Federico Villarreal
Federico Villarreal, Peruvian mathematician and astronomer (Túcume, Lambayeque 31 August 1850 – Barranco, Lima 03 June 1923) Authored over 600 works and scientific notes Developed method to raise any polynomial to any power or Villarreal polynomial (1873) Enunciated 3 theorems about divisibility criteria being two of them (in Aportes a la teoria de los numeros 1897) 1) the ratio between two numbers represented by same digits in two distinct systems of basis enumeration is divisible by basis difference 2) a number is divisible by a certain divisor if it is the sum of its digits when one write in enumeration system in which the basis is the divisor plus a unit Obtained a generalization formula for Bernoulli integration formula (1879) in Integración por Traspasos Obtained a fourth degree differential equation for flexion problem of a truss Enunciated theorems about inertial moments and central nuclei of regular polygons (1911) in Tratado de Resistencia de Materiales Discovered embedment moments Discovered new formulas for studying semiregular solids First to study the inscribed sphere in edges of regular and semiregular bodies and the sphere that have polyhedral faces as tangential planes Solved the theoretical problem of disruptive discharge obtaining Thompson formula for oscillations period of a capacitor in Descarga Oscilante en un Condensador (1916) Developed a simple method for determination of meridian, sun time, geographical latitude and longitude Metodo para determinar la latitude y longitude de los lugares del Perú (una tecnica sencilla para la determinación de meridianos, la hora solar, las latitudes e longitudes geograficas) EPONYMY Villarreal polynomials Villarreal child problem (1906) Villarreal recurring formula LINKS http://www.arrakis.es/~mcj/villarreal.htm
Eloy Valenzuela
Juan Eloy de Valenzuela y Mantilla, Colombian botanist (San Juan de Girón, Santander Department 25 June 1756 – Bucaramanga 01 November 1834) It is said that he discovered and/or described some plant species such as one Hidrolea sp., one Grewia sp., one Curatella sp. and two Malva spp. SOME BIBLIOGRAPHY Flora de Bucaramanga Noticia sobre la caña solera Noticia de una espécie de grama util para potreros o pastos artificiales Noticia de una mina de azufre y otros fósiles Descripción de una turma silvestre, tan útil como las que se cultivan, pero enteramente desconocida de las gentes, y tal vez ignorada de los botánicos HONORS Valenzuelia S. Mutis 1810 (Simaroubaceae) Eloyella P. Ortiz 1979 (Orchidaceae)
Egbert Cornelis Nicolaas Van Hoepen
Egbert Cornelis Nicolaas Van Hoepen, Dutch-born South African paleontologist and archaeologist (Vlissingen 10 November 1884 – Edemale, near Johannesburg 02 May 1966) Collector of prehistoric stone artefacts Collected thousands of invertebrate fossil specimens from the Cretaceous strata of Zululand DESCRIBED NEW FOSSIL GENERA Mollusca (Cephalopoda) Acanthotrigonia 1929 Amcleceras 1942 Andersonites 1965 Arestoceras 1946 Askoloboceras 1944 Basseoceras 1968 Cainoceras 1946 Cechenoceras 1941 Collignonella 1957 Deiradoceras 1931 Diplasioceras 1946 Drepanoceras 1931 Eedenoceras 1968 Ensorites 1969 Erioliceras 1955 Euspectroceras 1946 Falsebayites 1965 Fluminites 1965 Fraudatoroceras 1965 Hluhluweoceras 1965 Iotrigonia 1929 Komeceras 1944 Lethargoceras 1946 Letheceras 1946 Linotrigonia 1929 Lophoceras 1931 Matsumotoceras 1968 Megatrigonia 1929 Mimeloceras 1946 Morrisites 1969 Omocyrtoceras 1955 Ophryoceras 1942 Pelecodiscus 1921 Petinodiscus 1944 Pisotrigonia 1929 Pterotrigonia 1929 Ptilotrigonia 1929 Rhytidoceras 1931 Ricnoceras 1942 Rinetrigonia 1929 Rutitrigonia 1929 Tegragonoceras 1955 Terascoceras 1944 Tetagmenoceras 1946 Zuluiceras 1965 Zuluites 1965 Zuluscaphites 1955 Reptilia Dromicosaurus 1920 Eucnemesaurus 1920 Gigantoscelus 1916 Jonkeria 1932 Kolpochoerus 1932 with Van Hoepen Pedeticosaurus 1915 Platycraniellus 1917 Stylochoerus 1932 Synaptochoerus 1932 Tapinochoerus 1932 Mammalia Eurygnathohippus 1930 Kolpohippus 1932 Kraterohippus 1930 Megalotragus 1932 Orangiatherium 1932 Pelorocerus 1932 Sterrohippus 1930 Stylohipparion 1930 Amphibia Uranocentrodon 1917 Crustacea Pseudohomarus 1962 HONORS Hoepenites Collignon 1952 (Fossil Mollusca)
David Eduard Van Dijk
David Eduard Van Dijk, South African herpetologist and paleontologist (Heidelberg District, Transvaal 14 September 1925 – DESCRIBED NEW TAXA Living Amphibia Genus Hadromophryne 2008 Fossil Insecta Genera Afroedischia 1999 with Geertsema Afroperla 2004 with Geertsema Afrostenovicia 1999 with Geertsema Permoxenopterum 2011 with Gorochov Stenotegmocicada 1999 with Geertsema Species Afroedischia oosthuizeni 1999 with Geertsema Afroperla permiana 2004 with Geertsema Afrostenovicia reidae 1999 with Geertsema Callietheira granthami 1999 with Geertsema Epimastax hesterae 2011 with Rasnitsyn Karoohymen minutus 1999 with Geertsema Permocicada thompsoni 1999 with Geertsema Permoxenopterum laticostum 2011 with Gorochov Prochoristella balgowanensis 1999 with Geertsema Prochoristella bulwerensis 1999 with Geertsema Stenotegmocicada triclades 1999 with Geertsema Fossil Plants (with Lacey & Gordon-Gray 1975) Genera Buthelezia Mooia Rigbya Rusangea Species Belemnopteris elongata Buthelezia mooiensis Fetura natalensis Mooia lidgettonioides Rigbya arberioides Rusangea elegans HONORS Vandijkophrynus Frost, Grant, Faivovich et al. 2006 (Amphibia)
Daniel Moreira Vital
Daniel Moreira Vital, Brazilian cryptogamic botanist (América Dourada, Bahia State 02 October 1924 – DESCRIBED MUSCI TAXA Genus Paranapiacabaea 1992 with Buck Subgenus Campylopidulum 1984 Species Jonesiobryum cerradense 1991 Jonesiobryum termitarum 1991 Paranapiacabaea paulista 1992 with Buck HONORS Danielia Skvortzov 1967 (Ochrophyta) Vitalianthus Schuster & Giancotti 1993 (Hepaticae)
Daniel Alberto Valencio
Daniel Alberto Valencio, Argentine geophysicist (Buenos Aires 16 June 1928 – Buenos Aires 25 May 1987) Authored 147 papers and 3 books Internationally well known for his research contributions in palaeomagnetism and geotectonics Obtained the South American polar wandering curve With K.M. Creer & B.J.J. Embleton. Comparison between the upper Palaeozoic and Mesozoic palaeomagnetic poles for South America, Africa and Australia. Earth Planet Sci. Lett. 7(3):288-92, 1969 Papers in Nature With J.F.A. Vilas. Age of the separation of South America and Africa. Nature 223 (1353), 1969 With J.F.A. Vilas. Palaeomagnetism of some middle Jurassic lavas from South East Argentina. Nature 255 (5229):262-4, 1970