• 한국전산구조공학회논문집
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• 제17권4호
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• pp.405-412
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• 2004

재료나 핵연료조사시험에서 다공원통형구조물의 모든 구성품에서 감마열 및 fission과 같은 열원이 발생한다. 본 연구는 조사시험중 다공원통형구조물의 열적건전성을 평가하기 위해 온도분포에 대한 일반해를 구하는데 그 목적이 있다. 다공원통형 구조물의 온도해석을 위해 2차원 열전토 방정식을 이용하였다. 유한요소해석은 ANSYS 6.1을 이용하여 수행하였다. 다공원통형 구조물의 온도해석에서 이론해석결과와 유한요소해석결과는 홀의 개수가 3개 이하에서는 온도가 서로 잘 일치하는 것으로 나타났다. 구조물의 홀 개수가 4개일때, 온도분포해석에 대한 두 결과의 차이가 증가하였다.

• Corrosion Science and Technology
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• 제7권2호
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• pp.77-84
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• 2008

Based upon the good compatibility to neutron irradiation and high temperature water environment, austenitic stainless steels are widely used for core internal structural materials of light water reactors. But, recently, intergranular cracking was detected in the stainless steels for the core applications in some commercial PWR plants. Authors studied on the root cause of the intergranular cracking and developed the countermeasure including the alternative materials for these core applications. The intergranular cracking in these core applications are defined as an irradiation assisted mechanical cracking and irradiation assisted stress corrosion cracking. In this paper, the root cause of the intergranular cracking and its countermeasure are summarized and discussed.

• Korean Membrane Journal
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• 제7권1호
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• pp.19-27
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• 2005

PP hollow fiber membrane was hydrophilized by EVOH dip coating followed by low temperature plasma treatment and UV irradiation. EVOH coating attained high water flux without any prewetting but its stability did not guaranteed at high water permeation rate. At high water permeation rate, water flux declined gradually due to swelling and delamination of the EVOH coating layer causing pore blocking effect. However, plasma treatment reduces the swelling, which suppress delamination of the EVOH coating layer from PP support result in relieving the flux decline. Also, UV irradiation helped the crosslinking of the EVOH coating layer to enhance the performance at low water permeation rate. FT-IR and ESCA analyses reveal that EVOH dip coating performed homogeneously through not only membrane surface but also matrix. Thermogram of EVOH film modified plasma treatment and W irradiation show that crosslinking density of EVOH layer increased. Chemical modification by plasma treatment and UV irradiation stabilized the hydrophilic coating layer to increase the critical flux of the submerged membrane.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.23-28
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• 1997

Physicohemical properties of corn starches isolated from non-glutinous and corn grains fol-lowing γ-irradiation up to 10kGy were investigated. Blue value, water binding capacity and swelling power decreased, while alkali number ad solubility increased by γ-irradiation , which was more pronounced in glu-tinous corn starch than in non-glutinous corn starch. The optical transmittance increased with an increment of heating temperature and applied irradiation doses. No significant difference was observed in Hunter's color value between both starches isolated from non- irradiated and irradiated and irradiated corn grains. Amylograph viscosities decreased remarkably as dose levels increased. The overall effects of γ-irradiation was more distinguished in glutinous starch than in non-glutinous starch.

• 한국식품영양과학회지
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• 제27권1호
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• pp.63-68
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• 1998

Irradiation can be utilized to inhibit sprouting of onions and garlic. Thermoluminescence(TL) is a potential method to detect post-irradiation of onions and garlic because they are irradiated with soil or dusts on them, from which minerals can be isolated for TL analysis. This study was to determine whether TL can be applied for the detection of post-irradiation of onions and garlic. Onions and garlic produced in Korea were irradiated in the range of 0.01~0.6kGy. Minerals isolated from the samples using sodium polytrungstate solution were used for TL analysis. The onions and garlic irradiated at 0.15kGy or higher could be detected with little errors. Minimum dose for the 2nd glow could be applied since the dose for the 2nd glow did not affect the results. The TL intensities of the temperature ranges of 229~295$^{\circ}C$ and 229~361$^{\circ}C$ and the maximum intensity provided more accurate information for the determination of the post-irradiation of onions and garlic.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.220-220
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• 2009

In case of favourable irradiation conditions, the ratio of irradiation to the total irradiation went up and then the irradiation increased in the area with high angle of inclination. The study showed that on a clear day with the irradiation of more than $800[W/m^2]$, the pattern of alternating current power change in the fixed system was similar with that in the single-axis tracker. On the contrary, in case of unfavourable irradiation conditions, the ratio of diffuse irradiation to the total irradiation went up and then the horizontal irradiation increased. In the demo system, the fixed system, the single-axis tracker and the dual-axis tracker all had low generation power and similar generation pattern with each other. The study showed the generation power varied with the irradiation in the fixed system, while in the single-axis tracker and the dual-axis tracker, the amount of the generation power variation was much more than the irradiation variation. The demo system was operated from 11:00 AM to 2:00 PM for generating power, during which time, 46[%] to 56[%] of the total generation power was produced. In this study. the generation power was increased by 147[%] in the fixed system, by 136[%] in the single-axis tracker, and by 164[%] in the dual-axis tracker, and the pattern of generation power was similar with the generation power variation in the situation where the irradiation increased by 140[%] in the spring with plenty of insolation. The alternating current power was more sensitive to variation of the irradiation than to that of the surface temperature of a module. The variation of the irradiation had a more positive effect on the generation power than the type of array.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1213-1221
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• 2020

Chromium-nickel alloy 42XNM (XHM-1, Bochvalloy) is considered as a promising material for future generations of nuclear reactors, primarily as a material for the fuel elements shells in the development of accident tolerant fuel. However, as with most nickel-based alloys, 42ХNМ is characterized by a sharp decrease in plastic properties in the temperature range of (500-900)℃. This effect is enhanced by neutron irradiation. Preliminary tests of ring samples of 42XNM alloy (after irradiation as a part of the VVER-1000 control system) in the temperature range of ductility failure showed that the standard technique for processing tensile diagrams does not allow to evaluate the plastic properties correctly at low strains. Therefore, in this work, the alternative method for testing ring samples from materials with low plastic characteristics was developed. It was shown that the minimum value of the permanent strain of the irradiated 42XNM alloy in the temperature range of (500-1100)℃, determined by the alternative method, was ~1.6% at 750 ℃.

• 한국물환경학회지
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• 제30권5호
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• pp.486-490
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• 2014

Industrial use of microwave heating as an alternative to conventional heating is becoming popular mainly due to dramatic reductions in reaction time. Therefore, this work experimentally determined the effect of microwave irradiation on ammonia nitrogen removal in wastewater. The effects of air flow rate (0.3~0.9 L/min), treatment temperature ($70{\sim}100^{\circ}C$), and initial pH (9~11) were characterized. As the air flow rate increased from 0.3 to 0.9 L/min, the ammonia removal rate constant (k) increased from -0.6642 to $-1.0755min^{-1}$. As the temperature increased from 70 to $100^{\circ}C$, k increased -0.0338 to $-1.0755min^{-1}$. As the pH increased from 9 to 11, k increased -0.2443 to $-1.0755min^{-1}$. Ammonia removal was strongly dependent on temperature and pH rather than air flow rate. The results show that microwave irradiation is effective in ammonia nitrogen removal in wastewater due to advantages of fast and effective processing.

• 한국작물학회지
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• 제10권
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• pp.73-77
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• 1971

본 실험은 소맥품종 Weibull's Svenno종자(수분함량 11.3%)에 감마선과 속중성자를 조사한후 일정기간의 저장효과를 저장시 온도와 관련시켜 조사한 결과이다. 감마선이나 속중성자조사에 의하여 모두 묘생육은 저장기간의 연장에 따라서 감소되었고 선량구에서는 그 정도가 더욱 크게 나타났다. 저장온도효과에 대한 묘생육장해는 높은온도(4$0^{\circ}C$)구에서 크게 보였다. 이의 결과로서는 명확한 저장효과를 인정할 수 있었다.

• 한국식품영양과학회지
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• 제32권6호
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• pp.864-869
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• 2003

방사선 조사식품의 수용성 비타민에 대한 안정성을 확인하기 위하여 방사선 조사에 가장 민감하다고 알려져 있는 수용성 비타민 B$_1$과 비타민 C를 택해 닭 가슴살과 딸기와 감귤에 방사선을 조사한 후 닭 가슴살에서 비타민 B$_1$과 딸기와 감귤에서 비타민 C의 함량변화를 조사하였다. 닭가슴살 부위의 경우 감마선 조사시 온도를 냉장과 냉동 상태로 달리 하여 조사한 후 조리 방법을 가열조리와 마이크로웨이브 조리로 달리한 결과 티아민 함량의 손실은 감마선 조사선량에 따른 영향도 관찰되었지만 냉장, 냉동 등과 같은 조사시의 온도 상태도 크게 영향을 미치는 것으로 나타났다. 귤의 비타민 C 함량은 5 kGy까지는 조사에 의한 손실이 나타타지 않았고, 딸기의 비타민 C 함량은 3 kGy의 낮은 조사선량 범위 내에서는 조사선량에 의한 영향보다는 딸기의 품종에 따른 함량이 최종비타민 함량을 더 좌우하는 것으로 나타났다. 따라서 감마선 조사시 비타민의 함량의 변화에는 일정 범위의 조사선량하에서는 조사시의 온도나 식품의 조성 등이 더 큰 인자로 작용할 수 있으며, 가열에 의한 손실도 냉장보다는 냉동 처리 후 조사함에 의해 감소시킬 수 있는 가능성을 보였다.