• 제목/요약/키워드: Aqueous

검색결과 7,435건 처리시간 0.031초

Hexamine 수용액의 안정성에 관한 연구 (Studies on the Stability of Hexamine Aqueous Solution)

  • 우종학
    • 약학회지
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    • 제7권2_3호
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    • pp.51-54
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    • 1963
  • In this experiment, it is found that the decomposition reaction of hexamine aqueous solution by heat is the pseudo first order reaction and the calculated decomposition velocity constants of Hexamine aqueous solution are 1.17 * $10^{-5}min.^{-1}(60{\deg}$ C), 1.99 * $10^{-5}min.^{-1}(70{\deg}$ C), 2.35 * $10^{-5}min.^{-1}(80{\deg}$ C), 6.63 * $10^{-5}min.^{-1}(100{\deg}$ C). In the result, the activation energy of decomposition reaction of hexamine aqueous solution is 12 $Cal.mole^{-1}$.

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수계 테이프 케스팅 법에 의한 봉상 γ-LiAlO2 입자 강화 MCFC 매트릭스 제조 공정의 최적화 (Optimization of Rod-shaped γ-LiAlO2 Particle Reinforced MCFC Matrices by Aqueous Tape Casting)

  • 최현종;신미영;현상훈;임희천
    • 한국세라믹학회지
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    • 제46권3호
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    • pp.282-287
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    • 2009
  • Rod-shaped particle reinforced $LiAlO_2$ matrices for MCFC were fabricated by an aqueous tape-casting technique. The hydrolysis reaction and agglomeration of $\gamma-LiAlO_2$ particles in aqueous slurries were inhibited by additions of $LiOH{\cdot}H_2O$ and glycerin to the aqueous $\gamma-LiAlO_2$ slurry. The tape-casting, performed using the aqueous slurry containing protein albumin, was fast and led to an effective drying at casting temperature range of $60{\sim}65^{\circ}C$. The strength of the particle reinforced matrix was improved about 4 times compared to that of matrix without reinforcement. Pore size distribution ($0.1{\sim}0.4{\mu}m$) and porosity ($50{\sim}60%$) of the reinforced matrices were determined to be appropriate for the MCFC matrix. The aqueous tape casting process is not only environmental-friendly but also efficient for fabricating MCFC matrices compared to non-aqueous tape casting.

환경친화적 수계/준수계 세정 기술 (Enviromentally Friendly Aqueous/Semi-aqueous Cleaning Technology)

  • 배재흠;김정식
    • 청정기술
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    • 제3권2호
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    • pp.36-46
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    • 1997
  • CFC 및 유기염소계 용제는 정밀기기 및 전자산업에서 세정제로 여러 가지 우수한 성질이 있어 오랫동안 사용하여 왔지만 오존층을 파괴하는 물질로 규명되어 대체 세정제로의 사용이 불가피한 실정이다. 대체 세정제로서는 여러 종류가 있지만 수계/준수계 세정제가 환경친화적이라 장기적으로 가장 바람직하여 이의 사용과 개발이 선진국을 중심으로 점차 증가일로에 있다. 그러나 이에 대한 국내의 이용 및 연구는 빈약하다. 본 연구에서는 수계세정제중 알칼리성, 중성, 산성, 비휑금형과 이의 주요구성성분, 그리고 준수계세정제중 테르펜계 및 glycol ether계를 분석하였다. 또한 수계/준수계세정제를 사용함으로써 이용가능한 여러 세정장치를 비교평가하였고 산업체에서 세정시스템의 선정시 중요 고려사항을 분석제안하였다.

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24년생 장생도라지 약침액(藥鍼液)의 폐렴 증상 개선효과에 대한 임상례 (Clinical report on the improvement of the symptoms of pneumonia by the aqueous extract of Platycodon grandiflorum)

  • 김숙경;최성권;임희정;문익렬;박형선;오수진
    • 대한약침학회지
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    • 제4권3호
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    • pp.59-67
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    • 2001
  • Objective: The purpose of this report is to prove the clinical effect of Platycodon grandiflorum aqueous extract on pneumoniae patients. Methods: We used the aqueous extract of Platycodon grandiflorum to treat two pneumoniae patients. It was injected into five acupuncture points, which was Chondol(天突:CV22) 1 point, Pyesu(肺兪 : BL13) 2 point, and Kworumsu(厥陰兪: BL14) 2 point. Results & conclusions: We have used the aqueous extract of 24-year-old JK for treating the patients suffering from lung diseases, and have experienced the actual effects. Of the treated, two pneumonia-involved patients showed apparent improvement in simple chest X-ray and clinical symptoms. The patients were treated with JK (Jang-saeng platycodon) aqueous extract 25 and 22 times individually. The results were as follows. 1. The symptoms including coughing, phlegm, and fever were improved in two cases. 2. The lung infiltration in simple chest X-ray decreased and the WBC count was kept within normal range in two cases. 3. Side effect such as itching was not found in the process of JK aqueous extract treatment. 4. The criteria for pneumonia are fever, coughing with purulent phlegm, pleural chest pain, the evidence of new infiltration in simple chest X-ray, sign of lung sclerosis in auscultation, increase of WBC count, etc. But they may not be the proper objective diagnostic standards. So we had trouble in statistic process and numerical interpretation. Putting these results together, the JK aqueous extract is considered to be effective in treating patients for pneumonia, and the continuous research and accumulation of data is needed.

Effect of Aqueous Chlorine Dioxide Treatment on the Microbial Growth and Quality of Chicken Legs during Storage

  • Hong, Yun-Hee;Ku, Gyeong-Ju;Kim, Min-Ki;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • 제13권1호
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    • pp.45-50
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    • 2008
  • The effect of aqueous chlorine dioxide ($ClO_2$) treatment on microbial growth and quality of chicken leg during storage was examined. Chicken leg samples were treated with 0, 50, and 100 ppm of $ClO_2$ solution and stored at $4^{\circ}C$. Aqueous $ClO_2$ treatment significantly decreased the populations of total aerobic bacteria, yeast and mold, and coliforms in chicken leg. One hundred ppm $ClO_2$ treatment reduced the initial populations of total aerobic bacteria, yeast and mold, and coliforms by 0.93, 1.15, and 0.94 log CFU/g, respectively. The pH and volatile basic nitrogen values in the chicken leg decreased with increasing aqueous $ClO_2$ concentration, while concentrations thiobarbituric acid reactive substances (TBARS) increased during storage regardless of aqueous $ClO_2$ concentration. Sensory evaluation results revealed that the quality of the chicken leg treated with aqueous $ClO_2$ during storage was better than that of the control. These results indicate that aqueous $ClO_2$ treatment can be useful for improving the microbial safety of chicken leg during storage.

다양한 아민 흡수제를 이용한 천연가스 중에 포함되어 있는 산성가스 제거 성능 비교 (Comparison of Removal Capabilities among Several Aqueous Amine Absorbents for Sweeting Acid Gases Contained in Natural Gas)

  • 조두희;김동선;조정호
    • 플랜트 저널
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    • 제10권1호
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    • pp.34-39
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    • 2014
  • 본 연구에서는 상용성 공정모사기인 BR&E사의 PROMAX를 사용하여 amine류 흡수제인 30 wt%의 MEA수용액, 30 wt%의 DEA수용액 그리고 50 wt%의 MDEA수용액과 50 wt%의 MDEA에 첨가제로써 3 wt%의 piperazine을 첨가한 공정을 이용하여 천연가스 중에 포함되어 있는 산성가스인 $CO_2$$H_2S$ 성분의 제거 성능에 대한 비교 작업을 수행하였다. 공정모사 결과로 MEA는 상대적으로 많은 $CO_2$를 제거 할 수 있는 반면에 DEA, MDEA, MDEA와 첨가제인 piperazine은 $H_2S$를 많이 제거한다는 것을 알 수 있었고, MEA 30 wt%수용액의 경우는 lean amine의 circulation rate가 가장 적은 것으로 나타냈다. 재비기의 heat duty는 MDEA 50 wt%에 첨가제인 piperazine 3 wt% 수용액이 가장 적음을 알 수 있었다. 또한 MDEA 그리고 MDEA와 첨가제인 piperazine을 비교해 보면 첨가제로 인하여 solvent circulation rate가 감소된 것을 알 수 있었다.

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Inactivation of Vibrio parahaemolyticus by Aqueous Ozone

  • Feng, Lifang;Zhang, Kuo;Gao, Mengsha;Shi, Chunwei;Ge, Caiyun;Qu, Daofeng;Zhu, Junli;Shi, Yugang;Han, Jianzhong
    • Journal of Microbiology and Biotechnology
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    • 제28권8호
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    • pp.1233-1246
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    • 2018
  • Vibrio parahaemolyticus contamination causes serious foodborne illness and has become a global health problem. As a disinfectant, aqueous ozone can effectively kill a number of bacteria, viruses, parasites, and other microorganisms. In this study, three factors, namely, the aqueous ozone concentration, the exposure time, and the bacterial density, were analyzed by response surface methodology, and the aqueous ozone concentration was the most influential factor in the sterilization ratio. Under low aqueous ozone concentrations (less than 0.125 mg/l), the bacterial cell membranes remained intact, and the ozone was detoxified by intracellular antioxidant enzymes (e.g., superoxide dismutase and catalase). Under high aqueous ozone concentrations (more than 1 mg/l), cell membranes were damaged by the degree of peripheral electronegativity at the cell surface and the concentration of lactate dehydrogenase released into the extracellular space, and the ultrastructures of the cells were confirmed by transmission electron microscopy. Aqueous ozone penetrated the cells through leaking membranes, inactivated the enzymes, inhibited almost all the genes, and degraded the genetic materials of gDNA and total RNA, which eventually led to cell death.

비수계 바나듐 레독스 흐름 전지를 위한 상용 멤브레인의 특성분석 (Characterization of Commercial Membranes for Non-aqueous Vanadium Redox Flow Battery)

  • 성기원;신성희;문승현
    • Korean Chemical Engineering Research
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    • 제51권5호
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    • pp.615-621
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    • 2013
  • 본 연구에서는 수계 레독스 흐름전지에서 사용하는 멤브레인 특성분석방법을 개선하여 비수계 레독스 흐름 전지를 위한 멤브레인 특성분석방법을 확립하였다. 비수계 레독스 흐름 전지에 적합한 멤브레인 특성을 확인하기 위해 상용 멤브레인의 이온교환능력, 이동수, 이온 전도도, 활물질 투과도, 전지효율 실험 등 특성분석들을 수행하였다. 상용 음이온 교환 멤브레인의 특성분석 실험을 통해 충 방전 효율 및 에너지효율과 이온 선택성의 상관관계를 조사하였다. Neosepta AHA 음이온 교환 멤브레인은 이동수 측정에서 0.81의 값으로 비수계 전해질에서 비교적 낮은 이온 선택성을 보였지만, 충방전 전지효율 평가에서는 92%의 충 방전효율과 86%의 에너지효율을 각각 나타내었다. 또한 이온의 선택성이 없는 다공성 멤브레인은 높은 전류밀도의 비수계 레독스 흐름 전지에 적절함을 알 수 있었다.

코로나 방전에 의한 NOx, $So_2$동시제거에서 첨가제의 영향 (Effect of an Additives on Simultaneous Removal of NOx, $So_2$by Corona Discharge)

  • 박재윤;고용술;이재동;손성도;박상현
    • 한국전기전자재료학회논문지
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    • 제13권5호
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    • pp.451-457
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    • 2000
  • Experimental investigations on the effect of two kinds of additives ; aqueous NaOH solution and ammonia(NH$_3$) for removal of NOx and SO$_2$ simultaneously by corona discharge were carried out. The simulated combustion flue gas was[NO(0.02[%])-SO$_2$(0.08[%])-$CO_2$-Air-$N_2$] Volume percentage of aqueous NaOH solution used was 20[%] and $N_2$flow rate was 2.5[$\ell$/min] for bubbling aqueous NaOH solution Ammonia gas(14.81[%]) balanced by argon was diluted by air. NH$_3$ molecular ratios(MR) based on [NH$_3$] and [NO+SO$_2$] were 1, 1.5 and 2.5 The vapour of aqueous NaOH solution and NH$_3$was introduced to the main simulated combustion flue gas duct through injection systems which were located at downstream of corona discharge reactor. NOx(NO+NO$_2$) removal rate by injecting the vapour of aqueous NaOH solution was much better than that by injecting NH$_3$however SO$_2$removal rate by injecting NH$_3$was much better than that by injecting the vapour of aqueous NaOH SO$_2$removal rate slightly increased with increasing applied voltage. When the vapour of aqueous NaOH solution and NH$_3$were simultaneously injection NOx and SO$_2$ removal rate were significantly increased.

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Anti-obesity effects of two herbal extracts in C57BL/6N mice fed high-fat diet

  • Hyuck Kim;Jihwan Lee;Seyeon Chang;Dongcheol Song;Jaewoo An;Sehyun Park;Kyeongho Jeon;Jungseok Choi;Jinho Cho
    • 농업과학연구
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    • 제51권1호
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    • pp.87-95
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    • 2024
  • The objective of this study was to investigate the anti-obesity effects of adding Momordica charantia (MC) and Chrysanthemum zawadskii var. latilobum (CZ) extracts to drinking water on obesity-induced mice. A total of 84 eight-week-old C57BL/6N male mice with an initial body weight (BW) of 28.11 ± 1.39 g were used in this study. All treatments were fed a high-fat diet for d 28. Mice were randomly divided into seven drinking treatments (six replicate each treatment) based on the initial BW. Treatments are as follows: control (CON), normal tap water, MC 1, CON with 1% MC aqueous extract, MC 2, CON with 2% MC aqueous extract, CZ 1, CON with 1% CZ aqueous extract, CZ 2, CON with CZ aqueous extract (2%), MCZ 1, CON with 1% MC aqueous extract and 1% CZ aqueous extract, MCZ 2, CON with 2% MC aqueous extract and 2% CZ aqueous extract. During the entire period, the CZ 1, MCZ 1, and MCZ 2 significantly decreased (p < 0.05) gain to feed than CON. The CON significantly higher (p < 0.05) water intake than other treatments on d 0 to 14. The MCZ 1 significantly decreased (p < 0.05) relative (ratio of absolute organ weight to BW) organ weights, including retroperitoneal white adipose tissue (RWAT) weight and inguinal white adipose tissue (IWAT) weight, compared to CON. In conclusion, our study suggests that there was no significant difference in the anti-obesity effects between MC and CZ, and MCZ 1 has synergistic effects by regulating adipose tissue.