• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.39-47
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• 2003

Cr thin films were deposited on photosensitive polyimide substrates by RF bias sputtering and DC sputtering and the interfaces between Cr thin film and polyimide were observed using TEM. When the polyimide surface was in-situ RF plasma cleaned at the RF power density of 0.13-2.12 $W/cm^2$, increasing of RF power density changed the morphology of polyimide surfaces from round dig to sharp shape, and surface roughness increased by anisotropic etching. The intermixed layer-like interfaces between Cr and polyimide were observed in the RF bias sputtered specimens. This interface seems to be formed due to the RF cleaning effect; the polyimide surface was RF plasma cleaned while RF power was increased to the setting point before Cr deposition.

• Fisheries and Aquatic Sciences
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• v.24 no.12
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• pp.437-445
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• 2021

Roughscale sole (Clidoderma asperrimum) is only wild caught because basic reproductive research on this species is lacking and gamete production in an artificial setting has not been successful. Exogenous hormone treatment has been used to induce gonadal maturation and final spermiation in wild-caught individuals. In this study, the effects of an exogenous hormone on spermiation in roughscale sole was investigated by implanting different concentrations of a salmon gonadotrophin-releasing hormone analog (sGnRH; 0, 25, 50, and 100 ㎍/kg body weight) into male fishes. The control group did not produce sperm after 21 days post-implantation, and the duration of spermiation was shorter compared to the other groups. The spermiation period and milt amount differed among the hormone-treated groups according to the hormone concentration used. Milt volumes in the groups treated with 25 and 100 ㎍/kg sGnRH increased compared to the control group, whereas exogenous hormone treatment had no effect on the movable sperm ratio. The spermatocrit was high at the beginning of spermiation in all groups and then tended to decrease gradually over time except in the experimental group treated with 100 ㎍/kg sGnRH. Plasma levels of testosterone, 11-ketotestosterone, 17α, 20β-dihydroxy-4-pregnen-3-one were not significantly affected by the sGnRH treatments. Our results demonstrate that it is possible to prolong the spermiation period and increase milt volume by treating male roughscale soles with an exogenous hormone. In addition, the artificial hormone treatment did not affect sperm motility.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.575-579
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• 2023

In this work, pure W and W-0.5wt%HfC alloy (WHC05) were fabricated by sintering and hot-rolling following the same processing route. After exposing to a high flux deuterium plasma irradiation with the D⁺ flux to three fluences of 6.00 × 10²⁴, 2.70 × 10²⁵ and 7.02 × 10²⁵ D/m², the evolution of surface morphology, deuterium retention and hardening behaviors in pure W and WHC05 has been studied. The SEM results show the formation of D blisters on the irradiated area, and with the increase of D implantation, the size of these blisters increases from 200 ~ 500 nm (2.70 × 10²⁵ D/m²) to 1 ~ 2 ㎛ (7.02 × 10²⁵ D/m²) in WHC05 and from 1 ~ 2 ㎛ (2.70 × 10²⁵ D/m²) to > 3 ㎛ (7.02 × 10²⁵ D/m²) in pure W, respectively. A higher D retention and obvious hardening are observed in pure W than that of the WHC05 alloy, indicating an improve radiation resistance in WHC05 compared to pure W.

• Tribology and Lubricants
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• v.20 no.5
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• pp.272-277
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• 2004

This study deals with the friction and wear characteristics of C-N coated spur gear. The PSII apparatus was built and a SCM415 test piece and test gear with steel substrate was treated with carbon nitrogen by this apparatus. The composition and structure of the surface layer were analyzed and compared with that of PVD coated TiN layer. It was found that both of friction coefficient of C-N coating and TiN coating decreased with increasing load, however, C-N coating showed relatively lower friction coefficient than that of TiN coating. We was investigated the effect of C-N coating on hardness, friction and wear. The TiN coated gear showed a more serious friction phenomena than that of C-N coated gear. It was considered that coating of TiN, which was conducted at a vacuum chamber at about 500$^{\circ}C$, results in a tempering of base material that causes microstructural change, which in turn resulted in decreasing of hardness. The C-N coated gear and pinion had higher wear resistance that of TiN coated gear and pinion. C-N coating significantly improved the friction and wear resistance of the gear.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.41-46
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• 2004

This study deals with the friction and wear characteristics of C-N coated spur gear. The PSII apparatus was built and a SCM415 test piece and test gear with steel substrate was treated with carbon nitrogen by this apparatus. The composition and structure of the surface layer were analyzed and compared with that of PVD coated TiN layer. It was found that both of friction coefficients of C-N coating and TiN coaling decreased with increasing load, however, C-N coating showed relatively lower friction coefficient than that of TiN coating. We was investigated the effect of C-N coating on hardness, friction and wear. The TiN coated gear showed more serious friction phenomena than that of C-N coated gear. It was considered that coating of TiN, which was conducted at a vacuum chamber at about $500^{\circ}C$ results in a tempering of base material that causes microstructure change, which in turn resulted in decreasing of hardness. The C-N coated gear and pinion had higher wear resistance that of TiN coated gear and pinion. C-N coating significantly improved the friction and wear resistance of the gear.

• Journal of Pharmaceutical Investigation
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• v.25 no.2
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• pp.117-123
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• 1995

For the effective administration of narcotic antagonist, the application of sustained release implantable systems with biodegradable polyphosphazene was examined. Using poly[(diethyl glutamate)-co-(ethyl glycinate) phosphazene], the implantable devices containing naloxone hydrochloride were prepared and in vivo implantation studies were carried out subcutaneously in rat and rabbit with this preparation for the biocompatibility and pharmacokinetics. The histological finding in rats at initial time period was the inflammation that occurred focally around the implants, but they were showed subsequent mild and limited chronic inflammations and the irreversible changes such as necrosis and degeneration of the muscle or connective tissues were not observed. Therefore the placebo and naloxone implants are considered to be biocompatible formulations histologically. In pharmacokinetic studies, the release of naloxone from the naloxone implants into blood plasma was maintained in 192 hours, but the initial burst effect was observed. If this problem was solved, the application for the narcotic antagonist sustained release systems can be expected.

• Archives of Pharmacal Research
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• v.12 no.4
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• pp.269-275
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• 1989

Early embryo development and implantation were arrested in ICR mice which were passively immunized with a mouse monoclonal progesterone amtibody given as a single intraperitoneal injection at 12 hrs or 60 hrs post coitum (p. c.). Unimplanted embryos were recovered from the reproductive tract of the antibody-treated mice and none of these progressed to the blastocyst stage. The most pronounced effect was an arrest of embryonic development at a stage prior to cavitation. The plasma progesterone concentration in the blood taken by carbiac puncture increased greatly after the treatment by virtue of high affinity binding by the antibody in circulation. The result showed that passive immunization against progesterone shortly after mating interfered with early hormone dependent steps which were essential for normal embryonic development.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.59-59
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• 1999

DLC(diamond-like carbon)필름은 다이아몬드와 유사한 강도, 낮은 마차계수, 높은 Optical band gap, NEA(negative electron affinity)등의 우수한 특성을 가지고 있어, 내마모 코팅이나 정보저장 매체의 윤활 코팅, FED(field emission display)의 전계방출소자등 다양한 분야에의 응용이 연구되고 있다. DLC 필름은 PECVD(plasma enhanced chemical vapor deposition), IBAD(ion beam assisted deposition), Laser ablation, Cathodic vacuum arc등의 process를 이용하여 증착되고 있다. 특히 이러한 필름의 물성은 입사되는 이온의 에너지에 의해 좌우되는데, Lifshitz 등의 연구에 의하여 hyperthermal species를 이용한 DLC 필름의 성장은 초기에 subsurface로의 shallow implantation이 일어난 후 높은 sp3 fraction을 갖는 필름이 연속적으로 성장한다는 subplantation model이 제시 되었다. 본 연구에서는 기판과 subplantation 영역이 이후 계속하여 증착되는 순수 DLC 필름의 특성 변호에 미치는 영향에 대하여 관심을 가지고 실험을 행하였다. 본 실험에서는 상기 제시되어 있는 방법보다도 더욱 정확하고도 독립적으로 탄소 음이온의 에너지와 flux를 조절할 수 있는 Cs+ ion beam sputtering system을 이용하여 탄소 음이온의 에너지를 40eV에서 200eV까지 변화시키며 필름을 증착하였다. Si(100) 웨이퍼를 기판으로 사용하였고 증착 압력은 5$\times$10-7torr 였으며 인위적인 기판의 가열은 하지 않았다. 또한 Ion beam deposited DLC film의 growth process를 연구하기 위하여 200eV의 탄소 음이온을 시간(증착두께)을 변수로 하여 증착하였고, 이 때에는 Kaufman type의 gas ion beam을 이용하여 500eV의 Ar+ ion으로 pre-sputering을 행하였다. 탄소 음이온의 에너지와 증착두께에 따라 증착된 film 내의 sp3/sp2 ratio 의 변화를 XPS plasmon loss 와 Raman spectra를 이용하여 분석하였다. 또한 증착두께에 따른 interlayer의 결합상태를 관찰하기 위하여 AES와 XPS 분석을 보조로 행하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.3
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• pp.208-212
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• 2008

This paper reports physical properties of in situ boron doped silicon films made from boron source gas and silane ($SiH_4$) gas in a conventional low-pressure chemical vapor deposition vertical furnace. If the p-type polysilicon is formed by boron implantation into undoped polysilicon, the plasma nitridation (PN) process is added on the oxide in order to suppress boron penetration that can be caused during the thermal treatments used in fabrication. In-situ boron doped polysilicon deposition can complete p-type polysilicon film with only one deposition process and need not the PN process, because there is not interdiffusion of dopant at the intermediate temperatures of the subsequent steps. Since in-situ boron doped polysilicon films have higher work function than that of n-type polysilicon and they are compatible with the underlying oxide, they may be promising materials for improving memory cell characteristics if we make its profit of these physical properties.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.81-86
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• 2017

The Somatic cell nuclear transfer (SCNT) method can be applied to various fields such as species conservation, regenerative medicine, farming industries and drug production. However, the efficiency using SCNT is very low for many reasons. One of the troubles of SCNT is that it is highly dependent on the researcher's competence. For that reason, four somatic cell nuclear injection methods were compared to evaluate the effect of hole-sealing process and existence of cytochalasin B (CB) on efficiency of murine SCNT protocol. As a results, the microinjection with the hole-sealing process, the oocyte plasma membrane is inhaled with injection pipette, in HCZB with CB was presented to be the most efficient for the reconstructed in SCNT process. In addition, we demonstrated that the oocytes manipulated in Hepes-CZB medium (HCZB) with CB does not affect the developmental rate and the morphology of the blastocyst during the pre-implantation stage. For this reason, we suggest the microinjection involving hole-sealing in HCZB with CB could improve SCNT process efficiency.