• Membrane and Water Treatment
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• 제11권5호
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• pp.323-331
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• 2020

With the increasing demand on reverse osmosis (RO) membranes for water purification worldwide, the number of disposed membrane elements is expected to increase accordingly. Thus, recycling and reuse of end-of-life RO membranes should be a global environmental action. In this work, we aim to reuse the spent RO membrane for nanofiltration (NF) and ultrafiltration (UF) process by subjecting the spent membrane to solvent and oxidizing solution treatment, respectively. Our results showed that solvent-treated RO membrane could perform as good as commercial NF membrane by achieving similar separation efficiencies, but with reduced water permeability due to membrane surface fouling. By degrading the polyamide layer of RO membrane, the transformed membrane could achieve high water permeability (85.6 L/㎡.h.bar) and excellent rejection against macromolecules (at least 87.4%), suggesting its reuse potential as UF membrane. More importantly, our findings showed that in-situ transformation on the spent RO membrane using solvent and oxidizing solution could be safely conducted as the properties of the entire spiral wound element did not show significant changes upon prolonged exposure of these two solutions. Our findings are important to open up new possibilities for the discarded RO membranes for reuse in NF and UF process, prolonging the lifespan of spent membranes and promoting the sustainability of the membrane process.

• 대한본초학회지
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• 제23권3호
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• pp.27-32
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• 2008

Objectives : In this paper, we describe that $^1H-NMR$ spectroscopy may be superior to the conventional HPLC for the quantitative analysis of hesperidin from Citrus unshiu. Methods : $^1H-NMR$ spectra (400 MHz) were recorded in $DMSO-d_6$ using a Varian UNITY Inova AS 400 FT NMR spectrometer. One hundred milligram of powdered Citrus unshiu was weighed out and mixed with 1 ml of $DMSO-d_6$ with sonication for 30 min (room temperature). The extracts were filtrated through a 0.45 ${\mu}m$ PVDF filter and 0.5 ml of filtrated extract used for quantitative $^1H-NMR$ measurement (added 1 mg of dimethyl terephthalate as internal standard). The quantity of hesperidin was calculated by the ratio of the intensity of the compound to the known amount of internal standard. For HPLC analysis, the half gram of plant material was extracted with 60 ml of MeOH for 2 hours. The extracts were made 100 ml volume and analyzed by a Waters HPLC system using a YMC ODS column. The total flow rate was 1.0 ml/min with a sample volume 10 ${\mu}l$ and UV detection at 280nm. Results : The contents of hesperidin in Citrus unshiu was determined $5.33{\pm}0.06$% in the quantitative $^1H-NMR$ method and $5.15{\pm}0.12%$ in HPLC method. Using the quantitative $^1H-NMR$ the contents of hesperidin can be determined in much shorter time than the conventional HPLC measurements. Conclusions : From those results, the advantages of quantitative $^1H-NMR$ analysis are that can be analyzed to identify and quantify, and no reference compounds required for calibration curve. Besides, it allows rapid and simple quantification for hesperidin with an analysis time for only 10 min without any pre-purification steps.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1253-1258
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• 2012

Two phenolic allopyranosides and two phenolic amide allopyranosides, along with eight known phenolic compounds, including cimicifugic acids, shomaside B, fukiic acid, isoferulic acid, and piscidic acid, were isolated from the n-butanolic extract of rhizomes of Cimicifuga heracleifolia. On-line spectroscopic data for UV, NMR, and MS from a combination of LC-NMR and LC-MS techniques directly and rapidly provided sufficient structural information to identify and confirm all the structures of major phenolic compounds in the extract, in addition to their HPLC profiles. This combined analytic information was then used as a dereplication tool for structure-guided screening in order to isolate unknown phenolic compounds in the extract. Successive fractionation and purification using semi-preparative HPLC acquired four unknown allopyranosides, and their structures were identified as cis-ferulic acid 4-O-${\beta}$-D-allopyranoside, trans-ferulic acid 4-O-${\beta}$-D-allopyranoside, trans-feruloyltyramine 4-O-${\beta}$-D-allopyranoside, and trans-feruloyl-(3-O-methyl)dopamine 4-O-${\beta}$-D-allopyranoside, based on a subsequent spectroscopic interpretation.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 1999년도 제2회 학술발표회
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• pp.1-20
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• 1999

일본에서는 오래 전부터 물리탐사 기술을 토목${\cdot}$건설분야에 널리 활용해왔다. 특히 굴절법 탄성파탐사는 지반조사법으로 이미 확립되었다고 해도 과언이 아닐 정도로 산악 터널, 댐, 산사태 등의 조사에 주로 사용되었다. 그러나 사회의 가치관의 변화와 환경문제가 대두되면서 사용되는 물리탐사기술 및 그 적용범위가 많이 다양해졌다. 그리고 컴퓨터를 비롯한 디지털기술의 발달에 힘입어 측정기술과 해석기술이 발전함에 따라 짧은 시간에 대량의 데이터를 측정할 수 있으며, 객관성과 신뢰성이 높은 해석결과를 얻을 수 있게 되었다. 또한 지반의 가시화기술로 탐사결과를 보다 알기 쉽게 영상화할 수 있게 되었다. 최근에는 지반개량 효과의 판정, 터널 막장의 전방탐사, 지하수의 거동, 오염 및 정화 과정의 모니터링 등에 관한 물리탐사기술이 눈부시게 발전하고 있으며, 자연재해 방지를 위한 지반조사에도 널리 사용되고 있다. 현재는 3차원의 물리탐사 기술이 완성단계에 이르러 이의 토목${\cdot}$건설분야에 대한 활용이 눈앞에 와 있다.

• Food Science and Biotechnology
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• 제16권1호
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• pp.90-98
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• 2007

The antioxidant activities of water ($H_2O$) and ethanol (EtOH) extracts from hamcho (Salicornia herbacea L.) juice and cake prepared by enzymatic treatments were evaluated by in vitro assays against DPPH, superoxide, and hydroxyl radicals. Among the $H_2O$ and EtOH extracts from five different carbohydrases treated, the EtOH extract from viscozyme-treated hamcho cake had higher yield and phenolic content, and exhibited the strongest radical scavenging activity against DPPH ($IC_{50}=186.91\;{\mu}g/mL$), superoxide ($IC_{50}=87.54\;{\mu}g/mL$), and hydroxyl radicals ($IC_{50}=367.07\;{\mu}g/mL$). Antioxidant assay-guided fractionation and purification of the EtOH extract led to isolation and identification of five phenolic compounds, procatechuic, ferulic and caffeic acids, quercetin, and isorhamnetin. Most of these phenolic compounds exhibited considerable DPPH, superoxide, and hydroxyl radical scavenging activities, and in particular, caffeic and ferulic acids had stronger superoxide and hydroxyl radical scavenging activities than the well-known antioxidant radical scavenger, (+)-catechin (p<0.05). Quercetin and isorhamnetin were the primary compounds responsible for the strong antioxidant activity in the EtOH extract of the viscozyme-treated hamcho cake. Meanwhile, these five phenolic compounds were detected in the EtOH extract of the viscozyme-treated hamcho cake at the following levels (dry base of hamcho); procatechuic acid (1.54 mg%), caffeic acid (6.87 mg%), ferulic acid (8.45 mg%), quercetin (12.63 mg%), and isorhamnetin (6.65 mg%). However, three of these phenolic compounds (procatechuic, caffeic acid, and ferulic acids) were detectable in the $H_2O$ extract of viscozyme-treated hamcho juice. These results suggest that the EtOH extract of viscozyme-treated hamcho cake may be a potential source of natural antioxidants.

• 한국수정란이식학회지
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• 제24권4호
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• pp.259-263
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• 2009

Salivary lipocalin (SAL1) is a member of the lipocalin protein family that has a property to associate with many lipophilic molecules and was identified as pheromone-binding protein in pigs. Our previous study has shown that SAL1 is expressed in the uterine endometrium in a cell type- and implantation stage-specific manner and secreted into the uterine lumen in pigs. However, function of SAL1 in the uterus during pregnancy in pigs is still not known. To understand physiological function of SAL1 in the uterine endometrium during pregnancy in pigs, it needs to elucidate the ligand(s) for SAL1. Thus, to identify the ligand for SAL1 in the porcine uterus, we collected uterine luminal fluid from pigs on day 12 of pregnancy by flushing with PBS. Proteins from the uterine luminal fluid were separated by ion exchange chromatography and gel filtration. Fractions containing SAL1 protein were pooled and concentrated. Immunoblot analysis confirmed successful purification of SAL1. Then, we extracted lipids from the purified SAL1 protein and analyzed the lipids by liquid chromatography-mass spectrometry, and predicted to be steroid hormones and prostaglandins as SAL1 ligands. Results in this study showed that SAL1 protein in the uterine secretions has a small lipophilic molecule as a natural ligand. Further characterization of ligand extracted from purified SAL1 will be useful for understanding physiological function of SAL1 during pregnancy and its application to increase the pregnancy rate in pigs.

• 디자인학연구
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• 제18권3호
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• pp.219-222
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• 2005

본 작품은 쾌적하고 청결한 주거환경을 유지하기 위해 사용되는 공기청정기 제품에 있어서 벽면을 이용한 기기 운용방식에 관한 디자인 개발 연구이다. 최근 들어 생활수준이 향상됨에 따라 건강에 대한 관심이 증대되고 인간의 건강과 직결되는 실내에서의 공기청정에 대한 관심이 높아지면서 공기청정기의 사용과 그 수요가 크게 증가하고 있으며 이에 따라 공기청정기 시장도 확대되며 다양한 디자인의 제품들이 등장하고 있다. 그러나 현재 시장에 나와 있는 대부분의 제품들은 스탠드 방식으로서, 설치를 위해서는 적지 않은 공간이 필요하며 구조상 공기의 흡 배기를 위해 설치장소의 선정에 많은 제약이 따른다. 따라서 본 연구는 이미 에어컨 제품에서 널리 사용되고 있는 벽걸이 방식의 디자인 컨셉을 도입하여 설치장소의 제약 최소화와 함께 벽면장식의 효과도 가져을 수 있는 방식의 디자인을 시도하였다. 이 과정에서 사용자 편의를 위해 필터의 교환과 청소를 용이하게 하였고 다양한 기능을 간단하게 조작할 수 있도록 하였으며, 실내 어느 장소에나 잘 어울릴 수 있도록 전체적으로 슬림하면서도 미려하고 자연스러운 곡선이 직사각과 조화를 이루도록 디자인하였다.

• 자원리싸이클링
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• 제14권5호
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• pp.54-61
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• 2005

국내 경제성장과 더불어 발전소 에너지원으로 이용되고 있는 석탄은 매년 증가하여 2006년에는 전체 에너지 구성의 30%인 16,000MW에 이를 것으로 예측되고 있다. 이러한 석탄은 다른 화석연료에 비해 매장량이 풍부하고 경제성은 높지만, 사용이 불편하고 석탄회, 아황산가스 등 많은 공해물질을 배출하고 있다. 따라서 본 연구에서는 마찰하전형정전선별법을 이용하여 석탄과 회분구성 광물의 선별기술을 확립, 청정석탄을 생산하고자 한다. 본 연구에서는 bench-scale의 마찰하전형정전선별 장치를 제작하였으며, 선별에 영향을 미치는 인자들을 선정하고 분리실험을 수행하여 최적조건을 확립하였다. 연구결과 최적조건에서 석탄 회수율과 회분 및 유황분 제거율이 각각 68.10%. 31.23% 그리고 28.33%인 정제석탄을 얻을 수 있었다.

• 한국물환경학회지
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• 제32권2호
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• pp.205-215
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• 2016

In order to improve water quality in the Paldang Lake, a riparian vegetation belt, treatment wetland, and artificial floating island were designed for introduction in the upland field, the estuary of tributaries, and the section of water facing mountainous land, respectively. We synthesized vegetation information collected from a reference river and found that herbaceous, shrubby, and tree vegetation zones tended to be dominated by Phragmites japonica, Phalaris arundinacea, etc.; Salix gracilistyla, S. integra, etc.; and S. koreensis, S. subfragilis, and Morus alba, respectively. In our plan, the herbaceous vegetation zone, which is established on floodplains with a high frequency of disturbance, will be left in its natural state. A shrubby vegetation zone will be created by imitating the species composition of the reference river in the ecotone between floodplain and embankment. A tree vegetation zone will be created by imitating species composition on the embankment slope. In the treatment wetland, we plan to create emerged and softwood plant zones by imitating the species composition of the Zizania latifolia community, the Typha orientalis community, the P. communis community, the S. integra community, and the S. koreensis community. The floating island will be created by restoring Z. latifolia and T. orientalis for water purification purposes.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1165-1170
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• 2008

The deposition of the amyloid $\beta}$ ($A{\beta}$)-peptide following proteolytic processing of amyloid precursor protein (APP) by $\beta$-secretase (BACE1) and $\gamma$-secretase is critical feature in the progress of Alzheimer's disease (AD). Consequently, BACE1, a key enzyme in the production of $A{\beta}$, is a prime target for therapeutic intervention in AD. In the course of searching for BACE1 inhibitors from natural sources, the ethyl acetate fraction of Petasites japonicus showed potent inhibitory activity. Two BACE1 inhibitors quercetin (QC) and kaempferol 3-O-(6"-acetyl)-$\beta$-glucopyranoside (KAG) were isolated from P. japonicus by activity-guided purification. QC, in particular, non-competitively attenuated BACE1 activity with $IC_{50}$ value of $2.1{\times}10^{-6}\;M$ and $K_i$ value of $3.7{\times}10^{-6}\;M$. Both compounds exhibited less inhibition of $\alpha$-secreatase (TACE) and other serine proteases including chymotrypsin, trypsin, and elastase, suggesting that they ere relatively specific and selective inhibitors to BACE1. Furthermore, both compounds significantly reduced the extracellular $A{\beta}$ secretion in $APP_{695}$-transfected B103 cells.