• 대한방사선기술학회지:방사선기술과학
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• 제11권1호
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• pp.33-41
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• 1988

This study was measured the radiation-induced current - X-ray dose, dose rate, X-ray quality, time, temperature, electric field characteristics and the dependence of gap length in insulating oil under of D.C. Voltage before, during and after X-ray irradiation. The obtained results can be summarized as following. 1. The radiation - induced current is more the dependence of X-ray quality (tube voltage) than quantity (tube current), the dependence of quantity is appeared at the high than low X-.ay tube voltage. 2. The dependence of dose rate is appeared at the more dose rate, and ${\triangle}\;=\;0.64{\sim}0.74$. 3. The higher temperature of insulating oil and X-ray tube voltage (X-ray quality) is increased, at the low electric field, the more radiation-induced current. 4. $G_{eq}-G_{o}(={\triangle}G)$ is increased at the low than high temperature, high than low X-ray quality. 5. The dependence of temperature is appeared before than during X-ray irradiation. 6. The RIC saturation region is appeared at the high than low insulating oil temperature during (1000 V/cm above) than before (4000 V/cm above) X-ray irradiation.

• 한국진공학회지
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• 제3권2호
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• pp.147-157
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• 1994

Valence or core electron excitations induced by Synchrotron radiation (SR) irradiation and ensuing chemical reactions can be applied for semiconductor processes i, e, deposition etching and modifications of thin film materials. Unique selectivity can be achieved by this photochemical reactions in deposition and etching. Some materials can be ecvaporated by SR irradiation which can be utilized for low temperature surface cleaning of thin films. Also SR irradiation significantly lowers the reaction temperature and photon activated surface reactions can be utilized for direct writing or projection lithography of electronic materials. This technique is especially effective in making nanoscale feature size with abrupt and well defined interfaces for next generation electronic devices.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.685-687
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• 2024

Fiber optic cables are used extensively for remote monitoring in applications under extreme conditions, such as at high temperatures or in ionizing radiation fields. When high temperature fiber optic cables were subjected to gamma irradiations, there was a significant loss in transmission at wavelengths < 350 nm after only 1 minute of irradiation. Negligible recovery of the fiber optic transmission with time was observed over 2 years, but the irradiation damage was almost completely reversed by high temperature annealing at 400 ℃.

• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.166-171
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• 1997

The photomachinable glass-ceramics of Ag and CeO$_{2}$ added to Li$_{2}$O-Al$_{2}$O$_{3}$-SiO$_{2}$-K$_{2}$O glass system was investigated as a function of UV irradiation time. The temperature of optimum nucleation and crystal growth temperature were confirmed at 525.deg. C, 630.deg. C respectively using DTA and TMA. The phases of Li$_{2}$O.SiO$_{2}$ habit were lath-like and/or dendrite type and [002] direction of Li$_{2}$O.SiO$_{2}$ / Li$_{2}$O.2SiO$_{2}$ phases were changed according to the UV irradiation time by 400 W, 362 nm UV light source. Under that condition, the optimum UV irradiation time was 5 min.

• 폴리머
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• 제34권5호
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• pp.454-458
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• 2010

본 연구에서는 인공관절 베어링 부품으로 가장 널리 사용되는 초고분자량 폴리에틸렌(UHMWPE)을 대상으로 6가지 감마선 조사 방법에 따른 UHMWPE의 미세구조 변화를 비교 분석하였다. 감마선을 조사하지 않은 폴리에틸렌(UGI)과 비교하여, 기존의 멸균처리에 해당하는 공기 중 상온에서 감마선 조사한 폴리에틸렌(AR)의 결정화도와 가교 정도는 유의한 차이를 보이며 증가하였다. 감마선 조사 환경 중, 상온에서의 산소(AR)와 진공상태(VR) 영향을 비교하면, AR과 VR의 결정화도는 유의한 차이가 없었으며, VR의 가교정도는 유의한 차이를 보이며 증가하였다. 감마선 조사 환경 중, 진공상태에서의 상온(VR)과 극저온(V77) 영향을 비교하면, 결정화도와 가교정도 모두 유의한 차이가 없었다. 그러나, VR과 V77에서의 가교정도는 AR에서의 가교정도보다 유의한 차이를 보이며 증가하였다. 3가지 감마선 조사 환경에 대하여 감마선 조사 이후 열처리(/S) 영향을 비교하면, 결정화도는 AR/S와 VR/S에서 유의한 차이가 없었으나, V77/S에서는 유의한 차이를 보이며 감소하였다. 또한, 가교정도는 AR/S와 V77/S에서 유의한 차이를 보이며 증가하였으며, VR/S에서는 유의한 차이가 없었다.

• 한국초전도ㆍ저온공학회논문지
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• 제16권1호
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• pp.9-13
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• 2014

Effects of neutron irradiation on the superconducting properties of the undoped $MgB_2$ and the carbon(C)-doped $MgB_2$ bulk superconductors, prepared by an in situ reaction process using Mg and B powder, were investigated. The prepared $MgB_2$ samples were neutron-irradiated at the neutron fluence of $10^{16}-10^{18}n/cm^2$ in a Hanaro nuclear reactor of KAERI involving both fast and thermal neutron. The magnetic moment-temperature (M-T) and magnetization-magnetic field (M-H) curves before/after irradiation were obtained using magnetic property measurement system (MPMS). The superconducting critical temperature ($T_c$) and transition width were estimated from the M-T curves and critical current density ($J_c$) was estimated from the M-H curves using a Bean's critical model. The $T_cs$ of the undoped $MgB_2$ and C-doped $MgB_2$ before irradiation were 36.9-37.0 K and 36.6-36.8 K, respectively. The $T_cs$ decreased to 33.2 K and 31.6 K, respectively after irradiation at neutron fluence of $7.16{\times}10^{17}n/cm^2$, and decreased to 22.6 K and 24.0 K, respectively, at $3.13{\times}10^{18}n/cm^2$. The $J_c$ cross-over was observed at the high magnetic field of 5.2 T for the undoped $MgB_2$ irradiated at $7.16{\times}10^{17}n/cm^2$. The $T_c$ and $J_c$ variation after the neutron irradiation at various neutron fluences were explained in terms of the defect formation in the superconducting matrix by neutron irradiation.

• 한국의류산업학회지
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• 제14권3호
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• pp.478-485
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• 2012

The dying properties of fabrics with Chaenomelis Fructus extract were studied through an investigation of the characteristic of Chaenomelis Fructus colorants, the effect of dyeing conditions (dye temperature, dyeing concentration, and times on dye uptakes), effect of mordant, effect of UV irradiation, and color change in addition, antimicrobial ability and deodorant ability were estimated. In the UV-Visible spectrum, the wavelength of maximum absorption of Chaenomelis Fructus extract was 280 nm and showed that tannin is the major pigment component. From the increase of absorbance by UV irradiation, it was assumed that catechol tannin color was developed through UV irradiation. An increased dyeing concentration resulted in a larger dye uptake. Dye uptake increased as the dyeing time and temperature increased. Chaenomelis Fructus extract showed relatively good affinity to silk than cotton. Mordant, Fe and Cu were effective to increase the dye uptake of cotton fabric in addition, the dye uptake of silk fabric mordanted with Fe and K improved. UV irradiation let the color of dyed fabrics develop regardless of the UV irradiation stage however, UV irradiation on the dyed fabric was more effective than on the extract for the color development. Dyed silk fabric showed very good antimicrobial abilities of 99.9% in addition, deodorant ability improved in the fabric dyed with Chaenomelis Fructus extract.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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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.

• 한국포장학회지
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• 제27권2호
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• pp.85-90
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• 2021

The gamma irradiation was on to Poly(butylene sebacate-co-terephthalate) (PBSeT), Poly(butylene adipate-co-terephthalate) (PBAT), Poly(lactic acid) (PLA) and casting polypropylene (CPP) at dose levels from 0 to 50 kGy. The properties of gamma irradiated samples were analyzed using DSC, TGA, UTM and FT-IR spectra. The mechanical and thermal properties of PBSeT and PBAT after gamma irradiation were less affected than CPP. The tensile strength and elongation of PBSeT was not affected by gamma irradiation, while these of PBAT, PLA and CPP were significantly decreased at 50 kGy gamma-ray dose. The thermal stability of PBSeT, PBAT, PLA and CPP showed a similar tendency to tensile strength. The glass transition temperature(T_g) and melting temperature(T_m) of PBSeT and PBAT were not altered by increasing gamma-ray dose, while these of PLA and CPP decreased. The chemical composition of all samples was not modified by gamma irradiation, and it was confirmed by FT-IR spectra. Based on mechanical and thermal stability studies of gamma irradiation on bioplastics, tested biodegradable packaging materials showed a potential to be used in sterilization process up to 35 kGy.

• Nuclear Engineering and Technology
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• 제45권7호
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• pp.941-950
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• 2013

The Korean Nuclear-Hydrogen Technology Development (NHTD) Plan will be performing irradiation testing of coated particle fuel at HANARO to support the development of VHTR in Korea. This testing will be carried out to demonstrate and qualify TRISO-coated particle fuel for use in VHTR. The testing will be irradiated in an inert gas atmosphere without on-line temperature monitoring and control combined with on-line fission product monitoring of the sweep gas. The irradiation device contains two test rods, one has nine fuel compacts and the other five compacts and eight graphite specimens. Each compact contains about 260 TRISO-coated particles. The irradiation device is being loaded and irradiated into the OR5 hole of the in HANARO core from August 2013. The device will be operated for about 150 effective full-power days at a peak temperature of about $1030^{\circ}C$ in BOC (Beginning of Cycle) during irradiation testing. After a peak burn-up of about 4 atomic percentage and a peak fast neutron fluence of about $1.7{\times}10^{21}\;n/cm^2$, PIE (Post-Irradiation Examination) of the irradiated coated particle fuel will be performed at IMEF (Irradiated Material Examination Facility). This paper reviews the design of test rod and irradiation device for coated particle fuel, and discusses the technical results for irradiation testing at HANARO.