Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

Expand All
Entries
Topic Review
Mast Aft Rig
A mast aft rig, alternately referred to as aft-mast rig, is a sailboat sail-plan that uses a single mast set in the aft half of the hull. The mast supports fore-sails that may consist of a single jib multiple staysails, or a crab claw sail. The mainsail is either small or completely absent. Mast aft rigs are uncommon, but are found on a few custom, and production sailboats.
  • 970
  • 01 Nov 2022
Topic Review
Ethical Arguments Regarding Torture
Ethical arguments have arisen regarding torture, and its debated value to society. Despite worldwide condemnation and the existence of treaty provisions that forbid it, some countries still use it. The ethical assertion that torture is a tool is at question.
  • 1.4K
  • 01 Nov 2022
Topic Review
Dell EMC ScaleIO
Dell EMC PowerFlex (previously known as ScaleIO and VxFlex OS), is a commercial software-defined storage product from Dell EMC that creates a server-based storage area network (SAN) from local server storage using x86 servers. It converts this direct-attached storage into shared block storage than runs over an IP-based network. PowerFlex can scale from three compute/storage nodes to over 1,000 nodes that can drive up to 240 million IOPS of performance. PowerFlex is bundled with Dell EMC commodity computing servers (officially called VxFlex Ready Nodes, PowerFlex appliance, and PowerFlex rack). PowerFlex can be deployed as storage only or as a converged infrastructure combining storage, computational and networking resources into a single block. Capacity and performance of all available resources are aggregated and made available to every participating PowerFlex server and application. Storage tiers can be created with media types and drive types that match the ideal performance or capacity characteristics to best suit the application needs.
  • 1.5K
  • 01 Nov 2022
Topic Review
Društvo Sa Ograničenom Odgovornošću
Društvo sa ograničenom odgovornošću (Serbian Cyrillic: друштво са ограниченом одговорношћу; abbr. d.o.o., Serbian Cyrillic: д.о.о.) is a kind of legal corporate entity in and Serbia which literally means (but is not entirely equal to) "limited liability society". It is often confused with the American term limited liability company, with which it shares some characteristics, but it is more similar to a limited partnership.
  • 3.2K
  • 01 Nov 2022
Topic Review
FFAG Accelerator
A Fixed-Field Alternating Gradient accelerator (FFAG) is a circular particle accelerator concept on which development was started in the early 50s, and that can be characterized by its time-independent magnetic fields (fixed-field, like in a cyclotron) and the use of strong focusing (alternating gradient, like in a synchrotron). Thus, FFAG accelerators combine the cyclotron's advantage of continuous, unpulsed operation, with the synchrotron's relatively inexpensive small magnet ring, of narrow bore. Although the development of FFAGs had not been pursued for over a decade starting from 1967, it has regained interest since the mid-1980s for usage in neutron spallation sources, as a driver for muon colliders and to accelerate muons in a neutrino factory since the mid-1990s. The revival in FFAG research has been particularly strong in Japan with the construction of several rings. This resurgence has been prompted in part by advances in RF cavities and in magnet design.
  • 2.6K
  • 01 Nov 2022
Topic Review
Fuel Economy in Aircraft
The fuel economy in aircraft is the measure of the transport energy efficiency of aircraft. Efficiency is increased with better aerodynamics and by reducing weight, and with improved engine BSFC and propulsive efficiency or TSFC. Endurance and range can be maximized with the optimum airspeed, and economy is better at optimum altitudes, usually higher. An airline efficiency depends on its fleet fuel burn, seating density, air cargo and passenger load factor, while operational procedures like maintenance and routing can save fuel. Average fuel burn of new aircraft fell 45% from 1968 to 2014, a compounded annual reduction 1.3% with a variable reduction rate. In 2018, CO₂ emissions totalled 747 million tonnes for passenger transport, for 8.5 trillion revenue passenger kilometres (RPK), giving an average of 88 gram CO₂ per RPK. A 88 gCO₂/km represents 28 g of fuel per km, or a 3.5 L/100 km (67 mpg‑US) fuel consumption. New technology can reduce engine fuel consumption, like higher pressure and bypass ratios, geared turbofans, open rotors, hybrid electric or fully electric propulsion; and airframe efficiency with retrofits, better materials and systems and advanced aerodynamics.
  • 21.0K
  • 01 Nov 2022
Topic Review
Ficksburg
Ficksburg is a town situated at the foot of the 1,750 meter high Imperani Mountain in Free State province, South Africa . The town was founded by General Johan Fick in 1867 who won the territory in the Basotho Wars. He laid out many erven and plots that could be bought at a reasonable price. The town was later proclaimed a municipality in 1891. The last Governor-General of the Union of South Africa and the first State President of South Africa, Charles Robberts Swart was imprisoned here by the United Kingdom in 1914 and released one day before his scheduled execution.
  • 2.0K
  • 01 Nov 2022
Topic Review
Irritator
Irritator is a genus of spinosaurid dinosaur that lived in what is now Brazil during the Albian stage of the Early Cretaceous Period, about 113 to 110 million years ago. It is known from a nearly complete skull found in the Romualdo Formation of the Araripe Basin. Fossil dealers had acquired this skull and sold it to the State Museum of Natural History Stuttgart. In 1996, the specimen became the holotype of the type species Irritator challengeri. The genus name comes from the word "irritation", reflecting the feelings of paleontologists who found the skull had been heavily damaged and altered by the collectors. The species name is a homage to the fictional character Professor Challenger from Arthur Conan Doyle's novels. Some paleontologists regard Angaturama limai—known from a snout tip that was described later in 1996—as a potential junior synonym of Irritator. Both animals hail from the same stratigraphic units of the Araripe Basin. It was also previously proposed that Irritator and Angaturama's skull parts belonged to the same specimen. Although this has been cast into doubt, more overlapping fossil material is needed to confirm whether they are the same animal or not. Other spinosaurid skeletal material, some of which could belong to Irritator or Angaturama, was retrieved from the Romualdo Formation, allowing for a replica skeleton to be made and mounted for display at the National Museum of Rio de Janeiro in 2009. Estimated at between 6 and 8 meters (20 and 26 ft) in length, Irritator weighed around 1 tonne (1.1 short tons), making it one of the smallest spinosaurids known. Its long, shallow and slender snout was lined with straight and unserrated conical teeth. Lengthwise atop the head ran a thin sagittal crest, to which powerful neck muscles were likely anchored. The nostrils were positioned far back from the tip of the snout, and a rigid secondary palate on the roof of the mouth would have strengthened the jaw when feeding. Belonging to a subadult, Irritator challengeri's holotype remains the most completely preserved spinosaurid skull yet found. The Angaturama snout tip expanded to the sides in a rosette-like shape, bearing long teeth and an unusually tall crest. One possible skeleton indicates it, like other spinosaurids, had enlarged first-finger claws and a sail running down its back. Irritator had been mistaken initially for a pterosaur, and later a maniraptoran dinosaur. In 1996, the animal was identified as a spinosaurid theropod. The holotype skull was thoroughly prepared before being redescribed in 2002, confirming this classification. Both Irritator and Angaturama belong to the Spinosaurinae subfamily. A generalist diet—like that of today's crocodilians—has been suggested; Irritator might have preyed mainly on fish and any other small prey animals it could catch. Fossil evidence is known of an individual that ate a pterosaur, either from hunting or scavenging it. Irritator may have had semiaquatic habits, and inhabited the tropical environment of a coastal lagoon surrounded by dry regions. It coexisted with other carnivorous theropods as well as turtles, crocodyliforms, and a large number of pterosaur and fish species.
  • 4.8K
  • 03 Nov 2022
Topic Review
List of Species Found in Antarctica
Antarctica is one of the most physically and chemically extreme terrestrial environments to be inhabited by lifeforms. The largest plants are mosses, and the largest animals that do not leave the continent are a few species of insects.
  • 851
  • 01 Nov 2022
Topic Review
Desert Island Discs
Desert Island Discs is a radio programme broadcast on BBC Radio 4. It was first broadcast on the BBC Forces Programme on 29 January 1942. Each week a guest, called a 'castaway' during the programme, is asked to choose eight recordings (usually, but not always, music), a book and a luxury item that they would take if they were to be cast away on a desert island, whilst discussing their lives and the reasons for their choices. It was devised and originally presented by Roy Plomley. Since 2006, the programme has been presented by Kirsty Young. More than 3,000 episodes have been recorded, with some guests having appeared more than once and some episodes featuring more than one guest. An example of a guest who falls into both categories is Bob Monkhouse, who appeared with his co-writer Denis Goodwin on 12 December 1955 and in his own right on 20 December 1998.
  • 2.1K
  • 01 Nov 2022
  • Page
  • of
  • 863

Other Entry Collections

>>