• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1999.11a
• /
• pp.35-39
• /
• 1999

현재 NO제거에 주로 사용되는 환원제로서 NH$_3$가 있는데 이는 NO에 대한 선택도가 우수하기 때문이다. 그러나, NH$_3$는 독성이 강하고 부식성이 있어 저장 및 수송에 많은 비용이 든다는 단점이 있다. 따라서 본 연구에서는 SOx/NOx 동시 제거 공정에 효과적으로 알려진 fresh and sulfated CuO/${\gamma}$-A1$_2$O$_3$촉매상에서 독성이 강한 NH$_3$를 대신하는 새로운 환원제로서 urea용액을 이용하여 유동층 반응기에서 SCR을 수행해 보고자 한다.(중략)

• Applied Biological Chemistry
• /
• v.37 no.5
• /
• pp.397-401
• /
• 1994

Bioreduction with active dried baker's yeast proceeded smoothly in n-hexane, pentane or petroleum ether as an organic solvent system. Ethyl(1) and octyl 3-oxohexanoate(2) were reduced to $({\underline{R}})-ethyl(3)$ and $({\underline{S}})-octyl$ 3-hyroxy-hexanoate(4) with high enantiomeric excess, respectively.

• Proceedings of the KAIS Fall Conference
• /
• 2004.06a
• /
• pp.288-290
• /
• 2004

본 연구에서는 산성전리수와 환원전리수의 미생물 제어력을 정량적으로 비교하였다. 산성전리수와 환원전리수에 병원성 미생물을 각각 시간별로 노출시킨 결과, 산성 전리수와 환원전리수 모두 미생물을 제어 할 수 있다. 특히 산성 전리수는 각종 병원성 미생물에 대하여 순간적으로 미생물을 제어하는 강력한 살균효과를 보여주었다. 이에 비해 환원전리수는 산성전리수의 강력한 미생물 제어력에는 미치지 못하기는 하지만, 시판되는 무기 항균제보다는 우수하거나 비슷한 미생물 제어력을 보여주었다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.6
• /
• pp.1041-1046
• /
• 2001

Solutions of fructose, glucose and sucrose were heated without catalyst at various temperature for different length of time. Changes in the formation of early caramelization product and browning intensity as well as pH of heated sugar solutions were determined. Reducing powers of caramelization products (CP) and their inhibitory effects on polyphenol oxidase (PPO) were also determined and their correlations were discussed. The early CP and browning intensity increased with temperature and time, in the order of heated fructose>sucrose>glucose solutions (p<0.005), while pH decreased. pHs of sugar solutions heated at 20$0^{\circ}C$ showed in the range of 3.32 ~ 3.50. Reducing power of CP as well as their inhibitory effect on PPO also increased with temperature and time, respectively. Among sugar solutions, reducing power showed the same trends as above at both 15$0^{\circ}C$ and 17$0^{\circ}C$ (p<0.001). However, those of heated fructose solutions were the highest in the early stage, while those of heated sucrose solutions were the highest in the final stage at 20$0^{\circ}C$. This is due to the difference in CP formed. Sucrose solution heated at 20$0^{\circ}C$ showed the highest inhibitory effect, reducing PPO activity by 34.6%. From these results, it is considered that the inhibitory effect of CP on PPO is partly related to their reducing power.

• Journal of agriculture & life science
• /
• v.45 no.6
• /
• pp.251-263
• /
• 2011

In order to investigate treatment effects of limestone and steel refining slag for paddy soils contaminated with arsenic and heavy metals, a lab-column test was carried out under reducing environments of flooded paddy soils. In conditions of the flooded paddy soils, at the point of time when iron and manganese were reduced and leached rapidly, heavy metals also leached rapidly, and some leachate samples from an untreated soil exceeded regulatory standards. On the contrary, all samples from soils treated with limestone 5% and steel refining slag 5% respectively were below the regulatory standards, showing much lower heavy metal concentrations than in the untreated soil. Arsenic increased continuously during the observation period according to its typical characteristics, and along with decreasing redox potential, arsenic was expected to leach as $H_3AsO_3$-of form $A^{3+}$ with high mobility and strong toxicity. Limestone and steel refining slag showed high treatment effects against heavy metals present in soil and steel refining slag especially showed the high treatment effects against arsenic.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.1
• /
• pp.24-31
• /
• 2008

Sulfate reducing bacteria (SRB) is universally distributed in the sediment, especially in marine environment. SRB reduce sulfate as electron acceptor to hydrogen sulfide in anaerobic condition. Hydrogen sulfide is reducing agent enhancing the reduction of the organic and inorganic compounds. With SRB, therefore, the degradability of organic contaminants is expected to be enhanced. Ferrous iron reduced from the ferric iron which is mainly present in sediment also renders chlorinated organic compounds to be reduced state. The objectives of this study are: 1) to investigate the reduction of TCE by hydrogen sulfide generated by tht growth of SRB, 2) to estimate the reduction of TCE by ferrous iron generated due to oxidation of hydrogen sulfide, and 3) to illuminate the interaction between SRB and ferrous iron. Mixed bacteria was cultivated from the sludge of the sewage treatment plant. Increasing hydrogen sulfide and decreasing sulfate confirmed the existence of SRB in mixed culture. Although hydrogen sulfide lonely could reduce TCE, the concentration of hydrogen sulfide produced by SRB was not sufficient to reduce TCE directly. With hematite as ferric iron, hydrogen sulfide produced by SRB was consumed to reduce ferric ion to ferrous ion and ferrous iron produced by hydrogen sulfide oxidation decreased the concentration of TCE. Tests with seawater confirmed that the activity of SRB was dependent on the carbon source concentration.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1986.12a
• /
• pp.532.1-532
• /
• 1986

유산균이 생성하는 polysaccharide 에 관한 연구의 일환으로서 L. casei YIT 9018 SKD-0007, L. bulgaricus SKD-0003, sir. faecalis SKD-1007, str. thermophilus SKD- 1005, str. thermophilus 510 SKD-1006등을 탈지유에 배양하면서 polysaccharide 생성에 의한 배양액의 점도 변화를 검토하였다. 이러한 다당류가 Antitumor로서의 활성과 제암효과를 가지며 인체내의 생리효과를 고양시킨다고 보고되어 있는바 다당류가 최대로 생성되는 조건을 찾는 것을 본 실험의 목적으로 하였다. 다당류의 생성을 측정하는 방법으로서 배지로는 10% 환원탈지유와 12% 환원전지유를 선택하였으며 Brookfield Viscometer를 사용하여 배양액의 점도를 경시적으로 측정하였다. 시험균 중에서 str. thermophilus 510 SKD-1006이 가장 높은 점도를 나타내었는데 41$^{\circ}C$ 배양 5일째에 5000 cps였고 다른균에 비해서 1000cps이상 높았다. 접종량이 증가할수록 점도도 증가하였으며 14%이상의 탈지유 농도에서는 7000cps를 나타냈다. 탈지유와 전지유 배양액 모두 의가소성 유체의 유동 양식을 나타내었는데 12% 환원전지유 배양액은 최대점도값이 2500 cps에 불과하였으며 배양 2일째에 최대점도 값에 도달하여 그 이후로 급격한 감소현상을 보였다.

• Proceedings of the KAIS Fall Conference
• /
• 2005.05a
• /
• pp.318-320
• /
• 2005

Antioxidation effect of reduced electrolyzed water, which has been known as antiaging agent has been investigated with very simple method. Antioxidation effect of the reaction of linoleic acid with oxygen has been measured and analyzed. Alkaline reduced electrolyzed waters are better effect, rather acidic oxidized electrolyzed waters accelerates oxidation reaction.

• Journal of the Korean Chemical Society
• /
• v.37 no.8
• /
• pp.744-752
• /
• 1993

Electrochemical reduction of thionyl chloride has been carried out at glassy carbon and microelectrode that modified by macrocyclic compounds. The catalyst molecules of macrocyclic compounds were adsorbed on the electrode surface and reduced thionyl chloride resulting in a generation of oxidized catalyst molecules. The concentration of catalysts and electrode immersion time were found to affect the catalyst performance strongly. Significant improvements in cell performance have been noted in terms of both exchange rate constants of up to 10 times and power densities of up to 220% at glassy carbon electrode. The diffusion coefficients obtained at carbon microelectrode were slightly different from that determined at glassy carbon electrode.

• Journal of the Korean Chemical Society
• /
• v.27 no.3
• /
• pp.194-200
• /
• 1983

Effect of metallic salts added to the ${\alpha}-Fe_2O_3-HCl\;or\;{\alpha}-Fe_2O_3-H_2SO_4$ reaction systems were investigated by colorimetric and gravimetric determinations. While reductive salts exhibited remarkably enhanced reaction rate, non-reductive salts showed inhibitive results. We supposed that the improvement of dissolution rate of ${\alpha}-Fe_2O_3$ by the addition of $FeCl_2$, a reductive salt, to the ${\alpha}-Fe_2O_3-HCl$ system can be attributed to the formation of chloro-bridge between $Fe^{3+}\;and\; Fe^{2+}$, and therefore some partial electronic charge transfer from $Fe^{2+}\;to\;Fe^{3+}$ on the surface of ${\alpha}-Fe_2O_3$ will be easily achieved through the bridged bond. The transferred charge to the surface will reduce the positive charge of initial $Fe^{3+}$, and also result to reduce the lattice energy of that site. Assuming tothat there is a linear relationship between the lattice energy change and the change of activation energy of the reaction system, the transferred partial electronic charge to $Fe^{3+}$ of ${\alpha}-Fe_2O_3$ surface was calculated to be ca. 0.36e.