• Clinical and Experimental Reproductive Medicine
• /
• v.18 no.1
• /
• pp.73-80
• /
• 1991

We compared fertilizing potential measurements by the zona-free hamster egg penetration assay with the in vitro fertilization and embryo transfer program was evaevulated for their ability to fertilize zona free hamster egg. Spermatozoa from 12 presumeably fertile donors and from the male partners of 56 infertile couples were evaluated for their ability to fertilizing potentials. Penertration rates of fertile donors were $36.2{\pm}27.7%$ ; Fertilization rates of infertile couples between with normal semen parameters and with abnormal semen parameters were $28.7{\pm}19.1$, $5.7{\pm}8.9%$, respectively. Sperm motility of couples with penetration rates between on 15-30% and on 30> were $54.1{\pm}4.6$, $55.5{\pm}8.3%$ respectively. Hamster penetration rates of couples participating in an in vitro fertilization and embryo transfer program was $38.9{\pm}29.9%$. But in one case, a positive fertility assessment was obtained in the absence of fertilization of the wife's eggs attributable to egg immaturity. This method may have potential value as a diagnostic tool in evaluation human sperm fertilization capacity which avoids the ethical and logistical problems associated with fertilizing of human eggs in vitro.

• Korean Journal of Animal Reproduction
• /
• v.23 no.2
• /
• pp.149-157
• /
• 1999

The functional role of cumulus cells on the penetration and polyspermy during in vitro fertilization in porcine was examined. The penetration rate was significantly higher (P＜0.01) in oocytes with (61%) than without (25%) cumulus cells, but significant differences in polysper-my rates were not observed. When hyaluronidase was added to the fertilization medium with different concentrations, penetration rates in oocytes with cumulus cells were higher than in oocytes without cumulus cells at 0 (61% vs 34% ; P＜0.05), 0.01 (56% vs 35% ; P＜0.05), 0.1 (66% vs 30% ; P＜0.05) and 1.0mg/$m\ell$ (39% vs 27%). The polyspermy rates were lower in oocytes without than with cumulus cells, and had a tendency to decrease with high concentrations of hyaluronidase. In another experiment, the penetration and polyspermy rates had a tendency to increase as time of sperm-oocyte culture was prolonged. At 16 and 20 h after insemination, the penetration rates were significantly higher (P＜0.05) in oocytes with (48 and 62% for 16 and 20 h) than without (25 and 31% for 16 and 20 h) cumulus cells in medium containing hyaluronidase. Polyspermy rates were significantly (P＜0.05) lower in oocytes without (13% and 16%) than with (37% and 48%) cumulus cells at 16 and 20 h after insemination. In cumulus-free oocytes inseminated in medium containing different concentrations of cumulus cells, the penetration rates were significantly (P＜0.05) higher in medium with than without hyaluronidase. The proportion of polyspermy was lower in medium without than with hyaluronidase at 0 (10% vs 0%), 10$^2$(25% vs 0%), 10$^4$(24% vs 14%) and 10$^{6}$ (29% vs 10% ; P＜0.05) cumulus cells/$m\ell$. These results suggest that cumulus cells can have a positive influence on sperm penetration, its action on polyspermy control does appear to function primarily on zona pellucida by co-culture of cumulus cells and oocytes in medium without hyaluronidase.

• Korean Journal of Animal Reproduction
• /
• v.17 no.2
• /
• pp.127-132
• /
• 1993

Frozen semen obtained from 5 different Korean Native Cattle were used for in vitro fertilization of oocytes. The proportions(3∼11%) of oocytes penetrated in the basic medium with 13.9 mM glucose were very low in different semen. However, the penetration rates of oocytes in the presence of caffeine and heparin increased to 68∼84%. The proportions(10∼52%) of oocytes penetrated in the presence of caffeine alone were low at various glucose concentrations(0∼27.8 mM). In the medium with heparin, significantly(P<0.05 at least) higher penetration rate was obtained in the absence(94%) than in the presence(28∼45%) of 0∼27.8 mM glucose concentrations. The medium with caffeine and heparin, however, produced similar penetration rates(84∼97%) regardless of the various glucose concentrations.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.6
• /
• pp.16-22
• /
• 2004

Dimethyl Ether (DME) has been considered as one of the most attractive alternative fuels for a compression ignition engine. The major advantage of DME-fuelled engine is a great potential for soot-free combustion without sacrificing an inherent high thermal efficiency of diesel engine, despite a necessity for modification of the conventional fuel injection system. An experimental study on DME and conventional diesel sprays was conducted by employing a common-rail type fuel injection system with a 5-holes sac type nozzle, including a constant volume vessel pressurized with nitrogen gas. The injection rates of DME and diesel fuel were recorded with the Bosch type injection rate meter. The injection delay of DME was shorter than that of diesel fuel. The measured injection rates of DME and diesel fuel were correlated with spray penetrations. The prediction method of spray penetration was established using the injection rates, which was verified with the Dent's penetration model and found to agree well for DME case.

• Tunnel and Underground Space
• /
• v.22 no.2
• /
• pp.144-156
• /
• 2012

This paper discusses the methods of estimating the punch penetration indices and data analysis punch penetration test to estimate the TBM normal force and penetration rate. In punch penetration test is known as a useful test to estimate penetration rates and normal force of TBMs directly with several slope indices indicated drill-ability and brittleness of rocks. However, the standard methods and indices for punch penetration test are not suggested yet. The main purpose of punch penetration test which is prediction of normal force of TBM disc cutter when cutters excavate rock mass. In this study, the punch penetration tests were performed for 6 representative Korean rock types and variety length and diameter of rock core specimens. Among slope indices were obtained from punch penetration test, PLI and MLI which is suggested in this study show high correlation with cutter force measured by full-scale cutting test. The results show that the predicted normal force of a single disc cutter and the experimental error was 10%. Based on these results, it is concluded that punch penetration test is reliable laboratory test for estimating thrust and penetration rates of TBM.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.1
• /
• pp.55-62
• /
• 2010

Dynamic soil resistances were simulated by modified Ramberg-Osgood model in order to predict penetration rate of sheet pile installed by vibratory pile driver. Various factors which characterize modified Ramberg-Osgood model were determined considering the shapes of dynamic soil resistance curves obtained from field test and standard penetration value (N value) was used as parameter that relates field test results to the suggested model. Penetration rates calculated by analytical model were smaller than those of field test and penetration times were vice versa. Therefore, predicted penetration rate and penetration time by analytical model are more conservative than those of filed test.

• Computers and Concrete
• /
• v.22 no.2
• /
• pp.239-248
• /
• 2018

TBM penetration rate is a function of intact rock properties, rock mass conditions and TBM operational parameters. Machine rate of penetrationcan be predicted by knowledge of the ground conditions and its effects on machine performance. The variation of TBM operational parameters such as penetration rate and thrust plays an important role in its performance. This study presents the results of the analysis on the TBM penetration rates in schistose rock types present along the alignment of Golab tunnel based on the analysis of a TBM performance database established for every stroke through different schistose rock types. The results of the analysis are compared to the results of some empirical and theoretical predictive models such as NTH and QTBM. Additional analysis was performed to find the optimum thrust and revolution per minute values for different schistose rock types.

• Tunnel and Underground Space
• /
• v.17 no.3 s.68
• /
• pp.225-233
• /
• 2007

Because of Norwegian topography as valleys and fjords, a large number of tunnels has been built and 59 of them have been excavated by TBM for last 30 years. Prognosis technology has been developed and improved through lots of TBM experiences, and the NTNU prediction model has been completed. This paper focuses the improvement of net penetration rate and advance rate in 14 Norwegian and 4 Koran TBM tunnelling sites of which data were reported. Through this period, net penetration rate as well as advance rate were increased to double with the improvement of disc cutter size and cutter arrangement in Norway. These rates in Korea were also increased for 15 years even though the rates were lower compared to Norwegian. It is estimated that these low rates were mainly caused by using disc cutters less than 17 inch diameter. It is expected that net penetration rate and advance rate can be increased by improvement of machine and tunnelling technology, especially by using 17 or 19 inch of the disc cutter size in the Korean full face mechanical tunnelling site.

• Proceedings of the KSAR Conference
• /
• 2001.03a
• /
• pp.43-43
• /
• 2001

This study evaluated the effect of fertilization-promoting peptide (FPP) on fertilizing ability and glycosidase activity in vitro of spermatozoa frozen-thawed in pig, Using chlortetracycline fluorescence analysis, the various glycosidase analyses and the oocyte penetration test, we have obtained evidence that FPP can promote the fertilizing ability and glycosidase activity of frozen-thawed spermatozoa in vitro. When frozen-thawed spermatozoa was washed with different concentrations of FPP, there were significantly (P<0.05) more acrosome-reacted in medium with 100 nM than 0, 50, 200 and 400 nM. The penetration rates were also highest in medium containing with 100 nM FPP (P<0.05). On the other hand, the $\beta$-N-acetylglucosaminidase activity was at least twofold higher than other glycosidase. In same glycosidase, however, there were no difference in medium with different concentrations of FPP In another experiment, spermatozoa preincubated in medium with or without FPP for 0, 1, 2, 3 and 4 h were inseminated with oocytes matured in vitro. The percentages of spermatozoa that reached acrosome reaction were affected by preincubation and were higher in medium with that than without FPP. When oocytes were inseminated with spermatozoa preincubated in medium with and without FPP during the different periods, however, penetration rates were decreased with preincubation periods of spermatozoa. On the other hand, when the sperm-oocyte were cultured for 4, 8, 12, 16, 20 and 24 h, the penetration rates were higher in spermatozoa preincubated with that than without FPP and had a tendency to increase as time of culture periods. However, The activities of $\alpha$-fucosidase, $\alpha$ -mannosidase, $\beta$-galactosidase and N-acetyl- $\beta$-D-glucosaminidase were higher in medium with that than without FPP regardless of periods of sperm preincubation and sperm-oocyte culture. These results suggest that FPP may play a positive role in promoting of sperm function and glycosidase activity in vitro in pig.

• Toxicological Research
• /
• v.17 no.1
• /
• pp.7-9
• /
• 2001

The quantitative assessment of the penetration of organic solvents through skin is necessary for the evaluation of health hazards in occupational environments. We investigated the rate of dermal penetration when mixed or single forms of organic solvents were placed into a diffusion cell in vitro or into an experimental animal in vivo. The diffusion rates of methanol. toluene, and styrene were 6.07, 0.129, and 0.046 mg/$cm^2$/h, respectively. When skin was exposed to the mixed solvent of methanol and toluene, the penetration rate of toluene did not change significantly (0.110 mg/$cm^2$/h). However, the rate of methanol penetration increased to 43.90 mg/$\textrm{cm}^2$/h. The penetration rate of methanol also increased significantly to 54.69 mg/$cm^2$/h by mixing it with styrene. The concentration of methanol in the blood was monitored during the epicutaneous exposure in rats. The blood concentration of methanol was increased by mixing methanol with toluene as seen in the in vitro experiments. These results showed that the penetration rate of organic solvents would be enhanced by mixing them with other solvents.