• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.163-163
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• 2000

In this research, we used the ion irradiation technique which has an advantae in improving intentionally the properties of surface and interface in a non-equilibrium, instead of the conventional annealing method which has been known to improve the material properties in the equilibrium stat. Cu/Co multilayered films were prepared on SiN4/SiO2/Si substrates by the electron-beam evaporation for the Co layers and the thermal evaporation for the Cu layers in a high vacuum. The ion irradiation with a 80keV Ar+ was carried out at various ion doses in a high vacuum. Hysteresis loops of the films were investigated by magneto-optical polar Kerr spectroscopy at various experimental conditions. The change of atomic structure of the films before and after the ion irradiation was studied by glancing angle x-ray diffraction, and the intermixing between Co and Cu sublayers was confirmed by Rutherford backscattering spectroscopy. The surface roughness and magneto-resistance were measured by atomic force microscopy and with a four-point probe system, respectively. During the magneto-resistance measurement, we changed temperature and the direction of magnetization. From the results of experiments, we found that the change at the interfaces of the Cu/Co multilayered film induced by ion irradiation cause the change of magnetic properties. According to the change in hysteresis loop, the surface inplane component of magnetic easy axis was isotropic before the ion irradiation, but became anisotropic upon irradiation. It was confirmed that this change influences the axial behavior of magneto-resistance. Especially, the magneto-resistance varied in accordance with an external magnetic field and the direction of current, which means that magneto-resistance also shows the uniaxial behavior.

• PNF and Movement
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• 제4권1호
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• pp.9-18
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• 2006

Purpose: The purpose of this study was to investigate the effect of Proprioceptive Neuromuscular Facilitation (PNF) applied to the unilateral upper extremity on the muscle activation of contralateral lower extremity. Twenty-two healthy subjects (mean age of 23.7 years) participated in this study. Method : PNF patterns applied on the unilateral upper extremity in all subjects were the flexion/abduction/external rotation and lifting pattern. The hold and appoximation techniques for the irradiation were applied to end range of both patterns. Muscle activations in four patterns were measured in vastus medialis, tibialis anterior, rectus femoris, and gastrocnemius medial muscles of contralateral lower extremity using surface EMG system. Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed by one factor analysis of variance with repeated measure test. Result : There were significant differences in the between-subject effect (muscles) and within-subject effect (patterns) in comparison of muscle activation by application of PNF patterns (p<.05). The irradiation led to higher activation in the flexion/abduction/external rotation pattern than that of lifting pattern in all muscles (p<.05). The approximation techniques revealed more activations than these of hold technique in all muscles (p<.05). Conclusion : These results suggest that the application of PNF patterns to the unilateral upper extremity affect on the muscle activation of contralateral lower extremity and increase according to the intensity of resistance. This mechanism of contralateral effect might provide a help to the development of treatment method for the affected side and functional improvement for the patients who have damages of central nervous system or musculoskeletal problems by orthopedic injury.

• 대한두경부종양학회지
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• 제19권1호
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• pp.47-51
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• 2003

본 증례에서 처럼 구강과 피부 또는 인두와 피부의 복합 결손은 내측 점막재건 및 피부의 외측부분을 함께 재건해야 하는데, 저자들이 사용한 진도서형의 양면 대흉근 피판이 아주 유용한 방법으로, 수술시간도 짧고 피판의 혈관경도 믿을 수 있어 대단히 안전한 피판으로 사료된다.

• 대한방사선치료학회지
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• 제14권1호
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• pp.175-186
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• 2002

The purpose of this study is directly measure and evaluate about absorbed dose change according to nominal energy and electron cone or medical accelerator on isodose curve, percentage depth dose, contaminated X-ray, inhomogeneous tissue, oblique surface and irradiation on intracavitary that electron beam with high energy distributed in tissue, and it settled standard data of hish energy electron beam treatment, and offer to exactly data for new dote distribution modeling study based on experimental resuls and theory. Electron beam with hish energy of $6{\sim}20$ MeV is used that generated from medical linear accelerator (Clinac 2100C/D, Varian) for the experiment, andwater phantom and Farmer chamber md Markus chamber und for absorbe d dose measurement of electron beam, and standard absorbed dose is calculated by standard measurements of International Atomic Energy Agency(IAEA) TRS 277. Dose analyzer (700i dose distribution analyzer, Wellhofer), film (X-OmatV, Kodak), external cone, intracavitary cone, cork, animal compact bone and air were used for don distribution measurement. As the results of absorbed dose ratio increased while irradiation field was increased, it appeared maximum at some irradiation field size and decreased though irradiation field size was more increased, and it decreased greatly while energy of electron beam was increased, and scattered dose on wall of electron cone was the cause. In percentage depth dose curve of electron beam, Effective depth dose(R80) for nominal energy of 6, 9, 12, 16 and 20 MeV are 1.85, 2.93, 4.07, 5.37 and 6.53 cm respectively, which seems to be one third of electron beam energy (MeV). Contaminated X-ray was generated from interaction between electron beam with high energy and material, and it was about $0.3{\sim}2.3\%$ of maximum dose and increased with increasing energy. Change of depth dose ratio of electron beam was compared with theory by Monte Carlo simulation, and calculation and measured value by Pencil beam model reciprocally, and percentage depth dose and measured value by Pencil beam were agreed almost, however, there were a little lack on build up area and error increased in pendulum and multi treatment since there was no contaminated X-ray part. Percentage depth dose calculated by Monte Carlo simulation appeared to be less from all part except maximum dose area from the curve. The change of percentage depth dose by inhomogeneous tissue, maximum range after penetration the 1 cm bone was moved 1 cm toward to surface then polystyrene phantom. In case of 1 cm and 2 cm cork, it was moved 0.5 cm and 1 cm toward to depth, respectively. In case of air, practical range was extended toward depth without energy loss. Irradiation on intracavitary is using straight and beveled type cones of 2.5, 3.0, 3.5 $cm{\phi}$, and maximum and effective $80\%$ dose depth increases while electron beam energy and size of electron cone increase. In case of contaminated X-ray, as the energy increase, straight type cones were more highly appeared then beveled type. The output factor of intracavitary small field electron cone was $15{\sim}86\%$ of standard external electron cone($15{\times}15cm^2$) and straight type was slightly higher then beveled type.

• Radiation Oncology Journal
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• 제6권2호
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• pp.289-293
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• 1988

방사선 치료는 악성 종양의 치료에서 국소 치료의 효과를 높이기 위한 수술 전후의 보조치료로서, 혹은 수술 불가능한 암, 잔여암, 또는 재발암의 치료로서 널리 사용되어 왔으며 외부 방사선 치료, 동위원소를 사용한 자입치료 등에 의한 장기간의 국소 치료효과 및 증상의 호전에 대한보고는 많다. 그러나 수술전후의 방사선 요법과 수술을 병행한 직장암 환자에서의 치료후의 재발은 외과적 치료가 대부분에서 불가능하여 외부 방사선 요법, 화학요법 등이 증상판화의 목적으로 사용되어 왔으나 강내 조사의 보고는 거의 없다. 영남대학교 치료방사선과에서는 수술전 경사에서 수술 불가능으로 판명되어 수술전 방사선 치료를 받은 후 개복 하였으나 절제가 불가능하였던 환자에서 발생한 누도(fistula tract)를 따라 재발된 직장암 환자에서 강내 치료를 실시하여 매우 빠른 증세의 호전을 경험하였기에 문헌 고찰과 함께 보고하는 바이다

• Journal of Electrochemical Science and Technology
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• 제13권3호
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• pp.390-397
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• 2022

The use of microwaves as the energy source for synthesis and sintering of ceramics offers substantial advantages compared to conventional gas-fired and electric resistance furnaces. Benefits include much shorter processing times and reaching the sintering temperature more quickly, resulting in superior final product quality. Most oxide ceramics poorly interact with microwave irradiation at low temperatures; thus, a more complex setup including a susceptor is needed, which makes the whole process very complicated. This investigation pursued a new approach, which enabled us to use microwave irradiation directly in poorly coupled oxides. In many solid-state electrochemical devices, the support is either metal or can be reduced to metal. Metal powders in the support can act as an internal susceptor and heat the entire cell. Then sufficient interaction of microwave irradiation and ceramic material can occur as the sample temperature increases. This microwave heating and exothermic reaction of oxidation of the support can sinter the ceramic very efficiently without any external susceptor. In this study, yttria stabilized zirconia (YSZ) and a Ni-YSZ cermet support were used as an example. The cermet was used as the support, and a YSZ electrolyte was coated and sintered directly using microwave irradiation without the use of any susceptor. The results were compared to a similar cell prepared using a conventional electric furnace. The leakage test and full cell power measurement results revealed a fully leak-free electrolyte. Scanning electron microscopy and density measurements show that microwave sintered samples have lower open porosity in the electrode support than conventional heat treatment. This technique offers an efficient way to directly use microwave irradiation to sinter thin film ceramics without a susceptor.

• Applied Microscopy
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• 제25권2호
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• pp.20-28
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• 1995

This study observes the change of small intestine mucosa paneth cell by changing the amount of radiation to rat. It uses the rat(Wistar) of 250-300g as the experimental animal and irradiation equipment is Gammacell 3000Elan System. and the irradiation is conducted for 500Rad group for 34sec., 1000rad for 68sec., and 1500Rad for 102sec. once on the whole body of each group, eachgroup is anesthetized with ether after 24hours. its small intestine is extrated and then it is observed by transmission electronic microscopy. The experimental results are as follows : 1. 500 Rad Group The Slightly elongated form of mitochondria and rough endoplasmic reticulum are observed in 500 Rad group. 2. 1000 Rad Group Golgi apparatus is appeared as the extended plasmodium, secretory granules exist only external membrane due to the self-fusion, the number of mitochondria that are changed as L-type are reduced, rough endoplasmic reticulum is distributed with the expanded form. 3. 1500 Rad Group The number of Golgi apparatus and granules is remarkably reduced, mitochondria is changed into C-type and free ribosomes can be observed instead of the reduction of rough endoplasmic reticulum.

• Macromolecular Research
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• 제17권4호
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• pp.271-275
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• 2009

This paper describes the out-of-plane order of a liquid crystalline(LC) methacrylate copolymer(3) comprised of a methacrylate(1) with a 4-styrylpyridine moiety as the photo-cyclodimerizable group and a benzoate moiety as the mesogenic group in the side chain, and another methacrylate(2) with a 4-(4-methoxyphenyl)benzoate moiety as the mesogenic group. The composition of 1 and 2 units in 3 was estimated to have a molar ratio of 54.2:45.8 by $^{1}H$ NMR spectroscopy. The X-ray diffraction study revealed that the copolymer forms a partial bilayer smectic structure. The copolymer gave rise to a high out-of-plane order parameter of about 0.74 in a wide LC temperature range of $110{\sim}160^{\circ}C$ after linearly polarized, UV light irradiation and subsequent annealing. Moreover, the external reflection IR analysis indicated that excess UV-light irradiation makes the out-of-plane LC structure of the copolymer appear in a higher and wider temperature range.

• Toxicological Research
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• 제17권2호
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• pp.97-106
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• 2001

Korean ginseng products have been fumigated with ethylene oxide (EO) for sterilization and prolongation of storage periods. However, there had been controversies indicating that the consumption of food treated with EO might cause harmful effects in human. Since, in Korea the use of EO gas for food treatment was banned in 1991. Since then, irradiation technique has been developed as an alternative. This study was carried out to investigate the effects of irradiated ginseng on fertility, and reproductive and developmental toxicity. Either EO gas fumigated or gamma-irradiated ginseng was administered to male rats by oral gavage for 63 days during the premating period. Female rats were administered from 14 days before mating to day 20 of gestation or to day 21 of lactation. The exposure amount of irradiation used was 5, 10 and 30 kGy, respectively. There were no treatment related changes of darns in clinical signs, and parturition. No treatment related changes in food consumption, body/organ weights, male/female reproductive and fertility performances were observed. F1 fetuses showed no external abnormality. Reflex/sensory junctions, physical/behavioral development, and reproductive performance of F1 rats were not adversary affected. The results of this study show that gamma-irradiated ginseng, up to 30 kGy, has no adverse effects on the fertility, reproduction and development in Wistar rats.

• Toxicological Research
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• 제17권1호
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• pp.27-32
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• 2001

Korean ginseng products have been fumigated with ethylene oxide (EO) for sterilization and prolongation of storage periods. However, there had been controversies indicating that consumption of EO treated foods might cause harmful effects in human. In Korea, the use EO gas for food treatment was banned in 1991. Since then, irradiation technique has been developed as an alternative. This study was carried out to evaluate the safety of irradiated ginseng on embryo and fetal developmental toxicity effects in rats. Either EO gas fumigated or $\gamma$-irradiated ginseng was administered to pregnant Wistar rats by oral gavage from gestational day 7 to 17. The amount of irradiation used in this study was 5, 10 and 30 kGy, respectively. There were no treatment related changes of dams in deaths, clinical signs, food consumption and body/organ weight. No treatment related changes in implantation ratio, litter size, sex ratio and body/organ weight of fetuses were observed. Also, no F1fetuses with external, visceral, head and skeletal mal-formation were observed. The results of this study showed that $\gamma$-irradiated ginseng, up to 30 kGy, has no adverse effects on fetal development of rats.