• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.40.1-40.1
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• 2011

TZM합금은 융점이 높은 Mo 기지에 미세한 (Zr,Ti)C의 석출물이 분산되어 있어 고온에서 다양한 부품에 응용가능하다. 하지만, TZM합금이 대기중 고온에 노출될 경우, 초기 산화물이며 약 $600^{\circ}C$부터 기화가 시작되는 $MoO_3$상이 형성됨으로써 물성에 치명적인 영향을 미친다. 이러한 산화거동을 막기 위하여 표면보호 코팅을 필요로 한다. 본 연구에서는 복잡한 형상과 대량생산이 가능하며 표면 코팅층과 모재의 접합성이 가장 강하다고 알려진 확산코팅법을 이용하여 Si을 TZM 합금에 코팅하였으며, 코팅층의 형성 속도론을 이해하기 위하여 온도별 및 시간별로 코팅을 수행하여 시간과 온도에 따른 코팅층의 형성 기구를 고찰하고자 하였다. Si의 확산코팅결과, $MoSi_2$층은 $1350^{\circ}C$에서 산화시에 두께가 감소하였으며, $Mo_5Si_3$상은 두께가 성장하였다. 코팅층의 확산거동을 속도론적 분석을 통하여 규명하고 논의하고자 한다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1163-1164
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• 2006

TZM alloy having elongated coarse-grain structure was developed by three-step internal nitriding treatment at 1423 to 1873 K in $N_2$ and subsequent recrystallization treatment at 2173 K in vacuum. Some specimens were subjected to re-nitriding treatment at 1873 K for 16 h. After the recrystallization treatment, aspect ratio (L/W) of grains for rolling direction was about 50 at the maximum. Yield stress obtained at 1773 K after re-nitriding treatment was about 6 times as large as that of recrystallized specimen. Re-nitriding was very effective in the improvement in strength of TZM alloy having elongated coarse-grain structure.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2005.11a
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• pp.38-39
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• 2005

• Journal of Veterinary Clinics
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• v.27 no.4
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• pp.330-335
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• 2010

This study was performed to compare the anesthetic and cardiorespiratory effects of the tiletamine/zolazepam/xylazine (TZX) combination and tiletamine/zolazepam/midazolam (TZM) combination. Eight healthy Landrace $\times$ Yorkshire pigs were randomly assigned to two groups. Each group was composed of four pigs. The pigs in group 1 (TZX) received tiletamine/zolazepam (2 mg/kg, IM) and xylazine (2 mg/kg, IM). The pigs in group 2 (TZM) received tiletamine/zolazepam (2 mg/kg, IM) and midazolam (0.5 mg/kg, IV). Induction time, anesthesia time and standing time were recorded for each pig. The scores of anesthetic effects were subjectively evaluated every 15 minutes during anesthesia. Cardiopulmonary parameters (heart rate, arterial blood pressure, respiratory rate and rectal temperature) were monitored and recorded 0, 5, 15, 30, 45 and 60 minutes after administration of drugs. Arterial blood gases ($pH_a$, $P_aCO_2$ and $P_aO_2$) and oxygen saturation ($SO_2$) were analyzed at same times. The scores of anesthetic effects decreased in the TZX group compare with the TZM group. From 5 to 85 minutes the mean heart rate in the TZX group was significantly lower than those in the TZM group. Mean arterial blood pressure in the TZX group was significantly higher than those in the TZM group at 5, 15 and 30 minutes. Both drug combinations provided a smooth induction and good immobilization. Scores of anesthetic effects in the TZM group were better than those in the TZX group. The effects to the cardiorespiratory function and temperature were lesser in the TZM group than those in the TZX group. In conclusion, when the two drug combinations were compared, the TZM group showed better anesthetic effects and less cardiorespiratory effects.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.421-427
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• 2013

There are many intramuscularly injectable drugs commonly used for anesthesia in dogs and combination of drugs were used for decrease the side effects. The objective of this study was to evaluate the anesthetic and cardiopulmonary effects of butorphanol-tiletamine-zolazepam-medetomidine and tramadol-tiletamine-zolazepam-medetomidine in dogs. Ten healthy beagle dogs (intact male; mean body weight : $9.5{\pm}1.60$ kg) were used in the study. Experimental animals were divided into two groups (n=5, each) and received 0.2 mg/kg of butorphanol (BZM) and 2 mg/kg of tramadol (TZM) according to the group after injection of $Zoletil^{(R)}$ (5 mg/kg) and medetomidine (10 ug/kg). All drugs were administered intramuscularly. Anesthesia and recovery, sedation and analgesia score, cardiovascular and respiratory parameters were measured. Induction and recovery time were not significantly different between the groups. Anesthesia time was $117.4{\pm}25.64$ minute and $81.2{\pm}12.50$ minute in BZM and TZM groups, respectively. Sedation and analgesia were satisfied in both groups. In both groups, common side effects related to the medetomidine, significant bradycardia and hypertension were not observed. There were no significant changes in respiratory data. In conclusion, tiletamine-zolazepam-medetomidine in combination with either butorphanol or tramadol can be suitable anesthetic protocol for minor procedures in dogs. They produced adequate anesthesia characterized by rapid induction, adequate analgesia and muscle relaxation without remarkable side effects.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.19-19
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• 2004

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.946-947
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• 2006

Driven by the unavailibility of commercial test equipment for tensile and creep testing at temperatures up to $3000^{\circ}C$ a measuring system has been developed and constructed at the University of Applied Sciences, Jena. These temperatures are reached with precision by heating samples directly by electric current. Contact-less strain measurements are carried out with image processing software utilizing a CCD camera system. This paper covers results of creep tests which have been conducted on TZM sheet material (thickness 2 mm) in different heat-treatment conditions in the temperature range between $1200^{\circ}C$ and $1600^{\circ}C$.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1161-1162
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• 2006

In order to overcome the recrystallization embrittlement and irradiation embrittlement of Mo, which are major problems for its fusion applications, internally nitrided Mo alloys were prepared by a novel multi-step internal nitriding. Neutron irradiation was performed in the Japan Material Testing Reactor (JMTR). After irradiation, nitrided Mo alloys exhibited $\iota$ ower ductile-brittle transition temperature than irradiated TZM. These results suggested that multi-step internal nitriding was effective to the improvement in the embrittlement by irradiation. Transmission electron microscope observation revealed that TiN particles precipitated by nitriding acted as a sink for irradiation-induced defects.

• Applied Science and Convergence Technology
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• v.24 no.5
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• pp.136-141
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• 2015

We studied the compact anode design to develop 100 kW rotating anode X-ray tube with large focal spot 1.2 mm, small focal spot 0.6 mm and tube voltage 150 kV for large hospital digital radiography using computer thermal simulation. The larger thermal radiation effect in a high vacuum can reduce the temperature of anode so the method to increase the surface area of anode is investigated. The anode has the multi-tier shape at the back side of TZM body of anode and also bigger diameter of anode. The number of multi-tiers was varied from 6 to 15 and the diameter of anode was also varied from ${\Phi}74$ to ${\Phi}82$. From ANSYS transient thermal simulation result, we could obtain $1056.4^{\circ}C$ anode maximum temperature when applying 100 kW input power at 0.1 second on target focal track which is less than $1091^{\circ}C$ of the conventional 75 kW X-ray tube with reduced anode weight by 15.5% than the conventional anode. The compact anode of reduced anode weight is able to improve the unwanted noise when the rotor is rotating at high-speed and also reduce the rotational torque which the cost effective stator-coil is possible. It is believed that the anode with 15 ea multi-tiers using ${\Phi}82$ can satisfy with the specification of the anode heat capacity. From the results of this paper, it has been confirmed that the proposed compact anode can be used as the anode of 100 kW rotating anode X-ray tube for digital radiography.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.191-199
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• 2004

This study was conducted to examine in vitro development of porcine embryos constructed by the microinjection of cultured fetal fibroblast cells into porcine oocytes matured in vitro. Single fetal donor cells were deposited into the perivitelline space of enucleated oocytes, followed by electrical fusion and activation. Activated embryos were cultured in NCSU-23 medium supplemented with 5％ FBS, at 38.5$^{\circ}C$ for 6 to 8 days in 5％ $CO_2$ and air. In experiment 1, fusion rates of nuclear transfer embryos did not differ for fetal fibroblast cells incubated in 5％ FBS + NCSU-23 or 5％ FBS + TL Heaps medium, nor did fusion rates of donor cells differ between 1-8 hr incubation durations. Fusion rates for the four treatment subclasses ranged from 72.1％ to 78.0％. In experiment 2, Pre-synchronization in medium containing 0.1 $\mu\textrm{g}$/m Hoechst 33342 an increase from 0 and 8 versus 15 h culture an increased percentage of porcine fibroblast cells in G2/M at the end of the synchronization period (12.4％, 17.5％ and 47.6％). Neither an increase in the concentration of H 33342 (0.2-1.6 $\mu\textrm{g}$/$m\ell$) nor a longer exposure time (12h, 18h and 24h) increased the proportion of porcine G2/M fibroblasts. In experiment 3, fusion rates did not differ significantly far nuclear transfer embryos constructed using donor cells cultured in 5％ FBS + NCSU-23 medium for 1-2, 6-8 or 12-14 days (60.0％, 73.3％ and 62.5％), respectively. The cleavage rate for nuclear transplant embryos using fetal fibroblast cells cultured for 1-2 days was 44.0％, significantly less than 56.7％ and 50.0％. for 6-8 or 12-14 days duration of culture, respectively. In experiment 4, the proportions of nuclear transfer embryos that developed to the $\geq$2 cell and to the blastocyst stage were not affected significantly by culture medium (5％ FBS + NCSU-23 or 5％ FBS + TL-Heaps) or by $O_2$ concentration of the culture (5％ vs 10％). Rates of development to the $\geq$2 cell stage ranged from 65.9％ to 70.1％, and development rates to the blastocyst stage ranged from 9.8％ to 12.5％ for the four treatment subclasses. Developmental rate was highest for embryos cultured in 5％ FBS + NCSU-23 under a gas atmosphere of 5％ $O_2$ in air.