Several competing models, although correctly dealing with the conformation of each individual peptide chain, gave way to the triple-helical " Madras " model, which provided an essentially correct model of the molecule's quaternary structure although this model still required some refinement .< ref > The packing structure of collagen has not been defined to the same degree outside of the fibrillar collagen types, although it has been long known to be hexagonal or quasi-hexagonal.

Several types of military bridging vehicles have existed through the years.

Several types of chocolate can be distinguished.

Figure 8: Several types of diodes.

Several laboratory scale techniques for distillation exist ( see also distillation types ).

Several thousand patients have been treated with various types of tumours.

Several types of brain lesions can occur in individuals with TSC and 60 %-90 % of people with TSC develop epilepsy.

Several grappling styles like Judo, Shoot wrestling, Catch wrestling, Brazilian jiu-jitsu, Sambo and several types of wrestling including Freestyle and Greco-Roman have gained global popularity.

Several types are existent in Qing dynasty and used in dishes of stewing hams ( 火腿炖肘子 ), and vegetables, or for a wide variety of soup and important soup stocks.

Several types of FDA approved vacuum therapy devices are available with a doctor's prescription.

Several types of wild greens, known collectively as chwinamul ( such as Aster scaber ), are a popular dish, and other wild vegetables such as bracken fern shoots ( gosari ) or Korean bellflower root ( doraji ) are also harvested and eaten in season.

Several different types of light sources exist, each having different properties that affect their appropriateness for certain tasks, particularly efficiency and spectral power distribution.

Several types of molecules are particularly important during morphogenesis.

Several types of cell adhesion molecules are known and one major class of these molecules are cadherins.

Several types of plasmid addiction systems ( toxin / antitoxin, metabolism-based, ORT systems ) were described in the literature and used in biotechnical ( fermentation ) or biomedical ( vaccine therapy ) applications.

Several cell types may be present in the epidermis.

Several types of RNA can downregulate gene expression by being complementary to a part of an mRNA or a gene's DNA.

Several types of visual prosthesis are in development or trials in humans, and one device has been approved for sale in the European market.

Several types of random samples are simple random samples, systematic samples, stratified random samples, and cluster random samples.

Several types of mushroom ( het ) also feature in Thai cuisine such as straw mushrooms ( het fang ) and white jelly fungus ( het hu nu khao ).

) Several types of naval " torpedo " were developed and deployed, most often by the Confederates, who faced a severe disadvantage in more traditional warfare methods.

Several types of fish can detect ultrasound.

Several types of pumps may be used in sequence or in parallel.

Several types have technological importance, for example, in liquid crystal displays.

Several organizations, such as the American Association of Variable Star Observers and Center for Backyard Astrophysics, exist to help coordinate these contributions.

Several of the dialects have been influenced by contact with non-Germanic linguistic groups, such as the dialect of Carinthia, where in the past many speakers were bilingual with Slovene, and the dialect of Vienna, which has been influenced by immigration during the Austro-Hungarian period, particularly from what is today the Czech Republic.

Several unusual applications, such as a nuclear battery or fuel for space ships with nuclear propulsion, have been proposed for the isotope < sup > 242m </ sup > Am, but they are as yet hindered by the scarcity and high price of this nuclear isomer.

Several biographical programs have been made, such as the 2004 BBC television programme entitled Agatha Christie: A Life in Pictures, in which she is portrayed by Olivia Williams, Anna Massey, and Bonnie Wright.

Several references to the god Abraxas appear in Hermann Hesse's 1919 novel, Demian, such as:

Several attempts to find a new home failed ; one such stop was on Sicily where in Drepanum, on the island's western coast, his father, Anchises, died peacefully.

Several cultivars are known, such as ' Albus ' ( with white flowers ), ' Sapphire ' ( dark blue flowers ), ' Aureus ' ( leaves striped with yellow ), and ' Variegatus ' ( leaves almost entirely white with a few green bands ).

Several people who spoke to Selkirk after his rescue ( such as Captain Rogers and the journalist Steele ) were impressed by the tranquillity of mind and vigour of the body that Selkirk had attained while on the island.

Several related flagellates, such as Perkinsus and Colpodella have structures similar to the polar ring and were formerly included here, but most appear to be closer relatives of the dinoflagellates.

Several new commercial Atari 7800 titles such as Beef Drop, B * nQ, Pac Man Collection, Combat 1990, Santa Simon, and Space War have been created and released.

Several modern approaches build on such continental European exemplars as Heidegger, and apply metaphysical results to the understanding of human psychology and the human condition generally ( notably in the Existentialist tradition ).

Several crashed airplanes and large equipment such as bulldozers are scattered around the island.

Several Eastern Bloc countries adopted trolleybus systems, and their manufacturers such as Trolza exported trolleybuses to other friendly states.

Several arboreal primate species, such as Gibbons and Indriids, exclusively utilise bipedal locomotion during the brief periods they spend on the ground.

( Several Labour ministers of later generations, such as Michael Foot and Tony Benn, were the sons of Liberal MPs.

Several other territorial claims such as Sipadan were resolved at The Hague international courts.

Several rating scales for the screening and evaluation of bipolar disorder exist, such as the Bipolar spectrum diagnostic scale.

Several of Canada's largest companies are based in natural resource industries, such as EnCana, Cameco, Goldcorp, and Barrick Gold.

Several contemporary bands have Welsh language songs, such as Ceredwen, which fuses traditional instruments with trip-hop beats, the Super Furry Animals, Fernhill, and so on ( see the Music of Wales article for more Welsh and Welsh-language bands ).

Several condensed matter experiments involve scattering of an experimental probe, such as X-ray and optical photons, neutrons etc., off constituents of a material.

Several languages of North America, such as Mohawk, lack both of the labials and.

Several brain imaging techniques, such as EEG and fMRI, have been used for physical measures of brain activity in these studies.

Several impact craters and massive volcanic activity, such as that in the Deccan Traps, have been dated to the approximate time of the extinction event.

Several churches, such as the Anabaptists and Socinians of the Reformation, then Seventh-day Adventist Church, Christadelphians, Jehovah's Witnesses, and theologians of different traditions reject the idea of the immortality of a non-physical soul as a vestige of Neoplatonism, and other pagan traditions.

Several serpentinite deposits are being investigated as potentially large scale CO < sub > 2 </ sub > storage sinks such as those found in NSW, Australia, where the first mineral carbonation pilot plant project is underway.