• Title/Summary/Keyword: distilled water

검색결과 2,421건 처리시간 0.034초

STORAGE OF BROCCOLI BY MAKING THE WATER STRUCTURED -Suppression of metabolism-

  • Oshita, S.;Seo, Y.;Kawagoe, Y.;Rahman, M.A.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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    • pp.918-925
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    • 1996
  • The effect of structured water by dissolution of xenon was examined from the view point of the suppression of both browning and respiratory metabolism of broccoli. The structured water is formed duet to hydrophobic interaction when xenon gas dissolves into water. NMR measurements were carried out to determine proton spin-spin relaxation time, T2, for water. There was a difference in proton T2 between distilled water and structured water. This can be interpreted as the change of water structure. Fro the broccoli cut in half stored for 16 days at 279K, the section color did not change appreciably for the sample whose water was structured by dissolution of xenon whose initial partial pressure was 0.39MPa. In contrast to this, the browning of section surface was observed for the sample stored under the condition of nitrogen gas at the same partial pressure as xenon and for the sample stored under atmospheric condition . These results led to the conclusion that the suppression of b owning by oxidation was due to structured water but not to applied pressure. Adding to this, the water structured by xenon has resulted in suppression of respiratory metabolism of broccoli.

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Evaluation of the membrane filtration and elution for detection of Giardia lamblia cysts in water (수중 Giardia lamblia cysts 검출을 위한 멤브레인 여과 및 용출에 대한 연구)

  • Hong, Uk-Seon;Kim, Gyeong-Ju;Lee, Gi-Se
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 춘계학술발표대회
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    • pp.422-423
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    • 2000
  • The protozoan parasite Giardia lamblia has been implicated as the causative agents of many outbreaks of waterborne intestinal illness. Accurate evaluation of Giardia lamblia removal in water treatment process requires a reliable method for measuring the concentrations of these pathogens in water. The relative recovery of Giardia cysts was assessed for seeded samples of distilled water. Cysts preparation was done by encystment in vitro. Membrane filtration was evaulated with cellulose acetate, polycarbonate, polypropylene, polyethersulfone, nylon membranes. Elution conditions were varied to improve cyst recovery.

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A Study on the Capillary Limitation in Copper-Water Heat Pipes with Screen Wicks (스크린 윅을 삽입한 동-물 히트파이프에서 모세관 한계에 관한 연구)

  • 박기호;이기우;노승용;이석호;유성연
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • 제14권12호
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    • pp.1023-1030
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    • 2002
  • This paper is to research the heat transfer characteristic performance of the copper-water heat pipe with the screen wicks. Recently, the semiconductor capacity of an electronic unit has been larger, on the contrary, its size has been much smaller. As a result, a high-performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling water and the mesh number of screen wicks. The distilled water was used for the working fluid. At the inclination angle $6^{\circ}$ in top heat mode, the two layers of the 100-mesh screen wick showed the best heat transfer performance. The thermal resistance of the two layers with the 100-mesh screen was 0.7~$0.8^{\circ}C$/W.

Effect of the Moisture Environment on the Mechanical Properties of Carbon Fiber Laminates (적층형 탄소섬유 복합재료의 기계적 성질에 미치는 수분환경의 영향)

  • Kim, Won-Keun;Moon, Chang-Kwon
    • Journal of Ocean Engineering and Technology
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    • 제13권4호통권35호
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    • pp.63-74
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    • 1999
  • This study has been investigated about the influence of moisture environment on the mechanical properties in the carbon fiber cross laminates. And it has been also investigated the effect of unit ply thickness of the carbon fiber cross laminates on the mechanical properties in distilled water of $80^{\circ}C$ for a certain period of time. As a results, it was found that the weight gain of water was increased with the immersion time and the bending strength and fracture toughness were decreased with the weight gain of water. And it was also shown that the bending strength and fracture toughness were decreased with the increasing of the unit ply thickness of carbon fiber cross laminates through the immersion time.

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Preparation of Self-standing Mesoporous Bioactive Glass/biodegradable Polymer Composite thin Films using Water Casting Method (수면전개법을 이용한 메조다공성 생체활성유리-생분해성 고분자 복합체 자립박막의 제조)

  • Yun, Hui-Suk;Yoon, Jun-Jin;Park, Eui-Kyun;Kim, Seung-Eon;Hyun, Yong-Taek
    • Journal of the Korean Ceramic Society
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    • 제45권10호
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    • pp.631-637
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    • 2008
  • Self-standing mesoporous bioactive glass/poly($\varepsilon$-caprolactone) composite thin films with good molding capability, bioactivity, and biocompatibility in vitro, which may find potential applications in tissue engineering and drug storage, were prepared using a combination of the sol-gel, polymer templating, and water casting method. The thickness of self-standing films was affected by the difference of dielectric constant between distilled water and organic solvent.

Thermal Performance of the Microencapsulated PCM

  • Lee, Hyo-Jin;Lee, Jae-Goo
    • International Journal of Air-Conditioning and Refrigeration
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    • 제10권1호
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    • pp.31-39
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    • 2002
  • Microencapsulated pcm (MPCM) particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane ($C_14$$H_30$, $T_m$=5.5$^{\circ}C$) is capsulated in the core, coated with the melamine for their surface. The size of particles is well-controlled under 10$\mu$m in the process of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentractions of slurries are prepared for 20 wt%, 30 wt%, and 40 wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose flow rates are varied by 125 cc/min, 250 cc/min, and 500 cc/min. However, MPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MPCM particles restrict their heat transfer in terms of natural convection and conduction to them.

Mercury Ion Removal Using a Packed-Bed Column with Granular Aminated Chitosan

  • JEON, CHOONC
    • Journal of Microbiology and Biotechnology
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    • 제15권3호
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    • pp.497-501
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    • 2005
  • This study deals with the removal of mercury species using a packed-bed column with spherical aminated chitosan material. These adsorbents revealed a high adsorption capacity for mercury species. Experiments with feed solutions of 10 ppm Hg dissolved in distilled water showed an excellent removal with a sharp increase of the filter effluent concentration after a total throughput of 900 bed volumes of feed water. Up to $95\%$ desorption was reached by using 3 bed volumes of 0.01 N EDTA solution. EDTA could be recovered by means of sulfuric acid with about $75\%$ efficiency. Almost the same results were obtained in repeated sorption and desorption experiments at identical conditions. The experiments demonstrated that the sorbents possessed practically no sorption capacity for alkaline earth ions ($Ca^{2+}\;and\;Mg^{2+}$). Their influence on the sorption of mercury was negligible. In experiments with spiked tap water of the Karlsruhe Research Centre and a feed mercury concentration of 0.01 mg/l, the breakthrough of Hg was observed only after a total throughput of about 6,000 bed volumes of feed water.

Effects of pH, Alkalinity, Chloride Ion on the Copper Pipe Corrosion (동관에서 pH, 알칼리도, 염소이온이 부식에 미치는 영향)

  • Jo, Kwan-Hyung;Kim, Sun-Il;Woo, Dal-Sik
    • Journal of Environmental Health Sciences
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    • 제33권1호
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    • pp.43-48
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    • 2007
  • This study investigated the effects of pH, alkalinity, and chlorine ion which are important water quality impact factors to the corrosion in the simulated distribution system where the copper pipe is affixed. The result shows that pitting index was increased as the alkalinity and chloride ion increase in the distilled water, but there was no relation to pH. Actually the uniform corrosion rate was decreased as the pH increase with the laboratory tap water. In conclusion, it is necessary to control the pH which stands above minimum 7.5 to prevent pitting corrosion in the copper pipe. Consequently, comprehensive research about the effect of lime soda($Ca(OH)_2$) which was used as a coagulation additive in the water treatment plant to pipe corrosion must be accomplished additionally.

Experimental Study on the Microencapsulated PCM as a Thermal Storage Medium (미립잠열재를 이용한 축열 특성에 관한 실험적 연구)

  • 이효진;이재구
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • 제13권2호
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    • pp.80-87
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    • 2001
  • Microencapsulated PCM particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane(C$_14H_30, T_m=5.5^{\circ}C$) is capsulated in the core with the melamine of its surface. The size of particles is well-controlled under 10${\mu}{\textrm}{m}$ in the way of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentrations of slurries are prepared for 20wt%, 30wt%, and 40wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose tank whose flow rates are varied by 125cc/min, 250cc/min, and 500cc/min. However, MicroPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MicroPCM particles control its heat transfer in terms of natural convection and conducting to them.

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Effects of Silkworm Extract on Disaccharidase Activities of Small Intestine and Blood Glucose-Lowering in C57BL/6J Mice

  • Ahn, Jung-Mo;Hong, Jung-Hee;Kim, Mi-Lim;Lee, In-Seon;Rhee, Soon-Jae
    • Preventive Nutrition and Food Science
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    • 제10권1호
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    • pp.34-39
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    • 2005
  • This study examined the anti-diabetic effect of a silkworm extract in C57BL/6J mice, an ob/㏈ model, fed a high fat diet for 8 weeks. The body weight was not significantly different with the silkworm-extract supplement, nor did food intake and body weight gains also did not differ significantly among the high-fat diet groups. However, the water intake by the silkworm-extract supplemented groups increased significantly compared with that by the distilled-water supplement group, nonetheless, the FER did not differ significantly. For all groups, the blood glucose increased the most after 30 minutes and yet returned to a fasting level within 90 minutes. The fasting time and resulting glucose tolerance for the silkworm-extract supplemented groups were significantly decreased compared to that for the high fat diet with distilled water supplement group, while the level of blood glucose in silkworm-extract supplemented groups was significantly decreased compared with than in the diabetic control group. The HbA1c and insulin levels were no different among the groups. The sucrase and lactase activities in the proximal small intestine were significantly decreased in the silkworm-extract supplement groups compared to that in the diabetic control group. There was no significant difference in the glycogen contents in the liver and muscle among the groups. In conclusion, it was found that the silkworm-extract supplement repressed the disaccharidase activity in the small intestines mucosa of the C57BL/6J mice.