Royal Society of Chemistry
The Royal Society of Chemistry is a learned society in the United Kingdom with the goal of "advancing the chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad; the headquarters of the Society are at Burlington House, London. It has offices in Thomas Graham House in Cambridge where RSC Publishing is based; the Society has offices in the United States at the University City Science Center, Philadelphia, in both Beijing and Shanghai and Bangalore, India. The organisation carries out research, publishes journals and databases, as well as hosting conferences and workshops, it is the professional body for chemistry in the UK, with the ability to award the status of Chartered Chemist and, through the Science Council the awards of Chartered Scientist, Registered Scientist and Registered Science Technician to suitably qualified candidates.
The designation FRSC is given to a group of elected Fellows of the society who have made major contributions to chemistry and other interface disciplines such as biological chemistry. The names of Fellows are published each year in The Times. Honorary Fellowship of the Society is awarded for distinguished service in the field of chemistry; the president is elected biennially and wears a badge in the form of a spoked wheel, with the standing figure of Joseph Priestley depicted in enamel in red and blue, on a hexagonal medallion in the centre. The rim of the wheel is gold, the twelve spokes are of non-tarnishable metals; the current president is Dame Carol V. Robinson. Past presidents of the society have been: The following are membership grades with post-nominals: Affiliate: The grade for students and those involved in chemistry who do not meet the requirements for the following grades. AMRSC: Associate Member, Royal Society of Chemistry The entry level for RSC membership, AMRSC is awarded to graduates in the chemical sciences.
MRSC: Member, Royal Society of Chemistry Awarded to graduates with at least 3 years' experience, who have acquired key skills through professional activity FRSC: Fellow of the Royal Society of Chemistry Fellowship may be awarded to nominees who have made an outstanding contribution to chemistry. HonFRSC: Honorary Fellow of the Society Honorary Fellowship is awarded for distinguished service in the field of chemistry. CChem: Chartered Chemist The award of CChem is considered separately from admission to a category of RSC membership. Candidates need to be MRSC or FRSC and demonstrate development of specific professional attributes and be in a job which requires their chemical knowledge and skills. CSci: Chartered Scientist The RSC is a licensed by the Science Council for the registration of Chartered Scientists. EurChem: European Chemist The RSC is a member of the European Communities Chemistry Council, can award this designation to Chartered Chemists. MChemA: Mastership in Chemical Analysis The RSC awards this postgraduate qualification, the UK statutory qualification for practice as a Public Analyst.
It requires candidates to submit a portfolio of suitable experience and to take theory papers and a one-day laboratory practical examination. The qualification GRSC was awarded from 1981 to 1995 for completion of college courses equivalent to an honours chemistry degree and overseen by the RSC, it replaced the GRIC offered by the Royal Institute of Chemistry. The society is organised around 9 divisions, based on subject areas, local sections, both in the United Kingdom and overseas. Divisions cover broad areas of chemistry but contain many special interest groups for more specific areas. Analytical Division for analytical chemistry and promoting the original aims of the Society for Analytical Chemistry. 12 Subject Groups. Dalton Division, named after John Dalton, for inorganic chemistry. 6 Subject Groups. Education Division for chemical education. 4 Subject Groups. Faraday Division, named after Michael Faraday, for physical chemistry and promoting the original aims of the Faraday Society. 14 Subject Groups.
Organic Division for organic chemistry. 6 Subject Groups. Chemical Biology Interface Division. 2 Subject Groups. Environment and Energy Division. 3 Subject Groups. Materials Chemistry Division. 4 Subject Groups. Industry and Technology Division. 13 Subject Groups. There are 12 subjects groups not attached to a division. There are 35 local sections covering the United Ireland. In countries of the Commonwealth of Nations and many other countries there are Local Representatives of the society and some activities; the society is a not-for-profit publisher: surplus made by its publishing business is invested to support its aim of advancing the chemical sciences. In addition to scientific journals, including its flagship journals Chemical Communications, Chemical Science and Chemical Society Reviews, the society publishes: Education in Chemistry for teachers. A free online journal for chemistry educators, Chemistry Education Research and Practice. A general chemistry magazine Chemistry World, sent monthly to all members of the Society throughout the world.
The editorial board consists of 10 industrial chemists. It was first published in January 2004, it replaced C
Obsolescence is the state of being which occurs when an object, service, or practice is no longer wanted though it may still be in good working order. Obsolescence occurs because a replacement has become available that has, in sum, more advantages compared to the disadvantages incurred by maintaining or repairing the original. Obsolete refers to something, disused or discarded, or antiquated. Obsolescence is preceded by a gradual decline in popularity. Driven by rapid technological changes, new components are developed and launched on the market with increasing speed; the result is a dramatic change in production methods of all components and their market availability. A growing industry sector is facing issues where life cycles of products no longer fit together with life cycles of required components; this issue is known as obsolescence, the status given to a part when it is no longer available from its original manufacturer. The problem of obsolescence is most prevalent for electronics technology, wherein the procurement lifetimes for microelectronic parts are significantly shorter than the manufacturing and support life cycles for the products that use the parts.
However, obsolescence extends beyond electronic components to other items, such as materials and mechanical parts. In addition, obsolescence has been shown to appear for software, standards and soft resources, such as human skills, it is important to implement and operate an active management of obsolescence to mitigate and avoid extreme costs. Technical obsolescence occurs when a new product or technology supersedes the old one, it is preferred to use the new technology instead. Historical examples of new technologies superseding old ones include bronze replacing flint in hand-tools, DVDs replacing videocassettes, the telephone replacing the telegraph. On a smaller scale, a particular product may become obsolete. Many products in the computer industry become obsolete in this manner. For example, central processing units become obsolete in favor of newer, faster units. Singularly, rapid obsolescence of data formats along with their supporting hardware and software can lead to loss of critical information, a process known as digital obsolescence.
In many cases, a new technology does not replace the old technology because the old technology is still useful in certain applications. For example, transistors replaced vacuum tubes in TV and radio receivers in the 1960s, but vacuum tubes were still used for powerful transmitters because transistors for these power levels were not available. Today, one has to use multiple transistors for a purpose that used to require just one tube. Products may become obsolete when supporting technologies are no longer available to produce or repair a product. For example, many integrated circuits, including CPUs, memory and some simple logic chips may no longer be produced because the technology has been superseded, their original developer has gone out of business or a competitor has bought them out and killed off their products to remove competition, it is worth redeveloping a product to get around these issues since its overall functionality and price/performance ratio has been superseded by that time as well.
Some products become technologically obsolete due to changes in complementary products which results in the function of the first product being made unnecessary. For example, buggy whips became obsolete when people started to travel in cars rather than in horse-drawn buggies. Items become functionally obsolete when they can no longer adequately perform the function for which they were created. For example, while one could theoretically adapt an Avro Lancaster to deploy modern JDAM bombs, the situations in which it could succeed at doing so against modern air defenses would be so few that it would be useless. Manufacturers and repair companies will cease support for products once they become obsolete as keeping production lines in place and parts in storage for a shrinking user base becomes unprofitable; this causes scarcity of spare parts and skilled technicians for repairs and thus escalates maintenance costs for obsolete products. This leads to prohibitive expense in keeping old technology functioning.
The term "obsolescence" was first applied to the built environment in 1910 in an attempt to explain American skyscrapers' sudden loss of value. New York engineer Reginald P. Bolton attributed this phenomenon to "something new and better out-competing the old" and calculated the average architectural lifespan of varying building types in order to formulate a rough estimate for their impending obsolescence. For example, he suggested that hotel's obsolescence will occur faster than banks due to their ever-changing functions and tastes. Sometimes marketers deliberately introduce obsolescence into their product strategy, with the objective of generating long-term sales volume by reducing the time between repeat purchases. One example might be producing an appliance, deliberately designed to wear out within five years of its purchase, pushing consumers to replace it within five years; when a product is no longer desirable because it has gone out of the popular fashion, its style is obsolete. One example is flared leg jeans.
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Apatosaurus is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, A. ajax, in 1877, a second species, A. louisae, was discovered and named by William H. Holland in 1916. Apatosaurus lived about 152 to 151 million years ago, during the late Kimmeridgian to early Tithonian age, are now known from fossils in the Morrison Formation of modern-day Colorado, New Mexico and Utah in the United States. Apatosaurus had an average length of 21–22.8 m, an average mass of 16.4–22.4 t. A few specimens indicate a maximum length of 11–30% greater than average and a mass of 32.7–72.6 t. The cervical vertebrae of Apatosaurus are less elongated and more constructed than those of Diplodocus, a diplodocid like Apatosaurus, the bones of the leg are much stockier despite being longer, implying that Apatosaurus was a more robust animal; the tail was held above the ground during normal locomotion. Apatosaurus had a single claw on three on each hindlimb.
The Apatosaurus skull, long thought to be similar to Camarasaurus, is much more similar to that of Diplodocus. Apatosaurus was a generalized browser that held its head elevated. To lighten its vertebrae, Apatosaurus had air sacs. Like that of other diplodocids, its tail may have been used as a whip to create loud noises; the skull of Apatosaurus was confused with that of Camarasaurus and Brachiosaurus until 1909, when the holotype of A. louisae was found, a complete skull just a few meters away from the front of the neck. Henry Fairfield Osborn disagreed with this association, went on to mount a skeleton of Apatosaurus with a Camarasaurus skull cast; until 1970, Apatosaurus skeletons were mounted with speculative skull casts, when McIntosh showed that more robust skulls assigned to Diplodocus were more from Apatosaurus. Apatosaurus is a genus in the family Diplodocidae, it is one of the more basal genera, with only Amphicoelias and a new, unnamed genus more primitive. While the subfamily Apatosaurinae was named in 1929, the group was not used validly until an extensive 2015 study.
Only Brontosaurus is in the subfamily, with the other genera being considered synonyms or reclassified as diplodocines. Brontosaurus has long been considered a junior synonym of Apatosaurus. A 2015 study concluded that Brontosaurus is a valid genus of sauropod distinct from Apatosaurus, but not all paleontologists agree with this division; as it existed in North America during the late Jurassic, Apatosaurus would have lived alongside dinosaurs such as Allosaurus, Camarasaurus and Stegosaurus. Apatosaurus was a long-necked, quadrupedal animal with a long, whip-like tail, its forelimbs were shorter than its hindlimbs. Most size estimates are based on the type specimen of A. louisae. In 1936 this was measured to be 21.8 m, by measuring the vertebral column. Current estimates are similar, finding that the individual was 21–22.8 m long and had a mass of 16.4–22.4 t. A 2015 study that estimated the mass of volumetric models of Dreadnoughtus and Giraffatitan estimates CM 3018 at 21.8–38.2 t, similar in mass to Dreadnoughtus.
Past estimates have put the creature's mass as high as 35.0 t. Some specimens of A. ajax represent individuals 11–30% longer, suggesting masses twice that of CM 3018 or 32.7–72.6 t rivalling the largest titanosaurs. The skull is small in relation to the size of the animal; the jaws are lined with spatulate teeth suited to an herbivorous diet. The snout of Apatosaurus and similar diplodocoids is squared, with only Nigersaurus having a squarer skull; the braincase of Apatosaurus is well preserved in specimen BYU 17096, which preserved much of the skeleton. A phylogenetic analysis found that the braincase had a morphology similar to those of other diplodocoids; some skulls of Apatosaurus have been found still in articulation with their teeth. Those teeth that have the enamel surface exposed do not show any scratches on the surface. Like those of other sauropods, the neck vertebrae are bifurcated; the vertebral formula for the holotype of A. louisae is 15 cervicals, 10 dorsals, 5 sacrals, 82 caudals.
The caudal vertebra number may vary within species. The cervical vertebrae of Apatosaurus and Brontosaurus are stouter and more robust than those of other diplodocids and were found to be most similar to Camarasaurus by Charles Whitney Gilmore. In addition, they support cervical ribs that extend farther towards the ground than in diplodocines, have vertebrae and ribs that are narrower towards the top of the neck, making the neck nearly triangular in cross-section. In Apatosaurus louisae, the atlas-axis complex of the first cervicals is nearly fused; the dorsal ribs are not fused or attached to their vertebrae and are instead loosely articulated. Apatosaurus has ten dorsal ribs on either side of the body; the large neck was filled with an extensive system of weight-saving air sacs. Apatosaurus, like its close relative Supersaurus, has tall neural spines, which make up more than half the height of the individual bones of its vertebrae; the shape of the tail is unusual f
MacOS is a series of graphical operating systems developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac family of computers. Within the market of desktop and home computers, by web usage, it is the second most used desktop OS, after Microsoft Windows.macOS is the second major series of Macintosh operating systems. The first is colloquially called the "classic" Mac OS, introduced in 1984, the final release of, Mac OS 9 in 1999; the first desktop version, Mac OS X 10.0, was released in March 2001, with its first update, 10.1, arriving that year. After this, Apple began naming its releases after big cats, which lasted until OS X 10.8 Mountain Lion. Since OS X 10.9 Mavericks, releases have been named after locations in California. Apple shortened the name to "OS X" in 2012 and changed it to "macOS" in 2016, adopting the nomenclature that they were using for their other operating systems, iOS, watchOS, tvOS; the latest version is macOS Mojave, publicly released in September 2018.
Between 1999 and 2009, Apple sold. The initial version, Mac OS X Server 1.0, was released in 1999 with a user interface similar to Mac OS 8.5. After this, new versions were introduced concurrently with the desktop version of Mac OS X. Beginning with Mac OS X 10.7 Lion, the server functions were made available as a separate package on the Mac App Store.macOS is based on technologies developed between 1985 and 1997 at NeXT, a company that Apple co-founder Steve Jobs created after leaving the company. The "X" in Mac OS X and OS X is pronounced as such; the X was a prominent part of the operating system's brand identity and marketing in its early years, but receded in prominence since the release of Snow Leopard in 2009. UNIX 03 certification was achieved for the Intel version of Mac OS X 10.5 Leopard and all releases from Mac OS X 10.6 Snow Leopard up to the current version have UNIX 03 certification. MacOS shares its Unix-based core, named Darwin, many of its frameworks with iOS, tvOS and watchOS.
A modified version of Mac OS X 10.4 Tiger was used for the first-generation Apple TV. Releases of Mac OS X from 1999 to 2005 ran on the PowerPC-based Macs of that period. After Apple announced that they were switching to Intel CPUs from 2006 onwards, versions were released for 32-bit and 64-bit Intel-based Macs. Versions from Mac OS X 10.7 Lion run on 64-bit Intel CPUs, in contrast to the ARM architecture used on iOS and watchOS devices, do not support PowerPC applications. The heritage of what would become macOS had originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, launched in 1989; the kernel of NeXTSTEP is based upon the Mach kernel, developed at Carnegie Mellon University, with additional kernel layers and low-level user space code derived from parts of BSD. Its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language. Throughout the early 1990s, Apple had tried to create a "next-generation" OS to succeed its classic Mac OS through the Taligent and Gershwin projects, but all of them were abandoned.
This led Apple to purchase NeXT in 1996, allowing NeXTSTEP called OPENSTEP, to serve as the basis for Apple's next generation operating system. This purchase led to Steve Jobs returning to Apple as an interim, the permanent CEO, shepherding the transformation of the programmer-friendly OPENSTEP into a system that would be adopted by Apple's primary market of home users and creative professionals; the project was first code named "Rhapsody" and officially named Mac OS X. Mac OS X was presented as the tenth major version of Apple's operating system for Macintosh computers. Previous Macintosh operating systems were named using Arabic numerals, as with Mac OS 8 and Mac OS 9; the letter "X" in Mac OS X's name refers to a Roman numeral. It is therefore pronounced "ten" in this context. However, it is commonly pronounced like the letter "X"; the first version of Mac OS X, Mac OS X Server 1.0, was a transitional product, featuring an interface resembling the classic Mac OS, though it was not compatible with software designed for the older system.
Consumer releases of Mac OS X included more backward compatibility. Mac OS applications could be rewritten to run natively via the Carbon API; the consumer version of Mac OS X was launched in 2001 with Mac OS X 10.0. Reviews were variable, with extensive praise for its sophisticated, glossy Aqua interface but criticizing it for sluggish performance. With Apple's popularity at a low, the makers of several classic Mac applications such as FrameMaker and PageMaker declined to develop new versions of their software for Mac OS X. Ars Technica columnist John Siracusa, who reviewed every major OS X release up to 10.10, described the early releases in retrospect as'dog-slow, feature poor' and Aqua as'unbearably slow and a huge resource hog'. Apple developed several new releases of Mac OS X. Siracusa's review of version 10.3, noted "It's strange to have gone from years of uncertainty and vaporware to a steady annual supply of major new operating system releases." Version 10.4, Tiger shocked executives at Microsoft by offering a number of features, such as fast file s
Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards and light fittings in a structure. Wiring is subject to safety standards for installation. Allowable wire and cable types and sizes are specified according to the circuit operating voltage and electric current capability, with further restrictions on the environmental conditions, such as ambient temperature range, moisture levels, exposure to sunlight and chemicals. Associated circuit protection and distribution devices within a building's wiring system are subject to voltage and functional specification. Wiring safety codes vary by country or region; the International Electrotechnical Commission is attempting to harmonise wiring standards amongst member countries, but significant variations in design and installation requirements still exist. Wiring installation codes and regulations are intended to protect people and property from electrical shock and fire hazards, they are based on a model code produced by a national or international standards organisation, such as the IEC.
In Australia and New Zealand, the AS/NZS 3000 standard known as the "wiring rules", specifies requirements for the selection and installation of electrical equipment, the design and testing of such installations. The standard is mandatory in Australia. In European countries, an attempt has been made to harmonise national wiring standards in an IEC standard, IEC 60364 Electrical Installations for Buildings. Hence national standards follow an identical system of chapters. However, this standard is not written in such language that it can be adopted as a national wiring code. Neither is it designed for field use by electrical tradesmen and inspectors for testing compliance with national wiring standards. By contrast, national codes, such as the NEC or CSA C22.1 exemplify the common objectives of IEC 60364, but provide specific rules in a form that allows for guidance of those installing and inspecting electrical systems. In Germany, DKE is the organisation responsible for the promulgation of electrical standards and safety specifications.
DIN VDE 0100 is the German wiring regulations document harmonised with IEC 60364. The first electrical codes in the United States originated in New York in 1881 to regulate installations of electric lighting. Since 1897 the US National Fire Protection Association, a private non-profit association formed by insurance companies, has published the National Electrical Code. States, counties or cities include the NEC in their local building codes by reference along with local differences; the NEC is modified every three years. It is a consensus code considering suggestions from interested parties; the proposals are studied by committees of engineers, manufacturer representatives, fire fighters and other invitees. Since 1927, the Canadian Standards Association has produced the Canadian Safety Standard for Electrical Installations, the basis for provincial electrical codes; the CSA produces the Canadian Electrical Code, the 2006 edition of which references IEC 60364 and states that the code addresses the fundamental principles of electrical protection in Section 131.
The Canadian code reprints Chapter 13 of IEC 60364, but there are no numerical criteria listed in that chapter to assess the adequacy of any electrical installation. Although the US and Canadian national standards deal with the same physical phenomena and broadly similar objectives, they differ in technical detail; as part of the North American Free Trade Agreement program, US and Canadian standards are converging toward each other, in a process known as harmonisation. In the United Kingdom, wiring installations are regulated by the Institution of Engineering and Technology Requirements for Electrical Installations: IEE Wiring Regulations, BS 7671: 2008, which are harmonised with IEC 60364; the 17th edition included new sections for microgeneration and solar photovoltaic systems. The first edition was published in 1882. In 2018, the 18th edition of the wiring regulations BS7671:2018 was released and came into force in January 2019. Although BS 7671 is the standard to which the UK electrical industry adheres, compliance with BS 7671 is not a legal requirement.
In a typical electrical code, some colour-coding of wires is mandatory. Many local rules and exceptions exist per state or region. Older installations vary in colour codes, colours may fade with insulation exposure to heat and ageing; as of March 2011, the European Committee for Electrotechnical Standardization requires the use of green/yellow colour cables as protective conductors, blue as neutral conductors and brown as single-phase conductors. The United States National Electrical Code requires a bare copper, or green or green/yellow insulated protective conductor, a white or grey neutral, with any other colour used for single phase; the NEC requires the "high leg" conductor of a High-leg delta or "bastard-leg" system to have orange insulation, or to be identified by other suitable means such as tagging. Prior to the adoption of orange as the suggested colour for the high-leg in the 1971 NEC, it was common practice in some areas to use red for this purpose; the introduction of the NEC states that it is not intended to be a design manual, therefore creating a colour code for ungrounded or "hot" conductors falls outside the scope and
Microsoft Windows is a group of several graphical operating system families, all of which are developed and sold by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows Embedded. Defunct Windows families include Windows Mobile and Windows Phone. Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces. Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh. On PCs, Windows is still the most popular operating system. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones.
In 2014, the number of Windows devices sold was less than 25 %. This comparison however may not be relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows show one third market share, similar to that for end user use; as of October 2018, the most recent version of Windows for PCs, tablets and embedded devices is Windows 10. The most recent versions for server computers is Windows Server 2019. A specialized version of Windows runs on the Xbox One video game console. Microsoft, the developer of Windows, has registered several trademarks, each of which denote a family of Windows operating systems that target a specific sector of the computing industry; as of 2014, the following Windows families are being developed: Windows NT: Started as a family of operating systems with Windows NT 3.1, an operating system for server computers and workstations. It now consists of three operating system subfamilies that are released at the same time and share the same kernel: Windows: The operating system for mainstream personal computers and smartphones.
The latest version is Windows 10. The main competitor of this family is macOS by Apple for personal computers and Android for mobile devices. Windows Server: The operating system for server computers; the latest version is Windows Server 2019. Unlike its client sibling, it has adopted a strong naming scheme; the main competitor of this family is Linux. Windows PE: A lightweight version of its Windows sibling, meant to operate as a live operating system, used for installing Windows on bare-metal computers, recovery or troubleshooting purposes; the latest version is Windows PE 10. Windows IoT: Initially, Microsoft developed Windows CE as a general-purpose operating system for every device, too resource-limited to be called a full-fledged computer. However, Windows CE was renamed Windows Embedded Compact and was folded under Windows Compact trademark which consists of Windows Embedded Industry, Windows Embedded Professional, Windows Embedded Standard, Windows Embedded Handheld and Windows Embedded Automotive.
The following Windows families are no longer being developed: Windows 9x: An operating system that targeted consumers market. Discontinued because of suboptimal performance. Microsoft now caters to the consumer market with Windows NT. Windows Mobile: The predecessor to Windows Phone, it was a mobile phone operating system; the first version was called Pocket PC 2000. The last version is Windows Mobile 6.5. Windows Phone: An operating system sold only to manufacturers of smartphones; the first version was Windows Phone 7, followed by Windows Phone 8, the last version Windows Phone 8.1. It was succeeded by Windows 10 Mobile; the term Windows collectively describes any or all of several generations of Microsoft operating system products. These products are categorized as follows: The history of Windows dates back to 1981, when Microsoft started work on a program called "Interface Manager", it was announced in November 1983 under the name "Windows", but Windows 1.0 was not released until November 1985.
Windows 1.0 was to achieved little popularity. Windows 1.0 is not a complete operating system. The shell of Windows 1.0 is a program known as the MS-DOS Executive. Components included Calculator, Cardfile, Clipboard viewer, Control Panel, Paint, Reversi and Write. Windows 1.0 does not allow overlapping windows. Instead all windows are tiled. Only modal dialog boxes may appear over other windows. Microsoft sold as included Windows Development libraries with the C development environment, which included numerous windows samples. Windows 2.0 was released in December 1987, was more popular than its predecessor. It features several improvements to the user memory management. Windows 2.03 changed the OS from tiled windows to overlapping windows. The result of this change led to Apple Computer filing a suit against Microsoft alleging infringement on Apple's copyrights. Windows 2.0
Brontosaurus is a genus of gigantic quadruped sauropod dinosaurs. Although the type species, B. excelsus, had long been considered a species of the related Apatosaurus, researchers proposed in 2015 that Brontosaurus is a genus separate from Apatosaurus and that it contains three species: B. excelsus, B. yahnahpin, B. parvus. Brontosaurus had a small head adapted for a herbivorous lifestyle; the various species lived during the Late Jurassic epoch in the Morrison Formation of what is now North America, were extinct by the end of the Jurassic. Adult individuals of Brontosaurus are estimated to have weighed up to 15 tonnes and measured up to 22 metres long; as the archetypal sauropod, Brontosaurus is one of the best-known dinosaurs and has been featured in film and postage stamps, as well as many other types of media. Brontosaurus was a large, long-necked quadrupedal animal with a long, whip-like tail, forelimbs that were shorter than its hindlimbs; the largest species, B. excelsus, weighed up to 15 tonnes and measured up to 22 m long from head to tail.
For comparison, the current largest land animal, the average male African bush elephant is 3.20 m tall at the shoulder and has a body mass of 6,000 kg or 6.6 short tons. The skull of Brontosaurus hasn't been found but was similar to the skull of the related Apatosaurus. Like those of other sauropods, the vertebrae of the neck were bifurcated; the spine and tail consisted of 15 cervicals, 10 dorsals, five sacrals, 82 caudals. The caudal vertebra number was noted to vary within a species; the cervical vertebrae were stouter than other diplodocids, though not as stout as in mature specimens of Apatosaurus. The dorsal ribs are not fused or attached to their vertebrae, instead being loosely articulated. Ten dorsal ribs are on either side of the body; the large neck was filled with an extensive system of weight-saving air sacs. Brontosaurus, like its close relative Apatosaurus, had tall spines on its vertebrae, which made up more than half the height of the individual bones; the shape of the tail was unusual for diplodocids, being comparatively slender, due to the vertebral spines decreasing in height the farther they are from the hips.
Brontosaurus had long ribs compared to most other diplodocids, giving them unusually deep chests. As in other diplodocids, the last portion of the tail of Brontosaurus possessed a whip-like structure; the limb bones were very robust. The arm bones are stout, with the humerus resembling that of Camarasaurus, those of B. excelsus being nearly identical to those of Apatosaurus ajax. Charles Gilmore in 1936 noted that previous reconstructions erroneously proposed that the radius and ulna could cross, when in life they would have remained parallel. Brontosaurus had a single large claw on each forelimb, the first three toes possessed claws on each foot. By 1936, it was recognized that no sauropod had more than one hand claw preserved, this one claw is now accepted as the maximum number throughout the entire group; the single front claw bone is curved and squarely shortened on the front end. The hip bones included the fused pubes and ischia; the tibia and fibula bones of the lower leg were different from the slender bones of Diplodocus, but nearly indistinguishable from those of Camarasaurus.
The fibula is longer than the tibia, although it is more slender. In 1879, O. C. Marsh, a professor of paleontology at Yale University, announced the discovery of a large and complete sauropod skeleton from Morrison Formation rocks at Como Bluff, Wyoming, he identified it as belonging to an new genus and species, which he named Brontosaurus excelsus, meaning "thunder lizard", from the Greek brontē/βροντη meaning "thunder" and sauros/σαυρος meaning "lizard", from the Latin excelsus, "noble" or "high". By this time, the Morrison Formation had become the center of the Bone Wars, a fossil-collecting rivalry between early paleontologists Othniel Charles Marsh and Edward Drinker Cope; because of this, the publications and descriptions of taxa by Marsh and Cope were rushed at the time. Elmer Riggs, in the 1903 edition of Geological Series of the Field Columbian Museum, argued that Brontosaurus was not different enough from Apatosaurus to warrant its own genus, so he created the new combination Apatosaurus excelsus for it.
Riggs stated. As the term'Apatosaurus' has priority,'Brontosaurus' will be regarded as a synonym". Nonetheless, before the mounting of the American Museum of Natural History specimen, Henry Fairfield Osborn chose to label the skeleton "Brontosaurus", though he was a strong opponent of Marsh and his taxa. In 1905, the American Museum of Natural History unveiled the first-ever mounted skeleton of a sauropod, a composite specimen that they referred to as the species Brontosaurus excelsus; the AMNH specimen was complete, only missing the feet, lower leg, shoulder bones, tail bones. To complete the mount, the rest of the tail was fashioned to appear as Marsh believed it should, which had too few vertebrae. In addition, a sculpted model of what the museum felt the skull of this massive creature might look like was placed on the skeleton; this was not a delicate skull like that of Diplodocus, which wo