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1

Editor's Note: Geology Is Fundamental (December 2006)  

NSDL National Science Digital Library

Geology is fundamental. The usual triad of sciences (chemistry, physics, and biology) is also clearly important. Not much can be explained without physics, for example. But geology, the history of Earth, is an application of these sciences that deserves more attention. It can be immediately seen around us whether we live in Arizona or Iowa. This issue presents lessons that will introduce Earth science concepts to your students and make them applicable in your classroom.

Chris Ohana

2006-12-01

2

Field Geology/Processes  

NASA Technical Reports Server (NTRS)

The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

1996-01-01

3

Geology and image processing  

NASA Technical Reports Server (NTRS)

Digital image processing for geological applications will be integrated with geographic information systems and data base management systems. While multiband data sets from radar and multispectral scanners will make extreme demands on memory, bus and processor architectures, it is expected that array processors and VLSI/VHSIC dedicated function chips will allow the use of fast Fourier transform and classification algorithms. It is anticipted that, as processor power increases, the weakest link of a processing system will become the analyst who uses it. Human engineering of systems is therefore recommended for the most effective utilization of remotely sensed geologic data.

Daily, M.

1982-01-01

4

Planetary geological processes  

NASA Astrophysics Data System (ADS)

In this introduction to planetary geology, we review the major geologic processes affecting the solid bodies of the solar system, namely volcanism, tectonism, impact cratering, and erosion. We illustrate the interplay of these processes in different worlds, briefly reviewing how they affect the surfaces of the Earth's Moon, Mercury, Venus and Mars, then focusing on two very different worlds: Jupiter's moon Io, the most volcanically active object in the solar system, and Saturn's moon Titan, where the interaction between a dense atmosphere and the surface make for remarkably earth-like landscapes despite the great differences in surface temperature and composition.

Lopes, Rosaly M. C.; Solomonidou, Anezina

2014-11-01

5

Oceanography - Marine Geological Processes  

NSDL National Science Digital Library

A first year course in oceanography with extensive Internet resources. Topics covered include: principles of thermodynamics, heat and mass transfer, fluid mechanics, continuum mechanics, and time-series analysis applied to marine geological and geophysical data; applications to transport of marine sediments; Pleistocene sedimentation and global climate change; and the thermal balance of the oceanic lithosphere. The link to the lecture schedule provides detailed supporting materials.

Russell McDuff

6

Coastal Geological Processes  

NSDL National Science Digital Library

Coastlines are places of continuous, often dramatic geological activity. They change daily and seasonally, but especially over long time periods. This interactive feature discusses the forces that help shape coastal landforms like cliffs and beaches. Topics include waves, tides, and currents; weathering, erosion, and deposition; and other factors, such as the activity of organisms and human modifications. A background essay and discussion questions are included.

7

Processes of Geology  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

Released 16 July 2003

This THEMIS visible image captures a complex process of deposition, burial and exhumation. The crater ejecta in the top of the image is in the form of flow lobes, indicating that the crater was formed in volatile-rich terrain. While a radial pattern can be seen in the ejecta, the pattern is sharper in the lower half of the ejecta. This is because the top half of the ejecta is still buried by a thin layer of sediment. It is most likely that at one time the entire area was covered. Wind, and perhaps water erosion have started to remove this layer, once again exposing the what was present underneath.

Image information: VIS instrument. Latitude -34.3, Longitude 181.2 East (178.8 West). 19 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2003-01-01

8

Review of image processing fundamentals  

NASA Technical Reports Server (NTRS)

Image processing through convolution, transform coding, spatial frequency alterations, sampling, and interpolation are considered. It is postulated that convolution in one domain (real or frequency) is equivalent to multiplication in the other (frequency or real), and that the relative amplitudes of the Fourier components must be retained to reproduce any waveshape. It is suggested that all digital systems may be considered equivalent, with a frequency content approximately at the Nyquist limit, and with a Gaussian frequency response. An optimized cubic version of the interpolation continuum image is derived as a set of cubic spines. Pixel replication has been employed to enlarge the visable area of digital samples, however, suitable elimination of the extraneous high frequencies involved in the visable edges, by defocusing, is necessary to allow the underlying object represented by the data values to be seen.

Billingsley, F. C.

1985-01-01

9

Planetary geology: Impact processes on asteroids  

NASA Technical Reports Server (NTRS)

The fundamental geological and geophysical properties of asteroids were studied by theoretical and simulation studies of their collisional evolution. Numerical simulations incorporating realistic physical models were developed to study the collisional evolution of hypothetical asteroid populations over the age of the solar system. Ideas and models are constrained by the observed distributions of sizes, shapes, and spin rates in the asteroid belt, by properties of Hirayama families, and by experimental studies of cratering and collisional phenomena. It is suggested that many asteroids are gravitationally-bound "rubble piles.' Those that rotate rapidly may have nonspherical quasi-equilibrium shapes, such as ellipsoids or binaries. Through comparison of models with astronomical data, physical properties of these asteroids (including bulk density) are determined, and physical processes that have operated in the solar system in primordial and subsequent epochs are studied.

Chapman, C. R.; Davis, D. R.; Greenberg, R.; Weidenschilling, S. J.

1982-01-01

10

Health benefits of geologic materials and geologic processes  

USGS Publications Warehouse

The reemerging field of Medical Geology is concerned with the impacts of geologic materials and geologic processes on animal and human health. Most medical geology research has been focused on health problems caused by excess or deficiency of trace elements, exposure to ambient dust, and on other geologically related health problems or health problems for which geoscience tools, techniques, or databases could be applied. Little, if any, attention has been focused on the beneficial health effects of rocks, minerals, and geologic processes. These beneficial effects may have been recognized as long as two million years ago and include emotional, mental, and physical health benefits. Some of the earliest known medicines were derived from rocks and minerals. For thousands of years various clays have been used as an antidote for poisons. "Terra sigillata," still in use today, may have been the first patented medicine. Many trace elements, rocks, and minerals are used today in a wide variety of pharmaceuticals and health care products. There is also a segment of society that believes in the curative and preventative properties of crystals (talismans and amulets). Metals and trace elements are being used in some of today's most sophisticated medical applications. Other recent examples of beneficial effects of geologic materials and processes include epidemiological studies in Japan that have identified a wide range of health problems (such as muscle and joint pain, hemorrhoids, burns, gout, etc.) that may be treated by one or more of nine chemically distinct types of hot springs, and a study in China indicating that residential coal combustion may be mobilizing sufficient iodine to prevent iodine deficiency disease. ?? 2006 MDPI. All rights reserved.

Finkelman, R.B.

2006-01-01

11

Comparison Charts of Geological Processes: Terrestrial Planets  

NSDL National Science Digital Library

This chart presents information on the geological processes (volcanism, impact cratering, tectonics, and gradation) that have affected the Earth, Moon, and the terrestrial planets. Students compare the effects these processes have had on the Moon and planets. There is also a blank chart and a sheet of notes on the geological processes that may be used in conjunction with this chart. This chart is one of the activities for the Exploring Planets in the Classroom's Introduction to the Solar System.

12

Migration of radionuclides in geologic media: Fundamental research needs  

SciTech Connect

An assessment of the fundamental research needs in understanding and predicting the migration of radionuclides in the subsurface is provided. Emphasis is on the following three technical areas: (1) aqueous speciation of radionuclides, (2) the interaction of radionuclides with substrates, and (3) intermediate-scale interaction studies. This research relates to important issues associated with environmental restoration and remediation of DOE sites contaminated with mixed radionuclide-organic wastes. 64 refs., 1 fig., 1 tab.

Reed, D.T. (Argonne National Lab., IL (USA)); Zachara, J.M.; Wildung, R.E. (Pacific Northwest Lab., Richland, WA (USA)); Wobber, F.J. (USDOE, Washington, DC (USA))

1990-01-01

13

Fundamental Processes in Plasmas. Final report  

SciTech Connect

This research focuses on fundamental processes in plasmas, and emphasizes problems for which precise experimental tests of theory can be obtained. Experiments are performed on non-neutral plasmas, utilizing three electron traps and one ion trap with a broad range of operating regimes and diagnostics. Theory is focused on fundamental plasma and fluid processes underlying collisional transport and fluid turbulence, using both analytic techniques and medium-scale numerical simulations. The simplicity of these systems allows a depth of understanding and a precision of comparison between theory and experiment which is rarely possible for neutral plasmas in complex geometry. The recent work has focused on three areas in basic plasma physics. First, experiments and theory have probed fundamental characteristics of plasma waves: from the low-amplitude thermal regime, to inviscid damping and fluid echoes, to cold fluid waves in cryogenic ion plasmas. Second, the wide-ranging effects of dissipative separatrices have been studied experimentally and theoretically, finding novel wave damping and coupling effects and important plasma transport effects. Finally, correlated systems have been investigated experimentally and theoretically: UCSD experients have now measured the Salpeter correlation enhancement, and theory work has characterized the 'guiding center atoms of antihydrogen created at CERN.

O'Neil, Thomas M.; Driscoll, C. Fred

2009-01-01

14

The solution of fundamental problems of geodynamics, geophysics, geology and planetology  

NASA Astrophysics Data System (ADS)

On the base of geodynamic model of the forced gravitational swing and displacement of shells of a planet under action of a gravitational attraction of surrounding (external) celestial bodies [1], [2] the fundamental problems of geodynamics, geology, planetology, geophysics, etc. have been studied and solved. 1). The mechanism of cyclic variations of activity of natural processes in various time scales. 2). The nature of eccentric positions of the core and the mantle of the Earth. A role of the Moon, the Sun, Neptune and other celestial bodies in activization of the swing of core-mantle system of the Earth. 3). Power of endogenous activity of planetary natural processes on planets and satellites. 4). The nature of correlations of natural processes with features of motion of baricenter of the solar system. 5). An explanation of influence of bodies of solar system on excitation of variations of planetary processes with Milankovitch's periods (in tens and hundred thousand years). 6). A possible explanation of geological cycles as result of excitation of solar system at its motion in a gravitational field of the Galaxy. 7). The phenomenon of polar inversion of natural processes on the Earth, both other planets and satellites. 8). Spasmodic (step-by-step) and catastrophic changes of activity of natural processes. 9). Sawtooth (gear curve) variations of natural processes. 10). The phenomenon of twisting of hemispheres (latitude zones) of celestial bodies. 11). Formation of the pear-shaped form of celestial bodies and the mechanism of its change. 10). Ordered planetary structures in spatial distribution of geological formations. 12). The phenomena of bipolarity of celestial bodies and antipodality of formations. Many fundamental problems of natural sciences have been obtained an explanation on the basis of developed geodynamic model (Barkin, 2002, 2009). The fundamental problems of celestial mechanics and geodynamics, geophysics and the geology, excited of scintific community in current of last decades and even centuries have been solved. The fundamental phenomena in rotation of the Earth: secular drift of a pole of its axis of rotation and non-tidal acceleration of axial rotation of a planet have received an explanation. Observable secular variations of a gravity, variations of a geopotential coefficients, secular drift of the center of mass of the Earth, secular changes of a global level of ocean and change of average levels of ocean in northern and southern hemispheres of the Earth, secular geodetic changes of the Earth in present period have been explained, etc. It is shown, that there is a uniform mechanism for many bodies of solar system of excitation of natural processes in their polar areas. In particular it is shown, that polar regions of many celestial bodies, including their soil layers, are sated by fluids. The last position obtains the precise confirmation in researches of subsoil waters and a water ice on Mars, the Moon, Mercury, etc. bodies of solar system. A wide number of the natural phenomena has been predicted by the author and these predictions have already obtained and obtain confirmations and an explanations in the data of modern observations and space missions. An existence of the seas in polar regions of the Titan, concentration of water ice in polar regions of Mercury, the Moon, Mars and other bodies of solar system has been predicted. The conclusion about fluid consentrations at polar regions of celestial bodies is extremely important for revealing of carbon deposits on the Earth, first of all in regions of Arctic and Antarctic. Work is partially supported by RFBR grants: N 08-02-00367, N-09-02-92113-JF. References 1. Barkin Yu.V. (2002) An explanation of endogenous activity of planets and satellites and its cyclisity. Isvestia sekcii nauk o Zemle Rossiiskoi akademii ectestvennykh nauk. Vyp. 9, M., VINITI, pp. 45-97. In Russian. 2. Barkin Yu.V. (2009) Moons and planets: mechanism of their life. Proceedings of International Conference 'Astronomy and World Heritage: across Time and Continents' (Kazan, 19-

Barkin, Yury

2010-05-01

15

Fundamental optical processes in armchair carbon nanotubes  

NASA Astrophysics Data System (ADS)

Single-wall carbon nanotubes provide ideal model one-dimensional (1-D) condensed matter systems in which to address fundamental questions in many-body physics, while, at the same time, they are leading candidates for building blocks in nanoscale optoelectronic circuits. Much attention has been recently paid to their optical properties, arising from 1-D excitons and phonons, which have been revealed via photoluminescence, Raman scattering, and ultrafast optical spectroscopy of semiconducting carbon nanotubes. On the other hand, dynamical properties of metallic nanotubes have been poorly explored, although they are expected to provide a novel setting for the study of electron-hole pairs in the presence of degenerate 1-D electrons. In particular, (n,n)-chirality, or armchair, metallic nanotubes are truly gapless with massless carriers, ideally suited for dynamical studies of Tomonaga-Luttinger liquids. Unfortunately, progress towards such studies has been slowed by the inherent problem of nanotube synthesis whereby both semiconducting and metallic nanotubes are produced. Here, we use post-synthesis separation methods based on density gradient ultracentrifugation and DNA-based ion-exchange chromatography to produce aqueous suspensions strongly enriched in armchair nanotubes. Through resonant Raman spectroscopy of the radial breathing mode phonons, we provide macroscopic and unambiguous evidence that density gradient ultracentrifugation can enrich ensemble samples in armchair nanotubes. Furthermore, using conventional, optical absorption spectroscopy in the near-infrared and visible range, we show that interband absorption in armchair nanotubes is strongly excitonic. Lastly, by examining the G-band mode in Raman spectra, we determine that observation of the broad, lower frequency (G-) feature is a result of resonance with non-armchair ``metallic'' nanotubes. These findings regarding the fundamental optical absorption and scattering processes in metallic carbon nanotubes lay the foundation for further spectroscopic studies to probe many-body physical phenomena in one dimension.

Hároz, Erik H.; Duque, Juan G.; Tu, Xiaomin; Zheng, Ming; Hight Walker, Angela R.; Hauge, Robert H.; Doorn, Stephen K.; Kono, Junichiro

2013-01-01

16

The activated sludge process: Fundamentals of operation  

Microsoft Academic Search

The procedures given here - based on extensive and intensive experience. Background information on process mechanics is followed by detailed consideration of control and troubleshooting practices. Contents: PREFACE AND INTRODUCTION; PROCESS MECHANICS; Basic Mechanism of Activated Sludge Systems; Formation of Activated Sludge; Growth of Microorganisms; Classifications of Microorganisms: Type, Environment, Age; Solids Separation and Return; FACTORS AFFECTING OPERATION; Raw Wastewater

R. Junkins; K. J. Deeny; T. H. Eckhoff

1983-01-01

17

The activated sludge process: Fundamentals of operation  

SciTech Connect

The procedures given here - based on extensive and intensive experience. Background information on process mechanics is followed by detailed consideration of control and troubleshooting practices. Contents: PREFACE AND INTRODUCTION; PROCESS MECHANICS; Basic Mechanism of Activated Sludge Systems; Formation of Activated Sludge; Growth of Microorganisms; Classifications of Microorganisms: Type, Environment, Age; Solids Separation and Return; FACTORS AFFECTING OPERATION; Raw Wastewater Strength; Dissolved Oxygen; pH; Temperature; Nutrients; Toxicity; Mixing; Detention Time; Hydraulics; PROCESS MODIFICATIONS; Conventional; Complete Mix; Contact-Stabilization; Extended Aeration; Others; PROCESS MONITORING; Visual; Analytical Indicators; OPERATIONAL CONTROL; Sludge Volume Index; Sludge Age; Mean Cell Residence Time; Food/Microorganism Ratio; Organic Loading Rate; Solids Loading Rate; Clarifier Overflow Rate; Weir Overflow Rate; Sludge Recycle Rate, Sludge Wastage Rate; Chemical Feed Rate; TROUBLESHOOTING; Low BOD Removal; Low D.O. in Aeration Baisn; Poor Settling; PLANT START-UP; Introduction; Pre Start-up Checkup; Wastewater Analysis; Seed Screening; Process Checklist; Mechanical Checklist; Familiarization and Training; Start-up; Seeding; Process Monitoring; Transition; Typical Start-up Problems; Foaming; Settling Problems; Low BOD Removal; INDEX.

Junkins, R.; Deeny, K.J.; Eckhoff, T.H.

1983-01-01

18

Plasma-Therm Workshop: Fundamentals of Plasma Processing (Etching & Deposition)  

E-print Network

Plasma-Therm Workshop: Fundamentals of Plasma Processing (Etching & Deposition) Nanofabrication The workshop will focus on the fundamentals of plasma etching and deposition. Lectures will include an introduction to vacuum technology, the basics of plasma and plasma reactors and an overview of mechanisms

Martin, Jan M.L.

19

Biological hydrogen production; fundamentals and limiting processes  

Microsoft Academic Search

Biological hydrogen production has been known for over a century and research directed at applying this process to a practical means of hydrogen fuel production has been carried out for over a quarter century. The various approaches that have been proposed and investigated are reviewed and critical limiting factors identified. The low energy content of solar irradiation dictates that photosynthetic

Patrick C. Hallenbeck; John R. Benemann

2002-01-01

20

Axioms and fundamental equations of image processing  

Microsoft Academic Search

Image-processing transforms must satisfy a list of formal requirements. We discuss these requirements and classify them into three categories: “architectural requirements” like locality, recursivity and causality in the scale space, “stability requirements” like the comparison principle and “morphological requirements”, which correspond to shape-preserving properties (rotation invariance, scale invariance, etc.). A complete classification is given of all image multiscale transforms satisfying

Luis Alvarez; Frédéric Guichard; Pierre-Louis Lions; Jean-Michel Morel

1993-01-01

21

Significant achievements in the Planetary Geology Program. [geologic processes, comparative planetology, and solar system evolution  

NASA Technical Reports Server (NTRS)

Developments reported at a meeting of principal investigators for NASA's planetology geology program are summarized. Topics covered include: constraints on solar system formation; asteriods, comets, and satellites; constraints on planetary interiors; volatiles and regoliths; instrument development techniques; planetary cartography; geological and geochemical constraints on planetary evolution; fluvial processes and channel formation; volcanic processes; Eolian processes; radar studies of planetary surfaces; cratering as a process, landform, and dating method; and the Tharsis region of Mars. Activities at a planetary geology field conference on Eolian processes are reported and techniques recommended for the presentation and analysis of crater size-frequency data are included.

Head, J. W. (editor)

1978-01-01

22

Fundamental concepts of digital image processing  

SciTech Connect

The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under observation rather than days later.

Twogood, R.E.

1983-03-01

23

Geologic Landforms and Processes on Icy Satellites  

NASA Technical Reports Server (NTRS)

During the first reconaissence of the satellites of the outer solar system conducted by the Voyager missions (1979-1989), a surprising diversity of unusual geologic landforms were observed, in some cases with bewildering complexity (e.g., Triton). Impact features were certainly expected but the variety of volcanic, diapiric, tectonic, impact, and erosional landforms was only remotely suggested by some early theoretical works. These diagnostic features are manifestations of the internal composition, thermal history, and dynamical evolution of these bodies. It is the job of the geologist to interpret the morphology, stratigraphy, and composition of these deposits and structures to ascertain what materials were mobilized in the interior, in what amount, and the mechanism and cause of their mobilization. In this chapter, we review what is know about these features and what constraints can be placed on composition and thermal history. Particular emphasis is placed on volcanic features, as these are most directly related to satellite composition and thermal history. The surface spectra, high albedos, and low bulk densities of the satellites of the outer solar system indicate that water and other ices are abundant on these bodies, particularly on their surfaces. Ices, particularly water ice, are less dense than silicates and will tend to float and form crusts during differentiation or partial melting of the interior. Ices therefore take the place of silicates as 'crust-forming' minerals and dominate geologic processes on icy satellites. Melted ices form magma bodies, and sometimes are extruded as lavas, an unusual but still valid perspective for terrestrial geologists. The unusual properties of some ices, including their low melting temperatures, and low strengths (as well as the decrease in density on the freezing of water ice), will ultimately be very important in interpreting this record.

Schenk, Paul M.; Moore, Jeffrey M.

1998-01-01

24

Fundamental kinetic modeling of the catalytic reforming process  

E-print Network

In this work, a fundamental kinetic model for the catalytic reforming process has been developed. The complex network of elementary steps and molecular reactions occurring in catalytic reforming has been generated through a computer algorithm...

Sotelo-Boyas, Rogelio

2007-04-25

25

Geologic processes on Venus: An update  

NASA Technical Reports Server (NTRS)

Studies of Venera 15 and 16 radar image and altimetry data and reevaluation of Pioneer Venus and earlier Venera data have greatly expanded the perception of the variety and complexity of geologic processes on Venus. PV data have discriminated four highland regions (each different in geomorphic appearance), a large upland rolling plains region, and smaller areas of lowland plains. Two highland volcanic centers were identified that may be presently active, as suggested by their geomorphologic appearance combined with positive gravity anomalies, lightning strike clusters, and a change in SO2 content in the upper atmosphere. Geochemical data obtained by the Venera landers have indicated that one upland area and nearby rolling plains are composed of volcanic rocks, probably basalts or syenites. New Venera radar images of the Ishtar Terra region show folded and/or faulted linear terrain and associated volcanic features that may have been deformed by both compressional and extensional forces. Lowland surfaces resemble the mare basaltic lava flows that fill basins on the Moon, Mars and Earth. Ubiquitous crater like forms may be of either volcanic or impact origin; the origin of similar lunar features was determined by the character of their ejecta deposits.

Masursky, H.

1985-01-01

26

The fundamental processes in ecology: a thought experiment on extraterrestrial biospheres.  

PubMed

Ecological science is often organised as a hierarchical series of entities: genes, individuals, populations, species, communities, ecosystems and biosphere. Here, I consider an alternative process-based approach to ecology, and analyse the nature of the fundamental processes in ecology. These fundamental processes are discussed in the context of the following question: 'for any planet with carbon-based life, which persists over geological time scales, what are the minimum set of ecological processes that must be present?' I suggest that the following processes would be present on any such planet: energy flow, multiple guilds, ecological trade-offs leading to within-guild biodiversity, ecological hypercycles, merging of organismal and ecological physiology, carbon sequestration and possibly photosynthesis. Nutrient cycling is described as an emergent property of these fundamental processes. I discuss reasons why a biosphere based on a single species with no nutrient cycling is very unlikely to exist. I also describe the concept of 'Gaian effect'. This suggests that some processes will always tend to extend the lifespan of a biosphere in which they develop (positive Gaian effect) while others could either increase or decrease (negative Gaian effect) such a lifespan. These ideas are discussed in the context of astrobiology, ecosystem services, conservation biology and Gaia theory. PMID:12803419

Wilkinson, David M

2003-05-01

27

FINAL REPORT. FUNDAMENTAL CHEMISTRY AND THERMODYNAMICS OF HYDROTHERMAL OXIDATION PROCESSES  

EPA Science Inventory

The goal of this project was to address issues of fundamental chemistry and thermodynamic properties that currently limit the applicability of hydrothermal oxidation processes to the treatment of hazardous and radioactive DOE wastes. The primary issues are related to corrosion, i...

28

Investigating the Fundamental Scientific Issues Affecting the Long-term Geologic Storage of Carbon Dioxide  

SciTech Connect

The Zero Emissions Research and Technology (ZERT) collaborative was formed to address basic science and engineering knowledge gaps relevant to geologic carbon sequestration. The original funding round of ZERT (ZERT I) identified and addressed many of these gaps. ZERT II has focused on specific science and technology areas identified in ZERT I that showed strong promise and needed greater effort to fully develop. Specific focal areas of ZERT II included: ? Continued use of the unique ZERT field site to test and prove detection technologies and methods developed by Montana State University, Stanford, University of Texas, several private sector companies, and others. Additionally, transport in the near surface was modelled. ? Further development of near-surface detection technologies that cover moderate area at relatively low cost (fiber sensors and compact infrared imagers). ? Investigation of analogs for escape mechanisms including characterization of impact of CO2 and deeper brine on groundwater quality at a natural analog site in Chimayo, NM and characterization of fracture systems exposed in outcrops in the northern Rockies. ? Further investigation of biofilms and biomineralization for mitigation of small aperture leaks focusing on fundamental studies of rates that would allow engineered control of deposition in the subsurface. ? Development of magnetic resonance techniques to perform muti-phase fluid measurements in rock cores. ? Laboratory investigation of hysteretic relative permeability and its effect on residual gas trapping in large-scale reservoir simulations. ? Further development of computational tools including a new version (V2) of the LBNL reactive geochemical transport simulator, TOUGHREACT, extension of the coupled flow and stress simulation capabilities in LANL’s FEHM simulator and an online gas-mixtureproperty estimation tool, WebGasEOS Many of these efforts have resulted in technologies that are being utilized in other field tests or demonstration projects.

Spangler, Lee; Cunningham, Alfred; Barnhart, Elliot; Lageson, David; Nall, Anita; Dobeck, Laura; Repasky, Kevin; Shaw, Joseph; Nugent, Paul; Johnson, Jennifer; Hogan, Justin; Codd, Sarah; Bray, Joshua; Prather, Cody; McGrail, B.; Oldenburg, Curtis; Wagoner, Jeff; Pawar, Rajesh

2014-09-30

29

Abstracts for the Planetary Geology Field Conference on Aeolian Processes  

NASA Technical Reports Server (NTRS)

The Planetary Geology Field Conference on Aeolian Processes was organized at the request of the Planetary Geology Program office of the National Aeronautics and Space Administration to bring together geologists working on aeolian problems on earth and planetologists concerned with similar problems on the planets. Abstracts of papers presented at the conference are arranged herein by alphabetical order of the senior author. Papers fall into three broad categories: (1) Viking Orbiter and Viking Lander results on aeolian processes and/or landforms on Mars, (2) laboratory results on studies of aeolian processes, and (3) photogeology and field studies of aeolian processes on Earth.

Greeley, R. (editor); Black, D. (editor)

1978-01-01

30

Geologic processes influence the effects of mining on aquatic ecosystems  

USGS Publications Warehouse

Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as “historically mined” or “unmined,” and based on mineral-deposit criteria, to determine whether water and sediment quality were influenced by naturally occurring mineralized rock, by historical mining, or by a combination of both. By accounting for different geologic sources of metals to the environment, we were able to distinguish aquatic ecosystems limited by metals derived from natural processes from those due to mining. Elevated concentrations of metals in water and sediment were not restricted to mined catchments; depauperate aquatic communities were found in unmined catchments. The type and intensity of hydrothermal alteration and the mineral deposit type were important determinants of water and sediment quality as well as the aquatic community in both mined and unmined catchments. This study distinguished the effects of different rock types and geologic sources of metals on ecosystems by incorporating basic geologic processes into reference and baseline site selection, resulting in a refined assessment. Our results indicate that biomonitoring studies should account for natural sources of metals in some geologic environments as contributors to the effect of mines on aquatic ecosystems, recognizing that in mining-impacted drainages there may have been high pre-mining background metal concentrations.

Schmidt, Travis S.; Clements, William H.; Wanty, Richard B.; Verplanck, Philip L.; Church, Stanley E.; San Juan, Carma A.; Fey, David L.; Rockwell, Barnaby W.; DeWitt, Ed H.; Klein, Terry L.

2012-01-01

31

Geologic processes influence the effects of mining on aquatic ecosystems.  

PubMed

Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as "historically mined" or "unmined," and based on mineral-deposit criteria, to determine whether water and sediment quality were influenced by naturally occurring mineralized rock, by historical mining, or by a combination of both. By accounting for different geologic sources of metals to the environment, we were able to distinguish aquatic ecosystems limited by metals derived from natural processes from those due to mining. Elevated concentrations of metals in water and sediment were not restricted to mined catchments; depauperate aquatic communities were found in unmined catchments. The type and intensity of hydrothermal alteration and the mineral deposit type were important determinants of water and sediment quality as well as the aquatic community in both mined and unmined catchments. This study distinguished the effects of different rock types and geologic sources of metals on ecosystems by incorporating basic geologic processes into reference and baseline site selection, resulting in a refined assessment. Our results indicate that biomonitoring studies should account for natural sources of metals in some geologic environments as contributors to the effect of mines on aquatic ecosystems, recognizing that in mining-impacted drainages there may have been high pre-mining background metal concentrations. PMID:22645817

Schmidt, Travis S; Clements, William H; Wanty, Richard B; Verplanck, Philip L; Church, Stanley E; San Juan, Carma A; Fey, David L; Rockwell, Barnaby W; DeWitt, Ed H; Klein, Terry L

2012-04-01

32

Geology of the Icy Galilean Satellites: Understanding Crustal Processes and Geologic Histories Through the JIMO Mission  

NASA Technical Reports Server (NTRS)

Knowledge of the geology, style and time history of crustal processes on the icy Galilean satellites is necessary to understanding how these bodies formed and evolved. Data from the Galileo mission have provided a basis for detailed geologic and geo- physical analysis. Due to constrained downlink, Galileo Solid State Imaging (SSI) data consisted of global coverage at a -1 km/pixel ground sampling and representative, widely spaced regional maps at -200 m/pixel. These two data sets provide a general means to extrapolate units identified at higher resolution to lower resolution data. A sampling of key sites at much higher resolution (10s of m/pixel) allows evaluation of processes on local scales. We are currently producing the first global geological map of Europa using Galileo global and regional-scale data. This work is demonstrating the necessity and utility of planet-wide contiguous image coverage at global, regional, and local scales.

Figueredo, P. H.; Tanaka, K.; Senske, D.; Greeley, R.

2003-01-01

33

Scaling filtering and multiplicative cascade information integration techniques for geological, geophysical and geochemical data processing and geological feature recognition  

NASA Astrophysics Data System (ADS)

This paper introduces several techniques recently developed based on the concepts of multiplicative cascade processes and multifractals for processing exploration geochemical and geophysical data for recognition of geological features and delineation of target areas for undiscovered mineral deposits. From a nonlinear point of view extreme geo-processes such as cloud formation, rainfall, hurricanes, flooding, landslides, earthquakes, igneous activities, tectonics and mineralization often show singular property that they may result in anomalous amounts of energy release or mass accumulation that generally are confined to narrow intervals in space or time. The end products of these non-linear processes have in common that they can be modeled as fractals or multifractals. Here we show that the three fundamental concepts of scaling in the context of multifractals: singularity, self-similarity and fractal dimension spectrum, make multifractal theory and methods useful for geochemical and geophysical data processing for general purposes of geological features recognition. These methods include: a local singularity analysis based on a area-density (C-A) multifractal model used as a scaling high-pass filtering technique capable of extracting weak signals caused by buried geological features; a suite of multifractal filtering techniques based on spectrum density - area (S-A) multifractal models implemented in various domain including frequency domain can be used for unmixing geochemical or geophysical fields according to distinct generalized self-similarities characterized in certain domain; and multiplicative cascade processes for integration of diverse evidential layers of information for prediction of point events such as location of mineral deposits. It is demonstrated by several case studies involving Fe, Sn, Mo-Ag and Mo-W mineral deposits that singularity method can be utilized to process stream sediment/soil geochemical data and gravity/aeromagnetic data as high-pass filtering technique for delineating anomalies caused by mineralization or boundaries of mineralization-associated geological bodies; S-A method can be applied as high-pass, low-pass or band -pass filtering techniques for extracting patterns of interest from mixing data; and cascade processes can be implemented to integrate diverse layers of information for mineral resources predictive mapping.

Cheng, Q.

2013-12-01

34

Geological Disposal Concept Selection Aligned with a Voluntarism Process - 13538  

SciTech Connect

The UK's Radioactive Waste Management Directorate (RWMD) is currently at a generic stage in its implementation programme. The UK site selection process is a voluntarist process and, as yet, no communities have decided to participate. RWMD has set out a process to describe how a geological disposal concept would be selected for the range of higher activity wastes in the UK inventory, including major steps and decision making points, aligned with the stages of the UK site selection process. A platform of information is being developed on geological disposal concepts at various stages of implementation internationally and, in order to build on international experience, RWMD is developing its approach to technology transfer. The UK has a range of different types of higher activity wastes with different characteristics; therefore a range of geological disposal concepts may be needed. In addition to identifying key aspects for considering the compatibility of different engineered barrier systems for different types of waste, RWMD is developing a methodology to determine minimum separation distances between disposal modules in a co-located geological disposal facility. RWMD's approach to geological disposal concept selection is intended to be flexible, recognising the long term nature of the project. RWMD is also committed to keeping alternative radioactive waste management options under review; an approach has been developed and periodic reviews of alternative options will be published. (authors)

Crockett, Glenda; King, Samantha [Nuclear Decommissioning Authority, Building 587, Curie Avenue, Harwell Oxford, Didcot, Oxfordshire, OX11 0RH (United Kingdom)] [Nuclear Decommissioning Authority, Building 587, Curie Avenue, Harwell Oxford, Didcot, Oxfordshire, OX11 0RH (United Kingdom)

2013-07-01

35

Geology  

SciTech Connect

This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region’s geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

Reidel, Stephen P.

2008-01-17

36

Fundamental Processes of Atomization in Fluid-Fluid Flows  

NASA Technical Reports Server (NTRS)

This report outlines the major results of the grant "Fundamental Processes of Atomization in Fluid-Fluid Flows." These include: 1) the demonstration that atomization in liquid/liquid shear flow is driven by a viscous shear instability that triggers the formation of a long thin sheet; 2) discovery of a new mode of interfacial instability for oscillatory two-layer systems whereby a mode that originates within the less viscous liquid phase causes interfacial deformation as the oscillation proceeds; 3) the demonstration that rivulet formation from gravity front occurs because the local front shape specified by gravity and surface tension changes from a nose to a wedge geometry, thus triggering a large increase in viscous resistance; and 4) extension of the studies on nonlinear wave evolution on falling films and in stratified flow, particularly the evolution towards large-amplitude solitary waves that tend to generate drops.

McCready, M. J.; Chang, H.-C.; Leighton, D. T.

2001-01-01

37

Fundamentals of the Cyclotron Up-Scattering Process  

SciTech Connect

Gamma-ray bursts (GRBs) remain an enigmatic astrophysical phenomenon some 20 years after their discovery. One of their unique characteristics is their continuum spectra which tend to be deficient in soft X-rays. Most of the energy of continuum emission comes from photons with energy above 100 keV (Epstein 1986). Following the recent detection of double absorption features in GB870303 and GB880205, and the interpretation of these features as the fundamental and first harmonic cyclotron lines great interest has been aroused in the mechanism of continuum emission in a strong magnetic field. In this paper, we describe some basic results of the production of continuum emission via up-scattering of low energy photons by relativistic electrons in a magnetic field. The dominant process is the cyclotron resonant scattering which we refer to as the Cyclotron Up-Scattering Process. See Ho and Epstein (1989a) for discussions on the non-magnetic (Compton) up-scattering process. A more detailed discussion of this work is presented in a separate paper (Ho, Epstein and Fenimore 1991).

Ho, Cheng; Epstein, R.I.; Fenimore, E.E.

1991-12-31

38

Fundamentals of the Cyclotron Up-Scattering Process  

SciTech Connect

Gamma-ray bursts (GRBs) remain an enigmatic astrophysical phenomenon some 20 years after their discovery. One of their unique characteristics is their continuum spectra which tend to be deficient in soft X-rays. Most of the energy of continuum emission comes from photons with energy above 100 keV (Epstein 1986). Following the recent detection of double absorption features in GB870303 and GB880205, and the interpretation of these features as the fundamental and first harmonic cyclotron lines great interest has been aroused in the mechanism of continuum emission in a strong magnetic field. In this paper, we describe some basic results of the production of continuum emission via up-scattering of low energy photons by relativistic electrons in a magnetic field. The dominant process is the cyclotron resonant scattering which we refer to as the Cyclotron Up-Scattering Process. See Ho and Epstein (1989a) for discussions on the non-magnetic (Compton) up-scattering process. A more detailed discussion of this work is presented in a separate paper (Ho, Epstein and Fenimore 1991).

Ho, Cheng; Epstein, R.I.; Fenimore, E.E.

1991-01-01

39

Magnetic Reconnection: A Fundamental Process in Space Plasmas  

NASA Technical Reports Server (NTRS)

For many years, collisionless magnetic reconnect ion has been recognized as a fundamental process, which facilitates plasma transport and energy release in systems ranging from the astrophysical plasmas to magnetospheres and even laboratory plasma. Beginning with work addressing solar dynamics, it has been understood that reconnection is essential to explain solar eruptions, the interaction of the solar wind with the magnetosphere, and the dynamics of the magnetosphere. Accordingly, the process of magnetic reconnection has been and remains a prime target for space-based and laboratory studies, as well as for theoretical research. Much progress has been made throughout the years, beginning with indirect verifications by studies of processes enabled by reconnection, such as Coronal Mass Ejections, Flux Transfer Events, and Plasmoids. Theoretical advances have accompanied these observations, moving knowledge beyond the Sweet-Parker theory to the recognition that other, collisionless, effects are available and likely to support much faster reconnect ion rates. At the present time we are therefore near a break-through in our understanding of how collisionless reconnect ion works. Theory and modeling have advanced to the point that two competing theories are considered leading candidates for explaining the microphysics of this process. Both theories predict very small spatial and temporal scales. which are. to date, inaccessible to space-based or laboratory measurements. The need to understand magnetic reconnect ion has led NASA to begin the implementation of a tailored mission, Magnetospheric MultiScale (MMS), a four spacecraft cluster equipped to resolve all relevant spatial and temporal scales. In this presentation, we present an overview of current knowledge as well as an outlook towards measurements provided by MMS.

Hesse, Michael

2010-01-01

40

On fundamental cellular processes for emergence of collective epithelial movement  

PubMed Central

Summary In all animals, collective cell movement is an essential process in many events, including wound healing and embryonic development. However, our understanding of what characterizes the emergence of multicellular collective behavior is still far from complete. In this article we showed the fundamental cellular processes that drive collective cell movement by means of integrated approaches, including precise quantification measurements and mathematical modeling of measured data. First, we observed the dependence of the collective behaviors of cultured human skin cells on Ca2+ concentrations. When the culturing area confined by a PDMS sheet was suddenly expanded by removing the sheet, the group of cells moved to the expanded area with higher collectivity at higher Ca2+ concentrations. Next, we quantitatively measured cellular responses to the Ca2+ treatments, such as cell growth, cell division, and the strength of intercellular adhesion. Using a femtosecond-laser-based assay, an original method for estimating intercellular adhesion, we found that the strength of intercellular adhesion has an approximately 13-fold range in our treatments. Incorporating the quantitative data into a mathematical model, we then confirmed that the model well reproduced the multicellular behaviors we observed, demonstrating that the strength of intercellular adhesion sufficiently determines the generation of collective cell movement. Finally, we performed extensive numerical experiments, and the results suggested that the emergence of collective cell movement is derived by an optimal balance between the strength of intercellular adhesion and the intensity of cell migration. PMID:23862013

Hirashima, Tsuyoshi; Hosokawa, Yoichiroh; Iino, Takanori; Nagayama, Masaharu

2013-01-01

41

Will Somebody do the Dishes? Weathering Analogies, Geologic Processes and Geologic Time  

NASA Astrophysics Data System (ADS)

A good analogy is one of the most powerful tools in any instructors' arsenal, and encouraging students to explore the links between an analogy and a scientific concept can cement both ideas in a student's mind. A common analogy for weathering and erosion processes is doing the dishes. Oxidation, hydration, and solution reactions can be intimidating on the chalkboard but easily understood in the context of cleaning up after dinner. Rather than present this analogy as a lecture demonstration, students are encouraged to experimentally determine which type of weathering works best on their dirty dishes. The experiment must use at least four identically dirty dishes: three experimental dishes and one control dish. The experimental dishes are subjected to simulated weathering and erosion processes of the student's design. Common techniques developed by students are cold or warm water baths, baths with and without acid (lemon juice or soda), and freeze-thaw cycles. Occasionally creative experiments result in unexpected discoveries, such the inefficiency of abrasion from wind-blown sand, especially when compared to soaking dishes in Canadian Whiskey. The effectiveness of each experimental run is determined by comparison to the control plate after loose debris is removed from each. The dish with the smallest aerial extent of remaining food is the declared the most effective. Discussion sections of the experimental write-up includes a description of which geologic processes were being simulated in each experiment, comparisons of the effectiveness of each techniques, and statements of how these experiments differ from reality. In order to advance this project, a second stage of the assignment, a direct comparison of weathering and erosion techniques on food and on geologic materials, will be added this fall. Ideally, students will empirically derive erosion rates and calculate the time required to remove the volume of material represented by a geologically important feature, such as Mt. Rainier or the Grand Canyon. In the end, students completing this project gain an understanding of how geologic processes work, the time scales required, the differences between analogies and the real thing, and arguably the most important aspect, a best-practices approach to doing the dishes.

Stelling, P.; Wuotila, S.; Giuliani, M.

2006-12-01

42

Enrichment and Fundamental Optical Processes of Armchair Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

The armchair variety of single-wall carbon nanotubes (SWCNTs) is the only nanotube species that behaves as a metal with no electronic band gap and massless carriers, making them ideally suited to probe fundamental questions of many-body physics of one-dimensional conductors as well as to serve in applications such as highcurrent power transmission cables. However, current methods of nanotube synthesis produce bulk material comprising of a mixture of nanotube lengths, diameters, wrapping angles, and electronic types due to the inability to control the growth process at the nanometer level. As a result, measurements of as-grown SWCNTs produce a superposition of electrical and optical responses from multiple SWCNT species. This thesis demonstrates production of aqueous suspensions composed almost entirely of armchair SWCNTs using a post-synthesis separation method employing density gradient ultracentrifugation (DGU) to separate different SWCNT types based on their mass density and surfactant-specific interactions. Resonant Raman spectroscopy determines the relative abundances of each nanotube species, before and after DGU, by measuring the integrated intensity of the radial breathing mode, the diameter-dependent radial vibration of the SWCNT perpendicular to its main axis, and quantifies the degree of enrichment of bulk nanotube samples to exclusively armchair tubes. Raman spectroscopy of armchair-enriched samples of the G-band mode, which is composed of longitudinal (G-) and circumferential (G+) vibrations oscillating parallel and perpendicular to the tube axis, shows that the G- peak, long-held to be an indicator for the presence of metallic SWCNTs, appears only when electronic resonance with narrow-gap semiconducting SWCNTs occurs and shows only the G+ component in spectra containing only armchair species. Finally, by combining optical absorption measurements with nanotube composition as determined earlier via Raman scattering, peak fitting of absorption spectra indicates that interband transitions of armchair SWCNTs are strongly excitonic as shown by the highly symmetric peak lineshapes, a property normally attributed to semiconductors. Such lineshapes allow classification of armchair SWCNTs as a unique hybrid class of optical nanomaterial. Combining absorption and Raman scattering measurements establishes a distinct optical signature that describes the fundamental optical processes within armchair SWCNTs and lays the foundation for future studies of many-body photophysics and electrical applications.

Haroz, Erik H.

43

Online Courses: Mississippi State University: Geology I: Processes and Products  

NSDL National Science Digital Library

Does your curriculum include concepts in geology? Do you need to continue your education in earth science? Geology I from the Teachers in Geosciences covers the foundational material in physical geology that you need to understand to successfully teach

1900-01-01

44

Modeling the fundamental characteristics and processes of the spacecraft functioning  

NASA Technical Reports Server (NTRS)

The fundamental aspects of modeling of spacecraft characteristics by using computing means are considered. Particular attention is devoted to the design studies, the description of physical appearance of the spacecraft, and simulated modeling of spacecraft systems. The fundamental questions of organizing the on-the-ground spacecraft testing and the methods of mathematical modeling were presented.

Bazhenov, V. I.; Osin, M. I.; Zakharov, Y. V.

1986-01-01

45

THE ROLE OF PORE PRESSURE IN DEFORMATION IN GEOLOGIC PROCESSES  

SciTech Connect

A Penrose Conference entitled, "The Role of Pore Pressure in Deformation in Geologic Processes" was convened by the authors at San Diego, California between November 9 and 13, 1979. The conference was sponsored by the Geological Society of America. This report is a summary of the highlights of the issues discussed during the conference. In addition, this report also includes a topical reference list relating to the different subject areas relevant to pore pressure and deformation. The references were compiled from a list suggested by the participants and were available for consultation during the conference. Although the list is far from complete, it should prove to be a good starting point for one who is looking for key papers in the field.

Narasimhan, T. N.; Houston, W. N.; Nur, A. M.

1980-03-01

46

Processing of multispectral thermal IR data for geologic applications  

NASA Technical Reports Server (NTRS)

Multispectral thermal IR data were acquired with a 24-channel scanner flown in an aircraft over the E. Tintic Utah mining district. These digital image data required extensive computer processing in order to put the information into a format useful for a geologic photointerpreter. Simple enhancement procedures were not sufficient to reveal the total information content because the data were highly correlated in all channels. The data were shown to be dominated by temperature variations across the scene, while the much more subtle spectral variations between the different rock types were of interest. The image processing techniques employed to analyze these data are described.

Kahle, A. B.; Madura, D. P.; Soha, J. M.

1979-01-01

47

Fundamental studies of catalytic processing of synthetic liquids  

SciTech Connect

This project revolves around understanding the fundamental processes involved in the catalytic removal of harmful oxygenated organics present in coal liquids. We are modelling the complex type of sulfided Mo catalyst proposed for these reactions with simple single crystal surfaces. These display a controlled range and number of reaction sites and can be extensively characterized by surface science techniques. We then investigate the reaction pathways for representative simple oxygenates upon these surfaces. Our previous work has shown that an important component of furan reactions on sulfided Mo surfaces are dehydrogenation reactions of adsorbed hydrocarbon fragments. The desorption of hydrogen occurs in several steps and is strongly influenced by the amounts of sulfur and carbon on the surface. In order to understand this complex behavior during this period we have performed a complete series of adsorption/desorption experiments for hydrogen (deuterium) on Mo(110) that has been prepared with varying amounts of carbon and sulfur on the surface. Hydrogen adsorption is blocked by preadsorbed sulfur with a dramatic weakening of the strength with which hydrogen is bound to the surface. Hydrogen adsorption is totally blocked by 0.5 ML of preadsorbed sulfur. 4 refs., 9 figs.

Watson, P.R.

1991-10-14

48

Fundamental studies of catalytic processing of synthetic liquids. Final report  

SciTech Connect

Liquids derived from coal contain relatively high amounts of oxygenated organic compounds, mainly in the form of phenols and furans that are deleterious to the stability and quality of these liquids as fuels. Hydrodeoxygenation (HDO) using Mo/W sulfide catalysts is a promising method to accomplish this removal, but our understanding of the reactions occurring on the catalyst surface during HDO is very limited. Rather than attempting to examine the complexities of real liquids and catalysts we have adopted an approach here using model systems amenable to surface-sensitive techniques that enable us to probe in detail the fundamental processes occurring during HDO at the surfaces of well-defined model catalysts. The results of this work may lead to the development of more efficient, selective and stable catalysts. Above a S/Mo ratio of about 0.5 ML, furan does not adsorb on sulfided Mo surfaces; as the sulfur coverage is lowered increasing amounts of furan can be adsorbed. Temperature-programmed reaction spectroscopy (TPRS) reveals that C-H, C-C and C-O bond scission occurs on these surfaces. Auger spectra show characteristic changes in the nature and amount of surface carbon. Comparisons with experiments carried out with CO, H{sub 2} and alkenes show that reaction pathways include -- direct abstraction of CO at low temperatures; cracking and release of hydrogen below its normal desorption temperature; dehydrogenatin of adsorbed hydrocarbon fragments; recombination of C and O atoms and dissolution of carbon into the bulk at high temperatures. Performing the adsorption or thermal reaction in 10{sup {minus}5} torr of hydrogen does not change the mode of reaction significantly.

Watson, P.R.

1994-06-15

49

Techniques for determining probabilities of events and processes affecting the performance of geologic repositories: Literature review  

Microsoft Academic Search

The US Environmental Protection Agency (EPA) has set a probabilistic standard for the performance of geologic repositories for the disposal of radioactive waste. This report treats not only geologic events and processes like fault movement, but also events and processes that arise from the relationship between human actions and geology, like drilling for resources, and some that arise from nongeologic

R. L. Hunter; C. J. Mann

1989-01-01

50

From Fundamental Physical Fluvial Processes To River Patterns  

NASA Astrophysics Data System (ADS)

Rivers are ubiquitous on planetary surfaces and their patterns show great variation. The fundamental fluvial processes of flow and sediment transport are relatively well understood, solvable in linearized form and implemented in sophisticated nonlinear numerical models. We successfully modeled formation and evolution of large-scale and long-term patterns that look like braided and meandering river. But what characterizes and discriminates the patterns, and how do the modeled patterns quantitatively compare to natural patterns? Here we focus on characteristics of fluvial bars as building blocks of river patterns. Bars are much larger than grid cells and emerge at length scales predictable by analytical solutions. We used the morphodynamic numerical model Delft3D, which solves the 3D flow and computes sediment transport and bed level change, incorporating the effect of transverse bed slope. We identify bars as connected sand bodies above the average bed level and characterize their shape quantitatively. To reduce computational time and allow high resolution long-term calculations, bed level changes are multiplied by a morphological factor O(100) for each flow time step. This assumes that no significant morphodynamics occur at the time scale in which significant flow takes place. At the moment, desktop computers allow high-resolution century-scale calculations for the largest rivers on Earth. The results show that both meandering and braiding rivers can be modeled by solving the flow and sediment dynamics, and can be characterized by bars. In meandering rivers streamline curvature and bank erosion leads to formation of scroll bars. In braided rivers, large compound bars are formed by merging of unit bars, forming scroll-bars, and smaller compound bars. The results show that nonlinear numerical solution of small-scale flow and sediment transport results in realistic large scale river patterns depending on boundary conditions. As attested by verification in many engineering applications of this model, a second-order (nonlinear) numerical scheme and the transverse bed slope effect are essential for accurate bar dimensions which have not been reproduced in cellular automata. We conclude that a reductionist approach at realistic fluvial landscape modeling is feasible given growing computing power, and successful when evaluated on quantitative characteristics of emergent landforms that compose the landscape.

Schuurman, F.; Kleinhans, M. G.; Geurts, A. H.

2012-12-01

51

Emerging Nanoscale Interconnect Processing Technologies: Fundamental and Practice  

Microsoft Academic Search

\\u000a The prospects for Gigascale integration and beyond are hindered, in the near term, by increasingly higher RC delays in global and semi-global electrical interconnect systems. Long-term, signal transmission delays are projected to\\u000a become significantly more challenging due to fundamental limits imposed by the basic laws of physics. As feature sizes shrink\\u000a below the mean free path for electron scattering in

Alain E. Kaloyeros; James Castracane; Kathleen Dunn; Eric Eisenbraun; Anand Gadre; Vincent Labella; Timothy Stoner; Bai Xu; James G. Ryan; Anna Topol

2009-01-01

52

Fundamentals of Alloy Solidification Applied to Industrial Processes  

NASA Technical Reports Server (NTRS)

Solidification processes and phenomena, segregation, porosity, gravity effects, fluid flow, undercooling, as well as processing of materials in the microgravity environment of space, now available on space shuttle flights were discussed.

1984-01-01

53

IDENTIFICATION AND EVALUATION OF FUNDAMENTAL TRANSPORT AND TRANSFORMATION PROCESS MODELS  

EPA Science Inventory

Chemical fate models require explicit algorithms for computing the effects of transformation and transport processes on the spatial and temporal distribution of chemical concentrations. Transport processes in aquatic systems are driven by physical characteristics on the system an...

54

Geology  

NSDL National Science Digital Library

With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on the many different kinds of geological exploration. The elements that make up minerals and the different ways minerals are developed, The special characteristics of minerals, like physical properties, is explained. Earths tectonic plates, the reasons they move, and the effects of the shifting are also given. Also featured is fossils and how they are developed and are found, as well as why fossils are useful tools for scientists.

Jennifer Bergman

2009-08-03

55

Venus and the Earth's Archean: Geological mapping and process comparisons  

NASA Astrophysics Data System (ADS)

Introduction. The geological features, structures, thermal conditions, interpreted processes, and outstanding questions related to both the Earth's Archean and Venus share many similarities [1-3] and we are using a problem-oriented approach to Venus mapping, guided by insight from the Archean record of the Earth, to gain new perspectives on the evolution of Venus and Earth's Archean. The Earth's preserved and well-documented Archean record [4] provides important insight into high heat-flux tectonic and magmatic environments and structures [5] and the surface of Venus reveals the current configuration and recent geological record of analogous high-temperature environments unmodified by subsequent several billion years of segmentation and overprinting, as on Earth. Here we address the nature of the Earth's Archean, the similarities to and differences from Venus, and the specific Venus and Earth-Archean problems on which progress might be made through comparison. The Earth's Archean and its Relation to Venus. The Archean period of Earth's history extends from accretion/initial crust formation (sometimes called the Hadean) to 2.5 Ga and is thought of by most workers as being a transitional period between the earliest Earth and later periods largely dominated by plate tectonics (Proterozoic and Phanerozoic) [2, 4]. Thus the Archean is viewed as recording a critical period in Earth's history in which a transition took place from the types of primary and early secondary crusts seen on the Moon, Mars and Mercury [6] (and largely missing in the record of the Earth), to the style of crustal accretion and plate tectonics characterizing later Earth history. The Archean is also characterized by enhanced crustal and mantle temperatures leading to differences in deformation style and volcanism (e.g., komatiites) [2]. The preserved Archean crust is exposed in ~36 different cratons [4], forming the cores of most continental regions, and is composed of gneisses, plutons and greenstones. The geological record of the Archean Earth is considerably different than the Phanerozoic record and ongoing processes [1, 7]. The Archean record is characterized by evidence for enhanced mantle temperatures, different styles of crustal deformation (localized belts of high intensity deformation, tight high and low angle folds, diapiric-related deformation, significant lateral differences in lithospheric thickness (implied by 'cold' keels), significant evidence for crustal thickening processes and the burial and exhumation of thickened crust, abundant hightemperature komatiites, greenstone belts, "mafic plains"-type greenstones, positive gneissic and felsic diapirs, abundance of a distinctive TTG (tonalitetrondhjemite- granodiorite) assemblage, layered gabbro- anorthosite igneous intrusions, very abundant plume-derived basalts, unusual events interpreted to represent mantle instability and overturn, late stage granodiorites and granites derived from intracrustal melting, epicratonic basins, and production of large volumes of continental crust [1,4,5]. A major question in the study of the Archean is the nature of the geodynamic processes operating during this time. Do the geodynamic processes represent a steady-state accommodation to the Archean thermal environment, or do they represent a transitional or evolutionary phase? Does the Archean represent a particular unique style of vertical tectonics, as on oneplate planets, lateral tectonics (perhaps early plate tectonics) as on later Earth, or is it transitional in time (and perhaps in space), changing from one style to another during the Archean? What role do the enhanced mantle and crustal temperatures play in volcanism and tectonism during this period? Do global crustal and lithospheric density instabilities play a major role in the transition [8], perhaps causing catastrophic foundering and crustal overturn [9], as thought to have occurred on the Moon and Mars? Does vertical crustal accretion dominate over lateral crustal accretion, leading to density instabilities and planet-wide diapiric upwel

Head, J. W.; Hurwitz, D. M.; Ivanov, M. A.; Basilevsky, A. T.; Senthil Kumar, P.

2008-09-01

56

SELF-DIALOGUE AS A FUNDAMENTAL PROCESS OF EXPRESSION  

E-print Network

Self-dialogue involves a constant process of demarcation and interaction between "I" and "me," between the speakable and the unspeakable, and between what is said and what is meant. This paper studies self-dialogue in its ...

Shaw, Victor N.

2001-04-01

57

Exclusive Processes and the Fundamental Structure of Hadrons  

DOE PAGESBeta

I review the historical development of QCD predictions for exclusive hadronic processes, beginning with constituent counting rules and the quark interchange mechanism, phenomena which gave early validation for the quark structure of hadrons. The subsequent development of pQCD factorization theorems for hard exclusive amplitudes and the development of evolution equations for the hadron distribution amplitudes provided a rigorous framework for calculating hadronic form factors and hard scattering exclusive scattering processes at high momentum transfer. I also give a brief introduction to the field of "light-front holography" and the insights it brings to quark confinement, the behavior of the QCD coupling in the nonperturbative domain, as well as hadron spectroscopy and the dynamics of exclusive processes.

Brodsky, Stanley J.

2015-01-20

58

Beowulf Distributed Processing and the United States Geological Survey  

USGS Publications Warehouse

Introduction In recent years, the United States Geological Survey's (USGS) National Mapping Discipline (NMD) has expanded its scientific and research activities. Work is being conducted in areas such as emergency response research, scientific visualization, urban prediction, and other simulation activities. Custom-produced digital data have become essential for these types of activities. High-resolution, remotely sensed datasets are also seeing increased use. Unfortunately, the NMD is also finding that it lacks the resources required to perform some of these activities. Many of these projects require large amounts of computer processing resources. Complex urban-prediction simulations, for example, involve large amounts of processor-intensive calculations on large amounts of input data. This project was undertaken to learn and understand the concepts of distributed processing. Experience was needed in developing these types of applications. The idea was that this type of technology could significantly aid the needs of the NMD scientific and research programs. Porting a numerically intensive application currently being used by an NMD science program to run in a distributed fashion would demonstrate the usefulness of this technology. There are several benefits that this type of technology can bring to the USGS's research programs. Projects can be performed that were previously impossible due to a lack of computing resources. Other projects can be performed on a larger scale than previously possible. For example, distributed processing can enable urban dynamics research to perform simulations on larger areas without making huge sacrifices in resolution. The processing can also be done in a more reasonable amount of time than with traditional single-threaded methods (a scaled version of Chester County, Pennsylvania, took about fifty days to finish its first calibration phase with a single-threaded program). This paper has several goals regarding distributed processing technology. It will describe the benefits of the technology. Real data about a distributed application will be presented as an example of the benefits that this technology can bring to USGS scientific programs. Finally, some of the issues with distributed processing that relate to USGS work will be discussed.

Maddox, Brian G.

2002-01-01

59

Process for structural geologic analysis of topography and point data  

DOEpatents

A quantitative method of geologic structural analysis of digital terrain data is described for implementation on a computer. Assuming selected valley segments are controlled by the underlying geologic structure, topographic lows in the terrain data, defining valley bottoms, are detected, filtered and accumulated into a series line segments defining contiguous valleys. The line segments are then vectorized to produce vector segments, defining valley segments, which may be indicative of the underlying geologic structure. Coplanar analysis is performed on vector segment pairs to determine which vectors produce planes which represent underlying geologic structure. Point data such as fracture phenomena which can be related to fracture planes in 3-dimensional space can be analyzed to define common plane orientation and locations. The vectors, points, and planes are displayed in various formats for interpretation.

Eliason, Jay R. (Richland, WA); Eliason, Valerie L. C. (Richland, WA)

1987-01-01

60

Fundamental process and system design issues in CO2 vapor compression systems  

E-print Network

; Compressor; Heat exchanger Contents 1. Introduction of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign, 1206 West Green Street, air-conditioning and heat pump applications. The focus will be on fundamental process and system

Bahrami, Majid

61

Fundamental processes in the interacting boson model: 0{nu}{beta}{beta} decay  

SciTech Connect

A program to calculate nuclear matrix elements for fundamental processes in the interacting boson model has been initiated. Results for the nuclear matrix elements in neutrinoless double beta decay 0{nu}{beta}{beta} are presented.

Iachello, F. [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120 (United States); Barea, J. [Departamento de Fisica, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)

2011-05-06

62

Geologic versus wildfire controls on hillslope processes and debris flow initiation in the Green River canyons  

E-print Network

Geologic versus wildfire controls on hillslope processes and debris flow initiation in the Green are unknown. A recent episode of enhanced debris-flow and wildfire activity provided an opportunity to examine with recent debris flows to determine how surficial geology, wildfire, topography, bedrock strength

Pederson, Joel L.

63

Integration of geostatistical techniques and intuitive geology in the 3-D modeling process  

SciTech Connect

The development of 3-D geologic models for reservoir description and simulation has traditionally relied on the computer derived interpolation of well data in a geocelluar stratigraphic framework. The quality of the interpolation has been directly dependent on the nature of the interpolation method, and ability of the interpolation scheme to accurately predict the value of geologic attributes away from the well. Typically, interpolation methods employ deterministic or geostatistical algorithms which offer limited capacity for integrating data derived from secondary analyses. These secondary analyses, which might include the results from 3-D seismic inversion, borehole imagery studies, or deductive reasoning, introduce a subjective component into what would otherwise be restricted to a purely mathematical treatment of geologic data. At Saudi ARAMCO an increased emphasis is being placed on the role of the reservoir geologist in the development of 3-D geologic models. Quantitative results, based on numerical computations, are being enhanced with intuitive geology, derived from years of cumulative professional experience and expertise. Techniques such as template modeling and modified conditional simulation, are yielding 3-D geologic models, which not only more accurately reflect the geology of the reservoir, but also preserve geologic detail throughout the simulation process. This incorporation of secondary data sources and qualitative analysis has been successfully demonstrated in a clastic reservoir environment in Central Saudi Arabia, and serves as a prototype for future 3-D geologic model development.

Heine, C.J.; Cooper, D.H. [Saudi ARAMCO, Dhahran (Saudi Arabia)

1995-08-01

64

Integration of geostatistical techniques and intuitive geology in the 3-D modeling process  

SciTech Connect

The development of 3-D geologic models for reservoir description and simulation has traditionally relied on the computer derived interpolation of well data in a geocelluar stratigraphic framework. The quality of the interpolation has been directly dependent on the nature of the interpolation method, and ability of the Interpolation scheme to accurately predict the value of geologic attributes away from the well. Typically, interpolation methods employ deterministic or geostatistical algorithms which offer limited capacity for Integrating data derived from secondary analyses. These secondary analyses, which might include the results from 3-D seismic inversion, borehole imagery studies, or deductive reasoning, introduce a subjective component into what would otherwise be restricted to a purely mathematical treatment of geologic data. At Saudi ARAMCO an increased emphases is being placed on the role of the reservoir geologist in the development of 3-D geologic models. Quantitative results, based on numerical computations, are being enhanced with intuitive geology, derived from years of cumulative professional experience and expertise. Techniques such as template modeling and modified conditional simulation, are yielding 3-D geologic models, which not only more accurately reflect the geology of the reservoir, but also preserve geologic detail throughout the simulation process. This incorporation of secondary data sources and qualitative analysis has been successfully demonstrated in a clastic reservoir environment in Central Saudi Arabia, and serves as a prototype for future 3-D geologic model development.

Heine, C.J.; Cooper, D.H. (Saudi ARAMCO, Dhahran (Saudi Arabia))

1996-01-01

65

Integration of geostatistical techniques and intuitive geology in the 3-D modeling process  

SciTech Connect

The development of 3-D geologic models for reservoir description and simulation has traditionally relied on the computer derived interpolation of well data in a geocelluar stratigraphic framework. The quality of the interpolation has been directly dependent on the nature of the interpolation method, and ability of the Interpolation scheme to accurately predict the value of geologic attributes away from the well. Typically, interpolation methods employ deterministic or geostatistical algorithms which offer limited capacity for Integrating data derived from secondary analyses. These secondary analyses, which might include the results from 3-D seismic inversion, borehole imagery studies, or deductive reasoning, introduce a subjective component into what would otherwise be restricted to a purely mathematical treatment of geologic data. At Saudi ARAMCO an increased emphases is being placed on the role of the reservoir geologist in the development of 3-D geologic models. Quantitative results, based on numerical computations, are being enhanced with intuitive geology, derived from years of cumulative professional experience and expertise. Techniques such as template modeling and modified conditional simulation, are yielding 3-D geologic models, which not only more accurately reflect the geology of the reservoir, but also preserve geologic detail throughout the simulation process. This incorporation of secondary data sources and qualitative analysis has been successfully demonstrated in a clastic reservoir environment in Central Saudi Arabia, and serves as a prototype for future 3-D geologic model development.

Heine, C.J.; Cooper, D.H. [Saudi ARAMCO, Dhahran (Saudi Arabia)

1996-12-31

66

Digitizing rocks standardizing the geological description process using workstations  

SciTech Connect

The preservation of geological knowledge in a standardized digital form presents a challenge. Data sources, inherently fuzzy, range in scale from the macroscopic (e.g., outcrop) through the mesoscopic (e.g., hand-specimen) core and sidewall core, to the microscopic (e.g., drill cuttings, thin sections, and microfossils). Each scale change results in increased heterogeneity and potentially contradictory data and the providers of such data may vary in experience level. To address these issues with respect to cores and drill cuttings, a geological description workstation has been developed and is undergoing field trials. Over 1000 carefully defined geological attributes are currently available within a depth-indexed, relational database. Attributes are stored in digital form, allowing multiple users to select familiar usage (e.g., diabase vs. dolerite). Data can be entered in one language and retrieved in other languages. The database structure allow groupings of similar elements (e.g., rhyolites in acidic, igneous or volcanics subgroups or the igneous rock group) permitting different uses to analyze details appropriate to the scale of the usage. Data entry uses a graphical user interface, allowing the geologist to make quick, logical selections in a standardized or custom-built format with extensive menus, on-screen graphics and help screens available. Description ranges are permissible. Entries for lithology, petrology, structures (sedimentary, organic and deformational), reservoir characteristics (porosity and hydrocarbon shows), and macrofossils are available. Sampling points for thin sections, core analysis, geochemistry, or micropaleontology studies are also recorded. Using digital data storage, geological logs using graphical, alphanumeric and symbolic depictions are possible. Data can be integrated with drilling and mud gas data, MWD and wireline data and off well-site analyses to produced composite formation evaluation logs and interpretational crossplots.

Saunders, M.R. (EXLOG (Services), Windsor, Berkshire (United Kingdom)); Shields, J.A. (EXLOG North Sea, Aberdeen (United Kingdom)); Taylor, M.R. (EXLOG, Inc., Houston, TX (United States))

1993-09-01

67

The lively Aysén fjord, Chile: Records of multiple geological processes  

NASA Astrophysics Data System (ADS)

The Aysén fjord is a 65 km long, east-west oriented fjord in Chilean Patagonia, located approximately at 45.4ºS and 73.2ºW, with a maximum water depth of 345 m. The fjord receives at present the riverine input of Aysén, Pescado, Condor and Cuervo rivers, which drain the surrounding up to 2000 m high Patagonian Andes. The fjord is crossed by a number of faults associated to the seismically active Liquiñe-Ofqui Fault Zone, a major trench parallel intra-arc fault system. After a four-month period of moderate seismicity, an Mw 6.2 earthquake on 21 April 2007 triggered dozens of subaerial landslides along the fjord flanks. Some of the landslides reached the fjord water mass, generating a series of tsunami-like displacement waves that impacted the adjacent coastlines with 3-12 m, locally over 50 m high run-ups, causing ten fatalities and severe damage to salmon farms. The research cruise DETSUFA on board BIO Hespérides in March 2013 mapped the submerged morphology of the fjord and gathered air-gun seismic profiles and sediment gravity cores in order to characterise the footprint of the landslides in the fjord floor. Very-high resolution multibeam bathymetry (4 m cell size) clearly shows the deformation structures created by the landslides in the inner fjord. The landslides descended and accelerated down the submerged fjord flanks, and reached the fjord floor at approx. 200 m water depth generating large, 1 to 10 m deep impact depressions. Sediment removed from these depressions moved radially and piled up in deformation rings formed by compressional ridges 10-15 m in height, block fields and a narrow frontal depression. Up to six >1.5 square km of these structures can be identified in the fjord. In addition, the DETSUFA survey extended beyond the SE-NW-oriented inner fjord past the Cuervo Ridge, located in front of the Cuervo river delta. The ridge, previously interpreted as a volcanic transverse structure, has most probably acted as a limit for grounding ice in the past, as suggested by the presence of melt-water channels lateral to the ridge. Beyond the ridge, the fjord smoothens and deepens to more than 330 m forming an enclosed basin before turning SW. There, it shallows back across a field of streamlined submerged hills of glacial origin. The external Aysén fjord, before joining to Canal Costa and Canal Moraleda, is characterized by three volcanic cones, one of them forming Isla Colorada - which also acted as a glacial limit - and the other two totally submerged and previously unknown. The largest one is 160 m high, 1.3 km in diameter and tops at 67 m water depth. This data set illustrates the complex interaction between fluvial, glacial, tectonic, volcanic and gravity processes and evidences the recent lively geological history of Aysén fjord.

Lastras, Galderic; Amblas, David; Calafat, Antoni; Canals, Miquel; Frigola, Jaime; Hermanns, Reginald L.; Lafuerza, Sara; Longva, Oddvar; Micallef, Aaron; Sepúlveda, Sergio A.; Vargas, Gabriel; Azpiroz, María; Bascuñán, Ignacio; Duhart, Paul; Iglesias, Olaia; Kempf, Philipp; Rayo, Xavier

2014-05-01

68

FUNDAMENTAL STUDIES OF IGNITION PROCESSES IN LARGE NATURAL GAS ENGINES USING LASER SPARK IGNITION  

Microsoft Academic Search

The current report details project progress made during the first quarterly reporting period of the DOE sponsored project ''Fundamental studies of ignition processes in large natural gas engines using laser spark ignition''. The goal of the overall research effort is to develop a laser ignition system for natural gas engines, with a particular focus on using fiber optic delivery methods.

Azer Yalin; Morgan Defoort; Bryan Willson

2005-01-01

69

FUNDAMENTAL PROCESSES INVOLVED IN SO2 CAPTURE BY CALCIUM-BASED ADSORBENTS  

EPA Science Inventory

The paper discusses the fundamental processes in sulfur dioxide (SO2) capture by calcium-based adsorbents for upper furnace, duct, and electrostatic precipitator (ESP) reaction sites. It examines the reactions in light of controlling mechanisms, effect of sorbent physical propert...

70

Electroporation of Cell Membranes: The Fundamental Effects of Pulsed Electric Fields in Food Processing  

Microsoft Academic Search

Using of pulsed electric fields (PEF) for killing of microorganisms in liquid foods is a promising new non-thermal food processing\\u000a and preservation technology. However, to implement and optimize this technology, a good understanding of the actual mechanisms\\u000a that govern microbial inactivation by this technique is required. Here, fundamentals of cell electroporation, which is considered\\u000a as underlying phenomenon of food processing

Gintautas Saulis

2010-01-01

71

Radiogenic Strontium-87 as an Index of Geologic Processes.  

PubMed

The abundance of radiogenic Sr(87) relative to Sr(86) at the time of crystallization has been determined for 45 rocks. The total range in the ratio Sr(87)/Sr(86) is less than 2 percent. Ratios for recent lavas range from 0.702 to 0.711. Oceanic basalts are closely grouped at 0.703, whereas ratios for continental volcanic rocks spread from 0.702 to 0.711. Among the volcanic rocks, ranging from basalt to rhyolite, no correlation was found between original ratio and rock type. Older mafic and felsic rocks that include both plutonic and extrusive types also cover this same range in original Sr(87)/Sr(86) ratios; however, there is a definite trend with geologic time. Precambrian rocks give values as low as 0.700. The data indicate that Sr(87)/Sr(86) of the weathering crust has changed 1.1 percent in 3000 million years, while the ratio in the mantle has changed no more than 0.5 percent. PMID:17837503

Hedge, C E; Walthall, F G

1963-06-14

72

Refining Martian Ages and Understanding Geological Processes From Cratering Statistics  

NASA Astrophysics Data System (ADS)

Senior Scientist William K. Hartman presents his final report on Mars Data Analysis Program grant number NAG5-12217: The third year of the three-year program was recently completed in mid-2005. The program has been extremely productive in research and data analysis regarding Mars, especially using Mars Global Surveyor and Mars Odyssey imagery. In the 2005 alone, three papers have already been published, to which this work contributed.1) Hartmann, W. K. 200.5. Martian cratering 8. Isochron refinement and the history of Martian geologic activity Icarus 174, 294-320. This paper is a summary of my entire program of establishing Martian chronology through counts of Martian impact craters. 2) Arfstrom, John, and W. K. Hartmann 2005. Martian flow features, moraine-like rieges, and gullies: Terrestrial analogs and interrelationships. Icarus 174,32 1-335. This paper makes pioneering connections between Martian glacier-like features and terrestrial glacial features. 3) Hartmann, W.K., D. Winterhalter, and J. Geiss. 2005 Chronology and Physical Evolution of Planet Mars. In The Solar System and Beyond: Ten Years of ISSI (Bern: International Space Science Institute). This is a summary of work conducted at the International Space Science Institute with an international team, emphasizing our publication of a conference volume about Mars, edited by Hartmann and published in 2001.

Hartmann, William K.

2005-01-01

73

Radiogenic strontium-87 as an index of geologic processes  

USGS Publications Warehouse

The abundance of radiogenic Sr87 relative to Sr86 at the time of crystallization has been determined for 45 rocks. The total range in the ratio Sr87/Sr86 is less than 2 percent. Ratios for recent lavas range from 0.702 to 0.711. Oceanic basalts are closely grouped at 0.703, whereas ratios for continental volcanic rocks spread from 0.702 to 0.711. Among the volcanic rocks, ranging from basalt to rhyolite, no correlation was found between original ratio and rock type. Older mafic and felsic rocks that include both plutonic and extrusive types also cover this same range in original Sr87/Sr86 ratios; however, there is a definite trend with geologic time. Pre-cambrian rocks give values as low as 0.700. The data indicate that Sr87/Sr86 of the weathering crust has changed 1.1 percent in 3000 million years, while the ratio in the mantle has changed no more than 0.5 percent.

Hedge, C.E.; Walthall, F.G.

1963-01-01

74

Feasibility Study for a Plasma Dynamo Facility to Investigate Fundamental Processes in Plasma Astrophysics. Final report  

SciTech Connect

The scientific equipment purchased on this grant was used on the Plasma Dynamo Prototype Experiment as part of Professor Forest's feasibility study for determining if it would be worthwhile to propose building a larger plasma physics experiment to investigate various fundamental processes in plasma astrophysics. The initial research on the Plasma Dynamo Prototype Experiment was successful so Professor Forest and Professor Ellen Zweibel at UW-Madison submitted an NSF Major Research Instrumentation proposal titled "ARRA MRI: Development of a Plasma Dynamo Facility for Experimental Investigations of Fundamental Processes in Plasma Astrophysics." They received funding for this project and the Plasma Dynamo Facility also known as the "Madison Plasma Dynamo Experiment" was constructed. This experiment achieved its first plasma in the fall of 2012 and U.S. Dept. of Energy Grant No. DE-SC0008709 "Experimental Studies of Plasma Dynamos," now supports the research.

Forest, Cary B.

2013-09-19

75

Frictional Sliding of Cold Ice: A Fundamental Process Underlying Tectonic Activity Within Icy Satellites  

NASA Astrophysics Data System (ADS)

Frictional sliding is a fundamental process underlying tectonic activity within the crusts of Enceladus, Europa and other icy satellites. Provided that the coefficient of friction is not too high, sliding can account for the generation of active plumes within Enceladus "tiger stripes" and for the development of certain fracture features on Europa. This paper reviews current knowledge of frictional sliding in water ice Ih, and then raises a number of questions relevant to tectonic modeling.

Schulson, Erland M.

76

Geological images  

NSDL National Science Digital Library

This site from Marli Bryant Miller, a professor at the University of Oregon, presents images of geological features from around the world. Photographs of glacial features, igneous and metamorphic rocks and processes, and structural geology are featured.

Marli Bryant Miller

77

Processing of Neutron Diffraction Data for Strain Measurement in Geological Materials  

SciTech Connect

: Conventional rock mechanics testing techniques typically involve the loading of samples and measurement of displacements or strains on the outer boundary of the specimen surface. Neutron diffraction based strain measurement techniques represent a unique and powerful tool for measuring the strain within geological materials under load. The structural variability and non-uniform crystallinity of geological materials, however, create many complexities in the intensity patterns that must be analyzed to quantify strains within the material. The attenuating and scattering properties of the pressure cell housing the sample further add difficulties to the data analysis. This paper describes the methods and processes used to process neutron scattering data for strain measurement in geological materials. It is intended to provide a primer for those in the rock mechanics community that are interested in utilizing this technique along with additional discussion of neutron diffraction experimental factors that may affect data quality.

Polsky, Yarom [ORNL] [ORNL; An, Ke [ORNL] [ORNL; Anovitz, Lawrence {Larry} M [ORNL; Bingham, Philip R [ORNL] [ORNL; Carmichael, Justin R [ORNL] [ORNL; Dessieux Jr, Luc Lucius [ORNL] [ORNL

2014-01-01

78

Fundamentals of High Pressure Combustion Chapter in High Pressure Processes in Chemical Engineering, Edited by Maximillian Lackner,  

E-print Network

Fundamentals of High Pressure Combustion Chapter in High Pressure Processes in Chemical Engineering of the following chapter is to present an overview of the fundamentals of combustion processes in high pressure experimental studies typically address fuel jets or atomizers issuing into high pressure chambers

Miller, Richard S.

79

On the fundamental processes in molecular electrical doping of organic semiconductors  

NASA Astrophysics Data System (ADS)

Integer electron transfer between organic semiconductors (OSCs) and strong donor/acceptor molecules has been regarded as the fundamental mechanism of molecular electrical doping. However, this process entails a number of consequences that are in conflict with well-established concepts of organic-semiconductor physics such as the charge-induced appearance of polaronic states within the fundamental gap of the OSC. Here, from the results of (time-dependent) density-functional theory calculations on prototypical OSC/dopant pairs, we derive a new and different picture for the mechanism of molecular electrical doping, which resolves these inconsistencies. Common doping-related observations are rationalized through intermolecular hybridization of OSC and dopant frontier molecular orbitals. Controlling the degree of this hybridization thus naturally emerges as a strategy for the design of improved molecular dopants in future high-performance organic electronic devices.

Heimel, Georg; Salzmann, Ingo; Koch, Norbert

2012-06-01

80

Disribution and interplay of geologic processes on Titan from Cassini radar data  

USGS Publications Warehouse

The Cassini Titan Radar Mapper is providing an unprecedented view of Titan's surface geology. Here we use Synthetic Aperture Radar (SAR) image swaths (Ta-T30) obtained from October 2004 to December 2007 to infer the geologic processes that have shaped Titan's surface. These SAR swaths cover about 20% of the surface, at a spatial resolution ranging from ~350 m to ~2 km. The SAR data are distributed over a wide latitudinal and longitudinal range, enabling some conclusions to be drawn about the global distribution of processes. They reveal a geologically complex surface that has been modified by all the major geologic processes seen on Earth - volcanism, tectonism, impact cratering, and erosion and deposition by fluvial and aeolian activity. In this paper, we map geomorphological units from SAR data and analyze their areal distribution and relative ages of modification in order to infer the geologic evolution of Titan's surface. We find that dunes and hummocky and mountainous terrains are more widespread than lakes, putative cryovolcanic features, mottled plains, and craters and crateriform structures that may be due to impact. Undifferentiated plains are the largest areal unit; their origin is uncertain. In terms of latitudinal distribution, dunes and hummocky and mountainous terrains are located mostly at low latitudes (less than 30 degrees), with no dunes being present above 60 degrees. Channels formed by fluvial activity are present at all latitudes, but lakes are at high latitudes only. Crateriform structures that may have been formed by impact appear to be uniformly distributed with latitude, but the well-preserved impact craters are all located at low latitudes, possibly indicating that more resurfacing has occurred at higher latitudes. Cryovolcanic features are not ubiquitous, and are mostly located between 30 degrees and 60 degrees north. We examine temporal relationships between units wherever possible, and conclude that aeolian and fluvial/pluvial/lacustrine processes are the most recent, while tectonic processes that led to the formation of mountains and Xanadu are likely the most ancient.

Lopes, R.M.C.; Stofan, E.R.; Peckyno, R.; Radebaugh, J.; Mitchell, K.L.; Mitri, G.; Wood, C.A.; Kirk, R.L.; Wall, S.D.; Lunine, J.I.; Hayes, A.; Lorenz, R.; Farr, T.; Wye, L.; Craig, J.; Ollerenshaw, R.J.; Janssen, M.; LeGall, A.; Paganelli, F.; West, R.; Stiles, B.; Callahan, P.; Anderson, Y.; Valora, P.; Soderblom, L.

2010-01-01

81

Distribution and interplay of geologic processes on Titan from Cassini radar data  

USGS Publications Warehouse

The Cassini Titan Radar Mapper is providing an unprecedented view of Titan's surface geology. Here we use Synthetic Aperture Radar (SAR) image swaths (Ta-T30) obtained from October 2004 to December 2007 to infer the geologic processes that have shaped Titan's surface. These SAR swaths cover about 20% of the surface, at a spatial resolution ranging from ???350 m to ???2 km. The SAR data are distributed over a wide latitudinal and longitudinal range, enabling some conclusions to be drawn about the global distribution of processes. They reveal a geologically complex surface that has been modified by all the major geologic processes seen on Earth - volcanism, tectonism, impact cratering, and erosion and deposition by fluvial and aeolian activity. In this paper, we map geomorphological units from SAR data and analyze their areal distribution and relative ages of modification in order to infer the geologic evolution of Titan's surface. We find that dunes and hummocky and mountainous terrains are more widespread than lakes, putative cryovolcanic features, mottled plains, and craters and crateriform structures that may be due to impact. Undifferentiated plains are the largest areal unit; their origin is uncertain. In terms of latitudinal distribution, dunes and hummocky and mountainous terrains are located mostly at low latitudes (less than 30??), with no dunes being present above 60??. Channels formed by fluvial activity are present at all latitudes, but lakes are at high latitudes only. Crateriform structures that may have been formed by impact appear to be uniformly distributed with latitude, but the well-preserved impact craters are all located at low latitudes, possibly indicating that more resurfacing has occurred at higher latitudes. Cryovolcanic features are not ubiquitous, and are mostly located between 30?? and 60?? north. We examine temporal relationships between units wherever possible, and conclude that aeolian and fluvial/pluvial/lacustrine processes are the most recent, while tectonic processes that led to the formation of mountains and Xanadu are likely the most ancient. ?? 2009 Elsevier Inc.

Lopes, R.M.C.; Stofan, E.R.; Peckyno, R.; Radebaugh, J.; Mitchell, K.L.; Mitri, G.; Wood, C.A.; Kirk, R.L.; Wall, S.D.; Lunine, J.I.; Hayes, A.; Lorenz, R.; Farr, T.; Wye, L.; Craig, J.; Ollerenshaw, R.J.; Janssen, M.; LeGall, A.; Paganelli, F.; West, R.; Stiles, B.; Callahan, P.; Anderson, Y.; Valora, P.; Soderblom, L.

2010-01-01

82

Distribution and interplay of geologic processes on Titan from Cassini radar data  

NASA Astrophysics Data System (ADS)

The Cassini Titan Radar Mapper is providing an unprecedented view of Titan's surface geology. Here we use Synthetic Aperture Radar (SAR) image swaths (Ta-T30) obtained from October 2004 to December 2007 to infer the geologic processes that have shaped Titan's surface. These SAR swaths cover about 20% of the surface, at a spatial resolution ranging from ˜350 m to ˜2 km. The SAR data are distributed over a wide latitudinal and longitudinal range, enabling some conclusions to be drawn about the global distribution of processes. They reveal a geologically complex surface that has been modified by all the major geologic processes seen on Earth - volcanism, tectonism, impact cratering, and erosion and deposition by fluvial and aeolian activity. In this paper, we map geomorphological units from SAR data and analyze their areal distribution and relative ages of modification in order to infer the geologic evolution of Titan's surface. We find that dunes and hummocky and mountainous terrains are more widespread than lakes, putative cryovolcanic features, mottled plains, and craters and crateriform structures that may be due to impact. Undifferentiated plains are the largest areal unit; their origin is uncertain. In terms of latitudinal distribution, dunes and hummocky and mountainous terrains are located mostly at low latitudes (less than 30°), with no dunes being present above 60°. Channels formed by fluvial activity are present at all latitudes, but lakes are at high latitudes only. Crateriform structures that may have been formed by impact appear to be uniformly distributed with latitude, but the well-preserved impact craters are all located at low latitudes, possibly indicating that more resurfacing has occurred at higher latitudes. Cryovolcanic features are not ubiquitous, and are mostly located between 30° and 60° north. We examine temporal relationships between units wherever possible, and conclude that aeolian and fluvial/pluvial/lacustrine processes are the most recent, while tectonic processes that led to the formation of mountains and Xanadu are likely the most ancient.

Lopes, R. M. C.; Stofan, E. R.; Peckyno, R.; Radebaugh, J.; Mitchell, K. L.; Mitri, G.; Wood, C. A.; Kirk, R. L.; Wall, S. D.; Lunine, J. I.; Hayes, A.; Lorenz, R.; Farr, T.; Wye, L.; Craig, J.; Ollerenshaw, R. J.; Janssen, M.; Legall, A.; Paganelli, F.; West, R.; Stiles, B.; Callahan, P.; Anderson, Y.; Valora, P.; Soderblom, L.; The Cassini Radar Team

2010-02-01

83

Final report of ''Fundamental Surface Reaction Mechanisms in Fluorocarbon Plasma-Based Processing''  

SciTech Connect

This report provides a summary of results obtained in research supported by contract ''Fundamental Surface Reaction Mechanisms in Fluorocarbon Plasma-Based Processing'' (Contract No. DE-FG0200ER54608). In this program we advanced significantly the scientific knowledge base on low pressure fluorocarbon plasmas used for patterning of dielectric films and for producing fluorocarbon coatings on substrates. We characterized important neutral and ionic gas phase species that are incident at the substrate, and the processes that occur at relevant surfaces in contact with the plasma. The work was performed through collaboration of research groups at three universities where significantly different, complementary tools for plasma and surface characterization, computer simulation of plasma and surface processes exist. Exchange of diagnostic tools and experimental verification of key results at collaborating institutions, both experimentally and by computer simulations, was an important component of the approach taken in this work.

Gottlieb S. Oehrlein; H. Anderson; J. Cecchi; D. Graves

2004-09-21

84

Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors  

NASA Astrophysics Data System (ADS)

An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

1994-11-01

85

Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors  

NASA Technical Reports Server (NTRS)

An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

1994-01-01

86

The fundamental role of fission during r-process nucleosynthesis in neutron star mergers  

NASA Astrophysics Data System (ADS)

The rapid neutron-capture process, or r-process, is known to be of fundamental importance for explaining the origin of approximately half of the A > 60 stable nuclei observed in nature. Despite important efforts, the astrophysical site of the r-process remains unidentified. Here we study r-process nucleosynthesis in a material that is dynamically ejected by tidal and pressure forces during the merging of binary neutron stars. r-process nucleosynthesis during the decompression is known to be largely insensitive to the detailed astrophysical conditions because of efficient fission recycling, producing a composition that closely follows the solar r-abundance distribution for nuclei with mass numbers A > 140. Due to the important role played by fission in such a scenario, the impact of fission is carefully analyzed. We consider different state-of-the-art global models for the determination of the fission paths, nuclear level densities at the fission saddle points and fission fragment distributions. Based on such models, the sensitivity of the calculated r-process abundance distribution is studied. The fission path is found to strongly affect the region of heavy nuclei responsible for the fission recycling, while the fission fragment distribution of nuclei along the A ? 278 isobars defines the abundance pattern of nuclei produced in the 110 ? A ? 170 region. The late capture of prompt fission neutrons is also shown to affect the abundance distribution, and in particular the shape of the third r-process peak around A ? 195.

Goriely, S.

2015-02-01

87

Infrared spectroscopy as a probe of fundamental processes in microelectronics: silicon wafer cleaning and bonding  

NASA Astrophysics Data System (ADS)

In this paper, we review our recent infrared studies of the fundamental physical and chemical processes occurring at the interface of bonded silicon wafers, as a function of surface preparation and annealing temperature. We present a brief overview of the practical aspects of silicon-wafer bonding and the techniques used to evaluate the interface integrity, which highlight the need for fundamental studies of the microscopic interface phenomena. Importantly, we show that the interface between two silicon wafers approximates an ideal spectroscopic environment, in that there is a 28-fold enhancement in the sensitivity to the normal component of the interface absorption over any other surface optical geometry. Furthermore, the interface region is almost infinitely stable at room temperature, but can exhibit partial pressures ranging from near vacuum to several atmospheres upon annealing. We present results for two distinct types of wafer bonding: hydrophobic (hydrogen-terminated) and hydrophilic (oxide-terminated), since the origin of the initial attraction between the opposing surfaces is quite different in the two cases. Specifically, we show that ideally hydrogen-terminated Si(111) surfaces come within a few Å, under the influence of a Van der Waals attraction, as evidenced by a pronounced perturbation of the isolated Si?H stretch mode. In contrast, the initial attraction between hydrophilic surfaces is via hydrogen bonding, which is mediated by the presence of 2-4 monolayers of water that are trapped at the interface upon room-temperature joining. We demonstrate that vibrational spectroscopy provides unprecedented mechanistic insight into the thermal evolution of the molecular interface, which necessarily has a profound influence on the bonding process. Throughout the paper, emphasis is given to the need for a wide variety of additional (fundamental) studies of the surface phenomena occurring in these novel, technologically important systems.

Weldon, M. K.; Marsico, V. E.; Chabal, Y. J.; Hamann, D. R.; Christman, S. B.; Chaban, E. E.

1996-12-01

88

Dependence of the triple-alpha process on the fundamental constants of nature  

E-print Network

We present an ab initio calculation of the quark mass dependence of the ground state energies of ^4He, ^8Be and ^{12}C, and of the energy of the Hoyle state in ^{12}C. These investigations are performed within the framework of lattice chiral Effective Field Theory. We address the sensitivity of the production rate of carbon and oxygen in red giant stars to the fundamental constants of nature by considering the impact of variations in the light quark masses and the electromagnetic fine-structure constant on the reaction rate of the triple-alpha process. As carbon and oxygen are essential to life as we know it, we also discuss the implications of our findings for an anthropic view of the Universe. We find strong evidence that the physics of the triple-alpha process is driven by alpha clustering, and that shifts in the fundamental parameters at the \\simeq 2 - 3 % level are unlikely to be detrimental to the development of life. Tolerance against much larger changes cannot be ruled out at present, given the relatively limited knowledge of the quark mass dependence of the two-nucleon S-wave scattering parameters. Lattice QCD is expected to provide refined estimates of the scattering parameters in the future.

Evgeny Epelbaum; Hermann Krebs; Timo A. Lähde; Dean Lee; Ulf-G. Meißner

2013-09-02

89

Dependence of the triple-alpha process on the fundamental constants of nature  

NASA Astrophysics Data System (ADS)

We present an ab initio calculation of the quark mass dependence of the ground state energies of 4He , 8Be and 12C , and of the energy of the Hoyle state in 12C . These investigations are performed within the framework of lattice chiral Effective Field Theory. We address the sensitivity of the production rate of carbon and oxygen in red giant stars to the fundamental constants of nature by considering the impact of variations in the light quark masses and the electromagnetic fine-structure constant on the reaction rate of the triple-alpha process. As carbon and oxygen are essential to life as we know it, we also discuss the implications of our findings for an anthropic view of the Universe. We find strong evidence that the physics of the triple-alpha process is driven by alpha clustering, and that shifts in the fundamental parameters at the ? 2-3% level are unlikely to be detrimental to the development of life. Tolerance against much larger changes cannot be ruled out at present, given the relatively limited knowledge of the quark mass dependence of the two-nucleon S -wave scattering parameters. Lattice QCD is expected to provide refined estimates of the scattering parameters in the future.

Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A.; Lee, Dean; Meißner, Ulf-G.

2013-07-01

90

Dependence of the triple-alpha process on the fundamental constants of nature  

E-print Network

We present an ab initio calculation of the quark mass dependence of the ground state energies of ^4He, ^8Be and ^{12}C, and of the energy of the Hoyle state in ^{12}C. These investigations are performed within the framework of lattice chiral Effective Field Theory. We address the sensitivity of the production rate of carbon and oxygen in red giant stars to the fundamental constants of nature by considering the impact of variations in the light quark masses and the electromagnetic fine-structure constant on the reaction rate of the triple-alpha process. As carbon and oxygen are essential to life as we know it, we also discuss the implications of our findings for an anthropic view of the Universe. We find strong evidence that the physics of the triple-alpha process is driven by alpha clustering, and that shifts in the fundamental parameters at the \\simeq 2 - 3 % level are unlikely to be detrimental to the development of life. Tolerance against much larger changes cannot be ruled out at present, given the relati...

Epelbaum, Evgeny; Lähde, Timo A; Lee, Dean; Meißner, Ulf-G

2013-01-01

91

Hometown Geology  

NSDL National Science Digital Library

Students are introduced to concepts in the course that give them the skills to understand geologic maps. These include structural geology, weathering processes, the geologic time scale, types of rocks and minerals, glacial geology, etc. They also look at several quadrangle maps as lab activities, including the Williamsville Quadrangle from Virginia and the Bright Angel Quadrangle from the Grand Canyon. This independent exercise allows students to further investigate their hometown or other areas of interest, and report on the geologic history. This further prepares them for more advanced courses and also gives them an appreciation of their surroundings, a key part of a geologist's training.

Stacey Cochiara

92

Understanding Fundamental Material Degradation Processes in High Temperature Aggressive Chemomechanical Environments  

SciTech Connect

The objective of this project is to develop a fundamental understanding of the mechanisms that limit materials durability for very high-temperature applications. Current design limitations are based on material strength and corrosion resistance. This project will characterize the interactions of high-temperature creep, fatigue, and environmental attack in structural metallic alloys of interest for the very high-temperature gas-cooled reactor (VHTR) or Next–Generation Nuclear Plant (NGNP) and for the associated thermo-chemical processing systems for hydrogen generation. Each of these degradation processes presents a major materials design challenge on its own, but in combination, they can act synergistically to rapidly degrade materials and limit component lives. This research and development effort will provide experimental results to characterize creep-fatigue-environment interactions and develop predictive models to define operation limits for high-temperature structural material applications. Researchers will study individually and in combination creep-fatigue-environmental attack processes in Alloys 617, 230, and 800H, as well as in an advanced Ni-Cr oxide dispersion strengthened steel (ODS) system. For comparison, the study will also examine basic degradation processes in nichrome (Ni-20Cr), which is a basis for most high-temperature structural materials, as well as many of the superalloys. These materials are selected to represent primary candidate alloys, one advanced developmental alloy that may have superior high-temperature durability, and one model system on which basic performance and modeling efforts can be based. The research program is presented in four parts, which all complement each other. The first three are primarily experimental in nature, and the last will tie the work together in a coordinated modeling effort. The sections are 1) dynamic creep-fatigue-environment process, 2) subcritical crack processes, 3) dynamic corrosion – crack initiation processes, and 4) modeling.

Stubbins, James; Gewirth, Andrew; Sehitoglu, Huseyin; Sofronis, Petros; Robertson, Ian

2014-01-16

93

FUNDAMENTAL STUDIES OF IGNITION PROCESSES IN LARGE NATURAL GAS ENGINES USING LASER SPARK IGNITION  

SciTech Connect

The current report details project progress made during the first quarterly reporting period of the DOE sponsored project ''Fundamental studies of ignition processes in large natural gas engines using laser spark ignition''. The goal of the overall research effort is to develop a laser ignition system for natural gas engines, with a particular focus on using fiber optic delivery methods. In this report we present our successful demonstration of spark formation using fiber delivery made possible though the use of novel coated hollow fibers. We present results of (high power) experimental characterizations of light propagation using hollow fibers using both a high power research grade laser as well as a more compact laser. Finally, we present initial designs of the system we are developing for future on-engine testing using the hollow fibers.

Azer Yalin; Morgan Defoort; Bryan Willson

2005-01-01

94

Investigations on Plasma-Biomolecules Interactions as Fundamental Process for Plasma Medicine  

NASA Astrophysics Data System (ADS)

Investigations on plasma-biomolecules interactions have been carried out as fundamental process for plasma applications in medical science and biological treatments. In this study, plasma interactions with L-alanine which are amino acids: the building blocks of proteins have been investigated in terms of physical effects. Effect of ion and photon irradiation on degradation of L-alanine has been studied via x-ray photoelectron spectroscopy (XPS) analysis of chemical bonding states. The XPS results showed that the decrease in the -CH3 bond, >C(NH2)COOH bond, and -COOH bond peaks of main component of the L-alanine with increasing ion energy, ion dose and photon energy. The L-alanine degraded by ions and photons with energy over 6eV.

Takenaka, Kosuke; Cho, Ken; Setsuhara, Yuichi; Shiratani, Masaharu; Sekine, Makoto; Hori, Masaru

2013-06-01

95

Martian planetwide crater distributions - Implications for geologic history and surface processes  

NASA Technical Reports Server (NTRS)

Three different diameter size ranges are considered in connection with the Martian crater distribution, taking into account small craters from 0.6 to 1.2 km, intermediate-sized craters from 4 to 10 km, and large craters with diameters exceeding 20 km. One of the objectives of the investigation reported is to establish the effects of eolian processes in the modification of craters in the different size ranges. Another objective is concerned with a description of the genetic relationships among the three size ranges of craters. Observables related to the relative age of geologic provinces are to be separated from observables related to geographic variations in eolian transport and deposition. Lunar and Martian cratering histories are compared as a basis for establishing relative and absolute time scales for the geological evolution of Mars.

Soderblom, L. A.; Condit, C. D.; West, R. A.; Herman, B. M.; Kreidler, T. J.

1974-01-01

96

Geologic Maps Geology 200  

E-print Network

Geologic Maps Geology 200 Geology for Environmental Scientists #12;Geologic Map of the US #12;Symbols found on geologic maps #12;Horizontal Strata #12;Geologic map of part of the Grand Canyon. Each color represents a different formation. #12;Inclined Strata #12;Dome #12;Geologic map of the Black Hills

Kammer, Thomas

97

Quaternary geology and geomorphology of the Sacramento-San Joaquin Delta, California: evolution and processes  

NASA Astrophysics Data System (ADS)

The Sacramento-San Joaquin Delta (~1,400 km2) is a combination of tidal marsh, islands and agricultural lands at the confluence of the Sacramento and the San Joaquin Rivers, in northern California. Most of the Delta islands are now 3 to 8 m below sea-level and must be protected by levees from inundation. Because of the Delta's crucial role in conveying fresh water to the State, levee failures can cause substantial economic loss by disrupting this supply. Understanding the evolution of the Delta is fundamental to assess the vulnerability of the Delta islands to seismically-induced levee failure. The modern Delta is a young geological feature that began forming during the middle Holocene. Preceding versions of the Delta hosted a variety of depositional environments as sea level fluctuated, responding to climatically-controlled changes. The rising sea reached the Delta about 8,000 years ago, and modern deltaic evolution continued into Holocene time until present. More accurate stratigraphic studies incorporating depositional ages are required to i) better understand the late Quaternary evolution of the Delta, ii) trace the base of Holocene deposits, iii) identify potentially active faults, and iv) evaluate liquefaction hazard for the Delta . This study uses the large amount of data available on the Delta (collected by the California Department of Water Resources and others during the past 30 years) and merges them into a unified dataset. We have produced a database that includes historic and surficial maps, aerial photographs, boreholes, and CPT data, for the purpose of clarifying the nature of the Quaternary deposits and the evolution of the Late Quaternary Delta. Additionally, we have identified recently discovered Pleistocene tephra as the Rockland ash, ~0.575 Ma, and the Loleta ash, ~0.40-0.37 Ma, which have improved stratigraphic correlations and assessment of subsidence rates. Delta sediments include sequences of glacial and interglacial deposits. Borehole logs reveal sequences of incision and backfilling corresponding to major climatic fluctuations: incised channels, sand-filling channels, gravel alluvial fans and eolian dunes during glacial periods, and fine-grained alluvial floodplains, mud flats deposits, marshes and peat during warmer interglacials. The evolution of the Delta is likely the result of three processes: subsidence (based on tephra ages, between ~0.004 cm/yr and 0.007 cm/yr in the Northern Delta, ~0.01 cm/yr in the central Delta, ~0.06 cm/yr in the Eastern Delta), compaction due to organic soil oxidation (3.6-6.1 cm/yr), and tectonic control. The thickness of the organic soils (>20 m) suggests that the Holocene sea-level rise was the major factor controlling the Delta's morphology before agricultural drainage began in the 1850's. Because the patterns suggest that sea-level rise was the major cause of changes in the Delta, it is likely that once the organic soil is all oxidized by anthropogenic processes within a few centuries, the major controlling factor will become anthropogenic sea-level rise.

Gatti, E.; Maier, K. L.; Holzer, T. L.; Knudsen, K. L.; Olson, H.; Pagenknopp, M.; Ponti, D. J.; Rosa, C.; Tinsley, J. C.; Wan, E.

2013-12-01

98

Fundamental and Technological Limitations in Optical Processing and Computing: Algorithms, Architectures, and Devices.  

NASA Astrophysics Data System (ADS)

Existing electronic computers are reaching technological barriers that limit their speed and processing capacity. For particular classes of problems, an alternative to digital computation is provided by multidimensional optical components in both all-optical and hybrid electronic/optical architectures. The advantages of such processors come from the inherent parallelism available in optical systems and the relative ease of implementation of analog interconnections. The goal of this investigation is twofold: to examine the physical and technological limitations that pertain to issues of representation, detection of information, and manipulation of intermediate results in such optical analog processors; and to demonstrate that such processors offer the potential of computation much closer to the fundamental boundaries than their digital counterparts. Using energy as a metric with which to assess the overall cost of computation, we examine the fundamental requirements imposed by an analog data representation. Our results show that analog schemes require far more energy than the binary equivalent to maintain the same levels of accuracy. This is due to the necessity of utilizing a much higher particle count in order to minimize the effects of photon number fluctuations on the bit error rate (BER). However, when we also consider computational complexity we find that analog systems can have a competitive advantage. In fact, a fundamental trade-off between accuracy and computational complexity exists that is investigated in detail. In the second part of this work we critically examine a component that plays a key role in the implementation of analog optical processors: spatial light modulators (SLM's). The assessment of the current status of spatial light modulator development depends strongly on the nature of the application and its requirements. We have chosen the class of asymmetric cavity multiple quantum well (MQW) SLMs because of their potential for implementation of analog data representations, and hybridization with electronic control circuitry on silicon substrates. In this work we determine the limitations of the performance characteristics of these devices both as amplitude and as phase modulators, and explore the possibilities of mixed configurations. (Copies available exclusively from Micrographics Department, Doheny Library, USC, Los Angeles, CA 90089-0182).

Kyriakakis, Christos

99

Geodynamics applications of continuum physics to geological problems  

Microsoft Academic Search

This textbook deals with the fundamental physical processes necessary for an understanding of plate tectonics and a variety of geologic phenomena. The first chapter reviews plate tectonics; its main purpose is to provide physics, chemistry, and engineering students with the geologic background necessary to understand the applications throughout the rest of the book. It goes on to discuss in following

D. L. Turcotte; G. Schubert

1982-01-01

100

Chemical Sensing for Buried Landmines - Fundamental Processes Influencing Trace Chemical Detection  

SciTech Connect

Mine detection dogs have a demonstrated capability to locate hidden objects by trace chemical detection. Because of this capability, demining activities frequently employ mine detection dogs to locate individual buried landmines or for area reduction. The conditions appropriate for use of mine detection dogs are only beginning to emerge through diligent research that combines dog selection/training, the environmental conditions that impact landmine signature chemical vapors, and vapor sensing performance capability and reliability. This report seeks to address the fundamental soil-chemical interactions, driven by local weather history, that influence the availability of chemical for trace chemical detection. The processes evaluated include: landmine chemical emissions to the soil, chemical distribution in soils, chemical degradation in soils, and weather and chemical transport in soils. Simulation modeling is presented as a method to evaluate the complex interdependencies among these various processes and to establish conditions appropriate for trace chemical detection. Results from chemical analyses on soil samples obtained adjacent to landmines are presented and demonstrate the ultra-trace nature of these residues. Lastly, initial measurements of the vapor sensing performance of mine detection dogs demonstrates the extreme sensitivity of dogs in sensing landmine signature chemicals; however, reliability at these ultra-trace vapor concentrations still needs to be determined. Through this compilation, additional work is suggested that will fill in data gaps to improve the utility of trace chemical detection.

PHELAN, JAMES M.

2002-05-01

101

Canada's Deep Geological Repository for Used Nuclear Fuel - Geo-scientific Site Evaluation Process - 13117  

SciTech Connect

The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable rock formation at a depth of approximately 500 meters (m) (1,640 feet [ft]). In May 2010, the NWMO published a nine-step site selection process that serves as the road map to decision-making on the location for the deep geological repository. The safety and appropriateness of any potential site will be assessed against a number of factors, both technical and social in nature. The selected site will be one that can be demonstrated to be able to safely contain and isolate used nuclear fuel, protecting humans and the environment over the very long term. The geo-scientific suitability of potential candidate sites will be assessed in a stepwise manner following a progressive and thorough site evaluation process that addresses a series of geo-scientific factors revolving around five safety functions. The geo-scientific site evaluation process includes: Initial Screenings; Preliminary Assessments; and Detailed Site Evaluations. As of November 2012, 22 communities have entered the site selection process (three in northern Saskatchewan and 18 in northwestern and southwestern Ontario). (authors)

Blyth, Alec; Ben Belfadhel, Mahrez; Hirschorn, Sarah; Hamilton, Duncan; McKelvie, Jennifer [Nuclear Waste Management Organization, 22 St. Clair Avenue East, Toronto, Ontario M4T 2S3 (Canada)] [Nuclear Waste Management Organization, 22 St. Clair Avenue East, Toronto, Ontario M4T 2S3 (Canada)

2013-07-01

102

Fundamental Study on the Dynamics of Heterogeneity-Enhanced CO2 Gas Evolution in the Shallow Subsurface During Possible Leakage from Deep Geologic Storage Sites  

NASA Astrophysics Data System (ADS)

A concern for geologic carbon sequestration is the potential for CO2 stored in deep geologic formations to leak upward into shallow freshwater aquifers where it can have potentially detrimental impacts to the environment and human health. Understanding the mechanisms of CO2 exsolution, migration and accumulation (collectively referred to as 'gas evolution') in the shallow subsurface is critical to predict and mitigate the environmental impacts. During leakage, CO2 can move either as free-phase or as a dissolved component of formation brine. CO2 dissolved in brine may travel upward into shallow freshwater systems, and the gas may be released from solution. In the shallow aquifer, the exsolved gas may accumulate near interfaces between soil types, and/or create flow paths that allow the gas to escape through the vadose zone to the atmosphere. The process of gas evolution in the shallow subsurface is controlled by various factors, including temperature, dissolved CO2 concentration, water pressure, background water flow rate, and geologic heterogeneity. However, the conditions under which heterogeneity controls gas phase evolution have not yet been precisely defined and can therefore not yet be incorporated into models used for environmental risk assessment. The primary goal of this study is to conduct controlled laboratory experiments to help fill this knowledge gap. With this as a goal, a series of intermediate-scale laboratory experiments were conducted to observe CO2 gas evolution in porous media at multiple scales. Deionized water was saturated with dissolved CO2 gas under a specified pressure (the saturation pressure) before being injected at a constant volumetric flow rate into the bottom of a 1.7 meter-tall by 5.7 centimeter-diameter column or a 2.4 meter-tall by 40 centimeter-wide column that were both filled with sand in various heterogeneous packing configurations. Both test systems were initially saturated with fresh water and instrumented with soil moisture sensors to monitor the evolution of gas phase through time by measuring the average water content in small sampling volumes of soil. Tensiometers allowed for observation of water pressure through space and time in the test systems, and a computer-interfaced electronic scale continuously monitored the outflow of water from the top of the two test columns. Several packing configurations with five different types of sands were used in order to test the effects of various pore size contrasts and interface shapes on the evolution of the gas phase near soil texture transitions in the heterogeneous packings. Results indicate that: (1) heterogeneity affects gas phase evolution patterns within a predictable range of conditions quantified by the newly introduced term 'oversaturation,' (2) soil transition interfaces where less permeable material overlies more permeable material have a much more pronounced effect on gas evolution than interfaces with opposite orientations, and (3) anticlines (or stratigraphic traps) cause significantly greater gas accumulation than horizontal interfaces. Further work is underway to apply these findings to more realistic, two-dimensional scenarios, and to assess how well existing numerical models can capture these processes.

Plampin, M. R.; Lassen, R. N.; Sakaki, T.; Pawar, R.; Jensen, K.; Illangasekare, T. H.

2013-12-01

103

The Magnetospheric Multiscale Mission...Resolving Fundamental Processes in Space Plasmas  

NASA Technical Reports Server (NTRS)

The Magnetospheric Multiscale (MMS) mission is a multiple-spacecraft Solar-Terrestrial Probe designed to study the microphysics of magnetic reconnection, charged particle acceleration, and turbulence in key boundary regions of Earth's magnetosphere. These three processes, which control the flow of energy, mass, and momentum within and across plasma boundaries, occur throughout the universe and are fundamental to our understanding of astrophysical and solar system plasmas. Only in Earth's magnetosphere, however, are they readily accessible for sustained study through in-situ measurement. MMS will employ five co-orbiting spacecraft identically instrumented to measure electric and magnetic fields, plasmas, and energetic particles. The initial parameters of the individual spacecraft orbits will be designed so that the spacecraft formation will evolve into a three-dimensional configuration near apogee, allowing MMS to differentiate between spatial and temporal effects and to determine the three dimensional geometry of plasma, field, and current structures. In order to sample all of the magnetospheric boundary regions, MMS will employ a unique four-phase orbital strategy involving carefully sequenced changes in the local time and radial distance of apogee and, in the third phase, a change in orbit inclination from 10 degrees to 90 degrees. The nominal mission operational lifetime is two years. Launch is currently scheduled for 2006.

Curtis, S.

1999-01-01

104

Processes that initiate turbidity currents and their influence on turbidites: A marine geology perspective  

USGS Publications Warehouse

How the processes that initiate turbidity currents influence turbidite deposition is poorly understood, and many discussions in the literature rely on concepts that are overly simplistic. Marine geological studies provide information on the initiation and flow path of turbidity currents, including their response to gradient. In case studies of late Quaternary turbidites on the eastern Canadian and western U.S. margins, initiation processes are inferred either from real-time data for historical flows or indirectly from the age and contemporary paleogeography, erosional features, and depositional record. Three major types of initiation process are recognized: transformation of failed sediment, hyperpycnal flow from rivers or ice margins, and resuspension of sediment near the shelf edge by oceanographic processes. Many high-concentration flows result from hyperpycnal supply of hyperconcentrated bedload, or liquefaction failure of coarse-grained sediment, and most tend to deposit in slope conduits and on gradients < 0.5?? at the base of slope and on the mid fan. Highly turbulent flows, from transformation of retrogressive failures and from ignitive flows that are triggered by oceanographic processes, tend to cannibalize these more proximal sediments and redeposit them on lower gradients on the basin plain. Such conduit flushing provides most of the sediment in large turbidites. Initiation mechanism exerts a strong control on the duration of turbidity flows. In most basins, there is a complex feedback between different types of turbidity-current initiation, the transformation of the flows, and the associated slope morphology. As a result, there is no simple relationship between initiating process and type of deposit. ?? 2009, SEPM (Society for Sedimentary Geology).

Piper, David J.W.; Normark, William R.

2009-01-01

105

Exploring Geology  

NASA Astrophysics Data System (ADS)

I am willing to bet a nice bottle of chardonnay that much of the Eos readership has lugged around, fondled, and fumbled through an introductory physical geology textbook of some form or another, once upon a time. Mine, in 1970, was Physical Geology, by Longwell, Flint, and Sanders, which I still have, by the way. Most of us know how ``classical'' physical geology textbooks have been organized: first, a broad overview of Earth processes, then several sections devoted to groups of more specific subjects (e.g., mineralogy, sedimentary rocks, and environments, with one chapter per subject), then several sections devoted to a synthesis of geologic processes in the context of plate tectonics, and finally, typically, a discussion of Earth resources and environment- related issues. Some relatively new textbooks have ventured into new pedagogical formats, for example, emphasizing how we know what we know (e.g., How Does Earth Work: Physical Geology and the Process of Science by Smith and Pun).

Geissman, John W.

2008-09-01

106

Physical geology  

SciTech Connect

The book integrates current thinking on processes (plate techtonics, chemical cycles, changes throughout geologic time). It is an introduction to investigations into the way the earth works, how mountains are formed, how the atmosphere, hydrosphere, crust and mantle interact with each other. Treatments on climate, paleoclimatology and landscape evolution are included, as is a discussion on how human activity affects geological interactions.

Skinner, B.; Porter, S.

1987-01-01

107

No geology without marine geology  

Microsoft Academic Search

A brief review is offered of the many problems where knowledge of the ocean floors and of marine processes in shallow water is indispensable for the further advancement of geology. The subject of turbidity currents is treated in greater detail, to demonstrate the interrelation of several aspects of marine geology with sedimentologic and paleogeographic investigations. It is obvious that the

P. H Kuenen

2002-01-01

108

Quantitative Geological Surface Processes Extracted From Infrared Spectroscopy and Remote Sensing  

NSDL National Science Digital Library

This 17-page PDF document from Michael Ramsey at the University of Pittsburg explores some of the practical applications of Thermal Infrared (TIR) data in both the laboratory and remotely acquired environments. It focuses on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) in particular, but also mentions other systems and the caveats of moving from laboratory-based hypotheses to real world data. The document discusses the principles of TIR, highlighting the common analytical technique of spectral deconvolution as it is applied to two very different geologic processes. Case studies at the Kelso Dunes, CA and Bezimmiany Volcano, Russia, are used as primary examples that highlight TIR applications to eolian and volcanological processes. Graphs and photos help illustrate the concepts.

Michael S. Ramsey

109

Geoelectrical signals of geologic and hydrologic processes in a fringing reef lagoon setting  

NASA Astrophysics Data System (ADS)

Coastal groundwater may discharge into nearshore and offshore waters forced by terrestrial fluxes, controlled by local geology, and modulated by the hydrodynamics of littoral water. We investigated the electrical signature of these features with a dense, multiscale network of electrical resistivity tomography (ERT) surveys in the Muri Lagoon of Rarotonga, Cook Islands. The ERT surveys spanned from onshore to 400 m into the lagoon and used standard electrodes on land and across the foreshore, submerged electrodes in the shallow subtidal zone, and floating electrodes towed throughout the reef lagoon by a boat. ERT surveys on land mapped a typical freshwater lens underlain by a saltwater wedge, but with possible deviations from the classical model due to an adjacent tidal creek. Further inland, ERT surveys imaged a layer of lava flow deposits that is potentially a confining hydrogeologic unit; this unit was used to constrain the expected electrical resistivity of these deposits below the lagoon. ERT surveys across the intertidal zone and into the lagoon indicated fresh groundwater and porewater salinity patterns consistent with previous small-scale studies including the seaward extension of fresh groundwater pathways to the lagoon. Electrical resistivity (ER) variations in the lagoon subsurface highlighted heterogeneities in the lagoon structure that may focus submarine groundwater discharge (SGD) through previously unknown buried lava flow deposits in the lagoon. A transition to higher ER values near the reef crest is consistent with the ER signature of porosity reduction due to ongoing differential cementation of reef deposits across the lagoon. The imaged coastal hydrostratigraphic heterogeneity may thus control terrestrial and marine porewater mixing, support SGD, and provide the pathways for groundwater and the materials it transports into the lagoon. This hydrogeophysical investigation highlighted the spatial heterogeneity of submarine coastal geology and its hydrogeologic control in a reef lagoon setting, but is likely to occur in many similar coastal settings. Ignoring geologic complexity can result in mischaracterization of SGD and other coastal groundwater processes at many spatial scales.

Befus, Kevin M.; Cardenas, M. Bayani; Tait, Douglas R.; Erler, Dirk V.

2014-09-01

110

Laboratory Study of Fundamental Plasma Processes in Astrophysics: Progress and Opportunities  

NASA Astrophysics Data System (ADS)

Advances in astrophysics (including heliophysics) are led by new observations from recent satellites and ground-based observatories, revealing detailed plasma dynamics ranging from Earth's magnetospheric activity, solar wind turbulence, solar/stellar flares, gamma ray bursts, efficient energy release from hot accretion disks, to cosmic rays at highest energies. Many of these phenomena are surprising and demand better understanding. Motivated by these astrophysical observations, a large number of laboratory experiments, equipped by significant progress in controls, diagnostics, and numerical simulations, have been performed to study underlying fundamental plasma physics. This talk is intended to highlight recent achievements on the following three selected topics. (1) On the topic of magnetic reconnection,footnotetextM. Yamada, R. Kulsrud, and H. Ji, Magnetic Reconnection,'' Rev. Mod. Phys. 82 (2010) 603. which is considered to be responsible for rapid release of magnetic energy in astrophysics, the classical Sweet-Parker model has been tested successfully in collisional laboratory plasmas while two-fluid effects, including detailed electron-scale dynamics, are observed to be essential for fast reconnection. (2) On the topic of flow stability,footnotetextH. Ji, Current Status and Future Prospects for Laboratory Study of Angular Momentum Transport Relevant to Astrophysical Disks,'' Advances in Plasma Astrophysics, Proc. IAU Symp. #274, Sicily Island, Italy (2010) p.18. which is considered to govern accretion processes and turbulent mixing in highly dynamic astrophysical plasmas, a major candidate hydrodynamic instability of Keplerian flows has been effectively eliminated by laboratory experiments while the magnetic field effects on the flow stabilities are explored and quantified. (3) On the topic of shock waves, which are considered to be a generic mechanism for the observed particle heating and acceleration, laboratory experiments have successfully produced the shocks dominated by radiative processes, and experiments on generation of collisionless shocks are underway. Dynamic behaviors of the shock front consisting of fine structures are measured and quantitatively compared with the state-of-the-art numerical predictions. The bright future of this growing field will be reflected in discussions of several near term major scientific opportunities, highlighted from the report of a community-based Workshop on Opportunities in Plasma Astrophysics (WOPA).footnotetexthttp://www.pppl.gov/conferences/2010/WOPA

Ji, Hantao

2012-10-01

111

Fundamental limitations of non-thermal plasma processing for internal combustion engine NO{sub x} control  

SciTech Connect

This paper discusses the physics and chemistry of non-thermal plasma processing for post-combustion NO{sub x} control in internal combustion engines. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NO{sub x} removal mechanisms, and by product formation. Can non-thermal deNO{sub x} operate efficiently without additives or catalysts? How much electrical power does it cost to operate? What are the by-products of the process? This paper addresses these fundamental issues based on an analysis of the electron-molecule processes and chemical kinetics.

Penetrante, B.M.

1993-08-19

112

Improved understanding of geologic CO{sub 2} storage processes requires risk-driven field experiments  

SciTech Connect

The need for risk-driven field experiments for CO{sub 2} geologic storage processes to complement ongoing pilot-scale demonstrations is discussed. These risk-driven field experiments would be aimed at understanding the circumstances under which things can go wrong with a CO{sub 2} capture and storage (CCS) project and cause it to fail, as distinguished from accomplishing this end using demonstration and industrial scale sites. Such risk-driven tests would complement risk-assessment efforts that have already been carried out by providing opportunities to validate risk models. In addition to experimenting with high-risk scenarios, these controlled field experiments could help validate monitoring approaches to improve performance assessment and guide development of mitigation strategies.

Oldenburg, C.M.

2011-06-01

113

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

SciTech Connect

Above-boiling temperature conditions, as encountered, for example, in geothermal reservoirs and in geologic repositories for the storage of heat-producing nuclear wastes, may give rise to strongly altered liquid and gas flow processes in porous subsurface environments. The magnitude of such flow perturbation is extremely hard to measure in the field. We therefore propose a simple temperature-profile method that uses high-resolution temperature data for deriving such information. The energy that is transmitted with the vapor and water flow creates a nearly isothermal zone maintained at about the boiling temperature, referred to as a heat pipe. Characteristic features of measured temperature profiles, such as the differences in the gradients inside and outside of the heat pipe regions, are used to derive the approximate magnitude of the liquid and gas fluxes in the subsurface, for both steady-state and transient conditions.

J.T. Birkholzer

2005-01-21

114

Separating Macroecological Pattern and Process: Comparing Ecological, Economic, and Geological Systems  

PubMed Central

Theories of biodiversity rest on several macroecological patterns describing the relationship between species abundance and diversity. A central problem is that all theories make similar predictions for these patterns despite disparate assumptions. A troubling implication is that these patterns may not reflect anything unique about organizational principles of biology or the functioning of ecological systems. To test this, we analyze five datasets from ecological, economic, and geological systems that describe the distribution of objects across categories in the United States. At the level of functional form (‘first-order effects’), these patterns are not unique to ecological systems, indicating they may reveal little about biological process. However, we show that mechanism can be better revealed in the scale-dependency of first-order patterns (‘second-order effects’). These results provide a roadmap for biodiversity theory to move beyond traditional patterns, and also suggest ways in which macroecological theory can constrain the dynamics of economic systems. PMID:25383874

Blonder, Benjamin; Sloat, Lindsey; Enquist, Brian J.; McGill, Brian

2014-01-01

115

Separating macroecological pattern and process: comparing ecological, economic, and geological systems.  

PubMed

Theories of biodiversity rest on several macroecological patterns describing the relationship between species abundance and diversity. A central problem is that all theories make similar predictions for these patterns despite disparate assumptions. A troubling implication is that these patterns may not reflect anything unique about organizational principles of biology or the functioning of ecological systems. To test this, we analyze five datasets from ecological, economic, and geological systems that describe the distribution of objects across categories in the United States. At the level of functional form ('first-order effects'), these patterns are not unique to ecological systems, indicating they may reveal little about biological process. However, we show that mechanism can be better revealed in the scale-dependency of first-order patterns ('second-order effects'). These results provide a roadmap for biodiversity theory to move beyond traditional patterns, and also suggest ways in which macroecological theory can constrain the dynamics of economic systems. PMID:25383874

Blonder, Benjamin; Sloat, Lindsey; Enquist, Brian J; McGill, Brian

2014-01-01

116

Fundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic Radiation Energy is the ability to do work. In the process of doing work, energy is often transferred  

E-print Network

Fundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic of air in the atmosphere in the early afternoon. · The transfer of energy by electromagnetic radiation of energy by electromagnetic radiation is of primary interest to remote sensing because it is the only form

117

[Fundamental electron transfer processes at the single crystal semiconductor/liquid interface]. Progress report  

SciTech Connect

The last year`s work has focused on several aspects of the fundamental chemistry and physics semiconductor/liquid junction behavior. These projects have been directed primarily towards GaAs/liquid contacts, because GaAs/liquid systems provide high energy conversion efficiencies and offer an opportunity to gain mechanistic understanding of the factors that are important to control in an efficient photoelectrochemical energy conversion system.

Lewis, N.S.

1991-12-31

118

(Fundamental electron transfer processes at the single crystal semiconductor/liquid interface)  

SciTech Connect

The last year's work has focused on several aspects of the fundamental chemistry and physics semiconductor/liquid junction behavior. These projects have been directed primarily towards GaAs/liquid contacts, because GaAs/liquid systems provide high energy conversion efficiencies and offer an opportunity to gain mechanistic understanding of the factors that are important to control in an efficient photoelectrochemical energy conversion system.

Lewis, N.S.

1991-01-01

119

Assessment of effectiveness of geologic isolation systems. Geologic factors in the isolation of nuclear waste: evaluation of long-term geomorphic processes and catastrophic events  

SciTech Connect

SRI International has projected the rate, duration, and magnitude of geomorphic processes and events in the Southwest and Gulf Coast over the next million years. This information will be used by the Department of Energy`s Pacific Northwest Laboratory (PNL) as input to a computer model, which will be used to simulate possible release scenarios and the consequences of the release of nuclear waste from geologic containment. The estimates in this report, although based on best scientific judgment, are subject to considerable uncertainty. An evaluation of the Quaternary history of the two study areas revealed that each had undergone geomorphic change in the last one million years. Catastrophic events were evaluated in order to determine their significance to the simulation model. Given available data, catastrophic floods are not expected to occur in the two study areas. Catastrophic landslides may occur in the Southwest, but because the duration of the event is brief and the amount of material moved is small in comparison to regional denudation, such events need not be included in the simulation model. Ashfalls, however, could result in removal of vegetation from the landscape, thereby causing significant increases in erosion rates. Because the estimates developed during this study may not be applicable to specific sites, general equations were presented as a first step in refining the analysis. These equations identify the general relationships among the important variables and suggest those areas of concern for which further data are required. If the current model indicates that geomorphic processes (taken together with other geologic changes) may ultimately affect the geologic containment of nuclear waste, further research may be necessary to refine this analysis for application to specific sites.

Mara, S.J.

1980-03-01

120

Fundamental ecology is fundamental.  

PubMed

The primary reasons for conducting fundamental research are satisfying curiosity, acquiring knowledge, and achieving understanding. Here we develop why we believe it is essential to promote basic ecological research, despite increased impetus for ecologists to conduct and present their research in the light of potential applications. This includes the understanding of our environment, for intellectual, economical, social, and political reasons, and as a major source of innovation. We contend that we should focus less on short-term, objective-driven research and more on creativity and exploratory analyses, quantitatively estimate the benefits of fundamental research for society, and better explain the nature and importance of fundamental ecology to students, politicians, decision makers, and the general public. Our perspective and underlying arguments should also apply to evolutionary biology and to many of the other biological and physical sciences. PMID:25481619

Courchamp, Franck; Dunne, Jennifer A; Le Maho, Yvon; May, Robert M; Thébaud, Christophe; Hochberg, Michael E

2015-01-01

121

Status of the European Spallation Source ESS AB, the Instrument Selection Process, and a Fundamental Physics Beamline at the ESS  

NASA Astrophysics Data System (ADS)

A general introduction to the status of the European Spallation Source ESS AB is given. As well as a general overview, the status of instruments and instrument design is presented. Particular attention is given to the instrument selection process, and how a proposal for a fundamental neutron physics beamline should be submitted. The contents of this presentation closely reflect the recently completed Technical Design Report for the ESS.

Hall-Wilton, Richard; Theroine, Camille

122

Physical and Chemical Processes Affecting Permeability during Geologic Carbon Sequestration in Arkose and Dolostone: Experimental Observations  

NASA Astrophysics Data System (ADS)

Geologic carbon sequestration in saline sedimentary basins provides a promising option to reduce anthropogenic CO2 emissions. We are conducting experiments using a novel flow system at elevated temperatures and pressures to better understand the physical and chemical processes that result from CO2 injection into these basins and the effects of these processes on system permeability. Here we present experimental results on arkose (primarily K-feldspar and quartz) and dolostone, focusing on CO2 exsolution and fluid-mineral reactions. Following heating-induced CO2 exsolution in an arkose sediment (90-125 ?m) core, XRCT scans revealed abundant pores several times larger than the average grain size. The pores likely grew as exsolved CO2 accumulated in the pores and exerted outspread forces on the surrounding grains. These trapped CO2 accumulations blocked flow pathways, reducing measured permeability by 10,000 times. Another reported experiment on a solid arkose core and water with aqueous CO2 concentrations at 80% saturation dissolved K-feldspar, as evidenced by 3 to 1 ratios of Si to K in sampled fluids, and precipitated an Al-rich mineral, likely gibbsite. SEM images revealed extensive clay precipitation on K-feldspar mineral surfaces. Alteration reduced permeability from 5 × 10-14 m2 to 3 × 10-14 m2 during this 52-day experiment. The third reported experiment on a dolostone core and 1 molal NaCl brine with an aqueous CO2 concentration at 75% saturation caused extensive dissolution and a large increase in permeability. This three-day experiment produced a wormhole of 2 mm in diameter that penetrated the entire 2.6 cm long core with a diameter of 1.3 cm. High, initial Ca and Mg fluid concentrations that quickly receded imply early formation of the wormhole that grew in diameter with time. Our experimental results show that formation permeability can change dramatically from both physical and chemical processes, and these changes should be accounted for during geologic carbon sequestration.

Luhmann, A. J.; Kong, X.; Tutolo, B. M.; Saar, M. O.; Seyfried, W. E.

2012-12-01

123

Fluid flow in the earth's crust plays an important role in a number of geologic processes. In carbonate reservoirs, fluid  

E-print Network

Fluid flow in the earth's crust plays an important role in a number of geologic processes. In carbonate reservoirs, fluid flow is thought to be controlled by open macrofractures. The movement of fluids of fluids is accompanied by substantial change in the pore pressure field. As fluids drain, pore pressure

124

Process and device for the determination of the characteristics of the geological formations traversed by a borehole  

Microsoft Academic Search

A description is given of a process for determining characteristics of the geological formations traversed by a borehole, making use of a sonde by means of which the intensity of the gamma rays naturally radiated from the formations is measured. Both longitudinal and transversal acoustic waves are transmitted to the formations, their travel time and their attenuation between two receivers

J. Bard; P. Morlier; R. Pelet; J. Sarda

1981-01-01

125

Investigating geologic features and processes: A field investigation for earth science students at Leif Erickson Park, Duluth, Minnesota.  

NSDL National Science Digital Library

This activity is a field investigation where students observe and interpret the rocks types, geologic features, and processes typical to the north shore of Lake Superior. Students use their data to develop questions that could be further investigated and to predict the sequence of events leading to the formation of these rocks and features.

Laurie Severson

126

Determining the rates of geological processes in a large-scale metamorphic complex: a multi-method approach  

Microsoft Academic Search

Metamorphic complexes occur at the Earth's surface in many places all over the world. The combined application of different geochronological and thermochronological techniques may help to constrain the rates of geological processes which led to the formation of such metamorphic belts. In this contribution we present the results of a multi-method approach aimed at constraining the timing of burial, heating,

D. Gasser; E. Bruand; K. Stuewe; D. Rubatto; D. A. Foster

2010-01-01

127

Integration of geostatistical techniques and intuitive geology in the 3-D modeling process  

Microsoft Academic Search

The development of 3-D geologic models for reservoir description and simulation has traditionally relied on the computer derived interpolation of well data in a geocelluar stratigraphic framework. The quality of the interpolation has been directly dependent on the nature of the interpolation method, and ability of the Interpolation scheme to accurately predict the value of geologic attributes away from the

C. J. Heine; D. H. Cooper

1996-01-01

128

Integration of geostatistical techniques and intuitive geology in the 3-D modeling process  

Microsoft Academic Search

The development of 3-D geologic models for reservoir description and simulation has traditionally relied on the computer derived interpolation of well data in a geocelluar stratigraphic framework. The quality of the interpolation has been directly dependent on the nature of the interpolation method, and ability of the interpolation scheme to accurately predict the value of geologic attributes away from the

C. J. Heine; D. H. Cooper

1995-01-01

129

Geologic structure and processes of the eastern Pacific margin: California and Costa Rica  

NASA Astrophysics Data System (ADS)

The margin of the eastern Pacific has been sculpted during Tertiary geologic times by convergent and transcurrent plate motion along both continental and oceanic plate boundaries. Interpretations of central California geology predict margin development by Early Tertiary plate convergence, the transition to a transform plate boundary, and subsequent modification of that boundary. Deep penetration seismic reflection transects (EDGE profiles) provide new data to refine these interpretations. These data support the interpretation that a plate fragment related to the Farallon plate may be continued to subduct off California after the Pacific/North America transform boundary was established to the north and south. These seismic data also reveal structures related to probable Miocene transtensional development of the offshore Santa Maria Basin after subduction eventually ceased in this area. The final stage of margin development is one of compressional deformation. This stage is documented by folding and thrust faulting, that appear to be concentrated near the zones of earlier extension and include examples of basin inversion. The Tertiary history of Costa Rica is one of plate convergence in an oceanic island arc setting. In particular, the plate boundary off the Nicoya Peninsula, Costa Rica, is an accretionary convergent margin in a low sediment supply environment. Seismic reflection data, including regional 2D profiles and a 3D survey over a portion of the lower trench slope, show mechanisms of sediment accretion, subsequent compressional deformation, and upper slope extension. The mechanisms of sediment accretion include offscraping at the trench, but the dominant process is underplating. With low sediment supply (no trench turbidites) the sedimentary cover on the subducting Cocos plate is thin and is accreted in small blocks. Variation in the basement structure of the Cocos plate perturbs the accretion processes and affects the arrangement of sedimentary blocks as they are accreted to the prism. The resulting prism structure varies rapidly along strike. The upper slope of the Costa Rica margin features an approximately 20 km wide zone of predominantly landward dipping normal faults. Seismic data show that the faults cut the entire 2 km thick slope apron section and penetrate the underlying accretionary prism.

McIntosh, Kirk Duncan

130

Modeling coupled Thermo-Hydro-Mechanical processes including plastic deformation in geological porous media  

NASA Astrophysics Data System (ADS)

There has been an increasing interest in the recent years in developing computational tools for analyzing coupled thermal, hydrological and mechanical (THM) processes that occur in geological porous media. This is mainly due to their importance in applications including carbon sequestration, enhanced geothermal systems, oil and gas production from unconventional sources, degradation of Arctic permafrost, and nuclear waste isolation. Large changes in pressures, temperatures and saturation can result due to injection/withdrawal of fluids or emplaced heat sources. These can potentially lead to large changes in the fluid flow and mechanical behavior of the formation, including shear and tensile failure on pre-existing or induced fractures and the associated permeability changes. Due to this, plastic deformation and large changes in material properties such as permeability and porosity can be expected to play an important role in these processes. We describe a general purpose computational code FEHM that has been developed for the purpose of modeling coupled THM processes during multi-phase fluid flow and transport in fractured porous media. The code uses a continuum mechanics approach, based on control volume - finite element method. It is designed to address spatial scales on the order of tens of centimeters to tens of kilometers. While large deformations are important in many situations, we have adapted the small strain formulation as useful insight can be obtained in many problems of practical interest with this approach while remaining computationally manageable. Nonlinearities in the equations and the material properties are handled using a full Jacobian Newton-Raphson technique. Stress-strain relationships are assumed to follow linear elastic/plastic behavior. The code incorporates several plasticity models such as von Mises, Drucker-Prager, and also a large suite of models for coupling flow and mechanical deformation via permeability and stresses/deformations. In this work we present several example applications of such models.

Kelkar, S.; Karra, S.; Pawar, R. J.; Zyvoloski, G.

2012-12-01

131

[Fundamental study on stability of dry-processing imager system DRYPRO 722/SD-P].  

PubMed

Dry-processing leaser imager systems have become popular due to the advantages such as the elimination of the cost and labor associated with the wet chemical processing. In this paper, the stability of a dry-processing imager system Drypro 722/SD-P was studied using SMPTE pattern films processed by a dry-processing imager Drypro 722 and a wet-processing imager Li-8/SRX-502 at three different times of the day over a period of five consecutive working days. The dry system is inferior to the wet system on the stability and the spatial uniformity, so that the problems assess the necessity of QC for Drypro 722 Laser Imagers. The instability of the post-processing dry and wet films is also studied. The dry film is very instable compared with the wet film. Accordingly the wet film must be handled with the care. PMID:12766281

Sonobe, Fumie; Toyooka, Kayoko; Abe, Shinji; Tanaka, Takeo; Naka, Eriko; Fujisaki, Tatsuya; Nishimura, Katsuyuki; Saitoh, Hidetoshi; Mochizuki, Yasuo

2002-01-01

132

Interface Induced Carbonate Mineralization: A Fundamental Geochemical Process Relevant to Carbon Sequestration  

SciTech Connect

We have approached the long-standing geochemical question why anhydrous high-Mg carbonate minerals (i.e., magnesite and dolomite) cannot be formed at ambient conditions from a new perspective by exploring the formation of MgCO{sub 3} and Mg{sub x}Ca{sub (1-x)}CO{sub 3} in non-aqueous solutions. Data collected from our experiments in this funding period suggest that a fundamental barrier, other than cation hydration, exists that prevents Mg{sup 2+} and CO{sub 3}{sup 2-} ions from forming long-range ordered structures. We propose that this barrier mainly stems from the lattice limitation on the spatial configuration of CO{sub 3} groups in magnesite crystals. On the other hand, the measured higher distribution coefficients of Mg between magnesian calcites formed in the absence and presence of water give us a first direct proof to support and quantify the cation hydration effect.

Teng, H. Henry [PI, The George Washington University] [PI, The George Washington University; Xu, Huifang [Co-PI, University of Wisconsin-Madison] [Co-PI, University of Wisconsin-Madison

2013-07-17

133

The MESSENGER mission to Mercury: new insights into geological processes and evolution  

NASA Astrophysics Data System (ADS)

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, a part of NASA's Discovery Program, was designed to answer six questions [1]: (1) What planetary formational processes led to Mercury's high ratio of metal to silicate? (2) What is the geological history of Mercury? (3) What are the nature and origin of Mercury's magnetic field? (4) What are the structure and state of Mercury's core? (5) What are the radar-reflective materials at Mercury's poles? (6) What are the important volatile species and their sources and sinks near Mercury? MESSENGER is currently midway through a complex interplanetary cruise phase that involves three flybys of Mercury. The first of these, on 14 January 2008, provided important new information relating to several of the questions above [2-13]. Here we summarize observations made during the flyby that are most relevant to new insights about geological processes that have operated on Mercury and implications for the planet's history [3, 8-13]. The instruments that provided the most direct information on the geological history of Mercury during this first encounter were the Mercury Dual Imaging System (MDIS) [14], the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) [15], and the Mercury Laser Altimeter (MLA) [16]. Among the many specific questions remaining following the Mariner 10 mission to Mercury (1974- 1975) were (1) the level of mineralogical and compositional diversity of the crust, which appeared relatively bland in Mariner 10 data, (2) the nature of the rest of the huge Caloris impact basin seen only partially in Mariner 10 images, (3) the origin of the extensive plains observed on the surface (ponded impact ejecta or extrusive lava flows?), (4) the diversity and global distribution of tectonic features that have deformed the crust and their implications for strain as a function of time, and (5) the bombardment chronology and geological history of Mercury [1, 17-19]. The viewing geometry for the first MESSENGER encounter of Mercury [1] provided important information on these questions from image and remote sensing data on an additional 20% of the surface of Mercury not seen by Mariner 10, as well as comprehensive views of the Caloris basin and its surroundings. MESSENGER MDIS multi-spectral images [8-10] revealed a relatively low-reflectance surface with three broad units identified from reflectance and spectral slope in the wavelength range 0.4-1.0 ?m. These new data helped to confirm the diversity of color units detected in re-processed Mariner 10 color-ratio images [20] and to extend the analysis to larger areas of Mercury. One of these new units is higher in reflectance and forms relatively red plains material that corresponds to a distinct class of smooth plains; these plains, on the basis of their sharp contacts with other units, are interpreted to have been emplaced volcanically. A second unit is represented by lowerreflectance material with a lesser spectral slope and is interpreted to form a distinct crustal component enriched in opaque minerals and possibly more common at depth. A spectrally intermediate terrain appears to form the majority of the upper crust in the newly observed area. Several other spectrally distinct units are found in local regions: (1) moderately high-reflectance, relatively reddish material associated with rimless depressions and located at several places along the interior margin of the Caloris basin rim; (2) highreflectance deposits observed in some impact crater floors; and (3) fresh crater ejecta that is less modified by space weathering than older surface materials. MASCS spectrometer data [9,15] show absorption and spectral slope properties of resolved spectra that are indicative of differences in composition and regolith maturation processes among color units defined by MDIS. Mid-ultraviolet to near-infrared reflectance observations of the surface revealed the presence of a previously unobserved ultraviolet absorption feature that suggests a low FeO content (<2-3 weight %) in silicates in averag

Head, James W., III; Solomon, Sean C.; McNutt, Ralph L., Jr.; Blewett, David T.; Chapman, Clark R.; Domingue, Deborah L.; Evans, Larry G.; Gillis-Davis, Jeffrey J.; Hawkins, S. Edward, III; Helbert, Jörn; Holsclaw, Gregory M.; Izenberg, Noam R.; McClintock, William E.; McCoy, Timothy J.; Merline, William J.; Murchie, Scott L.; Nittler, Larrz R.; Phillips, Roger J.; Prockter, Louise M.; Robinson, Mark S.; Sprague, Ann L.; Strom, Robert G.; Vilas, Faith; Watters, Thomas R.; Zuber, Maria T.

2008-09-01

134

Rheology of petrolatum-paraffin oil mixtures: Applications to analogue modelling of geological processes  

NASA Astrophysics Data System (ADS)

Paraffins have been widely used in analogue modelling of geological processes. Petrolatum and paraffin oil are commonly used to lubricate model boundaries and to simulate weak layers. In this paper, we present rheological tests of petrolatum, paraffin oil and several homogeneous mixtures of the two. The results show that petrolatum and all petrolatum-paraffin oil mixtures are strain, strain rate and temperature dependent under typical experimental strain rates (10-3-10-1 s-1). For the same conditions, pure paraffin oil is a slightly temperature-dependent, linear, Newtonian fluid. All mixtures have yield stress and flow stress (strain softening) values that decrease with decreasing shear rate, and with increasing relative amounts of paraffin oil. The degree of strain rate dependence (shear thinning) also decreases with increasing paraffin oil content. Because these materials have rheologies that can be characterized and controlled, they are suitable for use in a large number of analogue model settings, either as a lubricant or to simulate weak layers. When used as a lubricant, mixtures with higher paraffin oil content should perform better than pure petrolatum.

Duarte, João C.; Schellart, Wouter P.; Cruden, Alexander R.

2014-06-01

135

Application of ERTS images and image processing to regional geologic problems and geologic mapping in northern Arizona  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Computer image processing was shown to be both valuable and necessary in the extraction of the proper subset of the 200 million bits of information in an ERTS image to be applied to a specific problem. Spectral reflectivity information obtained from the four MSS bands can be correlated with in situ spectral reflectance measurements after path radiance effects have been removed and a proper normalization has been made. A detailed map of the major fault systems in a 90,000 sq km area in northern Arizona was compiled from high altitude photographs and pre-existing published and unpublished map data. With the use of ERTS images, three major fault systems, the Sinyala, Bright Angel, and Mesa Butte, were identified and their full extent measured. A byproduct of the regional studies was the identification of possible sources of shallow ground water, a scarce commodity in these regions.

Goetz, A. F. H. (principal investigator); Billingsley, F. C.; Gillespie, A. R.; Abrams, M. J.; Squires, R. L.; Shoemaker, E. M.; Lucchitta, I.; Elston, D. P.

1975-01-01

136

Discussion of fundamental processes in dielectric barrier discharges used for soft ionization  

NASA Astrophysics Data System (ADS)

Permanent need for simple to apply and efficient methods for molecular mass spectrometry resulted in the development of a variety of methods now commonly termed ambient desorption/ionization mass spectrometry (ADI-MS), which experienced a very rapid development during the last 10 years. The most widely used techniques are direct analysis in real time (DART), plasma assisted desorption/ionization (PADI), flowing afterglow-atmospheric pressure glow discharge ionization (FA-APGDI), low-temperature plasma probe (LTP) and dielectric barrier discharge ionization (DBDI). They all share the advantage of direct, ambient analysis of samples with little or no pretreatment, and employ some kind of electrical discharge to desorb and ionize the analyte species. However, the investigations focused on the characterization, examination and understanding of underlying ionization mechanisms of these discharges are relatively small in number. More efforts are clearly needed in this segment, since the understanding of the fundamentals of these discharges is a prerequisite for optimization of working parameters of ADI-MS sources with the aim of increasing ionization efficiency. Here, ADI-MS techniques will be overviewed, with the emphasis put on the review and the analysis of the recent progress in dielectric barrier discharges utilized for soft ionization.

Horvatic, Vlasta; Vadla, Cedomil; Franzke, Joachim

2014-10-01

137

Understanding geological processes: Visualization of rigid and non-rigid transformations  

NASA Astrophysics Data System (ADS)

Visualizations are used in the geological sciences to support reasoning about structures and events. Research in cognitive sciences offers insights into the range of skills of different users, and ultimately how visualizations might support different users. To understand the range of skills needed to reason about earth processes we have developed a program of research that is grounded in the geosciences' careful description of the spatial and spatiotemporal patterns associated with earth processes. In particular, we are pursuing a research program that identifies specific spatial skills and investigates whether and how they are related to each other. For this study, we focus on a specific question: Is there an important distinction in the geosciences between rigid and non-rigid deformation? To study a general spatial thinking skill we employed displays with non-geological objects that had been altered by rigid change (rotation), and two types of non-rigid change ("brittle" (or discontinuous) and "ductile" (or continuous) deformation). Disciplinary scientists (geosciences and chemistry faculty), and novices (non-science faculty and undergraduate psychology students) answered questions that required them to visualize the appearance of the object before the change. In one study, geologists and chemists were found to be superior to non-science faculty in reasoning about rigid rotations (e.g., what an object would look like from a different perspective). Geologists were superior to chemists in reasoning about brittle deformations (e.g., what an object looked like before it was broken - here the object was a word cut into many fragments displaced in different directions). This finding is consistent with two hypotheses: 1) Experts are good at visualizing the types of changes required for their domain; and 2) Visualization of rigid and non-rigid changes are not the same skill. An additional important finding is that there was a broad range of skill in both rigid and non-rigid reasoning within the panels of science experts. In a second study, individual differences in reasoning about brittle deformations were correlated with reasoning about ductile deformations (e.g., what a bent plastic sheet would look like when unbent). Students who were good at visualizing what something looked like before it was broken were also good at visualizing what something looked like before it was bent, and this skill was not correlated to reasoning about rigid rotations. These findings suggest the cognitive processes that support reasoning about rigid and non-rigid events may differ and thus may require different types of support and training. We do not know if differences between experts and novices result from experience or self-selection, or both. Nevertheless, the range of spatial skill evinced by novices and experts strongly argues for designing visualizations to support a variety of users.

Shipley, T. F.; Atit, K.; Manduca, C. A.; Ormand, C. J.; Resnick, I.; Tikoff, B.

2012-12-01

138

INTERPERSONAL RELATIONS AND GROUP PROCESSES Functional Projection: How Fundamental Social Motives Can Bias  

E-print Network

a century ago, Sigmund Freud proposed that people sometimes engage in a process he called projection: attributing their own unacceptable emotions and desires to someone other than themselves (Freud, 1915/1957; cf

Cosmides, Leda

139

Fundamental phenomena on fuel decomposition and boundary-layer combustion processes with applications to hybrid rocket motors  

NASA Technical Reports Server (NTRS)

The experimental study on the fundamental processes involved in fuel decomposition and boundary-layer combustion in hybrid rocket motors is continuously being conducted at the High Pressure Combustion Laboratory of The Pennsylvania State University. This research will provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high-pressure, 2-D slab motor has been designed, manufactured, and utilized for conducting seven test firings using HTPB fuel processed at PSU. A total of 20 fuel slabs have been received from the Mcdonnell Douglas Aerospace Corporation. Ten of these fuel slabs contain an array of fine-wire thermocouples for measuring solid fuel surface and subsurface temperatures. Diagnostic instrumentation used in the test include high-frequency pressure transducers for measuring static and dynamic motor pressures and fine-wire thermocouples for measuring solid fuel surface and subsurface temperatures. The ultrasonic pulse-echo technique as well as a real-time x-ray radiography system have been used to obtain independent measurements of instantaneous solid fuel regression rates.

Kuo, Kenneth K.; Lu, Yeu-Cherng; Chiaverini, Martin J.; Harting, George C.; Johnson, David K.; Serin, Nadir

1995-01-01

140

Fundamental limitations of non-thermal plasma processing for internal combustion engine NO(x) control  

Microsoft Academic Search

The physics and chemistry of non-thermal plasma processing for post-combustion NO(x) control in internal combustion engines are discussed. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NO(x) removal mechanisms, and by-product formation. Can non-thermal deNO(x) operate efficiently without additives or catalysts? How much electrical power does it cost to operate? What

B. M. Penetrante

1993-01-01

141

Fundamental processes in pair plasmas. [electron-positron relativistic plasmas in quasars and active galaxies  

NASA Technical Reports Server (NTRS)

The various processes that produce and destroy electron-positron pairs are reviewed, and the timescales of these processes are compared to thermalization, accretion, and cooling timescales. The various radiation spectra produced by relativistic, thermal plasmas are considered. Recent results for the equilibria available to finite, thermal relativistic plasmas with and without embedded magnetic fields are reviewed. Such plasmas, in steady state, have maximum temperatures, luminosities, and field strengths, useful diagnostics for interpreting quasars and active galaxies.

Lightman, A. P.

1983-01-01

142

Neutron Scattering Studies of Fundamental Processes in Earth Materials, Final Report  

SciTech Connect

The aim of this work was to use neutron scattering techniques to explore the dynamics and structure of water in rock samples. The dynamics of water in rock at low (residual) saturation are directly related to the transport properties of fluids within the host rock. The structure of water in rock may be related to the elastic behavior of the rock, which in many cases is nonlinear and hysteretic. Neutron scattering techniques allow us to study water in intact rock samples at both the molecular and microstructural scales. Our samples were Berea sandstone, Calico Hills and Prow Pass tuffs from Yucca Mountain, NV, and pure samples of the tuff constituents, specifically mordenite and clinoptilolite. We chose Berea sandstone because its macroscopic elastic behavior is known to be highly unusual, and the microscopic mechanisms producing this behavior are not understood. We chose Yucca Mountain tuff, because the fluid transport properties of the geologic structure at Yucca Mountain, Nevada could be relevant to the performance of a high level nuclear waste repository at that site. Neutron scattering methods have a number of properties that are extremely useful for the study of earth materials. In contrast to X-rays, neutrons have very low absorption cross-sections for most elements so that entire bulk samples of considerable size can be 'illuminated' by the neutron beam. Similarly, samples that are optically opaque can be readily investigated by inelastic neutron scattering techniques. Neutrons are equally sensitive to light atoms as to heavy atoms, and can, for example, readily distinguish between Al and Si, neighboring atoms in the periodic table that are difficult to tell apart by X-ray diffraction. Finally, neutrons are particularly sensitive to hydrogen and thus can be used to study the motions, both vibrational and diffusive, of H-containing molecules in rocks, most notably of course, water. Our studies were primarily studies of guest molecules (in our case, water) in a host material (rock). We used three neutron scattering techniques: quasielastic neutron scattering (QNS), inelastic neutron scattering (INS), and neutron powder diffraction (NPD). We used QNS to measure the translational and rotational diffusional motion of water in rock; INS vibrational spectra allowed us to determine the nature of residual water in a sample (disassociated, chemisorbed, or physisorbed); and NPD measurements may allow us to determine the locations of residual water molecules (and the associated dynamic disorder), and thereby understand the binding of water molecules in our samples.

McCall, K. R.

2007-06-11

143

Nanosecond Pulse Discharges and Fast Ionization Wave Discharges: Fundamental Kinetic Processes and Applications  

NASA Astrophysics Data System (ADS)

Over the last two decades, nanosecond pulse discharges and Fast Ionization Wave (FIW) discharges have been studied extensively, both theoretically and experimentally. Current interest in characterization of these discharges is driven mainly by their potential for applications such as plasma chemical fuel reforming, plasma-assisted combustion, high-speed flow control, pumping of electric discharge excited lasers, and generation of high-energy electrons. A unique capability of FIW discharges to generate significant ionization and high concentrations of excited species at high pressures and over large distances, before ionization instabilities have time to develop, is very attractive for these applications. Recent advances in laser optical diagnostics offer an opportunity of making non-intrusive, spatially and time-resolved measurements of electron density and electric field distributions in high-speed ionization wave discharges, on nanosecond time scale. Insight into FIW formation and propagation dynamics also requires development of predictive kinetic models, and their experimental validation. Although numerical kinetic models may incorporate detailed kinetics of charged and neutral species in the propagating ionization wave front (including non-local electron kinetics), analytic models are also attractive due to their capability of elucidating fundamental trends of discharge development. The talk gives an overview of recent progress in experimental characterization and kinetic modeling of nanosecond pulse and fast ionization wave discharges in nitrogen and air over a wide range of pulse repetition rates, 0.1-40 kHz. FIW discharge plasmas sustained at high pulse repetition rates are diffuse and volume filling, with most of the power coupled to the plasma behind the wave, at E/N=200-300 Td and energy loading of 1-2 meV/molecule/pulse. The results demonstrate significant potential of large volume, diffuse, high pulse repetition rate FIW discharges for novel plasma chemical applications.

Adamovich, Igor

2011-11-01

144

Fundamental processes capable of accounting for the neutron flux enhancements in a thunderstorm atmosphere  

NASA Astrophysics Data System (ADS)

Elementary processes capable of producing neutrons in a thunderstorm atmosphere are analyzed. The efficiency of nuclear fusion 2H(2H, n)3He, photonuclear reactions (?, Xn), electrodisintegration reactions {/m n }A( e -, n){/m n-1}, and reactions e -( p +, n)? e opposite to the ?-decay is evaluated. It is shown that an unrealistically strong electric field is required for the nuclear fusion to be responsible for the neutron production in the lightning channel. The generation of neutrons in a thunderstorm atmosphere is connected with photonuclear (?, Xn) and, at a much lower degree, electrodisintegration reactions, the relativistic runaway electron avalanches being primary parent processes.

Babich, L. P.

2014-03-01

145

Silicate Carbonation Processes in Water-Bearing Supercritical CO2 Fluids: Implications for Geologic Carbon Sequestration  

NASA Astrophysics Data System (ADS)

Global climate change is viewed by many as an anthropogenic phenomenon that could be mitigated through a combination of conservation efforts, alternative energy sources, and the development of technologies capable of reducing carbon dioxide (CO2) emissions. Continued increases of atmospheric CO2 concentrations are projected over the next decade, due to developing nations and growing populations. One economically favorable option for managing CO2 involves subsurface storage in deep basalt formations. The silicate minerals and glassy mesostasis basalt components act as metal cation sources, reacting with the CO2 to form carbonate minerals. Most prior work on mineral reactivity in geologic carbon sequestration settings involves only aqueous dominated reactions. However, in most sequestration scenarios, injected CO2 will reside as a buoyant fluid in contact with the sealing formation (caprock) and slowly become water bearing. Comparatively little laboratory research has been conducted on reactions occurring between minerals in the host rock and the wet scCO2. In this work, we studied the carbonation of wollastonite [CaSiO3] exposed to variably wet supercritical CO2 (scCO2) at a range of temperatures (50, 55 and 70 °C) and pressures (90,120 and 160 bar) in order to gain insight into reaction processes. Mineral transformation reactions were followed by two novel in situ high pressure techniques, including x-ray diffraction that tracked the rate and extents of wollastonite conversion to calcite. Increased dissolved water concentrations in the scCO2 resulted in increased carbonation approaching ~50 wt. %. Development of thin water films on the mineral surface were directly observed with infrared (IR) spectroscopy and indirectly with 18O isotopic labeling techniques (Raman spectroscopy). The thin water films were determined to be critical for facilitating carbonation processes in wet scCO2. Even in extreme low water conditions, the IR technique detected the formation of amorphous silica. Unlike the thick (<10 ?m) passivating silica layers observed in the reacted samples from fully water saturated scCO2 experiments, images obtained from a focused ion beam sectioned sample indicted these coatings were chemically wollastonite but structurally amorphous. In addition, evidence of an intermediate hydrated amorphous calcium carbonate forming under these conditions further emphasize the importance of understanding geochemical processes occurring in water-bearing scCO2 fluids.

Miller, Q. R.; Schaef, T.; Thompson, C.; Loring, J. S.; Windisch, C. F.; Bowden, M. E.; Arey, B. W.; McGrail, P.

2012-12-01

146

Processing and geologic analysis of conventional cores from well ER-20-6 No. 1, Nevada Test Site  

SciTech Connect

In 1996, Well Cluster ER-20-6 was drilled on Pahute Mesa in Area 20, in the northwestern corner of the Nevada Test Site (NTS). The three wells of the cluster are located from 166 to 296 meters (m) (544 to 971 feet [ft]) southwest of the site of the underground nuclear test code-named BULLION, conducted in 1990 in Emplacement Hole U-20bd. The well cluster was planned to be the site of a forced-gradient experiment designed to investigate radionuclide transport in groundwater. To obtain additional information on the occurrence of radionuclides, nature of fractures, and lithology, a portion of Well ER-20-6 No. 1, the hole closest to the explosion cavity, was cored for later analysis. Bechtel Nevada (BN) geologists originally prepared the geologic interpretation of the Well Cluster ER-20-6 site and documented the geology of each well in the cluster. However, the cores from Well ER-20-6 No. 1 were not accessible at the time of that work. As the forced-gradient experiment and other radio nuclide migration studies associated with the well cluster progressed, it was deemed appropriate to open the cores, describe the geology, and re-package the core for long-term air-tight storage. This report documents and describes the processing, geologic analysis, and preservation of the conventional cores from Well ER20-6 No. 1.

Prothro, L.B., Townsend, M.J.; Drellack, S.L. Jr. [and others

1997-09-01

147

Welding Process Fundamentals* Thomas W. Eagar and Aaron D. Mazzeo, Massachusetts Institute of Technology  

E-print Network

replacement of steel by aluminum in the frames of nonluxury automobiles. An increased use of composites the weakest parts of that assembly. Careful attention to weldment design and joining processes can produce always be achieved. The economics of joining a material may limit its usefulness. For example, aluminum

Eagar, Thomas W.

148

Role of fundamental defect processes in irradiation correlation in structural materials for nuclear energy systems  

NASA Astrophysics Data System (ADS)

A number of recent problems in structural materials for nuclear energy systems require quantitative and reliable predictions of materials behaviour in as yet unrealized operating conditions. An example is found in pressure vessel steels of a light water reactor, where prediction of embrittlement of the steel for extended period of service must be done with confidence, because the integrity of the pressure vessel is of vital importance for the safety of the light water reactor. Light water reactor fuel, cladding and wrapper of a fast breeder reactor and first wall and blanket structural materials of a fusion reactor are such examples that are briefly discussed. In such problems, we have either scarce data or limited and rather irrelevant data of the materials performance for the service conditions of the materials in question. The method used to predict the irradiation behaviour of materials from incomplete existing data is called irradiation correlation. The correlation methodology is discussed. To describe the materials behaviour, the component processes should be modelled in terms of elemental defect processes. These models are then integrated to describe the materials behaviour. Charged particle irradiations have been most successfully applied for the study of the component processes because the associated defect processes are studied with less ambiguity largely due to the controllability of experimental conditions. Systematically changing the single experimental parameter among various influencing parameters is vitally important. A successful example of the irradiation correlation is discussed.

Ishino, Shiori

149

A COMPLETE FERREDOXIN/THIOREDOXIN SYSTEM REGULATES FUNDAMENTAL PROCESSES IN AMYLOPLASTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A growing number of processes throughout biology are regulated by redox via thiol-disulfide exchange. This mechanism is particularly widespread in plants where almost 200 proteins have been linked to thioredoxin (Trx), a widely distributed small regulatory disulfide protein. The current study extend...

150

Application of the "Full Cavitation Model" to the fundamental study of cavitation in liquid metal processing  

NASA Astrophysics Data System (ADS)

Ultrasonic cavitation treatment of melt significantly improves the downstream properties and quality of conventional and advanced metallic materials. However, the transfer of this technology has been hindered by difficulties in treating large volumes of liquid metal. To improve the understanding of cavitation processing efficiency, the Full Cavitation Model, which is derived from a reduced form of the Rayleigh-Plesset equation, is modified and applied to the two-phase problem of bubble propagation in liquid melt. Numerical simulations of the sound propagation are performed in the microsecond time scale to predict the maximum and minimum acoustic pressure amplitude fields in the domain. This field is applied to the source term of the bubble transport equation to predict the generation and destruction of cavitation bubbles in a time scale relevant to the fluid flow. The use of baffles to limit flow speed in a launder conduit is studied numerically, to determine the optimum configuration that maximizes the residence time of the liquid in high cavitation activity regions. With this configuration, it is then possible to convert the batch processing of liquid metal into a continuous process. The numerical simulations will be validated against water and aluminium alloy experiments, carried out at Brunel University.

Lebon, G. S. B.; Pericleous, K.; Tzanakis, I.; Eskin, D.

2015-01-01

151

Geological SciencesGeological Sciences Geological EngineeringGeological Engineering  

E-print Network

Geological SciencesGeological Sciences Geological EngineeringGeological Engineering Geosciences Careers in the ik ou ve n ver see t b f rel e y ' e n i e o ! Department of Geological Sciences and Geological Engineering Queen's University See the World Geological Sciences Arts and Science Faculty

Ellis, Randy

152

Sea-floor geology and sedimentary processes in the vicinity of Cross Rip Channel, Nantucket Sound, offshore southeastern Massachusetts  

USGS Publications Warehouse

Gridded multibeam bathymetry covers approximately 10.4 square kilometers of sea floor in the vicinity of Cross Rip Channel in Nantucket Sound, offshore southeastern Massachusetts. Although originally collected for charting purposes during National Oceanic and Atmospheric Administration hydrographic survey H12007, these acoustic data, and the sea-floor sediment sampling and bottom photography stations subsequently occupied to verify them, show the composition and terrain of the seabed and provide information on sediment transport and benthic habitat. This report is part of an expanding series of cooperative studies by the U.S. Geological Survey, National Oceanic and Atmospheric Administration, and Massachusetts Office of Coastal Zone Management that provide a fundamental framework for research and resource-management activities (for example, windfarms, pipelines, and dredging) along the inner continental shelf offshore of Massachusetts.

Poppe, L.J.; McMullen, K.Y.; Ackerman, S.D.; Schaer, J.D.; Wright, D.B.

2012-01-01

153

September 2012 BASIN RESEARCH AND ENERGY GEOLOGY  

E-print Network

September 2012 BASIN RESEARCH AND ENERGY GEOLOGY STATE UNIVERSITY OF NEW YORK at BINGHAMTON research programs in geochemistry, sedimentary geology, or Earth surface processes with the potential the position, visit the Geological Sciences and Environmental Studies website (www.geology

Suzuki, Masatsugu

154

Separation and purification of lactic acid: Fundamental studies on the reverse osmosis down-stream process  

Microsoft Academic Search

The physico-chemical properties and effects of lactic acid and lactates in the reverse osmosis process were investigated using a polyamide composite membrane. The membrane was found to swell at pH 2.2, yet has no detectable solute-membrane affinity. The decrease in flux and increase in the solute reduction factor of lactic acid (0.66 m3.m?2.d?1; 5.8), ammonium lactate (0.30 m3.m?2.d?2.d?1; 18.3) and

M. K. H. Liew; S. Tanaka; M. Morita

1995-01-01

155

Linking Geologic Framework to Nearshore Processes and Shoreline Change: Results from the Outer Banks of North Carolina  

NASA Astrophysics Data System (ADS)

Within the coastal geology community, a consensus appears to have developed that the geologic framework of the inner-shelf plays an important role in shoreline change. It has yet to be determined, however, whether geology exerts a first-order control on shoreline dynamics and, if so, across what time and spatial scales. Furthermore, principal mechanisms that may link underlying geology and shoreline behavior remain poorly understood and untested. To this end, an extensive survey of the seafloor surface and shallow sub-bottom utilizing an interferometric swath bathymetry sonar system and a chirp sub-bottom profiler mounted on an amphibious vessel was conducted across the surf zone of the Outer Banks of North Carolina. Recent findings from a small region near Duck, North Carolina suggest a connection between partial exposure of pre-modern, non-sandy substrates in the surf zone and bar morphodynamics leading to the repeated occurrence of shoreline hotspots. Support from the US Geological Survey, US Army Corps of Engineers, and the Army Research Office has expanded this work to include a 40 km length of surf zone extending from Duck to Nags Head, North Carolina. Preliminary results from the larger survey are consistent with earlier findings at Duck which show: 1) an underlying ravinement surface with very irregular relief across the surf zone; 2) a thin cover of modern sand, ranging from 0 to a maximum of 2.5 m thick, with a surface morphology that does not necessarily mirror the underlying topography; 3) the presence of large transverse bars located beside exposures of non-sandy substrate; and 4) a spatial correlation between hotspots and regions with exposed non-sandy substrates and transverse bars in the surf zone. Future work will examine shoreline behavior and bar morphodynamics associated with the geologic framework of the nearshore over event and seasonal time scales. These observations will be designed to provide insight into the processes responsible for hotspot formation and to identify key geologic variables that could be incorporated into, and ultimately, improve shoreline evolution models.

McNinch, J. E.; Miselis, J. L.; Schupp, C. A.

2002-12-01

156

Fundamental Etching and Roughening Mechanisms of Photoresist Polymers during Plasma Processing  

NASA Astrophysics Data System (ADS)

Reducing the etching and roughening of photoresist polymers during plasma processing is required as optical lithography for integrated circuit manufacture is extended to patterning features with critical dimension control on the order of nanometers. We use a vacuum beam system to simulate plasma exposure but under well-defined conditions. Samples are exposed to well-characterized beams of ions, vacuum ultraviolet (VUV) radiation, and electrons under high vacuum conditions. Post-exposure analysis includes atomic force and scanning electron microscopy and FTIR spectroscopy. We show that VUV radiation, ion bombardment, the ion / photon flux ratio and heating all play a role in the roughening of current-generation PMMA-based 193 nm photoresists. VUV radiation breaks carbon-oxygen bonds to a depth of approximately 100 nm whereas ion bombardment forms a dehydrogenated surface layer. Qualitatively similar roughening was observed in plasmas with the same ion bombardment energy and ion and VUV fluence.

Nest, Dustin; Chung, Ting-Ying; Graves, David; Weilnboeck, Florian; Bruce, Robert; Lin, Tsung Cheng; Phaneuf, Ray; Oehrlein, Gottlieb; Hudson, Eric; Wang, Deyan; Andes, Cecily

2009-03-01

157

Combustion Fundamentals Research  

NASA Technical Reports Server (NTRS)

Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

1983-01-01

158

Thioredoxin targets fundamental processes in a methane-producing archaeon, Methanocaldococcus jannaschii  

PubMed Central

Thioredoxin (Trx), a small redox protein, controls multiple processes in eukaryotes and bacteria by changing the thiol redox status of selected proteins. The function of Trx in archaea is, however, unexplored. To help fill this gap, we have investigated this aspect in methanarchaea—strict anaerobes that produce methane, a fuel and greenhouse gas. Bioinformatic analyses suggested that Trx is nearly universal in methanogens. Ancient methanogens that produce methane almost exclusively from H2 plus CO2 carried approximately two Trx homologs, whereas nutritionally versatile members possessed four to eight. Due to its simplicity, we studied the Trx system of Methanocaldococcus jannaschii—a deeply rooted hyperthermophilic methanogen growing only on H2 plus CO2. The organism carried two Trx homologs, canonical Trx1 that reduced insulin and accepted electrons from Escherichia coli thioredoxin reductase and atypical Trx2. Proteomic analyses with air-oxidized extracts treated with reduced Trx1 revealed 152 potential targets representing a range of processes—including methanogenesis, biosynthesis, transcription, translation, and oxidative response. In enzyme assays, Trx1 activated two selected targets following partial deactivation by O2, validating proteomics observations: methylenetetrahydromethanopterin dehydrogenase, a methanogenesis enzyme, and sulfite reductase, a detoxification enzyme. The results suggest that Trx assists methanogens in combating oxidative stress and synchronizing metabolic activities with availability of reductant, making it a critical factor in the global carbon cycle and methane emission. Because methanogenesis developed before the oxygenation of Earth, it seems possible that Trx functioned originally in metabolic regulation independently of O2, thus raising the question whether a complex biological system of this type evolved at least 2.5 billion years ago. PMID:24505058

Susanti, Dwi; Wong, Joshua H.; Vensel, William H.; Loganathan, Usha; DeSantis, Rebecca; Schmitz, Ruth A.; Balsera, Monica; Buchanan, Bob B.; Mukhopadhyay, Biswarup

2014-01-01

159

A complete ferredoxin/thioredoxin system regulates fundamental processes in amyloplasts  

PubMed Central

A growing number of processes throughout biology are regulated by redox via thiol–disulfide exchange. This mechanism is particularly widespread in plants, where almost 200 proteins have been linked to thioredoxin (Trx), a widely distributed small regulatory disulfide protein. The current study extends regulation by Trx to amyloplasts, organelles prevalent in heterotrophic plant tissues that, among other biosynthetic activities, catalyze the synthesis and storage of copious amounts of starch. Using proteomics and immunological methods, we identified the components of the ferredoxin/Trx system (ferredoxin, ferredoxin–Trx reductase, and Trx), originally described for chloroplasts, in amyloplasts isolated from wheat starchy endosperm. Ferredoxin is reduced not by light, as in chloroplasts, but by metabolically generated NADPH via ferredoxin–NADP reductase. However, once reduced, ferredoxin appears to act as established for chloroplasts, i.e., via ferredoxin–Trx reductase and a Trx (m-type). A proteomics approach in combination with affinity chromatography and a fluorescent thiol probe led to the identification of 42 potential Trx target proteins, 13 not previously recognized, including a major membrane transporter (Brittle-1 or ADP-glucose transporter). The proteins function in a range of processes in addition to starch metabolism: biosynthesis of lipids, amino acids, and nucleotides; protein folding; and several miscellaneous reactions. The results suggest a mechanism whereby light is initially recognized as a thiol signal in chloroplasts, then as a sugar during transit to the sink, where it is converted again to a thiol signal. In this way, amyloplast reactions in the grain can be coordinated with photosynthesis taking place in leaves. PMID:16481623

Balmer, Yves; Vensel, William H.; Cai, Nick; Manieri, Wanda; Schürmann, Peter; Hurkman, William J.; Buchanan, Bob B.

2006-01-01

160

Fundamentals and Applications of a Plasma Processing System Based on Electron Beam Ionization  

NASA Astrophysics Data System (ADS)

Electron beam (e-beam) ionization has been shown to be both efficient at producing plasma and scalable to large area (square meters). NRL has developed a number of advanced research tools culminating in a ``Large Area Plasma Processing System'' (LAPPS) based on an e-beam sheet geometry. We have demonstrated that the beam ionization process is fairly independent of gas composition and capable of producing low temperature plasma electrons (<0.5 eV in molecular gases) in high densities (10^9-10^12 cm-3). This system can offer increased control of plasma-to-surface fluxes and the ability to modify materials' surface properties uniformly over large areas. The systems to be discussed consist of continuous and pulsed planar plasma distributions generated by a magnetically collimated sheet of 2-3kV, < 1 mA/cm^2 electrons injected into a neutral gas background (oxygen, nitrogen, sulfur hexafluoride, argon). Typical operating pressures range from 20-150 mTorr with beam-collimating magnetic fields (100-200 Gauss) for plasma localization. The attributes of beam-generated plasmas make them ideal for many materials applications. These systems have been investigated for a broad range of applications, including surface activation, line edge roughening, and anisotropic etching of polymers, electron-ion and ion-ion plasma etching, low-temperature metal nitriding and thin film deposition (reactive sputtering and plasma enhanced chemical vapor deposition). Details of some of these applications will be discussed in terms of the critical plasma physics and chemistry, with complementary time-resolved in situ plasma diagnostics (Langmuir probes, microwave transmission, energy-resolved mass spectrometry and laser spectroscopy).

Leonhardt, Darrin

2006-10-01

161

Process-based approach to CO2 leakage detection by vadose zone gas monitoring at geologic CO2 storage sites  

NASA Astrophysics Data System (ADS)

A critical issue for geologic carbon sequestration is the ability to detect CO2 in the vadose zone. Here we present a new process-based approach to identify CO2 that has leaked from deep geologic storage reservoirs into the shallow subsurface. Whereas current CO2 concentration-based methods require years of background measurements to quantify variability of natural vadose zone CO2, this new approach examines chemical relationships between vadose zone N2, O2, CO2, and CH4 to promptly distinguish a leakage signal from natural vadose zone CO2. The method uses sequential inspection of the following gas concentration relationships: 1) O2 versus CO2 to distinguish in-situ vadose zone background processes (biologic respiration, methane oxidation, and CO2 dissolution) from exogenous deep leakage input, 2) CO2 versus N2 to further distinguish dissolution of CO2 from exogenous deep leakage input, and 3) CO2 versus N2/O2 to assess the degree respiration, CH4 oxidation and atmospheric mixing/dilution occurring in the system. The approach was developed at a natural CO2-rich control site and successfully applied at an engineered site where deep gases migrated into the vadose zone. The ability to identify gas leakage into the vadose zone without the need for background measurements could decrease uncertainty in leakage detection and expedite implementation of future geologic CO2 storage projects.

Romanak, K. D.; Bennett, P. C.; Yang, Changbing; Hovorka, Susan D.

2012-08-01

162

Spectral Image Processing Theory and Methods: Reconstruction, Target Detection, and Fundamental Performance Bounds  

NASA Astrophysics Data System (ADS)

This dissertation presents methods and associated performance bounds for spectral image processing tasks such as reconstruction and target detection, which are useful in a variety of applications such as astronomical imaging, biomedical imaging and remote sensing. The key idea behind our spectral image processing methods is the fact that important information in a spectral image can often be captured by low-dimensional manifolds embedded in high-dimensional spectral data. Based on this key idea, our work focuses on the reconstruction of spectral images from photon-limited, and distorted observations. This dissertation presents a partition-based, maximum penalized likelihood method that recovers spectral images from noisy observations and enjoys several useful properties; namely, it (a) adapts to spatial and spectral smoothness of the underlying spectral image, (b) is computationally efficient, (c) is near-minimax optimal over an anisotropic Holder-Besov function class, and (d) can be extended to inverse problem frameworks. There are many applications where accurate localization of desired targets in a spectral image is more crucial than a complete reconstruction. Our work draws its inspiration from classical detection theory and compressed sensing to develop computationally efficient methods to detect targets from few projection measurements of each spectrum in the spectral image. Assuming the availability of a spectral dictionary of possible targets, the methods discussed in this work detect targets that either come from the spectral dictionary or otherwise. The theoretical performance bounds offer insight on the performance of our detectors as a function of the number of measurements, signal-to-noise ratio, background contamination and properties of the spectral dictionary. A related problem is that of level set estimation where the goal is to detect the regions in an image where the underlying intensity function exceeds a threshold. This dissertation studies the problem of accurately extracting the level set of a function from indirect projection measurements without reconstructing the underlying function. Our partition-based set estimation method extracts the level set of proxy observations constructed from such projection measurements. The theoretical analysis presented in this work illustrates how the projection matrix, proxy construction and signal strength of the underlying function affect the estimation performance.

Krishnamurthy, Kalyani

2011-12-01

163

Fundamental study in FSW processing and FSW process-structure-property relationship for AA2024 and AA2524  

NASA Astrophysics Data System (ADS)

Friction stir welding (FSW) is a relatively new joining technique, copious data have been generated on the properties of FSWs in many alloys, but the factors governing the microstructure and properties of the nugget zone in precipitation hardenable aluminum alloy FSWs are still not fully understood. A series of FSW experiments and analyses were performed on precipitate hardening aluminum alloys AA2024-T351 and AA2524-T351 with an attempt to develop the process-structure-property correlation and characterize the processing and banding in these process and resultant joints. Results indicate that among the three control variables, rotation speed has the dominant effect on the nugget microstructure and property in AA2524 FSWs compared with welding speed and Fz force. For a given welding speed and z-axis force, there is an optimum rotation speed to produce a good combination of nugget ultimate tensile strength and elongation, higher rotation speed will cause overheating that results in grain boundary melting resulting in a big drop in elongation and ultimate tensile strength while having little inverse effect on the hardness and yield strength. The welding torque has a strong and good inverse proportional relationship with grain size, nugget hardness, yield strength and ultimate tensile strength. The effect of rotation speed, welding speed and z-axis force on the grain size, hardness and tensile properties can be rationalized based on their contribution to the welding torque. Results from processing and banding analysis show that there are well-defined periodic variations in the processing forces Fx and Fz during welding and periodic, semi-circular bands on the horizontal transverse cross-section for all the welds over a wide range of welding conditions. The measured band spacing is closely equal to the oscillation period of the Fx and Fz force of the welding tool, both are in good agreement with the FSW processing pitch. Different pin form tool may result in the difference between these banded structures, but could not change the relationship between processing and banding. The periodic banded structure in the nugget consists of alternating variation of grain size, particle distribution and micro-hardness variation, and would result in periodic variations of the measured strain response under loading. The direct and consistent relationship observed among periodicity in variation of Fx and Fz and the metallurgical and mechanical behavior indicate that the formation of banded structures in FSW joints is related to the periodic variation of welding parameters. (Abstract shortened by UMI.)

Yan, Junhui

164

SMART-1 highlights and relevant studies on early bombardment and geological processes on rocky planets  

NASA Astrophysics Data System (ADS)

We present results from SMART-1 science and technology payload, in the context of the Nobel symposium on 'Physics of Planetary Systems'. SMART-1 is Europe' first lunar mission (Foing et al 2000 LPSC XXXI Abstract #1677 (CDROM); Foing et al 2001 Earth, Moon Planets 85 86 523 31 Marini et al 2002 Adv. Space Res. 30 1895 900 Racca et al 2001 Earth Moon Planets 85 86 379 95, Racca et al 2002 Planet Space Sci. 50 1323 37) demonstrating technologies for future science and exploration missions, and providing advances in our understanding of lunar origin and evolution, and general planetary questions. The mission also contributes a step in developing an international program of lunar exploration. The spacecraft, launched on 27 September 2003 as an Ariane 5 Auxiliary passenger to geostationary transfer orbit (GTO), performed a 14-month long cruise using a tiny thrust of electric propulsion alone, reached lunar capture in November 2004, and lunar science orbit in March 2005. SMART-1 carried 7 hardware experiments (Foing et al 2003 Adv. Space Res. 31 2323, Foing et al 2005 LPI/LPSC XXXVI 2404 (CDROM)) performing 10 investigations, including 3 remote-sensing instruments, used during the cruise, the mission' nominal six-months and one-year extension in lunar science orbit. Three remote sensing instruments, D-CIXS, SIR and AMIE, have returned data that are relevant to a broad range of lunar studies. The mission provided regional and global x-ray measurements of the Moon, global high-spectral resolution NIR spectrometry, high spatial resolution colour imaging of selected regions. The South Pole-Aitken Basin (SPA) and other impact basins have been prime targets for studies using the SMART-1 suite of instruments. Combined, these should aid a large number of science studies, from bulk crustal composition and theories of lunar origin/evolution, the global and local crustal composition, to the search for cold traps at the lunar poles and the mapping of potential lunar resources. We present here SMART-1 results relevant to the study of the early bombardment and geological processes on rocky planets. Further information and updates on the SMART-1 mission can be found on the ESA Science and Technology web pages, at: http://sci.esa.int/smart-1/.

Foing, B. H.; Racca, G. D.; Josset, J. L.; Koschny, D.; Frew, D.; Almeida, M.; Zender, J.; Heather, D.; Peters, S.; Marini, A.; Stagnaro, L.; Beauvivre, S.; Grande, M.; Kellett, B.; Huovelin, J.; Nathues, A.; Mall, U.; Ehrenfreund, P.; McCannon, P.

2008-08-01

165

Fundamental Analysis of Piezocatalysis Process on the Surfaces of Strained Piezoelectric Materials  

PubMed Central

Recently, the strain state of a piezoelectric electrode has been found to impact the electrochemical activity taking place between the piezoelectric material and its solution environment. This effect, dubbed piezocatalysis, is prominent in piezoelectric materials because the strain state and electronic state of these materials are strongly coupled. Herein we develop a general theoretical analysis of the piezocatalysis process utilizing well-established piezoelectric, semiconductor, molecular orbital and electrochemistry frameworks. The analysis shows good agreement with experimental results, reproducing the time-dependent voltage drop and H2 production behaviors of an oscillating piezoelectric Pb(Mg1/3Nb2/3)O3-32PbTiO3 (PMN-PT) cantilever in deionized water environment. This study provides general guidance for future experiments utilizing different piezoelectric materials, such as ZnO, BaTiO3, PbTiO3, and PMN-PT. Our analysis indicates a high piezoelectric coupling coefficient and a low electrical conductivity are desired for enabling high electrochemical activity; whereas electrical permittivity must be optimized to balance piezoelectric and capacitive effects. PMID:23831736

Starr, Matthew B.; Wang, Xudong

2013-01-01

166

Hydrogel microparticles from lithographic processes: novel materials for fundamental and applied colloid science  

PubMed Central

In recent years there has been a surge in methods to synthesize geometrically and chemically complex microparticles. Analogous to atoms, the concept of a “periodic table” of particles has emerged and continues to be expanded upon. Complementing the natural intellectual curiosity that drives the creation of increasingly intricate particles is the pull from applications that take advantage of such high-value materials. Complex particles are now being used in fields ranging from diagnostics and catalysis to self-assembly and rheology, where material composition and microstructure are closely linked with particle function. This is especially true of polymer hydrogels, which offer an attractive and broad class of base materials for synthesis. Lithography affords the ability to engineer particle properties a priori and leads to the production of homogenous ensembles of particles. This review summarizes recent advances in synthesizing hydrogel microparticles using lithographic processes and highlight a number of emerging applications. We discuss advantages and limitations of current strategies, and conclude with an outlook on future trends in the field. PMID:21516212

Helgeson, Matthew E.; Chapin, Stephen C.; Doyle, Patrick S.

2011-01-01

167

Femtosecond dynamics of fundamental reaction processes in liquids: Proton transfer, geminate recombination, isomerization and vibrational relaxation  

SciTech Connect

The fast excited state intramolecular proton transfer of 3-hydroxyflavone is measured and effects of external hydrogen-bonding interactions on the proton transfer are studied. The proton transfer takes place in {approximately}240 fsec in nonpolar environments, but becomes faster than instrumental resolution of 110 fsec in methanol solution. The dynamics following photodissociation of CH{sub 2}I{sub 2} and other small molecules provide the first direct observations of geminate recombination. The recombination of many different photodissociating species occurs on a {approximately}350 fsec time scale. Results show that recombination yields but not rates depend on the solvent environment and suggest that recombination kinetics are dominated by a single collision with surrounding solvent cage. Studies of sterically locked phenyl-substituted butadienes offer new insights into the electronic structure and isomerization behavior of conjugated polyenes. Data show no simple correlation between hinderance of specific large amplitude motions and signatures of isomerizative behavior such as viscosity dependent excited state lifetimes, implying that the isomerization does not provide a suitable for simple condensed phase reaction rate theories. The spectral dynamics of a photochromic spiropyran indicate that recombination, isomerization and vibrational relaxation all play important roles in photoreactivity of complex molecules. The interplay of these microscopic phenomena and their effect on macroscopic properties such as photochromism are discussed. All the results indicate that the initial steps of the photochromic reaction process occur extremely rapidly. Laser system and computer codes for data analysis are discussed.

Schwartz, B.J.

1992-11-01

168

Consideration of some fundamental erosion processes encountered in hypervelocity electromagnetic propulsion  

SciTech Connect

Experimental and theoretical research has been conducted jointly at the Livermore and Los Alamos National laboratories on dc electromagnetic railgun Lorentz accelerators. Pellets weighing a few grams to tens of grams have been launched at velocities up to better than 11 km/s. The research is addressed to attaining repeated launches of samples at hypervelocity in target impact experiments. In these experiments, shock-induced pressures in the tens of megabars range are obtained for high pressure equation-of-state research. Primary energy sources of the order of several hundred kJ to a MJ and induction currents of the order of 1 or more MA are necessary for these launches. Erosion and deformation of the conductor rails and the accelerated sample material are continuing problems. The heating, stress, and erosion resulting from simultaneous imposition of rail induction current, dense plasma (armature) interaction, current distribution, magnetic field stresses and projectile/rail contact friction are examined. It is found that while frictional heating and consequent sliding contact erosion are minor contributors to the overall erosion process, the same cannot be said for plasma impingement, penetration, and almost simultaneous induction current (Joule) heating.

Buckingham, A.C.; Hawke, R.S.

1982-09-30

169

Advanced Small Rocket Chambers. Basic Program and Option 2: Fundamental Processes and Material Evaluation  

NASA Technical Reports Server (NTRS)

Propellants, chamber materials, and processes for fabrication of small high performance radiation cooled liquid rocket engines were evaluated to determine candidates for eventual demonstration in flight-type thrusters. Both storable and cryogenic propellant systems were considered. The storable propellant systems chosen for further study were nitrogen tetroxide oxidizer with either hydrazine or monomethylhydrazine as fuel. The cryogenic propellants chosen were oxygen with either hydrogen or methane as fuel. Chamber material candidates were chemical vapor deposition (CVD) rhenium protected from oxidation by CVD iridium for the chamber hot section, and film cooled wrought platinum-rhodium or regeneratively cooled stainless steel for the front end section exposed to partially reacted propellants. Laser diagnostics of the combustion products near the hot chamber surface and measurements at the surface layer were performed in a collaborative program at Sandia National Laboratories, Livermore, CA. The Material Sample Test Apparatus, a laboratory system to simulate the combustion environment in terms of gas and material temperature, composition, and pressure up to 6 Atm, was developed for these studies. Rocket engine simulator studies were conducted to evaluate the materials under simulated combustor flow conditions, in the diagnostic test chamber. These tests used the exhaust species measurement system, a device developed to monitor optically species composition and concentration in the chamber and exhaust by emission and absorption measurements.

Jassowski, Donald M.

1993-01-01

170

The Fundamental Physical Processes Producing and Controlling Stellar Coronal/ Transition-Region/Chromospheric Activity and Structure  

NASA Technical Reports Server (NTRS)

Our LTSA grant supports a long-term collaborative investigation of stellar activity. The project involves current NASA spacecraft and supporting ground-based telescopes, will make use of future missions, and utilizes the extensive archives of IUE, ROSAT, HST, and EUVE. Our interests include observational work (with a nonnegligible groundbased component); specialized processing techniques for imaging and spectral data; and semiempirical modeling, ranging from optically-thin emission measure studies to simulations of optically-thick resonance lines. Collaborations with our cool-star colleagues here in Boulder (at JILA and the High Altitude Observatory) provide access to even broader expertise, particularly on the solar corona, convection, and magnetohydrodynamic phenomena (including "dynamo" theories). The broad-brush of our investigation include the following: (1) where do coronae occur in the Hertzsprung-Russell diagram? (2) the winds of coronal stars: hot, cool, or both? (3) age, activity, rotation relations; (4) atmospheric inhomogeneities; and (5) heating mechanisms, subcoronal flows and flares. Our observation task has been to map the global properties of chromospheres and coronae in the H-R diagram and conduct detailed studies of key objects.

Ayres, Thomas R.; Brown, Alexander

1998-01-01

171

The geological processes time scale of the Ingozersky block TTG complex (Kola Peninsula)  

NASA Astrophysics Data System (ADS)

Ingozersky block located in the Tersky Terrane of the Kola Peninsula is composed of Archean gneisses and granitoids [1; 5; 8]. The Archaean basement complexes on the regional geological maps have called tonalite-trondemit-gneisses (TTG) complexes [6]. In the previous studies [1; 3; 4; 5; 7] within Ingozersky block the following types of rocks were established: biotite, biotite-amphibole, amphibole-biotite gneisses, granites, granodiorites and pegmatites [2]. In the rocks of the complex following corresponding sequence of endogenous processes observed (based on [5]): stage 1 - the biotitic gneisses formation; 2 - the introduction of dikes of basic rocks; 3 phase - deformation and foliation; 4 stage - implementation bodies of granite and migmatization; 5 stage - implementation of large pegmatite bodies; stage 6 - the formation of differently pegmatite and granite veins of low power, with and without garnet; stage 7 - quartz veins. Previous U-Pb isotopic dating of the samples was done for biotite gneisses, amphibole-biotite gneisses and biotite-amphibole gneisses. Thus, some Sm-Nd TDM ages are 3613 Ma - biotite gnesses, 2596 Ma - amphibole-biotite gnesses and 3493 Ma biotite-amphibole gneisses.. U-Pb ages of the metamorphism processes in the TTG complex are obtained: 2697±9 Ma - for the biotite gneiss, 2725±2 and 2667±7 Ma - for the amphibole-biotite gneisses, and 2727±5 Ma for the biotite-amphibole gneisses. The age defined for the biotite gneisses by using single zircon dating to be about 3149±46 Ma corresponds to the time of the gneisses protolith formation. The purpose of these studies is the age establishing of granite and pegmatite bodies emplacement and finding a geological processes time scale of the Ingozerskom block. Preliminary U-Pb isotopic dating of zircon and other accessory minerals were held for granites - 2615±8 Ma, migmatites - 2549±30 Ma and veined granites - 1644±7 Ma. As a result of the isotope U-Pb dating of the different Ingozerskogo TTG complex rocks, the following age-formation stages are determined: protolith of the biotite gneisses - 3149±46 Ma; metamorphism, deformation of rocks, foliation - 2727±5 - 2725±2 - 2697±9 - 2667±7 Ma, granite bodies formation - 2615±8 Ma and biotite gneisses migmatization - 2549±30 Ma, formation of different pegmatite and granite veins -1644±7 Ma. Author are grateful to Akad. Mitrofanov F.P. and Bayanova T.B. for the consultations. The work is supported by RFBR 12-05-31063, 11-05-00570. 1.Batieva I.D., Belkov I.V. Granitoidnie formacii Kolskogo poluostrova. // Ocgerki po petrologiy, mineralogiy i metallogeniy Kolskogo poluostrova. L.: Nauka. 1968. p. 5-143. (in russian) 2. Belkov I.V., Zagorodny V.G., Predovsky A.A. et al. Stratigraficheskoe raschlenenie i korrelyacia dokembria severo-vostochoi chasty Baltiyskogo shita. L.: Nauka. 1971. p. 141-150. (in russian) 3. Docembriskaya tektonica severo-vostochoi chasty Baltiyskogo shita (Ob'asnitelnaya zapiska k tektonicheskoi karte severo-vostochoi chasty Baltiyskogo shita 1:500000) / ed.: F.P.Mitrofanov. Apatity: KFAN SSSR. 1992. 112 P. (in russian) 4. Zagorodny V.G., Radchenko A.T. Tectonika i glubinnoe stroenie severo-vostochoi chasty Baltiyskogo shita. Apatity: KFA SSSR. 1978. p. 3-12. (in russian) 5. Kozlov N.E., Sorohtin N.O., Glaznev V.N. et al. Geologia Arhea Baltiskogo shita. S.Pb.: Nauka. 2006. 329 p. (in russian) 6. Mitrofanov F.P. Sovremennie problemy i nekotorie resheniya dokembriskoy geologii kratonov. (2001) Litosphera.2001. V 1. P. 5-14. (in russian) 7. Ob'asnitelnaya zapiska k geologicheskoy karte severo-vostochoi chasty Baltiyskogo shita 1:500000 / ed.: F.P.Mitrofanov. Apatity: KFAN SSSR. 1994. 95 P. (in russian) 8. Haritonov L.Y. Structura i stratigraphia karelid vostoka Baltiskogo shita. M.: Nedra. 1966. 354 P. (in russian)

Nitkina, Elena

2013-04-01

172

Fundamental surface processes in heterogeneous atmospheric chemistry: Applications to sea-salt (NaCl) and oxide particulate chemistry  

NASA Astrophysics Data System (ADS)

Although heterogeneous phenomena are important in many atmospheric processes, these complex systems have been difficult to study at the fundamental level. Surface- sensitive techniques are currently being utilized to probe the chemistry of heterogeneous atmospheric systems. In addition to presenting fundamental surface chemistry of several systems, this dissertation shows that surface- sensitive and electron microscopy technology can provide substantial insight into heterogeneous atmospheric processes. Transmission electron microscopy and energy dispersive spectroscopy (TEM-EDS) were used to better understand fundamental mechanisms of the reaction of sodium chloride with nitric acid vapor (and reaction with nitrogen dioxide) followed by water vapor. Results show for the first time that exposures to water vapor can lead to major reconstruction and concurrent recrystallization of the surface after reaction of NaCl(s) with HNO3(g). This has significant implications for tropospheric chemistry in polluted urban regions. The entire volume of airborne sea-salt (i.e. NaCl) particles is available for reaction due to the water-induced reorganization of the surface. Additional studies presented here include: (1) Laser induced desorption-Fourier transform mass spectrometry (LID-FTMS) studies of the reactivity of thin films of aluminum oxide (?- Al2O3/NiAl(100)) after exposure to molecules relevant to tropospheric and stratospheric particulate chemistry, (2) TEM-EDS studies of stratospheric particles, and (3) Thermal desorption spectroscopy (TDS) of CO/NiAl(100). TDS and LID-FTMS studies reveal that non-hydroxylated ?- Al2O3/NiAl(100) is inert toward the adsorption of CF2Cl2 and HCF2Cl. LID-FTMS results show that 1,3-butadiene desorbs intact from non- hydroxylated ?- Al2O3/NiAl(100) at ~200 K. The TEM-EDS studies of stratospheric particles reveal that submicron alumina spheres are amorphous. Previous studies of submicron alumina spheres showed that ?-alumina was the predominate phase of submicron spheres. In the studies published by other researchers, the amorphous-alumina structure may have been masked by small amounts of crystalline alumina phases. NiAl was initially used to grow alumina thin films; however, the surface chemistry of NiAl is also interesting due of its selective reactivity. TDS studies reveal that carbon monoxide adsorbs dissociatively and molecularly on the NiAl(100) surface.

Allen, Heather Cecile

1997-10-01

173

GIS-project: geodynamic globe for global monitoring of geological processes  

Microsoft Academic Search

A multilayer geodynamic globe at the scale 1:10,000,000 was created at the end of the nineties in the GIS Center of the Vernadsky Museum. A special soft-and-hardware complex was elaborated for its visualization with a set of multitarget object directed databases. The globe includes separate thematic covers represented by digital sets of spatial geological, geochemical, and geophysical information (maps, schemes,

V. Ryakhovsky; D. Rundquist; Yu. Gatinsky; E. Chesalova

2003-01-01

174

Fundamentals of! Image Processing!  

E-print Network

: Hoiem! Matching with filters" · Goal: find in image! · Method 2: SSD! ! Input! 1- sqrt(SSD)! Thresholded in image! · Method 2: SSD! ! Input! 1- sqrt(SSD)! 2 , )],[],[(],[ lnkmflkgnmh lk ++-= What s the potential downside of SSD?! Slide: Hoiem! SSD sensitive to average intensity! Matching with filters" · Goal: find

Erdem, Erkut

175

Fundamentals of Image Processing  

E-print Network

;Slide: Hoiem Matching with filters · Goal: find in image · Method 2: SSD Input 1- sqrt(SSD: find in image · Method 2: SSD Input 1- sqrt(SSD) 2 , )],[],[(],[ lnkmflkgnmh lk ++-= What's the potential downside of SSD? Slide: Hoiem SSD sensitive to average intensity #12;Matching with filters

Erdem, Erkut

176

Fundamentals of! Image Processing!  

E-print Network

squares! Color perception" Content © 2008 R.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp Color perception" Content © 2008 R.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp #12;Color perception" Content © 2008 R.Beau Lotto http

Erdem, Erkut

177

Fundamentals of Image Processing  

E-print Network

at yellow squares Color perception Content © 2008 R.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp #12;Color perception Content © 2008 R.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp #12;Color perception Content © 2008 R.Beau Lotto http

Erdem, Erkut

178

Fundamentals of Image Processing  

E-print Network

.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp #12;Color perception Content © 2008 R.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp #12;Color perception Content © 2008 R.Beau Lotto http://www.lottolab.org/articles/illusionsoflight.asp #12;Color perception Content © 2008 R

Erdem, Erkut

179

CO2-mineral Wettability and Implications for Understanding Leakage Processes from Geologic Carbon Sequestration Sites  

NASA Astrophysics Data System (ADS)

In geological carbon sequestration (GCS), leakage events will be difficult to predict because parcels of CO2 will travel over long length scales and encounter a number of heterogeneous formations and endogenous brine in their rise to the surface. A constitutive model of a rising parcel of CO2 includes at least three main forces: 1) buoyant forces, 2) surface tension forces, and 3) shear drag forces. Of these, surface tension forces are of great significance, especially for predicting capillary and mineral trapping, and are affected by surface tension and the three-phase contact angle between CO2, brine, and the solid host mineral surfaces. Very limited experimental data on contact angles in GCS relevant systems has been reported in the academic literature. Here, the contact angle of several of the rock and clay species prevailing near GCS sites, e.g. quartz, feldspar, calcite, kaolinite, smectite and illite, were measured under a range of relevant temperature, pressure and ionic strength conditions. The measurements were made in a custom-built high-pressure view cell by introducing precisely controlled pendant CO2 droplets of constant volume to smooth and clean mineral surfaces after saturating the surrounding brine with CO2 and images were recorded using a high resolution digital camera. Images were processed and the contact angle measured using ImageJ software with a plug-in designed for this purpose. To measure the contact angle of CO2 on clay surfaces, ultra-pure microscope glass slides were coated with cleaned and particle-size-separated clay particles using hydrolyzed polyvinyl alcohol to ensure adhesion and a continuous coating on the surface. The uniform morphology of the surface was confirmed using electron microscopy. Preliminary results demonstrate differences in contact angle between the tested minerals, with calcite > quartz > feldspar. The absolute differences between the minerals were on the order of 3-7%. The results also demonstrate that under higher temperature and pressure conditions, the contact angle decreases making the minerals more strongly wetting. For calcite, the contact angle decreases from 155.9o at 7MPa, 30oC (gas phase CO2) to 149.8o at 20MPa, 50oC (supercritical phase CO2), suggesting that contact angle is impacted by both temperature and pressure but also by CO2 phase. The contact angle measurements also indicate that some mineral surfaces can undergo surface hysteresis wherein surface reactions can result in changes in the surface energy and the contact angle. Of the minerals tested here calcite was found to be the most reactive and the contact angle changed from non-wetting to wetting over the period of several hours. The measurements reported here for pure mineral species enable the development of effective contact angles for heterogeneous materials that have undergone diagenesis are common on the surfaces of the consolidated and unconsolidated media.

Clarens, A. F.; Edwards, I.; Wang, S.

2011-12-01

180

Process and device for the determination of the characteristics of the geological formations traversed by a borehole  

SciTech Connect

A description is given of a process for determining characteristics of the geological formations traversed by a borehole, making use of a sonde by means of which the intensity of the gamma rays naturally radiated from the formations is measured. Both longitudinal and transversal acoustic waves are transmitted to the formations, their travel time and their attenuation between two receivers placed in contact with the formations are measured. By combination of the so-obtained values a resulting value is elaborated which is representative of one characteristic of the surveyed formations.

Bard, J.; Morlier, P.; Pelet, R.; Sarda, J.

1981-12-22

181

Venus: Vertical accretion of crust and depleted mantle and implications for geological history and processes  

NASA Technical Reports Server (NTRS)

Models for the vertical accretion of a basaltic crust and depleted mantle layer on Venus over geologic time predict the eventual development of a net negatively buoyant depleted mantle layer, its foundering and its remixing with the underlying mantle. The consequences of the development of this layer, its loss, and the aftermath are investigated and compared to the geologic record of Venus revealed by Magellan. The young average age of the surface of Venus (several hundred million years), the formation of the heavily deformed tessera regions, the subsequent emplacement of widespread volcanic plains, the presently low rate of volcanic activity, and impact crater population that cannot be distinguished from a completely spatially random distribution, and the small number of impact craters embayed by volcanism, are all consistent with the development of a depleted mantle layer, its relatively rapid loss followed by large-scale volcanic flooding, and its subsequent reestablishment. We outline a 'catastrophic' tectonic resurfacing model in which the foundering of the depleted mantle layer several hundred million years ago caused globally extensive tectonic deformation and obliteration of the cratering record, accompanied by upwelling of warm fertile mantle and its pressure-release melting to produce extensive surface volcanism in the following period. Venus presently appears to be characterized by a relatively thick depleted mantle layer and lithosphere reestablished over the last several hundred million years following the previous instability event inferred to have produced the tessera terrain.

Head, James W.; Parmentier, E. M.; Hess, P. C.

1994-01-01

182

Geological Survey research 1978  

USGS Publications Warehouse

This U.S. Geological Survey activities report includes a summary of 1978 fiscal year scientific and economic results accompanied by a list of geologic and hydrologic investigations in progress and a report on the status of topographic mapping. The summary of results includes: (1) Mineral and water resources, (2) Engineering geology and hydrology, (3) Regional geology, (4) Principles and processes, (5) Laboratory and field methods, (6) Topographic surveys and mapping, (7) Management of resources on public lands, (8) Land information and analysis, and (9) Investigations in other countries. Also included are lists of cooperating agencies and Geological Survey offices. (Woodard-USGS)

U.S. Geological Survey

1978-01-01

183

Geological Survey research 1976  

USGS Publications Warehouse

This U.S. Geological Survey activities report includes a summary of recent (1976 fiscal year) scientific and economic results accompanied by a list of geologic and hydrologic investigations in progress and a report on the status of topographic mapping. The summary of results includes: (1) Mineral resources, Water resources, (2) Engineering geology and hydrology, (3) Regional geology, (4) Principles and processes, (5) Laboratory and field methods, (6) Topographic surveys and mapping, (7) Management of resources on public lands, (8) Land information and analysis, and (9) Investigations in other countries. Also included are lists of cooperating agencies and Geological Survey offices. (Woodard-USGS)

U.S. Geological Survey

1976-01-01

184

Geology of Kentucky  

NSDL National Science Digital Library

This website contains geologic maps of Kentucky, with a discussion of geologic time in regards to the rocks, minerals, fossils, and economic deposits found there. There are also sections that describe strata and geologic structures beneath the surface (faults, basins, and arches), the structural processes (folding and faulting) that create stratigraphic units, the geomorphology of the state, geologic information by county, a general description of geologic time, fossil, rocks, and minerals of Kentucky, and a virtual field trip through Natural Bridges State Park. Links are provided for further information.

185

Neural sensitivity to statistical regularities as a fundamental biological process that underlies auditory learning: the role of musical practice.  

PubMed

There is increasing evidence that humans and other nonhuman mammals are sensitive to the statistical structure of auditory input. Indeed, neural sensitivity to statistical regularities seems to be a fundamental biological property underlying auditory learning. In the case of speech, statistical regularities play a crucial role in the acquisition of several linguistic features, from phonotactic to more complex rules such as morphosyntactic rules. Interestingly, a similar sensitivity has been shown with non-speech streams: sequences of sounds changing in frequency or timbre can be segmented on the sole basis of conditional probabilities between adjacent sounds. We recently ran a set of cross-sectional and longitudinal experiments showing that merging music and speech information in song facilitates stream segmentation and, further, that musical practice enhances sensitivity to statistical regularities in speech at both neural and behavioral levels. Based on recent findings showing the involvement of a fronto-temporal network in speech segmentation, we defend the idea that enhanced auditory learning observed in musicians originates via at least three distinct pathways: enhanced low-level auditory processing, enhanced phono-articulatory mapping via the left Inferior Frontal Gyrus and Pre-Motor cortex and increased functional connectivity within the audio-motor network. Finally, we discuss how these data predict a beneficial use of music for optimizing speech acquisition in both normal and impaired populations. PMID:24035820

François, Clément; Schön, Daniele

2014-02-01

186

Impact, and its implications for geology  

NASA Technical Reports Server (NTRS)

The publication of seminal texts on geology and on meteoritics in the 1790s, laid the groundwork for the emergence of each discipline as a modern branch of science. Within the past three decades, impact cratering has become universally accepted as a process that sculptures the surfaces of planets and satellites throughout the solar system. Nevertheless, one finds in-depth discussions of impact processes mainly in books on the Moon or in surveys of the Solar System. The historical source of the separation between meteoritics and geology is easy to identify. It began with Hutton. Meteorite impact is an extraordinary event acting instantaneously from outside the Earth. It violates Hutton's principles, which were enlarged upon and firmly established as fundamental to the geological sciences by Lyell. The split between meteoritics and geology surely would have healed as early as 1892 if the investigations conducted by Gilbert (1843-1918) at the crater in northern Arizona had yielded convincing evidence of meteorite impact. The 1950s and 1960s saw a burgeoning of interest in impact processes. The same period witnessed the so-called revolution in the Earth Sciences, when geologists yielded up the idea of fixed continents and began to view the Earth's lithosphere as a dynamic array of horizontally moving plates. Plate tectonics, however, is fully consistent with the geological concepts inherited from Hutton: the plates slowly split, slide, and suture, driven by forces intrinsic to the globe.

Marvin, Ursula B.

1988-01-01

187

ABOUT THE JOURNAL One of the oldest journals in geology, The Journal of Geology has  

E-print Network

ABOUT THE JOURNAL One of the oldest journals in geology, The Journal of Geology has promoted the systematic philosophical and fundamental study of geology since 1893. The Journal publishes original research across a broad range of subfields in geology, including geophysics, geochemistry, sedimentology

Mateo, Jill M.

188

3-Dimensional Mapping of Electrical Resistivity and Geological Data with Combination of CPTe Data for understanding the Fluid Transport Processes  

NASA Astrophysics Data System (ADS)

To understand the hydrogeological process and spatial distribution of contamination, there are several conventional methods which are gathered under two main branches that are invasive and non-invasive techniques. Standard Penetration Test and Conic Penetration Test techniques are called as classical borehole techniques and they are accepted among the invasive or less-invasive techniques. On the other hand, electrical and electromagnetic based Electrical Resistivity Tomography and Ground Penetrating Radar, most widely used techniques in imaging the subsurface in the last decade, are called as non-invasive geophysical methods. 3D electrical resistivity distribution provides information about water flow and changes in electrical resistivity of the pore fluid. Therefore, to assist in understanding and modeling of the fluid transport process, 3D spatial distribution of the electrical resistivity data with the corresponded 3D geological section were mapped and interpreted in the test site located in western Germany.

Kanli, A. I.; Nyari, Z.; Stickel, J.; Tillmann, A.

2012-12-01

189

Fall 2014 -Fundamentals of Research Geology 5020  

E-print Network

student presentations. These include a resume; a chalk talk on any scientific topic that will be video and edited by Erin Campbell-Stone. Oct 14-23 ­ Chalk Talk. This is an informal talk (10 minutes plus 2%) · Chalk talk (15%) ­ peer reviewed · Poster (15%) ­ peer reviewed · Detailed proposal outline (5

Heller, Paul

190

Determining the rates of geological processes in a large-scale metamorphic complex: a multi-method approach  

NASA Astrophysics Data System (ADS)

Metamorphic complexes occur at the Earth's surface in many places all over the world. The combined application of different geochronological and thermochronological techniques may help to constrain the rates of geological processes which led to the formation of such metamorphic belts. In this contribution we present the results of a multi-method approach aimed at constraining the timing of burial, heating, partial melting, cooling and exhumation of the Chugach Metamorphic Complex (CMC) of southern Alaska. The CMC is a large scale (ca. 300x50 km) upper amphibolite facies complex developed in an extreme forearc position in a Late Cretaceous to Paleocene accretionary prism. We present (1) U-Pb LA-ICP-MS ages of detrital zircons from the complex, which constrain the depositional age of the sedimentary rocks in which the complex developed to ~60-65 Ma, (2) U-Pb SHRIMP ages of monazite and zircon, linked by geochemical and textural analyses to the metamorphic history of the rocks, which constrain the timing of heating, peak metamorphism and partial melting to only ~3 Ma at ~54-51 Ma, and (3) 40Ar/39Ar plateau ages of muscovite and biotite as well as zircon fission track ages, which constrain the timing of cooling and exhumation to ~50-25 Ma. Combined with thermobarometry and pseudosection modelling conducted on the same samples, these radiometric ages reveal a surprisingly short metamorphic cycle: sedimentation followed by heating and burial to ~650-700°C and ~8-10 kbar occurred over a short time period of ~5-10 Ma, and cooling down to ~350°C occurred at least in the western part of the complex over a period of ~5-8 Ma. These results can be used to calculate rates of geological processes: heating rates are in the order of ~60-140°C/Ma, and cooling rates vary from ~30- 180°C/Ma in the west to 6-10°C/Ma in the southeast of the complex. Burial and exhumation rates are more difficult to constrain and depend on the pressure distribution throughout the crustal column during metamorphism, but vary between 0.5-10 mm/a. Whereas the peak metamorphic conditions are consistent with conductive heating in a regional metamorphic cycle, the high rates of heating and cooling are harder to reconcile with such processes. Advective mechanisms involving the transport of mass and/or heat are likely to have been involved. These data demonstrate the usefulness of combining different geochronological methods for determining rates and mechanisms of geological processes on a regional scale.

Gasser, D.; Bruand, E.; Stuewe, K.; Rubatto, D.; Kloetzli, U. S.; Foster, D. A.

2010-12-01

191

Preliminary paper - Integrated control process for the development of the mined geologic disposal system  

SciTech Connect

The US Department of Energy (DOE) Order 430.1, Life Cycle Asset Management, begins to focus DOE Programs and Projects on the total system life cycle instead of looking at project execution or operation as individual components. As DOE begins to implement this order, the DOE Management and Operating contractors must develop a process to control not only the contract baseline but also the overall life cycle baseline. This paper presents an integrated process that is currently being developed on the Yucca Mountain Project for DOE. The process integrates the current contract/project baseline management process with the management control process for design and the configuration management change control process.

Daniel, Russell B.; Harbert, Kevin R.; Calloway, David E.

1997-11-26

192

GIS-project: geodynamic globe for global monitoring of geological processes  

NASA Astrophysics Data System (ADS)

A multilayer geodynamic globe at the scale 1:10,000,000 was created at the end of the nineties in the GIS Center of the Vernadsky Museum. A special soft-and-hardware complex was elaborated for its visualization with a set of multitarget object directed databases. The globe includes separate thematic covers represented by digital sets of spatial geological, geochemical, and geophysical information (maps, schemes, profiles, stratigraphic columns, arranged databases etc.). At present the largest databases included in the globe program are connected with petrochemical and isotopic data on magmatic rocks of the World Ocean and with the large and supperlarge mineral deposits. Software by the Environmental Scientific Research Institute (ESRI), USA as well as ArcScan vectrorizator were used for covers digitizing and database adaptation (ARC/INFO 7.0, 8.0). All layers of the geoinformational project were obtained by scanning of separate objects and their transfer to the real geographic co-ordinates of an equiintermediate conic projection. Then the covers were projected on plane degree-system geographic co-ordinates. Some attributive databases were formed for each thematic layer, and in the last stage all covers were combined into the single information system. Separate digital covers represent mathematical descriptions of geological objects and relations between them, such as Earth's altimetry, active fault systems, seismicity etc. Some grounds of the cartographic generalization were taken into consideration in time of covers compilation with projection and co-ordinate systems precisely answered a given scale. The globe allows us to carry out in the interactive regime the formation of coordinated with each other object-oriented databases and thematic covers directly connected with them. They can be spread for all the Earth and the near-Earth space, and for the most well known parts of divergent and convergent boundaries of the lithosphere plates. Such covers and time series reflect in diagram form a total combination and dynamics of data on the geological structure, geophysical fields, seismicity, geomagnetism, composition of rock complexes, and metalloge-ny of different areas on the Earth's surface. They give us possibility to scale, detail, and develop 3D spatial visualization. Information filling the covers could be replenished as in the existing so in newly formed databases with new data. The integrated analyses of the data allows us more precisely to define our ideas on regularities in development of lithosphere and mantle unhomogeneities using some original technologies. It also enables us to work out 3D digital models for geodynamic development of tectonic zones in convergent and divergent plate boundaries with the purpose of integrated monitoring of mineral resources and establishing correlation between seismicity, magmatic activity, and metallogeny in time-spatial co-ordinates. The created multifold geoinformation system gives a chance to execute an integral analyses of geoinformation flows in the interactive regime and, in particular, to establish some regularities in the time-spatial distribution and dynamics of main structural units in the lithosphere, as well as illuminate the connection between stages of their development and epochs of large and supperlarge mineral deposit formation. Now we try to use the system for prediction of large oil and gas concentration in the main sedimentary basins. The work was supported by RFBR, (grants 93-07-14680, 96-07-89499, 99-07-90030, 00-15-98535, 02-07-90140) and MTC.

Ryakhovsky, V.; Rundquist, D.; Gatinsky, Yu.; Chesalova, E.

2003-04-01

193

USGS: Geology in the Parks  

NSDL National Science Digital Library

The US Geological Survey Geology in the Parks Web site is a cooperative project of the USGS Western Earth Surface Processes Team and the National Park Service. This extensive site covers geologic maps, plate tectonics, rocks and minerals, geologic time, US geologic provinces, park geology of the Mojave, Sunset Crater, Lake Mead, North Cascades, Death Valley, Yosemite National Park, and much more. Descriptions, graphics, photographs, and animations all contribute to this informative and interesting Web site making it a one stop, all encompassing, resource for everything geology and US national park related.

194

High-performance computer simulation of wave processes in geological media in seismic exploration  

NASA Astrophysics Data System (ADS)

A class of problems arising in seismic exploration are investigated, namely, seismic signal propagation in multilayered geological rock and near-surface disturbance propagation in massive rock with heterogeneities, such as empty or filled fractures and cavities. Numerical solutions are obtained for wave propagation in such highly heterogeneous media, including those taking into account the plastic properties of the rock, which can be manifested near a seismic gap or a wellbore. All types of explosion-generated elastic and elastoplastic waves and waves reflected from fractures and the boundaries of the integration domain are analyzed. The identification of waves in seismograms recorded with near-surface receivers is addressed. The grid-characteristic method is used on triangular, parallelepipedal, and tetrahedral meshes with boundary conditions set on the rock-fracture interface and on free surfaces in explicit form. The numerical method proposed is suitable for the study of the interaction between seismic waves and heterogeneous inclusions, since it ensures the most correct design of computational algorithms on the boundaries of the integration domain and at media interfaces. A parallel software code implemented with the help of OpenMP and MPI was used to execute computations on parallelepipedal and tetrahedral grids.

Kvasov, I. E.; Petrov, I. B.

2012-02-01

195

Thermal Conduction - A Tool for Exploring Geological Processes on the Earth and Other Bodies in our Solar System  

NSDL National Science Digital Library

Thermal conduction is a fundamental physical process, one which controls many aspects of the volcanic and tectonic evolution of bodies within our solar system. Using transmission of thermal energy through the crust of the Earth as an initial, physically intuitive conceptual model, the module's background material will (a) help students deduce the thermal conduction equation-a second order differential which can be constructed from first principles, (b) evaluate volume-adjusted conduction incorporating internal heat generation and temperature change, and (c) explore special forms of the equation such as steady state conduction and thermal diffusion.

Eric Grosfils

196

Limitations on squeezing and formation of the superposition of two macroscopically distinguishable states at fundamental frequency in the process of second harmonic generation  

NASA Technical Reports Server (NTRS)

The results of numerical simulations of quantum state evolution in the process of second harmonic generation (SHG) are discussed. It is shown that at a particular moment of time in the fundamental mode initially coherent state turns into a superposition of two macroscopically distinguished states. The question of whether this superposition exhibits quantum interference is analyzed.

Nikitin, S. P.; Masalov, A. V.

1992-01-01

197

Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry  

SciTech Connect

The fundamental and practical aspects are described for extracting ions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (T{sub e}) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (n{sub e}) is in the range 10{sup 8}--10{sup 10} {sup {minus}cm }at the skimmer tip and drops abruptly to 10{sup 6}--10{sup 8} cm{sup {minus}3} near the skimmer tip and drops abruptly to 10{sup 6}--10{sup 8} cm{sup {minus}3} downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ion beam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 10{sup 4}--10{sup 5} downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z{sup 2} intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z{sup 2} fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument.

Niu, Hongsen

1995-02-10

198

Constructing a Geology Ontology Using a Relational Database  

NASA Astrophysics Data System (ADS)

In geology community, the creation of a common geology ontology has become a useful means to solve problems of data integration, knowledge transformation and the interoperation of multi-source, heterogeneous and multiple scale geological data. Currently, human-computer interaction methods and relational database-based methods are the primary ontology construction methods. Some human-computer interaction methods such as the Geo-rule based method, the ontology life cycle method and the module design method have been proposed for applied geological ontologies. Essentially, the relational database-based method is a reverse engineering of abstracted semantic information from an existing database. The key is to construct rules for the transformation of database entities into the ontology. Relative to the human-computer interaction method, relational database-based methods can use existing resources and the stated semantic relationships among geological entities. However, two problems challenge the development and application. One is the transformation of multiple inheritances and nested relationships and their representation in an ontology. The other is that most of these methods do not measure the semantic retention of the transformation process. In this study, we focused on constructing a rule set to convert the semantics in a geological database into a geological ontology. According to the relational schema of a geological database, a conversion approach is presented to convert a geological spatial database to an OWL-based geological ontology, which is based on identifying semantics such as entities, relationships, inheritance relationships, nested relationships and cluster relationships. The semantic integrity of the transformation was verified using an inverse mapping process. In a geological ontology, an inheritance and union operations between superclass and subclass were used to present the nested relationship in a geochronology and the multiple inheritances relationship. Based on a Quaternary database of downtown of Foshan city, Guangdong Province, in Southern China, a geological ontology was constructed using the proposed method. To measure the maintenance of semantics in the conversation process and the results, an inverse mapping from the ontology to a relational database was tested based on a proposed conversation rule. The comparison of schema and entities and the reduction of tables between the inverse database and the original database illustrated that the proposed method retains the semantic information well during the conversation process. An application for abstracting sandstone information showed that semantic relationships among concepts in the geological database were successfully reorganized in the constructed ontology. Key words: geological ontology; geological spatial database; multiple inheritance; OWL Acknowledgement: This research is jointly funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China (RFDP) (20100171120001), NSFC (41102207) and the Fundamental Research Funds for the Central Universities (12lgpy19).

Hou, W.; Yang, L.; Yin, S.; Ye, J.; Clarke, K.

2013-12-01

199

Site selection and characterization processes for deep geologic disposal of high level nuclear waste  

SciTech Connect

In this paper, the major elements of the site selection and characterization processes used in the US high level waste program are discussed. While much of the evolution of the site selection and characterization processes have been driven by the unique nature of the US program, these processes, which are well defined and documented, could be used as an initial basis for developing site screening, selection, and characterization programs in other countries. Thus, this paper focuses more on the process elements than the specific details of the US program.

Costin, L.S.

1997-10-01

200

The effects of CO2-brine rheology on leakage processes in geologic carbon sequestration  

NASA Astrophysics Data System (ADS)

Leakage from geologic carbon sequestration (GCS) sites is inherently challenging to study because CO2, driven by buoyant forces, travels over long distances, undergoing phase changes and encountering numerous connate brine and formation chemistries as it rises to the surface. This work explores the effect that CO2has on the rheological properties of brine solutions over a range of GCS-relevant temperature, pressure, ionic strength, and shear conditions. Under the fluid-liquid equilibrium conditions that prevail in the deep subsurface, viscosity of CO2-brine mixtures was found to be a function of temperature and pressure alone. Once leakage conditions ensue, discrete CO2bubbles form in brine, resulting in the vapor-liquid equilibrium (VLE), and these mixtures exhibit complex linear viscoelastic, time dependent, and thixotropic behavior. The presence of CO2(g) bubbles on the flow of the bulk fluid could have important impacts on impeding (via shear drag force) leakage depending on the geometrical, geochemical and geophysical characteristics of a storage site. Under VLE conditions, the effective viscosity of CO2-brine mixtures was found to be up to five times higher than brine alone but the microstructure was easily destroyed, and not readily regained, under high shear conditions. At higher temperatures and higher ionic strength, the effect is less pronounced. These results were considered in the context of flow through porous media, and the effect on buoyancy-driven flow is significant. Understanding this effect is important for developing an accurate constitutive relationship for leaking CO2, which will lead to better capacity to select and monitor GCS sites.

Wang, Shibo; Clarens, Andres F.

2012-08-01

201

Geologic Explorations  

NSDL National Science Digital Library

Geologic Explorations allows learners to explore a variety of unique geological formations of Utah using Quicktime Virtual Reality (QTVR) panoramas and digital still imagery. Spectacular panoramas and striking images capture Utah's unique geology and invite students to explore and learn interesting facts and concepts central to the study of geology.

Alec Bodzin

2002-04-01

202

Statistical pre-processing and analyses of hydro-meteorological time series in a geologic clay site (methodology and first results for Mont Terri’s PP experiment)  

NASA Astrophysics Data System (ADS)

This article presents a set of statistical methods for pre-processing (or pre-conditioning) and analyzing multivariate hydro-geologic time series, such as pore pressures and atmospheric pressure (temporal structures). The pre-processing methods are necessary to enhance or complete the signals due to defects in the observed time series (data gaps, spurious values, variable time steps). The statistical analyses aim, in fine, at characterizing the hydraulic behaviour of a clayey formation in the context of deep geologic disposal of radioactive waste. Pore water and atmospheric pressure time series from the Mont Terri rock laboratory (BPP-1 borehole) are taken as an example.

Fatmi, H.; Ababou, R.; Matray, J. M.

203

Geology of the Colorado Plateau  

NSDL National Science Digital Library

This web page provides a general description of the geology of the Colorado Plateau. Topics include information about the various geologic environments and processes active during the Precambrian and the Paleozoic, Mesozoic and Cenozoic Eras.

Colorado Plateau Field Institute

204

In Situ Optical Observation of High-Temperature Geological Processes With the Moissanite Cell  

Microsoft Academic Search

A major drawback of existing techniques in experimental earth and material sciences is the inability to observe ongoing high-temperature processes in situ during an experiment. Examples for important time-dependent processes include the textural development of rocks and oxide systems during melting and crystallization, solid-state and melt-present recrystallization and Ostwald ripening, and bubble nucleation and growth during degassing of glasses and

N. Walte; H. Keppler

2005-01-01

205

Development of multiple source data processing for structural analysis at a regional scale. [digital remote sensing in geology  

NASA Technical Reports Server (NTRS)

Various image processing techniques developed for enhancement and extraction of linear features, of interest to the structural geologist, from digital remote sensing, geologic, and gravity data, are presented. These techniques include: (1) automatic detection of linear features and construction of rose diagrams from Landsat MSS data; (2) enhancement of principal structural directions using selective filters on Landsat MSS, Spacelab panchromatic, and HCMM NIR data; (3) directional filtering of Spacelab panchromatic data using Fast Fourier Transform; (4) detection of linear/elongated zones of high thermal gradient from thermal infrared data; and (5) extraction of strong gravimetric gradients from digitized Bouguer anomaly maps. Processing results can be compared to each other through the use of a geocoded database to evaluate the structural importance of each lineament according to its depth: superficial structures in the sedimentary cover, or deeper ones affecting the basement. These image processing techniques were successfully applied to achieve a better understanding of the transition between Provence and the Pyrenees structural blocks, in southeastern France, for an improved structural interpretation of the Mediterranean region.

Carrere, Veronique

1990-01-01

206

Results From an International Simulation Study on Couples Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories  

SciTech Connect

As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.

J. Rutqvist; D. Barr; J.T. Birkholzer; M. Chijimatsu; O. Kolditz; Q. Liu; Y. Oda; W. Wang; C. Zhang

2006-08-02

207

YOUNG GEOLOGY GEOLOGY OF THE  

E-print Network

YOUNG GEOLOGY UNIVERSITY May, 1962 GEOLOGY OF THE SOUTHERN WASATCH MOUNTAINS AND VICIN~IM,UTAH C O ....................J. Keith Rigby 80 Economic Geology of North-Central Utah ...,............... Kcnneth C.Bdodc 85 Rod Log ........................Lehi F. Hintze, J. Ka# Ri&, & ClydeT. Hardy 95 Geologic Map of Southern

Seamons, Kent E.

208

Deposits related to degradation processes on Piton des Neiges Volcano (Reunion Island): overview and geological hazard  

NASA Astrophysics Data System (ADS)

Piton des Neiges (PN) Volcano on Reunion Island offers a rare opportunity to study deposits related to degradation processes in a deeply eroded oceanic shield volcano. Both the inner parts and flanks reveal a large amount of resedimented volcaniclastic material, including extensive debris avalanche deposits. PN litho-structural units, first studied by Upton and Wadsworth [1965, Philos. Trans. R. Soc. Lond., A 271, pp. 105-130], are re-examined. This review highlights the importance of long volcanic repose periods and erosion processes during PN history. volcaniclastic deposits have been studied in the field in order to evaluate the spatial and temporal distribution of the three main types of PN degradation processes. The deposits of these processes have been classified into: (1) talus, (2) mudflow and debris flow, and (3) debris avalanche. Lithology, frequency and estimated volumes of each deposit type imply that the structural evolution of PN can be considered in terms of the competition between the volcanic productivity and the degradation and erosion processes. The occurrence of huge catastrophic avalanches produced by flank failure is convincingly linked to the basaltic activity of PN, which implies a very low risk at present. On the contrary, mudflows and debris flows pose an important risk due to the high population density focussed around the basin outlets. Moreover, if smaller debris avalanches can occur in the cirques of PN, another major risk must be evaluated.

Bret, Laurent; Fevre, Yannick; Join, Jean-Lambert; Robineau, Bernard; Bachelery, Patrick

2003-04-01

209

Collaborative web-based annotation of video footage of deep-sea life, ecosystems and geological processes  

NASA Astrophysics Data System (ADS)

More and more seagoing scientific expeditions use video-controlled research platforms such as Remote Operating Vehicles (ROV), Autonomous Underwater Vehicles (AUV), and towed camera systems. These produce many hours of video material which contains detailed and scientifically highly valuable footage of the biological, chemical, geological, and physical aspects of the oceans. Many of the videos contain unique observations of unknown life-forms which are rare, and which cannot be sampled and studied otherwise. To make such video material online accessible and to create a collaborative annotation environment the "Video Annotation and processing platform" (V-App) was developed. A first solely web-based installation for ROV videos is setup at the German Center for Marine Environmental Sciences (available at http://videolib.marum.de). It allows users to search and watch videos with a standard web browser based on the HTML5 standard. Moreover, V-App implements social web technologies allowing a distributed world-wide scientific community to collaboratively annotate videos anywhere at any time. It has several features fully implemented among which are: • User login system for fine grained permission and access control • Video watching • Video search using keywords, geographic position, depth and time range and any combination thereof • Video annotation organised in themes (tracks) such as biology and geology among others in standard or full screen mode • Annotation keyword management: Administrative users can add, delete, and update single keywords for annotation or upload sets of keywords from Excel-sheets • Download of products for scientific use This unique web application system helps making costly ROV videos online available (estimated cost range between 5.000 - 10.000 Euros per hour depending on the combination of ship and ROV). Moreover, with this system each expert annotation adds instantaneous available and valuable knowledge to otherwise uncharted material.

Kottmann, R.; Ratmeyer, V.; Pop Ristov, A.; Boetius, A.

2012-04-01

210

The importance of both geological and pedological processes in control of grain size and sedimentation rates in Peoria Loess  

USGS Publications Warehouse

The loess-paleosol succession in the Peoria Loess in southern Illinois is characterized as alternating loess layers and weathering bands, known as paleosol A horizons. The fast loess accumulation during the late Wisconsin glaciation interacted with the incipient pedogenesis and caused unclear boundaries of loess-paleosol alternations in soil horizonation and mineralogy. Parameters of grain size distribution, sedimentation rate, matrix carbonate content and diffuse reflectance (i.e. soil colors and iron oxides) are used in this paper to discuss the geological and pedological influences for the Peoria Loess in Keller Farm section in southern Illinois. The multi-proxy analysis revealed that many paleosol A horizons, defined by the diffuse reflectance variability, contain finer-grained materials with a relatively higher sedimentation rate. It suggests that glaciofluvial sediments were available in the source areas for uploading eolian dust during the temporary ice sheet retreats. The denser vegetation and wetter surface soils on the loess deposit area could increase the dust trapping efficiency and caused a greater accumulation rate of loess deposits. The coarser-grained materials and slower sedimentation rate are often found in loess layers. It suggests that strong surface winds transported the coarser-grained materials from local dust sources and sparse vegetation and dry surface soils reduced the dust trapping efficiency during the ice sheet readvance. The strong interactions between the geological and pedological processes played an important role on the loess-paleosol alternations in southern Illinois during the late Wisconsin glaciation. ?? 2006 Elsevier B.V. All rights reserved.

Wang, H.; Mason, J.A.; Balsam, W.L.

2006-01-01

211

Geological Survey research 1981  

USGS Publications Warehouse

This U.S. Geological Survey activities report includes a summary of 1981 fiscal year scientific and economic results accompanied by a list of geologic, hydrologic, and cartographic investigations in progress. The summary of results includes: (1) Mineral, (2) Water resources, (3) Engineering geology and hydrology, (4) Regional geology, (5) Principles and processes, (6) Laboratory and field methods, (7) Topographic surveys and mapping, (8) Management of resources on public lands, (9) Land information and analysis, and (10) Investigations in other countries. Also included are lists of investigations in progress. (USGS)

U.S. Geological Survey

1982-01-01

212

Geologic characterization of shelf areas using usSEABED for GIS mapping, modeling processes and assessing marine sand and gravel resources  

USGS Publications Warehouse

Geologic maps depicting offshore sedimentary features serve many scientific and applied purposes. Such maps have been lacking, but recent computer technology and software offer promise in the capture and display of diverse marine data. Continental margins contain landforms which provide a variety of important functions and contain important sedimentary records. Some shelf areas also contain deposits regarded as potential aggregate resources. Because proper management of coastal and offshore areas is increasingly important, knowledge of the framework geology and marine processes is critical. Especially valuable are comprehensive and integrated digital databases based on high-quality information from original sources. Products of interest are GIS maps containing thematic information, such as sediment character and texture. These products are useful to scientists modeling nearshore and shelf processes as well as planners and managers. The U.S. Geological Survey is leading a national program to gather a variety of extant marine geologic data into the usSEABED database system. This provides centralized, integrated marine geologic data collected over the past 50 years. To date, over 340,000 sediment data points from the U.S. reside in usSEABED, which combines an array of physical data and analytical and descriptive information about the sea floor and are available to the marine community through three USGS data reports for the Atlantic, Gulf of Mexico, and Pacific published in 2006, and the project web sites: (http://woodshole.er.usg s.gov/project-pages/aggregates/ and http://walrus.wr.usgs.gov/usseabed/)

Williams, S.J.; Bliss, J.D.; Arsenault, M.A.; Jenkins, C.J.; Goff, J.A.

2007-01-01

213

The Large Impact Process Inferred from the Geology of Lunar Multiring Basins  

NASA Technical Reports Server (NTRS)

The study of the geology of multiring impact basins on the Moon over the past ten years has given us a rudimentary understanding of how these large structures have formed and evolved on the Moon and other bodies. Two-ring basins on the Moon begin to form at diameters of about 300 km; the transition diameter at which more than two rings appear is uncertain, but it appears to be between 400 and 500 km in diameter. Inner rings tend to be made up of clusters or aligned segments of massifs and are arranged into a crudely concentric pattern; scarp-like elements may or may not be present. Outer rings are much more scarp-like and massifs are rare to absent. Basins display textured deposits, interpreted as ejecta, extending roughly an apparent basin radius exterior to the main topographic rim. Ejecta may have various morphologies, ranging from wormy and hummocky deposits to knobby surfaces; the causes of these variations are not known, but may be related to the energy regime in which the ejecta are deposited. Outside the limits of the textured ejecta are found both fields of satellitic craters (secondaries) and light plains deposits. Impact melt sheets are observed on the floors of relatively unflooded basins. Samples of impact melts from lunar basins have basaltic major-element chemistry, characterized by K, rare-earth elements (REE), P, and other trace elements of varying concentration (KREEP); ages are between 3.8 and 3.9 Ga. These lithologies cannot be produced through the fusion of known pristine (plutonic) rock types, suggesting the occurrence of unknown lithologies within the Moon. These melts were probably generated at middle to lower crustal levels. Ejecta compositions, preservation of pre-basin topography, and deposit morphologies all indicate that the excavation cavity of multiring basins is between about 0.4 and 0.6 times the diameter of the apparent crater diameter. Basin depths of excavation can be inferred from the composition of basin ejecta. A variety of mechanisms has been proposed to account for the formation of basin rings but none of them are entirely plausible. Mechanisms can be divided into two broad groups: (1) forcible uplift due to fluidization of the target; (2) concentric, brittle, fracturing and failure of the target, on regional (megaterraces) to global scales (lithospheric fracturing). Most basin rings are spaced at a constant factor on all planets. Evidence supports divergent ringforming models, so it may be that the ring-locating mechanism differs from the ring-forming mechanism. Thus, large-scale crustal foundering (megaterracing) could occur along concentric zones of weakness created by some type of resonant wave mechanism (fluidization and uplift); such immediate crustal adjustment could then be followed by long-term adjustment of the fractured lithosphere.

Spudis, Paul D.

1994-01-01

214

Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

Described are several aspects and methods of quantitatively measuring geologic time using a constant-rate natural process of radioactive decay. Topics include half lives and decay constants, radiogenic growth, potassium-argon dating, rubidium-strontium dating, and the role of geochronology in support of geological exploration. (DS)

Pankhurst, R. J.

1980-01-01

215

Layer Cake Geology  

NSDL National Science Digital Library

This classroom activity uses a cake to demonstrate geologic processes and introduce geologic terms. Students will learn how folds and faults occur, recognize the difference in behavior between brittle and ductile rocks, and attempt to predict structures likely to result from application of various forces to layered rocks. They will also attempt to interpret 'core samples' to determine subsurface rock structure.

John Wagner

216

On geological processes on venus: Analysis of the relationship between altitude and degree of surface roughness  

Microsoft Academic Search

Aiming to study the relationship between Venus surface heights and surface roughness, the Pioneer Venus surface altitude map and map of r.m.s. slope in m-dkm scale have been analy sed for the Beta and Ishtar regions using a system of digital image processing. To integrate the data obtained, the results of geomorphological analysis of Venera 9 and 10 TV panoramas

A. T. Bazilevski; N. N. Bobina; V. P. Shashkina; Yu. G. Shkuratov; Yu. V. Kornienko; A. Ya. Usikov; D. G. Stankevich

1982-01-01

217

Experience of the application of a database of generic Features, Events and Processes (FEPs) targeted at geological storage of CO 2  

Microsoft Academic Search

This paper reviews the application of a freely accessible on-line database of generic Features, Events and Processes (FEPs), designed to support the analysis of geological CO2 storage systems during performance assessments. The Generic CO2 FEP Database was established by Quintessa in 2004 through international collaboration under the auspices of the Weyburn project. Subsequently, development of the database has continued and

Russell Walke; Richard Metcalfe; Laura Limer; Philip Maul; Alan Paulley; David Savage

2011-01-01

218

Capacitor fundamentals  

Microsoft Academic Search

In this review of capacitor fundamentals, the author attempts to clarify the modes of operation of the broad spectrum of capacitors, including paper\\/polymeric films, electrolytics, and ceramics. How each class of capacitor performs in both low- and high-power electronics is discussed in detail, with emphasis upon delineating those factors affecting life, reliability, maintainability, and environmental compatibility of systems in which

W. J. Sarjeant; James Clerk Maxwell

1989-01-01

219

In Situ Optical Observation of High-Temperature Geological Processes With the Moissanite Cell  

NASA Astrophysics Data System (ADS)

A major drawback of existing techniques in experimental earth and material sciences is the inability to observe ongoing high-temperature processes in situ during an experiment. Examples for important time-dependent processes include the textural development of rocks and oxide systems during melting and crystallization, solid-state and melt-present recrystallization and Ostwald ripening, and bubble nucleation and growth during degassing of glasses and melts. The investigation of these processes by post-mortem analysis of a quenched microstructure is time consuming and often unsatisfactory. Here, we introduce the moissanite cell that allows optical in situ observation of long-term experiments at high temperatures. Moissanite is a transparent gem-quality type of SiC that is characterized by its hardness and superior chemical and thermal resistance. Two moissanite windows with a thickness and diameter of several millimeters are placed into sockets of fired pyrophyllite and fixed onto two opposite metal plates. The sockets are wrapped with heating wire and each window is connected to a thermocouple for temperature control. The sample is placed directly between the moissanite windows and the cell is assembled similarly to a large diamond anvil cell. In situ observation of the sample is done with a microscope through observation windows and movies are recorded with an attached digital camera. Our experiments with the new cell show that temperatures above 1200°C can be maintained and observed in a sample for several days without damaging the cell nor the windows. Time-lapse movies of melting and crystallizing natural and synthetic rocks and of degassing glasses and melts will be presented to show the potential of the new technique for experimental earth and material science.

Walte, N.; Keppler, H.

2005-12-01

220

Insights into Titan's geology and hydrology based on enhanced image processing of Cassini RADAR data  

NASA Astrophysics Data System (ADS)

The Cassini Synthetic Aperture Radar has been acquiring images of Titan's surface since October 2004. To date, 59% of Titan's surface has been imaged by radar, with significant regions imaged more than once. Radar data suffer from speckle noise hindering interpretation of small-scale features and comparison of reimaged regions for change detection. We present here a new image analysis technique that combines a denoising algorithm with mapping and quantitative measurements that greatly enhance the utility of the data and offers previously unattainable insights. After validating the technique, we demonstrate the potential improvement in understanding of surface processes on Titan and defining global mapping units, focusing on specific landforms including lakes, dunes, mountains, and fluvial features. Lake shorelines are delineated with greater accuracy. Previously unrecognized dissection by fluvial channels emerges beneath shallow methane cover. Dune wavelengths and interdune extents are more precisely measured. A significant refinement in producing digital elevation models is shown. Interactions of fluvial and aeolian processes with topographic relief is more precisely observed and understood than previously. Benches in bathymetry are observed in northern sea Ligeia Mare. Submerged valleys show similar depth suggesting that they are equilibrated with marine benches. These new observations suggest a liquid level increase in the northern sea, which may be due to changes on seasonal or longer timescales.

Lucas, Antoine; Aharonson, Oded; Deledalle, Charles; Hayes, Alexander G.; Kirk, Randolph; Howington-Kraus, Elpitha

2014-10-01

221

Genesis of karren in Kentucky Lake, Tennessee: Interaction of geologic structure, weathering processes, and bioerosion  

SciTech Connect

While karst features formed along marine coastlines are commonly reported, shoreline karst features produced within lacustrine systems have received little attention. The shoreline of Bond Island'' in Kentucky Lake has evolved a distinctive karren geomorphology not recognized elsewhere in the lake. The karren consist of well-developed clint and grike topography, trench formation, solution pits, flutes, and runnels, and pit and tunnel development. Two processes are responsible for the karren. First, freshwater dissolution and wave action on structurally fractured Decatur Limestone (Silurian) mechanically and chemically weaken the entire exposed surface. Second, a seasonal cycle of winter freeze-thaw and frost wedging followed by spring bioerosion overprints the first set of processes. Bioerosion by chemical dissolution involving a complex association of predominantly chironomids, algae, fungi, and bryozoa results in preferential dissolution along joints, stylolites, and bedding planes to form shallow spindle-shaped solution pits over the entire surface and sides of the karren. The solution pits average 1 cm length by 0.4 cm depth densely covering rock surfaces. This study suggests that seasonal bioerosion may constitute a more important geomorphic factor in lacustrine systems than previously recognized.

Gibson, M.A.; Smith, W.L. (Univ. of Tennessee, Martin, TN (United States))

1993-03-01

222

Geologic nozzles  

NASA Astrophysics Data System (ADS)

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low characteristic velocities of geologic fluids has not been widely recognized and, as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid-flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, supercritical flow occurs where debris discharged from tributary canyons constricts the channel into the shape of a converging-diverging nozzle. The geometry of the channel in these regions can be used to interpret the flood history of the Colorado River over the past 103-105 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

Kieffer, Susan Werner

223

Geologic Nozzles  

NASA Astrophysics Data System (ADS)

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the gyeser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. The transport capacity in the rapids can be so great that the river contours the channel to a characteristic shape. This shape can be used to interpret the flood history of the Colorado River over the past 10³-105 years. The unity of fluid mechanics in these three natural phenomena is provided by the well-known analogy between gas flow and shallow-water flow in converging-diverging nozzles.

Kieffer, Susan Werner

1989-02-01

224

Arguments for fundamental emission by the parametric process L yields T + S in interplanetary type III bursts. [langmuir, electromagnetic, ion acoustic waves (L, T, S)  

NASA Technical Reports Server (NTRS)

Observations of low frequency ion acoustic-like waves associated with Langmuir waves present during interplanetary Type 3 bursts are used to study plasma emission mechanisms and wave processes involving ion acoustic waves. It is shown that the observed wave frequency characteristics are consistent with the processes L yields T + S (where L = Langmuir waves, T = electromagnetic waves, S = ion acoustic waves) and L yields L' + S proceeding. The usual incoherent (random phase) version of the process L yields T + S cannot explain the observed wave production time scale. The clumpy nature of the observed Langmuir waves is vital to the theory of IP Type 3 bursts. The incoherent process L yields T + S may encounter difficulties explaining the observed Type 3 brightness temperatures when Langmuir wave clumps are incorporated into the theory. The parametric process L yields T + S may be the important emission process for the fundamental radiation of interplanetary Type 3 bursts.

Cairns, I. H.

1984-01-01

225

Antarctic Dry Valleys: Geological Processes in Hyperarid, Hypothermal Environments and Implications for Water on Mars  

NASA Astrophysics Data System (ADS)

The Antarctic Dry Valleys (ADV) are characterized by mean annual temperatures (MAT) well below the freezing point of water and are among the coldest and driest environments on Earth. In spite of these extreme conditions, seasonal temperatures (ST) and peak daytime temperatures (PDT) can locally exceed the melting point of water in certain settings in certain microenvironments. Three major microenvironments (upland stable zone, inland mixed zone, coastal thaw zone) are defined in the ADV on the basis of measurements of atmospheric temperatures (MAT/ST), soil moisture and relative humidity, and the concurrent availability and mobility of water; these microenvironments show variations in the abundance and character of different geomorphic features. For example, in the coldest upland stable zone melting is almost non-existent and sublimation polygons dominate; ice-wedge polygons occur in the coastal thaw zone where seasonal temperatures can exceed the melting temperature of water; sand-wedge polygons occur in the inland mixed zone. The ADV are characterized by a regional permafrost layer and a shallow ice table. In contrast to more temperate latitudes on Earth where the hydrological system and cycle are vertically integrated, the ADV hydrological system consists of a horizontally stratified hydrological cycle; the regional permafrost layer precludes vertical exchange of surface water and deep groundwater below the permafrost. Local near-surface meltwater is produced seasonally, flows across the surface to create gullies, channels and small fluvial features, and soaks into the dry upper part of the permafrost, running downslope along the top of the ice table in a perched aquifer. In this context, melting of seasonal and perennial surface and very near surface snow and ice deposits during peak seasonal and peak daytime temperatures causes a range of fluvial and liquid water-related features in the coastal thaw zone and inland mixed zone. Among the features and processes that we have analyzed and instrumented over numerous field seasons in the ADV are rock-weathering processes, debris-covered glaciers, viscous flow features, polygons, active gullies, recurring slope lineae, fluvial channels, and small ponds and lakes. Key to understanding these features in the ADV has proven to be: 1) location of surface microenvironments that sequester seasonal and perennial snow and ice, 2) understanding the importance of peak daytime and seasonal temperatures, in contrast to MAT, 3) the role of the shallow ice table in producing a perched aquifer in the dry part of the soil layer above the top of the ice table, 4) understanding the importance of short-term peak melting events (revealed by time-lapse images and environmental instrumentation), 5) measuring seasonal rates of vertical propagation and depths of penetration of the melting geotherm, 6) determining the role of salt exchange in hyporheic zone processes and alteration of rocks and soils, and water chemistry, and 7) analysis of the role of insolation and slope orientation in melting processes. These factors also have important implications for the study and interpretation of water-related features and the climate history of Mars. Similarities are observed between the ADV microenvironments and latitudinal zones and geomorphic feature distributions on Mars.

Head, J.; Dickson, J. L.; Levy, J. S.; Baker, D. M. H.; Marchant, D. R.

2012-04-01

226

Geodynamics applications of continuum physics to geological problems  

SciTech Connect

This textbook deals with the fundamental physical processes necessary for an understanding of plate tectonics and a variety of geologic phenomena. The first chapter reviews plate tectonics; its main purpose is to provide physics, chemistry, and engineering students with the geologic background necessary to understand the applications throughout the rest of the book. It goes on to discuss in following chapters: stress and strain relationships in the earths crust; basic principles of linear elasticity and the lithosphere; heat conduction in the earths crust; principles of gravity measurements; problems involving mantle convection and post glacial rebound; rock mechanics and rheology; principles of fluid flow in porous media; and, fault displacement measurements.

Turcotte, D.L.; Schubert, G.

1982-01-01

227

Structural Geology  

NSDL National Science Digital Library

Created by the University of Nebraska-Lincoln, this site describes the basics of structural geology with text and images. The page includes the discussion of stress, strain, strike and dip, faults, folds, mountain building, erosion, economic geology, and environmental geology. This is a nice introduction to the basic topics in geology. Images from the field help to enhance the topics on the site. Instructors can use this resource to help create or simply enhance their curriculum.

228

Assessment Report, Department of Geology August, 2012  

E-print Network

Assessment Report, Department of Geology August, 2012 1. Learning Goals ALL students in geology, classification schemes, geologic history and processes, and the structure of the Earth. 3. demonstrate an understanding of the variability, complexity, and interdependency of processes within geologic systems. 4. use

Bogaerts, Steven

229

Geological Time  

NSDL National Science Digital Library

"Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.

230

Geological cycles  

Microsoft Academic Search

During the last hundred years, intensive studies have been made on the geological indications of the so called “Ice Ages”;. Already Penck and Bruckner discovered, around the end of the nineteenth century, the cyclic character of these phenomena and distinguished at least four cycles in the Alps area. In fact these geological cycles are controlled by climatic conditions. The geological

B. P. Hageman

1972-01-01

231

Structural Geology  

NSDL National Science Digital Library

This site contains a variety of resources for faculty members who teach undergraduate structural geology. You will find links to activities and assignments, internet and computer resources, useful articles and maps, presentations from the summer 2004 workshop on teaching structural geology, working groups and a discussion forum, and lots of creative ideas for teaching structural geology.

232

GEOLOGY, January 2011 39 INTRODUCTION  

E-print Network

). This geologically based age estimation from Australia agrees with those from south China, where continental rifting Australia Geology, January 2011; v. 39; no. 1; p. 39­42; doi: 10.1130/G31461.1; 2 figures; Data RepositoryGEOLOGY, January 2011 39 INTRODUCTION The breakup processes of the Neoproterozoic supercontinent

233

Influence of fluvial processes on the quaternary geologic framework of the continental shelf, North Carolina, USA  

USGS Publications Warehouse

Digital, single-channel, high-resolution seismic reflection profiles were acquired from the insular continental shelf of North Carolina, USA along a data grid extending from Oregon Inlet northward 48 km to Duck, North Carolina and from the nearshore zone seaward approximately 28 km (total surveyed area= 1334 km2). These data were processed and interpreted to delineate principal reflecting horizons and develop a three-dimensional seismic stratigraphic framework for the continental shelf that was compared to stratigraphic data from the shoreward back-barrier (estuarine) and barrier island system. Six principal reflecting horizons (designated R0 through R5) were present within the upper 60 m of the shelf stratigraphic succession. Three-dimensional mapping of reflector R1 demonstrated its origin from fluvial incision of the continental shelf during an episode (or episodes) of lowered sea-level. Fluvial processes during development of reflector R1 were responsible for extensive reworking and re-deposition of sediment throughout most of the northern half of the study area. Five seismic stratigraphic units (designated S1 through S5) were tentatively correlated with depositional sequences previously identified from the North Carolina back-barrier (estuarine) and barrier island system. These five stratigraphic units span the Quaternary Period (S1 = early Holocene; S2 = 51-78 ka; S3 = 330-530 ka; S4 = 1.1-1.8 Ma; S5 = earliest Pleistocene). Unit S1 is composed of fine-grained fluvial/estuarine sediment that back-filled incised streams during early Holocene sea-level rise. The four other stratigraphic units (S2-S5) display tabular depositional geometries, low total relief, and thicken toward the east-southeast as their basal reflectors dip gently between 0.41 m km-1 (0.02??) and 0.54 m km-1 (0.03??). Knowledge of the three-dimensional subsurface stratigraphic architecture of the continental shelf enhances understanding of the development of shelf depositional successions and provides a framework for development of better Quaternary sea-level data, especially offshore North Carolina where such data are sparse. ?? 2002 Elsevier Science B.V. All rights reserved.

Boss, S.K.; Hoffman, C.W.; Cooper, B.

2002-01-01

234

Geologic nozzles  

USGS Publications Warehouse

The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by the debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. -from Author

Werner, Kieffer S.

1989-01-01

235

Vesta's Geological Features  

NASA Astrophysics Data System (ADS)

Vesta’s diverse geology exhibits impact basins and craters of all sizes and unusual shapes, ejecta blankets, large troughs, impact basins, enigmatic dark material, and considerable evidence for mass wasting and surface alteration processes.

Jaumann, R.; Russell, C. T.; Raymond, C. A.; Pieters, C. M.; Yingst, R. A.; Williams, D. A.; Buczkowski, D. L.; Schenk, P.; De Sanctis, M. C.

2014-02-01

236

A Domain Decomposition Approach for Large-Scale Simulations of Flow Processes in Hydrate-Bearing Geologic Media  

SciTech Connect

Simulation of the system behavior of hydrate-bearing geologic media involves solving fully coupled mass- and heat-balance equations. In this study, we develop a domain decomposition approach for large-scale gas hydrate simulations with coarse-granularity parallel computation. This approach partitions a simulation domain into small subdomains. The full model domain, consisting of discrete subdomains, is still simulated simultaneously by using multiple processes/processors. Each processor is dedicated to following tasks of the partitioned subdomain: updating thermophysical properties, assembling mass- and energy-balance equations, solving linear equation systems, and performing various other local computations. The linearized equation systems are solved in parallel with a parallel linear solver, using an efficient interprocess communication scheme. This new domain decomposition approach has been implemented into the TOUGH+HYDRATE code and has demonstrated excellent speedup and good scalability. In this paper, we will demonstrate applications for the new approach in simulating field-scale models for gas production from gas-hydrate deposits.

Zhang, Keni; Moridis, G.J.; Wu, Y.-S.; Pruess, K.

2008-07-01

237

Missouri University of Science and Technology 1 Geology and Geophysics  

E-print Network

Missouri University of Science and Technology 1 Geology and Geophysics Graduate work in Geology are designed to provide you with an understanding of the fundamentals and principles of geology, geochemistry and Environmental Geochemistry · Mineralogy/Petrology/Economic Geology · Geophysics/Tectonics/Remote Sensing

Missouri-Rolla, University of

238

Ground Penetrating Radar Field Studies of Lunar-Analog Geologic Settings and Processes: Barringer Meteor Crater and Northern Arizona Volcanics  

NASA Astrophysics Data System (ADS)

Ground-Penetrating Radar (GPR) data from terrestrial analog environments can help constrain models for evolution of the lunar surface, aid in interpretation of orbital SAR data, and help predict what might be encountered in the subsurface during future, landed, scientific or engineering operations on the Moon. GPR can yield insight into the physical properties, clast-size distribution, and layering of the subsurface, granting a unique view of the processes affecting an area over geologic time. The purpose of our work is to demonstrate these capabilities at sites at which geologic processes, settings, and/or materials are similar to those that may be encountered on the moon, especially lava flows, impact-crater ejecta, and layered materials with varying properties. We present results from transects obtained at Barringer Meteor Crater, SP Volcano cinder cone, and Sunset Crater Volcano National Monument, all in northern Arizona. Transects were taken at several sites on the ejecta of Meteor Crater, all within a crater radius (~400 m) of the crater rim. Those taken across ejecta lobes or mounds reveal the subsurface contact of the ejecta upper surface and overlying, embaying sediments deposited by later alluvial, colluvial, and/or aeolian processes. Existing mine shafts and pits on the south side of the crater provide cross sections of the subsurface against which we compare adjacent GPR transects. The ‘actual’ number, size, and depth of clasts in the top 1-2 m of the subsurface are estimated from photos of the exposed cross sections. In GPR radargrams, reflections attributed to blocks in the top 2-5 m of the subsurface are counted, and their depth distribution noted. Taking GPR measurements along a transect at two frequencies (200 and 400 MHz) and to various depths, we obtain the ratio of the actual number of blocks in the subsurface to the number detectable with GPR, as well as an assessment of how GPR detections in ejecta decline with depth and depend on antenna frequency. This work allows calibration of GPR-based interpretations of ejecta processes. Work at SP volcano focuses on the northern, lower slopes of the cinder cone, from beneath which a basalt lava flow extends onto surrounding terrain. Layering within cinders is visible in GPR radargrams in the upper ~0.5 m. A small pit reveals that such layering may be due to significant, stratified variation in cinder size, relative moisture content of a fine, loess-like matrix, and fraction of inter-cinder voids, or pore space, filled with matrix. The subsurface cinder-lava contact, as well as some variation within the lava flow (possibly due to varying degrees of coherence and fracturing), is detected by the GPR. Our work will help frame tractable scientific questions in lunar mission development, and aid in interpretation of future returned data. A non-invasive alternative and complement to digging and drilling, GPR is also potentially useful in exploration of other terrestrial bodies.

Russell, P. S.; Grant, J. A.; Williams, K. K.; Bussey, B.

2010-12-01

239

Fundamentals of Physical Geography  

NSDL National Science Digital Library

The Fundamentals of Physical Geography website is designed to be a free online textbook for University and College students studying introductory Physical Geography. Version 1.0 of Fundamentals of Physical Geography contains over three hundred pages of information and more than four hundred 2-D illustrations, photographs, and animated graphics. Besides having the traditional text and 2-D graphics, this information source also has a number of animated graphics, an interactive glossary of terms, a study guide, web pages with links to other Internet resources related to Physical Geography, and a search engine to find information on the Fundamentals of Physical Geography website. The current purpose of this work is to supplement the printed textbooks used in Universities and Colleges with an information source that is interactive and rich in multimedia. The comprehensive table of contents includes chapters on: Introduction to Physical Geography, Maps, Remote Sensing, and GIS, The Science of Physical Geography, Introduction to Systems Theory, The Universe, Earth, Natural Spheres, and GAIA, Energy and Matter, Introduction to Meteorology and Climatology, Introduction to Hydrology, Introduction to Biogeography and Ecology, Introduction to Geology, and Introduction to Geomorphology.

Pidwirny, Michael

240

Marketing fundamentals.  

PubMed

This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined. PMID:11401791

Redmond, W H

2001-01-01

241

Geology Page 145Sonoma State University 2012-2013 Catalog DEPARTMENT OFFICE  

E-print Network

processes, the formation of rocks and minerals, and the energy supplies and materials that support our of geology. Students take a fundamental curriculum that concentrates on the analysis of rocks and minerals 307 Igneous and Metamorphic Petrology 4 GEOL 308 Igneous and Metamorphic Field 1 GEOL 309 Computer

Ravikumar, B.

242

Page 148 Geology Sonoma State University 2011-2012 Catalog Department Office  

E-print Network

to understanding of earth processes, the formation of rocks and minerals, and the energy supplies and materials in the principles of geology. Students take a fundamental curriculum that concentrates on the analysis of rocks and Report Writing 1 GEOL 307 Igneous and Metamorphic Petrology 4 GEOL 308 Igneous and Metamorphic Field 1

Ravikumar, B.

243

Page 204 Geology Sonoma State University 2006-2008 Catalog Department Office  

E-print Network

of geologic time. Practi- cally, it leads to understanding of earth processes, the formation of rocks studies. Students take a fundamental curriculum that concen- trates on the analysis of rocks and minerals Writing 1 GEOL 305 Optical Mineralogy 3 GEOL 307 Igneous and Metamorphic Petrology 4 GEOL 308 Igneous

Ravikumar, B.

244

Terrestrial and Lunar Geological Terminology for Non-Geoscientists  

NASA Technical Reports Server (NTRS)

This slide presentation reviews several geologic concepts applicable to lunar geology with particular interest in creating lunar regolith simulant. Fundamental ways in which the Moon differs from the Earth. Concepts that are described in detail are: minerals, glass, and rocks.

Schrader, Christian M.

2009-01-01

245

Testing the Late Noachian Icy Highlands Model: Geological Observations, Processes and Origin of Fluvial and Lacustrine Features.  

NASA Astrophysics Data System (ADS)

A new reconstruction of the Late Noachian Mars atmosphere and climate shows atmosphere-surface thermal coupling and an adiabatic cooling effect producing preferential distribution of snow and ice in the highlands. In this Late Noachian Icy Highlands (LNIH) scenario, snow and ice accumulate in the south circumpolar region and in the higher altitudes of the southern uplands, but the mean annual temperature is everywhere below freezing. How can the abundant evidence for water-related fluvial and lacustrine activity (valley networks, VN; open-basin lakes, OBL; closed-basin lakes; CBL) be reconciled with the icy highlands model? We investigate the nature of geologic processes operating in the icy highlands and use the Antarctic McMurdo Dry Valleys (MDV) as guidance in understanding and assessing how melting might be taking place. In the MDV, mean annual temperatures (MAT) are well below freezing. This results in a thick regional permafrost layer, the presence of an ice-table at shallow depths, and an overlying dry active layer. This configuration produces a perched aquifer and a horizontally stratified hydrologic system, where any melting results in local saturation of the dry active layer and channelized flow on top of the ice table. Top-down melting results in the dominance of lateral water transport, in contrast to temperate climates with vertical infiltration and transport to the groundwater table. Despite subzero MAT, MDV peak seasonal and peak daytime temperatures can exceed 273K and have a strong influence on the melting of available water ice. We present maps of the predicted distribution of LNIH snow and ice, compare these to the distribution of VN, OBL and CBL, and assess how top-down and bottom-up melting processes might explain the formation of these features in an otherwise cold and icy LN Mars. We assess the global near-surface water budget, analyze thickness estimates to distinguish areas of cold-based and wet-based glaciation, analyze the state of the ice cover and its susceptibility to melting and runoff, and describe top-down melting and fluvial channel formation processes in a LNIH environment. We find that: 1) episodic top-down melting of the LNIH is a robust mechanism to produce the observed fluvial and lacustrine features; 2) the characteristics and distribution of features in the Dorsa Argentea Formation are consistent with an extensive circum-polar ice cap during LNIH time; and 3) the nature of preserved LN impact craters is consistent with impact cratering processes in the LNIH environment. 393 words.

Head, James; Wordsworth, Robin; Forget, Francis; Madeleine, Jean-Baptiste; Halvey, Italy

2014-05-01

246

Reactive Transport Modelling of CO2 Storage in Saline Aquifers to Elucidate Fundamental Processes, Trapping Mechanisms, and Sequestration Partitioning  

Microsoft Academic Search

The ultimate fate of CO injected into saline aquifers for environmental isolation is governed by three interdependent yet conceptually distinct processes: CO migration as a buoyant immiscible fluid phase, direct chemical interaction of this rising plume with ambient saline waters, and its indirect chemical interaction with aquifer and cap-rock minerals through the aqueous wetting phase. Each process is directly linked

J. W. Johnson; J. J. Nitao; K. G. Knauss

2004-01-01

247

Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors  

SciTech Connect

The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

Phillpot, Simon; Tulenko, James

2011-09-08

248

How fundamental are fundamental constants?  

E-print Network

I argue that the laws of physics should be independent of one's choice of units or measuring apparatus. This is the case if they are framed in terms of dimensionless numbers such as the fine structure constant, alpha. For example, the Standard Model of particle physics has 19 such dimensionless parameters whose values all observers can agree on, irrespective of what clock, rulers, scales... they use to measure them. Dimensional constants, on the other hand, such as h, c, G, e, k..., are merely human constructs whose number and values differ from one choice of units to the next. In this sense only dimensionless constants are "fundamental". Similarly, the possible time variation of dimensionless fundamental "constants" of nature is operationally well-defined and a legitimate subject of physical enquiry. By contrast, the time variation of dimensional constants such as c or G on which a good many (in my opinion, confusing) papers have been written, is a unit-dependent phenomenon on which different observers might disagree depending on their apparatus. All these confusions disappear if one asks only unit-independent questions. We provide a selection of opposing opinions in the literature and respond accordingly.

M. J. Duff

2014-12-17

249

Utah Geology  

NSDL National Science Digital Library

Utah Geological Survey's Web site, Utah Geology, offers a variety of interesting geological information about the state. Good descriptions, illustrations, and photographs can be accessed on earthquakes and hazards, dinosaurs and fossils, rocks and minerals, oil and energy, and more. For example, the Rocks and Minerals page contains everything from how to stake a mining claim to downloadable summaries of mineral activity in the state. There is quite a bit of information within the site, and anyone interested in geology will find themselves exploring these pages for quite a while.

250

Geology Field Trips as Performance Evaluations  

ERIC Educational Resources Information Center

One of the most important goals the author has for students in his introductory-level physical geology course is to give them the conceptual skills for solving geologic problems on their own. He wants students to leave his course as individuals who can use their knowledge of geologic processes and logic to figure out the extended geologic history…

Bentley, Callan

2009-01-01

251

California Geological Survey: Geologic Maps  

NSDL National Science Digital Library

This index provides access to a selection of geologic maps of California, as well as an overview of geologic and other mapping activities in the state. The index, which can be accessed by clicking on an interactive map of the state, contains lists of selected geologic maps in California prepared by the Regional Geologic Mapping Project (RGMP). The RGMP staff monitors the literature and collects references that contain geologic mapping that may be useful for future compilations. In addition, the site has information about Caltrans Highway Corridor Mapping, The Mineral Resources and Mineral Hazards Mapping Program, North Coast Watersheds Assessment Program, The Timber Harvesting Plan Enforcement Program, and The Seismic Hazards Mapping Program. A set of links is provided to other sources of geologic maps and map information.

252

Advances in Planetary Geology  

NASA Technical Reports Server (NTRS)

The surface of Mars displays a broad range of channel and valley features. There is as great a range in morphology as in scale. Some of the features of Martian geography are examined. Geomorphic mapping, crater counts on selected surfaces, and a detailed study of drainage basins are used to trace the geologic evolution of the Margaritifer Sinus Quandrangle. The layered deposits in the Valles Marineris are described in detail and the geologic processes that could have led to their formation are analyzed.

Grant, John A., III; Nedell, Susan S.

1987-01-01

253

Geologic analyses of LANDSAT-1 multispectral imagery of a possible power plant site employing digital and analog image processing. [in Pennsylvania  

NASA Technical Reports Server (NTRS)

A site in the Great Valley subsection of the Valley and Ridge physiographic province in eastern Pennsylvania was studied to evaluate the use of digital and analog image processing for geologic investigations. Ground truth at the site was obtained by a field mapping program, a subsurface exploration investigation and a review of available published and unpublished literature. Remote sensing data were analyzed using standard manual techniques. LANDSAT-1 imagery was analyzed using digital image processing employing the multispectral Image 100 system and using analog color processing employing the VP-8 image analyzer. This study deals primarily with linears identified employing image processing and correlation of these linears with known structural features and with linears identified manual interpretation; and the identification of rock outcrops in areas of extensive vegetative cover employing image processing. The results of this study indicate that image processing can be a cost-effective tool for evaluating geologic and linear features for regional studies encompassing large areas such as for power plant siting. Digital image processing can be an effective tool for identifying rock outcrops in areas of heavy vegetative cover.

Lovegreen, J. R.; Prosser, W. J.; Millet, R. A.

1975-01-01

254

Some Fundamental Experiments on Apparent Dissolution Rate of Gas Phase in the Groundwater Recovery Processes of the Geological Disposal System - 12146  

SciTech Connect

The apparent dissolution rates of gas phase in the co-presence of solid phase were examined by in-room experiments in this study. The apparent dissolution rate of gas phase q (mol/m{sup 3}.s) was generally defined by q=aK{sub L}(?P{sub g}-c), where a (1/m) is specific surface area of the interface between gas and liquid phases, K{sub L} (m/s) is overall mass transfer coefficient, ? (mol/(Pa.m{sup 3})) is reciprocal number of Henry constant, P{sub g} (Pa) is partial pressure of gas phase, and c (mol/m{sup 3}) is the concentration of gas component in liquid phase. As a model gas, CO{sub 2} gas was used. For evaluating the values of K{sub L}, this study monitored pH or the migration rate of the interface between water/gas phases, using some experiments such as the packed beds and the micro channel consisting of granite chip and rubber sheet including a slit. In the results, the values of K{sub L} were distributed in the range from 5.0x10{sup -6} m/s to 5.0x10{sup -7} m/s. These values were small, in comparison with that (7.8x10{sup -4} m/s) obtained from the bubbling test where gas phase was continually injected into deionized water without solid phase. This means that the solid phase limits the local mixing of water phase near gas-liquid interfaces. (authors)

Yoshii, Taiki; Niibori, Yuichi; Mimura, Hitoshi [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki, Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan)

2012-07-01

255

North Cascades Geology: Geologic Time  

NSDL National Science Digital Library

This article describes the period of geologic time spanned by the rocks of the North Cascades area of Washington. Users can access a simplified geologic time scale that provides links to geologic events in the North Cascades region. These include the deposition of various terranes, periods of intrusion and metamorphism, the beginning of the Cascade volcanic arc, and periods of major glaciation. Links to related materials are also provided.

256

Healthcare fundamentals.  

PubMed

In order for a trauma surgeon to have an intelligent discussion with hospital administrators, healthcare plans, policymakers, or any other physicians, a basic understanding of the fundamentals of healthcare is paramount. It is truly shocking how many surgeons are unable to describe the difference between Medicare and Medicaid or describe how hospitals and physicians get paid. These topics may seem burdensome but they are vital to all business decision making in the healthcare field. The following chapter provides further insight about what we call "the basics" of providing medical care today. Most of the topics presented can be applied to all specialties of medicine. It is broken down into 5 sections. The first section is a brief overview of government programs, their influence on care delivery and reimbursement, and past and future legislation. Section 2 focuses on the compliance, care provision, and privacy statutes that regulate physicians who care for Medicare/Medicaid patient populations. With a better understanding of these obligations, section 3 discusses avenues by which physicians can stay informed of current and pending health policy and provides ways that they can become involved in shaping future legislation. The fourth section changes gears slightly by explaining how the concepts of trade restraint, libel, antitrust legislation, and indemnity relate to physician practice. The fifth, and final, section ties all of components together by describing how physician-hospital alignment can be mutually beneficial in providing patient care under current healthcare policy legislation. PMID:24918828

Kauk, Justin; Hill, Austin D; Althausen, Peter L

2014-07-01

257

RSNA 2003 LIDC Educational Exhibit: Fundamental Issues for the Creation of a Resource for the Image Processing Research Community  

Cancer.gov

The LIDCThis consortium - called the Lung Image Database Consortium (LIDC) - seeks to establish standard formats and processes by which to manage lung images and the related technical and clinical data that will be used by researchers to develop, train and evaluate CAD algorithms for lung cancer detection and diagnosis.

258

Integration of geological remote-sensing techniques in subsurface analysis  

USGS Publications Warehouse

Geological remote sensing is defined as the study of the Earth utilizing electromagnetic radiation which is either reflected or emitted from its surface in wavelengths ranging from 0.3 micrometre to 3 metres. The natural surface of the Earth is composed of a diversified combination of surface cover types, and geologists must understand the characteristics of surface cover types to successfully evaluate remotely-sensed data. In some areas landscape surface cover changes throughout the year, and analysis of imagery acquired at different times of year can yield additional geological information. Integration of different scales of analysis allows landscape features to be effectively interpreted. Interpretation of the static elements displayed on imagery is referred to as an image interpretation. Image interpretation is dependent upon: (1) the geologist's understanding of the fundamental aspects of image formation, and (2.) his ability to detect, delineate, and classify image radiometric data; recognize radiometric patterns; and identify landscape surface characteristics as expressed on imagery. A geologic interpretation integrates surface characteristics of the landscape with subsurface geologic relationships. Development of a geologic interpretation from imagery is dependent upon: (1) the geologist's ability to interpret geomorphic processes from their static surface expression as landscape characteristics on imagery, (2) his ability to conceptualize the dynamic processes responsible for the evolution 6f interpreted geologic relationships (his ability to develop geologic models). The integration of geologic remote-sensing techniques in subsurface analysis is illustrated by development of an exploration model for ground water in the Tucson area of Arizona, and by the development of an exploration model for mineralization in southwest Idaho.

Taranik, James V.; Trautwein, Charles M.

1976-01-01

259

Yellowstone Geology  

NSDL National Science Digital Library

This Yellowstone National Park website provides geological information about the Park. Links include geologic highlights, hydrothermal features, reports by park geologists, and scientists' talks (videos). A wide array of information can be found on these links and the webpage is expanding as more topics are added.

Yellowstone National Park

260

Yosemite Geology  

NSDL National Science Digital Library

The National Park Service maintains the Yosemite National Park Web site and the corresponding Geology page. This Web site gives an overview of the geologic history of the site, tells how the Sierra Nevada range formed, explains the basics of granitic rock, shows how glaciers carved out the canyons, and much more.[JAB

261

Engineering Geology  

ERIC Educational Resources Information Center

Engineering geology remains a potpourri of applied classical geology, and 1977 witnessed an upswing in demand for these services. Traditional foundation-related work was slight, but construction related to national needs increased briskly. Major cities turned to concerns of transit waste-water treatment and solid-waste disposal. (Author/MA)

Hatheway, Allen W.

1978-01-01

262

Geology Major www.geology.pitt.edu/undergraduate/geology.html  

E-print Network

Geology Major www.geology.pitt.edu/undergraduate/geology.html Revised: 03/2013 Geology is a scientific discipline that aims to understand every aspect of modern and ancient Earth. A degree in geology the field of geology, environmental and geotechnical jobs exist for people with BS degrees. A master

Jiang, Huiqiang

263

The spatial distribution of heavy metals across the Arctic is related to local geology, natural processes, and anthro-  

E-print Network

The spatial distribution of heavy metals across the Arctic is related to local geology, natural, and the characteristics of the receptor compartments. The spatial distribution of heavy metals leading to biotic exposure concentration is a key step toward linking the sources of anthropogenic release of heavy metals, distribution

Ford, Jesse

264

Epithelial-mesenchymal transition as a fundamental underlying pathogenic process in COPD airways: fibrosis, remodeling and cancer.  

PubMed

Chronic obstructive pulmonary disease (COPD) is a complex condition, frequently with a mix of airway and lung parenchymal damage. However, the earliest changes are in the small airways, where most of the airflow limitation occurs. The pathology of small airway damage seems to be wall fibrosis and obliteration, but the whole airway is involved in a 'field effect'. Our novel observations on active epithelial-mesenchymal transition (EMT) in the airways of smokers, particularly in those with COPD, are changing the understanding of this airway pathology and the aetiology of COPD. EMT involves a cascade of regulatory changes that destabilise the epithelium with a motile and mesenchymal epithelial cell phenotype emerging. One important manifestation of EMT activity involves up-regulation of specific key transcription factors (TFs), such as Smads, Twist, and ?-catenin. Such TFs can be used as EMT biomarkers, in recognisable patterns reflecting the potential major drivers of the process; for example, TGF?, Wnt, and integrin-linked kinase systems. Thus, understanding the relative changes in TF activity during EMT may provide rich information on the mechanisms driving this whole process, and how they may change over time and with therapy. We have sought to review the current literature on EMT and the relative expression of specific TF activity, to define the networks likely to be involved in a similar process in the airways of patients with smoking-related COPD. PMID:25113142

Nowrin, Kaosia; Sohal, Sukhwinder Singh; Peterson, Gregory; Patel, Rahul; Walters, Eugene Haydn

2014-10-01

265

Measurement fundamentals  

SciTech Connect

The need to have accurate petroleum measurement is obvious. Petroleum measurement is the basis of commerce between oil producers, royalty owners, oil transporters, refiners, marketers, the Department of Revenue, and the motoring public. Furthermore, petroleum measurements are often used to detect operational problems or unwanted releases in pipelines, tanks, marine vessels, underground storage tanks, etc. Therefore, consistent, accurate petroleum measurement is an essential part of any operation. While there are several methods and different types of equipment used to perform petroleum measurement, the basic process stays the same. The basic measurement process is the act of comparing an unknown quantity, to a known quantity, in order to establish its magnitude. The process can be seen in a variety of forms; such as measuring for a first-down in a football game, weighing meat and produce at the grocery, or the use of an automobile odometer.

Webb, R.A. [Marathon Pipe Line Co., Findlay, OH (United States)

1995-12-01

266

Geological Society of America Special Paper 369  

E-print Network

mechanisms for widespread barite accumulation. This model immediately highlights a fundamental problem conventional sources, hydrothermal waters and rivers, seems untenable. Assuming that available Ba records of Globally Warm Climates in the Early Paleogene: Boulder, Colorado, Geological Society of America Special

Royer, Dana

267

Induced Pluripotent Stem Cells: Fundamentals and Applications of the Reprogramming Process and its Ramifications on Regenerative Medicine  

Microsoft Academic Search

Objective  To provide a comprehensive source of information about the reprogramming process and induced pluripotency.\\u000a \\u000a \\u000a \\u000a Background  The ability of stem cells to renew their own population and to differentiate into specialized cell types has always attracted\\u000a researchers looking to exploit this potential for cellular replacement therapies, pharmaceutical testing and studying developmental\\u000a pathways. While adult stem cell therapy has already been brought to

Bhavita Walia; Neeraj Satija; Rajendra Prashad Tripathi; Gurudutta U. Gangenahalli

268

Digital Geology of Idaho  

NSDL National Science Digital Library

If you have ever wanted to learn about the geology of Idaho, this site is a great way to explore everything from Coeur d'Alene to the Sawtooth Mountains. This digital version of a course offered at Idaho State University systematically divides Idaho geology into a set of different teaching modules. The modules cover topics like the Idaho Batholith, the Columbia River Basalts, and the Lake Bonneville Flood. Each module contains maps, charts, diagrams, and photographs that illuminate the various geological processes that have formed, and continue to form, in each region of the state. Many of the modules also have fly-throughs that superimpose color-coded geology on 3-D topographic maps to provide a graphic visualization Idaho's rivers. Additionally, the site contains slide shows and a set of teaching exercises.

2012-02-17

269

Geologic History  

NSDL National Science Digital Library

This unit introduces younger students to the concept of relative versus absolute time and how geologists determine the age of geologic events and features. Topics include the laws that determine relative age (superposition, cross-cutting relationships, included fragments, and others), and how to re-construct the geologic history of an area using these relationships. There is also information on geologic correlation and the use of index fossils to determine relative age. The section on absolute time discusses some ways of measurement (tree rings, radioactive dating) and introduces the concepts of natural selection and mass extinctions. A vocabulary and downloadable, printable student worksheets are provided.

Medina, Philip

270

Geologic Time  

NSDL National Science Digital Library

The Earth is very old -- 4.5 billion years or more -- according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.

William L. Newman

1997-01-01

271

Femtosecond dynamics of fundamental reaction processes in liquids: Proton transfer, geminate recombination, isomerization and vibrational relaxation. [Spiropyrans  

SciTech Connect

The fast excited state intramolecular proton transfer of 3-hydroxyflavone is measured and effects of external hydrogen-bonding interactions on the proton transfer are studied. The proton transfer takes place in [approximately]240 fsec in nonpolar environments, but becomes faster than instrumental resolution of 110 fsec in methanol solution. The dynamics following photodissociation of CH[sub 2]I[sub 2] and other small molecules provide the first direct observations of geminate recombination. The recombination of many different photodissociating species occurs on a [approximately]350 fsec time scale. Results show that recombination yields but not rates depend on the solvent environment and suggest that recombination kinetics are dominated by a single collision with surrounding solvent cage. Studies of sterically locked phenyl-substituted butadienes offer new insights into the electronic structure and isomerization behavior of conjugated polyenes. Data show no simple correlation between hinderance of specific large amplitude motions and signatures of isomerizative behavior such as viscosity dependent excited state lifetimes, implying that the isomerization does not provide a suitable for simple condensed phase reaction rate theories. The spectral dynamics of a photochromic spiropyran indicate that recombination, isomerization and vibrational relaxation all play important roles in photoreactivity of complex molecules. The interplay of these microscopic phenomena and their effect on macroscopic properties such as photochromism are discussed. All the results indicate that the initial steps of the photochromic reaction process occur extremely rapidly. Laser system and computer codes for data analysis are discussed.

Schwartz, B.J.

1992-11-01

272

The Fundamental Physical Processes Producing and Controlling Stellar Coronal/Transition Region/Chromospheric Activity and Structure  

NASA Technical Reports Server (NTRS)

Our LTSA (Long Term Space Astrophysics) research has utilized current NASA and ESA spacecraft, supporting ground-based IR, radio, and sub-mm telescopes, and the extensive archives of HST (Hubble Space Telescope), IUE (International Ultraviolet Explorer), ROSAT, EUVE (Extreme Ultraviolet Explorer), and other missions. Our research effort has included observational work (with a nonnegligible groundbased component), specialized processing techniques for imaging and spectral data, and semiempirical modelling, ranging from optically thin emission measure studies to simulations of optically thick resonance lines. In our previous LTSA efforts, we have had a number of major successes, including most recently: organizing and carrying out an extensive cool star UV survey in HST cycle eight; obtaining observing time with new instruments, such as Chandra and XMM (X-ray Multi-Mirror) in their first cycles; collaborating with the Chandra GTO program and participating with the Chandra Emission Line Project on multi-wavelength observations of HR 1099 and Capella. These are the main broad-brush themes of our previous investigation: a) Where do Coronae Occur in the Hertzsprung-Russell Diagram? b) Winds of Coronal and Noncoronal Stars; c) Activity, Age, Rotation Relations; d) Atmospheric Inhomogeneities; e) Heating Mechanisms, Subcoronal Flows, and Flares; f) Development of Analysis and Modelling Tools.

Ayres, T. R.; Brown, A.

2000-01-01

273

Exploring the fundamentals of radical assisted NO{sub x} reduction processes of coal combustors. Final report  

SciTech Connect

This report describes experimental studies performed at Carnegie Mellon University to study the parameters that affect the performance of plasma-assisted ammonia radical injection for NO{sub x} control from stationary combustion sources. First, the NO{sub x} reduction potential of hot ammonia injection was studied to determine whether the use of the plasma for radical generation was key to the high NO{sub x} reduction potential of the plasma deNO{sub x} process. It was found that while some of the NO{sub x} reduction in the plasma deNO{sub x} demonstration experiments could be attributed to the enhanced thermal breakdown of NH{sub 3} into NO{sub x} reducing radicals, the effect of using the plasma accounted for 15--35% absolute additional NO{sub x} reduction beyond any thermal benefit. This benefit of using the plasma increases with increased excess air and decreased flue gas temperature. With the benefit of using the plasma verified on the larger scale of a demonstration experiment, two additional experiments were performed to study the parameters that affect plasma deNO{sub x} performance on the local level. The opposed flow experiment failed to produce significant NO{sub x} reduction, although it did highlight some key aspects of plasma performance with ammonia injection. The reverse injection experiment successfully demonstrated the effects of NO-stream temperature, plasma power, and ammonia flow rate on plasma deNO{sub x} performance. Finally, a preliminary study of the chemical kinetics of the plasma deNO{sub x} system was performed. This study highlighted the importance of effective plasma temperature and the residence time of the reagent at that temperature to efficient radical generation.

Chess, K.; Yao, S.C.; Russell, A.G.

1996-05-31

274

Geologic Timeline  

NSDL National Science Digital Library

Dive into the depths of time with this Geologic Timeline. The farther you scroll down, the farther back in time you'll travel. Also, the longer a period is on this page, the longer it lasted in history!

2000-01-01

275

The influence of random slowdown process and lock-step effect on the fundamental diagram of the nonlinear pedestrian dynamics: An estimating-correction cellular automaton  

NASA Astrophysics Data System (ADS)

Random slowdown process and lock-step effect, observed from real-life observation and the experiments of other researchers, were investigated in the view of the pedestrian microscopic behaviors. Due to the limited controllability, repeatability and randomness of the pedestrian experiments, a new estimating-correction cellular automaton was established to research the influence of random slowdown process and lock-step effect on the fundamental diagram. The first step of the model is to estimate the next time-step status of the neighbor cell in front of the tracked pedestrian. The second step is to correct the status and confirm the position of the tracked pedestrian in the next time-step. It is found that the random slowdown process and lock-step have significant influence on the curve configuration and the characteristic parameters, including the concavity-convexity, the inflection point, the maximum flow rate and the critical density etc. The random slowdown process reduces the utilization of the available space between two adjacent pedestrians in the longitudinal direction, especially in the region of intermediate density. However, the lock-step effect enhances the utilization of the available space, especially in the region of high density.

Fu, Zhijian; Zhou, Xiaodong; Chen, Yanqiu; Gong, Junhui; Peng, Fei; Yan, Zidan; Zhang, Taolin; Yang, Lizhong

2015-03-01

276

GEOLOGICAL SCIENCES 694 Tectonic Geomorphology  

E-print Network

GEOLOGICAL SCIENCES 694 Tectonic Geomorphology Winter Quarter 2007 Lecture: TR 10-11:18, Orton 251: schoenbohm.1@osu.edu Required Textbooks Tectonic Geomorphology, Burbank and Anderson, 2001. ISBN: 0-632-04386-5 Course Objectives: To introduce students to fundamental problems in tectonic geomorphology in convergent

Schoenbohm, Lindsay

277

Water in a Crowd In many situations, form biology to geology, water occurs not as the pure bulk  

E-print Network

Water in a Crowd In many situations, form biology to geology, water occurs not as the pure bulk species, and interacting with large organic molecules. In such situations, water does not behave in the same manner as it does in the pure bulk liquid. Water dynamics are fundamental to many processes

Fayer, Michael D.

278

Hospital fundamentals.  

PubMed

Under the current system, orthopaedic trauma surgeons must work in some form of hospital setting as our primary service involves treatment of the trauma patient. We must not forget that just as a trauma center cannot exist without our services, we cannot function without their support. As a result, a clear understanding of the balance between physicians and hospitals is paramount. Historical perspective enables physicians and hospital personnel alike to understand the evolution of hospital-physician relationship. This process should be understood upon completion of this chapter. The relationship between physicians and hospitals is becoming increasingly complex and multiple forms of integration exist such as joint ventures, gain sharing, and co-management agreements. For the surgeon to negotiate well, an understanding of hospital governance and the role of the orthopaedic traumatologist is vital to success. An understanding of the value provided by the traumatologist includes all aspects of care including efficiency, availability, cost effectiveness, and research activities. To create effective and sustainable healthcare institutions, physicians and hospitals must be aligned over a sustained period of time. Unfortunately, external forces have eroded the historical basis for the working relationship between physicians and hospitals. Increased competition and reimbursement cuts, coupled with the increasing demands for quality, efficiency, and coordination and the payment changes outlined in healthcare reform, have left many organizations wondering how to best rebuild the relationship. The principal goal for the physician when partnering with a hospital or healthcare entity is to establish a sustainable model of service line management that protects or advances the physician's ability to make impactful improvements in quality of patient care, decreases in healthcare costs, and improvements in process efficiency through evidence-based practices and protocols. PMID:24918827

Althausen, Peter L; Hill, Austin D; Mead, Lisa

2014-07-01

279

Reports of planetary geology program, 1983  

NASA Technical Reports Server (NTRS)

Several areas of the Planetary Geology Program were addressed including outer solar system satellites, asteroids, comets, Venus, cratering processes and landform development, volcanic processes, aeolian processes, fluvial processes, periglacial and permafrost processes, geomorphology, remote sensing, tectonics and stratigraphy, and mapping.

Holt, H. E. (compiler)

1984-01-01

280

Pennsylvania Geology  

NSDL National Science Digital Library

Three decades after it was published, the Second Geological Survey of Pennsylvania was described as "the most remarkable series of reports ever issued by any survey." Considering the diversity of other geological reports, this was no small compliment. Drawing on support from the Marion and Kenneth Pollock Libraries Program Fund, the Pennsylvania State University Libraries' Digital Preservation Unit was able to digitize not only this fabled Survey, but also the Third and Fourth Surveys as well. Visitors can use the search engine on the homepage to look for items of interest, or they can just browse through the collection at their leisure. The surveys include various maps and illustrations that track mineral deposits and the disposition and location of other natural resources. Additionally, users can look through a miscellaneous set of publications from the early 20th century related to survey work performed by the U.S. Geological Survey.

281

Teaching Geology  

NSDL National Science Digital Library

This rather remarkable website contains a great collection of resources for web-based instruction and demonstrations of geology concepts. The collection includes, under Classroom demonstration, the very useful SeisMac 3.0, which is an application for Mac OS X that turns a laptop computer into a " low-resolution strong-motion accelerometer," or a basic seismograph. It works by accessing the computer's Sudden Motion Sensor in order to display real-time, three axis accelerations graphs. Visitors can use the application to watch the seismic waves go up and down just by tapping their feet on the floor nearby. Other resources include Virtual Earth (an "interactive minicourse on thermal convection") and a link to Geology in the news, which collates important news stories with a geological theme.

282

Reports of Planetary Geology Program, 1982  

NASA Technical Reports Server (NTRS)

Work conducted in the Planetary Geology program is summarized. The following categories are presented: outer solar system satellites; asteroids and comets; Venus; cratering processes and landform development; volcanic processes and landforms; aolian processes and landforms; fluvial processes and landform development; periglacial and permafrost processes; structure, tectonics and stratigraphy; remote sensing and regolith studies; geologic mapping, cartography and geodesy.

Holt, H. E. (compiler)

1982-01-01

283

The U.S. Geological Survey Geo Data Portal: A web service architecture and implementation for geo-climate data access and processing  

NASA Astrophysics Data System (ADS)

Environmental modelers from fields of study including climatology, hydrology, geology, and ecology need common, cross-discipline data sources and processing methods to enable working with large remote datasets. Watershed modelers, for example, need downscaled climate model data and land-cover data summaries to predict streamflow for various future climate scenarios. In turn, ecological modelers need the predicted streamflow conditions to understand how habitat of biotic communities might be affected. The U.S. Geological Survey Geo Data Portal project addresses these needs by providing a flexible application built on open-standard Web services that integrates and streamlines data retrieval and analysis. Open Geospatial Consortium Web Processing Services (WPS) were developed to allow interoperable access to data from servers delivering both defacto standard Climate and Forecast (CF) convention datasets and OGC standard Web Coverage Services (WCS). The Geo Data Portal can create commonly needed derivatives of data in numerous formats. As an example use case, a user can upload a shapefile specifying a region of interest (e.g. a watershed), pick a climate simulation, and retrieve a spreadsheet of predicted daily maximum temperature in that region up to 2100. Outcomes of the Geo Data Portal project support the rapid development of user interfaces for accessing and manipulating environmental data. The Geo Data Portal resulting from this project will be demonstrated accessing a range of climate and landscape data.

Kunicki, T.; Blodgett, D. L.; Booth, N. L.; Suftin, I.; Walker, J. I.

2011-12-01

284

Geological flows  

E-print Network

In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.

Yu. N. Bratkov

2008-11-19

285

FUNDAMENTALS OF PLATE TECTONICS Fall Semester 2012-13  

E-print Network

FUNDAMENTALS OF PLATE TECTONICS Fall Semester 2012-13 Geological Sciences G454/G554 Section 32565, paleomagnetism, petrology, and structural geology that led to the development of plate tectonic theory student will prepare a paper on some aspect or applica- tion of plate tectonic theory. The paper should

Polly, David

286

Project Earth Science: Geology  

NSDL National Science Digital Library

Now you can literally explain what it's like "between a rock and a hard place!" Use Project Earth Science: Geology to introduce your students to plate tectonics and teach them what causes volcanoes and earthquakes. Lead explorations of these and other larger-than-the-classroom geological phenomena with the teacher-tested, Standards -based activities. Earth's physical evolution and dynamic processes are carefully explained in language accessible to students and teachers. Supplemental readings provide educators with the background information to answer student questions and concerns.

Brent A. Ford

2001-01-01

287

Geologic Time  

NSDL National Science Digital Library

This site contains 24 questions on the topic of geologic time, which covers dating techniques and unconformities. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.

Timothy Heaton

288

Antarctica Geology  

NSDL National Science Digital Library

This site contains information about the continent of Antarctica. There is a classroom practice and instructional module. The students will be able to describe the general geology of the land under the Antarctic ice and to explain from where the rocks may have come.

289

The Geology of Callisto  

NASA Technical Reports Server (NTRS)

The geology of Callisto is not boring. Although cratered terrain dominates Callisto (a key end-member of the Jovian satellite system), a number of more interesting features are apparent. Cratered terrain is broken into irregular map-able bright and dark subunits that vary in albedo by a factor of 2, and several relatively smooth units are depleted of small craters. Some of these areas may have been volcanically resurfaced. Lineaments, including parallel and radial sets, may be evidence for early global tectonism. Frost deposition occurs in cold traps, and impact scars have formed from tidally disrupted comets. Geologic evidence suggests that Callisto does have a chemically differentiated crust. Central pit and central dome craters and palimpsests are common. The preferred interpretation is that a relatively ice-rich material, at depths of 5 km or more, has been mobilized during impact and exposed as domes or palimpsests. The close similarity in crater morphologies and dimensions indicates that the outermost 10 km or so of Callisto may be as differentiated as on Ganymede. The geology of cratered terrain on Callisto is simpler than that of cratered terrain on Ganymede, however. Orbital evolution and tidal heating may provide the answer to the riddle of why Callisto and Ganymede are so different (Malhotra, 1991). We should expect a few surprises and begins to answer some fundamental questions when Callisto is observed by Galileo in late 1996.

Schenk, Paul M.

1995-01-01

290

Sedimentary RocksSedimentary Rocks Geology 200  

E-print Network

Sedimentary RocksSedimentary Rocks Geology 200 Geology for Environmental ScientistsGeology for Environmental Scientists #12;Major Concepts · Sedimentary rocks form by the processes of weathering, erosion · Sedimentary structures are critical to interpreting sedimentary rocks. #12;The Rock CycleThe Rock Cycle #12

Kammer, Thomas

291

Model Fundamentals - version 2  

NSDL National Science Digital Library

Model Fundamentals, part of the Numerical Weather Prediction Professional Development Series and the "NWP Training Series: Effective Use of NWP in the Forecast Process", describes the components of an NWP model and how they fit into the forecast development process. It also explores why parameterization of many physical processes is necessary in NWP models. The module covers background concepts and terminology necessary for learning from the other modules in this series on NWP. Back in 2000, the subject matter expert for this module was Dr. Ralph Petersen of the National Centers for Environmental Prediction, Environmental Modeling Center (NCEP/EMC). Revisions to the module were made in 2009 by Drs. Bill Bua and Stephen Jascourt, from the NWP team at UCAR/COMET.

COMET

2009-11-05

292

Influence of Introgression and Geological Processes on Phylogenetic Relationships of Western North American Mountain Suckers (Pantosteus, Catostomidae)  

PubMed Central

Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data with morphological and paleontological data for proposed species of Pantosteus, (2) tests hypotheses of their monophyly, (3) uses these data for phylogenetic inferences of sister-group relationships, and (4) estimates timing of divergence events of identified lineages. Using 8055 base pairs from mitochondrial DNA protein coding genes, Pantosteus and Catostomus are reciprocally monophyletic, in contrast with morphological data. The only exception to a monophyletic Pantosteus is P. columbianus whose mtDNA is closely aligned with C. tahoensis because of introgression. Within Pantosteus, several species have deep genetic divergences among allopatric sister lineages, several of which are diagnosed and elevated to species, bringing the total diversity in the group to 11 species. Conflicting molecular and morphological data may be resolved when patterns of divergence are shown to be correlated with sympatry and evidence of introgression. PMID:24619087

Unmack, Peter J.; Dowling, Thomas E.; Laitinen, Nina J.; Secor, Carol L.; Mayden, Richard L.; Shiozawa, Dennis K.; Smith, Gerald R.

2014-01-01

293

Chip-off-the-old-rock: the study of reservoir-relevant geological processes with real-rock micromodels.  

PubMed

We present a real-rock micromodel approach whereby microfluidic channels are fabricated in a naturally occurring mineral substrate. The method is applied to quantify calcite dissolution which is relevant to oil/gas recovery, CO2 sequestration, and wastewater disposal in carbonate formations - ubiquitous worldwide. The key advantage of this method is the inclusion of both the relevant substrate chemistry (not possible with conventional microfluidics) and real-time pore-scale resolution (not possible with core samples). Here, microchannels are etched into a natural calcite crystal and sealed with a glass slide. The approach is applied to study acidified brine flow through a single channel and a two-dimensional micromodel. The single-channel case conforms roughly to a 1-D analytical description, with crystal orientation influencing the local dissolution rate an additional 25%. The two-dimensional experiments show highly flow-directed dissolution and associated positive feedback wherein acid preferentially invades high conductivity flow paths, resulting in higher dissolution rates ('wormholing'). These experiments demonstrate and validate the approach of microfabricating fluid structures within natural minerals for transport and geochemical studies. More broadly, real-rock microfluidics open the door to a vast array of lab-on-a-chip opportunities in geology, reservoir engineering, and earth sciences. PMID:25236399

Song, Wen; de Haas, Thomas W; Fadaei, Hossein; Sinton, David

2014-11-21

294

A Comparison of Multivariate and Pre-Processing Methods for Quantitative Laser-Induced Breakdown Spectroscopy of Geologic Samples  

NASA Technical Reports Server (NTRS)

The ChemCam instrument selected for the Curiosity rover is capable of remote laser-induced breakdown spectroscopy (LIBS).[1] We used a remote LIBS instrument similar to ChemCam to analyze 197 geologic slab samples and 32 pressed-powder geostandards. The slab samples are well-characterized and have been used to validate the calibration of previous instruments on Mars missions, including CRISM [2], OMEGA [3], the MER Pancam [4], Mini-TES [5], and Moessbauer [6] instruments and the Phoenix SSI [7]. The resulting dataset was used to compare multivariate methods for quantitative LIBS and to determine the effect of grain size on calculations. Three multivariate methods - partial least squares (PLS), multilayer perceptron artificial neural networks (MLP ANNs) and cascade correlation (CC) ANNs - were used to generate models and extract the quantitative composition of unknown samples. PLS can be used to predict one element (PLS1) or multiple elements (PLS2) at a time, as can the neural network methods. Although MLP and CC ANNs were successful in some cases, PLS generally produced the most accurate and precise results.

Anderson, R. B.; Morris, R. V.; Clegg, S. M.; Bell, J. F., III; Humphries, S. D.; Wiens, R. C.

2011-01-01

295

Influence of introgression and geological processes on phylogenetic relationships of Western North American mountain suckers (Pantosteus, Catostomidae).  

PubMed

Intense geological activity caused major topographic changes in Western North America over the past 15 million years. Major rivers here are composites of different ancient rivers, resulting in isolation and mixing episodes between river basins over time. This history influenced the diversification of most of the aquatic fauna. The genus Pantosteus is one of several clades centered in this tectonically active region. The eight recognized Pantosteus species are widespread and common across southwestern Canada, western USA and into northern Mexico. They are typically found in medium gradient, middle-elevation reaches of rivers over rocky substrates. This study (1) compares molecular data with morphological and paleontological data for proposed species of Pantosteus, (2) tests hypotheses of their monophyly, (3) uses these data for phylogenetic inferences of sister-group relationships, and (4) estimates timing of divergence events of identified lineages. Using 8055 base pairs from mitochondrial DNA protein coding genes, Pantosteus and Catostomus are reciprocally monophyletic, in contrast with morphological data. The only exception to a monophyletic Pantosteus is P. columbianus whose mtDNA is closely aligned with C. tahoensis because of introgression. Within Pantosteus, several species have deep genetic divergences among allopatric sister lineages, several of which are diagnosed and elevated to species, bringing the total diversity in the group to 11 species. Conflicting molecular and morphological data may be resolved when patterns of divergence are shown to be correlated with sympatry and evidence of introgression. PMID:24619087

Unmack, Peter J; Dowling, Thomas E; Laitinen, Nina J; Secor, Carol L; Mayden, Richard L; Shiozawa, Dennis K; Smith, Gerald R

2014-01-01

296

Geology Fulbrights  

NASA Astrophysics Data System (ADS)

Fulbright grants in geology for 1988-89 remain open. Specific opportunities are available in Egypt, German Democratic Republic, Hungary, Iceland, Iraq, Kuwait, Morocco, Mozambique, Oman, Poland, Sudan, Syria, Tanzania, Turkey, U.S.S.R., West Bank, Yemen, and Zimbabwe. Other countries are also open to applications in any discipline, and geology is among their preferred fields.The grants are available until awarded and are open only to U.S. citizens. In Central and South America and French-speaking Africa, knowledge of host-country language is required. For more information, contact the Council for International Exchange of Scholars (CIES), 11 Dupont Circle N.W., Suite 300, Washington, DC 20036; tel. 202-939-5401.

297

Teaching Geology  

NSDL National Science Digital Library

The study of geology at the University of Colorado has a long and distinguished history, and in recent years they have also become increasingly interested in providing online teaching resources in the field. Educators will be glad to learn about this site's existence, as they can scroll through a list of interactive demonstrations that can be utilized in the classroom. Specifically, these demonstrations include a shaded interactive topographical map of the western United States, a magnetic field of the Earth, and several animated maps of various National Park sites. The site comes to a compelling conclusion with the inclusion of the geology department's slide library, which can be used without a password or registration.

298

Geological assessing of urban environments with a systematic mapping survey: The 1:5000 urban geological map of Catalonia  

NASA Astrophysics Data System (ADS)

The ground features of urban areas and the geologic processes that operate on them are, in general, strongly altered from their natural original condition as a result of anthropogenic activities. Assessing the stability of the ground, the flooding areas, and, the health risk as a consequence of soil pollution, are, among others, fundamental topics of urban areas that require a better understanding. The development of systematic urban geological mapping projects provides valuable resources to address these issues. Since 2007, the Institut Geologic de Catalunya (IGC) runs an urban geological mapping project, to provide accurate geologic information of county capitals and towns of more than 10000 inhabitants of Catalonia. The urban zones of 131 towns will be surveyed for this project, totalizing an area of about 2200 km2 to be mapped in 15 years. According to the 2008 census, the 82 % of the population of Catalonia (7.242.458 inhabitants) lives in the areas to be mapped in this project. The mapping project integrates in a GIS environment the following subjects: - Data from pre-existing geotechnical reports, historical geological and topographical maps and, from historical aerial photographs. - Data from available borehole databases. - Geological characterization of outcrops inside the urban network and neighbouring areas. - Geological, chemical and physical characterisation of representative rocks, sediments and soils. - Ortophotographs (0.5 m pixel size) and digital elevation models (5 meter grid size) made from historical aerial photographs, to depict land use changes, artificial deposits and geomorphological elements that are either hidden or destroyed by urban sprawl. - Detailed geological mapping of quaternary sediments, subsurface bedrock and artificial deposits. - Data from subsurface prospection in areas with insufficient or confuse data. - 3D modelling of the main geological surfaces such as the top of the pre-quaternary basement. All the gathered data is harmonised and stored it in a database. The analysis of the database allows to compile and print the 1:5000 scale urban geological map according to the 1:5000 topographic grid of Catalonia. The map is composed by a principal map, geologic cross sections and several complementary maps, charts and tables. Regardless of the geological map units, the principal map also includes the main artificial deposits (such as infilled river valleys and road embankments), very recent or current superficial deposits, contours of outcropping areas, structural data and other relevant information gathered in stations, sampling points, boreholes indicating the thickness of artificial deposits and the depth of the pre-quaternary basement, contour lines of the top of the pre-quaternary basement surface and, water level data. The complementary maps and charts may change depending on the gathered data, the geological features of the area and the urban typology. However, the most representative complementary maps that includes the printed urban map are the quaternary subsurface bedrock map and the isopach map of thickness of quaternary and anthropogenic deposits. The map also includes charts and tables of relevant physical and chemical parameters of the geological materials, harmonised downhole lithological columns from selected boreholes, and, photographs and figures illustrating the geology of the mapped area and how urbanisation has changed the natural environment. The object of this systematic urban mapping survey is to provide a robust database to be used in targeted studies related to urban planning, geoengineering works, soil pollution and other important environmental issues that society should deal in the future.

Vilà, Miquel; Pi, Roser; Cirés, Jordi; de Paz, Ana; Berástegui, Xavier

2010-05-01

299

Biotic survival in the cryobiosphere on geological scale: implication for astro\\/terrestrial biogeoscience  

Microsoft Academic Search

In current opinion the most fundamental aspect of any environment, the temperature regime, acts as a regulator of all of the physical-chemical reactions and forms the basis of all biological processes. Now hard data indicate the biotic survival over geological periods from subzero temperatures (down to -27oC in permafrost and to -50oC in ice) to positive one in amber and

D. Gilichinsky

2003-01-01

300

Geological hazards programs and research in the U. S. A  

SciTech Connect

Geological hazards have been studied for centuries, but government support of research to lessen their effects is relatively new. This article briefly describes government programs and research underway in the U.S.A. that are directed towards reducing losses of life and property from earthquakes, volcanic eruptions and landslides. The National Earthquake program is described, including four basic research areas: plate tectonics; estimation of the earthquakes; and effects and hazards assessment. The Volcano Studies Program has three areas of research: fundamentals of volcanoes; hazards assessments; and volcano monitoring. Three research areas are included in landslide studies: land slide processes; prediction; inventory and susceptibility studies.

Filson, J.R. (Geological Survey, Reston, VA (USA))

1988-01-01

301

Chapter 2: C Fundamentals C Fundamentals  

E-print Network

rights reserved. 1 Chapter 2: C Fundamentals Program: Printing a Pun #include int main be stored in a file named pun.c. · The file name doesn't matter, but the .c extension isThe file name doesn reserved. 3 Chapter 2: C Fundamentals Compiling and Linking Using cc · To compile and link the pun

Lanubile, Filippo

302

Tour of Park Geology: Shoreline Geology  

NSDL National Science Digital Library

This National Park Service (NPS) site provides links to shoreline geology fieldnotes for National Parks, Monuments, and Recreation Areas. When appropriate, fieldnotes include visitor information, geology, maps, photographs, multimedia resources, geologic research, and teacher features (lessons for teaching geology with National Park examples). Some of the parks included on this site: Acadia National Park, Everglades National Park, and Padre Island National Seashore.

303

Mapping the seafloor geology offshore of Massachusetts  

USGS Publications Warehouse

Geologic and bathymetric maps help us understand the evolutionary history of the Massachusetts coast and the processes that have shaped it. The maps show the distribution of bottom types (for example, bedrock, gravel, sand, mud) and water depths over large areas of the seafloor. In turn, these two fundamental parameters largely determine the species of flora and fauna that inhabit a particular area. Knowledge of bottom types and water depths provides a framework for mapping benthic habitats and managing marine resources. The need for coastal–zone mapping to inform policy and management is widely recognized as critical for mitigating hazards, creating resource inventories, and tracking environmental changes (National Research Council, 2004; U.S. Commission on Ocean Policy, 2004).

Barnhardt, Walter A.; Andrews, Brian D.

2006-01-01

304

The Martian geomorphology as mapped by the Mars Express High Resolution Stereo Camera (HRSC): Implications for Geological Processes and Climate Conditions  

NASA Astrophysics Data System (ADS)

Due to the strong evidence for aqueous processes at or near the surface, Mars is the most Earth-like body in the Solar System. After 10 years of ESA's Mars Express orbiting the planet its High Resolution Stereo Camera (HRSC) covered about 90 % of the surface in stereo and color with resolutions up to 10 m/pixel [1]. Digital elevation models of up to 50 m grid spacing, generated from all suitable datasets of the stereo coverage, currently cover about 40 % of the surface [2]. The geomorphological analysis of surface features, observed by the HRSC indicate major surface modifications by endogenic and exogenic processes on all scales. Endogenic landforms (e.g., tectonic rifts, small basaltic shield volcanoes) were found to be very similar to their equivalents on Earth [1,3,4,5,6,7], suggesting that no unique processes are required to explain their formation. Volcanism may have been active up to the very recent past or even to the present, putting important constraints on thermal evolution models [6,7]. The analysis of diverse landforms produced by aqueous processes revealed that surface water activity was likely episodic, but ranged in age from very ancient to very recent [1,8-16]. Particularly important is prominent glaciation and periglacial features at several latitudes, including mountain glaciers [17-21]. The identification of aqueous alteration minerals and their geological context has enabled a better understanding of paleoenvironmental conditions and pedogenetic processes [23-25]. Dark dunes contain volcanic material and are evidence for the significantly dynamic surface environment, characterized by widespread erosion, transport, and redeposition [26]. Since basically all geologic interpretations of extraterrestrial features require profound knowledge of the Earth as key reference, studies of terrestrial analogues are mandatory in planetary geology. Field work in Antarctica, Svalbard and Iceland [5,6,21,22,27] provided a basis for the analysis of periglacial and volcanic processes, respectively. References: [1]Jaumann et al., 2007, PSS 55; [2]Gwinner et al., 2010, EPSL 294; [3]Neukum et al., 2004, Nature 432; [4]Neukum et al., EPSL 294;[5] Hauber et al., 2005, Nature 434; [6]Hauber et al., 2009 PSS 57; [7]Platz and Michael, 2011, EPSL 312, [8]Jaumann et al., 2005, GRL 32; [9]Jaumann et al., 2010, EPSL 294; [10]Erkeling et al., 2010, EPSL 294; [11]Erkeling et al., 2012, Icarus, 219; [12]Kleinhans et al., 2010, EPSL 294; [13]Reiss et al., 2009, PSS 57; [14]Kneissl et al., 2010, EPSL 294; [15]Di Achille et al., 2006, JGR 111; [16]Di Achille et al., 2006, GRL 33; [17]Head et al., 2005 Nature 434; [18]Murray et al., 2005 Nature 434; [19]Pacifici et al., 2009, Icarus 202; [20]Rossi et al., 2011, Geol. Soc. Am.356; [21]Marchant and Head, 2007, Icarus; [22]Ulrich et al., 2011 Geomorphology 134;[23] Le Deit et al., 2010, Icarus 208; [24]Le Deit et al., 2012, JGR 117; [25]Bishop et al., 2013, JGR 118; [26]Tirsch et al., 2011, JGR 116; [27]Hauber et al., 2011, Geol. Soc. Am. 483.

Jaumann, R.; Neukum, G.; Hauber, E.; Hoffmann, H.; Roatsch, T.; Gwinner, K.; Scholten, F.; Di Achille, G.; Duxbury, T.; Erkeling, G.; van Gasselt, S.; Gupta, S.; Head, J. W.; Hiesinger, H.; Ip, W.; Keller, H.; Kleinhans, M. G.; Kneissl, T.; Le Deit, L.; McCord, T. B.; Muller, J.; Murray, J. J.; Pacifici, A.; Platz, T.; Pinet, P. C.; Reiss, D.; Rossi, A.; Spohn, T.; Tirsch, D.; Williams, D. A.

2013-12-01

305

Fundamental Plasma Processes in Saturn's Magnetosphere B.H. Mauk, D.C. Hamilton, T.W. Hill, G.B. Hospodarsky, R.E. Johnson, C. Paranicas, E. Roussos,  

E-print Network

Chapter 11 Fundamental Plasma Processes in Saturn's Magnetosphere B.H. Mauk, D.C. Hamilton, T that control the extensive space environ- ment, or magnetosphere, of Saturn (see Chapter 9, for the global under- standing of the operations of Saturn's magnetosphere and its relationship to those of Earth

Johnson, Robert E.

306

Fundamentals of the dwarf fundamental plane  

NASA Astrophysics Data System (ADS)

Aims: Star-forming dwarfs are studied to elucidate the physical underpinnings of their fundamental plane. Processes controlling dynamics are evaluated, connections between quiescent and bursting dwarfs are examined, and the viability of using structural properties of dwarfs to determine distances is assessed. Methods: Deep surface photometry in Ks is presented for 19 star-forming dwarfs. The data are amalgamated with previously published observations to create a sample of 66 galaxies suitable for exploring how global properties and kinematics are connected. Results: It is confirmed that residuals in the Tully-Fisher relation are correlated with surface brightness, but that even after accomodating the surface brightness dependence through the dwarf fundamental plane, residuals in absolute magnitude are far larger than expected from observational errors. Rather, a morefundamental plane is identified which connects the potential to HI line width and surface brightness. Residuals correlate with the axis ratio in a way which can be accommodated by recognizing the galaxies to be oblate spheroids viewed at varying angles. Correction of surface brightnesses to face-on leads to a correlation among the potential, line width, and surface brightness for which residuals are entirely attributable to observational uncertainties. The mean mass-to-light ratio of the diffuse component of the galaxies is constrained to be 0.88 ± 0.20 in Ks. Blue compact dwarfs lie in the same plane as dwarf irregulars. The dependence of the potential on line width is less strong than expected for virialized systems, but this may be because surface brightness is acting as a proxy for variations in the mass-to-light ratio from galaxy to galaxy. Altogether, the observations suggest that gas motions are predominantly disordered and isotropic, that they are a consequence of gravity, not turbulence, and that the mass and scale of dark matter haloes scale with the amount and distribution of luminous matter. The tight relationship between the potential and observables offers the promise of determining distances to unresolved star-forming dwarfs to an accuracy comparable to that provided by the Tully-Fisher relation for spirals. Based on observations acquired from CFHT, CTIO, ESO, OAN-SPM, and SAAO.

McCall, M. L.; Vaduvescu, O.; Pozo Nunez, F.; Barr Dominguez, A.; Fingerhut, R.; Unda-Sanzana, E.; Li, B.; Albrecht, M.

2012-04-01

307

Results from an International Simulation Study on Coupled Thermal,Hydrological, and Mechanical (THM) Processes near Geological NuclearWaste Repositories  

SciTech Connect

As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.

Rutqvist, Jonny; Rutqvist, J.; Barr, D.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O.; Liu, Q.-S; Oda, Y.; Wang, W.; Zhang, C.-Y.

2007-10-23

308

Precise determination of ?88Sr in rocks, minerals, and waters by double-spike TIMS: A powerful tool in the study of chemical, geologic, hydrologic and biologic processes  

USGS Publications Warehouse

We present strontium isotopic (88Sr/86Sr and 87Sr/86Sr) results obtained by 87Sr–84Sr double spike thermal ionization mass-spectrometry (DS-TIMS) for several standards as well as natural water samples and mineral samples of abiogenic and biogenic origin. The detailed data reduction algorithm and a user-friendly Sr-specific stand-alone computer program used for the spike calibration and the data reduction are also presented. Accuracy and precision of our ?88Sr measurements, calculated as permil (‰) deviations from the NIST SRM-987 standard, were evaluated by analyzing the NASS-6 seawater standard, which yielded ?88Sr = 0.378 ± 0.009‰. The first DS-TIMS data for the NIST SRM-607 potassium feldspar standard and for several US Geological Survey carbonate, phosphate, and silicate standards (EN-1, MAPS-4, MAPS-5, G-3, BCR-2, and BHVO-2) are also reported. Data obtained during this work for Sr-bearing solids and natural waters show a range of ?88Sr values of about 2.4‰, the widest observed so far in terrestrial materials. This range is easily resolvable analytically because the demonstrated external error (±SD, standard deviation) for measured ?88Sr values is typically ?0.02‰. It is shown that the “true” 87Sr/86Sr value obtained by the DS-TIMS or any other external normalization method combines radiogenic and mass-dependent mass-fractionation effects, which cannot be separated. Therefore, the “true” 87Sr/86Sr and the ?87Sr parameter derived from it are not useful isotope tracers. Data presented in this paper for a wide range of naturally occurring sample types demonstrate the potential of the ?88Sr isotope tracer in combination with the traditional radiogenic 87Sr/86Sr tracer for studying a variety of biological, hydrological, and geological processes.

Neymark, Leonid A.; Premo, Wayne R.; Mel'nikov, Nikolay N.; Emsbo, Poul

2014-01-01

309

Medical Geology in Africa  

Microsoft Academic Search

\\u000a A large body of evidence points to significant health effects resulting from our interactions with the physical environment\\u000a and we continue to recognise connections between geological materials and processes and human and animal disease. In Africa,\\u000a these relationships have been observed for many years, but only recently have any real attempts been made to formalise their\\u000a study. Africa is a

T. C. Davies

310

A Handbook for Geology Students Why study Geology?.............................................................................................3  

E-print Network

1 A Handbook for Geology Students #12;2 Contents Why study Geology ..................................................................................7 Why Appalachian Geology?................................................................................10 Geology Faculty and Staff

Thaxton, Christopher S.

311

Turning Geological Data into Reliable Mineral Resource Estimates1  

Microsoft Academic Search

This paper deals with the building of geological interpretations from necessarily limited geological data and the use of such interpretations in the estimation of mineral resources. Since geological interpretations are a type of scientific model, the process of constructing such models in terms of the objectives and mechanics involved is briefly reviewed. Particular aspects of geological interpretations relevant to resource

John Vann

312

Chemical Engineering Division fuel cycle programs. Quarterly progress report, April-June 1979. [Pyrochemical/dry processing; waste encapsulation in metal; transport in geologic media  

SciTech Connect

For pyrochemical and dry processing materials development included exposure to molten metal and salt of Mo-0.5% Ti-0.07% Ti-0.01% C, Mo-30% W, SiC, Si/sub 2/ON/sub 2/, ZrB/sub 2/-SiC, MgAl/sub 2/O/sub 4/, Al/sub 2/O/sub 3/, AlN, HfB/sub 2/, Y/sub 2/O/sub 3/, BeO, Si/sub 3/N/sub 4/, nickel nitrate-infiltrated W, W-coated Mo, and W-metallized alumina-yttria. Work on Th-U salt transport processing included solubility of Th in liquid Cd, defining the Cd-Th and Cd-Mg-Th phase diagrams, ThO/sub 2/ reduction experiments, and electrolysis of CaO in molten salt. Work on pyrochemical processes and associated hardware for coprocessing U and Pu in spent FBR fuels included a second-generation computer model of the transport process, turntable transport process design, work on the U-Cu-Mg system, and U and Pu distribution coefficients between molten salt and metal. Refractory metal vessels are being service-life tested. The chloride volatility processing of Th-based fuel was evaluated for its proliferation resistance, and a preliminary ternary phase diagram for the Zn-U-Pu system was computed. Material characterization and process analysis were conducted on the Exportable Pyrochemical process (Pyro-Civex process). Literature data on oxidation of fissile metals to oxides were reviewed. Work was done on chemical bases for the reprocessing of actinide oxides in molten salts. Flowsheets are being developed for the processing of fuel in molten tin. Work on encapsulation of solidified radioactive waste in metal matrix included studies of leach rate of crystalline waste materials and of the impact resistance of metal-matrix waste forms. In work on the transport properties of nuclear waste in geologic media, adsorption of Sr on oolitic limestone was studied, as well as the migration of Cs in basalt. Fitting of data on the adsorption of iodate by hematite to a mathematical model was attempted.

Steindler, M.J.; Ader, M.; Barletta, R.E.

1980-09-01

313

Fundamentals of Space Systems  

NASA Astrophysics Data System (ADS)

Fundamentals of Space Systems was developed to satisfy two objectives: the first is to provide a text suitable for use in an advanced undergraduate or beginning graduate course in both space systems engineering and space system design. The second is to be a primer and reference book for space professionals wishing to broaden their capabilities to develop, manage the development, or operate space systems. The authors of the individual chapters are practicing engineers that have had extensive experience in developing sophisticated experimental and operational spacecraft systems in addition to having experience teaching the subject material. The text presents the fundamentals of all the subsystems of a spacecraft missions and includes illustrative examples drawn from actual experience to enhance the learning experience. It included a chapter on each of the relevant major disciplines and subsystems including space systems engineering, space environment, astrodynamics, propulsion and flight mechanics, attitude determination and control, power systems, thermal control, configuration management and structures, communications, command and telemetry, data processing, embedded flight software, survuvability and reliability, integration and test, mission operations, and the initial conceptual design of a typical small spacecraft mission.

Pisacane, Vincent L.

2005-06-01

314

Spirit's Traverse to the Columbia Hills: Systematic Variations in Clast Morphometry and Texture of Pebble to Cobble Sized Clasts, With Implications for Geological Processes and History  

NASA Astrophysics Data System (ADS)

During the course of Spirit's traverse from the Columbia Memorial Station to the Columbia Hills a systematic set of PanCam observations called the clast survey were taken to look for evidence of fluvial activity affecting the morphology of pebble to cobble sized material. These PanCam observations employed a single frame, blue filter shot at 4 bits/pixel looking just above the deck in front of the rover at an angle centering the frame at -72 degrees. These images were taken at 42 sites during the course of the traverse from the landing site to the base of the Columbia Hills. This traverse encountered approximately 6 different geological units that were inferred from orbital data including thermal inertia estimates from Odyssey's THEMIS instrument, as well as geomorphic features observed by the Mars Global Surveyor's Mars Orbital Camera (MOC). Clast survey observations enabled quantification of changes in the size, roundness, sphericity, sorting, density (clasts/meter2), dispersion (nearest neighbor distances) and vesicularity of clasts over the course of Spirit's traverse across the plains to the base of the Columbia Hills. The overall goal was to look for trends in the above parameters that could allow an objective discrimination between basic erosional/depositional processes, including impact, fluvial, debris flow, glacial, and aeolian. To assist the interpretation of this data set, a variety of potential terrestrial analogs were investigated using the same clast survey parameters that were employed during Spirit's traverse. Each terrestrial analog was selected to represent an end member geologic process that could have shaped local clast distribution and morphology. These data sets were analyzed using SAS/STAT statistical software, employing Principle Component Analysis (PCA) to reduce the dimensionality of the data set, focus attention on the relationships between independent variables, and to identify factors that, taken together, could provide an objective basis for discriminating between geological processes. During the course of the traverse, significant changes were observed in clast size when moving from the continuous ejecta blanket of Bonneville crater (high thermal inertia) onto the intercrater plains (low thermal inertia). However, this trend was not apparent when crossing the continuous ejecta of two smaller craters, Lahontan and Missoula. In fact, clast sizes for these two craters compared more closely to the smooth intercrater plains unit previously mapped from orbit. Over the traverse, significant variations were observed in the distribution of vesicular clasts and in clast density. Changes in vesicularity are interpreted as relfecting local changes in the distribution and impact excavation depths of buried lava flow surfaces. Observed trends in clast size correlated well with thermal inertia values, as estimated from orbital (THEMIS) data. Over the course of the traverse, clast roundness and sorting remained remarkably consistent, with mean estimates falling between sub-angular to subrounded, and poorly sorted. These observations do not support previous suggestions of water-based depositional systems (fluvial, debris flow, or glacial processes) at the Spirit landing site, based on orbital data. Instead, observed trends are consistent with a heavily cratered, wind modified ejecta surface, developed above a flow-dominated basaltic volcanic sequence.

Grant, F. D.; Farmer, J. D.; Team, M.

2005-05-01

315

Illinois State Geological Survey  

NSDL National Science Digital Library

The Illinois State Geological Survey (ISGS) homepage provides information on geologic mapping, earthquakes, fossils, groundwater, wetlands, glacial geology, bedrock geology, and Lake Michigan geology. Educational materials include field trip guides, short publications on Illinois geology for students and teachers, online tours, single-page maps, and a geologic column. Other materials include databases and collections of GIS data, well records, drill cores, and mining information; a bibliography of Illinois geology; online maps and data; and information on water and land use, resource development, and geologic hazards.

316

Exchange Rates and Fundamentals.  

ERIC Educational Resources Information Center

We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…

Engel, Charles; West, Kenneth D.

2005-01-01

317

Fundamentals of Laser Safety  

E-print Network

Fundamentals of Laser Safety The University of Florida Business Affairs Division of EH&S #12;Part 1: Fundamentals of Laser Operation #12;Laser Fundamentals The light emitted from a laser is monochromatic (or wavelengths) of light. Lasers emit light that is highly directional, that is, laser light

Wu, Dapeng Oliver

318

PROCEEDINGS: JOINT SYMPOSIUM ON DRY SO2 AND SIMULTANEOUS SO2/NOX CONTROL TECHNOLOGIES (1ST). VOLUME 1. FUNDAMENTAL RESEARCH AND PROCESS DEVELOPMENT  

EPA Science Inventory

Forty six papers describing recent advances in dry sorbent injection technologies for SO2 control were presented at the 1st Joint Symposium on Dry SO2 and Simultaneous SO2/NOx Control Technologies. These papers covered the following topics: fundamental research; pilot-scale devel...

319

Geologic Technician New Curriculum  

ERIC Educational Resources Information Center

Describes a developing two-year geologic technician program at Bakersfield College in which a student may major in five areas - geologic drafting, land and legal, geologic assistant, engineering or paleontology. (RR)

Karp, Stanley E.

1970-01-01

320

Geological Time Scale  

NSDL National Science Digital Library

This document describes how geologic time is approached in discussions of geologic topics. The uses of relative time and absolute time are compared, and a geologic time scale is provided to represent both concepts. References are provided.

321

SPEECH CODING: FUNDAMENTALS AND APPLICATIONS  

E-print Network

EOT156 SPEECH CODING: FUNDAMENTALS AND APPLICATIONS MARK HASEGAWA-JOHNSON University of Illinois, California 1. INTRODUCTION Speech coding is the process of obtaining a compact representation of voice, speech coders have become essential components in telecommunications and in the multimedia infrastructure

Alwan, Abeer

322

West's Geology Resources  

NSDL National Science Digital Library

This is one of the world's largest geological web sites, with more than 200 web pages comprised of geological field guides, with hundreds of full screen color photographs of varied geological features, and with associated bibliographies. All of the field guides are for geologic locations in England. Also included is a large directory of internet sites sorted by topic. Topics range from mineral and rock types, to geologic time periods, fossils, plate tectonics, geochronology, mapping, and geologic surveys.

Ian West

323

MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT)  

USGS Publications Warehouse

SEAWAT-2000 is the latest release of the SEAWAT computer program for simulation of three-dimensional, variable-density, transient ground-water flow in porous media. SEAWAT-2000 was designed by combining a modified version of MODFLOW-2000 and MT3DMS into a single computer program. The code was developed using the MODFLOW-2000 concept of a process, which is defined as ?part of the code that solves a fundamental equation by a specified numerical method.? SEAWAT-2000 contains all of the processes distributed with MODFLOW-2000 and also includes the Variable-Density Flow Process (as an alternative to the constant-density Ground-Water Flow Process) and the Integrated MT3DMS Transport Process. Processes may be active or inactive, depending on simulation objectives; however, not all processes are compatible. For example, the Sensitivity and Parameter Estimation Processes are not compatible with the Variable-Density Flow and Integrated MT3DMS Transport Processes. The SEAWAT-2000 computer code was tested with the common variable-density benchmark problems and also with problems representing evaporation from a salt lake and rotation of immiscible fluids.

Langevin, Christian D.; Shoemaker, W. Barclay; Guo, Weixing

2003-01-01

324

Mass Wasting and Ground Collapse in Terrains of Volatile-Rich Deposits as a Solar System-Wide Geological Process: The Pre-Galileo View  

NASA Technical Reports Server (NTRS)

The polar terrains of Mars are covered in many places with irregular pits and retreating scarps, as are some of the surfaces of the outer-planet satellites. These features are interpreted by us as diagnostic of exogenic degradation due to the loss of a volatile rock-forming matrix or cement. In this study we propose that sublimation degradation is a plausible Solar Systemwide geological process. Candidate examples have been identified on Mars, Io, and Triton, and possibly Europa and Ganymede. We envision this process as having two end-member expressions (pits and scarps), for which we hypothesize two end-member mechanisms (massive localized lenses and areally extensive basal layers). In this study we focus on the role this process may play on the surfaces of the galilean satellites. Our principle modeling results are that for these satellites, H2S, CO2, and NH3 are the only viable candidate volatiles for sublimation degradation of landforms, in light of galilean satellite cosmochemistry. For Io's polar regions only H2S, and then only from slopes that face the Sun and have thin lags, is volatile enough to cause the observed sublimation-induced erosion at those latitudes. SO2 is not a viable candidate as an agent of erosion, especially for these polar landforms. In the case of Europa, only CO2 and H2S are viable candidates (given surface age constraints). Both species could be efficient eroders in nonpolar regions. H2S could generate erosion within the polar regions if the deposition and erosion conditions were essentially identical as those we invoked for Io's polar regions. For Ganymede (and Callisto) NH3 might be an agent of erosion in equatorial terrains of great age. The sublimation of CO2 and H2S is much more robust than NH3. The much slower rate of sublimation degradation from NH3 might be detectable by Galileo and used as a compositional indicator.

Moore, Jeffrey M.; Mellon, Michael T.; Zent, Aaron P.

1996-01-01

325

Geologic processes in the RWMC area, Idaho National Engineering Laboratory: Implications for long term stability and soil erosion at the radioactive waste management complex  

SciTech Connect

The Radioactive Waste Management Complex (RWMC) is the disposal and storage facility for low-level radioactive waste at the Idaho National Engineering Laboratory (INEL). Transuranic waste and mixed wastes were also disposed at the RWMC until 1970. It is located in the southwestern part of the INEL about 80 km west of Idaho Falls, Idaho. The INEL occupies a portion of the Eastern Snake River Plain (ESRP), a low-relief, basalt, and sediment-floored basin within the northern Rocky Mountains and northeastern Basin and Range Province. It is a cool and semiarid, sagebrush steppe desert characterized by irregular, rolling terrain. The RWMC began disposal of INEL-generated wastes in 1952, and since 1954, wastes have been accepted from other Federal facilities. Much of the waste is buried in shallow trenches, pits, and soil vaults. Until about 1970, trenches and pits were excavated to the basalt surface, leaving no sediments between the waste and the top of the basalt. Since 1970, a layer of sediment (about 1 m) has been left between the waste and the basalt. The United States Department of Energy (DOE) has developed regulations specific to radioactive-waste disposal, including environmental standards and performance objectives. The regulation applicable to all DOE facilities is DOE Order 5820.2A (Radioactive Waste Management). An important consideration for the performance assessment of the RWMC is the long-term geomorphic stability of the site. Several investigators have identified geologic processes and events that could disrupt a radioactive waste disposal facility. Examples of these {open_quotes}geomorphic hazards{close_quotes} include changes in stream discharge, sediment load, and base level, which may result from climate change, tectonic processes, or magmatic processes. In the performance assessment, these hazards are incorporated into scenarios that may affect the future performance of the RWMC.

Hackett, W.R.; Tullis, J.A.; Smith, R.P. [and others

1995-09-01

326

On the potential vegetation feedbacks that enhance phosphorus availability - insights from a process-based model linking geological and ecological timescales  

NASA Astrophysics Data System (ADS)

In old and heavily weathered soils, the availability of P might be so small that the primary production of plants is limited. However, plants have evolved several mechanisms to actively take up P from the soil or mine it to overcome this limitation. These mechanisms involve the active uptake of P mediated by mycorrhiza, biotic de-occlusion through root clusters, and the biotic enhancement of weathering through root exudation. The objective of this paper is to investigate how and where these processes contribute to alleviate P limitation on primary productivity. To do so, we propose a process-based model accounting for the major processes of the carbon, water, and P cycles including chemical weathering at the global scale. Implementing P limitation on biomass synthesis allows the assessment of the efficiencies of biomass production across different ecosystems. We use simulation experiments to assess the relative importance of the different uptake mechanisms to alleviate P limitation on biomass production. We find that active P uptake is an essential mechanism for sustaining P availability on long timescales, whereas biotic de-occlusion might serve as a buffer on timescales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modelling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth), and that vegetation on old soils has a smaller biomass production rate when P becomes limiting. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological timescales under different environmental settings.

Buendía, C.; Arens, S.; Hickler, T.; Higgins, S. I.; Porada, P.; Kleidon, A.

2014-07-01

327

On the potential vegetation feedbacks that enhance phosphorus availability - insights from a process-based model linking geological and ecological time scales  

NASA Astrophysics Data System (ADS)

In old and heavily weathered soils, the availability of P might be so small that the primary production of plants is limited. However, plants have evolved several mechanisms to actively take up P from the soil or mine it to overcome this limitation. These mechanisms involve the active uptake of P mediated by mycorrhiza, biotic de-occlusion through root clusters, and the biotic enhancement of weathering through root exudation. The objective of this paper is to investigate how and where these processes contribute to alleviate P limitation on primary productivity. To do so, we propose a process-based model accounting for the major processes of the carbon, water, and P cycle including chemical weathering at the global scale. We use simulation experiments to assess the relative importance of the different uptake mechanisms to alleviate P limitation on biomass production. Implementing P limitation on biomass synthesis allows the assessment of the efficiencies of biomass production across different ecosystems. We find that active P-uptake is an essential mechanism for sustaining P availability on long time scales, whereas biotic de-occlusion might serve as a buffer on time scales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modeling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth), and that vegetation on older soils becomes P-limited leading to a smaller biomass production efficiency. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological time scales under different environmental settings.

Buendíia, C.; Arens, S.; Hickler, T.; Higgins, S. I.; Porada, P.; Kleidon, A.

2013-12-01

328

Geological structure, recharge processes and underground drainage of a glacierised karst aquifer system, Tsanfleuron-Sanetsch, Swiss Alps  

NASA Astrophysics Data System (ADS)

The relationships between stratigraphic and tectonic setting, recharge processes and underground drainage of the glacierised karst aquifer system ‘Tsanfleuron-Sanetsch’ in the Swiss Alps have been studied by means of various methods, particularly tracer tests (19 injections). The area belongs to the Helvetic nappes and consists of Jurassic to Palaeogene sedimentary rocks. Strata are folded and form a regional anticlinorium. Cretaceous Urgonian limestone constitutes the main karst aquifer, overlain by a retreating glacier in its upper part. Polished limestone surfaces are exposed between the glacier front and the end moraine of 1855/1860 (Little Ice Age); typical alpine karrenfields can be observed further below. Results show that (1) large parts of the area are drained by the Glarey spring, which is used as a drinking water source, while marginal parts belong to the catchments of other springs; (2) groundwater flow towards the Glarey spring occurs in the main aquifer, parallel to stratification, while flow towards another spring crosses the entire stratigraphic sequence, consisting of about 800 m of marl and limestone, along deep faults that were probably enlarged by mass movements; (3) the variability of glacial meltwater production influences the shape of the tracer breakthrough curves and, consequently, flow and transport in the aquifer.

Gremaud, Vivian; Goldscheider, Nico; Savoy, Ludovic; Favre, Gérald; Masson, Henri

2009-12-01

329

Old Geology and New Geology  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

Released 28 May 2003

Mangala Vallis one of the large outflow channels that channeled large quantities of water into the northern lowlands, long ago on geological timescales. This valley is one of the few in the southern hemisphere, as well as one of the few west of the Tharsis bulge. A closer look at the channel shows more recent weathering of the old water channel: the walls of the channel show small, dark slope streaks that form in dusty areas; and much of the surrounding terrain has subtle linear markings trending from the upper left to the lower right, which are probably features sculpted and streamlined by the wind. Geology still shapes the surface of Mars today, but its methods over the eons have changed.

Image information: VIS instrument. Latitude -6, Longitude 209.6 East (150.4 West). 19 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2003-01-01

330

GeoTemp™ 1.0: A MATLAB-based program for the processing, interpretation and modelling of geological formation temperature measurements  

NASA Astrophysics Data System (ADS)

The evaluation of potential and resources during geothermal exploration requires accurate and consistent temperature characterization and modelling of the sub-surface. Existing interpretation and modelling approaches of 1D temperature measurements are mainly focusing on vertical heat conduction with only few approaches that deals with advective heat transport. Thermal regimes are strongly correlated to rock and fluid properties. Currently, no consensus exists for the identification of the thermal regime and the analysis of such dataset. We developed a new framework allowing the identification of thermal regimes by rock formations, the analysis and modelling of wireline logging and discrete temperature measurements by taking into account the geological, geophysical and petrophysics data. This framework has been implemented in the GeoTemp software package that allows the complete thermal characterization and modelling at the formation scale and that provides a set of standard tools for the processing wireline and discrete temperature data. GeoTempTM operates via a user friendly graphical interface written in Matlab that allows semi-automatic calculation, display and export of the results. Output results can be exported as Microsoft Excel spreadsheets or vector graphics of publication quality. GeoTemp™ is illustrated here with an example geothermal application from Western Australia and can be used for academic, teaching and professional purposes.

Ricard, Ludovic P.; Chanu, Jean-Baptiste

2013-08-01

331

Geologic exploration of solar system  

Microsoft Academic Search

The processes that must have operated on the early Earth have been deduced from evidence from ancient surfaces of the Moon and planets. In particular, such comparative studies have demonstrated that only two geologic processes have been widespread throughout the history of the solar system: impact cratering and volcanism. Impact craters have formed throughout solar system history, indeed the planets

Wood

1987-01-01

332

Colorado Geological Survey  

NSDL National Science Digital Library

The Colorado Geological Survey (CGS) is an agency of state government within the Department of Natural Resources whose mission is to help reduce the impact of geologic hazards on the citizens of Colorado, to promote the responsible economic development of mineral and mineral fuel resources, to provide geologic insight into water resources, and to provide geologic advice and information to a variety of constituencies. This site contains extensive information about Colorado geology such as maps, a geologic time scale for the state, program information, and state field trip information. This site hosts the Avalanche Information Center which contains avalanche forecasting and education center details. Publications report on geologic hazards, land use, environmental geology, mineral resources, oil, gas, coal, geologic mapping and earthquake information for the state. There are online editions of RockTalk, which is a quarterly newsletter published by the Colorado Geological Survey dealing with all aspects of geology throughout the state of Colorado. Links are provided for more resources.

333

GEOLOGICAL CHARACTERISTICS  

E-print Network

CAPSULE DESCRIPTION: Ilmenite, hemo-ilmenite or titaniferous magnetite accumulations as cross-cutting lenses or dike-like bodies, Ia> ers or disseminations within anorthositiclgabbroicinoritic rocks. These deposits can be subdivided into an ilmenite subtype (anorthosite-hosted titanium-iron) and a titaniferous magnetite subtype (gabbro-anorthosite-hosted iron-titanium). TECTONIC SETTING: Commonly associated with anorthosite-gabbro-norite-monzonite (mangerite)charnockite granite (AMCG) suites that are conventionally interpreted to be anorogenic and/or extensional. Some of the iron-titanium deposits occur at continental margins related to island arc magmatism followed by an episode of erogenic compression. DEPOSITIONAL ENVIRONMENT i GEOLOGICAL SETTING: Deposits occur in intrusive complexes which typically are emplaced at deeper levels in the crust. Progressive differentiation of liquids residual from anorthosite-norite magmas leads to late stage intrusions enriched in Fe and Ti oxides and apatite. AGE OF MINERALIZATION: Mainly Mesoproterozoic (1.65 to 0.90 Ga) for the ihnenite deposits, but this may be a consequence of a particular combination of tectonic circumstances, rather than any a priori temporal control. The Fe-Ti deposits with titaniferous magnetite do not appear to be restricted in time. HOST/ASSOCIATED ROCKS: Hosted by massive, layered or zoned intrusive complexes- anorthosite, norite,

G. A. Gross; C. F. Gower; D. V. Lefebure; Commodities (byproducts) Ti

334

Arsenic in New Jersey Coastal Plain streams, sediments, and shallow groundwater: effects from different geologic sources and anthropogenic inputs on biogeochemical and physical mobilization processes  

USGS Publications Warehouse

Arsenic (As) concentrations in New Jersey Coastal Plain streams generally exceed the State Surface Water Quality Standard (0.017 micrograms per liter (µg/L)), but concentrations seldom exceed 1 µg/L in filtered stream-water samples, regardless of geologic contributions or anthropogenic inputs. Nevertheless, As concentrations in unfiltered stream water indicate substantial variation because of particle inputs from soils and sediments with differing As contents, and because of discharges from groundwater of widely varying chemistry. In the Inner Coastal Plain, streams draining to lower reaches of the Delaware River traverse As-rich glauconitic sediments of marine origin in which As contents typically are about 20 milligrams per kilogram (mg/kg) or greater. In some of these sedimentary units, As concentrations exceed the New Jersey drinking-water maximum contaminant level (5 µg/L) in shallow groundwater that discharges to streams. Microbes, fueled by organic carbon beneath the streambed, reduce iron (Fe) and As, releasing As and Fe into solution in the shallow groundwater from geologic materials that likely include (in addition to glauconite) other phyllosilicates, apatite, and siderite. When the groundwater discharges to the stream, the dissolved Fe and As are oxidized, the Fe precipitates as a hydroxide, and the As sorbs or co-precipitates with the Fe. Because of the oxidation/precipitation process, dissolved As concentrations measured in filtered stream waters of the Inner Coastal Plain are about 1 µg/L, but the total As concentrations (and loads) are greater, substantially amplified by As-bearing suspended sediment in stormflows. In the Outer Coastal Plain, streams draining to the Atlantic Ocean traverse quartz-rich sediments of mainly deltaic origin where the As content generally is low ( With a history of agriculture in the New Jersey Coastal Plain, anthropogenic inputs of As, such as residues from former pesticide applications in soils, can amplify any geogenic As in runoff. Such inputs contribute to an increased total As load to a stream at high stages of flow. As a result of yet another anthropogenic influence, microbes that reduce and mobilize As beneath the streambeds are stimulated by inputs of dissolved organic carbon (DOC). Although DOC is naturally occurring, anthropogenic contributions from wastewater inputs may deliver increased levels of DOC to subsurface soils and ultimately groundwater. Arsenic concentrations may increase with the increases in pH of groundwater and stream water in developed areas receiving wastewater inputs, as As mobilization caused by pH-controlled sorption and desorption reactions are likely to occur in waters of neutral or alkaline pH (for example, Nimick and others, 1998; Barringer and others, 2007b). Because of the difference in As content of the geologic materials in the two sub-provinces of the Coastal Plain, the amount of As that is mobile in groundwater and stream water is, potentially, substantially greater in the Inner Coastal Plain than in the Outer Coastal Plain. In turn, streams within the Inner and Outer Coastal Plain can receive substantially more As in groundwater discharge from developed areas than from environments where DOC appears to be of natural origin.

Barringer, Julia L.; Reilly, Pamela A.; Eberl, Dennis D.; Mumford, Adam C.; Benzel, William M.; Szabo, Zoltan; Shourds, Jennifer L.; Young, Lily Y.

2013-01-01

335

The Martian Geomorphology as mapped by the Mars Express High Resolution Stereo Camera (HRSC): Implications for Geological Processes and Climate Conditions.  

NASA Astrophysics Data System (ADS)

One major reason for exploring Mars is the similarity of surface features to those present on Earth. Among the most important are morphological and mineralogical indicators that liquid water has existed on Mars at various locations over the entire history of the planet, albeit in decreasing abundance with time. Due to the strong evidence for aqueous processes at or near the surface, Mars is the most Earth-like body in the Solar System. The HRSC instrument is designed to simultaneously map the morphology, topography, structure and geologic context of the surface as well as atmospheric phenomena [1]. After 10 years of ESA's Mars Express orbiting the planet its High Resolution Stereo Camera (HRSC) has covered about 90 % of the surface in stereo and color with resolutions up to 10 m/pixel. Digital elevation models of up to 30-50 m grid spacing [1], generated from all suitable datasets of the stereo coverage, currently cover about 40% of the surface [1,2]. The geomorphological analyses of surface features, observed by the HRSC indicate major surface modifications by endogenic and exogenic processes at all scales. Endogenic landforms (e.g., tectonic rifts, small basaltic shield volcanoes) were found to be very similar to their equivalents on Earth [1,3,4,5,6,7]. Volcanism may have been active up to the very recent past or even to the present, putting important constraints on thermal evolution models [6,7]. The analysis of diverse landforms produced by aqueous processes revealed that surface water activity was likely episodic, but ranged in age from very ancient to very recent [1,8-16]. Particularly important are prominent glacial and periglacial features at several latitudes, including mountain glaciers and a frozen sea [17-21]. The identification of aqueous alteration minerals and their geological context has enabled a better understanding of paleoenvironmental conditions and pedogenetic processes [23-25]. Dark dunes contain volcanic material and are evidence for the very dynamic surface environment, characterized by widespread erosion, transport, and redeposition [26]. References: [1]Jaumann et al., 2007, PSS 55; [2]Gwinner et al., 2010, EPSL 294; [3]Neukum et al., 2004, Nature 432; [4]Neukum et al., EPSL 294;[5] Hauber et al., 2005, Nature 434; [6]Hauber et al., 2009 PSS 57; [7]Platz and Michael, 2011, EPSL 312, [8]Jaumann et al., 2005, GRL 32; [9]Jaumann et al., 2010, EPSL 294; [10]Erkeling et al., 2010, EPSL 294; [11]Erkeling et al., 2012, Icarus, 219; [12]Kleinhans et al., 2010, EPSL 294; [13]Reiss et al., 2009, PSS 57; [14]Kneissl et al., 2010, EPSL 294; [15]Di Achille et al., 2006, JGR 111; [16]Di Achille et al., 2006, GRL 33; [17]Head et al., 2005 Nature 434; [18]Murray et al., 2005 Nature 434; [19]Pacifici et al., 2009, Icarus 202; [20]Rossi et al., 2011, Geol. Soc. Am.356; [21]Marchant and Head, 2007, Icarus; [22]Ulrich et al., 2011 Geomorphology 134;[23] Le Deit et al., 2010, Icarus 208; [24]Le Deit et al., 2012, JGR 117; [25]Bishop et al., 2013, JGR 118; [26]Tirsch et al., 2011, JGR 116;

Jaumann, Ralf

2014-05-01

336

Fundamentals of preparative and nonlinear chromatography  

SciTech Connect

The second edition of Fundamentals of Preparative and Nonlinear Chromatography is devoted to the fundamentals of a new process of purification or extraction of chemicals or proteins widely used in the pharmaceutical industry and in preparative chromatography. This process permits the preparation of extremely pure compounds satisfying the requests of the US Food and Drug Administration. The book describes the fundamentals of thermodynamics, mass transfer kinetics, and flow through porous media that are relevant to chromatography. It presents the models used in chromatography and their solutions, discusses the applications made, describes the different processes used, their numerous applications, and the methods of optimization of the experimental conditions of this process.

Guiochon, Georges A [ORNL; Felinger, Attila [ORNL; Katti, Anita [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Shirazi, Dean G [unknown

2006-02-01

337

Pristine Noachian crust and key geologic transitions in the lower walls of Valles Marineris: Insights into early igneous processes on Mars  

NASA Astrophysics Data System (ADS)

Valles Marineris is a unique vertical section through the uppermost kilometers of the martian crust. Its location, east of the Tharsis bulge, and its water-related history, fuel a great diversity of rock types in this area (Carr, M.H., Head, J.W. [2010]. Earth Planet. Sci. Lett. 294, 185-203). HiRISE and CRISM data available over the walls of the canyon were analyzed to infer the importance of magmatic and sedimentary processes through time. This contribution provides a complete morphologic and mineralogic characterization of the cross-section of rocks exposed in the canyon walls. Low-calcium pyroxene and olivine are detected in the lower portion of the walls, in association with morphologically distinct outcrops, leading to the idea that pristine Noachian crust might be exposed. Phyllosilicates are also present within the walls, but they appear to correspond to an alteration product. No proper sedimentary layers were observed within the walls of Valles Marineris at the resolution available today. All these detections are limited to the eastern portion of Valles Marineris, especially Juventae, Coprates, Capri, and Ganges chasmata. Preserved Noachian crustal material is rare on the martian surface and is rarely exposed in its pristine geologic context. Such detections lend precious information about early igneous processes. This survey also supports observations from the nearby impact crater central peaks (Quantin, C., Flahaut, J., Allemand, P. [2009]. Lunar Planet. Sci. 10; Quantin, C., Flahaut, J., Clenet, H., Allemand, P., Thomas, P. [2011]. Icarus, submitted for publication) and suggests that the western part of Valles Marineris may be cut into another material, consistent with lavas or volcanic sediments.

Flahaut, Jessica; Quantin, Cathy; Clenet, Harold; Allemand, Pascal; Mustard, John F.; Thomas, Pierre

2012-09-01

338

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory: Processing, taxonomy, and quality control of benthic macroinvertebrate samples  

NSDL National Science Digital Library

This US Geological Survey Open-File Report (00-212) describes analytical techniques for benthic macroinvertebrates. Available in .pdf format, the 49-page report includes information on such analytical techniques as chemical equipment supplies, taxonomic identification, and more.

2000-01-01

339

Public Acceptance for Geological CO2Storage  

Microsoft Academic Search

Public acceptance is one of the fundamental prerequisites for geological CO2 storage. In highly populated areas like central Europe, especially in the vicinity of metropolitan areas like Berlin, underground operations are in the focus of the people living next to the site, the media, and politics. To gain acceptance, all these groups - the people in the neighbourhood, journalists, and

F. Schilling; F. Ossing; H. Würdemann

2009-01-01

340

The Development of a Performance Assessment Framework for Geologic CO2 Sequestration  

NASA Astrophysics Data System (ADS)

Large-scale implementation of geologic storage in the U.S. implies seals with a cumulative area amounting to hundreds of square kilometers per year and will require a large number of storage sites. These factors highlight the need for a robust and reliable method for evaluating the suitability of specific sites to ensure that they will perform to required goals. This method must address fundamental physics and chemistry over a large range in scale and must address uncertainties both in these phenomena and in the properties of the reservoir. In addition, the method must link these fundamental scientific inputs to decisions based on a required goal (e.g. <0.01% of CO2 released per year). The Zero Emissions Research and Technology (ZERT) project at the Los Alamos National Laboratory is studying the injection of CO2 into geologic repositories. We have developed a coupled process-system model that is intended to evaluate critical pathways for CO2 transport in the system and MMV challenges/strategies associated with those pathways. In order for the systems model to be valid it must be supported by process level models that address the fundamental physics and chemistry at the appropriate scale. This study discusses upscaling and abstraction methods that link the process level models to the systems model CO2-PENS. Our approach has been to identify the key processes in each of the subsystems in geologic storage (reservoir to surface). In developing the framework, we are focusing in several specific subsystems: wellbore integrity, fracture/fault integrity, saturated zone interactions, terrestrial ecosystems and atmospheric processes. This talk will focus on the general framework and the abstraction process for incorporating process level information into the systems model for each of these subsystems. A poster by Stauffer et al. describes the CO2-PENS systems model in greater detail.

Viswanathan, H. S.; Stauffer, P. H.; Guthrie, G. D.; Pawar, R. J.; Kaszuba, J. P.; Carey, J. W.; Lichtner, P. C.; Ziock, H. J.; Dubey, M. K.; Olsen, S. C.; Chipera, S. J.; Fessenden-Rahn, J.

2005-12-01

341

REMOTE SENSING GEOLOGICAL SURVEY  

E-print Network

REMOTE SENSING IN GEOLOGICAL SURVEY OF BRAZIL August/2010 Mônica Mazzini Perrotta Remote Sensing Division Head #12;SUMMARY The Geological Survey of Brazil mission The Remote Sensing Division Main remote sensing data used in CPRM geologic projects Future perspective: the Spectral Library of Geological Survey

342

Maryland Geological Survey  

NSDL National Science Digital Library

The Maryland Geological Survey (MGS) homepage contains information from MGS programs on hydrogeology, hydrology, coastal and estuarine geology, environmental geology and mineral resources; an online guide to Maryland geology; and information on oyster habitat restoration projects. There are also maps, data, information on MGS publications, MGS news, and online educational resources.

343

History of Geology.  

ERIC Educational Resources Information Center

Discusses: (1) geologists and the history of geology; (2) American historians and the history of geology; (3) history of geology in the 1980s; (4) sources for the history of geology (bibliographies, dictionaries, encyclopedias, handbooks, periodicals, public/official histories, compilations, and books); (5) research opportunities; and (6) other…

Greene, Mott T.

1985-01-01

344

GEOLOGY (GEOL) Robinson Foundation  

E-print Network

177Geology GEOLOGY (GEOL) Robinson Foundation PROFESSOR HARBOR ASSOCIATE PROFESSORS KNAPP, CONNORS ASSISTANT PROFESSORS GREER, RAHL MAJORS BACHELOR OF SCIENCE A major in geology leading to a Bachelor of Science degree consists of 50 credits as follows: 1. Geology 160, 185, 211, 311, 330, 350

Dresden, Gregory

345

Geologic investigations of the WIPP Site: overview and issues  

Microsoft Academic Search

The Waste Isolation Pilot Plant (WIPP) is planned for the disposal of defense waste in bedded salt of southeastern New Mexico. Since 1975, the geologic investigations have progressed through preliminary site selection and geologic characterization phases and are now primarily concerned with the long-term geological processes that may affect the site. These processes are grouped by hydrology, dissolution, geochemical, tectonic,

1981-01-01

346

Geologic Maps and Mapping  

NSDL National Science Digital Library

This portal provides access to resources on geologic mapping, and to sources of geologic maps. There is an introduction to geologic mapping, which summarizes its principles and practices, and a history of United States Geological Survey (USGS) mapping activities from 1879 to the present, as well as links to papers on the values and hazards associated with geologic maps and mapping. Online sources of maps include the USGS Geologic Map Database, other federal map products (FEDMAP), state geological survey products (STATEMAP), and university map products (EDMAP).

347

Tennessee Division of Geology  

NSDL National Science Digital Library

This is the homepage of the Geology Division of the Tennessee Department of Environment and Conservation. It provides information on the division's programs, including geologic hazards research, public service, education programs, basic and applied research on geology and mineral resources, publication of geologic information, permitting of oil and gas wells, and regulation of Tennessee's oil and gas industry. Materials include a catalog of publications, maps, geologic bulletins, and the Public Information series of pamphlets; the Geology Division Newsletter; and information on the state's mineral industry. There is also a section on the Gray Fossil Site, an unusual assemblage of fossils and sedimentary geology encountered during road construction near the town of Gray, Tenessee.

348

Fractals in geology and geophysics  

NASA Technical Reports Server (NTRS)

The definition of a fractal distribution is that the number of objects N with a characteristic size greater than r scales with the relation N of about r exp -D. The frequency-size distributions for islands, earthquakes, fragments, ore deposits, and oil fields often satisfy this relation. This application illustrates a fundamental aspect of fractal distributions, scale invariance. The requirement of an object to define a scale in photograhs of many geological features is one indication of the wide applicability of scale invariance to geological problems; scale invariance can lead to fractal clustering. Geophysical spectra can also be related to fractals; these are self-affine fractals rather than self-similar fractals. Examples include the earth's topography and geoid.

Turcotte, Donald L.

1989-01-01

349

Regional Geologic History of the Polar Regions of Mars  

NASA Astrophysics Data System (ADS)

Geologic mapping and topical studies of the martian polar regions based on Mariner 9 and Viking data have identified major geologic units and structures and their formational sequence. However, several fundamental questions remain poorly answered, such as: (1) What has been the history of ice and dust deposits at the poles and their subsequent modification over geologic time? (2) Is their a signature of melting and discharge from any polar deposits? (3) Can long-term or sporadic climatic and geologic changes of global significance be detected in the polar geologic records? (4) How have volcanism, tectonism, and impacts been involved in the geologic evolution of the polar regions? Here we discuss how these questions are currently being re-examined with Mars Global Surveyor data and new geologic mapping of the polar regions. Additional information is contained in the original extended abstract.

Tanaka, K. L.; Kolb, E. J.

2000-08-01

350

GWM-a ground-water management process for the U.S. Geological Survey modular ground-water model (MODFLOW-2000)  

USGS Publications Warehouse

GWM is a Ground?Water Management Process for the U.S. Geological Survey modular three?dimensional ground?water model, MODFLOW?2000. GWM uses a response?matrix approach to solve several types of linear, nonlinear, and mixed?binary linear ground?water management formulations. Each management formulation consists of a set of decision variables, an objective function, and a set of constraints. Three types of decision variables are supported by GWM: flow?rate decision variables, which are withdrawal or injection rates at well sites; external decision variables, which are sources or sinks of water that are external to the flow model and do not directly affect the state variables of the simulated ground?water system (heads, streamflows, and so forth); and binary variables, which have values of 0 or 1 and are used to define the status of flow?rate or external decision variables. Flow?rate decision variables can represent wells that extend over one or more model cells and be active during one or more model stress periods; external variables also can be active during one or more stress periods. A single objective function is supported by GWM, which can be specified to either minimize or maximize the weighted sum of the three types of decision variables. Four types of constraints can be specified in a GWM formulation: upper and lower bounds on the flow?rate and external decision variables; linear summations of the three types of decision variables; hydraulic?head based constraints, including drawdowns, head differences, and head gradients; and streamflow and streamflow?depletion constraints. The Response Matrix Solution (RMS) Package of GWM uses the Ground?Water Flow Process of MODFLOW to calculate the change in head at each constraint location that results from a perturbation of a flow?rate variable; these changes are used to calculate the response coefficients. For linear management formulations, the resulting matrix of response coefficients is then combined with other components of the linear management formulation to form a complete linear formulation; the formulation is then solved by use of the simplex algorithm, which is incorporated into the RMS Package. Nonlinear formulations arise for simulated conditions that include water?table (unconfined) aquifers or head?dependent boundary conditions (such as streams, drains, or evapotranspiration from the water table). Nonlinear formulations are solved by sequential linear programming; that is, repeated linearization of the nonlinear features of the management problem. In this approach, response coefficients are recalculated for each iteration of the solution process. Mixed?binary linear (or mildly nonlinear) formulations are solved by use of the branch and bound algorithm, which is also incorporated into the RMS Package. Three sample problems are provided to demonstrate the use of GWM for typical ground?water flow management problems. These sample problems provide examples of how GWM input files are constructed to specify the decision variables, objective function, constraints, and solution process for a GWM run. The GWM Process runs with the MODFLOW?2000 Global and Ground?Water Flow Processes, but in its current form GWM cannot be used with the Observation, Sensitivity, Parameter?Estimation, or Ground?Water Transport Processes. The GWM Process is written with a modular structure so that new objective functions, constraint types, and solution algorithms can be added.

Ahlfeld, David P.; Barlow, Paul M.; Mulligan, Anne E.

2005-01-01

351

SURVEY GUIDE SURVEY FUNDAMENTALS  

E-print Network

SURVEY GUIDE 1 SURVEY FUNDAMENTALS A GUIDE TO DESIGNING AND IMPLEMENTING SURVEYS #12;S U R V E Y GU I D E OFFICE OF QUALITY IMPROVEMENT SURVEY FUNDAMENTALS This guide describes in non-technical terms the underlying principles of good survey design and implementation. Clear, simple explanations lead the reader

Shapiro, Vadim

352

Fundamental Physical Constants  

National Institute of Standards and Technology Data Gateway

SRD 121 CODATA Fundamental Physical Constants (Web, free access)   This site, developed in the Physics Laboratory at NIST, addresses three topics: fundamental physical constants, the International System of Units (SI), which is the modern metric system, and expressing the uncertainty of measurement results.

353

Fundamentals of the Dwarf Fundamental Plane  

E-print Network

Star-forming dwarfs are studied to elucidate the physical underpinnings of their fundamental plane. It is confirmed that residuals in the Tully-Fisher relation are correlated with surface brightness, but that even after accommodating the surface brightness dependence through the dwarf fundamental plane, residuals in absolute magnitude are far larger than expected from observational errors. Rather, a more fundamental plane is identified which connects the potential to HI line width and surface brightness. Residuals correlate with the axis ratio in a way which can be accommodated by recognizing the galaxies to be oblate spheroids viewed at varying angles. Correction of surface brightnesses to face-on leads to a correlation among the potential, line width, and surface brightness for which residuals are entirely attributable to observational uncertainties. The mean mass-to-light ratio of the diffuse component of the galaxies is constrained to be 0.88 +/- 0.20 in Ks. Blue compact dwarfs lie in the same plane as dw...

McCall, Marshall L; Nunez, F Pozo; Dominguez, A Barr; Fingerhut, R; Unda-Sanzana, E; Li, Bintao; Albrecht, M; 10.1051/0004-6361/201117669

2012-01-01

354

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; processing, taxonomy, and quality control of benthic macroinvertebrate samples  

USGS Publications Warehouse

Qualitative and quantitative methods to process benthic macroinvertebrate (BMI) samples have been developed and tested by the U.S. Geological Survey?s National Water Quality Laboratory Biological Group. The qualitative processing method is based on visually sorting a sample for up to 2 hours. Sorting focuses on attaining organisms that are likely to result in taxonomic identifications to lower taxonomic levels (for example, Genus or Species). Immature and damaged organisms are also sorted when they are likely to result in unique determinations. The sorted sample remnant is scanned briefly by a second person to determine if obvious taxa were missed. The quantitative processing method is based on a fixed-count approach that targets some minimum count, such as 100 or 300 organisms. Organisms are sorted from randomly selected 5.1- by 5.1-centimeter parts of a gridded subsampling frame. The sorted remnant from each sample is resorted by a second individual for at least 10 percent of the original sort time. A large-rare organism search is performed on the unsorted remnant to sort BMI taxa that were not likely represented in the sorted grids. After either qualitatively or quantitatively sorting the sample, BMIs are identified by using one of three different types of taxonomic assessment. The Standard Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol III and typically provides Genus- or Species-level taxonomic resolution. The Rapid Taxonomic Assessment is comparable to the U.S. Environmental Protection Agency Rapid Bioassessment Protocol II and provides Familylevel and higher taxonomic resolution. The Custom Taxonomic Assessment provides Species-level resolution whenever possible for groups identified to higher taxonomic levels by using the Standard Taxonomic Assessment. The consistent use of standardized designations and notes facilitates the interpretation of BMI data within and among water-quality studies. Taxonomic identifications are quality assured by verifying all referenced taxa and randomly reviewing 10 percent of the taxonomic identifications performed weekly by Biological Group taxonomists. Taxonomic errors discovered during this review are corrected. BMI data are reviewed for accuracy and completeness prior to release. BMI data are released phylogenetically in spreadsheet format and unprocessed abundances are corrected for laboratory and field subsampling when necessary.

Moulton, Stephen R., II; Carter, James L.; Grotheer, Scott A.; Cuffney, Thomas F.; Short, Terry M.

2000-01-01

355

Introduction Systems Engineering Fundamentals ENGINEERING  

E-print Network

Introduction Systems Engineering Fundamentals i SYSTEMS ENGINEERING FUNDAMENTALS January 2001;Systems Engineering Fundamentals Introduction ii #12;Introduction Systems Engineering Fundamentals iii ............................................................................................................................................. iv PART 1. INTRODUCTION Chapter 1. Introduction to Systems Engineering Management

Rhoads, James

356

Geologic mapping of Vesta  

NASA Astrophysics Data System (ADS)

We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft's High-Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn's arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a system of deep, globe-girdling equatorial troughs and ridges, as well as an older system of troughs and ridges to the north. Troughs and ridges are also evident cutting across, and spiraling arcuately from, the Rheasilvia central mound. However, no volcanic features have been unequivocally identified. Vesta can be divided very broadly into three terrains: heavily-cratered terrain; ridge-and-trough terrain (equatorial and northern); and terrain associated with the Rheasilvia crater. Localized features include bright and dark material and ejecta (some defined specifically by color); lobate deposits; and mass-wasting materials. No obvious volcanic features are evident. Stratigraphy of Vesta's geologic units suggests a history in which formation of a primary crust was followed by the formation of impact craters, including Veneneia and the associated Saturnalia Fossae unit. Formation of Rheasilvia followed, along with associated structural deformation that shaped the Divalia Fossae ridge-and-trough unit at the equator. Subsequent impacts and mass wasting events subdued impact craters, rims and portions of ridge-and-trough sets, and formed slumps and landslides, especially within crater floors and along crater rims and scarps. Subsequent to the formation of Rheasilvia, discontinuous low-albedo deposits formed or were emplaced; these lie stratigraphically above the equatorial ridges that likely were formed by Rheasilvia. The last features to be formed were craters with bright rays and other surface mantling deposits. Executed progressively throughout data acquisition, the iterative mapping process provided the team with geologic proto-units in a timely manner. However, interpretation of the resulting map was hampered by the necessity to provide the team with a standard nomenclature and symbology early in the process. With regard to mapping and interpreting units, the mapping process was hindered by the lack of calibrated mineralogic information. Topography and shadow played an important role in discriminating features and terrains, especially in the early stages of data acquisition.

Yingst, R. A.; Mest, S. C.; Berman, D. C.; Garry, W. B.; Williams, D. A.; Buczkowski, D.; Jaumann, R.; Pieters, C. M.; De Sanctis, M. C.; Frigeri, A.; Le Corre, L.; Preusker, F.; Raymond, C. A.; Reddy, V.; Russell, C. T.; Roatsch, T.; Schenk, P. M.

2014-11-01

357

National Park Service: Tour of Park Geology  

NSDL National Science Digital Library

The tour of Park geologic resources includes pages specific to individual National Parks, Monuments, Recreation Areas, Preserves, Seacoasts, Reserves, and Recreation Areas. These pages are indexed by park name, state, or by one of the following topics: basin and range, caves, Colorado Plateau, fossils, glaciers, hot springs, human use, mountain building, oldest rocks, plate tectonics, river systems, sand dunes, shoreline geology, or volcanoes. Organization of each of the pages typically follows a NPS template with categories for park geology, maps, photographs, geologic research, related links, visitor information, multimedia, and "teacher features" (educational resources and links for teaching geology with National Park examples.) Common subjects that are addressed at various park sites include: minerals, rocks, fossils, cave and karst systems, coastlines, glaciers, volcanoes, faults, landforms, landslides, structures, fluvial systems, sediments, soils, stratigraphic relations, processes that form or act on geologic features and their chemical compositions, and the history of the planet and its life forms.

358

Marine Geology: Research Beneath the Sea  

NSDL National Science Digital Library

This report by the United States Geological Survey (USGS) details the history of marine geology. The scope of this field, tools and equipment used, and methods of study are covered. The report also discusses resource potential of the marine environment, plate tectonics, the effects of marine processes, and new frontiers intended to expand our understanding of the oceans.

359

SCOPE: IEEE Signal Processing Magazine publishes tutorial-style articles on signal processing research and applications, as well as columns and forums of interest to the signal processing community. Coverage ranges from fundamental principles to practical  

E-print Network

[CONTENTS] SCOPE: IEEE Signal Processing Magazine publishes tutorial-style articles on signal MAGAZINE (ISSN 1053-5888) (ISPREG) is published bimonthly by the Institute of Electrical and Electronics of U.S. Copyright Law for private use of patrons: (1) those post-1977 articles that carry a code

Nehorai, Arye

360

Glossary of Geologic Terms  

NSDL National Science Digital Library

This page from Iowa State University presents a general glossary of geologic terms. The site would be a good reference for geology coursework. This glossary of geologic terms is based on the glossary in Earth: An Introduction to Geologic Change, by S. Judson and S.M. Richardson (Englewood Cliffs, NJ, Prentice Hall, 1995). Where possible, definitions conform generally, and in some cases specifically, to definitions given in Robert L Bates and Julia A Jackson (editors), Glossary of Geology, 3rd ed., American Geological Institute, Alexandria, Virginia, 1987.

361

Weird Geology: The Devil's Tower  

NSDL National Science Digital Library

This page features a brief introduction to the several theories about the geological processes that formed Devil's Tower, which rises 1,267 feet above the nearby Belle Fourche River and is still considered a sacred place by some Native American Tribes. Information on climbing the tower as well as images and a cross section are provided.

Lee Krystek

362

Fundamentals of Petroleum.  

ERIC Educational Resources Information Center

Basic information on petroleum is presented in this book prepared for naval logistics officers. Petroleum in national defense is discussed in connection with consumption statistics, productive capacity, world's resources, and steps in logistics. Chemical and geological analyses are made in efforts to familiarize methods of refining, measuring,…

Bureau of Naval Personnel, Washington, DC.

363

Plate motions: fundamentals  

E-print Network

lithospheric plates" · Plate tectonics = a kinematic theory ­ Rigid plates (no intraplate deformation") · Convergent = subductions ("trenches") · Strike-slip = transform faults · Plate tectonics describesPlate motions: fundamentals · Assume a pie-shaped wedge plate B, rotating around E (=rotation pole

Déverchère, Jacques

364

Fundamental strings in SFT  

E-print Network

In this letter we show that vacuum string field theory contains exact solutions that can be interpreted as macroscopic fundamental strings. They are formed by a condensate of infinitely many completely space-localized solutions (D0-branes).

Bonora, L; Santos, R J S; Tolla, D D

2005-01-01

365

Fundamental strings in SFT  

Microsoft Academic Search

In this Letter we show that vacuum string field theory contains exact solutions that we propose to interpret as macroscopic fundamental strings. They are formed by a condensate of infinitely many completely space-localized solutions (D0-branes).

L. Bonora; C. Maccaferri; R. J. Scherer Santos; D. D. Tolla

2005-01-01

366

Fundamental strings in SFT  

E-print Network

In this letter we show that vacuum string field theory contains exact solutions that can be interpreted as macroscopic fundamental strings. They are formed by a condensate of infinitely many completely space-localized solutions (D0-branes).

L. Bonora; C. Maccaferri; R. J. Scherer Santos; D. D. Tolla

2005-01-14

367

Fundamentals of NMR  

NSDL National Science Digital Library

This e-text presents an introduction to the fundamentals of NMR covering magnetic resonance, pulsed NMR, relaxation, chemical shift, spin-spin coupling, the nuclear Overhauser effect and chemical exchange. The document may be downloaded in PDF format.

James, Thomas L.

368

Relativity in fundamental astronomy  

NASA Astrophysics Data System (ADS)

An overview is given over the broad field of Relativity in Fundamental Astronomy. The present status is recalled and deficiencies are pointed out that might lead to future work within IAU Commission 52.

Soffel, M.

2015-03-01

369

Fundamental Aeronautics Hypersonics Project  

E-print Network

for the National Aeronautics and Space Administration (NASA) Aeronautics Research Mission Directorate (ARMDFundamental Aeronautics Hypersonics Project Reference Document Principal Investigator: James and detailed content of a comprehensive Fundamental Aeronautics Hypersonics research project. It contains

370

Relative Geologic Time and the Geologic Time Scale  

NSDL National Science Digital Library

Students are given a short introduction to fossils, strata, Steno's law of superposition, and the development of the geologic time scale from initial description of systems, through the realization that fossils could be used to correlate between systems, to the assembly of the modern geologic time scale. Then, each student in the course is given a sheet of paper with a simple stratigraphic column and associated fossils representing a geologic system on one side and a short description of the location and history of discovery of the system on the other. On a large wall, students then assemble four geologic columns from their systems representing mainland Europe, Great Britain, the Eastern U.S. and the Western U.S. using the fossils illustrated on their sheets to correlate systems. The instructor guides this process by placing the first system on the wall and by providing some narration as the columns take shape. Europe and Great Britain are assembled first, one sheet at a time, providing when completed the framework of the modern geologic time scale. Once this is up on the wall, the remaining students can assemble the other two columns in minutes using fossils to correlate between American and European systems. A temporal gap in the Grand Canyon sequence provides an opportunity to discuss the incompleteness of the rock record in any one place and a system composed of igneous and metamorphic rocks with no fossils is used to point out the difference between radiometric (absolute) and biostratigraphic (relative) dating.

Bret Bennington

371

Geology on a Sand Budget  

NSDL National Science Digital Library

Earth science teaches know how frustrating it can be to spend hundreds of dollars on three-dimensional (3-D) models of Earth's geologic features, only to use the models for a few class periods. To avoid emptying an already limited science budget, teachers can use a simple alternative to the expensive 3-D models--sand. Modeling geologic processes and features with sand is an effective way for teachers to promote student understanding of Earth science topics, quickly assess students' prior knowledge, and identify common misconceptions.

Jacqueline Kane

2004-09-01

372

A Geological Wonder: Niagara Falls  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 9-12. It focuses on the geological history of the Niagara Falls area, as well as the physical and geological processes that have formed this region. It includes objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. There are videos available to order which complement this lesson, audio vocabulary, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

373

Geological Sciences 330 Fall 2007 Sedimentary Geology  

E-print Network

: Sediments and Sedimentary Rocks Week 3 17 Sept Sedimentary Textures and Rock Classification 19 Sept Fluid Dynamics (2 & 3) Lab 2: Sedimentary Rock Classification Week 4 24 Sept Sediment Entrainment and DepositionGeological Sciences 330 Fall 2007 Sedimentary Geology This course is intended to provide

374

Geophysics & Geology Inspected.  

ERIC Educational Resources Information Center

Summarizes findings of a recently published report of the Canadian Geoscience Council, which includes the following topics regarding college geology: facilities; teaching; undergraduate enrollments; postgraduate enrollments; geologic research; and integration of Canadian geoscience with other countries. (CS)

Neale, E. R. W.

1981-01-01

375

New Quasar Studies Keep Fundamental Physical Constant Constant  

NASA Astrophysics Data System (ADS)

Very Large Telescope sets stringent limit on possible variation of the fine-structure constant over cosmological time Summary Detecting or constraining the possible time variations of fundamental physical constants is an important step toward a complete understanding of basic physics and hence the world in which we live. A step in which astrophysics proves most useful. Previous astronomical measurements of the fine structure constant - the dimensionless number that determines the strength of interactions between charged particles and electromagnetic fields - suggested that this particular constant is increasing very slightly with time. If confirmed, this would have very profound implications for our understanding of fundamental physics. New studies, conducted using the UVES spectrograph on Kueyen, one of the 8.2-m telescopes of ESO's Very Large Telescope array at Paranal (Chile), secured new data with unprecedented quality. These data, combined with a very careful analysis, have provided the strongest astronomical constraints to date on the possible variation of the fine structure constant. They show that, contrary to previous claims, no evidence exist for assuming a time variation of this fundamental constant. PR Photo 07/04: Relative Changes with Redshift of the Fine Structure Constant (VLT/UVES) A fine constant To explain the Universe and to represent it mathematically, scientists rely on so-called fundamental constants or fixed numbers. The fundamental laws of physics, as we presently understand them, depend on about 25 such constants. Well-known examples are the gravitational constant, which defines the strength of the force acting between two bodies, such as the Earth and the Moon, and the speed of light. One of these constants is the so-called "fine structure constant", alpha = 1/137.03599958, a combination of electrical charge of the electron, the Planck constant and the speed of light. The fine structure constant describes how electromagnetic forces hold atoms together and the way light interacts with atoms. But are these fundamental physical constants really constant? Are those numbers always the same, everywhere in the Universe and at all times? This is not as naive a question as it may seem. Contemporary theories of fundamental interactions, such as the Grand Unification Theory or super-string theories that treat gravity and quantum mechanics in a consistent way, not only predict a dependence of fundamental physical constants with energy - particle physics experiments have shown the fine structure constant to grow to a value of about 1/128 at high collision energies - but allow for their cosmological time and space variations. A time dependence of the fundamental constants could also easily arise if, besides the three space dimensions, there exist more hidden dimensions. Already in 1955, the Russian physicist Lev Landau considered the possibility of a time dependence of alpha. In the late 1960s, George Gamow in the United States suggested that the charge of the electron, and therefore also alpha, may vary. It is clear however that such changes, if any, cannot be large or they would already have been detected in comparatively simple experiments. Tracking these possible changes thus requires the most sophisticated and precise techniques. Looking back in time In fact, quite strong constraints are already known to exist for the possible variation of the fine structure constant alpha. One such constraint is of geological nature. It is based on measures taken in the ancient natural fission reactor located near Oklo (Gabon, West Africa) and which was active roughly 2,000 million years ago. By studying the distribution of a given set of elements - isotopes of the rare earths, for example of samarium - which were produced by the fission of uranium, one can estimate whether the physical process happened at a faster or slower pace than we would expect it nowadays. Thus we can measure a possible change of the value of the fundamental constant at play here, alpha. However, the observed distribution of the elemen

2004-03-01

376

Louisiana Geological Survey  

NSDL National Science Digital Library

The Louisiana Geological Survey, located at Louisiana State University, developed this website to promote its goal to provide geological and environmental data that will allow for environmentally sound natural resource development and economic decisions. Users can find general information about the Survey's mission, staff, plan, and history. The website features the research and publications of the Basin Research, Cartographic, Coastal, Geologic Mapping, and Water and Environmental sections. Researchers can discover stratigraphic charts of Louisiana, information on lignite resources, and other geologic data.

377

South Carolina Geological Survey  

NSDL National Science Digital Library

The South Carolina Geological Survey (SCGS) homepage contains information about state mapping, education and outreach programs, and recent news. For educators, there is the Earth Science education series of publications which includes presentations and page-size graphics on such topics as earthquakes, plate tectonics, geologic time, fossils, and others. Other materials include information on mineral resources, links to organizations in and about South Carolina geology, the South Carolina core repository, the Geologic Map of South Carolina, and others.

378

Teaching Sedimentary Geology  

NSDL National Science Digital Library

This site contains a variety of resources for faculty members who teach undergraduate sedimentary geology. You will find links to a growing collection of activities and assignments, internet and computer resources, useful articles, presentations from the summer 2006 workshop on teaching sedimentary geology, and lots of creative ideas for teaching sedimentary geology.

379

Environmental geology in Australia  

Microsoft Academic Search

In Australia the concept of environmental geology is developing slowly from mainly engineering based activities to resource planning and utilization. This is particularly so with increasing activity in urban geology and in some States environmental geology influences land use and zoning. Since 1972 there have been clearly stated national policies in regard to the planned development of Australia's mineral and

G. M. Philip

1976-01-01

380

Geological Survey Program  

NSDL National Science Digital Library

If your research or interests lie in the geology of South Dakota, then the state's Geological Survey Program Web site is for you. Offered are online publications and maps, a geologic reference database, a lithologic logs database, digital base maps, a water quality database, and several other quality information sources worth checking out.

381

Unraveling Geological History: Glaciers and Faults at Discovery Park, Seattle  

NSDL National Science Digital Library

This introductory geology field exercise asks students to make individual observations about parts of an outcrop, then combine their observations in larger teams to interpret the overall geological history of the exposure. Content learning includes stratigraphy, faulting, and local geologic history; process learning includes data gathering and recording, hypothesis formation, and outlining helpful evidence that could be gathered in the future.

Trileigh Tucker

382

MAJOR TO CAREER GUIDE B.S. Geology  

E-print Network

MAJOR TO CAREER GUIDE B.S. Geology College of Sciences geoscience.unlv.edu/ Mission of the College: MPE-A 130 www.unlv.edu/sciences/advising About the Geology Career Geoscientists are stewards understanding of Earth processes and history. Value of the Geology Degree Opportunities for interesting

Walker, Lawrence R.

383

Inverse Modelling in Geology by Interactive Evolutionary Computation  

E-print Network

Inverse Modelling in Geology by Interactive Evolutionary Computation Chris Wijns a,b,, Fabio of geological processes, in the absence of established numerical criteria to act as inversion targets, requires evolutionary computation provides for the inclusion of qualitative geological expertise within a rigorous

Boschetti, Fabio

384

Co2 geological sequestration  

SciTech Connect

Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a geological formation can enhance the recovery of hydrocarbons, providing value-added byproducts that can offset the cost of CO{sub 2} capture and sequestration. Before CO{sub 2} gas can be sequestered from power plants and other point sources, it must be captured. CO{sub 2} is also routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H{sub 2} production, and limestone calcination. Then CO{sub 2} must be compressed into liquid form and transported to the geological sequestration site. Many power plants and other large emitters of CO{sub 2} are located near geological formations that are amenable to CO{sub 2} sequestration.

Xu, Tianfu

2004-11-18

385

Geologic Maps and Structures Name ______________________________ Geology 100 Harbor section  

E-print Network

Geologic Maps and Structures Name ______________________________ Geology 100 ­ Harbor section The objectives of this lab are for you to learn the basic geologic structures in 3-D and to develop some facility in interpreting the nature of geologic structures from geologic maps and geologic cross sections. A big part

Harbor, David

386

FUNDAMENTAL COMBUSTION RESEARCH APPLIED TO POLLUTION FORMATION. VOLUME 2A. PHYSICS AND CHEMISTRY OF TWO-PHASE SYSTEMS: FLAME COMBUSTION PROCESSES  

EPA Science Inventory

The reports included in the three-part volume describe eight studies by various investigators, to better understand the physics and chemistry of two-phase combustion with respect to pollution formation. Volume IIa describes mechanisms of fuel nitrogen processing in large-scale ut...

387

Phylogeographic patterns of genetic diversity in eastern Mediterranean water frogs have been determined by geological processes and climate change in the Late Cenozoic  

PubMed Central

Aim Our aims were to assess the phylogeographic patterns of genetic diversity in eastern Mediterranean water frogs and to estimate divergence times using different geological scenarios. We related divergence times to past geological events and discuss the relevance of our data for the systematics of eastern Mediterranean water frogs. Location The eastern Mediterranean region. Methods Genetic diversity and divergence were calculated using sequences of two protein-coding mitochondrial (mt) genes: ND2 (1038 bp, 119 sequences) and ND3 (340 bp, 612 sequences). Divergence times were estimated in a Bayesian framework under four geological scenarios representing alternative possible geological histories for the eastern Mediterranean. We then compared the different scenarios using Bayes factors and additional geological data. Results Extensive genetic diversity in mtDNA divides eastern Mediterranean water frogs into six main haplogroups (MHG). Three MHGs were identified on the Anatolian mainland; the most widespread MHG with the highest diversity is distributed from western Anatolia to the northern shore of the Caspian Sea, including the type locality of Pelophylax ridibundus. The other two Anatolian MHGs are restricted to south-eastern Turkey, occupying localities west and east of the Amanos mountain range. One of the remaining three MHGs is restricted to Cyprus; a second to the Levant; the third was found in the distribution area of European lake frogs (P. ridibundus group), including the Balkans. Main conclusions Based on geological evidence and estimates of genetic divergence we hypothesize that the water frogs of Cyprus have been isolated from the Anatolian mainland populations since the end of the Messinian salinity crisis (MSC), i.e. since c. 5.5-5.3 Ma, while our divergence time estimates indicate that the isolation of Crete from the mainland populations (Peloponnese, Anatolia) most likely pre-dates the MSC. The observed rates of divergence imply a time window of c. 1.6-1.1 million years for diversification of the largest Anatolian MHG; divergence between the two other Anatolian MHGs may have begun about 3.0 Ma, apparently as a result of uplift of the Amanos Mountains. Our mtDNA data suggest that the Anatolian water frogs and frogs from Cyprus represent several undescribed species. PMID:22473251

Ak?n, Çi?dem; Bilgin, C. Can; Beerli, Peter; Westaway, Rob; Ohst, Torsten; Litvinchuk, Spartak N.; Uzzell, Thomas; Bilgin, Metin; Hotz, Hansjürg; Guex, Gaston-Denis; Plötner, Jörg

2010-01-01

388

Significant achievements in the planetary geology program  

NASA Technical Reports Server (NTRS)

Recent developments in planetology research are summarized. Important developments are summarized in topics ranging from solar system evolution, comparative planetology, and geologic processes active on other planetary bodies, to techniques and instrument development for exploration.

Head, J. W. (editor)

1984-01-01

389

Introductory Geology From the Liberal Arts Approach: A Geology-Sociology Linked Course  

NASA Astrophysics Data System (ADS)

Geology can be a hard sell to college students, especially to college students attending small, liberal arts institutions in localities that lack exaggerated topography. At these schools, Geology departments that wish to grow must work diligently to attract students to the major; professors must be able to convince a wider audience of students that geology is relevant to their everyday lives. Toward this end, a Physical Geology course was linked with an introductory Sociology course through the common theme of Consumption. The same students took the two courses in sequence, beginning with the Sociology course and ending with Physical Geology; thus, students began by discussing the role of consumption in society and ended by learning about the geological processes and implications of consumption. Students were able to ascertain the importance of geology in their daily lives by connecting Earth processes to specific products they consume, such as cell phones and bottled water. Students were also able to see the connection between seemingly disparate fields of study, which is a major goal of the liberal arts. As a theme, Consumption worked well to grab the attention of students interested in diverse issues, such as environmental science or social justice. A one-hour lecture illustrating the link between sociology and geology was developed for presentation to incoming freshmen and their parents to advertise the course. Initial response has been positive, showing an increase in awareness of geological processes among students with a wide range of interests.

Walsh, E. O.; Davis, E.

2008-12-01

390

Geology and our future: summary of a workshop report  

SciTech Connect

This report highlights the significance of the geological sciences to the nation and to society. Discussions include understanding plate tectonics and surface processes, exploring the continental crust, ocean basins and the deep earth, applications of geology to social problems such as mineral resources, waste disposal, siting of critical facilities, geological hazards, water resources management, and coastal zones. The state of health of geological research is also discussed. (ACR)

Not Available

1983-01-01

391

A simple approach to 3D geological modelling and visualization  

Microsoft Academic Search

3D geological modeling has become one of the most reliable and effective means of displaying geological structures, but most\\u000a commercial software products for 3D geological modeling need special techniques and much pre-processing work as well as being\\u000a expensive and complicated to operate. In this paper, a simple approach to building a 3D geological model is proposed, integrating\\u000a such popular software

Wang Baojun; Shi Bin; Song Zhen

2009-01-01

392

Monte Carlo fundamentals  

SciTech Connect

This report is composed of the lecture notes from the first half of a 32-hour graduate-level course on Monte Carlo methods offered at KAPL. These notes, prepared by two of the principle developers of KAPL`s RACER Monte Carlo code, cover the fundamental theory, concepts, and practices for Monte Carlo analysis. In particular, a thorough grounding in the basic fundamentals of Monte Carlo methods is presented, including random number generation, random sampling, the Monte Carlo approach to solving transport problems, computational geometry, collision physics, tallies, and eigenvalue calculations. Furthermore, modern computational algorithms for vector and parallel approaches to Monte Carlo calculations are covered in detail, including fundamental parallel and vector concepts, the event-based algorithm, master/slave schemes, parallel scaling laws, and portability issues.

Brown, F.B.; Sutton, T.M.

1996-02-01

393

Evolution of U fractionation processes through geologic time : consequences for the variation of U deposit types from Early Earth to Present  

NASA Astrophysics Data System (ADS)

U deposits are known at nearly all stages of the geological cycle, but are not known prior to 2.95 Ga. Also, U deposit types vary greatly from Mesoarchean to Present. Most of these changes through time can be attributed to major modifications in the geodynamic evolution of the Earth, in magmatic fractionation processes, in the composition of the Atmosphere and in the nature of life. The first U-rich granites able to crystallize uraninite, appeared at about 3.1 Ga. They correspond to the most fractionated terms of high-K calcalkaline suites, resulting from crystal fractionation of magmas possibly derived from melting of mantle wedges enriched in K, U, Th. Highly fractionated peraluminous leucogranites, able to crystallize uraninite, appeared at about 2.6 Ga. Erosion of these two granite types led to the detrital accumulation of uraninite that formed the first U deposits on Earth: the Quartz Pebble Conglomerates from 2.95 to 2.4 Ga. From 2.3 Ga onwards, uprise of oxygen level in the atmosphere led to the oxidation of U(IV) to U(VI), U transport in solution, and exuberant development of marine algae in epicontinental platform sediments. From 2.3 to 1.8 Ga large amounts of U, previously accumulated as U(IV) minerals, were dissolved and trapped preferentially in passive margin settings, in organic-rich sediments, and which led to the formation of the world’s largest Paleoproterozoic U provinces, e.g. : the Wollaston belt, Canada and the Cahill Formation, Australia. During and after the worldwide 2.1-1.75 Ga orogenic events, responsible for the formation of the Nuna supercontinent, U trapped in these formations was the source for several types of mineralization: (i) metamorphosed U-mineralized graphitic schists, calcsilicates and meta-arkoses, (ii) diagenetic-hydrothermal remobilization with the formation of the first deposits related to redox processes at 2.0 Ga (Oklo, Gabon), (iii) partial melting of U-rich metasediments forming the uraninite disseminations in pegmatoids (Charlebois, Canada), (iv) hydrothermal remobilization in veins (Beaverlodge, Canada) at about 1.75 Ga, and (v) U mineralization related to Na-metasomatism (Lagoa Real, Brazil ; Central Ukraine). After 1.75 Ga, a long period of tectonic quiescence occurred on the Earth, and large intracontinental basins, comprising at their base thick oxidized siliciclastic sequences were formed in many parts of the Nuna. In the Athabasca (Canada) and Kombolgie (Australia) basins, the siliciclastic sediments represented huge aquitards for sodic brines derived from overlying evaporites. The brines became calcic when infiltrated into the basement and leached U dominantly from Paleoproterozoic epicontinental sediments, their anatectic derivatives and high-K-U granites, to form the unconformity related U deposits. By the end of Silurian, with the apparition of land plants, deposits hosted by continental to marginal marine sandstone (roll front, tabular, tectono-lithologic, paleovalleys) became widespread. The largest volcanic related U-deposits are mostly known during the Mesozoic and calcrete are only known during late Caenozoic to Quaternary, but this may by due to the non preservation from erosion of such deposits formed at very shallow levels.

Cuney, M.

2009-12-01

394

Streamflow and water-quality conditions including geologic sources and processes affecting selenium loading in the Toll Gate Creek watershed, Aurora, Arapahoe County, Colorado, 2007  

USGS Publications Warehouse

Toll Gate Creek is a perennial stream draining a suburban area in Aurora, Colorado, where selenium concentrations have consistently exceeded the State of Colorado aquatic-life standard for selenium of 4.6 micrograms per liter since the early 2000s. In cooperation with the City of Aurora, Colorado, Utilities Department, a synoptic water-quality study was performed along an 18-kilometer reach of Toll Gate Creek extending from downstream from Quincy Reservoir to the confluence with Sand Creek to develop a detailed understanding of streamflow and concentrations and loads of selenium in Toll Gate Creek. Streamflow and surface-water quality were characterized for summer low-flow conditions (July–August 2007) using four spatially overlapping synoptic-sampling subreaches. Mass-balance methods were applied to the synoptic-sampling and tracer-injection results to estimate streamflow and develop spatial profiles of concentration and load for selenium and other chemical constituents in Toll Gate Creek surface water. Concurrent groundwater sampling determined concentrations of selenium and other chemical constituents in groundwater in areas surrounding the Toll Gate Creek study reaches. Multivariate principal-component analysis was used to group samples and to suggest common sources for dissolved selenium and major ions. Hydrogen and oxygen stable-isotope ratios, groundwater-age interpretations, and chemical analysis of water-soluble paste extractions from core samples are presented, and interpretation of the hydrologic and geochemical data support conclusions regarding geologic sources of selenium and the processes affecting selenium loading in the Toll Gate Creek watershed. Streamflow conditions observed and measured during the synoptic water-quality study represent summer base-flow conditions and rainfall conditions for July 2007. The lack of large tributary inflows and the spatial distribution of small tributary inflows, seeps, and springs indicate that diffuse and discrete groundwater inflow supports streamflow during low-flow conditions along the entire 18-kilometer stream reach. Concentrations of dissolved selenium within all subreaches of Toll Gate Creek exceeded the Colorado aquatic-life standard of 4.6 micrograms per liter in 2007. Concentrations of selenium in the upper portion of the Toll Gate Headwaters subreach (TGH) remained close to the aquatic-life standard at about 5 micrograms per liter. Downstream from a concrete-lined channel section, inflows with selenium concentrations greater than the stream contribute selenium load to surface water. However, stream selenium concentrations were less than 20 micrograms per liter all along Toll Gate Creek. Concentrations of selenium in groundwater were in general substantially greater than the Colorado aquatic-life standard of 4.6 micrograms per liter and at some locations were greater than the U.S. Environmental Protection Agency primary drinking-water standard for selenium of 50 micrograms per liter. The distribution of selenium concentrations in groundwater, springs, and the 11 inflows with the greatest selenium concentrations indicates that shallow groundwater in surficial materials and the Denver Formation bedrock is a source of selenium loading to Toll Gate Creek and that selenium loading is distributed along the entire length of the study reach downstream from the concrete-lined channel. Water-quality and solids-sampling results from this study indicate weathering processes release water-soluble selenium from the underlying Denver Formation claystone bedrock with subsequent cycling of selenium in the aquatic environment of Toll Gate Creek. Exposure of the Denver Formation selenium-bearing bedrock to oxidizing atmospheric conditions, surface water, and groundwater, oxidizes selenide, held as a trace element in pyrite or in complexes with organic matter, to selenite and selenate. Secondary weathering products including iron oxides and selenium-bearing salts have accumulated in the weathered zone in the semiarid climate and also can serve as sources or sinks of selenium. P

Paschke, Suzanne S.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Schaffrath, Keelin R.

2013-01-01

395

Virtual-Geology.Info  

NSDL National Science Digital Library

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

396

Arkansas Geological Survey  

NSDL National Science Digital Library

The Arkansas Geological Survey (AGS) homepage aims to develop and provide knowledge of the geology and hydrogeology of the State, and to stimulate development and effective management and utilization of the mineral, fossil-fuel, and water resources of Arkansas while protecting the environment. The AGC collects and disperses geologic data consisting of geologic maps, historical data concerning resources, and various datasets concerning water, fossil-fuel, and mineral resources of Arkansas. The site contains publications that can be ordered, sections about Arkansas geology, a list of mineral producers of Arkansas, and reports on mineral resources.

397

Current status and future perspectives of electron interactions with molecules, clusters, surfaces, and interfaces [Workshop on Fundamental challenges in electron-driven chemistry; Workshop on Electron-driven processes: Scientific challenges and technological opportunities  

SciTech Connect

This report is based largely on presentations and discussions at two workshops and contributions from workshop participants. The workshop on Fundamental Challenges in Electron-Driven Chemistry was held in Berkeley, October 9-10, 1998, and addressed questions regarding theory, computation, and simulation. The workshop on Electron-Driven Processes: Scientific Challenges and Technological Opportunities was held at Stevens Institute of Technology, March 16-17, 2000, and focused largely on experiments. Electron-molecule and electron-atom collisions initiate and drive almost all the relevant chemical processes associated with radiation chemistry, environmental chemistry, stability of waste repositories, plasma-enhanced chemical vapor deposition, plasma processing of materials for microelectronic devices and other applications, and novel light sources for research purposes (e.g. excimer lamps in the extreme ultraviolet) and in everyday lighting applications. The life sciences are a rapidly advancing field where the important role of electron-driven processes is only now beginning to be recognized. Many of the applications of electron-initiated chemical processes require results in the near term. A large-scale, multidisciplinary and collaborative effort should be mounted to solve these problems in a timely way so that their solution will have the needed impact on the urgent questions of understanding the physico-chemical processes initiated and driven by electron interactions.

Becker, Kurt H.; McCurdy, C. William; Orlando, Thomas M.; Rescigno, Thomas N.

2000-09-01

398

Fundamentals of fluid lubrication  

NASA Technical Reports Server (NTRS)

The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.

Hamrock, Bernard J.

1991-01-01

399

Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California: Chapter G in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California  

USGS Publications Warehouse

From December 2010 to January 2011, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of Leach Lake Basin within the National Training Center, Fort Irwin, California. These data were collected to characterize the subsurface and provide information needed to understand and manage groundwater resources within Fort Irwin. A resistivity stratigraphy was developed using ground-based time-domain electromagnetic soundings together with laboratory resistivity measurements on hand samples and borehole geophysical logs from nearby basins. This report releases data associated with the airborne surveys, as well as resistivity cross-sections and depth slices derived from inversion of the airborne electromagnetic data. The resulting resistivity models confirm and add to the geologic framework, constrain the hydrostratigraphy and the depth to basement, and reveal the distribution of faults and folds within the basin.

Bedrosian, Paul A.; Ball, Lyndsay B.; Bloss, Benjamin R.

2014-01-01

400

Fundamental Plane Rotation and shapes  

E-print Network

Contents Fundamental Plane Rotation and shapes Central kinematics and black holes Dynamical models Astronomical Institute Dynamics of elliptical galaxies #12;Contents Fundamental Plane Rotation and shapes Central kinematics and black holes Dynamical models and dark matter Contents Fundamental Plane Rotation

Kruit, Piet van der

401

Kansas Geological Survey  

NSDL National Science Digital Library

The mission of the Kansas Geological Survey, operated by the University of Kansas in connection with its research and service program, is to conduct geological studies and research and to collect, correlate, preserve, and disseminate information leading to a better understanding of the geology of Kansas, with special emphasis on natural resources of economic value, water quality and quantity, and geologic hazards. The website includes information about the High Plains and Ogallala aquifers, the Upper Arkansas corridor, the Dakota aquifer, county and state geologic maps, an online bibliography of Kansas geology, publications, a photo archive, a digital petroleum atlas, a petroleum primer for the state, gravity and magnetic maps, Hugoton project information, and details about the Hutchinson Kansas natural gas fires. The educational resources section contains a mineral information page for the state, and GeoKansas, which provides information on state geology for schools.

402

Fundamentals of Carrier Transport  

Microsoft Academic Search

Fundamentals of Carrier Transport explores the behavior of charged carriers in semiconductors and semiconductor devices for readers without an extensive background in quantum mechanics and solid-state physics. This second edition contains many new and updated sections, including a completely new chapter on transport in ultrasmall devices and coverage of \\

Mark Lundstrom

2000-01-01

403

PSYCHOLOGY FUNDAMENTALS Course Syllabus  

E-print Network

PSYCHOLOGY FUNDAMENTALS Course Syllabus Fall, 2007 Course: Psych 9A; Psy Beh 11A Lecture: TuTh 2:00­3:20 Code: 68040 Room: PSLH 100 TEXT: Gleitman, Psychology, 7th Edition PROFESSOR: Don Hoffman SECRETARY at http://www.cogsci.uci.edu/ddhoff/HoffmanPubs.html or his book Visual Intelligence (Norton Press, 2000

Stanford, Kyle

404

PSYCHOLOGY FUNDAMENTALS Course Syllabus  

E-print Network

1 PSYCHOLOGY FUNDAMENTALS Course Syllabus Fall, 2014 Course: Psych 9A/Psy Beh 11A Lecture: TuTh 12:30-1:50 Code: 68030/54030 Room: PSLH 100 TEXT: Gleitman, Psychology, 8th Edition PROFESSOR: Don Hoffman's research, you can see his webpage, his publications, his book Visual Intelligence, his paper

Stanford, Kyle

405

Fundamentals of Diesel Engines.  

ERIC Educational Resources Information Center

This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the fundamentals of diesel engine mechanics. Addressed in the three individual units of the course are the following topics: basic principles of diesel mechanics; principles, mechanics, and…

Marine Corps Inst., Washington, DC.

406

Fundamentals of Raman spectroscopy  

E-print Network

-29 m2 Non-resonant Raman spectroscopy: 10-33 m2 Surface Enhanced Raman Scattering: 10-? m2 Surface" non-resonant and resonant Raman cross sections. So: Surface Enhanced Raman Scattering: 10-21 to 1013112012 1 Fundamentals of Raman spectroscopy Part1 Cees Otto Vibrational Spectroscopy IR

Twente, Universiteit

407

Homeschooling and Religious Fundamentalism  

ERIC Educational Resources Information Center

This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to…

Kunzman, Robert

2010-01-01

408

Spectral Analysis Fundamentals  

NSDL National Science Digital Library

This tutorial is part of the National Instruments Measurement Fundamentals series. Each tutorial in this series will teach a specific topic of common measurement applications, by explaining the theory and giving practical examples. This tutorial covers an introduction to RF, wireless and high-frequency signals and systems. A PDF of the lesson is also available.

409

Fundamentals of Geophysics  

Microsoft Academic Search

This unique textbook presents a comprehensive overview of the fundamental principles of geophysics. Unlike most geophysics textbooks, it combines both the applied and theoretical aspects to the subject. The author explains complex geophysical concepts using abundant diagrams, a simplified mathematical treatment, and easy-to-follow equations. After placing the Earth in the context of the solar system, he describes each major branch

William Lowrie; Ola M. Saether; A. A. Balkema; GEO ENV; Ian Lerche; M. C. R. Davies; M. Armstrong

1997-01-01

410

Fundamentals of soil science  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study guide provides comments and references for professional soil scientists who are studying for the soil science fundamentals exam needed as the first step for certification. The performance objectives were determined by the Soil Science Society of America's Council of Soil Science Examiners...

411

Food Service Fundamentals.  

ERIC Educational Resources Information Center

Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on food service fundamentals is designed to provide a general background in the basic aspects of the food service program in the Marine Corps; it is adaptable for nonmilitary instruction. Introductory materials include specific information for MCI…

Marine Corps Inst., Washington, DC.

412

DNA Topology: Fundamentals  

E-print Network

DNA Topology: Fundamentals Sergei M Mirkin, University of Illinois at Chicago, Illinois, USA Topological characteristics of DNA and specifically DNA supercoiling influence all major DNA transactions in living cells. DNA supercoiling induces the formation of unusual secondary structure by specific DNA

Mirkin, Sergei

413

FUNDAMENTAL SOURCES OF UNPREDICTABILITY  

Microsoft Academic Search

Abstract: Of course, spontaneous symmetry breaking may give riseto some parameters and even to a choice of solutions, withprobabilities for the various alternatives. I shall deal with thatpossibility further on.)This second assumption is equivalent to stating that there is nonecessary fundamental unpredictability stemming from ignorance of theuniversal dynamical law.3) The density matrix (in the Schrsdinger picture) of the universenear the

Murray Gell-Mann

1996-01-01

414

Fundamentals of solar cells  

Microsoft Academic Search

This text is addressed to upper level graduate students with background in solid state physics and to scientists and engineers involved in solar cell research. The author aims to present fundamental physical principles rather than the state-of-the-art. Specific devices are used to illustrate basic phenomena and to indicate possibilities for innovative design. Contents, abridged: Solar insolation. The calculation of solar

A. L. Farhenbruch; R. H. Bube

1983-01-01

415

Fundamentals of air pollution  

Microsoft Academic Search

Fundamentals of Air Pollution, Second Edition, a textbook for undergraduate and graduate level courses in air pollution, covers elements, sources, effects, measurement, monitoring, meteorology, and regulatory and engineering control of air pollution. Existing knowledge of these topics are reviewed and the book is updated to include acidic deposition, long-distance transport, atmospheric chemistry, and mathematical modeling. The authors discuss current air

A. C. Stern; R. W. Boubel; D. L. Fox; B. Turner

1984-01-01

416

Fundamentals of Soil Nutrient  

E-print Network

­ soluble! · Cycles readily through organic matter #12;Sulfur Inputs compared to Tree UptakeSulfur InputsFundamentals of Soil Nutrient Dynamics Steven Perakis #12;N2 P, S, Ca, Mg, K, Mo, Fe, ...... #12;Nutritional Issues at NitrogenNutritional Issues at Nitrogen--Rich SitesRich Sites · Phosphorus · Sulfur

417

FUNDAMENTALS MOVEMENT PERCEPTION  

E-print Network

FUNDAMENTALS OF THE THEORY OF MOVEMENT PERCEPTION BY DR. ERNST MACH Translated and Annotated to the Translated Edition The value of this publication of Ernst Mach's work of 1875 on movement perception lies, which would have delighted Mach. But the book also illuminates the kind of scientist-philosopher Mach

Scherberger, Hansjörg

418

Fundamental Radiation Concepts  

E-print Network

Fundamental Radiation Concepts Alyson Cieply University of Florida Environmental Health and Safety Radiation Control #12;What is radiation? Radiation is energy that travels through space or matter in the form of a particle or wave The effect radiation has on matter depends on the type of radiation and how

Slatton, Clint

419

Fundamentals of Library Instruction  

ERIC Educational Resources Information Center

Being a great teacher is part and parcel of being a great librarian. In this book, veteran instruction services librarian McAdoo lays out the fundamentals of the discipline in easily accessible language. Succinctly covering the topic from top to bottom, he: (1) Offers an overview of the historical context of library instruction, drawing on recent…

McAdoo, Monty L.

2012-01-01

420

Laser Fundamentals and Experiments.  

ERIC Educational Resources Information Center

As a result of work performed at the Southwestern Radiological Health Laboratory with respect to lasers, this manual was prepared in response to the increasing use of lasers in high schools and colleges. It is directed primarily toward the high school instructor who may use the text for a short course in laser fundamentals. The definition of the…

Van Pelt, W. F.; And Others

421

Fundamental Materials Research and Advanced Process Development for Thin-Film CIS-Based Photovoltaics: Final Technical Report, 2 October 2001 - 30 September 2005  

SciTech Connect

The objectives for this thin-film copper-indium-diselenide (CIS) solar cell project cover the following areas: Develop and characterize buffer layers for CIS-based solar cell; grow and characterize chemical-bath deposition of Znx Cd1-xS buffer layers grown on CIGS absorbers; study effects of buffer-layer processing on CIGS thin films characterized by the dual-beam optical modulation technique; grow epitaxial CuInSe2 at high temperature; study the defect structure of CGS by photoluminescence spectroscopy; investigate deep-level defects in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy; conduct thermodynamic modeling of the isothermal 500 C section of the Cu-In-Se system using a defect model; form alpha-CuInSe2 by rapid thermal processing of a stacked binary compound bilayer; investigate pulsed non-melt laser annealing on the film properties and performance of Cu(In,Ga)Se2 solar cells; and conduct device modeling and simulation of CIGS solar cells.

Anderson, T. J.; Li, S. S.; Crisalle, O. D.; Craciun, V.

2006-09-01

422

Name of the Presentation Fundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic Radiation  

E-print Network

4/9/2004 1 Name of the Presentation Fundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic Radiation Energy is the ability to do work. In the process of doing work by electromagnetic radiation is of primary interest to remote sensing because it is the only form of energy transfer

423

Map Showing Geology, Oil and Gas Fields and Geologic Provinces of Africa, Ver. 2.0  

NSDL National Science Digital Library

The US Geological Survey offers the Map Showing Geology, Oil and Gas Fields and Geologic Provinces of Africa Web site and report. The agency's goal for the pieces includes assessing the undiscovered and technically recoverable oil and gas resources of the world. The site includes various descriptions of what the map depicts and how data was processed using Geographic Information Systems. Once the interactive map is activated, users can search and click the map of Africa to view geologic provinces, oil and gas fields, as well as the various surface geological classifications. Although the interface is a bit cumbersome and works best with a fast Internet connection, the unique information provided should draw the attention of those interested in geology. [JAB

Ahlbrandt, Thomas S.

424

Sand Resources, Regional Geology, and Coastal Processes of the Chandeleur Islands Coastal System: an Evaluation of the Breton National Wildlife Refuge  

USGS Publications Warehouse

Breton National Wildlife Refuge, the Chandeleur Islands chain in Louisiana, provides habitat and nesting areas for wildlife and is an initial barrier protecting New Orleans from storms. The U.S. Geological Survey (USGS) in partnership with the University of New Orleans Pontchartrain Institute for Environmental Sciences undertook an intensive study that included (1) an analysis of island change based on historical maps and remotely sensed shoreline and topographic data; (2) a series of lidar surveys at 3- to 4-month intervals after Hurricane Katrina to determine barrier island recovery potential; (3) a discussion of sea level rise and effects on the islands; (4) an analysis of sea floor evolution and sediment dynamics in the refuge over the past 150 years; (5) an assessment of the local sediment transport and sediment resource availability based on the bathymetric and subbottom data; (6) a carefully selected core collection effort to groundtruth the geophysical data and more fully characterize the sediments composing the islands and surrounds; (7) an additional survey of the St. Bernard Shoals to assess their potential as a sand resource; and (8) a modeling study to numerically simulate the potential response of the islands to the low-intensity, intermediate, and extreme events likely to affect the refuge over the next 50 years. Results indicate that the islands have become fragmented and greatly diminished in subaerial extent over time: the southern islands retreating landward as they reorganize into subaerial features, the northern islands remaining in place. Breton Island, because maintenance of the Mississippi River-Gulf Outlet (MRGO) outer bar channel requires dredging, is deprived of sand sufficient to sustain itself. Regional sediment transport trends indicate that large storms are extremely effective in transporting sand and controlling the shoreline development and barrier island geometry. Sand is transported north and south from a divergent zone near Monkey Bayou at the southern end of the Chandeleur Islands. Numerical simulation of waves and sediment transport supports the geophysical results and indicates that vast areas of the lower shoreface are affected and are undergoing erosion during storm events, that there is little or no fair weather mechanism to rework material into the littoral system, and that as a result, there is a net loss of sediment from the system. Lidar surveys revealed that the island chain immediately after Hurricane Katrina lost about 84 percent of its area and about 92 percent of its prestorm volume. Marsh platforms that supported the islands' sand prior to the storm were reduced in width by more than one-half. Repeated lidar surveys document that in places the shoreline has retreated about 100 m under the relatively low-energy waves since Hurricanes Katrina and Rita; however, this retreat is nonuniform. Recent high-resolution geophysical surveys of the sea floor and subsurface within 5-6 km of the Chandeleur Islands during 2006 and 2007 show that, in addition to the sand that is rebuilding portions of the island chain, a large volume of sand is contained in Hewes Point, in an extensive subtidal spit platform that has formed at the northern end of the Chandeleur Islands. Hewes Point appears to be the depositional terminus of the alongshore transport system. In the southern Chandeleurs, sand is being deposited in a broad tabular deposit near Breton Island called the southern offshore sand sheet. These two depocenters account for approximately 70 percent of the estimated sediment volume located in potential borrow sites. An additional large potential source of sand for restoration lies in the St. Bernard Shoals, which are estimated to contain approximately 200 ? 106 m3 of sand. Successful restoration planning for the Breton National Wildlife Refuge should mimic the natural processes of early stages of barrier island evolution including lateral transport to the flanks of the island chain

2009-01-01

425

40 CFR 403.13 - Variances from categorical pretreatment standards for fundamentally different factors.  

Code of Federal Regulations, 2010 CFR

...quality environmental impact (including energy requirements) fundamentally...quality environmental impact (including energy requirements) fundamentally...raw waste load of the User's process wastewater: (2) The...

2010-07-01

426

Significant achievements in the Planetary Geology Program, 1981  

SciTech Connect

Recent developments in planetology research as reported at the 1981 NASA Planetary Geology Principal Investigators meeting are summarized. The evolution of the solar system, comparative planetology, and geologic processes active on other planets are considered. Galilean satellites and small bodies, Venus, geochemistry and regoliths, volcanic and aeolian processes and landforms, fluvial and periglacial processes, and planetary impact cratering, remote sensing, and cartography are discussed.

Holt, H.E.

1981-09-01

427

CO{sub 2} Geologic Storage: Coupled Hydro-Chemo-Thermo-Mechanical Phenomena - From Pore-scale Processes to Macroscale Implications -  

SciTech Connect

Global energy consumption will increase in the next decades and it is expected to largely rely on fossil fuels. The use of fossil fuels is intimately related to CO{sub 2} emissions and the potential for global warming. Geological CO{sub 2} storage aims to mitigate the global warming problem by sequestering CO{sub 2} underground. Coupled hydro-chemo-mechanical phenomena determine the successful operation and long term stability of CO{sub 2} geological storage. This research explores coupled phenomena, identifies different zones in the storage reservoir, and investigates their implications in CO{sub 2} geological storage. In particular, the research: Explores spatial patterns in mineral dissolution and precipitation (comprehensive mass balance formulation); experimentally determines the interfacial properties of water, mineral, and CO{sub 2} systems (including CO{sub 2}-water-surfactant mixtures to reduce the CO{sub 2}- water interfacial tension in view of enhanced sweep efficiency); analyzes the interaction between clay particles and CO{sub 2}, and the response of sediment layers to the presence of CO{sub 2} using specially designed experimental setups and complementary analyses; couples advective and diffusive mass transport of species, together with mineral dissolution to explore pore changes during advection of CO{sub 2}-dissolved water along a rock fracture; upscales results to a porous medium using pore network simulations; measures CO{sub 2} breakthrough in highly compacted fine-grained sediments, shale and cement specimens; explores sealing strategies; and experimentally measures CO{sub 2}-CH{sub 4} replacement in hydrate-bearing sediments during. Analytical, experimental and numerical results obtained in this study can be used to identify optimal CO{sub 2} injection and reservoir-healing strategies to maximize the efficiency of CO{sub 2} injection and to attain long-term storage.