149 Sentences With "helicoid" | Random Sentence Generator

In April, she had a hyperbolic helicoid — a fantastically swirly helix, somewhat like a seashell — tattooed to her left shoulder.

In this case, Boulon Blanc's table uses helicoid motion with an X-based mechanism in order to change sizes with just one simple rotation.

The 1965 gallery, among the best here, juxtaposes the saturated hues of Kenneth Anger's discreetly homoerotic underground short "Kustom Kar Kommandos" (to the sound of the Paris Sisters' "Dream Lover"), with a similar example of controlled flamboyance: Roger Tallon's cast-aluminum "Helicoid Staircase," a rippling spiral of cantilevered steps uncluttered by a railing.

Animation showing the transformation of a helicoid into a catenoid. The helicoid and the catenoid are locally isometric surfaces; see Catenoid#Helicoid transformation.

If the profile curve is a line one gets a ruled generalized helicoid. There are four types: :(1) The line intersects the axis orthogonally. One gets a helicoid (closed right ruled generalized helicoid). :(2) The line intersects the axis, but not orthogonally.

A helicoid with α = 1, −1 ≤ ρ ≤ 1 and − ≤ θ ≤ . The helicoid, after the plane and the catenoid, is the third minimal surface to be known.

Deformation of a helicoid into a catenoid Because they are members of the same associate family of surfaces, one can bend a catenoid into a portion of a helicoid without stretching. In other words, one can make a (mostly) continuous and isometric deformation of a catenoid to a portion of the helicoid such that every member of the deformation family is minimal (having a mean curvature of zero). A parametrization of such a deformation is given by the system :x(u,v) = \cos \theta \,\sinh v \,\sin u + \sin \theta \,\cosh v \,\cos u :y(u,v) = -\cos \theta \,\sinh v \,\cos u + \sin \theta \,\cosh v \,\sin u :z(u,v) = u \cos \theta + v \sin \theta :for (u,v) \in (-\pi, \pi] \times (-\infty, \infty), with deformation parameter -\pi < \theta \le \pi, where \theta = \pi corresponds to a right-handed helicoid, \theta = \pm \pi / 2 corresponds to a catenoid, and \theta = 0 corresponds to a left-handed helicoid.

"Molecular phylogeny of the helicoid land snails (Pulmonata: Stylommatophora: Helicoidea), with special emphasis on the Camaenidae". Journal of Molluscan Studies 73(4): 411-415. .

Because they are members of the same associate family of surfaces, a catenoid can be bent into a portion of a helicoid, and vice versa.

The lip is buff. The interior is ochraceous brown. The protoconch consists of two small helicoid whorls. Sculpture:—The first whorl is keeled, and develops small radial ribs.

Serpiginous choroiditis, also known as geographic or helicoid choroidopathy, is an uncommon chronic progressive inflammatory condition affecting adult men and women equally in the second to seventh decades of life.

The almost opaque, glossy, white shell is solid. The length measures 5 mm. The protoconch has a helicoid shape. The teleoconch contains six, flattened whorls with a narrow, distinct suture.

Serpiginous choroiditis, also known as geographic or helicoid choroidopathy, is an uncommon chronic progressive inflammatory disease affecting adult men and women equally in the second to seventh decades of life.

The catenoid and the helicoid are two very different-looking surfaces. Nevertheless, each of them can be continuously bent into the other: they are locally isometric. It follows from Theorema Egregium that under this bending the Gaussian curvature at any two corresponding points of the catenoid and helicoid is always the same. Thus isometry is simply bending and twisting of a surface without internal crumpling or tearing, in other words without extra tension, compression, or shear.

The shell is short, and robust. Its length measures 5.5 mm. It is rose pink, but wax yellow at tip. The 2½ whorls of the protoconch are very small, low, and helicoid.

If all the rulings of a Catalan surface intersect a fixed line, then the surface is called a conoid. Catalan proved that the helicoid and the plane were the only ruled minimal surfaces.

The milk-white shell is small and slender. Its length measures 3.7 mm. The 1¾ helicoid whorls of the protoconch are depressed. Their axis is at right angles to that of the succeeding turns.

The earliest expeller presses utilized a continuous screw design. The compression screws were much like the screws of a screw conveyor—that is, the helicoid flighting started at one end and ended at the other.

The slender, milk- white shell has an elongate-conic shape. The length of the shell measures between 7.5 mm and 10 mm. The protoconch contains three whorls. These are large, helicoid, rather elevated, and smooth.

The white, shiny shell has ta slender, elongate-conic shape. The length of the shell varies between 1.8 mm and 1.8 mm. The whorls of the protoconch are helicoid. The teleoconch contains 4½ to 5 flat whorls.

The height of the shell attains 3.1 mm, its diameter 1.5 mm. The stoutly built and polished shell has a pupiform shape. The four whorls are depressed convex. The spiral and helicoid apex consists of 2½ turns.

The protoconch consists of two small smooth helicoid whorls. Sculpture:—The first adult whorl shows numerous small radial riblets. On the subsequent whorls the ribs are spaced seven to a whorl. They are continuous, perpendicular, and elevated.

A rendering of Costa's minimal surface. A minimal surface is a surface which has zero mean curvature at all points. Classic examples include the catenoid, helicoid and Enneper surface. Recent discoveries include Costa's minimal surface and the Gyroid.

The small, slender shell is subdiaphanous to milk white. Its length measures 3 mm. The 2½ whorls of the protoconch are helicoid but slightly elevated and well rounded. Their axis is at right angles to the axis of the teleoconch.

The bluish-white shell has a conic shape with straight sides. Its length measures 4 mm. The whorls of the protoconch have a depressed helicoid shape. There are six to seven whorls in the teleoconch showing an almost smooth sculpture.

The subdiaphanous to dingy white shell is small. Its length measures 5.3 mm. The 2½ helicoid whorls of the protoconch are loosely coiled, decidedly elevated, and about one-fifth immersed. Their axis is at a right angle to that of the later whorls.

The size of the shell varies between 10 mm and 20 mm. The depressed, umbilicate shell is helicoid or almost stomatia-shaped. The body whorl and aperture are very large. Its color is reddish-brown, marked with white on the spiral ribs.

The cream-colored shell has an elongate-ovate shape. Its length measures 2.3 mm. The whorls of the protoconch number at least two. They form a smooth, depressed helicoid spire, which is obliquely three-fifths immersed in the first of the succeeding turns.

The slender shell is elongate, conic, milk-white. It measures 3 mm. The three nuclear whorls are moderately large, helicoid. They have their axis at a right angle to the axis of the later whorls and are scarcely immersed in the first of them.

The shell has an elongate-conic shape. Its length measures 6.2 mm. The two helicoid whorls of the protoconch are depressed. Their axis is at nearly right angles to that of the succeeding turns, in the first of which they are very slightly immersed.

The slender shell has an elongate-conic shape. Its posterior half between the sutures is light yellow; the anterior half of the base is chestnut. The length of the shell measures 4.8 mm. The two whorls of the protoconch form a depressed, helicoid spire.

The thin, semitranslucent, bluish white shell has an elongate-conic shape. Its length measures 4.9 mm. The whorls in the protoconch number at least two. They are rather large, depressed helicoid, well rounded, and about half immersed in the first of the succeeding turns.

In addition, these particles can also jam or otherwise hinder the focusing feature of a lens if they enter into the focusing helicoid. The problem of sensor cleaning has been somewhat reduced in DSLRs as some cameras have a built-in sensor cleaning unit.

The small shell is semitransparent. The length measures 4.7 mm. The 2¼ whorls of the protoconch are small, depressed, and helicoid. Their axis is at right angles to that of the succeeding turns, in the first of which they are about one- fifth immersed.

Animation showing the deformation of a helicoid into a catenoid. The deformation is accomplished by bending without stretching. During the process, the Gaussian curvature of the surface at each point remains constant. A sphere of radius R has constant Gaussian curvature which is equal to 1/R2.

The bluish-white, slender shell has an elongate-conic shape. Its length measures 7.4 mm. The 2½ whorls of the protoconch are small and helicoid. Their axis is at right angles to that of the succeeding turns, in the first of which they are slightly immersed.

The bluish-white shell is long and slender. Its length measures 7.9 mm. The 2½ helicoid whorls of the protoconch are small, depressed. Their axis is at right angles to that of the succeeding turns, in the first of which they are about one-fifth immersed .

Wade, C.M., Hudelot, C., Davison, A., Naggs, F., Mordan, P.B. Molecular phylogeny of the helicoid land snails (Pulmonata: Stylommatophora: Helicoidea), with special emphasis on the Camaenidae. Journal of Molluscan Studies 73: 411-415.Bouchet, P., Rocroi, J.P. Classification and Nomenclator of gastropod families. Malacologia 47: 1-397.

The shell of this species is thin and helicoid, with smooth and polished whorls. The inner lip is callous and indented, but the callus is not sufficiently large to cover or conceal the umbilicus. The peristome is produced into an angle, which ascends on the body whorl.

The milk-white shell is small and slender. Its length measures 4.3 mm. The 2¼ whorls of the protoconch form a depressed, helicoid spire. Its axis is at right angles to that of the succeeding turns, in the first of which it is very slightly immersed.

Stipules are absent, but persistent; enlarged axillary bud scales (pseudostipules) are often present. Domatia occur in some genera. Dolichandrone falcata in Hyderabad, India Flowers are solitary or in inflorescences in a raceme or a helicoid or dichasial cyme. Inflorescences bear persistent or deciduous bracts or bractlets.

The milk-white shell has an elongate-conic shape. Its length measures 8.3 mm. The two, small whorls of the protoconch are depressed and helicoid. They have their axis at right angles to that of the succeeding turns, in the first of which they are about one-third immersed.

Chapters 6, 7, and 8 cover specific geometric objects with negatively-curved surfaces, including the pseudosphere, helicoid, and catenoid, investigate mathematical toys, and use these crocheted models "to explore otherwise hard to visualize objects". A final chapter covers the applications of hyperbolic geometry and its ongoing research interest.

In this case the surface is a tangent developable surface and is generated by the directrix (d\cos \varphi,d\sin\varphi,c\varphi). Remark: # The (open and closed) helicoids are Catalan surfaces. The closed type (common helicoid) is even a conoid #Ruled generalized helicoids are not algebraic surfaces.

The broadly conic shell is yellowish-white. The 2½ whorls of the protoconch are very small. They form a rather elevated helicoid spire. Its axis is at right angles to that of the succeeding turns, in the first of which it is a little more than half immersed.

The shell has an elongate-conic shape. It is milk-white, with a broad yellow band a little anterior to the middle of the whorls between the sutures. Its length varies between 3.6 mm and 4.3 mm. The two whorls of the protoconch form a depressed helicoid spire.

The thin shell is fusiform or subcylindrical. The colour ranges from uniform buff, with or without chocolate spiral lines or bands, to entire chocolate. The protoconch consists of two or three smooth helicoid whorls. Fasciole don't interrupt the sculpture, and are scarcely indicated by the curvature of growth lines.

The large, bluish-white shell is slender and has an elongate conic shape. Its length measures 9.2 mm. The 2¼ whorls of the protoconch are small, and depressed helicoid. Their axis is at right angles to that of the succeeding turn, in the first of which they are slightly immersed.

The yellowish white shell is slender and has an elongate-conic shape. Its length measures 6.3 mm. The 2½ whorls of the protoconch are small, and depressed helicoid. Their axis is at right angles to that of the succeeding turns, in the first of which they are about one-fourth immersed.

The bluish-white shell is semi translucent and has an elongate-conic shape. Its length is 4.7 mm. The 2½ whorls of the protoconch form a rather solute, elevated, helicoid spire. Its axis is at right angles to the succeeding turns, in the first of which it is slightly immersed.

The shell length attains 11 mm; its diameter 4 mm. The slender, glossy shell is fusiform. It contains 7 whorls, of which 1½ compose a small, smooth, helicoid protoconch. Its colour is white, ornamented with four to six pale orange bands, appearing only in the interstices, not on the ribs.

The length of the shell varies between 2.7 mm and 3.5 mm. The white shell has a conical shape with a spiral microstructure and with a blunt top. The protoconch is helicoid. The teleoconch contains six to seven flat whorls with a relatively deep suture and a few axial folds.

The white shell moderately large measuring 3.2 mm. It is elongate-conic, with decidedly channeled sutures. The nuclear whorls number at least 2, forming a depressed helicoid spire, which is obliquely, almost one- half immersed in the first of the succeeding turns. The six post-nuclear whorls are moderately rounded.

The small, diaphanous shell has an elongate-conic shape. Its length measures 3.2 mm. The 2½ whorls of the protoconch are small and helicoid. They form a moderately elevated spire, with their axis at right angles to that of the succeeding turns, in the first of which they are about one-fifth immersed.

The milk-white shell has a conic shape. Its length measures 3 mm. The 2½ whorls of the protoconch are well rounded. They form a depressed helicoid spire, the axis of which is at right angles to that of the succeeding turns, in the first of which it is about one-third immersed.

The shells of Amphidromus are relatively large, from one to three inches high, and colorful. Amphidromus has an elongate-conic or ovate-conic helicoid shell of 5 to 8 whorls. The shell may be thin and fragile, or very heavy and solid, with no known correlation of shell structure with distribution or habitats.

Dijksterhuis studied mathematics at the University of Groningen from 1911 to 1918. His Ph.d. thesis was entitled "A Contribution to the Knowledge of the Flat Helicoid."Reijer Hooykaas (1967) "Eloge: Eduard Jan Dijksterhuis (1892 — 1965)" Isis 58(2): 223–225 From 1916 to 1953 Dijksterhuis was a professor and taught mathematics, physics and cosmography.

The milk-white shell has an elongate-conic, turreted shape. Its length measures 4.4 mm. The three whorls of the protoconch are small, helicoid, rather loosely coiled and elevated. They have their axis at a right angle to the axis of the later whorls and about one-third immersed in the first of them.

Thompson & Naranjo-García (2012) described a new family Echinichidae and placed it to the superfamily Xanthonychoidea.Thompson F. G. & Naranjo-García E. (2012). "Echinichidae, a new family of dart-bearing helicoid slugs from Mexico, with the description of a new genus and three new species (Gastropoda: Pulmonata: Xanthonychoidea)". Archiv für Molluskenkunde 141(2): 197-208. . preview.

The length of an adult shell varies between 5 mm and 130 mm. There is also a wide variation in the shape of the shell. This goes from low auriform (ear-shaped) with a wide aperture to the long, slender conical forms of typical top shells. The shape may also be subglobose, turbinate or helicoid.

The shell is small and slender. Its length measures 5.5 mm. Its color is chestnut brown with a wax yellow apex The 2½ whorls of the protoconch form a depressed helicoid spire. Its axis is at right angles to that of the succeeding turns, in the first of which it is one-fourth immersed.

The crystal siltsnail, also known as the helicoid spring snail, scientific name Floridobia helicogyra, is a species of small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Hydrobiidae. This species is endemic to the United States. Its natural habitat is rivers. It is threatened by habitat loss.

The height of the shell attains 3.5 mm, its diameter 5 mm. The sublenticular shell is, wax colored, with irregular blotchings and spottings of very pale chestnut brown. The upper surface is depressed and has a helicoid shape. The nucleus consists of a little more than one whorl, which is well rounded and smooth.

The conic shell is, milk-white. It measures 2.0 mm. The whorls of the protoconch number at least two, forming a depressed helicoid spire, which is slightly tilted to one side and for the greater part immersed in the first of the succeeding turns. The tilted edge of the nucleus shows traces of spiral lirations.

The milk-white shell is very slender and has an elongate- conic shape. The shell grows to a length of 2.7 mm. The 1¾ whorls of the protoconch are depressed, and helicoid. Their axis is at right angles to that of the succeeding turns, in the first of which they are very slightly immersed.

The shell is very small and slender. Its length measures 3.6 mm. It has a light yellow color, with a darker band immediately posterior to the periphery, and another slender one about halfway between the middle of the space between the sutures and the summit. The 2½ whorls of the protoconch are depressed and helicoid.

The shell has an ovate shape. Its length measures 2.3 mm. The 2 ½ whorls of the protoconch form a depressed helicoid spire whose axis is at right angles to that of the succeeding turns. The four whorls of the teleoconch are well rounded, moderately contracted at the sutures, and very slightly shouldered at the summit.

The light brown, shining shell has an elongate-conic shape. The length of the shell measures 17.6 mm. The 2½ whorls of the protoconch are small and polished, and have a depressed helicoid shape. Their axis is at a right angle to the axis of the later whorls and about one-sixth immersed in the first of them.

The very slender, diaphanous to milk-white shell has an elongate-conic shape. Its length measures 4.4 mm. The 2½ whorls of the protoconch are small. They form a small elevated helicoid spire, the axis of which is at right angles to that of the succeeding turns, in the first of which it is about one-third immersed.

The small shell has a conic shape. Its color is light chestnut, with the umbilical area white. Its length is 2.9 mm. The 2½ whorls of the protoconch form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one- third immersed.

The shell has an elongate-conic shape. The anterior half of whorls is chestnut brown, the rest flesh colored. The length of the shell measures 7.2 mm. The two whorlsof the protoconch form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is one-fifth immersed.

The pale yellowish brown shell has an elongate conic shape . Its length measures 6.1 mm. The 2½ whorls of the protoconch are well rounded. They form a very depressed helicoid spire, the axis of which is at right angles to that of the succeeding turns in the first of which it is about one- fourth immersed.

The pale yellow horn-colored shell has a broadly elongate conic shape. Its length measures 5.5 mm. The 2½ whorls of the protoconch are well rounded. They form a decidedly depressed helicoid spire having its axis at right angles to that of the succeeding whorls, in the first of which, the tilted edge is about one-fourth immersed.

If the sympodium is always formed on the same side of the branch bifurcation, e.g. always on the right side, the branching structure is called a helicoid cyme or bostryx. If the sympodium occurs alternately, e.g. on the right and then the left, the branching pattern is called a scorpioid cyme or cincinus (also spelled cincinnus).

The length of the shell varies between 7 mm and 13 mm. The helicoid shell is widely umbilicated, fulvous, punctate with red. The 6½ whorls are convex and somewhat loosely rolled on themselves which causes the sutures to very deep. They are traversed by spiral granulose cinguli ornamented with red dots, and alternately larger and smaller.

The comparatively thin and semi- transparent shell is of helicoid shape is light-brown to greenish-yellow horn, occasionally with a narrow, red subsutural band and a small, red circumumbilical patch. The shell has 5 1/8 to 5 5/8 whorls with last whorl slowly descending. Very slightly elevated apex and spire. The aperture is subcircular.

The milk-white shell has a light yellow narrow band midway between the sutures. Its length measures 3.3 mm. The 2½ whorls of the protoconch are small. They form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-third immersed.

The soiled white shell is elongate-conic. It measures 4.8 mm. The at least two whorls of the protoconch are moderately large, helicoid, one-half obliquely immersed in the first volution of the teleoconch, the periphery projecting slightly beyond the left outline of the spire. The six whorls of teleoconch are well rounded, very slightly shouldered.

The white shell is elongate-ovate. Its length measures 1.4 mm. The 2 ½ whorls of the protoconch are large and form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-fifth immersed. The three whorls of the teleoconch are well rounded.

The yellowish white shell has a regularly, broadly elongate conic shape. Its length measures 5.2 mm. The 2½ smooth whorls of the protoconch form a decidedly depressed helicoid spire. Its axis is at right angles to that of the succeeding turns in the first of which about one-fourth of the side of the spire is immersed.

The milk-white, smooth shell has a pupiform shape. The length of the shell varies between 3 mm and 4.3 mm. There are at least two small whorls in the protoconch. They form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about two-thirds immersed.

There are two types of thylakoids—granal thylakoids, which are arranged in grana, and stromal thylakoids, which are in contact with the stroma. Granal thylakoids are pancake-shaped circular disks about 300–600 nanometers in diameter. Stromal thylakoids are helicoid sheets that spiral around grana. The flat tops and bottoms of granal thylakoids contain only the relatively flat photosystem II protein complex.

The light yellow horn-colored shell has an elongate conic shape. Its length measures 4.8 mm. The 2½ whorls of the protoconch are well rounded. They form a decidedly depressed helicoid spire, the axis of which is at right angles to that of the succeeding whorls, in the first of which the tilted edge of the nucleus is about one-fifth immersed.

Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia (Description of Gibbula fucata) The height of the shell attains 5.6 mm, its diameter 7.3 mm. The elevated shell has a helicoid shape. Its apex is red, the rest variously spotted, streaked and blotched with Indian red, pale yellow, light green and brown. The 2½ nuclear whorls are well rounded and smooth.

Apertural view of Miralda diadema The white, small shell grows to a length of 1.8 mm. It is subovate, minutely umbilicated, with the summits of the whorls decidedly tabulated. The two helicoid whorls of the protoconch are moderately large, and about one-third immersed in the later whorls. The five whorls of the teleoconch are moderately rounded, decidedly tabulated at the summit,.

The white shell has a very elongate-conic shape. Its length measures 3.1 mm. The two whorls of the protoconch form a moderately elevated helicoid spire which is about one-half obliquely immersed in the first of the succeeding turns. The six whorls of the teleoconch are almost flattened, strongly contracted at the suture and strongly shouldered at the summit.

The 2¼ nuclear whorls are depressed helicoid. The postnuclear whorls are evenly rounded, marked with two, broad, spiral bands, which extend over the anterior half of the whorls between the sutures, where they appear as two turns of a bandage. The periphery of the body whorl is marked by a moderately strong spiral keel which renders it angulated. The sutures are feebly constricted.

The milk-white shell has an elongate-conic shape. The length of the shell measures 3.6 mm. The 2¾ whorls of the protoconch form a decidedly elevated helicoid spire, the axis of which is at right angles to that of the succeeding turns, in the first of which they are about one-fourth immersed. A complete shell would probably have twelve whorls in the teleoconch.

The white shell has a pupiform shape. Its length measures 2.5 mm. The 1½ whorls of the protoconch form a moderately elevated helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-third immersed. The seven whorls of the teleoconch are moderately rounded, somewhat contracted at the sutures, and strongly tabulated on the summits.

George Washington Tryon, Structural and systematic conchology: an introduction to the study of the Mollusca, p. 219; 1882 (Description of Gibbula gaudiosa) The height of the shell attains 5.6 mm, its diameter 5.7 mm. The moderately elevated shell has a helicoid shape. It is red, with four regularly spaced triangular sectors of greenish yellow, on the last turn and one on the whorl preceding this.

The color of the shell is wax yellow on the early whorls, ranging to chestnut brown on the last. Its length measures 3.7 mm. The 2½ whorls of the protoconch form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-third immersed. The seven whorls of the teleoconch are well rounded.

The milk-white shell has an elongate-conic shape. Its length measures 2.3 mm. The three whorls of the protoconch form an elevated helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is almost half immersed. The seven whorls of the teleoconch are moderately rounded, somewhat contracted at the suture, and strongly shouldered at the summit.

The nests of P. subnuda bees are spherical in shape and are relatively small in size (1000–1500 bees). The nest is protected by several sheets of involucrum, which helps keep the nest insulated in the moist underground environments. Within the outer protective involucrum layer is the helicoid brood comb, which contain eggs’ cells. The comb's cells can either be pear-shaped or larger and normal shaped.

Fuxianospira gyrata is a Cambrian macroalgae found in the Chengjiang lagerstatte. Preserved in clustered, helicoid groups, the filaments are threadlike, plain and without branches. Brown and smooth in appearance, these structural characteristics display a resemblance to modern brown algae. A limited amount of algae species have been discovered in the Chengjiang biota, suggesting that diversity within the general algae population may have been sparse.

American Mathematical Soc., 2005 The transformation can be viewed as locally rotating the principal curvature directions. The surface normals of a point with a fixed ζ remains unchanged as θ changes; the point itself moves along an ellipse. Some examples of associate surface families are: the catenoid and helicoid family, the Schwarz P, Schwarz D and gyroid family, and the Scherk's first and second surface family.

The elongate-conic, slender shell is vitreous. It measures 2.5 mm. The two and one-half nuclear whorls form a depressed helicoid spire, whose axis is almost at right angles to that of the succeeding turns, in the first of which it is about one-half immersed. The seven post-nuclear whorls are very slightly rounded, strongly constricted at the sutures and prominently shouldered at the summit.

The shell is clausiliform. Its length measures 3.8 mm. The two whorls of the protoconch form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is scarcely at all immersed. The first 2½ whorls of the seven of the teleoconch are loosely coiled, strongly rounded, smooth and separated by very strongly impressed sutures.

The white, small shell has a pupiform shape. The whorls of the protoconch number at least two. They form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-half immersed. The five whorls of the teleoconch are well rounded, moderately contracted at the suture, slightly shouldered at the summit.

The small, white shell has a broadly conic shape. Its length measures 3 mm. The three whorls of the protoconch form a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-third immersed. The 5½ whorls of the teleoconch are strongly rounded, moderately contracted at the suture, broadly tabulated at the shoulder.

It contains seven whorls, including a smooth helicoid tip. The radials are wide spaced, prominent, flexuous, perpendicular, and continuous ribs, which diminish at the shoulder and gradually vanish on the base. On the antepenultimate whorl there are ten, and on the body whorl eight, including the varix. The spirals are extremely fine and close threads, evenly distributed over the whole surface, and microscopically beaded.

The 2½ whorls of the protoconch are smooth, rather large, helicoid, and moderately elevated. Their axis is at a right angle to the axis of the later whorls and about one-fourth immersed in the first of them. The periphery of the protoconch extends slightly beyond the outline of the spire on the left side. The eight whorls of the teleoconch are flattened and quite high between the sutures.

The pale yellowish brown shell is rather large (compared to the other species in this genus) and has an elongate conic shape. Its length measures 6.5 mm. The 2½ whorls of the protoconch are well rounded. They form a decidedly depressed helicoid spire, the axis of which is at right angles to that of the succeeding turns in the first of which the tilted edge is about one-fifth immersed.

The milk-white shell has a broadly elongate-conic shape, very regularly tapering and is subturrited. The type specimen measures 5 mm. The 2½ whorls of the protoconch are small, helicoid, well rounded, moderately elevated, about one-third immersed in the first of the later whorls, having their axis almost at a right angle to them. The seven whorls of the teleoconch are rather high between the sutures.

The latter has 2½ whorls, the first two being smooth and helicoid. The next half whorl carries about ten sharp, narrow, arcuate, radiate riblets, quite discordant with the succeeding sculpture. The adult whorl begins abruptly with seven prominent ribs, which descend the whorls vertically and continuously. These are traversed by spaced spiral cords which commence with two on the third whorl and end with seventeen on the body whorl.

The milk-white shell is small and has an elongate-conic shape. Its length measures 4.1 mm. The 2½ whorls of the protoconch form a depressed, helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-fifth immersed. The nine whorls of the teleoconch are slightly rounded, appressed at the summit, and moderately contracted at the suture.

The elongate-conic shell is semitranslucent and measures 5.8 mm. The whorls of the protoconch are small, forming a depressed helicoid spire, which is a little more than half obliquely immersed in the first of the succeeding turns. The eight whorls of the teleoconch are moderately rounded, marked by four strong, equal, and almost equally spaced spiral cords which are separated by three well-incised spiral grooves. The suture is subchanneled.

The small, milk-white shell is pupiform and generally cancellated. It measures 3.2 mm. The whorls of the protoconch number at least two, forming a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is all but one-half immersed. The seven whorls of the teleoconch are flattened, strongly contracted at the suture and decidedly shouldered at the summit.

The bluish-white shell has a very elongate conic shape. Its length measures 3.3 mm. The two whorls of the protoconch are smooth, forming a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about half immersed. The eight whorls of the teleoconch are moderately rounded, slightly shouldered at the summit, somewhat contracted at the sutures.

The shell contains 4 whorls, of which two constitute the protoconch, the last descending, and in slight contact with its predecessor. The protoconch is smooth, helicoid, and sharply defined. The sculpture of the shell shows in the body whorl twenty-four, in the penultimate whorl nineteen, elevated curled and forwardly-directed lamellae, whose broad summits nearly equal their interstices. The lamellae are smooth and glossy, but the interstices are distantly spirally striated.

The milk-white shell has an elongate-conic shape. Its length measures 5.2 mm. The 2½ whorls of the protoconch form a depressed, helicoid spire, the axis of which is at right angles to that of the succeeding turns, in the first of which it is about one-fifth immersed. The nine whorls of the teleoconch are slightly rounded on the anterior two-thirds between the sutures, the posterior third forming a strong sloping shoulder.

Matter and light are the sacred essence of all creation, the founding elements of life and mankind… The brighter the signs, the deeper they echo within… Then our eyes are caught by the colors projected by LEDs through a spinning helicoid, inviting us to enter the ever-changing magnetic vortex of polar lights and their haunting mystery.See Laure Ducos, "De New York à Alès, Roger Katan reste allumé," Midi Libre, Oct. 14, 2012.

The Archimedes screw consists of a screw (a helical surface surrounding a central cylindrical shaft) inside a hollow pipe. The screw is usually turned by windmill, manual labor, cattle, or by modern means, such as a motor. As the shaft turns, the bottom end scoops up a volume of water. This water is then pushed up the tube by the rotating helicoid until it pours out from the top of the tube.

The genitalia are essentially similar to those of Odontostomus. The genitalia are exceedingly lengthened in Ringicella. The genitalia are of the haplogonous type, the long slender penis passing into a long vas deferens, upon which the penis retractor muscle is inserted; the duct of the globular spermatheca is extremely long. The elongation of the whole genital system is greater than in Helicoid snails generally, and doubtless correlated with the unusual length of the last whorl.

When the worm is extended it can reach 450 millimetres in length with a diameter of up to 5 millimetres. The colour varies but is usually orangish-brown with a red, orange or green lophophore. This organ has about 1,500 tentacles, each some 2.5 millimetres long, arranged in a pair of helicoid whorls with four to seven coils. These project from the seabed and are the only part of the animal normally visible.

The shell is very small, measuring 2 mm. It is semitranslucent, bluish-white. The nuclear whorls are quite large, forming a moderately elevated, helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-fourth immersed. The five post-nuclear whorls are decidedly rounded, with the greatest convexity falling on the anterior third of the whorls, between the sutures, appressed at the summit.

This family is characterized in general by usually the lack of an operculum, by a deep anal sinus on the subsutural ramp and with a heavy callus on the shoulder slope of the outer lip. The Mangeliidae are small to medium-sized gastropods (length usually smaller than 30 mm). The high-spired shell has a fusiform to an oval or biconical shape. The protoconch is helicoid, with a very small initial, and rapidly increasing subsequent whorls.

They are coiled to resemble a small sinistral pupa. This pupoid shape makes this species peculiar, as most species in Turbonilla have a helicoid or planorboid protoconch. It is situated obliquely upon the spire of the whorls of the teleoconch and extending considerably beyond the lateral outline of this. The 12 whorls of the teleoconch are situated rather high between the sutures, somewhat overhanging (this is particularly true of the earlier volutions), and slightly shouldered at the summit.

The elongate-conic shell tapers to an extremely slender apex. The polished shell is white, with a slight suffusion of brown at the apex and near the aperture. Its length measures 17.3 mm. The two whorls of the protoconch are large, compared with the early whorls of the teleoconch, helicoid, depressed, smooth, having their axis almost at a right angle to the axis of the later whorls and extending beyond the outline of these on the left side.

Hedleyella falconeri has a helicoid (spiral) shell and grows to a height of about . The colour is some shade of brown marked with radially arranged irregular bands and splotches of black. When the snail is quiescent, the head and foot are retracted into the shell, but these are extended when the animal wants to move around and feed. The upper surface of head and foot has a reticulate pattern in grey and the foot is rimmed with orange.

They form a depressed helicoid spire, which is a little more than half obliquely immersed in the first of the succeeding turns. The five whorls of the teleoconch are well rounded, and feebly shouldered at the summit. They are marked by quite regular, equal and equally spaced, fine spiral lirations, of which 9 occur upon the first and second, 10 upon the third, and 11 upon the penultimate turn between the sutures. The suture is decidedly constricted.

The large, white, shining shell is similar in form to Odostomia (Amaura) avellana. It measures 9.6 mm and is one of the larger species within this genus. The three whorls of the protoconch are helicoid, quite elevated, deeply immersed in the first of the succeeding whorls, having their axis at a right angle to the axis of the later whorls. The six whorls of the teleoconch are well rounded, with a beveled shoulder at the summits.

The small, slender shell is elongate-conic. It measures 2.4 mm. The two and one-half whorls of the protoconch form a moderately elevated helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-fifth immersed. The six whorls of the teleoconch overhang and are strongly contracted at the sutures, appressed at the summit, angulated at the posterior extremity of the anterior third.

One gets an oblique closed type. If the given line and the axis are skew lines one gets an open type and the axis is not part of the surface (s. picture). :(3) If the given line and the axis are skew lines and the line is contained in a plane orthogonally to the axis one gets a right open type or shortly open helicoid. :(4) If the line and the axis are skew and the line is not contained in ... (s.

They are depressed, and helicoid. Their axis is at right angles to that of the succeeding turns, in the first of which they are about one-half immersed. The eight whorls of the teleoconch are well rounded, depressed at the summit, and somewhat contracted at the sutures. They are marked by slender, almost vertical axial ribs, of which 20 occur upon the first and second, 22 upon the third, 24 upon the fourth, 26 upon the sixth and penultimate turn.

Jean Baptiste Meusnier Meusnier's dirigible Jean Baptiste Marie Charles Meusnier de la Place (Tours, 19 June 1754 — le Pont de Cassel, near Mainz, 13 June 1793) was a French mathematician, engineer and Revolutionary general. He is best known for Meusnier's theorem on the curvature of surfaces, which he formulated while he was at the École Royale du Génie (Royal School of Engineering). He also discovered the helicoid. He worked with Lavoisier on the decomposition of water and the evolution of hydrogen.

Costa's minimal surface, cropped by a sphere STL model of the surface In mathematics, Costa's minimal surface, is an embedded minimal surface discovered in 1982 by the Brazilian mathematician Celso José da Costa. It is also a surface of finite topology, which means that it can be formed by puncturing a compact surface. Topologically, it is a thrice-punctured torus. Until its discovery, the plane, helicoid and the catenoid were believed to be the only embedded minimal surfaces that could be formed by puncturing a compact surface.

The nave in the Sagrada Familia with a hyperboloid vault. Inspiration from nature is taken from a tree, as the pillar and branches symbolise trees rising up to the roof. This study of nature translated into his use of ruled geometrical forms such as the hyperbolic paraboloid, the hyperboloid, the helicoid and the cone, which reflect the forms Gaudí found in nature. Ruled surfaces are forms generated by a straight line known as the generatrix, as it moves over one or several lines known as directrices.

They form a depressed helicoid spire, which is obliquely half immersed in the first of the succeeding turns. The seven whorls of the teleoconch are moderately rounded at first, later flattened. They are ornamented by almost straight, vertical, slender, well-developed axial ribs, of which there are 22 upon the first, 24 upon the second to fifth, and 25 upon the penultimate turn. The intercostal spaces about as wide as the ribs, marked by five equal but not equally spaced series of spiral pits.

The small shell measures 2.1 mm. It is umbilicated, elongate-ovate conic, semitransparent, polished. The 2½ whorls of the protoconch are moderately large, helicoid, elevated, about one-fifth immersed in the first of the succeeding whorls and having their axis at a right angle to them. The five whorls of the teleoconch are flattened, angulated at the periphery and weakly shouldered at the summit; the latter falls somewhat anterior to the periphery of the preceding whorl and lends to it a somewhat constricted appearance at the well-impressed suture.

Gaudí found abundant examples of them in nature, for instance in rushes, reeds and bones; he used to say that there is no better structure than the trunk of a tree or a human skeleton. These forms are at the same time functional and aesthetic, and Gaudí discovered how to adapt the language of nature to the structural forms of architecture. He used to equate the helicoid form to movement and the hyperboloid to light. Concerning ruled surfaces, he said: Another element widely used by Gaudí was the catenary arch.

The question as to whether a minimal surface with given boundary exists is called Plateau's problem after the Belgian physicist Joseph Plateau who carried out experiments on soap films in the mid-nineteenth century. In 1930 Jesse Douglas and Tibor Radó gave an affirmative answer to Plateau's problem (Douglas was awarded one of the first Fields medals for this work in 1936).Douglas' solution is described in . Many explicit examples of minimal surface are known explicitly, such as the catenoid, the helicoid, the Scherk surface and the Enneper surface.

They form a depressed helicoid spire. Its axis is at right angles to that of the succeeding turns, on the first of which it rests, but is not immersed. The nine whorls of the teleoconch are situated exceedingly high between the sutures, and moderately rounded. They are marked by slender, very regular, slightly curved, well rounded, somewhat retractive axial ribs, of which 24 occur upon the first, 22 upon the second and third, 24 upon the fourth and fifth, 26 upon the sixth and seventh, and about 32 upon the penultimate whorl.

The small shell is elongate-conic, rather stout and semitranslucent. The nuclear whorls are small, two and one-half, forming: a depressed helicoid spire, whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-fourth immersed. Post- nuclear whorls are flattened, moderately contracted at the sutures and slightly shouldered at the summit, marked by very strong, lamellar, somewhat retractive axial ribs, of which 14 occur upon all of the whorls. The termination of these ribs form cusps at the summits.

The broadly conic shell is pale yellow, with a broad dark wax yellow band, which extends over a little more than one-half the distance from the middle of the whorls to the summit, between the sutures. A secondary of the same color extends from a little posterior to the periphery to the middle of the base. Its length measures 5.8 mm. The 2½ whorls of the protoconch are small and form a depressed helicoid spire, the axis of which is at right angles to that of the succeeding turns, in the first of which they are very slightly immersed.

They formi a depressed helicoid spire, the axis of which is at right angles to that of the succeeding turns, in the first of which it is about one- fifth immersed. The eleven whorls of the teleoconch are moderately well rounded and slightly shouldered at the summit. They are marked by strong, broad, well rounded, somewhat protractive axial ribs, of which 20 occur upon the first to sixth, 22 upon the seventh to ninth, and 24 upon the penultimate turn. These ribs extend prominently from the summit to the periphery of the whorls, but do not cross the latter.

Number of Canon EF lenses sold over time (red), compared with Nikon F mount lenses (blue) The EF mount replaces its predecessor, the FD mount. The standard autofocus lens mounting technology of the time used a motor in the camera body to drive the mechanics of the focus helicoid in the lens by using a transfer lever. The key innovation of the EF series was to use a motor inside the lens itself for focusing. This allowed for autofocusing lenses which did not require mechanical levers in the mount mechanism, only electrical contacts to supply power and instructions to the lens motor.

The mount itself has two bayonets, one inside the camera and another outside. Lenses that use the bayonet inside the camera need have no focusing helicoid built into the lens barrel. As a consequence, the 5 cm f/1.4 lens that was normally sold with the body is extremely small (about the size of a golf ball) since the lens contains the optics only. Focusing of such lenses could be done by rotating the toothed wheel on the top front of the camera body or by rotating the lens barrel itself (the distance scale is on the camera body).

They form a depressed helicoid spire which has its axis at right angles to the axis of the succeeding turns and is about one-fifth immersed in the first of them. The exposed portion of the nine whorls of the teleoconch are flattened in the middle, the posterior fourth sloping gently toward the summit, which is closely appressed to the preceding turn. The anterior portion slopes more abruptly, roundly toward the periphery. The whorls are ornamented by strong rather distantly spaced, moderately acute, slightly protractive axial ribs, of which 18 occur upon the first three, 16 on the next three, 18 on the seventh, and 20 upon the penultimate turn.

Variability in the stack height allows more overall light to be reflected and this further enhances the glossy appearance, but it makes the fruit appear somewhat pixelated. In addition to simply reflecting light of a specific wavelength, the helicoid structure also causes light of other wavelengths to be modified so that the wavelength converges to within a narrow range before being reflected, which acts to amplify the light at that specific wavelength. This process of constructive interference produces the most intense coloration of any living organism. The total reflectivity is about 30% of that of a silvered glass mirror, and is the highest of any known biological material.

First established in October 1982, opening at sixty-four million yen, the company first got involved in the PC gaming industry developing a variety of games including Platformers, Wrestling, Board and Mahjong games for the MSX and FM7. They made their first start to making games for home consoles as well as establishing American game distributions with the Sega Mega Drive/Genesis from 1989 to 1992. Micronet developed games for Sega consoles as well as one or two Arcade, Super Famicom and PlayStation games (mostly for Japan). Some of their games were notable for being hybrid games, a combination of two different game genres such as Helicoid and Heavy Nova.

The external bayonet is used to mount longer and heavier lenses where the built-in helicoid would not be strong enough to rotate the lens barrel. Such lenses are focused using a focusing ring and distance scale on the lens just like typical SLR lenses (the distance scale on the camera body will be covered by the lens flange and thus not visible). Nikon produced a very large range of Nikkor lenses for these cameras with focal lengths from 21mm to 1000mm. Several other manufacturers including Fuji (now Fujifilm), Komura and Zunow made S-mount lenses at the time of which the Zunow 5 cm f/1.1 lens is a keenly sought after collectors item.

Ilse Kleemann, On the Authenticity of the Getty Kouros, in The Getty Kouros Colloquium, 1993, p. 46 Other features that suggest a similarity with known originals include the helicoid curls of the hair, closest in form to the west Cyclidian Kea kouros (NAMA 3686), the Corinthian form of the hands and the sloping shoulders akin to the Tenea kouros and the broad plinth and feet comparable to the Attic or Cyclidian Ptoon 12. That the Getty kouros cannot be identified with any one local atelier does not disqualify it as a genuine, but if real it does require of us that we admit a lectio difficilior into the corpus of archaic sculpture. Some indication of tool marks remain on the work.

The Symington, Biggar and Broughton Railway's extension to Peebles was authorised on 3 July 1860 but by the time construction was complete in 1863 the company had been absorbed by the much larger Caledonian Railway. The bridge is smaller but of similar design to the nearby Neidpath Viaduct and it often confused with it. Located just to the north of the River Tweed, it was built to carry the Symington to Peebles branch line obliquely at a height of over Lyne Water, close to its confluence with the Tweed and consists of three sandstone skew arches each of span and laid with helicoid courses, and a plate girder approach span of to the west. The total length of the structure is .

The shell, aside from its helicoid shape (not a character of great importance), differs from all Pupillidae in the arrangement of the lamellae and baso-palatal folds. In multidentate Pupillidae the five primary teeth are always recognizable while in Strobilops only the main parietal lamella and the columellar lamella can certainly be said to correspond, and these are found in so many other land shells that their occurrence is not especially significant. It is possible, however, that upper and lower palatal folds of Pupillidae are represented by teeth 5 (the most right basal tooth) and 2 (second left basal tooth), and the basal fold by tooth 1 (the most left basal tooth). By the accelerated lamellae and folds of the shell, which appear early in the neanic stage, Strobilops resembles various Tornatellininae (within Achatinellidae).

As the deck is too close to the water, the arcs ought to be elevated above the deck and affixed at each end to a giant stone abutment, 22 m x 18 m in dimension. The approach to the bridge from the left bank (Gare d'Austerlitz) posed no particular issue to the construction project but it wasn't practical to remove the existing structures on the right bank to clear way for the bridge exit. Therefore, to circumvent this problem, instead of a straight exit leading out from the main bridge (like the one on the left bank), a curved structure was erected with riveted girders parallel to the rails. The helicoid ramp, which has a radius of approximately 75 m and a 40‰ gradient, bends in until the rails point downstream.

Definition of a ruled surface: every point lies on a line In geometry, a surface S is ruled (also called a scroll) if through every point of S there is a straight line that lies on S. Examples include the plane, the lateral surface of a cylinder or cone, a conical surface with elliptical directrix, the right conoid, the helicoid, and the tangent developable of a smooth curve in space. A ruled surface can be described as the set of points swept by a moving straight line. For example, a cone is formed by keeping one point of a line fixed whilst moving another point along a circle. A surface is doubly ruled if through every one of its points there are two distinct lines that lie on the surface.

The large, robust shell is chocolate-brown. The two whorls of the protoconch are moderately large, forming a helicoid spire whose axis is at right angles to that of the succeeding turns, in the first of which it is about one-fifth immersed. The eight whorls of the teleoconch are very strongly sculptured, with three spiral keels between the sutures, one of which at the summit is slender, the other two are strong and equal, the supraperipheral one being about as far posterior to the suture as the one at the summit is from its neighbor. In addition to the spiral keels the whorls are marked by narrow retractive axial ribs, of which 14 occur upon the first, 16 upon the second to third, 18 upon the fourth, 20 upon the fifth and sixth, and 24 upon the penultimate turn.

James Hoffman has created software for scientific visualization, particularly of surface geometries studied in differential geometry. While a graduate student at the University of Massachusetts Amherst, James was enlisted by mathematician David Hoffman to help prove an important result in minimal surface geometry, discovering the first new examples of complete embedded minimal surfaces in more than one hundred years. The first example, the Costa surface, was described in 1983 by Brazilian graduate student Celso Costa as an equation, but a proof that it was embedded (lacked self-intersections) was provided by David Hoffman and William Meeks, who used computer visualizations created by James to see that the surface was embedded and dissect it to prove that it was. This finding, followed by the discovery of scores of other surfaces and families of surfaces illustrated by Hoffman's computer graphics, overturned a century-old conjecture that the only examples of such minimal surfaces where the plane, catenoid, and helicoid.

Minolta MD 2/85 mm adapted to NEX 5 Other third-party mechanical tube adapters are also available. These adapters enable the use of Canon FD-mount, Canon EF-mount (without aperture control), Contax G, M42 screw mount, Konica Hexanon AR-mount, Minolta SR-mount (MC/MD), Leica M and screw mount, Nikon F-mount (non-G), Pentax K-mount (non- DA), T2 screw mount and Minolta/Konica Minolta/Sony A-mount lenses. The E-mount flange register is so short that it is possible to mount 45 mm or longer-focal-length non-focusing enlarging lenses on the NEX body, with the use of an intermediate focusing helicoid behind them. Certain third-party mechanical adapters also provide circular control rings that provide some mechanical control of the aperture of Nikon G, Pentax DA and Canon EF lenses, as these do not have a mechanical aperture control ring on their lens barrels.