Span

Span may refer to:

Science, technology and engineering

Mathematics

Computing

Johan Baptist Spanoghe

Johan Baptist Spanoghe (1798, Madras – 22 April 1838, Pekalongan, Java) was a Dutch botanical collector of Belgian parentage.

A native of Madras, then part of British India, in 1816 he became a civil servant with the Dutch East Indies government. In 1821 he was named as an "assistant resident" for the southern divisions of the Bantam Residency in western Java. From 1831 to 1836, he was stationed on the island of Timor.

As a botanist in the East Indies, he collected plants in Java, Timor and neighboring islands, and also in Bali. The genus Spanoghea was named in his honor by Carl Ludwig Blume, who for a period of time, worked closely with Spanoghe in Java.

Publications

References

Span (architecture)

Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways.

The span is a significant factor in finding the strength and size of a beam as it determines the maximum bending moment and deflection. The maximum bending moment and deflection in the pictured beam is found using:

where

Note that the maximum bending moment and deflection occur midway between the two supports. From this it follows that if the span is doubled, the maximum moment (and with it the stress) will quadruple, and deflection will increase by a factor of sixteen.

For long-distance rope spans, used as power line, antenna or for aerial tramways, see list of spans.

References

Seah (unit)

The se'ah or seah (Hebrew: סאה‎) is a unit of dry measure of ancient origin used in Halakha (Jewish law), which equals one third of an ephah, or bath. Its size in modern units varies widely according to the criteria used for defining it.

According to Herbert G. May, chief editor of two classic Bible-related reference books, the bath may be archaeologically determined to have been about 5.75 gallons (22 liters) from a study of jar remains marked 'bath' and 'royal bath' from Tell Beit Mirsim. Since the bath unit has been established to be 22 litres, 1 se'ah would equal 7.33 litres or 7.33dm³.

In the context of a mikveh, a se'ah can be about twice as much in order to accommodate even the most stringent rabbinical ruling on immersion. A mikveh must, according to the classical regulations, contain enough water to cover the entire body of an average-sized person; based on a mikveh with the dimensions of 3 cubits deep, 1 cubit wide, and 1 cubit long, the necessary volume of water was estimated as being 40 se'ah of water. The exact volume referred to by a seah is debated, and classical rabbinical literature specifies only that it is enough to fit 144 eggs; most Orthodox Jews use the stringent ruling of the Avrohom Yeshaya Karelitz, according to which one seah is 14.3 litres, and therefore a mikveh must contain approximately 575 litres . This volume of water could be topped up with water from any source, but if there were less than 40 seahs of water in the mikveh, then the addition of 3 or more pints of water from an unnatural source would render the mikveh unfit for use, regardless of whether water from a natural source was then added to make up 40 seahs from a natural source; a mikveh rendered unfit for use in this way would need to be completely drained away and refilled from scratch.

Hobart-class destroyer

The Hobart class is a ship class of three air warfare destroyers (AWDs) being built for the Royal Australian Navy (RAN). Planning for ships to replace the Adelaide-class frigates and restore the capability last exhibited by the Perth-class destroyers began by 2000, initially under acquisition project SEA 1400, which was redesignated SEA 4000. Although the designation "Air Warfare Destroyer" is used to describe ships dedicated to the defence of a naval force (plus assets ashore) from aircraft and missile attack, the planned Australian destroyers are expected to also operate in anti-surface, anti-submarine, and naval gunfire support roles.

Planning for the Australian Air Warfare Destroyer (as the class was known until 2006) continued through the mid-2000s, with the selection of the Aegis combat system as the intended combat system and ASC as the primary shipbuilder in 2005. In late 2005, the AWD Alliance was formed as a consortium of the Defence Materiel Organisation (DMO), ASC, and Raytheon. Between 2005 and 2007, Gibbs & Cox's Evolved Arleigh Burke-class destroyer concept and Navantia's Álvaro de Bazán-class frigate competed for selection as the AWD design. Although the Arleigh Burke design was larger and more capable, the Álvaro de Bazán design was selected in June 2007 as it was an existing design, and would be cheaper, quicker, and less risky to build.

Collins-class submarine replacement project

Identified as the most expensive defence procurement project to date in Australian history, the Collins-class replacement will provide Australia with a submarine capability deep into the twenty-first century. With the Royal Australian Navy's (RAN's) Collins-class submarines scheduled to begin leaving service from 2025 onwards, plans to replace them began in 2007 with the commencement of the defence acquisition project SEA 1000, also referred to as the Future Submarine Programme. Australia's unique operating environment (including significant variations in ocean climate and conditions) and rejection of nuclear propulsion had previously driven it to operate in the Collins-class the world's largest diesel-electric submarines, capable of transiting the long distances from HMAS Stirling to their deployment areas.

In the early phases of the replacement project, four design options were identified: purchase a Military-Off-The-Shelf (MOTS) design, modify a MOTS design for Australian conditions, design an evolution of the Collins-class, or create a new design. Nuclear propulsion has been ruled out due to the lack of an indigenous nuclear industry in Australia and public opposition to nuclear technology.