• Clean Technology
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• v.22 no.4
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• pp.274-280
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• 2016

In this study, it was to develop a chemical method that can recycle the cutting oil which accounts for about 25% of the cost of the process among containing materials of silicon waste sludge generated in the process for producing a solar cell wafer. The 7 types of reagents have been used, including acetone, HCl, NaOH, KOH, $Na_2CO_3$, HF, $CH_2Cl_2$, etc. for this experiment. And It was carried out at a speed of 3000 rpm for 60 minutes centrifugation after performing a reaction with a waste sludge at various concentrations. As a result, the best reagents and conditions for separating the solid such as a silicon powder and a metal powder and liquid cutting oil were identified as 0.3 N NaOH. It is found to be pH 6.05 in a post-processing recycled cutting oil with 0.3 N NaOH after reaction of waste sludge and 0.1 N HCl which is effective to remove metal powder in order to adjust the pH to suit the properties of the weak acid is a commercially available cutting oil and it showed excellent turbidity than when applied to sludge with 0.3 N NaOH alone. The results of FT-IR analysis which can compare the properties of the commercially available cutting oil shows it has a possibility of recycling oil. The cutting oil recovery rate obtained through the experiment was found to be 86.9%.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.13-25
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• 2009

Purpose: The DNA repair protein, $O^6$-methylguanine-DNA methyltransferase (MGMT), removes alkyl adducts from the $O^6$ position of guanine. Epigenetic inactivation of MGMT has been found in human neoplasia and considered one of the implicated factors in chemoresistance. Materials and Methods: Sixty-two patiensts with soft tissue sarcomas (STS) were analyzed for the status of MGMT protein expression by immunohistochemistry and the promoter hypermethylation of the MGMT gene using methylation-specific PCR. Result: The loss of MGMT expression was found in 20 cases (32.3%) of total 62 STS. MGMT promoter hypermethylation rate was 25.0% (11/44 cases). The loss of MGMT expression showed significant association with high AJCC stage, high FNCLCC grade, and aggressive behavior. However,when the group who received chemotherapy was analyzed (n=27), loss of MGMT expression was correlated with worse survival in multivariate analysis (p=0.024). MGMT promoter hypermethylation is associated with high FNCLCC grade. MGMT promoter hypermethylation status had a strong correlation with loss of MGMT expression (p=0.000). Conclusion: Our results suggest that MGMT promoter hypermethylation and loss of MGMT expression had a tendency to be associated with poor prognosis and that loss of MGMT protein expression is frequently occurs via MGMT promoter hypermethylation.

• Membrane Journal
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• v.11 no.4
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• pp.190-203
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• 2001

In this study the discharged wastewater from a paper plant was filtrated by 4 kinds of tubular carbon ceramic ultrafiltration membranes with periodic water-back-flushing. We could investigate effects of watch-back-flushing period, transmembrane pressure (TMP) and flow rate, and find optimal operating conditions. The back-f1ushing time (BT) was fixed at 3 sec, and fi1tration times (FT) werc changed in 15~60 scc, TMP in 1.00~2.50$kg_{f}$/$cm^2$, and the flow rates in 0.27~1.75 L/min. The optimal conditions were discussed in 7he viewpoints of dimensionless permeate flux (J/J$_{0}$), total permeate volume ($V^T$) and resistance of membrane fouling ($R^f$). Optima1 back-flushing period was BT/FT=0.20, suggesting that the frequent back-flushing should decrease membrane fouling. Optimal TMP in the viewpoint of $V^T$ was 1.00~1.55$kg_{f}$/$cm^2$, suggesting that rising TMP should increase membrane fouling and decrease permeate flux. But, rising f1ow rate should decrease membrane fouling and increase permeate flux. Then, average rejection rates of pollutants filtratedby carbon ceramic membranes were 88~98 % for turbidity, 48~72% fort $COD_{cr}$ and 37~76% for TDS.

• Journal of Life Science
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• v.26 no.7
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• pp.805-811
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• 2016

The present study was performed to evaluate the anti-oxidant and anti-proliferating activity of the water extract mixture of Cordyceps militaris (CM) and Allium tuberosum (AT). The water extract mixture rate of CM and AT was optimized by means of a sensory evaluation test. The optimized mixture rate were decided at 70% of CM, 30% of AT, and 10% of apple concentrate as an additive. The values of total acidity, pH, sugar contents, and turbidity of the water extract mixture were 0.1%, 4.28, 9.10 °Brix, and 1.48 respectively. The water extract mixture had effective DPPH radical scavenging activity, reducing power effect, and ABTS radical activity. DPPH radical activities of the water extract and the water extract mixture were 43.2% and 51.7% respectively; their reducing power (OD₇₀₀) was 1.14 and 1.43 respectively; and ABTS^.+ radical activities were 47.1% and 62.2% respectively. Also, the water extract mixture showed a higher anti-proliferating effect than the AT extract on human prostate cancer cells. These results provided experimental evidence that the water extract mixture of CM and AT is a better source of anti-oxidant and anti-cancer ingredients than a single extract of CM. In conclusion, the water extract mixture of CM and AT will be beneficial in development of a functional drink.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.328-328
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• 2016

우리나라는 생활용수의 대부분을 지표수에 의존하고 있는 실정이다. 그러나 지표수는 가뭄과 같은 기상변화, 수질사고 등으로 물 공급의 안정성에 문제가 되기도 한다. 향후 기후변화는 가뭄의 빈도와 강도를 증대시킬 것으로 파악되므로 수질 및 수량의 문제를 더욱 악화시킬 것으로 예상된다. 이러한 문제점을 해결하기 위해 지표수를 대수층 내에 인공적으로 함양한 뒤 대수층의 자연정화 기능에 의해 여과된 양질의 청정원수를 생산하는 기술을 본 연구에서 현장에 실증 적용하는 시설을 구축하였다. 이러한 기술은 기존의 지하 대수층을 이용하는 강변여과 등이 갖는 장점을 취하고 단점을 보완하였으며 친환경적이며 지속가능한 용수공급뿐만 아니라 청정 원수 확보를 통해 정수처리비용을 절감, 장기간의 가뭄이나 지표수 수질사고 시에 비상용수 공급 등 기존 취수원들과 달리 많은 장점을 갖고 있는 대규모 청정지하저수지 시험시설이다. 청정 지하저수지 기술이 주로 적용되는 지역은 해안지역 또는 하구 델타지역을 대상으로 한다. 해안 또는 델타지역은 해수침투로 인하여 염지하수가 부존되어 있기 때문에 지하수자원 활용에 매우 제한적이다. 따라서 지표수(담수)를 전처리하여 대수층에 인공적으로 함양을 하여 염지하수 대수층 안에 담지하수(담수체)를 형성할 수 있다. 이는 염수와 담수의 밀도차에 의해 희석되지 않는 특성을 이용한 기술이다. 청정 지하저수지 시험시설은 크게 지표수 취수시설, 전처리시설, 주입정, 양수정, 운영시스템으로 나눌 수 있다. 주입정 및 양수정은 원형의 형태로 지하저수지 조성범위 중심부에 9개의 주입정과 외각에 8개의 양수정을 설치하였다. 시험시설의 운영 과정은 하천수를 취수하여 전처리시설에서 탁도를 제거한 후, 피압대수층 염지하수에 동력으로 주입을 한다. 이때 기존에 부존되어 있던 염지하수를 밀어내고 담수체 지하수 형성을 유도한다. 일정기간 주입을 통해 목표 담수체를 만들어 내면 양수정에서 담수를 취수하되, 대수층의 모래자갈층을 일정거리 이동하여 취수하는 방식이다. 즉, 하천수를 대수층에 함양하고, 일정거리를 이동하여 취수하는 ASTR 방식의 대체수자원 확보 기술이다. 시험시설은 통합운영센터를 통해 원격감시 및 각종 제어/계측을 실시하며, 모니터링된 자료는 운영시스템에서 관리한다. 본 연구시설에서는 대수층 주입, 관정폐색, 미생물/지화학 수질반응, 지하수모니터링, 지반변형 등이 주요 핵심 연구를 진행하고 있도록 시설을 구성하였다. 본 시험시설은 2015년 8월 착공하여 2016년 4월에 완공 예정이며, 2016년 3월부터 주입을 시작하여 6개월간 피압대수층에 주입을 실시하고 이후부터 주입과 양수를 병행할 계획이다.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.72-81
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• 2021

Gravity-driven membrane (GDM) filtration system based on the nanofiber membrane was investigated. This system can be operated with little energy demand due to a gravitational pressure-driven filtration and biological fouling control strategy. Moreover, the optimal module configuration based on the high permeance of nanofiber membrane can provide a significantly high water productivity. In order to evaluate its applicability potential, the pilot-scale (3000-5000 L/day) systems with nanofiber membranes were operated in developing countries (Kiribati and Tuvalu). Our results showed that the 14-92 L/(m²×h) of the permeate flux was determined indicating a stabilized water productivity. In addition, the permeate water indicated a high removal rate (more than 99.99%) of turbidity and bacteria. Consequently, the system can provide a stabilized water production with safe permeate water quality during long-term operation. These findings exemplify an effective approach to decentralized drinking water treatment for developing countries.

• Food Science and Preservation
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• v.30 no.5
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• pp.896-904
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• 2023

The texturization characteristics of textured vegetable protein (TVP) were investigated based on the extent of soybean decoating during the pretreatment of defatted soybean flour used for TVP. The raw materials for TVP consisted of 50% defatted soybean flour, 30% gluten, and 20% corn starch. The weight ratios of soybean seed coat to soybean flour were 9%, 6%, 3%, and zero. Extrusion was performed using an extruder equipped with a cooling die, maintaining a barrel temperature of 190℃ and screw speed of 250 rpm, Water was injected at a rate of 9 rpm using a metering pump. Regarding the textures of the extruded TVPs produced from defatted soybean flour, an increase in the soybean seed coat content led to a decrease in the apparent fibrous structural layer and an increase in hardness. However, there were no significant changes in elasticity and cohesion. Moreover, as the soybean seed coat content increased, the pH of TVPs decreased. A higher soybean seed coat content also tended to lower the moisture content, increasing water absorption, solids elution, and turbidity. These results suggest that an increased seed coat content reduces the proportion of protein, and the fibers present in the seed coats prevent texturization.

• Applied Biological Chemistry
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• v.46 no.3
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• pp.201-206
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• 2003

An apple wine was prepared by fermentation at $25^{\circ}C$ for 2 weeks using Saccha개myces cerevisiae KCCM 12224, followed by aging at $15^{\circ}C$ for 14 weeks, and its physicochemical and microbiological changes were investigated. The viable bacterial cell numbers, increased from $1.4{\times}10^3\;CFU/ml$ at the beginning of fermentation, to $2.8{\times}10^6\;CFU/ml$ after 2 weeks, but decreased to $1.0{\times}10^5\;CFU/ml$ after aging. The viable yeast cell numbers changed from $4.3{\times}10^4\;CFU/ml$ to $1.2{\times}10^7\;CFU/ml$ during the fermentation, and decreased to $1.2{\times}10^4\;CFU/ml$ after aging. Sugar content changed from $20.0^{\circ}Brix$ to $8.5{\circ}Brix$, and reducing sugar content was changed from 9.66% to 6.44%. Alcohol content and acidity increased to 7.0% and from 0.19% to 0.24%, respectively. No changes in acidity, pH, and sugar content were observed during the aging, but reducing sugar and solid contents decreased. When apple wine was fultered through $0.45\;{\mu}m$ nitrocellulose membrane followed by various ultrafiltration membranes with different molecular weight cut-off values, the initial flux $(121.2\;liter/m^2/h)$ and the average flux of Biomax 100k membrane were the highest among the membranes used. These membrane filtration treatments resulted in complete removal of microorganisms as well as decrease in turbidity and solid content without changes in other chemical properties. No changes in the physicochemical properties of the apple wine and no microorganisms were detected during the storage at $156{\circ}C$ for 6 weeks.

• Food Science and Preservation
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• v.12 no.4
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• pp.379-386
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• 2005

Free amino acids and polysaccharide content of submerged mycelial culture of Fomitopsis pinicola using $2\%$ citrus peel water extracts(CP), $2\%$ green tea water extracts(GT) and yeast-malt broth(YM) were investigated. Cultivations were conducted at $30^{\circ}C$ and 150 rpm for 10 days. Yields of the mycelium as fresh weight basis in GT-, CP- and YM-broth were $42.3\%,\;34.2\%\;and\;9.89\%$, and their turbidity(OD at 660 nm) of the broth without mycelium were 0.14, 0.16 and 0.22, respectively. Total free amino acid content in the mycelium were 928.19 $mg\%$ in YM, 1060.53 $mg\%$ in CP, 764.83 $mg\%$ in GT, and the major free amino acid was lysine in YM, glutamic acid in CP and GT. Total free exo-amino acid contents were 659.75 $mg\%$ in YM, 954.55 $mg\%$ in CP, 838.69 $mg\%$ in GT, and the major in the all broths was glutamic acid Total amino acid derivatives content of the mycelium were in order of CP>GT>YM, and the major was cystathionine in YM, hydroxy proline in CP and GT. The major among exo-amino derivatives was hydroxy proline in the all broth. Exo-AIS content was in order of CP>GT>YM. Acid soluble polysaccharide content of the mycelium was GT($0.69\%$)>YM($0.39\%$)>CP($0.18\%$). The exo-polysaccharide content was in order of GT($0.87\%$)>CP($0.69\%$)>YM($0.09\%$). Alkali soluble polysaccharide content of the mycelium was in order of CP($5.21\%$)>GT($5.18\%$)>YM($4.56\%$), and exo-polysaccharide was in order of GT($6.79\%$)>YM($3.57\%$)>CP($3.01\%$). The alkali soluble polysaccharide eluted from mycelium cultivated in CP broth was supposed to polysaccharide(about 500,000 daltons) composed of hexose and uronic acid bounded with protein(below 10,000 daltons).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.225-237
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• 1990

Various chemical constituents were measured from April to August 1988 at the down-ward 20 stations of Keum River, which is located in the Midwest of Korea, to understand the characteristics of water quality with respect to spatio-temporal variations of each constituent. The 24-hrs continuous measurements with 2-hrs interval were made simultaneously at station 2 near the estuary weir and station 9(Ganggyeong) of 35 km upstream from the weir in April. By the results observed for one day in April at station 2, salinity has a range of $7.88\~22.14\%_{\circ}$ and its temporal variability is identical to the pattern of tidal cycle in the neigh-bouring Kunsan Harbor. However, turbidity shows relatively high values only at an interval of 4~5 hours after the lowest salinity time, though hourly fluctuation of pH is very small. Silicate and dissolved inorganic nitrogen have inversively linear correlationships with salinity, implying the concentration of the two nutrients strongly regulated by estuarine mixing of sea and river waters. In contrast, phosphate sustains roughly a constant level over a wide salinity range and distinctly lower values than those corresponding to nitrate in the oceans. Such distributions of phosphate have been observed in some estuaries, and interpreted as driven by removal of dissolved phosphate into bottom sediments and the bufforing of phosphate by particulate matter. COD values at station 2 are relatively high in day-time(particularly afternoon) and in high-salinity periods. At station 9, saltwater intrusion was never found but water level changed to the extent of 2.5 m for one day. Although each parameter at this station exhibits very slight variations in their abundance for 24 hours compared with station 2, the contents of COD, silicate and ammonia are significantly higher than at station 2. Concentration of suspended matter is relatively high in the brackish water region up to $\~20$ km above the river mouth, probably due to strong tidal stirring of the bottom de-posits. Also, relatively high pH, COD and $O_2$ saturation at the upward stations of $40\~50$ km from the weir are presumably attributable to active photosynthesis of plants in the region. In general, COD and nutrients except phosphate are higher values at the upper stations than in the estuary zone, and show the highest abundances in July nearly at all stations. Finally, in the estuarine region tidal mixing of sea-river waters seems to be an important factor controlling the distributions of turbidity, COD, silicate and nitrate as well as salinity. However, water quality in the upward fresh-water zone is remarkably variable according to months or seasons.