Hypersonic flights, re-entry vehicles, and propulsion applications all require new materials that can perform in oxidizing or corrosive atmospheres at temperatures in excess of 2000°C and sometimes over the course of a long working life. Ultra High Temperature Ceramics (UHTCs) are good candidates to fulfill these requirements. Within this family, the ZrB2 and HfB2 based composites are the most ...

The Ultra High Temperature Ceramics (UHTCs) represent a very interesting family of materials and therefore they are the subject of increasing attention from different engineering sectors and notably the aerospace industry. Indeed, hypersonic flights, re-entry vehicles, propulsion applications and so on, require new materials that can perform in oxidizing or corrosive atmospheres at temperatures...

Our activities affect the environment and. the environment affects our health. As the number of humans on earth increases, our agricultural and industrial activities have a greater impact on the environment, particularly on the atmosphere. As our most precious resource, the atmosphere has been polluted, so it is imperative to take measures to control air pollution. It becomes necessary to know ...

nowadays, suppliers in order to maintain and improve their positions against othernational and international suppliers take advantage of their brand equity, but the problem is that industrial suppliers do not know what factors are influencing for development and promotion industrial brand equity and also do not know how to enhance brand equity, to improve brand performance in industrial markets...

post – materialism and political science development dr. hossein salimi in social science area, some think that scientific studies require and content a hidden materialism. they believe a sort of interconnection and synchronization between materialism and scientific studies, however emerging and expansion of post-materialism school reveals that it is not right. in the article it will be endeavo...