• Korean Journal of Animal Reproduction
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• v.7 no.2
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• pp.57-71
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• 1983

1. Diluted chicken semen can be preserved at 2 to 5$^{\circ}C$ for 24 to 48 hr with resultant fertility of greater than 90% of that of fresh semen. Turkey semen can be preserved at 10 to 15$^{\circ}C$ for 6 to 24 hr and provide economical fertility. 2. Frozen chicken semen has given variable results; a 21 to 93% fertility ranges as compared to 92 to 94% expected with fresh semen. Highest fertility levels obtained with frozen turkey semen intravaginally inseminated have been 61 and 63% using DMSO and glycerol, respectively, as cryoprotectants. 3. The use of glycerol as a cryoprotectant reauires that its concentration in semen be reduced to less than 2% either by dialysis or centrifugation after thawing and before intravaginal insemination if optimal fertility is to be obtained. 4. The temperature at which cryoprotectants are added to semen and the time allowed for equilibration are important for subsequent fertility pre- and post-freezing. 5. The type of container used for packaging the semen, freeze or cooling rates, thaw rates and level of cryoprotectant all interact in affecting cell survival. 6. Plastic freeze straws as a packaging device for semen offers the following advantages: easy to handle, require minimal storage space, offer a wide range of freeze and thaw rates, and insemination can be made directly from them upon thawing. 7. Controlled slow cooling rates of 1 to 8$^{\circ}C$/min have thus far provided the best results for cooling chicken semen throught the transition phase change (liquid to solid) or critical temperature range of ＋5 to -20 or -35$^{\circ}C$. 8. Highest fertilities have been achieved with frozen chicken semen where a slow thaw rate (2。 to 5$^{\circ}C$) has been used regardless of the freeze rate. 9. To maintain a constant high level of fertility throughout a breeding season with frozen semen, a higher absolute number of spermatozoa must be inseminated (2 to 3 times as many) as compared to fresh semen since a, pp.oximately 50% are destroyed during processing and freezing. 10. The quality of semen may vary with season and age of the male. Such changes in sperm quality could be accentuated by storage effects. Thus, the correct number of spermatozoa may very well vary during the course of a breeding period. 11. As to time of insemination, it is best to avoid inseminating chicken hens within 1-2 hr after or 3-5 hr before oviposition; and turkey hens during or 7-10 hr before oviposition. 12. The physiological receptiveness of the oviduct at the time of insemination is a very important biological factor influencing fertility levels throughout the breeding season.

• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.25-32
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• 2020

The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.17-25
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• 2014

In the present study, it were performed an unconfined compression test and a field applicability test according to a mixed ratio of SS, soil type and curing period to analyze strength and deformation characteristic in order to evaluate engineering characteristics of soil mixed pavements using the eco-friendly soil stabilizer (SS). The test results revealed that SS mixed soil shows fast strength development at the initial curing time while 28-day strength amounted for 97% of the final strength. Furthermore, coarse-grained dredged sand (DS) and weathered granitic soil (WGS) have a larger ratio of deformation coefficient with respect to unconfined compressive strength than fine-grained dredged clay (DC) and organic soil (OS). Moreover, a comparison test between natural and forced drying conditions was conducted and test result showed 54% to 67% of strength degradation while having 55% to 63% of strength degradation in the freezing and thawing test result. Finally, a repeated loading test result showed that DS experiences up to 35% of strength reduction compared to initial strength under 10,000 times loading in maximum. Thus, it was validated that an appropriate amount of fine-grained sand is necessary to secure resistance capability to repeated loading.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.290-296
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• 2006

Crossbred pigs (female, 198 days old, $102{\sim}118kg$, Tamra Marketing Farm) were fed a diet supplemented with tangerine peel fer an extended period to study its effect on the physicochemical properties and palatability of the pork. The samples for this study consisted of the pork from pigs fed a diet without tangerine peel (T0), and the pork from pigs fed a diet containing 8% tangerine peel during the entire breeding period, from early pregnancy through the finishing period (T1). The pH Hunter's $L^*$ value, water holding capacity, freezing loss, thawing loss, cooking loss, hardness, springiness, cohesiveness, sensory raw meat color and cooked meat palatability of loin and belly were not significantly different between T0 and T1 pork (p>0.05). However, the Hunter's $a^*\;and\;b^*$ value, gumminess, shear force value (SFV) and smell were significantly higher in meat from loin of T1 than T0 pigs (p<0.05). Thus T1 pork exhibited an improved SFV, DPPH reduction and aroma of cooked belly meat (p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.766-772
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• 2009

In this study, the effects of feeding citrus byproduct on physicochemical and sensory characteristics of chicken meats were investigated. The samples consisted of chicken meats provided with only feed for laying hen without citrus byproduct (T-0), and the chicken meats fed with 1.0%, 1.5% and 2.0% citrus byproduct during the starter (initial period feed; $1{\sim}9th$ day), the grower (middle period feed; $10{\sim}24th$ day), and the finisher (latter period feed; $25{\sim}36th$ day), respectively. The $L^*$ value of thigh was significantly lower in the T-1 than in the T-0, the $a^*$ value was significantly higher in the T-1 than in the T-0 (p<0.05). The water holding capacity of thigh was significantly higher in the T-1 than in the T-0 and the cooking loss was significantly higher in the T-0 than in the T-1 (p<0.05). The acid value was significantly higher in the T-0 than in the T-1 (p<0.05). Antioxidant activity was higher in the T1 than in the T-0 (p<0.05). There was no significance between T-0 and T-1 regardless of feeding citrus byproduct, in terms of chicken's $b^*$ value, frozen loss, thawing loss, hardness, springiness, cohesiveness, gumminess, chewiness, shear force, free amino acid content of hot water extracts, taste, flavor, tenderness, juiciness and palatability.

• Journal of Environmental Impact Assessment
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• v.17 no.1
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• pp.1-9
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• 2008

Non-point pollution is caused by many diffusive sources, unlike a point pollution derived from industrial wastewater treatment plants or sewage treatment plants. Runoff of non-point pollutants is originated from rainfall or thawing in short period of time moving over and through the a ground surface. They cause ill effect on the quality of neighboring aquatic environment. To prevent effectively the wash off from non-point pollutant, it should be immediately reduced at the source or be treated after gathering of runoff water. This study has been carried out for the best width of riparian buffer zone. So we implemented the experiment in terms of its depth, width and kind of vegetations and calculated the reduction of pollutants loading. The experimental zone encompasses the watershed of Namhan River (Kyunggido Yangpyunggun Byungsanri). The region was divided into 5 land cover sectors : grass, reed, pussy willow, mixed(grass+pussy willow) and natural zone to compare effectiveness of vegetation. Water samples from four points have been collected in different depths. And the pollutant removal efficiency by sectors with different plant species was yielded through influent with one of each sample. And we obtained the correlation between the width of riparian buffer zone and the removal efficiency of pollutants. Using correlation result, the width of riparian buffer zones which needs to improve the water quality of river could be derived.

• Journal of Pharmaceutical Investigation
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• v.37 no.2
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• pp.79-84
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• 2007

This study was aimed to establish analytical method of Bi to develop a guideline of the bioequivalence test of tripotassium dicitrato bismuthate (TDB). For this purpose, a simple, specific and sensitive inductively coupled plasma-mass spectrometry (ICP/MS) method were developed and validated in human plasma. Various concentrations of bismuth standard solution (0-25ng/mL) were prepared with distilled water and human blank plasma. To 10mL of the volumetric flasks, 2mL of blank plasma was added with 8ml of distilled water. Bi standard solution was added to prepare the calibration samples and injected into ICP-MS. The plasma samples obtained from volunteers given 3 tablets of bismuth (total 900mg as TDB) were analyzed as described above. As a result, the coefficients of variation were <20% in quantitation limit (0.2 ng/mL) and <15% at the rest of concentrations. The stability test by repeated freezing-thawing cycles showed that the samples were stable only for 24hr. The stability tested for samples with a short-term period of storage at room temperature and pre-treatment prior to the analysis showed very stable over 24hr. In 8 healthy Korean subjects received Denol tablets at the dose of 900mg bismuth, AUC, $C_{max},\;T_{max}$ and half-life $(t_{1/2})$ were determined to be $198.33{\pm}173.78 ng{\cdot}hr/mL,\;64.48{\pm}27.06 ng/mL,\;0.52{\pm}0.21 hr,\;and\;5.15{\pm}2.67 hr$, respectively, from the plasma bismuth concentration-time curves. In conclusion, the method was suitable for the determination of bismuth in human plasma samples and could be applied to bioequivalence test of bismuth tablet.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.23-35
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• 2004

The weathering characteristics of periodically submerged sedimentary rocks in the Sayeon dam, Ulsan was examined by field work, electron probe micro-analysis, X-ray diffraction, and X-ray fluorescence spectrometry. Analysis of fracture zone and exfoliation showed the submerged sedimentary rocks have undergone severe mechanical weathering. Mechanical weathering in the water-rock interface accelerated chemical weathering, such as dissolution and alteration of the most of minerals except for quartz in the weathering zone. The dissolution of carbonates specially calcite, is remarkable creating the cavities, whereas formation of minerals including clay minerals is not active. The sedimentary rocks have been periodically submerged for a certain period of time, and have repeated freezing and thawing. This mechanical weathering favored infiltration, which accelerated mineral dissolution. The high content of easily soluble carbonate of the sedimentary rocks is likely the major cause of intense chemical weathering. The dissolved elements within the infiltrated water interrupted the occurrence of clay and weathering minerals, and expend fractures by infiltrated water accelerated weathering process.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.397-400
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• 2008

MgO powder-mixed concrete, expanded at the lower temperature around $850{\sim}1000$ degree celcius, might have long-term expansibility, which could remunerate for the contraction of concrete with delayed expansion, and through the process, the crack resistance of mass concrete might be improved. Currently used expandable concrete additive has three different types : CSA, CaO and MgO. In this study, therefore, such tests as carbonation, chloride diffusivity, freezing-thawing resistance and sulfate resistance after 56 days' curing were implemented and compared the results with the concrete with no MgO mixed to evaluate the durability of 5% MgO-mixed concrete after longer period of time. The degree of hydration for the MgO-mixed cement paste was analyzed after 1 day, 3 days, 7 days, 28 days, and 56 days using SEM, XRD, DSC.

• Journal of Aquaculture
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• v.11 no.1
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• pp.67-75
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• 1998

Experiments were performed to obtain cryopreservation techniques of black seabream (Acanthopagrus schlegeli) sperm. For sperm collection, brood stock reared in recirculating seawater system and fed with the commercial feed during experimental period. The results indicated that following cryopreservation method in block seabream sperm could be employed. Post-thaw survival rate of sperm revealed the highest value ($80{\pm}1.4$%) in 3% sodium citrate as a diluent for the cryopreservation. Cryopreserved sperm diluted with 5.4% glucose showed the highest fertilization rate to the ovulated eggs. Glycerol was a better cryoprotectant than dimethyl sulfoxide in sperm cryopreservation : survival rate and fertilizing capacity of cryopreserved sperm were decreased according to increase of glycerol concentration and varied in renges of 0.8~59.3% and 32.5~69.4% with 5~30% glycerol, respectively. A few of cryopreserved spermatozoa showed the enlarged head with granulated chromatin and ruptured plasma membrane by freezing and thawing injuries compared with unfrozen normal spermatozoa.