• Title/Summary/Keyword: initial dilution

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Near-Field Hydrodynamic Analysis of the Submerged Thermal Discharge Using CFD Model (CFD 모델을 이용한 수중방류 온배수의 근역 동수역학 해석)

  • Hwang, In-Tae;Kim, Deok-Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.6
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    • pp.466-473
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    • 2011
  • The buoyancy and initial momentum fluxes make near-field dominated by buoyant jet when thermal discharge releases underwater. In order to estimate prediction capabilities of those near-field phenomena, non-hydrostatic RANS applied CFD(Computational Fluid Dynamic) model was used. Condition of model was composed based on past laboratory experiments. Numerical simulations carried out for the horizontal buoyant jet in the stagnant flow and vertical buoyant jet into crossflow. The results of simulation are compared with the terms of trajectory and dilution rate of laboratory experiments and analytic model(CorJET) results. CFD model showed a good agreement with them. CFD model can be appropriate for assessment of submerged thermal discharge effect because CFD model can resolve the limitations of near-field analytic model and far-field quasi 3D hydrodynamic model. The accuracy and capability of the CFD model is reviewed in this study. If the computational efficiency get improved, CFD model can be widely applied for simulation of transport and diffusion of submerged thermal discharge.

Culture Optimization for Bacillus lentimorbus G-74 by Using a Miscanthus purpurascens Juice Medium (억새즙액 배지를 이용한 Bacillus lentimorbus G-74 균주의 배양 최적화)

  • Kang, Sun-Chul;Seo, Hae-Jeong
    • Korean Journal of Environmental Agriculture
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    • v.23 no.1
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    • pp.68-74
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    • 2004
  • Miscanthus purpurascens Juice containing potassium (37,952 mg/L), nitrogen (14,000 mg/L), phosphorus (6,800 mg/L), magnesium (5,969 mg/L), calcium (5,910 mg/L), etc., was investigated to develop a novel meidum far the mass cultivation of useful microorganisms. For this research, we first isolated an antagonistic bacterium G-74 from soil, which showed strong growth inhibition against two phytopathogenic fungi, Rhizoctonia solani and Botrytis cinerea, and identified as Bacillus lentimorbus G-74 based on the morphological characteristics and MIDI analysis. Culture conditions for G-74 strain in the M. purpurascens juice medium were optimized. Dilution rate of the medium, temperature and initial pH for the optimum growth of G-74 strain were 30% (V/V), $35^{\circ}C$ and 5.0, respectively. It was found that additions of 2.0% (W/V) corn starch as a carbon source and 1.0% (W/V) yeast extract as a nitrogen source in this medium increased B. lentimorbus G-74 growth to 66% more efficient than Luria Bertani medium.

The Acute and Chronic Toxicity Effects of Triorganotins on the Growth of Microalgae, Skeletonema costatum (미세조류, Skeletonema costatum의 성장에 미치는 유기주석 화합물들의 급성 및 만성 독성효과)

  • Ham Kyung Hoon;Kim Moo Sang;Lee Hyung Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.5
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    • pp.534-541
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    • 2002
  • The use of triorganotins as insecticides, bacteriocides, and antifouling agents has increased dramatically over the past 30 years, In this paper, to evaluate the acute and chronic toxicity effects of various triorganotins (TBTO, TBTE, CTPT, TBTCI) on the growth of microalgae, Skeletonema costatum, we carried out the short term and long term experiments, respectively. In the short-term experiments, the growth of S. costatum was inhibited by the various triorganotins in the dose dependent manners, but recovered by the time laps. The growth inhibition of triorganotins were decreased in the groups with higher initial cell density. These data were resulted from the dilution effect and the biodegradation of triorganotins by the microalgae. In the long-term experiments, S. costatum died completely at the 1 $\mu$g/L of TBTP and CTPT, but didn't in short-term experiments. The facts suggest that the toxicity of the chronic exposure of triorganotins should be increased in the natural sea water with low phytoplankton density.

Fabrication of Highly Efficient Nanocrystalline Silicon Thin-Film Solar Cells Using Flexible Substrates (유연기판을 이용한 고효율 나노결정질 실리콘 박막 태양전지 제조)

  • Jang, Eunseok;Kim, Sol Ji;Lee, Ji Eun;Ahn, Seung Kyu;Park, Joo Hyung;Cho, Jun-Sik
    • Current Photovoltaic Research
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    • v.2 no.3
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    • pp.103-109
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    • 2014
  • Highly efficient hydrogenated nanocrystalline silicon (nc-Si:H) thin-film solar cells were prepared on flexible stainless steel substrates using plasma-enhanced chemical vapor deposition. To enhance the performance of solar cells, material properties of back reflectors, n-doped seed layers and wide bandgap nc-SiC:H window layers were optimized. The light scattering efficiency of Ag back reflectors was improved by increasing the surface roughness of the films deposited at elevated substrate temperatures. Using the n-doped seed layers with high crystallinity, the initial crystal growth of intrinsic nc-Si:H absorber layers was improved, resulting in the elimination of the defect-dense amorphous regions at the n/i interfaces. The nc-SiC:H window layers with high bandgap over 2.2 eV were deposited under high hydrogen dilution conditions. The vertical current flow of the films was enhanced by the formation of Si nanocrystallites in the amorphous SiC:H matrix. Under optimized conditions, a high conversion efficiency of 9.13% ($V_{oc}=0.52$, $J_{sc}=25.45mA/cm^2$, FF = 0.69) was achieved for the flexible nc-Si:H thin-film solar cells.

Ethanol Production by Repeated Batch and Continuous Fermentations by Saccharomyces cerevisiae Immobilized in a Fibrous Bed Bioreactor

  • Chen, Yong;Liu, Qingguo;Zhou, Tao;Li, Bingbing;Yao, Shiwei;Li, An;Wu, Jinglan;Ying, Hanjie
    • Journal of Microbiology and Biotechnology
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    • v.23 no.4
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    • pp.511-517
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    • 2013
  • In this work, a fibrous bed bioreactor with high specific surface area and good adsorption efficacy for S. cerevisiae cells was used as the immobilization matrix in the production of ethanol. In batch fermentation, an optimal ethanol concentration of 91.36 g/l and productivity of 4.57 g $l^{-1}\;h^{-1}$ were obtained at an initial sugar concentration of 200 g/l. The ethanol productivity achieved by the immobilized cells was 41.93% higher than that obtained from free cells. Ethanol production in a 22-cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in packed-bed reactors, a maximum ethanol concentration of 108.14 g/l and a productivity of 14.71 g $l^{-1}\;h^{-1}$ were attained at $35^{\circ}C$, and a dilution rate of 0.136 $h^{-1}$ with 250 g/l glucose.

Cost Analysis of Ocean Outfall and Tertiary Treatment Processes in Suyong Sewage Treatment Plant (수영 하수처리장 방류수의 해중 방류법과 3차 처리시설 설치시 비용 비교 분석)

  • 박해식;조은일;박청길
    • Journal of Environmental Science International
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    • v.8 no.1
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    • pp.115-123
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    • 1999
  • Sewage has been almost treated by secondary treatment process. Secondary-treated effluent of sewage treatment plant caused the pollution of nearby beach. Nitrogen(N) and Phosphorus(P) in effluent water have caused many problems on estuary, such as red tide, eutrophication and aquatic toxicity. Therefore, the effective nitrogen and phosphorus removal from sewage treatment plants is necessary to prevent those pollution problems. However, little sewage treatment plant in Korea is effectively being operated for the removal of the nutrients. This study is analyzed for the effectiveness of cost when tertiary treatment process and Ocean Outfall are applied for the water quality of Suyong Bay After secondary treatment process, the effluent was discharged from the seabed in the depth of 32m of 4000m offshore. Pollutant concentration is decreased as much as the 180 times after the result of initial dilution, so that environmental protection requirement of Suyong Bay can satisfied. This Ocean Outfall process can save the 2.6~3.5 times as much as the cost of construction and operation for tertiary treatment process running over a 20 year.

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Initial Study on Behavior of Microorganisms in livestock Wastewater (축산폐수 미생물의 초기적 동정 연구)

  • 김태진;서종원;김진경;김종철;정태훈
    • KSBB Journal
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    • v.16 no.4
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    • pp.430-434
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    • 2001
  • Microorganisms of livestock wastewater were microscopically examined to identify bacillus types with optimal absorbance at 630 nm. Growth cuties of microorganisms at various levels of livestock wastewater (5, 10, 20, 30, 40, 50%) and different temperatures (20$\^{C}$ , 37$\^{C}$) were prepared to determine dilution at which microorganisms did not grow within 1 hour of inoculation, regardless of levels and temperatures. Heat treatment of livestock wastewater at 10 0$\^{C}$ for 2 minutes was good enough to inhibit the growth of microorganisms at 20$\^{C}$ and 37$\^{C}$. A good linear relationship was obtained between levels of livestock wastewater and absorbance at 630 nm (R=98.88%) and dry cell weight (98.98%). The dry cell weight of microorganisms in livestock wastewater was 0.375 g/L.

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Antigen Excess in Free Light Chain Assay U sing the Hitachi 7600 P-module Automatic Chemistry Analyzer (Hitachi 7600 p-모듈을 이용한 유리형경쇄 정량검사의 항원과잉역 반응)

  • Cha, Kyong-Ho;Kim, Sung-Hee;Song, Chang-Un;Sim, Yang-Bo;Chae, Hyo-Jin
    • Korean Journal of Clinical Laboratory Science
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    • v.41 no.4
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    • pp.173-179
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    • 2009
  • The analysis of serum free light chains (sFLCs) can improve the diagnosis and monitoring of multiple myeloma and other plasma cell dyscrasias. As with other immunoassays, sFLCstests are subject to potential antigen excess and heterophilic antibody interference. We describe 9 cases of sFLCs antigen excess in patients with multiple myeloma using the FreeliteTM Human Kappa and Lambda Free Kits (The Binding Site ltd., Birmingham, UK) and the Hitachi7600 P module turbidimetric system. A total of 1,247 consecutive samples from 250 patients with multiple myeloma were assayed for sFLCs from April to September, 2009. The samples were assayed using an initial dilution of 1 :5and subsequent dilutions of 1 :50 and 1: 100. The same samples were analyzed for the presence of monoclonal gammopathies using serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). There were 9 samples (0.72%) of antigen excess with 3 cases of kappa (0.24%) and 6 cases of lambda (0.48%). These cases represents an example of antigen excess or "hook effect" using the serum free light chain assays and mandates high level of attention to falsely low sFLC levels due to antigen excess, especially when it is disaccordant to other assay results or clinical manifestations.

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Dissipation pattern of pesticide residues in/on different varieties of lettuce applied with foliar spraying under greenhouse condition (시설재배에서의 상추품종별 살포농약의 소실양상)

  • Lee, Hee-Dong;Ihm, Yang-Bin;Kwon, Hye-Young;Kim, Jin-Bae;Kyung, Kee-Sung;Kim, Chan-Sub;Oh, Byung-Youl;Im, Geon-Jae;Kim, Jang-Eok
    • The Korean Journal of Pesticide Science
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    • v.9 no.4
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    • pp.354-358
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    • 2005
  • The study was carried out to investigate dissipation pattern of pesticide residue in/on different varieties of lettuce applied with foliar spraying under greenhouse. The initial deposited amount of alpha-cypermethrin and imidacloprid in/on the crop was entirely corresponded with shape of the crop. Dissipation of deposited pesticide residue was supposed to be related with degradation by sunlight and wash off by watering rather than dilution effect by biomass increase. The crop grouping in leaf vegetables has to be carefully considered even in lettuce for dissipation pattern of pesticide residue; head type and leafy type.

Effect of deep-sea mineral water on growth performance, water intake, blood characteristics and serum immunoglobulins in the growing-finishing pigs

  • Lee, Sang-Hee;Park, Choon-Keun
    • Journal of Animal Science and Technology
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    • v.63 no.5
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    • pp.998-1007
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    • 2021
  • Brine mineral water (BMW) is groundwater near the deep sea, and the mineral component of the BMW is different from the water of the deep sea because the components of BMW are derived from the unique geographical features surrounding it. Recently, BMW has attracted attention due to the unique health-related minerals it possesses; however, the influence of BMW on physiological function has not yet been determined in domestic animals. Therefore, this experiment investigated the influence of BMW on the growth performance, water intake, blood properties, and immunoglobulin (Ig) levels of serum in growing-finishing pigs. A total of 64 pig barrows (Landrace × Yorkshire × Duroc) with an average initial weight of 40.56 ± 0.17 kg were used in the experiment, and 0%, 2%, 3%, and 5% samples of BMW diluted with freshwater were provided to experimental animals during the 56 days. We found that the gain/feed ratio in the 3% BMW group was significantly higher than that in the 5% BMW group of growing-finishing pigs (p < 0.05). The water intake was significantly increased in the 5% BMW group compared with the other groups (p < 0.05) of growing-finishing pigs. Additionally, the concentrations of red blood cells (RBCs), hemoglobin (HGB), and hematocrit (HCT) were significantly higher in the 3% BMW group than in the control group. The level of high-density lipoprotein cholesterol was higher in the 3% BMW group than in the 5% BMW group (p < 0.05). Furthermore, IgG and IgM levels in the serum were significantly higher in the 2% and 3% BMW groups than in the control group (p < 0.05). These results suggest that a dilution of 3% BMW in the intake water could improve the levels of RBCs and serum Igs in growing-finishing pigs.