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1

A virtual petrological microscope for teaching and outreach  

Microsoft Academic Search

Learning to use microscopes for geoscience or life science applications is a crucial part of the practical training offered in many science degrees, but the opportunities to study are often constrained by available laboratory space and time, and sometimes constrained by the number of high quality microscopes available. The alternative, although not replacing physical microscopes, offers the opportunity for enhancement

Simon P. Kelley; Peter Whalley; Andrew G. Tindle; Mahesh Anand

2010-01-01

2

Assessment of Petrological Microscopes.  

ERIC Educational Resources Information Center

Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

Mathison, Charter Innes

1990-01-01

3

Virtual Microscope.  

National Technical Information Service (NTIS)

We present the design and implementation of the Virtual Microscope, a software system employing a client/server architecture to provide a realistic emulation of a high power light microscope. The system provides a form of completely digital telepathology,...

U. Catalyurek M. D. Beynon C. Chang T. Kurc A. Sussman

2005-01-01

4

Virtual petrological microscopy: web 2.0 technology for learning microscopy skills outside the laboratory  

Microsoft Academic Search

Learning to use microscopes for geoscience or life science applications is a crucial part of the practical training offered in many science degrees, but the opportunities to study are often constrained by available laboratory space and time, and sometimes constrained by the number of high quality microscopes available. We will demonstrate a new based virtual petrological microscope which offers the

S. P. Kelley; P. Whalley; A. Tindle

2009-01-01

5

The Virtual Microscope.  

PubMed Central

We present the design of the Virtual Microscope, a software system employing a client/server architecture to provide a realistic emulation of a high power light microscope. We discuss several technical challenges related to providing the performance necessary to achieve rapid response time, mainly in dealing with the enormous amounts of data (tens to hundreds of gigabytes per slide) that must be retrieved from secondary storage and processed. To effectively implement the data server, the system design relies on the computational power and high I/O throughput available from an appropriately configured parallel computer. Images Figure 1 Figure 3

Ferreira, R.; Moon, B.; Humphries, J.; Sussman, A.; Saltz, J.; Miller, R.; Demarzo, A.

1997-01-01

6

Virtual pinhole confocal microscope  

SciTech Connect

Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

1999-06-01

7

Virtual Microscope: Light Microscopy Basics  

NSDL National Science Digital Library

This animated tutorial illustrates the basics of light microscopy. It opens with a brief introduction to light refraction and interference. Next, the tutorial explores light microscope anatomy and contrast methods -- including stain, darkfield, and polarized contrast. Finally, it discusses the field of fluorescent light microscopy. This resource is part of the Virtual Microscope project, which provides cost-free simulated scientific instrumentation for students and researchers worldwide as part of NASA's Virtual Laboratory initiative. See Related Materials for links to additional animated tutorials on Atomic Force Microscopy and Scanning Electron Microscopy.

2013-02-11

8

Inquiry based learning with a virtual microscope  

NASA Astrophysics Data System (ADS)

As part of newly funded initiative, the Wolfson OpenScience Laboratory, we are linking a tool for inquiry based learning, nQuire (http://www.nquire.org.uk) with the virtual microscope for Earth science (http://www.virtualmicroscope.co.uk) to allow students to undertake projects and gain from inquiry based study thin sections of rocks without the need for a laboratory with expensive petrological microscopes. The Virtual Microscope (VM) was developed for undergraduate teaching of petrology and geoscience, allowing students to explore rock hand specimens and thin sections in a browser window. The system is based on HTML5 application and allows students to scan and zoom the rocks in a browser window, view in ppl and xpl conditions, and rotate specific areas to view birefringence and pleochroism. Importantly the VM allows students to gain access to rare specimens such as Moon rocks that might be too precious to suffer loss or damage. Experimentation with such specimens can inspire the learners' interest in science and allows them to investigate relevant science questions. Yet it is challenging for learners to engage in scientific processes, as they may lack scientific investigation skills or have problems in planning their activities; for teachers, managing inquiry activities is a demanding task (Quintana et al., 2004). To facilitate the realization of inquiry activities, the VM is being integrated with the nQuire tool. nQuire is a web tool that guides and supports students through the inquiry process (Mulholland et al., 2011). Learners are encouraged to construct their own personally relevant hypothesis, pose scientific questions, and plan the method to answer them. Then, the system enables users to collect and analyze data, and share their conclusions. Teachers can monitor their students' progress through inquiries, and give them access to new parts of inquiries as they advance. By means of the integration of nQuire and the VM, inquiries that involve collecting data through a microscope can be created and supported. To illustrate the possibilities of these tools, we have designed two inquiries that engage learners in the study of Moon rock samples under the microscope, starting from general questions such as comparison of Moon rocks or determining the origin of meteorites. One is aimed at undergraduate Geology students; the second has been conceived for the general public. Science teachers can reuse these inquiries, adapt them as they need, or create completely new inquiries using nQuire's authoring tool. We will report progress and demonstrate the combination of these two on-line tools to create an open educational resource allowing educators to design and run science inquiries for Earth and planetary science in a range of settings from schools to universities. Quintana, C., Reiser, B. J., Davis, E. A., Krajcik, J., Fretz, E., Duncan, R. G., Kyza, E., et al. (2004). A scaffolding design framework for software to support science inquiry. Journal of the Learning Sciences, 13(3), 337-386. Mulholland, P., Anastopoulou, S., Collins, T., FeiBt, M., Gaved, M., Kerawalla, L., Paxton, M., et al. (2011). nQuire: Technological support for personal inquiry learning. IEEE Transactions on Learning Technologies. First published online, December 5, 2011, http://doi.ieeecomputersociety.org/10.1109/TLT.2011.32.

Kelley, S. P.; Sharples, M.; Tindle, A.; Villasclaras-Fernández, E.

2012-12-01

9

Digital Dynamic Telepathology - the Virtual Microscope  

Microsoft Academic Search

The Virtual Microscope is being designed as an inte- grated computer hardware and software system that gen- erates a highly realistic digital simulation of analog, me- chanical light microscopy. We present our work over the past year in meeting the challenges in building such a sys- tem. The enhancements we made are discussed, as well as the planned future improvements.

Michael D. Beynon; Fabian Bustamante; Angelo Demarzo; Renato Ferreira; Robert Miller; Mark Silberman; Joel Saltz; Alan Sussman; Hubert Tsang

1998-01-01

10

Molecular Expressions: Virtual Microscopy - Stereoscopic Zoom Microscope  

NSDL National Science Digital Library

This item is an interactive Java tutorial that simulates an industrial stereoscope with a zoom ratio of 15x. The stereoscopic microscope is designed with two separate optical paths and two eyepieces to produce a 3-D visualization. It is often used to study surfaces of solid materials or to conduct close work such as microsurgery or circuit board inspection. This simulation features diverse specimens including an integrated circuit, a tungsten filament, and a moth wing. It is part of a larger collection of virtual microscopy simulations developed for teachers and learners of introductory optics.

Davidson, Michael

2008-08-23

11

Digital dynamic telepathology--the Virtual Microscope.  

PubMed Central

The Virtual Microscope is being designed as an integrated computer hardware and software system that generates a highly realistic digital simulation of analog, mechanical light microscopy. We present our work over the past year in meeting the challenges in building such a system. The enhancements we made are discussed, as well as the planned future improvements. Performance results are provided showing the system scales well, so that many users can be adequately serviced by an appropriately configured data server. Images Figure 1 Figure 3 Figure 4

Afework, A.; Beynon, M. D.; Bustamante, F.; Cho, S.; Demarzo, A.; Ferreira, R.; Miller, R.; Silberman, M.; Saltz, J.; Sussman, A.; Tsang, H.

1998-01-01

12

Virtual Environment for Manipulating Microscopic Particles with Optical Tweezers.  

National Technical Information Service (NTIS)

In this paper, virtual reality techniques are used to define an intuitive interface to a nanoscale manipulation device. This device utilizes optical methods to focus laser light to trap and reposition nano-to-microscopic particles. The underlying physics ...

Y. G. Lee K. W. Lyons T. W. LeBrun

2003-01-01

13

The Role of the Virtual Microscope in Distance Learning  

ERIC Educational Resources Information Center

Screen-based microscopes allow for a shared visualisation and task-directed conversations that offer significant pedagogic advantages for the science disciplines involving observation of natural samples such as the geosciences and biosciences, and particularly for distance education in these disciplines. The role and development of a virtual

Whalley, Peter; Kelley, Simon; Tindle, Andrew

2011-01-01

14

Construction of a Virtual Scanning Electron Microscope (VSEM)  

NASA Technical Reports Server (NTRS)

The Imaging Technology Group (ITG) proposed to develop a Virtual SEM (VSEM) application and supporting materials as the first installed instrument in NASA s Virtual Laboratory Project. The instrument was to be a simulator modeled after an existing SEM, and was to mimic that real instrument as closely as possible. Virtual samples would be developed and provided along with the instrument, which would be written in Java.

Fried, Glenn; Grosser, Benjamin

2004-01-01

15

Surface modification tools in a virtual environment interface to a scanning probe microscope  

Microsoft Academic Search

The NanoManipulator system has been expanded from a virtual-reality interface for a specific scanning tunneling microscope to include control of atomic force microscopes. The current state of the system is reviewed, and new tools extending the user's feel and control in manipulation and fabrication in the mesoscopic regime are detailed. Manipulations that could not be performed using the techniques available

Mark Finch; Vernon L. Chil; Russell M. Taylor II; Mike Falvo; Sean Washburn; Richard Superfine

1995-01-01

16

Microscope light dimmer for biomedical image enhancement with virtual instrumentation  

Microsoft Academic Search

This paper focuses on high speed video acquisition system designing for biomedical image enhancement. The paper gives information about microscope dimmer using in image analysis. Due to fast digital camera, system contains intelligent illumination dimming hardware automatically regulated through measurement card. Regulating parameter for dimmer (PWM duty cycle) is computed from image features, histogram distribution and intensity relations. Dimming helps

L. Hargas?; D. Koniar; M. Hrianka; S. S?tofan

2010-01-01

17

Enhancing Learning Objectives by Use of Simple Virtual Microscopic Slides in Cellular Physiology and Histology: Impact and Attitudes  

ERIC Educational Resources Information Center

The impact and perception of students on the use of a simple, low technology-driven version of a virtual microscope in teaching and assessments in cellular physiology and histology were studied. Its impact on the time and resources of the faculty were also assessed. Simple virtual slides and conventional microscopes were used to conduct the same…

Anyanwu, Godson Emeka; Agu, Augustine Uchechukwu; Anyaehie, Ugochukwu Bond

2012-01-01

18

Enhancing learning objectives by use of simple virtual microscopic slides in cellular physiology and histology: impact and attitudes  

NSDL National Science Digital Library

The impact and perception of students on the use of a simple, low technology-driven version of a virtual microscope in teaching and assessments in cellular physiology and histology were studied. Its impact on the time and resources of the faculty were also assessed. Simple virtual slides and conventional microscopes were used to conduct the same examinations for the same students. Students performed significantly better in the examination with the virtual slide and also showed a significantly higher preference for virtual slides. The time and cost implications of conducting examinations using the simple virtual slides were reduced by >1,400%. The results reemphasize the need for the design and adoption of simple sustainable technological innovations in developing countries to bridge gaps in purposeful learning environments.

Augustine Uchechukwu Agu (University of Nigeria)

2012-06-01

19

Sedimentary petrology  

SciTech Connect

This is an introductory book to sedimentary petrology and covers the origin, occurrence, mineral composition and texture of sedimentary rocks. The description and interpretation of sedimentary structures, environments and facies are briefly discussed. Chapters cover: the occurrence of sedimentary rocks, formation of sediment, mudrock, conglomerates and sandstones, limestones dolomites, evaporites, cherts, iron-rich, rocks, phosphorites, coal, development of research project and the practice of sedimentary petrology. One chapter has been abstracted separately.

Blatt, H.

1982-01-01

20

Petrology Home  

NSDL National Science Digital Library

This site is a clearinghouse for a variety of educational and supporting materials for teaching igneous and metamorphic petrology. Some features of the site are a collection of classroom and laboratory activities, teaching materials such as lecture notes and Power Point presentations, a database of geochemical instruments available for use at various institutions, a collection of petrology syllabi, and email list discussion groups. These collections reflect the contributions of faculty members from across the country, and will continue to grow as new materials and tools are developed.

21

UNIT, PETROLOGY.  

ERIC Educational Resources Information Center

THIS TEACHER'S GUIDE FOR A UNIT ON PETROLOGY IS SUITABLE FOR ADAPTATION AT EITHER THE UPPER ELEMENTARY OR THE JUNIOR HIGH SCHOOL LEVELS. THE UNIT BEGINS WITH A STORY THAT INTRODUCES VOLCANIC ACTION AND IGNEOUS ROCK FORMATION. SELECTED CONCEPTS ARE LISTED FOLLOWED BY SUGGESTED ACTIVITIES. A BIBLIOGRAPHY, FILM LIST, VOCABULARY LIST, AND QUESTION AND…

Louisiana Arts and Science Center, Baton Rouge.

22

The nanomanipulator: a virtual-reality interface for a scanning tunneling microscope  

Microsoft Academic Search

We present an atomic-scale teleoperation system that uses a head-mounted display and force-feedback manipulator arm for a user interface and a Scanning Tunneling Microscope (STM) as a sensor and effector. The system approximates presence at the atomic scale, placing the scientist on the surface, in control, while the experiment is happening. A scientist using the Nanomanipulator can view incoming STM

Russell M. Taylor II; Warren Robinett; Vernon L. Chi; Frederick P. Brooks Jr.; William V. Wright; R. Stanley Williams; Erik J. Snyder

1993-01-01

23

Development and preliminary evaluation of the VPS ReplaySuite: a virtual double-headed microscope for pathology  

PubMed Central

Background Advances in computing and telecommunications have resulted in the availability of a range of online tools for use in pathology training and quality assurance. The majority focus on either enabling pathologists to examine and diagnose cases, or providing image archives that serve as reference material. Limited emphasis has been placed on analysing the diagnostic process used by pathologists to reach a diagnosis and using this as a resource for improving diagnostic performance. Methods The ReplaySuite is an online pathology software tool that presents archived virtual slide examinations to pathologists in an accessible video-like format, similar to observing examinations with a double-headed microscope. Delivered through a customised web browser, it utilises PHP (Hypertext PreProcessor) to interact with a remote database and retrieve data describing virtual slide examinations, performed using the Virtual Pathology Slide (VPS). To demonstrate the technology and conduct a preliminary evaluation of pathologists opinions on its potential application in pathology training and quality assurance, 70 pathologists were invited to use the application to review their own and other pathologists examinations of 10 needle-core breast biopsies and complete an electronic survey. 9 pathologists participated, and all subsequently completed an exit survey. Results Of those who replayed an examination by another pathologist, 83.3% (5/6) agreed that replays provided an insight into the examining pathologists diagnosis and 33.3% (2/6) reconsidered their own diagnosis for at least one case. Of those who reconsidered their original diagnosis, all re-classified either concordant with group consensus or original glass slide diagnosis. 77.7% (7/9) of all participants, and all 3 participants who replayed more than 10 examinations stated the ReplaySuite to be of some or great benefit in pathology training and quality assurance. Conclusion Participants conclude the ReplaySuite to be of some or of great potential benefit to pathology training and quality assurance and consider the ReplaySuite to be beneficial in evaluating the diagnostic trace of an examination. The ReplaySuite removes temporal and spatial issues that surround the use of double-headed microscopes by allowing examinations to be reviewed at different times and in different locations to the original examination. While the evaluation set was limited and potentially subject to bias, the response of participants was favourable. Further work is planned to determine whether use of the ReplaySuite can result in improved diagnostic ability.

Johnston, Dan J; Costello, Sean P; Dervan, Peter A; O'Shea, Daniel G

2005-01-01

24

The Beginnings of Experimental Petrology  

ERIC Educational Resources Information Center

An account of Van't Hoff's change from theoretical chemistry to petrology provides data on the European intellectual climate of the early 1900's and shows how his work laid the foundation for experimental petrology of hard rocks." (AL)

Eugster, Hans P.

1971-01-01

25

Irreversible thermodynamics in petrology  

SciTech Connect

The formulation of reaction rates and transport rates from the point of view of entropy production can help elucidate petrologic processes. The theory of irreversible thermodynamics relates fluxes of heat or mass linearly to thermodynamic forces (temperature gradients or chemical potential gradients) near equilibrium. A consequence of the general theory of irreversible thermodynamics is that each flux may be influenced by any of the thermodynamic forces. This type of coupling leads to such effects as thermal diffusion, the Soret effect, and uphill diffusion. The theory, however, constrains the number and size of the coupling phenomenological coefficients. Estimates of the coupling phenomenological coefficients enable a calculation of the importance of these coupling effects. The linear theory of irreversible thermodynamics relates the rates of reactions to the free energy difference of the reaction. This relation can be used along with experimental data to obtain the individual rates of reactions in petrology. The behavior of systems far from equilibrium is shown to be different from that near equilibrium. In particular, the formation of spatial patterns so common in petrology, is intimately related to the action of a system, when far from equilibrium. The analysis of Liesegang type models as well as the spatial patterns arising from autocatalytic effects can provide useful insights into the formation of differentiated layering in petrology. (JMT)

Fisher, G.W.; Lasaga, A.C.

1981-01-01

26

Carbon petrology in cometary dust  

NASA Technical Reports Server (NTRS)

Chondritic porous (CP) interplanetary dust particles (IDP's) are collected in the Earth's stratosphere. There exists an extensive database on major and minor element chemistry, stable isotopes, noble gas abundances and mineralogy of many CP IDP's, as well as infrared and Raman spectroscopic properties. For details on the mineralogy, chemistry and physical properties of IDP's, I refer to the reviews by Mackinnon and Rietmeijer (1987), Bradley et al. (1988) and Sandford (1987). Texture, mineralogy (Mackinnon and Rietmeijer, 1987) and chemistry (Schramm et al., 1989; Flynn and Sutton, 1991) support the notion that CP IDP's are a unique group of ultrafine-grained extraterrestiral materials that are distinct from any known meteorite class. Their fluffy, or porous, morphology suggests that CP IDP's probably endured minimal alteration by protoplanetary processes since their formation. It is generally accepted that CP IDP's are solid debris from short-period comets. The evidence is mostly circumstantial but this notion gained significant support based on the comet Halley dust data (Brownlee, 1990). In this paper, I will accept that CP IDP's are indeed cometary dust. The C/Si ratio in CP IDP's is 3.3 times higher than in CI carbonaceous chondrites (Schramm et al. 1989). The intraparticle carbon distribution is heteorogeneous (Rietmeijer and McKay, 1986). Carbon occurs both in oxidized and reduced forms. Analytical electron microscope (AEM) and Raman spectroscopic analyses have shown the presence of several carbon forms in CP IDP's but the data are scattered in the literature. Carbons in cometary CP IDP's are among the most pristine Solar System carbons available for laboratory study. Similar to a recently developed petrological model for the diversity of layer silicates in CP IDP's (Zolensky, 1991) that is useful to constrain in situ aqueous alteration in comets (Rietmeijer and Mackinnon, 1987a), I here present the first effort to develop a petrological concept of carbons in CP IDP's. This concept is useful to constrain comet evolution. I also present the philosophical constraint facing Earth Scientists in studies of protoplanets that require a new approach to cometary dust studies.

Rietmeijer, Frans J. M.

1992-01-01

27

Principles of Metamorphic Petrology  

NASA Astrophysics Data System (ADS)

The field of metamorphic petrology has seen spectacular advances in the past decade, including new X-ray mapping techniques for characterizing metamorphic rocks and minerals, new internally consistent thermobarometers, new software for constructing and viewing phase diagrams, new methods to date metamorphic processes, and perhaps most significant, revised petrologic databases and the ability to calculate accurate phase diagrams and pseudosections. These tools and techniques provide new power and resolution for constraining pressure-temperature (P-T) histories and tectonic events. Two books have been fundamental for empowering petrologists and structural geologists during the past decade. Frank Spear's Metamorphic Phase Equilibria and Pressure-Temperature-Time Paths, published in 1993, builds on his seminal papers to provide a quantitative framework for P-T path analysis. Spear's book lays the foundation for modern quantitative metamorphic analysis. Cees Passchier and Rudolph Trouw's Microtectonics, published in 2005, with its superb photos and figures, provides the tools and the theory for interpreting deformation textures and inferring deformation processes.

Williams, Michael L.

2009-05-01

28

Lunar Global Petrologic Variations  

NASA Astrophysics Data System (ADS)

An initial attempt at producing petrologic province maps of the lunar highlands combined orbital and sample geochemical data in variation diagrams.Three different variation diagrams were produced: Mg* (= 100 Mg/Mg+Fe) vs. [(Th/Ti)c, Al vs. Mg*/(Th/Ti)c, and Fe vs. (Th/Ti)c. ([Th/Ti]c is the ratio of Th to Ti, normalized to the chrondritic ratio for these elements.] Later work applied a ternary diagram approach to look at global lunar petrologic variations. This work used the Fe-(Th/Ti)c technique as this had the most spatial coverage with the available data and also appeared to be adequate at distinguishing between different rock types. In the ternary diagram, the apexes were assigned the average Fe and (Th/Ti), values of ferroan anorthosite, mare basalt, and KREEP rocks. Each apex was assigned a primary color while the center of the triangle was represented by gray. Each point on the lunar surface, covered by the Apollo geochemical instruments, was then assigned a color depending on where in the ternary their composition placed them. The resultant petrologic classification map shows how the petrologic units vary spatially. The main results from this work were as follows: (1) The highlands contain large areas of relatively pure ferroan anorthosite; (2) KREEP/Mg suite rocks represent a small percentage of the upper lunar crust; (3) farside outcrops of KREEP/ Mg suite rocks are associated with areas of crustal thinning, particularly on the floor of South Pole Aitken Basin; (4) the average composition of the highlands is richer in Fe than ferroan anorthosite, which supports the magma ocean hypothesis of crystal formation; and (5) regions of the eastern limb and farside highlands are relatively more mafic than average highlands. These areas have a high density of dark halo craters, supporting the idea that mare volcanism occurred in this region before the end of the heavy bombardment. This earlier work utilized the Apollo gamma and X-ray orbital datasets. These data provided limited coverage of the lunar surface (mostly confined to the equatorial latitudes). The gamma ray instrument covered approximately 19% of the lunar surface while the X-ray only covered 9%. With the Clementine and Lunar Prospector datasets, we now have global maps of Fe, Ti, and Th. Apart from global coverage, another important advantage of the new datasets is higher spatial resolution. The resolution of the Apollo instruments was 15 km for the X-ray and 100 km for the gamma ray. The Fe and Ti maps are derived from the full-resolution Clementine UV-VIS data, i.e., about 250 m/pixel. The resolution of the Th data, obtained by Lunar Prospector's neutron spectrometer, is currently about 150 km, but will be available in the future with a spatial resolution of 60 km. The other improvement provided by the recent lunar missions is the error associated with the data. The errors associated with the Fe, Ti, and Th values obtained by Apollo were 10-25 wt%. The error of the Clementine-derived Fe and Ti values is about 1% while the Th data have an error of about 1 ppm. We intend to investigate the petrologic variations on the Moon at a global scale using the new Clementine and Lunar Prospector elemental maps for Fe, Ti, and Th. We shall use the technique described in Davis and Spudis. An initial study has been undertaken that looks at some regions that were covered by the Apollo geochemistry data. Two mare regions, one in Imbrium and the other in Procellarum, match well with the results using the Apollo data. The highland terrain appears problematic. The calibration of the Th data is based on the assumption of a constant background. This is a valid assumption where Th counts are well above background limits, but as count rates decrease variations in Th concentration are more sensitive to background fluctuations. Eventually we will circumvent this problem by using the lower-altitude (i.e., higher resolution) Prospector data and a calibration derived from deconvolution of the gamma ray spectra with proper attention to background variations. The Th/Ti vs. Fe technique p

Bussey, D. B. J.; Spudis, P. D.; Gillis, J. J.

1999-01-01

29

Petrology of metamorphic rocks  

SciTech Connect

''Petrology of Metamorphic Rocks'' reviews Central European opinions about the origin and formation of metamorphic rocks and their genetic systems, confronting the works of such distinguished European scientists as Rosenbusch, Becke, Niggli, Sander, Eskola, Barth and others with present-day knowledge and the results of Soviet and American investigations. The initial chapters discuss the processes that give rise to metamorphic rocks, and the main differences between regional metamorphism and other types of alterations, the emphasis being laid on the material characteristic of the processes of metamorphism, metasomatism and ultrametamorphism. Further chapters give a brief characterization of research methods, together with a detailed genetic classification based on the division of primary rocks into igneous rocks, sediments and ore materials. The effects of metamorphic alterations and those of the properties of the primary rocks are analyzed on the basis of examples taken chiefly from the Bohemian Massif, the West Carpathians, other parts of the European Variscides, from the crystalline Scandinavian Shelf in Norway and Finland, and from the Alps. Typical examples are documented by a number of charts, photographs and petrographical - particularly petrochemical - data.

Suk, M.

1983-01-01

30

Semantically Enabling Knowledge Representation of Metamorphic Petrology Data  

NASA Astrophysics Data System (ADS)

More and more metamorphic petrology data is being collected around the world, and is now being organized together into different virtual data portals by means of virtual organizations. For example, there is the virtual data portal Petrological Database (PetDB, http://www.petdb.org) of the Ocean Floor that is organizing scientific information about geochemical data of ocean floor igneous and metamorphic rocks; and also The Metamorphic Petrology Database (MetPetDB, http://metpetdb.rpi.edu) that is being created by a global community of metamorphic petrologists in collaboration with software engineers and data managers at Rensselaer Polytechnic Institute. The current focus is to provide the ability for scientists and researchers to register their data and search the databases for information regarding sample collections. What we present here is the next step in evolution of the MetPetDB portal, utilizing semantically enabled features such as discovery, data casting, faceted search, knowledge representation, and linked data as well as organizing information about the community and collaboration within the virtual community itself. We take the information that is currently represented in a relational database and make it available through web services, SPARQL endpoints, semantic and triple-stores where inferencing is enabled. We will be leveraging research that has taken place in virtual observatories, such as the Virtual Solar Terrestrial Observatory (VSTO) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO); vocabulary work done in various communities such as Observations and Measurements (ISO 19156), FOAF (Friend of a Friend), Bibo (Bibliography Ontology), and domain specific ontologies; enabling provenance traces of samples and subsamples using the different provenance ontologies; and providing the much needed linking of data from the various research organizations into a common, collaborative virtual observatory. In addition to better representing and presenting the actual data, we also look to organize and represent the knowledge information and expertise behind the data. Domain experts hold a lot of knowledge in their minds, in their presentations and publications, and elsewhere. Not only is this a technical issue, this is also a social issue in that we need to be able to encourage the domain experts to share their knowledge in a way that can be searched and queried over. With this additional focus in MetPetDB the site can be used more efficiently by other domain experts, but can also be utilized by non-specialists as well in order to educate people of the importance of the work being done as well as enable future domain experts.

West, P.; Fox, P. A.; Spear, F. S.; Adali, S.; Nguyen, C.; Hallett, B. W.; Horkley, L. K.

2012-12-01

31

Soil Under the Microscope Mini-Workshop  

NSDL National Science Digital Library

This mini-workshop is a brief introduction to the use of the polarized light microscope for thin-section analysis of soils, known as micromorphology. It assumes only a rudimentary knowledge of mineralogy and sedimentary petrology. Participants have an opportunity to describe and characterize soils with different properties in thin section. Applications to environmental geology and hydrogeology are also mentioned.

Driese, Steven

32

Petrology and classification of the Garraf, Spain chondrite  

NASA Technical Reports Server (NTRS)

Microscopic and electron microprobe studies indicate that the Garraf meteorite is a highly-recrystallized chondrite of petrologic type 6. Olivine (Fa24.7; PMD 1.1) and low-Ca pyroxene (Fs20.9; PMD 1.1) compositions indicate that it belongs to the L-group. Based on contents of noble gases, pervasive fracturing of silicates, common undulose extinction of olivine and plagioclase, and the lack of melt pockets and maskelynite, Garraf is placed into shock facies b. It is concluded that Garraf is a highly recrystallized L6b chondrite that, after recrystallization, was cataclased and comminuted by shock.

Keil, K.; Conrad, G. H.; King, E. A.; San Miguel, A.

1986-01-01

33

The Poster: A Petrologic Exercise For The Resource-Challenged  

NASA Astrophysics Data System (ADS)

The scientific poster is a common format for transmitting information and can be used as a petrologic exercise that may be particularly beneficial for those programs with limited resources. For example, the Saint Norbert College geology program was founded in 1987 and a traditional geology major established in 1994. We have high quality petrographic microscopes and excellent on-campus computing resources but otherwise lack common facilities such as a rock preparation room and instrumentation for obtaining research quality geochemical data such as XRF or SEM. The petrology poster exercise is designed to mimic the formative stages of a research project from fieldwork through geochemical analysis. A background literature search on a regional rock assemblage, usually suggested by the instructor, is conducted by the students. A specific petrologic aspect, such as the troctolitic portion of the Duluth Complex, is selected for investigation. Fieldwork consists of detailed outcrop and handsample descriptions, with approximately ten samples collected for thin section analysis. Geochemical data is culled from the literature by the instructor and computer modeled by the students using standard petrologic modeling programs such as IGPET. Having characterized the rock in detail, the students make interpretations of their data and more importantly, formulate research questions for future investigation. The final poster summarizes a student's work and is presented to their peers for critique. The goal of this semester-long exercise is to provide a near-professional research experience to the students for limited costs (i.e. site field trip and professional preparation of the thin sections). Additional benefits include: in-depth instruction related to writing an abstract, enhanced computer graphic skills related to poster construction, and a final product that makes an excellent springboard to a senior thesis.

Flood, T. P.

2003-12-01

34

Theoretical petrology. [of igneous and metamorphic rocks  

NASA Technical Reports Server (NTRS)

In the present paper, some areas of growing interest in the American efforts in petrology during the 1975-1978 quadrennium are reviewed. In igneous petrology, studies of structures and thermodynamic properties of silicate melts and of kinetics of igneous processes are in a period of rapid growth. Plate tectonic concepts have had (and will no doubt continue to have) an important influence by focusing interest on specific problems and by providing a framework for the understanding of petrogenesis. An understanding of mantle processes and evolution through the integration of petrological, geophysical, and geochemical constraints has been developed over the past 20 years, and will undoubtedly provide direction for future petrological studies.

Stolper, E.

1979-01-01

35

Lunar breccias, petrology, and earth planetary structure  

NASA Technical Reports Server (NTRS)

Topics covered include: (1) petrologic studies of poikiloblastic textured rocks; (2) petrology of aluminous mare basalts in breccia 14063; (3) petrology of Apollo 15 breccia 15459; (4) high-alumina mare basalts; (5) some petrological aspects of imbrium stratigraphy; (6) petrology of lunar rocks and implication to lunar evolution; (7) the crystallization trends of spinels in Tertiary basalts from Rhum and Muck and their petrogenetic significance; (8) the geology and evolution of the Cayman Trench; (9) The petrochemistry of igneous rocks from the Cayman Trench and the Captains Bay Pluton, Unalaska Island and their relation to tectonic processes at plate margins; and (10) the oxide and silicate mineral chemistry of a Kimberlite from the Premier Mine with implications for the evolution of kimberlitic magma.

Ridley, W. I.

1978-01-01

36

Petrology of the igneous rocks  

NASA Technical Reports Server (NTRS)

Papers published during the 1983-1986 period on the petrology and geochemistry of igneous rocks are discussed, with emphasis on tectonic environment. Consideration is given to oceanic rocks, subdivided into divergent margin suites (mid-ocean ridge basalts, ridge-related seamounts, and back-arc basin basalts) and intraplate suites (oceanic island basalts and nonridge seamounts), and to igneous rocks formed at convergent margins (island arc and continental arc suites), subdivided into volcanic associations and plutonic associations. Other rock groups discussed include continental flood basalts, layered mafic intrusions, continental alkalic associations, komatiites, ophiolites, ash-flow tuffs, anorthosites, and mantle xenoliths.

Mccallum, I. S.

1987-01-01

37

The beginnings of experimental petrology.  

PubMed

Van't Hoff's work constitutes the first systematic contribution to experimental petrology. At all times, the problem was perceived as geologic in nature and the laboratory results were checked against natural assemblages whenever possible. The phase rule was not used, nor, for that matter, was chemical thermodynamics, except for the Van't Hoff equation. However, the work of Van't Hoff and Van Deventer was indirectly involved in the evolution of phase theory by Roozeboom, Van Rijn van Alkemade, and Schreinemakers. Meyerhoffer himself wrote the first text explicitly devoted to the phase rule. The impact of Van't Hoff's study was enormous, but it was restricted to those geologists willing and able to cope with chemistry. Foremost among them were igneous petrologists who had long since accepted chemical arguments for classification purposes. I consider the Geophysical Laboratory program to be the most direct heir of the Van't Hoff approach. Although the shape of that program was formulated independently by Van Hise, Becker, Day, and others, the inspiration they derived from Van't Hoff's successes is clearly acknowledged. The study of the fusion of plagioclases by Day and Allen (41), which directly led to the authorization for the Geophysical Laboratory, was the igneous counterpart of Van't Hoff's low-temperature experimental petrology. On metamorphic petrology, too, Van't Hoff left his mark, with V. M. Goldschmidt acting as his disciple. The interpretation of the Kristiania contact rocks was explicitly based on Van't Hoff's double salt law in preference to the phase rule. Sedimentologists remained unaffected and continued their preoccupation with description and classification. Chemical arguments remained subordinate in their work and of an elementary nature, underscoring the chasm between "hard" rocks and "soft" rocks. This gulf is only now beginning to close as a result of the blossoming of experimental petrology and geochemistry since World War II. At last the generality of the point of view of Gibbs is being accepted. If Van't Hoff's contribution had been appreciated fully at the time, this could have happened 70 years earlier. PMID:17738428

Eugster, H P

1971-08-01

38

Studies of Brazilian meteorites. XIV - Mineralogy, petrology, and chemistry of the Conquista, Minas Gerais, chondrite  

NASA Technical Reports Server (NTRS)

The Conquista chondrite is described and classified as an H4. The mineral composition is reported. H-group classification is based on described microscopic, electron microprobe, and bulk chemical studies. The evidence for petrologic type 4 classification includes the pronounced well-developed chondritic texture; the slight compositional variations in constituent phases; the high Ca contents of pyroxene and the presence of pigeonite; glassy to microcrystalline interstitial material rich in alkalis and SiO2; and twinned low-Ca clinopyroxene.

Keil, K.; Kirchner, E.; Gomes, C. B.; Jarosewich, E.; Murta, R. L. L.

1978-01-01

39

Using Data to Teach Igneous Petrology  

NSDL National Science Digital Library

In order to make connections between the two disparate segments (lecture and laboratory) of a Petrology course; short exercises using real data accompany each laboratory exercise. Three examples are discussed pertain to granites, basalts, and andesites.

Asher, Pranoti M.

40

Sedimentary petrology. 2nd edition  

SciTech Connect

The second edition of Sedimentary Petrology is extensively revised and updated; much effort has been expended to strengthen the weaknesses of the earlier edition, and much of this effort has been successful. It consists of sixteen chapters. Following two introductory chapters (occurrence of sedimentary rocks; weathering and soils), eleven chapters cover the various sedimentary rock types. Coverage is allocated in proportion to their relative abundance and relative ease of study -- three chapters on conglomerates and sandstones (textures and structures, composition, and diagenesis); one on mud rocks; three on carbonates (limestone textures, structures, and environments; limestone mineralogy and diagenesis; and dolostones); and one each on evaporites, cherts, iron-rich rocks, and phosphorites. A novel and useful chapter on paleogeothermometry rounds out the discussion of rocks, followed by chapters on The Development of a Research Project'' and common laboratory methods.

Blatt, H.

1992-01-01

41

APPLICATIONS OF CATHODOLUMINESCENCE OF QUARTZ AND FELDSPAR TO SEDIMENTARY PETROLOGY.  

USGS Publications Warehouse

Cathodoluminescence (CL), the emission of visible light during electron bombardment, was first used in sandstone petrology in the mid-1960's. CL techniques are especially useful for determining the origin and source of quartz and feldspar, two of the most common constituents in clastic rocks. CL properties of both minerals are dependent on their temperature of crystallization, duration of cooling, and/or history of deformation. Detrital quartz and feldspar are typically derived from igneous and metamorphic sources and luminesce in the visible range whereas authigenic quartz and feldspar form at low temperatures and do not luminesce. Quantification of luminescent and non-luminescent quartz and feldspar with the scanning electron microscope, electron microprobe, or a commercial CL device can allow for the determination of origin, diagenesis, and source of clastic rocks when used in conjunction with field and other petrographic analyses.

Ruppert, Leslie, F.

1987-01-01

42

Experimental Petrology and Geochemistry of Volatile-Bearing Silicate Melts.  

National Technical Information Service (NTIS)

The focus of this project is the application of experimental petrology and geochemistry to problems in petrology and geochemistry, with particular emphasis on understanding the behavior and properties of the principal volatile components, H2O and CO2, and...

E. Stolper

2013-01-01

43

Microscope Webquest  

NSDL National Science Digital Library

Work with your table partner to complete this activity about using microscopes. Visit the following links to complete the worksheet given to you. A-Z Microscope History Microbus - History of the Microscope What in the World - National Geographic games Magnification Model Powers of 10 If you finish you may return to the What in the World - National Geographic games ...

Smith, Mrs.

2011-02-17

44

A detailed petrological analysis of hydrated, low-nickel, nonchondritic stratospheric dust particles  

NASA Technical Reports Server (NTRS)

A detailed petrological analysis of three low-Ni, K-bearing, nonchondritic stratospheric dust particles is performed, and these particles are compared to products of high-energy, explosive (Plinian-type) volcanic events. The analytical electron microscope (AEM) analyses show pervasive layer silicates, carbonate and goethite, and chemical fractionation in the matrix of these particles similar to hydrothermal alteration in volcanic ejecta. Along with low Ni content and the presence of potassium, the texture and mineralogy of particles L2001-18, L2001-20, and L2002 C2 are similar to at least two nonchondritic stratospheric dust particles of the igneous subgroup for which an extraterrestrial origin has been suggested based on their minor- and trace-element abundances. The petrological characteristics of some low-Ni, K-bearing nonchondritic stratospheric dust particles supports a probable terrestrial volcanic origin, but the AEM data alone cannot exclude an extraterrestrial origin for these particles.

Rietmeijer, Frans J. M.

1992-01-01

45

Virtual Reality  

NASA Technical Reports Server (NTRS)

This video presentation discusses how virtual reality enables scientists to 'explore' other worlds without leaving the laboratory. The applicability of virtual reality for scientific visualization is also discussed.

1991-01-01

46

Petrology and geochemistry of Antarctic micrometeorites  

Microsoft Academic Search

The petrology and geochemistry of twentythree chondritic dust particles with masses of 1-47 g (sizes 100-400 m) were recovered from blue ice near Cap Prudhomme, Antarctica, and studied by INAA, ASEM, EMPA, and optical microscopy. Sample selection criteria were irregular shape and (for a subsample) black color, with the aim of studying as many unmelted micrometeorites (MMs) as possible. Of

Gero Kurat; Christian Koeberl; Thomas Presper; Franz Brandstätter; Michel Maurette

1994-01-01

47

Volcanology, geochemistry, and petrology 1979–1982  

Microsoft Academic Search

This introduction to the Volcanology, Geochemistry and Petrology (VGP) section of the 1979–1982 IUGG Quadrennial Report is intended to serve as a thumbnail sketch of some major research developments and trends in VGP over the past four years. These notes are drawn from, and limited to, the nine review articles which follow in this section. While I have made an

David E. James

1983-01-01

48

Athena microscopic Imager investigation  

USGS Publications Warehouse

The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on the end of an extendable instrument arm, the Instrument Deployment Device (IDD). The MI was designed to acquire images at a spatial resolution of 30 microns/pixel over a broad spectral range (400-700 nm). The MI uses the same electronics design as the other MER cameras but has optics that yield a field of view of 31 ?? 31 mm across a 1024 ?? 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 66 mm), allowing concave surfaces to be imaged in good focus. Coarse focusing (???2 mm precision) is achieved by moving the IDD away from a rock target after the contact sensor has been activated. The MI optics are protected from the Martian environment by a retractable dust cover. The dust cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500-700 nm, allowing color information to be obtained by taking images with the dust cover open and closed. MI data will be used to place other MER instrument data in context and to aid in petrologic and geologic interpretations of rocks and soils on Mars. Copyright 2003 by the American Geophysical Union.

Herkenhoff, K. E.; Squyres, S. W.; Bell, III, J. F.; Maki, J. N.; Arneson, H. M.; Bertelsen, P.; Brown, D. I.; Collins, S. A.; Dingizian, A.; Elliott, S. T.; Goetz, W.; Hagerott, E. C.; Hayes, A. G.; Johnson, M. J.; Kirk, R. L.; McLennan, S.; Morris, R. V.; Scherr, L. M.; Schwochert, M. A.; Shiraishi, L. R.; Smith, G. H.; Soderblom, L. A.; Sohl-Dickstein, J. N.; Wadsworth, M. V.

2003-01-01

49

Virtual Exhibitions  

Microsoft Academic Search

This case study is designed to provide readers with an overview of the format of a virtual event and the variety of options available to exhibitors. It focuses specifically on the Virtual GITEX 2001 event, which adopted a 3-dimensional virtual reality approach. On October 7, 2001, the virtual component of the Dubai World Trade Centre's largest and most successful exhibition,

Janice Edgar

2002-01-01

50

Virtual Courseware: Drosophila  

NSDL National Science Digital Library

In this virtual lab exercise, students can discover and apply principles of genetic inheritance by studying fruit flies (Drosophila) in an interactive online environment. The exercise allows them to order fruit fly mutants from a web merchant, mate the flies in an incubator, anesthetize flies for observation, examine them under a microscope, and analyze the data from offspring to determine patterns of inheritance. Notes and experimental data can be saved online in a virtual notebook and used to generate a report. The exercise concludes with an online quiz, and alignments to state and national standards are included.

51

Magmas and magmatic rocks: An introduction to igneous petrology  

SciTech Connect

This book melds traditional igneous petrology with the emerging science of planetary petrology to provide an account of current ideas on active magmatic and volcanic processes, drawing examples from all igneous provinces of the world as well as from the moon and planets. It reviews the history and development of concepts fundamental to modern igneous petrology and includes indepth sections on magmas, magnetic differentiation and volcanology.

Middlemost, E.A.K.

1986-01-01

52

Virtual reality  

Microsoft Academic Search

Although the terms cyberspace and virtual reality have been around for years, virtual reality as an industry is in its infancy. The term virtual reality is credited to Jaron Lanier, founder of VPL Research; earlier experimenters, like Myron Krueger in the mid-1970s, used phrases like artificial reality. William Gibson coined cyberspace in his 1984 science fiction novel. Neuromancer. Few technologies

C. Machover; S. E. Tice

1994-01-01

53

Virtual time  

Microsoft Academic Search

Virtual time is a new paradigm for organizing and synchronizing distributed systems which can be applied to such problems as distributed discrete event simulation and distributed database concurrency control. Virtual time provides a flexible abstraction of real time in much the same way that virtual memory provides an abstraction of real memory. It is implemented using the Time Warp mechanism,

David R. Jefferson

1985-01-01

54

Microscopic Polyangiitis  

PubMed Central

Synopsis In 1923, Friedrich Wohlwill described two patients with a “microscopic form of periarteritis nodosa”, which was distinct from classical polyarteritis nodosa. This disease, now known as microscopic polyangiitis (MPA), is a primary systemic vasculitis characterized by inflammation of the small-caliber blood vessels and the presence of circulating antineutrophil cytoplasmic antibodies (ANCA). Typically, microscopic polyangiitis presents with glomerulonephritis and pulmonary capillaritis, although involvement of the skin, nerves, and gastrointestinal tract is not uncommon. Treatment of MPA generally requires use of a cytotoxic agent (such as cyclophosphamide) in addition to high-dose glucocorticoids. Recent research has focused on identifying alternate treatment strategies that minimize or eliminate exposure to cytotoxic agents. This article will review the history, pathogenesis, clinical manifestations, and treatment of MPA.

Chung, Sharon A.; Seo, Philip

2010-01-01

55

Virtual sound for virtual reality.  

National Technical Information Service (NTIS)

The computational limitations of real-time interactive computing do not meet our requirements for producing realistic images for virtual reality in a convincing manner. Regardless of the real-time restrictions on virtual reality interfaces, the representa...

M. M. Blattner A. L. Papp

1993-01-01

56

Cosmic petrology and the planetary evolution of the Solar System  

Microsoft Academic Search

Cosmic petrology, whose origin was triggered by astronomic discoveries at the turn of the twenty-first century, now plays a pivotal role in the `compositional' interpretation of the results of extraterrestrial observations. Cosmic petrology is able to play this role owing to the experience gained in studying meteorites and, in particular, chondrites, which display preserved traces of their two-stage evolution. The

A. A. Marakushev

2005-01-01

57

Martian Microscope  

NASA Technical Reports Server (NTRS)

The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

2004-01-01

58

Microscopic colitis.  

PubMed

Microscopic colitis is an idiopathic chronic inflammatory bowel disease presenting with watery diarrhea. While colonoscopy and radiology findings are normal, the colon shows striking pathologic findings, including lymphocytic colitis and collagenous colitis. The clinical course is usually benign with sustained remission. Recent medical evidence shows that bismuth and budesonide are effective treatments. PMID:15326829

Delgado, Jorge; Delgado, Bertha; Fich, Alex; Odes, Shmuel

2004-08-01

59

Microscope objectives.  

PubMed

The objective is the most crucial image-forming component of a microscope. A knowledge of the many types of objectives available and their characteristics is critical to the selection of appropriate objectives for image cytometry. This unit discusses aberrations in image formation and their correction, construction, and types of objectives, and objectives for other microscopy applications, explaining the advantages and limitations of each one. PMID:21965106

LoBiondo, Joseph; Abramowitz, Mortimer; Friedman, Marc M

2011-10-01

60

Virtual Neuron  

NSDL National Science Digital Library

Neurons are able to communicate with each other using biochemicals called neurotransmitters. Use Virtual Neuron to explore neurotransmitter properties, make neurons fire, and manipulate neural circuits.

2009-04-14

61

Using Dynamic Digital Maps to Teach Petrology  

NSDL National Science Digital Library

In this session we will examine how to utilize Dynamic Digital Maps (DDMs) in undergraduate petrology courses to bring inaccessible and exciting volcanic field areas to the students in the classroom and to engage the students in authentic research experiences. A DDM is a stand-alone "presentation manager" computer program that contains interactive maps, analytical data, digital images and movies. They are essentially complete geologic maps in digital format, available on CD-ROM and on line. We have developed two different kinds of exercises that use DDMs to provide field-based context for undergraduate research projects in petrology. In one, the students use the DDM of the Tatara-San Pedro volcanic complex of the Andes Mountains of central Chile to develop a group research poster on part of the volcano's evolution, to present to the class, modeled after what would be presented at a national meeting. The second exercise focuses on the Springville Volcanic field, where the students try to understand the magma evolution using both field relations and quantitative modeling skills. Read a complete description of how dynamic digital maps work, with more ideas for the classroom. (from Teaching with Data, Simulations and Models)

Condit, Christopher D.

62

Electronic Blending in Virtual Microscopy  

ERIC Educational Resources Information Center

Virtual microscopy (VM) is a relatively new technology that transforms the computer into a microscope. In essence, VM allows for the scanning and transfer of glass slides from light microscopy technology to the digital environment of the computer. This transition is also a function of the change from print knowledge to electronic knowledge, or as…

Maybury, Terrence S.; Farah, Camile S.

2010-01-01

63

Virtual Laboratories and Virtual Worlds  

NASA Astrophysics Data System (ADS)

Since we cannot put stars in a laboratory, astrophysicists had to wait till the invention of computers before becoming laboratory scientists. For half a century now, we have been conducting experiments in our virtual laboratories. However, we ourselves have remained behind the keyboard, with the screen of the monitor separating us from the world we are simulating. Recently, 3D on-line technology, developed first for games but now deployed in virtual worlds like Second Life, is beginning to make it possible for astrophysicists to enter their virtual labs themselves, in virtual form as avatars. This has several advantages, from new possibilities to explore the results of the simulations to a shared presence in a virtual lab with remote collaborators on different continents. I will report my experiences with the use of Qwaq Forums, a virtual world developed by a new company (see http://www.qwaq.com).

Hut, Piet

2008-05-01

64

Virtual Memory  

Microsoft Academic Search

\\\\The need for automatic storage allocation arises from desires for program modularity, machine independence, and resource sharing. Virtual memory is an elegant way of achieving these objectives. In a virtual memory, the addresses a program may use to identify information are distinguished from the addresses the memory system uses to identify physical storage sites, and program-generated addresses are translated automatically

Peter J. Denning

1970-01-01

65

Virtual Time  

Microsoft Academic Search

Virtual time is a broad, new paradigm for organizing and synchronizing distributed systems, subsuming such heretofore distantly related problems as distributed discrete event simulation and distributed database concurrency control. It is an abstraction of real time in much the same way that virtual memory is an abstraction of real memory, and it reorganizes the concepts of concurrency and synchronization in

David Jefferson

1983-01-01

66

Virtual mantis  

NSDL National Science Digital Library

3D virtual image of a mantis (Family Mantidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

67

Virtual flea  

NSDL National Science Digital Library

3D virtual image of a flea (Order Siphonaptera). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

68

Virtual mosquito  

NSDL National Science Digital Library

3D virtual image of a mosquito (Family Culicidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

69

Virtual fly  

NSDL National Science Digital Library

3D virtual image of a blow fly (Family Calliphoridae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

70

Virtual grasshopper  

NSDL National Science Digital Library

3D virtual image of a grasshopper (Family Acrididae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

71

Virtual bee  

NSDL National Science Digital Library

3D virtual image of a honey bee (Family Apidae *spelled Apiidae in the image caption*). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

72

Virtual termite  

NSDL National Science Digital Library

3D virtual image of a termite (Order Isoptera). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

73

Microscope and method of use  

SciTech Connect

A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

Bongianni, W.L.

1981-08-18

74

Petrology and Bulk Chemistry of R Chondrites: New Data  

NASA Astrophysics Data System (ADS)

New INAA data show that R chondrites of all petrologic types are isochemical. R3 PRE 95411 contains numerous awaruite grains; R6 Y 980702 has a fine-grained granoblastic matrix; MET 01149 is reclassified as R3.

Isa, J.; Rubin, A. E.; Wasson, J. T.

2010-03-01

75

Geochemical, Mineralogical and Petrological Relationships in Enstatite Chondrites  

NASA Astrophysics Data System (ADS)

The geochemical, mineralogical, and petrological properties of enstatite chondrites reflect nebular processes that produced reduced precursors and collisional events on their parent bodies that caused wide-spread melting, brecciation, and annealing.

Rubin, A. E.

2008-03-01

76

Lunar composition - A geophysical and petrological synthesis  

NASA Astrophysics Data System (ADS)

Lunar compositional constraints are derived on the basis of geophysical data (in particular, the lunar seismic model as revised by Nakamura) and petrological arguments. Only in the case of extreme assumptions can critical aspects of bulk lunar composition be demonstrated to be equivalent to the present-day terrestrial mantle; specifically, the moon has an Mg number that is too low and an alumina abundance that is too high. Over a broad range of crustal densities the presence of a metallic core at least 150 km in radius is necessary to reconcile the upper mantle lunar seismic model with mass and moment of inertia constraints. A significant seismic discontinuity at 500 km depth may mark the lowest extent of early lunar differentiation, possibly representing a transition between highly fractionated upper mantle and less fractionated, perhaps even primordial, middle/lower mantle.

Mueller, S.; Taylor, G. J.; Phillips, R. J.

1988-06-01

77

Petrology, Geochemistry and Genesis of Ureilites  

NASA Technical Reports Server (NTRS)

Ureilites are enigmatic achondrites that have some characteristics resulting from high temperature igneous processing, yet retain other characteristics inherited from the solar nebula. They are basalt-depleted ultramafic rocks containing 7-66 mg/g elemental C. They are rich in noble gases and display a correlation between mg# and Delta (17)O. This mishmash of properties has engendered various models for ureilite genesis, from those in which nebular processes dominate to those in which parent body igneous processes dominate. Characterization of new ureilites, especially of new subtypes, is an important part of attempts to unravel the history of the ureilite parent body or bodies. Here we report on the petrology and geochemistry of a suite of ureilites, mostly from Antarctica, and use these data to discuss ureilite petrogenesis. Additional information is included in the original extended abstract.

Mittlefehldt, D. W.; Hudon, Pierre; Galindo, Charles, Jr.

2005-01-01

78

Virtual seminars  

NASA Astrophysics Data System (ADS)

A virtual seminar (SM) is an economic and effective instructional tool for teaching students who are at a distance from their instructor. Like conventional class room teaching, a virtual seminar requires an instructor, a student, and a method of communication. Teleconferencing, video conferencing, intranets and the Internet give learners in a Virtual Seminar the ability to interact immediately with their mentors and receive real and relevant answers. This paper shows how industry and academia can benefit from using methods developed and experience gained in presenting the first virtual seminars to academic and petroleum industry participants in mid-1996. The information explosion in industry means that business or technical information is worthless until it is assimilated into a corporate knowledge management system. A search for specific information often turns into a filtering exercise or an attempt to find patterns and classify retrieved material. In the setting of an interactive corporate information system, virtual seminars meet the need for a productive new relationship between creative people and the flux of corporate knowledge. Experience shows that it is more efficient to circulate timesensitive and confidential information electronically through a virtual seminar. Automating the classification of information and removing that task from the usual work load creates an electronic corporate memory and enhances the value of the knowledge to both users and a corporation. Catalogued benchmarks, best-practice standards, and Knowledge Maps (SM) of experience serve as key aids to communicating knowledge through virtual seminars and converting that knowledge into a profit-making asset.

Nelson, H. Roice

1997-06-01

79

Altering petrology through microbial dissimilatory phosphite oxidation  

NASA Astrophysics Data System (ADS)

Microbial enhanced oil recovery (MEOR) takes advantage of various microbial metabolisms to increase hydrocarbon and energy yield by improving oil flow and flood water sweep in a reservoir during tertiary recovery. Wormholing at the injection well is believed to be the result of the large drop in pressure when water exits the injection well and enters the unconsolidated reservoir matrix. One possible means of prevent this event is to consolidate the rock matrix immediately around the injection well to create a permeable zone of stable petrology. Many microbial processes are known to result in the precipitation of ionic components into their environment creating solid-phase minerals. Such processes could be judiciously applied to bind unconsolidated matrices in order to form a permeable concreted rock matrix, which would minimize wormholing events and thus improve floodwater sweep. However, to date, apart from the application of urea oxidation creating calcium carbonate precipitation, there has been little investigation of the applicability of these precipitated bioconcretions to MEOR strategies and none to control wormholing events. Here we present a novel approach to altering rock petrology to concrete unconsolidated matrices in the near well environment by the biogenesis of authigenic minerals through microbial dissimilatory phosphite oxidation. Desulfotignum phosphitoxidans, strain FiPS-3 is currently the only isolated organism capable of using phosphite (HPO32-) as an electron donor for growth. This process, known as dissimilatory phosphite oxidation (DPO), can be coupled to either sulfate reduction or homoacetogenesis and leads to the accumulation of inorganic phosphate in the medium. The resulting insoluble mineral phases can coat the rock environment resulting in a concretion binding the unconsolidated matrix particles into a single phase. In this study we demonstrate that DPO can effectively produce calcium or magnesium phosphate minerals in packed glass bead mini-columns and could potentially be applied to create a concretion binding the unconsolidated matrix particles into a single phase.

Zhu, H.; Figueroa, I.; Coates, J. D.

2013-12-01

80

Virtually Hawaii  

NSDL National Science Digital Library

Virtually Hawaii is provided by researchers at the University of Hawaii, Proxemy Research, Terra Systems, and private company sponsors. Visitors can explore virtual field trips of the Hawaiian Islands, participate in remote sensing tutorials, work with an interactive spectral imager, view space and aircraft images, and more. The virtual field trip of the "big island" includes a simulated flight, a ground tour, a kids tour, and a link to six ways to enjoy Kilauea Volcano. An interesting and informative site, everyone from kids to grandparents will enjoy its content and ease of use.

81

Virtual Wonders  

NSDL National Science Digital Library

The British Natural History Museum has posted this site, which features a selection of fossils, meteorites, and other specimens that can be rotated and viewed in virtual reality. Each specimen is accompanied by a brief text description and links to additional information. This is a collection of strange and interesting virtual objects, most of which the viewer will not find in galleries. Virtual Wonders include a fossil ammonite, Anomalocaris model, Archaeopteryx skull, Coccolithopore, Radiolarian model, land snail shell, meteorite fragments, a two-faced sheep skull, fossil seashell, microfossil, specimen jar, surface of Mars, and trilobites.

82

Virtual Dating  

NSDL National Science Digital Library

This is an interactive exercise about Geologic Time. It focuses on how geologists and archaeologists determine the ages of rocks and ancient artifacts. This is a beta release of an instructional activity still under development. Virtual Dating contains two modules as well as a demonstration version. One module is Virtual Dating Isochron for rocks and minerals and the other is Virtual Dating Radiocarbon (Carbon-14). The interactive modules involve the students in exploring data and background information and answering questions as they move through the activity. An answer checking and feedback function is employed. There is also a Virtual Dating Demo if you want to do a quick run-through of the activity without answer checking enabled.

Novak, Gary

1999-04-01

83

[Microscopic polyarteritis].  

PubMed

The microscopic polyarteritis is a vasculitis related to necrotizing glomerolunephritis. It always damages at renal and systemic level (a third of the cases presented hemorrhage alveolar). We have showed a case that took place with hemoptysis and renal progressive insufficiency. Among the patient antecedents, we can find arterial hypertension hematuria, rhinitis, epistaxis and artromyalgias. Just before his admittance it showed edemas on lower limbs and eyelids, dysnea, severe hemoptysis, paresthesias and general malaise. The immunologic analysis: Acs. glomerular basal antimembrane: negative, ANCA positive with antimieloperoxidasa specificity. The renal biopsy: focal necrotizing glomerulonephritis with semilunar and negative immunofluorescent. The nasas biopsy: unspecified chronic rhinitis. From the clinic point of view, the patient seemed to have the Wegener granulomatosis apart from the fact that he had hemoptysis which is a rare sign in this cases. However, we could not find any granuloma anatomopatologically, which did not clarify this diagnosis. We diagnosed microscopis Poliarteritis, as a third of the cases presented intrapulmonary haemorrhage. Moreover the renal damage it is identical than in the in Wegener granulomatosis. On the top of that, often we can find p-ANCA, which confirms the diagnosis in 99% of cases. Despite our doubt according to the diagnosis the therapeutical treatment of both illnesses is nowadays identical. This means that we were able to begin a precocious treatment with plasmapheresis, metilprednisolona and ciclofosfamida. After a week treatment there was an evident improvement. Five moth later the illness relapsed. PMID:8924553

de Ancos Aracil, C; Rebollar Mesa, J L

1995-09-01

84

Virtual Museums and Virtual Realities  

Microsoft Academic Search

The notion of virtual museum is discussed and related to various developments in user-interface, software, and communications technology. A prototype implementation, intended to explore the integration of interactive 3d graphics with video imagery is described.

Dennis Tsichritzis; Simon J. Gibbs

1991-01-01

85

Magnetic petrology of eastern North America diabases. I - Olivine-normative dikes from western South Carolina  

NASA Technical Reports Server (NTRS)

The oxide mineralogy and the magnetic behavior of 15 olivine-normative samples obtained from South-Caroline diabase dikes were investigated using electron microprobe and SEM analyses and measurements of natural remanence magnetization (NRM), saturation isothermal remanence magnetization (SIRM), and anhysteritic remanence magnetization. It was found that chromite (which for these olivine-normative diabases is a sensitive petrologic indicator) constitutes up to 0.5 vol pct and that its abundance and composition correlate with bulk rock Cr. Microscopic analyses showed that titanomagnetite compositions were mostly between 0.4 and 0.55. The values of NRM and the NRM/SIRM ratios varied between 4 and 0.01 A sq m/kg and 0.0019 and 0.032, respectively. These properties inversely correlate with Cr content and demonstrably contrast Cr-rich and Cr-poor samples.

Warner, Richard D.; Wasilewski, Peter J.

1990-01-01

86

Virtual microscopy in virtual tumor banking.  

PubMed

Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated virtual microscope systems can be acquired, with the capability to quickly scan large batches of glass slides at high magnification and compress and store the large images on disc, which subsequently can be consulted through the Internet. The images are stored on an image server, which can give simple, easy to transfer pictures to the user specifying a certain magnification on any position in the scan. This offers new opportunities in histology review, overcoming the necessity of the dynamic telepathology systems to have compatible software systems and microscopes and in addition, an adequate connection of sufficient bandwidth. Consulting the images now only requires an Internet connection and a computer with a high quality monitor. A system of complete pathology review supporting biorepositories is described, based on the implementation of this technique in the European Human Frozen Tumor Tissue Bank (TuBaFrost). PMID:17163157

Isabelle, M; Teodorovic, I; Oosterhuis, J W; Riegman, P H J; Passioukov, A; Lejeune, S; Therasse, P; Dinjens, W N M; Lam, K H; Oomen, M H A; Spatz, A; Ratcliffe, C; Knox, K; Mager, R; Kerr, D; Pezzella, F; Van Damme, B; Van de Vijver, M; Van Boven, H; Morente, M M; Alonso, S; Kerjaschki, D; Pammer, J; López-Guerrero, J A; Llombart-Bosch, A; Carbone, A; Gloghini, A; Van Veen, E B

2006-01-01

87

Virtual Hospital  

NSDL National Science Digital Library

Provided and maintained by the University of Iowa Health Care, the Virtual Hospital is designed as a "medical reference and health promotion tool for health care providers and patients." To that end, the site offers current and authoritative medical information for patients and professional and pedagogical information for health care providers. The former includes patient educational briefs browseable by organ system or by a topical list, a collection of peer-reviewed and annotated Web resources, an internal search engine, and archives of a column offering medical advice to middle-aged users. Resources in the health care provider section include several digital libraries aimed at certain specialties (Pediatrics, Pediatric Radiology, Family Medicine, and Medical Student); multimedia textbooks and teaching files grouped by organ system; lectures and publications; and clinical practice guidelines. Additional resources at the site include links to the Virtual Children's and Virtual Naval Hospitals, an internal search engine, and online continuing education courses.

1999-01-01

88

Virtual Labs  

NSDL National Science Digital Library

These virtual labs from the Howard Hughes Medical Institute allow students to experience laboratory procedures as if they were a professional scientist. Students can isolate and analyze bacterial DNA sequences, examine cardiac patients, dissect a leech, or diagnose diseases by detecting the presence of antibodies. These virtual labs include animated steps that must be performed, along with textual instructions and explanations so that students understand not only what they are doing, but also why they are doing it. This is an extensive Web site that offers a lot to learn, and a chance to have fun in the process.

1969-12-31

89

Virtual Skies  

NSDL National Science Digital Library

Produced by NASA for use in high schools and flight technology programs, Virtual Skies explores the worlds of aviation technology, air traffic management, and current research. The site includes information on aeronautics, navigation, weather, air traffic management, communications, airport design and related careers.

Conrad, Linda

2011-09-22

90

Virtual Schooling  

ERIC Educational Resources Information Center

Virtual schooling, in which K-12 courses and activities are offered mostly or completely through digital communication technologies, has become firmly established in K-12 education across the United States. The VS movement continues to expand at a rapid rate, especially at the high school level. The continuing success of VS efforts will require…

Davis, Niki; Niederhauser, Dale S.

2007-01-01

91

Virtual Economy  

NSDL National Science Digital Library

Launched February 26, 1999, Virtual Economy (VE) is an Institute for Fiscal Studies (IFS), Biz/ed, and Economic and Social Research Council (ESRC-UK) learning tool based on the UK governmental model for economic forecasting and planning. This elaborate site contains a "floor plan" for constructing a functional budget and is complete with teacher and student guides, case studies, and model details.

1999-01-01

92

Virtually There.  

ERIC Educational Resources Information Center

Describes tele-immersion, a new medium for human interaction enabled by digital technologies. It combines the display and interaction techniques of virtual reality with new vision technologies that transcend the traditional limitations of a camera. Tele-immersion stations observe people as moving sculptures without favoring a single point of view.…

Lanier, Jaron

2001-01-01

93

Virtual Electromagnet  

NSDL National Science Digital Library

This is an interactive online activity, in which learners equip a virtual electromagnet and see how many iron filings it can pick up. Learners change various characteristics of the electromagnet including the number of windings, the gage of the wire, the current type (AC or DC), the material used in the wire, and the voltage on the power supply.

Regents, The U.

2014-01-01

94

Virtual colonoscopy  

Microsoft Academic Search

Virtual colonscopy (VC) is an evolving technique that combines volume scanning and computer visualization methods to enable minimally invasive and effective colorectal cancer screening. Although VC offers significant clinical and public health advantages over conventional endoscopic screening, several issues confront VC's emergence into the medical marketplace.

David J Vining

1999-01-01

95

The petrographic microscope: Evolution of a mineralogical research instrument  

USGS Publications Warehouse

The petrographic microscope, designed to observe and measure the optical properties of minerals as a means of identifying them, has provided a foundation for mineralogical and petrological research for more than 120 years. Much of what is known today in these fields is attributable to this instrument, the development of which paralleled an evolution of fundamental optical theory and its correlation with mineral structure and composition. This instrument and its related accessories have evolved through a range of models and designs, which are in themselves distinctive for their scientific function and elegant construction, and are today prized by collectors of scientific instruments.

Kile, D. E.

2003-01-01

96

Is Virtual Reality Virtually Here?  

ERIC Educational Resources Information Center

Virtual reality, a three-dimensional simulation technology, may best be used (1) when training mistakes would be costly; (2) when the environment cannot be experienced in the real world; (3) to improve human-machine interfaces; (4) to make training situations real; and (5) to make the perceptible imperceptible. (SK)

Carr, Clay

1992-01-01

97

Virtual Autopsy  

NSDL National Science Digital Library

Designed with medical students in mind, Leicester (England) University's Virtual Autopsy site takes the student on a virtual tour of seven autopsies. Several options allow for efficient navigation of the site: Cause of Death is a self-assessment quiz students may take after "performing" each autopsy; Return to History takes the user back to the beginning of each case; and Choose another Case lets the user move between the seven cases. Each case contains nearly a dozen detailed color images of certain key parts (including tissues) of the human anatomy--lung, body, heart, head--with hyperlinks to further information. By clicking on the dictionary icon, for instance, a student links to a pop-up page with detailed descriptions of that particular condition. Aspiring pathologists are sure to find this worthwhile, and the absence of gruesome images makes it a good learning site for many budding medical scientists as well.

Verma, Ajay M.

2008-10-10

98

Virtual Sojourner  

NSDL National Science Digital Library

This module has students carry out a virtual Mars mission similar to Pathfinder's rover, the Sojourner. Students work in teams, concentrating on specific mission needs, such as engineering, camera, navigation, or science. The activities in this module simulate the Mars Pathfinder mission objectives and structure. The purpose of this module is for students to work collaboratively to map, invent, and solve navigation problems with a 'remote' classroom.

Edgerton, Richard; Tillman, James

99

Virtual Mirrors  

NASA Astrophysics Data System (ADS)

The multiple-reflection photograph in Fig. 1 was taken in an elevator on board the cruise ship Norwegian Jade in March 2008. Three of the four walls of the elevator were mirrored, allowing me to see the combination of two standard arrangements of plane mirrors: two mirrors set at 90° to each other and two parallel mirrors. Optical phenomena of this complexity are most easily approached by the Method of Virtual Mirrors.1

Greenslade, Thomas B.

2010-01-01

100

Virtual Sky  

NSDL National Science Digital Library

The Virtual Sky Viewer is sponsored by The Center for Advanced Computing Research at the California Institute of Technology and the Microsoft Corporation. The Web site allows users to view "stunning, seamless images of the night sky; not just an album of popular places, but the entire northern sky at high resolution". Although reading the help link before attempting to use the viewer is recommend, the powerful application gives fascinating and unique views of the sky that most people have never seen. >.

101

Virtual Antarctica  

NSDL National Science Digital Library

Provided by Terraquest.com, the Virtual Antarctica Web site presents a ship's expedition to the continent and describes what is found along the way. The science portion describes such things as the geology, geography, and climate of the area, as well as various biological features of the land and water. Other sections of the site contain information on Antarctica's history and ecology, as well as other resources such as a glossary and map.

1995-01-01

102

Virtual Geoengineer  

NSDL National Science Digital Library

The site presents specific topics in geoengineering practice through photos, maps, diagrams, and videos using texts. Materials found in the Virtual Geoengineer include: photos with details of projects, case histories, photos of different construction methods with explanations and equipment used in construction, and construction issues on specific projects. Topics covered include: geology, earthquake engineering, foundations, excavation, in-situ testing, dams, geosynthetics, landslides, and slope failures.

2008-09-23

103

Virtual Volcano  

NSDL National Science Digital Library

The Discovery Channel's website has several interactive features on volcanoes to complement its programs on Pompeii. At the homepage, visitors can explore a virtual volcano, by clicking on "Enter". The virtual volcano has several components. The first is a quickly revolving globe with red triangles and gray lines on it that represent active volcanoes and plate boundaries. Clicking on "Stop Rotation", located next to the globe, will enable a better look. Visitors can also click one of the topics below the globe, to see illustrations of "Tectonic Plates", "Ring of Fire" (no, not the Johnny Cash song), and "Layers Within". Visitors can click on "Build your Own Volcano and Watch it Erupt" on the menu on the left side of the page, where they will be given a brief explanation of two factors that affect the shape and explosiveness of volcanoes: viscosity and gas. Then they must choose, and set, the conditions of their volcano by using the arrows under the viscosity and gas headings, and clicking on "Set Conditions", underneath the arrows. Once done, a description of the type of volcano created will be given, and it's time to "Start Eruption". While the lava flows, and the noise of an eruption sounds, terms describing various features of the volcano are superimposed on the virtual volcano, and can be clicked on for explanations.

104

Virtual automation.  

PubMed

Total laboratory automation (TLA) can be substituted in mid-size laboratories by a computer sample workflow control (virtual automation). Such a solution has been implemented in our laboratory using PSM, software developed in cooperation with Roche Diagnostics (Barcelona, Spain), to this purpose. This software is connected to the online analyzers and to the laboratory information system and is able to control and direct the samples working as an intermediate station. The only difference with TLA is the replacement of transport belts by personnel of the laboratory. The implementation of this virtual automation system has allowed us the achievement of the main advantages of TLA: workload increase (64%) with reduction in the cost per test (43%), significant reduction in the number of biochemistry primary tubes (from 8 to 2), less aliquoting (from 600 to 100 samples/day), automation of functional testing, drastic reduction of preanalytical errors (from 11.7 to 0.4% of the tubes) and better total response time for both inpatients (from up to 48 hours to up to 4 hours) and outpatients (from up to 10 days to up to 48 hours). As an additional advantage, virtual automation could be implemented without hardware investment and significant headcount reduction (15% in our lab). PMID:11299911

Casis, E; Garrido, A; Uranga, B; Vives, A; Zufiaurre, C

2001-01-01

105

Virtual Reality and the Virtual Library.  

ERIC Educational Resources Information Center

Explains virtual reality, including proper and improper uses of the term, and suggests ways that libraries might be affected by it. Highlights include elements of virtual reality systems; possible virtual reality applications, including architecture, the chemical industry, transport planning, armed forces, and entertainment; and the virtual

Oppenheim, Charles

1993-01-01

106

Mineralogy and Petrology of New Antarctic Nakhlite MIL 03346  

NASA Technical Reports Server (NTRS)

Among the approx.1300 meteorites returned from Antarctica by the 2003-2004 ANSMET expedition was a 715g nakhlite, MIL 03346, recovered from the Miller Range. Samples of this meteorite were distributed to investigators on December 16, 2004. We were allocated PTS MIL 03346,63,100. This abstract is our preliminary report on the mineralogy and petrology of this important new sample.

McKay, G.; Schwandt, C.

2005-01-01

107

Petrology of 79215 - Brecciation of a lunar cumulate  

NASA Technical Reports Server (NTRS)

The paper considers the modal variation and bulk composition, the petrography, and the mineral chemistry of lunar sample 79215, a holocrystalline, nearly monomict breccia that is petrologically and chemically distinct from the majority of lunar highland breccias. The bulk composition of the rock and its REE abundances suggest that the precursor was a plagioclase-olivine cumulate.

Bickel, C. E.; Warner, J. L.; Phinney, W. C.

1976-01-01

108

A Simulated Research Problem for Undergraduate Metamorphic Petrology.  

ERIC Educational Resources Information Center

Presents a laboratory problem in metamorphic petrology designed to simulate a research experience. The problem deals with data on scales ranging from a geologic map to hand specimens to thin sections. Student analysis includes identifying metamorphic index minerals, locating their isograds on the map, and determining the folding sequence. (BC)

Amenta, Roddy V.

1984-01-01

109

Petrology of a Transform Fault Zone and Adjacent Ridge Segments  

Microsoft Academic Search

The Vema Fracture Zone in the North Atlantic (9 to 11 degrees N), which has been identified as a transform fault zone, contains exposures of serpentinized peridotites, while its adjacent ridge segments are floored mainly by typical abyssal ocean ridge basalts. This petrologic contrast correlates with the greater frequency of volcanic eruptions along the actively spreading ridge segments compared to

W. G. Melson; G. Thompson

1971-01-01

110

Estimation of parameters in petrologic materials balance equations  

Microsoft Academic Search

A rigorous treatment of the least-squares estimation of the parameters in petrologic materials balance equations is developed to take into account the uncertainties inherent in the chemical analyses. The choice of the optimal estimation procedure for a particular problem is dependent upon the extent of the petrogenetic understanding of the exact nature of the materials balance involved. Some of the

N. H. Gray

1973-01-01

111

Petrological cycles and caldera-forming events  

NASA Astrophysics Data System (ADS)

Many caldera-forming events can be framed within broad petrological cycles; volcanic stratigraphy typically defines a trend from mafic to more silicic magmas with time, culminating in the catastrophic evacuation of an upper crustal reservoir filled with the silicic magma, followed by a return to the eruption of more mafic magmas shortly after caldera collapse. Understanding how such cycles develop has clear implications for characterizing the current state of an active system. Here, we focus on a detailed examination of the well-exposed Quaternary Kos-Nisyros eruptive sequence (eastern Aegean arc) to frame a potential model for such cycles. On the basis of zircon U/Th/Pb ages, building the upper crustal magma chamber large enough to induce caldera collapse required at least a few hundred thousand years. This timeframe is necessary not only for the accumulation of large amounts of viscous, gas-rich silicic magma, but also to heat the upper crust sufficiently to allow the developing reservoir to be maintained above the solidus. In the Kos-Nisyros volcanic center, small eruptions precede the caldera-forming event and mark this period of thermal maturation as the system transitions from intermediate to silicic magma, reaching the most-evolved state only shortly prior to the caldera-forming event, the Kos Plateau Tuff (> 60 km3 of volatile-rich, high-silica rhyolite). The Kos Plateau Tuff was then followed by small-volume eruptions of more mafic magma (basaltic andesite, andesite, and dacites) that are characterized by a drier mineral assemblage. With time, the system transitioned back to cold, wet, high-SiO2 rhyolite. We suggest that the changes in magma composition and mineralogy following the caldera-forming event are due to a near-complete crystallization of the non-erupted mush in the upper crustal reservoir as it is abruptly decompressed during eruption. This rapid crystallization (1) leads to the formation of a porphyritic texture in the crystalline residual - a feature frequently observed in shallow intrusions and (2) allows new inputs of more mafic magmas to reach the surface. With time, these recharge events re-establish an evolved upper crustal reservoir, starting a new cycle. This study shows that detailed spatial and temporal evaluations of the geochemical variations from volcanic complexes have the ability to provide valuable information on the 'state' of a particular magmatic system. In turn, this can assist in selecting which volcanic complexes are most worthy of installing expensive, dense seismic arrays to improve our imaging of the subsurface and better determining the volume of eruptible magmas beneath them.

Bachmann, O.; Deering, C. D.

2012-12-01

112

Thermal and Petrologic Environments of ETS  

NASA Astrophysics Data System (ADS)

ETS events in the Cascadia and Nankai subduction zones are distributed over large distances along strike but in map view are confined to a narrow zone around the tip of the mantle wedge. Reports of similar events from Costa Rica are also consistent with this picture. In Mexico where the mantle wedge “tip” is not distinctly defined because of a flatly lying slab, ETS-type events are less narrowly confined. We have developed numerical thermal models with dislocation-creep mantle rheology for many subduction zones to investigate the thermal and petrologic environments of ETS. Slab subduction always results in a temperature condition that allows serpentine mineral antigorite to be stable in parts of the forearc mantle wedge. But the degree of mantle wedge serpentinization depends on the cumulative availability of fluids from slab dehydration. For Cascadia and Nankai, slab dehydration peaks beneath the most seaward part of the mantle wedge and thus provides ample fluids for its serpentinization. The tip of the wedge, with a diminishing vertical dimension, is expected to be fully serpentinized in both subduction zones. A state of full serpentinization allows fluids from the dehydrating slab to stay as interstitial free fluids. The free fluids and serpentinites can both alter the mechanical behaviour of the plate interface and surrounding rock volume, giving rise to ETS. For Cascadia where subduction has taken place for a much longer time than in Nankai, a much wider portion of the mantle wedge corner is expected to have attained a high degree of serpentinization. This may explain why the width of the ETS band in Cascadia is much wider than in Nankai, as seen in both the tremor distribution in map view and the width of the slip zones inferred from geodetic measurements. The Mexico subduction zone has a similarly warm thermal state. A thin layer of highly serpentinized mantle material between the continental crust and the flatly lying slab may be responsible for the observed tremor and slip distribution. In Costa Rica, metamorphic dehydration of the slab peaks at a greater depth, but the extraordinarily hydrated state of the incoming slab may facilitate full serpentinization of the wedge tip. Sparse tremor in California appears to occur around the Moho depth, and it may be associated with the formerly serpentinized mantle wedge when the margin was a subduction zone.

Wang, K.; Wada, I.; Jiangheng, H.

2009-12-01

113

El Jorullo Revisited: Petrology, Geochemistry & Volcanology  

NASA Astrophysics Data System (ADS)

El Jorullo (western Trans Mexican Volcanic Belt) was produced by a monogenetic eruption between 1759 and 1774. It and Paricutin are the only two historic cones of the nearly 1000 volcanoes in the Michoacan-Guanajuato volcanic field. In a seminal study, Luhr & Carmichael (CMP 90, 1985) demonstrated that El Jorullo lavas erupted from a few cones along a 4km long NE-SW trending fissure and in a compositional sequence from mafic calc-alkaline basalts to basaltic andesites (SiO2, Al2O3, MgO = 53, 16.8, 8.6 and 55.4, 19, 4, wt % respectively). They divided the lavas into 3 flow units and concluded on primarily mineralogic and major element grounds that the compositional evolution was due to crystal fractionation at lower crustal/upper mantle depths. They ruled out a significant role for crustal assimilation. Our recent field observations include a new interpretation of the flow field (8 flow units) and a greater proportion of late stage lavas. New petrologic, petrographic and radiogenic isotope (Sr, Nd, Pb) data have been collected. Major/trace element trends are similar to Luhr & Carmichael (1985), although the new sampling and flow unit subdivision reveals a smoother compositional evolution in time, akin to Paricutin. The earliest flow units (1-3) erupted relatively uniform mafic compositions comprising about half of the flow field volume; middle sequence lavas (units 4, 5) are slightly more evolved, account for 12% of the flow field volume and commonly contain partially melted/disaggregated crustal xenoliths (granodiorite and tonalite); latest, most evolved lavas (units 6-8) show greater compositional shifts both internally and relative to earlier units, and account for 35% of the erupted lava volume. The lavas are sparsely phyric and xenocrysts (plag, rare sphene and quartz) occur mainly in later state lavas. Variations in Sr and Pb isotope and trace element ratios throughout the sequence require up to 15% crustal assimilation and ˜25% crystal fractionation (AFC) relative to the mafic parent. The large volume fraction of the more contaminated late stage magma and the extent of the compositional shifts suggest that assimilation is a primary control on erupted magma compositions, much like at Paricutin (e.g., McBirney et al. CMP 95, 1987).

Rubin, K. H.; Jurado-Chichay, Z.; Pyle, D.; Morán-Zenteno, D.; Rowland, S.

2004-12-01

114

Mesosiderites: A Chronologic and Petrologic Synthesis  

NASA Astrophysics Data System (ADS)

Recent petrologic, chemical, and isotopic analyses of mesosiderite clasts and whole rocks allow construction of the evolutionary history of the mesosiderite parent body (MPB) as shown in the figure. I. Initial Melting ~4.56 Ga Ago. Numerous chronologic measurements indicate that initial melting of the MPB occurred shortly after accretion, at about the same time that the eucrites and angrites formed. For example, a zircon grain from a basaltic clast in Vaca Muerta yielded a Pb-Pb age of 4.563 Ga (Ireland and Wlotzka, 1992). The 4.56-Ga event on the MPB is probably responsible for forming the monogenic basaltic clasts that compositionally resemble typical eucrites (Rubin and Mittlefehldt, 1992). II. Crustal Remelting ~4.47 Ga Ago. Internal Sm-Nd isochron ages of 4.47 Ga have been determined for gabbroic pebble 12 from Vaca Muerta and a basaltic clast from Mt. Padbury (Stewart et al., 1991). Pebble 12 is one of many clasts in mesosiderites that are highly depleted in incompatible elements and probably represent remelted crustal rocks (Rubin and Mittlefehldt, 1992). Because variation of Fe/Mn with Fe/Mg in pyroxenes from these clasts follows a trend defined by FeO reduction from a melt (Mittlefehldt, 1990), and because the reducing agents (e.g., P) were likely to have been introduced during metal-silicate mixing, the age of pebble 12 indicates that metal-silicate mixing had to have occurred >=4.47 Ga ago. III. Localized Impact Melting 4.5-3.9 Ga Ago. Localized impact melting and metamorphism were widespread on the eucrite parent body as indicated by many ages that were partially or totally reset <4.56 Ga ago. Impact melt material is common in mesosiderites of all petrologic types, and ages between 4.5-3.9 Ga are preserved. Quench-textured pebble 5 from Vaca Muerta, which is likely to have formed from a localized impact melt of material resembling a cumulate eucrite (Rubin and Jerde, 1987), has an internal isochron age of 4.42 Ga (Stewart et al., 1992). The high temperature of these localized events places them before the 3.9-Ga event (below); however, because no extensive crustal remelting is evident, the metamorphism must have occurred after 4.47 Ga ago. The mesosiderite breccias were assembled during this phase of MPB history. IV. Collisional Disruption and Reassembly ~3.9 Ga Ago. Mesosiderites were degassed by a major thermal event ~3.9 Ga ago that heated the rocks to ~500 degrees C; this event may mark collisional disruption and gravitational reassembly of the MPB (Bogard et al., 1990). The surface breccias were deeply buried at this time and heated somewhat above the Fe-Ni solvus, resetting the metallographic cooling rates to ~1 degree C/Ma. This event may also account for some of the reported disturbances in the Rb- Sr, Sm-Nd, and Pb-Pb ages of a few mesosiderites. V. Impact Excavation and Ejection <<3.9 Ga Ago. Mesosiderites have cosmic ray exposure ages ranging from ~10-150 Ma, which represent the epoch when individual mesosiderites were excavated from the MPB or from a >=10-m-size MPB fragment. References: Bogard D.D., Garrison D.H., Jordan J.L. and Mittlefehldt D. (1990) Geochim. Cosmochim. Acta 54, 2549-2564. Ireland T.R. and Wlotzka F. (1992) Earth Planet. Sci. Lett. 109, 1-10. Mittlefehldt D.W. (1990) Geochim. Cosmochim. Acta 54, 1165-1173. Rubin A.E. and Jerde E.A. (1987) Earth Planet. Sci. Lett. 84, 1-14. Rubin A.E. and Mittlefehldt D.W. (1992) Geochim. Cosmochim. Acta 56, 827-840. Stewart B.W., Cheng Q.C., Papanastassiou D.A. and Wasserburg G.J. (1991) Lunar Planet. Sci. (abstract) 22, 1333. Stewart B.W., Papanastassiou D.A. and Wasserburg G.J. (1992) Lunar Planet. Sci. (abstract) 23, 1365.

Rubin, A. E.; Mittlefehldt, D. W.

1992-07-01

115

Virtual impactor  

DOEpatents

A virtual impactor is described having improved efficiency and low wall losses in which a core of clean air is inserted into the aerosol flow while aerosol flow is maintained adjacent to the inner wall surfaces of the focusing portion of the impactor. The flow rate of the core and the length of the throat of the impactor's collection probe, as well as the dimensional relationships of other components of the impactor adjacent the separation region of the impactor, are selected to optimize separation efficiency. 4 figs.

Yeh, H.C.; Chen, B.T.; Cheng, Y.S.; Newton, G.J.

1988-08-30

116

Virtual Education: Where Are We?  

ERIC Educational Resources Information Center

Discusses development of virtual education, including potential and caveats. Describes three virtual school programs: Massachusetts Virtual Education Space, Florida Virtual School, and Star Schools, a federal program. (PKP)

Veitch, James; Tu, Pikuei

2001-01-01

117

Data-driven Science in Geochemistry & Petrology: Vision & Reality  

NASA Astrophysics Data System (ADS)

Science in many fields is increasingly ';data-driven'. Though referred to as a ';new' Fourth Paradigm (Hey, 2009), data-driven science is not new, and examples are cited in the Geochemical Society's data policy, including the compilation of Dziewonski & Anderson (1981) that led to PREM, and Zindler & Hart (1986), who compiled mantle isotope data to present for the first time a comprehensive view of the Earth's mantle. Today, rapidly growing data volumes, ubiquity of data access, and new computational and information management technologies enable data-driven science at a radically advanced scale of speed, extent, flexibility, and inclusiveness, with the ability to seamlessly synthesize observations, experiments, theory, and computation, and to statistically mine data across disciplines, leading to more comprehensive, well informed, and high impact scientific advances. Are geochemists, petrologists, and volcanologists ready to participate in this revolution of the scientific process? In the past year, researchers from the VGP community and related disciplines have come together at several cyberinfrastructure related workshops, in part prompted by the EarthCube initiative of the US NSF, to evaluate the status of cyberinfrastructure in their field, to put forth key scientific challenges, and identify primary data and software needs to address these. Science scenarios developed by workshop participants that range from non-equilibrium experiments focusing on mass transport, chemical reactions, and phase transformations (J. Hammer) to defining the abundance of elements and isotopes in every voxel in the Earth (W. McDonough), demonstrate the potential of cyberinfrastructure enabled science, and define the vision of how data access, visualization, analysis, computation, and cross-domain interoperability can and should support future research in VGP. The primary obstacle for data-driven science in VGP remains the dearth of accessible, integrated data from lab and sensor measurements, experiments, and models, both from past and from present studies, and their poor discoverability, interoperability, and standardization. Other deficiencies include the lack of widespread sample curation and online sample catalogs, and broad community support and enforcement of open data sharing policies and a strategy for sustained funding and operation of the cyberinfrastructure. In order to achieve true data-driven science in geochemistry and petrology, one of the primary requirements is to change the way data and models are managed and shared to dramatically improve their access and re-usability. Adoption of new data publication practices, new ways of citing data that ensure attribution and credit to authors, tools that help investigators to seamlessly manage their data throughout the data life cycle, from the point of acquisition to upload to repositories, and population of databases with historical data are among the most urgent needs. The community, especially early career scientists, must work together to produce the cultural shift within the discipline toward sharing of data and knowledge, virtual collaboration, and social networking. Dziewonski, A M, & Anderson, D L: Physics of the Earth and Planet Interiors 25 (4), 297 (1981) Hey, T, Tansley, S, Tolle, K (Eds.): Redmond, VA: Microsoft Research (2009) Zindler, A, & Hart, S R: Ann. Rev. Earth Plan. Sci. 14, 493 (1986)

Lehnert, K. A.; Ghiorso, M. S.; Spear, F. S.

2013-12-01

118

Virtual Norfolk  

NSDL National Science Digital Library

An experiment in teaching with historical texts still in the early stages of development, Virtual Norfolk (Norfolk County, UK) offers five content modules that include seminars, topics, and illustrative documents. For example, the Social History of Early Modern England module includes the Everyday Lives seminar, which has among its topics Crime and the Law, where one can read the digitized version of "prosecution of Benet Goodwyn for whoring" from Norwich City Records, City Quarter Sessions, Book of Examinations and Depositions, 1561-67. Some introductory sections and commentaries have yet to be written by project staff, scholars from the University of East Anglia, and the glossary "will appear here shortly." Although parts of the site are still under construction, all historical texts are searchable by keyword; so, it is quite easy for users to broaden a search after looking over a few documents and discovering terms of interest.

2001-01-01

119

Virtual Laboratory  

NSDL National Science Digital Library

The website for the Virtual Laboratory contains a bold and direct statement: "Conventional teaching all too often accepts memorization and pattern recognition as true learning" After reading this statement, it makes sense that the goal of this site is "to help students to recognize, confront, correct, and expand their understanding of subject or a technique." The site contains five different sets of course materials that use interactive materials, short quizzes, and embedded demonstrations to assist students and teachers alike. One set of materials that should not be missed is in the Teaching & Learning Biology area. Here visitors will find links, fact sheets, and pedagogical suggestions for teaching a college-level biology course. Moving on, the Chemistry, Life, the Universe and Everything section contains a new perspective on how to reform the garden-variety general chemistry course.

2012-04-30

120

TEAM Electron Microscope Animation  

SciTech Connect

The TEAM Electron Microscope, a device that enables atomic-scale imaging in 3-D, has a rotating stage that can hold and position samples inside electron microscopes with unprecedented stability, position-control accuracy, and range of motion.The TEAM Stage makes one of the world's most powerful electron microscopes even better, and enables previously impossible experiments.

None

2012-01-01

121

Lunar and Planetary Science XXXV: Martian Meteorites: Petrology  

NASA Technical Reports Server (NTRS)

The session "Martian Meteorites: Petrology: included the following reports:Volatile Behavior in Lunar and Terrestrial Basalts During Shock: Implications for Martian Magmas; Problems with a Low-Pressure Tholeiitic Magmatic History for the Chassigny Dunite; Fast Cooling History of the Chassigny Martian Meteorite; Rehomogenized Interstitial and Inclusion Melts in Lherzolitic Shergottite ALH 77005: Petrologic Significance; Compositional Controls on the Formation of Kaersutite Amphibole in Shergottite Meteorites; Chemical Characteristics of an Olivine-Phyric Shergottite, Yamato 980459; Pb-Hf-Sr-Nd Isotopic Systematics and Age of Nakhlite NWA 998; Noble Gases in Two Samples of EETA 79001 (Lith. A); Experimental Constraints on the Iron Content of the Martian Mantle; and Mars as the Parent Body for the CI Carbonaceous Chondrites: New Data.

2004-01-01

122

Petrology and pairing of mesosiderites from Victoria Land, Antarctica  

NASA Technical Reports Server (NTRS)

Petrological data on mesosiderites from Reckling Peak (RKP) and Allan Hills (ALH), Antarctica, are presented. The results suggest that the Allan Hills mesosiderites A77219, A81059, and A81098 are probably paired (being of similar texture, modes, and mineral composition), and ALHA 81208 is, most likely, a clast from one of these mesosiderites. RKPA 80258 is a weakly poikilitic plagioclase-poor mesosiderite, completely different from ALHA 77219, 81059, and 81098. On the other hand, RKPA 79015, 80229, 80246, and 80263 are very similar, belonging to subgroup C diogenitic mesosiderites. These mesosiderites contain orthopyroxene and recrystallized orthopyroxenite clasts in a metal-troilite matrix. The silicate fraction of mesosiderites ranged from diogenitic (RKPA 79015) to analogous to polymict eurcrite (Dyarrl Island). On the basis of petrologic data, the mesosiderite subdivision scheme was amended, making it possible to classify the formerly 'anomalous' RKPA 79015.

Hewins, Roger H.

1988-01-01

123

Virtual metering for Virtual PHEV aggregation  

Microsoft Academic Search

Technically sustainable solutions for integration of (PH)EVs in Smart Grid emerge as an important concern. We discuss the need for introduction of Virtual Aggregations supported by implementation of Virtual Meters in power system structures. We advocate our proposal with an evaluation of scenarios based on realistic data. The structure and functionalities of the Virtual Aggregator, as well as proposed enhancements

Slobodan Lukovic; Igor Kaitovic; Srdan Vukmirovic; Aleksandar Erdeljan

2012-01-01

124

Virtual studio: virtual reality in art  

Microsoft Academic Search

Virtual Reality or VR is a computer-designed environment that allows the user to interact within the digital environment as he or she would in a real world situation. VR has been successfully used in game development, medical technology and flight simulation. Virtual Studio is a partial immersive, interactive virtual learning environment that is based on the metaphor of the artist

DaShawn L. Hall; Kenneth Sakatani

2002-01-01

125

Petrologic, geochemical and experimental constraints on models of chondrule formation  

Microsoft Academic Search

The petrologic and geochemical properties of chondrules as well as results of experimental studies provide strong constraints on chondrule-formation models. Nebular formation is indicated by the non-mass-fractionated oxygen isotopic compositions of bulk chondrules. Chondrule formation from a melt is required by the prototypical spheroidal shapes and the presence of euhedral phenocrysts and glassy mesostases. Incomplete melting is indicated by the

Alan E. Rubin

2000-01-01

126

Petrology of impactites from Lake St. Martin structure, Manitoba  

NASA Technical Reports Server (NTRS)

The 23-km Lake St. Martin crater was produced 200 to 250 million years ago in Archean granitic to amphibolic gneiss, overlain by 400 to 500 m of Ordovician to Devonian limestone and dolomite. In the present paper, a schematic model of the field geology, petrology, and geochemistry is presented. The scenario is built in part on the calculations of Kieffer and Simonds and observations made on the Lake St. Martin structure.

Simonds, C. H.; Mcgee, P. E.

1979-01-01

127

Petrologic province maps of the lunar highlands derived from orbital geochemical data  

NASA Astrophysics Data System (ADS)

It is shown that the orbital geochemical data of the moon can be used in geochemical variation diagrams like those employed in lunar sample studies to define petrologic units within the highlands, to determine their geologic interrelations, and to address problems of crustal genesis on a near-global scale. Three variation diarams based on Apollo geochemical data were examined: Mg(asterisk) versus (Th/Ti)c, Al versus Mg(asterisk)/(Th/Ti)c, and Fe versus (Th/Ti)c. The diagrams show some units of virtually pure anorthosite and norite; most units show the effects of mixing of pristine rock types in the regolith. One unit, which dominates the eastern limb and farside highlands, has a composition so mafic that, with the chosen end members, it requires a 30 percent mare basalt component. This is interpreted to mean that the highlands experienced a significantly greater amount of mare volcanism before the end of heavy bombardment than has previously been suggested.

Davis, P. A.; Spudis, P. D.

1985-11-01

128

FLASK-SG: A program to compute chemical equilibria in metamorphic petrology  

NASA Astrophysics Data System (ADS)

Chemical equilibrium calculation program for metamorphic petrology, FLASK-SG, was written for Unix variants (Linux, IRIX, Tru64 UNIX). It is also ported to Windows 95/98. The user specifies a temperature, pressure, and substance amounts (in moles of any chemical formula in C-H-O-Si-Al-Ti-Fe-Mn-Mg-Ca-Na-K system) to this program, then it calculates the stable mineral assemblage, mineral amounts, and gas composition under the given conditions using Gibbs free energy minimization method with the Holland and Powell (1990) data set. Searching algorithm for the stable mineral assemblage is the Metropolis Monte Carlo method. The coding language is C++, and experimental object oriented programming style is adopted to make the main program part as a class library. Model-dependent functions such as fugacity coefficients and activities are implemented as virtual methods of the "systems" class, so they can be easily changed as methods of inherited class from the "systems" class. These characteristics are aimed for a future "simulation kit".

Takeno, Naoto

2001-12-01

129

Chemistry and petrology of Apollo 12 drive tube 12027  

NASA Technical Reports Server (NTRS)

Papike et al. (1982) have provided a summary of previous petrologic and chemical studies of the lunar regolith, taking into account samples from all of the Apollo and Luna sites. On the basis of these studies, an understanding is obtained of the processes which form and characterize the lunar regolith. It is found that comminution of local lithologies by meteorite impact and soil mixing are the most important regolith-forming processes. On the basis of grain size studies of Apollo 14 surface, trench, and drive tube soils, Simin et al. (1982) and Laul et al. (1982) concluded that comminution of local lithologies and vertical soil mixing processes are most important in the formation of the soils at that site. In the present investigation, this study of chemistry and petrology of lunar soils is extended to the Apollo 12 drive tube 12027. This drive tube provides an opportunity to study lunar soil from a depositional environment involving a location at the rim of a crater. The chemical and petrologic data are found to be consistent and suggest three stratigraphic units in the 12027 core.

Smith, M. R.; Laul, J. C.; Simon, S. B.; Papike, J. J.

1985-01-01

130

Exploration petrology of Sunoco Felda trend of south Florida  

SciTech Connect

The Sunoco Felda oil trend of the South Florida basin has been a prolific oil producer. All the oil is produced from the Cretaceous Sunniland formation, a leached limestone bioherm. Although the producing section has been considered reefal in the literature, petrographic and biostratigraphic analyses of various cores in producing fields have determined that these deposits are composed of particles of fragmented rudist and other fauna deposited in a tidal shoal. Atop this debris an algae and gastropod section has been deposited, typical of a mound deposited on a tidal mud flat. This model is exemplified in the Sunoco Felda and West Sunoco fields and was used in exploring the Sunoco Felda trend. From the petrological analysis of these two fields and from knowledge of other wells in the basin, biostratigraphic and lithologic trends can be determined and extended offshore into the eastern Gulf of Mexico. The author stresses petrology in exploring the Sunniland formation because correlating like responses on electric logs does not always result in correlating the same depositional facies - in fact, correlating like electric log responses in the Sunniland formation often results in correlating different facies. This study endeavors to analyze the Felda trend based on the petrological and petrophysical information obtained from the cores and logs. The author will show that the potential of the Sunniland formation may be greater than expected and that it may be the site of future major discoveries.

Mitchell-Tapping, H.

1986-09-01

131

Chemistry and petrology of Apollo 12 drive tube 12027  

NASA Astrophysics Data System (ADS)

Papike et al. (1982) have provided a summary of previous petrologic and chemical studies of the lunar regolith, taking into account samples from all of the Apollo and Luna sites. On the basis of these studies, an understanding is obtained of the processes which form and characterize the lunar regolith. It is found that comminution of local lithologies by meteorite impact and soil mixing are the most important regolith-forming processes. On the basis of grain size studies of Apollo 14 surface, trench, and drive tube soils, Simin et al. (1982) and Laul et al. (1982) concluded that comminution of local lithologies and vertical soil mixing processes are most important in the formation of the soils at that site. In the present investigation, this study of chemistry and petrology of lunar soils is extended to the Apollo 12 drive tube 12027. This drive tube provides an opportunity to study lunar soil from a depositional environment involving a location at the rim of a crater. The chemical and petrologic data are found to be consistent and suggest three stratigraphic units in the 12027 core.

Smith, M. R.; Laul, J. C.; Simon, S. B.; Papike, J. J.

1985-02-01

132

Petrology and Depositional Setting of Mississippian Rocks Associated with an Anoxic Event at Samak, Western Uinta Mountains, Utah (Chapter S). Petrology and Significance of a Mississippian (Osagean-Meramecian) Anoxic Event, Lakeside Mountains, Northwestern Utah (Chapter T).  

National Technical Information Service (NTIS)

Contents: Petrology and depositional setting of Mississippian rocks associated with an anoxic event at Samak, western Uinta Mountains, Utah; Petrology and significance of a Mississippian (Osagena-Meramecian) anoxic event, Lakeside Mountains, northwestern ...

K. M. Nichols N. J. Silberling

1991-01-01

133

Metastability during metamorphism (reading a metamorphic petrology paper from the literature)  

NSDL National Science Digital Library

I use this problem set as a way to introduce students (mostly sophomores) to reading a technical article from the literature. The paper is Austrheim, H, 1987, Eclogitization of lower crustal granulites by fluid migration through shear zones, Earth and Planetary Science Letters 81:221-232. The paper describes Grenville-age mafic and anorthositic granulites in Norway re-metamorphosed under eclogite facies conditions during the Caledonian. The granulite-facies assemblages persist metastabiliy, and only become eclogite assemblages in or near shear zones where fluids allow the granulite->eclogite reactions to occur. I try to have this problem set serve a number of purposes. First, I ask the students to answer a number of guiding questions so that they work through the paper and look up terms as needed. Some of the questions are directly from the text, and others more are open-ended. I wrap-up the problem set with a 'virtual field trip' of the area discussed in the paper. This slide-show works out much better than similar ones I do in this class, because they have all read about the area and have tried to visualize the field relationships already. The virtual field trip typically leads into interesting discussions about tectonics and metamorphism, polymetamorphism, the meaning of facies, how petrology is done in the field, and how metastability is necessary in order to interpret metamorphic history. In an advanced class other papers by Austrheim and co-workers can be used to explore pseudotachylites and the interplay between metamorphism and seismicity.

Peck, William

134

Application of Automated SEM-EDS Based Mineral Identification Systems to Problems in Metamorphic Petrology  

NASA Astrophysics Data System (ADS)

Automated scanning electron microscopy-energy dispersive x-ray spectrometer (SEM-EDS) based mineral identification systems such as QEMSCAN have been in development for over 20 years, primarily as a tool to understand mineral liberation and element distribution in metal mining industry. This powerful technique is now being used in non mining applications such as metamorphic petrology where accurate mineral identification and metamorphic fabrics are key to deciphering the metamorphic history of samples. The QEMSCAN was developed by CSIRO for application in the mining industry where it is used to understand mineralogy, texture, mineral associations, the presence of gangue minerals and deleterious elements that may potentially interfere with mineral processing and planning, and the overall impact of mineralogy on grinding and flotation processes. It is capable of identifying most rock-forming minerals in milliseconds from their characteristic x-ray spectra. The collected x-ray spectra are compared to entries in a database containing the species identification profiles (SIPs) and are assigned a label accordingly. QEMSCAN is capable of searching large sample areas at high resolution resulting in the accurate and precise determination of all minerals present. Reports that were originally developed for the mining geologist can be equally useful to the petrologist, e.g. phase/mineral maps, modal mineral abundances and mineral association reports. Identification of key minerals is of great importance to determining the petrologic history of a sample. These key minerals may be few in number and present as small microinclusions (less than 100 ?m) making them difficult to identify, if at all, with the petrographic microscope. Therefore, imaging by electron-microprobe or scanning electron microscope are the methods traditionally used. However, because of the small field of view available on these instruments at a magnification necessary to resolve micron sized relicts and textures, the search for a few microinclusions may be extremely time consuming, tedious and costly. QEMSCAN with its ability to provide large quantitative data sets and search large sample areas at high resolution means that whole thin sections can have their mineralogy accurately and precisely determined in hours. For instance in metamorphic petrology once relict minerals of earlier metamorphic assemblages are located; thermobarometry and geochronology can then be applied; resulting in a wealth of information on previous segments of the pressure-temperature-time-deformation path. The relict mineral textures and their relationship to the fabric of the entire thin section can be easily seen in the phase/mineral map yielding important textural information. We have developed a SIP database to be used to study metamorphic samples from the Central Metamorphic terrane (CMt) of the eastern Klamath Mountains, northern California. The CMt was chosen because recent work has resulted in the discovery of relict rutile grains and ilmenite-plagioclase-amphibole symplectites textures interpreted as the decomposition of either garnet or omphacite during exhumation from eclogite facies conditions. The QEMSCAN is being used primarily to search for these relict garnet and omphacite grains. Although only a few samples have been run, no garnet or omphacite have been located thus far. However, in a very short period of time the modal mineral abundances and overall fabric have been determined to a degree never previously achieved.

Fairhurst, Robert; Barrow, Wendy; Rollinson, Gavyn

2010-05-01

135

The Athena Microscopic Imager Investigation  

NASA Technical Reports Server (NTRS)

The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI) [1]. The MI is a fixed-focus camera mounted on the end of an extendable instrument arm, the Instrument Deployment Device (IDD; see Figure 1).The MI was designed to acquire images at a spatial resolution of 30 microns/pixel over a broad spectral range (400 - 700 nm; see Table 1). Technically, the microscopic imager is not a microscope: it has a fixed magnification of 0.4 and is intended to produce images that simulate a geologist s view through a common hand lens. In photographers parlance, the system makes use of a macro lens. The MI uses the same electronics design as the other MER cameras [2, 3] but has optics that yield a field of view of 31 31 mm across a 1024 1024 pixel CCD image (Figure 2). The MI acquires images using only solar or skylightillumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 66 mm), allowing concave surfaces to be imaged in good focus. Because the MI has a relatively small depth of field (3 mm), a single MI image of a rough surface will contain both focused and unfocused areas. Coarse focusing will be achieved by moving the IDD away from a rock target after the contact sensor is activated. Multiple images taken at various distances will be acquired to ensure good focus on all parts of rough surfaces. By combining a set of images acquired in this way, a completely focused image can be assembled. Stereoscopic observations can be obtained by moving the MI laterally relative to its boresight. Estimates of the position and orientation of the MI for each acquired image will be stored in the rover computer and returned to Earth with the image data. The MI optics will be protected from the Martian environment by a retractable dust cover. The dust cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500-700 nm, allowing color information to be obtained by taking images with the dust cover open and closed. The MI will image the same materials measured by other Athena instruments (including surfaces prepared by the Rock Abrasion Tool), as well as rock and soil targets of opportunity. Subsets of the full image array can be selected and/or pixels can be binned to reduce data volume. Image compression will be used to maximize the information contained in the data returned to Earth. The resulting MI data will place other MER instrument data in context and aid in petrologic and geologic interpretations of rocks and soils on Mars.

Herkenhoff, K. E.; Aquyres, S. W.; Bell, J. F., III; Maki, J. N.; Arneson, H. M.; Brown, D. I.; Collins, S. A.; Dingizian, A.; Elliot, S. T.; Geotz, W.

2003-01-01

136

Virtual courseware for geoscience education: Virtual Earthquake and Virtual Dating  

NASA Astrophysics Data System (ADS)

Virtual courseware developed for introductory-level, on-line geology labs is an interactive teaching/learning model that has an enormous pedagogical potential for making Web sites places where students learn by doing. Virtual Earthquake and Virtual Dating are modest examples of the `virtual courseware' paradigm. Virtual Earthquake helps students explore the techniques of how an earthquake's epicenter is located and how its Richter magnitude is determined. Virtual Dating models the theory and techniques of the radiometric age determination of rocks and minerals. Virtual courseware applications offer several advantages over traditional floppy disk or CD ROM-based courseware, the most significant being the ease of dissemination. The author's experience with bringing these two virtual applications on-line suggests that there is a need for interactive geology labs on-line and that the approach will be received with enthusiasm by the educational community. The widespread implementation and adoption of virtual courseware can bring meaningful educational content and interactivity for the geosciences that goes beyond multimedia on the World-Wide-Web.

Novak, Gary A.

1999-05-01

137

The multifocus imaging technique in petrology  

NASA Astrophysics Data System (ADS)

The present paper provides a review of an imaging tool that is relatively underused in petrographic studies: the multifocus technique. Commonly used in macrophotography, and particularly in the imaging of minerals, it can also be applied to the imaging of thin sections where inclusions or other features that are present at different depths in the section can be combined into the same image. Improvements in computer performance and in image combination software make the technique simple and efficient. Its latest developments allow three-dimensional reconstructions of inclusions and other features of petrographic interest to be visualized. The difficulties of imaging under the optical microscope at high magnification are reviewed and demonstrations of the advantages of the multifocus technique are provided. Compared to more specialized and expensive imaging methods, such as confocal scanning microscopy and X-ray computed tomography, the multifocus technique offers an inexpensive and rapid approach, which is useful as an initial check as to whether more elaborate techniques are justified.

Thiéry, V.; Green, D. I.

2012-08-01

138

Virtual Worlds, Real Learning  

ERIC Educational Resources Information Center

Many children between the ages of four and twelve log in to Web-based virtual play spaces each day, and these virtual worlds are quickly becoming an important aspect of their out-of-school lives. Consequently, educators' challenge is to see how they can leverage virtual spaces, such as the virtual play spaces, for learning and literacy. Over the…

Meyers, Eric M.

2009-01-01

139

Virtual button interface  

DOEpatents

An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment are disclosed. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch. 4 figs.

Jones, J.S.

1999-01-12

140

Cryogenic immersion microscope  

DOEpatents

A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

Le Gros, Mark (Berkeley, CA); Larabell, Carolyn A. (Berkeley, CA)

2010-12-14

141

Low polarization microscope objectives  

NASA Astrophysics Data System (ADS)

Low polarization, high numerical aperture microscope objectives ideal for polarization sensitive applications are designed, fabricated, and measured. A microscope objective is designed to meet the application requirements using Code V. Performance of typical AR coatings is examined and determined to be insufficient to meet the polarization performance desired. Custom AR coatings are optimized using an in house polarization ray tracing program to reduce the objectives diattenuation. The resulting microscope objectives perform about 5 times better than our low polarization Nikon objectives.

Daugherty, Brian; Chipman, Russell

2010-07-01

142

Thermal-Wave Microscope  

NASA Technical Reports Server (NTRS)

Computer-controlled thermal-wave microscope developed to investigate III-V compound semiconductor devices and materials. Is nondestructive technique providing information on subsurface thermal features of solid samples. Furthermore, because this is subsurface technique, three-dimensional imaging also possible. Microscope uses intensity-modulated electron beam of modified scanning electron microscope to generate thermal waves in sample. Acoustic waves generated by thermal waves received by transducer and processed in computer to form images displayed on video display of microscope or recorded on magnetic disk.

Jones, Robert E.; Kramarchuk, Ihor; Williams, Wallace D.; Pouch, John J.; Gilbert, Percy

1989-01-01

143

Recurrence tracking microscope  

SciTech Connect

In order to probe nanostructures on a surface we present a microscope based on the quantum recurrence phenomena. A cloud of atoms bounces off an atomic mirror connected to a cantilever and exhibits quantum recurrences. The times at which the recurrences occur depend on the initial height of the bouncing atoms above the atomic mirror, and vary following the structures on the surface under investigation. The microscope has inherent advantages over existing techniques of scanning tunneling microscope and atomic force microscope. Presently available experimental technology makes it possible to develop the device in the laboratory.

Saif, Farhan [Department of Electronics, Quaid-i-Azam University, Islamabad 45320, Pakistan and Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2006-03-15

144

Fluorescence spectroscopy: A promising tool for carbonate petrology  

SciTech Connect

Responses of depositional and diagenetic components in samples of the Mission Canyon Limestone to blue-light excitation vary most noticeably with mineralogy and crystal size. The finely crystalline micrites, dolomicrites and argillaceous carbonates fluoresce more intensely than the more coarsely crystalline sparry calcite cements, dolospar cements and coarsely crystalline dolomites. Low intensity spectral analysis of cherts, anhydrites, and the carbonate phases provides an objective manner for quantifying fluorescence responses and for comparing them statistically. Nineteen of the optical parameters used in organic petrology are evaluated for their utility in carbonate petrology. Results of the discriminant function analysis suggest that red-weighted fluorescence chromaticity indices and yellow-weighted ones are more useful for mineral identification than the blue-weighted or equal-energy chromaticity indices. Statistical analysis of the optical data, mineralogy, and minor element compositions suggests correlations between the fluorescence responses and major minerals, carbonate diagenetic components, and the minor element geochemistry of carbonate components. Although no single element is identified as an activator of fluorescence in this study, the complex correlations of optical indices with Fe suggest that it does act to quench fluorescence. The four fluorescence cy chromaticity indices correlate significantly and positively with mineralogy and negatively with MgCo[sub 3]. In organic petrology, these indices are related to maceral content. The positive correlations of the four fluorescence cx chromaticity indices with Fe and Mn likely reflect fluorescence response to changes in compositions of pore fluids during diagenesis. This trend parallels the increase in cx indices with increasing maturation of organic materials.

Vice, M.A.; Bensley, D.F.; Utgaard, J.E. (Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology)

1992-01-01

145

Photography through the Microscope.  

ERIC Educational Resources Information Center

Describes how to illuminate and optically stain slides for microscope use and how to interface a 35mm camera with a microscope using an adaptor. Provides equipment descriptions and sources, details about illumination, image formation, darkfield adaptors, centerable filter adaptors, darkfield stops, rheinburg filters, and choosing specimens to…

McNeil, D. W.

1992-01-01

146

Surface imaging microscope  

NASA Astrophysics Data System (ADS)

The three-dimensional shapes of microscopic objects are becoming increasingly important for battlespace CBRNE sensing. Potential applications of microscopic 3D shape observations include characterization of biological weapon particles and manufacturing of micromechanical components. Aerosol signatures of stand-off lidar systems, using elastic backscatter or polarization, are dictated by the aerosol particle shapes and sizes that must be well characterized in the lab. A low-cost, fast instrument for 3D surface shape microscopy will be a valuable point sensor for biological particle sensing applications. Both the cost and imaging durations of traditional techniques such as confocal microscopes, atomic force microscopes, and electron scanning microscopes are too high. We investigated the feasibility of a low-cost, fast interferometric technique for imaging the 3D surface shape of microscopic objects at frame rates limited only by the camera in the system. The system operates at two laser wavelengths producing two fringe images collected simultaneously by a digital camera, and a specialized algorithm we developed reconstructs the surface map of the microscopic object. The current implementation assembled to test the concept and develop the new 3D reconstruction algorithm has 0.25 micron resolution in the x and y directions, and about 0.1 micron accuracy in the z direction, as tested on a microscopic glass test object manufactured with etching techniques. We describe the interferometric instrument, present the reconstruction algorithm, and discuss further development.

Rogala, Eric W.; Bankman, Isaac N.

2008-05-01

147

The Light Microscope.  

ERIC Educational Resources Information Center

Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

Baker, W. L.

1995-01-01

148

T-Ray Microscope.  

National Technical Information Service (NTIS)

A microscope for producing an image of a target using THz radiation. The microscope comprises a source for providing an optical pump pulse and an optical probe pulse; a THz emitter for activation by pump pulse to emit a THz pulse that irradiates the targe...

J. Xu T. Yuan X. C. Zhang

2003-01-01

149

Scanning Probe Microscope.  

National Technical Information Service (NTIS)

This DURIP allowed us to purchase a Digital Instruments Dimension 3100 Atomic Force Microscope (AFM), which is a versatile tool that can serve dual functions, both as an AFM and a scanning-tunneling microscope (STM) . The AFM and the STM are separated uni...

M. R. Melloch

2001-01-01

150

The Homemade Microscope.  

ERIC Educational Resources Information Center

Directions for the building of a pocket microscope that will make visible the details of insect structure and living bacteria are described. Background information on the history of microscopes and lenses is provided. The procedures for producing various types of lenses are included. (KR)

Baker, Roger C., Jr.

1991-01-01

151

Petrology of lunar rocks and implication to lunar evolution  

NASA Technical Reports Server (NTRS)

Recent advances in lunar petrology, based on studies of lunar rock samples available through the Apollo program, are reviewed. Samples of bedrock from both maria and terra have been collected where micrometeorite impact penetrated the regolith and brought bedrock to the surface, but no in situ cores have been taken. Lunar petrogenesis and lunar thermal history supported by studies of the rock sample are discussed and a tentative evolutionary scenario is constructed. Mare basalts, terra assemblages of breccias, soils, rocks, and regolith are subjected to elemental analysis, mineralogical analysis, trace content analysis, with studies of texture, ages and isotopic composition. Probable sources of mare basalts are indicated.

Ridley, W. I.

1976-01-01

152

University of Minnesota Structure Tectonics and Metamorphic Petrology Research Group  

NSDL National Science Digital Library

The University of Minnesota Structure Tectonics and Metamorphic Petrology Research Group describes its research on the deformation of continental lithosphere at this website. Users can find clear explanations of the group's current projects including partial melting and orogeny, continental subduction, and shear zones. Students and scientists can find the research interests and a list of publications for the group's faculty, research associates, and students. The website displays the group's analytical, field, and teaching equipment as well as its Institute for Rock Magnetism and Characterization Facility.

153

Mineralogy and petrology of fragments from the Luna 24 core  

NASA Astrophysics Data System (ADS)

Luna 24, the Soviet lunar mission of August 1976, recovered a 170 g core of regolith material from Mare Crisium, on the eastern limb of the moon. This paper describes the petrology and mineralogy of five rock fragments and the 75-106 micron fine fractions from three levels in this core. Nearly all the minerals analyzed are derived from the basaltic rocks native to Mare Crisium, very few are transported highland material. The proportion of highland material occurring as glass fragments in the fine fractions is larger than that which is present as mineral fragments.

Graham, A. L.; Hutchison, R.

1980-06-01

154

Development of MRI Microscope  

NASA Astrophysics Data System (ADS)

We have been developing an ultra high spatial resolution MRI, “MRI Microscope”, especially for 3He physics at ultra low temperature. The ultimate goal of our MRI Microscope is to achieve 1 ?m×1 ?m two dimensional spatial resolution comparable to optical microscopes. We constructed the MRI Microscope using a magnetic field of 7.2 T, with tri-axial magnetic field gradients of 2.0 T/m. We visualized the pure liquid 3He in a 230 ?m diameter tube to study the effect of nonlinearity on the MRI Microscope at low temperature and in high magnetic fields. An MRI image was obtained at 0.22 MPa, 1 K with 1.8 ?m×1.8 ?m pixel size. At 65 mK, the MRI image became more blurred. We speculate that it was caused by large spin diffusion and nonlinearity.

Hachiya, Mahiro; Arimura, Kyohei; Ueno, Tomohiro; Matsubara, Akira

2010-02-01

155

Igneous and metamorphic petrology in the field: a problem-based, writing-intensive alternative to traditional classroom petrology  

NASA Astrophysics Data System (ADS)

The Geology Department at Western Washington University (~100 geology majors) offers field and classroom versions of its undergraduate petrology course. This is a one-quarter course (igneous and metamorphic petrology) with mineralogy as a prerequisite. The field version of the course is offered during the three weeks prior to fall quarter and the classroom version is offered in spring quarter. We take 15-20 students around the state of Washington, camping at different outcrop sites where students integrate observational skills, petrologic knowledge, and writing. Petrogenetic associations in various tectonic settings provide the theme of the course. We compare ophiolites vs. arc sequences (volcanic, plutonic, and metamorphic rocks), S- vs. I-type granitoids (plutonic rocks and associated metamorphic rocks), Barrovian vs. Buchan vs. subduction zone metamorphism of different protoliths, and flood-basalt vs. active-arc volcanism. Some basics are covered in the first day at WWU, followed by 17 days of field instruction. Lecture is integrated with outcrop study in the field. For example, students will listen to a lecture about magma differentiation processes as they examine cumulate rocks in the Mt. Stuart batholith, and a lecture about metamorphic facies as they study blueschist facies rocks in the San Juan Islands. Students study multiple outcrops around a site for 1-4 days. They then use their observations (sketches and written descriptions of mineral assemblages, rock types, rock textures, etc.) and analysis techniques (e.g. geochemical data plotting, metamorphic protolith analysis) to write papers in which the data are interpreted in terms of a larger tectonic problem. In advance of the writing process, students use group discussion techniques such as whiteboarding to share their observational evidence and explore interpretations. Student evaluations indicate that despite the intense pace of the course, they enjoy it more. Students also feel that they retain more material for future classes. The undivided attention, immediate writing/reflection, and repetition of skills in different settings reinforce material. Because of students' higher level of engagement, more of them pursue advanced classes or independent studies. A corollary benefit is that students form strong bonds with their cohort group, providing mutual support as they continue through the program and ultimately improving their field camp experience. Final exam scores are equal to or better than in the traditional class, and some basic skills, such the ability to make observations at a variety of scales in sketches and writing, are better. Students can also better distinguish between observation and inference in report writing. Finally, students can apply their theoretical understanding of petrologic processes (e.g. magma differentiation, metamorphic facies progressions) to real rocks in a more sophisticated way using evidence.

DeBari, S. M.

2011-12-01

156

Geochemistry of Martian Meteorites and the Petrologic Evolution of Mars  

NASA Technical Reports Server (NTRS)

Mafic igneous rocks serve as probes of the interiors of their parent bodies - the compositions of the magmas contain an imprint of the source region composition and mineralogy, the melting and crystallization processes, and mixing and assimilation. Although complicated by their multifarious history, it is possible to constrain the petrologic evolution of an igneous province through compositional study of the rocks. Incompatible trace elements provide one means of doing this. I will use incompatible element ratios of martian meteorites to constrain the early petrologic evolution of Mars. Incompatible elements are strongly partitioned into the melt phase during igneous processes. The degree of incompatibility will differ depending on the mineral phases in equilibrium with the melt. Most martian meteorites contain some cumulus grains, but nevertheless, incompatible element ratios of bulk meteorites will be close to those of their parent magmas. ALH 84001 is an exception, and it will not be discussed. The martian meteorites will be considered in two groups; a 1.3 Ga group composed of the clinopyroxenites and dunite, and a younger group composed of all others.

Mittlefehldt, D. W.

2002-01-01

157

Petrology, chemistry, and origin of Apollo 15 regolith breccias  

NASA Technical Reports Server (NTRS)

Variations in modal petrology, mineral compositions, and bulk compositions were determined for ten Apollo 15 regolith breccias for comparison with local soils and assessment of the intrasite petrologic variability of the Apollo 15 regolith. Based on the above criteria the breccias are of local origin and mimic the soils from the corresponding sampling stations, with the exception of station 2 breccia 15205. This sample formed from an anomalous regolith, and although not considered exotic to the site is not representative of the soil at the site. KREEP basalt and green glass components vary from trace amounts to dominant in the breccias, evidence that these materials entered the regolith prior to formation of the breccias. Breccias from the edge of Hadley Rille are modally richer in highland fragments than the soils, whereas at the base of Hadley Delta the reverse is true. This is explained by the loss of material into the Rille to be replaced by basalt-derived material, making the soils more basalt-rich. At the base of Hadley Delta highland material is accumulating and the soils are becoming more highland-rich. Over billions of years these processes have developed differences between the present day, evolving soils, and 'fossil' nonevolving soils represented by the regolith breccias. This shows that there has been little change in the geology and the morphology of the Apollo 15 site, probably since the eruption of mare basalts at the site (about 3.3 b.y.).

Simon, S. B.; Papike, J. J.; Gosselin, D. C.; Laul, J. C.

1986-01-01

158

A portable laser photostimulation and imaging microscope  

NASA Astrophysics Data System (ADS)

We describe a compact microscope that uses a spatial light modulator (SLM) to control the excitation laser light. The flexibility of SLMs, which can mimic virtually any optical transfer function, enables the experimenter to create, in software, arbitrary spatio-temporal light patterns, including focusing and beam scanning, simply by calculating the appropriate phase mask. Our prototype, a scan-less device with no moving parts, can be used for laser imaging or photostimulation, supplanting the need for an elaborate optical setup. As a proof of principle, we generate complex excitation patterns on fluorescent samples and also perform functional imaging of neuronal activity in living brain slices.

Nikolenko, Volodymyr; Peterka, Darcy S.; Yuste, Rafael

2010-08-01

159

A portable laser photostimulation and imaging microscope  

PubMed Central

We describe a compact microscope that uses a Spatial Light Modulator (SLM) to control the excitation laser light. The flexibility of SLMs, which can mimic virtually any optical transfer function, enables the experimenter to create, in software, arbitrary spatio-temporal light patterns, including focusing and beam scanning, simply by calculating the appropriate phase mask. Our prototype, a scan-less device with no moving parts, can be used for laser imaging or photostimulation, supplanting the need for an elaborate optical setup. As a proof of principle, we generate complex excitation patterns on fluorescent samples and also perform functional imaging of neuronal activity in living brain slices.

Nikolenko, Volodymyr; Peterka, Darcy S.; Yuste, Rafael

2013-01-01

160

Designing the virtual campus  

Microsoft Academic Search

Designing a virtual campus raises pedagogical questions as well as questions about the difference between the design of physical places and virtual places. When creating a virtual learning environment, we do not just ask, how do we present lecture notes and assignments on the internet? We also ask, how do we develop a learning environment in which students can access

Mary Lou Maher; Bradford Skow; Anna Cicognani

1999-01-01

161

Stereo Microscopes: Technical Evaluation.  

National Technical Information Service (NTIS)

The purpose of this study was to accomplish technical evaluations of various stereo microscopes which may be used in a dental laboratory. This report will provide assistance to base dental surgeons for selection of units for their particular requirements....

A. H. King

1990-01-01

162

Petrology and Geochemistry of D'Orbigny, Geochemistry of Sahara 99555, and the Origin of Angrites  

NASA Technical Reports Server (NTRS)

We have done detailed petrologic study of the angrite, D'Orbigny, and geochemical study of it and Sahara 99555. D'Orbigny is an igneous-textured rock composed of Ca-rich olivine, Al-Ti-diopside-hedenbergite, subcalcic kirschsteinite, two generations of hercynitic spinel and anorthite, with the mesostasis phases ulv6spinel, Ca-phosphate, a silicophosphate phase and Fe-sulfide. We report an unknown Fe-Ca-Al-Ti-silicate phase in the mesostasis not previously found in angrites. One hercynitic spinel is a large, rounded homogeneous grain of a different composition than the euhedral and zoned grains. We believe the former is a xenocryst, the first such described from angrites. The mafic phases are highly zoned; mg# of cores for olivine are approx.64, and for clinopyroxene approx.58, and both are zoned to Mg-free rims. The Ca content of olivine increases with decreasing mg#, until olivine with approx.20 mole% Ca is overgrown by subcalcic kirschsteinite with Ca approx.30-35 mole%. Detailed zoning sequences in olivine-subcalcic kirschsteinite and clinopyroxene show slight compositional reversals. There is no mineralogic control that can explain these reversals, and we believe they were likely caused by local additions of more primitive melt during crystallization of D'Orbigny. D'Orbigny is the most ferroan angrite with a bulk rock mg# of 32. Compositionally, it is virtually identical to Sahara 99555; the first set of compositionally identical angrites. Comparison with the other angrites shows that there is no simple petrogenetic sequence, partial melting with or without fractional crystallization, that can explain the angrite suite. Angra dos Reis remains a very anomalous angrite. Angrites show no evidence for the brecciation, shock, or impact or thermal metamorphism that affected the HED suite and ordinary chondrites. This suggests the angrite parent body may have followed a fundamentally different evolutionary path than did these other parent bodies.

Mittlefehldt, David W.; Killgore, Marvin; Lee, Michael T.

2001-01-01

163

Infrared microscope inspection apparatus  

DOEpatents

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

Forman, Steven E. (Framingham, MA); Caunt, James W. (Concord, MA)

1985-02-26

164

A Simple Reflecting Microscope  

Microsoft Academic Search

INTEREST in reflecting microscopes has been considerably stimulated in recent years as a result of the development by Burch1 of instruments of this type with aspheric surfaces. The advantage of the reflecting microscope lies in its complete achromatism, which enables it to be used with ultra-violet, visible or infra-red light, and in its large working distance, which is sufficient for

W. E. Seeds; M. H. F. Wilkins

1949-01-01

165

Microscopic Theory of Fission  

SciTech Connect

In recent years, the microscopic method has been applied to the notoriously difficult problem of nuclear fission with unprecedented success. In this paper, we discuss some of the achievements and promise of the microscopic method, as embodied in the Hartree-Fock method using the Gogny finite-range effective interaction, and beyond-mean-field extensions to the theory. The nascent program to describe induced fission observables using this approach at the Lawrence Livermore National Laboratory is presented.

Younes, W.; Gogny, D. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

2008-04-17

166

Minerals Under the Microscope  

NSDL National Science Digital Library

This website provides an easy-to-understand introduction to the basics of optical mineralogy. Topics include the polarized light microscope, mineral shape and cleavage, relief, color and pleochroism, interference colors, extinction angles, twinning, opacity, vibration directions and mineral identification. The site features short, clear descriptions accompanied by photographs and drawings. This website would be useful as a concise introduction to the use of a petrographic microscope in identifying minerals.

Browning, Paul; Gladstone, Charlotte

2011-03-02

167

Infrared microscope inspection apparatus  

DOEpatents

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

Forman, S.E.; Caunt, J.W.

1985-02-26

168

Teaching Igneous and Metamorphic Petrology Through Guided Inquiry Projects  

NASA Astrophysics Data System (ADS)

Undergraduate Petrology at New Mexico State University (GEOL 399) has been taught using three, 5-6 week long projects in place of lectures, lab, and exams for the last six years. Reasons for changing from the traditional format include: 1) to move the focus from identification and memorization to petrologic thinking; 2) the need for undergraduate students to apply basic chemical, structural, and field concepts to igneous and metamorphic rocks; 3) student boredom in the traditional mode by the topic that has captivated my professional life, in spite of my best efforts to offer thrilling lectures, problems, and labs. The course has three guided inquiry projects: volcanic, plutonic, and pelitic dynamothermal. Two of the rock suites are investigated during field trips. Each project provides hand samples and thin sections; the igneous projects also include whole-rock major and trace element data. Students write a scientific paper that classifies and describes the rocks, describes the data (mineralogical and geochemical), and uses data to interpret parameters such as tectonic setting, igneous processes, relationship to phase diagrams, geologic history, metamorphic grade, metamorphic facies, and polymetamorphic history. Students use the text as a major resource for self-learning; mini-lectures on pertinent topics are presented when needed by the majority of students. Project scores include evaluation of small parts of the paper due each Friday and participation in peer review as well as the final report. I have found that petrology is much more fun, although more difficult, to teach using this method. It is challenging to be totally prepared for class because students are working at different speeds on different levels on different aspects of the project. Students enjoy the course, especially the opportunity to engage in scientific investigation and debate. A significant flaw in this course is that students see fewer rocks and have less experience in rock classification. This is partially remedied by four field trips and two supplemental assignments (igneous and metamorphic) in which students identify hand samples of a wide variety of rock types. The project-based approach enhances critical thinking, math, reading, and writing skills at the expense of hand sample identification and the benefits of review of material prior to testing.

McMillan, N. J.

2003-12-01

169

A Magnetic Petrology Database for Satellite Magnetic Anomaly Interpretations  

NASA Astrophysics Data System (ADS)

A Magnetic Petrology Database (MPDB) is now being compiled at NASA/Goddard Space Flight Center in cooperation with Russian and Ukrainian Institutions. The purpose of this database is to provide the geomagnetic community with a comprehensive and user-friendly method of accessing magnetic petrology data via Internet for more realistic interpretation of satellite magnetic anomalies. Magnetic Petrology Data had been accumulated in NASA/Goddard Space Flight Center, United Institute of Physics of the Earth (Russia) and Institute of Geophysics (Ukraine) over several decades and now consists of many thousands of records of data in our archives. The MPDB was, and continues to be in big demand especially since recent launching in near Earth orbit of the mini-constellation of three satellites - Oersted (in 1999), Champ (in 2000), and SAC-C (in 2000) which will provide lithospheric magnetic maps with better spatial and amplitude resolution (about 1 nT). The MPDB is focused on lower crustal and upper mantle rocks and will include data on mantle xenoliths, serpentinized ultramafic rocks, granulites, iron quartzites and rocks from Archean-Proterozoic metamorphic sequences from all around the world. A substantial amount of data is coming from the area of unique Kursk Magnetic Anomaly and Kola Deep Borehole (which recovered 12 km of continental crust). A prototype MPDB can be found on the Geodynamics Branch web server of Goddard Space Flight Center at http://core2.gsfc.nasa.gov/terr_mag/magnpetr.html. The MPDB employs a searchable relational design and consists of 7 interrelated tables. The schema of database is shown at http://core2.gsfc.nasa.gov/terr_mag/doc.html. MySQL database server was utilized to implement MPDB. The SQL (Structured Query Language) is used to query the database. To present the results of queries on WEB and for WEB programming we utilized PHP scripting language and CGI scripts. The prototype MPDB is designed to search database by major satellite magnetic anomaly, tectonic structure, geographical location, rock type, magnetic properties, chemistry and reference, see http://core2.gsfc.nasa.gov/terr_mag/query1.html. The output of database is HTML structured table, text file, and downloadable file. This database will be very useful for studies of lithospheric satellite magnetic anomalies on the Earth and other terrestrial planets.

Nazarova, K.; Wasilewski, P.; Didenko, A.; Genshaft, Y.; Pashkevich, I.

2002-05-01

170

Virtual microscopy, data management and image analysis in Aperio ScanScope system.  

PubMed

The histology and the pathology clinical practice undergo a digital revolution. Essential change in laboratory practice - from classical light microscopes, thousands of glass specimens waiting on plates to a virtual microscope and onscreen diagnosis is right now. Currently there are more than 30 different systems for the Virtual Microscopy available on the market. However none of them is so oriented for the practical matters as Aperio ScanScope system. PMID:20430741

Staniszewski, Wojciech

2009-01-01

171

Virtual annotation: Verbal communication in virtual reality  

NASA Astrophysics Data System (ADS)

A system that was developed to explore communication in virtual reality and which offers a simple and powerful method to embed verbal communication in simulations and visualizers by means of voice annotation is described. The prototype demonstrates that the addition of verbal communication opens up a range of new uses for virtual environments. A similar voice annotation facility is easily added to existing visualizers and simulations, and it enables reading, writing and communicating.

Verlinden, Jouke C.; Bolter, Jay David; Vandermast, Charles

172

Petrology, Mineralogy and Mineral Chemistry of Antarctic Monomict Eucrites CMS 04049 and QUE 97053  

NASA Astrophysics Data System (ADS)

We report petrology and mineral chemistry data including trace element abundances in minerals of two monomict eucrites, CMS 04049 and QUE 97053 to understand igneous and post-crystallization history of eucrite.

Righter, M.; Lapen, T. J.

2010-03-01

173

Petrology and Petrography of the Campeche Lithic Suite, Yucatan Shelf, Mexico.  

National Technical Information Service (NTIS)

The purpose of this study is to describe the carbonate petrology and petrography of limestone fragments collected in submarine samples taken from the Campeche Bank, Yucatan Shelf, Mexico. The specific points considered are (1) the interpretation of the mo...

J. L. Harding

1964-01-01

174

Petrology of Chondrules and a Diopside-Rich Inclusion in the MAC 88136 EL3 Chondrite  

NASA Astrophysics Data System (ADS)

MAC 88136 (EL3) contains densely-packed enstatite-rich chondrules, metal-rich nodules intergrown with silicate and an unusual large, diopside-rich chondrule-like object. Petrologic and chemical features suggest hot accretion for its components.

Weisberg, M. K.; Ebel, D. S.; Kimura, M.

2012-09-01

175

Learning Activities for an Undergraduate Mineralogy/Petrology Course-"I Am/We Are."  

ERIC Educational Resources Information Center

Introduces an entry level mineralogy/igneous petrology course designed for undergraduate students and presents a series of learning activities based on individual and cooperative learning. Includes 18 references. (Author/YDS)

Goodell, Philip C.

2001-01-01

176

Linking petrology and seismology at an active volcano.  

PubMed

Many active volcanoes exhibit changes in seismicity, ground deformation, and gas emissions, which in some instances arise from magma movement in the crust before eruption. An enduring challenge in volcano monitoring is interpreting signs of unrest in terms of the causal subterranean magmatic processes. We examined over 300 zoned orthopyroxene crystals from the 1980-1986 eruption of Mount St. Helens that record pulsatory intrusions of new magma and volatiles into an existing larger reservoir before the eruption occurred. Diffusion chronometry applied to orthopyroxene crystal rims shows that episodes of magma intrusion correlate temporally with recorded seismicity, providing evidence that some seismic events are related to magma intrusion. These time scales are commensurate with monitoring signals at restless volcanoes, thus improving our ability to forecast volcanic eruptions by using petrology. PMID:22628652

Saunders, Kate; Blundy, Jon; Dohmen, Ralf; Cashman, Kathy

2012-05-25

177

Apollo 15 yellow impact glasses: Chemistry, petrology, and exotic origin  

SciTech Connect

The Apollo 15 yellow impact glasses are characterized by moderate TiO/sub 2/ (approx.4.8%) and high abundances of the large ion lithophile elements (e.g., K, P, Hf, Th, REE). Since the chemistry of these glasses cannot be duplicated by any combination of local components presently known to occur at the Apollo 15 landing site, these yellow glasses seem to be exotic to that area. Chemical and petrologic constraints suggest that these samples were produced by impact melting of an immature mare regolith developed upon an unusual variety of mare basalt. We speculate that the target basalt were the youngest lava flows known to exist on the moon (i.e., Eratosphenian-age lavas in Oceanus Procellarum and Mare Imbrium). Specific tests are proposed for evaluating this provocative hypothesis.

Delano, J.W.; Lindsley, D.H.; Ma, M.; Schmitt, R.A.

1982-11-15

178

Petrology, chemistry, age and irradiation history of Luna 24 samples  

NASA Technical Reports Server (NTRS)

The results of petrological, chemical, isotopic age determination and irradiation studies of sample 24170 from the 170 cm depth of the regolith core returned from Mare Crisium by Luna 24 are presented. The sample is found to be comprised of fragments from a single igneous rock, with mineralogical evidence indicating it to be a mare basalt. The crystallization age is determined by Sm-Nd and Ar(40)-Ar(39) ages to be 3.30 AE, establishing the presence of relatively young flows. All soil samples show low trace element compositions with minimum contamination by KREEPUTh-rich materials. Rb-Sr and Sm-Nd relations reflect the absence of significant fractionation at ages younger than 4.5 AE. One soil sample shows extremely large neutron capture effects, imposing a new lower limit to the neutron production rate in the regolith and requiring the addition of irradiated materials from depth.

Wasserburg, G. J.; Papanastassiou, D. A.; Mcculloch, M. T.; Huneke, J. C.; Dymek, R. F.; Depaolo, D. J.; Chodos, A. A.; Albee, A. L.; Radicati Di Brozolo, F.

1978-01-01

179

Petrology and geochemistry of alkali gabbronorites from lunar breccia 67975  

NASA Technical Reports Server (NTRS)

Detailed results of petrologic and compositional studies of three clasts found in thin sections of the Apollo 16 lunar breccia 67975 and of four clasts extracted from the breccia (for instrumental neutron activation analysis) prior to thin sectioning are reported. The alkali gabbronorites of the breccia form two distinct subgroups, magnesian and ferroan. The magnesian gabbronorites are composed of bytownitic plagioclase, hypersthene, augite, a silica mineral, and trace Ba-rich K-feldspar. The ferroan gabbronorites are composed of ternary plagioclase, pigeonite, augite, Ba-rich K-feldspar, and a silica mineral. Trace minerals in both subgroups are apatite, REE-rich whitlockite, and zircon. The magnesian and ferroan alkali gabbronorites appear to have formed by progressive differentiation of the same, or closely related, parent REE-rich magmas.

James, Odette B.; Flohr, Marta K.; Lindstrom, Marilyn M.

1987-01-01

180

Petrology and geochemistry of lunar dimict breccia 61015  

NASA Technical Reports Server (NTRS)

The results of a petrological and geochemical study of the dimict breccia 61015 at the Apollo 16 site are presented and discussed. The breccia consists predominantly of granulated anorthosite and impact melt rock of very high aluminum-basalt composition. It probably formed in the floor of an expanding crater cavity when impact melt generated within the cavity was injected into underlying anorthositic bedrock and solidified rapidly, the anorthosite and melt rock being fragmented by deformation in the later stages of the impact. A possible source crater for the breccia is identified. The breccia has been affected by at least one recent small impact, which produced internal shock-induced melting of the breccia and injected and coated the rock with externally derived melts. The TiO2 content of the coating and vein glasses establish that they cannot be melted soils; their composition requires a mafic, low-TiO2 protolith component.

James, O. B.; Flohr, M. K.; Lindstrom, M. M.

1984-01-01

181

Mineralogy and Petrology of Unbrecciated Lunar Basaltic Meteorite LAP 02205  

NASA Technical Reports Server (NTRS)

LAP 02205 is a 1.2 kg unbrecciated basalt found in the LaPaz icefield of Antarctica during the 2002-2003 ANSMET season [1]. It has been classified as a lunar basalt on the basis of pyroxene Fe/Mn ratios (approx. 60) and oxygen isotopes [1]; both are within previously defined compositional ranges for the Moon [2]. We have initiated a comprehensive study of the mineralogy, petrology and geochemistry of this new and unique meteorite. The results reported here will allow the comparison of this sample both to the other lunar basaltic meteorites (NWA 032, A881757, Y793169, Dho287A), as well as to lunar basalts in the Apollo and Luna collections.

Righter, K.; Brandon, A. D.; Norman, M. D.

2004-01-01

182

An Isotopic and Petrologic Study of Calcium-Aluminum-Rich Inclusions from CO3 Meteorites  

Microsoft Academic Search

We have studied the mineralogy and petrology of 229 calcium-aluminum-rich inclusions (CAIs) from ten CO3 meteorites of petrologic types 3.0–3.7. Subsets of these inclusions were measured by ion probe for magnesium, calcium, and titanium isotopes and REE abundances. Most CAIs from CO3 meteorites fall into three major types: (1) melilite-rich inclusions, which also contain spinel\\/hercynite, perovskite, and occasionally hibonite; (2)

S. S. Russell; G. R. Huss; A. J. Fahey; R. C. Greenwood; R. Hutchison; G. J. Wasserburg

1998-01-01

183

Towards the Petrophysics and Petrology of Earth's Deep Mantle and the Core Mantle Boundary  

Microsoft Academic Search

Petrophysics measures the physical properties of rocks. Petrology investigates the physical and chemical conditions of their formation as well as attempts to unscramble the p-T-path of a multi-phase development. Petrology is focussed on investigating the shifting equilibrium conditions between the different minerals constituting the crystalline rocks. Because the knowledge is mostly derived from powder high pressure experiments the perspective is

H. J. Mueller

2010-01-01

184

An Inquiry-Based Approach to Learning Petrology Using Student-Generated Data  

NSDL National Science Digital Library

The Petrology course at Macalester College is designed around a semester-long project. All laboratory and classroom activities within the course are directed toward understanding and solving a real-world problem, the origin and evolution of an intrusion in northern Minnesota. Emphasis is on using multi-disciplinary approaches, modern instrumentation, and student-generated data. After completing the course, students exhibit improved quantitative skills, reasoning, and understanding of fundamental petrologic processes.

Wirth, Karl R.

185

Petrologic and In Situ Geochemical Constraints on Diogenite Genesis  

NASA Technical Reports Server (NTRS)

Diogenites, members of the howardite, eucrite and diogenite (HED) clan, are orthopyroxenite, harzburgite and dunite meteorites [1-3]. Most are breccias, but remnant textures indicate they were originally coarse-grained rocks, with grain sizes of order of cm. Their petrography and compositions support an origin as crustal cumulates from a differentiated asteroid. Astronomical observations, and surface mineralogy and composition of Vesta determined by the Dawn spacecraft suggest that asteroid (4) Vesta is the parent object for HED meteorites [4-6]. The origin of diogenites is an unsettled issue. It is difficult to fit their bulk compositional characteristics into global magma ocean models that successfully describe the compositions of basaltic and cumulate eucrites [7]. Compositional analyses of acid-leached bulk samples have led to the hypothesis that many diogenites were formed late by interaction of their parent melts with a eucritic crust [8]. Those observations may alternatively be explained by subsolidus equilibration of trace elements between orthopyroxene and minor/ accessory phases in the rocks such as plagioclase and phosphate [7]. These competing hypotheses can be tested through in situ measurements of trace and minor elements in orthopyroxene. Our new petrologic observations and in situ minor and trace element data for a suite of diogenites are used to discuss the petrologic evolution of diogenites. Our preliminary data on two diogenites are consistent with the hypothesis that subsolidus element mobilization processes caused unusual trace element signatures seen in some diogenites [7]. We cannot stress strongly enough, however, that the sample set is too small and that additional data are required before definitive conclusions can be made.

Mittlefehldt, David W.; Peng, Z. X.

2013-01-01

186

Petrology and mineralogy of the Ningqiang carbonaceous chondrite  

NASA Astrophysics Data System (ADS)

We report detailed chemical, petrological, and mineralogical studies on the Ningqiang carbonaceous chondrite. Ningqiang is a unique ungrouped type 3 carbonaceous chondrite. Its bulk composition is similar to that of CV and CK chondrites, but refractory lithophile elements (1.01 × CI) are distinctly depleted relative to CV (1.29 × CI) and CK (1.20 × CI) chondrites. Ningqiang consists of 47.5 vol% chondrules, 2.0 vol% Ca,Al-rich inclusions (CAIs), 4.5 vol% amoeboid olivine aggregates (AOAs), and 46.0 vol% matrix. Most chondrules (95%) in Ningqiang are Mgrich. The abundances of Fe-rich and Al-rich chondrules are very low. Al-rich chondrules (ARCs) in Ningqiang are composed mainly of olivine, plagioclase, spinel, and pyroxenes. In ARCs, spinel and plagioclase are enriched in moderately volatile elements (Cr, Mn, and Na), and low-Ca pyroxenes are enriched in refractory elements (Al and Ti). The petrology and mineralogy of ARCs in Ningqiang indicate that they were formed from hybrid precursors of ferromagnesian chondrules mixed with refractory materials during chondrule formation processes. We found 294 CAIs (55.0% type A, 39.5% spinel-pyroxene-rich, 4.4% hibonite-rich, and several type C and anorthite-spinelrich inclusions) and 73 AOAs in 15 Ningqiang sections (equivalent to 20 cm2 surface area). This is the first report of hibonite-rich inclusions in Ningqiang. They are texturally similar to those in CM, CH, and CB chondrites, and exhibit three textural forms: aggregates of euhedral hibonite single crystals, fine-grained aggregates of subhedral hibonite with minor spinel, and hibonite ± Al,Ti-diopside ± spinel spherules. Evidence of secondary alteration is ubiquitous in Ningqiang. Opaque assemblages, formed by secondary alteration of pre-existing alloys on the parent body, are widespread in chondrules and matrix. On the other hand, nepheline and sodalite, existing in all chondritic components, formed by alkali-halogen metasomatism in the solar nebula.

Wang, Y.; Hsu, W.

2009-07-01

187

The Virtual Ocean  

NSDL National Science Digital Library

At this site, students examine larve, crustaceans, algae, and other microscopic organisms that inhabit the oceans. The site provides exceptional images and basic information about the organism's anatomy and development. There are also links to sites about freshwater microscopic organisms.

Van Egmond, Wim

2007-12-12

188

Testing microscopic discretization  

NASA Astrophysics Data System (ADS)

What can we say about the spectra of a collection of microscopic variables when only their coarse-grained sums are experimentally accessible? In this paper, using the tools and methodology from the study of quantum nonlocality, we develop a mathematical theory of the macroscopic fluctuations generated by ensembles of independent microscopic discrete systems. We provide algorithms to decide which multivariate Gaussian distributions can be approximated by sums of finitely valued random vectors. We study non-trivial cases where the microscopic variables have an unbounded range, as well as asymptotic scenarios with infinitely many macroscopic variables. From a foundational point of view, our results imply that bipartite Gaussian states of light cannot be understood as beams of independent d-dimensional particle pairs. It is also shown that the classical description of certain macroscopic optical experiments, as opposed to the quantum one, requires variables with infinite cardinality spectra.

Navascués, Miguel; Pérez-García, David; Villanueva, Ignacio

2013-03-01

189

Task-based and stable telenanomanipulation in a nanoscale virtual environment  

Microsoft Academic Search

In a haptic interface system with a nanoscale virtual environment (NVE) using an atomic force microscope, not only is stability important, but task-based performance (or fidelity) is crucial. In this paper, we introduce a nanoscale virtual coupling (NSVC) concept and explicitly derive the relationship between performance, stability, and scaling factors of velocity (or position) and force. An available scaling factor

Sung-Gaun Kimand; Metin Sitti

2006-01-01

190

Virtual reality exposure therapy  

PubMed Central

It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first controlled study of virtual reality in treatment of a psychiatric disorder. A case study supported the efficacy of VR exposure therapy for the fear of flying. The potential for virtual reality exposure treatment for these and other disorders is explored, and therapeutic issues surrounding the delivery of VR exposure are discussed.

Rothbaum, BO; Hodges, L; Kooper, R

1997-01-01

191

Virtual reality exposure therapy.  

PubMed

It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer-generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first controlled study of virtual reality in treatment of a psychiatric disorder. A case study supported the efficacy of VR exposure therapy for the fear of flying. The potential for virtual reality exposure treatment for these and other disorders is explored, and therapeutic issues surrounding the delivery of VR exposure are discussed. PMID:9185067

Rothbaum, B O; Hodges, L; Kooper, R

1997-01-01

192

MITRE's virtual model shop  

NASA Astrophysics Data System (ADS)

The exploration of visual data and the use of visual information during the design process can be greatly enhanced by working within the virtual environment where the user is closely coupled to the data by means of immersive technologies and natural user interfaces. Current technology enables us to construct a virtual environment utilizing 3D graphics projection, object generated stereo sound, tactile feedback, and voice command input. Advances in software architectures and user interfaces enable us to focus on enhancing the design process within the virtual environment. These explorations at MITRE have evolved into an application which focuses on the ability to create, manipulate, and explore photo and audio realistic 3D models of work spaces, office complexes, and entire communities in real-time. This application, the Virtual Interactive Planning System, is a component of the MITRE virtual model shop, a suite of applications which permits the user to design and manipulate computer graphics models within the virtual environment.

Wingfield, Michael A.

1995-04-01

193

Electron microscope studies  

SciTech Connect

This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

Crewe, A.V.; Kapp, O.H.

1992-07-01

194

Teaching Petrology in the 21st Century: A Workshop Report and Call to Action  

NASA Astrophysics Data System (ADS)

Petrology plays an important role in the upper division geology curriculum, introducing students to the skills needed to investigate and interpret igneous and metamorphic rocks that form the bulk of the earth's interior. Central concepts in petrology courses typically include chemical differentiation of Earth, the role of igneous and metamorphic processes in the Earth system, and the occurrences and distribution of rocks and in a variety of tectonic settings. Seventy-nine geoscientists who teach (or plan to teach) petrology in the undergraduate curriculum gathered for a week at Montana State University this past summer to discuss best practices and how petrology should be integrated into the geology curriculum of the 21st century. The first three days of the workshop were devoted to visiting some of the classic geological field locations in Montana and Wyoming to discuss the role of fieldwork in teaching petrologic concepts. The following four days were spent on the MSU campus in a mixture of large group discussions, smaller topical working group meetings, and demonstration sessions where faculty presented exercises, laboratory activities, or moderated small group discussions on pedagogy and assessment. One of the main outcomes of the workshop was the development of a web site for sharing teaching materials (http://serc.carleton.edu/NAGTWorkshops/petrology03). This site contains a complete record of workshop activities. A collection of over 200 digital resources that support teaching petrology is now available, including over 30 new instructional activities contributed by workshop participants. Each activity contains 1) a brief introduction to the activity; 2) the activity itself along with supporting documents such as teaching notes and an answer key; and 3) a place for comments by users to give feedback to the author and to those who might be interested in using the activity. A formal review process of these resources will be initiated in the coming year. Another important outcome of the workshop was the formation of working groups around five areas: development of rock suites, modeling and databases, experiments in petrology, phase equilibria, and geodynamic petrology. These working groups began the process of organizing existing resources for dissemination, identifying important gaps in coverage, and developing plans to create new resources in these areas for educators. Overall, workshop participants advocated the need to establish stronger ties between petrology and the larger geology curriculum, to better articulate the contributions of petrology in understanding the Earth system, and to develop better activities and strategies to motivate students to learn petrology. The goal of the workshop and of this session is to learn from each other the best practices in teaching petrology, to expand the participation in these activities, and to call for help in the development of new resources and methods for teaching petrology throughout the geoscience curriculum. Contributions to the Teaching Petrology website and participation in the working groups is strongly encouraged and open to everyone in the community. This workshop is part of the NAGT On The Cutting Edge workshop series, and was supported by funds from the NSF CCLI-ND program.

Mogk, D.; Davidson, C.; Manduca, C.; Braday, J.

2003-12-01

195

Flirting with virtual reality.  

PubMed

Psychoanalysis encourages patients to experience a virtual reality of the psychoanalytic relationship, in which both image and wish can be experimented with. Originally, the patient's awareness was supposed to move back and forth between the virtual and the actual, in a flickering and uncertain fashion. That is uncomfortable, and analysts have often preferred the domain of virtuality or of actuality, or have denied the distinction altogether. Recent philosophical developments and doubts about transference neurosis and reconstruction further tempt analysts to relax the flickering uncertainty of virtual and actual. Patient and analyst may gain comfort but lose something in the process. PMID:16104333

Friedman, Lawrence

2005-07-01

196

An experimental study of pathologist's navigation patterns in virtual microscopy  

PubMed Central

In virtual microscopy, a sequential process of captures of microscopical fields, allows to construct a virtual slide which is visualized using a specialized software, called the virtual microscopy viewer. This tool allows useful exploration of images, composed of thousands of microscopical fields of view at different levels of magnification, emulating an actual microscopical examination. The aim of this study was to establish the main pathologist's navigation patterns when exploring virtual microscopy slides, using a graphical user interface, adapted to the pathologist's workflow. Four pathologists with a similar level of experience, graduated from the same pathology program, navigated six virtual slides. Different issues were evaluated, namely, the percentage of common visited image regions, the time spent at each and its coincidence level, that is to say, the region of interest location. In addition, navigation patterns were also assessed, i.e., mouse movement velocities and linearity of the diagnostic paths. Results suggest that regions of interest are determined by a complex combination of the visited area, the time spent at each visit and the coincidence level among pathologists. Additionally, linear trajectories and particular velocity patterns were found for the registered diagnostic paths.

2010-01-01

197

Laser Projection Microscope  

NSDL National Science Digital Library

In this activity, learners use a laser pointer to project a microscopic image of a liquid sample suspended from the tip of a syringe. This activity includes step by step instructions with helpful photographs and a video showcasing the projection images. This activity involves lasers, syringes, and stagnant water, so learners should exercise caution and adult supervision is recommended.

Ragan, Sean M.

2011-01-01

198

Microscope on Mars  

NASA Technical Reports Server (NTRS)

This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

2004-01-01

199

Nanolithography with Electron Microscopes.  

National Technical Information Service (NTIS)

The use of a Philips Scanning Electron Microscope (PSEM) 500 in making ultra small devices is described. The PSEM 500 is equipped with a pattern generator. Accurate adjustment of the beam is essential for good results. To overcome the poor signal to noise...

1991-01-01

200

The Scanning Tunneling Microscope  

NSDL National Science Digital Library

This site from the Physics Department at Davidson College presents an overview of the scanning tunneling microscope (STM) as well as the results of an experiment conducted by the authors. They discuss the construction of two different types of probe tips and their use for imaging graphite and molybdenum disulfide. A section of images they obtained using the STM is also included.

Jr., John A.; Neumann, Doug; College, Davidson

201

Exploring Tools: Special Microscopes  

NSDL National Science Digital Library

In this activity, learners use a flexible magnet as a model for a scanning probe microscope (SPM). They learn that SPMs are an example of a special tool that scientists use to work on the nanoscale. Use this activity to talk about different tools that scientists use to study the nanoscale.

Network, Nanoscale I.; Sciencenterw

2010-01-01

202

Microscopes and ocular infections.  

PubMed

Environmental microbial assays of industrial microscope eyepieces were conducted following reports of multiple intershift ocular infections. Pathogenic Staphylococcus aureus was identified among the microorganisms cultured. This paper suggests that direct contact with industrial microscope eyepieces provides a potentially significant route of transmission of both bacterial and viral ocular infections. An industrial hygiene ocular health questionnaire was distributed to a first and second shift manufacturing operation to assess the incidence of ocular infections. These data were compared to the questionnaire responses of 122 control manufacturing workers who did not use microscopes. Based on self-reporting by employees, those who used microscopes were found to have statistically significant incidence of sites and conjunctivitis that was 8.3 times that of the control group. Sterilization of eyepieces by ethylene oxide, formaldehyde and isopropyl alcohol were considered, but ultimately rejected. These biocides were found respectively to damage ocular lens coatings, contribute to volatile organic emissions, or be ineffective against spore-forming bacteria. This article presents a detailed evaluation of a commercially available ultraviolet sanitization unit (manufactured by the King Bactostat Corp., 7115 Armistad Street, El Paso, TX 79912). This ultraviolet disinfection process proved to be rapid and emission free; it also yielded eyepieces free of residual chemical biocides that have the potential for ocular irritation. Field tests involving 60 eyepieces demonstrated effective disinfection by a Chi-Square statistical comparison, at values greater than 95% confidence level, as compared to unirradiated eyepieces. PMID:3591662

Olcerst, R B

1987-05-01

203

Virtual Classes, Real Policy  

ERIC Educational Resources Information Center

As Internet technology encroached on the public school classroom about a decade ago, Kim Ross, superintendent of the Houston (MN) School District saw an opportunity. The entrepreneurial spirit overtook Ross and his team, and out of that was born the Minnesota Virtual Academy and the Minnesota Center of Online Learning, or MCoOL--two virtual

Beem, Kate

2010-01-01

204

Crowded collaborative virtual environments  

Microsoft Academic Search

We introduce a framework for supporting crowds of participants in collaborative virtual environments (CVEs). The framework is realised as an extension to our previous spatial model of interaction and aims to provide greater scaleability and flexibility for communication between the inhabitants of virtual worlds. Our framework introduces an explicit crowd mechanism into CVEs in order to support the formation and

Steve Benford; Chris Greenhalgh; David Lloyd

1997-01-01

205

MITRE's virtual model shop  

Microsoft Academic Search

The exploration of visual data and the use of visual information during the design process can be greatly enhanced by working within the virtual environment where the user is closely coupled to the data by means of immersive technologies and natural user interfaces. Current technology enables us to construct a virtual environment utilizing 3D graphics projection, object generated stereo sound,

Michael A. Wingfield

1995-01-01

206

JHU Virtual laboratory  

NSDL National Science Digital Library

This virtual laboratory, which accompanies the Johns Hopkins University course "500.101 What is Engineering?" uses JAVA interactive technology to offer students experiment-oriented problems via the WWW or CD-ROM. The objective of the course and the virtual laboratory is to introduce beginning science and engineering students to

Karweit, Michael

207

Virtual Schools. Literature Review  

ERIC Educational Resources Information Center

The majority of school districts in the U.S. are providing some form of online learning for their students. In the past, virtual schools primarily targeted advanced students who didn't have access to certain courses in their regular schools. Recently, however, many virtual schools have shifted their focus to credit recovery as a way to provide…

Blazer, Christie

2009-01-01

208

Virtual seismic interpretation  

Microsoft Academic Search

This paper presents an application of the virtual reality paradigm to scientific visualization. We describe how the seismic interpretation task performed in oil and gas companies can be facilitated by using immersion techniques inherent to virtual reality. The feeling of immersion allows an easier and better understanding and manipulation of the three-dimensional data associated with seismic interpretation. Volume rendering is

L. A. Lima; R. Bastos

1998-01-01

209

A Virtual Good Idea  

ERIC Educational Resources Information Center

School districts across the country have always had to do more with less. Funding goes only so far, leaving administrators and IT staff to find innovative ways to save money while maintaining a high level of academic quality. Creating virtual servers accomplishes both tasks, district technology personnel say. Virtual environments not only allow…

Bolch, Matt

2009-01-01

210

Teaching the Virtual Presentation  

ERIC Educational Resources Information Center

Today, the virtual presentation is catching on rapidly in small, medium, and large businesses alike. A virtual presentation is one delivered live from a desktop or laptop computer to an audience anywhere in the world where there is Internet access. These new Web-based technologies are easy to use and inexpensive, making them readily accessible for…

Flatley, Marie E.

2007-01-01

211

Making virtual baby alive  

Microsoft Academic Search

We have designed and implemented a prototype virtual environment for medical training in neonatal resuscitation. The central element of this environment is the dynamic virtual model (avatar) of a new-born child, built using VRML and Java. Physiological variables relevant for training were chosen to be represented through the avatar: heart rate, respiration rate, skin colour and activity level (such as

D. KoroSecl; L. P. Halamek; D. Zazula

2001-01-01

212

Interactive virtual angioscopy  

Microsoft Academic Search

Virtual angioscopy is a non invasive medical procedure for explor- ing parts of the human vascular system. We have developed an in- teractive tool that takes as input data acquired with standard med- ical imaging modalities and regards it as a virtual environment to be interactively inspected. The system supports real-time naviga- tion with stereoscopic direct volume rendering and dynamic

Enrico Gobbetti; Piero Pili; Antonio Zorcolo; Massimiliano Tuveri

1998-01-01

213

Virtual Worlds for Educators  

ERIC Educational Resources Information Center

This article describes an online experience that has not only created a fantasy world for the general public but has enabled some tech-savvy educators to create virtual educational opportunities. Second Life, or SL, is a 3-D Internet-based virtual world created by Linden Lab and populated by nearly 1,000,000 active users worldwide since 2003.…

Dembo, Steve

2008-01-01

214

Virtual german cockroach  

NSDL National Science Digital Library

3D virtual image of a German Cockroach (Family Blattidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

215

Virtual yellowjacket wasp  

NSDL National Science Digital Library

3D virtual image of a yellowjacket wasp (Family Vespidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

216

Virtual water strider  

NSDL National Science Digital Library

3D virtual image of a water strider (Family Gerridae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

217

[Application of data fusion of microscopic spectral imaging in reservoir characterization].  

PubMed

In recent years, spectral imaging technique has been applied widely in mineralogy and petrology. The technique combines the spectral technique with imaging technique. The samples can be analyzed and recognized both in spectra and space by using the technique. However, the problem is how to acquire the needful information from a large number of data of spectral imaging, and how to enhance the needful information. In the present paper, the experimental data were processed by using the technique of data fusion of microscopic spectral imaging. The space distribution map of chemical composition and physical parameters of samples were obtained. The result showed that the distribution of different hydrocarbon in the reservoirs, pore connectivity, etc. were revealed well. The technique of data fusion of microscopic spectral imaging provided a new method for reservoir characterization. PMID:22250524

Li, Jing; Zha, Ming; Guo, Yuan-Ling; Chen, Yong

2011-10-01

218

Petrology and Reservoir Paragenesis in the Sussex 'B' Sandstone of the Upper Cretaceous Cody Shale, House Creek and Porcupine Fields, Powder River Basin, Wyoming.  

National Technical Information Service (NTIS)

Using petrologic and sedimentologic studies, the paper characterizes the influence of sedimentologic and petrologic variations on reservoir heterogeneity in the Sussex 'B' sandstone in the House Creek and Porcupine fields, Powder River Basin, Wyoming. Eff...

D. K. Higley

1991-01-01

219

Petrologic predictions regarding future eruptive activity at Mount Hood, Oregon  

NASA Astrophysics Data System (ADS)

Mount Hood, Oregon, represents a volcano that has a significant chance of erupting within the next few decades, but that has experienced no observed eruptions that provide direct geophysical or other constraints on eruption mechanisms and dynamics. In this case, petrological studies provide important insights into the potential nature of future eruptions, and these can be used to consider the geophysical and other signals that might accompany any renewed activity, and the timescales over which these might occur. In this contribution we present a summary of recent petrological work at Mount Hood and highlight data that provide insight into the likely nature of future eruptions. One of the most important features of Mount Hood lavas is the widespread evidence for magma mixing and mafic recharge. Andesites and low silica dacites from previous eruptive phases formed via mixing and hybridization between hotter ascending mafic magma and a long-lived crystal rich silicic magma or mush stored at shallow depths beneath the volcano. Mineral zoning studies show that mixing only occurs immediately prior to eruption, and we infer recharge of mafic magma into a shallow crustal magma storage zone is the predominant means by which eruptions of Mount Hood are initiated. Ascent of mafic magma and recharge would likely be accompanied by seismic, deformation and other detectable geophysical signals. Mineral barometry shows that amphiboles associated with shallow silicic magma formed at ~3-6 km, which we interpret to represent the depth of shallow silicic magma storage, and the depth at which recharge and mixing occurs. Amphiboles crystallized from mafic magma formed at ~10-16 km depth during magma ascent. Thus deeper earthquakes might accompany initial movement of mafic magma and more shallow seismic activity may occur during the convective overturn associated with recharge, mixing and final ascent of the hybridized magma. High-SiO2 melt inclusions in erupted lavas also contain low sulfur contents, thus mafic recharge and mixing should also be accompanied by the release of significant amounts of SO2 derived from mafic magma. Diffusion modeling based in mineral rim compositions suggests that the period between mafic recharge and eventual eruption and quenching is quite short - weeks to a few months at most, consistent with studies of other andesitic volcanoes. This provides an estimate of the potential time period that might elapse between detection of geophysical and other data indicative of recharge and mixing and magma reaching the surface.

Kent, A. J.; Koleszar, A. M.

2012-12-01

220

Ion photon emission microscope  

DOEpatents

An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

Doyle, Barney L. (Albuquerque, NM)

2003-04-22

221

Photothermal multipixel imaging microscope  

NASA Astrophysics Data System (ADS)

Photothermal microscopy is a useful nondestructive tool for the identification of fluence-limiting defects in optical coatings. Traditional photothermal microscopes are single-pixel detection devices. Samples are scanned under the microscope to generate a defect map. For high-resolution images, scan times can be quite long (1 mm2 per hour). Single-pixel detection has geen used traditionally because of the ease in separating the laser-induced topographical change due to defect absorption from the defect surface topography. This is accomplished by using standard chopper and lock-in amplifier techniques to remove the DC signal. Multi-pixel photothermal microscopy is now possible by utilizing an optical lock-in technique. This eliminates the lock-in amplifier and enables the use of a CCD camera with an optical lock in for each pixel. With this technique, the data acquisition speed can be increased by orders of magnitude depending on laser power, beam size, and pixel density.

Stolz, Christopher J.; Chinn, Diane J.; Huber, Robert D.; Weinzapfel, Carolyn L.; Wu, Zhouling

2004-06-01

222

Virtual Worlds, Virtual Literacy: An Educational Exploration  

ERIC Educational Resources Information Center

Virtual worlds enable students to learn through seeing, knowing, and doing within visually rich and mentally engaging spaces. Rather than reading about events, students become part of the events through the adoption of a pre-set persona. Along with visual feedback that guides the players' activities and the development of visual skills, visual…

Stoerger, Sharon

2008-01-01

223

Confocal THz Laser Microscope  

Microsoft Academic Search

We transfer the principle of the optical confocal microscope to a far-field THz imaging system based on an optically pumped\\u000a gas laser emitting radiation at 2.52 THz. This results in a contrast enhancement. To illustrate the image quality improvement,\\u000a we show THz images of different objects taken with the suggested scheme and compare them to images taken with other systems.

Mohammed Adnan Salhi; Ioachim Pupeza; Martin Koch

2010-01-01

224

Microscopic and macroscopic dynamics  

SciTech Connect

Atomistic Molecular Dynamics and Lagrangian Continuum Mechanics can be very similarly adapted to massively-parallel computers. Millions of degrees of freedom can be treated. The two complementary approaches, microscopic and macroscopic, are being applied to increasingly realistic flows of fluids and solids. The two approaches can also be combined in a hybrid simulation scheme. Hybrids combine the fundamental constitutive advantage of atoms with the size advantage of the continuum picture.

Hoover, W.G.; Hoover, C.G.; De Groot, A.J.; Pierce, T.G. [California Univ., Davis, CA (United States). Dept. of Applied Science]|[Lawrence Livermore National Lab., CA (United States)

1993-06-01

225

Virtual Machine Logbook - Enabling virtualization for ATLAS  

NASA Astrophysics Data System (ADS)

ATLAS software has been developed mostly on CERN linux cluster lxplus or on similar facilities at the experiment Tier 1 centers. The fast rise of virtualization technology has the potential to change this model, turning every laptop or desktop into an ATLAS analysis platform. In the context of the CernVM project we are developing a suite of tools and CernVM plug-in extensions to promote the use of virtualization for ATLAS analysis and software development. The Virtual Machine Logbook (VML), in particular, is an application to organize work of physicists on multiple projects, logging their progress, and speeding up "context switches" from one project to another. An important feature of VML is the ability to share with a single "click" the status of a given project with other colleagues. VML builds upon the save and restore capabilities of mainstream virtualization software like VMware, and provides a technology-independent client interface to them. A lot of emphasis in the design and implementation has gone into optimizing the save and restore process to makepractical to store many VML entries on a typical laptop disk or to share a VML entry over the network. At the same time, taking advantage of CernVM's plugin capabilities, we are extending the CernVM platform to help increase the usability of ATLAS software. For example, we added the ability to start the ATLAS event display on any computer running CernVM simply by clicking a button in a web browser. We want to integrate seamlessly VML with CernVM unique file system design to distribute efficiently ATLAS software on every physicist computer. The CernVM File System (CVMFS) download files on-demand via HTTP, and cache it locally for future use. This reduces by one order of magnitude the download sizes, making practical for a developer to work with multiple software releases on a virtual machine.

Yao, Yushu; Calafiura, Paolo; Poffet, Julien; Cavalli, Andrea; Leggett, Charles; Frédéric, Bapst

2010-04-01

226

[Virtual + 1] * Reality  

NASA Astrophysics Data System (ADS)

Virtual Reality aims at creating an artificial environment that can be perceived as a substitute to a real setting. Much effort in research and development goes into the creation of virtual environments that in their majority are perceivable only by eyes and hands. The multisensory nature of our perception, however, allows and, arguably, also expects more than that. As long as we are not able to simulate and deliver a fully sensory believable virtual environment to a user, we could make use of the fully sensory, multi-modal nature of real objects to fill in for this deficiency. The idea is to purposefully integrate real artifacts into the application and interaction, instead of dismissing anything real as hindering the virtual experience. The term virtual reality - denoting the goal, not the technology - shifts from a core virtual reality to an “enriched” reality, technologically encompassing both the computer generated and the real, physical artifacts. Together, either simultaneously or in a hybrid way, real and virtual jointly provide stimuli that are perceived by users through their senses and are later formed into an experience by the user's mind.

Beckhaus, Steffi

227

Virtual stag beetle  

NSDL National Science Digital Library

3D image of a stage beetle (Family Lucanidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

228

Isotopic, petrologic and biogeochemical investigations of banded iron-formations  

NASA Technical Reports Server (NTRS)

It is recognized that the first occurrence of banded iron-formations (BIFs) clearly predates biological oxygenation of the atmosphere-hydrosphere system and that their last occurrences extend beyond plausible dates of pervasive biological oxygenation. For this reason, and because enormous quantities of oxidizing power have been sequestered in them, it is widely thought that these massive, but enigmatic, sediments must encode information about the mechanism and timing of the rise of atmospheric O2. By coupling isotopic analyses of iron-formation carbonates with biogeochemical and petrologic investigations, we are studying (1) the mechanism of initial sedimentation of iron; (2) the role of iron in microbially mediated diagenetic processes in fresh iron-formation sediments; and (3) the logical integration of mechanisms of deposition with observed levels of banding. Thus far, it has been shown that (1) carbonates in BIFs of the Hamersley Group of Western Australia are isotopically inhomogenous; (2) the nature and pattern of isotopic ordering is not consistent with a metamorphic origin for the overall depletion of C-13 observed in the carbonates; (3) if biological, the origin of the C-13 depleted carbonate could be either respiratory or fermentative; (4) iron may have been precipitate d as Fe(3+), then reduced to Fe(2+) within the sediment; and (5) sedimentary biogeochemical systems may have been at least partially closed to mass transport of carbonate species.

Hayes, J. M.; Kaufman, A. J.; Klein, C.; Studley, S. A.; Baur, M. E.; Walter, M. R.

1986-01-01

229

Handheld Micromanipulation with Vision-Based Virtual Fixtures.  

PubMed

Precise movement during micromanipulation becomes difficult in submillimeter workspaces, largely due to the destabilizing influence of tremor. Robotic aid combined with filtering techniques that suppress tremor frequency bands increases performance; however, if knowledge of the operator's goals is available, virtual fixtures have been shown to greatly improve micromanipulator precision. In this paper, we derive a control law for position-based virtual fixtures within the framework of an active handheld micromanipulator, where the fixtures are generated in real-time from microscope video. Additionally, we develop motion scaling behavior centered on virtual fixtures as a simple and direct extension to our formulation. We demonstrate that hard and soft (motion-scaled) virtual fixtures outperform state-of-the-art tremor cancellation performance on a set of artificial but medically relevant tasks: holding, move-and-hold, curve tracing, and volume restriction. PMID:23275860

Becker, Brian C; Maclachlan, Robert A; Hager, Gregory D; Riviere, Cameron N

2011-08-18

230

Handheld Micromanipulation with Vision-Based Virtual Fixtures  

PubMed Central

Precise movement during micromanipulation becomes difficult in submillimeter workspaces, largely due to the destabilizing influence of tremor. Robotic aid combined with filtering techniques that suppress tremor frequency bands increases performance; however, if knowledge of the operator's goals is available, virtual fixtures have been shown to greatly improve micromanipulator precision. In this paper, we derive a control law for position-based virtual fixtures within the framework of an active handheld micromanipulator, where the fixtures are generated in real-time from microscope video. Additionally, we develop motion scaling behavior centered on virtual fixtures as a simple and direct extension to our formulation. We demonstrate that hard and soft (motion-scaled) virtual fixtures outperform state-of-the-art tremor cancellation performance on a set of artificial but medically relevant tasks: holding, move-and-hold, curve tracing, and volume restriction.

Becker, Brian C.; MacLachlan, Robert A.; Hager, Gregory D.; Riviere, Cameron N.

2011-01-01

231

Q: How do Microscopes Work?  

ERIC Educational Resources Information Center

Microscopes allow scientists to examine everyday objects in extraordinary ways. They provide high-resolution images that show objects in fine detail. This brief article describes the many types of microscopes and how they are used in different scientific venues.

Zimov, Sarah

2004-01-01

232

The University of Virginia Virtual Lab  

NSDL National Science Digital Library

This website offers various virtual laboratory experiences in electrical science and technology using 3D animations and interactive models. Topics covered range from basic electricity and magnetism to modern topics in semiconductor physics, microelectronics, and nanotechnology fabrication and instrumentation. The approach covers the material at a level that is understandable to high school and introductory undergraduates but covers all details, such as semiconductor structures and electronic device design, necessary for a complete understanding of the technology. Models are used to explain microscopic physical concepts. This project is supported by grants from the National Science Foundation, the University of Virginia, IBM, and Discreet Corporation.

Bean, John

2006-07-05

233

Science Nation: Virtual Self  

NSDL National Science Digital Library

An avatar is a movable image that people design to represent themselves in virtual reality environments or in cyberspace. Avatars are usually for fun and games but could avatars actually change us? Jeremy Bailenson thinks so. With support from the National Science Foundation (NSF), he created the Virtual Human Interaction Lab (VHIL) at Stanford University to study, among other things, the power avatars exert on their real world masters. Sometimes, avatars are designed to be ideal versions of their creators, and there's now evidence that the virtual reality persona begins to influence the real life persona.

234

Thermal waste treatment and resource management - a petrologic approach to control the genesis of materials in smelting processes  

Microsoft Academic Search

Primary stores in the sense of geogenic mineral deposits (ores and stones) are diminishing, while the corresponding stocks in urban settlement are increasing accordingly. In this situation, concepts are required to use both the remaining primary resources and the secondary resources more efficiently. Petrologic evaluation is an approach in this context. Petrologic evaluation includes the combination of know-how and tools

Christoph Zeltner; Thomas Lichtensteiger

2002-01-01

235

NoHype: virtualized cloud infrastructure without the virtualization  

Microsoft Academic Search

Cloud computing is a disruptive trend that is changing the way we use computers. The key underlying technology in cloud infrastructures is virtualization -- so much so that many consider virtualization to be one of the key features rather than simply an implementation detail. Unfortunately, the use of virtualization is the source of a significant security concern. Because multiple virtual

Eric Keller; Jakub Szefer; Jennifer Rexford; Ruby B. Lee

2010-01-01

236

Sedimentology, petrology, and geotechnical properties of Athabasca oil sands, Alberta  

Microsoft Academic Search

The Athabasca oil sands deposit is not only one of the largest petroleum reservoirs in the world (870 billion bbl of oil in place), it is virtually the only supergiant oil accumulation that can be examined at outcrop. Sedimentologic and petrographic knowledge, gleaned both from the outcrop and from many subsurface cores, has direct and immediate implication for surface mining

M. B. Dusseault; G. D. Mossop

1979-01-01

237

Quantitative and Qualitative Changes in Teaching Histology by Means of Virtual Microscopy In an Introductory Course in Human Anatomy  

NSDL National Science Digital Library

This article describes a study investigating the learning impact of using virtual microscopy versus the tradition optical microscope in an undergraduate anatomy course. The study used lab averages, individual test scores, and survey results to compare differences.

Polly Husmann (Indiana University School of Medicine Medical Sciences Program); PhD Valerie Dean O'Loughlin (Indiana University Medical Sciences Program)

2009-09-14

238

Adirondack Under the Microscope  

NASA Technical Reports Server (NTRS)

This image was taken by the Mars Exploration Rover Spirit front hazard-identification camera after the rover's first post-egress drive on Mars Sunday, Jan. 15, 2004. Engineers drove the rover approximately 3 meters (10 feet) from the Columbia Memorial Station toward the first rock target, seen in the foreground. The football-sized rock was dubbed Adirondack because of its mountain-shaped appearance. Scientists have begun using the microscopic imager instrument at the end of the rover's robotic arm to examine the rock and understand how it formed.

2004-01-01

239

Solid state optical microscope  

DOEpatents

A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal. 2 figs.

Young, I.T.

1983-08-09

240

Solid state optical microscope  

DOEpatents

A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

Young, Ian T. (Pleasanton, CA)

1983-01-01

241

Jefferson Lab Virtual Tour  

ScienceCinema

Take a virtual tour of the campus of Thomas Jefferson National Accelerator Facility. You can see inside our two accelerators, three experimental areas, accelerator component fabrication and testing areas, high-performance computing areas and laser labs.

None

2014-05-22

242

Virtual Field Trips  

NSDL National Science Digital Library

These virtual field trips allow students to explore plant and animal life in South CarolinaâÂÂs ecosystemsâÂÂa cove forest and a salt marshâÂÂand to understand the threats to these fragile systems.

Barbara Jean Speziale (Clemson University;)

2010-06-18

243

World Virtual Observatory Organization  

NASA Astrophysics Data System (ADS)

On the base of experience of our Unoversity and Observatory we investigate the seven blocks model of virtual organization for consolidation of resources. This model consists of the next blocks: 1.Population-scientists students robots and agents. 2.Aspiration of population groups. 3.Territory. 4.Production. 5.Ecology and safety. 6.Finance. 7. External relations - input and output flows of population information resources.The world virtual observatory is the virtual world which consists of three groups of variables - appearances essences and structured uncertainty which defines the number and distribution of arbitrary coefficients in equivalent equations. The consolodation of recources permit to create the large telescopes with distributed structure on our planet and cosmos. Virtual instruments can have the best characteristics by means of collective effects which have investigated in our paper.

Ignatyev, Mikhail; Pinigin, Gennadij

244

Jefferson Lab Virtual Tour  

SciTech Connect

Take a virtual tour of the campus of Thomas Jefferson National Accelerator Facility. You can see inside our two accelerators, three experimental areas, accelerator component fabrication and testing areas, high-performance computing areas and laser labs.

None

2013-07-13

245

Base Blocks Virtual Manipulative  

NSDL National Science Digital Library

This virtual manipulative provides base blocks that consist of individual "units," "longs," "flats," and "blocks" (ten of each set for base 10). They can be used to show place value for numbers and to increase understanding of addition and subtraction.

Manipulatives, National L.

2008-12-10

246

Virtual item purchase behavior in virtual worlds: an exploratory investigation  

Microsoft Academic Search

Virtual worlds, such as Second Life, World of Warcraft and Everquest, have demonstrated huge economic potential. In such virtual\\u000a worlds, virtual items are bought and sold between individuals for real money. However, little empirical research has been\\u000a conducted into players’ purchase behavior in virtual worlds. To help us gain a better understanding of factors influencing\\u000a purchase behavior in virtual worlds,

Yue Guo; Stuart Barnes

2009-01-01

247

Intercepting Virtual Ball in Immersive Virtual Environment  

Microsoft Academic Search

\\u000a Catching a flying ball is a difficult task that requires sensory systems to calculate the precise trajectory of the ball to\\u000a predict its movement, and the motor systems to drive the hand in the right place at the right time.\\u000a \\u000a \\u000a In this paper we have analyzed the human performance in an intercepting task performed in an immersive virtual environment\\u000a and

Massimiliano Valente; Davide Sobrero; Andrea Brogni; Darwin Caldwell

248

The virtual wind tunnel  

Microsoft Academic Search

The design and implementation of a virtual environment linked to a graphics workstation for the visualization of complex fluid flows are described. The system user wears a stereo head-tracked display, which effectively displays 3-D information, and an instrumented glove to intuitively position flow-visualization tools. The visualization structures and their interfaces in the virtual environment and the implementation hardware and software

S. Bryson; C. Levit

1992-01-01

249

Virtual Courseware: Earthquake  

NSDL National Science Digital Library

This interactive exercise lets students investigate how seismic waves are used to locate the epicenter of an earthquake and determine its magnitude. They will place virtual seismic stations on an interactive map, trigger a virtual explosion, and measure the difference in arrival times of S- and P-waves generated by the explosion. Using this data, they can determine the distance to each station and use triangulation to determine the epicenter of the earthquake.

250

The Virtual Science Classroom  

NSDL National Science Digital Library

Virtual schooling offers students the opportunity to enroll in a science course not taught at their home school or school district, interact with expert instructors in a particular field, and gain access to subject matter they may have otherwise missed (i.e., teenage moms, home-schooled students, expelled students, etc.). This chapter examines best teaching practices emerging within this new field and showcases specific examples of how various technologies are used within virtual science classrooms.

Ferdig, Rick; Dana, Tom

2008-01-01

251

Virtual experiments and environmental policy  

Microsoft Academic Search

We develop the concept of virtual experiments and consider their application to environmental policy. A virtual experiment combines insights from virtual reality in computer science, naturalistic decision-making from psychology, and field experiments from economics. The environmental policy applications of interest to us are the valuation of wild fire management policies such as prescribed burn. The methodological objective of virtual experiments

Stephen M. Fiore; Glenn W. Harrison; Charles E. Hughes; E. Elisabet Rutström

2009-01-01

252

Virtual-channel flow control  

Microsoft Academic Search

Network throughput can be increased by dividing the buffer storage associated with each network channel into several virtual channels [DalSei]. Each physical channel is associated with several small queues, virtual channels, rather than a single deep queue. The virtual channels associated with one physical channel are allocated independently but compete with each other for physical bandwidth. Virtual channels decouple buffer

William J. Dally

1990-01-01

253

Interpretations of virtual reality.  

PubMed

University students were surveyed to learn what they know about virtual realities. The two studies were administered with a half-year interval in which the students (N=90, specializing either in mathematics and science, or in social science and humanities) were asked to name particular examples of virtual realities. The second, but not the first study, was administered after the participants had the chance to see the movie "Avatar" (no investigation was held into whether they really saw it). While the students in both studies widely believed that activities such as social networking and online gaming represent virtual realities, some other examples provided by the students in the two studies differ: in the second study the participants expressed a better understanding of the items related to virtual realities. At the same time, not a single participant reported particular psychological states (either regular or altered) as examples of virtual realities. Profound popularization efforts need to be done to acquaint the public, including college students, with virtual realities and let the public adequately understand how such systems work. PMID:21685638

Voiskounsky, Alexander

2011-01-01

254

Virtual Heritage Network  

NSDL National Science Digital Library

"The Virtual Heritage Network [VHN], is a new international organisation designed to promote the utilisation of technology for the education, interpretation, conservation and preservation of Natural, Cultural and World Heritage." The heart of VHN is a searchable library that consists of papers, articles, and reports "discussing applications, tools, games, [and] financial and legal aspects" of virtual heritage. Submissions are self-selected and given online reviews by site users, but everything we saw here was professional and, in most cases, had been published elsewhere in academic or news media forums. The site also lets users keep up to date with current developments in the virtual heritage industry via a newsletter, and for members (registration free), offers an email digest of recent submissions to the site, an electronic mailing list, and a forthcoming message board. For the uninitiated, the site has reprinted an article from the November edition of UNESCO's World Heritage Magazine explaining the concept of Virtual Heritage (available from the What is Virtual Heritage? link on the front page). The VHN was established this month by the International Society on Virtual Systems and MultiMedia (VSMM Society) with the support of the UNESCO World Heritage Centre.

255

Microscopic Rayleigh Droplet Beams  

NASA Astrophysics Data System (ADS)

A periodically triggered Rayleigh Droplet Beam (RDB) delivers a perfectly linear and periodic stream of identical, monoenergetic droplets that are phase-locked to the trigger signal. The droplet diameter and spacing are easily adjusted of choice of nozzle diameter and trigger frequency. Any liquid of low viscosity may be emloyed as the beam fluid. Although the field of nanofluidics is expanding rapidly, little effort has yet been devoted to ``external flows'' such as RDB's. At ASU we have generated RDB's of water and methanol down to 2 microns in droplet diameter. Nozzle clogging is the sole impediment to smaller droplets. Microscopic Rayleigh droplet beams offer tremendous potential for fundamental physical measurements, fluid dynamics research, and nanofabrication. This talk will describe the apparatus and techniques used at ASU to generate RDB's (surprisingly simple and inexpensive), discuss the triboelectric phenomena that play a role (surprisingly significant), present some initial experimental fluid dynamics measurements, and briefly survey RDB applications. Our particular interest in RDB's is as microscopic transport systems to deliver hydrated, undenatured proteins into vacuum for structure determination via serial diffraction of x-rays or electrons. This may offer the first general method for structure determination of non-crystallizable proteins.

Doak, R. B.

2005-11-01

256

Microscopic colitis. A review.  

PubMed

Microscopic colitis (MC) is characterized by a triad of watery diarrhea, usually normal colonoscopic findings and typical microscopic findings. Two distinct histological forms of MC have been defined: lymphocytic colitis and collagenous colitis, but overlapping features may be present. The incidence of MC appears to be rising and in some countries it may account for as many as 10-20% of patients with non-bloody watery diarrhea. The cause of MC remains unknown and is likely to be multifactorial. The pathogenesis is poorly defined, and numerous immunological abnormalities have been reported. MC is commonly associated with autoimmune diseases including celiac disease. Use of various medications, most notably non-steroidal anti-inflammatory agents and proton pump inhibitors, have been etiologically implicated but not firmly established as causative. In imperfect trials several agents have been reported to be effective in the treatment of MC; budesonide is the best studied and evidence supporting its effectiveness is the most persuasive. In cases of otherwise unexplained watery, non-bloody diarrhea, MC should be considered and colonic biopsied specimens should be taken of normal-appearing mucosa. PMID:23419063

Brown, William R; Tayal, Shalini

2013-06-01

257

Scanning Electron Microscope Room  

NASA Technical Reports Server (NTRS)

This image shows a scanning electron microscope (SEM). This instrument uses a highly-focused beam of electrons to provide visual images of the surface of materials at magnifications up to 20,000X or more. These high magnification images allow the researcher to identify details about the material's microstructure, such as the types and sizes of microscopic particles present. The beam of electrons can also be used to examine volumes (as small as 1 micrometer in diameter) of the material being analyzed to provide information about the chemistry. This information can be used to determine chemical variations as a function of location within the material's microstructure, as well as the chemical composition of individual particles. In addition, the SEM is equipped with sophisticated instrumentation that can determine the crystal structure of individual grains and how each grain is oriented with respect to neighboring grains within the material. The chemistry and crystal structure information can be related to fracture behavior and used to modify the manufacturing processes used to produce the material in order to improve its properties.

1996-01-01

258

Microscopic VECSEL modeling  

NASA Astrophysics Data System (ADS)

This tutorial gives an overview of the microscopic approach developed to describe equilibrium and nonequilibrium effects in optically excited semiconductor systems with an emphasis to the application for VECSEL modelling. It is outlined how nonequilibrium quantum theory is used to derive dynamic equations for the relevant physical quantities, i.e. the optically induced polarization and the dynamical carrier occupation probabilities. Due to the Coulombic many-body interactions, polarization and populations couple to expectation values of higher-order quantum correlations. With the help of a systematic correlation expansion and truncation approach, we arrive at a closed set of equations. Formally these can be combined with Maxwell's equations for the classical light field, yielding the Maxwell-semiconductor Bloch equations (MSBE). However, instead of the more traditional approach where losses and dissipative processes are treated phenomenologically and/or through coupling to external reservoirs, we derive fully microscopic equations for the carrier-carrier and carrier-phonon scattering as well as the effective polarization dephasing. Due to their general nature, the resulting equations are fully valid under most experimentally relevant conditions. The theory is applied to model the high-intensity light field in the VECSEL cavity coupled to the dynamics of the optical polarization and the nonequilibrium carrier distributions in the quantum-well gain medium.

Koch, S. W.; Hader, J.; Moloney, J. V.

2014-03-01

259

Virtual Cluster Management with Xen  

SciTech Connect

Recently, virtualization of hardware resources to run multiple instances of independent virtual machines over physical hosts has gained popularity due to an industry-wide focus on the need to reduce the cost of operation of an enterprise computing infrastructure. Xen is an open source hypervisor that provides a virtual machine abstraction layer which is very similar to the underlying physical machine. Using multiple physical hosts, each hosting multiple virtual machines over a VMM like Xen, system administrators can setup a high-availability virtual cluster to meet the ever-increasing demands of their data centers. In such an environment, the Xen hypervisor enables live migration of individual virtual machine instances from one physical node to another without significantly affecting the performance of the applications running on a target virtual machine. This paper describes a scalable Virtual Cluster Manager that provides such application agnostic cluster management capabilities to the system administrators maintaining virtual clusters over Xen powered virtual nodes.

Bhatia, Nikhil [ORNL; Vetter, Jeffrey S [ORNL

2008-01-01

260

Petrologic Insights into Magma System Response to Edifice Collapse  

NASA Astrophysics Data System (ADS)

In order to understand eruptive behavior at volcanic centers and to improve models for monitoring and prediction of volcanic eruptions, it is important to constrain magma storage conditions and transport in the system. Here the post-collapse eruptive behavior at Bezymianny and Shiveluch volcanoes, (Kamchatka Peninsula, Russia) are each compared to the well-known sequence at Mount St. Helens, Washington, USA (from 1956, 1964, and 1980, respectively). The magma system responds to rapid unloading of overburden pressure, due to edifice collapse, with a violent large-scale paroxysmal eruption. This reflects the amplitude of the triggering decompression event with later dome-building and explosive activity due to the reduction of vent elevation. The massive unloading events and post-collapse eruptive chronologies, provides a unique opportunity for comparison of the sources driving the catastrophic eruptions and eruptive style transitions. Analytical techniques employed included X-ray fluorescence spectroscopy, electron probe micro-analyses, Fe-Ti oxide and two-pyroxene geothermometry, X-ray elemental mapping, and a novel image processing technique. Presented here are results from petrological investigations into the temporal variations of whole-rock geochemistry, geothermometry, mineral modal abundances and textures. Bezymianny is becoming more mafic over time from 61.0 to 57.3 wt.% SiO2 (1956 and 2010). Pre-eruptive magma temperatures increased from 950oC to 1050oC from 1956 to 2006. Plagioclase and amphibole disequilibrium textures are observed throughout the time series and rare mafic enclaves exist. The whole-rock chemical trend at Shiveluch shows a subtle, yet reversed trend from 60.6 to 64.2 wt.% SiO2 (1964 and 2007). Two-pyroxene geothermometry yields ~950oC+30oC (2001-2007) and is consistent with data from the 2001 -2004 eruption, of 834-978oC+60oC. Mafic enclaves occurred throughout the entire period of eruptive activity at Shiveluch. In contrast to both Bezymianny and Shiveluch, the Mount St. Helens erupted a compositionally uniform crystal-rich dacite, 65 wt.% SiO2 in 2004. Magmatic temperatures from 1980-1981 ~930oC and in 2004-2006 they had decreased to ~850oC. At this stage, a continuous and possibly punctuated replenishment of mafic magma from depth appears to be driving the frequency of eruptions and observed transitions in eruptive style at Bezymianny. At Shiveluch, an increasingly silicic geochemical trend, high temperatures and the presence of mafic enclaves, may indicate a re-mobilization of host dacite by basalt ponded at the base of the deep seated magma reservoir. Models of magma replenishment and mixing at Bezymianny and Shiveluch are discussed in the context of magma system response to edifice collapse and compared to Mount St. Helens. It is demonstrated here, that petrologic studies serve to elucidate short-time scale behavior of these magmatic systems and to enable projections of future volcanic activity.

Shipman, J. S.; Izbekov, P. E.; Gavrilenko, M.

2011-12-01

261

Petrology and geochemistry of Iceland basalts: Spatial and temporal variations  

SciTech Connect

A petrological and geochemical study of basalts from Iceland's neovolcanic zones and Tertiary lava piles was carried out in order to investigate volcanic processes associated with the development of the Iceland platform, an anomalously elevated segment of the Mid-Atlantic Ridge (MAR). The Northeast and Southwest axial rift zones are dominated by olivine tholeiites and tholeiites, whereas the Southeast, Skagi, and Snaefellsnes flank zones are characterized by alkali basalts and mildly alkaline FeTi basalts. Phenocryst assemblages and textures are more diverse in flank zone basalts than in axial rift zone basalts, suggesting mixing of more diverse magma compositions and longer residence times in flank zone magma chambers. Geochemical trends observed in 2 to 14 m.y. old basalts from eastern and western Iceland indicate a complex and varied source region for Iceland magmas, dependent on both mantle plume activity and the maturity of rift zones. Decreasing (La/Sm){sub E.F.} and {sup 87}Sr/{sup 86}Sr ratios over the last 14 m.y. suggest decreasing mantle plume activity. Shorter episodes (2 to 5 m.y.) of declining (La/Sm){sub E.F.} and {sup 87}Sr/{sup 86}Sr are explained by the development of new rift zones caused by repeated shifts in the location of the spreading axis. On the average, Tertiary basalts from eastern and western Iceland are chemically more similar to young (< 0.7 m.y.) basalts from immature flank zones than to young basalts from the axial rift zones, implying that the Tertiary basalts were erupted along immature rift zones. Geochemical cycles, lasting 0.1 to 0.3 m.y., in the Borgarfjordur lava pile suggest progressive melting of mantle diapirs, rising from the garnet stability zone where melting begins.

Meyer, P.S.

1984-01-01

262

THz wave emission microscope  

NASA Astrophysics Data System (ADS)

Sensing and imaging using Terahertz (THz) radiation has attracted more and more interest in the last two decades thanks to the abundant material 'finger prints' in the THz frequency range. The low photon energy also makes THz radiation an attractive tool for nondestructive evaluation of materials and devices, biomedical applications, security checks and explosive screening. Due to the long wavelength, the far-field THz wave optical systems have relatively low spatial resolution. This physical limitation confines THz wave sensing and imaging to mostly macro-size samples. To investigate local material properties or micro-size structures and devices, near-field technology has to be employed. In this dissertation, the Electro-Optical THz wave emission microscope is investigated. The basic principle is to focus the femtosecond laser to a tight spot on a thin THz emitter layer to produce a THz wave source with a similar size as the focus spot. The apparatus provides a method for placing a THz source with sub-wavelength dimension in the near-field range of the investigated sample. Spatial resolution to the order of one tenth of the THz wavelength is demonstrated by this method. The properties of some widely used THz wave emission materials under tight focused pump light are studied. As an important branch of THz time domain spectroscopy (THz-TDS), THz wave emission spectroscopy has been widely used as a tool to investigate the material physics, such as energy band structure, carrier dynamics, material nonlinear properties and dynamics. As the main work of this dissertation, we propose to combine the THz wave emission spectroscopy with scanning probe microscopy (SPM) to build a tip-assisted THz wave emission microscope (TATEM), which is a valuable extension to current SPM science and technology. Illuminated by a femtosecond laser, the biased SPM tip forms a THz wave source inside the sample beneath the tip. The source size is proportional to the apex size of the tip so that in theory the best resolution is comparable to that of a scanning probe microscope. The system may provide a useful tool for investigating the local properties of nano-size substances. Nano-structure or electronics device may also be studied by this system.

Yuan, Tao

263

Active Learning: A Small Group Histology Laboratory Exercise in a Whole Class Setting Utilizing Virtual Slides and Peer Education  

ERIC Educational Resources Information Center

Histology laboratory instruction is moving away from the sole use of the traditional combination of light microscopes and glass slides in favor of virtual microscopy and virtual slides. At the same time, medical curricula are changing so as to reduce scheduled time for basic science instruction as well as focusing on student-centered learning…

Bloodgood, Robert A.

2012-01-01

264

Mars Under the Microscope  

NASA Technical Reports Server (NTRS)

This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured by the rover's microscopic imager on the 10th day, or sol, of its mission. Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or 'seed.'

The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

2004-01-01

265

Traditional microscopy instruction versus process-oriented virtual microscopy instruction: a naturalistic experiment with control group  

PubMed Central

Background Virtual microscopy is being introduced in medical education as an approach for learning how to interpret information in microscopic specimens. It is, however, far from evident how to incorporate its use into existing teaching practice. The aim of the study was to explore the consequences of introducing virtual microscopy tasks into an undergraduate pathology course in an attempt to render the instruction more process-oriented. The research questions were: 1) How is virtual microscopy perceived by students? 2) Does work on virtual microscopy tasks contribute to improvement in performance in microscopic pathology in comparison with attending assistant-led demonstrations only? Method During a one-week period, an experimental group completed three sets of virtual microscopy homework assignments in addition to attending demonstrations. A control group attended the demonstrations only. Performance in microscopic pathology was measured by a pre-test and a post-test. Student perceptions of regular instruction and virtual microscopy were collected one month later by administering the Inventory of Intrinsic Motivation and open-ended questions. Results The students voiced an appreciation for virtual microscopy for the purposes of the course and for self-study. As for learning gains, the results indicated that learning was speeded up in a subgroup of students consisting of conscientious high achievers. Conclusions The enriched instruction model may be suited as such for elective courses following the basic course. However, the instructional model needs further development to be suited for basic courses.

2011-01-01

266

Varieties of virtualization  

NASA Technical Reports Server (NTRS)

Natural environments have a content, i.e., the objects in them; a geometry, i.e., a pattern of rules for positioning and displacing the objects; and a dynamics, i.e., a system of rules describing the effects of forces acting on the objects. Human interaction with most common natural environments has been optimized by centuries of evolution. Virtual environments created through the human-computer interface similarly have a content, geometry, and dynamics, but the arbitrary character of the computer simulation creating them does not insure that human interaction with these virtual environments will be natural. The interaction, indeed, could be supernatural but it also could be impossible. An important determinant of the comprehensibility of a virtual environment is the correspondence between the environmental frames of reference and those associated with the control of environmental objects. The effects of rotation and displacement of control frames of reference with respect to corresponding environmental references differ depending upon whether perceptual judgement or manual tracking performance is measured. The perceptual effects of frame of reference displacement may be analyzed in terms of distortions in the process of virtualizing the synthetic environment space. The effects of frame of reference displacement and rotation have been studied by asking subjects to estimate exocentric direction in a virtual space.

Ellis, Stephen R.

1991-01-01

267

The Virtual Slice Setup  

PubMed Central

In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables which in any case are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out – alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 minutes/hour on a laptop.

Lytton, William W; Neymotin, Samuel A; Hines, Michael L

2008-01-01

268

Five years of experience teaching pathology to dental students using the WebMicroscope  

PubMed Central

Background We describe development and evaluation of the user-friendly web based virtual microscopy - WebMicroscope for teaching and learning dental students basic and oral pathology. Traditional students microscopes were replaced by computer workstations. Methods The transition of the basic and oral pathology courses from light to virtual microscopy has been completed gradually over a five-year period. A pilot study was conducted in academic year 2005/2006 to estimate the feasibility of integrating virtual microscopy into a traditional light microscopy-based pathology course. The entire training set of glass slides was subsequently converted to virtual slides and placed on the WebMicroscope server. Giving access to fully digitized slides on the web with a browser and a viewer plug-in, the computer has become a perfect companion of the student. Results The study material consists now of over 400 fully digitized slides which covering 15 entities in basic and systemic pathology and 15 entities in oral pathology. Digitized slides are linked with still macro- and microscopic images, organized with clinical information into virtual cases and supplemented with text files, syllabus, PowerPoint presentations and animations on the web, serving additionally as material for individual studies. After their examinations, the students rated the use of the software, quality of the images, the ease of handling the images, and the effective use of virtual slides during the laboratory practicals. Responses were evaluated on a standardized scale. Because of the positive opinions and support from the students, the satisfaction surveys had shown a progressive improvement over the past 5 years. The WebMicroscope as a didactic tool for laboratory practicals was rated over 8 on a 1-10 scale for basic and systemic pathology and 9/10 for oral pathology especially as various students’ suggestions were implemented. Overall, the quality of the images was rated as very good. Conclusions An overwhelming majority of our students regarded a possibility of using virtual slides at their convenience as highly desirable. Our students and faculty consider the use of the virtual microscope for the study of basic as well as oral pathology as a significant improvement over the light microscope.

2011-01-01

269

Virtual data in CMS production  

SciTech Connect

Initial applications of the GriPhyN Chimera Virtual Data System have been performed within the context of CMS Production of Monte Carlo Simulated Data. The GriPhyN Chimera system consists of four primary components: (1) a Virtual Data Language, which is used to describe virtual data products, (2) a Virtual Data Catalog, which is used to store virtual data entries, (3) an Abstract Planner, which resolves all dependencies of a particular virtual data product and forms a location and existence independent plan, (4) a Concrete Planner, which maps an abstract, logical plan onto concrete, physical grid resources accounting for staging in/out files and publishing results to a replica location service. A CMS Workflow Planner, MCRunJob, is used to generate virtual data products using the Virtual Data Language. Subsequently, a prototype workflow manager, known as WorkRunner, is used to schedule the instantiation of virtual data products across a grid.

Arbree, A. et al.

2004-08-26

270

Femtosecond photoelectron point projection microscope  

SciTech Connect

By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

Quinonez, Erik; Handali, Jonathan; Barwick, Brett [Department of Physics, Trinity College, 300 Summit St., Hartford, Connecticut 06106 (United States)] [Department of Physics, Trinity College, 300 Summit St., Hartford, Connecticut 06106 (United States)

2013-10-15

271

Transmission electron microscope CCD camera  

DOEpatents

In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

Downing, Kenneth H. (Lafayette, CA)

1999-01-01

272

Review of the Microscopic Colitides  

Microsoft Academic Search

Microscopic colitis is a common cause of chronic diarrhea in predominantly older adults. Incidence rates of microscopic colitis\\u000a (including lymphocytic and collagenous colitis) have increased over time to levels comparable to other forms of inflammatory\\u000a bowel disease. The possibility of drug-induced microscopic colitis is an important consideration when evaluating these patients,\\u000a although this concept requires further investigation. There are few

Eugene F. Yen; Darrell S. Pardi

273

The National Virtual Observatory  

NASA Astrophysics Data System (ADS)

The National Virtual Observatory is a distributed computational facility that will provide access to the ``virtual sky''-the federation of astronomical data archives, object catalogs, and associated information services. The NVO's ``virtual telescope'' is a common framework for requesting, retrieving, and manipulating information from diverse, distributed resources. The NVO will make it possible to seamlessly integrate data from the new all-sky surveys, enabling cross-correlations between multi-Terabyte catalogs and providing transparent access to the underlying image or spectral data. Success requires high performance computational systems, high bandwidth network services, agreed upon standards for the exchange of metadata, and collaboration among astronomers, astronomical data and information service providers, information technology specialists, funding agencies, and industry. International cooperation at the onset will help to assure that the NVO simultaneously becomes a global facility. .

Hanisch, Robert J.

2001-06-01

274

Virtual Courseware: Earthquake  

NSDL National Science Digital Library

Virtual Earthquake is an interactive web-based program designed to introduce the concepts of how an earthquake epicenter is located and how the Richter magnitude of an earthquake is determined. Virtual Earthquake shows the recordings of an earthquake's seismic waves detected by instruments far away from the earthquake. The instrument recording the seismic waves is called a seismograph and the recording is a seismogram. The point of origin of an earthquake is called its focus and the point on the earth's surface directly above the focus is the epicenter. You are to locate the epicenter of an earthquake by making simple measurements on three seismograms that are generated by the Virtual Earthquake program. Additionally, you will be required to determine the Richter Magnitude of that quake from the same recordings. Richter Magnitude is an estimate of the amount of energy released during an earthquake.

Novak, Gary

2000-04-25

275

High efficiency virtual impactor  

DOEpatents

Environmental monitoring of atmospheric air is facilitated by a single stage virtual impactor for separating an inlet flow (Q/sub 0/) having particulate contaminants into a coarse particle flow (Q/sub 1/) and a fine particle flow (Q/sub 2/) to enable collection of such particles on different filters for separate analysis. An inlet particle acceleration nozzle and coarse particle collection probe member having a virtual impaction opening are aligned along a single axis and spaced apart to define a flow separation region at which the fine particle flow (Q/sub 2/) is drawn radially outward into a chamber while the coarse particle flow (Q/sub 1/) enters the virtual impaction opening.

Loo, B.W.

1980-03-27

276

Upper mantle structure beneath eastern Siberia: Evidence from gravity modeling and mantle petrology  

Microsoft Academic Search

The spatial distribution of large-scale lithospheric domains and the boundaries between them may control the emplacement of large ore bodies, and as such, regional mapping of the lithosphere is relevant to mineral exploration. In this study we combine potential-field geophysical data and mantle petrology to map major lithospheric structures on the eastern part of the Siberian platform. The platform consists

Yvette H. Poudjom Djomani; Suzanne Y. O'Reilly; W. L. Griffin; L. M. Natapov; Y. Erinchek; J. Hronsky

2003-01-01

277

Petrologic Constraints on the Pressure, Temperature, Time and Composition of the Martian Interior.  

National Technical Information Service (NTIS)

Petrologic analysis of surface samples has been used to deduce pressure and temperature conditions existing in the crust and upper mantle at specific times in the Earth's history, as well as to estimate the chemical and mineralogical composition of the cr...

J. R. Holloway

1988-01-01

278

Recently formed elastic anisotropy and petrological models for the continental subcrustal lithosphere in southern Germany  

Microsoft Academic Search

This paper advances new evidence for elastic anisotropy in the continental subcrustal lithosphere in southern Germany. The range of petrological models compatible with the observed azimuthal variation of seismic P-wave velocity is explored. The azimuthal distribution of amplitudes of mantle phases and the observed increase of P velocity with depth both indicate a continuation of anisotropy with depth together with

Karl Fuchs

1983-01-01

279

Petrological characteristics and volatile content of magma from the 2000 eruption of Miyakejima Volcano, Japan  

Microsoft Academic Search

Among the series of eruptions at Miyakejima volcano in 2000, the largest summit explosion occurred on 18 August 2000. During this explosion, vesiculated bombs and lapilli having cauliflower-like shapes were ejected as essential products. Petrological observation and chemical analyses of the essential ejecta and melt inclusions were carried out in order to investigate magma ascent and eruption processes. SEM images

Genji Saito; Kozo Uto; Kohei Kazahaya; Hiroshi Shinohara; Yoshihisa Kawanabe; Hisao Satoh

2005-01-01

280

? ? ? ?*,** ? ? ? ? ?** Investigation of the Petrologic Nature of the Moho toward the Mohole  

Microsoft Academic Search

This article reviews interpretations of the geological and petrological nature of the Moho, which is defined as a discontinuity in terms of Vp, with a view to preparing for the Mohole on the ocean floor in IODP. We strongly propose discarding non-seismic terms for the Moho, such as \\

Shoji ARAI; Natsue ABE

281

Origin of ocean island basalts: A new perspective from petrology, geochemistry, and mineral physics considerations  

Microsoft Academic Search

Consideration of petrology, geochemistry, and mineral physics suggests that ancient subducted oceanic crusts cannot be the source materials supplying ocean island basalts (OIB). Melting of oceanic crusts cannot produce high-magnesian OIB lavas. Ancient oceanic crusts (>1 Ga) are isotopically too depleted to meet the required values of most OIB. Subducted oceanic crusts that have passed through subduction zone dehydration are

Yaoling Niu; Michael J. O'Hara

2003-01-01

282

Hardgrove grindability index and petrology used as an enhanced predictor of coal feed rate  

SciTech Connect

An improved predictor of coal pulverization behavior and coal feed rate is under development at the CAER based upon the interaction between Hardgrove Grindability Index (HGI) and coal petrology. With educated attention, this interaction may be a useful tool to enhance coal feed rates if cautiously extended to the mining environment where blends of coal lithotypes are produced.

Hower, J.C. (Univ. of Kentucky, KY (US))

1990-01-01

283

Petrology and chemistry of the Picritic Shergottite North West Africa 1068 (NWA 1068)  

Microsoft Academic Search

We report on the petrology and chemistry of North West Africa 1068 (NWA 1068), a shergottite recently recovered in Morocco. This meteorite has a total known mass of about 577 g and comprises 23 fragments. The largest fragment is a greenish-brown rock devoid of fusion crust. It displays a porphyritic texture consisting of a fine-grained groundmass and olivine grains. Excluding

J. A Barrat; A. Jambon; M. Bohn; P. h Gillet; V. Sautter; C. Gopel; M. Lesourd; F. Keller

2002-01-01

284

Petrology of Cretaceous Coals from Northern Alaska. Final Technical Report, September 1, 1981-February 28, 1983.  

National Technical Information Service (NTIS)

Alaska has large coal resources and a major portion of these lie on the Arctic North Slope. A project was initiated with the support of the US Department of Energy to conduct a reconnaissance petrological survey of the Northern Alaska field, in order to g...

P. D. Rao J. E. Smith

1983-01-01

285

Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of the Martian Meteorites  

NASA Technical Reports Server (NTRS)

This volume contains abstracts that have been accepted for presentation at the conference on Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of Martian Meteorites, September 11-12, 2002, in Houston, Texas. Administration and publications support for this meeting were provided by the staff of the Publications and Program Services Department at the Lunar and Planetary Institute.

2002-01-01

286

Three-dimensional reconstruction and analysis of gastric malignancies by electronic slides of consecutive sections and virtual microscopy  

Microsoft Academic Search

Objective: The application of an electronic slide and a software simulated virtual microscope can contribute to a more efficient, convenient histological analysis. These techniques would also support the automation of histological analysis and three dimensional reconstruction of histological objects. Study Design: A fully computer controlled microscope (Axioplan 2 MOT), video camera (Grundig FAC 830) and an Intel Pentium II based

Bela Molnar; Kornel Papik; Attila Tagscherer; Gabor Csendes; Sebestyen V. Varga; Zsolt Tulassay; Rainer Schaefer; Walt Mahoney

1999-01-01

287

Virtual Amateur Astronomer  

NSDL National Science Digital Library

The Virtual Amateur Astronomer is an archive of high-quality images of all varieties of astronomical objects. The images, hosted on the Virtual Amateur Astronomer web site and linked from other web pages, include high- and low-resolution versions (where available), brief descriptions, and links to additional information. They are organized by subject: the solar system, Messier objects, the Milky Way and universe, and a selection of miscellaneous images. There is also a "best of" category, links to other web sites with astronomical imagery, and a selection of images capturing the amateur experience, captured through small telescopes.

288

A VIRTUAL OPERATING SYSTEM  

SciTech Connect

Significant progress toward disentangling computing environments from their under lying operating systern has been made. An approach is presented that achieves inter-system uniformity at all three levels of user interface - virtual machine, utilities, and command language. Under specifiable conditions, complete uniformity is achievable without disturbing the underlying operating system. The approach permits accurate computation of the cost to move both people and software to a new system. The cost of moving people is zero, and the cost of moving software is equal to the cost of implementing a virtual machine. Efficiency is achieved through optimization of the primitive functions.

Hall, Dennis E.; Scherrer, Deborah K.; Sventek, Joseph S.

1980-05-01

289

Virtual-Geology.Info  

NSDL National Science Digital Library

At virtual-geology.info, Roger Suthren, a professor at Oxford Brookes University, offers educational materials on geologic phenomena throughout the world. Users can take virtual field trips to study the geology of Scotland, Alaska, and France. In the Regional Geology link, visitors can view wonderful pictures of the volcanoes of Germany, Italy, France, and Greece. Educators can find images of sediments and sedimentary rocks which can be used in a variety of classroom exercises. The website supplies descriptions and additional educational links about sedimentology and environmental geology.

290

Petrology of the spinel peridotite xenoliths from petit spot volcanoes  

NASA Astrophysics Data System (ADS)

Petit spot is a new type of volcanism recently discovered in the NW Pacific and in some other oceanic regions [Hirano et al., 2006; 2008]. The eruption ages of the volcanoes are estimated younger than 10 Ma, whereas the Pacific Plate of the area was formed in the Early Cretaceous (~130 Ma). The volcanoes erupted strong to moderate alkaline and highly vesicular basalt. The locations of the volcanic fields, when they were active, were estimated away from any spreading centers, hotspots and even island arcs [Hirano et al., 2006]. The alignment and the size of the knolls imply that this volcanic field is a monogenetic volcanic cluster, which are often observed in the intra-continental plate. In order to understand the petit spot volcanism, we are taking trans-disciplinary surveys using JAMSTEC R/V KAIREI and YOKOSUKA and shore-based research suggest that there are a lot of small knolls assumed young volcanoes [Abe et al., 2005; 2008]. As many monogenetic alkaline-basalt volcanoes, some of petit spot volcanoes include deep-seated rocks xenoliths. They are fragments of dolerite, micro-gabbro, gabbro, lherzolite, dunite, wehrlite, pyroxenite and harzburgite [Abe et al., 2006]. The major- and trace-element chemistry of the mafic xenoliths shows normal MORB composition [Machida per. Com.], and the major mineral chemistry of the ultramafic xenoliths has a variation within the abyssal peridotite and have chromian spinel. The Noble gas chemistry suggests that they are the fragments of the old Pacific plate [Yamamoto et al., 2009; Shimizu et al., per. com.]. The clinopyroxene in one of the ultramafic xenoliths has LREE-depleted trace element patterns which is similar to that in the abyssal peridotite from slow spreading ridges. The other samples have LREE-enriched patterns, and the one lherzolite shows highly HREE-depleted patterns which is same as the pattern of clinopyroxene in garnet peridotite in Kimberlites [Abe et al., 2006]. This suggests that the lherzolite sample is originated from the depth of the boundary between spinel- and garnet-stability fields in the deep oceanic lithosphere. As a result of the study, those ultramafic xenoliths were seated in the different depth of the oceanic lithosphere. It is noteworthy that no serpentinite or highly altered maficc rocks discovered in the petit spot volcanic field. The deep-seated rock xenoliths and its host alkaline basalt provide us much information about the geochemical, petrological and physical structure and the thermal state of the old oceanic plate [Abe et al., 2006; Yamamoto et al., 2009; Harigane et al., 2011].

Abe, N.; Tamura, A.; Morishita, T.; Hirano, N.; Arai, S.

2011-12-01

291

Petrology of enstatite chondrites and anomalous enstatite achondrites  

NASA Astrophysics Data System (ADS)

Chondrites are meteorites that represent unmelted portions of asteroids. The enstatite chondrites are one class of chondrites. They consist of reduced mineral assemblages that formed under low oxygen fugacity in the solar nebula, prior to accretion into asteroids. There are two groups of enstatite chondrites---EH and EL. I studied EL3 meteorites, which are understood to be unmetamorphosed and thus to only preserve primitive nebular products. I show in a petrographic study that the EL3s are in fact melt--breccias in which impact-melting produced new mineral assemblages and textures in portions of the host chondrites, after accretion. I document meta- land sulfide assemblages that are intergrown with silicate minerals (which are often euhedral), and occur outside chondrules; these assemblages probably represent impact-melting products, and are different from those in EH3 chondrites that probably represent nebular products. In situ siderophile trace element compositions of the metal in EL3s, obtained by laser ablation inductively coupled plasma mass spectrometry, are consistent with an impact-melting hypothesis. The trace element concentrations show no clear volatility trend, and are thus probably not the result of volatile-driven petrogenetic processes that operated in the solar nebula. Trace element modeling suggests that the character of the trace element patterns together with deviations from the mean bulk EL metal pattern is consistent with metal that crystallized in a coexisting liquid-solid metal system in which dissolved carbon influenced element partitioning. I also conducted a petrographic and mineral-chemistry study of several anomalous enstatite meteorites. These have igneous textures, but unfractionated mineralogy similar to unmelted chondrites. I show that with the exception of one, the meteorites are related to each other, and probably formed by crystallization from an impact melt instead of metamorphism through the decay of short lived radionuclides. The broad importance of these studies lies in documenting the petrology of extraterrestrial materials that reveal the geological history of the young solar system prior to the existence of planets. Furthermore, they serve to identify which mineral assemblages record nebular processes and which record processes on asteroids, so that future studies may select the correct material to address particular questions.

van Niekerk, Deon

2012-01-01

292

Aragats stratovolcano in Armenia - volcano-stratigraphy and petrology  

NASA Astrophysics Data System (ADS)

In this contribution we discuss the geological structure and volcano-stratigraphy of the Quaternary Aragats stratovolcano in Armenia based on recent age determinations as well as petrological and geochemical features of magma generation processes specific for collision zones. Armenia is situated in the NE part of the Anatolian-Armenian-Iranian plateau, an intensely deformed segment of the Alpine-Himalayan belt. The complex geological structure of the region is represented by a mosaic of tectonic blocks comprising fragments of volcanic arcs, continental crust and exhumed oceanic crust. Collision of the Arabian plate with the Eurasian margin in early Miocene resulted in orogenic uplift associated with intense volcanism. Aragats (4090m) is one the largest volcanoes in the entire region and produced central vent (inc. Plinian VEI>4) and monogenetic type flank eruptions and periphery plateaus within a total area greater than 5000 km2, known as Aragats volcanic province (AVP). The Aragats volcanic province (AVP) comprises the composite cone of Aragats volcano, the peak of which is built on a summit plateau, ~45 km in diameter shield structure with dozens of flank vents, scattered monogenetic cinder cones on the adjacent volcanic plateaus as well as the neighboring stratovolcano Arailer. New K-Ar and 40Ar/39Ar age determinations of groundmass and separated plagioclase samples indicate that volcanism at AVP began ~2.5 Ma, while most recent volcanic activity is 0.49 Ma for Plinian eruption of dacites from Irind flank vent and basaltic trachyandesite lava flows from Tirinkatar (0.48-0.61 Ma), Kakavasar, (0.52-0.54 Ma) and Ashtarak (0.58 Ma) monogenetic flank centers, as well as trachyandesites of Jrbazhan volcano on the summit plateau of Aragats (0.52 Ma). Based on bulk rock geochemical data (major, minor and low abundance trace elements, Sr and Nd isotopes) and mineral chemistry, we conclude that volcanic rocks of AVP are largely recording a complex mixing between deep asthenospheric mantle and remnants of subduction-modified and metasomatically enriched mantle sources, followed by fractionation in large magma chamber(s). Mineral-melt equilibria studies reveal dry (<1%H2O) and very hot source, fluid inclusions study reveal pronounced enrichment with CO2 over H2O in fluid phase. Noteworthy are high eruption temperatures compared to global volcanic arcs, explaining the very long (up to 25 km) and thick (>200m) trachydacitic lava flows.

Meliksetian, Khachatur; Savov, Ivan; Connor, Charles; Halama, Ralf; Jrbashyan, Ruben; Navasardyan, Gevorg; Ghukasyan, Yura; Gevorgyan, Hripsime; Manucharyan, Davit; Ishizuka, Osamu; Quidelleur, Xavier; Germa, Aurélie

2014-05-01

293

Organic petrological and organic geochemical characterisation of the Tertiary coal-bearing sequence of Batu Arang, Selangor, Malaysia  

NASA Astrophysics Data System (ADS)

The Tertiary coal-bearing sequence at Batu Arang in Selangor, Peninsular Malaysia consists of a sandstone-coal-oil shale facies assemblage. A detailed organic petrological and organic geochemical study was carried out on several organic-rich sediments from this sequence. The oil shales are dominated by Botryococcus-derived telalginite and Pediastrum-derived lamalginite. The coals, hypautochthonous in origin, are mainly duroclarite-type, although other minor microlithotypes also occur. Alginite is not observed in the coals, but other liptinitic constituents are very common, particularly thin-walled cutinite and sporinite. The oil shales and the coals are thermally immature. This immaturity has a considerable influence on the biomarker distributions, particularly so on the triterpanes which are dominated by C 31?? 22R and C 30?? compounds. Interestingly, for Tertiary aged sediments of continental origin, the diagnostic biomarker compounds such as 18 ?(H)-oleanane and bicadinanes, normally linked to the higher land plant group of angiosperms, are not observed in the samples analysed. Tricyclic terpanes occur only in very low relative abundance or are virtually absent. A clear distinction, however, in the biomarker distributions of the shales and the coals/carbargilite can be made based upon the distribution of C 27-C 29 regular steranes: the shales, with a source input being predominantly planktonic algae, are dominated by 5 ?(H),14 ?(H),17 ?(H) 20R cholestane, while the coals/carbargilites, with a source input consisting mainly of higher plant material, are dominated by 5 ?(H),14 ?(H),17 ?(H) 20R ethyl cholestane. The depositional environment of the Batu Arang coal-bearing sequence is interpreted as varying from an alluvial flood plain peat-swamp to fluvio-lacustrine depositional setting.

Wan Hasiah, Abdullah; Abolins, Peter

1998-08-01

294

Pearls found on the way to the ideal interface for scanned-probe microscopes  

Microsoft Academic Search

Since 1991, our team of computer scientists, chemists and physi- cists have worked together to develop an advanced, virtual- environment interface to scanned-probe microscopes. The inter- face has provided insights and useful capabilities well beyond those of the traditional interface. This paper lists the particular visualization and control techniques that have enabled actual scientific discovery, including specific examples of insight

Russell M. II taylor; Jun Chen; Shoji Okimoto; Noel Llopis-Artime; Vernon L. Chi; Frederick P. Brooks Jr.; Mike Falvo; Scott Paulson; Pichet Thiansathaporn; David Glick; Sean Washburn; Richard Superfine

1997-01-01

295

High Assurance Virtualization Engine (HAVEN).  

National Technical Information Service (NTIS)

This report describes the research results of the High Assurance Virtualization ENgine. HAVEN is an FPGA-based virtualization technology that implements much of the traditional hypervisor functionality in FPGAs instead of in software. There are two main r...

N. Memon P. Mathur R. Karri V. Padman

2009-01-01

296

Integrated real and virtual prototyping  

Microsoft Academic Search

A modelling environment for the geometrical, topological and functional specification of mechatronic systems is presented. The close coupling of real model components and their virtual counterparts allows a synchronous construction of real and virtual prototypes and their evaluation

F. Wilhelm Bruns

1998-01-01

297

The macroscopic scanning force `microscope'  

Microsoft Academic Search

A homemade, macroscopic version of the scanning force microscope is described. It consists of a cantilever under the influence of external forces, which mimic the tip-sample interactions. The use of this piece of equipment is twofold. First, it serves as a direct way to understand the parts and functions of the scanning force microscope, and thus it is effectively used

Fredy R. Zypman; Claudio Guerra-Vela

2001-01-01

298

Microscopic models of hydrodynamic behavior  

Microsoft Academic Search

We review recent developments in the rigorous derivation of hydrodynamic-type macroscopic equations from simple microscopic models: continuous time stochastic cellular automata. The deterministic evolution of hydrodynamic variables emerges as the “law of large numbers,” which holds with probability one in the limit in which the ratio of the microscopic to the macroscopic spatial and temporal scales go to zero. We

Joel L. Lebowitz; Errico Presutti; Herbert Spohn

1988-01-01

299

A Simple Scanning Electron Microscope  

Microsoft Academic Search

A simple scanning microscope has been built which uses a field emission electron gun alone, without the aid of auxiliary lenses. The design and operation of the microscope are described and the calculated performance is compared with experiment. Resolution of 100 Å has been obtained and is shown in transmission electron micrographs. The probe current is of the order of

A. V. Crewe; M. Isaacson; D. Johnson

1969-01-01

300

Optical Analysis of Microscope Images  

Microsoft Academic Search

Microscope images were analyzed with coherent and incoherent light using analog optical techniques. These techniques were found to be useful for analyzing large numbers of nonsymbolic, statistical microscope images. In the first part phase coherent transparencies having 20-100 human multiple myeloma nuclei were simultaneously photographed at 100 power magnification using high resolution holographic film developed to high contrast. An optical

Jonathan R. Biles

1986-01-01

301

A Virtual, Shoestring Vacation  

NSDL National Science Digital Library

If there is a discrepancy between the scope of your imagination and the depth of your bank account, this may be the ideal summer to stretch your horizons by diving into a good book. You can take a virtual vacation to almost any place or time by reading. Y

Texley, Juliana

2009-07-01

302

Virtual Tide Pool  

NSDL National Science Digital Library

Virtual Tide Pool features a three dimensional view of a tide pool during both low and high tides. Students can see animals that live under, above, and at the waters surface. This site offers the ability to pan the tide pool for a 360 degree view, with zoom options, and gives descriptions of the animals found during both low and high tides.

Science NetLinks (PBS;)

2003-04-29

303

Rethinking Virtual Reference  

ERIC Educational Resources Information Center

Virtual reference services seem a natural extension of libraries digital collections and the emphasis on access to the library anytime, anywhere. If patrons use the library from home, it makes sense to provide them with person-to-person online reference. The Library of Congress (LC), OCLC, and several large library systems have developed and…

Tenopir, Carol

2004-01-01

304

Virtual machine performance benchmarking.  

PubMed

The attractions of virtual computing are many: reduced costs, reduced resources and simplified maintenance. Any one of these would be compelling for a medical imaging professional attempting to support a complex practice on limited resources in an era of ever tightened reimbursement. In particular, the ability to run multiple operating systems optimized for different tasks (computational image processing on Linux versus office tasks on Microsoft operating systems) on a single physical machine is compelling. However, there are also potential drawbacks. High performance requirements need to be carefully considered if they are to be executed in an environment where the running software has to execute through multiple layers of device drivers before reaching the real disk or network interface. Our lab has attempted to gain insight into the impact of virtualization on performance by benchmarking the following metrics on both physical and virtual platforms: local memory and disk bandwidth, network bandwidth, and integer and floating point performance. The virtual performance metrics are compared to baseline performance on "bare metal." The results are complex, and indeed somewhat surprising. PMID:21207096

Langer, Steve G; French, Todd

2011-10-01

305

Virtual keyboard layout optimization  

Microsoft Academic Search

The use of virtual keyboards is becoming ubiquitous with increasing use in mobile devices and touch-screens. Till now the research has mainly focused on developing layouts which support high typing speed, but the error aspect has been largely ignored. This research aims at developing a novel error model which relates accuracy with a given layout using the distance between keys.

Siddharth Jain; Samit Bhattacharya

2010-01-01

306

Physics Virtual Bookshelf  

NSDL National Science Digital Library

The Physics Virtual Bookshelf is a collection of documents written by professors as class notes or physics education research. This collection includes content on classical physics, computational physics, data analysis, modern physics, relativity, quantum mechanics, and pedagogy. The collection is organized by topic and easily browsed.

Bailey, David; Key, Anthony W.; Logan, Robert K.; Drummond, James R.; Sinervo, Pekka K.; Orr, Robert S.

2005-10-24

307

Fossil Halls: Virtual Tours  

NSDL National Science Digital Library

Part of a larger online look at the Museum's famed Fossil Halls, this Web site has an overview of the halls' many highlights and four QuickTime virtual tours:Hall of Saurischian Dinosaurs, Hall of Ornithischian Dinosaurs, Hall of Primitive Mammals, and Hall of Advanced Mammals.

308

Virtual First Impressions  

ERIC Educational Resources Information Center

Frequently, a nurse's first and only contact with a graduate school, legislator, public health official, professional organization, or school nursing colleague is made through e-mail. The format, the content, and the appearance of the e-mail create a virtual first impression. Nurses can manage their image and the image of the profession by…

Bergren, Martha Dewey

2005-01-01

309

Virtual Bead Loom  

NSDL National Science Digital Library

This site uses the example of Native American beadwork to demonstrate mathematical concepts (specifically, Cartesian coordinates). The materials include an interactive virtual beadloom with which students can create their own beadwork design. The interdisciplinary lesson may be used in conjunction with instruction on Native American culture and traditions.

2010-12-29

310

Growing Virtual Communities  

ERIC Educational Resources Information Center

As online collaborative technologies become easier to use, an increasing range of "virtual communities" are being established, often for educational purposes. This report stresses that an efficient technology is only part of the process underlying a successful online community. It considers the social process on which an online learning community…

Garber, Debbie

2004-01-01

311

Virtual private networks  

Microsoft Academic Search

A virtual private network (VPN) can help resolve many of the issues associated with today's private networks. A VPN facilitates an agile IT infrastructure. Global VPNs enable connectivity to all locations anywhere in the world at a fraction of the cost of dedicated links. VPN services enable remote access to the intranet at significantly lower cost, thus enabling support for

R. Venkateswaran

2001-01-01

312

Diffy Virtual Manipulative  

NSDL National Science Digital Library

Diffy is a virtual manipulative that allows students to practice their subtraction facts with whole numbers, integers, fractions, decimals, or money. It is a puzzle of sorts with four black numbers placed at the corners of a black square. The first goal is to fill in the four blanks in the blue circles in the middle of each side of the black square.

University, Utah S.

2011-06-28

313

Virtual Libraries: Service Realities.  

ERIC Educational Resources Information Center

This paper discusses client service issues to be considered when transitioning to a virtual library situation. Themes related to the transitional nature of society in the knowledge era are presented, including: paradox and a contradictory nature; blurring of boundaries; networks, systems, and holistic thinking; process/not product, becoming/not…

Novak, Jan

314

Virtual Knee Surgery  

NSDL National Science Digital Library

In this online activity, learners assist in performing a virtual total knee replacement surgery. There is a great deal of information about this procedure specifically as well as general surgical information, along with questions the learner must answer (using information given onscreen) before the surgery can proceed.

Edheads; Cosi

2007-01-01

315

Energy Savers Virtual Home  

NSDL National Science Digital Library

This web-based computer simulation allows the participant to calculate energy savings in various types of virtual residential dwellings by making changes in the appliances, light bulbs, insulation, energy sources, etc. that are used. This is a totally interactive simulation that would be suitable for junior high school through college classes. This simulation also contains links where students can access research information.

2007-09-28

316

Physics Virtual Bookshelf  

NSDL National Science Digital Library

The Physics Virtual Bookshelf is a collection of documents written by professors as class notes or physics education research. This collection includes content on classical physics, computational physics, data analysis, modern physics, relativity, quantum mechanics, and pedagogy. The collection is organized by topic and easily browsed. The site is viewable as a standard Web page (default) or in Adobe Flash format.

Harrison, David M.

2009-06-18

317

3D virtual colonoscopy  

Microsoft Academic Search

The authors present here a method called 3D virtual colonoscopy, which is an alternative method to existing procedures of imaging the mucosal surface of the colon. Using 3D reconstruction of helical CT data and volume visualization techniques, the authors generate images of the inner surface of the colon as if the viewer's eyes were inside the colon. They also create

Lichan Hong; Arie Kaufman; Yi-Chih Wei; Ajay Viswambharan; M. Wax; Zhengrong Liangs

1995-01-01

318

Virtual-Channel Flow Control  

Microsoft Academic Search

Abstract Network throughput,can be increased by dividing the buffer storage associated with each network channel into several virtual channels [DalSei]. Each physical channel is associated with several small queues, virtual channels, rather than a single deep queue. The virtual channels associated with one physical channel,are allocated in- dependently,but compete,with each other for physical bandwidth.,Virtual channels,decouple,buffer resources from transmission resources. This

William J. Dally

1992-01-01

319

Virtual Sensor Test Instrumentation  

NASA Technical Reports Server (NTRS)

Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of functions. The sensor data is processed in a distributed fashion across the network, providing a large pool of resources in real time to meet stringent latency requirements.

Wang, Roy

2011-01-01

320

Virtualization of the PDP-11/50.  

National Technical Information Service (NTIS)

This thesis presents an overview of the virtual machine concept discussing different properties of the virtual machine and the basic environment necessary to virtualize an existing computer. Concurrent with this study, feasibility of virtualizing the PDP-...

J. C. Winther D. M. Kruse

1975-01-01

321

Performance Optimization of Virtual Keyboards  

Microsoft Academic Search

Text entry has been a bottleneck of nontraditional computing devices. One of the promising methods is the virtual keyboard for touch screens. Correcting previous estimates on virtual keyboard efficiency in the literature, we estimated the potential performance of the existing QWERTY, FITALY, and OPTI de- signs of virtual keyboards to be in the neighborhood of 28, 36, and 38 words

Shumin Zhai; Michael Hunter; Barton A. Smith

2002-01-01

322

World Reaction to Virtual Space  

NASA Technical Reports Server (NTRS)

DRaW Computing developed virtual reality software for the International Space Station. Open Worlds, as the software has been named, can be made to support Java scripting and virtual reality hardware devices. Open Worlds permits the use of VRML script nodes to add virtual reality capabilities to the user's applications.

1999-01-01

323

Explaining packet delays under virtualization  

Microsoft Academic Search

This paper performs controlled experiments with two popular virtualization techniques, Linux-VServer and Xen, to examine the effects of virtualization on packet sending and receiving delays. Using a controlled setting allows us to independently investigate the influence on delay measurements when competing virtual machines (VMs) perform tasks that consume CPU, memory, I\\/O, hard disk, and network bandwidth. Our results indicate that

Jon Whiteaker; Fabian Schneider; Renata Teixeira

2011-01-01

324

Leading Virtual Teams: Three Cases  

ERIC Educational Resources Information Center

This study investigated virtual team members' and leaders' perceptions of the role of the leader, and hindering and helping forces within virtual teams and their host organizations for developing leaders of such teams. It addresses the expressed need of virtual team leaders for the field of HRD to guide leadership development for this emerging…

Johnson, James R.; Jeris, Laurel

2004-01-01

325

GENERATING VIRTUAL ARCHITECTURE WITH STYLE  

Microsoft Academic Search

Virtual architecture is a networked spatial environment designed using the metaphor of physical architecture 1 , from which virtual architecture inherits many visual and spatial characteristics. However, in order to further explore its potential, virtual architecture need to go beyond its physical metaphor to develop its own theories and styles. One important step of this process is to establish a

Ning Gu; Mary Lou Maher

326

Virtual Worlds in Computing Education  

ERIC Educational Resources Information Center

This article reports on the use of a virtual world ("Second Life") in computing education, and identifies the precursors of current virtual world systems. The article reviews the potential for virtual worlds as tools in computing education. It describes two areas where "Second Life" has been used in computing education: as a development…

Crellin, Jonathan; Duke-Williams, Emma; Chandler, Jane; Collinson, Timothy

2009-01-01

327

Virtual Camera Planning: A Survey  

Microsoft Academic Search

Modelling, animation and rendering has dominated research computer graphics yielding increasingly rich and realistic virtual worlds. The complexity, richness and quality of the virtual worlds are viewed through a single media that is a virtual camera. In order to properly convey information, whether related to the characters in a scene, the aesthetics of the composition or the emotional impact of

Marc Christie; Rumesh Machap; Jean-marie Normand; Patrick Olivier; Jonathan Pickering

2005-01-01

328

Final Report of Special Geological, Geochemical, and Petrological Studies of the Devonian Shales in the Appalachian Basin.  

National Technical Information Service (NTIS)

The purpose of this study was to describe the geology, petrology, lithology, sedimentology, and stratigraphy of the Devonian Shales in the Appalachian Basin in order to determine the potential for gas recovery. Specific study areas include Pine Mountain O...

P. E. Potter J. B. Maynard W. A. Pryor

1980-01-01

329

Microscopic study of the string breaking in QCD  

SciTech Connect

Theory of strong decays defines in addition to decay widths also the channel coupling and the mass shifts of the levels above the decay thresholds. In the standard decay models of the {sup 3}P{sub 0} type the decay vertex is taken to be a phenomenological constant {gamma} and such a choice leads to large mass shifts of all meson levels due to real and virtual decays, the latter giving a divergent contribution. Here we show that taking the microscopic details of decay vertex into account, one obtains new string width effect coefficient, which strongly suppresses virtual decay contribution. In addition for a realistic space structure of the decay vertex of highly excited states, the decay matrix elements appear to be strongly different from those, where the constant {gamma} is used. From our analysis also follows that so-called flattening potential can imitate the effects of intermediate decay channels.

Badalian, A. M., E-mail: badalian@itep.ru; Orlovsky, V. D., E-mail: orlovskii@itep.ru; Simonov, Yu. A., E-mail: simonov@itep.ru [Institute for Theoretical and Experimental Physics (Russian Federation)

2013-08-15

330

Virtual playgrounds : managing virtual resources in the Grid.  

SciTech Connect

Large grid deployments increasingly require abstractions and methods decoupling the work of resource providers and resource consumers to implement scalable management methods. We proposed the abstraction of a virtual workspace (VW) describing a virtual execution environment that can be made dynamically available to authorized grid clients by using well-defined protocols. Virtual workspaces provide resources in controllable ways that are independent of how a resource is consumed. A virtual playground may combine many such workspaces, as well as other aspects of virtual environments, such as networking and storage, to form virtual grids. In this paper, we report on the goals and progress of the virtual playground project and put in context the research to date.

Keahey, K.; Chase, J.; Foster, I.; Mathematics and Computer Science; Univ. of Chicago; Duke Univ.

2006-01-01

331

Petrological evolution of the metamorphic sole of Oman  

NASA Astrophysics Data System (ADS)

Obduction corresponds to one of plate tectonics oddities, whereby fragments of dense, oceanic lithosphere (ophiolites) are presumably 'thrust' on top of light continental ones. Though reported from most convergent belts, the emplacement of ophiolites is still poorly understood. The thin HT metamorphic soles (i.e., 800°C - 1 GPa, on average) frequently underlying such large ophiolite klippen may provide constraints on ophiolite emplacement. Metamorphic soles are indeed generally interpreted as oceanic shallow crustal material (basalts and sediments) heated against the warmer mantle at ~ 30 km depths during initiation of underthrusting and subduction initiation. Tracing the PT evolution of these soles can thus in principle shed light on early obduction stages. A number of major unknowns, however, still characterize metamorphic soles: (1) their enigmatic origin (i.e., underthrust cover of the future "lower" plate, or sheared, folded and reversed cover of the "upper" plate?) (2) emplacement mechanisms that allow these soles to become tectonically and rheologically welded to the base of the ophiolite mantle (especially in the first case), (3) the mismatch in P between metamorphic conditions (i.e., 30 km equilibrium depths) and preserved ophiolite thickness (~10-15 km). This contribution presents new data from various metamorphic sole locations across the Oman mountains, all dated at ~95 Ma, using pseudosections modelling (testing a range of appropriate solution models for amphiboles) on both pristine metamorphic remnants (including melts) and less frozen-in samples. PT constraints, reappraised from north to south-east, suggest subtle PT variations with a trend of deeper metamorphic equilibration towards the north, where PT conditions reach 850°C and 1-1.2 GPa. These thermobarometric data are complemented by multi-element geochemical constraints on the origin of metamorphic soles throughout Oman, which evidence very consistent E-MORB signatures and point to a protolith origin in a transitional oceanic domain located close to the continental margin. This result is in line with earlier findings (Ishikawara, 2005) and suggestions that these soles may derive from the Haybi complex (Searle and Cox, 1999). These data are compared to the available structural and petrological data on both the ophiolite proper and the metamorphic HP-LT subducted continental material beneath. We favour a scenario in which subduction initiates obliquely, in a transitional oceanic domain (close and to the north of Arabia), to a small and young marginal basin (c. 95 Ma; its spreading center is preserved in the south-east, near Maqsad). Limited calc-alkaline magmatic imprint (Lasail volcanism) and orthopyroxenite dykes on the south-western edge of the ophiolite could respectively correspond to limited arc magmatic inputs of the short-lived subduction and to the hydration-driven remelting of oceanic lithosphere. Our interpretation is finally set back in the frame of late Cretaceous Neotethyan geodynamics.

Agard, Philippe; Yamato, Philippe; Piccoli, Francesca; Benoît, Mathieu; Dubacq, Benoît; Guillot, Stéphane; Monié, Patrick; Chauvet, Alain; Ceuleneer, Georges; Chopin, Christian; Prigent, Cécile

2013-04-01

332

Petrological study of clinopyroxene phenocrysts from Mt. Etna volcano (Italy)  

NASA Astrophysics Data System (ADS)

A petrological study of clinopyroxene (Cpx) phenocrysts from both historical and recent eruptions of Mt. Etna volcano have carried out in order to investigate the processes occurring in the deepest portion of the feeding system and to constrain its chemical and physical variables. Four distinct textures were recognized: i) normal oscillatory-zoned; ii) reverse oscillatory-zoned; iii) sieve-textured cores and iv) dusty rim. Electron microprobe analysis revealed an almost constant Diopside-Augitic composition, with a slight enrichment in the enstatitic component in Cpx from more recent eruptions. Core to rim compositional profiles have been performed along the recognized textures. Normal oscillatory zoning is characterized by a sharp increase in FeO (?~2wt%) accompanied by a drop in Al2O3 in the outermost 30 ?m. On contrary, a drop in FeO, Al2O3 (?~2wt%) and a remarkable increase in MgO (up to 5wt%) at crystal rims marks reverse zoning. Similar compositional changes have been measured in dusty-textured rims, which are characterized by dissolution edges and crystal regrowth incorporating glass pockets and channels. No significant compositional variations have been observed across sieve-textured core. Trace element and REE concentrations have been measured by laser ablation mass spectrometry, evidencing enrichment in Sr, La, Zr and REE, together with a lowering of the La/Yb ratio (from ~7 to ~4), at rims in normal zoning crystals. On contrary, Cpx with reverse zoning and dusty rims always presents low Sr, La, Zr and REE contents towards crystal rims. Geothemobarometers of Putirka et al. (2003) and Putirka et al. (2004) have been applied to Cpx-melt pairs at crystal cores and rims after having checked the equilibrium conditions. Results evidence that Cpx cores start nucleating at 7.7 Kbar with the majority of them forming between 6.0 and 4.0 kbar and continue to crystallize until very shallow depth (<1 kbar). Normal oscillatory-zoned phenocrysts with Fe-rich rim form at pressure shallower than 4.0 kbar, while inverse zoning and dusty rims occur between 4 and 5 kbar. Cpx are able to record changes in the physical-chemical conditions of the magmatic system and two main distinct processes could be responsible for the observed texture. Fe-rich rim in normal oscillatory zoned crystal can be related to a decompression-induced crystallization, while reverse zoning and dusty rims can be produced by mixing with a more basic melt, occurring between 4-5 kbar, corresponding to about ~10 km of depth. Putirka et al., (2003). American Mineralogist, Vol. 88; pp.1542-1554; Putirka et al., (2008). Reviews in Mineralogy & Geochemistry, Vol. 69; pp. 61-120.

Giacomoni, Pier Paolo; Ferlito, Carmelo; Coltorti, Massimo; Bryce, Julie

2014-05-01

333

Mineralogy and Petrology of the Tagish Lake Meteorite: New Lithologies  

NASA Astrophysics Data System (ADS)

The Tagish Lake meteorite is an ungrouped type 2 carbonaceous chondrite. Two distinct lithologies were identified in the study by Zolensky et al. (2002), including a carbonate-poor lithology containing abundant phyllosilicates, Fe-Ni sulfides and magnetite with sparse, altered chondrules and CAIs; and a carbonate-rich lithology containing abundant Fe-Mg-Ca-Mn carbonates with rare magnetite and lacking in CAIs or chondrules. Lithological variations beyond these two lithologies are evident from casual inspection of the pristine samples of the meteorite (Herd and Herd 2007, LPSC). The origin of these variations is not known and forms the basis for the current study of the mineralogy and petrology of this unique meteorite. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been carried out on disaggregated fragments of two distinct lithologies; current work includes the study of polished mounts in which texture is preserved. SEM analysis was carried out at the Carnegie Institution of Washington and the University of Alberta. TEM analysis was carried out on microtomed samples at the Naval Research Laboratory with a 200 keV JEOL 2200FS TEM equipped with an EDS spectrometer and scanning-TEM (STEM) based bright- and high-angle annular-dark-field detectors. Two samples representative of the macroscopic lithological variation were selected. Sample 5b is a compact, coherent fragment with abundant chondrules. Sample 11i is an example of a dark, dusty lithology; fragments of this lithology are very friable and tend to shed a residue of very fine black dust. Our SEM observations show that sample 5b consists of altered chondrules in a matrix of Mg-Fe silicates, Fe-Ni sulfide and magnetite grains, the latter present as individual grains, framboids, or whiskers. The chondrules consist of Fe-Mg olivine and pyroxene, or Mg-rich olivine and enstatite. Sample 11i consists almost entirely of very fine-grained material (average grain size less than 5 microns), containing distinct Fe-Ni sulfides, individual magnetite grains, in some cases framboidal, and a compositionally diverse group of Fe-Mg silicates (presumably phyllosilicates). The largest distinct grain found thus far is a refractory forsterite grain, 80 microns in longest dimension. In addition, we have found elongate, football-shaped, Ca-rich (carbonate?) grains of unknown origin. TEM bright-field imaging of sample 11i reveals three types of silicate morphologies that we call ropy, rough and smooth based on their appearance. Their composition, as determined by EDS analysis, shows them to be consistent with Fe-Mg-rich phyllosilicates, although some are apparently amorphous. The difference in texture is likely the result of response of the material to microtome slicing due to differences in hardness. In contrast, sample 5b behaved differently during microtomy, as evidenced by the overall texture, which indicates that the lithology consists of minerals with higher hardness. High-resolution imaging shows that the sheet silicates have a wispy texture and are poorly ordered. Based on our preliminary SEM and TEM observations we conclude that the chondrule-bearing lithology represented by sample 5b is similar to the carbonate-poor lithology of Zolensky et al. (2002), whereas the dark, dusty lithology (sample 11i) has not been previously described. This lithology is notable for its lack of chondrules, fine-grained nature, and complement of amorphous material.

Blinova, A.; Herd, C. D.; Zega, T. J.; de Gregorio, B. T.

2009-05-01

334

Petrology, diagnosis, and sedimentology of oil reservoirs in Upper Cretaceous Shannon Sandstone Beds, Powder River basin, Wyoming  

SciTech Connect

This paper reports on a study of the petrology of the Shannon Sandstone Member that indicates diagenetic alterations of outcrop and near-surface sandstones cannot be used to predict the diagenesis of deeply buried sandstones. Textural relations show that oil migrated to reservoirs late in the postdepositional history of the Shannon. Petrologic and sedimentologic data suggest that an alternative depositional model (for example, a nearshore rather than mid-shelf setting) should be considered for the Shannon.

Hansley, P.L.; Whitney, C.G.

1990-01-01

335

Results of new petrologic and remote sensing studies in the Big Bend region  

NASA Astrophysics Data System (ADS)

The initial section of this manuscript involves the South Rim Formation, a series of 32.2-32 Ma comenditic quartz trachytic-rhyolitic volcanics and associated intrusives, erupted and was emplaced in Big Bend National Park, Texas. Magmatic parameters have only been interpreted for one of the two diverse petrogenetic suites comprising this formation. Here, new mineralogic data for the South Rim Formation rocks are presented. Magmatic parameters interpreted from these data assist in deciphering lithospheric characteristics during the mid-Tertiary. Results indicate low temperatures (< 750 °C), reduced conditions (generally below the FMQ buffer), and low pressures (? 100 MPa) associated with South Rim Formation magmatism with slight conditional differences between the two suites. Newly discovered fayalite microphenocrysts allowed determination of oxygen fugacity values (between -0.14 and -0.25 DeltaFMQ over temperature ranges of 680-700 °C), via mineral equilibria based QUILF95 calculations, for Emory Peak Suite. Petrologic information is correlated with structural evidence from Trans-Pecos Texas and adjacent regions to evaluate debated timing of tectonic transition (Laramide compression to Basin and Range extension) and onset of the southern Rio Grande Rift during the mid-Tertiary. The A-type and peralkaline characteristics of the South Rim Formation and other pre-31 Ma magmatism in Trans-Pecos Texas, in addition to evidence implying earlier Rio Grande Rift onset in Colorado and New Mexico, promotes a near-neutral to transtensional setting in Trans-Pecos Texas by 32 Ma. This idea sharply contrasts with interpretations of tectonic compression and arc-related magmatism until 31 Ma as suggested by some authors. However, evidence discussed cannot preclude a pre-36 Ma proposed by other authors. The later section of this manuscript involves research in the Big Bend area using Google Earth. At present there is high interest in using Google Earth in a variety of scientific investigations. However, program developers have disclosed limited information concerning the program and its accuracy. While some authors have attempted to independently constrain the accuracy of Google Earth, their results have potentially lost validity through time due to technological advances and updates to imagery archives. For this reason we attempt to constrain more current horizontal and vertical position accuracies for the Big Bend region of West Texas. In Google Earth a series of 268 data points were virtually traced along various early Tertiary unconformities in Big Bend National Park and Big Bend Ranch State Park. These data points were compared with high precision GPS measurements collected in field and yielded a horizontal position accuracy of 2.64 meters RMSE. Complications arose in determining vertical position accuracy for Google Earth because default keyhole markup language (.kml) files currently do not export elevation data. This drawback forces users to hand record and manually input elevation values listed on screen. This is a significant handicap rendering Google Earth data useless with larger datasets. However, in a workaround solution exempted elevation values can be replaced from other data sources based on Google Earth horizontal positioning. We used Fledermaus 3D three-dimensional visualization software to drape Google Earth horizontal positions over a National Elevation Dataset (NED) digital elevation map (DEM) in order to adopt a large set of elevation data. A vertical position accuracy of 1.63 meters RMSE was determined between 268 Google Earth data points and the NED. Since determined accuracies were considerably lower than those reported in previous investigations, we devoted a later portion of this investigation to testing Google Earth-NED data in paleo-surface modeling of the Big Bend region. An 18 x 30 kilometer area in easternmost Big Ranch State Park was selected to create a post-Laramide paleo-surface model via interpolation of approximately 2900 Google Earth-NED data points representing sections of an early Tertiary

Benker, Stevan Christian

336

Transition of a dental histology course from light to virtual microscopy.  

PubMed

The transition of the dental histology course at the University of Texas Health Science Center at San Antonio Dental School was completed gradually over a five-year period. A pilot project was initially conducted to study the feasibility of integrating virtual microscopy into a traditional light microscopic lecture and laboratory course. Because of the difficulty of procuring quality calcified and decalcified sections of teeth, slides from the student loan collection in the oral histology block of the course were outsourced for conversion to digital images and placed on DVDs along with a slide viewer. The slide viewer mimicked the light microscope, allowing horizontal and vertical movement and changing of magnification, and, in addition, a feature to capture static images. In a survey, students rated the ease of use of the software, quality of the images, maneuverability of the images, and questions regarding use of the software, effective use of laboratory, and faculty time. Because of the positive support from the students, our entire student loan collection of 153 glass slides was subsequently converted to virtual images and distributed on an Apricorn pocket external hard drive. Students were asked to assess the virtual microscope over a four-year period. As a result of the surveys, light microscopes have been totally eliminated, and microscope exams have been replaced with project slide examinations. In the future, we plan to expand our virtual slides and incorporate computer testing. PMID:19805786

Weaker, Frank J; Herbert, Damon C

2009-10-01

337

Virtual Cluster Development Environment for grids  

Microsoft Academic Search

Virtualization is a promising technology that has attracted much attention, particularly in the grid community. Recent advances using virtualization technologies enable multiplexing the physical resources by means of virtual machines resulting in better resource utilization. We have proposed virtual cluster development environment (VCDE) to dynamically form virtual cluster on demand providing the grid execution environment using Virtual machines. The formation

S. Thamarai Selvi; R. Kumar; P. Balakrishnan; R. A. Balachandar; K. Rajendar; R. Rajiv; G. Kannan; E. Mahendran; B. Madhusudhanan; G. R. Britto

2008-01-01

338

An Automated Virtualization Performance Analysis Platform  

Microsoft Academic Search

This research compares three traditional categories of virtualization to a technique known as hybrid virtualization. Each technique is evaluated in terms of both capability and performance. The traditional methods of platform virtualization such as full virtualization, paravirtualization and operating system virtualization each comes with its own set of capabilities and engineering trade-offs. Hybrid virtualization attempts to leverage the benefits of

Kyle E Stewart; Jeffrey W Humphries; Todd R Andel

2012-01-01

339

TECHNOLOGY APPLICATION: VIRTUAL FIELD TRIPS  

NSDL National Science Digital Library

This webquest will assist in furthering your understanding of the ins and outs of virtual fieldtrips, provide links to ready-made virtual fieldtrips, and provide a link so you can create your own virtual field trip. Virtual field trips have become increasingly popular with the extensive use of the world wide web. One reason for this is probably the ease with which this technology can be delivered. All that is required is a computer with internet access. Occasionally a virtual field trip will require some plug-ins ...

Hoskins, Mr.

2006-03-23

340

The role of petrology in defining volcanic hazards and designing monitoring systems  

NASA Astrophysics Data System (ADS)

Petrology is the study of magmatic systems; physical volcanology investigates processes of eruption. Physical volcanology provides the pre-eminent underpinning of the practical business of defining hazard scenarios, planning mitigation and designing monitoring strategies. Recent research in a variety of volcanic settings has demonstrated an important link between the petrologic processes that at a fundamental level drive the behavior of volcanoes and the processes that determine the eruptive style of a volcano. Together these define the hazards that arise from volcanic eruptions. Petrological studies of volcanoes are typically based on a study of lava because coherent rock is less vulnerable to weathering and alteration and is more durable in the geological record. Pyroclastic materials are commonly friable and glassy, are more easily eroded, and are more difficult to use in the analytical techniques that have become the staple basis of petrological studies. However, pyroclastic materials represent a complementary but different part of the magmatic story and it is only by integrating both effusive and explosive components of an eruption sequence that a complete picture of the behavior of the system feeding a volcano can be gained. Andesitic strato-cones are made up of a cone-building facies consisting mainly of primary magmatic products and usually dominated by lava flows because pyroclastic material is easily eroded from the slopes of a steep cone. The surrounding ring plain facies includes primary pyroclastic deposits but is typically dominated by redistributed material in the form of debris flow and lahar deposits together with reworked fluvial material. The deposits of each of these two facies are assembled on different time scales and they contain different aspects of the record of the evolution of the magmatic system that gave rise to them. An important practical consequence of this is that different parts of the geochemical record of the system can occur in different parts of the volcano. Integrated petrological and volcanological studies on the andesite volcanoes of northern New Zealand have identified repeated cycles of deep seated behavior that translate directly into patterns in eruptive behavior. Further, it has been possible to define long term petrological evolutionary trends which provide a framework for understanding shorter term cycles. On an even shorter time scale the flux of magma through the near vent environment can be investigated by means of the stabilities of mineral phases vulnerable to variable cooling rates. Thus the fundamental behavior of andesitic volcanoes as defined by an understanding of the underlying magmatic system can provide the foundation for robust probabilistic time-varying hazard forecasts as well as strategies for monitoring potentially active volcanoes.

Smith, I. E.; Turner, M. B.; Price, R. C.; Cronin, S. J.

2011-12-01

341

Microscopic approach to entropy production  

NASA Astrophysics Data System (ADS)

It is a great challenge of nonequilibrium statistical mechanics to calculate entropy production within a microscopic theory. In the framework of linear irreversible thermodynamics, we combine the Mori-Zwanzig-Forster projection operator technique with the first and second law of thermodynamics to obtain microscopic expressions for the entropy production as well as for the transport equations of the entropy density and its time correlation function. We further present a microscopic derivation of a dissipation functional from which the dissipative dynamics of an extended dynamical density functional theory can be obtained in a formally elegant way.

Wittkowski, Raphael; Löwen, Hartmut; Brand, Helmut R.

2013-09-01

342

Virtual Yeast Cell  

NSDL National Science Digital Library

Learning about the various parts of a cell can be tricky business, but this virtual yeast cell offered by The University of Nottingham will come in handy for biology students and science instructors. This learning resource was created to help students in the brewing science program learn about yeast cytology, though just about anyone with an interest in cells will learn something from visiting the site. After entering the interactive cell, visitors can click on different parts of the cell (such as the cytoplasm or the nucleus) in order to learn more about the importance of each one. Visitors should remember that they can also download the virtual yeast cell and use it in the classroom or just with a group of friends.

2008-02-28

343

Virtual Yeast Cell  

NSDL National Science Digital Library

Learning about the various parts of a cell can be tricky business, but this virtual yeast cell offered by The University of Nottingham will come in handy for biology students and science instructors. This learning resource was created to help students in the brewing science program learn about yeast cytology, though just about anyone with an interest in cells will learn something from visiting the site. After entering the interactive cell, visitors can click on different parts of the cell (such as the cytoplasm or the nucleus) in order to learn more about the importance of each one. Visitors should remember that they can also download the virtual yeast cell and use it in the classroom or just with a group of friends.

344

The Virtual Bookshelf  

NSDL National Science Digital Library

Island Multimedia has created a virtual library of full-text electronic books, many of which are geared toward a young adult audience. The current selection of 18 titles includes works by American authors Willa Cather, Nathaniel Hawthorne, Edgar Allan Poe, and Mark Twain. The difference between this site and those of other electronic publishers is that here Internauts can register for their own free "virtual bookshelf." With registration comes the ability to highlight favorite passages to return to later, as well as the ability to state preferences for font and background color of the books on your personal bookshelf. Unregistered visitors can click on any "Add to Shelf" box to bring up a registration form. The site has also provided a toll-free phone number for a help line.

1997-01-01

345

Virtual Mineral Exhibit  

NSDL National Science Digital Library

This is the New York State Museum's virtual exhibit of minerals, which are classified in cases referenced by topic, location, and sponsor. The minerals are presented as a thumbnail image with specifications. Clicking on the thumbnail gives one a large zoomable image. Other exhibitions at the museum site include Splendor in Stone: Photomicrographs of Stone, which is a collection of photomicrographs of thin sections of rocks. A 3D (three-dimensional) index of minerals is also available.

346

DNA Extraction Virtual Lab  

NSDL National Science Digital Library

This virtual lab from the Genetic Science Learning Center at the University of Utah provides a simple overview of DNA extraction, including what it's used for, illustrations, and an activity using cheek cells and laboratory equipment to isolate DNA. The lab is followed by a classroom activity that allows students and teachers to Extract DNA from Anything Living, using household items like spinach but not little sister's big toe.

2006-01-01

347

Virtual quantum subsystems.  

PubMed

The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set A of operationally relevant observables. The algebraic structure of A selects a preferred tensor product structure, i.e., a partition into subsystems. The notion of compoundness for quantum systems is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies PMID:11497917

Zanardi, P

2001-08-13

348

THE VIRTUAL BIOECONOMY  

Microsoft Academic Search

This article considers how the bioeconomy—conceived as a market constituted by and constituting technologies derived from the biosciences—can be usefully considered as a virtual economy in that the representations and practices of economic activity differ significantly from one another. It does so through an analysis of the economic theories on spatial innovation processes (e.g. clusters) that have proved a popular

Kean Birch

2007-01-01

349

Virtual Laboratory: Potential Energy  

NSDL National Science Digital Library

This web page provides an introduction to mechanical energy, focusing on gravity. It includes a java simulation of a dropped ball showing the conversion of potential energy into kinetic energy. Non-elastic collisions with the ground are included, although there is no discussion of the resultant lost energy. Users can change the mass, initial energy, and percentage of the energy lost during collisions. This item is part of a larger collection of virtual laboratories for physics, astronomy, and environmental science.

Bothun, Gregory

2007-12-03

350

Virtual nuclear weapons  

SciTech Connect

The term virtual nuclear weapons proliferation and arsenals, as opposed to actual weapons and arsenals, has entered in recent years the American lexicon of nuclear strategy, arms control, and nonproliferation. While the term seems to have an intuitive appeal, largely due to its cyberspace imagery, its current use is still vague and loose. The author believes, however, that if the term is clearly delineated, it might offer a promising approach to conceptualizing certain current problems of proliferation. The first use is in a reference to an old problem that has resurfaced recently: the problem of growing availability of weapon-usable nuclear materials in civilian nuclear programs along with materials made `excess` to defense needs by current arms reduction and dismantlement. It is argued that the availability of these vast materials, either by declared nuclear-weapon states or by technologically advanced nonweapon states, makes it possible for those states to rapidly assemble and deploy nuclear weapons. The second use has quite a different set of connotations. It is derived conceptually from the imagery of computer-generated reality. In this use, one thinks of virtual proliferation and arsenals not in terms of the physical hardware required to make the bomb but rather in terms of the knowledge/experience required to design, assemble, and deploy the arsenal. Virtual weapons are a physics reality and cannot be ignored in a world where knowledge, experience, materials, and other requirements to make nuclear weapons are widespread, and where dramatic army reductions and, in some cases, disarmament are realities. These concepts are useful in defining a continuum of virtual capabilities, ranging from those at the low end that derive from general technology diffusion and the existence of nuclear energy programs to those at the high end that involve conscious decisions to develop or maintain militarily significant nuclear-weapon capabilities.

Pilat, J.F.

1997-08-01

351

The Virtual Body  

NSDL National Science Digital Library

The Virtual Body from MEDtropolis.com is an interactive overview of some of the basic structure and function of the human body. The site, available in both English and Spanish, is a mix of information and activities focused on four areas -- the brain, skeleton, heart, and digestive tract. The site's extensive array of diagrams and images, as well as its interactive nature, enhance the site's appeal and educational potential.

1999-01-01

352

Virtual environment display system  

Microsoft Academic Search

A head-mounted, wide-angle, stereoscopic display system controlled by operator position, voice and gesture has been developed for use as a multipurpose interface environment. The system provides a multisensory, interactive display environment in which a user can virtually explore a 360-degree synthesized or remotely sensed environment and can viscerally interact with its components. Primary applications of the system are in telerobotics,

S. S. Fisher; M. McGreevy; J. Humphries; W. Robinett

1987-01-01

353

A Virtual, Shoestring Vacation  

ERIC Educational Resources Information Center

If there is a discrepancy between the scope of your imagination and the depth of your bank account, this may be the ideal summer to stretch your horizons by diving into a good book. You can take a virtual vacation to almost any place or time by reading. You will not need to fill your gas tank or empty your pocketbook. Reading has a small carbon…

Texley, Juliana

2009-01-01

354

The Virtual Immunology Lab  

NSDL National Science Digital Library

Components of the immune system called antibodies are found in the liquid portion of blood and help protect the body from harm. Antibodies can also be used outside the body in a laboratory-based assay to help diagnose disease caused by malfunctions of the immune system or by infections.This virtual laboratory will demonstrate how such a test, termed an enzyme-linked immunosorbent assay (ELISA), is carried out and show some of the key experimental problems that may be encountered.

Joseph Perpich, M.D., J.D. (Howard Hughes Medical Institute;)

2008-04-16

355

Canada Virtual Science Fair  

NSDL National Science Digital Library

Real science fairs can be great fun, but there's nothing wrong with a virtual science fair, and in the case of the Canada Virtual Science Fair, there's so much that's right. Started in 1999, the Virtual Science Fair is an annual online science and technology contest open to all Canadian students in grades K-12. While non-Canadians aren't eligible to participate, everyone can benefit from the tremendous science education resources on the site. First off, visitors will want to learn about the past winning projects by clicking on the "All Projects" section on the site. Visitors to this section will learn about each project, their team, and so on. Along the right side of the homepage visitors can view the "Special Awards" area. Here they will find information about interesting projects that include "Harvesting Our Nature's Gas Station", "Ice: A Slippery Topic", and "River Pollutants Effect on River Bacteria". Additionally, visitors should be sure to check out their weblog and their online forum.

2008-01-01

356

Neuroelectric Virtual Devices  

NASA Technical Reports Server (NTRS)

This paper presents recent results in neuroelectric pattern recognition of electromyographic (EMG) signals used to control virtual computer input devices. The devices are designed to substitute for the functions of both a traditional joystick and keyboard entry method. We demonstrate recognition accuracy through neuroelectric control of a 757 class simulation aircraft landing at San Francisco International Airport using a virtual joystick as shown. This is accomplished by a pilot closing his fist in empty air and performing control movements that are captured by a dry electrode array on the arm which are then analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. We then demonstrate finer grain motor pattern recognition through a virtual keyboard by having a typist tap his traders on a typical desk in a touch typist position. The EMG signals are then translated to keyboard presses and displayed. The paper describes the bioelectric pattern recognition methodology common to both examples. Figure 2 depicts raw EMG data from typing, the numeral '8' and the numeral '9'. These two gestures are very close in appearance and statistical properties yet are distinguishable by our hidden Kharkov model algorithms. Extensions of this work to NASA emissions and robotic control are considered.

Wheeler, Kevin; Jorgensen, Charles

2000-01-01

357

Tele Hyper Virtuality  

NASA Technical Reports Server (NTRS)

In the future, remote images sent over communication lines will be reproduced in virtual reality (VR). This form of virtual telecommunications, which will allow observers to engage in an activity as though it were real, is the focus of considerable attention. Taken a step further, real and unreal objects will be placed in a single space to create an extremely realistic environment. Here, imaginary and other life forms as well as people and animals in remote locations will gather via telecommunication lines that create a common environment where life forms can work and interact together. Words, gestures, diagrams and other forms of communication will be used freely in performing work. Actual construction of a system based on this new concept will not only provide people with experiences that would have been impossible in the past, but will also inspire new applications in which people will function in environments where it would have been difficult if not impossible for them to function until now. This paper describes Tele Hyper Virtuality concept, its definition, applications, the key technologies to accomplish it and future prospects.

Terashima, Nobuyoshi

1994-01-01

358

Virtual blood bank  

PubMed Central

Virtual blood bank is the computer-controlled, electronically linked information management system that allows online ordering and real-time, remote delivery of blood for transfusion. It connects the site of testing to the point of care at a remote site in a real-time fashion with networked computers thus maintaining the integrity of immunohematology test results. It has taken the advantages of information and communication technologies to ensure the accuracy of patient, specimen and blood component identification and to enhance personnel traceability and system security. The built-in logics and process constraints in the design of the virtual blood bank can guide the selection of appropriate blood and minimize transfusion risk. The quality of blood inventory is ascertained and monitored, and an audit trail for critical procedures in the transfusion process is provided by the paperless system. Thus, the virtual blood bank can help ensure that the right patient receives the right amount of the right blood component at the right time.

Wong, Kit Fai

2011-01-01

359

High efficiency virtual impactor  

DOEpatents

Environmental monitoring of atmospheric air is facilitated by a single stage virtual impactor (11) for separating an inlet flow (Q.sub.O) having particulate contaminants into a coarse particle flow (Q.sub.1) and a fine particle flow (Q.sub.2) to enable collection of such particles on different filters (19a, 19b) for separate analysis. An inlet particle acceleration nozzle (28) and coarse particle collection probe member (37) having a virtual impaction opening (41) are aligned along a single axis (13) and spaced apart to define a flow separation region (14) at which the fine particle flow (Q.sub.2) is drawn radially outward into a chamber (21) while the coarse particle flow (Q.sub.1) enters the virtual impaction opening (41). Symmetrical outlet means (47) for the chamber (21) provide flow symmetry at the separation region (14) to assure precise separation of particles about a cutpoint size and to minimize losses by wall impaction and gravitational settling. Impulse defocusing means (42) in the probe member (37) provides uniform coarse particle deposition on the filter (19a) to aid analysis. Particle losses of less than 1% for particles in the 0 to 20 micron range may be realized.

Loo, Billy W. (Oakland, CA)

1981-01-01

360

Adirondack Under the Microscope-2  

NASA Technical Reports Server (NTRS)

This overhead look at the martian rock dubbed Adirondack was captured by the Mars Exploration Rover Spirit's panoramic camera. It shows the approximate region where the rover's microscopic imager began its first close-up inspection.

2004-01-01

361

Vise holds specimens for microscope  

NASA Technical Reports Server (NTRS)

Convenient, miniature, spring-loaded clamp holds specimens for scanning electron microscope. Clamp is made out of nesting sections of studded angle-aluminum. Specimens are easier to mount and dismount with vise than with conductive adhesive or paint.

Greule, W. N.

1980-01-01

362

Microscopic Procedures for Plant Meiosis.  

ERIC Educational Resources Information Center

Describes laboratory techniques designed to familiarize students with meiosis and how microscopic preparations of meiosis are made. These techniques require the use of fresh or fixed flowers. Contains 18 references. (DDR)

Braselton, James P.

1997-01-01

363

Atomic force microscope: Enhanced sensitivity.  

National Technical Information Service (NTIS)

Atomic force microscopes (AFMs) are a recent development representing the state of the art in measuring ultrafine surface features. Applications are found in such fields of research as biology, microfabrication, material studies, and surface chemistry. Fi...

D. T. Davis

1995-01-01

364

(Center of excellence: Microlaser microscope)  

SciTech Connect

This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

Webb, R.H.

1992-01-01

365

Circular Extinction Contrast Imaging Microscope.  

National Technical Information Service (NTIS)

Systems and methods for producing circular extinction (CE) contrast images of anisotropic samples. Microscope systems for determining circular extinction (CE), the differential transmission of left and right circularly polarized light resulting from circu...

B. Kahr W. Kaminsky

2004-01-01

366

Microscopic description of fission properties  

SciTech Connect

Microscopic results on fission barriers, partial {gamma}-back and fission lifetimes of shape isomers are presented. They have been obtained from mean-field and beyond mean-field calculations using the effective D1S Gogny force.

Goutte, H.; Delaroche, J.-P.; Girod, M. [CEA/DAM Ile de France, DPTA/Service de Physique Nucleaire, BP 12, 91680 Bruyeres-le-Chatel (France); Libert, J. [Institut de Physique Nucleaire, CNRS-IN2P3 and Universite Paris XI, 15 rue Georges Clemenceau, 91406 Orsay (France)

2007-02-26

367

On thermodynamic and microscopic reversibility  

SciTech Connect

The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

Crooks, Gavin E.

2011-07-12

368

Single-wavelength STED microscope  

NASA Astrophysics Data System (ADS)

The zero-point STED microscope (US Pat. 5,866,911)1 was the first far-field microscope to overcome the diffraction limit, but optimally it requires two expensive synchronized short-pulsed lasers. Replacing the synchronized pulsed lasers with CW lasers had been proposed to reduce costs1, but this seriously reduced resolution compared to a similarly powered pulsed STED microscope. A recent theoretical and experimental study (Nat. Methods 4, 915 (2007))3 argued that CW STED has better resolution than previously believed, but there appear to be flaws in the theory sufficient to raise questions about its reported experimental confirmation. We describe an alternative approach to reducing cost of the STED microscope while preserving resolution. A portion of the beam from a femtosecond pulsed laser of a wavelength able to excite fluorescence by multiphoton absorption, is passed through a long optical fiber to stretch the pulses to reduce their peak power so they can no longer excite but can quench by stimulated emission. The stretched pulses are shaped into a doughnut profile and then recombined with the first beam for interaction with the specimen. With suitable fluorophores, this instrument should be able to match the resolution performance of the pulsed laser STED microscope using separate lasers. Particularly when added to an existing multiphoton microscope, such performance should be achievable at extremely low added cost.

Baer, Stephen C.

2011-02-01

369

Mineralogy, petrology and chemistry of ANT-suite rocks from the lunar highlands  

NASA Technical Reports Server (NTRS)

Anorthositic-noritic-troctolitic (ANT) rocks are the oldest and most abundant rocks of the lunar surface, and comprise about 90% of the suite of the lunar highlands. Consideration is given to the mineralogy, petrology, bulk chemistry, and origin of ANT-suite rocks. Problems associated in classifying and labeling lunar highland rocks because of textural complexities occurring from impact modifications are discussed. The mineralogy of ANT-suite rocks, dominated by plagioclase, olivine and pyrozene, and containing various minor minerals, is outlined. The petrology of ANT-suite rocks is reviewed along with the major element bulk composition of these rocks, noting that they are extremely depleted in K2O and P2O5. Various models describing the origin of ANT-suite rocks are summarized, and it is suggested that this origin involves a parental liquid of high-alumina basalt with low Fe/Fe+Mg.

Prinz, M.; Keil, K.

1977-01-01

370

Constraints on chondrule origin from petrology of isotopically characterized chondrules in the Allende meteorite  

SciTech Connect

The petrologic and chemical properties of the ferromagnesian chondrules in the Allende carbonaceous chondrite were examined in terms of the isotopic composition and the correlations between isotopic patterns. Areas of thin sections were studied with a SEM and bulk chemical fractions of 12 constituents were quantified to calculate correlations with petrologic features. A possible correlation between (CaO + Al2O2)/MgO and oxygen isotopes imply the formation of oxygen isotopic compositions in the chondrules by exchanges between isotopically heavy nebular gases and O-16 enriched solids. Different rates of gaseous exchange occurred with the various types of chondrules. Factors which may have controlled the exchanges are discussed. 21 references.

Mcsween, H.Y. Jr.

1985-09-01

371

Fractal approach in petrology: Small-angle neutron scattering experiments with volcanic rocks  

SciTech Connect

Following Mandelbrot's pioneering work in 1977, we attempt to use the concept of fractal dimension in petrology. Fractal dimension is an intensive property of matter which offers a quantitative measure of the degree of surface roughness. Neutron scattering experiments have been performed on 18 volcanic rocks from different localities. The scattered intensity as a function of the momentum transfer obeys a power law whose exponent varies, for the rock samples presented, between -3 and -4. We conclude that, at the molecular level, our volcanic rocks are not fractal volumes. With regard to the particle-matrix interface, it is not possible to provide a determination at the present stage of research. Our findings suggest it is feasible to verify the degree of surface irregularity at a resolution which is relevant to many aspects of petrology.

Lucido, G.; Triolo, R.; Caponetti, E.

1988-11-01

372

The lunar regolith - Chemistry and petrology of Luna 24 grain size fractions  

NASA Technical Reports Server (NTRS)

Chemical data obtained by instrumental neutron activation analysis are reported for 30 elements in eight lunar soil size fractions from 370 to less than 2 microns, as well as petrology for five size fractions down to 40-10 microns in two Luna 24 soils. While the compositions of coarser fractions are similar to each other, they differ from the fractions smaller than 10 microns; these become increasingly feldspathic and enriched in large ion lithophile elements (LILE) with decreasing grain size. The high concentrations of the Ni, Au and Ir meteoritic indicator elements in these finer fractions are consistent with comminution by meteoritic impact. Size distributions, petrology and LILE patterns indicate that Luna 24 soils are less reworked than most lunar soils.

Laul, J. C.; Rode, O. D.; Simon, S. B.; Papike, J. J.

1987-01-01

373

Mineralogy, petrology and geochemistry of carbonaceous chondritic clasts in the LEW 85300 polymict eucrite  

NASA Technical Reports Server (NTRS)

We have performed a detailed petrologic and mineralogic study of two chondritic clasts from the polymict eucrite Lewis Cliff (LEW) 85300, and performed chemical analyses by INAA and RNAA on one of these. Petrologically, the clasts are identified and are composed of dispersed aggregates, chondrules, and chondrule fragments supported by matrix. The aggregates and chondrules are composed of olivine, orthopyroxene, plus some diopside. The matrix consists of fine-grained olivine, and lesser orthopyroxene and augite. Fine-grained saponite is common in the matrix. The bulk major composition of the clast studied by INAA and RNAA shows unusual abundance patterns for lithophile, siderophile and chalcophile elements but is basically chondritic. The INAA/RNAA data preclude assignment of the LEW 85300,15 clast to any commonly accepted group of carbonaceous chondrite.

Zolensky, M. E.; Hewins, R. H.; Mittlefehldt, D. W.; Lindstrom, M. M.; Xiao, X.; Lipschutz, M. E.

1992-01-01

374

PETRO.CALC.PLOT, Microsoft Excel macros to aid petrologic interpretation  

USGS Publications Warehouse

PETRO.CALC.PLOT is a package of macros which normalizes whole-rock oxide data to 100%, calculates the cation percentages and molecular proportions used for normative mineral calculations, computes the apices for ternary diagrams, determines sums and ratios of specific elements of petrologic interest, and plots 33 X-Y graphs and five ternary diagrams. PETRO.CALC.PLOT also may be used to create other diagrams as desired by the user. The macros run in Microsoft Excel 3.0 and 4.0 for Macintosh computers and in Microsoft Excel 3.0 and 4.0 for Windows. Macros provided in PETRO.CALC.PLOT minimize repetition and time required to recalculate and plot whole-rock oxide data for petrologic analysis. ?? 1994.

Sidder, G. B.

1994-01-01

375

Crustal structure beneath Montserrat, Lesser Antilles, constrained by xenoliths, seismic velocity structure and petrology  

NASA Astrophysics Data System (ADS)

Noritic anorthosite, gabbroic anorthosite and hornblende-gabbro xenoliths are ubiquitous in the host andesite at Montserrat. Other xenoliths include quartz diorite, metamorphosed biotite-gabbro, plagioclase-hornblendite and plagioclase-clinopyroxenite. Mineral compositions suggest a majority of the xenoliths are cognate. Cumulate, hypabyssal and crescumulate textures are present. A majority of the xenoliths are estimated to have seismic velocities of 6.7-7.0 km/s for pore-free assemblages. These estimates are used in conjunction with petrological models to constrain the SEA CALIPSO seismic data and the structure of the crust beneath Montserrat. Andesitic upper crust is interpreted to overlie a lower crust dominated by amphibole and plagioclase. Xenolith textures and seismic data indicate the presence of hypabyssal intrusions in the shallow crust. The structure of the crust is consistent with petrological models indicating that fractionation is the dominant process producing andesite at Montserrat.

Kiddle, E. J.; Edwards, B. R.; Loughlin, S. C.; Petterson, M.; Sparks, R. S. J.; Voight, B.

2010-04-01

376

Virtual Human Problem Solving Environments  

SciTech Connect

Abstract. Interest in complex integrated digital or virtual human modeling has seen a significant increase over the last decade. Coincident with that increased interest, Oak Ridge National Laboratory (ORNL) initiated the development of a human simulation tool, the Virtual Human. The Virtual Human includes a problem-solving environment (PSE) for implementing the integration of physiological models in different programming languages and connecting physiological function to anatomy. The Virtual Human PSE (VHPSE) provides the computational framework with which to develop the concept of a "Virtual Human." Supporting the framework is a data definition for modeling parameters, PhysioML, a Virtual Human Database (VHDB), and a Web-based graphical user interface (GUI) developed using Java. Following description of the VHPSE, we discuss four example implementations of models within the framework. Further expansion of a human modeling environment was carried out in the Defense Advanced Research Projects Agency Virtual Soldier Project. SCIRun served as the Virtual Soldier problem solving environment (VSPSE). We review and compare specific developments in these projects that have significant potential for the future of Virtual Human modeling and simulation. We conclude with an evaluation of areas of future work that will provide important extensions to the VHPSE and VSPSE and make possible a fully-integrated environment for human anatomical and physiological modeling: the Virtual Human.

Ward, Richard C [ORNL; Pouchard, Line Catherine [ORNL; Munro, Nancy B [ORNL; Fischer, Sarah Kathleen [ORNL

2008-01-01

377

The petrologic evolution and pre-eruptive conditions of the rhyolitic Kos Plateau Tuff (Aegean arc)  

Microsoft Academic Search

The Kos Plateau Tuff is a large (>60 km3) and young (160 k.y.) calc-alkaline, high-SiO2 rhyolitic ignimbrite from the active Kos-Nisyros volcanic center in the Aegean arc (Greece). Combined textural, petrological\\u000a and geochemical information suggest that (1) the system evolved dominantly by crystal fractionation from (mostly unerupted)\\u000a more mafic parents, (2) the magma chamber grew over ? 250 000 years

Olivier Bachmann

2010-01-01

378

PETROLOGY OF VARISCAN GRANITOIDS IN TISIA COMPOSITE TERRANE (BÉKÉSIA TERRANE - SE HUNGARY)  

Microsoft Academic Search

The aim of the research was the petrological study of granitoid rocks located in the axis zone of the crystalline domes (Deszk-Ferencszállás-Makó-Mezõhegyes-Battonya) of the Békésia Terrane - Tisia Composite Terrain (SE Hungary). The studied samples (alkali granite, syeno- monzogranite and granodiorite) are S-type, subalkaline, calc-alkaline rocks of prealuminous character. Concerning their tectonical origin, the crustal granites were formed by continental

E. PÁL-MOLNÁR; G. KOVÁCS

379

Research in volcanic geology, petrology and planetary science at MIT, 1969 to 1974  

NASA Technical Reports Server (NTRS)

The behavior of volcanoes was studied by geologic mapping, petrologic investigations of lava and xenoliths, physical measurements, and theoretical modelling. Field observations were conducted in Alaska (Nunivak Island), Iceland, Hawaii (Mauna Kea), Italy (Etna, Stromboli), and Arizona. The results are discussed and compared with known data for lunar and planetary gelogy. Field methods used for the volcano research are cited and a list is given of all participating scientists and students. Publications and abstracts resulting from the research are also listed.

Mcgetchin, T. R.

1974-01-01

380

Petrology and geochemistry of a diamondiferous lherzolite from the Premier diamond mine, South Africa  

Microsoft Academic Search

This paper reports on the petrology and geochemistry of a diamondiferous peridotite xenolith from the Premier diamond mine in South Africa.The xenolith is altered with pervasive serpentinisation of olivine and orthopyroxene. Garnets are in an advanced state of kelyphitisation but partly fresh. Electron microprobe analyses of the garnets are consistent with a lherzolitic paragenesis (8.5 wt.% Cr2O3 and 6.6 wt.%

René Dobbe; Braam Smit; Emilie Thomassot; Pierre Cartigny

2004-01-01

381

Report of the Workshop on Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of Martian Meteorites  

NASA Technical Reports Server (NTRS)

Geochemical and petrologic studies of the Martian meteorites (nicknamed the SNCs) have proliferated in the past few years, from a wealth of new samples and the perfection of new analytical methods. An intriguing result from these studies is that the chemical and isotopic compositions of the Martian meteorites, all basalts or derived from basaltic magma, can be modeled as mixtures of a limited number of components. These mixing components were the focus of the workshop.

Treiman, Allan H. (Editor); Herd, Christopher D. K. (Editor)

2002-01-01

382

Distribution of terrestrial age and petrologic type of meteorites from western Libya  

NASA Technical Reports Server (NTRS)

A group of 54 meteorites have been recovered from Daraj, Western Libya. After assessment of pairing of samples, using petrologic criteria, C-14 terrestrial ages were obtained on 13 samples selected from 9 different fall events. Eleven of the ages range from 3500 to 7600 years, with only two samples having ages in excess of 10,000 years. The cutoff in ages may be related to the timing of climatic changes in the Hammadah al Hamra.

Jull, A. J. T.; Donahue, D. J.; Wlotzka, F.; Palme, H.

1990-01-01

383

Mineralogy and petrology of basaltic fragments from the Luna 24 drill core  

NASA Technical Reports Server (NTRS)

The petrology of rock fragments and monomineralic grains from Luna 24 samples is described, and a petrogenetic scheme for the derivation of Mare Crisium basalts is presented. Components of the rock fragments include subophitic basalts, metabasalts, late-stage fragments, olivine vitrophyres, and non-mare lithic fragments of possible cumulate origin. Among the monomineralic grains (which are much more abundant than the rock fragments) are pyroxene, plagioclase, olivine, ilmenite and native Fe.

Coish, R. A.; Taylor, L. A.

1978-01-01

384

A summary of the petrology and geochemistry of pristine highlands rocks  

NASA Technical Reports Server (NTRS)

The petrology and geochemistry of pristine lunar highlands rock samples consisting of ferroan anorthosites, norites, troctolites, spinel troctolites/dunite/lherzolite, and KREEP, are described. In addition, petrographic and chemical evidence is presented which shows that low-siderophile rocks are the result of endogenous igneous activity and not impact melt differentiation. For example, these rocks contain Fe-metal as a late-crystallizing phase, and have W/La ratios higher than polymict breccias.

Norman, M. D.; Ryder, G.

1979-01-01

385

Petrology/Geochemistry/Mineralogy/Structure of Shear zones in St. Lawrence County  

NSDL National Science Digital Library

These rocks were collected from outcrops frequented by structural geology field trips. CCM 42 is from the town of Clare, CCM 43 is from Russell; although labeled CCM, neither is from the Carthoage Colton Mylonite Zone, but both are from shear zones. DEK is from the world famous DeKalb anticline. In this lab we try to pull together material from petrology, geochemistry, mineralogy and structure.

Badger, Robert

386

Pre-virtualization: Soft layering for virtual machines  

Microsoft Academic Search

Despite its current popularity, para-virtualization has an enormous cost. Its deviation from the platform architecture abandons many of the benefits of traditional virtualization: stable and well-defined platform interfaces, hypervisor neutrality, operating system neutrality, and upgrade neutrality - in sum, modularity. Additionally, para-virtualization has a significant engineering cost. These limitations are accepted as inevitable for significantly better performance, and for the

Joshua LeVasseur; Volkmar Uhlig; Yaowei Yang; Matthew Chapman; Peter Chubb; Ben Leslie; Gernot Heiser

2008-01-01

387

ON VIRTUAL CROSSING NUMBER ESTIMATES FOR VIRTUAL LINKS  

Microsoft Academic Search

We address the question of detecting minimal virtual diagrams with respect to\\u000athe number of virtual crossings. This problem is closely connected to the\\u000aproblem of detecting the minimal number of additional intersection points for a\\u000ageneric immersion of a singular link in $R^{2}$.\\u000a We tackle this problem by the so-called $\\\\xi$-polynomial whose leading\\u000a(lowest) degree naturally estimates the virtual

DENIS MIKHAILOVICH AFANASIEV; VASSILY OLEGOVICH MANTUROV

2009-01-01

388

A Virtual Planetary Exploration: Very Large Virtual Environment  

Microsoft Academic Search

IntroductionMoffett Field, CAVirtual Planetary Exploration (VPE) is a NASA Virtual Environment (VE) project. It is alf"research tool for investigating concepts, methods, and user-interaction strategies that may prove usefuor the design of planetary exploration workstations based on the virtual reality paradigm." The goal of1lsthis application is to support "virtual exploration" of planetary terrain that exhibits geomorphologicatructure and detail usable by planetary

Lewis E. Hitchner

1992-01-01

389

Scanning Miniature Microscopes without Lenses  

NASA Technical Reports Server (NTRS)

The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the nonpolarizing beam splitter were replaced by a polarizing one, then the specimen would be illuminated by s-polarized light. Upon reflection from the specimen, some of the s-polarized light would become p-polarized. Only the p-polarized light would contribute to the image on the CCD; in other words, the image would contain information on the polarization rotating characteristic of the specimen.

Wang, Yu

2009-01-01

390

Microscope-assisted precision dentistry.  

PubMed

To enhance their vision for both clinical and laboratory procedures, an increasing number of dental practitioners are introducing magnification into their practices. Most are using either simple or compound loupes mounted on glasses frames. And although magnification is not new to dentistry, it is a trend that is gaining a broader acceptance among both seasoned practitioners and recent graduates. Many dental schools are allowing their students to use loupes on a discretionary basis, so the notion that magnification is reserved only to compensate for deteriorating vision is rapidly disappearing. Dental professionals have also begun to recognize that the quantity and quality of light in the working field is just as important as magnification. Headlamps with focused, color-correct light sources in combination with loupes are becoming popular. It is highly unlikely that a practitioner using loupes would relinquish them and return to practicing without magnification. The newest addition to the vision enhancement arena in dentistry is the operating microscope. In some medical subspecialties--such as otolaryngology, ophthalmology, plastic surgery, and neurosurgery--extensive microsurgical training is required to perform procedures at acceptable standards of precision. In 1998, the American Association of Endodontists (AAE) elected to mandate that all endodontic postgraduate students demonstrate proficiency using an operating microscope before they receive their certificates. Microscope use has also been reported in periodontics. For several decades, many dental laboratory technicians have used stereomicroscopes for trimming dies, refining castings, and performing other procedures that require a high degree of precision. However, according to microscope manufacturers, most current instrument sales are to general practitioners, who are not limiting the use of their microscopes to endodontic therapy--they are using them for a wide variety of procedures. Microscopes have the potential to enhance a dental practitioner's vision to unprecedented levels, but there are some practical questions that need to be addressed. What kind of visual acuity do dentists really need to perform high-quality dentistry? If a dentist wants to improve his or her vision, do loupes provide an adequate level of magnification? Is using a microscope too complicated for restorative and prosthodontic procedures, and how long does it take to become proficient with a microscope? These are some of the questions I posed to two outstanding dentists who have had extensive clinical experience using surgical microscopes. I also share my own experience with a microscope. PMID:10649948

Friedman, M; Mora, A F; Schmidt, R

1999-08-01

391

Virtual Japanese Rhinoceros Beetle  

NSDL National Science Digital Library

This is a 3D virtual reality image of the "Japanese Rhinoceros Beetle," or Allomyrina dichotoma (family Scarabaeidae, subfamily Dynastinae). Menu tools can be used to rotate and/or zoom in on the image. The clarity of the image is excellent, but gets slightly blurry when fully zoomed. This is a high quality resource for teaching, especially for topics involving insect morphology. The Cornell University "Beetle Science" home page (http://www.explore.cornell.edu/scene.cfm?scene=Beetle%20Science) has many more excellent resources for teachers and students. QuickTime 5.0 is required to view it, which possibly could limit users with older or public computers.

0002-11-30

392

Next Generation Virtual Observatories  

NASA Astrophysics Data System (ADS)

Virtual Observatories (VO) are now being established in a variety of geoscience disciplines beyond their origins in Astronomy and Solar Physics. Implementations range from hydrology and environmental sciences to solid earth sciences. Among the goals of VOs are to provide search/ query, access and use of distributed, heterogeneous data resources. With many of these goals being met and usage increasing, new demands and requirements are arising. In particular there are two of immediate and pressing interest. The first is use of VOs by non-specialists, especially for information products that go beyond the usual data, or data products that are sought for scientific research. The second area is citation and attribution of artifacts that are being generated by VOs. In some sense VOs are re-publishing (re-packaging, or generating new synthetic) data and information products. At present only a few VOs address this need and it is clear that a comprehensive solution that includes publishers is required. Our work in VOs and related semantic data framework and integration areas has lead to a view of the next generation of virtual observatories which the two above-mentioned needs as well as others that are emerging. Both of the needs highlight a semantic gap, i.e. that the meaning and use for a user or users beyond the original design intention is very often difficult or impossible to bridge. For example, VOs created for experts with complex, arcane or jargon vocabularies are not accessible to the non-specialist and further, information products the non-specialist may use are not created or considered for creation. In the second case, use of a (possibly virtual) data or information product (e.g. an image or map) as an intellectual artifact that can be accessed as part of the scientific publication and review procedure also introduces terminology gaps, as well as services that VOs may need to provide. Our supposition is that formalized methods in semantics and semantic web technologies are ideal to meet and solve both of these semantic gaps. In this presentation we highlight both of the emerging needs, and current and emerging semantic web solutions that will enable the next generation of virtual observatories. Our work is funded under NSF/OCI and NASA/ACCESS/ESTO projects to the High Altitude Observatory at the National Center for Atmospheric Research (NCAR) and McGuinness Associates Consulting.

Fox, P.; McGuinness, D. L.

2008-12-01

393

NTNU Virtual Physics Laboratory  

NSDL National Science Digital Library

This repository of Java applets, created to demonstrate principles of physics, is provided by physicist Fu-Kwun Hwang of the National Taiwan Normal University. 40 applets are available at this time in the fields of mechanics, dynamics, waves, thermodynamics, electromagnetic field and optics. Although the applets are accompanied by sparse explanatory information, the Virtual Physics Laboratory still would be an excellent supplement to a basic physics class. Note that connection speed to the Taiwanese site is fairly slow and that ten international mirror sites are provided.

Hwang, Fu-Kwun.

2007-05-01

394

Birds: A Virtual Exhibition  

NSDL National Science Digital Library

This site from the Virtual Museum of Canada compiles a wealth of information from five different Canadian museums into one location for the benefit of bird lovers. This site does not provide original information; rather, it links to online bird-related exhibits from each of the five museums, which can be navigated through individually. What makes this site particularly valuable is the ability to perform a search of all five museum exhibits at once, providing a comprehensive source of information for the user that builds on the strengths of each individual exhibit.

1998-01-01

395

Mobile Virtual Private Networking  

NASA Astrophysics Data System (ADS)

Mobile Virtual Private Networking (VPN) solutions based on the Internet Security Protocol (IPSec), Transport Layer Security/Secure Socket Layer (SSL/TLS), Secure Shell (SSH), 3G/GPRS cellular networks, Mobile IP, and the presently experimental Host Identity Protocol (HIP) are described, compared and evaluated. Mobile VPN solutions based on HIP are recommended for future networking because of superior processing efficiency and network capacity demand features. Mobile VPN implementation issues associated with the IP protocol versions IPv4 and IPv6 are also evaluated. Mobile VPN implementation experiences are presented and discussed.

Pulkkis, Göran; Grahn, Kaj; Mårtens, Mathias; Mattsson, Jonny

396

Virtual Turing Machine 2  

NSDL National Science Digital Library

A Turing machine is theoretical computer consisting of a finite set of internal states, a finite alphabet that includes a blank symbol, and a finite set of instructions. It has a physical head and a physical infinitely long tape, which is divided into cells. The cell values consist of the alphabet. The tape has a finite number of non-blank cells. The head can read and write to the cells and move the tape one cell to the left and one cell to the right. The Virtual Turing Machine lets you input tape values and an instruction set to see the output of a turing machine.

Ming, Paul R.

397

"Virtual Feel" Capaciflectors  

NASA Technical Reports Server (NTRS)

The term "virtual feel" denotes a type of capaciflector (an advanced capacitive proximity sensor) and a methodology for designing and using a sensor of this type to guide a robot in manipulating a tool (e.g., a wrench socket) into alignment with a mating fastener (e.g., a bolt head) or other electrically conductive object. A capaciflector includes at least one sensing electrode, excited with an alternating voltage, that puts out a signal indicative of the capacitance between that electrode and a proximal object.

Vranish, John M.

2006-01-01

398

The Virtual Cave  

NSDL National Science Digital Library

Dave Bunnell, a member of the National Speleological Society and cave researcher, and Djuna Bewley created this fascinating website depicting caves from all over the world. With an abundance of images and descriptions, student and educators can learn about solution, lava tube, sea, and erosional caves. When visiting the most extensive link, Solution Caves, users can take a virtual cave tour where they can learn about stalagmites, conulites, helictites, and much more. Visitors interested in taking a trip to a cave can find information about caves throughout the United States as well as suggestions on how to make the most of your trip.

Bewley, Djuna; Bunnell, Dave

399

Real cells - virtual computers.  

PubMed

Now it is quite usual to use real computers to simulate virtual cells. I suggest that real cells (e.g. cells cultured in vitro) might be considered and used as molecular automata. As an imaginary experience, a molecular automata can be built, using real cells and a chemical inert molecule. I suggest that one could be able to test statistical properties of a 2D gas trapped in a box using this sort of automata. Moreover, I would conjecture that any possible algorithm can be implemented in such molecular automata. PMID:12611651

Popescu, George Alex

2002-01-01

400

The Experimental Virtual Environment  

NSDL National Science Digital Library

The Experimental Virtual Environment (EVE) is a project being conducted by the Helsinki University of Technology and the high-performance computing and networking center in Finland. The EVE encloses the user inside three walls and a floor that are rear projection screens, and the user can interact with the environment with a head tracking unit and other sensors. A brief introduction is given on the EVE Web site, followed by examples of applications for the system, its current implementation, and descriptions of past and current projects. A thesis about the EVE implementation goes into much more detail, and there are also several theses and related documents given in the Publications section.

401

The virtual case report.  

PubMed

Reports of clinical happenings are coming under increasing suspicion because of their piecemeal nature and their problematic reliance on memory. Recent research on eyewitness testimony has raised the further concern that memory of an event can be easily and unwittingly influenced by something heard or seen after the fact. Once the psychoanalyst's memory has come under the influence of whatever theory is dominant, we can expect both an overselection of clinical happenings consistent with that theory, and an unwitting alteration of those that do not agree. Seemingly true case reports may be more virtual than veridical. PMID:12391936

Spence, Donald P

2002-10-01

402

The Virtual Terrain Project  

NSDL National Science Digital Library

The Virtual Terrain Project (VTP) homepage has a wealth of information about three dimensional environment rendering, as well as links to many different research efforts and papers about the subject. The project's aim "is to foster the creation of tools for easily constructing any part of the real world in interactive, 3D digital form." Several subtopics are addressed, including plant modeling and realistic ground detailing and texturing. An interesting focus is on cultural aspects of terrain rendering, such as roads, buildings, and other infrastructure. Some images of VTP worlds are shown, and three software titles developed with the project can be downloaded upon request.

2005-11-13

403

Recoverable distributed shared virtual memory  

NASA Technical Reports Server (NTRS)

The problem of rollback recovery in distributed shared virtual environments, in which the shared memory is implemented in software in a loosely coupled distributed multicomputer system, is examined. A user-transparent checkpointing recovery scheme and a new twin-page disk storage management technique are presented for implementing recoverable distributed shared virtual memory. The checkpointing scheme can be integrated with the memory coherence protocol for managing the shared virtual memory. The twin-page disk design allows checkpointing to proceed in an incremental fashion without an explicit undo at the time of recovery. The recoverable distributed shared virtual memory allows the system to restart computation from a checkpoint without a global restart.

Wu, Kun-Lung; Fuchs, W. Kent

1990-01-01

404

Trust Building in Virtual Communities  

NASA Astrophysics Data System (ADS)

By using different types of communication networks various groups of people can come together according to their private or business interest forming a Virtual Community. In these communities cooperation and collaboration plays an important role. As trust is the base of all human interactions this fact is even more valid in case of virtual communities. According to different experiments the level of trust in virtual communities is highly influenced by the way/mode of communication and by the duration of contact. The paper discusses the ways of trust building focusing on communication technologies and security aspects in virtual communities.

Mezgár, István

405

Schema Virtualization in Object-Oriented Databases  

Microsoft Academic Search

A description is given of the concept and implementation techniques of schema virtualization in object-oriented databases. The objective of schema virtualization is to provide users with multiple views of a database. First, the notions of virtual classes and virtual schemata, which are natural extension of views in relational databases, is introduced. Then, procedures to convert a schema into a virtual

Katsumi Tanaka; Masatoshi Yoshikawa; Kozo Ishihara

1988-01-01

406

Microscopic characterization of peptide nanostructures.  

PubMed

Peptide-based nanomaterials have been utilized for various applications from regenerative medicine to electronics since they provide several advantages including easy synthesis methods, numerous routes for functionalization and biomimicry of secondary structures of proteins which leads to design of self-assembling peptide molecules to form nanostructures. Microscopic characterization at nanoscale is critical to understand processes directing peptide molecules to self-assemble and identify structure-function relationship of the nanostructures. Here, fundamental studies in microscopic characterization of peptide nanostructures are discussed to provide insights in widely used microscopy tools. In this review, we will encompass characterization studies of peptide nanostructures with modern microscopes, such as TEM, SEM, AFM, and advanced optical microscopy techniques. We will also mention specimen preparation methods and describe interpretation of the images. PMID:21821422

Mammadov, Rashad; Tekinay, Ayse B; Dana, Aykutlu; Guler, Mustafa O

2012-02-01

407

When Virtual Worlds Expand  

NASA Astrophysics Data System (ADS)

The future of a virtual world depends on whether it can grow in subjective size, cultural content, and numbers of human participants. In one form of growth, exemplified by Second Life, the scope of a world increases gradually as new sponsors pay for new territory and inhabitants create content. A very different form of growth is sudden expansion, as when World of Warcraft (WoW) added entire new continents in its Burning Crusade and Lich King expansions (Lummis and Kern 2006, 2008; Corneliussen and Rettberg 2008; Sims et al. 2008). Well-established gamelike worlds have often undergone many expansions. Both the pioneer science fiction game Anarchy Online, which was launched in 2001, and Star Wars Galaxies dating from 2003, have had three, and EVE Online also from 2003 has had nine, although smaller ones. This chapter reports research on WoW's 2008 Lich King expansion, using both quantitative and qualitative methods, in order to develop theoretical ideas of the implications of expansion for virtual worlds.

Bainbridge, William Sims

408

Virtual Optical Comparator  

SciTech Connect

The Virtual Optical Comparator, VOC, was conceived as a result of the limitations of conventional optical comparators and vision systems. Piece part designs for mechanisms have started to include precision features on the face of parts that must be viewed using a reflected image rather than a profile shadow. The VOC concept uses a computer generated overlay and a digital camera to measure features on a video screen. The advantage of this system is superior edge detection compared to traditional systems. No vinyl charts are procured or inspected. The part size and expensive fixtures are no longer a concern because of the range of the X-Y table of the Virtual Optical Comparator. Product redesigns require only changes to the CAD image overlays; new vinyl charts are not required. The inspection process is more ergonomic by allowing the operator to view the part sitting at a desk rather than standing over a 30 inch screen. The procurement cost for the VOC will be less than a traditional comparator with a much smaller footprint with less maintenance and energy requirements.

Thompson, Greg

2008-10-20

409

Virtual Developing Country  

NSDL National Science Digital Library

Biz/ed recently unveiled this new resource. Virtual Developing Country introduces users to "many of the issues and ideas that are of interest in the field of development economics" by offering a virtual tour of the African country Zambia. On the field trip, users make stops to visit places and meet people that help illustrate economic and development theory. Five field trips are offered: The Rural Life and Agriculture Tour, The Copper Tour, The Trade Tour, The Aid Tour, and The Wildlife Tour. Throughout the tours, users are introduced to the people, places, and sites of Zambia, along with the economic issues related to each tour. Each stop is accompanied by key data and economic theory, photographs, worksheets, and a glossary. The teacher's guide gives a detailed description of the program and offers advice to how to effectively use it in the classroom. This interactive site is an outstanding example of the innovative ways the Web can be used as a teaching tool.

410

The Russian Virtual Observatory  

NASA Astrophysics Data System (ADS)

The Russian Virtual Observatory (RVO) will be an integral component of the International Virtual Observatory (IVO). The RVO has the main goal of integrating resources of astronomical data accumulated in Russian observatories and institutions (databases, archives, digitized glass libraries, bibliographic data, a remote access system to information and technical resources of telescopes etc.), and providing transparent access for scientific and educational purposes to the distributed information and data services that comprise its content. Another goal of the RVO is to provide Russian astronomers with on-line access to the rich volumes of data and metadata that have been, and will continue to be, produced by astronomical survey projects. Centre for Astronomical Data (CAD), among other Russian institutions, has had the greatest experience in collecting and distributing astronomical data for more than 20 years. Some hundreds of catalogs and journal tables are currently available from the CAD repository. More recently, mirrors of main astronomical data resources (VizieR, ADS, etc) are now maintained in CAD. Besides, CAD accumulates and makes available for the astronomical community information on principal Russian astronomical resources.

Dluzhnevskaya, O. B.; Malkov, O. Yu.; Kilpio, A. A.; Kilpio, E. Yu.; Kovaleva, D. A.; Sat, L. A.

411

Intelligent Virtual Environments  

NSDL National Science Digital Library

The research goals of the British-based lab, Intelligent Virtual Environments, of the University of Teesside are to develop "new models of interactivity based on Artificial Intelligence techniques." The website contains access to current projects, past and completed projects, technologies, as well as all publications and a tool to search those publications. Visitors can view the more than two dozen articles, going all the way back to 2000 on the subject of artificial intelligence techniques. On the menu to the left-hand side of the page are the links to the lab's current projects "IRIS", "CALLAS" and "COMPANIONS", and to "ALTERNE", "BARDS" and "CHARBIS", which are the lab's past and completed projects. Visitors especially shouldn't miss learning about the "COMPANIONS" project, which will be a virtual conversation companion in the near future. Watch the "Companions Movie" and check out the "Health and Fitness Companion" and "Senior Companion" demonstrators on the COMPANIONS homepage. There is also a Companions blog, for those interested in reading and responding to various topics related to this personalized type of artificial intelligence.

2009-06-25

412

Intelligent Virtual Environments  

NSDL National Science Digital Library

The research goals of the British-based lab, Intelligent Virtual Environments, of the University of Teesside are to develop "new models of interactivity based on Artificial Intelligence techniques." The website contains access to current projects, past and completed projects, technologies, as well as all publications and a tool to search those publications. Visitors can view the more than two dozen articles, going all the way back to 2000 on the subject of artificial intelligence techniques. On the menu to the left-hand side of the page are the links to the lab's current projects "IRIS", "CALLAS" and "COMPANIONS", and to "ALTERNE", "BARDS" and "CHARBIS", which are the lab's past and completed projects. Visitors especially shouldn't miss learning about the "COMPANIONS" project, which will be a virtual conversation companion in the near future. Watch the "Companions Movie" and check out the "Health and Fitness Companion" and "Senior Companion" demonstrators on the COMPANIONS homepage. There is also a Companions blog, for those interested in reading and responding to various topics related to this personalized type of artificial intelligence.

413

Virtually assisted optical colonoscopy  

NASA Astrophysics Data System (ADS)

We present a set of tools used to enhance the optical colonoscopy procedure in a novel manner with the aim of improving both the accuracy and efficiency of this procedure. In order to better present the colon information to the gastroenterologist performing a conventional (optical) colonoscopy, we undistort the radial distortion of the fisheye view of the colonoscope. The radial distortion is modeled with a function that converts the fisheye view to the perspective view, where the shape and size of polyps can be more readily observed. The conversion, accelerated on the graphics processing unit and running in real-time, calculates the corresponding position in the fisheye view of each pixel on the perspective image. We also merge our previous work in computer-aided polyp detection for virtual colonoscopy into the optical colonoscopy environment. The physical colonoscope path in the optical colonoscopy is approximated with the hugging corner shortest path, which is correlated with the centerline in the virtual colonoscopy. With the estimated distance that the colonoscope has been inserted, we are able to provide the gastroenterologist with visual cues along the observation path as to the location of possible polyps found by the detection process. In order to present the information to the gastroenterologist in a non-intrusive manner, we have developed a friendly user interface to enhance the optical colonoscopy without being cumbersome, distracting, or resulting in a more lackadaisical inspection by the gastroenterologist.

Marino, Joseph; Qiu, Feng; Kaufman, Arie

2008-04-01

414

Virtual playground: architectures for a shared virtual world  

Microsoft Academic Search

This paper describes a shared virtual worldwith four key goals: a reasonable economicmodel; low latency for world synchronization;a hospitable environment for users; andaffordances for social interaction. The firstgoal is supported by examining economicissues related to the design of commerciallyviable 3D virtual environments includingissues such as allowing use of currentlydeveloped Web based content. The secondgoal is supported by underlying networksupport that

Paul Schwartz; Lauren Bricker; Bruce Campbell; Thomas A. Furness; Kori Inkpen; Lydia Matheson; Nobutatsu Nakamura; Li-Sheng Shen; Susan Tanney; Shihming Yen

1998-01-01

415

Colon Cancer: Virtual Detection  

NSDL National Science Digital Library

Colon cancer is both the second most pervasive cancer to attack humans and one of the most preventable. One of the sad reasons for its prevalence has little to do with genes, diet, or overall health. Instead, it is the social stigma of the colon and rectum and the associated test --the colonoscopy -- which drives this cancer to the top of the list of killers. As with many cancer types, colon and rectal cancer is best treated in the early stages. And, when done so, the success of treatment is exponentially greater than dealing with it later on. While the typical test, the colonoscopy, is reliable, safe, and relatively easy, it still requires temporary sedation of the patient and the insertion of a camera through the large intestines. While the patient is sleepy and relaxed due to the sedation, and the procedure is reliably painless, the very thought of the proceture has kept many away. Now, with the advent of amazing virtual imaging technology, a virtual colonoscopy can be performed in seconds without sedation, and without the insertion of a camera. While there are pros and cons to each -- namely that by using the old method, any growths can be removed by the colonoscope immediately -- this may be the answer for crossing the formally highest hurdle: simply getting people in the door for testing. The several sites below offer a look at this new technology. Teachers will hopefully value not only the descriptive sites, but also the link to a related lesson plan.The first link leads to a segment from PBS' Newshour and offers a very good introduction to the topic. The link leads to your choice of the transcript, audio, or video of the interview conducted by Margaret Warner with Dr. Perry Pickhardt, radiologist at the University of Wisconsin -- Madison and co-director of a recent virtual colonoscopy study found in the New England Journal of Medicine and the object of a lot of buzz in the medical world. The second site leads to the University of Wisconsin's press release on the study's findings and the technology itself. The third site, while a bit technical for many readers, takes you to the New England Journal of Medicine website and the actual report produced by Dr. Pickhardt and his colleagues on their findings related to virtual colonoscopy. The fourth link leads the foremost cancer information center sponsored by the U.S. government, the National Cancer Institute and its web home for Colon and Rectal cancer. This is a great site to obtain both general and specific information related to the disease and the various treatments. The next link leads an exceptionally well produced series of reports by a Madison (Wisconsin) area television station, WISC. Its web home, channel3000.com, offers this site which gives a good report of virtual colonoscopy as well as many links to additional information. Finally, teachers, the last link leads back to PBS.org and a great lesson that asks students (grades 6-8) to think about this topic from its scientific point of view.

416

Microscopes and Cell Structures Unit  

NSDL National Science Digital Library

In this unit students learn to use the microscope and use it as a valuable tool to explore the world around them. The exploration provides an entry point into learning about cells. Additional activities teach about cell structures and processes. This unit covers most of the Oakland and California standards related to Cell Biology. The unit is organized into three sections. The first is a series of lessons intended to teach students how to use microscopes. The second corresponds to chapter 2 of the textbook and introduces students to the cell and its structure. The third relates to cell processes.

Cheung, Caleb; Dinell, Malia; Fukunaga, Stan; Grimes, Angela

2002-01-01

417

Advanced Microscopic Integrated Thermocouple Arrays  

NASA Technical Reports Server (NTRS)

The purpose of this research is to develop and refine a technique for making microscopic thermocouple arrays for use in measuring the temperature gradient across a solid-liquid interface during the solidification process. Current thermocouple technology does not allow for real-time measurements across the interface due to the prohibitive size of available thermocouples. Microscopic thermocouple arrays will offer a much greater accuracy and resolution of temperature measurements across the solid-liquid interface which will lead to a better characterization of the solidification process and interface reaction which affect the properties of the resulting material.

Pettigrew, Penny J.

1999-01-01

418

Microscopic aspects of the IBA  

NASA Astrophysics Data System (ADS)

The current status of efforts to derive the Interacting Boson Model (IBM) from the microscopic Shell Model is described. Although several boson mapping procedures presently exist, only the procedure of Otsuka, Arima and Iachello (OAI) is discussed in detail. The IBM bosons are assumed to be correlated pairs of identical nucleons of definite generalized seniority and angular momentum. The steps, which must be implemented in the OAI procedure in order for it to be considered a truly microscopic theory of the IBM, are then described. Using this procedure, we present results of typical calculations for the IBM-2 parameter X v , as an illustration.

Barrett, Bruce R.; Pittel, Stuart; Duval, Philip D.

1983-03-01

419

Microscopic Materials on a Magnet  

NASA Technical Reports Server (NTRS)

These images show a comparison of the weak magnet OM7 from the Optical Microscope on NASA's Phoenix Mars Lander before (left) and after (right) soil deposition.

The microscope took the left image during Phoenix's Sol 15 (June 10, 2008) and the right image during Sol 21 (Jun 16, 2008).

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

420

Care and Feeding of the Compound Microscope  

NSDL National Science Digital Library

This lab activity from the Biotechnology Alliance for Suncoast Biology Educators is intended to demonstrate appropriate use of a microscope. It covers the basic care and operation of a compound light microscope. The lesson includes information on how a compound microscope works, a diagram of its parts, tips for usage, a practice activity, and a checklist for putting the microscope away.

Keirle, Matt

2012-07-10

421

An almost simple counterexample to microscopic inversibility  

Microsoft Academic Search

The author adopts definitions for 'reciprocity', 'microscopic inversibility' (usually known as 'microscopic reversibility') and 'detailed balance' in terms of the S matrix. He notes several situations for which microscopic inversibility is obeyed and provide an explicit example for which is not. The validity of microscopic inversibility may depend on the choice of basis. He discusses the implications of these results

J. Berger

1990-01-01

422

Enhanced virtual microscopy for collaborative education  

PubMed Central

Background Curricular reform efforts and a desire to use novel educational strategies that foster student collaboration are challenging the traditional microscope-based teaching of histology. Computer-based histology teaching tools and Virtual Microscopes (VM), computer-based digital slide viewers, have been shown to be effective and efficient educational strategies. We developed an open-source VM system based on the Google Maps engine to transform our histology education and introduce new teaching methods. This VM allows students and faculty to collaboratively create content, annotate slides with markers, and it is enhanced with social networking features to give the community of learners more control over the system. Results We currently have 1,037 slides in our VM system comprised of 39,386,941 individual JPEG files that take up 349 gigabytes of server storage space. Of those slides 682 are for general teaching and available to our students and the public; the remaining 355 slides are used for practical exams and have restricted access. The system has seen extensive use with 289,352 unique slide views to date. Students viewed an average of 56.3 slides per month during the histology course and accessed the system at all hours of the day. Of the 621 annotations added to 126 slides 26.2% were added by faculty and 73.8% by students. The use of the VM system reduced the amount of time faculty spent administering the course by 210 hours, but did not reduce the number of laboratory sessions or the number of required faculty. Laboratory sessions were reduced from three hours to two hours each due to the efficiencies in the workflow of the VM system. Conclusions Our virtual microscope system has been an effective solution to the challenges facing traditional histopathology laboratories and the novel needs of our revised curriculum. The web-based system allowed us to empower learners to have greater control over their content, as well as the ability to work together in collaborative groups. The VM system saved faculty time and there was no significant difference in student performance on an identical practical exam before and after its adoption. We have made the source code of our VM freely available and encourage use of the publically available slides on our website.

2011-01-01

423

Integration of Avatars and Autonomous Virtual Humans in Networked Virtual Environments  

Microsoft Academic Search

In this paper, we survey problems and solutions for inserting virtual humans in Networked Virtual Environments. Using virtual humans as participant embodiment increases the collaboration in Networked Virtual Environments, as it provides a direct relationship between how we interact with the real world and the virtual world representation. We show the differences between avatars and autononous Virtual Humans in terms

Tolga K. Capin; Igor Sunday Pandzic; Nadia Magnenat Thalmann; Daniel Thalmann

424

Petrology and reservoir paragenesis in the Sussex 'B' sandstone of the upper Cretaceous Cody Shale, House Creek and Porcupine Fields, Powder River Basin, Wyoming  

SciTech Connect

Using petrologic and sedimentologic studies, the paper characterizes the influence of sedimentologic and petrologic variations on reservoir heterogeneity in the Sussex 'B' sandstone in the House Creek and Porcupine fields, Powder River Basin, Wyoming. Effects of authigenic minerals on reservoir properties are described in detail for selected inter-ridge and ridge facies sandstones.

Higley, D.K.

1991-05-03

425

Aboriginal Studies WWW Virtual Library  

NSDL National Science Digital Library

The Aboriginal Studies WWW Virtual Library has been now added to the other four WWW Virtual Library systems (Asian Studies, Buddhist Studies, Demography & Population Studies, and Social Sciences) developed and maintained by the Research Schools of Social Sciences & Pacific and Asian Studies at the Australian National University, Canberra.

426

The Power of Virtual Coaching  

ERIC Educational Resources Information Center

Amid budget cuts in U.S. public schools, the spotlight is on how to make less effective teachers more effective--fast. The authors describe virtual coaching--in which a coach interacts electronically with a teacher as a lesson unfolds--as a promising way to help teachers with weak teaching skills. Virtual coaching uses online and mobile technology…

Rock, Marcia L.; Zigmond, Naomi P.; Gregg, Madeleine; Gable, Robert A.

2011-01-01

427

Virtual Communities in Health Care  

Microsoft Academic Search

A virtual community is a social entity involving several individuals who relate to one another by the use of a specific communication technology that bridges geographic distance. Traditional communities are determined by factors such as geographic proximity, organizational structures or activities shared by the members of the community. The concept “virtual” implies properties that unlike these of a traditional community

George Demiris

428

Creating the Virtual Middle Ground.  

ERIC Educational Resources Information Center

Contemporary culture exhibits an increasingly polarized spectrum of attitudes toward virtualization: those who want photorealism and those who seek sheer fantasy. This author describes "Virtual Realism," his strategy for balancing the two social forces. His students at California's Art Center College of Design are putting it to the test.…

Heim, Michael

1998-01-01

429

The Web and Virtual Schools  

ERIC Educational Resources Information Center

This paper focuses on the role of government in the growth of Web-based virtual schools. First, it describes the current evolving situation. It then discusses ways in which U.S. federal, state, and local governments have developed virtual schools, and presents some information about international initiatives in this area. It also identifies…

Schrum, Lynne

2005-01-01

430

Dedicated online virtual reference instruction.  

PubMed

To facilitate nursing students' information literacy skills and enhance traditional library user services, academic librarians have developed synchronous (real-time) online virtual reference instruction in nursing research classes. The authors discuss collaborative efforts of nursing and library faculty in planning, implementing, and evaluating a discipline-specific virtual reference pilot program. PMID:16292145

Guillot, Ladonna; Stahr, Beth; Plaisance, Louise

2005-01-01

431

Virtual child pornography and utilitarianism  

Microsoft Academic Search

The most common argument against child pornography is that children are harmed in the process of producing it. This is the argument from abusive production. However, it does not apply to ‘virtual’ child pornography, i.e. child pornography produced using computer technology without involving real children. Autilitarian who wishes to condemn virtual child pornography cannot appeal to the argument from abusive

Per Sandin

2004-01-01

432

Virtual cathode microwave devices -- Basics  

SciTech Connect

Unlike a conventional microwave tube, a virtual-cathode device operates above the space-charge limit where the depth of the space-charge potential can cause electron reflection. The region associated with this electron reflection is referred to as a virtual cathode. Microwaves can be generated through oscillations in the position of the virtual cathode and through the bunching of electrons trapped in a potential well between the real and virtual cathodes. These two mechanisms are competitive. There are three basic classes of virtual cathode devices: (1) reflex triode; (2) reditron and side-shoot vircator; and (3) reflex diode or vircator. The reflex diode is the highest power virtual-cathode device. For the reflex diode the energy exchange between the beam and electromagnetic wave occurs in both the axial and radial directions. In some designs the oscillating-virtual-cathode frequency exceeds the reflexing-electron frequency exceeds the oscillating-virtual-cathode frequency. For the flex diode a periodic disruption in magnetic insulation can modulate the high- frequency microwave power. Overall, particle-in-cell simulation predictions and axial reflex diode experiments are in good agreement. Although frequency stability and phase locking of the reflex diode have been demonstrated, little progress has been made in efficiency enhancement. 58 refs., 11 figs.

Thode, L.E.; Snell, C.M.

1991-01-01

433

Ethical harm in virtual communities  

Microsoft Academic Search

This article analyzes under which conditions ethical relevant avatar harm occurs in virtual worlds. The authors argue that this is most likely to occur when there are some norms of acceptable behavior in a virtual world and when players see avatars as constitutive to their identity. Other than online environments characterized by a ‘caveat emptor’ approach, Second Life is governed

Bastiaan Vanacker; Don Heider

2012-01-01

434

Virtual Ed. Faces Sharp Criticism  

ERIC Educational Resources Information Center

It's been a rough time for the image of K-12 virtual education. Studies in Colorado and Minnesota have suggested that full-time online students are struggling to match the achievement levels of their peers in brick-and-mortar schools. Articles in "The New York Times" questioned not only the academic results for students in virtual schools, but…

Quillen, Ian

2011-01-01

435

Real-time virtual humans  

Microsoft Academic Search

The last few years have seen great maturation in the com- putation speed and control methods needed to portray 3D virtual humans suitable for real interactive applications. We first describe the state of the art, then focus on the particular approach taken at the University of Pennsylvania with the Jack system. Various aspects of real-time virtual humans are considered, such

Norman I. Badler

1997-01-01

436

Knowledge Navigation for Virtual Vehicles  

NASA Technical Reports Server (NTRS)

A virtual vehicle is a digital model of the knowledge surrounding a potentially real vehicle. Knowledge consists not only of the tangible information, such as CAD, but also what is known about the knowledge - its metadata. This paper is an overview of technologies relevant to building a virtual vehicle, and an assessment of how to bring those technologies together.

Gomez, Julian E.

2004-01-01

437

Toward a virtual politicking model  

Microsoft Academic Search

Virtual politicking is the use of email to support organizational politics. Surprisingly, despite the proliferation of email, its role in enabling political maneuvering is just starting to be acknowledged by managers and information systems practitioners. The Virtual Politicking Model detailed in this article synthesizes data from a series of real-life incidents in which email was used for political manipulation within

Celia T. Romm; Nava Pliskin

1997-01-01

438

The Geography of Virtual Questioning  

ERIC Educational Resources Information Center

This article explores the geography of virtual questioning by using geographic information systems to study activity within the Florida Electronic Library "Ask a Librarian" collaborative chat service. Researchers mapped participating libraries throughout the state of Florida that served as virtual "entry portals" for users as they asked questions…

Mon, Lorri; Bishop, Bradley Wade; McClure, Charles R.; McGilvray, Jessica; Most, Linda; Milas, Theodore Patrick; Snead, John T.

2009-01-01

439

Telemedicine, virtual reality, and surgery  

NASA Technical Reports Server (NTRS)

Two types of synthetic experience are covered: virtual reality (VR) and surgery, and telemedicine. The topics are presented in viewgraph form and include the following: geometric models; physiological sensors; surgical applications; virtual cadaver; VR surgical simulation; telesurgery; VR Surgical Trainer; abdominal surgery pilot study; advanced abdominal simulator; examples of telemedicine; and telemedicine spacebridge.

Mccormack, Percival D.; Charles, Steve

1994-01-01

440

The Virtual Model Repository (VMR)  

NASA Astrophysics Data System (ADS)

The Virtual Model Repository (VMR) is a new Virtual Observatory (VxO) that helps to integrate computational model results with observational data by facilitating visualization, data/model comparisons, and independent interpretation of model result. In addition, it facilitates browsing of satellite data and model results for interesting time periods.

de Zeeuw, D. L.; Ridley, A. J.; Bashkirov, V.

2010-09-01

441

Learning Experience with Virtual Worlds  

ERIC Educational Resources Information Center

Virtual worlds create a new opportunity to enrich the educational experience through media-rich immersive learning. Virtual worlds have gained notoriety in games such as World of Warcraft (WoW), which has become the most successful online game ever, and in "general purpose" worlds, such as Second Life (SL), whose participation levels (more than 10…

Wagner, Christian

2008-01-01

442

Virtual Enterprise and Corporate Memory  

Microsoft Academic Search

In Concurrent Engineering, several designers in different fields and from different enterprise col- laborate to build a product. This organization is a temporal organizational structure, called virtual enterprise. In fact, once the project is realized, the virtual enterprise is dissolved, so the deal in such organization is to keep the volatile knowledge. In this paper, we propose a guide to

Myriam Ribière; Nada Matta

1998-01-01

443

CPVM: customizable portable virtual machines  

Microsoft Academic Search

We present our experiences with a customizable portable virtual machine (CPVM) environment that makes it possible for students and professors to develop a customized, fully loaded, fully functional virtual machine that they can run on any computer that has a USB port or an ftp client without compromising the host. We also make available to students and faculty a copy

Ralph Butler; Chrisila C. Pettey; Zach Lowry

2006-01-01

444

Visualization and holography: real virtuality  

Microsoft Academic Search

This work focuses on the attempt to establish an analogue and contiguity between visualization and holography. The majority of methods for processing and analysis data work in the virtual space with its virtual images and shapes. Scientific visualization is an extraction of the significant information from the data space and its presentation as a visual shapes, applicable to the visual

Sergey V. Matveyev; Stanislav Klimenko

2002-01-01

445

Cloud Computing in Virtual Environments  

Microsoft Academic Search

In this paper we present the basis of a new middleware service that provisions clouds for virtual organizations (VOs).This service makes use of a virtual environment's inherent ability to render objects to represent clouds with real clouds. These clouds are created on demand by avatars and tagged to provide a rudimentary semantic that can be used for searching. Clouds are

Kristen Hardwick; John Fisher; Ben Sterrett; Christine Minor; Sebastien Goasguen

2009-01-01

446

Towards a Reactive Virtual Trainer  

Microsoft Academic Search

A Reactive Virtual Trainer (RVT) is an Intelligent Virtual Agent (IVA) capable of presenting physical exercises that are to be performed by a human, monitoring the user and providing feedback at different levels. Depend- ing on the motivation and the application context, the exercises may be general ones of fitness to improve the user's physical condition, special exercises to be

Zsófia Ruttkay; Job Zwiers; Herwin Van Welbergen; Dennis Reidsma; J. Gratch; M. Young; R. Aylett; D. Ballin; P. Olivier

2006-01-01

447

Developing Trust in Virtual Teams  

ERIC Educational Resources Information Center

Rapid globalization, advances in technology, flatter organizational structures, synergistic cooperation among firms, and a shift to knowledge work environments have led to the increasing use of virtual teams in organizations. Selecting, training, and socializing employees in virtual teamwork has therefore become an important human resource…

Germain, Marie-Line

2011-01-01

448

Virtual Enterprises and Vocational Training.  

ERIC Educational Resources Information Center

Characteristics of virtual enterprises (client oriented, temporary working organizations that dissolve after solving specific problems, extensive technological applications) can be applied to vocational training. Virtual learning centers can provide web-based training intraorganizationally and interorganizationally via intranets and extranets. (SK)

Kreber, Stefan

2001-01-01

449

A versatile multipurpose scanning probe microscope  

Microsoft Academic Search

Summary A combined scanning probe microscope has been developed that allows simultaneous operation as a non-contact\\/tapping mode atomic force microscope, a scattering near-field optical microscope, and a scanning tunnelling microscope on con- ductive samples. The instrument is based on a commercial optical microscope. It operates with etched tungsten tips and exploits a tuning fork detection system for tip\\/sample distance control.

E. Cefali; S. Patane; P. G. Gucciardi; M. Labardi; M. Allegrini

2003-01-01

450

Virtual Stationary Automata for Mobile Networks.  

National Technical Information Service (NTIS)

We define a programming abstraction for mobile networks called the Virtual Stationary Automata programming layer, consisting of real mobile clients, virtual timed I/O automata called virtual stationary automata (VSAs), and a communication service connecti...

S. Dolev S. Gilbert L. Lahiani N. Lynch T. Nolte

2005-01-01

451

Toolmaker's Microscope With Video Monitor  

NASA Technical Reports Server (NTRS)

Display accessories increase resolution and flexibility of use. Toolmaker's microscope equipped with video monitor, auxiliary lighting, and high-resolution readout devices enables noncontacting measurements of tiny slots, indentations, and similar features on parts. Measures places difficult or impossible to reach by mechanical means.

Ahmed, Arif S.

1988-01-01

452

Compact Microscope Imaging System Developed.  

National Technical Information Service (NTIS)

The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. The CMIS can be used in situ with a minimum amount of user intervention. This system, which was d...

M. McDowell

2001-01-01

453

Be a Scanning Probe Microscope  

NSDL National Science Digital Library

In this activity, learners investigate Scanning Probe Microscopes (SPM) and then work in teams using a pencil to explore and identify the shape of objects they cannot see, just as SPMs do at the nano level. Learners draw what their mind "sees" on paper, compare their results with other teams, and share observations with their group.

Ieee

2013-02-25

454

Switch on Micro*scope!  

ERIC Educational Resources Information Center

Scientists at the Marine Biological Laboratory in Woods Hole, Massachusetts, have created micro*scope, a free, searchable knowledge environment for exploring the microbial world. Microbiology can easily be incorporated into the curriculum, because microbial communities are easy to access. Organisms grow quickly, making certain arrays of…

Roland, Sarah; Bahr, Michele; Olendzenski, Lorraine; Patterson, David J.

2005-01-01

455

Nature Study with the Microscope.  

ERIC Educational Resources Information Center

Identifies specific instruction difficulties, potential problems, solutions, and activities for successful use of microscopes in the classroom. Procedures are outlined for guiding students in creating their own slides with monocotyledon and dicotyledon stems, fern spores, stomata, lichens, and red onions. (MCO)

Sollberger, Dwight E.

1991-01-01

456

Microscopic Theory of Irreversible Processes  

Microsoft Academic Search

The microscopic theory of irreversible processes that we developed is summarized and illustrated, using as a simple example the Friedrichs model. Our approach combines the Poincare's point of view (dynamical interpretation of irreversibility) with the Gibbs-Einstein ensemble point of view. It essentially consists in a nonunitary transformation theory based on the symmetry properties of the Liouville equation and dealing with

I. Prigogine; F. Mayne; C. George; M. de Haan

1977-01-01

457

Microscope Observations of TNT Crystallisation.  

National Technical Information Service (NTIS)

The growth and grain structure of cast TNT have been observed in thin films using a polarishing microscope. Growth rate of solid into liquid is found to increase with undercooling from the melting point at 80C to a peak at about 30C. Growth rate at lower ...

B. W. Thorpe M. C. Chick W. Connick

1970-01-01

458

Absolute focus lock for microscopes  

NASA Technical Reports Server (NTRS)

Mechanism absolutely immobilizes microscope stage at a preset focus, preserving focus indefinitely. The lock is a second-class lever consisting of a straight body having a fulcrum with a cylindrical bearing surface at one end and a thumbscrew at the other end.

Cone, C. D., Jr.; Loop, R. W.; Tongier, M., Jr.

1970-01-01

459

Chasing Meteors With a Microscope.  

ERIC Educational Resources Information Center

Describes types of meteors and micrometeorites that enter the Earth's atmosphere. Presents an activity where students collect micrometeorites with a strip of tape in an undisturbed outdoor area. After 24 hours, they examine the tape by sandwiching it between 2 glass slides and view through a microscope at 100X. (PR)

Jones, Richard C.

1993-01-01

460

The microscope in the hatchery  

USGS Publications Warehouse

Without the aid of the microscope, it is safe to assume that fish Culture would now stand exactly where it did seventy-five years ago when methods of artificial fertilization were first applied. It is also safe to assume that the results from fish culture would be as unsatisfactory as they were at that time when the fishery resources were steadily declining in spite of the increased liberation of advanced fry from the hatcheries. During the past few years the microscope has saved millions of fish in our hatcheries which otherwise would have been sacrificed to disease. Moreover, the microscope has permitted all of the recent work in selective breeding, nutritional requirements, and disease control. This work marks most of the progress fish culture has made during the past twenty-five years. This progress forms the first definite step away from the old system of hatching and distributing fish, a system which was founded by the ancient Chinese. The microscope has been the key which enabled the fish culturist to solve the riddle of success which has stood, unanswered, for 2,500 years.

Fish, F. F.

1935-01-01

461

Virtual Landscapes of Texas  

NSDL National Science Digital Library

Whether real or virtual, Texas has a great deal of landscape. The people at the library at the University of Texas at Austin know this quite well, and they have put together this delightful online archive of public domain documents that deal with various landscapes throughout the state. As the introductory essay on the site notes, "This suite of public domain documents was selected as a foundation to preserve and to widen access to early writings on the geology of Texas." Visitors can use the online search engine to look for specific materials, or they can peruse them via an alphabetical listing. All told, there are well over sixty full-text documents here, including geological study reports from the late 19th century, drought surveys, and extended treatises on the effectiveness of various road-building materials.

462

Automated virtual colonoscopy  

NASA Astrophysics Data System (ADS)

Virtual colonscopy (VC) is a minimally invasive alternative to conventional fiberoptic endoscopy for colorectal cancer screening. The VC technique involves bowel cleansing, gas distension of the colon, spiral computed tomography (CT) scanning of a patient's abdomen and pelvis, and visual analysis of multiplanar 2D and 3D images created from the spiral CT data. Despite the ability of interactive computer graphics to assist a physician in visualizing 3D models of the colon, a correct diagnosis hinges upon a physician's ability to properly identify small and sometimes subtle polyps or masses within hundreds of multiplanar and 3D images. Human visual analysis is time-consuming, tedious, and often prone to error of interpretation.We have addressed the problem of visual analysis by creating a software system that automatically highlights potential lesions in the 2D and 3D images in order to expedite a physician's interpretation of the colon data.

Hunt, Gordon W.; Hemler, Paul F.; Vining, David J.

1997-05-01

463

The Jewish Virtual Library  

NSDL National Science Digital Library

The Jewish Virtual Library website is a project designed and maintained by the American-Israeli Cooperative Enterprise (AICE), which was established as a nonprofit organization in 1993. From the homepage, visitors are presented with a series of topical areas such as "History", "The Holocaust", "Politics", and "Travel", along eight other additional areas. The "Reference" area is quite helpful, as it contains a number of helpful fact sheets and a timeline for the history of Judaism. The "Israel & The States" section will also interest many visitors, as it contains detailed information about the nature of the relationship between each US state and the nation of Israel. The site is rounded out by a glossary of relevant terms, a selection of maps of the region, and a list of suggested readings.

464

The virtual temporal bone.  

PubMed

The human temporal bone is a 3-dimensionally complex portion of the skull that contains delicate and vital anatomic structures imbedded within dense bone. Current teaching tools have proven to be only marginally adequate for the needs of the aspiring otologic surgeon in learning this anatomy. A variety of image processing and reconstruction techniques were used to reconstruct an anatomically accurate 3-dimensional model of the human temporal bone from serial histologic sections. Using CAVE technology, the model can be manipulated in a stereoscopic virtual environment so that it can be studied from any viewpoint, greatly simplifying the task of learning this anatomy. Applications in surgical planning and Internet based teaching are discussed. PMID:10180566

Mason, T P; Applebaum, E L; Rasmussen, M; Millman, A; Evenhouse, R; Panko, W

1998-01-01

465

The virtual doctor visit.  

PubMed

American healthcare is changing at a rapid pace. No one knows for certain what the impact will be for the Affordable Care Act. What we do know is that changes are going to take place, and the physician of the future needs to be ready to embrace changes in the way healthcare is conducted. One of those changes certain to occur is that patients will have a significant amount of their medical care delivered using the technology of the Internet and not the traditional in-office visit where the doctor and patient are eyeball-to-eyeball. This article will describe the virtual office visit and the benefits to both the patient and physician. PMID:24765740

Rosenzweig, Rich; Baum, Neil

2013-01-01

466

Virtual Anaesthesia Textbook  

NSDL National Science Digital Library

Ten years ago, Chris Thompson conceived of an idea for a high-quality, collaborative, online textbook dedicated to the field of anesthesia. Soon afterwards, the project was started, and with the assistance of numerous practitioners and researchers, this virtual textbook was created. While the site's use of frames can be a bit distracting, the organization of the material here is easy enough to understand and navigate. Along the left-hand side of the homepage, there are several primary sections, including "Professional Issues", "Basic Sciences", and "Patient Care". Within each section, users will find a mix of content created specifically for this site, along with links that will redirect them to other external sites. The "Patient Care" area is quite good, as it gets down to the nuts and bolts of such practical matters as positioning the patient, dealing with post-operative pain management, and intubations.

467

MSN Virtual Earth  

NSDL National Science Digital Library

Geographers, urban planners, and those with a penchant for the spatial always enjoy knowing as much as they can about a given locale, and they especially enjoy knowing about spatial relationships in a given locale. For those aforementioned persons, MSN's Virtual Earth website will be one that is quite worthy of numerous visits. Drawing on detailed aerial photographs of the United States, visitors can look at photographs of their home, their business, or a local sports stadium. Visitors can also type in city names, and zoom in on various features at their leisure. A real treat is offered by the tabs feature, which allows visitors to look for local businesses, such as book stores and pharmacies in any given locale. A "scratch pad" also keeps track of recently visited destinations as well. All in all, this site can be both quite helpful and, at times, somewhat addictive.

468

Virtual World Astrosociology  

NASA Astrophysics Data System (ADS)

This essay introduces the opportunity for theory development and even empirical research on some aspects of astrosociology through today's online virtual worlds. The examples covered present life on other planets or in space itself, in a manner that can be experienced by the user and where the user's reactions may simulate to some degree future human behavior in real extraterrestrial environments: Tabula Rasa, Anarchy Online, Entropia Universe, EVE Online, StarCraft and World of Warcraft. Ethnographic exploration of these computerized environments raises many questions about the social science both of space exploration and of direct contact with extraterrestrials. The views expressed in this essay do not necessarily represent the views of the National Science Foundation or the United States.

Bainbridge, William Sims

2010-01-01

469

Georgia's Virtual Vault  

NSDL National Science Digital Library

Peering into the world of Georgia's past has become a little easier with the Georgia Archives. Created by the Georgia Secretary of State's Office, the Virtual Vault provides access to historic Georgia manuscripts, photographs, and maps. The R.J. Taylor, Jr. Foundation provided funding for this endeavor, and visitors can look over the topical headings on the left-hand side of the page to get started. First-time visitors should look at the Lamar Q. Ball Photograph collection, which documents military and civilian life in Georgia during World War II. Visitors can also use the document management tools here to create their own collections of images for later use. The other nineteen collections here include Georgia death certificates, historic postcards, colonial will books, and district plats.

470

Virtual Presentation Assistant  

NSDL National Science Digital Library

In these tumultuous times, it seems like more and more people want to win friends and influence people. Of course, there are enterprising souls who would attempt to sell you their insights into the art of oratory and such, but this website gives away such prized material at no cost to you, gentle browser. Virtual Presentation Assistant is an online tutorial dedicated to the art and skill of public speaking, and the site is maintained by the dedicated staff of the communication studies department at the University of Kansas. Simple in its design, the site covers such topics as selecting an appropriate theme for a speech, how to research said speech, and supporting your primary points. If all of this material doesn’t whet one’s appetite, the site also contains a selection of links to other sites that deal with the subject at hand.

471

Virtual Open Heart Surgery  

NSDL National Science Digital Library

How does open heart surgery work? Without taking the time to get a formal medical degree, it can be quite hard to find out first-hand. Fortunately, this site from the Australian Broadcasting Company (ABC) takes you inside a virtual operating room to try your hand at performing this procedure. Visitors can look over the interactive Menu to first learn about the anatomy of this region of the body. It's a good place to start and users can proceed to look through the ten (simplified) steps to performing such a complicated operation. Along the way, visitors are given the opportunity to learn about the science behind each step and it's all quite fascinating. It's a great resource for budding scientists, medical professionals, and those who are generally curious about the human body.

472

Virtual Summer School  

NSDL National Science Digital Library

A Virtual Summer School is being run this month by The Human Cognition Research Laboratory at the UK's Open University. The summer school enables students of Cognitive Pscyhology to participate in group discussions and tutorials via Internet Videoconferencing, and to run experiments, conduct literature searches, undertake statistical analyses, and, of course, socialize and chit-chat, all without leaving their homes. The Human Cognition Research Laboratory undertakes a combination of basic and applied research in Artificial Intelligence (AI), Knowledge Engineering, Cognitive Science, and Human Computer Interaction (particularly program visualization). The long-term goal of this research is to understand the fundamental processes of cognition, and to exploit this understanding where appropriate in the design of complex software systems. Also have a look at the experimental Open University Home Page.

473

Chem1 Virtual Textbook  

NSDL National Science Digital Library

Chemistry serves as a fundamental discipline for those who will go on to careers in everything from medicine to nutrition and it is important for students of this science to have a wide range of resources at their disposal. One rather useful online resource is this virtual textbook for general chemistry created and updated by Professor Stephen Lower of Simon Fraser University. Visitors to the site can dive right in by reading an introduction titled "What is Chemistry all about, anyway?", and then proceed through a very well-structured set of chapters dedicated to the basics of atoms, equations, chemical energetics and other topics that would be typically covered in such a course. The site is rounded out by a good set of links to related interactive chemistry tutorials and exercises.

Lower, Stephen

474

Tracking Virtual Trajectories  

NASA Technical Reports Server (NTRS)

Current models of smooth pursuit eye movements assume that it is largely driven by retinal image motion. We tested this hypothesis by measuring pursuit of elliptical motion (3.2s, 0.9 Hz, 1.4 deg x 1.6 deg, 4 randomly interleaved phases) of either a small spot ("real" motion) or of a line-figure diamond viewed through apertures such that only the motion of four isolated oblique line segments was visible ("virtual" motion). Each segment moved sinusoidally along a linear trajectory yet subjects perceived a diamond moving along an elliptical path behind the aperture. We found, as expected, that real motion produced accurate tracking (N = 2) with mean gain (over horizontal and vertical) of 0.9, mean phase of -6 deg (lag), mean relative phase (H vs V) of 90 +/- 8 deg (RMS error). Virtual motion behind an X-shaped aperture (N= 4 with one naive) yielded a mean gain of 0.7, mean phase of -11 deg, mean relative phase of 87 +/- 15 deg. We also measured pursuit with the X-shaped aperture using a higher segment luminance which prevents the segments from being grouped into a coherently moving diamond while keeping the motion otherwise identical. In this incoherent case, the same four subjects no longer showed consistent elliptical tracking (RMS error in relative phase rose to 60 deg) suggesting that perceptual coherence is critical. Furthermore, to rule out tracking of the centroid, we also used vertical apertures so that all segment motion was vertical (N = 3). This stimulus still produced elliptical tracking (mean relative phase of 84 +/- 19 deg), albeit with a lower gain (0.6). These data show that humans can track moving objects reasonably accurately even when the trajectory can only be derived by spatial integration of motion signals. Models that merely seek to minimize retinal or local stimulus motion cannot explain these results.

Stone, Leland S.; Beutter, Brent R.; Loren