vacuum check
71History of radar — The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell s seminal work on electromagnetism.… …
72List of pipeline accidents — The following is a list of pipeline accidents: This is an incomplete list, which may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries. Contents 1 Bel …
73Marine chronometer — Breguet twin barrel box chronometer. Classification Clock Industry Transportation …
74art conservation and restoration — Maintenance and preservation of works of art, their protection from future damage, deterioration, or neglect, and the repair or renovation of works that have deteriorated or been damaged. Research in art history has relied heavily on 20th and… …
75building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… …
76Apollo 8 — Infobox Space mission mission name = Apollo 8 insignia = Apollo 8 patch.png command module = CM 103 mass 28,817 kg service module = SM 103 lunar module = Lunar Test Article (LTA B) mass 9,026 kg booster = Saturn V SA 503 crew size = 3 launch pad …
77Wood preservation — All measures that are taken to ensure a long life of wood fall under the definition wood preservation (timber treatment). Apart from structural wood preservation measures, there are a number of different (chemical) preservatives and processes… …
78Canonical quantization — In physics, canonical quantization is one of many procedures for quantizing a classical theory. Historically, this was the earliest method to be used to build quantum mechanics. When applied to a classical field theory it is also called second… …
79Uncontrolled decompression — refers to an unplanned drop in the pressure of a sealed system, such as an aircraft cabin and typically results from human error, material fatigue, engineering failure or impact causing a pressure vessel to vent into its lower pressure… …
80The Parting of the Ways — Doctorwhobox number=170b serial name= The Parting of the Ways caption=The TARDIS crew face the Dalek Emperor and his army. show=DW type=episode doctor=Christopher Eccleston (Ninth Doctor) David Tennant (Tenth Doctor) companion=Billie Piper (Rose… …
