Element 40 in our International Year of the Periodic Table series is zirconium. Its compounds are commonly used in jewellery to simulate diamonds, and in ceramic knives. It also finds use in nuclear power stations. Cubic zirconia is a form of zirconium dioxide. Due to its similarity in appearance to diamonds, coupled with its much …
Month: June 2019
Thermocapillary migration is an interfacial phenomenon that describes liquid flow on a nonisothermal surface from warm to cold regions in the absence of external forces. It is a typical lubricant loss mechanism in tribosystems. To ensure continued reliability of lubricated assemblies, knowledge of the migration capacity of different liquids and solids is needed. In the …
Pad–Pivot Friction Effect on Nonlinear Response of a Rotor Supported by Tilting-Pad Journal Bearings
This paper presents a numerical study for nonlinear rotordynamic response with bifurcations of tilting pad journal bearings when pad–pivot friction forces are taken into account. A Stribeck friction model is employed to determine the friction coefficient for the contacts between the pads and the spherical-type pivots. The boundary/mixed/hydrodynamic friction mode is determined for each pad …
Has your local coffee shop recently switched to biodegradable cups? Or maybe your workplace canteen has made the switch to biodegradable cutlery? Perhaps the plastic packaging of your favourite magazine is now a biodegradable wrapper? You might wonder what materials are behind these biodegradable products, and exactly how much better they are for the environment …
Element 39 in our International Year of the Periodic Table series is yttrium. One of a number of elements discovered in the mines at Ytterby, Sweden, yttrium is found in camera lenses, some mock gemstones, and white LEDs. Yttrium oxide can be added to glass to make it heat and shock resistant. The oxide was …
Element 39 in our International Year of the Periodic Table series is yttrium. One of a number of elements discovered in the mines at Ytterby, Sweden, yttrium is found in camera lenses, some mock gemstones, and white LEDs. Yttrium oxide can be added to glass to make it heat and shock resistant. The oxide was …
Element 38 in our International Year of the Periodic Table series is strontium. Named after Strontian, a village in Scotland where it was discovered, strontium finds use in glow-in-the-dark paints and in toothpastes. Glow-in-the-dark paints usually contain either zinc sulfide or strontium aluminate. Both of these give the paint phosphorescent qualities; this means it absorbs …
Element 37 in our International Year of the Periodic Table series is rubidium. Used in GPS satellites and in some types of perovskite solar cells, one of its isotopes can also be used to locate and image brain tumours. Rubidium is at the more reactive end of group 1 of the periodic table. This means …
The chemical industry accounts for about 10% of the world’s energy demand and 7% of its greenhouse gas emissions. This graphic in Chemical & Engineering News takes a look at the top 5 chemical products responsible. Click through to the C&EN site to view the full graphic. The graphic accompanies a more in-depth article looking …
Element 35 in our International Year of the Periodic Table series is krypton. Used in high-speed flash photography, krypton also has a link to the definition of the metre and can help detect covert nuclear facilities. One of krypton’s common everyday uses is in some types of photographic flashes, particularly those for high-speed photography. It’s also …
