults and larvae were transferred into a small metal can before placed in the containers. Each can was held for 8, 24, 48, 72, and 96 hours after $SO_2F_2$(10, 20, 30, and 40 g/$\ell$) treatment. All adults were killed in an 1m$^3$container. Larval mortality was 99 to 100% when the dosage of SO$_2$F$_2$was 10 and 20 g/$\ell$. Cardboard was attached between two 0.5m$^3$ containers ; one was fumigation area and the other was insect area. SO$_2$F$_2$ penetrated cardboard within 24 hours in most trials. $SO_2F_2$could affect all adults and larvae regardless of their susceptibility. All adults were killed at 8 hours in a 0.5m$^3$ container. But low mortality of larvae was recorded at 8 hours when small dosage was treated (30% in 10 g/$\ell$, 87.2% in 20 g/$\ell$). The mortality was increased as SO$_2$F$_2$ dosage increased. Six different metals (stainless, copper, brass, aluminum, iron, and zinc) were also tested to study metal corrosion and discoloration. No corrosion and discoloration was observed in most metals treated with $SO_2F_2$.

• 복식
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• 제38권
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• pp.323-336
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• 1998

The purpose of this study was to classify the contents of self-image of college men and to investigate how clothing behavior was influenced by self-image, age, major, and the expenses of clothing. Samples were 342 male students of univer-sity in Seoul. Results of this study were following : 1. Four factors of self-image derived by factor analysis : F. 1‘mature-unmatured’;F. 2‘characteristic-ordinary’; F. 3‘conservative-open’; F. 4‘dominant-submissive’.2. 5 variables of clothing behavior were influenced by real self-image. Fashion was influenced by characteristic, open, dominant image, and the expenses of clothing. The ex-planatory power of the 4 variables was 29.3%. Aesthetics was influenced by characteristic, submissive, conservative image, the expenses of clothing, and age(R2=28.7%). Modesty was influenced by conservative and ordinary im-age(R2=6.5%). Coformity was influenced by ordinary image and the expenses of clothing (R2=5.7%). Comfort was influenced by dominant image and age(R2=5.3%). 3. 5 variables of clothing behavior were influenced by ideal self-image. Fashion was influenced by unmatured, characteristic, sub-missive image, and the expenses of clothing (R2=28.9%). Aesthetics was influenced by characteristic image, the expenses of clothing, and age(R2=23.5%). Modesty was influenced by conservative, mature, and ordinary image (R2=8.3%). Coformity was influenced by ordinary image(R2=1.9%). Comfort was influenced by mature image and age(R2=5.6%). The findings indicated that self-image had a significant effect on fashion and aesthetics, and characteristic image and conservative image were important variables that affected clothing behavior of college men.