Calming fears, easing pain. Children's anesthesia tricky

To a child, pain and fear are inseparable. How to safely relieve both is a subject of growing debate and research. Only recently has a narcotic drug been approved specifically for children, and its use is controversial.     

Shiley saga leads to improved communication

Certain heart valves manufactured by Shiley, Inc., turned out to have increased fracture rates. Alerting doctors and patients to this problem has changed the way FDA expects manufacturers to communicate significant risks with medical devices.     

Process simulation and fabrication of advanced multi-step three-dimensional braided preforms

The fundamentals of multi-step braiding for the fabrication of three-dimensional fibre preforms for composites have been studied. To facilitate the understanding of the complex multi-step braiding processes, a computer simulation algorithm has been developed. The simulation acts as a tool to allow the identification of individual yarn paths, number and location of yarn groups, and braid geometry. It was found that individual control of the rows and columns of yarn carriers on a Cartesian braiding bed allows for the fabrication of advanced multi-step braids; the micro-structural possibilities of three-dimensional braids are thus greatly extended. Some basic relationships of the braiding parameters have been identified. It has been concluded that the traditional four-step and two-step braidings are special cases of multi-step braidings. To verify the feasibility of the structures, experimental investigations have also been carried out. Innovative braid architectures have been designed and fabricated using a prototype multi-step braiding machine.     

Influence of alloying elements on the structure and wear resistance of chilled cast iron

To work out the optimal chemical composition of wear-resistant cast iron with a pearlitic metallic matrix that is able to restore the relief of a rough surface, we investigated the properties of cast iron with different composition by the method of single factor experiment.Nizhnii Novgorod Branch of the Central Research Institute of Structural Materials Prometei. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 37–39, June, 1994.