• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제25회 춘계학술대회
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• pp.33-40
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• 1997

This study was undertaken to investigate tribology characteristics of the alumina ceramics($Al_2O_3$) for the vauiation of ambient condition such as air and distilled water. The results obtained were as follows. As the sliding speed increases, the friction coefficient in the air decreased due to the reduction of sheafing stress caused by the heat accumulation of contact interface. And the friction coefficient in the distilled water decreased due to an activation of the tribochemical reaction. As the contact load increases, the friction coefficient is small in the air due to temperature rise of the contact interface. However, at the low speed side in the distilled water, the friction coefficient holds a large value due to decrease of the tribochemical reaction. The friction surface of ceramics can be protected in the air by the influence of the oxides tansfered from STB2 and also in the distilled water by the influence of the corrosive productive hydroxides.

• Journal of Applied Biological Chemistry
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• 제51권4호
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• pp.155-159
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• 2008

A local isolate of Aspergillus niger was cultivated under optimal growth conditions on wheat bran in solid state fermentation. Filter paperase from fermented bran was separately extracted with different solvents to test the recovery of the enzyme. Among solvents tested, distilled water served as the best leachate, thus the conditions were further optimized with distilled water. After two washes of fermented bran with distilled water for 1.5 h each under stationary conditions at 1 g wheat bran: 5 mL distilled water, the maximum recovery of 13.5 $Ug^{-1}$ of wheat bran was obtained.

• Composite Materials and Engineering
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• 제3권3호
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• pp.167-178
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• 2021

In the present paper, the destructive behavior of distilled water, salty water, sulfuric acid, and heat on glass/vinyl ester composites was investigated by experimental methods. Hetron 922 vinyl ester resin and two types of mat and woven glass fibers as the reinforcements were used to fabricate composite test samples. All samples were immersed in distilled water, salty water, and sulfuric acid with three different concentrations. The tests were performed at 20℃ and 70℃ for the exposure duration of 1, 2, 4, and 8 weeks. Bending tests were performed after aging for all composite samples to check the degradation of the bending modulus and strength. The results show that the effect of distilled water, in comparison with salty water, on the degradation of composite samples was significant. On the other hand, almost non-sensitivity of concentrations of salty water on the weight gain of specimens has been observed. In addition, it was also observed that the degradation of samples at 70℃ temperature is much more than that of at 20℃. Also, it was observed that the flexural modulus of virgin specimens exposed to salty water (2% concentration) has been recovered just after two weeks of immersion. Furthermore, in some cases, composite samples under the sulfuric acid solution have lost almost 80% of their mechanical properties.

• 펄프종이기술
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• 제38권4호
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• pp.53-60
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• 2006

Paper materials for long term conservation suffer slowly mechanical and chemical deterioration, the extent of which may depend upon their conservation environment. Those deterioration includes discoloring, low moisture content, acidification, and brittleness. To slow deterioration, washing treatment, deacidification, and polymer reinforcement on paper materials are usually used. One easy and simple method of fixing low moisture content and acidification was an washing method, and we used both distilled and alkali water in washing method in this study. Alkali water is electrolyzed cathode water of high pH, and has no alkali metal ions in it. Experiment showed that washing treatment with both distilled and alkali water gave improvement in raising moisture content, pH, and mechanical strength of paper materials even after severe accelerated aging test. Advantageous effect of alkali water over distilled water on preventing deterioation was also shown clearly.

• 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.

• 지질공학
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• 제34권1호
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• pp.25-38
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• 2024

본 연구에서는 해수와 산성증류수가 암석 풍화에 미치는 영향을 파악하기 위하여 실내인공풍화가속실험을 수행하였다. 70℃의 해수와 산성증류수(pH 3)를 이용하여 총 45회의 동결-융해 실험을 통하여 5종의 유천층군 화산암에 대하여 화학적·물리적 풍화를 모사하였다. 실내인공풍화가속실험 15회와 45회에 각각 물리적 물성과 일축압축강도를 측정하여 풍화 진행에 따른 물성 변화를 추적한 결과, 물리적 물성의 열화는 대부분은 초기 15회 실험에서 발현되었으며, 산성증류수가 해수보다 물리적 물성 변화에 더 많은 영향을 미치는 것으로 파악되었다. 실내인공풍화가속실험에 따른 암종별 일축압축강도의 차이를 통계적으로 평가하기 위하여 분산분석법을 사용하였다. 45회 실험 이후의 대조군에 대한 실험군 시료의 일축압축강도의 감소율은 암종과 물리적 물성 변화 추이와 상관없이 유사하게 나타났지만, 물리적 물성 변화와는 달리, 산성증류수보다 해수가 일축압축강도 변화에 더 많은 영향을 미치는 것으로 파악되었다.

• 한국식품저장유통학회지
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• 제24권6호
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• pp.871-878
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• 2017

제주산 녹차, 로즈마리, 레몬 잎, 조릿대 잎을 물과 에탄올을 이용해 다양한 조건에서 추출물을 제조하여 각 추출물에 대한 항산화 활성을 측정하였다. 그 결과, 녹차와 로즈마리 추출물이 레몬과 조릿대 잎 추출물과 비교하여 상대적으로 높은 항산화 활성을 보였다. 항산화 활성이 상대적으로 우수한 녹차와 로즈마리 추출물들을 두유에 첨가한 뒤, 혼합물의 항산화 활성을 측정하였다. 녹차 증류수 가압 가열 추출물과 상온 정치 추출물 10% 첨가한 두유에서 상대적으로 가장 높은 활성을 보였으며, 녹차 증류수 가압 가열 추출물과 상온 정치 추출물의 DPPH 라디칼 소거능은 각각 $85.1{\pm}2.3%$, $84.4{\pm}2.0%$을, ABTS 라디칼 소거능은 각각 $73.4{\pm}2.8%$, $81.3{\pm}4.8%$로 확인되었다. 한편, 로즈마리 증류수 가압 가열 추출물 10% 첨가한 두유에서 무첨가 두유에 비해 더 높은 DPPH 라디칼 소거능이 확인되었으며, ABTS 라디칼 소거능은 무첨가 두유와 유사했다. 따라서 녹차 증류수 가압 가열추출물과 상온 정치 추출물, 그리고 로즈마리 증류수 가압 가열 추출물을 두유에 첨가 시 항산화 활성이 향상된 고부가가치 두유제품 개발 제발이 가능할 것으로 기대된다.

• 한국염색가공학회지
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• 제15권3호
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• pp.140-145
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• 2003

The purpose of this study is searching the Elm-Bark dyes' dyeability and antibacterial activities according to the dyeing time, pH, a mordant and the method of mordancy. We used two kinds of Elm-Bark dyes which's extracted by the Electrolytic reduction water and Distilled water. Silk fabric and Cotton/nylon union fabric was used for this study. The results are as follow. K/S value is increased according to the dyeing time and the suitable pH level is pH 3. Dyeability is good with Iron(II) sulfate$(FeSO_4\cdot{7H}_2O)$ on the pre-mordancy and Potassium dichromate$(K_2Cr_2O_7)$ on the post-mordancy. The Elm-Bark dyes by the Electrolytic reduction water has good colorfastness more than by the Distilled water. Antibacterial activities is excellent and the ratio is over than 99.5%.

• 한국환경과학회지
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• 제20권10호
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• pp.1265-1272
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• 2011

In this study, the extraction characteristics of soluble solid from Rumex crispus(Curled dock) was studied from the investigation of the effects of experimental conditions on extraction rate; extraction ratio, composition of extractants, extraction time and pH of extractant, etc. The proximate composition of Rumex crispus was 2.58% crude lipid, 5.59% crude protein, 7.39% crude ash, 6.13% moisture and 78.31% carbohydrate, respectively. Turbidity of extract by distilled water was higher and increased with extraction time and extraction temperature, where as the turbidity didn't increase by ethanol and methanol in 20 folds of extraction ratio. Turbidity was inversely proportional to the extraction ratio for the three extractants at 25$^{\circ}C$ and 1 hour extraction. But turbidity of extract was highest by composition of 50% methanol-water extractant than any other compositions of extractants. Eighteen and fifteen free aminoacids were detected in extracts with distilled water, methanol and ethanol extractant, respectively, and it's contents were order of glutamic acid>proline>aminobutyric acid>alanine. The extraction rate of soluble solid from Rumex crispus was order of distilled water>methanol>ethanol within experimental extraction ratio. In extraction with distilled water, the contents of soluble solid was inversely proportional to the pH of extractant.

• 한국해양공학회지
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• 제12권3호통권29호
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• pp.31-41
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• 1998

Single fiber fragmentation technique was used to evaluate the change of interfacial properties by degradation of fiber tensile strength in the fiber reinforced composites. The influences of fiber tensile strength on the interfacial properties have been evaluated by the fragmentation specimens(weak fiber samples) of glass fiber/epoxy resin that was made using the pre-degraded glass fiber in distilled water at $80^{circ}C$ for specified periods. The effects of the immersion time on the interfacial properties in the distilled water at $80^{circ}C$ also have been evaluated by the fragmentation specimens(original fiber samples) of glass fiber/epoxy resin that was made using the received glass fiber. As the result, the tensile strength of glass fiber was decreased with the increasing of the treatment time in the distilled water at $80^{circ}C$ and the interfacial shear strength was independent of the change of the glass fiber strength in the single fiber fragmentation test. But in the durability test using the single fiber fragmentation specimen, interfacial shear strength decreased with the increasing of the immersion time in distilled water ar $80^{circ}C$. And it turned out that the evaluating of interfacial shear strength using original fiber tensile strength was valuable in the durability test for the water environment by the single fiber fragmentation technique.