• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.253-261
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• 2002

This study was carried out to investigate the semen characteristic, motility and viability and sperm motion characteristic by CASA test for establishing the Jindo-dog's semen freezing system. The results obtained are as follow: 1. The semen was collected 63 times. Average volume of semen, concentration of sperm, total number of sperm, progressive motility and viability were 3.8 $m\ell$ 145.6$\times$10$^{6}$ cells/$m\ell$, 396.2 x10$^{8}$ cells, 79.7% and 89.5%, respectively. Also, Fawn (Yellow) Jindo-dog comparing with White Jindo-dog showed better concentration of sperm, total number of sperm, progressive motility and viability. Among all dogs, the results of No. 2 Fawn Jindo-dog were the best. 2. The average progressive motility and viability of semen from 46 times were 73.5%, 82.3% before freezing and 51.1%, 64.9% after freezing. So, the freezing of semen has affected the progressive motility and viability. The progressive motility and viability of Fawn Jindo-dog's semen, before and after freezing, were better than White Jindo-dog. And No. 2 Fawn Jindo-dog showed the best results and showed significantly different among all dogs (P<0.05). 3. The 44 times-tested .esults by CASA system were as follow; MOT (motility) 65.6%. PROG (progressive motility) 54.8%, VAP (average path velocity) 75.3 ${\mu}{\textrm}{m}$/sec, VCL (curve linear velocity) 90.0 ${\mu}{\textrm}{m}$/sec, VSL (straight-line velocity) 69.4 ${\mu}{\textrm}{m}$/sec and ALH (amplitude of lateral head displacement) 4.4 ${\mu}{\textrm}{m}$. Although the motion characteristic of frozen semen were not significantly different between White and Fawn Jindo-dog, No. 2 Fawn Jindo-dog showed the best results and was significantly different among all dogs (P<0.05). 4. The success rate of frozen semen production between White and Fawn Jindo-dog were 43% (13/28), 94% (33/35), respectively, and the total success rate was 73% (46/63). The freezing-ability of Fawn Jindo-dog's semen was better than the other. Conclusively, the present results indicated that the characteristic and motility of Jindo-dog') semen were suitable for processing frozen semen, artificial insemination and mass production system. Also, the selection of suitable dog-breed was so important because the characteristic and freezing-ability of semen were significantly different between White and Fawn Jindo-dogs and among all individual dogs.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.117-133
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• 2010

A hybrid system of soil-nailing and compression anchor is proposed in this paper; the system is composed of an anchor bar (installed at the tip) with two PC strands and a steel bar. After drilling a hole, installing proposed hybrid systems, and filling the hole with grouting material, prestress is applied to the anchor bar to restrict the deformation at the head and/or to prevent shallow slope failures. However, since the elongation rate of PC strand is much larger than that of steel bar, yield at the steel bar will occur much earlier than at the PC strand. It means that the yield load of the hybrid system will be overestimated if we simply add yield loads of the two - anchor bar and PC strands. It might be needed to try to match the yielding time of the two materials by applying the prestress to the anchor bar. It means that the main purpose of applying prestress to the anchor bar should be two-fold: to restrict the deformation at the nail head; and more importantly, to maximize the design load of the hybrid system by utilizing load transfer mechanism that transfers the prestress applied at the tip to the head through anchor bar. In order to study the load transfer mechanism in a systematic way, in-situ pullout tests were performed with the following conditions: soil-nailing only; hybrid system with the variation of prestress stresses from 0 kN to 196 kN. It was found that the prestress applied to the anchor system will induce the compressive stress to the steel bar; it will result in decrease in the slope of load-displacement curve of the steel bar. Then, the elongation at which the steel bar will reach yield stress might become similar to that of PC strands. By taking advantage of prestress to match elongations at yield, the pullout design load of the hybrid system can be increased up to twice that of the soil-nailing system.