• Title/Summary/Keyword: dilution effects

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Suppression of Eimeria tenella Sporulation by Disinfectants

  • You, Myung-Jo
    • Parasites, Hosts and Diseases
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    • v.52 no.4
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    • pp.435-438
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    • 2014
  • The disinfectant effects (DEs) of 10 types of chemicals, defined by their ability to destroy or inhibit oocysts and consequently prevent sporulation of Eimeria tenella field isolate, were evaluated in vitro. Correct species assignments and sample purities were confirmed by the singular internal transcribed spacer (ITS)-PCR analysis. A total of 18 treatments were performed, and the disinfection suppression levels were 75.9% for 39% benzene + 22% xylene (1:10 dilution), 85.5% for 30% cresol soup (1:1 dilution), and 91.7% for 99.9% acetic acid (1:2 dilution) group. The results indicate that acetic acid, cresol soup, and benzene+xylene are good candidates for suppression of E. tenella oocyst sporulation.

Laser cladding of Ni-base superalloy on low carbon steel (저탄소강에 대한 Ni기 초합금의 레이저 클래딩)

  • 이제훈;서무홍;김정오;한유희
    • Laser Solutions
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    • v.2 no.2
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    • pp.34-41
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    • 1999
  • A RS840 $CO_2$laser and a powder auto-feeding apparatus have been used to deposit single tracks of Ni-base superalloy on low carbon steel. In this paper, the effects of laser cladding parameters on clad geometry, dilution and microhardness are studied. As a results, the w/h ratio of the clad layer increases with decreasing powder feed rate and increasing laser scan speed. Increase of powder density and decrease of specific energy have little effect on dilution. It was found that the clad layer of the highest hardness has a structure in which fine and leaf like phases are dispersed in ${\gamma}$Ni matrix.

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A Study on Characteristics of Microcrystalline-silicon Films Fabricated by PECVD Method (플라즈마 화학증착법으로 제작한 미세결정질 실리콘 박막 특성에 관한 연구)

  • Lee, Ho-Nyeon;Lee, Jong-Ha;Lee, Byoung-Wook;Kim, Chang-Kyo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.9
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    • pp.848-852
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    • 2008
  • Characteristics of microcrystalline-silicon thin-films deposited by plasma-enhanced chemical-vapor deposition (PECVD) method were studied. There were optimum values of RF power density and $H_2$ dilution ratio $(H_2/(SiH_4+H_2))$; maximum grain size of about 35 nm was obtained at substrate temperature of 250 $^{\circ}C$ with RF power density of 1.1 W/$cm^2$ and $H_2$ dilution ratio of 0.91. Larger grain was obtained with higher substrate temperature up to 350 $^{\circ}C$. Grain size dependence on RF power density and $H_2$ dilution ratio could be explained by etching effects of hydrogen ions and changes of species of reactive precursors on growing surface. Surface-mobility activation of reactive precursors by temperature could be a reason of grain-size dependence on the substrate temperature. Microcrystalline-silicon thin-films that could be used for flat-panel electronics such as active-matrix organic-light-emitting-diodes are expected to be fabricated successfully using these results.

Initial Protein Concentration and Residual Denaturant Concentration Strongly Affect the Batch Refolding of Hen Egg White Lysozyme

  • Guise, Andrew D.;Chaudhuri, Julian B.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.6
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    • pp.410-418
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    • 2001
  • The effects of several variables on the refolding of hen egg white lysozyme have been studied, Lysozyme was denatured in both urea, and guanidine hydrochloride(GuHCl), and batch refolded by dilution (100 to 1000 fold) into 0.1 M Tris-HCI, pH 8.2 mM EDTA 3 mM reduced glutathione and 0.3 mM oxidised glutathions. Refolding was found to be sensitive to temperature, with the highest refolding yield obtained at 50$\^{C}$. The apparent activation energy for lysozyme re-folding wasf ound to be 56kJ/mol, Refolding by dilution results in low concentrations of both de-naturant and reducing agent species. It was found that the residual concentrations obtained dur-ing dilution(100-fold dilution:[GuHCI]=0.06 mM, [DTT]=0.15 mM) were significant and could inhibit lysozyme refolding. This study has also shown that the initial protein concentration (1-10mg/mL) that is refolded is an important parameter. In the presence of residual GuHCl and DTT higher refolding yields were obtained when starting from higher initial lysozyme concentra-tions. This trend was reversed when residual denaturant components were removed from the re-folding buffer.

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Studies on the Rapid Freezing of Mouse Embryo I. Effects of Cryoprotectants Concentration on the Mouse Embryo Survival of the Rapid Freezing (Mouse 수정란의 급속보존에 관한 연구 제1보 내동제 농도가 Mouse 수정란 급속동결시 생존율에 미치는 영향)

  • 강만종;김영훈;문성호;김종규
    • Korean Journal of Animal Reproduction
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    • v.13 no.3
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    • pp.134-140
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    • 1989
  • Studies were conducted to seek reasonable methods of rapid freezing of mouse embryos using liquid nitrogen. The effects of the cryoprotectants concentration and the substitution of raffinose to sucrose in freezing and dilution medium on mouse embryo survival rates were determined using the FDA-test. The summarized results are as follows : 1. When 0.3M of sucrose was added into the freezing and dilution medium, FDA scores of embryos were 1.48(1.5M), 3.81(3.0M) and 4.10(4.5M). Higher FDA scores of embryos were obtained in 3.0M and 4.5M glycerol concentrations (P<0.05). 2. With the addition of 0.3M raffinose to the freezing and dilution medium, FDA scores of embryos did not significantly differ between glycerol levels ; 3.97(1.5M), 4.11(3.0M) and 3.54(4.5M). Higher scores of embryos existed in 3.0M glycerol concentration. 3. Concentration of sucrose or raffinose in freezing and dilution medium affected FDA scores of embryos. When sucrose concerations of 0.3, 0.5 and 1.0M were added to the freezing medium, FDA scores of embryos were 3.12, 2.38 and 0, respectively. However, when the same concentrations of raffinose were added to freezing medium, the FDA scores were 4.21, 2.91 and 0. In both cases, better FDA scores of embryos were attained in 0.3M of sucrose or raffinose (P<0.01).

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Chemical effects of added $CO_{2}$ and $H_{2}O$ to major flame structures and NOx emission characteristics in $CH_4$/Air Counterflow Diffusion Flames (메탄-공기 대향류확산화염에서 $CO_2$$H_2O$의 첨가가 화염구조와 NOx배출특성에 미치는 화학적 영향)

  • Hwang, Dong-Jin;Park, Jeong;Lee, Kyung-Hwan;Keel, Sang-In
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.129-136
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    • 2003
  • Numerical study with momentum-balanced boundary conditions has been conducted to grasp chemical effects of added $CO_{2}$ and $H_{2}O$ to fuel- and oxidizer-sides on flame structure and NO emission behavior in $CH_{4}$/Air counterflow diffusion flames. The dilution with $H_{2}O$ results in significantly higher flame temperatures and NO emission, but dilution with $CO_{2}$ has much more chemical effects than that with $H_{2}O$. Maximum reaction rate of principal chain branching reaction due to chemical effects decreases with added $CO_{2}$. but increases with added $H_{2}O$. The NO emission behavior is closely related to the production rate of OH, CH and N. The OH radical production rate increases with added $H_{2}O$ but those of CH, N decrease. On the other hand the production rates of OR CH and N decrease with added $CO_{2}$. It is found that NO emission behavior is considerably affected by chemical effects of added $CO_{2}$ and $H_{2}O$.

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Studies on the Liquid and Freezing storage of Boar Semen III. Effects of Dilutor on Livability and Fertility of Liquid Semen and Effects of Dilution and Vessel on Livability of Frozen Semen (돈정액의 액상 및 동결보존에 관한 연구. III. 보존액이 액상정액의 정자생존성과 수태율에 미치는 영향과 희석방법과 용기가 동결정액의 생존성에 미치는 영향)

  • 임경순;정장용
    • Korean Journal of Animal Reproduction
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    • v.3 no.1
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    • pp.30-35
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    • 1979
  • A, B and C dilutors were used to make Ka (A plus B (1 : 1)) and Na (B plus C(1 : 1)) dilutors in this experiment. Three aliqots of semen were respectivly diluted 1 : 1 and 1 : 2 (semen: dilutor) with Ka, Na and C dilutors and stored at 5$^{\circ}C$ for 7 days in order to study their livability during storage. Fertility was checked for the diluted semen with Ka, Na and C dilutors. Whole semen and extended semen with Na dilutos with and without DMSO were cold shocked at various temperatures for 10 min. Effects of different 1st and 2nd dilution with A, B, C and Na dilutors and of vessels on freezability of spermatozoa were investigtigated. 1. Extended semen 1 : 2 with Na and C dilutors showed highest live sperm index during storage for 7 days at 5$^{\circ}C$. 2. The components of Na dilutor per 100$m\ell$ were skim milk 2.5g, trisaminomethane 0.54g, citric acid 0.265g, glucose 2.835g, fructose 1.5g, sodium lauryl sulfate, 0.08g, penicillin 0.06g, streptomycin 0.075g, and egg yolk 10$m\ell$. 3. Fertility of diluted semen was higher than that of whole semen. Ka dilutor showed higher fertility than Na and C dilutors, and there was no difference in the fertility between Na and C dilutors. 4. Na dilutor with DMSO showed slightly higher livability than Na dilutor without DMSO during storage for 7 days at 5$^{\circ}C$. 5. Cold shock at 1$0^{\circ}C$ for 10 min. decreased greatly the sperm livalility of whole semen but not of extended semen with Na dilutor. Addition of DMSO to Na dilutor has no effect in prevention of cold shock. 6. The extended semen with C. C dilutor (1st and 2nd dilution with C and C dilutor) showed higher post-thawing sperm livability than A.A and Na. B dilutors. Na. B dilution shwed higher post-thawing sperm livability than A.A dilution. There was no difference in the post-thawing livability between semen in 1$m\ell$ straw and 10$m\ell$ aluminium package.

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Study on Combustion Characteristics of H2/CO Synthetic Gas (H2/CO 합성가스의 연소 특성에 관한 연구)

  • Kim, Tae-Kwon;Park, Jeong;Cho, Han-Chang
    • Journal of Environmental Science International
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    • v.17 no.6
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    • pp.689-698
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    • 2008
  • Numerical study is conducted to predict effects of radiative heat loss and fuel composition in synthetic gas diffusion flame diluted with $CO_2$. The existing reaction models in synthetic gas flames diluted with $CO_2$ are evaluated. Numerical simulations with and without gas radiation, based on an optical thin model, are also performed to concrete impacts on effects of radiative heat loss in flame characteristics. Importantly contributing reaction steps to heat release rate are compared for synthetic gas flames with and without $CO_2$ dilution. It is also addressed that the composition of synthetic gas mixtures and their radiative heat losses through the addition of $CO_2$ modify the reaction pathways of oxidation diluted with $CO_2$.

Numerical Analysis for the Detailed Structure of Syngas Turbulent Nonpremixed Flames (석탄가스 난류비예혼합 화염장의 해석)

  • Lee, Jeong-Won;Kim, Chang-Hwan;Kim, Yong-Mo
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.775-778
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    • 2007
  • The present study numerically investigate the detailed structure of the syngas diffusion flames. In order to realistically represent the turbulence-chemistry interaction, the transient flamelet model has been applied to simulate the combustion processes and $NO_X$ formation in the syngas turbulent nonpremixed flames. The single mixture fraction formulation is extended to account for the effects of the secondary inlet mixture. Computations are the wide range of syngas compositions and oxidizer dilutions. Based on numerical results, the detailed discussion has been made for the effects of syngas composition and oxidizer dilution on the structure of the syngas-air and syngas-oxygen turbulent nonpremixed flames.

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Numerical Investigations on Laminar Flame Speed of Syngas Flames at IGCC Gas Turbine Condition (IGCC 가스터빈 운전조건에서의 석탄가스 층류화염속도에 대한 기초연구)

  • Lee, Jeong-Won;Oh, Kyung-Taek;Kim, Yong-Mo
    • Journal of the Korean Society of Combustion
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    • v.16 no.4
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    • pp.38-45
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    • 2011
  • Coal-derived syngas has been utilized by main fuel at IGCC power plant. Research efforts for investigating the characteristics of premixed and nonpremixed flames at gas-turbine condition have been conducted. The present study has been mainly motivated to evaluate the capability of the detailed chemical kinetics to predict the syngas laminar flame speed. Special emphasis is given to the effects of pressure, temperature, syngas composition, and dilution level on the characteristics of premixed and nonpremixed flames. The predicative capability of a number of detailed mechanism for laminar flame speed is compared to experimental data. From these results, detailed kinetics of Davis et al. and Li et al. have the best conformity with the experiments in the all the case of parametric studies.