In this study, a highly sensitive analysis device for hydrogen sulfide that could be used quickly and easily on site was developed using a colorimetric paper sensor. To optimize analysis conditions, tests were performed for each function. Performances of the method using laboratory equipment and tools and the method using the developed device for hydrogen sulfide analysis were compared. The trend line of changes in parameter b of the image acquired by the on-site analytical device for hydrogen sulfide was calculated as y = 0.517x - 0.141 with a coefficient of determination (R2) of 0.9874. It was comparable to the method performed at the laboratory level, showing an excellent linearity. Using the calculated trend line as a calibration curve, the detection limit and quantification limit were found to be 2.386 μM and 7.952 μM, respectively. A reproducibility test showed a relative standard deviation of 5.7%, indicating a low dispersion of results.

A fixing frame applied with Foam Cored CFRP Sandwich Composite (FCCSC) that replaces SAPH440 steel used in the fixing frame for hydrogen storage was designed, and its structural safety was evaluated. In the design of the fixing frame, FCCSC was implemented by PMI foam core, a Bakelite mount, and Carbon Fiber Reinforced Plastics (CFRP) using woven carbon fiber prepreg. Unlike the steel fixing frame, the FCCSC-applied fixing frame had a cross-section of hollow-rectangular, and its validity was confirmed through finite element analysis. Structural analysis of the designed FCCSCapplied fixing frame and steel fixing frame was performed. Under the extreme load condition of 9G acceleration, the steel fixing frame showed the lowest safety factor of 1.14 based on the yield strength in the opposite direction of gravity. On the other hand, the FCCSC-applied fixing frame showed a safety factor of 7.6 at the maximum principal stress and 3.15 at the shear stress. Through this result of structural analysis, it was verified that the FCCSC-applied fixing frame, which was 25.8% lighter than the steel fixing frame, was 1.8 times safer.

Cold gas dynamic spray is a relatively new coating process by which coatings can be produced without significant heating during the process. Cold-spray uses supersonic gas flow to carry metallic powders to the substrate. Its low process temperature can minimize thermal stress and also reduce the deformation of the substrate. Most researches on cold-spray have focused on micro scale coating, but in this study macro scale deposition was conducted. Properties of aluminum layer by cold-spray deposition such as coefficient of thermal expansion (CTE), modulus of elasticity, hardness, and electric conductivity were measured. The results showed that properties of aluminum layer by cold-spray deposition were different from properties of pure aluminum and aluminum alloy.