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1

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

USGS Publications Warehouse

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

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

2006-01-01

2

Oceanography - Marine Geological Processes  

NSDL National Science Digital Library

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

Mcduff, Russell

3

Proglacial lakes: character, behaviour and geological importance  

NASA Astrophysics Data System (ADS)

Proglacial lakes are ubiquitous within the Quaternary record and can provide exceptional breadth and depth of palaeoenvironmental information. Present deglaciation is increasing the number and size of proglacial lakes around the world. This study provides a synthesis of knowledge on proglacial lake character and behaviour and critically evaluates the importance of proglacial lakes from a geological perspective. We show how 'ice-marginal' or 'ice-contact' lakes and other distal proglacial lakes can be distinguished from each other by geomorphological, sedimentological, chemical and biological characteristics. The key controls on proglacial lake geomorphology and sedimentology are outlined and discussed. Proglacial lakes can exacerbate mountain glacier and ice sheet margin ablation via mechanical and thermal stresses, but very large lakes can moderate summer air temperatures and relatively retard summer ice ablation. Proglacial lakes interrupt meltwater flux and are very efficient sediment traps. Hydrological routing and consequent geomorphological activity can be radically modified by sudden drainage of proglacial lakes and resultant glacial lake outburst floods; exceptionally large proglacial lake drainages affected global ocean circulation and global climate during the Quaternary. Overall, analyses of proglacial lakes can provide a valuable insight into (i) patterns, character and behaviour of mountain glaciers, ice sheets and glaciations, and (ii) the impacts of past, present and future deglaciation.

Carrivick, Jonathan L.; Tweed, Fiona S.

2013-10-01

4

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

5

Comparison Charts of Geological Processes: Terrestrial Planets  

NSDL National Science Digital Library

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

6

Understanding Mars: The Geologic Importance of Returned Samples  

NASA Astrophysics Data System (ADS)

Our current scientific understanding of Mars has been established through a systematic sequence of missions, beginning 45 years ago with flybys, and followed by reconnaissance from orbiters and landers, detailed mapping from highly sophisticated orbiters, and, most recently, rovers that are capable of true geologic and geochemical exploration. The past fifteen years of intense exploration has revolutionized our knowledge and understanding of Mars, changing our view of Mars from a cold, dry planet in which the activity occurred billions of years ago, to one with an extensive inventory of near-surface snow and ice, recently-active aqueous processes, and a remarkable diversity of aqueous environments that show evidence for major differences in aqueous chemistry, conditions, and processes. The bulk of this knowledge has come from the analysis of global remote sensing data, which have provided elemental and mineralogic composition maps, morphology at sub-meter resolution, and information on the physical properties of the regolith. While these remote data sets provide a wealth of insight into past and present surface process, they are limited in the detection of potentially important minor phases, and cannot provide details at spatial scales that are often necessary to understand the details of formation mechanisms. The MER rovers demonstrated the tremendous utility of in situ investigations to ground truth the global remote sensing, and in many cases confirmed the discoveries from orbit. However, even in situ observations are limited, with severe restrictions on the set of experiments that can be performed because of the difficulty of miniaturizing state-of-the-art analytical tools within limited rover payload capacity. The recently published NRC Planetary Science Decadal Survey Report placed pursuing the questions of habitability and the potential origin and evolution of life on Mars as the highest priority Mars science goal. Among the key questions to be studied are what are the nature, ages, and origin of the diverse suite of aqueous environments, were any of them habitable, how, when, and why did environments vary through time, and finally, did any of them host life or its precursors? A critical next step toward answering these questions would be provided through the analysis of carefully selected samples from geologically diverse and well-characterized sites that are returned to Earth for detailed study. This sample return campaign is envisioned as a sequence of three missions that collect the samples, place them into Mars orbit, and return them to Earth. Our existing scientific knowledge of Mars makes it possible to select a site at which specific, detailed hypotheses can be tested, and from which the orbital mapping can be validated and extended globally. Existing and future analysis techniques developed in laboratories around the world will provide the means to perform a wide array of tests on these samples, develop hypotheses for the origin of their chemical, isotopic, and morphologic signatures, and, most importantly, perform follow-up measurements to test and validate the findings. These analyses will dramatically improve our understanding of the geologic processes and history of Mars, and through their ties to the global geologic context, will once again revolutionize our understanding of this complex planet.

Christensen, P. R.

2011-12-01

7

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

8

Geologic processes influence the effects of mining on aquatic ecosystems.  

PubMed

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

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

2012-04-01

9

A MAP OF IMPORTANT GEOLOGICAL SITES OF SLOVAKIA  

Microsoft Academic Search

The Landscape Atlas of the Slovak Republic is being prepared at the Ministry of the Environment of the Slovak Republic comprising also geological aspects of the environment. The map of geological curiosities at 1 : 1 000 000 scale is the compound of the chapter 8 devoted to protected territories and natural resources (responsible editor: RNDr. Tatiana Hrn?iarová, CSc.). Geological

P. LIŠ?ÁK; M. POLÁK; I. BARÁTH

10

Importance of Charles Lyell’s works for the formation of scientific geological ideology  

Microsoft Academic Search

Ch. Lyell’s works, the main work among which entitled Principles of Geology was published 180 years ago in 1830, created a new concept and laid the groundwork for modern geological science, methods\\u000a for the study of geological processes and geological history based on the investigation of recent environments and processes.\\u000a These propositions with natural corrections are also used in geological

V. G. Kuznetsov

2011-01-01

11

Image processing applications for geologic mapping  

SciTech Connect

The use of satellite data, particularly Landsat images, for geologic mapping provides the geologist with a powerful tool. The digital format of these data permits applications of image processing to extract or enhance information useful for mapping purposes. Examples are presented of lithologic classification using texture measures, automatic lineament detection and structural analysis, and use of registered multisource satellite data. In each case, the additional mapping information provided relative to the particular treatment is evaluated. The goal is to provide the geologist with a range of processing techniques adapted to specific mapping problems.

Abrams, M.; Blusson, A.; Carrere, V.; Nguyen, T.; Rabu, Y.

1985-03-01

12

How does surface life affect interior geological processes?  

Microsoft Academic Search

How does surface life affect interior geological processes? We propose that biologically-mediated processes operating on the surface of the Earth need to be incorporated into our understanding of the geological evolution of the Earth. We argue that biotic effects may penetrate the lithosphere and be responsible for altering the dynamics of mantle convection. Geological processes have played a fundamental role

James Dyke; Fabian Gans; Axel Kleidon

2010-01-01

13

Importance of Processing Plant Information  

EIA Publications

This presentation provides information about the importance of information about natural gas processing plants, particularly during periods of natural gas supply disruption, such as hurricanes. It also provides information about a relatively new survey instrument to collect information from natural gas processing plants during non-emergency and supply-emergency conditions.

Information Center

2009-06-22

14

Planetary Geology: Impact Processes on Asteroids.  

National Technical Information Service (NTIS)

The fundamental geological and geophysical properties of asteroids were studied by theoretical and simulation studies of their collisional evolution. Numerical simulations incorporating realistic physical models were developed to study the collisional evo...

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

1982-01-01

15

3-D visualization of geologic structures and processes  

NASA Astrophysics Data System (ADS)

Interactive 3-D computer graphics techniques are used to visualize geologic structures and simulated geologic processes. Geometric models that serve as input to 3-D viewing programs are generated from contour maps, from serial sections, or directly from simulation program output. Choice of viewing parameters strongly affects the perception of irregular surfaces. An interactive 3-D rendering program and its graphical user interface provide visualization tools for structural geology, seismic interpretation, and visual post-processing of simulations. Dynamic display of transient ground-water simulations and sedimentary process simulations can visualize processes developing through time.

Pflug, R.; Klein, H.; Ramshorn, Ch.; Genter, M.; Stärk, A.

16

The geological thought process: A help in developing business instincts  

SciTech Connect

Since the beginning of modern-day geology it has been understood that the present is the key to the past. However, when attempting to apply current geological models one discovers that there are no exact look-alikes. Thus, the geological discipline inherently accepts modifications, omissions, and relatively large margins of error compared with engineering. Geologists are comfortable in a world of non-unique solutions. Thus the experience in working with numerous geological settings is extremely critical in selecting the most reasonable geological interpretations, often by using a composite of specific models. One can not simply replace a dynamic geologist`s life-time of experiences and geologic instinct with simply a book-smart young upstart. Petroleum corporations accept geologic risk and manage it by drilling numerous wells in various geological provenances. Oil corporations have attempted to quantify and manage risk by using Monte Carlo simulations, thus invoking a formal discipline of risk. The acceptance of risk, results in an asset allocation approach to investing. Asset allocators attempt to reduce volatility and risk, inherently understanding that in any specific time interval anything can happen. Dollar cost averaging significantly reduces market risk over time, however it requires discipline and commitment. The single most important ingredient to a successful investing plan is to assign a reasonable holding period. Historically, a majority of the investment community demands instant gratification causing unneeded anxiety and failure. As in geology nothing can replace experience.

Epstein, S.A. [Dean Witter Reynolds, New York, NY (United States)

1995-09-01

17

The Moon: Keystone To Understanding Planetary Geological Processes and History  

NASA Astrophysics Data System (ADS)

Extensive and intensive exploration of the Earth's Moon by astronauts and an interna- tional array of automated spacecraft provides data on geology, geochemistry, miner- alogy, petrology, chronology, geophysics and internal structure unequaled except for Earth. This level of detail has proven fundamental to understanding planetary surface processes and evolution, and is essential to linking surface processes with internal and thermal evolution. On the basis of these data, the Moon is a laboratory for under- standing of planetary processes and a keystone for providing evolutionary perspective. Important comparative planetology issues being addressed by lunar studies include- Impact cratering: New information on the nature of the process, depth of excavation, role of oblique impact, nature of the modification stage, production of impact melt, ejecta emplacement dynamics, the role of volatile emplacement and fate, particularly at the poles, and the establishment of crater size-frequency distribution chronology. Magmatic activity: New insight into plutonism (intrusion) and volcanism (extrusion), and their role as major crustal building and resurfacing processes throughout history, as well as the distribution of mantle melting processes in space and time. The nature of magmatic activity during heavy bombardment (intrusion, extrusion, cryptomaria) and in later lunar history, in terms of the mare stratigraphic record, the distribution of basalt types, the distribution of melting in space and time, volume and flux informa- tion, and the full range of eruption styles and their petrogenetic significance. Tectonic activity: The Moon is the type location for tectonics on a one-plate planet which can be understood in the context of the complete lunar data set and extended to other planetary bodies. Issues include distinguishing magmatic and tectonic graben, estab- lishing the three-dimensional structure and chronology of wrinkle ridges and arches, determining the internal structure of mountain ranges and linking these events to lunar thermal evolution. Upcoming missions by ESA and Japan will provide important ad- ditional insight into a host of comparative planetological problems, including: Decon- volution of the complex record of early lunar crustal formation and evolution, relation of geological processes to the thermal evolution of the Moon and one-plate planets, establishment of a key planetary perspective on the first half of Solar System history, and extrapolation to the nature and evolution of terrestrial planetary bodies including Earth.

Head, J. W.

18

Importance of surface geologic condition in regulating As concentration of groundwater in the alluvial plain.  

PubMed

The arsenic (As) concentrations in the groundwater of alluvial plains generally show high spatial variability. We geochemically explore the factors causing the spatial variability in an alluvial plain that is mainly used for rice cultivation, the commonest land-use pattern in alluvial plains of Asia. We investigate the chemical processes, sources of chemicals that affect the behavior of As, and their relationships with the geologic conditions at seven multilevel sampler sites. All sites showed As concentrations that increased with depth at shallow levels and decreased at greater depths, which is the typical vertical pattern in alluvial aquifers where Fe-(hydr)oxide reduction is the major As release mechanism. Data show that NO(3) and SO(4) originating from the land surface play important roles in suppressing the increase in As concentration by buffering the redox potential at shallow depths and by precipitating As with sulfide minerals at deep depths, respectively. The As concentration in the intermediate depth range was also low in the presence of SO(4), because its reduction can occur together with Fe-(hydr)oxide reduction in a wide range of redox potentials. As a result, the maximum As concentrations at the sites where the land was covered with a thick silt layer (approximately 5m) were 3- to 5-times higher than those at other sites due to the supply of NO(3) and SO(4) from land surface being largely limited by the silt layer. This indicates that the surface geology could be an important indicator for the As concentration in alluvial groundwater. PMID:19699509

Kim, Kangjoo; Moon, Jeung-Tae; Kim, Seok-Hwi; Ko, Kyung-Seok

2009-08-21

19

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

20

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

NASA Astrophysics Data System (ADS)

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

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

2008-09-01

21

Geology.  

National Technical Information Service (NTIS)

Geologic history and geographic distribution of Central New York's surface and subsurface mineral resources are described. Present and potential economic uses are identified; abandoned, semi-active, and active extraction sites are depicted; and resources ...

J. F. Davis

1970-01-01

22

Graphics processing, video digitizing, and presentation of geologic information  

SciTech Connect

Computer users have unparalleled opportunities to use powerful desktop computers to generate, manipulate, analyze and use graphic information for better communication. Processing graphic geologic information on a personal computer like the Amiga used for the projects discussed here enables geoscientists to create and manipulate ideas in ways once available only to those with access to large budgets and large mainframe computers. Desktop video applications such as video digitizing and powerful graphic processing application programs add a new dimension to the creation and manipulation of geologic information. Videotape slide shows and animated geology give geoscientists new tools to examine and present information. Telecommunication programs such as ATalk III, which can be used as an all-purpose telecommunications program or can emulate a Tektronix 4014 terminal, allow the user to access Sun and Prime minicomputers and manipulate graphic geologic information stored there. Graphics information displayed on the monitor screen can be captured and saved in the standard Amiga IFF graphic format. These IFF files can be processed using image processing programs such as Butcher. Butcher offers edge mapping, resolution conversion, color separation, false colors, toning, positive-negative reversals, etc. Multitasking and easy expansion that includes IBM-XT and AT co-processing offer unique capabilities for graphic processing and file transfer between Amiga-DOS and MS-DOS. Digital images produced by satellites and airborne scanners can be analyzed on the Amiga using the A-Image processing system developed by the CSIRO Division of Mathematics and Statistics and the School of Mathematics and Computing at Curtin University, Australia.

Sanchez, J.D. (Geological Survey, Denver, CO (USA))

1990-02-01

23

Elucidating geological and biological processes underlying the diversification of Sulawesi tarsiers  

Microsoft Academic Search

Because of their exceptionally long independent evolution, a range diminution of their Eocene relatives, and a remarkable subsequent diversification in Southeast Asia, tarsiers are of particular importance to evolutionary primatologists. Little is known, however, on the processes shaping the radiation of these small enigmatic primates---especially on the Indonesian island of Sulawesi, their center of endemism. Geological reconstructions and progress in

Stefan Merker; Christine Driller; Dyah Perwitasari-Farajallah; Joko Pamungkas; Hans Zischler

2009-01-01

24

Geologic input to work processes at Duri Field, Indonesia  

SciTech Connect

Dud Field, central Sumatra, Indonesia, at 300,000 bbls per day from over 3000 wells is considered the world's largest steamflood. A project of this magnitude presents significant challenges during the planning, implementation, and operational phases. One of the biggest challenges was to increase the amount of geological data being used in decisions made on a daily basis in operations. This paper will focus on the contributions made by geologists to pattern analysis, a key process within the now, cross-functional, Asset Management Teams. The geological contribution to pattern analysis is zone correlation, geostatistical modeling, and establishment of flow units on a pattern basis. The tools necessary for the effort include statistics, formation evaluation, post steam resistivity logs, computer mapping (reserves, kh, Phi-H-So, transmissivity, 4D seismic). All applied on a pattern area to layers (15 acre patterns, 5-8 layers per pattern). The geology products are now integrated with other information, (temperature surveys, krypton surveys, PNC logs, well head temperatures, liner damage image), all previously used with little geology input. Each AMT is responsible for approximately 150-200 patterns and each pattern must be reviewed twice a year. Each work day of the year, up to 24 wells and all new data are reviewed. The pace of work requires dependable, easily communicated analyses. Estimates that this layer management of the steamflood increases the recovery efficiency by 5% at a minimum, a potential increase in reserves of 500 million barrels.

Primadi, H.; Jackson, W.D.; McNaboe, G.J.; Bamahry, L. (and others)

1996-01-01

25

Multi-scale interactions of geological processes during mineralization: cascade dynamics model and multifractal simulation  

NASA Astrophysics Data System (ADS)

Relations between mineralization and certain geological processes are established mostly by geologist's knowledge of field observations. However, these relations are descriptive and a quantitative model of how certain geological processes strengthen or hinder mineralization is not clear, that is to say, the mechanism of the interactions between mineralization and the geological framework has not been thoroughly studied. The dynamics behind these interactions are key in the understanding of fractal or multifractal formations caused by mineralization, among which singularities arise due to anomalous concentration of metals in narrow space. From a statistical point of view, we think that cascade dynamics play an important role in mineralization and studying them can reveal the nature of the various interactions throughout the process. We have constructed a multiplicative cascade model to simulate these dynamics. The probabilities of mineral deposit occurrences are used to represent direct results of mineralization. Multifractal simulation of probabilities of mineral potential based on our model is exemplified by a case study dealing with hydrothermal gold deposits in southern Nova Scotia, Canada. The extent of the impacts of certain geological processes on gold mineralization is related to the scale of the cascade process, especially to the maximum cascade division number nmax. Our research helps to understand how the singularity occurs during mineralization, which remains unanswered up to now, and the simulation may provide a more accurate distribution of mineral deposit occurrences that can be used to improve the results of the weights of evidence model in mapping mineral potential.

Yao, L.; Cheng, Q.

2011-03-01

26

Using Springs to Study Groundwater Flow and Active Geologic Processes  

NASA Astrophysics Data System (ADS)

Spring water provides a unique opportunity to study a range of subsurface processes in regions with few boreholes or wells. However, because springs integrate the signal of geological and hydrological processes over large spatial areas and long periods of time, they are an indirect source of information. This review illustrates a variety of techniques and approaches that are used to interpret measurements of isotopic tracers, water chemistry, discharge, and temperature. As an example, a set of springs in the Oregon Cascades is considered. By using tracers, temperature, and discharge measurements, it is possible to determine the mean-residence time of water, infer the spatial pattern and extent of groundwater flow, estimate basin-scale hydraulic properties, calculate the regional heat flow, and quantify the rate of magmatic intrusion beneath the volcanic arc.

Manga, Michael

27

New developments in use of image processing for integrated geological and geophysical data evaluation  

SciTech Connect

Interactive work stations for seismic interpretation and mapping have been available for several years. Geological interpretation and display systems have also been available, but separate from the seismic interpretation work station. The need for integrated geological and geophysical systems is now greater than ever. The limits between the geologist's and geophysicist's work is overlapping more and more. The title explorationist would nowadays be more characteristic. In this paper, a system for integrated geological and geophysical interpretation and presentation using image processing will be presented. Integration of well data such as VSP, synthetic seismograms, electric logs, and stratigraphic logs with seismic data is important for the best correlation between wells and seismic. Composite displays and data bases present a unique way of doing this using an image processor. Seismic interpretation is often based on a previously defined geological model; therefore, it is important to be able to compare seismic interpretation with the geological model and vice versa. A new method of using image processing in depth conversion on either a single seismic line or on a map using a flexible velocity field will present the explorationist with instant ways to verify the interpretation. Once an interpretation is performed, the interpreted horizons can be used as input to a geophysical 3D seismic modeling concept. The user can input survey parameters as they were used during acquisition to produce synthetic seismograms and compare results with existing seismic data. When depth conversion parameters are established, the image processor performs this within seconds, and the final depth map is presented to the explorationist.

Miller, P.F.

1987-05-01

28

Analysis of Geological Structures  

Microsoft Academic Search

A knowledge of structural geology is fundamental to understanding the processes by which the earth's crust has evolved. It is a subject of fundamental importance to students of geology, experienced field geologists and academic researchers as well as to petroleum and mining engineers. In contrast to many structural textbooks which dwell upon geometrical descriptions of geological structures, this book emphasises

Neville J. Price; John W. Cosgrove

1990-01-01

29

Hydraulic lift: a potentially important ecosystem process.  

PubMed

Hydraulic lift is the process by which some deep-rooted plants take in water from lower soil layers and exude that water into upper, drier soil layers. Hydraulic lift is beneficial to the plant transporting the water, and may be an important water source for neighboring plants. Recent evidence shows that hydraulically lifted water can promote greater plant growth, and could have important implications for net primary productivity, as well as ecosystem nutrient cycling and water balance. PMID:21238277

Horton, J L; Hart, S C

1998-06-01

30

Hydraulic lift: a potentially important ecosystem process  

Microsoft Academic Search

Hydraulic lift is the process by which some deep-rooted plants take in water from lower soil layers and exude that water into upper, drier soil layers. Hydraulic lift is beneficial to the plant transporting the water, and may be an important water source for neighboring plants. Recent evidence shows that hydraulically lifted water can promote greater plant growth, and could

Jonathan L. Horton; Stephen C. Hart

1998-01-01

31

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

32

Process for structural geologic analysis of topography and point data  

DOEpatents

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

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

1987-01-01

33

Impact craters: their importance in geologic record and implications for natural resource development  

SciTech Connect

Impacting bodies of sufficient size traveling at hypervelocities carry tremendous potential energy. This relatively infrequent process results in the instantaneous formation of unique structures that are characterized by extensive fracturing and brecciation of the target material. Impacts onto continental shield areas can create rich ore deposits, such as the Sudbury mining district in Canada. Impacts into the sedimentary column can instantaneously create hydrocarbon reservoirs out of initially nonporous rocks, such as at Red Wing Creek and Viewfield in the Williston basin. Associated reservoirs are usually limited to a highly deformed central uplift in larger craters, or to the fractured rim facies in smaller craters. The presence of reservoirs and trapping mechanisms is largely dependent, however, upon the preservation state of the crater in the subsurface. A catastrophic extraterrestrial event (a large asteroid impact) has also been suggested as the cause for the extinction of the dinosaurs, but the latest theory proposes a companion star with a 26 m.y. periodicity as the cause for numerous lifeform extinctions over a similar time interval. Regardless of their magnitude and distribution over the earth, it is clear that catastrophic extraterrestrial events have been responsible for altering the geologic column locally, regionally, and quite possibly on a global scale.

Levie, D. Jr.

1986-05-01

34

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

Microsoft Academic Search

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

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

2002-01-01

35

A Topologically-based Framework for Simulating Complex Geological Processes  

Microsoft Academic Search

Earth scientists acquire and interpret a variety of data in an attempt to define the best description of subsurface geological structures, or an earth model, as the data permit. The generation of numerical meshes derived from an earth model is a necessary critical step to provide specific data representations such as finite difference grids or finite element meshes, including the

Ulisses T. Mello; Paulo R. Cavalcanti

1998-01-01

36

Influences of geomorphology and geology on alpine treeline in the American West - More important than climatic influences?  

USGS Publications Warehouse

The spatial distribution and pattern of alpine treeline in the American West reflect the overarching influences of geological history, lithology and structure, and geomorphic processes and landforms, and geologic and geomorphic factors - both forms and processes - can control the spatiotemporal response of the ecotone to climate change. These influences occur at spatial scales ranging from the continental scale to fine scale processes and landforms at the slope scale. Past geomorphic influences, particularly Pleistocene glaciation, have also left their impact on treeline, and treelines across the west are still adjusting to post-Pleistocene conditions within Pleistocene-created landforms. Current tine scale processes include solifluction and changes on relict solifluction and digging by animals. These processes should be examined in detail in future studies to facilitate a better understanding of where individual tree seedlings become established as a primary response of the ecotone to climate change. Copyright ?? 2007 by Bellwether Publishing, Ltd. All rights reserved.

Butler, D. R.; Malanson, G. P.; Walsh, S. J.; Fagre, D. B.

2007-01-01

37

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

SciTech Connect

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

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

1996-01-01

38

Processive phosphorylation: mechanism and biological importance  

PubMed Central

Recent proteomic data indicate that a majority of the phosphorylated proteins in a eucaryotic cell contain multiple sites of phosphorylation. In many signaling events, a single kinase phosphorylates multiple sites on a target protein. Processive phosphorylation occurs when a protein kinase binds once to a substrate and phosphorylates all of the available sites before dissociating. In this review, we discuss examples of processive phosphorylation by serine/threonine kinases and tyrosine kinases. We describe current experimental approaches for distinguishing processive from non-processive phosphorylation. Finally, we contrast the biological situations that are suited to regulation by processive and non-processive phosphorylation.

Patwardhan, Parag; Miller, W. Todd

2007-01-01

39

Geology Field Trips as Performance Evaluations  

ERIC Educational Resources Information Center

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

Bentley, Callan

2009-01-01

40

Rainwater as a chemical agent of geologic processes; a review  

USGS Publications Warehouse

Chemical analyses of the rainwater collected at several localities are given to show the variations of the principal constitutents. In rock weathering and soil-forming processes, the chemical composition of rainwater has an important effect which has been evaluated for only a few arid areas. In humid regions the important amounts of calcium, magnesium, sodium, and potassium added yearly by rain may be expected to influence the composition of the soil water and thereby the cations in the exchange positions of soil clay minerals. The acquisition of cations by clay minerals may slow down chemical weathering. The stability of soil clay minerals is influenced by the constant accession of cations from rainwater. Conversely, the clay minerals modify the amounts and kinds of cations that are leached out by drainage waters. The stability of micaceous minerals in soils may be partly due to accessions of K +1 ions from rainwater. The pH of rainwater in any area varies considerably and seems to form a seasonal and regional pattern. The recorded pH values range from 3.0 to 9.8.

Carroll, Dorothy

1962-01-01

41

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

42

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

43

Important geological and biological impacts of natural hydrocarbon seeps: Northern Gulf of Mexico continental slope  

SciTech Connect

Large volumes of siliciclastic sediments, input especially during periods of lowered sea level, and compensating salt tectonics have produced a continental slope that is arguably the most complex in today's oceans. Faults associated with deformation of salt and shale provide the primary migration routes for hydrocarbon gases, crude oil, brines, and formation fluids to the modern sea floor. Since the mid 1980s, it has become increasingly clearer that this process has an extremely important impact on the geomorphology, sedimentology, and biology of the modern continental slope. Hydrocarbon source, flux rate, and water depth are important determinants of sea-floor response. Under rapid flux conditions mud volcanoes (to 1 km wide and 50 m high) result, and hydrate hills (rich with authigenic carbonates), carbonate lithoherms, and isolated communities of chemosymbiotic organisms with associated hardgrounds represent much slower flux responses. In numerous moderate- to low-flux cases, cold seep products function to support islands of productivity for communities of chemosymbiotic organisms that contribute both directly (shell material) and through chemical byproducts to the production of massive volumes of calcium-magnesium carbonate in the form of hardgrounds, stacked slabs, and discrete moundlike buildups (commonly >20m). Seep-related carbonates of the Gulf of Mexico continental slope, as well those formed through degassing of accretionary prisms along active margins, are now thought to create hardgrounds and discrete buildups that are excellent analogs for many problematic carbonate buildups in ancient deep-water siliciclastic rocks.

Roberts, H.H. (Louisiana State Univ., Baton Rouge, LA (United States))

1993-11-01

44

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

45

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.

46

Importance of quantum decoherence in brain processes  

NASA Astrophysics Data System (ADS)

Based on a calculation of neural decoherence rates, we argue that the degrees of freedom of the human brain that relate to cognitive processes should be thought of as a classical rather than quantum system, i.e., that there is nothing fundamentally wrong with the current classical approach to neural network simulations. We find that the decoherence time scales (~10-13-10-20 s) are typically much shorter than the relevant dynamical time scales (~10-3-10-1 s), both for regular neuron firing and for kinklike polarization excitations in microtubules. This conclusion disagrees with suggestions by Penrose and others that the brain acts as a quantum computer, and that quantum coherence is related to consciousness in a fundamental way.

Tegmark, Max

2000-04-01

47

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

48

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

49

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

NASA Astrophysics Data System (ADS)

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 from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life's ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes.

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

2011-06-01

50

Theoretical prediction for several important equilibrium Ge isotope fractionation factors and geological implications  

NASA Astrophysics Data System (ADS)

This study estimates equilibrium fractionation factors in the Ge isotope system, including the dominant aqueous Ge(OH)4 and GeO(OH)3- species in seawater, Ge-bearing organic complexes (e.g. Ge-catechol, Ge-oxalic acid and Ge-citric acid), and Ge in quartz- (or opal-), albite-, K-feldspar-, olivine- and sphalerite-like structures. Estimations are based on Urey model (or Bigeleisen-Mayer equation) and high level quantum chemistry calculations. All calculations are made at B3LYP/6-311 + G(d,p) theory level. Solvation effects are treated by explicit solvent model (“water-droplet” method), and mineral structures are simulated using cluster models, in which the clusters are cut from the X-ray structures of those minerals. In addition, a number of different conformers are used for aqueous complexes in order to reduce the possible errors coming from the differences of configurations in solution. The “salt effect” on GeO(OH)3-(aq) species is also carefully evaluated. We estimate the accuracy of these fractionation calculations at about ± 0.3‰. Excitedly, very large isotope fractionations are found between many Ge isotope systems. The Ge-containing sulfides (e.g. sphalerite) can extremely enrich light Ge isotopes (more than 10‰) compared with 4-coordinated Ge-O compounds (e.g. Ge(OH)4(aq) or quartz). The fractionations between Ge(OH)4(aq) and 6-coordinated Ge-bearing organic complexes can be also up to 4‰ at 25 °C. These results give a good explanation for the experimental observations of Rouxel et al. (2006). It also suggests a great potential for broad application of Ge isotope method in various geological systems.

Li, Xuefang; Zhao, Hui; Tang, Mao; Liu, Yun

2009-09-01

51

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

52

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

53

Applying Seismic Methods to National Security Problems: Matched Field Processing With Geological Heterogeneity  

Microsoft Academic Search

Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to

S Myers; S Larsen; J Wagoner; B Henderer; D McCallen; J Trebes; P Harben; D Harris

2003-01-01

54

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

55

Elucidating geological and biological processes underlying the diversification of Sulawesi tarsiers.  

PubMed

Because of their exceptionally long independent evolution, a range diminution of their Eocene relatives, and a remarkable subsequent diversification in Southeast Asia, tarsiers are of particular importance to evolutionary primatologists. Little is known, however, on the processes shaping the radiation of these small enigmatic primates-especially on the Indonesian island of Sulawesi, their center of endemism. Geological reconstructions and progress in applying DNA sequence information to divergence dating now provide us with the tools and background to comprehend tarsier dispersal. Here, we describe effects of plate-tectonic movements, Pleistocene sea level changes, and hybridization on the divergence of central Sulawesi tarsiers. We analyzed 12 microsatellites, the cytochrome b gene, the hypervariable region I of the mitochondrial control region, and the sex-determining region on the Y-chromosome from 144 specimens captured along a transect crossing a species boundary and a contact zone between 2 microplates. Based on these differentially inherited genetic markers, geographic information, and recordings of vocalizations, we demonstrate that the species boundary coincides with a tectonic suture. We estimate the most recent common ancestor of the 2 taxa to have lived 1.4 Mya, we describe asymmetrical introgressive hybridization, and we give evidence of unbiased dispersal in one species and male-biased dispersal in another species. This study exemplifies that the distribution of tarsier acoustic forms on Sulawesi is consistent with the allocation of genetic variability and that plate-tectonic and glacial events have left traceable marks in the biogeography of this island's unique fauna. PMID:19451646

Merker, Stefan; Driller, Christine; Perwitasari-Farajallah, Dyah; Pamungkas, Joko; Zischler, Hans

2009-05-18

56

Elucidating geological and biological processes underlying the diversification of Sulawesi tarsiers  

PubMed Central

Because of their exceptionally long independent evolution, a range diminution of their Eocene relatives, and a remarkable subsequent diversification in Southeast Asia, tarsiers are of particular importance to evolutionary primatologists. Little is known, however, on the processes shaping the radiation of these small enigmatic primates—especially on the Indonesian island of Sulawesi, their center of endemism. Geological reconstructions and progress in applying DNA sequence information to divergence dating now provide us with the tools and background to comprehend tarsier dispersal. Here, we describe effects of plate-tectonic movements, Pleistocene sea level changes, and hybridization on the divergence of central Sulawesi tarsiers. We analyzed 12 microsatellites, the cytochrome b gene, the hypervariable region I of the mitochondrial control region, and the sex-determining region on the Y-chromosome from 144 specimens captured along a transect crossing a species boundary and a contact zone between 2 microplates. Based on these differentially inherited genetic markers, geographic information, and recordings of vocalizations, we demonstrate that the species boundary coincides with a tectonic suture. We estimate the most recent common ancestor of the 2 taxa to have lived 1.4 Mya, we describe asymmetrical introgressive hybridization, and we give evidence of unbiased dispersal in one species and male-biased dispersal in another species. This study exemplifies that the distribution of tarsier acoustic forms on Sulawesi is consistent with the allocation of genetic variability and that plate-tectonic and glacial events have left traceable marks in the biogeography of this island's unique fauna.

Merker, Stefan; Driller, Christine; Perwitasari-Farajallah, Dyah; Pamungkas, Joko; Zischler, Hans

2009-01-01

57

CO 2 Injection in Geological Formations: Determining Macroscale Coefficients from Pore Scale Processes  

Microsoft Academic Search

Carbon dioxide (CO2) injections in geological formations are usually performed for enhanced hydrocarbon recovery in oil and gas reservoirs and\\u000a storage and sequestration in saline aquifers. Once CO2 is injected into the formation, it propagates in the porous rock by dispersion and convection. Chemical reactions between\\u000a brine ions and CO2 molecules and consequent reactions with mineral grains are also important

F. Javadpour

2009-01-01

58

Geological Survey of Canada, Geodynamics Program: Earthquake Processes: Cascadia Subduction Zone  

NSDL National Science Digital Library

This page explains the tectonic setting of the west coast of North America. It explains the process of the subduction of the Juan de Fuca plate beneath the North American plate. It describes the methods used to observe tectonic deformation caused by subduction, and explains how they are used to estimate earthquake potential in the region. Links are provided to the Geological Survey of Canada's Geodynamics Program home page, and to their Pacific Geoscience Centre page.

59

Effect of strong heterogeneity on the onset of convection in a porous medium: Importance of spatial dimensionality and geologic controls  

Microsoft Academic Search

The effect of strong heterogeneity on the onset of convection induced by a vertical density gradient in a saturated heterogeneous porous medium governed by Darcy's law is investigated. A computer package has been developed to study the applicability of an average Rayleigh number as a criterion for the onset of convection in strongly heterogeneous geologic media. The heterogeneous geologic media

Craig T. Simmons; A. V. Kuznetsov; D. A. Nield

2010-01-01

60

Differential preservation in the geologic record of intraoceanic arc sedimentary and tectonic processes  

NASA Astrophysics Data System (ADS)

Records of ancient intraoceanic arc activity, now preserved in continental suture zones, are commonly used to reconstruct paleogeography and plate motion, and to understand how continental crust is formed, recycled, and maintained through time. However, interpreting tectonic and sedimentary records from ancient terranes after arc-continent collision is complicated by preferential preservation of evidence for some arc processes and loss of evidence for others. In this synthesis we examine what is lost, and what is preserved, in the translation from modern processes to the ancient record of intraoceanic arcs. Composition of accreted arc terranes differs as a function of arc-continent collision geometry. 'Forward-facing' collision can accrete an oceanic arc on to either a passive or an active continental margin, with the arc facing the continent and colliding trench- and forearc-side first. In a 'backward-facing' collision, involving two subduction zones with similar polarity, the arc collides backarc-first with an active continental margin. The preservation of evidence for contemporary sedimentary and tectonic arc processes in the geologic record depends greatly on how well the various parts of the arc survive collision and orogeny in each case. Preservation of arc terranes likely is biased towards those that were in a state of tectonic accretion for tens of millions of years before collision, rather than tectonic erosion. The prevalence of tectonic erosion in modern intraoceanic arcs implies that valuable records of arc processes are commonly destroyed even before the arc collides with a continent. Arc systems are most likely to undergo tectonic accretion shortly before forward-facing collision with a continent, and thus most forearc and accretionary-prism material in ancient arc terranes likely is temporally biased toward the final stages of arc activity, when sediment flux to the trench was greatest and tectonic accretion prevailed. Collision geometry and tectonic erosion vs. accretion are important controls on the ultimate survival of material from the trench, forearc, arc massif, intra-arc basins, and backarc basins, and thus on how well an ancient arc terrane preserves evidence for tectonic processes such as subduction of aseismic ridges and seamounts, oblique plate convergence, and arc rifting. Forward-facing collision involves substantial recycling, melting, and fractionation of continent-derived material during and after collision, and so produces melts rich in silica and incompatible trace elements. As a result, forward-facing collision can drive the composition of accreted arc crust toward that of average continental crust.

Draut, Amy E.; Clift, Peter D.

2013-01-01

61

Molecular Modeling of Environmentally Important Processes: Reduction Potentials  

ERIC Educational Resources Information Center

|The increasing use of computational quantum chemistry in the modeling of environmentally important processes is described. The employment of computational quantum mechanics for the prediction of oxidation-reduction potential for solutes in an aqueous medium is discussed.|

Lewis, Anne; Bumpus, John A.; Truhlar, Donald G.; Cramer, Christopher J.

2004-01-01

62

Importance of online assessment in the e-learning process  

Microsoft Academic Search

In this article, we present some general aspects of the on-line assessment activity. For the purpose of this paper, we want to focus in the assessment activity that take place in the e-learning process and discuss the importance of this action for each participant of the process. After that, we outline the desirable characteristics of an assessment tool under an

Héctor Barbosa; Francisco Garcia

2005-01-01

63

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

64

Import, targeting, and processing of a plant polyphenol oxidase  

Microsoft Academic Search

A tomato (Lycopersicon esculentum 1.) gene encoding a precur- sor of polyphenol oxidase (PPO) was transcribed and translated in vitro. lhe import, targeting, and processing of the (35Slmethionine- labeled precursor protein (pPP0) were studied in isolated chloro- plasts. lhe protein was routed to the thylakoid lumen in two steps. lhe 67-kD precursor was first imported into the stroma in an

Amos Sommer; John C. Steffens; Alfred M. Mayer; Eitan Harel

1994-01-01

65

Import, targeting, and processing of a plant polyphenol oxidase.  

PubMed

A tomato (Lycopersicon esculentum L.) gene encoding a precursor of polyphenol oxidase (PPO) was transcribed and translated in vitro. The import, targeting, and processing of the [35S]methionine-labeled precursor protein (pPPO) were studied in isolated chloroplasts. The protein was routed to the thylakoid lumen in two steps. The 67-kD precursor was first imported into the stroma in an ATP-dependent step. It was processed to a 62-kD intermediate by a stromal peptidase. Translocation into the lumen was light dependent and involved processing of the 62-kD to the 59-kD mature form. The mature polypeptide was soluble in the lumen and not bound to thylakoids. This two-step targeting pattern was observed in plastids from a variety of plants including pea (Pisum sativum L.), tomato, and maize (Zea mays L.). The ratio between the intermediate and mature forms observed depended on the plant species, leaf age, growth conditions, and illumination regime to which the plants had been subjected. Cu2+ was not required for pPPO import or processing. Furthermore, low concentrations of Cu2+ (1-5 microM) markedly inhibited the first import step. Tentoxin specifically inhibited pPPO import, leaving the precursor bound to the envelope membrane. The two-step routing of pPPO into chloroplasts, typical of thylakoid lumen proteins, is consistent with the two-domain structure of the transit peptide and appears to be a feature of all plant PPO genes isolated so far. No evidence was found for unorthodox routing mechanisms, which have been suggested to be involved in the import of plant PPOs. The two-step routing may account for some of the multiplicity of PPO observed in vivo. PMID:7972497

Sommer, A; Ne'eman, E; Steffens, J C; Mayer, A M; Harel, E

1994-08-01

66

Import, targeting, and processing of a plant polyphenol oxidase.  

PubMed Central

A tomato (Lycopersicon esculentum L.) gene encoding a precursor of polyphenol oxidase (PPO) was transcribed and translated in vitro. The import, targeting, and processing of the [35S]methionine-labeled precursor protein (pPPO) were studied in isolated chloroplasts. The protein was routed to the thylakoid lumen in two steps. The 67-kD precursor was first imported into the stroma in an ATP-dependent step. It was processed to a 62-kD intermediate by a stromal peptidase. Translocation into the lumen was light dependent and involved processing of the 62-kD to the 59-kD mature form. The mature polypeptide was soluble in the lumen and not bound to thylakoids. This two-step targeting pattern was observed in plastids from a variety of plants including pea (Pisum sativum L.), tomato, and maize (Zea mays L.). The ratio between the intermediate and mature forms observed depended on the plant species, leaf age, growth conditions, and illumination regime to which the plants had been subjected. Cu2+ was not required for pPPO import or processing. Furthermore, low concentrations of Cu2+ (1-5 microM) markedly inhibited the first import step. Tentoxin specifically inhibited pPPO import, leaving the precursor bound to the envelope membrane. The two-step routing of pPPO into chloroplasts, typical of thylakoid lumen proteins, is consistent with the two-domain structure of the transit peptide and appears to be a feature of all plant PPO genes isolated so far. No evidence was found for unorthodox routing mechanisms, which have been suggested to be involved in the import of plant PPOs. The two-step routing may account for some of the multiplicity of PPO observed in vivo.

Sommer, A; Ne'eman, E; Steffens, J C; Mayer, A M; Harel, E

1994-01-01

67

Ganymede bright terrain at very high resolution - Geologic structure and regolith processes  

NASA Astrophysics Data System (ADS)

Bright terrain on Ganymede is characterized by sets ('sulci') of relatively high albedo parallel ridges and troughs hundreds of meters in vertical relief and 10s of km wide, commonly bounded on either side by large, deep throughgoing grooves. Based on Voyager data, the formation of bright terrain has been plausibly attributed to the emplacement of water ice volcanics, followed by tectonic extension. Recent data returned from the Galileo spacecraft have provided the basis for an updated interpretation of these results. In addition, the return by Galileo of very high (11 m/pxl) resolution images of a region of bright terrain has allowed the examination and analysis of features as small as boulders, yielding a very local perspective of bright terrain characteristics. Using these images, we have classified several geological units within this unnamed sulcus, and have analyzed the various degradation states of these units in terms of local-scale processes. In this way, a picture of local geological processes in Ganymede's bright terrain has begun to emerge.

Yingst, R. A.; Head, J. W.; Moore, J. M.; Chapman, C. R.; Pappalardo, R.; Galileo IMAGING Team

1997-03-01

68

Evolution of geological processes; International Geological Congress, Session, 28th, Washington, DC, July 9-19, 1989, Reports  

NASA Astrophysics Data System (ADS)

Topics discussed include the initial stages in the evolution of lithosphere, the tectonic evolution of the lithosphere in the Precambrian and the Phanerozoic, the evolution of sedimentation and lithogenesis in the Precambrian and the Phanerozoic, the evolution of the paleoenvironment of the ocean, and the evolution of ore formation. Papers are presented on the evolution of granite-greenstone terrains according to Sm-Nd geochronometry; volcanic belts as indicators of the tectonic evolution of the eastern continental margin of Eurasia; and the role of the earth tides in the tectonic evolution of the earth. Attention is also given to the evolution of Alpine-type molasses, the phenomena of irreversibility and recurrence in ore-formation in the course of the earth's geological history, the main features in the evolution of volcanogenic ferroaccumulation in the Early Precambrian, and the evolution of hydrocarbon and ore formation in the sedimentary strata of platform regions.

Ianshin, A. L.

69

Marine Geology: Research Beneath the Sea  

NSDL National Science Digital Library

Another informative offering from the US Geological Survey is the Marine Geology: Research Beneath the Sea Web site. Visitors can read about the agency's Marine Geology program which "strives to increase our understanding of the geology of the lands covered by water." Topics include methods and equipment used for the research, plate tectonics, resources in the marine realm, predicting effects of marine processes, new frontiers, and even images of marine geology. This interesting and unique site does a good job of explaining and educating the public on this important segment of the agency's research.

70

The Importance of Biophysicochemical Transport Processes in Hyporheic Exchange  

NASA Astrophysics Data System (ADS)

Hyporheic exchange processes are generally analyzed in terms of hydrologic stream-subsurface interactions, biogeochemical reactions in the hyporheic zone, or nutrient and carbon uptake in the context of stream metabolism. Often, investigations are motivated primarily by applications in hydrology, contaminant transport, or stream ecology, and thus focus on only one of these aspects of hyporheic exchange. However, it is important to consider the interrelationships between biological, physical, and chemical processes, which are inevitably and inextricably linked because the hyporheic zone represents an extraordinary complex environmental system. The nature of biophysicochemical linkages in the hyporheic zone will be discussed in general terms and illustrated with two important examples. The transport of microorganisms such as the pathogen Cryptosporidium parvum in streams is dependent on both physical transport processes and physicochemical interactions in the hyporheic zone. The transport of labile particulate organic matter to the hyporheic zone is dependent on similar processes, but also induces biologically-mediated alteration of the subsurface environment. In these types of studies, insufficient characterization of either physical, chemical, or biological processes can lead to errors in interpretation of overall system behavior.

Packman, A. I.

2001-12-01

71

Practical petroleum geology  

SciTech Connect

This book presents the scope and content of the field of petroleum geology from the standpoint of the practicing petroleum geologist. Includes chapters on basic geological concepts, the sedimentation process, accumulation of hydrocarbons, exploration, economic examination, drilling of exploratory wells, recovering oil and gas (reservoir geology), and the relationship of geology to the petroleum industry as a whole.

Not Available

1985-01-01

72

A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes  

SciTech Connect

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

Birkholzer, Jens T.

2004-12-06

73

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

SciTech Connect

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

J.T. Birkholzer

2005-01-21

74

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

75

Guiding the Service Engineering Process: The Importance of Service Aspects  

NASA Astrophysics Data System (ADS)

Service-oriented System engineering (SOSE) and traditional software engineering mainly differ for their focus and aims. These differences are reflected by a number of aspects peculiar to SOSE (service aspects). In this paper we specifically discuss three service aspects: the relevance of cross-organizational collaboration, increased importance of the identification of stakeholders, and the need for increased effort at run-/change time. We argue that SOSE methodologies provide better guidance on their application when service aspects are emphasized in associated process models. By highlighting the three service aspects in a process model of the methodology defined in a large European project, we show specifically how each aspect provides guidance for engineering service-oriented systems in practice.

Gu, Qing; Lago, Patricia; di Nitto, Elisabetta

76

Importance of measurement accuracy in statistical process control  

NASA Astrophysics Data System (ADS)

Precision is deemed the most important aspect of a measurement for process control. This paper discusses the role of accuracy in process control and product quality. Although the discussion is emphasized for CD SEM metrology systems, the idea can be extended to other metrology areas such as thickness measurement where in addition to thickness, material characteristics also play a role. In 1999, the characteristics of accuracy were published in a landmark paper. The authors introduced the concept of characteristic slope and offset for the purpose of tool evaluation. Slope and offset were obtained from correlation plots of a measurement tool under test with a reference measurement system. The measurands were features that represent the range of process variations in a line. This paper builds on the ideas put forth in that reference and discusses the impact of measurement accuracy on process control. First, the issue is considered in an abstract sense, by comparison of the measurement method under test to a standard reference method. Then practical implications are discussed in more detail when tools from different suppliers are used in a fab to manufacture products.

Askary, Farid; Sullivan, Neal T.

2000-06-01

77

Schoolyard Geology  

NSDL National Science Digital Library

This set of lessons provides teachers with ideas on how to turn their schoolyards into a rich geologic experience that students will find familiar, easily accessible, and personally relevant. The three lesson plans feature materials on mapping, rock descriptions and geologic interpretations, ages of rocks, and dinosaur tracks. Lesson 1, "Map Your Schoolyard," teaches students what maps are, what they are used for, and some features used on maps (north arrow, scale bar, legend, etc.). Lesson 2, "Rock Stories," illustrates how to make geologic observations and what important properties of rocks to look for. Lesson 3, "GeoSleuth Schoolyard," teaches students that geology is a lot like detective work, in which geologists infer the sequence and timing of events by collecting evidence and making observations. Relevant California state science standards are also listed.

78

Processing map and well log data for geological and soil surveys  

SciTech Connect

Design of a system which accepts geological maps or soil maps, together with corresponding well logs and produces interpretation maps, is described. The major aim was to get a processing program that would be useful at an operational scale that avoids the use of special purpose graphics hardware. This was achieved by using segment encoding of lines and by treatment of mapped units as basic graphical units (atoms). The system operation was split into an input phase and a processed phase. Input- and file-building require some technical experience, but are a one-time affair, whereas subsequent processing requires less (graphical) resources and experience, but is of a repetitive nature. When writing processing programs, emphasis was placed on ease of adding options. Clever improvements of efficiency (e.g., disk traffic) were not deemed worthwhile or even wise. Two driving forces behind the project required the programs reported here. First was the observation that digital data can be used only if appropriate programs are readily available to produce required results without need for large investments in hardware. Second was the idea that digital tools could be most effective if they allow the end-user (customer) to interact directly with the full base of data without recourse to technical experts. The resulting system is operational and running on a VAX 11/750, coded in FORTRAN.

van Kuilenburg, J.

1986-01-01

79

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

80

Importance of Automation and Process Control for German Coal Preparation.  

National Technical Information Service (NTIS)

Comprehensive automation in coal preparation with the goal of process optimization presupposes an efficient mathematical model and a reliable central process control in on-line operation. The central process control, using a process computer, is based on ...

D. Bartelt W. Roesner

1977-01-01

81

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

82

Report of the second meeting of the consultants on coupled processes associated with geological disposal of nuclear waste  

SciTech Connect

The second meeting of the Consultants on Coupled Processes Associated with Geological Disposal of Nuclear Waste occurred on January 15-16, 1985 at Lawrence Berkeley Laboratory (LBL). All the consultants were present except Dr. K. Kovari, who presented comments in writing afterward. This report contains a brief summary of the presentations and discussions from the meeting. The main points of the speakers' topics are briefly summarized in the report. Some points that emerged during the discussions of the presentations are included in the text related to the respective talks. These comments are grouped under the headings: Comments on Coupled Processes in Unsaturated Fractured Porous Media, Comments on Overview of Coupled Processes, Presentations by Consultants on Selected Topics of Current Interest in Coupled Processes, and Recommendations for Underground Field Tests with Applications to Three Geologic Environments.

Tsang, Chin-Fu; Mangold, D.C.

1985-09-01

83

The importance of dreams and action in the adolescent process.  

PubMed

The author argues that after puberty dreams and action are indicators of the capacity of the psychic apparatus to perform the work of binding drive energy. He notes that the development of adult sexuality always involves risk and that effective dream activity affords a definitive solution to the problem of incestuous and parricidal temptations, which attain an unprecedented pitch of intensity with the onset of sexual and procreative potency in adolescence. The author illustrates his thesis by the case of an adolescent patient with particular sexual pathology who broke down at the age of 17 and who, once he became able to dream in the course of analysis, had less need to act out. A 'work of the negative' is presented as a paradoxical but important element in psychic development. Dreaming and action are stated to be inseparable and to constitute an essential safety valve that facilitates the developmental process. A discussion of the connections between dreams and initiation leads to some ethnological considerations on sexuality and society, and the paper ends with a plea not to overlook the death drive. PMID:8789165

Ladame, F

1995-12-01

84

Geologic mapping of tectonic planets  

Microsoft Academic Search

Geological analysis of planets typically begins with the construction of a geologic map of the planets’ surfaces using remote data sets. Geologic maps provide the basis for interpretations of geologic histories, which in turn provide critical relations for understanding the range of processes that contributed to the evolution. Because geologic mapping should ultimately lead to the discovery of the types

Vicki L. Hansen

2000-01-01

85

The encyclopedia of applied geology  

Microsoft Academic Search

This compendium of engineering geology data includes contributions by experts from many countries. Topics center around the field of engineering geology, with special focus on landscapes, earth materials, and the ''management'' of geological processes. How to use geology to serve man is given particular attention. More than 80 entries deal with hydrology, rock structure monitoring, soil mechanics, and engineering geology.

Finkl

1984-01-01

86

Computational and Spectroscopic Investigations of the Molecular Scale Structure and Dynamics of Geologically Important Fluids and Mineral-Fluid Interfaces  

SciTech Connect

Research supported by this grant focuses on molecular scale understanding of central issues related to the structure and dynamics of geochemically important fluids, fluid-mineral interfaces, and confined fluids using computational modeling and experimental methods. Molecular scale knowledge about fluid structure and dynamics, how these are affected by mineral surfaces and molecular-scale (nano-) confinement, and how water molecules and dissolved species interact with surfaces is essential to understanding the fundamental chemistry of a wide range of low-temperature geochemical processes, including sorption and geochemical transport. Our principal efforts are devoted to continued development of relevant computational approaches, application of these approaches to important geochemical questions, relevant NMR and other experimental studies, and application of computational modeling methods to understanding the experimental results. The combination of computational modeling and experimental approaches is proving highly effective in addressing otherwise intractable problems. In 2006-2007 we have significantly advanced in new, highly promising research directions along with completion of on-going projects and final publication of work completed in previous years. New computational directions are focusing on modeling proton exchange reactions in aqueous solutions using ab initio molecular dynamics (AIMD), metadynamics (MTD), and empirical valence bond (EVB) approaches. Proton exchange is critical to understanding the structure, dynamics, and reactivity at mineral-water interfaces and for oxy-ions in solution, but has traditionally been difficult to model with molecular dynamics (MD). Our ultimate objective is to develop this capability, because MD is much less computationally demanding than quantum-chemical approaches. We have also extended our previous MD simulations of metal binding to natural organic matter (NOM) to a much longer time scale (up to 10 ns) for significantly larger systems. These calculations have allowed us, for the first time, to study the effects of metal cations with different charges and charge density on the NOM aggregation in aqueous solutions. Other computational work has looked at the longer-time-scale dynamical behavior of aqueous species at mineral-water interfaces investigated simultaneously by NMR spectroscopy. Our experimental NMR studies have focused on understanding the structure and dynamics of water and dissolved species at mineral-water interfaces and in two-dimensional nano-confinement within clay interlayers. Combined NMR and MD study of H2O, Na+, and Cl- interactions with the surface of quartz has direct implications regarding interpretation of sum frequency vibrational spectroscopic experiments for this phase and will be an important reference for future studies. We also used NMR to examine the behavior of K+ and H2O in the interlayer and at the surfaces of the clay minerals hectorite and illite-rich illite-smectite. This the first time K+ dynamics has been characterized spectroscopically in geochemical systems. Preliminary experiments were also performed to evaluate the potential of 75As NMR as a probe of arsenic geochemical behavior. The 75As NMR study used advanced signal enhancement methods, introduced a new data acquisition approach to minimize the time investment in ultra-wide-line NMR experiments, and provides the first evidence of a strong relationship between the chemical shift and structural parameters for this experimentally challenging nucleus. We have also initiated a series of inelastic and quasi-elastic neutron scattering measurements of water dynamics in the interlayers of clays and layered double hydroxides. The objective of these experiments is to probe the correlations of water molecular motions in confined spaces over the scale of times and distances most directly comparable to our MD simulations and on a time scale different than that probed by NMR. This work is being done in collaboration with Drs. C.-K. Loong, N. de Souza, and A.I. Kolesnikov at the Intense Pulsed

R. James Kirkpatrick; Andrey G. Kalinichev

2008-11-25

87

Physical geology  

Microsoft Academic Search

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

B. Skinner; S. Porter

1987-01-01

88

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.

89

27 CFR 41.1 - Importation of tobacco products, cigarette papers and tubes, and processed tobacco.  

Code of Federal Regulations, 2013 CFR

...Importation of tobacco products, cigarette papers and tubes, and processed tobacco. ...IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Scope...Importation of tobacco products, cigarette papers and tubes, and processed tobacco....

2013-04-01

90

POLYMER ENGINEERING: The importance of heat transfer in polymer processing  

Microsoft Academic Search

Heat transfer plays a critical role in the processing of thermoplastic polymers, influencing capital costs, operating costs, production rates and product quality. Closer collaboration between scientists and engineers in this field would improve the efficiency of polymer processing operations

M. F. Edwards; D. I. Ellis

1982-01-01

91

Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Processing, Taxonomy, and Quality Control of Benthic Macroinvertebrate Samples.  

National Technical Information Service (NTIS)

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 v...

I. S. Moulton J. L. Carter S. A. Grotheer T. F. Cuffney T. M. Short

2000-01-01

92

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

93

Increased importance of the documented development stage in process validation?  

PubMed Central

Current trends in pharmaceutical quality assurance moved when the Federal Drug Administration (FDA) of the USA published its new guideline on process validation in 2011. This guidance introduced the lifecycle approach of process validation. In this short communication some typical changes from the point of view of practice of API production are addressed in the light of inspection experiences. Some details are compared with the European regulations.

Mohammed-Ziegler, Ildiko; Medgyesi, Ildiko

2011-01-01

94

User's manual for the National Water Information System of the U.S. Geological Survey: Automated Data Processing System (ADAPS)  

USGS Publications Warehouse

The Automated Data Processing System (ADAPS) was developed for the processing, storage, and retrieval of water data, and is part of the National Water Information System (NWIS) developed by the U.S. Geological Survey. NWIS is a distributed water database in which data can be processed over a network of computers at U.S. Geological Survey offices throughout the United States. NWIS comprises four subsystems: ADAPS, the Ground-Water Site Inventory System (GWSI), the Water-Quality System (QWDATA), and the Site-Specific Water-Use Data System (SWUDS). This section of the NWIS User's Manual describes the automated data processing of continuously recorded water data, which primarily are surface-water data; however, the system also allows for the processing of water-quality and ground-water data. This manual describes various components and features of the ADAPS, and provides an overview of the data processing system and a description of the system framework. The components and features included are: (1) data collection and processing, (2) ADAPS menus and programs, (3) command line functions, (4) steps for processing station records, (5) postprocessor programs control files, (6) the standard format for transferring and entering unit and daily values, and (7) relational database (RDB) formats.

Geological Survey (U.S.)

2003-01-01

95

Influence in the Policy Making Process: the Rise of Economics at the Expense of Geology  

Microsoft Academic Search

Scientific influence in resource policy making reached a zenith in the early 1970s during the legislative monopoly in the United States Congress that produced command and control regulatory protection policies. This congressional consensus began in 1879 with legislation producing the U.S. Geological Survey. Other scientific agencies followed. The Congresses of the first half of the 20th century merely strengthened the

K. M. McCurdy

2007-01-01

96

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

97

Collection & Processing of Medically Important Arthropods for Arbovirus Isolation.  

ERIC Educational Resources Information Center

|The methods given for collecting, preserving, and processing mosquitoes and other archropods for isolation of arboviruses are those used by the National Communicable Disease Center. Techniques of collecting mosquitoes as they bite, using light or bait traps, and from their daytime resting sites are described and illustrated. Details of subsequent…

Sudia, W. Daniel; Chamberlain, Roy W.

98

Geologic nozzles  

Microsoft Academic Search

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m\\/s. Critical velocities in large rivers can be of the order of 1-10 m\\/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance

Susan Werner Kieffer

1989-01-01

99

Influence in the Policy Making Process: the Rise of Economics at the Expense of Geology  

NASA Astrophysics Data System (ADS)

Scientific influence in resource policy making reached a zenith in the early 1970s during the legislative monopoly in the United States Congress that produced command and control regulatory protection policies. This congressional consensus began in 1879 with legislation producing the U.S. Geological Survey. Other scientific agencies followed. The Congresses of the first half of the 20th century merely strengthened the influence of science in policy outcomes that was present in the earliest congressional debates. What then happened at the turn of the 21st century when representatives in the administration frequently dismissed sound science in their policy deliberations? Policy monopolies arise from agreement in principle, and alternately decline as rival ideas gain hold in policy space. The science policy monopoly began to face competition from economics when cost benefit analysis was introduced into political parlance in 1936, again in the 1950s as a successful blocking tactic by the minority in opposition to western dams, and in 1961 when systems analysis was introduced to the Department of Defense under Robert McNamara. As businessmen replaced farmers as the modal profession of legislators, the language of politics increasingly contained economic terms and concepts. A ternary diagram and a budget simplex have the same shape, but have different theoretical meanings and imply different processes. Policy consensus is not dissimilar to a mineral phase diagram, with boundary conditions marked by election magnitudes and majority parties. The 1980 elections brought economic principles into all aspects of government decision-making, with a particular long-term interest in reducing the size and scope of government. Since then the shift in policy jargon from science to economics has been incremental. With the 1994 Republican legislative majority, scientists, their programs, and the funds required to maintain data collection projects became targets. The Conservative Consensus resulting from the 2000 elections has disregarded and even ridiculed scientific experts, their analyses, and their data. The first step in rebuilding an effective policy consensus based on sound science is recognizing the phase transition that privileges conservative policy solutions which minimize science and elevate economic principles.

McCurdy, K. M.

2007-12-01

100

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

NASA Astrophysics Data System (ADS)

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

Nitkina, Elena

2013-04-01

101

Gaseous prebreakdown processes that are important for pulsed power switching  

SciTech Connect

This paper is the latest in a series of papers that attempt to relate the multiple observed gas breakdown phenomena to useful switch design parameters. This series started when the as density, not the gas type, was observed to give a power law relationship for the breakdown delay time delays of several gases to the applied electric field. This paper will show that this triggering or breakdown initiating process is similar to, if not the same as, a corona discharge. A hypothesis is made and a simple voltage breakdown relationship is shown to exist for air gaps between 1 and 1000 cm for sharp electrodes to a plane. 9 refs., 12 figs.

Martin, T.H.; Seamen, J.F. (Sandia National Labs., Albuquerque, NM (USA)); Jobe, D.O.; Pena, G.E. (Ktech Corp., Albuquerque, NM (USA))

1991-01-01

102

Groundwater as a geologic agent: An overview of the causes, processes, and manifestations  

Microsoft Academic Search

The objective of the present paper is to show that groundwater is a general geologic agent. This perception could not, and\\u000a did not, evolve until the system nature of basinal groundwater flow and its properties, geometries, and controlling factors\\u000a became recognized and understood through the 1960s and 1970s.\\u000a \\u000a The two fundamental causes for groundwater's active role in nature are its

József Tóth

1999-01-01

103

Dangerous geological processes in the Baikal rift zone and adjacent territories  

Microsoft Academic Search

In the context of active endogenic, exogenic, and technogenic factors, the dynamics of developing geological hazards and risks\\u000a is estimated for the linear transport systems that run across the strong earthquake epicentral areas of the Baikal rift zone\\u000a and adjacent territories. The presence of ancient and new seismic structures in the modern relief can be regarded as an indicator\\u000a of

V. K. Laperdin; V. S. Imaev

2011-01-01

104

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

NASA Astrophysics Data System (ADS)

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

Walsh, E. O.; Davis, E.

2008-12-01

105

Millikan Lecture 1994: Understanding and teaching important scientific thought processes  

NSDL National Science Digital Library

Physics is an intellectually demanding discipline and many students have difficulties learning to deal with it. Further, our instruction is often far less effective than we realize. Indeed, recent investigations have revealed that many students, even when getting good grades, emerge from their basic physics courses with signification scientific misconcepts, with prescientific notions, with poor problem-solving skills, and with an inability to apply what they ostensibly learned. In short, students' acquired physics knowledge is often largely nominal rather than functiional. This situation leads one to ask: Why is this so, and what can be done about it? More specifically, it has led me to address the following two basic questions: (a) Can one understand better the underlying throught processes required to deal with a science like physics? (b) How can such an understanding be used to design more effective instruction? These are the questions which have been the focus of my work during the last several years and which I want to discuss in this article.

Reif, Frederick

2011-07-28

106

Slope processes in weathred volcaniclastic rocks of the Camaldoli hill (Naples, Italy): geological, structural and volcanological aspects  

NASA Astrophysics Data System (ADS)

The Camaldoli hill is the remnant of the north-eastern margin of the Campi Flegrei caldera (CFc), generated by two main collapses related to the Campanian Ignimbrite (CI; 39 ka) and Neapolitan Yellow Tuff (NYT; 15 ka) eruptions. We have reconstructed its geological, lithological and structural features, and their effects on slope instability. The backbone of the hill includes the remnants of two partially superposed tuff cones, lying between CI and NYT. All these rocks are mantled by a sequence of loose pyroclastic, anthropic and epiclastic deposits, with abrupt thickness and facies variations. Only the uppermost 50-100 cm have been reworked by exogenous agents and anthropic and biological activity. The hill is affected by three fault systems. Its structural setting is mainly due to reactivation of the CI caldera faults until 9.5 ka. Deformation younger than 15 ka is testified by landslide deposits, due to slope instability induced by volcanotectonism, and by a high-angle erosional unconformity, which likely is the response to a base level lowering, generated by faults activation. A detailed stratigraphic analysis of the reworked deposits at the foot of the slopes allowed us to define both depositional mechanisms and sedimentation rate. The results of combined volcanological, and geomorphological and engineering-geological (Calcaterra et al., this session) studies, allowed to constrain and quantify past geological processes and to hypothesise the future evolution of the hill's slopes.

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

2003-04-01

107

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.

108

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

109

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

110

Comparison Between Stress and Strain Quantities of the Failure-Deformation Process of Fennoscandian Hard Rocks Using Geological Information  

NASA Astrophysics Data System (ADS)

The aim of this paper was to compare the stress and strain quantities that are related to the failure-deformation process of hard rock. The data used here was obtained from laboratory uniaxial compression tests performed on different types of Fennoscandian hard rocks. The failure-deformation process quantities were compared at each deformation stage and for each single specimen. Moreover, geological information such as the rock origin process and the rock characteristics of the specimens were studied and linked to the stress and strain quantities. The purpose was to investigate the influence of the rock origin process and rock characteristics on these quantities. The main results of this study showed that the normalized crack damage lateral strain ( ? 3cd/ ? 3 p ) and the volumetric strain ( ? crv-ci and ? v-cd) quantities were strongly affected by the grain size. The normalized and volumetric quantities are weakly dependent on the mineral composition.

Pérez Hidalgo, Kelvis; Nordlund, Erling

2013-01-01

111

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

112

Quaternary geology and sedimentary processes in the vicinity of Six Mile Reef, eastern Long Island Sound  

USGS Publications Warehouse

Six Mile Reef, a sandy, 22-m-high shoal trending east-west and located about 7.8 km off the Connecticut coast, has a core of postglacial marine deltaic deposits mantled by tidally reworked modern sediments. Sedimentary environments off the eastern end of the shoal are characterized by processes associated with long-term erosion or nondeposition, a mobile-sediment-limited seafloor armored by gravelly sand, and scattered elongate fields of barchanoid sand waves. The barchanoid waves reach amplitudes of 20 m, are concave westward, and occur in individual and coalesced forms that become progressively more complex westward. The seafloor on and adjacent to the shoal is characterized by processes associated with coarse bedload transport and covered primarily with asymmetrical transverse sand waves. The transverse waves exceed 8 m in amplitude, have slip faces predominantly oriented to the west and southwest, and have straight, slightly sinuous, and curved crests. Megaripples, which mimic the asymmetry of the sand waves, are commonly present on stoss slopes and in troughs; current ripples are ubiquitous. The amplitude and abundance of large bedforms decrease markedly westward of Six Mile Reef. The seabed there is covered with small, degraded ripples, reflecting lower-energy environments and processes associated with sorting and reworking of seafloor sediments. Megaripples and current ripples on the sand waves suggest that transport is active and that the bedforms are propagating under the present hydraulic regime. Net bedload sediment transport is primarily to the west, as evidenced by textural trends of surficial sediments, orientation of the barchanoid waves, and asymmetry of the transverse waves and of the scour marks around bedrock outcrops, boulders, and shipwrecks. One exception occurs at the western tip of the shoal, where sand-wave morphology indicates long-term eastward transport, suggesting that countercurrents in this area shape the shoal and are important to its maintenance.

Poppe, L. J.; Williams, S. J.; Moser, M. S.; Forfinski, N. A.; Stewart, H. F.; Doran, E. F.

2008-01-01

113

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

114

Martian Cratering 10. Progress in use of crater counts to interpret geological processes: Examples from two debris aprons  

NASA Astrophysics Data System (ADS)

Recent controversies about systems of crater-count dating have been largely resolved, and with continuing refinements, crater counts will offer a fundamental geological tool to interpret not only ages, but also the nature of geological processes altering the surface of Mars. As an example of the latter technique, we present data on two debris aprons east of Hellas. The aprons show much shorter survival times of small craters than do the nearby contiguous plains. The order-of-magnitude depths of layers involved in the loss process can be judged from the depths of the affected craters. We infer that ice-rich layers in the top tens of meters of both aprons have lost crater topography within the last few 10 8 yr, probably due to flow or sublimation of ice-rich materials. Mantling by ice-rich deposits, associated with climate change cycles of obliquity change, has probably also affected both the aprons and the plains. The crater-count tool thus adds chronological and vertical dimensional information to purely morphological studies.

Hartmann, William K.; Werner, Stephanie C.

2010-06-01

115

Vesta: A Geological Overview  

NASA Astrophysics Data System (ADS)

Observations from the Dawn spacecraft [1] enable the derivation of the asteroid 4Vesta's shape, facilitate mapping of the surface geology, and provide the first evidence for interpreting Vesta's geological evolution. Science data were acquired during the approach to Vesta, a circular polar (Survey) orbit at an altitude of 2700 km providing ~ 230 m/pix camera scale, and during a circular high-altitude mapping orbit (HAMO) at 700 km altitude with a camera scale of ~ 65 m/pixel. Currently Dawn is orbiting Vesta in a low-altitude mapping orbit (LAMO) at 210 km altitude, yielding a global image coverage of ~20 m/pixel at the time of EGU [2,3,4,5]. Geomorphology and distribution of surface features provide evidence for impact cratering, tectonic activity, and regolith and probable volcanic processes. Craters with dark rays, bright rays, and dark rim streaks have been observed, suggesting buried stratigraphy. The largest fresh craters retain a simple bowl-shaped morphology, with depth/diameter ratios roughly comparable to lunar values. The largest crater Rheasilvia, an ~500 km diameter depression at the south pole, includes an incomplete inward facing cuspate scarp and a large central mound surrounded by unusual complex arcuate ridge and groove patterns, and overlies an older ~400 km wide basin. A set of large equatorial troughs is related to these south polar structures. Vesta exhibits rugged topography ranging from -22 km to +19 km relative to a best fit ellipsoidal shape. Vesta's topography has a much greater range in elevation relative to its radius (15%) than do the Moon and Mars (1%) or the Earth (0.3%), but less than highly battered smaller asteroids like Lutetia (40%). This also identifies Vesta as a transitional body between asteroids and planets. The surface of Vesta exhibits very steep topographic slopes that are near the angle of repose. Impacts onto these steep surfaces, followed by slope failure, make resurfacing - due to impacts and their associated gravitational forces and seismic activity - an important geologic process on Vesta that significantly alters the morphology of geologic features and adds to the complexity of its geologic history. In general, Vesta's geology is more like the Moon and rocky planets than other asteroids.

Jaumann, R.

2012-04-01

116

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

Microsoft Academic Search

In order to assess the capabilities of GPR in planetary geologic studies, we measure and characterize GPR signatures of geologic environments that may be encountered on the Moon and compare them with ground-truth observations of subsurface exposures.

P. S. Russell; J. A. Grant; K. K. Williams; L. M. Carter; W. B. Garry; D. B. J. Bussey

2011-01-01

117

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

118

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

119

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

SciTech Connect

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

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

1997-11-26

120

Geology of the Colorado Plateau  

NSDL National Science Digital Library

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

Institute, Colorado P.

121

Geological Evolution of Lada Terra, Venus  

NASA Astrophysics Data System (ADS)

This paper presents geologic history of Lada Terra of Venus. Geological mapping revealed formation of large-scale extensional belts, coronae, and volcanogenic plains. The sequence of geologic events provides clues to deeper geodynamic processes.

Kumar, P. S.; Head, J. W.

2011-03-01

122

Archeological Geology  

ERIC Educational Resources Information Center

|Describes the rapid expansion of archeological geology, especially in the area of archeological excavations, where geologists use dating techniques and knowledge of geological events to interpret archeological sites. (MLH)|

Rapp, George

1977-01-01

123

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

124

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

125

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

126

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

127

Effect of modeling factors on the dissolution-diffusion-convection process during CO2 geological storage in deep saline formations  

NASA Astrophysics Data System (ADS)

It is well known that during CO2 geological storage, density-driven convective activity can significantly accelerate the dissolution of injected CO2 into water. This action could limit the escape of supercritical CO2 from the storage formation through vertical pathways such as fractures, faults and abandoned wells, consequently increasing permanence and security of storage. First, we investigated the effect of numerical perturbation caused by time and grid resolution and the convergence criteria on the dissolution-diffusion-convection (DDC) process. Then, using the model with appropriate spatial and temporal resolution, some uncertainty parameters investigated in our previous paper such as initial gas saturation and model boundaries, and other factors such as relative liquid permeability and porosity modification were used to examine their effects on the DDC process. Finally, we compared the effect of 2D and 3D models on the simulation of the DDC process. The above modeling results should contribute to clear understanding and accurate simulation of the DDC process, especially the onset of convective activity, and the CO2 dissolution rate during the convection-dominated stage.

Zhang, Wei

2013-06-01

128

WIPP site and vicinity geological field trip  

SciTech Connect

The Environmental Evaluation Group (EEG) is conducting an assessment of the radiological health risks to people from the Waste Isolation Pilot Plant (WIPP). As a part of this work, EEG is making an effort to improve the understanding of those geological issues concerning the WIPP site which may affect the radiological consequences of the proposed repository. One of the important geological issues to be resolved is the timing and the nature of the dissolution processes which may have affected the WIPP site. EEG organized a two-day conference of geological scientists, titled Geotechnical Considerations for Radiological Hazard Assessment of WIPP on January 17-18, 1980. During this conference, it was realized that a field trip to the site would further clarify the different views on the geological processes active at the site. The field trip of June 16-18, 1980 was organized for this purpose. This report provides a summary of the field trip activities along with the participants post field trip comments. Important field stops are briefly described, followed by a more detailed discussion of critical geological issues. The report concludes with EEG's summary and recommendations to the US Department of Energy for further information needed to more adequately resolve concerns for the geologic and hydrologic integrity of the site.

Chaturvedi, L.

1980-10-01

129

Geologic Map of North America  

USGS Multimedia Gallery

The Geologic Map of North America is a product of GSA's Decade of North American Geology (DNAG) project. At a scale of 1:5,000,000, this map covers ~15% of Earth's surface and differs from previous maps in several important respects: it is the first such map to depict the geology of the seafloor, th...

2010-06-25

130

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

131

Processes of lunar crater degradation: Changes in style with geologic time  

Microsoft Academic Search

Lunar crater degradation can be divided into two time periods based on differing styles and rates of crater degradation processes.\\u000a Comparison of lunar radiometric age scales and the relative degradation of crater morphologic features for craters larger\\u000a than about 5 km diam shows that Period I, prior to about 3.85–3.95 b.y. ago, is characterized by a high influx rate and

James W. Head

1975-01-01

132

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

Microsoft Academic Search

Digital, single-channel, high-resolution seismic reflection profiles were acquired from the insular continental shelf of North Carolina, USA along a data grid extending from Oregon Inlet northward 48 km to Duck, North Carolina and from the nearshore zone seaward approximately 28 km (total surveyed area=1334 km2). These data were processed and interpreted to delineate principal reflecting horizons and develop a three-dimensional

Stephen K. Boss; Charles W. Hoffman; Brett Cooper

2002-01-01

133

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

Microsoft Academic Search

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,

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

2003-01-01

134

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

135

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

136

Lunar geology  

NASA Astrophysics Data System (ADS)

The development of a lunar geological map is traced, from the post-war period through the final Apollo mission. The impact of geological discoveries on earth on lunar geology is explained, and the use of photographs of the lunar surface to deduce its stratigraphy is described. The confirmation of the ages of various parts of the moon's surface through analysis of moon rocks is also discussed.

Shoemaker, E.

137

Development of geological processes on the Earth and their impact on the early biosphere  

NASA Astrophysics Data System (ADS)

Though life has been already existed in the Paleoarchean, biosphere started rapid development only in Paleoproterozoic from about 2.4-2.3 Ga. It was practically coincided with period of irreversible change of tectonomagmatic activity on the Earth, when high-Mg magmatism of the early Precambrian, derived from depleted mantle, gave place to the geochemical-enriched Fe-Ti basalts [12]. New type of magmas was characterized by elevated and high contents of elements which are required for metabolism and fermentation. It suggests that this event acted as a trigger for environmental changes and rapid evolution of biosphere, supplying a qualitatively new biophilic material to the Earth's surface. Venus and Mars developed at the same scenario; very likely, that at the beginning liquid water occurred on them; however, processes of the planetary development were favorable for the biosphere evolution only on the Earth.

Sharkov, E.

2012-09-01

138

Research on the Photon Absorption Processes of Gases Important in the Upper Atmosphere.  

National Technical Information Service (NTIS)

The results of investigations into the absorption processes of gases important in upper atmosphere chemistry and physics are presented. The principle region studied in the vacuum ultraviolet at wavelengths less than 3000 A. Methods of producing the OH rad...

J. L. Roebber

1970-01-01

139

California Geological Survey: Geologic Maps  

NSDL National Science Digital Library

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

140

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.

141

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

SciTech Connect

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

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

2008-07-01

142

How Important is Vehicle Safety in the New Vehicle Purchase\\/Lease Process for Fleet Vehicles?  

Microsoft Academic Search

Objective. Despite the potential benefits that fleet vehicle purchase decisions could have on road safety, the role that vehicle safety plays in fleet managers' purchase decisions is poorly understood.Methods. In this study, fleet managers from Sweden and Spain completed a questionnaire regarding the importance of vehicle safety in the new vehicle purchase\\/lease process and the importance that is placed on

Sjaanie Koppel; Judith Charlton; Brian Fildes

2007-01-01

143

How important is vehicle safety in the new vehicle purchase process?  

Microsoft Academic Search

Whilst there has been a significant increase in the amount of consumer interest in the safety performance of privately owned vehicles, the role that it plays in consumers’ purchase decisions is poorly understood. The aims of the current study were to determine: how important vehicle safety is in the new vehicle purchase process; what importance consumers place on safety options\\/features

Sjaanie Koppel; Judith Charlton; Brian Fildes; Michael Fitzharris

2008-01-01

144

Redesigning and Transforming: A Case Study of the Role of Semiotic Import in Early Composing Processes  

ERIC Educational Resources Information Center

|In this article, I explore the role of semiotic import (Van Leeuwen, 2005) in the composing processes of three bilingual students (six to seven years old) emerging as writers of English. Using social semiotic (Van Leeuwen, 2005) and design (New London Group, 2000) frameworks, I trace a qualitative "micro-history" of how the students imported

Ranker, Jason

2009-01-01

145

Redesigning and Transforming: A Case Study of the Role of Semiotic Import in Early Composing Processes  

ERIC Educational Resources Information Center

In this article, I explore the role of semiotic import (Van Leeuwen, 2005) in the composing processes of three bilingual students (six to seven years old) emerging as writers of English. Using social semiotic (Van Leeuwen, 2005) and design (New London Group, 2000) frameworks, I trace a qualitative "micro-history" of how the students imported

Ranker, Jason

2009-01-01

146

77 FR 38033 - Notice of Establishment of a Commodity Import Approval Process Web Site  

Federal Register 2010, 2011, 2012, 2013

...Establishment of a Commodity Import Approval Process Web Site AGENCY: Animal and Plant Health Inspection...of a new Plant Protection and Quarantine Web site that will provide stakeholders with...comment on draft risk assessments. This Web site will make the commodity import...

2012-06-26

147

Yellowstone Geology  

NSDL National Science Digital Library

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

Park, Yellowstone N.

148

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

149

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

150

The Relative Importance of Warm Rain and Melting Processes in Freezing Precipitation Events  

Microsoft Academic Search

The importance of warm rain and melting processes in freezing precipitation events is investigated by analyzing 972 rawinsonde soundings taken during freezing precipitation. The soundings cover regions of the United States east of the Rocky Mountain states for the period 1970-94. The warm rain process was found to be unambiguously responsible for freezing precipitation in 47% of the soundings. In

Robert M. Rauber; Larry S. Olthoff; Mohan K. Ramamurthy; Kenneth E. Kunkel

2000-01-01

151

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

152

Geologic Maps and Geologic Structures: A Texas Example  

NSDL National Science Digital Library

This Historical Geology lab exercise is an accompaniment to lab class instruction about geologic structures (folding and faulting) and geologic maps. It also serves as an excellent introduction to the Geology of the state of Texas. "Coloring" geologic maps, an important part of the exercise, may seem like a very elementary learning technique. But this lab engages students actively, and since the subject is often already somewhat familiar to them, emphasizing both the geology and geography of Texas, students receive it enthusiastically. This activity could be adapted to other regions, since most states have color 8 1/2 by 11 geologic maps available. A color map could be scanned and modified in Photoshop to create a simplified black and white version as was done in the assignment handout.

Steinberg, Roger

153

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

154

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

Microsoft Academic Search

As in many areas of high relief, debris flows are an important process linkage between hillslopes and the Green River in the canyons of the eastern Uinta Mountains, yet the physical conditions that lead to debris flow initiation are unknown. A recent episode of enhanced debris-flow and wildfire activity provided an opportunity to examine the geomorphic impact of fire and

Isaac J. Larsen; Joel L. Pederson; John C. Schmidt

2006-01-01

155

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

156

Geologic time  

USGS Publications Warehouse

The Earth is very old 4 1/2 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.

2000-01-01

157

Co2 geological sequestration  

SciTech Connect

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

Xu, Tianfu

2004-11-18

158

Mathematical Geology.  

ERIC Educational Resources Information Center

The year 1978 marked a continued trend toward practical applications in mathematical geology. Developments included work in interactive computer graphics, factor analysis, the vanishing tons problem, universal kriging, and resource estimating. (BB)

McCammon, Richard B.

1979-01-01

159

Engineering Geology  

ERIC Educational Resources Information Center

Briefly reviews the increasing application of geologic principles, techniques and data to engineering practices in the areas of land use and zoning controls, resource management energy programs and other fields. (BR)

Lee, Fitzhugh T.

1974-01-01

160

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

161

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

162

Importance of biogeochemical processes in modeling stream chemistry in two watersheds in the Sierra Nevada, California  

Microsoft Academic Search

Two small (0.22 and 0.48 ha) alpine watersheds in the Sierra Nevada of California were studied during the 1992 and 1993 snowmelt seasons to evaluate the importance of soil properties and processes on chemical concentrations in the discharges from each watershed. Watershed 1 was surveyed as having 26% soil cover, whereas watershed 2 was 10% soil covered. Watershed 2 had

Thomas Meixner; Aaron Brownl; Roger C. Bales

1998-01-01

163

Self-Assessment Processes: The Importance of Follow-up for Success  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to review the literature on self-assessment processes and to identify the difficulties, benefits and success factors of the European Foundation for Quality Management self-assessment model, analysing the importance of follow-up. Design/methodology/approach: First, the paper carries out a literature review on…

Tari, Juan Jose

2010-01-01

164

Waiting is the hardest part: Anticipating medical test results affects processing and recall of important information  

Microsoft Academic Search

Waiting for medical test results that signal physical harm can be a stressful and potentially psychologically harmful experience. Despite this, interventionists and physicians often use this wait time to deliver behavior change messages and other important information about the test, possible results and its implications. This study examined how “bracing” for a medical test result impacts cognitive processing, as well

David B. Portnoy

2010-01-01

165

Cellular automata modelling of the cementation process of the Turin (Italy) subsoil conglomerate (``ceppo''),based on a three-dimensional geological model of the city subsoil.  

NASA Astrophysics Data System (ADS)

The Turin (Italy) subsoil is mainly made up by alluvial gravels and sands (Pleistocene), characterised by high cementation degree variability, covered by a thin thickness of loess. These alluvial sediments, of about 40 m deep, overlay lacustrine clays (Villafranchiano), locally heteropic with marine sandstones (Pliocene). The reconstruction of the areal distribution of cementation phenomena of the Turin urban subsoil is of fundamental importance within the context of planning and carrying out works in the city subsoil, as well as for preliminary evaluating the stability of such underground works. Moreover, analyses of spatial distribution of soil cementation could be usefully applied for estimating the propagation of waste-polluted fluids, and for reducing either the natural or human-induced risk, related to the overworking of urban area subsoils. The development of mathematical models commonly needs to deal with several interacting physical and chemical phenomena. A deterministic Cellular Automata (CA) model for the evaluation of cementation processes in the conglomerates of the Turin urban subsoil has recently been developed, by using a three-dimensional geological model of the city subsoil based on boreholes data. The model is able to simulate the spatial distribution of the cementation process in the studied area: it has been derived from two pre-existing CA models, i.e. SCAVATU and CABOTO. Geological, mineralogical-petrographic and sedimentological studies of the soil cementation, and a chemical-physical study of the carbonatic equilibria, have first been carried out. These studies pointed out the presence of meniscus cements (which suggest a meteoric diagenesis) and gave fundamental cues for the development of base hypothesis on the genesis of cementation in the considered area. A macroscopic Cellular Automata model has accordingly been developed, in order to simulate the principal phenomena which take place during the cementation process. The model has a ''layered structure'', composed of the following three layers: 1) the first quantitatively describes pluviometric events in the Turin area. The global amount of rain is subdivided into ''run-off'' and ''infiltration'', by using the c.i.p. value. This layer concerns only the space region in which the run-off occurs: such cells have been classified as ''A'' type. 2) the second layer describes the fluid flow of ''water'' through the soil (i.e. loess and conglomerate). It concerns the space region of the Turin subsoil: such cells have been classified as ''B'' type. 3) the third layer describes the chemical-physical phenomena of ''solute transport'', ''diffusion and chemical reactions of dissolution'', and ''precipitation of calcium carbonate''. Inside the above mentioned cells, the chemical-physical phenomena are allowed to occur. Owing to their high complexity, the global phenomena under consideration have been decomposed into ''elementary'' processes (run-off, infiltration and chemical-physical reactions) and properly translated into CA local rules. The model, opportunely implemented in a parallel computing environment, allows to simulate the process of cementation of the Turin urban subsoil: as mentioned above, it could be therefore usefully applied for mitigating natural and man-induced hazards in the study area.

Bello, S.; de Rienzo, F.; Nardi, G.

2003-04-01

166

Slope processes in weathred volcaniclastic rocks of the Camaldoli hill (Naples, Italy): geological, structural and volcanological aspects  

Microsoft Academic Search

The Camaldoli hill is the remnant of the north-eastern margin of the Campi Flegrei caldera (CFc), generated by two main collapses related to the Campanian Ignimbrite (CI; 39 ka) and Neapolitan Yellow Tuff (NYT; 15 ka) eruptions. We have reconstructed its geological, lithological and structural features, and their effects on slope instability. The backbone of the hill includes the remnants

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

2003-01-01

167

Tectonomagmatic evolution of the terrestrial planets: importance for understanding of processes of their formation and subsequent development  

NASA Astrophysics Data System (ADS)

Our knowledge about formation and evolution of the terrestrial planets (the Earth, Venus, Mars, Mercury and, possibly, the Moon) based on different physical and geochemical speculations and models. The main disadvantage of such hypotheses is their abstract character and ignoring any data on tectonomagmatic evolution of those planets. At the same time, just this type of data provide an important information, which is necessary for elaborating of a present-day theory of their formation and evolution. The Earth has been much better studied compared to the other planets, therefore we will discuss the main questions of planetary tectonomagmatic evolution using the Earth as example plus involve other data on the Moon and the terrestrial planets. Two dominating hypotheses about composition of the primordial Earth's crust exist now: (1) traditional implies that the primordial crust had basic composition, whereas the sialic crust resulted from a geosyncline process or, in modern terms, from processes at convergent plate margins, and (2) primordial crust was sialic; the plate tectonic mechanisms started in the Middle Paleoproterozoic and resulted in oceanic spreading and formation of the secondary oceanic crust. Both models require a global melting of a primary chondritic material to form the primordial crust. The final result depends on the degree of melt differentiation during solidification of a magmatic ocean. Such a solidification, due to differences between adiabatic and melting-points gradients had to proceed in bottom-top direction (Jeffries, 1929) and resulted in accumulation of low-temperature derivates in the primordial crust. Geological data, namely granite-dominated Archean crust, and results of studying of detrital zircon from Australia supports the primordial-sialic crust hypothesis. The Moon which is four times smaller than Earth has a basic primordial crust. Such a difference can be explained by different depths of their magmatic oceans. The Early Precambrian (Archean, Early Paleoproterozoic) tectonomagmatic activity on the Earth was rather different from the Phanerozoic: the major features then were huge granite-greenstone terranes (GGTs) and their separating granulite belts; mantle melts were derived from a depleted source. The GGTs consisting of greenstone belts with komatiite-basaltic magmatism in Archean, "submerged" in granite gneiss matrix, probably, strong reworked primordial sialic crust, and by siliceous high-Mg series (SHMS) in early Paleoproterozoic. GGTs were areas of extension, uplifting and denudation, whereas the granulite belts were dominated by compression, sinking and sedimentation. Generally, the Early Precambrian geological pattern was rather different from the modern plate tectonics and can be described in plumetectonics terms. A drastic change of the tectonomagamtic and ecology processes on it's surface occurred at ca. 2.3-2.0 Ga: instead of high-Mg magmas appeared geochemical enriched Fe-Ti pucrites and basalts, and the plume tectonic was changed by plate tectonics, which is still active now, as well as ecologic situation on the surface. Since that time the primordial sialic continental crust has been gradually replaced by the secondary basaltic oceanic crust. Systematic consumption of the ancient crust in subduction zones obviously started at ~2 Ga and led to gradually replacing it by the secondary mafic (oceanic) crust. The crustal materials has stored in the "slab cemeteries", revealed in the mantle by seismic tomography. Tectonomagmatic evolution of the Moon began4.4-4.0 Ga in lunar highlands with low-Ti magnesium suite, analogous to the terrestrial Paleoproterozoic SHMS. Cardinal change of tectonomagmatic processes, close to that on the Earth, happed on the Moon ~3.9 Ga to form large depressions of lunar maria with thinned crust and vast basaltic volcanism with signatures of plume magmatism (high-Ti basalts). The lunar maria were, probably, specific analogues of Earth's oceans. On Venus and Mars also two main types of morphostructures, which are vast fields of basal

Sharkov, E.; Bogatikov, O.

2009-04-01

168

Effects of climatic and geological processes during the pleistocene on the evolutionary history of the northern cavefish, Amblyopsis spelaea (teleostei: amblyopsidae).  

PubMed

Climatic and geological processes associated with glaciation cycles during the Pleistocene have been implicated in influencing patterns of genetic variation and promoting speciation of temperate flora and fauna. However, determining the factors promoting divergence and speciation is often difficult in many groups because of our limited understanding of potential vicariant barriers and connectivity between populations. Pleistocene glacial cycles are thought to have significantly influenced the distribution and diversity of subterranean invertebrates; however, impacts on subterranean aquatic vertebrates are less clear. We employed several hypothesis-driven approaches to assess the impacts of Pleistocene climatic and geological changes on the Northern Cavefish, Amblyopsis spelaea, whose current distribution occurs near the southern extent of glacial advances in North America. Our results show that the modern Ohio River has been a significant barrier to dispersal and is correlated with patterns of genetic divergence. We infer that populations were isolated in two refugia located north and south of the Ohio River during the most recent two glacial cycles with evidence of demographic expansion in the northern isolate. Finally, we conclude that climatic and geological processes have resulted in the formation of cryptic forms and advocate recognition of two distinct phylogenetic lineages currently recognized as A. spelaea. PMID:23550752

Niemiller, Matthew L; McCandless, James R; Reynolds, R Graham; Caddle, James; Near, Thomas J; Tillquist, Christopher R; Pearson, William D; Fitzpatrick, Benjamin M

2012-12-20

169

Pennsylvania Geology  

NSDL National Science Digital Library

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

170

Geological pattern formation by growth and dissolution in aqueous systems  

Microsoft Academic Search

Although many geological processes take place on time scales that are very long compared with the human experience, essentially all geological processes, fast or slow, are far from equilibrium processes. Surprisingly often, geological processes lead to the formation of quite simple and distinctive patterns, which hint at an underlying simplicity in many complex geological systems.. The ability to predict the

Paul Meakin; B. Jamtveit

2009-01-01

171

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

172

General Surveillance for Import and Processing: the EuropaBio approach  

Microsoft Academic Search

:  Applications for placing on the market of genetically modified organisms (GMOs) for import, food, feed and processing under\\u000a Directive 2001\\/18\\/EC and Regulation (EC) No 1829\\/ 2003, have to include a monitoring plan conforming with Annex VII to Directive\\u000a 2001\\/18\\/EC. One aspect of this monitoring plan is the need for general surveillance to identify the occurrence of adverse\\u000a effects of the

P. Windels; E. Alcalde; E. Lecoq; G. Legris; A. Pleysier; B. Tinland; C. Wandelt

2009-01-01

173

Self-assessment processes: the importance of follow-up for success  

Microsoft Academic Search

Purpose – The purpose of this paper is to review the literature on self-assessment processes and to identify the difficulties, benefits and success factors of the European Foundation for Quality Management self-assessment model, analysing the importance of follow-up. Design\\/methodology\\/approach – First, the paper carries out a literature review on self-assessment, and then it uses the case study methodology based on

Juan José Tarí

2010-01-01

174

Species sorting and neutral processes are both important during the initial assembly of bacterial communities  

PubMed Central

Many studies have shown that species sorting, that is, the selection by local environmental conditions is important for the composition and assembly of bacterial communities. On the other hand, there are other studies that could show that bacterial communities are neutrally assembled. In this study, we implemented a microcosm experiment with the aim to determine, at the same time, the importance of species sorting and neutral processes for bacterial community assembly during the colonisation of new, that is, sterile, habitats, by atmospheric bacteria. For this we used outdoor microcosms, which contained sterile medium from three different rock pools representing different environmental conditions, which were seeded by rainwater bacteria. We found some evidence for neutral assembly processes, as almost every 4th taxon growing in the microcosms was also detectable in the rainwater sample irrespective of the medium. Most of these taxa belonged to widespread families with opportunistic growth strategies, such as the Pseudomonadaceae and Comamonadaceae, indicating that neutrally assembled taxa may primarily be generalists. On the other hand, we also found evidence for species sorting, as one out of three media selected a differently composed bacterial community. Species sorting effects were relatively weak and established themselves via differences in relative abundance of generalists among the different media, as well as media-specific occurrences of a few specific taxa. In summary, our results suggest that neutral and species sorting processes interact during the assembly of bacterial communities and that their importance may differ depending on how many generalists and specialists are present in a community.

Langenheder, Silke; Szekely, Anna J

2011-01-01

175

Geologic Time  

NSDL National Science Digital Library

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

Heaton, Timothy

176

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

177

Status report on the geology of the Oak Ridge Reservation  

SciTech Connect

This report provides an introduction to the present state of knowledge of the geology of the Oak Ridge Reservation (ORR) and a cursory introduction to the hydrogeology. An important element of this work is the construction of a modern detailed geologic map of the ORR (Plate 1), which remains in progress. An understanding of the geologic framework of the ORR is essential to many current and proposed activities related to land-use planning, waste management, environmental restoration, and waste remediation. Therefore, this report is also intended to convey the present state of knowledge of the geologic and geohydrologic framework of the ORR and vicinity and to present some of the available data that provide the basic framework for additional geologic mapping, subsurface geologic, and geohydrologic studies. In addition, some recently completed, detailed work on soils and other surficial materials is included because of the close relationships to bedrock geology and the need to recognize the weathered products of bedrock units. Weathering processes also have some influence on hydrologic systems and processes at depth.

Hatcher, R.D. Jr.; Lemiszki, P.J.; Foreman, J.L. [Tennessee Univ., Knoxville, TN (United States). Dept. of Geological Sciences; Dreier, R.B.; Ketelle, R.H.; Lee, R.R.; Lee, Suk Young [Oak Ridge National Lab., TN (United States); Lietzke, D.A. [Lietzke (David A.), Rutledge, TN (United States); McMaster, W.M. [McMaster (William M.), Heiskell, TN (United States)

1992-10-01

178

How important is vehicle safety in the new vehicle purchase process?  

PubMed

Whilst there has been a significant increase in the amount of consumer interest in the safety performance of privately owned vehicles, the role that it plays in consumers' purchase decisions is poorly understood. The aims of the current study were to determine: how important vehicle safety is in the new vehicle purchase process; what importance consumers place on safety options/features relative to other convenience and comfort features, and how consumers conceptualise vehicle safety. In addition, the study aimed to investigate the key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase. Participants recruited in Sweden and Spain completed a questionnaire about their new vehicle purchase. The findings from the questionnaire indicated that participants ranked safety-related factors (e.g., EuroNCAP (or other) safety ratings) as more important in the new vehicle purchase process than other vehicle factors (e.g., price, reliability etc.). Similarly, participants ranked safety-related features (e.g., advanced braking systems, front passenger airbags etc.) as more important than non-safety-related features (e.g., route navigation systems, air-conditioning etc.). Consistent with previous research, most participants equated vehicle safety with the presence of specific vehicle safety features or technologies rather than vehicle crash safety/test results or crashworthiness. The key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase were: use of EuroNCAP, gender and education level, age, drivers' concern about crash involvement, first vehicle purchase, annual driving distance, person for whom the vehicle was purchased, and traffic infringement history. The findings from this study are important for policy makers, manufacturers and other stakeholders to assist in setting priorities with regard to the promotion and publicity of vehicle safety features for particular consumer groups (such as younger consumers) in order to increase their knowledge regarding vehicle safety and to encourage them to place highest priority on safety in the new vehicle purchase process. PMID:18460367

Koppel, Sjaanie; Charlton, Judith; Fildes, Brian; Fitzharris, Michael

2007-12-18

179

Import for export; reporting and recordkeeping requirements for unapproved or violative products imported for further processing or incorporation and subsequent export--FDA. Proposed rule.  

PubMed

The Food and Drug Administration (FDA) is proposing reporting and recordkeeping regulations to implement certain sections of the Federal Food, Drug, and Cosmetic Act (the act) as amended by the FDA Export Reform and Enhancement Act of 1996. The proposed rule would require an importer to report to FDA each time it imports an unapproved or otherwise violative article that is to be exported after further processing or incorporation into another product in the United States and to keep records to ensure that the article is so processed or incorporated and then exported, and that any portion of the import that is not exported is destroyed. PMID:10338872

1998-11-24

180

Principles of nuclear geology  

Microsoft Academic Search

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

Aswathanarayana

1985-01-01

181

Project Primary Geology  

NSDL National Science Digital Library

Project Primary is a collaboration of professors from the departments of Botany-Microbiology, Chemistry, Education, Geology, Physics, and Zoology at Ohio Wesleyan University and K-3 teachers from Ohio's Delaware, Marion, and Union Counties to produce hands-on activities for the teaching of science. The geology activities are appropriate for children in grades K-12. Collectively, the goals for these activities are to demonstrate the inter-relatedness of life and the physical planet, the importance of understanding scientific phenomena for all people, not just future scientists, to impart knowledge which leads through student curiosity to continued inquiry, and to spur creativity. Topics covered include earthquakes, behavior of Earth materials, plate tectonics, the surface of the Earth, volcanoes, and geologic time and the evolution of the Earth.

Fryer, Karen

182

Surficial Geologic Map of Maine  

NSDL National Science Digital Library

In this activity students become familiar with the nature and use of the Surficial Geologic Map of Maine and gain practice in using maps other than topographic maps. They will discover that surficial geology deals primarily with the geologically youthful, unconsolidated sedimentary materials that exist at, or close to the surface of a specific area and are important because the surface deposits filter and control the access of water to the water table. Students also learn that the study of surficial geology is important for siting of waste disposal facilities and for resources such as sand, gravel, and clay. Although this activity was written for a map of Maine, it will work in any state where surficial geological maps are available.

183

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

184

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

185

Measuring student understanding of geological time  

Microsoft Academic Search

There have been few discoveries in geology more important than deep time - the understanding that the universe has existed for countless millennia, such that man's existence is confined to the last milliseconds of the metaphorical geological clock. The influence of deep time is felt in a variety of sciences including geology, cosmology, and evolutionary biology. Thus, any student that

Jeff Dodick; Nir Orion

2003-01-01

186

Measuring Student Understanding of Geological Time  

ERIC Educational Resources Information Center

|There have been few discoveries in geology more important than "deep time"--the understanding that the universe has existed for countless millennia, such that man's existence is confined to the last milliseconds of the metaphorical geological clock. The influence of deep time is felt in a variety of sciences including geology, cosmology, and…

Dodick, Jeff; Orion, Nir

2003-01-01

187

Geological features indicative of processes related to the hematite formation in Meridiani Planum and Aram Chaos, Mars: a comparison with diagenetic hematite deposits in southern Utah, USA  

NASA Astrophysics Data System (ADS)

In order to understand the formation of the few but large, hematite deposits on Mars, comparisons are often made with terrestrial hematite occurrences. In southern Utah, hematite concretions have formed within continental sandstones and are exposed as extensive weathered-out beds. The hematite deposits are linked to geological and geomorphological features such as knobs, buttes, bleached beds, fractures and rings. These terrestrial features are visible in aerial and satellite images, which enables a comparison with similar features occurring extensively in the martian hematite-rich areas. The combination of processes involved in the movement and precipitation of iron in southern Utah can provide new insights in the context of the hematite formation on Mars. Here we present a mapping of the analogue geological and geomorphological features in parts of Meridiani Planum and Aram Chaos. Based on mapping comparisons with the Utah occurrences, we present models for the formation of the martian analogues, as well as a model for iron transport and precipitation on Mars. Following the Utah model, high albedo layers and rings in the mapped area on Mars are due to removal or lack of iron, and precipitation of secondary diagenetic minerals as fluids moved up along fractures and permeable materials. Hematite was precipitated intraformationally where the fluid transporting the reduced iron met oxidizing conditions. Our study shows that certain geological/geomorphological features can be linked to the hematite formation on Mars and that pH differences could suffice for the transport of the iron from an orthopyroxene volcanoclastic source rock. The presence of organic compounds can enhance the iron mobilization and precipitation processes. Continued studies will focus on possible influence of biological activity and/or methane in the formation of the hematite concretions in Utah and on Mars.

Ormö, Jens; Komatsu, Goro; Chan, Marjorie A.; Beitler, Brenda; Parry, William T.

2004-10-01

188

Cruciform structures are a common DNA feature important for regulating biological processes.  

PubMed

DNA cruciforms play an important role in the regulation of natural processes involving DNA. These structures are formed by inverted repeats, and their stability is enhanced by DNA supercoiling. Cruciform structures are fundamentally important for a wide range of biological processes, including replication, regulation of gene expression, nucleosome structure and recombination. They also have been implicated in the evolution and development of diseases including cancer, Werner's syndrome and others.Cruciform structures are targets for many architectural and regulatory proteins, such as histones H1 and H5, topoisomerase II?, HMG proteins, HU, p53, the proto-oncogene protein DEK and others. A number of DNA-binding proteins, such as the HMGB-box family members, Rad54, BRCA1 protein, as well as PARP-1 polymerase, possess weak sequence specific DNA binding yet bind preferentially to cruciform structures. Some of these proteins are, in fact, capable of inducing the formation of cruciform structures upon DNA binding. In this article, we review the protein families that are involved in interacting with and regulating cruciform structures, including (a) the junction-resolving enzymes, (b) DNA repair proteins and transcription factors, (c) proteins involved in replication and (d) chromatin-associated proteins. The prevalence of cruciform structures and their roles in protein interactions, epigenetic regulation and the maintenance of cell homeostasis are also discussed. PMID:21816114

Brázda, Václav; Laister, Rob C; Jagelská, Eva B; Arrowsmith, Cheryl

2011-08-05

189

From seed production to seedling establishment: Important steps in an invasive process  

NASA Astrophysics Data System (ADS)

It is widely accepted that exotic invasive species are one of the most important ecological and economic problems. Reproductive and establishment traits are considered key features of a population expansion process, but few works have studied many of these simultaneously. This work examines how large the differences are in reproductive and establishment traits between two Fabaceae, the exotic invasive, Gleditsia triacanthos and the native, Acacia aroma. Gleditsia is a serious leguminous woody invader in various parts of the world and Acacia is a common native tree of Argentina. Both species have similar dispersal mechanisms and their reproductive phenology overlaps. We chose 17 plants of each species in a continuous forest of the Chaco Serrano Forest of Córdoba, Argentina. In each plant we measured fruit production, fruit removal (exclusion experiments), seed predation (pre- and post-dispersal), seed germination, seed bank (on each focal tree, three sampling periods during the year), and density of seedlings (around focal individuals and randomly in the study site). Gleditsia presented some traits that could favour the invasion process, such as a higher number of seeds per plant, percentage of scarified seed germination and density of seedlings around the focal individuals, than Acacia. On the other hand, Gleditsia presented a higher percentage of seed predation. The seed bank was persistent in both species and no differences were observed in fruit removal. This work highlights the importance of simultaneously studying reproductive and establishment variables involved in the spreading of an exotic invasive species. It also gives important insight into the variables to be considered when planning management strategies. The results are discussed from the perspective of some remarkable hypotheses on invasive species and may contribute to rethinking some aspects of the theory on invasive species.

Ferreras, Ana Elisa; Galetto, Leonardo

2010-03-01

190

Product or waste? Importation and end-of-life processing of computers in Peru.  

PubMed

This paper considers the importation of used personal computers (PCs) in Peru and domestic practices in their production, reuse, and end-of-life processing. The empirical pillars of this study are analysis of government data describing trade in used and new computers and surveys and interviews of computer sellers, refurbishers, and recyclers. The United States is the primary source of used PCs imported to Peru. Analysis of shipment value (as measured by trade statistics) shows that 87-88% of imported used computers had a price higher than the ideal recycle value of constituent materials. The official trade in end-of-life computers is thus driven by reuse as opposed to recycling. The domestic reverse supply chain of PCs is well developed with extensive collection, reuse, and recycling. Environmental problems identified include open burning of copper-bearing wires to remove insulation and landfilling of CRT glass. Distinct from informal recycling in China and India, printed circuit boards are usually not recycled domestically but exported to Europe for advanced recycling or to China for (presumably) informal recycling. It is notable that purely economic considerations lead to circuit boards being exported to Europe where environmental standards are stringent, presumably due to higher recovery of precious metals. PMID:19731711

Kahhat, Ramzy; Williams, Eric

2009-08-01

191

Isotopic Heterogeneity and Mantle Stirring: Importance of Early Versus Late Processes  

NASA Astrophysics Data System (ADS)

Mid-ocean ridge basalts (MORBs) that make up the bulk of the oceanic crust (OC) exhibit a relatively uniform isotopic composition. In particular, Sm-Nd isotopic results, suggests that their mantle source had been depleted (the depleted mantle or DM) by melt extraction to form the continental crust (CC) over geologic time with a mean age of extraction of 1.8 Ga. With reservoir models that take into account mantle heterogeneities by keeping track of all sub-reservoirs in DM we have established that the most frequent MORB isotopic compositions faithfully record the average isotopic composition of DM. Mass balance considerations based on Nd and Sr isotopic thus still suggest that mass of the DM is only about 30 % of the mantle. The lower mantle could thus in principle have a composition close to the bulk silicate Earth. We have a good model for sampling the DM but need a better understanding of its location/distribution in the mantle. It is now well established that 146Sm was live in the early Solar System and that samples from Isua, W. Greenland (~ 3.8 Ga old) have high 142Nd/144Nd values when compared to normal terrestrial Nd. This demonstrates that the earliest mantle differentiation (likely in a magma ocean) happened within 100 Myr of Solar System formation and has opened up possibilities for better understanding the earliest part of mantle evolution. Basalts from ocean islands show a much wider range in isotopic composition than MORBs. Their (and MORB) Nd, Sr and Pb isotope data can be described rather well by four isotopic components: DMM, HIMU, EMI, EMII. Many of the OIB data arrays point toward an isotopic component called FOZO or C. Our current analysis shows that these apparent isotopic components are non-existent or fictitious components/reservoirs. The real components are never seen because of the averaging that happens when basaltic melts sample the mantle. In particular, the isotopic composition of FOZO corresponds closely to the average composition of the matrix in the DM, which consists of small length- scale sub-reservoirs (<15km). Part of OIB or plume isotopic signatures are likely to originate in the lower mantle or the D" layer. The isotopic evidence suggests that the lower mantle was completely molten during part of the early magma ocean stage. Recent suggestions that the D" layer formed by foundering of a very early enriched crust is incompatible with the fact that the mean age of differentiation of the DM-CC system is on the order of 2 Ga (as shown by long-lived chronometers). Long-lived chronometers are of course much more reliable in giving us the long-term evolution of major earth reservoirs. However, extinct nuclides can give us a view into early processes that are not at all or only poorly recorded by the long-lived chronometers. We need better models for how plumes sample the mantle to make good use of the isotopic data on plume basalts.

Jacobsen, S. B.; O'Connell, R. J.; Ranen, M. C.; Kellogg, J. B.

2007-12-01

192

Triangular framework mesh generation of 3D geological structure  

NASA Astrophysics Data System (ADS)

The dynamic simulation of oil migration and accumulation is an important issue on the research of petroleum exploration, and it is a numerical simulation process with special requirement on the framework mesh of 3D geological models, which means that the mesh should have same geometry and topology relation near the intersected part of geological surfaces. In this paper, basing on the conforming Delaunay triangulation algorithm to construct mesh of individual geological stratum or fault, a novel link-Delaunay-triangulation method is presented to achieve the geometric and topological consistency in the intersected line between two surfaces, also with the analysis of termination of our algorithm. Finally, some examples of the geological framework mesh are provided and the experimental result proved that the algorithm's effectiveness in engineering practice.

Meng, Xianhai; Zhou, Kun; Li, Jigang; Yang, Qin

2013-03-01

193

Waiting is the hardest part: Anticipating medical test results affects processing and recall of important information.  

PubMed

Waiting for medical test results that signal physical harm can be a stressful and potentially psychologically harmful experience. Despite this, interventionists and physicians often use this wait time to deliver behavior change messages and other important information about the test, possible results and its implications. This study examined how "bracing" for a medical test result impacts cognitive processing, as well as recall of information delivered during this period. Healthy U.S. university students (N = 150) were tested for a deficiency of a fictitious saliva biomarker that was said to be predictive of long-term health problems using a 2 (Test Result) x 2 (Expected immediacy of result: 10 min, 1 month) factorial design. Participants expecting to get the test result shortly should have been bracing for the result. While waiting for the test results participants completed measures of cognitive processing. After participants received the test result, recall of information about the biomarker was tested in addition to cognitive measures. One week later, participants who were originally told they did not have the deficiency had their recall assessed again. Results showed that anticipating an imminent test result increased cognitive distraction in the processing of information and lowered recall of information about the test and the biomarker. These results suggest that delivering critical information to patients after administering a test and immediately before giving the results may not be optimal. PMID:20570029

Portnoy, David B

2010-05-01

194

Waiting is the hardest part: anticipating medical test results affects processing and recall of important information.  

PubMed

Waiting for medical test results that signal physical harm can be a stressful and potentially psychologically harmful experience. Despite this, interventionists and physicians often use this wait time to deliver behavior change messages and other important information about the test, possible results and its implications. This study examined how "bracing" for a medical test result impacts cognitive processing, as well as recall of information delivered during this period. Healthy U.S. university students (N = 150) were tested for a deficiency of a fictitious saliva biomarker that was said to be predictive of long-term health problems using a 2 (Test Result) x 2 (Expected immediacy of result: 10 min, 1 month) factorial design. Participants expecting to get the test result shortly should have been bracing for the result. While waiting for the test results participants completed measures of cognitive processing. After participants received the test result, recall of information about the biomarker was tested in addition to cognitive measures. One week later, participants who were originally told they did not have the deficiency had their recall assessed again. Results showed that anticipating an imminent test result increased cognitive distraction in the processing of information and lowered recall of information about the test and the biomarker. These results suggest that delivering critical information to patients after administering a test and immediately before giving the results may not be optimal. PMID:20556876

Portnoy, David B

2010-07-01

195

Tour of Park Geology: Shoreline Geology  

NSDL National Science Digital Library

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

196

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

USGS Publications Warehouse

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

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

2012-01-01

197

Structural and stratigraphic evolution of the central Mississippi Canyon area: Interaction of salt tectonics and slope processes in the formation of engineering and geologic hazards  

NASA Astrophysics Data System (ADS)

Approximately 720 square miles of digital 3-dimensional seismic data covering the eastern Mississippi Canyon area, Gulf of Mexico, continental shelf was used to examine the structural and stratigraphic evolution of the geology in the study area. The analysis focused on salt tectonics and sequence stratigraphy to develop a geologic model for the study area and its potential impact on engineering and geologic hazards. Salt in the study area was found to be established structural end-members derived from shallow-emplaced salt sheets. The transition from regional to local salt tectonics was identified through structural deformation of the stratigraphic section on the seismic data and occurred no later than ˜450,000 years ago. From ˜450,000 years to present, slope depositional processes have become the dominant geologic process in the study area. Six stratigraphic sequences (I-VI) were identified in the study area and found to correlate with sequences previously defined for the Eastern Mississippi Fan. Condensed sections were the key to the correlation. The sequence stratigraphy for the Eastern Mississippi Fan can be extended ˜28 miles west, adding another ˜720 square miles to the interpreted Fan. A previously defined channel within the Eastern Fan was identified in the study area and extended the channel ˜28 miles west. Previous work on the Eastern Fan identified the source of the Fan to be the Mobile River; however, extending the channel west suggests the sediment source to be from the Mississippi River, not the Mobile River. Further evidence for this was found in ponded turbidites whose source has been previously established as the Mississippi River. Ages of the stratigraphic sequences were compared to changes in eustatic sea level. The formation stratigraphic sequences appear decoupled from sea level change with "pseudo-highstands" forming condensed sections during pronounced Pleistocene sea level lowstands. Miocene and Pleistocene depositional analogues suggest the location of the shifting Mississippi River Pleistocene depocenter is a more dominant influence on sequence formation. Thus, the application of traditional sequence interpretation with respect to sea level change should be reconsidered to also account for the shifting depocenter for both the study area as well as the broader Eastern Mississippi Fan.

Brand, John Richard

198

Frequency response and distortion properties of nonlinear image processing algorithms and the importance of imaging context.  

PubMed

Purpose: The most common metrics for resolution analysis in medical imaging are valid only for (approximately) linear systems. While analogues to these metrics have been used in attempts to describe resolution performance in nonlinear systems, the analysis is incomplete since distortion effects are often ignored. The authors have developed a methodology to analyze the amplitude modulation and waveform distortion properties of nonlinear systems with specific application to medical image processing algorithms.Methods: Using sinusoidal basis functions, two metrics were derived which distinguish amplitude modulation from nonlinear waveform distortion: principle frequency response and distortion power spectrum, respectively. Additionally, two figures of merit were developed to describe the relative impact of nonlinear distortion as a result of image processing: distortion index (DI) and ?DI. Three nonlinear denoising algorithms, the median, bilateral, and wavelet denoising filters, were selected as example functions to demonstrate the utility of the metrics derived in this study.Results: Each filter showed very different resolution and waveform distortion properties. In particular, the amplitude and extent of nonlinear distortion depended strongly on image context and the type of nonlinear mechanism employed. Nonlinear waveform distortion constituted up to 30% of the median filter output signal power in high contrast-to-noise ratio (CNR) scenarios. Conversely, nonlinear distortion never exceeded 1% of the bilateral filter output signal power. The wavelet denoising response contained between 1% and 9% distortion which varied weakly as a function of CNR.Conclusions: The analytical metrics described in the paper demonstrate the importance of considering both resolution- and distortion-related effects in characterizing the performance of nonlinear imaging systems with specific application to image processing algorithms. Findings with three common nonlinear algorithms demonstrate a range of CNR values over which it is important to consider the impact of the nonlinear nature of each algorithm. Background context is also shown to influence the degree to which the nonlinear nature of the algorithm influences resolution and distortion. While no single metric can yet anticipate observer performance in nonlinear systems, the approach described can demonstrate the range of imaging contexts over which such nonlinear effects are important to consider. PMID:24007157

Wells, Jered R; Dobbins, James T

2013-09-01

199

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.  

Code of Federal Regulations, 2010 CFR

...dried, cured, or processed fruits, vegetables, nuts, and legumes. 319...FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-11 Importation...dried, cured, or processed fruits, vegetables, nuts, and legumes....

2009-01-01

200

7 CFR 319.56-11 - Importation of dried, cured, or processed fruits, vegetables, nuts, and legumes.  

Code of Federal Regulations, 2010 CFR

...dried, cured, or processed fruits, vegetables, nuts, and legumes. 319...FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-11 Importation...dried, cured, or processed fruits, vegetables, nuts, and legumes....

2010-01-01

201

The importance of manufacturing processes and their control for the reliability of CPV systems  

NASA Astrophysics Data System (ADS)

Highly concentrating photovoltaic systems (HCPV) based on III-V multi-junction solar cells entered the PV market recently. Since 2008, HCPV power plants operate in various countries and valuable experiences could be gained. Reliability and durability of CPV power plant components are very much impacting the overall life cycle costs of a CPV power plant. Especially the CPV module is a critical component when considering system life time and overall economics. Soitec's CPV Modules based on Concentrix{trade mark, serif} technology are designed for outstanding robustness and reliability even under harsh environmental conditions. The reliability of a CPV module depends significantly on the manufacturing processes and their control. Therefore it is important to design CPV modules for manufacturability.

Gombert, Andreas; Rubio, Francisca

2013-09-01

202

Plant processes important for the transformation and degradation of explosives contaminants.  

PubMed

Environmental contamination by explosives is a worldwide problem. Of the 20 energetic compounds, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) are the most powerful and commonly used. Nitroamines are toxic and considered as possible carcinogens. The toxicity and persistence of nitroamines requires that their fate in the environment be understood and that contaminated soil and groundwater be remediated. This study, written as a minireview, provides further insights for plant processes important for the transformation and degradation of explosives. Plants metabolize TNT and the distribution of the transformation products, conjugates, and bound residues appears to be consistent with the green liver model concept. Metabolism of TNT in plants occurs by reduction as well as by oxidation. Reduction probably plays an important role in the tolerance of plants towards TNT, and, therefore a high nitroreductase capacity may serve as a biochemical criterion for the selection of plant species to remediate TNT. Because the activities and the inducibilities of the oxidative enzymes are far lower than of nitroreductase, reducing processes may predominate. However, oxidation may initiate the route to conjugation and sequestration leading ultimately to detoxification of TNT, and, therefore, particularly the oxidative pathway deserves more study. It is possible that plants metabolize RDX also according to the green liver concept. In the case of plant metabolism of HMX, a conclusion regarding compliance with the green liver concept was not reached due to the limited number of available data. PMID:15948604

Best, Elly P H; Kvesitadze, G K; Khatisahvili, G; Sadunishvili, T

203

DNA pairing is an important step in the process of targeted nucleotide exchange  

PubMed Central

Modified single-stranded DNA oligonucleotides can direct the repair of genetic mutations in yeast, plant and mammalian cells. The mechanism by which these molecules exert their effect is being elucidated, but the first phase is likely to involve the homologous alignment of the single strand with its complementary sequence in the target gene. In this study, we establish the importance of such DNA pairing in facilitating the gene repair event. Oligonucleotide-directed repair occurs at a low frequency in an Escherichia coli strain (DH10B) lacking the RECA DNA pairing function. Repair activity can be rescued by using purified RecA protein to catalyze the assimilation of oligonucleotide vectors into a plasmid containing a mutant kanamycin resistance gene in vitro. Electroporation of the preformed complex into DH10B cells results in high levels of gene repair activity, evidenced by the appearance of kanamycin-resistant colonies. Gene repair is dependent on the formation of a double-displacement loop (double-D-loop), a recombination intermediate containing two single-stranded oligonucleotides hybridized to opposite strands of the plasmid at the site of the point mutation. The heightened level of stability of the double-D-loop enables it to serve as an active template for the DNA repair events. The data establish DNA pairing and the formation of the double-D-loop as important first steps in the process of gene repair.

Drury, Miya D.; Kmiec, Eric B.

2003-01-01

204

Raising the bar: the importance of hospital library standards in the continuing medical education accreditation process*  

PubMed Central

The Connecticut State Medical Society (CSMS) reviews and accredits the continuing medical education (CME) programs offered by Connecticut's hospitals. As part of the survey process, the CSMS assesses the quality of the hospitals' libraries. In 1987, the CSMS adopted the Medical Library Association's (MLA's) “Minimum Standards for Health Sciences Libraries in Hospitals.” In 1990, professional librarians were added to the survey team and, later, to the CSMS CME Committee. Librarians participating in this effort are recruited from the membership of the Connecticut Association of Health Sciences Librarians (CAHSL). The positive results of having a qualified librarian on the survey team and the invaluable impact of adherence to the MLA standards are outlined. As a direct result of this process, hospitals throughout the state have added staffing, increased space, and added funding for resources during an era of cutbacks. Some hospital libraries have been able to maintain a healthy status quo, while others have had proposed cuts reconsidered by administrators for fear of losing valuable CME accreditation status. Creating a relationship with an accrediting agency is one method by which hospital librarians elsewhere may strengthen their efforts to ensure adequate library resources in an era of downsizing. In addition, this collaboration has provided a new and important role for librarians to play on an accreditation team.

Cyr Gluck, Jeannine; Hassig, Robin Ackley

2001-01-01

205

Geologic controls on radon  

SciTech Connect

This text provides a review of recent research on geological controls of [sup 222]Rn concentrations in soil gas in relation to the problem of high indoor radon concentrations in houses. The importance of the subject matter is highlighted in the preface by the observation that the US Environmental Protection Agency (EPA) estimates that 15,000 to 25,000 deaths result from radon-induced lung cancer each year in the United States. The text contains 8 Chapters: (1) Geology of radon in the United States; (2) Sensitivity of soil radon to geology and the distribution of radon and uranium in the Hylas Zone Area, Virginia; (3) Geologic and environmental implications of high soil-gas radon concentrations in The Great Valley, Jefferson and Berkeley Counties, West Virginia; (4) Soil radon distribution in glaciated areas: an example from the New Jersey Highlands; (5) Radon in the coastal plain of Texas, Alabama, and New Jersey; (6) Effects of weather and soil characteristics on temporal variations in soil-gas radon concentrations; (7) A theoretical model for the flux of radon from rock to ground water; (8) The influence of season, bedrock, overburden, and house construction on airborne levels of radon in Maine homes. The individual chapters are written by different authors in the form of self-contained research papers, each of which is followed by a comprehensive list of references.

Gates, A.E.; Gundersen, L.C.S. (eds.)

1992-01-01

206

Geologic controls on radon  

Microsoft Academic Search

This text provides a review of recent research on geological controls of [sup 222]Rn concentrations in soil gas in relation to the problem of high indoor radon concentrations in houses. The importance of the subject matter is highlighted in the preface by the observation that the US Environmental Protection Agency (EPA) estimates that 15,000 to 25,000 deaths result from radon-induced

A. E. Gates; L. C. S. Gundersen

1992-01-01

207

Accumulation of metals by microorganisms — processes and importance for soil systems  

NASA Astrophysics Data System (ADS)

Metal accumulation by solid substances can counteract metal mobilization in the environment if the solid substance is immobile. Microorganisms have a high surface area-to-volume ratio because of their small size and therefore provide a large contact area that can interact with metals in the surrounding environment. Microbial metal accumulation has received much attention in the last years due to the potential use of microorganisms for cleaning metal-polluted water. However, considerably less attention has been paid to the role of microorganisms for metal mobility in soil even though the same processes may occur there. Therefore, this paper highlights this area. The different accumulation processes that microorganisms perform are analyzed and their potential significance in soil systems is discussed. Different kinds of mechanisms can be involved in the accumulation of metals by microorganisms, e.g. adsorption, precipitation, complexation and active transport into the cell. Physicochemical parameters like pH and ionic composition, as well as biological factors are of importance for the magnitude of accumulation. Often large amounts of metals can be accumulated with varying specificity, and microorganisms may provide nucleation sites for mineral formation. Several studies of microbial metal accumulation have been made with different methods and aims. Most of these studies concern single-component systems with one organism at a time. Data from accumulation experiments with pure cultures of microorganisms have been used to model the overall metal retention in soil. A further development is experimental model systems using various solid soil components in salt medium. Microbial metal accumulation is difficult to study in situ, but some experimental methods have been applied as tools for studying real soil systems, e.g. litter bags buried in soil containing microorganisms, a method where discs with microorganisms have been put onto agar plates with soil extracts, and comparison of sterilized and non-sterilized soils or soils with or without nutrient amendment. Different aspects of microbial metal accumulation are emphasized with the different methods applied. Single-component systems have the advantage of providing excellent information of the metal binding properties of microorganisms but cannot directly be applied to metal behavior in the heterogenous systems that real soils constitute. Studies focused on the behavior of metals in real soils can, in contrast, provide information on the overall metal distribution but less insight into the processes involved. Obviously, a combination of approaches is needed to describe metal distribution and mobility in polluted soil such as areas around mines. Different kinds of multi-component systems as well as modelling may bridge the gap between these two types of studies. Several experimental methods, complementary to each other and designed to allow for comparison, may emphasize different aspects of metal accumulation and should therefore be considered. To summarize, there are studies that indicate that microorganisms may also accumulate metals in soil and that the amounts may be considerable. However, much work remains to be done, with the focus of microorganisms in soil. It is also important to put microbial metal accumulation in relation to other microbial processes in soil, which can influence metal mobility, to determine the overall influence of soil microorganisms on metal mobility, and to be able to quantify these processes.

Ledin, Maria

2000-08-01

208

Universal and important physical process in space plasmas: electric charge separation  

NASA Astrophysics Data System (ADS)

One of the scientific IHY aims is the study of universal physical processes that affect the interplanetary and terrestrial environment. Separation of electric charges (ions and electrons) plays an important, but poorly investigated role in space physics and in space plasmas especially. This universal physical process and the opposite phenomenon of charge neutralization coexist and lead to formation and removal of appreciable potential electric fields and discharges on the Sun, in the heliosphere, magnetosphere, ionosphere and atmosphere. In this paper, examples will be presented of estimated potential electric fields on the Sun and in the heliosphere based on theoretical arguments and available observational indications. Electric charge is a fundamental property of matter. The regimes of electric charge separation and accumulation are different in solids, liquids, plasmas and gaseous media. In plasmas around thermodynamic equilibrium potential electric fields experience the Debye-H¨ckel screening, but it is often strongly violated u in situations outside of equilibrium. Inductive electric fields are divergent-less and have no sources by definition. They arise due time variable magnetic fields (Faraday induction). Potential (Coulomb) fields have the sources - electric charges. The physical role and relative importance of inductive and potential fields can be delimited by the dimensionless parameter - the Faraday number, which is formed by electric current density, electric charge density, the lengthand the timescales of the problem. Induction dominated situations are well known and investigated in space plasma physics, for example, in solar flares and coronal mass ejections (CMEs). Coulomb dominated cases are also clearly occurred especially for small space scales (thin sheets, double layers, discharges etc.) and in case of slowly varying magnetic fields. Solar flares and coronal mass ejections represent specific types of electric discharges. The potential electric fields in solar flares and CMEs are not measured as yet. As a consequence, solar flares and CMEs can be not properly understood without this information. Knowledge of electric charges, potential electric fields, as well as electric currents and magnetic fields is necessary together with plasma parameters for this purpose. Electric charges and Coulomb fields are still elusive in the solar atmosphere. Only one known way to improve the situation can be indicated: Stark effect measurements. But they are difficult and not performed in a regular way on the Sun. As a result, our understanding of solar activity processes and their consequences remains incomplete and limited by available MHD cartoons and simplified kinetic models, which are not always justified by observations and appear to be far from reality in many instances. This study was supported by the RFBR grants 07-02-00147, 06-05-64500, INTAS 03-51-6202 and MSU Interdisciplinary Scientific Project. It is also fulfilled as a part of the Programs of the Russian Academy of Sciences: "Origin and evolution of stars and galaxies" (P-04), "Solar activity and physical processes in the Sun-Earth system" (P-16, Part 3) and "Plasma processes in the Solar system (OFN-16)".

Veselovsky, Igor

209

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

210

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

211

Quantifying the importance of galactic cosmic rays in cloud microphysical processes  

NASA Astrophysics Data System (ADS)

Galactic Cosmic Rays are one of the major sources of ion production in the troposphere and stratosphere. Recent studies have shown that ions form electrically charged clusters which may grow to become cloud droplets. Aerosol particles charge by the attachment of ions and electrons. The collision efficiency between a particle and a water droplet increases, if the particle is electrically charged, and thus aerosol-cloud interactions can be enhanced. Because these microphysical processes may change radiative properties of cloud and impact Earth's climate it is important to evaluate these processes' quantitative effects. Five different models developed independently have been coupled to investigate this. The first model estimates cloud height from dew point temperature and the temperature profile. The second model simulates the cloud droplet growth from aerosol particles using the cloud parcel concept. In the third model, the scavenging rate of the aerosol particles is calculated using the collision efficiency between charged particles and droplets. The fourth model calculates electric field and charge distribution on water droplets and aerosols within cloud. The fifth model simulates the global electric circuit (GEC), which computes the conductivity and ionic concentration in the atmosphere in altitude range 0-45 km. The first four models are initially coupled to calculate the height of cloud, boundary condition of cloud, followed by growth of droplets, charge distribution calculation on aerosols and cloud droplets and finally scavenging. These models are incorporated with the GEC model. The simulations are verified with experimental data of charged aerosol for various altitudes. Our calculations showed an effect of aerosol charging on the CCN concentration within the cloud, due to charging of aerosols increase the scavenging of particles in the size range 0.1 µm to 1 µm.

Rawal, Akhilesh.; Tripathi, Sachchida Nand.; Michael, Marykutty.; Srivastava, Atul K.; Harrison, Richard G.

2013-09-01

212

ATOMIC PHYSICS PROCESSES IMPORTANT TO THE UNDERSTANDING OF THE SCRAPE-OFF LAYER OF TOKAMAKS  

SciTech Connect

The region between the well-confined plasma and the vessel walls of a magnetic confinement fusion research device, the scrape-off layer (SOL), is typically rich in atomic and molecular physics processes. The most advanced magnetic confinement device, the magnetically diverted tokamak, uses a magnetic separatrix to isolate the confinement zone (closed flux surfaces) from the edge plasma (open field lines). Over most of their length the open field lines run parallel to the separatrix, forming a thin magnetic barrier with the nearby vessel walls. In a poloidally-localized region, the open field lines are directed away from the separatrix and into the divertor, a region spatially separated from the separatrix where intense plasma wall interaction can occur relatively safely. Recent data from several tokamaks indicate that particle transport across the field lines of the SOL can be somewhat faster than previously thought. In these cases, the rate at which particles reach the vessel wall is comparable to the rate to the divertor from parallel transport. The SOL can be thin enough that the recycling neutrals and sputtered impurities from the wall may refuel or contaminate the confinement zone more efficiently than divertor plasma wall interaction. Just inside the SOL is a confinement barrier that produces a sharp pedestal in plasma density and temperature. Understanding neutral transport through the SOL and into the pedestal is key to understanding particle balance and particle and impurity exhaust. The SOL plasma is sufficiently hot and dense to excite and ionize neutrals. Ion and neutral temperatures are high enough that charge exchange between the neutrals and fuel and impurity ions is fast. Excitation of neutrals can be fast enough to lead to nonlinear behavior in charge exchange and ionization processes. In this paper the detailed atomic physics important to the understanding of the neutral transport through the SOL will be discussed.

WEST, W.P.; GOLDSMITH,; B. EVANS,T.E.; OLSON, R.J.

2002-05-01

213

27 CFR 41.1 - Importation of tobacco products, cigarette papers and tubes, and processed tobacco.  

Code of Federal Regulations, 2010 CFR

...tobacco products, cigarette papers and tubes, and processed tobacco. 41.1 Section...TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Scope of Regulations...tobacco products, cigarette papers and tubes, and processed tobacco. This...

2010-04-01

214

40 CFR 761.187 - Reporting importers and by persons generating PCBs in excluded manufacturing processes.  

Code of Federal Regulations, 2010 CFR

...generating PCBs in excluded manufacturing processes. 761.187 Section...generating PCBs in excluded manufacturing processes. In addition to meeting...the definition of excluded manufacturing process at § 761.3,...

2010-07-01

215

40 CFR 761.187 - Reporting importers and by persons generating PCBs in excluded manufacturing processes.  

Code of Federal Regulations, 2010 CFR

...generating PCBs in excluded manufacturing processes. 761.187 Section...generating PCBs in excluded manufacturing processes. In addition to meeting...the definition of excluded manufacturing process at § 761.3,...

2009-07-01

216

Spatial Visualization in Introductory Geology Courses  

NASA Astrophysics Data System (ADS)

Visualization is critical to solving most geologic problems, which involve events and processes across a broad range of space and time. Accordingly, spatial visualization is an essential part of undergraduate geology courses. In such courses, students learn to visualize three-dimensional topography from two-dimensional contour maps, to observe landscapes and extract clues about how that landscape formed, and to imagine the three-dimensional geometries of geologic structures and how these are expressed on the Earth's surface or on geologic maps. From such data, students reconstruct the geologic history of areas, trying to visualize the sequence of ancient events that formed a landscape. To understand the role of visualization in student learning, we developed numerous interactive QuickTime Virtual Reality animations to teach students the most important visualization skills and approaches. For topography, students can spin and tilt contour-draped, shaded-relief terrains, flood virtual landscapes with water, and slice into terrains to understand profiles. To explore 3D geometries of geologic structures, they interact with virtual blocks that can be spun, sliced into, faulted, and made partially transparent to reveal internal structures. They can tilt planes to see how they interact with topography, and spin and tilt geologic maps draped over digital topography. The GeoWall system allows students to see some of these materials in true stereo. We used various assessments to research the effectiveness of these materials and to document visualization strategies students use. Our research indicates that, compared to control groups, students using such materials improve more in their geologic visualization abilities and in their general visualization abilities as measured by a standard spatial visualization test. Also, females achieve greater gains, improving their general visualization abilities to the same level as males. Misconceptions that students carry obstruct learning, but are largely undocumented. Many students, for example, cannot visualize that the landscape in which rock layers were deposited was different than the landscape in which the rocks are exposed today, even in the Grand Canyon.

Reynolds, S. J.

2004-12-01

217

The important challenge to extend spacer DP process towards 22nm and beyond  

NASA Astrophysics Data System (ADS)

Double patterning processes are techniques that can be used to form etching mask patterns for 32nm node and possibly for 22nm node as well. The self-aligned spacer process has drawn much attention as an effective means of enabling the formation of repetitive patterns. The self-aligned spacer process is now being used in actual device manufacturing, but it has many process steps driving up process cost while also assuming a 1D pattern. This paper demonstrates extensions of the self-aligned spacer process by an enhanced 2D positive spacer process and a newly developed spacer DP process using a 1D negative spacer.

Oyama, Kenichi; Nishimura, Eiichi; Kushibiki, Masato; Hasebe, Kazuhide; Nakajima, Shigeru; Murakami, Hiroki; Hara, Arisa; Yamauchi, Shohei; Natori, Sakurako; Yabe, Kazuo; Yamaji, Tomohito; Nakatsuji, Ryota; Yaegashi, Hidetami

2010-03-01

218

Importance of chip selection and elaboration process on the aromatic composition of finished wines.  

PubMed

The evolution of volatile compounds extracted from wood while being macerated for 1 month with four different commercial chips (different geographical origins and toasting degrees) was studied. Furthermore, the effect of the microoxygenation process between alcoholic and malolactic fermentation also was studied. The wood volatile compounds in wines macerated with the four types of chips evolved in the same way. However, the amounts of compounds extracted depended on the type of chip used. There were differences in the levels of vanillin, cis-whiskey lactone, furfural, trans-isoeugenol, and cis-isoeugenol in wines in accordance with the type of wood chips (French or American), and the last two compounds along with 5-methyl furfural presented differences that were directly related to the toast level. However, no effects of microoxygenation treatment on the extraction of volatile compounds extracted from chips were observed. Therefore, the results obtained in this study highlight the importance of chip selection on the aromatic characteristics of finished wines. PMID:18553914

Rodríguez-Bencomo, Juan J; Ortega-Heras, Miriam; Pérez-Magariño, Silvia; González-Huerta, Carlos; González-San José, M Luisa

2008-06-14

219

Importance of microbial soil organic matter processing in dissolved organic carbon production.  

PubMed

Soil dissolved organic carbon (DOC) sources and its seasonal dynamics are poorly known. We aimed to determine the contribution of plant and soil organic matter (SOM) to size classes of DOC in a field experiment with C3 to C4 vegetation change on two soil types through different seasons. Stable isotope ratios of DOC size classes were measured using size exclusion chromatography (SEC) coupled online to liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). SEC resolved DOC into three size classes: very high molecular weight/vHMW (> 10 kDa), high molecular weight/HMW (0.4-10 kDa), and low molecular weight/LMW (< 0.4 kDa). HMW DOC was most abundant in all seasons, soil types, and depths. In contrast, vHMW DOC was only seen postsnowmelt in upper 20 cm and was mainly (87 ± 9%) plant-derived. Through all seasons, HMW and LMW DOC had less than 30% recent plant contribution. Similar size range and source of DOC size classes and soil chloroform fumigation extracts suggest microbial origin of DOC. Thus, microbial SOM recycling is an important process in DOC production. We suggest that DOC molecules get partitioned manifold between soil solution and the mineral matrix (chromatography), thereby getting constantly decomposed, altered, or produced anew by soil microorganisms (reactive transport). PMID:23870024

Malik, Ashish; Gleixner, Gerd

2013-08-07

220

Engineering geology of Stockholm, Sweden  

Microsoft Academic Search

The bedrock in the Stockholm area provides an excellent material for construction. The paper describes the geology of the\\u000a area and provides case histories, mainly related to infrastructure development, illustrating the use of underground construction\\u000a and the importance given to environmental considerations. It discusses the research being undertaken to establish data bases\\u000a which will record the geological and geotechnical information

L. Persson

1998-01-01

221

Process-Response Numerical Modeling in Carbonate Systems - Current Status and Importance (Invited)  

NASA Astrophysics Data System (ADS)

Developing predictive models of carbonate systems has important implications for monitoring and managing global climate change affecting societies around the world. Carbonate sediments and rocks form an important part of the global carbon cycle. More than 80% of Earth’s carbon is locked up in carbonate rocks, and is the primary ultimate sink for CO2 introduced into the atmosphere. Reefs and carbonate platforms, in general, are sensitive climatic indicators, and contain important records of past climate change. Ancient carbonate platforms and systems play a significant role in the global economy. They are the raw material for construction, and through their high permeability’s and porosities, carbonate rocks serve as important fresh water aquifers and petroleum reservoirs. They host more than half of the world’s petroleum. The systems that produce carbonate sediments have multiple interacting biologic, chemical, and hydrodynamic elements. Carbonate sediments are originally and predominantly derived from biological mineralization directly from seawater. Waves, tides, and marine currents can redistribute these sediments landward into lagoons or tidal flats, send them seaward into the deep or sea, or trap them within the hydraulic regime in which they originated. The characteristics of carbonate sediments are thus sensitive to environmental parameters like light, bathymetry, temperature, salinity, turbidity, nutrient and oxygen levels, hydrodynamics, and mineral saturation states. Localized buildups of carbonate sediments can alter the local hydraulic regime and change the nature of surrounding sediments. The prospect of modeling carbonates in detail has been daunting. Existing carbonate models are a class of rule-based ‘simulations’ with limited predictive qualities. The earliest computer models of carbonate deposition were 1-D and 2-D, and essentially modeled carbonates as “in-place” accumulations of sediment. In most cases, sediment production in these models was directly related to water depth based on assumptions that carbonate production is a function of light attenuation with depth. These models were followed by so-called “geometric” models (SedPak), where sediment transport was allowed, and models were based on simply depositing sediment vertically into assumed shoreline geometries. There are computer models of carbonate deposition that model wave and current dynamics over platforms and then base sediment erosion, transport and deposition on the results of the circulation modeling: Carb3D and Carb3D+, Dionysus and Carbonate GPM. In addition, Carb3D+ approximates some diagenetic processes as a function of hydrologic residence times. New types of rule-based models, such as cellular automata have also been developed that model the interaction of many different elements of carbonate deposition. Based on this progress, and with recent advances in ecological modeling, treating uncertainty in models, high performance computing, and handling heterogeneous and linguistic data types, the time is right to tackle the challenges of mathematically modeling carbonate sediments.

Sarg, J.; Jenkins, C. J.; Burgess, P. M.; Budd, D. A.; Rankey, E. C.; Demicco, R. V.

2009-12-01

222

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.

223

Voyager 2 Signatures of Important Processes/Dynamics in the Outer Heliosphere  

NASA Astrophysics Data System (ADS)

We continue investigating the Voyager 2 (V2) Plasma Subsystem (PLS) elevated readings in L-mode on energy/unit charge (E/Q) step 12 on the B-Cup we first reported (Intriligator et al., JGR, 2010) near the termination shock at 84 AU. These elevated B12 readings, which we previously referred to as "high energy ions (HEIs)", are found in the V2 PLS data on the sunward facing B-Cup at E/Q step 12 corresponding to 1610 volts and a proton speed of ~ 600 km/s. In the present paper we update our findings and present V2 data from three years earlier when V2 was in the solar wind in the outer heliosphere (OH) at 73 AU measuring the interplanetary (IP) effects from the October-November (Halloween) 2003 solar events. We also examine other V2 OH time intervals. We show links between solar activity and the elevated B12 readings in the V2 data. We present evidence that these elevated B12 readings appear to be accompanied by significant simultaneous changes in other V2 measurements, including: low energy ions, low energy cosmic rays, anomalous cosmic rays, cosmic ray electrons, interplanetary magnetic field (IMF), and convective solar wind plasma. Our results suggest that the V2 elevated B12 readings may be signatures, tracers, by-products, or indicators of important IP processes such as those associated with intervals of particle acceleration, changes in IMF turbulence, and perhaps local reconnection. This work was funded by NASA Grant NNX08AE40G and by Carmel Research Center, Inc.

Intriligator, D. S.; Intriligator, J.; Miller, W. D.; Webber, W. R.; Decker, R. B.; Sittler, E. C.

2011-12-01

224

Importance of biogeochemical processes in modeling stream chemistry in two watersheds in the Sierra Nevada, California  

NASA Astrophysics Data System (ADS)

Two small (0.22 and 0.48 ha) alpine watersheds in the Sierra Nevada of California were studied during the 1992 and 1993 snowmelt seasons to evaluate the importance of soil properties and processes on chemical concentrations in the discharges from each watershed. Watershed 1 was surveyed as having 26% soil cover, whereas watershed 2 was 10% soil covered. Watershed 2 had greater H+ and nitrogen consumption than watershed 1 but similar cation and sulfate concentrations despite having one fourth the surveyed soil volume per unit area as watershed 1. Daily stream concentrations simulated with the Alpine Hydrochemical Model (AHM) matched the data well, after a systematic model calibration with a subset of the data. We found that the structure of the AHM and the hydrologic parameters developed for the nearby 1.2 km2 Emerald Lake watershed could be applied to these watersheds with only small adjustments; chemical parameters required considerably more adjustment, reflecting a greater degree of chemical versus physical heterogeneity at this scale. Calibration for watershed 2 gave a higher percent base saturation (19 versus 4%) and lower streamversus 10-2.6 atm) than for watershed 1 and three times the soil reactivity (expected) of a field survey. Areas mapped as exposed bedrock in the catchments apparently contributed cations and alkalinity to stream water to a greater extent than did neighboring areas of soil. Areas of exposed bedrock were a larger nitrogen sink than the adjoining areas of soil. The pH and acid-neutralizing capacity of surface runoff in both catchments were less sensitive to changes in atmospheric deposition than at the nearby Emerald Lake watershed. This decreased sensitivity was due to (1) a less pronounced ionic pulse, (2) less retention of sulfate in the soil, and (3) greater nitrate retention.

Meixner, Thomas; Brown, Aaron; Bales, Roger C.

1998-11-01

225

The importance of cochlear processing for the formation of auditory brainstem and frequency following responses.  

PubMed

A model for the generation of auditory brainstem responses (ABR) and frequency following responses (FFRs) is presented. The model is based on the concept introduced by Goldstein and Kiang [J. Acoust. Soc. Am. 30, 107-114 (1958)] that evoked potentials recorded at remote electrodes can theoretically be given by convolution of an elementary unit waveform (unitary response) with the instantaneous discharge rate function for the corresponding unit. In the present study, the nonlinear computational auditory-nerve model recently developed by Heinz et al. [ARLO 2(3), 91-96 (2001)] was used to calculate the instantaneous discharge rate ri(t) for fibers i in the frequency range from 0.1 and 10 kHz. The summed activity across frequency was convolved with a unitary response which is assumed to reflect contributions from different cell populations within the auditory brainstem, recorded at a given pair of electrodes on the scalp. Predicted potential patterns are compared with experimental data for a number of stimulus and level conditions. Clicks, chirps as defined in Dau et al. [J. Acoust. Soc. Am. 107, 1530-1540 (2000)], long-duration stimuli comprising the chirp, as well as tones and slowly varying tonal sweeps were considered. The results demonstrate the importance of considering the effects of the basilar-membrane traveling wave and auditory-nerve processing for the formation of ABR and FFR. Specifically, the results support the hypothesis that the FFR to low-frequency tones represents synchronized activity mainly stemming from mid- and high-frequency units at more basal sites, and not from units tuned to frequencies around the signal frequency. PMID:12597187

Dau, Torsten

2003-02-01

226

Reductive processes controlling arsenic retention: revealing the relative importance of iron and arsenic reduction.  

PubMed

The fate and transport of arsenic is regulated, in part, by its strong affinity for iron (hydr)oxides. A transition from aerobic to anaerobic conditions resulting in concomitant reduction of both As(V) and iron (hydr)oxides can thus have a pronounced influence on As partitioning. However, it is presently unclear whether As desorption under anaerobic conditions results predominantly from a transformation from As(V) to As(III) or from mineralogical changes as a consequence of iron and manganese reduction. Here, we examine desorption of both As(III) and As(V) from ferrihydrite-, goethite-, and hematite-coated sand under hydrodynamic conditions. Furthermore, to resolve the relative role of Fe(III) and/or As(V) reduction in regulating dissolved As concentrations, we also examined As desorption from ferrihydrite- and goethite-coated sands presorbed with As(V) using wild type or mutants of Shewanella sp. ANA-3, capable of Fe(III)- and/or As(V)-reduction. We reveal substantial differences in As(III) and As(V) desorption from ferrihydrite, goethite, and hematite. Despite being adsorbed to a greater extent than As(V), As(III) is desorbed more rapidly and extensively from all oxides, suggesting weaker binding of As(III) than As(V). When As(V) and Fe(III) reduction are decoupled, As(V) reduction appears to be the dominant process controlling As release. Our results also suggest the importance of appreciating physical properties of specific Fe (hydr)oxides when predicting the potential for As desorption. PMID:19068807

Tufano, Katharine J; Reyes, Carolina; Saltikov, Chad W; Fendorf, Scott

2008-11-15

227

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

228

U.S. Processed Food Imports and Exports, 1990-94.  

National Technical Information Service (NTIS)

This bulletin complements the Processed Food Trade Concordance (1995), Agricultural Handbook no. 707, which summarizes the procedures used to convert Bureau of the Census trade data to U.S. processed food industry data. Together, both bulletins provide th...

J. M. Harris

1997-01-01

229

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

230

Coping with errors: the importance of process data in robust sociotechnical systems  

Microsoft Academic Search

This paper presents an analysis of written and electronic records that document the collaborative process of packing museum artifacts in preparation for a move. The majority of data recorded detailed the process of packing, while only a small amount of the data concerned which artifacts were packed in which boxes. Museum staff members were able to use these process data

Michael B. Twidale; Paul F. Marty

2000-01-01

231

Team Creative Processes: The Importance of Complementary and Shared Mental Models  

Microsoft Academic Search

Past research suggests that knowledge diversity is utilized during creative processes, divergent and convergent thinking, to come up with novel and useful solutions. Whereas research examining the relationship between knowledge diversity and process outcomes has been mixed, differentiating knowledge into mental models may help explain team creative processes and outcomes. Herein, two types of mental models, complementary and shared mental

Deanna M. Kennedy

2011-01-01

232

The Geologic History of the Carbon Cycle  

NASA Astrophysics Data System (ADS)

Geologists, like other scientists, tend to view the global carbon cycle through the lens of their particular training and experience. The study of Earth's history requires a view both humbled by the knowledge of past global transformations and emboldened by the imagination of details not seen in the fragments of the rock record. In studying the past behavior of the carbon cycle, geologists are both amazed by unexpected discoveries and reassured by the extent to which "the present is the key to the past." Understanding the present-day carbon cycle has become a matter of societal urgency because of concerns about the effects of human activities on atmospheric chemistry and global climate. This public limelight has had far-reaching consequences for research on the geologic history of the carbon cycle as well as for studies of its present and future. The burgeoning new "interdiscipline" of biogeochemistry claims among its adherents many geologists as well as biologists, chemists, and other scientists. The pace of discovery demands that studies of the geologic history of the carbon cycle cannot be isolated from the context of present and future events.This chapter describes the behavior of the carbon cycle prior to human influence. It describes events and processes that extend back through geologic time and include the exchange of carbon between the Earth's surface and the long-term reservoirs in the lithosphere. Chapter 8.10 emphasizes carbon exchanges that are important over years to decades, with a focus on relatively recent human influences and prospects for change during the coming century. Chapter 4.03 presents an overview of the biogeochemistry of methane, again with emphasis on relatively recent events. In these chapters as well as in the present chapter, relationships between the carbon cycle and global climate are a central concern. Together, these chapters provide an overview of how our knowledge of the present-day carbon cycle can be applied both to contemporary issues and to the record of the past. Similarly, these chapters collectively reflect the collaborative efforts of biogeochemists to utilize information about past variations in the carbon cycle to understand both Earth's history and modern changes.This chapter begins with an overview of the carbon exchanges and processes that control the variations observed in the geologic record of the carbon cycle. Then examples of past carbon-cycle change are described, beginning with the most recent variations seen in cores drilled from glaciers and the sea floor, and concluding with the distant transformations inferred from the rock record of the Precambrian. Throughout this treatment, three themes are prominent. One is that different processes control carbon cycling over different timescales. A second theme is that relatively "abrupt" changes have played a central role in the evolution of the carbon cycle throughout Earth's history. The third theme is that the geologic cycling of carbon over all timescales passes through the atmosphere and the hydrosphere, and "it is this common course that unites the entire carbon cycle and allows even its most remote constituents to influence our environment and biosphere" (Des Marais, 2001).The description of geologic events in this chapter includes examples from a broad span of the geologic record, but does not distribute attention in proportion to the distribution of geologic time in Earth's history. Readers will note, in particular, a disproportional emphasis on the Quaternary period, the most recent but briefest of geologic periods. The reason for this emphasis is twofold. First, the quality of the available Quaternary record of carbon-cycle change is far better than that available for earlier geologic periods. Second, the Quaternary record reveals a particularly illuminating array of details about interactions among the atmosphere, the biosphere, and the hydrosphere - the subset of the carbon cycle that must be understood in order to comprehend carbon cycling over nearly all times and t

Sundquist, E. T.; Visser, K.

2003-12-01

233

Community Perceptions of Geologic Sequestration  

NASA Astrophysics Data System (ADS)

Political momentum for mitigating climate change through the use of large-scale energy technologies such as geologic sequestration is growing. This paper explores the views of communities living near an actual or potential geologic sequestration project site. Given the potential importance of geologic sequestration to U.S. energy policy, what might explain and influence the views of this technology by the community-members. Through focus groups and one-on-one interviews, we gathered the views of two communities in California's Central Valley. One community close to a Department of Energy sponsored geologic sequestration pilot-project and another similarly located community that is not actually a project site. Our analysis combined a review of the history of the communities with other technologies and their social and economic indicators with the results of the focus groups and interviews. The results suggest that the sense of community empowerment, as contextualized by the history of the community and socio-economic indicators, is an important indicator of positive views of geologic sequestration. In addition, the results indicate community members prefer to be informed about geologic sequestration from a variety of sources (e.g., academia and industry).

Wong-Parodi, G. M.; Farrell, A.; Ray, I.

2007-12-01

234

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

SciTech Connect

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

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

2007-10-23

235

The relative importance of hydrophobicity in determining runoff-infiltration processes in burned forest soils  

NASA Astrophysics Data System (ADS)

Wildfires induce fundamental changes to vegetation and soil structure/texture which conseqeuntly have major impacts on infiltration capacity, overland flow generation, runoff and sediment yields. The relative importance, however, of fire-induced soil water repellency (WR) on hydrological and erosional processes is somewhat controversial, partially, as the direct effects of soil WR in-situ field conditions have been difficult to isolate. It is generally accepted that hydrophobicity is caused by the formation of organic substances in forest soils, while burning is considered to enhance this process. Given the complex response of the soil-vegetation system to burning, soil WR is only one of several affecting soil hydrology. Other factors include the physical sealing of soils triggered by rain drops energy, the increase in soil erodibility due to changes in soil aggregates, and the role of the ash in sealing the burned surface. The degree and spatial distribution of WR burned varies considerably with fire severity, soil and vegetation type, soil moisture content and time since burning. Nevertheless, given the inverse relationship between soil moisture and hydrophobicity, the role of the latter in determining overland flow during wet winters when the soil is mostly inundated, is marginal. Following a 60 ha wildfire, which took place at the Pe'eram catchment during July 2009, we assessed the spatio-temporal distribution of WR in a burned Pinus halepensis forest. The site, located in the Upper Galille, Israel, was severely burned; the combustion removed all understory vegetation and burned down some of the trunks, leaving a thick layer of ash. The soils composed of reddish-brown clay loam forest soil and terra rossa on limestone bedrock, greyish light rendzina characterises the marl and chalk exposures. To consider the effect of distance from trees, in-situ hydrophobicity was assessed within a week, month and five months after the fire, using the WDPT test. Measurements were taken in concentric circles around the burned trees at two soil depths. We complemented this investigation by conducting a series of laboratory simulations. Non-burned soil was taken for laboratory analysis and rainfall simulations. Four treatment types were conducted: non-burned soil, non-burned soil + pine needles, burned soil without ash (300°C/15 min. after adding pine needles) and burned soil with the residue ash (300°C/15 min. after adding pine needles). Hydrophobicity was measured in all trays. Constant rainfall intensity of 30 mm/hr was simulated until terminal infiltration rates were reached. The experimental trays were oven dried and simulated again to imitate the effect of second rainstorm. Preliminary results indicate strong surface WR (60% >180s) at a distance of 1m and at the subsurface (50% >180s) directly by the trunk. In the control non-burned site stronger WR was found in proximity to the trunks. While in the burned sites extreme values (>300s) were apparent (15-35%) and correlated with distance from the trunk, no corresponding patterns were noticed in the control trees. The attempt to create homogeneous layer of WR under controlled laboratory conditions yielded a scattered pattern of repellency, similar to the field conditions. In contrast to expected, the bare soil and bare soil covered by needles exhibited the highest and lowest infiltration rates, respectively, while the burned hydrophobic soils demonstrated intermediate rates. It is thus suggested that in some soils, WR might enhance infiltration capacity by creating a complex mosaic of runoff-generating and runoff-absorbing micro-patches. In the experimental non-burned soil a rapid crusting of the surface provided lateral connectivity whilst the accumulation of litter and organic matter blanket the surface and enhance the vertical conductivity. To better understand the role of WR in generating hydrological response, it is required to consider the 3D 'sponge like' properties of the WR soils.

Wittenberg, Lea; Malkinson, Dan; Voogt, Annelies; Leska, Danny; Argaman, Eli; Keesstra, Saskia

2010-05-01

236

The role of importance and interest in the processing of text  

Microsoft Academic Search

In this review, text-based research on importance and interest is analyzed with several objectives in mind. First, the constructs of importance and interest are unidimensionally considered to show that various forms of each can operate within any text-learning environment. Second, research specifically addressing the interplay between these two factors is explored in relation to the goal of learning from text.

Patricia A. Alexander; Tamara L. Jetton

1996-01-01

237

Importance of Extracellular Enzymes for Biogeochemical Processes in Temporary River Sediments during Fluctuating Dry–Wet Conditions  

Microsoft Academic Search

\\u000a Climate change represents an emerging problem for temporary waters by increasing the frequency and duration of drought periods,\\u000a with potentially important effects on fluvial biogeochemical processes. Although benthic microbial processes have been recognized\\u000a to have a most important role in carbon, nutrient and energy flux, few studies have documented the response to dry–wet cycles\\u000a in temporary waters. Data so far

Annamaria Zoppini; Jürgen Marxsen

238

Geological processes and site structure: Assessing integrity at a Late Paleolithic open-air site in northern France  

Microsoft Academic Search

The difficulty of reading the archaeological record of caves and rock shelters is becoming increasingly obvious to Paleolithic researchers. Although some open-air sites are thought to avoid such taphonomic complications, interpreting their archaeological record is less straight- forward than assumed. Postdepositional processes may obscure structure in configurations of features and artifacts. Recently developed techniques for the excavation and analysis of

James G. Enloe

2006-01-01

239

Magellan stereo images and Venusian geology  

NASA Astrophysics Data System (ADS)

Areas of Venus imaged by Magellan radar with multiple viewing conditions provide unique data that will contribute to the solution of venusian geologic problems and provide a basis for quantitative comparison of venusian landforms with those on other planetary bodies. Three sets of images with different viewing conditions have been acquired: (1) left-looking with variable incidence angles (cycle 1 profile), (2) right-looking with nearly constant incidence angles (cycle 2 profile), and (3) left-looking with variable incidence angles that are almost always smaller than those in (1) (cycle 3 profiles). The unique data provided by paired images of the same scene with different incidence angles arises from image displacements caused by the relief of individual landforms at scales comparable to the ground-range and azimuth resolutions of the images. There are two aspects of the data: (1) Stereopsis achieved by simultaneous viewing of paired left-looking images of the same scene permits three-dimensional perception and interpretation of the morphologies of landforms at resolutions much finer than the altimetry footprints. (2) Measurements of differences of image displacements (parallax) on paired images with known imaging geometries provide quantitative estimates of the relief and shapes of landforms. The potential scientific contributions of the data can be grouped into two interrelated classes: (A) geologic mapping, analysis, and interpretation and (B) topical studies that involve topographic measurements. Stereopsis, without quantitative measurements, enhances geologic mapping, analysis, and interpretation of the rock units of Venus to a degree that cannot be overestimated. In geologic mapping, assemblages of landforms, assessments of backscatter and variations in backscatter, and fine-scale topography are used to define and characterize geologic map units that represent laterally continuous deposits or rock units. Stereopsis adds the important dimension of local relief for characterization of geologic units at a scale that is not possible with Magellan altimetry or products derived from the altimetry. Relative ages of the geologic units are determined using the well-known principles of superposition and intersection. Here, the perception of relief is invaluable because superposition relations among the geological units are more readily and clearly established. The recognition of folds, faults, and fault systems, regardless of their orientations, is facilitated with stereopsis so that sequences of deformation of the geologic units can be determined and structural analyses vastly improved. Shapes of landforms are readily perceived so that they can be properly interpreted. The end result of the mapping, analyses, and interpretations is a geologic history of Venus that includes the sequences of formation and deformation of various geologic units. Measurements of relief at the finest scale possible are necessary for numerous topical studies. Standard altimetry will provide the necessary information on the relief of most large landforms, but it tends to underestimate the relief of small landforms and distorts their shapes. Although special processing of the altimeter echoes improves the estimates of the relief and shapes of some landforms, there are uncertainties in the interpretations of the echoes. Examples of topical studies requiring measurements of relief are given.

Moore, H. J.; Saunders, R. S.; Plaut, Jeffrey J.; Parker, T. J.

1992-12-01

240

7 CFR 361.8 - Cleaning of imported seed and processing of certain Canadian-origin screenings.  

Code of Federal Regulations, 2010 CFR

...IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED...certain Canadian-origin screenings. (a) Imported...cleaning, a representative sample of the seed will be...technologist, an official seed laboratory, or by APHIS; if...business of processing screenings who wishes to...

2009-01-01

241

7 CFR 361.8 - Cleaning of imported seed and processing of certain Canadian-origin screenings.  

Code of Federal Regulations, 2010 CFR

...IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED...certain Canadian-origin screenings. (a) Imported...cleaning, a representative sample of the seed will be...technologist, an official seed laboratory, or by APHIS; if...business of processing screenings who wishes to...

2010-01-01

242

Process industry energy retrofits: the importance of emission baselines for greenhouse gas reductions  

Microsoft Academic Search

Fuel combustion for heat and\\/or electric power production is often the largest contributor of greenhouse gas (GHG) emissions from an industrial process plant. Economically feasible options to reduce these emissions include fuel switching and retrofitting the plant's energy system. Process integration methods and tools can be used to evaluate potential retrofit measures. For assessing the GHG emissions reduction potential for

Anders Ådahl; Simon Harvey; Thore Berntsson

2004-01-01

243

Extending Turnaround Process Research: Important Lessons From the U.S. Civil War  

Microsoft Academic Search

Although research has made progress in building our understanding of effective turnaround strategies, significant gaps remain in our knowledge about the strategic processes managers can employ to formulate and implement these strategies. Using a historical case of organizational turnaround employed by the U.S. government during the U.S. Civil War, the authors generate new insights into the turnaround process while confirming

Franz T. Lohrke; David Ahlstrom; Garry D. Bruton

2012-01-01

244

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

SciTech Connect

As part of the ongoing international code comparison project DECOVALEX, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near underground waste emplacement drifts. The simulations were conducted for two generic repository types with open or back-filled repository drifts under higher and lower post-closure temperature, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses are currently being resolved. Good agreement in the basic thermal-mechanical responses was achieved for both repository types, even with some teams using relatively simplified thermal-elastic heat-conduction models that neglect complex near-field thermal-hydrological processes. The good agreement between the complex and simplified (and well-known) process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level. The research teams have now moved on to the second phase of the project, the analysis of THM-induced permanent (irreversible) changes and the impact of those changes on the fluid flow field near an emplacement drift.

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

2006-02-01

245

History of Geology.  

ERIC Educational Resources Information Center

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

Greene, Mott T.

1985-01-01

246

Laboratory Studies of Homogeneous and Heterogeneous Chemical Processes of Importance in the Upper Atmosphere.  

National Technical Information Service (NTIS)

The objective of this study was to conduct measurements of chemical kinetics parameters for reactions of importance in the stratosphere and upper troposphere, and to study the interaction of trace gases with ice surfaces in order to elucidate the mechanis...

M. J. Molina

2003-01-01

247

Active interstitial remodeling: an important process in the hibernating human myocardium  

Microsoft Academic Search

ObjectivesThe purpose of this study is to investigate the morphologic characteristics of the cardiac interstitium in the hibernating human myocardium and evaluate whether active remodeling is present and is an important determinant of functional recovery.

Nikolaos G Frangogiannis; Sarah Shimoni; SuMin Chang; Guofeng Ren; Oliver Dewald; Christine Gersch; Kesavan Shan; Constandina Aggeli; Michael Reardon; George V Letsou; Rafael Espada; Mahesh Ramchandani; Mark L Entman; William A Zoghbi

2002-01-01

248

Tennessee Division of Geology  

NSDL National Science Digital Library

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

249

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

250

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

251

Local Meat and Poultry Processing: The Importance of Business Commitments for Long-Term Viability.  

National Technical Information Service (NTIS)

Consumer demand for local food, including local meat and poultry, has risen in recent years. To sell meat, farmers need access to appropriately scaled processing facilities with the skills, inspection status, and reliability to prepare these products safe...

A. Thiboumery L. Gwin R. Stillman

2013-01-01

252

The Importance of Research and Practice of Historical Photographic Processes in Photograph Conservation  

NASA Astrophysics Data System (ADS)

It is essential in photograph conservation to have an understanding of the processes used to make photographic materials for the proper identification, treatment, preservation and display of photographic images.

Osterman, Mark

253

Geodiversity: Exploration of 3D geological model space  

NASA Astrophysics Data System (ADS)

The process of building a 3D model necessitates the reconciliation of field observations, geophysical interpretation, geological data uncertainty and the prevailing tectonic evolution hypotheses and interpretations. Uncertainty is compounded when clustered data points collected at local scales are statistically upscaled to one or two points for use in regional models. Interpretation is required to interpolate between sparse field data points using ambiguous geophysical data in covered terranes. It becomes clear that multiple interpretations are possible during model construction. The various interpretations are considered as potential natural representatives, but pragmatism typically dictates that just a single interpretation is offered by the modelling process. Uncertainties are introduced into the 3D model during construction from a variety of sources and through data set optimisation that produces a single model. Practices such as these are likely to result in a model that does not adequately represent the target geology.A set of geometrical 'geodiversity' metrics are used to analyse a 3D model of the Gippsland Basin, southeastern Australia after perturbing geological input data via uncertainty simulation. The resulting sets of perturbed geological observations are used to calculate a suite of geological 3D models that display a range of geological architectures. The concept of biodiversity has been adapted for the geosciences to quantify geometric variability, or geodiversity, between models in order to understand the effect uncertainty has models geometry. Various geometrical relationships (depth, volume, contact surface area, curvature and geological complexity) are used to describe the range of possibilities exhibited throughout the model suite. End-member models geodiversity metrics are classified in a similar manner to taxonomic descriptions. Further analysis of the model suite is performed using principal component analysis (PCA) to determine important geometrical characteristics. The configuration of the model space is determined through identifying 'outlier' model examples, which potentially represent undiscovered model 'species'.

Lindsay, M. D.; Jessell, M. W.; Ailleres, L.; Perrouty, S.; de Kemp, E.; Betts, P. G.

2013-05-01

254

Maps out, models in at the British Geological Survey!  

NASA Astrophysics Data System (ADS)

BGS has stopped its' systematic onshore geological surveying programme and the litho-printing of geological maps will cease after a final batch of completed maps are published. In future BGS will undertake integrated mapping and 3D modelling in user defined target areas considering all our available geospatial data (map, boreholes, geophysics etc) assessed in a single 3D workspace. The output will be 3D geological framework models that capture the understanding and interpretation of the survey geologist and honour all available data at the time. As well as building new models in these strategic areas, BGS is collating all existing models assembled over the last 25 years into a common framework to produce a multi-scaled National Geological Model of Britain. comprising crustal, bedrock and quaternary and anthropocene themes (http://www.bgs.ac.uk/research/UKGeology/nationalgeologicalmodel/home.html). Different to the traditional geological map, the national model will not be completed at any specific scale, but at every point in the model there may be a different geological resolution available, depending on the purpose mof the original model or the strategic national need for subsurface information. The need for a complete and robust nested stratigraphic framework (BGS Lexicon) is becoming more important as we advance this model. Archive copies of all legacy models will be approved and stored in their native formats. In addition a newly designed Geological Object Store will hold geological objects such as coverages, surfaces and cross-sections from these models inside a relational database to ensure versioning and long-term security of the National Geological Model. In the mid-term these models will be attributed with physical properties such as porosity and density and form inputs to process models such as groundwater and landslide models to help predict and simulate environmental change. A key challenge for geologists and their systems building the geological models is to maintain their models in a dynamic manner, so that they are fit for the requirements of many different users and that feedback from external parties can be incorporated into them. Only then are we achieving our vision of a shared National Geological Model.

Mathers, Steve; Kessler, Holger

2013-04-01

255

Oklahoma Geological Survey  

NSDL National Science Digital Library

The Oklahoma Geological Survey is a state agency dedicated to geological research and public service. This site contains information on earthquakes, geographic names, general Oklahoma geology, and the mountains and water resources of the state. There are educational materials available to order, many of which are free. Geologic maps indicate rock types and ages, as well as the geologic provinces of the state. Links are provided for more resources.

256

Vermont Geological Survey  

NSDL National Science Digital Library

The Vermont Geological Survey, also known as the Division of Geology and Mineral Resources in the Department of Environmental Conservation, conducts surveys and research relating to the geology, mineral resources and topography of the State. This site provides details about the states geology with a downloadable state geologic map and key, state rock information, gold in Vermont, fossils found in the state, bedrock mapping details, stream geomorphology, the Champlain thrust fault, earthquakes, radioactive waste and links for additional information.

257

WIPP site and vicinity geological field trip  

SciTech Connect

The Environmental Evaluation Group is conducting an assessment of the radiological health risks to people from the Waste Isolation Pilot Plant. As a part of this work, EEG is making an effort to improve the understanding of those geological issues concerning the WIPP site which may affect the radiological consequences of the proposed repository. One of the important geological issues to be resolved is the timing and the nature of the dissolution processes which may have affected the WIPP site. EEG organized a two-day conference of geological scientists, on January 17-18, 1980. On the basis of the January conference and the June field trip, EEG has formed the following conclusions: (1) it has not been clearly established that the site or the surrounding area has been attacked by deep dissolution to render it unsuitable for the nuclear waste pilot repository; (2) the existence of an isolated breccia pipe at the site unaccompanied by a deep dissolution wedge, is a very remote possibility; (3) more specific information about the origin and the nature of the brine reservoirs is needed. An important question that should be resolved is whether each encounter with artesian brine represents a separate pocket or whether these occurrences are interconnected; (4) Anderson has postulated a major tectonic fault or a fracture system at the Basin margin along the San Simon Swale; (5) the area in the northern part of the WIPP site, identified from geophysical and bore hole data as the disturbed zone, should be further investigated to cleary understand the nature and significance of this structural anomaly; and (6) a major drawback encountered during the discussions of geological issues related to the WIPP site is the absence of published material that brings together all the known information related to a particular issue.

Chaturvedi, L.

1980-10-01

258

The importance of RpoS in the survival of bacteria through food processing  

Microsoft Academic Search

The resistance of bacteria to environmental stresses is recognised as an increasingly important area of microbiology. In particular, the alternative sigma factor RpoS has been shown to produce greater stress resistance in stationary phase cells of Salmonella and Escherichia coli compared with those in exponential phase. Our work has shown that RpoS can be induced in exponential phase in response

Christine E. R Dodd; Timothy G Aldsworth

2002-01-01

259

Five Important Lessons I Learned during the Process of Creating New Child Care Centers  

ERIC Educational Resources Information Center

In this article, the author describes her experiences of developing new child care sites and offers five important lessons that she learned through her experiences which helped her to create successful child care centers. These lessons include: (1) Finding an appropriate area and location; (2) Creating realistic financial projections based on real…

Whitehead, R. Ann

2005-01-01

260

Rehabilitation between institutional and non-institutional forensic psychiatric care: important influences on the transition process.  

PubMed

All patients cared for in forensic psychiatric care (FPC) have some kind of psychiatric disorder and most of them have committed one or more criminal acts. One part of the patient's rehabilitation is the transition from institutional to non-institutional FPC, but a number of patients do not succeed. The aim of this study was to elucidate different caregivers' experiences of aspects that influence the patients' ability to manage this rehabilitation. A qualitative approach was chosen. Data were collected by interviews in two focus groups, each group comprising of six caregivers representing both institutional and non-institutional FPC. The transcribed interviews were analysed using a qualitative content analysis. Important aspects influencing the patients' transition described were a well-planned care plan, together with a suitable non-institutional dwelling and a tailored occupation. Other important areas were having a well-functioning and trusting social network and a good relationship with a contact person/advocate. A major barrier to a successful transition was whether the patients managed their own finances or not. It was stated that it is important that the patients participate in the care and that different authorities create individual conditions and flexible solutions. All of these factors are important to focus on when caring for patients during their stay in the institutional FPC. PMID:22182281

Gustafsson, E; Holm, M; Flensner, G

2011-12-19

261

Geological pattern formation by growth and dissolution in aqueous systems  

SciTech Connect

Although many geological processes take place on time scales that are very long compared with the human experience, essentially all geological processes, fast or slow, are far from equilibrium processes. Surprisingly often, geological processes lead to the formation of quite simple and distinctive patterns, which hint at an underlying simplicity in many complex geological systems.. The ability to predict the seasons was critically important to early human society, and Halley’s prediction of the return of the comet that bears his name is still considered to be a scientific milestone. Spatial patterns have also attracted attention because of their aesthetic appeal, which depends in subtle ways on a combination of regularity and irregularity. In recent decades, rapid growth in the capabilities of digital computers has facilitated the simulation of pattern formation processes, and computer simulations have become an important tool for evaluating theoretical concepts and for scientific discovery. Computer technology in combination with other technologies such as high resolution digital cameras, scanning microprobes (atomic force microscopy AFM), confocal microscopy, and scanning tunneling microscopy (STM), for example) has facilitated the quantitative characterization of patterns over a wide range of scales and has enabled rapid advances in our ability to understand the links between large scale pattern formation and microscopic processes. The ability to quantitatively characterize patterns is important because it enables a more rigorous comparison between the predictions of computer models and real world patterns and their formation.In some cases, the idea that patterns with a high degree of regularity have simple origins appears to be justified, but in other cases, such as the formation of almost perfectly circular stone rings due to freeze-thaw cycles simple patterns appear to be the consequence of quite complex processes. In other cases, it has been shown that very simple non-linear processes can lead to extremely complicated patterns, and that some apparently complex disordered systems can be described quantitatively in terms of simple fractal models.

Paul Meakin

2010-03-01

262

Scatterometer Sensitivity for Statistical Process Control: Importance of Modeling for In-direct Measurements  

NASA Astrophysics Data System (ADS)

Scatterometer-based control in semiconductor processing requires careful thin-film model selection to obtain the best repeatability, reproducibility, linearity, and bias. A ``working'' standard based on process capability is used to gather data that is then re-matched with different models for comparison. This study provides a framework for model comparisons and examines the effects of the index of refraction and model complexity, or the number of trapezoids, on measurement system capability for control of a polysilicon gate etch process. Measurement capability for the gate profile is needed in addition to gate length. Results from a single-wavelength, multiple angle-of-incidence scatterometer are compared to reference data from atomic force and transmission electron microscopy. The polysilicon index of refraction has a strong effect on measurement scaling and repeatability. A counter-intuitive result is that a single-trapezoid model can perform better than a double-trapezoid model for linearity and bias.

Smith, Brian; Bushman, Scott; Baum, Chris

2005-09-01

263

Planetary geology  

Microsoft Academic Search

The solar system is considered along with the significance of meteorites as samples of the universe, the origin of planets, and earth's-eye view of the moon, previews of the lunar surface, aspects of impact cratering, lunar igneous processes, the mapping of the moon, the exploration of the moon in connection with the Apollo lunar landings, and the scientific payoff from

N. M. Short

1975-01-01

264

Fault isolation in semiconductor product, process, physical and package failure analysis: Importance and overview  

Microsoft Academic Search

Failure analysis plays a major role in all areas of the semiconductor company especially during product development cycle, 1st silicon stage, or in wafer processes and fabrication as well as assembly and package development. Different companies have different FA flows but all FA steps will need to start with fault isolation. Fault isolation is the step to narrow down the

Jiann Min Chin; Vinod Narang; Xiaole Zhao; Meng Yeow Tay; Angeline Phoa; Venkat Ravikumar; Lwin Hnin Ei; Soon Huat Lim; Chea Wei Teo; Syahirah Zulkifli; Mei Chyn Ong; Ming Chuan Tan

2011-01-01

265

Importance of deposition processes in simulating the seasonality of the Arctic black carbon aerosol  

Microsoft Academic Search

Anthropogenic aerosol components in the Arctic troposphere, such as black carbon (BC), show a strong seasonal variation characterized by a peak in later winter and early spring. The seasonality, however, is not properly simulated by most existing global aerosol models. Using the Canadian global air quality model with an online aerosol algorithm-Global Environmental Multiscale model with Air Quality processes (GEM-AQ),

L. Huang; S. L. Gong; C. Q. Jia; D. Lavoué

2010-01-01

266

Features are Also Important: Contributions of Featural and Configural Processing to Face Recognition  

Microsoft Academic Search

It has been suggested that face recognition is primarily based on configural information, with featural information playing little or no role. We investigated this idea by comparing the prototype effect for face prototypes that emphasized either featural or configural processing. In Experiment 1, participants showed a tendency to com- mit false alarms in response to nonstudied prototypes, and this ten-

Roberto Cabeza; Takashi Kato

2000-01-01

267

Photon production through multi-step processes important in nuclear resonance fluorescence experiments  

NASA Astrophysics Data System (ADS)

We present calculations describing the production of photons through multi-step processes occurring when a beam of gamma-rays interacts with a macroscopic material. These processes involve the creation of energetic electrons through Compton scattering, photo-absorption and pair production, the subsequent scattering of these electrons, and the creation of energetic photons occurring as these electrons are slowed through Bremsstrahlung emission. Unlike single Compton collisions, during which an energetic photon that is scattered through a large angle loses most of its energy, these multi-step processes result in a sizable flux of energetic photons traveling at large angles relative to an incident photon beam. These multi-step processes are also a key background in experiments that measure nuclear resonance fluorescence by shining photons on a thin foil and observing the spectrum of back-scattered photons. Effective cross sections describing the production of back-scattered photons are presented in a tabular form that allows simple estimates of backgrounds expected in a variety of experiments. Incident photons with energies between 0.5 MeV and 8 MeV are considered. These calculations of effective cross sections may be useful for those designing NRF experiments or systems that detect specific isotopes in well-shielded environments through observation of resonance fluorescence.

Hagmann, C.; Pruet, J.

2007-06-01

268

Photon Production through Multi-step Processes Important in Nuclear Fluorescence Experiments  

SciTech Connect

The authors present calculations describing the production of photons through multi-step processes occurring when a beam of gamma rays interacts with a macroscopic material. These processes involve the creation of energetic electrons through Compton scattering, photo-absorption and pair production, the subsequent scattering of these electrons, and the creation of energetic photons occurring as these electrons are slowed through Bremsstrahlung emission. Unlike single Compton collisions, during which an energetic photon that is scattered through a large angle loses most of its energy, these multi-step processes result in a sizable flux of energetic photons traveling at large angles relative to an incident photon beam. These multi-step processes are also a key background in experiments that measure nuclear resonance fluorescence by shining photons on a thin foil and observing the spectrum of back-scattered photons. Effective cross sections describing the production of backscattered photons are presented in a tabular form that allows simple estimates of backgrounds expected in a variety of experiments. Incident photons with energies between 0.5 MeV and 8 MeV are considered. These calculations of effective cross sections may be useful for those designing NRF experiments or systems that detect specific isotopes in well-shielded environments through observation of resonance fluorescence.

Hagmann, C; Pruet, J

2006-10-26

269

Important roles of multiphase process in enhancement mechanism of micro plastic particle combustion  

Microsoft Academic Search

Thermal recycling of recovered plastic resin has been investigated by supplying plastic resin powder as an additional fuel to the proposed twin-fuel industrial burner. The results emphasize the necessity of fundamental investigations, such as high-speed microscopic observations of micro plastic particles under abrupt heating. To observe the multiphase process of macro plastic particles under abrupt heating and to elucidate their

Norio Ohiwa; Yojiro Ishino; Atsunori Yamamoto

2009-01-01

270

Tenure: An Important Due Process Right or a Hindrance to Change in the Schools?  

ERIC Educational Resources Information Center

|Teacher tenure is a hotly contested concept in today's' school reform battles. Many discussions of tenure, however, use the term in incorrect ways that add little to the concepts that should be debated. Historically, tenure represents due process rights teachers acquire after several years of successful service. Other procedures, such as teacher…

Coleman, Julianne; Schroth, Stephen T.; Molinaro, Lisa; Green, Mark

2005-01-01

271

Flash photoelectrochemical studies of transient electrode processes important in solar-energy conversion  

Microsoft Academic Search

Electroanalytical and spectroscopic measurement techniques were applied to the study of transient photolytic, photoemissive, and photoelectrolytic processes associated with UV-visible irradiation of an electrode\\/solution interface. Both semiconductor and metallic electrodes were employed. For the characterization of transient phenomena, the general methodology of flash photolysis was employed (including both xenon flash lamp and tunable pulsed dye laser sources). The perspective afforded

S. P. Perone

1982-01-01

272

Flash photoelectrochemical studies of transient electrode processes important in solar-energy conversion. Final report  

Microsoft Academic Search

It has been the objective of this research program to apply electroanalytical and spectroscopic measurement techniques to the study of transient photolytic, photoemissive, and photoelectrolytic processes associated with uv-visible irradiation of an electrode\\/solution interface. Both semiconductor and metallic electrodes have been employed. For the characterization of transient phenomena, the general methodology of flash photolysis was employed (including both xenon flash

Perone

1982-01-01

273

Leaching the Poison--The Importance of Process and Partnership in Working with Yolngu  

ERIC Educational Resources Information Center

The popular construction of rural places as "white" spaces has significant repercussions for ethnic, Indigenous and "other" groups who do not always fit within prescribed dominant processes. This paper provides new insights for rural scholarship through an engagement with Indigenous specific experiences of governance and decision making in rural…

Marika, Rarriwuy; Yunupingu, Yalmay; Marika-Mununggiritj, Raymattja; Muller, Samantha

2009-01-01

274

Geologic Mapping of Mars  

NASA Astrophysics Data System (ADS)

Planetary geologic mapping involves integrating a terrestrial-based understanding of surface and subsurface processes and mapping principles to investigate scientific questions. Mars mappers must keep in mind that physical processes, such as wind and flowing water on Mars, are or were different from terrestrial processes because the planetary atmospheres have changed differently over time. Geologic mapping of Mars has traditionally been done by hand using overlays on photomosaics of Viking Orbiter and Mariner images. Photoclinometry and shadow measurements have been used to determine elevations, and the distribution and size of craters have been used to determine the relative ages of surfaces- more densely cratered surfaces are older. Some mappers are now using computer software (ranging from Photoshop to ArcInfo) to facilitate mapping, though their applications must be carefully executed so that registration of the images remains true. Images and some mapping results are now available on the internet, and new data from recent missions to Mars (Pathfinder and Surveyor) will offer clarifying information to mapping efforts. This paper consists chiefly of pictures and diagrams.

Price, Katherine H.

1998-05-01

275

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

276

Thermodynamic Properties of Magnesium Chloride Hydroxide Hydrate (Mg3Cl(OH)5:4H2O, Phase 5), and Its importance to Nuclear Waste Isolation in Geological Repositories in Salt Formations  

NASA Astrophysics Data System (ADS)

MgO (bulk, pure MgO corresponding to the mineral periclase) is the only engineered barrier certified by the Environmental Protection Agency for emplacement in the Waste Isolation Pilot Plant (WIPP) in the US, and an Mg(OH)2-based engineered barrier (bulk, pure Mg(OH)2 corresponding to brucite) is to be employed in the Asse repository in Germany. Both the WIPP and the Asse are located in salt formations. The WIPP is a U.S. Department of Energy geological repository being used for the permanent disposal of defense-related transuranic waste (TRU waste). The repository is 655 m below the surface, and is situated in the Salado Formation, a Permian salt bed mainly composed of halite, and of lesser amounts of polyhalite, anhydrite, gypsum, magnesite, clays and quartz. The WIPP Generic Weep Brine (GWB), a Na-Mg-Cl dominated brine, is associated with the Salado Formation. The previous vendor for MgO for the WIPP was Premier Chemicals and the current vendor is Martin Marietta Materials. Experimental studies of both Premier MgO and Martin Marietta MgO with the GWB at SNL indicate the formation of magnesium chloride hydroxide hydrate, Mg3Cl(OH)5:4H2O, termed as phase 5. However, this important phase is lacking in the existing thermodynamic database. In this study, the solubility constant of phase 5 is determined from a series of solubility experiments in MgCl2-NaCl solutions. The solubility constant at 25 oC for the following reaction, Mg3Cl(OH)5:4H2O + 5H+ = 3Mg2+ + 9H2O(l) + Cl- is recommended as 43.21±0.33 (2?) based on the Specific Interaction Theory (SIT) model for extrapolation to infinite dilution. The log K obtained via the Pitzer equations is identical to the above value within the quoted uncertainty. The Gibbs free energy and enthalpy of formation for phase 5 at 25 oC are derived as -3384±2 (2?) kJ mol-1 and -3896±6 (2?) kJ mol-1, respectively. The standard entropy and heat capacity of phase 5 at 25 oC are estimated as 393±20 J mol-1 K-1 and 374±19 J mol-1 K-1, respectively. Phase 5, and its similar phase, phase 3 (Mg2Cl(OH)3:4H2O), could have a significant role in influencing the geochemical conditions in geological repositories for nuclear waste in salt formations where MgO or brucite is employed as engineered barriers, when Na-Mg-Cl dominated brines react with MgO or brucite. Based on our solubility constant for phase 5 in combination with the literature value for phase 3, we predict that the composition for the invariant point of phase 5 and phase 3 would be mMg = 1.70 and pmH = 8.93 in the Mg-Cl binary system. The recent WIPP Compliance Recertification Application PA Baseline Calculations indicate that phase 5 instead of phase 3 is indeed a stable phase when GWB equilibrates with actinide-source-term phases, brucite, magnesium carbonates, halite and anhydrite. 1. This research is funded by WIPP programs administered by the U.S. Department of Energy. 2. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Xiong, Y.; Deng, H.; Nemer, M. B.; Johnsen, S.

2009-12-01

277

Experimental determination of the solubility constant for magnesium chloride hydroxide hydrate (Mg 3Cl(OH) 5·4H 2O, phase 5) at room temperature, and its importance to nuclear waste isolation in geological repositories in salt formations  

NASA Astrophysics Data System (ADS)

In this study, the solubility constant of magnesium chloride hydroxide hydrate, Mg 3Cl(OH) 5·4H 2O, termed as phase 5, is determined from a series of solubility experiments in MgCl 2-NaCl solutions. The solubility constant in logarithmic units at 25 °C for the following reaction, MgCl(OH)·4HO+5H=3Mg+9HO(l)+Cl is calculated as 43.21 ± 0.33 (2 ?) based on the specific interaction theory (SIT) model for extrapolation to infinite dilution. The Gibbs free energy and enthalpy of formation for phase 5 at 25 °C are derived as -3384 ± 2 (2 ?) kJ mol -1 and -3896 ± 6 (2 ?) kJ mol -1, respectively. MgO (bulk, pure MgO corresponding to the mineral periclase) is the only engineered barrier certified by the Environmental Protection Agency (EPA) for emplacement in the Waste Isolation Pilot Plant (WIPP) in the US, and an Mg(OH) 2-based engineered barrier (bulk, pure Mg(OH) 2 corresponding to brucite) is to be employed in the Asse repository in Germany. Phase 5, and its similar phase, phase 3 (Mg 2Cl(OH) 3·4H 2O), could have a significant role in influencing the geochemical conditions in geological repositories for nuclear waste in salt formations where MgO or brucite is employed as engineered barriers. Based on our solubility constant for phase 5 in combination with the literature value for phase 3, we predict that the composition for the invariant point of phase 5 and phase 3 would be mMg = 1.70 and pmH = 8.94 in the Mg-Cl binary system. The recent WIPP Compliance Recertification Application Performance Assessment Baseline Calculations indicate that phase 5, instead of phase 3, is indeed a stable phase when the WIPP Generic Weep Brine (GWB), a Na-Mg-Cl-dominated brine associated with the Salado Formation, equilibrates with actinide-source-term phases, brucite, magnesium carbonates, halite and anhydrite. Therefore, phase 5 is important to the WIPP, and potentially important to other repositories in salt formations.

Xiong, Yongliang; Deng, Haoran; Nemer, Martin; Johnsen, Shelly

2010-08-01

278

Predators temper the relative importance of stochastic processes in the assembly of prey metacommunities.  

PubMed

Communities assemble through a combination of stochastic processes, which can make environmentally similar communities divergent (high beta-diversity), and deterministic processes, which can make environmentally similar communities convergent (low beta-diversity). Top predators can influence both stochasticity (e.g. colonization and extinction events) and determinism (e.g. size of the realized species pool), in community assembly, and thus their net effect is unknown. We investigated how predatory fish influenced the scaling of prey diversity in ponds at local and regional spatial scales. While fish reduced both local and regional richness, their effects were markedly more intense at the regional scale. Underlying this result was that the presence of fish made localities within metacommunities more similar in their community composition (lower beta-diversity), suggesting that fish enhance the deterministic, relative to the stochastic, components of community assembly. Thus, the presence of predators can alter fundamental mechanisms of community assembly and the scaling of diversity within metacommunities. PMID:19723282

Chase, Jonathan M; Biro, Elizabeth G; Ryberg, Wade A; Smith, Kevin G

2009-08-31

279

Chemometrics: an important tool for the modern chemist, an example from wood-processing chemistry  

PubMed

This study briefly outlines the idea of principal component analysis and cross-correlation calculations (applied chemometrics) and presents an illustrative example from wood-processing chemistry. The applicability of chemometric data analysis was demonstrated by investigating the various structural changes that take place in dissolved and degraded lignin ("kraft lignin") during laboratory-scale kraft pulping of Scots pine (Pinus sylvestris) and silver birch (Betula pendula). The structural data (31P NMR and size exclusion chromatographic data) on kraft lignin were further processed by chemometric multivariate techniques (PCA and 2DCC), confirming, for example, that the cleavage of beta-aryl ether structures, the most prominent linkages between monomeric units, is directly related to the decrease in the average molecular mass of lignin. PMID:10761150

Malkavaara; Alen; Kolehmainen

2000-03-01

280

Nickel ferrite aerogels with monodisperse nanoscale building blocks--the importance of processing temperature and atmosphere.  

PubMed

Using two-step (air/argon) thermal processing, sol-gel-derived nickel-iron oxide aerogels are transformed into monodisperse, networked nanocrystalline magnetic oxides of NiFe(2)O(4) with particle diameters that can be ripened with increasing temperature under argon to 4.6, 6.4, and 8.8 nm. Processing in air alone yields poorly crystalline materials; heating in argon alone leads to single phase, but diversiform, polydisperse NiFe(2)O(4), which hampers interpretation of the magnetic properties of the nanoarchitectures. The two-step method yields an improved model system to study magnetic effects as a function of size on the nanoscale while maintaining the particles within the size regime of single domain magnets, as networked building blocks, not agglomerates, and without stabilizing ligands capping the surface. PMID:19206611

Pettigrew, Katherine A; Long, Jeffrey W; Carpenter, Everett E; Baker, Colin C; Lytle, Justin C; Chervin, Christopher N; Logan, Michael S; Stroud, Rhonda M; Rolison, Debra R

2008-04-01

281

Forming relationships in Australia: Qualitative insights into a process important to human wellbeing  

Microsoft Academic Search

Drawing on in-depth interviews conducted during 2002–03 for the Australian Family Formation Decisions (AFFD) Project, this\\u000a paper probes the relationship formation experiences of 115 women, men and couples of family-forming age living in eastern\\u000a Australia. Contemporary relationship formation is characterized by a mixture of ambivalence and resignation to having limited\\u000a control over the process on the one hand (if it

Gordon A. Carmichael; Andrea Whittaker

2007-01-01

282

The importance of a pleasant process of treatment: lessons on healing from South India.  

PubMed

This paper considers the significance of the positive and negative aesthetic qualities of different therapies--in other words, how "pleasant" (a term that is elaborated in the paper) it is to undergo various treatments. Interviews were conducted with patients undergoing three forms of healing for mental illness and related problems in the state of Kerala in southern India--ayurvedic (indigenous) psychiatry, allopathic (biomedical) psychiatry, and religious healing. Informants revealed concerns about the aesthetic process of therapy, reporting adverse reactions to allopathic treatments and in some cases asserting that they enjoyed ayurvedic procedures. Some informants with long-term illnesses had chosen to live in the process of therapy and reside indefinitely in the aesthetically engaging environment of a mosque, temple, or church after pursuing medical therapies for years. Thus considerations of the quality of the process of therapy also call for an examination of the limitations of the concept of "cure" for describing what is accomplished in healing in some therapeutic settings. PMID:12899466

Halliburton, Murphy

2003-06-01

283

Periods of active permafrost layer formation during the geological history of Mars: Implications for circum-polar and mid-latitude surface processes  

NASA Astrophysics Data System (ADS)

Permafrost is ground remaining frozen (temperatures are below the freezing point of water) for more than two consecutive years. An active layer in permafrost regions is defined as a near-surface layer that undergoes freeze-thaw cycles due to day-average surface and soil temperatures oscillating about the freezing point of water. A "dry" active layer may occur in parched soils without free water or ice but significant geomorphic change through cryoturbation is not produced in these environments. A wet active layer is currently absent on Mars. We use recent calculations on the astronomical forcing of climate change to assess the conditions under which an extensive active layer could form on Mars during past climate history. Our examination of insolation patterns and surface topography predicts that an active layer should form on Mars in the geological past at high latitudes as well as on pole-facing slopes at mid-latitudes during repetitive periods of high obliquity. We examine global high-resolution MOLA topography and geological features on Mars and find that a distinctive latitudinal zonality of the occurrence of steep slopes and an asymmetry of steep slopes at mid-latitudes can be attributed to the effect of active layer processes. We conclude that the formation of an active layer during periods of enhanced obliquity throughout the most recent period of the history of Mars (the Amazonian) has led to significant degradation of impact craters, rapidly decreasing the steep slopes characterizing pristine landforms. Our analysis suggests that an active layer has not been present on Mars in the last ˜5 Ma, and that conditions favoring the formation of an active layer were reached in only about 20% of the obliquity excursions between 5 and 10 Ma ago. Conditions favoring an active layer are not predicted to be common in the next 10 Ma. The much higher obliquity excursions predicted for the earlier Amazonian appear to be responsible for the significant reduction in magnitude of crater interior slopes observed at higher latitudes on Mars. The observed slope asymmetry at mid-latitudes suggests direct insolation control, and hence low atmospheric pressure, during the high obliquity periods throughout the Amazonian. We formulate predictions on the nature and distribution of candidate active layer features that could be revealed by higher resolution imaging data.

Kreslavsky, Mikhail A.; Head, James W.; Marchant, David R.

2008-02-01

284

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

285

Heat Conduction: An Important Process for the Shape of Iapetus's Dark Spots?  

NASA Astrophysics Data System (ADS)

The saturnian moon Iapetus is famous for its global black-and-white dichotomy. While its leading side (Cassini Regio) is covered by very dark material, the poles and trailing side are relatively bright. However, craters and troughs with dark floors are located within the bright area, especially at low latitudes. The boundaries of these smaller-scaled dark areas are very sharp. Even within the best-resolved images from the Cassini imaging experiment (ISS), the typical length of a drop-off in albedo is below the resolution limit. Thermal segregation, driven by a feedback process, has been proposed as the cause for the global dichotomy (Spencer and Denk 2010; Denk et al. 2010). In addition, for local features like craters and troughs, we explain the local darkening by an increased amount of insolation caused by the concave curvature of these features. We studied the insolation geometry using varying reflectance models. A model of linear interpolation between lunar and Lambert-like scattering reproduces the dark patterns relatively well. However, the increased insolation by itself neither explains the abundance of darkened terrain, nor the temporal behavior of darkening of fresh bright craters from the outside inward within the Cassini Regio area. A comparison of time scales and spatial scales shows that heat conduction might act as a major contributor to the growth of local dark areas within the bright terrain, despite its short range. Due to the repetitive nature of the processes needed for the growth of darkened terrain, the significant processes should not be as long-ranged as saltation of ice or CO2. We gratefully acknowledge funding of this work by the German Space Agency (DLR) Bonn through grant no. 50 OH 0305.

Galuba, Goetz; Denk, T.; Neukum, G.

2010-10-01

286

Importance of multi-mesonic fusion processes on (strange) antibaryon production  

NASA Astrophysics Data System (ADS)

Sufficiently fast chemical equilibration of (strange) antibaryons in an environment of nucleons, pions and kaons during the course of a relativistic heavy ion collision can be understood by a `clustering' of mesons to buildt up baryon-antibaryon pairs. This multi-mesonic (fusion-type) process has to exist in medium due to the principle of detailed balance. Novel numerical calculations for a dynamical setup are presented. They show that - at maximum SPS energies - yields of each antihyperon specie are obtained which are consistent with chemical saturated populations of T ~ 150 - 160 MeV, in line with popular chemical freeze-out parameters extracted from thermal model analyses.

Greiner, C.

2002-11-01

287

Competition between diffusion and fragmentation: an important evolutionary process of nature.  

PubMed

We investigate systems of nature where the common physical processes diffusion and fragmentation compete. We derive a rate equation for the size distribution of fragments. The equation leads to a third order differential equation which we solve exactly in terms of Bessel functions. The stationary state is a universal Bessel distribution described by one parameter, which fits perfectly experimental data from two very different systems of nature, namely, the distribution of ice-crystal sizes from the Greenland ice sheet and the length distribution of alpha helices in proteins. PMID:14754071

Ferkinghoff-Borg, Jesper; Jensen, Mogens H; Mathiesen, Joachim; Olesen, Poul; Sneppen, Kim

2003-12-23

288

The Importance of a Class of Secondary Relaxation Process in Glass-Forming Liquids  

NASA Astrophysics Data System (ADS)

Broadband dielectric spectroscopy was employed to study the relaxation dynamics of glass-forming isoeugenol. Above Tg, the dielectric spectra exhibit an excess wing on the high-frequency side of the primary ?-relaxation as well as an additional faster (?) process. As the temperature is lowered below Tg, the excess wing is transformed into a distinctly resolved ?-peak. Analysis of the spectra using the Coupling Model confirms that the ?-peak and its parent excess wing is the genuine Johari-Goldstein relaxation of isoeugenol.

Paluch, M.; Kaminska, E.; Kaminski, K.; Ngai, K. L.

2006-05-01

289

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

290

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

291

Sea-ice processes in the Laptev Sea and their importance for sediment export  

NASA Astrophysics Data System (ADS)

Based on remote-sensing data and an expedition during August-September 1993, the importance of the Laptev Sea as a source area for sediment-laden sea ice was studied. Ice-core analysis demonstrated the importance of dynamic ice-growth mechanisms as compared to the multi-year cover of the Arctic Basin. Ice-rafted sediment (IRS) was mostly associated with congealed frazil ice, although evidence for other entrainment mechanisms (anchor ice, entrainment into freshwater ice) was also found. Concentrations of suspended particulate matter (SPM) in patches of dirty ice averaged at 156 g m-3 (standard deviation ? = 140 g m-3 ), with a background concentration of 5 g m-3 The potential for sediment entrainment over the broad, shallow Laptev Sea shelf during fall freeze-up was studied through analysis of remote-sensing data and weatherstation records for the period 1979 1994. Freeze-up commences on 26 September (? = 7 d) and is completed after 19 days (? = 6 d). Meteorological conditions as well as ice extent prior to and during freeze-up vary considerably, the open-water area ranging between 107 × 103 and 447 × 103 km2. Ice motion and transport of IRS were derived from satellite imagery and drifting buoys for the period during and after the expedition (mean ice velocities of 0.04 and 0.05 m s-1, respectively). With a best-estimate sediment load of 16 t km-2 (ranging between 9 and 46 t km-2 ), sediment export from the eastern Laptev Sea amounts to 4 × 106 t yr-1, with extremes of 2 × 106 and 11 × 106 t yr-1. Implications for the sediment budget of the Laptev shelf, in particular with respect to riverine input of SPM, which may be of the same order of magnitude, are discussed.

Eicken, H.; Reimnitz, E.; Alexandrov, V.; Martin, T.; Kassens, H.; Viehoff, T.

1997-02-01

292

The Geology of Atlantis Basin, Mars, and Its Astrobiological Interest  

Microsoft Academic Search

Here is presented a general description of the Atlantis Basin geology, where the existence of different geological features seem to indicate the long-term presence of a thermal source and a water reservoir stable enaough to sustain biological processes.

M. A. de Pablo; A. G. Fairén; A. Márquez

2004-01-01

293

National Park Service: Tour of Park Geology  

NSDL National Science Digital Library

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

294

The development process and its relation to oil revenues and dependence on imported labor market in Saudi Arabia  

Microsoft Academic Search

This study describes and analyzes the process of development in Saudi Arabia in relation to oil revenues and Saudi Arabian dependence on imported foreign labor. Modern development and societal change in Saudi Arabia began with the commercial exploitation of oil in 1939, therefore Saudi economy must be viewed from a dual perspective: a highly capital-intensive oil sector and a labor-intensive

Almtairi

1991-01-01

295

Importance of perceptive adaptation of sound features in audio content processing  

NASA Astrophysics Data System (ADS)

The importance of perceptive modeling for calculation of sound features is well known. Use of simple perception-based adaptations of physically measured stimuli, such as the dB- scale or loudness, is a minimal requirement. Exactly how much value can be gained by more complex perceptive modeling, has not been investigated in detail. The paper examines this question for loudness measures, using well- known psychoacoustic knowledge for their calculation. Profiles of these measures are calculated on audio data of movie material, deliberately using 'natural' sound, instead of reverting to artificial sounds in the laboratory. Ultimately, the quality of a sound feature can only be judged by comparison to human estimates. Therefore, test people were asked to express their perception of loudness by continuous classification into five classes (called pp, p, mf, f, and ff). The results were used to evaluate two loudness measures: the sound pressure level, and an integral loudness measure, developed in the discussed research. The correlation of the human loudness estimates to the integral loudness measure, is about 10 percent higher than to the sound pressure level. In addition, the integral loudness results in a significantly better approximation of the curve of human loudness estimates.

Pfeiffer, Silvia

1998-12-01

296

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

297

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

298

Geologic Report for the Beaufort Sea Planning Area, Alaska: Regional Geology, Petroleum Geology, Environmental Geology.  

National Technical Information Service (NTIS)

The 192-page report provides a summary of the geologic framework, hydrocarbon potential, and physical environment of the offshore area tentatively scheduled for Federal OCS (Outer Continental Shelf) Oil and Gas Lease Sale 97. The geologic interpretation i...

J. D. Craig K. W. Sherwood P. P. Johnson

1985-01-01

299

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

300

The importance of laboratory water quality for studying initial bacterial adhesion during NF filtration processes.  

PubMed

Biofouling of nanofiltration (NF) and reverse osmosis (RO) membranes for water treatment has been the subject of increased research effort in recent years. A prerequisite for undertaking fundamental experimental investigation on NF and RO processes is a procedure called compaction. This involves an initial phase of clean water permeation at high pressures until a stable permeate flux is reached. However water quality used during the compaction process may vary from one laboratory to another. The aim of this study was to investigate the impact of laboratory water quality during compaction of NF membranes. A second objective was to investigate if the water quality used during compaction influences initial bacterial adhesion. Experiments were undertaken with NF 270 membranes at 15 bar for permeate volumes of 0.5 L, 2 L, and 5 L using MilliQ, deionized or tap water. Membrane autopsies were performed at each permeation point for membrane surface characterisation by contact angle measurements, profilometry, and scanning electron microscopy. The biological content of compacted membranes was assessed by direct epi-fluorescence observation following nucleic acid staining. The compacted membranes were also employed as substrata for monitoring the initial adhesion of Ps. fluorescens under dynamic flow conditions for 30 min at 5 min intervals. Compared to MilliQ water, membrane compaction using deionized and tap water led to decreases in permeate flux, increase in surface hydrophobicity and led to significant build-up of a homogeneous fouling layer composed of both living and dead organisms (>10(6) cells cm(-2)). Subsequent measurements of bacterial adhesion resulted in cell loadings of 0.2 × 10(5), 1.0 × 10(5) cells cm(-2) and 2.6 × 10(5) cells cm(-2) for deionized, tap water and MilliQ water, respectively. These differences in initial cell adhesion rates demonstrate that choice of laboratory water can significantly impact the results of bacterial adhesion on NF membranes. Standardized protocols are therefore needed for the fundamental studies of bacterial adhesion and biofouling formation on NF and RO membrane. This can be implemented by first employing pure water during all membrane compaction procedures and for the modelled feed solutions used in the experiment. PMID:23541307

Semião, A J C; Habimana, O; Cao, H; Heffernan, R; Safari, A; Casey, E

2013-03-21

301

Applications of imaging radar to geology  

Microsoft Academic Search

Tone, texture, and features imaged by radars were studied. A variety of computer image processing techniques were developed to reveal characteristics of these scences. Field checking of sites suggests links between the geology and the images. Tonal studies examine the effects of varying frequency polarization, and illumination geometry. Most surficial geologic units in Death Valley, California, are distinguishable by use

M. I. Daily

1985-01-01

302

Non-homologous end joining as an important mutagenic process in cell cycle-arrested cells  

PubMed Central

Resting cells experience mutations without apparent external mutagenic influences. Such DNA replication-independent mutations are suspected to be a consequence of processing of spontaneous DNA lesions. Using experimental systems based on reversions of frameshift alleles in Saccharomyces cerevisiae, we evaluated the impact of defects in DNA double-strand break (DSB) repair on the frequency of replication-independent mutations. The deletion of the genes coding for Ku70 or DNA ligase IV, which are both obligatory constituents of the non-homologous end joining (NHEJ) pathway, each resulted in a 50% reduction of replication-independent mutation frequency in haploid cells. Sequencing indicated that typical NHEJ-dependent reversion events are small deletions within mononucleotide repeats, with a remarkable resemblance to DNA polymerase slippage errors. Experiments with diploid and RAD52- or RAD54-deficient strains confirmed that among DSB repair pathways only NHEJ accounts for a considerable fraction of replication-independent frameshift mutations in haploid and diploid NHEJ non-repressed cells. Thus our results provide evidence that G0 cells with unrepressed NHEJ capacity pay for a large-scale chromosomal stability with an increased frequency of small-scale mutations, a finding of potential relevance for carcinogenesis.

Heidenreich, Erich; Novotny, Rene; Kneidinger, Bernd; Holzmann, Veronika; Wintersberger, Ulrike

2003-01-01

303

[The importance of circulating tumor cells in the diagnostic and therapeutic process in ovarian cancer].  

PubMed

Objective: Our goal was to summarize clinical studies which used CTC/CSCs for prognosis in patients with ovarian cancer.Type of study: Review article.Setting: Department of Gynecology and Obstetrics, 3rd Faculty of Medicine, Charles University, Faculty Hospital Královské Vinohrady, PragueMaterial and methods: This paper reviews various methods of CTCs detection as well as the biology and molecular characterisation of CTCs/CSCs.Conclusion: Determination of CTC (circulating tumor cells) / CSCS (cancer stem cells) has great potential in the diagnosis, prognosis, monitoring of disease, therapeutic effect and the risk of relapse in ovarian cancer for other malignancies. The presence of CTCs / CSCS in the blood seems to be a decisive factor in the initiation of metastatic process. The results of these studies show a clear link CTC negativity with an extension length of progression-free interval (PFI) and overall survival in patients with ovarian cancer. Keywords: circulating tumor cells - cancer stem cells - metastasis - ovarian cancer. PMID:24040981

Pavlásek, J; Ku?era, E

2013-08-01

304

Plasma wall interaction: Important ion induced surface processes and strategy of the EU Task Force  

NASA Astrophysics Data System (ADS)

In future thermo-nuclear fusion devices, such as ITER (International Thermonuclear Experimental Reactor), the interaction of the plasma with surrounding materials in the vacuum vessel constitutes one of the main remaining engineering problems. The choice of materials is a crucial point, which will determine issues such as the plasma facing components lifetime before refurbishment or the tritium inventory build up in the vessel, which should be limited for safety reasons. In order to tackle these issues, the European Task Force on Plasma Wall Interaction has been implemented in the frame of EFDA (European Fusion Agreement) in the fall 2002 with the aim “to provide ITER with information concerning lifetime-expectations of the divertor target plates and tritium inventory build-up rates in the foreseen starting configuration and to suggest improvements, including material changes, which could be implemented at an appropriate stage.” The EU-PWI-TF brings together the efforts of 24 European associations in the following fields of investigation:Material erosion and transport in tokamaks.Tritium inventory and removal.Transient heat loads on plasma facing components.Dust production and removal.Associated modelling and diagnostic development. This paper will present the organisation of the EU-PWI-TF. It will provide examples for the multitude of surface processes in Plasma Wall Interaction and present the status of knowledge concerning material erosion and hydrogen retention for the choice of ITER materials (Beryllium, Carbon and Tungsten).

Roth, Joachim; Tsitrone, Emmanuelle; Loarte, Alberto

2007-05-01

305

Tissue-specific differences of the mitochondrial protein import machinery: in vitro import, processing and degradation of the pre-F1? subunit of the ATP synthase in spinach leaf and root mitochondria  

Microsoft Academic Search

In this study we report the first comparison of the mitochondrial protein import and processing events in two different tissues from the same organism. Both spinach leaf and root mitochondria were able to import and process the in vitro transcribed and translated Neurospora crassa F1ß subunit of ATP synthase to the mature size product. Temperature optimum for protein import, 20

Carina Knorpp; Marie Hugosson; Sara Sjöling; AnnaCarin Eriksson; Elzbieta Glaser

1994-01-01

306

Chemical Processes in Protoplanetary Disks. II. On the Importance of Photochemistry and X-Ray Ionization  

NASA Astrophysics Data System (ADS)

We investigate the impact of photochemistry and X-ray ionization on the molecular composition of, and ionization fraction in, a protoplanetary disk surrounding a typical T Tauri star. We use a sophisticated physical model, which includes a robust treatment of the radiative transfer of UV and X-ray radiation, and calculate the time-dependent chemical structure using a comprehensive chemical network. In previous work, we approximated the photochemistry and X-ray ionization; here, we recalculate the photoreaction rates using the explicit UV wavelength spectrum and wavelength-dependent reaction cross sections. We recalculate the X-ray ionization rate using our explicit elemental composition and X-ray energy spectrum. We find that photochemistry has a larger influence on the molecular composition than X-ray ionization. Observable molecules sensitive to the photorates include OH, HCO+, N2H+, H2O, CO2, and CH3OH. The only molecule significantly affected by the X-ray ionization is N2H+, indicating that it is safe to adopt existing approximations of the X-ray ionization rate in typical T Tauri star-disk systems. The recalculation of the photorates increases the abundances of neutral molecules in the outer disk, highlighting the importance of taking into account the shape of the UV spectrum in protoplanetary disks. A recalculation of the photoreaction rates also affects the gas-phase chemistry due to the adjustment of the H/H2 and C+/C ratios. The disk ionization fraction is not significantly affected by the methods adopted to calculate the photochemistry and X-ray ionization. We determine that there is a probable "dead zone" where accretion is suppressed, present in a layer, Z/R <~ 0.1-0.2, in the disk midplane, within R ? 200 AU.

Walsh, Catherine; Nomura, Hideko; Millar, T. J.; Aikawa, Yuri

2012-03-01

307

Louisiana Geological Survey  

NSDL National Science Digital Library

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

308

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.

309

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.

310

Teaching Sedimentary Geology  

NSDL National Science Digital Library

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

311

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

312

Brines in Crustal Processes: Important Roles Inferred From Experimental Studies (Invited)  

NASA Astrophysics Data System (ADS)

Concentrated salt solutions are increasingly implicated as active agents in many fluid-mediated deep- and mid-crust processes, including rock-melting, charnockitic alteration, trace-element depletion and enrichment, regional metasomatism including dehydration and rehydration, albitization, deep-crustal oxidation, and formation of economic mineral deposits. Unique properties of saline aqueous fluids at high P and T, recently revealed by experimental work, provide new explanations for these metasomatic features and encourage further search for a brine connection in other outstanding problems of metamorphism. Specific properties of high P-T NaCl solutions favorable for deep-crustal metasomatism are high solubility for some rock-forming components, especially CaO and FeO, even at high salt concentration, very low H2O activity as a consequence of pressure-induced dissociation, allowing compatibility with anhydrous (granulite facies) mineral assemblages, and high ability to infiltrate mineral grain boundaries. The high affinity of alkali chloride brines for CaO can explain trace element mobility in high grade metamorphism, by virtue of the high solubility of apatite, and the puzzling phenomenon of subsolidus charnockitic alteration, as in South India, in which orthopyroxene is formed from the incongruent dissolution of calcic amphibole. The great pressure effect on lowering H2O activity in concentrated pore-fluid brines causes fluid-present melting points of crustal rocks to swerve sharply to higher temperatures with increasing depth, in contrast to the behavior in the presence of pure H2O. This fact could account for the formation of swarms of granite intrusions in shear-zone-related settings, such as the Caledonide granites of Scotland and northern Ireland. It is postulated that salty solutions of deep-seated origin inhibit melting as they rise through the lower crust, but induce large-scale melting at mid-crust levels because of increase of H2O activity by release of pressure. Sulfide ore deposits of various kinds including the porphyry Cu-Mo ores can be explained by the action of CaSO4-bearing brines of magmatic origin. The changes in composition of Cl-rich fluids in contact with feldspathic rocks with falling temperature could explain regional albitization in the lower grade portions of the great Precambrian metamorphic belts such as the Limpopo Belt of South Africa. Of the several possible sources of concentrated salty fluids, the most appealing for wide application is effluents from volatile-rich basaltic intrusions, which also provide heat for regional metamorphism and temperature gradients convenient for geochemical segregation and ore mineral accumulation.

Newton, R. C.; Manning, C. E.

2009-12-01

313

Geology of Kilauea volcano  

SciTech Connect

This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.

Moore, R.B. (Geological Survey, Denver, CO (United States). Federal Center); Trusdell, F.A. (Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory)

1993-08-01

314

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

USGS Publications Warehouse

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

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

2005-01-01

315

Sequences of the iron-sulfur protein precursor necessary for its import and two-step processing in yeast mitochondria.  

PubMed

Gene fusion techniques were used to examine whether the presequence of the iron-sulfur protein contains sufficient information for the import of attached mouse cytosolic enzyme dihydrofolate reductase into isolated yeast mitochondria and its subsequent two-step processing. Genes encoding amino-terminal segments of the iron-sulfur precursor protein including the proposed first presequence (residues 1-21), the complete presequence (residues 1-30), and various lengths of the precursor protein from 31 to 160 residues were fused, in frame, to dihydrofolate reductase. All of the fusion proteins, after synthesis in an in vitro transcription-translation system, were imported into a protease-resistant compartment of mitochondria where a single proteolytic cleavage was observed at the first processing site. The second cleavage, however, was not observed after import of any of the chimeric proteins, suggesting that the second cleavage may be strongly influenced by the presence of the passenger protein. A deletion mutant of the iron-sulfur protein precursor lacking residues 161-180 underwent two proteolytic cleavages similar to those observed for the wild-type iron-sulfur protein after import into mitochondria. These results suggest that the complete sequence of the mature form of the iron-sulfur protein including the amino acid residues involved in binding the iron sulfur clusters is not necessary for the second cleavage to occur. In addition, the hydrophobic sequence present in residues 55-66 of the precursor protein which has been suggested to anchor the iron-sulfur protein to the inner membrane, was not necessary for the import and two-step processing of the protein, since a deletion mutant lacking residues 55-66 was processed correctly. PMID:8037454

Japa, S; Beattie, D S

1994-08-01

316

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.

2011-03-30

317

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.

318

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.

319

Research on 3D Geological Modeling by Using GOCAD Software  

Microsoft Academic Search

This paper presents technical issues on use and analysis of one kind of 3D geological modeling software named GOCAD. As the conventional geological information is not sufficient to meet the requirements of the current engineering construction, 3D geological modeling needs to be constructed. Otherwise, the key techniques are quite important to 3D modeling in engineering construction formation when using GOCAD.

Li Yongcheng; Shen Naiqi; Li Biao; Yan Yan; Dong Mei

2010-01-01

320

Petroleum geological activities in West Greenland in 2001  

Microsoft Academic Search

Greenland petroleum geological activities at the Geological Survey of Denmark and Greenland (GEUS) during 2001 were focused mainly on the preparation of the 2002 licensing round offshore West Greenland. Promotion of the exploration opportunities in the licensing round area between 63° and 68°N has played an important role together with launching of new seismic and geological pro- jects. Critical evaluation

Flemming G. Christiansen; Jørgen A. Bojesen-Koefoed; James A. Chalmers; Finn Dalhoff; Tove Nielsen; Henrik Nøhr-Hansen; Martin Sønderholm

321

Status report on the geology of the Oak Ridge Reservation  

Microsoft Academic Search

This report provides an introduction to the present state of knowledge of the geology of the Oak Ridge Reservation (ORR) and a cursory introduction to the hydrogeology. An important element of this work is the construction of a modern detailed geologic map of the ORR (Plate 1), which remains in progress. An understanding of the geologic framework of the ORR

R. D. Jr. Hatcher; P. J. Lemiszki; J. L. Foreman; R. B. Dreier; R. H. Ketelle; R. R. Lee; Suk Young Lee; D. A. Lietzke; W. M. McMaster

1992-01-01

322

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

323

Geology of National Parks  

USGS Publications Warehouse

This is a set of two sheets of 3D images showing geologic features of many National Parks. Red-and-cyan viewing glasses are need to see the three-dimensional effect. A search on the World Wide Web will yield many sites about anaglyphs and where to get 3D glasses. Red-blue glasses will do but red-cyan glasses are a little better. This publication features a photo quiz game: Name that park! where you can explore, interpret, and identify selected park landscapes. Can you identify landscape features in the images? Can you explain processes that may have helped form the landscape features? You can get the answers online.

Stoffer, Philip W.

2008-01-01

324

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

325

Geological features indicative of processes related to the hematite formation in Meridiani Planum and Aram Chaos, Mars: a comparison with diagenetic hematite deposits in southern Utah, USA  

Microsoft Academic Search

In order to understand the formation of the few but large, hematite deposits on Mars, comparisons are often made with terrestrial hematite occurrences. In southern Utah, hematite concretions have formed within continental sandstones and are exposed as extensive weathered-out beds. The hematite deposits are linked to geological and geomorphological features such as knobs, buttes, bleached beds, fractures and rings. These

Jens Ormö; Goro Komatsu; Marjorie A. Chan; Brenda Beitler; William T. Parry

2004-01-01

326

Geologic Measurements using Rover Images: Lessons from Pathfinder with Application to Mars 2001  

NASA Astrophysics Data System (ADS)

The Pathfinder Sojourner rover successfully acquired images that provided important and exciting information on the geology of Mars. This included the documentation of rock textures, barchan dunes, soil crusts, wind tails, and ventifacts. It is expected that the Marie Curie rover cameras will also successfully return important information on landing site geology. Critical to a proper analysis of these images will be a rigorous determination of rover location and orientation. Here, the methods that were used to compute rover position for Sojourner image analysis are reviewed. Based on this experience, specific recommendations are made that should improve this process on the '01 mission.

Bridges, N. T.; Haldemann, A. F. C.; Herkenhoff, K. E.

1999-01-01

327

Louisiana Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Louisiana Geological Survey (LGS). The site includes general information about LGS and its various offices, as well as an overview of the Basin Research Energy Section, the oil, gas, and coal research section of LGS. The publications and data page features a catalog and ordering information for documents on mineral resources, fossils, water resources, geological bulletins and maps, and many others, as well as a selection of downloadable maps, including 30 x 60 minute geologic quadrangles, a generalized geologic map of the state with accompanying text, and an online map viewer of the state with selectable layers (geology, water bodies, cultural features, and Landsat imagery). There is also an online listing of well logs, grouped by parish, online listings of core samples, grouped by state, and downloadable public information documents on a variety of geologic topics.

328

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

329

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

330

Pennsylvania Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Pennsylvania Geological Survey. Users can access digital maps, data, and Geographic Information Systems (GIS), information on economic resources, and information on field mapping in the state. Classroom resources include a set of lesson plans on Pennsylvania geology; 'Rock Boxes', a set of rock samples which can be ordered; information on mineral collecting; and a series of educational publications, page-sized maps, and the 'Trail of Geology' park guide.

2011-03-29

331

The Geology of Virginia  

NSDL National Science Digital Library

From the College of William of Mary Department of Geology comes the Geology of Virginia Web site. From the Appalachian Plateau to the coastal plain, visitors can explore the geology and physical characteristics of the diverse landscape of the commonwealth of Virginia through simple descriptions and well designed graphics. Even if you don't live in the area, the site does a good job of capturing the interest of anyone looking for quality material on the presented subjects.

1997-01-01

332

Practical petroleum geology  

SciTech Connect

This book contains the following eight chapters: Basic Concepts of Geology; Sedimentation; Oil and Gas Accumulation; Exploration; Economics; Well Sitting; Field Development; and Past, Present and Future. The goal of the book is to present a description of the field of petroleum geology that is centered on the point of view of the practicing petroleum geologist. After the beginning three chapters of pure geology, slanted toward the petroleum geologist's interest in oil and gas, the discussion turns toward more active concerns.

Leecraft, J.

1985-01-01

333

Icelandic Geology Resources  

NSDL National Science Digital Library

The main feature of this site from Hamrahlio College of Reykjavik, Iceland is an interactive geological map of Iceland showing lava flows and glaciers. Other highlights include links to related Icelandic geology pages (e.g., The Effect of Diatom Mining, Iceland's Ministry of the Environment), news sources and journals, and Icelandic geological societies (not all are in English). A recommended resource for glaciologists, volcanologists, and educators in earth science.

Douglas, Georg R.

334

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

335

Using the Choquet integral for screening geological CO2 storage sites  

Microsoft Academic Search

For geological COâ storage site selection, it is desirable to reduce the number of candidate sites through a screening process before detailed site characterization is performed. Screening generally involves defining a number of criteria which then need to be evaluated for each site. The importance of each criterion to the final evaluation will generally be different. Weights reflecting the relative

Zhang

2011-01-01

336

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

PubMed

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

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

2010-11-01

337

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

PubMed Central

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

Ak?n, Cigdem; Bilgin, C. Can; Beerli, Peter; Westaway, Rob; Ohst, Torsten; Litvinchuk, Spartak N.; Uzzell, Thomas; Bilgin, Metin; Hotz, Hansjurg; Guex, Gaston-Denis; Plotner, Jorg

2010-01-01

338

Arizona Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Arizona Geological Survey. Information accessible here includes maps, information on oil, gas, and minerals in the state, back issues of the survey's newsletter, and a list of resources for public education in the state. These resources include information centers for Arizona geology and Earth Science, the survey's geology library and bibliographic database, a repository of rock cuttings and cores, and a contact for earth science education who will assist teacher groups in introducing local geology to their classes.

339

Understanding Geologic Maps  

NSDL National Science Digital Library

This is an exercise in which students are reintroduced to geologic maps and encouraged to "deconstruct" the map into constituent elements in order to understand the geologic history of the area. The preceding lectures in the course have recapitulated material that the students have covered in Introduction to Physical Geology. During class, the students work through the maps that were part of lab exercises in the Intro level course, so that basic concepts are recalled (superposition, cross-cutting relationships, basic faults and folds). The final product is a geologic history of this map area.

Burberry, Cara

340

Modeling Geologic Time  

NSDL National Science Digital Library

In this activity students convert major events in Earth history from years before present into scale distances. After a list of events and their scale distances have been formulated, students construct a geologic time scale on 5 meters of adding machine paper, beginning with the formation of the Earth. Students will investigate change through geologic time; design, construct and interpret a model of geologic time; relate major events in Earth history to the geologic time scale; and compare and relate the span of Earth history to events of historical time and of the human lifetime. Some sample events and their approximate relative ages are included.

Firebaugh, James

341

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

342

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

343

Geologic repositories for radioactive waste: the nuclear regulatory commission geologic comments on the environmental assessment  

Microsoft Academic Search

The NRC staff completed its review of the Environmental Assessments (EAs) issued by the Department of Energy (DOE) in December, 1984, in support of the site selection processes established by the Nuclear Waste Policy Act of 1982 (NWPA). The EAs contain geologic information on nine sites that DOE has identified as potentially acceptable for the first geologic repository in accordance

P. S. Justus; J. S. Trapp; K. B. Westbrook; R. Lee; M. B. Blackford; B. Rice

1985-01-01

344

Femtosecond spectroscopy of bacterial photosynthesis{emdash}towards an understanding of the most important energy conversion process on earth  

SciTech Connect

Reaction centers of bacterial photosynthesis are ideal systems to study photosynthetic energy conversion. Femtosecond spectroscopy has delivered extensive information on the molecular mechanisms of the primary electron transfer. The data show, that primary electron transfer is an ultrafast stepwise reaction, where the electron is transferred via closely spaced pigments with reaction times as fast as 0.9 ps and 3.5 ps. Experiments on mutated and modified reaction centers allow to determine the energetics of the various intermediates in the reaction center. Recently, femtosecond experiments with light pulses in the mid infrared have shown, that an additional fast process occurs on the 200 fs timescale in the initially excited special pair. Only afterwards the well established electron transfer reactions take place. This fast process may be of importance for the optimization of the primary reaction. {copyright} {ital 1996 American Institute of Physics.}

Zinth, W.; Hamm, P.; Arlt, T.; Wachtveitl, J. [Ludwig Maximilians Universitaet Muenchen, Institut fuer Medizinische Optik, Barbarastr.1 6, 80797 Muenchen (Germany)

1996-04-01

345

Femtosecond spectroscopy of bacterial photosynthesis--towards an understanding of the most important energy conversion process on earth  

SciTech Connect

Reaction centers of bacterial photosynthesis are ideal systems to study photosynthetic energy conversion. Femtosecond spectroscopy has delivered extensive information on the molecular mechanisms of the primary electron transfer. The data show, that primary electron transfer is an ultrafast stepwise reaction, where the electron is transferred via closely spaced pigments with reaction times as fast as 0.9 ps and 3.5 ps. Experiments on mutated and modified reaction centers allow to determine the energetics of the various intermediates in the reaction center. Recently, femtosecond experiments with light pulses in the mid infrared have shown, that an additional fast process occurs on the 200 fs timescale in the initially excited special pair. Only afterwards the well established electron transfer reactions take place. This fast process may be of importance for the optimization of the primary reaction.

Zinth, W.; Hamm, P.; Arlt, T.; Wachtveitl, J. [Ludwig Maximilians Universitaet Muenchen, Institut fuer Medizinische Optik, Barbarastr.1 6, 80797 Muenchen (Germany) (Germany)

1996-04-01

346

In vitro import of cytochrome c peroxidase into the intermembrane space: release of the processed form by intact mitochondria.  

PubMed

Cytochrome c peroxidase (CCP) is a nuclearly encoded hemoprotein located in the intermembrane space (IMS) of Saccharomyces cerevisiae mitochondria. Wild-type preCCP synthesized in rabbit reticulocyte lysates, however, was inefficiently translocated into isolated mitochondria and was inherently resistant to externally added proteases. To test whether premature heme addition to the apoprecursor was responsible for the protease resistance and the inability to import preCCP, site-directed mutagenesis was used to replace the axial heme ligand (His175) involved in forming a pseudo-covalent link between the heme iron and CCP. Mutant proteins containing Leu, Arg, Met, or Pro at residue 175 of mature CCP were sensitive to proteolysis and were imported into isolated mitochondria as judged by proteolytic processing of the precursor. The inhibition of wild-type CCP translocation across the outer membrane may result from the inability of the heme-containing protein to unfold during the translocation process. Although the protease responsible for cleaving preCCP to its mature form is believed to be located in the IMS, most of the processed CCP was located in the supernatant rather than the mitochondrial pellet. Since the outer membranes were shown to be intact, the anomalous localization indicated that preCCP may not have been completely translocated into the IMS before proteolytic processing or that conformationally labile proteins may not be retained by the outer membrane. Proteolytic maturation of preCCP also occurred in the presence of valinomycin, suggesting that the precursor may be completely or partially translocated across the outer mitochondrial membrane independent of a potential across the inner mitochondrial membrane. PMID:2545724

Kaput, J; Brandriss, M C; Prussak-Wieckowska, T

1989-07-01

347

Geology in coal resource utilization  

SciTech Connect

The 37 papers in this book were compiled with an overriding theme in mind: to provide the coal industry with a comprehensive source of information on how geology and geologic concepts can be applied to the many facets of coal resource location, extraction, and utilization. The chapters have been arranged to address the major coal geology subfields of Exploration and Reserve Definition, Reserve Estimation, Coalbed Methane, Underground Coal Gasification, Mining, Coal Quality Concerns, and Environmental Impacts, with papers distributed on the basis of their primary emphasis. To help guide one through the collection, the author has included prefaces at the beginning of each chapter. They are intended as a brief lead-in to the subject of the chapter and an acknowledgement of the papers' connections to the subject and contributions to the chapter. In addition, a brief cross-reference section has been included in each preface to help one find papers of interest in other chapters. The subfields of coal geology are intimately intertwined, and investigations in one area may impact problems in another area. Some subfields tend to blur at their edges, such as with reserve definition and reserve estimation. Papers have been processed separately for inclusion on the data base.

Peters, D.C. (ed.)

1991-01-01

348

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

349

The role of slab detachment processes in the opening of the western–central Mediterranean basins: some geological and geophysical evidence  

Microsoft Academic Search

A review of the geological and geophysical data from the central and western Mediterranean region and the present-day upper mantle structure derived from tomographic studies are utilized in order to define the Oligocene–Recent geodynamic evolution for the area. In line with previous work, we suggest that the Miocene–Quaternary opening of the western and central Mediterranean basins is the result of

E. Carminati; M. J. R Wortel; W. Spakman; R. Sabadini

1998-01-01

350

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

Microsoft Academic Search

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

Marilena Moroni; Vicente A. Girardi; Alfredo Ferrario

2001-01-01

351

Carbon dioxide reaction processes in a model brine aquifer at 200 °C and 200 bars: implications for geologic sequestration of carbon  

Microsoft Academic Search

The reactive behavior of supercritical CO2 under conditions relevant to geologic storage and sequestration of C is largely unknown. Experiments were conducted in a flexible cell hydrothermal apparatus to determine the extent of fluid–rock reactions, in addition to carbonate mineral precipitation, that may occur in a brine aquifer–aquitard system that simulates a saline aquifer storage scenario. The system was held

John P. Kaszuba; David R. Janecky; Marjorie G. Snow

2003-01-01

352

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

353

Geological analyses of the surface of Venus and Mars from lander spacecraft images and orbital radar observations  

Microsoft Academic Search

The association of observed local scale geologic structures with basic processes such as basaltic volcanism, and the extrapolation of larger regional scales in order to assess the relative importance of such processes on Venus and Mars is studied. The data considered are of two types: lander spacecraft digital images with centimeter resolution, and orbital radar measurements averaged over 30 to

J. B. Garvin

1984-01-01

354

James Hutton: The Founder of Modern Geology  

NSDL National Science Digital Library

This article reports on the life and influence of James Hutton, considered the founder of modern geology. It covers the existing thinking about Earth's creation, how Hutton's scientific training and his work as a farmer came together in his pursuit of geology, his important contributions to the new science of geology, and the influence his work had on future generations of scientists. The article explains why the boundary between the two rock types at Siccar Point in Scotland is now called the Hutton Unconformity and defines his key concept, the Theory of Uniformitarianism.

355

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

356

The importance of vocal affect to bimodal processing of emotion: implications for individuals with traumatic brain injury.  

PubMed

Persons with traumatic brain injury (TBI) often have difficulty recognizing emotion in others. This is likely due to difficulties in interpreting non-verbal cues of affect. Although deficits in interpreting facial cues of affect are being widely explored, interpretation of vocal cues of affect has received much less attention. Accurate interpretation of vocal affect cues is important, particularly when facial cues are absent or ambiguous. These cues also contribute to more accurate identification of emotion. The neural substrates of facial and vocal affect recognition appear to be shared, further contributing to improved bimodal processing. This article discusses the importance of vocal affect cues in interpreting emotion. Expression of vocal affect in persons with TBI is also briefly discussed since difficulty in controlling and manipulating vocal cues of emotion when speaking may also contribute to poor social outcomes. A review of the literature in acoustic parameters that contribute to identification and expression of emotions is followed by a discussion on the integration of visual and auditory cues in bimodal processing and the relationship between facial and vocal affect in persons with TBI. Learning Outcomes: Readers will be able to: 1) Identify the parameters primarily used to describe the acoustic characteristics of vocal affect; 2) Describe the acoustic parameters typically associated with Anger, Fear, Happiness and Sadness; 3) Describe the difficulties experienced by persons with TBI in the perception and integration of facial and vocal cues of affect. PMID:18692197

Zupan, Barbra; Neumann, Dawn; Babbage, Duncan R; Willer, Barry

2008-07-09

357

Geology of California. Second Edition  

Microsoft Academic Search

Two introductory chapters familiarize readers with basic geologic concepts. The following chapters describe the geology of each of California's 11 geomorphic provinces; the San Andreas fault and offshore geology are discussed in two separate chapters. Four appendices acquaint readers with technical words and terms, common minerals and rocks in California, geologic time, and geologic theories that pertain to California. During

R. M. Norris; R. W. Webb

1990-01-01

358

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

359

SOPAC marine geology atlases  

Microsoft Academic Search

The US Geological Survey conducted a series of marine geologic and geophysical cruises in the southwest Pacific Ocean in 1982 and 1984 as part of a program with participation by Australia and New Zealand. These two SOPAC expeditions obtained various data, which have been compiled into a series of charts and thematic products for the offshore areas of Tonga, Fiji,

T. E. Chase; B. A. Seekins; J. D. Young; J. A. Wahler

1986-01-01

360

Geological hydrogen storage  

Microsoft Academic Search

The probably least expensive form of hydrogen storage would be geological storage in formations easy to excavate, such as salt dome intrusions near the surface (which can be excavated by water flushing) or vertically curved, capped aquifer layers not requiring excavation at all. Such geological formation are already in use for natural gas storage and have proven very stable. Consideration

Bent Sørensen

361

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

362

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

363

Forensic geology exhumed  

Microsoft Academic Search

Forensic geology binds applied geology to the world of legal controversy and action. However, the term ``forensic'' is often misconstrued. Although even some attorneys apply it only to the marshalling of evidence in criminal cases, it has a much broader definition. One dictionary defines it as ``pertaining to, connected with, or used in courts of law or public discussion and

Joseph Didier Martinez

1991-01-01

364

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

365

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.

366

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

367

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.

368

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

369

LOMONOSOV AND MODERN GEOLOGY  

Microsoft Academic Search

The tribute to Mikhail V. Lomonosov on the occasion of his 250th anniversary of his birth enables better students of the history of geological science to identify the obvious confusion and glaring flaws in this overstated presentation of Lomonosov as the father of geology. Perhaps it will stimulate interest in Lomonosov's On Terrestrial Strata, published in 1763. The article contains

V. Ye Khain

1963-01-01

370

Wyoming State Geological Survey  

NSDL National Science Digital Library

This agency's mission is to study, examine, and seek an understanding of the geology, mineral resources, and physical features of the State; to prepare, publish, and distribute reports and maps of Wyoming's geology, mineral resources, and physical features; and to provide information, advice, and services related to the geology, mineral resources, and physical features of the State. This site contains details and reports about metals in Wyoming, earthquakes and other hazards, coal, industrial minerals, uranium, oil and gas. The field trip section contains details about various areas to visit with students and gives a general geologic description. There is also a searchable bibliography with publications about Wyoming geology. Links are provided for additional resources.

371

Verification of imported food upon import for radiation processing: Dried herbs, including herbs used in food supplements, and spices by PSL and TL  

NASA Astrophysics Data System (ADS)

The Italian National Institute of Health in 2005-2006 performed an analytical survey of import on dried spices and herbs, including herbs used in food supplements, to investigate the entry in Italy of irradiated, and not correctly labelled, raw materials. In this survey, 52 samples, including nine herbal extracts, were collected. The method of photo-stimulated luminescence (PSL) was applied to all samples and only samples screened positive or intermediate with PSL were analysed by using the thermo-luminescence (TL) method. Out of the 12 samples screened positive or intermediate with PSL, the TL method confirmed irradiation of five samples (10% of the total assayed samples). One out of these five samples was a herbal supplement whereas three were herbal extracts that are known to be used as ingredients of herbal supplements, and another one was a spice.

Boniglia, C.; Aureli, P.; Bortolin, E.; Onori, S.

2009-07-01

372

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

373

Origins of Sinuous and Braided Channels on Ascraeus Mons, Mars — A Keck Geology Consortium Undergraduate Research Project  

NASA Astrophysics Data System (ADS)

This Keck Geology Consortium project, involving four undergrad geology students, mapped and analyzed sinuous channel features on Ascraeus Mons, Mars, to better understand the role of volcanic and fluvial processes in the geological evolution of Mars.

de Wet, A. P.; Bleacher, J. E.; Garry, W. B.

2012-03-01

374

OneGeology-Europe: architecture, portal and web services to provide a European geological map  

NASA Astrophysics Data System (ADS)

OneGeology-Europe is a large ambitious project to make geological spatial data further known and accessible. The OneGeology-Europe project develops an integrated system of data to create and make accessible for the first time through the internet the geological map of the whole of Europe. The architecture implemented by the project is web services oriented, based on the OGC standards: the geological map is not a centralized database but is composed by several web services, each of them hosted by a European country involved in the project. Since geological data are elaborated differently from country to country, they are difficult to share. OneGeology-Europe, while providing more detailed and complete information, will foster even beyond the geological community an easier exchange of data within Europe and globally. This implies an important work regarding the harmonization of the data, both model and the content. OneGeology-Europe is characterised by the high technological capacity of the EU Member States, and has the final goal to achieve the harmonisation of European geological survey data according to common standards. As a direct consequence Europe will make a further step in terms of innovation and information dissemination, continuing to play a world leading role in the development of geosciences information. The scope of the common harmonized data model was defined primarily by the requirements of the geological map of Europe, but in addition users were consulted and the requirements of both INSPIRE and ‘high-resolution' geological maps were considered. The data model is based on GeoSciML, developed since 2006 by a group of Geological Surveys. The data providers involved in the project implemented a new component that allows the web services to deliver the geological map expressed into GeoSciML. In order to capture the information describing the geological units of the map of Europe the scope of the data model needs to include lithology; age; genesis and metamorphic character. For high resolution maps physical properties, bedding characteristics and weathering also need to be added. Furthermore, Geological data held by national geological surveys is generally described in national language of the country. The project has to deal with the multilingual issue, an important requirement of the INSPIRE directive. The project provides a list of harmonized vocabularies, a set of web services to deal with them, and a web site for helping the geoscientists while mapping the terms used into the national datasets into these vocabularies. The web services provided by each data provider, with the particular component that allows them to deliver the harmonised data model and to handle the multilingualism, are the first part of the architecture. The project also implements a web portal that provides several functionalities. Thanks to the common data model implemented by each web service delivering a part of the geological map, and using OGC SLD standards, the client offers the following option. A user can request for a sub-selection of the map, for instance searching on a particular attribute such as "age is quaternary", and display only the parts of the map according to the filter. Using the web services on the common vocabularies, the data displayed are translated. The project started September 2008 for two years, with 29 partners from 20 countries (20 partners are Geological Surveys). The budget is 3.25 M€, with a European Commission contribution of 2.6 M€. The paper will describe the technical solutions to implement OneGeology-Europe components: the profile of the common data model to exchange geological data, the web services to view and access geological data; and a geoportal to provide the user with a user-friendly way to discover, view and access geological data.

Tellez-Arenas, Agnès.; Serrano, Jean-Jacques; Tertre, François; Laxton, John

2010-05-01

375

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

376

Potential of Microbes to Increase Geologic CO2 Storage Security  

NASA Astrophysics Data System (ADS)

Geologic Carbon Capture and Storage (CCS) involves the injection of supercritical CO2 into underground formations such as brine aquifers where microbe-rock-fluid interactions will occur. These interactions may be important for the long-term fate of the injected CO2. Concepts and results will be presented from bench to meso-scale experiments focusing on the utility of attached microorganisms and biofilms to enhance storage security of injected CO2, via mineral-trapping, solubility trapping, formation trapping, and leakage reduction. Batch and flow experiments at atmospheric and geologic CO2 storage-relevant pressures have demonstrated the ability of microbial biofilms to decrease the permeability of natural and artificial porous media, survive the exposure to scCO2, and facilitate the conversion of CO2 into long-term stable carbonate phases as well as increase the solubility of CO2 in brines. Recent work has focused on small and large scale (75 cm diameter, 38 cm high sandstone) radial flow systems as well as the molecular characterization and isolation of microbes from geologic carbon sequestration-relevant environments. Methods for microscopic and macroscopic visualization of relevant processes from the pore to the bulk scale are being developed and have been proven to be essential tools in establishing the necessary understanding to increase CO2 storage security. As a result, reactive transport models describing the influence of biological processes on CO2 storage security have been developed and are continuously being modified to include relevant processes.

Gerlach, R.; Mitchell, A. C.; Ebigbo, A.; Phillips, A.; Cunningham, A. B.

2011-12-01

377

Geologic mapping of northern Lunae Planun, Mars  

NASA Astrophysics Data System (ADS)

Lunae Planum is an elevated region east of the Tharsis rise, and ridged plains containing numerous Sacra Dorsa wrinkle ridges, cross-cutting Sacra Fossae grabens, and lobate scarps compose this Martian Plateau. Geologic mapping of the northern Lunae Planum region was undertaken to better understand to emplacement history of the ridge plains, the structural history of deformation, and the periods of fluvial processes that have modified the region. These investigations are important for several reasons: (1) the history of plains emplacement yields information valuable for understanding the evolution of Tharsis volcanism; (2) interpretation of structural deformation has implications on the lithology of the Martian crust; and (3) determining the history and fate of Martian volatiles is dependent upon knowing the periods of outflow activity. A discussion of the findings is presented.

Craddock, Robert A.; Maxwell, Ted A.

1991-06-01

378

Volcanic and geologic database projects of the Geological Survey of Japan (Invited)  

NASA Astrophysics Data System (ADS)

Geological Survey of Japan (GSJ) is presently implementing the GEO-DB project, which aims to integrate all kinds of geological information in GSJ. GSJ published more than 50 CD-ROM series and established more than 20 databases at the Research Information Database (RIO-DB) of the National Institute of Advanced Industrial Science and Technology (AIST). Presently, four volcanic databases are open to the public: (1) Quaternary volcano database (RIO-DB), (2) Active volcano database (RIO-DB), and (3) ASTER satellite image database of major volcanoes. The Quaternary volcano database contains information such as volcanic type, history, age and pictures of more than 300 Quaternary volcanoes in Japan. More detailed volcanic information will be added to the database in the near future. The active volcano database contains information of active volcanoes in Japan such as the catalog of eruptive events during the last 10,000 years and geological maps of active volcanoes. The ASTER satellite image database provides sequential ASTER satellite image datasets of major volcanoes in the world. Collaboration between Quaternary and active volcano databases and the VOGRIPA project is the next important activity at the Geological Survey of Japan. The Geological Survey of Japan introduced the Integrated Geological Map Database (GeoMapDB) in 2006. The GeoMapDB is based on a WebGIS technology, which makes it possible to browse, overlay and search geological maps online. The database contains geological maps with scales ranging from 1:2 million to 1:25,000. Links to aforementioned volcanic database and active fault database in RIO-DB are also available. OneGeology is an international initiative of the geological surveys of the world and a flagship project of the ‘International Year of Planet Earth’. It aims to create dynamic geological map of the world available at the world wide web. Geological Surveys from 109 countries of the world are participating in this project. The Geological Survey of Japan, AIST is promoting OneGeology in Asia. The OneGeology portal was officially launched in 2008. Volcanic hazard maps are available for most major active volcanoes in Japan. A web-based GIS system combining various types of information with real time numerical simulations are very important for the next generation of volcanic hazard maps. Volcanic gravity flow simulations using the energy cone model were developed on GEO Grid system in AIST. An interactive user interface is available on the GEO Grid website. The pyroclastic flow simulation is open to all scientists and local government officials at http://geoapp.geogrid.org/gridsphere.

Takarada, S.; Nakano, S.; Hoshizumi, H.; Itoh, J.; Urai, M.; Nishiki, K.

2009-12-01

379

Generalizing geological maps with the GeoScaler software: The case study approach  

NASA Astrophysics Data System (ADS)

Map generalization is rapidly becoming an important task in surficial and bedrock geology as broader regional and cross-boundary compilations are made from maps originally describing more specific areas. However, the entire process is still not defined in sufficient detail and relatively few automated tools are available. Moreover, the existing tools are primarily designed for generalization of topographic maps and do not address the needs specific to geology. Here we present two case studies describing our approach to the generalization of surficial and bedrock geology maps, respectively. To accomplish the task, we employed the GeoScaler software developed at the Laboratoire de cartographie numérique et de photogrammétrie (LCNP) of the Quebec division of the Geological Survey of Canada (Version 2009). The software is free over the Internet but requires an ArcGIS (ArcInfo) license. Four surficial geology maps at 1:250,000 scale were produced from 14 maps scaled at 1:100,000, while a single compilation of six bedrock maps was generalized from 1:125,000 to 1:500,000 scale. We describe the general considerations required to approach any generalization exercise, applied software, objectives, input data, major generalization steps, and the final results. All generalized maps were favorably evaluated by experts in geological mapping and the surficial maps have been published.

Smirnoff, Alex; Huot-Vézina, Gabriel; Paradis, Serge J.; Boivin, Ruth

2012-03-01

380

PREMIER: a proposed mission to observe processes controlling atmospheric composition in the height range most important to climate  

NASA Astrophysics Data System (ADS)

The PREMIER (PRocess Exploration through Measurements of Infrared and millimetre-wave Emitted Radiation) mission is one of three candidates for ESA's 7th Earth Explorer Core Mission (due for launch in 2016) that have been approved for Phase A study. The mission proposes to make detailed measurements in the mid/upper troposphere and lower stratosphere in order to quantify processes controlling atmospheric global composition in this height range of particular importance to climate. PREMIER would consist of an infrared limb imaging spectrometer which would observe 3D fields of trace gases, alongside a millimetre-wave limb sounder which would enable observations in the presence of most cirrus clouds, and also provide complementary trace gases. In addition, co-located data from EPS-MetOp would be combined with that from PREMIER, to extend the scientific impact of PREMIER down into the lower troposphere, to explore links to surface emissions and pollution. In this presentation, simulations of its capabilities will be described together with some preliminary results from airborne precursors

Kerridge, Brian; Orphal, Johannes; van Weele, Michiel; Murtagh, Donal; McConnell, Jack; Hegglin, Michaela; Peuch, Vincent-Henri; Reise, Martin

2010-05-01

381

The importance of aerosol composition and mixing state on predicted CCN concentration and the variation of the importance with atmospheric processing of aerosol  

SciTech Connect

The influences of atmospheric aerosols on cloud properties (i.e., aerosol indirect effects) strongly depend on the aerosol CCN concentrations, which can be effectively predicted from detailed aerosol size distribution, mixing state, and chemical composition using Köhler theory. However, atmospheric aerosols are complex and heterogeneous mixtures of a large number of species that cannot be individually simulated in global or regional models due to computational constraints. Furthermore, the thermodynamic properties or even the molecular identities of many organic species present in ambient aerosols are often not known to predict their cloud-activation behavior using Köhler theory. As a result, simplified presentations of aerosol composition and mixing state are necessary for large-scale models. In this study, aerosol microphysics, CCN concentrations, and chemical composition measured at the T0 urban super-site in Mexico City during MILAGRO are analyzed. During the campaign in March 2006, aerosol size distribution and composition often showed strong diurnal variation as a result of both primary emissions and aging of aerosols through coagulation and local photochemical production of secondary aerosol species. The submicron aerosol composition was ~1/2 organic species. Closure analysis is first carried out by comparing CCN concentrations calculated from the measured aerosol size distribution, mixing state, and chemical composition using extended Köhler theory to concurrent CCN measurements at five supersaturations ranging from 0.11% to 0.35%. The closure agreement and its diurnal variation are studied. CCN concentrations are also derived using various simplifications of the measured aerosol mixing state and chemical composition. The biases associated with these simplifications are compared for different supersaturations, and the variation of the biases is examined as a function of aerosol age. The results show that the simplification of internally mixed, size-independent particle composition leads to substantial overestimation of CCN concentration for freshly emitted aerosols in early morning, but can reasonably predict the CCN concentration after the aerosols underwent atmospheric processing for several hours. This analysis employing various simplifications provides insights into the essential information of particle chemical composition that needs to be represented in models to adequately predict CCN concentration and cloud microphysics.

Wang, J.; Cubison, M.; Aiken, A.; Jimenez, J.; Collins, D.; Gaffney, J.; Marley, N.

2010-03-15

382

Indiana Geological Survey  

NSDL National Science Digital Library

This is the homepage of the Indiana Geological Survey (IGS). Site materials include information on Earth science issues such as groundwater, mapping, coal and mineral resources, oil and gas, and seismic hazards. There is also information on the geologic time scale and stratigraphic record, rocks and minerals, fossils (including nautiloids of the Ordovician period in Indiana), caves and karst topography in Indiana, and glacial geology. The Geographic Information Ssytems (GIS) and mapping section includes a GIS atlas for the state, an online map viewer, links to the Indiana coal mine information system, petroleum database management system, and a download page where users can access GIS datasets for the state.

383

Journal of Geology  

NSDL National Science Digital Library

From the University of Chicago Press's Journals Division, the Journal of Geology is currently available online free of charge (note: subscription fees may soon apply, but no initiation date is provided). This first-rate technical journal, which publishes "research and theory in geophysics, geochemistry, sedimentology, geomorphology, petrology, plate tectonics, volcanology, structural geology, mineralogy, and planetary sciences" has been in print form since 1893. All of the 1999 issues of the Journal of Geology electronic edition are available here. Internet users can access full-text articles with internal links to references and figures (html, .pdf. .ps).

384

Formation evaluation: Geological procedures  

SciTech Connect

This volume goes beyond a discussion of petroleum geology and the techniques of hydrocarbon (oil and gas) logging as a reservoir evaluation tool. It provides the logging geologist with a review of geological techniques and classification systems that will ensure the maximum development of communicable geological information. Contents include: 1. Introduction--cuttings recovery, cutting sampling, core sampling, rock classification; 2. Detrital rocks--classification, description; 3. Carbonate rocks--classification, description; 4. Chemical rocks-introduction, siliceous rocks, ferruginous rocks, aluminous rocks, phosphatic rocks, aluminous rocks, carbonaceous rocks; 5. Igneous and metamorpbic rocks; Appendix; References and Index.

Whittaker, A.

1985-01-01

385

What is Geologic Time?  

NSDL National Science Digital Library

This webpage of the National Park Service (NPS) and United States Geological Survey (USGS) discusses geologic time and what it represents. Beginning about 4.6 billion years ago and ending in the present day, this site exhibits (to scale) the various eras, periods, eons, and epochs of Earth's history with a downloadable geologic time scale available. Links provide maps of what the Earth looked like at various times in its history, as well as a description of how scientists developed the time scale and how they know the age of the Earth.

386

Geology of Earth's Moon  

NSDL National Science Digital Library

First, researchers at the University of California, San Diego discuss the importance of studying earthquakes on the moon, also known as moonquakes, and the Apollo Lunar Seismic Experiment (1). Users can discover the problems scientists must deal with when collecting the moon's seismic data. The students at Case Western Reserve University created the second website to address three missions the Institute of Space and Astronautical Science (ISAS) has planned between now and 2010, including a mission to the moon (2). Visitors can learn about the Lunar-A probe that will be used to photograph the surface of the moon, "monitor moonquakes, measure temperature, and study the internal structure." Next, the Planetary Data Service (PDS) at the USGS offers users four datasets that they can use to create an image of a chosen area of the moon (3). Each dataset can be viewed as a basic clickable map; a clickable map where users can specify size, resolution, and projection; or an advanced version where visitors can select areas by center latitude and longitude. The fourth site, produced by Robert Wickman at the University of North Dakota, presents a map of the volcanoes on the moon and compares their characteristics with those on earth (4). Students can learn how the gravitational forces on the Moon affect the lava flows. Next, Professor Jeff Ryan at the University of South Florida at Tampa supplies fantastic images and descriptive text of the lunar rocks obtained by the Apollo missions (5). Visitors can find links to images of meteorites, terrestrial rocks, and Apollo landings as well. At the Science Channel website, students and educators can find a video clip discussing the geologic studies on the moon along with videos about planets (6). Users can learn about how studying moon rocks help scientists better understand the formation of the earth. Next, the Smithsonian National Air and Space Museum presents its research of "lunar topography, cratering and impacts basins, tectonics, lava flows, and regolith properties" (7). Visitors can find summaries of the characteristics of the moon and the main findings since the 1950s. Lastly, the USGS Astrogeology Research Program provides archived lunar images and data collected between 1965 and 1992 by Apollo, Lunar Orbiter, Galileo, and Zond 8 missions (8). While the data is a little old, students and educators can still find valuable materials about the moon's topography, chemical composition, and geology.

387

Using Digital Databases to Create Geologic Maps for the 21st Century: A GIS Model for Geologic, Environmental, Cultural and Transportation Data from Southern Rhode Island.  

National Technical Information Service (NTIS)

Knowledge of surface and subsurface geology is fundamental to the planning and development of new or modified transportation systems. Toward this end, we have compiled a model GIS database consisting of important geologic, cartographic, environmental, and...

O. D. Hermes A. I. Veeger N. Hamidzada D. P. Murray

2002-01-01

388

Web Geologic Time Scale  

NSDL National Science Digital Library

The University of California-Berkeley Museum of Paleontology (last mentioned in the June 16, 1995 Scout Report) has recently updated its Web Geologic Time Scale, an online feature that helps users learn about the geologic timeline and explore related museum exhibits. The familiar geologic timeline appears on the main page of the Web site, with hypertext links for each division of time. Every page of the Web Geologic Time Machine site is liberally sprinkled with links to related UCMP Web pages; think of it as a portal to all online information available from the museum. Altogether, this Web site provides a well-organized and comprehensive resource for learning how the planet has changed over time, and would be a great addition to earth or life sciences classroom material for a broad range of grades.

1994-01-01

389

Comprehending Geologic Time  

NSDL National Science Digital Library

This online calculator helps students understand the classic analogy of relating the geologic time scale to a yard stick. It will help reinforce the concept of the briefness of human history relative to the age of the Earth.

390

Interactive Geologic Timeline Activity  

NSDL National Science Digital Library

In this learning activity, students use a web-based geologic timeline to examine temperature, CO2 concentration, and ice cover data to investigate how climate has changed during the last 715 million years.

University, Environmental L.

391

Geologic Puzzles: Morrison Formation  

NSDL National Science Digital Library

Images of faulted strata, tilted turbidites, and beach rocks bring the field into the classroom, giving students practice in doing what geoscientists do. These images are examples of geologic puzzles.

Macdonald, Heather

392

Economic Geology (Oil & Gas)  

ERIC Educational Resources Information Center

|Briefly reviews the worldwide developments in petroleum geology in 1971, including exploration, new fields, and oil production. This report is condensed from the October Bulletin of the American Association of Petroleum Geologists. (PR)|

Geotimes, 1972

1972-01-01

393

Curating Geological Collections.  

National Technical Information Service (NTIS)

ONR funding was used to accomplish the long-term goals of the Scripps Institution of Oceanography Geological Collections, which have been and continue to be, to serve the scientific community by acquisition, maintenance, conservation and curation of marin...

J. W. Hawkins A. Sanfilippo

2004-01-01

394

Geology in the field  

SciTech Connect

This book is an entirely new one-volume text and reference that covers the procedures essential to geologic field studies. It presents information not found in other field geology texts, including identification and modern classification of rocks, means of recognizing and interpreting primary structures in rocks (which reveal their origin), coverage of engineering geologic maps, and recognition of recently active faults. The procedures are described thoroughly enough so that students can proceed largely on their own. It follows the typical sequence of a student's experience in learning field work-starting with the first observation of an outcrop and proceeding to methods of measurement and mapping, ending with preparation of a full geologic report.

Compton, R.R.

1985-01-01

395

Photos of structural geology  

NSDL National Science Digital Library

This page contains four categories of structural geology photos: brittle structures, ductile structures, active tectonics, and unconformities. All photos are freely downloadable and are at resolutions sufficient for power point.

Miller, Marli

396

North Dakota Geological Survey  

NSDL National Science Digital Library

This is the homepage of the North Dakota Geological Survey. Site materials include information on the state's oil, gas and coal resources, maps, publications, and regulations. The paleontology page features educational articles, information on fossil collecting, articles about fossil exhibits, and information on the state fossil collection. The state GIS hub creates and distributes digital spatial data that conforms to national mapping standards. The teaching tools page includes illustrations and descriptions of rocks and minerals found in the state, as well as information on meteorites and newsletter articles about teaching North Dakota geology. There are also links to landslide maps, surficial geology maps, and links to other survey publications such as reports, bulletins, field studies, other geological and topographic maps, and information on groundwater resources.

397

USGS Geologic Hazards  

NSDL National Science Digital Library

The Geologic Hazards section of the US Geological Survey (USGS) conducts research into the causes of geological phenomena such as landslides and earthquakes. The homepage connects visitors to the Geologic Hazards team's three main areas of endeavor. Geomagnetism provides links to the National Geomagnetic Information Center; Magnetic Observatories, Models, and Charts; and the Geomagnetic Information Node, which receives geomagnetic observatory data from around the world. The Landslide group studies the "causes and mechanisms of ground failure" to prevent "long-term losses and casualties." Their section provides links to the program and information center, publications, events, and current projects. The Earthquakes department hosts a wealth of information, including neotectonics, engineering seismology, and paleoseismology. Interactive maps are also provided.

398

External Resource: Geology Jeopardy  

NSDL National Science Digital Library

This interactive Geology Jeopardy game can by used by the individual to review concepts in earth science or in the classroom as a classroom activity. Topics: rocks, minerals, topography, plate tectonics, weathering, erosion, astronomy, meteorology.

1900-01-01

399

Geology and Human Health  

NSDL National Science Digital Library

This site contains a variety of educational and supporting materials for faculty teaching in the emerging field of geology and human health. You will find links to internet resources, books, teaching activities, and a group email list, as well as posters, presentations and discussions from the spring 2004 workshop on Geology and Human Health. These resources reflect the contributions of faculty members from across the country and the collections will continue to grow as materials are developed.

400

Introduction to Petroleum Geology  

Microsoft Academic Search

\\u000a \\u000a Petroleum geology comprises those geological disciplines which are of greatest significance for the finding and recovery of oil and gas. Since\\u000a most of the obvious and “easy to find” petroleum already has been discovered it is necessary to use sophisticated methods\\u000a in the exploration of sedimentary basins. These include advanced geophysical techniques and basin modelling. There is also\\u000a much more

Knut Bjørlykke

401

Geology of Scotland  

Microsoft Academic Search

MAY I supplement Prof. Green's history of geological mapping in Scotland (NATURE, vol. xlvii. p. 49) by pointing out that Mr. Cruchley published, on March 23, 1840, ``A Geological Map of Scotland by Dr. MacCulloch, F.R.S., &c., published by order of the Lords of the Treasury by S. Arrowsmith, Hydrographer to the King.'' This fine map is on the scale

Grenville A. J. Cole

1892-01-01

402

Interpreting Geologic Sections  

NSDL National Science Digital Library

Athro, Limited is a for-profit corporation that publishes high school and college level biology, earth science, and geology course supplements and independent learning materials on the Web. This site provides instruction in interpreting the order of events in three hypothetical and one real geological section. For each section there is a list of events and an animation of the history of the section once the student has decided on the order of events.

Morris, Paul

403

Integration and fusion of geological exploration data: a theoretical review of fuzzy logic approach  

Microsoft Academic Search

A geological survey project, including the exploration of nonrenewable resources, typically includes the following steps:\\u000a planning of the survey, field mapping, acquisition of data, achieving of data, processing and fusion of all relevant information,\\u000a which are closely followed by an interpretation of the final survey results. In this process, important spatial data layers\\u000a are topographic map, often digital elevation model

Wooil M. Moon

1998-01-01

404

Altered zinc transport disrupts mitochondrial protein processing/import in fragile X-associated tremor/ataxia syndrome  

PubMed Central

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that affects individuals who are carriers of small CGG premutation expansions in the fragile X mental retardation 1 (FMR1) gene. Mitochondrial dysfunction was observed as an incipient pathological process occurring in individuals who do not display overt features of FXTAS ( 1). Fibroblasts from premutation carriers had lower oxidative phosphorylation capacity (35% of controls) and Complex IV activity (45%), and higher precursor-to-mature ratios (P:M) of nDNA-encoded mitochondrial proteins (3.1-fold). However, fibroblasts from carriers with FXTAS symptoms presented higher FMR1 mRNA expression (3-fold) and lower Complex V (38%) and aconitase activities (43%). Higher P:M of ATPase ?-subunit (ATPB) and frataxin were also observed in cortex from patients that died with FXTAS symptoms. Biochemical findings observed in FXTAS cells (lower mature frataxin, lower Complex IV and aconitase activities) along with common phenotypic traits shared by Friedreich's ataxia and FXTAS carriers (e.g. gait ataxia, loss of coordination) are consistent with a defective iron homeostasis in both diseases. Higher P:M, and lower ZnT6 and mature frataxin protein expression suggested defective zinc and iron metabolism arising from altered ZnT protein expression, which in turn impairs the activity of mitochondrial Zn-dependent proteases, critical for the import and processing of cytosolic precursors, such as frataxin. In support of this hypothesis, Zn-treated fibroblasts showed a significant recovery of ATPB P:M, ATPase activity and doubling time, whereas Zn and desferrioxamine extended these recoveries and rescued Complex IV activity.

Napoli, Eleonora; Ross-Inta, Catherine; Wong, Sarah; Omanska-Klusek, Alicja; Barrow, Cedrick; Iwahashi, Christine; Garcia-Arocena, Dolores; Sakaguchi, Danielle; Berry-Kravis, Elizabeth; Hagerman, Randi; Hagerman, Paul J.; Giulivi, Cecilia

2011-01-01

405

Geological mapping of the moon  

NASA Astrophysics Data System (ADS)

A new 1:5,000,000 scale geological map of the moon has been compiled at the Geological Institute of the USSR Academy of Sciences. This paper gives a brief description of the legend of this map, and compares this map to previous geological maps compiled at the Geological Institute.

Sukhanov, A. L.

406

Visualization in Undergraduate Geology Courses  

Microsoft Academic Search

Visualization is an essential skill in undergraduate geology courses as it is for expert geologists. Geology students and geologists must visualize the shape of the land from topographic maps, the three-dimensional geometry of geologic structures from limited exposures, and the geologic history recorded in sequences of layers and in natural landscapes. Interactive animations have proven successful in helping college students

Stephen Reynolds; Julia Johnson; Michael Piburn; Debra Leedy; Joshua Coyan; Melanie Busch

407

Towards Pro-active Embodied Agents: On the Importance of Neural Mechanisms Suitable to Process Time Information  

NASA Astrophysics Data System (ADS)

In Embodied Cognitive Science, many studies have focused on reactive agents, i.e. agents that have no internal state and always respond in the same way to the same stimulus. However, this particular focus is not due to a rejection of the importance of internal states. Rather, it is due to the difficulty of developing pro-active embodied and situated agents, that is agents able to: (a) extract internal states by integrating sensorymotor information through time and, (b) later use these internal states to modulate their motor behaviour according to the current environmental circumstances. In this chapter we will focus on how pro-active agents can be developed and, more specifically, on which are the neural mechanisms that might favour the development of pro-active agents. By comparing the results of five sets of evolutionary experiments in which simulated robots are provided with different types of recurrent neural networks, we gain insight into the relation between the robots` capabilities and the characteristics of their neural controllers. We show how special mechanisms for processing information in time facilitate the exploitation of internal states.

de Croon, G.; Nolfi, S.; Postma, E. O.

408

Nordic geoscience and the 3rd international geological congress: Introduction  

Microsoft Academic Search

Geology has been of profound importance for the Nordic countries since\\u000a the Middle Ages. Strong economies were built on an understanding of the\\u000a occurrence in bedrock of minerals containing metals, e.g., silver,\\u000a copper, zinc and iron, and eventually led to the establishment of the\\u000a first Geological Surveys in Norway and Sweden in the middle of the\\u000a nineteenth century. The geology

David G. Gee; Harald Brekke; Raimo Lahtinen; Freysteinn Sigmundsson; Bjoern Sundquist; Hans Thybo; Paer Weihed

2008-01-01

409

Is in-stream processing an important control on spatial changes in carbon fluxes in headwater catchments?  

PubMed

Data on small-scale spatial variations in instantaneous fluxes and concentrations of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and free carbon dioxide (CO2) are presented for a small acidic headwater stream in NE Scotland. Chloride is used as a conservative element to estimate additional, diffuse inputs of water into the main stem of the stream, other than those from tributaries. Downstream changes in instantaneous carbon fluxes were calculated and then used to estimate losses and gains of carbon within the stream system. Dissolved organic carbon concentrations in the stream ranged from 1.19-6.06 mg l(-1) at its source to a maximum of 10.0-25.3 mg l(-1) as the stream passed through deep peats; DOC concentrations then declined in the lower part of the catchment. DIC concentrations were initially low, increased to 1.5-3.0 mg l(-1) and then decreased to 0.1-1.65 mg l(-1) at the lowest site. Free CO2 concentrations increased from 0.35 mg l(-1) at the stream source to 3.30 mg l(-1) as the stream passed through the peat dominated area. Continually high inputs of CO2-rich water (> 6.0 mg l(-1)) from tributaries maintained these high concentrations in the main stem, until approximately 1.74 km downstream, when there was a rapid decline in concentration. Significant changes in DOC, DIC and CO2 fluxes occur over a distance of 2.7 km downstream from the stream source to the catchment outlet. Between 5.64-41.5 mg C s(-1) as DOC and 2.52-16.2 mg C s(-1) as DIC are removed from the water column. Between 6.81 and 19.0 mg C s(-1) as CO2 is lost along the stream length as progressive equilibration with the atmosphere occurs. We estimate that 11.6-17.6% of the total DOC flux is removed from streamwater by in-stream processes. Dissolved inorganic carbon (HCO3- and free CO2) losses are in excess of nine times its measured flux at the outlet of the catchment. These results suggest that in-stream processing of DOC and DIC and outgassing of CO2 are important controls on the spatial variability of carbon fluxes within headwater streams in upland catchments dominated by organic-rich soils. PMID:11227263

Dawson, J J; Bakewell, C; Billett, M F

2001-01-29

410

Geologic effects on groundwater salinity and discharge into an estuary  

USGS Publications Warehouse

Submarine groundwater discharge (SGD) can be an important pathway for transport of nutrients and contaminants to estuaries. A better understanding of the geologic and hydrologic controls on these fluxes is critical for their estimation and management. We examined geologic features, porewater salinity, and SGD rates and patterns at an estuarine study site. Seismic data showed the existence of paleovalleys infilled with estuarine mud and peat that extend hundreds of meters offshore. A low-salinity groundwater plume beneath this low-permeability fill was mapped with continuous resistivity profiling. Extensive direct SGD measurements with seepage meters (n = 551) showed fresh groundwater discharge patterns that correlated well with shallow porewater salinity and the hydrogeophysical framework. Small-scale variability in fresh and saline discharge indicates influence of meter-scale geologic heterogeneity, while site-scale discharge patterns are evidence of the influence of the paleovalley feature. Beneath the paleovalley fill, fresh groundwater flows offshore and mixes with saltwater before discharging along paleovalley flanks. On the adjacent drowned interfluve where low-permeability fill is absent, fresh groundwater discharge is focused at the shoreline. Shallow saltwater exchange was greatest across sandy sediments and where fresh SGD was low. The geologic control of groundwater flowpaths and discharge salinity demonstrated in this work are likely to affect geochemical reactions and the chemical loads delivered by SGD to coastal surface waters. Because similar processes are likely to exist in other estuaries where drowned paleovalleys commonly cross modern shorelines, the existence and implications of complex hydrogeology are important considerations for studies of groundwater fluxes and related management decisions.

Russonielloa, Christopher J.; Fernandeza, Cristina; Brattonb, John F.; Banaszakc, Joel F.; Krantzc, David E.; Andresd, Scott; Konikowe, Leonard F.; Michaela, Holly A.

2013-01-01

411

Geological research for public outreach and education in Lithuania  

NASA Astrophysics Data System (ADS)

Successful IYPE activities and implementation of Geoheritage day in Lithuania increased public awareness in geology. A series of projects introducing geology to the general public and youth, supported by EU funds and local communities, were initiated. Researchers from the scientific and applied geology institutions of Lithuania participated in these projects and provided with the geological data. In one case, the Lithuanian Survey of Protected Areas supported the installation of a series of geological exhibitions in several regional and national parks. An animation demonstrating glacial processes was chosen for most of these because the Lithuanian surface is largely covered with sedimentary deposits of the Nemunas (Weichselian) glaciation. Researchers from the Lithuanian Geological Survey used the mapping results to demonstrate real glacial processes for every chosen area. In another case, 3D models showing underground structures of different localities were based on detailed geological maps and profiles obtained for that area. In case of the Sartai regional park, the results of previous geological research projects provided the possibility to create a movie depicting the ca. 2 Ga geological evolution of the region. The movie starts with the accretion of volcanic island arcs on the earlier continental margin at ca. 2 Ga and deciphers later Precambrian tectonic and magmatic events. The reconstruction is based on numerous scientific articles and interpretation of geophysical data. Later Paleozoic activities and following erosion sculptured the surface which was covered with several ice sheets in Quaternary. For educational purpose, a collection of minerals and rocks at the Forestry Institute was used to create an exhibition called "Cycle of geological processes". Forestry scientists and their students are able to study the interactions of geodiversity and biodiversity and to understand ancient and modern geological processes leading to a soil formation. An aging exposition at the Museum of Erratic Boulders in NW Lithuania is being rearranged for educational purposes, to show the major rock types and their origins more clearly. A new exhibition is supplemented with computer portals presenting geological processes, geological quizzes, animations etc. Magmatism, metamorphism, sedimentation and other geological processes are demonstrated using erratic boulders brought by glaciers from Scandinavia and northern Russia. A part of the exhibition is devoted to glaciation processes and arrival of ice sheets to Lithuania. Visitors are able to examine large erratic boulder groups in a surrounding park and to enjoy beautiful environment. The exhibition also demonstrates mineral resources of Lithuania, different fossils and stones from a human body. In all cases it was recognised that a lack of geological information limits the use of geology for public outreach. Ongoing scientific research is essential in many places as well as a mediator's job for interpreting the results of highly specialised research results and to adapt them for public consumption.

Skridlaite, Grazina; Guobyte, Rimante

2013-04-01

412

Minnesota Geological Survey  

NSDL National Science Digital Library

The Minnesota Geological Survey (MGS) was established in 1872 as part of the University of Minnesota. The function of the MGS is to serve "the people of Minnesota by providing systematic geoscience information to support stewardship of water, land, and mineral resources." This website from the Digital Conservancy at the University of Minnesota provides access to all of items published by the MGS. The items are contained within the Collections area, and visitors will find headings here such as "Geology of Minnesota Parks," "County Atlas Series," and the "Bulletin of the Minnesota Geological and Natural History Survey." First-time visitors can check out the Recent Submissions area on the right-hand side of the page to look over some new findings, including hydrogeological maps of different counties around the state. One item that should not be missed is the "Geology of Minnesota: A Centennial Volume" from 1972. It's a tremendous volume and one that cannot be ignored by students of the physical landscape and geological history of the state.

2012-09-21

413

Centrifugation: an important pre-analytic factor that influences plasma microRNA quantification during blood processing.  

PubMed

Circulating microRNAs are robustly present in plasma or serum and have become a research focus as biomarkers for tumor diagnosis and prognosis. Centrifugation is a necessary factor for obtaining high-quality blood supernatant. Herein, we investigated one-step and two-step centrifugations, two centrifugal methods routinely used in microRNA study, to explore their effects on plasma microRNA quantification. The microRNAs obtained from one-step and two-step centrifugations were quantified by microarray and TaqMan-based real-time quantitative polymerase chain reaction (Q-PCR). Dynamic light scattering was performed to explore the difference underlying the two centrifugal methods. The results from the microarray containing 1,347 microRNAs showed that the signal detection rate was greatly decreased in the plasma sample prepared by two-step centrifugation. More importantly, the microRNAs missing in this plasma sample could be recovered and detected in the precipitate generated from the second centrifugation. Consistent with the results from microarray, a marked decrease of three representative microRNAs in two-step centrifugal plasma was validated by Q-PCR. According to the size distribution of all nanoparticles in plasma, there were fewer nanoparticles with size >1000 nm in two-step centrifugal plasma. Our experiments directly demonstrated that different centrifugation methods produced distinct quantities of plasma microRNAs. Thus, exosomes or protein complexes containing microRNAs may be involved in large nanoparticle formation and may be precipitated after two-step centrifugation. Our results remind us that sample processing methods should be first considered in conducting research. PMID:23601242

Zheng, Xiao-Hui; Cui, Cui; Zhou, Xin-Xi; Zeng, Yi-Xin; Jia, Wei-Hua

2013-04-19

414

Successful Drug Development Despite Adverse Preclinical Findings Part 1: Processes to Address Issues and Most Important Findings  

PubMed Central

Unexpected adverse preclinical findings (APFs) are not infrequently encountered during drug development. Such APFs can be functional disturbances such as QT prolongation, morphological toxicity or carcinogenicity. The latter is of particular concern in conjunction with equivocal genotoxicity results. The toxicologic pathologist plays an important role in recognizing these effects, in helping to characterize them, to evaluate their risk for man, and in proposing measures to mitigate the risk particularly in early clinical trials. A careful scientific evaluation is crucial while termination of the development of a potentially useful drug must be avoided. This first part of the review discusses processes to address unexpected APFs and provides an overview over typical APFs in particular classes of drugs. If the mode of action (MoA) by which a drug candidate produces an APF is known, this supports evaluation of its relevance for humans. Tailor-made mechanistic studies, when needed, must be planned carefully to test one or several hypotheses regarding the potential MoA and to provide further data for risk evaluation. Safety considerations are based on exposure at no-observed-adverse-effect levels (NOAEL) of the most sensitive and relevant animal species and guide dose escalation in clinical trials. The availability of early markers of toxicity for monitoring of humans adds further safety to clinical studies. Risk evaluation is concluded by a weight of evidence analysis (WoE) with an array of parameters including drug use, medical need and alternatives on the market. In the second part of this review relevant examples of APFs will be discussed in more detail.

Kuroda, Junji; Plassmann, Stephanie; Prentice, David E.

2010-01-01

415

Connecting Soils and Glacial Geology  

NSDL National Science Digital Library

The goal of this activity is to provide students an opportunity to connect soil science to surficial geology by using a Soil Surveys. By the end of the activity, students should be able to use a Soil Survey to identify and interpret landforms and surficial features. This activity can be adapted to variety of process (ex. eolian deposits, glacial deposits, bedrock weathering, etc.). County-level soil surveys are available in both paper and online formats for the majority of the United States. Designed for a geomorphology course Has minimal/no quantitative component

Dolliver, Holly

416

Geochronology of the Karadere basement (NW Turkey) and implications for the geological evolution of the Istanbul zone  

Microsoft Academic Search

Earlier geological work in the Istanbul zone, western Pontide tectonic belt, has revealed the presence of extensive basement outcrops exposed underneath Palaeozoic and Mesozoic to Tertiary cover sequences. The basement of suspected Neoproterozoic age plays an important role in understanding the crustal accretion process in NW Turkey. We report the first results of a detailed Pb-Pb and U-Pb zircon study

F. Chen; W. Siebel; M. Satir; M. Terzio?lu; K. Saka

2002-01-01

417

Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Remedial Action Selection Report, Appendix B of Attachment 2: Geology report, Final  

SciTech Connect

The uranium processing site near Naturita, Colorado, is one of 24 inactive uranium mill sites designated to be cleaned up by the US Department of Energy (DOE) under the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), 42 USC {section} 7901 et seq. Part of the UMTRCA requires that the US Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the US Environmental Protection Agency (EPA). Included in the RAP is this Remedial Action Selection Report (RAS), which describes the proposed remedial action for the Naturita site. An extensive amount of data and supporting information has been generated and evaluated for this remedial action. These data and supporting information are not incorporated into this single document but are included or referenced in the supporting documents. The RAP consists of this RAS and four supporting documents or attachments. This Attachment 2, Geology Report describes the details of geologic, geomorphic, and seismic conditions at the Dry Flats disposal site.

Not Available

1994-03-01

418

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.

419

Geology of Io  

NASA Astrophysics Data System (ADS)

Geologic mapping of the Jovian satellite Io has been completed at 1:15,000,000 scale for an area lying between +40 and -90 deg latitude and 230 and 45 deg longitude, which includes portions of the Ruwa Patera quadrangle (Ji2) and the Lerna Region (Ji4) and the westernmost section of the Colchis Region (Ji3). Image resolution in the mapped area is commonly 0.5 to 2 km/pxl. High resolution areas (less than .5 km/pxl) are located near the south pole (Lerna Region) and in eastern Ruwa Patera quadrangle. Geologic maps for the Ruwa Patera quadrangle (Ji2) and the Lerna Region (Ji4) have been produced at 1:5,000,000 scale. The present effort reexamines the previously mapped areas and synthesizes the geology of Io on a global scale.

Greeley, R.; Craddock, R. A.; Crown, D. A.; Leshin, L. A.; Schaber, G. G.

1987-05-01

420

Geology for Everyone  

NSDL National Science Digital Library

This Geological Survey of Ireland website can increase the public's excitement about geology by offering simple, straightforward materials on the basics of geology. The website is divided into numerous themes such as Volcanoes, Rocks, Caves, and the Water Cycle. The links from each of the headings introduce the topic with simple descriptions and remarkable pictures and offer easy experiments when applicable. Students and educators can take virtual tours of the Ox Mountains, Killiney Beach, and other Irish landscapes. Everyone should visit the Landscapes for the Living link, which offers outstanding images of the diverse landscapes of Europe. While some of the themes are currently under construction, including Planet Earth, Plate Tectonics, and Earthquakes, the authors indicate that these materials will be added in the near future.