• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.244-244
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• 2009

Carbon nanotubes (CNTs) have excellent electrical, chemical stability, mechanical and thermal properties. In this paper, networks of Multi-walled carbon nanotube (MWCNT) materials were investigated as transparent electrode. Sensor films were fabricated by air spray method using the multi-walled CNTs solution on glass substrates. The film that was sprayed with the MWCNT dispersion for 60 sec, was 300nm thick. And the electric resistivity and the light transmittance rate are $2{\times}10^2{\Omega}cm$ and 60%, respectively.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 추계 학술대회 논문집
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• pp.252-253
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• 2005

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.964-965
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• 2005

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2009년도 학술논문요약집
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• pp.445-446
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• 2009

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.11-18
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• 2022

In this research, curium oxide (CmO₂) is studied as fuel for VVER-1200 reactor to get an attention to its energy value and possibilities. For this purpose, CmO₂ is used in fuel rods or integrated burnable absorber (IBA) rods with and without UO₂ and then compared with the conventional fuel assembly of VVER-1200 reactor. It is burned to 60 GWd/t by using SRAC-2006 code and JENDL-4.0 data library. From these studies, it is found that CmO₂ is competent like UO₂ as a fuel due to higher fission cross-section of ²⁴³Cm and ²⁴⁵Cm isotopes and neutron capture cross-section of ²⁴⁴Cm and ²⁴⁶Cm isotopes. As a result, when some or all of the UO₂ of fuel rods or IBA rods are replaced by CmO₂, we get a similar k-inf like the reference even with lower enrichment UO₂ fuels. These studies show that the use of CmO₂ as IBA rods is more effective than the fuel rods considering the initially loaded amount, power peaking factor (PPF), fuel temperature and void coefficient, and the quality of spent fuel. From a detailed study, 3% CmO₂ with inert material ZrO₂ in IBA rods are recommended for the VVER-1200 reactor assembly from the once through concept.

• Nuclear Engineering and Technology
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• 제39권5호
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• pp.673-682
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• 2007

The contents of transuranic elements in high-burnup spent fuel samples were determined. The activity amounts of $^{238}Pu,\;^{239}Pu,\;^{240}Pu,\;^{241}Am,\;^{244}Cm\;and\;^{242}Cm$ were measured by alpha spectrometry using $^{242}Pu\;and\;^{243}Am$ as tracers, respectively. A spike addition method for $^{237}Np$ was established by an alpha and gamma spectrometry using $^{239}Np$ as a spike after the optimum conditions for the measurements of $^{237}Np\;and\;^{239}Np$, respectively, were obtained. A separation system using anion exchange chromatography and diethylhexylphosphoric acid extraction chromatography was applied for the separation of these elements. This method was applied to high-burnup spent nuclear fuel samples $(40{\sim}60GWD/MTU)$. The contents of the transuranic elements were compared with those by ORIGEN-2 code. Measurements and the calculations of the contents of the plutonium isotopes $^{238}Pu,\;^{239}Pu\;and\;^{240}Pu$ agreed to within 10% on average. The contents of $^{237}Np$ agreed to within approximately 5% except for one instance of a calculation, while those of $^{241}Am,\;^{244}Cm\;and\;^{242}Cm$ showed higher values by approximately 19%, 35% and 14% on average, respectively, compared to the calculations according to the burnup.

• Archives of Plastic Surgery
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• 제39권3호
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• pp.244-248
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• 2012

Many types of upper lip reconstruction have been introduced to treat defects after a tumor excision or trauma. The authors treated two cases of upper lip defects. A 35-year-old woman presented with a squamous cell carcinoma of the left upper lip that had invaded the corner of the mouth. After resecting the tumor, the defect was $3.7{\times}3.5cm$ in size. A 52-year-old woman presented with a dog bite of the right upper lip. The defect measured $4.0{\times}2.2cm$ in size. The two cases were reconstructed by combined rotation and advancement of a cheek flap. This technique produced a good functional outcome that allowed for oral competence and created an opening of adequate size. A combination of rotation and an advancement flap can be used to treat upper lip defects in a single-stage procedure. This approach produces a good functional and cosmetic outcome.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3704-3710
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• 2021

The characteristics of the external radiation on the surface of the casks for spent nuclear fuel (SNF) storage by dry method are investigated for the case when the spatial distribution of SNF in the basket changes due to the destruction of the fuel rod claddings. The surface areas are determined, where the changes in fluxes of neutrons, produced by ²⁴⁴Cm actinide, and γ-quanta, produced by long-lived isotopes, are maximum in the result of the decrease in the height of the SNF area. Concrete (VSC-24) and metal (SC-21) casks are considered as examples. The procedure of periodic measurement of the dose rate of neutrons or γ-quanta at the specified points of the cask surface is proposed for identifying the fuel rod cladding destruction. Under normal operation, the decrease in the dose rate produced by neutrons as the function of SNF storage duration is determined by the half-life of ²⁴⁴Cm, and for γ-quanta - by the half-lives of long-lived SNF isotopes. Consequently, a stepwise change in the dose rate of neutrons or γ-quanta, detected by the measurements, as compared to the previous one, would indicate the destruction of the fuel rod claddings.

• 한국환경생태학회지
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• 제30권3호
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• pp.308-319
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• 2016

우포늪의 목포습지에서 수심에 따른 수생식물의 분포 특성을 밝히기 위한 연구가 수행되었다. 274개 지점에서의 수심 및 식물종 분포 현황에 대한 표본조사가 이루어졌다. 선행연구에서 이루어진바 없었던 목포에 대한 상세한 수심분포 지도가 만들어졌다. 평균 수심은 77cm(${\pm}29cm$), 최대 수심은 157cm로서 가장자리는 60cm이내이며, 중심부가 120-130cm 정도의 오목한 그릇 형태를 이루고 있는 것으로 나타났다. 본 연구를 통해 침수식물 6종(검정말, 나사말, 나자스말, 말즘, 붕어마름, 실말)과 부엽식물 3종(가시연꽃, 자라풀, 마름)의 서식이 확인 되었다. 이들 수생식물들의 분포는 통계적으로 유의한 차이(${\chi}^2=982.2$, df = 8, p< 0.01)를 보여 환경조건에 따라 식물종의 분포 양상이 다른 것으로 확인되었다. 마름이 244회 출현하여 가장 높은 빈도로 출현하는 것으로 나타났으며, 말즘과 함께 수심이 깊을수록 피도가 높아지는 분포 양상을 보였다. 가시연꽃, 자라풀, 검정말, 나자스말, 붕어마름 5종은 수심이 깊을수록 피도가 낮아지는 음의 상관관계를 나타내었다. 수심에 따른 수생식물의 분포는 근본적으로 각각의 식물종이 가지는 생태적 특성에 의한 것이지만, 목포습지의 환경 특성을 반영하고 있는 것으로 나타났다.

• Steel and Composite Structures
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• 제25권2호
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• pp.231-244
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• 2017

This paper presents the structural identification of an arch dam model for the damaged, repaired and strengthened conditions under different water levels. For this aim, an arch dam-reservoir-foundation model has been constructed. Ambient vibration tests have been performed on the damaged, repaired and strengthened dam models for the empty reservoir (0 cm), 10 cm, 20 cm, 30 cm, 40 cm, 50 cm and full reservoir (60 cm) water levels to illustrate the effects of water levels on the dynamics characteristics. Enhanced Frequency Domain Decomposition Method in the frequency domain has been used to extract the dynamic characteristics. The dynamic characteristics obtained from the damaged, repaired and strengthened dam models show that the natural frequencies and damping ratios are considerably affected from the varying water level. The maximum differences between the frequencies for the empty and full reservoir are obtained as 16%, 33%, and 25% for damaged, repaired and strengthened model respectively. Mode shapes obtained from the all models are not affected by the increasing water level. Also, after the repairing and strengthening implementations, the natural frequencies of the arch dam model increase significantly. After strengthening, between 46-92% and 43-62% recovery in the frequencies are calculated for empty and full reservoir respectively. Apparently, after strengthening implementation, the mode shapes obtained are more acceptable and distinctive compared to those for the damaged model.