• 한국물환경학회지
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• 제20권3호
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• pp.281-289
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• 2004

Optimal analytical conditions have been established for mixing and reaction coil length, concentrations of ECR, CTAB, and acetate, reaction temperature and pH in the determination of aluminum by using flow injection analysis(FIA). Detection limit and repeatability for this system were $3{\mu}g/L$ and better than 1% of relative standard deviation, respectively. The interference from iron(III) was suppressed up to 6mg/L of iron(III) by $0.1{\mu}M$ ascorbic acid, and the interference from fluoride could be tolerated in absorption of Al/ECR/CTAB derivative by 10mM boric acid at pH 3.5 adjusted with nitric acid. This FIA system was applied to the determination of aluminum leached from cooking utensils by distilled and tap water containing fluoride ranged from 0.5 to 2mg/L by measurement of absorbance for Al/ECR/CTAB at 585nm. The leached aluminum content was increased with increasing concentration of fluoride. The aluminum contents leached from aluminum utensils by tap water were about 9 fold higher than those leached by distilled water, whereas aluminum contents leached by distilled water containing fluoride were about 2 fold higher compared to those leached by distilled water. That represented that other dissolved substances as well as fluoride in tap water contributed to liberation of aluminum from aluminum utensils. A comparison between FIA data and ICP-AES data by correlation and paired t test showed that the FIA system could be accepted as a good alternative method for the determination of aluminum in tap water.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1181-1181
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• 2001

Robinson with ${coworkers}^{1}$ have introduced two-state outer-neighbor bonding model to explain the anomalies of water. The studies on the properties of water as a function of temperature and pressure revealed that, unlike other ideas, all $H_2O$ molecules in liquid are tetrabonded. On the average they are forming two different bonding types. One type is the regular tetrahedral water-water bonding similar to that found in the ordinary ice Ih, whereas the other is a more dense nonregular tetrahedral bonding similar to that appearing in the ice II. The transformation between these two bonding forms is evidenced by FT-NIR experiment. The FT-NIR measurements were done for liquid water in the temperature range from $20^{\circ}C$ up to $80^{\circ}C$ in a wide extent of frequencies: 12 000 - 4000 $cm^{-1}$ /. Temperature dependent variations in the volume fraction of these two structures are directly related to the spectral changes. The absorbance variations are explored by means of the two-dimensional correlation spectroscopy (2DCOS), principal component analysis (PCA), curve fitting and second derivatives. The presence of the isosbestic points in a range of the combination and overtone transitions indicates that the experimental spectra are a superposition of two temperature independent components. One component of diminishing intensity with temperature increase, is assigned to a stronger hydrogen bonds occurred in the Ih type, whereas the second component showing an opposite behavior, one can attribute to a weaker H-bonds characteristic for the II type. The understanding of the hydrogen bonding network in the liquid water is very important in interpretation of the interaction between water and protein chain. The two-state model of water surrounding the protein surface could advance an understanding of the hydration process.

• 상하수도학회지
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• 제9권3호
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• pp.99-107
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• 1995

Various humic substances are widely distributed in natural water body, such as rivers and lakes and cause the yellowish or brownish color to water. The evidence that humic substances are precursors of THMs formation in chlorinated drinking water has been reported m the Jiteratures. For the reason of public health as well as aesthetics, needs for humic substances removal have been increased in the conventional water treatment processes. In this research, the characteristics of aluminium coagulation of humic acids and humic acids were investigated. The optimum pH and coagulants dosage to remove these materials simultaneously by coagulation were alto studied. The results are as followed; 1. UV-254 absorptiometry for measuring the concentration of aquatic humic acids showed good applicability and stable results. 2. The optimal pH range for humic acids removal by aluminium coagulation was 5 to 5.5, however, an increase in aluminium coagulant dosage could enhance the removal rate of humic acids in the wide pH range. 3. Coprecipitation of humic acids in the typical pH range of 6.5 to 8 in water treatment processes may require the sweep coagulation mechanism with the excess aluminium coagulant dosage. 4. Using PAC(poly aluminium chloride) or PASS(poly aluminium silica sulfate) as coagulants was able to expand the operating range for removing humic acids. 5. From the coagulation of humic substances(UV-254) and turbidity at pH range of 5.5 - 6.0 and alum dose of 86 ppm, the removal efficiency of turbidity from the reservoir water was above 90% and that of UV-254 was above 70%. 6. By using the reservoir water, the optimum condition of rapid mixing for simultaneous removal of turbidity and UV-254 absorbance was pH of 5.8 and LAS dose of 86 ppm, in this study.

• 한국식품과학회지
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• 제31권2호
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• pp.361-367
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• 1999

항산화작용 및 항균작용이 있다고 알려져 있는 녹차 물추출물을 이용하여 조미오징어의 품질을 개선하기 위하여 분무하여 수분함량을 조정한 후 $30^{\circ}C$에서 보관하면서 저장중 갈색도의 변화를 측정하였다. 갈색도의 측정으로는 물추출색소, 5% KOH-methanol 추출색소, 색차계 등의 방법을 사용하였다. 물추출색소 및 5% KOH-methanol 추출색소를 이용하여 측정하였을 경우 처리구간의 높은 상관관계를 나타내어 적절한 갈색도 측정방법으로 생각되었다. 녹차의 물추출물을 분무한 처리구의 경우 저장기간에 따라 TBA가의 변화속도가 대조구보다 다소 느리게 측정되었으며 총미생물수도 낮게 측정되어 조미오징어 제조시에도 항산화작용 및 항균작용이 존재함을 알 수 있었다. 녹차 물추출물을 분무하여 조미오징어를 제조할 경우 수분함량을 다소 높여 조직감 개선에 기여할 수 있을 것으로 생각되었으며 갈변도 억제하므로 품질개선에 유효함을 알 수 있었다.

• 지질공학
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• 제16권2호
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• pp.153-159
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• 2006

수질오염이 심각해지면서 수자원의 이용을 어렵게 하며 수자원의 관리를 위해 사용되는 시간적 기술적 경제적 부하도 증대시키고 있다. 그러므로 본 논문에서는 간단하고 신속하게 수질을 파악 할 수 있는 미규제 수질인자($E_{260}$과 입자수)를 도입하여 정수공정의 효율성을 평가하고자 하였다. 탁도저감을 목적으로 주입하는 알루미늄에 의해 용존성 알루미늄의 잔존량이 증가하는 경향이 있으므로 탁도 모니터링만으로는 안전한 수질을 기대하기가 어려움을 명확히 알 수 있었으며, 잔존알루미늄의 농도를 모니터링 하는 대신 간단 신속하게 분석할 수 있는 $E_{260}$인자를 이용할 수 있음을 밝혔다. 또한 탁도 뿐만 아니라 용존성 비소화합물의 모니터링에도 $E_{260}$은 효율적으로 사용되었다. 수처리공정의 효율을 개선하기 위해 수처리제의 교환을 고려할 때에도 탁도 자료만으로는 질적인 개선정도를 평가하기 어려웠으나, 수중의 입자를 계수함으로써 재선정도의 평가가 용이해져 적절한 수처리제의 선택을 가능하게 하므로 수질개선과 경제적 절약을 모두 달성하게 하였다. 따라서 효율적인 정수처리 뿐만 아니라 수자원의 관리 측면에서도 이들 인자는 매우 유용하게 사용될 수 있을 것으로 기대된다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.3115-3115
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• 2001

In this study, portable near infrared (NIR) system was newly integrated with a photodiode array detector, which has no moving parts and this system has been successfully applied for evaluation of human skin moisture. The good correlation between NIR absorbance and absolute water content of separated hairless mouse skin was, in vitro, showed depending on the water content (7.42-84.94%) using this portable NIR system. Partial least squares (PLS) regression was used for the calibration with the 1100-1650 nm wavelength range. For the practical use for the evaluation of human skin based on moisture, PLS model for human skin moisture was, in vivo, developed using the portable NIR system based on the relative water content values of stratum corneum from the conventional capacitance method. The PLS model showed a good correlation. This study indicated that the portable NIR system could be a powerful tool for human skin moisture, which may be much more stable to environmental conditions such as temperature and humidity, compared to conventional methods. Furthermore, in order to confirm the performance of newly integrated portable NIR system, scanning type conventional NIR spectrometer was used in the same experiments and the results were compared.

• Preventive Nutrition and Food Science
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• 제15권1호
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• pp.36-43
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• 2010

The purpose of this study was to investigate the phenolic acid, proanthocyanidin (PAs), and flavonol glycoside contents, as well as the antioxidant activities of pine needle extracts from six species of young pine trees. The extracts were prepared from Section Pinus (Diploxylon): P. densiflora, P. sylvestris, P. pinaster and P. pinea, and Section Strobus (Haploxylon): P. koraiensis and P. strobus. Phenolics were extracted from pine needles with 80% acetone to obtain the soluble free fraction, and insoluble residues were digested with 4 M NaOH to obtain bound ethyl acetate and bound water fractions. Phenolics were analyzed by HPLC, and the hydrophilic antioxidant activity was measured using oxygen radical absorbance capacity (ORAC). Total phenolic and flavonoid contents of the soluble free fraction were higher than those of the bound ethyl acetate and bound water fractions. The main phenolics were monomers and polymers of PAs in the soluble free fraction, and phenolic acids and flavonol glycosides in bound ethyl acetate fraction. Flavonol glycosides found in different species of pine needles were qualitatively similar within fractions, but composition varied among Pinus sections. High levels of kaempferol arabinoside and an unknown compound were present in all Strobus species. The soluble free fraction had the highest antioxidant activity, followed by bound ethyl acetate and bound water fractions.

• 한국염색가공학회지
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• 제11권2호
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• pp.27-37
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• 1999

Polypropylene(PP) films were treated with plasma glow discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PP film surfaces were subsequently used for the graft polymerization of acrylic acid and acrylamide in an aqueous solution by heating, respectively. Introduction of acrylic acid and acrylamide on the PP film could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. And introduction of functional group could be confirmed by weight analysis and ESCA. The water contact angle(90$^{\circ}$) of PP film was constant, irrespective of elapsed time, while plasma-treated and functional monomer-grafted PP films were slowly increased with elapsed time, showing the rearrangement of surface polar groups in air condition. The water contact angle$(90^\circ)$ of PP film was decreased by the plasma treatment$(56^\circ)$ and further decreased by the grafting of acrylic acid$(34^\circ)$ and acrylamide$(37^\circ)$, indicating increased hydrophilicity of the modified surfaces. The water contact angle of plasma-treated PP film increased a little as time elapsing. The half-life periods of surface voltage on acrylic acid-(31sec) and acrylamide-grafted PP(42sec) were significantly decreased when compared to those on PP(950sec) and plasma-treated PP film(241sec). In the experiments using acid, basic and disperse dyes, absorbance and $\Delta{E}$ values of functional monomer-grafted PP films were significantly increased than that of oxygen plasma-treated one.

• 한국세라믹학회지
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• 제48권6호
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• pp.630-635
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• 2011

Bismuth vanadate($BiVO_4$) with monoclinic phase as photocatalyst under visible light is synthesized by precipitation reaction in hot water. Properties such as crystal phase, particle morphology and visual light absorbance as well as the effects of thermal treatment for $BiVO_4$ powders are investigated. $BiVO_4$ powders with both single monoclinic phase and 0.2 ${\mu}m$ in particle size are synthesized when precipitate is stirred in water for 5 h at 95$^{\circ}C$. Well-developed monoclinic phase and light absorption property under 535 nm are observed as a result of thermal treatment for 1 h at 300$^{\circ}C$ after precipitation reaction in water for 5 h at 95$^{\circ}C$. Degradation of monoclinic crystal is found in firing above 350$^{\circ}C$, and particle growth is occurred in firing above 550$^{\circ}C$.

• 한국식품조리과학회지
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• 제29권5호
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• pp.573-580
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• 2013

We investigated the physiological activities of extracts from Lindera obtusiloba Blume leaf and twig (LLW: water extract from Lindera obtusiloba Blume leaf, LLE: 50% ethanol extract from Lindera obtusiloba Blume leaf, LTW: water extract from Lindera obtusiloba Blume twig, LTE: 50% ethanol extract from Lindera obtusiloba Blume twig). Total polyphenol and total flavonoid contents of LTE were 445.38 mg/g and 302.09 mg/g, respectively. The electron donating ability (95.38%) of LTE was higher than that of the LLE (93.76%), LTW (88.09%), and LLW (82.06%). The oxygen radical absorbance capacity of extracts were improved with 50% ethanol condition, rather than hot water. Superoxide radical scavenging activity and FRAP activity of the extracts were improved with an increase of treatment concentration. All the extracts($1,000{\mu}g/mL$) stimulated a production of nitric oxide (NO) in macrophage RAW264.7 cells. In particular, the NO stimulating activity of LTE was superior to that of LLE, LTW, and LLW. The antitumor activity of LTE ($500{\mu}g/mL$) in A549, HeLa and SNU719 was 55.63%, 83.87% and 68.11%, respectively. The UVB-induced MMP-1 production in HS68 cells was suppressed by the treatment of LTE (88.28%), LLE (83.96%), LTW (80.59%) and LLW (76.08%).