• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.1
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• pp.64-69
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• 2008

In order to detect the internal defects which occur in welding parts of pressure vessel and structures, radiographic testing and ultrasonic testing is applied. However, because of the risks of radiation exposure and film processing, radiographic testing takes a relatively long time to verify the test results and it has affected in the production process. Typically, the manual ultrasonic testing is not easy to reproduce the result and it is highly dependent on the tester's skills. The TOFD technique, one of the automatic ultrasonic testings is spreading alternatively. This research describes the comparing test results by applying radiographic testing and TOFD technique to a mock-up specimen incruding the flaws. The TOFD technique will contribute to improve the objective reliability of the ultrasonic technique.

• Textile Coloration and Finishing
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• v.19 no.6
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• pp.21-27
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• 2007

The factors which affect the absorption and diffusion of disperse dye in print paste for polyester film were investigated using film roll method. When Emvatex print paste of different disperse dye concentrations were fixed by high temperature steaming(HTS) for 2 hr at $190^{\circ}C$, the dye uptake and diffusion distance of 50g/kg dye concentration for PET film were very low, but those of 100$\sim$300g/kg were increased with increasing dye concentration. It was found that sodium alginate(5%) was more effective for the absorption and diffusion of disperse dye to PET film than CMC(3%) and Emvatex(18%), and Emvatex showed comparatively low absorption in three thickeners used. The dye uptake and diffusion distance of disperse dye in sodium alginate paste for PET film were increased with increasing paste thickness to $160\sim180{\mu}m$, but were decreased at $200\sim220{\mu}m$ in both fixations of baking and HTS for 2 hr at $190^{\circ}C$, and were far more largely increased by fixation of HTS than baking because steam was very important for fixation. Also it was confirmed that dye uptake was slightly increased as steam supply pressure was raised from 1 $kg/cm^2$ to 2 $kg/cm^2$, andthe dye uptake and diffusion distance of disperse dye were outstandingly increased with raising fixing temperature from $170^{\circ}C$ to $190^{\circ}C$ and fixing time from 0.5 hr to 3 hr in the fixation of HTS.

• Journal of Convergence for Information Technology
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• v.10 no.8
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• pp.137-143
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• 2020

This study examined the effects of rapid thermal annealing (RTA) on the physical and chemical characteristics of thin silver (Ag) layers on SiO2 coated metal foils. Ag layers were annealed at various temperatures of the range between 150 ℃ and 550 ℃ for 20 min. The surface roughness and resistivity are increased at the annealing temperatures of 550 ℃. We also found that oxygen (O) and silicon (Si) atoms exist at the Ag film surface by using compositional analysis in the annealing temperatures of 550 ℃. The total reflectance is decreased with increasing temperature. These phenomena are due to an out-diffusion of Si atoms from SiO2 layers during the RTA annealing. The results offer the possibility of using it as a substrate for various flexible optoelectronic devices.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.83-88
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• 2018

The electromigration (EM) tests were performed at $150^{\circ}C$ with $1.5{\times}10^5A/cm^2$ conditions in order to investigate the effect of non-conductive film (NCF) trap on the electrical reliability of Cu/Ni/Sn-Ag microbumps. The EM failure time of Cu/Ni/Sn-Ag microbump with NCF trap was around 8 times shorter than Cu/Ni/Sn-Ag microbump without NCF trap. From systematic analysis on the electrical resistance and failed interfaces, the trapped NCF-induced voids at the Sn-Ag/Ni-Sn intermetallic compound interface lead to faster EM void growth and earlier open failure.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.18 no.1_2
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• pp.1-8
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• 2012

Kimchi, a Korean fermented vegetable is packaged without pasteurization and distributed with live bacteria actively working to produce lactic acid and carbon dioxide gas in the product. The $CO_2$ production consisting of two distinct phases of initial fast and later slow rates depends on kimchi type, salt content and storage temperature. The $CO_2$ produced from kimchi is accumulated in the product package causing volume expansion and pressure buildup. The dependence of $CO_2$ production rate on salt content and storage temperature has been published formerly and can be used for estimating the package volume and pressure under a variety of storage conditions. As methods to alleviate the problems from the produced $CO_2$, package designs with controlled diffusion pinhole, high $CO_2$ permeable film or $CO_2$ absorber have been tried by several researchers. Properly designed packages adopting the device or tool were shown to have high dissolved $CO_2$ in kimchi without volume expansion and pressure buildup, giving good sensory quality with carbonic taste. Advantages and limitations of each method have been discussed.