• Title/Summary/Keyword: brine

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Control of redtide microbes with hydrogen peroxide and yellow loess (과산화수소와 황토를 이용한 적조생물의 제어)

  • Seok, Jong-Hyuk;Jun, Se-Jin
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.4
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    • pp.491-497
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    • 2009
  • The purpose of this study is to propose a method of controlling redtide microbes which grow abundantly and form harmful algal bloom in eutrophic waterbody with yellow loess and hydrogen peroxide. In the laboratory test, hydrogen peroxide was applied to single species of C. polykrikoides and multispecies of redtide microbes. The seawater was evaluated by the pre-test analysis including chlorophyll-a, luminance and transmittance. The test results showed that both single and mixed species of redtide microbes could be controlled with the dose of 30mg $H_2O_2/L$. Residual hydrogen peroxide was completely decomposed with the addition of powdered yellow loess at 2g/L~10g/L. However, the decomposition rate of residual hydrogen peroxide for sintered granular yellow loess was relatively low compared to the use of powdered one. With the addition of dissolved oxygen concentration was increased at a rate of 0.013 mg DO/mg $H_2O_2$, which is a little lower than the one predicted theoretically. No evidence for any detrimental effects on Artemia, a type of brine shrimps, was shown up to the concentration of 100mg $H_2O_2/L$.

Study on the Frosting Phenomenon of the Fin and Tube Heat Exchanger with a Louvered Fin (루버형 휜을 가진 휜관형 열교환기의 착상현상 연구)

  • Kim, Jung-Kuk;Kuwahara, Ken;Koyama, Shigeru;Park, Byung-Duck
    • Journal of the Korean Society of Industry Convergence
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    • v.11 no.4
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    • pp.157-163
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    • 2008
  • The present study investigated the pressure drop and the total frost mass of the louvered fin type heat exchanger, which is widely used at the air-conditioning system. The pressure drop due to the frosting phenomenon and the total frost mass were investigated by changing the wet bulb temperature condition of the inlet air. Hence the brain of 55wt% was used as a cooling solution instead of a common refrigerant. The temperature difference between the brine and the tube outside wall at the outlet of heat exchanger was $10^{\circ}C$, at maximum, higher than that at the inlet of heat exchanger. As the wet bulb temperatures were increased, the pressure drop was linearly increased due to the increment of frost mass. And the increment of heat exchange rate was smaller than that of inlet air enthalpy due to the increment of frost mass. The pressure drop of air side was rapidly increased due to the progress of frosting phenomena. The run time that the pressure drop occurred rapidly was decreased by the growth of frost.

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Phytochemical and biological investigations of Polygonum lanatum

  • Chowdhury, Sadia A.;Sohrab, Mohammad H.;Haque, Mohammad R.;Hasan, Choudhury M.;Rashid, Mohammad A.
    • Advances in Traditional Medicine
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    • v.8 no.1
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    • pp.97-102
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    • 2008
  • A total of five compounds namely, 2-methylanthracene-9, 10-dione (1), 1-hydroxy-6-methylanthracene-9,10-dione (2), $\beta$-sitosterol (3), stigmasterol (4) and sitosterone (5) were isolated from the stem extracts of Polygonum lanatum for the first time. The structures of the isolated compounds (1-5) were established by extensive spectroscopic studies, including 2D NMR such as $^{1}H-^{1}H$ COSY, HSQC and HMBC studies. The crude extracts and purified compound (1) were screened for antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria and fungi by the disc diffusion method. The n-hexane and dichloromethane soluble partitionates of the methanolic extract revealed mild to moderate inhibition of growth of the test organisms. The cytotoxic potential of the extractives and compound 1 was also determined by using brine shrimp lethality bioassay, where the extractives demonstrated significant cytotoxic activities.

Effect of Pressurization and Cooling Rate on Dissolution of a Stationary Supercooled Aqueous Solution (정지상태 수용액에서 가압과 냉각속도가 과냉각해소에 미치는 영향)

  • Kim, Byung-Seon;Peck, Jong-Hyun;Hong, Hi-Ki;Kang, Chae-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.12
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    • pp.850-856
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    • 2007
  • In a supercooled or capsule type ice storage system, aqueous solution (or water) may have trouble with non-uniform dissolution though the system contributes to the simplicity of system and ecological improvement. The non-uniform dissolution increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to observe the supercooled state, a cooling experiment was performed with pressurization to an ethylene glycol(EG) 3 mass% solution in stationary state. Also, the effect of the pressurization from 101 to 505 kPa to the dissolution of supercooled aqueous solution was measured with the dissolution time of the supercooled aqueous solution at a fixed cooling rate of brine. At results, the dissolution of supercooled point decreased as the pressure of the aqueous solution in the vessel increased. Moreover, the dissolution point increased as the heat flux for cooling increased.

Analytical Study on the Performance of Fuel Cell Driven Ground Source Heat Pump Heating and Cooling System of a Large Community Building (대형 Community 건물의 연료전지 구동 지열원 히트펌프 냉.난방 시스템 성능에 관한 해석적 연구)

  • Byun, Jae-Ki;Jeong, Dong-Hwa;Choi, Young-Dong;Cho, Sung-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.6
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    • pp.355-366
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    • 2009
  • In the present study, fuel cell driven ground source heat pump system is applied to a large community building and performance of the heat pump system is computationally analyzed. Conduction heat transfer between brine pipe and ground is analyzed by TEACH code to predict the performance of heat pump system. Predicted COP of the heat pump system and the energy cost were compared with variation of the location of the objective building the water saturation rate of soil and the driven powers of heat pump system. Significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system in comparison with the late-night electricity driven system. It is due to the low electricity production cost of fuel cell system and the application of recovered waste heat generated during electricity production process to the heating of large community building.

Microbiological Properties of Oiji (Korean Pickled Cucumbers) by the Addition of Pulsatilla koreana (할미꽃(백두옹, Pulsatilla koreana) 첨가량에 따른 오미지의 미생물학적 특성)

  • Han Bok-Ryo;Moon Hye-Kung;Jo Jung-Soon;Kim Jong-Kook;Kim Gwi-Young;Kim June-Han
    • Journal of the East Asian Society of Dietary Life
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    • v.15 no.5
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    • pp.613-618
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    • 2005
  • This study was performed to analyze the microbiological properties of Oiji soaking solution and Oiji preserved with $7\%$ brine and the others preserved with Pulsatilla koreana additives of various concentration$(0,\;3,\;6,\;9\%)$ during fermentation(24 days) at room temperature$(20\pm2^{\circ}C)$. The results of this experiment are as follows: The total number of microbes showed radical increase up to 6th day of growth period and decreased afterwards. Growth of microbes was impeded in the beginning of fermentation in the case of adding $6\%$ Pulsatilla koreana. The number of lactic acid bacteria tended to increase progressively until 15th day and then decreased, and that in the group of $6\%$ Pulsatilla koreana was relatively lower than those of other groups. Antimicrobial activity against Staphylococcus aereus and Micrococcus luteus was shown weakly from 9th day of fermentation regardless of the concentration of Pulsatilla koreana additives, but inactivated after 21st day of fermentation.

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Biological Screening of a Novel Nickel (II) Tyrosine Complex

  • Islam, Md. Rafiqul;Islam, S.M. Rafiqul;Noman, Abu Shadat Mohammod;Khanam, Jahan Ara;Ali, Shaikh Mohammad Mohsin;Alam, Shahidul;Lee, Min-Woong
    • Mycobiology
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    • v.35 no.1
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    • pp.25-29
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    • 2007
  • A newly synthesized Nickel (II) tyrosine complex was screened as potential antimicrobial agent against a number of medically important bacteria (Bacillus subtilis, Streptococcus ${\beta}$-haemolytica, Escherichia coli, Shigella dysenterae) and fungi (Aspergillus fumigatus, Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium sp.) strains. were used for antifungal activity. The antimicrobial activity was evaluated using the Agar Disc method. Moreover, the minimum inhibitory concentration of the complexes was determined against the same pathogenic bacteria and the values were found between $4{\sim}64\;{\mu}g\;ml^{-1}$. Brine shrimp bioassay was carried out for cytotoxicity measurements of the complexes. The $LC_{50}$ values were calculated after probit transformation of the resulting mortality data and found to be 6 ${\mu}g\;ml^{-1}$.

Simulation and Energy Cost Calculation of Encapsulated Ice Storage System (캡슐형 빙축열시스템에 대한 운전 시뮬레이션 및 에너지비용 분석)

  • Lee, K.H.;Joo, Y.J.;Choi, B.Y.;Kim, S.J.
    • Solar Energy
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    • v.19 no.3
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    • pp.63-73
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    • 1999
  • Ice storage systems are used to shift the peak load in day time into night time in summer. This paper describes a system simulation of partial ice storage system composed of an encapsulated ice storage tank, a screw compressor chiller, a heat exchanger, and a brine pump. For the system simulation, a one-dimensional model of ice storage tank is developed and validated by comparison with the performance data from measurements of an ice storage tank installed at a building. The control strategies considered in this study are chiller priority and storage priority being used commercially. The system is simulated with design cooling load of 600 RT peak load in design day and with off-design day cooling load, and the electric energy costs of the two control strategies for the same system size are compared. As a result of calculation, the energy consumption in a week for storage priority is higher than that for chiller priority control. However due to lower cost of night electric charge rate, energy cost for storage priority control is lower than chiller priority.

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Oxidants and Antioxidants Associated with Commercial Pickle Products and Ingredients (상업적인 pickle product와 ingredient의 oxidant와 antioxidant로서의 역할)

  • Jang, Mi-Jin;Cho, Il-Young;Joo, Hyun-Kyu
    • Applied Biological Chemistry
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    • v.38 no.5
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    • pp.408-413
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    • 1995
  • Investigations of the effects of pickle product ingredients on lipoxygenase (LOX) and methemoglobin (MHG, a nonenzymatic oxidant) catalyzing oxidation of linolenic acid were conducted. In addition, activities of LOX, peroxidase (POD) and catalase (CAT) in dry spices used in pickle products were determined. Some commercial pickle brines were observed to inhibit oxidation of linolenic acid by LOX and MHG. The ingredients in pickle products, such as dill oil emulsion, onion concentrate, oil cassia, polysorbate 80 and turmeric acid, reduced LOX and MHG catalyzed oxidation. Lipoxygenase activity was present in garlic, mustard seed and red pepper. Only in mustard seed, peroxidase activity was observed. Catalase activity was observed in garlic, black pepper, allspice and red pepper.

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Wewakamide A and Guineamide G, Cyclic Depsipeptides from the Marine Cyanobacteria Lyngbya semiplena and Lyngbya majuscula

  • Han, Bingnan;Gross, Harald;Mcphail, Kerry L.;Goeger, Doug;Maier, Claudia S.;Gerwick, William H.
    • Journal of Microbiology and Biotechnology
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    • v.21 no.9
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    • pp.930-936
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    • 2011
  • Two new cyclic depsipeptides wewakamide A (1) and guineamide G (2) have been isolated from the marine cyanobacterium Lyngbya semiplena and Lyngbya majuscula, respectively, collected from Papua New Guinea. The amino and hydroxy acid partial structures of wewakamide A and guineamide G were elucidated through extensive spectroscopic techniques, including HR-FABMS, 1D $^1H$ and $^{13}C$ NMR, as well as 2D COSY, HSQC, HSQC-TOCSY, and HMBC spectra. The sequence of the residues of wewakamide A was determined through a combination of ESI-MS/MS, HMBC, and ROESY. Wewakamide A possesses a ${\beta}$-amino acid, 3-amino-2-methylbutanoic acid (Maba) residue, which has only been previously identified in two natural products, guineamide B (3) and dolastatin D (4). Although both new compounds (1,2) showed potent brine shrimp toxicity, only guineamide G displayed significant cytotoxicity to a mouse neuroblastoma cell line with $LC_{50}$ values of 2.7 ${\mu}M$.