Hyaluronic acid hydrogels (HAHs) were synthesized by immersing the micro-beads in phosphate buffered saline solution to assess shortterm biocompatibility of the gels by means of the rabbit pyrogen test and the bacterial endotoxin test. The rise in body temperature of 3 male New Zealand white rabbits weighing about 2~3 kg (12~16 weeks old) following intravenous injection of the test article (10 mL/kg) was monitored at 30 min intervals in 3 h to examine the pyrogenicity. No rabbits showed an individual rise in temperature of 0.5 o C or more above its respective control temperature. The temperature rises of the rabbits after injection were 0.12 o C, 0.13 o C, and 0.18 o C, respectively, suggesting that HAH meets the requirements for the absence of pyrogens. The bacterial endotoxin test revealed that the concentration of endotoxins required to cause the lysate to clot under standard conditions was < 0.125 EU/mL. Comparing the HAHs that was synthesized in this experiment to the ones approved by FDA, the amount of < 0.125 EU/mL endotoxins is relatively safe and effective. The test solution did not contain any interfering factors under the experimental conditions used. It is conceivable that the HAHs are likely to be suitable injectable dermal filler for facial soft tissue augmentation due to the absence of pyrogens.

>> The separation of hydrogen depends on porosity, diffusivity and solubility in permeation membrane.Dense membrane is always showing a solution diffusion mechanism but porous membrane is not showing. Therefore, porous membrane has a good hydrogen flux due to pore is carried out transferred media. This mechanism is named as the Knudsen diffusion. Hydrogen molecules or hydrogen atoms are diffused along pore that is a mean free path. In this study, complex layer hydrogen permeation membrane was fabricated by hot press process. And then, it was evaluated and calculated to relationship between hydrogen permeability and membrane porosity.

Since the 1990s, the second generation of Zirconium alloys containing main alloy compositions of Nb, Sn and Fe have been used as a replacement of Zircaloy-4 (Zr-Sn-Fe-Cr), a first-generation Zirconium alloy, to meet severe and rigorous reactor operating conditions characterized by high-burn-up, high-power and high-pH operations. In this study, the mechanical properties and creep behaviors of Zr-Sn-Fe-Cr and Zr-Nb-Sn-Fe alloys were investigated in a temperature range of 450~500 o C and in a stress range of 80~150 MPa. The mechanical testing results indicate that the yield and tensile strengths of the Zr-Nb-Sn-Fe alloy are slightly higher compared to those of Zr-Sn-Fe-Cr. This can be explained by the second phase strengthening of the β-Nb precipitates. The creep test results indicate that the stress exponent for the steady-state creep rate decreases with the increase in the applied stress. However, the stress exponent of the Zr-Sn-Fe-Cr alloy is lower than that of the Zr-Nb-Sn-Fe alloy in a relatively high stress range, whereas the creep activation energy of the former is slightly higher than that of the latter. This can be explained by the dynamic deformation aging effect caused by the interaction of dislocations with Sn substitutional atoms. A higher Sn content leads to a lower stress exponent value and higher creep activation energy.

>> Nowdays, fossil fuels have been used as an important resource in development of industry. But it is limited and caused climate change such as pollution and global warming. So nuclear fusion research is being issued with tritium to develop eco-friendly and sustainable energy. Republic of Korea is in charge of Storage and Delivery System (SDS) in the International Thermonuclear Experimental Reactor (ITER), weld present in the SDS bottles are easily exposed to the hydrogen embrittlement of special characteristics of the hydrogen in hydrogen atmosphere, When the hydrogen embrittlement is rapidly progresses, the cracking is generated in the weld zone. Due to this cracking ,the risk of leakage of tritium into the atmosphere occurs. In this study, hydrogen heat treatment was processed through the Pressure-Composition-Temperature (PCT) device according to the time variation. Also mechanical properties such as rupture strength test, three point bend test and hardness test in accordance with the respective time have been conducted and the fracture was observed by scanning electron microscopy(SEM) after the mechanical properties evaluation.

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