bluuebunny/crossref_metadata_2025_split huggingface dataset:
William Barton Rogers and the First Geological Survey of Virginia, 1835 - 1841
Authors: Milici Robert , Hobbs C. 
Published: April 2015

Virginia was the fifth state in the United States to establish a geological survey. Support for this bold venture to develop the state's mineral wealth came from the Geological Society of Pennsylvania, several prominent Virginia citizens, and county legislators. On March 6, 1835 the General Assembly passed an act to authorize a geological reconnaissance. Shortly thereafter William Barton Rogers was appointed to direct the survey, as well as being elected to the chair of natural philosophy at the University of Virginia in Charlottesville. Within a nine-month period he prepared a report on limestones, sandstones, granites, slates, soapstones, coal, ores of iron, copper, gold, and other materials having economic potential. This report influenced the legislature to give financial support to the survey through April 1842. He prepared six annual reports and numerous papers and in 1853 left Charlottesville for Boston, Massachusetts, where he founded the Massachusetts Institute of Technology. Rogers identified several rock units using stratigraphic names correlative with those in Pennsylvania and New York. His works were among the first to deal with igneous and metamorphic rocks in the state. He and his brother, Henry Darwin Rogers, made the first major structural synthesis of the Appalachian chain, recognizing inverted folds and reverse faults. Rogers' works were used as a basis of the development of Virginia geology and mineral resources beyond his demise in 1882. Emma Rogers, his wife, compiled his papers and reports, a vital legacy published in 1884.
William and Henry were in constant contact with one another and many other geologists during their years of study in the Appalachian mountains. Indeed, they relied heavily upon Conrad and Hall of New York for detailed paleontologic and stratigraphic work, which they applied to their own areas in Virginia and Pennsylvania.
Henry Rogers and James Hall of the Pennsylvania and New York Geological Surveys, 1836 to 1842
Authors: Hoskins Donald 
Published: April 2015

The Pennsylvania and New York Geological Surveys received authorization in 1836, within days of each other. Their authorization ended in 1842, within a few months of the other. Largely through the indomitable characters of James Hall and Henry Rogers, after authorization lapsed, both Surveys continued and produced large, important volumes on the geology of their respective states that set the framework for much of the later geological survey work of the Appalachians.
New York had its John Dix, who was the Secretary of State, and Pennsylvania had its Charles Trego, Member of the House of Representatives - both government officials who shaped the course of each Survey. But the differences in the Paleozoic rocks - thin, ubiquitously horizontal and replete with fossils in New York; thick, repetitively folded and faulted, with fewer well-preserved fossils, in Pennsylvania - determined the approaches and results of these Surveys.
From the efforts of the State Geologists of New York and Pennsylvania, along with Edward Hitchcock of Massachusetts, was born the Association of American Geologists, this later to became the American Association for the Advancement of Science. Not all of the interactions between the two surveys were to be so cooperative. Hall sought to obtain other states' information for his maps. Refused by Henry Rogers, Hall circumvented him by contacting Charles Trego, who later became an impediment to Rogers' plans for publication of the Pennsylvania reports.
Luminaries of the Albany Era: Beecher, Schuchert, and Hall
Authors: Cloud Preston 
Published: April 2015

James Hall of Albany, Director of the New York State Museum from 1866 until his death at 86 in 1897 was the most noted American geologist and paleontologist of his time. He originated the geosynclinal concept of mountain-building and ideas of gravity-mass-movement. He became the 19th century's most productive paleontologist by dint of unsparing drive, coupled with high ability and the talent and labors of six unusual "personal assistants".
Among the latter were two gifted and dedicated Charleses, Beecher and Schuchert, who later established invertebrate paleontology at Yale and made it the North American mecca of the field for many years. Beecher, comfortably raised, well educated, biologically focussed, tragically short-lived, preceded his close friend and successor in Hall's employ, Schuchert, son of an impoverished immigrant cabinet maker, with only a primary school education, was geologically inclined, and long-lived. Coming to New Haven as he did, after 10 years of experience with the U.S. Geological Survey and the Smithsonian's Museum of Natural History, as well as his time in Albany, Schuchert provided the ideal complement to Beecher. Both were fine collectors, preparators, and illustrators as well as first rate scientists. Both became renowned scientists in their time. And both enriched the global scientific heritage with their publications.
The Albany School was clearly the place to launch a career in paleontology during the last half of the 19th century. The subsequent lives of Beecher and Schuchert testify to that.
A History of Geology and Geological Education in China (to 1949)
Authors: Zhang Dazheng , Faul Carol 
Published: April 2015

References to geology are in the earliest Chinese writings. However, the literature was little disseminated-and mostly unknown to the rest of the world until recently.
The purpose of the imperial examination system, which began in the Sui Dynasty (581-618), was to select government officials- and thus greatly influenced topics studied by ambitious Chinese, The natural sciences were not included, and even mathematics was eventually excluded. Therefore, education in the sciences was neglected and the study of geology was virtually ignored.
It was not until late in the Qing Dynasty (1644-1911) that the government formulated a policy to introduce foreign science and technology into China. Modern geologic ideas were introduced with the establishment of technical schools and the translation into Chinese of works by James D. Dana and Charles Lyell during the 1870s. Early in the twentieth century, foreign geology teachers were brought to China and Chinese students were sent to foreign countries to study geology. This infusion successfully developed the modern teaching and practice of geology in China.
Forty Years of Thinking in Front of the Alps: Saussure's (1796) Unpublished Theory of the Earth
Authors: Carozzi Albert 
Published: April 2015

The four volumes of Voyages dans les Alpes.. published by Horace Bénédict de Saussure (1779-1796) consist of the description of seven trips, organized chronologically only in part. A large portion of Saussure's descriptions represents a composite assemblage of observations and interpretations, often not updated, borrowed from numerous itineraries, repeated many times during various years. The planned theory of the earth, mentioned repeatedly throughout the volumes, is replaced at the end by an Agenda or listing of observations to be made by his followers as a basis for this theory.Circumstances and poor health prevented Saussure from writing his theory. Fortunately, all his personal papers have been preserved, and among them are carefully-dated field notes and short memos summarizing his ideas at a given time. These documents allow one to reconstruct the evolution of his geological thinking and to present what his unpublished theory, based mainly on the structure of the Alps, might have been.Several phases in Saussure's thinking show his struggle to untangle himself from a pre-Wernerian to Wernerian heritage, and to break new ground dictated by his observations. These phases are discussed in chronological order under headings describing Saussure's new ideas.Two versions (1786 and 1796) of the table of contents of Saussure's incomplete theory of the earth indicate the evolution of his synthesis toward a mature and almost modern outlook of planet earth.
Earliest History of Vertebrate Paleontology in Utah: Last Half of the 19th Century
Authors: Miller Wade , Hall Dee 
Published: April 2015

Aside from the recorded travels of Juan de Rivera in 1765 and the Dominguez-Escalante party in 1776, the earliest reports involving explorations into Utah were mostly those for proposed railroad lines and trade routes, or for general knowledge of the poorly known Western Territories (1840s to 1870s). These explorations were usually conducted under the auspices of the United States Army. Scientists, including geologists/paleontologists, commonly accompanied the survey parties. The first surveys whose prime objectives were to study geology and topography were commissioned by Congress in 1867.
The earliest discovery of a vertebrate fossil in Utah apparently took place on the J. N. Macomb expedition of 1859 (which generally followed the Old Spanish Trail), when J. S. Newberry collected dinosaur bones in the southeastern part of the state. F. V. Hayden's 1870 survey may have extended into northernmost Utah. It is possible that a few of the Eocene age fossils which were reported by him from southernmost Wyoming, came from here. Fossils collected during the Hayden survey prompted a vertebrate fossil collecting trip headed by J. Leidy into the same area two years later. Also in 1870, O. C. Marsh discovered and named the Uinta Basin, making a significant fossil vertebrate collection there. Numerous Eocene mammals as well as reptiles and fish were collected in the Basin proper, while a turtle shell and dinosaur teeth were recovered from the upturned Mesozoic beds on the eastern rim of the Uinta Basin. A Jurassic crocodile humerus was found by Marsh along the eastern flank of the Uinta Mountains. In subsequent years before the turn of the century several institutions sent paleontological parties into this area. E. D. Cope in 1880 identified fossil fish and a crocodile from Eocene deposits of central Utah. Pleistocene mammals were first reported by P. A. Chadbourne (1871) and C. King (1878) from Salt Lake and Utah valleys.
While early expeditions for vertebrate fossils concentrated largely on adjacent states, many of America's prominent 19th Century vertebrate paleontologists collected fossils in Utah. Their work pioneered the way for present-day paleontologists.
A Fundamental Overview of Accelerated Testing Analytical Models
Authors: Caruso Hank , Dasgupta Abhijit 
Published: April 2015

This paper describes analytical models that are commonly used for product life estimation and accelerated life testing. Model descriptions include: Miner's "Rule" for describing accumulated fatigue damage; Coffin-Manson nonlinear power law, often applied to mechanical fatigue damage; Rudra model for CFF failures; Arrhenius steady-state temperature acceleration model for estimating chemical aging effects; Peck's model for accelerated combined temperature-humidity effects; and Kemeny model for combined temperature and voltage acceleration effects.
The general form of these models will be presented along with specific guidance regarding: relative strengths and appropriate applications for each model; limitations and sources of uncertainty for each model; and example values for exponents and material coefficients.
A Sampling System for Measurement of Nanometer-Sized Particles in Hydrogen
Authors: Malczewski Mark , Holmer Arthur , Demmin Hollis 
Published: April 2015

Particle counting in reactive gases such as hydrogen and oxygen utilizing condensation nucleus counter (CNC) technology is now possible with counters such as the CPC 7651 being commercially available. Described here is a sampling system that allows these counters to be used for continuous monitoring in hydrogen and oxygen.
A closed sampling system is described which maintains the inlet of the particle counter at slightly above atmospheric pressure, utilizing sample gas pressure to maintain the proper sample flow rate. This avoids the use of a sampling pump which is a potential ignition source when used with reactive gases. For continuous monitoring applications, refilling of the working fluid during operation is necessary. A pressurized fill system is also described which allows a counter to be refilled against the elevated pressure at the sample inlet. The fill system provides an inert gas above the working fluid and can also be used to refill multiple particle counters.
Use of a Zero-Gravity Suspension System for Testing a Vibration Isolation System
Authors: Idle M. , Cobb R. , Sullivan J. , Goodding J. 
Published: April 2015

The Air Force Research Laboratory team has been confronted with many unique testing challenges in the Ballistic Missile Defense Organization sponsored Vibration Isolation and Suppression System (VISS) performance test program, VISS incorporates a combination passive/active vibration mitigation technology in a Stewart platform configuration to provide a mechanically quiet platform for a medium-wavelength, infrared camera.
VISS actuator stiffnesses, insufficient to support the payload in a l-g field, require a gravity off-load system to simulate the free boundary conditions of space A performance test series characterized the test fixture dynamics, VISS payload dynamics and the open loop control system plant.
Passive performance has been characterized and the active performance measured in the laboratory will be verified when VISS is on-orbit. VISS goals include demonstrating good passive-based vibration isolation at high frequencies, augmenting low-frequency isolation with closed loop control, suppressing an on-board disturbance due to a cryocooler, and demonstrating steering capabilities of the payload with a prescribed amplitude and spectral content.
Investigations of Particle Penetration in Fibrous Filters: Part II. Theoretical
Authors: Dhaniyala Suresh , Liu Benjamin 
Published: April 2015

This article is the second part of a two-part series. The first part, "Investigation of Particle Penetration in Fibrous Filters: Experimental," appeared in the January/February, 1999, issue of the Journal of the IEST.
The performance of seven state-of-the-art air cleaning filter media having a wide range of filter efficiencies is described. The figure of merit values have been obtained to compare the performance of different media. The experimentally obtained pressure drops and the theoretically calculated fiber drags are used in deriving an expression to calculate an equivalent fiber diameter for different media. The theoretical values of fiber diameter compare well with the experimental observations. Use of the equivalent fiber diameter values in calculating the parameters of the dimensionless correlation model results in better agreement between the experiments and theory. The calculated equivalent fiber diameter is useful in predicting the most penetrating particle size of different media.
Internet Data Centers and the Infrastructure Require Environmental Design, Controls, and Monitoring
Authors: Frith Clifford 
Published: April 2015

Internet technology requires new facilities and infrastructure similar to the data centers for mainframe and supercomputers of the early 1990s. Internet Data Centers (IDC) and the infrastructure require environmental design, controls, and monitoring. Specifications and standards need to be developed, and specialists from the environmental sciences with knowledge and skills are valuable resources.
Security and environmental controls, as well as reliable, redundant connectivity and electric power must be monitored and evaluated periodically. Industry standards must be developed to achieve the high level of performance for mission-critical Internet applications.
This presentation provides an overview of systems, processes, monitoring, and controls required to achieve a reliability level of &gt;99.999% to support business-to-business Internet applications.
Realistic Reliability Requirements for Stresses in Use
Authors: Krasich Milena 
Published: April 2015

This study discusses, with examples, the dependency of reliability estimates or requirements on the use environments, including the details of reliability changes of electronic and mechanical components as a function of environmental and operational stresses and of their duty cycles. It also discusses the fundamental differences between product validation and reliability demonstration or assessment. This study shows how the same product used in a different location of a system, e.g., a vehicle, or in a different orientation that affects its natural heat transfer, can yield a very different reliability estimate. For that reason, reliability requirements or goals should be tailored for the actual expected use of the product. Reliability details such as dependency on the product use cannot be numerically tailored at all times for all locations and conditions of use, especially contractually. Therefore, specification of reliability requirements is needed in the form of a reliability range in average conditions, or a minimum reliability under the harshest use profile, rather than a fixed numerical value.
The most excessive environmental and operational stresses are not expected to be constant and ever-present when the product is in actual use. Such stresses are expected to be present for only a fraction of the lifetime of the product; therefore, knowing the use profile is essential to preparing an analysis or designing an accelerated reliability life test. This analysis and the reliability demonstration/growth test should be tailored to cover product use under aggressive, normal, and light stresses depending on the percentage of time spent in each of those environments, and with realistically expected stresses on the product during those times.
To determine realistic and effective reliability goals or requirements, it is necessary to consider the manner in which an item will be used and the environments or locations of its use. Specifying a required value of Mean Time To Failure (MTTF) or Mean Time Between Failures (MTBF) may introduce unwanted problems, as MTTF and MTBF are average values that, just as reliability is, are highly dependent on the use, operational and environmental stresses, and expected life or use duration of the product. It is more appropriate to specify a minimum reliability value for aggressive use in the harshest environment in which the product might be used. This practice is even more important in cases where a product contains not only electronics, but also mechanical components for which MTTF is just an average value calculated from stress/strength criteria and resultant reliability.
Author's Note: References 1 and 2 should be considered foundational documents for this entire study; as such, they are not notated individually within the text.
Novel Guided Head Expander Design Uses Close Coupled Inertial Masses and Hydrostatic Bearings to Minimize Cross-Axis Motion
Authors: Lund Douglas , Crawford Robert 
Published: April 2015

When vertical vibration testing of large test articles is required, it is common to install a head expander on the armature of a shaker. Larger test articles often have a center of gravity relatively far above the mounting surface. When combined with the armature and head expander, these test articles may exhibit multiple structural resonances within the desired test band that do not exist in the intended application. These test configuration-driven characteristics are likely to create unwanted cross-axis excitation during a vibration test.
The difficulty in controlling unwanted cross-axis motion usually increases when testing large items. Excessive cross-axis motion can "over-test" the test item, creating the risk of damaging the test item, or can limit the input in the test axis, thus jeopardizing a successful test.
Orbital Sciences commissioned the design of a guided head expander system that greatly reduces the cross-axis motion at the test article mounting surface of the head expander. The design submitted by Team Corporation couples large inertial masses to the head expander through high-stiffness, hydrostatic, self-aligning bearings. Together, the guided head expander and inertial mass structures have a first resonance higher than the test band of interest and provide high dynamic stiffness. The head expander and inertial masses are supported by a suspension system with a low first resonance, below the test band of interest. It is noteworthy that this design approach exhibits high "dynamic" stiffness and low static stiffness.
Conventional designs for this type of equipment may have relatively high cross-axis load ratings, which might suggest that such designs would provide good cross-axis motion control, but these designs often suffer from structural resonances within the test band of interest that produce unwanted cross-axis motion.
A newer approach in positioning teeth for dental prosthetics using lateral cephalometric, trans-cranial radiographs, and the Denar-Witzig articulator: a case of hypodontia in an adolescent patient
Authors: Chapra Anas , White George 
Published: April 2015

Traditionally in full denture prosthetics, anterior teeth are set on the models, independent of the effects on the face. More enlightened dentists, will then adjust the wax-up for speech, and some effects on the lips. Consideration is infrequently given to restoring the face by repositioning the teeth and mandible. Rarely is thought given to the effects of occlusion on the posture of the body. This report uses several techniques to restore facial esthetics and body posture. The techniques used include a cephalometric radiograph, transcranial radiographs, an articulator that has an adjustable "TMJ" (Denar-Witzig), and Symmetrigraf Posture ChartR.
This clinical report describes a newer approach in the positioning of maxillary anterior teeth for a patient with hypodontia and nail dysplasia syndrome, and the overall effect of this approach on the face and posture of the patient.
Conventionally the precise form of the maxillary wax rim is fabricated with considerable variation from technician to another, based on the technicians training. This variation is evident on the position of the labial aspect of the rim horizontally and vertically. The wax rim is then further adjusted chair side based on subjective evaluation of the face. The maxillary anterior teeth position is established without considering that the lip position is not yet accustomed to the wax rim.
Focal epithlieltal hyperplasia: report of six cases from Ghana, West Africa
Authors: Nartey N. , Newman Merley , Nyako E. 
Published: April 2015

Focal epithelial hyperplasia is a proliferative growth of the oral mucosa with distinct clinical and histopathological features. Although focal epithelial hyperplasia is frequently reported in children of American Indian and Eskimo descent, it is rarely seen in Africans. This report presents six new cases of focal epithelial hyperplasia observed in African children. The age of the patients ranged from 4 to 12 years, and all except one were females. Clinical variants, the papillary and the papular types were noted in the same patient.
There was spontaneous regression of focal epithelial hyperplasia in four patients during the study period. However, the lesions still persist in two patients three years after the initial presentation.
A vacuum-formed splint for luxated tooth with a repositioning on the model
Authors: Horie Norio , Shimoyama T. , Nama Y. , Nasu D. , Kaneko T. 
Published: April 2015

The results of fixation of a luxated tooth using a vacuum-formed splint, formed on a plaster model after repositioning of the luxated tooth on the model are presented. This may be useful where the adjacent tooth gap is wide or only minimal anchorage and support are available from the adjacent teeth.
J Clin Pediatr Dent 29(2): 123-126, 2005