• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.386-390
• /
• 2003

To evaluate the potential capacity of mine wastes in the production of heavy metal containing acid water, samples from depths of 0, 30 and 60cm were collected and analyzed. The waste from surface showed the lowest pH which indicates the oxidation of wastes and the capacity of contamination of the area around the waste file. And the lower pH values of leachate of the wastes through the leaching tests with pH controlled water(3, 4, 5) may indicate that minerals producing the acidity still exist. Reduction of sulfur contents in wastes after the leaching test well fit to the increased contents of iron oxide.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.6
• /
• pp.2306-2310
• /
• 2010

Corrosion is a complex series of oxidation/reduction reactions between at the water-metal surfaces and materials in which the water is stored or transported. With respect to the corrosion potential of drinking water, the primary concerns include the potential presence of toxic metals, such as lead and copper; deterioration and damage to the household plumbing, and aesthetic problems such as stained laundry, and bitter taste. This study was performed to evaluate the effects of corrosion inhibitors on corrosion rates, Fe and Cu release concentration in water distribution pipes. Decrease of corrosion rates were strongly related to phosphate corrosion inhibitors. Considering that typical corrosion processes consists of a series of electrochemical reaction at the metal surface in contact with water, corrosion rates were positively correlated with Fe release.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.12 no.4
• /
• pp.25-31
• /
• 2016

In this research, to analyze the concentration of heavy metal ions in water, we tried to find the measuring time at which the faradaic electric currents flowing by the pure oxidation-reduction reaction from the pushing up mercury electrode of the stripping scan square wave voltammetry(SV+SWV) methods system becomes larger than the capacitance electric current. In order to do this, a method for analyzing signals using FPGA has been designed and we conducted 120 experiments using it. As a result, when the frequency of the square wave is 40Hz, The valid potential-current signal was measured from 96.6667% to 96.7155% of the end of the pulse of the forward and reverse, and the optimal signal was measured at 96.6667%. In addition, the experiment was carried out 40 times by changing the pulse height of the square wave from 10Mv to 40Mv. As a result, at a size smaller than 40Mv, there is little change in the magnitude of the potential-current, and an invalid signal was generated when it is out of this size.

• Food Science and Industry
• /
• v.51 no.4
• /
• pp.313-324
• /
• 2018

As excessive intake of salt is regarded as a reason for health problems, the tendency of people to attempt to reduce intake of salt in their everyday lives is on the rise. In Korea, where many people have a higher intake of salt compared to those in other countries, there have been diverse efforts to improve on this eating habit. Protein hydrolysates are chemically, physically hydrolyzed protein that have been widely utilized as a material for not only regular food but health functional food due to have diverse biological effects such as anti-oxidation, anti-inflammation, prevention of diabetes, and regulation of blood pressure. Various amino acids such as glutamic acid, arginine and arginine dipeptides, which exist in the components of protein hydrolysates, have also been recently recognized as being helpful in decreasing the use of salt in foods as they can greatly enhance salty taste when used concurrently with salt due to having both salty and palatable flavors. In the case of protein hydrolysates that decompose soy protein or fish protein such as anchovy, they could reduce consumption of salt by as much as 50% without affecting people's food preferences when applied to food as they boost salty taste by approximately 10% to 70%. Although there are only a few studies on protein hydrolysates as a salty taste enhancer or salt substitute, the results of several studies are indicative of the potential of protein hydrolysates as a salty taste enhancing ingredient.

• Journal of Applied Biological Chemistry
• /
• v.56 no.2
• /
• pp.101-107
• /
• 2013

Physicochemical properties of kochujang prepared with different concentration of turmeric were compared. The number of yeast and bacteria in the kochujang were low in the group with more than 1% of turmeric while the amylase and protease activity increased in the group with less than 1% of turmeric. The L- and b-values increased as the concentration of turmeric increased, however a-value decreased. The titratable acidity was low in the high percentage of turmeric added group. Oxidation-reduction potential increased in the later stage of fermentation with decrease in Aw. Reducing sugar and alcohol were high in than higher turmeric added group. Amino- and ammonia-type nitrogen were the highest in the 0.5% turmeric added group. The overall acceptability of kochujang was significantly more favorable (p<0.05) in the 0.25% turmeric added group than over 1% turmeric added one.

• Journal of Electrochemical Science and Technology
• /
• v.3 no.1
• /
• pp.1-13
• /
• 2012

Many researchers focus on indium contained semiconductors and alloy compounds for their various applications. Electrochemists want to obtain indium contained compounds simply via one-step electrodeposition. First of all, electrochemistry of constituent elements must be understood in order to develop the best condition for the electrodeposition of indium contained compounds. We will review the electrochemistry of indium. Equilibria between indium metal and indium ions and the standard electrode potentials of the equilibria will be reviewed. The electrochemical reactions of indium species are affected by surrounding conditions. Thus dependences of electrochemical behaviors of indium metal and indium ions on various parameters will be reviewed.

• Transactions of the Korean hydrogen and new energy society
• /
• v.11 no.4
• /
• pp.179-188
• /
• 2000

The anodic reaction of hydrogen/oxygen gas mixture at platinum or palladium electrode interfacing with a solid polymer electrolyte was investigated using AC impedance method. The impedance spectrum of the electrode reactions of the mixture depends on the gas composition, electrode roughness, the mode of electrochemical operation and the cell potential. For electrolysis mode of operation, the spectrum taken for the reaction on a rough platinum electrode for the gas mixture revealed clearly that the local anodic reduction of oxygen gas takes place concurrently with the anodic oxidation of hydrogen gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.5
• /
• pp.397-401
• /
• 2008

Most of the topic in PCB industry was about increasing the volume of product for the development of electronics in numerous industrial application area. However, it has been emerged that yield improvement quality manufacturing via detecting any suspicious process in order to minimize the scrapped product and material waste. In addition, recently, restriction of hazardous substances (RoHS) claims that electronic manufacturing environment should reduce the harmful chemicals usage, thus the importance of monitoring copper etchant and detecting any mis-processing is crucial for electronics manufacturing. In this paper, we have developed real-time chemical monitoring system using RGB sensor, which is simpler but more accurate method than commercially utilized oxidation reduction potential (ORP) technique. The developed Cu etchant monitoring system can further be utilized for copper interconnect process in future nano-semiconductor process.

• YAKHAK HOEJI
• /
• v.42 no.6
• /
• pp.583-588
• /
• 1998

These experiments were investigated effects of the cell death of glycyrrhetinic acid (GA) on transplanted-L1210 cells in BALB/c mice. The GA suppressed the proliferation of L121 0 cells in vivo and in vitro system. The administration of GA induced apoptosis of transplanted-L1210 cells via the reduction of mitochondrial transmembrane potential in mice. The GA enhanced the production of nitric oxidation in peritoneal macrophages obtained from L1210 cells-transplanted mice. The apoptosis of L1210 cells were induced by co-culture of the macrophages obtained from GA administered mice and L1210 cells in vitro, and was partly inhibited by the treatment of L-NMMA. These results suggest that GA induces the cytotoxicity and the apoptosis of transplanted-L1210 cells via the production of nitric oxide in peritoneal macrophages.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.14 no.4
• /
• pp.101-107
• /
• 2018

In the stripping scan square wave voltammetry (SV+SWV) polarography that is often used to analyze the concentration of heavy metals in water, we must measure the point where the faradic current that flows by the pure oxidation-reduction reaction at the electrode is greater than the capacitive current, the frequency cannot be too high. Therefore we wanted to find the frequency range that can be measured. In order to do this, we came up with a method to analyze the signal using FPGA Soc. With this method, the frequency of the square wave was increased from 10Hz to 400Hz by 10Hz, and the measuring time of the square wave was changed from 96.695% to 96.765% by 0.005% while 1600 experiments were conducted. As a result, the frequency of the square wave maintained a stable area of potential-current within 320Hz and it was possible to measure the potential-current signal when calculating the measuring time within the frequency range of 96.7155%.