• Title/Summary/Keyword: Fresh Water

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A Study on the Performance and Flow Distribution of Fresh Water Generator with Plate Heat Exchanger

  • Jin, Zhen-Hua;Kim, Pil-Hwan;Lee, Gyeong-Hwan;Choi, Soon-Ho;Chung, Han-Shik;Jeong, Hyo-Min
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.611-617
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    • 2008
  • Nowadays Plate Heat Exchanger (PHE) is widely used in different industries such as chemical, food and pharmaceutical process and refrigeration due to the efficient heat transfer performance, extreme compact design and efficient use of the construction material. In present study, discussed main conception of plate heat exchanger and applied in vacuum. PHE and aimed apply in the fresh water generator which installed in ship to desalinate seawater to fresh water use heat from engines. The experiment is proceeded to investigate the heat transfer between cold and hot fluid stream at different flow rate and supply temperature of hot fluid. Generated fresh water as outcome of the system. PHE is an important part of a condensing or evaporating system. One of common assumptions in basic heat exchanger design theory is that fluid is to be distributed uniformly at the inlet of each fluid side and throughout the core. However, in practice, flow mal-distribution is more common and can significantly reduce the heat exchanger performance. The flow and heat transfer are simulated by the k-$\varepsilon$ standard turbulence model. Moreover, the simulation contacted flow maldistribution in a PHE with 6 channels.

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Studies on the Thermostability of Myofibrillar Proteins from Fresh Water Fish and Sea Water Fish (담수어와 해수어의 근원섬유단백질의 열안정성에 관한 연구)

  • 신완철;송재철;최석영;홍상필
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.4
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    • pp.574-578
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    • 2001
  • Myofibrillar proteins were prepared from red muscle and white muscle of fresh water fish and sea water fish, and their thermostabilities and effect of temperature on the myofibrillar ATPase activities were compared. Differences in temperature dependency of myofibrillar ATPase activities were found between two species. Thermodynamic data for inactivation of myofibrillar proteins, such as D value, Z value, $\Delta$ $H^{{\neq}}$, $\Delta$ $G^{{\neq}}$ and $\Delta$ $S^{\neq}$ revealed that thermostabilities of myofibrillar proteins from fresh water fish were higher than those from sea water fish, and that myofibrillar proteins from red muscle were more heat labile than those from white muscle.

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Effect of Washing Methods and Surface Sterilization on Quality of Fresh-cut Chicory (Clchorium intybus L. var. foliosum) (세정 및 표면살균에 따른 신선편이 치커리 제품의 품질 특성 변화)

  • Kwon, Ju-Yeon;Kim, Byeong-Sam;Kim, Gun-Hee
    • Korean Journal of Food Science and Technology
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    • v.38 no.1
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    • pp.28-34
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    • 2006
  • Effects of various surface sterilization and washing methods on sterilization of fresh chicory surface were evaluated. Fresh-cut chicory was washed with tap water for 1 min, 100 ppm chlorinated water, and 3 ppm ozonated water using mechanical washing machine for 3 min, packed with bi-axially oriented polypropylene (OPP 0.04 mm) film, and stored for 3 weeks at 4 and $10^{\circ}C$. Tap water washing resulted in approximately 1 log CFU/g reduction of microbial load, and ozonated water and chlorinated water treatments resulted in additional 2 log CFU/g reduction.

Considerations of Permeability of Converter Slag by Laboratory and In-situ Tests (실내 및 현장시험에 의한 제강 슬래그의 투수성 고찰)

  • 이문수;이광찬
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.5
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    • pp.93-105
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    • 2001
  • The permeability of converter slag, replacing material of sand mat on improving soft clay foundation, was evaluated in the laboratory as well as in situ test. Effects of grain size, flow water time and aging were investigated using sea and fresh water Converter slag which has a grain size less than 10mm were submerged with fresh water and sea water. In fresh water, the coefficients of permeability in samples A and B were measured as 4.50${\times}$10$^{-2}$ cm per second and 1.20${\times}$10$^{-1}$ cm per second, respectively while as 1.88$\times$10$^{-2}$ cm per second and 3.86$\times$10$^{-1}$ cm per second in sea water. The condition of turbulent flow may exit and was experimentally certified based on the relationship of hydraulic gradient and seepage velocity. After 180 days in using sea water, the coefficients of permeability of samples A and B decreased ten times smaller than those initial values, and after that time continually decreased as for till 360 days. Finally, filling with voids in high-calcium quicklime(CaO) may result in the reduction of coefficient of permeability. In-situ coefficient of permeability however was Practically satisfactory.

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Yeast Microflora of Some Aquatic Habitats in El-Minia Governorate, Egypt

  • Haridy, Mamdouh S.A.
    • The Korean Journal of Mycology
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    • v.21 no.2
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    • pp.127-132
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    • 1993
  • 269 yeast strains were isolated from water samples collected from different sites in Minia governorate. These included 126 strains from fresh water, 108 strains from sewage and 35 strains from wastewater from sugar-cane factory. On the basis of 23 different physiological and morphological merkmals, the isolated strains were assigned to 16 species belonging to 11 genera. Total yeast cell counts as well as spectra of yeast species were highly variable in tested water. Total yeast cell counts ranged between $3.0{\times}10^3/l\;and\;1.8{\times}10^6/l$ for fresh water, $3.0{\times}10^4/l\;and\;3.0{\times}10^7/l$ for sewage and $1.5{\times}10^6/l\;and\;2.6{\times}10^7/l$ for wastewater from sugarcane factory. Debaryomyces hansenii, Rhodotorula mucilaginosa and Torulaspora delbrueckii were the dominant species in fresh water, whereas Debaryomyces hansenii, Thrichosporon beigelii, Rhodoforula mucilaginosa and Kluyveromyces marxianus were the dominant species in sewage and Saccharomyces cerevisiae, Kluyveromyces marxianus and Trichosporon beigelii were the dominant species in wastewater from sugar-cane factory. Yeast human pathogens, Trichosporon beigelii, Rhodotorula mucilaginosa and Candida albicans were encountered in water samples indicating that water in El-Minia governorate is also polluted by some pathogenic yeasts.

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READABILITY TEST OF RFID TEMPERATURE SENSOR EMBEDDED IN FRESH CONCRETE

  • Julian Kang;Jasdeep Gandhi
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.754-757
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    • 2009
  • The current concrete maturity method implemented with temperature sensors requires an extensive wiring, which is not often acceptable on construction site due to harsh working environment. Radio Frequency Identification (RFID) technology appears to provide a solution for the wiring issue because of its ability of sending data wirelessly. An RFID tag integrated with a temperature sensor and placed within fresh concrete may be able to read temperatures of concrete and transmit them to an RFID reader wirelessly in real-time. However the previous research illustrated that the RFID signal gets dispersed in liquid medium. One may speculate then whether RFID signals travel through fresh concrete with high water content. Would the tag's burying depth within fresh concrete affect its readability? The paper presents the preliminary results of our on-going investigation on the readability of RFID tags in concrete against water content and burying depth of tags.

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Control Algorithm Development for Design of Cooling System in High-power Propulsion Motor (대용량 전기추진시스템 설계를 위한 제어알고리즘 개발)

  • Oh, Jin-Seok;Jung, Sung-Young;Kong, Yeong-Kyung;Bin, Jae-Goo;Kim, Han-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.1
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    • pp.195-201
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    • 2010
  • In this paper, a cooling system of high-power propulsion motor with Energy Saving System(ESS) is described. Normally, the cooling system for ship consists of fresh water pump, sea water pump, 3-way valve and cooler. In the cooling system, F.W(Fresh Water) and S.W(Sea Water) pump is operated on rated rpm, and the 3-way valve is controlled for preventing over-cooling. So, the consumption power of pump's motor is changed according to a sea water temperature. In the proposed cooling system, F.W. pump and S.W pump is controlled by inverter, and it is can be reduced the consumption power. Also, it is proved with simulation.

Influence of Aggregate Factor on the Estimation of Water Content in Fresh Concrete (굳지않은 콘크리트의 단위수량 추정에 미치는 골재요인의 영향)

  • 김영득;황인성;전충근;한천구;김광서
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.223-226
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    • 2002
  • This study is performed to investigate the influence of aggregate factor on the estimation of water content in fresh concrete. According to the results, water content is estimated higher in the case of basalt and granite aggregate than in the case of limestone because absorption water ratio of basalt and granite is large. As the replacement ratio of recycled aggregate increases, water content is estimated higher. But, after correcting absorption water ratio of aggregate, estimated water content is similar to mixture water content. Therefore, it is important to know the absorption water ratio of aggregates accurately, to estimate water content.

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Effects of a Combined Treatment of Hot Water with Green Tea Extract and NaCl on the Postharvest Quality of Fresh-cut Burdocks

  • Chang, Min-Sun;Kim, Gun-Hee
    • Horticultural Science & Technology
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    • v.33 no.3
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    • pp.364-374
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    • 2015
  • This study investigated quality changes in fresh-cut burdocks treated with hot water and anti-browning agents. The combined treatment using both heat treatment and anti-browning agents delayed the browning of burdocks, especially for those dipped in hot water and a solution of green tea extract plus NaCl. This treatment reduced the respiration rate and inhibited the growth of microorganisms more than heat treatment alone. The organoleptic quality of burdocks treated with the combined method proved to be the best according to sensory evaluation. Hence, this combined treatment using heat and anti-browning agents can enhance overall quality of processed fresh-cut root vegetables by browning inhibition and shelf-life extension.

Modeling of Steam Injection Heater for Fresh Water Generator (조수기용 증기분사 열교환기에 대한 모델링)

  • Hong, Cheol-Hyun;Lee, Euk-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.6
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    • pp.877-885
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    • 2008
  • Steam injection heater is the most widely used method for fresh water generator throughout industry. This method is often chosen because of its simplicity. The steam bubbles condense and give up their heat to the surrounding liquid. Experimental study on steam injection heater has been performed in order to find the effect of major parameter. And conservation equation and Bernoulli obstruction theory are used for numerical simulation model of vapor flow-rate. Qualitative comparisons between simulations and measurements show a good agreement and the simulation models are thereby verified.