Search

...carbon and oxygen in the star’s core, again releasing energy. Low mass stars (< 3 M☉) and intermediate mass stars (in the range 3–8 M☉) ultimately begin a second ascent of the red giant branch (known as the asymptotic giant branch, or AGB) when core helium is exhausted and helium fusion only continues in a shell surrounding an inert carbon/oxygen core. Massive...

...carbon-rich) material erupted from geysers. The rugged surface beyond the polar cap is methane-rich ice, contaminated by nitrogen, carbon dioxide, carbon monoxide and water. (NASA) Beyond its large satellites each giant planet has a second collection of small irregular-shaped satellites, travelling in elongated, inclined and in many cases retrograde orbits. Most are dark...

...carbon content is hard-wearing, and that is just what is required for drive-shafts, bearings and gear teeth. But if we choose a recipe that makes steel hard for a service requirement, how can we get around the fact that its hardness will make it extremely difficult to shape in the first place? One answer is to fashion the components from a steel of a more formable,...

...carbon and nitrogen isotopic composition of these very important extraterrestrial samples. The arrival of the Winchcombe meteorite is a big bonus for UK science. Samples from the asteroid Ryugu have just been returned to Earth by the Japanese Space Agency JAXA and the NASA mission OSIRIS-REx will be returning samples from asteroid Bennu in 2023. Asteroids Ryugu and Bennu...

...carbon and alloy steels, graphite and copper-2% beryllium. Die coatings and chills are used to control the solidification and amount of shrinkage porosity. Die coatings, which are applied by spraying or dipping, should prevent metal from sticking to the die, insulate, lubricate, allow adequate ventilation and be durable. With clean, modified and grain-refined aluminium...

...carbonate has a median lethal dose (LD50 or toxic to 50% of the subjects) in rats of 525mg/kg when administered orally. However, it may be safely prescribed to humans at a therapeutic dose to treat, for instance, depression, but the levels of toxicity mean it has to be prescribed and taken carefully to avoid an overdose. Unfortunately, it has been reported to contribute...