• Transactions of the Korean hydrogen and new energy society
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• v.19 no.3
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• pp.226-231
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• 2008

Cu/Fe/$Al_2O_3$ granules with various sizes have been prepared by a combination of sol-gel and oil drop method for the use in sulfur trioxide decomposition, a subcycle in thermochemical sulfur-iodine cycle to split water in the hydrogen and oxygen. The size of composite granules have been mainly changed by the flow-rate of the gel mixture before dropping in the synthesis. The structural properties of the samples were comparable with granule size. In the reaction, the catalytic activity was enhanced by decreasing size in the entire reaction temperature ranges.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.283-285
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• 2022

한의사의 복진을 모사하는 진단기기와 이를 이용하여 질환과 변증을 분류하는 알고리즘을 개발하는 연구가 진행되고 있다. 진행되는 연구에서 열화상에서의 복부 냉감 영역 검출 방법이 제시되었다. 이 연구에서 열화상을 획득하고, 한의사의 촉감 데이터를 획득하여 이를 비교하여, 딥러닝 알고리즘을 적용하여 열화상을 가지고 복부 냉감 영역을 찾는 방법을 제시하였다. 배경, 복부, 냉감 영역의 IOU 결과로 95.6%, 70.3%, 36%의 일치도를 보여주었다. 이는 신뢰성 있는 복진기기로 가는 필수적 경로이다.

• New & Renewable Energy
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• v.20 no.1
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• pp.110-115
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• 2024

Global sustainable energy needs and carbon neutrality goals make hydrogen a key future energy source. South Korea and Japan lead with proactive hydrogen policies, including South Korea's Hydrogen Law and Japan's strategy updates aiming for a hydrogen-centric society by 2050. A notable advance is the solar thermal chemical water-splitting cycle for green hydrogen production, spotlighted by Korea Institute of Energy Research (KIER) and Niigata University's joint initiative. This method uses solar energy to split water into hydrogen and oxygen, offering a carbon-neutral hydrogen production route. The study focuses on international collaboration in solar energy for thermochemical water-splitting and E-fuel production, highlighting breakthroughs in catalyst and reactor design to enhance solar thermal technology's commercial viability for sustainable fuel production. Collaborations, like ARENA in Australia, target global carbon emission reduction and energy system sustainability, contributing to a cleaner, sustainable energy future.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.3
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• pp.307-313
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• 2012

• Journal of Korean Association for Spatial Structures
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• v.11 no.1
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• pp.97-104
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• 2011

This paper contains of descriptions of deterioration diagnosis of the surface and a coating layer for maintenance managements of large spatial structures with membrane structure. Membrane is a roofing material of the structures that its performance of durability including its performance of chemical resistance and corrosive resistance is considered to be highly important. In general, the items of diagnosis for maintenance managements such as membrane extensively include the diagnosis of deterioration of the membrane surface, of a coating layer of membrane, the diagnosis of deterioration between a coating layer and fiber, of overall surface of membrane, of the class of ropes, of reinforced belts, and of the cover of rubber. The object of this study that needs maintenance managements of the membrane with PVC and FIFE which are commonly used and shows the diagnosis results of deterioration of the surface and a coating layer.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.5
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• pp.549-555
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• 2001

Ultrasonic is a powerful nondestructive technique for getting the information of flaws and material properties of in-services facilities. We prepared 4 different 1Cr-1Mo-0.25V specimens by Isothermal aging at $630^{\circ}C$. We evaluated material degradation using ultrasonic parameters, velocity, attenuation and harmonic generation. Attenuation and nonlinear parameter derived from harmonic generation efficiency increased as degradation. Especially the second harmonic of the fundamental wave in the 1,820h aging material was observed to exceed 20dB more than that in the un-aged material. But velocity remained virtually the same for all specimens. We concluded that nonlinear parameter and attenuation are sensitive to material degradation, but velocity was not. It'll be a good parameter for evaluating the material degradation.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.525-531
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• 2004

In this paper, the concept of infrared thermography(IRT), the principle of measurement of IRT and how to set up the IR camera for the nondestructive testing are described in detail. Also, its utilization and non-destructive testing(NDT) diagnosis are reviewed. By performing the periodic non-touched WDT through the estimation of thermal patterns related with the temperature for the surface targeted, IRT can be applied to the early prevention of the device failure. For the diagnosis utilization, thermal imaging patterns obtained from IRT for heated blocks with internal defects were estimated through the lion-destructive method and discussed the way of IRT estimation from the analysis of characteristics between material defects and thermal imaging patterns.

• Korean Journal of Materials Research
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• v.7 no.9
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• pp.717-722
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• 1997

노후화된 고온설비의 안정성 및 효율적인 운전조건을 확보하고, 고온부재의 취성파괴 방지를 위해서는 재질열화의 정량적 평가는 매우 중요하다. 그러나 현장실기에서 기계적 성질의 평가를 위한 대량의 시험편 채취는 거의 불가능하다. 따라서, 실기부재의 강도에 영향을 미치지 않는 범위에서 플랜트 구조물의 재질열화 평가를 비파괴적으로 검출 평가할 수 있는 새로운 시험방법들의 개발이 요구된다. 본 연구에서는 화력설비 부재의 다양한 탄소강을 대상으로 재질열화도 평가를 위한 전기화학적 양극분극시험법의 적용 가능성을 조사하였다. 또한 양극분극시험에 의한 재질열화평가 유효성을 조사하기 위해 전기화학적 시험결과를 입계부식시험결과와 비교.검토해 보았다.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.2
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• pp.132-138
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• 2008

금속산화물의 열화학싸이클에 의한 수소생산 소재중 안정성이 우수하고 물분해 수소생산능이 비교적 우수한 $NiFe_2O_4$를 합성하여 열화학수소생산공정 적용시 최적화의 조건에 대하여 검토하였다. 합성한 $NiFe_2O_4$는 격자상수가 $8.34\;{\AA}$이었고, 뫼스바우어에 의해 구조는 Ni이 페라이트 구조인 $AB_2O$의 B위치에 주로 위치하는, A 및 B의 상대적 흡수강도가 57.9:42.1인 역스피넬구조를 보이고 있다. 이러한 구조의 $NiFe_2O_4$의 열적환원은 $610^{\circ}C$부터 시작하여 $1200^{\circ}C$에 이르는 동안 약 1.1 wt%의 무게감소가 관찰된다. 물에 의한 산화과정에서 수소가 발생하게 되는데, $1200^{\circ}C$이하의 환원온도에서 가능한 수소생산량은 약 $0.45\;cm^3/g{\codt}cycle$ 이었다. 산화 환원의 반복과정에서 $NiFe_2O_4$의 XRD에 의한 구조변화는 관찰되지 않아 매우 안정한 구조를 갖는다는 것을 보여주었다. 수소생산을 위한 무게당 싸이클당 수소생산양은 산화 환원과정의 온도범위가 가장 중요하였고 물의 접촉시간은 중요한 요소가 되지 않았다. 열적 환원과정에서 많은 양의 수소생산성능을 보이기 위해서는 $1200^{\circ}C$이상의 고온을 필요로 하는 것을 보여주었다.

• Resources Recycling
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• v.31 no.2
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• pp.33-39
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• 2022

In this study, analytical thermochemical modeling factors that contribute to maintaining a specific temperature range during vanadium roasting as a pretreatment using a rotary kiln are investigated. The model-related mechanisms include thermochemical reaction rates, heat balance, and heat transfer, through which the resultant temperature can be estimated intuitively. Ultimately, by optimizing these parameters, the ideal roasting temperature in the kiln is ≈1000 ℃ (or ≈1273 K) for long-term operation. Therefore, the heat generated from hydrocarbon (natural gas) fuel combustion and ore oxidation reactions, as well as the radiant heat transferred to ores, are assessed. In addition, thermochemical methods for relieving the temperature gradient in order to maintain the optimum temperature range of the rotary kiln are suggested.