• Title/Summary/Keyword: laboratory freezing system

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Effect of κ-Carrageenan on Sperm Quality in Cryopreservation of Canine Semen (개 정액의 냉동보존 시 κ-Carrageenan이 정자 성상에 미치는 영향)

  • Kim, Eun-Ji;Talha, Nabeel A.H.;Jeon, Yu-Byeol;Yu, Il-Jeoung
    • Journal of Animal Reproduction and Biotechnology
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    • v.34 no.1
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    • pp.57-63
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    • 2019
  • This study was conducted to find out the effect that ${\kappa}-Carrageenan$ has on the properties of dog sperm when it was added to the cryoprotectant. Extender basically was contained 1.21 g Trizma base, 0.67 g citric acid, 0.4 g glucose, 0.03 g penicillin G, 0.05 g streptomycin sulfate. Extender1 was added with 0.1%, 0.2%, 0.3%, and 0.5% carrageenan, while extender2 was supplemented with glycerol. After freezing-thawing, the motility, viability, acrosome integrity, apoptosis, and ROS (reactive oxygen specifications) of sperm were measured to analyze the effects of the supplementation of carrageenan. Total Motile (TM), Rapid Progressive Motile (RPM), Medium Progressive Motile (MPM), and Immotile were measured through the CASA system after thawing in 37 degree water. Extender with 0.2% ${\kappa}-carrageenan$ ($64.26{\pm}0.49$) was significantly higher than control ($40.24{\pm}8.27$) (p < 0.05). RPMs of extender with 0.1%, 0.2% ${\kappa}-carrageenan$ ($57.64{\pm}6.34$, $56.47{\pm}1.35$) were significantly higher than the other groups (p < 0.05). Acrosome integrity was measured by dyeing to PSA-FITC with an epifluorescence microscope. Normal acrosome ratio of extender with 0.5% ${\kappa}-carrageenan$ ($61{\pm}8.03$) was higher than the other groups (p < 0.05). Apoptosis was measured with a FACSCalibur flow cytometer using FITC (FITC Annexin V Apoptosis Detection Kit). Treated groups of ${\kappa}-carrageenan$ of 0.1% ($0.81{\pm}0.05$), 0.2% ($0.85{\pm}0.05$) were significantly higer (p < 0.05) than control. Modified SYBR/PI staining was used for determination of viability and DCF staining was used for evaluation of ROS. Viability and ROS were not significantly different from other groups. In conclusion, adding a certain concentration of carrageenan to the extender of cryopreservation, carrageenan contributes to the improvement of the sperm motility, acrosome integrity and prevention of apoptosis.

Characteristics of Rutting and Moisture Susceptibility of R-EPDM Modified Asphalt Mixtures (R-EPDM 개질아스팔트 혼합물의 소성변형 및 수분민감성 특성)

  • Jo, Young-Jin;Han, Joung-Min;Noh, Young-Jin;Choi, Se-Hyu
    • International Journal of Highway Engineering
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    • v.12 no.4
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    • pp.87-92
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    • 2010
  • This study evaluates the laboratory properties of asphalt binder and mixture modified with R-EPDM(Recycling Ethylene Propylene Dien Monometer), which consists of R-EPDM as a main ingredient that is an industrial by-product made by manufacturing waste EPDM below 50 mesh as an additive. Superpave system was used to determine the PG(Performane Grade) and evaluate the property of R-EPDM modified binder. OACs(Optimum Asphalt Contents) of R-EPDM modified asphalt mixtures were determined by Superpave mix design using gyratory compactor and wheel tracking test and moisture susceptibility test were carried out with R-EPDM modified asphalt mixtures at OACs. The results from these tests, rutting-resistance and freezing and thawing resistance by moisture susceptibility of R-EPDM modified asphalt mixtures were superior to one of general asphalt mixtures(AP-5).

Characteristics of Shear Strength and Elastic Waves in Artificially Frozen Specimens using Triaxial Compression Tests (삼축압축실험을 이용한 인공동결시료의 강도평가 및 탄성파 특성변화)

  • Kim, JongChan;Lee, Jong-Sub;Hong, Seung-Seo;Lee, Changho
    • The Journal of Engineering Geology
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    • v.24 no.1
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    • pp.111-122
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    • 2014
  • For accurate laboratory evaluations of soil deposits, it is essential that the samples are undisturbed. An artificial ground-freezing system is the one of the most effective methods for obtaining undisturbed samples from sand deposits. The objective of this study is to estimate the shear strengths and the characteristics of elastic waves of frozen-thawed and unfrozen specimens through the undrained triaxial compression test. For the experiments, Jumunjin standard sands are used to prepare frozen and unfrozen specimens with similar relative densities (60% and 80%). The water pluviation method is used to simulate the fully saturated condition under the groundwater table. When thawing the frozen specimens, the temperature is measured every minute. After the specimens are completely thawed, undrained triaxial compression tests are conducted using the same procedures as for the unfrozen specimens. During the triaxial tests (saturation, consolidation, and shear phase), compressional and shear waves are measured. The results show that the freeze-thaw process has minor effects on the peak deviatoric stress and shear strength values, and that the process does not affect the internal friction angle. The compressional wave velocity increases with increasing B-value to 1800 m/s in the saturation phase, but tends to remain constant in the process of consolidation and shearing. The shear wave velocity decreases with increasing B-value in the process of saturation, but changes velocity in accordance with the change in effective stress in the processes of consolidation and shearing. The compressional wave velocity has similar values regardless of the freeze-thaw process, but values of shear wave velocity are slighly lower in frozen-thawed specimens than in unfrozen specimens. This study is a preliminary experiment for estimating the shear strength and characteristics of elastic wave velocity in undisturbed frozen specimens that have been obtained using the artificial ground-freezing method.

Evaluation of Exposure Indicators for Plants by Silicon Tetrachloride Release (사염화규소 누출사고지점 주변 식물에 대한 노출지표 평가)

  • Park, Jae-Seon;Kim, Jee-Young;Kim, Myeong-Ock;Park, Hyun-Woo;Chung, Hyen-Mi;Choi, Jong-Woo
    • Korean Journal of Environmental Agriculture
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    • v.36 no.4
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    • pp.288-292
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    • 2017
  • BACKGROUND: Silicon tetrachloride reacts with moisture in the atmosphere to generate hydrogen chloride, which affects the environment. Since silicon tetrachloride and its by-products are dispersed in the atmosphere in a short time after the silicon tetrachloride release into the atmosphere, it is difficult to directly assess the extent of environmental impact. In the present study, the exposure test of silicon tetrachloride or hydrogen chloride was examined in order to establish the criterion of the range affected by the silicon tetrachloride release, and the actual crops in the area exposed to silicon tetrachloride leakage were analyzed. METHODS AND RESULTS: For the experiment of exposure to silicon tetrachloride or hydrogen chloride, the leaves of red-pepper and corn were used in glass sealed containers. In the actual accident area, 59 samples from 10 different kinds of crops were collected. The pretreatment of the sample was performed by freezing and grinding, and then extracted using distilled water. The pH and concentration of chloride ($Cl^-$) ion of the extracted solution were measured using pH meter and ion chromatograph, respectively. CONCLUSION: Exposure to silicon tetrachloride caused visible damage, increasing the concentration of chloride ion, and decreasing the pH as well as hydrochloric acid. In the actual crops of the affected area, the tendency was the same as the result of the laboratory test, and the range of influence could be estimated through the concentration of $Cl^-$ ion over 2,000 mg/kg, and the correlation evaluation between the concentration of $Cl^-$ and pH. Therefore, the concentration of $Cl^-$ ion and the correlation between $Cl^-$ and pH would be considered as the factors to estimate the influence range of silicon tetrachloride release.