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Glass Fiber Reinforced Polymer (GFRP) is widely used as aerospace material requiring high specific strength, specific stiffness, and excellent mechanical and chemical properties. To apply the already approved composite materials to other processes, an equivalency test that compares the mechanical properties of the composite materials based on the database is required. For the successful completion of the equivalency test, it is important to control the factors affecting the mechanical properties. The resin content and density of the specimens are manufactured differently according to the process. The effect of these factors on the change of mechanical properties required for equivalency qualification has not been sufficiently reported. In this study, an equivalency test was performed on the GFRP applied to the aircraft radome based on the procedure of the equivalency test and acceptance test proposed by the National Center for Advanced Materials Performance. The causes of problems occurring between equivalency tests were analyzed. It was confirmed that the resin content, density, and voids of the specimen affect the mechanical properties. As the resin content decreases, the density and voids were controlled, and it was confirmed that the average strength and modulus increase by 13.12 and 6.78%, respectively. The equivalency qualification was completed by applying an improved process in which these factors were controlled.

The study aimed to investigate the impact of oxygen vacancies on the reliability of perovskite-structured ceramics. In particular, the focus was on anti-ferroelectric (PbLa)(ZrTi)O3, commonly known as PLZT, which exhibits excellent DC-bias characteristics, making it a promising material for high-power capacitors. To address the issue of oxygen vacancies, Dy3+ was introduced as a donor by substituting it into (Pb0.82La0.12)(Zr0.86Ti0.14)O3. As the substitution of Dy3+ increased, there was a decrease in the dielectric constant. However, this was accompanied by an increase in both breakdown voltage and reliability characteristics. [ABSTRACT FROM AUTHOR]

Perilipin (PLIN) is a major structural protein located on the surface of lipid droplets. PLIN plays an important role in human metabolism and is associated with metabolic diseases, such as obesity, diabetes, hypertension, and endocrine disorders. The dysregulation of lipid metabolism is one of the most prominent metabolic changes observed in cancers. Therefore, the PLIN protein family has recently attracted attention owing to its role in lipid metabolism and cancer. To date, no studies have addressed the association between the prognosis of lung cancer and PLIN1 expression. For the first time, we found that high PLIN1 expression was significantly correlated with worse disease-free survival (DFS) in lung squamous cell carcinoma (SCC). We examined PLIN1 expression by the immunohistochemical analysis of surgical lung SCC specimens obtained from 94 patients. We analyzed the correlation between PLIN1 expression, clinicopathological data, and patient survival, using a chi-squared test, Kaplan–Meier analysis with log-rank tests, and the multivariate Cox proportional hazards regression test. High PLIN1 expression was significantly correlated with lower DFS in the Kaplan–Meier analysis and the multivariate Cox proportional hazards regression model. High PLIN1 expression was significantly correlated with worse prognosis in lung SCC. [ABSTRACT FROM AUTHOR]

Composite specimens with resin contents of 33.5%, 35.4%, and 35.9%, respectively, were manufactured by controlling the type of subsidiary material used in the bagging process for a composite material having the same composition. The effect of controlling the resin content on the microstructure and mechanical properties of composite specimens was investigated. The flow of resin and air during the cure process was inferred and explained by connecting it with the microstructure. Specifically, the behavior of the resin determined the thickness, density, and void of the composite laminate, which acted as a factor causing the difference in mechanical properties of the composite materials. As the resin content increased, there was no significant difference in tensile strength, but Young's modulus decreased. In the case of the compression test, there was a difference in mechanical properties due to the combined effect of the reinforcement and the resin. The maximum compressive strength value was shown in the process with low void content, and Young's modulus tended to decrease as the resin content increased. In the bagging process, the subsidiary material controlled the flow of resin and air, and caused a difference in microstructure, affecting the change of mechanical properties. [ABSTRACT FROM AUTHOR]

It is necessary to develop a low‐loss dielectric material based on the low‐temperature co‐fired ceramic (LTCC) process, which is essential for expanding 5G service. LTCC is designed by mixing SiO2 and glass to secure low dielectric constant. The density, porosity, and average diameter of pores of the sintered specimen are analyzed and evaluated to confirm the change in sintering behavior according to the mixing composition ratio of SiO2 and glass and the heating rate. When the ratio of the mixed filler is 35 vol%, the density is the highest at 2.30 g cm−3, the porosity is the lowest at 4.59%, and the diameter of the pores is also the smallest at about 5.80 μm. Therefore, it is selected as the optimal mixing ratio. When the heating rate is used as a variable, the density is high in 1, 3, and 5 °C min−1, and the porosity and pore diameter are small. However, it is confirmed that as the heating rate increases, the density gradually decreases, while the porosity as well as pore diameter increases. As a result of analyzing the sample under the optimal conditions, the dielectric constant 3.64 and loss 0.01 are shown in 30 GHz. [ABSTRACT FROM AUTHOR]