bluuebunny/crossref_metadata_2025_split huggingface dataset:
Submicronic etched features of silicon with high aspect ratio obtained by cryogenic plasma deep-etching through perforated polymer thin films
Authors: Vital A. , Boufnichel M. , Dussart R. , Gosset N. , Lefaucheux P. , Sinturel C. , Tillocher T. , Vayer M. 
Published: April 2015

ABSTRACTWe report the preparation of nanomasks for silicon plasma etching, which is not based on full top-down approaches such as conventional lithographic process. We used laterally phase separated polymers thin films (30 to 100 nm thick) obtained from immiscible polymer blends of poly(styrene) PS and poly(lactide) PLA, PS being the major component, spin-coated onto silicon substrates. Despite the high incompatibility of the two polymers, submicronic domains were obtained in the film. The selective extraction of the minor component (PLA) led to the formation of a perforated layer of PS at the top of the silicon substrate, and was used as a mask for the selective etching of the silicon. For that purpose, we used a cryogenic etching process where the silicon substrate was cooled at a cryogenic temperature (∼ -120°C) and exposed to a monocyclic SF6/O2 plasma. It was possible to etch anisotropic profiles with vertical sidewalls and minimal defects. Etched feature with an aspect ratio of 7 were obtained in these conditions. We determined that the selectivity of etching (Si/PS) was 11:1, with a silicon etching rate of 0.8 µm/min. The selectivity of these masks was further increased when using the inorganic replicas of the polymer template (50:1) or with chemical modifications of the PS by RuO4 (80:1), allowing for increased aspect ratio etched features (up to 20 in the latter case). Optimized etching processes (such as STiGer process) were also used in order to improve the reproducibility and robustness of the method.
Incorporation of Cd1-xMgx Te as an Electron Reflector for Cadmium Telluride Photovoltaic Cells
Authors: Swanson Drew E. , Abbas Ali , Munshi Amit H. , Drayton Jennifer A. , Raguse John M. , Geisthardt Russell M. , Sites James R. , Sampath Walajabad S. 
Published: April 2015

ABSTRACTThe addition of a CdMgTe (CMT) layer at the back of a CdTe solar cell should improve its performance by reflecting both photoelectrons and forward-current electrons away from the rear surface. Higher collection of photoelectrons will increase the cell’s current, and reduction of forward current will increase its voltage. To achieve electron reflection, conformal CMT layers were deposited at the back of CdTe cells, and a variety of measurements including performance curves, transmission electron microscopy, x-ray photoelectron spectroscopy, and energy-dispersive x-ray spectroscopy were performed. Oxidation of magnesium in the CMT layer was addressed by adding a CdTe capping layer. MgCl2 passivation was substituted for CdCl2 in some cases, but little difference was seen.
Sinergismo en la respuesta inmune en ratones BALB/c//BIOULA con parasitosis combinadas: Syphacia obvelata y Leishmania mexicana
Authors: De Jesús Rosa , Pavón Wilmer 
Published: April 2015

Introducción: los ratones balb/c//bioula son usados en experimentos en los que se estudian parásitos de las especies Lehismania mexicana, determinando concentraciones de IgG. En estudios previos se determinó que los ratones parasitados con Syphacia obvelata presentan altas titulaciones de IgG. El objetivo del trabajo fue determinar si existe sinergismo en la respuesta inmunológica de ratones balb/c//bioula con parasitosis combinada.
Materiales y métodos: los animales se distribuyeron como Grupo a, sin parásitos; Grupo b, parasitados con Syphacia obvelata; Grupo c, con Leishmania mexicana y Grupo d, con parasitosis combinada. Durante dos meses se realizaron curvas de crecimiento, diagnóstico coproparasitológico, valoración hematológica y titulación de anticuerpos mediante elisa.
Resultados: en las curvas de crecimiento se observó que los ratones con parasitosis combinadas presentaron la menor ganancia de peso y de talla; la mayor cantidad de huevos y parásitos adultos de Syphacia obvelata; en los parámetros hematológicos, presentaron diferencias estadísticamente significativas en los valores hallados, y al valorar la concentración de IgG, se observó que la mayor cantidad de unidades de IgG se presentaron igualmente para los sueros de los ratones con parasitosis combinadas.
Conclusiones: los resultados de las curvas de crecimiento, las pruebas hematológicas y la titulación de IgG permitieron concluir que existe sinergismo en la respuesta de los ratones al encontrarse parasitados con Syphacia obvelata y Leishmania mexicana. Esto puede conducir a resultados falsos positivos cuando el investigador experimente con Lehismania mexicana y los ratones se encuentren parasitados con Syphacia obvelata.
Douglass Houghton, Michigan's First State Geologist
Authors: Merk George 
Published: April 2015

In 1830, Houghton, only 20 years old and a recent graduate of New York's Rensselaer Scientific School, arrived in the Michigan Territory at the request of its territorial leaders and patrons of science.
He won a reputation as a competent naturalist while serving on the Schoolcraft Expeditions along the shores of Lake Superior and to the Mississippi River in 1831 and 1832. It was at this time that he discovered the true location of the Keweenawan copper deposits and the value of the mineral lands (owned by the Chippewa Indians) west of the meridian of Marquette. This knowledge enabled him to propose that the government of the Michigan Territory relinquish to Ohio its claim to the "Toledo Strip" and in lieu receive the Chippewa lands and attain statehood in January, 1837.
When Michigan became a state, Houghton was appointed Michigan's first State Geologist. Among his accomplishments, in this state largely covered by forests and glacial sediment, was not only to discover and map the basin structure of the sedimentary rocks of the eastern half of Michigan's Northern Peninsula and all the Southern Peninsula, but also to develop a valid theory concerning the formation, structure, and position of Michigan's copper-bearing rocks. In 1843, this theory was presented to the Association of American Geologists, of which he was a founder. But Houghton was never able to complete his geological work: at age 36 he drowned in Lake Superior when a sudden winter storm capsized his boat.
His untimely death, and the fact that young Michigan had little money for publishing scientific reports, helps to explain why Houghton's geological work has not received the national recognition it deserves.
The Schlagintweit Collections
Authors: Armitage G. 
Published: April 2015

This article outlines the significance of some of the discoveries in natural science made in India and the Himalayas by the Schlagintweit brothers, who were eminent nineteenth century scientists and explorers employed by the East India Company to carry out survey work. The mainly natural history subject matter covers zoology, botany, geology, surveying and ethnography. The article also describes how various specimens were collected and transported to the United Kingdom their investigation by scientists and their eventual places of custody in various institutions. Although there are specimens collected by the Schlagintweits in German institutions, the present work concentrates on the collections that were originally housed in the India Museum of the East India Company before its dispersal in 1879.
The paper was written whilst working at the India Office Library and Records, London, which is a department of the British Library, and the notes refer mainly to material held there.
Geochemistry in the Geological Survey of Canada 1842-1952
Authors: Boyle R. 
Published: April 2015

The Geological Survey of Canada, the oldest scientific organization in the nation, was founded in 1842, at a time when major changes were taking place in the sciences of geology, chemistry and biology. Geochemistry was not yet recognized as a science in North America, although the word had been coined and the field outlined in 1838 by C. F. Schönbein, the Swiss chemist.
Thomas Sterry Hunt (1826-1892) was appointed chemist and mineralogist to the Geological Survey in 1847 by Sir William Logan, first director of the Survey. For the next 25 years Hunt carried out geochemical research on most aspects of the science and added materially to the establishment of various geological principles. Sterry Hunt has been called the "Father of Chemical Geology, or Geochemistry, in North America."
Following Hunt, many able men, including B. J. Harrington, F. D. Adams, G. C. Hoffman, and R. A. A. Johnston occupied the position of chemist and mineralogist to the Survey during the period 1872-1922. They were followed by E. Poitevin and H. V. Ellsworth who served from 1922 until 1952.
H. V. Ellsworth laid the foundations of 20th Century geochemistry in the Geological Survey. His extensive studies of the distribution of rare elements (e.g., Li, Zr, Nb, U, Th, etc.) in Canadian minerals and rocks, and his studies of geochronology employing uranium-lead methods, had universal significance in geochemistry.
G. G. Simpson as Sam Magruder: Concession to the Ineluctable
Authors: Laporte Léo 
Published: April 2015

In a posthumously published work of science fiction (The Dechronization of Sam Magruder, St. Martin's Press, 1996) the American paleontologist George G. Simpson (1902-1984) tells the story of Sam Magruder, a "chronologist" living in 2162 A.D, who was experimenting on the "quantum theory of time-motion" when he suffers a "time-slip" that puts him back in the Late Cretaceous of New Mexico. Helplessly lost in time and with no hope of returning to the present, Magruder ekes out a primitive existence for some years until a fatal accident befalls him. Before his death Magruder manages to chisel out his experience and philosophy of life on eight rock slabs that are recovered many millions of years later; and so his story becomes known and discussed by several Everyman characters.
Simpson spins a reasonably engaging tale, but its main interest is the degree to which Magruder's philosophy of life may reflect Simpson's own feelings toward the end of his life. Always more comfortable in expressing his views in writing than in speaking, Simpson appears to use this work of science fiction to reveal his own, mostly melancholy, views about life's meaning and purpose, the importance of adapting to the here-and-now, and how historical contingency controls subsequent outcomes. Is Simpson speaking for himself when Magruder declares "My real purpose in engraving these slabs is a search for comprehension … I am exploring my own nature"?
History of Sedimentologic Concepts Applied to Northern Appalachian Piedmont Metasediments
Authors: Gore Pamela 
Published: April 2015

The northern Appalachian Piedmont is underlain by metamorphosed sedimentary and igneous rocks. The sedimentary origin of many of these rocks was established during the late 1800's. Other rocks, particularly the massive inclusion-bearing metasediments (diamictites), were considered to be xenolithic granites until the 1940's or later.
Relict sedimentary textures and structures are preserved in some Piedmonst metasediments despite sillimanite-grade metamorphism. Few sedimentary structures, other than bedding, were reported until the early 1960's, when graded bedding and sequences of sedimentary structures resembling the Bouma Cycle, characteristic of turbidity current deposits, were reported front metagraywackes in the Maryland Piedmont. The metagraywackes are now interpreted as submarine fan deposits. Few of the metasediments have been studied from a sedimentologic viewpoint. Most of our knowledge of the sedimentary structures and depositional environments has been contributed by igneous and metamorphic petrologists, primarily George W. Fisher and Clifford A. Hopson. Sedimentologists (Juergen Reinhardt and Gregory S. Gohn) working in the Piedmont have dealt primarily with lower metamorphic grade carbonate rocks in the western and northwestern Piedmont.
Early Oil and Gas Exploration to 1879 in Western Crawford County, Pennsylvania
Authors: Pees Samuel 
Published: April 2015

Although lacking the major activity and success of nearby areas in the Pennsylvania shallow oil and gas region, western Crawford County had an early start in exploration. Oil was first encountered in 1819 while deepening a salt well to 300 feet in Beaver Township. After the Drake well of 1859, drilling for oil spread into western Crawford County in 1861. Some of the early drilling sites were in Beaver Township where hydrocarbon shows in the early salt well attested to the presence of petroleum and gas.
The period from 1861 to 1879 saw an estimated 21 wells drilled in western Crawford County, but the number may have been somewhat higher. Thirteen oil wells are located on the 1880 base map used for this study and plotted from field and literature research. Two or three small oil and gas pools were found by this early drilling, but none of them were developed to significant proportions. Gallons of dark green oil were collected from some wells and gas blew the tools out of one hole. Another well at first was thought to have enough gas to light a village.
Israel C. White discussed the petroleum geology of western Crawford County in "The Geology of Erie and Crawford Counties," Second Geological Survey of Pennsylvania, Report of Progress, 1879, published in 1881. One of his major contributions was the tracing of the petroliferous Upper Devonian Venango Third sand from wells in the oil region near Titusville into the mapped area where it also became an objective for drilling. White's stratigraphic nomenclature is compared with current usage, which still contains much of his terminology.
The Beginnings of A Geological Naturalist: Desmarest, The PrintedWord, and Nature
Authors: Taylor Kenneth 
Published: April 2015

Nicolas Desmarest (1725-1815), one of the great pioneering field naturalists of the eighteenth century, began to pursue geological field work only in the later 1750s, Well past the age of 30. Until that time, the patterns of Desmarest's scientific interests and thinking resembled those of a scholarWhose range of experienceWas defined mostly by books. In this essay I attempt to characterize Desmarest's intellectual orientations, prior to his conversion into an investigative naturalist. Before his first efforts in active field research, Desmarest became committed to an empiricist epistemology of a phenomenalist type, emphasizing know ledge of natural regularities in a fashion parallel to views expressed in the early volumes of Histoire Naturelle, by Georges-Louis Leclerc, comte du Buffon (1707-1788). Through his close linksWith antiquarian scholars, Desmarest formed critical mental habits regarding use of historical and archeological evidence in interpretations of the past. These early scholarly experiences helped shape his approach to work as a field geologist. I suggest also that Desmarest's employment as a government analyst of practical and industrial arts, at the very time he began active scientific field work, contributed to his rapid and successful embrace of empirical procedures in science.
Let us consult nature herself, who ordinarily leaves recognizable marks of her operations, even if she likes most often to cloak them in disguise, to hide them from minds unfamiliar with her tricks, or heedless in following their solution.
Nicolas Desmarest, Dissertation sur l'ancienne jonction de l'Angleterre à la France, 1753
British Geology in the Early Nineteenth Century: A Conglomerate with a Female Matrix
Authors: Kölbl-Ebert Martina 
Published: April 2015

During the first half of the nineteenth century—in addition to mining engineers or land surveyors, who used geological knowledge for their profession—a large group of non-professional scientists still existed in British geology. For these people with enough money, time, and leisure to study, travel, and publish, geology was more or less a private interest. In scientific circles such as the Geological Society of London serious workers and dilettantes were found together. The establishment of geology at British universities was at its beginning or still ahead in the future. Because of the informal character of this important part of early British geology, women were not excluded from participation. They were not yet opponents in the competition for jobs, but were welcomed as fellow-enthusiasts. More so, wives, daughters, and sisters or even non-related female acquaintances at that time were an integral part of the infrastructure of scientific work. As a result, there have been many female contributors to geology in the early nineteenth-century in the United Kingdom, forming a framework of assistants, secretaries, collectors, painters, and field geologists to the leading figures in the geological sciences, thereby adding to, and shaping their work.… some of the ladies were very blue1and well-informed, reading Mrs. Somerville, and frequenting the Royal Institution.2W. M. Thackeray: Vanity Fair, 1847
Mary Elizabeth Barber, Some Early South African Geologists, and the Discoveries of Diamonds
Authors: Cohen Alan 
Published: April 2015

The second generation of those Britons who had emigrated to the Cape Colony of South Africa in 18201 included a number of people who had transcended the basic requirements of establishing a subsistence among the relatively inhospitable social, economic, and agricultural climate of their new homeland. They became interested in the scientific study of the nature of their surroundings and in their spare time became keen amateur natural historians, geologists, archaeologists, and ethnologists. Those more intrepid amongst them sought to explore the unknown interior and in the process discovered the vast mineral wealth of the country, in particular diamonds, gold, and coal.
This article seeks to show how one small group of people based around Grahamstown in the Eastern Province of the colony were involved in some of these discoveries, and especially the early discovery of diamonds in the Transvaal. Most of the group were connected in some way with Mary Elizabeth Barber (1818-1899), the daughter of a British gentleman sheep-farmer who arrived in South Africa in 1820. She became a well-known contemporary artist, poet, and natural historian, corresponding with several leading British scientists such as Sir Joseph Hooker and Charles Darwin. Her scientific papers were published, amongst others, by the Linnean Society of London, the Entomological Society of London, and the South African Philosophical Society.
Steps in the History of Mudstone Investigations—A Timeline, 1556 Through 2007
Authors: Potter Paul , Maynard J. , Huff Warren 
Published: April 2015

In 1556, Agricola published the first detailed description of a mudstone posthumously, but it was not until 1747 that one of them (a black shale) was formally defined by William Hooson. A review of the world literature since Hooson's time shows a slow, steady activity in the study of mudstones in the 1800s, a sharp break to more frequent activity in the early 1920s, a decline during World War II, followed by a return to the pre-war level, but then followed in the 1990s by a possible decrease in activity.The trends are similar for both conceptual advances and for new techniques. The break in the 1920s was led by new technologies that expanded observations down to the angstrom level with X-ray diffraction and up to the formation scale with down-hole geophysical logging and seismic reflection. A comparison with a similar compilation for igneous and metamorphic rocks shows the same three phases—early slow phase, intermediate rapid phase punctuated by the Second World War, final slower phase—but in the case of the crystalline rocks, the rapid phase begins much earlier, in the 1880s. We suggest that the common techniques of that time—the petrographic microscope and wet chemistry—were well suited to the investigation of crystalline rocks, but the breakthrough for mudstones had to wait for new technologies.
Notes on Some Early Geological Investigations in Kansas
Authors: Merriam D. 
Published: April 2015

Just a little more than 250 years ago, a Frenchman passed up the Kaw (Kansas) River Valley and made note of the granite and quartzite boulders for what may have been the first recorded notes on the geology of Kansas. Most of the early records were sporadic and not systematically taken. Early expeditions were mainly military; later ones were railroad surveys. Scientists, if on the expeditions, were natural scientists and not geologists, so descriptions usually were of topography, agriculture suitability, transportation feasibility, climate, botany, and other natural phenomena, but seldom of the geology. Documents of these early expeditions, including those of expeditions of Lewis and Clark (1804-6), Pike (1805-7), Long (1819-20), Fremont (1843-45), Emory (1846-47), Stansbury (1849), Marcy (1852), and Beckwith (1853-54) were in a narrative form - long on generalities but short on detail. Thus by the mid-19th century, the geology of Kansas was known only in a general way.The ‘Great American Desert’ was a place to cross, not to stay. The influx of gold seekers and those wanting to exploit the land changed everything and information on the geology became important. To fill the void, ‘guides’ by a variety of self-styled experts on the history, geography, climate, mineral resources, soils, etc., were issued as aids to the emigrants. The guides, usually published by the author, were interesting and popular but included little scientific information. In 1852, David Dale Owen was commissioned a "United States Geologist" and made observations in northeastern Kansas as part of a larger survey. Other geological observations were made by members of early federal government-sponsored territorial surveys of the West. The fossils collected on these surveys and by collectors were described by paleontologists - most reports described the different, new, or spectacular finds. In 1864 the State commissioned the first geological survey headed by B. F. Mudge; the second survey was created in 1865 with G. C. Swallow as State Geologist. Thus the State government assumed responsibility for the surveying - mostly with the idea of making an inventory of economic resources and promoting development of the young state. During the period from creation of the second geological survey in 1865 to the third in 1895, the Kansas Academy of Science Transactions served as one of the leading outlets for information on Kansas geology. The systematic and regular recording of the geology of Kansas commenced in 1895 with creation of the third (and present) State Geological Survey in Lawrence with Erasmus (Daddy) Haworth appointed State Geologist.
Geological Education in Georgia Before 1861
Authors: Cramer Howard 
Published: April 2015

Before the war there were private and "old field" public elementary schools, and also private, individual- and church-supported high-schools called academies, seminaries, or institutes. Some even used the word college. Geology and mineralogy were taught in some of the academies, depending upon the availability of teachers; most had the typical classical education of the day.
There were four colleges: Franklin [the University of Georgia], Mercer [Baptist], Oglethorpe [Presbyterian], and Emory [Methodist]. All had geology in the curriculum, either as a distinct one-semester course [combining the present-day physical and historical geology] or as part of a course in natural history. None was a center of great scientific strength, although both Franklin and Oglethorpe had the services of Joseph LeConte for a short while.
Brief biographies of John R. Cotting, James Jackson, Joseph Jones, William L. Jones, Joseph LeConte, Alexander Means, Josiah Meigs, George W. W. Stone, Joseph Willett, and James Woodward are included.