• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.362-362
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• 2006

Chromic acid anodizing of aluminium is an effective process for producing a substrate which provides excellent surface properties to assembly. However, new chromium-free finishing metal treatments are being developed to reach new environmental goals. Present study deals with chromium free experimental conditions for both deoxidizing and anodizing treatments. Results clearly demonstrate the potentiality for environmentally friendly treatments to get suitable metal-adhesive performance. In particular, the role of both metal surface porosity and chemical composition has been highlighted thus allowing to propose alternative to classical treatments for aeronautic applications.

• Geomechanics and Engineering
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• 제17권5호
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• pp.465-473
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• 2019

Biocementation due to the microbially induced calcium carbonate precipitation (MICP) process is a potential technique that can be used for soil improvement. However, the effect of biocementation may be affected by many factors, including nutrient concentration, bacterial strains, injection strategy, temperature, pH, and soil type. This study investigates mainly the effect of chemical concentration on the formation of calcium carbonate (e.g., quantity, size, and crystalline structure) and unconfined compressive strength (UCS) using different treatment time and chemical concentration in the biotreatment. Two chemical concentrations (0.5 and 1.0 M) and three different treatment times (2, 4, and 8 cycles) were studied. The effect of chemical concentrations on the treatment was also examined by making the total amount of chemicals injected to be the same, but using different times of treatment and chemical concentrations (8 cycles for 0.50 M and 4 cycles for 1.00 M). The UCS and CCC were measured and scanning electron microscopy (SEM) analysis was carried out. The SEM images revealed that the sizes of calcium carbonate crystals increased with an increase in chemical concentrations. The UCS values resulting from the treatments using low concentration were slightly greater than those from the treatments using high concentration, given the CCC to be more or less the same. This trend can be attributed to the size of the precipitated crystals, in which the cementation efficiency increases as the crystal size decreases, for a given CCC. Furthermore, in the high concentration treatment, two mineral types of calcium carbonate were precipitated, namely, calcite and amorphous calcium carbonate (ACC). As the crystal shape and morphology of ACC differ from those of calcite, the bonding provided by ACC can be weaker than that provided by calcite. As a result, the conditions of calcium carbonate were affected by test key factors and eventually, contributed to the UCS values.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.171-171
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• 2012

We have studied the effects of plasma treatments on CdS buffer layers in CIGS thin film solar cells. The CdS layers were deposited on CIGS films by chemical bath deposition (CBD) method. The RF plasma treatments of the CdS thin films were performed with Ar, $O_2 and $N_2 gases, respectively. After plasma treatments, the solar cells with Al:ZnO/i-ZnO/CdS/CIGS structures were fabricated. The surface properties of the CdS/CIGS thin films after plasma treatments were investigated with SEM, EDX and AFM measurements. The electrical properties of manufactured solar cell were discussed with the results of current-voltage measurements. The plasma treatments have a strong influence on the open circuit voltage (VOC) and the fill factor of the solar cells. Finally, a correlation between the surface properties of CdS layer and the efficiencies of the CIGS thin film solar cells is discussed.

• 한국양식학회지
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• 제15권1호
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• pp.49-60
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• 2002

Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

• 한국식품영양학회지
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• 제26권3호
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• pp.573-577
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• 2013

국내산 복숭아의 저장성 증진을 위하여 저선량(0~3.0 $kJ/m^2$)의 UV-C를 조사하고, 저장 중 주요 성분의 변화를 측정하였다. Polyphenol 화합물 함량은 UV 처리시 대조군에 비하여 약간 높은 함량을 보이는 것으로 나타났다. 특히 0.25 $kJ/m^2$ 처리군은 가장 많은 함량을 나타내었다. 저장 과정 중의 polyphenol 화합물의 함량은 대조군 및 UV 처리군 모두 서서히 감소하는 경향이었다. Flavonoid 함량은 대조군 및 UV 처리군 모두 저장하는 동안 특정한 경향을 나타내지는 않는 것으로 나타났다. 복숭아 내 유리당은 UV 처리군 및 대조군 모두 fructose, glucose, maltose 및 sucrose가 검출되었고, 이중 sucrose의 함량이 가장 많았으며, 저장 중 당 함량은 증가하였으며, UV 처리군 및 대조군 모두 유의적인 차이를 보이지 않았다. 유리아미노산은 대조군은 115.38 mg%였으며, UV-C 처리군의 경우, 총 유리아미노산의 함량은 95.92~120.94 mg%로 함량의 차이가 약간 있긴 하지만 유의적인 차이를 보이지 않아, 저선량의 UV-C 처리는 가능할 것으로 판단되었다.

• 한국식품위생안전성학회지
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• 제34권1호
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• pp.106-114
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• 2019

본 연구는 황색포도상구균 박테리오파지를 물리화학적 방법을 통해서 제어하기 위해 황색포도상구균을 대상으로 하는 SAP 84 와 SAP 89를 신규 분리하였다. 그리고, 황색포도상구균 박테리오파지에 대해 물리적 방법으로 $55^{\circ}C$ 및 $60^{\circ}C$ 열처리와 pH 4, pH 7, pH 10 처리하였다. 그 결과 SAP 84는 $60^{\circ}C$에서 급격히 감소하였고 SAP 89는 $60^{\circ}C$에서 25 분 만에 모두 활성을 잃었다. SAP 84는 pH 4 ~ 10에서 매우 안정적이었고 SAP 89는 pH 10 이상에서 비교적 불안정해지는 것을 보였다. 화학적 방법으로는 에탄올과 차아염소산나트륨 및 FAS 처리를 하였다. SAP 84가 50%, 70% 에탄올에서 급격히 감소하였다. 살균력이 좋은 100 ppm의 차아염소산 나트륨에서도 SAP 84와 SAP 89는 상당히 안정적인 상태를 유지하고 있다. Virucidal agent로 사용되는 FAS를 10% 농도로 처리하였을 때 SAP 84와 SAP 89 모두 처리 직후부터 제거되는 것을 확인할 수 있었다. 따라서 본 연구를 통해 SAP 84와 SAP 89 모두 화학적 처리 방법인 FAS 처리를 통해서 제어 가능함을 보여주었다. 이외에도 SAP 84는 물리적 방법인 열처리의 저감화 효과가 좋았으며 SAP 89는 화학적 방법인 에탄올 처리의 저감화 효과가 비교적 좋았다. 이렇듯 물리화학적 처리방법으로 황색포도상구균 박테리오파지를 제어 가능할 것으로 사료된다.

• 한국토양비료학회지
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• 제32권2호
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• pp.155-163
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• 1999

상수원 보호지역내 하성충적토의 사력질 벼 재배 논에서 표준시비 농가관행시비, 우분, 우분퇴비, 볏짚퇴비+화학비료감비, 볏짚환원+표준시비 그리고 무비구의 7처리를 하여 벼 재배 과정동안 시비관리방법에 따른 수량과 양분수지 특성을 조사하여 환경친화적 영농방법 설정을 시도하였다. 시비방법에 따른 정조수량은 추천시비구(100)와 우분구(100)에서 가장 우수하였으며, 화학비료 감비구(98) 볏짚환원구(98), 우분퇴비(94), 농가관행구(94) 순으로 감소하는 경향을 보였으나 처리간 통계적 유의성은 없었다. 질소수지는 농가관행구에서 $+39kg\;ha^{-1}$였으며. 유기물 처리구는 $+44{\sim}76kg\;ha^{-1}$로서 동일 포장조건에서 유기물 처리량이 증가할수록 양분수지의 +값이 커, 질소의 지하용탈량이 감소함을 알 수 있었다. 무기태 질소의 지하용탈량은 화학비료만 시용한 추천시비구($58kg\;ha^{-1}$)와 농가관행구($63kg\;ha^{-1}$)에서 가장 높았으며, 퇴비+화학비료 감비처리나 우분이나 우분퇴비로서 화학비료를 대체한 처리는($23{\sim}27kg\;ha^{-1}$) 화학비료 전용구(R. CF)의 절반 이하 수준($25kg\;ha^{-1}$)까지 줄일 수 있었다. 벼 재배기간중 인산의 지하용탈은 거의 없었다. 우분퇴비구(CMC)의 인산의 수지는 $+30kg\;ha^{-1}$으로 장기 연용에 따라 토양내 인산 축적이 가능성이 있을것으로 예측되며, 다른 처리의 인산 수지는 거의 0에 가까워 벼농사에서의 인산의 시비균형은 비교적 잘 이루어졌다. 칼리의 양분수지는 모든 처리에서 음(-)의 값을 보여 토양내 칼리가 용출되어 작물에 의해 흡수, 이용되고 있음을 알 수 있었다. 결과적으로 기존의 화학비료 위주의 추천시비 방식과 양평군 지역에서 주로 이용되고 있는 관행적 시비방법을 우분과 같은 유기질 비료로 적절히 대체 시용하거나, 볏짚퇴비의 환원 등을 통해 화학비료 사용량을 줄임으로써 벼의 수량을 높이면서 오염물질의 지하 유출을 크게 줄일 수 있었다.

• 한국토양비료학회지
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• 제51권1호
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• pp.71-78
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• 2018

This study was conducted to investigate the application effect of liquid fertilizer using pig cadavers on potato and corn cultivations in upland field. Field experiments were designed with control (Cn), liquid fertilizer (LF), inorganic fertilizer (IF), and LF + IF treatments. Crop yields in potato and corn cultivations were higher in the order of $LF+I{\geq_-}IF{\geq_-}LF$ > Cn treatments. The potato and corn yields in LF + IF treatment were 237% and 29% greater than those in Cn treatment, respectively. Following crops harvest, soil status was improved, showing greater soil chemical properties in the LF treated areas compared to those in the Cn treatment. In addition, total $CO_2$ fluxes in LF + IF treatment during potato and corn cultivations were significantly increased compared with Cn and IF treatments. Therefore, these results suggest that LF application was effective on crop cultivation and improvement of soil fertility.

• Environmental Analysis Health and Toxicology
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• 제24권3호
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• pp.231-240
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• 2009

We explored collective behaviors of indicator species to elucidate the effect of the chemical stress. After the treatments of an insecticide, diazinon, at low concentrations (1.0 and 10.0 ${\mu}g/L$), spatial dispersion patterns of Daphnia magna were checked in a test chamber. The I-index was used to characterize the movement data before (0~1 h) and after (1~2 h) the treatments in laboratory conditions. The slopes of the frequency distribution of I-index in semi-log scale decreased significantly, and the test populations appeared to be more dispersed with a lower degree of aggregation after the treatments. The index was feasible in indicating decrease in the ability of the specimens to keep desirable distances with neighbor individuals under chemical stress and showed a possibility of monitoring presence of toxic chemicals in environment through group behavior measurement.

• 한국자기공명학회논문지
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• 제14권1호
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• pp.28-37
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• 2010

Metabolites of urine samples from 6 colorectal cancer patients were analyzed by two-dimensional NMR spectroscopy, where the samples were collected before and after the surgical treatments per patient. NMR data were analyzed with the help of the metabolome database and the statistics software. Urine samples before and after the treatments showed significantly different metabolic profiles from each other. We were able to compare 10 different metabolites. Most of the assigned metabolites of every patient showed a tendency of increase after the surgery except for a few cases. The amount of changes in individual metabolites varied significantly from patient to patient, but the combination of such changes could be used to distinguish the condition before the surgery from after, which could be done by PCA analysis. The analysis via $^{1}H-^{13}C$ HSQC spectra proved to be applicable in assessing and classifying global metabolic profiles of the urines from colorectal cancer patients.