• 한국표면공학회지
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• 제57권1호
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• pp.31-37
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• 2024

The surge in demand for lithium is primarily fueled by the expanding electric vehicle market, the necessity for renewable energy storage, and governmental initiatives aimed at achieving carbon neutrality. This study proposes a straightforward method for lithium extraction utilizing cellulose nanofiber (CNF) via a vacuum filtration process. This approach yields a porous CNF film, showcasing its potential utility as a lithium extractor and indicator. Given its abundance and eco-friendly characteristics, cellulose nanofiber (CNF) emerges as a material offering both economic and environmental advantages over traditional lithium extraction techniques. Hence, this research not only contributes to lithium recovery but also presents a sustainable solution to meet the growing demand for lithium in energy storage technologies.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.42-47
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• 2024

The electrochemical extraction of uranium in ternary low melting LiCl-KCl-CsCl eutectic on inert and reactive electrodes via different electrochemical techniques was investigated. It was established that the electrochemical reduction process of U(III) ions on the inert W electrode was irreversible and proceeded in one stage. On reactive liquid Ga and liquid Cd electrodes the reduction of uranium ions took place with the considerable depolarization with the formation of UGa₂, UGa₃ and UCd₁₁ intermetallic compounds. Thermodynamic characteristics of uranium compounds and alloys were calculated. The conditions for the extraction of uranium from the electrolyte in the form of alloys on both liquid reactive electrodes via potentiostatic electrolysis were found.

• 보존과학회지
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• 제25권4호
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• pp.451-464
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• 2009

토기 및 도자기 유물의 표면 오염물을 제거하기 위해서는 경우에 따라 화학적 세척과정이 필요하며, 그 과정은 신중하게 이루어져야 한다. 본 연구에서는 화학적 세척제가 토기 및 도자기에 미치는 영향을 평가하기 위해 침적실험을 수행하여 주성분원소의 용출특성에 대해 정량적인 데이터를 제공하고자 하였다. 연질토기는 재질이 약하고 흡수율이 커서 짧은 침적 시간에도 큰 용출특성을 가졌고 강한 산성에 의해서 표면 박락과 색의 변화가 발생했다. 그러나 이러한 색의 변화는 물리적인 특성에는 영향을 미치지 않았다. 경질토기에서는 용출량이 미비하고 강한 산성에 의한 색차변화와 물리적인 변화가 없는 것으로 확인되어, 세척제에 대해 비교적 안정한 것으로 사료된다. 도자기(청자, 백자, 분청사기)에서는 용출량이 미비하여 시료의 안정성에는 영향을 미치지 않는 것으로 판단된다. 하지만 도자기 유물에서는 빙렬이 용출특성에 관여하는 것으로 확인되어 분청사기 같은 빙렬이 발달된 유물에 적용할 시에는 주의가 필요하다.

• 한국생활과학회지
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• 제21권5호
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• pp.989-1004
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• 2012

The purpose of this study was to investigate the characteristics of the pigment and the dyeability of juniperus chinensis needles, berry, bark and heartwood extracts using distilled water, methanol, normal butanol and ethyl acetate as a solvent. Ultraviolet-visible absorption spectrum bands of the extracts were measured at around 280nm to 320nm in all the solvent extracts. The maximum absorption wavelength was able to determine tannin. All the solvent extracts except for distilled water extracts were able to confirm the presence of chlorophyll. Infrared absorption spectra (FT-IR) of all parts of the extracts showed broad absorption bands of OH due to phenolic-OH, benzene CH peak of phenol chemical structure, ether-based stretching vibration peak and the peak of flavonoid compounds that appeared in all the solvent extracts. The yield of juniper needles and heartwood in distilled water and methanol extraction were effective. Extraction of berry yields in distilled water was also effective. The yield of ethanol extraction from the bark showed better efficiency. As a result of using distilled water for the dye solution, the color of the fabrics dyed with all extracts of the needles and Y series berries generally showed light Y progression with a strong red tinge. By using a mixture of 20% ethanol and 80% distilled water for the dye solution, the color of the fabrics dyed with needles and berry extracts showed Y series dominantly. The color of the fabrics dyed with Bark and heartwood extracts were dominantly R series.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1647-1654
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• 2008

The characteristics of arsenic(As) contamination were investigated on soils of 3 abandoned metal mine sites in Gangwon-do, Korea. Total forty nine soils were sampled to conduct standard methods(extraction by 1HCl), sequential extraction and column leaching test. Concentration of As extracted by 1N HCl was ordered as follows: A mine > B mine > C mine, and the concentration of arsenic in the soils of A mine was significantly greater than that at any other cases and all samples of A mine were exceeded the national regulation of $6mg \;kg^{-1}$. In the results of sequential extraction, the potential contamination risk for groundwater and plants was ordered as follows: C mine > B mine > A mine because the C mine showed the relatively greater mobility and bioavailability of fraction than any other mines. And, in colume test, concentration of As was ordered as follows: C mine > B mine > A mine, and it was expected that these results were connected with fraction characteristics of the mine sites. Therefore adequate leaching investigations should be used to simulate the effect of natural leaching conditions, and to predict both the potential mobility of metals to groundwater and their bioavailability to plants under natural conditions.

• 대한치과교정학회지
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• 제48권6호
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• pp.405-411
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• 2018

Objective: This study was performed to investigate the rate of tooth movement and histological characteristics of extraction sockets those were subjected to corticotomy. Methods: A split-mouth randomized controlled trial experiment was designed. Thirty-two adult, male Wistar rats were divided into 2 groups: healing extraction socket (H) and recent extraction socket (R); these groups were randomly classified into 4 subgroups (0/7/21/60 days). The first maxillary molar was extracted on 1 side and 2 months were allowed for complete bone healing; then, the corresponding molar was extracted on the other side and surgical intervention was performed at the mid-alveolar point of the first maxillary molar. Ten grams of continuous force was applied. The outcomes measured were rate of tooth movement, percentage of periodontal space and histological evaluation. The rate of tooth movement was calculated as the measured distance divided by the duration of molar movement. Histomorphometric evaluations were performed on the second and third maxillary molars. The Wilcoxon signed rank test was used to compare differences between the two groups. Results: There were no significant differences in the rates of tooth movement between H and R groups at any of the 4 time points. The histological appearance and percentage of periodontal space between the R and H groups also demonstrated no significant differences. Conclusions: The rates of orthodontic tooth movement into recent and healed socket sites did not differ between the groups. Histological analysis of tooth movement revealed regional acceleration during every time period.

• 한국식품영양학회지
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• 제26권4호
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• pp.706-712
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• 2013

음청류에 이용할 수 있는 오미자 추출액을 얻기 위해 증류수, 수돗물과 Ca, Mg 등의 미네랄이 풍부한 청송약수를 이용하여 오미자 추출액을 제조하고 이화화적 특성을 측정하였다. 오미자 추출조건으로는 25배의 용매비로써 실온에서 6, 9, 12, 15시간, $65^{\circ}C$에서 2, 3, 6, 9시간 동안 추출하였다. 추출용액의 명도(L, Lightness), 적색도(a, redness), 황색도(b, yellowness), 가용성 고형분(solid content), 산도(acidity), pH, DPPH 라디칼을 소거능을 이용한 전자 공여능(Electron Donating Ability, EDA)으로부터 전반적으로 양호한 추출조건을 구한 결과는 다음과 같다. 실온에서는 물의 종류에 상관없이 12시간 추출하는 것이 적당하였으며, $65^{\circ}C$ 가온 상태에서는 6시간 추출함이 적합함을 알 수 있었다. 가온 상태에서 약수의 경우 증류수, 수돗물에 비해 빠른 추출이 가능하였으며, 추출 시간이 증가함에 따라 산도는 낮아지나, 고형분의 양과 DPPH 라디칼을 소거능은 증가하였다. 전반적으로 고려할 때에 오미자 추출을 위한 가장 적합한 물로는 미네랄이 풍부한 약수이며, 다음으로 수돗물 그리고 증류수 순서임을 알 수 있다.

• 한국수산과학회지
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• 제50권6호
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• pp.650-655
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• 2017

Extraction methods for cultured sea mussels Mytilus edulis and the quality characteristics of resulting extracts were investigated. The crude protein, carbohydrate and volatile basic nitrogen content of raw sea mussels was 15.2%, 1.9%, and 11.2 mg/100 g, respectively. Extracts were prepared using three different methods: hot-water extract (WE), scrap enzymatic hydrolysate extraction (SE), and complex extraction (CE). The respective extracts contained 5.5%, 8.6%, and 6.6% crude protein; 281.7, 366.0, and 343.0 mg/100 g amino nitrogen,: and 2.0%, 1.1% and 1.8% salinity. Their extraction yields were 689, 323, and 1,012 mL/kg. The CE method was superior to the traditional WE method in terms of extraction yield, amino-nitrogen content, and organoleptic qualities, but not odor. Active taste components were evaluated and the total free amino acid content of the WE and CE methods was 5,667.0 and 7,006.3 mg/100 g, respectively. The concentrations of major components (for WE and CE methods, respectively) were as follows: glutamic acid (1,244.0 and 955.4 mg/100 g), taurine (987.9 and 746.8 mg/100 g), glycine (721.2 and 847.0 mg/100 g), alanine (341.9 and 423.8 mg/100 g), arginine (265.5 and 376.5 mg/100 g), lysine (199.8 and 270.4 mg/100 g), and proline (253.9 and 220.3 mg/100 g). In conclusion, these results demonstrate that there is potential for using the CE method to expand the commercial utilization of sea mussels as a flavoring substance resource.

• 한국식품영양학회지
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• 제33권2호
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• pp.131-141
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• 2020

This purpose of this study was to investigate the quality characteristics of jellies added with lemon myrtle extract. Lemon myrtle leaves were extracted for 0, 3, 5, 7, 9 minutes, respectively, in 90℃ water and used for jelly preparation. The moisture content of control showed the lowest value and the content increased significantly as the extraction time of lemon myrtle increased. The pH of L0 was significantly high and increased significantly with the increase of extraction duration time. The lightness value was the lowest in the L3. The redness showed the lowest value in the L9. The yellowness showed the lowest value in the L0. In texture properties the hardness of L9 showed the highest value and the lemon myrtle extraction duration increased significantly. The cohesiveness was highest in the L0 and lowest in the L5. Gumminess and chewiness increased significantly with increasing extraction duration. Total polyphenol content was the highest in the L5 and the jellies with lemon myrtle extracts were significantly higher than the L0. DPPH radical scavenging activities increased significantly with increasing extraction duration. The ABTS radical scavenging activity of the L0 was the lowest. In the sensory evaluation overall preference, color, sweetness, texture, and lemon myrtle flavor did not show any significant differences among the samples.

• 공업화학
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• 제7권6호
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• pp.1053-1060
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• 1996

Sodium amide에 의한 methyl propyl ketone과 ethyl formate의 반응으로 킬레이트 추출제의 하나인 $\beta$-ketohexanal(이하 KHA)를 합성하고, KHA-클로로포름에 의한 구리의 추출평형 실험을 통하여 추출특성을 고찰하였다. 흡광도를 측정하여 추출제 KHA의 상간 분배계수와 해리상수, KHA와 구리간 킬레이트의 안정도 상수와 분배계수 및 총괄 추출 평형상수등을 구하고, 추출기구를 구명하였다 합성한 추출제에 의한 구리의 추출율은 pH 5 이상에서 거의 100%이었고, Cu-Zn-Cd 혼합 금속으로부터 구리의 선택적 추출이 가능하였다. KHA-클로로포름에 의한 구리의 추출 화학종은 $CuR_2$였으며 추출 평형 식은 $Cu^{2+}+2{\overline{HR}}{\rightarrow}{\overline{CuR{_2}}}+2H^+$로 표시되었다.