Science.gov

Sample records for limestone exploration play

  1. The Mississippian Leadville Limestone Exploration Play, Utah and Colorado-Exploration Techniques and Studies for Independents

    SciTech Connect

    Thomas Chidsey

    2008-09-30

    The Mississippian (late Kinderhookian to early Meramecian) Leadville Limestone is a shallow, open-marine, carbonate-shelf deposit. The Leadville has produced over 53 million barrels (8.4 million m{sup 3}) of oil/condensate from seven fields in the Paradox fold and fault belt of the Paradox Basin, Utah and Colorado. The environmentally sensitive, 7500-square-mile (19,400 km{sup 2}) area that makes up the fold and fault belt is relatively unexplored. Only independent producers operate and continue to hunt for Leadville oil targets in the region. The overall goal of this study is to assist these independents by (1) developing and demonstrating techniques and exploration methods never tried on the Leadville Limestone, (2) targeting areas for exploration, (3) increasing deliverability from new and old Leadville fields through detailed reservoir characterization, (4) reducing exploration costs and risk especially in environmentally sensitive areas, and (5) adding new oil discoveries and reserves. The final results will hopefully reduce exploration costs and risks, especially in environmentally sensitive areas, and add new oil discoveries and reserves. The study consists of three sections: (1) description of lithofacies and diagenetic history of the Leadville at Lisbon field, San Juan County, Utah, (2) methodology and results of a surface geochemical survey conducted over the Lisbon and Lightning Draw Southeast fields (and areas in between) and identification of oil-prone areas using epifluorescence in well cuttings from regional wells, and (3) determination of regional lithofacies, description of modern and outcrop depositional analogs, and estimation of potential oil migration directions (evaluating the middle Paleozoic hydrodynamic pressure regime and water chemistry). Leadville lithofacies at Libon field include open marine (crinoidal banks or shoals and Waulsortian-type buildups), oolitic and peloid shoals, and middle shelf. Rock units with open-marine and restricted

  2. Exploration for limestone deposit at Onigbedu, South-Western Nigeria

    NASA Astrophysics Data System (ADS)

    Oyedele, Kayode F.; Oladele, Sunday; Emakpor, Charles A.

    2016-09-01

    The Onigbedu limestone deposit was investigated using the aeromagnetic data, resistivity soundings and borings with the aim of characterizing the limestone deposit and estimating its reserves. The subsurface structural features and depth to basement were identified with the analysis of aeromagnetic data. Twenty nine boreholes were drilled for subsurface appraisal and correlation of the limestone deposit. Eighty nine Vertical Electrical Sounding (VES) were acquired using the Schlumberger array. The results showed NE-SW trending lineaments that segmented the limestone. Depth to basement varied from 144.2 m to 1090 m. The VES results showed four to six layers indicating the topsoil (7-315 Ωm), clay (2-25 Ωm), shale (6-31 Ωm), limestone (20-223 Ωm), sandstone (>200 Ωm) and sandy materials. The VES results correlated well with the lithological unit delineated from the borehole. The overburden thickness ranged from 3.3 m to 28 m, while the limestone thickness varies between 18.1 m and 48.3 m. The limestone reserve was estimated at 1.9 × 109 t. This study concluded that the study area had vast occurrence of the limestone deposits, which would be of economic importance, if exploited.

  3. Curious Play: Children's Exploration of Nature

    ERIC Educational Resources Information Center

    Gurholt, Kirsti Pedersen; Sanderud, Jostein Rønning

    2016-01-01

    This article explores the concept of "curious play" as a theoretical framework to understand and communicate children's experiences of free play in nature. The concept emerged interactively from three sources of inspiration: an ethnographically inspired study of children playing in nature; as a critique of the concept of "risky…

  4. Curious Play: Children's Exploration of Nature

    ERIC Educational Resources Information Center

    Gurholt, Kirsti Pedersen; Sanderud, Jostein Rønning

    2016-01-01

    This article explores the concept of "curious play" as a theoretical framework to understand and communicate children's experiences of free play in nature. The concept emerged interactively from three sources of inspiration: an ethnographically inspired study of children playing in nature; as a critique of the concept of "risky…

  5. Current Soviet exploration plays: Success and potential

    SciTech Connect

    Grace, J.D. )

    1991-03-01

    Soviet hydrocarbon exploration in the 1980s took four distinct directions. First was extension exploration and the search for smaller new fields in discrete traps in traditional producing regions, such as the Apsheron Peninsula, North Caucasus, and Volga-Urals. This strategy produced a large number of small discoveries close to established infrastructure. Second was new field exploration in West Siberia in the stratigraphically complex Jurassic and the lower Neocomian sections. Third was expansion of the prolific gas plays in northern West Siberia. Exploratory success in West Siberia has created a backlog of several hundred discoveries awaiting full delineation and development. Most of these fields are distant from the established oil production center in the Middle Ob region and, therefore, may remain in inventory. Fourth was initial tests of new exploration frontiers, most important, the Paleozoic and Mesozoic plays of the Barents and Kara seas and the subsalt plays of the North Caspian basin. While these plays have yielded very important discoveries, significant technological barriers impede their development. The outlook for Soviet oil exploration in the 1990s is for significant opportunities for discovery of large volumes of oil, but at radically increasing exploration and production costs. In established regions, these costs arise from small field sizes and low well productivities. In frontier regions, exploitation of new fields will require technology not currently available in the USSR. The outlook for gas exploration continues to be very bright, as the onshore northern West Siberia is not fully explored and initial results from the Barents and Kara seas promise more very large gas discoveries.

  6. Mathematical Situations of Play and Exploration

    ERIC Educational Resources Information Center

    Vogel, Rose

    2013-01-01

    The mathematical situations of play and exploration introduced here have been developed as an empirical research instrument for the longitudinal study "erStMaL" (early Steps in Mathematics Learning). They are designed as situations that allow children and a guiding adult to construct situation-related knowledge in common dialogue…

  7. Playing with Power: An Outdoor Classroom Exploration

    ERIC Educational Resources Information Center

    Haywood-Bird, Eden

    2017-01-01

    In this ethnographic research, discovery of how preschool-aged children use play to wield their individual power in the outdoors is documented in a single classroom. Embedded as a participant-researcher and working from constructivist and critical theory orientations, the researcher seeks to understand how children use their play to construct the…

  8. Exploring the enjoyment of playing browser games.

    PubMed

    Klimmt, Christoph; Schmid, Hannah; Orthmann, Julia

    2009-04-01

    Browser games--mostly persistent game worlds that can be used without client software and monetary cost with a Web browser--belong to the understudied digital game types, although they attract large player communities and motivate sustained play. The present work reports findings from an online survey of 8,203 players of a German strategy browser game ("Travian"). Results suggest that multiplayer browser games are enjoyed primarily because of the social relationships involved in game play and the specific time and flexibility characteristics ("easy-in, easy-out"). Competition, in contrast, seems to be less important for browser gamers than for users of other game types. Findings are discussed in terms of video game enjoyment and game addiction.

  9. Cyrenaican platform: structure, stratigraphy, and exploration play concepts

    SciTech Connect

    Ross, C.M.; Zegaar, M.N.

    1985-02-01

    The structural and stratigraphic history of the Cyrenaican platform of eastern Libya is closely related to that of both the Sirte basin and the Western Desert of Egypt. At the end of the Paleozoic Hercynian orogeny, this area comprised the eastern end of the Sirte arch, the precursor of the Sirte basin. When the arch collapsed in the mid-Cretaceous, initiating the Sirte basin, the Cyrenaican area remained relatively high. A northwest-southeast trending high, the Gabboub arch, formed on the platform in the early Mesozoic, dividing the region into three areas: the high itself, a deep on the southwestern flank related to the Sirte basin, and a deep on the northeastern flank, which plunges into the offshore and appears to relate to the downwarped offshore area of the Western Desert of Egypt. Sediments of every age, except Triassic, are found in Cyrenaica. Paleozoic sediments are composed primarily of quartzitic sandstones and shales with lesser amounts of limestone, dolomites, and anhydrites. Mesozoic sediments are a mixture of clastics and carbonates. Cenozoic sediments are predominantly limestones, dolomites, and anhydrites with some sandstones and shales. Environments of deposition range from continental to deep marine. The Cyrenaican area has not been heavily explored and, until recently, no commercial hydrocarbons were found. Drilling on surface structures of some of the first wells in Libya resulted in one Devonian gas well. A reported 5600 BOPD Cretaceous discovery offshore Benghazi in mid-1984 demonstrates that hydrocarbon potential exists where thick sediments have been preserved.

  10. Playful Invention and Exploration. Final Evaluation Report: Executive Summary

    ERIC Educational Resources Information Center

    St. John; Mark; Carroll, Becky; Helms, Jen; Smith, Anita

    2008-01-01

    PIE (Playful Invention and Exploration) is a unique approach to learning that centers on the use of technology and design challenges to create powerful learning experiences in informal education settings. The Playful Invention and Exploration (PIE) Institute project was funded in 2005 by the National Science Foundation (NSF). Overall, 150…

  11. Active Play: Exploring the Influences on Children's School Playground Activities

    ERIC Educational Resources Information Center

    Hyndman, Brendon; Benson, Amanda; Telford, Amanda

    2016-01-01

    Because children spend so much of their time in schools, their playgrounds offer a good setting for promoting active play in young lives. Teachers, instead of considering active play a taxing demand on their busy day, have begun to develop an informal curriculum for it. The authors review the research on children's active play and explores its…

  12. Contexts of Childhood and Play: Exploring Parental Perceptions

    ERIC Educational Resources Information Center

    Singh, Asha; Gupta, Deepa

    2012-01-01

    The article explores cross-cultural notions of play in childhood among parents based on empirical investigations in two economically diverse residential areas in a metropolis in India. All parents had an unquestionable belief in an epistemic grounding of play in children's lives. However, parents begin to question play timings and children's…

  13. Contexts of Childhood and Play: Exploring Parental Perceptions

    ERIC Educational Resources Information Center

    Singh, Asha; Gupta, Deepa

    2012-01-01

    The article explores cross-cultural notions of play in childhood among parents based on empirical investigations in two economically diverse residential areas in a metropolis in India. All parents had an unquestionable belief in an epistemic grounding of play in children's lives. However, parents begin to question play timings and children's…

  14. Exploring Language Awareness through Students' Engagement in Language Play

    ERIC Educational Resources Information Center

    Ahn, So-Yeon

    2016-01-01

    The present study explores Korean students' demonstration of language awareness through their engagement in language play. Grounded in the understanding of the relationship between language play and an "engagement with language" (EWL) perspective, this ethnographic and discourse analytic study investigates how Korean students aged 11-15…

  15. Exploring Language Awareness through Students' Engagement in Language Play

    ERIC Educational Resources Information Center

    Ahn, So-Yeon

    2016-01-01

    The present study explores Korean students' demonstration of language awareness through their engagement in language play. Grounded in the understanding of the relationship between language play and an "engagement with language" (EWL) perspective, this ethnographic and discourse analytic study investigates how Korean students aged 11-15…

  16. Limestone Caverns

    ERIC Educational Resources Information Center

    Powell, Richard L.

    1970-01-01

    Describes the origin of limestone caverns, using Mammoth Cave as an example, with particular reference to the importance of groundwater information of caverns, the present condition of groundwater, and how caverns develop within fluctuating groundwater zones. (BR)

  17. Limestone Caverns

    ERIC Educational Resources Information Center

    Powell, Richard L.

    1970-01-01

    Describes the origin of limestone caverns, using Mammoth Cave as an example, with particular reference to the importance of groundwater information of caverns, the present condition of groundwater, and how caverns develop within fluctuating groundwater zones. (BR)

  18. Creating a Geologic Play Book for Trenton-Black River Appalachian Basin Exploration

    SciTech Connect

    Douglas G. Patchen; Taury Smith; Ron Riley; Mark Baranoski; David Harris; John Hickman; John Bocan; Michael Hohn

    2005-09-30

    Preliminary isopach and facies maps, combined with a literature review, were used to develop a sequence of basin geometry, architecture and facies development during Cambrian and Ordovician time. The main architectural features--basins, sub basins and platforms--were identified and mapped as their positions shifted with time. This is significant because a better understanding of the control of basin geometry and architecture on the distribution of key facies and on subsequent reservoir development in Ordovician carbonates within the Trenton and Black River is essential for future exploration planning. Good exploration potential is thought to exist along the entire platform margin, where clean grainstones were deposited in skeletal shoals from Indiana thorough Ohio and Ontario into Pennsylvania. The best reservoir facies for the development of hydrothermal dolomites appears to be these clean carbonates. This conclusion is supported by observations taken in existing fields in Indiana, Ontario, Ohio and New York. In contrast, Trenton-Black River production in Kentucky and West Virginia has been from fractured, but non-dolomitized, limestone reservoirs. Facies maps indicate that these limestones were deposited under conditions that led to a higher argillaceous content than the cleaner limestones deposited in higher-energy environments along platform margins. However, even in the broad area of argillaceous limestones, clean limestone buildups have been observed in eastern outcrops and, if present and dolomitized in the subsurface, may provide additional exploration targets. Structure and isopach maps developed as part of the structural and seismic study supported the basin architecture and geometry conclusions, and from them some structural control on the location of architectural features may be inferred. This portion of the study eventually will lead to a determination of the timing relative to fracturing, dolomitization and hydrocarbon charging of reservoirs in the

  19. Limestone geomorphology

    SciTech Connect

    Trudgill, S.

    1985-01-01

    This book focuses on recent work on geomorphological processes and relates them to established theories of landform development. Special attention is paid to soil processes, marine geomorphology, chemical processes and future work on process-form relationships in the context of dated sequences of cave deposits. There are discussions of limestone landforms and other carbonate rocks, caves, hydrological networks, features of karst, morphometry, and coastal landforms and solution chemistry of limestones.

  20. Parents’ perceptions of preschool activities: exploring outdoor play

    PubMed Central

    Jayasuriya, Avanthi; Williams, Marcia; Edwards, Todd; Tandon, Pooja

    2016-01-01

    Research Findings Outdoor play is important for children’s health and development, yet many preschool-aged children in childcare settings do not receive the recommended 60 minutes/day of outdoor play. Childcare providers have previously described parent-related barriers to increasing outdoor playtime, including parents not providing appropriate clothing for their children and parents’ preference for academics over active play. This study explored parent perceptions and knowledge of outdoor playtime in childcare environments. On average, parents reported wanting their child to spend significantly more time playing outside during a full day of childcare than the recommended minimum. However, over one-half of parents reported that they did not know how much time their child actually spent playing outside and 43% reported that they did not know their childcare center’s outdoor play policies. Practice or Policy Childcare providers may over-perceive parent-related barriers to outdoor play. Parents generally support outdoor play for their preschooler during center-based childcare but are not well informed about outdoor playtime and policies. Encouraging communication between parents and early childhood educators about these topics could lead to more universal support and strategies for promoting outdoor and active play opportunities for children which are important for their health and development.

  1. Let's Play: Exploring Literacy Practices in an Emerging Videogame Paratext

    ERIC Educational Resources Information Center

    Burwell, Catherine; Miller, Thomas

    2016-01-01

    This article explores the literacy practices associated with Let's Play videos (or LPs) on YouTube. A hybrid of digital gaming and video, LPs feature gameplay footage accompanied by simultaneous commentary recorded by the player. Players may set out to promote, review, critique or satirize a game. In recent years, LPs have become hugely popular…

  2. Let's Play: Exploring Literacy Practices in an Emerging Videogame Paratext

    ERIC Educational Resources Information Center

    Burwell, Catherine; Miller, Thomas

    2016-01-01

    This article explores the literacy practices associated with Let's Play videos (or LPs) on YouTube. A hybrid of digital gaming and video, LPs feature gameplay footage accompanied by simultaneous commentary recorded by the player. Players may set out to promote, review, critique or satirize a game. In recent years, LPs have become hugely popular…

  3. Exploring children's movement characteristics during virtual reality video game play.

    PubMed

    Levac, Danielle; Pierrynowski, Michael R; Canestraro, Melissa; Gurr, Lindsay; Leonard, Laurean; Neeley, Christyann

    2010-12-01

    There is increasing interest in the use of commercially-available virtual reality video gaming systems within pediatric rehabilitation, yet little is known about the movement characteristics of game play. This study describes quantity and quality of movement during Nintendo Wii and Wii Fit game play, explores differences in these movement characteristics between games and between novice and experienced players, and investigates whether motivation to succeed at the game impacts movement characteristics. Thirty-eight children (aged 7-12) with and without previous game experience played Wii (boxing and tennis) and Wii Fit (ski slalom and soccer heading) games. Force plate data provided center of pressure displacement (quantity) and processed pelvis motion indicated smoothness of pelvic movement (quality). Children rated their motivation to succeed at each game. Movement quantity and quality differed between games (p<.001). Children with previous experience playing Wii Fit games demonstrated greater movement quantity during Wii Fit game play (p<.001); quality of movement did not differ between groups. Motivation to succeed did not influence the relationship between experience and outcomes. Findings enhance clinical understanding of this technology and inform the development of research questions to explore its potential to improve movement skills in children with motor impairments. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. The southern Bonaparte Gulf, northwest Australia - New exploration plays

    SciTech Connect

    Dauzacker, M.V.; Durrant, J.M.; France, R. ); Nilsen, T. )

    1990-05-01

    Integration of regional exploration data with new basin model concepts has generated new exploration plays in the offshore area defined as the Southern Bonaparte Gulf. This area represents a unique hydrocarbon habitat significantly different from adjacent areas. Early exploration (seven wells), targeting structural highs, encountered numerous hydrocarbon shows. Of most recent significance, Turtle-1 (1984) targeted a midbasin MS-I high recovering degraded oils in the MS-III section. Turtle-2 (1989) tested an additional 320-m-thick, MS-II onlap, encountering within fractured intervals significant oil and gas influx accompanied by massive lost circulation. Significant live oil (nondegraded) was produced on test despite formation damage inflicted during the 14-day well control period. Within the MS-III section thin incompetent seals and meteoric waters have resulted in small, degraded, low-GOR (gas/oil ratio) oil accumulations. In contrast the MS-II section has competent seals and exhibits high-GOR live oil. In consequence, given suitable models for porosity development, MS-II is highly prospective, indicating new exploratory plays: (1) MS-II fractured, stratigraphic pinch-outs flanking MS-I structures, (2) MS-II stacked turbidites and basin floor fans deposited in salt withdrawal subbasins, (3) MS-II carbonate banks within the subbasin's marginal carbonate complexes, (4) MS-I reefs localized over early salt structures and onlapped by MS-II sediments, and (5) MS-II structural and stratigraphic traps associated with diapiric salt. By virtue of the stratigraphic and structural relationship of MS-U sediments, generally onlapping the flanks of the structural highs originally targeted, these new plays have not been tested in optimal locations. A new phase of exploration specifically targeted at these plays is planned.

  5. CREATING A GEOLOGIC PLAY BOOK FOR TRENTON-BLACK RIVER APPALACHIAN BASIN EXPLORATION

    SciTech Connect

    Douglas G. Patchen; Katharine Lee Avary; John M. Bocan; Michael Hohn; John B. Hickman; Paul D. Lake; James A. Drahovzal; Christopher D. Laughrey; Jaime Kostelnik; Taury Smith; Ron Riley; Mark Baranoski

    2005-04-01

    The Trenton-Black River Appalachian Basin Research Consortium has made significant progress toward their goal of producing a geologic play book for the Trenton-Black River gas play. The final product will include a resource assessment model of Trenton-Black River reservoirs; possible fairways within which to concentrate further studies and seismic programs; and a model for the origin of Trenton-Black River hydrothermal dolomite reservoirs. All seismic data available to the consortium have been examined. Synthetic seismograms constructed for specific wells have enabled researchers to correlate the tops of 15 stratigraphic units determined from well logs to seismic profiles in New York, Pennsylvania, Ohio, West Virginia and Kentucky. In addition, three surfaces for the area have been depth converted, gridded and mapped. A 16-layer velocity model has been developed to help constrain time-to-depth conversions. Considerable progress was made in fault trend delineation and seismic-stratigraphic correlation within the project area. Isopach maps and a network of gamma-ray cross sections supplemented with core descriptions allowed researchers to more clearly define the architecture of the basin during Middle and Late Ordovician time, the control of basin architecture on carbonate and shale deposition and eventually, the location of reservoirs in Trenton Limestone and Black River Group carbonates. The basin architecture itself may be structurally controlled, and this fault-related structural control along platform margins influenced the formation of hydrothermal dolomite reservoirs in original limestone facies deposited in high energy environments. This resulted in productive trends along the northwest margin of the Trenton platform in Ohio. The continuation of this platform margin into New York should provide further areas with good exploration potential. The focus of the petrographic study shifted from cataloging a broad spectrum of carbonate rocks that occur in the

  6. Understanding Positive Play: An Exploration of Playing Experiences and Responsible Gambling Practices.

    PubMed

    Wood, Richard T A; Griffiths, Mark D

    2015-12-01

    This study is one of the first to explore in detail the behaviors, attitudes and motivations of players that show no signs of at-risk or problem gambling behavior (so-called 'positive players'). Via an online survey, 1484 positive players were compared with 209 problem players identified using the Lie/Bet screen. The study identified two distinct groups of positive players defined according to their motivations to play and their engagement with responsible gambling (RG) practices. Those positive players that played most frequently employed the most personal RG strategies. Reasons that positive players gave for gambling were focused on leisure (e.g., playing for fun, being entertained, and/or winning a prize). By contrast, problem gamblers were much more focused upon modifying mood states (e.g., excitement, relaxation, depression and playing when bored or upset). The present study also suggests that online gambling is not, by default, inherently riskier than gambling in more traditional ways, as online gambling was the most popular media by which positive players gambled. Furthermore, most positive players reported that it was easier to stick to their limits when playing the National Lottery online compared to traditional retail purchasing of tickets. Problem players were significantly more likely than positive players to gamble with family and friends, suggesting that, contrary to a popular RG message, social play may not be inherently safer than gambling alone. It is proposed that players (generally) may identify more with the term 'positive play' than the term 'RG' which is frequently interpreted as being aimed at people with gambling problems, rather than all players.

  7. Changing the game: exploring infants' participation in early play routines.

    PubMed

    Fantasia, Valentina; Fasulo, Alessandra; Costall, Alan; López, Beatriz

    2014-01-01

    Play has proved to have a central role in children's development, most notably in rule learning (Piaget, 1965; Sutton-Smith, 1979) and negotiation of roles and goals (Garvey, 1974; Bruner et al., 1976). Yet very little research has been done on early play. The present study focuses on early social games, i.e., vocal-kinetic play routines that mothers use to interact with infants from very early on. We explored 3-month-old infants and their mothers performing a routine game first in the usual way, then in two violated conditions: without gestures and without sound. The aim of the study is to investigate infants' participation and expectations in the game and whether this participation is affected by changes in the multimodal format of the game. Infants' facial expressions, gaze, and body movements were coded to measure levels of engagement and affective state across the three conditions. Results showed a significant decrease in Limbs Movements and expressions of Positive Affect, an increase in Gaze Away and in Stunned Expression when the game structure was violated. These results indicate that the violated game conditions were experienced as less engaging, either because of an unexpected break in the established joint routine, or simply because they were weaker versions of the same game. Overall, our results suggest that structured, multimodal play routines may constitute interactional contexts that only work as integrated units of auditory and motor resources, representing early communicative contexts which prepare the ground for later, more complex multimodal interactions, such as verbal exchanges.

  8. Changing the game: exploring infants' participation in early play routines

    PubMed Central

    Fantasia, Valentina; Fasulo, Alessandra; Costall, Alan; López, Beatriz

    2014-01-01

    Play has proved to have a central role in children's development, most notably in rule learning (Piaget, 1965; Sutton-Smith, 1979) and negotiation of roles and goals (Garvey, 1974; Bruner et al., 1976). Yet very little research has been done on early play. The present study focuses on early social games, i.e., vocal-kinetic play routines that mothers use to interact with infants from very early on. We explored 3-month-old infants and their mothers performing a routine game first in the usual way, then in two violated conditions: without gestures and without sound. The aim of the study is to investigate infants' participation and expectations in the game and whether this participation is affected by changes in the multimodal format of the game. Infants' facial expressions, gaze, and body movements were coded to measure levels of engagement and affective state across the three conditions. Results showed a significant decrease in Limbs Movements and expressions of Positive Affect, an increase in Gaze Away and in Stunned Expression when the game structure was violated. These results indicate that the violated game conditions were experienced as less engaging, either because of an unexpected break in the established joint routine, or simply because they were weaker versions of the same game. Overall, our results suggest that structured, multimodal play routines may constitute interactional contexts that only work as integrated units of auditory and motor resources, representing early communicative contexts which prepare the ground for later, more complex multimodal interactions, such as verbal exchanges. PMID:24936192

  9. Outcrop Analogue Studies in Geothermal Exploration - Characterization of fault zones in Triassic Muschelkalk limestones of the Upper Rhine Graben

    NASA Astrophysics Data System (ADS)

    Meier, S.; Bauer, J. F.; Philipp, S. L.

    2013-12-01

    The characterization of fault zones is of particular importance in geothermal reservoirs since there may be great effects on fluid flow. Fault zones generally consist of two major hydromechanical units: the fault core and the damage zone, surrounded by the host rock. To improve predictions of fracture system parameters for each unit and resulting estimations of reservoir permeabilities at depths we perform outcrop analogue studies. We analyze Middle Triassic Muschelkalk limestones that form one geothermal reservoir formation in the Upper Rhine Graben (southwest Germany) in quarries on its eastern graben shoulder. We measure the orientations and displacements of various fault zones and characterize the fracture systems within the fault zone units and in the host rock. Our studies show that damage zones are well developed even in smaller fault zones. Their fault cores, however, are narrow compared with that of fault zones with large displacements and comprise brecciated material, clay smear, host rock lenses or zones of mineralization. Based on the field data we use analytical models to estimate the permeabilities of the analyzed fracture systems. Results show increased fracture frequencies in the fault zone damage zones and larger fracture apertures parallel or subparallel to fault zone strike that lead to enhanced permeability compared with other orientations. Mineralized fractures accumulated in this direction in the 'Nussloch'-quarry indicate that these fractures were pathways for fault zone parallel fluid flow in the past. This shows that open fractures with orientations parallel to fault zones may be pathways for fault zone parallel fluid flow in geothermal reservoirs. By contrast, well-developed fault cores may be potential barriers for fluid flow in inactive fault zones. To build numerical models to analyze local stress fields and effects on fracture propagation for different fault zone types and geometries information on rock mechanical properties is

  10. Exploring Play/Playfulness and Learning in the Adult and Higher Education Classroom

    ERIC Educational Resources Information Center

    Tanis, David J.

    2012-01-01

    Play and playfulness and their role in learning are researched extensively in early childhood education. However, as the child matures into an adult, play and playfulness are given less attention in the teaching and learning process. In adult education, there is very little research about play/playfulness and its significance for learning. Despite…

  11. Exploring Play/Playfulness and Learning in the Adult and Higher Education Classroom

    ERIC Educational Resources Information Center

    Tanis, David J.

    2012-01-01

    Play and playfulness and their role in learning are researched extensively in early childhood education. However, as the child matures into an adult, play and playfulness are given less attention in the teaching and learning process. In adult education, there is very little research about play/playfulness and its significance for learning. Despite…

  12. Responsive Play: Exploring Play as Reader Response in a First Grade Classroom

    ERIC Educational Resources Information Center

    Flint, Tori K.

    2016-01-01

    Play in the school setting is a highly contested issue in today's restrictive academic environment. Although many early childhood educators advocate the use of play in their classrooms and emphasize the importance of play for children's learning and development, children beyond the preschool and kindergarten years are not often afforded…

  13. Responsive Play: Exploring Play as Reader Response in a First Grade Classroom

    ERIC Educational Resources Information Center

    Flint, Tori K.

    2016-01-01

    Play in the school setting is a highly contested issue in today's restrictive academic environment. Although many early childhood educators advocate the use of play in their classrooms and emphasize the importance of play for children's learning and development, children beyond the preschool and kindergarten years are not often afforded…

  14. Exploring the Uncanny Valley to Find the Edge of Play

    ERIC Educational Resources Information Center

    Eberle, Scott G.

    2009-01-01

    Play often rewards us with a thrill or a sense of wonder. But, just over the edge of play, uncanny objects like dolls, automata, robots, and realistic animations may become monstrous rather than marvelous. Drawing from diverse sources, literary evidence, psychological and psychoanalytic theory, new insights in neuroscience, marketing literature,…

  15. Parents' Perceptions of Preschool Activities: Exploring Outdoor Play

    ERIC Educational Resources Information Center

    Jayasuriya, Avanthi; Williams, Marcia; Edwards, Todd; Tandon, Pooja

    2016-01-01

    Research Findings: Outdoor play is important for children's health and development, yet many preschool-age children in child care settings do not receive the recommended 60 min/day of outdoor play. Child care providers have previously described parent-related barriers to increasing outdoor playtime, including parents not providing appropriate…

  16. Explorations in Teacher Characteristics: Playfulness in the Classroom Teacher.

    ERIC Educational Resources Information Center

    Lieberman, J. Nina

    Playfulness, a trait previously identified in kindergarten and high school pupils and found related to divergent thinking, was investigated in an exploratory study as a possible teacher characteristic. Sixteen teachers completed an open-ended questionnaire aimed at defining playfulness in teachers. A content analysis produced eight component…

  17. Parents' Perceptions of Preschool Activities: Exploring Outdoor Play

    ERIC Educational Resources Information Center

    Jayasuriya, Avanthi; Williams, Marcia; Edwards, Todd; Tandon, Pooja

    2016-01-01

    Research Findings: Outdoor play is important for children's health and development, yet many preschool-age children in child care settings do not receive the recommended 60 min/day of outdoor play. Child care providers have previously described parent-related barriers to increasing outdoor playtime, including parents not providing appropriate…

  18. What Play Means to Us: Exploring Children's Perspectives on Play in an English Year 1 Classroom

    ERIC Educational Resources Information Center

    Howe, Sally

    2016-01-01

    Opportunities for play and self-initiated activity, considered to be an important part of children's learning in early childhood settings, diminish as children progress into school. Previous studies suggest that losing time for play/self-initiated activity can impact negatively on children's attitudes to school learning. This article discusses the…

  19. What Play Means to Us: Exploring Children's Perspectives on Play in an English Year 1 Classroom

    ERIC Educational Resources Information Center

    Howe, Sally

    2016-01-01

    Opportunities for play and self-initiated activity, considered to be an important part of children's learning in early childhood settings, diminish as children progress into school. Previous studies suggest that losing time for play/self-initiated activity can impact negatively on children's attitudes to school learning. This article discusses the…

  20. Play.

    ERIC Educational Resources Information Center

    Rogers, Fred; Sharapan, Hedda

    1993-01-01

    Contends that, in childhood, work and play seem to come together. Says that for young children their play is their work, and the more adults encourage children to play, the more they emphasize important lifelong resource. Examines some uses of children's play, making and building, artwork, dramatic play, monsters and superheroes, gun play, and…

  1. Exploring Pedagogical Relationships in the Context of Free Play

    ERIC Educational Resources Information Center

    Hall-Kenyon, Kendra M.; Rosborough, Alessandro A.

    2017-01-01

    Early childhood advocates agree that positive teacher-child relationships are critical to classroom quality. Much research has emphasized quantifiable teacher characteristics and child outcomes without fully capturing the complexity of these relationships. Drawing on extensive classroom observations, two video-recorded free play sessions and…

  2. Children's Exploration of Physical Phenomena during Object Play

    ERIC Educational Resources Information Center

    Solis, S. Lynneth; Curtis, Kaley N.; Hayes-Messinger, Amani

    2017-01-01

    Researchers propose that experiencing and manipulating physical principles through objects allows young children to formulate scientific intuitions that may serve as precursors to learning in STEM subjects. This may be especially true when children discover these physical principles through object affordances during play. The present study…

  3. Variety in Play: Exploring Photographs by Helen Levitt

    ERIC Educational Resources Information Center

    Ruich, Lawrence J.

    2012-01-01

    Children and burgeoning adolescents' creativity blossom in play-based environments. Likewise, students as active social agents have the opportunity to examine the structures and processes that shape them. The photographic image intimates an aura of credibility, providing the students pause to reflect upon their socialized interactions. These…

  4. Exploring the Concept of Sustainable Development through Role-Playing

    ERIC Educational Resources Information Center

    Buchs, Arnaud; Blanchard, Odile

    2011-01-01

    The concept of sustainable development is used in everyday life by the general public, alongside researchers, institutions, and private companies. Nevertheless, its definition is far from being unequivocal. Clarifying the outline of the concept seems necessary. We have created a role-play for this purpose. Our article aims at depicting its main…

  5. Children's Exploration of Physical Phenomena during Object Play

    ERIC Educational Resources Information Center

    Solis, S. Lynneth; Curtis, Kaley N.; Hayes-Messinger, Amani

    2017-01-01

    Researchers propose that experiencing and manipulating physical principles through objects allows young children to formulate scientific intuitions that may serve as precursors to learning in STEM subjects. This may be especially true when children discover these physical principles through object affordances during play. The present study…

  6. Exploring Group Formation through Work and Play at Camp.

    ERIC Educational Resources Information Center

    Cain, Jim

    2003-01-01

    While working and playing together at camp, staff often work through most, if not all, of the stages of group formation, commonly referred to as forming, storming, norming, performing, and finally, transforming. Ten adventure-based games and activities are presented to help camp directors train staff and help them progress through these stages.…

  7. Variety in Play: Exploring Photographs by Helen Levitt

    ERIC Educational Resources Information Center

    Ruich, Lawrence J.

    2012-01-01

    Children and burgeoning adolescents' creativity blossom in play-based environments. Likewise, students as active social agents have the opportunity to examine the structures and processes that shape them. The photographic image intimates an aura of credibility, providing the students pause to reflect upon their socialized interactions. These…

  8. Exploring the Concept of Sustainable Development through Role-Playing

    ERIC Educational Resources Information Center

    Buchs, Arnaud; Blanchard, Odile

    2011-01-01

    The concept of sustainable development is used in everyday life by the general public, alongside researchers, institutions, and private companies. Nevertheless, its definition is far from being unequivocal. Clarifying the outline of the concept seems necessary. We have created a role-play for this purpose. Our article aims at depicting its main…

  9. Playing with Porn: Greek Children's Explorations in Pornography

    ERIC Educational Resources Information Center

    Tsaliki, Liza

    2011-01-01

    This article draws on the research findings of the Greek Kids Go Online project and the EU Kids Online I network research on children and online technologies in Europe, funded by the European Commission Safer Internet Programme, 2006-2009. It explores the experiences of young people aged between 9 and 17 with pornographic texts online, and…

  10. Playing with Porn: Greek Children's Explorations in Pornography

    ERIC Educational Resources Information Center

    Tsaliki, Liza

    2011-01-01

    This article draws on the research findings of the Greek Kids Go Online project and the EU Kids Online I network research on children and online technologies in Europe, funded by the European Commission Safer Internet Programme, 2006-2009. It explores the experiences of young people aged between 9 and 17 with pornographic texts online, and…

  11. Playful Collaborative Exploration: New Research Practice in Participatory Design

    ERIC Educational Resources Information Center

    Johansson, Martin; Linde, Per

    2005-01-01

    Within the Participatory Design community as well as the Computer Supported Cooperative Work tradition, a lot of effort has been put into the question of letting field studies inform design. In this paper, we describe how game-like approaches can be used as a way of exploring a practice from a design point of view. Thinking of ethnographic…

  12. Transcript: "Can Run, Play on Bikes, Jump the Zoom Slide, and Play on the Swings"--Exploring the Value of Outdoor Play

    ERIC Educational Resources Information Center

    Greenfield, Cheryl

    2004-01-01

    This paper explores some questions surrounding the provision of outdoor play for young children, and challenges adults who share responsibility for "creating future play" to consider not only what we as adults value but also what children value about the outdoor environment. The question is raised as to how the values we hold and the…

  13. Major new foreign exploration plays during 1983-1987

    SciTech Connect

    Emmet, P.A.; Hedberg, J.D.; McIver, N.U.; Tyrrell, W.W. Jr.

    1988-01-01

    About 30 billion bbl of recoverable oil have been found in new foreign plays during the last 5 years; significant gas reserves also were found. Most of the foreign oil discoveries are in Mesozoic sandstone reservoirs onshore, but Marlim, the largest single field with estimated reserves of 2.5 billion bbl, is located offshore in the deep-water part of the Campos basin, Brazil. Approximately 8-10 billion bbl of oil were found in South America, 6 billion in the Near East, 5 billion in western Europe, 5 billion in Africa, 2 billion in Asia (outside the USSR), and 0.5-0.7 billion in Australasia. Some of the giant discoveries include: Cano Limo, Colombia (1983); Alif, North Yemen, and Draugen, Norway (1984); Marlim, Brazil, and Heidrun, Norway (1985); El Furrial, Venezuela (1986); and Musipan-1, Venezuela (1987). Most of these and several smaller discoveries are in new plays or trends.

  14. Limestone compaction: an enigma

    USGS Publications Warehouse

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  15. The influence of human exploration on the microbial community structure and ammonia oxidizing potential of the Su Bentu limestone cave in Sardinia, Italy

    PubMed Central

    Koskinen, Kaisa; Sanna, Laura; D’Angeli, Ilenia M.; De Waele, Jo; Marcia, Paolo; Moissl-Eichinger, Christine; Rettberg, Petra

    2017-01-01

    The bacterial diversity in the Su Bentu Cave in Sardinia was investigated by means of 16S rRNA gene-based analysis. This 15 km long cave, carved in Jurassic limestone, hosts a variety of calcite speleothems, and a long succession of subterranean lakes with mixed granite and carbonate sands. The lower level is occasionally flooded by a rising groundwater level, but with only scarce input of organic remains (leaves and charcoal fragments). On the quiet cave pools there are visible calcite rafts, whereas walls are locally coated with manganese deposits. In the drier upper levels, where organic input is much more subdued, moonmilk—a hydrated calcium-magnesium carbonate speleothem—can be found. Relative humidity approaches 100% and the measured mean annual cave air temperature is 14.8°C. Samples were obtained in 2014 from calcite rafts, moonmilk, manganese oxide deposits and soil (limestone and granite grains). Microclimatic conditions in the cave near the sampling sites, sample properties, physico-chemical parameters of water, and sediment composition were determined. The microbial community of this system is predominately composed of the phyla Proteobacteria, Actinobacteria, Acidobacteria, Nitrospirae, and Firmicutes. Sampling sites near the entrance of the cave and in close proximity of the underground campsite–located 500 meters deep into the cave—revealed the highest diversity as well as the highest number of human associated microorganisms. Two samples obtained in very close proximity of each other near the campsite, indicate that the human impact is localized and is not distributed freely within the system. Analysis of the abundance of bacterial and archaeal amoA genes revealed a far greater abundance of archaeal amoA genes compared to bacterial representatives. The results of this study highlight that human impact is confined to locations that are utilized as campsites and that exploration leaves little microbial trails. Furthermore, we uncovered a

  16. The influence of human exploration on the microbial community structure and ammonia oxidizing potential of the Su Bentu limestone cave in Sardinia, Italy.

    PubMed

    Leuko, Stefan; Koskinen, Kaisa; Sanna, Laura; D'Angeli, Ilenia M; De Waele, Jo; Marcia, Paolo; Moissl-Eichinger, Christine; Rettberg, Petra

    2017-01-01

    The bacterial diversity in the Su Bentu Cave in Sardinia was investigated by means of 16S rRNA gene-based analysis. This 15 km long cave, carved in Jurassic limestone, hosts a variety of calcite speleothems, and a long succession of subterranean lakes with mixed granite and carbonate sands. The lower level is occasionally flooded by a rising groundwater level, but with only scarce input of organic remains (leaves and charcoal fragments). On the quiet cave pools there are visible calcite rafts, whereas walls are locally coated with manganese deposits. In the drier upper levels, where organic input is much more subdued, moonmilk-a hydrated calcium-magnesium carbonate speleothem-can be found. Relative humidity approaches 100% and the measured mean annual cave air temperature is 14.8°C. Samples were obtained in 2014 from calcite rafts, moonmilk, manganese oxide deposits and soil (limestone and granite grains). Microclimatic conditions in the cave near the sampling sites, sample properties, physico-chemical parameters of water, and sediment composition were determined. The microbial community of this system is predominately composed of the phyla Proteobacteria, Actinobacteria, Acidobacteria, Nitrospirae, and Firmicutes. Sampling sites near the entrance of the cave and in close proximity of the underground campsite-located 500 meters deep into the cave-revealed the highest diversity as well as the highest number of human associated microorganisms. Two samples obtained in very close proximity of each other near the campsite, indicate that the human impact is localized and is not distributed freely within the system. Analysis of the abundance of bacterial and archaeal amoA genes revealed a far greater abundance of archaeal amoA genes compared to bacterial representatives. The results of this study highlight that human impact is confined to locations that are utilized as campsites and that exploration leaves little microbial trails. Furthermore, we uncovered a highly

  17. Exploring the Contribution of Play to Social Capital in Institutional Adult Learning Settings

    ERIC Educational Resources Information Center

    Harris, Pauline; Daley, John

    2008-01-01

    This paper explores how play as an educational tool can enhance social capital for adult learners in institutional settings. Framed by conceptualisations of social capital (Putnam 1993, 2000) and play (Melamed 1987, Meares 2005, Vygotsky 1978) and supported by research literature on play in adult learning, our action research in our adult…

  18. Play

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    Designing a game with a serious purpose involves considering the worlds of Reality and Meaning yet it is undeniably impossible to create a game without a third world, one that is specifically concerned with what makes a game a game: the play elements. This third world, the world of people like designers and artists, and disciplines as computer science and game design, I call the world of Play and this level is devoted to it. The level starts off with some of the misperceptions people have of play. Unlike some may think, we play all the time, even when we grow old—this was also very noticeable in designing the game Levee Patroller as the team exhibited very playful behavior at many occasions. From there, I go into the aspects that characterize this world. The first concerns the goal of the game. This relates to the objectives people have to achieve within the game. This is constituted by the second aspect: the gameplay. Taking actions and facing challenges is subsequently constituted by a gameworld, which concerns the third aspect. And all of it is not possible without the fourth and final aspect, the type of technology that creates and facilitates the game. The four aspects together make up a “game concept” and from this world such a concept can be judged on the basis of three closely interrelated criteria: engagement, immersion, and fun.

  19. Exploring Kindergarten Teachers' Views and Roles Regarding Children's Outdoor Play Environments in Oman

    ERIC Educational Resources Information Center

    Ihmeideh, Fathi M.; Al-Qaryouti, Ibrahim A.

    2016-01-01

    The purpose of this study was to explore kindergarten teachers' views and roles regarding outdoor play environments in Omani kindergartens. Thirty kindergarten teachers from 15 private kindergartens were observed and interviewed. The results indicated that teachers recognize the importance of outdoor play in children's development and learning.…

  20. Children's Worlds: An Exploration of Latino Students' Play in Rural New Mexico

    ERIC Educational Resources Information Center

    Ulibarri, Reyna M.

    2016-01-01

    I present an ethnographic study of thirteen nine-year-old, U.S.-born Latino children in rural New Mexico. I employ in-depth individual and group interviews, participant observation, and sand play (a method borrowed from clinical psychology in which children "make a world" in a box of sand) to explore how play interactions represent,…

  1. Children's Worlds: An Exploration of Latino Students' Play in Rural New Mexico

    ERIC Educational Resources Information Center

    Ulibarri, Reyna M.

    2016-01-01

    I present an ethnographic study of thirteen nine-year-old, U.S.-born Latino children in rural New Mexico. I employ in-depth individual and group interviews, participant observation, and sand play (a method borrowed from clinical psychology in which children "make a world" in a box of sand) to explore how play interactions represent,…

  2. Exploring Kindergarten Teachers' Views and Roles Regarding Children's Outdoor Play Environments in Oman

    ERIC Educational Resources Information Center

    Ihmeideh, Fathi M.; Al-Qaryouti, Ibrahim A.

    2016-01-01

    The purpose of this study was to explore kindergarten teachers' views and roles regarding outdoor play environments in Omani kindergartens. Thirty kindergarten teachers from 15 private kindergartens were observed and interviewed. The results indicated that teachers recognize the importance of outdoor play in children's development and learning.…

  3. The Red Hat Society: Exploring the role of play, liminality, and communitas in older women's lives.

    PubMed

    Mackay Yarnal, Careen

    2006-01-01

    There is an extensive literature on play. Yet, the role of play in older adults' lives has received limited attention. Strikingly absent is research on play and older women. Missing from the literature is how older women use play as a liminal context for social interaction and communitas. This is odd because by 2030 one in four American women will be over the age of sixty-five. The primary purpose of this study is to explore the roles of play, liminality, and communitas in older women's lives. The focus is the Red Hat Society, a social group for women over age 50 that fosters play and fun. Using qualitative interviews with focus groups and participant observation of a regional Red Hat Society event, the study highlights some of the strengths and weaknesses of current conceptualizations of play, liminality, and communitas.

  4. Exploring the links between personality traits and motivations to play online games.

    PubMed

    Park, Jowon; Song, Yosep; Teng, Ching-I

    2011-12-01

    The present study explores the links between personality traits and motivations to play online games. We identified the underlying dimensions of motivations to play online games, examined how personality traits predict motivation, and investigated how personality traits predict online gaming behavior (i.e., playing time and preference for game genres). Factor analyses identified five motivational factors: relationships, adventure, escapism, relaxation, and achievement. The regression analyses indicated that two personality traits, extraversion and agreeableness, predicted various motivations; however, personality traits did not affect the playing time and game genre preference.

  5. Exploring types of play in an adapted robotics program for children with disabilities.

    PubMed

    Lindsay, Sally; Lam, Ashley

    2017-03-28

    Play is an important occupation in a child's development. Children with disabilities often have fewer opportunities to engage in meaningful play than typically developing children. The purpose of this study was to explore the types of play (i.e., solitary, parallel and co-operative) within an adapted robotics program for children with disabilities aged 6-8 years. This study draws on detailed observations of each of the six robotics workshops and interviews with 53 participants (21 children, 21 parents and 11 programme staff). Our findings showed that four children engaged in solitary play, where all but one showed signs of moving towards parallel play. Six children demonstrated parallel play during all workshops. The remainder of the children had mixed play types play (solitary, parallel and/or co-operative) throughout the robotics workshops. We observed more parallel and co-operative, and less solitary play as the programme progressed. Ten different children displayed co-operative behaviours throughout the workshops. The interviews highlighted how staff supported children's engagement in the programme. Meanwhile, parents reported on their child's development of play skills. An adapted LEGO(®) robotics program has potential to develop the play skills of children with disabilities in moving from solitary towards more parallel and co-operative play. Implications for rehabilitation Educators and clinicians working with children who have disabilities should consider the potential of LEGO(®) robotics programs for developing their play skills. Clinicians should consider how the extent of their involvement in prompting and facilitating children?s engagement and play within a robotics program may influence their ability to interact with their peers. Educators and clinicians should incorporate both structured and unstructured free-play elements within a robotics program to facilitate children?s social development.

  6. Exploring Early Childhood Teachers' Beliefs and Practices about Preschool Outdoor Play: A Qualitative Study

    ERIC Educational Resources Information Center

    McClintic, Sandra; Petty, Karen

    2015-01-01

    This qualitative case study explored how early childhood teachers' beliefs and practices influence the function of preschool outdoor play. Teachers believed that supervision was paramount. They perceived that the physical design of the outdoor environment posed limitations for planning, preparation, and implementation. Teachers' recollections of…

  7. The Ethanol Project: Exploring Alternative Energy with Role-Play and Writing

    ERIC Educational Resources Information Center

    Winter, Julia

    2013-01-01

    This article describes a project that includes a two-week series of researching, essay writing, and speaking lessons exploring the broader implications of using ethanol as a fuel. The author, a chemistry teacher, describes how she uses a senate hearing discussion of ethanol fuel subsidies as the forum for a role-play. The four components of the…

  8. Play-Based Interview Methods for Exploring Young Children's Perspectives on Inclusion

    ERIC Educational Resources Information Center

    Koller, Donna; San Juan, Valerie

    2015-01-01

    Inclusive education provides learning opportunities for children with disabilities in regular settings with other children. Despite the prevalence of inclusive education, few qualitative studies have adequately explored young children's perspectives on inclusion. This paper reviews the findings of a preliminary qualitative study where play-based…

  9. The Ethanol Project: Exploring Alternative Energy with Role-Play and Writing

    ERIC Educational Resources Information Center

    Winter, Julia

    2013-01-01

    This article describes a project that includes a two-week series of researching, essay writing, and speaking lessons exploring the broader implications of using ethanol as a fuel. The author, a chemistry teacher, describes how she uses a senate hearing discussion of ethanol fuel subsidies as the forum for a role-play. The four components of the…

  10. Exploring Early Childhood Teachers' Beliefs and Practices about Preschool Outdoor Play: A Qualitative Study

    ERIC Educational Resources Information Center

    McClintic, Sandra; Petty, Karen

    2015-01-01

    This qualitative case study explored how early childhood teachers' beliefs and practices influence the function of preschool outdoor play. Teachers believed that supervision was paramount. They perceived that the physical design of the outdoor environment posed limitations for planning, preparation, and implementation. Teachers' recollections of…

  11. Exploring Game Experiences and Game Leadership in Massively Multiplayer Online Role-Playing Games

    ERIC Educational Resources Information Center

    Jang, YeiBeech; Ryu, SeoungHo

    2011-01-01

    This study explored the in-game experiences of massively multiplayer online role-playing game (MMORPG) players focusing on game leadership and offline leadership. MMORPGs have enormous potential to provide gameplayers with rich social experiences through various interactions along with social activities such as joining a game community, team play…

  12. Diagnostic expert systems: Encoding geological knowledge for an exploration play analysis

    SciTech Connect

    Miller, B.M. )

    1993-08-01

    The U.S. Geological Survey is currently exploring the feasibility of applying diagnostic expert systems and knowledge-based acquisition techniques to the geologic analysis of sedimentary basins and petroleum exploration plays. This paper describes a unique approach to the design and application of a rule-based expert system to the analysis of exploration plays, a methodology commonly used to assess petroleum resources in a basin. This technique consists of using various geologic models and Monte Carlo simulation or probabilistic methods for analyzing geologic and reservoir conditions favorable to the occurrence of petroleum resources. Work is in progress to adapt the geologic model used in the play analysis to an expert-systems and knowledge base, the object being to capture the logic and reasoning used to characterize the geologic model and to evaluate the play. Expert systems techniques now being developed are capable of dealing with inexact reasoning or reasoning under uncertainty by incorporating degrees of uncertainty to deal effectively with incomplete, inferred, or interpretive data involved in the knowledge base. The goal of this study is to provide an embedded diagnostic expert-system approach for characterizing the geologic model to expand upon the play-analysis system. Such a system provides the geologist with capabilities to document major basin components, such as stratigraphy, structural geology, and sedimentation, and to analyze the traditional concepts of source, reservoir, and trapping mechanisms. This expert system will assist the geologist in compiling and interpreting the geologic and reservoir engineering data necessary for running the probabilistic methods to calculate the amount of probable petroleum resources within each play. Diagnostic expert-systems technology can provide challenging new tools in knowledge acquisition and data interpretation in petroleum geology.

  13. Deep-Water Resedimented Carbonate Exploration Play Types: Controls and Models

    NASA Astrophysics Data System (ADS)

    Minzoni, M.; Janson, X.; Kerans, C.; Playton, T.; Winefield, P.; Burgess, P. M.

    2016-12-01

    Deepwater resedimented deposits have been described in both modern and ancient carbonate sequences, many with good reservoir potential, for example the giant Cretaceous Poza Rica field in Mexico ( 40 MMBoe), the Mississippian Tangiz field in Kazakhstan, and several fields in the U.S. Permian basin (several Tcf gas). Nevertheless, carbonate slope and basin systems remain poorly understood when compared to their siliciclastic counterparts. Legacy published and unpublished work, combined with a global database of surface and sub-surface examples of resedimented carbonates, has highlighted that downslope resedimentation of carbonate material is in large part controlled by the evolution of the parent platform margin, which in turn is best characterized in terms of various controlling processes such as the carbonate factory type, tectonic setting, eustatic variations, and prevailing wind direction and ocean current patterns. Two generic play types emerge: (i) attached carbonate slope play -developed immediately adjacent to the parent carbonate platform and dominated by rock fall and platform collapse deposits or in situ boundstone; and (ii) detached carbonate slope play - deposited further from the platform margin via channelized turbidity currents and other mass-flow processes. High-rising, steep, bypass platform margins with collapse scars and grain-dominated factories have the highest potential to generate channelized and detached deep-water reservoirs with high initial porosity and permeability. Best reservoirs are aragonitic grainstones transported from the platform into the adjacent basin, and undergoing dissolution in submarine undersaturated water with early formation of secondary porosity to further enhance reservoir properties. Any exploration model aiming at identifying potential resedimented carbonate plays should be based on carbonate platform configurations and factory types favorable for re-sedimentation of large sedimentary bodies and preservation or

  14. Images of Play Experiences through a Child's Lens: An Exploration of Play and Digital Media with Young Children

    ERIC Educational Resources Information Center

    Eckhoff, Angela

    2017-01-01

    This research documents the use of digital media by young children in outdoor play spaces. The research was conducted at a child care center on an urban university campus in the southeastern USA. The research employed a participatory design and used a qualitative, reflexive approach to include the child's voice, ideas, and understandings of their…

  15. Play-fairway analysis for geothermal exploration: Examples from the Great Basin, western USA

    SciTech Connect

    Siler, Drew L; Faulds, James E

    2013-10-27

    Elevated permeability within fault systems provides pathways for circulation of geothermal fluids. Future geothermal development depends on precise and accurate location of such fluid flow pathways in order to both accurately assess geothermal resource potential and increase drilling success rates. The collocation of geologic characteristics that promote permeability in a given geothermal system define the geothermal ‘fairway’, the location(s) where upflow zones are probable and where exploration efforts including drilling should be focused. We define the geothermal fairway as the collocation of 1) fault zones that are ideally oriented for slip or dilation under ambient stress conditions, 2) areas with a high spatial density of fault intersections, and 3) lithologies capable of supporting dense interconnected fracture networks. Areas in which these characteristics are concomitant with both elevated temperature and fluids are probable upflow zones where economic-scale, sustainable temperatures and flow rates are most likely to occur. Employing a variety of surface and subsurface data sets, we test this ‘play-fairway’ exploration methodology on two Great Basin geothermal systems, the actively producing Brady’s geothermal system and a ‘greenfield’ geothermal prospect at Astor Pass, NV. These analyses, based on 3D structural and stratigraphic framework models, reveal subsurface characteristics about each system, well beyond the scope of standard exploration methods. At Brady’s, the geothermal fairways we define correlate well with successful production wells and pinpoint several drilling targets for maintaining or expanding production in the field. In addition, hot-dry wells within the Brady’s geothermal field lie outside our defined geothermal fairways. At Astor Pass, our play-fairway analysis provides for a data-based conceptual model of fluid flow within the geothermal system and indicates several targets for exploration drilling.

  16. Potential degradation mechanisms of stylolitic limestones

    NASA Astrophysics Data System (ADS)

    Aly, Nevin; Török, Ákos; Aguilar Sanchez, Asel Maria; Wangler, Timothy

    2017-04-01

    Stylolites are irregular rough surfaces formed due to the pressure-solution process and commonly developed in carbonate stones. Stylolite formation is usually accompanied by the accumulation of insoluble residues i.e. organic matter, oxides and clays on the stylolitic surfaces. The amount and the type of these clays may play a significant role in the deterioration of the host stone. This study presents the characterization of various stylolitic limestones containing different amounts of clays and used extensively as building cladding and decorative stones in Israel and in Hungary. The first case study focuses on two lithotypes from Israel, both of them are biocalcirudite-calcarenite with high amount of bioclasts. Abundance of open stylolites filled partially with organic matter and minor amounts of clays exist in the first lithotype with cream colour. The second lithotype has grey colour and contains organic matter and pyrite dispersed throughout the stone and more concentrated within the stylolites along with clay and dolomite crystal. Both lithotypes exhibit signs of decay just after a few years of exposure. The first studied Hungarian limestone is a red Jurassic carbonate (ammonitico rosso type) that was formed in pelagic marine environment. This wackestone contains abundant pelagic microfossils. The limestone has been used from Roman period in Central Europe in Hungary, Romania and Poland. The stylolites are seen as darker bedding parallel seams containing minor amounts of clay and hematite. Small amount of clay is also found in isolated nodules. The second Hungarian lithotype is also a Jurassic limestone which contains less clay than the previous one. This yellowish-white limestone is strongly cemented and contains red intersecting stylolites that do not follow the bedding planes or stratification. The main aim of this study is to understand and evaluate the damage mechanism of different stylolitic limestones. Samples were exposed to multiple thermal and wet

  17. Exploring the Impact of Role-Playing on Peer Feedback in an Online Case-Based Learning Activity

    ERIC Educational Resources Information Center

    Ching, Yu-Hui

    2014-01-01

    This study explored the impact of role-playing on the quality of peer feedback and learners' perception of this strategy in a case-based learning activity with VoiceThread in an online course. The findings revealed potential positive impact of role-playing on learners' generation of constructive feedback as role-playing was associated with higher…

  18. Playing with Shadows--Playing with Words: Exploring Teachers' Ownership through Poetic Inquiry in a Norwegian-Nepalese Preschool Teacher Education Project

    ERIC Educational Resources Information Center

    Mjanger, Ruth

    2014-01-01

    This article explores the use of poetic inquiry in a transnational competence-building Shadow Play Project. Based on journals from four Nepalese preschool teacher educators, I present and interpret examples of data poems that portray the teachers' experiences of ownership in the project. My discussion intends to make explicit some aspects of the…

  19. Drug Use as Boundary Play: A Qualitative Exploration of Gay Circuit Parties

    PubMed Central

    O'Byrne, Patrick; Holmes, Dave

    2011-01-01

    Research findings have revealed that gay circuit parties may be locations that are disproportionately responsible for the increasing rates of many STIs/HIV among gay/bisexual men. Theories have been put forth that this may be the case because circuit parties are locales of prevalent drug use and unsafe sex. To explore the relationship between these two phenomena, in-depth qualitative interviews were undertaken with 17 men who (1) have sex with other men, (2) attended gay circuit parties in Montréal, Canada, in 2007. These revealed that drugs (including alcohol) were used intentionally to engage in unsafe sex, and then to justify this behavior after the fact. This process we called boundary play. PMID:21692603

  20. Natural fracture characterization: A key to success in an exploration play, Converse County, Wyoming

    SciTech Connect

    Parks, S.L.; Gale, M.S.; Bradley, P.J.; Mount, V.S.

    1996-06-01

    Numerous vertical wells drilled in the southern Powder River basin have encountered fractured, tight, overpressured, Cretaceous hydrocarbon reservoirs. These reservoirs demonstrate enhanced productivity and ultimate recovery with little to no water production. Effective exploration and development of these reservoirs includes a systematic approach to characterization and prediction of the fracture system. Surface mapping within Cretaceous units along the southern and western margins of the basin revealed multiple fracture sets related to both regional and local tectonic events. A pre-Laramide regional fracture set oriented at approximately N70{degrees}E is dominant over the mapped 500 square mile area. This set displays a consistent frequency, direction, height. and morphology both in the surface and subsurface. Fractures in early Tertiary rocks within the basin are unidirectionally oriented along a WNW azimuth, a direction also found in the Cretaceous units. Vaster Resources, Inc. is actively exploring fractured reservoirs in the Powder River basin with horizontal wells targeting the Niobrara and Frontier formations. Integration of the detailed surface outcrop studies with regional cross-sections, Landsat lineament analysis, FMS log data, 2D multicomponent/multisource shear wave seismic, and borehole breakouts (to determine present day stress) have been used to successfully predict the orientation, frequency, and degree of openness of the subsurface fracture system. The consistency of the fracture system and its positive impact on reservoir productivity significantly enhance the prospectiveness of Cretaceous plays throughout the southern Powder River basin.

  1. CREATING A GEOLOGIC PLAY BOOK FOR TRENTON-BLACK RIVER APPALACHIAN BASIN EXPLORATION

    SciTech Connect

    Douglas G. Patchen; James Drahovzal; Larry Wickstrom; Taury Smith; Chris Laughery; Katharine Lee Avary

    2004-04-01

    Private- and public-sector stakeholders formed the new ''Trenton-Black River Appalachian Basin Exploration Consortium'' and began a two-year research effort that will lead to a play book for Trenton-Black River exploration throughout the Appalachian basin. The final membership of the Consortium includes 17 gas exploration companies and 6 research team members, including the state geological surveys in Kentucky, Ohio, Pennsylvania and West Virginia, the New York State Museum Institute and West Virginia University. Seven integrated research tasks are being conducted by basin-wide research teams organized from this large pool of experienced professionals. More than 3400 miles of Appalachian basin digital seismic data have been quality checked. In addition, inquiries have been made regarding the availability of additional seismic data from government and industry partners in the consortium. Interpretations of the seismic data have begun. Error checking is being performed by mapping the time to various prominent reflecting horizons, and analyzing for any anomalies. A regional geological velocity model is being created to make time-to-depth conversions. Members of the stratigraphy task team compiled a generalized, basin-wide correlation chart, began the process of scanning geophysical logs and laid out lines for 16 regional cross sections. Two preliminary cross sections were constructed, a database of all available Trenton-Black River cores was created, and a basin-wide map showing these core locations was produced. Two cores were examined, described and photographed in detail, and were correlated to the network of geophysical logs. Members of the petrology team began the process of determining the original distribution of porous and permeable facies within a sequence stratigraphic framework. A detailed sedimentologic and petrographic study of the Union Furnace road cut in central Pennsylvania was completed. This effort will facilitate the calibration of subsurface core

  2. Petroleum exploration plays of the onshore Douala/Kribi Campo of Cameroon, West Africa

    SciTech Connect

    Seme Abomo, R.

    1996-08-01

    Generally, rifting and drifting phases characterize the Douala/Kribi Campo Formation. The rifting phase resulted from a progressive northward plate tectonic evolution, which extended from Late Jurassic to Neocomian-Turonian time, involving both an extensional process and strike-slip movements along fracture zones. The drifting phase was established during the Albian period, with the first marine incursion in the basin. During this phase, sedimentation was controlled by such factors as sea level variations, drainage systems and climate. Consequently, the onshore sector of the Douala/Kribi-Campo Basin can be subdivided into two major areas with different petroleum exploration plays. The southern area in which the rifting phase has thick Albo-Aptian sediments of terrigenous and clastics nature. These were deposited in coalescing fan deltas, locations of which were controlled by collapsed and tilted blocks. Trangressive deposits of the drifting phase overlie the erosional surface. In the northern area, the rifting phase consists of a system of horsts and grabens of Aptian time. The drifting phase consists of shelf sandstones and Upper Cretaceous turbiditic deposits.

  3. Sandboxes, Loose Parts, and Playground Equipment: A Descriptive Exploration of Outdoor Play Environments

    ERIC Educational Resources Information Center

    Olsen, Heather; Smith, Brandy

    2017-01-01

    The purpose of the study was to examine outdoor environments to understand whether or not young children had access to play materials and loose parts to enhance their playful experiences. This study sought to gather the availability of SAFE and quality play opportunities in early childhood outdoor environments. The study took place in one state of…

  4. Exploring the Potential of Role Play in Higher Education: Development of a Typology and Teacher Guidelines

    ERIC Educational Resources Information Center

    Rao, Deepa; Stupans, Ieva

    2012-01-01

    Role-play, in which learners act out roles in case scenarios, appears to be used across a broad range of discipline areas to address learning across the cognitive, psychomotor and affective domains. This paper describes the development of a prospective typology of role-play learning opportunities derived from role-play scenarios used at one large…

  5. Exploring Hispanic Teacher Candidates' Beliefs about the Value of Play in Children's Learning and Development

    ERIC Educational Resources Information Center

    Cortez-Castro, Diana H.

    2015-01-01

    Play has been globally recognized as valuable to children's learning and development (Frost et al., 2012). The value of play is acknowledged as a developmentally appropriate practice in part because it fosters cognitive, physical, emotional, and social benefits to children. Play is also known as a human right that should be protected. However, in…

  6. Sticky to Dry; Red to Purple: Exploring Transformation with Play Dough.

    ERIC Educational Resources Information Center

    Goldhaber, Jeanne

    1992-01-01

    Play dough is the perfect medium for creating, observing, and thinking about change. Whether the use of play dough is seen as play or a demonstration of physics, through its use children learn about transformations of consistency, color, and identity; and teachers observe how young children learn. (LB)

  7. Sticky to Dry; Red to Purple: Exploring Transformation with Play Dough.

    ERIC Educational Resources Information Center

    Goldhaber, Jeanne

    1992-01-01

    Play dough is the perfect medium for creating, observing, and thinking about change. Whether the use of play dough is seen as play or a demonstration of physics, through its use children learn about transformations of consistency, color, and identity; and teachers observe how young children learn. (LB)

  8. CREATING A GEOLOGIC PLAY BOOK FOR TRENTON-BLACK RIVER APPALACHIAN BASIN EXPLORATION

    SciTech Connect

    Douglas G. Patchen; Chris Laughrey; Jaime Kostelnik; James Drahovzal; John B. Hickman; Paul D. Lake; John Bocan; Larry Wickstrom; Taury Smith; Katharine Lee Avary

    2004-10-01

    The ''Trenton-Black River Appalachian Basin Exploration Consortium'' has reached the mid-point in a two-year research effort to produce a play book for Trenton-Black River exploration. The final membership of the Consortium includes 17 exploration and production companies and 6 research team members, including four state geological surveys, the New York State Museum Institute and West Virginia University. Seven integrated research tasks and one administrative and technology transfer task are being conducted basin-wide by research teams organized from this large pool of experienced professionals. All seismic data available to the consortium have been examined at least once. Synthetic seismograms constructed for specific wells have enabled researchers to correlate the tops of 10 stratigraphic units determined from well logs to seismic profiles in New York and Pennsylvania. In addition, three surfaces in that area have been depth converted, gridded and mapped. In the Kentucky-Ohio-West Virginia portion of the study area, a velocity model has been developed to help constrain time-to-depth conversions. Fifteen formation tops have been identified on seismic in that area. Preliminary conclusions based on the available seismic data do not support the extension of the Rome Trough into New York state. Members of the stratigraphy task team measured, described and photographed numerous cores from throughout the basin, and tied these data back to their network of geophysical log cross sections. Geophysical logs were scanned in raster files for use in detailed well examination and construction of cross sections. Logs on these cross sections that are only in raster format are being converted to vector format for final cross section displays. The petrology team measured and sampled one classic outcrop in Pennsylvania and ten cores in four states. More than 600 thin sections were prepared from samples in those four states. A seven-step procedure is being used to analyze all thin

  9. Influence of pore system characteristics on limestone vulnerability: a laboratory study

    NASA Astrophysics Data System (ADS)

    Cultrone, G.; Russo, L. G.; Calabrò, C.; Uroševič, M.; Pezzino, A.

    2008-05-01

    Hyblean limestone of Oligo-Miocene age was widely used as a construction material in the architectural heritage of Eastern Sicily (Italy). Among them, the so-called Pietra Bianca di Melilli (Melilli limestone) and Calcare di Siracusa (Syracuse limestone) were prized for their attractive appearance, ease of quarrying, and workability. Syracuse limestone shows general weathering, whereas Melilli limestone is better preserved, and only differential erosion or superficial exfoliation can be detected in monuments. The cause of the different behavior of these two limestones was investigated from the petrographic and petrophysical points of view. The saturation coefficient is higher in Melilli limestone, and ultrasound measurements indicate that it is less compact than Syracuse limestone, so that Melilli limestone could deteriorate more easily than Syracuse limestone. However, pore interconnections and the size of very small pores play the main role in the durability of both materials. The “irregularity” of the Syracuse pore system and its greater number of micropores hinder water flow through the exterior, promote stress in pore structure, and favor the development of scaling, as confirmed by salt crystallization tests. In Melilli limestone, the low concentration of micropores and fast water evaporation allow solutions to reach the surface more easily, resulting in less damaging efflorescence.

  10. Exploring Natural Pedagogy in Play with Preschoolers: Cues Parents Use and Relations among Them

    ERIC Educational Resources Information Center

    Sage, Kara; Baldwin, Dare

    2012-01-01

    Recent developmental work demonstrates a range of effects of pedagogical cues on childhood learning. The present work investigates natural pedagogy in informal parent-child play. Preschool-aged children participated in free play and a toy task with a parent in addition to a toy task with an experimenter. Sessions were extensively coded for use of…

  11. Exploring Natural Pedagogy in Play with Preschoolers: Cues Parents Use and Relations among Them

    ERIC Educational Resources Information Center

    Sage, Kara; Baldwin, Dare

    2012-01-01

    Recent developmental work demonstrates a range of effects of pedagogical cues on childhood learning. The present work investigates natural pedagogy in informal parent-child play. Preschool-aged children participated in free play and a toy task with a parent in addition to a toy task with an experimenter. Sessions were extensively coded for use of…

  12. Outdoor Play and Play Equipment.

    ERIC Educational Resources Information Center

    Naylor, Heather

    1985-01-01

    Discusses aspects of the play environment and its effect on children's play behavior. Indoor and outdoor play spaces are considered along with factors affecting the use of outdoor environments for play. Children's preferences for different outdoor play environments and for various play structures are explored. Guides for choosing play equipment…

  13. Outdoor Play and Play Equipment.

    ERIC Educational Resources Information Center

    Naylor, Heather

    1985-01-01

    Discusses aspects of the play environment and its effect on children's play behavior. Indoor and outdoor play spaces are considered along with factors affecting the use of outdoor environments for play. Children's preferences for different outdoor play environments and for various play structures are explored. Guides for choosing play equipment…

  14. Exploring the Game of "Julirde": A Mathematical-Educational Game Played by Fulbe Children in Cameroon.

    ERIC Educational Resources Information Center

    Gerdes, Paulus

    2001-01-01

    Presents an educational mathematical activity from Africa. Shows how one child explored the game of Julirde, a game of the mosque emphasizing problem solving and symmetry. Offers several suggestions for exploring the game from the central African country of Cameroon in the elementary school mathematics classroom. (ASK)

  15. Exploring the Use of Role Play in a School-Based Programme to Reduce Teenage Pregnancy

    ERIC Educational Resources Information Center

    Taylor, Myra; Diamini, Nthabiseng; Khanyile, Zama; Mpanza, Lloyd; Sathiparsad, Reshma

    2012-01-01

    Can the use of a method such as role play help reduce sexual risk behaviour among KwaZulu-Natal learners? A study was undertaken of the use of role plays by Grade 8 learners, at eight urban and rural KwaZulu-Natal high schools, as part of a programme to reduce the prevalence of teenage pregnancy. Within the framework of Bandura's Social Cognitive…

  16. A Metagenomic Survey of Limestone Hill in Taiwan

    NASA Astrophysics Data System (ADS)

    Hsu, Y. W.; Li, K. Y.; Chen, Y. W.; Huang, T. Y.; Chen, W. J.; Shih, Y. J.; Chen, J. S.; Fan, C. W.; Hsu, B. M.

    2016-12-01

    The limestone of Narro-Sky in Tainliao, Taiwan is of Pleistocene reef limestones interbedded in clastic layers that covered the Takangshan anticlines. Understanding how microbial relative abundance was changed in response to changes of environmental factors may contribute to better comprehension of roles that microorganisms play in altering the landscape structures. In this study, microorganisms growing on the wall of limestone, in the water dripping from the limestone wall and of soil underneath the wall were collected from different locations where the environmental factors such as daytime illumination, humidity, or pH are different. Next generation sequencing (NGS) was carried out to examine the compositions and richness of microbial community. The metagenomics were clustered into operational taxonomic units (OTUs) to analyze relative abundance, diversities and principal coordinates analysis (PCoA). Our results showed the soil sample has the highest alpha diversity while water sample has the lowest. Four major phyla, which are Proteobacteria, Acidobacteria, Actinobacteria, and Cyanobacteria, account for 80 % of total microbial biomass in all groups. Cyanobacteria were found most abundantly in limestone wall instead of water or soil of weathering limestone. The PCoA dimensional patterns of each phylum showed a trace of microbial community dynamic changes, which might be affected by environmental factors. This study provides the insights to understand how environmental factors worked together with microbial community to shape landscape structures.

  17. Scaling on a limestone flooring

    NASA Astrophysics Data System (ADS)

    Carmona-Quiroga, P. M.; Blanco-Varela, M. T.; Martínez-Ramírez, S.

    2012-04-01

    Natural stone can be use on nearly every surface, inside and outside buildings, but decay is more commonly reported from the ones exposed to outdoor aggressively conditions. This study instead, is an example of limestone weathering of uncertain origin in the interior of a residential building. The stone, used as flooring, started to exhibit loss of material in the form of scaling. These damages were observed before the building, localized in the South of Spain (Málaga), was inhabited. Moreover, according to the company the limestone satisfies the following European standards UNE-EN 1341: 2002, UNE-EN 1343: 2003; UNE-EN 12058: 2004 for floorings. Under these circumstances the main objective of this study was to assess the causes of this phenomenon. For this reason the composition of the mortar was determined and the stone was characterized from a mineralogical and petrological point of view. The last material, which is a fossiliferous limestone from Egypt with natural fissure lines, is mainly composed of calcite, being quartz, kaolinite and apatite minor phases. Moreover, under different spectroscopic and microscopic techniques (FTIR, micro-Raman, SEM-EDX, etc) samples of the weathered, taken directly from the buildings, and unweathered limestone tiles were examined and a new mineralogical phase, trona, was identified at scaled areas which are connected with the natural veins of the stone. In fact, through BSE-mapping the presence of sodium has been detected in these veins. This soluble sodium carbonate would was dissolved in the natural waters from which limestone was precipitated and would migrate with the ascendant capilar humidity and crystallized near the surface of the stone starting the scaling phenomenon which in historic masonry could be very damaging. Therefore, the weathering of the limestone would be related with the hygroscopic behaviour of this salt, but not with the constructive methods used. This makes the limestone unable to be used on restoration

  18. Exploring children's seasonal play to promote active lifestyles in Auckland, New Zealand.

    PubMed

    Ergler, Christina R; Kearns, Robin; Witten, Karen

    2016-09-01

    Studies of seasonal barriers for outdoor activities seldom view families' play practices as grounded in the everyday experience of the natural elements. This paper brings 20 families' mundane outdoor play experiences in Auckland's temperate climate to the fore. Through drawings and interviews, families residing in both suburban detached houses and central city apartments revealed locally constituted beliefs about appropriate play spaces (e.g. garden, park). While the majority of participants retreated to indoor activities during winter, some children and their parents viewed the outdoors as the only opportunity for 'real fun'. We advocate the importance of a better understanding of children's seasonal outdoor play. In particular, we argue that in order to promote year-round healthy levels of outdoor activities it is necessary to understand variations in societal, neighbourhood and family values attributed to outdoor activities. Further, to develop a more nuanced understanding of the locational complexities of outdoor play it is important to understand the meanings of, and practices associated with, seasonal and weather conditions in different international locations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Servant Leadership: How does NASA Serve the Interests of Humankind in Aerospace Exploration and the Role STEM Plays in it?

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.

    2013-01-01

    This presentation provides a description of technology efforts illustrative of NASA Glenn Research Center Core competencies and which exemplifies how NASA serves the interest of humankind in aerospace exploration. Examples are provided as talking points to illustrate the role that career paths in science, technology, engineering and mathematics (STEM) plays in the aforementioned endeavor.

  20. Exploring the Role Teacher Perceptions Play in the Underrepresentation of Culturally and Linguistically Diverse Students in Gifted Programming

    ERIC Educational Resources Information Center

    Allen, Jennifer K.

    2017-01-01

    This qualitative study explored the role teacher perceptions play in the underrepresentation of culturally and linguistically diverse (CLD) students in gifted programming. Purposeful sampling was used to select six interview participants with at least 5 years of teaching experience. Each participant took part in two semistructured interviews over…

  1. Keeping It Real: Exploring an Interdisciplinary Breaking Bad News Role-Play as an Integrative Learning Opportunity

    ERIC Educational Resources Information Center

    Sweeney, Catherine; O'Sullivan, Eleanor; McCarthy, Marian

    2015-01-01

    Palliative care is a complex area of healthcare best delivered by an interdisciplinary team approach. Breaking bad news is an inherent part of caring for people with life-limiting conditions. This study aims to explore an interdisciplinary breaking bad news role-play in a palliative care module. Participants were undergraduate medical and nursing…

  2. Math Academy: Play Ball! Explorations in Data Analysis & Statistics. Book 3: Supplemental Math Materials for Grades 3-8

    ERIC Educational Resources Information Center

    Rimbey, Kimberly

    2008-01-01

    Created by teachers for teachers, the Math Academy tools and activities included in this booklet were designed to create hands-on activities and a fun learning environment for the teaching of mathematics to the students. This booklet contains the "Math Academy--Play Ball! Explorations in Data Analysis & Statistics," which teachers can use to…

  3. An Ecological Exploration of Young Children's Digital Play: Framing Children's Social Experiences with Technologies in Early Childhood

    ERIC Educational Resources Information Center

    Arnott, Lorna

    2016-01-01

    This article outlines an ecological framework for describing children's social experiences during digital play. It presents evidence from a study that explored how 3- to 5-year-old children negotiated their social experiences as they used technologies in preschool. Utilising a systematic and iterative cycle of data collection and analysis,…

  4. An Ecological Exploration of Young Children's Digital Play: Framing Children's Social Experiences with Technologies in Early Childhood

    ERIC Educational Resources Information Center

    Arnott, Lorna

    2016-01-01

    This article outlines an ecological framework for describing children's social experiences during digital play. It presents evidence from a study that explored how 3- to 5-year-old children negotiated their social experiences as they used technologies in preschool. Utilising a systematic and iterative cycle of data collection and analysis,…

  5. Power-Up: Exploration and Play in a Novel Modified Ride-On Car for Standing.

    PubMed

    Logan, Samuel W; Lobo, Michele A; Feldner, Heather A; Schreiber, Melynda; MacDonald, Megan; Winden, Haylee N; Stoner, Tracy; Galloway, James Cole

    2017-01-01

    The purpose of this study was to compare the physical activity and play behaviors of preschoolers without disabilities and 1 preschooler with physical disability. Participants were 42 preschoolers without disabilities and 1 preschooler with physical disability (Child A). Child A used either crutches or a modified ride-on car while in the gymnasium and playground. In the gymnasium, Child A engaged in less solitary play and more parallel play while using the modified ride-on car compared with crutches. On the playground, Child A engaged in more sitting and less running while using crutches compared with preschoolers without disabilities. On the playground, Child A engaged in more peer interaction and less teacher interaction when using the modified ride-on car compared with crutches. For children with disabilities who may use assistive devices, clinicians, families, and teachers are encouraged to embrace a "right device, right time, right place" approach.

  6. Role Play in Blended Learning: A Case Study Exploring the Impact of Story and Other Elements

    ERIC Educational Resources Information Center

    Dracup, Mary

    2008-01-01

    Role play is an increasingly popular technique in tertiary education, being student centred, constructivist and suitable for a range of subject areas. The choice of formats is wide open, with options ranging from the traditional face to face performance through to multi-user online computer games. Some teachers prefer to take advantage of features…

  7. Play as a Resource for Children Facing Adversity: An Exploration of Indicative Case Studies

    ERIC Educational Resources Information Center

    Fearn, Maggie; Howard, Justine

    2012-01-01

    In this paper, we suggest that the ability and opportunity to play affords children a natural resource to meet intellectual and emotional challenge. Analysis of case studies focusing on interventions with children caught in the bombing of Beirut, children abandoned to the state system in Romania, and the street children in Rio de Janeiro and Cali…

  8. More than Child's Play: North Carolina Professor Explores the History of Dolls and Their Sociological Impact

    ERIC Educational Resources Information Center

    Yates, Eleanor Lee

    2004-01-01

    For Dr. Sabrina Thomas, dolls are not just child's play. In fact, they are the subject of her research, which recently landed her a $40,000 grant from the National Endowment for the Humanities. Thomas, an assistant professor of family and consumer sciences at North Carolina Central University, was awarded the grant to write a book on the history…

  9. Trading Spaces: An Educator's Ethnographic Exploration of Adolescents' Digital Role-Play

    ERIC Educational Resources Information Center

    Haynes-Moore, Stacy

    2015-01-01

    In this work, the author examines a digital role-play in which participants composed an alternate version of "The Hunger Games" (Collins, 2008). Participants imagined characters and posted more than 400 scenes in the online collaboration. The author draws upon ethnographic methods (Merriam, 2009) to describe her participant-observer…

  10. Play as a Resource for Children Facing Adversity: An Exploration of Indicative Case Studies

    ERIC Educational Resources Information Center

    Fearn, Maggie; Howard, Justine

    2012-01-01

    In this paper, we suggest that the ability and opportunity to play affords children a natural resource to meet intellectual and emotional challenge. Analysis of case studies focusing on interventions with children caught in the bombing of Beirut, children abandoned to the state system in Romania, and the street children in Rio de Janeiro and Cali…

  11. Exploring Performativity and Resistance in Qualitative Research Interviews: A Play in Four Acts

    ERIC Educational Resources Information Center

    Beaunae, Cathrine; Wu, Chiu-Hui; Koro-Ljungberg, Mirka

    2011-01-01

    This play describes how the authors become aware of the complexities of resistance and performativity in the qualitative interview process. It also illustrates how this awareness and subsequent acquisition of knowledge changed and informed the way they viewed qualitative research interviewing. More specifically, performativity is put into work in…

  12. More than Child's Play: North Carolina Professor Explores the History of Dolls and Their Sociological Impact

    ERIC Educational Resources Information Center

    Yates, Eleanor Lee

    2004-01-01

    For Dr. Sabrina Thomas, dolls are not just child's play. In fact, they are the subject of her research, which recently landed her a $40,000 grant from the National Endowment for the Humanities. Thomas, an assistant professor of family and consumer sciences at North Carolina Central University, was awarded the grant to write a book on the history…

  13. Playing with Heutagogy: Exploring Strategies to Empower Mature Learners in Higher Education

    ERIC Educational Resources Information Center

    Canning, Natalie

    2010-01-01

    Mature learners often invest a great deal of emotional energy in starting a higher education qualification. They have complex needs which are often less to do with their ability to learn and more to do with aspects of confidence and levels of self-belief about achieving or feeling "good enough" to participate. This article explores the…

  14. Why Do We Play the Games? Exploring Institutional and Political Motivations

    ERIC Educational Resources Information Center

    Bardon, Thibaut; Josserand, Emmanuel

    2009-01-01

    Purpose: The purpose of this paper is to explore why digital games based learning (DGBL) is spreading rapidly in all educational settings, when the literature does not provide clear empirical evidence of the pedagogical benefits. The paper seeks to understand why DGBL is constantly developing despite this lack of consensus about the learning…

  15. Exploring Literacy Teachers' Self-Efficacy Beliefs: Potential Sources at Play

    ERIC Educational Resources Information Center

    Tschannen-Moran, Megan; Johnson, Denise

    2011-01-01

    This study explored the antecedents of self-efficacy beliefs for literacy instruction and the relationship of these beliefs to self-efficacy for teaching in general. Factor analysis demonstrated construct validity of the measure of TSELI developed. Moderate correlations between TSELI and the more general TSES suggest that while there is some…

  16. Why Do We Play the Games? Exploring Institutional and Political Motivations

    ERIC Educational Resources Information Center

    Bardon, Thibaut; Josserand, Emmanuel

    2009-01-01

    Purpose: The purpose of this paper is to explore why digital games based learning (DGBL) is spreading rapidly in all educational settings, when the literature does not provide clear empirical evidence of the pedagogical benefits. The paper seeks to understand why DGBL is constantly developing despite this lack of consensus about the learning…

  17. Using forum play to prevent abuse in health care organizations: A qualitative study exploring potentials and limitations for learning.

    PubMed

    Brüggemann, A Jelmer; Persson, Alma

    2016-01-01

    Abuse in health care organizations is a pressing issue for caregivers. Forum play, a participatory theater model, has been used among health care staff to learn about and work against abuse. This small-scale qualitative study aims to explore how forum play participants experience the potentials and limitations of forum play as an educational model for continued professional learning at a hospital clinic. Fifteen of 41 members of staff of a Swedish nephrology clinic, primarily nurses, voluntarily participated in either one or two forum play workshops, where they shared experiences and together practiced working against abuse in everyday health care situations. Interviews were conducted after the workshops with 14 of the participants, where they were asked to reflect on their own and others' participation or nonparticipation, and changes in their individual and collective understanding of abuse in health care. Before the workshops, the informants were either hesitant or very enthusiastic toward the drama-oriented form of learning. Afterward, they all agreed that forum play was a very effective way of individual as well as collective learning about abuse in health care. However, they saw little effect on their work at the clinic, primarily understood as a consequence of the fact that many of their colleagues did not take part in the workshops. This study, based on the analysis of forum play efforts at a single hospital clinic, suggests that forum play can be an innovative educational model that creates a space for reflection and learning in health care practices. It might be especially fruitful when a sensitive topic, such as abuse in health care, is the target of change. However, for the effects to reach beyond individual insights and a shared understanding among a small group of participants, strategies to include all members of staff need to be explored.

  18. Structural studies in limestone sulfidation

    SciTech Connect

    Fenouil, Laurent A.

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900°C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO3 to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO3 calcination point (899°C at 1.03 bar CO2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900°C if CO2 is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO3 grains that greatly hinders more H2S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H2S through the CaS layer, possibly by S2- ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  19. Studying friction while playing the violin: exploring the stick-slip phenomenon.

    PubMed

    Casado, Santiago

    2017-01-01

    Controlling the stick-slip friction phenomenon is of major importance for many familiar situations. This effect originates from the periodic rupture of junctions created between two rubbing surfaces due to the increasing shear stress at the interface. It is ultimately responsible for the behavior of many braking systems, earthquakes, and unpleasant squeaky sounds caused by the scratching of two surfaces. In the case of a musical bow-stringed instrument, stick-slip is controlled in order to provide well-tuned notes at different intensities. A trained ear is able to distinguish slight sound variations caused by small friction differences. Hence, a violin can be regarded as a perfect benchmark to explore the stick-slip effect at the mesoscale. Two violin bow hairs were studied, a natural horse tail used in a professional philharmonic orchestra, and a synthetic one used with a violin for beginners. Atomic force microscopy characterization revealed clear differences when comparing the surfaces of both bow hairs, suggesting that a structure having peaks and a roughness similar to that of the string to which both bow hairs rubbed permits a better control of the stick-slip phenomenon.

  20. Studying friction while playing the violin: exploring the stick–slip phenomenon

    PubMed Central

    2017-01-01

    Controlling the stick–slip friction phenomenon is of major importance for many familiar situations. This effect originates from the periodic rupture of junctions created between two rubbing surfaces due to the increasing shear stress at the interface. It is ultimately responsible for the behavior of many braking systems, earthquakes, and unpleasant squeaky sounds caused by the scratching of two surfaces. In the case of a musical bow-stringed instrument, stick–slip is controlled in order to provide well-tuned notes at different intensities. A trained ear is able to distinguish slight sound variations caused by small friction differences. Hence, a violin can be regarded as a perfect benchmark to explore the stick–slip effect at the mesoscale. Two violin bow hairs were studied, a natural horse tail used in a professional philharmonic orchestra, and a synthetic one used with a violin for beginners. Atomic force microscopy characterization revealed clear differences when comparing the surfaces of both bow hairs, suggesting that a structure having peaks and a roughness similar to that of the string to which both bow hairs rubbed permits a better control of the stick–slip phenomenon. PMID:28243552

  1. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTACTORS

    EPA Science Inventory

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. The purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. Th...

  2. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTACTORS

    EPA Science Inventory

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. The purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. Th...

  3. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially (not less than 94 percent) of calcium carbonate (CaCO3) and is prepared by the crushing, grinding,...

  4. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially (not less than 94 percent) of calcium carbonate (CaCO3) and is prepared by the crushing, grinding, and...

  5. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially (not less than 94 percent) of calcium carbonate (CaCO3) and is prepared by the crushing, grinding, and...

  6. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially (not less than 94 percent) of calcium carbonate (CaCO3) and is prepared by the crushing, grinding, and...

  7. Alaska research natural areas: 2. Limestone jags.

    Treesearch

    G.P. Juday

    1989-01-01

    The 2083-hectare Limestone Jags Research Natural Area in the White Mountains National Recreation Area of central Alaska contains old limestone terrain features––caves, natural bridges, disappearing streams, and cold springs in a subarctic setting. A limestone dissolution joint-type cave in the area is one of the largest reported in high-latitude North America. A...

  8. Limestone weathering rates accelerated by micron-scale grain detachment

    NASA Astrophysics Data System (ADS)

    Emmanuel, S.; Levenson, Y.

    2014-12-01

    The weathering rates of carbonate rocks is often thought to be controlled by chemical dissolution, although some studies have suggested that mechanical erosion could also play an important role. Quantifying the rates of the different processes has proved challenging due to the high degree of variability encountered in both field and lab settings. To determine the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Weathering rates in fine-grained micritic limestone blocks are up to 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these higher reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained rocks in many carbonate terrains.

  9. Using Cross-Cultural, Intergenerational Play Narratives to Explore Issues of Social Justice and Equity in Discourse on Children's Play

    ERIC Educational Resources Information Center

    Shimpi, Priya Mariana; Nicholson, Julie

    2014-01-01

    Discussion of children's play in international and diverse communities requires careful consideration of social, cultural and political contexts impacting children's lives, as well as recognition of the complexities revealed when these variables are identified and analysed. Using diverse conceptual frameworks represented in the research…

  10. Using Cross-Cultural, Intergenerational Play Narratives to Explore Issues of Social Justice and Equity in Discourse on Children's Play

    ERIC Educational Resources Information Center

    Shimpi, Priya Mariana; Nicholson, Julie

    2014-01-01

    Discussion of children's play in international and diverse communities requires careful consideration of social, cultural and political contexts impacting children's lives, as well as recognition of the complexities revealed when these variables are identified and analysed. Using diverse conceptual frameworks represented in the research…

  11. Meteoric stabilization and preservation of limestone within late Proterozoic Beck Spring Dolomite of eastern California

    SciTech Connect

    Zempolich, W.G.; Wilkinson, B.H.; Lohmann, K.C.

    1989-04-01

    Petrographic and geochemical study of limestone, silicified carbonate, and dolostone indicates that meteoric diagenetic processes and paleogeographic position played important roles in the stabilization and preservation of limestone within the pervasively dolomitized Beck Spring Dolomite. The authors conclude that Beck Spring marine cement allochems precipitated as aragonite and high-magnesium calcite. In the vicinity of Saratoga Spring, these metastable mineralogies were dissolved, eroded, stabilized to calcite, and replaced by silica through interaction with meteoric waters. Early stabilization of limestone components along the margin of the Amargosa basin apparently decreased susceptibility to subsequent dolomitization.

  12. Here We Like "Playing" Princesses--Newcomer Migrant Children's Transitions within Day Care: Exploring Role Play as an Indication of Suitability and Home and Belonging

    ERIC Educational Resources Information Center

    Kalkman, Kris; Clark, Alison

    2017-01-01

    Using the concept of "suitability" to describe newcomer migrant children's connection to multiple fields of social and cultural relations, we explore a newcomer migrant girl's transition from an introductory group for migrant children with a refugee background into a mainstream day-care group. Inspired by sociocultural and transitional…

  13. Sodium-limestone double alkali flue gas desulfurization process with improved limestone utilization

    SciTech Connect

    Biolchini, R.J.; Boward, W.L. Jr.; Wang, K.H.

    1987-08-18

    This patent describes a sodium-limestone double alkali process for the continuous desulfurization of flue gas, having the steps of absorbing sulfur dioxide from an SO/sub 2/-containing gas stream in an absorber with an aqueous solution of sodium sulfite and sodium bisulfite, diverting at least a portion of the absorber effluent solution for regeneration with limestone, introducing limestone into the diverted absorber effluent solution to convert bisulfite to sulfite, separating by-product solids from the limestone-treated solution, and returning regenerated solution to the absorber, the improvement for increasing the utilization of the limestone used during the regeneration operation.

  14. Element flux in cleaved limestones

    SciTech Connect

    McNaught, M.A.; Erslev, E.A. . Dept. of Earth Resources)

    1992-01-01

    Spaced cleavage in limestone is commonly assumed to result from dissolution of carbonate minerals and passive concentration of other minerals in cleavage zones. More complicated processes are suggested by new element data acquired with the CSU XRF-macroprobe. Overlapping spot analyses were made along bed parallel traverses across cleavage zones in samples from the Twin Creek Formation (TCF) of southeast Idaho and the Poxono Island Formation (PIF) of eastern Pennsylvania. If calcite is the sole mobile phase, Ca should decrease as the other immobile elements increase proportionately. Though Ca is the only major element which consistently decreases in cleavage zones, changes in the relative proportions of the other elements indicate varying degrees of mobility. Al and Ti both increase in cleavage zones and maintain a constant ratio, suggesting immobile behavior. Because Al is more abundant than Ti, mobilities of other elements are determined relative to Al. Mg/Al and Fe/Al ratios are constant for PIF samples but show no systematic relationships in TCF samples, which have lower phyllosilicate contents. Si/Al ratios are relatively constant for most samples but in some PIF samples Si/Al ratios decrease in cleavage zones. This may be the result of dissolution of quartz or Si loss during phyllosilicate reactions. K/Al ratios are constant for limestones with average K/Al atomic ratios of 1/3 whereas samples lower K/Al ratios show increasing K/Al in cleavage zones. This suggests that the growth of new phyllosilicates in the K-poor cleavage zones causes preferential scavenging of potassium. In rocks with K/Al ratios of illite or muscovite, K appears to accumulate with Al by residual concentration. Thus, Al and Ti may be the only viable major element markers for calculating volume flux.

  15. Magnetic hysteresis of limestones: facies control?

    NASA Astrophysics Data System (ADS)

    Borradaile, Graham J.; Chow, Nancy; Werner, Tomasz

    1993-03-01

    The hysteresis properties of 116 non-red, marine limestones from 92 localities indicate that remanence is carried by magnetite of pseudo-single-domain (PSD) and small multidomain (MD) size. Pelagic limestones have paramagnetic matrices and hysteresis properties compatible with larger PSD or MD grain sizes of magnetite, probably associated with detrital clay minerals introduced by pelagic rain-out. Thus they may be less suitable recorders of stable remanence. Other limestone facies (excepting dolomitized examples) have diamagnetic matrices. They include shallow—subtidal limestones which tend to have smaller PSD sizes of magnetite, as do backreef—lagoonal, undifferentiated-shelf and reef facies. It is believed that the wide geographical and temporal range of samples minimizes effects related to post-compaction groundwater flow (late diagenesis) and that the associations recognized should be tested in future studies.

  16. The behavior limestone under explosive load

    NASA Astrophysics Data System (ADS)

    Orlov, M. Yu; Orlova, Yu N.; Bogomolov, G. N.

    2016-11-01

    Limestone behavior under explosive loading was investigated. The behavior of the limestone by the action of the three types of explosives, including granular, ammonite and emulsion explosives was studied in detail. The shape and diameter of the explosion craters were obtained. The observed fragments after the blast have been classified as large, medium and small fragments. Three full-scale experiments were carried out. The research results can be used as a qualitative test for the approbation of numerical methods.

  17. An Exploration of Friendships and Socialization for Adolescents with Autism Engaged in Massively Multiplayer Online Role-Playing Games (MMORPG)

    ERIC Educational Resources Information Center

    Gallup, Jennifer; Duff, Christine; Serianni, Barbara; Gallup, Adam

    2016-01-01

    A phenomenological study was conducted to investigate the social experiences and perceptions of friendship among three adolescents with an Autism Spectrum Disorder (ASD) engaged in online videogame play in the context of a massively multiplayer online role-playing game (MMORPG). Semi-structured interviews with three participants, diagnosed with…

  18. An Exploration of Friendships and Socialization for Adolescents with Autism Engaged in Massively Multiplayer Online Role-Playing Games (MMORPG)

    ERIC Educational Resources Information Center

    Gallup, Jennifer; Duff, Christine; Serianni, Barbara; Gallup, Adam

    2016-01-01

    A phenomenological study was conducted to investigate the social experiences and perceptions of friendship among three adolescents with an Autism Spectrum Disorder (ASD) engaged in online videogame play in the context of a massively multiplayer online role-playing game (MMORPG). Semi-structured interviews with three participants, diagnosed with…

  19. [Limestone and pyrite-limestone constructed wetlands for treating river water].

    PubMed

    Zhang, Jing; Li, Rui-hua; Li, Jie; Hu, Jun-song; Sun, Qian-qian

    2013-09-01

    Polluted river water was treated with limestone and pyrite-limestone subsurface horizontal constructed wetlands. The aims were to know the performance of two wetlands on removal of common pollutants, especially nitrogen and phosphorus, and analyze the actions of these minerals. The relationship between hydraulic retention time and purification performance of two constructed wetlands was studied. The optimal hydraulic retention time for pollutant removal was about 3 d, The average removal efficiency of COD, TN and TP were 51%, 70% and 95%, respectively. With same influent and hydraulic loading, the average removal efficiency of COD, NH4+ -N, TN and TP were 53.93%, 82.13%, 66%, 50.9%, and 51.66%, 77.43%, 72.06%, 97.35% for limestone and pyrite-limestone constructed wetlands, respectively. There were few differences between limestone and pyrite-limestone wetlands on COD removal, but the nitrogen and phosphorus removal of pyrite-limestone constructed wetland was higher than that of limestone constructed wetland. The phosphorus removal of pyrite-limestone wetland was more efficiency and stable, not affected by temperature.

  20. On play and playing.

    PubMed

    Rudan, Dusko

    2013-12-01

    The paper offers a review of the development of the concept of play and playing. The true beginnings of the development of the theories of play are set as late as in the 19th century. It is difficult to define play as such; it may much more easily be defined through its antipode--work. In the beginning, play used to be connected with education; it was not before Freud's theory of psychoanalysis and Piaget's developmental psychology that the importance of play in a child's development began to be explained in more detail. The paper further tackles the role of play in the adult age. Detailed attention is paid to psychodynamic and psychoanalytic authors, in particular D. W. Winnicott and his understanding of playing in the intermediary (transitional) empirical or experiential space. In other words, playing occupies a space and time of its own. The neuroscientific concept of playing is also tackled, in the connection with development as well.

  1. Exploring the Role Played by Error Correction and Models on Children's Reported Noticing and Output Production in a L2 Writing Task

    ERIC Educational Resources Information Center

    Coyle, Yvette; Roca de Larios, Julio

    2014-01-01

    This article reports an empirical study in which we explored the role played by two forms of feedback--error correction and model texts--on child English as a foreign language learners' reported noticing and written output. The study was carried out with 11- and 12-year-old children placed in proficiency-matched pairs who engaged in a…

  2. Reducing energy-related CO2 emissions using accelerated weathering of limestone

    USGS Publications Warehouse

    Rau, Greg H.; Knauss, Kevin G.; Langer, William H.; Caldeira, Ken

    2007-01-01

    The use and impacts of accelerated weathering of limestone (AWL; reaction: CO2+H2O+CaCO3→Ca2++2(HCO3-) is explored as a CO2 capture and sequestration method. It is shown that significant limestone resources are relatively close to a majority of CO2-emitting power plants along the coastal US, a favored siting location for AWL. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could provide an inexpensive or free source of AWL carbonate. With limestone transportation then as the dominant cost variable, CO2 mitigation costs of $3-$4/tonne appear to be possible in certain locations. Perhaps 10–20% of US point–source CO2 emissions could be mitigated in this fashion. It is experimentally shown that CO2 sequestration rates of 10-6 to 10-5 moles/sec per m2 of limestone surface area are achievable, with reaction densities on the order of 10-2 tonnes CO2 m-3day-1, highly dependent on limestone particle size, solution turbulence and flow, and CO2 concentration. Modeling shows that AWL would allow carbon storage in the ocean with significantly reduced impacts to seawater pH relative to direct CO2 disposal into the atmosphere or sea. The addition of AWL-derived alkalinity to the ocean may itself be beneficial for marine biota.

  3. SNiPlay3: a web-based application for exploration and large scale analyses of genomic variations

    PubMed Central

    Dereeper, Alexis; Homa, Felix; Andres, Gwendoline; Sempere, Guilhem; Sarah, Gautier; Hueber, Yann; Dufayard, Jean-François; Ruiz, Manuel

    2015-01-01

    SNiPlay is a web-based tool for detection, management and analysis of genetic variants including both single nucleotide polymorphisms (SNPs) and InDels. Version 3 now extends functionalities in order to easily manage and exploit SNPs derived from next generation sequencing technologies, such as GBS (genotyping by sequencing), WGRS (whole gre-sequencing) and RNA-Seq technologies. Based on the standard VCF (variant call format) format, the application offers an intuitive interface for filtering and comparing polymorphisms using user-defined sets of individuals and then establishing a reliable genotyping data matrix for further analyses. Namely, in addition to the various scaled-up analyses allowed by the application (genomic annotation of SNP, diversity analysis, haplotype reconstruction and network, linkage disequilibrium), SNiPlay3 proposes new modules for GWAS (genome-wide association studies), population stratification, distance tree analysis and visualization of SNP density. Additionally, we developed a suite of Galaxy wrappers for each step of the SNiPlay3 process, so that the complete pipeline can also be deployed on a Galaxy instance using the Galaxy ToolShed procedure and then be computed as a Galaxy workflow. SNiPlay is accessible at http://sniplay.southgreen.fr. PMID:26040700

  4. SNiPlay3: a web-based application for exploration and large scale analyses of genomic variations.

    PubMed

    Dereeper, Alexis; Homa, Felix; Andres, Gwendoline; Sempere, Guilhem; Sarah, Gautier; Hueber, Yann; Dufayard, Jean-François; Ruiz, Manuel

    2015-07-01

    SNiPlay is a web-based tool for detection, management and analysis of genetic variants including both single nucleotide polymorphisms (SNPs) and InDels. Version 3 now extends functionalities in order to easily manage and exploit SNPs derived from next generation sequencing technologies, such as GBS (genotyping by sequencing), WGRS (whole gre-sequencing) and RNA-Seq technologies. Based on the standard VCF (variant call format) format, the application offers an intuitive interface for filtering and comparing polymorphisms using user-defined sets of individuals and then establishing a reliable genotyping data matrix for further analyses. Namely, in addition to the various scaled-up analyses allowed by the application (genomic annotation of SNP, diversity analysis, haplotype reconstruction and network, linkage disequilibrium), SNiPlay3 proposes new modules for GWAS (genome-wide association studies), population stratification, distance tree analysis and visualization of SNP density. Additionally, we developed a suite of Galaxy wrappers for each step of the SNiPlay3 process, so that the complete pipeline can also be deployed on a Galaxy instance using the Galaxy ToolShed procedure and then be computed as a Galaxy workflow. SNiPlay is accessible at http://sniplay.southgreen.fr.

  5. Playing in School or at Home? An Exploration of the Effects of Context on Educational Game Experience

    ERIC Educational Resources Information Center

    De Grove, Frederik; Van Looy, Jan; Neys, Joyce; Jansz, Jeroen

    2012-01-01

    The goal of this study is to gain insight into the effects of context on educational game experience. Using a quasi-experimental setup, it compares the playing and learning experiences of adolescent players of the awareness-raising game PING in a domestic (N=135) and a school (N=121) context. Results indicate that both gaming (identification,…

  6. Exploring the Behavioral Patterns of Learners in an Educational Massively Multiple Online Role-Playing Game (MMORPG)

    ERIC Educational Resources Information Center

    Hou, Huei-Tse

    2012-01-01

    Massively multiple online role-playing games (MMORPGs) are very popular among students. Educational MMORPGs, however, are very rare, as are studies on gamers' behavioral patterns during such games. The current study is an empirical observation and analysis of the behavioral patterns of 100 gamers participating in an educational MMORPG called…

  7. Exploring the Behavioral Patterns of Learners in an Educational Massively Multiple Online Role-Playing Game (MMORPG)

    ERIC Educational Resources Information Center

    Hou, Huei-Tse

    2012-01-01

    Massively multiple online role-playing games (MMORPGs) are very popular among students. Educational MMORPGs, however, are very rare, as are studies on gamers' behavioral patterns during such games. The current study is an empirical observation and analysis of the behavioral patterns of 100 gamers participating in an educational MMORPG called…

  8. Clay Play

    ERIC Educational Resources Information Center

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  9. Clay Play

    ERIC Educational Resources Information Center

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  10. Exergames "As a Teacher" of Movement Education: Exploring Knowing in Moving When Playing Dance Games in Physical Education

    ERIC Educational Resources Information Center

    Nyberg, Gunn; Meckbach, Jane

    2017-01-01

    Background: A fundamental dimension of school physical education (PE) is arguably movement and movement activities. However, there is a lack of discussion in the context of PE regarding what can be called the capability to move in terms of coordinative abilities, body consciousness and educing bodily senses. Purpose: This article explores and…

  11. Exergames "As a Teacher" of Movement Education: Exploring Knowing in Moving When Playing Dance Games in Physical Education

    ERIC Educational Resources Information Center

    Nyberg, Gunn; Meckbach, Jane

    2017-01-01

    Background: A fundamental dimension of school physical education (PE) is arguably movement and movement activities. However, there is a lack of discussion in the context of PE regarding what can be called the capability to move in terms of coordinative abilities, body consciousness and educing bodily senses. Purpose: This article explores and…

  12. Laser Removal of Protective Treatments on Limestone

    NASA Astrophysics Data System (ADS)

    Gómez-Heras, M.; Rebollar, E.; Alvarez de Buergo, M.; Oujja, M.; Fort, R.; Castillejo, M.

    This work presents an investigation of the laser removal of polymeric materials acting as consolidants and water-repellents on limestone used on buildings of architectural and artistic value. The removal of the consolidant Paraloid B-72 and the water-repellent product Tegosivin HL-100, applied on samples of Colmenarand Bateig limestone, was studied as a function of the laser wavelength, by using the four harmonics of a Q-switched Nd:YAG laser (1064, 532, 355 and 266 nm). Elimination of the coatings and subsequent surface modifications were monitored through colorimetry, roughness measurements and scanning electron microscopy (SEM). The fundamental laser radiation was effective in removing the treatments, although thermal alteration processes were induced on the calcite crystals of the limestone. The best results were obtained by irradiation in the near UV at 355 nm.

  13. The Research Process on Converter Steelmaking Process by Using Limestone

    NASA Astrophysics Data System (ADS)

    Tang, Biao; Li, Xing-yi; Cheng, Han-chi; Wang, Jing; Zhang, Yun-long

    2017-08-01

    Compared with traditional converter steelmaking process, steelmaking process with limestone uses limestone to replace lime partly. A lot of researchers have studied about the new steelmaking process. There are much related research about material balance calculation, the behaviour of limestone in the slag, limestone powder injection in converter and application of limestone in iron and steel enterprises. The results show that the surplus heat of converter can meet the need of the limestone calcination, and the new process can reduce the steelmaking process energy loss in the whole steelmaking process, reduce carbon dioxide emissions, and improve the quality of the gas.

  14. Diagenetic cements in transgressive and regressive limestone members on the Stanton Limestone (Upper Pennsylvanian), northern midcontinent

    SciTech Connect

    Xiong, Bin; Heckel, P.H.; Gonzalez, L.A. . Dept. of Geology)

    1992-01-01

    Detailed cathodoluminescent microscopy reveals various types and phases of cement growth preserved in the two limestone members of the Stanton Limestone, which represents a complete cycle of sea level rise and fall during deposition. In the transgressive Captain Creek Limestone Member, early cements are mainly isopachous rims within brachiopods. In the regressive Stoner Limestone Member, early cements are both intergranula rand intragranular isopachous rims in oolitic and skeletal grainstones and in wackestones, as well as non-luminescent syntaxial overgrowths around echinoderm grains. The second phase of cementation in both members consists of luminescence void-filling blocky calcite and syntaxial overgrowths. The latest phase of cementation in both members comprises non-luminescent void-filling and/or replacement ferroan dolomite formed during burial. The early cements are more enriched in Fe and more enriched in Mg than in Sr. However, there seems to be little difference in trace elemental compositions between the transgressive and regressive limestones in general, although certain types of cements confined to one member fall into a relatively small field. The blocky calcites exhibit much higher Fe and Mn content than the early cements. The ferroan dolomite exhibits higher Fe and Mn concentration in the transgressive than in the regressive limestone. The greater abundance of marine cements in the regressive limestone is attributed to greater residence time in high-energy warm marine environments. Differences in Fe and Mn concentration between transgressive and regressive limestone cements are attributed to differences in redox conditions of diagenetic fluids controlled by the offshore Eudora Shale separating these two limestones.

  15. Combined Neutron and X-Ray Radiographic/Tomographic Analysis of Dissolution Limestones under Acidic Conditions

    NASA Astrophysics Data System (ADS)

    Anovitz, L. M.; Cole, D. R.; Hussey, D. S.; LaManna, J.; Swift, A.; Jacobson, D. L.

    2016-12-01

    Carbon dioxide capture and sequestration in deep geological formations is an important option for reducing greenhouse gas emissions. While the importance of porosity and pore-evolution has long been recognized, the evolution of porosity and permeability in reactive carbonates exposed to CO2-loaded brines is not well constrained. A typical pH range for CO2-acidified brine is 3 to 4.5 depending on alkalinity. This represents a substantial perturbation of typical brines that range from pH 6 to 8. The key questions include how accessible are the pores to fluid transport and how does the pore network evolve as the matrix reacts with the acidic solution? Limestones and dolostones contain nano- to macroscale porosity comprised of cracks, grain boundaries, fluid inclusions, single pores, vugs and networks of pores of random shapes and orientations. Accessible, interconnected pores may act as pore throats, constraining overall flow and are the most likely locations for extensive rock alteration. Neutron imaging is well suited to interrogation of fluid flow in porous media. Because of the large scattering cross section of hydrogen it can be used to directly image water or hydrocarbons without an added contrast medium that might modify interfacial tension and fluid/fluid interactions. In order to understand the reaction of acidified fluids we used simultaneous neutron and X-ray tomography to study the uptake and reaction of water and an acidic fluid (pH 1 HCl) with two types of Indiana limestone, one with a permeability of 2-4 mD, and the other 70 mD. One set of experiments explored capillary uptake in a dry core. These documented rapid uptake and CO2 bubble formation at the inlet. A second set introduced at a constant forced flow rate of 10 ml/min. Both core types exhibited wormhole formation, but the low perm limestone wormhole consisted of one well-delineated channel with a few side "tributaries," whereas the high perm core exhibited a more diffuse array of channels. Post

  16. A Systems Approach to Identifying Exploration and Development Opportunities in the Illinois Basin: Digital Portifolio of Plays in Underexplored Lower Paleozoic Rocks [Part 1 of 2

    SciTech Connect

    Seyler, Beverly; Harris, David; Keith, Brian; Huff, Bryan; Lasemi, Yaghoob

    2008-06-30

    This study examined petroleum occurrence in Ordovician, Silurian and Devonian reservoirs in the Illinois Basin. Results from this project show that there is excellent potential for additional discovery of petroleum reservoirs in these formations. Numerous exploration targets and exploration strategies were identified that can be used to increase production from these underexplored strata. Some of the challenges to exploration of deeper strata include the lack of subsurface data, lack of understanding of regional facies changes, lack of understanding the role of diagenetic alteration in developing reservoir porosity and permeability, the shifting of structural closures with depth, overlooking potential producing horizons, and under utilization of 3D seismic techniques. This study has shown many areas are prospective for additional discoveries in lower Paleozoic strata in the Illinois Basin. This project implemented a systematic basin analysis approach that is expected to encourage exploration for petroleum in lower Paleozoic rocks of the Illinois Basin. The study has compiled and presented a broad base of information and knowledge needed by independent oil companies to pursue the development of exploration prospects in overlooked, deeper play horizons in the Illinois Basin. Available geologic data relevant for the exploration and development of petroleum reservoirs in the Illinois Basin was analyzed and assimilated into a coherent, easily accessible digital play portfolio. The primary focus of this project was on case studies of existing reservoirs in Devonian, Silurian, and Ordovician strata and the application of knowledge gained to future exploration and development in these underexplored strata of the Illinois Basin. In addition, a review of published reports and exploration in the New Albany Shale Group, a Devonian black shale source rock, in Illinois was completed due to the recent increased interest in Devonian black shales across the United States. The New

  17. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, Greg H.; Knauss, Kevin G.; Langer, William H.; Caldeira,

    2004-01-01

    We evaluate accelerated weathering of limestone (AWL: CO2 + CaCO3 + H2O=> Ca2+ + 2HCO3-) as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology. With access to seawater and limestone being essential to this approach, significant limestone resources are close to most CO2-emitting power plants along the coastal US. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could be used as an inexpensive source of AWL carbonate. Under such circumstances CO2 mitigation cost could be as low as $3-$4/tonne. More broadly, 10-20% of US point-source CO2 emissions could be treated at $20-$30/tonne CO2. AWL end-solution disposal in the ocean would significantly reduce effects on ocean pH and carbonate chemistry relative to those caused by direct atmospheric or ocean CO2 disposal. Indeed, the increase in ocean Ca2+ and bicarbonate offered by AWL should enhance growth of corals and other calcifying marine organisms.

  18. Fly ash disposal in a limestone quarry

    SciTech Connect

    Peffer, J.R.

    1982-05-01

    Approximately 740 000 tons of eastern bituminous coal fly ash were deposited at the abandoned Zullinger limestone quarry from 1973-1980. The quarry extended below the water table and was not lined to isolate the ash from the aquifer. Long-term groundwater pollution has apparently not resulted.

  19. Limestone bed treats coal pile runoff

    SciTech Connect

    Huntington, R.L.

    1981-07-01

    Acid leachate caused by storm gave rise to a serious water pollution problem and discoloured the banks of a creek for 3 miles. In order to overcome this problem, the surface of the coal pile storage area was analyzed and treated with surplus of powdered agricultural limestone to neutralise the acid in place as it is formed.

  20. Limestone bed treats coal pile runoff

    SciTech Connect

    Huntington, R.L.

    1981-07-01

    Acid leachate caused by storm runoff from a 5-acre coal storage area caused a serious water pollution problem and discolored the banks of a creek for 3 miles. To overcome this problem, the surface of the coal pile storage area was analyzed and treated with surplus of powdered agricultural limestone to neutralize the acid in place as it formed.

  1. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ground limestone. 184.1409 Section 184.1409 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as...

  2. Crystalline marble beats limestone for fluegas desulfurization

    SciTech Connect

    1996-05-01

    NovaCon Energy Systems, Inc. (Bedford, NY) has developed an alternative to conventional limestone sorbents. The new process uses a class of marble, selected with a proprietary model. Recent pilot- and full-scale demonstrations in pulverized-coal (PC) and circulating fluidized bed (CFB) boilers suggest that these patented sorbents outperform conventional limestone for the simultaneous control of SOx, NOx, and particulates during the combustion of coal and sulfur-rich fuels, such as oil, mixed municipal waste and used tires. Dubbed thermally active marbles (TAMs), these sorbents are chemically identical to grainy limestone (whose main constituent is calcium carbonate or calcite). However, thanks to the increased pressures and temperatures experienced during their geologic history, these metamorphic minerals have a regular crystalline structure that offers some advantages in the combustion zone. TAMs, on the other hand, enjoy better calcium-utilization rates because upon heating, they cleave along inter- and intra-crystalline faces, continuously exposing fresh surfaces. By minimizing the self-extinguishment suffered by limestone sorbents, TAMs are effective over operating temperatures from 1,200 F to 2,800 F, which is 400 F higher than other calcium-based sorbents. This allows them to be injected closer to the burner or combustion grate to maximize residence time in the unit.

  3. Watching brain TV and playing brain ball exploring novel BCI strategies using real-time analysis of human intracranial data.

    PubMed

    Jerbi, Karim; Freyermuth, Samson; Minotti, Lorella; Kahane, Philippe; Berthoz, Alain; Lachaux, Jean-Philippe

    2009-01-01

    A large body of evidence from animal studies indicates that motor intention can be decoded via multiple single-unit recordings or from local field potentials (LFPs) recorded not only in primary motor cortex, but also in premotor or parietal areas. In humans, reports of invasive data acquisition for the purpose of BCI developments are less numerous and signal selection for optimal control still remains poorly investigated. Here we report on our recent implementation of a real-time analysis platform for the investigation of ongoing oscillations in human intracerebral recordings and review various results illustrating its utility for the development of novel brain-computer and brain-robot interfaces. Our findings show that the insight gained both from off-line experiments and from online functional exploration can be used to guide future selection of the sites and frequency bands to be used in a translation algorithm such as the one needed for a BCI-driven cursor control. Overall, the findings reported with our online spectral analysis platforms (Brain TV and Brain Ball) indicate the feasibility of online functional exploration via intracranial recordings in humans and outline the direct benefits of this approach for the improvement of invasive BCI strategies in humans. In particular, our findings suggest that current BCI performance may be improved by using signals recorded from various systems previously unexplored in the context of BCI research such as the oscillatory activity recorded in the oculomotor networks as well as higher cognitive processes including working memory, attention, and mental calculation networks. Finally, we discuss current limitations of the methodology and outline future paths for innovative BCI research.

  4. Mineralogical characterization of the Shelburne marble and the Salem limestone

    SciTech Connect

    McGee, E.S.

    1989-01-01

    Samples of Shelburne marble and Salem limestone were selected to represent marbles and limestones used in buildings and monuments. The Royal variety of Shelburne marble is a white marble predominantly composed of calcite but has heterogeneously distributed gray inclusions. The select buff Salem limestone is a beige, homogeneous, fossiliferous limestone, predominantly composed of fragments of echinoderms and bryozoans. The author reports that both samples are appropriate test stones for the National Acid Precipitation Assessment Program stone exposure studies.

  5. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States

    SciTech Connect

    Reimann, K.J.

    1991-09-01

    Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.

  6. Limestone dissolution induced by fungal mycelia, acidic materials, and carbonic anhydrase from fungi.

    PubMed

    Li, Wei; Zhou, Peng-Peng; Jia, Li-Ping; Yu, Long-Jiang; Li, Xue-Li; Zhu, Min

    2009-01-01

    Microorganisms influence the dissolution of a number of minerals. Limestone is one of the most abundant rock types in karst areas, and is predominantly calcium carbonate. Two types of experimental systems were designed in this paper, to make comparisons of limestone dissolution rate among the acidic materials and extracellular carbonic anhydrase (CA) excreted by fungi and the enwrapping effect of fungal mycelia. One was the simulated experimental system containing microorganisms. Another was the simulated experimental system without microorganisms. Results of previous experiment indicated that the acidic materials and CA like enzymatic materials excreted by fungi and the enwrapping effect of fungal mycelia were important factors influencing limestone dissolution. In the three factors mentioned above, the dissolution effect was mycelia enwraping effect>acidic dissolution effect>CA enzymatic effect. The results of the second experiment demonstrated further that the limestone dissolution effect of the acidic materials excreted by fungi was stronger than that of CA excreted by fungi. Nevertheless, CA still played an important role in promoting the dissolution of limestone.

  7. What Role Can Avatars Play in e-Mental Health Interventions? Exploring New Models of Client–Therapist Interaction

    PubMed Central

    Rehm, Imogen C.; Foenander, Emily; Wallace, Klaire; Abbott, Jo-Anne M.; Kyrios, Michael; Thomas, Neil

    2016-01-01

    In the burgeoning field of e-mental health interventions, avatars are increasingly being utilized to facilitate online communication between clients and therapists, and among peers. Avatars are digital self-representations, which enable individuals to interact with each other in computer-based virtual environments. In this narrative review, we examine the psychotherapeutic applications of avatars that have been investigated and trialed to date. Five key applications were identified (1) in the formation of online peer support communities; (2) replicating traditional modes of psychotherapy by using avatars as a vehicle to communicate within a wholly virtual environment; (3) using avatar technology to facilitate or augment face-to-face treatment; (4) as part of serious games; and (5) communication with an autonomous virtual therapist. Across these applications, avatars appeared to serve several functions conducive to treatment engagement by (1) facilitating the development of a virtual therapeutic alliance; (2) reducing communication barriers; (3) promoting treatment-seeking through anonymity; (4) promoting expression and exploration of client identity; and (5) enabling therapists to control and manipulate treatment stimuli. Further research into the feasibility and ethical implementation of avatar-based psychotherapies is required. PMID:27917128

  8. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.

    1997-01-01

    This summary of international nonfuel mineral exploration activities for 1996 uses available data from literature, industry, and US Geological Survey (USGS) specialists. Data on exploration budgets by region and commodity are reported, significant mineral discoveries and exploration target areas are identified and government programs affecting the mineral exploration industry are discussed. Inferences and observations on minerals industry direction are drawn from these data.

  9. Physicochemical characterizations of limestone for fluidized-bed coal combustion

    SciTech Connect

    Fuller, E.L. Jr.; Yoos, T.R. III; Walia, D.S.

    1981-05-01

    This study is an investigation of the physicochemical characteristics of three limestone samples, Quincy limestone (-20 + 60), Franklin limestone (-12 + 30), and Franklin limestone (-6 + 16), currently being tested at Oak Ridge National Laboratory for use in a fluidized-bed coal combustion unit. By correlating the chemistry, mineralogy, and surface area of these samples with empirical data obtained at Argonne National Laboratory, the sulfur capture ability and performance of these limestones can be loosely predicted. X-ray fluorescence and neutron activation analysis revealed a very high calcium content and very low concentrations of other elements in the three samples. X-ray diffraction patterns and petrographic examination of the limestone grains detected essentially no dolomite in the Quincy limestone or the fine Franklin limestone samples. The coarse Franklin limestone sample showed dolomite to be present in varying amounts up to maximum of 2.75%. Limited surface chemistry investigations of the samples were undertaken. Limestone and dolostone resources of the Tennessee Valley Authority region are widespread and abundant, and judged sufficient to meet industrial demand for many years. No problems are anticipated in securing limestone or dolostone supplies for a commercial fluidized-bed combustion plant in the Tennessee Valley Authority region. Transportation facilities and costs for limestone or dolostone will influence the siting of such a commercial fluidized-bed combustion plant. The most promising location in the Tennessee Valley Authority region at this time is Paducah, Kentucky.

  10. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.

    2001-01-01

    Part of an annual review of mines and mineral resources in the U.S. An overview of nonfuel-mineral exploration in 2000 is presented. Principal exploration target was gold exploration in Latin America, Australia, and the U.S. There was a decrease of 18 percent in the exploration budget for gold as compared with the budget for 1999. Statistical information on nonfuel-mineral exploration worldwide is presented, analyzed, and interpreted.

  11. Drenov Grič black limestone as a heritage stone from Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Rožič, Boštjan; Žbona, Nina; Bedjanič, Mojca; Mladenović, Ana

    2016-04-01

    The limestone known as Drenov Grič black limestone is considered one of the most beautiful Slovenian natural stones due to its homogenous black colour interwoven with white veins. Over the centuries it has been exploited from three major quarries west of Ljubljana, with the main quarry at Drenov Grič playing the primary role in supplying building material for the central parts of Slovenia. All the quarries are currently not active. In the area of Drenov grič, one locality of black limestone is protected - Kuclerjev kamnolom quarry. It has the status of 'valuable natural feature of national importance' and is protected as a natural monument. This well-stratified micritic limestone of Triassic (Carnian) age occurs in 10-80 cm thick beds, with thin marl interlayers. The stone contains abundant fossil bivalves and ostracods. Apart from calcite as the main component, dolomite, quartz, illite/muscovite and pyrite are also present. The limestone is relatively rich in carbonaceous and bituminous organic matter, which is responsible for the black colour of the stone. This component does not have any adverse effect on mechanical and physical characteristics. As the lime¬stone is dense, thus facilitating a good polish, it has been commercially considered as marble. The stone has been widely used in Slovenian monuments, not only in Ljubljana but also in other regions of Slovenia. Many inner and outdoor architectural elements were made of this limestone, particularly in the baroque period, which was known for the extensive use of black limestones also in other European countries. The most significant use of this limestone has been recorded in sculptured portals and altars. Some of the important buildings decorated utilising this stone, are the Ljubljana Cathedral, the St. James's Parish Church, and the Franciscan Church of the Annunciation, all of which are located in Ljubljana, some of them having been declared as cultural monuments of local or national importance. When

  12. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    SciTech Connect

    Bizzozero, Julien Scrivener, Karen L.

    2015-10-15

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  13. EPA compares lime, limestone FGD systems

    SciTech Connect

    Not Available

    1984-05-28

    According to a recent report by the EPA, flue gas desulfurization processes using lime require lower capital investments than limestone processes, and at low coal sulfur contents, annual revenue requirements are also lower. But this advantage disappears when coal sulfur content rises above 2%. A study of FGD systems performed by TVA evaluated absorber types, forced oxidation and the use of additives. The study compared processes with forced oxidation and landfill disposal, and found these have lower capital investments than processes without forced oxidation using pond disposal. Using additives in the limestone processes reduces both capital investment and annual revenue requirements. Adipic acid seems more efficient than MgO. Comparing absorber types, EPA found that for all systems, the TCA process was lowest in capital investment and annual revenue requirements.

  14. Limestone-gypsum flue gas desulfurization process

    SciTech Connect

    Kuroda, H.; Hashimoto, T.; Kanda, O.; Nishimura, M.; Nishimura, T.; Nozawa, S.

    1984-12-11

    A flue gas desulfurization process capable of producing a high purity gypsum and also making equipment employed as minimum as possible is provided, which process comprises the steps of cooling and dedusting flue gas containing SO /SUB x/ ; contacting the cooled gas with a slurry containing limestone to remove SO /SUB x/ by absorption and also form CaSO/sub 3/; controlling the pH of the resulting slurry and then blowing air therein to form gypsum; and separating gypsum from the resulting slurry. As a modification of the above process, the slurry of the above second absorption step is further fed to the above first cooling step where unreacted limestone and SO /SUB x/ are reacted to form CaSO/sub 3/.

  15. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.

    2000-01-01

    This summary of international nonfuel mineral exploration activities for 1999 draws upon available data from literature, industry and US Geological Survey (USGS) specialists. The report documents data on exploration budgets by region and commodity and identifies significant mineral discoveries and exploration target areas. It also discusses government programs affecting the mineral exploration industry. And it presents inferences and observations on mineral industry direction based on these data and discussions.

  16. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.

    1998-01-01

    This summary of international nonfuel mineral exploration activities for 1997 draws upon available data from literature, industry and US Geological Sulvey (USGS) specialists. Data on exploration budgets by region and commodity are reported, significant mineral discoveries and exploration target areas are identified and government programs affecting the mineral exploration industry are discussed. Inferences and observations on mineral industry direction are drawn from these data and discussions.

  17. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.; Porter, K.E.

    1999-01-01

    This summary of international nonfuel mineral exploration activities for 1998 draws on available data from literature, industry and US Geological Survey (USGS) specialists. Data on exploration budgets by region and commodity are reported, significant mineral discoveries and exploration target areas are identified and government programs affecting the mineral exploration industry are discussed. Inferences and observations on mineral industry direction are drawn from these data and discussions.

  18. Plant Guide: Limestone hawksbeard: Crepis intermedia

    Treesearch

    L. St. John; D. Tilley

    2012-01-01

    Sunflower family (Asteraceae). Limestone hawksbeard is a native perennial forb with one or two stems arising from a taproot. Plants are 30-70cm tall and basal leaves are 10-40 cm long, pinnatifid, with a fairly broad, undivided midstrip and entire or dentate segments. Plants are densely or sparsely gray-tomentulose. There are 10-60 heads per plant that are 7-12...

  19. Biocalcifying Bacillus subtilis cells effectively consolidate deteriorated Globigerina limestone.

    PubMed

    Micallef, Roderick; Vella, Daniel; Sinagra, Emmanuel; Zammit, Gabrielle

    2016-07-01

    Microbially induced calcite precipitation occurs naturally on ancient limestone surfaces in Maltese hypogea. We exploited this phenomenon and treated deteriorated limestone with biocalcifying bacteria. The limestone was subjected to various mechanical and physical tests to present a statistically robust data set to prove that treatment was indeed effective. Bacillus subtilis conferred uniform bioconsolidation to a depth of 30 mm. Drilling resistance values were similar to those obtained for freshly quarried limestone (9 N) and increased up to 15 N. Treatment resulted in a high resistance to salt deterioration and a slow rate of water absorption. The overall percentage porosity of treated limestone varied by ±6 %, thus the pore network was preserved. We report an eco-friendly treatment that closely resembles the mineral composition of limestone and that penetrates into the porous structure without affecting the limestones' natural properties. The treatment is of industrial relevance since it compares well with stone consolidants available commercially.

  20. Simulation of Hypervelocity Penetration in Limestone

    SciTech Connect

    Antoun, T; Glenn, L; Walton, O; Goldstein, P; Lomov, I; Liu, B

    2005-05-31

    A parameter study was performed to examine the (shock) damage obtained with long-rod and spherical mono-material penetrators impacting two varieties of limestone. In all cases, the impacts were assumed to be normal to the plane of the rock and at zero angle of attack (in the case of the rods). Impact velocities ranged to 15 km/s but most calculations were performed at 4 and 6 km/s and the penetrator mass was fixed at 1000 kg. For unlined underground structures, incipient damage was defined to occur when the peak stress, {sigma}{sub pk}, exceeds 1 kb (100 MPa) and the applied impulse per unit area, I{sub pk}, exceeds 1 ktap (1 kb-{micro}s). Severe damage was assumed to occur when {sigma}{sub pk} exceeds 1 kb and I{sub pk} exceeds 1000 ktaps. Using the latter definition it was found that severe damage in hard, non-porous limestone with spherical impactors extended to a depth of 9 m on-axis for an impact velocity of 4 km/s and 12 m at 6 km/s. Cylinders with length-to-diameter (L/D) ratio of 8.75 achieved depth to severe damage of 23 m and 40 m, respectively under the same conditions. For a limestone medium with 2% initial gas porosity, the latter numbers were reduced to 12 m and 18 m.

  1. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.

    2005-01-01

    The worldwide budget for nonferrous, nonfuel mineral exploration was expected to increase by 58 percent in 2004 from the 2003 budget, according to Metals Economics Group (MEG) of Halifax, Nova Scotia. The increase comes two years after a five-year period of declining spending for mineral exploration (1998 to 2002). Figures suggest a subsequent 27 percent increase in budgeted expenditures from 2002 to 2003. For the second consecutive year, all regional exploration budget estimates were anticipated to increase.

  2. Acid mine drainage neutralization in a pilot sequencing batch reactor using limestone from a paper and pulp industry.

    PubMed

    Vadapalli, V R K; Zvimba, J N; Mathye, M; Fischer, H; Bologo, L

    2015-01-01

    This study investigated the implications of using two grades of limestone from a paper and pulp industry for neutralization of acid mine drainage (AMD) in a pilot sequencing batch reactor (SBR). In this regard, two grades of calcium carbonate were used to neutralize AMD in a SBR with a hydraulic retention time (including settling) of 100 min and a sludge retention time of 360 min, by simultaneously monitoring the Fe(II) removal kinetics and overall assessment of the AMD after treatment. The Fe(II) kinetics removal and overall AMD treatment were observed to be highly dependent on the limestone grade used, with Fe(II) completely removed to levels lower than 50 mg/L in cycle 1 after 30 min using high quality or pure paper and pulp limestone. On the contrary, the other grade limestone, namely waste limestone, could only achieve a similar Fe(II) removal efficiency after four cycles. It was also noticed that suspended solids concentration plays a significant role in Fe(II) removal kinetics. In this regard, using pure limestone from the paper and pulp industry will have advantages compared with waste limestone for AMD neutralization. It has significant process impacts for the SBR configuration as it allows one cycle treatment resulting in a significant reduction of the feed stock, with subsequent generation of less sludge during AMD neutralization. However, the use of waste calcium carbonate from the paper and pulp industry as a feed stock during AMD neutralization can achieve significant cost savings as it is cheaper than the pure limestone and can achieve the same removal efficiency after four cycles.

  3. Oil reservoirs in grainstone aprons around Bryozoan Mounds, Upper Harrodsburg Limestone, Mississippian, Illinois Basin

    SciTech Connect

    Jobe, H.; Saller, A.

    1995-06-01

    Several oil pools have been discovered recently in the upper Harrodsburg Limestone (middle Mississippian) of the Illinois basin. A depositional model for bryozoan mound complexes has allowed more successful exploration and development in this play. In the Johnsonville area of Wayne County, Illinois, three lithofacies are dominant in the upper Harrodsburg: (1) bryozoan boundstones, (2) bryozoan grainstones, and (3) fossiliferous wackestones. Bryozoan boundstones occur as discontinuous mounds and have low porosity. Although bryozoan boundstones are not the main reservoir lithofacies, they are important because they influenced the distribution of bryozoan grainstones and existing structure. Bryozoan grainstones have intergranular porosity and are the main reservoir rock. Bryozoan fragments derived from bryozoan boundstone mounds were concentrated in grainstones around the mounds. Fossiliferous wackestones are not porous and form vertical and lateral seals for upper Harrodsburg grainstones. Fossiliferous wackestones were deposited in deeper water adjacent to bryozoan grainstone aprons, and above grainstones and boundstones after the mounds were drowned. Upper Harrodsburg oil reservoirs occur where grainstone aprons are structurally high. The Harrodsburg is a good example of a carbonate mound system where boundstone cores are not porous, but adjacent grainstones are porous. Primary recovery in these upper Harrodsburg reservoirs is improved by strong pressure support from an aquifer in the lower Harrodsburg. Unfortunately, oil production is commonly decreased by water encroaching from that underlying aquifer.

  4. Quantifying micron-scale grain detachment during weathering experiments on limestone

    NASA Astrophysics Data System (ADS)

    Levenson, Yael; Emmanuel, Simon

    2016-01-01

    Weathering in carbonate rocks is often assumed to be governed by chemical dissolution. Nevertheless, chemical processes can be coupled to mechanical mechanisms, with small grains undergoing partial dissolution along grain boundaries, followed by detachment from the rock surface. Crucially, this process can even extend down to the micron-scale. Although chemo-mechanical detachment could be critical for the understanding of carbonate weathering at the global scale, the role it plays has not been directly quantified. To calculate the contribution of grain detachment to surface retreat rates, and to determine the impact of the flow regime, we carried out a series of flow-through weathering experiments on micritic limestone. Using atomic force microscopy, we obtained high resolution in situ data of surface topography for reacting rock surfaces. In all the experiments, both grain detachment and chemical dissolution were observed. Under the laminar flow conditions we explored, we found no clear correlation between flow rate and the size of detached grains, or between the flow rate and the frequency of grain detachment events. Importantly, our results establish that grain detachment contributes significantly to the overall surface retreat, on average accelerating mass loss by 38%. In addition to speeding up weathering, this micron-scale mechanism could also influence the evolution of porosity in aquifers and hydrocarbon reservoirs, and provide a natural flux of colloids that could transport heavy metals or radionuclides in groundwater.

  5. Spatial play.

    PubMed

    Forrest, D V

    1978-02-01

    More than sharpening our tools or making them sterile, our task in psychotherapy and analysis is to enliven them, find in them the organic, the animate, and the fecund. For our tools are formed of language, more like living nets than like knives, dies, taps, or templates, and our familiary with them might as well be a marriage of love as one of convenience. One's own onymy (Forrest, 1973) of words and phrases that seem to be one's property and private treasury will include, in the case of a doctor who uses words, several such verbal tools that have acquired greater frequency of use and richer and deeper meanings with experience. For me the word play in its affinity for very spatial senses has grown increasingly helpful in meeting both the practical demands of therapeutic communication and the personal need to maintain theoretical structures to support therapeutic work. I wish here to explore the concept of play--contributions to its definition, its developmental stages, applications of play, and its extended properties.

  6. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.

    2002-01-01

    Exploration budgets fell for a fourth successive year in 2001. These decreases reflected low mineral commodity prices, mineral-market investment reluctance, company failures and a continued trend of company mergers and takeovers.

  7. The Helderberg limestone of central Pennsylvania

    USGS Publications Warehouse

    Reeside, John B.

    1917-01-01

    This paper presents the results of a study made during 1913, 1914, and 1915, while the writer was a student at Johns Hopkins University. The formations discussed have been studies in Maryland, New Jersey, and New York, and described with more or less detail, but concerning their occurrence in the intervening area in Pennsylvania little exact information has been available. The conflict in opinion as to the proper position and correlation of the Keyser limestone and as to the interpretation of some of the standard New York sections has made further data very desirable, and the present paper is an attempt to meet a part of the deficiency.

  8. CO2 MITIGATION VIA ACCELERATED LIMESTONE WEATHERING

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K G

    2004-02-27

    The climate and environmental impacts of our current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. As part of this effort, various means of capturing and storing CO2 generated from fossil-fuel-based energy production are being investigated. One of the proposed methods involves a geochemistry-based capture and sequestration process that hydrates point-source, waste CO2 with water to produce a carbonic acid solution. This in turn is reacted and neutralized with limestone, thus converting the original CO2 gas to calcium bicarbonate in solution, the overall reaction being:

  9. Reducing Energy-Related CO2 Emissions Using Accelerated Limestone Weathering

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K

    2004-04-27

    Following earlier descriptions, the use and impacts of accelerated weathering of limestone AWL; reaction: CO{sub 2} + H{sub 2}O + CaCO{sub 3} {yields} Ca{sup 2+} + 2(HCO{sub 3}{sup -}) as a CO{sub 2} capture and sequestration method is further explored. Since ready access to the ocean is likely an essential requirement for AWL, it is shown that significant limestone resources are relatively close to a majority of CO{sub 2}-emitting power plants along the coastal US. Furthermore, waste fines, representing more than 20% of current US crushed limestone production (>10{sup 9} tonnes/yr), could be used in many instances as an inexpensive or free source of AWL carbonate. With limestone transportation to coastal sites then as the dominant cost variable, CO{sub 2} sequestration (plus capture) costs of $3-$4/tonne are achievable in certain locations. While there is vastly more limestone and water on earth than that required for AWL to capture and sequester all fossil fuel CO{sub 2} production, the transportation cost of bringing limestone, seawater, and waste CO{sub 2} into contact likely limits the method's applicability to perhaps 10-20% of US point-source emissions. Using a bench-scale laboratory reactor, it is shown that CO{sub 2} sequestration rates of 10{sup -6} to 10{sup -5} moles/sec per m{sup 2} of limestone surface area are readily achievable using seawater. This translates into reaction densities as high as 2 x 10{sup -2} tonnes CO{sub 2} m{sup -3}day{sup -1}, highly dependent on limestone particle size, solution turbulence and flow, and CO{sub 2} concentration. Modeling of AWL end-solution disposal in the ocean shows significantly reduced effects on ocean pH and carbonate chemistry relative to those caused by direct CO{sub 2} disposal into the atmosphere or ocean. In fact the increase in ocean Ca{sup 2+} and bicarbonate offered by AWL should significantly enhance the growth of corals and other marine calcifiers whose health is currently being threatened by

  10. Effects of salts on limestone dissolution rate in wet limestone flue gas desulfurization

    SciTech Connect

    Ukawa, Naohiko; Takashina, Toru; Oshima, Michio; Oishi, Tsuyoshi )

    1993-11-01

    To understand how the dissolution rate of limestone used for absorbent in a wet flue gas desulfurization plant is affected by the soluble salts formed from hydrogen chloride gas in flue gas as well as from the impurities contained in the used raw material limestone itself, various limestone slurries each supplemented with a single salt of CaCl[sub 2], MgCl[sub 2], NaCl, Na[sub 2]SO[sub 4] and MgSO[sub 4] were titrated with sulfuric acid. From the titration results the dissolution rate was found to vary greatly with the kind and the concentration of the salts with a general tendency to decrease in chloride solution but to increase in sulfate solutions. Based on this finding, the authors proposed a semi-empirical simplified model. The evaluated results using this model closely agreed with the measured values of the limestone dissolution rate both in single-salt solutions and mixed salt solutions. 9 refs., 8 figs., 1 tab.

  11. Elemental analysis of limestone samples from Ewekoro limestone deposit in southwest Nigeria

    NASA Astrophysics Data System (ADS)

    Obiajunwa, E. I.; Nwachukwu, J. I.

    2000-10-01

    Limestone samples of different colours from Ewekoro limestone deposit in Ogun State, Nigeria were subjected to elemental analysis by proton-induced X-ray emission (PIXE) and proton-induced gamma-ray emission (PIGME) techniques. The irradiation was by 2.5 MeV proton beams from the ion beam analysis (IBA) facility of the 3 MV Van de Graaff accelerator at the Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights. Elemental composition and concentrations of 22 major, minor and trace elements were determined. The NIST geological standard, NBS278, was analysed for quality assurance. The concentrations of the major elements (Ca, Fe, K and Al) are similar in the samples while the other major elements differed. Calcium accounts for about 38%, giving 86.8% CaCO 3 content in the limestones. The major elements (Al, Ca, Fe, Si, S and K), present in the limestones, were also found to be enriched in airborne particulate matter studied by earlier workers, thus confirming cement dust as the major contributor to the particulate matter within and around cement factories.

  12. Limestone types used from the classic Karst region in Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Bedjanič, Mojca; Kortnik, Jože; Šmuc, Andrej

    2014-05-01

    The paper presents a variety of limestones from the Karst Region that is one of the most interesting areas containing reserves of natural stones in Slovenia. The region is mainly composed of Cretaceous shallow-water limestone, with the most common type currently excavated being the rudist limestone of the Lipica Formation, which dates to the Santonian to Campanian. Limestones of this formation are mainly represented by a light grey, thick-bedded to massive Lipica limestone rich in (largely fragmented) rudists. Rudist shells can be either relatively well preserved (such as in Lipica Fiorito quarried limestone) or almost completely disintegrated and intensively endolitised (Lipica Unito quarried limestone). Beside the Lipica Formation, natural stone types have been excavated from two other formations or members in the Karst region: the Repen Formation (Repen and Kopriva limestones), and the Tomaj Limestone (dark, laminated limestone within the Lipica Formation). As documented, the region has been associated with the quarrying and processing of stone at least for over two thousand years, i.e. since the Roman period. Although a large number of quarries in all mentioned formations are documented in the Karst region, many are inactive nowadays. Some of the quarries are declared as geological monuments of national importance or officially protected as a natural monument. Karst limestones are considered the highest quality calcareous natural stones in Slovenia. They are characterised by high density, low water absorption and low open porosity; consequently they also exhibit high frost and salt resistance as well as high compressive and flexural strength. Besides in the Karst region and other parts of Slovenia, the Karst limestones were used in the construction of several important buildings and monuments in many other European Countries, and worldwide. Nowadays, they are most commonly used in the construction of façade cladding, pavements, window sills, staircases, indoor

  13. Adipic acid enhanced limestone flue gas desulfurization process - an assessment

    SciTech Connect

    Mobley, J.D.; Chang, J.C.S.

    1981-12-01

    Adipic acid, when used as an additive in a limestone FGD system, greatly increases both SO/sub 2/ removal and limestone utilization. Most existing limestone scrubbers would benefit from adipic acid addition without major process changes. No significant operating problems or adverse environmental impacts have been identified. The adipic acid enhanced system is economically attractive. Waste dibasic acids and glycolic acid appear to provide benefits similar to adipic acid at a lower cost.

  14. Extreme limestone weathering rates due to micron-scale grain detachment

    NASA Astrophysics Data System (ADS)

    Emmanuel, Simon; Levenson, Yael

    2014-05-01

    Chemical dissolution is often assumed to control the weathering rates of carbonate rocks, although some studies have indicated that mechanical erosion could also play a significant role. Quantifying the rates of the different processes is challenging due to the high degree of variability encountered in both field and lab settings. To measure the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Surface retreat rates in fine-grained micritic limestone blocks are found to be as much as 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these elevated reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained carbonate rocks.

  15. The Portuguese Lioz, a Monumental Limestone

    NASA Astrophysics Data System (ADS)

    Silva, Zenaide

    2017-04-01

    Lioz is a microcrystalline limestone which occurs in Portugal and outcrops in the Lisbon area and its neighboring counties Oeiras, Pero Pinheiro, Lameiras. The rock is whitish to light and dark pink and contains 120 million years old rudists fossils. This fossiliferous content imprints a decorative aspect to the rock contributing to its very wide use as construction material and its favorite use in churches and official monuments making it the Royal Stone in Portugal along the XVII and XVIII centuries. Lisbon has the best exposition of Lioz as a fundamental stone in several monuments, the best examples being the Jeronimos Monastery, the Belém Tower, the Cultural Center in Belém and many old churches spread in Lisbon area. Among the latter the Jesuit Church of São Roque is a special example. The fact that the rock stratigraphic sequence allows the different rock colors as white, light and dark pink and a yellow facies variety in a local occurrence (Negrais yellow) makes it a special source for decorative patterns that can be found in a few churches in Lisbon, Évora, Mafra exhibiting "embutidos" technique, of indian origin and inspired on contemporaneous Italian churches. Mafra is the place where a monumental architectural set, composed by three integrated constructions, was built in the XVIII century by king D.João V using Lioz limestone as the main rock material, in all available colors. Along the XVII and XVIII centuries, the rock was transported to some portuguese colonies, mainly as ballast to improve the navigability of the boats, and used at the destinations as construction material for monuments, official buildings and churches. Brazil and especially Salvador, in Bahia, is the best example of that, where Lioz is beautifully exposed in monuments and as true art in many churches where the Portuguese or Italian influences are very strong. All these facts make the Portuguese Lioz Limestone as very representative of the Heritage present in Portugal and its

  16. Playful Gaming.

    ERIC Educational Resources Information Center

    Makedon, Alexander

    A philosophical analysis of play and games is undertaken in this paper. Playful gaming, which is shown to be a synthesis of play and games, is utilized as a category for undertaking the examination of play and games. The significance of playful gaming to education is demonstrated through analyses of Plato's, Dewey's, Sartre's, and Marcuse's…

  17. War, Conflict and Play. Debating Play

    ERIC Educational Resources Information Center

    Hyder, Tina

    2004-01-01

    Young refugees from many parts of the world are increasingly present in UK early years settings. This book explores the crucial importance of play for young refugee children's development. It considers the implications of war and conflict on young children and notes how opportunities for play are denied. It provides a framework for early years…

  18. [Analysis of trace elements in limestone for archeological functions

    SciTech Connect

    Blanc, A.; Holmes, L.; Harbottle, G.

    1998-12-31

    Numerous quarries in the Lutetian limestone formations of the Paris Basin provided stone for the building and the decoration of monuments from antiquity to the present. To determine the origin of stone used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 samples. Petrographic and paleontologic examination of thin sections allows geologists to distinguish Lutetian limestones from Jurassic and Cretaceous limestones. Geologists also seek to formulate hypotheses regarding the origin of Lutetian limestones used for building and sculpture in the Paris region. In the search for the sources of building and sculptural stone, the analytical methods of geologists are limited because often several quarries produce the same lithofacies. A new tool is now available, however, to attack questions of provenance raised by art historians. Because limestones from different sources have distinctive patterns of trace-element concentrations, compositional analysis by neutron activation allows one to compare building or sculptural stone from one monument with stone from quarries or other monuments. This analytical method subjects a powdered limestone sample to standard neutron activation analysis procedures at Brookhaven National Laboratory. With the help of computer programs, the compositional fingerprints of Lutetian limestones can be determined and stored in a database. The limestone database contains data for approximately 2,100 samples from monuments, sculptures and quarries. It is particularly rich in samples from the Paris Basin.

  19. STEAM INJECTION INTO FRACTURED LIMESTONE AT LORING AIR FORCE BASE

    EPA Science Inventory

    A research project on steam injection for the remediation of spent chlorinated solvents from fractured limestone was recently undertaken at the former Loring AFB in Limestone, ME. Participants in the project include the Maine Department of Environmental Protection, EPA Region I,...

  20. [Reactivity of the limestone in wet flue gas desulfurization].

    PubMed

    Zhu, Tian-le; Li, Yao; Ling, Xuan; Liu, Hong-ju; Xu, Feng-gang; Liu, Han-qiang

    2005-11-01

    On the basis of the analysis of chemical components of the natural limestones from different deposits in China, the pore structures of the typical limestones, with the different CaCO3 content, were examined. The reactivity of the limestones was investigated by sulfuric acid titration and gas-liquid absorption methods. The research results showed that the specific surface area of the natural limestones studied in this work was about 1.8 m2/g. It was seen that the pH of the limestone slurry rapidly decreased and then back up when the sulfuric acid was added. The higher the CaCO3 content was, or the smaller the particle size was, the larger the pH back-up rate was, and similarly the faster the SO2 concentration of the reactor outlet increased. The Reactivity of the limestone obtained by the sulfuric acid titration had the same features as that obtained by the gas liquid absorption. Compared with the specific surface area, the CaCO3 content had more effect on the reactivity of the limestones. The particle size of the limestones had a significant effect on the reactivity when the particle size was relatively large, that is less than 300-360 mesh, vice versa.

  1. STEAM INJECTION INTO FRACTURED LIMESTONE AT LORING AIR FORCE BASE

    EPA Science Inventory

    A research project on steam injection for the remediation of spent chlorinated solvents from fractured limestone was recently undertaken at the former Loring AFB in Limestone, ME. Participants in the project include the Maine Department of Environmental Protection, EPA Region I,...

  2. Microfacies and diagenesis of the reefal limestone, Callovian Tuwaiq Mountain Limestone Formation, central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    EL-Sorogy, Abdelbaset S.; Almadani, Sattam A.; Al-Dabbagh, Mohammad E.

    2016-03-01

    In order to document the microfacies and diagenesis of the reefal limestone in the uppermost part of the Callovian Tuwaiq Mountain Limestone Formation at Khashm Al-Qaddiyah area, central Saudi Arabia, scleractinian corals and rock samples were collected and thin sections were prepared. Coral framestone, coral floatstone, pelloidal packstone, bioclastic packstone, bioclastic wacke/packstone, algal wackestone and bioclastic foraminiferal wacke/packstone were the recorded microfacies types. Cementation, recrystallization, silicification and dolomitization are the main diagenetic alterations affected the aragonitic skeletons of scleractinian corals. All coral skeletons were recrystallized, while some ones were dolomitized and silicified. Microfacies types, as well as the fossil content of sclearctinian corals, bivalves, gastropods, brachiopods and foraminifera indicated a deposition in environments ranging from shelf lagoon with open circulation in quiet water below wave base to shallow reef flank and organic build up for the uppermost reefal part of the Tuwaiq Formation in the study area.

  3. Field trial of a pulsed limestone diversion well

    USGS Publications Warehouse

    Sibrell, Philip L.; Denholm, C.; Dunn, Margaret

    2013-01-01

    The use of limestone diversion wells to treat acid mine drainage (AMD) is well-known, but in many cases, acid neutralization is not as complete as would be desired. Reasons for this include channeling of the water through the limestone bed, and the slow reaction rate of the limestone gravel. A new approach to improve the performance of the diversion well was tested in the field at the Jennings Environmental Education Center, near Slippery Rock, PA. In this approach, a finer size distribution of limestone was used so as to allow fluidization of the limestone bed, thus eliminating channeling and increasing particle surface area for faster reaction rates. Also, water flow was regulated through the use of a dosing siphon, so that consistent fluidization of the limestone sand could be achieved. Testing began late in the summer of 2010, and continued through November of 2011. Initial system performance during the 2010 field season was good, with the production of net alkaline water, but hydraulic problems involving air release and limestone sand retention were observed. In the summer of 2011, a finer size of limestone sand was procured for use in the system. This material fluidized more readily, but acid neutralization tapered off after several days. Subsequent observations indicated that the hydraulics of the system was compromised by the formation of iron oxides in the pipe leading to the limestone bed, which affected water distribution and flow through the bed. Although results from the field trial were mixed, it is believed that without the formation of iron oxides and plugging of the pipe, better acid neutralization and treatment would have occurred. Further tests are being considered using a different hydraulic configuration for the limestone sand fluidized bed.

  4. Faunas of Mississippian oolitic limestones: Evidence from Salem Limestone, southern Indiana

    SciTech Connect

    Feldman, H.R. )

    1989-08-01

    In the Salem Limestone of southern Indiana, a correlation exists between the faunal assemblage and abundance of grains with superficial oolitic coatings in grainstones. Coarse, poorly sorted fossiliferous grainstones are dominated by an echinoderm-bryozoan-brachiopod assemblage of fossils with few mollusks. The presence of large whole fossils, such as articulated crinoid calyces, suggest limited transport of skeletal components. Grainstones, dominated by grains with superficial coatings, and foraminifers tend to contain a diverse mollusk-dominated assemblage of gastropods, bivalves, rostroconchs, chitins, and scaphopods. These fossils are disarticulated, but generally are not fragmented even though many of them are thin and delicate. Echinoderms, brachiopods, and bryozoans are repsented in the mollusk-domdinated assemblage almost exclusively by well-rounded and coated fragments, suggesting that they are not in situ. The presence of similar molluscan assemblages in other Mississippian coated-grain grainstones from Alabama (the Monteagle Limestone) and Oklahoma (an unnamed limestone) indicates that the assemblage may have been wide-spread. Mississippian grainstones dominated by oolites (which are not prominent in the Salem) generally have very few fossils.

  5. The Excellence of Play.

    ERIC Educational Resources Information Center

    Moyles, Janet R., Ed.

    Recognizing that for young children, play is a tool for learning, this book compiles contributions by different authors, reflecting both up-to-date research and current classroom practice as they relate to children's play. Part 1 of the book explores the value of play as a cross-cultural concept as well as one rooted in the Western world. Gender…

  6. United Arab Emirates limestones: impact of petrography on thermal behavior

    NASA Astrophysics Data System (ADS)

    Alaabed, Sulaiman; Soltan, Abdel Monem; Abdelghany, Osman; Amin, Bahaa Eldin Mahmoud; El Tokhi, Mohamed; Khaleel, Abbas; Musalim, Abdullah

    2014-12-01

    The thermal behavior of selected limestones from representative localities of the United Arab Emirates is investigated for their suitability for soft-burnt lime production. The limestone samples were collected from the Ghalilah, Musandam, Shauiba, Muthaymimah, Dammam and Asmari formations. The samples were characterized for petrography, mineral and chemical composition, together with physico-mechanical characteristics. Investigative methods included transmitted light microscopy (TLM), cathodoluminescence (CLM) and scanning electron microscopy (SEM), as well as X-ray micro-tomography (μ-CT), XRD, XRF and Archimedes method. The limestone samples were fired in an electrical muffle furnace for 0.25, 0.5, 1 and 2 hours at 800, 900, 1,000 and 1,100 °C. After firing the lime grains were tested to determine their hydration rate and microfabric. The Ghalilah and Musandam limes show the lowest and highest maximum hydration rates, respectively, due mainly to the impure nature of the former, and the smaller lime crystallites and dominance of post-calcination micro-cracks of the latter. The Dammam and Asmari limes preserve a "ghost" microfabric of the original limestone. Higher allochem contents impose lower activation energy requirements for calcination, which implies earlier calcination of the allochems. The Musandam, Shauiba and Muthaymimah limestones may be useful for the production of reactive soft-burnt lime under the applied firing conditions, however, the Dammam and Asmari limestones need more advanced calcination conditions than the applied ones. The Ghalilah limestone was found to be unsuitable for the production of lime.

  7. Geology of Vanport limestone (Pennsylvanian) in Elk County, Pennsylvania

    SciTech Connect

    Kuntz, T.J.

    1987-09-01

    The northernmost exposures of the Vanport limestone appear in Elk and southern McKean Counties, Pennsylvania. The Vanport limestone is structurally preserved in N45/sup 0/-50/sup 0/E trending synclinal folds. Surface exposures are almost all incomplete due to erosion. Drill-hole data assisted in defining areas of nondeposition within Elk County, variations in thickness, and erosional loss by channeling. The Vanport limestone thins to the southeast within Elk County and probably changes from limestone to a shaly limestone (transition zone) and then to shale. Analysis of 70 limestone samples indicated an average insoluble-residue content of 11.4%. The insoluble residue, mainly clay, increases toward the southeast, the direction of paleoshoreline and source of terrigenous sediments. A lack of quartz grains suggests a lack of detrital input from the source area. A study of the vertical variation of the total insoluble-residue content displayed an increase at the bottoms and tops of the stratigraphic section, mirroring the transgressive-regressive phases of the Vanport sea. The majority of allochems were skeletal material in a micritic matrix. Most abundant were mollusks, followed by forams, brachiopods, echinoderms, ostracods, and bryozoans. Composita brachiopods and pseudopunctate and/or punctate brachiopods inhabited offshore stillstand and nearshore transgressive-regressive environments, respectively. Other fossil assemblages displayed spatial and temporal variation. A darker matrix color occurred in stratigraphic sections closer to the paleoshoreline, due to higher clay and organic content. More offshore stratigraphic sections of the limestone were noticeably lighter in color.

  8. Limestone dissolution in flue gas scrubbing: Effect of sulfite

    SciTech Connect

    Gage, C.L.; Rochelle, G.T. )

    1992-07-01

    Batch limestone dissolution experiments were carried out in a pH stat apparatus at 55 C with CO{sub 2} sparging and dissolved sulfite. Particle size distribution, utilization, sulfite in solution, limestone type, and the approach to calcite equilibrium were all found to contribute to the limestone reactivity. In the absence of sulfite, limestone dissolution was controlled solely by mass transfer. For a given stone under mass transfer control, film thickness was found to be independent of pH. The dissolution rate in the presence of sulfite was controlled by a combined surface kinetics/mass transfer regime. SEM micrographs supported this conclusion. A surface rate correlation was developed which accounted for observed inhibition by an inverse dependence on calcium sulfite concentration at the limestone dependence on calcium sulfite concentration at the limestone surface. While the form of the rate expression was applicable to all stones, the surface rate constant was stone dependent. A computer code which accounted for mass transfer with surface kinetics was tested against experimental observations of four limestone types. Changes in pH and the concentrations of calcium, carbonate, sulfite, sulfate, and adipic acid were accurately modeled.

  9. Biological effects of long term fine limestone tailings discharge in a fjord ecosystem.

    PubMed

    Brooks, Lucy; Melsom, Fredrik; Glette, Tormod

    2015-07-15

    Benthic infaunal data collected from 1993 to 2010 were analysed to examine the effect of long term discharge of fine limestone tailings on macrofaunal species assemblages in a fjord. Relative distance from the outfall and proportion of fine tailings in the sediment were correlated with benthic community structure. Diversity decreased with increasing proportion of fine tailings. Biological Traits Analysis (BTA) was used to explore the temporal and spatial effects of the tailings gradient on macrofaunal functional attributes. BTA revealed that all stations along a pressure gradient of fine limestone tailings were dominated by free-living species. As the proportion of fine tailings in the sediment increased, there was an increase in fauna that were smaller, highly mobile, living on or nearer the surface sediment, with shorter lifespans. There was a decrease in permanent tube dwellers, those fauna with low or no mobility, that live deeper in the sediment and have longer lifespans (>5 yrs). Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Play Therapy

    PubMed Central

    Kool, Ritesh

    2010-01-01

    Play therapy represents a unique form of treatment that is not only geared toward young children, but is translated into a language children can comprehend and utilize—the language of play. For the referring provider or practitioner, questions may remain regarding the nature, course, and efficacy of play therapy. This article reviews the theoretical underpinnings of play therapy, some practical considerations, and finally a summary of the current state of research in regard to play therapy. The authors present the practicing psychiatrist with a road map for referring a patient to play therapy or initiating it in appropriate cases. PMID:21103141

  11. EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY PIT ("THE OLD PIT") WITH LEDGE PREPARED FOR LIMESTONE EXTRACTION. AN ELEVEN-HOLE SHOT WILL DISLODGE APPROXIMATELY 25,000 TONS OF LIMESTONE WHICH, AFTER LOADING AND CRUSHING, WILL BE USED FOR ROAD CONSTRUCTION. THE CALERA QUARRY IS ONE OF FOUR ACTIVE VULCAN MATERIALS COMPANY QUARRIES IN THE DISTRICT. VULCAN MATERIALS, A FORTUNE 500 FIRM, ESTABLISHED IN BIRMINGHAM IN 1906 AS BIRMINGHAM SLAG COMPANY, VULCAN MATERIALS IS THE NATION'S FOREMOST PRODUCER OF CONSTRUCTION AGGREGATE AND A LEADING CHEMICALS MANUFACTURER - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  12. EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY PIT ('THE OLD PIT') WITH LEDGE PREPARED FOR LIMESTONE EXTRACTION. AN ELEVEN-HOLE SHOT WILL DISLODGE APPROXIMATELY 25,000 TONS OF LIMESTONE WHICH, AFTER LOADING AND CRUSHING, WILL BE USED FOR ROAD CONSTRUCTION. THE CALERA QUARRY IS ONE OF FOUR ACTIVE VULCAN MATERIALS COMPANY QUARRIES IN THE DISTRICT. VULCAN MATERIALS, A FORTUNE 500 FIRM, ESTABLISHED IN BIRMINGHAM IN 1906 AS BIRMINGHAM SLAG COMPANY, VULCAN MATERIALS IS THE NATION'S FOREMOST PRODUCER OF CONSTRUCTION AGGREGATE AND A LEADING CHEMICALS MANUFACTURER. - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  13. A procedure to evaluate environmental rehabilitation in limestone quarries.

    PubMed

    Neri, Ana Claudia; Sánchez, Luis Enrique

    2010-11-01

    A procedure to evaluate mine rehabilitation practices during the operational phase was developed and validated. It is based on a comparison of actually observed or documented practices with internationally recommended best practices (BP). A set of 150 BP statements was derived from international guides in order to establish the benchmark. The statements are arranged in six rehabilitation programs under three categories: (1) planning (2) operational and (3) management, corresponding to the adoption of the plan-do-check-act management systems model to mine rehabilitation. The procedure consists of (i) performing technical inspections guided by a series of field forms containing BP statements; (ii) classifying evidences in five categories; and (iii) calculating conformity indexes and levels. For testing and calibration purposes, the procedure was applied to nine limestone quarries and conformity indexes were calculated for the rehabilitation programs in each quarry. Most quarries featured poor planning practices, operational practices reached high conformity levels in 50% of the cases and management practices scored moderate conformity. Despite all quarries being ISO 14001 certified, their management systems pay low attention to issues pertaining to land rehabilitation and biodiversity. The best results were achieved by a quarry whose expansion was recently submitted to the environmental impact assessment process, suggesting that public scrutiny may play a positive role in enhancing rehabilitation practices. Conformity indexes and levels can be used to chart the evolution of rehabilitation practices at regular intervals, to establish corporate goals and for communication with stakeholders. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Lining materials for wet limestone absorber modules

    SciTech Connect

    Bauer, J.P.; Cordes, F.A.; Pace, S.

    1995-06-01

    A large number of carbon steel, wet limestone absorber modules originally lined with rubber are now requiring replacement of the lining material. Alternatives for lining absorber modules include: metal wallpaper (high nickel alloy or 6 Mo stainless steel), rubber (natural or chlorobutyl), and glass-reinforced polymers (epoxy, polyester, and vinyl ester). This paper describes the selection process of a replacement lining for the absorber modules at a typical Midwestern power station. For each alternative, a life-cycle cost analysis was conducted, which considered initial capital, operating and maintenance, and replacement costs over the remaining life of the absorber module. The glass-reinforced vinyl ester system and metal wallpaper were predicted to have nearly identical life-cycle costs. However, the flake glass vinyl ester system has a significantly lower initial installed cost and was thus recommended on the basis of life-cycle and initial cost. Actual construction experience is presented, which confirms the recommendation to replace the lining with a flake glass novalac vinyl ester system.

  15. The conservation of Britain's limestone cave resource

    NASA Astrophysics Data System (ADS)

    Hardwick, P.; Gunn, J.

    1996-10-01

    Limestone caves are an important scientific and recreational resource in Britain. During the mid- to late 1970s, cavers and statutory conservation bodies cooperated in a review of cave resources which resulted in the designation of 48 caves or cave areas as Sites of Special Scientific Interest (SSSI). During the same period, the Wildlife and Countryside Act 1981 was introduced to provide more effective planning controls on activities such as agriculture carried out within SSSI boundaries. In one case, at Priddy in the Mendip Hills of Somerset, landowners prevented access to a number of caves in protest over the new, tougher restrictions on agriculture. Faced with the closure, and perceiving that their recreational use of caves might also be controlled, local cavers joined the landowners in opposing the proposals for SSSI designation. As a result the proposals were reviewed, three caves were excluded from the site and controls on the remaining area were relaxed. The case emphasized a need for an effective system to take account of all factors affecting cave conservation, a need which has led to a more constructive dialogue between nature conservation bodies, caver organizations and other interested parties.

  16. City Play.

    ERIC Educational Resources Information Center

    Dargan, Amanda; Zeitlin, Steve

    2000-01-01

    Today, fewer city blocks preserve the confidence of lifestyle and urban geography that sustain traditional games and outdoor play. Large groups of children choosing sides and organizing Red Rover games are no longer commonplace. Teachers must encourage free play; urban planners must build cities that are safe play havens. (MLH)

  17. Wanna Play?

    ERIC Educational Resources Information Center

    Chenfeld, Mimi Brodsky

    2006-01-01

    In this article, the author talks about the importance of play in the lives of children and describes how games and imaginative play contribute to the development of children. From her decades-old collection of countless incidents demonstrating children's love for self-directed, informal, imaginative play, the author shares three incidents that…

  18. City Play.

    ERIC Educational Resources Information Center

    Dargan, Amanda; Zeitlin, Steve

    2000-01-01

    Today, fewer city blocks preserve the confidence of lifestyle and urban geography that sustain traditional games and outdoor play. Large groups of children choosing sides and organizing Red Rover games are no longer commonplace. Teachers must encourage free play; urban planners must build cities that are safe play havens. (MLH)

  19. Mechanisms of time-dependent deformation in porous limestone

    NASA Astrophysics Data System (ADS)

    Brantut, Nicolas; Heap, Michael J.; Baud, Patrick; Meredith, Philip G.

    2014-07-01

    We performed triaxial deformation experiments on a water-saturated porous limestone under constant strain rate and constant stress (creep) conditions. The tests were conducted at room temperature and at low effective pressures Peff=10 and Peff=20 MPa, in a regime where the rock is nominally brittle when tested at a constant strain rate of 10-5 s-1. Under these conditions and at constant stress, the phenomenon of brittle creep occurs. At Peff=10 MPa, brittle creep follows similar trends as those observed in other rock types (e.g., sandstones and granites): only small strains are accumulated before failure, and damage accumulation with increasing strain (as monitored by P wave speeds measurements during the tests) is not strongly dependent on the applied stresses. At Peff=20 MPa, brittle creep is also macroscopically observed, but when the creep strain rate is lower than ≈10-7 s-1, we observe that (1) much larger strains are accumulated, (2) less damage is accumulated with increasing strain, and (3) the deformation tends to be more compactant. These observations can be understood by considering that another deformation mechanism, different from crack growth, is active at low strain rates. We explore this possibility by constructing a deformation mechanism map that includes both subcritical crack growth and pressure solution creep processes; the increasing contribution of pressure solution creep at low strain rates is consistent with our observations.

  20. African oil plays

    SciTech Connect

    Clifford, A.J. )

    1989-09-01

    The vast continent of Africa hosts over eight sedimentary basins, covering approximately half its total area. Of these basins, only 82% have entered a mature exploration phase, 9% have had little or no exploration at all. Since oil was first discovered in Africa during the mid-1950s, old play concepts continue to bear fruit, for example in Egypt and Nigeria, while new play concepts promise to become more important, such as in Algeria, Angola, Chad, Egypt, Gabon, and Sudan. The most exciting developments of recent years in African oil exploration are: (1) the Gamba/Dentale play, onshore Gabon; (2) the Pinda play, offshore Angola; (3) the Lucula/Toca play, offshore Cabinda; (4) the Metlaoui play, offshore Libya/Tunisia; (5) the mid-Cretaceous sand play, Chad/Sudan; and (6) the TAG-I/F6 play, onshore Algeria. Examples of these plays are illustrated along with some of the more traditional oil plays. Where are the future oil plays likely to develop No doubt, the Saharan basins of Algeria and Libya will feature strongly, also the presalt of Equatorial West Africa, the Central African Rift System and, more speculatively, offshore Ethiopia and Namibia, and onshore Madagascar, Mozambique, and Tanzania.

  1. Play Therapy

    PubMed Central

    Lawver, Timothy; Blankenship, Kelly

    2008-01-01

    Play therapy is a treatment modality in which the therapist engages in play with the child. Its use has been documented in a variety of settings and with a variety of diagnoses. Treating within the context of play brings the therapist and the therapy to the level of the child. By way of an introduction to this approach, a case is presented of a six-year-old boy with oppositional defiant disorder. The presentation focuses on the events and interactions of a typical session with an established patient. The primary issues of the session are aggression, self worth, and self efficacy. These themes manifest themselves through the content of the child’s play and narration of his actions. The therapist then reflects these back to the child while gently encouraging the child toward more positive play. Though the example is one of nondirective play therapy, a wide range of variation exists under the heading of play therapy. PMID:19724720

  2. Neogene carbonate exploration play concepts for Northern New Guinea: New iteration from field work and seismic stratigraphy along the Northern New Guinea Fault Zone

    SciTech Connect

    Pigott, J.D.; Geiger, C. )

    1994-07-01

    Recent field reconnaissance, petrography, nanno and foraminifera age determinations, and seismic stratigraphy of the Sepik and Piore subbasins of northern New Guinea reveal the existence of an extensive, tectonically unstable, Miocene-Pliocene carbonate shelf system. These findings represent the first recorded evidence of northern Papuan limestones coeval in age to those of the hydrocarbon productive Salawati Basin of Irian Jaya. Moreover, these observations also demonstrate the significance of episodic activities of the northern New Guinea fault zone upon the changes in carbonate sedimentation and diagenesis. During the Neogene, algal biosparites to foraminiferal biomicrites defined the clean portion of a mixed clastic-carbonate shelf system of the northern New Guinea basin, which began at the central New Guinea cordillera and deepened northward. This shelf was interrupted by coral-coralline algal boundstone fringing- to patch-reef buildups with associated skeletal grainstones. Clean carbonates were spatially and temporally restricted to basement blocks, which episodically underwent uplift while terrigenous dilutes carbonates were more common in adjacently subsiding basement block bathymetric lows. These tectonic expressions were caused by the spatially transient nature of constraining bends of the evolving north New Guinea faults. As shown by seismic stratigraphy, by the late Miocene to the early Pliocene the uplift of the Bewani-Torricelli Mountains sagittally divided the shelf of the northern New Guinea basin into the Ramu-Sepik and the Piore basins. Continued regional sinistral transpression between the Pacific and the New Guinea leading edge of the Indo-Australian plates led to the reverse tilting of the Piore basin, the shallowing of the former distal shelf with concomitant extensive biolithite development (e.g., on subsiding volcanic islands) eventual uplifting of the Oenake Range, and en echelon faulting of the Bewani-Torricelli Mountains.

  3. Limestone - A Crucial and Versatile Industrial Mineral Commodity

    USGS Publications Warehouse

    Bliss, James D.; Hayes, Timothy S.; Orris, Greta J.

    2008-01-01

    Limestone, as used by the minerals industry, is any rock composed mostly of calcium carbonate (CaCO3). Although limestone is common in many parts of the United States, it is critically absent from some. Limestone is used to produce Portland cement, as aggregate in concrete and asphalt, and in an enormous array of other products, making it a truly versatile commodity. Portland cement is essential to the building industry, but despite our Nation's abundance of limestone, there have been cement shortages in recent years. These have been caused in part by a need to find new areas suitable for quarrying operations. To help manage our Nation's resources of such essential mineral commodities, the U.S. Geological Survey (USGS) provides crucial data and scientific information to industry, policymakers, and the public.

  4. Limestone and bronze "Mississippi River Crossing" Bridge plaque located at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Limestone and bronze "Mississippi River Crossing" Bridge plaque located at North corner of Administration Building site - Huey P. Long Bridge, Administration Building, 5100 Jefferson Highway, Jefferson, Jefferson Parish, LA

  5. LUTETIAN LIMESTONES IN THE PARIS REGION: PETROGRAPHIC AND COMPOSITIONAL EXAMINATION

    SciTech Connect

    BLANC,A.; HOLMES,L.L.; HARBOTTLE,G.

    1998-06-11

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific-stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemist whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  6. Lutetian limestones in the Paris region: Petrographic and compositional examination

    SciTech Connect

    Blanc, A.; Holmes, L.L.; Harbottle, G.

    1998-12-31

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists have investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemistry whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  7. VIEW OF LIMESTONE BAS RELIEF "PROMOTE THE GENERAL WELFARE" ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LIMESTONE BAS RELIEF "PROMOTE THE GENERAL WELFARE" ON SOUTH ELEVATION. RESHOOT OF MD-979-13 AFTER REMOVAL OF RAILING. - Greenbelt Community Building, 15 Crescent Road, Greenbelt, Prince George's County, MD

  8. Egyptian limestone for gamma dosimetry: an electron paramagnetic resonance study

    NASA Astrophysics Data System (ADS)

    Salama, E.

    2014-04-01

    The electron paramagnetic resonance (EPR) properties of limestone from a certain Egyptian site were investigated in order to propose an efficient and low-cost gamma dosimeter. Radiation-induced free radicals were of one type which was produced in the limestone samples at g=2.0066 after exposure to gamma radiation (60Co). EPR spectrum was recorded and analyzed. The microwave power saturation curve and the effect of changing modulation amplitude on peak-to- peak signal height were investigated. The response of limestone to different radiation doses (0.5-20 kGy) was studied. Except for the decrease in signal intensities during the first five hours following irradiation, over the period of two months fair stabilities of signal intensities were noticed. From the current results, it is possible to conclude that natural limestone may be a suitable material for radiation dosimetry in the range of irradiation processing.

  9. 1. SOUTH FACADE. CONSTRUCTED (ca. 1895) OF INDIGENOUS LIMESTONE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SOUTH FACADE. CONSTRUCTED (ca. 1895) OF INDIGENOUS LIMESTONE AND USED AS LOCKPORTS CENTRAL HIGH SCHOOL FOR MORE THAN SIXTY YEARS. - Lockport Historic District, Central High School, Lockport, Will County, IL

  10. Facies patterns and depositional environments of Palaeozoic cephalopod limestones

    NASA Astrophysics Data System (ADS)

    Wendt, J.; Aigner, T.

    1985-07-01

    In the eastern Anti-Atlas (Morocco) a platform and basin topography was established during the late Devonian, probably as a result of early Variscan tensional tectonics. Cephalopod limestones were deposited on shallow pelagic platforms, platform slopes and shallow, slowly subsiding basins. On the platform a transition from land areas into nearshore quartzose brachiopod coquinas, crinoidal limestones, condensed cephalopod limestones and finally into nodular limestones is observed. The latter often become disintegrated into incipient debris flows which pass into nodular limestone/marl alternations of a shallow basin. Deeper basins with shale sedimentation lack cephalopod limestones. Similar facies types also occur in the late Devonian of the Montagne Noire (France), Rheinisches Schiefergebirge (West Germany), Moravian Karst (Czechoslovakia), Holy Cross Mountains (Poland) and in the early Carboniferous of the Cantabrian Mountains (Spain). Due to strong late Variscan compressional tectonics and limited outcrops, detailed facies patterns could not be mapped in these regions, but the same facies types as in the eastern Anti-Atlas suggest similar coast/platform, slope and shallow basin topographies. During cephalopod limestone deposition water depth on the platforms was in the order of several tens to about one hundred metres, as is inferred from repeated subaerial exposures and distinctive depositional and faunal/floral features. Water depth in the adjacent shallow basins might have reached several hundreds of metres. Cephalopod limestones represent a typical stage in the evolution of geosynclines, characterized by extremely low sedimentation rates (1-5 m m.y. -1). This stage is preceded by deposition of thick neritic clastics and/or carbonates and is succeeded by deposition of deep-water clastics or flysch.

  11. Early evolution of the southern margin of the Neuquén Basin, Argentina: Tectono-stratigraphic implications for rift evolution and exploration of hydrocarbon plays

    NASA Astrophysics Data System (ADS)

    D'Elia, Leandro; Bilmes, Andrés; Franzese, Juan R.; Veiga, Gonzalo D.; Hernández, Mariano; Muravchik, Martín

    2015-12-01

    Long-lived rift basins are characterized by a complex structural and tectonic evolution. They present significant lateral and vertical stratigraphic variations that determine diverse basin-patterns at different timing, scale and location. These issues cause difficulties to establish facies models, correlations and stratal stacking patterns of the fault-related stratigraphy, specially when exploration of hydrocarbon plays proceeds on the subsurface of a basin. The present case study corresponds to the rift-successions of the Neuquén Basin. This basin formed in response to continental extension that took place at the western margin of Gondwana during the Late Triassic-Early Jurassic. A tectono-stratigraphic analysis of the initial successions of the southern part of the Neuquén Basin was carried out. Three syn-rift sequences were determined. These syn-rift sequences were located in different extensional depocentres during the rifting phases. The specific periods of rifting show distinctly different structural and stratigraphic styles: from non-volcanic to volcanic successions and/or from continental to marine sedimentation. The results were compared with surface and subsurface interpretations performed for other depocentres of the basin, devising an integrated rifting scheme for the whole basin. The more accepted tectono-stratigraphic scheme that assumes the deposits of the first marine transgression (Cuyo Cycle) as indicative of the onset of a post-rift phase is reconsidered. In the southern part of the basin, the marine deposits (lower Cuyo Cycle) were integrated into the syn-rift phase, implying the existence of different tectonic signatures for Cuyo Cycle along the basin. The rift climax becomes younger from north to south along the basin. The post-rift initiation followed the diachronic ending of the main syn-rift phase throughout the Neuquén Basin. Thus, initiation of the post-rift stage started in the north and proceeded towards the south, constituting a

  12. Play concepts-northwest Palawan, Philippines

    NASA Astrophysics Data System (ADS)

    Williams, Harold H.

    The offshore area of northwest Palawan, Philippines, contains a number of provenexploration plays. These include • pinnacle reefs developed on Nido carbonate platforms (e.g. Nido, Matinloc, Cadlao);• a seaward horst block reef fairway with large pinnacle reefs (e.g. Malampaya—Camago trend);• early Miocene Galoc Clastic Unit turbidites (e.g. Octon, Galoc); and• four-way dip closures (e.g. West Linapacan, Octon). The recent discovery by Fletcher Challenge Petroleum at Calauit Field has shown a potentialexploration play in deep-water Nido Limestone turbidites. The traditional and, to date, only economically productive play in northwest Palawan has been the Nido Limestone reefs. This paper presents a review of the old play types and presents new untested play types. These new play types include • pre-Nido syn-rift plays;• pre-Nido marine turbidite play: and• mid-Miocene reefs. It also presents new insights into factors controlling reef development on the carbonate platforms where four reef types are now recognized. The Galoc Clastic Unit turbidite play is discussed and new play fairways presented.

  13. Play Sheets. Let's Play! Project.

    ERIC Educational Resources Information Center

    State Univ. of New York, Buffalo. Center for Assistive Technology.

    This collection of play sheets for parents and early intervention personnel was developed by the "Let's Play! Project," a 3-year federally supported project that worked to promote play in infants and toddlers with disabilities through the use of "low-tech" assistive technology. Each single page guide provides guidance to…

  14. Pretend play.

    PubMed

    Weisberg, Deena Skolnick

    2015-01-01

    Pretend play is a form of playful behavior that involves nonliteral action. Although on the surface this activity appears to be merely for fun, recent research has discovered that children's pretend play has connections to important cognitive and social skills, such as symbolic thinking, theory of mind, and counterfactual reasoning. The current article first defines pretend play and then reviews the arguments and evidence for these three connections. Pretend play has a nonliteral correspondence to reality, hence pretending may provide children with practice with navigating symbolic relationships, which may strengthen their language skills. Pretend play and theory of mind reasoning share a focus on others' mental states in order to correctly interpret their behavior, hence pretending and theory of mind may be mutually supportive in development. Pretend play and counterfactual reasoning both involve representing nonreal states of affairs, hence pretending may facilitate children's counterfactual abilities. These connections make pretend play an important phenomenon in cognitive science: Studying children's pretend play can provide insight into these other abilities and their developmental trajectories, and thereby into human cognitive architecture and its development. © 2015 John Wiley & Sons, Ltd.

  15. Role Playing and Skits

    ERIC Educational Resources Information Center

    Letwin, Robert, Ed.

    1975-01-01

    Explores non-scripted role playing, dialogue role playing, sociodrama, and skits as variations of simulation techniques. Provides step-by-step guidelines for conducting such sessions. Successful Meetings, Bill Communications, Inc., 1422 Chestnut Street, Philadelphia, Pa. 19102. Subscription Rates: yearly (US, Canada, Mexico) $14.00; elsewhere,…

  16. Role Playing and Skits

    ERIC Educational Resources Information Center

    Letwin, Robert, Ed.

    1975-01-01

    Explores non-scripted role playing, dialogue role playing, sociodrama, and skits as variations of simulation techniques. Provides step-by-step guidelines for conducting such sessions. Successful Meetings, Bill Communications, Inc., 1422 Chestnut Street, Philadelphia, Pa. 19102. Subscription Rates: yearly (US, Canada, Mexico) $14.00; elsewhere,…

  17. Play, Epideictic and Argument.

    ERIC Educational Resources Information Center

    Hoffman, David C.

    This paper explores the relationship between epideictic and argument, noting that the relationship is a "troublesome" one. The first part moves toward new definitions of epideictic and argument (taking the view that epideictic rises out of human play) and locates argument on the boundary where the play-world meets the "real" or…

  18. Shadow Play

    ERIC Educational Resources Information Center

    Trundle, Kathy Cabe; Hilson, Margilee P.

    2012-01-01

    A bunny rabbit playfully hops across the wall. Then hands realign and fingers shift to make a hawk soar toward the ceiling. Most children have enjoyed the delightful experience of playing with shadow puppets. The authors build on this natural curiosity to help students link shadows to complex astronomical concepts such as seasons. The…

  19. Playful Gaming.

    ERIC Educational Resources Information Center

    Makedon, Alex

    1984-01-01

    Discusses the concept of playful gaming (an idea not expressed fully by either term alone) and uses it as an analytical tool to study the playfulness of games in the context of several social phenomena; i.e., social change, socialization, utopian systems, and educational gaming. An extensive reference list is provided. (MBR)

  20. Why Play?

    ERIC Educational Resources Information Center

    Weininger, O.

    This paper draws together briefly theories and knowledge from research in morphology and cognitive psychology, as well as some hypothetical information from traditional psychiatry, to show the ramifications of play in children's development. Play is defined as any of a wide variety of behaviors through which an individual attempts to discover what…

  1. Shadow Play

    ERIC Educational Resources Information Center

    Trundle, Kathy Cabe; Hilson, Margilee P.

    2012-01-01

    A bunny rabbit playfully hops across the wall. Then hands realign and fingers shift to make a hawk soar toward the ceiling. Most children have enjoyed the delightful experience of playing with shadow puppets. The authors build on this natural curiosity to help students link shadows to complex astronomical concepts such as seasons. The…

  2. Playing Shakespeare.

    ERIC Educational Resources Information Center

    Bashian, Kathleen Ryniker

    1993-01-01

    Describes a yearlong project at 12 Catholic middle schools in the Diocese of Arlington, Virginia, to incorporate the plays of William Shakespeare into the curriculum. Teachers attended university lectures and directed students in performances of the plays. Concludes that Shakespeare can be understood and enjoyed by middle school students. (BCY)

  3. Economic evaluation and comparison of alternative limestone-scrubbing options

    SciTech Connect

    Burnett, T.A.; Torstrick, R.L.; Sudhoff, F.A.

    1982-01-01

    The preliminary-grade economics (accuracy: -15%, +30%) of various alternative limestone scrubbing options (absorber type, with and without forced oxidation, and with and without adipic acid enhancement) are examined using the current design and economic premises established for the continuing series of economic evaluations performed by TVA for EPA. The economics are projected using the Shawnee lime/limestone computer model, which is based on long-term operating data from the EPA Alkali Scrubbing Test Facility at the TVA Shawnee Steam Plant near Paducah, Kentucky. The capital investment for the base-case limestone scrubbing process (500 MW, 3.5% sulfur coal, 1979 NSPS, spray tower, forced oxidation, landfill) is $206/kW. The first-year and levelized annual revenue requirements are 10.59 and 15.09 mills/kWh respectively. Costs for the equivalent limestone scrubbing process using a Turbulent Contact Absorber (TCA) are lower while those for the venturi - spray tower absorber are higher. The forced-oxidation landfill disposal option has a lower capital investment than the unoxidized pond disposal option for all cases studied; however, the first-year and levelized annual revenue requirements are slightly higher for the forced-oxidation landfill process for most coal applications. For the spray tower limestone process to achieve a specified SO/sub 2/ removal efficiency, it is more economical to increase the limestone stoichiometry and minimize the absorber L/G. The use of adipic acid or possibly dibasic acid (DBA) as an additive to enhance SO/sub 2/ removal in the limestone scrubbing process is an economically attractive option. The use of adipic acid remains economically attractive even if both a high unit cost and a high degradation factor for adpic acid are assumbed.

  4. Preschoolers' Thinking during Block Play

    ERIC Educational Resources Information Center

    Piccolo, Diana L.; Test, Joan

    2010-01-01

    Children build foundations for mathematical thinking in early play and exploration. During the preschool years, children enjoy exploring mathematical concepts--such as patterns, shape, spatial relationships, and measurement--leading them to spontaneously engage in mathematical thinking during play. Block play is one common example that engages…

  5. Mine water treatment with limestone for sulfate removal.

    PubMed

    Silva, Adarlêne M; Lima, Rosa M F; Leão, Versiane A

    2012-06-30

    Limestone can be an option for sulfate sorption, particularly from neutral mine drainages because calcium ions on the solid surface can bind sulfate ions. This work investigated sulfate removal from mine waters through sorption on limestone. Continuous stirred-tank experiments reduced the sulfate concentration from 588.0mg/L to 87.0mg/L at a 210-min residence time. Batch equilibrium tests showed that sulfate loading on limestone can be described by the Langmuir isotherm, with a maximum loading of 23.7mg/g. Fixed-bed experiments were utilized to produce breakthrough curves at different bed depths. The Bed Depth Service Time (BDST) model was applied, and it indicated sulfate loadings of up to 20.0gSO(4)(2-)/L-bed as the flow rate increased from 1 to 10mL/min. Thomas, Yoon-Nelson and dose-response models, predicted a maximum particle loading of 19mg/g. Infrared spectrometry indicated the presence of sulfate ions on the limestone surface. Sulfate sorption on limestone seems to be an alternative to treating mine waters with sulfate concentrations below the 1200-2000mg/L range, where lime precipitation is not effective. In addition, this approach does not require alkaline pH values, as in the ettringite process. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Modifying the properties of finely ground limestone by tumbling granulation

    NASA Astrophysics Data System (ADS)

    Macho, Oliver; Eckert, Maroš; Tomášová, Barbora; Peciar, Peter; Ščasný, Martin; Fekete, Roman; Peciar, Marián

    2016-06-01

    Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.

  7. Manganese and limestone interactions during mine water treatment.

    PubMed

    Silva, A M; Cruz, F L S; Lima, R M F; Teixeira, M C; Leão, V A

    2010-09-15

    Manganese removal from mining-affected waters is an important challenge for the mining industry. Addressed herein is this issue in both batch and continuous conditions. Batch experiments were carried out with synthetic solutions, at 23+/-2 degrees C, initial pH 5.5 and 8.3 g limestone/L. Similarly, continuous tests were performed with a 16.5 mg/L Mn(2+) mine water, at 23 degrees C, initial pH 8.0 and 20.8 g limestone/L. Calcite limestone gave the best results and its fine grinding proved to the most effective parameter for manganese removal. In either synthetic solutions or industrial effluents, the final manganese concentration was below 1 mg/L. A change in limestone surface zeta potential is observed after manganese removal and manganese carbonate formation was suggested by IR spectroscopy. The conclusion is that limestone can remove manganese from industrial effluents for values that comply with environmental regulations. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Exploring Young People's Civic Identities through Gamification: A Case Study of Finnish, Swedish and Norwegian Adolescents Playing a Social Simulation Game

    ERIC Educational Resources Information Center

    Eränpalo, Tommi

    2014-01-01

    This article is based on a case study where groups of Finnish, Swedish and Norwegian young people played a simulation game that stimulated collective deliberation on social issues. The game has been designed to provoke students to deliberate and to reflect on social problems relating to issues of citizenship and democracy. The analysis of the…

  9. Exploring employment readiness through mock job interview and workplace role-play exercises: comparing youth with physical disabilities to their typically developing peers.

    PubMed

    Lindsay, Sally; McDougall, Carolyn; Sanford, Robyn; Menna-Dack, Dolly; Kingsnorth, Shauna; Adams, Tracey

    2015-01-01

    To assess performance differences in a mock job interview and workplace role-play exercise for youth with disabilities compared to their typically developing peers. We evaluated a purposive sample of 31 youth (15 with a physical disability and 16 typically developing) on their performance (content and delivery) in employment readiness role-play exercises. Our findings show significant differences between youth with disabilities compared to typically developing peers in several areas of the mock interview content (i.e. responses to the questions: "tell me about yourself", "how would you provide feedback to someone not doing their share" and a problem-solving scenario question) and delivery (i.e. voice clarity and mean latency). We found no significant differences in the workplace role-play performances of youth with and without disabilities. Youth with physical disabilities performed poorer in some areas of a job interview compared to their typically developing peers. They could benefit from further targeted employment readiness training. Clinicians should: Coach youth with physical disability on how to "sell" their abilities to potential employers and encourage youth to get involved in volunteer activities and employment readiness training programs. Consider using mock job interviews and other employment role-play exercises as assessment and training tools for youth with physical disabilities. Involve speech pathologists in the development of employment readiness programs that address voice clarity as a potential delivery issue.

  10. Exploring Young People's Civic Identities through Gamification: A Case Study of Finnish, Swedish and Norwegian Adolescents Playing a Social Simulation Game

    ERIC Educational Resources Information Center

    Eränpalo, Tommi

    2014-01-01

    This article is based on a case study where groups of Finnish, Swedish and Norwegian young people played a simulation game that stimulated collective deliberation on social issues. The game has been designed to provoke students to deliberate and to reflect on social problems relating to issues of citizenship and democracy. The analysis of the…

  11. Learning English Speaking through Mobile-Based Role-Plays: The Exploration of a Mobile English Language Learning App Called Engage

    ERIC Educational Resources Information Center

    Yang, Bowen; Zhou, Shijun; Ju, Weijie

    2013-01-01

    Engage is a new form of mobile application that connects students studying English with teachers in real-time via their smartphones. Students receive target language through preparation dialogues, and then apply it to a role-play with a teacher. The conceptualization and development of Engage follows the user-centred design approach; and the…

  12. Origin and genesis of fracture porosity in Viola Limestone (Ordovician)

    SciTech Connect

    Allen, G.D.

    1983-03-01

    Analysis of surface exposures of the Viola Limestone is important to understanding Viola oil and gas production trends in the Marietta basin of southern Oklahoma. Surface exposures of the Viola Limestone in the Arbuckle Mountains and Criner Hills of Oklahoma indicate a critical dependence of fracture development on structural position and lithology. Maximum fracturing occurs in tensional zones along fold crests, rather than in areas characterized by intense compressional stress. Fracturing also appears to be related to lithology. The basal, cherty unit has a fracture density approximately two to four times greater than that of the upper, more calcareous units. These relationships could be important to understanding oil and gas occurrence in the Viola Limestone, because the same controls may dictate distribution of fracture porosity in the subsurface.

  13. Playing the Field(s): An Exploration of Change, Conformity and Conflict in Girls' Understandings of Gendered Physicality in Physical Education

    ERIC Educational Resources Information Center

    Hills, Laura A.

    2006-01-01

    This paper draws on data from a year-long ethnographic study of a group of 12- to 13-year-old girls that explored the processes through which they negotiated gendered physicality within the context of physical education. Bourdieu's concepts of habitus and social fields and McNay's extension of his work underpin a discussion of three contexts where…

  14. Playing the Field(s): An Exploration of Change, Conformity and Conflict in Girls' Understandings of Gendered Physicality in Physical Education

    ERIC Educational Resources Information Center

    Hills, Laura A.

    2006-01-01

    This paper draws on data from a year-long ethnographic study of a group of 12- to 13-year-old girls that explored the processes through which they negotiated gendered physicality within the context of physical education. Bourdieu's concepts of habitus and social fields and McNay's extension of his work underpin a discussion of three contexts where…

  15. Sweet Play

    ERIC Educational Resources Information Center

    Leung, Shuk-kwan S.; Lo, Jane-Jane

    2010-01-01

    This article features Sweet play math, a "math by the month" activity that involves decorating and making sugar cubes. Teachers may want to substitute straws, paper squares, alphabet blocks, or such commercially made manipulatives as Unifix[R] cubes for the real sweets. Given no allergy concerns, teachers and students alike would enjoy some sweet…

  16. Game playing.

    PubMed

    Rosin, Christopher D

    2014-03-01

    Game playing has been a core domain of artificial intelligence research since the beginnings of the field. Game playing provides clearly defined arenas within which computational approaches can be readily compared to human expertise through head-to-head competition and other benchmarks. Game playing research has identified several simple core algorithms that provide successful foundations, with development focused on the challenges of defeating human experts in specific games. Key developments include minimax search in chess, machine learning from self-play in backgammon, and Monte Carlo tree search in Go. These approaches have generalized successfully to additional games. While computers have surpassed human expertise in a wide variety of games, open challenges remain and research focuses on identifying and developing new successful algorithmic foundations. WIREs Cogn Sci 2014, 5:193-205. doi: 10.1002/wcs.1278 CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. © 2014 John Wiley & Sons, Ltd.

  17. Water Play

    ERIC Educational Resources Information Center

    Cline, Jane E.; Smith, Brandy A.

    The inclusion of activities to develop sensory awareness, spatial thinking, and physical dexterity, operationalized through hands-on science lessons such as water play, have long been part of early childhood education. This practical article addresses Next Generation Science Standards K-2 ETS1-3 and K-2 ETS1-2 by having four-year-old…

  18. Play School

    ERIC Educational Resources Information Center

    Rich, Jennifer L.

    2004-01-01

    This article describes Fifth Dimension, an after-school program which mixes play and computer games to improve the education and social skills of mostly poor, disadvantaged kids. Although Fifth Dimension seems tailor-made for a poor, rural community, its roots are urban. The after-school program was founded by a group of researchers in San Diego…

  19. Playing Teacher.

    ERIC Educational Resources Information Center

    Gilbert, Juan E.

    The acceptance of animation technologies is increasing. Video games, such as Sony PlayStation (SONY, 2002), have become part of the culture for young people from kindergarten through undergraduate school. Animation technologies have been implemented into educational systems in the form of animated pedagogical agents (Johnson, 2000). The research…

  20. Sweet Play

    ERIC Educational Resources Information Center

    Leung, Shuk-kwan S.; Lo, Jane-Jane

    2010-01-01

    This article features Sweet play math, a "math by the month" activity that involves decorating and making sugar cubes. Teachers may want to substitute straws, paper squares, alphabet blocks, or such commercially made manipulatives as Unifix[R] cubes for the real sweets. Given no allergy concerns, teachers and students alike would enjoy some sweet…

  1. Effect of SO2 Dry Deposition on Porous Dolomitic Limestones

    PubMed Central

    Olaru, Mihaela; Aflori, Magdalena; Simionescu, Bogdana; Doroftei, Florica; Stratulat, Lacramioara

    2010-01-01

    The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain) used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100) and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA) were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.

  2. The Ançã limestones, Coimbra, Portugal

    NASA Astrophysics Data System (ADS)

    Quinta-Ferreira, Mário; Gil Catarino, Lídia; Delgado Rodrigues, José

    2016-04-01

    Ançã is located in the Lusitanian Basin (western Meso-Cenozoic sedimentary basin), in the municipality of Cantanhede, close to Coimbra, Portugal. This constitutes the northernmost Dogger (Bajocian) limestone sequence in Portugal. The use of the Ançã limestones is documented since the Roman occupation of the Iberian Peninsula. It was used for the construction of houses, palaces, churches, fine sculptures, carving, paving and for the production of lime. These limestones vary from white and very soft varieties, with very high porosity used for sculpture and carving to white and hard varieties used for masonry and as aggregates and to white to bluish with low porosity and high strength varieties, mainly used for paving. The softer and whiter variety is worldwide known as Ançã Stone (Pedra de Ançã) exhibiting a porosity of 26-29 %. It became famous after being largely used by Coimbra most famous Renaissance sculptors like João de Ruão and Nicolau de Chanterenne. The Pedra de Ançã was used mainly in the region of Coimbra, but also in several other places in Portugal, in Santiago de Compostela, Spain, and Brazil. Some examples of heritage in Coimbra using the Pedra de Ançã are the renaissance portal of the Saint Cross Church, the tombs of the first two Portuguese kings located in this church, the altar of the Saint Cross Church or of the Old Cathedral, or in sculptures at the University of Coimbra. It is quite prone to deteriorate when exposed to atmospheric agents and to soluble salts, mainly due to its high porosity. Deteriorated surfaces needing treatment constitute difficult conservation problems, especially when consolidation and protection treatments are required. The less porous varieties of the Ançã limestones (< 20 % porosity) were mainly used for masonry, paving and production of lime. The royal Palace of Buçaco is a remarkable masonry building constructed at the end of the XIX century with the less porous varieties of the Ançã limestones

  3. Leaching of clay minerals in a limestone environment

    USGS Publications Warehouse

    Carroll, D.; Starkey, H.C.

    1959-01-01

    Water saturated with CO2 at about 25??C was percolated through mixed beds of limestone or marble fragments and montmorillonite, "illite" and kaolinite in polyethylene tubes for six and fortyfive complete runs. The leachates were analysed for SiO2, A12O3 and Fe2O3, but only SiO2 was found. The minerals lost SiO2 in this order: montmorillonite > kaolinite > "illite". The differential removal of SiO2 during the short period of these experiments suggests a mechanism for the accumulation of bauxite deposits associated with limestones. ?? 1959.

  4. Novel Hydroxyapatite Coatings for the Conservation of Marble and Limestone

    NASA Astrophysics Data System (ADS)

    Naidu, Sonia

    Marble and limestone are calcite-based materials used in the construction of various structures, many of which have significant artistic and architectural value. Unfortunately, due to calcite's high dissolution rate, these stones are susceptible to chemically-induced weathering in nature. Limestone, due to its inherent porosity, also faces other environmental weathering processes that cause weakening from disintegration at grain boundaries. The treatments presently available are all deficient in one way or another. The aim of this work is to examine the feasibility of using hydroxyapatite (HAP) as a novel protective coating for marble and limestone, with two goals: i) to reduce acid corrosion of marble and ii) to consolidate physically weathered limestone. The motivation for using HAP is its low dissolution rate and structural compatibility with calcite. Mild, wet chemical synthesis routes, in which inorganic phosphate-based solutions were reacted with marble and limestone, alone and with other precursors, were used to produce HAP films. Film nucleation, growth and phase evolution were studied on marble to understand film formation and determine the optimal synthesis route. An acid resistance test was developed to investigate the attack mechanism on marble and quantify the efficacy of HAP-based coatings. Film nucleation and growth were dependent on substrate surface roughness and increased with calcium and carbonate salt additions during synthesis. Acid attack on marble occurred via simultaneous dissolution at grain boundaries, twin boundaries and grain surfaces. HAP provided intermediate protection against acid attack, when compared to two conventional treatments. Its ability to protect the stone from acid was not as significant as predicted from dissolution kinetics and this was attributed to incomplete coverage and residual porosity within the film, arising from its flake-like crystal growth habit, which enabled acid to access the underlying substrate. The

  5. Major Oil Plays In Utah And Vicinity

    SciTech Connect

    Thomas Chidsey

    2007-12-31

    Jurassic Twin Creek Limestone, or a low-permeability zone at the top of the Nugget. The Nugget Sandstone thrust belt play is divided into three subplays: (1) Absaroka thrust - Mesozoic-cored shallow structures, (2) Absaroka thrust - Mesozoic-cored deep structures, and (3) Absaroka thrust - Paleozoic-cored shallow structures. Both of the Mesozoic-cored structures subplays represent a linear, hanging wall, ramp anticline parallel to the leading edge of the Absaroka thrust. Fields in the shallow Mesozoic subplay produce crude oil and associated gas; fields in the deep subplay produce retrograde condensate. The Paleozoic-cored structures subplay is located immediately west of the Mesozoic-cored structures subplays. It represents a very continuous and linear, hanging wall, ramp anticline where the Nugget is truncated against a thrust splay. Fields in this subplay produce nonassociated gas and condensate. Traps in these subplays consist of long, narrow, doubly plunging anticlines. Prospective drilling targets are delineated using high-quality, two-dimensional and three-dimensional seismic data, forward modeling/visualization tools, and other state-of-the-art techniques. Future Nugget Sandstone exploration could focus on more structurally complex and subtle, thrust-related traps. Nugget structures may be present beneath the leading edge of the Hogsback thrust and North Flank fault of the Uinta uplift. The Jurassic Twin Creek Limestone play in the Utah/Wyoming thrust belt province has produced over 15 million barrels (2.4 million m{sup 3}) of oil and 93 billion cubic feet (2.6 billion m{sup 3}) of gas. Traps form on discrete subsidiary closures along major ramp anticlines where the low-porosity Twin Creek is extensively fractured. Hydrocarbons in Twin Creek reservoirs were generated from subthrust Cretaceous source rocks. The seals for the producing horizons are overlying argillaceous and clastic beds, and non-fractured units within the Twin Creek. The Twin Creek Limestone thrust

  6. Oxic limestone drains for treatment of dilute, acidic mine drainage

    USGS Publications Warehouse

    Cravotta, Charles A.

    1998-01-01

    Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metals and the effect of pH and Fe‐ and Al‐hydrolysis products on the rate of limestone dissolution. The influent was acidic and relatively dilute (pH <4; acidity < 90 mg‐L‐1 ) but contained 1‐4 mg‐L‐1 Of O2 , Fe3+ , A13+ , and Mn2+ . The total retention time in the OLDs ranged from 1.0 to 3.1 hours. Effluent remained oxic (02 >1 mg‐L‐1 ) but was near neutral (pH = 6.2‐7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs. The hydrous oxides, nominally Fe(OH)3 and AI(OH)3, were visible as loosely bound, orange‐yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)3 and AI(OH)3 particles were transported downflow. During the first 6 months of the experiment, Mn 2+ was transported conservatively through the OLDs; however, during the second 6 months, concentrations of Mn in effluent decreased by about 50% relative to influent. The accumulation of hydrous oxides and elevated pH (>5) in the downflow part of the OLDs promoted sorption and coprecipitation of Mn as indicated by its enrichment relative to Fe in hydrous‐oxide particles and coatings on limestone. Despite thick (~1 mm) hydrous‐oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within the OLD where the limestone was not coated. The rate of limestone dissolution decreased with increased residence time, pH, and concentrations of Ca2+ and HCO3‐ and decreased PCO2. The following overall reaction shows alkalinity as

  7. Play, experimentation and creativity.

    PubMed

    Caper, R

    1996-10-01

    Beginning with Klein's description of a psychotic boy's inability to play, published in 1930, the author explores the relationship between play and symbol-formation, and the use of play by children and adults as a serious type of experimentation by means of which one learns about the internal and external worlds. In this view, play is a way of externalising fantasies originating in one's inner world so they may be seen and learned about. Play is also a vehicle of projection, a fact that allows one to use it to assess the impact of one's inner world on the external world, especially on the minds of one's objects. In this way, playing becomes a way of probing external reality as well. This type of learning depends on the ability to keep internal and external realities distinct even while projecting the former into the latter. In psychotic states, this ability is lost, and the psychotic patient's projections, instead of being usable as a form of playful experimentation, lead to delusions and claustrophobic anxiety. A brief clinical vignette is presented to illustrate these points. The author then explores the application of these ideas to an understanding of artistic creativity, and makes some observations about possible underlying unities between play, scientific experimentation and artistic creativity.

  8. Geochemical and mineralogical characteristics of percolates and its evaporates from Technosols before and after limestone filler stabilisation.

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Garcia-Lorenzo, Maria Luz; Hernandez-Cordoba, Manuel

    2017-04-01

    The chemistry of waters is recognized as a relevant monitoring tool when assessing the adverse effects of acid mine drainage. The weathering of sulphide minerals produces a great variety of efflorescences of soluble sulphate salts. These minerals play an important role for environmental pollution, since they can be either a sink or a source for acidity and trace elements. This communication deals with the leachability of potentially toxic elements (PTE) eluting from technosols formed from soils affected by mining activities and limestone filler. A total of three contaminated soils affected by opencast mining were selected and mixed with limestone filler at three percentages: 10 %, 20 % and 30 %, providing nine stabilised samples. These samples were stored in containers and moistened simulating rainfall. The percolates obtained were collected, and the PTEs content (As, Cd, Cu, Fe, Pb and Zn) was determined. Evaporation-precipitation experiments were carried out in these waters, and the mineralogical composition of efflorescences was evaluated. The study area is heavily polluted as a result of historical mining and processing activities, producing large amount of wastes, characterised by high trace elements content and acidic pH. The results obtained for the percolates after the rain episode showed that, before the stabilization approach, waters had an acidic pH, high electrical conductivity and high PTEs content. When these soils were mixed with 10, 20 and 30 % of limestone filler, the pH was neutral and the soluble trace element content strongly decreased, being under the detection limit when limestone percentage was 20 % and 30 %. The mineralogical composition of efflorescences before the stabilisation approach showed that predominant minerals were copiapite, followed by gypsum and bilinite. Other soluble sulphates were determined in lower percentage, such as hexahydrite, halotriquite or pickeringite. After the mixing with 10 % of limestone filler, the evaporates

  9. Depositional and tectonic interpretation of limestone insoluble residues from modern and ancient carbonate rocks, Caribbean and southeastern United States

    SciTech Connect

    Isphording, W.C.; Bundy, M.E.; George, S.M.

    1995-10-01

    Mineral compositions have long been used as indicators of the provenance and tectonic setting of source rocks for sandstones and shales. Extraction of the same information from limestones is less common because of the general paucity of the non-carbonate phase and the greater processing time that is required to concentrate the frequently encountered small quantities of detrital (and authigenic) minerals. The insoluble component, however, contains a great deal of valuable information and should not be ignored. The clays and other insoluble minerals in limestones from southeastern United States and the Caribbean region, for example, clearly reflect the volcanic activity that was associated with formation of the Mid-Atlantic Ridge rift system and the opening of the Atlantic Ocean and Gulf of Mexico. Similarly, major periods of orogeny during the Paleozoic and Mesozoic have left their signature, even in carbonate rocks that originated far from the sites where uplift was taking place. In other cases, the insoluble residue component clearly manifests periods of quiescence in adjacent land areas or testifies to the airborne transport of insoluble components from sources as far distant as the Saharan Desert of Africa. Similarly, insoluble components have convincingly shown that the origin of the extensive bauxite deposits found in Jamaican limestones are the result of alteration of interbedded volcanic ash units and have not resulted from accumulation of the detritus in the limestones. Residue analysis in Gulf Coast limestones can be successfully used for subsurface identification and correlation of carbonate units in the exploration for hydrocarbons, to reconstruct sedimentary environments, to identify missing sections, and to identify paraconformable realtionships between adjacent carbonate units that are otherwise similar in appearance. The latter is especially useful where extensive recrystallization has taken place and fossils have been destroyed.

  10. View of the main entrance with basrelief limestone panel designed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of the main entrance with bas-relief limestone panel designed by C. Paul Jennwein upon which is inscribed "Lege Atque Ordine Omnia Fiunt" (translated as by law and order all is accomplished) - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  11. Geology of the Limestone Hills, Broadwater County, Montana

    USGS Publications Warehouse

    Ruppel, Edward Thompson

    1950-01-01

    The Limestone Hills, a natural topographic unit having an area of about 16 square miles, are situated a few miles west and southwest of Townsend, Broadwater County, Montana. They are composed of pre-Cambrian, Paleozoic, and Mesozoic sedimentary rocks i

  12. Soil respiration patterns and controls in limestone cedar glades

    USGS Publications Warehouse

    Cartwright, Jennifer M.; Hui, Dafeng

    2015-01-01

    Soil depth, SOM, and vegetation cover were important drivers of Rs in limestone cedar glades. Seasonal Rs patterns reflected those for mesic temperate grasslands more than for semi-arid ecosystems, in that Rs primarily tracked temperature for most of the year.

  13. Curved limestone wall at east end of rail yard. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Curved limestone wall at east end of rail yard. Note cut off valves at base of stump in right foreground, and utility tunnel in middle distance, superindent's house at right, looking NW. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  14. The influence of additives on rheological properties of limestone slurry

    NASA Astrophysics Data System (ADS)

    Jaworska, B.; Bartosik, A.

    2014-08-01

    Limestone slurry appears in the lime production process as the result of rinsing the processed material. It consists of particles with diameter smaller than 2 mm and the water that is a carrier of solid fraction. Slurry is directed to the settling tank, where the solid phase sediments and the excess water through the transfer system is recovered for re-circulation. Collected at the bottom of the tank sludge is deposited in a landfill located on the premises. Rheological properties of limestone slurry hinder its further free transport in the pipeline due to generated flow resistance. To improve this state of affairs, chemical treatment of drilling fluid, could be applied, of which the main task is to give the slurry properties suitable for the conditions encountered in hydrotransport. This treatment consists of applying chemical additives to slurry in sufficient quantity. Such additives are called as deflocculants or thinners or dispersants, and are chemical compounds which added to aqueous solution are intended to push away suspended particles from each other. The paper presents the results of research allowing reduction of shear stress in limestone slurry. Results demonstrate rheological properties of limestone slurry with and without the addition of modified substances which causes decrease of slurry viscosity, and as a consequence slurry shear stress for adopted shear rate. Achieving the desired effects increases the degree of dispersion of the solid phase suspended in the carrier liquid and improving its ability to smooth flow with decreased friction.

  15. Thermal decomposition of limestone and gypsum by solar energy

    SciTech Connect

    Salman, O.A.; Khraishi, N. )

    1988-01-01

    The thermal decomposition of limestone and gypsum by concentrated solar radiation was studied. A 1.5-kW solar furnace was used to obtain the required reaction temperature. Maximum conversions of 65% and 38% were obtained for CaCO{sub 3} and CaSO{sub 4}{center dot}H{sub 2}O decomposition, respectively.

  16. Detail view to show one of the limestone relief panels ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view to show one of the limestone relief panels depicting one of the agencies of the Commerce Department, here the Lighthouse Service - United States Department of Commerce, Bounded by Fourteenth, Fifteenth, and E streets and Constitution Avenue, Washington, District of Columbia, DC

  17. Flora of Chihuahuan desertscrub on limestone in northeastern Sonora, Mexico

    Treesearch

    Thomas R. Van Devender; Ana Lilia Reina-Guerrero; J. Jesus. Sanchez-Escalante

    2013-01-01

    Transects were done in desertscrub on limestone to characterize the flora of the westernmost Chihuahuan Desert. Most of the sites (15) were in the Municipios of Agua Prieta and Naco in northeastern Sonora, with single sites near Ascensión, northwestern Chihuahua and east of Douglas in southeastern Arizona. A total of 236 taxa were recorded on transects. Dicot perennial...

  18. The Solnhofen Limestone: A stony heritage of many uses

    NASA Astrophysics Data System (ADS)

    Kölbl-Ebert, Martina; Kramar, Sabina; Cooper, Barry J.

    2016-04-01

    High above the valley of the River Altmühl (Bavaria, Germany), between Solnhofen to the west and Kelheim to the east, numerous quarries give access to thinly plated limestone from the Upper Jurassic, some 150 million years before the present. The main quarry areas lie around the town of Eichstätt and between the villages of Solnhofen, Langenaltheim and Mörnsheim. Here limestone slabs have been quarried for several hundred years, some even in Roman times. Solnhofen Limestone is famous worldwide; not only because it is a beautiful building stone of high quality, but also because of the exceptionally well-preserved fossils it contains -among them the early bird Archaeopteryx. The quarry industry between Solnhofen and Eichstätt has shaped a cultural landscape, with old and new quarries sunk into the plain and numerous spoil heaps rising above it, for the rock is not all economically useful. But many of the spoil heaps and the old quarries are environmentally protected as they provide a habitat for some rare plants and animals. It is not necessary to cut the Solnhofen Limestone with a saw: it is split by hand into thin and even slabs or sheets which are used for flagstones and wall covers, which since centuries are sold world-wide. Locally it also serves as roof tiles for traditional houses. Thick slabs of especially fine quality may be found near Solnhofen and Mörnsheim and are used for lithography printing.

  19. 44. Tube conveyors carry ore, coke and limestone to blast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Tube conveyors carry ore, coke and limestone to blast furnaces "B" and "C". Ore bridges to left, passenger elevator penthouse immediately to left of conveyor; gas stack and furnace "A" to right. Looking north - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

  20. 14. A VIEW SOUTHEAST OF A PORTION OF THE LIMESTONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. A VIEW SOUTHEAST OF A PORTION OF THE LIMESTONE ABUTMENT, THE UNDERSIDE OF THE INCLINED END POST AND A PLATE USED TO ATTACH THE STRUCTURE TO THE ABUTMENT. - Wells County Bridge No. 74, Spanning Rock Creek Ditch at County Road 400, Bluffton, Wells County, IN

  1. Trapping models for the Lower Silurian Medina Sandstone Group - A comparison of trapping styles and exploration methodology for both deep and shallow medina plays in the Appalachian basin

    SciTech Connect

    Zagorski, W.A. )

    1991-08-01

    The Lower Silurian Medina Sandstone Group has been a major oil and gas producer in the Appalachian basin since the late 1800s and remains a primary objective in parts of New York, Ohio, and Pennsylvania. Although classified as a stratigraphic trap, production from the Medina is obtained from a wide variety of trapping conditions ranging from pure stratigraphic to structural stratigraphic in the shallower producing areas of the Medina to deep basin (i.e., Elmworth field, western Canada) trapping in the deeper producing regions of strategies must be employed for optimum prospect development and maximum economic success ratios. Several producing areas of the Medina are presented to compare and contrast these various trapping mechanisms together with suggested exploration models applicable to each trap type.

  2. Comparison of magnetic hysteresis parameters of unremagnetized and remagnetized limestones

    NASA Astrophysics Data System (ADS)

    Channell, J. E. T.; McCabe, C.

    1994-03-01

    For white magnetite-bearing Mesozoic pelagic limestones from Italy which carry a 'primary' magnetization, the values of saturation remanence/saturation magnetization (Mrs/Ms) and coercivity of remanence/coercive force (Hcr/Hc) generally lie in the pseudo-single domain (PSD) field of the Day et al. (1977) plot. The logarithmic plot of Mrs/MS against Hcr/Hc gives a straight line (R = 0.814) with slope and intercept close to the empirical mixing line of Parry (1982) for single domain (SD) and multidomain (MD) magnetite. For one of the white pelagic limestone formations (Maiolica Formation), samples with hysteresis ratios closer to the MD field display increased paramagnetic susceptibility and are from the upper part of the formation characterized by increased detrital clay. We therefore associate the increased MD magnetite with increased detrital influx. For pinkish and reddish varieties of the Italian pelagic limesones, the presence of hematite is manifest by high saturation fields, a wide range of Hcr/Hc, and 'wasp-waisted' hysteresis loops attributed to the mixing of magnetite and high-coercivity authigenic hematite. The hysteresis for a collection of Paleozoic and Mesozoic remagnetized magnetite-bearing limestones from Britain, Nevada, Alaska and the Appalachians lie mainly outside the PSD field and appear to follow a power law trend. Following Jackson et al. (1993), the high values of Hcr/Hc and the characteristically 'wasp-waisted' hysteresis loops can be interpreted in terms of a fine-grained subspherical high-coercivity SD magnetite mixed with a high proportion of superparamagnetic magnetite. The slope and intercept of the power law relationship for Mrs/Ms and Hcr/Hc in the remagnetized limestones are distinct from those observed for the Italian limestones, and may provide a means of fingerprinting magnetite of 'primary' as opposed to diagenetic origin.

  3. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States. Results of exposures, 1984--1988

    SciTech Connect

    Reimann, K.J.

    1991-09-01

    Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.

  4. Vascular plant checklist of the Chimney Spring and Limestone Flats Prescribed Burning Study Areas within ponderosa pine experimental forests in northern Arizona

    Treesearch

    Catherine Scudieri; James F. Fowler; Carolyn Hull Sieg; Laura Williams; Sally M. Haase

    2008-01-01

    This paper presents a vascular plant species list for two sites that are part of a long-term study exploring the effects of varying fire intervals on forest characteristics including the abundance and composition of understory vegetation. The Chimney Spring study area is on the Fort Valley Experimental Forest near Flagstaff, AZ, and the Limestone Flats study area is on...

  5. Vascular plant checklist of the Chimney Spring and Limestone Flats prescribed burning study areas within ponderosa pine experimental forests in northern Arizona (P-53)

    Treesearch

    Catherine Scudieri; James Fowler; Carolyn Hull Sieg; Laura Williams; Sally Haase

    2008-01-01

    This paper presents a vascular plant species list for two sites that are part of a long-term study exploring the effects of varying fire intervals on forest characteristics including the abundance and composition of understory vegetation. The Chimney Spring study area is on the Fort Valley Experimental Forest near Flagstaff, AZ and the Limestone Flats study area is on...

  6. Playing the role of a science student: Exploring the meaning of the science student role and its relationship to students' identification in science

    NASA Astrophysics Data System (ADS)

    Shanahan, Marie-Claire

    Learning and succeeding in school is a process that involves the whole person and is situated within the social context of the school and classroom. As science educators, this means exploring how and why individuals come to see themselves as science students. To examine this process, I have used a framework of role identity theory, which takes the perspective that in all situations there are roles that carry with them behavioural and attitudinal expectations. Individuals develop role identities when they are able to match their self-perceptions with the meanings of the role. This study explores the meaning of the science student role and its impact on student identification in science using a three-phase, mixed-methods design. In Phase 1, an exploratory qualitative phase, student responses ( n = 95) were collected through open-ended questionnaires and follow-up interviews and used to create a framework for understanding the role and the expectations associated with it. Phase 2 used this framework to create a questionnaire asking students (n = 129) to compare the expectations in science to those in other classes. Phase 3 took the role components from Phase 2 and asked students (n = 292) to rate themselves and ideal science students with respect to these expectations. Regression was used to understand how students' comparisons of themselves to the role related to their definitions of themselves as science students and to their future plans in science. The results suggest a clearly defined science student role that is dominated by traditional understandings of scientific attitudes. The Phase 2 results suggest that the expectations can be represented by four subscales: intelligence, scientific mindedness, scientific skill, and appropriate behaviour. The results of Phase 3 demonstrate that student ratings of themselves as intelligent and scientifically minded were strong predictors of their self-reported identification with science, accounting for almost half of the

  7. Quarry Quest. A Field Trip Guide to the Indiana Limestone District, Monroe and Lawrence Counties, Indiana.

    ERIC Educational Resources Information Center

    Shewmaker, Sherman N.

    This guide provides information for planning a field trip to the Indiana Limestone District. This district, located in Monroe and Lawrence Counties, Indiana, is responsible for material that has dominated the building-limestone market in the United States for nearly a century. A few of the many well-known buildings using Indiana limestone are the…

  8. Limestone dissolution in modeling of slurry scrubbing for flue-gas desulfurization

    SciTech Connect

    Gage, C.L.

    1989-01-01

    Batch limestone dissolution experiments were carried out in a pH stat apparatus at 550C with CO{sub 2} sparging and dissolved sulfite. Particle size distribution, utilization, sulfite in solution, limestone type, and the approach to calcite equilibrium were all found to contribute to the limestone reactivity. In the absence of sulfite limestone dissolution was controlled solely by mass transfer. A surface rate correlation was developed which accounted for observed inhibition by an inverse dependence on calcium sulfite concentration at the limestone surface. A computer code which accounted for mass transfer with surface kinetics was tested against experimental observations of four limestone types. Changes in pH and the concentrations of calcium, carbonate, sulfite, sulfate, and adipic acid were accurately modeled. An overall slurry scrubber model was expanded to predict limestone reactivity from particle size and solution effects. This model predicts scrubber performance and hold tank compositions from the chemistry of the limestone slurry process. Additional subroutines were written to predict particle size distributions from sieve data using the log gamma density function. The expanded model was tested against a limestone type and grind study which investigated utilizations of four limestone types at ten different grinds. The expanded Slurry Scrubber Model was able to predict both SO{sub 2} removal and hold tank compositions of the limestone study. The effects of limestone type were handled through changes in the surface rate parameter. Within a given type the effects of grind and utilization were well modeled.

  9. Mid-continent natural gas reservoirs and plays

    SciTech Connect

    Bebout, D.G. )

    1993-09-01

    Natural gas reservoirs of the mid-continent states of Oklahoma, Kansas, and Arkansas (northern part) have produced 103 trillion cubic ft (tcf) of natural gas. Oklahoma has produced the most, having a cumulative production of 71 tcf. The major reservoirs (those that have produced more than 10 billion ft[sup 3]) have been identified and organized into 28 plays based on geologic age, lithology, and depositional environment. The Atlas of Major Midcontinent Gas Reservoirs, published in 1993, provides the documentation for these plays. This atlas was a collaborative effort of the Gas Research Institute; Bureau of Economic Geology. The University of Texas at Austin; Arkansas Geological Commission; Kansas Geological survey; and Oklahoma Geological Survey. Total cumulative production for 530 major reservoirs is 66 tcf associated and nonassociated gas. Oklahoma has the highest production with 39 tcf from 390 major reservoirs, followed by Kansas with 26 tcf from 105 major reservoirs. Most of the mid-continent production is from Pennsylvanian (46%) and Permian (41%) reservoirs; Mississippian reservoirs account for 10% production, and lower Paleozoic reservoirs, 3%. The largest play by far is the Wolfcampian Shallow Shelf Carbonate-Hugoton Embayment play with 25 tcf cumulative production, most of which is from the Hugoton and Panoma fields in Kansas and Guymon-Hugoton gas area in Oklahoma. A total of 53% of the mid-continent gas production is from dolostone and limestone reservoirs; 39% is from sandstone reservoirs. The remaining 8% is from chert conglomerate and granite-wash reservoirs. Geologically based plays established from the distribution of major gas reservoirs provide important support for the extension of productive trends, application of new resource technology to more efficient field development, and further exploration in the mid-continent region.

  10. Noise suppression using preconditioned least-squares prestack time migration: application to the Mississippian limestone

    NASA Astrophysics Data System (ADS)

    Guo, Shiguang; Zhang, Bo; Wang, Qing; Cabrales-Vargas, Alejandro; Marfurt, Kurt J.

    2016-08-01

    Conventional Kirchhoff migration often suffers from artifacts such as aliasing and acquisition footprint, which come from sub-optimal seismic acquisition. The footprint can mask faults and fractures, while aliased noise can focus into false coherent events which affect interpretation and contaminate amplitude variation with offset, amplitude variation with azimuth and elastic inversion. Preconditioned least-squares migration minimizes these artifacts. We implement least-squares migration by minimizing the difference between the original data and the modeled demigrated data using an iterative conjugate gradient scheme. Unpreconditioned least-squares migration better estimates the subsurface amplitude, but does not suppress aliasing. In this work, we precondition the results by applying a 3D prestack structure-oriented LUM (lower-upper-middle) filter to each common offset and common azimuth gather at each iteration. The preconditioning algorithm not only suppresses aliasing of both signal and noise, but also improves the convergence rate. We apply the new preconditioned least-squares migration to the Marmousi model and demonstrate how it can improve the seismic image compared with conventional migration, and then apply it to one survey acquired over a new resource play in the Mid-Continent, USA. The acquisition footprint from the targets is attenuated and the signal to noise ratio is enhanced. To demonstrate the impact on interpretation, we generate a suite of seismic attributes to image the Mississippian limestone, and show that the karst-enhanced fractures in the Mississippian limestone can be better illuminated.

  11. Influence of Water Content on the Mechanical Behaviour of Limestone: Role of the Clay Minerals Content

    NASA Astrophysics Data System (ADS)

    Cherblanc, F.; Berthonneau, J.; Bromblet, P.; Huon, V.

    2016-06-01

    The mechanical characteristics of various sedimentary stones significantly depend on the water content, where 70 % loss of their mechanical strengths can be observed when saturated by water. Furthermore, the clay fraction has been shown to be a key factor of their hydro-mechanical behaviour since it governs for instance the hydric dilation. This work aims at investigating the correlations between the clay mineral content and the mechanical weakening experienced by limestones when interacting with water. The experimental characterization focuses on five different limestones that exhibit very different micro-structures. For each of them, we present the determination of clay mineral composition, the sorption isotherm curve and the dependences of tensile and compressive strengths on the water content. It emerges from these results that, first, the sorption behaviour is mainly governed by the amount of smectite layers which exhibit the larger specific area and, second, the rate of mechanical strength loss depends linearly on the sorption capacity. Indeed, the clay fraction plays the role of a retardation factor that delays the appearance of capillary bridges as well as the mechanical weakening of stones. However, no correlation was evidenced between the clay content and the amplitude of weakening. Since the mechanisms whereby the strength decreases with water content are not clearly established, these results would help to discriminate between various hypothesis proposed in the literature.

  12. Rockslides on limestone cliffs with sub-horizontal bedding in the southwestern calcareous area, China

    NASA Astrophysics Data System (ADS)

    Feng, Z.; Li, B.; Yin, Y. P.; He, K.

    2014-06-01

    Calcareous mountainous areas are highly prone to geohazards, and rockslides play an important role in cliff retreat. This study presents three examples of failures of limestone cliffs with sub-horizontal bedding in the southwestern calcareous area of China. Field observations and numerical modeling of Yudong Escarpment, Zengzi Cliff, and Wangxia Cliff showed that pre-existing vertical joints passing through thick limestone and the alternation of competent and incompetent layers are the most significant features for rockslides. A "hard on soft" cliff made of hard rocks superimposed of soft rocks is prone to rock slump, characterized by shearing through the underlying weak strata along a curved surface and backward tilting. When a slope contains weak interlayers rather than a soft basal layers, a rock collapse could occur from the compression fracture and tensile split of the rock mass near the interfaces. A rock slide might shear through a hard rock mass if no discontinuities are exposed in the cliff slope, and sliding may occur along a moderately inclined rupture plane. The "toe breakout" mechanism mainly depends on the strength characteristics of the rock mass.

  13. Rockslides on limestone cliffs with subhorizontal bedding in the southwestern calcareous area of China

    NASA Astrophysics Data System (ADS)

    Feng, Z.; Li, B.; Yin, Y. P.; He, K.

    2014-09-01

    Calcareous mountainous areas are highly prone to geohazards, and rockslides play an important role in cliff retreat. This study presents three examples of failures of limestone cliffs with subhorizontal bedding in the southwestern calcareous area of China. Field observations and numerical modeling of Yudong Escarpment, Zengzi Cliff, and Wangxia Cliff showed that pre-existing vertical joints passing through thick limestone and the alternation of competent and incompetent layers are the most significant features for rockslides. A "hard-on-soft" cliff made of hard rocks superimposed on soft rocks is prone to rock slump, characterized by shearing through the underlying weak strata along a curved surface and backward tilting. When a slope contains weak interlayers rather than a soft basal, a rock collapse could occur from the compression fracture and tensile split of the rock mass near the interfaces. A rockslide might shear through a hard rock mass if no discontinuities are exposed in the cliff slope, and sliding may occur along a moderately inclined rupture plane. The "toe breakout" mechanism mainly depends on the strength characteristics of the rock mass.

  14. Moss cushions facilitate water and nutrient supply for plant species on bare limestone pavements.

    PubMed

    Sand-Jensen, Kaj; Hammer, Kathrine Jul

    2012-10-01

    Dense moss cushions of different size are distributed across the bare limestone pavements on Øland, SE Sweden. Increasing cushion size is predicted to physically protect and improve performance and colonization by vascular plants. Therefore, we tested water balance, phosphorus supply, and species richness, and evaluated duration of plant activity during desiccation as a function of ground area, for a large collection of moss cushions. We found that lower evaporation and higher water storage contributed equally to extending the desiccation period with increasing cushion size. Evaporation rates declined by the -0.36 power of cushion diameter, and were not significantly different from -0.50 for the square root function previously predicted for the increasing thickness of the boundary layer, with greater linear dimensions for smooth flat objects at low wind velocities. Size dependence vanished under stagnant conditions. One moss species was added to the species pool for every nine-fold increase in cushion area. Vascular plants were absent from the smallest cushions, whereas one or two species, on average, appeared in 375- and 8,500-cm(2) cushions with water available for 6 and 10 days during desiccation. Phosphorus concentrations increased stepwise and four-fold from detritus to surface mosses and to vascular plants, and all three pools increased with cushion size. We conclude that cushion mosses and cushion size play a critical role in this resource-limited limestone environment by offering an oasis of improved water and nutrient supply to colonization and growth of plants.

  15. Characterization of limestone reacted with acid-mine drainage in a pulsed limestone bed treatment system at the Friendship Hill National Historical Site, Pennsylvania, USA

    USGS Publications Warehouse

    Hammarstrom, J.M.; Sibrell, P.L.; Belkin, H.E.

    2003-01-01

    Armoring of limestone is a common cause of failure in limestone-based acid-mine drainage (AMD) treatment systems. Limestone is the least expensive material available for acid neutralization, but is not typically recommended for highly acidic, Fe-rich waters due to armoring with Fe(III) oxyhydroxide coatings. A new AMD treatment technology that uses CO2 in a pulsed limestone bed reactor minimizes armor formation and enhances limestone reaction with AMD. Limestone was characterized before and after treatment with constant flow and with the new pulsed limestone bed process using AMD from an inactive coal mine in Pennsylvania (pH = 2.9, Fe = 150 mg/l, acidity = 1000 mg/l CaCO3). In constant flow experiments, limestone is completely armored with reddish-colored ochre within 48 h of contact in a fluidized bed reactor. Effluent pH initially increased from the inflow pH of 2.9 to over 7, but then decreased to 6 during operation. Limestone removed from a pulsed bed pilot plant is a mixture of unarmored, rounded and etched limestone grains and partially armored limestone and refractory mineral grains (dolomite, pyrite). The ???30% of the residual grains in the pulsed flow reactor that are armored have thicker (50- to 100-??m), more aluminous coatings and lack the gypsum rind that develops in the constant flow experiment. Aluminium-rich zones developed in the interior parts of armor rims in both the constant flow and pulsed limestone bed experiments in response to pH changes at the solid/solution interface. ?? 2003 Elsevier Ltd. All rights reserved.

  16. Durability assessment of limestone subjected to surface treatments

    NASA Astrophysics Data System (ADS)

    Theodoridou, Magdalini; Charalambous, Cleopatra; Ioannou, Ioannis

    2017-04-01

    Weathering is inevitable in existing limestone structures due to their exposure to fluctuating and aggressive environmental conditions, such as wetting/drying, and the presence of salts. Therefore, conservation treatments are often deemed necessary in order to prevent or at least delay the progress of deterioration and to strengthen weathered stones. This paper focuses on the effect of an ethanol-based laboratory produced water repellent and three water-based commercial products (water repellent, pure acrylic emulsion mixed with a water repellent with thermal insulation properties and consolidant) on the durability and other properties of three different types of limestone (massive chalk, calcarenite and bioclastic limestone). All test specimens were subjected to micro-destructive cutting tests before/after the application of the aforementioned surface treatments to investigate changes in resistance to cutting on the area close to the treated surface. They were also subjected to two cycles of salt contamination with 20% w/w Na2SO4•10H2O solution by capillary absorption through their bottom face, until 2 mm of pore space was theoretically filled with salt crystals. Drying after salt contamination took place at 70 °C. The results of the micro-destructive cutting tests showed increases in cutting resistance at the topmost area (1-2 mm below the treated surface) of the massive chalk and the calcarenite, but no significant changes in the case of the rather non-homogeneous bioclastic limestone. At the same time, the performance of each surface treatment varied from lithotype to lithotype. The laboratory produced water repellent showed a generally better performance; no signs of damage were detected due to the formation of salt crystals within the pores of the materials, i.e. subflorescence, when applied on the calcarenite and the bioclastic limestone. Very poor performance was observed for all treatments when applied on the massive chalk. This accounted for (i

  17. Origin and Age of the Yemi Limestone Breccia, Korea

    NASA Astrophysics Data System (ADS)

    KOH, Hee Jae

    2015-04-01

    The Yemi Limestone Breccia (YLB), which has been argued for its age and depositional origin, occurs sporadically in the upper part of the Cambro-Ordovician Chosun Supergroup (CS) in Korean Peninsula. The YLB is characterized by a carbonate breccia with calcareous and carbonaceous shale matrix. Based on occurrence and composition of breccia and matrix, the YLB can be classified into Type-I and Type-II carbonate breccia. Type-I carbonate breccia comprises dark gray to light gray limestone and lime-mudstone breccia with calcareous matrix and is commonly constrained within the upper part of the CS as a lens-shaped zonal occurrence. The Type-I carbonate breccia results in syn-depositional solution-collapsed brecciation through karstification during intermittent subareal exposure of platform carbonate in Middle Ordovician. Type-II carbonate breccia mainly occurs in the uppermost part of the CS showing an irregular-shaped distribution rather than sheet-like layering parallel to bedding. Type-II carbonate breccia consists of gray to dark gray limestone and lime-mudstone breccia and shale matrix. Matrix is typically purple to reddish and gray to dark gray shale with minor amount of sandstone, and partly carbonaceous indicating organic origin. Most of Type-II carbonate breccia is morphologically classified into chaotic breccia. Matrix and breccia display considerable difference of composition and deformational structures. Breccia preserves various penetrative ductile to brittle deformation structures such as cleavage superimposing bedding, minor fold structure, minor faults crosscutting both dolomite and calcite veins, and fracture zones filled in calcite. However, these deformational structures of breccia do not continuously extended into matrix. Especially Type-II carbonate breccia is well observed in limestone of the lower part of unconformity between CS and clastic rocks of the Jurassic Bansong Group (BS). Fractured and solution zones of brecciated limestone of the CS

  18. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  19. Thermo-Hydro-Mechanical-Chemical Coupled Modeling of Geothermal Doublet Systems in Limestones -revised

    NASA Astrophysics Data System (ADS)

    Rühaak, Wolfram; Heldmann, Claus-Dieter; Pei, Liang; Bartels, Jörn; Weinert, Sebastian; Sass, Ingo

    2016-04-01

    Limestone aquifers in Southern Germany have been used within the last decade very successfully for geothermal heating and - to a lesser extent - for power generation. As an example the region around Munich has been extensively explored. While the extent of usage of this reservoir is increasing there is also an increased interest in better understanding of the reservoir properties and its change in the course of operation. For instance, the observed production and injection pressures are partly hard to explain. They may be related to mechanical or chemical processes, or both. Based on extensive data of outcrop studies and drillings, a data-base for the relevant physical properties of the respective limestones has been complied. The data include thermal conductivity, density, specific heat capacity, permeability, as well as mechanical properties like thermal expansion coefficient and elasticity modules. By using the hydro-thermo-chemical simulator FEFLOW together with an extension for thermo- and hydro-mechanical coupling the relevant processes are studied and compared with observed data. At the EGU Meeting in 2015 results of an initial study have been presented. This time results based on a completely new model setup and also using newly developed code will be presented. As a conclusion main challenges while modeling THMC fracture flow by using a multi-continua approach will be discussed.

  20. Preservation of York Minster historic limestone by hydrophobic surface coatings

    PubMed Central

    Walker, Rachel A.; Wilson, Karen; Lee, Adam F.; Woodford, Julia; Grassian, Vicki H.; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-01-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from ‘breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO2/H2O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation. PMID:23198088

  1. Cement substitution by a combination of metakaolin and limestone

    SciTech Connect

    Antoni, M.; Rossen, J.; Martirena, F.; Scrivener, K.

    2012-12-15

    This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury intrusion porosimetry and isothermal calorimetry. We show that 45% of substitution by 30% of metakaolin and 15% of limestone gives better mechanical properties at 7 and 28 days than the 100% PC reference. Our results show that calcium carbonate reacts with alumina from the metakaolin, forming supplementary AFm phases and stabilizing ettringite. Using simple mass balance calculations derived from thermogravimetry results, we also present the thermodynamic simulation for the system, which agrees fairly well with the experimental observations. It is shown that gypsum addition should be carefully balanced when using calcined clays because it considerably influences the early age strength by controlling the very rapid reaction of aluminates.

  2. Background radiation measurements at 2200 ft depth in limestone mine.

    NASA Astrophysics Data System (ADS)

    Olling Back, Henning; Vogelaar, R. Bruce; Johnson, D. Nathan

    2003-10-01

    An active limestone mine in southwestern Virginia is being investigated as a possible site for detectors requiring a low muon flux. The current depth of the mine is 2200 feet. However, the mining operations continue to follow a vain of pure limestone at a 30-degree downward plane under a rising escarpment, and so greater depths can be achieved relatively quickly. With over 50 miles of drifts, many 100 ft high and 40 ft wide, and drive in access, this is a potential venue for future low background detectors. We will be reporting initial measurements of the muon flux as a function of zenith angle, as well as the ambient gamma radiation from the surrounding rock.

  3. Preservation of York Minster historic limestone by hydrophobic surface coatings

    NASA Astrophysics Data System (ADS)

    Walker, Rachel A.; Wilson, Karen; Lee, Adam F.; Woodford, Julia; Grassian, Vicki H.; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-11-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from `breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO2/H2O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation.

  4. EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.

    USGS Publications Warehouse

    Mossotti, Victor G.; Lindsay, James R.; Hochella, Michael F.

    1987-01-01

    Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were not washed by precipitation. The gas-solid reaction of SO//2 with calcite was selected for detailed consideration. It appears from the model that under arid conditions, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO//2 concentration once the surface has been saturated with gypsum. Under wet conditions, surface sulfation and weight loss are probably dominated by mechanisms involving wet stone. However, if the rain events are frequent and delimited by periods of dryness, the quantity of gypsum produced by a gas-solid reaction mechanism should correlate with both the frequency of rain events and the atmospheric SO//2 level.

  5. Dolomitization of Quaternary reef limestones, Aitutaki, Cook Islands

    USGS Publications Warehouse

    Hein, J.R.; Gray, S.C.; Richmond, B.M.; White, L.D.

    1992-01-01

    The primary reef framework is considered to have been deposited during several highstands of sea level. Following partial to local recrystallization of the limestone, a signle episode of dolomitization occurred. Both tidal and thermal pumping drove large quantities of seawater through the porous rocks and perhaps maintained a wide mixing zone. However, the isotopic, geochemical and petrographic data do not clearly indicate the extent of seawater mixing. -from Authors

  6. Time-Dependent Rock Failure in a Heterogeneous Limestone

    NASA Astrophysics Data System (ADS)

    Roth, K.; Kemeny, J.

    2015-12-01

    Time-dependent rock failure is an important aspect in the analysis of long-term rock stability for slopes, dam and bridge foundations, and underground storage facilities. An on-going project at the University of Arizona is using Kartchner Caverns in Benson, Arizona as a natural analog to study such failure by reconstructing the process of natural cave breakdown with subcritical crack growth modeling. Breakdown is thought to occur along joints through the time-dependent failure of rock bridges: sections of intact rock separating discontinuities in a rock mass. The Escabrosa limestone composing the caverns ranges from a more homogenous, even-grained texture to a more heterogeneous texture consisting of coarse-grained veins and solution cavities set in a fine-grained matrix. To determine if the veined regions are more susceptible to fracturing and act as the nuclei of rock bridge failure, fracture toughness tests were conducted for both textures. The subcritical crack growth parameters were calculated using the constant stress-rate method. Results indicate that the more heterogeneous limestone has a higher fracture strength, fracture toughness, and subcritical crack growth index n than the more homogeneous limestone. This is in agreement with previous studies which found that a more complex and heterogeneous microstructure produces a larger microcrack process zone, leading to higher fracture energies and lower susceptibility to subcritical crack growth. Thus, despite their solution cavities, the calcite veins do not localize failure or act as planes of weakness; instead, rock bridges fail through the more homogeneous limestone matrix.

  7. Full-scale results for TAM limestone injection

    SciTech Connect

    Baer, S.

    1996-12-31

    Information is outlined on the use of thermally active marble (TAM) sorbents in boilers. Data are presented on: the comparison of TAM to limestone; NOVACON process development history; CFB test history; CFB pilot scale test; full-scale CFB trial; August, 1996 CFB demonstration; Foster Wheeler Mount Carmel sorbent feed rate comparison and Ca:S comparison; unburned carbon is ash; and advantages and savings in CFB boilers.

  8. Modified dry limestone process for control of sulfur dioxide emissions

    DOEpatents

    Shale, Correll C.; Cross, William G.

    1976-08-24

    A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

  9. Recovery and recycling of limestone in LEC flue gas desulfurization. Final report, third year

    SciTech Connect

    Gardner, N.C.; Boo, J.Y.

    1993-12-20

    A potentially attractive flue gas desulfurization method called Limestone Emission Control (LEC) is currently being investigated by Prudich at Ohio University. In this process, beds of 1/8 inch limestone gravel particles absorb sulfur dioxide from flue gas. This forms sulfite and sulfate salts which coat limestone, blinding the surface and limiting utilization to 20%. Favorable economics can be generating when the unreacted portion of the limestone is recovered by mechanical grinding. This project is a wet method for grinding and recovering the spent limestone from the LEC process, utilizing an impeller fluidizer, a new type of slurry processor. It consists of a cylindrical vessel with an impeller at one end. The impeller generates sufficient pressure head to serve as a slurry pump. It combines the operation of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry. The objectives of the first two years were to operate fluidizer in a batch mode to carry grinding experiments, and to determine the removal of the sulfur coatings from the limestone when operating the fluidizer in a continuous mode. The main thrusts of the third year were to complete the grinding data and coordinate the data with reactivity determinations of the recovered limestone. Direct measurement of power requirements, operation of single impeller fluidizer, grinding of surface deposits and other methods of removing surface deposits have also been investigated along with sorption characteristics of recovered limestone, microscopic examination of the limestone surface, and limestone attrition.

  10. GPR study of bedding planes, fractures, and cavities in limestone

    NASA Astrophysics Data System (ADS)

    Pipan, M.; Baradello, L.; Forte, E.; Prizzon, A.

    2000-04-01

    We performed a multi-fold GPR study at a Cretaceous-Tertiary (K-T) outcrop in limestone layers of the Peri-Adriatic carbonatic platform, Italy). Primary objective of the study was imaging of the K-T contact and mapping of localized depth variations in a general framework of homoclinical limestone layers. A secondary objective was the study of faults, fractures and cavities of interest for engineering purposes. A combination of 2-D and 3-D multifold techniques was used to image and map structural and stratigraphic features. A 200 sqm grid was surveyed with 1 meter cross-line spacing and 5 cm in- line trace interval. The K-T contact is electromagnetically transparent, and it is actually deduced from paleontologic evidence. Due to the homoclinal trend, K-T topography is reconstructed from the bedding planes bounding the contact. Fractures antithetic to bedding planes are imaged by 2-D stack and migrated profiles. Part of the fractures can be considered small transtensional faults. The results obtained provide the first geophysical evidence of small-scale transtensive deformation in the area. Curvilinear radar reflector, intersecting the homoclinal bedding planes, are imaged in faulted zones and are possibly related to limestone buildups. A fractured rock volume develops into a cavity with average estimated section of a 4 sqm.

  11. Stratigraphy of the Upper Pleistocene Miami Limestone of Florida

    SciTech Connect

    Johnson, R.A.

    1993-03-01

    The upper Pleistocene Miami Limestone is probably the most stratigraphically-complex formation in the Cenozoic of Florida. The Miami overlies and vertically/laterally grades into the upper Pleistocene Ft. Thompson Formation to the west in southeast Palm Beach County (west of I-95); to the west in Broward County (west of the Turnpike); and to the north in south Broward County (along U.S. 27). The Miami overlies and very locally vertically grades into the Ft. Thompson in all of Dade County. The Miami overlies and vertically/laterally grades into the upper Pleistocene Anastasia Formation to the north and east in southeast Palm Beach County (east of I-95), and to the northeast in east Broward County (east of the Turnpike). The Miami laterally grades into the upper Pleistocene Key Largo Limestone to the southeast in extreme southeast Dade County, and overlies and locally vertically grades into the Key Largo in the Lower Keys, south Monroe County. The Miami unconformably overlies the Pliocene Tamiami Formation and pinches out to the west in northeast mainland Monroe and southeast Collier Counties, and also pinches out to the north in east-central Palm Beach County. In all areas, the Miami Limestone is either overlain unconformably by very discontinuous undifferentiated surficial sediments or forms land surface.

  12. Modeling of SO{sub 2} absorption into limestone suspensions

    SciTech Connect

    Lancia, A.; Musmarra, D.; Pepe, F.

    1997-01-01

    The wet limestone flue gas desulfurization process, and more specifically absorption of SO{sub 2} limestone suspensions, was studied. Experiments of SO{sub 2} absorption were carried out using a bubbling reactor with a mixture of sulfur dioxide and nitrogen in the gas phase and an aqueous limestone suspension in the liquid phase. The SO{sub 2} absorption rate was measured at different compositions of both gas and liquid phases and at different gas flow rates and agitator speeds. A model based on the film theory was proposed to describe liquid-side mass transfer. It was assumed that the liquid-phase diffusional resistance is concentrated in a layer, the thickness of which depends on fluid dynamics, but is independent of the nature of the reactions taking place. The equations considered by the model describe conditions of thermodynamic equilibrium as well as material and electrical balances and use the experimentally determined gas- and liquid-side mass-transfer coefficients, rather than empirical parameters. Model calculations and experimental results were compared, and a good consistency was found. Eventually the model was used to evaluate the absorption enhancement factor as a function of gas- and liquid-phase composition.

  13. Development of gypsum alteration on marble and limestone

    USGS Publications Warehouse

    McGee, E.S.

    1996-01-01

    Blackened alteration crusts of gypsum plus particulates that form on sheltered areas on marble and limestone buildings pose a challenge for rehabilitation and cleaning. Fresh marble and limestone samples exposed at monitored exposure sites present conditions of simple geometry and well-documented exposures but have short exposure histories (one to five years). The gypsum alteration crusts that develop on these samples provide insight into the early stages and rate of alteration crust formation. Alteration crusts from buildings give a longer, but less well known exposure history and present much more complex surfaces for gypsum accumulation. Integrated observations and measurements of alteration crusts from exposure samples and from buildings identify four factors that are important in the formation and development of alteration crusts on marble and limestone: (1) pollution levels, (2) exposure to rain or washing, (3) geometry of exposure of the stone surface, and (4) permeability of the stone. The combination of these factors contributes to both the distribution and the physical characteristics of the gypsum crusts which may affect cleaning decisions.

  14. Thermo-poroelastic response of an argillaceous limestone

    NASA Astrophysics Data System (ADS)

    Selvadurai, Patrick; Najari, Meysam

    2016-04-01

    Argillaceous limestones are now being considered by many countries that intend to develop deep geologic storage facilities for siting both high-level and intermediate- to low-level nuclear fuel wastes. In deep geologic settings for high level nuclear wastes, the heating due to radioactive decay is transmitted through an engineered barrier, which consists of the waste container and an engineered geologic barrier, which consists of an encapsulating compacted bentonite. The heat transfer process therefore leads to heating of the rock mass where the temperature of the rock is substantially lower than the surface temperature of the waste container. This permits the use of mathematical theories of poroelastic media where phase transformations, involving conversion of water to a vapour form are absent. While the thermo-poroelastic responses of geologic media such as granite and porous tuff have been investigated in the literature, the investigation of thermo-poroelastic responses of argillaceous limestones is relatively new. Argillaceous limestones are considered to be suitable candidates for siting deep geologic repositories owing to the ability to accommodate stress states with generation of severe defects that can influence their transmissivity characteristics. Also the clay fraction in such rocks can contribute to long term healing type phenomena, which is a considerable advantage. This research presents the results of a laboratory investigation and computational modelling of the same that examines the applicability of the theory of thermo-poroelasticity, which extend Biot's classical theory of poroelasticity to include uncoupled heat conduction. The experimental configuration involves the boundary heating of a cylinder of the Cobourg Limestone from southern Ontario, Canada. The cylinder measuring 150 mm in diameter and 278 mm in length contains an axisymmetric fluid-filled cylindrical cavity measuring 26 mm in diameter and 139 mm in length. Thermo-poroelastic effects

  15. Calcium looping spent sorbent as a limestone replacement in the manufacture of portland and calcium sulfoaluminate cements.

    PubMed

    Telesca, Antonio; Marroccoli, Milena; Tomasulo, Michele; Valenti, Gian Lorenzo; Dieter, Heiko; Montagnaro, Fabio

    2015-06-02

    The calcium looping (CaL) spent sorbent (i) can be a suitable limestone replacement in the production of both ordinary Portland cement (OPC) and calcium sulfoaluminate (CSA) cement, and (ii) promotes environmental benefits in terms of reduced CO2 emission, increased energy saving and larger utilization of industrial byproducts. A sample of CaL spent sorbent, purged from a 200 kWth pilot facility, was tested as a raw material for the synthesis of two series of OPC and CSA clinkers, obtained from mixes heated in a laboratory electric oven within temperature ranges 1350°-1500 °C and 1200°-1350 °C, respectively. As OPC clinker-generating mixtures, six clay-containing binary blends were investigated, three with limestone (reference mixes) and three with the CaL spent sorbent. All of them showed similar burnability indexes. Moreover, three CSA clinker-generating blends (termed RM, MA and MB) were explored. They included, in the order: (I) limestone, bauxite and gypsum (reference mix); (II) CaL spent sorbent, bauxite and gypsum; (III) CaL spent sorbent plus anodization mud and a mixture of fluidized bed combustion (FBC) fly and bottom ashes. The maximum conversion toward 4CaO·3Al2O3·SO3, the chief CSA clinker component, was the largest for MB and almost the same for RM and MA.

  16. Overview of Trenton exploration and development in New York state

    SciTech Connect

    Drazan, D.J.

    1987-09-01

    Exploration and development of the Middle Ordovician Trenton Limestone has occurred in New York state since the late 1800s. From the early days of exploration to the present, the Trenton has proven to be an elusive target for developers. However, renewed interest and current activity, coupled with improved drilling and completion techniques, may yet prove the Trenton Limestone in New York to be an important reservoir.

  17. Selected Data for Wells and Test Holes Used in Structure-Contour Maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation in the Black Hills Area, South Dakota

    DTIC Science & Technology

    1999-01-01

    Selected Data for Wells and Test Holes Used in Structure-Contour Maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison...Test Holes Used in Structure-Contour Maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation...Structure-Contour Maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation in the Black Hills Area

  18. Inelastic compaction of a quartz-rich limestone (Invited)

    NASA Astrophysics Data System (ADS)

    Baud, P.; Schubnel, A.; rolland, A.; Heap, M. J.

    2013-12-01

    The analysis of deformation and failure in many sedimentary settings hinges upon a fundamental understanding of inelastic behavior and failure mode of porous carbonate rocks. Previous studies on porous carbonate focused primarily on relatively pure limestone (composed in majority of calcite). Inelastic compaction in these carbonates was reported to be associated to cataclastic pore collapse and in most cases homogeneous cataclastic flow. Recent experimental results however revealed the development of compaction localization in the more porous end-members. The analysis of strain localization and complex failure modes in limestone has proved to be significantly more challenging than in sandstone because acoustic emissions (AE) cannot usually be used to guide systematic microstructural analysis. Recent studies have therefore relied on X-ray Computed Tomography, a technique that can to date only be used in situ in relatively limited systems. In this study we investigated the development of inelastic damage in a quartz-rich limestone with two main objectives: (1) quantify the impact of a secondary mineral such as quartz on the strength and strain localization in porous carbonate, (2) try to follow the development of inelastic damage using AE in such a quartz-rich rock. Saint-Maximin limestone of 37% porosity and composed of 80% calcite and 20% quartz was selected for this study. Two series of conventional triaxial experiments were performed in parallel at room temperature, constant strain rate in both nominally dry and wet conditions at confining pressures between 3 and 50 MPa. Wet experiments were carried out with water in drained conditions at 10 MPa of pore pressure. The first series of experiments were performed at IPG Strasbourg on relatively small samples. The failure modes and spatial distribution of damage were studied systematically in these samples. The second series of experiments were performed on larger samples at ENS Paris. Acoustic emission activity was

  19. Effect of an acid rain environment on limestone surfaces

    SciTech Connect

    Mossotti, V.G.; Lindsay, J.R.; Hochella, M.F. Jr.

    1987-11-01

    As part of a study to assess mineralogical alterations in building stone caused by acid rain, Salem limestone samples were exposed for one year in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone (control material). All samples collected from urban exposure sites developed gypsum stains on the grounding surfaces, where the stones were unwashed by precipitation. However, the bulk chemistry of the urban samples (not including the stain) was virtually identical to that of the control stone. Sulfur (in the form of sulfate) was disseminated over the calcite grain surfaces to a depth less than 10 nanometer in the freshly quarried limestone; an identical sulfate layer was found on the calcite grains after the 1-y exposure period. Mass balance calculations and sulfur isotope patterns indicate that the gypsum stain on the protected surfaces consists of adventitious sulfur. A model, involving the attack of SO/sub 2/ on dry calcite, was used to define the conditions for stain formation on dry, protected surfaces. This suggests that under arid conditions, once the surface has been saturated with gypsum, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO/sub 2/ concentration. On rain-washed surfaces experiencing gas-solid attack during intermittent dry periods, the quantity of gypsum produced by a gas-solid reaction mechanism should strongly correlate with both the frequency of rain events and the atmospheric SO/sub 2/ level, provided that the rain events are frequent and clearly delimited by periods of dryness.

  20. Cognitive Correlates of Playful Behavior.

    ERIC Educational Resources Information Center

    Barnett, Lynn A.

    1979-01-01

    The free play behavior of young children allows the opportunity to actively explore, investigate, and manipulate features of the adult world, and to assimilate the characteristics of novel aspects of the environment. (Author)

  1. Shock Propagation in Crustal Rocks: Sandstone, Limestone and Shale.

    DTIC Science & Technology

    1995-04-01

    and shale display three separate phases on the Hugoniot curve. For sandstone these are quartz, stishovite , and a dense liquid. The limestone Hugoniot...of pressure phase can be modeled by f = Ae(-Ea/RT). For stishovite from quartz, A = 7.286 and Ea (kJ/mol) = 89.36-71.97 (Po/Poo), where Po and Poo... stishovite . Carbonate-rich (approx. 33% CaCO3 by weight) shale has a bulk modulus of Kso = 30.9 GPa. This appears to be the result of the clay/mica

  2. Elucidation of denitrification mechanism in karstic Ryukyu limestone aquifer

    NASA Astrophysics Data System (ADS)

    Hijikawa, K.

    2014-12-01

    Nitrate (NO3-) concentrations in public water supplies have risen above acceptable levels in many areas of the world including Japan, largely as a result of contamination by human and animal waste and overuse of fertilizers. A previous study has characterized nitrate concentrations in groundwater in this area is a higher than the upper value (44mgL-1) of environmental quality criteria on one hands. On the other hand, there exists points where the concentration of nitric acid is not detected, which suggests the possibility of denitrification. During early 2000, a new analytical procedure for nitrate isotopic measurement, termed the "denitrifier method", was established. With the development of the nitrate isotope tracer method, much research has been reported detailing sources of groundwater nitrate and denitrification mechanisms. This study presents a pilot case study (in the southern part of Okinawa Main Island, Japan, where Ryukyu limestone is extensively distributed) using the combined stable isotope ratios of major elements (C, N and S) as net recorders of the biogeochemical reactions with the aim of elucidation of denitrification mechanism in Ryukyu limestone aquifer. As a result, significant decreases in nitrate concentrations due to denitrification were observed in groundwater at some locations, which induced increases in isotope ratios up to 59.7‰ for δ15NNO3. These points of groundwater were located above the cutoff wall of the underground dam and near the fault. It is considered that the residence time of the groundwater is longer than the other points at these denitrification points, and that reduction condition tends to be formed in the groundwater. However, the rapid rise of the groundwater level due to rainfall is likely to occur in the Ryukyu limestone aquifer, where the ground water was found to have changed dynamically from the reduction condition to the oxidation condition which a denitrification (has not occured)does not occur. Moreover, the

  3. Water transport in limestone by X-ray CAT scanning

    USGS Publications Warehouse

    Mossoti, Victor G.; Castanier, Louis M.

    1989-01-01

    The transport of water through the interior of Salem limestone test briquettes can be dynamically monitored by computer aided tomography (commonly called CAT scanning in medical diagnostics). Most significantly, unless evaporation from a particular face of the briquette is accelerated by forced air flow (wind simulation), the distribution of water in the interior of the briquette remains more or less uniform throughout the complete drying cycle. Moreover, simulated solar illumination of the test briquette does not result in the production of significant water gradients in the briquette under steady-state drying conditions.

  4. Penetration into limestone targets with ogive-nose steel projectiles

    SciTech Connect

    Frew, D.J.; Green, M.L.; Forrestal, M.J.; Hanchak, S.J.

    1996-12-01

    We conducted depth of penetration experiments into limestone targets with 3.0 caliber-radius-head, 4340 Rc 45 steel projectiles. Powder guns launched two projectiles with length-to-diameter ratios of ten to striking velocities between 0.4 and 1.5 km/s. Projectiles had diameters and masses of 12.7 mm, 0. 117 kg and 25.4 mm, 0.610 kg. Based on data sets with these two projectile scales, we proposed an empirical penetration equation that described the target by its density and an empirical strength constant determined from penetration depth versus striking velocity data.

  5. Reassessment of the Georgetown limestone as a hydrogeologic unit of the Edwards Aquifer, Georgetown area, Texas

    USGS Publications Warehouse

    Land, L.F.; Dorsey, M.E.

    1988-01-01

    An analysis of the water-quality characteristics suggests that the Edwards Limestone and the streams have a significant hydraulic connection but the ground-water circulation between the Edwards Limestone and the Georgetown Limestone is very limited. The only area where a high degree of hydraulic connection between the main water-bearing zone of the Edwards aquifer (Edwards Limestone) and the streams was found is near the updip limits of the Georgetown Limestone, where a nearby major fault occurs and where major springs have developed. These findings suggest that the Georgetown Limestone does not function as a unit of the Edwards aquifer but as a regional confining bed with localized avenues that allow flow to and from the underlying Edwards aquifer.

  6. Simultaneous removal of heavy metals from aqueous solution by natural limestones

    NASA Astrophysics Data System (ADS)

    Sdiri, Ali; Higashi, Teruo

    2013-03-01

    Two natural limestone samples, collected from the Campanian-Maastrichtian limestones, Tunisia, were used as adsorbents for the removal of toxic metals in aqueous systems. The results indicated that high removal efficiency could be achieved by the present natural limestones. Among the metal ions studied, Pb2+ was the most preferably removed cation because of its high affinity to calcite surface. In binary system, the presence of Cu2+ effectively depressed the sorption of Cd2+ and Zn2+. Similarly Cu2+ strongly competed with Pb2+ to limestone surface. In ternary system, the removal further decreased, but considerable amount of Pb2+ and Cu2+ still occurred regardless of the limestone sample. The same behavior was observed in quadruple system, where the selectivity sequence was Pb2+ > Cu2+ > Cd2+ > Zn2+. From these results, it was concluded that the studied limestones have the required technical specifications to be used for the removal of toxic metals from wastewaters.

  7. Sand and Water Table Play

    ERIC Educational Resources Information Center

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  8. Outdoor Play: Combating Sedentary Lifestyles

    ERIC Educational Resources Information Center

    Thigpen, Betsy

    2007-01-01

    Increasingly sedentary lifestyles are contributing to overweight and other health concerns as children spend less and less time outside engaged in active play. Outdoor play provides important opportunities to explore the natural world, interact with peers, engage in vigorous physical activity, and learn about our environment. However, outdoor…

  9. Sand and Water Table Play

    ERIC Educational Resources Information Center

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  10. Engaging Families through Artful Play

    ERIC Educational Resources Information Center

    Brown, Robert

    2015-01-01

    This paper explores how aligned arts and play experiences can extend child and family engagement in a public outdoor space. The importance of outdoor play for children is strongly advocated and in response local governments provide playgrounds and recreational open spaces. To extend further the experiences afforded in such spaces some local…

  11. Characterization of the spatial distribution of porosity in the eogenetic karst Miami Limestone using ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Mount, G. J.; Comas, X.; Wright, W. J.; McClellan, M. D.

    2014-12-01

    Hydrogeologic characterization of karst limestone aquifers is difficult due to the variability in the spatial distribution of porosity and dissolution features. Typical methods for aquifer investigation, such as drilling and pump testing, are limited by the scale or spatial extent of the measurement. Hydrogeophysical techniques such as ground penetrating radar (GPR) can provide indirect measurements of aquifer properties and be expanded spatially beyond typical point measures. This investigation used a multiscale approach to identify and quantify porosity distribution in the Miami Limestone, the lithostratigraphic unit that composes the uppermost portions of the Biscayne Aquifer in Miami Dade County, Florida. At the meter scale, laboratory measures of porosity and dielectric permittivity were made on blocks of Miami Limestone using zero offset GPR, laboratory and digital image techniques. Results show good correspondence between GPR and analytical porosity estimates and show variability between 22 and 66 %. GPR measurements at the field scale 10-1000 m investigated the bulk porosity of the limestone based on the assumption that a directly measured water table would remain at a consistent depth in the GPR reflection record. Porosity variability determined from the changes in the depth to water table resulted in porosity values that ranged from 33 to 61 %, with the greatest porosity variability being attributed to the presence of dissolution features. At the larger field scales, 100 - 1000 m, fitting of hyperbolic diffractions in GPR common offsets determined the vertical and horizontal variability of porosity in the saturated subsurface. Results indicate that porosity can vary between 23 and 41 %, and delineate potential areas of enhanced recharge or groundwater / surface water interactions. This study shows porosity variability in the Miami Limestone can range from 22 to 66 % within 1.5 m distances, with areas of high macroporosity or karst dissolution features

  12. Analysis of medieval limestone sculpture from southwestern France and the Paris Basin by NAA

    SciTech Connect

    Holmes, L.; Harbottle, G.

    1994-12-31

    Compositional characterization of limestone from sources known to medieval craftsmen and from the monuments they built can be used in conjunction with stylistic and iconographic criteria to infer geographic origin of sculptures that have lost their histories. Limestone from 47 quarrying locations in France and from numerous medieval monuments have been subjected to neutron activation analysis (NAA) to form the nucleus of the Brookhaven Limestone Database. Even though the method and techniques of NAA are well established, this paper briefly summarizes the parameters and experimental conditions useful for determining those concentration variables for which limestone from different sources exhibits significant and reproducible differences.

  13. Limestones of western Newfoundland that magnetized before Devonian folding but after Middle Ordovician lithification

    SciTech Connect

    Hodych, J.P. )

    1989-01-01

    A positive fold test and a negative conglomerate test help determine when and how stable remanence was acquired in the Middle Ordovician Table Head Group limestones of the Port au Port Peninsula of Newfoundland. The limestones magnetized after lithification and incorporation as clasts into a Middle Ordovician breccia. Hence, the limestones do not carry a detrital or other primary remanence despite their very low conodont color alteration index. The remanence may be thermoviscous or diagenetic and was acquired before Devonian folding. This suggests the need for caution in interpreting paleomagnetic results from other early Paleozoic limestones whose remanence resides in magnetite of blocking temperature lower than 400C.

  14. Laser removal of water repellent treatments on limestone

    NASA Astrophysics Data System (ADS)

    Gómez-Heras, Miguel; Alvarez de Buergo, Mónica; Rebollar, Esther; Oujja, Mohamed; Castillejo, Marta; Fort, Rafael

    2003-12-01

    Protective and water repellent treatments are applied on stone materials used on buildings or sculptures of artistic value to reduce water intrusion without limiting the natural permeability to water vapour of the material. The effect of the wavelength associated with the laser removal of two water repellent treatments applied on limestone, Paraloid B-72, a copolymer of methyl acrylate and ethyl methacrylate, and Tegosivin HL-100, a modified polysiloxane resin, was investigated by using the four harmonics of a Q-switched Nd:YAG laser (1064, 532, 355 and 266 nm). The modifications induced on the surface of limestone samples by laser irradiation were studied using colorimetry, roughness measurements and scanning electron microscopy (SEM). The removal of the treatments was found to be dependent on the laser irradiation conditions and on the characteristics of the coatings. The fundamental laser radiation was effective in removing both treatments, but thermal alteration processes were induced on the constituent calcite crystals. The best results were obtained by irradiation in the near UV at 355 nm.

  15. Limestones distinguished by magnetic hysteresis in three-dimensional projections

    NASA Astrophysics Data System (ADS)

    Borradaile, G. J.; Hamilton, Tom

    2003-09-01

    Magnetic hysteresis data determine the suitability of rocks for paleomagnetic work, provide clues to paleo-environment and paleo-climate and they may characterize depositional environments for limestones. However, the variables chosen for conventional two-dimensional hysteresis plots, such as that of Day et al. [1977], are not always suitable to discriminate between samples. Distinguishing samples by their regression surfaces in 3D hysteresis space may be more successful in some cases [Borradaile and Lagroix, 2000] but a 2D projection with a less arbitrary viewing axis is preferable for routine reporting. We show that limestone samples are simply discriminated in a new 2D projection produced by projecting hysteresis data from three dimensions (x, y, z = Mr/Ms, Bcr, Bc) onto a plane containing the Mr/Ms axis. The orientation of the plane is controlled by its x-axis that is defined by a suitably selected Bcr/Bc ratio, most often in the magnetite PSD range, 2< (Bcr/Bc) < 4.

  16. Computerized Shawnee lime/limestone scrubbing model users manual

    SciTech Connect

    Anders, W.L.; Torstrick, R.L.

    1981-03-01

    The manual gives a general description of a computerized model for estimating design and cost of lime or limestone scrubber systems for flue gas desulfurization (FGD). It supplements PB80-123037 by extending the number of scrubber options which can be evaluated. It includes spray tower and venturi/spray-tower absorbers, forced oxidation systems, systems with absorber loop additives (MgO or adipic acid), revised design and economic premises, and other changes reflecting process improvements and variations. It describes all inputs and outputs, along with detailed procedures for using the model and all its options. The model is based on prototype scrubber data from the EPA/Shawnee test facility and should be useful to utility companies, as well as to architectural and engineering contractors who are involved in selecting and designing FGD facilities. As key features, the model provides estimates of capital investment and operating revenue requirements. It also provides a material balance, equipment list, and a breakdown of costs by processing areas. The primary uses of the model are to project comparative economics of lime and limestone FGD processes and to evaluate system alternatives prior to the development of a detailed design.

  17. Characterizing and modelling 'ghost-rock' weathered limestones

    NASA Astrophysics Data System (ADS)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  18. Bird Species Diversity in the Padawan Limestone Area, Sarawak

    PubMed Central

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd; Koon, Lim Chan; Rahman, Mustafa Abdul

    2011-01-01

    Bird surveys were conducted in the Padawan Limestone Area for seven days at each of two study sites, Giam and Danu, from August to December 2008. The purpose of the study was to compare the area’s bird species richness and abundance of bird species in other limestone areas and in other forest types. The study also compared the species richness and relative abundance of birds in undisturbed and disturbed areas at both study sites. Twenty mist nets were deployed for 12 hours daily. During this study period, direct observations of birds were also made. In all, 80 species from 34 families were recorded at both sites. At Giam, 120 birds were mist-netted. These birds represented 31 species from 16 families. The direct observations at Giam recorded 13 species from 11 families. In the undisturbed area, 21 species from 13 families were mist-netted, whereas in the disturbed area, 21 species from 10 families were mist-netted. In Danu, a total of 48 birds, representing 25 species from 12 families, were mist-netted. The observations at Danu recorded 34 species from 19 families. Twelve species from 7 families were mist-netted in the undisturbed area, whereas 18 species from 11 families were mist-netted in the disturbed area. Statistical analysis showed that the species diversity index differed significantly between undisturbed and disturbed areas. PMID:24575218

  19. Hydrogeology of the gray limestone aquifer in southern Florida

    USGS Publications Warehouse

    Reese, Ronald S.; Cunningham, Kevin J.

    2000-01-01

    Results from 35 new test coreholes and aquifer-test, water-level, and water-quality data were combined with existing hydrogeologic data to define the extent, thickness, hydraulic properties, and degree of confinement of the gray limestone aquifer in southern Florida. This aquifer, previously known to be present only in southeastern Florida (Miami-Dade, Broward, and Palm Beach Counties) below, and to the west of, the Biscayne aquifer, extends over most of central-south Florida, including eastern and central Collier County and southern Hendry County; it is the same as the lower Tamiami aquifer to the north, and it becomes the water-table aquifer and the upper limestone part of the lower Tamiami aquifer to the west. The aquifer generally is composed of gray, shelly, lightly to moderately cemented limestone with abundant shell fragments or carbonate sand, abundant skeletal moldic porosity, and minor quartz sand. The gray limestone aquifer comprises the Ochopee Limestone of the Tamiami Formation, and, in some areas, the uppermost permeable part of an unnamed formation principally composed of quartz sand. Underlying the unnamed formation is the Peace River Formation of the upper Hawthorn Group, the top of which is the base of the surficial aquifer system. Overlying the aquifer and providing confinement in much of the area is the Pinecrest Sand Member of the Tamiami Formation. The thickness of the aquifer is comparatively uniform, generally ranging from 30 to 100 feet. The unnamed formation part of the aquifer is up to 20 feet thick. The Ochopee Limestone accumulated in a carbonate ramp depositional system and contains a heterozoan carbonate-particle association. The principal rock types of the aquifer are pelecypod lime rudstones and floatstones and permeable quartz sands and sandstones. The pore types are mainly intergrain and separate vug (skeletal-moldic) pore spaces. The rock fabric and associated primary and secondary pore spaces combine to form a dual diffuse

  20. Enhancement of indirect sulphation of limestone by steam addition.

    PubMed

    Stewart, Michael C; Manovic, Vasilije; Anthony, Edward J; Macchi, Arturo

    2010-11-15

    The effect of water (H₂O(g)) on in situ SO₂ capture using limestone injection under (FBC) conditions was studied using a thermobalance and tube furnace. The indirect sulphation reaction was found to be greatly enhanced in the presence of H₂O(g). Stoichiometric conversion of samples occurred when sulphated with a synthetic flue gas containing 15% H₂O(g) in under 10 h, which is equivalent to a 45% increase in conversion as compared to sulphation without H₂O(g). Using gas pycnometry and nitrogen adsorption methods, it was shown that limestone samples sulphated in the presence of H₂O(g) undergo increased particle densification without any significant changes to pore area or volume. The microstructural changes and observed increase in conversion were attributed to enhanced solid-state diffusion in CaO/CaSO₄ in the presence of H₂O(g). Given steam has been shown to have such a strong influence on sulphation, whereas it had been previously regarded as inert, may prompt a revisiting of the classically accepted sulphation models and phenomena. These findings also suggest that steam injection may be used to enhance sulfur capture performance in fluidized beds firing low-moisture fuels such as petroleum coke.

  1. Stress-Induced Permeability Alterations in an Argillaceous Limestone

    NASA Astrophysics Data System (ADS)

    Selvadurai, A. P. S.; Głowacki, A.

    2017-05-01

    The paper presents the results of experiments that were conducted to determine the influence of a triaxial stress state on the evolution of the permeability of an argillaceous limestone. The limestone rock is found in the Ordovician rock formations above the Precambrian basement located in southern Ontario, Canada, which is being considered as a potential host rock for the construction of a deep ground repository for storing low- and intermediate-level nuclear waste. The paper presents the results of an extensive series of hydraulic pulse tests and steady-state tests that were conducted to determine the permeability alterations in zones that can experience levels of damage that can be present in vicinity of an excavated underground opening. A "state-space" relationship is developed to describe permeability evolution with the triaxial stress in the pre-failure regime. The permeability evolution in extensively damaged post-failure states of the rock is also investigated. It is shown that permeability alterations were four orders of magnitude higher as a result of significant damage to the material, which is an important consideration in establishing the efficiency of the host rock formation as a barrier for the long-term containment of radionuclide migration.

  2. Bird species diversity in the padawan limestone area, sarawak.

    PubMed

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd; Koon, Lim Chan; Rahman, Mustafa Abdul

    2011-12-01

    Bird surveys were conducted in the Padawan Limestone Area for seven days at each of two study sites, Giam and Danu, from August to December 2008. The purpose of the study was to compare the area's bird species richness and abundance of bird species in other limestone areas and in other forest types. The study also compared the species richness and relative abundance of birds in undisturbed and disturbed areas at both study sites. Twenty mist nets were deployed for 12 hours daily. During this study period, direct observations of birds were also made. In all, 80 species from 34 families were recorded at both sites. At Giam, 120 birds were mist-netted. These birds represented 31 species from 16 families. The direct observations at Giam recorded 13 species from 11 families. In the undisturbed area, 21 species from 13 families were mist-netted, whereas in the disturbed area, 21 species from 10 families were mist-netted. In Danu, a total of 48 birds, representing 25 species from 12 families, were mist-netted. The observations at Danu recorded 34 species from 19 families. Twelve species from 7 families were mist-netted in the undisturbed area, whereas 18 species from 11 families were mist-netted in the disturbed area. Statistical analysis showed that the species diversity index differed significantly between undisturbed and disturbed areas.

  3. Environmental Geophysics of a limestone aquifer in Western Maryland

    NASA Astrophysics Data System (ADS)

    Grgich, P.; Ackman, T.; Hammack, R.; Veloski, G.; Harbert, W.

    2002-05-01

    Many geophysical methods have been employed in characterizing carbonate bedrock to assess potential engineering and hydrologic problems. Traditionally, microgravity and resistivity have been utilized with some success. While viable, these methods are prone to inaccuracies due to variability in operator and data acquisition techniques. Additionally, these methods are often expensive and labor intensive. In order to more effectively characterize such terrains while limiting cost and eliminating as many sample errors as possible, other means must be investigated. This study utilizes electromagnetic conductivity (EM) using the Geonics EM-34 unit to characterize the limestone aquifer surrounding a quarry area in Western Maryland (Garrett County, Hoye's Run Mine, Keystone Mining). Correlative methods of ground penetrating radar (GPR), resistivity and field reconnaissance were used. While groundwater conductivity in a limestone aquifer is generally not significantly different than that of the surrounding bedrock, void space, clay or soil-filled passage, and cobble or gravel fill can be detected by utilizing EM. A correlation exists between detection of void space utilizing EM, GPR and resistivity when tracing known fractures and lineaments. Initial evaluation indicates that notable void and fracture can be located with the EM-34, and correlates with signal anomalies noted in both GPR and resistivity. Applications for these methods could significantly improve quarry design, mining approach, engineering assessment, hazard mitigation and remediation, and hydrologic evaluation, as well as potentially reducing costs and environmental impact associated with water pumping.

  4. Rare earths in the Leadville Limestone and its marble derivates

    USGS Publications Warehouse

    Jarvis, J.C.; Wildeman, T.R.; Banks, N.G.

    1975-01-01

    Samples of unaltered and metamorphosed Leadville Limestone (Mississippian, Colorado) were analyzed by neutron activation for ten rare-earth elements (REE). The total abundance of the REE in the least-altered limestone is 4-12 ppm, and their distribution patterns are believed to be dominated by the carbonate minerals. The abundances of the REE in the marbles and their sedimentary precursors are comparable, but the distribution patterns are not. Eu is enriched over the other REE in the marbles, and stratigraphically upward in the formation (samples located progressively further from the heat source), the light REE become less enriched relative to the heavy REE. The Eu anomaly is attributed to its ability, unique among the REE, to change from the 3+ to 2+ oxidation state. Whether this results in preferential mobilization of the other REE or whether this reflects the composition of the pore fluid during metamorphism is unknown. Stratigraphically selective depletion of the heavy REE may be attributed to more competition for the REE between fluid and carbonate minerals in the lower strata relative to the upper strata. This competition could have been caused by changes in the temperature of the pore fluid or to the greater resistance to solution of the dolomite in the lower parts of the formation than the calcite in the upper parts. ?? 1975.

  5. Colmenar limestone as a resource for built heritage

    NASA Astrophysics Data System (ADS)

    Fort, Rafael; Álvarez de Buergo, Mónica; Varas-Muriel, MªJosé; Mercedes Pérez-Monserrat, Elena

    2013-04-01

    The Colmenar stone (or Colmenar limestone) has been used in the construction of significant builidings of the Central area of Spain, such as the Royal Palace of Aranjuez (16th -18th centuries) or the Royal Palace of Madrid (18th century). Nowadays this building stone is still widely used, both for new construction and restoration works, as well as for the indoor ornamentation of emblematic buildings such as the Royal Theater of Madrid (20th century). There are many quarries from where this stone was exploited, being the most prestigious ones those located in Colmenar de Oreja, at 50 km Southeast the city of Madrid. The high quality of the stone in these quarries, its whiteness and pureness, made this locality the most relevant in these stonés extractive activities, concentrating the most relevant exploitations and providing the stone the denomination of the municipality (Colmenar). It was an underground mining extraction until the 20th century in order to reach the highest quality level of the mine, the so called "Banco Gordo" (Thick Bank). Generically known as moorland limestone, this rock belongs to the fluvial-lacustrine carbonates of the Upper Miocene Unit of the Tertiary Madrid's Basin. Its tonality mainly ranges from white to cream and even light grey. Under a petrographic point of view, this limestone is constituted by 40% of bioclasts (characea, ostracods and gasteropods), 20-30% of micritic matrix and 30-40% of sparitic cement. Therefore, it can be classified as a biomicrite/biosparite limestone or as a bioclastic packstone. Some particularities of these limestones regarding their appearance are related to some karstic processes they underwent linked to some dissolution phenomena during the Pliocene. All of this resulted on an abundance of cavities with terra rossa fillings, a non-soluble clayey residue, iron enriched, which is the responsible for the reddish and pinkish color that the Colmenar stone sometimes shows. These petrographic characteristics

  6. GPR investigations in galleries buried inside a karstified limestone formation

    NASA Astrophysics Data System (ADS)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-04-01

    A large scientific program of geophysical investigations is presently performed inside the Low-Noise Underground Laboratory (Laboratoire Souterrain à Bas Bruit / LSBB, Rustrel, France) which is an decomissioned underground missile control center, buried in a karstified limestone formation. One of the goals of this project is the understanding of the water circulation inside the structure. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity. The dip is around 25 degrees and vertical faults locally affect the structure. The studied zone is located in south-eastern France (Provence) and is characterized by a mediterranean climate with long dry periods and strong, short events of rain. This phenomenon induces large variations of water content within the karstified limestone from dry to saturated conditions. Analysis of the spatial and temporal variations of the water flow in a karstified limestones needs to define the geological context and the adequate geophysical methods. GPR offers a good tradeoff between resolution and ease of use on one hand and investigation depth on the other hand. We present some GPR profiles which have been acquired in April 2008 after a quite long and strong period of rain, inducing a complete water saturation inside the karstified massif. We used several RAMAC shielded antennas from 100 to 500 MHz. The longest profile is around 600 m long, with a 20 cm spacing, running from a raw to a concrete gallery. These data sets are characterized by a very good signal to noise ratio and a signal penetration, up to 18 meters. Signal processing includes very low frequency filtering, amplitude compensation, keeping lateral relative attenuation and ringing suppression. Final sections includes migration and time to depth conversion or depth migration. The estimated

  7. Geostatistical three-dimensional modeling of oolite shoals, St. Louis Limestone, southwest Kansas

    USGS Publications Warehouse

    Qi, L.; Carr, T.R.; Goldstein, R.H.

    2007-01-01

    In the Hugoton embayment of southwestern Kansas, reservoirs composed of relatively thin (<4 m; <13.1 ft) oolitic deposits within the St. Louis Limestone have produced more than 300 million bbl of oil. The geometry and distribution of oolitic deposits control the heterogeneity of the reservoirs, resulting in exploration challenges and relatively low recovery. Geostatistical three-dimensional (3-D) models were constructed to quantify the geometry and spatial distribution of oolitic reservoirs, and the continuity of flow units within Big Bow and Sand Arroyo Creek fields. Lithofacies in uncored wells were predicted from digital logs using a neural network. The tilting effect from the Laramide orogeny was removed to construct restored structural surfaces at the time of deposition. Well data and structural maps were integrated to build 3-D models of oolitic reservoirs using stochastic simulations with geometry data. Three-dimensional models provide insights into the distribution, the external and internal geometry of oolitic deposits, and the sedimentologic processes that generated reservoir intervals. The structural highs and general structural trend had a significant impact on the distribution and orientation of the oolitic complexes. The depositional pattern and connectivity analysis suggest an overall aggradation of shallow-marine deposits during pulses of relative sea level rise followed by deepening near the top of the St. Louis Limestone. Cemented oolitic deposits were modeled as barriers and baffles and tend to concentrate at the edge of oolitic complexes. Spatial distribution of porous oolitic deposits controls the internal geometry of rock properties. Integrated geostatistical modeling methods can be applicable to other complex carbonate or siliciclastic reservoirs in shallow-marine settings. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  8. Electromagnetic detection of deep freshwater lenses in a hyper-arid limestone terrain

    NASA Astrophysics Data System (ADS)

    Young, Michael E.; Macumber, Phillip G.; Donald Watts, M.; Al-Toqy, Nasser

    2004-12-01

    In the hyper-arid desert of Central Oman, freshwater lenses are found lying on a regional saline water table. These lenses have developed where recharge from infrequent cyclonic rainfall has collected in shallow depressions on the Tertiary limestones of the Central Plateau and in the catchments of ancient river channels draining the Plateau. Central-loop time-domain electromagnetic (TDEM) sounding was applied as a method of reconnaissance exploration for these lenses at two sites, a shallow depression extending over an area of 60 km 2 and a wadi gorge draining a catchment of 3400 km 2. These results were subsequently tested by drilling. In the case of the shallow depression, drilling intersected a freshwater lens up to 18 m thick at a depth of 92 m. TDEM resistivity-depth inversion showed that the corresponding high resistivity zone included both the lens and overlying unsaturated rocks, and that the depth to the saline interface could be accurately predicted. Where drilling failed to intersect a lens, TDEM inversion resulted in a consistently low resistivity zone in which the water table could not be resolved. By invoking the Archie formula modified for the presence of clays, it is thought that the higher resistivity of the vadose zone observed over the lens may be explained by a reduction in the clay conductivity factor resulting from higher pore-water resistivity. In the case of the wadi gorge, low regional resistivities were also recorded over the limestones on the survey margins, and high resistivity anomalies over the freshwater lens within and extending away from the gorge. Again, TDEM was found to be useful as a reconnaissance method and for mapping the depth to the underlying saline aquifer, but not for predicting the thickness of the overlying freshwater lens.

  9. Playing tricks to ions

    NASA Astrophysics Data System (ADS)

    Leibfried, Dietrich

    2017-01-01

    Ted Hänsch's career is defined by breaking new ground in experimental physics. Curiosity, vivid imagination, deep understanding, patience and tenacity are part of the winning formula, but perhaps an equally important ingredient may be Ted's favorite past-time of exploring new tricks in his "Spiellabor" (play-lab), that often resurfaced as key ingredients in rather serious experiments later. On the occasion of Ted's 75th birthday, a few past and potential future experiments with trapped ions are playfully surveyed here. Some of these tricks are already part of the trade, some are currently emerging and a few are mostly speculation today. Maybe some of the latter will be realized and even prove useful in the future.

  10. Study on the influence of the decoking agent on the activity of limestone in wet flue gas desulfurization

    NASA Astrophysics Data System (ADS)

    Li, Qianjun; Xu, Dongyang; Wu, Yunxia; Yu, Jin

    2017-01-01

    Influence of the main components of decoking agent (magnesium nitrate, aluminum nitrate, copper nitrate, ammonium nitrate and actual decoking agent) on the activity of limestone is studied in laboratory by MET method. Results show that magnesium nitrate, ammonium nitrate and copper nitrate almost has no effect on the activity of limestone. With the concentration increasing, aluminum nitrate has an increasing inhibition on the dissolution of limestone. Fly ash has inhibition on dissolution of limestone due to the blockage of limestone pore by fly ash. The actual decoking agent has almost no effect on the limestone.

  11. Young Children's Playfully Complex Communication: Distributed Imagination

    ERIC Educational Resources Information Center

    Alcock, Sophie

    2010-01-01

    This paper draws on research exploring young children's playful and humorous communication. It explores how playful activity mediates and connects children in complex activity systems where imagination, cognition, and consciousness become distributed across individuals. Children's playfulness is mediated and distributed via artefacts (tools, signs…

  12. Young Children's Playfully Complex Communication: Distributed Imagination

    ERIC Educational Resources Information Center

    Alcock, Sophie

    2010-01-01

    This paper draws on research exploring young children's playful and humorous communication. It explores how playful activity mediates and connects children in complex activity systems where imagination, cognition, and consciousness become distributed across individuals. Children's playfulness is mediated and distributed via artefacts (tools, signs…

  13. Crystallographic transformation of limestone during calcination under CO2.

    PubMed

    Valverde, Jose Manuel; Medina, Santiago

    2015-09-14

    The calcination reaction of limestone (CaCO3) to yield lime (CaO) is at the heart of many industrial applications as well as natural processes. In the recently emerged calcium-looping technology, CO2 capture is accomplished by the carbonation of CaO in a gas-solid reactor (carbonator). CaO is derived by the calcination of limestone in a calciner reactor under necessarily high CO2 partial pressure and high temperature. In situ X-ray diffraction (XRD) has been employed in this work to gain further insight into the crystallographic transformation that takes place during the calcination of limestone under CO2, at partial pressures (P) close to the equilibrium pressure (Peq) and at high temperature. Calcination under these conditions becomes extremely slow. The in situ XRD analysis presented here suggests the presence of an intermediate metastable CaO* phase stemming from the parent CaCO3 structure. According to the reaction mechanism proposed elsewhere, the exothermicity of the CaO* → CaO transformation and high values of P/Peq inhibit the nucleation of CaO at high temperatures. The wt% of CaO* remains at a relatively high level during slow calcination. Two diverse stages have been identified in the evolution of CaO crystallite size, L. Initially, L increases with CaCO3 conversion, following a logarithmic law. Slow calcination allows the crystallite size to grow up from a few nanometers at nucleation up to around 100 nm near the end of conversion. Otherwise, quick calcination at relatively lower CO2 concentrations limits CaO crystallite growth. Once calcination reaches an advanced state, the presence of CaO* drops to zero and the rate of increase of the CaO crystallite size is significantly hindered. Arguably, the first stage in CaO crystallite growth is driven by aggregation of the metastable CaO* nanocrystals, due to surface attractive forces, whereas the second one is consistent with sintering of the aggregated CaO crystals, and persists with time after full

  14. Deformation mechanisms and petrophysical properties of chert and limestone fault rocks within slope-to-basin succession (Gargano Promontory, Southern Italy)

    NASA Astrophysics Data System (ADS)

    Korneva, Irina; Tondi, Emanuele; Balsamo, Fabrizio; Agosta, Fabrizio

    2016-10-01

    In this work, we examine faults that crosscut limestone and chert rocks pertaining to a slope-to-basin succession of the eastern Gargano Promontory (southern Italy). Based on field data, microstructural observations, and quantitative analysis of cataclastic fabric, two stages of faulting are recognized. The first one, the pre-lithification faulting stage, took place within partially lithified sediments prior to their complete lithification. Differently, the second one, the post-lithification faulting stage, occurred within cohesive, well-lithified rocks. The structural properties of pre-lithification faults were likely controlled by the competence contrast between limestone and chert sediments. In fact, due to their different lithification stages, faulting occurred when chert was still not completely lithified, and hence was dragged along the fault planes. As a consequence, the pre-lithification fault cores are mainly composed of chert clasts. On the contrary, post-lithification fault cores are mostly made up of limestone clasts. The results of both microstructural and image analyses show that the carbonate fault rock includes a higher percentage of bigger clasts with lower values of angularity than the chert fault rock. Mercury-intrusion porosimetry indicates that the chert fault rock is characterized by larger pore throats and a lower amount of total porosity with respect to the limestone fault rock. The permeability values obtained for the limestone fault rock are lower than those for the chert fault rock, probably because of the lower amount of pore connectivity within the former fault rock. Results of this multidisciplinary work highlight the role played by cherty layers present within well-layered, slope-to-basin carbonate successions on both microtextural and petrophysical fault rock properties. Furthermore, these results increase our ability to predict how lithological heterogeneities and amount of lithification influence the deformation mechanisms, hence

  15. Upper Triassic limestones from the northern part of Japan: new insights on the Panthalassa Ocean and Hokkaido Island

    NASA Astrophysics Data System (ADS)

    Peyrotty, Giovan; Peybernes, Camille; Ueda, Hayato; Martini, Rossana

    2017-04-01

    In comparison with the well-known Tethyan domain, Upper Triassic limestones from the Panthalassa Ocean are still poorly known. However, these carbonates represent a unique opportunity to have a more accurate view of the Panthalassa Ocean during the Triassic. Their study will allow comparison and correlation of biotic assemblages, biostratigraphy, diagenesis, and depositional settings of different Triassic localities from Tethyan and Panthalassic domains. Moreover, investigation of these carbonates will provide data for taxonomic revisions and helps to better constrain palaeobiogeographic models. One of the best targets for the study of these carbonates is Hokkaido Island (north of Japan). Indeed, this island is a part of the South-North continuity of Jurassic to Paleogene accretionary complexes, going from the Philippines to Sakhalin Island (Far East Russia). Jurassic and Cretaceous accretionary complexes of Japan and Philippines contain Triassic mid-oceanic seamount carbonates from the western Panthalassa Ocean (Onoue & Sano, 2007; Kiessling & Flügel, 2000). They have been accreted either as isolated limestone slabs or as clasts and boulders, and are associated with mudstones, cherts, breccias and basaltic rocks. Two major tectonic units forming Hokkaido Island and containing Triassic limestones have been accurately explored and extensively sampled: the Oshima Belt (west Hokkaido) a Jurassic accretionary complex, and the Cretaceous Sorachi-Yezo Belt (central Hokkaido). The Sorachi-Yezo Belt is composed of Cretaceous accretionary complexes in the east and of Cretaceous clastic basin sediments deposited on a Jurassic basement in the west (Ueda, 2016), both containing Triassic limestones. The origin of this belt is still matter of debate especially because of its western part which is not in continuity with any other accretionary complex known in the other islands of Japan and also due to the lack of data in this region. One of the main goals of this study is to

  16. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    EPA Science Inventory

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  17. 76 FR 35396 - Black Hills National Forest, Mystic Ranger District, South Dakota, Section 30 Limestone Mining...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... Mining Project AGENCY: Forest Service, USDA. ACTION: Corrected Notice of intent to prepare an... the purpose of mining for chemical grade limestone within mining claims on National Forest System land... publication dates. A Notice of Availability for the Section 30 Limestone Mining Project Draft EIS...

  18. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    EPA Science Inventory

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  19. Adsorption and desorption of phosphate on limestone in experiments simulating seawater intrusion

    USDA-ARS?s Scientific Manuscript database

    The absorption and desorption of phosphorus on a large block of limestone was investigated using deionized water (DIW) and seawater. The limestone had a high affinity to adsorb phosphorus in DIW. Phosphate adsorption was significantly less in seawater, and more phosphorus was desorbed in the seawate...

  20. OPTIMIZATION OF A PULSED LIMESTONE BED REACTOR AT THE ARGO TUNNEL IN IDAHO SPRINGS, COLORADO

    EPA Science Inventory

    Acid Mine Drainage (AMD) is an unintended consequence of coal and metal mining that adversely affects thousands of miles of streams both in the eastern and western regions of the U.S. A novel AMD treatment process based on limestone based on limestone neutralization has been dev...

  1. OPTIMIZATION OF A PULSED LIMESTONE BED REACTOR AT THE ARGO TUNNEL IN IDAHO SPRINGS, COLORADO

    EPA Science Inventory

    Acid Mine Drainage (AMD) is an unintended consequence of coal and metal mining that adversely affects thousands of miles of streams both in the eastern and western regions of the U.S. A novel AMD treatment process based on limestone based on limestone neutralization has been dev...

  2. Major Oil Plays in Utah and Vicinity

    SciTech Connect

    Thomas C. Chidsey; Craig D. Morgan; Kevin McClure; Douglas A. Sprinkel; Roger L. Bon; Hellmut H. Doelling

    2003-12-31

    Utah oil fields have produced over 1.2 billion barrels (191 million m{sup 3}). However, the 13.7 million barrels (2.2 million m{sup 3}) of production in 2002 was the lowest level in over 40 years and continued the steady decline that began in the mid-1980s. The Utah Geological Survey believes this trend can be reversed by providing play portfolios for the major oil-producing provinces (Paradox Basin, Uinta Basin, and thrust belt) in Utah and adjacent areas in Colorado and Wyoming. Oil plays are geographic areas with petroleum potential caused by favorable combinations of source rock, migration paths, reservoir rock characteristics, and other factors. The play portfolios will include: descriptions and maps of the major oil plays by reservoir; production and reservoir data; case-study field evaluations; locations of major oil pipelines; identification and discussion of land-use constraints; descriptions of reservoir outcrop analogs; and summaries of the state-of-the-art drilling, completion, and secondary/tertiary techniques for each play. This report covers research activities for the sixth quarter of the project (October 1 through December 31, 2003). This work included describing outcrop analogs for the Jurassic Twin Creek Limestone and Mississippian Leadville Limestone, major oil producers in the thrust belt and Paradox Basin, respectively, and analyzing best practices used in the southern Green River Formation play of the Uinta Basin. Production-scale outcrop analogs provide an excellent view of reservoir petrophysics, facies characteristics, and boundaries contributing to the overall heterogeneity of reservoir rocks. They can be used as a ''template'' for evaluation of data from conventional core, geophysical and petrophysical logs, and seismic surveys. In the Utah/Wyoming thrust belt province, the Jurassic Twin Creek Limestone produces from subsidiary closures along major ramp anticlines where the low-porosity limestone beds are extensively fractured and sealed

  3. Producing Portland cement from iron and steel slags and limestone

    SciTech Connect

    Monshi, A.; Asgarani, M.K.

    1999-09-01

    The slags from blast furnace (iron making) and converter (steel making) after magnetic separation are mixed with limestone of six different compositions. The ground materials are fired in a pilot plant scale rotary kiln to 1,350 C for 1 h. The clinker is cooled, crushed, mixed with 3% gypsum, and ground to fineness of more than 3,300 cm{sub 2}/g. Initial and final setting times, consistency of standard paste, soundness, free CaO, and compressive and fractural strengths after 3, 7, and 28 days are measured. Samples with higher lime saturation factor developed higher C{sub 3}S content and better mechanical properties. Blending 10% extra iron slag to a cement composed of 49% iron slag, 43% calcined lime, and 8% steel slag kept the compressive strength of concrete above standard values for type I ordinary Portland cement.

  4. SLAM: a sodium-limestone concrete ablation model

    SciTech Connect

    Suo-Anttila, A.J.

    1983-12-01

    SLAM is a three-region model, containing a pool (sodium and reaction debris) region, a dry (boundary layer and dehydrated concrete) region, and a wet (hydrated concrete) region. The model includes a solution to the mass, momentum, and energy equations in each region. A chemical kinetics model is included to provide heat sources due to chemical reactions between the sodium and the concrete. Both isolated model as well as integrated whole code evaluations have been made with good results. The chemical kinetics and water migration models were evaluated separately, with good results. Several small and large-scale sodium limestone concrete experiments were simulated with reasonable agreement between SLAM and the experimental results. The SLAM code was applied to investigate the effects of mixing, pool temperature, pool depth and fluidization. All these phenomena were found to be of significance in the predicted response of the sodium concrete interaction. Pool fluidization is predicted to be the most important variable in large scale interactions.

  5. Identification of Calcium Sulphoaluminate Formation between Alunite and Limestone

    PubMed Central

    Kim, Hyung-Seok; Han, Gi-Chun; Ahn, Ji-Whan; Cho, Kye-Hong; Cho, Hee-Chan

    2009-01-01

    This study was carried out to identify the conditions of formation of calcium sulphoaluminate (3CaO·3Al2O3·CaSO4) by the sintering of a limestone (CaCO3) and alunite [K2SO4·Al2(SO4)3·4Al(OH)3] mixture with the following reagents: K2SO4, CaCO3, Al(OH)3, CaSO4·2H2O, and SiO2. When K2SO4, CaCO3, Al(OH)3, CaSO4·2H2O were mixed in molar ratios of 1:3:6:3 and sintered at 1,200∼1,300 °C, only 3CaO·3Al2O3·CaSO4 and calcium langbeinite (2CaSO4·K2SO4) were generated. With an amount of CaO that is less than the stoichiometric molar ratio, 3CaO·3Al2O3·CaSO4 was formed and anhydrite (CaSO4) did not react and remained behind. With the amount of CaSO4 that is less than the stoichiometric molar ratio, the amounts of 3CaO·3Al2O3·CaSO4 and 2CaSO4·K2SO4 decreased, and that of CaO·Al2O3 increased. In the K2SO4-CaO-Al2O3-CaSO4-SiO2 system, to stabilize the formation of 3CaO·3Al2O3·CaSO4, 2CaSO4·K2SO4, and β-2CaO·SiO2, the molar ratios of CaO: Al2O3: CaSO4 must be kept at 3:3:1 and that of CaO/SiO2, over 2.0; otherwise, the generated amount of 3CaO·3Al2O3·CaSO4 decreased and that of gehlenite (2CaO·Al2O3·SiO2) with no hydration increased quantitatively. Therefore, if all SO3(g) generated by the thermal decomposition of alunite reacts with CaCO3 (or CaO, the thermal decomposition product of limestone) to form CaSO4 in an alunite- limestone system, 1 mol of pure alunite reacts with 6 mol of limestone to form 1 mol of 3CaO·3Al2O3·CaSO4 and 1 mol of 2CaSO4·K2SO4. PMID:22346687

  6. Dissolution-induced preferential flow in a limestone fracture.

    PubMed

    Liu, Jishan; Polak, Amir; Elsworth, Derek; Grader, Avrami

    2005-06-01

    Flow in a rock fracture is surprisingly sensitive to the evolution of flow paths that develop as a result of dissolution. Net dissolution may either increase or decrease permeability uniformly within the fracture, or may form a preferential flow path through which most of the injected fluid flows, depending on the prevailing ambient mechanical and chemical conditions. A flow-through test was completed on an artificial fracture in limestone at room temperature under ambient confining stress of 3.5 MPa. The sample was sequentially circulated by water of two different compositions through the 1500 h duration of the experiment; the first 935 h by tap groundwater, followed by 555 h of distilled water. Measurements of differential pressures between the inlet and the outlet, fluid and dissolved mass fluxes, and concurrent X-ray CT imaging and sectioning were used to characterize the evolution of flow paths within the limestone fracture. During the initial circulation of groundwater, the differential pressure increased almost threefold, and was interpreted as a net reduction in permeability as the contacting asperities across the fracture are removed, and the fracture closes. With the circulation of distilled water, permeability initially reduces threefold, and ultimately increases by two orders of magnitude. This spontaneous switch from net decrease in permeability, to net increase occurred with no change in flow rate or applied effective stress, and is attributed to the evolving localization of flow path as evidenced by CT images. Based on the X-ray CT characterizations, a flow path-dependent flow model was developed to simulate the evolution of flow paths within the fracture and its influence on the overall flow behaviors of the injected fluid in the fracture.

  7. Geochemistry, environmental and provenance study of the Middle Miocene Leitha limestones (Central Paratethys)

    NASA Astrophysics Data System (ADS)

    Ali, Ahmed; Wagreich, Michael

    2017-06-01

    Mineralogical, major, minor, REE and trace element analyses of rock samples were performed on Middle Miocene limestones (Leitha limestones, Badenian) collected from four localities from Austria (Mannersdorf, Wöllersdorf, Kummer and Rosenberg quarries) and the Fertőrákos quarry in Hungary. Impure to pure limestones (i.e. limited by Al2O3 contents above or below 0.43 wt. %) were tested to evaluate the applicability of various geochemical proxies and indices in regard to provenance and palaeoenvironmental interpretations. Pure and impure limestones from Mannersdorf and Wöllersdorf (southern Vienna Basin) show signs of detrital input (REEs = 27.6 ± 9.8 ppm, Ce anomaly = 0.95 ± 0.1 and the presence of quartz, muscovite and clay minerals in impure limestones) and diagenetic influence (low contents of, e.g., Sr = 221 ± 49 ppm, Na is not detected, Ba = 15.6 ± 8.8 ppm in pure limestones). Thus, in both limestones the reconstruction of original sedimentary palaeoenvironments by geochemistry is hampered. The Kummer and Fertőrákos (Eisenstadt-Sopron Basin) comprise pure limestones (e.g., averages Sr = 571 ± 139 ppm, Na = 213 ± 56 ppm, Ba = 21 ± 4 ppm, REEs = 16 ± 3 ppm and Ce anomaly = 0.62 ± 0.05 and composed predominantly of calcite) exhibiting negligible diagenesis. Deposition under a shallow-water, well oxygenated to intermittent dysoxic marine environment can be reconstructed. Pure to impure limestones at Rosenberg-Retznei (Styrian Basin) are affected to some extent by detrital input and volcano-siliciclastic admixture. The Leitha limestones at Rosenberg have the least diagenetic influence among the studied localities (i.e. averages Sr = 1271 ± 261 ppm, Na = 315 ± 195 ppm, Ba = 32 ± 15 ppm, REEs = 9.8 ± 4.2 ppm and Ce anomaly = 0.77 ± 0.1 and consist of calcite, minor dolomite and quartz). The siliciclastic sources are characterized by immobile elemental ratios (i.e. La/Sc and Th/Co) which apply not only for the siliciclastics, but also for marls and

  8. Thermal strengthening of limestone: monument preservation during fire

    NASA Astrophysics Data System (ADS)

    Heap, Michael; Lavallee, Yan; Benson, Philip; Hess, Kai-Uwe; Dingwell, Donald

    2010-05-01

    The use of natural rocks in the construction of buildings and monuments predates the use of commercially engineered materials such as concrete. Such building material can be subject to elevated temperatures in the misfortunate event of a fire. In civil engineering, it is generally appreciated that the strength of rock is decreased when it is or has been exposed to elevated temperatures. This is due the formation of thermal microcracks, a result of the thermal expansion mismatch between different minerals in the rock. Even today, fire is by no means an uncommon occurrence and approximately one historic building is lost to fire in the European Union every day (COST C17 2001). A large number of historically significant buildings and monuments are constructed from carbonate material. However, could the paradigm of thermal weakening of limestone construction material be in part, a paradox? We report new findings on the thermal strengthening of the Solnhofen limestone (Solnhofen, Germany), a carbonate rock traditionally used in construction of building and statues in central Europe. Two types of deformation experiments were performed to investigate: (1) the strength of samples at elevated temperatures (i.e. during fire) and (2) the strength of samples at room temperature after heat-treatment (i.e. after fire). During experimentation, microcracking was monitored by the output of acoustic emissions (AE). Thermo-gravimetric (TG) analysis was also undertaken to measure the mass loss during heating. For the experiments ‘during fire', samples were heated to temperatures of 25°, 200°, 400°, 500°, 600°, 650° and 800°C at a controlled rate of 5°C/min and deformed until failure in a uniaxial press at a constant strain rate of 10-5 s-1. For the experiments ‘after fire', samples were heat-treated to each 100°C increment up to 800°C, they were then cooled at the same rate and their strength tested at room temperature. The mechanical data demonstrate that, during fire

  9. Origin of minor limestone-shale cycles: Climatically induced or diagenetic?

    NASA Astrophysics Data System (ADS)

    Hallam, A.

    1986-07-01

    The opinion is widely held that each limestone bed in minor limestone-shale cyclic sequences, however modified subsequently by diagenesis, reflects an environmental event. On the assumption that this is true, attempts have recently been made to relate limestone-shale cycles to climatic variations affected by “Milankovitch” orbital cycles. A test is proposed and illustrated mainly with reference to the Blue Lias Formation of Dorset, England, that appears to indicate that many limestones can be produced solely by rhythmic unmixing of CaCO3 during diagenesis. Unless such limestones can be clearly distinguished from those that record genuine environmental signals, orbital cycle analysis based on such sequences will give meaningless results.

  10. Toxicity of acid mine pit lake water remediated with limestone and phosphorus.

    PubMed

    Neil, Luke L; McCullough, Clint D; Lund, Mark A; Evans, Louis H; Tsvetnenko, Yuri

    2009-11-01

    Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH approximately 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and (c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

  11. Dissolution rate of limestone for wet flue gas desulfurization in the presence of sulfite.

    PubMed

    Xiang, Gao; Rui-tang, Guo; Hong-lei, Ding; Zhong-yang, Luo; Ke-fa, Cen

    2009-09-15

    Limestone dissolution rate was measured by a pH-stat method with CO(2) sparging and dissolved sulfite. The dissolution rate of limestone under these conditions was found to be controlled by mass transfer and surface kinetics. As can be seen from the results, in the presence of sulfite, limestone dissolution rate increases with increasing stirring speed, reaction temperature and CO(2) partial pressure. The crystallinity of limestone has a great impact on the dissolution rate: The lower the value of the crystallinity of limestone is, the higher the dissolution rate is. The presence of sulfite promotes the dissolution rate when pH value is below 5.5 but inhibits it when pH value is above 5.5.

  12. Toxicity of acid mine pit lake water remediated with limestone and phosphorus

    SciTech Connect

    Neil, L.L.; McCullough, C.D.; Lund, M.A.; Evans, L.H.; Tsvetnenko, Y.

    2009-11-15

    Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH similar to 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

  13. Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash

    SciTech Connect

    De Weerdt, K.; Haha, M. Ben; Le Saout, G.; Kjellsen, K.O.; Justnes, H.; Lothenbach, B.

    2011-03-15

    The effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated in this study using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis. The presence of limestone powder led to the formation of hemi- and monocarbonate and to a stabilisation of ettringite compared to the limestone-free cements, where a part of the ettringite converted to monosulphate. Thus, the presence of 5% of limestone led to an increase of the volume of the hydrates, as visible in the increase in chemical shrinkage, and an increase in compressive strength. This effect was amplified for the fly ash/limestone blended cements due to the additional alumina provided by the fly ash reaction.

  14. FMC limestone double-alkali flue gas desulfurization process: Pilot plant testing: Final report

    SciTech Connect

    Troupe, J.S.; Shepley, D.C.

    1987-07-01

    This report documents pilot plant testing of a 3 MW (9500 acfm equivalent flue gas flow) FMC limestone double alkali FGD process operating on a slipstream of a commercial 420 MW boiler burning 3.5% sulfur coal. The report discusses the rationale behind EPRI's decision to participate in the testing aspects of this project, the history of the development of limestone double alkali technology, and the chemistry involved in this technology's operation. The largest part of the report is devoted to the results obtained from tests conducted during 65 days of pilot plant operation. All of the major raw and reduced operating and analytical data taken during testing are reproduced in the appendices to the report, along with quality assurance information to support the validity of the data obtained. The report discusses the test results in detail and presents technical observations regarding their implications. The FMC limestone double alkali FGD process (1) can consistently remove 92 to 93% of SO/sub 2/ from high-sulfur coal flue gas, (2) can achieve high limestone utilization and low soda ash losses, (3) produces a manageable waste filter cake, (4) is highly tolerant of upsets in limestone feed, soda ash makeup, and regeneration residence time, and (5) presents no unusual safety or environmental problems. The process, like conventional limestone scrubbing, shows some adverse effects of increasing soluble magnesium concentration on solids quality and requires a finely ground limestone feed material to achieve high limestone utilization. However, neither limestone grind nor magnesium concentration appears to affect SO/sub 2/ removal efficiency. The report suggests specific lines of future developmental work and future demonstration testing to enhance the attractiveness of this process to the electric utility industry. A bibliography of limestone double alkali literature is included. 3 refs., 25 figs., 4 tabs.

  15. Geochemical controls on phosphatic carbonate deposition: A case study of the Cambrian Thorntonia Limestone, southern Georgina Basin, Australia

    NASA Astrophysics Data System (ADS)

    Creveling, J. R.; Johnston, D. T.; Poulton, S.; Kotrc, B.; Marz, C.; Schrag, D. P.; Knoll, A.

    2012-12-01

    Phosphorite and phosphatic carbonate define a spectrum of sedimentary lithologies enriched in authigenic apatite. The punctuated temporal distribution (Cook and McElhinny, 1979) and evolving spatial distribution (Brasier and Callow, 2007) of phosphates through Earth history suggest that unique and restrictive physio-chemical conditions govern the formation of authigenic apatite in time and space. A global phosphogenic episode that coincides with major evolutionary changes across the Ediacaran—Cambrian boundary (Cook, 1992) preserves a detailed record of early animal diversification (e.g., Dornbos, 2010). Phosphorus is a limiting nutrient for biological productivity. Thus, changes in the source and/or sink of this element have been invoked to explain fluctuations in organic carbon burial and oxidant accumulation over this interval. What conditions and mechanisms controlled the opening and closure of the global Ediacaran-Cambrian phosphogenic window? We present sedimentological, petrographic, and geochemical data from the Cambrian Series 2-3 Thorntonia Limestone, Georgina Basin, Australia, one of the youngest Cambrian localities displaying widespread apatite nucleation and exceptional phosphatic preservation of small shelly fossils. Integrated with sedimentology, geochemical data—iron and phosphorus speciation data, stable carbon isotopes and trace element concentrations—provide a basin-scale environmental context for interpreting phosphate deposition. Phosphorus enrichment occurred during times of expanded anoxic, ferruginous conditions in subsurface water masses. This suggests that, in addition to organic matter delivery, phosphorus adsorbed to, and co-precipitated with, iron minerals forming in the water column provided a significant source to sediments. Sedimentary organic matter played a second important role, ensuring anoxic pore water conditions needed to remobilize phosphorus from primary sources within accumulating carbonates. Petrology reveals that

  16. Niger Delta play types, Nigeria

    SciTech Connect

    Akinpelu, A.O.

    1995-08-01

    Exploration databases can be more valuable when sorted by play type. Play specific databases provide a system to organize E & P data used in evaluating the range of values of parameters for reserve estimation and risk assessment. It is important both in focusing the knowledge base and in orienting research effort. A play in this context is any unique combination of trap, reservoir and source properties with the right dynamics of migration and preservation that results in hydrocarbon accumulation. This definitions helps us to discriminate the subtle differences found with these accumulation settings. About 20 play types were identified around the Niger Delta oil province in Nigeria. These are grouped into three parts: (1) The proven plays-constituting the bulk of exploration prospects in Nigeria today. (2) The unproven or semi-proven plays usually with some successes recorded in a few tries but where knowledge is still inadequate. (3) The unproven or analogous play concept. These are untested but geologically sound ideas which may or may not have been tried elsewhere. With classification and sub grouping of these play types into specific databases, intrinsic attributes and uniqueness of each of them with respect to the four major risk elements and the eight parameters for reserve estimation can be better understood.

  17. Landing and Oviposition Responses of Rhagoletis indifferens (Dipt., Tephritidae) on Sweet Cherry Treated with Kaolin- and Limestone-Based Products

    USDA-ARS?s Scientific Manuscript database

    Kaolin- and limestone-based products were compared for their effects on landing and oviposition on sweet cherry by Rhagoletis indifferens Curran (Dipt., Tephritidae). Surround (95% calcined kaolin), Cocoon (100% hydrous kaolin), Eclipse (>97% limestone), and Purshade (62.5% limestone) were studied....

  18. Play Therapy: A Review

    ERIC Educational Resources Information Center

    Porter, Maggie L.; Hernandez-Reif, Maria; Jessee, Peggy

    2009-01-01

    This article discusses the current issues in play therapy and its implications for play therapists. A brief history of play therapy is provided along with the current play therapy approaches and techniques. This article also touches on current issues or problems that play therapists may face, such as interpreting children's play, implementing…

  19. Play Therapy: A Review

    ERIC Educational Resources Information Center

    Porter, Maggie L.; Hernandez-Reif, Maria; Jessee, Peggy

    2009-01-01

    This article discusses the current issues in play therapy and its implications for play therapists. A brief history of play therapy is provided along with the current play therapy approaches and techniques. This article also touches on current issues or problems that play therapists may face, such as interpreting children's play, implementing…

  20. Stratigraphy and sedimentology of the Upper Cretaceous (Campanian) Anacacho Limestone, Texas, USA

    USGS Publications Warehouse

    Swezey, C.S.; Sullivan, E.C.

    2004-01-01

    The Upper Cretaceous Anacacho Limestone is exposed in outcrops between the cities of San Antonio and Del Rio, Texas. A detailed study of four outcrops (Blanco Creek section, Sabinal River section, Seco Creek section, Hondo Creek section) shows that the Anacacho Limestone rests on the Upson Clay (which contains fauna of early Campanian age) and is overlain by the Corsicana Marl (which contains fauna of early Maastrichtian age). An unconformity within the Anacacho Limestone is used herein to separate the limestone into a lower member and an upper member. The lower Anacacho member contains fauna of early Campanian age, whereas the upper Anacacho member contains fauna of middle Campanian age. The lower Anacacho member consists predominantly of wackestones to packstones, which are overlain by packstones to grainstones capped by the unconformity. This unconformity is interpreted as a marine flooding surface, delineating a transition from carbonate grainstones deposited in shallow water (<30 m depth) to a chalk deposited in deeper water. Above the unconformity, the upper Anacacho member is characterized by a chalk, overlain by wackestones and packstones. The uppermost section of the Anacacho Limestone consists of packstones and grainstones with abundant and diverse fossils. Most of the Anacacho Limestone developed in relatively shallow water (<50 m depth) leeward of a large carbonate build-up (possibly a rudistid reef) that now comprises the Anacacho Mountains. The environment, however, was open to marine water throughout deposition of the Anacacho Limestone. ?? 2004 Elsevier Ltd. All rights reserved.

  1. Modeling of Hydration, Compressive Strength, and Carbonation of Portland-Limestone Cement (PLC) Concrete

    PubMed Central

    Wang, Xiao-Yong

    2017-01-01

    Limestone is widely used in the construction industry to produce Portland limestone cement (PLC) concrete. Systematic evaluations of hydration kinetics, compressive strength development, and carbonation resistance are crucial for the rational use of limestone. This study presents a hydration-based model for evaluating the influences of limestone on the strength and carbonation of concrete. First, the hydration model analyzes the dilution effect and the nucleation effect of limestone during the hydration of cement. The degree of cement hydration is calculated by considering concrete mixing proportions, binder properties, and curing conditions. Second, by using the gel–space ratio, the compressive strength of PLC concrete is evaluated. The interactions among water-to-binder ratio, limestone replacement ratio, and strength development are highlighted. Third, the carbonate material contents and porosity are calculated from the hydration model and are used as input parameters for the carbonation model. By considering concrete microstructures and environmental conditions, the carbon dioxide diffusivity and carbonation depth of PLC concrete are evaluated. The proposed model has been determined to be valid for concrete with various water-to-binder ratios, limestone contents, and curing periods. PMID:28772472

  2. Modeling of Hydration, Compressive Strength, and Carbonation of Portland-Limestone Cement (PLC) Concrete.

    PubMed

    Wang, Xiao-Yong

    2017-01-26

    Limestone is widely used in the construction industry to produce Portland limestone cement (PLC) concrete. Systematic evaluations of hydration kinetics, compressive strength development, and carbonation resistance are crucial for the rational use of limestone. This study presents a hydration-based model for evaluating the influences of limestone on the strength and carbonation of concrete. First, the hydration model analyzes the dilution effect and the nucleation effect of limestone during the hydration of cement. The degree of cement hydration is calculated by considering concrete mixing proportions, binder properties, and curing conditions. Second, by using the gel-space ratio, the compressive strength of PLC concrete is evaluated. The interactions among water-to-binder ratio, limestone replacement ratio, and strength development are highlighted. Third, the carbonate material contents and porosity are calculated from the hydration model and are used as input parameters for the carbonation model. By considering concrete microstructures and environmental conditions, the carbon dioxide diffusivity and carbonation depth of PLC concrete are evaluated. The proposed model has been determined to be valid for concrete with various water-to-binder ratios, limestone contents, and curing periods.

  3. Preliminary microfacies analysis and cyclicity of the Wahoo Limestone, Lisburne Field, North Slope, Alaska

    SciTech Connect

    Morgan, S.K.; Watts, K.F.

    1995-05-01

    A well from the Lisburne field near Prudhoe Bay was examined in core, thin section, and on well logs for comparison with Wahoo Limestone in the Arctic National Wildlife Refuge (ANWR). Carbonate cycles (parasequences) are well developed in both areas but the greater abundance of terrigenous sediment and associated carbonate facies indicate that the study well is located in a more landward position on the Wahoo carbonate ramp, closer to a source of terrigenous sediment. This report presents the preliminary results of microfacies analyses that have been conducted on 424 of a total 1,115 thin sections from the study well. The stratigraphic nomenclature extended from ANWR (the type locality of the Wahoo Limestone) is different that the terminology previously used for the subsurface Lisburne Group near Prudhoe Bay. We distinguish informal lower and upper members within the Mississippian to Pennsylvanian Wahoo Limestone which overlies the Mississippian Alapah Limestone. Our upper Alapah corresponds to the middle Alapah of previous workers. Our lower Wahoo Limestone member corresponds to the upper Alapah of previous workers. Our upper Wahoo Limestone member corresponds to the previous Wahoo Limestone and is the major hydrocarbon reservoir at the Lisburne field, which is characterized by well-developed carbonate cycles (parasequences).

  4. Rehabilitation of lands mined for limestone in the Indian desert

    USGS Publications Warehouse

    Sharma, K.D.; Kumar, S.; Gough, L.P.

    2000-01-01

    In the Indian desert, the economics of mining is second only to agriculture in importance. However, research on the rehabilitation of land disturbed by mining has only recently received serious attention. An attempt has been made to determine both the qualitative and quantitative success of rehabilitation plans used to revegetate limestone mine spoils in an area near Barna, northwest arid India. Rehabilitation success was achieved using a combination of rainwater harvesting techniques, soil amendment application approaches, plant establishment methods and the selection of appropriate germplasm material (trees, shrubs and grasses). It is expected that the resulting vegetative cover will be capable of self-perpetuation under natural conditions while at the same time meeting the land-use needs of the local people. The minespoils have adequate levels of the major nutrients (except P, Mo and Se) for proper plant and grazing animal health. Levels of organic matter are low whereas total B concentrations are exceptionally high. Also, the population of soil fungi, Azotobactor, and nitrifying bacteria is negligible. Enhanced plant growth was achieved in treated plots, compared to control plots, where spoil moisture storage was improved by 5-45 per cent. Due to the decomposition of farmyard manure and nitrogen fixation by planted leguminous plant species, the electrical conductance of treated mine spoils increased threefold, CaCO3 content decreased from 20??0 to 5??2 per cent, and organic carbon, P, K, and biological activity increased significantly. The rehabilitation protocol used at the site appears to have been successful because plant self-regeneration is occurring. The increased diversity of woody perennials resulted in 'dominance' being better shared among species and 'evenness' being increased within the plant community elements. The early to mid-successional trends are continuing for six years following initial rehabilitation. This study developed methods for the

  5. ARD remediation with limestone in a CO2 pressurized reactor

    USGS Publications Warehouse

    Sibrell, Philip L.; Watten, Barnaby J.; Friedrich, Andrew E.; Vinci, Brian J.

    2000-01-01

    We evaluated a new process for remediation of acid rock drainage (ARD). The process treats ARD with intermittently fluidized beds of granular limestone maintained within a continuous flow reactor pressurized with CO2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Department of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using an ARD flow of 227 L/min. The ARD had the following characteristics: pH, 3.1; temperature, 10 °C; dissolved oxygen, 6.4 mg/L; acidity, 260 mg/L; total iron, 21 mg/L; aluminum, 22 mg/L; manganese, 7.5 mg/L; and conductivity, 1400 μS/cm. In all cases tested, processed ARD was net alkaline with mean pH and alkalinities of 6.7 and 59 mg/L at a CO2 pressure of 0 kPa, 6.6 and 158 mg/L at 34 kPa, 7.4 and 240 mg/L at 82 kPa, and 7.4 and 290 mg/L at 117 kPa. Processed ARD alkalinities were correlated to the settled bed depth (p<0.001) and CO2 pressure (p<0.001). Iron, aluminum, and manganese removal efficiencies of 96%, 99%, and 5%, respectively, were achieved with filtration following treatment. No indications of metal hydroxide precipitation or armoring of the limestone were observed. The surplus alkalinity established at 82 kPa was successful in treating an equivalent of 1136 L/min (five-fold dilution) of the combined three ARD streams entering the Toby Creek Plant. This side-stream capability provides savings in treatment unit scale as well as flexibility in treatment effect. The capability of the system to handle higher influent acidity was tested by elevating the acidity to 5000 mg/L with sulfuric acid. Net alkaline effluent was produced, indicating applicability of the process to highly acidic ARD.

  6. Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia.

    PubMed

    Foon, Junn Kitt; Clements, Gopalasamy Reuben; Liew, Thor-Seng

    2017-01-01

    Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed. To address this knowledge gap, we systematically surveyed the terrestrial malacofauna of 12 limestone hills that, based on our opinion, are a representation of the limestone land snail assemblages within the State. Our inventory yielded high sampling completeness (>85%). We found 122 species of land snails, of which 34 species were unique to one of the surveyed hills. We identified 30 species that are potentially new to science. The number of land snail species recorded at each hill ranged between 39 and 63 species. Four of the sampled limestone hills namely, Prk 01 G. Tempurung, Prk 55 G. Pondok, Prk 47 Kanthan, and Prk 64 Bt Kepala Gajah, have high levels of species richness and unique species, representing 91% of the total species recorded in this study. We identified two clusters of limestone hills in central Perak with distinct differences in land snail species composition - a northern hill cluster on elevated granite bedrock and southern hill cluster in a low-lying valley surrounded by alluvial soils. As limestone hills continue to be quarried to meet the cement demand, the four identified limestone hills, along with other hills from the two clusters, warrant urgent conservation attention in order to maintain high species diversity within Perak's terrestrial malacofauna.

  7. Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia

    PubMed Central

    Foon, Junn Kitt; Clements, Gopalasamy Reuben; Liew, Thor-Seng

    2017-01-01

    Abstract Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed. To address this knowledge gap, we systematically surveyed the terrestrial malacofauna of 12 limestone hills that, based on our opinion, are a representation of the limestone land snail assemblages within the State. Our inventory yielded high sampling completeness (>85%). We found 122 species of land snails, of which 34 species were unique to one of the surveyed hills. We identified 30 species that are potentially new to science. The number of land snail species recorded at each hill ranged between 39 and 63 species. Four of the sampled limestone hills namely, Prk 01 G. Tempurung, Prk 55 G. Pondok, Prk 47 Kanthan, and Prk 64 Bt Kepala Gajah, have high levels of species richness and unique species, representing 91% of the total species recorded in this study. We identified two clusters of limestone hills in central Perak with distinct differences in land snail species composition – a northern hill cluster on elevated granite bedrock and southern hill cluster in a low-lying valley surrounded by alluvial soils. As limestone hills continue to be quarried to meet the cement demand, the four identified limestone hills, along with other hills from the two clusters, warrant urgent conservation attention in order to maintain high species diversity within Perak’s terrestrial malacofauna. PMID:28769723

  8. Effects of particle size distribution on limestone dissolution in wet FGD process applications

    SciTech Connect

    Ukawa, Naohiko; Takashina, Toru; Shinoda, Naoharu ); Shimizu, Taku )

    1993-08-01

    The kinetics of limestone dissolution in the wet type flue gas desulfurization (FGD) processes has been studied. The rates of dissolution and particle size reduction were measured in both batch and continuous reaction systems for limestone of different size distributions. A predictive model was developed based on mass transfer mechanisms. It was in good agreement with experimental data. Moreover, the rate of dissolution for 25 limestones of different compositions and size distributions were measured in apparatus with a sulfur dioxide absorber which simulated FGD processes. The model was also in good agreement with these results. 11 refs., 8 figs., 2 tabs.

  9. Desulfurization with a modified limestone formulation in an industrial CFBC boiler

    SciTech Connect

    Young Goo Park; Seung Ho Kim

    2006-02-01

    This work presents a practical result of experimental investigation of the limestone particle size effect on de-SOx from a circulating fluidized bed combustion (CFBC) boiler that burns domestic anthracite and is the first industrial scale in Korea. Because of combustion problems such as clinker formation, fine limestone has not been used as a desulfurization agent. The present test, however, showed that higher content (up to 50%) of the particles under 0.1 mm did not entail any malfunction in a modern CFBC system. In addition, the desulfurization efficiency was found to be comparable to the old mode of limestone sorbents. 17 refs., 4 figs., 3 tabs.

  10. Playing in the Gutters: Enhancing Children's Cognitive and Social Play.

    ERIC Educational Resources Information Center

    Dinwiddie, Sue A.

    1993-01-01

    Adding plastic gutters to the nursery school's sand area began as a science curriculum enhancement and evolved into a whole curriculum that stimulated cognitive exploration, cooperative dramatic play, language enhancement, and general fun. The children manipulated the gutters and materials such as sand, water, buckets, and tennis balls in a…

  11. Playing in the Gutters: Enhancing Children's Cognitive and Social Play.

    ERIC Educational Resources Information Center

    Dinwiddie, Sue A.

    1993-01-01

    Adding plastic gutters to the nursery school's sand area began as a science curriculum enhancement and evolved into a whole curriculum that stimulated cognitive exploration, cooperative dramatic play, language enhancement, and general fun. The children manipulated the gutters and materials such as sand, water, buckets, and tennis balls in a…

  12. Symbolic play and language development.

    PubMed

    Orr, Edna; Geva, Ronny

    2015-02-01

    Symbolic play and language are known to be highly interrelated, but the developmental process involved in this relationship is not clear. Three hypothetical paths were postulated to explore how play and language drive each other: (1) direct paths, whereby initiation of basic forms in symbolic action or babbling, will be directly related to all later emerging language and motor outputs; (2) an indirect interactive path, whereby basic forms in symbolic action will be associated with more complex forms in symbolic play, as well as with babbling, and babbling mediates the relationship between symbolic play and speech; and (3) a dual path, whereby basic forms in symbolic play will be associated with basic forms of language, and complex forms of symbolic play will be associated with complex forms of language. We micro-coded 288 symbolic vignettes gathered during a yearlong prospective bi-weekly examination (N=14; from 6 to 18 months of age). Results showed that the age of initiation of single-object symbolic play correlates strongly with the age of initiation of later-emerging symbolic and vocal outputs; its frequency at initiation is correlated with frequency at initiation of babbling, later-emerging speech, and multi-object play in initiation. Results support the notion that a single-object play relates to the development of other symbolic forms via a direct relationship and an indirect relationship, rather than a dual-path hypothesis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Acid neutralization within limestone sand reactors receiving coal mine drainage

    USGS Publications Warehouse

    Watten, B.J.; Sibrell, P.L.; Schwartz, M.F.

    2005-01-01

    Pulsed bed treatment of acid mine drainage (AMD) uses CO2 to accelerate limestone dissolution and intermittent fluidization to abrade and carry away metal hydrolysis products. Tests conducted with a prototype of 60 L/min capacity showed effective removal of H+ acidity over the range 196-584 mg/L (CaCO3) while concurrently generating surplus acid neutralization capacity. Effluent alkalinity (mg/L CaCO3) rose with increases in CO2 (DC, mg/L) according to the model Alkalinity = 31.22 + 2.97(DC)0.5, where DC was varied from 11-726 mg/L. Altering fluidization and contraction periods from 30 s/30 s to 10 s/50 s did not influence alkalinity but did increase energy dissipation and bed expansion ratios. Field trials with three AMD sources demonstrated the process is capable of raising AMD pH above that required for hydrolysis and precipitation of Fe3+ and Al3+ but not Fe2+ and Mn2+. Numerical modeling showed CO2 requirements are reduced as AMD acidity increases and when DC is recycled from system effluent. ?? 2005 Elsevier Ltd. All rights reserved.

  14. Acid neutralization within limestone sand reactors receiving coal mine drainage.

    PubMed

    Watten, Barnaby J; Sibrell, Philip L; Schwartz, Michael F

    2005-09-01

    Pulsed bed treatment of acid mine drainage (AMD) uses CO2 to accelerate limestone dissolution and intermittent fluidization to abrade and carry away metal hydrolysis products. Tests conducted with a prototype of 60 L/min capacity showed effective removal of H+ acidity over the range 196-584 mg/L (CaCO3) while concurrently generating surplus acid neutralization capacity. Effluent alkalinity (mg/L CaCO3) rose with increases in CO2 (DC, mg/L) according to the model Alkalinity=31.22+2.97(DC)0.5, where DC was varied from 11-726 mg/L. Altering fluidization and contraction periods from 30s/30s to 10s/50s did not influence alkalinity but did increase energy dissipation and bed expansion ratios. Field trials with three AMD sources demonstrated the process is capable of raising AMD pH above that required for hydrolysis and precipitation of Fe3+ and Al3+ but not Fe2+ and Mn2+. Numerical modeling showed CO2 requirements are reduced as AMD acidity increases and when DC is recycled from system effluent.

  15. Deposition and diagenesis of Miocene limestones, Senkang Basin, Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    Mayall, M. J.; Cox, M.

    1988-09-01

    Miocene Knoll-reef limestones form gas reservoirs in the East Senkang Basin of southwest Sulawesi. They are composed predominantly of packstones and wackestones, but grainstones and boundstones also occur. Uplift and exposure of the reef occurred during deposition. This, together with burial, resulted in dissolution of bioclasts, precipitation of meniscus and blocky spar cements, extensive fissuring of the rock and filling of the fissures by internal sediment, predominantly carbonate silts. The meniscus cements are unusual in that they occur mostly within biomouldic pores, particularly after corals. The meniscus form of the cement may be a result of air bubbles trapped within the complex pore-system formed from the dissolution of corals. The fissures, which are probably a product of fracturing associated with local fault movements, form complex networks linking biomouldic pores. Carbonate internal sediments, mostly crystal silt but also pelleted, which form thin graded layers in places, completely fill the fissures and adjacent biomouldic pores. These features, in association with bioclasts dissolution and meniscus cements, suggest a vadose origin. This interpretation is supported by the variation in the ɛ 180 and ɛ 130 stable isotope values of the internal sediment compared with the depositional matrix. Equant sparry calcite cements are locally extensive. On the basis of only moderately depleted ɛ 80 values and elevated strontium values they are tentatively interpreted to be of marine phreatic origin.

  16. Radon in the creswell crags Permian limestone caves.

    PubMed

    Gillmore, G K; Phillips, P S; Denman, A R; Gilbertson, D D

    2002-01-01

    An investigation of radon levels in the caves of Creswell Crags, Derbyshire, an important Site of Special Scientific Interest (SSSI) shows that the Lower Magnesian Limestone (Permian) caves have moderate to raised radon gas levels (27-7800 Bq m(-3)) which generally increase with increasing distance into the caves from the entrance regions. This feature is partly explained in terms of cave ventilation and topography. While these levels are generally below the Action Level in the workplace (400 Bq m(-3) in the UK), they are above the Action Level for domestic properties (200 Bq m(-3)). Creswell Crags has approximately 40,000 visitors per year and therefore a quantification of effective dose is important for both visitors and guides to the Robin Hood show cave. Due to short exposure times the dose received by visitors is low (0.0016 mSv/visit) and regulations concerning exposure are not contravened. Similarly, the dose received by guides is fairly low (0.4 mSv/annum) due in part to current working practice. However, the risk to researchers entering the more inaccessible areas of the cave system is higher (0.06 mSv/visit). This survey also investigated the effect of seasonal variations on recorded radon concentration. From this work summer to winter ratios of between 1.1 and 9.51 were determined for different locations within the largest cave system.

  17. Factors affecting floral herbivory in a limestone grassland

    NASA Astrophysics Data System (ADS)

    Breadmore, Karen N.; Kirk, William D. J.

    1998-12-01

    The amount of herbivore damage to the petals of 41 species of herbaceous plant was surveyed from April to September in a limestone grassland in central England. Damage was recorded as the percentage of the petal area removed. Most damage was caused by invertebrates, particularly slugs. The amount of invertebrate damage differed significantly between plant species and with time of year. The mean damage across all species was only 2 %, ranging from an average of 0 % in Galium sterneri to 8 % in Primula vulgaris. In most species, less than a quarter of flowers received any damage, so those that were damaged were often severely affected. Species flowering early or late in the season received more damage, possibly because of greater slug activity. Hypotheses to explain the inter-specific variation in the amount of herbivory were examined by testing for correlations with a range of plant variables. No correlations with flower-stem length, flower-stem thickness or the longevity of flowers were apparent. The amount of petal damage correlated strongly with flower size and petal thickness. This appeared to result from the prevalence of large-flowered species early and late in the season rather than from a preference for flower size and petal thickness per se. The evolutionary significance of floral herbivory is discussed.

  18. Transport studies of radon in limestone underlying houses

    SciTech Connect

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; Saultz, R.J.

    1990-01-01

    In hilly limestone terrains of the southern Appalachians, subterranean networks of solution cavities and fissures present circulatory systems facilitating convective and advective transport of radon-bearing gas. Evidence suggests that the primary driving forces for transport are aerostatic pressure differentials created by the difference between the underground and the outside air temperatures. Examples are presented of houses experiencing elevated indoor radon levels as a consequence of communicating with such subsurface transportation systems. The location of a house near the upper or lower end of a subterranean-circulatory system seems to produce amplification of indoor radon levels in winter or summer, respectively. The transport mechanism for radon-bearing air in karst and its impact on indoor radon need better understanding, both in regard to evaluating the geographical prevalence of the phenomenon and the induced spatial and temporal effects that are possible. This paper reports field studies made at houses in karst regions at Oak Ridge, Tennessee, and Huntsville, Alabama. A primary radon-transport mechanism is advocated of ascending or descending subsurface columns of air whose flows are largely driven by aerostatic pressure gradients created by the inground-outdoor air temperature differentials. 5 refs., 5 figs., 1 tab.

  19. Colour changes by laser irradiation of reddish building limestones

    NASA Astrophysics Data System (ADS)

    Grossi, C. M.; Benavente, D.

    2016-10-01

    We have used X-ray photoelectron spectroscopy (XPS) as a novel method to investigate the causes of colour changes in a reddish limestone under irradiation by a Q-switched Nd:YAG 1064 nm laser. We irradiated clean dry and wet surfaces of Pidramuelle Roja, a building stone frequently used in the Asturian heritage, at fluences ranging from 0.12 to 1.47 J cm-2. We measured the colour coordinates and undertook XPS analysis of the state of oxidation of iron both before and after irradiation. Visible colour changes and potential aesthetic damage occurred on dry surfaces from a fluence of 0.31 J cm-2, with the stone showing a greening effect and very intense darkening. The colour change on dry surfaces was considerably higher than on wet surfaces, which at the highest fluence (1.47 J cm-2) was also above the human visual detection threshold. The use of XPS demonstrated that the change in colour (chroma and hue) is associated with a reduction in the iron oxidation state on dry surfaces during laser irradiation. This points out to a potential routinary use of XPS to analyse causes of colour changes during laser cleaning in other types of coloured building stones.

  20. The Surface of a Limestone-Rich World?

    NASA Astrophysics Data System (ADS)

    Melis, Carl; Dufour, Patrick

    2016-06-01

    We present spectroscopic observations of the dust- and gas-enshrouded, polluted white dwarf star SDSSJ104341.53+085558.2 (hereafter SDSSJ1043). Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet spectra combined with deep Keck HIRES optical spectroscopy reveal the elements C, O, Mg, Al, Si, P, S, Ca, Fe, and Ni and enable useful limits for Sc, Ti, V, Cr, and Mn in the photosphere of SDSSJ1043. From this suite of elements we determine that the parent body being accreted by SDSSJ1043 is dry, rocky, and iron-poor. Synthesizing all available heavily-polluted white dwarf measurements, we find a trend in the Fe/Mg vs Fe/Si abundance ratio-space suggestive of whether accreted material originates from the inner or outer regions of a rocky body; we use this trend to identify the material being accreted by SDSSJ1043 as likely to have come from the outermost layers of a differentiated object. Enhanced levels of Ca and C in this object can be explained by the presence of significant amounts of calcium-carbonate and, if definitive, could be suggestive of a world with a crust rich in limestone.

  1. Multispectral analysis of limestone, dolomite, and granite, Mill Creek, Oklahoma

    NASA Technical Reports Server (NTRS)

    Rowan, L. C.; Watson, K.

    1970-01-01

    Spectral reflectance and thermal emission data were collected at the Mill Creek, Oklahoma test site during NASA missions 132 and 133 in June 1970. The data were collected by three aircraft flown several times during the diurnal cycle at altitudes of 150 to 17,000 m above mean terrain. Reflectance of the main rock types (limestone, dolomite, and granite) was determined from the data collected using a 12-channel multispectral scanner during mission 133 and from thermal infrared images recorded during mission 132 on an RS-7 scanner from 17,000 m above terrain. A preliminary rock recognition map was generated automatically using data collected from 900 m above terrain. The discrimination provided by the map is reasonably accurate. Misidentification occurred in areas of unusually high dolomite reflectivity. High altitude thermal infrared (10 to 12 micrometers) images show regional folds and faults distinguished by the presence of thermally contrasting materials. Linear and curvilinear structural features two to three times smaller than the nominal 17 m resolution could be detected.

  2. Microtaphofacies of Lower Jurassic Limestones from the Rotzo Formation, Northern Italy

    NASA Astrophysics Data System (ADS)

    Hoffmann, Luise; Nebelsick, James; Bassi, Davide; Posenato, Renato

    2015-04-01

    Microtaphofacies investigations allow for the study of taphonomic features of cemented limestones as found in thin sections. It allows for changes in environmental parameters to be assessed especially with respect to abrasion, fragmentation, encrustation and bioerosion of biotic components. Variations of taphonomic features along environmental gradients can thus be examined and can be compared to other facies determining features such as the distribution of specific biotic components as well as carbonate fabrics. The Lower Jurassic Rotzo Formation, occurring in the palaeogeographic unit Trento Platform (Southern Alps, Italy), is characterized by very well preserved components in a shallow water lagoonal setting. Components are dominated by dasycladalean algae, small and large benthic foraminifera, various bivalves, gastropods, brachiopods and echinoderms. Oncoids and trace fossils can also be prevalent. Although bioclastic components are commonly preserved in very fine micritic limestones, various types of mass occurrences are also present especially with respect to the bivalves including the well known Lithiotis fauna. Microfacies are dominated by mudstones. Bioclastic rich microfacies are also present with packstones and rudstones mainly containing foraminifera and bivalves, but also including, and in part dominated by other components. Microtaphofacies were studied along the Monte Toraro section to the east of Tonezza del Cimone (Vicenza Province). Abrasion, fragmentation, bioerosion and encrustation were qualitatively and semi-quantitatively analyzed with features being scored into three categories equivalent to good, fair, and poor preservation. This allowed for changes along the section to be analyzed. Abrasion and fragmentation are common in all facies and affect most components. Encrustation and bioerosion rates, however, are highly variably are only dominate in oncoids rich facies. Components in mass shell accumulations are often very well preserved

  3. Children's Play and Television.

    ERIC Educational Resources Information Center

    Powell, Mark

    2001-01-01

    Discusses adverse effects of FCC deregulation of children's television programming on children's play behavior. Discusses the difference between play and imitation, the role of high quality dramatic play in healthy child development, the popularity of war play, and use of toys to increase dramatic play. Considers ways to help children gain control…

  4. Children's Play and Television.

    ERIC Educational Resources Information Center

    Powell, Mark

    2001-01-01

    Discusses adverse effects of FCC deregulation of children's television programming on children's play behavior. Discusses the difference between play and imitation, the role of high quality dramatic play in healthy child development, the popularity of war play, and use of toys to increase dramatic play. Considers ways to help children gain control…

  5. The Denial of Play.

    ERIC Educational Resources Information Center

    Sutton-Smith, Brian

    Well meaning parents and teachers often use children's play for the purposes of literacy and socialization. Yet, these attempts may deny play to children by subordinating play to some other concept. Evidence shows that even when parents play with their very young children they generally play games like shopping, cooking, and eating; whereas when…

  6. The Denial of Play.

    ERIC Educational Resources Information Center

    Sutton-Smith, Brian

    Well meaning parents and teachers often use children's play for the purposes of literacy and socialization. Yet, these attempts may deny play to children by subordinating play to some other concept. Evidence shows that even when parents play with their very young children they generally play games like shopping, cooking, and eating; whereas when…

  7. Building Curriculum during Block Play

    ERIC Educational Resources Information Center

    Andrews, Nicole

    2015-01-01

    Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

  8. Children's Gendered Drawings of Play Behaviours

    ERIC Educational Resources Information Center

    Akseer, Tabasum; Lao, Mary Grace; Bosacki, Sandra

    2012-01-01

    According to child psychologists, vital links exist between children's drawings and their emotional, social, and cognitive development. Previous research has explored the important relations between drawings and play in educational settings. Given the vast research that explores the ambiguous topic of children's play, according to Richer (1990),…

  9. Children's Gendered Drawings of Play Behaviours

    ERIC Educational Resources Information Center

    Akseer, Tabasum; Lao, Mary Grace; Bosacki, Sandra

    2012-01-01

    According to child psychologists, vital links exist between children's drawings and their emotional, social, and cognitive development. Previous research has explored the important relations between drawings and play in educational settings. Given the vast research that explores the ambiguous topic of children's play, according to Richer (1990),…

  10. Primary deforestation and regrowth on limestone slopes on Vancouver Island, British Columbia

    SciTech Connect

    Harding, K.A.; Ford, D.C. . Dept. of Geography)

    1992-01-01

    Limestones, well bedded and steeply dipping, are common in northern Vancouver Island. They have been glaciated and host a high density of postglacial karren (dissolution pits, grooves and troughs linked to underlying caves). There is rich, mature forest cover of western hemlock, silver fir and red cedar that is rooted in the karren or in overlying glacial deposits. Logging commenced around 1900 AD, intensifying after 1960 with clear cutting and (often) burning of slash. Impacts were investigated quantitatively by comparing sixteen limestone sites with eight on adjoining volcanic rocks. Some sites on each retained original forest, other were cleared. It was found that soil losses following logging are significantly greater on the limestones because of wash into karren (the epikarst zone). Regrowth is retarded on the limestones also; one site cleared in 1911 had regained approximately 17% of its original volume of timber 75 years later.

  11. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States

    SciTech Connect

    Youngdahl, C.A.

    1987-08-01

    Weight losses of marble and limestone samples exposed to outdoor environments at field sites in the eastern United States have been monitored in studies initiated in 1984. The prodcedures are described, and the results are tabulated and discussed. A rate of marble loss approximately equivalent to 16 ..mu..m of surface recession per year was found in North Carolina, and losses of this order were also observed in New Jersey, New York, and Washington, DC. Limestone weight losses were much higher than for marble in the first year; loss of extraneous materials from the porous limestone appeared to be a likely contributor to the overall loss. The rate of limestone loss diminished in the second year, though it continued to be higher than for marble. Exposures are continuing in a planned 10-yr program of tests. 8 refs., 3 figs., 5 tabs.

  12. Neutron radiography and X-ray computed tomography for quantifying weathering and water uptake processes inside porous limestone used as building material

    SciTech Connect

    Dewanckele, J.; De Kock, T.; Fronteau, G.; Derluyn, H.; Vontobel, P.; Dierick, M.; Van Hoorebeke, L.; Jacobs, P.; Cnudde, V.

    2014-02-15

    Euville and Savonnières limestones were weathered by acid test and this resulted in the formation of a gypsum crust. In order to characterize the crystallization pattern and the evolution of the pore structure below the crust, a combination of high resolution X-ray computed tomography and SEM–EDS was used. A time lapse sequence of the changing pore structure in both stones was obtained and afterwards quantified by using image analysis. The difference in weathering of both stones by the same process could be explained by the underlying microstructure and texture. Because water and moisture play a crucial role in the weathering processes, water uptake in weathered and non-weathered samples was characterized based on neutron radiography. In this way the water uptake was both visualized and quantified in function of the height of the sample and in function of time. In general, the formation of a gypsum crust on limestone slows down the initial water uptake in the materials. - Highlights: • Time lapse sequence in 3D of changing pore structures inside limestone • A combination of X-ray CT, SEM and neutron radiography was used. • Quantification of water content in function of time, height and weathering • Characterization of weathering processes due to gypsum crystallization.

  13. Size and performance of anoxic limestone drains to neutralize acdic mine drainagei

    USGS Publications Warehouse

    Cravotta, C.A.

    2003-01-01

    Acidic mine drainage (AMD) can be neutralized effectively in underground, anoxic limestone drains (ALDs). Owing to reaction between the AMD and limestone (CaCO3), the pH and concentrations of alkalinity and calcium increase asymptotically with detention time in the ALD, while concentrations of sulfate, ferrous iron, and manganese typically are unaffected. This paper introduces a method to predict the alkalinity produced within an ALD and to estimate the mass of limestone required for its construction on the basis of data from short-term, closed-container (cubitainer) tests. The cubitainer tests, which used an initial mass of 4 kg crushed limestone completely inundated with 2.8 L AMD, were conducted for 11 to 16 d and provided estimates for the initial and maximum alkalinities and corresponding rates of alkalinity production and limestone dissolution. Long-term (5-11 yr) data for alkalinity and CaCO3 flux at the Howe Bridge, Morrison, and Buck Mountain ALDs in Pennsylvania, USA, indicate that rates of alkalinity production and limestone dissolution under field conditions were comparable with those in cubitainers filled with limestone and AMD from each site. The alkalinity of effluent and intermediate samples along the flow path through the ALDs and long-term trends in the residual mass of limestone and the effluent alkalinity were estimated as a function of the computed detention time within the ALD and second-order dissolution rate models for cubitainer tests. Thus, cubitainer tests can be a useful tool for designing ALDs and predicting their performance.

  14. A primary magnetization fingerprint from the Cretaceous Laytonville Limestone: Further evidence for rapid oceanic plate velocities

    NASA Astrophysics Data System (ADS)

    Tarduno, John A.; Myers, Michael

    1994-11-01

    Paleomagnetic data from the Cretaceous Laytonville Limestone of northern California are of geodynamic interest because they suggest a rate of absolute plate motion that exceeds those of all present-day plates. Such findings assume that a primary magnetization is preserved in these accreted pelagic limestone outcrops. This assumption is supported by a trend in the paleomagnetic inclination data that matches, in magnitude and sign, the expected sense of motion predicted by comparing the mean paleolatitude value with the North American apparent polar wander path. The pervasiveness of remagnetizations seen in shallow water carbonates of North America and elsewhere, however, raises questions as to whether the Laytonville Limestone is remagnetized, regardless of tests indicating a primary magnetization. The Laytonville Limestone falls in two categories. On the basis of unblocking temperature spectra, resistance to alternating field demagnetization and behavior during the acquisition of isothermal remanent magnetization, red Laytonville Limestone is thought to contain pigmentary hematite in addition to magnetite. Hysteresis curves from red Laytonville Limestone are wasp waisted, but because such curves also typify magnetite-hematite mixtures, these data do not provide an unambiguous test for remagnetization. Some white Laytonville Limestone, however, appears to contain negligible amounts of hematite and can be directly compared with the remagnetized carbonates. The lack of a remagnetization fingerprint in these white samples, together with paleomagnetic, lithologic, and paleontologic data, form a consistent data set supporting the primary nature of the Laytonville Limestone magnetization and rapid oceanic plate velocities. A small plate size coupled with the unusually vigorous mantle plume volcanism of the Cretaceous Pacific basin could have combined to reduce the effectiveness of asthenospheric drag, accounting for the rapid motion.

  15. Size and performance of anoxic limestone drains to neutralize acidic mine drainage.

    PubMed

    Cravotta, Charles A

    2003-01-01

    Acidic mine drainage (AMD) can be neutralized effectively in underground, anoxic limestone drains (ALDs). Owing to reaction between the AMD and limestone (CaCO3), the pH and concentrations of alkalinity and calcium increase asymptotically with detention time in the ALD, while concentrations of sulfate, ferrous iron, and manganese typically are unaffected. This paper introduces a method to predict the alkalinity produced within an ALD and to estimate the mass of limestone required for its construction on the basis of data from short-term, closed-container (cubitainer) tests. The cubitainer tests, which used an initial mass of 4 kg crushed limestone completely inundated with 2.8 L AMD, were conducted for 11 to 16 d and provided estimates for the initial and maximum alkalinities and corresponding rates of alkalinity production and limestone dissolution. Long-term (5-11 yr) data for alkalinity and CaCO3 flux at the Howe Bridge, Morrison, and Buck Mountain ALDs in Pennsylvania, USA, indicate that rates of alkalinity production and limestone dissolution under field conditions were comparable with those in cubitainers filled with limestone and AMD from each site. The alkalinity of effluent and intermediate samples along the flow path through the ALDs and long-term trends in the residual mass of limestone and the effluent alkalinity were estimated as a function of the computed detention time within the ALD and second-order dissolution rate models for cubitainer tests. Thus, cubitainer tests can be a useful tool for designing ALDs and predicting their performance.

  16. "The Woods Is a More Free Space for Children to Be Creative; Their Imagination Kind of Sparks out There": Exploring Young Children's Cognitive Play Opportunities in Natural, Manufactured and Mixed Outdoor Preschool Zones

    ERIC Educational Resources Information Center

    Zamani, Zahra

    2016-01-01

    Outdoor preschools are critical for children's play and development. Integrating observational and interview methods, this study examined four-to-five-year-old children's cognitive play experiences in an outdoor preschool with natural, mixed and manufactured zones. The observational results indicated that the natural and mixed zones offered a…

  17. "The Woods Is a More Free Space for Children to Be Creative; Their Imagination Kind of Sparks out There": Exploring Young Children's Cognitive Play Opportunities in Natural, Manufactured and Mixed Outdoor Preschool Zones

    ERIC Educational Resources Information Center

    Zamani, Zahra

    2016-01-01

    Outdoor preschools are critical for children's play and development. Integrating observational and interview methods, this study examined four-to-five-year-old children's cognitive play experiences in an outdoor preschool with natural, mixed and manufactured zones. The observational results indicated that the natural and mixed zones offered a…

  18. Accelerated weathering of limestone for CO2 mitigation opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, W.H.; Juan, C.A.S.; Rau, G.H.; Caldeira, K.

    2009-01-01

    Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO 2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO 2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

  19. Sedimentology and diagenesis of Miocene Lirio Limestone, Isla de Mona, Puerto Rico

    SciTech Connect

    Ruiz, H.; Gonzalez, L.A.; Budd, A.F. )

    1991-03-01

    Isla de Mona is a carbonate plateau, 50 mi west of Puerto Rico. The island lies on the southern portion of the Mona Platform. It is composed mostly of two Miocene carbonate units: Isla de Mona Dolomite overlain by Lirio Limestone. The Lirio Limestone was deposited on a sloping erosional surface over the Isla de Mona Dolomite. The Miocene Lirio Limestone consists mostly of backreef sands (packstones) with a reefal sequence (boundstones and grainstones) present in the southwestern portion of the island. The reefal sequence is made up mostly of Stylophora, Porites, and Millepora. Thin, discreet pockets of carbonate mud, rich in planktonic foraminifera and radiolarians and mixed with shallow benthic fauna/flora (foraminifera, echinoderms, red algae, and corals) interpreted as storm deposits, are found throughout the unit. An extensive reefal zone can be inferred to be present throughout the southwestern to southern portions of the Mona Platform. The Lirio Limestone is heavily karstified and is riddled with sinkholes on the plateau surfaces and caves around the periphery of the island. Caves are exposed around the periphery of the island, radiating from a depression in the central portions of the Lirio Limestone, near contacts with the Isla de Mona Dolomite, are partially dolomitized. The southwestern outcrops exhibit partial dolomitization throughout. The distribution of sinkholes, seaward caverns, and partial dolomitization of the lowermost Lirio Limestone suggests diagenetic modifications by meteoric fluids in central exposed portions of the island and by marine-meteoric fluids in the lowermost portions of the phreatic lens.

  20. Facies development of the Middle Miocene reefal limestone in northwest Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Al-kahtani, Khaled

    2017-04-01

    The Middle Miocene reefal limestone of Wadi Waqb Member (Jabal Kibrit Formation) in northwest Saudi Arabia is unconformably overlaying the Precambrian basement rocks and/or Early Miocene siliciclastics. On the basis of field observations, microfacies analyses and fossil content, particularly scleractinian corals, it composed of three depositional facies. These depositional facies are from base to top: 1) fore-reef facies, consists of hard, massive, marly coralline limestone with low diverse, small isolated corals heads, 2) reef-core facies, which consists of very hard, bioturbated coralline limestone with exclusively huge coral colonies of Porites and Tarbellastraea sp. and, 3) back reef facies, consists of sandy to pebbly massive, bioturbated limestone with very low diverse, scattered, small dendroid and massive heads of corals. The studied reefal limestone was deposited in fore-reef framework in an open marine environment with moderate to high energy conditions and changed upward to shallow marine facies with accumulation of skeletal grains by storms during regression. Key words: Facies development, Middle Miocene, Jabal Kibrit Formation, reefal limestone, Saudi Arabia.

  1. Direct sulfation of limestone based on oxy-fuel combustion technology

    SciTech Connect

    Chen, C.M.; Zhao, C.S.; Liu, S.T.; Wang, C.B.

    2009-10-15

    With limestone as the sorbent, the sulfation reaction can proceed via two different routes depending on whether calcination of the limestone takes place under the given reaction conditions. The direct sulfation reaction is defined as the sulfation reaction between sulfur dioxide (SO{sub 2}) and limestone in an uncalcined state. This reaction, based on oxyfuel combustion technology, was studied by thermogravimetric analysis. Surface morphologies of the limestone particles after sulfation were examined by a scanning electron microscope. Results show that there are more pores or gaps in the product layer formed by direct sulfation of limestone than by indirect sulfation, which can be attributed to the generation of carbon dioxide (CO{sub 2}) at a reaction interface. Compared with indirect sulfation, direct sulfation of limestone can yield much higher conversion and has a much higher reaction rate. For direct sulfation, the greater porosity in the product layer greatly reduces the solid-state ion diffusion distance, resulting in a higher reaction rate and higher conversion.

  2. Facies development of the Middle Miocene reefal limestone in northwest Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Al-Kahtany, Khaled M.

    2017-06-01

    The Middle Miocene reefal limestone of Wadi Waqb Member (Jabal Kibrit Formation) in northwest Saudi Arabia is unconformably overlaying the Precambrian basement rocks and/or Early Miocene siliciclastics. On the basis of field observations, microfacies analyses and fossil content, particularly scleractinian corals, the reefal limestone is composed of three depositional facies. These depositional facies are from base to top: 1) fore-reef facies, consists of hard, massive, marly coralline limestone with low diverse, small isolated corals heads, 2) reef-core facies, which consists of very hard, bioturbated coralline limestone with exclusively huge coral colonies of Porites and Tarbellastraea spp. and, 3) back reef facies, consists of sandy to pebbly massive, bioturbated limestone with very low diverse, scattered, small dendroid and massive heads of corals. The studied reefal limestone was deposited in fore-reef framework in an open marine environment with moderate to high energy conditions and changed upward to shallow marine facies with accumulation of skeletal grains by storms during regression.

  3. Influence of limestone characteristics on mercury re-emission in WFGD systems.

    PubMed

    Ochoa-González, Raquel; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

    2013-03-19

    This work evaluates the influence of the effect of the properties of limestones on their reactivity and the re-emission of mercury under typical wet scrubber conditions. The influence of the composition, particle size, and porosity of limestones on their reactivity and the effect of sorbent concentration, pH, redox potential, and the sulphite and iron content of the slurry on Hg(0) re-emission was assessed. A small particle size, a high porosity and a low magnesium content increased the high reactivity of the limestones. Moreover, it was found that the higher the reactivity of the sample the greater the amount of mercury captured in the scrubber. Although sulphite ions did not cause the re-emission of mercury from the suspensions of the gypsums, the limestones enriched in iron increased Hg(0) re-emission under low oxygen conditions. It was observed that the low pH values of the gypsum suspensions favored the cocapture of mercury because Fe(2+) formation was avoided. The partitioning of the mercury in the byproducts of the scrubber depended on the impurities of the limestones rather than on their particle size. No leaching of mercury from the gypsum samples occurred suggesting that mercury was either tightly bound to the impurities of the limestone or was transformed into insoluble mercury species.

  4. Interpretation of well hydrographs in the karstic Maynardville Limestone at the Oak Ridge Y-12 Plant

    SciTech Connect

    Shevenell, L.A.; McMaster, B.W.

    1996-06-01

    The Maynardville Limestone in Oak Ridge, Tennessee underlies the southern portion of Bear Creek Valley (BCV), and is considered to be the primary pathway for groundwater leaving the Y-12 Plant boundaries. Sixty-seven percent of all wells drilled into the Maynardville Limestone have intersected at least one cavity, suggesting karst features may be encountered throughout the shallow (< 200 ft) portions of the Limestone. Because waste facilities at the Y-12 Plant are located adjacent to the Maynardville Limestone, contaminants could enter the karst aquifer and be transported in the conduit system. As part of an overall hydrologic characterization effort of this karst aquifer, 41 wells in the Maynardville Limestone were instrumented with pressure transducers to monitor water level changes (hydrographs) associated with rain events. Wells at depths between approximately 20 and 750 ft were monitored over the course of at least two storms in order that variations with depth could be identified. The wells selected were not exclusively completed in cavities but were selected to include the broad range of hydrologic conditions present in the Maynardville Limestone. Cavities, fractures and diffuse flow zones were measured at a variety of depths. The water level data from the storms are used to identify areas of quickflow versus slower flowing water zones. The data are also used to estimate specific yields and continuum transmissitives in different portions of the aquifer.

  5. Mangrove plantation over a limestone reef - Good for the ecology?

    NASA Astrophysics Data System (ADS)

    Asaeda, Takashi; Barnuevo, Abner; Sanjaya, Kelum; Fortes, Miguel D.; Kanesaka, Yoshikazu; Wolanski, Eric

    2016-05-01

    There have been efforts to restore degraded tropical and subtropical mangrove forests. While there have been many failures, there have been some successes but these were seldom evaluated to test to what level the created mangrove wetlands reproduce the characteristics of the natural ecosystem and thus what ecosystem services they can deliver. We provide such a detailed assessment for the case of Olango and Banacon Islands in the Philippines where the forest was created over a limestone reef where mangroves did not exist in one island but they covered most of the other island before deforestation in the 1940s and 1950s. The created forest appears to have reached a steady state after 60 years. As is typical of mangrove rehabilitation efforts worldwide, planting was limited to a single Rhizophora species. While a forest has been created, it does not mimic a natural forest. There is a large difference between the natural and planted forests in terms of forest structure and species diversity, and tree density. The high density of planted trees excludes importing other species from nearby natural forests; therefore the planted forest remains mono-specific even after several decades and shows no sign of mimicking the characteristics of a natural forest. The planted forests provided mangrove propagules that invaded nearby natural forests. The planted forest has also changed the substratum from sandy to muddy. The outline of the crown of the planted forest has become smooth and horizontal, contrary to that of a natural forest, and this changes the local landscape. Thus we recommend that future mangrove restoration schemes should modify their methodology in order to plant several species, maintain sufficient space between trees for growth, include the naturally dominant species, and create tidal creeks, in order to reproduce in the rehabilitated areas some of the key ecosystem characteristics of natural mangrove forests.

  6. Techniques to improve the economics of limestone FGDS

    SciTech Connect

    Bresowar, G.E.; Klingspor, J.

    1995-12-31

    Many utilities have evaluated the cost of scrubbing versus fuel switching in various plans and scenarios to determine the most economical means for meeting the requirements of the new law. Presently, the future cost of removing a ton of SO{sub 2} is based on fuel switching, and the market values are in the range of $150 - $250 per ton. The perceived cost of FGDS retrofits is $250 - $400 per ton for eastern medium to high sulfur coal. ABB has studied the overall costs of FGDS and has developed a series of cost reducing improvements. and innovations. The improvements are manifested in ABBs new limestone FGDS technology known by the code phrase {open_quote}Stealth FGDS{close_quotes}. Stealth promises low capital and operating cost, high removal efficiencies for SO{sub 2} and other pollutants, little or positive environmental and economic impact on the local community, salable or non-hazardous by-products, ease of retrofit, and exceptionally short installation schedules. The concepts are being demonstrated in one system at the Miles Generating Station of Ohio Edison Company. Bearing the name {open_quote}LS-2 Advanced SO, Scrubbing{close_quotes}, the Stealth scrubber at Niles is a 110 MWe turnkey, retrofit unit to be completed 20 months after the release of engineering. It will remove 20,000 or more tons per year of SO{sub 2} from the flue gases generated by both Unit 1 and Unit 2 boilers, producing wallboard-grade gypsum. Upon completion of a four month test program, the plant will be operated by Ohio Edison for a four to five year reliability demonstration period. The performance and economic projections for LS-2 scrubbers show the technology to be quite attractive relative to projections for fuel switching when installed in a manner similar to the installation plan for Niles. The description and basis for these economic projections are described in this paper.

  7. Children in Play, Story, and School.

    ERIC Educational Resources Information Center

    Goncu, Artin, Ed.; Klein, Elisa L.

    In honor of the contributions of Greta G. Fein to the fields of developmental psychology and early childhood education, a community of scholars prepared this volume to explore how social play arises, social play's developmental and educational significance, and the ways in which social play can be promoted in early childhood settings. In addition,…

  8. Children in Play, Story, and School.

    ERIC Educational Resources Information Center

    Goncu, Artin, Ed.; Klein, Elisa L.

    In honor of the contributions of Greta G. Fein to the fields of developmental psychology and early childhood education, a community of scholars prepared this volume to explore how social play arises, social play's developmental and educational significance, and the ways in which social play can be promoted in early childhood settings. In addition,…

  9. Play at the Art Table: A Study of Children's Play Behaviors while Drawing.

    ERIC Educational Resources Information Center

    Escobedo, Theresa H.

    This descriptive study examined children's drawings and related language episodes to differentiate drawings exhibiting play from those exhibiting exploratory behavior. Drawings categorized as play were further analyzed to identify constructive and imaginary play. The play theory used as the basis of the study proposes that exploration and…

  10. Understanding Playful Pedagogies, Play Narratives and Play Spaces

    ERIC Educational Resources Information Center

    Goouch, Kathy

    2008-01-01

    This paper is a tentative attempt to unwrap and understand one aspect of playful practice and the influences which determine its existence in early years settings. "Storying" events, those occasions when teachers and children together "make up" stories or parts of stories, develop roles or co-construct fantasies, occur moment by moment in some…

  11. Children's Empowerment in Play

    ERIC Educational Resources Information Center

    Canning, Natalie

    2007-01-01

    This article examines the level of empowerment and autonomy children can create in their play experiences. It examines the play discourses that children build and maintain and considers the importance of play contexts in supporting children's emotional and social development. These aspects of play are often unseen or misunderstood by the adult…

  12. The Play of Psychotherapy

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2012-01-01

    The author reviews the role of play within psychotherapy. She does not discuss the formal play therapy especially popular for young children, nor play from the Jungian perspective that encourages the use of the sand tray with adults. Instead, she focuses on the informal use of play during psychotherapy as it is orchestrated intuitively. Because…

  13. Two people playing together: some thoughts on play, playing, and playfulness in psychoanalytic work.

    PubMed

    Vliegen, Nicole

    2009-01-01

    Children's play and the playfulness of adolescents and adults are important indicators of personal growth and development. When a child is not able to play, or an adolescent/adult is not able to be playful with thoughts and ideas, psychotherapy can help to find a more playful and creative stance. Elaborating Winnicott's (1968, p. 591) statement that "psychotherapy has to do with two people playing together," three perspectives on play in psychotherapy are discussed. In the first point of view, the child gets in touch with and can work through aspects of his or her inner world, while playing in the presence of the therapist. The power of play is then rooted in the playful communication with the self In a second perspective, in play the child is communicating aspects of his or her inner world to the therapist as a significant other. In a third view, in "playing together" child and therapist are coconstructing new meanings. These three perspectives on play are valid at different moments of a therapy process or for different children, depending on the complex vicissitudes of the child's constitution, life experiences, development, and psychic structure. Concerning these three perspectives, a parallel can be drawn between the therapist's attitude toward the child's play and the way the therapist responds to the verbal play of an adolescent or adult. We illustrate this with the case of Jacob, a late adolescent hardly able to play with ideas.

  14. Comparative study of porous limestones used in heritage structures in Cyprus and in Hungary

    NASA Astrophysics Data System (ADS)

    Theodoridou, Magdalini; Ioannou, Ioannis; Rozgonyi-Boissinot, Nikoletta; Török, Ákos

    2015-04-01

    Porous limestone is widely used as construction material in the monuments of Cyprus and Hungary. The present study compares the physical properties of a bioclastic limestone from Cyprus and an oolitic limestone from Hungary. Petra Gerolakkou is a Pliocene limestone from Cyprus that originates from the district of Nicosia, the island's capital. It has been extensively used throughout the years in construction and restoration projects, particularly in the Nicosia area. Distinctive examples of its use can be found in the majority of the most important historic monuments in Nicosia, such as the Venetian walls and fortifications, churches (e.g. the Agia Sofia Cathedral), the archbishop and presidential palaces and a high number of other traditional buildings. The studied Miocene limestone from Hungary was exploited from Sóskút quarry (15-20 km W-SW to Budapest). The quarry provided stone for emblematic monuments of the capital of Hungary such as the Parliament building, Mathias Church, the Opera House and Citadella. In this study, mechanical parameters for both aforementioned stones, such as uniaxial compressive and tensile strengths, were tested under laboratory conditions. Their density, porosity and water absorption were also compared. The studied limestone from Cyprus exhibits porosity values within the range of 48-51%, apparent density between 1340 and 1400 kg/m3 and strength values under uniaxial compressive load between 1.2 and 2.8 MPa. This lithotype is also considered susceptible to salt decay, since an approximate mass loss of 12.5% is noted after 15 salt crystallization artificial weathering cycles. The porosity of the Hungarian limestone is in the order of 16-35%, the bulk density is 1600-1950 kg/m3, while the compressive strength is 2.5-15 MPa. Durability tests indicate that even after 10 freeze-thaw cycles the loss in strength is dramatic. Test results indicate that use of porous limestone in both countries is common and fabric strongly controls the

  15. Nomination of the Globigerina Limestone of the Maltese Islands as a "Global Heritage Stone Resource"

    NASA Astrophysics Data System (ADS)

    Cassar, JoAnn

    2016-04-01

    The Maltese Islands consist of two main islands, Malta and Gozo, as well as a small number of islets, and lie in the central Mediterranean Sea approximately 90 km south of Sicily. Although only 316 square kilometres in size, the Islands contain a rich concentration of archaeological sites and historic buildings, as well as vernacular architecture and modern buildings, for the most part built of the local Globigerina Limestone, which is one of the few natural resources of the Islands. This stone can be described as a typical "soft limestone", very easy to carve and shape. It forms part of the large family of Oligo-Miocene "soft limestones" widely diffused in the Mediterranean Basin. The Maltese Globigerina Limestone Formation is one of five main Formations, and varies in thickness from 20 to over 200 m. The material used for building is located stratigraphically in the lower part of the Globigerina Limestone Formation, called the Lower Globigerina Limestone. This Formation is stratified into thick beds at outcrop. Sections where bioturbation is concentrated often also occur. This limestone is fine-grained, yellow to pale grey in colour, almost wholly composed of the tests of globigerinid planktonic foraminifera. Petrographically, Globigerina Limestone can be described as a bioclastic packstone, with bioclastic wackestones also occurring. This limestone has always been used as the predominant building material in the Islands. The Maltese prehistoric Temples, which were constructed approximately 6000 years ago, bear testimony to this. Between 1530 and 1798 the Order of the Knights of St John built kilometres of fortifications in this same material to protect the Island from the expanding Ottoman Empire. Fortifications, impressive churches, auberges and palaces were built of this stone during this period. The capital city of Valletta, a rich and dense manifestation of Baroque architecture in Globigerina Limestone, is included on the UNESCO World Heritage List, as are

  16. Cohesive model applied to fracture propagation in Indiana Limestone

    NASA Astrophysics Data System (ADS)

    Dewers, T. A.; Rinehart, A. J.; Bishop, J. E.

    2014-12-01

    We apply a cohesive fracture (CF) model to results of short-rod (SR), notched 3-point-bend (N3PB) tests, and Brazil tests in Indiana Limestone. Calibration and validation of the model are performed within a commercial finite element modeling platform. By using a linear traction-displacement softening response for a defined fracture-opening displacement (w1) following peak tensile stress (σcrit), the CF model numerically lumps different spatially distributed inelastic processes occurring at and around fracture tips into a thin zone within an elastic domain. Both the SR and the N3PB test specimen geometries use a notch partway through the sample to control the location of fracture propagation. We develop a mesh for both the SR and N3PB geometries with a narrow cohesive zone in the center of notches. From the Brazil tests, we find a tensile splitting stress (σsplit) of 5.9 MPa. We use a σsplit as the peak tensile stress (σcrit) for all simulations. The Young's modulus (E) and the critical crack opening distance (w1) of the CF model are calibrated against the SR data. The model successfully captures the elastic, yield, peak, and initial and late failure behavior and compares favorably against the N3PB tests. Differences in force-displacement and crack propagation are primarily caused by: more mixed-mode (shear and opening) crack propagation in N3PB than in SR tests, causing a higher peak; and transition from compression (high E) to tension (low E) in a larger volume of the N3PB sample than in the SR geometry. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy

  17. Optimization of Trona/Limestone Injection for SO2 Control in Coal-Fired Boilers

    SciTech Connect

    2005-09-01

    Mobotec USA develops and markets air pollution control systems for utility boilers and other combustion systems. They have a particular interest in technologies that can reduce NOx, SOx, and mercury emissions from coal-fired boilers, and have been investigating the injection of sorbents such as limestone and trona into a boiler to reduce SOx and Hg emissions. WRI proposed to use the Combustion Test Facility (CTF) to enable Mobotec to conduct a thorough evaluation of limestone and trona injection for SO{sub 2} control. The overall goal of the project was to characterize the SO{sub 2} reductions resulting from the injection of limestone and trona into the CTF when fired with a high-sulfur eastern bituminous coal used in one of Mobotec's Midwest installations. Results revealed that when limestone was injected at Ca:S molar ratios of 1.5 to 3.0, the resulting SO{sub 2} reductions were 35-55%. It is believed that further reductions can be attained with improved mixing of the sorbent with the combustion gases. When limestone was added to the coal, at Ca:S molar ratios of 0.5 to 1.5, the SO{sub 2} reductions were 13-21%. The lower reductions were attributed to dead-burning of the sorbent in the high temperature flame zone. In cases where limestone was both injected into the furnace and added to the coal, the total SO{sub 2} reductions for a given Ca:S molar ratio were similar to the reductions for furnace injection only. The injection of trona into the mid-furnace zone, for Na:S molar ratios of 1.4 to 2.4, resulted in SO{sub 2} reductions of 29-43%. Limestone injection did not produce any slag deposits on an ash deposition probe while trona injection resulted in noticeable slag deposition.

  18. Economic evaluation of limestone and lime flue-gas-desulfurization processes

    SciTech Connect

    Burnett, T.A.; Stephenson, C.D.; Sudhoff, F.A.; Veitch, J.D.

    1983-05-01

    The preliminary-grade economics (accuracy: -15%, +30%) of various alternative limestone scrubbing options (absorber type, with and without forced oxidation, and with and without adipic acid enhancemet) are examined using the current design and economic premises established for the continuing series of economic evaluations performed by TVA for EPA. The economics are projected using the Shawnee lime/limestone computer model, which is based on long-term operating data from the EPA Alkali Scrubbing Test Facility at the TVA Shawnee Steam Plant near Paducah, Kentucky. The capital investment for the base-case limestone scrubbing process (500 MW, 3.5% sulfur coal, 1979 NSPS, spray tower, forced oxidation, landfill) is $206/kW. The first-year and levelized annual revenue requirements are 10.59 and 15.09 mills/kWh, respectively. Costs for the equivalent limestone scrubbing process using a Turbulent Contact Absorber (TCA) are lower while those for the venturi - spray tower absorber are higher. The forced-oxidation landfill disposal option has a lower capital investment than the unoxidized pond disposal option for all cases studied; however, the first-year and levelized annual revenue requirements are slightly higher for the forced-oxidation landfill process for most coal applications. For the spray tower limestone process to achieve a specified SO/sub 2/ removal efficiency, it is more economical to increase the limestone stoichiometry and minimize the absorber L/G. The use of adipic acid or possibly dibasic acid (DBA) as an additive to enhance SO/sub 2/ removal in the limestone scrubbing process is an economically attractive option. The use of adipic acid remains economically attractive even if both a high unit cost and a high degradation factor for adipic acid are assumed. 176 references, 35 figures, 56 tables.

  19. Whole rolled sunflower seeds with or without additional limestone in lactating dairy cattle rations.

    PubMed

    Finn, A M; Clark, A K; Drackley, J K; Schingoethe, D J; Sahlu, T

    1985-04-01

    Thirty lactating Holstein cows were in a continuous trial from 21 to 120 days postpartum to evaluate diets containing whole, rolled sunflower seeds with or without additional limestone. Cows were fed individually total mixed rations of (dry matter) 47% corn silage, 9% alfalfa hay, and 44% concentrate. Concentrates were corn and soybean meal (control); corn, soybean meal, and 22% sunflower seeds; or corn, soybean meal, and sunflower seeds plus 3.5% additional limestone. Milk yield (32.2, 32.0, and 32.8 kg/day) was similar among rations. Yield of 4% fat-corrected milk was lower for cows fed sunflower seeds without additional limestone (30.2, 28.1, and 30.2 kg/day) because of lower milk fat percentages (3.57, 3.19, and 3.51). Milk protein percentage tended to be lower for cows fed sunflower seeds with additional limestone (3.01, 2.97, and 2.90). Milk, flavor score was acceptable but tended to be lower for milk from cows fed sunflower seeds with additional limestone (8.4, 8.5, and 7.9). Milk fat from cows fed sunflower seed rations contained less carbon-14:0, 16:0, and 16:1 fatty acids but more carbon-18:0. Dry matter intakes were 21.0, 18.4, and 20.0 kg/day. Dry matter digestibilities, body weight changes, and ruminal volatile fatty acid concentrations were similar among treatments. Total cholesterol in blood serum was elevated in cows fed sunflower seed rations. Insoluble salts of fatty acids were increased in ruminal fluid dry matter from cows fed sunflower seeds but were not increased further by additional limestone. Concentrations of nonesterified carbon-18:1 fatty acids in ruminal fluid dry matter were lower for cows fed sunflower seeds with additional limestone.

  20. Field and laboratory experiments on high dissolution rates of limestone in stream flow

    NASA Astrophysics Data System (ADS)

    Hattanji, Tsuyoshi; Ueda, Mariko; Song, Wonsuh; Ishii, Nobuyuki; Hayakawa, Yuichi S.; Takaya, Yasuhiko; Matsukura, Yukinori

    2014-01-01

    Field and laboratory experiments were performed to examine dissolution rates of limestone in stream flow. Field experiments were conducted in three stream sites (A-C) with different lithological or hydrological settings around a limestone plateau in the Abukuma Mts., Japan. Sites A and B are allogenic streams, which flow from non-limestone sources into dolines, and site C has a karst spring source. Tablets made of limestone from the same plateau with a diameter of 3.5 cm and a thickness of 1 cm were placed in the streams for 3 years (2008-2011) where alkalinity, pH and major cation concentrations were measured periodically. The saturation indices of calcite (SIc) of stream water were - 2.8 ± 0.4 at site A, - 2.5 ± 0.4 at site B and - 0.5 ± 0.4 at site C. Annual weight loss ratios for tablets were extremely high at site A (0.11-0.14 mg cm- 2 d- 1), high at site B (0.05 mg cm- 2 d- 1), and low at site C (0.005 mg cm- 2 d- 1). The contrasting rates of weight loss are mainly explained by chemical conditions of stream water. In addition, laboratory experiments for dissolution of limestone tablets using a flow-through apparatus revealed that flow conditions around the limestone tablet is another important factor for dissolution in the stream environment. These results revealed that limestone dissolves at a rapid rate where water unsaturated to calcite continuously flows, such as in an allogenic stream.

  1. New reef exploration targets in Fiji, Southwest Pacific

    SciTech Connect

    Rodd, J. )

    1994-03-07

    Fiji has two prospective shallow water Tertiary basins containing numerous reefal leads: Bligh Water basin, covering some 9,500 sq km, and Bau Waters basin having a shallow water area of about 1,600 sq km. Water is mostly 50--500 m deep and sediment as thick as 5 km. Source rocks outcrop on the main island of Viti Levu and have been drilled offshore, where they give rise to an oil seep. Over 20 new reefal leads have been identified on existing seismic data. Traps typically have estimated recoverable reserves of about 270 bbl of oil per structure. There is plenty of scope for additional traps in areas where seismic coverage is sparse and of poor quality. The government is actively encouraging oil companies to invest in exploration and reviewing the fiscal policy to offer more competitive terms. The paper describes the regional tectonic setting, Fiji geology, exploration history, prospective basins, source rocks, maturity, reef reservoirs, seals, reef play, limestone turbidite play, and legislation.

  2. Mineralogical characterization of the Shelburne Marble and the Salem limestone: Test stones used to study the effects of acid rain

    SciTech Connect

    McGee, E.S.

    1989-01-01

    The Salem Limestone and the Shelburne Marble are representative of limestones and marbles commonly used in buildings and monuments. Both stones are composed predominantly of calcite. The Salem Limestone is homogeneous in composition and mineralogic characteristics throughout the test block. The Shelburne Marble has compositionally homogeneous mineral phases, but the distribution of those phases within the test block is random. The mineralogy and physical characteristics of the Shelburne Marble and Salem Limestone test blocks described in the study provide a baseline for future studies of the weathering behavior of these stones. Because the Shelburne Marble and the Salem Limestone are representative of typical commercial marbles and limestones, they are likely to be useful in a consortium study of the effects of acid precipitation on these two types of building stones.

  3. Role-Playing Mitosis.

    ERIC Educational Resources Information Center

    Wyn, Mark A.; Stegink, Steven J.

    2000-01-01

    Introduces a role playing activity that actively engages students in the learning process of mitosis. Students play either chromosomes carrying information, or cells in the cell membrane. (Contains 11 references.) (Author/YDS)

  4. Role-Playing Mitosis.

    ERIC Educational Resources Information Center

    Wyn, Mark A.; Stegink, Steven J.

    2000-01-01

    Introduces a role playing activity that actively engages students in the learning process of mitosis. Students play either chromosomes carrying information, or cells in the cell membrane. (Contains 11 references.) (Author/YDS)

  5. Playing It Right

    ERIC Educational Resources Information Center

    Tooley, Kay

    1973-01-01

    Described is one technique, referred to as "playing it right," to aid the therapist in the treatment of borderline children. "Playing it right" is based on the introduction of reality rules into the fantasy world of the borderline child. (CS)

  6. Steam Cured Self-Consolidating Concrete and the Effects of Limestone Filler

    NASA Astrophysics Data System (ADS)

    Aqel, Mohammad A.

    The purpose of this thesis is to determine the effect and the mechanisms associated with replacing 15% of the cement by limestone filler on the mechanical properties and durability performance of self-consolidating concrete designed and cured for precast/prestressed applications. This study investigates the role of limestone filler on the hydration kinetics, mechanical properties (12 hours to 300 days), microstructural and durability performance (rapid chloride permeability, linear shrinkage, sulfate resistance, freeze-thaw resistance and salt scaling resistance) of various self-consolidating concrete mix designs containing 5% silica fume and steam cured at a maximum holding temperature of 55°C. This research also examines the resistance to delayed ettringite formation when the concrete is steam cured at 70°C and 82°C and its secondary consequences on the freeze-thaw resistance. The effect of several experimental variables related to the concrete mix design and also the curing conditions are examined, namely: limestone filler fineness, limestone filler content, cement type, steam curing duration and steam curing temperature. In general, the results reveal that self-consolidating concrete containing 15% limestone filler, steam cured at 55°C, 70°C and 82°C, exhibited similar or superior mechanical and transport properties as well as long term durability performance compared to similar concrete without limestone filler. When the concrete is steam cured at 55°C, the chemical reactivity of limestone filler has an important role in enhancing the mechanical properties at 16 hours (compared to the concrete without limestone filler) and compensating for the dilution effect at 28 days. Although, at 300 days, the expansion of all concrete mixes are below 0.05%, the corresponding freeze-thaw durability factors vary widely and are controlled by the steam curing temperature and the chemical composition of the cement. Overall, the material properties indicate that the use

  7. Limestones as a paleobathymeter for reconstructing past seismic activities: Muroto-misaki, Shikoku, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Iryu, Y.; Maemoku, H.; Yamada, T.; Maeda, Y.

    2009-03-01

    Muroto-misaki (Cape Muroto) is located at the southern tip of the eastern half of Shikoku, southwestern Japan and is ~ 100 km north of the Nankai Trough where the Philippine Sea Plate is being subducted beneath the Eurasian Plate. Therefore, the Muroto-misaki area has been seismically uplifted. Sedimentologic analyses were conducted on Holocene limestones that occur along the coast from Muroto-misaki to Meoto-iwa, located ~ 13 km north of the cape. The limestones are limited to less than 9.2 m in elevation. The limestones are up to 4.4 m in mean diameter, up to 0.5 m in thickness, and consist mainly of fossilized sessile organisms, including annelids, corals, bryozoans, encrusting foraminifers, barnacles, nongeniculate coralline algae, and, to a lesser extent, molluscs and peyssonneliacean algae. Acicular and equant cements are minor components. Acicular cements are found in semi-closed spaces between coralline algal crusts and their substrates. The modal composition of limestones was determined by a point-counting technique. Based on the biotic composition, the Holocene limestones can be classified into six types (Types I to VI). A comparison of the vertical distribution of these rock types with that of modern sessile organisms indicates that the top of Type I limestone, which is characterized by the occurrence of hermatypic corals, corresponds approximately to the mean low water springs when the limestones formed. A difference in the highest occurrence of Type I limestone between two sites may represent the variation in the total amount of uplift over the last 1000 to 1500 years, which resulted in an apparent northward decline of paleo-mean low water springs at a rate of ~ 10 cm/km. Therefore, the Holocene limestones are a good paleobathymeter to reconstruct past seismic activities in this area. This study shows that warm temperate carbonate deposits are as excellent recorders of geologic events, such as the timing and scale of repeated coseismic uplifts and

  8. The Significance of Podpe limestone in the Cultural Heritage of Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Bedjanič, Mojca; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Skaberne, Dragomir; Zupančič, Nina

    2013-04-01

    Podpeč limestone is characterized by its dark grey, or nearly black colour, with white fossil shells of the Lithiotis. These beds, which have been dated as Lower Jurassic, occur in southern and south-western Slovenia, and are particularly common in areas southwest of Ljubljana. The main quarry, which is not active, is located next to the village of Podpeč near Ljubljana, and has been declared as a geological natural value of national importance; as such, it is officially protected as a natural monument. In the close vicinity of the village there are some other smaller quarries, but all of them have been abandoned. With its very low porosity (0.9%) and water absorption (0.13 - 0.30 % by mass), but relatively high compressive strength (185 MPa), this limestone is quite durable, although its colouring becomes somewhat bleached when situated outdoors. The use of Podpeč limestone was first documented in the case of the Roman period in Slovenia, when it was used for funerary stelae, votive altars, boundary stones, and other artefacts. At the end of the 5th Century AD, with the fall of the Roman Empire, stone-cutting ceased at Podpeč for the next few centuries. Before 1850 Podpeč limestone had no special value. Only very few portals or pilasters made of this stone are known, and no evidence has been found in churches. However, towards the end of the 19th Century Podpeč limestone became better-known, although before the first half of the 20th Century there were no significant stonecutting workshops in Podpeč. After this, stone was supplied progressively from the main quarry. Large numbers of buildings in Ljubljana and central Slovenia have sills, lintels and jambs made of Podpeč limestone. Production stopped in 1967. The internationally renowned Slovenian architect Jože Plečnik (1872-1957) used Podpeč limestone in various Slovenian buildings - the central stadium in Ljubljana, the National University Library, many altars and churches (Bogojina, the Ši\\vska and

  9. Playful "Moments" in Psychotherapy

    ERIC Educational Resources Information Center

    Terr, Lenore C.; Deeney, John M.; Drell, Martin; Dodson, Jerry W.; Gaensbauer, Theodore J.; Massie, Henry; Minde, Klaus; Stewart, George; Teal, Stewart; Winters, Nancy C.

    2006-01-01

    This article demonstrates how taking the time out to play, commenting pungently on play, serving up surprise and adventure, and developing mutually understood codes or inside jokes help the psychiatrist to turn a child around. In this article, the authors categorized what principles of treatment their 10 vignettes about playfulness illustrated,…

  10. The Pedagogy of Play

    ERIC Educational Resources Information Center

    Giesbrecht, Sheila

    2012-01-01

    Play is important. Environmental educators Sobel and Louv write about the relationship between children and outside play and suggest that early transcendental experiences within nature allow children to develop empathetic orientations towards the natural world. Children who play out-of-doors develop an appreciation for the environment and…

  11. Life! Through Play.

    ERIC Educational Resources Information Center

    Van Anne, Nancy

    This speech presents a review of research concerning the nature of play. Some of the formal characteristics of play are: (a) it is distinct from ordinary life in its "temporariness" and its limitless location; (b) there is an element of tension in play that leads to uncertainty concerning the outcome but at the same time provides the opportunity…

  12. Playing against the Game

    ERIC Educational Resources Information Center

    Remmele, Bernd

    2017-01-01

    The paper first outlines a differentiation of play/game-motivations that include "negative" attitudes against the play/game itself like cheating or spoilsporting. This problem is of particular importance in concern of learning games because they are not "played" for themselves--at least in the first place--but due to an…

  13. The Importance of Play.

    ERIC Educational Resources Information Center

    Sher, Allen

    Play is the spontaneous or organized recreational activity of children; it is at the heart of the preschool curriculum. Play aids in the development of physical, intellectual, and social skills. Children's play progresses through three developmental stages: solitary, parallel, and social. Preschool teachers should arrange for four kinds of…

  14. Outdoor Creative Play Areas.

    ERIC Educational Resources Information Center

    Miller, Peggy L.

    Guidelines are given for the development of outdoor play areas on school sites to provide children with natural areas and simple facilities for creative play. Site selection, analysis, and development are discussed. Natural, topographical features of the environment and natural play equipment are suggested. Illustrations are also presented to aid…

  15. Play Is the Way

    ERIC Educational Resources Information Center

    Gross, Steve; Sanderson, Rebecca Cornelli

    2012-01-01

    Historically, play has been viewed as a frivolous break from important endeavors like working and learning when, in fact, a child's ability to fully and freely engage in play is essential to their learning, productivity, and overall development. A natural drive to play is universal across all young mammals. Children from every society on earth…

  16. The Pedagogy of Play

    ERIC Educational Resources Information Center

    Giesbrecht, Sheila

    2012-01-01

    Play is important. Environmental educators Sobel and Louv write about the relationship between children and outside play and suggest that early transcendental experiences within nature allow children to develop empathetic orientations towards the natural world. Children who play out-of-doors develop an appreciation for the environment and…

  17. Play Is the Way

    ERIC Educational Resources Information Center

    Gross, Steve; Sanderson, Rebecca Cornelli

    2012-01-01

    Historically, play has been viewed as a frivolous break from important endeavors like working and learning when, in fact, a child's ability to fully and freely engage in play is essential to their learning, productivity, and overall development. A natural drive to play is universal across all young mammals. Children from every society on earth…

  18. Playful Teaching Practices

    ERIC Educational Resources Information Center

    Michaelis, Bill

    2005-01-01

    In physical education, playful teaching practices are essential to relationship building and creating "connections" for successful group dynamics. Perhaps most importantly, playful teachers develop positive attitudes in their students and help students understand that learning can be fun and joyful. Playful teaching practices also greatly enhance…

  19. Capsule report: Adipic acid-enhanced lime/limestone test results at the EPA alkali scrubbing test facility

    SciTech Connect

    Burbank, D.A.; Wang, S.C.

    1982-04-01

    The fifth in a series of reports describing the results of the Shawnee Lime and Limestone Wet Scrubbing Test Program, the report describes the results of adipic acid-enhanced limestone wet scrubbing systems. A primary objective of the program was to enhance sulfur oxide removal and improve the reliability and economics of lime and limestone wet scrubbing systems by use of adipic acid as a chemical additive.

  20. Actinobacterial diversity in limestone deposit sites in Hundung, Manipur (India) and their antimicrobial activities

    PubMed Central

    Nimaichand, Salam; Devi, Asem Mipeshwaree; Tamreihao, K.; Ningthoujam, Debananda S.; Li, Wen-Jun

    2015-01-01

    Studies on actinobacterial diversity in limestone habitats are scarce. This paper reports profiling of actinobacteria isolated from Hundung limestone samples in Manipur, India using ARDRA as the molecular tool for preliminary classification. A total of 137 actinobacteria were clustered into 31 phylotypic groups based on the ARDRA pattern generated and representative of each group was subjected to 16S rRNA gene sequencing. Generic diversity of the limestone isolates consisted of Streptomyces (15 phylotypic groups), Micromonospora (4), Amycolatopsis (3), Arthrobacter (3), Kitasatospora (2), Janibacter (1), Nocardia (1), Pseudonocardia (1) and Rhodococcus (1). Considering the antimicrobial potential of these actinobacteria, 19 showed antimicrobial activities against at least one of the bacterial and candidal test pathogens, while 45 exhibit biocontrol activities against at least one of the rice fungal pathogens. Out of the 137 actinobacterial isolates, 118 were found to have at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, NRPS). The results indicate that 86% of the strains isolated from Hundung limestone deposit sites possessed biosynthetic gene clusters of which 40% exhibited antimicrobial activities. It can, therefore, be concluded that limestone habitat is a promising source for search of novel secondary metabolites. PMID:25999937

  1. Effect of magnesium salts on the sulphation capacity of limestone slurry

    SciTech Connect

    Ozyuguran, A.; Altun-Ciftcioglu, G.; Karatepe, N.; Ersoy-Mericboyu, A.

    2006-09-15

    The effect of different magnesium salts such as MgO, MgSO{sub 4}.7H{sub 2}O and Mg(OH){sub 2} on the total sulphation capacities of limestone slurries prepared from five different limestone samples was investigated. Sulphation reactions of slurries were conducted at a constant temperature of 323 K in a gaseous mixture consisting of 5% O{sub 2}, 10% CO{sub 2}, 0.5% SO{sub 2} and a balance of nitrogen by volume. It was found that the total sulphation capacities of limestone slurries increased with the addition of MgO and Mg(OH){sub 2} salts and decreased with the addition of MgSO{sub 4}.7H{sub 2}O salt. Depending on the chemical composition of the limestone samples the total sulphation capacities of limestone slurries were increased between 22.30% and 75.00% by MgO addition and between 23.70% and 69.00% by Mg(OH){sub 2} addition.

  2. Fluoride removal from groundwater by limestone treatment in presence of phosphoric acid.

    PubMed

    Gogoi, Sweety; Nath, Suresh K; Bordoloi, Shreemoyee; Dutta, Robin K

    2015-04-01

    Fluoride removal from groundwater has been studied by addition of dilute phosphoric acid (PA) to the influent water before limestone treatment through laboratory plug-flow column experiments and bench-scale plug-flow pilot tests. In this PA-enhanced limestone defluoridation (PAELD) technique, fluoride is removed from 0.526 mM to 0.50-52.60 μM in 3 h with near neutral final pH. The presence of PA increases the fluoride removal capacity of limestone to 1.10 mg/g compared to 0.39 mg/g reported in its absence. The changes in fluoride removal with variation in initial PA concentration, initial fluoride concentration and the final pH have been found to be statistically significant with p < 0.05. The estimated recurring cost is US$ ≈0.58/m(3) water. Simple scrubbing and rinsing is a preferable method for regeneration of limestone as it is almost equally effective with lime or NaOH. Sorption of fluoride by calcium phosphates produced in situ in the reactor is the dominant mechanism of fluoride removal in the PAELD. Precipitation of CaF2 and sorption of fluoride by the limestone also contribute to the fluoride removal. High efficiency, capacity, safety, environment-friendliness, low cost and simplicity of operation make the PAELD a potential technique for rural application.

  3. Forest seasonality shapes diet of limestone-living rhesus macaques at Nonggang, China.

    PubMed

    Tang, Chuangbin; Huang, Libin; Huang, Zhonghao; Krzton, Ali; Lu, Changhu; Zhou, Qihai

    2016-01-01

    Limestone forests are an unusual habitat for primates, but little information is available for the genus Macaca in such habitats, making a comparative understanding of extant limestone primates' behavioral adaptation incomplete. We collected data on the diet of rhesus macaques (Macaca mulatta) in a limestone habitat at Nonggang Nature Reserve, southwestern Guangxi, China, and examined the effects of forest seasonality on their diet. Our results indicated that a total of 114 species of plants are consumed by macaques. Young leaves are a preferred food, accounting for 48.9 and 56.9% of the overall diets. One group significantly increased young leaf consumption in response to availability. Fruits contributed to only 27.3 and 28.7% of overall diet. The macaque diet varied according to season. They fed on more fruits in the rainy season. Consumption of mature leaves increased when the availability of young leaves and fruits declined in the dry season, indicating that mature leaves are a fallback food for macaques in a limestone habitat. Similar to sympatric Assamese macaques, Bonia saxatilis, a shrubby, karst-endemic bamboo was consumed by rhesus macaques throughout the year, and was the top food species through most of the year, suggesting that bamboo consumption represents a key factor in the macaque's dietary adaptation to limestone habitat.

  4. Actinobacterial diversity in limestone deposit sites in Hundung, Manipur (India) and their antimicrobial activities.

    PubMed

    Nimaichand, Salam; Devi, Asem Mipeshwaree; Tamreihao, K; Ningthoujam, Debananda S; Li, Wen-Jun

    2015-01-01

    Studies on actinobacterial diversity in limestone habitats are scarce. This paper reports profiling of actinobacteria isolated from Hundung limestone samples in Manipur, India using ARDRA as the molecular tool for preliminary classification. A total of 137 actinobacteria were clustered into 31 phylotypic groups based on the ARDRA pattern generated and representative of each group was subjected to 16S rRNA gene sequencing. Generic diversity of the limestone isolates consisted of Streptomyces (15 phylotypic groups), Micromonospora (4), Amycolatopsis (3), Arthrobacter (3), Kitasatospora (2), Janibacter (1), Nocardia (1), Pseudonocardia (1) and Rhodococcus (1). Considering the antimicrobial potential of these actinobacteria, 19 showed antimicrobial activities against at least one of the bacterial and candidal test pathogens, while 45 exhibit biocontrol activities against at least one of the rice fungal pathogens. Out of the 137 actinobacterial isolates, 118 were found to have at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, NRPS). The results indicate that 86% of the strains isolated from Hundung limestone deposit sites possessed biosynthetic gene clusters of which 40% exhibited antimicrobial activities. It can, therefore, be concluded that limestone habitat is a promising source for search of novel secondary metabolites.

  5. Tidal rhythmites infine-grained Carboniferous limestones, U.S.A.

    USGS Publications Warehouse

    Archer, A.W.; Feldman, H.R.

    1994-01-01

    Analyses of fine-grained limestones reveals that many exhibit fine-scale laminations. Laminations can be normally graded and consist of a coarser-grained lower part and a finer-grained upper part. The upper part can also contain finely disseminated organic material. Despite the similarities of such graded laminae to yearly varves and turbidites, it can be demonstrated by use of laminae-thickness periodicities that some graded laminae are reasonably interpreted as the product of tidal processes. Within siliciclastic systems, modern analogues of such processes are available for comparisons. In fine-grained facies of the Salem Limestone (Visean; Indiana, U.S.A.), periodicities observed within sequential-laminae thicknesses indicate a dominant control by neap-spring tidal processes. Similarly, laminae within limestones of the vertebrate-bearing Hamilton paleochannel (Stephanian; Kansas, U.S.) exhibit similar features, including fine-scale tidal bundles. This limestone is noted for the abundance of articulated fish fossils. Carbonates containing articulated fish from the Wild Cow Formation (Stephanian; New Mexico, U.S.), exhibit diffuse laminations; however, closely associated siliciclastic mudstones contain laminae that exhibit tidal periodicities. There are many similarities between tidal periodicities and patterns of lamination thicknesses of these rocks. A tidal interpretation for these rocks allows for localized, very rapid rates of deposition. Such rapid deposition may, in part, help to explain how articulated fish and other vertebrates can become preserved within such fine-grained limestones. ?? 1994.

  6. Economic evaluation of advanced limestone, Davy S-H, and Dowa Gypsum-producing FGD processes

    SciTech Connect

    Dotson, R.L.; Maxwell, J.D.; Burnett, T.A.

    1984-02-01

    Economic evaluations were made of three gypsum-producing FGD processes: advanced limestone (in-loop forced oxidation with adipic acid additive), Davy S-H (lime), and Dowa (aluminum sulfate, limestone). For a 500-MW power unit burning 3.5% sulfur coal and meeting the 1979 NSPS, capital investments in 1982 costs are 93 M$ (186 $/kW) for the advanced limestone process, 116 M$ (231 $/kW) for the Davy S-H process, and 121 M$ (243 $/kW) for the Dowa process. First-year annual revenue requirements in 1984 costs for these processes are 26, 33, and 32 M$ (9.4, 11.9, and 11.7 mills/kWh), respectively. The lower capital investment and annual revenue requirements of the advanced limestone process is due in part to the use of adipic acid, which allows partial scrubbing at 95% removal. The Davy S-H has slightly higher annual revenue requirements than the Dowa process because lime rather than limestone is used. Changes in power unit size and coal sulfur content affect the costs of all three processes similarly. The Davy S-H process is more sensitive to raw material costs because lime is used. Landfill waste disposal is a minor cost element in all three processes. 103 references, 26 figures, 30 tables.

  7. Dietary adaptations of Assamese macaques (Macaca assamensis) in limestone forests in Southwest China.

    PubMed

    Huang, Zhonghao; Huang, Chengming; Tang, Chuangbin; Huang, Libin; Tang, Huaxing; Ma, Guangzhi; Zhou, Qihai

    2015-02-01

    Limestone hills are an unusual habitat for primates, prompting them to evolve specific behavioral adaptations to the component karst habitat. From September 2012 to August 2013, we collected data on the diet of one group of Assamese macaques living in limestone forests at Nonggang National Nature Reserve, Guangxi Province, China, using instantaneous scan sampling. Assamese macaques were primarily folivorous, young leaves accounting for 75.5% and mature leaves an additional 1.8% of their diet. In contrast, fruit accounted for only 20.1%. The young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo that is superabundant in limestone hills, comprised the bulk of the average monthly diet. Moreover, macaques consumed significantly more bamboo leaves during the season when the availability of fruit declined, suggesting that bamboo leaves are an important fallback food for Assamese macaques in limestone forests. In addition, diet composition varied seasonally. The monkeys consumed significantly more fruit and fewer young leaves in the fruit-rich season than in the fruit-lean season. Fruit consumption was positively correlated with fruit availability, indicating that fruit is a preferred food for Assamese macaques. Of seventy-eight food species, only nine contributed >0.5% of the annual diet, and together these nine foods accounted for 90.7% of the annual diet. Our results suggest that bamboo consumption represents a key factor in the Assamese macaque's dietary adaptation to limestone habitat.

  8. [Effect of limestone and magnesite application on remediation of acidified forest soil in Chongqing, China].

    PubMed

    Yang, Yong-sen; Duan, Lei; Jin, Teng; Zhao, Da-wei; Zhang, Dong-bao; Hao, Ji-ming

    2006-09-01

    Effect of limestone and magnesite application on remediation of a typical acidified soil under a masson pine (Pinus massoniana) forest at Tieshanping, Chongqing in southwest China was studied through field experiments. The changes of soil water chemistry in different layers within one year after application of limestone or magnesite indicated that the remediation agents leaded to the recovery of acidified soil by significant increase of pH value and concentration of relative cation, i.e., Ca2+ or Mg2+, and notable decrease of inorganic monomeric aluminum (Ali). However, the accelerated leaching of NO3- and SO4(2-) might somewhat counteract the positive effects. Since the limestone powder applied was much finer and thus more soluble than the magnesite powder, it seemed that the addition of limestone was more effective than that of magnesite. However, the application of magnesite could probably improve the nutrient uptake and growth of plant, and thus limestone and magnesite should be used together. The change of soil water chemistry was much more notable in upper layer of soil than lower, which means that it will take long time to achieve the whole profile soil remediation.

  9. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W. )

    1996-01-01

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  10. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W.

    1996-12-31

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  11. Effect of magnesium salts on the sulphation capacity of limestone slurry.

    PubMed

    Ozyuğuran, Ayşe; Altun-Ciftçioğlu, Gökçen; Karatepe, Nilgün; Ersoy-Meriçboyu, Ayşegül

    2006-01-01

    The effect of different magnesium salts such as MgO, MgSO(4).7H2O and Mg(OH)2 on the total sulphation capacities of limestone slurries prepared from five different limestone samples was investigated. Sulphation reactions of slurries were conducted at a constant temperature of 323 K in a gaseous mixture consisting of 5% O2, 10% CO2, 0.5% SO2 and a balance of nitrogene by volume. It was found that the total sulphation capacities of limestone slurries increased with the addition of MgO and Mg(OH)2 salts and decreased with the addition of MgSO4.7H2O salt. Depending on the chemical composition of the limestone samples the total sulphation capacities of limestone slurries were increased between 22.30% and 75.00% by MgO addition and between 23.70% and 69.00% by Mg(OH)2 addition.

  12. Influence of clay swelling on the mechanical behaviour of Egyptian Helwan limestone

    NASA Astrophysics Data System (ADS)

    Aly, Nevin

    2016-04-01

    Clay minerals exist naturally in the majority of different Egyptian limestones types. Changes in the dimensions of clays during swelling / shrinking process induced by changes in the environmental conditions can result in acceleration the deterioration of the hosting stone. Petrographic investigation by scanning - electron microscope (SEM) of Helwan limestone (biomicritic limestone) revealed distribution of a typical smectite morphology (curled - leaf shape) beside abundance of glauconite pellets within the stone material. The clay frication extracted from Helwan reached 10% and oriented aggregates samples were analyzed by X- ray diffraction (XRD) and confirmed the identification of smectite as the main mineral in the clay frication. To study the effect of the clay content on the mechanical behavior of Helwan limestone, hygric swelling test was performed at first by using displacement sensor and then the effect of multiple wetting/ drying cycles on the stone strength was determined using unconfined compressive strength (UCS). Results revealed that there was a significant correlation between degree of swelling of the clay and strength of the limestone.

  13. Depositional facies and diagenetic history of Trenton Limestone in northern Indiana

    SciTech Connect

    Fara, D.R.; Keith, B.D.

    1984-12-01

    Subsurface cores were studied petrographically to determine the facies and diagenetic history of the Trenton Limestone on a regional scale in northern Indiana. The Trenton Limestone is a yellowish olive-gray fossiliferous limestone, which is replaced by a light-gray dolostone in northern Indiana. Facies composing the Trenton are: 1) bryozoan-echinoderm packstone, 2) bryozoan-echinoderm grainstone, 3) bryozoan packstone to wackestone, 4) lime mudstone, and 5) dolostone. The bryozoan-echinoderm packstone is the major facies. Coarse-grained (1-4 mm) grainstones are typically 1 ft (30 cm) thick, have abrupt bases, and become muddy upward. They are considered storm deposits. Hardgrounds occur throughout the limestone facies, but they are most numerous toward the base. These facies indicate deposition below wave base, interrupted by periods of high energy during storms. Fossiliferous white and gray chert nodules are scattered throughout the unit. Also found in the limestone facies are prevalent stylolites and microstylolites, an indication of chemical compaction. The dolostone facies consists of coarsely crystalline (0.4 mm) idiotopic dolomite. Pyrite is associated with the dolomite. Porosity, found only in the dolostone, is discontinuous and characterized as intercrystalline, vuggy, and moldic. Porous zones are commonly oil stained or have been plugged by poikilotopic selentic gypsum. Minor amounts of celestite are found as cavity fillings.

  14. Discrimination of reservoir dolostone within tight limestone using rock physics modeling and pre-stack parameters

    NASA Astrophysics Data System (ADS)

    Park, G.; Lee, B.; Lee, G.

    2013-12-01

    Dolostones may be differentiated from limestones based on various pre-stack seismic parameters as they are denser and faster. However, because the seismic properties of a rock are affected strongly by porosity, porous dolostones may not be significantly denser and faster than limestones. We computed various pre-stack parameters (P-impedance, S-impedance, Vp/Vs, Poisson's ratio, Lamé constants) for tight limestones using the Vp and density logs from a well that penetrated Jurassic carbonate and the Vs log, constructed from the empirical relationships of Vp and Vs. The pre-stack parameters of dolostones with 1% - 40% porosity were estimated based on the bulk and shear moduli and bulk densities computed from the formulas proposed by various workers, including Gassmann equations. Crossplots of the pre-stack parameters show that the Lamé constants (λ, μ) are most effective in differentiating dolostones from limestones. In particular, the λρ -μρ vs. μρ crossplot shows a clear-cut separation of the porous dolostones and tight limestones; the porous dolostones plot exclusively to the left of the λρ -μρ of about 25 GPa.

  15. Impacts of Limestone Multi-particle Size on Production Performance, Egg Shell Quality, and Egg Quality in Laying Hens

    PubMed Central

    Guo, X. Y.; Kim, I. H.

    2012-01-01

    This experiment was conducted to evaluate the effects of single or multi-particle size limestone on the egg shell quality, egg production, egg quality and feed intake in laying hens. A total of 280 laying hens (ISA brown) were used in this 10-wk trial. Laying hens were randomly assigned to 4 treatments with 14 replications per treatment and 5 adjacent cages as a replication (hens were caged individually). The experimental treatments were: i) L, basal diet+10% large particle limestone; ii) LS1, basal diet+8% large particle limestone+2% small particle limestone; iii) LS2, basal diet+6% large particle limestone+4% small particle limestone; iv) S, basal diet+10% small particle limestone. The egg production was unaffected by dietary treatments. The egg weight in S treatment was lighter than other treatments (p<0.05). The egg specific gravity in S treatment was lower than other treatments (p<0.05). The eggshell strength and eggshell thickness in S treatment were decreased when compared with other dietary treatments (p<0.05). The laying hens in LS1 and LS2 treatment had a higher average feed intake than the other two treatments (p<0.05). Collectively, the dietary multi-particle size limestone supplementation could be as efficient as large particle size limestone. PMID:25049635

  16. Impacts of Limestone Multi-particle Size on Production Performance, Egg Shell Quality, and Egg Quality in Laying Hens.

    PubMed

    Guo, X Y; Kim, I H

    2012-06-01

    This experiment was conducted to evaluate the effects of single or multi-particle size limestone on the egg shell quality, egg production, egg quality and feed intake in laying hens. A total of 280 laying hens (ISA brown) were used in this 10-wk trial. Laying hens were randomly assigned to 4 treatments with 14 replications per treatment and 5 adjacent cages as a replication (hens were caged individually). The experimental treatments were: i) L, basal diet+10% large particle limestone; ii) LS1, basal diet+8% large particle limestone+2% small particle limestone; iii) LS2, basal diet+6% large particle limestone+4% small particle limestone; iv) S, basal diet+10% small particle limestone. The egg production was unaffected by dietary treatments. The egg weight in S treatment was lighter than other treatments (p<0.05). The egg specific gravity in S treatment was lower than other treatments (p<0.05). The eggshell strength and eggshell thickness in S treatment were decreased when compared with other dietary treatments (p<0.05). The laying hens in LS1 and LS2 treatment had a higher average feed intake than the other two treatments (p<0.05). Collectively, the dietary multi-particle size limestone supplementation could be as efficient as large particle size limestone.

  17. Exploratory and basic fluidized-bed combustion studies. Quarterly report, April-June 1980. [Limestone and dolomite; USA

    SciTech Connect

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports the development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particles and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutant emissions, and other aspects of fluidized-bed coal combustion. This report presents information on: (1) the development of a sorbent utilization prediction methodology, (2) studies of factors which affect limestone breakup and elutriation, (3) basic studies of limestone sulfation under combustion conditions, and (4) studies of the kinetics of the hydration of spent limestone.

  18. Porosity development in the Copper Ridge Dolomite and Maynardville Limestone, Bear Creek Valley and Chestnut Ridge, Tennessee

    SciTech Connect

    Goldstrand, P.M.; Menefee, L.S.; Dreier, R.B.

    1995-12-01

    Matrix porosity data from deep core obtained in Bear Creek Valley indicate that porosities in the Maynardville Limestone are lithology and depth dependent. Matrix porosities are greater in the Cooper Ridge Dolomite than in the Maynardville Limestone, yet there is no apparent correlation with depth. Two interrelated diagenetic processes are the major controlling factors on porosity development in the Copper Ridge Dolomite and Maynardville Limestone; dissolution of evaporate minerals and dedolomitization. Both of these diagenetic processes produce matrix porosities between 2.1 and 1.3% in the Copper Ridge Dolomite and upper part of the Maynardville Limestone (Zone 6) to depths of approximately 600 ft bgs. Mean matrix porosities in Zones 5 through 2 of the Maynardville Limestone range from 0.8 to 0.5%. A large number of cavities have been intersected during drilling activities in nearly all zones of the Maynardville Limestone in Bear Creek Valley. Therefore, any maynardville Limestone zone within approximately 200 ft of the ground surface is likely to contain cavities that allow significant and rapid flow of groundwater. Zone 6 could be an important stratigraphic unit in the Maynardville Limestone for groundwater flow and contaminant transport because of the abundance of vuggy and moldic porosities. There are large variations in the thickness and lithology in the lower part of the Maynardville (Zones 2, 3, and 4 in the Burial Grounds region). The direction and velocity of strike-parallel groundwater flow may be altered in this area within the lower Maynardville Limestone.

  19. The mechanics of echelon vein and solution seam formation in limestone: examples from the eastern Monument Upwarp, UT

    NASA Astrophysics Data System (ADS)

    Seyum, S.; Pollard, D. D.

    2013-12-01

    Two sets of bed-perpendicular, echelon vein arrays with complementary echelon pressure solution seams are observed in Pennsylvanian to Permian limestone strata across Raplee anticline and the neighboring portion of Comb monocline, Utah. The array sets sometimes appear as conjugate pairs. We demonstrate, using a 2D mechanical model, how the physical attributes of complementary model cracks and seams in an array influence the relative displacements of crack surfaces to form shapes similar to veins observed in the field. Using dimensional analysis we identify the five dimensionless variables necessary to represent this physical model and quantify their effect on the heterogeneous displacement and stress fields. Those five variables are coordinate position, crack spacing (s), crack-array angle (α), array-remote stress angle (γ), and model seam shortening (Δu). We use the commercial finite element software Abaqus to model arrays of cracks and shortening seams in a model limestone having material properties determined from experimental rock mechanics literature (E = 60 GPa; ν = 0.25). Ranges of geometric values for model cracks come from field measurements of veins (half-lengths, apertures, spacing, vein-array angles, angle between conjugate array pairs). Remote boundary conditions (σ1∞ = 65MPa; σ3∞ = 10MPa) and crack boundary conditions (P = 30MPa) are within the range of tectonic conditions inferred from field relationships and the published burial history profile of the stratigraphy. The boundary conditions allow the model cracks to open for all geometric configurations explored here. Magnitudes of model seam shortening are supported by calculations of pressure solution seam shortening from petrographic analyses of rock samples. We compare model crack surface displacements with vein shapes, and analyze crack tip stresses to predict propagation direction. Veins in the field have triangular shapes and have straight traces when viewed perpendicular to bedding

  20. An Action Research Study Investigating Children's Use of an iPad during Free Play in a Kindergarten Classroom: An Exploration of Teaching Pedagogy and Children's Learning, Social Interactions, and Digital Literacy

    ERIC Educational Resources Information Center

    Reynolds-Blankenship, Tara

    2013-01-01

    As part of human development, technology plays an important role in many children's lives. As digital technologies continue to permeate aspects of many children's everyday lives, educators are integrating digital technologies into classroom practices and, as such, have created a need to examine the ways in which children use technologies in their…

  1. An Action Research Study Investigating Children's Use of an iPad during Free Play in a Kindergarten Classroom: An Exploration of Teaching Pedagogy and Children's Learning, Social Interactions, and Digital Literacy

    ERIC Educational Resources Information Center

    Reynolds-Blankenship, Tara

    2013-01-01

    As part of human development, technology plays an important role in many children's lives. As digital technologies continue to permeate aspects of many children's everyday lives, educators are integrating digital technologies into classroom practices and, as such, have created a need to examine the ways in which children use technologies in their…

  2. Origin and Evolution of Limestone Caves of Chhattisgarh and Orissa, India: Role of Geomorphic, Tectonic and Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Gautam, P. K.; Allu, N. C.; Ramesh, R.; Yadava, M. G.; Panigrahi, C. P.

    2014-12-01

    Carbonate rocks undergo karstic process and karst morphology is a key to understand the nature and genesis of caves. The primary energy source for the formation of karst landforms is hydrological cycle. Geomorphic features along with hydrological characteristics provide important information not only on karst formation but also climate and environmental conditions. In this paper, we present the tectonic and geomorphic features that played a role in evolution of caves located in Chhattisgarh and Orissa States of India. The geomorphic and tectonic aspects of Kotumsar, Kailash, and Gupteshwar caves are discussed in relation to the origin and evolution of these caves. Caves are located near the water falls. The area is folded and faulted along the Eastern Ghat Mobile Belt (EGMB) due to tectonic reactivation. Shaly-limestone beds exhibit vertical dipping near Gupteshwar cave, and steeply inclined near Kotumsar and Kailash caves. Indrāvati and Sabari/Kolab tributaries of the Godavari River drain the area. The landscape evolution and the origin of caves in the region is a multistage process, where the lithology, orogeny, fluvial action, and monsoon are the main agents, which is similar to the four state model (Ford and Ewers, 1978). The river basin evolution and regional tectonism also caused the initiation of karstification in the region. The evolution of caves is believed to have taken place in Pre-Pliocene under more humid conditions that coincided with the initiation of monsoon in India. Further, during the Quaternary wet-dry/cold-warm phases altered physical and chemical weathering of limestone rocks. Contrasting relief features of Bastar plateau have also helped the extensive cave formation in the region. The dissolution along weak planes initiated the openings of caves, further enlarged by geomorphic agents. Both monsoon and tectonics have caused fluctuations in water levels along river courses, which acted as active agents in evolution of caves.

  3. Water resources of the Edwards limestone in the San Antonio area, Texas

    USGS Publications Warehouse

    Livingston, Penn; Sayre, A.N.; White, W.N.

    1936-01-01

    The water enters the limestone in a zone of outcrop along the Balcones escarpment, which crosses the northern parts of Bexar and Medina Counties and extends a long distance both to the east and west of these counties. It is estimated that the combined annual losses into the limestone from the Medina, Prio, Dry Prio, Nueces, and Sabinal Rivers and Hondo Creek may average as much as 150,000 acre-feet a year, the equivalent of a continuous flow of about 134,000,000 gallons a day. Smaller streams also contribute to the underground reservoir, and additional recharge is provided from rainfall on the outcrop of the limestone by direct penetration and by seepage from innumerable storm-water channels.

  4. Freshwater biodissolution rates of limestone in the temperate climate of the Dinaric karst in Slovenia

    NASA Astrophysics Data System (ADS)

    Mulec, J.; Prelovšek, M.

    2015-01-01

    Dissolution rates in two freshwater karst systems were determined by using tablets of dense micrite-biopelmicrite Cretaceous limestone. Submerged limestone tablets in riverbeds were subjected to a natural gradient from complete darkness to direct sunlight. Higher light rates significantly (p < 0.05) increased the epilithic biomass of phototrophs and the overall dissolution rates, which were highest at the Unica spring (- 49.2 μm a- 1), but the exact portion of light-dependent dissolution remains elusive. In the karst river Unica, with its big fluctuations in environmental parameters (e.g., discharge), light rates can be used in estimating the dissolution rates enhanced by phototrophs. Natural biofilms in aquatic systems have important implications for landform evolution, and the impact on limestone dissolution rates is comparable with rates of debris falling from steep slopes.

  5. Optimization of limestone sizing for CFB combustors: Results of pilot plant and bench-scale testing

    SciTech Connect

    Alliston, M.; Edvardsson, C.; Wu, S.; Probst, S.

    1994-12-31

    A grant to study the performance of limestones in a Circulating Fluidized Bed Combustor was obtained in 1991 from the Pennsylvania Energy Development Authority (PEDA) by Tampella Power Corporation (TPC). The overall objective of this PEDA project was to carry out a systematic pilot plant tests at TPC`s pilot plant in Williamsport, Pennsylvania, in systematic order to identify ways of improving sulfur capture and limestone utilization through better control of the size distribution and residence time of the limestone particles in the furnace. It was also an objective to determine if bench scale testing could be of value in predicting CFB sorbent behavior. The pilot plant and bench test results were incorporated into an empirical Correlation which accounts for the size distribution and residence time of solids in CFB boiler.

  6. Microfacies and diagenesis of Gua Bama limestone, Pahang Darul Makmur, Malaysia

    NASA Astrophysics Data System (ADS)

    Joeharry, Nelisa Ameera Mohamed; Ali, Che Aziz; Leman, Mohd Shafeea; Mohamed, Kamal Roslan

    2016-11-01

    Gua Bama limestone hill in Lipis District, Pahang State is a well-known site for the hunt of Malaysian Permo-Triassic Boundary. This paper details the microfacies and diagenesis of limestone succession at Gua Bama outcrop as an early effort to constrain the desired Permo-Triassic Boundary. Six microfacies have been identified: mudstone, peloidal wackestone, bioclastic wackestone, radiolarian wackestone, intraclastic packstone, and peloidal packstone. The appearance of highly diverse benthic fauna in fragmented forms and the dominance of mudstone-wackestone microfacies prove that carbonates of Gua Bama were deposited in low-energy shallow marine environment. Gua Bama have been subjected to multiple diagenetic processes, namely cementation, compaction, neomorphism, and micritization. Based on diagenetic textures observed, it can be interpreted that Gua Bama limestone had undergone diagenesis within marine water phreatic zone and deep burial realms.

  7. Chitinozoans in the Ordovician (Caradocian) Ridley and Pierce Limestones of central Tennessee

    SciTech Connect

    Kessler, T.E.; Siesser, W.G. )

    1990-04-01

    Chitinozoans are an extinct group of organic microfossils of uncertain biological affinity. In shape, they resemble minute (50{mu}m-2,000{mu}m) flasks and vases. Chitinozoan fossils occur in marine sedimentary rocks ranging from Cambrian to Carboniferous in age. Chitinozoan diversity is low in the Ridley and Pierce Limestones. Thirteen taxa were identified; two were left in open nomenclature, and one (Conochitina ridleyensis) is provisionally considered to be a new species. Low chitinozoan abundance and the sporadic distribution of chitinozoans in the Ridley and Pierce Limestones is believed to be the result of variable environmental conditions associated with a marine, shallow-shelf environment. The short-ranging chitinozoan taxa Lagenochitina baltica, Conochitina robusta, and Rhabdochitina turgida allow an accurate age assignment to be made for the Ridley and Pierce Limestones. These formations can now be correlated with the Conochitina hirsuta-Lagenochitina sp. A biozone, indicating an upper Blackriveran (mid-Caradocian) age assignment.

  8. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    NASA Astrophysics Data System (ADS)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  9. Search for high-calcium limestone in Silurian reefs of northern Indiana.

    USGS Publications Warehouse

    Ault, C.H.; Carr, D.D.

    1981-01-01

    During Silurian time, the Indiana part of the Wabash Platform was a shallow-water area between the proto-Illinois and proto- Michigan Basins and a site of growth of hundreds, or perhaps thousands, of reefs. Today, most reefs of northern Indiana are dolomite, but some are dolomitic limestone, and a few are limestone of high purity in deposits that can be mined by openpit methods. Four of the five generations of reefs of Silurian age in the Great Lakes area have been recognized in northern Indiana. All known limestone reefs are restricted to an area of six countries in north-central Indiana, although no apparent depositional environment as revealed from study of surrounding inter-reef rocks has been found to account for any restriction. Dolomitization is more likely related to the textures and lithologies of the individual reefs.-from Authors

  10. Prediction of Building Limestone Physical and Mechanical Properties by Means of Ultrasonic P-Wave Velocity

    PubMed Central

    Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

    2014-01-01

    The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r 2 between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced. PMID:24511286

  11. Prediction of building limestone physical and mechanical properties by means of ultrasonic P-wave velocity.

    PubMed

    Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

    2014-01-01

    The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r(2) between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced.

  12. Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

    PubMed

    McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

    2006-01-01

    Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering.

  13. Franciscan complex calera limestones: Accreted remnants of farallon plate oceanic plateaus

    USGS Publications Warehouse

    Tarduno, J.A.; McWilliams, M.; Debiche, M.G.; Sliter, W.V.; Blake, M.C.

    1985-01-01

    The Calera Limestone, part of the Franciscan Complex of northern California, may have formed in a palaeoenvironment similar to Hess and Shatsky Rises of the present north-west Pacific1. We report here new palaeomagnetic results, palaeontological data and recent plate-motion models that reinforce this assertion. The Calera Limestone may have formed on Farallon Plate plateaus, north of the Pacific-Farallon spreading centre as a counterpart to Hess or Shatsky Rises. In one model2, the plateaus were formed by hotspots close to the Farallon_Pacific ridge axis. On accretion to North America, plateau dissection in the late Cretaceous to Eocene (50-70 Myr) could explain the occurrence of large volumes of pillow basalt and exotic blocks of limestone in the Franciscan Complex. Partial subduction of the plateaus could have contributed to Laramide (70-40 Myr) compressional events3. ?? 1985 Nature Publishing Group.

  14. Low NO/sub x/ combustion systems with SO2 control using limestone

    SciTech Connect

    Drehmel, D.C.; Martin, G.B.; Milliken, J.O.; Abbott, J.H.

    1985-07-01

    The paper describes EPA work on low-NO/sub x/ combustion systems with SO2 control using limestone. Although SO2 control in low-NO/sub x/ systems for both stoker and pulverized-coal-fired furnaces is under investigation at EPA, most of the current work is with pulverized coal. EPA's Limestone Injection Multistage Burners (LIMB) program is an effort to develop an effective but inexpensive emission control technology for pulverized-coal boilers that will simultaneously remove SOx and NOx from boiler flue gases. The technology is based on the use of low-NO/sub x/ combustion techniques in combination with dry limestone injection into the furnace (combustion chamber) for simultaneous SOx control. The program goal is to develop the technology to obtain substantial reductions in SOx and NOx emissions for a capital investment cost of 30-40 $/kW -- less than 20% of the capital cost of conventional flue-gas-desulfurization systems.

  15. Stratigraphy and depositional history of the Iola Limestone Upper Pennsylvanian (Missourian), Northern Midcontinent U.S.

    NASA Astrophysics Data System (ADS)

    Mitchell, J. C.

    The Iola Limestone, one of the best developed and most laterally extensive, yet least studied Missourian cyclic carbonates in the Midcontinent Upper Pennsylvanian, was studied. Along with adjacent shales, five members constitute the Iola cyclothem, a typical Kansas cyclothem. In ascending order these are: Chanute Shale; Paola Limestone; Munice Creek Shale; Raytown Limestone; and Lane/Bonner Springs Shale. Although traditional interpretation of cyclothems regarded all shale as nearshore, shallow-water deposits, Iola lithology and stratigraphy support the more recent hypothesis that the cyclothem represents a single transgressive-regressive event, with maximum transgression occurring during deposition of the Muncie Creek Shale. Distribution of conodonts reflects the depositional pattern of the Iola cyclothem. Vertical variation far outweighs lateral variation in abundance and diversity.

  16. Successful experience with limestone and other sorbents for combustion of biomass in fluid bed power boilers

    SciTech Connect

    Coe, D.R.

    1993-12-31

    This paper presents the theoretical and practical advantages of utilizing limestone and other sorbents during the combustion of various biomass fuels for the reduction of corrosion and erosion of boiler fireside tubing and refractory. Successful experiences using a small amount of limestone, dolomite, kaolin, or custom blends of aluminum and magnesium compounds in fluid bed boilers fired with biomass fuels will be discussed. Electric power boiler firing experience includes bubbling bed boilers as well as circulating fluid bed boilers in commercial service on biomass fuels. Forest sources of biomass fuels fired include wood chips, brush chips, sawmill waste wood, bark, and hog fuel. Agricultural sources of biomass fuels fired include grape vine prunings, bean straw, almond tree chips, walnut tree chips, and a variety of other agricultural waste fuels. Additionally, some urban sources of wood fuels have been commercially burned with the addition of limestone. Data presented includes qualitative and quantitative analyses of fuel, sorbent, and ash.

  17. Transport mechanisms and genesis of limestone clast conglomerates with examples from Cambrian of east Tennessee

    SciTech Connect

    Kozar, M.G.; Weber, L.J.; Walker, K.R.

    1986-05-01

    Limestone clast conglomerates are common sedimentary features of most Cambrian strata. Cambrian researchers have considered many of these conglomeratic deposits to have formed from erosion and redeposition of partially lithified sediments by storm currents in shallow subtidal and intertidal environments. Analysis of conglomeratic beds from the Middle and Late Cambrian (Maryville Limestone and Nolichucky Shale) in east Tennessee suggests that other, more dominant, processes were responsible for their genesis and transport. The proposed processes may serve as an alternative explanation for limestone clast conglomerates deposited elsewhere in Cambrian sequences. As the authors gain a greater understanding of transport mechanisms and their resultant sedimentary features, many of the conglomeratic beds that were once thought to be the result of storms may be reinterpreted as mass-gravity flows. Differentiating between these various types of transport mechanisms may be crucial to paleo-environmental interpretation.

  18. Effects of magnesium and chloride ions on limestone dual-alkali-system performance

    SciTech Connect

    Chang, J.C.S.; Kaplan, N.; Brna, T.G.

    1985-08-01

    The paper gives results of pilot plant tests to evaluate the effects of magnesium and chloride ions on system performance of limestone-regenerated dual alkali processes under closed-loop operating conditions. It was found that limestone reactivity and solids dewatering properties are very sensitive to magnesium ion concentrations. The total magnesium ion concentration should be maintained below 1000 ppm for satisfactory performance under normal operation. A model which assumes competitive surface adsorption of calcium and magnesium ions was used to interpret the data. Limestone reactivity and solids dewatering properties decreased with the increase of chloride ion concentrations; however, the effect of chloride ion accumulation was not significant until the concentration reached 80,000 ppm.

  19. Thermochemical degradation of limestone aggregate concrete on exposure to sodium fire

    NASA Astrophysics Data System (ADS)

    Premila, M.; Sivasubramanian, K.; Amarendra, G.; Sundar, C. S.

    2008-04-01

    Limestone aggregate concrete blocks were subjected to sodium fire conforming to a realistic scenario in order to qualify them as protective sacrificial layers over structural concrete flooring in liquid metal-cooled fast breeder reactors. Mid infrared absorption measurements were carried out on these sodium fire-exposed samples as a function of depth from the affected surface. Definite signatures of thermochemical degradation indicating dehydration and structural modification of the limestone concrete have been obtained. Control runs were carried out to delineate the thermal effects of sodium fires from that of the chemical interaction effects. Measurements on limestone aggregate samples treated with fused NaOH provided direct evidence of the exact mechanism of the sodium attack on concrete. The observed degradation effects were correlated to the mechanical strength of the concrete blocks and to the intensity of the sodium fire experienced.

  20. Suitability of two types of organic wastes for the growth of sclerophyllous shrubs on limestone debris: a mesocosm trial.

    PubMed

    Maisto, G; De Marco, A; De Nicola, F; Arena, C; Vitale, L; Virzo De Santo, A

    2010-03-01

    This study investigated whether overlaying organic wastes directly on limestone debris allowed the growth of sclerophyllous shrubs; the aim was to explore the feasibility of rehabilitation of sites destroyed by quarrying activity. In an open air mesocosm experiment two types of organic material were compared: compost from municipal wastes (C) and a mixture of compost and poultry manure added with wheat husk (C-PW). Mesocosms were pots (1m diameter, 60cm height) containing limestone debris covered by the organic material. Seven mesocosms with C and seven mesocosms with C-PW were planted with sclerophyllous shrubs (Laurus nobilis L., Phillyrea angustifolia L. and Quercus ilex L.). The substrates were characterised in terms of chemical and physical parameters, microbial activity and biomass, and total and active fungal biomass. Shrub photosynthetic performance and growth were evaluated. Over the whole experimental period, organic matter mineralization was higher in C-PW. Microbial biomass and respiration were higher in C-PW than in C but after one year no statistically significant difference between the two substrates occurred. Fungal mycelium was a minor fraction of the microbial community in both types of substrates and decreased dramatically after setting up the mesocosms. The metabolic quotient was higher in C suggesting more stressful conditions as compared to C-PW. Both substrates allowed shrub growth; however photosynthetic rates and the increase of plant size were higher on C-PW than on C. The results demonstrated that, as compared to only compost, the mixture of compost and poultry manure added with wheat husk is a substrate more suitable to both microbial processes and plant growth. Therefore a plan to revegetate quarries based on the use of organic wastes as a substrate for sclerophyllous shrubs could be feasible and, what is more, helpful to mitigate the environmental impact of organic wastes disposal.