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1

Fundamentals of Structural Geology  

NASA Astrophysics Data System (ADS)

Fundamentals of Structural Geology provides a new framework for the investigation of geological structures by integrating field mapping and mechanical analysis. Assuming a basic knowledge of physical geology, introductory calculus and physics, it emphasizes the observational data, modern mapping technology, principles of continuum mechanics, and the mathematical and computational skills, necessary to quantitatively map, describe, model, and explain deformation in Earth's lithosphere. By starting from the fundamental conservation laws of mass and momentum, the constitutive laws of material behavior, and the kinematic relationships for strain and rate of deformation, the authors demonstrate the relevance of solid and fluid mechanics to structural geology. This book offers a modern quantitative approach to structural geology for advanced students and researchers in structural geology and tectonics. It is supported by a website hosting images from the book, additional colour images, student exercises and MATLAB scripts. Solutions to the exercises are available to instructors. The book integrates field mapping using modern technology with the analysis of structures based on a complete mechanics MATLAB is used to visualize physical fields and analytical results and MATLAB scripts can be downloaded from the website to recreate textbook graphics and enable students to explore their choice of parameters and boundary conditions The supplementary website hosts color images of outcrop photographs used in the text, supplementary color images, and images of textbook figures for classroom presentations The textbook website also includes student exercises designed to instill the fundamental relationships, and to encourage the visualization of the evolution of geological structures; solutions are available to instructors

Pollard, David D.; Fletcher, Raymond C.

2005-09-01

2

Fundamentals of Structural Geology  

NSDL National Science Digital Library

Fundamentals of Structural Geology is a textbook that emphasizes modern techniques of field data acquisition and analysis, the principles of continuum mechanics, and the mathematical and computational skills necessary to quantitatively describe, model, and explain the deformation of rock in Earth's lithosphere. This site provides an online interface for the book with supplementary materials for readers, instructors, and students. Resources include color photographs of outcrops, textbook figures, and supplementary illustrations for classroom presentations; student exercises to develop Matlab skills; Matlab scripts to make textbook figures dynamic, introduction to the concepts of differential geometry, mechanical models, and the evolution of geologic structures; and research quality data sets and solutions for instructors. The site also includes book information and links to additional resources.

Pollard, David; Fletcher, Raymond; University, Stanford

3

Sea Level Change, A Fundamental Process When Interpreting Coastal Geology and Geography.  

ERIC Educational Resources Information Center

Discusses the meaning of sea level change and identifies the major factors responsible for this occurrence. Elaborates on the theory and processes involved in indirect measurement of changes in sea volume. Also explains how crustal movement affects sea level. (ML)

Zeigler, John M.

1985-01-01

4

(Fundamentals of materials processing)  

SciTech Connect

The traveler attended the Indo-US Workshop on Fundamentals of Materials Processing and presented an invited paper entitled Microstructural Modifications During Laser Welding.'' The workshop was organized by the US Office of Naval Research in collaboration with the Department of Science and Technology, India. The traveler was part of the US delegation comprised of world-renowned scientists representing the US Navy, National Science Foundation, National Bureau of Standards, and US universities. The Workshop program continued several papers on topics relating to mathematical modeling of melting and solidification processes, continuous casting, laser, and plasma processing of materials. The traveler also attended a one-day Indo-US Workshop on Welding Science. Funds for the travel were provided by the US Navy through the Special Foreign Currency Program.

David, S.A.

1988-02-02

5

Geological processes and evolution  

USGS Publications Warehouse

Geological mapping and establishment of stratigraphic relationships provides an overview of geological processes operating on Mars and how they have varied in time and space. Impact craters and basins shaped the crust in earliest history and as their importance declined, evidence of extensive regional volcanism emerged during the Late Noachian. Regional volcanism characterized the Early Hesperian and subsequent to that time, volcanism was largely centered at Tharsis and Elysium, continuing until the recent geological past. The Tharsis region appears to have been largely constructed by the Late Noachian, and represents a series of tectonic and volcanic centers. Globally distributed structural features representing contraction characterize the middle Hesperian. Water-related processes involve the formation of valley networks in the Late Noachian and into the Hesperian, an ice sheet at the south pole in the middle Hesperian, and outflow channels and possible standing bodies of water in the northern lowlands in the Late Hesperian and into the Amazonian. A significant part of the present water budget occurs in the present geologically young polar layered terrains. In order to establish more firmly rates of processes, we stress the need to improve the calibration of the absolute timescale, which today is based on crater count systems with substantial uncertainties, along with a sampling of rocks of unknown provenance. Sample return from carefully chosen stratigraphic units could calibrate the existing timescale and vastly improve our knowledge of Martian evolution.

Head, J. W.; Greeley, R.; Golombek, M. P.; Hartmann, W. K.; Hauber, E.; Jaumann, R.; Masson, P.; Neukum, G.; Nyquist, L. E.; Carr, M. H.

2001-01-01

6

Fundamental Elements of Geologic C02 Sequestration in Saline Aquifers  

SciTech Connect

Geologic sequestration represents a promising strategy for isolating CO{sub 2} waste streams from the atmosphere. Successful implementation of this approach hinges on our ability to predict the relative effectiveness of subsurface CO{sub 2} migration and sequestration as a function of key target-formation and cap-rock properties, which will enable us to identify optimal sites and evaluate their long-term isolation performance. Quantifying this functional relationship requires a modeling capability that explicitly couples multiphase flow and kinetically controlled geochemical processes. We have developed a unique computational package that meets these criteria, and used it to model CO{sub 2} injection at Statoil's North-Sea Sleipner facility, the world's first saline-aquifer storage site. The package integrates a state-of-the-art reactive transport simulator (NUFT) with supporting geochemical software and databases (SUPCRT92). In our Sleipner study, we have quantified--for the first time--the influence of intra-aquifer shales and aquifer/cap-rock composition on migration/sequestration balance, sequestration partitioning among hydrodynamic, solubility, and mineral trapping mechanisms, and the isolation performance of shale cap rocks. Here, we review the fundamental elements of geologic CO{sub 2} sequestration in saline aquifers as revealed from model XSH of our Sleipner study; this model, unlike CSH and DSH, does not address the complicating (yet advantageous) presence of intra-aquifer shales.

Johnson, J W; Nitao, J J; Steefel, C I

2001-11-19

7

Fundamentals of Microelectronics Processing (VLSI).  

ERIC Educational Resources Information Center

Describes a 15-week course in the fundamentals of microelectronics processing in chemical engineering, which emphasizes the use of very large scale integration (VLSI). Provides a listing of the topics covered in the course outline, along with a sample of some of the final projects done by students. (TW)

Takoudis, Christos G.

1987-01-01

8

Coastal Processes and Offshore Geology  

Microsoft Academic Search

The modern coastal geology of Virginia results from the interactions of modern processes, primarily waves, tidal currents and sea-level rise, with the antecedent geology. The ancient and major rivers draining the Piedmont and interior highlands of eastern North America carried sediments that were deposited in various areas across the physiographic continuum of the coastal plain and continental shelf as sea

Carl H. Hobbs; David E. Krantz; Geoffrey L. Wikel

9

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.

2011-02-03

10

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.

11

Prediction of Exogenic Geological Processes  

Microsoft Academic Search

Prediction of exogenic geological processes (EGP) involves scientifically substantiated forecasting of events in space and\\u000a time under the action of natural and anthropogenically induced factors. The goal of the EGP prediction is to give the answers\\u000a to the three basic questions — where, when and of which activity (size) one or another type of exogenic geological process\\u000a can happen, and

Arkady Sheko; Vladimir Krupoderov

12

Fundamentals Of Biomedical Image Processing  

Microsoft Academic Search

Automatic biomedical image processing has enjoyed increased popularity of late, primarily because it can be used to enhance images to measure and count accurately and quickly in various types of applications. Preliminary background and basic terminology commonly used in biomedical image processing will be reviewed. Among these are sources and forms of biomedical images , image enhancement, searching and analysis

H. K. Huang; N. W. Washington

1978-01-01

13

Fundamental issues in the geology and geophysics of Venus  

NASA Astrophysics Data System (ADS)

A number of important and currently unresolved issues in the global geology and geophysics of Venus will be addressable with the radar imaging, altimetry, and gravity measurements now forthcoming from the Magellan mission. Among these are the global volcanic flux and the rate of formation of new crust; the global heat flux and its regional variations; the relative importance of localized hot spots and linear centers of crustal spreading to crustal formation and tectonics; and the planform of mantle convection on Venus and the nature of the interactions among interior convective flow, near-surface deformation, and magmatism.

Solomon, S. C.; Head, J. W.

1991-04-01

14

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

15

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

16

Impact process: an important geological phenomenon.  

PubMed

The impact process was for a long period of time, even after a wider acceptance among the geological community, considered to be a marginal phenomenon in the Earth sciences. The first decade or two have showed an importance of the process itself and consequent events only too clearly. The present paper is a review describing the history and development of the impact hypothesis, structure and origin of impact craters, influence of huge impacts on the living environment and other aspects of the impact process from the point of view of geology s.l. PMID:11541230

Skala, R

1996-01-01

17

Deterministic geologic processes and stochastic modeling  

SciTech Connect

Recent outcrop sampling at Yucca Mountain, Nevada, has produced significant new information regarding the distribution of physical properties at the site of a potential high-level nuclear waste repository. Consideration of the spatial distribution of measured values and geostatistical measures of spatial variability indicates that there are a number of widespread deterministic geologic features at the site that have important implications for numerical modeling of such performance aspects as ground water flow and radionuclide transport. These deterministic features have their origin in the complex, yet logical, interplay of a number of deterministic geologic processes, including magmatic evolution; volcanic eruption, transport, and emplacement; post-emplacement cooling and alteration; and late-stage (diagenetic) alteration. Because of geologic processes responsible for formation of Yucca Mountain are relatively well understood and operate on a more-or-less regional scale, understanding of these processes can be used in modeling the physical properties and performance of the site. Information reflecting these deterministic geologic processes may be incorporated into the modeling program explicitly, using geostatistical concepts such as soft information, or implicitly, through the adoption of a particular approach to modeling. It is unlikely that any single representation of physical properties at the site will be suitable for all modeling purposes. Instead, the same underlying physical reality will need to be described many times, each in a manner conducive to assessing specific performance issues.

Rautman, C.A. [Sandia National Labs., Albuquerque, NM (United States); Flint, A.L. [Geological Survey, Mercury, NV (United States)

1991-12-31

18

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

19

Fundamental processes in laser drilling and welding  

NASA Astrophysics Data System (ADS)

Laser penetration processing of a variety of transparent and translucent dielectrics was carried out under varying gravitational levels. Real time differential holographic interferometry was used to measure heat transfer in laser drilling of fused quartz in zero and normal gravity. Measurements were compared with a numerical model based on a prolate spherical coordinate frame. The model agrees well with experiments close to the surface, but overestimates the extent of the heat transport deeper into the quartz. Modulated beam intensity drilling of liquids is studied. Frequency dependent structures are observed, particularly in glycerol drilling which exhibit transitions to extremely stable resonant states. A potential mechanism for this resonance is presented. Laser drill hole initiation in glycerol and acrylic is studied. A parametric energy conservation model is developed and found to be well suited as a laser beam intensity diagnostic. CW Laser drilling of glycerol-water mixtures and gelatin is studied and dynamical behaviour is discussed in terms of material property differences in viscosity and environmental factors associated with gravity.

Olfert, Mark Randall

20

Prevention Education Effects on Fundamental Memory Processes  

PubMed Central

This study evaluated effects of a key session from a nationally recognized drug abuse prevention program on basic memory processes in 211 high-risk youth in Southern California. In a randomized, between-subject design, the authors manipulated assignment to a Myth and Denial program session and the time of assessment (immediate vs. one-week delay). The authors examined program decay effects on memory accessibility and judgment errors. Those participants exposed to the program session generated more myths and facts from the program than those in the control group, suggesting that even a single program session influenced students’ memory for program information and this was retained at least one week and detectable with indirect tests of memory accessibility. However, consistent with basic research perspectives, participants in the program delayed assessment group erroneously generated more fact-related information from the session to the prompt “It is a myth that_____” than the participants in the program immediate assessment group; that is, they retained more facts as myths. These types of program effects, anticipated by basic memory theory, were not detected with a traditional judgment task in the present sample. The results suggest that basic science approaches offer a novel way of conceptually recasting prevention effects to more completely understand how these effects may operate. Implications for program evaluation and conceptualization are discussed.

Ames, Susan L.; Krank, Marvin; Grenard, Jerry L.; Sussman, Steve; Stacy, Alan W.

2014-01-01

21

Deterministic geologic processes and stochastic modeling  

Microsoft Academic Search

Recent outcrop sampling at Yucca Mountain, Nevada, has produced significant new information regarding the distribution of physical properties at the site of a potential high-level nuclear waste repository. Consideration of the spatial distribution of measured values and geostatistical measures of spatial variability indicates that there are a number of widespread deterministic geologic features at the site that have important implications

C. A. Rautman; A. L. Flint

1991-01-01

22

Business process simulation: a fundamental step supporting process centered management  

Microsoft Academic Search

Business processes are increasingly recognised as the key to competitive survival. The important opportunities inherent to this invisible economic asset are the foundations of process centred management. Simulation of business processes creates added value in understanding, analysing, and designing processes by introducing dynamic aspects. It provides decision support by anticipation of future changes in process design and improves understanding of

Marc Aguilar; Tankred Rautert; Alexander J. G. Pater

1999-01-01

23

Geologic process studies using Synthetic Aperture Radar (SAR) data  

NASA Technical Reports Server (NTRS)

The use of SAR data to study geologic processes for better understanding of recent tectonic activity and climate change as well as the mitigation of geologic hazards and exploration for nonrenewable resources is discussed. The geologic processes that are particularly amenable to SAR-based data include volcanism; soil erosion, degradation, and redistribution; coastal erosion and inundation; glacier fluctuations; permafrost; and crustal motions. When SAR data are combined with data from other planned spaceborne sensors including ESA ERS, the Japanese Earth Resources Satellite, and the Canadian Radarsat, it will be possible to build a time-series view of temporal changes over many regions of earth.

Evans, Diane L.

1992-01-01

24

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...

25

Fundamentals of beam-solid interactions and transient thermal processing  

SciTech Connect

This book contains papers presented at the Materials Research Society symposium on Fundamentals of Beam-Solid Interactions and Transient Processing. This symposium was devoted to fundamental aspects of the interactions of photon, ion, and electron beams with solids and to beam-induced phase transformations in materials. The material covered in this symposium focused on two distinct asreas. The first was phase transformations induced by ion or electron bombardment, including amorphization and interface motion. The second was the behavior of solids during various forms of annealing and quenching ranging in duration from femtoseconds to hours.

Aziz, M.J. (Harvard Univ., Cambridge, MA (US)); Rehn, L.E. (Argonne, IL (US)); Stritzker, B. (Kernforschungsanglage, Julich (DE))

1988-01-01

26

Fundamental processes in the evolutionary ecology of Lyme borreliosis  

Microsoft Academic Search

The evolutionary ecology of many emerging infectious diseases, particularly vector-borne zoonoses, is poorly understood. Here, we aim to develop a biological, process-based framework for vector-borne zoonoses, using Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis in humans, as an example. We explore the fundamental biological processes that operate in this zoonosis and put forward hypotheses on how

Klára Hanincová; Jean I. Tsao; Gabriele Margos; Durland Fish; Nicholas H. Ogden; Klaus Kurtenbach

2006-01-01

27

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

28

Fundamental Issues in Hydroforming of Deep Drawing Processes  

NASA Astrophysics Data System (ADS)

The wide spectrum of recent improvements in hydroforming deep drawing processes is descried here briefly. New accomplishments were seemingly achieved as soon as the sheet forming industry has found their cost-effectiveness. Some fundamental results and their physical motives are presented, based on an idealized limit-analysis formulation (lower bound approach in this case). The mathematical complexities frequently encountered in more precise solutions are thus avoided, though they had been established as (partially) appeared in the reference list.

Tirosh, Jehuda

2005-08-01

29

Exogenic Geological Processes As a Landform-Shaping Factor  

Microsoft Academic Search

Exogenic processes include geological phenomena and processes that originate externally to the Earth’s surface. They are genetically\\u000a related to the atmosphere, hydrosphere and biosphere, and therefore to processes of weathering, erosion, transportation, deposition,\\u000a denudation etc. Exogenic factors and processes could also have sources outside the Earth, for instance under the influence\\u000a of the Sun, Moon etc. The above mentioned processes

Marek Graniczny

30

Process for license application development for the geologic repository  

SciTech Connect

The Department of Energy (DOE), specifically the Office of Civilian Radioactive Waste Management (OCRWM) has been charged by the US Congress, through the Nuclear Waste Policy Act (NWPA), with the responsibility for obtaining a license to develop a geologic repository. The NRC is the licensing authority for geologic disposal, and its regulations pertinent to construction authorization and license application are specified in 10 CFR Part 60, Disposal of High-Level Radioactive Wastes in Geologic Repositories, {section}60.21ff and {section}60.31ff. This paper discusses the process the Yucca Mountain Site Characterization Project (YMP) will use to identify and apply regulatory and industry guidance to development of the license application (LA) for a geologic repository at Yucca Mountain, Nevada. This guidance will be implemented by the Technical Guidance Document for Preparation of the License Application (TGD), currently in development.

Franks, D.M. [Duke Engineering and Services, Las Vegas, NV (United States); Henderson, N.C.

1998-06-01

31

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

32

Geology and Surface Processes on Titan  

Microsoft Academic Search

The surface of Titan has been revealed globally, if incompletely, by Cassini observations at infrared and radar wavelengths as well as locally by the instruments on the Huygens probe. Extended dune fields, lakes, mountainous terrain, dendritic erosion patterns and erosional remnants indicate dynamic surface processes. Valleys, small-scale gullies and rounded cobbles such as those observed at the Huygens landing site

Ralf Jaumann; Randolph L. Kirk; Ralph D. Lorenz; Rosaly M. C. Lopes; Ellen Stofan; Elizabeth P. Turtle; Horst Uwe Keller; Charles A. Wood; Christophe Sotin; Laurence A. Soderblom; Martin G. Tomasko

2010-01-01

33

Fundamental studies of chemical vapor deposition diamond growth processes  

SciTech Connect

We are developing laser spectroscopic techniques to foster a fundamental understanding of diamond film growth by hot filament chemical vapor deposition (CVD). Several spectroscopic techniques are under investigation to identify intermediate species present in the bulk reactor volume, the thin active volume immediately above the growing film, and the actual growing surface. Such a comprehensive examination of the overall deposition process is necessary because a combination of gas phase and surface chemistry is probably operating. Resonantly enhanced multiphoton ionization (REMPI) techniques have been emphasized. A growth rector that permits through-the-substrate gas sampling for REMPI/time-of-flight mass spectroscopy has been developed. 7 refs., 2 figs.

Shaw, R.W.; Whitten, W.B.; Ramsey, J.M.; Heatherly, L.

1991-01-01

34

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

35

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

36

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.

37

Modeling the Fundamental Characteristics and Processes of the Spacecraft Functioning.  

National Technical Information Service (NTIS)

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 spacecraf...

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

1986-01-01

38

FUNDAMENTAL CHEMISTRY AND THERMODYNAMICS OF HYDROTHERMAL OXIDATION PROCESSES  

EPA Science Inventory

The purpose of this research is to determine experimentally the fundamental thermodynamic and phase-equilibrium properties which control inorganic chemical reactions in high-temperature aqueous solutions as directly related to the assessment of technology and avoidance of problem...

39

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

40

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.

Bergman, Jennifer

2009-08-03

41

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

42

Continuum Scale Simulation of Engineering Materials: Fundamentals - Microstructures - Process Applications  

NASA Astrophysics Data System (ADS)

Everything the reader needs to know about this hot topic in materials research -- from the fundamentals to recent applications. This book addresses graduate students and professionals in materials science and engineering as well as materials-oriented physicists and mechanical engineers, providing them with information needed to judge which simulation method to use for which kind of modeling/simulation problem.

Raabe, Dierk; Roters, Franz; Barlat, Frédéric; Chen, Long-Qing

2004-08-01

43

Teaching Creative Problem Solving Using the Fundamentals of Manufacturing Processes  

Microsoft Academic Search

Manufacturing addresses the problem of converting raw materials into desired shapes with functional characteristics that are affected by the manufacturing processes themselves. Manufacturing problems were used to teach problem solving techniques in a Manufacturing Processes course at Gonzaga University. The students solved the problems to develop processes and the equipment to implement the processes. They analyzed and designed parts, and

Douglas L. Ramers

44

Geologic Mapping, Volcanic Stages and Magmatic Processes in Hawaiian Volcanoes  

NASA Astrophysics Data System (ADS)

The concept of volcanic stages arose from geologic mapping of Hawaiian volcanoes. Subaerial Hawaiian lava successions can be divided generally into three constructional phases: an early (shield) stage dominated by thin-bedded basaltic lava flows commonly associated with a caldera; a later (postshield) stage with much thicker bedded, generally lighter colored lava flows commonly containing clinopyroxene; calderas are absent in this later stage. Following periods of quiescence of a half million years or more, some Hawaiian volcanoes have experienced renewed (rejuvenated) volcanism. Geological and petrographic relations irrespective of chemical composition led to the identification of mappable units on Niihau, Kauai, Oahu, Molokai, Maui and Hawaii, which form the basis for this 3-fold division of volcanic activity. Chemical data have complicated the picture. There is a growing tendency to assign volcanic stage based on lava chemistry, principally alkalicity, into tholeiitic shield, alkalic postshield, and silica undersaturated rejuvenation, despite the evidence for interbedded tholeiitic and alkalic basalts in many shield formations, and the presence of mildly tholeiitic lavas in some postshield and rejuvenation formations. A consistent characteristic of lava compositions from most postshield formations is evidence for post-melting evolution at moderately high pressures (3-7 kb). Thus, the mapped shield to postshield transitions primarily reflect the disappearance of shallow magma chambers (and associated calderas) in Hawaiian volcanoes, not the earlier (~100 ka earlier in Waianae Volcano) decline in partial melting that leads to the formation of alkalic parental magmas. Petrological signatures of high-pressure evolution are high-temperature crystallization of clinopyroxene and delayed crystallization of plagioclase, commonly to <3 % MgO. Petrologic modeling using pMELTS and MELTS algorithms allows for quantification of the melting and fractionation conditions giving rise to various Hawaiian lithologies. This analysis indicates that the important magmatic process that links geologic mapping to volcanic stage is thermal state of the volcano, as manifest by depth of magma evolution. The only criterion for rejuvenation volcanism is the presence of a significant time break (more than several hundred thousand years) preceding eruption.

Sinton, J. M.

2005-12-01

45

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

46

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...

47

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

Microsoft Academic Search

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

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

1994-01-01

48

Teaching Introductory Geology by a Paradigm, Process and Product Approach  

NASA Astrophysics Data System (ADS)

Students in introductory geology courses can easily become lost in the minutiae of terms and seemingly random ideas and theories. One way to avoid this and provide a holistic picture of each major subject area in a beginning course is to introduce, at the start of each section, the ruling paradigm, the processes, and resultant products. By use of these three Ps: paradigm, processes, and products, students have a reasonably complete picture of the subject area. If they knew nothing more than this simple construct, they would have an excellent perspective of the subject area. This provides a jumping off point for the instructor to develop the details. The three Ps can make course construction much more straightforward and complete. Students benefit since they have a clearer idea of what the subject is about and its importance. Retention may be improved and carryover to advanced courses may be aided. For faculty, the use of these three P's makes organizing a course more straightforward. Additionally, the instructor benefits include: 1. The main points are clearly stated, thus avoiding the problem of not covering the essential concepts. 2. The course topics hold together, pedagogically. There is significant opportunity for continuity of thought. 3. An outline is developed that is easily analyzed for holes or omissions. 4. A course emerges with a balance of topics, permitting appropriate time to be devoted to significant subject matter. 5. If a course is shared between faculty or passes from one faculty to another by semester or quarter, there is greater assurance that topics and concepts everyone agrees on can be adequately covered. 6. There is less guesswork involved in planning a course. New faculty have an approach that will make sense and allow them to feel less awash and more focused. In summary, taking time to construct a course utilizing the important paradigms, processes, and products can provide significant benefits to the instructor and the student. Material can be presented in a more coherent manner and allow students the opportunity to grasp essential concepts from the very beginning. There are fewer potential surprises and greater likelihood that key ideas can be retained, as opposed to retaining isolated fragments of information. Illustrations from over a decade of use in an introductory Physical and Historical Geology course will be presented.

Reams, M.

2008-12-01

49

Writing is FUNdamental: Composition and Word Processing Curriculum.  

ERIC Educational Resources Information Center

The paper describes a computer/writing curriculum for hearing impaired and language disabled students which incorporates word processors with the process approach to writing. Such an approach emphasizes writing as a communication process and allows students to select their own writing topics and work independently or as a group. The curriculum is…

Lederer, James B.; And Others

50

Towards understanding how surface life can affect interior geological processes: a non-equilibrium thermodynamics approach  

Microsoft Academic Search

Life has significantly altered the Earth's atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated

J. G. Dyke; F. Gans; A. Kleidon

2011-01-01

51

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

52

Process fundamentals of membrane emulsification : simulation with CFD  

Microsoft Academic Search

Membrane emulsification is a process in which a to-be-dispersed phase is pressed through a membrane; the droplets formed are carried away with the continuous phase. To design a suitable membrane setup, more insight into the formation of the droplets at the membrane surface is needed. Therefore, the formation of one droplet from a cylindrical pore was calculated using computational fluid

A. J. Abrahamse; A. van der Padt; R. M. Boom; Heij de W. B. C

2001-01-01

53

Fundamental differences between spray forming and other semisolid processes  

Microsoft Academic Search

The distinguished microstructural features of spray formed products are the refined equiaxed grain structure and lower segregation level. Attempts have been made in the past to propose mechanisms to explain the formation of equiaxed grain structure. Recently there has been a tendency in correlating spray forming with other semisolid processes such as liquid phase sintering (LPS) and rheocasting. In this

Yu Fuxiao; Cui Jianzhong; S. Ranganathan; E. S. Dwarakadasa

2001-01-01

54

Understanding of fundamentals. Key to process modification for tailings reduction  

SciTech Connect

The tailings produced during bitumen separation from oil sands have a high water holding capacity attributed to ultrafine ([le] 0.2 [mu]m), aluminosilicate clay fractions. These components readily form gels within which both fine and coarse particles may be embedded. This complex mixture (or [open quotes]fine tails[close quotes]) shows poor dewatering and consolidation characteristics. In this work it has been demonstrated that for gel formation to occur an appropriate combination of ultrafines (amount and particle size) and water chemistry is needed. The natural salt concentration in water recycled from the tailings or pore (connate) water is sufficient to cause the ultrafines to form gels in a matter of days. Gel formers are an integral part of oil sands ores which are unavoidably released during processing. However, one way to prevent gel formation is to change the water chemistry in the extraction process where the bitumen is released. This can be achieved by the addition of sodium silicate instead of sodium hydroxide as process aid in the initial oil sands conditioning step. 8 refs., 3 figs., 1 tab.

Kotlyar, L.S.; Sparks, B.D.; Woods, J.R. (Inst. for Environmental Chemistry, Ottawa, Ontario (Canada)); Schutte, R. (Syncrude Canada Ltd., Edmonton, Alberta (Canada))

1993-12-01

55

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

Microsoft Academic Search

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

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

1996-01-01

56

Fundamental research on novel process alternatives for coal gasification: Final report  

Microsoft Academic Search

The Institute of Gas Technology has conducted a fundamental research program to determine the technical feasibility of and to prepare preliminary process evaluations for two new approaches to coal gasification. These two concepts were assessed under two major project tasks: Task 1. COâ-Coal Gasification Process Concept; Task 2. Internal Recirculation Catalysts Coal Gasification Process Concept. The first process concept involves

A. H. Hill; R. A. Knight; G. L. Anderson; H. L. Feldkirchner; S. P. Babu

1986-01-01

57

Computational Methods for Fundamental Studies Of Plasma Processes  

NASA Astrophysics Data System (ADS)

We present a combination of a wide range of computational methods that permits us to perform in-depth numerical studies of processes taking place in silicon/hydrogen plasma reactors during the fabrication of solar cells by means of Plasma Enhanced Chemical Vapor Deposition (PECVD). Notably, our investigations are motivated by the question under which plasma conditions hydrogenated silicon SinHm (n<=20) clusters become amorphous or crystalline. A crystalline structure of those nanoparticles is crucial, for example, for the electrical properties and stability of polymorphous solar cells. First, we use fluid dynamics model calculations to characterize the experimentally employed hydrogen/silane plasmas. The resulting relative densities for all plasma radicals, their temperatures, and their collision interval times are then used as input data for detailed semi-empirical molecular dynamics (MD) simulations. As a result, the growth dynamics of nanometric hydrogenated silicon SinHm clusters is simulated starting out from the collision of individual SiHx (x = 1-3) radicals under the plasma conditions derived above. We demonstrate how the plasma conditions determine the amorphous or crystalline character of the forming nanoparticles. Finally, we show a preliminary absorption spectrum based on ab initio time-dependent density-functional theory (DFT) calculations for a crystalline cluster to demonstrate the possibility to monitor cluster growth in situ.

Ning, N.; Dolgonos, G.; Morscheidt, W.; Michau, A.; Hassouni, K.; Vach, H.

2007-11-01

58

Risk Assessment based on the Mathematical Model of Diffuse Exogenous Geological Processes  

Microsoft Academic Search

The estimation of the risk caused by hazardous geological processes is a common problem. The aim of this paper is to present\\u000a a method for solving problems involving a wide spectrum of diffuse exogenous geological processes, based on the mathematical\\u000a morphology of landscapes. Diffuse processes develop as random rounded sites within certain areas and include karstification,\\u000a subsidence, thermo-karstification and aeolian

Alexey Viktorov

2007-01-01

59

Investigation of the Structure of Geological Process through Multivariate Statistical Analysis—The Creation of a Coal  

Microsoft Academic Search

The purpose of this study was to capture the structure of a geological process within a multivariate statistical framework\\u000a by using geological data generated by that process and, where applicable, by associated processes. It is important to the\\u000a practitioners of statistical analysis in geology to determine the degree to which the geological process can be captured and\\u000a explained by multivariate

Lawrence J. Drew; Eric C. Grunsky; John H. Schuenemeyer

2008-01-01

60

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

61

The nuclear microprobe as a probe of earth structure and geological processes  

NASA Astrophysics Data System (ADS)

The nuclear microprobe is ideally suited to the microanalysis of geological samples where trace element quantitative microanalysis and imaging are essential. The use of these methods, particularly proton-induced X-ray emission (PIXE), is becoming more common in many areas of geology as the impact of trace element data become more widely appreciated. This review provides an update on the progress of geological applications of the nuclear microprobe since these were reviewed at the previous conference on Nuclear Microprobe Technology and Applications in 1992. But more importantly, the applications described in more detail in this paper are chosen to illustrate the impact nuclear microprobe methods are having on our understanding of earth structure and geological processes, and to focus attention on the power and potential of quantitative nuclear microprobe methods for further geological research.

Ryan, C. G.

1995-09-01

62

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

Microsoft Academic Search

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

P. Stelling; S. Wuotila; M. Giuliani

2006-01-01

63

Geologic processes and Cenozoic history related to salt dissolution in southeastern New Mexico  

USGS Publications Warehouse

Salt of Permian age in the subsurface of an area near The Divide, east of Carlsbad, N. Mex., is being considered for a nuclear waste repository. The geologic history of the region indicates that dissolution of salt has occurred in the past during at least three distinct epochs: (1) after Triassic but before middle Pleistocene time; (2) during middle Pleistocene; and (3) during late Pleistocene. Thus, destructive geologic processes have been intermittent through more than I00 million years. Nash Draw, near The Divide, formed during late Pleistocene time by the coalescing of collapse sinks. The rate of its subsidence is estimated to have been about 10 cm (0.33 foot) per thousand years. The immediate area of The Divide adjacent to Nash Draw has not undergone stress by geologic processes during Pleistocene time and there are no present indications that this geologic environment will change drastically within the period of concern for the repository.

Bachman, George Odell

1974-01-01

64

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...

65

Engineering geological characteristics and processes of permafrost along the Qinghai–Xizang (Tibet) Highway  

Microsoft Academic Search

Engineering geological problems of thaw-settlement and frost-heave occur frequently along the Qinghai–Xizang (Tibet) Highway (QXH) line and produce an adverse impact on roadbed stability. Eight monitoring sites were established along the QXH to investigate the engineering geological characteristics and environmental process of permafrost, including the upper and lower boundary of the active layer under the natural surface, the seasonal freeze–thaw

Qingbai Wu; Bin Shi; Hsai-Yang Fang

2003-01-01

66

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

67

Refining Martian Ages and Understanding Geological Processes From Cratering Statistics  

NASA Technical Reports Server (NTRS)

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

68

Combining geologic-process models and geostatistics for conditional simulation of 3-D subsurface heterogeneity  

NASA Astrophysics Data System (ADS)

The goal of simulation of aquifer heterogeneity is to produce a spatial model of the subsurface that represents a system such that it can be used to understand or predict flow and transport processes. Spatial simulation requires incorporation of data and geologic knowledge, as well as representation of uncertainty. Classical geostatistical techniques allow for the conditioning of data and uncertainty assessment, but models often lack geologic realism. Simulation of physical geologic processes of sedimentary deposition and erosion (process-based modeling) produces detailed, geologically realistic models, but conditioning to local data is limited at best. We present an aquifer modeling methodology that combines geologic-process models with object-based, multiple-point, and variogram-based geostatistics to produce geologically realistic realizations that incorporate geostatistical uncertainty and can be conditioned to data. First, the geologic features of grain size, or facies, distributions simulated by a process-based model are analyzed, and the statistics of feature geometry are extracted. Second, the statistics are used to generate multiple realizations of reduced-dimensional features using an object-based technique. Third, these realizations are used as multiple alternative training images in multiple-point geostatistical simulation, a step that can incorporate local data. Last, a variogram-based geostatistical technique is used to produce conditioned maps of depositional thickness and erosion. Successive realizations of individual strata are generated in depositional order, each dependent on previously simulated geometry, and stacked to produce a fully conditioned three-dimensional facies model that mimics the architecture of the process-based model. We demonstrate the approach for a typical subsea depositional complex.

Michael, H. A.; Li, H.; Boucher, A.; Sun, T.; Caers, J.; Gorelick, S. M.

2010-05-01

69

Fundamental performance metrics and optimal image processing strategies for ultrasound systems  

Microsoft Academic Search

Fundamental limits on imaging system performance are developed using Bayesian signal detection theory. The analysis expands upon the wellknown theory of Smith and Wagner. Envelope-detected signals are shown to be sub-optimal for detection tasks. Two image processing strategies are presented that may improve upon current B-mode processing: deconvolution and wavefront curvature matched filtering. The later technique takes advantage of remarkable

Roger J. Zemp; Craig K. Abbey; Michael F. Insana

2002-01-01

70

Femtosecond pulsed laser processing of electronic materials: Fundamentals and micro\\/nano-scale applications  

Microsoft Academic Search

Ultra-short pulsed laser radiation has been shown to be effective for precision materials processing and surface micro-modification. One of advantages is the substantial reduction of the heat penetration depth, which leads to minimal lateral damage. Other advantages include non-thermal nature of ablation process, controlled ablation and ideal characteristics for precision micro-structuring. Yet, fundamental questions remain unsolved regarding the nature of

Tae-Youl Choi

2002-01-01

71

Fundamental research on novel process alternatives for coal gasification. Progress report, May 7August 6, 1984  

Microsoft Academic Search

The objectives of this research program are (1) to determine the technical feasibility of and (2) to prepare preliminary process evaluations for each of two new approaches to coal gasification. The objective of Task 1, COâ-Coal Gasification Concept, is to obtain fundamental information on a novel coal gasification process concept that involves pressurized carbon dioxide-coal gasification followed by a high-temperature

Babu

1984-01-01

72

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.

Miller, Marli B.; Oregon, University O.

73

Processes in karst systems, physics, chemistry, and geology  

SciTech Connect

Dreybrodt deals quantitatively with many of the chemical and hydrological processes involved in the formation of karst systems. The book is divided into 3 major parts. The first part develops the basic chemical and fluid-flow principles needed in modeling karst systems. The second part investigates the experimental kinetics of calcite dissolution and precipitation and applies the resulting kinetic laws to the modeling of these processes in systems both open and closed to carbon dioxide. The last part of the book includes a qualitative examination of karst systems, quantitative modeling of the development of karst features, and an examination and modeling of the growth of spelotherms in caves.

Dreybrodt, W.

1988-01-01

74

Pump-probe spectroscopy in organic semiconductors: monitoring fundamental processes of relevance in optoelectronics.  

PubMed

In this review we highlight the contribution of pump-probe spectroscopy to understand elementary processes taking place in organic based optoelectronic devices. The techniques described in this article span from conventional pump-probe spectroscopy to electromodulated pump-probe and the state-of-the-art confocal pump-probe microscopy. The article is structured according to three fundamental processes (optical gain, charge photogeneration and charge transport) and the contribution of these techniques on them. The combination of these tools opens up new perspectives for assessing the role of short-lived excited states on processes lying underneath organic device operation. PMID:22020959

Cabanillas-Gonzalez, Juan; Grancini, Giulia; Lanzani, Guglielmo

2011-12-01

75

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

76

The Interactions of Contextualization and Abstraction Within and Between Media: A Fundamental Process of Media Ecology  

Microsoft Academic Search

Contextual and abstract-dominant media, as related to the auditory\\/visual duality of media in McLuhan's term and heavy\\/light dichotomy in Innis’s terms, are both complementary and competitive. This paper explores the processes of contextualization and abstraction as fundamental aspects within every medium. I use this thesis to explore their roles in the interactions between media. There have been relatively few attempts

Norman Steinhart

77

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.

78

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

SciTech Connect

During the past three year grant period, we have focussed efforts on four major areas on investigation. All of these topics are related to the fundamental features of photo-induced charge separation at semiconductor/liquid interfaces. This report presents work in each of the four research areas: cyclic voltammetry theory and current-voltage theory, short wavelength photocurrent measurements, photoelectrochemical processing to make improved solid/state photovoltaic devices, and photoelectrochemistry and surface chemistry of GaAs.

Lewis, N.S.

1990-05-02

79

Active geologic processes in Barrow Canyon, northeast Chukchi Sea  

USGS Publications Warehouse

Circulation patterns on the shelf and at the shelf break appear to dominate the Barrow Canyon system. The canyon's shelf portion underlies and is maintained by the Alaska Coastal Current (A.C.C.), which flows northeastward along the coast toward the northeast corner of the broad Chukchi Sea. Offshelf and onshelf advective processes are indicated by oceanographic measurements of other workers. These advective processes may play an important role in the production of bedforms that are found near the canyon head as well as in processes of erosion or non-deposition in the deeper canyon itself. Coarse sediments recovered from the canyon axis at 400 to 570 m indicate that there is presently significant flow along the canyon. The canyon hooks left at a point north of Point Barrow where the A.C.C. loses its coastal constriction. The left hook, as well as preferential west-wall erosion, continues down to the abyssal plain of the Canada Basin at 3800 m. A possible explanation for the preferential west-wall erosion along the canyon, at least for the upper few hundred meters, is that the occasional upwelling events, which cause nutrient-rich water to flow along the west wall would in turn cause larger populations of burrowing organisms to live there than on the east wall, and that these organisms cause high rates of bioerosion. This hypothesis assumes that the dominant factor in the canyon's erosion is biological activity, not current velocity. Sedimentary bedforms consisting of waves and furrows are formed in soft mud in a region on the shelf west of the canyon head; their presence there perhaps reflects: (a) the supply of fine suspended sediments delivered by the A.C.C. from sources to the south, probably the Yukon and other rivers draining northwestern Alaska; and (b) the westward transport of these suspended sediments by the prevailing Beaufort Gyre which flows along the outer shelf. ?? 1982.

Eittreim, S.; Grantz, A.; Greenberg, J.

1982-01-01

80

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

SciTech Connect

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 processes that in turn affect a geologic process, like climatic change. It reviews the literature in several fields to determine whether existing probabilistic methods for predicting events and processes are adequate for implementation of the standard. Techniques exist for qualitatively estimating the potential for endowment of portions of earth's crust with mineral resources, but such techniques cannot easily predict whether or not human intrusion will occur. The EPA standard offers explicit guidance for the treatment of human intrusion, however. A complete method for climatic prediction could be assembled from existing techniques, although such a combination has not been tested. Existing techniques to support a probabilistic assessment of tectonic activity and seismic hazard at a repository site should be combined with expert judgment in performance assessments. Depending on the regional setting, either analytic techniques or expert judgment may be appropriate in assigning probabilities to volcanic activity. The individual chapters of this report have been cataloged separately.

Hunter, R.L.; Mann, C.J. (eds.)

1989-06-01

81

Use of clay minerals in reconstructing geological processes: recent advances and some perspectives  

Microsoft Academic Search

This article reviews that clay literature from the last ten years, which is devoted to the applications of clay minerals in the interpretation of geological processes in sedimentary basins. The results, selected by the author as being of particular interest, are presented, arranged according to the successive phases of the rock cycle. The research field defined in the title has

J. Srodon

1999-01-01

82

Time-lapse motion picture technique applied to the study of geological processes  

USGS Publications Warehouse

Light-weight, battery-operated timers were built and coupled to 16-mm motion-picture cameras having apertures controlled by photoelectric cells. The cameras were placed adjacent to Emmons Glacier on Mount Rainier. The film obtained confirms the view that exterior time-lapse photography can be applied to the study of slow-acting geologic processes.

Miller, R. D.; Crandell, D. R.

1959-01-01

83

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

Microsoft Academic Search

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

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

1995-01-01

84

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

85

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

86

Digital image processing: a primer for JVIR authors and readers: part 1: the fundamentals.  

PubMed

Online submission of manuscripts will be mandatory for most journals in the near future. To prepare authors for this requirement and to acquaint readers with this new development, herein the basics of digital image processing are described. From the fundamentals of digital image architecture, through acquisition, editing, and storage of digital images, the steps necessary to prepare an image for online submission are reviewed. In this article, the first of a three-part series, the structure of the digital image is described. In subsequent articles, the acquisition and editing of digital images will be reviewed. PMID:14551267

LaBerge, Jeanne M; Andriole, Katherine P

2003-10-01

87

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

88

Fundamental processes of refractive index modifications during femtosecond laser waveguide writing  

NASA Astrophysics Data System (ADS)

By using focused ultrashort pulsed laser radiation refractive index modifications are induced in glass in order to generate optical components. The understanding of physically fundamental processes induced by laser radiation is the basis for the systematic control and maximization of the refractive index change for the realization of three-dimensional, optical components for integrated optics like in-volume waveguides. In this paper fundamental processes which are induced by focused laser radiation in the volume of borosilicate glass D263 and fused silica are investigated. The glass materials are structured by laser radiation in the infrared spectral range (?=1045nm). By using femtosecond laser pulses with high repetition rates (f = 500 kHz), thermal processes like heat accumulation effects are induced leading to heat affected zones and thus waveguide cross sections with dimensions larger than the focal spot. The absorptivity during modification in relation to the applied pulse energy is measured for different repetition rates in both glass materials. Furthermore, the laser induced structural change in the glass matrix by the increase of three- and four-membered ring structures is proved with Raman spectroscopy.

Schaefer, D.; Schnitzler, D.; Kelbassa, I.

2013-03-01

89

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

90

Recent developments in modeling of hot rolling processes: Part I - Fundamentals  

NASA Astrophysics Data System (ADS)

The numerical simulation of industrial rolling processes has gained substantial relevance over the past decades. A large variety of models have been put forward to simulate single and multiple rolling passes taking various interactions between the process, the microstructure evolution and the rolling mill into account. On the one hand, these include sophisticated approaches which couple models on all scales from the product's microstructure level up to the elastic behavior of the roll stand. On the other hand, simplified but fast models are used for on-line process control and automatic pass schedule optimization. This publication gives a short overview of the fundamental equations used in modeling of hot rolling of metals. Part II of this paper will present selected applications of hot rolling simulations.

Hirt, Gerhard; Bambach, Markus; Seuren, Simon; Henke, Thomas; Lohmar, Johannes

2013-05-01

91

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

92

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 an engineering technology base for development of large scale 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 for conducting experimental investigations. Oxidizer (LOX or GOX) is injected through the head-end over a solid fuel (HTPB) surface. Experiments using fuels supplied by NASA designated industrial companies will also be conducted. The study focuses on the following areas: measurement and observation of solid fuel burning with LOX or GOX, 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 also being conducted at PSU.

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

1994-01-01

93

Basic petroleum geology, 2nd Ed  

SciTech Connect

It presents the fundamental concepts of geology in terms of sedimentary deposition, petroleum occurrence, exploration, and recovery. It provides an integrated overview of petroleum geology concepts and vocabulary in easy to understand language. It is essential that geologists, geophysicists, and engineers share a common understanding of geologic processes which are presented in this book. It is just as important that petroleum managers, landmen, and technicians, as well as attorneys, financiers, and other nontechnical professionals be conversant with the terminology and fundamental principles of petroleum occurrence, exploration, and production.

Link, P.K.

1988-01-01

94

Fundamental change of granular flows dynamics, deposition and erosion processes at sufficiently high slope angles: insights from laboratory experiments  

NASA Astrophysics Data System (ADS)

Geophysical granular flows commonly interact with their substrate in various ways depending on the mechanical properties of the underlying material. Granular substrates, resulting from deposition of earlier flows or various geological events, are often eroded by avalanches [see Hungr and Evans, 2004 for review]. The entrainment of underlying debris by the flow is suspected to affect flow dynamics because qualitative and quantitative field observations suggest that it can increase the flow velocity and deposit extent, depending on the geological setting and flow type [Sovilla et al., 2006; Iverson et al., 2011]. Direct measurement of material entrainment in nature, however, is very difficult. We conducted laboratory experiments on granular column collapse over an inclined channel with and without an erodible bed of granular material. The controlling parameters were the channel slope angle, the granular column volume and its aspect ratio (i.e. height over length), the inclination of the column with respect to the channel base, the channel width, and the thickness and compaction of the erodible bed. For slope angles below a critical value ?c, between 10° and 16°, the runout distance rf is proportional to the initial column height h0 and is unaffected by the presence of an erodible bed. On slopes greater than ?c, the flow dynamics change fundamentally since a last phase of slow propagation develops at the end of the flow front deceleration, and prolongates significantly the flow duration. This phase has similar characteristics that steady, uniform flows. The slow propagation phase lasts longer for increasing column volume, column inclination with respect to the slope, and channel width, and for decreasing column aspect ratio. It is however independent of the maximum front velocity and, on an erodible bed, of the maximum depth of excavation within the bed. Both on rigid and erodible beds, the increase of the slow propagation phase duration has a crucial effect on the granular flows dynamics and deposition. (i) On a rigid bed, as the slow propagation phase lasts longer, the normalized runout distance rf/h0 is greater for a given slope angle and the front of the flow deposit becomes more round. (ii) On an erodible bed, increasing the duration of the slow phase causes the bed excavation to lasts longer and the increase of the runout distance compared with the case on the rigid bed to be greater; this is even more significant as the bed is less compact. For flows on an erodible bed and if the slope angle is high enough, waves of grains appear in the flow head, at the interface between the flow (white) and the bed (black). These waves are related to the erosion/deposition processes at the base of the flow.

Farin, M.; Mangeney, A.; Roche, O.

2013-12-01

95

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

96

Effects of cochlear implant processing and fundamental frequency on the intelligibility of competing sentences.  

PubMed

Speech perception in the presence of another competing voice is one of the most challenging tasks for cochlear implant users. Several studies have shown that (1) the fundamental frequency (F0) is a useful cue for segregating competing speech sounds and (2) the F0 is better represented by the temporal fine structure than by the temporal envelope. However, current cochlear implant speech processing algorithms emphasize temporal envelope information and discard the temporal fine structure. In this study, speech recognition was measured as a function of the F0 separation of the target and competing sentence in normal-hearing and cochlear implant listeners. For the normal-hearing listeners, the combined sentences were processed through either a standard implant simulation or a new algorithm which additionally extracts a slowed-down version of the temporal fine structure (called Frequency-Amplitude-Modulation-Encoding). The results showed no benefit of increasing F0 separation for the cochlear implant or simulation groups. In contrast, the new algorithm resulted in gradual improvements with increasing F0 separation, similar to that found with unprocessed sentences. These results emphasize the importance of temporal fine structure for speech perception and demonstrate a potential remedy for difficulty in the perceptual segregation of competing speech sounds. PMID:17672654

Stickney, Ginger S; Assmann, Peter F; Chang, Janice; Zeng, Fan-Gang

2007-08-01

97

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

98

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

99

Fundamental chemistry and thermodynamics of hydrothermal oxidation processes. 1997 annual progress report  

SciTech Connect

'The objective of this research program is to provide fundamental scientific information on the physical and chemical properties of solutes in aqueous solutions at high temperatures needed to assess and improve the applicability of hydrothermal oxidation (HTO) to the remediation of US Department of Energy (DOE) hazardous and mixed wastes. Investigators in two divisions at Oak Ridge National Laboratory (Chemical and Analytical Sciences, and Chemical Technology) and at the University of Tennessee are focused on the solubility and speciation of actinides and surrogates in model HTO process streams at high temperatures, on the experimental and theoretical development of equations of state for aqueous mixtures containing noncondensible gases under HTO process conditions ranging above the critical temperature of water, and on achieving a predictive level of understanding of the chemical and physical properties of HTO process streams through molecular-level simulations of aqueous solutions at high temperatures. Specific tasks in these three efforts over the past year include measurements of solubility and identification of stable solid phases for UO{sub 3} in aqueous carbonate solutions at temperatures above 100 C, measurements of fluid-phase coexistence boundaries and densities of mixtures in (H{sub 2}O + N{sub 2} + CO{sub 2}) mixtures at high temperatures and pressures, and molecular dynamics simulations of water and aqueous solutions addressing the speciation of simple ionic solutes and the structure of water and aqueous solutions as functions of temperature and density. Research in this project has been divided into individual tasks, each addressing a particular scientific question and each contributing to a unified understanding of HTO processing problems related to the treatment of DOE hazardous and mixed wastes. The three primary tasks are (1) the determination of solubilities of inorganic compounds including actinides and surrogates to determine their likely fate during HTO processing, (2) experimental and modeling studies of the density and phase behavior of (water + gas) mixtures at high temperatures to determine the physical state of the process fluid, and (3) simulations of water and aqueous solutions at high temperatures and comparison with experimental results as a method for the development of accurate, comprehensive descriptions of the properties of aqueous fluids.'

Simonson, J.M.; Mesmer, R.E.; Blencoe, J.G.; Cummings, P.T. [Oak Ridge National Lab., TN (US); Chialvo, A.A. [Univ. of Tennessee, Knoxville, TN (US)

1997-09-01

100

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

101

Fundamental aspects on ion-beam surface modification: defect production and migration processes  

SciTech Connect

Ion-beam modification of metals is generating increasing scientific interest not only because it has exciting technological potential, but also because it has raised fundamental questions concerning radiation-induced diffusion processes. In addition to the implanted species, several defect production and migration mechanisms contribute to changes in the near-surface composition of an alloy during ion bombardment, e.g., atoms exchange positions via displacements and replacement sequences; preferential sputtering effects arise; radiation-enhanced diffusion and radiation-induced segregation occur. The latter two defect migration mechanisms are of particular significance since they can alter the composition to depths which are much greater than the implanted ion range. By altering various parameters such as irradiation temperature, ion mass, energy, and current density, and initial alloying distributions, a rich variety of near-surface composition profiles can be created. We have utilized changes in ion mass and energy, and irradiation temperature to distinguish defect production from defect migration effects. Experimental results are presented which provide a guide to the relative efficiencies of different mechanisms under various irradiation conditions. 46 references.

Rehn, L.E.; Averback, R.S.; Okamoto, P.R.

1984-09-01

102

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

103

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

104

Fundamental processes and implications during in situ aeration of old landfills.  

PubMed

Results of investigations from many old landfills in Germany and Europe indicate that significant emissions occur under conventional landfill operating conditions (i.e., anaerobic conditions). Significant emissions via the gas phase are predicted to last at least three decades after landfill closure, while leachate emissions are predicted to continue for many decades, potentially even lasting for centuries. When considering the specific type and quality, and quite often lack of, protection barriers associated with old landfills, these leachate and gas emissions may result in a significant negative impact on the environment. However, complete sealing of the landfill only temporarily reduces emissions because dry-conservation of the biodegradable waste fraction results, thus not allowing any severe reduction in the emission and hazardous potential of the landfill to occur. If noticeable damage of the surface capping system occurred in these landfills, infiltrating water would restart the interrupted emission formation. In contrast, aerobic in situ stabilization by means of low pressure aeration attempts to stabilize and modify the inventory of organic matter inside the landfill, acting to reduce the emission potential in a more sustainable manner. By enabling faster and more extensive aerobic degradation processes in the landfill (compared with anaerobic processes), the organics (e.g., hydrocarbons) are degraded significantly faster, resulting in an increased carbon discharge via the gas phase, as well as reduced leachate concentrations. Because carbon dioxide (CO(2)) is the main compound in the extracted off-gas (instead of methane (CH(4)), which dominated under anaerobic landfill conditions), the negative impact of diffuse LFG emissions towards an increased global warming effect may be significantly lowered. With respect to leachate quality, a reduction of organic compounds as well as ammonia-nitrogen can be expected. In addition to these positive ecological effects, aerobic in situ stabilization is associated with significant cost savings potential due to both quantitative and qualitative reductions in the aftercare period. This paper describes the fundamental processes and implications of in situ landfill aeration. Additionally, possible criteria for defining an endpoint of the active aeration process are presented and discussed. PMID:16442789

Ritzkowski, M; Heyer, K-U; Stegmann, R

2006-01-01

105

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.

Ramsey, Michael S.; Pittsburgh, University O.

106

US GEOLOGICAL SURVEY'S NATIONAL SYSTEM FOR PROCESSING AND DISTRIBUTION OF NEAR REAL-TIME HYDROLOGICAL DATA.  

USGS Publications Warehouse

The US Geological Survey is utilizing a national network of more than 1000 satellite data-collection stations, four satellite-relay direct-readout ground stations, and more than 50 computers linked together in a private telecommunications network to acquire, process, and distribute hydrological data in near real-time. The four Survey offices operating a satellite direct-readout ground station provide near real-time hydrological data to computers located in other Survey offices through the Survey's Distributed Information System. The computerized distribution system permits automated data processing and distribution to be carried out in a timely manner under the control and operation of the Survey office responsible for the data-collection stations and for the dissemination of hydrological information to the water-data users.

Shope, Jr. , William, G.

1987-01-01

107

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

108

New processing of Luna archive panoramas and geologic assessment of the Lunokhod landing sites  

NASA Astrophysics Data System (ADS)

From the successful Soviet lunar missions Luna-9, Luna-13, Luna-17 (Lunokhod-1), Luna-20 and Luna-21 (Lunokhod-2) about 350 panoramas of the lunar surface were returned [2, 5, 11]. Unfortunately, only a small part of the data from the missions has been converted to digital form and made available for the scientific community. The main purpose of the FP7-project "PRoViDE" is to give scientists and the public access to data products from planetary surfaces of uniform quality (http://www.providespace. eu/). The MIIGAiK Extraterrestrial Laboratory (MExLab) task is to re-process lunar panoramas based on modern techniques [9], and then to subject them to more detailed geologic analyses [1, 3, 4].

Karachevtseva, I.; Kozlova, N.; Nadezhdina, I.; Zubarev, A.; Abdrakhimov, A.; Basilevsky, A.; Oberst, J.

2013-09-01

109

Development of a requirements management system for technical decision - making processes in the geological disposal project  

SciTech Connect

NUMO (Nuclear Waste Management Organization of Japan) has a responsibility for implementing geological disposal of vitrified HLW (High-Level radioactive Waste) in the Japanese nuclear waste management programme. Its staged siting procedure was initiated in 2002 by an open call for volunteer sites. Careful management strategy and methodology for the technical decision-making at every milestone are required to prepare for the volunteer site application and the site investigation stages after that. The formal Requirement Management System (RMS) is planned to support the computerized implementation of the specific management methodology, termed the NUMO Structured Approach (NSA). This planned RMS will help for comprehensive management of the decision-making processes in the geological disposal project, change management towards the anticipated project deviations, efficient project driving such as well programmed R and D etc. and structured record-keeping regarding the past decisions, which leads to soundness of the project in terms of the long-term continuity. The system should have handling/management functions for the database including the decisions/requirements in the project in consideration, their associated information and the structures composed of them in every decision-making process. The information relating to the premises, boundary conditions and time plan of the project should also be prepared in the system. Effective user interface and efficient operation on the in-house network are necessary. As a living system for the long-term formal use, flexibility to updating is indispensable. In advance of the formal system development, two-year activity to develop the preliminary RMS was already started. The purpose of this preliminary system is to template the decision/requirement structure, prototype the decision making management and thus show the feasibility of the innovative RMS. The paper describes the current status of the development, focusing on the initial stage including work analysis/modeling and the system conceptualization. (authors)

Hiroyoshi Ueda; Katsuhiko Ishiguro; Kazumi Kitayama [Nuclear Waste Management Organization of Japan (NUMO), Mita NN Bldg., 1-23, Shiba 4-Chome, Minato-ku, Tokyo 108-0014 (Japan); Kiyoshi Oyamada [JGC Corporation (Japan); Shoko Sato [Obayashi Corporation (Japan)

2007-07-01

110

High frequency fundamental resonators and filters fabricated by batch process using chemical etching  

Microsoft Academic Search

The small sized 1st intermediate frequency (IF) filters at center frequency range of 70 MHz to 150 MHz and passband widths of ±5 to ±100 kHz with sharp selectivity are required in mobile communication systems such as mobile and portable cellular phone. Our solution to employ fundamental mode monolithic crystal filter (MCF) assembled in surface mountable package. We describe here

O. Ishii; T. Morita; T. Saito; Y. Nakazawa

1995-01-01

111

New processing of Cassini/VIMS data on potentially geologically varying regions  

NASA Astrophysics Data System (ADS)

We present a study of Titan's geology with a view to enhance our current understanding of the satellite's potentially geologically varying regions. We apply here a statistical method, the Principal Component Analysis (PCA) [1, 2] and a radiative transfer method [3, 1] on three potentially "active" regions on Titan, i.e. regions possibly subject to change over time (in brightness and/or in color etc) [4] namely Tui Regio, Hotei Regio, and Sotra Facula. With our method of PCA we have managed to isolate specific regions of distinct and diverse chemical composition. Then, with our follow-up RT method, we retrieved the surface albedo of the three isolated regions and of the surrounding terrains with different spectral response. These methods enabled us to evaluate the atmospheric contribution and allowed us to better constrain the real surface alterations, by comparing the spectra of these regions. Finally, the temporal surface variation of Hotei Regio as suggested by Nelson et al. 2009 [5], has been tested through the use of the RT method while we have superimposed this area's Cassini Visual and Infrared Mapping Spectrometer (VIMS) and RADAR data in order to 'view' the morphological potential. Even though we have used exactly the same dataset as Nelson and coauthors in 2009, we did not detect any significant surface albedo variations over time; this led us to revise the definition of "active" regions: even if these regions have not visually changed over the course of the Cassini mission, the determination of the chemical composition and the correlation with the morphological structures [6] observed in these areas do not rule out that past and/or ongoing cryovolcanic processes are still a possible interpretation.

Solomonidou, A.; Hirtzig, M.; Bratsolis, E.; Bampasidis, G.; Coustenis, A.; Kyriakopoulos, K.; Le Mouélic, S.; Rodriguez, S.; Jaumann, R.; Stephan, K.; Drossart, P.; Sotin, C.; Brown, R. H.; Seymour, K.; Moussas, X.

2012-09-01

112

Predictive information processing is a fundamental learning mechanism present in early development: evidence from infants.  

PubMed

Evidence is presented that predictive coding is fundamental to brain function and present in early infancy. Indeed, mismatch responses to unexpected auditory stimuli are among the earliest robust cortical event-related potential responses, and have been measured in young infants in response to many types of deviation, including in pitch, timing, and melodic pattern. Furthermore, mismatch responses change quickly with specific experience, suggesting that predictive coding reflects a powerful, early-developing learning mechanism. PMID:22226901

Trainor, Laurel J

2012-02-01

113

(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

114

[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

115

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

116

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

Microsoft Academic Search

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

Kirk Duncan McIntosh

1992-01-01

117

Antarctic Dry Valley analogs for Mars gullies: Geological setting and processes  

NASA Astrophysics Data System (ADS)

Malin and Edgett [1,2] initially described a class of young features on Mars that they termed gullies, consisting of an alcove, a channel and a fan. Restricted to middle and high latitude locations, these features were interpreted to have originated through processes related to the presence of liquid water (through groundwater discharge); the potential presence of liquid water on the surface of Mars currently or in the very recent geological past, when liquid water is metastable [3], generated a host of alternative explanations for the gullies [see summary in 4]. Detailed analysis of the conditions under which H2O could flow as a liquid in the current Mars environment shows a range of conditions under which gully-forming activity is possible [3,5]. Recent observations of changes in gullies, interpreted to mean that a few gullies are currently active [6], have intensified this discussion. Terrestrial analogs to martian environments may provide insight into the processes operating on Mars. For example, the nature of perennial saline springs forming channels on Axel Heiberg Island in the Canadian High Arctic has been used to support the argument that martian gullies formed from subsurface groundwater springs [7]. In this analysis we report on the results of ongoing [8-11] field studies in the Antarctic Dry Valleys (ADV), a hyperarid polar desert analog for Mars [11].

Head, J. W.; Marchant, D. R.; Dickson, J. L.; Levy, J. S.; Morgan, G. A.

2008-09-01

118

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.

Severson, Laurie

119

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

120

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

121

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

122

Upscaling of two-phase flow processes in CO2 geological storage  

NASA Astrophysics Data System (ADS)

Only few current multiphase flow and reactive transport models take into account the impact of heterogeneity on front spreading and mass transfer between high and low permeability zones of the heterogeneous medium and the impact of physical heterogeneity and chemical heterogeneity on chemical reactions rates. Effective equations are available for single-phase conservative and reactive transport and under development for multiphase flow. In the present work, we aim specifically at the upscaling of the two-phase flow dynamics related to processes of CO2 geological storage. The impact of heterogeneity on the two-phase flow dynamics can be quantified in the framework of a multi-continuum approach. This approach allows for the quantification of mass exchange between mobile (background material) and immobile (inclusions) zones of the medium. In this way it accounts systematically for local scale non-equilibrium and thus for the complex flow dynamics in highly heterogeneous and fractured media. The mass exchange between mobile and immobile zones is taken into account by a Multi-Rate Mass Transfer (MRMT) model. Effective equations were formulated in order to describe the impact of spatial heterogeneity on the large-scale two-phase flow behavior. The model was implemented into a MatLab code. Heterogeneity in the hydraulic conductivity of the storage aquifer was accounted through a Gaussian random field. Numerical simulations of 2D two-phase flow through this heterogeneous media were run to obtain the evolution of the actual CO2-rich phase saturation distribution. An equivalent effective model of 1D two-phase flow in homogenous media with MRMT was used to describe the 2D heterogeneous results. The numerical simulations show that a simple 1D homogeneous model with MRMT, capillarity at mobile-immobile interface and in the mobile zone is able to describe two-phase flow in heterogeneous media. However, gravity and macrodispersion terms still have to be included. Extension to heterogeneous multiphase flow is straightforward. The present methodology could contribute significantly to the quantification of the heterogeneity-induced uncertainty of the predicted large-scale multiphase flow and transport behavior in CO2 geological storage.

Silva, O.; Neuweiler, I.; Dentz, M.; Saaltink, M.; Carrera, J.

2012-04-01

123

Marine Geology of the Southwestern San Juan Islands: New Insights From Multibeam Imagery and Processed Aeromagnetic Data  

NASA Astrophysics Data System (ADS)

The San Juan Islands, located in the seismically active northern Puget Sound, have a complicated and not yet fully understood geologic history. This study is among the first marine geologic mapping efforts within the San Juan Islands, filling an important gap in an otherwise well-studied region. Existing geologic and geophysical data were combined with interpretations of new multibeam bathymetry and backscatter seafloor imagery to construct a seamless onshore - offshore geologic map of the southwestern San Juan Islands. Simrad EM1002 (95 kHz) and Reson 8101 (240 kHz) multibeam bathymetry and backscatter data were collected between October 2000 and November 2003 within Haro Strait, northeastern Strait of Juan de Fuca, and San Juan Channel. Sun-shaded images of the processed data reveal a complex network of faulted and fractured bedrock exposures, deep glaciated channels, Pleistocene glacial sediments, and dynamic bedforms. Distinct slump morphologies in multibeam and backscatter imagery suggest active slumping of recent sediments at the mouth of San Juan Channel. A number of previously inferred offshore geologic structures were extended and constrained based on distinct linear bedrock features visible in the multibeam imagery. Aeromagnetic data collected by the U.S. Geological Survey in 1997 were processed to accentuate short-wavelength, presumably shallow, magnetic sources. The resultant derivative aeromagnetic map reveals a number of areas with distinctive anomaly patterns. Gradients in magnetic anomalies often corresponded with fault traces identified in high-resolution multibeam imagery and may reflect slight magnetic susceptibility contrasts across fault contacts. Aeromagnetic data also constrain two tectonostratigraphic terrane boundaries not identified in multibeam imagery: 1) the Buck Bay fault, which separates the Lopez Structural Complex and Decatur terrane from the underlying Constitution Formation, and 2) the Haro fault separating the Deadman Bay terrane of the San Juan Thrust system from the Wrangellia terrane on Vancouver Island.

Tilden, J. E.; Greene, H. G.; Blakely, R. J.

2004-12-01

124

77 FR 34062 - Announcement of the U.S. Geological Survey Science Strategy Planning Feedback Process  

Federal Register 2010, 2011, 2012, 2013

...the U.S. Geological Survey Science Strategy Planning Feedback...and Land Use Change, Core Science Systems, Ecosystems, Energy...Minerals, Environmental Health, Natural Hazards, and Water. This...usgs.gov/start_with_science. DATES: The comment...

2012-06-08

125

77 FR 43110 - Announcement of the U.S. Geological Survey Science Strategy Planning Feedback Process  

Federal Register 2010, 2011, 2012, 2013

...the U.S. Geological Survey Science Strategy Planning Feedback...and Land Use Change, Core Science Systems, Ecosystems, Energy...Minerals, Environmental Health, Natural Hazards, and Water. This...usgs.gov/start_with_science. DATES: The comment...

2012-07-23

126

76 FR 13207 - Announcement of the U.S. Geological Survey Science Strategy Planning Feedback Process  

Federal Register 2010, 2011, 2012, 2013

...the U.S. Geological Survey Science Strategy Planning Feedback...and Land Use Change, Core Science Systems, Ecosystems, Energy...Minerals, Environmental Health, Natural Hazards, and Water. This...usgs.gov/start_with_science. DATES: The comment...

2011-03-10

127

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

128

Fundamental Issues in the Coalescence-Based Processing of Polymer Powders and Colloids.  

National Technical Information Service (NTIS)

The processing of polymer colloids occurs under the influence of internal surface forces and externally applied tractions. Internal surface forces result from molecular volume-to-volume and surface interactions. A formulation for the computation of surfac...

C. Argento A. Jagota S. Mazur

1996-01-01

129

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

130

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

131

Fundamental Properties of Organic Low-k Dielectrics Usable in the Cu Damascene Process  

NASA Astrophysics Data System (ADS)

The material parameters for organic low-k dielectrics usable in the damascene process were studied using two different types of polymers with similar low dielectric constants, namely, the PQ-600 thermoplastic polymer and the SiLK thermosetting polymer. The resistibility of these polymers in the damascene process was investigated through hard-mask (SiO2) deposition, etching and chemical mechanical polishing (CMP) processes using scanning probe microscopy (SPM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and a modified edge liftoff test (m-ELT). For the PQ-600 film, damage was observed in the deposition process and dissolution of the film occurred during chemical cleaning in the etching process. On the other hand, the SiLK film was combinable with the Cu damascene process and usable as an interlayer dielectric (ILD) in one-level Cu wiring. A high glass transition temperature (Tg) and chemical resistance resulting from the thermosetting structure are considered to be the essential properties required for the desired organic low-k dielectrics. In eddition, the electrical properies of the SiLK film were investigated using a one-level test element group (TEG) formed through a single Cu damascene process. The dielectric constant of the SiLK film extracted from the Cu damascene TEG compared with that of bulk SiO2 was reduced by 24%. The leakage current measured at 1 MV/cm between the adjoining Cu lines at the TEG pattern with a hard mask was 9.7× 10-10 A/cm2, and dielectric breakdown occurred at 5.5 MV/cm.

Nomura, Yutaka; Ota, Fumihiko; Kurino, Hiroyuki; Koyanagi, Mitsumasa

2005-11-01

132

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

133

Fundamentals and applications of a plasma-processing system based on electron-beam ionization  

NASA Astrophysics Data System (ADS)

Plasmas generated from moderate energy (2-5 keV) electron beams (e-beam) have unique, attractive characteristics that are ideal for materials processing applications. These plasmas possess low electron temperatures (<0.5 eV), variable plasma densities (109-1012 cm-3) with an improved control of plasma species generation, and perhaps most importantly, a direct scalability to processing areas exceeding one square meter. These characteristics are due to the plasma ionization being driven by the e-beam instead of an external electromagnetic field as used in conventional processing plasma sources. Theoretical and experimental system details are discussed in terms of plasma operating conditions applied to three different surface modification approaches: metal nitriding, negative ion etching, and polymer surface energy tailoring.

Leonhardt, D.; Walton, S. G.; Fernsler, R. F.

2007-05-01

134

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

135

A fundamental study on the mechanism of electrolytic in-process dressing (ELID) grinding  

Microsoft Academic Search

Demands for high quality surface finish, dimensional and form accuracy are required for optical surfaces and it is very difficult to achieve these using conventional grinding methods. Electrolytic in-process dressing (ELID) grinding is one new and efficient method that uses a metal-bonded diamond grinding wheel in order to achieve a mirror surface finish especially on hard and brittle materials. However,

H. S. Lim; K. Fathima; A. Senthil Kumar; M. Rahman

2002-01-01

136

Foundations of Physical Theory, I: Force and Energy. Physical Processes in Terrestrial and Aquatic Ecosystems, Fundamentals.  

ERIC Educational Resources Information Center

This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module is one of two units on the foundations of physical theory and the…

Pearson, Nolan E.

137

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

138

Education Policy-Planning Process: An Applied Framework. Fundamentals of Educational Planning 51.  

ERIC Educational Resources Information Center

This booklet provides an introduction to the educational policy-making process for both experienced and new planners. Policy is defined as decisions designed to guide future decisions or to initiate and guide the implementation of previous decisions. Case studies of Burkina Faso, Jordan, Peru, and Thailand show how educational policy has played…

Haddad, Wadi D.; Demsky, Terri

139

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

140

Lubrication-related residue as a fundamental process scaling limit to gravure printed electronics.  

PubMed

In gravure printing, excess ink is removed from a patterned plate or roll by wiping with a doctor blade, leaving a thin lubrication film in the nonpatterned area. Reduction of this lubrication film is critical for gravure printing of electronics, since the resulting residue can lower device performance or even catastrophically impact circuit yield. We report on experiments and quantitative analysis of lubrication films in a highly scaled gravure printing process. We investigate the effects of ink viscosity, wiping speed, loading force, blade stiffness and blade angle on the lubrication film, and further, use the resulting data to investigate the relevant lubrication regimes associated with wiping during gravure printing. Based on this analysis, we are able to posit the lubrication regime associated with wiping during gravure printing, provide insight into the ultimate limits of residue reduction, and, furthermore, are able to provide process guidelines and design rules to achieve these limits. PMID:24625096

Kitsomboonloha, Rungrot; Subramanian, Vivek

2014-04-01

141

Fundamental processes within natural and constructed wetland ecosystems: short-term versus long-term objectives  

Microsoft Academic Search

Abstract Use of wetland ecosystems,for water pollution control consists essentially of sustained induced disturbances as pollutants are loaded to complex,biological communities. Objectives are to maximize pollutant loading, incorporation, and retention while maintaining highest levels of community metabolism and minimal alteration of community,structure. Several basic processes are emphasized: (a) macrophyte productivity in relation to shoot:root ratios, and nutrient availability; (b) macrophyte

R. g. Wetzel

142

Geologic Maps  

NSDL National Science Digital Library

This web site provides an introduction to geologic maps. Topics covered include what is a geologic map, unique features of geologic maps, letter symbols, faults, and strike and dip. Users may click to view colored geologic maps, the geologic map of the United States and the geologic relief map of the United States.

Graymer, Russell

143

Investigation of the geologic setting and geomorphic processes that control the formation and preservation of precarious rock zones  

NASA Astrophysics Data System (ADS)

Zones of precariously balanced rocks have been used as negative indicators of previous strong ground motion in seismically active regions of Southern California and Nevada (e.g. Brune 1996). Understanding the geologic context and the geomorphic framework that control the formation and preservation of precarious rocks is essential to testing their fidelity for extreme ground motion analyses. In this study we assess the geologic settings and the geomorphic processes nested within them using precarious rock zones (Granite Dells, Texas Canyon, and Granite Pediment) in low-seismicity regions of Arizona and Southern California. The Granite Dells locality is a ~20 km2 Proterozoic granite field that is ~5 km from the Prescott Valley graben faults (<0.2 mm/yr of Quaternary slip). The Texas Canyon locality is a ~132 km2 Mesozoic granite field that is ~23 km from the Little Rincon Mountains fault (<0.2 mm/yr of Quaternary slip). The Granite Pediment locality is a ~12 km2 Mesozoic granite pediment located ~96 km from the eastern section of the Garlock fault (<5 mm/yr of Quaternary slip). Characterization of the geologic context of each site included assembling a digital geologic database for Arizona, Southern California, and southern Nevada. The geologic database was queried for granitic bodies and Quaternary deposits. Active faults were categorized by their Quaternary slip rates, and a 20 km zone of no precarious rocks was created around each active fault based on the field surveys of Brune (1996). Aerial photographs were used to map the spatial distribution and geometry of joint sets within each site. Ground surveys using hand-held GPS units and digital photography were conducted to document the characteristics (lithology, size, fragility, weathering characteristics) and spatial density of precariously balanced rocks. Morphometric analyses of digital elevation data may indicate if there is a slope or relief range which the precarious rocks are optimally produced and/or preserved.

Haddad, D.; Arrowsmith, R.

2008-12-01

144

Fundamental nonlinearities of the reactor-settler interaction in the activated sludge process.  

PubMed

The activated sludge process can be modelled by ordinary and partial differential equations for the biological reactors and secondary settlers, respectively. Because of the complexity of such a system, simulation models are most often used to investigate them. However, simulation models cannot give general rules on how to control a complex nonlinear process. For a reduced-order model with only two components, soluble substrate and particulate biomass, general results on steady-state solutions have recently been obtained, such as existence, uniqueness and stability of solutions. The aim of the present paper is to utilize those results to formulate some implications of practical importance. In particular, strategies are described for the manual control of the effluent substrate concentration subject to the constraint that the settler is maintained in normal operation (with a sludge blanket in the thickening zone) in steady state. Such strategies contain how the two control parameters, the recycle and waste volumetric flow ratios, should be chosen for any (steady-state) values of the input variables. PMID:22678197

Diehl, Stefan; Farås, Sebastian

2012-01-01

145

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

146

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

PubMed

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

2014-02-18

147

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.

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

2006-01-01

148

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

149

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

150

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

151

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

152

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

NASA Astrophysics Data System (ADS)

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.

Starr, Matthew B.; Wang, Xudong

2013-07-01

153

Exploratory cell research and fundamental processes study in solid state electrochemical cells  

SciTech Connect

Last year this program demonstrated that alternative to lithium had some merit on which to base new polymer electrolyte batteries and other electrochemical devices. We reported that Na, Zn, and Cu electrolytes have modest conductivities at 100{degree}C. Some preliminary cell cycling data were reported with V{sub 6}O{sub 13} insertion cathodes, and the successful cell cycling suggested that N{sup +}, Zn{sup +2} could be inserted and removed reversibly in the cathode material. Also, thin-film polymer cathodes were shown by impedance measurements to have three characteristic regions of behavior. Each region had different controlling processes with relaxation time constants that could be separated with careful manipulation of film thickness, morphology, and charging level. The present report gives results of the continuation of these studies. In particular, the sodium system was studied more intensively with conductivity measurements on sodium triflate in poly(ethyleneoxide)(PEO), and cell studies with V{sub 6}O{sub 13} and poly(pyrrole)(PPY) cathodes. The impedance work was concluded and several directions of new work in that area were identified. The insertion studies with single crystal V{sub 6}O{sub 13} were concluded on this program and transferred to NSF funding. 29 refs., 6 figs., 6 tabs.

Smyrl, W.H.; Owens, B.B.; White, H.S. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science)

1990-06-01

154

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.

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

2011-01-01

155

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.

Starr, Matthew B.; Wang, Xudong

2013-01-01

156

Fundamental studies on ultrasonic cavitation-assisted molten metal processing of A356-nanocomposites  

NASA Astrophysics Data System (ADS)

The usage of lightweight high-performance components is expected to increase significantly as automotive, military and aerospace industries are required to improve the energy efficiency and the performance of their products. A356, which is much lighter than steel, is an attractive replacement material. Therefore, it is of great interest to enhance its properties. There is strong evidence that the microstructure and mechanical properties can be considerably improved if nanoparticles are used as reinforcement to form metal-matrix-nano-composite (MMNC). Several recent studies revealed that ultrasonic vibration is highly efficient in dispersing nanoparticles into the melt and producing MMNC. In this thesis, a detailed analysis of the microstructure and mechanical properties is provided for an A356 alloy enhanced with Al2O 3 and SiC nanoparticles via ultrasonic processing. Each type of the nanoparticles was inserted into the A356 molten metal and dispersed by ultrasonic cavitation and acoustic streaming technology (UST) to avoid agglomeration or coalescence. The results showed that microstructures were greatly refined and with the addition of nanoparticles, tensile strength, yield strength and elongation increased significantly. SEM and EDS analyses were also performed to analyze the dispersion of nanoparticles in the A356 matrix. Since the ultrasonic energy is concentrated in a small region under the ultrasonic probe, it is difficult to ensure proper cavitation and acoustic streaming for efficient dispersion of the nanoparticles (especially in larger UST systems) without to determine the suitable ultrasonic parameters via modeling and simulation. Accordingly, another goal of this thesis was to develop well-controlled UST experiments that can be used in the development and validation of a recently developed UST modeling and simulation tool.

Liu, Xiaoda

157

Genome-wide binding of the orphan nuclear receptor TR4 suggests its general role in fundamental biological processes  

PubMed Central

Background The orphan nuclear receptor TR4 (human testicular receptor 4 or NR2C2) plays a pivotal role in a variety of biological and metabolic processes. With no known ligand and few known target genes, the mode of TR4 function was unclear. Results We report the first genome-wide identification and characterization of TR4 in vivo binding. Using chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq), we identified TR4 binding sites in 4 different human cell types and found that the majority of target genes were shared among different cells. TR4 target genes are involved in fundamental biological processes such as RNA metabolism and protein translation. In addition, we found that a subset of TR4 target genes exerts cell-type specific functions. Analysis of the TR4 binding sites revealed that less than 30% of the peaks from any of the cell types contained the DR1 motif previously derived from in vitro studies, suggesting that TR4 may be recruited to the genome via interaction with other proteins. A bioinformatics analysis of the TR4 binding sites predicted a cis regulatory module involving TR4 and ETS transcription factors. To test this prediction, we performed ChIP-seq for the ETS factor ELK4 and found that 30% of TR4 binding sites were also bound by ELK4. Motif analysis of the sites bound by both factors revealed a lack of the DR1 element, suggesting that TR4 binding at a subset of sites is facilitated through the ETS transcription factor ELK4. Further studies will be required to investigate the functional interdependence of these two factors. Conclusions Our data suggest that TR4 plays a pivotal role in fundamental biological processes across different cell types. In addition, the identification of cell type specific TR4 binding sites enables future studies of the pathways underlying TR4 action and its possible role in metabolic diseases.

2010-01-01

158

Role of geology in diamond project development  

NASA Astrophysics Data System (ADS)

For a mining operation to be successful, it is important to bring fundamental and applied science together. The mining engineer needs to understand the importance of geology, mineralogy and petrography, and how projects can benefit from the data collected during the exploration and pre-exploration stage. Geological scientists also need to understand the process of project development from the exploration stage through mine design and operation to mine closure. Kimberlite pipe or dyke emplacement, geology and petrology/mineralogy are three areas that illustrate how information obtained from the geological studies could directly influence the mining method selection and the project strategy and design. Kimberlite emplacement is one of the fundamental processes that rely on knowledge of the kimberlite body geology. Although the importance of the emplacement model is commonly recognized in the resource geology, mining engineers do not always appreciate its importance to the mine design. The knowledge of the orebody geometry, character of the contact zones, internal structures and distribution of inclusions could directly influence pit wall stability (thus strip ratio), underground mining method selection, dilution, treatability, and the dewatering strategy. Understanding the internal kimberlite geology mainly includes the geometry and character of individual phases, and the orientation and character of internal structures that transect the rock mass. For any mining method it is important to know "where the less and where the more competent rocks are located" to achieve stability. On the other hand, the detailed facies studies may not be important for the resource and mine design if the rock types have similar physical properties and diamond content. A good understanding of the kimberlite petrology and mineralogy could be crucial not only to the treatability (namely diamond damage and liberation), but also to the pit wall and underground excavation stability, support design, mine safety (mudrush risk assessment) and mine dewatering. There is no doubt that a better understanding of the kimberlite and country rock geology has a direct impact on the safety and economics of the mining operations. The process of mine design can start at the beginning of kimberlite discovery by incorporating the critical geological information without necessarily increasing the exploration budget. It is important to appreciate the usefulness of fundamental geological research and its impact on increased confidence in the mine design. Such studies should be viewed as worthwhile investments, not as cost items.

Jakubec, Jaroslav

2004-09-01

159

High-Speed Deflagration and Detonation: Fundamentals and Control. International Colloquium on Control and Detonation Processes Held in Moscow, Russia on July 4-7, 2000.  

National Technical Information Service (NTIS)

Twenty two papers on fundamentals of high-speed deflagrations and detonations written by international experts are assembled in this volume. The papers have been presented at the International Colloquium on Control of Detonation Processes held in Moscow, ...

A. A. Borisov D. W. Netzer G. D. Roy S. M. Frolov

2001-01-01

160

Titan's topography as a clue to geologic processes and landscape evolution  

NASA Astrophysics Data System (ADS)

Cassini has revealed a diversity of surface features on Titan rivaled by few bodies in the Solar System. Some of these features are readily identified: dunes, channels, lakes, seas, fresh impact craters, and mountains. Others are enigmatic and in some cases have sparked debate about their mode of origin. Given the limited resolution of the Cassini images, at best 300 m for synthetic aperture RADAR (SAR) images, it can be difficult to identify details that might confirm a particular mode of origin. Supplementing the images with topographic information provides an important and sometimes crucial clue to the origin and evolution of landforms. Topographic profiles from altimetry and SARTopo analysis of the images can shed light on simpler features (e.g., dunes) and led to the surprising conclusion that Titan's largest feature, Xanadu, is not elevated as had been supposed. For more complex structures, digital topographic models (DTMs) provide a full three-dimensional view. About 10% of Titan's surface has been imaged in stereo by RADAR, and we have produced DTMs of about 2% by analyzing these stereopairs. Analysis of the results within the Cassini RADAR team has shed light on a number of geologic problems: * Some putative volcanic features (e.g., the supposed dome Ganesa Macula and various diffuse surface flows) have been shown to lack the expected relief, greatly weakening the case for their volcanic origin. * Conversely, flows in Hotei Regio have been shown to tower over nearby fluvial channels, and those near Sotra Facula are associated with multiple edifices and caldera-like pits, strengthening the case for a volcanic origin. * Depths of the handful of definite impact craters measured so far range from Ganymede-like to nearly zero, and are statistically consistent with a process such as eolian deposition that would steadily reduce the crater depth rather than a process such as surface erosion that would tend to leave craters only partially filled. * Clustering of the small north-polar lakes at a few discrete levels, all of which are hundreds of meters above the major seas, suggests that these bodies of liquid are connected locally but not (over relevant timescales) regionally by subsurface flow. * Evidence for topographic "benches" at multiple levels around the seas suggests that the liquid level has fluctuated over time, perhaps as a result of inter-hemispheric transport of volatiles over multi-seasonal timescales. These examples come primarily from Titan's northern hemisphere and equatorial zone. Cassini's extended mission to date has yielded extensive coverage of the southern hemisphere that we have recently integrated into a global control network, allowing us to begin producing DTMs of multiple southern hemisphere sites with consistent absolute elevations. Of particular interest are apparent basins, for the most part empty of surface liquid, near the South Pole. Are the basin floors or possible shoreline features at consistent elevations? How do the depths and absolute elevations compare to Ontario Lacus and the other small lakes (including transient ones) in the south, and to the lakes and seas of the northern hemisphere? Topomapping now under way will help address these and other questions about the evolution of Titan's southern hemisphere and its volatile distribution over time.

Kirk, R. L.

2012-12-01

161

Digital processing of orbital radar data to enhance geologic structure - Examples from the Canadian Shield  

Microsoft Academic Search

Various digital enhancement techniques for SAR are compared using SIR-B and Seasat images of the Canadian Shield. The three best methods for enhancing geological structure were found to be: (1) a simple linear contrast stretch; (2) a mean or median low-pass filter to reduce speckle prior to edge enhancement or a K nearest-neighbor average to cosmetically reduce speckle; and (3)

Penny M. Masuoka; Jeff Harris; Paul D. Lowman Jr.; Herbert W. Blodget

1988-01-01

162

Syndepositional dissolution of calcium carbonate in neritic carbonate environments: geological recognition, processes, potential significance  

Microsoft Academic Search

Within carbonate sediments below tropical–subtropical oceanic surface waters, syndepositional “chemical” dissolution of CaCO3 driven by organic matter oxidation can modify substantially the textural, compositional and early diagenetic characteristics of the resulting rock.Main actuogeological evidence for “chemical” dissolution includes pore-water chemistry of carbonate sediments, and corrosion of bioclasts. Geological evidence includes taphonomic bias towards bioclasts of primary low-magnesium calcite, ghosts of

Diethard Sanders

2003-01-01

163

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

164

Fragmentation Analysis - Fundamental Processes.  

National Technical Information Service (NTIS)

To investigate the effect of energy on rock fragmentation, a drop test device was designed and constructed. Ninety specimens each of 3.0 to 3.5 inch size specimens of anorthosite and Wausau quartzite were fragmented in this device. Analysis of energy limi...

C. W. Schultz

1972-01-01

165

Fragmentation Analysis - Fundamental Processes.  

National Technical Information Service (NTIS)

To investigate the effect of energy on rock fragmentation, initial testing was carried out using a drop test device. A total of 180 specimens of Wausau quartzite and anorthosite of 3.0 to 3.5 inch size were fragmented in this device. An analysis of the fr...

L. S. Sundae D. I. Kurth C. W. Schultz

1973-01-01

166

Estimation of fundamental kinetic parameters of polyhydroxybutyrate fermentation process of Azohydromonas australica using statistical approach of media optimization.  

PubMed

Polyhydroxybutyrate or PHB is a biodegradable and biocompatible thermoplastic with many interesting applications in medicine, food packaging, and tissue engineering materials. The present study deals with the enhanced production of PHB by Azohydromonas australica using sucrose and the estimation of fundamental kinetic parameters of PHB fermentation process. The preliminary culture growth inhibition studies were followed by statistical optimization of medium recipe using response surface methodology to increase the PHB production. Later on batch cultivation in a 7-L bioreactor was attempted using optimum concentration of medium components (process variables) obtained from statistical design to identify the batch growth and product kinetics parameters of PHB fermentation. A. australica exhibited a maximum biomass and PHB concentration of 8.71 and 6.24 g/L, respectively in bioreactor with an overall PHB production rate of 0.75 g/h. Bioreactor cultivation studies demonstrated that the specific biomass and PHB yield on sucrose was 0.37 and 0.29 g/g, respectively. The kinetic parameters obtained in the present investigation would be used in the development of a batch kinetic mathematical model for PHB production which will serve as launching pad for further process optimization studies, e.g., design of several bioreactor cultivation strategies to further enhance the biopolymer production. PMID:22915234

Gahlawat, Geeta; Srivastava, Ashok K

2012-11-01

167

Digital processing of orbital radar data to enhance geologic structure - Examples from the Canadian Shield  

NASA Technical Reports Server (NTRS)

Various digital enhancement techniques for SAR are compared using SIR-B and Seasat images of the Canadian Shield. The three best methods for enhancing geological structure were found to be: (1) a simple linear contrast stretch; (2) a mean or median low-pass filter to reduce speckle prior to edge enhancement or a K nearest-neighbor average to cosmetically reduce speckle; and (3) a modification of the Moore-Waltz (1983) technique. Three look directions were coregistered and several means of data display were investigated as means of compensating for radar azimuth biasing.

Masuoka, Penny M.; Harris, Jeff; Lowman, Paul D., Jr.; Blodget, Herbert W.

1988-01-01

168

Ion-enhanced oxidation of aluminum as a fundamental surface process during target poisoning in reactive magnetron sputtering  

SciTech Connect

Plasma deposition of aluminum oxide by reactive magnetron sputtering (RMS) using an aluminum target and argon and oxygen as working gases is an important technological process. The undesired oxidation of the target itself, however, causes the so-called target poisoning, which leads to strong hysteresis effects during RMS operation. The oxidation occurs by chemisorption of oxygen atoms and molecules with a simultaneous ion bombardment being present. This heterogenous surface reaction is studied in a quantified particle beam experiment employing beams of oxygen molecules and argon ions impinging onto an aluminum-coated quartz microbalance. The oxidation and/or sputtering rates are measured with this microbalance and the resulting oxide layers are analyzed by x-ray photoelectron spectroscopy. The sticking coefficient of oxygen molecules is determined to 0.015 in the zero coverage limit. The sputtering yields of pure aluminum by argon ions are determined to 0.4, 0.62, and 0.8 at 200, 300, and 400 eV. The variation in the effective sticking coefficient and sputtering yield during the combined impact of argon ions and oxygen molecules is modeled with a set of rate equations. A good agreement is achieved if one postulates an ion-induced surface activation process, which facilitates oxygen chemisorption. This process may be identified with knock-on implantation of surface-bonded oxygen, with an electric-field-driven in-diffusion of oxygen or with an ion-enhanced surface activation process. Based on these fundamental processes, a robust set of balance equations is proposed to describe target poisoning effects in RMS.

Kuschel, Thomas; Keudell, Achim von [Research Group Reactive Plasmas, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

2010-05-15

169

U.S. Geological Survey coastal and marine geology research; recent highlights and achievements  

USGS Publications Warehouse

The USGS Coastal and Marine Geology Program has large-scale national and regional research projects that focus on environmental quality, geologic hazards, natural resources, and information transfer. This Circular highlights recent scientific findings of the program, which play a vital role in the USGS endeavor to understand human interactions with the natural environment and to determine how the fundamental geologic processes controlling the Earth work. The scientific knowledge acquired through USGS research and monitoring is critically needed by planners, government agencies, and the public. Effective communication of the results of this research will enable the USGS Coastal and Marine Geology Program to play an integral part in assisting the Nation in responding the pressing Earth science challenges of the 21st century.

Williams, S. Jeffress; Barnes, Peter W.; Prager, Ellen J.

2000-01-01

170

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

171

ASTER digital image processing for geological mapping: Examples from Neoproterozoic Allaqi-Heiani Suture, Egypt  

NASA Astrophysics Data System (ADS)

This dissertation constitutes three manuscripts summarizing efforts in developing effective algorithms for the analysis of the Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) data for geological mapping using the Neoproterozoic Allagi-Heiani Suture (AHS) in southern Egypt as a test site. The first manuscript presents statistical approach for the selection of ASTER bands to be used for Red-Green-Blue (RGB) color combination images. The Optimum Index Factor (OIF) and determinants techniques are proposed to rank all possible ASTER RGB color combinations for the western part of AHS. ASTER has three subsystems including Visible and Near Infra-Red (VNIR), Short Wave Infra-Red (SWIR), and Thermal Infra-Red (TIR). Hence, ASTER bands can be used in seven Electromagnetic Spectrum (EMS) regions combinations. These are VNIR only, SWIR only, TIR only, VNIR+SWIR, VNIR+TIR, SWIR+TIR, and VNIR+SWIR+TIR. The OIF and determinants results agree in four of the seven EMS regions combinations (VNIR only, SWIR only, TIR only, and VNIR+SWIR), but differ in three (VNIR+TIR, SWIR+TIR, and VNIR+SWIR+TIR). The second manuscript outlines an effective algorithm to spectrally separate ophiolite components in AHS and use these as markers to trace the continuity of geological structures. Principal component analysis (PCA), Fast Fourier Transform (FFT), and Redundant Wavelet Transform (RWT) are used to identify ophiolite components as well as Neoproterozoic ductile structures to trace along-strike continuation in AHS. This work helps trace structures along AHS and reveals structures that have not been identified before. Nappes identified in the west are traced into the central part of the suture allowing for subsequent modification by younger structures. The third manuscript outlines a methodology to quantitatively evaluate ASTER band-ratios that can be effectively used for thematic classification aimed at separating distinctive lithologies in AHS. The Within-Class Homogeneity Criteria (WHC) is proposed for the selection of specific band-ratios. The effectiveness of WHC is tested by using the classification correction evaluation curve to select fewer band-ratios. The accuracy of WHC is tested by comparing previously published geological map covering AHS with the WHC-based classification results and those based on all 14 ASTER bands and all 182 ASTER band-ratios. Commission and emission errors frequently occurred during traditional thematic classification are conquered by using WHC-based classification.

Ren, Dianwei

172

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.

173

Using Snow to Teach Geology.  

ERIC Educational Resources Information Center

A lesson plan, directed at middle school students and older, describes using snow to study the geological processes of solidification of molten material, sedimentation, and metamorphosis. Provides background information on these geological processes. (MCO)

Roth, Charles

1991-01-01

174

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

175

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

176

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.

Bodzin, Alec

2002-04-01

177

Geologic Maps  

NSDL National Science Digital Library

Geologic Maps are unique in that they show the distribution of geologic features on a landscape through specific symbols and colors. The United States Geological Survey's (USGS) site Geologic Maps provides visitors with a good introduction to these concepts, which include the unique features of a geologic map; the meaning of their lines, colors, and symbols; the location of faults; and more. Anyone working with geologic maps or just interested in learning a little about cartography or geology will find this site easy to explore and full of good information.

2000-01-01

178

Impact, and its implications for geology  

NASA Astrophysics Data System (ADS)

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.

179

Marine Geology of the Southwestern San Juan Islands: New Insights From Multibeam Imagery and Processed Aeromagnetic Data  

Microsoft Academic Search

The San Juan Islands, located in the seismically active northern Puget Sound, have a complicated and not yet fully understood geologic history. This study is among the first marine geologic mapping efforts within the San Juan Islands, filling an important gap in an otherwise well-studied region. Existing geologic and geophysical data were combined with interpretations of new multibeam bathymetry and

J. E. Tilden; H. G. Greene; R. J. Blakely

2004-01-01

180

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

National Technical Information Service (NTIS)

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...

H. Niu

1995-01-01

181

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.

Grosfils, Eric

182

Image Gallery for Geology  

NSDL National Science Digital Library

These images of geologic phenomena are used to supplement introductory geology classes at the University of North Carolina at Chapel Hill. The images are categorized under plutonic, volcanic and sedimentary rocks; structural geology; weathering; and coastlines. There are photographs of different kinds of volcanoes; lavas and pyroclastic rocks; volcanic hazards; different types of sedimentary rocks and sedimentary structures; folds and faults; beach processes; and barrier islands.

Glazner, Allen

183

Geochemical Processes During Geological Carbon Storage: Lessons from Natural Analogues and Field Experiments (Invited)  

NASA Astrophysics Data System (ADS)

The nature, rates and consequences of reactions between CO2-charged brines and reservoir and caprock minerals for the long-term fate of geological carbon stores are uncertain. At worst it has been suggested that acid carbonated brines might corrode migration pathways through caprocks and fault zones allowing CO2 to escape and transporting metal contaminants. However there is a growing body of data from short term injection experiments, and sites where natural CO2 has been stored or actively leaking for 100,000's of years or more, which shows that the acid fluids are rapidly neutralised by reaction with carbonate and Fe-oxyhydroxide minerals, that the fluids precipitate carbonate minerals in caprocks and along migration pathways, and that caprocks have remained impermeable over millions of years. Limited observations from small scale injection experiments suggest that the natural heterogeneities in rock formations cause extensive fingering of the injected CO2, markedly increasing the rates of CO2 dissolution into formation brines. The resultant acidity drives the dissolution of carbonates and Fe-oxyhydroxide minerals which buffers pH, but the more sluggish dissolution of silicate minerals over time scales of months or more drives subsequent re-precipitation of carbonate minerals. Dissolution of Fe-oxide grain coatings is important in stabilizing Fe-Mg-Ca carbonate minerals. Reaction rates slow over 2 to 5 orders-of-magnitude as equilibrium is approached and in the longer term are controlled by the kinetic balance between the thermodynamic understep of the dissolution reactions of primary Si-Al phases (e.g. feldspars and micas in sandstone reservoirs) and the overstep driving the precipitation of clay minerals. Reservoir mineralogy imposes a key control on the fluid-mineral reactions where immature continental sandstones contain much higher fractions of reactive feldspars and micas than mature marine quartz sands. The major conclusion from observations to date is that fluid-mineral reactions are initially fast, are important in buffering fluid compositions and may cause important beneficial changes to formation and caprock permeabilities. However much more needs to be learnt. Many of the inferences on mineral dissolution and precipitation reactions are derived from modal decomposition calculations based on changes in sampled fluid chemistry and these suffer ambiguities arising from the limited number of soluble cations present in stoichiometric proportions in minerals and from the uncertainties in mineral compositions. The reservoirs and caprocks in natural analogues contain an inadequately sampled and exploited record of the fluid-mineral reactions but deciphering this requires careful petrographic, mineralogical and geochemical work to distinguish the response to CO2-charged fluids from earlier diagenetic episodes.

Bickle, M. J.; Kampman, N.; Wigley, M.; Dubacq, B.

2013-12-01

184

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

185

Do geological or climatic processes drive speciation in dynamic archipelagos? The tempo and mode of diversification in Southeast Asian shrews.  

PubMed

Geological and climatic processes potentially alter speciation rates by generating and modifying barriers to dispersal. In Southeast Asia, two processes have substantially altered the distribution of land. Volcanic uplift produced many new islands during the Miocene-Pliocene and repeated sea level fluctuations during the Pleistocene resulted in intermittent land connections among islands. Each process represents a potential driver of diversification. We use a phylogenetic analysis of a group of Southeast Asian shrews (Crocidura) to examine geographic and temporal processes of diversification. In general, diversification has taken place in allopatry following the colonization of new areas. Sulawesi provides an exception, where we cannot reject within-island speciation for a clade of eight sympatric and syntopic species. We find only weak support for temporally declining diversification rates, implying that neither volcanic uplift nor sea level fluctuations had a strong effect on diversification rates. We suggest that dynamic archipelagos continually offer new opportunities for allopatric diversification, thereby sustaining high speciation rates over long periods of time, or Southeast Asian shrews represent an immature radiation on a density-dependent trajectory that has yet to fill geographic and ecological space. PMID:19500148

Esselstyn, Jacob A; Timm, Robert M; Brown, Rafe M

2009-10-01

186

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

187

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

NASA Astrophysics Data System (ADS)

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 ring-forming 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

188

Research Fundamentals  

NSDL National Science Digital Library

This activity is used in a Sociology class for undergraduate students. This activity helps students learn about research/data maniputlation volcabulary and teaches students about research fundamentals. This activity includes a glossary of terms, but there is no answer key. The best time to use this activity is before students begin research methods, or near the beginning of the course.

Combs, Charles

189

Exogenic Geological Processes as a Source of Formation of Bottom Silt in the Votkinskoe Reservoir  

Microsoft Academic Search

Experience shows that bottom silt accumulating on reservoir beds directly affects the occurrence of biological, chemical, and physical processes in the mineral substrate of the flooded river valley, in the water mass, and, in some cases, even in the low atmospheric layers [1]. Arriving from the outside and accumulating in the bowl of the reservoir the organomineral substance permanently changes

N. N. Nazarov

2002-01-01

190

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.

2009-05-21

191

Computer Simulation of Geologic Systems.  

National Technical Information Service (NTIS)

The Geologic Simulation Model (GSM) developed under the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) project at the Pacific Northwest Laboratory for the Department of Energy is a quasi-deterministic process-response model which simula...

M. G. Foley

1982-01-01

192

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

193

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.

Wagner, John

194

Radiometric dating in geology  

Microsoft Academic Search

The method of dating rocks and minerals is known as geochronology. Although in principle this term could be applied to estimation of relative ages according to traditional geological observation, it is nowadays usually restricted to the quantitative measurement of geological time using the constant-rate natural process of radioactive decay. 14C dating is a technique based on measuring the residual radioactivity

R J Pankhurst

1980-01-01

195

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.

2008-04-17

196

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

197

Compositional Data Analysis of Geological Variability and Process: A Case Study  

Microsoft Academic Search

Developments in the statistical analysis of compositional data over the last two decades have made possible a much deeper\\u000a exploration of the nature of variability and the possible processes associated with compositional data sets from many disciplines.\\u000a In this paper, we concentrate on geochemical data. First, we explain how hypotheses of compositional variability may be formulated\\u000a within the natural sample

Christopher W. Thomas; John Aitchison

2005-01-01

198

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

199

GEOLOGIC PROCESSES AFFECTING THE QUALITY OF THE UPPER FREEPORT COAL BED, WEST-CENTRAL PENNSYLVANIA.  

USGS Publications Warehouse

The number or types of origins of the components of a coal bed cannot be determined from its bulk composition. Minerals such as quartz, calcite, and pyrite as well as macerals such as vitrinite can originate from a variety of processes that result from different depositional conditions. The Upper Freeport coal bed was studied and characterized by sampling and analyzing its mappable subunits (facies) over a 120-sq mi area in west-central Pennsylvania. The study was based on field description of mine faces and description of X-ray radiographs of core. A geochemical model proposed for the origin of facies of the Upper Freeport coal bed is consistent with interpretations of modern peat formation resulting from the interaction of climate, plant types, rainfall, ground water geochemistry, nutrient supply, and sedimentation. This model provides a means to evaluate and predict more precisely the variability of a coal resource's quality.

Stanton, R. W.; Cecil, C. B.; Pierce, B. S.; Ruppert, L. F.; Dulong, F. T.

1985-01-01

200

Slope processes in weathered volcaniclastic rocks of the Camaldoli hill (Naples, Italy): Geomorphologic and Engineering-Geological aspects  

NASA Astrophysics Data System (ADS)

Following the geological study performed by Orsi et al. (this session), the main results of a geomorphologic and engineering-geological investigation of the stability conditions of the Camaldoli hill (urban area of Naples) are here presented. The Camaldoli hill, the highest peak of the Phlegraean Fields caldera (452 m asl), is characterized by relief energy of a few hundreds of meters, and by high slope gradients, which frequently reach the verticality. Low-order, structurally controlled channels drain the hillslopes; the development of stepped longitudinal profiles in the channels is related to the alternance of rocks and soils. The geological framework of the hill represent a further factor predisposing to mass movements and soil erosion. The Camaldoli hill is in fact characterized, as already highlighted by Orsi et al., by a basal sequence of jointed weak tuffs, overlain by some tens of metres of loose, unconsolidated pyroclastic terrains, ranging in age from about 12.000 and 4.000 yrs. BP. The latter deposits are generally weathered in their upper layers, as a consequence of interaction with decay agents and of past slope instabilities. Present-day morphodynamics of the hill is ruled by the occurrence of a variety of slope processes. Shallow landslides involve the weathered portion of the youngest pyroclastic products, showing features typical of slides or falls. Such events, which usually start in the upper reaches of the slope, may undergo different evolution, essentially controlled by the local slope morphology: (i) low-mobility soil slides-debris flows on open slopes; (ii) slides/falls evolving to hyperconcentrated flows along channels. The first processes have been seldom observed on open slopes, while the transition from slides/falls to hyperconcentrated flows along channels seems much more diffuse in the study area. The flows are generally fed, under intense to extreme rainfall events, by the re-mobilization of pre-existing landslide debris. The upper tuff formations (namely, the Neapolitan Yellow Tuff) are involved in falls and topple failures, which can detach volumes up to some tens of cubic metres, frequently reaching the lowest sectors of the slope, close to, if not within, the urbanized area. Eventually, accelerated soil erosion plays a major role in the open slopes, where evidences of sheet, rills and gullies have been surveyed. Joining the contribution of volcanologists and engineering-geologists, a tentative evaluation of the volumes susceptible to be mobilized by instability processes acting on the surficial, weathered cover of the loose pyroclastics was performed, adopting different methodologies. The so obtained results are compared and discussed in the paper: overall, they provide evidence of a widespread proneness to slope instability, which in turn may result into a serious threat to the diffuse settlements and infrastructures located at the Camaldoli’s foothill.

Calcaterra, D.; Coppin, D.; Palma, B.; Parise, M.; Orsi, G.; de Vita, S.; di Vito, M. A.

2003-04-01

201

Geology of the region of Guadalajara, Mexico, and its relationships with processes of subsidence  

NASA Astrophysics Data System (ADS)

The city of Guadalajara, Mexico, began an accelerated urban growth in early 1950. During a span of 25 years a large number of gullies were artificially filled, with the aim of incorporating new areas for urbanization, particularly in the areas north and west of the city. These gullies originally formed a complex dendritic-type system, whose evolution may be associated with faults or fracture zones whose current identification are only possible based on escarpments along the Canyon of the Rio Grande de Santiago (CRGS), north of Guadalajara. Reports of affectations documented in the 80's described subsidence in buildings and infrastructure, a process that has been continued during 2008. We present the results of work done in the CRGS, which is a tectonic erosive-depression with an average depth of 500 m and exhibits a sequence of volcanic and sedimentary deposits with rapid lateral facies changes. The stratigraphic column spans a 15 km-long section along the Matatlán-Arcediano road, and, from top to bottom contains: 1) Unconsolidated pumice and tuffs with an average thickness of 12 m; 2) basaltic lavas with average thickness of 60 m; 3) the San Gaspar ignimbrite; 4) fluvial- sedimentary deposits with a thickness of approximately 20 meters that include both sub-rounded and angular volcanic clasts, with sizes up to 0.15 m; 5) a thick sequence of ignimbrites and dacitic lavas. At a depth of 1200 m.a.s.l. in the town of Arcediano, the basal sequence is composed of dacites and andesites with interbedded pumice-rich ignimbrites with 10-20 m thickness. The Rio Grande de Santiago talweg to 1018 m.a.s.l. (apparently the base of the sequence) is formed by andesite lava. In the area of San Gaspar we identified oblique-normal left-lateral faults in lavas, with a strike 191° and a dip 89°. In the Colimilla dam, 1297 m.a.s.l., we observed normal faulting (strike 267° and dip 81°), with 20-30 m jumps with reference to a unit of tephra of 3-10 m thickness. The lavas in this site present deformation, the main shear being parallel to the Rio Verde. At the site of the San Gaspar river the faults have a strike of 285° and a dip of 83v and affect ignimbrites that overlie dacitic lavas. In the area of the Arcediano bridge the normal faulting has a strike 188v and dip of 75° in andesites, and in the pumice-rich ignimbrites a shear direction with strike of 92° and dip of 84° that is parallel to the Rio Verde. During the past two years we identified approximately 1100 cases of sinking with varying magnitude in the urban area of Guadalajara. Some of these can be grouped to form alignments that are oriented with the faults identified in the CRGS region. The process of subsidence can be controlled by structures that affect the pumice sequence laying under the city of Guadalajara, facilitating the movement of groundwater through areas of weakness, removing tuffs and pumice and creating voids that later collapse, affecting buildings and infrastructure in the city.

Suarez-Plascencia, C.; Delgado-Argote, L. A.; Nuñez-Cornu, F. J.; Sanchez, J. J.

2008-12-01

202

Thermohydrology of fractured geologic materials  

NASA Astrophysics Data System (ADS)

Thermohydrological and thermohydrochemical modeling as applied to the disposal of radioactive materials in a geologic repository is presented. Site hydrology, chemistry, and mineralogy were summarized and conceptual models of the fundamental system processes were developed. The numerical model TOUGH2 was used to complete computer simulations of thermohydrological processes in fractured, geologic media. Sensitivity studies investigating the impact of dimensionality and different conceptual models to represent fractures (ECM, DK, MINC) on thermohydrological response were developed. Sensitivity to parameter variation within a given conceptual model was also considered. The sensitivity of response was examined against thermohydrological metrics derived from the flow and redistribution of moisture. A simple thermohydrochemical model to investigate a three-process coupling (thermal-hydrological-chemical) was presented. The redistribution of chloride was evaluated because the chemical behavior is well known and defensible. In addition, it is very important to overall system performance. For all of the simulations completed, chloride was found to be extremely concentrated in the fluids that eventually return to the engineered barrier system. Chloride concentration and mass flux were increased from ambient by over a factor of 1000 for some simulations. Thermohydrology was found to have the potential to significantly alter chemistry from ambient conditions.

Esh, David Whittaker

1998-11-01

203

GWM: A Ground-Water Management Process for the U.S. Geological Survey Modular Ground-Water Model (MODFLOW-2000).  

National Technical Information Service (NTIS)

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 manag...

D. P. Ahlfeld P. M. Barlow A. E. Mulligan

2005-01-01

204

Hydrothermal reactions of agricultural and food processing wastes in sub- and supercritical water: a review of fundamentals, mechanisms, and state of research.  

PubMed

Hydrothermal (HT) reactions of agricultural and food-processing waste have been proposed as an alternative to conventional waste treatment technologies due to allowing several improvements in terms of process performance and energy and economical advantages, especially due to their great ability to process high moisture content biomass waste without prior dewatering. Complex structures of wastes and unique properties of water at higher temperatures and pressures enable a variety of physical-chemical reactions and a wide spectra of products. This paper's aim is to give extensive information about the fundamentals and mechanisms of HT reactions and provide state of the research of agri-food waste HT conversion. PMID:23848589

Pavlovi?, Irena; Knez, Željko; Škerget, Mojca

2013-08-28

205

Isotope Tracer Studies of Diffusion in Sillicates and of Geological Transport Processes Using Actinide Elements  

SciTech Connect

The objectives were directed toward understanding the transport of chemical species in nature, with particular emphasis on aqueous transport in solution, in colloids, and on particles. Major improvements in measuring ultra-low concentrations of rare elements were achieved. We focused on two areas of studies: (1) Field, laboratory, and theoretical studies of the transport and deposition of U, Th isotopes and their daughter products in natural systems; and (2) Study of calcium isotope fractionation effects in marine carbonates and in carbonates precipitated in the laboratory, under controlled temperature, pH, and rates of precipitation. A major study of isotopic fractionation of Ca during calcite growth from solution has been completed and published. It was found that the isotopic shifts widely reported in the literature and attributed to biological processes are in fact due to a small equilibrium fractionation factor that is suppressed by supersaturation of the solution. These effects were demonstrated in the laboratory and with consideration of the solution conditions in natural systems, where [Ca{sup 2+}] >> [CO{sub 3}{sup 2-}] + [HCO{sub 3}{sup -}]. The controlling rate is not the diffusion of Ca, as was earlier proposed, but rather the rate of supply of [CO{sub 3}{sup 2-}] ions to the interface. This now opens the issues of isotopic fractionation of many elements to a more physical-chemical approach. The isotopic composition of Ca {Delta}({sup 44}Ca/{sup 40}Ca) in calcite crystals has been determined relative to that in the parent solutions by TIMS using a double spike. Solutions were exposed to an atmosphere of NH{sub 3} and CO{sub 2}, provided by the decomposition of (NH4)2CO3. Alkalinity, pH, and concentrations of CO{sub 3}{sup 2-}, HCO{sub 3}{sup -}, and CO{sub 2} in solution were determined. The procedures permitted us to determine {Delta}({sup 44}Ca/{sup 40}Ca) over a range of pH conditions, with the associated ranges of alkalinity. Two solutions with greatly different Ca concentrations were used, but, in all cases, the condition [Ca] >> [CO{sub 3}{sup 2-}] was met. A wide range in {Delta}({sup 44}Ca/{sup 40}Ca) was found for the calcite crystals, extending from 0.04 {+-} 0.13 to -1.34 {+-} 0.15 {per_thousand}, generally anticorrelating with the amount of Ca removed from the solution. The results show that {Delta}({sup 44}Ca/{sup 40}Ca) is a linear function of the saturation state of the solution with respect to calcite ({Omega}). The two parameters are very well correlated over a wide range in {Omega} for each solution with a given [Ca]. Solutions, which were vigorously stirred, showed a much smaller range in {Delta}({sup 44}Ca/{sup 40}Ca) and gave values of -0.42 {+-} 0.14 {per_thousand}, with the largest effect at low {Omega}. It is concluded that the diffusive flow of CO{sub 3}{sup 2-} into the immediate neighborhood of the crystal-solution interface is the rate-controlling mechanism and that diffusive transport of Ca{sup 2+} is not a significant factor. The data are simply explained by the assumptions that: (a) the immediate interface of the crystal and the solution is at equilibrium with {Delta}({sup 44}Ca/{sup 40}Ca) {approx} -1.5 {+-} 0.25 {per_thousand}, and (b) diffusive inflow of CO{sub 3}{sup 2-} causes supersaturation, thus precipitating Ca from the regions, exterior to the narrow zone of equilibrium. We consider this model to be a plausible explanation of the available data reported in the literature. The well-resolved but small and regular isotope fractionation shifts in Ca are thus not related to the diffusion of very large hydrated Ca complexes, but rather due to the ready availability of Ca in the general neighborhood of the crystal solution interface. The largest isotopic shift which occurs is a small equilibrium effect which is then subdued by supersaturation precipitation for solutions where [Ca{sup 2+}] >> [CO{sub 3}{sup 2-}] + [HCO{sub 3}{sup -}]. It is shown that there is a clear temperature dependence of the net isotopic shifts, which is simply due to changes in {Omega}

Wasserburg, Gerald J

2008-07-31

206

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

207

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

208

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.

209

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

210

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

211

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

212

Geologic Time.  

ERIC Educational Resources Information Center

One of a series of general interest publications on science topics, the booklet provides those interested in geologic time with an introduction to the subject. Separate sections discuss the relative time scale, major divisions in geologic time, index fossils used as guides for telling the age of rocks, the atomic scale, and the age of the earth.…

Newman, William L.

213

Geology of caves  

USGS Publications Warehouse

A cave is a natural opening in the ground extending beyond the zone of light and large enough to permit the entry of man. Occurring in a wide variety of rock types and caused by widely differing geological processes, caves range in size from single small rooms to intercorinecting passages many miles long. The scientific study of caves is called speleology (from the Greek words spelaion for cave and logos for study). It is a composite science based on geology, hydrology, biology, and archaeology, and thus holds special interest for earth scientists of the U.S. Geological Survey.

Morgan, I. M., Davies, W. E.

1991-01-01

214

Geology of Mars  

NSDL National Science Digital Library

This website provides information about the six geological processes that are either currently operating on Mars or have operated during Martian history. These include the aeolian, cratering, hydro, landslides, tectonic, and volcanic processes. Example images of the results of these processes are provided.

Hsui, Albert T.

2004-07-14

215

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

216

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

2010-09-03

217

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.

Newman, William L.

1997-01-01

218

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

219

Side-scan sonar along the north wall of the Hess Deep Rift: Processing, texture analysis, and geologic ground truth on an oceanic escarpment  

NASA Astrophysics Data System (ADS)

Side-scan sonar data collected along the steep, faulted north wall of the Hess Deep Rift provide images of a cross section of the upper oceanic crust. These data are integrated with ground truth from the submersible Alvin and the Argo II remotely operated vehicle (ROV) to evaluate faulting and mass wasting associated with the opening of the rift and to help trace geologic contacts between widely spaced dives and ROV surveys. Initial shipboard and subsequently processed data show excellent backscatter returns with well-imaged textures and distinctive patterns corresponding to specific rock units and surficial deposits. Four backscatter textures are widely developed and found to correspond to outcrops of basaltic lavas, outcrops of sheeted dikes and gabbroic rocks, surficial talus and rubble deposits, and pelagic sedimentary material. Using test areas identified by Alvin dives, the side-scan sonar data were processed to automatically classify the backscatter returns in terms of major rock units. The resultant processed image is used for further manual and computer-aided classification of the scarp geology. These techniques are evaluated for mapping the geology in rugged terrains similar to the steep walls of Hess Deep Rift.

Hurst, Stephen D.; Karson, Jeffrey A.

2004-02-01

220

Geological Mediation of Hydrologic Process, Channel Morphology and Resultant Planform Response to Closure of Dwinnell Dam, Shasta River, California  

Microsoft Academic Search

Alluvial channel morphologies depend on hydrologic regime conditions defined by the magnitude, frequency, timing and variability of measured streamflows. Because regime conditions vary in part with the spatial distribution of underlying geology, the character of downstream channel form response to fluvial impoundment is mediated by not only changes to streamflow and sediment transport characteristics imparted by dam operations, but also

A. L. Nichols; J. F. Mount

2008-01-01

221

Geology 201: Non-linear processes in geofluids or Why does the Earth look the way it does?  

NASA Astrophysics Data System (ADS)

Many patterns we observe on the Earth’s surface are a result of fluid transport, fluxes, and phase changes. Coastlines, drainage networks, river deltas, types of rock deformation and the driving mechanism for plate tectonics all result from fluid flows exhibiting complex behavior. Currently, undergraduate students often do not have conceptual frameworks necessary for understanding non-linear systems. Their prior experiences have often emphasized linear and non-directional relationships, but most physical systems are inherently nonlinear in nature. We have found it difficult to explain ideas such as feedbacks, hysteresis, and phase transitions to students without prior exposure to complex system behavior. Here we will present a curriculum designed for sophomore-level undergraduates that will use concepts of flow to explain origin of the features we see on the Earth’s surface, while simultaneously teaching fundamental properties of complex-system behavior. Example features will come from tectonics, mantle convection, geomorphology, and hydrology. We will provide an outline of course materials where students will first be exposed to physical and conceptual models of non-linear behavior and then follow up with understanding the equations governing these processes. Examples: Rock rheologies using food analogies and then exploring material constitutive equations, stream channel avulsion using a classroom teaching flume, then a one-dimensional model of bifurcating flow in a channel. We chose the sophomore level specifically so students are introduced early in their academic career and thus have the conceptual frameworks and quantitative skills necessary to work with complex systems as they advance to upper level courses. Learning goals for the course we present will include the ability to recognize non-linear behavior, and the development of a level of comfort with these concepts.

Orr, C. H.; Cooper, C. M.

2010-12-01

222

InAs Based Quantum Dots for Quantum Information Processing:. from Fundamental Physics to 'plug and Play' Devices  

NASA Astrophysics Data System (ADS)

Semiconductor quantum dots have attracted much interest in implementing solid-state quantum information processing. Using InAs based quantum dots, we demonstrate quantum coupling between two stacked quantum dot molecules in electroluminescence, controlling Stark shifts of single quantum dots in electroluminescence, and 'plug and play' single photon emission at telecommunication wavelengths.

Xu, Xiulai; Andreev, Aleksey; Brossard, Frederic; Hammura, Kiyotaka; Williams, David

2009-06-01

223

InAs Based Quantum Dots for Quantum Information Processing:. from Fundamental Physics to 'plug and Play' Devices  

Microsoft Academic Search

Semiconductor quantum dots have attracted much interest in implementing solid-state quantum information processing. Using InAs based quantum dots, we demonstrate quantum coupling between two stacked quantum dot molecules in electroluminescence, controlling Stark shifts of single quantum dots in electroluminescence, and 'plug and play' single photon emission at telecommunication wavelengths.

Xiulai Xu; Aleksey Andreev; Frederic Brossard; Kiyotaka Hammura; David Williams

2009-01-01

224

Latest research on fundamental studies of CO 2 capture process technologies at the international test centre for CO 2 capture  

Microsoft Academic Search

The ultimate goal of this R & D program is to develop better and more effective CO2 separation processes that can be used to recover CO2 from industrial sources such as fossil fuel-fired power stations, coal gasification plants, petroleum refinery facilities and hydrogen production units at the lowest possible capital and operating costs. This paper presents the latest research results

Raphael Idem; Paitoon Tontiwachwuthikul; Don Gelowitz; Malcolm Wilson

2011-01-01

225

Effects of Direct Instruction and Environmentally Designed Instruction on the Process and Product Characteristics of a Fundamental Skill  

Microsoft Academic Search

This study investigated the effects of direct instruction and an environmentally designed instructional strategy on the product and process characteristics of kindergarten and second grade children in the standing long jump. One hundred and sixteen kindergarten and second grade students participated in the study and were assigned to a 3-day, 60-trial, direct instruction group or a 3-day, 60-trial, environmentally designed

Terry Sweeting; Judith E. Rink

1999-01-01

226

A fundamental investigation of the ionization process in xenon undergoing a normal shock wave compression in a shock tube  

Microsoft Academic Search

The ionization process in xenon has been studied by measurements of the atomic line radiation histories. Visible line radiation measurements of three atomic line transitions resulted in the measurement of time resolved bound electron temperature. No conclusion can be drawn with regard to the non-Boltzmann behavior of the bound states due to the inaccuracies in the reported transition probabilities. Resonance

R. A. Golobic

1975-01-01

227

Study of fundamental processes affecting the structure of the cathode zone of nitrogen\\/titanium dc discharge  

Microsoft Academic Search

Processes affecting the emission of the cathode zone plasma of a N2 \\/Ti dc discharge were studied experimentally and theoretically. Light maxima occurring at the negative glow head (maximum II) are due to the electron-molecule excitation. Emission characteristics of this region, space distributions of lighting, dependence of the line intensity (I ) on the gas pressure (p ) and current

Z. Wronski

2000-01-01

228

Fundamental processes in the expansion, energization, and coupling of single- and multi-Ion plasmas in space: Laboratory simulation experiments  

NASA Technical Reports Server (NTRS)

We have conducted a laboratory investigation into the physics of plasma expansions and their associated energization processes. We studied single- and multi-ion plasma processes in self-expansions, and included light and heavy ions and heavy/light mixtures to encompass the phenomenological regimes of the solar and polar winds and the AMPTE and CRRES chemical release programs. The laboratory experiments provided spatially-distributed time-dependent measurements of total plasma density, temperature, and density fluctuation power spectra with the data confirming the long-theorized electron energization process in an expanding cloud - a result that was impossible to determine in spaceborne experiments (as e.g., in the CRRES program). These results provided the missing link in previous laboratory and spaceborne programs. confirming important elements in our understanding of such solar-terrestrial processes as manifested in expanding plasmas in the solar wind (e.g., CMES) and in ionospheric outflow in plasmaspheric fluctuate refilling after a storm. The energization signatures were seen in an entire series of runs that varied the ion species (Ar', Xe', Kr' and Ne'), and correlative studies included spectral analyses of electrostatic waves collocated with the energized electron distributions. In all cases wave energies were most intense during the times in which the suprathermal populations were present, with wave intensity increasing with the intensity of the suprathermal electron population. This is consistent with theoretical expectations wherein the energization process is directly attributable to wave particle interactions. No resonance conditions were observed, in an overall framework in which the general wave characteristics were broadband with power decreasing with increasing frequency.

Szuszczewicz, E. P.; Bateman, T. T.

1996-01-01

229

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

230

Improving the Fundamental Understanding of Regional Seismic Signal Processing with a Unique Western U.S. Dataset  

SciTech Connect

This project has built a unique historic database of regional distance nuclear explosion, earthquake, and mine-related digital broadband seismograms for the western United States (US). The emphasis is on data from Lawrence Livermore National Laboratory (LLNL)-managed stations MNA, ELK, KNB and LAC that recorded many nuclear tests and nearby earthquakes in broadband digital form since 1980, along with a small number of earlier events that were digitized from tapes. Through the generous cooperation of Sandia National Laboratory (SNL) we have also included waveforms from their Leo Brady network (BMN, DWN, LDS, NEL,TON). In addition we include data from other open broadband stations in the western US with long operating histories and/or ties to the International Monitoring System (IMS) (e.g. PFO, YKA, CMB, NEW, DUG, ANMO, TUC). These waveforms are associated with a reconciled catalog of events and station response information to facilitate analysis. The goal is to create a high-quality database that can be used in the future to analyze fundamental regional monitoring issues such as detection, location, magnitude, and discrimination. In the first stage of the project, we collected six different regional network catalogs from the University of Nevada, Reno (UNR), to provide accurate independent location information for events on the Nevada Test Site (NTS) and in the surrounding region. We have used National Nuclear Security Administration (NNSA)-developed software to reconcile these catalogs with each other and to incorporate them into a set of larger continental scale (CNSS, see http://www.cnss.org; USGS mining catalog compiled by Jim Dewey) and global scale (PDE, REB, ISC) catalogs. Finally, we incorporate the best catalogs of NTS nuclear event locations and source properties (Springer et al. 2002). The result is a single catalog of preferred origins, source information, and station information. Concurrently, we collected continuous seismic data from open stations and recovered and reformatted old event segmented data from the LLNL and SNL managed stations for past nuclear tests and earthquakes. We then used the preferred origin catalog to extract waveforms from continuous data and associate event segmented waveforms within the database. The result is a well-organized regional western US dataset with hundreds of nuclear tests, thousands of mining explosions and hundreds of thousands of earthquakes. In the second stage of the project we have chosen a subset of approximately 125 events that are well located and cover a range of magnitudes, source types, and locations. Ms. Flori Ryall, an experienced seismic analyst is reviewing this dataset. She is picking all arrival onsets with quantitative uncertainties and making note of data problems (timing errors, glitches, dropouts) and issues. The resulting arrivals and comments will then be loaded into the database for future researcher use. During the summer of 2003 we will be carrying out some analysis and quality control on this subset. It is anticipated that this set of consistently picked, independently located data will provide an effective test set for regional sparse station location algorithms. In addition, because the set will include nuclear tests, earthquakes, and mine-related events, each with related source parameters, it will provide a valuable test set for regional discrimination and magnitude estimation as well. A final relational database of these approximately 125 events in the high quality subset will be put onto a CD-ROM and distributed for other researchers to use in benchmarking regional algorithms after the conclusion of the project.

Walter, W R; Smith, K; O'Boyle, J; Hauk, T F; Ryall, F; Ruppert, S D; Myers, S C; Anderson, M; Dodge, D A

2003-07-18

231

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

232

Geologic Map and Eruptive History of Veniaminof Volcano Record Aleutian Arc Processing of Mantle-Derived Melts  

Microsoft Academic Search

Mount Veniaminof, one of the largest volcanoes in the Aleutian arc, has a basal diameter of ~40 km, a volume of ~350 km3, an 8-km-diameter ice-filled caldera, and an active intracaldera cone. The geology of this tholeiitic basalt-to-dacite volcano has been mapped at 1:50,000 scale. Over 100 Quaternary volcanic map units are characterized by 600 chemical analyses of rocks and

C. R. Bacon; T. W. Sisson; A. T. Calvert; C. J. Nye

2009-01-01

233

Structural Geology  

NASA Astrophysics Data System (ADS)

Structural geology and continental tectonics were ushered in to the modern quantitative age of geosciences with the arrival of the global plate tectonics paradigm (circa 1968), derived using new data from the oceans' depths, and John Ramsay's 1967 seminal work, Folding and Fracturing of Rocks. Fossen is to be applauded for crafting a unique, high-caliber, and accessible undergraduate textbook on structural geology that faithfully reflects this advance and the subsequent evolution of the discipline. This well-written text draws on Fossen's wealth of professional experience, including his broad and diverse academic research and experience in the petroleum industry. This book is beautifully illustrated, with excellent original color diagrams and with impressive color field photographs that are all keyed to locations and placed into geologic context.

Weber, John; Frankel, Kurt L.

2011-05-01

234

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.

235

Geologic Explorations  

NSDL National Science Digital Library

One of the latest offerings from the North Carolina State University's Web site Science Junction (last mentioned in the November 25, 1998 Scout Report) is the Geologic Explorations page. By clicking on the respective coordinates of each location, users can explore twelve areas in the western United States with 360-degree panoramic QuickTime movies and digital photography. Set up as a type of lesson for students, the main page suggests paying close attention to the unique geologic features and gives a few questions to answer about each area. The site is very easy to use and provides some breathtaking vistas of some of the most beautiful areas of the US.

Bodzin, Alec M.

2001-01-01

236

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

237

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

238

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

239

Fundamentals of System Dynamics  

Microsoft Academic Search

\\u000a Unified methods of modeling physical systems are based on the idea that the storage, transmission, and transformation of power\\u000a and energy among system components and between a system and its surroundings are the fundamental processes underlying a system’s\\u000a dynamic behavior. Wellstead [W3] states the idea succinctly:\\u000a \\u000a \\u000a A physical system can be thought of as operating upon a pair of variables

Richard A. Layton

240

Spatial distribution of seafloor bio-geological and geochemical processes as proxies of fluid flux regime and evolution of a carbonate/hydrates mound, northern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

Woolsey Mound, a carbonate/hydrate complex of cold seeps, vents, and seafloor pockmarks in Mississippi Canyon Block 118, is the site of the Gulf of Mexico Hydrates Research Consortium's (GOMHRC) multi-sensor, multi-disciplinary, permanent seafloor observatory. In preparation for installing the observatory, the site has been studied through geophysical, biological, geological, and geochemical surveys. By integrating high-resolution, swath bathymetry, acoustic imagery, seafloor video, and shallow geological samples in a morpho-bio-geological model, we have identified a complex mound structure consisting of three main crater complexes: southeast, northwest, and southwest. Each crater complex is associated with a distinct fault. The crater complexes exhibit differences in morphology, bathymetric relief, exposed hydrates, fluid venting, sediment accumulation rates, sediment diagenesis, and biological community patterns. Spatial distribution of these attributes suggests that the complexes represent three different fluid flux regimes: the southeast complex seems to be an extinct or quiescent vent; the northwest complex exhibits young, vigorous activity; and the southwest complex is a mature, fully open vent. Geochemical evidence from pore-water gradients corroborates this model suggesting that upward fluid flux waxes and wanes over time and that microbial activity is sensitive to such change. Sulfate and methane concentrations show that microbial activity is patchy in distribution and is typically higher within the northwest and southwest complexes, but is diminished significantly over the southeast complex. Biological community composition corroborates the presence of distinct conditions at the three crater complexes. The fact that three different fluid flux regimes coexist within a single mound complex confirms the dynamic nature of the plumbing system that discharges gases into bottom water. Furthermore, the spatial distribution of bio-geological processes appears to be a valid indicator of multiple fluid flux regimes that coexist at the mound.

Macelloni, Leonardo; Brunner, Charlotte A.; Caruso, Simona; Lutken, Carol B.; D'Emidio, Marco; Lapham, Laura L.

2013-04-01

241

Sediment Studies Refute EIS Hypothesis, While Most Fundamental Process Questions Remain Unanswered: An Update on Experiments in Grand Canyon  

NASA Astrophysics Data System (ADS)

For three decades, sediment researchers have pondered the question of whether or not operations at Glen Canyon Dam could be adjusted to maintain downstream sand resources in Grand Canyon. Prior to the era when managed floods were proposed as a strategy to conserve sand inputs below the dam, Laursen et al. (1976) concluded that erosion of sandbars below the dam would be an inevitable, yet protracted post-dam process. Despite this earliest conclusion, the operational strategy for sandbar maintenance since 1996, has been based on two hypotheses: first, much of the sand introduced by tributaries downstream from the dam can accumulate in the channel over multiple years under operations associated with average-to-below average hydrology; and second, controlled floods can move that accumulated sand from the channel bed to shorelines, thereby rebuilding bars in a sustainable manner. Recent work has shown that the first hypothesis is false (Rubin et al., 2002). High resolution data for the ecosystem sand mass balance between 1999 and 2004, indicate no accumulation of tributary sand inputs in the main channel, despite a drought resulting in minimum annual release volumes from 2000 through 2004. Sandbar data also indicate that erosion has not been mitigated by re-operation strategies since 1991. On the basis of these data, researchers have again identified uncertainty regarding a flow strategy that will result in sustainable sandbars. If a successful flow strategy can not be devised, then managers may have to choose between abandoning sandbar restoration objectives, or pursuing sediment augmentation. Experimental fluctuating-flow treatments are also being evaluated for their potential to limit populations of introduced rainbow trout, yet these options are already known to increase sand export. While many institutional barriers to large-scale sediment experiments in Grand Canyon have recently been bridged through a science-based, adaptive management approach, protracted drought throughout the Upper Colorado River Basin now poses a natural barrier to testing the key sediment hypothesis. Downstream sand production from the Paria River remains at its lowest level in 80 years, while water storage in Lake Powell approaches 40 percent of capacity. As scientists wait out delays in sediment experimentation forced by the current drought, managers have already approved limited sediment augmentation feasibility studies aimed at identifying options for managing physical habitats. With regard to conventional thinking about regulation and management of natural hydrologic systems, some important lessons may be learned from the current situation. Rubin, D.M., Topping, D.J., Schmidt, J.C., Hazel, J., Kaplinski, M. and Melis, T.S., 2002, Recent Sediment Studies Refute Glen Canyon Dam EIS Hypothesis: Eos, vol. 83, no. 25, p. 273-278. Laursen, E.M., Ince, S. and Pollack, J., 1976, On Sediment Transport Through the Grand Canyon, Proceedings of the 3rd Federal Interagency Sedimentation Conference, Denver, CO, vol. 1, p. 4-76 - 4-87.

Melis, T. S.; Topping, D. J.; Wright, S. A.; Rubin, D. M.; Schmidt, J. C.; Hazel, J. E.; Kaplinski, M. A.; Parnell, R. A.

2004-12-01

242

Geology Fieldnotes  

NSDL National Science Digital Library

This National Park Service (NPS) site delivers a brief description of the geology of the Black Hills National Park. Links to park maps, a photo album, books, videos, CDs, and a searchable data base of research needs that have been identified by the National Park Service are included. General information about the park's education and interpretive programs are also abailable.

National Park Services (NPS)

243

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.

244

Geologic Time.  

ERIC Educational Resources Information Center

Discusses the historical development of the concept of geologic time. Develops the topic by using the major discoveries of geologists, beginning with Steno and following through to the discovery and use of radiometric dating. An extensive reference list is provided. (JM)

Albritton, Claude C., Jr.

1984-01-01

245

The preparation of illustrations for reports of the United States Geological survey : with brief descriptions of processes of reproduction  

USGS Publications Warehouse

There has been an obvious need in the Geological Survey o£ a paper devoted wholly to illustrations. No complete paper on the character, use, and mode of preparation of illustration has been published by the Survey, though brief suggestions concerning certain features of their use have been printed in connection wit other suggestions pertaining to publications. The present paper includes matter which it is hoped will be of service to authors in their work of making up original drafts of illustrations and to drafsmen who are using these originals in preparing more finished drawing but it is not a technical treatise on drafting.

Ridgway, John L.

1920-01-01

246

Uniform asymptotic expansion of a class of generalized Bessel functions occurring in the study of fundamental scattering processes in intense laser fields  

NASA Astrophysics Data System (ADS)

Using the method of Bleistein and of Ursell, a uniform asymptotic expansion for an important class of so-called generalized Bessel functions is derived, which permits a fast and efficient evaluation of these functions in the interesting domain of large values of their parameters where conventional methods fail. With the help of this asymptotic representation, a whole number of cross sections that have been given in the literature in terms of generalized Bessel functions for a variety of fundamental scattering processes in intense linearly polarized plane-wave laser fields can now be converted into actual numbers, thus permitting a quantitative assessment of the investigated effects at a given intensity of the applied laser field.

Leubner, C.

1981-06-01

247

CPEP: Fundamental Particles and Interactions  

NSDL National Science Digital Library

This chart shows the fundamental particles and their interactions. Included in the chart is information on the structure of the atom, baryons, mesons, fermions, and bosons. Additional sections are devoted to particle processes and unsolved mysteries.

Project, Contemporary P.

2008-11-01

248

Geology of Mojave National Preserve  

NSDL National Science Digital Library

This website of the United States Geological Survey (USGS) and the National Park Service (NPS) highlights the geology of the Mojave National Preserve in California. It includes a field trip describing areas of interest at the preserve, as well as a geologic time scale describing the history and development of this area. Processes that shaped this region include volcanism, tectonics, faulting, erosion, deposition, spreading, intrusions, and glaciation. There is a geologic map of the area with units and a legend, and links to maps and technical papers.

249

Fundamental Hypothesis of Hunt Processes.  

National Technical Information Service (NTIS)

New hypotheses involving predictable time and moderate Markov property are introduced and their relations to the Hunt-hypotheses are investigated. An equation connecting the strict past field and present state with the usual (F sub T) is given. (Author)

K. L. Chung

1972-01-01

250

The geology of Venus  

NASA Astrophysics Data System (ADS)

This paper summarizes the emerging picture of the surface of Venus provided by high-resolution earth-based radar telescopes and orbital radar altimetry and imaging systems. The nature and significance of the geological processes operating there are considered. The types of information needed to complete the picture are addressed.

Basilevsky, A. T.; Head, J. W.

251

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.

252

Cold seeps in the eastern Mediterranean a quantitative geological-biological-chemical investigation of causes, processes and implications- a preliminary seismic study  

NASA Astrophysics Data System (ADS)

Cold seepage of gas/water from the seafloor is one of the most important indications of active processes occurring in the subsurface of continental margins. The location and development of these seeps is, among other things, associated with mass sedimentary transport, resulting from slope failure (e.g. submarine landslides). Studies have shown that endemic ecological systems tend to develop in the shallow subsurface and seafloor near these sites, whose existence is directly related to utilization of the escaping gas. A large and unknown part of the carbon cycle is connected to the reduction and release of methane to the water column. However a precise evaluation of the fraction that eventually reaches the atmosphere as an important greenhouse gas is unknown. During the past few years a number of studies around the world have focused on the combination of geological, biological and chemical aspects of cold seeps. Despite this, many questions still remain unanswered, such as the geological mechanisms generating the seeps, the chemical composition of the seeps, which biological ecosystems base their existence on the seeps and how microbiological process in the subsurface effect the composition and rate of gas release. The eastern Mediterranean basin is one of the most interesting and least studied regions as far as cold seep systems are concerned. The basin is considered to be an "ecological desert" with respect to available nutrients and biological diversity. Here we present new results from a high-resolution Sparker seismic survey carried out offshore northern Israel to map the location of gas seepages on the seafloor. A number of shallow cores were extracted from the target areas and water was sampled for chemical analysis. These data will be integrated as a pilot for a larger, interdisciplinary study to identify, map and characterize the geology, biology and chemistry of gas seepages in the eastern Mediterranean.

Lazar, M.; Schattner, U.

2009-04-01

253

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.

Ford, Brent A.

2001-01-01

254

Enhanced oil recovery: Definitions, fundamentals, applications, and research frontiers  

NASA Astrophysics Data System (ADS)

This paper describes the highlights of current oil-recovery technology, including primary, secondary, tertiary, and enhanced recovery processes. Fundamental displacement phenomena are discussed: (1) from a macro-view, such as injection- and production-well patterns, impermeable barriers, and geologic faults; and (2) from a micro-view, which considers oil displacement on a pore-by-pore basis in a three-dimensional interconnected network of flow channels. Applications used to illustrate displacement fundamentals included the major features of water, polymer, and micellar flooding; and steam and CO 2 injection. Also discussed are two principal frontiers of enhanced oil recovery research: definition of the reservoir, and independent measurement of the amount of oil in place.

Simon, Ralph

255

Physical Geology  

NSDL National Science Digital Library

This Tulane University course covers the nature of the Earth, the development of its surficial features, and the results of the interaction of chemical, physical, and biological factors on the planet. Lecture notes are about energy and minerals; igneous, metamorphic and sedimentary rocks; weathering and soils; geologic time; mass wasting; streams; groundwater; wind action and deserts; oceans; deformation of rock; earthquakes and the interior of the Earth; global tectonics; planetary changes; and glaciers.

Nelson, Stephen

256

Helium studies in geology  

NASA Astrophysics Data System (ADS)

A special issue of the Journal of Geophysical Research—Solid Earth and Planets will be devoted to the topic "Helium Studies in Geology." Both helium isotopic research and helium 4 investigations on any phase of geologic application will be included. Individuals are welcome to submit manuscripts for this special issue. The deadline for receipt of papers through the normal JGR submission process is May 30, 1986. Please indicate that the manuscript is for the special issue. For additional information, contact G. M. Reimer, U.S. Geological Survey, MS 963, Denver Federal Center, Denver, CO 80225; telephone: 303236-7886 or JGR editor Gerald Schubert, Department of Earth and Space Sciences, University of California, Los Angeles, CA 90024; telephone: 213-82 5-4577.

257

Characterizing Lunar Crustal Geology  

NASA Astrophysics Data System (ADS)

In our initiative to return to the Moon, knowledge of regional crustal geology is necessary both for locating resources of scientific interest and for establishing a sustained human presence. Characterizing crustal geology with global remote sensing data is difficult due to the types of weathering processes experienced by an airless, geologically torpid planetary body, which tend to reduce lithologic contrast and obscure the lithology of true bedrock. Fortunately, these processes are relatively straightforward, involving parameters with largely understood, fixed rates of flux. We describe a methodology for characterizing the chemical and mineralogical compositions of discrete geologic units, interpreted from remotely sensed surface spectra. The method utilizes two established techniques: small impact ejecta viewing and extrapolation (SIEVE) (McCord et al., JGR 1981; Staid & Pieters, LPSC 29; Kramer et al., LPSC 36; Kramer et al., JGR (in review)) and spectral mixing analysis (SMA) (Adams & Gillespie, Cambridge Univ. Press 2006, and references therein). The results of this work will be invaluable for identifying regions of interest for current and future lunar missions, such as Chandrayaan-1, carrying NASA's Moon Mineralogy Mapper, and Lunar Reconnaissance Orbiter. Furthermore, the methodology can be used to explore other planetary bodies that experience similar weathering processes (e.g., Mercury, Ceres, Vesta, and Mars).

Kramer, G.; Combe, J.; McCord, T.

2007-12-01

258

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

259

Geologic Time  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses the characteristics of geologic time, including the law of superposition, fossil preservation, casts and molds, and various events through the history of the Earth. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

260

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

261

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

262

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.

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

2014-01-01

263

Chapter 4: Geological Carbon Sequestration.  

National Technical Information Service (NTIS)

Carbon sequestration is the long term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. The largest potential reservoirs for storing carbon are the deep oceans and geological reservoirs in the...

J. Friedmann H. Herzog

2006-01-01

264

Geological and inorganic materials. [Review  

SciTech Connect

This review discusses publications describing methods for analysis of geological and inorganic materials during the period November 1982 through November 1984. The topical boundaries of the inorganic and geological materials are somewhat diffuse since closely related topics are reviewed in both the fundamental and application reviews. Articles of particular interest may be found in the reviews of air pollution, ferrous analysis, fuels, surface characterization, and water analysis in the application reviews and many of the fundamental reviews especially sampling, emission spectrometry, atomic adsorption and flame emission spectrophotometry, mass spectrometry, x-ray spectrometry, and surface analysis. The citations of this review may well, by necessity, include some of those listed in other reviews, but for the most part they have been selected from the many thousands available to give the reader an overview of recent advances in each specialty reviewed together with mentions of particularly interesting specific or specialized contributions. 212 references.

Moore, C.B.; Canepa, J.A.

1985-04-01

265

Medical geology: a globally emerging discipline  

Microsoft Academic Search

Medical Geology, the study of the impacts of geologic materials and processes on animal and human health, is a dynamic emerging discipline bringing together the geoscience, biomedical, and public health communities to solve a wide range of environmental health problems. Among the Medical Geology described in this review are examples of both deficiency and toxicity of trace element exposure. Goiter

Joseph E. Bunnell; Robert B. Finkelman; Jose A. Centeno; O. Selinus

2007-01-01

266

Development of a Two-Phase Structural and Optical Model for Understanding the Fundamental Electrochromic Processes in Amorphous Tungsten Oxide Thin Films.  

NASA Astrophysics Data System (ADS)

The evolution of a dense columnar morphology with a related void network structure is a natural result of random ballistic aggregation of atoms during the thin film growth process under low adatom mobility conditions. Thin film properties and applications (e.g. magneto-optic materials and a-Si:H solar cells) are often dominated by this anisotropic morphology. Electrochromism is a phenomenon in which the optical properties of a material change due to the stimulus of an applied electric field. Tungsten oxide (WO _3) is probably the most widely studied electrochromic (EC) material, and is the primary material used as the active layer in EC applications. Although it has been shown that the structure of a-WO_3 thin films is dominated by dense columnar regions and an anisotropic void network, little work has been done on the structure of a-WO_3 as it relates to the EC properties. Amorphous WO_3 thin films have been prepared by reactive dc-magnetron sputtering under different deposition conditions. Through the use of plasma diagnostics, scanning electron microscopy, EC coloration experiments, and spectroscopic ellipsometry, the effect of preparation conditions on film morphology and EC properties have been studied. The results of this study show that a-WO_3 thin films are dominated by a columnar morphology and an intercolumnar void network that strongly influence the EC properties. In addition, real-time spectroscopic ellipsometry (RTSE) experiments on the WO_3 EC coloration process have been performed for the first time. In studies of very thin (~150 A) films by RTSE, the formation of hydrogen tungsten bronze rm(H _{x}WO_3) is controlled by reaction-limited kinetics, and thus it was possible to extract optical dielectric function spectra at different stages of the coloration process. These spectra can be understood in terms of a two-phase physical mixture of WO_3 and rm H_ {x}WO_3 components with relative volume fractions determined in a regression analysis of the spectra. Based on these results, a two-phase model is presented to describe EC processes in a-WO_3. This model sheds light on the fundamental optical and kinetic mechanisms while consistently explaining the morphological dependence of the EC properties.

Witham, Howard Stanley

267

Ontology for Structural Geology  

NASA Astrophysics Data System (ADS)

We present our comprehensive process-based ontology for Structural Geology. This ontology covers major domain concepts, especially those related to geological structure type, properties of these structures, their deformation mechanisms, and the factors that control which deformation mechanisms may operate under certain conditions. The structure class in our ontology extends the planetary structure class of the SWEET ontology by providing additional information required for use in the structural geology domain. The classification followed the architectures of structures, such as structure element, set, zone, and pattern. Our deformation mechanism class does not have a corresponding class in SWEET. In our ontology, it has two subclasses, Macro- and Micro- mechanisms. The property class and the factor class are both subclasses of the physical property class of SWEET. Relationships among those concepts are also included in our ontology. For example, the class structure element has properties associated with the deformation mechanisms, descriptive properties such as geometry and morphology, and physical properties of rocks such as strength, compressibility, seismic velocity, porosity, and permeability. The subject matter expertise was provided by domain experts. Additionally, we surveyed text books and journal articles with the goal of evaluating the completeness and correctness of the domain terms and we used logical reasoners and validators to eliminate logical problems. We propose that our ontology provides a reusable extension to the SWEET ontology that may be of value to scientists and lay people interested in structural geology issues. We have also implemented prototype services that utilize this ontology for search.

Zhong, J.; McGuinness, D. L.; Antonellini, M.; Aydin, A.

2005-12-01

268

Mapping the Seafloor Geology Offshore of Massachusetts  

USGS Publications Warehouse

Introduction 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

2006-01-01

269

Personal Computer (PC) - Based Methods for Integrating, Processing and Visualizing Multivariate Data: Review of Geology, Till Geochemistry, Lake Sediment Geochemistry, and Airborne Geophysical Data from the Beardmore- Geraldton District, Ontario, Canada  

Microsoft Academic Search

2 Multivariate data collected from geological, geochemical and geophysical sources historically have not been managed and evaluated in a single PC-based environment. This tendency is, in part, due to the lack of techniques for integrating, processing and visualizing high-volume datasets from different sources. In this short discussion, the objective is to review the methodologies used to integrate, process and visualize

Greg Hollyer; L. Harvey Thorleifson

270

Principles of nuclear geology  

SciTech Connect

This book treats the basic principles of nuclear physics and the mineralogy, geochemistry, distribution and ore deposits of uranium and thorium. The application of nuclear methodology in radiogenic heat and thermal regime of the earth, radiometric prospecting, isotopic age dating, stable isotopes and cosmic-ray produced isotopes is covered. Geological processes, such as metamorphic chronology, petrogenesis, groundwater movement, and sedimentation rate are focussed on.

Aswathanarayana, U.

1985-01-01

271

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

272

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.

273

Geology of California  

SciTech Connect

This book reviews some of the basic principles of geology and includes a chapter on the Klamath Mountains. Chapters cover the geologic history of California and the geologic features of the various deserts, mountain ranges, plateaus, basins, and valleys of the state, including offshore geology and the San Andreas fault. The authors discuss exotic and suspect terranes, and current theories concerning California geology.

Norris, R.M.; Webb, R.W.

1990-01-01

274

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

275

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

276

Radiometric dating in geology  

NASA Astrophysics Data System (ADS)

The method of dating rocks and minerals is known as geochronology. Although in principle this term could be applied to estimation of relative ages according to traditional geological observation, it is nowadays usually restricted to the quantitative measurement of geological time using the constant-rate natural process of radioactive decay. 14C dating is a technique based on measuring the residual radioactivity of this isotope which decays exponentially from the time of death of organisms which extract it from the atmosphere (e.g. when a living tree becomes simply 'wood'). The halflife of this decay is only 5600 years. Even using pre-concentration techniques and highly sensitive detectors, the practical range of the dating method does not extend back beyond about 100000 years-a period utterly insignificant in terms of the geological evolution of the Earth, which extends over the past 4500 million years. For geological dating one requires naturally occurring elements with much longer halflives. Most of the handful of appropriate decay schemes are listed. Most of the parent elements are rare metal constituents in the bulk chemical composition of the Earth. For such 'trace' elements it is generally convenient to express their concentration in natural materials in parts per million by weight (ppm) and even in the one case of a fairly common element (potassium) only a very small proportion occurs as the radioactive 40K. Also, some of the halflives are very long, even by geological reckoning, so that the actual level of natural radioactivity is rarely more than a few disintegrations per minute per gram.

Pankhurst, R. J.

1980-11-01

277

Natural gas composition in a geological environment and the implications for the processes of generation and preservation  

Microsoft Academic Search

Gases recovered from their location of formation (for example, gas recovered from drill cuttings) are enriched in C2+ components relative to gases recovered from reservoir production or testing streams. Because reservoir gases have been derived through a series of processes including generation from a source with a specific chemical character, primary and secondary migration, accumulation and (selective) preservation, the compound

Lloyd R. Snowdon

2001-01-01

278

Physical Characteristics, Geologic Setting, and Possible Formation Processes of Spring Deposits on Mars Based on Terrestrial Analogs  

Microsoft Academic Search

Spring deposits are predicted as a result of former aquifers on Mars. This study examines the large-scale morphology and their physical processes of formation, growth, and evolution in terms that relate to the search for former aqueous environments on Mars.

L. S. Crumpler

2003-01-01

279

The Serra Pelada Au-PGE deposit, Serra dos Carajás (Pará State, Brazil): geological and geochemical indications for a composite mineralising process  

NASA Astrophysics Data System (ADS)

The Serra Pelada Au-PGE-rich deposit is located in the Serra dos Carajás, a leading mining area in Brazil. This region is characterised by a complex geological and structural framework and is affected by deep lateritisation which has lasted for more than 70 Ma. The Serra Pelada deposit is emplaced in a late-Archean low-grade metasedimentary sequence (Rio Fresco/Águas Claras Formation) which is host to other gold deposits in the region (Igarapé Bahia, Águas Claras). The Rio Fresco/Águas Claras sequence was deposited in tectonic basins developed on Archean basement and Au-bearing greenstone terranes which were intruded by PGE-rich layered mafic complexes (e.g. Luanga). The Serra Pelada mineralisation is located along a regional, complex system of strike-slip faults (Cinzento-Carajás systems) which were active during the late Archean to early Proterozoic. The mineralisation appears to be concentrated along a faulted hinge zone of a fold. Ore zone rock facies are dominated by low-grade ferruginous to carbonaceous metasiltstones and minor sandstones, locally brecciated and cemented by quartz (±sulphide) stockwork. Supergene alteration led to partial to total transformation into friable aggregates of kaolinite, Fe oxide-hydroxides, silica and secondary phosphate-sulphates even at depths exceeding 200 m. Precious metals are exceptionally enriched, with up to more than 1,000 ppm Au+PGE in some peculiar ferruginous-graphitic zones locally called "hidrotermalito". Geochemistry shows complex patterns of major and trace elements, particularly rare-earth elements (REE), in mineralised vs. nonmineralised samples. These patterns are interpreted in terms of variable degree of superposition of hydrothermal and supergene alteration. Precious metals show progressive increase from samples with hydrothermal imprint to samples with supergene imprint. The geological evolution of the Carajás region and the characteristics of mineralisation at Serra Pelada may suggest a composite mineralising process: hydrothermal activity (by fluids likely originated from granitoids) was followed by supergene alteration during long-lasting lateritisation to develop extreme precious metal enrichments in a geological context probably already anomalous for Au and PGE.

Moroni, Marilena; Girardi, Vicente A.; Ferrario, Alfredo

2001-12-01

280

Geology of a complex kimberlite pipe (K2 pipe, Venetia Mine, South Africa): insights into conduit processes during explosive ultrabasic eruptions  

Microsoft Academic Search

K2 is a steep-sided kimberlite pipe with a complex internal geology. Geological mapping, logging of drillcore and petrographic\\u000a studies indicate that it comprises layered breccias and pyroclastic rocks of various grain sizes, lithic contents and internal\\u000a structures. The pipe comprises two geologically distinct parts: K2 West is a layered sequence of juvenile- and lithic-rich\\u000a breccias, which dip 20–45° inwards, and

R. J. Brown; M. Tait; M. Field; R. S. J. Sparks

2009-01-01

281

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

282

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

283

An evaluation of the ERTS data collection system as a potential operational tool. [automatic hydrologic data collection and processing system for geological surveys  

NASA Technical Reports Server (NTRS)

The Earth Resources Technology Satellite Data Collection System has been shown to be, from the users vantage point, a reliable and simple system for collecting data from U.S. Geological Survey operational field instrumentation. It is technically feasible to expand the ERTS system into an operational polar-orbiting data collection system to gather data from the Geological Survey's Hydrologic Data Network. This could permit more efficient internal management of the Network, and could enable the Geological Survey to make data available to cooperating agencies in near-real time. The Geological Survey is conducting an analysis of the costs and benefits of satellite data-relay systems.

Paulson, R. W.

1974-01-01

284

Hydraulic-gas transient processes within the overall phenomenological evolution of the French HLW deep geological disposal: current knowledge in PA perspective  

NASA Astrophysics Data System (ADS)

Because of the creation of the disposal underground facilities, then of the ventilation of whole or part of these facilities during operating period, and finally of hydrogen production, mainly by anoxic corrosion of metallic components, in post-closure period, the phenomenological evolution of a radwaste deep geological repository and its surrounding host rock will be characterized by an hydraulic and gas transient phase until the overall system reach an equilibrium state. This paper presents the analysis of this transient phase carried out in France within the framework of the feasibility study of a HLW and ILLW deep geological disposal in the Callovo-Oxfordian clay layer (Meuse/Haute Marne site) (Dossier 2005 Argile) according to the current state of knowledge: the broad outlines of the expected evolution are described in time and space from operating period to post closure period, taking into consideration the studied design concept (overall architecture, disposal zones, disposal modules, disposal cells, various types of waste, operating conditions…). More particularly for hydrogen, emphasis is focused on space and time organization of production and migration, in particular the various sources of production, the various pathways of migrations and interactions with hydraulics. Although the description is supported by a sound data base on hydraulic and gas production and migration (clay media, engineered materials, corrosion, radiolysis…) and numerical calculations at different scales of time and space, uncertainties exist both in phenomenology (Hydrogen production mechanisms, Hydrogen migration mechanisms in clay media, modeling of mechanisms, values of parameters…) and in simulation (in particular limitations to achieve the various time and space scales and some couplings). So deviations of the expected evolution are discussed. Results of this analysis show that the hydraulic and gas transient phase may present a complex organization in time and space, and may relate to significant scales of time, several tens of thousands to one hundred of thousands years. So the hydraulic - gas transient has to be put in prospective for other processes involved in the phenomenological evolution (thermal, mechanics and chemical processes), so to evaluate if there are the interactions/couplings or not between all these processes in time and space. In particular effect of hydraulic - gas processes on degradation of waste, release and then migration of radionuclide are discussed in PA perspective. In conclusion, ways of progress to describe the hydraulic and gas transient phase are indicated, in view of the demand of a licensing authorization of a repository in 2014.

Wendling, J.; Plas, F.

2009-04-01

285

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

286

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

Microsoft Academic Search

The relationships between stratigraphic and tectonic setting, recharge processes and underground drainage of the glacierised\\u000a karst aquifer system ‘Tsanfleuron-Sanetsch’ in the Swiss Alps have been studied by means of various methods, particularly\\u000a tracer tests (19 injections). The area belongs to the Helvetic nappes and consists of Jurassic to Palaeogene sedimentary rocks.\\u000a Strata are folded and form a regional anticlinorium. Cretaceous

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

2009-01-01

287

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

288

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.

289

The GPlates Geological Information Model and Markup Language  

NASA Astrophysics Data System (ADS)

Understanding tectonic and geodynamic processes leading to the present-day configuration of the Earth involves studying data and models across a variety of disciplines, from geochemistry, geochronology and geophysics, to plate kinematics and mantle dynamics. All these data represent a 3-dimensional spatial and 1-dimensional temporal framework, a formalism which is not exploited by traditional spatial analysis tools. This is arguably a fundamental limit in both the rigour and sophistication in which datasets can be combined for geological "deep time" analysis, and often confines the extent of data analyses to the present-day configurations of geological objects. The GPlates Geological Information Model (GPGIM) represents a formal specification of geological and geophysical data in a time-varying plate tectonics context, used by the GPlates virtual-globe software. It provides a framework in which relevant types of geological data are attached to a common plate tectonic reference frame, allowing the data to be reconstructed in a time-dependent spatio-temporal plate reference frame. The GPlates Markup Language (GPML), being an extension of the open standard Geography Markup Language (GML), is both the modelling language for the GPGIM and an XML-based data format for the interoperable storage and exchange of data modelled by it. The GPlates software implements the GPGIM allowing researchers to query, visualise, reconstruct and analyse a rich set of geological data including numerical raster data. The GPGIM has recently been extended to support time-dependent geo-referenced numerical raster data by wrapping GML primitives into the time-dependent framework of the GPGIM. Coupled with GPlates' ability to reconstruct numerical raster data and import/export from/to a variety of raster file formats, as well as its handling of time-dependent plate boundary topologies, interoperability with geodynamic softwares is established, leading to a new generation of deep-time spatio-temporal data analysis and modelling, including a variety of new functionalities such as 4-D data-mining.

Qin, X.; Müller, R. D.; Cannon, J.; Landgrebe, T. C. W.; Heine, C.; Watson, R. J.; Turner, M.

2012-07-01

290

The GPlates Geological Information Model and Markup Language  

NASA Astrophysics Data System (ADS)

Understanding tectonic and geodynamic processes leading to the present-day configuration of the Earth involves studying data and models across a variety of disciplines, from geochemistry, geochronology and geophysics, to plate kinematics and mantle dynamics. All these data represent a 3-D spatial and 1-D temporal framework, a formalism which is not exploited by traditional spatial analysis tools. This is arguably a fundamental limit in both the rigour and sophistication in which datasets can be combined for geological deep time analysis, and often confines the extent of data analyses to the present-day configurations of geological objects. The GPlates Geological Information Model (GPGIM) represents a formal specification of geological and geophysical data in a time-varying plate tectonics context, used by the GPlates virtual-globe software. It provides a framework in which relevant types of geological data are attached to a common plate tectonic reference frame, allowing the data to be reconstructed in a time-dependent spatio-temporal plate reference frame. The GPlates Markup Language (GPML), being an extension of the open standard Geography Markup Language (GML), is both the modelling language for the GPGIM and an XML-based data format for the interoperable storage and exchange of data modelled by it. The GPlates software implements the GPGIM allowing researchers to query, visualise, reconstruct and analyse a rich set of geological data including numerical raster data. The GPGIM has recently been extended to support time-dependent geo-referenced numerical raster data by wrapping GML primitives into the time-dependent framework of the GPGIM. Coupled with GPlates' ability to reconstruct numerical raster data and import/export from/to a variety of raster file formats, as well as its handling of time-dependent plate boundary topologies, interoperability with geodynamic softwares is established, leading to a new generation of deep-time spatio-temporal data analysis and modelling, including a variety of new functionalities, such as 4-D data-mining.

Qin, X.; Müller, R. D.; Cannon, J.; Landgrebe, T. C. W.; Heine, C.; Watson, R. J.; Turner, M.

2012-10-01

291

Geology of the Caribbean  

USGS Publications Warehouse

The Venezuelan and Colombian basins are located on the Caribbean Plate whilst the Yucatan basin is on the North American Plate. The processes occurring at the boundaries between the Caribbean Plate and the adjacent North American, South American and Cocos Plates, and the resulting surface features and patterns of volcanic and earthquake activity are described. Most of the Caribbean area is floored by atypical oceanic crust and its most valuable main geologic resources identified so far are petroleum, together with sand and gravel. Geological research is being carried out with techniques for broad-range swath imaging of the seafloor, such as GLORIA, and for directly measuring the movement between plates. -J.G.Harvey

Dillon, W. P.; Edgar, N. T.; Scanlon, K. M.; Klitgord, K. D.

1987-01-01

292

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

293

Geologic Mapping on Mars  

NSDL National Science Digital Library

This lab is part of a Lunar and Planetary Geology course offered to both geology and non-geology majors, and it involves basic geological mapping of an area within the Tyrrhena Patera region on Mars. Students are encouraged to work in groups to prepare a geological map from a photomosaic map and to interpret the geologic stratigraphy from a geological map of the greater area. This activity reinforces mapping skills as well as group work skills, and aims to teach students more about Martian stratigraphy and geology through a hands-on activity.

De Villiers, Germari

294

Biologic and geologic responses to physical processes: examples from modern reef systems of the Caribbean-Atlantic region  

NASA Astrophysics Data System (ADS)

Coral reefs and associated depositional environments of the Caribbean-Atlantic region have characteristics that reflect control by physical processes, both oceanic and atmospheric. Wave direction and wave power help determine sites for productive reef development and shape reef morphology as well as community structure. Spur and groove orientations reflect changes in direction of waves as they refract across a reef-dominated shelf. Abrupt topography of reef-dominated shelf margins interacts with tidally modulated flows to create an energetic and productive deep reef environment which is buffered from the modifying effects of forceful wave action. Shallow wave-reef interactions involve dissipative effects of wave breaking, turbulence, and friction, resulting in measured wave energy transformations ranging from 72 to 97% depending on reef configuration and water depth. Dissipative processes produce strong reef-normal surge currents that transport sediment lagoonward, drive backreef lagoon circulation, and influence fluid flow and diagenesis within the reef. The intensity of these processes is modulated at the tidal frequency. Other long period waves (infragravity) are important agents of mass transport of water and fine sediment. Low speed, long duration currents forced by long waves are potentially important for transporting larvae as well as fine sediment out of a given reef-lagoon system. Ocean-scale currents impinging on steep island and continental margin topography may cause reef-limiting upwelling and nutrient loading. The Caribbean Current upwells on the Nicaragua shelf and carbonate platforms of the Nicaraguan Rise. High trophic resources favor algal rather than coral communities and large (20-30 m relief) Halimeda biotherms occupy niches normally reserved for coral reefs. Thermodynamic air-sea interactions (heat, moisture and momentum flux) regulate the physical properties of reef lagoon and bank top waters. In extra-tropical reef settings (e.g. Bermuda, Florida, Bahamas and Arabian Gulf) cold air outbreaks cause precipitous drops in bank water temperatures and significant increases in bank water salinity and suspended sediment load. Water temperatures are routinely forced below the limit for survival of reef corals and many species of calcareous green algae. Associated increases in the density of shallow waters produce a disequilibrium with surface waters of the adjacent ocean favoring shelf transport to deep water sites of reef development and beyond.

Roberts, Harry H.; Wilson, Paul A.; Lugo-Fernández, Alexis

1992-07-01

295

MER Field Geologic Traverse in Gusev Crater, Mars: Initial Results From the Perspective of Spirit  

NASA Technical Reports Server (NTRS)

This report casts the initial results of the traverse and science investigations by the Mars Exploration Rover (MER) Spirit at Gusev crater [1] in terms of data sets commonly used in field geologic investigations: Local mapping of geologic features, analyses of selected samples, and their location within the local map, and the regional context of the field traverse in terms of the larger geologic and physiographic region. These elements of the field method are represented in the MER characterization of the Gusev traverse by perspective-based geologic/morphologic maps, the placement of the results from Mossbauer, APXS, Microscopic Imager, Mini-TES and Pancam multispectral studies in context within this geologic/ morphologic map, and the placement of the overall traverse in the context of narrow-angle MOC (Mars Orbiter Camera) and descent images. A major campaign over a significance fraction of the mission will be the first robotic traverse of the ejecta from a Martian impact crater along an approximate radial from the crater center. The Mars Exploration Rovers have been conceptually described as 'robotic field geologists', that is, a suite of instruments with mobility that enables far-field traverses to multiple sites located within a regional map/image base at which in situ analyses may be done. Initial results from MER, where the field geologic method has been used throughout the initial course of the investigation, confirm that this field geologic model is applicable for remote planetary surface exploration. The field geologic method makes use of near-field geologic characteristics ('outcrops') to develop an understanding of the larger geologic context through continuous loop of rational steps focused on real-time hypothesis identification and testing. This poster equates 'outcrops' with the locations of in situ investigations and 'regional context' with the geology over distance of several kilometers. Using this fundamental field geologic method, we have identified the basic local geologic materials on the floor of Gusev at this site, their compositions and likely lithologies, origins, processes that have modified these materials, and their potential significance in the interpretation of the regional geology both spatially and temporally.

Crumpler, L.; Cabrol, N.; desMarais, D.; Farmer, J.; Golmbek, M.; Grant, J.; Greely, R.; Grotzinger, J.; Haskin, L.; Arvidson, R.

2004-01-01

296

Controlling fundamentals in high-energy high-rate pulsed power materials processing of powdered tungsten, titanium aluminides, and copper-graphite composites. Final technical report, 1 Jun 87-31 Aug 90  

Microsoft Academic Search

This study was conducted to determine the controlling fundamentals in the high-energy high-rate (1 MJ in 1s) processing of metal powders. This processing utilizes a large electrical current pulse to heat a pressurized powder mass. The current pulse was provided by a homopolar generator. Simple short cylindrical shapes were consolidated so as to minimize tooling costs. Powders were subjected to

C. Persad; H. L. Marcus; D. L. Bourell; Z. Eliezer; W. F. Weldon

1990-01-01

297

Proceedings: Joint Symposium on Dry SO2 and Simultaneous SO2/NOx Control Technologies (1st). Volume 1. Fundamental Research and Process Development.  

National Technical Information Service (NTIS)

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 re...

P. J. Chappell

1985-01-01

298

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...

299

Digital Geology of Idaho  

NSDL National Science Digital Library

This online course systematically divides Idaho geology into 15 individual teaching modules which correspond with a two-credit, 15-week classroom course. Each module covers a specific area or type of geology in the state of Idaho. Topics include geology of basement rocks, rocks and geology of the Belt Supergroup, tectonic regimes, and geologic history. There are also modules on rocks and geology of the Idaho Batholith, volcanic history and deposits of the Snake River Plain and Columbia Plateau, and Pleistocene glaciation and floods from Lakes Missoula and Bonneville. Each of the modules provides geologic maps from a recently developed Geologic Map of Idaho, produced by the Idaho Geological Survey, and most also feature fly-throughs in which geologic information is draped over topography to provide visualizations of the geology along Idaho rivers.

300

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.

301

The NASA\\/USGS Planetary Geologic Mapping Program  

Microsoft Academic Search

NASA's Planetary Geologic Mapping Program (PGM) publishes geologic maps of the planets based on released, geodetically controlled spacecraft data. The general objectives of PGM include (1) production of geologic maps that will greatly increase our knowledge of the materials and processes that have contributed to the evolution of Solar System bodies, and (2) geologic surveys of areas of special interest

K. Tanaka

2006-01-01

302

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

303

Geological hazards risk regionalization based on GIS in Chongzhou city  

Microsoft Academic Search

After Wenchuan Earthquake on May 12, 2008, various geological hazards happened frequently in Chongzhou city, Sichuan.This paper analyzes factors inducing hazards by weighted comprehensive evaluation (WCE) and analytic hierarchy process (AHP), and builds the geological hazards assessment model.On the basis, the map of geological hazards lability zoning is drew. The study shows that geological hazards in Chongzhou city are mainly

Chengqiang Shu; Liangqun Jiang

2011-01-01

304

Spatial and statistical GIS Applications for geological and environmental courses  

NASA Astrophysics Data System (ADS)

Building student's career through undergraduate and graduate courses integrated with modern statistical and GIS software foster a competitive curriculum for their future employment. We present examples that may be introduced in geological courses (e.g. mineralogy, geomorphology, geochronology, structural geology, tectonics, stratigraphy) and environmental courses (natural hazards, hydrology, atmospheric science). Univariate and multivariate statistical models can be used for the interpretation and mapping of the geological and environmental problems. Some of the main statistical univariate models such as the normal distribution as well as the multivariate methods such as the principal component analysis, cluster analysis and factor analysis are the basic methods for understanding the variables of the environmental and geological problems. Examples are presented describing the basic steps for the solution of the problems. Some of the geological problems in different scales are the interpretation of 3D structural data, identification of suitable outcrops for mapping shear sense kinematic indicators. categorical or cluster analysis on lineations depending on their origin, topology of mineral assemblages and spatial distribution of their c-axis, distinguishing paleo-elevations using cluster analysis in geomorphological structures using LiDAR intensity and elevation data for determination of meander evolution patterns and prediction of vulnerable sites for flooding or landsliding. Other applications in atmospheric and hydrology science are the prediction of ground level ozone and the decomposition of water use time series. Those fundamental statistical and spatial concepts may be used in the field or in the lab. In the lab, modern computers and friendly interface user software allow students to process data using advanced statistical methods and GIS techniques. Modern applications in tablets or smart phones may complement field work. Teaching those methods can facilitate advanced mapping, optimize sample collection distribution, field decisions, and later lab data processing.

Marsellos, A.; Tsakiri, K.

2012-12-01

305

Evaluation of three electronic report processing systems for preparing hydrologic reports of the U.S Geological Survey, Water Resources Division  

USGS Publications Warehouse

In 1987, the Water Resources Division of the U.S. Geological Survey undertook three pilot projects to evaluate electronic report processing systems as a means to improve the quality and timeliness of reports pertaining to water resources investigations. The three projects selected for study included the use of the following configuration of software and hardware: Ventura Publisher software on an IBM model AT personal computer, PageMaker software on a Macintosh computer, and FrameMaker software on a Sun Microsystems workstation. The following assessment criteria were to be addressed in the pilot studies: The combined use of text, tables, and graphics; analysis of time; ease of learning; compatibility with the existing minicomputer system; and technical limitations. It was considered essential that the camera-ready copy produced be in a format suitable for publication. Visual improvement alone was not a consideration. This report consolidates and summarizes the findings of the electronic report processing pilot projects. Text and table files originating on the existing minicomputer system were successfully transformed to the electronic report processing systems in American Standard Code for Information Interchange (ASCII) format. Graphics prepared using a proprietary graphics software package were transferred to all the electronic report processing software through the use of Computer Graphic Metafiles. Graphics from other sources were entered into the systems by scanning paper images. Comparative analysis of time needed to process text and tables by the electronic report processing systems and by conventional methods indicated that, although more time is invested in creating the original page composition for an electronically processed report , substantial time is saved in producing subsequent reports because the format can be stored and re-used by electronic means as a template. Because of the more compact page layouts, costs of printing the reports were 15% to 25% less than costs of printing the reports prepared by conventional methods. Because the largest report workload in the offices conducting water resources investigations is preparation of Water-Resources Investigations Reports, Open-File Reports, and annual State Data Reports, the pilot studies only involved these projects. (USGS)

Stiltner, G. J.

1990-01-01

306

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.

307

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

308

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

309

Assessing Fundamental Science  

NSF Publications Database

Assessing ASSESSING FUNDAMENTAL SCIENCE A Report from the Subcommittee on Research Committee on ... in the Context of GPRA Section III: Performance Measures Section IV: Concluding Points References ...

310

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

311

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).

312

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

313

Quality assurance plan for the collection and processing of sediment data by the U.S. Geological Survey, Water Resources Division  

USGS Publications Warehouse

The U.S. Geological Survey sediment data quality assurance plan identifies and explains required quality assurance and suggested quality control practices. The approach is to subdivide the process for obtaining sediment data into 3 parts: (1) field, (2) office, and (3) laboratory operations. The report also summarizes recommended goals for each subcategory. The quality assurance and quality control practices are described by stating the minimum acceptable activities that a district should conduct. For example, the plan describes field calibration of thermometers and standards used to calibrate a thermometer. The plan also proposes corrective actions if the quality control procedures identify a problem. The plan describes the formal reports prepared by a district that describe the completeness of sediment data and presents an evaluation of data obtained by the quality assurance program. Also described in the plan are the external (non-district) reviews that are needed to examine district sediment operations for conformity with district quality assurance plans and national quality assurance programs.

Knott, J. M.; Glysson, G. D.; Malo, B. A.; Schroeder, L. J.

1993-01-01

314

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

315

Constraints from Field Geology for Numerical Modeling of the Crustal Overturn Processes During the Cretaceous High-Magma-Flux Episode in the Central and Southern Sierra Nevada, USA  

NASA Astrophysics Data System (ADS)

Building on prior studies, recent fieldwork combined with geochronology, thermobarometry and geochemistry studies in the Cretaceous Sierra Nevada arc reveal the following arc-scale features: 1) The Middle to Late Cretaceous Sierra Nevada arc has a 30-35 km thick granodioritic to tonalitic upper-middle crust and may have had up to 30-35 km of mafic to ultramafic lower crust, including dehydrated amphibolitic residues. 2) Plutons emplaced during the ~20 myr long High-Magma-Flux Episode (HMFE, 105-85 Ma) include large batholiths (~1000 km2 at exposure level) with growth histories occurring over millions of years (e.g. ~9 myr for Tuolumne Batholith). Magma pulses creating such large intrusions could vary from up to 103 km3 in dimension depending on different growth models. 3) In the central Sierra Nevada, emplacement depths of the granitoid plutons during the HMFE are 7-15 km with shallow emplaced plutons’ solidi at usually ~700 -760 °C. 4) Plutons intruding only slightly older volcanic host rocks in the central and southern Sierra Nevada indicate that host rocks’ downward displacement of ~7-25 km depths occurred within 1-3 myr. This process is accompanied with the long-lived arc exhumation since at least middle Jurassic. 5) Steep syn-emplacement subsolidus lineations, rim monoclines, and plastic shear strain in pluton aureoles suggest ductile deformations of host rock materials. 6) Partial melting occurred along the margins of plutons and in the middle-lower crust, as represented in the more deeply exposed southern Sierra (30-45 km). 7) Magmatic to subsolidus foliations in plutons and ductile shear zones in host rocks indicate NW-trending transpressional tectonics during the HMFE. 8) Isotopic oxygen data and mass balance calculation indicate that crustal components provides more than 50% of the entire arc’s mass. Intra-crustal magma sources of the HMFE are sustained possibly by thickened crust due to contractional tectonics. These observations in the central and southern Sierra Nevada allow us to apply the MILAMIN_VEP, a thermo-mechanical marker-in-cell visco-elasto-plastic finite element code, to simulate more realistic scenarios of arc-scale material exchange processes. The code deals with continuous changes of density, water content, and partial melting conditions of lithosphere rocks based on calculated thermodynamic phase diagrams of differential rock types (using Perple_X). The model also takes the central Andes as a possible modern analogy for the Cretaceous Sierra Nevada. Seismic lithospherical structures, geothermal gradient, and other geological constraints are considered in the model. Aiming to yield geologically and geophysically testable results, the simulations test the hypothesis of host rock downward flow or crustal overturn processes during the HMFE, transpressional tectonics and exhumation, and to shed light on the mechanisms and controlling factors of the downward flow processes.

Cao, W.; Paterson, S. R.; Kaus, B. J.; Anderson, J. L.; Memeti, V.

2010-12-01

316

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

317

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.

318

faults role in geological processes. Repeated changing of activity mode and magnitude from basin formation to mountain belt staking: the case of the Sicilian Chain (Central Mediterranean)  

NASA Astrophysics Data System (ADS)

Faults reactivation (positive, oblique or negative inversions) often drives mountain building processes, from basin formation to accretionary wedge emplacement and its syn- and post-orogenic modifications. Several analytical studies on faults reactivation highlighted the importance of pre-existing fault orientation in the stress field, even though reactivation processes have only recently been considered as an important control in fault propagation. A better understanding of reactivation is essential to establish whether a fault is extinct or not, to better evaluate possible episodic fault activity and to determine the effects of reactivation on fault-growth behaviour and scaling relationships. Inherited normal faults pattern deriving from basin formation (i.e.: passive margin evolution), involved later in orogenic processes, may represents a constraint feature that controls the chain architecture and so the emplacement pattern and kinematic partition. In fact, these faults form zones of mechanical weakness that influence the architecture, kinematic pattern and distribution of crustal-scale deformation in both continental and oceanic regions. As long as a pre-existing fault remains mechanically weaker than its surroundings, strain is preferentially concentrated in the fault zone. This occurs, irrespective of whether the deformation is continuous or interrupted by periods of little activity, because pre-existing faults are surfaces along which the cohesive strength and the friction coefficient are lower than those of unfractured rock volumes. Otherwise, new-timed of thrust geometries firstly activated in convergent settings may act as a preferential strain partitioning zones during intra-collisional kinematic evolution processes driving the chain building, for example related to the mechanical status of the chain-foredeep-foreland system (i.e.: wedge subcritical, critical or supercritical stages). Multistep faults activities may be recognised through mesostructural analysis of master and minor faults populations recorded within the basin successions that experienced afterwards positive inversion to form thrust sheets in collisional-dominated settings. In Sicily (Central Mediterranean) a lot of pre-, syn- and post-orogenic brittle structures have been analysed. These faults have often recorded overprinted kinematic indicators, suggesting repeated interplay between extensional/oblique/compressional stress fields during geologic time. A comparison of structural and syn-deformational stratigraphic features allow us to recognise the palaeotectonic history of the Sicilian Chain and to hypothesise its kinematic evolution, from basin formation to the chain building and -earlier- chain modification of this segment of the Maghrebides African Margin. These faults experienced repeated changing of activity mode (positive and negative reactivations), magnitude and surface geometries, determining obstacles or preferential ways for strain partitioning, with regards to their size and orientation, during the syn- and post-orogenic processes.

Nigro, Fabrizio; Renda, Pietro; Favara, Rocco

2010-05-01

319

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

320

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  

Microsoft Academic Search

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,

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

2000-01-01

321

Venus geology  

NASA Astrophysics Data System (ADS)

The Magellan mission to Venus is reviewed. The scientific investigations conducted by 243-day cycles encompass mapping with a constant incidence angle for the radar, observing surface changes from one cycle to the next, and targeting young-looking volcanos. The topography of Venus is defined by the upper boundary of the crust and upwelling from lower domains. Tectonic features such as rift zones, linear mountain belts, ridge belts, and tesserae are described. The zones of tesserae are unique to the planet. Volcanism accounts for about 80 percent of the observed surface, the remainder being volcanic deposits which have been reworked by tectonism or impacts. Magellan data reveal about 900 impact craters with flow-like ejecta resulting from the fall of meteoroids. It is concluded that the age of the Venusian surface varies between 0 and 800 million years. Tectonic and volcanic activities dominate the formation of the Venus topography; such processes as weathering and erosion are relatively unimportant on Venus.

McLaughlin, W. I.

1991-05-01

322

Kentucky Geological Survey  

NSDL National Science Digital Library

The University of Kentucky maintains the Kentucky Geological Survey Web site. Visitors will find a number of educational general information pages on rocks and minerals, fossils, coal, geologic hazards, industrial minerals, maps and GIS, oil and natural gas, and water, as well as the general geology of Kentucky. Each page contains specific information, data, and research summaries from the university. The geology of Kentucky page, for example, shows a map of geologic periods and gives descriptions of the rock strata in the state, a description of its landforms, and a geological photo album of physiographic regions and points of interest.

1997-01-01

323

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.

2011-07-18

324

Efficient Geological Modelling of Large AEM Surveys  

NASA Astrophysics Data System (ADS)

Combining geological expert knowledge with geophysical observations into a final 3D geological model is, in most cases, not a straight forward process. It typically involves many types of data and requires both an understanding of the data and the geological target. When dealing with very large areas, such as modelling of large AEM surveys, the manual task for the geologist to correctly evaluate and properly utilise all the data available in the survey area, becomes overwhelming. In the ERGO project (Efficient High-Resolution Geological Modelling) we address these issues and propose a new modelling methodology enabling fast and consistent modelling of very large areas. The vision of the project is to build a user friendly expert system that enables the combination of very large amounts of geological and geophysical data with geological expert knowledge. This is done in an "auto-pilot" type functionality, named Smart Interpretation, designed to aid the geologist in the interpretation process. The core of the expert system is a statistical model that describes the relation between data and geological interpretation made by a geological expert. This facilitates fast and consistent modelling of very large areas. It will enable the construction of models with high resolution as the system will "learn" the geology of an area directly from interpretations made by a geological expert, and instantly apply it to all hard data in the survey area, ensuring the utilisation of all the data available in the geological model. Another feature is that the statistical model the system creates for one area can be used in another area with similar data and geology. This feature can be useful as an aid to an untrained geologist to build a geological model, guided by the experienced geologist way of interpretation, as quantified by the expert system in the core statistical model. In this project presentation we provide some examples of the problems we are aiming to address in the project, and show some preliminary results.

Bach, Torben; Martlev Pallesen, Tom; Jørgensen, Flemming; Lundh Gulbrandsen, Mats; Mejer Hansen, Thomas

2014-05-01

325

OneGeology-Europe - The Challenges and progress of implementing a basic geological infrastructure for Europe  

NASA Astrophysics Data System (ADS)

OneGeology-Europe is making geological spatial data held by the geological surveys of Europe more easily discoverable and accessible via the internet. This will provide a fundamental scientific layer to the European Plate Observation System Rich geological data assets exist in the geological survey of each individual EC Member State, but they are difficult to discover and are not interoperable. For those outside the geological surveys they are not easy to obtain, to understand or to use. Geological spatial data is essential to the prediction and mitigation of landslides, subsidence, earthquakes, flooding and pollution. These issues are global in nature and their profile has also been raised by the OneGeology global initiative for the International Year of Planet Earth 2008. Geology is also a key dataset in the EC INSPIRE Directive, where it is also fundamental to the themes of natural risk zones, energy and mineral resources. The OneGeology-Europe project is delivering a web-accessible, interoperable geological spatial dataset for the whole of Europe at the 1:1 million scale based on existing data held by the European geological surveys. Proof of concept will be applied to key areas at a higher resolution and some geological surveys will deliver their data at high resolution. An important role is developing a European specification for basic geological map data and making significant progress towards harmonising the dataset (an essential first step to addressing harmonisation at higher data resolutions). It is accelerating the development and deployment of a nascent international interchange standard for geological data - GeoSciML, which will enable the sharing and exchange of the data within and beyond the geological community within Europe and globally. The geological dataset for the whole of Europe is not a centralized database but a distributed system. Each geological survey implements and hosts an interoperable web service, delivering their national harmonized geological data. These datasets are registered in a multilingual catalogue, who is one the main part of this system. This catalogue and a common metadata profile allows the discovery of national geological and applied geological maps at all scapes, Such an architecture is facilitating re-use and addition of value by a wide spectrum of users in the public and private sector and identifying, documenting and disseminating strategies for the reduction of technical and business barriers to re-use. In identifying and raising awareness in the user and provider communities, it is moving geological knowledge closer to the end-user where it will have greater societal impact and ensure fuller exploitation of a key data resource gathered at huge public expense. The project is providing examples of best practice in the delivery of digital geological spatial data to users, e.g. in the insurance, property, engineering, planning, mineral resource and environmental sectors. The scientifically attributed map data of the project will provide a pan-European base for science research and, importantly, a prime geoscience dataset capable of integration with other data sets within and beyond the geoscience domain. This presentation will demonstrate the first results of this project and will indicate how OneGeology-Europe is ensuring that Europe may play a leading role in the development of a geoscience spatial data infrastructure (SDI) globally.

Asch, Kristine; Tellez-Arenas, Agnes

2010-05-01

326

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

327

Jewish Fundamentalism in Israel.  

National Technical Information Service (NTIS)

History, Development, evolution and current significance to Jewish fundamental Ism in Israel. Study traces origins of this movement to Rabbi Abraham Isaac Kook through the Gush Emunim and includes an indepth analysis of the book The Zionist Revolution by ...

I. S. Lustick

1986-01-01

328

Fundamentals of Physics  

NSDL National Science Digital Library

This website provides information about the textbook "Fundamentals of Physics" by Halliday, Resnick, and Walker. It contains links to both student and teacher resources that are intended to be used along with the book and information about adopting the text.

Halliday, David; Resnick, Robert; Walker, Jearl

2003-12-02

329

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.

2011-03-30

330

Fundamental strings in SFT  

NASA Astrophysics Data System (ADS)

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).

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

2005-07-01

331

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

332

Fundamentals of Electricity  

NSDL National Science Digital Library

This Tutorial Guide is designed to familiarize you with the Fundamentals of Electricity and its elements. As you go through the guide, you will be presented with a series of topics. To help your retention, you will then be given a Quiz on the information. You will NOT be graded. This is designed only to help you retain information on the fundamentals of electricity systems.

2010-06-15

333

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.

334

Geologic spatial analysis  

SciTech Connect

This report describes the development of geologic spatial analysis research which focuses on conducting comprehensive three-dimensional analysis of regions using geologic data sets that can be referenced by latitude, longitude, and elevation/depth. (CBS)

Thiessen, R.L.; Eliason, J.R.

1989-01-01

335

GSA Geologic Time Scale  

NSDL National Science Digital Library

This Geological Society of America (GSA) site contains a detailed geologic time scale as an educational resource. It may be downloaded to a larger size, and includes all Eras, Eons, Periods, Epochs and ages as well as magnetic polarity information.

1999-01-01

336

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

337

What is Geologic Time?  

NSDL National Science Digital Library

This USGS site employs graphics and text to explain geological time. The different geological eons, eras, epochs and periods are defined and put into perspective. The site also provides links to many terms and concepts for further exploration.

Usgs

338

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.

339

Iowa Geological Survey Bureau  

NSDL National Science Digital Library

The Iowa Geological Survey Bureau (GSB) homepage contains: general information about the geology of Iowa; the Natural Resources Geographic Information System, which is a collection of databases on geology and water wells; and information about GSB staff, geologic studies, water monitoring programs, and services. There are maps, photographs, general interest articles, technical abstracts, lists of available publications, and an on-line book about the natural resource history of Iowa.

340

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.

Bennington, Bret

341

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.

Krystek, Lee; Mystery, The M.

342

Geological rhythms and cometary impacts  

NASA Technical Reports Server (NTRS)

Time series analysis reveals two dominant, long-term periodicities approximately equal to 32 and 260 million years in the known series of geological and biological upheavals during the Phanerozoic Eon. The cycles of these episodes agree in period and phase with the cycles of impact cratering on Earth, suggesting that periodic comet impacts strongly influence Earth processes.

Rampino, M. R.; Strothers, R. B.

1984-01-01

343

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.

344

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.

345

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.

Kane, Jacqueline

2004-09-01

346

Geological age of reactors  

NASA Astrophysics Data System (ADS)

Nuclear reactors become obsolete by wearing out or by becoming outclassed or out of date. The lifetime of a conventional power reactor is probably less that 30 years, but the life of its potentially dangerous radioactivity is now known to be of a geological time scale. When a reactor is shutdown permanently, the fuel rods, cooling water, and radioactively ‘hot’ pieces are removed for long-term storage. High-level and low-level radioactive isotopes contained in the liquids and solids removed present a special problem (see Eos, Feb. 9, 1982, p. 147). It is the main frame and construction of worn out reactors that are the major problem, however. Mainly because of neutron activation processes that occur during reactor operation, components have been found to contain nickel-59 and niobium-94, both of which have very long half-lives: 80,000 and 20,300 years, respectively. The two isotopes are only present in trace amounts in metals incorporated in reactor components, but they emit levels of radiation above acceptable levels. The result is that the entire reactors must be dismantled, reduced to shippable size pieces, and the pieces stored for geologic time periods (several half-lives).

Bell, Peter M.

347

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.

348

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.

349

Utah Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Utah Geological Survey. Materials available here include news articles and information on geologic hazards; information on places of geological interest; and popular geology topics such as earthquakes, rocks and minerals, fossils, economic resources, groundwater resources, and others. Educational resources include teaching kits, the 'Teacher's Corner' column in the survey's newsletter, and a series of 'Glad You Asked' articles on state geological topics. There is also an extensive list of free K-12 educational materials, as well as a set of curriculum materials such as activity packets, slide shows, and teachers' handbooks, which are available to order.

350

Strategic Information Resources Management: Fundamental Practices.  

ERIC Educational Resources Information Center

Discusses six fundamental information resources management (IRM) practices in successful organizations that can improve government service delivery performance. Highlights include directing changes, integrating IRM decision making into a strategic management process, performance management, maintaining an investment philosophy, using business…

Caudle, Sharon L.

1996-01-01

351

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

352

Ohio Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Ohio Geological Survey. Materials available through the site include a variety of publications, particularly the Survey's reports, bulletins, information circulars, guidebooks, and many others. There is an extensive selection of maps, including topographic maps in several scales, and downloadable geologic maps of several themes (drift thickness, bedrock geology, karst areas, glacial geology, and many others), as well as digital maps and data. The interactive maps section features online map viewers of abandoned mines, earthquake epicenters, surficial geology, geology of Lake Erie, and others. The educational resources page has links to the 'Hands On Earth' series of activities, GeoFacts (short bulletins on Ohio geological topics), nontechnical educational leaflets, field guides, and links to other publications, rock and mineral clubs, educational associations, and related websites. There is also a link to the Ohio Seismic Network, a network of seismograph stations located at colleges, universities, and other institutions that collects and disseminates information about earthquakes in Ohio.

353

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.

354

Rheology and density of glucose syrup and honey: Determining their suitability for usage in analogue and fluid dynamic models of geological processes  

NASA Astrophysics Data System (ADS)

Analogue models of lithospheric deformation and fluid dynamic models of mantle flow mostly use some kind of syrup such as honey or glucose syrup to simulate the low-viscosity sub-lithospheric mantle. This paper describes detailed rheological tests and density measurements of three brands of glucose syrup and three brands of honey. Additional tests have been done for one brand of glucose syrup that was diluted with water to various degrees (2%, 5% and 10% by weight). The rheological tests have been done to test the effect of shear strain, shear rate and temperature on the dynamic viscosity of the syrup. The results show that the viscosity of all glucose syrups and honeys is independent of shear strain (i.e. no strain hardening or softening). The viscosity of the glucose syrups is independent of shear rate (??), i.e. linear-viscous or Newtonian, in the range ??=10-4-10 s with stress exponents that are almost identical to one ( n = 0.995-1.004). All the honeys show a very weak, but consistent, decrease in viscosity with increasing shear rate of 7-14% from 10 -3 to 10 0 s -1 and have stress exponents more distinct from one ( n = 1.007-1.026). All syrups have a viscosity that is strongly dependent on temperature in the range 0-50 °C, where viscosity decreases with increasing temperature. Such decrease can be fitted with exponential and Arrhenius functions, with the latter giving the best results. Furthermore, the viscosity of glucose syrup decreases approximately exponentially with increasing water content. Oscillation tests indicate that the rheology of all the syrups is entirely dominated by viscous behaviour and not by elastic behaviour at frequencies of 10 -3-10 2 Hz. Finally, the density investigations show that the density of glucose syrup and honey decreases approximately linearly with increasing temperature in the range 10-70 °C, with coefficients of thermal volumetric expansion at 20 °C of 3.89-3.95 × 10 -4 °C -1 and 4.57-4.81 × 10 -4 °C -1 for glucose syrup and honey, respectively. The new results demonstrate that glucose syrups and (to a lesser degree) honeys are well suited for usage in analogue and fluid dynamic experiments to represent linear-viscous strain independent and shear rate independent rheologies to model geological processes. Glucose syrups have the added advantage of being more transparent than honeys, allowing for accurately resolving and quantifying flow patterns in the fluid during a model run.

Schellart, W. P.

2011-06-01

355

Fundamentals of fluid sealing  

NASA Technical Reports Server (NTRS)

The fundamentals of fluid sealing, including seal operating regimes, are discussed and the general fluid-flow equations for fluid sealing are developed. Seal performance parameters such as leakage and power loss are presented. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. The concept of pressure balancing is presented, as are differences between liquid and gas sealing. Mechanisms of seal surface separation, fundamental friction and wear concepts applicable to seals, seal materials, and pressure-velocity (PV) criteria are discussed.

Zuk, J.

1976-01-01

356

Geological consequences of superplumes  

SciTech Connect

Superplumes are suggested to have caused the period of constant normal magnetic polarity in mid-Cretaceous time (124-83 Ma) and, possibly, the period of constant reversed polarity in Pennsylvania-Permian time (323-248 Ma). These times coincide with increases in world temperature, deposition of black shales, oil generation, and eustatic sea level in the mid-Cretaceous, and increased coal generation and gas accumulation in the Pennsylvanian-Permian, accompanied by an intracratonic Pennsylvanian transgression of epicontinental seas. These geologic anomalies are associated with episodes of increased world-wide ocean-crust production and mantle outgassing, especially of carbon and nutrients. These superplumes originated just above the core-mantle boundary, significantly increased convection in the outer core, and stopped the magnetic field reversal process for 41 m.y. in the Cretaceous and 75 m.y. in Pennsylvanian-Permian time.

Larson, R.L. (Univ. of Rhode Island, Narragansett (United States))

1991-10-01

357

Geological consequences of superplumes  

NASA Astrophysics Data System (ADS)

Superplumes are suggested to have caused the period of constant normal magnetic polarity in mid-Cretaceous time (124-83 Ma) and, possibly, the period of constant reversed polarity in Pennsylvanian-Permian time (323-248 Ma). These times coincide with increases in world temperature, deposition of black shales, oil generation, and eustatic sea level in the mid-Cretaceous, and increased coal generation and gas accumulation in the Pennsylvanian-Permian, accompanied by an intracratonic Pennsylvanian transgression of epicontinental seas. These geologic anomalies are associated with episodes of increased world-wide ocean-crust production and mantle outgassing, especially of carbon and nutrients. These superplumes originated just above the core-mantle boundary, significantly increased convection in the outer core, and stopped the magnetic field reversal process for 41 m.y. in the Cretaceous and 75 m.y. in Pennsylvanian-Permian time.

Larson, Roger L.

1991-10-01

358

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

359

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.

360

Exchange rates and fundamentals  

Microsoft Academic Search

Standard economic models hold that exchange rates are influenced by fundamental variables such as relative money supplies, outputs, inflation rates and interest rates. Nonetheless, it has been well documented that such variables little help predict changes in floating exchange rates Š that is, exchange rates follow a random walk. We show that the data do exhibit a related link suggested

Charles Engel; Kenneth D. West

2003-01-01

361

Exchange rates and fundamentals  

Microsoft Academic Search

Standard economic models hold that exchange rates are influenced by fundamental variables such as relative money supplies, outputs, inflation rates and interest rates. Nonetheless, it has been well documented that such variables little help predict changes in floating exchange rates - that is, exchange rates follow a random walk. We show that the data do exhibit a related link suggested

Charles Engel; Kenneth D. West

2003-01-01

362

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

363

Reading Is Fundamental, 1977.  

ERIC Educational Resources Information Center

Reading Is Fundamental (RIF) is a national, nonprofit organization designed to motivate children to read by making a wide variety of inexpensive books available to them and allowing the children to choose and keep books that interest them. This annual report for 1977 contains the following information on the RIF project: an account of the…

Smithsonian Institution, Washington, DC. National Reading is Fun-damental Program.

364

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.

2013-08-12

365

The Fundamental Property Relation.  

ERIC Educational Resources Information Center

Discusses a basic equation in thermodynamics (the fundamental property relation), focusing on a logical approach to the development of the relation where effects other than thermal, compression, and exchange of matter with the surroundings are considered. Also demonstrates erroneous treatments of the relation in three well-known textbooks. (JN)

Martin, Joseph J.

1983-01-01

366

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

367

Rip Currents: Nearshore Fundamentals  

NSDL National Science Digital Library

The Rip Currents: Nearshore Fundamentals module provides insight into how nearshore circulation and wave dynamics are involved in rip current formation. Topics covered in this module include: nearshore terminology, circulation and waves, rip current characteristics, and rip current forcing mechanisms. This module is the second of three modules covering the forecasting of rip currents.

Spangler, Tim

2004-12-13

368

Fundamentals of quantitative research  

Microsoft Academic Search

The main purpose of this article is to introduce some important fundamental concepts of quantitative research to readers especially novice researchers. It comprises types of research, definitions of quantitative research, different types and assumptions of quantitative research, when to use and not to use quantitative methods, advantages, common approaches and samples of quantitative research, and common misconceptions. Besides, a set

Suphat Sukamolson

369

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

370

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

371

Process and device for injecting a liquid agent used for treating a geological formation in the vicinity of a well bore traversing this formation  

SciTech Connect

A technique is disclosed for liquid treating a geological formation. It comprises spraying the liquid with a pressurized carrier gas, using a spraying pipe whose length and diameter are adjusted as a function of the pressure prevailing at the level of the formation and of the characteristics of the injected liquid and the pressurized carrier gas, so that the size of the liquid droplets at the outlet of the spraying pipe has a narrow range of distribution about a single preselected value.

Colonna, J.; Fitremann, Jm.; Genin, R.; Sarda, Jp.

1984-02-14

372

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.

Tucker, Trileigh

373

Geologic Time: Online Edition  

NSDL National Science Digital Library

Offered by the United States Geological Survey (USGS) as a general interest publication, this site is an online edition of a text by the same name, offering a concise overview of the concepts associated with the age of the Earth. The online edition was revised in October of 1997 to reflect current thinking on this topic. Section headers are Geologic Time, Relative Time Scale, Major Divisions of Geologic Time, Index Fossils, Radiometric Time Scale, and Age of the Earth.

1997-10-09

374

Sedimentology and petroleum geology  

SciTech Connect

This book presents an introduction to sedimentology as well as petroleum geology. It integrates both subjects, which are closely related but mostly treated separately. The author covers the basic aspects of sedimentology, sedimentary geochemistry and diagenesis. Principles of stratigraphy, seismic stratigraphy and basin modelling forms the base for the part on petroleum geology. Subjects discussed include the composition of kerogen and hydrocarbons, theories of migration and trapping of hydrocarbons and properties of reservoir rocks. Introductions to well logging and production geology are given.

Bjorlykke, K.O. (Oslo Univ. (Norway))

1989-01-01

375

North Carolina Geological Survey  

NSDL National Science Digital Library

The North Carolina Geological Survey (NCGS) examines, describes, and maps the state's geology and mineral resources and publishes reports and maps. The site contains lists of publications, maps, aerial photographs, frequently asked questions about North Carolina geology, and mineral and professional information. Project Earth Science is designed to provide relevant and accurate earth science education information for the state's high school students and earth/environmental science teachers.

376

Development of a Two-Phase Structural and Optical Model for Understanding the Fundamental Electrochromic Processes in Amorphous Tungsten Oxide Thin Films  

Microsoft Academic Search

The evolution of a dense columnar morphology with a related void network structure is a natural result of random ballistic aggregation of atoms during the thin film growth process under low adatom mobility conditions. Thin film properties and applications (e.g. magneto-optic materials and a-Si:H solar cells) are often dominated by this anisotropic morphology. Electrochromism is a phenomenon in which the

Howard Stanley Witham

1993-01-01

377

Geologic mapping of Europa  

USGS Publications Warehouse

Galileo data enable the major geological units, structures, and surface features to be identified on Europa. These include five primary units (plains, chaos, band, ridge, and crater materials) and their subunits, along with various tectonic structures such as faults. Plains units are the most widespread. Ridged plains material spans a wide range of geological ages, including the oldest recognizable features on Europa, and appears to represent a style of tectonic resurfacing, rather than cryovolcanism. Smooth plains material typically embays other terrains and units, possibly as a type of fluid emplacement, and is among the youngest material units observed. At global scales, plains are typically mapped as undifferentiated plains material, although in some areas differences can be discerned in the near infrared which might be related to differences in ice grain size. Chaos material is composed of plains and other preexisting materials that have been severely disrupted by inferred internal activity; chaos is characterized by blocks of icy material set in a hummocky matrix. Band material is arrayed in linear, curvilinear, wedge-shaped, or cuspate zones with contrasting albedo and surface textures with respect to the surrounding terrain. Bilateral symmetry observed in some bands and the relationships with the surrounding units suggest that band material forms by the lithosphere fracturing, spreading apart, and infilling with material derived from the subsurface. Ridge material is mapped as a unit on local and some regional maps but shown with symbols at global scales. Ridge material includes single ridges, doublet ridges, and ridge complexes. Ridge materials are considered to represent tectonic processes, possibly accompanied by the extrusion or intrusion of subsurface materials, such as diapirs. The tectonic processes might be related to tidal flexing of the icy lithosphere on diurnal or longer timescales. Crater materials include various interior (smooth central, rough inner, and annular massif) and exterior (continuous ejecta) subunits. Structural features and landforms are shown with conventional symbols. Type localities for the units are identified, along with suggestions for portraying the features on geological maps, including colors and letter abbreviations for material units. Implementing these suggestions by the planetary mapping community would facilitate comparisons of maps for different parts of Europa and contribute to an eventual global synthesis of its complex geology. On the basis of initial mapping results, a stratigraphic sequence is suggested in which ridged plains form the oldest unit on Europa, followed by development of band material and individual ridges. Band materials tend to be somewhat older than ridges, but in many areas the two units formed simultaneously. Similarly, the formation of most chaos follows the development of ridged plains; although chaos is among the youngest materials on Europa, some chaos units might have formed contemporaneously with ridged plains. Smooth plains generally embay all other units and are late-stage in the evolution of the surface. C1 craters are superposed on ridged plains but are crosscut by other materials, including bands and ridges. Most c2 craters postdate all other units, but a few c2 craters are cut by ridge material. C3 craters constitute the youngest recognizable material on Europa. Copyright 2000 by the American Geophysical Union.

Greeley, R.; Figueredo, P. H.; Williams, D. A.; Chuang, F. C.; Klemaszewski, J. E.; Kadel, S. D.; Prockter, L. M.; Pappalardo, R. T.; Head, III, J. W.; Collins, G. C.; Spaun, N. A.; Sullivan, R. J.; Moore, J. M.; Senske, D. A.; Tufts, B. R.; Johnson, T. V.; Belton, M. J. S.; Tanaka, K. L.

2000-01-01

378

Geologic Mapping Exercise  

NSDL National Science Digital Library

This exercise is designed to simulate how a basic geological investigation of a site takes place. A basic geological investigation includes familiarizing yourself with the unconsolidated sediments, rocks, structural geology, and groundwater present at your site. As part of this exercise you will have to properly identify a variety of rock types and sediments, create maps that represent data you collected at each location, and complete a basic report of your findings (optional). Once completed, this exercise should give students a basic understanding of how the various concepts used throughout the semester are applied in the real world in the form of a geological investigation.

Smith, Andrew

379

Contribution of seismic processing to put up the scaffolding for the 3-dimensional study of deep sedimentary basins: the fundaments of trans-national 3D modelling in the project GeoMol  

NASA Astrophysics Data System (ADS)

Within the framework of the transnational project GeoMol geophysical and geological information on the entire Molasse Basin and on the Po Basin are gathered to build consistent cross-border 3D geological models based on borehole evidence and seismic data. Benefiting from important progress in seismic processing, these new models will provide some answers to various questions regarding the usage of subsurface resources, as there are geothermal energy, CO2 and gas storage, oil and gas production, and support decisions-making to national and local administrations as well as to industries. More than 28 000 km of 2D seismic lines are compiled reprocessed and harmonized. This work faces various problems like the vertical drop of more than 700 meters between West and East of the Molasse Basin and to al lesser extent in the Po Plain, the heterogeneities of the substratum, the large disparities between the period and parameters of seismic acquisition, and depending of their availability, the use of two types of seismic data, raw and processed seismic data. The main challenge is to harmonize all lines at the same reference level, amplitude and step of signal processing from France to Austria, spanning more than 1000 km, to avoid misfits at crossing points between seismic lines and artifacts at the country borders, facilitating the interpretation of the various geological layers in the Molasse Basin and Po Basin. A generalized stratigraphic column for the two basins is set up, representing all geological layers relevant to subsurface usage. This stratigraphy constitutes the harmonized framework for seismic reprocessing. In general, processed seismic data is available on paper at stack stage and the mandatory information to take these seismic lines to the final stage of processing, the migration step, are datum plane and replacement velocity. However several datum planes and replacement velocities were used during previous processing projects. Our processing sequence is to first digitize the data, to have them in SEG-Y format. The second step is to apply some post-stack processing to obtain a good data quality before the final migration step. The third step is the final migration, using optimized migration velocities and the fourth step is the post-migration processing. In case of raw seismic data, the mandatory information for processing is made accessible, like from observer logs, coordinates and field seismic data. The processing sequence in order to obtain the final usable version of the seismic line is based on a pre-stack time migration. A complex processing sequence is applied. One main issue is to deal with the significant changes in the topography along the seismic lines and in the first twenty meter layer, this low velocity zone (LVZ) or weathered zone, where some lateral velocity variations occur and disturb the wave propagation, therefore the seismic signal. In seismic processing, this matter is solved by using the static corrections which allow removing these effects of lateral velocity variations and the effects of topography. Another main item is the good determination of root mean square velocities for migration, to improve the final result of seismic processing. Within GeoMol, generalized 3D velocity models of stack velocities are calculated in order to perform a rapid time-depth conversion. In final, all seismic lines of the project GeoMol will be at the same level of processing, the migration level. But to tie all these lines, a single appropriate datum plane and replacement velocity for the entire Molasse Basin and Po Plain, respectively, have to be carefully set up, to avoid misties at crossing points. The reprocessing and use of these 28 000 km of seismic lines in the project GeoMol provide the pivotal database to build a 3D framework model for regional subsurface information on the Alpine foreland basins (cf. Rupf et al. 2013, EGU2013-8924). The project GeoMol is co-funded by the Alpine Space Program as part of the European Territorial Cooperation 2007-2013. The project integrates partners from Austria, France

Capar, Laure

2013-04-01

380

On three-dimensional geological modeling and visualization  

Microsoft Academic Search

The technology of 3D geological modeling will bring about great changes in the methods of geological data acquiring, storing,\\u000a processing and displaying. However, no perfect or convenient software systems have been developed up to now since the geologic\\u000a data which reflect geological entities bear the feature of diversity, uncertainty and complexity. Some super voxel models,\\u000a mathematical models of fault and

Qiang Wu; Hua Xu

2004-01-01

381

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

382

Geology explorer: virtual geologic mapping and interpretation  

NASA Astrophysics Data System (ADS)

We are developing internet-based freeware for virtual mapping and geologic interpretation. This takes the form of a synthetic, virtual world, Planet Oit, where students are given the means and the equipment to carry out geologic investigation and interpretation as a geologist would in the field. The environment is designed to give students an authentic experience that includes elements of: (1) exploration of a spatially oriented, virtual, world; (2) practical, field oriented, expedition planning and decision-making; and (3) scientific problem solving (i.e. a "hands on" approach to mapping, geologic investigation, data acquisition, and interpretation). The game-like environment is networked, multi-player, and simulation-based. Planet Oit can be visited on the Internet at http://oit.cs.ndsu.nodak.edu/

Saini-Eidukat, Bernhardt; Schwert, Donald P.; Slator, Brian M.

2002-12-01

383

Metamorphic and magmatic processes in the central part of the Lapland granulite belt: correlation of geological and petrological study with results of isotopic dating  

NASA Astrophysics Data System (ADS)

Based on geological and petrological study the sequence of magmatic and metamorphic events in the central part of the Lapland granulite belt (the Lotta river area, Kola Peninsula, Russia) has been reconstructed, that allows to reveal physical and chemical conditions of individual episodes in the history of the studied region, and make a correct correlation of petrological data with the results of isotopic dating. It was established that all metapelitic associations found within the studied region, are products of allochemical alterations of "felsic" quartz-feldspar granulites and embedded basic rocks. First granulite moderate-pressure metamorphism (T = 630-730°C, P = 4.0-5.7 kbar) occurred 1.97 -1.96 Ga. The crystallization temperature of metamorphic zircons of this stage (according to Ti contents) is 709-742°C - consistent with petrological data. Basic magmatism - intrusion of small bodies and dykes of gabbro and gabbro-norites took place 1.96 Ga and clearly separates two episodes of granulite facies metamorphism. Granulite HP metamorphism (780-860°C and 6.8-9.5 kbar) and syncollision diathectic S-granitoid formation occurred 1.92-1.91 Ga. The beginning of metamorphism associated with the crystallization of synmetamorphic enderbites - 1929-1925 Ma. The age of metamorphic granulite zircons is 1921-1917 Ma. Crystallization temperature of these zircons is 756-856°C, also consistent with petrological data. Polyphase inclusion in zircons: Kfs + Qtz, Kfs + Qtz + Pl and inclusion of Bt suggest that the formation of zircon occurred simultaneously with the formation of the paragenesis Grt + Bt + Pl + Sil + Qtz (± Kfs). Sm-Nd isochrone for Grt-Cpx-WR-Pl gave an age of 1918 ± 30 Ma. According to petrological data Grt and Cpx growth occurred at isothermal decompression stage with the pressure drop up to 6 kbar. Central parts of clinopyroxene contain up to 10% jadeite component and rims of about 2%. U-Pb garnet age 1925-1932 Ma coincides well with Sm-Nd garnet age. The fact that different minerals and different isotopic systems show the same ages speaks about rapid cooling, when the isotopic system closed soon after mineral formation and the obtained age is crystallization age but not cooling age. Formation of leucogranites as a result of sillimanite-garnet gneiss melting occurred at 1915 -1910 Ma. Zircons in leucogranites contain the same inclusion (Kfs, Sil and Qtz) as granulite zircons, which means, that they have been formed simultaneously with the formation of Sil and the presence of Kfs in paragenesis. Crystallization temperatures of these diathectic zircons - 801-826 ° C overlaps with the crystallization temperature of granulite zircons, as well as an age range of their crystallization. Analysis of the geochemical characteristics of zircons (content and distribution of incompatible elements) and U-Pb dating showed that the formation of granulite and diathectic zircons crystallized from the melt during the same diathectic process. Crystallization temperatures, as determined by Ti contents, are in good agreement with the metamorphic temperatures, defined by generally accepted geothermometers. Isobaric cooling to 657°C and 6.5 kbar in conditions of amphibolite and epidote-amphibolite facies occurred 1912-1906 Ma ago. The final stage of the complex evolution - intrusive granite magmatism (veins and small body of enderbites, granites, plagiopegmatites) was 1.89 -1.88 Ma. The further cooling history of the belt was determined by U-Pb dating of titanites and rutiles (1.88-1.87 Ga) and last low-T hydrothermal alterations are fixed by Rb-Sr system of minerals (1.72 Ga). The work is supported by RFBR grant 07-05-00759

Kaulina, Tatiana; Japaskurt, Vasily; Nerovich, Liudmila

2010-05-01

384

Digital Fundamentals: Course Materials  

NSDL National Science Digital Library

This course provided by eSyst describes digital fundamentals. An introduction explains the traditional view and systems view of this topic. The course includes numerous instructor presentations and student guides. Topics for these include serial digital interfaces, circuit boards, and microprocessors. A detailed course outline, student learning outcomes, and links to additional online resources are also provided. Users must create a free, quick login in order to download the materials.

2012-07-03

385

Redefining the Fundamental Questions  

ERIC Educational Resources Information Center

Every researcher must make some fundamental questions. A researcher's questions should include the following: (1) What is the nature of the reality that I wish to study? (2) How will I know it? (3) What must I do to know it? (4) Who am I? (5) Where is God in this? and (6) For religious educators--How does my research lead to a world of peace and…

Crain, Margaret Ann

2006-01-01

386

The Geological Society of London  

NSDL National Science Digital Library

The Geological Society of London promotes "the geosciences and the professional interests of UK geoscientists." The website offers media, geological, and society news. Researchers can find out about upcoming conferences covering a variety of geological topics as well as information on a series of journals. Everyone interested in geology can find materials on geological careers, including required education, qualifications, and funding. The website provides teaching resources on volcanoes, geologic hazards, and other geological phenomena.

387

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

388

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.; Brownfield, M. E.; Charpentier, Ronald R.; Persits, F. M.; Takahashi, K. I.; Tuttle, M. L.

389

Fundamental study of the NOXSO combined NO/sub x//SO/sub 2/ flue gas treatment process: corrosion and its prevention  

SciTech Connect

The high temperature corrosion behavior (oxidation, sulfidation, and hot corrosion) of a number of Ni-base and Fe-base alloys has been discussed. Ni-base alloys are found to be incompatible with the compounds involved in the NOXSO Process regeneration reactions. Austenitic stainless steels are susceptible to sensitization and to a limited extent, hot corrosion. Type 446 ferritic stainless steel with high Cr content and no Ni performs satisfactorily under the service conditions. Improvement of high temperature corrosion resistance can be achieved by surface coatings such as aluminizing, chromizing, MCrAlY overlay coatings, or ceramic coatings. Aluminized 316L stainless steel has proven effective against the corrosion attack. Other base materials such as low alloy steels, low Cr-content ferritic stainless steels, or low carbon austenitic stainless steels may also be considered, provided good surface coatings are applied. 11 references, 8 figures, 9 tables.

Perng, T.P.

1984-07-31

390

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.

Santamarina, J. Carlos

2013-05-31

391

A program for mass spectrometer control and data processing analyses in isotope geology; written in BASIC for an 8K Nova 1120 computer  

USGS Publications Warehouse

A system is described which uses a minicomputer to control a surface ionization mass spectrometer in the peak switching mode, with the object of computing isotopic abundance ratios of elements of geologic interest. The program uses the BASIC language and is sufficiently flexible to be used for multiblock analyses of any spectrum containing from two to five peaks. In the case of strontium analyses, ratios are corrected for rubidium content and normalized for mass spectrometer fractionation. Although almost any minicomputer would be suitable, the model used was the Data General Nova 1210 with 8K memory. Assembly language driver program and interface hardware-descriptions for the Nova 1210 are included.

Stacey, J. S.; Hope, J.

1975-01-01

392

California Geological Survey - Landslides  

NSDL National Science Digital Library

This page from the CA Geological Survey (CGS) presents information on landslides as well as maps and products of various past and present CGS programs to map and respond to landslides in the state of California, including the Forest and Watershed Geology Program, the Seismic Hazards Zonation Program, the Caltrans Highway Corridor Mapping project, and the Landslide Map Index.

Survey, California G.

393

External Resource: Geologic Time  

NSDL National Science Digital Library

This NASA sponsored webpage, Center for Educational Technologies, teaches students about Geologic Time. The age of Earth is so long compared to all periods of time that we humans are familiar with, it has been given a special name: Geologic time. The age

1900-01-01

394

Interpreting Urban Geology.  

ERIC Educational Resources Information Center

Describes field trips to urban locations for geological instruction. The program was developed by the Cleveland Museum of Natural History. Authors claim these field trips have been an effective and enjoyable way of conveying a wide variety of geological information to participants at all levels and backgrounds and have created favorable publicity.…

Hannibal, Joseph Timothy; Schmidt, Mark Thomas

1991-01-01

395

Marine Geological Discoveries  

NSDL National Science Digital Library

This site by a Norwegian researcher features descriptions of marine geological formations: pockmarks, mud volcanoes, deep-water coral reefs, and gas hydrates. Using ROV technology, he has taken photos of these deep seafloor features, and compares them to geological structures seen on land, and even on the moon.

Hovland, Martin

2010-12-28

396

National Geologic Map Database  

NSDL National Science Digital Library

The National Geologic Map Database (NGMDB) is an Internet-based system for query and retrieval of earth-science map information, created as a collaborative effort between the USGS and the Association of American State Geologists. Its functions include providing a catalog of available map information; a data repository; and a source for general information on the nature and intended uses of the various types of earth-science information. The map catalog is a comprehensive, searchable catalog of all geoscience maps of the United States, in paper or digital format. It includes maps published in geological survey formal series and open-file series, maps in books, theses and dissertations, maps published by park associations, scientific societies, and other agencies, as well as publications that do not contain a map but instead provide a geological description of an area (for example, a state park). The geologic-names lexicon (GEOLEX) is a search tool for lithologic and geochronologic unit names. It now contains roughly 90% of the geologic names found in the most recent listing of USGS-approved geologic names. Current mapping activities at 1:24,000- and 1:100,000-scale are listed in the Geologic Mapping in Progress Database. Information on how to find topographic maps and list of geology-related links is also available.

1997-01-01

397

Geological Time Machine  

NSDL National Science Digital Library

Ride the Web Geological Time Machine at the University of California Museum of Paleontology. Click on an item in the list of 25 geological periods [15 of the 25 periods are available now, the remainder to be completed] and view a page describing each period, its subdivisions, and the life and fossils of that period.

Collins, Allen.

1997-01-01

398

Geologic time scale bookmark  

USGS Publications Warehouse

This bookmark, designed for use with U.S. Geological Survey activities at the 2nd USA Science and Engineering Festival (April 26–29, 2012), is adapted from the more detailed Fact Sheet 2010–3059 "Divisions of Geologic Time." The information that it presents is widely sought by educators and students.

U.S. Geological Survey

2012-01-01

399

People and Geology.  

ERIC Educational Resources Information Center

Provides background information on the many natural resources we extract from the earth's crust, including metals, graphite, and other minerals, as well as fossil fuels. Contains teaching activities such as a geologic scavenger hunt, a geology chronology, and the recycling of aluminum. Includes a reproducible handout for the activity on aluminum.…

Naturescope, 1987

1987-01-01

400

Geologic mapping of Europa  

Microsoft Academic Search

Galileo data enable the major geological units, structures, and surface features to be identified on Europa. These include five primary units (plains, chaos, band, ridge, and crater materials) and their subunits, along with various tectonic structures such as faults. Plains units are the most widespread. Ridged plains material spans a wide range of geological ages, including the oldest recognizable features

Ronald Greeley; Patricio H. Figueredo; David A. Williams; Frank C. Chuang; James E. Klemaszewski; Steven D. Kadel; Louise M. Prockter; Robert T. Pappalardo; James W. Head; Geoffrey C. Collins; Nicole A. Spaun; Robert J. Sullivan; Jeffrey M. Moore; David A. Senske; B. Randall Tufts; Torrence V. Johnson; Michael J. S. Belton; Kenneth L. Tanaka

2000-01-01

401

Glossary of geology  

SciTech Connect

This third edition of the Glossary of Geology contains approximately 37,000 terms, or 1,000 more than the second edition. New entries are especially numerous in the fields of carbonate sedimentology, hydrogeology, marine geology, mineralogy, ore deposits, plate tectonics, snow and ice, and stratigraphic nomenclature. Many of the definitions provide background information.

Bates, R.L.; Jackson, J.A.

1987-01-01

402

Geologic Time Online Edition  

NSDL National Science Digital Library

This tutorial will help students learn and understand the concepts of geologic time and the age of the Earth. They will investigate the geologic time scale and learn about the use of index fossils and radiometric dating to determine the age of rock formations and fossils.

403

Structural Geology Techniques  

NSDL National Science Digital Library

The University of Wisconsin - Green Bay has created this collection of material and instructions on how to analyze and plot structural geology data. Topics covered includes planes, lines, relations between lines and planes, geologic structures, intersection of structures with topography, stereonet techniques, stress and strain, and analysis of complex structures.

Dutch, Steven

2009-05-21

404

Advances in planetary geology  

NASA Technical Reports Server (NTRS)

This second issue in a new series intended to serve the planetary geology community with a form for quick and thorough communications includes (1) a catalog of terrestrial craterform structures for northern Europe; (2) abstracts of results of the Planetary Geology Program, and (3) a list of the photographic holdings of regional planetary image facilities.

Woronow, A. (editor)

1981-01-01

405

Geologic remote sensing  

USGS Publications Warehouse

Remote-sensing techniques are now being used routinely in geologic interpretation for mineral and energy exploration, plant siting, waste disposal, and the development of models for regional and continental tectonics. New spaceborne methods and associated technologies are being developed to produce data from which geologic information about large areas can be derived much more rapidly than by conventional techniques. Copyright ?? 1981 AAAS.

Goetz, A. F. H.; Rowan, L. C.

1981-01-01

406

Women in Early Geology.  

ERIC Educational Resources Information Center

Biographical sketches are given for several women who made early contributions to the science of geology. A short biography of Inge Lehmann is also included as a more recent example of a woman who has made a notable contribution to the geological field. (Author)

Elder, Eleanor S.

1982-01-01

407

Earthquakes and Geology  

NSDL National Science Digital Library

In this activity, students investigate the relationship between intensity of ground motion and type of rock or alluvium, as seen in the 1994 Northridge, California earthquake. They will examine a map of Mercalli intensity, a cross-section showing geologic structures and rock types, and a map of surficial geology, and answer questions pertaining to amplification of ground motion and S-wave velocities.

Ozsvath, David

2011-09-06

408

Dione's spectral and geological properties  

USGS Publications Warehouse

We present a detailed analysis of the variations in spectral properties across the surface of Saturn's satellite Dione using Cassini/VIMS data and their relationships to geological and/or morphological characteristics as seen in the Cassini/ISS images. This analysis focuses on a local region on Dione's anti-saturnian hemisphere that was observed by VIMS with high spatial resolution during orbit 16 in October 2005. The results are incorporated into a global context provided by VIMS data acquired within Cassini's first 50 orbits. Our results show that Dione's surface is dominated by at least one global process. Bombardment by magnetospheric particles is consistent with the concentration of dark material and enhanced CO2 absorption on the trailing hemisphere of Dione independent of the geology. Local regions within this terrain indicate a special kind of resurfacing that probably is related to large-scale impact process. In contrast, the enhanced ice signature on the leading side is associated with the extended ejecta of the fresh impact crater Creusa (???49??N/76??W). Although no geologically active regions could be identified, Dione's tectonized regions observed with high spatial resolution partly show some clean H2O ice implying that tectonic processes could have continued into more recent times. ?? 2009 Elsevier Inc. All rights reserved.

Stephan, K.; Jaumann, R.; Wagner, R.; Clark, R. N.; Cruikshank, D. P.; Hibbitts, C. A.; Roatsch, T.; Hoffmann, H.; Brown, R. H.; Filiacchione, G.; Buratti, B. J.; Hansen, G. B.; McCord, T. B.; Nicholson, P. D.; Baines, K. H.

2010-01-01

409

British Geological Survey: Learning  

NSDL National Science Digital Library

The British Geological Survey (BGS) has a wealth of information about the earth sciences, and they are quite willing to share it with others. This page contains information and resources for anyone interested in geology for educational or leisure purposes, and it is contained with four sections. First up is "Popular geology", which includes "Britain beneath our feet", an interactive atlas of geology, resources, and land quality. This section also contains graphics about climate change and earthquakes. The second section is titled "Educational resources". Here visitors can ask scientists at the BGS specific questions and they can also download several free posters. The third section is called "Educational news and events" and it features upcoming events at the BGS and links to their free magazine, "Earthwise". The site is rounded out by the fourth section titled "From the BGS Archives". Here visitors can view historic geological photographs and also view field sketches and watercolors by Alexander Henry Green, the celebrated Victorian geologist.

410

The Geology of Titan  

NASA Astrophysics Data System (ADS)

Titan, the largest and most complex satellite in the solar system exhibits an organic dominated surface chemistry and shares surface features with other large icy satellites as well as the terrestrial planets. It is subject to tidal stresses, and its surface appears to have been modified tectonically. Cassini's global observations at infrared and radar wavelengths as well as local investigations by the instruments on the Huygens probe has revealed that Titan has the largest known abundance of organic material in the solar system apart from Earth, and that its active hydrological cycle is analogous to that of Earth, but with methane replacing water. The surface of Titan exhibits morphological features of different sizes and origins created by geological processes that span the entire dynamic range of aeolian, fluvial and tectonic activities, with likely evidence that cryovolcanism might exists where liquid water, perhaps in concert with ammonia, methane and carbon dioxide, makes its way to the surface from the interior [e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. Extended dune fields, lakes, mountainous terrain, dendritic erosion patterns and erosional remnants indicate dynamic surface processes. Valleys, small-scale gullies and rounded cobbles require erosion by extended energetic flow of liquids. There is strong evidence that liquid hydrocarbons are ponded on the surface in lakes, predominantly, but not exclusively, at high northern latitudes. A variety of features including extensive flows and caldera-like constructs are interpreted to be cryovolcanic in origin. Chains and isolated blocks of rugged terrain rising from smoother areas are best described as mountains and might be related to tectonic processes. Impact craters form on all solid bodies in the solar system, and have been detected on Titan. But very few have been observed so they must be rapidly destroyed or buried by other geologic processes The morphologies of the impact craters are more similar to those seen on silicate planets than on icy satellites [22]. Removal of impact craters by burial and erosion is likely, given the evidence for fluvial and cryovolcanic processes, and the relatively degraded appearance of hills and ridges. The obvious lack of craters compared with other icy satellites indicates the surface of Titan is young and modified by volcanism and erosion. However, the existence of the large Menrva impact structure (¿400 km in diameter) suggests that in some places larger (and thus potentially older) craters can be preserved [e.g 2, 19, 20, 21, 22, 23]. In general, Titan exhibits a geologically active surface indicating significant endogenic and exogenic processes, with diverse geological, geophysical and atmospheric processes reminiscent of those on Earth [e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. [1] Tomasko et al. 2005, Nature, 438, 765-778; [2] Porco et al. 2005, Nature, 434, 159-168; [3] Sotin et al. 2005, Nature 435, 786-789; [4] Elachi et al. 2005, Science 308, 970-974; [5] Lorenz et al. 2006, Science 312, 724-727; [6] Stofan et al. 2007, Nature,445, doi:10.10338/nature05438; [7] Lopes et al. 2007, Icarus, 186 395-412; [8] Radebaugh et al. 2007, Icarus 192, 77-92; [9] Barnes et al. 2007, JGR 112 E11006; [10] Lorenz et al. 2007, GRL 34, L07204; [11] Soderblom et al., 2007, PSS 55, 2025-2036; [12] Lorenz et al. 2008, PSS56, 1132-1144; [13] Jaumann et al. 2008, Icarus 197, 526-538; [14] Lunine et al. 2008; Icarus 195, 415-433; [15] Jaumann et al., 2009, in Titan from Cassini-Huygens, Brown et al., eds, Springer; [16] Turtle et al. 2009, GRL 36, L02204; [17] Le Corre et al., PSS 54870-879; [18] Stephan et al., 2009, in Titan from Cassini-Huygens, Brown et al., eds, Springer [19] Wood et al., 2007, LPSC, 2118; [20] Lorenz et al., 2007, GRL 34, L07204; [21] LeMouelic, et al., 2008; JGR 113, E04003; [22] Jaumann and Neukum , 2009, LPSC 1641; [23] Wood et al., 2010, Icarus 206, 334-344

Jaumann, Ralf

411

Instrument Control Fundamentals  

NSDL National Science Digital Library

The National Instruments Instrument Control Fundamentals Series, your FREE resource for instrument control knowledge on the Web, presents technical content through theory, real-world examples, and interactive audiovisual tutorials. This series, organized into four general categories, is designed for a broad range of audiences, from experts who want to review a specific topic to new users who need easy-to-understand documentation for their projects. Subtopics include "What is instrument control?" "Instrument Control Hardware and Bus Technologies" "Instrument Control Software" and "Instrument Control System Architectures."

2013-06-21

412

Fundamental experiments in velocimetry  

SciTech Connect

One can understand what velocimetry does and does not measure by understanding a few fundamental experiments. Photon Doppler Velocimetry (PDV) is an interferometer that will produce fringe shifts when the length of one of the legs changes, so we might expect the fringes to change whenever the distance from the probe to the target changes. However, by making PDV measurements of tilted moving surfaces, we have shown that fringe shifts from diffuse surfaces are actually measured only from the changes caused by the component of velocity along the beam. This is an important simplification in the interpretation of PDV results, arising because surface roughness randomizes the scattered phases.

Briggs, Matthew Ellsworth [Los Alamos National Laboratory; Hull, Larry [Los Alamos National Laboratory; Shinas, Michael [Los Alamos National Laboratory

2009-01-01

413

Introduction to petroleum geology. Second edition  

SciTech Connect

This petroleum geology text has been updated to cover the latest developments in structural geology and applied geophysics. This new revision of the second edition brings together a treatment of both the theoretical and the practical aspects of oil and gas geology, explaining the current techniques of geophysical exploration and subsurface reservoir delineation. The latest advances in computerized imaging from remote sensing and satellite transmission mapping processes are provided, and special attention is given to geochemcial aspects of source rock evaluation, maturity analysis, and the evolution of kerogenous materials. The history and classification of sedimentary basing is described in relation to their past and present hydrocarbon contents and the movement of lithospheric ''plates.''

Hobson, G.D.; Tiratsoo, E.N.

1985-01-01

414

Fundamentals of electrokinetics  

SciTech Connect

The study of electrokinetics is a very mature field. Experimental studies date from the early 1800s, and acceptable theoretical analyses have existed since the early 1900s. The use of electrokinetics in practical field problems is more recent, but is still quite mature. Most developments in the fundamental understanding of electrokinetics have been in the colloid science literature. A significant and increasing divergence between the theoretical understanding of electrokinetics found in the colloid science literature and the theoretical analyses used in interpreting applied experimental studies in soil science and waste remediation has developed. The soil science literature has to data restricted itself to the use of very early theories, with their associated limitations. The purpose of this contribution is to review fundamental aspects of electrokinetic phenomena from a colloid science viewpoint. It is hoped that a bridge can be built between the two branches of the literature, from which both will benefit. Attention is paid to special topics such as the effects of overlapping double layers, applications in unsaturated soils, the influence of dispersivity, and the differences between electrokinetic theory and conductivity theory.

Kozak, M.W.

1991-01-01

415

Fundamentals of electrokinetics  

SciTech Connect

The study of electrokinetics is a very mature field. Experimental studies date from the early 1800s, and acceptable theoretical analyses have existed since the early 1900s. The use of electrokinetics in practical field problems is more recent, but is still quite mature. Most developments in the fundamental understanding of electrokinetics have been in the colloid science literature. A significant and increasing divergence between the theoretical understanding of electrokinetics found in the colloid science literature and the theoretical analyses used in interpreting applied experimental studies in soil science and waste remediation has developed. The soil science literature has to data restricted itself to the use of very early theories, with their associated limitations. The purpose of this contribution is to review fundamental aspects of electrokinetic phenomena from a colloid science viewpoint. It is hoped that a bridge can be built between the two branches of the literature, from which both will benefit. Attention is paid to special topics such as the effects of overlapping double layers, applications in unsaturated soils, the influence of dispersivity, and the differences between electrokinetic theory and conductivity theory.

Kozak, M.W.

1991-12-31

416

Essential Elements of Geologic Reports.  

ERIC Educational Resources Information Center

Described is a report outline for geologic reports. Essential elements include title; abstract; introduction; stratigraphy; petrography; geochemistry; petrology; geophysics; structural geology; geologic history; modeling; economics; conclusions; and recommendations. (Author/CW)

Webb, Elmer James

1988-01-01

417

Virtual Tour of Maine Geology  

NSDL National Science Digital Library

This selection of slide shows provides a photographic tour of Maine geology. Users can choose slide shows on surficial, bedrock, and coastal geology; fossils, geologic hazards, groundwater and wells; or mineral collecting, mining, and quarrying.

418

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