• Title/Summary/Keyword: Aqueous

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

  • 우종학
    • YAKHAK HOEJI
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    • v.7 no.2_3
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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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Optimization of Rod-shaped γ-LiAlO2 Particle Reinforced MCFC Matrices by Aqueous Tape Casting (수계 테이프 케스팅 법에 의한 봉상 γ-LiAlO2 입자 강화 MCFC 매트릭스 제조 공정의 최적화)

  • Choi, Hyun-Jong;Shin, Mi-Young;Hyun, Sang-Hoon;Lim, Hee-Chun
    • Journal of the Korean Ceramic Society
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    • v.46 no.3
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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.

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

  • Bae, Jae-Heum;Kim, Jung-Sik
    • Clean Technology
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    • v.3 no.2
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    • pp.36-46
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    • 1997
  • CFC and organic chlorine solvents has been used in the fine machinery and electronics industries for a long time since they have various excellent properties as cleaning agents. However, it is inevitable that alternative cleaning agents should be used since CFC and organic chlorine solvents were identified as ozone-depleting chemicals. There are various alternative cleaning agents. Among them, aqueous/semi-aqueous cleaning agents are environmentally friendly and promising in the long term. And their use and developement are on the increase in advanced countries, but few in our countries. In this paper, the charactistics and major components aqueous/semi-aqueous cleaning agents are analyzed and compared. And various cleaning equipments for aqueous/semi-aqueous cleaning agents such as immersion cleaner, ultronsonic cleaners, power spray cleaner, and vibration or rotational cleaners are compared and evaluated. Finally, important consideration points for selction of a cleaning system are analyzed and suggested in this paper.

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

  • Kim, Sook-Kyeng;Choi, Sung-Gwun;Lim, Hyi-Jeong;Moon, Ik-Ryoul;Park, Hyeong-Seon;Oh, Su-Jin
    • Journal of Pharmacopuncture
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    • v.4 no.3
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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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    • v.13 no.1
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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.

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

  • Cho, Du-hee;Kim, Dong-sun;Cho, Jung-ho
    • Plant Journal
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    • v.10 no.1
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    • pp.34-39
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    • 2014
  • Simulation works for comparing removal capabilities of acid gases contained in natural gas among several aqueous amine absorbents using commercial process simulator PROMAX(BR&E Co.) were carried out. Amine aqueous solution used in this study were 30 wt% MEA, 30 wt% DEA, 50 wt% MDEA, and 50 wt% MDEA with 3 wt% piperazine as additive. We obtained the simulated results that while MEA aqueous solution is relatively capable of more $CO_2$ gas, but DEA, MDEA, MDEA aqueous solutions with piperazine as additive are capable of more $H_2S$ gas. Also, we found that 30 wt% MDA aqueous solution is the smallest circulate rate of lean amine solution, and 50 wt% MDEA aqueous solution with 3 wt% piperazine as additive is the smallest heat duty in stripping unit. 50 wt% MDEA aqueous solution with 3 wt% piperazine as additive is found less amine circulation rate than 50 wt% MDEA due to the introduction of additive.

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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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    • v.28 no.8
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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.

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

  • Sung, Ki-Won;Shin, Sung-Hee;Moon, Seung-Hyeon
    • Korean Chemical Engineering Research
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    • v.51 no.5
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    • pp.615-621
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    • 2013
  • Membrane characterization methods for aqueous redox flow batteries aqueous RFBs were modified for non-aqueous RFBs. The modified characterization methods, such as ion exchange capacity, transport number, permeability and single cell test, were carried out to evaluate commercial membranes in non-aqueous electrolyte. It was found that columbic efficiency and energy efficiency in a single cell test were dependent on the ion selectivity of commercial anion exchange membranes. Neosepta AHA anion exchange membrane showed the anion transport number of 0.81, which is a relatively low ion selectivity in non-aqueous electrolyte, however, exhibited 92% of coulombic efficiency and 86% of energy efficiency in a single cell test. It was also found that a porous membrane without ion selectivity is suitable for a non-aqueous redox flow battery at a high current density.

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

  • 박재윤;고용술;이재동;손성도;박상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.5
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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
    • Korean Journal of Agricultural Science
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    • v.51 no.1
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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.