The London Fire Brigade is the statutory fire and rescue service for Greater London. It is run by the London Fire and Emergency Planning Authority and is the third largest fire service in the world. National Health Service ambulance services are provided by the London Ambulance Service (LAS) NHS Trust, the largest free-at-the-point-of-use emergency ambulance service in the world. The London Air Ambulance charity operates in conjunction with the LAS where required. Her Majesty's Coastguard and the Royal National Lifeboat Institution operate on the River Thames, which is under the jurisdiction of the Port of London Authority from Teddington Lock to the sea.
What agency operates in conjunction with the LAS as needed?
The London Air Ambulance charity

The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance. Crystals of silicon are used, as they are available in high quality and purity by the technology developed for the semiconductor industry. The unit cell volume is calculated from the spacing between two crystal planes referred to as d220. The molar volume Vm(Si) requires a knowledge of the density of the crystal and the atomic weight of the silicon used. The Planck constant is given by
What element is used typically to establish Avogadro's constant?
Crystals of silicon

Starting in 2006, Apple's industrial design shifted to favor aluminum, which was used in the construction of the first MacBook Pro. Glass was added in 2008 with the introduction of the unibody MacBook Pro. These materials are billed as environmentally friendly. The iMac, MacBook Pro, MacBook Air, and Mac Mini lines currently all use aluminum enclosures, and are now made of a single unibody. Chief designer Jonathan Ive continues to guide products towards a minimalist and simple feel, including eliminating of replaceable batteries in notebooks. Multi-touch gestures from the iPhone's interface have been applied to the Mac line in the form of touch pads on notebooks and the Magic Mouse and Magic Trackpad for desktops.
Which Mac used aluminum in it's construction?
MacBook Pro