Education Fluid Mechanics Douglas Pdf


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FLUIDMECHANICS. OUGLAS. SIOREK. AFFIELD. JACK. FIFTH. EDITION. John F. Douglas. Janusz M. Gasiorek. John A. Swaffield. Lynne B. Jack. Additional. Why do you want to benefit from the labor of John F. Douglas without reimbursing him for that labor? > Jeremiah (NKJV) “Woe to him who builds his house. Tokai University, Japan, where he taught and researched fluid mechanics and Fluid mechanics has hitherto been divided into 'hydraulics', dealing with.

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It is also suitable for conversion MSc courses requiring a fundamental treatment John F. Douglas of fluid mechanics and will be a valuable resource for specialist . solving problems in fluid mechanics volume 1 by J. F. Osama M Elmardi. Loading Preview. Sorry, preview is currently unavailable. You can. PDF | solving problems in fluid mechanics volume 1 by J. F. Douglas.

Heavy water deuterium oxide , 2 H 2 O , D 2 O is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium 2 H or D, also known as heavy hydrogen , rather than the common hydrogen-1 isotope 1 H or H, also called protium that makes up most of the hydrogen in normal water. Deuterium is a hydrogen isotope with a nucleus containing a neutron and a proton ; the nucleus of a protium normal hydrogen atom consists of just a proton. The additional neutron makes a deuterium atom roughly twice as heavy as a protium atom. A molecule of heavy water has two deuterium atoms in place of the two protium atoms of ordinary "light" water. The colloquial term 'heavy water' refers to a highly enriched water mixture that contains mostly deuterium oxide D 2 O , but also some hydrogen-deuterium oxide HDO and a smaller amount of ordinary hydrogen oxide H 2 O. For comparison, ordinary water the "ordinary water" used for a deuterium standard contains only about deuterium atoms per million hydrogen atoms, meaning that 0. Heavy water is not radioactive.

There is no evidence that civilian heavy water power reactors—such as the CANDU or Atucha designs—have been used to produce military fissile materials. In nations that do not already possess nuclear weapons, nuclear material at these facilities is under IAEA safeguards to discourage any diversion. Suppliers of heavy water and heavy water production technology typically apply IAEA International Atomic Energy Agency administered safeguards and material accounting to heavy water.

SNO was built to answer the question of whether or not electron-type neutrinos produced by fusion in the Sun the only type the Sun should be producing directly, according to theory might be able to turn into other types of neutrinos on the way to Earth.

SNO detects the Cherenkov radiation in the water from high-energy electrons produced from electron-type neutrinos as they undergo charged current CC interactions with neutrons in deuterium , turning them into protons and electrons however, only the electrons are fast enough to produce Cherenkov radiation for detection. The first of these two reactions is produced only by electron-type neutrinos, while the second can be caused by all of the neutrino flavors.

The use of deuterium is critical to the SNO function, because all three "flavours" types of neutrinos [78] may be detected in a third type of reaction as well, neutrino-disintegration, in which a neutrino of any type electron, muon, or tau scatters from a deuterium nucleus deuteron , transferring enough energy to break up the loosely bound deuteron into a free neutron and proton via a neutral current NC interaction. Heavy water is employed as part of a mixture with H 2 18 O for a common and safe test of mean metabolic rate in humans and animals undergoing their normal activities.

Tritium is the active substance in self-powered lighting and controlled nuclear fusion, its other uses including autoradiography and radioactive labeling. It is also used in nuclear weapon design for boosted fission weapons and initiators. Some tritium is created in heavy water moderated reactors when deuterium captures a neutron.

This reaction has a small cross-section probability of a single neutron-capture event and produces only small amounts of tritium, although enough to justify cleaning tritium from the moderator every few years to reduce the environmental risk of tritium escape. Producing a lot of tritium in this way would require reactors with very high neutron fluxes, or with a very high proportion of heavy water to nuclear fuel and very low neutron absorption by other reactor material.

The tritium would then have to be recovered by isotope separation from a much larger quantity of deuterium, unlike production from lithium-6 the present method , where only chemical separation is needed.

Deuterium's absorption cross section for thermal neutrons is 0. Also, 17 O may emit an alpha particle on neutron capture, producing radioactive carbon From Wikipedia, the free encyclopedia. Not to be confused with hard water or tritiated water. Deuterium oxide [1] Water- d 2 [2] Dideuterium monoxide. CAS Number. Interactive image. Gmelin Reference. PubChem CID. Chemical formula.

Solubility in water. Refractive index n D. Dipole moment. This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. February Learn how and when to remove this template message. Main article: Norwegian heavy water sabotage. Doubly labeled water test.

See also: Water portal. December Journal of Cellular and Comparative Physiology. January The Journal of Physical Chemistry.

Bird flight

Cambridge UK: Electronic version. Online corrected version: Kushner; Alison Baker; T. Dunstall Columbia University. Retrieved Archived from the original PDF on 22 April Retrieved 25 August CS1 maint: V, Ignatov, I. Problems and Decisions, Moscow, No. Chemistry and Chemical Reactivity, Volume 1 7th ed. Cengage Learning. Retrieved 21 January Popular Science. Archived from the original on 16 December Retrieved 14 August Urey; Ferdinand G.

Brickwedde; G. Murphy Physical Review. The Journal of Chemical Physics. Bratu, E. Abel, O. Journal of Medicine, Physiology and Biophysics. July Chemical and biological studies with deuterium. V; Ignatov, I. Influence of Deuterium-depleted water on Cultured Cell Growth".

Rom J. Ignatov, I. Pure Appl. Bioorganic Chemistry. I, Skladnev, D. Chemistry and Ecology , No.

Biotechnology , pp. D2O is more toxic to malignant than normal animal cells Deuterium Isotope Effects in Chemistry and Biology". Annals of the New York Academy of Sciences. News and Views. Microbial Growth on C1 Compounds, in: Kluwer Academic Publishers, pp.

Stable Isotope Geochemistry 4 ed. The American Journal of Clinical Nutrition. Archived from the original on 10 July Retrieved 10 September Philadelphia Daily News. Retrieved 30 November University of British Columbia. Retrieved 19 March Sulzer Technical Review. Energia Nuclear Buenos Aires: An original project in the Argentine.. Espionage and the Manhattan Project, ". May History of One Priority.

Part 3 PDF Report. Karpov Institute of Physical Chemistry. Retrieved March 21, — via International periodic scientific journal SWorld. The Nonproliferation Review. Retrieved 24 March Assault In Norway: Sabotaging the Nazi Nuclear Program. Guilford, Connecticut: The Lyons Press. NOVA Web site. Retrieved 8 October International Herald Tribune , , p. Retrieved from Wisconsinproject. Foreign Policy United States Department of Energy. The original design production was lbs.

Maximum production was lbs. Canadian Nuclear Safety Commission. March https: Retrieved 21 February Separation of Hydrogen Isotopes. ACS Symposium Series. October Archived from the original on 13 July AP News.

Retrieved 21 October March 8, ". The Washington Post. The Observatory of Economic Complexity. Archived from the original on 21 October Outline Data Model Properties. Liquid Ice Vapor Steam. Deuterium-depleted Semiheavy Heavy Tritiated Hydronium. Molecules detected in outer space. Aluminium monochloride Aluminium monofluoride Aluminium monoxide Argonium Carbon monophosphide Carbon monosulfide Carbon monoxide Carborundum Cyanogen radical Diatomic carbon Fluoromethylidynium Hydrogen chloride Hydrogen fluoride Hydrogen molecular Hydroxyl radical Iron II oxide Magnesium monohydride cation Methylidyne radical Nitric oxide Nitrogen molecular Nitrogen monohydride Nitrogen sulfide Oxygen molecular Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon mononitride Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfur monohydride Sulfur monoxide Titanium oxide.

Astrochemistry Portal: Oxygen compounds. Binary compounds of hydrogen. Lithium hydride, LiH ionic metal hydride Beryllium hydride Left gas phase: BeH 2 covalent metal hydride Right: BeH 2 n solid phase polymeric metal hydride Borane and diborane Left: BH 3 special conditions , covalent metalloid hydride Right: PbH 4.

SbH 3. BiH 3. HN 3 NH radical. PoH 2. Retrieved from " https: Deuterated solvents Forms of water Neutron moderators Nuclear reactor coolants Oxygen compounds. Hidden categories: Archived copy as title CS1: Namespaces Article Talk. Views Read Edit View history. In other projects Wikimedia Commons. This page was last edited on 14 April , at The wing sometimes has vestigial claws.

In most species these are lost by the time the bird is adult such as the highly visible ones used for active climbing by hoatzin chicks , but claws are retained into adulthood by the secretarybird , screamers , finfoots , ostriches, several swifts and numerous others, as a local trait, in a few specimens. Albatrosses have locking mechanisms in the wing joints that reduce the strain on the muscles during soaring flight. Even within a species wing morphology may differ. Female birds exposed to predators during ovulation produce chicks that grow their wings faster than chicks produced by predator-free females.

Their wings are also longer. Both adaptations may make them better at avoiding avian predators. The shape of the wing is important in determining the flight capabilities of a bird.

Different shapes correspond to different trade-offs between advantages such as speed, low energy use, and maneuverability. Two important parameters are the aspect ratio and wing loading.

Bird flight - Wikipedia

Aspect ratio is the ratio of wingspan to the mean of its chord or the square of the wingspan divided by wing area. Wing loading is the ratio of weight to wing area. Most kinds of bird wing can be grouped into four types, with some falling between two of these types. These types of wings are elliptical wings, high speed wings, high aspect ratio wings and soaring wings with slots.

Technically, elliptical wings are those having elliptical that is quarter ellipses meeting conformally at the tips. The early model Supermarine Sptifire is an example.

Some birds have vaguely elliptical wings, including the albatross wing of high aspect ratio. Although the term is convenient, it might be more precise to refer to curving taper with fairly small radius at the tips. Many small birds have having a low aspect ratio with elliptical character when spread , allowing for tight maneuvering in confined spaces such as might be found in dense vegetation.

As such they are common in forest raptors such as Accipiter hawks , and many passerines , particularly non-migratory ones migratory species have longer wings.

They are also common in species that use a rapid take off to evade predators, such as pheasants and partridges. High speed wings are short, pointed wings that when combined with a heavy wing loading and rapid wingbeats provide an energetically expensive, but high speed. This type of flight is used by the bird with the fastest wing speed, the peregrine falcon , as well as by most of the ducks.

The same wing shape is used by the auks for a different purpose; auks use their wings to "fly" underwater. High aspect ratio wings, which usually have low wing loading and are far longer than they are wide, are used for slower flight. This may take the form of almost hovering as used by kestrels , terns and nightjars or in soaring and gliding flight, particularly the dynamic soaring used by seabirds , which takes advantage of wind speed variation at different altitudes wind shear above ocean waves to provide lift.

Low speed flight is also important for birds that plunge-dive for fish. These wings are favored by larger species of inland birds, such as eagles , vultures , pelicans , and storks. The slots at the end of the wings, between the primaries, reduce the induced drag and wingtip vortices by "capturing" the energy in air flowing from the lower to upper wing surface at the tips, [7] whilst the shorter size of the wings aids in takeoff high aspect ratio wings require a long taxi to get airborne.

When in gliding flight , the upward aerodynamic force is equal to the weight. In gliding flight, no propulsion is used; the energy to counteract the energy loss due to aerodynamic drag is either taken from the potential energy of the bird, resulting in a descending flight, or is replaced by rising air currents " thermals " , referred to as soaring flight. For specialist soaring birds obligate soarers , the decision to engage in flight are strongly related to atmospheric conditions that allow individuals to maximise flight-efficiency and minimise energetic costs.

When a bird flaps, as opposed to gliding, its wings continue to develop lift as before, but the lift is rotated forward to provide thrust , which counteracts drag and increases its speed, which has the effect of also increasing lift to counteract its weight , allowing it to maintain height or to climb.

Flapping involves two stages: At each up-stroke the wing is slightly folded inwards to reduce the energetic cost of flapping-wing flight. Small birds often fly long distances using a technique in which short bursts of flapping are alternated with intervals in which the wings are folded against the body. This is a flight pattern known as "bounding" or "flap-bounding" flight.

Several bird species use hovering, with one family specialized for hovering — the hummingbirds. Although not a true hover, some birds remain in a fixed position relative to the ground or water by flying into a headwind. Hummingbirds, [16] [17] kestrels , terns and hawks use this wind hovering. Most birds that hover have high aspect ratio wings that are suited to low speed flying.

Hummingbirds are a unique exception — the most accomplished hoverers of all birds. Take-off is one of the most energetically demanding aspects of flight, as the bird must generate enough airflow across the wing to create lift. Small birds do this with a simple upward jump. That doesn't work for larger birds, which must take a run up to generate sufficient airflow.

Large birds take off by facing into the wind, or, if they can, by perching on a branch or cliff so they can just drop off into the air. Landing is also a problem for large birds with high wing loads. This problem is dealt with in some species by aiming for a point below the intended landing area such as a nest on a cliff then pulling up beforehand.

If timed correctly, the airspeed once the target is reached is virtually nil. Landing on water is simpler, and the larger waterfowl species prefer to do so whenever possible, landing into wind and using their feet as skids. To lose height rapidly prior to landing, some large birds such as geese indulge in a rapid alternating series of sideslips or even briefly turning upside down in a maneuver termed as whiffling.

A wide variety of birds fly together in a symmetric V-shaped or a J-shaped coordinated formation, also referred to as an "echelon", especially during long distance flight or migration. It is often assumed that birds resort to this pattern of formation flying in order to save energy and improve the aerodynamic efficiency.

The wingtips of the leading bird in an echelon create a pair of opposite rotating line vortices. The vortices trailing a bird have an underwash part behind the bird, and at the same time they have an upwash on the outside, that hypothetically could aid the flight of a trailing bird. Studies of waldrapp ibis show that birds spatially coordinate the phase of wing flapping and show wingtip path coherence when flying in V positions, thus enabling them to maximally utilise the available energy of upwash over the entire flap cycle.

In contrast, birds flying in a stream immediately behind another do not have wingtip coherence in their flight pattern and their flapping is out of phase, as compared to birds flying in V patterns, so as to avoid the detrimental effects of the downwash due to the leading bird's flight.

The most obvious adaptation to flight is the wing, but because flight is so energetically demanding birds have evolved several other adaptations to improve efficiency when flying. Birds' bodies are streamlined to help overcome air-resistance.

Also, the bird skeleton is hollow to reduce weight, and many unnecessary bones have been lost such as the bony tail of the early bird Archaeopteryx , along with the toothed jaw of early birds, which has been replaced with a lightweight beak.

The skeleton's breastbone has also adapted into a large keel, suitable for the attachment of large, powerful flight muscles. The vanes of each feather have hooklets called barbules that zip the vanes of individual feathers together, giving the feathers the strength needed to hold the airfoil these are often lost in flightless birds. The barbules maintain the shape and function of the feather. Each feather has a major greater side and a minor lesser side, meaning that the shaft or rachis does not run down the center of the feather.

Rather it runs longitudinally of center with the lesser or minor side to the front and the greater or major side to the rear of the feather. This feather anatomy, during flight and flapping of the wings, causes a rotation of the feather in its follicle.

The rotation occurs in the up motion of the wing. The greater side points down, letting air slip through the wing. This essentially breaks the integrity of the wing, allowing for a much easier movement in the up direction.

The integrity of the wing is reestablished in the down movement, which allows for part of the lift inherent in bird wings. This function is most important in taking off or achieving lift at very low or slow speeds where the bird is reaching up and grabbing air and pulling itself up. At high speeds the air foil function of the wing provides most of the lift needed to stay in flight. The large amounts of energy required for flight have led to the evolution of a unidirectional pulmonary system to provide the large quantities of oxygen required for their high respiratory rates.

This high metabolic rate produces large quantities of radicals in the cells that can damage DNA and lead to tumours. Birds, however, do not suffer from an otherwise expected shortened lifespan as their cells have evolved a more efficient antioxidant system than those found in other animals. Most paleontologists agree that birds evolved from small theropod dinosaurs , but the origin of bird flight is one of the oldest and most hotly contested debates in paleontology.

There has also been debate about whether the earliest known bird, Archaeopteryx , could fly. It appears that Archaeopteryx had the brain structures and inner-ear balance sensors that birds use to control their flight.

But Archaeopteryx lacked the shoulder mechanism by which modern birds' wings produce swift, powerful upstrokes; this may mean that it and other early birds were incapable of flapping flight and could only glide.

In March , scientists reported that Archaeopteryx was likely capable of flight, but in a manner substantially different from that of modern birds.

This was the earliest hypothesis, encouraged by the examples of gliding vertebrates such as flying squirrels. It suggests that proto-birds like Archaeopteryx used their claws to clamber up trees and glided off from the tops. Some recent research undermines the "trees down" hypothesis by suggesting that the earliest birds and their immediate ancestors did not climb trees. Modern birds that forage in trees have much more curved toe-claws than those that forage on the ground.

The toe-claws of Mesozoic birds and of closely related non-avian theropod dinosaurs are like those of modern ground-foraging birds. Feathers are very common in coelurosaurid dinosaurs including the early tyrannosauroid Dilong. The most common version of the "from the ground up" hypothesis argues that bird's ancestors were small ground-running predators rather like roadrunners that used their forelimbs for balance while pursuing prey and that the forelimbs and feathers later evolved in ways that provided gliding and then powered flight.

Most recent attacks on the "from the ground up" hypothesis attempt to refute its assumption that birds are modified coelurosaurid dinosaurs. The strongest attacks are based on embryological analyses , which conclude that birds' wings are formed from digits 2, 3 and 4 corresponding to the index, middle and ring fingers in humans; the first of a bird's 3 digits forms the alula , which they use to avoid stalling on low-speed flight, for example when landing ; but the hands of coelurosaurs are formed by digits 1, 2 and 3 thumb and first 2 fingers in humans.

Heavy water

The wing-assisted incline running WAIR hypothesis was prompted by observation of young chukar chicks, and proposes that wings developed their aerodynamic functions as a result of the need to run quickly up very steep slopes such as tree trunks, for example to escape from predators.

Note that in this scenario birds need downforce to give their feet increased grip. The proavis theory was first proposed by Garner, Taylor, and Thomas in We propose that birds evolved from predators that specialized in ambush from elevated sites, using their raptorial hindlimbs in a leaping attack. Drag—based, and later lift-based, mechanisms evolved under selection for improved control of body position and locomotion during the aerial part of the attack.

Selection for enhanced lift-based control led to improved lift coefficients, incidentally turning a pounce into a swoop as lift production increased. Selection for greater swooping range would finally lead to the origin of true flight. Birds use flight to obtain prey on the wing, for foraging , to commute to feeding grounds, and to migrate between the seasons.

It is also used by some species to display during the breeding season and to reach safe isolated places for nesting. Flight is more energetically expensive in larger birds, and many of the largest species fly by soaring and gliding without flapping their wings as much as possible. Many physiological adaptations have evolved that make flight more efficient. Birds that settle on isolated oceanic islands that lack ground-based predators often lose the ability to fly.

This illustrates both flight's importance in avoiding predators and its extreme demand for energy. From Wikipedia, the free encyclopedia. This section may require cleanup to meet Wikipedia's quality standards. The specific problem is: September Learn how and when to remove this template message.

See also: Bird landings. Main article: Origin of avian flight. Birds portal. Retrieved Unfixed gears and body lift". Nomina Anatomica Avium. Nuttall Ornithological Club.

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