A combination of Polycarbonate (PC) material and Polymethylmethacrylate (PMMA), fabricated using an injection molding machine, has been investigated to determine its advantages, as studied in Ref. 1). This paper aims to investigate the optimization of PMMA/PC blend for both tensile yield strength and impact strength. Furthermore, interaction effects of process conditions on mechanical properties including tensile yield strength and impact strength of PMMA/PC blend by injection molding process are interpreted in this study. Tensile and impact specimens are designed following ASTM, type V, and are fabricated by injection molding process. The processing conditions such as melt temperature, mold temperature, packing pressure, and cooling time are applied; each factor has three levels. As a result, in comparison with optimization of separated responses, mechanical properties of PMMA/PC are found to decrease when optimizing both tensile and impact strengths simultaneously. The melt temperature is found to be the most significant interaction parameter with the mold temperature and packing pressure. In addition, there is more interaction between the mold temperature and cooling time. This investigation provides a useful understanding of the control of injection molding processing of polymer blends in optical application.

The paper aims to examine the factors affecting brand and student decision in buying fresh milk. Combining qualitative and quantitative research methods, this study used self-completed questionnaires to investigate 520 students in Ho Chi Minh City. The results of the study show that that there are five key determinants affecting the dairy brand and student decision in buying fresh milk, including: (1) product quality, (2) fair price, (3) product promotion and customer services, (4) product convenience, and (5) reference group’s attitude to the brand. In addition, it is also found that product brand has a direct and positive impact on the student decision. The finding in this study is quite different from other existing literatures in terms of the importance level of the determinants of the student decision in buying fresh milk; specifically, in deciding to buy their fresh milk, students are often interested in the promotion and customer service, the product convenience, and the reference group for the purchase, more than in the quality and price of the product. From these findings, some managerial implications are proposed for policy-makers and relevant enterprises to have appropriate policies and strategies for their business development.