• Journal of Food Hygiene and Safety
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• v.15 no.1
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• pp.25-29
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• 2000

General composition and microbial load of brine recycled to 6 times for Chinese cabbage salting and the quality of Kimchi using every brined cabbage were investigated. The concentration of salt(NaCl) in brine after soaking dropped 1.35-2.49% and pH of the brine changed significantly until 4 times recycling. The acidities were increased as number of recycling increased. The total viable cell count in recycled brine increased from 1.58$\times$10$^{6}$ /mL in the first soaking brine to 2.3$\times$10$^{9}$ /mL in 4th soaking brine which was highest in number. The pure soluble solid and vitamin C content in brine were accumulated to 0.93% and 0.55 mg% respectively after 6th recycling. The pH, acidity and sensory evaluation results of Kimchi prepared by Chinese cabbage salted by each brine recycled 6 times showed no significant difference. It means there is a possiblity reusing brine for salting of cabbage for the preparation of Kimchi to 6 times.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.364-369
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• 1995

Effect of two-phase culture on Mentha piperita cell growth and essential oil formation was investigated using shake flask and air-lift bioreactors. LiChroprep RP-B(RP-B) addition did not impair M. piperita cell growth, but resulted in stimulated formation of essential oils and increased ratios of extracellular oil to intracellular oil formation. However, the combined use of RP-B and chitosan elicitor was not synergistic. Volumetric productivity of essential oils in RP-B treated culture using cell-recycled air-lift bioreactor was $6.9\;\mu\textrm{g}/l{\cdot}day$ which was substantially higher than that obtainable from the control. Our results demonstrate the potential of a second phase to enhance overall productivity for M. piperita cell culture.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.316-321
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• 2016

This study developed an eco-block for grass growth using the expanded vermiculites that absorb bacteria selected considering for the high pH and dry environments and plant growth. For the developed eco-block, a fundamental properties including compressive strength gain and water absorption and ecology characteristics were tested. The selected bacteria was Bacillus alcalophilus a nd Rhodoblastus acidophilus and had high concentration of $10^9cell/mL$. The expanded vermiculite that was used for shelter of bacteria was added by 7.5% and 10% replacement of the natural aggregates by volume. The developed eco-block achieved the minimum requirements specified in SPS provision and significantly effective in reducing chemical Chemical Oxygen Demand(COD) concentration and enhancing the growth of fish and plant.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.113-120
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• 2017

HCP(Half Cell Potential) method has been widely used since it is recognized as a efficient NDT(Non Destructive Technique) for corrosion detection. This work is for an evaluation of relation between corrosion amount and measured HCP in dried condition through ICM(Impressed Current Method) for accelerating corrosion. For the work, cement mortar specimens with three w/c ratios and four cover depths are prepared, and corrosion test based on ICM is performed for 6 hours, 18 hour, and 42 hours with constant 20V of electrical charge, respectively. From the test, corrosion amount increases with reduced cover depth, increasing w/c ratio, and extended corrosion period, where corrosion amount is evaluated to linearly increases with measured HCP in dried condition. In order to evaluate corrosion amount through measured HCP, the measured HCP level is firstly determined and then corrosion amount is to be compared with measured HCP, which is evaluated to be more reasonable with higher C.O.V.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.1
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• pp.55-61
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• 2016

This paper presents the geotechnical characteristics of the soil mixed with various waste(waste soil) in the landfill. The physical and mechanical tests were conducted to find out the waste soil. The tests include the gradation, consistency tests, shear and compression and the consolidation tests using both the Rowe cell and the constant ration stress. The analyses of the test results show the waste soil belongs to the well graded sand(SW) in the laboratory and sand-gravel(SG) to fine sand(SF) in the field monitoring based on the unified classification soil system. The shear strength is increasing with increasing the shear displacement, however, the peak of the shear strength does not appear through the test and there is no distinct peak value of the strength obtained. The compression index(Cc) results in as increasing the amount of the sludge included and the compression index is proportional to the sludge included, which means more settlement is expected. The hydraulic conductivity of the waste soil ranges between $1.6{\times}10^{-5}cm/sec$ and $1.8{\times}10^{-7}cm/sec$.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.124-132
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• 2022

The corrosion potential in concrete varies greatly with exposure and concrete mix conditions. In this study, RC (Reinforcement Concrete) samples were prepared considering cover depth, chloride concentration, and W/C(water to cement) ratio as variables, and HCP(Half Cell Potential) was measured, which evaluated comparative potential between embedded steel and concrete surface. In addition, OCP(Open Circuit Potential) was measured using buried steel and CE(Counter Electrode). Agar and NaOH solution were used as ion exchange materials and Hg/HgO was used for RE(Reference Electrode), which was more sensitive to temperature than HCP. Among the influencing factors, the exposure period and chloride concentration had a relatively greater effect than cover depth and w/c ratio. Additionally, the entire measured HCP and OCP showed a clearly linear relationship with increasing cover depth and w/c ratio. Through multiple regression analysis, the relationship between HCP and OCP was quantified, and an improved correlation was obtained with temperature effect.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1277-1287
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• 2016

This study proposes a novel isolated high step-up galvanic converter, which is suitable for renewable energy applications and integrates a boost converter, a coupled inductor, a charge pump capacitor cell, and an LC snubber. The proposed converter comprises an input inductor and thus features a continuous input current, which extends the life of the renewable energy chip. Furthermore, the proposed converter can achieve a high voltage gain without an extremely large duty cycle and turn ratio of the coupled inductor by using the charge pump capacitor cell. The leakage inductance energy can be recycled to the output capacitor of the boost converter via the LC snubber and then transferred to the output load. As a result, the voltage spike can be suppressed to a low voltage level. Finally, the basic operating principles and experimental results are provided to verify the effectiveness of the proposed converter.

• Economic and Environmental Geology
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• v.51 no.4
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• pp.359-370
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• 2018

The batch and column experiments were performed to overcome the limitation of the neutralization process using the $scCO_2$-water-recycled aggregate, reducing its treatment time to 3 hour. The waste cement mortar and two kinds of recycled aggregate were used for the experiment. In the extraction batch experiment, three different types of waste mortar were reacted with water and $scCO_2$ for 1 ~ 24 hour and the pH of extracted solution from the treated waste mortar was measured to determine the minimum reaction time maintaining below 9.8 of pH. The continuous column experiment was also performed to identify the pH reduction effect of the neutralization process for the massive recycled aggregate, considering the non-equilibrium reaction in the field. Thirty five gram of waste mortar was mixed with 70 mL of distilled water in a high pressurized stainless steel cell at 100 bar and $50^{\circ}C$ for 1 ~ 24 hour as the neutralization process. The dried waste mortar was mixed with water at 150 rpm for 10 min. and the pH of water was measured for 15 days. The XRD and TG/DTA analyses for the waste mortar before and after the reaction were performed to identify the mineralogical change during the neutralization process. The acryl column (16 cm in diameter, 1 m in length) was packed with 3 hour treated (or untreated) recycled aggregate and 220 liter of distilled water was flushed down into the column. The pH and $Ca^{2+}$ concentration of the effluent from the column were measured at the certain time interval. The pH of extracted water from 3 hour treated waste mortar (10 ~ 13 mm in diameter) maintained below 9.8 (the legal limit). From XRD and TG/DTA analyses, the amount of portlandite in the waste mortar decreased after the neutralization process but the calcite was created as the secondary mineral. From the column experiment, the pH of the effluent from the column packed with 3 hour treated recycled aggregate kept below 9.8 regardless of their sizes, identifying that the recycled aggregate with 3 hour $scCO_2$ treatment can be reused in real construction sites.

• Journal of Sensor Science and Technology
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• v.9 no.1
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• pp.70-75
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• 2000

The recycled single crystal silicon wafers have been fabricated into solar cells. It can be a solution for the high cost in materials for solar cells and recycling of materials. So, p-type (100) single crystal silicon wafers with high resistivity of $10-14\;{\Omega}cm$ and the thickness of $650\;{\mu}m$ were used for the fabrication of solar cells. Optimistic conditions of formation of back surface field, surface texturing and anti-reflection coating were studied for getting high efficiency. In addition, thickness variation of solar cell was also studied for increase of efficiency. As a result, the solar cell with efficiency of 10% with a curve fill factor of 0.53 was fabricated with the wafers which have the area of $4\;cm^2$ and thickness of $300\;{\mu}m$. According to above results, recycling possibility of wasted wafers to single crystal silicon solar cells was confirmed.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.4
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• pp.43-51
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• 2009

Paper mill sludges are discharged around 870,000 M/T annually. Only 30% of the paper mill sludge have been recycled and the rest has been disposed by land fill, incineration, ocean abandonment and other ways. Because of overall prohibition of sludge disposal by London Dumping Convention in 2012, a urgent counter measure for paper mill sludge must be provided. In this paper, some basic experiments were carried out to develop a tray cell pot using paper mill sludge for increasing the recycling potential of the wasted sludge. To establish the manufacturing parameters, the tray cell pots were made with three types of materials including virgin pulp, old news paper and corrugated board mixed in a blend tank of a molding machine. The bending force and moisture content of the produced tray cell pots was measured to confirm the application capability. The tray cell pot could be manufactured under the condition of over 20% of virgin pulp, 40% of old news paper added. However, the corrugated board could not be used because of the glutinous substance included. The produced tray cell pot absorbed water very easily and the bending force decreased rapidly. The waterproof material must be used to applicate the produced tray cell pot in plant growing fields.