• Title/Summary/Keyword: harsh environment

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Characteristics Evaluation of Al2O3 ALD Thin Film Exposed to Constant Temperature and Humidity Environment (항온항습 환경에 노출된 Al2O3 ALD 박막의 특성 평가)

  • Kim, Hyeun Woo;Song, Tae Min;Lee, Hyeong Jun;Jeon, Yongmin;Kwon, Jeong Hyun
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.2
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    • pp.11-14
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    • 2022
  • In this work, we evaluated the Al2O3 film, which was deposited by atomic layer deposition, degraded by exposure to harsh environments. The Al2O3 films deposited by atomic layer deposition have long been used as a gas diffusion barrier that satisfies barrier requirements for device reliability. To investigate the barrier and mechanical performance of the Al2O3 film with increasing temperature and relative humidity, the properties of the degraded Al2O3 film exposed to the harsh environment were evaluated using electrical calcium test and tensile test. As a result, the water vapor transmission rate of Al2O3 films stored in harsh environments has fallen to a level that is difficult to utilize as a barrier film. Through water vapor transmission rate measurements, it can be seen that the water vapor transmission rate changes can be significant, and the environment-induced degradation is fatal to the Al2O3 thin films. In addition, the surface roughness and porosity of the degraded Al2O3 are significantly increased as the environment becomes severer. the degradation of elongation is caused by the stress concentration at valleys of rough surface and pores generated by the harsh environment. Becaused the harsh envronment-induced degradation convert amorphous Al2O3 to crystalline structure, these encapsulation properties of the Al2O3 film was easily degraded.

Building mix design and quality control measures to reduce the combined deterioration of plain concrete in harsh environments (혹독한 환경에서의 무근콘크리트 복합열화 저감을 위한 배합설계 및 품질관리 방안 구축)

  • Kim, Dae-Geon;Park, Chan-Kyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.85-86
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    • 2016
  • Recently damages caused by the additional costs and degradation in durability combined deterioration due to plain concrete deterioration has occurred. In particular, in the case of the finish that is not exposed to the outside air in the concrete to respond to the harsh environment (freeze-thawing, calcium laying, etc.), to establish a quality control way for the process and the concrete mix design for it.

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Development of Two-color Radiation Thermometer for Harsh Environments

  • Mohammed, Mohammed Ali Alshaikh;Kim, Ki-Seong
    • Journal of ILASS-Korea
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    • v.21 no.4
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    • pp.184-194
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    • 2016
  • Many industrial processes require reliable temperature measurements in harsh environments with high temperature, dust, humidity, and pressure. However, commercially-available conventional temperature measurement devices are not suitable for use in such conditions. This study thus proposes a reliable, durable two-color radiation thermometer (RT) for harsh environments that was developed by selecting the appropriate components, designing a suitable mechanical structure, and compensating environmental factors such as absorption by particles and gases. The two-color RT has a simple, compactly-designed probe with a well-structured data acquisition system combined with efficient LabVIEW-based code. As a result, the RT can measure the temperature in real time, ranging from 300 to $900^{\circ}C$ in extremely harsh environments, such as that above the burden zone of a blast furnace. The error in the temperature measurements taken with the proposed two-color RT compared to that obtained using K-type thermocouple readouts was within 6.1 to $1.4^{\circ}C$ at a temperature range from 200 to $700^{\circ}C$. The effects of absorption by gases including $CO_2$, CO and $H_2O$ and the scattering by fine particles were calculated to find the transmittance of the two wavelength bands of operation through the path between the measured burden surface and the two-color probe. This method is applied to determine the transmittance of the short and long wavelength bands to be 0.31 and 0.51, respectively. Accordingly, the signals that were measured were corrected, and the true burden surface temperature was calculated. The proposed two-color RT and the correction method can be applied to measure temperatures in harsh environments where light-absorbing gases and scattering particles exist and optical components can be contaminated.

Comparison of the Characteristics of Metal Membrane Pressure Sensors Depending on the Shape of the Piezoresistive Patterns (금속 멤브레인 압력 센서에서 압저항체 패턴 형태에 따른 특성 비교)

  • Jun Park;Chang-Kyu Kim
    • Journal of Sensor Science and Technology
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    • v.33 no.3
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    • pp.173-178
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    • 2024
  • Development of pressure sensors for harsh environments with high pressure, humidity, and temperature is essential for many applications in the aerospace, marine, and automobile industries. However, existing materials such as polymers, adhesives, and semiconductors are not suitable for these conditions and require materials that are less sensitive to the external environment. This study proposed a pressure sensor that could withstand harsh environments and had high durability and precision. The sensor comprised a piezoresistor pattern and an insulating film directly formed on a stainless-steel membrane. To achieve the highest sensitivity, a pattern design method was proposed that considered the stress distribution in a circular membrane using finite element analysis. The manufacturing process involved depositing and etching a dielectric insulating film and metal piezoresistive material, resulting in a device with high linearity and slight hysteresis in the range of a maximum of 40 atm. The simplicity and effectiveness of this sensor render it a promising candidate for various applications in extreme environments.

Fieldbus Communication Network Requirements for Application of Harsh Environments of Nuclear Power Plant (원전 극한 환경적용을 위한 필드버스 통신망 요건)

  • Cho, Jai-Wan;Lee, Joon-Koo;Hur, Seop;Koo, In-Soo;Hong, Seok-Boong
    • Journal of Information Technology Services
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    • v.8 no.2
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    • pp.147-156
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    • 2009
  • As the result of the rapid development of IT technology, an on-line diagnostic system using the field bus communication network coupled with a smart sensor module will be widely used at the nuclear power plant in the near future. The smart sensor system is very useful for the prompt understanding of abnormal state of the key equipments installed in the nuclear power plant. In this paper, it is assumed that a smart sensor system based on the fieldbus communication network for the surveillance and diagnostics of safety-critical equipments will be installed in the harsh-environment of the nuclear power plant. It means that the key components of fieldbus communication system including microprocessor, FPGA, and ASIC devices, are to be installed in the RPV (reactor pressure vessel) and the RCS (reactor coolant system) area, which is the area of a high dose-rate gamma irradiation fields. Gamma radiation constraints for the DBA (design basis accident) qualification of the RTD sensor installed in the harsh environment of nuclear power plant, are typically on the order of 4 kGy/h. In order to use a field bus communication network as an ad-hoc diagnostics sensor network in the vicinity of the RCS pump area of the nuclear power plant, the robust survivability of IT-based micro-electronic components in such intense gamma-radiation fields therefore should be verified. An intelligent CCD camera system, which are composed of advanced micro-electronics devices based on IT technology, have been gamma irradiated at the dose rate of about 4.2kGy/h during an hour UP to a total dose of 4kGy. The degradation performance of the gamma irradiated CCD camera system is explained.

Growing of polycrystalline 3C-SiC thin films for harsh environment MEMS applications. (극한 환경 MEMS용 다결정 3C-SiC 박막의 성장)

  • Kim, Kang-San;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.408-409
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    • 2006
  • The polycrystalline 3C-SiC thin films heteroepitaxially grown by LPCVD method using single precursor 1. 3-disilabutane at $850^{\circ}C$. The crystallinity of the 3C-SiC thin film. was analyzed by XPS. Residual strain was investigated by Raman scattering. The surface morphology and voids between SiC and $SiO_2$ were measured by SEM. The grown poly 3C-SiC thin film is very good crystalline quality, surface like mirror, and low defect and strain. Therefore, the polycrystalline 3C-SiC is suitable for harsh environment MEMS applications.

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Apparatus on Corrosion Protection and Marine Corrosion of Ship (선박의 해양 부식과 부식방지 장치)

  • Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
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    • v.44 no.3
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    • pp.105-116
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    • 2011
  • Ships and offshore structures are exposed to harsh marine environments, and maintenance and repair are becoming increasingly important to the industry and the economy. The major corrosion phenomenons of metals and alloys in marine environment are pitting corrosion, stress corrosion cracking, crevice corrosion, fatigue corrosion, cavitation-erosion and etc. due to the effect of chloride ions and is quite serious. Methods of protection against corrosion can generally be divided into two groups: anodic protection and cathodic protection. Anodic protection is limited to the passivity characteristics of a material in its environment, while cathodic protection can apply methods such as sacrificial anode cathodic protection and impressed current cathodic protection. Sacrificial anode methods using Al and Zn alloys are widely used for marine structures and vessels intended for use in seawater. Impressed current cathodic protection methods are also widely used in marine environments, but tend to generate problems related to hydrogen embrittlement caused by hydrogen gas generation. Therefore, it is important to the proper maintenance and operation of the various corrosion protection systems for ship in the harsh marine environment.

Fabrication of NO sensor integrated SiC micro heaters for harsh environments and its characteristics (SiC 마이크로 히터가 내장된 극한 환경용 NO 센서의 제작과 특성)

  • Kim, Kang-San;Chung, Gwiy-Sang
    • Journal of Sensor Science and Technology
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    • v.19 no.3
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    • pp.197-201
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    • 2010
  • This paper describes the fabrication and characteristics of a NO sensor using ZnO thin film integrated 3C-SiC micro heater based on polycrystalline 3C-SiC thin film of operation in harsh environments. The sensitivity, response time, and operating properties in high temperature and voltages of NO sensors based SiC MEMS are measured and analyzed. The sensitivity of device with pure ZnO thin film at the heater operating power of 13.5 mW ($300^{\circ}C$) is 0.875 in NO gas concentration of 0.046 ppm. In the case of Pt doping, the sensitivity of at power consumption of 5.9 mW ($250^{\circ}C$) was 1.92 at same gas flow rate. The ZnO with doped Pt was showed higher sensitivity, lower working temperature and faster adsorption characteristics to NO gas than pure ZnO thin film. The NO gas sensor integrated SiC micro heater is more strength than others in high voltage and temperature environments.

Innovative Methodology for Assembling Jack up Leg of 205m on ground of Ultra

  • Yang, Yeong-Tae;Sim, Song-Seop;Lee, Seung-Yeop;Hwang, Oe-Ju;Sin, Bong-Yeong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.10a
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    • pp.87-92
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    • 2003
  • Generally, in jack up rig design for harsh environment, its leg height is a major factor for achieving a sufficient serviceability & operability in terms of the worst environment and the workable depth. Due to difficulties in constructing such a high-slender leg, inaccessibility of yard fabrication equipment, etc. the construction of Jack up rig fur harsh deep sea has not been common. Method using heavy crawler crane, fabrication tower or extension by the floating crane vessel is still conventional construction but, considering high cost fur mobilizing heavy lift vessel (HLV) or additional marine work for implementing preload / full height test at sea, the ground-base construction is much advantageous. Air skidding method (ASM hereafter) is ground-based construction methodology, newly developed due to such requests. ASM could also be extended to similar engineering fields. This paper presents the operating sequence, design parameters and procedure which were verified through successful operation at the end of May 2002.

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