• Journal of The Korean Astronomical Society
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• v.31 no.1
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• pp.39-50
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• 1998

We present UBV CCD photometry of Be 2, previously unstudied open cluster. Our photometry covers a field of $3'.2\times3'.8$ of the sky centered on the cluster, which is slightly smaller than the cluster diameter estimated to be about 260'. We have determined the reddening, distance, age and metallicity of the cluster by fitting the Pad ova isochrones to the observed stellar distributions in color-magnitude diagram as well as main sequence fitting: $E(B-V)=0.8\pm0.05,\;(m-M)_o=13.6\pm0.1,\;log(t) =8.9\pm0.1$, and Z=0.008. The present photometry shows that Be 2 is a distant open cluster of intermediate age. that it is a distant intermediate-age open duster.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.33-38
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• 2002

This paper deals with pressure ripple attenuation far separated-type Hydrostatic Transmission (HST) consisting ova variable axial piston pump connected in an open loop to a fried displacement axial piston motor. Pressure ripples in HST is major source of vibration which can lead to fatigue failure of components and cause noise. In order to reduce the pressure ripple, an annular tube tripe hydraulic filter is proposed to attenuate pressure ripples with the high frequencies components to achieve better noise reduction in HST. The basic principle of a hydraulic filter is allied to propagation of pressure wave, reflection, absorption in cross section of discontinuity and resonance in the hydraulic pipeline. It is experimentally shown that the hydraulic filter attenuates about 30∼40dB of pressure ripple with high frequencies. These results will assist in modeling and design of noise reduction in hydraulic control systems, and provide a means of designing a quieter HST.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.2
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• pp.195-197
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• 1996

Peking duck embryos incubated for 82 hrs after oviposition, stage 18 to 20(Hamberger and Hamilton, 1951) were transferred into the recipient eggshells and further incubated at $38.0^{\circ}C$ RH(relative humidity) 60 to 70%, with rotation at an angle of $30^{\circ}$ and the frequency of 4 times an hour. The survival rate was 100, 98, 82, 82, 70, 46, 21 and 16%, after the incubation period of 4, 8, 12, 16, 20, 24, 28 and 29 days, respectively. The present result clearly shows that the ex ova culture is possible for the Peking duck just as in the cases of the chicken or the quail. This culture technique could be useful for experimental manipulation of the embryos.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.481-487
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• 2002

A selective enzyme-linked immunosorbent assay (ELISA) for the insecticide chlorpyrifos was developed. Four haptens for chlorpyrifos were synthesized and two of them were used as immunogens after coupling to keyhole limpet hemocyanin by two differe nt approaches. Rabbits were immunized with either of them and the sera were screened against 4 haptens coupled to ovalbumin (OVA). Using the sera of highest specificity, an antigencoated ELISA was developed, which shows an I50 of 160 ppb with a detection limit of 10 ppb. An antibody-coated ELISA was also developed, which shows an $I_{50}$ of 20 ppb with a detection limit of 0.1 ppb. The antibodies showed negligible cross-reactivity with other organophosphorus pesticides except for insecticides chlorpyrifos-methyl and bromophos-ethyl, which makes these assays suitable for the selective detection of chlorpyrifos.

• Korean Journal of Animal Reproduction
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• v.15 no.3
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• pp.225-231
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• 1991

These experiments were carried out ot detect autoantiboies to zona pellucida in sera from infertile women using indirect ELISA and IFA and to investigate their effect on in vitro fertilization of mouse ova. In inidirect ELISA test, 12 of 116(10.3%) serum samples form infertile women gave positive reaction whereas all of 16 samples from fertile women and men were negative. Furthermore, in indirect IFA test, 17 of 116 (14.7%) serum samples from infertile women gave positive fluorescence whereas all of control sera were negative fluorescence. The fertilization rates(15.9%) of mouse eggs treated with positive sera were significantly lower than those(51.9%＋71.2%) autoantibodies to zonapellucida are responsible for infertility in unexplained infertile women, presumably by perventing sperm attachment and penetration.

• Korean Journal of Veterinary Research
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• v.13 no.1
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• pp.1-4
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• 1973

This experiment was performed in order to investigate the effect of radioiodine upon the uterus and the ovary of guinea pigs. The animals were injected single dose of 4. 5 mCi of radioiodine per kg of body weight. They were sacrificed on various time intervals; 1, 7, 14, 28, 42 and 56 days after the injection. The results were as follows: 1. In the ovary, the follicle cells and the ova were degenerated with lapse of time after the injection. 2. In the uterus, hyperplasia of the lamina propria of the endometrium and atrophy of the myometrium were observed in accordance with time after the injection.

• Tribology and Lubricants
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• v.18 no.2
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• pp.99-104
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• 2002

The paper presents the unbalance response of a rotor-bearing system supported by an active control bearing. The proportional, derivative and integral controls are investigated fur the control algorithm of an active control bearing to suppress the unbalance response of a rotor-bearing system. Results of analytical investigations on the unbalance responses of a rotor supported by an active control bearing are presented for various control gains. It is found that the unbalance response of a rotor can be greatly suppressed by the proportional, derivative or integral control of the bearing. The proportional control is more effective than the derivative control at low rotational speed, and the derivative control is more effective than the proportional control at high rotational speed. In the case of the integral control of the bearing, the unbalance response ova rotor is increased as a general rule. However, the integral control of the bearing is extremely superior to proportional or derivative control at very low rotational speed.

• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.253-258
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• 1982

The frequent finding of soil contamination by dogs' feces are remarkable, and such soil contamination may be public health problem. Of 608 samples, 30(4.9%) were positive for nematode ova. Ten paint 3% of sail samples from parks and 7.9% from footpaths were found to contain nematode eggs. Of the helminth eggs detected, eggs of Toxocara spp. were the most commonly encountered, and mostly from the soil of footpaths. No eggs were recovered from the soil of school yards; the level of soil contamination was low in public play areas. Egg recovery rate of the soil to dogs' feces collected from footpaths was approximately 1:5. And the larvae demonstrated from the soil in the present study were nematode larvae, mainly recovered from parks.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.265-268
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• 2005

To study the effect of bifidobacteria on preventing allergy response, levels of IFN-$\gamma$, IgG2a, IL-4, and IgG1 were investigated in splenocytes isolated from ovalbumin (OVA)­sensitized allergic mice and BGN4-administered allergy­suppressed mice in the presence of various bifidobacterial strains. Most of the bifidobacteria, except 2A, increased production of Th I-associated immune markers, IFN -$\gamma$ and IgG2a. In addition, most of the bifidobacteria, except 2A and 19A, decreased production of IL-4, whereas the differences in the production of IgG1 were less pronounced. These results suggest that some strains of bifidobacteria may have the potential to prevent the occurrence of allergy by switching Th1/Th2-type antibodies and/or related cytokines.

• Fibers and Polymers
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• v.3 no.2
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• pp.60-67
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• 2002

In the present study, the fluorescence behavior ova phenylethynyl-terminated imide (LaRC PETI-5) resin, a bismaleimide (BMI) resin, and various LaRC PETI-5/BMI blends with different blend compositions has been characterized as a function of heat-treatment temperature, using a steady-state fluorescence technique with a front-face illumination method far solid-state films. It is observed that there are distinguishable changes in the spectral shape, size, and position of fluorescence with varying heat-treatment temperature in the pure and blend samples. The result is qualitatively explained in terms of charge transfer complex formation as well as microenvironmental change with local mobility and viscosity occurring in the LaRC PETI-5, BMI, and their blends during the cure process. The result also implies that a steady-state fluorescence technique may be a useful tool to understand the processing conditions of polyimides and their blends in the film form on the basis of their thermo-photophysical responses.