Multiphase composition design and entropy engineering control are promising strategies to improve the properties of ultra-high temperature ceramics (UHTCs). In this study, spark plasma sintering was used to prepare fully dense dual-phase (Zr, Hf, Ta)B₂-(Zr, Hf, Ta)C ceramics from self-synthesized equimolar medium-entropy diboride and carbide powders. The obtained ceramics comprised two distinct solid solution phases, the Zr-rich diboride phase and the Ta-rich carbide phase, indicating metal element exchange occurred between the starting equimolar medium-entropy diboride and carbide during sintering. The chemical driving force originating from the metal element exchange during the sintering process is considered to promote the densification process of the ceramics. The metal element exchange between the medium-entropy diboride and carbide phase significantly increased Young’s modulus of the dual-phase ceramics. Owing to the mutual grain-boundary pinning effect, fine-grained dual-phase ceramics were obtained. The dual-phase medium-entropy 50 vol.% (Zr, Hf, Ta)B₂-50 vol.% (Zr, Hf, Ta)C ceramics with the smallest grain size exhibited the highest hardness of 22.4 ± 0.2 GPa. It is inferred that optimized comprehensive properties or performance of dual-phase high-entropy or medium-entropy UHTCs can be achieved by adjusting both the volume content and the metal element composition of the corresponding starting powders of diborides and carbides.

New Rochelle, NY, December 18, 2024–A scoping review of indices to measure a community’s health status is published in the peer-reviewed journal Population Health Management.

Supporting the United Nation’s initiatives like “Pact for the Future" and the "International Decade of Sciences for Sustainable Development (2024–2033)," over 260 young scientists from several countries came together and signed the Wenzhou Declaration at the Global π Roundtable 2024, co-hosted by the Global Young Academy (GYA) and other organizations. The declaration commits to creating co-innovation platforms and the Global π Community to advance partnerships and innovations for sustainable development.

In a study published in Environmental Science & Technology Letters on Wednesday, researchers tested 22 watch bands purchased in the U.S. from various brands and at a range of price points. Many of the bands were manufactured using fluoroelastomers, a synthetic polymer used to make rubber material resistant to sweat, skin oils and lotions. Results showed that nine of the 22 bands tested contained elevated levels of a type of PFAS called perfluorohexanoic acid (PFHxA). Elevated levels of PFHxA were more prevalent in higher-priced watchbands, or those costing more than $15.

Researchers at Penn Engineering have decoded the genetic blueprint of Penicillium citrinum, a common citrus mold, to uncover how nature produces cyclopentachromone — a key building block for bioactive compounds with potential in cancer and inflammation treatments. The team identified a previously unknown enzyme, IscL, that creates a highly reactive sulfur-containing intermediate, offering new insights into fungal chemistry. This discovery could pave the way for novel pharmaceuticals by harnessing nature’s molecular tools.