101 Sentences With "biconvex" | Random Sentence Generator

See-through spheres act like biconvex lens, where the two opposite roundest sides of the bag become the two lenses.

The other is Google Cardboard: a nifty kit that sells for $15 and that holds a smartphone in place in front of biconvex lenses.

Growth lines biconvex with prominent ventrolateral projections and a deep ventral sinus.

Micrograph of a cholesterol embolus showing the characteristic cholesterol clefts (biconvex white spaces) and a giant cell reaction. Kidney biopsy. H&E; stain.

The fruit is an oval, slightly biconvex box. Flowering is in April–May. It is an insect- pollinating plant and propagates by seeds.

Burgess, Daniel S. (2001). Brittle Star Features Calcite Lenses, Photonics Spectra In other compound eyes and camera eyes, the material is crystallin. A gap between tissue layers naturally forms a biconvex shape, which is optically and mechanically ideal for substances of normal refractive index. A biconvex lens confers not only optical resolution, but aperture and low-light ability, as resolution is now decoupled from hole size – which slowly increases again, free from the circulatory constraints.

Growth lines are strongly biconvex in juvenile stages, later with shallow a lateral sinus. Phoenixites may have contained the ancestor of Falcitornoceras which likely gave rise to Gundolficeras, all members of the Falcitornoceratinae.

Anostoma octodentatum shells. The shell of this species is biconvex. The height of the shell is half or nearly half of the greatest diameter. The shell is solid, and obtusely angular at the periphery.

Traditional Archery from Six Continents: The Charles E. Grayson Collection. University of Missouri Press 2007. p=1 The Holmegaard bows are made of elm and have flat arms and a D-shaped midsection. The center section is biconvex.

The shells are generally biconvex, with equal valves round in outline, and slightly longer than wide. Their size varies from medium to large. The external ligament lacks transverse striations. These clams are a facultatively mobile infaunal suspension feeders.

Crassostrea ingens is a giant fossil oyster. It has a shell reaching a height of to over . This shell is biconvex. The left valve is thick and deep, with inflation of to over ; interior cavity depth to over .

When divided horizontally, it exhibits, to some extent, the appearance of a biconvex lens, while a coronal section of its central part presents a somewhat triangular outline. It is shorter than the caudate nucleus and does not extend as far forward.

Terebratula species have biconvex egg-shaped shells, anterior margins of the valves have two small folds, concentric growth lines are quite thin or nearly absent. The larger valve has a ventral umbo with the opening through which they extend a short peduncle.

Species within this genus have a very large shells, reaching a height of about and a length of about . The shell is thick and biconvex. The left valve is slightly more convex than the right one. The radial ribs are wide, but very shallow.

An aspheric biconvex lens. Cylindrical lenses have curvature along only one axis. They are used to focus light into a line, or to convert the elliptical light from a laser diode into a round beam. They are also used in motion picture anamorphic lenses.

Extensions of convex optimization include the optimization of biconvex, pseudo-convex, and quasiconvex functions. Extensions of the theory of convex analysis and iterative methods for approximately solving non-convex minimization problems occur in the field of generalized convexity, also known as abstract convex analysis.

The pods are straight sided or slightly biconvex with a length of and a width of with longitudinal nerves. The dark brown seeds inside are arranged longitudinally or slightly obliquely and have an oblong to elliptic shape with a length of with a narrowly conical aril.

The branchlets are puberulous to hirsutellous with long stipules. The inflorescences are simple with one per axil. The peduncles are long, the heads are globular containing 23 to 25 flowers that are pale yellow to cream in colour. Seed pods are biconvex and shallowly constricted between seeds.

The robust grass-like sedge is rhizomatous and perennial, it typically grows to a height of and a width of . It blooms between August and March producing brown flowers. It has rigid, terete and biconvex culms that are smooth and glabrous. The culms are in length and in diameter.

The series of distal caudal vertebrae NHMUK R1967, once referred to Cetiosauriscus, is similar to the caudals of Diplodocus, with two convex ends (biconvex) and a long and thin centrum. These caudals display signs of injury at two points along the series of ten vertebrae, where there are signs of breakage that was later healed. These lesions were identified as the same form of pathologies as found on the tail of Diplodocus. It has been suggested that the biconvex distal caudal vertebrae in sauropods were used for making whip-like cracking noise, being thin and delicate and not intended for impact, as the joints would be very vulnerable to damage rendering them useless.

The flowers are on pale green cylindrical spikelets cylindrical that are wider than the stem. The spikelets are long and with firm glumes. After flowering biconvex light brown to grey coloured nuts form that are ribbed on the margins with an obovate to broadly obovate shape that are s in length.

The simple inflorescences simple occur singly in the axils and have spherical flower-heads containing 25 to 35 golden coloured flowers. The linear brown seed pods that form after flowering are shallowly constricted between the seeds and a biconvex shape with a length of up to and a width of around .

Conversely, in the Cryptodira, the neck bones are wide and flat. The biconvex centra in some of the cryptodiran cervicals allow the neck to fold onto itself in the vertical plane. Pleurodirans also differ from cryptodirans in the emarginations of their skulls. Skull emargination provides room and anchorage for the jaw muscles.

The shell of Branneroceras is typically marrow, evolute, with a wide or moderately wide umbilicus. Coiling maybe slightly irregular. The surface has a crenulate appearance produced by biconvex growth lines crossed by fine longitudinal, wirelike, lirae. Ribs extend Laterally from the umbilical shoulder onto the lateral flanks and persist to full maturity.

The inflorescence is found at the tip of the spike and is composed of narrow-ovoid to narrow-cylindrical spikelets with a length of . It will later form a shiny yellow to brown coloured nut with a plano-convex to biconvex, broad-obovoid shape that is around in length with a diameter of .

Global Biodiversity Information Facility The biconvex shell was typically 2.5 cm long, but sometimes grew to 4 cm. The shell of Mucrospirifer has a fold, sulcus and costae. It is greatly elongated along the hinge line, which extends outward to form sharp points. This gives them a fin- or wing-like appearance.

Craniida and Lingulida include living brachiopods, but are inarticulates. The name, Terebratula, may be derived from the Latin "terebra", meaning "hole-borer". The perceived resemblance of terebratulid shells to ancient Roman oil lamps gave the brachiopods their common name "lamp shell". Terebratulids typically have biconvex shells that are usually ovoid to circular in outline.

Posttornoceras, type genus of the Posttornoceratinae was named by Wedekind in 1910. Posttornocerashas a subglobular to discoidal shell with a small, closed umbilicus and biconvex growth lines (Miller et al. 1964). Sutural lobes next to the ventral lobe are formed adventitiously in the first latera saddles. Posttornoceras is derived from Exotornoceras (Saunders et al.

It is a tufted perennial sedge, with erect, biconvex culms, growing to 1–2 m in height. The smooth leaves are mostly basal, 1–1.8 m long and 2–3 cm wide. The inflorescence is much branched and 10–20 cm in length. The fruits are narrowly ellipsoidal-trigonous brown nuts, 2 mm long.

Karger Gazette 64: "The Eye in Focus". The gap between tissue layers naturally formed a biconvex shape, an optimally ideal structure for a normal refractive index. Independently, a transparent layer and a nontransparent layer split forward from the lens: the cornea and iris. Separation of the forward layer again formed a humour, the aqueous humour.

Typically one valve, often the brachial valve, is flatter than the other. The interior structure of the brachial valves are usually simple. In shape they are sub-circular to elliptical, with typically biconvex valves. There is some debate over the forms that first appeared of this order as to how they should be classified.

Luwian has been deduced as one of the likely candidates for the language spoken by the Trojans.Watkins 1994; Watkins 1995:144–51; Melchert 2003, pp. 265-70 with ref. After the 1995 finding of a Luwian biconvex seal at Troy VII, there has been a heated discussion over the language that was spoken in Homeric Troy.

Frenulina is an extant genus of brachiopods, known from shallow waters in the warmer parts of the Pacific and Indian Oceans. Its shell is biconvex, rounded pentagonal in profile, and dependent on the species scarlet with creamy white radiating stripes of quickly varying width, beige or seldomly entirely white. It lives attached by a stalk to a hard underground.

The linear and biconvex seed pods that form after flowering are shallowly curved and have a length up to around and a width of . The thinly coriaceous-crustaceous seed pods are glabrous to moderately hairy with longitudinally arranged seeds inside. The mottled seeds have an oblong shape with a length of and a terminal conical shaped aril.

Bisatoceras is a late Paleozoic (Upper Mississippian - Upper Pennsylvanian) Ammonoidea, a member of the goniatitid family Bisatoceratidae. Bisatoceras was named by Miller and Owen in 1937 and has a subdiscoidal shell with a very narrow or closed umbilicus. Whorl height exceeds with at maturity, immature growth stages are globular. Growth lines are usually biconvex, forming ventral and lateral sinuses.

Gigantopecten latissimus has a shell reaching a height of about and a length of about . This shell is thick and biconvex. The left valve is slightly more convex than the right one. The outer surface of the right valve has six shallow radial ribs that are rectangular in cross- section, while the left valve shows five radial ribs on the external surface.

Tornoceratidae is a family of goniatitid ammonoids from the middle and upper Devonian. The family is included in the suborder Tornoceratina and the superfamily Tornoceratoidea. Tornoceratids are subdiscoidal goniatitids with biconvex growth lines and sutures that form 6 to 10 lobes, the ventral one undivided, the lateral ones originating as subdivisions of external and internal lateral saddle. They are derived from the Anarcestida.

The Rhynchonellata is a class of Lower Cambrian to Recent articulate brachiopods that combines orders from within the Rhynchonelliformea (Articulata revised) with well developed pedicle attachment. Shell forms vary from those with wide hinge lines to beaked forms with virtually no hinge line and from generally smooth to strongly plicate. Most all are biconvex. Lophophores vary and include both looped and spiraled forms.

The rudimentary inflorescences rudimentary occur in pairs and have axes to a length of . The spherical flower-heads have a diameter of and contain 16 to 21 light golden flowers. The linear, biconvex, blackish seed pods that form after flowering are strongly curved or form a single coil. The pods have a length of up to around and have a width of around .

Amphistegina is a genus of foraminiferal protistsShort Treatise on Foraminiferology included in the Rotaliida with a stritigraphic range extending from the Eocene to recent and a cosmopolitan distribution. The test is an asymmetrically biconvex trochospiral that may be bi-involute or partially evolute on the spiral side. Chambers are numerous, broad. and low, strongly curved back at the periphery to form chamber prolongations.

Athyris is a brachiopod genus with a subequally biconvex shell that is generally wider than long and a range that extends from the Silurian into the Triassic. Athyris is the type genus for the Athyrididae, which belongs to the articulate order Athyridida. R.C. Moore (1952) gives a shorter range, from the Mid Devonian to the Lower Mississippian. Alverezites, Bruntonites, and Meristospira are among related genera.

The shape may be described as lenticular—like a biconvex lens—and depending on the species, may range in color from whitish to grayish to black. The interior chamber of the peridiole contains a hymenium that is made of basidia, sterile (non- reproductive) structures, and spores. In young, freshly opened fruit bodies, the peridioles lie in a clear gelatinous substance which soon dries.Brodie (1975), p. 6.

The shell is typically impunctate, biconvex, and oval or subcircular in shape. They are like other inarticulates in that, as with the lingulids, the shell has no hinge, at least in the earliest examples. It is thought they may have used a hydraulic mechanism. However they later seem to develop a primitive articulation, in which some used a levator mechanism for opening the shell.

The flowers have one stamen with an anther 2 -3 mm long. The style is bifid, with a sparse fringe of hairs above, while at the base there is a whorl of long whitish hairs closely pressed to the nut and partially covering it. The nut is biconvex, straw-coloured and shining. It flowers from spring to summer and typically grows in moist places.

Thalassoceratoidea, formerly Thalassocerataceae, is a superfamily of Late Paleozoic ammonites characterized by their thick-discoidal to subglobular, involute shells with narrow or closed umbilici and biconvex growth striae with ventral sinuses. The ventral lobe of the suture, which straddles the outer rim, is wide, and bifid, with a tall median saddle. Thallassoceratoidea are gonitites and one of seventeen superfamilies in the Goniatitina suborder. Two families are now included, Bisatoceratidae and Thalassoceratidae.

The vertebra features a biconvex centrum, a feature shared with other titanosaurs. Von Huene noted that the first caudal could possibly belong to Laplatasaurus. With the exception of an incomplete cervical vertebra and the questionable first caudal, there are no vertebrae that link the skull to the limb material. There is a lack of field documentation to aid in the referral of all the material to one individual.

ELP correlates with the placement of the IOL inside the eye, whether it is in the anterior chamber in the sulcus or in the capsular bag. It also varies with the implant’s configuration and the location of its optical center. For example, the use of a meniscus lens calls for a smaller ELP value than a biconvex IOL. IOL calculation formulas differ in the way they calculate ELP.

These eyes are characterized by close packing of biconvex lenses beneath a single corneal layer that covers all of the lenses. Each lens is generally hexagonal in outline and in direct contact with the others. They range in number from one to more than 15,000 per eye. Eyes are usually large, and because the individual lenses are hard to make out, they look smooth and sometimes bead-like.

There are many types of dialyte camera lenses. One type is a symmetrical design consisting of four air spaced lenses: the outer pair is biconvex and the inner pair is biconcave. The symmetrical structure provides good correction for many aberrations. The Aviar type of lens (Taylor Hobson) is similar but is considered to have a different origin, from the splitting of the central biconcave element of the Cooke triplet.

An aspheric biconvex lens. An aspheric lens or asphere (often labeled ASPH on eye pieces) is a lens whose surface profiles are not portions of a sphere or cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens. The asphere's more complex surface profile can reduce or eliminate spherical aberration and also reduce other optical aberrations such as astigmatism, compared to a simple lens.

The Phantom was a single-seat, clean, high-performance glider designed for Mr Percy Michelson with distance records and a cross-channel flight in mind. It was an all-wood aircraft, built of spruce and plywood. The wing had a single spruce spar with stressed ply to the leading edge forming a torsion box. At the time, the choice of the biconvex R.A.F. 34 airfoil was unusual, the concave/convex Göttingen forms being generally used.

Discorbis is a genus of benthic Foraminfera (Kingdom Protista in paleontological classifications), that made its first appearance during the Eocene. Its present distribution is cosmopolitan. Discorbis produces a smooth plano-convex to unequally biconvex trochospiral test (shell) with a flattened umbilical side, taking up about two and a half whorls, with seven to ten chambers in the final whorl. The test wall is calcareous, thin, optically radial, and finely to coarsely perforate.

The shell grows to a length of 5 mm, its diameter 9 mm. The shell is much depressed, biconvex, obtusely carinate peripherally and openly umbilicate. Its color is flesh- tinted, with a band below the suture composed of fine obliquely radial dark red lines alternating with white ones. This is followed in the middle of the upper surface by a spiral series of oblique, oblong red blotches alternating with opaque white ones.

The lens has an ellipsoid, biconvex shape. The anterior surface is less curved than the posterior. In the adult, the lens is typically circa 10 mm in diameter and has an axial length of about 4 mm, though it is important to note that the size and shape can change due to accommodation and because the lens continues to grow throughout a person's lifetime.John Forrester, Andrew Dick, Paul McMenamin, William Lee (1996).

The Plasmat further refines the Dagor form by uncementing the meniscus, allowing for placement away from the first two elements and removing the criterion of symmetry. In its most basic form, it is symmetrical and consists of two cemented groups of three lenses each. The innermost element in each group is a positive meniscus, the outermost is biconvex, and there is a biconcave element between them. The Plasmat lens is made in many variants, e.g.

All rhynchonellids are biconvex (have a bulbous shell), and have a fold located in the brachial valve. This means that the commissure, the line between the two valves or shells, is zigzagged, a distinguishing characteristic of this group. The prominent beak of the pedicle valve usually overlaps that of the brachial valve, in order to allow the shell to open and close. There is usually a functional pedicle although the delthyrium may be partially closed.

The excavation recovered 87 tablets and fragments—mostly from pre-Sargonic times—biconvex, and unbaked. In 1973, a three-day surface survey of the site was conducted by Harriet P. Martin. Consisting mainly of pottery shard collection, the survey confirmed that Shuruppak dates at least as early as the Jemdet Nasr period, expanded greatly in the Early Dynastic period, and was also an element of the Akkadian Empire and the Third Dynasty of Ur.

The idea is based on modulating a part of a monochromatic light wave with a discontinuous nonlinear frequency chirp so that two opposite accelerating caustics are created in space–time as the different frequency components propagate at different group velocities in the dispersive medium. Due to the structure of the frequency chirp, the expansion and contraction of the time gap happen continuously in the same medium thus creating a biconvex time gap that conceals the enclosed events.

Unlike in schizochroal eyes, adjacent lenses were in direct contact with one another. Lens shape generally depended on cuticle thickness. The lenses of trilobites with thin cuticles were thin and biconvex, whereas those with thick cuticles had thick lenses, which in extreme cases, could be thick columns with the outer surface flattened and the inner surface hemispherical. Regardless of lens thickness, however, the point at which light was focused was roughly the same distance below the lens.

The different methods of bending the neck require completely different anatomies of the cervical vertebrae. All extant turtles studied so far have eight vertebrae in the neck. In the Pleurodira, these vertebrae are narrow in cross-section and spool-shaped with biconvex centra on one or more of the cervicals. These centra act as a double joint, allowing a large degree of sideways movement and providing a means of folding the neck onto itself in the lateral plane.

In the mathematical field of graph theory, a convex bipartite graph is a bipartite graph with specific properties. A bipartite graph, (U ∪ V, E), is said to be convex over the vertex set U if U can be enumerated such that for all v ∈ V the vertices adjacent to v are consecutive. Convexity over V is defined analogously. A bipartite graph (U ∪ V, E) that is convex over both U and V is said to be biconvex or doubly convex.

This fungus is inedible. ;Peridiole structure Peridioles contain glebal tissue, basidia, and basidiospores, surrounded by a hardened wall. They are commonly lenticular in shape (like a biconvex lens), measuring 1-3 mm in diameter. The color of the peridioles is characteristic of the genera: Cyathus has black peridioles, Nidularia and Nidula have brown peridioles, Mycocalia has yellow- to red-brown peridioles, and Crucibulum has black peridioles that are surrounded by a whitish membrane called the tunica, which makes them appear white.

Argyrotheca is fastened by a very short and thick stalk. The shell is biconvex with two high and wide ribs radiating close to the midline (a shell-shape called strangulate) and four radiating ribs of declining height and width further lateral (a shell-shape called oppositely multiplicate), smooth or more commonly multiplicate. The inner surface of the shell has many rather coarse pits (or punctae). The larger valve (pedicle valve or ventral valve) has a fairly short stump beak (or subtruncate).

Most sauropods have between forty and fifty caudal vertebrae, but in diplodocids this number jumps to eighty or more. In addition, the most distal vertebrae develop a biconvex shape and together form a long, bony rod at the end of the tail, often referred to as a “whiplash tail.” Increased caudal count and a whiplash tail may be features shared by all members of the Diplodocoid group, but, due to a scarcity of evidence, this has yet to be proven.

After the poor performance and crash of the Blériot 73, Touillet developed a heavy bomber come airliner with a large rounded biconvex fuselage sitting above the lower wing. The wings were virtually identical with those of the Blériot 73, again with four Hispano- Suiza 8Fb engines grouped around the fuselage. Flight testing at Villacoubly was abruptly terminated on 22 January 1920 when oscillations in the tail unit resulted in structural failure and the fatal crash of the sole Blériot 74: One prototype built.

The angle between the two curves at P is defined as the angle between the tangents A and B at P. The angle between a line and a curve (mixed angle) or between two intersecting curves (curvilinear angle) is defined to be the angle between the tangents at the point of intersection. Various names (now rarely, if ever, used) have been given to particular cases:—amphicyrtic (Gr. , on both sides, κυρτός, convex) or cissoidal (Gr. κισσός, ivy), biconvex; xystroidal or sistroidal (Gr.

Echmatemys wyomingensis The Emydidae are most closely related to the tortoises (Testudinidae) and are included along with that family in the Testudinoidea. Shared features include a lack of inframarginal scutes, the shape and muscle attachment of the ilium, and the shape of the eighth cervical vertebra (biconvex). Within the Emydidae, two subfamilies were recognized along biogeographic lines. The Emydidae as understood today contain New World species (except Emys), while the former Batagurinae, today a separate family Geoemydidae, contain Old World species (except Rhinoclemmys).

In France their fossils are found in well bedded pelagic (deep ocean) limy mudstones, Frasnian in age, with a paleolatatude of about 32° south. Current latitude is 43.4° N. In Western Australia, in Canning Basin, they are found in Frasnian and Famennian, (Upper Devonian), marginal slope and basinal facies related to reef complexes. Paleolatitudes are about 20° S. Current latitude is 18.0° S. Shells of the type genus Aulatornoceras are involute, widely to narrowly umbilicate, with strongly biconvex growth lines. The suture is goniatitic.

The culms are erect, biconvex, glabrous, smooth with a width of between and , they are also quite sharp on the edges. The leaves are yellow to red at the base and have a dark and pointed tip Flowering occurs between the months of May to October. The inflorescences of L longitudinale are brown in color and occur at the top of the stems. Each stem is topped with spikelets that are 5 to 7 mm in length and each contain 2-3 small flowers.

The group can be defined as the most inclusive clade that includes Saltasaurus loricatus but excludes Brachiosaurus altithorax. Features found as diagnostic of this clade by Mannion et al. (2013) include the possession of at least 15 cervical vertebrae; a bevelled radius bone end; sacral vertebrae with camellate internal texture; convex posterior articular surfaces of middle to posterior caudal vertebrae; biconvex distal caudal vertebrae; humerus anterolateral corner "squared"; among multiple others. The following cladogram demonstrates the results of the phylogenetic analysis performed by Fernández-Baldor et al.

A biconvex lens Lenses can be used to focus light A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (elements), usually arranged along a common axis. Lenses are made from materials such as glass or plastic, and are ground and polished or molded to a desired shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing.

Fleas are wingless insects, long, that are agile, usually dark colored (for example, the reddish-brown of the cat flea), with a proboscis, or stylet, adapted to feeding by piercing the skin and sucking their host's blood through their epipharynx. Flea legs end in strong claws that are adapted to grasp a host. Unlike other insects, fleas do not possess compound eyes but instead only have simple eyespots with a single biconvex lens; some species lack eyes altogether. Their bodies are laterally compressed, permitting easy movement through the hairs or feathers on the host's body.

They taper to a point with a gently curved apex and have three nerves per face. When the plant blooms it produces simple inflorescences with obloid to sub-spherical flowerheads that have a length of and a diameter of containing 30 to 36 golden coloured flowers. The narrowly linear seed pods that form after flowering have longitudinal ridges and are straight and biconvex with a length of up to and a width of containing longitudinally arranged seeds. The light brown seeds have an oblong shape with a length of around and a terminal aril.

This leaves the image reversed, but would become common practice in later camera obscura boxes. Giambattista della Porta added a "lenticular crystal" or biconvex lens to the camera obscura description in the 1589 second edition of Magia Naturalis. He also described use of the camera obscura to project hunting scenes, banquets, battles, plays, or anything desired on white sheets. Trees, forests, rivers, mountains "that are really so, or made by Art, of Wood, or some other matter" could be arranged on a plain in the sunshine on the other side of the camera obscura wall.

The fossil remains included vertebrae, limb bones, scapula, hip bones (pubis, ilium, and ischium) and several ribs. Cranial fragments, a mandible, and two teeth have also been discovered. These teeth resemble those of another titanosaurid, Malawisaurus dixeyi. The generic name refers to Rincón de los Sauces, where the fossils were discovered, while the specific name, caudamirus, means "amazing in the tail" in Latin, in reference to the unusual shape of the tail vertebrae, especially a strange sequence of procoelous, amphicoelous, opisthocoelous, biconvex and ultimately again procoelous vertebrae shown by one individual.

The lens is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, it functions to change the focal length of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. This adjustment of the lens is known as accommodation (see also below). Accommodation is similar to the focusing of a photographic camera via movement of its lenses.

Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, which then enter the circulation. Circulating unactivated platelets are biconvex discoid (lens-shaped) structures, 2–3 µm in greatest diameter. Activated platelets have cell membrane projections covering their surface.

In the immediate postwar period, he studied the use of a biconvex wing profile for high-speed aircraft and developed the Schlieren Flow Visualization method of predicting the impact of shock waves on aircraft wings. He then turned at length to the problem of atmospheric reentry, hypersonic thermofluid dynamics, as applied to the study of supersonic and hypersonic jet engines. He also conducted important studies in the fields of supersonic combustion and aerodynamic heating of high speed aircraft. In all these areas, he made key contributions to the advancement of aerospace engineering.

A supersonic airfoil is a cross-section geometry designed to generate lift efficiently at supersonic speeds. The need for such a design arises when an aircraft is required to operate consistently in the supersonic flight regime. Supersonic airfoils generally have a thin section formed of either angled planes or opposed arcs (called "double wedge airfoils" and "biconvex airfoils" respectively), with very sharp leading and trailing edges. The sharp edges prevent the formation of a detached bow shock in front of the airfoil as it moves through the air.

Stone thickness can also vary, from as low as 4 millimeters or as high as 12.8 millimeters, with most between 7.0 mm and 10.1 mm for biconvex and 5–7 mm for single convex. Thick slate and shell stones can last for generations, slowly becoming thinner from handling, and gradually acquiring an ivory-like patina. The diameter of the stones is standardized to around 22 mm ±1 mm, which can fit almost all Go boards. Black stones are slightly larger in diameter to compensate for optical illusion of the white stones appearing larger when placed with black stones of the same diameter.

Drawing of juvenile shell of Anostoma depressum. The shell of this species is biconvex, the altitude about half the diameter, angular at the periphery, whitish, more or less brown- tinted, the base dappled with oblong spots or streaks arranged concentrically, having a dark band along the basal suture, the upper surface sparsely spotted near the periphery, and having a brown band revolving below the suture, usually with a fainter one above it. Surface is finely striate above and below, fresh specimens showing dense fine spiral lines, especially on the last whorl. The shell is composed of 4 whorls, that are nearly flat.

Albert Van Helden, Catalogue of early telescopes, Istituto e museo di storia della scienza (Italy), 1999. (preview) Divini's first publication was a print appeared in 1649 where he intended to document the possibilities offered by his telescopes. Indeed, at the centre he depicted a selenographyenlarged image of Divini's most famous achievement derived from his observations of the full moon in March 1649, using two telescopes, and around the crescent Saturn, Venus and Jupiter. He deserved fame mainly for his use of micrometer eyepiece consisting in a grid of wires inserted in a biconvex eyepiece, thanks to which he could draw the moonspots in the exact position.

Biconvex (or double convex) lens with aperture stop in front of it The early photographic experiments of Thomas Wedgwood, Nicéphore Niépce, Henry Fox Talbot, and Louis Daguerre all used simple single-element convex lenses.Michael R. Peres, Focal encyclopedia of photography: digital imaging, theory and applications, page 55 These lenses were found lacking. Simple lenses could not focus an image over a large flat film plane (field curvature) and suffered from other optical aberrations. Their severe longitudinal chromatic aberration meant the light the photographers were seeing (generally yellow light) and the light to which the early photographic mediums were sensitive not converge to the same point, making it difficult to focus.

The spores have dimensions of (3.8)4.9–5.5(6.6) by (3.3)4.4–5(6.6) by 3.8–4.4 μm, sublentiform (shaped somewhat like a biconvex lens) in face view or roughly elliptic in side view, with an inconspicuous hilar appendage. They have a distinct germ pore in the base, and are smooth and thick-walled. The basidia, the spore-bearing cells in the hymenium, are 12–19 by 4.4–5.5 μm, and hyaline. The pleurocystidia (cystidia on the gill face) are 15–29 by 5.5–8.8 μm; clear, gray or brown in color, fusoid-ventricose to mucronate, sometimes with a median constriction, similar to the species Psilocybe subaeruginosa Clel.

Some other Arthropoda, such as some Myriapoda, rarely have any eyes other than stemmata at any stage of their lives (exceptions include the large and well-developed compound eyes of Scutigera). Behind each lens of a typical, functional stemma, lies a single cluster of photoreceptor cells, termed a retinula. The lens is biconvex, and the body of the stemma has a vitreous or crystalline core. Although stemmata are simple eyes, some kinds, such as those of the larvae of Lepidoptera and especially those of Tenthredinidae, a family of sawflies, are only simple in that they represent immature or embryonic forms of the compound eyes of the adult.

Pentamerida is an order of biconvex, impunctate shelled, articulate brachiopods that are found in marine sedimentary rocks that range from the Middle Cambrian through the Devonian.Moore, Lalcker and Fischer, 1952, Invertebrate Fossils, McGraw-Hill Pentamerids are characterized by a short hinge line where the two valves articulate, inner areas above the hinge line that slope inwardly from the beak of each valve, and a well-developed spondylium on the pedicle valve. The spondylium is a raised platform for muscle attachment found in the middle of the interior pedicle valve, generally toward the hinge and beak. The pedicle valve is the one that the pedicle, or hold-fast stalk, attaches to.

Sigmoilina ia a miliolid genus, referring to the foraminiferal order Miliolida, characterized by an assymmetricall biconvex test formed by strongly overlapping chambers, one-half coil in length, that form a sigmoid (S-shaped) curve in cross section. The strongly overlapping chambers obliterate earlier ones from view resulting in the compressed biloculine appearance, differing from the squat, depressed biloculine form of Pyrgo and Biloculina. The test, as for all Miliolida, is porcelaneous and imperphorate, the terminal aperture, with tooth, the only point of egress and ingress for the animal. Sigmoilina is a protist, or proctoctist according to B.K. Sen Gupta, 1999, included in the miliolid family Hauerinidae (Loeblich & Tappan, 1988).

Sharpirhynchia sharpi has a small shell, subtrigonal to transverse or laterally elongate in adults; unequally biconvex, dorsal valve more convex than ventral one, subglobose in profile. Lateral commissures oblique ventrally; anterior commissure narrowly uniplicate; linguiform extension developed variably, generally low and U-shaped. No clear sulcation on dorsal umbone. Beak relatively long, acute, and suberect, with slightly incurved tip in adult; foramen big, oval, hypothyridid, with well developed rim; deltidial plates narrow, disjunct to just conjunct; beak ridges subangular; interareas small, but well defined and slightly concave, with fine and clear transverse lines. Ventral valve moderately convex; sulcus shallow and wide, well separated from slopes and with rounded bottom, occurring at posterior 1/3 to 1/2 of valve.

Magnification of images was well understood by the time the first devices were constructed in the early 18th century. Basically, the image is placed at the focal point of a biconvex or plano-convex lens (a magnifying glass) allowing someone to view the magnified image at varying distances on the other side of the lens. Court and von Rorh (1935) suggested that the popularity of the early French models was because they allowed presbyopic purchasers to see the images clearly despite the French fashion against wearing glasses. But Chaldecott (1953) doubted this could have been the sole reason for the devices' enduring popularity, leaving the major factor to be the realistic appearance of the depicted images.

The remaining distal carpal, referred to here as the medial carpal, but which has also been termed the distal lateral, or pre-axial carpal, articulates on a vertically elongate biconvex facet on the anterior surface of the distal syncarpal. The medial carpal bears a deep concave fovea that opens anteriorly, ventrally and somewhat medially, within which the pteroid articulates, according to Wilkinson. In derived pterodactyloids like pteranodontians and azhdarchoids, metacarpals I-III are small and do not connect to the carpus, instead hanging in contact with the fourth metacarpal. With these derived species, the fourth metacarpal has been enormously elongated, typically equalling or exceeding the length of the long bones of the lower arm.

Mouse neurula tissues divide rapidly, with an average cell cycle lasting 8–10 hours. Proteoglycans in the extracellular matrix (ECM) of neurula-stage cells play an important role in promoting functional cranial neurulation and neural fold elevation; hyaluronic acid (HA) is synthesized and becomes accumulated, while the cell maintains a low level of sulfated glycosaminoglycans (GAGs). HA is involved in creation of biconvex neural folds, while sulfated GAGs are critical in manipulating the neural groove into a V-shape, as well as in neural tube closure. The ECM does not play a major role in spinal neurulation due to the close-packed nature of the mesodermal cells in the spinal region, which allows little intercellular space.

The design used very thin wings of biconvex section proposed by Jakob Ackeret for low drag. The wing tips were "clipped" to keep them clear of the conical shock wave generated by the nose of the aircraft. The fuselage had the minimum cross-section allowable around the centrifugal engine with fuel tanks in a saddle over the top. One of the Vickers models undergoing supersonic wind-tunnel testing at the Royal Aircraft Establishment (RAE) around 1946 Another critical addition was the use of a power-operated stabilator, also known as the all-moving tail or flying tail, a key to supersonic flight control, which contrasted with traditional hinged tailplanes (horizontal stabilizers) connected mechanically to the pilots control column.

Rays of light travel in straight lines and change when they are reflected and partly absorbed by an object, retaining information about the color and brightness of the surface of that object. Lit objects reflect rays of light in all directions. A small enough opening in a screen only lets through rays that travel directly from different points in the scene on the other side, and these rays form an image of that scene when they are collected on a surface opposite from the opening. The human eye (as well as those of other animals including birds, fish, reptiles etc.) works much like a camera obscura with an opening (pupil), a biconvex lens and a surface where the image is formed (retina).

Kirriemuir Camera Obscura History of Camera Obscuras In the 16th century, Daniele Barbaro suggested replacing the small hole with a larger hole and an old man's spectacle lens (a biconvex lens for correcting long-sightedness), which produced a much brighter and sharper image.Making a camera obscura in your room. National Geographic By the late 18th century, small, easily portable box-form units equipped with a simple lens, an internal mirror, and a ground glass screen had become popular among affluent amateurs for making sketches of landscapes and architecture. The camera was pointed at the scene and steadied, a sheet of thin paper was placed on top of the ground glass, then a pencil or pen could be used to trace over the image projected from within.

Historian Jean De Juanville confirms Al Hasan Al Ramma describing a strange rocket powered projectile that was used by the Arabs against the units of Louis IX during the seventh crusade. Jean De Juanville notes that the French faced these projectiles for the first time when they attempted a maneuver on the banks to one of the eastern arms of the Nile river in their attempt to capture Damietta. But the reaction of the Arabs on the other side of the bank was immediate and launched projectiles that ended up flaming on the French cavalry. The weird weapon was a flattened missile in the shape of a biconvex disk with a charge of black powder and a tail to stabilize the orbit.

It has been suggested that this tradition is older and that instrument maker Johann Wiesel (1583–1662) from Augsburg may have been making magic lanterns earlier on and possibly inspired Griendel and even Huygens. Huygens is known to have studied samples of Wiesel's lens-making and instruments since 1653. Wiesel did make a ship's lantern around 1640 that has much in common with the magic lantern design that Griendel would later apply: a horizontal cylindrical body with a rosette chimney on top, a concave mirror behind a fixture for a candle or lamp inside and a biconvex lens at the front. There is no evidence that Wiesel actually ever made a magic lantern, but in 1674, his successor offered a variety of magic lanterns from the same workshop.

In the space below and above the wing centre section were located the air, fuel, oxidant and warm-air pipes, telemetering transmitter, instruments and batteries as well as the autopilot, timing clock, wiring terminal fuses and the connections by which the test vehicle was carried on the parent aircraft. The rear section housed the combustion chamber, radar transponder, smoke-producing fluid, instruments and oscillators for combustion chamber pressure and tailplane angle, servos and dive mechanism for the tailplane which together with the fixed directional fin were fitted to the lower body prior. The single-piece wing was of mahogany with Dural inserts at the leading and trailing edges; it was of biconvex section and of tapered planform with an unswept half-chord line. The Dural inserts formed a convenient dipole-aerial system for the telemetering unit.

The popularity of Della Porta's books helped spread knowledge of the camera obscura. In his 1567 work La Pratica della Perspettiva Venetian nobleman Daniele Barbaro (1513-1570) described using a camera obscura with a biconvex lens as a drawing aid and points out that the picture is more vivid if the lens is covered as much as to leave a circumference in the middle. Illustration of "portable" camera obscura (similar to Risner's proposal) in Kircher's Ars Magna Lucis Et Umbrae (1645) In his influential and meticulously annotated Latin edition of the works of Ibn al-Haytham and Witelo (1572) German mathematician Friedrich Risner proposed a portable camera obscura drawing aid; a lightweight wooden hut with lenses in each of its four walls that would project images of the surroundings on a paper cube in the middle. The construction could be carried on two wooden poles.

The forewings are white with a large trapezoidal brownish-ochreous patch occupying the disc from one-fourth to two-thirds, resting on the dorsum and extending three-fourths of the way across the wing, the upper and lower margins broadly suffused with grey, the anterior margin with a quadrate grey discal lobe reaching to near the base, a spot of grey suffusion above this towards the costa, the posterior margin biconvex. There is some irregular grey marking on or beneath the costa about two-thirds, a pale ashy-grey fasciate streak irrorated (sprinkled) with dark grey from beneath the costa at four- fifths to the lower part of the termen, and a pale greyish transverse shade between this and the upper part of the discal patch, the costal edge more or less ochreous on the posterior third. The hindwings are grey, becoming paler or whitish tinged anteriorly. The larvae have been recorded feeding on the bark of an unidentified jungle tree.

The rearmost canopy transparencies, on either side of the pilot's seat, had large oval holes in them but the Karakán was one of the first gliders with enclosed seating. Drag from the wing/fuselage junction troubled designers of the day and Lippisch mounted the wings of the Wien from a parallel sided pylon rising rather abruptly from the fuselage; Rotter extended the upper fuselage frames smoothly inwards then outwards into a stub wing, with a span about the same as the maximum fuselage width, to ease the transition from fuselage to wing. The fuselages of both designs became slender rearwards, the Wien's more than the Karakán; sections through the latter's fuselage were more biconvex or almond shaped than the Wien's oval, making it narrower. The Wien and the Karakán had very similar vertical tails, with balanced rudders, large and rounded apart from a straight underside to avoid the ground, mounted on small, short fins.

Next most inclusive, Salgado revitalised Titanosauridae to include everything descended from the ancestor of Epachthosaurus and Saltasaurus, and to replace the node-stem triplet of Saltasauridae, defined the clades Epachthosaurinae and Eutitanosauria as Epachthosaurus>Saltasaurus and Saltasaurus Life restoration of Rinconsaurus, a derived titanosaur possessing unique caudals that significantly change articular surfaces throughout the tail Following the clade definitions proposed in previous Salgado studies, Bernardo González-Riga published two papers in 2003 describing new taxa in Titanosauria: Mendozasaurus, and Rinconsaurus (with Jorge O. Calvo). In both studies, the new taxa formed clades within Titanosauridae, although neither were named, and new diagnostic features were proposed for the family. For Mendozasaurus, the new genus grouped with Malawisaurus as basal within Titanosauridae, but because of the features of caudal vertebrae in these basal taxa, González-Riga recommended revising the diagnosis of the family, instead of changing the content. The situation of caudals in Rinconsaurus also suggested procoelous caudals were no longer diagnostic, because in the tail of Rinconsaurus the vertebrae regularly changed their articular surfaces, being from procoelous caudals interspersed with amphicoelous, opisthocoelous and biconvex vertebrae.