• Title/Summary/Keyword: removal time of form

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Treatment of Acid Mine Drainage Using Immobilized Beads Carrying Sulfate Reducing Bacteria (황산염환원균 고정화 담체를 이용한 산성광산배수 처리)

  • Kim, Gyoung-Man;Hur, Won;Baek, Hwan-Jo
    • Economic and Environmental Geology
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    • v.41 no.1
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    • pp.57-62
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    • 2008
  • The application of constructed subsurface-flow wetlands for treatment of wastewater from abandoned mines is being increased. Crushed limestone, oak chips, and mushroom composites are often employed in a bulk form, as the substrates in the bed media. Efficiency of the subsurface-flow treatment system drops with time as the hydraulic conductivity of the wetland soil decreases significantly, presumably due to chemical reactions with the wastewater. The purpose of this study is to investigate the applicability of immobilized beads carrying sulfate reducing bacteria for acid mine drainage treatment system. The ingredients of immobilized beads are organic materials such as mushroom composite and oak chips, limestone powder for a pH buffer, mixed with a modified Coleville Synthetic Brine. It was found that immobilized beads are more efficient than the bulk form for pH recovery, sulfate and heavy metal removal.

An Experimental Study on Strength Properties of Early Strength Concrete for Reduction of Working Period in Apartment (공동주택 공기단축을 위해 개발된 조강 콘크리트의 강도 발현 특성에 관한 연구)

  • Jung, Yang-Hee;Lee, Jae-Hyun;Keum, Kyoung-Hun;Lee, Won-AM;Kim, Sun-Man
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.157-160
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    • 2009
  • The decision of the Form removal time which leads the early assuring strength of the concrete from Apartment construction is the fact which is important from Reducing the period of works and the economical efficiency side. Especially, with Complex building of recent times the same Tall building and Multiple Apartment Site which only follows in upgrade of interior construction of apartment site and shortening the frame construction period becomes very, importantly is the actual condition where the effort which is various for this is attempted. But is caused by with limit and economical efficiency problem of case concrete early strength revelation of most and is not put to practical use is the actual condition. Develops concrete mixture which is a utility from the research which sees hereupon and the effect which is economic leads construction duration shortening under maximizing boil.

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Formation of Spheroids of Adult Rat Primary Hepatocytes in Polyurethane Foam (폴리우레탄 폼을 이용한 쥐 일차 간세포의 구상체 배양)

  • 안재일;이두훈
    • Journal of Biomedical Engineering Research
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    • v.19 no.3
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    • pp.215-224
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    • 1998
  • This paper is fundamental study to develope the extracorporeal liver support system for patient with fulminant hepatic failure(FHF) or being expected for orthotopic liver transplantation. The polyurethane foam, which is composed of the density of 33kg/m3, the average pore diameter of 500${\mu}{\textrm}{m}$, the closed window of 60-70%, was manufactured with the prepolymer of 15% NCO-, Hepatocytes were inoculated to form spheroids in polyurethane foam. The time of spheroid formation in BSA(Bovine Serum Albumin) coated polyurethane foam was shorter than that in raw polyurethane foam. To verify the function of hepatocyte spheroids, we measured ammonia removal rate, urea and albumin secretion rate. Polyurethane foam was suitable for culture of hepatocyte spheroids. And culture of hepatocyte spheroids in polyurethane foam has high possibility in using as an extracorporeal liver support system.

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A Study on the Pb-contaminated Soil Remediation by Organic Acid Washing (유기산을 이용한 납 오염토양의 복원에 관한 연구)

  • 정의덕
    • Journal of Environmental Science International
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    • v.9 no.5
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    • pp.437-441
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    • 2000
  • A study on the removal of Pb ion from Pb-contaminated soil was carried out using ex-site extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt(IDA) as a washing agent were evaluated as a function of concentration reaction time mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1:15 and 1:20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction were 368.8 ppm and 267.5 ppm respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide form the precipitation of lead hydroxide and lead sulfide and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/$\ell$ for the TA washing solution and 4 g/$\ell$, 5g/$\ell$ for the IDA washing solution respectively. The efficiency of recycle for TA and IDA washing solution were 78.8% , 95.1%, and 89.2%, 96.6% at third extractions under $Na_2S$ and $Ca(OH)_2$, respectively.

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Disinfection Characteristics of Waterborne Pathogenic Protozoa Giardia lamblia

  • Kim, Kyongjoo;Wooksun Hong;Lee, Kisay
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.2
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    • pp.95-99
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    • 2001
  • Giardia lamblia is a parasitic protozoa which is transmitted in the form of a cyst through untreated water and also treated drinking water. Since its presence in water has led to frequent outbreaks of giardiasis and death in many countries, the removal and disinfection of this protozoan cyst from the water supply are of great concern for public health. This study examined the disinfection characteristics of G. lamblia cysts isolated from a Korean patient with giardiasis. When using sodium hypochlorite including 5 or 10 ppm chlorine, the killing rate was initially rapid, however, the disinfection slowed down and a 3log reduction could not be achieved even after 2h. The disinfection effectiveness was also reduced at a lower temperature, thereby implying that the risk o a giardiasis outbreak will be higher in the winter season. A CT (concentration$.$time) curve was constructed based on the results with sodium hypochlorite for use in designing and predicting disinfection performance. The organic chlorination disinfectant SDIS (sodium dichloroisocyanurate) produced a lower pH and a much higher residual effect than sodium hypochlorite. The disinfection of cysts by SDIC continued steadily throughout 2h of contact, although the initial killing rate was lower than that with sodium hypochlorite.

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Development portable hair removal applies PET ($Pause^{10-90}$ and $Energy^{20-40}$ $Trigger^{1-7}$) function

  • Kim, Whi-Young
    • Journal of information and communication convergence engineering
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    • v.7 no.2
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    • pp.223-230
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    • 2009
  • For pulse trigger way and the energy injection rate according to PET ($Pause^{10-90}$ $Energy^{20-40}$ $Trigger^{1-7}$) function, indeed, human body condition, period of dormancy in this research about this back correctly adjustment possible and designed harmless micro carrying along style hair exclusion so that can design and manufacture and run special quality examination and Xenon flash lamp to crawl in human body. Because creating individual's skin model to do stable treatment by light transmission way by skin impedance and measure, must embody treatment special quality of most suitable that draw skin color, energy, wave length, approximately, transmission time, pulse delay etc. and want. Specially, saved standard of war treatment pulse modeling by skin impedance, and manufacture pulse modeling system of most suitable by skin subordinate, and embody suitable treatment pulse. Specially, embody as could do root of a hair exclusion being emitted in pulse form using multi wave length of 560nm, 590nm, 640nm, 755nm and embodied clinical data. If become research repletion furthermore little more, is seen that can approximate in commercialization.

Superconducting transitions of LuBa2Cu3O7-z heated under various atmospheres

  • Lee, M.S.;Lee, H.K.
    • Progress in Superconductivity and Cryogenics
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    • v.16 no.1
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    • pp.6-8
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    • 2014
  • The influence of quenching temperature, heating atmosphere and annealing time on superconducting characteristics has been studied for $LuBa_2Cu_3O_{7-z}$ compound which has been recently synthesized in a nearly phase-pure form. Resistivity measurements for the as-prepared sample heated at $300^{\circ}C$ in oxygen and subsequently quenched into liquid nitrogen revealed that there is no significant change in $T_c$. On the other hand, $T_c$ of the sample slightly increased when the sample was heated at $300^{\circ}C$ either in air or in $N_2$ atmosphere. It was also found that $T_c$ of the sample decreased when the annealing temperature in $N_2$ atmosphere increased above $400^{\circ}C$. The experimental results indicated that the as-prepared sample is under overdoped state. The enhanced superconducting transition observed in the samples after heating at $300^{\circ}C$ in air or $N_2$ atmosphere was discussed in conjunction with a slight removal of oxygen and ordering of oxygen atoms in the as-prepared sample.

Effects of Oxalic and L-ascorbic acids on Iron Removal form Iron-bearing Illite (일라이트 분체 내에 함유된 산화철 제거에 옥살산과 L-아스코르브산이 미치는 영향)

  • Lee, Won-Pyo;Kang, Il-Mo;Moon, Hi-Soo
    • Economic and Environmental Geology
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    • v.40 no.2 s.183
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    • pp.141-151
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    • 2007
  • This study was focused on iron removal from illite by L-ascorbic and oxalic acids. Iron has been shown as a secondary mineral such as iron oxides and hydroxides in illite ores. It is also known as a primary agent to degrade brightness index of the ores. Methods such as physical separation and chemical leaching with strong inorganic acids have been widely used to remove the iron from the ores. However, these methods are expensive and give rise to environmental problems. In this study, we examined an alternative method using solutions with different set of combination of sulfuric, hydrochloric, L-ascorbic, and oxalic acids. Compared to chemical treatments with only inorganic acids, our results demonstrate that an addition of L-ascorbic acid in inorganic acids results in decreasing both total concentrations of the inorganic acids and time for the treatments. The treatment with 0.15 M L-ascorbic acid and 0.25 M sulfuric acid in solution for 60 min significantly improved the brightness index from 42.4% to 74.4%. This improvement is similar to that of treatment with only 2.5 M sulfuric acid alone for 150 min. Mineralogical and chemical analyses were performed to compare the effect of acid leaching on illite powders. No obvious differences are observed in the mineralogical characteristics and particle size distributions of the samples. These results suggest that the treatment with the addition of L-ascorbic acid in sulfuric acid could effectively remove iron without modifying the physicochemical properties of illite under conditions used in this study.

Behavioral Characteristics of Bos indicus Cattle after a Superovulatory Treatment Compared to Cows Synchronized for Estrus

  • Jimenez, A.;Bautista, F.;Galina, C.S.;Romero, J.J.;Rubio, I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.10
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    • pp.1365-1371
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    • 2011
  • The intensity and duration of sexual behavior in Bos indicus was assessed through the continuous observation of sexual receptivity. Two groups of cows were formed: only synchronized (n = 50) and other group further superovulated (n = 20). An intravaginal implant that released progesterone over 9 d was used. After removing the implant, 25 mg of $PGF_{2{\alpha}}$ was administered. In the superovulated group, the administration of 280 mg (Follicle stimulant hormone) FSH-P1 per cow with a decreasing dosage over 4 d was utilized. In both groups, behavioral observations began at the moment of implant removal. Sexual behavior was analyzed using a Kruskal-Wallis test to compare the mean of hours in estrus, effective mountings and number of mounts/hour during estrus. A nonparametric survival analysis was performed using the time in two ways: i) when an event happened it was placed in a 24 h timeframe and, ii) the time of observation in continuous form (96 h) assessing the difference between curves by the log rank test Chi-square. The only significant difference was the number of mounts/h during receptivity (p<0.05). In the superovulated group three periods of sexual activity during the day were identified, with these events being of greater frequency and duration than the synchronized group (p = 0.02); besides, the superovulated group began estrus before the synchronized group (p = 0.0035) when using the total period. In a simulation study, when the number of observations went from two (06:00-18:00) to three periods (06:00, 12:00 and 18:00) cows detected accurately (<6 h after the onset) increased more than 20%. The results show that superovulated cows presented greater intensity and duration of sexual activity in contrast with only synchronized animals.

Cutting Fluid Effluent Removal by Adsorption on Chitosan and SDS-Modified Chitosan

  • Piyamongkala, Kowit;Mekasut, Lursuang;Pongstabodee, Sangobtip
    • Macromolecular Research
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    • v.16 no.6
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    • pp.492-502
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    • 2008
  • This study examined the adsorption of a synthetic cutting fluid and cutting fluid effluent on chitosan and SDS-modified chitosan, Chitosan and SDS-modified chitosan were prepared in form of beads and fibers. A series of batch experiments were carried out as a function of the initial concentration of cutting fluid, contact time and pH of the fluid. The contact angle study suggested that the SDS-modified chitosan was more hydrophobic than chitosan. The Zeta potential study showed that chitosan, SDS-modified chitosan and synthetic cutting fluid had a point of zero charge (PZC) at pH 7.8, 9 and 3.2, respectively. SDS-modified chitosan has a greater adsorption capacity than chitosan. The experimental results show that adsorption capacity of the cutting fluid on 1.0 g of SDS-modified chitosan at pH 3 and for a contact time of 120 min was approximately 2,500 g/kg. The adsorption capacity of chitosan and SDS-modified chitosan increased with decreasing pH. The Langmuir, Freundlich, and Brunauer Emmett and Teller (BET) adsorption models were used to explain the adsorption isotherm. The Langmuir isotherm fitted well with the experimental data of chitosan while the BET isotherm fitted well with the SDS-modified chitosan data. Pseudo first- and second-order kinetic models and intraparticle diffusion model were used to examine the kinetic data. The experimental data was fitted well to a pseudo second-order kinetic model. The significant uptake of cutting fluid on chitosan and SDS-modified chitosan were demonstrated by FT-IR spectroscopy, SEM and heat of combustion.