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1

A Virtual Petrological Microscope for All Apollo 11 Lunar Samples  

NASA Technical Reports Server (NTRS)

A means of viewing, over the Internet, polished thin sections of every rock in the Apollo lunar sample collections via software, duplicaing many of the functions of a petrological microscope, is described.

Pillnger, C. T.; Tindle, A. G.; Kelley, S. P.; Quick, K.; Scott, P.; Gibson, E. K.; Zeigler, R. A.

2014-01-01

2

Virtual Microscope  

NSDL National Science Digital Library

The Virtual Microscope project provides cost-free simulated scientific instrumentation for students and researchers worldwide as part of NASA's Virtual Laboratory initiative. This site supports and shares data from three instruments: a scanning electron microscope, a fluorescence light microscope, and an atomic force microscope. The automated data capture software is shared with users via a Java application that provides a simulation of the group's actual microscope interfaces. The magnification controls allow the user to explore any point of interest on the sample. Also included is a set of specimen annotation tools for teachers and learners. In addition to the datasets, the website provides training materials and animated tutorials that explore the basics of each imaging method. The Virtual Microscope is an open source project developed by the Imaging Technology Group, part of the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign.

2013-02-11

3

Virtual Microscope  

NSDL National Science Digital Library

This simulation allows students to learn in the same way they do on a real microscope and improve their actual lab experience. They will be able to see the outside of the microscope to examine the controls, and can also look through the microscope at a specimen. These views can be switched at any time, but a student will not see a specimen unless the proper steps are followed. Students view images of actual specimens and can adjust all microscope controls including the light switch, rheostat, magnification, stage position, oculars, coarse and fine focus, and iris diaphragm. The simulation is accompanied by a tutorial and an instructional video.

4

Virtual Microscope: Training  

NSDL National Science Digital Library

This web page, part of the Virtual Microscope Project, features interactive animations that illustrate the basics of imaging in the Scanning Electron Microscope (SEM), the Fluorescence Light Microscope (LM), and the Atomic Force Microscope (AFM). Also included are videos demonstrating how to prepare samples for each type of microscope. Don't miss the interviews with scientists who discuss career paths that utilize microscopy in both the public and private sectors. The Virtual Microscope provides cost-free simulated scientific instrumentation for students and researchers worldwide as part of NASA's Virtual Laboratory initiative. This site supports and shares data from all three instruments: SEM, LM, and AFM. Automated data capture software is shared with users via a Java application that provides a simulation of the group's actual microscope interfaces. The magnification controls allow the user to explore any point of interest on the sample and provides access to a robust set of specimen annotation tools.

2013-02-11

5

Virtual Compound Microscope  

NSDL National Science Digital Library

Virtual Microscopy is a very handy online tool to learn how to use a microscope. The creator developed this tool in response to student frustration in learning how to use microscopes. The virtual scope has all the same controls found on the real unit and the user can learn the parts of the microscope as well as how to adjust the different objectives, course and fine focus, and make light adjustments with the iris diaphragm. Of particular interest is the fact that the simulation shows actual microscope specimens, like onion root tip, so students can see what mitotic figures look like under the microscope without having to be expert users. Of course, a simulation does not take the place of using the actual microscope but can certainly shorten the time that it takes to learn how to use one, and lessen the amount of frustration for both student and teacher.

Ketcham, Robert; Kinney, Becky

2012-11-13

6

The Virtual Microscope  

NSDL National Science Digital Library

The work of pathologists is often limited by the supply of tissue samples and live specimens they have on hand. This paper addresses this problem by proposing the Virtual Microscope (VM), a software-based solution that digitally records images of magnified slides. In this manner, a scientist would only need to search a database of digital slides instead of hoping to find another slide of the required sample. The VM is created in such a way as to simulate a real microscope, allowing the user to change illumination levels, focus, and magnification factor. The authors describe the architecture and different configurations of the VM system, as well as addressing potential problems due to the massive amount of data required for a single digital slide.

Benyon, Michael P.; Catalyurek, Umit.; Chang, Chialin, 1966-.; Kure, Tahsin.; Saltz, Joel.; Sussman, Alan (Alan L.).

7

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

8

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

9

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

NASA Astrophysics Data System (ADS)

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 opportunity for enhancement and enrichment of laboratory experience in geoscience. The focus of petrological microscope study is not primarily related to learning facts but is concerned with learning how to discriminate and classify within the paradigms of the discipline. In this case, the recognition and measurement of key features in rock samples in hand specimen and thin section. Whilst undertaking the practical exercise of recognition and naming of rock samples students are really being required to develop an understanding of the rock cycle as a model representing the relationship between rock categories and the process of their formation. The problems of teaching with complex visual materials, in effect of teaching learners 'how to see' from the scientific perspective of a particular discipline, are quite general. It could reasonably be expected that lessons learnt from the implementation and detailed evaluation of the proposed web-based system will generalise to many other topics in science education. Thus we focussed on the thin section images rather than reproducing a system that resembled a physical microscope. The virtual petrological microscope developed for a course at the Open University UK enables student acquisition of skills such as mineral and rock recognition using a browser window to explore thin sections of rocks as if they were using a laboratory microscope. The microscope allows students to pan around the thin sections (held as 1GB files on a remote server); zoom in and out, change from plane polarised light to cross polarised light conditions, and study the changing mineral pleochroism and birefringence in rotating view 'hot spots'. The microscope also includes tools such as hyper-linked descriptive teaching text, labels on the slide, XY coordinates and measurement tools. The fully developed system is for individual users each accessing the slides via a browser window, but we are also developing mobile version and exploring a shared version which will allow students and tutors to collaborate at distance.

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

2009-12-01

10

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

11

Virtual Microscope: Scanning Electron Microscopy Basics  

NSDL National Science Digital Library

This is an interactive animation that illustrates the basics of imaging in the Scanning Electron Microscope (SEM). It displays images of the external and internal components of the microscope, then provides animations of the electron emission and capture processes. Finally, the tutorial discusses how the digital signal produced by the Secondary Electron Detector (SED) is converted into grayscale pixels on a computer screen. 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 Fluorescense Light Microscopy.

2013-02-11

12

Virtual microscopes in podiatric medical education.  

PubMed

In many medical schools, microscopes are being replaced as teaching tools by computers with software that emulates the use of a light microscope. This article chronicles the adoption of "virtual microscopes" by a podiatric medical school and presents the results of educational research on the effectiveness of this adoption in a histology course. If the trend toward virtual microscopy in education continues, many 21st-century physicians will not be trained to operate a light microscope. The replacement of old technologies by new is discussed. The fundamental question is whether all podiatric physicians should be trained in the use of a particular tool or only those who are likely to use it in their own practice. PMID:17114609

Becker, John H

2006-01-01

13

Virtual Microscope: Scanning Probe Microscopy Basics  

NSDL National Science Digital Library

This animated tutorial explores the basics of scanning probe microscopy (SPM), a branch of microscopy that forms images using a tiny physical probe to scan specimens. The advantage of SPM is that it can produce high resolution images of nanoscale samples and does not require a partial vacuum. This tutorial provides beginners with a very clear picture of how the probe tip interacts with a sample surface to produce 3-dimensional data about topography. The tutorial covers scanning tunneling, contact mode, and tapping mode. For additional background information on probe microscopy, we recommend: Introduction to AFM. 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

14

Virtual laboratory manual for microscopic anatomy.  

PubMed

Using digital technology, we have assembled a virtual laboratory manual (VLM) that is a Web-based copy of our traditional laboratory manual. The VLM is used to enhance traditional laboratory instruction in histology. For each reference in the VLM to either a histological slide or an electron micrograph (EM), hyperlinks are included that download digital images derived from the students' glass slide sets or scanned EMs. The VLM serves as an atlas of digital images for concurrent study of similar sections by light microscopy during laboratory sessions. In addition, students can review the images from the VLM at remote locations. We have encouraged continued use of light microscopes in laboratories by basing the majority of practical examination identifications on analysis of marked histological slides that require students to use their own microscopes. The VLM provides the convenience of a Web-based resource with high-quality images, yet allows retention of the many excellent traditional aspects of our course. An example of a VLM laboratory on epithelium is available online (http://users.von.uc.edu/michaeje/VLM-Epithelium/exLab4.pdf). PMID:15898084

Michaels, John E; Allred, Kelly; Bruns, Christina; Lim, Wan; Lowrie, D J; Hedgren, Wade

2005-05-01

15

Virtual microscope interface to high resolution histological images  

PubMed Central

The Hypertext atlas of Dermatopathology, the Atlas of Fetal and Neonatal Pathology and Hypertext atlas of Pathology (this one in Czech only) are available at . These atlases offer many clinical, macroscopic and microscopic images, together with short introductory texts. Most of the images are annotated and arrows pointing to the important parts of the image can be activated. The Virtual Microscope interface is used for the access to the histological images obtained in high resolution using automated microscope and image stitching, possibly in more focusing planes. Parts of the image prepared in advance are downloaded on demand to save the memory of the user's computer. The virtual microscope is programmed in JavaScript only, works in Firefox/Mozilla and MSIE browsers without need to install any additional software. PMID:18673498

Feit, Josef; Matyska, Ludek; Ulman, Vladimir; Hejtmanek, Lukas; Jedlickova, Hana; Jezova, Marta; Moulis, Mojmir; Feitova, Vera

2008-01-01

16

Microscopic computed tomography-based virtual histology of embryos.  

PubMed

Advances in imaging technologies and computational capabilities have made possible novel methods for phenotypic assessments and visualization of detailed anatomical structures of whole embryos. We recently reported a rapid and inexpensive technique for achieving high-resolution virtual histology for phenotyping assessment of mouse embryos (Johnson et al., PLoS Genet 2:e61, 2006). By en bloc staining in a solution of electron-dense osmium tetroxide followed by volumetric X-ray computed tomography, whole embryos can be imaged at isometric resolutions as high as 2.5 ?m, depending on the size of the specimen. The datasets generated by these techniques are compatible with state-of-the-art computational methods of organ pattern analysis. This method of Microscopic Computed Tomography (microCT)-based Virtual Histology of embryos allows one to rapidly and accurately phenotype transgenic embryos or to engage in developmental and reproductive toxicology studies of investigational drugs at better resolution, less time, and less expense than traditional histology, magnetic resonance microscopy, or the classical Wilson and Staples procedures. PMID:24318828

Prajapati, Suresh I; Rodriguez, David R; Keller, Charles

2014-01-01

17

Automatic Camera-Based Microscope Calibration for a Telemicromanipulation System Using a Virtual Pattern  

Microsoft Academic Search

In the context of virtualized-reality-based tele- micromanipulation, this paper presents a visual calibration technique for an optical microscope coupled to a CCD camera. The accuracy and flexibility of the proposed automatic virtu al calibration method, based on Parallel Single-Plane properties, are outlined. In contrast to standard approaches, a 3D virtual calibration pattern is constructed using the micromanipulator tip with subpixel-order

Mehdi Ammi; Vincent Frand Antoine Ferreira; Antoine Ferreira

2009-01-01

18

Beagle I and II Voyages: Charles Darwin's rocks and the quest for Mars rock; the Open University's virtual microscope has both  

NASA Astrophysics Data System (ADS)

Exploration is in itself a fascinating subject, and a strong draw to engaging the public in understanding science. Nearly two hundred years ago Charles Darwin took part in an exploration of the Earth, and more recently we have begun to explore the solar system and in particular the surface of Mars. The engagement is made easier if an element of exploration is involved in the public engagement, using modern internet and even mobile technologies. The Open University combines all those aspects in a series of virtual microscopes for Earth science that are freely available on the web, installed in museums, or built into its teaching material. The basis of the virtual microscope is a mosaic of several hundred microscopic images of each thin section taken in plane polarised light, between crossed polars and in reflected light, which are then assembled into three high resolution images. Rotation movies for selected points in the thin section illustrate changing optical properties such as birefringence. The user is able to pan and zoom around to explore the section, studying the mineralogy and rock texture, and view the rotation movies linked to points in the section to see the changing birefringence colours. We have created several collections of terrestrial rocks, mainly for teaching purposes, and outreach directly linked to exploration: Charles Darwin returned from the Voyage of the Beagle with a large variety of rock samples, and although thin sections were not being made at that time, they were created from his rocks in the late 19th century. The historic material is part of the "Darwin the Geologist" exhibition at the Sedgwick Museum in Cambridge. Our Darwin virtual microscope includes hand specimen illustrations and thin sections together with documentation and an interactive map allow internet users and museum visitors alike to have a close look at Darwin's rocks and study the petrology of them. Charles Darwin explored distant horizons on Earth in the 19th century; in the 20th century the Apollo astronauts set foot on the Moon, returning valuable rock samples to Earth. Through collaboration between NASA and the OU it became possible to show lunar samples as virtual thin sections. The Beagle II mission represented a new voyage, following Charles Darwin's footsteps, to horizons well beyond the Earth - on a journey to investigate the planet Mars. Although no samples have yet been returned from the red planet, we do have access to Martian meteorites. Like Moon rock samples, these meteorites are rare and very valuable. So, one way to make them accessible to the general public is via the internet using our virtual microscope technology. Within the framework of the EUROPLANET project, and in collaboration with the Natural History Museum in London we are making such meteorites freely available to all. We plan to extend this collection and make it openly accessible for teaching and outreach activities anywhere and any time. Our current microscopes are located at http://microscope.open.ac.uk.

Schwenzer, S. P.; Tindle, A. G.; Anand, M.; Gibson, E. K.; Pearson, V. K.; Pemberton, D.; Pillinger, C.; Smith, C. L.; Whalley, P.; Kelley, S. P.

2011-12-01

19

Microscope.  

National Technical Information Service (NTIS)

In this patent application a microscope is disclosed as incorporating a light source which broadcasts light in succession through a holographic condenser lens, a transparent object support stage, an object to be magnified, a holographic objective lens, a ...

W. N. Mohon

1976-01-01

20

A Digital Approach to Learning Petrology  

NASA Astrophysics Data System (ADS)

In the undergraduate igneous and metamorphic petrology course at Northern Arizona University, we are employing petrographic microscopes equipped with relatively inexpensive ( $200) digital cameras that are linked to pen-tablet computers. The camera-tablet systems can assist student learning in a variety of ways. Images provided by the tablet computers can be used for helping students filter the visually complex specimens they examine. Instructors and students can simultaneously view the same petrographic features captured by the cameras and exchange information about them by pointing to salient features using the tablet pen. These images can become part of a virtual mineral/rock/texture portfolio tailored to individual student's needs. Captured digital illustrations can be annotated with digital ink or computer graphics tools; this activity emulates essential features of more traditional line drawings (visualizing an appropriate feature and selecting a representative image of it, internalizing the feature through studying and annotating it) while minimizing the frustration that many students feel about drawing. In these ways, we aim to help a student progress more efficiently from novice to expert. A number of our petrology laboratory exercises involve use of the camera-tablet systems for collaborative learning. Observational responsibilities are distributed among individual members of teams in order to increase interdependence and accountability, and to encourage efficiency. Annotated digital images are used to share students' findings and arrive at an understanding of an entire rock suite. This interdependence increases the individual's sense of responsibility for their work, and reporting out encourages students to practice use of technical vocabulary and to defend their observations. Pre- and post-course student interest in the camera-tablet systems has been assessed. In a post-course survey, the majority of students reported that, if available, they would use camera-tablet systems to capture microscope images (77%) and to make notes on images (71%). An informal focus group recommended introducing the cameras as soon as possible and having them available for making personal mineralogy/petrology portfolios. Because the stakes are perceived as high, use of the camera-tablet systems for peer-peer learning has been progressively modified to bolster student confidence in their collaborative efforts.

Reid, M. R.

2011-12-01

21

Microscope 16 THE MICROSCOPE  

E-print Network

Microscope 16 THE MICROSCOPE In this exercise you will learn about the principles of optical microscopy and become fa- miliar with the use of the microscope. Microscopes are delicate and expensive instruments; they should be handled with utmost care! Before you use the microscope, your instructor

Koptur, Suzanne

22

Virtual Quarry  

NSDL National Science Digital Library

This interactive virtual tour for younger students lets them 'drive' a quarry truck and visit a rock quarry to see how the rock is mined, processed and transported, and what the aggregate is used for. The tour includes safety tips for visiting quarries. They can also 'restore' an abandoned quarry by planting virtual grass, reeds, and trees, view movies about quarries, and use a virtual microscope to look at some rock samples. There are also links to lesson plans on the use and restoration of quarries.

23

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

24

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

25

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

26

Mind Over Magma: The Story of Igneous Petrology  

NASA Astrophysics Data System (ADS)

In the centuries that enquiring minds have studied and theorized about igneous rocks, much progress has been made, both in accumulating observations and in developing theories. Yet, writing a history of this progress is a daunting undertaking. The volume of the literature is vast and in multiple languages; the various lines of inquiry are diverse and complex; and the nomenclature is sometimes abstruse. On top of these challenges, many of its principal issues have yet to find a definitive consensus. With the exception of a few topical studies, historians of science have virtually avoided the subject. In Mind Over Magma: The Story of Igneous Petrology, Davis Young has taken on the challenge of writing a comprehensive survey of the study of igneous rocks, and the result has been a remarkable book of meticulous scholarship. Igneous petrology is a vast subject, and it is not obvious how best to organize its history. Young takes a topical approach, generally grouping together various studies by either the problem being investigated or the method of attack. These topics span the earliest times to the present, with an emphasis on recurring themes, such as the causes of magmatic diversity and the origins of the granitic rocks. The range of topics includes most of the subjects central to the field over its history. As much as is practical, topics are discussed in chronological order, and along the way, the reader is treated to biographical sketches of many of the key contributors. This organization proves effective in dealing with the multitude of concepts.

Snyder, Don

2004-01-01

27

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

28

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

29

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

NASA Astrophysics Data System (ADS)

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.

30

Petrologic and mineralogic investigation of some crystalline rocks returned by the Apollo 14 mission.  

NASA Technical Reports Server (NTRS)

Apollo 14 crystalline rocks (14053 and 14310) and crystalline rock fragments (14001,7,1; 14001,7,3; 14073; 14167,8,1 and 14321,191,X-1) on which Rb/Sr, Ar-40/Ar-39, or cosmic ray exposure ages have been determined by our colleagues were studied with the electron microprobe and the petrographic microscope. Rock samples 14053 and 14310 are mineralogically and petrologically distinct from each other. On the basis of mineralogic and petrologic characteristics all of the fragments, except 14001,7,1, are correlative with rock 14310. Sample 14073 is an orthopyroxene basalt with chemical and mineralogic affinities to ?KREEP,' the ?magic' and ?cryptic' components. Fragment 14001,7,1 is very similar to Luny Rock I.

Gancarz, A. J.; Albee, A. L.; Chodos, A. A.

1971-01-01

31

Focusing One's Microscope By Daniel Pauly  

E-print Network

The Lead Focusing One's Microscope By Daniel Pauly Sea Around Us Project, Fisheries Centre discoveries are often a matter of focusing one's microscope -- actual or virtual -- and so rules have emerged's Microscope. The Science Chronicles (The Nature Conservancy), January 2011: 4-7. #12;! Establishing

Pauly, Daniel

32

Barbara Nash: Recent Publications Petrology and Volcanology  

E-print Network

, Anthony R., Hughes, John M., Nash, Barbara P., and Marty, Joe, 2014. Kokinosite, Na2Ca2(V10O28)�24H2OBarbara Nash: Recent Publications Petrology and Volcanology Oviatt, Charles G. and Nash, Barbara P Geological Survey. http://geology.utah.gov/online/mp/mp14-1.pdf Brown, F. H., Nash, Barbara P., Fernandez, D

Johnson, Cari

33

PET: petrological elementary tools for mathematica  

Microsoft Academic Search

PET is a Mathematica package that supplies elementary tools for fulfilling various petrological tasks. Among these are mineral formula calculation (including nomenclature for amphibole according to the IMA sheme), calculation of mineral equilibria from internally consistent thermodynamic data sets (Berman or Holland and Powell), calculation of single equilibrium geothermobarometers (25 of the most common thermometers, 10 barometers), access to the

Edgar Dachs

1998-01-01

34

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

35

Virtual Lab Educational Software  

NSDL National Science Digital Library

NASA Learning Technologies (NLT) is a NASA R&D effort for the engineering of teaching tools that deliver NASA content in the most engaging and dynamic manner possible. NLT builds the pipeline and the delivery point for unencumbered access to the best data NASA has to provide. Virtual Lab completely emulates a scanning electron microscope and allows any user to zoom and focus into a variety of built-in microscopic samples. It also comes with a set of educational materials such as a demo on how a SEM works and movies of the real thing in action. Virtual Lab is freely available with a growing library of samples to choose from.

Hogan, Patrick; Kim, Randolph

2008-11-18

36

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

37

Rethinking how Undergraduate ``Hard Rock'' Petrology is Taught  

NASA Astrophysics Data System (ADS)

A course in "hard rock" petrology forms a core component of undergraduate training in the geosciences. In most cases, the subjects of igneous and metamorphic petrology are combined in a single course and the course is traditionally structured so that the two subjects are covered in series. This approach enables students to focus on each subject separately, with knowledge of igneous rocks helping students to understand metamorphic rock protoliths. Student assessment shows, however, that this approach tends to compartmentalize learning and the two main subjects might just as well be taught in separate courses. In practical applications such as fieldwork, students must be able to access their understanding of igneous and metamorphic rocks virtually simultaneously. To better integrate student learning, I developed a spiral learning approach to teaching petrology (e.g., Bruner, 1990; Dyar et al., 2004) so that commonalities could be revisited several times over the course of a semester and, in so doing, students' grasp of the fundamental insights provided by igneous and metamorphic rocks could be scaffolded into greater understanding. The course initially focuses on the dynamics of the environments in which igneous and metamorphic rocks form: heat flow, fluid flow, and plate tectonics. Several subsequent weeks explore topics relevant to identifying and understanding igneous and metamorphic rocks in the field: crystal nucleation and growth, the roles of pressure and heat, and field classification. Laboratory exercises parallel this structure, also emphasizing observations that are valuable in the field: the relationship between minerals and rocks, textural observations, and general rock classification. The final portion of the course explores “hard rocks” in more detail with a greater emphasis on the interplay between chemistry and mineralogy. A variety of learner-centered activities in the course help students bridge the gap between novice and expert and include more explicit emphasis on visualization and on helping students become comfortable with interpreting data numerically and graphically. Pen tablet computers are used extensively in the laboratory for visualization, photomicrograph capture, and annotation. Cooperative learning activities developed for this course make use of learning methods such as pair share, round-robin, small group explorations case studies, and jigsaw exercises (sometimes as introduction to, sometimes as review of material), and Jeopardy-style review sessions. On an assessment questionnaire at the end of the semester students ranked the in-class cooperative learning activities as on par with lectures and homework exercises in facilitating their learning. Students reported satisfactory attainment of three major goals identified for the course even though they were not explicitly reminded of these goals at the time of assessment. References cited: Bruner, J., 1990. Acts of Meaning. Harvard University Press.; Dyar, M.D., Gunter, M.E., Davis, J.C., and Odell, M.R., 2004. Integration of new methods into teaching mineralogy; Huba, M.E. and Freed, J.E., 2000. Learner-centered Assessment on College Campus: Shifting the Focus from Teaching to Learning. Allyn and Bacon.

Reid, M. R.

2010-12-01

38

In vivo virtual intraoperative surgical photoacoustic microscopy  

SciTech Connect

We developed a virtual intraoperative surgical photoacoustic microscopy system by combining with a commercial surgical microscope and photoacoustic microscope (PAM). By sharing the common optical path in the microscope and PAM system, we could acquire the PAM and microscope images simultaneously. Moreover, by employing a beam projector to back-project 2D PAM images onto the microscope view plane as augmented reality, the conventional microscopic and 2D cross-sectional PAM images are concurrently mapped on the plane via an ocular lens of the microscope in real-time. Further, we guided needle insertion into phantom ex vivo and mice skins in vivo.

Han, Seunghoon, E-mail: hsh860504@gmail.com; Kim, Sehui, E-mail: sehui0916@nate.com; Kim, Jeehyun, E-mail: jeehk@knu.ac.kr, E-mail: chulhong@postech.edu [School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu 702-701 (Korea, Republic of)] [School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Lee, Changho, E-mail: ch31037@postech.edu; Jeon, Mansik, E-mail: msjeon@postech.edu [Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)] [Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Kim, Chulhong, E-mail: jeehk@knu.ac.kr, E-mail: chulhong@postech.edu [Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of) [Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Department of Biomedical Engineering, The State University of New York at Buffalo, Buffalo, New York 14221 (United States)

2013-11-11

39

Lunar composition - A geophysical and petrological synthesis  

NASA Technical Reports Server (NTRS)

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, Steve; Phillips, Roger J.; Taylor, G. Jeffrey

1988-01-01

40

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

41

Petrological and rheological controls on volcanism to terrestrial planets  

E-print Network

Through experimental petrology and geodynamic modeling, processes of melting under thick lithospheres on the Earth and the moon are investigated. Phase equilibrium experiments were carried out on Apollo 14B and 15C picritic ...

Elkins Tanton, Linda Tarbox, 1965-

2002-01-01

42

Petrological evidence for secular cooling in mantle Claude Herzberg1  

E-print Network

LETTERS Petrological evidence for secular cooling in mantle plumes Claude Herzberg1 & Esteban Gazel at present. Iceland also exhibits secular cooling, in agree- ment with previous studies3,4 . Our work for secular cooling of the Galapagos plume.

43

Virtual strings  

Microsoft Academic Search

A virtual string is a scheme of self-intersections of a closed curve on a surface. We introduce virtual strings and study their geometric properties and homotopy invariants. We also discuss connections between virtual strings, Gauss words, and virtual knots.

Vladimir Turaev

2003-01-01

44

Microscope and method of use  

DOEpatents

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. 7 figs.

Bongianni, W.L.

1984-04-17

45

Microscope and method of use  

DOEpatents

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, Wayne L. (Los Alamos, NM)

1984-01-01

46

Cratonization: a thermal and petrological perspective  

SciTech Connect

The long term thermal and tectonic history of the continental lithosphere derives from the processes that lead to crationization. Cratons are characterized by mechanical stability, buoyancy and freeboard, a paucity of magmatism, and deep roots. The process is not slow and gradual, extending over aeons, but rather is relatively rapid, being accomplished in a period on the order of 300-500 Ma; cratonic nuclei existed by the end of the Archean. The essential process is devolatilization of the upper mantle, in associations with major orogenic events, to a depth of about 300 km. Devolatilization has the following effects: 1) it elevates the solidus of the affected lithosphere, making it less vulnerable to subsequent melting, 2) it augments the mechanical strength and stiffness of the region by increasing the activation energy, thereby 3) enhancing the structural stability of the lithosphere, thickening it, and extending to greater depths the region in which conduction is the principal mode of heat transfer, thereby 4) maintaining freeboard by the thermal expansion of the extended lithosphere because of the higher temperatures of the conductive thermal regime, and 5) enhancement of buoyancy by thermal expansion and petrological differentiation. The process of cratonization can be reversed by reintroduction of volatiles for the deeper mantle, or by raising the temperature sufficiently to reach the volatile-free refractory solidus. Mantle metasomatic processes probably promote destabilization by recharging the thick need lithosphere with both volatiles and heat producing isotopes.

Pollack, H.N.

1985-01-01

47

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

48

Petrology, Mineralogy, and Genesis of Lunar Crystalline Igneous Rocks  

Microsoft Academic Search

Information on the mineralogy and petrology of the Apollo 11 crystalline basaltic rocks, obtained by about 35 groups of investigators, is summarized and used as a basis for speculation. The textural assemblage indicates near-surface, rapid crystallization from low-viscosity basaltic magmas under low oxygen pressures. The basalts are subsilicic and subalkaline, but only locally, titaniferous. Terrestrial alkali basalts could, through alkali

G. Malcolm Brown

1970-01-01

49

History of applied coal petrology in the United States  

Microsoft Academic Search

In May of 1992, a seminar entitled “An Oral History of Applied Coal Petrography and the Triangle Run” was held at Southern Illinois University, Carbondale, for the purpose of recording the personal accounts of four of the principal scientists involved in the initial application of coal petrology to the manufacture of metallurgical coke and subsequent developments. The four scientists included

Linda A. F Dutcher; John C Crelling

2000-01-01

50

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

51

Virtual Laboratories and Virtual Worlds  

E-print Network

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)

Piet Hut

2007-12-11

52

Virtual Labs and Virtual Worlds  

NASA Astrophysics Data System (ADS)

Virtual Labs and Virtual Worlds Coastline Community College has under development several virtual lab simulations and activities that range from biology, to language labs, to virtual discussion environments. Imagine a virtual world that students enter online, by logging onto their computer from home or anywhere they have web access. Upon entering this world they select a personalized identity represented by a digitized character (avatar) that can freely move about, interact with the environment, and communicate with other characters. In these virtual worlds, buildings, gathering places, conference rooms, labs, science rooms, and a variety of other “real world” elements are evident. When characters move about and encounter other people (players) they may freely communicate. They can examine things, manipulate objects, read signs, watch video clips, hear sounds, and jump to other locations. Goals of critical thinking, social interaction, peer collaboration, group support, and enhanced learning can be achieved in surprising new ways with this innovative approach to peer-to-peer communication in a virtual discussion world. In this presentation, short demos will be given of several online learning environments including a virtual biology lab, a marine science module, a Spanish lab, and a virtual discussion world. Coastline College has been a leader in the development of distance learning and media-based education for nearly 30 years and currently offers courses through PDA, Internet, DVD, CD-ROM, TV, and Videoconferencing technologies. Its distance learning program serves over 20,000 students every year. sponsor Jerry Meisner

Boehler, Ted

2006-12-01

53

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

54

Virtual Satellite  

NASA Technical Reports Server (NTRS)

Virtual Satellite (VirtualSat) is a computer program that creates an environment that facilitates the development, verification, and validation of flight software for a single spacecraft or for multiple spacecraft flying in formation. In this environment, enhanced functionality and autonomy of navigation, guidance, and control systems of a spacecraft are provided by a virtual satellite that is, a computational model that simulates the dynamic behavior of the spacecraft. Within this environment, it is possible to execute any associated software, the development of which could benefit from knowledge of, and possible interaction (typically, exchange of data) with, the virtual satellite. Examples of associated software include programs for simulating spacecraft power and thermal- management systems. This environment is independent of the flight hardware that will eventually host the flight software, making it possible to develop the software simultaneously with, or even before, the hardware is delivered. Optionally, by use of interfaces included in VirtualSat, hardware can be used instead of simulated. The flight software, coded in the C or C++ programming language, is compilable and loadable into VirtualSat without any special modifications. Thus, VirtualSat can serve as a relatively inexpensive software test-bed for development test, integration, and post-launch maintenance of spacecraft flight software.

Hammrs, Stephan R.

2008-01-01

55

Petrologic and Chemical Characterization of a Suite of Antarctic Diogenites  

NASA Technical Reports Server (NTRS)

The origin of diogenites, ultramafic cumulates related to eucrites, is an unresolved problem [1]. Most diogenites are orthopyroxenites, a few are harzburgites [2], and some are transitional to cumulate eucrites [1, 3]. Cumulate eucrites are gabbros formed by crystal fractionation from basaltic eucrites [4]. The consensus view is that basaltic eucrites are residual melts from global-magma-ocean crystallization on their parent asteroid [4] which is plausibly Vesta [5]. However, the petrologic and compositional characteristics of diogenites seem to preclude a magma ocean origin [1, 4]. We are doing a petrologic and chemical study of new or unusual diogenites with the ultimate goals of constraining their genesis, and the geologic evolution of Vesta.

Mittlefehldt, D. W.; Mertzman, S. A.; Peng, Z. X.; Mertzman, K. R.

2013-01-01

56

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.

57

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

58

Virtual Eunuchs  

E-print Network

. What's more, eunuchs were the only men allowed in the women's quarters. Regrettably, career opportunities for professional eunuchs in this century are limited. But only if you are operating in real reality. Virtual reality is bringing the eunuch back...

Hacker, Randi; Greene, Megan

2009-01-07

59

Virtual Teams.  

ERIC Educational Resources Information Center

Virtual work teams scattered around the globe are becoming a feature of corporate workplaces. Although most people prefer face-to-face meetings and interactions, reality often requires telecommuting. (JOW)

Geber, Beverly

1995-01-01

60

Virtual data  

SciTech Connect

In the 1970`s, when computers were memory limited, operating system designers created the concept of ``virtual memory`` which gave users the ability to address more memory than physically existed. In the 1990s, many large control systems have the potential for becoming data limited. We propose that many of the principles behind virtual memory systems (working sets, locality, caching, and clustering) can also be applied to data-limited systems - creating, in effect, ``virtual data systems.`` At the Los Alamos National Laboratory`s Clinton P. Anderson Meson Physics Facility (LAMPF), we have applied these principles to a moderately sized (10,000 data points) data acquisition and control system. To test the principles, we measured the system`s performance during tune-up, production, and maintenance periods. In this paper, we present a general discussion of the principles of a virtual data system along with some discussion of our own implementation and the results of our performance measurements.

Bjorklund, E.

1993-11-01

61

Virtually Possible  

NSDL National Science Digital Library

This is a ray drawing activity to aid students in their understanding of how virtual images are formed by plane mirrors, and how the image size and distance from the mirror compare to those of the object.

Depalma, Darlene

2012-06-22

62

Virtual memory  

NASA Technical Reports Server (NTRS)

Virtual memory was conceived as a way to automate overlaying of program segments. Modern computers have very large main memories, but need automatic solutions to the relocation and protection problems. Virtual memory serves this need as well and is thus useful in computers of all sizes. The history of the idea is traced, showing how it has become a widespread, little noticed feature of computers today.

Denning, P. J.

1986-01-01

63

Virtual Specimens  

NASA Astrophysics Data System (ADS)

Virtual Field Trips have been around almost as long as the Worldwide Web itself yet virtual explorers do not generally return to their desktops with folders full of virtual hand specimens. Collection of real specimens on fields trips for later analysis in the lab (or at least in the pub) has been an important part of classical field geoscience education and research for generations but concern for the landscape and for preservation of key outcrops from wanton destruction has lead to many restrictions. One of the author’s favorite outcrops was recently vandalized presumably by a geologist who felt the need to bash some of the world’s most spectacular buckle folds with a rock sledge. It is not surprising, therefore, that geologists sometimes leave fragile localities out of field trip itineraries. Once analyzed, most specimens repose in drawers or bins, never to be seen again. Some end up in teaching collections but recent pedagogical research shows that undergraduate students have difficulty relating specimens both to their collection location and ultimate provenance in the lithosphere. Virtual specimens can be created using 3D modeling software and imported into virtual globes such as Google Earth (GE) where, they may be linked to virtual field trip stops or restored to their source localities on the paleo-globe. Sensitive localities may be protected by placemark approximation. The GE application program interface (API) has a distinct advantage over the stand-alone GE application when it comes to viewing and manipulating virtual specimens. When instances of the virtual globe are embedded in web pages using the GE plug-in, Collada models of specimens can be manipulated with javascript controls residing in the enclosing HTML, permitting specimens to be magnified, rotated in 3D, and sliced. Associated analytical data may be linked into javascript and localities for comparison at various points on the globe referenced by ‘fetching’ KML. Virtual specimens open up new possibilities for distance learning, where design of effective lab exercises has long been an issue, and they permit independent evaluation of published field research by reviewers who do not have access to the physical field area. Although their creation can be labor intensive, the benefits of virtual specimens for education and research are potentially great. Interactive 3D Specimen of Sierra Granodiorite at Outcrop Location

de Paor, D. G.

2009-12-01

64

Automatic Camera-based Microscope Calibration for a Tele-Micromanipulation System using a  

E-print Network

1 Automatic Camera-based Microscope Calibration for a Tele-Micromanipulation System using a Virtual a visual calibration technique for an optical microscope coupled to a CCD camera. The accuracy of the workspace is reconstructed through the real-time imaging of two perpendicular optical microscopes. Our

Paris-Sud XI, Université de

65

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

66

Hayden Planetarium: Virtual Observatory  

NSDL National Science Digital Library

This online Hayden Planetarium resource explains the concept of the Virtual Observatory and contains links to the following eight sites: International Virtual Observatory Alliance, National Virtual Observatory, National Virtual Observatory Education and Outreach, Astrophysical Virtual Observatory, Canadian Virtual Observatory, AstroGrid, SkyView, and Theory in a Virtual Observatory.

67

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

68

The Scanning Optical Microscope.  

ERIC Educational Resources Information Center

Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

Sheppard, C. J. R.

1978-01-01

69

Virtual Labs  

NSDL National Science Digital Library

Over the past few years, the Howard Hughes Medical InstituteâÂÂs Biointeractive website has garnered critical acclaim from a number of international organizations that evaluate various multimedia products that educate Internet users about science and technology. Most recently, their Virtual Labs area on the site has been well-received, and they are visually entrancing and easy to use. Currently, the site contains five full virtual labs, and they include those that allow students to learn how to identify various bacteria and another one that casts participants as a young intern who is learning how to identify heritable diseases of the heart. Each virtual lab contains resources for instructors, along with an interactive quiz.

70

Virtual Labs  

NSDL National Science Digital Library

Over the past few years, the Howard Hughes Medical InstituteâÂÂs Biointeractive website has garnered critical acclaim from a number of international organizations that evaluate various multimedia products that educate Internet users about science and technology. Most recently, their Virtual Labs area on the site has been well-received, and they are visually entrancing and easy to use. Currently, the site contains six full virtual labs, and they include those that allow students to learn how to identify various bacteria and another one that casts participants as a young intern who is learning how to identify heritable diseases of the heart. Each virtual lab contains resources for instructors, along with an interactive quiz.

2007-04-17

71

The virtual blood film.  

PubMed

The computer and the digital camera offer unprecedented possibilities for improving hematology education, research, and patient service. Peripheral blood smear images of exceptional quality can be acquired rapidly and conveniently from the peripheral blood smear with a modern, high-resolution digital camera and a quality microscope. Digital cameras use CCD or CMOS image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal. Because digital cameras do not use photographic film, images are immediately available for incorporation into web sites or digital publications, printing, transfer to other individuals by e-mail, or other applications. Several excellent consumer digital still cameras are now available for less than $1000 that capture high-quality images comprised of more than three megapixels. These images are essentially indistinguishable from conventional film images when viewed on a quality color monitor or printed on a quality color or black and white printer at sizes up to 8 x 10 in. Several recent dedicated digital photomicroscopy cameras provide an ultrahigh quality image output of more than 12 megapixels and have low noise circuit designs permitting the direct capture of darkfield and fluorescence images. There are many applications of digital images of peripheral blood smears. Because hematology is a visual science, the inclusion of quality digital images into lectures, teaching handouts, and electronic documents is essential. A few institutions have gone beyond the basic application of digital images to develop large electronic hematology atlases; animated, audio-enhanced learning experiences; multidisciplinary Internet conferences; and other innovative applications. Digital images of single microscopic fields (single-frame images) are the most widely used in hematology education at this time, but single images of many adjacent microscopic fields can be stitched together to prepare zoomable panoramas that encompass a large part of a microscope slide and closely stimulate observation through a real microscope. With further advances in computer speed and Internet streaming technology, the virtual microscope could easily replace the real microscope in pathology education. Interactive, immersive computer experiences may completely revolutionize hematology education and make the conventional lecture and laboratory format obsolete later in this decade. Patient care is enhanced by the transmission of digital images to other individuals for consultation and education, and by the inclusion of these images in patient care documents. In research laboratories, digital cameras are widely used to document experimental results and obtain experimental data. PMID:11933581

Riley, Roger S; Ben-Ezra, Jonathan M; Massey, Davis; Cousar, John

2002-03-01

72

Seismic wave velocity of rocks in the Oman ophiolite: constraints for petrological structure of oceanic crust  

Microsoft Academic Search

Evaluation of rock velocities and comparison with velocity profiles defined by seismic refraction experiments are a crucial approach for understanding the petrological structure of the crust. In this study, we calculated the seismic wave velocities of various types of rocks from the Oman ophiolite in order to constrain a petrological structure of the oceanic crust. Christensen & Smewing (1981, JGR)

S. Saito; M. Ishikawa; S. Shibata; R. Akizuki; M. Arima; Y. Tatsumi; S. Arai

2010-01-01

73

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

Microsoft Academic Search

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

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

2003-01-01

74

Massive atmospheric sulfur loading of the AD 1600 Huaynaputina eruption and implications for petrologic sulfur estimates  

E-print Network

Massive atmospheric sulfur loading of the AD 1600 Huaynaputina eruption and implications for petrologic sulfur estimates Fidel Costa1 and Bruno Scaillet Institut des Sciences de la Terre d'Orle´ans, UMR petrological, analytical, and thermodyna- mical data to constrain the sulfur yield of the AD 1600 Huaynaputina

Paris-Sud XI, Université de

75

A Collaborative Approach to Petrologic Monitoring of the Mt. Saint Helens 2004 Eruption  

Microsoft Academic Search

During the first 3 weeks of MSH 2004 eruptive activity, petrologic evaluation of small amounts of volcanic ash provided our only direct means to determine if volcanic unrest was magmatic or hydrothermal in origin. Petrologic monitoring began with collection of ash from solar panels and tree leaves proximal to the crater, shortly after the initial phreatic explosive event on October

C. Thornber; M. Rowe; J. Pallister; D. Gooding; D. Ramsey; J. Ewert; M. Couchman; D. Dzurisin; R. Hoblitt; M. Clynne; J. Lowenstern; J. Vallance; K. Cashman

2004-01-01

76

Petrological geodynamic modeling of mid-ocean ridges  

NASA Astrophysics Data System (ADS)

Mid-ocean ridges are the primary location where the Earth's oceanic crust is formed. Beneath spreading ridges several processes such as dynamic melting and partial crystallization modify the petrology of the upper mantle and affect the Earth's global geochemical evolution. A unified picture of the temporal and spatial evolution of melt and residual mantle, as well as crustal production and melt dynamics requires a comprehensive model that takes into account simultaneously the complexity of the physical processes involved and the petrological variations of the ridge system. Here we present the first results of a 2-D numerical approach applied to a spreading ridge that fully couples a two-phase flow model for melt and solid mantle and a chemical thermodynamic model which provides a spatial and temporal description of the minerals and melt abundance and composition. The most significant features found by this study are the following. (1) Accumulation of melt is observed at the base of the lithosphere in the off-axis region (<˜50 km from the ridge axis). (2) Crustal production (thickness) shows temporal variations which are mainly induced by periodic discharge of the melt accumulated underplate. (3) Magma waves develop between 10 and 30 km depth in proximity of the ridge axis. However to accurately resolve melt fluctuations, the grid size must be smaller than the compaction length for porous flow. Since in this study the compaction length decreases with depth, we have used a simplified 1-D melt model incorporating the two-phase flow dynamics and the thermodynamic formulation to show that the depth at which magma waves start to form increases by increasing the numerical resolution. Despite the limitation of the numerical grid resolution, we have observed that variations of the melt content do not appear to have significant influence on major elements composition of the residual solid and melt. (4) In the initial stage of the ridge evolution, a melting area detaches from the main melting region around the ridge axis. It is possible that this type of development may repeat over time beyond the duration of the simulation model of this study (˜15 Ma). Sluggish coupling between the dynamics of the lithosphere and the asthenospheric mantle flow suggests that accretion of the lithosphere by conductive cooling away from the ridge center involves portions of the upper mantle that not necessarily passed through the spreading ridge. (5) During the development of the spreading ridge, the asthenosphere affected by the melting process deflects downwards, creating in this way a chemical heterogeneity in the large mantle circulation. (6) Composition of major elements in the residual solid after partial melting is in agreement with the chemical pattern observed in abyssal peridotites. However, in order to explain the large variation of major elements content found in abyssal peridotite, a consistent petrological and geodynamic model of the evolution of the mid-ocean ridge, requires that partial crystallization of small amount of melt refertilizes the depleted mantle. The petrological model presented in this study accounts for the complexity of polybaric dynamic melting and the continuous reactions between the residual solid and melt, but it is limited by the assumption of local thermodynamic equilibrium within a domain defined by the numerical grid size. The interpretation of the petrological results needs to be carefully evaluated to ensure that the time and space scale of the numerical model complies with the constraints provided by solid-melt reactive experiments and the spatial scale of the petrological structures observed in mid-ocean ridges. (7) Melt distribution and thermal structure are revealed by the seismic shear wave map computed from the numerical model. Certain observations, such as the extent of the melting region, overall agree quite well with the evidences from seismic studies from various ridge settings.

Tirone, M.; Sen, G.; Morgan, J. P.

2012-01-01

77

Geochemical and petrological observations of gas transport at arc volcanoes  

NASA Astrophysics Data System (ADS)

Understanding the abundance and composition of vapour in magma chambers and the mechanisms of vapour transport in volcanic systems is of immense importance. Exsolved vapour in a magma storage area affects eruption style and duration, and influences ground deformation and other geophysical manifestations owing to its compressibility. Ultimately, we wish to understand how much pre-eruptive exsolved vapour exists and what role mafic magma supply at depth plays in supplying it. Soufriere Hills Volcano, Montserrat, has become an exceptionally well-monitored volcanic system and there is now an abundance of detailed geochemical and petrological information regarding magma degassing and gas transport processes. The eruption provides a unique opportunity to study the effects of open system mafic magma injection, mingling and degassing, which is occurring on the same time scale as eruption. We examine the geochemical and petrological evidence for magma mingling, degassing and gas fluxing at Soufriere Hills Volcano. We use measurements of gas flux and composition, using DOAS and a multigas sensor. We examine petrological and textural evidence for mafic magma supplying volatiles to the system, including evidence from phenocryst zoning and composition. We show that the mafic magma supplies volatiles as well as heat to the overlying resident andesite. Due to the strong partitioning of sulphur into a vapour phase at depth under oxidising conditions, the sulphur dissolved in the intruding mafic magma becomes segregated into vapour, along with carbon dioxide and water. The vapour is transported to the surface during both eruptive and non-eruptive periods, implying either that significant permeability exists within the system, or that magma convection operates. There is some evidence for gas fluxing, which suggests that gas may be transported through the magma. We draw comparisons with other recent studies of volatile transport in arc systems to show that some observations may be generic.

Edmonds, M.; Herd, R. A.; Humphreys, M.; Aiuppa, A.; Giudice, G.; Guida, R.; Moretti, R.; Christopher, T. E.; Rawson, H.

2010-12-01

78

Mineralogic and petrologic studies of meteorites and lunar samples  

NASA Technical Reports Server (NTRS)

During a 13 year period beginning in 1971, the Extraterrestrial Petrology Group examined lunar soils from all 6 Apollo missions and those returned by the Soviet Luna 16, Luna 20, and Luna 24 missions. In addition, the properties and apparent origin of the carbonaceous chondrites were examined. Chondrules, calcium-aluminum-rich inclusions (CAI) and the fine grained matrix materials that accompany chondrules and CAI's in primitive meteorites were investigated. The effects of planetary hydrothermal alteration of matrix materials in the C1 chondrite was also investigated. Full length papers and extended abstracts published during the grant are listed chronologically.

Wood, J. A.

1984-01-01

79

Virtual sound for virtual reality  

SciTech Connect

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 representations can be no better than the graphics. Computer graphics is still limited in its ability to generate complex objects such as landscapes and humans. Nevertheless, useful and convincing visualizations are made through a variety of techniques. The central theme of this article is that a similar situation is true with sound for virtual reality. It is beyond our abilityto create interactive soundscapes that create a faithful reproduction of real world sounds, however, by choosing one`s application carefully and using sound to enhance a display rather than only mimic real-world scenes, a very effective use of sound can be made.

Blattner, M.M. [Anderson (M.D.) Cancer Center, Houston, TX (United States). Dept. of Biomathematics]|[Lawrence Livermore National Lab., CA (United States)]|[California Univ., Davis, CA (United States); Papp, A.L. III [California Univ., Davis, CA (United States)]|[Lawrence Livermore National Lab., CA (United States)

1993-02-01

80

Virtual sound for virtual reality  

SciTech Connect

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 representations can be no better than the graphics. Computer graphics is still limited in its ability to generate complex objects such as landscapes and humans. Nevertheless, useful and convincing visualizations are made through a variety of techniques. The central theme of this article is that a similar situation is true with sound for virtual reality. It is beyond our abilityto create interactive soundscapes that create a faithful reproduction of real world sounds, however, by choosing one's application carefully and using sound to enhance a display rather than only mimic real-world scenes, a very effective use of sound can be made.

Blattner, M.M. (Anderson (M.D.) Cancer Center, Houston, TX (United States). Dept. of Biomathematics Lawrence Livermore National Lab., CA (United States) California Univ., Davis, CA (United States)); Papp, A.L. III (California Univ., Davis, CA (United States) Lawrence Livermore National Lab., CA (United States))

1993-02-01

81

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

82

Virtual Theatre  

Microsoft Academic Search

The interest for video streaming has increased considerably over the past few years due to the sites like YouTube, Metacafe and so on. However there still hasn't been a single site developed which will allow the users to watch the entire movie online with all his friends physically scattered but sitting virtually together like in a theatre . Further all

S. T. Chaudhari; S. Bodke; R. Chandsarkar; T. Sule

2010-01-01

83

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

84

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

85

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

86

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

87

Virtual impactor  

DOEpatents

A virtual impactor 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 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.

Yeh, Hsu-Chi (Albuquerque, NM); Chen, Bean T. (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM); Newton, George J. (Albuquerque, NM)

1988-08-30

88

Virtual Dice  

NSDL National Science Digital Library

This interactive Flash applet contains a set of four virtual dice with 6, 8, 10 and 12 faces. Clicking a chosen die generates a random value. The values on each die can be customized with the user's own choices to provide flexibility. These values can be up to five digits long and include either positive, negative or a combination of numbers, and can include text or symbols. The dice can be used to generate random numbers in game situations or in studying probability.

Services, Bbc O.

2012-01-01

89

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. >.

90

Virtual Reality  

Microsoft Academic Search

Abstract vjVTK is a small toolkit enabling the use of the Visualization ToolKit (VTK) native ly within the VRJuggler Virtual Reality framework. The toolkit enables a departure from the traditional v isualization calculation-conversionimmersive,viewing cycle. vjVTK leverages the OpenGL capabilities of VTK to a llow it to run as a native graphics generation tool within the VRJuggler framework. This removes,the need

2006-01-01

91

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

92

[Virtual colonoscopy].  

PubMed

Colorectal cancer is a leading cause of cancer death in the western world. Virtual colonoscopy is a new method for 2-D and 3-D imaging of the colon, using a multislice helical CT technology. This method has already demonstrated excellent results in polyp and cancer detection, having similar accuracy to endoscopic colonoscopy in the detection of polyps above 6 mm in size. The major application of this novel technique is in diagnosing cases where conventional colonoscopy fails to demonstrate the entire colon due to technical problems. The second important application is to investigate the colon proximal to an obstructing tumor, where both barium enema and colonoscopy cannot overcome the obstruction. The possibility of widespread application remains in evaluating the use of virtual colonoscopy in a purely screening population. Further developments, including stool tagging, computer aided detection of polyps and faster scanners will contribute to accuracy and patient compliance with widespread use of virtual colonoscopy. This examination may dramatically improve population participation in screening programs and play a major role in minimizing the impact of colorectal cancer. PMID:12362486

Barmeir, Elisha

2002-09-01

93

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

94

Autonomous Virtual Actors Based on Virtual Sensors  

Microsoft Academic Search

In this paper, we present current research developments in the Virtual Life of autonomous synthetic actors. After a brief description of the perception action principles with a few simple examples, we emphasize the concept of virtual sensors for virtual humans. In particular, we describe in details our experiences in implementing virtual vision, tactile and audition. We then describe perception-based locomotion,

Daniel Thalmann; Hansrudi Noser; Zhiyong Huang

1997-01-01

95

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

96

Virtual Microbiology  

NSDL National Science Digital Library

Created at the University of Wisconsin, the Virtual Microbiology site contains a wide range of high-quality scientific educational materials that are meant to supplement and enhance more traditional materials. This particular item is an online textbook, divided into eighteen chapters. Of course, there are the traditional text passages and charts to enhance all of the material, but there are also number of nifty videos that provide additional exploration of topics like pond microbes and hands-on demonstrations. Visitors can also sign up to receive updates about new materials that make their way to the site and they can also provide user feedback.

97

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

98

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

99

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

100

Magnesium-rich crustal compositions on Mercury: Implications for magmatism from petrologic modeling  

E-print Network

Magnesium-rich crustal compositions on Mercury: Implications for magmatism from petrologic modeling: Stockstill-Cahill, K. R., T. J. McCoy, L. R. Nittler, S. Z. Weider, and S. A. Hauck II (2012), Magnesium

Hauck II, Steven A.

101

Petrology and geochemistry of pyroxenites in the Lanzo ultramafic massif, Northwestern Italy  

E-print Network

Combined field, microtextural, and geochemical observations are presented for pyroxenites in the Lanzo ultramafic massif in order to place chemical and petrological constraints both locally on the geologic history of the ...

Pesce, Kathryn A

2012-01-01

102

[Microscopic colitis: update 2014].  

PubMed

Microscopic colitis, which includes lymphocytic colitis and collagenous colitis, represents a frequent cause of chronic watery diarrhea especially in the elderly population. Several medications, such as nonsteroidal antiinflammatory drugs, proton pump inhibitors or antidepressants, as well as cigarette smoking have been recognized as risk factors for microscopic colitis. The diagnosis of microscopic colitis is based on a macroscopically normal ileo-colonoscopy and several biopsies from the entire colon, which demonstrate the pathognomonic histopathologic findings. Therapy is mainly based on the use of budesonide. Other medications, such as mesalazine, cholestyramine and bismuth, have been evaluated as well but the evidence is less solid. PMID:25276996

Burgmann, Konstantin; Fraga, Montserrat; Schoepfer, Alain M; Yun, Pu

2014-09-01

103

Petrology of the Middle Jurassic (?) La Joya Formation, Sierra Madre Oriental, Southwestern Tamaulipas, Mexico  

E-print Network

PETROLOGY OF THE MIDDLE JURASSIC( 2) LA JOYA FORMATION, SIERRA MADRE ORIENTAL, SOUTHWESTERN TAMAULIPAS, MEXICO A Thesis by WOODS WILKINSON ALLEN JR. Submitted to the Graduate College of Texas A8 M Univ er si t y in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE December 1976 Major Subject: Geology PETROLOGY OF THE MI DDLE JURASS IC ( 2 ) LA JOYA FORMATION & SIERRA MADRE ORIENTAL, SOUTHWESTERN TAMAULIPAS & MEXICO A Thesis by WOODS WILKINSON ALLEN JR Approved...

Allen, Woods Wilkinson

2012-06-07

104

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

105

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

106

Microfluidics Gas Dynamic Virtual Nozzle  

NASA Astrophysics Data System (ADS)

The Gas Dynamic Virtual Nozzle (GDVN) is a microscopic liquid droplet injector that utilizes a gas focusing sheath to run a continuous supply of hydrated bioparticles in vacuum across a pulsed X-ray beam. Its ability to run for days without clogging make it an ideal injector for next-generation biological imaging techniques such as serial femtosecond crystallography (SFX). We report a new approach to nozzle fabrication that has significantly extended the injector's capabilities. Soft photolithography was used to produce a microfluidics version that is comparable to the standard GDVN but capable of subsonic operation and fast fluid switching -- desirable features for increasing data yield by reducing wasted sample.

Nelson, Garrett; Camacho-Alanis, Fernada; Spence, John; Weierstall, Uwe; Ros, Alexandra; Doak, Bruce

2012-10-01

107

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

108

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.

2012-04-27

109

Petrologic Constraints on Seismic Velocity Variations in the Upper Mantle Beneath Southern Africa  

NASA Astrophysics Data System (ADS)

Three-dimensional tomographic images of seismic velocity perturbations obtained from analyses of P-wave and S-wave data from the southern Africa seismic experiment show that seismic velocities are about 0.5 to 1.0% higher in the upper mantle beneath Archean cratons relative to the upper mantle off-craton and in modified craton. We examine these seismic velocity perturbations quantitatively in terms of mineralogical and petrological constraints, including depth and temperature of origin, obtained from more than 100 well-characterized mantle samples in kimberlite pipes both on and off craton. We use laboratory-determined bulk and shear moduli, as well as their temperature and pressure derivatives, to compute the seismic properties of the mineral aggregates at the estimated depths and temperatures in the mantle from which the samples were derived. Xenolith samples from the Kaapvaal craton are organized by petrologic subgroups: (1) low temperature garnet lherzolites and harzburgites that originate predominantly from depths in the range 100-150 km; (2) high temperature garnet lherzolites originating at depths in excess of 170 km; and (3) spinel lherzolites and harzburgites that are thought to comprise a continuous upper layer (depth < 80 km) of the cratonic lithosphere. Off-craton peridotites of Proterozoic age (ca 1-2 Ga) are typically more fertile (enriched in Al, Ca, and Fe) than on-craton samples, and they tend to lie on a mantle geotherm displaced toward higher temperatures. All of the mantle samples used in the present study consist dominantly of olivine and orthopyroxene, with or without lesser amounts of garnet, clinopyroxene, and spinel. P and S wave velocities are computed for each xenolith sample based on the modal proportions and chemical composition of individual mineral phases. Where possible, each velocity determination is corrected for the pressure and temperature at which the sample was in equilibrium in the mantle. A significant uncertainty in the velocity determinations results from an incomplete, and in some cases inconsistent, elasticity database. Notably absent from the database are a number of temperature derivatives, many compositional and second-order derivatives, and virtually all P-T cross-derivatives. Within the limits of these uncertainties, however, we have selected a representative set of elastic parameters that we apply uniformly to all specimens of the xenolith suite for the computation of seismic velocities. The contributions of varying mineral modes, phase compositions, and geothermal gradient to seismic velocity variations are examined in the terms of observed velocity perturbations across southern Africa. We evaluate the relative importance of the geothermal gradient vs. average rock composition of the upper mantle as factors in producing the seismic velocity variations observed between regions that are on-craton, off-craton, and in disturbed craton.

James, D. E.; Carlson, R. W.; Boyd, F. R.; Janney, P. E.

2001-05-01

110

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

111

Linking Petrology and Seismology at an Active Volcano  

NASA Astrophysics Data System (ADS)

Many active volcanoes are continuously monitored through a variety of techniques including seismicity and gas emissions looking for signs of unrest that may signal an impending eruption. One of the enduring challenges is to link the monitored signal to the actual magmatic processes. This is complicated as a magma sample can only be obtained through a subsequent volcanic eruption. Crystals grown within the sub-volcanic plumbing system have the potential to preserve a record of the evolving magma within their crystal structure from nucleation to eruption. Perturbations within the magma system, such as change in temperature, water content or magma mixing causes renewed crystal growth of a different composition creating zoned crystals. Chemical fingerprinting of individual crystal zones allow us to decipher the magmatic processes that created the zonation. Importantly, diffusion chronometry (relaxation of elements across compositional interfaces) enables us to calculate timescales of magmatic perturbations within the magma chamber prior to eruption. Applying these techniques to recent well-characterised eruptions with well-known eruption dates for samples enables us to calculate a petrological time series that can be correlated with geophysical constrained time series form the same eruption to ascertain links to pre-eruptive processes. Mount St. Helens produced a series of well-studied eruptions and characterised eruptions between 1980-1986. From nine of these eruptions, over 500 orthopyroxene crystals were interrogated through a combination of high-resolution imaging and chemical fingering by scanning electron microscopy and electron probe microanalyser respectively. Multiple crystal populations were observed of both unzoned and zoned orthopyroxene with no distinct chemical heterogeneities between these two populations. Zoned crystals were further subdivided into: (1) normally zoned crystals (Fe-rich rims); (2) reversed zoned crystals (Mg-rich rims); (3) multiple zoned crystals and; (4) patchy zoned crystals. Diffusion chronometry indicates both Fe-rich and Mg-rich rims grew simultaneously and generally within two years prior to eruption. Peaks in crystallisation are correlative with peaks in seismicity and gas emissions. Establishing that important but elusive evidence that clearly shows a relationship between seismicity and magma movement and shows that geophysical monitoring techniques do record an accurate arrival of magma pulses. Such a correlation as shown in this study strongly suggests that petrologic time series from ancient or recently re-active volcanic centres where monitoring is limited can provide fundamental insights in pass volcanic activity and can be used to help with mitigation for future eruptions.

Saunders, K.; Blundy, J.; Dohmen, R.; Cashman, K.

2012-12-01

112

Adaptive Scanning Optical Microscope A multidisciplinary optical microscope  

E-print Network

Adaptive Scanning Optical Microscope (ASOM): A multidisciplinary optical microscope design, the optical microscope remains one of the most important tools for observing below the threshold of the naked of view. This paper presents a new optical microscope design that combines a high speed steering mirror

Wen, John Ting-Yung

113

Virtual Laboratories  

E-print Network

At the frontier of most areas in science, computer simulations play a central role. The traditional division of natural science into experimental and theoretical investigations is now completely outdated. Instead, theory, simulation, and experimentation form three equally essential aspects, each with its own unique flavor and challenges. Yet, education in computational science is still lagging far behind, and the number of text books in this area is minuscule compared to the many text books on theoretical and experimental science. As a result, many researchers still carry out simulations in a haphazard way, without properly setting up the computational equivalent of a well equipped laboratory. The art of creating such a virtual laboratory, while providing proper extensibility and documentation, is still in its infancy. A new approach is described here, Open Knowledge, as an extension of the notion of Open Source software. Besides open source code, manuals, and primers, an open knowledge project provides simulated dialogues between code developers, thus sharing not only the code, but also the motivations behind the code.

Piet Hut

2006-10-07

114

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

115

A virtual reality installation  

Microsoft Academic Search

This article presents a virtual reality installation similar to a CAVE based system but less expensive and easily transportable. Like any virtual reality system else, our installation aims to immerse a user in a virtual environment. Hence, we especially focus on the userpsilas feeling of presence which means the user should be able to feel the presence of the virtual

F. de Sorbier; P. Bouvier; A. Herubel; P. Chaudeyrac; V. Biri; J. Kiss

2008-01-01

116

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

117

Virtual PCR  

SciTech Connect

The polymerase chain reaction (PCR) stands among the keystone technologies for analysis of biological sequence data. PCR is used to amplify DNA, to generate many copies from as little as a single template. This is essential, for example, in processing forensic DNA samples, pathogen detection in clinical or biothreat surveillance applications, and medical genotyping for diagnosis and treatment of disease. It is used in virtually every laboratory doing molecular, cellular, genetic, ecologic, forensic, or medical research. Despite its ubiquity, we lack the precise predictive capability that would enable detailed optimization of PCR reaction dynamics. In this LDRD, we proposed to develop Virtual PCR (VPCR) software, a computational method to model the kinetic, thermodynamic, and biological processes of PCR reactions. Given a successful completion, these tools will allow us to predict both the sequences and concentrations of all species that are amplified during PCR. The ability to answer the following questions will allow us both to optimize the PCR process and interpret the PCR results: What products are amplified when sequence mixtures are present, containing multiple, closely related targets and multiplexed primers, which may hybridize with sequence mismatches? What are the effects of time, temperature, and DNA concentrations on the concentrations of products? A better understanding of these issues will improve the design and interpretation of PCR reactions. The status of the VPCR project after 1.5 years of funding is consistent with the goals of the overall project which was scoped for 3 years of funding. At half way through the projected timeline of the project we have an early beta version of the VPCR code. We have begun investigating means to improve the robustness of the code, performed preliminary experiments to test the code and begun drafting manuscripts for publication. Although an experimental protocol for testing the code was developed, the preliminary experiments were tainted by contaminated products received from the manufacturer. Much knowledge has been gained in the development of the code thus far, but without final debugging, increasing its robustness and verifying it against experimental results, the papers which we have drafted to share our findings still require the final data necessary for publication. The following sections summarize our final progress on VPCR as it stands after 1.5 years of effort on an ambitious project scoped for a 3 year period. We have additional details of the methods than are provided here, but would like to have legal protection in place before releasing them. The result of this project, a suite of programs that predict PCR products as a function of reaction conditions and sequences, will be used to address outstanding questions in pathogen detection and forensics at LLNL. VPCR should enable scientists to optimize PCR protocols in terms of time, temperature, ion concentration, and primer sequences and concentrations, and to estimate products and error rates in advance of performing experiments. Our proposed capabilities are well ahead of all currently available technologies, which do not model non-equilibrium kinetics, polymerase extension, or predict multiple or undesired PCR products. We are currently seeking DHS funding to complete the project, at which time licensing opportunities will be explored, an updated patent application will be prepared, and a publication will be submitted. A provisional and a full patent application have already been filed (1).

Gardner, S N; Clague, D S; Vandersall, J A; Hon, G; Williams, P L

2006-02-23

118

Microscopic mass estimations  

E-print Network

The quest to build a mass formula which have in it the most relevant microscopic contributions is analyzed. Inspired in the successful Duflo-Zuker mass description, the challenges to describe the shell closures in a more transparent but equally powerful formalism are discussed.

Jorge G. Hirsch; Joel Mendoza-Temis

2010-03-09

119

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

120

Petrology of fine-grained rock fragments and petrologic implications of single crystal from the Luna 20 soil.  

NASA Technical Reports Server (NTRS)

Only fine-grained rocks are present in the Luna 20 samples, and coarser-grained rocks are represented by fragments of single crystals. A petrologic study has been made of 47 fine-grained crystalline rocks, microbreccias, and glassy aggregates. In addition, a total of 33 single crystals of pyroxene, plagioclase, olivine, and spinel, in the size range from 125 to 500 microns, have been examined using electron microprobe and single-crystal X-ray diffraction techniques. The most abundant fine-grained crystalline rocks in the samples examined are recrystallized anorthositic norite and anorthositic troctolite. Gabbroic rocks, anorthosite, and KREEP basalt are present but not common. Most of the single crystals of pyroxene and plagioclase could have been derived from coarser-grained noritic, troctolitic, and anorthositic rocks. However, three of the 14 pyroxene crystals, and two of the five olivine crystals have Fe/(Fe + Mg) contents greater than 0.45 and are believed to have been derived from mare basalts or related rocks.

Cameron, K. L.; Papike, J. J.; Bence, A. E.; Sueno, S.

1973-01-01

121

Complete and rapid switch from light microscopy to virtual microscopy for teaching medical histology.  

PubMed

During the interim between the 2003 and 2004 academic years, the cell and tissue biology and integrated medical neuroscience courses at the Medical College of Wisconsin made a complete and rapid switch from light microscopy- to virtual microscopy-based histology laboratories. This switch was prompted by the difficulties in maintaining and the cost of replacing the college's microscopes and microscope slides, and primarily by the desire to promote and streamline learning for our large classes (n > 200) of first-year medical students. A group of students who used the virtual microscope, another group of students who used the light microscope, and faculty with experience using both tools rated the effectiveness of the virtual microscope for learning and teaching. Also, to determine whether virtual microscopy affected student learning, laboratory examination scores for the 2004 class (n = 209) were compared with those of four previous classes that used light microscopes exclusively (n = 811). The switch from light microscopy to virtual microscopy was very favorably received by both students and faculty. More importantly, data from examination scores and course evaluation surveys indicated that use of the virtual microscope may significantly improve student performance and learning efficiency. Procedures for successfully implementing this change are described. PMID:16032757

Krippendorf, Beth B; Lough, John

2005-07-01

122

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

123

Slide2Go: A virtual slide collection for pathology education.  

PubMed

Slide2Go is a collection of digitized glass slides on the Web from a pathology departments slide set for second year medical students. The virtual slide collection can be accessed anywhere using any Web browser with Adobe Flash Player. It simulates the experience of viewing a glass slide under an optical microscope. Rare and unusual cases can be preserved and shared worldwide. Medical education can be enhanced by virtual slides. PMID:18694018

Conran, Richard; Fontelo, Paul; Liu, Fang; Fontelo, Marie; White, Elizabeth

2007-01-01

124

Refining a Proposal to Build Data-Rich Rock Suites for Learning Petrology  

NASA Astrophysics Data System (ADS)

One of the outcomes from the 2003 Teaching Petrology workshop held in Bozeman, MT was a call for the development of a series of data-rich rocks suites that could be used to help students learn fundamental petrologic processes and concepts such as partial melting, magmatic differentiation, and phase equilibria. These suites would include detailed field, structural, geochemical, and geochronologic data that could be used in short lecture demonstrations, laboratory exercises, multi-week activities or semester-long projects. The motivation behind the development of these suites is the growing understanding in the education community that hands-on, problem-based learning activities that allow students to build their own knowledge are more effective than most traditional lecture formats. In discovery-based environments students learn to pose questions, work with data, manage ambiguity, and synthesize diverse observations. Many existing rocks suites used in petrology courses consist of rocks that were not necessarily selected to facilitate learning of important petrologic processes, or to develop higher order skills in a discovery-based setting. Our proposal is to develop a collection of genetically related rocks that can be used to discover fundamental petrologic concepts through guided data collection, interpretation, and synthesis by students and faculty. The use of suites in this manner helps develop a "community of learners" atmosphere in a course, where the outcome is perhaps not well defined and could change from year to year depending on the interests of the students and faculty involved. In addition, we hope these suites will be developed and used by several institutions, thus modeling the process of modern research by promoting sharing of equipment, data, ideas, and expertise perhaps through the use of a dedicated web site for each suite. This abstract solicits interest in and feedback from the community on the development of a series of data-rich rock suites and curricula for learning petrology.

Wirth, K. R.; Davidson, C.; Creasy, J. W.

2003-12-01

125

History of applied coal petrology in the United States  

Microsoft Academic Search

Bethlehem Steel maintained a coal petrography laboratory in its Research Department from late 1962 until 1985. The primary goals of the laboratory were to develop an accurate method for analyzing the microscopic composition of the coals used by Bethlehem and to correlate that analysis with the various tests of coking quality and coking behavior, thus providing a predictive capability from

Richard R Thompson

2000-01-01

126

The Transmission Electron Microscope  

Microsoft Academic Search

\\u000a A typical commercial transmission electron microscope (TEM) costs about 5 for each electron volt (eV) of energy in the beam and, if you add on all available options, it can easily cost up to5 for each electron volt (eV) of energy in the beam\\u000a and, if you add on all available options, it can easily cost up to 10 per

David B. Williams; C. Barry Carter

127

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

128

Scanning Electron Microscope - SEM  

NSDL National Science Digital Library

This website is from Boston Museum of Science and is an introduction to Scanning Electron Micrscope (SEM). It contains an image gallery of insects, plants and other items as seen with an SEM. A slide show and a movie explains how the microsope works. Teacher resources offer guidance on building your own microscope and setting up a lab, including wet mounts and staining cells. Information on how the Museum uses the scope, and additional electronic resources, completes the site.

129

Thermal Lens Microscope  

NASA Astrophysics Data System (ADS)

We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/?m2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

2000-09-01

130

Virtual Pediatric Hospital  

MedlinePLUS

... PediatricEducation.org | GeneralPediatrics.com | Pediatric Commons Virtual Pediatric Hospital is a digital library of pediatric information and ... information for all students of medicine Virtual Naval Hospital - a digital library of naval medicine and military ...

131

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

132

Exploring virtual ecosystems  

Microsoft Academic Search

Browsing In Time & Space (BITS) is an interface designed to explore virtual ecosystems. A virtual ecosystem includes a three dimensional terrain model background, collections of man-made and natural objects, and behavior and interaction rules between the objects and the background. BITS is based on a virtual notepad and pen metaphor and is inspired in the concept of logging. Physical

Antão Vaz Almada; António Eduardo Dias; João Pedro Silva; Emanuel Marques dos Santos; Pedro José Pedrosa; António Sousa Câmara

1996-01-01

133

Papous: The Virtual Storyteller  

Microsoft Academic Search

This paper describes the development of P apous, a Virtual Storyteller. Our ultimate goal is to obtain a synthetic character that tells stories in an expressive and believable way, just as a real human storyteller would do. In this paper we describe the first version of Papous, our virtual storyteller. Papous can be seen as a virtual narrator who reads

André Silva; Marco Vala; Ana Paiva

2001-01-01

134

Dynamic Virtual Private Networks  

Microsoft Academic Search

We extend traditional Virtual Private Networks (VPNs) with fault-tolerance and dynamicmembership properties, defining a Dynamic Virtual Private Network (DVPN). We require nonew hardware and make no special assumptions about line security. An implementation exhibitslow overheard, provides guarantees of authenticity and confidentiality to any IP applicationrunning over the virtual network. Our system is lightweight, allowing the use of multiple finegrainedVPNs. Instead

Ohad Rodeh; Ken Birman; Mark Hayden; Danny Dolev

1998-01-01

135

Petrology and Geochemistry of Volcan Darwin, Isabela Island, Galapagos Archipelago  

NASA Astrophysics Data System (ADS)

The Galapagos Islands represent a hotspot system where the distribution and number of simultaneously active volcanoes, their petrologic and morphologic diversity, and the lack of a chemical evolutionary pattern distinguish them from the more familiar example of Hawaiian hotspot volcanism. The large western Galapagos shield volcanoes share many geomorphic and chemical attributes, yet in detail each is unique. 88 new major and trace element analyses document that Volcan Darwin, one of the large shield volcanoes of Isabela island, has erupted a range of compositions from basalt to andesite. The diverse compositions of Darwin are unlike those of the neighboring volcanoes of Wolf and Alcedo. On average, lavas of Darwin and Alcedo are much more highly evolved than the lavas of Wolf. For example, at Darwin, total alkalies (K2O+Na2O) range from 2.5 to 4.6 wt percent, SiO2 ranges from 47.6 to 57.0 wt percent and MgO ranges from 2.9 to 6.2 wt percent. Geochemical modeling shows that this compositional range is due mostly to crystal fractionation involving olivine, plagioclase and clinopyroxene. Petrographically, the population of Darwin lavas are strongly bimodal. Eighty percent of the samples collected are extremely crystal-rich and contain up to forty percent plagioclase phenocrysts and zoned megacrysts up to 8 mm in diameter. Conversely, about twenty percent of the samples collected are aphyric or only sparsely phyric. These differences in crystallinity and the occurrence of highly evolved compositions suggest that the thermal flux and residence times for Darwin's magmas are highly variable. We believe that at Darwin, as has been shown for other Galapagos volcanoes, most batches of magma are mixed in a large, thermally regulated chamber which commonly results in the eruption of very uniform tholeiitic basalt. However, the structure and longevity of Darwin's lithospheric storage and transport system must be highly variable, as some isolated magmas have cooled and evolved to much greater degrees than most Galapagos magmas, resulting in the eruption of andesite.

Naumann, T. R.; Krebs, L. K.

2003-12-01

136

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

137

Low frequency acoustic microscope  

DOEpatents

A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

Khuri-Yakub, Butrus T. (Palo Alto, CA)

1986-11-04

138

Idea Bank: Microscopic Impressionism  

NSDL National Science Digital Library

Claude Monet meets the world of science through Histro-Art, a concept that was conceived from the impressions of an 11th and 12th-grade college preparatory human anatomy and physiology class who were studying histology using a micro-video system. As they observed a slide of smooth muscle, one student noticed the resemblance to impressionist art, and thus the concept was born. In this engaging activity, students observe microscopic slide tissue and interpret impressionism theory using various mediums to create their own art pieces. It is sure to leave them with a lasting "impression" of the connection between art and science.

Reitnauer, John

2005-04-01

139

Scanning Electron Microscope  

NSDL National Science Digital Library

As part of the Science Learning Network, the Scanning Electron Microscope (SEM) Web site explores what an SEM is, how it's used, and what images it can produce. The How It Works section has a self-paced tutorial and an interesting movie describing how it functions as well. The other section for students is the image gallery, which has the Animal, Vegetable, Mineral game. Individual images from a SEM are shown, and users get to guess which of the three substances is shown. It isn't as easy as it sounds, but it is fun.

1998-01-01

140

Atomic Force Microscope  

SciTech Connect

The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

Day, R.D.; Russell, P.E.

1988-12-01

141

Parts of the Microscope and Their Function  

E-print Network

Parts of the Microscope and Their Function #12;Rules of using a microscope Always carry with 2 of the cords #12;Parts of a microscope #12;Parts of a microscope Eyepiece #12;Parts of a microscope Body tube #12;Parts of a microscope Nosepiece #12;Parts of a microscope Objectives Low power (short) High

Rose, Michael R.

142

Electrical conductivity of continental lithospheric mantle from integrated geophysical and petrological modeling  

E-print Network

and petrological modeling: Application to the Kaapvaal Craton and Rehoboth Terrane, southern Africa J. Fullea,1 M Kaapvaal Craton and the Proterozoic Rehoboth Terrane, in southern Africa, integrating different geophysical that to fit the measured magnetotelluric responses in both the Kaapvaal and Rehoboth terranes, the uppermost

Jones, Alan G.

143

A Petrologic and bulk Chemical Characterization of the Unequilibrated Ordinary Chondrite Northwest Africa 5717  

NASA Astrophysics Data System (ADS)

We examine the chemical group affinities of Northwest Africa 5717 (Type 3.05) in terms of its petrologic and bulk chemical characteristics and test its apparent dual lithology. Preliminary data suggest it to be related to L- and LL-chondrites.

Bigolski, J. N.; Friedrich, J. M.; Weisberg, M. K.; O'Keefe, M.-C.

2014-09-01

144

Geochemical and petrological evidence for subduction^ accretion processes in the Archean Eastern Indian Craton  

E-print Network

Geochemical and petrological evidence for subduction^ accretion processes in the Archean Eastern^late Archean sandstones from the Eastern Indian Craton show that the sedimentary rocks were derived from of these sandstones demonstrate an overall similarity with global Proterozoic^Archean sandstones, including strong Nb

Garzione, Carmala N.

145

Lithospheric petrology of the eastern Arabian Plate: Constraints from Al-Ashkhara (Oman) xenoliths  

E-print Network

Lithospheric petrology of the eastern Arabian Plate: Constraints from Al-Ashkhara (Oman) xenoliths, Oman b Geosciences Dept., U. Texas at Dallas Richardson, TX 75083-0688, USA a b s t r a c ta r t i c l November 2011 Keywords: Arabian Plate Oman Xenoliths Lherzolite Lithosphere Lower crust Mafic granulite

Stern, Robert J.

146

CENTRAL AMERICA: GEOLOGY, RESOURCES AND HAZARDS; BUNDSCHUH & ALVARADO (EDS) 1 Petrology and geochemistry of lavas  

E-print Network

CENTRAL AMERICA: GEOLOGY, RESOURCES AND HAZARDS; BUNDSCHUH & ALVARADO (EDS) 1 Chapter 22 Petrology variations in Cenozoic calc- alkaline suites of Central America. Intern. Upper Mantle Sci. Rept. 16, 1969. 22 from the Middle America trench (MAT). The front consists of 39 distinct centers or clusters of vents

147

PetroGraph: A new software to visualize, model, and present geochemical data in igneous petrology  

Microsoft Academic Search

A new software, PetroGraph, has been developed to visualize, elaborate, and model geochemical data for igneous petrology purposes. The software is able to plot data on several different diagrams, including a large number of classification and “petrotectonic” plots. PetroGraph gives the opportunity to handle large geochemical data sets in a single program without the need of passing from one software

M. Petrelli; G. Poli; D. Perugini; A. Peccerillo

2005-01-01

148

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

E-print Network

Petrology and geochemistry of a diamondiferous lherzolite from the Premier diamond mine, South of a diamondiferous peridotite xenolith from the Premier diamond mine in South Africa. The xenolith is altered of a diamondiferous peridotite from the Premier diamond mine. Such xenoliths are surprisingly rare on the Kaapvaal

Cartigny, Pierre

149

Petrology and Geochemistry of Lunar Meteorite Abar al'Uj 012  

NASA Astrophysics Data System (ADS)

The petrology and geochemistry of Abar al’Uj 012, a feldspathic lunar meteorite found in Saudi Arabia is described. The meteorite is a vesicular crystalline impact-melt breccia, which lacks a fusion crust and has a ferroan anorthosite affinity.

Mészáros, M.; Hofmann, B. A.; Korotev, R. L.; Gnos, E.; Greber, N.; Greenwood, R. C.

2014-09-01

150

A new petrological and geophysical investigation of the present-day plumbing system of Mount Vesuvius  

Microsoft Academic Search

A model of the electrical resistivity of Mt. Vesuvius has been elaborated to investigate the present structure of the volcanic edifice. The model is based on electrical conductivity measurements in the laboratory, on geophysical information, in particular, magnetotelluric (MT) data, and on petrological and geochemical constraints. Both 1-D and 3-D simulations explored the effect of depth, volume and resistivity of

A. Pommier; P. Tarits; S. Hautot; M. Pichavant; B. Scaillet; F. Gaillard

2010-01-01

151

Sedimentary Petrology Field Trip to Gravel Quarry near Rotterdam Junction, NY  

NSDL National Science Digital Library

This is a Stratigraphy Sedimentary Petrology field trip stop at an exceptional glacial outwash gravel quarry, where students measure, identify and count clast types, measure cross-bedding directions, and examine the early stages of lithification of gravel to conglomerate. The gravel deposits are also representative of the local surficial aquifer material that lies nearby in the subsurface.

Ryberg, Paul

152

Temperature of mantle melts beneath Central America: Integrating petrologic and seismic observations  

Microsoft Academic Search

Mantle melting beneath volcanic arcs is likely polybaric and polythermal, driven by a combination of decompression and hydration. Here we integrate petrologic and seismic observations to constrain the temperature and water content of the bulk melt and the hot zone within the mantle wedge. Results from the TUCAN seismic experiment in Central America show a vertical region, from 150-50 km,

T. Plank; C. Rychert; K. Fischer; G. Abers; E. Syracuse

2007-01-01

153

[Virtual microscopy in pathology teaching and postgraduate training (continuing education)].  

PubMed

As with conventional microscopy, virtual microscopy permits histological tissue sections to be viewed on a computer screen with a free choice of viewing areas and a wide range of magnifications. This, combined with the possibility of linking virtual microscopy to E-Learning courses, make virtual microscopy an ideal tool for teaching and postgraduate training in pathology. Uses of virtual microscopy in pathology teaching include blended learning with the presentation of digital teaching slides in the internet parallel to presentation in the histology lab, extending student access to histology slides beyond the lab. Other uses are student self-learning in the Internet, as well as the presentation of virtual slides in the classroom with or without replacing real microscopes. Successful integration of virtual microscopy depends on its embedding in the virtual classroom and the creation of interactive E-learning content. Applications derived from this include the use of virtual microscopy in video clips, podcasts, SCORM modules and the presentation of virtual microscopy using interactive whiteboards in the classroom. PMID:18843489

Sinn, H P; Andrulis, M; Mogler, C; Schirmacher, P

2008-11-01

154

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

155

Forensic Scanning Electron Microscope  

NASA Astrophysics Data System (ADS)

The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

Keeley, R. H.

1983-03-01

156

Cosmic petrology and the planetary evolution of the Solar System  

NASA Astrophysics Data System (ADS)

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 latter relates these meteorites to the planetary evolutions of the Solar System. This evolution started with the origin of the giant planets via the accretion of water hydrogen icy (‘cometary’) planetesimals simultaneously with the accumulation of the Sun's mass. They underwent contraction with the release of energy sufficient for their complete melting and subsequent differentiation into giant fluid envelopes and chondritic cores. The iron silicate differentiation of the latter brought about the magnetic fields of the giant planets. The Sun evolved even further and, upon reaching its stellar state, began actively to affect the surrounding planetary system and induced the dissipation of the dense interplanetary nebula in space. This process gave rise to the rapid rotation of the giant planets. The influence of the Sun on the giant planets caused the surface migration of hydrogen, a process accompanied by the acceleration of the rotation and, as a consequence, the separation of satellites under the effect of centrifugal forces. This glaringly manifests the deceleration of the planetary evolution with increasing distance from the Sun. This effect was at a maximum on the near-Sun giant planets, which have lost their fluid envelopes, so that their cores were transformed into independent terrestrial planets simultaneously with the loss of their satellite systems. The preserved relics of these systems are the Moon of the Earth, and Phobos and Deimos of Mars. They provide evidence of the very old age of the near-Sun terrestrial protoplanets, in contrast with the relatively young ages of satellites of the giant planets belonging to the Jovian group. The Moon is one of the oldest known satellites in the Solar System. Volcanic activity on the Moon has an age of 4.6 3.2 Gyears, whereas its analogue Io (a satellite of Jupiter) is now characterized by the culmination of its volcanic activity. Volcanic events on the satellites of the giant planets and on the terrestrial planets are some of the most conspicuous manifestations of their endogenic activity, which is caused by the fluid state of these molten cores, generating magnetic fields. This activity was lost by planets when their consolidation was completed. The duration of the endogenic activity of planets was predetermined by their protoplanetary evolution in the form of the cores of their parent giant planets. In this sense, the Earth is a unique planet, whose endogenic activity has already lasted for 4.6 Gyears, whereas the Earth's core is now less than 50% consolidated. This makes the Earth different in a major way from the rest of the terrestrial planets (Mercury, Venus and Mars), whose endogenic evolution terminated at a primitive stage because of the loss of their fluid components as a result of complete consolidation, which was coupled with the loss of their magnetic fields. There are good reasons to believe that the Earth had completely differentiated under the tremendous pressure of the fluid shell of its parental planet (Proto-Earth), and this predetermined the huge reserves of fluid components stored in its liquid core. At the same time, the differentiation of the other terrestrial planets was associated with the loss of the fluid shells of their parental protoplanets. The effect of parent protoplanets was even weaker in the states of the satellite planets, which lost their fluid shells and differentiated in space vacuum, a process that was responsible for the low reserves of fluid components in their molten iron cores and, correspondingly, their relatively short-lived endogenic activity (1.4 Gyears). The endogenic activity of iron stony planets is cau

Marakushev, A. A.

2005-12-01

157

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

158

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

159

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

160

Virtual Five Animals Exercise  

Microsoft Academic Search

\\u000a Virtual Five Animals Exercise is an interactive game which is an important part of Virtual Olympic Museum for the Games of\\u000a the XXIX Olympiad. Users can learn and imitate Five Animals Exercise without any interactive device. To do these, we make\\u000a use of motion capture data to drive the virtual human motion, and use template matching method to recognize users’

Yue Qi; Xu-kun Shen; Qin-ping Zhao

2006-01-01

161

Epi-Fluorescence Inverted Microscope (Zeiss,  

E-print Network

Epi-Fluorescence Inverted Microscope (Zeiss, Observer Z1) April 2013 #12;Start Up cont. · Turn on the microscope power supply · Press the ON/OFF button on the microscope to turn on the microscope control panel the power switch). · Press "Microscope" on the small touchscreen to setup the microscope settings

Subramanian, Venkat

162

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

163

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

164

A Microscopic Information System (MIS) to assist in petrographic analysis  

NASA Astrophysics Data System (ADS)

Rock texture results from all the petrological processes that have affected the rock system. The interpretation of a rock texture relies on the analysis of the morphometric parameters of the constituting components (e.g. crystals or grains). A consistent and statistically sound quantification of components size and shape is crucial to adequately unravel the petrology of a rock, but the gathering of these measurements may be time-consuming or difficult to achieve using low-cost facilities. The basic technique for texture analysis of rocks is the observation of thin sections in transmitted light by using a petrographic microscope. To automate and speed-up textural measurements from thin section in transmitted light, several image processing procedures have been published in the last two decades. Nevertheless, the complexity of the optical properties of crystals hampered the determination of a method that is completely satisfactory, especially for complex polymineralic plutonic rocks. This work provides a contribution to solve this problem. We present a novel composite procedure based on four approaches: i) the use of a slide scanner to acquire the input imagery in transmitted light from thin sections without using the petrographic microscope; ii) the storage of the resulting images in a GIS-like database structure that is extremely useful to retrieve, browse and analyze a large archive of images from a high number of thin sections; iii) the application of a custom image analysis procedure based on two region growing functions; iv) the refinement of the regions after raster to vector conversion using GIS software. We call the obtained analysis system a Microscopic Information System (MIS), because it relies on GIS software but it is not a geographic system. In this study we apply this technique to analyze 137 thin sections obtained from 49 samples of 8 different granitoid rocks that are commonly used in the decorative stone industry. For each thin section 5 collimated RGB images are scanned: 4 under different direction of crossed polarization and 1 without polarization. The input device warrants a pixel of 9.4 microns. Two image processing functions (a seeded and an unseeded ones) work on a multi-band selection of the input imagery to account for the most represented intra-crystalline colour patterns observed in the minerals constituting the samples (plagioclase, quartz, K-feldspar and femic minerals). The flexible multi-format data visualization provided by GIS software offers an improved working environment compared to standard image processing units. This system can also substitute the petrographic microscope in performing a preliminary thin section survey. This method provides accurate measurements using an inexpensive device and proved to be fast, reliable and flexible. Once tuned, it has been successfully applied to all the analysed thin sections without further calibrations. The obtained measurement database is constituted by the morphometric measurements of about 87,000 crystals. The GIS structure of this database makes easy the analysis of the obtained results allowing an instant visualization of the outcomes of morphometric or modal queries over any selection of samples.

Tarquini, S.; Favalli, M.

2009-04-01

165

Video: Focusing a Compound Microscope  

NSDL National Science Digital Library

This video from CUNY Kingsborough Community College describes how to focus a compound microscope. The brief clip, available for viewing on YouTube, would be most useful for students with a basic understanding of the parts of a compound microscope and how to use it. Running time for the video is 0:55.

2013-07-01

166

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

167

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

168

Presence in Virtual Theater  

Microsoft Academic Search

Using empirical data, this research suggests that key features of a typical theatrical rehearsal process can significantly improve the sense of presence for participants within a shared virtual environment. Research of shared virtual environments (VEs) for the production of theater shows suggests that theater applications have specific requirements for presence. These can be summarized as characterization, repetition, and group dynamic,

Carlton Reeve

2000-01-01

169

Virtual Reality Registration  

E-print Network

registration7on a frame-by-frame basis. The figure shows a computer- generated television antenna registered;2 Experimentalaugmented reality system showing dynamic registration of a virtual antenna and annotation arrow that appearVirtual Reality I Dynamic Registration Correction in Augmented Reality Systems ugmented reality (AR

Shahabi, Cyrus

170

Who Benefits from Virtuality?  

ERIC Educational Resources Information Center

Discusses the use of constructivist frameworks to develop effective and successful learning environments, including educational software. Topics include technology supporting reform; virtuality and multimedia; attributes of interactive multimedia and virtual reality; and examples of context and learner active participation. (Contains 35…

Harper, Barry; Hedberg, John G.; Wright, Rob

2000-01-01

171

Virtual Organizations Matei Ripeanu  

E-print Network

, data sets, analysis tools, sensors, and scien- tific instruments. The sharing policies that govern by optical links that the TeraGrid (www.teragrid.org) de- ploys to support several virtual organi- zations neglect: risk analysis for contract drafting and support throughout the virtual organization life cycle

Vazhkudai, Sudharshan

172

Virtual orthopedic surgery training  

Microsoft Academic Search

Medicine is one of the most promising areas for emerging computer graphics and virtual reality techniques. VR training simulators let surgeons practice on virtual body tissue and get the same feedback they would experience in performing a real operation. Hybrid VR systems permit medical practitioners to view the patient overlaid with 3D data sets derived from 3D scanners, thus providing

A. Sourin; O. Sourina; Howe Tet Sen

2000-01-01

173

Virtual Reality in Healthcare  

Microsoft Academic Search

In our modern 21st century, daily life would be unthinkable without computers. Multimedia and virtual reality are useful for\\u000a people with special needs. This chapter presents a general overview of the use of virtual reality in medical informatics,\\u000a rehabilitation and assistive & preventive healthcare.

Cecília Sik Lányi

174

Virtualization Gate Benjamin Petit  

E-print Network

wears a HMD tracked with an infrared positioning system. An off-line calibration process enables limited in the way they can inter- act with virtual objects. Their influence on the 3D world, including-camera 3D modeling, phys- ical simulation and tracked HMD for a full-body immersion and presence in virtual

175

Virtual Reality and Psychotherapy  

Microsoft Academic Search

Virtual Reality (VR) is a new technology consisting on a graphic environment in which the user, not only has the feeling of being physically present in a virtual world, but he\\/she can interact with it. The first VR workstations were designed for big companies in order to create environments that simulate certain situations to train professionals. However, at this moment

Cristina BOTELLA; Soledad QUERO; Rosa M. BAÑOS; Conxa PERPIÑÁ; Azucena GARCÍA PALACIOS

176

Applications of virtual audio  

Microsoft Academic Search

Technology for electronically simulating spatial sound over loudspeakers and headphones has matured in the past few decades to facilitate many new applications of virtual audio. Electronic simulation of directional and distance auditory cues has greatly expanded the areas of application of virtual audio. Some potential aerospace applications include monitoring spatially separated speech communication signals to increase understanding, navigating by an

Mark Ericson; William D'Angelo; Eric Scarborough; Steve Rogers; Philip Amburn; Dennis Ruck

1993-01-01

177

Virtual Scanning Electron Microscopy  

NSDL National Science Digital Library

This site from Florida State University features an interactive Java tutorial that explores various aspects of virtual scanning electron microscopy. Users can see how specimens appear when magnified in the virtual SEM. The site also features an image gallery and extensive information about different types of microscopy.

Davidson, Michael W.; Kunkel, Dennis; Parry-Hill, Matthew J.; University, Florida S.

178

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

179

10 Myths of Virtualization  

ERIC Educational Resources Information Center

Half of servers in higher ed are virtualized. But that number's not high enough for Link Alander, interim vice chancellor and CIO at the Lone Star College System (Texas). He aspires to see 100 percent of the system's infrastructure requirements delivered as IT services from its own virtualized data centers or other cloud-based operators. Back in…

Schaffhauser, Dian

2012-01-01

180

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

181

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

182

Petrology of the ultramafic and basic rocks of betancuria massif, fuerteventura Island (Canarian Archipelago)  

Microsoft Academic Search

The petrological and geochemical aspects of the ultramafic and basic plutonic rocks of Betancuria Massif are examined. The\\u000a rocks consist of gradational varieties of wehrlite, pyroxenite, olivine-gabbro and gabbro formed mainly by magnesium-rich\\u000a olivine, clinopyroxene and plagioclase. The Complex exhibits structures and textures characteristic of layered igneous rocks;i.e., banding, layering, lamination, etc...; rocks are therefore considered as cumulates or magmatic

P. Gastesi

1969-01-01

183

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

184

Geology and petrology of the lava complex of Young Shiveluch Volcano, Kamchatka  

Microsoft Academic Search

Detailed geological and petrological-geochemical study of rocks of the lava complex of Young Shiveluch volcano made it possible\\u000a to evaluate the lava volumes, the relative sequence in which the volcanic edifice was formed, and the minimum age of the onset\\u000a of eruptive activity. The lavas of Young Shiveluch are predominantly magnesian andesites and basaltic andesites of a mildly\\u000a potassic calc-alkaline

N. V. Gorbach; M. V. Portnyagin

2011-01-01

185

Virtual Welding Trainers  

NSDL National Science Digital Library

Weld-Ed, the National Center for Welding Education and Training have provided this Power Point presentation entitled âÂÂVirtual Welding Trainersâ that covers the pros and cons of implementing a virtual welding program in education. Virtual welding programs have gained attention in the past years because of a decrease in the welding workforce and increasing workforce performance. This slide show provides a history and examples of virtual reality simulation. There are lists of benefits, like instant feedback and reduced environmental concerns. Also provided are virtual welding development barriers, such as high start-up costs. Last but not least, there is a list of other institutions that are using virtual welding programs.

2009-09-24

186

Fabric and petrological characteristics of serpentinized peridotites from the southern Mariana Trench  

NASA Astrophysics Data System (ADS)

We analysed more than 100 peridotite samples from several sampling points in the southern Mariana Trench-the deepest oceanic trench in the world (10,924±10 m)-to better understand the development of the region. Petrological characteristics indicate the presence of two types of peridotites: those with a backarc origin (Site 1, ~144° E) and those from the forearc (Site 2, ~143.5E and Site 3, ~143E). The peridotites show petrological evidence for intense interaction with magma and/or fluid. This interaction has not influenced the fabric in the samples. On the basis of fabric intensity, the periodotites from Site 1 (backarc origin) and from the Mariana Trough record similar degrees of deformation, whereas the peridotites from Sites 2 and 3 (forearc origin) underwent lower-temperature deformation than did the serpentine seamounts. The spatial distribution of these petrological and fabric characteristics suggests that the mantle beneath the southern Mariana Trench is heterogeneous. Differences in secondary minerals such as serpentine minerals among the samples may reflect the ascent rate, indicating that the peridotites from Site 1 ascended at a higher rate and were serpentinized at a lower temperature (<250 degree C) compared with those from Sites 2 and 3 (>400 degree C).

Michibayashi, K.; Uehara, S.; Ohara, Y.; Ishii, T.

2011-12-01

187

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

188

Partitionable Virtual Synchrony Extended Virtual Synchrony  

E-print Network

FIFO multicast framework. A natural extension of this idea is to implement one set of group presents several EVS algorithms for implementing a partitionable Virtual Synchrony (VS) model of group communication. It first explicitly defines the VS and EVS models through the presentation of their safety

Amir, Yair

189

Partitionable Virtual Synchrony Extended Virtual Synchrony  

E-print Network

multicast framework. A natural extension of this idea is to implement one set of group communication presents several EVS algorithms for implementing a partitionable Virtual Synchrony (VS) model of group communication. It first explicitly defines the VS and EVS models through the presentation of their safety

Amir, Yair

190

Virtual assembly using virtual reality techniques  

Microsoft Academic Search

Virtual reality is a technology which is often regarded as a natural extension to 3D computer graphics with advanced input and output devices. This technology has only recently matured enough to warrant serious engineering applications. The integration of this new technology with software systems for engineering, design, and manufacturing will provide a new boost to the field of computer-aided engineering.

Sankar Jayaram; Hugh I. Connacher; Kevin W. Lyons

1997-01-01

191

Microscopic symmetric bifurcation condition of cellular solids based on a homogenization theory of finite deformation  

Microsoft Academic Search

In this paper, we establish a homogenization framework to analyze the microscopic symmetric bifurcation buckling of cellular solids subjected to macroscopically uniform compression. To this end, describing the principle of virtual work for infinite periodic materials in the updated Lagrangian form, we build a homogenization theory of finite deformation, which satisfies the principle of material objectivity. Then, we state a

N. Ohno; D. Okumura; H. Noguchi

2002-01-01

192

Virtual Human Project  

SciTech Connect

This paper describes the development of a comprehensive human modeling environment, the Virtual Human, which will be used initially to model the human respiratory system for purposes of predicting pulmonary disease or injury using lung sounds. The details of the computational environment, including the development of a Virtual Human Thorax, a database for storing models, model parameters, and experimental data, and a Virtual Human web interface are outlined. Preliminary progress in developing this environment will be presented. A separate paper at the conference describes the modeling of sound generation using computational fluid dynamics and the modeling of sound propagation in the human respiratory system.

Ward, RD

2001-06-12

193

4-H Virtual Farm  

NSDL National Science Digital Library

The 4-H Virtual Farm offers sections on horses, farm pond aquaculture, beef, dairy, poultry, and wheat. Each section has an interview with a producer about their work, information on the industry in Virginia, animations of farm processes, a virtual reality view of a farm, information on what the producers must know and how they use science, explanations of the food chain, a glossary for students to learn to talk like a producer, and a quiz for a chance to win virtual blue ribbons.

194

(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

195

Scanning Probe Microscope Animation Gallery  

NSDL National Science Digital Library

This site, hosted by Nanoscience Instruments, has several animations from a scanning probe microscope (SPM). The topics include such items as atomic resolution, buckyballs and electrochemistry. These are good resources that could be used to explore nanoscience through visual means.

2011-02-23

196

Axiomatic Electrodynamics and Microscopic Mechanics.  

National Technical Information Service (NTIS)

A new approach to theoretical physics, along with the basic formulation of a new MICROSCOPIC MECHANICS for the motion of small charged particles is described in this set of lecture notes. Starting with the classical (Newtonian) mechanics and classical fie...

M. Yussouff

1981-01-01

197

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

198

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.  

... 8 2014-04-01 2014-04-01 false Assisted reproductive microscopes and microscope accessories. 884.6190 Section... Assisted Reproduction Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a)...

2014-04-01

199

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.  

Code of Federal Regulations, 2012 CFR

... 8 2012-04-01 2012-04-01 false Assisted reproductive microscopes and microscope accessories. 884.6190 Section... Assisted Reproduction Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a)...

2012-04-01

200

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.  

Code of Federal Regulations, 2013 CFR

... 8 2013-04-01 2013-04-01 false Assisted reproductive microscopes and microscope accessories. 884.6190 Section... Assisted Reproduction Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a)...

2013-04-01

201

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.  

Code of Federal Regulations, 2010 CFR

... 8 2010-04-01 2010-04-01 false Assisted reproductive microscopes and microscope accessories. 884.6190 Section... Assisted Reproduction Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a)...

2010-04-01

202

21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.  

Code of Federal Regulations, 2011 CFR

... 8 2011-04-01 2011-04-01 false Assisted reproductive microscopes and microscope accessories. 884.6190 Section... Assisted Reproduction Devices § 884.6190 Assisted reproductive microscopes and microscope accessories. (a)...

2011-04-01

203

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

204

MIT Environmental Virtual Campus  

NSDL National Science Digital Library

The MIT Environmental Virtual Campus is an interactive exploration of environmental protection and safety issues on campus. Users navigate different sectors of campus activities for useful information for meeting environmental regulations and ensuring that colleges are sustainable.

2007-09-24

205

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

206

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

207

Multispectral Imaging Microscope with Millisecond Time Resolution  

E-print Network

Articles Multispectral Imaging Microscope with Millisecond Time Resolution Oleg Khait, Sergey, Wisconsin 53201 A new multispectral imaging microscope with micrometer spatial resolution and millisecond temporal resolution has been developed. The imaging microscope is based on the use of an acousto

Reid, Scott A.

208

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.

209

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

210

The Virtual Observatory: I  

NASA Astrophysics Data System (ADS)

The concept of the Virtual Observatory arose more-or-less simultaneously in the United States and Europe circa 2000. Ten pages of Astronomy and Astrophysics in the New Millennium: Panel Reports (National Academy Press, Washington, 2001), that is, the detailed recommendations of the Panel on Theory, Computation, and Data Exploration of the 2000 Decadal Survey in Astronomy, are dedicated to describing the motivation for, scientific value of, and major components required in implementing the National Virtual Observatory. European initiatives included the Astrophysical Virtual Observatory at the European Southern Observatory, the AstroGrid project in the United Kingdom, and the Euro-VO (sponsored by the European Union). Organizational/conceptual meetings were held in the US at the California Institute of Technology (Virtual Observatories of the Future, June 13-16, 2000) and at ESO Headquarters in Garching, Germany (Mining the Sky, July 31-August 4, 2000; Toward an International Virtual Observatory, June 10-14, 2002). The nascent US, UK, and European VO projects formed the International Virtual Observatory Alliance (IVOA) at the June 2002 meeting in Garching, with yours truly as the first chair. The IVOA has grown to a membership of twenty-one national projects and programs on six continents, and has developed a broad suite of data access protocols and standards that have been widely implemented. Astronomers can now discover, access, and compare data from hundreds of telescopes and facilities, hosted at hundreds of organizations worldwide, stored in thousands of databases, all with a single query.

Hanisch, R. J.

2014-11-01

211

VIRTUAL FRAME BUFFER INTERFACE  

NASA Technical Reports Server (NTRS)

Large image processing systems use multiple frame buffers with differing architectures and vendor supplied user interfaces. This variety of architectures and interfaces creates software development, maintenance, and portability problems for application programs. The Virtual Frame Buffer Interface program makes all frame buffers appear as a generic frame buffer with a specified set of characteristics, allowing programmers to write code which will run unmodified on all supported hardware. The Virtual Frame Buffer Interface converts generic commands to actual device commands. The virtual frame buffer consists of a definition of capabilities and FORTRAN subroutines that are called by application programs. The virtual frame buffer routines may be treated as subroutines, logical functions, or integer functions by the application program. Routines are included that allocate and manage hardware resources such as frame buffers, monitors, video switches, trackballs, tablets and joysticks; access image memory planes; and perform alphanumeric font or text generation. The subroutines for the various "real" frame buffers are in separate VAX/VMS shared libraries allowing modification, correction or enhancement of the virtual interface without affecting application programs. The Virtual Frame Buffer Interface program was developed in FORTRAN 77 for a DEC VAX 11/780 or a DEC VAX 11/750 under VMS 4.X. It supports ADAGE IK3000, DEANZA IP8500, Low Resolution RAMTEK 9460, and High Resolution RAMTEK 9460 Frame Buffers. It has a central memory requirement of approximately 150K. This program was developed in 1985.

Wolfe, T. L.

1994-01-01

212

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.

213

Towards Virtual Reality Games  

E-print Network

Game engines of cinematic quality, broadband networking and advances in Virtual Reality (VR) technologies are setting the stage to allow players to have shared, “better-than-life ” experiences in online virtual worlds. We propose a mechanism of merit-based selection of players, as a solution to the long-standing problem of limited access to VR hardware. 1 Games and Virtual Reality: Worlds Apart Games, including online virtual worlds, populate the entertainment arena of the consumer market. They are engaging, mass produced, inexpensive, targeting wide audiences. Visual realism in games approaches cinematic quality. The amount of 3D content available online today exceeds what can be explored in a single person’s lifetime. In contrast to gaming, VR systems require expensive hardware and customized software. They are available for limited audiences. VR systems are difficult to maintain and upgrade. Both the visual quality and the extent of virtual content are typically lower than in games. Nevertheless, VR has one feature that makes it stand out from all other platforms: the unmatched sense of presence, delivered by immersion and body tracking. The ability to make users believe that they actually “are there ” has made VR a tool of choice for medical, military, and extreme condition training applications. We discuss a concept of Virtual Reality Games that will combine the best features of games and VR: large persistent worlds experienced in photorealistic immersive settings. We suggest several solutions for bridging the gap between the two platforms.

Andrei Sherstyuk; Dale Vincent; Anton Treskunov

214

Accretion, metamorphism, and brecciation of ordinary chondrites - Evidence from petrologic studies of meteorites from Roosevelt County, New Mexico  

NASA Astrophysics Data System (ADS)

The olivines and pyroxenes from twenty-nine ordinary chondrites from Roosevelt County, New Mexico are examined. The mineralogical properties of the chondrites studied are described. Correlations between mineral compositions and petrologic type and between petrologic type and bulk chemistry are analyzed. It is observed that mean CaO concentrations in olivine show significant variations among equilibrated chondrites, but these are not correlated with petrologic type; the degree of heterogeneity of FeO concentrations in olivines of types 4-6 is not correlated with the degree of metamorphism; and mean FeO concentrations of silicates show average increases of 3-5 percent from type 4 to type 6 in each group.

Scott, Edward R. D.; Taylor, G. Jeffrey; Keil, Klaus

1986-11-01

215

Accretion, metamorphism, and brecciation of ordinary chondrites - Evidence from petrologic studies of meteorites from Roosevelt County, New Mexico  

NASA Technical Reports Server (NTRS)

The olivines and pyroxenes from twenty-nine ordinary chondrites from Roosevelt County, New Mexico are examined. The mineralogical properties of the chondrites studied are described. Correlations between mineral compositions and petrologic type and between petrologic type and bulk chemistry are analyzed. It is observed that mean CaO concentrations in olivine show significant variations among equilibrated chondrites, but these are not correlated with petrologic type; the degree of heterogeneity of FeO concentrations in olivines of types 4-6 is not correlated with the degree of metamorphism; and mean FeO concentrations of silicates show average increases of 3-5 percent from type 4 to type 6 in each group.

Scott, Edward R. D.; Taylor, G. Jeffrey; Keil, Klaus

1986-01-01

216

Reconciling mantle attenuation-temperature relationships from seismology, petrology, and laboratory measurements  

NASA Astrophysics Data System (ADS)

attenuation measurements provide a powerful tool for sampling mantle properties. Laboratory experiments provide calibrations at seismic frequencies and mantle temperatures for dry melt-free rocks, but require ˜102-103 extrapolations in grain size to mantle conditions; also, the effects of water and melt are not well understood. At the same time, body wave attenuation measured from dense broadband arrays provides reliable estimates of shear wave attenuation (QS-1), affording an opportunity for calibration. We reanalyze seismic data sets that sample arc and back-arc mantle in Central America, the Marianas, and the Lau Basin, confirming very high attenuation (QS ˜ 25-80) at 1 Hz and depths of 50-100 km. At each of these sites, independent petrological studies constrain the temperature and water content where basaltic magmas last equilibrated with the mantle, 1300-1450°C. The QS measurements correlate inversely with the petrologically inferred temperatures, as expected. However, dry attenuation models predict QS too high by a factor of 1.5-5. Modifying models to include effects of H2O and rheology-dependent grain size shows that the effects of water-enhanced dissipation and water-enhanced grain growth nearly cancel, so H2O effects are modest. Therefore, high H2O in the arc source region cannot explain the low QS, nor in the back arc where lavas show modest water content. Most likely, the high attenuation reflects the presence of melt, and some models of melt effects come close to reproducing observations. Overall, body wave QS can be reconciled with petrologic and laboratory inferences of mantle conditions if melt has a strong influence beneath arcs and back arcs.

Abers, G. A.; Fischer, K. M.; Hirth, G.; Wiens, D. A.; Plank, T.; Holtzman, B. K.; McCarthy, C.; Gazel, E.

2014-09-01

217

Single Crystal Elastic Constants From Surface-Wave Measurements on Petrologic Thin-sections  

NASA Astrophysics Data System (ADS)

Although single-crystal elastic constants for many common rock-forming minerals have been measured, significant gaps remain in mineral databases. Several authors have noted a continuing need to estimate mineral properties in order to compare seismic profiles with petrologically constrained elastic models for the crust and mantle. In part, the problem is associated with the difficulty of obtaining samples of sufficient size and quality to undertake laboratory studies. The solution suggested here makes use of samples within standard petrologic thin-sections. Individual single crystals within the section are oriented using electron backscattered diffraction (EBSD). Compositions are determined from standard microprobe analytic techniques. The Impulsive Stimulated Light Scattering method allows measurement of surface-wave velocities as a function of direction in the plane of the thin section. Velocities from several crystals of the same composition but with differing orientations relative to the thin section are inverted to determine the single crystal elastic constants tensor. An advantage of this method is the ability to work with many small and homogeneous crystals (as small as 50 microns) that can be prepared simultaneously using standard petrological techniques. The surface finish necessary for the EBSD analysis is sufficient for the acoustic measurements. Working with light back scattered from the surface removes the difficulty with previous light-transmission methods (Brillouin and ISLS) that required nearly imperfection-free crystals. Although surface waves have a strong dependence on shear elastic constants, the elliptical particle motion couples velocities to all elastic constants. Plagioclase-group minerals constitute 30% or more of the oceanic crust and a larger fraction of the continental crust. Only pseudo-single-crystal (monoclinic) properties have been reported for these triclinic minerals. We report results obtained on individual single crystals that allow investigation of the full elastic tensor. Extension of the work to high pressure is possible.

Gauvin, M.; Brown, J. M.; Abramson, E. H.; Newman, J.; Carlson, R. L.

2004-12-01

218

Petrology and 40 Ar\\/ 39 Ar isotopic ages of blueschists in Gangmar, central Qiangtang, northern Tibet  

Microsoft Academic Search

The petrology and mineral assemblages of blueschists in the Gangmar, central Qiangtang, northern Tibet were examined, which\\u000a indicates that the metamorphic condition is high-pressure low-temperature. In this note, we reported the40Ar\\/39Ar dating results of glaucophane from two blueschist samples. Their apparent ages are (275.0±1.3) Ma and (287.6±2.3) Ma and\\u000a similar isochron ages are (275.0±0.9) Ma and (282.4±0.8) Ma, respectively. These

Xiguang Deng; Lin Ding; Xiaohan Liu; Yong Zhou

2001-01-01

219

Spinel cataclasites in 15445 and 72435 - Petrology and criteria for equilibrium  

NASA Technical Reports Server (NTRS)

The problem of establishing the existence of equilibrium among the coexisting phases in the rock is addressed by presenting petrographic and mineral chemistry data on a new spinel cataclasite from 15445 (clast H) and data more extensive than those previously available on two clasts in 72435. Criteria useful in reconstructing the original petrology of these and other spinel cataclasites are analyzed by considering equilibrium among the different phases, that is, the mono- or polymict nature of these cataclasized samples. Finally, the role of impact processes in disturbing the equilibria is discussed.

Baker, M. B.; Herzberg, C. T.

1980-01-01

220

Mercury: Informing Remote Sensing through Petrology in the Absence of Samples from the Innermost Planet  

NASA Astrophysics Data System (ADS)

Remote sensing missions and petrologic studies are complementary methods of understanding airless planetary bodies. For bodies with both orbital missions and samples available for laboratory study, missions provide global chemical, mineralogical, and geologic data sets and context for samples, whereas samples often provide complementary petrogenetic histories in a chronological framework. In contrast, although the wealth of orbital data from MESSENGER is not complemented by samples from Mercury, petrologic and experimental studies remain essential to understanding the innermost planet. Prior to MESSENGER, most models centered on high-temperature events and formation under highly reducing conditions to explain Mercury's high metal to silicate ratio. These models predicted enrichment in refractory elements and depletion in volatile elements. The inference of formation at highly reducing conditions is supported by MESSENGER results. The low FeO concentration in the crust, implied low FeO contents of the mantle, apparent efficient partitioning of iron into the core, and evidence for Ca- and/or Mg-sulfides from X-Ray Spectrometer data are all consistent with reducing conditions. In contrast, the suggestion that Mercury is highly volatile-depleted has been refuted. Direct evidence for a relatively volatile-rich planet come from Na, K, and S abundances measured on the surface with MESSENGER's XRS and Gamma-Ray Spectrometer and the presence of neutral and ionized Na, K, and S species in the exosphere. Indirect evidence for volatile-rich compositions include the suggestion of volcanic vents with associated mantling pyroclastic deposits, hollows inferred to form by geologically recent volatile loss, and an inferred interior structure that includes a solid iron sulfide layer at the top of Mercury's fluid core. Petrologic and experimental studies of meteorites have played a key role in deciphering orbital data from MESSENGER. Partial melts from an enstatite chondrite assemblage produce S-rich silicate melts that subsequently crystallize Ca,Mg-sulfides and an Fe,Ni-FeS melt rich in Si, consistent with the geochemical characteristics observed or inferred from Mercury. The application of these petrologic principles, derived from the study of highly reduced meteorites, has advanced our understanding of Mercury. With new insights into the geology, mineralogy, and geochemistry of Mercury, the possibility exists that a meteorite launched from Mercury by an impact event could be identified on Earth. If such a link can be forged between a meteorite and Mercury, a new era of exploration, one largely based on isotopic systematics to understand the nature and timing of the geologic evolution of Mercury, could begin.

McCoy, T. J.; Nittler, L. R.; Stockstill-Cahill, K.; Blewett, D. T.

2012-12-01

221

Petrologically-based Electrical Profiles vs. Geophysical Observations through the Upper Mantle (Invited)  

NASA Astrophysics Data System (ADS)

Mineralogical transformations in the up-welling mantle play a critical role on the dynamics of mass and heat transfers at mid-ocean-ridgeS. The melting event producing ridge basalts occur at 60 km depth below the ridge axis, but because of small amounts of H2O and CO2 in the source region of MOR-basalts, incipient melting can initiate at much greater depth. Such incipient melts concentrate incompatible elements, and are particularly rich in volatile species. These juices evolve from carbonatites, carbonated basalts, to CO2-H2O-rich basalts as recently exposed by petrological surveys; the passage from carbonate to silicate melts is a complex pathway that is strongly non-linear. This picture has recently been complicated further by studies showing that oxygen increasingly partitions into garnet as pressure increases; this implies that incipient melting may be prevented at depth exceeding 200 km because not enough oxygen is available in the system to stabilize carbonate melts. The aim of this work is twofold: - We modelled the complex pathway of mantle melting in presence of C-O-H volatiles by adjusting the thermodynamic properties of mixing in the multi-component C-O-H-melt system. This allows us to calculate the change in melt composition vs. depth following any sortS of adiabat. - We modelled the continuous change in electrical properties from carbonatites, carbonated basalts, to CO2-H2O-rich basalts. We then successfully converted this petrological evolution along a ridge adiabat into electrical conductivity vs. depth signal. The discussion that follows is about comparison of this petrologically-based conductivity profile with the recent profiles obtained by inversion of the long-period electromagnetic signals from the East-Pacific-Rise. These geophysically-based profiles reveal the electrical conductivity structure down to 400 km depth and they show some intriguing highly conductive sections. We will discuss heterogeneity in electrical conductivity of the upper mantle underneath the ridge in terms of melting processes. Our prime conclusion is that the redox melting process, universally predicted by petrological models, might not be universal and that incipient melting can extend down to the transition zone.

Gaillard, F.; Massuyeau, M.; Sifre, D.; Tarits, P.

2013-12-01

222

The Case for a Cooperative Studio Classroom: Teaching Petrology in a Different Way  

NSDL National Science Digital Library

NOTE: This file size is large, 16.52 mb. This article describes one educator's attempts to modify his Petrology course, changing the lab-lecture format to one that emphasizes studio and cooperative learning. The goals of the changes are to improve student learning by covering a smaller number of topics in greater depth, deemphasize knowledge-based learning and emphasize development of higher order thinking skills (comprehension, application, analysis, synthesis, evaluation), and help students develop good habits of the mind and fundamental skills useful for lifelong learning. The reformatted course requires that students take more responsibility for their learning.

Perkins, Dexter

2005-01-01

223

An Entanglement-Enhanced Microscope  

E-print Network

Among the applications of optical phase measurement, the differential interference contrast microscope is widely used for the evaluation of opaque materials or biological tissues. However, the signal to noise ratio for a given light intensity is limited by the standard quantum limit (SQL), which is critical for the measurements where the probe light intensity is limited to avoid damaging the sample. The SQL can only be beaten by using {\\it N} quantum correlated particles, with an improvement factor of $\\sqrt{N}$. Here we report the first demonstration of an entanglement-enhanced microscope, which is a confocal-type differential interference contrast microscope where an entangled photon pair ({\\it N}=2) source is used for illumination. An image of a Q shape carved in relief on the glass surface is obtained with better visibility than with a classical light source. The signal to noise ratio is 1.35$\\pm$0.12 times better than that limited by the SQL.

Takafumi Ono; Ryo Okamoto; Shigeki Takeuchi

2014-01-31

224

Macroscopic-microscopic mass models  

SciTech Connect

We discuss recent developments in macroscopic-microscopic mass models, including the 1992 finite-range droplet model, the 1992 extended- Thomas-Fermi Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular emphasis on how well they extrapolate to new regions of nuclei. We also address what recent developments in macroscopic-microscopic mass models are teaching us about such physically relevant issues as the nuclear curvature energy, a new congruence energy arising from a greater-than-average overlap of neutron and proton wave functions, the nuclear incompressibility coefficient, and the coulomb redistribution energy arising from a central density depression. We conclude with a brief discussion of the recently discovered rock of metastable superheavy nuclei near {sup 272}110 that had been correctly predicted by macroscopic-microscopic models, along with a possible new tack for reaching an island near {sup 290}110 beyond our present horizon.

Nix, J.R. [Los Alamos National Lab., NM (United States); Moller, P. [Aizu Univ., Fukushima (Japan). Center for Mathematical Sciences

1995-07-01

225

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

226

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

227

Coherence-controlled holographic microscope.  

PubMed

Transmitted-light coherence-controlled holographic microscope (CCHM) based on an off-axis achromatic interferometer allows us to use light sources of arbitrary degree of temporal and spatial coherence. Besides the conventional DHM modes such as quantitative phase contrast imaging and numerical 3D holographic reconstruction it provides high quality (speckle-free) imaging, improved lateral resolution and optical sectioning by coherence gating. Optical setup parameters and their limits for a technical realization are derived and described in detail. To demonstrate the optical sectioning property of the microscope a model sample uncovered and then covered with a diffuser was observed using a low-coherence light source. PMID:20941100

Kolman, Pavel; Chmelík, Radim

2010-10-11

228

Users Manual Scanning Laser Biological Microscope  

E-print Network

Users Manual Fluoview Scanning Laser Biological Microscope Ver. 1.1 WARNING A Caution: Before using your microscope, the items in this manual Identified by the mark shown to the left should be read Microscope. Before using your microscope, read this manual thoroughly to make sure you obtain full

Kleinfeld, David

229

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

230

4-H Virtual Farm  

NSDL National Science Digital Library

With the 4-H Virtual Farm, 4-H hopes to help kids "discover why farming is part of your life even if you've never lived on a farm, never seen crops grow in a field, or never touched a cow." Even though this Web site focuses, to an extent, on Virginia agriculture, the content should be applicable and interesting to any student. Six virtual farms are available (horse, aquaculture, beef, dairy, poultry, and wheat), each offering a variety of activities and multimedia features that help students explore agricultural ecology, resource management, and much more. After visiting the 4-H Virtual Farm, students can take the Blue Ribbon Challenge, a fun interactive quiz.

231

Intraoperative virtual brain counseling  

NASA Astrophysics Data System (ADS)

Our objective is to offer online real-tim e intelligent guidance to the neurosurgeon. Different from traditional image-guidance technologies that offer intra-operative visualization of medical images or atlas images, virtual brain counseling goes one step further. It can distinguish related brain structures and provide information about them intra-operatively. Virtual brain counseling is the foundation for surgical planing optimization and on-line surgical reference. It can provide a warning system that alerts the neurosurgeon if the chosen trajectory will pass through eloquent brain areas. In order to fulfill this objective, tracking techniques are involved for intra- operativity. Most importantly, a 3D virtual brian environment, different from traditional 3D digitized atlases, is an object-oriented model of the brain that stores information about different brain structures together with their elated information. An object-oriented hierarchical hyper-voxel space (HHVS) is introduced to integrate anatomical and functional structures. Spatial queries based on position of interest, line segment of interest, and volume of interest are introduced in this paper. The virtual brain environment is integrated with existing surgical pre-planning and intra-operative tracking systems to provide information for planning optimization and on-line surgical guidance. The neurosurgeon is alerted automatically if the planned treatment affects any critical structures. Architectures such as HHVS and algorithms, such as spatial querying, normalizing, and warping are presented in the paper. A prototype has shown that the virtual brain is intuitive in its hierarchical 3D appearance. It also showed that HHVS, as the key structure for virtual brain counseling, efficiently integrates multi-scale brain structures based on their spatial relationships.This is a promising development for optimization of treatment plans and online surgical intelligent guidance.

Jiang, Zhaowei; Grosky, William I.; Zamorano, Lucia J.; Muzik, Otto; Diaz, Fernando

1997-06-01

232

HANDLING OF VIRTUAL CONTACT IN IMMERSIVE VIRTUAL ENVIRONMENTS: BEYOND VISUALS  

E-print Network

@itd.nrl.navy.mil ABSTRACT This paper addresses the issue of improving the perception of contact that users make with purely,2]. Grasping virtual controls, opening virtual doors, and using a probe to explore a volumetric data set can

Lindeman, Robert W.

233

Virtual reality welder training  

NASA Astrophysics Data System (ADS)

This document describes the Virtual Reality Simulated MIG Lab (sMIG), a system for Virtual Reality welder training. It is designed to reproduce the experience of metal inert gas (MIG) welding faithfully enough to be used as a teaching tool for beginning welding students. To make the experience as realistic as possible it employs physically accurate and tracked input devices, a real-time welding simulation, real-time sound generation and a 3D display for output. Thanks to being a fully digital system it can go beyond providing just a realistic welding experience by giving interactive and immediate feedback to the student to avoid learning wrong movements from day 1.

White, Steven A.; Reiners, Dirk; Prachyabrued, Mores; Borst, Christoph W.; Chambers, Terrence L.

2010-01-01

234

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

235

Astrophysical Virtual Observatory  

NSDL National Science Digital Library

At this website, the European Commission and six European organizations discuss the creation of the Astrophysical Virtual Observatory Project (AVO) for European astronomy. Visitors can discover the function of a Virtual Observatory (VO) as "an international astronomical community-based initiative" aimed at allowing "global electronic access to the available astronomical data archives of space and ground-based observatories." Users can learn about the current problems associated with combining astronomical data collected all over the world and how a VO can streamline this data. The website supplies numerous images illustrating galactic scenarios, AVO prototypes, and AVO goals.

236

Virtual Finance Library  

NSDL National Science Digital Library

Search Partners, a provider of executive financial search services, presents the Virtual Finance Library, a packed collection of links to financial sites. The main page of Virtual Finance Library contains general information including reference and dictionary sites, calculators and converters, and interesting links. The rest of the library is accessible via the table of contents on the left side of the screen. The Websites are organized by topic, geographic location, or subtopic. Each topic begins with a short introduction to the subject, several pages long, and most links are descriptively annotated.

237

Simulation to Virtual Reality  

E-print Network

from the visual simulation and virtual reality communities, serious games provide a delivery system for organizational video game instruction and training. During the past two decades, the virtual reality community has based its development on a synthesis of earlier work in interactive 3D graphics, user interfaces, and visual simulation. 1 Doing so let developers create a more open technology than the visual simulation community could, increased the number of people working in 3D, and developed a science, technology, and language considerably beyond that of the earlier field.

Michael Zyda; To Games; Leveraging Technology

238

The Virtual Model Repository  

NASA Astrophysics Data System (ADS)

The Virtual Model Repository is a newly funded VxO (Virtual Observatory) which plans to integrate computational model results with observed data by facilitating visualization, data/model comparisons, and independent interpretation of model results. We will give an overview of the VMR project and its progress as well as examples of its use. Specifically, we will demonstrate searching for and selecting a CCMC computation model. Then, using other VxO APIs, we will pull in relevant observed satellite data for the modeled time period and location. Finally, we will provide visualization of the relative locations of the data with some data/model comparisons.

de Zeeuw, D.; Ridley, A.; Bashkirov, V.; Maddox, M.

2008-12-01

239

Virtual interface environment workstations  

NASA Technical Reports Server (NTRS)

A head-mounted, wide-angle, stereoscopic display system controlled by operator position, voice and gesture has been developed at NASA's Ames Research Center for use as a multipurpose interface environment. This Virtual Interface Environment Workstation (VIEW) 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, management of large-scale integrated information systems, and human factors research. System configuration, research scenarios, and research directions are described.

Fisher, S. S.; Wenzel, E. M.; Coler, C.; Mcgreevy, M. W.

1988-01-01

240

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

241

The virtual tricorder: a uniform interface for virtual reality  

Microsoft Academic Search

We describe a new user-interface metaphor for immersive virtual reality — the virtual tricorder. The virtual tricor der visually duplicates a six-degrees-of-freedom input devic e in the virtual environment. Since we map the input device to the tricorder one-to-one at all times, the user identifies the two. Thus, the resulting interface is visual as well as tacti le, multipurpose, and

Matthias M. Wloka; Eliot Greenfield

1995-01-01

242

Remote laboratory for phase-aided 3D microscopic imaging and metrology  

NASA Astrophysics Data System (ADS)

In this paper, the establishment of a remote laboratory for phase-aided 3D microscopic imaging and metrology is presented. Proposed remote laboratory consists of three major components, including the network-based infrastructure for remote control and data management, the identity verification scheme for user authentication and management, and the local experimental system for phase-aided 3D microscopic imaging and metrology. The virtual network computer (VNC) is introduced to remotely control the 3D microscopic imaging system. Data storage and management are handled through the open source project eSciDoc. Considering the security of remote laboratory, the fingerprint is used for authentication with an optical joint transform correlation (JTC) system. The phase-aided fringe projection 3D microscope (FP-3DM), which can be remotely controlled, is employed to achieve the 3D imaging and metrology of micro objects.

Wang, Meng; Yin, Yongkai; Liu, Zeyi; He, Wenqi; Li, Boqun; Peng, Xiang

2014-05-01

243

Scanning tunneling microscope nanoetching method  

DOEpatents

A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

Li, Yun-Zhong (West Lafayette, IN); Reifenberger, Ronald G. (West Lafayette, IN); Andres, Ronald P. (West Lafayette, IN)

1990-01-01

244

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

245

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

246

Atomic Force Microscope (Veeco Nanoman)  

E-print Network

Atomic Force Microscope (Veeco Nanoman) User Manual ­ Basic Operation 4th Edition Aug 2012 NR #12 the operating mode. Choose TappingMode by selecting: · Tapping in Air NRF.wks · Click on Scan on the AFM head. · Adjust the Vertical Deflection to 0 V Laser spot #12;Mounting the Sample · There are two

Subramanian, Venkat

247

The Compositional Classification of Chondrules and the Petrologic Type of an Especially Primitive H Chondrite  

NASA Astrophysics Data System (ADS)

While LL chondrites of petrologic type <3.4 are relatively common, it has been only recently that a few H chondrites of type <3.4 have been reported. One of them is the heavily weathered Roosevelt County 075 [1]. Weathering and the lack of equilibration make classification uncertain, but it is probably an H chondrite. Weathering also makes it very difficult to assign a petrologic type. For example, removal of the weathering products by acid washing increased the TL sensitivity of RC075 by a factor of ~7, equivalent to a change in petrologic type estimate from 3.0 to 3.3, a major difference. The compositional classification scheme for chondrules [2,3] summarizes considerably more information than previous schemes [4-6], not least being that it tracks metamorphic effects as well as more thoroughly monitoring primary chondrule differences. It is also very easy to apply and almost 100% of the chondrules can be classified. As an example of its utility, we here show that application of the scheme to the chondrules in RC075 provides the best means of determining the petrologic type of this highly weathered, but very important, unequilibrated chondrite. The compositional classification scheme for chondrules divides them into eight classes (A1, A2, A3, A4, A5, B1, B2, B3) on the basis of the composition of the two major phases (phenocrysts and mesostasis) [2,3]. Among the changes that occur during metamorphism, olivines lose CaO and acquire uniform FeO, while the mesostases acquire oligoclase compositions having originally included compositions that were SiO2 rich (the B series), CaO rich (the A series), and Na2O rich (A5). These changes give rise to CL properties that can be used as an alternative to microprobe analysis and which, like microprobe data, are insensitive to weathering. Thus we were able to assign all of the almost 100 chondrules present in a 7 x 5-mm section of RC075 to compositional classes. The results are shown in Fig. 1, along with similar data from [3]. The relative abundance and classes of chondrules present provides an excellent method of assigning petrographic type. The relative abundance of group B chondrules in RC075 is less than Semarkona (3.0), and comparable with the higher types, while the abundance of A5 chondrules is comparable to that in Krymka (3.1) and intermediate between that in Semarkona and Chainpur (3.4). Most significantly, the fraction of A1 chondrules is very large and comparable (within error) to that of Semarkona, while the large number of group A3 chondrules is comparable only to Krymka. Apparently, RC075 is intermediate to Semarkona and Chainpur and comparable to Krymka in its petrologic type. McCoy et al. [1] report means ranging from 0.07 to 7.2 mol% Fa and 0.11 to 0.36 wt% CaO for olivine in six type-IA chondrules and 12.3-20.2 mol% Fa for five type-II chondrules in RC075 [1]. Four of the type IA chondrules resembled those of Semarkona in olivine composition (<2 mol% Fa). Unlike the compositional classification scheme, which leads fairly simply to unambiguous petrologic type assignment, it seems difficult to assign RC075 to a petrologic type on the basis of olivine compositions and texture alone. Other advantages of the new scheme are (1) that it applies to individual chondrules and makes no assumptions about average response of chondrules to metamorphism; (2) it is insensitive to brecciation, which is common in UOC [7]; and (3) it is quantitative, and does not require subjective evaluations of texture, although textural descriptions may be used with the compositional class (just as they are for chondrites). The compositional classification scheme is certainly subject to improvement(e.g. class A5, both in type 3 and higher types). However, as it currently stands the scheme clearly provides the best way of not only describing individual chondrules, but of assessing primary chondrule properties and the extent of changes experienced during metamorphism. Thus it provides the best method for assigning the weathered and highly unequilibrated RC075 meteorite to a petrologic ty

Sears, D. W. G.; Huang, S.; Benoit, P. H.

1993-07-01

248

Petrological and seismic precursors of the paroxysmal phase of the last Vesuvius eruption on March 1944  

NASA Astrophysics Data System (ADS)

Abrupt transitions in style and intensity are common during volcanic eruptions, with an immediate impact on the surrounding territory and its population. Defining the factors trigger such sudden shifts in the eruptive behavior as well as developing methods to predict such changes during volcanic crises are crucial goals in volcanology. In our research, the combined investigation of both petrological and seismic indicators has been applied for the first time to a Vesuvius eruption, that of March 1944 that caused the present dormant state of the volcano. Our results contribute to elucidate the evolution of the conduit dynamics that generated a drastic increase in the Volcanic Explosivity Index, associated to the ejection of huge amount of volcanic ash. Remarkably, our study shows that the main paroxysm was announced by robust changes in petrology consistent with seismology, thus suggesting that the development of monitoring methods to assess the nature of ejected juvenile material combined with conventional geophysical techniques can represent a powerful tool for forecasting the evolution of an eruption towards violent behavior. This in turn is a major goal in volcanology because this evidence can help decision-makers to implement an efficient safety strategy during the emergency (scale and pace of evacuation).

Pappalardo, Lucia; D'Auria, Luca; Cavallo, Andrea; Fiore, Stefano

2014-09-01

249

Petrology and Geochemistry of Unbrecciated Harzburgitic Diogenite MIL 07001: A Window Into Vestan Geological Evolution  

NASA Technical Reports Server (NTRS)

There is a strong case that asteroid 4 Vesta is the parent of the howardite, eucrite and diogenite (HED) meteorites. Models developed for the geological evolution of Vesta can satisfy the compositions of basaltic eucrites that dominate in the upper crust. The bulk compositional characteristics of diogenites - cumulate harzburgites and orthopyroxenites from the lower crust - do not fit into global magma ocean models that can describe the compositions of basaltic and cumulate eucrites. Recent more detailed formation models do make provision for a more complicated origin for diogenites, but this model has yet to be completely vetted. Compositional studies of bulk samples has led to the hypothesis that many diogenites were formed late by interaction of their parent melts with a eucritic crust, but those observations may alternatively be explained by subsolidus equilibration of trace elements between orthopyroxene and plagioclase and Ca-phosphate in the rocks. Differences in radiogenic Mg-26 content between diogenites and eucrites favors early formation of the former, not later formation. Understanding the origin of diogenites is crucial for understanding the petrologic evolution of Vesta. We have been doing coordinated studies of a suite of diogenites including petrologic investigations, bulk rock major and trace element studies, and in situ trace element analyses of orthopyroxene. Here we will focus on an especially unusual, and potentially key, diogenite, MIL 07001.

Mittlefehldt, D. W.; Peng, Z. X.; Mertzman, S. A.; Mertzman, K. R.

2014-01-01

250

Petrological and seismic precursors of the paroxysmal phase of the last Vesuvius eruption on March 1944.  

PubMed

Abrupt transitions in style and intensity are common during volcanic eruptions, with an immediate impact on the surrounding territory and its population. Defining the factors trigger such sudden shifts in the eruptive behavior as well as developing methods to predict such changes during volcanic crises are crucial goals in volcanology. In our research, the combined investigation of both petrological and seismic indicators has been applied for the first time to a Vesuvius eruption, that of March 1944 that caused the present dormant state of the volcano. Our results contribute to elucidate the evolution of the conduit dynamics that generated a drastic increase in the Volcanic Explosivity Index, associated to the ejection of huge amount of volcanic ash. Remarkably, our study shows that the main paroxysm was announced by robust changes in petrology consistent with seismology, thus suggesting that the development of monitoring methods to assess the nature of ejected juvenile material combined with conventional geophysical techniques can represent a powerful tool for forecasting the evolution of an eruption towards violent behavior. This in turn is a major goal in volcanology because this evidence can help decision-makers to implement an efficient safety strategy during the emergency (scale and pace of evacuation). PMID:25199537

Pappalardo, Lucia; D'Auria, Luca; Cavallo, Andrea; Fiore, Stefano

2014-01-01

251

Interactive computer programs for petrologic modeling with extended Q-mode factor analysis  

USGS Publications Warehouse

An extended form of Q-mode factor analysis may be used if the row-sums of the data matrix are constant and can be helpful especially in developing and testing petrologic-mixing models for igneous systems. The first step is to represent the sample compositions as unit vectors in M-dimensional space and then to project them into space of fewer dimensions (m) as determined to be appropriate from a factor-variance diagram. Compositions thought to be those of possible end-members in the petrologic system then are represented as vectors in the M-dimensional space and projected into the same space as the sample vectors. If these vectors remain close to unity in length after projection, the corresponding compositions can serve as end-member compositions for the model. After m suitable end-member compositions have been identified, each sample composition is expressed as a mixture of the end-members by computation of the composition loadings. The interactive computer programs presented are useful in these procedures because of the trial-and-error nature of the modeling procedures. ?? 1976.

Miesch, A.T.

1976-01-01

252

Petrological and seismic precursors of the paroxysmal phase of the last Vesuvius eruption on March 1944  

PubMed Central

Abrupt transitions in style and intensity are common during volcanic eruptions, with an immediate impact on the surrounding territory and its population. Defining the factors trigger such sudden shifts in the eruptive behavior as well as developing methods to predict such changes during volcanic crises are crucial goals in volcanology. In our research, the combined investigation of both petrological and seismic indicators has been applied for the first time to a Vesuvius eruption, that of March 1944 that caused the present dormant state of the volcano. Our results contribute to elucidate the evolution of the conduit dynamics that generated a drastic increase in the Volcanic Explosivity Index, associated to the ejection of huge amount of volcanic ash. Remarkably, our study shows that the main paroxysm was announced by robust changes in petrology consistent with seismology, thus suggesting that the development of monitoring methods to assess the nature of ejected juvenile material combined with conventional geophysical techniques can represent a powerful tool for forecasting the evolution of an eruption towards violent behavior. This in turn is a major goal in volcanology because this evidence can help decision-makers to implement an efficient safety strategy during the emergency (scale and pace of evacuation). PMID:25199537

Pappalardo, Lucia; D'Auria, Luca; Cavallo, Andrea; Fiore, Stefano

2014-01-01

253

Interactively Directing Virtual Crowds in a Virtual Environment  

Microsoft Academic Search

Simulation of emergent group behaviors for creatures such as birds and fishes has been widely used in computer animation. Although the same technique can be adopted to simulate crowds of virtual humans in a shared virtual world, it remains a great challenge to simulate the high-level intelligent behavior of a virtual human with planning capabilities. In this paper, we present

Tsai-Yen Li; Jian-Wen Lin; Yi-Lin Liu; Chang-Ming Hsu

2000-01-01

254

Applying Artificial Intelligence to Virtual Reality: Intelligent Virtual Environments  

E-print Network

Applying Artificial Intelligence to Virtual Reality: Intelligent Virtual Environments Ruth Aylett intelligence and artificial life on the other has largely been carried out by two different groups of people combining artificial intelligence and artificial life techniques with those of virtual environments

Luck, Michael

255

Virtual reality for emergency training  

SciTech Connect

Virtual reality is a sequence of scenes generated by a computer as a response to the five different senses. These senses are sight, sound, taste, touch, smell. Other senses that can be used in virtual reality include balance, pheromonal, and immunological senses. Many application areas include: leisure and entertainment, medicine, architecture, engineering, manufacturing, and training. Virtual reality is especially important when it is used for emergency training and management of natural disasters including earthquakes, floods, tornados and other situations which are hard to emulate. Classical training methods for these extraordinary environments lack the realistic surroundings that virtual reality can provide. In order for virtual reality to be a successful training tool the design needs to include certain aspects; such as how real virtual reality should be and how much fixed cost is entailed in setting up the virtual reality trainer. There are also pricing questions regarding the price per training session on virtual reality trainer, and the appropriate training time length(s).

Altinkemer, K. [Purdue Univ., West Lafayette, IN (United States). Krannert Graduate School of Management

1995-12-31

256

Algorithmic architecture in virtual spaces  

E-print Network

Much of the recent interest in virtual worlds has focused on using the immersive properties of virtual worlds to recreate an experience like that of interacting face to face with other participants. This thesis instead ...

Harry, Drew

2008-01-01

257

Age Determination and Chemical and Petrological Features of Shock-Melted Antarctic H Chondrite Y 790746: Preliminary Results  

NASA Astrophysics Data System (ADS)

Extensive K-Ar age determinations have been carried out for shocked chondrites [1]. However the young shock ages obtained by the less susceptible clocks such as Rb-Sr isotopes are still rarely reported for chondritic meteorites [2,3], particulary only for H-chondrites [4]. In order to search for ages, chemical and petrological characteristics of shocked H-chondrites, we have carried out analyses of Rb-Sr, K-Ar and other rare gass isotopes along with isotope dilution analyses of K, Rb, Sr, Ba, Ca, Mg, and Fe for impact melted Antarctic H-chondreite, Y-790746. The meteorite contains shock veins (widths: 5-10mm) formed from melts. One intensely melted portion was sampled for the present study. The observations by an optical microscope and a scanning electron microscope indicate that the specimen has basaltic texture consisting of relic olivine grains with several hundred micrometer sizes, cryptocrystalline subhedral olivines and pyroxenes associated with glassy groundmass. Relic olivines with undulatory extinction and planar fractures occasionally carry several micrometer sized Fe-Ni deposits and shock veins. Recrystallized olivines and pyroxenes are mostly zoned by Fe-rich overgrowth rims. Ca-rich pyroxenes also carry Ca depleted overgrowth rim materials. Numerous Fe-Ni metal droplets (several ten to hundred micrometer sizes) associated with troilites also exist in interstitial areas of mineral grains. No plagioclase nor maskerynite grains were identified but instead abundant glassy materials exist in the interstitial areas. Abundances of alkali metals (K, Rb) and alkaline earths (Ba, Sr) in the whole-rock are almost H-chondritic (x1.02, x1.41, x1.19, x1.1; relative to average H-chondrites). The major element abundances normalized to average H-chondrites are low in Mg (x0.84), Fe (x0.70), and Ca (x0.87), indicating that Y-790746 is depleted in mafic components. These results suggest that Fe-Ni metal, (possibly, olivines and pyroxenes) was removed from the source during impact-melting event on the parent body. For the purpose of internal Rb-Sr isochron age determination, bulk sample was crushed, seived and subjected to mineral separation with a Franz isodynamic separator and 6 mineral separate fractions (coarse grain, medium grain, fine grain, further mineral separates) were obtained. Three specimens were analyzed for rare gasses, and all fractions were analyzed for Rb-Sr isotopes. The K-Ar age of 2.66 +/- 0.20 Ga was obtained for the whole rock. This age is substantially in agreement with those of two mineral separates. The results of Rb-Sr analyses indicate that the largest spread of the horizontal axis (^87Rb/^86Sr ratio) is only about 10%, so the precise age was not obtained. Data point of whole-rock is plotted on the left side of the 4.55 Ga ALL reference isochron [5]. On the other hand, data points of most mineral separates are plotted on the right side of the referene line. The tie line between whole rock and mineral separates corresponds to 288 +/- 190 Ma which have no age meaning. Therfore, the Rb-Sr system was perturbed by a late event. Further detailed Rb-Sr isotopic analyses are now in progress. From the chemical and petrological features, it is suggested that a large scale impact melting event underwent on the H-chondrite parent body at significant later time and Y-790746 may have been derived from a melt-sheet of an impact crater. References: [1] Bogard D. D. (1995) Meteoritics, 30, 244-268. [2] Nakamura N. and Okano O. (1985) Nature, 315, 563-566. [3] Nakamura N. et al. (1990) Nature, 345, 51-52. [4] Fujimaki H. et al. (1994) Proc. NIPR Symp. Antarct. Meteorites, 7, 387-388. [5] Gray C. M. et al. (1973) Icarus, 20, 213-239.

Nakashima, T.; Nagao, K.; Nakamura, N.; Fujiwara, T.; Misawa, K.; Kagami, H.; Yanai, K.; Kojima, H.

1995-09-01

258

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

259

The Virtual Classroom.  

ERIC Educational Resources Information Center

Increasingly, college teachers and instructional designers are exploring use of the technology of virtual reality to enhance student learning in math, science, and the social sciences. It is found particularly useful for teaching psychomotor skills and may have potential to make scientific concepts and abstract subjects more accessible to…

Roach, Ronald

1997-01-01

260

Virtual Rehabilitation after Stroke  

Microsoft Academic Search

The purpose of this project was to investigate the effects of Virtual Reality technology and haptics for stroke rehabilitation. Twenty-nine stroke subjects, 17 women, and 12 men aged 44-85 years, participated in three different studies. All participants responded favorable to the use of the VR activity station. A change of attitude took place after the subjects were exposed to playing

Jurgen Broeren; Ann Bjorkdahl; Lisbeth Claesson; Daniel Goude; Åsa Lundgren-nilsson; Hans Samuelsson; Christian Blomstrand; Katharina Stibrant Sunnerhagen; Martin Rydmark

2008-01-01

261

Motion Graphs Virtual Lab  

NSDL National Science Digital Library

The Motion Graphs virtual lab helps physics students learn the essential features of position vs. time and velocity vs. time graphs. Students are provided sample graphs, and they try to move the on-screen caterpillar in order to make the caterpillar's motion match the sample graph. A printable activity guide is included.

2014-04-03

262

Literacy in Virtual Worlds  

ERIC Educational Resources Information Center

Introducing new digital literacies into classroom settings is an important and challenging task, and one that is encouraged by both policy-makers and educators. This paper draws on a case study of a 3D virtual world which aimed to engage and motivate primary school children in an immersive and literacy-rich on-line experience. Planning decisions,…

Merchant, Guy

2009-01-01

263

Virtual Inquiry Experiences  

ERIC Educational Resources Information Center

Children in classrooms and scientists in laboratories engage in similar activities: they observe, ask questions, and try to explain phenomena. Video conferencing technology can remove the wall between the classroom and the laboratory, bringing children and scientists together. Virtual experiences and field trips can provide many of the benefits of…

Harlow, Danielle; Nilsen, Katy

2011-01-01

264

Towards Successful Virtual Communities  

Microsoft Academic Search

With the multiplication of communication medium, the increasing multi-partner global organizations, the remote working tendencies, dynamic teams, pervasive or ubiquitous computing Virtual Communities (VCs) are playing an increasing role in social organizations currently and will probably change pro- foundly the way people interact in the future. In this paper, we present our posi- tion on the key characteristics that are

Julien Subercaze; Christo El-morr; Pierre Maret; Adrien Joly; Matti Koivisto; Panayotis Antoniadis; Masayuki Ihara

2009-01-01

265

Virtual Field Trips.  

ERIC Educational Resources Information Center

Virtual field trips can provide experiences beyond the reach of average K-12 students. Describes multimedia products for school use: Africa Trail, Dinosaur Hunter, Louvre Museum, Magic School Bus Explores the Rainforest, and Up to the Himalayas: Kingdoms in the Clouds and provides book and Internet connections for additional learning, highlighting…

Walter, Virginia A.

1997-01-01

266

More Virtual Field Trips.  

ERIC Educational Resources Information Center

This directory covers additional Web sites and opportunities that have appeared in the year since the original book, "Virtual Field Trips," was published. The field trips provided are appropriate for K-12 students and designed to meet the goals and interests of educators. Organized by subjects and cross-referenced for quick and easy access, these…

Cooper, Gail; Cooper, Gary

267

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

268

Fish tank virtual reality  

Microsoft Academic Search

The defining characteristics of what we call “Fish Tank Virtual Reality” are a stereo image of a three dimensional (3D) scene viewed on a monitor using a perspective projection coupled to the head position of the observer. We discuss some of the relative merits of this mode of viewing as compared to head mounted stereo displays. In addition, we report

Colin Ware; Kevin Arthur; Kellogg S. Booth

1993-01-01

269

Optimizing Embedded Virtual Machines  

Microsoft Academic Search

Virtual machines (VMs) play an important role in mainstream computing by enabling interoperability, security, and higher levels of abstraction. Their use in embedded computing systems is deterred primarily by the resource constraints of embedded microcontrollers. In this paper, we show how various optimizations can significantly decrease these overheads, making VMs viable as system software for even low-end (8- or 16-bit)

Joel Koshy; Raju Pandey; Ingwar Wirjawan

2009-01-01

270

Virtual Roller Coaster  

Microsoft Academic Search

Roller coasters are an attractive, adventurous and exciting form of entertainment. In this paper, we present a virtual roller coaster system, which includes roller coaster simulation software, a motion platform and a motion control unit. We investigate the track structure of the roller coaster and propose a methodology to generate the track automatically. We also simulate the forces exerted on

Zen-chung Shih; Yuh-sen Jaw; Mei-ling Hsu

2000-01-01

271

IP Virtual Private Networks  

Microsoft Academic Search

Existing technologies, including frame relay and ATM, can be used to create virtual private networks (VPNs) over a shared infrastructure. However, two new technologies, tag switching and IP security, may be used to create IP VPNs that are independent of the access network and the core technology. This paper examines these technologies, compares them to each other and to existing

S Hills; D McGlaughlin; N Hanafi

2000-01-01

272

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

273

Virtual Coin Toss  

NSDL National Science Digital Library

Have you ever wondered what would happen if you tossed a coin one hundred times? What about 1,000? What about 10,000? Would you end up with more heads or more tails? Cyberspace has made it easy for you to find out using their virtual coin toss machine. This site is very helpful when studying probability!

2008-01-01

274

War Games Go Virtual  

ERIC Educational Resources Information Center

This article describes how researchers work with military to create the next generation of training technology. This article also describes the features of Flatworld, a virtual military training technology. Flatworld is one of many projects under development at the Institute for Creative Technologies, a research group that is supported primarily…

Carlson, Scott

2006-01-01

275

Definition of Virtual Levels.  

ERIC Educational Resources Information Center

Presents an examination of graphical displays of solutions to time-dependent Schrodinger equation modeling a laser-excited three-level atom. It suggests that an energy level may be regarded as virtual when it is detuned from resonance by more than two Rabi frequencies. (Author/HM)

Shore, Bruce W.

1979-01-01

276

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

277

Virtual physics circus  

Microsoft Academic Search

This video shows the Virtual Physics Circus, a kind of playground for experimenting with simple physical models. The system makes it easy to create worlds with common physical objects such as swings, vehicles, ramps, and walls, and interactively play with those worlds. The system can be used as a creative art medium as well as to gain understanding and intuition

Don Kimber; Eleanor G. Rieffel; Jim Vaughan; John Doherty

2008-01-01

278

Virtual Reality Hysteroscopy  

PubMed

New interactive computer technologies are having a significant influence on medical education, training, and practice. The newest innovation in computer technology, virtual reality, allows an individual to be immersed in a dynamic computer-generated, three-dimensional environment and can provide realistic simulations of surgical procedures. A new virtual reality hysteroscope passes through a sensing device that synchronizes movements with a three-dimensional model of a uterus. Force feedback is incorporated into this model, so the user actually experiences the collision of an instrument against the uterine wall or the sensation of the resistance or drag of a resectoscope as it cuts through a myoma in a virtual environment. A variety of intrauterine pathologies and procedures are simulated, including hyperplasia, cancer, resection of a uterine septum, polyp, or myoma, and endometrial ablation. This technology will be incorporated into comprehensive training programs that will objectively assess hand-eye coordination and procedural skills. It is possible that by incorporating virtual reality into hysteroscopic training programs, a decrease in the learning curve and the number of complications presently associated with the procedures may be realized. Prospective studies are required to assess these potential benefits. PMID:9074164

Levy

1996-08-01

279

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

280

Using the Virtual Design Center  

Microsoft Academic Search

The Virtual Design Center (http:\\/\\/vdc.cet.edu) provides research-based design guidelines for inquiry-based learning activities. The Virtual Design Center also provides educational researchers opportunities to share new knowledge about how practitioners could apply learning theories to learning activities. The participants will be introduced to the six-step process and the various services of the Virtual Design Center. The Virtual Design Center's process has

Beaumie Kim

2006-01-01

281

Petrology, 39Ar-40Ar and Exposure Ages, and Chemistry of a Gabbro Area from the Caddo Co. IAB Iron  

NASA Astrophysics Data System (ADS)

Petrological, chemical and 39Ar-40Ar age studies of silicate from the Caddo County IAB iron reveals a gabbroic area of feldspar and high-Ca pyroxene, enriched in incompatible lithophile elements, and last degassed of 40Ar 4.52-4.54 Gyr ago.

Bogard, D.; Takeda, H.; Mittlefehldt, D. W.; Garrison, D.

1999-03-01

282

Amino acid composition, petrology, geochemistry, 14C terrestrial age and oxygen isotopes of the Shisr 033 CR chondrite  

Microsoft Academic Search

We have analyzed Shisr 033, a CR chondrite from the Omani desert, using several different analytical techniques designed to study the degree of terrestrial alteration of this meteorite and also its petrologic classification. Bulk chemical analyses (including organic carbon and mean total H2O content) are consistent with a CR classification. Additionally, oxygen isotope analysis on a bulk sample indicates that

Z. Martins; B. A. Hofmann; E. Gnos; R. C. Greenwood; A. Verchovsky; I. A. Franchi; A. J. T. Jull; O. Botta; D. P. Glavin; J. P. Dworkin; P. Ehrenfreund

2007-01-01

283

Crystal chemistry, and thermodynamic and kinetic properties of calcite, dolomite, apatite, and biogenic silica: applications to petrologic problems  

Microsoft Academic Search

Sedimentary minerals are generally metastable phases that, given time and changing environmental conditions, recrystallize to more stable phases. The actual pathway of stabilization is governed by a host of kinetic factors. Unfortunately, much of the theoretical and experimental work on thermodynamic and kinetic behavior of sedimentary minerals either has not reached field practitioners in sedimentary petrology, or has been conducted

Jane S. Tribble; Rolf S. Arvidson; Fred T. Mackenzie

1995-01-01

284

The Mount Manengouba, a complex volcano of the Cameroon Line:1 Volcanic history, petrological and geochemical features2  

E-print Network

1 The Mount Manengouba, a complex volcano of the Cameroon Line:1 Volcanic history, petrological 24 Keywords: Cameroon Volcanic Line, Manengouba volcano, alkaline magmatism, Quaternary25 volcanism is related to four chronological stages: 1) forming31 of the early Manengouba shield volcano between 1

Boyer, Edmond

285

Detrital thermochronology and sediment petrology of the middle Siwaliks along the Muksar Khola section in eastern Nepal  

E-print Network

section in eastern Nepal François Chirouze a , Matthias Bernet a, , Pascale Huyghe a , Véronique Erens b Formation in eastern Nepal along the Muksar Khola section for thermochronologic and sediment petrologic Formation of eastern Nepal has some similarities but also differences with published data for western

Utrecht, Universiteit

286

Thermal modeling of the southern Alaska subduction zone: Insight into the petrology of the subducting slab and overlying mantle wedge  

SciTech Connect

This report discusses a two-dimensional thermal model of the southern Alaska subduction zone. This model allows specfic predictions to be made about the pressure-temperature conditions and mineralogy of the subducting oceanic crust and the mantle wedge and assess different petrologic models for the generation of Alaskan arc magmas.

Ponko, S.C.; Peacock, S.M. [Arizona State Univ., Tempe, AZ (United States)] [Arizona State Univ., Tempe, AZ (United States)

1995-11-10

287

Exhumation tectonics of the ultrahigh-pressure metamorphic rocks in the Qinling orogen in east China: New petrological-structural-  

E-print Network

Block (SCB), we argue that all three areas are parts of the SCB. Structural, petrologic, 40 Ar/39 Ar Block (SCB) [e.g., Mattauer et al., 1985, 1991; Okay et al., 1993]. The Dabieshan massif that forms accepted that the boundary between NCB and SCB lies in the central part of the Shandong peninsula

Paris-Sud XI, Université de

288

Final report of special geological, geochemical, and petrological studies of the Devonian shales in the Appalachian Basin  

Microsoft Academic Search

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 Overthrust, Brallier Formation, and Ohio Shale along Lake Erie. discussion is presented under the main headings: Chemical Characterization;composition, Fabric, Texture, Bedding, and

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

1980-01-01

289

Technology Counts 2012: Virtual Shift  

ERIC Educational Resources Information Center

Virtual education is moving into that intersection where rising popularity meets calls for greater accountability. How the virtual education movement responds to those calls will have a significant impact on how it evolves in K-12 over the next five to 10 years. This report tackles this shift in the virtual education landscape. It examines the…

Education Week, 2012

2012-01-01

290

Virtual Reality in the Classroom.  

ERIC Educational Resources Information Center

Considers the concept of virtual reality; reviews its history; describes general uses of virtual reality, including entertainment, medicine, and design applications; discusses classroom uses of virtual reality, including a software program called Virtus WalkThrough for use with a computer monitor; and suggests future possibilities. (34 references)…

Pantelidis, Veronica S.

1993-01-01

291

Virtual interaction in cognitive neuropsychology  

Microsoft Academic Search

Several recent studies have investigated whether knowledge representation turns possible within virtual reality simulated environments. According to these affirmative results different clinical applications were developed in psychology. Among these applications virtual reality seems to have a specific role in assessment and treatment of neuropsychological diseases. This chapter will firstly investigate possibilities and challenges carried from virtual-reality-based neuropsychological application focusing both

Francesca MORGANTI

292

Ethnography in a Virtual World  

ERIC Educational Resources Information Center

This article situates the discussion of virtual ethnography within the larger political/economic changes of twenty-first century consumer capitalism and suggests that increasingly our entire social world is a virtual world and that there were very particular utopian and dystopian framings of virtual community growing out of that history. The…

Shumar, Wesley; Madison, Nora

2013-01-01

293

The Virtual Desktop User's Guide  

E-print Network

The Virtual Desktop User's Guide Version 1.0 · 18 April, 2000 #12;Table of contents 1. Registration.......................................................................................................... 16 The Virtual Desktop · User's Guide Page 1 #12;1. Registration If you are a new user, this is your at the Virtual Desktop system for the first time, you will be presented with the screen in Figure 1 (the main

Riabov, Vladimir V.

294

Virtual strings and their cobordisms  

Microsoft Academic Search

A virtual string is a scheme of self-intersections of a closed curve on a surface. We study algebraic invariants of strings as well as two equivalence relations on the set of strings: homotopy and cobordism. We show that the homotopy invariants of strings form an infinite dimensional Lie group. We also discuss connections between virtual strings and virtual knots.

Vladimir Turaev

2003-01-01

295

Virtual organization and electronic commerce  

Microsoft Academic Search

The purpose of this article is to contribute to understanding the virtual organization and its relationship with electronic commerce. The relevant literature on virtual organization forms through which business-to-business e-commerce is organized is reviewed. A model of the virtual organization is presented and its use in a case study demonstrated. Implications for further research are discussed.

Bob Travica

2005-01-01

296

Virtual Construction of Social Reality  

Microsoft Academic Search

This is a study on the creation of social reality in virtual setting such as chat\\/discussion\\/list groups, based on a theoretical framework of social and cultural reality. It was tried to be found how closer one can get to and create the reality in relation with others in virtual settings. It is a survey type study. For this, a virtually

Sahin KARASAR

297

A Virtual Assembly Design Environment  

Microsoft Academic Search

The Virtual Assembly Design Environment (VADE) is a Virtual Reality (VR)-based engineering application that allows engineers to evaluate, analyze, and plan the assembly of mechanical systems. This system focuses on utilizing an immersive, virtual environment tightly coupled with commercial computer aided design (CAD) systems. Salient features of VADE include: 1) data integration (two-way) with a parametric CAD system, 2) realistic

Sankar Jayaram; Yong Wang; Uma Jayaram; Kevin W. Lyons; Peter Hart

1999-01-01

298

How to Create a Virtual Life ?  

Microsoft Academic Search

Virtual Life is a new area dedicated to the simulation of life in virtual worlds, human-virtual interaction and immersion inside virtual worlds. Virtual Life cannot exist without the growing development of Computer Animation techniques and corresponds to the most advanced concepts and techniques of it. In this chapter, we present current research developments in the Virtual Life of autonomous synthetic

Daniel Thalmann; Hansrudi Noser; Zhiyong Huang

299

Designing and embedding reliable virtual infrastructures  

Microsoft Academic Search

In a virtualized infrastructure where physical resources are shared, a single physical server failure will terminate several virtual servers and crippling the virtual infrastructures which contained those virtual servers. In the worst case, more failures may cascade from overloading the remaining servers. To guarantee some level of reliability, each virtual infrastructure, at instantiation, should be augmented with backup virtual nodes

Wai-Leong Yeow; Cedric Westphal; Ulas C. Kozat

2011-01-01

300

Nanocarpets for Trapping Microscopic Particles  

NASA Technical Reports Server (NTRS)

Nanocarpets that is, carpets of carbon nanotubes are undergoing development as means of trapping microscopic particles for scientific analysis. Examples of such particles include inorganic particles, pollen, bacteria, and spores. Nanocarpets can be characterized as scaled-down versions of ordinary macroscopic floor carpets, which trap dust and other particulate matter, albeit not purposefully. Nanocarpets can also be characterized as mimicking both the structure and the particle-trapping behavior of ciliated lung epithelia, the carbon nanotubes being analogous to cilia. Carbon nanotubes can easily be chemically functionalized for selective trapping of specific particles of interest. One could, alternatively, use such other three-dimensionally-structured materials as aerogels and activated carbon for the purposeful trapping of microscopic particles. However, nanocarpets offer important advantages over these alternative materials: (1) Nanocarpets are amenable to nonintrusive probing by optical means; and (2) Nanocarpets offer greater surface-to-volume ratios.

Noca, Flavio; Chen, Fei; Hunt, Brian; Bronikowski, Michael; Hoenk, Michael; Kowalczyk, Robert; Choi, Daniel

2004-01-01

301

Hyperbaric Hydrothermal Atomic Force Microscope  

DOEpatents

A hyperbaric hydrothermal atomic force microscope (AFM) is provided to image solid surfaces in fluids, either liquid or gas, at pressures greater than normal atmospheric pressure. The sample can be heated and its surface imaged in aqueous solution at temperatures greater than 100.degree. C. with less than 1 nm vertical resolution. A gas pressurized microscope base chamber houses the stepper motor and piezoelectric scanner. A chemically inert, flexible membrane separates this base chamber from the sample cell environment and constrains a high temperature, pressurized liquid or gas in the sample cell while allowing movement of the scanner. The sample cell is designed for continuous flow of liquid or gas through the sample environment.

Knauss, Kevin G. (Livermore, CA); Boro, Carl O. (Milpitas, CA); Higgins, Steven R. (Laramie, WY); Eggleston, Carrick M. (Laramie, WY)

2003-07-01

302

Hyperbaric hydrothermal atomic force microscope  

DOEpatents

A hyperbaric hydrothermal atomic force microscope (AFM) is provided to image solid surfaces in fluids, either liquid or gas, at pressures greater than normal atmospheric pressure. The sample can be heated and its surface imaged in aqueous solution at temperatures greater than 100.degree. C. with less than 1 nm vertical resolution. A gas pressurized microscope base chamber houses the stepper motor and piezoelectric scanner. A chemically inert, flexible membrane separates this base chamber from the sample cell environment and constrains a high temperature, pressurized liquid or gas in the sample cell while allowing movement of the scanner. The sample cell is designed for continuous flow of liquid or gas through the sample environment.

Knauss, Kevin G. (Livermore, CA); Boro, Carl O. (Milpitas, CA); Higgins, Steven R. (Laramie, WY); Eggleston, Carrick M. (Laramie, WY)

2002-01-01

303

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

304

Duties to Extraterrestrial Microscopic Organisms  

NASA Astrophysics Data System (ADS)

Formulating a normative axiology for the treatment of extraterrestrial microscopic organisms, should they ever be found, requires an extension of environmental ethics to beyond the Earth. Using an ethical framework for the treatment of terrestrial micro-organisms, this paper elaborates a similar ethic for the treatment of extraterrestrial microscopic organisms. An ethic of `teloempathy' allows for the moral considerability of any organism that has `interests', based on rudimentary qualities of conativism, and therefore allows for an identical treatment of all life, related or not related to life on Earth. Although, according to this ethic, individual extraterrestrial microscopic organisms have a good of their own and even `rights', at this level the ethic can only be theoretical, allowing for the inevitable destruction of many individual organisms during the course of human exploratory missions, similarly to the daily destruction of microbes by humans on Earth. A holistic teloempathy, an operative ethic, not only provides a framework for human exploration, but it also has important implications for planetary protection and proposals to implement planetary-scale atmospheric alterations on other bodies. Even prior to the discovery of extraterrestrial life, or the discovery of a complete absence of such life, this exercise yields important insights into the moral philosophy that guides our treatment of terrestrial micro-organisms.

Cockell, C. S.

305

Gelation on the microscopic scale  

NASA Astrophysics Data System (ADS)

Particle-tracking methods are used to study gelation in a colloidal suspension of Laponite clay particles. We track the motion of small fluorescent polystyrene spheres added to the suspension, and obtain the micron-scale viscous and elastic moduli of the material from their mean-squared displacement. The fluorescent spheres move subdiffusively due to the microstructure of the suspension, with the diffusive exponent decreasing from close to one at early times to near zero as the material gels. The particle-tracking data show that the system becomes more heterogeneous on the microscopic scale as gelation proceeds. We also determine the bulk-scale moduli using small-amplitude oscillatory shear rheometry. Both the macroscopic and microscopic moduli increase with time, and on both scales we observe a transition from a primarily viscous fluid to an elastic gel. We find that the gel point, determined as the time at which the viscous and elastic moduli are equal, is length-scale dependent—gelation occurs earlier on the bulk scale than on the microscopic scale.

Oppong, Felix K.; Coussot, P.; de Bruyn, John R.

2008-08-01

306

Fluid inclusion and petrological studies provide insight to the reconstruction of magma conduit systems  

NASA Astrophysics Data System (ADS)

Combined petrological and fluid inclusion studies represent a useful tool to reconstruct the pathways and the time-scale of magma ascent beneath active volcanoes. Petrological and geochemical data supply the basis for understanding the chemico-physical parameters of erupted magma evolution, and fluid inclusion geobarometry allows placing constraints on depths of magma accumulation zones in the crust. Based on this approach,a model is reported for the Island of Vulcano, which has a general applicability for other Aeolian volcanoes. The Aeolian arc consists of several recent to active volcanoes, which show variable mafic to silicic compositions and calcalkaline to shoshonitic petrochemical affinity. In most islands, such as at Vulcano, early mafic calcalkaline activity is followed by shoshonitic mafic to silicic products. Petrological studies suggest that the magmas erupted during early stages of the exposed activity (about 0.1 to 0.02 Ma) evolved by combined fractional crystallization, wall rock assimilation, and intensive mixing with mafic magmas continuously injected into the magma chamber. The younger activity tapped shallow magma chambers, in which fractional crystallization and moderate wall rock assimilation of shoshonitic basalts generated alkali rhyolites. At Vulcano, fluid inclusion data allow to identify two major magma accumulation zones located in the lower and middle crust at 21-17 km and 13-8 km depth, plus a minor one lying at 5-1 km depth. The deepest accumulation zone contains mafic melts and is located at the transition between the upper mantle and a granulitic lower crust. This reservoir has been active since the onset of the exposed volcanism, and has experienced continuous fractional crystallization, crustal assimilation and mixing with primary melts from the mantle. Slightly differentiated magmas from the deep reservoir fed accumulation zone in the middle and upper crust, or erupted directly at the surface through lateral vents. Entering of variably differentiated melts into the shallowest reservoir, located at 5-1 km depth, probably occurred shortly before magma outbreak at the surface. Similar fluid inclusion density distributions are found in other Aeolian island magmas, which leads to propose that a polybaric magma evolution occur beneath the whole Aeolian archipelago. According to our model, felsic magmas in Aeolian magmas were largely generated within magma chamber situated at middle-lower crustal depths. Magma ascent from deep-crustal magma chambers had a key role in promoting volcanic eruptions.

Frezzotti, M.; Peccerillo, A.

2008-12-01

307

Petrological studies on the mantle peridotites recovered from the ocean floor in the western Pacific  

NASA Astrophysics Data System (ADS)

Geological and geophysical models for the various oceanic crusts (or lithosphere) have been proposed on the basis of the combined studies between seismic observation for the oceanic crusts and petrological models of the onland ophiolites, which have been assumed as fossil of oceanic crusts. It is very important to collect basement rocks constituting various oceanic crusts and to characterize those petrological features. Ocean floor is commonly covered by effusive volcanic rocks, however occasionally hypabyssal and plutonic rocks are observed among the unique geological environments in the Western Pacific as partly shown in the followings. VOLCANIC DIATREME(?): Very unique volcanic knolls have been recently discovered by N. Hirano at the typical oceanic crust in the Northwestern Pacific, off Tohoku of Northeastern Japan. The constituting rocks for the main volcanic edifice are porous alkaline lavas with 1-5Ma age containing abundant lithic fragments including gabbros as well as mantle peridotites. They are assumed as a volcanic diatreme induced in the Cretaceous oceanic lithosphere . Geological and petrological analyses on those volcano and volcanic rocks can make clear the geological cross (or columnar) section of the typical oceanic lithosphere including crust as well as upper mantle down to 100 km deep asthenospheric mantle. PARECE VERA BASIN: The Parece Vela Basin (PVB) is an extinct backarc basin in the Philippine Sea. The NNE extending escarpments and depressions (maximum depth 7500 m) are fossil fracture zones and extinct segmented spreading axes (first-order segments), respectively. Oceanic core complexes (OCCs), or megamullions, develop at each first-order segment. Recently discovered OCCs at slow-spreading ridges have been interpreted as exhumed footwalls of oceanic detachment faults in magma-starved ridge environments. Godzilla Mullion, one of the OCC in the PVR, is the worlds largest OCC, 10 times larger in area than the normal OCCs in the Mid-Atlantic Ridge (Ohara et al., 2001). Various plutonic rocks including mantle peridotites were recovered from the megamullion. TONGA FOREARC: The serpentine seamounts have never been observed along the forearc, on the other hand, geological cross section is recognized along the Tonga Trench inner wall including fresh mantle peridotite. IZU-OGASAWARA(BONIN)-MARIANA FOREARC: Many topographic highs are recognized along the Izu- Ogasawara-Mariana forearc. A number of igneous rocks including lavas, gabbros and serpentinized depleted peridotites; so called ophiolitic rocks were dredged from those seamounts by several investigators, who concluded that these seamounts originated from serpentinite diapirs derived from the upper parts of the mantle wedge. Remnant mantle diapir is assumed to be the depleted source peridotite of diapiric serpentinite seamount. Tonga forearc and Izu-Ogasawara-Mariana forearc may be assumed as modern analogue of the Oman ophiolite and the Trodos ophiolite, respectively.

Ishii, T.; Hirano, N.; Ohara, Y.; Bloomer, S.

2006-12-01

308

A Collaborative Approach to Petrologic Monitoring of the Mt. Saint Helens 2004 Eruption  

NASA Astrophysics Data System (ADS)

During the first 3 weeks of MSH 2004 eruptive activity, petrologic evaluation of small amounts of volcanic ash provided our only direct means to determine if volcanic unrest was magmatic or hydrothermal in origin. Petrologic monitoring began with collection of ash from solar panels and tree leaves proximal to the crater, shortly after the initial phreatic explosive event on October 1. Within days, a network of 21 ash collection stations (later extended to 27stations), consisting of nested 5-gal buckets supported a few feet above ground-level, was deployed around the volcano at distances of 2.4 to 10 km from the vent. Much of the outer ash collection network is accessible by vehicle on forest roads within the designated hazard zone. Near-vent ash-collectors are co-located with GPS or seismic stations to facilitate collection by those monitoring teams. However, ash retrieval from most proximal stations requires helicopter transport and suitable weather conditions. Ash was collected from subsequent and more explosive steam and ash eruptions on October 4 and 5, and from steam plumes rising from the vent between October 6 and 20, at various down-wind stations. These small ash samples, often only 10ths of grams, are the only eruptive products sampled during this period of endogenous and exogenous dome growth within the crater. On October 20, samples from the base of a new lava spine in the vent area were collected using a bucket suspended from a helicopter. After each collection, samples were air-shipped to collaborators at a variety of USGS and university laboratories, and rapid turn-around of petrologic data on eruption products allowed early recognition of juvenile magmatic components. The progressive change from phreatic to magmatic attributes with time was recognized during the early phases of this eruption and helped to constrain eruption models and forecasts of volcanic hazard. An extensive database is being populated with characteristics of ash and rock samples. The MSH04 sample database will also include details of the ash collection network, prevailing winds, distribution of samples for analysis and a compilation of analytical data and images and is intended for release as a USGS open-file report.

Thornber, C.; Rowe, M.; Pallister, J.; Gooding, D.; Ramsey, D.; Ewert, J.; Couchman, M.; Dzurisin, D.; Hoblitt, R.; Clynne, M.; Lowenstern, J.; Vallance, J.; Cashman, K.

2004-12-01

309

Art in virtual reality 2010  

NASA Astrophysics Data System (ADS)

For decades, virtual reality artwork has existed in a small but highly influential niche in the world of electronic and new media art. Since the early 1990's, virtual reality installations have come to define an extreme boundary point of both aesthetic experience and technological sophistication. Classic virtual reality artworks have an almost mythological stature - powerful, exotic, and often rarely exhibited. Today, art in virtual environments continues to evolve and mature, encompassing everything from fully immersive CAVE experiences to performance art in Second Life to the use of augmented and mixed reality in public space. Art in Virtual Reality 2010 is a public exhibition of new artwork that showcases the diverse ways that contemporary artists use virtual environments to explore new aesthetic ground and investigate the continually evolving relationship between our selves and our virtual worlds.

Chang, Ben

2010-01-01

310

The relationships between petrology, porosity and permeability in the southern Sydney Basin succession, NSW.  

E-print Network

??Petrography of the Illawarra Coal Measures, Narrabeen Group and Hawkesbury Sandstone was described by thin section, scanning electron microscope and X-ray diffraction techniques. Sandstone composition… (more)

Al gahtani, Fahad Mubarak

2012-01-01

311

Theft of Virtual Property — Towards Security Requirements for Virtual Worlds  

NASA Astrophysics Data System (ADS)

The article is focused to introduce the topic of information technology security for Virtual Worlds to a security experts’ audience. Virtual Worlds are Web 2.0 applications where the users cruise through the world with their individually shaped avatars to find either amusement, challenges or the next best business deal. People do invest a lot of time but beyond they invest in buying virtual assets like fantasy witcheries, wepaons, armour, houses, clothes,...etc with the power of real world money. Although it is called “virtual” (which is often put on the same level as “not existent”) there is a real value behind it. In November 2007 dutch police arrested a seventeen years old teenager who was suspicted to have stolen virtual items in a Virtual World called Habbo Hotel [Reuters07]. In order to successfully provide security mechanisms into Virtual Worlds it is necessarry to fully understand the domain for which the security mechansims are defined. As Virtual Worlds must be clasified into the domain of Social Software the article starts with an overview of how to understand Web 2.0 and gives a short introduction to Virtual Worlds. The article then provides a consideration of assets of Virtual Worlds participants, describes how these assets can be threatened and gives an overview of appopriate security requirements and completes with an outlook of possible countermeasures.

Beyer, Anja

312

Virtual university governance.  

PubMed

There is a need to establish collaboration alliances or partnerships if we are to provide global Health Informatics educatics education. Agreements need to make provision for the existing diversity between country educational systems as well as variations in funding, legislation and political systems and a number of other issues including intellectual property and copyright. Four virtual University governance models were identified, 1) evolution of existing universities, 2) newly created organisations collectively delivering one type of program eg MBA, 3) a consortium of partners using a common portal and 4) a commercial enterprise. Collectively IMIA academic members need to be in a good position to respond to the global changes in higher education and minimise the risk of failure when establishing a virtual University to collectively deliver Health Informatics education. Others have undertaken a similar path in the past, some successful others not so, we need to learn from these experiences. PMID:15718668

Hovenga, Evelyn J S

2004-01-01

313

California Virtual Campus  

NSDL National Science Digital Library

California Virtual Campus is essentially a catalog of every virtual or technology-mediated distance education course or program offered by participating California colleges and universities. Users can search for a particular course or find information about pursuing a complete program of study from certificate level to PhD. The site summarizes important information about each course or program, such as in-state and out-of-state fees, email contacts, and registration details. For example, a search returned a list of 30 art-related course offerings at about 20 different institutions. By clicking on a title, "Visionary Artists: A Brief History of Multimedia," I found I could take this course, offered by San Francisco State University, by registering and paying a fee of $5.

314

Virtual Equine Assisted Therapy  

E-print Network

People with a wide spectrum of disabilities, ranging from spinal injuries to autism, have benefited from equine assisted therapy (EAT). Using EAT, therapy patients have improved both physically and psychologically (e.g., demonstrating increased attention, motivation, and communication skills). There are still many open questions regarding this therapy and the reasons for its success. Many of these questions have remained unanswered due in large part to the uncontrolled nature of EAT. The Virtual Equine Assisted Therapy (VEAT) Project integrates a robotic platform with virtual reality technologies to provide a safe, controlled environment through which various aspects of EAT can be isolated and studied. The system incorporates realistic equine motions with visual, auditory, olfactory, and somatosensory stimuli to provide highly immersive experiences to patients.

Fraser Anderson; Michelle Annett; Walter F. Bischof; Pierre Boulanger

315

Virtual reality systems  

NASA Technical Reports Server (NTRS)

Virtual realities are a type of human-computer interface (HCI) and as such may be understood from a historical perspective. In the earliest era, the computer was a very simple, straightforward machine. Interaction was human manipulation of an inanimate object, little more than the provision of an explicit instruction set to be carried out without deviation. In short, control resided with the user. In the second era of HCI, some level of intelligence and control was imparted to the system to enable a dialogue with the user. Simple context sensitive help systems are early examples, while more sophisticated expert system designs typify this era. Control was shared more equally. In this, the third era of the HCI, the constructed system emulates a particular environment, constructed with rules and knowledge about 'reality'. Control is, in part, outside the realm of the human-computer dialogue. Virtual reality systems are discussed.

Johnson, David W.

1992-01-01

316

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

317

Virtual images and billiards  

E-print Network

Students in introductory physics courses struggle to understand virtual image formation by a plane mirror and the proper construction of ray diagrams. This difficulty, if not sufficiently addressed, results in further problems throughout the study of geometric optics. Specifically, students fail to apply proper graphical representation of light rays during investigations of the formation of real images by converging lenses and concave mirrors. We present a guided-inquiry activity based on the research-verified Physics by Inquiry text that incorporates a small and inexpensive billiards table, with billiard balls acting as "light". In this way, we approach the abstract concept of virtual images by relation to the concrete concept of physical reflection.

Moore, J Christopher; Thompson, Cody V

2011-01-01

318

Robotic CCD Microscope for Enhanced Crystal Recognition.  

National Technical Information Service (NTIS)

A robotic CCD microscope and procedures to automate crystal recognition are studied. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of sm...

B. W. Segeike, D. Toppani

2006-01-01

319

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

320

Virtual Clinical Therapy  

Microsoft Academic Search

Virtual Reality (VR) is more than a fancy technology: it is an advanced tool for assessment and clinical therapy. On one side,\\u000a it can be described as an advanced form of human–computer interface that allows the user to interact with and become immersed\\u000a in a computer-generated environment in a naturalistic fashion. On the other side, VR can also be considered

Giuseppe Riva; Andrea Gaggioli

321

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

322

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

323

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

324

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

325

Trusting Virtual Trust  

Microsoft Academic Search

Can trust evolve on the Internet between virtual strangers? Recently, Pettit answered this question in the negative. Focusing\\u000a on trust in the sense of ‘dynamic, interactive, and trusting’ reliance on other people, he distinguishes between two forms\\u000a of trust: primary trust rests on the belief that the other is trustworthy, while the more subtle secondary kind of trust is\\u000a premised

Paul B. de Laat

2005-01-01

326

Virtual Private Network Architecture  

Microsoft Academic Search

This document describes an architecture how QoS-enabled virtual private networks over the Internet can bebuilt and managed. The basic technologies for secure VPNs and for QoS support are introduced in the firstchapter. The second chapter describes our vision of a QoS-enabled VPN service over the Internet. It also discussesin detail the required components and their interactions of an appropriate architecture.

T. Braun; M. Günter; M. Kasumi; I. Khalil

1999-01-01

327

PC\\/370 virtual machine  

Microsoft Academic Search

PC\\/370 Virtual Machine is a software package containing an IBM 370 cross assembler, linkage editor, and 370 emulator for use by students and programmers on any MS-DOS compatible PC such as the IBM PC, XT, or AT with 128K of memory. The software was originally developed in 1981 for CP\\/M-80 Z80 systems with 64K. (1) The cross assembler translates standard

Donald S. Higgins

1985-01-01

328

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

329

Living virtual history  

Microsoft Academic Search

Mondial pervasive games feature the earth’s surface as the game board with players traveling around the world like virtual\\u000a pawns in the game. ContextKing is a game that makes extensive use of sensory inputs from the real world to create a whole\\u000a new game experience within a user’s social network. We discuss the management and utilization of context data, the

Johan Koolwaaij; Martin Wibbels; Sebastian Böhm; Marko Luther

2009-01-01

330

Virtual blood bank.  

PubMed

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. PMID:21383930

Wong, Kit Fai

2011-01-01

331

Gallery of Virtual Topography  

NSDL National Science Digital Library

The Gallery of Virtual Topography features virtual depictions of topography, including 3D perspectives and QuickTime Virtual Reality (QTVR) movies, created from Digital Elevation Models (DEM's). The site showcases QTVR object movies where the user can spin a 3D terrain to view it from different perspectives. It also includes static 3D-perspective images (JPEG files) of the 3D terrains for those users with slower Internet connections. Some movies and images depict only the form of the landscape, but in others topographic contours are draped over the landscape to better illustrate how contours portray different types of topography (cliffs versus badlands, for example). Some animations illustrate the significance of contours, by allowing the user to progressively fill the landscape up with water to see the water interact with different topographic features. The site also contains a topographic contour map for each 3D terrain, so that instructors can develop student exercises, such as locating points on a map and constructing topographic profiles. Some QTVR movies contain numbered topographic features just for this purpose.

Reynolds, Stephen

332

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

333

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. PMID:21383930

Wong, Kit Fai

2011-01-01

334

Planet Alsioff - A problem set for students of phase equilibria or metamorphic petrology  

NASA Technical Reports Server (NTRS)

This paper presents a problem set that contains questions for students of phase equilibria or metamorphic petrology concerning a hypothetical planet Alsioff, for which incomplete data are given. On this panet, the SiF4 is the major volatile and Al, Si, O, and F are the only elements present. Progressive metamorphism on Alsioff mainly involves devolatilization of fluid SiF4. The problem set includes ten questions. Some of these are concerned with possible chemical reactions that should affect water, wollastonite, or Ca-SiO3 exposed to the atmosphere of Alsioff; the mechanism of controls of the O2 and F2 contents of the Alsioffian atmosphere; and the devolatilization reactions involving SiF4 with progressive thermal metamorphism.

Burt, Donald M.

1988-01-01

335

Basaltic Magmatism: The Dominant Factor in the Petrologic and Tectonic Evolution of the Earth  

NASA Technical Reports Server (NTRS)

Silicate bodies such as the Moon, Mars, probably Mercury, and possibly Venus, appear to have evolved in three main stages: a first (felsic) differentiation, a late heavy bombardment, and a second (basaltic) differentiation. It has been proposed that the Earth underwent a similar sequence. This paper argues that the second differentiation, basaltic magmatism, has dominated the petrologic and tectonic evolution of the Earth for four billion years. A global andesitic crust, formed during and after accretion of the planet, was disrupted by major impacts that triggered mantle upwelling and sea-floor spreading about 4 billion years ago. The oceanic crust collectively has since been formed by basaltic volcanism, from spreading centers and mantle plumes. However, the continental crust has also been greatly affected. Basaltic underplating has promoted anatexis and diapiric intrusion of granitoids in granite-greenstone terrains, as well as providing heat for regional metamorphism. Basaltic intrusions, such as the Nipissing diabase of the Sudbury area, have added to the thickness of continental crust. Satellite magnetic surveys suggest that there are more such basaltic intrusions than previously realized; examples include the Bangui anomaly of central Africa and the Kentucky anomaly. Basaltic overplating from mafic dike swarms has repeatedly flooded continents; had it not been for erosion, they would be covered with basalt as Venus is today. The tectonic effects of basaltic volcanism on continents have only recently been realized. The World Stress Map project has discovered that continents are under horizontal compressive stress, caused by push from mid-ocean ridges, i.e., by basaltic volcanism. The stress fields are generally uniform over large intraplate areas, and could contribute to intraplate tectonism. Seafloor spreading has demonstrably been effective for at least 200 million years, and ridge push thus a contributor to tectonic activity for that long. Collectively, the petrologic and tectonic evolution of the Earth has been dominated for about 4 billion years by the 'second differentiation,' i.e., by basaltic magmatism.

Lowman, Paul D., Jr.

2003-01-01

336

The distinct morphological and petrological features of shock melt veins in the Suizhou L6 chondrite  

NASA Astrophysics Data System (ADS)

The morphology and petrology of distinct melt veins in the Suizhou L6 chondrite have been investigated using scanning electron microscopy, electron microprobe analyses, and Raman spectroscopy, synchrotron energy-dispersive diffraction, and transmission electron microscopy. It is found that the melt veins in the Suizhou meteorite morphologically are the simplest, straightest, and thinnest among all shock veins known from meteorites. At first glance, these veins look like fine fractures, but petrologically they are solid melt veins of chondritic composition and consist of fully crystalline materials of two distinct lithological assemblages, with no glassy material remaining. The Suizhou melt veins contain the most abundant high-pressure mineral species when compared with all other veins known in chondrites. Thus, these veins in Suizhou are classified as shock veins. All rock-forming and almost all accessory minerals in the Suizhou shock veins have been transformed to their high-pressure polymorphs, and no fragments of the precursor minerals remain in the veins. Among the 11 high-pressure mineral phases identified in the Suizhou veins, three are new high-pressure minerals, namely, tuite after whitlockite, xieite, and the CF phase after chromite. On the basis of transformation of plagioclase into maskelynite, it is estimated that the Suizhou meteorite experienced shock pressures and shock temperatures up to 22 GPa and 1000 °C, respectively. Shearing and friction along shock veins raised the temperature up to 1900-02000 °C and the pressure up to 24 GPa within the veins. Hence, phase transition and crystallization of high-pressure minerals took place only in the Suizhou shock veins. Fast cooling of the extremely thin shock veins is regarded as the main reason that up to 11 shock-induced high-pressure mineral phases could be preserved in these veins.

Xie, Xiande; Sun, Zhenya; Chen, Ming

2011-03-01

337

The Distant Morphological and Petrological Features of Shock Melt Veins in the Suizhou L6 Condrite  

SciTech Connect

The morphology and petrology of distinct melt veins in the Suizhou L6 chondrite have been investigated using scanning electron microscopy, electron microprobe analyses, and Raman spectroscopy, synchrotron energy-dispersive diffraction, and transmission electron microscopy. It is found that the melt veins in the Suizhou meteorite morphologically are the simplest, straightest, and thinnest among all shock veins known from meteorites. At first glance, these veins look like fine fractures, but petrologically they are solid melt veins of chondritic composition and consist of fully crystalline materials of two distinct lithological assemblages, with no glassy material remaining. The Suizhou melt veins contain the most abundant high-pressure mineral species when compared with all other veins known in chondrites. Thus, these veins in Suizhou are classified as shock veins. All rock-forming and almost all accessory minerals in the Suizhou shock veins have been transformed to their high-pressure polymorphs, and no fragments of the precursor minerals remain in the veins. Among the 11 high-pressure mineral phases identified in the Suizhou veins, three are new high-pressure minerals, namely, tuite after whitlockite, xieite, and the CF phase after chromite. On the basis of transformation of plagioclase into maskelynite, it is estimated that the Suizhou meteorite experienced shock pressures and shock temperatures up to 22 GPa and 1000 C, respectively. Shearing and friction along shock veins raised the temperature up to 1900-2000 C and the pressure up to 24 GPa within the veins. Hence, phase transition and crystallization of high-pressure minerals took place only in the Suizhou shock veins. Fast cooling of the extremely thin shock veins is regarded as the main reason that up to 11 shock-induced high-pressure mineral phases could be preserved in these veins.

X Xie; Z Sun; M Chen

2011-12-31

338

Thermoreflectance based thermal microscope James Christoffersona  

E-print Network

Thermoreflectance based thermal microscope James Christoffersona and Ali Shakouri Jack Baskin microscope has been built which achieves 34 mK resolution for real time 1 s frames, and 0.34 K resolution is used as the basis for the thermal imag- ing microscope. This system exhibits a speedup factor of 256

339

Le microscope des mathmaticiens Tribune du Net  

E-print Network

Le microscope des mathématiciens Tribune du Net Guillaume Theyssier Laboratoire de Mathématiques chercheur TIC = Technologies de l'Information et de la Communication 2 ordinateur : le microscope des des articles : web Démonstration... #12;Ordinateur : Le microscope des mathématiciens Rappels

Theyssier, Guillaume

340

Cryogenic magnetic force microscope M. Rosemana)  

E-print Network

Cryogenic magnetic force microscope M. Rosemana) and P. Gru¨tter Centre for the Physics for publication 27 June 2000 We describe our cryogenic magnetic force microscope, operating between 4.2 and 300 K. As an effective means of vibration isolation, we suspend the microscope from a soft bellows which attenuates

Grütter, Peter

341

FINDING DOTS IN MICROSCOPIC IMAGES Elena Bernardis  

E-print Network

FINDING DOTS IN MICROSCOPIC IMAGES Elena Bernardis A DISSERTATION in Computer and Information and Computer Science, Carnegie Mellon University #12;FINDING DOTS IN MICROSCOPIC IMAGES COPYRIGHT 2011 Elena. To her, I dedicate this thesis. iv #12;ABSTRACT FINDING DOTS IN MICROSCOPIC IMAGES Elena Bernardis Stella

Plotkin, Joshua B.

342

Virtual microscopy: High resolution digital photomicrography as a tool for light microscopy simulation  

Microsoft Academic Search

Recent advances in microcomputers and high resolution digital video cameras provide pathologists the opportunity to combine precision optics with digital imaging technology and develop new educational and research tools. We review recent advances in virtual microscopy and describe techniques for viewing digital images using a microcomputer-based workstation to simulate light microscopic examination, including scanning at low power to select features

Christopher L Felten; Jonathan S Strauss; Darren H Okada; Alberto M Marchevsky

1999-01-01

343

Petrological and geochronological constraints on the metamorphic evolution of high-pressure granulites and eclogites of the Snowbird tectonic zone, Canada  

E-print Network

This thesis examines the petrology and geochronology of high-pressure granulites and eclogites within the Snowbird tectonic zone of the western Canadian Shield. The focus of this study is the East Athabasca mylonite triangle ...

Baldwin, Julia A. (Julia Ann), 1974-

2003-01-01

344

Master's opportunities at Queens College, City University of New York Master's research projects are available for motivated students in the Volcanology, Petrology, and Tectonics research  

E-print Network

Volcanic Arc, Canary Islands, western Bangladesh, and the Canadian Shield and degassing at arc and intraplate volcanoes PI: Dr. M.-A. Longpré Student research volcanoes. Projects may involve fieldwork and petrological analysis of volcanic

Johnson Jr.,, Ray

345

Martian Plains Volcanism in Syria Planum and Tempe Mareotis as Analogs to the Eastern Snake River Plains, Idaho: Similarities and Possible Petrologic Contributions to Topography  

Microsoft Academic Search

We compare martian volcanic shield topographic characteristics to topography of a similar range of shield features in the Eastern Snake River Plains of Idaho, where compositional variations are known to contribute to petrologic and topographic differences.

S. E. H. Sakimoto; T. K. P. Gregg; S. S. Hughes; J. Chadwick

2003-01-01

346

Virtual immunology: software for teaching basic immunology.  

PubMed

As immunology continues to evolve, many educational methods have found difficulty in conveying the degree of complexity inherent in its basic principles. Today, the teaching-learning process in such areas has been improved with tools such as educational software. This article introduces "Virtual Immunology," a software program available free of charge in Portuguese and English, which can be used by teachers and students in physiology, immunology, and cellular biology classes. We discuss the development of the initial two modules: "Organs and Lymphoid Tissues" and "Inflammation" and the use of interactive activities to provide microscopic and macroscopic understanding in immunology. Students, both graduate and undergraduate, were questioned along with university level professors about the quality of the software and intuitiveness of use, facility of navigation, and aesthetic organization using a Likert scale. An overwhelmingly satisfactory result was obtained with both students and immunology teachers. Programs such as "Virtual Immunology" are offering more interactive, multimedia approaches to complex scientific principles that increase student motivation, interest, and comprehension. PMID:24259333

Berçot, Filipe Faria; Fidalgo-Neto, Antônio Augusto; Lopes, Renato Matos; Faggioni, Thais; Alves, Luiz Anastácio

2013-01-01

347

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

348

Virtual Humans for Team Training in Virtual Reality  

Microsoft Academic Search

This paper describes the use of virtual humans anddistributed virtual reality to support team training,where students must learn their individual role in theteam as well as how to coordinate their actions withtheir teammates. Students, instructors, and virtualhumans cohabit a 3d, simulated mock-up of their workenvironment, where they can practice together in realisticsituations. The virtual humans can serve asinstructors for individual

Jeff Rickel; W. Lewis Johnson

1999-01-01

349

Pre-virtualization: soft layering for virtual machines  

Microsoft Academic Search

Para-virtualization ties a guest operating system and a hypervisor together, which restricts the system architec- ture; e.g., when Linux uses the Xen API, Linux is un- able to run on alternative hypervisors such as VMware, Linux itself, or a security kernel such as EROS. Further- more, the lock-in obstructs evolution of its own para- virtualization interface — virtual machines provide

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

2006-01-01

350

Virtual water: Virtuous impact? The unsteady state of virtual water  

Microsoft Academic Search

Virtual water,” water needed for crop production, is now being mainstreamed in the water policy world. Relying on virtual\\u000a water in the form of food imports is increasingly recommended as good policy for water-scarce areas. Virtual water globalizes\\u000a discussions on water scarcity, ecological sustainability, food security and consumption. Presently the concept is creating\\u000a much noise in the water and food

Dik Roth; Jeroen Warner

2008-01-01

351

Microscopic Modeling the Demographic Changes  

NASA Astrophysics Data System (ADS)

We have adapted the Penna ageing model to simulate the profound changes in the age structures of populations caused by the better life style, medical care and decrease in birth rate. In Poland, after the political transformations in the last decade of the twentieth century, the increase in the expected lifespan has been accompanied by very deep decrease in birthrate, much below the minimum necessary for keeping the constant size of the population. Our microscopic model describes the changes in the age structure which have already happened and predicts the future, assuming that our attitudes in respect to life style and social relations will not change.

Bo?kowska, Katarzyna; Szymczak, Szymon; Cebrat, Stanis?aw

352

Ballistic-Electron-Emission Microscope  

NASA Technical Reports Server (NTRS)

Ballistic-electron-emission microscope (BEEM) employs scanning tunneling-microscopy (STM) methods for nondestructive, direct electrical investigation of buried interfaces, such as interface between semiconductor and thin metal film. In BEEM, there are at least three electrodes: emitting tip, biasing electrode, and collecting electrode, receiving current crossing interface under investigation. Signal-processing device amplifies electrode signals and converts them into form usable by computer. Produces spatial images of surface by scanning tip; in addition, provides high-resolution images of buried interface under investigation. Spectroscopic information extracted by measuring collecting-electrode current as function of one of interelectrode voltages.

Kaiser, William J.; Bell, L. Douglas

1990-01-01

353

Atomic force microscope mediated chromatography.  

PubMed

An atomic force microscope (AFM) is presented as an instrument for rapid, miniaturized chromatography. The AFM is used to inject a sample, provide shear driven liquid flow over a functionalized substrate, and detect separated components. The components are then analyzed with surface enhanced Raman spectroscopy using AFM deposition of gold nanoparticles on the separated bands. This AFM mediated chromatography (AFM-MC) is demonstrated using lipophilic dyes and normal phase chemistry. A significant reduction in both size and separation time scales is achieved with 25 ?m length scale and 1 s separation times. AFM-MC has general applications to trace chemical analysis and microfluidics. PMID:23464258

Anderson, M S

2013-02-01

354

Measurement in the confocal microscope.  

PubMed

All measurements require that the microscope must be aligned as accurately as possible, and the gain (or PMT voltage) and black level must be set to avoid any overflow or underflow. Measuring surface profiles and relative depths is straightforward and can be carried out to a higher accuracy than the depth resolution of the microscopes, even though the actual images may look poor. Measuring the thickness of objects which are labeled throughout is less accurate. Length and 2D area measurements are common image analysis problems and easily carried out with image analysis software. Volume measurements are conceptually equally simple but require manual techniques or 3D analysis software. 3D surface area measurements require specialist software, or can be carried out with stereological techniques. Fluorescence intensity measurements require careful calibration. For ratiometric measurements filters and/or laser lines should be chosen to optimize the response and calibration should be done in conditions as close as possible to the experimental ones. FLIM allows exploration of the chemical environment, and multiple labelling even where spectra overlap. When the hardware is available it is also usually the method of choice for measuring FRET, which can measure molecular interactions in the nanometer range. Without FLIM hardware, either intensity measurements with correction for bleed-through and cross talk or acceptor bleaching are the most popular methods of measuring FRET. PMID:24052358

Cox, Guy

2014-01-01

355

Sensing mode atomic force microscope  

DOEpatents

An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

Hough, Paul V. C. (Port Jefferson, NY); Wang, Chengpu (Upton, NY)

2003-01-01

356

GIScience Operations with Virtual Globes  

Microsoft Academic Search

GIScience operations with 3D and 4D user-defined information is demonstrated for virtual globes using a light client on Google Earth. Shown are interactive ``point and click'' operations on 3D\\/4D objects suspended in the virtual globe environment. Such interactive operations include extraction of information from, and modification of KML\\/COLLADA models of displayed virtual objects. A Transparent Interface is introduced for Google

S. T. Shipley; S. J. Cantrell; A. Peterlin

2009-01-01

357

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.

358

The Virtual Observatory  

NASA Astrophysics Data System (ADS)

The advances in technology (telescope design and fabrication, large-scale detector arrays, computing capabilities) are permitting for the first time to explore the Universe in a multi-parameter space. Although this situation should potentially lead to a more complete and less biased understanding of complex astrophysical phenomena, the reality is that the progress in the scientific exploitation is not keeping pace with the exponential growth of data. Two are the major limiting factors: The absence of a real interoperability among astronomical archives and the lack of scalability in the classical methods of retrieving and analyzing astronomical data to tackle the new vast datasets. The Virtual Observatory is an international project aiming to solve this situation by: a) the creation of a federation of astronomical archives that, with the implementation of new technologies and standards, provides an easy and efficient access to the astronomical data (``data grid"). b) the development and implementation of analysis tools by the data centres holding the data (``service grid"). Data mining, as a way to perform an efficient and systematic study of the vast amount of information that will be available from the federation of astronomical archives, constitutes one of the key activities for the Virtual Observatory and where the greatest scientific benefits are expected to come from. Although VO is still an emerging project, it is already considered both from the technical and scientific point of view a basic requirement for the astrophysical research and the framework where to settle in the short-term the astronomical archive-related activities. The biggest data providers (NASA, ESA, ESO, ...) have understood the importance of this initiative and are already displaying their contents under the VO requirements. In this paper I will summarize some of the work areas, both from the technical and scientific point of view, that are being developed in the context of International Virtual Observatory Alliance (http://www.ivoa.net). The last part of this contribution will focus on the Spanish Virtual Observatory and its main lines of research.

Solano, E.

2006-12-01

359

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

360

The Virtual Lab Book  

NSDL National Science Digital Library

It can be a real challenge to learn about the foibles and details of lab work, so it is nice to report that Dr. Stephanie Dellis has created this excellent Virtual Lab Book for students beginning the study of molecular biology. The guide is divided into twelve parts, including "Safety in the Molecular Biology Lab", "Minipreparation of Plasmid DNA", and "PCR and Thermacycling". Along with written instructions and particulars, each section also contains a number of helpful diagrams and visual illustrations. Visitors will also want to look at the specialized lab protocols included here, such as "How to Spread a Plate" and "DNA Isolation".

361

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

362

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

363

Virtual Reality Liver Biopsy Simulator Virtual Reality, Ultrasound-guided Liver Biopsy Simulator  

E-print Network

Virtual Reality Liver Biopsy Simulator Virtual Reality, Ultrasound-guided Liver Biopsy Simulator: Development and Performance Discrimination1 Running head: Virtual Reality Liver Biopsy Simulator Word.1259/bjr/47436030 #12;Virtual Reality Liver Biopsy Simulator ABSTRACT Purpose: Identify and prospectively

Paris-Sud XI, Université de

364

Policy gaps in the virtual world  

Microsoft Academic Search

The convergence of computer and communication technologies has brought the people around the world to be more connected electronically in a virtual world. The success of Internet has opened up possibilities to create many applications in the space of the virtual world, such as the virtual libraries, the virtual shopping malls and the virtual communities, which have availed opportunities to

Muthukkaruppan Annamalai; K. M. Ehsan; N. S. N. Awang; N. A. I. N. Ahmad

2010-01-01

365

2013 Raj JainWashington University in St. Louis http://www.cse.wustl.edu/~jain/cs770-13/virtual.htm Network Virtualization:Network Virtualization  

E-print Network

Thin Client VMs Cloud Networking: Plumbing Virtual Channels, Virtual LANs, Virtual Private Networks.htm Network Virtualization:Network Virtualization: Recent DevelopmentsRecent Developments Washington://www.cse.wustl.edu/~jain/cs770-13/virtual.htm OverviewOverview 1. Virtualization: Why, How? 2. Recent Networking Virtualization

Jain, Raj

366

Modeling autonomous virtual agent in virtual environment for risk behavior  

Microsoft Academic Search

Owing to the complexity of human behaviors in risk situation and the harsh physical environment of underground mine, current researches on coalmine virtual environment have paid little attention on modeling human risk behaviors. Based on Artificial Life method, an intelligent virtual miner agent model was proposed to yield better understandings of human factors in emergency situation and to assist risk

Cai Linqin; Li Huijuan; Luo Zhiyong; Tang Xianlun

2010-01-01

367

Virtual Hagia Sophia: Restitution, Visualization and Virtual Life Simulation  

Microsoft Academic Search

This paper presents a case study centered on the virtual restitution and virtual life simulation of a highly complex and endangered heritage edifice: the church of Hagia Sophia, in Istanbul, Turkey (added in 1996 in the annual list of endangered monuments by the World Monuments Watch). The goal of this article is to describe the techniques used in order to

Alessandro E. FONI; George PAPAGIANNAKIS; Nadia MAGNENAT-THALMANN

368

Virtual devices: tools to remotely develop virtual environments  

NASA Astrophysics Data System (ADS)

Virtual environments as an aid for scientific discovery are becoming a topic of research for many visualization efforts. Virtual environments provide greater immersion into the world or environment of scientific data, thereby enhancing the researcher's perception of its features and forms. However, access to laboratories with the appropriate hardware for providing the immersive environments is currently limited. To make the best use of limited lab time a scientist will want to spend as much of it as possible actually looking at the data, and not debugging the virtual world source code. In an effort to get the scientist close to achieving this goal, we have developed software to emulate a suite of standard virtual environment hardware devices. Emulated hardware is designed such that it is indistinguishable to the application software. Communications with the `virtual devices' is via a serial port using the same protocol as the physical devices. Some `virtual devices' have already been written. We are now making efforts to have virtual environment programmers use them to design and test applications without using much of the increasingly precious time in the NCSA Virtual Reality Laboratory.

Sherman, William R.

1994-04-01

369

Calc-alkaline lavas from the volcanic complex of Santorini, Aegean Sea, Greece : a petrological, geochemical and stratigraphic study  

Microsoft Academic Search

This thesis presents the results of a petrological-geochemical- and\\u000astratigraphic study of the calc-alkaline lavas from Santorini, Aegean\\u000aSea, Greece. The volcanic complex of Santorini consists of seven\\u000aeruption centres, of which some have been active contemporaneous. The\\u000aeruption centres in the northern part of Santorini mainly produced lava\\u000aflows in contrast with a long-lived eruption centre in the southern

J. P. P. Huijsmans

1985-01-01

370

Weathering of Igneous, Metamorphic, and Sedimentary Rocks in a Semi-arid Climate - An Engineering Application of Petrology  

NASA Astrophysics Data System (ADS)

Over the last 10 years, analytical methods have been introduced to students in CSM's undergraduate geological engineering program through a multi-year and multi-course approach. Beginning with principles and simple applications of XRD and SEM in sophomore Mineralogy and building on these skills in subsequent junior and senior year courses, geological engineers acquire proficiency in analytical methods. Essential workplace skills are thus acquired without adding an extra course in the undergraduate program. The following exercise is completed by juniors in an integrated Ig.-Met.-Sed. petrology course. The identification of clay mineral assemblages in soils provides a unique opportunity to demonstrate how basic principles of petrology and geochemistry are applied to engineering design criteria in construction site preparation. Specifically, the problem investigates the conditions leading to the formation of smectite in soils and the resulting construction risk due to soil expansion. Students examine soils developed on igneous, metamorphic, and sedimentary rocks near Denver, Colorado. The field locations are areas of suburban growth and several have expansive soil problems. The 2-week exercise includes sample collection, description, and preparation, determining clay mineralogy by XRD, and measurement of Atterberg Plasticity Indices. Teaching materials may be found at: http://serc.carleton.edu/NAGTWorkshops/petrology03/. This exercise accomplishes three objectives: First, skills in XRD analysis are developed by introducing students to concepts of particle size separation, particle orientation, and sequential analysis steps which are standard practices in clay characterization. Second, lecture material on the geochemistry of weathering of different rock types is reinforced. Students interpret the origin of clay mineral assemblages developed in soils derived from Precambrian gneisses, lower Paleozoic feldspathic sandstones, upper Paleozoic marine shales, and Tertiary basalts and volcaniclastics. Third, the role of petrologic characterization in site engineering is demonstrated. Students use Atterberg Limits measurements in conjunction with soil mineralogy to assess swelling potential and to design soil treatment needs for each building site.

Harrison, W. J.; Wendlandt, R. F.

2003-12-01

371

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.

372

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

373

Ergito: Virtual Text  

NSDL National Science Digital Library

Ergito's Virtual Text, started in 2000, was created to provide a more timely and interactive alternative to printed scientific textbooks at the undergraduate and graduate level. This still-developing Web site covers life science writ large, including molecular biology, cell biology, genetics, biochemistry, immunology, and so on. However, only a small number of features are available free of charge. The first chapter of the molecular biology module -- Genes are DNA -- is available for free, as is Great Experiments, a collection of essays written by authors who conducted original research that has contributed greatly to our understanding of molecular and cellular biology. Great Experiments has a recently added essay by 2001 Nobel Prize winner Paul Nurse, titled "The Discovery of cdc2 as the Key Regulator of the Cell Cycle." These essays are formatted just as the Virtual Text pages are, with downloadable figures, a glossary, an online note-taking feature (notes are automatically compiled with a summary of the essay), glossary, and more. Ergito will soon make available Techniques, another free feature offering descriptions of widely used experimental protocols. Even without free access to the larger body of material in this Web site, Ergito is a fantastic resource for learning about molecular and cellular biology. Users must complete a free registration process to access this Web site.

2000-01-01

374

Tours in Virtual Globes  

NASA Astrophysics Data System (ADS)

The most significant new feature to appear in Google Earth 5.0 in February was the tour feature, it can produce eye catching and appealing animations as was shown by the Apollo 11 Tour which shows a model of the lunar module descending to the surface of the moon. It allows users to record themselves navigating around Google Earth switching elements on and off. The use of the tour functionality goes beyond exciting animations, it has important applications as a way of; introducing users to a larger data set presented in a Virtual Globe, offering an alternative to PowerPoint as a platform to support presentations and as a quick way to produce powerful visualizations for education purposes. In this talk I will explore how best to use to tours to present a range of spatial data and examine how the Google Earth tour compares to similar functionality that is appearing in other Virtual Globes and other 3D environments such as Second Life.

Treves, R.

2009-12-01

375

Atomic force microscope: Enhanced sensitivity  

SciTech Connect

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. Fiber-optic interferometer techniques developed at LLNL offer the potential of improving the vertical resolution of these instruments by up to 2 orders of magnitude. We are attempting to replace the current AFM measurement scheme, which consists of an optical beam deflection approach, with our fiber-optic interferometer scheme, a much more sensitive displacement measurement technique. In performing this research, we hope to accomplish two important goals; (1) to enhance the sensitivity of the AFM, and (2) to achieve important improvements in our fiber-optic interferometer technology.

Davis, D.T.

1995-06-01

376

Petrologic model of the northern Mississippi Embayment based on satellite magnetic and ground-based geophysical data  

NASA Technical Reports Server (NTRS)

A petrologic model of the northern Mississippi Embayment, derived from gravity, seismic and rift data, is evaluated by converting the model to a magnetization model which is compared with satellite magnetic anomaly models. A magnetization contrast of approximately -0.54 A/m, determined from the petrologic model of the embayment compares favorably to values of -0.62 A/m and -0.45 A/m from a Magsat United States Apparent Magnetization Contrast Map and a published POGO magnetization contrast model, respectively. The petrologic model suggests that the magnetic anomaly low associated with the Mississippi Embayment may be largely due to the intrusion under non-oxidizing conditions of low Curie temperature gabbroic material at the base of the crust of the embayment. Near-surface mafic plutons, bordering the Mississippi Valley Graben, appear from aeromagnetic data to have higher magnetizations than the deeper gabbroic material; however, it is impossible to ascertain if this is due to compositional differences or similar material at shallower (lower temperature) depths. These results indicate that variations in the Curie temperatures of intrusions accompanying rifting may account for a large part of the wide range of magnetic anomalies associated with presently inactive rifts with normal heat flow.

Thomas, H. H.

1984-01-01

377

Petrologic model of the northern Mississippi Embayment based on satellite magnetic and ground-based geophysical data  

NASA Astrophysics Data System (ADS)

A petrologic model of the northern Mississippi Embayment, derived from gravity, seismic and rift data, is evaluated by converting the model to a magnetization model which is compared with satellite magnetic anomaly models. A magnetization contrast of approximately -0.54 A/m, determined from the petrologic model of the embayment compares favorably to values of -0.62 A/m and -0.45 A/m from a Magsat United States Apparent Magnetization Contrast Map and a published POGO magnetization contrast model, respectively. The petrologic model suggests that the magnetic anomaly low associated with the Mississippi Embayment may be largely due to the intrusion under non-oxidizing conditions of low Curie temperature gabbroic material at the base of the crust of the embayment. Near-surface mafic plutons, bordering the Mississippi Valley Graben, appear from aeromagnetic data to have higher magnetizations than the deeper gabbroic material; however, it is impossible to ascertain if this is due to compositional differences or similar material at shallower (lower temperature) depths. These results indicate that variations in the Curie temperatures of intrusions accompanying rifting may account for a large part of the wide range of magnetic anomalies associated with presently inactive rifts with normal heat flow.

Thomas, H. H.

1984-09-01

378

Petrology-based modeling of mantle melt electrical conductivity and joint interpretation of electromagnetic and seismic results  

NASA Astrophysics Data System (ADS)

presence of melt in the Earth's interior depends on the thermal state, bulk chemistry, and dynamics. Therefore, the investigation of the physical and chemical properties of melt is a probe of the planet's structure, dynamics, and potentially evolution. Here we explore melt properties by interpreting geophysical data sets sensitive to the presence of melt (electromagnetic and seismic) with considerations of petrology and, in particular, peridotite partial melting. We present a petrology-based model of the electrical conductivity of fertile and depleted peridotites during partial melting. Seismic and magnetotelluric (MT) studies do not necessarily agree on melt fraction estimates, a possible explanation being the assumptions made about melt chemistry as part of MT data interpretation. Melt fraction estimates from electrical anomalies usually assume a basaltic melt phase, whereas petrological knowledge suggests that the first liquids produced have a different chemistry, and thus a different conductivity. Our results show that melts produced by low-degree peridotite melting (< 15 vol %) are up to 5 times more conductive than basaltic liquids. Such conductive melts significantly affect bulk rock conductivity. Application of our electrical model to magnetotelluric results suggests melt fractions that are in good agreement with seismic estimates. With the aim of a simultaneous interpretation of electrical and seismic data, we combine our electrical results with seismic velocity considerations in a joint model of partial melting. Field electrical and seismic anomalies can be explained by ~1 vol % melt beneath Hawaii and ~1-8 vol % melt beneath the Afar Ridge.

Pommier, A.; Garnero, E. J.

2014-05-01

379

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

380

Mineralogy and Petrology of Basement Granites of the Cooper Basin, Central Australia  

NASA Astrophysics Data System (ADS)

Mineralogy and Petrology of Basement Granites of the Cooper Basin, Central Australia Although the Australian continent is tectonically relatively stable in comparison with other continental settings, the radiogenic heat production within the Australian continental crust is significantly high. One region with particularly elevated heat production is the Cooper Basin. The Cooper basin is an intra-cratonic basin that contains Late Carboniferous to middle Triassic sedimentary rocks which is mainly comprised of non marine sediments. The Cooper Basin overlies granites which have intruded the Warburton Basin Sediments. The Cooper basin in turn is overlain by the Eromanga Basin. This paper focuses on four deep wells in which granites have been intersected. The aim of this study is to characterize the mineralogy and petrology of the granites to further the understanding of heat production. Ten petrographic thin-sections were made from the granites and sampled at different depths in the four geothermal wells. Eight (Big Lake-3507; McLeod-1-3745.2, 3745.9, 3748.3; Moomba-1 2847.75, 2848.7, 2851, 2847.4) of the ten samples exhibit minor to strong alteration, with the other two remaining samples (Jolokia-1 4905 and Moomba-1 2857.4) showing only slight alteration. The predominant mineral in the altered samples is quartz, and a highly birefringent clay mineral (illite from EPMA and XRD) with minor oxides (Goethite, Rutile) sulphides (Galena, Pyrite) and REE-rich silicates (Thorite, Zircon) and phosphates (Apatite, Monazite and Xenotime). The sections exhibiting minor alteration contain plagioclase and K-feldspar in varying stages of decomposition. These feldspars contain varying amounts of illite crystallites. The only altered mineral in the two slightly altered samples is biotite. In Jolokia 1- 4905 the biotite has been completely replaced by a Fe-bearing illite. In Moomba 1- 2857.4 the biotite is only in the early stages of alteration, with the alteration product being Fe-chlorite. Considering all the thin sections, three textures were identified based on mineralogy and grain size. The first texture is the primary granite texture, which is evident in the low alteration samples and is also observed in the altered samples through the large grain size of some quartz grains (> 2mm). The primary quartz in these samples is highly fractured with extensive undulose extinction and planar deformation features. The second texture is an intermediate pseudomorphic texture after the alteration of biotite into a larger, more crystalline illite. This texture is characterized by the clay minerals having a grain size between 200 µm and 1 mm. The third texture is the more pervasive alteration. This is exhibited by the finely (< 100µm) inter-grown clay minerals and associated fine-grained quartz. In addition to the petrology, the illite crystallinity values were measured in the granites and the overlying sediments. They broadly indicate that temperatures during the hydrothermal process in the granite ranged from 250?C (in Moomba 1 and Big Lake 1) to 350?C (in McLeod 1 and Jolokia 1). The crystallinity of the illite in the sedimentary rocks is lower in comparison to those in the granite samples. Together with the occurrence of chlorite and kaolinite in the sediments, this indicates that the sediments and the underlying granite were subjected to different fluid chemistries and temperature regimes. Thin section optical microscopy also shows that the granites have been severely fractured, and that the fracturing was accompanied by significant hydrothermal alteration. Fracturing in the granite occurs mostly as irregular micro-fractures and veining, as well as planar micro-deformation structures in quartz. This indicates that the granite has been subjected to a significantly high stress regime of an unknown origin with subsequent hydrothermal fluid circulation. Hydrothermal alteration mineralogy consists of largely a single phyllosilicate phase (illite). In many cases, all feldspars and micas in the granite have been completely altered

van Zyl, Jaco; Gasparon, Massimo; Uysal, Tonguc

2010-05-01

381

Static virtual channel allocation in oblivious routing  

E-print Network

Most virtual channel routers have multiple virtual channels to mitigate the effects of head-of-line blocking. When there are more flows than virtual channels at a link, packets or flows must compete for channels, either ...

Shim, Keun Sup

382

PORTING LEGACY APPLICATIONS TO IMMERSIVE VIRTUAL ENVIRONMENTS  

E-print Network

PORTING LEGACY APPLICATIONS TO IMMERSIVE VIRTUAL ENVIRONMENTS A Case Study Kenny Gruchalla, virtual reality, software engineering, biology. Abstract: Immersive virtual environments are becoming increasingly common, driving the need to develop new software or adapt existing software to these environments

Gruchalla, Kenny

383

Webinars at Louisiana Virtual School  

ERIC Educational Resources Information Center

Delivering meaningful professional development, engaging students in exciting yet practical curricula, and effectively communicating with faculty and staff members are challenges in any school setting. At the Louisiana Virtual School, a state-funded virtual school run by the Louisiana Department of Education, the 6,000 students, 115 instructors,…

Grant, Allen

2009-01-01

384

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

385

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

386

When Rural Reality Goes Virtual.  

ERIC Educational Resources Information Center

In rural towns where sparse population and few business are barriers, virtual reality may be the only way to bring work-based learning to students. A partnership between a small-town high school, the Ohio Supercomputer Center, and a high-tech business will enable students to explore the workplace using virtual reality. (JOW)

Husain, Dilshad D.

1998-01-01

387

Designing a Virtual Field Trip  

ERIC Educational Resources Information Center

Virtual field trips offer a new way for teachers and students to visit historical sites and museums. Most notably, virtual field trips provide access to places that normally would be impossible for classrooms to visit, and this, in turn, provides a plethora of learning possibilities for the classroom. Why should teachers consider creating a…

Lacina, Jan Guidry

2004-01-01

388

Adolescent Attitudes towards Virtual Learning  

ERIC Educational Resources Information Center

This study was designed to examine adolescents' attitudes towards virtual schooling. Virtual schooling may be defined as any public or private organization that delivers instruction via the Internet. The rationale for this study is based on the increased number of adolescents opting to complete some or all of their secondary education through…

Pleau, Andrea R.

2012-01-01

389

Virtual Schools. Trends and Issues.  

ERIC Educational Resources Information Center

This article looks at a rapidly growing form of distance education: virtual schools. Also known as cyber schools, these Internet-based programs enroll fewer than 50,000 students nationwide, but more and more companies are entering this market. Some examples of these virtual schools are the Willoway CyberSchool, which was founded by a former…

Hadderman, Margaret

390

Virtual Patients in Pharmacy Education  

PubMed Central

A review of the literature relating to the use of virtual patients in teaching pharmaceutical care to pharmacy students was conducted. Only 7 articles met the inclusion criteria for the review and 4 of the studies were conducted in North America. Few articles identified by the review used virtual patient technology that was true-to-life and/or validated. PMID:22761533

Jabbur-Lopes, Monique O.; Mesquita, Alessandra R.; Silva, Leila M. A.; De Almeida Neto, Abilio

2012-01-01

391

Virtual Reality, Art and Entertainment  

Microsoft Academic Search

Most existing research on virtual reality concerns issues close to theinterface, primarily how to present an underlying simulated world in aconvincing fashion. However, for virtual reality to achieve its promise as arich and popular artistic form, as have the novel, cinema, and television,we believe it will be necessary to explore well beyond the interface, to thoseissues of content and style

Joseph Bates

1992-01-01

392

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

393

Virtual reality orthopedic surgery simulator  

Microsoft Academic Search

This paper describes a highly interactive virtual reality orthopedic surgery simulator. The simulator allows surgeons to use various surgical instruments to operate on virtual rigid anatomic structures, such bones, prostheses and bone grafts, to simulate every procedure on the rigid structures for complex orthopedic surgeries, including arthroplasty, corrective or open osteotomy, open reduction of fractures and amputation. A comparative study

Ming-Dar Tsai; Ming-Shium Hsieh; Shyan-Bin Jou

2001-01-01

394

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

395

Teaching Education and the Virtual  

ERIC Educational Resources Information Center

This text weighs the ethical consequences of a virtual education that posits a learning community based on the free exchange of ideas and the economy of knowledge cultivating the circulation of ideas. It explores the ethical implications of a virtual educational enterprise characterised by exchanges that do not take place face to face but are…

Trifonas, Peter Pericles; Despres, Blane

2004-01-01

396

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.

397

Virtual Recovery of Excavated Relics  

Microsoft Academic Search

Bringing computer graphics and virtual reality technologies to traditional archaeology raises surprising possibilities. First, it permits exploring, assembling, and visualizing relics without disturbing their physical location or damaging specimens. Second, it brings a “what if” scenario to the task of reassembling fragments, which would otherwise involve applying permanent adhesives, rendering mistakes irrevocable. Virtual recovery affords an opportunity to previsualize alternatives

Jiang Yu Zheng; Zhong Li Zhang

1999-01-01

398

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

399

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

400

Virtually conquering fear of flying  

Microsoft Academic Search

Traditional approaches to exposure therapy include imaginal (the patient imagines the stimulus) exposure and in vivo (the patient is exposed to the actual physical situation) exposure. Virtual reality exposure, in which the patient is exposed to a virtual environment containing the feared stimulus, has been shown in a controlled study to be an effective treatment approach for acrophobia (the fear

L. F. Hodges; B. A. Watson; G. D. Kessler; B. O. Rothbaum; D. Opdyke

1996-01-01

401

Overview of virtual intelligence (VI)  

NASA Astrophysics Data System (ADS)

Virtual Intelligence (VI) is defined as neural networks, fuzzy systems, evolutionary computation and virtual reality. This overview provides motivational material and an update on research. Some potential interactions of VI components are described. Hot topics and new approaches such as Pulse Coupled Neural Networks are reviewed. Pointers to websites and printed material are provided.

Padgett, Mary Lou

1999-03-01

402

Dynamic Virtual Credit Card Numbers  

Microsoft Academic Search

Theft of stored credit card information is an increasing threat to e-commerce. We propose a dynamic virtual credit card number scheme that reduces the damage caused by stolen credit card numbers. A user can use an existing credit card account to generate multiple virtual credit card numbers that are either usable for a single transaction or are tied with a

Ian Molloy; Jiangtao Li; Ninghui Li

2007-01-01

403

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

404

Enhancing Spiritualism in Virtual World  

ERIC Educational Resources Information Center

Spiritualism is one word which puts man on the highest plinth of life. Spirituality is the way we find meaning, hope, comfort and inner peace in life. Spirituality in the virtual World is generally known as Virtual Spirituality. A goldmine of wisdom from all kinds of religious and spiritual philosophies, traditions and practices can be found in…

Dangwal, Kiran Lata; Singh, Shireesh Pal

2012-01-01

405

Vapor Saturation and Magma Degassing: Integrating Petrologic and Remote Sensing Perspectives on Volcanic Volatile Budgets  

NASA Astrophysics Data System (ADS)

Over the past 25 years there has been a growing body of evidence based on petrologic, remote sensing, and volcanic gas data that andesitic, dacitic, and rhyolitic magmas in crustal reservoirs are saturated with a multicomponent C-O-H-S vapor phase before eruption. A key piece of evidence for magmatic vapor saturation is the excess S problem: the common observation that much more S is released by explosive eruptions than was originally dissolved in the erupted volume of silicate melt. If all of the excess S is derived from a magmatic vapor phase, then intermediate to silicic magmas must commonly contain several wt% exsolved vapor prior to eruption. The large amounts of volatiles implied by these estimates suggest that exsolved vapor accumulates in the apical regions of magma bodies during repose periods between eruptions. A major uncertainty in understanding volcanic SO2 emissions has been lack of information on S partitioning between silicate melt and coexisting hydrous vapor. Recently published experimental data on melt-vapor partitioning (Scaillet et al., 1998; Keppler, 1999) have shown that S partitions strongly into the vapor phase under conditions relevant for most dacitic and rhyolitic magmas. Thermodynamic modeling (Wallace, 2000) based on these results can be used to calculate the mole fractions of both SO2 and H2S in a magmatic vapor phase if temperature, pressure, oxygen fugacity, and dissolved H2O and S contents of the silicate melt are known. Using published data for well studied eruptions, the pre-eruptive magmatic vapor phase for dacitic to rhyolitic magmas typically contains 0.5 to 6 mol% total S. Andesitic, dacitic, and rhyolitic magmas in crustal reservoirs are probably vapor saturated due to recharge and underplating by vapor-saturated basaltic magma. CO2 is particularly important because it is abundant in mantle derived basalts but has low solubility in silicate melts at crustal pressures. Understanding budgets of the major volatiles requires integrating remote sensing and volcanic gas data on fluxes of CO2, SO2, and H2S from volcanoes with petrologic data on temperature, pressure, oxygen fugacity, and dissolved volatiles in both differentiated magma stored in crustal reservoirs and mafic magma recharging these systems. The importance of the latter is exemplified by mafic cinder cones surrounding Popocatepetl volcano in central Mexico. Olivine-hosted melt inclusions from these cones contain 1000-6000 ppm S (Cervantes and Wallace, 2000), indicating that mafic magma recharging into the Popo system provides an abundant source of S that may explain the very large SO2 emissions from the current eruption.

Wallace, P.

2002-05-01

406

A New Approach to Teaching Petrology: Active Learning in a Studio Classroom  

NASA Astrophysics Data System (ADS)

During the past 15 years it has become clear that the traditional lecture and lab approach to college science teaching leaves much to be desired. The traditional approach is instructor oriented and based on passive learning. In contrast, current studies show that most students learn best when actively engaged in the learning process. Inquiry based learning and open ended projects have been shown to especially enhance learning by promoting higher order thinking. Recognizing the need for change, however, does not mean the changes are simple. The task of overhauling a course, replacing traditional approaches with more student oriented activities, requires a great deal of time and effort. It also involves much uncertainty and risk. At UND we have been experimenting with alternative pedagogies for a number of years. Change has been incremental, but this year we made wholesale changes in our petrology class. We converted it from the standard three lecture and one lab format to two 3-hour studio sessions per week. The distinction between lab and lecture is gone. In fact, there really are no lectures. The instructor talks for no more than 15 or 20 minutes at a time. Students spend most of their time doing, not listening. We emphasize collaborative active learning projects, some quite short and others lengthy and involved, and use a wide variety of activities. To assess the class, we have an outside consultant and we carry out weekly assessments to measure (1) how students are reacting to the various pedagogical approaches, and (2) how much student learning is actually occurring. This allows us to make adjustments and fine tune as necessary. We could not have made such changes a few years ago, simply because of the amount of work involved to create and test the necessary classroom materials. Today, however, there are many resources available to the reform minded teacher, and the resource base continues to grow. We borrowed heavily from other instructors at other institutions. We mined the Journal of Geoscience Education for teaching and assessment strategies. We took many ideas for projects from the recent Teaching Petrology Workshop (July 2003, one of the On the Cutting Edge: Workshops for Geoscience Faculty, supported by the NAGT, DLESE and NSF/DUE). With more workshops and meetings devoted to teaching reform, and as geoscientists further develop their scholarship of teaching and learning, reforming our classes will become easier. The result will not only be better educated students, but also a greater retention of geoscience majors.

Perkins, D.

2003-12-01

407

Radio-induced alteration in cordierite - Implications for petrology, gemmology and materials science  

NASA Astrophysics Data System (ADS)

Cordierite is a common metamorphic and magmatic mineral, which is used as petrologic tool for reconstructing the history of its host rock. Further applications include cordierite gemstones and the use of synthetic analogs in ceramics. Cordierite is stable over a wide temperature and pressure range and relatively resistant to chemical alteration; however, its properties can be significantly changed upon the impact of external irradiation. In the course of a comprehensive study, natural radiohaloes in cordierite (a widespread feature caused by the impact of alpha-particles originating from radioactive inclusions) as well as artificial analogs produced by implantation of 8.8 MeV He2+ ions were investigated using modern micro-techniques. Additional irradiation experiments were performed using O6+ ions, electrons and gamma-rays. Ion irradiation causes yellow colouration that is strongly pleochroic, and fades at higher doses. The possibility of radiation-treatment for enhancing the quality of gem-cordierite is discussed. While samples remain crystalline up to doses of 1016 He2+/cm2, the same material is fully amorphised when irradiated with the same dose of 30 MeV O6+ ions. These different observations may help to estimate the performance assessment of cordierite-ceramics in radiated environments. A very important result concerning the petrological use of cordierite is the radio-induced transformation of channel constituents: Inside the irradiated areas the vibrational bands of CO2 decrease in intensity, whereas two new bands appear at 2135 cm-1 (both IR- and Raman-active; cf. Nasdala et al., 2006) and 1550 cm-1 (only Raman-activ). They are assigned to stretching vibrations of carbon monoxide and molecular oxygen, respectively, thus indicating a radio-chemical transformation 2CO2 ? 2CO + O2 in alpha-irradiated cordierite. This study yields the first spectroscopic evidence for the irradiation-induced formation of molecular oxygen in cordierite. Polarised vibrational spectra of oriented samples give evidence that not only CO2 but also CO and O2 are preferentially oriented parallel [100], most probably being located at the Ch

Krickl, R.; Nasdala, L.; Grambole, D.; Kaindl, R.

2009-04-01

408

Notion of a virtual derivative  

E-print Network

Diagrams as a graphic expresion of derivatives is proposed for calculation of derivatives for composed function. The concret diagram is understood as a virtual derivative in contrast of concret derivative. In polynomial expression of functions derivative the concret derivative will be every monomic member, and the virtual derivative represent the sum of similar monomic members. The word virtual denotes that we dont need to know every virtual derivative, we don't write all the sequence of these virtual derivatives, and simply pick the needed one. This is in contrast of tradition to write the whole algebraic expresion as a denotion of whole function's derivative. Such graphic expresion can be helpful in the problems of differential geometry, in the various asymptotic expantions, also in the solution of some differential equations.

Gintaras Valiukevicius

2011-01-04

409

Biological imaging with a neutron microscope  

Microsoft Academic Search

A simple microscope employing a compound refractive lens (CRL) composed of 100 biconcave lenses was used to image a biological sample with a 9.4× magnification using 10 A? cold neutrons. The microscope’s resolution, 0.5 mm, was primarily determined by the neutron detector 5.0 mm pixel size. Unlike previous work the CRL’s field of view was large (44 mm) and increased

J. T. Cremer; M. A. Piestrup; C. K. Gary; R. H. Pantell; C. J. Glinka

2004-01-01

410

Designing and Embedding Reliable Virtual Infrastructures  

Microsoft Academic Search

In a virtualized infrastructure where physical resources are shared, a single\\u000aphysical server failure will terminate several virtual servers and crippling\\u000athe virtual infrastructures which contained those virtual servers. In the worst\\u000acase, more failures may cascade from overloading the remaining servers. To\\u000aguarantee some level of reliability, each virtual infrastructure, at\\u000ainstantiation, should be augmented with backup virtual nodes

Wai-Leong Yeow; Cédric Westphal; Ulas C. Kozat

2010-01-01

411

Foldscope: Origami-based paper microscope  

E-print Network

Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education.

Cybulski, James; Prakash, Manu

2014-01-01

412

Foldscope: origami-based paper microscope.  

PubMed

Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education. PMID:24940755

Cybulski, James S; Clements, James; Prakash, Manu

2014-01-01

413

Scanning evanescent electro-magnetic microscope  

DOEpatents

A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Anhui, CN); Schultz, Peter G. (La Jolla, CA); Wei, Tao (Sunnyvale, CA)

2003-01-01

414

Scanning evanescent electro-magnetic microscope  

DOEpatents

A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Alameda, CA)

2001-01-01

415

Virtual Interactive Classroom: A New Technology for Distance Learning Developed  

NASA Technical Reports Server (NTRS)

The Virtual Interactive Classroom (VIC) allows Internet users, specifically students, to remotely control and access data from scientific equipment. This is a significant advantage to school systems that cannot afford experimental equipment, have Internet access, and are seeking to improve science and math scores with current resources. A VIC Development Lab was established at Lewis to demonstrate that scientific equipment can be controlled by remote users over the Internet. Current projects include a wind tunnel, a room camera, a science table, and a microscope.

York, David W.; Babula, Maria

1999-01-01

416

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.

417

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.

418

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

419

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.

420

Virtual Pig Dissection  

NSDL National Science Digital Library

Dissection can be an aspect of scientific education that can make some parties queasy, but it is a fascinating way to learn more about the different body systems, their operations, and basic animal anatomy. Entering the world of pig dissection can make budding scientists even more squeamish, but they need never fear, as this site allows these individuals the opportunity to engage in a bit of virtual pig dissection. Originally created by Professor Earl W. Fleck of Whitman CollegeâÂÂs biology department, the site lets users go inside the pig to learn about its various systems, via a set of high-quality color photographs, which can be viewed at different angles and perspectives. Of course, what would a lab be without a quiz? Rounding out the site, visitors can take short quizzes on the pigâÂÂs anatomy and such.

Fleck, Earl W.

421

Primitive Virtual Negative Charge  

E-print Network

Physical fields, such as gravity and electromagnetic field, are interpreted as results from rearrangement of vacuum particles to get the equilibrium of net charge density and net mass density in 4-dimensional complex space. Then, both fields should interact to each other in that physical interaction is considered as a field-to-field interaction. Hence, Mass-Charge interaction is introduced with primitive-virtual negative charge defined for the mass. With the concept of Mass-Charge interaction electric equilibrium of the earth is discussed, especially about the electric field and magnetic field of the earth. For unsettled phenomena related with the earth's gravity, such as antigravity phenomenon, gravity anomalies during the solar eclipses, the connection between geomagnetic storms and earthquakes, etc., possible explanations are discussed.

Kiyoung Kim

2008-11-04

422

Primitive Virtual Negative Charge  

E-print Network

Physical fields, such as gravity and electromagnetic field, are interpreted as results from rearrangement of vacuum particles to get the equilibrium of net charge density and net mass density in 4-dimensional complex space. Then, both fields should interact to each other in that physical interaction is considered as a field-to-field interaction. Hence, Mass-Charge interaction is introduced with primitive-virtual negative charge defined for the mass. With the concept of Mass-Charge interaction electric equilibrium of the earth is discussed, especially about the electric field and magnetic field of the earth. For unsettled phenomena related with the earth's gravity, such as antigravity phenomenon, gravity anomalies during the solar eclipses, the connection between geomagnetic storms and earthquakes, etc., possible explanations are discussed.

Kim, Kiyoung

2008-01-01

423

Virtual acoustics displays  

NASA Technical Reports Server (NTRS)

The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

1991-01-01

424

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.

425

The virtual observatory registry  

NASA Astrophysics Data System (ADS)

In the Virtual Observatory (VO), the Registry provides the mechanism with which users and applications discover and select resources-typically, data and services-that are relevant for a particular scientific problem. Even though the VO adopted technologies in particular from the bibliographic community where available, building the Registry system involved a major standardisation effort, involving about a dozen interdependent standard texts. This paper discusses the server-side aspects of the standards and their application, as regards the functional components (registries), the resource records in both format and content, the exchange of resource records between registries (harvesting), as well as the creation and management of the identifiers used in the system based on the notion of authorities. Registry record authors, registry operators or even advanced users thus receive a big picture serving as a guideline through the body of relevant standard texts. To complete this picture, we also mention common usage patterns and open issues as appropriate.

Demleitner, M.; Greene, G.; Le Sidaner, P.; Plante, R. L.

2014-11-01

426

Virtual reality and anthropology.  

PubMed

Since the discovery of the Tyrolean Iceman in 1991 advanced imaging and post processing techniques were successfully applied in anthropology. Specific techniques include spiral computed tomography and 3-dimensional reconstructions including stereolithographic and fused deposition modeling of volume data sets. The Iceman's skull was the first to be reproduced using stereolithography, before this method was successfully applied in preoperative planning. With the advent of high-end graphics workstations and biomedical image processing software packages, 3-dimensional reconstructions were established as a routine tool for analyzing volume data sets. These techniques opened totally new insights in the field of physical anthropology. Computed tomography became the ideal research tool to access the internal structures of various precious fossils without damaging or even touching them. Many of the most precious specimens from the species Autralopithecus (1.8-3.5 Myears), Homo heidelbergensis (200-600 kyears) or Homo neanderthalensis (40-100 kyears) were scanned during the last 5 years. Often the fossils are filled with a stone matrix or other materials. During the postprocessing routines highly advanced algorithms were used to remove virtually these incrustations. Thus it was possible to visualize the morphological structures that lie beneath the matrix. Some specimen were partially destroyed, so the missing parts were reconstructed on computer screen in order to get estimations of the brain volume and endocranial morphology, both major fields of interest in physical anthropology. Moreover the computerized form of the data allows new descriptions of morphologic structures by the means of 'geometric morphometrics'. Some of the results may change aspects and interpretations in human evolution. The introduction of new imaging and post processing techniques created a new field of research: Virtual Anthropology. PMID:10565508

Recheis, W; Weber, G W; Schäfer, K; Knapp, R; Seidler, H; zur Nedden, D

1999-08-01

427

Time to Split, Virtually: Expanding Virtual Publics into Vibrant Virtual Metropolises  

Microsoft Academic Search

This paper assesses some of the strong claims made about the significance of virtual communities to electronic commerce. It focuses on the notion of community building as a means to constructing virtual metropolises, where tens of thousands of individuals are engaged in public computer-mediated discourse. It is argued that the community approach discourages systemic analysis of collaborative media systems. In

Quentin Jones

2000-01-01

428

What is an Atomic Force Microscope? The Lego Scanning Force Microscope (LSPM) is a model of an Atomic Force Microscope (AFM), a very  

E-print Network

5/28/2008 What is an Atomic Force Microscope? The Lego Scanning Force Microscope (LSPM) is a model of an Atomic Force Microscope (AFM), a very high resolution type of Scanning Probe Microscope the surface through touch. The atomic force microscope can be used to image and manipulate atoms

429

Petrology of the Devonian gas-bearing shale along Lake Erie helps explain gas shows  

SciTech Connect

Comprehensive petrologic study of 136 thin sections of the Ohio Shale along Lake Erie, when combined with detailed stratigraphic study, helps explain the occurrence of its gas shows, most of which occur in the silty, greenish-gray, organic poor Chagrin Shale and Three Lick Bed. Both have thicker siltstone laminae and more siltstone beds than other members of the Ohio Shale and both units also contain more clayshales. The source of the gas in the Chagrin Shale and Three Lick Bed of the Ohio Shale is believed to be the bituminous-rich shales of the middle and lower parts of the underlying Huron Member of the Ohio Shale. Eleven petrographic types were recognized and extended descriptions are provided of the major ones - claystones, clayshales, mudshales, and bituminous shales plus laminated and unlaminated siltstones and very minor marlstones and sandstones. In addition three major types of lamination were identified and studied. Thirty-two shale samples were analyzed for organic carbon, whole rock hydrogen and whole rock nitrogen with a Perkin-Elmer 240 Elemental Analyzer and provided the data base for source rock evaluation of the Ohio Shale.

Broadhead, R.F.; Potter, P.E.

1980-11-01

430

The Plumbing System of Vulcano Island (Italy) as Revealed by Fluid Inclusion Geobarometry, Petrology, and Geophysics  

NASA Astrophysics Data System (ADS)

We present a model of the plumbing system of the active Vulcano Island (Southern Tyrrhenian sea), by merging petrological, geophysical and fluid inclusion data. The structure of the magma storage system consists of two major deep accumulation zones located at 17-21 km and 8-13 km depth in the crust, plus a minor one lying at 5-1 km depth beneath the Fossa Cone. These three zones correspond to interfaces between different layers of the continental crust. The deepest magma accumulation zone contains mafic melts, and is located at the granulitic lower crust/mantle boundary. Mafic magmas, undergoing continuous mixing with primary melts from the mantle, either differentiate in the middle crust accumulation zone (13-8 km), or upraise to the surface. Entering of these magmas into the shallowest reservoir, located at 5-1 km depths, occurs shortly before magma outbreak at the surface, and may represent the trigger of either basaltic (VEI < 2) or rhyolitic (VEI up to 3) eruptions. Changes in the geochemical and geophysical parameters observed in the last century may not be related to the dynamics of the shallowest magma reservoir, but could be due to the activation of tectonic structures. The proposed model provides a new basis for strategies of volcano monitoring, and for eruption forecasting.

Frezzotti, M.; Peccerillo, A.; de Astis, G.; Ventura, G.

2006-12-01

431

Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia  

USGS Publications Warehouse

Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1??wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential.

Belkin, H.E.; Tewalt, S.J.; Hower, J.C.; Stucker, J.D.; O'Keefe, J. M. K.

2009-01-01

432

CM chondrites exhibit the complete petrologic range from type 2 to 1  

NASA Astrophysics Data System (ADS)

Recognition and characterization of the different CM lithologies as components in all meteorites could reveal details of the nature and chronology of alteration and brecciation events on hydrous asteroids. The CM chondrites are of particular interest, as they are the most common carbonaceous chondrites and are found as clasts within other types of meteorites, which suggests that the CM parent asteroids are (or were) widespread in the sections of the asteroid belt providing samples to Earth. Some CM2s, including EET 90047, ALH 83100, and Y 82042, are more 'extensively' altered, and are distinguished by a high proportion of Mg-rich phyllosilicates and Ca-Mg carbonates, frequently in rounded aggregates, and near absence of olivine or pyroxene. 'Completely' altered CMs, called CM1s, essentially lack olivine or pyroxene; these include EET 83334, ALH 88045, and the CM1 clasts in Kaidun. Cold Bokkeveld and EET 84034, both highly brecciated CMs, consist of both extensively and completely altered lithologies. We describe how these lithologies further cosntrain physicochemical conditions on hydrous asteroids. We conclude that CM chondrites exhibit the petrologic range 2 through 1, and that progressive alteration on the parent hydrous asteroid(s) was accompanied by significant increases in temperature (to a peak of approximately 450 C), fO2, water-rock ratio, and (locally) degree of chemical leaching, all well beyond the conditions recorded by CM2s.

Zolensky, M. E.; Browning, L. B.

1994-07-01

433

CM chondrites exhibit the complete petrologic range from type 2 to 1. [Abstract only  

NASA Technical Reports Server (NTRS)

Recognition and characterization of the different CM lithologies as components in all meteorites could reveal details of the nature and chronology of alteration and brecciation events on hydrous asteroids. The CM chondrites are of particular interest, as they are the most common carbonaceous chondrites and are found as clasts within other types of meteorites, which suggests that the CM parent asteroids are (or were) widespread in the sections of the asteroid belt providing samples to Earth. Some CM2s, including EET 90047, ALH 83100, and Y 82042, are more 'extensively' altered, and are distinguished by a high proportion of Mg-rich phyllosilicates and Ca-Mg carbonates, frequently in rounded aggregates, and near absence of olivine or pyroxene. 'Completely' altered CMs, called CM1s, essentially lack olivine or pyroxene; these include EET 83334, ALH 88045, and the CM1 clasts in Kaidun. Cold Bokkeveld and EET 84034, both highly brecciated CMs, consist of both extensively and completely altered lithologies. We describe how these lithologies further cosntrain physicochemical conditions on hydrous asteroids. We conclude that CM chondrites exhibit the petrologic range 2 through 1, and that progressive alteration on the parent hydrous asteroid(s) was accompanied by significant increases in temperature (to a peak of approximately 450 C), fO2, water-rock ratio, and (locally) degree of chemical leaching, all well beyond the conditions recorded by CM2s.

Zolensky, M. E.; Browning, L. B.

1994-01-01

434

Raman microspectroscopy: a powerful analytic and imaging tool in petrology and geochemistry  

NASA Astrophysics Data System (ADS)

Raman microspectroscopy is a vibrational spectroscopy based on the inelastic scattering of light interacting with molecules. This technique has benefited from recent developments in spectral and spatial resolution as well as sensitivity which make it widely used in Geosciences. A very attractive aspect of Raman spectroscopy is that it does not require any complex sample preparation. In addition, Raman imaging is now a routine and reliable technique which makes it competitive with SEM-EDS mapping for mineral mapping for instance. Raman microspectroscopy is a complementary technique to SEM, EMP, SIMS... as it can provide not only information on mineral chemistry, but overall on mineral structure. Raman Microspectroscopy is for instance the best in situ technique to distinguish mineral polymorphs. In addition the sensitivity of RM to mineral structure is extremely useful to study accessory minerals like oxides or sulphides as well as graphitic carbons. A brief presentation of the analytical capabilities of modern Raman spectroscopy will be presented. Then recent applications of RM in petrological and geochemical problems will be reviewed, including Raman imaging. The advantages and disadvantages of this technique compared to other micro-analytic tools will be discussed.

Beyssac, O.

2013-12-01

435

Petrologic-petrophysical-engineering relationships, selected wells near the Arctic National Wildlife Refuge, Alaska  

SciTech Connect

In the context of the reservoir management and resource assessment programs of the U.S. Bureau of Land Management in Alaska, selected stratigraphic horizons were studied in a number of wells adjacent to the Arctic National Wildlife Refuge (ANWR), northeast Alaska. Petrographic analyses were integrated with petrophysical and engineering data, in order to provide a substantive knowledge base from which to infer reservoir potentials elsewhere in the region, using geological and geophysical methods. Of particular interest in the latter regard is the ANWR area. Horizons of concern with regard to reservoir characteristics include Franklinian through Brookian strata. Of particular interest are clastic Ellesmerian 'Break-up/Rift Sequence' sediments such as the Lower Cretaceous Thomson sand, and deeper-water marine clastics, as exemplified by the Brookian Colville Group 'turbidites.' Also of concern are pre-Ellesmerian 'basement' rocks, some of which are hosts to hydrocarbon accumulations in the Point Thomson field. Petrologic-mineralogic characteristics have been keyed to various wireline log responses and related to available engineering data, as feasible, for the wells considered. Synthesis of this information in terms of the regional geological framework, tied in with geophysical data, will facilitate more refined, effective resource assessment and management.

Mowatt, T.C.; Gibson, C.; Seidlitz, A.; Bascle, R.; Dygas, J. (U.S. Bureau of Land Management, Anchorage, AK (United States))

1991-03-01

436

Petrology and diagenesis of Pennsylvanian Tradewater Group sandstones in the Illinois Basin, southwestern Indiana  

SciTech Connect

The Pennsylvanian Tradewater Group on the southeastern margin of the Illinois Basin was deposited on a tidally influenced coastal plain and estuary and contains a variety of lithologies ranging from quartzose sandstones to low-sulfur. Clayey sandstones associated with coals tend to be poorly sorted and contain microcrystalline siderite concretions, pyrite, muscovite, and abundant terrestrial organic material as lenses and scattered fragments. Tiny siderite rhombohedra that occur on the margins of grains in the organic-rich sandstones formed early in a reducing, alkaline (methanogenic ) environment. Early diagenetic precipitation of ankerite and calcite cement postdated the siderite. Quartz-rich sandstones are moderately well sorted and contain primarily authigenic rather than detrital clay. Under transmitted light, petrographic thin sections of quartzose sandstones showed numerous, apparent, long and concavo-convex contacts between detrital quartz grains. Cathodoluminescence, scanning electron microscopy, and polished-thin-section study revealed, however, that the contacts are actually between quartz overgrowths. Most plagioclase and potassium feldspars show only minor dissolution; however, some plagioclase is albitized or has small overgrowths. Large areas of nonferroan carbonate cement remnants in optical continuity indicate that there was widespread dissolution during later (meteoric ) diagenesis. In the future, petrologic analyses will be combined with sedimentologic studies so that diagenesis can be correlated with depositional environment, and this research will be continued on deeper cores in the central part of the Illinois Basin.

Hansley, P.L. (Geological Survey, Denver, CO (United States). Denver Federal Center)

1992-01-01

437

The petrology of meteoritic chrondrules: Evidence for fluctuation conditions in the solar nebula  

SciTech Connect

A detailed petrologic study of magnesian chondrules in CM2, CR2, CO3, CV3, and UOC (LL3,L3,H3) primitive chondrites has been made to establish how chondrules formed and evolved in the solar nebula. The compositions of mineral constituents associated with magnesian chondrules have been used to calculate the redox conditions of the zones in the solar nebular where these chondrules formed. The compositions of these mineral constituents are evidence for non-solar compositions, particularly non-solar O/H and O/C, in the nebula. The data suggest that these element ratios fluctuated with space and/or time in the zones where C3 and UOC chondrules formed. Furthermore, it appears that UOC chondrules, in general, formed in a zone with greater OH than that in the zone where C3 chondrules formed; and C3 chondrules formed in a zone with greater O/H than that where C2 chondrules formed. Non-solar redox conditions in the solar nebula have been attributed to processes that concentrate dust relative to gas. When concentrations of dust, which consists of oxides, are heated and vaporized, non-solar oxygen-rich gas is produced. The effects of the concentration, vaporization, and recondensation of dust in the nebula on oxygen isotopic systematics have been modelled. It is proposed that chondrules formed by the melting of this mass-fractionated dust, whose isotopic composition was retained by the chondrules.

Kring, D.A.

1989-01-01

438

Geologic map of Harrat Hutaymah, with petrologic classification and distribution of ultramafic inclusions, Saudi Arabia  

USGS Publications Warehouse

This map shows detailed geology of the Quaternary and Tertiary volcanic deposits that comprise Harrat Hutaymah and an updated and generalized compilation of the underlying Proterozoic and Paleozoic basement rocks. Quaternary alluvial cover and details of basement geology (that is, faults, dikes, and other features) are not shown. Volcanic unit descriptions and contact relations are based upon field investigation by the author and on compilation and revision of mapping Kellogg (1984; northern half of area) and Pallister (1984; southern half of area). A single K-Ar date of 1.80 ± 0.05 Ma for an alkali olivine basalt flow transected by the Al Hutaymah tuff ring (Pallister, 1984) provides the basis for an estimated late Tertiary to Quaternary age range for all harrat volcanic units other than unit Qtr (tuff reworked during Quaternary age time). Contact relations and unit descriptions for the basement rocks were compiled from Pallister (1984), Kellogg (1984 and 1985), DuBray (1984), Johnson and Williams (1984), Vaslet and others (1987), Cole and Hedge (1986), and Richter and others (1984). All rock unit names in this report are informal and capitalization follows Saudi Arabian stratigraphic nomenclature (Fitch, 1980). Geographic information was compiled from Pallister (1984), Kellogg (1984), and Fuller (in Johnson and Williams, 1984) and from field investigation by the author in 1986. The pie diagrams on the map show the distribution and petrology of ultramafic xenoliths of Harrat Hutaymah. The pie diagrams are explained by a detailed classification of ultramafic xenoliths that is introduced in this report.

Thornber, Carl R.

1990-01-01

439

Geochemical and petrological control on the reservoir quality of the unconventional petroleum systems in western Canada  

NASA Astrophysics Data System (ADS)

The commercial exploitation of the unconventional hydrocarbon resources in Canada has revolutionized the hydrocarbon supply picture. Canadian sedimentary basins hold great potential for unconventional gas and liquid hydrocarbon. There is a prolific production of the unconventional liquid and gas hydrocarbon from the lower Triassic and Jurassic formations in the Western Canadian Sedimentary Basin, while major Ordovician play in Eastern Canada has shown great potential for future exploitation. The main challenge in characterizing the unconventional reservoirs is that the traditional analytical approaches are poorly defined and calibrated for these resources. Characterizing the unconventional plays demand unconventional methodology, which takes into account various aspects of the combined source rock and reservoir system. This involves a complex understanding of the precursor organic matter in source rock, hydrocarbon generation and migration, thermal maturity, interaction between mineral matter and various organic matter phases in the rock, and the complex role of diagenesis in the reservoir quality and behaviour. This study relies on integrated inorganic and organic geochemistry, along with an innovative organic petrology approach to investigate micro variations in the compositions and the reservoir quality of the rocks throughout the cores obtained from the recent unconventional liquid and gas plays across Canada.

Sanei, Hamed

2014-05-01

440

Petrology and geochemistry of Alto Peak, a vapor-cored hydrothermal system, Leyte Province, Philippines  

SciTech Connect

Based on detailed petrological information on secondary mineral assemblages and the composition of fluids trapped in inclusions and discharged from five wells, the Alto Peak geothermal field was found to represent a combined vapor and liquid-dominated system. A central core or chimney, with a diameter of about 1 km, a height of some 3 km and occupied by a high gas vapor (1.1 to 5.6 molal CO{sub 2}), is surrounded by an envelope of intermediate salinity water (7,000 mg/kg Cl) with temperatures between 250 and 350 C. The transition from purely vapor-dominated to liquid-dominated zones takes place via two-phase zones occupied by fluid mixtures of highly variable compositions. Much of the lower temperature, mature neutral pH Cl water is likely to have formed during an earlier stage in the evolution of the system. High temperatures of > 300 C, and associated alteration, are limited to wells AP-1D and the lower parts of AP-2D and are ascribed to re-heating by recent magmatic intrusions. The isotopic composition of the well discharges suggests that they contain some 40 to 50% of magmatic water. Alto Peak is considered a typical example of hydrothermal systems associated with many dormant volcanoes.

Reyes, A.G. [Philippine National Oil Co.-Energy Development Corp., Fort Bonifacio (Philippines). Geothermal Div.] [Philippine National Oil Co.-Energy Development Corp., Fort Bonifacio (Philippines). Geothermal Div.; [Inst. of Geological and Nuclear Sciences, Lower Hutt (New Zealand); Giggenbach, W.F. [Inst. of Geological and Nuclear Sciences, Lower Hutt (New Zealand)] [Inst. of Geological and Nuclear Sciences, Lower Hutt (New Zealand); Saleras, J.R.M.; Salonga, N.D.; Vergara, M.C. [Philippine National Oil Co.-Energy Development Corp., Fort Bonifacio (Philippines). Geothermal Div.] [Philippine National Oil Co.-Energy Development Corp., Fort Bonifacio (Philippines). Geothermal Div.

1993-10-01

441

Scanning X-ray microscope  

US Patent & Trademark Office Database

A scanning X-ray microscope including an X-ray source capable of emitting a beam of X-rays, a collimator positioned to receive the beam of X-rays and, to collimate this beam, a focusing cone means to focus the beam of X-rays, directed by the collimator, onto a focal plane, a specimen mount for supporting a specimen in the focal plane to receive the focused beam of X-rays, and X-ray beam scanning means to relatively move the specimen and the focusing cone means and collimator to scan the focused X-ray beam across the specimen, a detector disposed adjacent the specimen to detect flourescent photons emitted by the specimen upon exposure to the focused beam of X-rays to provide an electrical output representative of this detection, means for displaying and/or recording the information provided by the output from the detector, means for providing information to the recording and/or display means representative of the scan rate and position of the focused X-ray beam relative to the specimen whereby the recording and/or display means can correlate the information received to record and/or display quantitive and distributive information as to the quantity and distribution of elements detected in the specimen. Preferably there is provided an X-ray beam modulation means upstream, relative to the direction of emission of the X-ray beam, of the focusing cone means.

1982-02-23

442

Print your atomic force microscope  

NASA Astrophysics Data System (ADS)

Progress in scanning probe microscopy profited from a flourishing multitude of new instrument designs, which lead to novel imaging modes and as a consequence to innovative microscopes. Often these designs were hampered by the restrictions, which conventional milling techniques impose. Modern rapid prototyping techniques, where layer by layer is added to the growing piece either by light driven polymerization or by three-dimensional printing techniques, overcome this constraint, allowing highly concave or even embedded and entangled structures. We have employed such a technique to manufacture an atomic force microscopy (AFM) head, and we compared its performance with a copy milled from aluminum. We tested both AFM heads for single molecule force spectroscopy applications and found little to no difference in the signal-to-noise ratio as well as in the thermal drift. The lower E modulus seems to be compensated by higher damping making this material well suited for low noise and low drift applications. Printing an AFM thus offers unparalleled freedom in the design and the rapid production of application-tailored custom instruments.

Kühner, Ferdinand; Lugmaier, Robert A.; Mihatsch, Steffen; Gaub, Hermann E.

2007-07-01

443

Scanning Microscopes Using X Rays and Microchannels  

NASA Technical Reports Server (NTRS)

Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, 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 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the image sensor consists predominantly of radiation that was launched along the longitudinal direction of the microchannels. Therefore, most of the radiation arriving at each pixel on the sensor must have traveled along a straight line from a corresponding location on the specimen. Thus, there is a one-to-one mapping from a point on a specimen to a pixel in the image sensor, so that the output of the image sensor contains image information equivalent to that from a microscope.

Wang, Yu

2003-01-01

444

Visualization and holography: real virtuality  

NASA Astrophysics Data System (ADS)

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 thinking. A holography gives us possibility to percept the visual shapes as the virtual object in a form of a real 3D copy, i.e. hologram. We propose to add a light field surrounding the virtual object in description of its computer model. The object is determined as the set of points emit the coherent light. A scheme of direct calculation and printing the digital hologram of the virtual object is also taken into consideration. The result of realization of the scheme for the virtual shape and for the real object is indistinguishable on the stage of reconstruction. This brings us to the concept of the Real Virtuality.

Matveyev, Sergey V.; Klimenko, Stanislav

2002-03-01

445

Diagnosis of major cancer resection specimens with virtual slides: impact of a novel digital pathology workstation.  

PubMed

Digital pathology promises a number of benefits in efficiency in surgical pathology, yet the longer time required to review a virtual slide than a glass slide currently represents a significant barrier to the routine use of digital pathology. We aimed to create a novel workstation that enables pathologists to view a case as quickly as on the conventional microscope. The Leeds Virtual Microscope (LVM) was evaluated using a mixed factorial experimental design. Twelve consultant pathologists took part, each viewing one long cancer case (12-25 slides) on the LVM and one on a conventional microscope. Total time taken and diagnostic confidence were similar for the microscope and LVM, as was the mean slide viewing time. On the LVM, participants spent a significantly greater proportion of the total task time viewing slides and revisited slides more often. The unique design of the LVM, enabling real-time rendering of virtual slides while providing users with a quick and intuitive way to navigate within and between slides, makes use of digital pathology in routine practice a realistic possibility. With further practice with the system, diagnostic efficiency on the LVM is likely to increase yet more. PMID:25128229

Randell, Rebecca; Ruddle, Roy A; Thomas, Rhys G; Mello-Thoms, Claudia; Treanor, Darren

2014-10-01

446

Virtual Memory Replacement Using Historical Information on Virtual Objects.  

National Technical Information Service (NTIS)

The paper describes a measurement technique that is used to monitor memory usage. It then proposes a new virtual memory replacement algorithm that is partially based on periodic, sequential, and transient behaviors. It also describes an approximation to L...

R. B. Hagmann

1991-01-01

447

A microscopic simulator for urban traffic systems  

Microsoft Academic Search

Based on microscopic traffic models, the object-oriented method and visualization technology are applied to the microscopic simulation of urban traffic systems, and a concise and flexible traffic simulator is developed. For an urban traffic network with 3 by 3 intersections, simulation results show that the vehicle behaviors in the traffic network accord with human traffic experience, and the movement curves

Lin Yong; Cai Yuan Li

2002-01-01

448

Modeling Microscopic Chemical Sensors in Capillaries  

Microsoft Academic Search

Nanotechnology-based microscopic robots could provide accurate in vivo measurement of chemicals in the bloodstream for detailed biological research and as an aid to medical treatment. Quantitative perfor- mance estimates of such devices require models of how chemicals in the blood diffuse to the devices. This paper models microscopic robots and red blood cells (erythrocytes) in capillaries using realistic distorted cell

Tad Hogg

2008-01-01

449

Biological imaging with a neutron microscope  

Microsoft Academic Search

Two neutron microscope imaging experiments were performed at the Center for Neutron Research, at the National Institute for Standards and Technology (NIST) on the NG-7 30-Meter Small Angle Neutron Scattering Instrument. The NIST neutron source wavelength could be varied from 5 Å to 20 Å, and the neutron bandwidth could be varied. For both microscope experiments the image resolution was

Jay T. Cremer; Melvin A. Piestrup; Charles K. Gary; Richard H. Pantell

2004-01-01

450

Robotic CCD microscope for enhanced crystal recognition  

DOEpatents

A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

Segelke, Brent W. (San Ramon, CA); Toppani, Dominique (Livermore, CA)

2007-11-06

451

Getting the Most out of the Microscope  

ERIC Educational Resources Information Center

Discusses some of the misconceptions that students and instructors have regarding the microscope and provides stepwise instructions to enable the biology student to acquire a sound scientific technique for setting up and using the light microscope with minimal expenditure of time and effort. (JR)

Price, Fred W.

1973-01-01

452

Angled Tip for a Scanning Force Microscope.  

National Technical Information Service (NTIS)

A microscope probe includes a cantilever having a carbon nanostructure attached thereto at a distally oriented angle. A method of making the microscope probe can include the steps of: providing a cantilever; depositing a masking layer on a surface of the ...

H. Cui

2004-01-01

453

Information Virtulization in Virtual Environments  

NASA Technical Reports Server (NTRS)

Virtual Environments provide a natural setting for a wide range of information visualization applications, particularly wlieit the information to be visualized is defined on a three-dimensional domain (Bryson, 1996). This chapter provides an overview of the issues that arise when designing and implementing an information visualization application in a virtual environment. Many design issues that arise, such as, e.g., issues of display, user tracking are common to any application of virtual environments. In this chapter we focus on those issues that are special to information visualization applications, as issues of wider concern are addressed elsewhere in this book.

Bryson, Steve; Kwak, Dochan (Technical Monitor)

2001-01-01

454

Integrating virtual worlds & virtual learning environments for online education  

Microsoft Academic Search

In recent years there has been significant growth in the use of 3D virtual worlds for e-learning and distance education. These immersive environments offer the ability to create complex, highly interactive simulations using in-world modeling and scripting tools. Virtual learning environments' support teaching and learning in an educational context, offering the functionality to manage the presentation, administration and assessment of

M. J. Callaghan; K. McCusker; J. Lopez Losada; J. G. Harkin; S. Wilson

2009-01-01

455

Imaging Schwarzschild multilayer X-ray microscope  

NASA Technical Reports Server (NTRS)

We have designed, analyzed, fabricated, and tested Schwarzschild multilayer X-ray microscopes. These instruments use flow-polished Zerodur mirror substrates which have been coated with multilayers optimized for maximum reflectivity at normal incidence at 135 A. They are being developed as prototypes for the Water Window Imaging X-Ray Microscope. Ultrasmooth mirror sets of hemlite grade sapphire have been fabricated and they are now being coated with multilayers to reflect soft X-rays at 38 A, within the biologically important 'water window'. In this paper, we discuss the fabrication of the microscope optics and structural components as well as the mounting of the optics and assembly of the microscopes. We also describe the optical alignment, interferometric and visible light testing of the microscopes, present interferometrically measured performance data, and provide the first results of optical imaging tests.

Hoover, Richard B.; Baker, Phillip C.; Shealy, David L.; Core, David B.; Walker, Arthur B. C., Jr.; Barbee, Troy W., Jr.; Kerstetter, Ted

1993-01-01

456

A microscopic view on acoustomigration.  

PubMed

Stress-induced material transport in surface acoustic wave devices, so-called acoustomigration, is a prominent failure mechanism, especially in high-power applications. We used scanning probe microscopy techniques to study acoustomigration of metal structures in-situ, i.e., during the high-power loading of the device. Scanning acoustic force microscopy (SAFM) allows for the simultaneous measurement of the acoustic wavefield and the topography with submicron lateral resolution. High-resolution microscopy is essential as acoustomigration is a phenomenon that not only results in the formation of more macroscopic voids and hillocks but also affects the microscopic grain structure of the film. We present acoustic wavefield and topographic image sequences giving a clear insight into the nature of the film damage on a submicron scale. The 900 MHz test structures were fabricated on 36 degrees YX-lithium tantalate (YX-LiTaO3) and incorporated 420-nm thick aluminium (Al) electrodes. By correlating the acoustic wavefield mapping and the local changes in topography, we confirmed model calculations that predict the correspondence of damage and stress (i.e., hillocks and voids) are preferentially formed in areas of high stress. The way the film is damaged does not significantly depend on the applied power (for typical power levels used in this study). Furthermore, acoustomigration leads to smoother surfaces via lateral grain growth. Another contribution to the grain dynamics comes from the apparent grain rotation in the highly anisotropic stress field of an acoustic wave. Thus, through in-situ scanning probe microscopy techniques, one can observe the initial changes of the grain structure in order to obtain a more detailed picture of the phenomenon of acoustomigration. PMID:16285457

Hesjedal, Thorsten; Mohanty, Jyoti; Kubat, Franz; Ruile, Werner; Reindl, Leonhard M

2005-09-01

457

Game-Based Virtual Worlds as Decentralized Virtual Activity Systems  

NASA Astrophysics Data System (ADS)

There is widespread interest in the development and use of decentralized systems and virtual world environments as possible new places for engaging in collaborative work activities. Similarly, there is widespread interest in stimulating new technological innovations that enable people to come together through social networking, file/media sharing, and networked multi-player computer game play. A decentralized virtual activity system (DVAS) is a networked computer supported work/play system whose elements and social activities can be both virtual and decentralized (Scacchi et al. 2008b). Massively multi-player online games (MMOGs) such as World of Warcraft and online virtual worlds such as Second Life are each popular examples of a DVAS. Furthermore, these systems are beginning to be used for research, deve-lopment, and education activities in different science, technology, and engineering domains (Bainbridge 2007, Bohannon et al. 2009; Rieber 2005; Scacchi and Adams 2007; Shaffer 2006), which are also of interest here. This chapter explores two case studies of DVASs developed at the University of California at Irvine that employ game-based virtual worlds to support collaborative work/play activities in different settings. The settings include those that model and simulate practical or imaginative physical worlds in different domains of science, technology, or engineering through alternative virtual worlds where players/workers engage in different kinds of quests or quest-like workflows (Jakobsson 2006).

Scacchi, Walt

458

Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers  

SciTech Connect

Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.

Doak, R. B.; DePonte, D. P.; Nelson, G.; Camacho-Alanis, F.; Ros, A.; Spence, J. C. H.; Weierstall, U. [Arizona State University, Tempe, AZ 85287-1504 (United States); Centre for Free-Electron Laser Science, DESY, D-22607 Hamburg (Germany); Arizona State University, Tempe, AZ 85287-1504 (United States)

2012-11-27

459

Virtual acoustic prototyping  

NASA Astrophysics Data System (ADS)

In this paper the re-creation of 3-D sound fields so the full psycho-acoustic impact of sound sources can be assessed before the manufacture of a product or environment is examined. Using head related transfer functions (HRTFs) coupled with a head tracked set of headphones the sound field at the left and right ears of a listener can be re-created for a set of sound sources. However, the HRTFs require that sources have a defined location and this is not the typical output from numerical codes which describe the sound field as a set of distributed modes. In this paper a method of creating a set of equivalent sources is described such that the standard set of HRTFs can be applied in real time. A structural-acoustic model of a cylinder driving an enclosed acoustic field will be used as an example. It will be shown that equivalent sources can be used to recreate all of the reverberation of the enclosed space. An efficient singular value decomposition technique allows the large number of sources required to be simulated in real time. An introduction to the requirements necessary for 3-D virtual prototyping using high frequency Statistical Energy Analysis models will be presented. [Work supported by AuSim and NASA.

Johnson, Marty

2003-10-01

460

Building a virtual planet  

NASA Technical Reports Server (NTRS)

The virtual Planetary Laboratory (VPL) is a recently funded 5-yr project, which seeks toimprove our understanding of the range of plausible environments and the likely signatures for life on extrasolar terrestrial planets. To achieve these goals we are developing a suite of innovative modeling tools to simulate the environments and spectra of extrasolar planets. The core of the VPL IS a coupled radiative transfer/climate/chemistry model, which is augmented by interchangeable modules which characterize geological, exogenic, atmospheric escape, and life processes. The VPL is validated using data derived from terrestrial planets within our own solar system. The VPL will be used to explore the plausible range of atmospheric composittions and globally averaged spectra for extrasolar planets and for early Earth, and will improve our understanding of the effect of life on a planet's atmospheric spectrum and composition. The models will also be used to create a comprehensive spectral catalog to provide recommendations on the optimum wavelength range, spectral resolution, and instrument sensitivity required to characterize extrasolar terrestrial planets. Although developed by our team, the VPL is envisioned to be a comprehensive and flexible tool, which can be collaboratively used by the broader planetary science and astrobiology communities. This presentation will describe the project concept, the tasks involved, and will outline current progress to date. This work is funded by the NASA Astrobiology Institute.

Meadows, V. S.

2002-01-01

461

Virtual art revisited  

NASA Astrophysics Data System (ADS)

Virtual reality art at the turn of the millenium saw an explosion of creative exploration around this nascent technoloy. Though VR art has much in common with media art in general, the affordances of the technology gave rise to unique experiences, discourses, and artistic investigations. Women artists were at the forefront of the medium, shaping its aesthetic and technical development, and VR fostered a range of artistic concerns and experimentation that was largely distinct from closely related forms such as digital games. Today, a new wave of consumer technologies including 3D TV's, gestural and motion tracking interfaces, and headmount displays as viable, low-cost gaming peripherals drives a resurgence in interest in VR for interactive art and entertainment. Designers, game developers, and artists working with these technologies are in many cases discovering them anew. This paper explores ways of reconnecting this current moment in VR with its past. Can the artistic investigations begun in previous waves of VR be continued? How do the similarities and differences in contexts, communities, technologies, and discourses affect the development of the medium?

Ruzanka, S.

2014-02-01

462

Toward the virtual classroom  

SciTech Connect

The Lawrence Livermore National Laboratory (LLNL) encourages its employees to remotely attend classes given by Stanford University, University of California at Davis, and the National Technological University (NTU). To improve the quality of education for LLNL employees, we are cooperating with Stanford University in upgrading the Stanford Instructional Television Network (SITN). A dedicated high-speed communication link (Tl) between Stanford and LLNL will be used for enhanced services such as videoconferencing, real time classnotes distribution, and electronic distribution of homework assignments. The new network will also allow students to take classes from their offices with the ability to ask the professor questions via an automatically dialed telephone call. As part of this upgrade, we have also proposed a new videoconferencing based classroom environment where students taking remote classes would feel as though they are attending the live class. All paperwork would be available in near real time and students may converse normally with, and see, other remote students as though they were all in the same physical location. We call this the Virtual Classroom.'' 1 ref., 6 figs.

Pihlman, M.; Dirks, D.H.

1990-01-03

463

Virtual environment tactile system  

DOEpatents

A method for providing a realistic sense of touch in virtual reality by means of programmable actuator assemblies is disclosed. Each tactile actuator assembly consists of a number of individual actuators whose movement is controlled by a computer and associated drive electronics. When an actuator is energized, the rare earth magnet and the associated contactor, incorporated within the actuator, are set in motion by the opposing electromagnetic field of a surrounding coil. The magnet pushes the contactor forward to contact the skin resulting in the sensation of touch. When the electromagnetic field is turned off, the rare ea