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Sample records for chalk river nuclear labs

  1. Brockhouse and others: Neutron Scattering and Condensed Matter Physics at Chalk River Labs

    NASA Astrophysics Data System (ADS)

    Svensson, Eric

    2004-03-01

    Bertram Brockhouse, in brilliant, pioneering work carried out during the period 1950-1962 at Chalk River Laboratories, laid the foundation for the field of inelastic neutron scattering. Bert invented/developed an abundance of new instrumentation (most notably the Triple Axis Crystal Spectrometer) and techniques (most notably the Constant-Q Method) and he and his collaborators carried out a truly impressive number of ground breaking measurements. These included the first determination of phonon dispersion curves (in aluminum in 1955, with Alec Stewart), the first determination of a magnon dispersion curve (in magnetite in 1958), the first measurements of phonons in semiconductors, alkali halides and several other metals, the first measurements of magnons in a metal (cobalt), and the first observation of a Kohn anomaly. Bert Brockhouse was a great scientist with an amazing intuition, but, as he regularly emphasized, the terrific atmosphere for scientific research at Chalk River Labs as well as the outstanding technical support staff and facilities were essential ingredients of his success. He also had unlimited access to, in succession, the NRX and NRU reactors which were, when they were commissioned (in 1947 and 1957) and for several years thereafter, the best research reactors in the world. Bert's accomplishments were ultimately recognized by the 1994 Nobel Prize in Physics, which he shared with Clifford Shull of the United States, Cliff having laid the foundation for the field of elastic neutron scattering. My presentation will focus strongly on the work of Brockhouse, but I will also cover several highlights from the Chalk River program of neutron scattering studies on liquid helium, started in 1952 by Dave Henshaw and Don Hurst. (Don Hurst was the person who hired Bert Brockhouse and charged him with "finding something interesting to do with neutrons".) The helium program, now running almost continuously for half a century, has been a major focus of my own

  2. Radiochemistry Lab Decommissioning and Dismantlement. AECL, Chalk River Labs, Ontario, Canada

    SciTech Connect

    Kenny, Stephen

    2008-01-15

    Atomic Energy of Canada (AECL) was originally founded in the mid 1940's to perform research in radiation and nuclear areas under the Canadian Defense Department. In the mid 50's The Canadian government embarked on several research and development programs for the development of the Candu Reactor. AECL was initially built as a temporary site and is now faced with many redundant buildings. Prior to 2004 small amounts of Decommissioning work was in progress. Many reasons for deferring decommissioning activities were used with the predominant ones being: 1. Reduction in radiation doses to workers during the final dismantlement, 2. Development of a long-term solution for the management of radioactive wastes in Canada, 3. Financial constraints presented by the number of facilities shutdown that would require decommissioning funds and the absence of an approved funding strategy. This has led to the development of a comprehensive decommissioning plan that is all inclusive of AECL's current and legacy liabilities. Canada does not have a long-term disposal site; therefore waste minimization becomes the driving factor behind decontamination for decommissioning before and during dismantlement. This decommissioning job was a great learning experience for decommissioning and the associated contractors who worked on this project. Throughout the life of the project there was a constant focus on waste minimization. This focus was constantly in conflict with regulatory compliance primarily with respect to fire regulations and protecting the facility along with adjacent facilities during the decommissioning activities. Discrepancies in historical documents forced the project to treat every space as a contaminated space until proven differently. Decommissioning and dismantlement within an operating site adds to the complexity of the tasks especially when it is being conducted in the heart of the plant. This project was very successful with no lost time accidents in over one hundred

  3. Management of Legacy Spent Nuclear Fuel Wastes at the Chalk River Laboratories: The Challenges and Innovative Solutions Implemented - 13301

    SciTech Connect

    Schruder, Kristan; Goodwin, Derek

    2013-07-01

    AECL's Fuel Packaging and Storage (FPS) Project was initiated in 2004 to retrieve, transfer, and stabilize an identified inventory of degraded research reactor fuel that had been emplaced within in-ground 'Tile Hole' structures in Chalk River Laboratories' Waste Management Area in the 1950's and 60's. Ongoing monitoring of the legacy fuel storage conditions had identified that moisture present in the storage structures had contributed to corrosion of both the fuel and the storage containers. This prompted the initiation of the FPS Project which has as its objective to design, construct, and commission equipment and systems that would allow for the ongoing safe storage of this fuel until a final long-term management, or disposition, pathway was available. The FPS Project provides systems and technologies to retrieve and transfer the fuel from the Waste Management Area to a new facility that will repackage, dry, safely store and monitor the fuel for a period of 50 years. All equipment and the new storage facility are designed and constructed to meet the requirements for Class 1 Nuclear Facilities in Canada. (authors)

  4. Fifty years of accelerator based physics at Chalk River

    SciTech Connect

    McKay, John W.

    1999-04-26

    The Chalk River Laboratories of Atomic Energy of Canada Ltd. was a major centre for Accelerator based physics for the last fifty years. As early as 1946, nuclear structure studies were started on Cockroft-Walton accelerators. A series of accelerators followed, including the world's first Tandem, and the MP Tandem, Superconducting Cyclotron (TASCC) facility that was opened in 1986. The nuclear physics program was shut down in 1996. This paper will describe some of the highlights of the accelerators and the research of the laboratory.

  5. Risk-based Prioritization of Facility Decommissioning and Environmental Restoration Projects in the National Nuclear Legacy Liabilities Program at the Chalk River Laboratory - 13564

    SciTech Connect

    Nelson, Jerel G.; Kruzic, Michael; Castillo, Carlos; Pavey, Todd; Alexan, Tamer; Bainbridge, Ian

    2013-07-01

    Chalk River Laboratory (CRL), located in Ontario Canada, has a large number of remediation projects currently in the Nuclear Legacy Liabilities Program (NLLP), including hundreds of facility decommissioning projects and over one hundred environmental remediation projects, all to be executed over the next 70 years. Atomic Energy of Canada Limited (AECL) utilized WorleyParsons to prioritize the NLLP projects at the CRL through a risk-based prioritization and ranking process, using the WorleyParsons Sequencing Unit Prioritization and Estimating Risk Model (SUPERmodel). The prioritization project made use of the SUPERmodel which has been previously used for other large-scale site prioritization and sequencing of facilities at nuclear laboratories in the United States. The process included development and vetting of risk parameter matrices as well as confirmation/validation of project risks. Detailed sensitivity studies were also conducted to understand the impacts that risk parameter weighting and scoring had on prioritization. The repeatable prioritization process yielded an objective, risk-based and technically defendable process for prioritization that gained concurrence from all stakeholders, including Natural Resources Canada (NRCan) who is responsible for the oversight of the NLLP. (authors)

  6. Isotope hydrology of the Chalk River Laboratories site, Ontario, Canada

    USGS Publications Warehouse

    Peterman, Zell; Neymark, Leonid; King-Sharp, K.J.; Gascoyne, Mel

    2016-01-01

    This paper presents results of hydrochemical and isotopic analyses of groundwater (fracture water) and porewater, and physical property and water content measurements of bedrock core at the Chalk River Laboratories (CRL) site in Ontario. Density and water contents were determined and water-loss porosity values were calculated for core samples. Average and standard deviations of density and water-loss porosity of 50 core samples from four boreholes are 2.73 ± 12 g/cc and 1.32 ± 1.24 percent. Respective median values are 2.68 and 0.83 indicating a positive skewness in the distributions. Groundwater samples from four deep boreholes were analyzed for strontium (87Sr/86Sr) and uranium (234U/238U) isotope ratios. Oxygen and hydrogen isotope analyses and selected solute concentrations determined by CRL are included for comparison. Groundwater from borehole CRG-1 in a zone between approximately +60 and −240 m elevation is relatively depleted in δ18O and δ2H perhaps reflecting a slug of water recharged during colder climatic conditions. Porewater was extracted from core samples by centrifugation and analyzed for major dissolved ions and for strontium and uranium isotopes. On average, the extracted water contains 15 times larger concentration of solutes than the groundwater. 234U/238U and correlation of 87Sr/86Sr with Rb/Sr values indicate that the porewater may be substantially older than the groundwater. Results of this study show that the Precambrian gneisses at Chalk River are similar in physical properties and hydrochemical aspects to crystalline rocks being considered for the construction of nuclear waste repositories in other regions.

  7. An Investigation into the Transportation of Irradiated Uranium/Aluminum Targets from a Foreign Nuclear Reactor to the Chalk River Laboratories Site in Ontario, Canada - 12249

    SciTech Connect

    Clough, Malcolm; Jackson, Austin

    2012-07-01

    This investigation required the selection of a suitable cask and development of a device to hold and transport irradiated targets from a foreign nuclear reactor to the Chalk River Laboratories in Ontario, Canada. The main challenge was to design and validate a target holder to protect the irradiated HEU-Al target pencils during transit. Each of the targets was estimated to have an initial decay heat of 118 W prior to transit. As the targets have little thermal mass the potential for high temperature damage and possibly melting was high. Thus, the primary design objective was to conceive a target holder to dissipate heat from the targets. Other design requirements included securing the targets during transportation and providing a simple means to load and unload the targets while submerged five metres under water. A unique target holder (patent pending) was designed and manufactured together with special purpose experimental apparatus including a representative cask. Aluminum dummy targets were fabricated to accept cartridge heaters, to simulate decay heat. Thermocouples were used to measure the temperature of the test targets and selected areas within the target holder and test cask. After obtaining test results, calculations were performed to compensate for differences between experimental and real life conditions. Taking compensation into consideration the maximum target temperature reached was 231 deg. C which was below the designated maximum of 250 deg. C. The design of the aluminum target holder also allowed generous clearance to insert and unload the targets. This clearance was designed to close up as the target holder is placed into the cavity of the transport cask. Springs served to retain and restrain the targets from movement during transportation as well as to facilitate conductive heat transfer. The target holder met the design requirements and as such provided data supporting the feasibility of transporting targets over a relatively long period of time

  8. Widespread methanotrophic primary production in lowland chalk rivers

    PubMed Central

    Shelley, Felicity; Grey, Jonathan; Trimmer, Mark

    2014-01-01

    Methane is oversaturated relative to the atmosphere in many rivers, yet its cycling and fate is poorly understood. While photosynthesis is the dominant source of autotrophic carbon to rivers, chemosynthesis and particularly methane oxidation could provide alternative sources of primary production where the riverbed is heavily shaded or at depth beneath the sediment surface. Here, we highlight geographically widespread methanotrophic carbon fixation within the gravel riverbeds of over 30 chalk rivers. In 15 of these, the potential for methane oxidation (methanotrophy) was also compared with photosynthesis. In addition, we performed detailed concurrent measurements of photosynthesis and methanotrophy in one large chalk river over a complete annual cycle, where we found methanotrophy to be active to at least 15 cm into the riverbed and to be strongly substrate limited. The seasonal trend in methanotrophic activity reflected that of the riverine methane concentrations, and thus the highest rates were measured in mid-summer. At the sediment surface, photosynthesis was limited by light for most of the year with heavy shading induced by dense beds of aquatic macrophytes. Across 15 rivers, in late summer, we conservatively calculated that net methanotrophy was equivalent to between 1% and 46% of benthic net photosynthetic production within the gravel riverbed, with a median value of 4%. Hence, riverbed chemosynthesis, coupled to the oxidation of methane, is widespread and significant in English chalk rivers. PMID:24695425

  9. Widespread methanotrophic primary production in lowland chalk rivers.

    PubMed

    Shelley, Felicity; Grey, Jonathan; Trimmer, Mark

    2014-05-22

    Methane is oversaturated relative to the atmosphere in many rivers, yet its cycling and fate is poorly understood. While photosynthesis is the dominant source of autotrophic carbon to rivers, chemosynthesis and particularly methane oxidation could provide alternative sources of primary production where the riverbed is heavily shaded or at depth beneath the sediment surface. Here, we highlight geographically widespread methanotrophic carbon fixation within the gravel riverbeds of over 30 chalk rivers. In 15 of these, the potential for methane oxidation (methanotrophy) was also compared with photosynthesis. In addition, we performed detailed concurrent measurements of photosynthesis and methanotrophy in one large chalk river over a complete annual cycle, where we found methanotrophy to be active to at least 15 cm into the riverbed and to be strongly substrate limited. The seasonal trend in methanotrophic activity reflected that of the riverine methane concentrations, and thus the highest rates were measured in mid-summer. At the sediment surface, photosynthesis was limited by light for most of the year with heavy shading induced by dense beds of aquatic macrophytes. Across 15 rivers, in late summer, we conservatively calculated that net methanotrophy was equivalent to between 1% and 46% of benthic net photosynthetic production within the gravel riverbed, with a median value of 4%. Hence, riverbed chemosynthesis, coupled to the oxidation of methane, is widespread and significant in English chalk rivers.

  10. Progress in radiocarbon dating with the Chalk River MP tandem accelerator

    SciTech Connect

    Andrews, H.R.; Ball, G.C.; Brown, R.M.; Davies, W.G.; Imahori, Y.; Milton, J.C.D.

    1980-01-01

    The evolution of a tandem accelerator /sup 14/C dating system at Chalk River is recounted. Background problems and sources of instability are discussed and solutions are described. Details of sample chemistry and source preparation are presented.

  11. Contaminated groundwater characterization at the Chalk River Laboratories, Ontario, Canada

    SciTech Connect

    Schilk, A.J.; Robertson, D.E.; Thomas, C.W.; Lepel, E.A.; Champ, D.R.; Killey, R.W.D.; Young, J.L.; Cooper, E.L.

    1993-03-01

    The licensing requirements for the disposal of low-level radioactive waste (10 CFR 61) specify the performance objectives and technical requisites for federal and commercial land disposal facilities, the ultimate goal of which is to contain the buried wastes so that the general population is adequately protected from harmful exposure to any released radioactive materials. A major concern in the operation of existing and projected waste disposal sites is subterranean radionuclide transport by saturated or unsaturated flow, which could lead to the contamination of groundwater systems as well as uptake by the surrounding biosphere, thereby directly exposing the general public to such materials. Radionuclide transport in groundwater has been observed at numerous commercial and federal waste disposal sites [including several locations within the waste management area of Chalk River Laboratories (CRL)], yet the physico-chemical processes that lead to such migration are still not completely understood. In an attempt to assist in the characterization of these processes, an intensive study was initiated at CRL to identify and quantify the mobile radionuclide species originating from three separate disposal sites: (a) the Chemical Pit, which has received aqueous wastes containing various radioisotopes, acids, alkalis, complexing agents and salts since 1956, (b) the Reactor Pit, which has received low-level aqueous wastes from a reactor rod storage bay since 1956, and (c) the Waste Management Area C, a thirty-year-old series of trenches that contains contaminated solid wastes from CRL and various regional medical facilities. Water samples were drawn downgradient from each of the above sites and passed through a series of filters and ion-exchange resins to retain any particulate and dissolved or colloidal radionuclide species, which were subsequently identified and quantified via radiochemical separations and gamma spectroscopy. These groundwaters were also analyzed for anions

  12. Response of invertebrates from the hyporheic zone of chalk rivers to eutrophication and land use.

    PubMed

    Pacioglu, Octavian; Moldovan, Oana Teodora

    2016-03-01

    Whereas the response of lotic benthic macroinvertebrates to different environmental stressors is a widespread practice nowadays in assessing the water and habitat quality, the use of hyporheic zone invertebrates is still in its infancy. In this study, classification and regression trees analysis were employed in order to assess the ecological requirements and the potential as bioindicators for the hyporheic zone invertebrates inhabiting four lowland chalk rivers (south England) with contrasting eutrophication levels (based on surface nitrate concentrations) and magnitude of land use (based on percentage of fine sediments load and median interstitial space). Samples of fauna, water and sediment were sampled twice, during low (summer) and high (winter) groundwater level, at depths of 20 and 35 cm. Certain groups of invertebrates (Glossosomatidae and Psychomyiidae caddisflies, and riffle beetles) proved to be good indicators of rural catchments, moderately eutrophic and with high fine sediment load. A diverse community dominated by microcrustaceans (copepods and ostracods) were found as good indicators of highly eutrophic urban streams, with moderate-high fine sediment load. However, the use of other taxonomic groups (e.g. chironomids, oligochaetes, nematodes, water mites and the amphipod Gammarus pulex), very widespread in the hyporheic zone of all sampled rivers, is of limited use because of their high tolerance to the analysed stressors. We recommend the use of certain taxonomic groups (comprising both meiofauna and macroinvertebrates) dwelling in the chalk hyporheic zone as indicators of eutrophication and colmation and, along with routine benthic sampling protocols, for a more comprehensive water and habitat quality assessment of chalk rivers.

  13. Removal of Chalk River unidentified deposit (CRUD) radioactive waste by enhanced electrokinetic process

    DOE PAGES

    Kim, Won-Seok; Nam, Seongsik; Chang, Seeun; ...

    2017-08-13

    Decontamination techniques proposed and used to remove Chalk River unidentified deposit (CRUD) in radioactive waste management. In cases of huge volumes of metal or radionuclides contaminated by CRUD, removal of CRUD by mechanical or chemical decontamination is difficult. An advanced electrokinetic process combined with chemical decontamination was applied to remove CRUD and experimentally evaluated. We used oxalic acid for CRUD removal, and cobalt (Co) released from the CRUD was transferred to the cathode in an electrokinetic reactor. Our results indicate that the combined system is efficient for CRUD removal with enhanced, efficiency by use of the cation exchange membrane andmore » zeolite.« less

  14. Overview of the 1994 chronic HT release experiment at Chalk River

    SciTech Connect

    Davis, P.A.; Workman, W.J.G.; Amiro, B.D.; Spencer, F.S.; Noguchi, H.; Amano, H.; Ichimasa, Y.; Ichimasa, M.

    1995-10-01

    Trace amounts of tritiated hydrogen (HT) were released continuously to the atmosphere at Chalk River Laboratories over the 12-day period 1994 July 27 to August 8. Scientists from eight institutions in four countries took extensive air, soil and vegetation samples to study the dynamics of tritiated water (HTO) and organically-bound tritium (OBT) formation, and the environmental concentrations of these compounds at steady-state. The short-term HT air concentrations varied strongly in time and space over the test area, but the variation decreased rapidly as the averaging time increased. HTO concentrations in soil, vegetation and air built up gradually over time but they fluctuated substantially with ambient meteorological conditions, particularly rainfall. OBT concentrations in plants increased throughout the period. HTO concentrations were at or near steady-state at the end of the release, but OBT levels were continuing to rise. 8 refs., 2 figs., 1 tab.

  15. Transport of three herbicides in ground water at Twin Lake test site, Chalk River, Ontario, Canada.

    PubMed

    Maloszewski, P; Zuber, A; Bedbur, E; Matthess, G

    2003-01-01

    A field tracer test performed under natural flow conditions at the Twin Lake test site, Chalk River Laboratories of the Atomic Energy of Canada Ltd. in Chalk River, Ontario, Canada, using tritium and three herbicides (Chlortoluron, Terbuthylazine, and Pendimethalin) was interpreted using the dispersion equation with a combined reaction model. The reaction model couples an instantaneous equilibrium reaction governed by a linear adsorption isotherm with a reversible or irreversible kinetic reaction of the first order, and decay. An improved interpretation method consists of a simultaneous fitting of theoretical concentration and mass-recovery curves to the experimental data, which leads to a more reliable determining of reaction models and improves the accuracy of fitting. Tritium served as the reference tracer to determine the flow velocity, dispersivity, and the recovery of the herbicides. Chlortoluron was slightly delayed by equilibrium exchange with strongly reduced concentration due to an irreversible kinetic reaction and/or decay. Terbuthilazine was slightly delayed by equilibrium exchange, with strongly reduced concentration due to a reversible kinetic reaction with some influence of decay. A strong equilibrium reaction and a strong reversible kinetic reaction without degradation governed the transport of Pendimethalin, reducing considerably its concentration. The results obtained show that simulations based only on Kd and decay constant, especially if these parameters are found in the laboratory, may considerably differ from those performed with reaction parameters determined in properly performed field tests. The dominant reaction types, and the values of parameters found in the study, supply useful information on the transport of the investigated herbicides in sandy aquifers under natural flow conditions.

  16. HTO and OBT activity concentrations in soil at the historical atmospheric HT release site (Chalk River Laboratories).

    PubMed

    Kim, S B; Bredlaw, M; Korolevych, V Y

    2012-01-01

    Tritium is routinely released by the Chalk River Laboratories (CRL) nuclear facilities. Three International HT release experiments have been conducted at the CRL site in the past. The site has not been disturbed since the last historical atmospheric testing in 1994 and presents an opportunity to assess the retention of tritium in soil. This study is devoted to the measurement of HTO and OBT activity concentration profiles in the subsurface 25 cm of soil. In terms of soil HTO, there is no evidence from the past HT release experiments that HTO was retained. The HTO activity concentration in the soil pore water appears similar to concentrations found in background areas in Ontario. In contrast, OBT activity concentrations in soil at the same site were significantly higher than HTO activity concentrations in soil. Elevated OBT appears to reside in the top layer of the soil (0-5 cm). In addition, OBT activity concentrations in the top soil layer did not fluctuate much with season, again, quite in contrast with soil HTO. This result suggests that OBT activity concentrations retained the signature of the historical tritium releases. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  17. Development of an Integrated Waste Plan for Chalk River Laboratories - 13376

    SciTech Connect

    Jones, L.

    2013-07-01

    To further its Strategic Planning, the Atomic Energy of Canada Limited (AECL) required an effective approach to developing a fully integrated waste plan for its Chalk River Laboratories (CRL) site. Production of the first Integrated Waste Plan (IWP) for Chalk River was a substantial task involving representatives from each of the major internal stakeholders. Since then, a second revision has been produced and a third is underway. The IWP remains an Interim IWP until all gaps have been resolved and all pathways are at an acceptable level of detail. Full completion will involve a number of iterations, typically annually for up to six years. The end result of completing this process is a comprehensive document and supporting information that includes: - An Integrated Waste Plan document summarizing the entire waste management picture in one place; - Details of all the wastes required to be managed, including volume and timings by waste stream; - Detailed waste stream pathway maps for the whole life-cycle for each waste stream to be managed from pre-generation planning through to final disposition; and - Critical decision points, i.e. decisions that need to be made and timings by when they need to be made. A waste inventory has been constructed that serves as the master reference inventory of all waste that has been or is committed to be managed at CRL. In the past, only the waste that is in storage has been effectively captured, and future predictions of wastes requiring to be managed were not available in one place. The IWP has also provided a detailed baseline plan at the current level of refinement. Waste flow maps for all identified waste streams, for the full waste life cycle complete to disposition have been constructed. The maps identify areas requiring further development, and show the complexities and inter-relationships between waste streams. Knowledge of these inter-dependencies is necessary in order to perform effective options studies for enabling

  18. Overview of Nuclear Physics at Jefferson Lab

    SciTech Connect

    McKeown, Robert D.

    2013-08-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab comprise a unique facility for experimental nuclear physics. This facility is presently being upgraded, which will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics. Further in the future, it is envisioned that the Laboratory will evolve into an electron-ion colliding beam facility.

  19. Simulating Heterogeneous Infiltration and Contaminant leaching Processes at Chalk River, Ontario

    NASA Astrophysics Data System (ADS)

    Ali, M. A.; Ireson, A. M.; Keim, D.

    2015-12-01

    A study is conducted at a waste management area in Chalk River, Ontario to characterize flow and contaminant transport with the aim of contributing to improved hydrogeological risk assessment in the context of waste management. Field monitoring has been performed to gain insights into the unsaturated zone characteristics, moisture dynamics, and contaminant transport rates. The objective is to provide quantitative estimates of surface fluxes (quantification of infiltration and evaporation) and investigations of unsaturated zone processes controlling water infiltration and spatial variability in head distributions and flow rates. One particular issue is to examine the effectiveness of the clayey soil cap installed to prevent infiltration of water into the waste repository and the top sand soil cover above the clayey layer to divert the infiltrated water laterally. The spatial variability in the unsaturated zone properties and associated effects on water flow and contaminant transport observed at the site, have led to a concerted effort to develop improved model of flow and transport based on stochastic concepts. Results obtained through the unsaturated zone model investigations are combined with the hydrogeological and geochemical components and develop predictive tools to assess the long term fate of the contaminants at the waste management site.

  20. National Labs and Nuclear Emergency Response

    NASA Astrophysics Data System (ADS)

    Budil, Kimberly

    2015-04-01

    The DOE national laboratories, and in particular the three NNSA national security laboratories, have long supported a broad suite of national nuclear security missions for the U.S. government. The capabilities, infrastructure and base of expertise developed to support the U.S. nuclear weapons stockpile have been applied to such challenges as stemming nuclear proliferation, understanding the nuclear capabilities of adversaries, and assessing and countering nuclear threats including essential support to nuclear emergency response. This talk will discuss the programs that are underway at the laboratories and the essential role that science and technology plays therein. Nuclear scientists provide expertise, fundamental understanding of nuclear materials, processes and signatures, and tools and technologies to aid in the identification and mitigation of nuclear threats as well as consequence management. This talk will also discuss the importance of direct engagement with the response community, which helps to shape research priorities and to enable development of useful tools and techniques for responders working in the field. National Labs and Nuclear Emergency Response.

  1. Spatial analysis of Carbon-14 dynamics in a wetland ecosystem (Duke Swamp, Chalk River Laboratories, Canada).

    PubMed

    Yankovich, T L; King-Sharp, K J; Carr, J; Robertson, E; Killey, R W D; Beresford, N A; Wood, M D

    2014-11-01

    A detailed survey was conducted to quantify the spatial distribution of (14)C in Sphagnum moss and underlying soil collected in Duke Swamp. This wetland environment receives (14)C via groundwater pathways from a historic radioactive Waste Management Area (WMA) on Atomic Energy Canada Limited (AECL)'s Chalk River Laboratories (CRL) site. Trends in (14)C specific activities were evaluated with distance from the sampling location with the maximum (14)C specific activity (DSS-35), which was situated adjacent to the WMA and close to an area of groundwater discharge. Based on a spatial evaluation of the data, an east-to-west (14)C gradient was found, due to the influence of the WMA on (14)C specific activities in the swamp. In addition, it was possible to identify two groups of sites, each showing significant exponential declines with distance from the groundwater source area. One of the groups showed relatively more elevated (14)C specific activities at a given distance from source, likely due to their proximity to the WMA, the location of the sub-surface plume originating from the WMA, the presence of marsh and swamp habitat types, which facilitated (14)C transport to the atmosphere, and possibly, (14)C air dispersion patterns along the eastern edge of the swamp. The other group, which had lower (14)C specific activities at a given distance from the groundwater source area, included locations that were more distant from the WMA and the sub-surface plume, and contained fen habitat, which is known to act as barrier to groundwater flow. The findings suggest that proximity to source, groundwater flow patterns and habitat physical characteristics can play an important role in the dynamics of (14)C being carried by discharging groundwater into terrestrial and wetland environments.

  2. Within-river nutrient processing in Chalk streams: The Pang and Lambourn, UK

    NASA Astrophysics Data System (ADS)

    Jarvie, Helen P.; Neal, Colin; Jürgens, Monika D.; Sutton, Elizabeth J.; Neal, Margaret; Wickham, Heather D.; Hill, Linda K.; Harman, Sarah A.; Davies, Jennifer J. L.; Warwick, Alan; Barrett, Cyril; Griffiths, Jim; Binley, Andrew; Swannack, Natalie; McIntyre, Neil

    2006-10-01

    SummaryThis work examines baseflow nutrient concentrations and loads along two rural Chalk streams, the Pang and Lambourn. Soluble reactive phosphorus (SRP) and boron (B) concentrations in these streams were heavily influenced by point-source inputs and the effects of downstream flow accretion and dilution. Unlike B (which is chemically conservative), SRP loads were also strongly influenced by in-stream processing resulting in uptake of SRP, particularly immediately downstream of sewage effluent discharges, where rates of SRP uptake were highest. For the upper River Pang, up to 80% of SRP loads were lost within 4 km downstream of Compton sewage treatment works (STW) and on the River Lambourn up to 55% of SRP loads were lost within 1.6 km downstream of East Shefford STW. In contrast, nitrate (NO 3) concentrations at sites along the Pang and Lambourn were largely controlled by groundwater inputs and plant uptake during periods of high photosynthetic activity in spring and summer and silicon (Si) by diatom uptake in April/May. There were net gains in NO 3 loads along the river reaches, as a result of volumetric increases in groundwater discharge, and, compared with SRP, the role of in-stream processing of NO 3 appeared low. Examination of SRP exchange by bed sediment and uptake of SRP into algal biofilms indicated that biofilms accounted for only a very small percentage of in-stream P-uptake, but that bed sediment SRP-exchanges had a more important control on baseflow SRP concentrations and loads. Point source P remediation at East Shefford STW, by removal of P from final effluent (P-stripping), resulted in 70-90% reductions in river-water SRP loads. After introduction of P-stripping at East Shefford STW, bed sediments immediately downstream of the STW switched from being net sinks to net sources of SRP. Our results show that, in the immediate aftermath of P-stripping, bed sediment SRP-release was responsible for a 30 μg-P l -1 rise in river-water SRP along this

  3. The implications of using large ensembles of climate scenarios for the management of river ecology in an English chalk stream

    NASA Astrophysics Data System (ADS)

    Fung, C. F.; Lopez, A.; New, M.

    2009-04-01

    Climate change is likely to impact on freshwater ecology, the delivery of regulatory commitments to ecological status and the management of water resources. It is becoming increasingly important for European environment agencies to use and develop methods to aid planning and abstraction licensing procedures and policies in the face of climate change and with the introduction of the Water Framework Directive. Studies have been carried out in the past to investigate the implications of climate change for biodiversity. However, predicting the future is fraught with uncertainty, an area which has not been dealt with in great depth in the past. This study has been undertaken to draw on the results of new methodologies to address the uncertainties inherent in modelling future climate and assess their usability for decision-making in water resources allocations specifically in considering interactions between flow and invertebrate communities The River Itchen was chosen as the case study catchment on the strength of having a long-term coupled ecological and flow dataset and having been an area of intensive study in the past. It is a chalk stream located in the south of England and a candidate Special Area of Conservation. It has also been designated a Special Site of Scientific Interest achieved due to the number of rare species, and the richness of the macro-invertebrate community in the river catchment. An ensemble of 246 transient simulations for future climate was obtained from ClimatePrediction.net which were then used to drive a rainfall-runoff model. In order to link the modelled river flow to ecology, the Lotic Invertebrate Flow Evaluation score has been used where the invertebrate community is linked to flow largely through sensitivity to water velocity and siltation, driven by flow variability at sites with fixed channel dimensions The large ensemble of climate scenarios and thereby flow and ecological indices allows the exploration of the risk of the river of

  4. Variability of dissolved CO2 in the Pang and Lambourn Chalk rivers

    NASA Astrophysics Data System (ADS)

    Griffiths, J.; Nutter, J.; Binley, A.; Crook, N.; Young, A.; Pates, J.

    2007-01-01

    This paper presents the results of a two-year field campaign to determine the spatial and temporal variability of groundwater interaction with surface waters in two Cretaceous Chalk catchments (the Pang and Lambourn) in the Upper Thames in Berkshire, UK, based on measurement of dissolved carbon dioxide (CO2). Average stream water concentrations of dissolved CO2 were up to 35 times the concentration at atmospheric equilibrium. Mean groundwater concentrations of 85 and 70 times the atmospheric equilibrium were determined from borehole water sampled in the Pang and Lambourn respectively. Diurnal and seasonal variation of in-stream concentration of dissolved CO2 is not significant enough to mask the signal from groundwater inputs.

  5. Nuclear Forensic Lab Interoperability and Criminal Investigation

    DTIC Science & Technology

    2014-08-01

    dilute in Millipore water. For zirconium elution, prepare a 0.2N oxalic solution. Weigh exact mass of oxalic acid (analytical grade) in a volumetric...CNSC Laboratory, such as the use of Omni-frit column and high purity acids , which made the separation of Ni from Co more consistent, can be found in...occurred. However, the last year of the collaboration has shown strong and effective collaboration between Canadian labs and their U.S. counterparts. One

  6. Monitoring the Geneseo Nuclear Structure Lab with VISION

    NASA Astrophysics Data System (ADS)

    Nicklaw, R.; Padalino, S.; McLean, J.

    2002-10-01

    VISION (Virtual Instrument System Information) is a LabVIEW based program designed to monitor a 2 MV Van de Graaff accelerator in the Geneseo Nuclear Structure Laboratory (GNSL). The purpose of the system is to monitor and notify the user of potentially critical situations in the lab. Main parameters of interest are the water coolant temperatures in the diffusion pumps, pressures within the vacuum chambers, and Van de Graaff operational parameters. LabVIEW reads these values and then displays them on monitors located throughout the laboratory. The user can set alarm limits on the relevant parameters, and when exceeded notifies the user verbally and visually. Recent additions to the VISION program include the water level sensor, calibration of the pressure readings, a web server application, and data logging. The VISION system is Internet accessible ^1, data from the main screen is displayed over the web for remote monitoring of the accelerator. Another useful monitoring tool is the data logger, which writes acquired data to a formatted text document at specified intervals. A future goal for VISION is to not only monitor, but to control aspects of the GNSL with LabVIEW. ^1 Webpage accessible at: http://s69n144.sci.geneseo.edu/vision.htm * Research funded in part by the United States Department of Energy

  7. Development of Molten Corium Using An Exothermic Chemical Reaction for the Molten- Fuel Moderator-Interaction Studies at Chalk River Laboratories

    SciTech Connect

    Nitheanandan, T.; Sanderson, D.B.; Kyle, G.; Farmer, M.

    2004-07-01

    Atomic Energy of Canada Limited (AECL) has partnered with Argonne National Laboratory to develop a corium thermite prototypical of Candu material and test the concept of ejecting {approx}25 kg of the molten material from a pressure tube with a driving pressure of 10 MPa. This development program has been completed and the technology transferred to AECL. Preparation for the molten-fuel moderator-interaction tests at AECL's Chalk River Laboratories is well underway. A mixture of 0.582 U/0.077 U{sub 3}O{sub 8}/0.151 Zr/0.19 CrO{sub 3} (wt%) as reactant chemicals has been demonstrated to produce a corium consisting of 0.73 UO{sub 2}/0.11 Zr/0.06 ZrO{sub 2}/0.10 Cr (wt%) at {approx}2400 deg. C. This is comparable to the target Candu specific corium of 0.9 UO{sub 2}/0.1 Zr (wt%), with limited oxidation. The peak melt temperature was confirmed from small-scale thermitic reaction tests. Several small-scale tests were completed to qualify the thermite to ensure operational safety and a quantifiable experimental outcome. The proposed molten-fuel moderator-interaction experiments at Chalk River Laboratories will consist of heating the thermite mixture inside a 1.14-m long insulated pressure tube. Once the molten material has reached the desired temperature of {approx}2400 deg. C, the pressure inside the tube will be raised to about 10 MPa, and the pressure tube will fail at a pre-machined flaw, ejecting the molten material into the surrounding tank of water. The test apparatus, instrumentation, data acquisition and control systems have been assembled, and a series of successful commissioning tests have been completed. (authors)

  8. U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada

    USGS Publications Warehouse

    Neymark, Leonid; Peterman, Zell E.; Moscati, Richard J.; Thivierge, R. H.

    2013-01-01

    As part of the Geologic Waste Management Facility feasibility study, Atomic Energy of Canada Ltd. (AECL) is evaluating the suitability of the Chalk River Laboratories (CRL) site in Ontario, situated in crystalline rock of the southwestern Grenville Province, for the possible development of an underground repository for low- and intermediate-level nuclear waste. This paper presents petrographic and trace element analyses, U–Pb zircon dating results, and Rb–Sr, U–Pb and U-series isotopic analyses of gneissic drill core samples from the deep CRG-series characterization boreholes at the CRL site. The main rock types intersected in the boreholes include hornblende–biotite (±pyroxene) gneisses of granitic to granodioritic composition, leucocratic granitic gneisses with sparse mafic minerals, and garnet-bearing gneisses with variable amounts of biotite and/or hornblende. The trace element data for whole-rock samples plot in the fields of within-plate, syn-collision, and volcanic arc-type granites in discrimination diagrams used for the tectonic interpretation of granitic rocks.Zircons separated from biotite gneiss and metagranite samples yielded SHRIMP-RG U–Pb ages of 1472 ± 14 (2σ) and 1045 ± 6 Ma, respectively, in very good agreement with widespread Early Mesoproterozoic plutonic ages and Ottawan orogeny ages in the Central Gneiss Belt. The Rb–Sr, U–Pb, and Pb–Pb whole-rock errorchron apparent ages of most of the CRL gneiss samples are consistent with zircon U–Pb age and do not indicate substantial large-scale preferential element mobility during superimposed metamorphic and water/rock interaction processes. This may confirm the integrity of the rock mass, which is a positive attribute for a potential nuclear waste repository. Most 234U/238U activity ratios (AR) in whole rock samples are within errors of the secular equilibrium value of one, indicating that the rocks have not experienced any appreciable U loss or gain within the past 1

  9. Nuclear Medicine at Berkeley Lab: From Pioneering Beginnings to Today (LBNL Summer Lecture Series)

    ScienceCinema

    Budinger, Thomas [LBNL, Center for Functional Imaging

    2016-07-12

    Summer Lecture Series 2006: Thomas Budinger, head of Berkeley Lab's Center for Functional Imaging, discusses Berkeley Lab's rich history pioneering the field of nuclear medicine, from radioisotopes to medical imaging.

  10. INL Director Explains How the National Labs Are Assisting With Japan's Nuclear Crisis

    SciTech Connect

    Grossenbacher, John

    2011-01-01

    Idaho National Laboratory's Director John Grossenbacher discusses the types of nuclear expertise and capabilities that exist within the U.S. Department of Energy's national labs to assist with the Japan nuclear crisis. He also explains how the labs will provide long-term research that will uncover lessons learned from the Fukushima nuclear plants. For more information about INL's nuclear energy research, visit http://www.facebook.com/idahonationallaboratory.

  11. INL Director Explains How the National Labs Are Assisting With Japan's Nuclear Crisis

    ScienceCinema

    Grossenbacher, John

    2016-07-12

    Idaho National Laboratory's Director John Grossenbacher discusses the types of nuclear expertise and capabilities that exist within the U.S. Department of Energy's national labs to assist with the Japan nuclear crisis. He also explains how the labs will provide long-term research that will uncover lessons learned from the Fukushima nuclear plants. For more information about INL's nuclear energy research, visit http://www.facebook.com/idahonationallaboratory.

  12. Open web system of Virtual labs for nuclear and applied physics

    NASA Astrophysics Data System (ADS)

    Saldikov, I. S.; Afanasyev, V. V.; Petrov, V. I.; Ternovykh, M. Yu

    2017-01-01

    An example of virtual lab work on unique experimental equipment is presented. The virtual lab work is software based on a model of real equipment. Virtual labs can be used for educational process in nuclear safety and analysis field. As an example it includes the virtual lab called “Experimental determination of the material parameter depending on the pitch of a uranium-water lattice”. This paper included general description of this lab. A description of a database on the support of laboratory work on unique experimental equipment which is included this work, its concept development are also presented.

  13. The water quality of the River Kennet: initial observations on a lowland chalk stream impacted by sewage inputs and phosphorus remediation.

    PubMed

    Neal, C; Jarvie, H P; Howarth, S M; Whitehead, P G; Williams, R J; Neal, M; Harrow, M; Wickham, H

    2000-05-05

    The water quality of seven sites on the upper reaches of the River Kennet round the market town of Marlborough is described and related to the introduction of phosphorus treatment of effluent from Marlborough sewage treatment works (STW). The River Kennet is mainly groundwater-fed from a Cretaceous chalk aquifer and hence the river water is calcium- and bicarbonate-bearing and has a relatively constant composition of many major water quality determinants. In-stream biological activity gives rise to marked diurnal fluctuations in pH (of approx. 0.8 units). Dissolved carbon dioxide and dissolved oxygen also show marked diurnal fluctuations. Dissolved carbon dioxide varies from approximately 10 to 70 times atmospheric pressure, indicating net release of carbon dioxide and the dominance of heterotrophic (respiratory) processes over autotrophic processes (photosynthesis). Much of the excess carbon dioxide is probably associated with carbon dioxide laden groundwater inputs and the relatively short within-stream residence times ensures only limited degassing to the atmosphere. Diurnal fluctuations in dissolved oxygen vary from approximately 20% to 200% saturation. For both dissolved carbon dioxide and dissolved oxygen, the amplitude of fluctuations is much lower during the winter period, when biological activity is at its lowest. The concentrations of soluble reactive phosphorus (SRP), total phosphorus (TP) and boron increase markedly just downstream of the sewage works as a result of this point source input. These concentrations slowly decline further downstream as additional groundwater inputs dilute the effluent further. The introduction of chemical treatment of sewage effluent for phosphorus reduction at Marlborough STW resulted in a marked decrease in within-river SRP and TP concentrations to levels approximately the same as those upstream of the STW. A comparison of SRP and boron concentrations reveals a reduction in in-stream SRP concentrations by approximately 75

  14. The Results From the First High-Pressure Melt Ejection Test Completed in the Molten Fuel Moderator Interaction Facility at Chalk River Laboratories

    SciTech Connect

    Nitheanandan, T.; Kyle, G.; O'Connor, R.; Sanderson, DB.

    2006-07-01

    A high-pressure melt ejection test using prototypical corium was conducted at Atomic Energy of Canada Limited Chalk River Laboratories. This test was planned by the CANDU Owners Group to study the potential for an energetic interaction between molten fuel and water under postulated single-channel flow-blockage events. The experiments were designed to address regulator concerns surrounding this very low probability postulated accident events in CANDU Pressurized Heavy Water Reactors. The objective of the experimental program is to determine whether a highly energetic 'steam explosion' and associated high-pressure pulse, is possible when molten material is finely fragmented as it is ejected from a fuel channel into the heavy-water moderator. The finely fragmented melt particles would transfer energy to the moderator as it is dispersed, creating a modest pressure pulse in the calandria vessel. The high-pressure melt ejection test consisted of heating up a {approx} 5 kg thermite mixture of U, U{sub 3}O{sub 8}, Zr, and CrO{sub 3} inside a 1.14-m length of insulated pressure tube. When the molten material reached the desired temperature of {approx} 2400 deg C, the pressure inside the tube was raised to 11.6 MPa, failing the pressure tube at a pre-machined flaw, and releasing the molten material into the surrounding tank of 68 deg C water. The experiment investigated the dynamic pressure history, debris size, and the effects of the material interacting with tubes representing neighbouring fuel channels. The measured mean particle size was 0.686 mm and the peak dynamic pressures were between 2.54 and 4.36 MPa, indicating that an energetic interaction between the melt and the water did not occur in the test. (authors)

  15. Early diagenesis of chalk

    NASA Astrophysics Data System (ADS)

    Zijlstra, Hans

    Smectitic clay, glauconite, pyrite, carbonate cement and silica occur concentrated in concentric zones around several m high and mm wide U-shaped burrows of Bathichnus paramoudrae, common in the Late Cretaceous Chalk of NW Europe. The minerals are authigenic and formed during bacterial metabolism and the decomposition of organic matter in 5 redox zones from aerobic near the burrow wall to anoxic in the surrounding deep sediment. The identification of the succession of redox zones and their specific mineral authigenesis contributes to a better definition of the early diagenetic conditions during deposition of bedded Chalk sequences characterised by a rhythmic vertical variation of the concentrations of the mentioned authigenic minerals.

  16. Macrophyte and periphyton dynamics in a UK Cretaceous Chalk stream: the river Kennet, a tributary of the Thames.

    PubMed

    Flyn, N J; Snook, D L; Wade, A J; Jarvie, H P

    2002-01-23

    An initial study to observe the seasonal trends and to determine the factors influencing macrophyte and periphyton growth patterns was undertaken on a representative reach of the River Kennet (UK) over a 2-year period (1998-2000). Maximum average macrophyte and average periphyton dry matter biomass recorded during the growing season were 200 and 21 g m(-2), respectively. The relationships between macrophyte and periphyton percentage cover and biomass data with physico-chemical variables were investigated. Regression analysis indicated that of the parameters measured, flow, and in the case of the dominant Ranunculus spp., solar radiation, were best able to predict macrophyte biomass and cover. The periphytic biomass within the reach was low, possibly as a result of relatively high flows and low phosphorus concentrations following the introduction of effluent treatment at the sewage works immediately upstream of the reach. Periphytic biomass was poorly correlated with the physical variables measured. This indicates that biomass is regulated by complex interactions between the physical and chemical factors, such as flow, solar radiation and phosphorus concentration. These interrelationships require further investigation.

  17. Dealing with Historical Discrepancies: The Recovery of National Research Experiment (NRX) Reactor Fuel Rods at Chalk River Laboratories (CRL) - 13324

    SciTech Connect

    Vickerd, Meggan

    2013-07-01

    Following the 1952 National Research Experiment (NRX) Reactor accident, fuel rods which had short irradiation histories were 'temporarily' buried in wooden boxes at the 'disposal grounds' during the cleanup effort. The Nuclear Legacy Liabilities Program (NLLP), funded by Natural Resources Canada (NRCan), strategically retrieves legacy waste and restores lands affected by Atomic Energy of Canada Limited (AECL) early operations. Thus under this program the recovery of still buried NRX reactor fuel rods and their relocation to modern fuel storage was identified as a priority. A suspect inventory of NRX fuels was compiled from historical records and various research activities. Site characterization in 2005 verified the physical location of the fuel rods and determined the wooden boxes they were buried in had degraded such that the fuel rods were in direct contact with the soil. The fuel rods were recovered and transferred to a modern fuel storage facility in 2007. Recovered identification tags and measured radiation fields were used to identify the inventory of these fuels. During the retrieval activity, a discrepancy was discovered between the anticipated number of fuel rods and the number found during the retrieval. A total of 32 fuel rods and cans of cut end pieces were recovered from the specified site, which was greater than the anticipated 19 fuel rods and cans. This discovery delayed the completion of the project, increased the associated costs, and required more than anticipated storage space in the modern fuel storage facility. A number of lessons learned were identified following completion of this project, the most significant of which was the potential for discrepancies within the historical records. Historical discrepancies are more likely to be resolved by comprehensive historical record searches and site characterizations. It was also recommended that a complete review of the wastes generated, and the total affected lands as a result of this historic

  18. Sister Lab Program Prospective Partner Nuclear Profile: Malaysia

    SciTech Connect

    Bissani, M; Tyson, S

    2006-12-14

    The Malaysian Deputy Prime Minister Tun Dr Ismail Abdul Rahman suggested in the early 1970s that Malaysia should have a role in the development of nuclear science and technology for peaceful purposes. Accordingly, the Center for the Application of Nuclear Energy (CRANE) was established, with a focus on the development of a scientific and technical pool critical to a national nuclear power program. The Malaysian Cabinet next established the Tun Ismail Atomic Research Center (TIARC) under the Ministry of Science, Technology and the Environment on 19 September 1972, at a site in Bangi, about 35 km south of Kuala Lampur. On 28 June 1982, the PUSPATI reactor, a 1-MW TRIGA MK-II research reactor, first reached criticality. On 10 August 1994, TIARC was officially renamed as the Malaysian Institute for Nuclear Technology Research (MINT). In addition to radioisotope production and neutron radiography conducted at the PUSPATI research reactor, MINT also supports numerous programs employing nuclear technology for medicine, agriculture and industry, and has been involved in both bilateral and multilateral technical cooperation to extend its capabilities. As an energy exporting country, Malaysia has felt little incentive to develop a nuclear energy program, and high level opposition within the government discouraged it further. A recent statement by Malaysia's Science, Technology and Innovation Minister supported this view, indicating that only a near-catastrophic jump in world oil prices might change the government's view. However, the rate at which Malaysia is using its natural gas and oil reserves is expected to force it to reassess the role of nuclear energy in the near future. In addition, the government does intend to construct a radioactive waste repository to dispose of naturally occurring radioactive materials (extracted during tin mining, in particular). Also, Malaysia's growing economy could encourage expansion in Malaysia's existing nuclear-applications programs

  19. Sister Lab Program Prospective Partner Nuclear Profile: Indonesia

    SciTech Connect

    Bissani, M; Tyson, S

    2006-12-14

    Indonesia has participated in cooperative technical programs with the IAEA since 1957, and has cooperated with regional partners in all of the traditional areas where nuclear science is employed: in medicine, public health (such as insect control and eradication programs), agriculture (e.g. development of improved varieties of rice), and the gas and oil industries. Recently, Indonesia has contributed significantly to the Reduced Enrichment Research and Training Reactor (RERTR) Program by conducting experiments to confirm the feasibility of Mo-99 production using high-density low enriched uranium (LEU) fuel, a primary goal of the RERTR Program. Indonesia's first research reactor, the TRIGA Mark II at Bandung, began operation in 1964 at 250 kW and was subsequently upgraded in 1971 to 1 MW and further upgraded in 2000 to 2 MW. This reactor was joined by another TRIGA Mark II, the 100-kW Kartini-PPNY at Yogyakarta, in 1979, and by the 30-MW G.A. Siwabessy multipurpose reactor in Serpong, which achieved criticality in July 1983. A 10-MW radioisotope production reactor, to be called the RPI-10, also was proposed for construction at Serpong in the late 1990s, but the project apparently was not carried out. In the five decades since its nuclear research program began, Indonesia has trained a cadre of scientific and technical staff who not only operate and conduct research with the current facilities, but also represent the nucleus of a skilled labor pool to support development of a nuclear power program. Although Indonesia's previous on-again, off-again consideration of nuclear power has not gotten very far in the past, it now appears that Indonesia again is giving serious consideration to beginning a national nuclear energy program. In June 2006, Research and Technology Minister Kusmayanto Kadiman said that his ministry was currently putting the necessary procedures in place to speed up the project to acquire a nuclear power plant, indicating that, ''We will need around

  20. Evaluation of distribution and sources of sewage molecular marker (LABs) in selected rivers and estuaries of Peninsular Malaysia.

    PubMed

    Magam, Sami M; Zakaria, Mohamad Pauzi; Halimoon, Normala; Aris, Ahmad Zaharin; Kannan, Narayanan; Masood, Najat; Mustafa, Shuhaimi; Alkhadher, Sadeq; Keshavarzifard, Mehrzad; Vaezzadeh, Vahab; Sani, Muhamad S A; Latif, Mohd Talib

    2016-03-01

    This is the first extensive report on linear alkylbenzenes (LABs) as sewage molecular markers in surface sediments collected from the Perlis, Kedah, Merbok, Prai, and Perak Rivers and Estuaries in the west of Peninsular Malaysia. Sediment samples were extracted, fractionated, and analyzed using gas chromatography mass spectrometry (GC-MS). The concentrations of total LABs ranged from 68 to 154 (Perlis River), 103 to 314 (Kedah River), 242 to 1062 (Merbok River), 1985 to 2910 (Prai River), and 217 to 329 ng g(-1) (Perak River) dry weight (dw). The highest levels of LABs were found at PI3 (Prai Estuary) due to the rapid industrialization and population growth in this region, while the lowest concentrations of LABs were found at PS1 (upstream of Perlis River). The LABs ratio of internal to external isomers (I/E) in this study ranged from 0.56 at KH1 (upstream of Kedah River) to 1.35 at MK3 (Merbok Estuary) indicating that the rivers receive raw sewage and primary treatment effluents in the study area. In general, the results of this paper highlighted the necessity of continuation of water treatment system improvement in Malaysia.

  1. Chalk Murals and Great Artists.

    ERIC Educational Resources Information Center

    Schweizer, Kay

    2000-01-01

    Discusses the Annual Chalk Mural project done by the members of the National Art Honor Society at the Sacramento County Day School. Discusses the tradition of the annual project and the planning and research involved. Focuses on the 7th Annual Chalk Mural featuring Wayne Thiebaud. (CMK)

  2. Chalk Murals and Great Artists.

    ERIC Educational Resources Information Center

    Schweizer, Kay

    2000-01-01

    Discusses the Annual Chalk Mural project done by the members of the National Art Honor Society at the Sacramento County Day School. Discusses the tradition of the annual project and the planning and research involved. Focuses on the 7th Annual Chalk Mural featuring Wayne Thiebaud. (CMK)

  3. StreamLab: Full-scale Experiments in River Science (Invited)

    NASA Astrophysics Data System (ADS)

    Wilcock, P.

    2009-12-01

    Experimental studies of river processes can provide control of essential variables and support detailed technical measurements. Practical constraints often drive experiments toward a reduced scale, but essential features of natural systems are difficult or impossible to scale. These include processes involving aquatic organisms and their interactions with their physical surroundings, as well as features such bed forms and channel pattern that arise from interactions among processes operating across a range of spatial scales. A sound understanding of both local mechanisms and broader interactions is needed to develop predictive models in river science. The solution is to conduct experiments at full scale while maintaining experimental control and using instrumentation that can resolve both local and full-scale processes. Important advances in automated measurement technology play a key role in making such an approach feasible, but considerable conceptual, technical, and organizational challenges remain to be addressed. This paper reports on some of these challenges and opportunities based on experience with StreamLab: a program of full-scale experiments on linked physical/chemical/biological processes initiated by The National Center for Earth-surface Dynamics (NCED) and the St. Anthony Falls Laboratory (SAFL). The essential features of StreamLab are an explicit multi-disciplinary focus, experimental control at the field scale, and the use of advanced technology to support detailed observations typical of small-scale lab experiments. StreamLab has three elements: Indoor StreamLab (ISL), Outdoor StreamLab (OSL), and Virtual StreamLab (VSL). ISL is based on a large rectangular laboratory channel and includes smaller facilities that can be used to isolate individual mechanisms. OSL includes two basins in which full-scale channels can develop with natural riparian vegetation and in-stream biota. VSL extends the StreamLab concept to full-scale, turbulence

  4. Sister Lab Program Prospective Partner Nuclear Profile: Vietnam

    SciTech Connect

    Bissani, M; Tyson, S

    2006-12-14

    Vietnam's nuclear program began in the 1960s with the installation at Dalat of a 250 kW TRIGA Mk-II research reactor under the U.S. Atoms for Peace Program. The reactor was shut down and its core removed only a few years later, and the nuclear research program was suspended until after the end of the civil war in the late 1970s. The Soviet Union assisted Vietnam in restoring the Dalat reactor to an operational status in 1984, trained a cadre of scientific and technical staff in its operation, and contributed to the development of nuclear science for the medical and agricultural sectors. In the agricultural area in particular, Vietnamese experts have been very successful in developing mutant strains of rice, and continue to work with the IAEA to yield strains that have a shorter growing period, increased resistance to disease, and other desirable characteristics. Rice has always been the main crop in Vietnam, but technical cooperation with the IAEA and other states has enabled the country to become one of the top rice producers in the world, exporting much of its annual crop to over two dozen countries annually. More recently, Vietnam's government has shown increasing interest in developing a civil nuclear program to supplement its fossil fuel and other energy resources. Projections from a variety of open sources, ranging from the IAEA, the U.S. Department of Energy's Energy Information Administration (EIA), the Vietnamese government, energy corporations, and think tanks all predict a massive increase in energy consumption--especially electricity--within Vietnam and the region as a whole. This growth in consumption will require a corresponding increase in energy production, which in Vietnam is currently satisfied mainly by fossil fuels (coal) and renewable energy (hydropower and biomass); Vietnam has a refining capacity of about 800 barrels/day. Most of its crude oil is exported to generate export income, and is not used to generate electricity. Although Vietnam is

  5. PAH occurrence in chalk river systems from the Jura region (France). Pertinence of suspended particulate matter and sediment as matrices for river quality monitoring.

    PubMed

    Chiffre, Axelle; Degiorgi, François; Morin-Crini, Nadia; Bolard, Audrey; Chanez, Etienne; Badot, Pierre-Marie

    2015-11-01

    This study investigates the variations of polycyclic aromatic hydrocarbon (PAH) levels in surface water, suspended particulate matter (SPM) and sediment upstream and downstream of the discharges of two wastewater treatment plant (WWTP) effluents. Relationships between the levels of PAHs in these different matrices were also investigated. The sum of 16 US EPA PAHs ranged from 73.5 to 728.0 ng L(-1) in surface water and from 85.4 to 313.1 ng L(-1) in effluent. In SPM and sediment, ∑16PAHs ranged from 749.6 to 2,463 μg kg(-1) and from 690.7 μg kg(-1) to 3,625.6 μg kg(-1), respectively. Investigations performed upstream and downstream of both studied WWTPs showed that WWTP discharges may contribute to the overall PAH contaminations in the Loue and the Doubs rivers. Comparison between gammarid populations upstream and downstream of WWTP discharge showed that biota was impacted by the WWTP effluents. When based only on surface water samples, the assessment of freshwater quality did not provide evidence for a marked PAH contamination in either of the rivers studied. However, using SPM and sediment samples, we found PAH contents exceeding sediment quality guidelines. We conclude that sediment and SPM are relevant matrices to assess overall PAH contamination in aquatic ecosystems. Furthermore, we found a positive linear correlation between PAH contents of SPM and sediment, showing that SPM represents an integrating matrix which is able to provide meaningful data about the overall contamination over a given time span.

  6. Ion source modeling and design at PRIME Lab

    NASA Astrophysics Data System (ADS)

    Jackson, George S.; Elmore, David; Caffee, Marc; Mueller, Kenneth A.; De Bonte, Bob; Muzikar, Paul; Alexander, Brad

    2004-08-01

    The design and ion optics of a new high intensity cesium ion source and sample changer being built at PRIME Lab will be discussed. The ion source is based on the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory design and the sample changer is based on a sample changer developed at Chalk River Nuclear Laboratories in Canada. The ion optics are being modeled using Simion 7.0, which iteratively solves Laplaces' equation. Simion 7.0 does not require cylindrical symmetry so the effects of non-symmetric components, in particular the sample insertion rod and immersion lens can be explored. Other aspects that are being modeled are small shifts in the position of the ionizer as it is heated; shape of the immersion lens; distance from the cathode to the immersion lens; distance from the ionizer to the cathode; the effect of voltage (relative to the cathode) on the immersion lens; the shape of the cathode; and space charge.

  7. Less chalk more action

    NASA Astrophysics Data System (ADS)

    Mitriceski Andelkovic, Bojana; Jovic, Sladjana

    2016-04-01

    Less chalk more action Education should not be a mechanical system that operates according to the principles of the orders and implementation. Education should respect the basic laws of the develop and progress. Curiosity is the engine of achievement and children spontaneously and happily learn only if they get interested, if teacher wake up and stimulate their creativity and individuality. We would like to present classes that are realized as thematic teaching with several subjects involved: chemistry, geography, math, art and biology. Classes were organized for students at age from 10 to 13 years, every month during autumn and winter 2015. Better students identified themselves as teachers and presented peer education .Teachers were monitoring the process of teaching and help to develop links between younger and older students, where older students were educators to younger students. Also one student with special needs was involved in this activities and was supported by other students during the workshops The benefit from this project will be represented with evaluation marks. Evaluation table shows that group of ten students(age 10 to13 years) which are selected in October as children with lack of motivation for learning, got better marks, at the end of January , then they had it in the beginning of the semester.

  8. ChalkBoard: Mapping Functions to Polygons

    NASA Astrophysics Data System (ADS)

    Matlage, Kevin; Gill, Andy

    ChalkBoard is a domain specific language for describing images. The ChalkBoard language is uncompromisingly functional and encourages the use of modern functional idioms. ChalkBoard uses off-the-shelf graphics cards to speed up rendering of functional descriptions. In this paper, we describe the design of the core ChalkBoard language, and the architecture of our static image generation accelerator.

  9. New progresses in the high frequency acquisition of stream chemical data in hydrological observatories: the Orgeval River lab

    NASA Astrophysics Data System (ADS)

    Floury, Paul; Gaillardet, Jerome; Tallec, Gaelle; Ansard, Patrick; Blanchoin, Arnaud; Gayer, Eric; Bouchez, Julien; Gorge, Caroline

    2017-04-01

    River chemistry is a messenger revealing the processes and their timescales at the catchment scale. In establishing a network of hydrological sites, river chemistry is one of the best "windows" to understand the reactive-transport processes at play within the critical zone at the catchment scale. However, our understanding of hydrological and chemical processes at a catchment scale is limited by our capacity to record the full breadth of the information carried by river chemistry, both in terms of sampling frequency and in precision. Here, we present the proof of concept of a new system of water quality monitoring that we called "the River Lab" (RL), based on the idea of installing permanently the laboratory instruments to the field. Confined in a bungalow next to the river, this set of instruments performs an analysis at a 40-minutes frequency of all major dissolved species (Na, K, Mg, Ca, Cl, SO4, NO3) through continuous sampling and filtration of the river water and using ion chromatographs. The River Lab was deployed in the Orgeval hydrological Observatory, part of the OZCAR research RIs, France, for more than one year. Results show that the River Lab is able to capture the long-term fine chemical variations with no drift and a precision a significantly better than the precision conventionally achieved in the laboratory. The River Lab is thus providing unprecedented, high-resolution, high precision measurements and is opening new perspectives for understanding critical zone eco-hydrological processes and biogeochemical cycles. It also offer a solution for operational agencies to monitor the water quality in quasi real-time as it is offering an integrated response to the different anthropogenic forcings

  10. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Chalk Hill. 9.52 Section 9... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved maps...

  11. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chalk Hill. 9.52 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved maps...

  12. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Chalk Hill. 9.52 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved maps...

  13. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Chalk Hill. 9.52 Section 9... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved maps...

  14. 27 CFR 9.52 - Chalk Hill.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Chalk Hill. 9.52 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.52 Chalk Hill. (a) Name. The name of the viticultural area described in this section is “Chalk Hill.” (b) Approved maps...

  15. Groundwater Flooding in the Chalk of England

    NASA Astrophysics Data System (ADS)

    Vounaki, T.; Hughes, A.; Peach, D.; Jackson, C.

    2009-12-01

    During the winters of 2001 and 2003 extensive long duration flooding occurred in the valleys of the Chalk downlands in England. Chalk streams of the downlands are characterized by seasonally driven ephemeral “bourne” behavior and flooding often occurred further up-stream than typical in these dry valleys. Detailed studies in the Rivers Pang and Lambourn have included analysis of flow records and borehole hydrographs which have revealed that the groundwater flooding mechanisms are intimately related with antecedent rainfall and high groundwater conditions, leading to the development of sustained groundwater mounding on the stream interfluves. Data concerning the location of unusual spring flow and ponding water has been gathered from aerial photography and surveys by regulatory authorities, but much valuable information was obtained from a questionnaire sent to farmers in the area. The location of flooding is influenced by the topography and local geology. Two mechanisms are prevalent in different parts of the catchments. In the downstream areas, flow is generated by the groundwater level reaching the ground surface in an expected manner, but in other areas the presence of hard grounds and high transmissivity horizons causes spring generation on the sides of normally dry valleys.

  16. Sewage effluent clean-up reduces phosphorus but not phytoplankton in lowland chalk stream (River Kennet, UK) impacted by water mixing from adjacent canal.

    PubMed

    Neal, Colin; Martin, Ellie; Neal, Margaret; Hallett, John; Wickham, Heather D; Harman, Sarah A; Armstrong, Linda K; Bowes, Mike J; Wade, Andrew J; Keay, David

    2010-10-15

    Information is provided on phosphorus in the River Kennet and the adjacent Kennet and Avon Canal in southern England to assess their interactions and the changes following phosphorus reductions in sewage treatment work (STW) effluent inputs. A step reduction in soluble reactive phosphorus (SRP) concentration within the effluent (5 to 13 fold) was observed from several STWs discharging to the river in the mid-2000s. This translated to over halving of SRP concentrations within the lower Kennet. Lower Kennet SRP concentrations change from being highest under base-flow to highest under storm-flow conditions. This represented a major shift from direct effluent inputs to a within-catchment source dominated system characteristic of the upper part to the catchment. Average SRP concentrations in the lower Kennet reduced over time towards the target for good water quality. Critically, there was no corresponding reduction in chlorophyll-a concentration, the waters remaining eutrophic when set against standards for lakes. Following the up gradient input of the main water and SRP source (Wilton Water), SRP concentrations in the canal reduced down gradient to below detection limits at times near its junction with the Kennet downstream. However, chlorophyll concentrations in the canal were in an order of magnitude higher than in the river. This probably resulted from long water residence times and higher temperatures promoting progressive algal and suspended sediment generations that consumed SRP. The canal acted as a point source for sediment, algae and total phosphorus to the river especially during the summer months when boat traffic disturbed the canal's bottom sediments and the locks were being regularly opened. The short-term dynamics of this transfer was complex. For the canal and the supply source at Wilton Water, conditions remained hypertrophic when set against standards for lakes even when SRP concentrations were extremely low.

  17. 75 FR 69710 - Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant Environmental Assessment and Finding of No... (the licensee), for operation of the Crystal River Unit 3 Nuclear Generating Plant (CR- 3), located in...

  18. 76 FR 5216 - Florida Power Corporation, Crystal River Unit 3 Nuclear Generating Plant; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ... COMMISSION Florida Power Corporation, Crystal River Unit 3 Nuclear Generating Plant; Exemption 1.0 Background... authorizes operation of the Crystal River ] Unit 3 Nuclear Generating Plant (Crystal River). The license... under 10 CFR 55.11 from the schedule requirements of 10 CFR 55.59. Specifically for Crystal River, the...

  19. 77 FR 1743 - Facility Operating License Amendment From Florida Power Corporation, Crystal River Nuclear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... COMMISSION Facility Operating License Amendment From Florida Power Corporation, Crystal River Nuclear... Florida Power Corporation for operation of the Crystal River Nuclear Generating Plant, Unit 3. The proposed amendment would increase the licensed core power level for Crystal River Nuclear Generating Plant...

  20. Chalk Line Mill, Anniston, AL

    EPA Pesticide Factsheets

    The Chalk Line Mill property was the site of a textile mill which operated from 1887 until 1994. Demolition activities in 2004 removed most of the structures on-site, but also left large, unsightly piles of debris scattered across this 14-acre property. The City applied for and received a $200,000 Brownfields cleanup grant in 2007 to address contamination on the property and the Appalachian Regional Commission provided an additional $150,000 in funding.

  1. A novel representation of chalk hydrology in a land surface model

    NASA Astrophysics Data System (ADS)

    Rahman, Mostaquimur; Rosolem, Rafael

    2016-04-01

    Unconfined chalk aquifers contain a significant portion of water in the United Kingdom. In order to optimize the assessment and management practices of water resources in the region, modelling and monitoring of soil moisture in the unsaturated zone of the chalk aquifers are of utmost importance. However, efficient simulation of soil moisture in such aquifers is difficult mainly due to the fractured nature of chalk, which creates high-velocity preferential flow paths in the unsaturated zone. In this study, the Joint UK Land Environment Simulator (JULES) is applied on a study area encompassing the Kennet catchment in Southern England. The fluxes and states of the coupled water and energy cycles are simulated for 10 consecutive years (2001-2010). We hypothesize that explicit representation for the soil-chalk layers and the inclusion of preferential flow in the fractured chalk aquifers improves the reproduction of the hydrological processes in JULES. In order to test this hypothesis, we propose a new parametrization for preferential flow in JULES. This parametrization explicitly describes the flow of water in soil matrices and preferential flow paths using a simplified approach which can be beneficial for large-scale hydrometeorological applications. We also define the overlaying soil properties obtained from the Harmonized World Soil Database (HWSD) in the model. Our simulation results are compared across spatial scales with measured soil moisture and river discharge, indicating the importance of accounting for the physical properties of the medium while simulating hydrological processes in the chalk aquifers.

  2. Reprocessing of nuclear fuels at the Savannah River Plant

    SciTech Connect

    Gray, L.W.

    1986-10-04

    For more than 30 years, the Savannah River Plant (SRP) has been a major supplier of nuclear materials such as plutonium-239 and tritium-3 for nuclear and thermonuclear weapons, plutonium-238 for space exploration, and isotopes of americium, curium, and californium for use in the nuclear research community. SRP is a complete nuclear park, providing most of the processes in the nuclear fuel cycle. Key processes involve fabrication and cladding of the nuclear fuel, target, and control assemblies; rework of heavy water for use as reactor moderator; reactor loading, operation, and unloading; chemical recovery of the reactor transmutation products and spent fuels; and management of the gaseous, liquid, and solid nuclear and chemical wastes; plus a host of support operations. The site's history and the key processes from fabrication of reactor fuels and targets to finishing of virgin plutonium for use in the nuclear weapons complex are reviewed. Emphasis has been given to the chemistry of the recovery and purification of weapons grade plutonium from irradiated reactor targets.

  3. Pointing with Power or Creating with Chalk

    ERIC Educational Resources Information Center

    Rudow, Sasha R.; Finck, Joseph E.

    2015-01-01

    This study examines the attitudes of students on the use of PowerPoint and chalk/white boards in college science lecture classes. Students were asked to complete a survey regarding their experiences with PowerPoint and chalk/white boards in their science classes. Both multiple-choice and short answer questions were used. The multiple-choice…

  4. Karstic behaviour of groundwater in the English Chalk

    NASA Astrophysics Data System (ADS)

    Maurice, L. D.; Atkinson, T. C.; Barker, J. A.; Bloomfield, J. P.; Farrant, A. R.; Williams, A. T.

    2006-10-01

    SummaryAlthough the Chalk is only weakly karstified, tracer testing from stream sinks has demonstrated groundwater flow velocities comparable to those observed in highly karstic aquifers. Field survey of surface karst features in the catchments of the Pang and Lambourn rivers in southern England demonstrates the importance of overlying and adjacent Palaeogene strata in the development of karst features. Tracer techniques employed within the catchments enable further characterisation of the range and connectivity of solutional voids in this area of the Chalk, and allow assessment of the relative importance of different mechanisms of contaminant attenuation. Quantitative tracer test results suggest that groundwater flow may be through a complex combination of small conduits, typically 10-1000 mm in diameter, and more laterally extensive fissures with apertures of 1-50 mm. Evidence of connectivity between conduits and fissures suggest that in areas of the Chalk with rapid groundwater flow, fissures supplying abstraction boreholes may be connected to karst conduit networks with low potential for contaminant attenuation.

  5. 75 FR 70953 - Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... COMMISSION Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant; Exemption 1.0...-72, which authorizes operation of the Crystal River Unit 3 Nuclear Generating Plant (CR-3). The... and discussed in the June 4, 2009, letter. Crystal River Schedule Exemption Request The licensee...

  6. 75 FR 16518 - Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... COMMISSION Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant; Exemption 1.0...-72 that authorizes operation of the Crystal River Unit 3 Nuclear Generating Plant (CR-3). The license... approach set forth by the Commission and discussed in the June 4, 2009, letter. Crystal River Schedule...

  7. 76 FR 53972 - Florida Power Corporation, Crystal River Unit No. 3 Nuclear Generating Plant; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Florida Power Corporation, Crystal River Unit No. 3 Nuclear Generating Plant; Notice of... Facility Operating License No. DPR-72 for Crystal River Unit 3 Nuclear generating Plant (CR-3), currently...

  8. Cretaceous shelf-sea chalk deposits

    SciTech Connect

    Hattin, D.E.

    1988-01-01

    The word ''chalk'' is linked etymologically to the Cretaceous, but chalky facies neither dominate that system nor are confined to it. As used commonly, the term ''chalk'' refers to a variety of marine limestone that is white to light gray very fine grained, soft and friable, porous, and composed predominantly of calcitic skeletal remains, especially those derived from coccolithophores. No simple definition suffices to embrace all Cretaceous chalks, which include sandy, marly, shelly, phospatic, glauconitic, dolomitic, pyritic and organic-rich lithotypes. Most of the world's exposed Cretaceous chalk deposits were formed at shelf depths rather than in the deep sea. Cretaceous shelf-sea chalks are developed most extensively in northern Europe, the U.S. Gulf Coastal Plain and Western Interior, and the Middle East, with lesser occurrences alo in Australia. Most Cretaceous shelf-sea chalks formed in the temperature zones, and in relatively deep water. Cretaceous chalks deposited on well-oxygenated sea floors are bioturbated and massive where deficient in terrigenous detritus, or bioturbated and rhythmically interbedded with argillaceous units where influx of terrigenous detritus varied systematically with climate changes. Accumulation of sufficient pelagic mud to form vast deposits of Cretaceous shelf-sea chalk required (1) sustained high productivity of calareous plankton, (2) extensive development of stable shelf and continental platform environments, (3) highstands of seal level, (4) deficiency of aragonitic skeletal material in chalk-forming sediments, and (5) low rates of terrigenous detrital influx. These conditions were met at different times in different places, even within the same general region.

  9. ALARA Overview System at Crystal River Unit 3 Nuclear Station.

    PubMed

    Kline, K B; Cope, W B

    1995-08-01

    During the Spring of 1994 the Health Physics Department at Florida Power Company used video and audio equipment to support remote health physics coverage for their Crystal River Unit 3 refueling outage (Refuel 9). The system consisted of eight cameras with audio interface linked to a control center located in a low-dose area. The system allowed health physics personnel to monitor steam generator and refueling activities with minimum exposure in high-dose areas, cutting by half the dose from the previous outage. B&W Nuclear Technologies provided complete setup, maintenance and tear-down, as well as assuming responsibilities for contaminated video and audio equipment.

  10. Nuclear Material Processing at the Savannah River Site

    SciTech Connect

    Severynse, T.F.

    1998-07-01

    Plutonium production for national defense began at Savannah River in the mid-1950s, following construction of production reactors and separations facilities. Following the successful completion of its production mission, the site`s nuclear material processing facilities continue to operate to perform stabilization of excess materials and potentially support the disposition of these materials. A number of restoration and productivity improvement projects implemented in the 1980s, totaling nearly a billion dollars, have resulted in these facilities representing the most modern and only remaining operating large-scale processing facilities in the DOE Complex. Together with the Site`s extensive nuclear infrastructure, and integrated waste management system, SRS is the only DOE site with the capability and mission of ongoing processing operations.

  11. Distribution and dissipation pathways of nonylphenol polyethoxylates in the Yellow River: Site investigation and lab-scale studies.

    PubMed

    Wang, Lei; Wu, Yinghong; Sun, Hongwen; Xu, Jian; Dai, Shugui

    2006-09-01

    Spatial distribution of nonylphenol polyethoxylates (NPEOs) and nonylphenol (NP) was investigated in a field study in Lanzhou Reach of the Yellow River. NPEOs and their metabolites were found in the river, with the maximum dissolved concentrations of 6.38 nmol/L for NPEOs, 0.19 nmol/L for nonylphenol ethoxy acetic acids (NPECs) and 0.79 nmol/L for NP, respectively. The maximum concentrations in the sediment and suspended particle samples were 1.50 and 5.09 nmol/g for NPEOs and NP, respectively. The effects of particles, light and microorganism on the dissipation of NPEOs in the river water were investigated based on lab-scale experiments. When natural particles were removed, 72% and 22% degradation of NPEOs were achieved at 120 h in non-sterile and sterile conditions with light, respectively. Different concentrations of NPECs were also observed in these experiments. When suspended particle matters (SPMs) were present, about 38-50% of NPEOs were sorbed to the particulate phase in only 1 h. As a result, the degradation of NPEOs and production of NPECs were inhibited. However, the combined sorption and degradation in the presence of SPMs resulted in lower dissolved NPEO concentrations than those in the absence of SPMs. Biodegradation was the most important pathway for NPEOs degradation in the river water, while NPECs seemed to be produced through both biological and abiological pathways.

  12. Persistence of fecal indicator bacteria in sediment of an oligotrophic river: comparing large and lab-scale flume systems.

    PubMed

    Walters, Evelyn; Kätzl, Korbinian; Schwarzwälder, Kordula; Rutschmann, Peter; Müller, Elisabeth; Horn, Harald

    2014-09-15

    In this study, both a lab and a large-scale flume system were used to investigate the survival of fecal indicator bacteria (FIB) in bed sediments of an alpine oligotrophic river. To determine the influence of substratum on persistence, survival within 3-cm-deep substratum cages versus on thin, biofilm-covered ceramic tiles was tested. Moreover, the impact of bed shear stress on survival in bed sediments was explored. It was seen that in the lab-scale flume having a very low bed shear stress (0.3 N m(-2)), E. coli and enterococci survival in 3-cm-deep substratum cages was nearly the same as in a thin biofilm (200 μm). However, in the large-scale flume system characterized by a bed shear stress of 9 N m(-2), the added protection of the deeper substratum cages promoted considerably longer survival of E. coli and enterococci than the thin biofilm. Additionally, the FIB removal mechanisms in the two flume systems varied. At the lab-scale, enterococci was seen to persist twice as long as E. coli, while in the large-scale flume the two FIB were removed at the same rate. A comparison of qPCR analyses performed in both flumes suggests that bed sediment erosion and the influence of grazers/predators were responsible for FIB removal from the sediments in the large-scale flume, whereas in the lab flume FIB inactivation caused removal. These results indicate that hydraulic parameters such as bed shear stress as well as the presence of macroinvertebrates in a system are both important factors to consider when designing flumes as they can significantly impact FIB persistence in sediments of fast-flowing, alpine streams.

  13. Characterization and closure of the Met Lab Carolina Bay at the Savannah River site, Aiken, South Carolina

    SciTech Connect

    Jerome, K.M.; Frazier, W.L.; Haselow, L.A.; Voss, L.

    1993-07-01

    The Met Lab Carolina Bay is subject to Subtitle C of RCRA and CERCLA requirements. Located in the northwestern section of the Savannah River Site, the Met Lab Carolina Bay is a marshy, oval-shaped natural depression covering approximately six acres. The Carolina Bay received wastes from three sources: the Met Lab Basin A-007 drainage outfall, the A-Area coal-fire power plant A-008 drainage outfall and the A/M-Area vehicle maintenance parking lot stormwater runoff A-009 outfall. Two characterization efforts conducted in 1988/89 and 1991 indicate the presence of metals in the sediments and soils of the bay. The greatest concentrations of the metals and organics being in the north-central portion of the bay. The metals and organics were primarily associated with surface sediments and the organic-rich soil layer to a depth of about two feet. Conclusions from the Human Health Baseline Risk indicate the future on-unit resident exposure to sediments and soil poses an unacceptable level of risk to human health. However, the assumptions built into the calculations lead to conservative human health risk findings. A qualitative Ecological Risk Assessment was performed on the Carolina Bay. This ecological assessment, based on historical and existing sampling data, was found to be insufficient to make a definitive decision on the contaminants` effects on the ecology of the bay. The proposed action for the Carolina Bay is to conduct an ecological characterization. It appears that the ecological risks will be in the driving factor in determining the remedial action for the Met Lab Carolina Bay.

  14. 75 FR 13320 - Florida Power Corporation, et al., Crystal River Unit 3 Nuclear Generating Plant; Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Florida Power Corporation, et al., Crystal River Unit 3 Nuclear Generating Plant; Environmental.... DPR 72 issued to Florida Power Corporation (the licensee), for operation of the Crystal River Unit 3...

  15. The spatial distribution of groundwater flooding in a chalk catchment in southern England

    NASA Astrophysics Data System (ADS)

    Finch, J. W.; Bradford, R. B.; Hudson, J. A.

    2004-04-01

    Groundwater flooding occurred in the upper parts of many chalk rivers in the UK during the exceptionally wet winter of 2000-01. This provided a rare opportunity to investigate the spatial distribution of groundwater discharge and flooding along the normally dry intermittent headwaters of a chalk catchment. The extent of flooding along the River Pang, upstream of the seasonal head, was mapped using aerial photography, and point measurements of flow and water temperature were used to identify the contributing reaches of the river. The results are discussed in the context of the geological and groundwater conditions. The occurrence of flooding can largely be explained by the regional groundwater flow directions, but increased flow in some locations may be as a result of preferential groundwater flow along lines of geological structure. Published by John Wiley & Sons, Ltd.

  16. 78 FR 79709 - Duke Energy Florida, Inc., Crystal River Unit 3 Nuclear Generating Plant Post-Shutdown...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ... Florida, Inc., Crystal River Unit 3 Nuclear Generating Plant Post-Shutdown Decommissioning Activities... System (ADAMS) Accession No. ML13340A009), for the Crystal River Unit 3 Nuclear Generating Plant (CR-3..., January 16, 2014, from 7 p.m. until 9 p.m., EST, at the Crystal River Nuclear Plant Training Center...

  17. 76 FR 70866 - Expansions of the Russian River Valley and Northern Sonoma Viticultural Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... northeastern corner, the Chalk Hill viticultural area (27 CFR 9.52), and in the southwest, the Green Valley of... located entirely within the Northern Sonoma viticultural area as follows: Chalk Hill, Alexander Valley..., Russian River Valley, and Knights Valley. The Sonoma County Green Valley and Chalk Hill areas are each...

  18. Microdeformation and subcritical cracking in chalk

    NASA Astrophysics Data System (ADS)

    Bergsaker, Anne; Dysthe, Dag Kristian

    2016-04-01

    Deformation processes in chalks, both in relation to changing pore fluids and stress conditions has been of great interest as chalk is an important reservoir rock for both hydrocarbons and ground water. Lately it has also gained interest as a potential reservoir rock for captured CO2. Chalks are composed of large amounts of biogenic calcite grains, the skeletal debris of marine microorganisms. Its deformation is highly time and stress dependent, and governed by a transition from distributed to localized deformation at the onset of yield, affected by mechanisms such as subcritical crack growth and pore collapse. We present a microdeformation rig which makes use of thermal expansion as a means of subjecting small samples to strictly controlled tensile stresses. High resolution imaging provides resolutions down to 0.5 micrometers, enabling study of pore scale processes during slow deformation. Examples of localized and distributed deformation are presented.

  19. USED NUCLEAR MATERIALS AT SAVANNAH RIVER SITE: ASSET OR WASTE?

    SciTech Connect

    Magoulas, V.

    2013-06-03

    The nuclear industry, both in the commercial and the government sectors, has generated large quantities of material that span the spectrum of usefulness, from highly valuable (“assets”) to worthless (“wastes”). In many cases, the decision parameters are clear. Transuranic waste and high level waste, for example, have no value, and is either in a final disposition path today, or – in the case of high level waste – awaiting a policy decision about final disposition. Other materials, though discardable, have intrinsic scientific or market value that may be hidden by the complexity, hazard, or cost of recovery. An informed decision process should acknowledge the asset value, or lack of value, of the complete inventory of materials, and the structure necessary to implement the range of possible options. It is important that informed decisions are made about the asset value for the variety of nuclear materials available. For example, there is a significant quantity of spent fuel available for recycle (an estimated $4 billion value in the Savannah River Site’s (SRS) L area alone); in fact, SRS has already blended down more than 300 metric tons of uranium for commercial reactor use. Over 34 metric tons of surplus plutonium is also on a path to be used as commercial fuel. There are other radiological materials that are routinely handled at the site in large quantities that should be viewed as strategically important and / or commercially viable. In some cases, these materials are irreplaceable domestically, and failure to consider their recovery could jeopardize our technological leadership or national defense. The inventories of nuclear materials at SRS that have been characterized as “waste” include isotopes of plutonium, uranium, americium, and helium. Although planning has been performed to establish the technical and regulatory bases for their discard and disposal, recovery of these materials is both economically attractive and in the national

  20. Permeability of stylolite-bearing chalk

    SciTech Connect

    Lind, I.; Nykjaer, O.; Priisholm, S. ); Springer, N.

    1994-11-01

    Permeabilities were measured on core plugs from stylolite-bearing chalk of the Gorm field in the Danish North Sea. Air and liquid permeabilities were measured in directions parallel to and perpendicular to the stylolite surface. Permeability was measured with sleeve pressure equal to in-situ reservoir stress. Permeabilities of plugs with stylolites but without stylolite-associated fractures were equal in the two directions. The permeability is equal to the matrix permeability of non-stylolite-bearing chalk. In contrast, when fractures were associated with the stylolites, permeability was enhanced. The enhancement was most significant in the horizontal direction parallel to the stylolites.

  1. Investigating low flow process controls, through complex modelling, in a UK chalk catchment

    NASA Astrophysics Data System (ADS)

    Lubega Musuuza, Jude; Wagener, Thorsten; Coxon, Gemma; Freer, Jim; Woods, Ross; Howden, Nicholas

    2017-04-01

    The typical streamflow response of Chalk catchments is dominated by groundwater contributions due the high degree of groundwater recharge through preferential flow pathways. The groundwater store attenuates the precipitation signal, which causes a delay between the corresponding high and low extremes in the precipitation and the stream flow signals. Streamflow responses can therefore be quite out of phase with the precipitation input to a Chalk catchment. Therefore characterising such catchment systems, including modelling approaches, clearly need to reproduce these percolation and groundwater dominated pathways to capture these dominant flow pathways. The simulation of low flow conditions for chalk catchments in numerical models is especially difficult due to the complex interactions between various processes that may not be adequately represented or resolved in the models. Periods of low stream flows are particularly important due to competing water uses in the summer, including agriculture and water supply. In this study we apply and evaluate the physically-based Pennstate Integrated Hydrologic Model (PIHM) to the River Kennet, a sub-catchment of the Thames Basin, to demonstrate how the simulations of a chalk catchment are improved by a physically-based system representation. We also use an ensemble of simulations to investigate the sensitivity of various hydrologic signatures (relevant to low flows and droughts) to the different parameters in the model, thereby inferring the levels of control exerted by the processes that the parameters represent.

  2. Can we get a better knowledge on dissolution processes in chalk by using microfluidic chips?

    NASA Astrophysics Data System (ADS)

    Neuville, Amélie; Minde, Mona; Renaud, Louis; Vinningland, Jan Ludvig; Dysthe, Dag Kristian; Hiorth, Aksel

    2017-04-01

    mostly occurs at the surface of the sample. The reacting chalk surface is observed in situ by stereomicroscopy and by interferometry. The dissolution velocities are highly heterogeneous. To identify the mineral change of the surface, a posteriori measurements using field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDS). [1] Neuville et al, 2016, Xurography for microfluidics on a reactive solid, Lab on Chip, DOI: 10.1039/c6lc01253a

  3. Race horses vs work horses: Competition between the nuclear weapons labs in the 1950s

    SciTech Connect

    Francis, S.

    1992-01-01

    This document provides a discussion of the missions and research programs of Los Alamos National Laboratory and Lawrence Livermore National Laboratory and details the competition between the two nuclear weapons laboratories in the 1950's. (FI)

  4. Race horses vs work horses: Competition between the nuclear weapons labs in the 1950s

    SciTech Connect

    Francis, S.

    1992-06-01

    This document provides a discussion of the missions and research programs of Los Alamos National Laboratory and Lawrence Livermore National Laboratory and details the competition between the two nuclear weapons laboratories in the 1950`s. (FI)

  5. Russian/US nuclear weapons labs share NDT technologies for emergency response

    SciTech Connect

    Fry, D.A.

    1997-04-01

    In December 1995 a team of NDT experts from Los Alamos National Laboratory travelled to the Russian city of Sarov, also known as Arzamas-16, to officially transfer to Russia NDT equipment--a mobile radiography system--built for use in nuclear emergency response. Previously, during the period August 29 through September 16, 1994, nine Russian nuclear weapons experts had been trained on the safe and effective use and maintenance of this NDT equipment, a mobile radiography capability, at Los Alamos National Laboratory. The training occurred mainly at Los Alamos` Technical Area 8--where NDT in support of the US nuclear weapons program has taken place since the 1940s. The Russians came from the Russian Ministry of Atomic Energy (MINATOM) and the Russian Federal Nuclear Centers at Arzamas-165 (VNIIEF) and Chelyabinsk-70 (VNIITF).

  6. The End of "Chalk and Talk"

    ERIC Educational Resources Information Center

    Barlow, Tim

    2012-01-01

    "Chalk and talk" had been the staple pedagogical approach of my Science teaching practice since entering the profession. I felt that there was a great deal of information that I must impart to my students. My tried and tested way to deliver information to my students had always been simply to stand in front of them and tell it to them... So what…

  7. The End of "Chalk and Talk"

    ERIC Educational Resources Information Center

    Barlow, Tim

    2012-01-01

    "Chalk and talk" had been the staple pedagogical approach of my Science teaching practice since entering the profession. I felt that there was a great deal of information that I must impart to my students. My tried and tested way to deliver information to my students had always been simply to stand in front of them and tell it to them... So what…

  8. Competitive sorption of organic contaminants in chalk

    NASA Astrophysics Data System (ADS)

    Graber, E. R.; Borisover, M.

    2003-12-01

    In the Negev desert, Israel, a chemical industrial complex is located over fractured Eocene chalk formations where transfer of water and solutes between fracture voids and matrix pores affects migration of contaminants in the fractures due to diffusion into the chalk matrix. This study tests sorption and sorption competition between contaminants in the chalk matrix to make it possible to evaluate the potential for contaminant attenuation during transport in fractures. Single solute sorption isotherms on chalk matrix material for five common contaminants ( m-xylene, ametryn, 1,2-dichloroethane, phenanthrene, and 2,4,6-tribromophenol) were found to be nonlinear, as confirmed in plots of Kd versus initial solution concentration. Over the studied concentration ranges, m-xylene Kd varied by more than a factor of 100, ametryn Kd by a factor of 4, 1,2-dichloroethane Kd by more than a factor of 3, phenanthrene Kd by about a factor of 2, and 2,4,6-tribromophenol Kd by a factor of 10. It was earlier found that sorption is to the organic matter component of the chalk matrix and not to the mineral phases (Chemosphere 44 (2001) 1121). Nonlinear sorption isotherms indicate that there is at least some finite sorption domain. Bi-solute competition experiments with 2,4,6-tribromophenol as the competitor were designed to explore the nature of the finite sorption domain. All of the isotherms in the bi-solute experiments are more linear than in the single solute experiments, as confirmed by smaller variations in Kd as a function of initial solution concentration. For both m-xylene and ametryn, there is a small nonlinear component or domain that was apparently not susceptible to competition by 2,4,6-tribromophenol. The nonlinear sorption domain(s) is best expressed at low solution concentrations. Inert-solvent-normalized single and bi-solute sorption isotherms demonstrate that ametryn undergoes specific force interactions with the chalk sorbent. The volume percent of phenanthrene

  9. Environmental radioactivity levels in the Cumberland River at the Hartsville Nuclear Project site, 1975-1982

    SciTech Connect

    Not Available

    1985-07-01

    Samples of surface water taken from the Cumberland River during the period from 1975 through 1982 exhibited radioactivity levels less than 1% of the maximum permissible concentrations published by the Nuclear Regulatory Commission. Radioactivity concentrations reported herein are typical of natural radioactivity levels with slight indications of influences from fallout of radioactivity from atmospheric nuclear weapons testing.

  10. 78 FR 14842 - Crystal River Nuclear Generating Plant, Unit 3; Application for Renewal of License to Facility...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... operate the Crystal River Nuclear Generating Plant, Unit 3 (CR3), at 2609 megawatts thermal. The FPC... COMMISSION Crystal River Nuclear Generating Plant, Unit 3; Application for Renewal of License to Facility.... Nuclear Regulatory Commission (NRC) grants the Florida Power Corporation request to withdraw its...

  11. Giddings Austin chalk enters deep lean-gas phase

    SciTech Connect

    Moritis, G.

    1995-12-25

    Deep lean gas is the latest phase in the growth of the Giddings field Austin chalk play. The first phase involved drilling vertical oil and gas wells. Next came the horizontal well boom in the shallower Austin chalk area, which is still continuing. And now this third phase places horizontal laterals in the Austen chalk at about 14,000--15,000 ft to produce lean gas. The article describes the producing wells and gas gathering.

  12. The Beauty of the Beasts in Chalk Pastels

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2010-01-01

    In this article, the author describes how her seventh-grade art students captured an image of a stuffed animal in the "whole-to-part" drawing technique using chalk pastels. Shading with chalk pastels can give a gradual change in value from dark to light. The shading and color changes the mood of the original drawing, and adds texture, too. Chalk…

  13. Horizontal drilling in the Austin Chalk: Stratigraphic factors

    SciTech Connect

    Durham, C.O. Jr. ); Bobigian, R.A. )

    1990-05-01

    Horizontal drilling has renewed interest in the Austin chalk in south-central Texas. Large fields on opposite sides of the San Marcos arch Giddings to the northeast and Pearsall to the southwest were active with vertical drilling 10 years ago. Giddings' 4,500 Austin wells produced 209 million BO and 934 bcfg of gas through 1988; Pearsall's 1,440 wells produced 57 million BO and 35 bcfg of gas. Most vertical wells were completed, 20% were economic successes, 40% were marginal, 40% were uneconomic due to uneven areal distribution of near-vertical fractures and small faults, which provide reservoirs in otherwise tight chalk. Horizontal drilling, led by Amoco in Giddings and Oryx in Pearsall, enhances the chances of encountering the fractures by drilling perpendicular to the fracture trend. Horizontal drilling requires preselection of the stratigraphic horizon to be penetrated. One must understand the variable Austin stratigraphy to choose the zone with the most brittle character and best matrix porosity, both reduced by increased clay content. Chalk 130 ft thick on the San Marcos arch thickens to 600 to 800 ft in central Giddings field where middle marl separates lower and upper chalk Northeastward only lower chalk is preserved beneath a post-Austin submarine channel. The Austin thickens to 300-500 ft in Pearsall field where middle member ash beds separate lower and upper chalk inhibiting vertical reservoir communication. Locally, on the Pearsall arch, ash is missing, lower chalk thickens, and upper chalk thins.

  14. The Beauty of the Beasts in Chalk Pastels

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2010-01-01

    In this article, the author describes how her seventh-grade art students captured an image of a stuffed animal in the "whole-to-part" drawing technique using chalk pastels. Shading with chalk pastels can give a gradual change in value from dark to light. The shading and color changes the mood of the original drawing, and adds texture, too. Chalk…

  15. CEBAF at Jefferson Lab

    SciTech Connect

    2015-01-01

    The U.S. and international nuclear physics community uses Jefferson Lab's state-of-the-art Continuous Electron Beam Accelerator Facility or CEBAF to conduct world-class fundamental research. The Lab supports more than 1,250 visiting researchers from more than 200 institutions.

  16. New understanding of the complexity of groundwater flow in Chalk catchments of the UK

    NASA Astrophysics Data System (ADS)

    Peach, D.; Shand, P.; Gooddy, D.; Abesser, C.; Bloomfield, J.; Mathias, S.; Butler, A.; Williams, A.; Binley, A.; Wheater, H.

    2006-12-01

    The Chalk is the largest aquifer in the UK accounting for more than half the groundwater used and nearly a quarter of the total public water supplied in England and Wales. Although the Chalk is a double porosity and permeability medium, transmission of water in the saturated zone depends largely on flow through fractures, the location and distribution of which are controlled by lithology and geological structure. These features operate on a number of spatial scales and so provide a range of flow pathways that can markedly affect both stream flow and water quality. In addition, overlying Palaeogene or superficial deposits can act as controls on recharge and zones of increased groundwater storage. As part of a major initiative on Lowland Catchment Research in the UK two Chalk sub-catchments, in the River Thames basin, the rivers Pang and Lambourn, have been the focus of an intensive set of studies. The catchments have been characterised using a multidisciplinary approach. This has resulted in an improved understanding of the way such catchments work and the mechanisms that control groundwater flow. The low fracture porosity gives rise to a low specific yield, which means that large fluctuations in water table elevation beneath the interfluves are not uncommon. Consequently, groundwater catchments differ from the topographic catchments and their size varies seasonally. This means, for example, that groundwater might be flowing to the River Pang in winter but to the River Thames in summer. It also means that various flow features in the catchment may be active at different locations and times during the year. Four flow systems have been identified, through a detailed analysis of the data; a shallow, but rapid flow system; a slower, deeper system; a very high velocity system developed in large diameter solution enhanced fractures and a system found in the river valley sediments. The interconnections between and within these systems can be poor and sometimes vary on a

  17. Intrinsic and Carrier Colloid-facilitated transport of lanthanides through discrete fractures in chalk

    NASA Astrophysics Data System (ADS)

    Weisbrod, N.; Tran, E. L.; Klein-BenDavid, O.; Teutsch, N.

    2015-12-01

    Geological disposal of high-level radioactive waste is the long term solution for the disposal of long lived radionuclides and spent fuel. However, some radionuclides might be released from these repositories into the subsurface as a result of leakage, which ultimately make their way into groundwater. Engineered bentonite barriers around nuclear waste repositories are generally considered sufficient to impede the transport of radionuclides from their source to the groundwater. However, colloidal-sized mobile bentonite particles ("carrier" colloids) originating from these barriers have come under investigation as a potential transport vector for radionuclides sorbed to them. As lanthanides are generally accepted to have the same chemical behaviors as their more toxic actinide counterparts, lanthanides are considered an acceptable substitute for research on radionuclide transportation. This study aims to evaluate the transport behaviors of lanthanides in colloid-facilitated transport through a fractured chalk matrix and under geochemical conditions representative the Negev desert, Israel. The migration of Ce both with and without colloidal particles was explored and compared to the migration of a conservative tracer (bromide) using a flow system constructed around a naturally fractured chalk core. Results suggest that mobility of Ce as a solute is negligible. In experiments conducted without bentonite colloids, the 1% of the Ce that was recovered migrated as "intrinsic" colloids in the form of carbonate precipitates. However, the total recovery of the Ce increased to 9% when it was injected into the core in the presence of bentonite colloids and 13% when both bentonite and precipitate colloids were injected. This indicates that lanthanides are essentially immobile in chalk as a solute but may be mobile as carbonate precipitates. Bentonite colloids, however, markedly increase the mobility of lanthanides through fractured chalk matrices.

  18. Russia-U.S. Joint Program on the Safe Management of Nuclear Materials: Approaches to Prioritizing the Lab to Lab Project

    SciTech Connect

    Carlson, D.; Young, M.

    1998-11-05

    The U.S. and Russian weapons dismantlement process is producing hundreds of tons of excess plutonium (Pu) and highly enriched uranium (HEU) fissile materials. The nuclear operations associated with the final disposition of these materials will be occurring in both countries for decades. A significant accident during these operations could delay the disposition process. Russia- U.S. collaborative efforts to address safety issues associated with disposition processes have been ongoing since 1993. The experience of these collaborative efforts have demonstrated the need for a systematic and formalized approach to identifjring and prioritizing collaborative projects. A systematic approach to the successfid implementation of a formal program will require the definition of year by year program objectives, specific technical program areas, a process for the prioritization and selection of projects, and identification of performance measures to evaluate the success of projects. Specialized working groups established for each technical area are needed to define research priorities, review research proposals, and recommend proposals for tiding. A systematic approach to the establishment of a formal U.S.-Russia cooperative program will serve to ensure the safety and continuity of disposition processes and reduce the nuclear proliferation risks presented by this material. The U.S. and Russian weapons dismantlement process is producing hundreds of tons of excess plutonium (Pu) and highly enriched uranium (HEU) fissile materials. The U.S. and Russia are both converting and blending HEU into low enriched uranium (LEU) for use in existing reactors. Russia also plans to fiel reactors with excess Pu. The U.S. is on a two-path approach for the disposition of excess Pu: (1) use of Pu in existing reactors and/or (2) immobilization of the Pu in glass or ceramics followed by geologic disposal. The fissile nuclear materials storage, handling, processing, and transportation processes

  19. Austin Chalk (!) Petroleum System: Upper Cretaceous, Southeastern Texas

    SciTech Connect

    Dawson, W.C.; Katz, B.J.; Robison, V.D.

    1995-10-01

    The Austin Group (Coniacian-Santonian) is a sequence of interstratified chalk and marl deposited during a sea-level highstand as a transgressive unit. Austin Chalk deposition occurred on a southeastward-dipping carbonate ramp that exhibits distinctive onshore and offshore chalk lithofacies. Discrete intervals within offshore Austin lithofacies display good to excellent source rock potential. Organic carbon content ranges upward to 20.0 wt. % with generation potentials exceeding 45 mg HC/g of rock measured. Source potential increases basinward where offshore chalk units exhibit increases in both organic richness and net thickness. These organically rich units display an affinity for the Type II reference curve. Hydrogen index values typically exceed 300 mg HC/g TOC. Several geochemical indices suggest that the oil-window is located at relatively shallow depths (6,700 ft). Offshore chalks sourced onshore Austin reservoirs through lateral migration (along fractures and stylolites) which occurred during the middle Tertiary. Hydrocarbons may also have been sourced from the underlying Eagle Ford Shale (Turonian). Austin Shale reservoirs are characterized by low porosity/low permeability dual pore systems consisting of microporous matrix and fractures. Diagenesis (mechanical compaction, styloitization, and calcite cementation) has strongly modified Austin Chalk pore systems. Matrix porosity generally decreases with increasing depth because of progressive burial diagenesis. Austin reservoirs typically have two major sets of fractures; reservoir performance is related to fracture connectivity. Austin Chalk reservoirs are sealed by the overlying Taylor Marl (Campanian).

  20. Colloid facilitated transport of lanthanides through discrete fractures in chalk

    NASA Astrophysics Data System (ADS)

    Tran, Emily; Klein Ben-David, Ofra; Teutsch, Nadya; Weisbrod, Noam

    2015-04-01

    Geological disposal of high-level radioactive waste is the internationally agreed-upon, long term solution for the disposal of long lived radionuclides and spent fuel. Eventually, corrosion of the waste canisters may lead to leakage of their hazardous contents, and the radionuclides can ultimately make their way into groundwater and pose a threat to the biosphere. Engineered bentonite barriers placed around nuclear waste repositories are generally considered sufficient to impede the transport of radionuclides from their storage location to the groundwater. However, colloidal-sized mobile bentonite particles eroding from these barriers have come under investigation as a potential transport vector for radionuclides sorbed to them. In addition, the presence of organic matter in groundwater has been shown to additionally facilitate the uptake of radionuclides by the clay colloids. This study aims to evaluate the transport behaviors of radionuclides in colloid-facilitated transport through a fractured chalk matrix and under geochemical conditions representative of the Negev desert, Israel. Lanthanides are considered an acceptable substitute to actinides for research on radionuclide transportation due to their similar chemical behavior. In this study, the migration of Ce both with and without colloidal particles was explored and compared to the migration of a conservative tracer (bromide). Tracer solutions containing known concentrations of Ce, bentonite colloids, humic acid and bromide were prepared in a matrix solution containing salt concentrations representative of that of the average rain water found in the Negev. These solutions were then injected into a flow system constructed around a naturally fractured chalk core. Samples were analyzed for Ce and Br using ICP-MS, and colloid concentrations were determined using spectrophotographic analysis. Breakthrough curves comparing the rates of transportation of each tracer were obtained, allowing for comparison of

  1. Chalk dustfall during classroom teaching: particle size distribution and morphological characteristics.

    PubMed

    Majumdar, Deepanjan; William, S P M Prince

    2009-01-01

    The study was undertaken to examine the nature of particulate chalk dust settled on classroom floor during traditional teaching with dusting and non-dusting chalks on two types of boards viz. rough and smooth. Settling chalk particles were collected for 30 min during teaching in glass Petri plates placed in classrooms within 3 m distance from the teaching boards. Particle size distribution, scanning electron microscopic images of chalk dusts and compressive strength of two types of chalks were tested and evaluated. Results showed that a larger proportion of dusts generated from anti-dusting chalks were of <4.5 and <2.5 microm size on both smooth and rough boards, as compared to dusting chalks. Non-dusting chalks, on an average, produced about 56% and 62% (by volume) of <4.5 microm (respirable) diameter, on rough and smooth boards, respectively, while the corresponding values for dusting chalks were 36% and 45%. Also, on an average, 83% and 94% (by volume) of the particles were <11 microm (thoracic) in case of non-dusting chalks against 61% and 72% for dusting chalks on rough and smooth boards, respectively. Interestingly, taking into account the mass of chalk dust produced per unit time, which was higher in dusting chalks than non dusting chalks, the former was actually producing higher amount of PM <4.5 and <11 particles from both types of boards. Scanning electron microscope images revealed that chalk particles had random shape, although in dusting chalks prevalence of elongated particles was observed, apparently due to the longitudinal breaking of the chalks during writing, which was confirmed during compressive strength testing. We could conclude that dusting chalks could be potentially more harmful than anti dusting chalks, as they produced higher amount of potentially dangerous PM 4.5 and PM 11.

  2. Climate change impacts on Chalk groundwater resources in eastern England

    NASA Astrophysics Data System (ADS)

    Hiscock, K.; Sandhu, C.; Conway, D.

    2004-05-01

    Climate change is expected to cause higher summer temperatures, less summer rainfall and more evapotranspiration in eastern England during this century, thereby increasing the stress on the underlying Chalk aquifer. This study, funded by the Tyndall Centre for Climate Change Research, investigates how future scenarios of climate change will influence groundwater availability in this major regional aquifer in terms of groundwater levels and river baseflow quantities. To examine these scenarios, a two-layer regional groundwater model was constructed with Visual MODFLOW for the Wensum and Nar river catchments in northern East Anglia. The UKCIP02 database for the `2020s High' and `2050s High and Low' gas emission scenarios was used to define selected future climate conditions. Historic recharge (1981-90) to the model is calculated separately, using the FAO approved method incorporating dominant land cover (crop type) and soil moisture content. Future recharge to the model is estimated by perturbing historic rainfall and evapotranspiration with scaling factors relating average monthly simulated future and baseline (1961-90) meteorological parameters. The model results predict an overall decrease in recharge for all three scenarios, with a maximum decrease in October of 62% and 91%, for both the 2020s High and 2050s High scenarios, respectively. The future drier summer periods are likely to cause a delay in the onset of recharge by a month, due to a corresponding overall increase in the evapotranspiration for all scenarios. Faced with these conditions, water companies are planning for less reliable groundwater resources within an overall risk-based approach to managing future water supply and demand.

  3. Evidence of influence of regional and local heterogeneities within a chalk karst aquifer based on nitrates and chlorides analysis

    NASA Astrophysics Data System (ADS)

    El Janyani, S.; Dupont, J. P.; Massei, N.; Dörfliger, N.

    2012-04-01

    In Upper Normandy, a region located in the western Paris Basin, the main source of drinking water comes from the karst aquifer. Developing under the chalk plateaus, it is a covered aquifer overlaid by superficial formations of clay-with-flints and loess. Clay-with-flints result from chalk weathering whereas loess are wind periglacial deposits. The local geologic and hydrogelogic contexts are characterized by a mature development of sinkholes. The chalk karst is causing turbidity, often linked to the fast infiltration of surface water, carrying the products of river and slope erosion and associated contaminants into the aquifer through the sinkholes. Several authors have shown the potential of turbidity as a marker of suspended elements transport and karst conduits fast transport. In this study, we conducted monthly monitoring of 11 boreholes located in the upstream watershed near boreholes (surveyed by the French Geological Survey BRGM): Graveron-Semerville in the Southern department of Upper Normandy (Eure) and Rocquemont in the Norhtern department of Upper Normandy (Seine-Maritime). The monitoring carried out included water level and electrical conductivity (reflecting total water mineralization) measurements, and major elements analysis. In any case, the water levels are similar over time (in accordance with the reference borehole). High mineralizations are observed in the Eure boreholes with significant anomalies of nitrate (70 to 130 mg/l ) and chloride (35 to 90 mg/l). For the Seine Maritime boreholes, no anomalies in nitrates and chlorides were found. To explain such differences, the agricultural activities are not sufficiently different from the study site. The explanation would then come from different reservoirs involved in water storage: loessic formations, thicker and more spreaded in the Seine Maritime department and clay with flints, of significantly higher thickness on average in the Eure department. We also discuss the influence of the drainage

  4. Experimental formation of chalk from calcareous ooze. Technical progress report

    SciTech Connect

    Seyfried, W.E.; Johnson, T.C.

    1981-02-15

    Samples of calcareous ooze collected from the tropical and equatorial Atlantic Ocean were subjected to hydrothermal alteration in order to simulate the diagenesis of chalk. Changes in mineralogy and morphology of enclosed microfossils were measured. (ACR)

  5. Horizontal well drilled into deep, hot Austin chalk

    SciTech Connect

    Pearce, D.; Johnson, M.; Godfrey, B.

    1995-04-03

    Bent-housing steerable downhole motors helped maintain course for a deep, hot, horizontal well in the Austin chalk. The Navasota Unit No. 1 was planned as a B zone, single downdip lateral, Austin chalk horizontal well with a maximum departure from vertical of 3,767 ft and a planned total depth (TD) of 17,342 ft measured depth (MD)/14,172 ft TVD. The Austin chalk was found significantly deeper in this well than planned, which resulted in an actual TD of 17,899 ft MD/14,993 ft TVD, the deepest (TVD) horizontal well in the Austin chalk to date. The well was spudded on August 6, 1994, and took 52 days to reach TD. The static bottom hole temperature was almost 350 F. The paper describes the well plan, drilling results, and the lateral section.

  6. The invertebrate ecology of the Chalk aquifer in England (UK)

    NASA Astrophysics Data System (ADS)

    Maurice, L.; Robertson, A. R.; White, D.; Knight, L.; Johns, T.; Edwards, F.; Arietti, M.; Sorensen, J. P. R.; Weitowitz, D.; Marchant, B. P.; Bloomfield, J. P.

    2016-03-01

    The Chalk is an important water supply aquifer, yet ecosystems within it remain poorly understood. Boreholes (198) in seven areas of England (UK) were sampled to determine the importance of the Chalk aquifer as a habitat, and to improve understanding of how species are distributed. Stygobitic macro-invertebrates were remarkably common, and were recorded in 67 % of boreholes in unconcealed Chalk, although they were not recorded in Chalk that is concealed by low-permeability strata and thus likely to be confined. Most species were found in shallow boreholes (<21 m) and boreholes with deep (>50 m) water tables, indicating that the habitat is vertically extensive. Stygobites were present in more boreholes in southern England than northern England (77 % compared to 38 %). Only two species were found in northern England compared to six in southern England, but overall seven of the eight stygobitic macro-invertebrate species found in England were detected in the Chalk. Two species are common in southern England, but absent from northern England despite the presence of a continuous habitat prior to the Devensian glaciation. This suggests that either they did not survive glaciations in the north where glaciers were more extensive, or dispersal rates are slow and they have never colonised northern England. Subsurface ecosystems comprising aquatic macro-invertebrates and meiofauna, as well as the microbial organisms they interact with, are likely to be widespread in the Chalk aquifer. They represent an important contribution to biodiversity, and may influence biogeochemical cycles and provide other ecosystem services.

  7. Socioeconomic impacts: study of a conceptual nuclear energy center at Green River, Utah

    SciTech Connect

    Weaver, R.; Taylor, J.; Burnett, K.; Greenberg, B.

    1982-02-01

    This document constitutes a segment of a feasibility study investigating the ramifications of constructing a nuclear energy center (NEC) in an arid western region. In this phase of the study, the impacts on socioeconomic conditions in the surrounding communities and possible ways of financing and mitigating these impacts were examined. The general conclusion reached is that the socioeconomic impacts of a nuclear energy center in the Green River area of Southeastern Utah would not impose an absolute bar to NEC development. The economy of the NEC impact area would be substantially transformed by the NEC. In particular, Green River city itself would change from its current status as a relatively stable rural economy with an agricultural, mining, and recreation base to a major city with over 20,000 permanent relatively high income residents. The NEC, by itself, would provide a tax base more than adequate to finance required expansion of public facilities and public human service provisions.

  8. Influence of lithofacies and diagensis on Norwegian North Sea chalk reservoirs

    SciTech Connect

    Brasher, J.E.; Vagle, K.R.

    1996-05-01

    The depositional mechanism of chalk is a key influence in the chalk`s ultimate reservoir quality. Classically, the depositional mechanism is interpreted from core descriptions. Where core data are lacking, dipmeter and borehole imagery logs have proven useful in making lithofacies assessments. Criteria for recognition of three chalk categories are established. Category III chalks correspond to those chalks that have been deposited by gravity flows or slumping and tend to have the best reservoir parameters. Category I chalks are most often affiliated with pelagic deposition and tend to have the poorest reservoir parameters. Category II chalks are intermediate between I and III. Anomalously high primary porosities have been maintained in Norwegian North Sea chalks where the effects of mechanical and chemical compaction have been limited. The diagenetic pathway of a chalk reflects changes brought about by mechanical and chemical compaction. Five factors most heavily influence the diagenetic pathway: (1) burial depth, (2) chalk type, (3) overpressuring, (4) presence of hydrocarbons, and (5) original grain size. Assessments of the sedimentological model, diagenetic pathway, and resultant reservoir quality are provided in case studies of Edda, Tor, and Eldfisk fields. Because the distribution of chalk is largely independent of existing structures, most fields have a component of stratigraphic/diagenetic trapping. Each case study shows unique examples of how petrophysical and reservoir engineering data can be incorporated in assessments of chalk type and the diagenetic pathway and how they may affect reservoir parameters and productivity.

  9. Understanding heterogeneity in UK Chalk catchments and its influence on groundwater flooding

    NASA Astrophysics Data System (ADS)

    Peach, D. W.; Vounaki, T.; Jackson, C. R.; Hughes, A. G.; Wheater, H. S.

    2008-12-01

    The numerical simulation of groundwater flooding is increasingly necessary as this problem is gaining recognition from government and regulators and climate change may bring more extreme events. The Natural Environment Research Council of the UK is funding the British Geological Survey, Imperial College, and the Centre for Ecology and Hydrology to examine the problem of groundwater flooding in the Cretaceous Chalk of Berkshire, 50 kilometres west of London. Typically regional resource issues can be examined using traditional groundwater models that do not consider in detail the influence of flow in the unsaturated zone, but the delays in recharge transmission through this zone to the water table may be very significant in terms of flood timing and prediction. The position of ground elevation relative to water table is clearly important but not often considered in groundwater resource modelling. Groundwater level and stream (and flood) flow responses are important data that may be hard to gather from typical groundwater monitoring systems. These problems have been examined in a Chalk catchment in Berkshire where good records of the 2000-1 and 2003 flooding events have been collected, including flooded extent, rainfall, groundwater levels, river and spring flows. From this analysis, it appears that two groundwater mounds develop in the upper part of the Pang and Lambourn catchments. These mounds intersect dry valleys, which flowed for several months, the consequent flooding causing considerably disruption. Modelling of these events is providing new insight into the heterogeneity of Chalk transmissivity and storage parameters, enhanced knowledge of its dual permeability and porosity and demonstrating the importance of understanding the post-depositional hydrogeological history of the aquifer.

  10. Geology and hydrology of the Elk River, Minnesota, nuclear-reactor site

    USGS Publications Warehouse

    Norvitch, Ralph F.; Schneider, Robert; Godfrey, Richard G.

    1963-01-01

    The Elk River, Minn., nuclear-reactor site is on the east bluff of the Mississippi River about 35 miles northwest of Minneapolis and St. Paul. The area is underlain by about 70 to 180 feet of glacial drift, including at the top as much as 120 feet of outwash deposits (valley train) of the glacial Mississippi River. The underlying Cambrian bedrock consists of marine sedimentary formations including artesian sandstone aquifers. A hypothetically spilled liquid at the reactor site could follow one or both of two courses, thus: (1) It could flow over the land surface and through an artificial drainage system to the river in a matter of minutes; (2) part or nearly all of it could seep downward to the water table and then move laterally to the river. The time required might range from a few weeks to a year, or perhaps more. The St. Paul and Minneapolis water-supply intakes, 21 and 25 miles downstream, respectively, are the most critical points to be considered in the event of an accidental spill. Based on streamflow and velocity data for the Mississippi River near Anoka, the time required for the maximum concentration of a contaminant to travel from the reactor site to the St. Paul intake was computed to be about 8 hours, at the median annual maximum daily discharge. For this discharge, the maximum concentration at the intake would be about 0.0026 microcurie per cubic foot for the release of 1 curie of activity into the river near the reactor site.

  11. Gas/oil capillary pressure at chalk at elevated pressures

    SciTech Connect

    Christoffersen, K.R.; Whitson, C.H.

    1995-09-01

    Accurate capillary pressure curves are essential for studying the recovery of oil by gas injection in naturally fractured chalk reservoirs. A simple and fast method to determine high-pressure drainage capillary pressure curves has been developed. The effect of gas/oil interfacial tension (IFT) on the capillary pressure of chalk cores has been determined for a methane/n-pentane system. Measurements on a 5-md outcrop chalk core were made at pressures of 70, 105, and 130 bar, with corresponding IFT`s of 6.3, 3.2, and 1.5 mN/m. The results were both accurate and reproducible. The measured capillary pressure curves were not a linear function of IFT when compared with low-pressure centrifuge data. Measured capillary pressures were considerably lower than IFT-scaled centrifuge data. It appears that the deviation starts at an IFT of about 5 mN/m. According to the results of this study, the recovery of oil by gravity drainage in naturally fractured chalk reservoirs may be significantly underestimated if standard laboratory capillary pressure curves are scaled by IFT only. However, general conclusions cannot be made on the basis on only this series of experiments on one chalk core.

  12. Homing in on sweet spots in Cretaceous Austin chalk

    SciTech Connect

    Thomas, G.E. ); Sonnenberg, F.P.

    1993-11-29

    In discussing the nature and causes of fracturing in the Cretaceous Austin chalk of south central Texas, many geologists and operators involved in horizontal drilling of the chalk consider regional rock stress as the probable main cause of the fractures. If Austin chalk fractures are mainly the result of regional extensional stress without localizing factors, then fractured sweet spots are randomly distributed and successful exploration is more or less a matter of luck, usually dependent upon the coincidental placement of a seismic line. But if local, deep-seated structure or basement topography are the main causes of sweet spots, then a successful exploration method would be to first delineate the basement paleo structure or topography and secondly, place a seismic line to confirm the delineated features. Finding localities of maximum fracturing and production would than be based on scientific logic rather than luck. It is the purpose of this article to present the results of an examination of these alternative causes for the Austin chalk fracturing in the hope of determining the most cost effective exploration method for the fractured chalk reservoir.

  13. End-cretaceous brachiopod extinctions in the chalk of denmark.

    PubMed

    Surlyk, F; Johansen, M B

    1984-03-16

    The results of a detailed study of the brachiopods of the most complete Cretaceous-Tertiary boundary in Denmark, Nye Klslashed circlev, show an extinction pattern for this marine invertebrate group compatible with that reported for pelagic foraminifera and coccoliths and with the impact scenario. The extinction is abrupt, coinciding with the Maastrichtian-Danian boundary. There is no warning in the form of decreasing density, decreasing diversity, or early extinction of specialized groups. The basal few meters of the Danian are almost devoid of brachiopods, and a Danian brachiopod fauna starts almost as abruptly as the Maastrichtian fauna disappeared. The new fauna is similar to the Maastrichtian as regards density and diversity, and at maximum six species are common to both stages. The northwest European Masstrichtian chalk is composed mainly of the remains of coccoliths and pelagic foraminifera. The mass extinction of these groups led to a total cessation of chalk production. The chalk is overlain by a thin clay bed deposited partly under anoxic conditions. This combination of anoxia and clay deposition coupled with a cessation of productivity led to the extinction of specialized groups such as the chalk brachiopods. The surviving species included forms that could survive in well-aerated shallow marine waters on substrates other than chalk.

  14. End-Cretaceous Brachiopod Extinctions in the Chalk of Denmark

    NASA Astrophysics Data System (ADS)

    Surlyk, Finn; Bagge Johansen, Marianne

    1984-03-01

    The results of a detailed study of the brachiopods of the most complete Cretaceous-Tertiary boundary in Denmark, Nye Klov, show an extinction pattern for this marine invertebrate group compatible with that reported for pelagic foraminifera and coccoliths and with the impact scenario. The extinction is abrupt, coinciding with the Maastrichtian-Danian boundary. There is no warning in the form of decreasing density, decreasing diversity, or early extinction of specialized groups. The basal few meters of the Danian are almost devoid of brachiopods, and a Danian brachiopod fauna starts almost as abruptly as the Maastrichtian fauna disappeared. The new fauna is similar to the Maastrichtian as regards density and diversity, and at maximum six species are common to both stages. The northwest European Maastrichtian chalk is composed mainly of the remains of coccoliths and pelagic foraminifera. The mass extinction of these groups led to a total cessation of chalk production. The chalk is overlain by a thin clay bed deposited partly under anoxic conditions. This combination of anoxia and clay deposition coupled with a cessation of productivity led to the extinction of specialized groups such as the chalk brachiopods. The surviving species included forms that could survive in well-aerated shallow marine waters on substrates other than chalk.

  15. Cyclic sedimentation, synsedimentary volcanism, microfabrics, and fracture intensity in the Austin Chalk, Texas

    SciTech Connect

    Hovorka, S.D. )

    1992-01-01

    Pelagic depositional environments of the Austin Chalk (Coniacian-Santonian) were influenced by sea-level variation, planktonic productivity, and allochthonous detrital input. Subtle differences in chalk facies influence fracture intensity, therefore imposing stratigraphic variability on hydrologic properties of the Austin Chalk. Variations in fracture intensity may affect ground-water flow through the Superconducting Super Collider (SSC) site south of Dallas in the same way that they influence hydrocarbon production in South Texas. The lower Austin Chalk was deposited during transgression. Glauconitic sandstone is overlain by cyclic chalk containing chalk-filled channels. Meter-thick chalk/marl cycles have frequencies in the Milankovitch spectrum. Marl accumulated during episodes of decreased planktonic productivity. Maximum flooding is indicated by organic-rich marls in the upper part of the Lower Austin Chalk. Shallowing during deposition of the middle and upper Austin Chalk is indicated by increasing abundance of winnowed lag deposits and firm grounds, resulting in increased faunal diversity. Authigenic clay, a product of alteration of volcanic ash codeposited with the chalk and marl, increases ductility in the middle Austin Chalk. The stratigraphic distribution of authigenic clay corresponds to disseminated biotite, quartz, and feldspar phenocrysts in most samples of the middle Austing Chalk. Authigenic clay decreases porosity, influences porosity-permeability relationships, and provides a regionally traceable low SP log response that correlates with low fracture intensity.

  16. Surface Water - Groundwater Interaction Research in Chalk Catchments: UK Lowland Catchment Research Programme (LOCAR)

    NASA Astrophysics Data System (ADS)

    Peach, D.; Wheater, H.; Howden, N.; Gallagher, A.; Bloomfield, J.

    2004-12-01

    The focus of new European legislation on integrated management and, in particular, on ecological quality, raises major scientific and technical questions. These require improved understanding of catchment systems and hydro-ecological interactions that can only be obtained from integrated and multi-disciplinary experimental research. The main water supply aquifers in the United Kingdom, namely the Cretaceous Chalk and Permo-Triassic Sherwood Sandstone, are situated, for the most part, in lowland England, particularly in the Midlands, South and South East. These aquifers have a major, often dominant influence on the river systems that they underlie. These lowland permeable catchments present a particular set of challenges; management pressures are great, the scientific understanding of the major UK aquifers is poor, and tools for the integrated modelling of surface water-groundwater interactions and associated hydro-ecological processes are limited. In response to these factors, the LOwland CAtchment Research programme (LOCAR) was conceived. The programme also provides intrumented catchments to address some of these scientific issues. This paper describes the programme and early results of research into the influence of lithostratigraphy and karst features on surface water/groundwater interaction in the two Chalk LOCAR catchments.

  17. What are the governing processes during low-flows in a chalk catchment?

    NASA Astrophysics Data System (ADS)

    Lubega Musuuza, Jude; Coxon, Gemma; Hutton, Chris; Howden, Nicholas; Woods, Ross; Freer, Jim; Wagener, Thorsten

    2016-04-01

    Low flows are important because they lead to the prioritisation of different consumptive water usages, imposition of restrictions and bans, raising of water tariffs and higher production costs to industry. The partitioning of precipitation into evaporation, storage and runoff depends on the local variability in meteorological variables and site-specific characteristics e.g., topography, soils and vegetation. The response of chalk catchments to meteorological forcing especially precipitation is of particular interest because of the preferential flow through the weathered formation. This makes the observed stream discharge groundwater-dominated and hence, out of phase with precipitation. One relevant question is how sensitive the low flow characteristics of such a chalk catchment is to changes in climate and land use. It is thus important to understand all the factors that control low stream discharge periods. In this study we present the results from numerical sensitivity analysis experiments performed with a detailed physically-based model on the Kennet, a sub-catchment of the River Thames, in the UK during the historical drought years of the 1970's.

  18. Horizontal spacing, depletion, and infill potential in the Austin Chalk

    SciTech Connect

    Kyte, D.G.; Meehan, D.N.

    1996-12-31

    There have been more than 4500 laterals drilled in the Austin Chalk. This paper looks at estimated ultimate recoveries (EUR) on a barrels/acre basis for these Austin Chalk wells. Baffels/acre recoveries were computed by estimating ultimate per-well recoveries, drilled density and the impact of vertical production. The data were then analyzed for depletion and infill potential. Certain areas were selected for further study using an artificial neural network. The network was built and used to study the effects of parameters such as lateral length, first production date, structure of the Austin Chalk, etc. on these recoverable barrel/acre numbers. The methodology and regional results of the study are reviewed with detailed analyses shown in selected areas.

  19. Savannah River Site Spent Nuclear Fuel Management Final Environmental Impact Statement

    SciTech Connect

    N /A

    2000-04-14

    The proposed DOE action considered in this environmental impact statement (EIS) is to implement appropriate processes for the safe and efficient management of spent nuclear fuel and targets at the Savannah River Site (SRS) in Aiken County, South Carolina, including placing these materials in forms suitable for ultimate disposition. Options to treat, package, and store this material are discussed. The material included in this EIS consists of approximately 68 metric tons heavy metal (MTHM) of spent nuclear fuel 20 MTHM of aluminum-based spent nuclear fuel at SRS, as much as 28 MTHM of aluminum-clad spent nuclear fuel from foreign and domestic research reactors to be shipped to SRS through 2035, and 20 MTHM of stainless-steel or zirconium-clad spent nuclear fuel and some Americium/Curium Targets stored at SRS. Alternatives considered in this EIS encompass a range of new packaging, new processing, and conventional processing technologies, as well as the No Action Alternative. A preferred alternative is identified in which DOE would prepare about 97% by volume (about 60% by mass) of the aluminum-based fuel for disposition using a melt and dilute treatment process. The remaining 3% by volume (about 40% by mass) would be managed using chemical separation. Impacts are assessed primarily in the areas of water resources, air resources, public and worker health, waste management, socioeconomic, and cumulative impacts.

  20. Human Geophagia, Calabash Chalk and Undongo: Mineral Element Nutritional Implications

    PubMed Central

    Abrahams, Peter W.; Davies, Theo C.; Solomon, Abiye O.; Trow, Amanda J.; Wragg, Joanna

    2013-01-01

    The prime aim of our work is to report and comment on the bioaccessible concentrations – i.e., the soluble content of chemical elements in the gastrointestinal environment that is available for absorption – of a number of essential mineral nutrients and potentially harmful elements (PHEs) associated with the deliberate ingestion of African geophagical materials, namely Calabash chalk and Undongo. The pseudo-total concentrations of 13 mineral nutrients/PHEs were quantified following a nitric-perchloric acid digestion of nine different Calabash chalk samples, and bioaccessible contents of eight of these chemical elements were determined in simulated saliva/gastric and intestinal solutions obtained via use of the Fed ORganic Estimation human Simulation Test (FOREhST) in vitro procedure. The Calabash chalk pseudo-total content of the chemical elements is often below what may be regarded as average for soils/shales, and no concentration is excessively high. The in vitro leachate solutions had concentrations that were often lower than those of the blanks used in our experimental procedure, indicative of effective adsorption: lead, a PHE about which concern has been previously raised in connection with the consumption of Calabash chalk, was one such chemical element where this was evident. However, some concentrations in the leachate solutions are suggestive that Calabash chalk can be a source of chemical elements to humans in bioaccessible form, although generally the materials appear to be only a modest supplier: this applies even to iron, a mineral nutrient that has often been linked to the benefits of geophagia in previous academic literature. Our investigations indicate that at the reported rates of ingestion, Calabash chalk on the whole is not an important source of mineral nutrients or PHEs to humans. Similarly, although Undongo contains elevated pseudo-total concentrations of chromium and nickel, this soil is not a significant source to humans for any of the

  1. Evaluation of nuclear facility decommissioning projects. Project summary report, Elk River Reactor

    SciTech Connect

    Miller, R.L.; Adams, J.A.

    1982-12-01

    This report summarizes information concerning the decommissioning of the Elk River Reactor. Decommissioning data from available documents were input into a computerized data-handling system in a manner that permits specific information to be readily retrieved. The information is in a form that assists the Nuclear Regulatory Commission in its assessment of decommissioning alternatives and ALARA methods for future decommissionings projects. Samples of computer reports are included in the report. Decommissioning of other reactors, including NRC reference decommissioning studies, will be described in similar reports.

  2. SAVANNAH RIVER SITE'S H-CANYON FACILITY: IMPACTS OF FOREIGN OBLIGATIONS ON SPECIAL NUCLEAR MATERIAL DISPOSITION

    SciTech Connect

    Magoulas, V.

    2013-06-03

    The US has a non-proliferation policy to receive foreign and domestic research reactor returns of spent fuel materials of US origin. These spent fuel materials are returned to the Department of Energy (DOE) and placed in storage in the L-area spent fuel basin at the Savannah River Site (SRS). The foreign research reactor returns fall subject to the 123 agreements for peaceful cooperation. These “123 agreements” are named after section 123 of the Atomic Energy Act of 1954 and govern the conditions of nuclear cooperation with foreign partners. The SRS management of these foreign obligations while planning material disposition paths can be a challenge.

  3. LabView Based Nuclear Physics Laboratory experiments as a remote teaching and training tool for Latin American Educational Centers

    SciTech Connect

    Sajo-Bohus, L.; Greaves, E. D.; Barros, H.; Gonzalez, W.; Rangel, A.

    2007-10-26

    A virtual laboratory via internet to provide a highly iterative and powerful teaching tool for scientific and technical discipline is given. The experimenter takes advantage of a virtual laboratory and he can execute nuclear experiment at introductory level e.g. Gamma ray detection with Geiger-Mueller Counter at remote location using internet communication technology.

  4. Dual FIB-SEM 3D Imaging and Lattice Boltzmann Modeling of Porosimetry and Multiphase Flow in Chalk

    NASA Astrophysics Data System (ADS)

    Rinehart, A. J.; Yoon, H.; Dewers, T. A.; Heath, J. E.; Petrusak, R.

    2010-12-01

    Mercury intrusion porosimetry (MIP) is an often-applied technique for determining pore throat distributions and seal analysis of fine-grained rocks. Due to closure effects, potential pore collapse, and complex pore network topologies, MIP data interpretation can be ambiguous, and often biased toward smaller pores in the distribution. We apply 3D imaging techniques and lattice-Boltzmann modeling in interpreting MIP data for samples of the Cretaceous Selma Group Chalk. In the Mississippi Interior Salt Basin, the Selma Chalk is the apparent seal for oil and gas fields in the underlying Eutaw Fm., and, where unfractured, the Selma Chalk is one of the regional-scale seals identified by the Southeast Regional Carbon Sequestration Partnership for CO2 injection sites. Dual focused ion - scanning electron beam and laser scanning confocal microscopy methods are used for 3D imaging of nanometer-to-micron scale microcrack and pore distributions in the Selma Chalk. A combination of image analysis software is used to obtain geometric pore body and throat distributions and other topological properties, which are compared to MIP results. 3D data sets of pore-microfracture networks are used in Lattice Boltzmann simulations of drainage (wetting fluid displaced by non-wetting fluid via the Shan-Chen algorithm), which in turn are used to model MIP procedures. Results are used in interpreting MIP results, understanding microfracture-matrix interaction during multiphase flow, and seal analysis for underground CO2 storage. This work was supported by the US Department of Energy, Office of Basic Energy Sciences as part of an Energy Frontier Research Center. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Why Chalk Breaks into Three Pieces When Dropped

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    It has been the author's experience over many years, no doubt shared by others, that a stick of chalk usually breaks into three pieces when accidentally dropped onto the floor. I rarely gave it any thought, apart from noting that the fundamental mode of vibration of a freely supported, rigid rod has two nodes at an equal distance from each…

  6. Completion techniques for horizontal wells in the Pearsall Austin Chalk

    SciTech Connect

    Pope, C.D.; Handren, P.J. )

    1992-05-01

    Oryx Energy Co. used three basic completion techniques and various combinations of them to complete 20 horizontal wells in the Pearsall Austin Chalk. The completion method selected is based on a general set of guidelines. In this paper additionally, equipment selection and various types of workover operations are reviewed.

  7. Why Chalk Breaks into Three Pieces When Dropped

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    It has been the author's experience over many years, no doubt shared by others, that a stick of chalk usually breaks into three pieces when accidentally dropped onto the floor. I rarely gave it any thought, apart from noting that the fundamental mode of vibration of a freely supported, rigid rod has two nodes at an equal distance from each…

  8. Impact-assessment report: Chalk Point Steam Electric Station aquatic-monitoring program

    SciTech Connect

    Not Available

    1985-01-01

    The Chalk Point Steam Electric Station (SES), owned and operated by the Potomac Electric Power Company (PEPCO), is located in the estuarine portion of the Patuxent River just above the Benedict Bridge near Aquasco, Maryland. The plant's two coal-fired units use once-through cooling systems and pursuant to the Code of Maryland Regulations 10.50.01.13, which governs water-quality impact assessments for thermal discharges, PEPCO is required to: assess compliance with mixing-zone specifications that relate discharge flows and thermal-plume size to advective and diffusive properties of the receiving-water body; determine the magnitude and consequences of plant impacts on spawning and nursery areas for organisms that are representative of and important to the receiving body; and determine the magnitude and dollar value of impingement losses.

  9. Sediment transport and siltation of brown trout (Salmo trutta L.) spawning gravels in chalk streams

    NASA Astrophysics Data System (ADS)

    Acornley, R. M.; Sear, D. A.

    1999-02-01

    Deposition rates of fine sediment into brown trout spawning gravels were measured at monthly intervals for a period of one year in a small channel of the River Test, Hampshire. Data were also collected on stream discharge, water depth, flow velocity and suspended sediment concentrations. Deposition rates followed a seasonal pattern and were maximal during periods of high discharge in the late winter/early spring when suspended sediment concentrations were high. The material deposited in the spawning gravels included silts and fine sands (<250 m) that were transported in suspension and coarser fragments of low density tufa-like material that were transported as bed load. The ecological implications of fine sediment deposition for salmonid egg survival in chalk streams are considered.

  10. Radon in Chalk streams: Spatial and temporal variation of groundwater sources in the Pang and Lambourn catchments, UK

    NASA Astrophysics Data System (ADS)

    Mullinger, N. J.; Binley, A. M.; Pates, J. M.; Crook, N. P.

    2007-06-01

    SummaryVariations in dissolved 222Rn (radon) concentrations in rivers and groundwater are observed in the Cretaceous Chalk catchments of the Pang and Lambourn. Stream radon concentrations and flow data were used to model radon inputs to rivers from groundwater, with the modelled radon input concentrations ( CI) varying between 0.2 Bq l -1 and 3.8 Bq l -1, consistent with measured groundwater values. Groundwater in both catchments was found to have higher and more variable radon concentrations (2-12 Bq l -1) in the near surface, weathered horizons, compared to a consistent 1 Bq l -1 from the solid Chalk. The variations in CI can be related to flow generation pathways and hydrological events. In the Lambourn, the radon budget is controlled by diffuse groundwater inputs, supporting the hypothesis that the alluvial aquifer plays a greater role during periods of high accretion. The Pang is more complex than the Lambourn having a combination of diffuse and point source inputs, with spring inputs dominating both flow and radon signatures in the lower part of the catchment. Significant temporal and spatial variations were determined for CI in both catchments reflecting their differing geologies and flow regimes. One use of radon in hydrology is the determination of groundwater discharges to rivers, but the observed variations in CI mean this approach may not be appropriate to all situations and that changes in source need further evaluation. Nonetheless, radon is shown to be a useful tracer of flow paths and processes within these catchments.

  11. Trace Elemental Characterization of Chalk Dust and Their Associated Health Risk Assessment.

    PubMed

    Maruthi, Y A; Ramprasad, S; Lakshmana Das, N

    2017-02-01

    It is evident that chalk produces dust on use, i.e., particulate matter, which will alter the air quality of classrooms and can cause health hazards in teachers. The possible causes for health effects of chalk dust on teachers are still unclear. Hence, the aim of this study is to estimate the concentration of trace elements (Al, Cr, Mn, Fe, Co, Ni, Si, Pb) in chalk dust collected from classrooms by using ICP-MS. Both suspended and settled chalk dust was collected from selected classrooms. Suspended chalk dust was collected with PM2.5 filter paper using fine dust sampler, and settled chalk dust was collected by placing petriplates at a distance of 3 m from the board for a duration period of 30 min. Scanning electron microscopy images of chalk dust were taken up. Potential health risk analysis was also assessed. Results showed that Al, Fe, and Mn are in higher concentration (>1000 μg kg(-1)) in both settled and suspended chalk dust. Cr, Mn, Fe, Co, and Ni were beyond the minimal risk levels in both settled and suspended chalk dust. There are no minimal risk levels for the elements Al, Si, and Pb. The concentration of trace elements in suspended chalk dust was higher than that in settled chalk dust. The SEM images of PM2.5 filter papers (suspended chalk dust) showed that all pores of the sampled filter papers are clogged with chalk dust. The few SEM images of the settled chalk dust showed fibrous shape which is associated with good-quality chalk whereas others showed circular and more aggregated nature of chalk dust from low-quality chalk from which the dust production will be very high. As observed from the result that the trace elements concentration was high in the suspended chalk dust, the fact can be correlated with the SEM images which have shown high density of absorbed chalk dust. With reference to human health risk, dermal exposure was the main route of exposure followed by inhalation and ingestion. Al (aluminum), Fe (iron), Si (silicon), and Mn

  12. Structural shimming for high-resolution nuclear magnetic resonance spectroscopy in lab-on-a-chip devices.

    PubMed

    Ryan, Herbert; Smith, Alison; Utz, Marcel

    2014-05-21

    High-resolution proton NMR spectroscopy is well-established as a tool for metabolomic analysis of biological fluids at the macro scale. Its full potential has, however, not been realised yet in the context of microfluidic devices. While microfabricated NMR detectors offer substantial gains in sensitivity, limited spectral resolution resulting from mismatches in the magnetic susceptibility of the sample fluid and the chip material remains a major hurdle. In this contribution, we show that susceptibility broadening can be avoided even in the presence of substantial mismatch by including suitably shaped compensation structures into the chip design. An efficient algorithm for the calculation of field maps from arbitrary chip layouts based on Gaussian quadrature is used to optimise the shape of the compensation structure to ensure a flat field distribution inside the sample area. Previously, the complexity of microfluidic NMR systems has been restricted to simple capillaries to avoid susceptibility broadening. The structural shimming approach introduced here can be adapted to virtually any shape of sample chamber and surrounding fluidic network, thereby greatly expanding the design space and enabling true lab-on-a-chip systems suitable for high-resolution NMR detection.

  13. Environmental assessment for DOE permission for off-loading activities to support the movement of commercial low level nuclear waste across the Savannah River Site

    SciTech Connect

    1995-02-01

    This environmental assessment investigates the potential environmental and safety effects which could result from the land transport of low level radioactive wastes across the Savannah River Plant. Chem-Nuclear Systems operates a low level radioactive waste burial facility adjacent to the Savannah River Plant and is seeking permission from the DOE to transport the waste across Savannah River Plant.

  14. Advanced LabVIEW Labs

    SciTech Connect

    Jones, Eric D.

    1999-06-17

    In the world of computer-based data acquisition and control, the graphical interface program LabVIEW from National Instruments is so ubiquitous that in many ways it has almost become the laboratory standard. To date, there have been approximately fifteen books concerning LabVIEW, but Professor Essick's treatise takes on a completely different tack than all of the previous discussions. In the more standard treatments of the ways and wherefores of LabVIEW such as LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control by Gary W. Johnson (McGraw Hill, NY 1997), the emphasis has been instructing the reader how to program LabVIEW to create a Virtual Instrument (VI) on the computer for interfacing to a particular instruments. LabVIEW is written in "G" a graphical programming language developed by National Instruments. In the past the emphasis has been on training the experimenter to learn "G". Without going into details here, "G" incorporates the usual loops, arithmetic expressions, etc., found in many programming languages, but in an icon (graphical) environment. The net result being that LabVIEW contains all of the standard methods needed for interfacing to instruments, data acquisition, data analysis, graphics, and also methodology to incorporate programs written in other languages into LabVIEW. Historically, according to Professor Essick, he developed a series of experiments for an upper division laboratory course for computer-based instrumentation. His observation was that while many students had the necessary background in computer programming languages, there were students who had virtually no concept about writing a computer program let alone a computer- based interfacing program. Thus the beginnings of a concept for not only teaching computer- based instrumentation techniques, but aiso a method for the beginner to experience writing a com- puter program. Professor Essick saw LabVIEW as the "perfect environment in which to teach

  15. Advanced LabVIEW Labs

    SciTech Connect

    Jones, Eric D.

    1999-06-17

    In the world of computer-based data acquisition and control, the graphical interface program LabVIEW from National Instruments is so ubiquitous that in many ways it has almost become the laboratory standard. To date, there have been approximately fifteen books concerning LabVIEW, but Professor Essick's treatise takes on a completely different tack than all of the previous discussions. In the more standard treatments of the ways and wherefores of LabVIEW such as LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control by Gary W. Johnson (McGraw Hill, NY 1997), the emphasis has been instructing the reader how to program LabVIEW to create a Virtual Instrument (VI) on the computer for interfacing to a particular instruments. LabVIEW is written in G a graphical programming language developed by National Instruments. In the past the emphasis has been on training the experimenter to learn G . Without going into details here, G incorporates the usual loops, arithmetic expressions, etc., found in many programming languages, but in an icon (graphical) environment. The net result being that LabVIEW contains all of the standard methods needed for interfacing to instruments, data acquisition, data analysis, graphics, and also methodology to incorporate programs written in other languages into LabVIEW. Historically, according to Professor Essick, he developed a series of experiments for an upper division laboratory course for computer-based instrumentation. His observation was that while many students had the necessary background in computer programming languages, there were students who had virtually no concept about writing a computer program let alone a computer- based interfacing program. Thus the beginnings of a concept for not only teaching computer- based instrumentation techniques, but aiso a method for the beginner to experience writing a com- puter program. Professor Essick saw LabVIEW as the perfect environment in which to teach computer

  16. H CANYON PROCESSING IN CORRELATION WITH FH ANALYTICAL LABS

    SciTech Connect

    Weinheimer, E.

    2012-08-06

    Management of radioactive chemical waste can be a complicated business. H Canyon and F/H Analytical Labs are two facilities present at the Savannah River Site in Aiken, SC that are at the forefront. In fact H Canyon is the only large-scale radiochemical processing facility in the United States and this processing is only enhanced by the aid given from F/H Analytical Labs. As H Canyon processes incoming materials, F/H Labs provide support through a variety of chemical analyses. Necessary checks of the chemical makeup, processing, and accountability of the samples taken from H Canyon process tanks are performed at the labs along with further checks on waste leaving the canyon after processing. Used nuclear material taken in by the canyon is actually not waste. Only a small portion of the radioactive material itself is actually consumed in nuclear reactors. As a result various radioactive elements such as Uranium, Plutonium and Neptunium are commonly found in waste and may be useful to recover. Specific processing is needed to allow for separation of these products from the waste. This is H Canyon's specialty. Furthermore, H Canyon has the capacity to initiate the process for weapons-grade nuclear material to be converted into nuclear fuel. This is one of the main campaigns being set up for the fall of 2012. Once usable material is separated and purified of impurities such as fission products, it can be converted to an oxide and ultimately turned into commercial fuel. The processing of weapons-grade material for commercial fuel is important in the necessary disposition of plutonium. Another processing campaign to start in the fall in H Canyon involves the reprocessing of used nuclear fuel for disposal in improved containment units. The importance of this campaign involves the proper disposal of nuclear waste in order to ensure the safety and well-being of future generations and the environment. As processing proceeds in the fall, H Canyon will have a substantial

  17. Redox conditions in the Late Cretaceous Chalk Sea: the possible use of cerium anomalies as palaeoredox indicators in the Cenomanian and Turonian Chalk of England

    NASA Astrophysics Data System (ADS)

    Jeans, Christopher V.; Wray, David S.; Williams, C. Terry

    2015-09-01

    The cerium anomalies preserved in the Chalk have been investigated as possible palaeoredox indicators of the Late Cretaceous Sea and its sediment. This has been based upon over a hundred new rare earth element analyses of selected samples and grain size fractions from the Chalk. Particular attention has been given to the methodology of differentiating between the cerium anomalies preserved in the bioclastic calcite and those in carbonate-fluorapatite preserved in the acetic acid insoluble residues of chalks. Variations in the cerium anomaly of different particle size fractions of uncemented chalks suggest that fractionation of rare earth elements between the Chalk's seawater and the various organisms that contributed skeletal material to the bioclastic calcite of the Chalk may have occurred. Post-depositional processes of calcite cementation and late diagenetic sulphidisation have had no apparent effect on the cerium anomaly of the acetic acid insoluble residues. The cerium anomalies associated with the acetic acid insoluble residues from (1) an alternating sequence of chalks and marls from Ballard Cliff (Dorset, UK) typical of Milankovitch cyclicity show a marked diagenetic pattern, whereas those from (2) non-volcanic and volcanic marls display a pattern that is best explained by the variations in the availability of phosphorus and the timing of argillisation of volcanic glass during diagenesis. The general conclusion is drawn that the cerium anomalies preserved in the Chalk can provide an insight into the changing palaeoredox conditions in the Late Cretaceous Sea as well as in the pore fluids of its sediments.

  18. Seismic geomorphology of the Danish Chalks, offshore, North Sea

    NASA Astrophysics Data System (ADS)

    Smit, Florian; van Buchem, Frans; Schmidt, Ingelise

    2014-05-01

    The Upper Cretaceous and Lowermost Paleocene chalk deposits of the North Sea Basin constitute a unique phase in the evolution of carbonate facies, through the rock-forming dominance of fine grained calcareous plankton, particularly coccolithophorids. These planktonic organisms were deposited over extensive areas and very often laid down as laterally extensive, regular dm-scale bedded packages, that locally may reach a thickness of up to 1250 m. In the Danish Graben, the depositional conditions for the chalk sedimentation changed dramatically during the middle of the Upper Cretaceous. At this time the basin topography was inverted, radically changing the position of the depocenters and the ocean floor morphology. In uplifted areas local erosion and long phases of non-deposition occurred, whereas in areas of subsidence thick packages of chalk accumulated. Along the newly created highs, mass waste deposition took place at the deca-kilometre scale. In this presentation we will document evidence for the tectonic inversion, and pay particular attention to the rich pallet of geomorphological features that characterise this tectonically active period. This study benefitted from a recently re-processed 3D seismic dataset (6000 km²), and a regional well-log and biostratigraphic dataset. In addition, the seismic interpretation applied advanced seismic interpretation software (PaleoScan™), which uses a patented model grid that links up seismic points and honours interpreted horizon constraints resulting in a seismic Relative Geological Time model. Standard seismic attributes, displayed upon horizons from a 3D RGT model of the chalk package, have shown to be very effective in the illustration and interpretation of complex chalk depositional features. Special attention has been focussed on mass waste deposits around inverted structures and salt diapirs. Several different mass waste complexes have been documented in 3D, illustrating a number of typical features such as

  19. Tech Labs.

    ERIC Educational Resources Information Center

    Lindeman, Cheryl A., Bishop, S. William

    1997-01-01

    Describes a seminar where students explore emerging technologies through a series of labs that help boost their technical skills and their confidence in using and managing technology. Discusses charting the course, laboratory logistics, technology tips, and benefits. (JRH)

  20. CONTROL TESTING OF THE UK NATIONAL NUCLEAR LABORATORY'S RADBALL TECHNOLOGY AT SAVANNAH RIVER NATIONAL LABORATORY

    SciTech Connect

    Farfan, E.

    2009-11-23

    The UK National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall (patent pending), which offers a means to locate and quantify radiation hazards and sources within contaminated areas of the nuclear industry. To date, the RadBall has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the UK. The trials have demonstrated the successful ability of the RadBall technology to be deployed and retrieved from active areas. The positive results from these initial deployment trials and the anticipated future potential of RadBall have led to the NNL partnering with the Savannah River National Laboratory (SRNL) to further underpin and strengthen the technical performance of the technology. RadBall consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. It has no power requirements and can be positioned in tight or hard-to reach places. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly less transparent, in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner which produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation maps provides information on the spatial distribution and strength of the sources in a given area forming a 3D characterization of the area of interest. This study completed at SRNL addresses key aspects of the testing of the RadBall technology. The first set of tests was performed at Savannah River Nuclear Solutions Health Physics Instrument Calibration Laboratory (HPICL) using various gamma-ray sources and an x-ray machine with known radiological characteristics. The objective of these preliminary tests was to identify the optimal dose and collimator thickness. The second set of tests involved a highly contaminated hot cell. The objective of

  1. Identifying Sources of Non-fallout Nuclear Contamination in Hudson River Sediments by Plutonium and Neptunium isotope ratios.

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.

    2002-12-01

    In an effort to identify and characterize nuclear contaminants released from sources contained within the Hudson River drainage basin, Pu isotopes and 237Np have been measured in a series of sediment cores collected from various locations within the region. During the last several decades, the Hudson River has received input of radioactive contamination from several sources. The first and most significant, has been global fallout, which was a result of atmospheric testing of nuclear weapons primarily by governments of the United States and Former Soviet Union in the 1950s and 1960s. The second, is contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River about 35 miles north of New York City. This facility began operation in 1962. A third source of radioactive contamination to the region is contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, which began operation in 1946. Our research entails identifying different sources of nuclear contamination by measurement of plutonium and neptunium isotopic ratios by inductively coupled plasma mass spectrometry (ICP-MS). The isotopic composition of a nuclear contaminant is a sensitive indicator of its origin. By comparing the isotopic composition measured in fluvial sediments to mean values reported for global fallout (i.e. 240Pu/239Pu = 0.18 ñ 0.014, 237Np/239Pu = 0.48 ñ 0.07, and 241Pu/239Pu = .00194 ñ 00028) it is possible to identify contaminants as non-fallout in origin. To date, we have analyzed selected samples from 3 sediment cores collected from the following locations: 1) the Mohawk River downstream of KAPL, 2) the Hudson River above its confluence with the Mohawk River, and 3) the lower Hudson River at a location in close proximity to IPNPP. Isotopic analysis of sediments from the Mohawk River indicates contamination that is clearly non-fallout in origin (240Pu/239Pu ranges between 0

  2. Investigation of cable deterioration in the containment building of the Savannah River Nuclear Reactor

    SciTech Connect

    Gillen, K.T.; Clough, R.L.; Jones, L.H.

    1982-08-01

    This report describes an investigation of the deterioration of polyethylene and polyvinylchloride cable materials which occurred in the containment building of the Savannah River nuclear reactor located at Aiken, South Carolina. Radiation dosimetry and temperature mapping data of the containment area indicated that the maximum dose experienced by the cable materials was only 2.5 Mrad at an average operating temperature of 43/sup 0/C. Considering this relatively moderate environment, the amount of material degradation seemed surprising. To understand these findings, an experimental program was performed on the commercial polyethylene and polyvinylchloride materials used at the plant to investigate their degradation behavior under combined ..gamma..-radiation and elevated temperature conditions. It is established that the material deterioration at the plant resulted from radiation-induced oxidation and that the degradation rate can be correlated with local levels of radiation intensity in the containment area.

  3. Baseline micronuclei and nuclear abnormalities frequencies in native fishes from the Paraná River (Argentina).

    PubMed

    Furnus, G N A; Caffetti, J D; García, E M; Benítez, M F; Pastori, M C; Fenocchio, A S

    2014-02-01

    This work aims to establish baseline frequencies of micronuclei (MN) and nuclear abnormalities (NA) in native fish species collected in situ from the Paraná River. For this purpose, the micronucleus test was applied in peripheral blood erythrocytes from specimens obtained from samplings collected at two localities (Posadas and Candelaria, Misiones, Argentina) during the period 2007-2010. The results were statistically analyzed using the Kruskal Wallis test. Data from nine fish species were obtained, among which Steindachnerina brevipinna (Characiformes) revealed the highest baseline frequency of MN and NA, showing statistically significant differences with regard to the other analyzed species. These results are the first report of baseline MN and NA frequencies for native fish species studied and could be useful for future comparisons with data of fishes belonging to other environments.

  4. Novel insights into Fukushima nuclear accident from isotopic evidence of plutonium spread along coastal rivers.

    PubMed

    Evrard, Olivier; Pointurier, Fabien; Onda, Yuichi; Chartin, Caroline; Hubert, Amélie; Lepage, Hugo; Pottin, Anne-Claire; Lefèvre, Irène; Bonté, Philippe; Laceby, J Patrick; Ayrault, Sophie

    2014-08-19

    The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident led to important releases of radionuclides into the environment, and trace levels of plutonium (Pu) were detected in northeastern Japan. However, measurements of Pu isotopic atom and activity ratios are required to differentiate between the contributions of global nuclear test fallout and FDNPP emissions. In this study, we used a double-focusing sector field ICP-MS to measure Pu atom and activity ratios in recently deposited sediment along rivers draining the most contaminated part of the inland radioactive plume. Results showed that plutonium isotopes (i.e., (239)Pu, (240)Pu, (241)Pu, and (242)Pu) were detected in all samples, although in extremely low concentrations. The (241)Pu/(239)Pu atom ratios measured in sediment deposits (0.0017-0.0884) were significantly higher than the corresponding values attributed to the global fallout (0.00113 ± 0.00008 on average for the Northern Hemisphere between 31°-71° N: Kelley, J. M.; Bond, L. A.; Beasley, T. M. Global distribution of Pu isotopes and (237)Np. Sci. Total. Env. 1999, 237/238, 483-500). The results indicated the presence of Pu from FDNPP, in slight excess compared to the Pu background from global fallout that represented up to ca. 60% of Pu in the analyzed samples. These results demonstrate that this radionuclide has been transported relatively long distances (∼45 km) from FDNPP and been deposited in rivers representing a potential source of Pu to the ocean. In future, the high (241)Pu/(239)Pu atom ratio of the Fukushima accident sourced-Pu should be measured to quantify the supply of continental-originating material from Fukushima Prefecture to the Pacific Ocean.

  5. Horizontal wells up odds for profit in Giddings Austin chalk

    SciTech Connect

    Maloy, W.T. )

    1992-02-17

    This paper reports on horizontal drilling in the Giddings field Austin chalk which has significantly improved average well recoveries and more than offset increased drilling costs. Although not the panacea originally promoted, horizontal drilling, in Giddings field, offers economic profits to the average investor. Economic analysis indicates that the typical investor is making money by earning returns in excess of market values. Field-wide development will, therefore, remain active unless oil prices or average well recoveries fall below $12/bbl or 112,000 bbl of oil equivalent (BOE), respectively. The application of technological innovation in the Giddings field may culminate in the drilling of over 2,000 horizontal Austin chalk wells, and has conceivably increased recoverable reserves by 400 million BOE.

  6. Movement of Water Through the Chalk Unsaturated zone

    NASA Astrophysics Data System (ADS)

    Butler, A.; Ireson, A.; Wheater, H.; Mathias, S.; Finch, J.

    2006-12-01

    Despite many decades study, quantification of water movement through the Chalk unsaturated zone has proved difficult, due to its particular properties. Chalk comprises a fine grained porous matrix intersected by a fracture network. In much of the unsaturated zone, for most of the time, matric potentials remain between -20 and -0.5 m. Thus the matrix is largely saturated by capillary action, and the fractures are largely de-watered. Therefore, debate has often focussed on the importance of the fractures, as compared with the matrix, for the movement of water. Recently, Mathias et al. (J Hydrol., in press) and Brouyère (J Contam Hydrol,82:195-219,2006) have (independently) proposed an Equivalent Continuum Model, ECM, for the Chalk. This assumes that the fractures can be treated as a porous medium and that the fracture and matrix domains can be treated as a single domain i.e. an equivalent continuum. This requires that the fractures and matrix are in pressure equilibrium, and whilst the theoretical basis for this assumption is reasonable, it has not been demonstrated empirically. In addition, Mathias et al. have demonstrated the importance of rainfall attenuation in the near surface weathered and soil zones of the Chalk for attenuating flow. As part of a national research initiative into groundwater dominated catchments, an extensive field monitoring programme has been implemented at two Chalk catchments in Berkshire (UK). This includes comprehensive soil moisture measurements (water content and matric potential), an extensive network of piezometers and observation wells measuring water table response, and the direct measurement of actual evaporation as well as standard meteorological variables, including rainfall. Using the Kosugi (WRR,32:2697-2703,1996) relationships for soil water retention and hydraulic conductivity a methodology for characterising vertical variation in hydraulic properties from competent chalk at depth through weathered rock to surface soil has

  7. Nonproliferation impacts assessment for the management of the Savannah River Site aluminum-based spent nuclear fuel

    SciTech Connect

    1998-12-01

    On May 13, 1996, the US established a new, 10-year policy to accept and manage foreign research reactor spent nuclear fuel containing uranium enriched in the US. The goal of this policy is to reduce civilian commerce in weapons-usable highly enriched uranium (HEU), thereby reducing the risk of nuclear weapons proliferation. Two key disposition options under consideration for managing this fuel include conventional reprocessing and new treatment and packaging technologies. The Record of Decision specified that, while evaluating the reprocessing option, ``DOE will commission or conduct an independent study of the nonproliferation and other (e.g., cost and timing) implications of chemical separation of spent nuclear fuel from foreign research reactors.`` DOE`s Office of Arms Control and Nonproliferation conducted this study consistent with the aforementioned Record of Decision. This report addresses the nonproliferation implications of the technologies under consideration for managing aluminum-based spent nuclear fuel at the Savannah River Site. Because the same technology options are being considered for the foreign research reactor and the other aluminum-based spent nuclear fuels discussed in Section ES.1, this report addresses the nonproliferation implications of managing all the Savannah River Site aluminum-based spent nuclear fuel, not just the foreign research reactor spent nuclear fuel. The combination of the environmental impact information contained in the draft EIS, public comment in response to the draft EIS, and the nonproliferation information contained in this report will enable the Department to make a sound decision regarding how to manage all aluminum-based spent nuclear fuel at the Savannah River Site.

  8. Study of a conceptual nuclear energy center at Green River, Utah. Final summary report

    SciTech Connect

    Williams, J.T.

    1982-09-01

    This document summarizes a conceptual study on the feasibility and practicality of developing a nuclear energy center (NEC) at a representative Western site. The site selected for this conceptual study, an area of about 50 square miles, is located 15 miles south of Green River, Utah. The conceptual NEC would consist of nine nuclear electric generating units, arranged on the site in three clusters of three reactors each (triads), separated by about 2 1/2 miles. Of the total electric output of 11,250 MWe that the NEC could produce, about 82% is assumed to be transmitted out of Utah to Colorado, New Mexico, Arizona, Nevada, and California. The technical engineering issues studied included geology and seismology, plant design, low-level radioactive waste disposal, transmission, and construction schedules and costs. Socioeconomic issues included were demographics, land use, community service needs, and fiscal impacts. Environmental considerations included terrestrial and aquatic ecology, visual impact, and secondary population impacts. Radiological issues were concerned with the safety and risks of an NEC and an on-site low-level waste facility. Institutional issues included methods of ownership, taxation, implications of energy export, and water allocation. The basic finding was that an NEC would be technically feasible, but a number of socioeconomic and institutional issues would require resolution before a Western regional NEC could be considered a viable power plant siting option.

  9. Why Chalk Breaks into Three Pieces When Dropped

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2015-01-01

    It has been the author's experience over many years, no doubt shared by others, that a stick of chalk usually breaks into three pieces when accidentally dropped onto the floor. I rarely gave it any thought, apart from noting that the fundamental mode of vibration of a freely supported, rigid rod has two nodes at an equal distance from each end. For example, a baseball bat has a node in the barrel (the sweet spot) about 15 cm from the end and another node in the handle. However, chalk is not expected to break at the node points, since maximum stress arises at the antinode in the middle of the chalk where bending is a maximum. Richard Feynman described a similar problem with long sticks of spaghetti.1 He found that they always break into three or more pieces when bent slowly beyond their breaking point, rather than simply breaking in half. He was unable to figure out why, although the problem was solved many years later2 and is nicely illustrated by Vollmer and Mollmann.3

  10. Diffraction Seismic Imaging of the Chalk Group Reservoir Rocks

    NASA Astrophysics Data System (ADS)

    Montazeri, M.; Fomel, S.; Nielsen, L.

    2016-12-01

    In this study we investigate seismic diffracted waves instead of seismic reflected waves, which are usually much stronger and carry most of the information regarding subsurface structures. The goal of this study is to improve imaging of small subsurface features such as faults and fractures. Moreover, we focus on the Chalk Group, which contains important groundwater resources onshore and oil and gas reservoirs in the Danish sector of the North Sea. Finding optimum seismic velocity models for the Chalk Group and estimating high-quality stacked sections with conventional processing methods are challenging tasks. Here, we try to filter out as much as possible of undesired arrivals before stacking the seismic data. Further, a plane-wave destruction method is applied on the seismic stack in order to dampen the reflection events and thereby enhance the visibility of the diffraction events. After this initial processing, we estimate the optimum migration velocity using diffraction events in order to obtain a better resolution stack. The results from this study demonstrate how diffraction imaging can be used as an additional tool for improving the images of small-scale features in the Chalk Group reservoir, in particular faults and fractures. Moreover, we discuss the potential of applying this approach in future studies focused on such reservoirs.

  11. Horizontal technology helps spark Louisiana`s Austin chalk trend

    SciTech Connect

    Koen, A.D.

    1996-04-29

    A handful of companies paced by some of the most active operators in the US are pressing the limits of horizontal technology to ramp up Cretaceous Austin chalk exploration and development (E and D) across Louisiana. Companies find applications in Louisiana for lessons learned drilling horizontal wells to produce chalk intervals in Texas in Giddings, Pearsall, and Brookeland fields. Continuing advances in horizontal well technology are helping operators deal with deeper, hotter reservoirs in more complex geological settings that typify the chalk in Louisiana. Better horizontal drilling, completion, formation evaluation, and stimulation techniques have enabled operators to produce oil and gas from formations previously thought to be uneconomical. Most of the improved capabilities stem from better horizontal tools. Horizontal drilling breakthroughs include dual powered mud motors and retrievable whipstocks, key links in the ability to drill wells with more than one horizontal lateral. Better geosteering tools have enabled operators to maintain horizontal wellbores in desired intervals by signaling bit positions downhole while drilling. This paper reviews the technology and provides a historical perspective on the various drilling programs which have been completed in this trend. It also makes predictions on future drilling successes.

  12. Maternal Geophagy of Calabash Chalk on Foetal Cerebral Cortex Histomorphology

    PubMed Central

    EKANEM, Theresa Bassey; EKONG, Moses Bassey; ELUWA, Mokutima Amarachi; IGIRI, Anozeng Oyono; OSIM, Eme Efiom

    2015-01-01

    Background: Calabash chalk, a kaolin-base substance is a common geophagic material mostly consumed by pregnant women. This study investigated its effect on the histomorphology of the foetal cerebral cortex. Methods: Twelve gestating Wistar rats were divided equally into groups 1 and 2. On pregnancy day seven (PD7), group 2 animals were administered 200 mg/kg body weight of calabash chalk suspension, while group 1 animals served as the control and received 1 ml of distilled water, by oral gavages and for 14 days (PD7-PD20). On PD21, the dams were sacrificed, and the foetuses removed, examined for gross malformations, weighed and culled to two foetuses per mother. Their whole brains were excised, weighed and preserved using 10% buffered formalin, and routinely processed by haematoxylin and eosin, and Luxol fast blue methods. Results: The foetuses showed no morphological change, but their mean body weights was higher (p=0.0001). Histomorphological sections of the cerebral cortex showed hypertrophy and hyperplasia of cells in all the cortical layers, with less demonstrated Nissl and higher (p=0.001) cellular population compared with the control group. Conclusion: Calabash chalk cause body weight increase and histomorphological changes in the cerebral cortex of foetuses. PMID:26715904

  13. Comparison of balance of tritium activity in waste water from nuclear power plants and at selected monitoring sites in the Vltava River, Elbe River and Jihlava (Dyje) River catchments in the Czech Republic.

    PubMed

    Hanslík, Eduard; Marešová, Diana; Juranová, Eva; Sedlářová, Barbora

    2017-12-01

    During the routine operation, nuclear power plants discharge waste water containing a certain amount of radioactivity, whose main component is the artificial radionuclide tritium. The amounts of tritium released into the environment are kept within the legal requirements, which minimize the noxious effects of radioactivity, but the activity concentration is well measurable in surface water of the recipient. This study compares amount of tritium activity in waste water from nuclear power plants and the tritium activity detected at selected relevant sites of surface water quality monitoring. The situation is assessed in the catchment of the Vltava and Elbe Rivers, affected by the Temelín Nuclear Power Plant as well as in the Jihlava River catchment (the Danube River catchment respectively), where the waste water of the Dukovany Nuclear Power Plant is discharged. The results show a good agreement of the amount of released tritium stated by the power plant operator and the tritium amount detected in the surface water and highlighted the importance of a robust independent monitoring of tritium discharged from a nuclear power plant which could be carried out by water management authorities. The outputs of independent monitoring allow validating the values reported by a polluter and expand opportunities of using tritium as e.g. tracer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Biological Removal of Particles During Chalk-Ex: Results of Shipboard Bottle Experiments

    NASA Astrophysics Data System (ADS)

    McManus, G. B.; Dam, H. G.; Smith, A. N.

    2002-12-01

    As part of the Chalk-Ex program, 13 tons of powdered Cretaceous chalk were dispersed into a patch of about 1.5 km2 in the NW Atlantic Ocean in November 2001. The chalk patch was then followed for several days while physical properties of the water were measured. A series of related abstracts details those results. To estimate the possible role of grazing zooplankton in removal of the chalk, we conducted five bottle incubations on deck while the patch was being followed. Experiments consisted of four treatments. For all treatments, one-liter polycarbonate bottles were filled with water pre-screened through 200 um mesh by reverse flow. Three of the treatments received added mesozooplankton in successively greater multiples of the natural abundance, up to c. 32x.. The experiments were designed to look for evidence of microzooplankton grazing (removal of chalk-sized particles in the <200 um treatment) and either top-down control by mesozooplankton (grazing on chalk-sized particles declines as mesozooplankton concentration increases) or direct mesozooplankton grazing (grazing on chalk-sized particles increases with mesozooplankton concentration). Abundance of chalk-sized particles (1.3-3.5 um) was measured with an Elzone particle counter at initial and final (c. 20h) experimental times. We also had formalin-killed controls, but they showed evidence of particle production during the experiments, most likely due to mineral precipitation of the preservative's buffer, and were thus difficult to interpret. Net per capita rates of change for chalk-sized particles ranged from -0.89 to +0.47 d-1 in the <200 um treatment during the five experiments. Three of the five experiments showed evidence of top-down control on microzooplankton grazing. Because the chalk size-fraction also contained bacterioplankton, which presumably was growing during the incubations, any net losses would provide minimal estimates of potential grazing on chalk. For several experiments, chalk particles

  15. Genetic structure of Populus hybrid zone along the Irtysh River provides insight into plastid-nuclear incompatibility

    PubMed Central

    Zeng, Yan-Fei; Zhang, Jian-Guo; Duan, Ai-Guo; Abuduhamiti, Bawerjan

    2016-01-01

    In plants, the maintenance of species integrity despite hybridization has often been explained by the co-adaption of nuclear gene complexes. However, the interaction between plastid and nuclear sub-genomes has been underestimated. Here, we analyzed the genetic structure of a Populus alba and P. tremula hybrid zone along the Irtysh River system in the Altai region, northwest China, using both nuclear microsatellites and plastid DNA sequences. We found high interspecific differentiation, although the hybrid P. × canescens was prevalent. Bayesian inference classified most hybrids into F1, followed by a few back-crosses to P. alba, and fewer F2 hybrids and back-crosses to P. tremula, indicating a few introgressions but preference toward P. alba. When plastid haplotypes in parental species were distinct, P. × canescens carried the haplotypes of both parents, but showed significant linkage between intraspecific haplotype and nuclear genotypes at several microsatellite loci. Selection, rather than migration and assortative mating, might have contributed to such plastid-nuclear disequilibria. By removing later-generated hybrids carrying interspecific combinations of haplotype and nuclear genotypes, plastid-nuclear incompatibility has greatly limited the gene exchange between P. alba and P. tremula via backcrossing with hybrids, demonstrating a significant association between plastid haplotype and the proportion of nuclear admixture. PMID:27306416

  16. Labs: 1987.

    ERIC Educational Resources Information Center

    Igelsrud, Don, Ed.

    1988-01-01

    This article presents a variety of topics discussed in this column and at a biology teachers' workshop concerning the quality and value of lab techniques used for teaching high school biology. Topics included are Drosophila salivary glands, sea urchins, innovations, dyes and networking. (CW)

  17. Labs: 1987.

    ERIC Educational Resources Information Center

    Igelsrud, Don, Ed.

    1988-01-01

    This article presents a variety of topics discussed in this column and at a biology teachers' workshop concerning the quality and value of lab techniques used for teaching high school biology. Topics included are Drosophila salivary glands, sea urchins, innovations, dyes and networking. (CW)

  18. Reading Lab.

    ERIC Educational Resources Information Center

    Burt, Lorna

    This guide is intended for use in conducting a reading lab for a broad group of workers ranging from nonreaders to persons reading at a fifth-grade level. Presented first is a course overview that includes the following: information on the course's targeted population, student selection process, and demographics; strategies for adult remediation;…

  19. Site-wide seismic risk model for Savannah River Site nuclear facilities

    SciTech Connect

    Eide, S.A.; Shay, R.S.; Durant, W.S.

    1993-09-01

    The 200,000 acre Savannah River Site (SRS) has nearly 30 nuclear facilities spread throughout the site. The safety of each facility has been established in facility-specific safety analysis reports (SARs). Each SAR contains an analysis of risk from seismic events to both on-site workers and the off-site population. Both radiological and chemical releases are considered, and air and water pathways are modeled. Risks to the general public are generally characterized by evaluating exposure to the maximally exposed individual located at the SRS boundary and to the off-site population located within 50 miles. Although the SARs are appropriate methods for studying individual facility risks, there is a class of accident initiators that can simultaneously affect several of all of the facilities, Examples include seismic events, strong winds or tornados, floods, and loss of off-site electrical power. Overall risk to the off-site population from such initiators is not covered by the individual SARs. In such cases multiple facility radionuclide or chemical releases could occur, and off-site exposure would be greater than that indicated in a single facility SAR. As a step towards an overall site-wide risk model that adequately addresses multiple facility releases, a site-wide seismic model for determining off-site risk has been developed for nuclear facilities at the SRS. Risk from seismic events up to the design basis earthquake (DBE) of 0.2 g (frequency of 2.0E-4/yr) is covered by the model. Present plans include expanding the scope of the model to include other types of initiators that can simultaneously affect multiple facilities.

  20. The new Wallula CO2 project may revive the old Columbia River Basalt (western USA) nuclear-waste repository project

    NASA Astrophysics Data System (ADS)

    Schwartz, Michael O.

    2017-07-01

    A novel CO2 sequestration project at Wallula, Washington, USA, makes ample use of the geoscientific data collection of the old nuclear waste repository project at the Hanford Site nearby. Both projects target the Columbia River Basalt (CRB). The new publicity for the old project comes at a time when the approach to high-level nuclear waste disposal has undergone fundamental changes. The emphasis now is on a technical barrier that is chemically compatible with the host rock. In the ideal case, the waste container is in thermodynamic equilibrium with the host-rock groundwater regime. The CRB groundwater has what it takes to represent the ideal case.

  1. Survey of potential process-heat and reject-heat utilization at a Green River nuclear-energy center

    SciTech Connect

    Jensen, C.M.; Sandquist, G.M.

    1982-03-01

    Potential uses of process heat and reject heat from a nuclear-energy center at Green River, Utah have been investigated. The remoteness of the Green River site would preclude many potential industrial uses for economical reasons such as transportation costs and lack of local markets. Water-consumption requirements would also have serious impact on some applications due to limitations imposed by other contractual agreements upon the water in the region. Several processes were identified which could be considered for the Green River site; including the use of heat to separate bitumens from tar sands, district heating, warming of greenhouses and soil, and the production of fish for game and commercial sales. The size of these industries would be limited and no single process or industry can be identified at this time which could use the full amount of low-temperature reject heat that would be generated at a NEC.

  2. Fault zone processes in mechanically layered mudrock and chalk

    NASA Astrophysics Data System (ADS)

    Ferrill, David A.; Evans, Mark A.; McGinnis, Ronald N.; Morris, Alan P.; Smart, Kevin J.; Wigginton, Sarah S.; Gulliver, Kirk D. H.; Lehrmann, Daniel; de Zoeten, Erich; Sickmann, Zach

    2017-04-01

    A 1.5 km long natural cliff outcrop of nearly horizontal Eagle Ford Formation in south Texas exposes northwest and southeast dipping normal faults with displacements of 0.01-7 m cutting mudrock, chalk, limestone, and volcanic ash. These faults provide analogs for both natural and hydraulically-induced deformation in the productive Eagle Ford Formation - a major unconventional oil and gas reservoir in south Texas, U.S.A. - and other mechanically layered hydrocarbon reservoirs. Fault dips are steep to vertical through chalk and limestone beds, and moderate through mudrock and clay-rich ash, resulting in refracted fault profiles. Steeply dipping fault segments contain rhombohedral calcite veins that cross the fault zone obliquely, parallel to shear segments in mudrock. The vertical dimensions of the calcite veins correspond to the thickness of offset competent beds with which they are contiguous, and the slip parallel dimension is proportional to fault displacement. Failure surface characteristics, including mixed tensile and shear segments, indicate hybrid failure in chalk and limestone, whereas shear failure predominates in mudrock and ash beds - these changes in failure mode contribute to variation in fault dip. Slip on the shear segments caused dilation of the steeper hybrid segments. Tabular sheets of calcite grew by repeated fault slip, dilation, and cementation. Fluid inclusion and stable isotope geochemistry analyses of fault zone cements indicate episodic reactivation at 1.4-4.2 km depths. The results of these analyses document a dramatic bed-scale lithologic control on fault zone architecture that is directly relevant to the development of porosity and permeability anisotropy along faults.

  3. Groundwater recharge dynamics in unsaturated fractured chalk: a case study

    NASA Astrophysics Data System (ADS)

    Cherubini, Claudia; Pastore, Nicola; Giasi, Concetta I.; Allegretti, Nicolaetta M.

    2016-04-01

    The heterogeneity of the unsaturated zone controls its hydraulic response to rainfall and the extent to which pollutants are delayed or attenuated before reaching groundwater. It plays therefore a very important role in the recharge of aquifers and the transfer of pollutants because of the presence of temporary storage zones and preferential flows. A better knowledge of the physical processes in the unsaturated zone would allow an improved assessment of the natural recharge in a heterogeneous aquifer and of its vulnerability to surface-applied pollution. The case study regards the role of the thick unsaturated zone of the Cretaceous chalk aquifer in Picardy (North of France) that controls the hydraulic response to rainfall. In the North Paris Basin, much of the recharge must pass through a regional chalk bed that is composed of a porous matrix with embedded fractures. Different types of conceptual models have been formulated to explain infiltration and recharge processes in the unsaturated fractured rock. The present study analyses the episodic recharge in fractured Chalk aquifer using the kinematic diffusion theory to predict water table fluctuation in response to rainfall. From an analysis of the data, there is the evidence of 1) a seasonal behavior characterized by a constant increase in the water level during the winter/spring period and a recession period, 2) a series of episodic behaviors during the summer/autumn. Kinematic diffusion models are useful for predict preferential fluxes and dynamic conditions. The presented approach conceptualizes the unsaturated flow as a combination of 1) diffusive flow refers to the idealized portion of the pore space of the medium within the flow rate is driven essentially by local gradient of potential; 2) preferential flow by which water moves across macroscopic distances through conduits of macropore length.

  4. Fractal characterization of a fractured chalk reservoir - The Laegerdorf case

    SciTech Connect

    Stoelum, H.H.; Koestler, A.G.; Feder, J.; Joessang, T.; Aharony, A.

    1991-03-01

    What is the matrix block size distribution of a fractured reservoir In order to answer this question and assess the potential of fractal geometry as a method of characterization of fracture networks, a pilot study has been done of the fractured chalk quarry in Laegerdorf. The fractures seen on the quarry walls were traced in the field for a total area of {approximately}200 {times} 45 m. The digitized pictures have been analyzed by a standard box-counting method. This analysis gave a fractal dimension of similarity varying from 1.33 for fractured areas between faults, to 1.43 for the fault zone, and 1.53 for the highly deformed fault gouge. The amplitude showed a similar trend. The fractal dimension for the whole system of fractures is {approximately}1.55. In other words, fracture networks in chalk have a nonlinear, fractal geometry, and so matrix block size is a scaling property of chalk reservoirs. In terms of rock mechanics, the authors interpret the variation of the fractal dimension as follows: A small fractal dimension and amplitude are associated with brittle deformation in the elastic regime, while a large fractal dimension and amplitude are associated with predominantly ductile, strain softening deformation in the plastic regime. The interaction between the two regimes of deformation in the rock body is a key element of successful characterization and may be approached by seeing the rock as a non-Newtonian viscoelastic medium. The fractal dimension for the whole is close to a material independent limit that constrains the development of fractures.

  5. Mechanisms for surface contamination of soils and bottom sediments in the Shagan River zone within former Semipalatinsk Nuclear Test Site.

    PubMed

    Aidarkhanov, A O; Lukashenko, S N; Lyakhova, O N; Subbotin, S B; Yakovenko, Yu Yu; Genova, S V; Aidarkhanova, A K

    2013-10-01

    The Shagan River is the only surface watercourse within the former Semipalatinsk Test Site (STS). Research in the valley of the Shagan River was carried out to study the possible migration of artificial radionuclides with surface waters over considerable distances, with the possibility these radionuclides may have entered the Irtysh River. The investigations revealed that radioactive contamination of soil was primarily caused by the first underground nuclear test with soil outburst conducted at the "Balapan" site in Borehole 1004. The surface nuclear tests carried out at the "Experimental Field" site and global fallout made insignificant contributions to contamination. The most polluted is the area in the immediate vicinity of the "Atomic" Lake crater. Contamination at the site is spatial. The total area of contamination is limited to 10-12 km from the crater piles. The ratio of plutonium isotopes was useful to determine the source of soil contamination. There was virtual absence of artificial radionuclide migration with surface waters, and possible cross-border transfer of radionuclides with the waters of Shagan and Irtysh rivers was not confirmed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Sulfur isotope patterns of iron sulfide and barite nodules in the Upper Cretaceous Chalk of England and their regional significance in the origin of coloured chalks

    NASA Astrophysics Data System (ADS)

    Jeans, Christopher V.; Turchyn, Alexandra V.; Hu, Xu-Fang

    2016-06-01

    The relationship between the development of iron sulfide and barite nodules in the Cenomanian Chalk of England and the presence of a red hematitic pigment has been investigated using sulfur isotopes. In southern England where red and pink chalks are absent, iron sulfide nodules are widespread. Two typical large iron sulfide nodules exhibit δ34S ranging from -48.6‰ at their core to -32.6‰ at their outer margins. In eastern England, where red and pink chalks occur in three main bands, there is an antipathetic relationship between the coloured chalks and the occurrence of iron sulfide or barite nodules. Here iron sulfide, or its oxidised remnants, are restricted to two situations: (1) in association with hard grounds that developed originally in chalks that contained the hematite pigment or its postulated precursor FeOH3, or (2) in regional sulfidization zones that cut across the stratigraphy. In the Cenomanian Chalk exposed in the cliffs at Speeton, Yorkshire, pyrite and marcasite (both iron sulfide) nodules range in δ34S from -34.7‰ to +40.0‰. In the lower part of the section δ34S vary from -34.8‰ to +7.8‰, a single barite nodule has δ34S between +26.9‰ and +29.9‰. In the middle part of the section δ34S ranges from +23.8‰ to +40.0‰. In the sulfidization zones that cut across the Cenomanian Chalk of Lincolnshire the iron sulfide nodules are typically heavily weathered but these may contain patches of unoxidised pyrite. In these zones, δ34S ranges from -32.9‰ to +7.9‰. The cross-cutting zones of sulfidization in eastern England are linked to three basement faults - the Flamborough Head Fault Zone, the Caistor Fault and the postulated Wash Line of Jeans (1980) - that have affected the deposition of the Chalk. It is argued that these faults have been both the conduits by which allochthonous fluids - rich in hydrogen sulfide/sulfate, hydrocarbons and possibly charged with sulfate-reducing bacteria - have penetrated the Cenomanian Chalk as

  7. Fluxes of radiocaesium associated with suspended sediment in rivers impacted by the Fukushima Daiichi Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Smith, Hugh; Blake, Will; Onda, Yuichi; Yoshimura, Kazuya; Taniguchi, Keisuke; Yamashiki, Yosuke; Matsuura, Yuki; Taylor, Alex

    2014-05-01

    The Fukushima Daiichi Nuclear Power Plant accident which followed the earthquake and tsunami on 11 March 2011 resulted in the release of Cs-134 and Cs-137 into the surrounding environment, where highly elevated levels are reported. There is considerable concern about the redistribution of these radioactive contaminants from the atmosphere to vegetation, soil and aquatic systems. Fluvial redistribution of radiocaesium may contaminate downstream areas that were subject to low fallout and deliver significant quantities of highly contaminated fine sediment to the coastal zone. This study reports on the magnitude of fluvial transfer of Cs-134 and Cs-137 through river networks located across the fallout region. Initially six nested river monitoring stations were established within the Abukuma River basin from June 2011. Subsequently, an additional 23 stations were established between October 2012 and January 2013, which included stations within the Abukuma basin as well as smaller coastal catchments north and south of the power plant. Combined, these 29 sites represent a globally-unique river monitoring network designed to quantify sediment-associated transfer of radiocaesium from headwaters to the Pacific Coast of Japan. The catchments range in area from 8 to 5,172 km2 and span a large range in spatially-averaged radiocaesium inventories. Flow and turbidity (converted to suspended sediment concentration) were measured at each station while bulk suspended sediment samples were collected at regular intervals using time-integrated samplers to allow measurement of Cs-134 and Cs-137 activity concentrations by gamma spectrometry. Preliminary monitoring data showed highly elevated but also highly variable fluxes of radiocaesium in rivers across the fallout region. High magnitude flows in response to typhoon events exported large quantities of radiocaesium. Rivers are an important and continuing source of radiocaesium input to the coastal environment and the Pacific Ocean in

  8. A geological assessment: What`s ahead for Louisiana Austin chalk

    SciTech Connect

    Maloy, W.T.

    1997-06-02

    Both noteworthy and recent, the extension of the Austin chalk horizontal drilling play into Louisiana has been as closely watched as it has been controversial. The play has been controversial for the critics who claim the Louisiana chalk boom is simply the latest chapter in the chalk`s boom and bust history. The play is closely watched by chalk enthusiasts who have seen Louisiana horizontal wells yield as much as 80,000 bbl of oil and 250 MMcf of gas in a single month. Who is right? How will the play develop? This article presents a geological assessment of the play and offers some insights into the future of horizontal drilling in Louisiana.

  9. A unique Austin Chalk reservoir, Van field, Van Zandt County, Texas

    SciTech Connect

    Lowe, J.T. )

    1990-09-01

    Significant shallow oil production from the Austin Chalk was established in the Van field, Van Zandt County, in East Texas in the late 1980s. The Van field structure is a complexly faulted domal anticline created by salt intrusion. The Woodbine sands, which underlie the Austin Chalk, have been and continue to be the predominant reservoir rocks in the field. Evidence indicates that faults provided vertical conduits for migration of Woodbine oil into the Austin Chalk where it was trapped along the structural crest. The most prolific Austin Chalk production is on the upthrown side of the main field fault, as is the Woodbine. The Austin Chalk is a soft, white to light gray limestone composed mostly of coccoliths with some pelecypods. Unlike the Austin Chalk in the Giddings and Pearsall fields, the chalk at Van was not as deeply buried and therefore did not become brittle and susceptible to tensional or cryptic fracturing. The shallow burial in the Van field was also important in that it allowed the chalk to retain primary microporosity. The production comes entirely from this primary porosity. In addition to the structural position and underlying oil source from the Woodbine, the depositional environment and associated lithofacies are also keys to the reservoir quality in the Van field as demonstrated by cores from the upthrown and downthrown (less productive) sides of the main field fault. It appears that at the time of Austin Chalk deposition, the main field fault was active and caused the upthrown side to be a structural high and a more agreeable environment for benthonic organisms such as pelecypods and worms. The resulting bioturbation enhanced the reservoir's permeability enough to allow migration and entrapment of the oil. Future success in exploration for analogous Austin Chalk reservoirs will require the combination of a favorable environment of deposition, a nearby Woodbine oil source, and a faulted trap that will provide the conduit for migration.

  10. Analysis on radiocesium concentration in rivers that have catchment areas affected by the fallout from Fukushima Daiichi Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Taniguchi, Keisuke; Yoshimura, Kazuya; Sakaguchi, Aya; Yamamoto, Masayoshi; Onda, Yuichi

    2014-05-01

    Due to Fukushima Daiichi Nuclear Power Plant accident, radioactive materials including Cs-134 and Cs-137 were widely distributed in surrounded area. The radiocesiums have been transported in river networks. This study showed the monitoring results of radiocesium concentration in river waters and suspended sediments in Abukuma river basin and smaller coastal river catchments. The monitoring started at 6 sites from June 2011. Subsequently, additional 24 monitoring sites were installed between October 2012 and January 2013. Flow and turbidity (for calculation of suspended sediment concentration) were measured at each site, while suspended sediments and river water were collected every one or half month to measure Cs-134 and Cs-137 activity concentrations by gamma spectrometry. Activity concentrations of Cs-134 and Cs- 137 on suspended sediments were generally decreasing at all sites. The decreasing rate changed lower at about one year later from the accident. Activity concentration in river waters also showed the same tendency although there are only few data within 1 year from the accident. Activity concentrations measured at the same day are proportional to the mean catchment inventory. Therefore, the activity concentration can be normalized by the mean catchment inventory. The normalized activity can be fitted to following double exponential function: [At] = 1.551 exp (-5.265t) + 0.069 exp (-0.266 t), where t [year] is the time from the accident. There is no time evolution of Kd between suspended sediments and river water. Instead, Kd was varied spatially. Although the reason of the spatial variation is not clear for now, geology of the catchment (i.e. mineral composition of suspended particles) seems to relate to the variation.

  11. Chalk Point auxiliary pump study: 1981. Final report

    SciTech Connect

    Hirshfield, M.F.; Hixson, J.H. III; Perry, E.S.

    1982-03-26

    In July 1981, the Academy of Natural Sciences of Philadelphia undertook a study to examine the numbers of finfish and blue crabs (Callinectes sapidus) entrained through the auxiliary cooling pumps at the Chalk Point Steam Electric Station (SES) operated by the Potomac Electric Power Company. Samples were collected by positioning a net attached to a hinged steel frame directly in the discharge of the auxiliary pumps. Concurrently, impingement rates of fish and blue crabs on the travelling screens were estimated by collecting the organisms washed into the troughs that lead to the discharge canal. A total of 6673 fish and blue crabs, representing 13 species, was collected in auxiliary pump samples at the Chalk Point generating station during July and August 1981. A total of 2154 fish and blue crabs representing seven species was collected in concurrent impingement samples. Blue crabs represented almost all of the total. The numbers of individuals entrained through auxiliary pumps showed a diel effect, with most individuals entrained at night.

  12. Horizontal gas-condensate find brightens Louisiana chalk outlook

    SciTech Connect

    Petzet, G.A.

    1994-12-19

    A ray of hope may have appeared in the Louisiana portion of the Cretaceous Austin chalk trend after several years of expensive disappointment. OXY USA Inc. plans to use dual leg horizontal wells to develop a fracture chalk reservoir named Masters Creek field in Rapides Parish. The state has approved four 1,920 acre spacing units, one of which contains OXY's A1 Monroe well. The A1 Monroe flowed 6.6 MMcfd of gas with 2,162 b/d of 48[degree] gravity condensate, not oil as previously reported, through a 26/64 in. choke with 6,196 psi flowing tubing pressure from a single southward 4,000 ft horizontal leg at 14,803 ft true vertical depth. Bottomhole pressure is 13,100 psi. OXY called A1 Monroe a significant discovery and said it has additional exploration acreage blocks along the trend. Louisiana exempts production from horizontal wells from state severance tax until all project costs are returned. The paper briefly discusses OXY's program.

  13. Determining Sources and Transport of Nuclear Contamination in Hudson River Sediments with Plutonium, Neptunium, and Cesium isotope ratios

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.; Chaky, D. A.; Simpson, H. J.; McHugh, C. M.; Shuster, E. L.; Bopp, R. F.

    2004-12-01

    Different sources of radioactive contamination contain characteristic and identifiable isotopic signatures, which can be used to study sediment transport. We focus on Pu-239, Pu-240, Np-237 and Cs-137, which are strongly bound to fine grained sediments. The Hudson River drainage basin has received contamination from at least three separate sources: 1) global fallout from atmospheric testing of nuclear weapons, which contributed Pu, Np and Cs; 2) contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River Estuary ˜70km north of New York Harbor, where records document releases of Cs-137; 3) contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, where incomplete records document releases of Cs-137 but no mention is made of Pu or Np. Here we report measurements of Pu isotopes, Np-237 and Cs-137 for a series of sediment cores collected from various locations within the drainage basin: 1) Mohawk River downstream of KAPL, 2) Hudson River upstream of its confluence with the Mohawk River, and 3) lower Hudson River at a location in close proximity to IPNPP. In addition, we present data from selected samples from two other lower Hudson River locations: One site located ˜30km downstream of IPNPP and another ˜30km upstream of IPNPP. By comparing the isotopic ratios Pu-240/Pu-239, Np-237/Pu-239, and Cs-137/Pu-239, measured in fluvial sediments to mean global fallout values, it is possible to identify and resolve different sources of non-fallout contamination. To date, isotopic data for sediments indicate non-fallout sources of Pu-239, Pu-240, and Cs-137; Np-237, however, appears to originate from global fallout only. Mohawk River sediments downstream of KAPL exhibit enrichments in Pu-239, Pu-240, and Cs-137 that are 7 to 20 times higher than levels expected from global fallout as indicated from Np-237. The elevated levels, non-fallout isotopic signatures

  14. Characteristics of radiocesium runoff between five river basins near to the Fukushima Daiichi Nuclear Power Plant over heavy rainfall events

    NASA Astrophysics Data System (ADS)

    Sakuma, Kazuyuki; Malins, Alex; Kurikami, Hiroshi; Kitamura, Akihiro

    2017-04-01

    Due to the Fukushima Daiichi Nuclear Power Plant accident triggered by the earthquake and subsequent tsunami on 11 March 2011, many radionuclides were released into environments such as forests, rivers, dam reservoirs, and the ocean. 137Cs is one of the most important radio-contaminants. In order to investigate 137Cs transport and discharge from contaminated basins, in this study we developed a three dimensional model of five river basins near to the Fukushima Daiichi Nuclear Power Plant. We applied the General-purpose Terrestrial fluid-Flow Simulator (GETFLOWS) watershed code to the Odaka, Ukedo, Maeda, Kuma, and Tomioka River basins. The main land uses in these areas are forests, rice paddy fields, crop fields and urban. The Ukedo, Kuma and Tomioka Rivers have relatively large dam reservoirs (>106 m3) in the upper basins. The radiocesium distribution was initiated based on the Second Airborne Monitoring Survey. The simulation periods were 2011 Typhoon Roke, nine heavy rainfall events in 2013, Typhoons Man-yi and Wipha, and tropical storm Etau in 2015. Water, sediment, and radiocesium discharge from the basins was calculated for these events. The characteristics of 137Cs runoff between the different basins were evaluated in terms of land use, the effect of dam reservoirs, geology, and the fraction of the initial radiocesium inventory discharged. The absolute 137Cs discharge from the Ukedo River basin was highest, however the 137Cs discharge ratio was lowest due to the Ogaki Dam and the inventory being mainly concentrated in upstream forests. The results for the water, suspended sediment and radiocesium discharge as a function of total precipitation over the various rainfall events can be used to predict discharges for other typhoons.

  15. Laboratory determination of effective stress laws for deformation and permeability of chalk

    SciTech Connect

    Teufel, L W; Warpinski, N R

    1990-01-01

    Laboratory deformation and permeability measurements have been made on chalk samples from Ekofisk area fields as a function of confining stress and pore pressure to determine the effective stress laws for chalk. An understanding of the effective stress law is essential to obtain correct reservoir-property data from core analysis and is critical for reservoir management studies and reservoir compaction models. A powerful statistical technique known as the response surface method has been used to analyze our laboratory data determine the form of the effective stress law for deformation and permeability. Experiments were conducted on chalk samples that had a range of porosities from 15% to 36%, because porosity is the dominant intrinsic property that effects deformation and permeability behavior of chalk. Deformation of a 36% porosity chalk was highly nonlinear, but the effective stress law was linear, with {alpha} equal to about unity. Lower-porosity samples showed linear strain behavior and a linear effective stress law with {alpha} as low as 0.74. Analysis of the effective stress law for permeability is presented only for the lowest porosity chalk sample because changes in permeability in the higher-porosity chalk samples due to increasing confining stress or pore pressure were not were large enough, to deduce meaningful effective stress relationships. 15 refs., 8 figs., 2 tabs.

  16. Chalk as the carrier for nitrifying biofilm in a fluidized bed reactor.

    PubMed

    Green, M; Ruskol, Y; Lahav, O; Tarre, S

    2001-01-01

    A fluidized bed reactor for nitrification with chalk as the biomass carrier and the sole buffer agent was studied. Chalk dissolution in the reactor was found to follow the stoichiometric ratio of 1 mole of CaCO3 dissolved for each mole of NH4+ oxidized. Three batches of chalk, each one having a different dissolution rate, were used to replace the dissolved chalk. The three dissolution rates resulted in three different steady state pH levels in the reactor (4.7-6.6) and nitrification rates. Nitrification was found to be limited by either the chalk dissolution rate or dissolved oxygen concentration depending on the type of chalk used. A maximal nitrification rate of 1.44 g NH4(+)-N/l reactor.d was observed. The average cell yield was 0.1 g cells/g N oxidized, similar to the cell yield during reactor start-up when the pH was 7. The specific ammonium oxidation rates varied between 0.08 and 0.15 mg NH4(+)-N oxidized/mg protein.h, values which are in the reported range for nitrification at pH 7 to 8. Oxygen update rate (OUR) results indicated that the major mechanism responsible for the high nitrification rate observed in the reactor operating at low pH seems to be the favorable microenvironment provided by the chalk.

  17. Transport of Optically Active Particles From the Surface Mixed Layer: Losses Due to Grazing and Focculation During the Chalk-Ex Study

    DTIC Science & Technology

    2008-09-30

    chalk particle flocculation : We will measure the flocculation rates of the chalk particles in Couette devices (Drapeau et al., 1994, Dam and Drapeau...1995) from knowledge of the chalk flocculation efficiency, the chalk particle diameter and the shear rate. The ambient shear rates will be obtained...GALAI). Both of these devices can resolve particles as small as 0.5 µm. There is a possibility that the flocculation efficiency of the chalk

  18. Assessment of groundwater usage at Chalk Point power plant. Final report

    SciTech Connect

    Not Available

    1982-07-01

    In order to quantify the usage of ground water in an operating electric power plant, a study was initiated in 1978 aimed at determining where in the energy conversion process ground water is used and to suggest, if possible, alternate means for providing this water and/or methods to reduce consumption. The Chalk Point Plant was selected for this study because of its difference in fuel source (coal and oil), and because of its high consumption of ground water (approximately 800,000 to 1,200,000 gallons per day). Located at the confluence of the Patuxent River and Swanson Creek in the southeast corner of Prince George's County, Maryland, it consists of three operating units, with a fourth unit under construction during the survey time. (unit 4 has recently become operational). With the cooperation of the Potomac Electric Power Company, the plant was selected for study and was instrumented with several flow meters. Over a two-year period, this plant has been monitored to provide the information needed to make an assessment of the rates, nature, and methods of water usage in an operating power plant.

  19. The influence of water and supercritical CO2 on the failure behavior of chalk

    NASA Astrophysics Data System (ADS)

    Liteanu, E.; Spiers, C. J.; de Bresser, J. H. P.

    2013-06-01

    Reduction of compressive strength by injection of water into chalk is a well-known mechanism responsible for increased compaction in chalk reservoirs. This raises the question of whether such effects might be enhanced in the context of long-term storage of CO2 or of CO2 injection for enhanced oil and gas recovery (EOR/EGR) purposes. Therefore, data regarding the effect of supercritical CO2 on the mechanical behavior of chalk are needed. The effect of supercritical CO2 on the short-term failure behavior of wet chalk was accordingly investigated by means of conventional triaxial deformation experiments, performed on Maastrichtian chalk cores under dry conditions, in the presence of saturated chalk solution and using CO2-saturated solution at temperatures simulating reservoir conditions (20-80 °C) and effective confining pressures up to 7 MPa. Increasing temperature from 20 to 80 °C did not show any significant effects on the strength of the dry samples. Addition of aqueous solution to the samples led to drastic weakening of the chalk, the effect being more pronounced at high effective confining pressures (Peff > 3 MPa). Addition of 10 MPa supercritical CO2 to wet samples did not produce any significant additional effect in comparison with the wet samples. All samples showed a yield strength envelope characterized by shear failure at low effective mean stresses giving way to a compaction cap at high mean stresses. The weakening effect of aqueous solution was explained in terms of a reduction in frictional resistance of the material, due to water-enhanced grain-contact cracking, and perhaps pressure solution, with a possible contribution by disjoining pressure effects caused by water adsorption. While CO2 does not seem to reduce short-term failure strength of wet chalk, processes such as intergranular pressure solution have to be considered for assessing mechanical stability of chalk in the context of long-term CO2 storage or EOR/EGR operations.

  20. Seismic architecture of the Chalk Group from onshore reflection data in eastern Denmark

    NASA Astrophysics Data System (ADS)

    Moreau, Julien; Anderskouv, Kresten; Boldreel, Lars Ole; Boussaha, Myriam; Nielsen, Lars; Stemmerik, Lars; Surlyk, Finn; Thibault, Nicolas

    2013-04-01

    The Upper Cretaceous-Danian chalk is well exposed in the 14 km long coastal cliff of Stevns Klint (eastern Denmark). The cliff is a world renowned for its spectacular exposure of the Cretaceous-Palaeogene boundary. Based on regional geological knowledge of the field and cores, the characteristics of the Chalk Group have been well constrained. Distinct sedimentary facies have been encountered; the sedimentology, the biostratigraphy, the diagenesis and the reservoir properties have been thoroughly investigated and reported. Stimulated by the intensive geological research, the field studies have been completed with the acquisition of an extensive set of subsurface data. The data include high resolution 2D multichannel seismics onshore and offshore, a seismic refraction profile, two entirely cored boreholes including wireline logs, GPR cross-hole tomography, thermographic analysis, etc. We intend to compile and merge the geological and geophysical datasets to investigate the variation of the Chalk Group properties and their signature in the subsurface. In this communication, the seismic reflection data are being analysed. Very high resolution litho-, bio- and cyclostratigraphy can be correlated with the seismic stratigraphy. Several seismic facies are identified in the Chalk Group: the 'transparent' (white chalk), the stratified (marl-chalk alternations), the crudely stratified (flint-rich chalk) and the hummocky (bryozoan mounds). The units notably vary in thickness at a relatively small scale. The variations confirm the complex shelf organisation which was highly influenced by bottom currents. In addition to the stratigraphic observations, peculiar deformation structures can be recognised. The area has been supposedly tectonically stable since deposition as the coastal cliff lacks fault offset but the succession has been uplifted of c. 1 km. The main fracture patterns are associated with the recent unloading of the ice, opening shallow horizontal fractures

  1. Diffusive parameters of tritiated water and uranium in chalk

    SciTech Connect

    Descostes, M.; Pili, E.; Felix, O.; Frasca, B.; Radwan, J.; Juery, A.

    2012-07-15

    The Cretaceous Chalk of North-western Europe exhibits a double porosity (matrix and fracture) providing pathways for both slow and rapid flow of water. The present study aims at understanding and predicting the contaminant transfer properties through a significant section of this formation, with a particular emphasis on diffusion. This requires to study the nature of porosity and to perform diffusion experiments in representative samples using uranium and tritiated water (HTO), respectively taken as a reactive tracer and an inert one. The diffusive parameters, i.e. the accessible porosity and the effective diffusion coefficient were determined. Additional information was obtained with mercury porosimetry, gravimetric water content, textural and mineralogical characterization. The diffusion tests performed with HTO appear to be the best method to measure the total accessible porosity in any type of porous media, especially those having large pore size distributions. Our study demonstrates that classical gravimetric water content measurements are not sensitive to the reduction in pore size as opposed to HTO diffusion tests because capillary water is not extracted by conventional gravimetric method but can still be probed by diffusion experiments. We found effective diffusion coefficients D{sub e}(U(VI)) near 4 x 10{sup -10} m{sup 2}s{sup -1}). The slower migration of U(VI) compared to HTO indicates sorption, with R{sub d}(U(VI)) from 100 to 360 mL g{sup -1}. These values are one order of magnitude larger than other determinations of the U(VI) sorption coefficient because only the matrix porosity is concerned here. The migration of U(VI) in chalk is only limited by sorption on ancillary Fe-Pb-bearing minerals. Transport of HTO and U(VI) is independent of the porosity distribution. Uranium diffusion in the chalk matrix porosity is fast enough to allow the total invasion of the pore space within characteristic time scales of the order of 1000 years. This results in a

  2. Rivers

    USGS Publications Warehouse

    Leopold, Luna Bergere

    1962-01-01

    Rivers are both the means and the routes by which the products of continental weathering are carried to the oceans of the world. Except in the most arid areas more water falls as precipitation than is lost by evaporation and transpiration from the land surface to the atmosphere. Thus there is an excess of water, which must flow to the ocean. Rivers, then, are the routes by which this excess water flows to the ultimate base level. The excess of precipitation over evaporation and transpiration provides the flow of rivers and springs, recharges ground-water storage, and is the supply from which man draws water for his needs.

  3. Nitrogen speciation and phosphorus fractionation dynamics in a lowland Chalk catchment.

    PubMed

    Yates, C A; Johnes, P J

    2013-02-01

    A detailed analysis of temporal and spatial trends in nitrogen (N) speciation and phosphorus (P) fractionation in the Wylye, a lowland Chalk sub-catchment of the Hampshire Avon, UK is presented, identifying the sources contributing to nutrient enrichment, and temporal variability in the fractionation of nutrients in transit from headwaters to lower reaches of the river. Samples were collected weekly from ten monitoring stations with daily sampling at three further sites over one year, and monthly inorganic N and total reactive P (TRP) concentrations at three of the ten weekly monitoring stations over a ten year period are also presented. The data indicate significant daily and seasonal variation in nutrient fractionation in the water column, resulting from plant uptake of dissolved organic and inorganic nutrient fractions in the summer months, increased delivery of both N and P from diffuse sources in the autumn to winter period and during high flow events, and lack of dilution of point source discharges to the Wylye from septic tank, small package Sewage Treatment Works (STW) and urban Waste Water Treatment Works (WwTW) during the summer low flow period. Weekly data show that contributing source areas vary along the river with headwater N and P strongly influenced by diffuse inorganic N and particulate P fluxes, and SRP and organic-rich point source contributions from STW and WwTW having a greater influence in the lower reaches. Long-term data show a decrease in TRP concentrations at all three monitoring stations, with the most pronounced decrease occurring downstream from Warminster WwTW, following the introduction of P stripping at the works in 2001. Inorganic N demonstrates no statistically significant change over the ten year period of record in the rural headwaters, but an increase in the lower reaches downstream from the WwTW which may be due to urban expansion in the lower catchment.

  4. A parameter identifiability study of two chalk tracer tests

    NASA Astrophysics Data System (ADS)

    Mathias, S. A.; Butler, A. P.; Atkinson, T. C.; Kachi, S.; Ward, R. S.

    2006-08-01

    As with most fractured rock formations, Chalk is highly heterogeneous. Therefore, meaningful estimates of model parameters must be obtained at a scale comparable with the process of concern. These are frequently obtained by calibrating an appropriate model to observed concentration-time data from radially convergent tracer tests (RCTT). Arguably, an appropriate model should consider radially convergent dispersion (RCD) and Fickian matrix diffusion. Such a model requires the estimation of at least four parameters. A question arises as to whether or not this level of model complexity is supported by the information contained within the calibration data. Generally modellers have not answered this question due to the calibration techniques employed. A dual-porosity model with RCD was calibrated to two tracer test datasets from different UK Chalk aquifers. A multivariate sensitivity analysis, which assumed only a priori upper and lower bounds for each model parameter, was undertaken. Rather than looking at measures of uncertainty, the shape of the multivariate objective function surface was used to determine whether a parameter was identifiable. Non-identifiable parameters were then removed and the procedure was repeated until all remaining parameters were identifiable. It was found that the single fracture model (SFM) (which ignores mechanical dispersion) obtained the best mass recovery, excellent model performance and best parameter identifiability in both the tests studied. However, there was no objective evidence suggesting that mechanical dispersion was negligible. Moreover, the SFM (with just two parameters) was found to be good at approximating the Single Fracture Dispersion Model SFDM (with three parameters) when different, and potentially erroneous parameters, were used. Overall, this study emphasises the importance of adequate temporal sampling of breakthrough curve data prior to peak concentrations, to ensure adequate characterisation of mechanical dispersion

  5. Imaging the Danish Chalk Group with high resolution, 3-component seismics

    NASA Astrophysics Data System (ADS)

    Kammann, J.; Rasmussen, S. L.; Nielsen, L.; Malehmir, A.; Stemmerik, L.

    2016-12-01

    The Chalk Group in the Danish Basin forms important reservoirs to hydrocarbons as well as water resources, and it has been subject to several seismic studies to determine e.g. structural elements, deposition and burial history. This study focuses on the high quality seismic response of a survey acquired with an accelerated 45 kg weight drop and 3-component MEMS-based sensors and additional wireless vertical-type sensors. The 500 m long profile was acquired during one day close to a chalk quarry and chalk cliffs of the Stevns peninsula in eastern Denmark where the well-known K-T (Cretaceous-Tertiary) boundary and different chalk lithologies are well-exposed. With this simple and fast procedure we were able to achieve deep P-wave penetration to the base of the Chalk Group at about 900 m depth. Additionally, the CMP-processed seismic image of the vertical component stands out by its high resolution. Sedimentary features are imaged in the near-surface Danian, as well as in the deeper Maastrichtian and Upper Campanian parts of the Chalk Group. Integration with borehole data suggests that changes in composition, in particular clay content, correlate with changes in reflectivity of the seismic data set. While the pure chalk in the Maastrichtian deposits shows rather low reflectivity, succession enriched in clay appear to be more reflective. The integration of the mentioned methods gives the opportunity to connect changes in facies to the elastic response of the Chalk Group in its natural environmental conditions.

  6. Towards a simple representation of chalk hydrology in land surface modelling

    NASA Astrophysics Data System (ADS)

    Rahman, Mostaquimur; Rosolem, Rafael

    2017-01-01

    Modelling and monitoring of hydrological processes in the unsaturated zone of chalk, a porous medium with fractures, is important to optimize water resource assessment and management practices in the United Kingdom (UK). However, incorporating the processes governing water movement through a chalk unsaturated zone in a numerical model is complicated mainly due to the fractured nature of chalk that creates high-velocity preferential flow paths in the subsurface. In general, flow through a chalk unsaturated zone is simulated using the dual-porosity concept, which often involves calibration of a relatively large number of model parameters, potentially undermining applications to large regions. In this study, a simplified parameterization, namely the Bulk Conductivity (BC) model, is proposed for simulating hydrology in a chalk unsaturated zone. This new parameterization introduces only two additional parameters (namely the macroporosity factor and the soil wetness threshold parameter for fracture flow activation) and uses the saturated hydraulic conductivity from the chalk matrix. The BC model is implemented in the Joint UK Land Environment Simulator (JULES) and applied to a study area encompassing the Kennet catchment in the southern UK. This parameterization is further calibrated at the point scale using soil moisture profile observations. The performance of the calibrated BC model in JULES is assessed and compared against the performance of both the default JULES parameterization and the uncalibrated version of the BC model implemented in JULES. Finally, the model performance at the catchment scale is evaluated against independent data sets (e.g. runoff and latent heat flux). The results demonstrate that the inclusion of the BC model in JULES improves simulated land surface mass and energy fluxes over the chalk-dominated Kennet catchment. Therefore, the simple approach described in this study may be used to incorporate the flow processes through a chalk unsaturated

  7. Chalk-Ex: Transport of Optically Active Particles from the Surface Mixed Layer

    DTIC Science & Technology

    2005-05-02

    dissolution , aggregation, and grazing- related "repackaging" into fecal pellets). Approach The focus of the Chalk-Ex project was a sequence of...experiment in which the production term of optically-active particles could be defined, significantly reducing the uncertainty of the net loss rates of...suspended calcite algorithm. The NASA project paid for the 26 T of chalk and some of the ship time for the November 2001 experiments. A DURIP Grant to J

  8. Use of Modeling for Prevention of Solids Formation During Canyon Processing of Legacy Nuclear Materials at the Savannah River Site

    SciTech Connect

    Rhodes, W. D.; Crooks III, W. J.; Christian, J. D.

    2002-02-26

    The Savannah River Site (SRS) Environmental Management (EM) nuclear material stabilization program includes the dissolution and processing of legacy materials from various DOE sites. The SRS canyon facilities were designed to dissolve and process spent nuclear fuel and targets. As the processing of typical materials is completed, unusual and exotic nuclear materials are being targeted for stabilization. These unusual materials are often difficult to dissolve using historical flowsheet conditions and require more aggressive dissolver solutions. Solids must be prevented in the dissolver to avoid expensive delays associated with the build-up of insoluble material in downstream process equipment. Moreover, it is vital to prevent precipitation of all solids, especially plutonium-bearing solids, since their presence in dissolver solutions raises criticality safety issues. To prevent precipitation of undesirable solids in aqueous process solutions, the accuracy of computer models to predict precipitate formation requires incorporation of plant specific fundamental data. These data are incorporated into a previously developed thermodynamic computer program that applies the Pitzer correlation to derive activity coefficient parameters. This improved predictive model will reduce unwanted precipitation in process solutions at DOE sites working with EM nuclear materials in aqueous solutions.

  9. TRANSFER OF EXCESS NUCLEAR MATERIAL FROM LOS ALAMOS TO SAVANNAH RIVER SITE FOR LONG-TERM DISPOSITION

    SciTech Connect

    C. W. HOTH; L. A. FOSTER; T. F YARBRO

    2001-06-01

    Los Alamos National Laboratory is preparing excess nuclear material for shipment to Savannah River Site (SRS) for final disposition. Prior to shipment the nuclear material will be stabilized and packaged to meet strict criteria. The criterion that must be met include: (1) the DOE stabilization, packaging and storage requirements for plutonium bearing materials, DOE-STD-3013, (2) shipping container packaging requirements, (3) SRS packaging and storage criteria, and (4) DOE Material Disposition criteria for either immobilization or MOX reactor fuel. Another issue in preparing for this transfer is the DOE certification of shipping containers and the availability of shipping containers. This transfer of the nuclear material is fully supported by the EM, DP and NN Sections of the DOE, as well as, by LANL and SRS, yet a strong collaboration is needed to meet all established requirements relating to stabilization, packaging, shipment, storage and final disposition. This paper will present the overall objectives, the issues and the planned strategy to accomplish this nuclear material transfer.

  10. Decisions Shape a Lab (Lab Notes).

    ERIC Educational Resources Information Center

    Porter, Bernajean

    1992-01-01

    Offers questions to guide both initial and ongoing development of a computer writing lab. Discusses ways mobile workstations (consisting of a computer, printer, overhead, and a LCD projection unit) will extend the writing lab. (SR)

  11. Underwater lab

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The University of Southern California's Catalina Marine Science Center (CMSC) has announced plans to build an underwater marine research laboratory near Santa Catalina Island off the California coast. The project, which will take 2 years to build, will be sponsored by the National Oceanic and Atmospheric Administration (NOAA). The laboratory will be similar in concept to the U.S. Navy Sea Lab III, which was canceled some time ago.The project's purpose is to give divers access to a laboratory without having to surface. The project leader, Andrew Pilmanis, of the University of Southern California, stated recently (Industrial Research and Development, July 1983): “By the nature of the work, scientists require a lot of bottom time, and to do it by scuba isn't practical…. The only way to do that is with saturation diving. Once the diver is saturated with inert gas, whether the individual stays a few days or for months, only one decompression is required.” Divers will typically stay in the laboratory for 7-10 days. The laboratory will initially be placed at a depth of 20 m, later to be refloated and located at depths to 37 m.

  12. Mineralization of aged atrazine and mecoprop in soil and aquifer chalk.

    PubMed

    Kristensen, G B; Johannesen, H; Aamand, J

    2001-11-01

    The effect of ageing on the bioavailability and sorption of the herbicides atrazine and mecoprop was studied in soil and aquifer chalk sampled at an agricultural field near Aalborg, Denmark. The herbicides were incubated in sterile soil or chalk up to 3 months prior to inoculation with 5 x 10(7) cells g(-1) (dry weight) of a mecoprop degrading highly enriched culture (PM) or 1 x 10(9) cells g(-1) (dry weight) of the atrazine degrading Pseudomonas sp. strain ADP. As a measure of the bioavailable residues accumulated 14CO2 was measured for 2 months. In both soil and chalk ageing limited the rate of atrazine mineralization, and in chalk the extent of mineralization was reduced as well. The fraction of sorbed atrazine in the soil ranged between 50% and 62%, whereas a maximum of 12% was sorbed in chalk. No impact on the mineralization of aged mecoprop was seen as no sorption of this herbicide on either soil or chalk was measured.

  13. 3D characterization of the fracture network in a deformed chalk reservoir analogue: The Lagerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1994-12-31

    Quantitative descriptions of the 3D fracture networks in terms of connectivity, fracture types, fracture surface roughness and flow characteristics are necessary for reservoir evaluation, management, and enhanced oil recovery programs of fractured reservoirs. For a period of 2 years, a research project focused on an analogue to fractured chalk reservoirs excellently exposed near Laegerdorf, NW Germany. Upper Cretaceous chalk has been uplifted and deformed by an underlying salt diapir, and is now exploited for the cement industry. In the production wall of a quarry, the fracture network of the deformed chalk was characterized and mapped at different scales. The wall was scraped off as chalk exploitation proceeded, continuously revealing new sections through the faulted and fractured chalk body. A 230 m long part of the 35m high production wall was investigated during its recess of 25m. The large amount of fracture data were analyzed with respect to parameters such as fracture density distribution, orientation- and length distribution, and in terms of the representativity of data sets collected from restricted rock volumes. This 3D description and analysis of a fracture network revealed quantitative generic parameters of importance for modeling chalk reservoirs with less data and lower data quality.

  14. Reactive transport modelling of groundwater chemistry in a chalk aquifer at the watershed scale.

    PubMed

    Mangeret, A; De Windt, L; Crançon, P

    2012-09-01

    This study investigates thermodynamics and kinetics of water-rock interactions in a carbonate aquifer at the watershed scale. A reactive transport model is applied to the unconfined chalk aquifer of the Champagne Mounts (France), by considering both the chalk matrix and the interconnected fracture network. Major element concentrations and main chemical parameters calculated in groundwater and their evolution along flow lines are in fair agreement with field data. A relative homogeneity of the aquifer baseline chemistry is rapidly reached in terms of pH, alkalinity and Ca concentration since calcite equilibrium is achieved over the first metres of the vadose zone. However, incongruent chalk dissolution slowly releases Ba, Mg and Sr in groundwater. Introducing dilution effect by rainwater infiltration and a local occurrence of dolomite improves the agreement between modelling and field data. The dissolution of illite and opal-CT, controlling K and SiO(2) concentrations in the model, can be approximately tackled by classical kinetic rate laws, but not the incongruent chalk dissolution. An apparent kinetic rate has therefore been fitted on field data by inverse modelling: 1.5×10(-5) mol(chalk)L (-1) water year (-1). Sensitivity analysis indicates that the CO(2) partial pressure of the unsaturated zone is a critical parameter for modelling the baseline chemistry over the whole chalk aquifer.

  15. The effect of chalk on the finger-hold friction coefficient in rock climbing.

    PubMed

    Amca, Arif Mithat; Vigouroux, Laurent; Aritan, Serdar; Berton, Eric

    2012-11-01

    The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were performed. Participants hung from holds which were fixed on a specially designed hang board. The inclination of the hang board was progressively increased until the climber's hand slipped from the holds. The angle of the hang board was simultaneously recorded by using a gyroscopic sensor and the friction coefficient was calculated at the moment of slip. The results showed that there was a significant positive effect of chalk on the coefficient of friction (+18.7% on limestone and +21.6% on sandstone). Moreover sandstone had a higher coefficient of friction than limestone (+15.6% without chalk, +18.4% with chalk). These results confirmed climbers' belief that chalk enhances friction. However, no correlation with humidity/temperature and friction coefficient was noted which suggested that additional parameters should be considered in order to understand the effects of climate on finger friction in rock climbing.

  16. Future projection of radiocesium flux to the ocean from the largest river impacted by Fukushima Daiichi Nuclear Power Plant.

    PubMed

    Adhiraga Pratama, Mochamad; Yoneda, Minoru; Shimada, Yoko; Matsui, Yasuto; Yamashiki, Yosuke

    2015-02-12

    Following the initial fall out from Fukushima Dai-ichi Nuclear Power Plant (FDNPP), a significant amount of radiocesium has been discharged from Abukuma River into the Pacific Ocean. This study attempted to numerically simulate the flux of radiocesium into Abukuma River by developing the multiple compartment model which incorporate the transport process of the radionuclide from the ground surface of the catchment area into the river, a process called wash off. The results from the model show that the sub-basins with a high percentage of forest area release the radionuclides at lower rate compared to the other sub-basins. In addition the results show that the model could predict the seasonal pattern of the observed data. Despite the overestimation observed between the modeled data and the observed data, the values of R(2) obtained from (137)Cs and (134)Cs of 0.98 and 0.97 respectively demonstrate the accuracy of the model. Prediction of the discharge from the basin area for 100 years after the accident shows that, the flux of radiocesium into the Pacific Ocean is still relatively high with an order of magnitude of 10(9) bq.month(-1) while the total accumulation of the discharge is 111 TBq for (137)Cs and 44 TBq for (134)Cs.

  17. Future projection of radiocesium flux to the ocean from the largest river impacted by Fukushima Daiichi Nuclear Power Plant

    PubMed Central

    Adhiraga Pratama, Mochamad; Yoneda, Minoru; Shimada, Yoko; Matsui, Yasuto; Yamashiki, Yosuke

    2015-01-01

    Following the initial fall out from Fukushima Dai-ichi Nuclear Power Plant (FDNPP), a significant amount of radiocesium has been discharged from Abukuma River into the Pacific Ocean. This study attempted to numerically simulate the flux of radiocesium into Abukuma River by developing the multiple compartment model which incorporate the transport process of the radionuclide from the ground surface of the catchment area into the river, a process called wash off. The results from the model show that the sub-basins with a high percentage of forest area release the radionuclides at lower rate compared to the other sub-basins. In addition the results show that the model could predict the seasonal pattern of the observed data. Despite the overestimation observed between the modeled data and the observed data, the values of R2 obtained from 137Cs and 134Cs of 0.98 and 0.97 respectively demonstrate the accuracy of the model. Prediction of the discharge from the basin area for 100 years after the accident shows that, the flux of radiocesium into the Pacific Ocean is still relatively high with an order of magnitude of 109 bq.month−1 while the total accumulation of the discharge is 111 TBq for 137Cs and 44 TBq for 134Cs. PMID:25673214

  18. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    SciTech Connect

    Maruthi, Y. A.; Das, N. Lakshmana; Ramprasad, S.; Ram, S. S.; Sudarshan, M.

    2015-08-28

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk.

  19. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    NASA Astrophysics Data System (ADS)

    Maruthi, Y. A.; Das, N. Lakshmana; Ramprasad, S.; Ram, S. S.; Sudarshan, M.

    2015-08-01

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk

  20. Advanced Physics Lab at TCU

    NASA Astrophysics Data System (ADS)

    Quarles, C. A.

    2009-04-01

    The one semester, one credit hour Modern Physics Lab is viewed as a transition between the structured Physics 1 and 2 labs and junior/senior research. The labs focus on a variety of experiments built around a multichannel analyzer, various alpha, beta and gamma ray detectors and weak radioactive sources. Experiments include radiation safety and detection with a Geiger counter and NaI detector, gamma ray spectroscopy with a germanium detector, beta spectrum, alpha energy loss, gamma ray absorption, Compton effect, nuclear and positron annihilation lifetime, speed of gamma rays. Other experiments include using the analog oscilloscope, x-ray diffraction of diamond and using an SEM/EDX. Error analysis is emphasized throughout. The semester ends with an individual project, often an extension of one of the earlier experiments, and students present their results as a paper and an APS style presentation to the department.

  1. Preliminary estimate of possible flood elevations in the Columbia River at Trojan Nuclear Power Plant due to failure of debris dam blocking Spirit Lake, Washington

    USGS Publications Warehouse

    Kresch, D.L.; Laenen, Antonius

    1984-01-01

    Failure of the debris dam, blocking the outflow of Spirit Lake near Mount St. Helens, could result in a mudflow down the Toutle and Cowlitz Rivers into the Columbia River. Flood elevations at the Trojan Nuclear Power Plant on the Columbia River, 5 mi upstream from the Cowlitz River, were simulated with a hydraulic routing model. The simulations are made for four Columbia River discharges in each of two scenarios, one in which Columbia River floods coincide with a mudflow and the other in which Columbia River floods follow a mudflow sediment deposit upstream from the Cowlitz River. In the first scenario, Manning 's roughness coefficients for clear water and for mudflow in the Columbia River are used; in the second scenario only clear water coefficients are used. The grade elevation at the power plant is 45 ft above sea level. The simulated elevations exceed 44 ft if the mudflow coincides with a Columbia River discharge that has a recurrence interval greater than 10 years (610,000 cu ft/sec); the mudflow is assumed to extend downstream from the Cowlitz River to the mouth of the Columbia River, and Manning 's roughness coefficients for a mudflow are used. The simulated elevation is 32 ft if the mudflow coincides with a 100-yr flood (820,000 cu ft/sec) and clear-water Manning 's coefficients are used throughout the entire reach of the Columbia River. The elevations exceed 45 ft if a flow exceeding the 2-yr peak discharge in the Columbia River (410,000 cu ft/sec) follows the deposit of 0.5 billion cu yd of mudflow sediment upstream of the Cowlitz River before there has been any appreciable scour or dredging of the deposit. In this simulation it is assumed that: (1) the top of the sediment deposited in the Columbia River is at an elevation of 30 ft at the mouth of the Cowlitz River, (2) the surface elevation of the sediment deposit decreases in an upstream direction at a rate of 2.5 ft/mi, and (3) clear water Manning 's coefficients apply to the entire modeled reach of

  2. Characteristics of pore structures in Selma Chalk using dual FIB-SEM 3D imaging and Lattice Boltzmann Modeling

    NASA Astrophysics Data System (ADS)

    Yoon, H.; Dewers, T. A.

    2012-12-01

    Accurate prediction of coupled geophysical and chemical processes at the pore scale requires realistic representation of pore structures. This is especially true for chalk materials, where pore networks are small and complex, and often characterized at sub-micron scale. Common techniques such as X-ray microtomography, microscopic imaging, or mercury intrusion porosimetry often show a limit on determining pore throat distributions and seal analysis of such fine-grained rocks. Focused ion beam-scanning electron microscope (FIB-SEM) and laser scanning confocal microscopy methods are used for 3D imaging of nanometer-to-micron scale microcrack and pore distributions in samples of the Cretaceous Selma Group Chalk. The Selma Chalk is considered the seal for oil and gas fields in the Mississippi Interior Salt Basin and a proposed regional-scale seal identified for CO2 sequestration sites. A series of image analysis techniques is used to process raw images in order to recover both nano-scale pore structure and continuous fracture networks. We apply 3D imaging techniques in interpreting FIB-SEM binary data for characterizing geometric pore body and throat distributions and other topological properties, and lattice-Boltzmann method (LBM) for obtaining permeability at several different scales. In particular, comparison of primary flow paths obtained from 3D image analysis and LBM demonstrates that image analysis results may have too many equally plausible flow paths, compared to LBM results. Upscaling of permeability and LB multiphase flow results with image dataset will be discussed with emphasis on understanding microfracture-matrix interaction during multiphase flow, and seal analysis for geologic CO2 storage. 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

  3. Current oil and gas production from North American Upper Cretaceous chalks

    USGS Publications Warehouse

    Scholle, Peter A.

    1977-01-01

    Production of oil and natural gas from North American chalks has increased significantly during the past five years, spurred by the prolific production from North Sea chalks, as well as by higher prices and improved production technology. Chalk reservoirs have been discovered in the Gulf Coast in the Austin Group, Saratoga and Annona Chalks, Ozan Formation, Selma Group, Monroe gas rock (an informal unit of Navarro age), and other Upper Cretaceous units. In the Western Interior, production has been obtained from the Cretaceous Niobrara and Greenhorn Formations. Significant, though subcommercial, discoveries of natural gas and gas condensate also have been made in the Upper Cretaceous Wyandot Formation on the Scotian Shelf of eastern Canada. All North American chalk units share a similar depositional and diagenetic history. The chalks consist primarily of whole and fragmented coccoliths with subordinate planktonic and benthonic Foraminifera, inoceramid prisms, oysters, and other skeletal grains. Most have between 10 and 35 percent HCl-insoluble residue, predominantly clay. Deposition was principally below wave base in tens to hundreds of meters of water. The diagenetic history of a chalk is critical in determining its reservoir potential. All chalk has a stable composition (low-Mg calcite) and very high primary porosity. With subsequent burial, mechanical and chemical (solution-transfer) compaction can reduce or completely eliminate pore space. The degree of loss of primary porosity in chalk sections is normally a direct function of the maximum depth to which it has been buried. Pore-water chemistry, pore-fluid pressures, and tectonic stresses also influence rates of cementation. Oil or gas reservoirs of North American chalk fall into three main groups: 1. Areas with thin overburden and significant primary porosity retention (for example, Niobrara Formation of Kansas and eastern Colorado). 2. Areas with thicker overburden but considerable fracturing. Here primary

  4. Characterization of the hydraulic properties of fractures in chalk.

    PubMed

    Nativ, Ronit; Adar, Eilon; Assaf, Lior; Nygaard, Erik

    2003-01-01

    The fracture systems intersecting Eocene chalk formations in the Negev desert, Israel, and their hydraulic properties were characterized using a variety of geologic and hydrologic techniques. These included identification of the prevailing directions of fracture systems in outcrops, in cores retrieved from inclined coreholes, in coreholes using video logs, and in trenches. The orientation and inclination of these fracture systems were determined, and evidence of ground water flow on the fracture surfaces was described and ranked. Their hydraulic conductivity was determined through slug and pumping tests performed at discrete intervals. Temperature, electrical conductivity, caliper, gamma and heat-pulse logs were conducted in the same coreholes. The results from the logs, tests, and core descriptions were compared to identify reliable and cost-effective tools for investigating the hydraulic characteristics of fracture systems. We concluded that in the study area: (1) fracture mapping in outcrops and coreholes (including downhole video and caliper logs) must be supplemented by hydraulic testing of the mapped fracture sets in the coreholes; (2) inclined coreholes provide information regarding the orientation of the hydraulically active fracture systems that cannot be obtained from vertical boreholes; (3) hydraulic testing of unpacked holes provides a reasonable estimate of the maximum hydraulic conductivity; and (4) the hydraulic conductivity distribution with depth is log normal and all significant ground water flow takes place within the upper 25 m.

  5. Effects of the restoration mortar on chalk stone buildings

    NASA Astrophysics Data System (ADS)

    Ion, R. M.; Teodorescu, S.; Ştirbescu, R. M.; Dulamă, I. D.; Şuică-Bunghez, I. R.; Bucurică, I. A.; Fierăscu, R. C.; Fierscu, I.; Ion, M. L.

    2016-06-01

    The monument buildings as components of cultural heritage are exposed to degradation of surfaces and chemical and mechanical degradation, often associated to soiling and irreversible deterioration of the building. In many conservative and restorative works, a cement-based mortar was used without knowing all the adverse effects of this material on the building. This paper deals with the study of the effects of natural cement used in restorative works in the particular case of the Basarabi-Murfatlar Churches Ensemble. Cement-based materials exposed to sulfate present in the chalk stone - gypsum (CaSO4.2H2O), can induce signs of deterioration, due to ettringite ([Ca3Al (OH)612H2O]2(SO4)32H2O) or thaumasite (Ca3[Si(OH)612H2O](CO3)SO4) formation. These phases contribute to strain within the material, inducing expansion, strength loss, spalling and severe degradation. Several combined techniques (XRD, EDXRF, ICP-AES, SEM, EDS, sulphates content, FT-IR and Raman analysis were carried out to put into evidence the effects of them on the building walls.

  6. Stability analysis of chalk sea cliffs using UAV photogrammetry

    NASA Astrophysics Data System (ADS)

    Barlow, John; Gilham, Jamie

    2017-04-01

    Cliff erosion and instability poses a significant hazard to communities and infrastructure located is coastal areas. We use point cloud and spectral data derived from close range digital photogrammetry to assess the stability of chalk sea cliffs located at Telscombe, UK. Data captured from an unmanned aerial vehicle (UAV) were used to generate dense point clouds for a 712 m section of cliff face which ranges from 20 to 49 m in height. Generated models fitted our ground control network within a standard error of 0.03 m. Structural features such as joints, bedding planes, and faults were manually mapped and are consistent with results from other studies that have been conducted using direct measurement in the field. Kinematic analysis of these data was used to identify the primary modes of failure at the site. Our results indicate that wedge failure is by far the most likely mode of slope instability. An analysis of sequential surveys taken from the summer of 2016 to the winter of 2017 indicate several large failures have occurred at the site. We establish the volume of failure through change detection between sequential data sets and use back analysis to determine the strength of shear surfaces for each failure. Our results show that data capture through UAV photogrammetry can provide useful information for slope stability analysis over long sections of cliff. The use of this technology offers significant benefits in equipment costs and field time over existing methods.

  7. Microbial secondary succession in a chronosequence of chalk grasslands.

    PubMed

    Kuramae, Eiko E; Gamper, Hannes A; Yergeau, Etienne; Piceno, Yvette M; Brodie, Eoin L; Desantis, Todd Z; Andersen, Gary L; van Veen, Johannes A; Kowalchuk, George A

    2010-05-01

    Although secondary succession has been studied extensively, we have little knowledge of the succession of soil-borne microbial communities. In this study, we therefore examined the structures of the microbial communities across two separate chronosequences of chalk grasslands in Limburg, the Netherlands, which are at different stages of secondary succession after being abandoned for between 17 and >66 years. Arable fields were also included in the investigation as non-abandoned references. Changes in the soil-borne microbial communities, as determined by phylogenetic microarray and quantitative PCR methodologies, were correlated with the prevailing environmental conditions related to vegetation and soil biochemistry. We observed clear patterns of microbial secondary succession related to soil age, pH and phosphate status, as exemplified by the overrepresentation of Verrucomicrobia, Acidobacteria, Gemmatimonadetes, and alpha-, delta- and epsilon-Proteobacteria at late successional stages. Moreover, effects of secondary succession versus changes in soil pH could be resolved, with pH significantly altering the trajectory of microbial succession.

  8. Absolute paleobathymetry of Upper Cretaceous chalks based on ostracodes - Evidence from the Demopolis Chalk (Campanian and Maastrichtian) of the northern Gulf Coastal Plain

    SciTech Connect

    Puckett, T.M. )

    1991-05-01

    The presence of abundant and diverse sighted ostracodes in chalk and marl of the Demopolis Chalk (Campanian and Maastrichtian) in Alabama and Mississippi strongly suggests that the Late Cretaceous sea floor was within the photic zone. The maximum depth of deposition is calculated from an equation based on eye morphology and efficiency and estimates of the vertical light attenuation. In this equation, K, the vertical light attenuation coefficient, is the most critical variable because it is the divisor for the rest of the equation. Rates of accumulation of coccoliths during the Cretaceous are estimated and are on the same order as those in modern areas of high phytoplankton production, suggesting similar pigment and coccolith concentrations in the water column. Values of K are known for a wide range of water masses and pigment concentrations, including areas of high phytoplankton production; thus light attenuation through the Cretaceous seas can be estimated reliably. Waters in which attenuation is due only to biogenic matter-conditions that result in deposition of relatively pure chalk-have values of K ranging between 0.2 and 0.3. Waters rich in phytoplankton and mud-conditions that result in deposition of marl-have K values as great as 0.5. Substituting these values for K results in depth range of 65 to 90 m for deposition of chalk and depth of 35 m for deposition of marl. These depth values suggest that deposition of many Cretaceous chalks and marls around the world were deposited under relatively shallow conditions.

  9. Distribution of dissolved and particulate radiocesium concentrations along rivers and the relations between radiocesium concentration and deposition after the nuclear power plant accident in Fukushima.

    PubMed

    Tsuji, Hideki; Yasutaka, Tetsuo; Kawabe, Yoshishige; Onishi, Takeo; Komai, Takeshi

    2014-09-01

    This study involved measurement of concentrations of dissolved and particulate radiocesium ((134)Cs and (137)Cs) in river water, and determination of the quantitative relations between the amount of deposited (137)Cs and (137)Cs concentrations in river waters after the Fukushima Daiichi nuclear power plant accident. First, the current concentrations of dissolved and particulate (134)Cs·(137)Cs were determined in a river watershed from 20 sampling locations in four contaminated rivers (Abukuma, Kuchibuto, Shakado, and Ota). Distribution characteristics of different (137)Cs forms varied with rivers. Moreover, a higher dissolved (137)Cs concentration was observed at the sampling location where the (137)Cs deposition occurred much more heavily. In contrast, particulate (137)Cs concentration along the river was quite irregular, because fluctuations in suspended solids concentrations occur easily from disturbance and heavy precipitation. A similar tendency with dissolved (137)Cs distribution was observed for the (137)Cs concentration per unit weight of suspended solids. Regression analysis between deposited (137)Cs and dissolved/particulate (137)Cs concentrations was performed for the four rivers. The results showed a strong correlation between deposited (137)Cs and dissolved (137)Cs, and a relatively weak correlation between deposited (137)Cs and particulate (137)Cs concentration for each river. However, if the particulate (137)Cs concentration was converted to (137)Cs concentration per unit weight of suspended solid, the values showed a strong correlation with deposited (137)Cs.

  10. Deformation Behavior of Chalk Studied Close to In Situ Reservoir Conditions

    NASA Astrophysics Data System (ADS)

    Omdal, E.; Madland, M. V.; Kristiansen, T. G.; Nagel, N. B.; Korsnes, R. I.; Hiorth, A.

    2010-09-01

    A laboratory test program, which simulated reservoir conditions of pressure and temperature, was conducted on outcrop and reservoir chalk samples of various porosities. All the samples experienced a stress path following uniaxial strain condition K 0 that led to compaction failure, i.e. pore collapse. The experiments were loaded by depletion of pore pressure conducted under load controlled conditions. This depletion phase was followed by a creep period, where time-dependent deformation was monitored. The intention of creating such reservoir condition in these laboratory experiments was to gain knowledge of the nature of chalk compaction. Chalk is an important reservoir rock for the oil and gas industry with unique storage capability with porosities up toward 50%. However, this rock is also very weak which has resulted in significant reservoir compaction and in turn severe seabed subsidence and casing failure. Mapping of the mechanical behavior of chalk in terms of deformation is thus decisive for a proper understanding of these reservoirs. The results of this study show that chalk is indeed a rate-dependent material under laboratory loading conditions as time effects were revealed as the loading rate was varied. However, the results raise uncertainty about the importance of rate dependency for chalk under completely drained conditions. Further, such high-porosity chalk suffers for substantial plastic strains and obvious strain hardening. Indeed, a relation between deformation/porosity and hardening is proposed by the introduction of real-time modulus values. Time-dependent deformation, also called creep was influenced by the depletion phase, as consolidation or transient creep influenced the deformation response for as much as 175 h after a change in load. This indicates that transient creep is dependent on the stress history. However, observations suggest the existence of a universal mechanism for steady state creep, governed by neither the initial porosity nor

  11. Subaerial Chalk Cliff Failures on the English Channel Coast, Based on Field Data From Recent Collapses

    NASA Astrophysics Data System (ADS)

    DUPERRET, A.; MARTINEZ, A.; GENTER, A.; MORTIMORE, R. N.; WATREMEZ, P.

    2001-12-01

    The chalk cliffs along the English Channel coast are currently retreating at a mean rate of 0.5 m/year. However, the erosion is not constant over time, but occurs by catastrophic collapses. For the last three years, a minimum of 40 collapses have been observed along the French chalk coastline (120 km long) and about 10 collapses along the English chalk coastline (40 km long). The observed collapsed volumes are varying from 150 000 m3 (Beachy Head, UK) to a few m3, whereas the cliff heights are varying from 20 to 200m. Two kinds of scar extension have been observed on the cliff face: either the lower part only with few volumes involved, either the whole cliff height for the largest events. Two main cases of scar shape have been evidenced: (1) scar with a vertical upper part and a curved lower part with large striations and crushed chalk (Puys, France). The rupture process is an overall sliding process, with tearing of the upper part of the cliff and shearing in its lower part. The failure is mainly controlled by rain-fall and occurred by water pressure increase on impervious marl seams of the chalk (Duperret et al., in press, JCR). (2) scar with a regular and rectilinear profile, without any striation (Birling Gap, UK). The rupture propagates along pre-existing joint sets, parallel oriented to the cliff face. Locally, pre-existing large-scale transverse fractures may bound the lateral propagation of the scar. Where the scars extend all over the cliff height, the failure is mainly controlled by continental water infiltration. However the role of water through fractured chalk may differ according to the fracture pattern. Where the scars are restrained to the lower part of the cliff, the upward extension of the scars are bounded by lithological features of the chalk, as horizontal flint bands or stratification. In this case, the role of marine parameters, as wave impact at the toe of the cliff may be invoked as a significant triggering parameter contributing to failure

  12. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs, D

    2007-11-15

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90 and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction, for {sup 137}Cs removal. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239 and Pu-240. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.

  13. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs, D

    2008-01-22

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90 and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction, for Cs-137 removal. The MST and separated Cs-137 will be encapsulated into a borosilicate glass waste form for eventual entombment at the federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239 and Pu-240. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.

  14. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs D. T.; Poirier, M. R.; Barnes, M. J.; Stallings, M. E.; Nyman, M. D.

    2005-11-22

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 137}Cs, {sup 90}Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for {sup 137}Cs removal, and sorption of {sup 90}Sr and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the baseline MST material.

  15. Mineralization of 2,4-D, mecoprop, isoproturon and terbuthylazine in a chalk aquifer.

    PubMed

    Kristensen, G B; Sørensen, S R; Aamand, J

    2001-06-01

    The potential to mineralize 2,4-dichlorophenoxyacetic acid (2,4-D), mecoprop, isoproturon and terbuthylazine was studied in soil and aquifer chalk sampled at an agricultural field near Aalborg, Denmark. Laboratory microcosms were incubated for 258 days under aerobic conditions at 10 degrees C with soil and chalk from 0.15-4.45 m below the surface. The [ring-U-14C]-labeled herbicides were added to obtain a concentration of 6 micrograms kg-1 and mineralization was measured as evolved [14C]carbon dioxide. The herbicides were readily mineralized in soil from the plough layer, except for terbuthylazine, which was mineralized only to a limited extent. In the chalk, lag periods of at least 40 days were observed, and a maximum of 51%, 33% and 6% of the added 2,4-D, mecoprop and isoproturon, respectively, were recovered as [14C]carbon dioxide. Large variations in both rate and extent of mineralization were observed within replicates in chalk. No mineralization of terbuthylazine in chalk was observed. As a measure of the general metabolic activity towards aromatic compounds, [ring-U-14C]-benzoic acid was included. It was readily mineralized at all depths.

  16. Reactive transport modelling of groundwater chemistry in a chalk aquifer at the watershed scale

    NASA Astrophysics Data System (ADS)

    Mangeret, A.; De Windt, L.; Crançon, P.

    2012-09-01

    This study investigates thermodynamics and kinetics of water-rock interactions in a carbonate aquifer at the watershed scale. A reactive transport model is applied to the unconfined chalk aquifer of the Champagne Mounts (France), by considering both the chalk matrix and the interconnected fracture network. Major element concentrations and main chemical parameters calculated in groundwater and their evolution along flow lines are in fair agreement with field data. A relative homogeneity of the aquifer baseline chemistry is rapidly reached in terms of pH, alkalinity and Ca concentration since calcite equilibrium is achieved over the first metres of the vadose zone. However, incongruent chalk dissolution slowly releases Ba, Mg and Sr in groundwater. Introducing dilution effect by rainwater infiltration and a local occurrence of dolomite improves the agreement between modelling and field data. The dissolution of illite and opal-CT, controlling K and SiO2 concentrations in the model, can be approximately tackled by classical kinetic rate laws, but not the incongruent chalk dissolution. An apparent kinetic rate has therefore been fitted on field data by inverse modelling: 1.5 × 10- 5 molchalk L - 1water year - 1. Sensitivity analysis indicates that the CO2 partial pressure of the unsaturated zone is a critical parameter for modelling the baseline chemistry over the whole chalk aquifer.

  17. Improving UK Chalk hydrometeorology across spatial scales using a small hydrometeorological network

    NASA Astrophysics Data System (ADS)

    Rosolem, Rafael; Iwema, Joost; Rahman, Mostaquimur; Desilets, Darin; Koltermann da Silva, Juliana

    2016-04-01

    Chalk in the UK acts as a primary aquifer providing up to 80% of the public water supply locally. Chalk outcrops are located over most of southern and eastern England. Despite its importance, the characterization of Chalk in hydrometeorological models is still very limited. There is a need for a comprehensive and coherent integration of observations and modeling efforts across spatial scales for better understanding Chalk hydrometeorology. Here we introduce the "A MUlti-scale Soil moisture-Evapotranspiration Dynamics" (AMUSED) project. AMUSED goal is to better identify the key dominant processes controlling changes in soil moisture and surface fluxes (e.g., evapotranspiration) across spatial scales by combining ground-based observations with hydrometeorological models and satellite remote sensing products. The AMUSED observational platform consists of three sites located in Upper Chalk region of the Lambourn Catchment located in southern England covering approximately 2 square-km characterized by distinct combinations of soil and vegetation types. The network includes standard meteorological measurements, an eddy covariance system for turbulent fluxes and cosmic-ray neutron sensors for integrated soil moisture estimates at intermediate scales. Here we present our initial results from our three sites.

  18. Alternative dispositioning methods for HEU spent nuclear fuel at the Savannah River Site

    SciTech Connect

    Krupa, J.F.; McKibben, J.M.; Parks, P.B.; DuPont, M.E.

    1995-11-01

    The United States has a strong policy on prevention of the international spread of nuclear weapons. This policy was announced in Presidential Directive PDD-13 and summarized in a White House press release September 27, 1993. Two cornerstones of this policy are: seek to eliminate where possible the accumulation of stockpiles of highly- enriched uranium or plutonium; propose{hor_ellipsis}prohibiting the production of highly-enriched uranium (HEU) or plutonium for nuclear explosives purposes or outside international safeguards. The Department of Energy is currently struggling to devise techniques that safely and efficiently dispose of spent nuclear fuel (SNF) while satisfying national non-proliferation policies. SRS plans and proposals for disposing of their SNF are safe and cost effective, and fully satisfy non-proliferation objectives.

  19. Overview of the Government of Canada Nuclear Legacy Liabilities Program - 13551

    SciTech Connect

    Metcalfe, D.; McCauley, D.; Miller, J.; Brooks, S.

    2013-07-01

    Nuclear legacy liabilities have resulted from more than 60 years of nuclear research and development carried out on behalf of Canada. The liabilities are located at Atomic Energy of Canada Limited's (AECL) Chalk River Laboratories in Ontario and Whiteshell Laboratories in Manitoba, as well as three shutdown prototype reactors in Ontario and Quebec that are being maintained in a safe storage state. Estimated at about $7.4 billion (current day dollars), these liabilities consist of disused nuclear facilities and associated infrastructure, a wide variety of buried and stored waste, and contaminated lands. In 2006, the Government of Canada adopted a long-term strategy to deal with the nuclear legacy liabilities and initiated a five-year, $520 million start-up phase, thereby creating the Nuclear Legacy Liabilities Program (NLLP). The Government of Canada renewed the NLLP in 2011 with a $439-million three-year second phase that ends March 31, 2014. The projects and activities carried out under the Program focus on infrastructure decommissioning, environmental restoration, improving the management of legacy radioactive waste, and advancing the long-term strategy. The NLLP is being implemented through a Memorandum of Understanding between Natural Resources Canada (NRCan) and AECL whereby NRCan is responsible for policy direction and oversight, including control of funding, and AECL is responsible for implementing the program of work and holding and administering all licences, facilities and lands. (authors)

  20. Isotopic signature of selected lanthanides for nuclear activities profiling using cloud point extraction and ICP-MS/MS.

    PubMed

    Labrecque, Charles; Lebed, Pablo J; Larivière, Dominic

    2016-05-01

    The presence of fission products, which include numerous isotopes of lanthanides, can impact the isotopic ratios of these elements in the environment. A cloud point extraction (CPE) method was used as a preconcentration/separation strategy prior to measurement of isotopic ratios of three lanthanides (Nd, Sm, and Eu) by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). To minimise polyatomic interference, the combination of interferents removal by CPE, reaction/collision cell conditions in He and NH3 mode and tandem quadrupole configuration was investigated and provided optimal results for the determination of isotopic ratio in environmental samples. Isotopic ratios were initially measured in San Joaquin soil (NIST-2709a), an area with little contamination of nuclear origin. Finally, samples collected from three sites with known nuclear activities (Fangataufa Lagoon in French Polynesia, Chernobyl and the Ottawa River near Chalk River Laboratory) were analysed and all exhibited altered isotopic ratios for (143/145)Nd, (147/149)Sm, and (151/153)Eu. These results demonstrate the potential of CPE and ICP-MS/MS for the detection of altered isotopic ratio in environmental samples collected in area subjected to nuclear anthropogenic contamination. The detection of variations in these isotopic ratios of fission products represents the first application of CPE in nuclear forensic investigations of environmental samples.

  1. Holocene evolution of coastal chalk cliffs in Normandy (NW France) as evidenced by onshore-offshore high resolution geomorphology

    NASA Astrophysics Data System (ADS)

    Duguet, Timothée; Duperret, Anne; Costa, Stéphane; Regard, Vincent; Maillet, Grégoire

    2017-04-01

    Key words: erosion, rocky coast, cliffs, shore platform, watersheds, cosmogenic dating The chalk cliffs coastline extends to 120 km long in Normandy. It suffers from high erosion rates with a mean of about 0.15 m/y. The shore platforms extending from the cliff base to the sea, keep structural marks of the cliff erosion during long periods, i.e. the Holocene. Therefore it is essential to take an active interest in their morphology and their evolution to better understand cliff erosion timing. A land-sea Digital Elevation Model (DEM) has been produced for Mesnil-Val and Criel-sur-Mer sites (Seine Maritime), with the merge of topographic data (RGE alti, IGN) and shallow bathymetric data from three oceanographic Cruises, CROCOLIT-1 and 3 (Duperret, 2013) and SPLASHALIOT-2 (Maillet, 2014). Valleys that have more or less incised Turonian-Coniacian chalk cliffs occupy the landward part of study sites. The N130E V-shaped incised Mesnil-Val dry valley is elevated at 29 m high above the shore platform level, whereas the N175E Criel-sur-Mer flat valley, extending on 700 m wide and occupied by the Yères river, is directly connected to the shore platform. Offshore, the shore platform morphology varies from Criel-sur-Mer (North) to Mesnil-Val (South). Northern part of the study site is characterized by 1 km wide shore platform made of an overlay of flat steps controlled by normal faults. Southern part highlights a shore platform with a seaward edge located at about 500 m from the cliff face and strictly parallel oriented to the present-day coastline over a minimum distance of 5 km, without fracture control. The shore platform seaward edge is more or less steep and is always localized below the limit of the lowest tide level. Its origin could be related to the in-depth waves influence or to a past sea level stagnation. We aim to identify the origin of this seaward edge, using cosmogenic 10Be dating in order to develop a chalky shore platform evolution model. It is necessary to

  2. Dynamic depositional and early diagenetic processes in a deep-water shelf setting, upper cretaceous Austin Chalk, North Texas

    SciTech Connect

    Hovorka, S.D.; Nance, H.S.

    1994-12-31

    The Austin Chalk of north Texas was deposited on a deep-water shelf north of the Sea Marcos Platform during a worldwide Coniacian and Santonian sea-level highstand. Transgressive (lowermost lower Austin Chalk), highstand (uppermost lower Austin Chalk), and regressive (middle and upper Austin Chalk) phases of cyclic chalk and marl sedimentation are recognized in excavations and tunnels created in Ellis County for the Superconducting Super Collider provide new evidence of sediment transport during Austin Chalk deposition. During transgression, bottom currents syndepositionally reworked nannoplankton oozes, incising channels as much as 120 ft across and 8 ft deep. Weakly burrowed channel fills having preservation of fine lamination document rapid infilling. Channel fills are composed of pyritized and carbonized wood and Inoceramus lag deposits, pellets, echinoderm fragments, and globigerinid grainstones, and coccolith ooze. During maximum highstand, bottom reworking was suppressed. Detrital content of highstand marls is low (>20 percent); organic content is high (1.4 to 3.5 percent). Coccolith preservation is excellent because of minimal diagenetic alteration. Regression is marked by resumed channel cutting and storm-bed winnowing in the middle and upper Austin Chalk. Suppressed resistivity log response and recessive weathering characteristics of the middle Austin Chalk are not primarily related to depositional environment but rather to increased input of volcanic ash during the accumulation of this interval. Early stabilization of ash produced clay-coated microfabrics in sediments that are otherwise similar to the transgressive deposits.

  3. Study of a conceptual nuclear energy center at Green River, Utah. Site selection

    SciTech Connect

    Not Available

    1981-08-01

    The siting requirements are described for a NEC. The methodology used, primary and secondary screening criteria and the results and conclusions are also presented. Appended to the report are detailed discussions of two siting factors, and evaluation of Nuclear Regulatory Commission (NRC) demographic siting criteria and a fatal flaw analyses for terrestrial and aquatic ecology.

  4. Decay-Series Disequilibria in a Chalk Aquifer : Characterisation of Water-Rock Interaction

    NASA Astrophysics Data System (ADS)

    Hubert, A.; Bourdon, B.; Pili, E.

    2003-12-01

    We have studied uranium-series disequilibria in a chalk aquifer and the unsaturated zone above it in order to characterise the time scales of radionuclide migration from the water recharge zone of the aquifer to the nearby river. Our field area is located in Champagne (France). The aquifer is characterized by a double porosity : matrix and fracture, providing both a fast and a slow pathways for water flow. We have collected both carbonate rocks and groundwater samples from boreholes and spring and river water from the same area. Rock/water interaction inside the aquifer induces dissolution and reprecipitation of carbonates, together with a mobilization of uranium, and (-recoil effect results in preferential mobilization of daughter nuclides. We have measured uranium and thorium isotopes for carbonates samples from the aquifer by TIMS and multi-collection ICP-MS. The fractionation of uranium and thorium isotopes is distinctive in the various parts of the aquifer. Rock samples from the saturated zone show a depletion in 234U with a (234U/238U) ratio ranging from 0.945 to 0.993 (ñ 0.005). This indicates that uranium 234U has been released by rock/water interaction over the last million year. Nevertheless, rock samples from the water table oscillation zone display a (234U/238U) activity ratio greater than 1 and range from 1.002 to 1.052 (ñ 0.005), suggesting uranium reprecipitation possibly by a redox front. (230Th/238U) ratios range from 1.25 to 1.59 (ñ 0.03) in both the saturated and vadose zone, whilst (230Th/232Th) ratios vary from 1.89 to 5.68 (ñ 0.05) with the highest values for the water table oscillation zone. The 238U-230Th system suggests the existence of a iron oxihydroxide and/or silicate phases which influence the redeposition and/or adsorption of elements inside the zone of water oscillation. Modelling is in progress in order to determine leaching rate of the radionuclides in the substratum together with the adsorption/desorption rate constants on

  5. U-series nuclides migration from the vadose zone to a chalk aquifer

    NASA Astrophysics Data System (ADS)

    Hubert, A.; Bourdon, B.; Pili, E.

    2003-04-01

    We have studied the uranium-series disequilibria in chalk aquifer and the vadose zone above it in order to characterise the time scales of radionuclides migration from the water recharge zone of the aquifer to the river. Our field area is located in Champagne (France). The aquifer is characterized by a double porosity: matrix and fracture, providing both a fast and a slow pathways for water flow. We have collected both carbonate rocks and groundwater samples from boreholes and spring and river water from the same area. The boreholes have been drilled along a flow line. Rock/water interaction inside the aquifer induces dissolution and reprecipitation of carbonates, together with a mobilisation of uranium, and additionally the decay of radionuclides results in a-recoil effect particularly for the 234U--238U pair. We have measured uranium and thorium isotopes for carbonates samples from the aquifer by TIMS and multi-collection ICP-MS. The fractionation of uranium and thorium nuclides is distinctive in the various parts of the aquifer. Rock samples from the saturated zone show a depletion in 234U with a (234U/238U) ratio ranging from 0.945 to 0.993 (± 0.005). This indicates that uranium 234U has been released by rock/water interaction over the last million year. Nevertheless, rock samples from the vadose zone display an activity ratio 234U/238U above 1 and range from 1.002 to 1.052 (± 0.005), suggesting uranium reprecipitation possibly by a redox front. (230Th/238U) ratio range from 1.25 to 1.59 (± 0.03) in both saturated and vadose zone, whilst (230Th/232Th) ratio vary from 1.89 to 5.68 (± 0.05) with the highest values for the vadose zone. The 234U--230Th system shows a significant mobility of uranium less than 300 000 years ago within the aquifer. We are curently analysing water samples which will provide us further insights on the migration timescale of uranium-series nuclides in groundwater and will document the processes of groundwater/carbonate interaction.

  6. Chalk-Ex: An Ocean Optics Manipulation Experiment on the Fate of Calcite Particles

    NASA Astrophysics Data System (ADS)

    Balch, W. M.; Plueddemann, A. J.; Pilskaln, C. H.; Dam, H. G.; McManus, G. B.; Goes, J. I.

    2002-12-01

    Large-scale manipulation experiments such as Iron-Ex have allowed the testing of fundamental hypotheses about the ocean, not easily approachable with typical bench-style experimentation. Manipulation experiments provide tremendous insight by integrating the entire biogeochemical system into the results; they arguably give some of the most valuable tests for today's complex numerical models, at relatively fine spatial scales. One poorly understood biogeochemical cycle is that of CaCO3. About one quarter of the earth's marine sediment is CaCO3, much of which is composed of small coccoliths. How these particles are transported to the sea floor is still an open question. In this talk, we will present an overview of experiments from November 2001 from Continental Shelf and Slope waters off the NE U.S., in which Cretaceous coccolith chalk was dispersed into a patch of about 1.5 km2 (dubbed "Chalk-Ex"). The chalk's extremely well-defined light scattering and stable isotope properties made it possible to monitor the patch evolution and examine the importance of physical processes (horizontal shear, vertical mixing), grazing (macro- and micro-zooplankton), aggregation, interactions with dissolved organic carbon and sinking (estimated with drifting sediment traps). Lagrangian drifters were used to follow the patch and an instrumented drifter was used to characterize T-S properties over several days. From a particle perspective, the power of Chalk-Ex was that it simplified particle turn-over calculations. That is, while most particle experiments must simultaneously quantify both the production and loss terms of the particles in question (often with limited statistical precision), in Chalk-Ex, the production term was known almost exactly, so that we could focus on subsequent loss terms. The process that appeared to be most important to the patch evolution was horizontal dispersion at the "injection density", driven by shear between the surface and the maximum injection depth

  7. Bringing mini-chalk talks to the bedside to enhance clinical teaching

    PubMed Central

    Pitt, Michael B.; Orlander, Jay D.

    2017-01-01

    ABSTRACT Chalk talks – where the teacher is equipped solely with a writing utensil and a writing surface – have been used for centuries, yet little has been written about strategies for their use in medical education. Structured education proximal to patient encounters (during rounds, at the bedside, or in between patients in clinic) maximizes the opportunities for clinical learning. This paper presents a strategy to bring mini-chalk talks (MCTs) to the bedside as a practical way to provide relevant clinical teaching by visually framing teachable moments. Grounded in adult learning theory, MCTs leverage teaching scripts to facilitate discussion, involve learners at multiple levels, and embrace the increased retention associated with visual aids. These authors provide specific recommendations for the design and implementation of MCT sessions including what topics work well, how to prepare, and how to involve and engage the learners. Abbreviations: ADHD: Attention Deficit Hyperactivity Disorder; MCT: Mini-chalk talks PMID:28178911

  8. Particle transport in unsaturated fractured chalk under arid conditions.

    PubMed

    Weisbrod, Noam; Dahan, Ofer; Adar, Eilon M

    2002-05-01

    A series of field and laboratory experiments were conducted to study the mechanisms of particle detachment and transport from fractures in vadose chalk. Experiments of intermittent flow events along fracture surfaces were carried out in the laboratory. In the field, water was percolated from land surface via a discrete fracture into a compartmental sampler installed inside a horizontal corehole located I m below the surface. The mass, size distribution, and composition of the particles drained from the fracture voids were examined along with flow rates and salt dissolution. Two boreholes penetrating the underlying saturated zone were sampled and analyzed for colloidal concentration and composition. Most of the particle and solute release at the drained effluents occurred during the first several hours of flow, but erratic pulses of particles were still observed after long periods of time. Most of the detached particles had a mean diameter of >2 microm, while the mobile colloidal phase in the groundwater had a mean diameter of approximately 1 microm. Mineralogical composition of the groundwater colloids and the particles detached from the upper vadose fracture were similar. Laboratory observations demonstrated the importance of the existence of a coating layer, made of weathered particles and salts, on particle detachment. The results of this study suggest that: (1) particle detachment causes flow-rate variability in the unsaturated fracture; (2) the mechanisms of particle detachment and salt dissolution within the fracture are linked: and (3) although most of the detached particles are large and likely to accumulate inside fractures, some colloidal particles also eroded from the fracture void and are likely to be transported to the groundwater.

  9. Phosphorus-31 nuclear magnetic resonance assignments of biogenic phosphorus compounds in sediment of an artificial Fuyangxin River, China.

    PubMed

    Zhang, Wenqiang; Shan, Baoqing; Zhang, Hong; Tang, Wenzhong

    2014-03-01

    River eutrophication could drastically influence the phosphorus (P) in the water and sediment. To understand the biogenic-P species, distribution and bioconversion, five sediment samples were collected from an artificial river, and analyzed by phosphorus-31 nuclear magnetic resonance ((31)P-NMR). The P pollution in the water and sediment were both severe. The average concentrations of total P (TP) and solution reactive phosphorus in the water were 3.0 and 2.6 mg L(-1), respectively, which surpass grade V of the national quality standard (China) and should not be used for any purpose. The river sediments accumulated significant inorganic phosphorus (Pi) and organic phosphorus (Po); in the P fractionation, the rank order of the P fractions was as follows: Ca-P > NaOH-Pi > Res-P > KCl-P > NaOH-Po, with average relative proportions of 25.1:16.8:6.6:1.7:1:0. Six P compounds were detected in the NaOH-EDTA extract by (31)P-NMR. Mono-P (8.96-29.58 %) was the dominant forms of biogenic-P, and other smaller fractions of biogenic-P were also observed, including pyro-P (0.22-0.86 %), DNA-P (0.75-2.03 %), phon-P (0-1.57 %), and lipids-P (0-2.66 %). The TP and biogenic-P decreased along the direction of flows, with their average relative proportions 7.97:1.20:1.49:1.00:1.00 and 40.87:2.34:3.46:1.60:1 from the upstream to downstream, respectively. The concentration and species of Po in NaOH-Po were lower than found in (31)P-NMR analysis in this research. Thus, the use of 0.25 M NaOH and 50 mM EDTA extracts and solution (31)P-NMR analysis was a more accurate method for quantifying biogenic-P in the river sediments than P fractionation.

  10. Factors controlling spatial and temporal patterns of multiple pesticide compounds in groundwater (Hesbaye chalk aquifer, Belgium).

    PubMed

    Hakoun, Vivien; Orban, Philippe; Dassargues, Alain; Brouyère, Serge

    2017-04-01

    Factors governing spatial and temporal patterns of pesticide compounds (pesticides and metabolites) concentrations in chalk aquifers remain unclear due to complex flow processes and multiple sources. To uncover which factors govern pesticide compound concentrations in a chalk aquifer, we develop a methodology based on time series analyses, uni- and multivariate statistics accounting for concentrations below detection limits. The methodology is applied to long records (1996-2013) of a restricted compound (bentazone), three banned compounds (atrazine, diuron and simazine) and two metabolites (deethylatrazine (DEA) and 2,6-dichlorobenzamide (BAM)) sampled in the Hesbaye chalk aquifer in Belgium. In the confined area, all compounds had non-detects fractions >80%. By contrast, maximum concentrations exceeded EU's drinking-water standard (100 ng L(-1)) in the unconfined area. This contrast confirms that recent recharge and polluted water did not reach the confined area, yet. Multivariate analyses based on variables representative of the hydrogeological setting revealed higher diuron and simazine concentrations in the southeast of the unconfined area, where urban activities dominate land use and where the aquifer lacks protection from a less permeable layer of hardened chalk. At individual sites, positive correlations (up to τ=0.48 for bentazone) between pesticide compound concentrations and multi-annual groundwater level fluctuations confirm occurrences of remobilization. A downward temporal trend of atrazine concentrations likely reflects decreasing use of this compound over the last 28 years. However, the lack of a break in concentrations time series and maximum concentrations of atrazine, simazine, DEA and BAM exceeding EU's standard post-ban years provide evidence of persistence. Contrasting upward trends in bentazone concentrations show that a time lag is required for restriction measures to be efficient. These results shed light on factors governing pesticide

  11. Unsaturated flow and solute transport through the Chalk: Tracer test and dual permeability modelling

    NASA Astrophysics Data System (ADS)

    Van den Daele, Gerd F. A.; Barker, John A.; Connell, Luke D.; Atkinson, Tim C.; Darling, W. G.; Cooper, J. D.

    2007-08-01

    SummaryA tracer test was carried out in the unsaturated Chalk at the Fleam Dyke research site in Cambridgeshire, UK, to investigate the role of the Chalk fractures and matrix in unsaturated flow and solute transport. The experiment, under natural rainfall conditions, involved distributing deuterated water on a grass-covered lysimeter (a cube of volume 125 m 3) and on an adjacent 4 m × 4 m field plot. Tracer migration was monitored through regular core sampling and collection of lysimeter drainage water. The presence of occasional secondary peaks in sampling of the vertical tracer profile suggested the occurrence of fracture flow, allowing some tracer to bypass the Chalk matrix. However, in the 15 months following application, none of the tracer was detected in the lysimeter drainage at 5 m depth. Modelling of the tracer results was undertaken with the 1-D numerical transient dual permeability model MACRO 5.0, initially developed for macroporous soils. Modelling results showed that MACRO 5.0 could reliably simulate transient recharge through the Chalk. The simulations suggested that fracture flow is important at the site, but that it is only initiated at 1 m depth or deeper. The extent of fracture flow appeared to be highly variable in different layers of the profile, varying between 40% and 85% of the cumulative flux, mainly depending on the saturated hydraulic conductivity of the matrix. Diffusion between the fractures and the matrix tended to equalize solute concentrations in both flow domains, although solute bypass through the fractures occurred in some Chalk strata. Besides diffusive exchange, the modelling stressed the importance of advective exchange of solutes. The results suggest that the Chalk aquifer at the Fleam Dyke site is only moderately vulnerable to pollution, even though for moderate rainfall conditions some bypass flow was possible.

  12. Chalk, What Chalk?

    ERIC Educational Resources Information Center

    Butler, Loren L.

    2004-01-01

    When it comes to technological wizardry in the classroom, interactive whiteboards stand on the cutting edge of the future. Students seem innately able to manipulate any type of computerized equipment, and, more important, they are highly motivated to engage in "techno-discovery." It is the duty of every educator to facilitate further discovery and…

  13. Chalk, What Chalk?

    ERIC Educational Resources Information Center

    Butler, Loren L.

    2004-01-01

    When it comes to technological wizardry in the classroom, interactive whiteboards stand on the cutting edge of the future. Students seem innately able to manipulate any type of computerized equipment, and, more important, they are highly motivated to engage in "techno-discovery." It is the duty of every educator to facilitate further discovery and…

  14. A simple model of variable residence time flow and nutrient transport in the chalk

    NASA Astrophysics Data System (ADS)

    Jackson, Bethanna M.; Wheater, Howard S.; Mathias, Simon A.; McIntyre, Neil; Butler, Adrian P.

    2006-10-01

    SummaryA basic problem of modelling flow and transport in Chalk catchments arises from the existence of a deep unsaturated zone, with complex interactions between flow in fractures and water held in the fine pores of the rock matrix. The response of the water table to major infiltration episodes is rapid (of the order of days). However, chemical signals are strongly damped, suggesting that this water is of varying age, with a corresponding mixed history of nutrient loading. Clearly this effect should be represented in any model of nutrients in Chalk systems. The applicability of simplified physically-based model formulations to represent the dual response in an integrated way has been investigated by a variety of researchers, but it has been shown that these approximations break down in application to the Chalk. Mathias et al. [Mathias, S., Butler, A.P., Jackson, B.M., Wheater, H.S., this issue. Characterising flow in the Chalk unsaturated zone. In: Wheater, H.S., Peach, D., Neal, C, editors, Hydrology on LOCAR in the Pang/Lambourn, special issue of J. Hydrol, doi:10.1016/j.jhydrol.2006.04.010] present a dual permeability model that explains the observed response, but such complex formulations are not readily incorporated in catchment-scale nutrient models. This paper reviews previous approaches to modelling the Chalk and then presents a pragmatic approach, with transport of solute and water through the unsaturated zone treated separately, and combined at the water table. Varying residence times are included through considering the distance between the water table and the soil surface, and the history of nutrient application at the surface. If an average rate of downwards migration of the nutrients is assumed, it is possible to derive a travel time distribution of nitrate transport to the water table using a DTM (digital terrain model) map of elevation and information on groundwater levels. This distribution can then be implemented through difference equations. The

  15. The surface reactivity of chalk (biogenic calcite) with hydrophilic and hydrophobic functional groups

    NASA Astrophysics Data System (ADS)

    Okhrimenko, D. V.; Dalby, K. N.; Skovbjerg, L. L.; Bovet, N.; Christensen, J. H.; Stipp, S. L. S.

    2014-03-01

    The surface properties of calcium carbonate minerals play an important role in a number of industrial and biological processes. Properties such as wettability and adsorption control liquid-solid interface behaviour and thus have a strong influence on processes such as biomineralisation, remediation of aquifers and oil recovery. We investigated how two model molecules of different polarity, namely water and ethanol, interact with reservoir and outcrop chalk samples and we compared their behaviour with that of pure, inorganically precipitated calcite. Thermodynamic quantities, such as the work of wetting, surface energy and isosteric adsorption enthalpy, were determined from vapour adsorption isotherms. The chalks were studied fresh and after extraction of organic residues that were originally present in these samples. The work of wetting correlates with the amount of organic matter present in the chalk samples but we observed a fundamental difference between the adsorption properties of chalk and pure, inorganically precipitated calcite toward the less polar, ethanol molecule. Further analysis of the chemical composition of the organic matter extracted from the chalk samples was made by gas chromatography (GC-MS). Monitoring surface composition by X-ray photoelectron spectroscopy (XPS) before and after extraction of the organic material, and with atomic force microscopy (AFM), showed that nanometer sized clay crystals observed on the chalk particle surfaces could be an important part of the reason for the differences. Removal of the extractable portion of the hydrocarbons liberates adsorption sites that have different wetting properties than the rest of the chalk and these have an energy distribution that is similar to clays. Thus, the results exemplify the complexity of biogenic calcite adsorption behaviour and demonstrate that chalk wetting in drinking water aquifers as well as oil reservoirs is controlled partly by the nanoparticles of clay that have grown on the

  16. Authigenic kaolinite and associated pyrite in chalk of the Cretaceous Niobrara Formation, Eastern Colorado.

    USGS Publications Warehouse

    Pollastro, R.M.

    1981-01-01

    Cores from the Smoky Hill Chalk Member of the Cretaceous Niobrara Formation have several zones containing authigenic kaolinite as spherical, moldic, polycrystalline aggregates that occur within single or multichambered foraminiferal tests and are commonly associated with framboidal pyrite. Such kaolinite is inferred to result from volcanic ash deposited during chalk sedimentation. Shortly after burial, a colloidal aluminous gel or solution formed from the unstable ash and moved into organic-rich foraminiferal tests, where sulfate-reducing bacteria created a favorable microenvironment for the simultaneous crystallization of kaolinite and pyrite. -Author

  17. Virtual Reality Lab Assistant

    NASA Technical Reports Server (NTRS)

    Saha, Hrishikesh; Palmer, Timothy A.

    1996-01-01

    Virtual Reality Lab Assistant (VRLA) demonstration model is aligned for engineering and material science experiments to be performed by undergraduate and graduate students in the course as a pre-lab simulation experience. This will help students to get a preview of how to use the lab equipment and run experiments without using the lab hardware/software equipment. The quality of the time available for laboratory experiments can be significantly improved through the use of virtual reality technology.

  18. Virtual Reality Lab Assistant

    NASA Technical Reports Server (NTRS)

    Saha, Hrishikesh; Palmer, Timothy A.

    1996-01-01

    Virtual Reality Lab Assistant (VRLA) demonstration model is aligned for engineering and material science experiments to be performed by undergraduate and graduate students in the course as a pre-lab simulation experience. This will help students to get a preview of how to use the lab equipment and run experiments without using the lab hardware/software equipment. The quality of the time available for laboratory experiments can be significantly improved through the use of virtual reality technology.

  19. Department of Energy Programmatic Spent Nuclear Fuel Management and Idaho National Engineering Laboratory Environmental Restoration and Waste Management Programs Draft Environmental Impact Statement. Volume 1, Appendix C, Savannah River Site Spent Nuclear Fuel Mangement Program

    SciTech Connect

    Not Available

    1994-06-01

    The US Department of Energy (DOE) is engaged in two related decision making processes concerning: (1) the transportation, receipt, processing, and storage of spent nuclear fuel (SNF) at the DOE Idaho National Engineering Laboratory (INEL) which will focus on the next 10 years; and (2) programmatic decisions on future spent nuclear fuel management which will emphasize the next 40 years. DOE is analyzing the environmental consequences of these spent nuclear fuel management actions in this two-volume Environmental Impact Statement (EIS). Volume 1 supports broad programmatic decisions that will have applicability across the DOE complex and describes in detail the purpose and need for this DOE action. Volume 2 is specific to actions at the INEL. This document, which limits its discussion to the Savannah River Site (SRS) spent nuclear fuel management program, supports Volume 1 of the EIS. Following the introduction, Chapter 2 contains background information related to the SRS and the framework of environmental regulations pertinent to spent nuclear fuel management. Chapter 3 identifies spent nuclear fuel management alternatives that DOE could implement at the SRS, and summarizes their potential environmental consequences. Chapter 4 describes the existing environmental resources of the SRS that spent nuclear fuel activities could affect. Chapter 5 analyzes in detail the environmental consequences of each spent nuclear fuel management alternative and describes cumulative impacts. The chapter also contains information on unavoidable adverse impacts, commitment of resources, short-term use of the environment and mitigation measures.

  20. Chernobyl nuclear accident hydrologic analysis and emergency evaluation of radionuclide distributions in the Dnieper River, Ukraine, during the 1993 summer flood

    SciTech Connect

    Voitsekhovitch, O.V.; Zheleznyak, M.J.; Onishi, Y.

    1994-06-01

    This report describes joint activities of Program 7.1.F, ``Radionuclide Transport in Water and Soil Systems,`` of the USA/Commonwealth of Independent States (CIS) Joint Coordinating Committee of Civilian Nuclear Reactor Safety to study the hydrogeochemical behavior of radionuclides released to the Pripyat and Dnieper rivers from the Chernobyl Nuclear Power Plant in Ukraine. These joint activities included rapid evaluation of radionuclide distributions in the Pripyat and Dnieper river system and field data evaluation and modeling for the 1993 summer flood to assist the Ukrainian government in their emergency response during the flood. In July-August 1993, heavy rainfall over the Pripyat River Catchment in Belarus and Ukraine caused severe flooding, significantly raising {sup 90}Sr concentrations in the river. Near the Chernobyl area, the maximum {sup 90}Sr concentration in the Pripyat River reached 20--25 PCi/L in early August; near the Pripyat River mouth, the concentration rose to 35 pCi/L. The peak {sup 90}Sr concentration in the Kiev Reservoir (a major source of drinking water for Kiev) was 12 pCi/L. Based on these measured radionuclide levels, additional modeling results and the assumption of water purification in a water treatment station, {sup 90}Sr concentrations in Kiev`s drinking water were estimated to be less than 8 pCi/L. Unlike {sup 90}Sr, {sup 137}Cs concentrations in the Pripyat River during the flood did not rise significantly to the pre-flood levels. Estimated {sup 137}Cs concentrations for the Kiev drinking water were two orders of magnitude lower than the drinking water standard of 500 pCi/L for {sup 137}Cs.

  1. Qualification of Programmable Electronic System (PES) equipment based on international nuclear I and C standards

    SciTech Connect

    De Grosbois, J.; Hepburn, G. A.; Olmstead, R.; Goble, W.; Kumar, V.

    2006-07-01

    Nuclear power plants (NPPs) are increasingly faced with the challenge of qualifying procured equipment, sub-components, and systems that contain digital programmed electronics for use in safety-related applications. Referred to as a 'programmable electronic system' (PES), such equipment typically contains both complex logic that is vulnerable to systematic design faults, and low voltage electronics hardware that is subject to random faults. Procured PES products or components are often only commercial grade, yet can offer reliable cost effective alternatives to custom-designed or nuclear qualified equipment, provided they can be shown to meet the quality assurance, functional safety, environmental, and reliability requirements of a particular application. The process of confirming this is referred to as application-specific product qualification (ASPQ) and can be challenging and costly. This paper provides an overview of an approach that has been developed at Atomic Energy Canada Limited (AECL) and successfully applied to PES equipment intended for use in domestic Candu R 6 nuclear power plants and special purpose reactors at Chalk River Laboratories. The approach has evolved over the past decade and has recently been adapted to be consistent with, and take advantage of new standards that are applicable to nuclear safety-related I and C systems. Also discussed are how recognized third-party safety-certifications of PES equipment to International Electrotechnical Commission (IEC) standards, and the assessment methods employed, may be used to reduce ASPQ effort. (authors)

  2. A particle assembly/constrained expansion (PACE) model for the formation and structure of porous metal oxide deposits on nuclear fuel rods in pressurized light water reactors

    NASA Astrophysics Data System (ADS)

    Brenner, Donald W.; Lu, Shijing; O'Brien, Christopher J.; Bucholz, Eric W.; Rak, Zsolt

    2015-02-01

    A new model is proposed for the structure and properties of porous metal oxide scales (aka Chalk River Unidentified Deposits (CRUD)) observed on the nuclear fuel rod cladding in Pressurized Water Reactors (PWR). The model is based on the thermodynamically-driven expansion of agglomerated octahedral nickel ferrite particles in response to pH and temperature changes in the CRUD. The model predicts that porous nickel ferrite with internal {1 1 1} surfaces is a thermodynamically stable structure under PWR conditions even when the free energy of formation of bulk nickel ferrite is positive. This explains the pervasive presence of nickel ferrite in CRUD, observed CRUD microstructures, why CRUD maintains its porosity, and variations in porosity within the CRUD observed experimentally. This model is a stark departure from decades of conventional wisdom and detailed theoretical analysis of CRUD chemistry, and defines new research directions for model validation, and for understanding and ultimately controlling CRUD formation.

  3. Probing the intrinsically oil-wet surfaces of pores in North Sea chalk at subpore resolution

    PubMed Central

    Hassenkam, T.; Skovbjerg, L. L.; Stipp, S. L. S.

    2009-01-01

    Pore surface properties control oil recovery. This is especially true for chalk reservoirs, where pores are particularly small. Wettability, the tendency for a surface to cover itself with fluid, is traditionally defined by the angle a droplet makes with a surface, but this macroscopic definition is meaningless when the particles are smaller than even the smallest droplet. Understanding surface wetting, at the pore scale, will provide clues for more effective oil recovery. We used a special mode of atomic force microscopy and a hydrophobic tip to collect matrices of 10,000 force curves over 5- × 5-μm2 areas on internal pore surfaces and constructed maps of topography, adhesion, and elasticity. We investigated chalk samples from a water-bearing formation in the Danish North Sea oil fields that had never seen oil. Wettability and elasticity were inhomogeneous over scales of 10s of nanometers, smaller than individual chalk particles. Some areas were soft and hydrophobic, whereas others showed no correlation between hardness and adhesion. We conclude that the macroscopic parameter, “wetting,” averages the nanoscopic behavior along fluid pathways, and “mixed-wet” samples have patches with vastly different properties. Development of reservoir hydrophobicity has been attributed to infiltrating oil, but these new results prove that wettability and elasticity are inherent properties of chalk. Their variability, even on single particles, must result from material originally present during sedimentation or material sorbed from the pore fluid some time later. PMID:19321418

  4. 24. ARAIII Reactor building ARA608 interior. Camera facing south. Chalk ...

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

    24. ARA-III Reactor building ARA-608 interior. Camera facing south. Chalk marks on wall indicate presence or absence of spot contamination. Ineel photo no. 3-2. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  5. Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

    SciTech Connect

    Phillips, W.S.; Rutledge, J.T.; Gardner, T.L.; Fairbanks, T.D.; Miller, M.E.; Schuessler, B.K.

    1996-11-01

    Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of five between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.

  6. Maastrichtian ammonites chiefly from the Prairie Bluff Chalk in Alabama and Mississippi

    USGS Publications Warehouse

    Cobban, W.A.; Kennedy, W.J.

    1995-01-01

    The Prairie Bluff Chalk of Alabama and Mississippi yields a diverse ammonite fauna of Maastrichtian age. Twenty-eight species, of which three are new, are recorded. The bulk of the fauna can be referred to a Discoscaphites conradi assemblage zone, but some elements in the fauna are significantly older. -Authors

  7. Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

    SciTech Connect

    Phillips, W.S.; Rutledge, J.T.; Fairbanks, T.D.

    1996-12-31

    Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of live between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.

  8. Ichnology and paleosubstrates of Austin Chalk (Cretaceous) outcrops: Southern Dallas and Ellis Counties, Texas

    SciTech Connect

    Dawson, W.C. ); Reaser, D.F. )

    1991-03-01

    Ichnofossils are abundant in outcrops of the Austin Chalk near Waxahachie, Texas (designated site of the Super-Conducting Super Collider). The abundance and diversity of ichnofossils in Austin strata contrast with the paucity of other macrofossils, except large inoceramids. The lower Austin Chalk (Coniacian) disconformably overlies the Eagle Ford Shale (Turonian). Planolites, Thalassinoides, and Chondrites are conspicuous in the lower Austin. Some lower Austin strata contain well-preserved burrows having menicus fillings. However, most lower Austin ichnofossils are poorly preserved and have compacted. The middle Austin Marl and upper Austin Chalk (Santonain) contain Planolites, Chondrites, Thalassinoides, and Pseudobilobites. Several thin, intensely burrowed, Fe-stained, horizons within the middle Austin represent omission surfaces having postomission Thalassinoides. The upper Austin disconformably underlies the Taylor Marl (Campanian). The Austin-Taylor contact is a Rhizocorallium-infested omission surface overlain by a condensed bed of phosphatic and pyritic bioclasts. Upper Austin occurrences of Rhizocorallium and Pseudobilobites are unique for North American Cretaceous chalks. Based on cross-cutting relationships and differences in morphology, diameter, and burrow-filling sediments, numerous ichnospecies of Thalassinoides are discernable throughout the Austin. Variations in preservation quality exhibited by successive generations of ichnofossils record progressive changes in substrate consistency. Earliest formed burrows have diffuse outlines representing an initial thixotropic (softground) Austin substrate. Subsequent generations of burrows have more distinct outlines recording a gradual increase in substrate firmness. Paleo-firmgrounds are common in Austin outcrops; evidence of hardgrounds is lacking. The Thalassinoides-dominated Austin ichnoassemblage represents an inner shelf paleoenvironment.

  9. Effective-stress-law behavior of Austin chalk rocks for deformation and fracture conductivity

    SciTech Connect

    Warpinski, N.R.; Teufel, L.W.

    1994-08-01

    Austin chalk core has been tested to determine the effective law for deformation of the matrix material and the stress-sensitive conductivity of the natural fractures. For deformation behavior, two samples provided data on the variations of the poroelastic parameter, {alpha}, for Austin chalk, giving values around 0.4. The effective-stress-law behavior of a Saratoga limestone sample was also measured for the purpose of obtaining a comparison with a somewhat more porous carbonate rock. {alpha} for this rock was found to be near 0.9. The low {alpha} for the Austin chalk suggests that stresses in the reservoir, or around the wellbore, will not change much with changes in pore pressure, as the contribution of the fluid pressure is small. Three natural fractures from the Austin chalk were tested, but two of the fractures were very tight and probably do not contribute much to production. The third sample was highly conductive and showed some stress sensitivity with a factor of three reduction in conductivity over a net stress increase of 3000 psi. Natural fractures also showed a propensity for permanent damage when net stressed exceeded about 3000 psi. This damage was irreversible and significantly affected conductivity. {alpha} was difficult to determine and most tests were inconclusive, although the results from one sample suggested that {alpha} was near unity.

  10. The Effect of Magnesium Carbonate (Chalk) on Geometric Entropy, Force, and Electromyography During Rock Climbing.

    PubMed

    Kilgas, Matthew A; Drum, Scott N; Jensen, Randall L; Phillips, Kevin C; Watts, Phillip B

    2016-12-01

    Rock climbers believe chalk dries the hands of sweat and improves the static coefficient of friction between the hands and the surface of the rock. The purpose of this study was to assess whether chalk affects geometric entropy or muscular activity during rock climbing. Nineteen experienced recreational rock climbers (13 males, 6 females; 173.5 ± 7.0 cm; 67.5 ± 3.4 kg) completed 2 climbing trails with and without chalk. The body position of the climber and muscular activity of the finger flexors was recorded throughout the trial. Following the movement sequence participants hung from a standard climbing hold until they slipped from the climbing structure, while the coefficient of friction and the ratio of the vertical forces on the hands and feet were determined. Although there were no differences in the coefficient of friction (P = .748), geometric entropy (P = .359), the ratio of the vertical forces between the hands and feet (P = .570), or muscular activity (P = .968), participants were able to hang longer after the use of chalk 62.9 ± 36.7 s and 49.3 ± 25.2 s (P = .046). This is advantageous because it may allow for prolonged rests, and more time to plan the next series of climbing moves.

  11. Variation of Cohesion and Friction Angle With Temperature In High Porosity Chalk

    NASA Astrophysics Data System (ADS)

    Madland, M. V.; Vasshus, L.; Risnes, R.

    During the last 20 years, mechanical behaviour of porous chalk has been extensively studied in order to understand the problems concerning well instability, compaction and subsidence of North Sea chalk reservoirs. At the Ekofisk field the reservoir temperature is around 1300C and any effects of such temperatures could be quite significant. The temperature effects on the mechanical properties of the reservoir rocks have however received limited attention. So far few studies have been carried out and the results point in different directions. The objective of the present project is to investigate how high temperatures affect the different mechanical parameters of chalks. The work is a part of an ongoing PhD programme. For high porosity chalks, it has been shown (Risnes et al 2000) that the Mohr circle corresponding to the Brazilian test results fits very closely to the Mohr Coulomb line derived from conventional compressive test data. This fact makes the easily performed Brazilian test useful for estimation of the chalk cohesion. Combined with uniaxial compressive tests, estimates for friction angle may also be obtained. The chalks used in this study were high porosity outcrop chalks, which have similar mechanical properties as reservoir chalks. Several series of Brazilian, uniaxial ­and triaxial compressive tests have been performed at both ambient ­and reservoir temperature. Both water and glycol was used as the saturating fluid and in addition some test series of dry samples were performed. Glycol is fully miscible with water and this property assures no capillary effects if some water should remain in the chalk before saturation Cohesion and friction angle were determined for each series at varying temperatures and the results can be summarized as follows: 1.Tests with water saturated chalk show that the cohesion decreases with around 20 % when the temperature is increased from 200C to 1300C. The friction angle seems to be less affected but increases slightly

  12. Nuclear Data Sheets for A = 64

    NASA Astrophysics Data System (ADS)

    Singh, Balraj

    1996-07-01

    Abstract:The evaluated spectroscopic data are presented for known nuclides of mass 64 (Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge). Excited-state data are nonexistent for 64Mn and 64Fe. Radioactive decay data for 64Mn are not available and those for 64Fe, 64Co and 64Ge are not considered definitive. The following nuclides have not yet been identified but, amongst other nuclides, have been included in theoretical calculations: 64Ca (92Ma60,91To03,91Hi10); 64Cr (95Re20,95Ri05,95Au04); 64As (95Au04); 64Se (93Sh11). The literature available up to June 25, 1996 has been consulted. This work supersedes earlier evaluations of A=64 published in Nuclear Data Sheets (91Si03,79Ha35,74Au04,67Ve09). Cutoff Date:Literature available up to June 25, 1996 has been consulted. General Policies and Organization of Material:See the January issue of Nuclear Data Sheets. Acknowledgments:The evaluator thanks Alfredo Galindo-Uribarri at Chalk River for discussions and communicating results of his recent in-beam experiment on 64Zn, prior to publication. General Comments:The statistical analysis of γ-ray data and deduced level schemes is carried out through computer codes available at Isotopes Project, Berkeley and Nuclear Data Center, Brookhaven. The methodology and procedures for some of these codes are described by 86BrZQ and 86Br21. A general 3% uncertainty is assumed in quoted theoretical internal conversion coefficients taken mainly from 68Ha53. The values of μ and Q are from compilation by 89Ra17, when available.

  13. Late Maastrichtian chalk mounds, Stevns Klint, Denmark — Combined physical and biogenic structures

    NASA Astrophysics Data System (ADS)

    Anderskouv, Kresten; Damholt, Tove; Surlyk, Finn

    2007-08-01

    Upper Maastrichtian chalk exposed at the Sigerslev quarry, Stevns Klint, Denmark is characterized by wavy and mound-like bedding geometries outlined by bands of black flint nodules. Four morphological elements are recognized, although bedding geometries are highly variable: southward migrating mounds, eastward migrating mounds, chalk waves and evenly bedded chalk. The mounds are interpreted as having been formed by currents carrying fine-grained suspended sediment which was primarily deposited on the up-current mound flanks. Bryozoans were prolific on the up-current flanks and mound summits, which stabilized the mounds, increased bed roughness and the overall accumulation rate. However, accumulation thicknesses do not correlate consistently with bryozoan density. The bryozoans were therefore important for the formation of the mounds, but the distribution of bryozoans did not solely determine depositional thickness across a mound and thus mound growth pattern. Relatively long wavelength wavy-bedded chalk show gentle convex-up geometries and would probably be described as sediment waves if recognized in seismic sections. The chalk waves were deposited under weaker current velocities than those active during mound formation. The exposed succession is topped by more evenly bedded chalk which was deposited by quiet pelagic fall-out of fine-grained material. The whole succession was deposited on the upper part of the northern flank of a large WNW-ESE trending 3 km wide depositional ridge with an amplitude of 35-40 m formed by contour-parallel WNW-ward flowing bottom currents. The mounds may have been deposited by regional bottom currents, or by spill-over currents from the valley south of the large ridge. The succession was deposited during varying bottom current intensities and the depositional architecture indicates a complex and dynamic environment. The depositional style seems to be controlled by the interplay and relative importance of two end-member processes

  14. Full-waveform Inversion of Crosshole GPR Data Collected in Strongly Heterogeneous Chalk: Challenges and Pitfalls

    NASA Astrophysics Data System (ADS)

    Keskinen, Johanna; Looms, Majken C.; Nielsen, Lars; Klotzsche, Anja; van der Kruk, Jan; Moreau, Julien; Stemmerik, Lars; Holliger, Klaus

    2015-04-01

    Chalk is an important reservoir rock for hydrocarbons and for groundwater resources for many major cities. Therefore, this rock type has been extensively investigated using both geological and geophysical methods. Many applications of crosshole GPR tomography rely on the ray approximation and corresponding inversions of first break traveltimes and/or maximum first-cycle amplitudes. Due to the inherent limitations associated with such approaches, the resulting models tend to be overly smooth and cannot adequately capture the small-scale heterogeneities. In contrast, the full-waveform inversion uses all the information contained in the data and is able to provide significantly improved images. Here, we apply full-waveform inversion to crosshole GPR data to image strong heterogeneity of the chalk related to changes in lithology and porosity. We have collected a crosshole tomography dataset in an old chalk quarry in Eastern Denmark. Based on core data (including plug samples and televiewer logging data) collected in our four ~15-m-deep boreholes and results from previous related studies, it is apparent that the studied chalk is strongly heterogeneous. The upper ~7 m consist of variable coarse-grained chalk layers with numerous flint nodules. The lower half of the studied section appears to be finer-grained and contains less flint. However, still significant porosity variations are also detected in the lower half. In general, the water-saturated (watertable depth ~2 m) chalk is characterized by high porosities, and thus low velocities and high attenuation, while the flint is essentially non-porous and has correspondingly high velocities and low attenuation. Together these characteristics form a strongly heterogeneous medium, which is challenging for the full-waveform inversion to recover. Here, we address the importance of (i) adequate starting models, both in terms of the dielectric permittivity and the electrical conductivity, (ii) the estimation of the source wavelet

  15. Occurrence of oil in the Austin Chalk at Van field, Van Zandt County, Texas: A unique geologic setting

    SciTech Connect

    Lowe, J.T.; Carrington, D.B. )

    1990-09-01

    The Austin Chalk is buried to a depth of only 2,100-2,500 ft and has retained primary microporosity unlike the typical deep fractured chalk reservoirs. The Van structure is a complexly faulted domal anticline created by salt intrusion and is approximately 2,000 ft higher than surrounding structures in the area. A major northwest-dipping fault acts as the primary trapping mechanism. The field has produced 0.5 billion BO from thick Woodbine sands since its discovery in 1929. Occurrence of oil in the Austin Chalk has been known since the field discovery, but prior completions were low rate oil producers. Recent development of a large fracture stimulation technique has resulted in increased production rates of up to 300 BOPD. The Austin Chalk reservoir limits were determined by isopaching feet of minimum productive resistivity having porosity above a cutoff value. The resistivity/porosity isopach showed a direct correlation between Austin Chalk productivity and the Austin Chalk structure and faulting pattern. Structural evidence along with oil typing indicate that the oil in the Austin Chalk has migrated upward along fault planes and through fault juxtaposition from the Woodbine sands 200 ft below the Austin Chalk. Thin-section and scanning electron microscopy work performed on conventional cores showed that the Van Austin Chalk formation is a very fine grained limestone composed primarily of coccoliths. Various amounts of detrital illite clay are present in the coccolith matrix. All effective porosity is micro-intergranular and ranges from 15 to 35%. Based on the core analyses, the main porosity reducing agent and therefore control on reservoir quality is the amount of detrital clay present filling the micropores. Permeability is very low with values ranging from 0.01 to 1.5 md. There is no evidence of significant natural fractures in the core. Artificial fractures are therefore required to create the permeability needed to sustain commercial production rates.

  16. The distribution and history of nuclear weapons related contamination in sediments from the Ob River, Siberia as determined by isotopic ratios of plutonium and neptunium.

    PubMed

    Kenna, T C; Sayles, F L

    2002-01-01

    Isotopic ratios of Pu and Np measured in sediment cores from 5 locations in the Ob River drainage basin show clear evidence of input from sources other than global fallout (non-fallout sources). Historical contaminant records obtained by combining isotopic ratio information with chronological information indicate that non-fallout inputs are from several sources that have varied significantly over the past 50 years. Unique isotopic signatures observed in sediments from tributaries that drain areas containing known or suspected sources of non-fallout contamination are used to identify the source of materials in sediments collected at downstream locations. These data can lead to a better understanding of the transport behavior, fate, and relative importance of particle reactive, weapons related contaminants originating from the nuclear facilities Mayak. Tomsk-7, and Semipalitinsk, which lie within the drainage basin. From our work to date, we draw the following conclusions: (1) Persistent non-fallout contamination is observed in the Ob River above its confluence with the Irtysh River, indicating contamination from the Tomsk-7 facility. (2) Non-fallout contamination in the Tobol River above its confluence with the Irtysh River indicates contamination from the Mayak facility. (3) Non-fallout contamination in the Irtysh River above its confluence with the Tobol River indicates contamination from the Semipalitinsk weapons test site. (4) The occurrence of isotopic ratios in Ob Delta sediments that are similar to those observed in source tributaries suggests that contamination from at least two sources has been transported along the length of the river system. (5) Global fallout, a result of high-yield atmospheric weapons tests conducted by the FSU and USA primarily, is the dominant source of Pu and Np to the region; however, there have been brief periods when inputs from non-fallout sources exceeded those from global fallout.

  17. Laboratory measurements of the electrokinetic and electrochemical potential in chalk, with application to monitoring of saline intrusion in the UK chalk aquifer

    NASA Astrophysics Data System (ADS)

    MacAllister, D.; Jackson, M.; Butler, A. P.; Vinogradov, J.

    2012-12-01

    Saline intrusion is a global phenomenon affecting the availability of freshwater in coastal aquifers. The aim of this work is to investigate whether measurements of spontaneous potential (SP) can be used to monitor the intrusion of seawater into coastal aquifers, with specific application to the chalk aquifer near Brighton on the south coast of the UK. SP arises to maintain electrical neutrality when a separation of charge occurs due to gradients in pressure (electrokinetic or streaming potential), concentration (electrochemical potential) and temperature (thermoelectric potential). Concentration gradients are a characteristic feature of saline intrusion and may give rise to a measureable electrochemical potential (EC). In addition the electrokinetic potential (EK) will arise during abstraction and up-coning of the saline front. The intruding saline front could therefore be detected and monitored continuously, with SP measurements in boreholes and at the surface providing dense monitoring in space and time. To determine the likely magnitude of EK and EC signals during saline intrusion into the chalk aquifer, we measured EK and EC potentials in samples of Seaford chalk saturated with (i) natural, potable groundwater from the aquifer and (ii) seawater sampled from the English Channel. The EK coupling coefficient, which relates the gradient in voltage to the gradient in water pressure when the total current is zero, was found to be -60 mV/MPa in samples saturated with groundwater. In seawater saturated samples it was found to be only -1 mV/MPa. This result agrees with earlier work suggesting the EK potential is suppressed in high salinity environments due to a compressed electrical double layer. The EK coupling coefficient was negative in both cases, suggesting that the surface charge of Seaford chalk is negative when in contact with groundwater and seawater. The electrochemical experiments involved establishing a concentration gradient across the chalk samples

  18. Discussing spent nuclear fuel in high school classrooms: addressing public fears through early education

    SciTech Connect

    Winkel, S.; Sullivan, J.; Jones, S.; Sullivan, K.; Hyland, B.; Pencer, J.; Colton, A.

    2013-07-01

    The Inreach program combines the Deep River Science Academy (DRSA) 'learning through research' approach with state of the art communication technology to bring scientific research to high school classrooms. The Inreach program follows the DRSA teaching model where a university student tutor works on a research project with scientific staff at AECL's Chalk River Laboratories. Participating high school classes are located across Canada. The high school students learn about the ongoing research activities via weekly web conferences. In order to engage the students and encourage participation in the conferences, themed exercises linked to the research project are provided to the students. The DRSA's Inreach program uses a cost-effective internet technology to reach a wide audience, in an interactive setting, without anyone leaving their desks or offices. An example Inreach research project is presented here: an investigation of the potential of the Canadian supercritical water cooled reactor (SCWR) concept to burn transuranic elements (Np, Pu, Am, Cm) to reduce the impact of used nuclear fuel. During this project a university student worked with AECL (Atomic Energy of Canada Limited) researchers on technical aspects of the project, and high school students followed their progress and learned about the composition, hazards, and disposition options for used nuclear fuel. Previous projects included the effects of tritium on cellular viability and neutron diffraction measurement of residual stresses in automobile engines.

  19. Jefferson Lab Science: Present and Future

    SciTech Connect

    McKeown, Robert D.

    2015-02-12

    The Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab comprise a unique facility for experimental nuclear physics. Furthermore, this facility is presently being upgraded, which will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics. Further in the future, it is envisioned that the Laboratory will evolve into an electron-ion colliding beam facility.

  20. 76 FR 77023 - In the Matter of Florida Power Corporation, et al., Crystal River Unit 3 Nuclear Generating Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ... co-holders of the Crystal River facility. The Crystal River facility consists of a single unit... ultimate parent corporation. As part of the transaction, Progress Energy will merge with Diamond... intermediate parent corporation of FPC. FPC is the sole operator of Crystal River. The proposed...

  1. Computer Lab Configuration.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    2003-01-01

    Describes the layout and elements of an effective school computer lab. Includes configuration, storage spaces, cabling and electrical requirements, lighting, furniture, and computer hardware and peripherals. (PKP)

  2. Computer Lab Configuration.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    2003-01-01

    Describes the layout and elements of an effective school computer lab. Includes configuration, storage spaces, cabling and electrical requirements, lighting, furniture, and computer hardware and peripherals. (PKP)

  3. Modeling Various Teaching Methods in a Faculty of Education in Science Education: Chalk and Talk, Virtual Labs or Hovercrafts

    ERIC Educational Resources Information Center

    Laronde, Gerald; MacLeod, Katarin

    2012-01-01

    This research was conducted with 291 Junior/Intermediate (J/I) pre-service teachers in a ubiquitous laptop Bachelor of Education program at Nipissing University. The authors modeled a lesson using three different teaching styles using flight as the content medium, a specific expectation found in the Ontario Ministry of Education grade six Science…

  4. Modeling Various Teaching Methods in a Faculty of Education in Science Education: Chalk and Talk, Virtual Labs or Hovercrafts

    ERIC Educational Resources Information Center

    Laronde, Gerald; MacLeod, Katarin

    2012-01-01

    This research was conducted with 291 Junior/Intermediate (J/I) pre-service teachers in a ubiquitous laptop Bachelor of Education program at Nipissing University. The authors modeled a lesson using three different teaching styles using flight as the content medium, a specific expectation found in the Ontario Ministry of Education grade six Science…

  5. An analysis of spectral differences between Nevada Test Site and Shagan River nuclear explosions

    NASA Astrophysics Data System (ADS)

    Taylor, Steven R.; Denny, Marvin D.

    1991-04-01

    Spectral ratio discrimination studies carried out on events located in the western United States and Soviet Union (S.U.) illustrate that pronounced differences in radiated explosion-source spectra relative to nearby earthquakes exist between the two regions. Nevada Test Site (NTS) explosions are characterized by the existence of more low-frequency and/or less high-frequency energy (greater low-to high-frequency spectral ratios) than western U.S. earthquakes. The opposite pattern is observed in the S.U. with nuclear explosions appearing to have more high-frequency (and/or less low-frequency) energy than earthquakes. These observations may be caused by at least two principal effects that are probably acting in parallel: (1) variations in depth-dependent effects of attenuation acting between the shallow explosions and deeper earthquakes and (2) differences in the dynamic response of the near-source geology to the passing explosion shock wave. Anelastic synthetic seismogram calculations illustrate that depth-dependent attenuation effects may explain the spectral observations. However, a number of observations using near- and far-field data from NTS explosions suggest that near-source effects are the dominant factor. A quasi-empirical explosion source model is proposed that simultaneously fits the spectral ratio data from both the U.S. and S.U. relative to earthquakes in each of the respective regions. Additionally, the model fits the trends of the spectral ratios observed as a function of magnitude. The key to the model is the shape of the pressure time history acting at the elastic radius. For explosions detonated in weak, porous rock, the radiated shock wave divides into a two-wave system consisting of an elastic precursor followed by a plastic wave. The generation of this two-wave system introduces a rise time into the pressure time history. In the frequency domain a second corner frequency is established in a third-order model (with an ω-3 high-frequency decay

  6. In-Situ Monitoring Of Nitrate Fluxes Through Unsaturated Zone In Chalk Aquifer

    NASA Astrophysics Data System (ADS)

    West, L. J.; Keim, D. M.; Odling, N. E.

    2013-12-01

    Diffuse source nitrate leaching from agricultural land threatens groundwater quality worldwide. In the United Kingdom the source of up to 70% of nitrate found in surface and groundwater is thought to have been leached from agricultural land. Rising concentrations approaching or exceeding the maximum permissible concentration level of 11.3 mg/l NO3-N (EC Drinking Water Directive) have been observed in UK catchments on the Cretaceous Chalk in recent decades. Prediction of future nitrate concentration trends in chalk aquifers is desirable for groundwater abstraction management, but is particularly challenging due to their complex dual porosity nature. Contaminants such as nitrate are either rapidly moved through the system via preferential fracture pathways or more slowly through the porous matrix. We report in-situ nitrate monitoring within the top 1 m of the soil zone and within the deeper chalk unsaturated zone at depths between 30 and 45 m carried out over an entire hydrological year. Observed nitrate concentrations exceeded natural baseline concentration of NO3-N expected in the Cretaceous Chalk aquifer of northern England by nearly four times and were nearly double the legislated maximum permissible drinking water concentration. Soil zone nitrate monitoring (up to 1 m depth) indicated a strong relationship between NO3-N concentration and land management, annual cropping and hydrological cycles. Annual variation in NO3-N concentration were smaller in water from the deeper unsaturated zone (at 30 - 45 m depth) than in the soil zone, i.e. fluctuations are smoothed by travel through the chalk unsaturated zone. However, observations in the deep unsaturated zone indicate water flow is focused in specific fractures or conduits, so contaminants from the surface will rapidly reach the water table, even through thick unsaturated zones in chalk. Moreover, the low permeability of the matrix coupled with fracture flow can result in an accumulation of NO3-N in the unsaturated

  7. Geological environment of karst within chalk using airborne time domain electromagnetic data cross-interpreted with boreholes

    NASA Astrophysics Data System (ADS)

    Reninger, P.-A.; Martelet, G.; Lasseur, E.; Beccaletto, L.; Deparis, J.; Perrin, J.; Chen, Y.

    2014-07-01

    The ability of airborne Time Domain ElectroMagnetic (TDEM) to image plurikilometric chalk heterogeneities and its implications for the development of a karstic system is addressed in this study. A heliborne TDEM survey was conducted around Courtenay (France) over the Paris Basin Upper Cretaceous chalk. This aquifer is known as a highly weathered and karstified horizon both strongly modify chalk petrophysical properties. Numerous boreholes and one recently reprocessed seismic line were used in order to strengthen TDEM interpretations. We performed cross statistics between boreholes and the resistivity model. This allowed defining empirical resistivity ranges corresponding to the main geological formations within the area. We were therefore able to map large scale heterogeneities in the chalk over the study area. First, the TDEM method highlighted probable weathering corridors in the chalk, related to the tectonic activity, consistent with faults previously interpreted in the seismics at deeper levels. Second, it was possible to image a large scale undulating geometry in the chalk with a SW-NE orientation, this direction is consistent throughout the Paris Basin, and well defined on the cliffs of Normandy (Channel coast, north of France). This geometry has revealed two separate chalk deposits C1 and C2 in Courtenay area: C1 is more resistive than C2. The resistivity model has then been compared to piezometric measurements acquired as part of previous hydrological studies. The karstic drainage appears to be developed within C1 chalk deposit and most of the piezometric domes seem to be associated to intermediate resistivity zones in C1, interpreted as weathered. According to the results obtained from this study, we were able to suggest a geological framework for the development of Courtenay karstic system.

  8. School Science Labs

    ERIC Educational Resources Information Center

    Schachter, Ron

    2008-01-01

    This article talks about the declining state of many school science laboratories. The author describes how school districts are renovating their science labs to improve student learning. The author also offers tips from those who have already renovated their school science labs.

  9. A Museum Learning Lab

    ERIC Educational Resources Information Center

    Vandiver, Kathleen M.; Bijur, Jon Markowitz; Epstein, Ari W.; Rosenthal, Beryl; Stidsen, Don

    2008-01-01

    The "Learning Lab: The Cell" exhibit was developed by the Massachusetts Institute of Technology (MIT) Museum and the MIT Center for Environmental Health Sciences (CEHS). Specially designed for middle and high school students, the Learning Lab provides museum visitors of all ages with fascinating insights into how our living cells work. The…

  10. PRIME Lab Radiocarbon Measurements

    NASA Astrophysics Data System (ADS)

    Hillegonds, D. J.; Mueller, K. A.; Ma, X.; Lipschutz, M. E.

    1996-03-01

    The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is one of three NSF national facilities for accelerator mass spectrometry (AMS), and is the only one capable of determining six cosmogenic radionuclides: 10Be, 14C, 26Al, 36Cl, 41Ca, and 129I. This abstract describes the current status of the radiocarbon analysis program at PRIME Lab.

  11. Lab Report Blues

    ERIC Educational Resources Information Center

    Diaz, Andrew

    2004-01-01

    For middle school students, writing a formal lab report can be challenging. For middle level teachers, reading students lab reports can be overwhelming. After grading report after report with incomplete procedures, incorrect graphs, and missing conclusions, the author's frustration level was at an all-time high. Ready to try anything, he thought,…

  12. LabSkills

    ERIC Educational Resources Information Center

    O'Brien, Nick

    2010-01-01

    This article describes LabSkills, a revolutionary teaching tool to improve practical science in schools. LabSkills offers the chance to help improve the exposure that the average Key Stage 5 (age 16-19) student has to practical work. This is a huge area for development being highlighted by universities who are seeing a worryingly growing trend in…

  13. LabSkills

    ERIC Educational Resources Information Center

    O'Brien, Nick

    2010-01-01

    This article describes LabSkills, a revolutionary teaching tool to improve practical science in schools. LabSkills offers the chance to help improve the exposure that the average Key Stage 5 (age 16-19) student has to practical work. This is a huge area for development being highlighted by universities who are seeing a worryingly growing trend in…

  14. Making Real Virtual Labs

    ERIC Educational Resources Information Center

    Keller, Harry E.; Keller, Edward E.

    2005-01-01

    Francis Bacon began defining scientific methodology in the early 17th century, and secondary school science classes began to implement science labs in the mid-19th century. By the early 20th century, leading educators were suggesting that science labs be used to develop scientific thinking habits in young students, and at the beginning of the 21st…

  15. Physics Labs with Flavor

    ERIC Educational Resources Information Center

    Agrest, Mikhail M.

    2009-01-01

    This paper describes my attempts to look deeper into the so-called "shoot for your grade" labs, started in the '90s, when I began applying my teaching experience in Russia to introductory physics labs at the College of Charleston and other higher education institutions in South Carolina. The term "shoot for your grade" became popular among…

  16. A Museum Learning Lab

    ERIC Educational Resources Information Center

    Vandiver, Kathleen M.; Bijur, Jon Markowitz; Epstein, Ari W.; Rosenthal, Beryl; Stidsen, Don

    2008-01-01

    The "Learning Lab: The Cell" exhibit was developed by the Massachusetts Institute of Technology (MIT) Museum and the MIT Center for Environmental Health Sciences (CEHS). Specially designed for middle and high school students, the Learning Lab provides museum visitors of all ages with fascinating insights into how our living cells work. The…

  17. School Science Labs

    ERIC Educational Resources Information Center

    Schachter, Ron

    2008-01-01

    This article talks about the declining state of many school science laboratories. The author describes how school districts are renovating their science labs to improve student learning. The author also offers tips from those who have already renovated their school science labs.

  18. NOT Another Lab Report

    ERIC Educational Resources Information Center

    Ende, Fred

    2012-01-01

    Ask students to name the aspects of science class they enjoy most, and working on labs will undoubtedly be mentioned. What often won't be included, however, is writing lab reports. For many students, the process of exploration and data collection is paramount, while the explanation and analysis of findings often takes a backseat. After all, if…

  19. Lab Report Blues

    ERIC Educational Resources Information Center

    Diaz, Andrew

    2004-01-01

    For middle school students, writing a formal lab report can be challenging. For middle level teachers, reading students lab reports can be overwhelming. After grading report after report with incomplete procedures, incorrect graphs, and missing conclusions, the author's frustration level was at an all-time high. Ready to try anything, he thought,…

  20. NOT Another Lab Report

    ERIC Educational Resources Information Center

    Ende, Fred

    2012-01-01

    Ask students to name the aspects of science class they enjoy most, and working on labs will undoubtedly be mentioned. What often won't be included, however, is writing lab reports. For many students, the process of exploration and data collection is paramount, while the explanation and analysis of findings often takes a backseat. After all, if…

  1. Physics Labs with Flavor

    ERIC Educational Resources Information Center

    Agrest, Mikhail M.

    2009-01-01

    This paper describes my attempts to look deeper into the so-called "shoot for your grade" labs, started in the '90s, when I began applying my teaching experience in Russia to introductory physics labs at the College of Charleston and other higher education institutions in South Carolina. The term "shoot for your grade" became popular among…

  2. A Perspective on Coupled Multiscale Simulation and Validation in Nuclear Materials

    SciTech Connect

    M. P. Short; D. Gaston; C. R. Stanek; S. Yip

    2014-01-01

    The field of nuclear materials encompasses numerous opportunities to address and ultimately solve longstanding industrial problems by improving the fundamental understanding of materials through the integration of experiments with multiscale modeling and high-performance simulation. A particularly noteworthy example is an ongoing study of axial power distortions in a nuclear reactor induced by corrosion deposits, known as CRUD (Chalk River unidentified deposits). We describe how progress is being made toward achieving scientific advances and technological solutions on two fronts. Specifically, the study of thermal conductivity of CRUD phases has augmented missing data as well as revealed new mechanisms. Additionally, the development of a multiscale simulation framework shows potential for the validation of a new capability to predict the power distribution of a reactor, in effect direct evidence of technological impact. The material- and system-level challenges identified in the study of CRUD are similar to other well-known vexing problems in nuclear materials, such as irradiation accelerated corrosion, stress corrosion cracking, and void swelling; they all involve connecting materials science fundamentals at the atomistic- and mesoscales to technology challenges at the macroscale.

  3. [Accumulation of radionuclides in food chains of the Yenisei River after the nuclear power plant shutdown at the mining-and-chemical enterprise].

    PubMed

    Zotina, T A; Trofimova, E A; Karpov, A D; Bolsunovskiĭ, A Ia

    2014-01-01

    Accumulation of artificial and natural radionuclides in the chains of food webs leading to non-predatory and piscivorous fish of the Yenisei River was investigated during one year before and three years after the shutdown of a nuclear power plant at the Mining-and-Chemical Combine (2009-2012). The activity of artificial radionuclides in the samples of biota ofthe Yenisei River (aquatic moss, gammarids, dace, grayling, pike) was estimated. The concentration of radionuclides with induced activity (51Cr, 54Mn, 58Co, 60Co, 65Zn, 141, 144Ce, 152, 154Eu, 239Np) decreased in the biomass of biota after the shutdown of the nuclear power plant; the concentration of 137Cs did not. Analysis of the accumulation factors (C(F)) allows us to expect the effective accumulation of 137Cs in the terminal level of the food web of the Yenisei River--pike (C(F) = 2.0-9.4), i.e. biomagnifications of radiocesium. Accumulation of artificial, radionuclides in non-predatory fish from gammarids was not effective (C(F) < 1). An effective accumulation of 40K is possible in muscles of non-predatory and piscivorous fish species from food (C(F) = 2:6-3.1 and 1.3-1.4, respectively). C(Fs) of K and 40K were equal in all trophic pairs, but C(Fs) of 40K and 137Cs differed considerably.

  4. Results of blue crab studies at Chalk Point. Final report 1978-1979

    SciTech Connect

    Souza, P.A.; Polgar, T.T.; Miller, R.E.; Holland, A.F.

    1980-11-01

    This report summarizes the findings of two years of blue crab tagging studies conducted in the Patuxent estuary near the Chalk Point power plant. This report is organized in the following manner: An introduction and objectives section defines the objectives of the blue crab study, discusses the modes of interaction between blue crabs and power plant operations, and discusses the life history characteristics of blue crabs. A study methods section provides detailed information on tagging and capture operations and on analysis methods. A results section presents the major findings of the study. A discussion and conclusions section interprets and discusses major findings and defines the impacts of power plant operations at Chalk Point on blue crab populations in the Patuxent estuary. A list of references is included.

  5. Evaluation of auxiliary tempering pump effectiveness at Chalk Point Steam Electric Station

    SciTech Connect

    Wendling, L.C.; Holland, A.F.

    1989-08-01

    The effectiveness of auxiliary tempering pump operation at Chalk Point Steam Electric Station (SES) at reducing plant-induced mortality of aquatic biota was evaluated. Several Representative Important Species (RIS) and dominant benthic and zooplankton species were used in the evaluation as indicators of overall system-wide responses. Expected mortality with and without auxiliary pump operation was estimated using thermal tolerance data available from the scientific literature for blue crabs, white perch, striped bass, spot, Macoma balthica and Acartia tonsa. The evaluation led to the conclusion that the operation of auxiliary tempering pumps at Chalk Point SES increases plant-induced mortality of spot, white perch, striped bass, and zooplankton. Operation of the tempering pumps may reduce blue crab mortality slightly under certain circumstances, and Macoma balthica mortality is probably largely unaffected by their operation.

  6. Bringing mini-chalk talks to the bedside to enhance clinical teaching.

    PubMed

    Pitt, Michael B; Orlander, Jay D

    2017-01-01

    Chalk talks - where the teacher is equipped solely with a writing utensil and a writing surface - have been used for centuries, yet little has been written about strategies for their use in medical education. Structured education proximal to patient encounters (during rounds, at the bedside, or in between patients in clinic) maximizes the opportunities for clinical learning. This paper presents a strategy to bring mini-chalk talks (MCTs) to the bedside as a practical way to provide relevant clinical teaching by visually framing teachable moments. Grounded in adult learning theory, MCTs leverage teaching scripts to facilitate discussion, involve learners at multiple levels, and embrace the increased retention associated with visual aids. These authors provide specific recommendations for the design and implementation of MCT sessions including what topics work well, how to prepare, and how to involve and engage the learners.

  7. NMR response of non-reservoir fluids in sandstone and chalk.

    PubMed

    van der Zwaag, C H; Stallmach, F; Skjetne, T; Veliyulin, E

    2001-01-01

    Transverse (T2) NMR relaxation time at 2 MHz proton resonance frequency was measured on core plug samples from two different lithologies, sandstone and chalk, before and after exposure to selected drilling fluids. The results show that NMR signal response was significantly altered after displacing 50% of the original pore fluids, crude oil and water, by drilling fluid filtrate. Relaxation spectra of the rock samples invaded by water-based filtrate shift to significantly shorter T2-values. This shift yields an underestimation of the free-fluid volumes when selecting cut-off values of 33 ms and 100 ms for sandstone and chalk, respectively. In opposite, rock samples affected by oil-based filtrate respond with a signal indicating significantly larger free-fluid volumes than present before exposure. NMR-permeability calculated based on the Timur-Coates Free Fluid model altered in some cases by one order of magnitude.

  8. A model for flow in the chalk unsaturated zone incorporating progressive weathering

    NASA Astrophysics Data System (ADS)

    Ireson, A. M.; Mathias, S. A.; Wheater, H. S.; Butler, A. P.; Finch, J.

    2009-02-01

    SummaryGroundwater from unconfined chalk aquifers constitutes a major water resource in the UK. The unsaturated zone in such systems plays a crucial role in the hydrological cycle, determining the timing and magnitude of recharge, and the transport and fate of nutrients. However, despite more than three decades of study, our physical understanding of this system is incomplete. In this research, state of the art instrumentation provided high temporal resolution readings of soil moisture status, rainfall and actual evaporation from two sites in the Pang and Lambourn catchments (Berkshire, UK), for a continuous two year period (2004/5). A parsimonious, physically based model for the flow of water through the chalk unsaturated zone, including a novel representation of the soil and weathered chalk layers, was developed. The parameters were identified by inverse modelling using field measurements of water content and matric potential. The model was driven by rainfall and evaporation data, and simulated fluxes throughout the profile (including the discrete matrix and fracture components), down to the water table (but not the water table response). Results showed that the model was able to reproduce closely the observed changes in soil moisture status. Recharge was predominantly through the matrix, and the recharge response was strongly attenuated with depth. However, the activation of fast recharge pathways through fractures in the chalk unsaturated zone was highly sensitive to rainfall intensity. Relatively modest increases in rainfall led to dramatically different recharge patterns, with potentially important implications for groundwater flooding. The development and migration of zero flux planes with time and depth were simulated. The simulations also provided strong evidence that, for water table depths greater than 5 m, recharge fluxes persist throughout the entire year, even during drought conditions, with important implications for the calculation of specific yield

  9. Full-waveform inversion of Crosshole GPR data: Implications for porosity estimation in chalk

    NASA Astrophysics Data System (ADS)

    Keskinen, Johanna; Klotzsche, Anja; Looms, Majken C.; Moreau, Julien; van der Kruk, Jan; Holliger, Klaus; Stemmerik, Lars; Nielsen, Lars

    2017-05-01

    The Maastrichtian-Danian chalk is a widely distributed hydrocarbon and groundwater reservoir rock in north-western Europe. Knowledge of lateral and vertical heterogeneity and porosity variation in this type of rock is essential, since they critically determine the reservoir properties. We have collected a densely sampled crosshole ground-penetrating radar (GPR) dataset from a highly heterogeneous section of the chalk and inverted it with a full-waveform inversion (FWI) approach. To date, successful crosshole FWI has only been reported for a handful of GPR field data, none of which include strongly heterogeneous environments like the one considered in this study. Testing different starting models shows that all FWI results converge to very similar subsurface structures indicating that the results are robust with regard to local variations in the permittivity starting models and are not very sensitive to the conductivity starting models. Compared to their ray-based counterparts, the obtained FWI models show significantly higher resolution and improved localization of fine-scale heterogeneity. The final FWI permittivity tomogram was converted to a bulk porosity model using the Complex Refractive Index Model (CRIM) and comparisons with plug sample porosities and televiewer image logs verify that variations in the obtained permittivity are related to facies and lithology changes. The inferred porosity varies from 30 to 54%, which is consistent with values in the chalk cores from the investigated boreholes and in agreement with other studies conducted in similar rocks onshore. Moreover, porosities vary significantly over scales of less than a meter both laterally and vertically. The FWI constrains porosity variation with decimeter scale resolution in our 5 m (horizontally) by 10 m (vertically) model section bridging the gap between what is measured on the core sample scale and the scale typical of hydrogeophysical field experiments conducted to characterize fluid flow in

  10. Waveform analysis of crosshole GPR data collected in heterogeneous chalk deposits

    NASA Astrophysics Data System (ADS)

    Keskinen, Johanna; Nielsen, Lars; Looms, Majken C.; Moreau, Julien; Stemmerik, Lars; Klotzsche, Anja; van der Kruk, Jan; Holliger, Klaus

    2014-05-01

    Chalks are important reservoirs for groundwater production onshore Denmark and for hydrocarbons in the North Sea Basin. Therefore this rock type is studied extensively with geological and geophysical methods. Ground-penetrating radar (GPR) tomography is used to characterize fine-scale reservoir properties, e.g. subtle changes in porosity. We have conducted a range of high-resolution GPR crosshole experiments in Boesdal quarry in Eastern Denmark. The objective is to investigate the impact of fine-scale heterogeneity on reservoir properties in chalk. The studied chalk interval is c.15 m thick. It can be divided into two main units based on the traveltime analysis and interpretation of the cored material from the boreholes. The lower unit consists mainly of porous calcareous mudstone with occasional occurrences of flint nodules. The upper succession is c. 8 m thick and is fairly heterogeneous with multiple beds of wackestones and packstones with abundant flint nodules or bands. The heterogeneity of the upper layer is expressed by more complex waveforms than the lower unit. Pronounced attenuation of the transmitted wave fields is observed in the highly porous lower unit. Full-waveform inversion methods are highly dependent on the quality of the starting models (usually obtained from ray-based tomography), as well as on the assumptions made regarding the source signal. Adequate estimation of starting models and source waveform is, however, a challenging task for the strongly heterogeneous chalk material. We highlight the critical aspects regarding these tasks for the two contrasting layers. Furthermore we demonstrate how different starting models and assumptions regarding the source signal estimation affect the waveform inversion results.

  11. Development and maintenance of a telescoping debris flow fan in response to human-induced fan surface channelization, Chalk Creek Valley Natural Debris Flow Laboratory, Colorado, USA

    NASA Astrophysics Data System (ADS)

    Wasklewicz, T.; Scheinert, C.

    2016-01-01

    Channel change has been a constant theme throughout William L. Graf's research career. Graf's work has examined channel changes in the context of natural environmental fluctuations, but more often has focused on quantifying channel change in the context of anthropogenic modifications. Here, we consider how channelization of a debris flows along a bajada has perpetuated and sustained the development of 'telescoping' alluvial fan. Two-dimensional debris-flow modeling shows the importance of the deeply entrenched channelized flow in the development of a telescoping alluvial fan. GIS analyses of repeat (five different debris flows), high-resolution (5 cm) digital elevation models (DEMs) generated from repeat terrestrial laser scanning (TLS) data elucidate sediment and topographic dynamics of the new telescoping portion of the alluvial fan (the embryonic fan). Flow constriction from channelization helps to perpetuate debris-flow runout and to maintain the embryonic fan and telescoping nature of the alluvial fan complex. Embryonic fan development, in response to five debris flows, proceeds with a major portion of the flows depositing on the southern portion of the embryonic fan. The third through the fifth debris flows also begin to shift some deposition to the northern portion of the embryonic. The transfer of sediment from a higher portion of the embryonic fan to a lower portion continues currently on the embryonic fan. While channelized flow has been shown to be critical to the maintenance of the telescoping fan, the flow constriction has led to higher than background levels of sediment deposition in Chalk Creek, a tributary of the Arkansas River. A majority of the sediment from each debris flow is incorporated into Chalk Creek as opposed to being stored on the embryonic fan.

  12. Fracture-network 3D characterization in a deformed chalk reservoir analogue -- the Laegerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1995-09-01

    Quantitative descriptions of 3D fracture networks in terms of fracture characteristics and connectivity are necessary for reservoir evaluation, management, and EOR programs of fractured reservoirs. The author`s research has focused on an analogue to North Sea fractured chalk reservoirs that is excellently exposed near Laegerdorf, northwest Germany. An underlying salt diapir uplifted and deformed Upper Cretaceous chalk; the cement industry now exploits it. The fracture network in the production wall of the quarry was characterized and mapped at different scales, and 12 profiles of the 230-m wide and 35-m high production wall were investigated as the wall receded 25 m. In addition, three wells were drilled into the chalk volume. The wells were cored and the wellbores were imaged with both the resistivity formation micro scanner (FMS) and the sonic circumferential borehole image logger (CBIL). The large amount of fracture data was analyzed with respect to parameters, such as fracture density distribution, orientation, and length distribution, and in terms of the representativity and predictability of data sets collected from restricted rock volumes.

  13. Chemostratigraphy of Upper Cretaceous chalk sequences in Norwegian-Danish basin and North Sea Central Trough

    SciTech Connect

    Joergensen, N.O.

    1987-05-01

    Geochemical studies of subsurface sections and outcrops in the Upper Cretaceous chalk sequences from the Norwegian-Danish basin and the North Sea Central Trough have resulted in a detailed chemostratigraphy for these strata. The most applicable chemostratigraphic markers are based on the distribution of strontium, magnesium, manganese, the /sup 13/C//sup 12/C ratio, and the variations in the carbonate contents. It is demonstrated that the chemostratigraphic approach is valid at two levels: (1) a superior chemostratigraphy in which deep-sea cores from the Atlantic Ocean and sections from western Europe are correlated on the basis of significant geochemical anomalies and long-term variations most likely induced by oceanic geochemical cycles and sea level fluctuations; (2) a subordinate but detailed intrabasinal chemostratigraphic correlation which primarily reflects the physicochemical conditions in the depositional environment. The Upper Cretaceous chemostratigraphy established in the Danish area allows a detailed correlation between relatively continuous chalk sequences in the Norwegian-Danish basin and the rather condensed and hiati-influenced sections in the oil fields of the North Sea. The results emphasize the applicability of chemostratigraphy in the subsurface exploration for hydrocarbon reservoirs in chalk.

  14. Late Cretaceous (late Campanian-Maastrichtian) sea-surface temperature record of the Boreal Chalk Sea

    NASA Astrophysics Data System (ADS)

    Thibault, Nicolas; Harlou, Rikke; Schovsbo, Niels H.; Stemmerik, Lars; Surlyk, Finn

    2016-02-01

    The last 8 Myr of the Cretaceous greenhouse interval were characterized by a progressive global cooling with superimposed cool/warm fluctuations. The mechanisms responsible for these climatic fluctuations remain a source of debate that can only be resolved through multi-disciplinary studies and better time constraints. For the first time, we present a record of very high-resolution (ca. 4.5 kyr) sea-surface temperature (SST) changes from the Boreal epicontinental Chalk Sea (Stevns-1 core, Denmark), tied to an astronomical timescale of the late Campanian-Maastrichtian (74 to 66 Ma). Well-preserved bulk stable isotope trends and calcareous nannofossil palaeoecological patterns from the fully cored Stevns-1 borehole show marked changes in SSTs. These variations correlate with deep-water records of climate change from the tropical South Atlantic and Pacific oceans but differ greatly from the climate variations of the North Atlantic. We demonstrate that the onset and end of the early Maastrichtian cooling and of the large negative Campanian-Maastrichtian boundary carbon isotope excursion are coincident in the Chalk Sea. The direct link between SSTs and δ13C variations in the Chalk Sea reassesses long-term glacio-eustasy as the potential driver of carbon isotope and climatic variations in the Maastrichtian.

  15. Late Cretaceous (Late Campanian-Maastrichtian) sea surface temperature record of the Boreal Chalk Sea

    NASA Astrophysics Data System (ADS)

    Thibault, N.; Harlou, R.; Schovsbo, N. H.; Stemmerik, L.; Surlyk, F.

    2015-11-01

    The last 8 Myr of the Cretaceous greenhouse interval were characterized by a progressive global cooling with superimposed cool/warm fluctuations. The mechanisms responsible for these climatic fluctuations remain a source of debate that can only be resolved through multi-disciplinary studies and better time constraints. For the first time, we present a record of very high-resolution (ca. 4.5 kyr) sea-surface temperature (SST) changes from the Boreal epicontinental Chalk Sea (Stevns-1 core, Denmark), tied to an astronomical time scale of the late Campanian-Maastrichtian (74 to 66 Myr). Well-preserved bulk stable isotope trends and calcareous nannofossil palaeoecological patterns from the fully cored Stevns-1 borehole show marked changes in SSTs. These variations correlate with deep-water records of climate change from the tropical South Atlantic and Pacific oceans but differ greatly from the climate variations of the North Atlantic. We demonstrate that the onset and end of the early Maastrichtian cooling and of the large negative Campanian-Maastrichtian boundary carbon isotope excursion are coincident in the Chalk Sea. The direct link between SSTs and δ13C variations in the Chalk Sea reassesses long-term glacio-eustasy as the potential driver of carbon isotope and climatic variations in the Maastrichtian.

  16. Horizontal exploitation of the Upper Cretaceous Austin Chalk of south Texas

    SciTech Connect

    Borkowski, R.; Hand, L.; Dickerson, D.; Bird, S. )

    1990-05-01

    Horizontal drilling in the fractured Austin Chalk of south Texas has proven to be a viable technology for exploiting reserve opportunities in mature trends as well as in frontier areas. To date, the results of an interdisciplinary approach to the regional analysis of structure and stress regimes combined with studies of the depositional characteristics of the Austin Chalk and Eagleford Shale have been a success. Productive characteristics of the Austin Chalk indicate the influence of regional fractures on the preferential flow direction and partitioning in the Pearsall field area of the trend. Well bore orientation and inclination are designed such that multiple fracture swarms at several stratigraphic horizons are intersected with a single horizontal well bore. As a result of the greater frequency of fracture contacts with the well bore, there is a significant increase in the ultimate recovery of hydrocarbons in place. Conventional vertical drilling techniques are frequently ineffective at encountering these laterally partitioned fracture sets, resulting in lower volumes of recoverable hydrocarbons. Additionally, horizontal well bores may increase ultimate recovery of hydrocarbons by lowering the pressure gradient to the well bore and maximizing the reservoir energy.

  17. Movement of leachate from beneath turkey litter sited over chalk in southern England.

    PubMed

    Gooddy, Daren C

    2002-01-01

    Farm waste stores are widespread in the UK, with many overlying the principal aquifer, the Chalk. The stores pose a threat to groundwater quality through the infiltration of high concentrations of nitrogen species and organic carbon together with pathogenic microbes. Two cored boreholes have been drilled into the unsaturated chalk to depths of 15 and 20 metres, respectively, through a site which has been used to store turkey litter for in excess of 20 years. Porewaters were extracted from the cores and analysed for a range of chemical elements. In addition, chalk core material was also taken for microbial examination. Both boreholes showed very high concentrations of nitrate-N (3000 mg/L), ammonia (5000 mg/L), organic carbon (3000 mg/L), and potassium (10,000 mg/L) in the top 5 metres of the profile. Below this depth concentrations declined dramatically. Highest concentrations were found in the borehole constructed in the middle of the site. The borehole constructed at the edge of the store showed much lower concentrations but did show a peak of nitrate around 10 metres below ground level. The apparent lack of movement beneath the centre of the store suggests the turkey litter is relatively impermeable and most leaching occurs where the covering of litter is thin or when the litter is annually cleared. If the leachate continues to migrate at this apparent rate, it will take more than 100 years to reach the water table.

  18. Persistent and emerging micro-organic contaminants in Chalk groundwater of England and France.

    PubMed

    Lapworth, D J; Baran, N; Stuart, M E; Manamsa, K; Talbot, J

    2015-08-01

    The Chalk aquifer of Northern Europe is an internationally important source of drinking water and sustains baseflow for surface water ecosystems. The areal distribution of microorganic (MO) contaminants, particularly non-regulated emerging MOs, in this aquifer is poorly understood. This study presents results from a reconnaissance survey of MOs in Chalk groundwater, including pharmaceuticals, personal care products and pesticides and their transformation products, conducted across the major Chalk aquifers of England and France. Data from a total of 345 sites collected during 2011 were included in this study to provide a representative baseline assessment of MO occurrence in groundwater. A suite of 42 MOs were analysed for at each site including industrial compounds (n=16), pesticides (n=14) and pharmaceuticals, personal care and lifestyle products (n=12). Occurrence data is evaluated in relation to land use, aquifer exposure, well depth and depth to groundwater to provide an understanding of vulnerable groundwater settings. Copyright © 2015 Natural Environment Research Council. Published by Elsevier Ltd.. All rights reserved.

  19. Oxidation and dispersion of HT in the environment: the August 1986 field experiment at Chalk River.

    PubMed

    Brown, R M; Ogram, G L; Spencer, F S

    1990-02-01

    The short-range environmental dispersion and oxidation of a release of tritiated hydrogen (HT) to the atmosphere has been studied in a field experiment. Emphasis was placed on the processes leading to the appearance of tritiated water (HTO) vapor in the atmosphere because HTO is much more radiotoxic than HT. The following conclusions were reached: No evidence was found for the rapid conversion of HT to HTO in the atmosphere; HTO observed in air, during and after the release, arose mainly from HT oxidation in the soil followed by emission of HTO; HT deposition velocities to soil ranged from 0.041 cm s-1 to 0.13 cm s-1, consistent with previous chamber measurements; the rate of HTO loss from soil, averaged over 21 d, was less than 1% h-1; and HTO concentrations in vegetation water initially increased with time after the release, then by 48 h decreased exponentially at a rate similar to soils.

  20. Virtual labs: a substitute for traditional labs?

    PubMed

    Scheckler, Rebecca K

    2003-01-01

    Current technologies give us the ability to enhance and replace developmental biology classes with computer-based resources, often called virtual labs. In the process of using these resources, teachers may be tempted to neglect the simpler technologies and lab bench activities, which can be labor intensive. In this paper, I take a critical look at the role of computer-based materials for the teaching of developmental biology in order to aid teachers in assessing their value. I conclude that while digital tools have value, they should not replace all of the traditional laboratory activities. Clearly, both computer-enhanced activities and traditional labs must be included in laboratory exercises. Reliance on only one or the other is inappropriate. In order to determine when it is appropriate to use a particular educational tool, the goals of the course and the needs of biology students for an education that gives them a realistic and engaged view of biology must be understood. In this paper, I dispel some of the myths of computer tools and give specific guidelines for assessing their usage, taking into account the special needs of a developmental biology class and the difficulties of observing all the developmental stages of subject organisms in the timescale of class meetings.

  1. Remote monitoring of the Gravelly Run thermal plume at Hopewell and the thermal plume at the Surry Nuclear Power Plant on the James River

    NASA Technical Reports Server (NTRS)

    Talay, T. A.; Sykes, K. W.; Kuo, C. Y.

    1979-01-01

    On May 17, 1977, a remote sensing experiment was conducted on the James River, Virginia, whereby thermal spectrometer and near-infrared photography data of thermal discharges at Hopewell and the Surry nuclear power plant were obtained by an aircraft for one tidal cycle. These data were used in subsequent investigations into the near field discharge trajectories. For the Gravelly Run thermal plume at Hopewell, several empirical expressions for the plume centerline were evaluated by comparisons of the computed trajectories and those observed in the remote sensing images.

  2. The influence of ionic forces on the effective diffusion coefficient in fractured, porous chalk.

    NASA Astrophysics Data System (ADS)

    Kremer, K.; Reichert, B.

    2005-12-01

    Solute transport in fractured, highly porous chalk significantly depends on the diffusive mass transfer of substances between the mobile water in the fracture and the immobile water of the rock matrix. Matrix diffusion is an important transport mechanism and a central factor for the retardation of solutes. Until now, simple estimation methods for the diffusive behavior of substances such as Archie's law can only be applied to single substances. Multi-tracer experiments proved a mutual influence on the diffusion of ionic solutes thus leading to significant deviations in respect to the theoretically estimated effective diffusion coefficient D_e. An increase of ionic forces in the aqueous phase is often accompanied by a decrease of D_e for cations and an increase for anions. However, groundwater contamination usually consists of several pollutants in different mixtures. Besides ionic forces, effects of channeling and transport of colloids can result in incorrectly estimated D_e values and, hence, high inaccuracy in the modeling of contaminant transport in fractured porous media. In the context of a current DFG-project, the impact of ionic forces on D_e as well as the interaction of the diffusion of ionic ground water solutes in fractured chalk of Denmark (Cretaceous, Sigerslev) and Israel (Eocene, Negev desert) will be quantified to develop a procedure for an improved estimation of D_e in dependence of the ionic activity. Consequently, the well established Archie's law for the prediction of diffusivities on the basis of the total porosities will be modified by an extension term a. So far series of single-tracer through-diffusion experiments have been performed with potassium bromide in six different concentrations to quantify the concentration dependence on the matrix diffusion as well as to examine the influence of the ionic strength on the effective diffusion coefficients of ionic solutes. The simultaneously injected neutral deuterium serves as a reference tracer

  3. Jefferson Lab Virtual Tour

    ScienceCinema

    None

    2016-07-12

    Take a virtual tour of the campus of Thomas Jefferson National Accelerator Facility. You can see inside our two accelerators, three experimental areas, accelerator component fabrication and testing areas, high-performance computing areas and laser labs.

  4. Deciphering Your Lab Report

    MedlinePlus

    ... in a sample as with a cholesterol level ( quantitative ). Other reports may simply give a positive or ... responsible person was notified. Units of measurement (for quantitative results). The units of measurement that labs use ...

  5. Jefferson Lab Virtual Tour

    SciTech Connect

    2013-07-13

    Take a virtual tour of the campus of Thomas Jefferson National Accelerator Facility. You can see inside our two accelerators, three experimental areas, accelerator component fabrication and testing areas, high-performance computing areas and laser labs.

  6. Advanced Lab Consortium ``Conspiracy''

    NASA Astrophysics Data System (ADS)

    Reichert, Jonathan F.

    2006-03-01

    Advanced Laboratory instruction is a time-honored and essential element of an undergraduate physics education. But, from my vantage point, it has been neglected by the two major professional societies, APS and AAPT. At some schools, it has been replaced by ``research experiences,'' but I contend that very few of these experiences in the research lab, particularly in the junior year, deliver what they promise. It is time to focus the attention of APS, AAPT, and the NSF on the advanced lab. We need to create an Advanced Lab Consortium (ALC) of faculty and staff to share experiments, suppliers, materials, pedagogy, ideas, in short to build a professional network for those committed to advanced lab instruction. The AAPT is currently in serious discussions on this topic and my company stands ready with both financial and personnel resources to support the effort. This talk is a plea for co-conspirators.

  7. GeneLab

    NASA Technical Reports Server (NTRS)

    Berrios, Daniel C.; Thompson, Terri G.

    2015-01-01

    NASA GeneLab is expected to capture and distribute omics data and experimental and process conditions most relevant to research community in their statistical and theoretical analysis of NASAs omics data.

  8. Diagenesis of the Machar Field (British North Sea) chalk: Evidence for decoupling of diagenesis in fractures and the host rock

    SciTech Connect

    Maliva, R.G.; Dickson, J.A.D.; Smalley, P.C.; Oxtoby, N.H.

    1995-01-02

    The Chalk Group (Cretaceous/Tertiary) in the Machar Field (British North Sea) contains both fracture-filling and microcrystalline calcite cements. Modeling of fluid-rock interaction using data on light stable isotopes obtained by whole rock analyses and laser ablation analyses of calcite cements reveal that the fracture and matrix diagenetic systems were largely decoupled. The calcium and carbonate of the fracture-filling calcite cements were derived largely from the adjacent chalk matrix. The fracture diagenetic system had a high water-rock ratio, which maintained a relatively stable water {delta}{sup 18}O ratio during calcite dissolution and precipitation. The chalk matrix, on the contrary, had a low molar water-rock ratio during recrystallization, which resulted in increases in the pore-water {delta}{sup 18}O value during recrystallization at elevated temperatures. This evolution of the pore-water {delta}{sup 18}O value is manifested by highly variable cement {delta}{sup 18}O values. The present-day formation waters of the Machar Field have {sup 87}Sr/{sup 86}Sr ratios significantly higher than the whole rock and fracture-filling cement calcite values, evidence that the chemical composition of the formation waters is not representative of that of the pore waters during chalk recrystallization. Little diagenesis is therefore now occurring in the Machar Field. The diagenetic systems of the chalk matrix and fractures both had a high degree of openness with respect to carbon, because of the introduction of organically derived bicarbonate rather than advection of water through the chalk. The bulk of calcite cementation in fractures and the recrystallization and cementation of the chalk matrix occurred at temperatures in the 80--100 C range, at or just below the present-day reservoir temperature of 97 C.

  9. Nonproliferation through international lab-to-lab technology cooperation

    SciTech Connect

    Dunlop, W H

    1998-09-10

    At the Lawrence Livermore National Laboratory (LLNL) one of the fastest growing programs as a result of the end of the Cold War is the Nonproliferation, Arms Control, and International Security Directorate (NAI). Since the early 1990's NAI types of programs have grown from a small percentage of LLNL's budget to constitute one of its major programs. NAI's work includes developing instruments to detect chemicals and radiation, analyzing complex national defense problems, anticipating threats to the US, and providing personnel to support national and international efforts in crisis management and arms control. These functions support the US government in dealing with weapons-of-mass-destruction challenges- proliferation, terrorism, and nuclear-state instability. To combat the rapidly emerging chem-bio-terrorism threats, NAI is drawing on LLNL's advanced technologies in bioscience, microfabrication, and computations to help the Department of Energy (DOE )provide major support to the US government. Half of NAI's effort is directed toward preventing proliferation before it starts, which is the mission of the Proliferation Prevention and Arms Control Program (PPAC). Until recently, our emphasis was on arms control. Now, arms control continues to be an important component while international cooperation and fissile material control are our dominant activities for the Department of Energy. Many of the post-Cold-War changes are highly visible, such as the elimination of nuclear testing by the United States, Russia, China and other major powers; agreements and continuing negotiations to dramatically reduce numbers of nuclear weapons; and increasing international focus on nonproliferation and counterterrorism. Other changes are less highly publicized but are no less significant. One such area is the increasing interactions between DOE Laboratory scientists and their counterparts in the nuclear weapons institutes of the former Soviet Union. Although the large majority of these

  10. Z Machine at Sandia Labs

    SciTech Connect

    2007-10-17

    Sandia Labs' Z machine is the largest laboratory source of x-rays in the world. For the few nanoseconds of a Z Machine test, its electrical output equals the output of 50x the electrical generating stations of all the power plants on earth. The Z Machine complex encompasses an area roughly the size of a major college basketball arena. Originally created to validate nuclear weapons models, the Z Machine is also considered a "dark horse" in the race for viable fusion energy production. After the famous "arcs and sparks" photo of Z (a photo no longer possible after its refurbishment), this is a fast-motion video of workers completing Z's recent refurbishment.

  11. Effect of Calabash Chalk on the Histomorphology of the Gastro-Oesophageal Tract of Growing Wistar Rats

    PubMed Central

    Moses, B Ekong; Emma, E John; Christopher, C Mbadugha; Enobong I, Bassey; Theresa, B Ekanem

    2012-01-01

    Background: Calabash chalk is a naturally occurring mineral consumed by members of some Nigerian communities for pleasure and by pregnant women as a remedy for morning sickness. The consumption of this geophagic material motivated our interest on the effect of the chalk on the histomorphology of the gastro-oesophageal tract. Methods: Twenty-eight young Wistar rats, 4 weeks old, were divided into 4 groups of equal size. Group 1 animals served as controls and received 1 mL of distilled water. Groups 2, 3, and 4 received orally 1 mL of a Calabash chalk suspension containing 40 mg/mL for 14, 21, and 28 days, respectively. Upon completion of the treatments, the animals in groups 2, 3, and 4 were sacrificed on days 15, 22, and 29, respectively, and the control group animals were sacrificed on day 29. All animals were euthanised using chloroform anaesthesia. The oesophagus and the stomach of each animal were dissected out and routinely processed for histological studies. Results: There was oedema with haemorrhages in the mucosa of the stomach, and acanthosis, hyperkeratosis, and koilocytic changes were observed in the mucosa of the oesophagus of the groups treated with 40 mg/mL of Calabash chalk suspension. Conclusion: Calabash chalk caused histological changes to the stomach and the oesophagus that may lead to other pathophysiological conditions. PMID:22977372

  12. Caoxite-hydroxyapatite composition as consolidating material for the chalk stone from Basarabi-Murfatlar churches ensemble

    NASA Astrophysics Data System (ADS)

    Ion, Rodica-Mariana; Turcanu-Caruţiu, Daniela; Fierăscu, Radu-Claudiu; Fierăscu, Irina; Bunghez, Ioana-Raluca; Ion, Mihaela-Lucia; Teodorescu, Sofia; Vasilievici, Gabriel; Rădiţoiu, Valentin

    2015-12-01

    The development of new composition for surface conservation of some architectural monuments represents now an important research topic. The Basarabi-Murfatlar Ensemble, recognized as the first religious monument from mediaeval Dobrogea (Romania) (from 9th to 11th century), is one of the most impressive archaeological sites of Europe. This ensemble is built from amorphous calcium carbonate, very sensitive to humidity, frost, salts, etc. The aim of this paper is to test on chalk stone samples a new consolidant - hydroxyapatite (HAp) mixed with calcium oxalate trihydrate (caoxite) (COT). Some specific techniques for evaluation its impact on chalk stone surface are used, as follows: petrographical and physical-chemical techniques: SEM, OM, ICP-AES, TGA, FTIR and Raman spectroscopy, chromatic parameters changes, the accelerated weathering tests: heating, freeze-thaw, and their effects on porosity and capillary water uptake by the chalk surface. All these have been evaluated before and after treatment with COT-HAp, putting into evidence the effect of the new composition on the chalk stone surface. HAp induces COT stabilization, and their joint composition can bind weathered stone blocks providing a substantial reinforcement of chalk surface.

  13. In Situ Production of Chlorine-36 in the Eastern Snake River Plain Aquifer, Idaho: Implications for Describing Ground-Water Contamination Near a Nuclear Facility

    SciTech Connect

    L. D. Cecil; L. L. Knobel; J. R. Green; S. K. Frape

    2000-06-01

    The purpose of this report is to describe the calculated contribution to ground water of natural, in situ produced 36Cl in the eastern Snake River Plain aquifer and to compare these concentrations in ground water with measured concentrations near a nuclear facility in southeastern Idaho. The scope focused on isotopic and chemical analyses and associated 36Cl in situ production calculations on 25 whole-rock samples from 6 major water-bearing rock types present in the eastern Snake River Plain. The rock types investigated were basalt, rhyolite, limestone, dolomite, shale, and quartzite. Determining the contribution of in situ production to 36Cl inventories in ground water facilitated the identification of the source for this radionuclide in environmental samples. On the basis of calculations reported here, in situ production of 36Cl was determined to be insignificant compared to concentrations measured in ground water near buried and injected nuclear waste at the INEEL. Maximum estimated 36Cl concentrations in ground water from in situ production are on the same order of magnitude as natural concentrations in meteoric water.

  14. Investigation of Thermal Hydraulics of a Nuclear Reactor Moderator

    NASA Astrophysics Data System (ADS)

    Sarchami, Araz

    A three-dimensional numerical modeling of the thermo hydraulics of Canadian Deuterium Uranium (CANDU) nuclear reactor is conducted. The moderator tank is a Pressurized heavy water reactor which uses heavy water as moderator in a cylindrical tank. The main use of the tank is to bring the fast neutrons to the thermal neutron energy levels. The moderator tank compromises of several bundled tubes containing nuclear rods immersed inside the heavy water. It is important to keep the water temperature in the moderator at sub-cooled conditions, to prevent potential failure due to overheating of the tubes. Because of difficulties in measuring flow characteristics and temperature conditions inside a real reactor moderator, tests are conducted using a scaled moderator in moderator test facility (MTF) by Chalk River Laboratories of Atomic Energy of Canada Limited (CRL, AECL). MTF tests are conducted using heating elements to heat tube surfaces. This is different than the real reactor where nuclear radiation is the source of heating which results in a volumetric heating of the heavy water. The data recorded inside the MTF tank have shown levels of fluctuations in the moderator temperatures and requires in depth investigation of causes and effects. The purpose of the current investigation is to determine the causes for, and the nature of the moderator temperature fluctuations using three-dimensional simulation of MTF with both (surface heating and volumetric heating) modes. In addition, three dimensional simulation of full scale actual moderator tank with volumetric heating is conducted to investigate the effects of scaling on the temperature distribution. The numerical simulations are performed on a 24-processor cluster using parallel version of the FLUENT 12. During the transient simulation, 55 points of interest inside the tank are monitored for their temperature and velocity fluctuations with time.

  15. A Novel In-Beam Delayed Neutron Counting Technique for Characterization of Special Nuclear Materials

    NASA Astrophysics Data System (ADS)

    Bentoumi, G.; Rogge, R. B.; Andrews, M. T.; Corcoran, E. C.; Dimayuga, I.; Kelly, D. G.; Li, L.; Sur, B.

    2016-12-01

    A delayed neutron counting (DNC) system, where the sample to be analyzed remains stationary in a thermal neutron beam outside of the reactor, has been developed at the National Research Universal (NRU) reactor of the Canadian Nuclear Laboratories (CNL) at Chalk River. The new in-beam DNC is a novel approach for non-destructive characterization of special nuclear materials (SNM) that could enable identification and quantification of fissile isotopes within a large and shielded sample. Despite the orders of magnitude reduction in neutron flux, the in-beam DNC method can be as informative as the conventional in-core DNC for most cases while offering practical advantages and mitigated risk when dealing with large radioactive samples of unknown origin. This paper addresses (1) the qualification of in-beam DNC using a monochromatic thermal neutron beam in conjunction with a proven counting apparatus designed originally for in-core DNC, and (2) application of in-beam DNC to an examination of large sealed capsules containing unknown radioactive materials. Initial results showed that the in-beam DNC setup permits non-destructive analysis of bulky and gamma shielded samples. The method does not lend itself to trace analysis, and at best could only reveal the presence of a few milligrams of 235U via the assay of in-beam DNC total counts. Through analysis of DNC count rates, the technique could be used in combination with other neutron or gamma techniques to quantify isotopes present within samples.

  16. Accelerator breeder: a viable option for the production of nuclear fuels

    SciTech Connect

    Grand, P.

    1983-01-01

    Despite the growing pains of the US nuclear power industry, our dependence on nuclear energy for the production of electricity and possibly process heat is likely to increase dramatically over the next few deacades. This statement dismisses fusion as being entirely too speculative to be practical within that time frame. Sometime, between the years 2000 and 2050, fissile material will be in short supply whether it is to fuel existing LWR's or to provide initial fuel inventory for FBR's. The accelerator breeder could produce the fuel shortfall predicted to occur during the first half of the 21st century. The accelerator breeder offers the only practical means today of producing, or breeding, large quantities of fissile fuel from fertile materials, albeit at high cost. Studies performed over the last few years at Chalk River Laboratory and at Brookhaven National Laboratory have demonstrated that the accelerator breeder is practical, technically feasible with state-of-the-art technology, and is economically competitive with any other proposed synthetic means of fissile fuel production. This paper gives the parameters of a nearly optimized accelerator-breeder system, then discusses the development needs, and the economics and institutional problems that this breeding concept faces.

  17. LCOGT Imaging Lab

    NASA Astrophysics Data System (ADS)

    Tufts, Joseph R.; Lobdill, Rich; Haldeman, Benjamin J.; Haynes, Rachel; Hawkins, Eric; Burleson, Ben; Jahng, David

    2008-07-01

    The Las Cumbres Observatory Global Telescope Network (LCOGT) is an ambitious project to build and operate, within 5 years, a worldwide robotic network of 50 0.4, 1, and 2 m telescopes sharing identical instrumentation and optimized for precision photometry of time-varying sources. The telescopes, instrumentation, and software are all developed in house with two 2 m telescopes already installed. The LCOGT Imaging Lab is responsible for assembly and characterization of the network's cameras and instrumentation. In addition to a fully equipped CNC machine shop, two electronics labs, and a future optics lab, the Imaging Lab is designed from the ground up to be a superb environment for bare detectors, precision filters, and assembled instruments. At the heart of the lab is an ISO class 5 cleanroom with full ionization. Surrounding this, the class 7 main lab houses equipment for detector characterization including QE and CTE, and equipment for measuring transmission and reflection of optics. Although the first science cameras installed, two TEC cooled e2v 42-40 deep depletion based units and two CryoTiger cooled Fairchild Imaging CCD486-BI based units, are from outside manufacturers, their 18 position filter wheels and the remainder of the network's science cameras, controllers, and instrumentation will be built in house. Currently being designed, the first generation LCOGT cameras for the network's 1 m telescopes use existing CCD486-BI devices and an in-house controller. Additionally, the controller uses digital signal processing to optimize readout noise vs. speed, and all instrumentation uses embedded microprocessors for communication over ethernet.

  18. Pumping test analysis using a layered cylindrical grid numerical model in a complex, heterogeneous chalk aquifer

    NASA Astrophysics Data System (ADS)

    Mansour, M. M.; Hughes, A. G.; Spink, A. E. F.; Riches, J.

    2011-04-01

    SummaryA groundwater investigation including several pumping tests has been carried out by Thames Water Utilities Limited (TWUL) to improve the understanding of the distribution of hydraulic properties of the Chalk in the Swanscombe area of Kent in south-eastern England. The pumping test behaviour is complicated by: the fractured condition of the Chalk, simultaneous pumping from adjacent boreholes, and variable pumping rates during the test. In addition, the groundwater flow system is complicated by quarrying of the Chalk. Analytical solutions for pumping test analysis fail to represent these complex flow processes and cannot reproduce the observed time-drawdown curves. A layered cylindrical grid numerical model has been applied to the results of the Swanscombe pumping test. This model can represent the heterogeneity of the aquifer and the detailed flow processes close to the abstraction borehole such as well storage, seepage face and well losses. It also includes a numerical representation of the moving water-table using a grid that deforms to eliminate numerical instabilities. The analyses of the test results demonstrate that they are significantly influenced by fracture flow, which needs to be included to improve the simulation of the groundwater system; not withstanding this, the layered cylindrical grid numerical model reproduced many of the features in observed time-drawdown, which allowed an assessment of the hydraulic characteristics of the aquifer as well as the investigation of the impact of quarries on the test results. This has demonstrated that the numerical model is a powerful tool that can be used to analyse complex pumping tests and aid to improvement of the conceptual understanding of a groundwater system.

  19. Sequential Pumping and Tracing Experiments Using Packer Systems in a Chalk Aquifer

    NASA Astrophysics Data System (ADS)

    Goderniaux, P.; Poulain, A.

    2016-12-01

    The hydraulic characterization of subsurface geological unit is crucial for many hydrogeological applications. The quantification and the spatial distribution of the related parameters is however not always straightforward. As a consequence, parameters values are often considered as homogeneous over the thickness of an aquifer unit. To try to catch the possible heterogeneity, sequential tracer and pumping tests have been performed between two piezometers, using inflatable packer systems to isolate and study specific sections of the boreholes. The experimental site is composed of two 50m-deep piezometers located in a chalk aquifer, in South-West Belgium. The boreholes are not equipped with any casing or screen, to allow the use of the packers. The chalk is characterized by a high porosity, which enables the storage of large quantities of groundwater, and by fractures where fast preferential flow occurs. Recordings made with a borehole camera system has evidenced the presence of many fractures along the borehole, with a mean density of 2 fractures by meter. The frequency of fracture occurrences is however variable along the borehole. Pumping and tracer tests have been performed (1) using the whole borehole depth, and (2) over specific 1-meter sections, isolated with packers. Results confirm that flow and transport parameters are heterogeneous within the chalk aquifer unit. Groundwater head variations, induced by water pumping or injection, and tracer transfer times are variable according to the studied borehole section. Tests are still going on, and the objective is to have measurements over the whole borehole, to be used for numerical interpretation.

  20. The NOAO Data Lab

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, M.; Olsen, K.; Stobie, E. B.; Mighell, K. J.; Norris, P.

    2015-09-01

    We describe the NOAO Data Lab to help community users take advantage of current large surveys and prepare them even larger surveys in the era of LSST. The Data Lab will allow users to efficiently utilize catalogs of billions of objects, combine traditional telescope image and spectral data with external archives, share custom results with collaborators, publish data products to other users, and experiment with analysis toolkits. Specific science cases will be used to develop a prototype framework and tools, allowing us to work directly with scientists from survey teams to ensure development remains focused on scientifically productive tasks.

  1. Canadian ADL Partnership Lab

    DTIC Science & Technology

    2009-08-19

    WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Canadian Defense Academy,PO Box 17000 Station Forces ,Kingston ON CANADA K7K 7B4...CMP Canadian ADL Partnership Lab Presentation by CDA Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the... Canadian ADL Partnership Lab 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

  2. SenseLab

    PubMed Central

    Crasto, Chiquito J.; Marenco, Luis N.; Liu, Nian; Morse, Thomas M.; Cheung, Kei-Hoi; Lai, Peter C.; Bahl, Gautam; Masiar, Peter; Lam, Hugo Y.K.; Lim, Ernest; Chen, Huajin; Nadkarni, Prakash; Migliore, Michele; Miller, Perry L.; Shepherd, Gordon M.

    2009-01-01

    This article presents the latest developments in neuroscience information dissemination through the SenseLab suite of databases: NeuronDB, CellPropDB, ORDB, OdorDB, OdorMapDB, ModelDB and BrainPharm. These databases include information related to: (i) neuronal membrane properties and neuronal models, and (ii) genetics, genomics, proteomics and imaging studies of the olfactory system. We describe here: the new features for each database, the evolution of SenseLab’s unifying database architecture and instances of SenseLab database interoperation with other neuroscience online resources. PMID:17510162

  3. SmallSat Lab

    DTIC Science & Technology

    2014-03-05

    CubeSat. Mr. Alvarez worked with four students on the PCB layout for the solar panels and the construction of the 6U CubeSat mockup . Support for Mr...Hull and Mr. Alvarez was $49k including fringe benefits. !! Purchases: During this time period a license for MatLab software and the Princeton...Satellite ToolBox was purchased using funds from this award. This software adds tremendous capability to the SmallSat Lab by enabling students to analyze

  4. Spatial heterogeneity of high-resolution Chalk groundwater geochemistry - Underground quarry at Saint Martin-le-Noeud, France

    NASA Astrophysics Data System (ADS)

    Barhoum, S.; Valdès, D.; Guérin, R.; Marlin, C.; Vitale, Q.; Benmamar, J.; Gombert, P.

    2014-11-01

    Chalk groundwater is an important aquifer resource in France because it accounts for a production of 12 million m3 y-1 with a large proportion reserved for drinking water. Processes occurring in the unsaturated zone (UZ) and the overlying superficial formations have a high impact on Chalk groundwater geochemistry and require better understanding. The study site is a former underground Chalk quarry located near Beauvais (France) that extends over 1200 m in length, at a depth ranging from 20 to 30 m. The water table intersects the cavity creating 15 underground “lake” that give access to the Chalk groundwater. Lakes geochemistry has been studied: water samples were collected in July 2013 and major ion concentrations were analyzed. UZ and clay-with-flints thickness above each lake were estimated qualitatively using an electromagnetic sensor (EM31) and Underground GPS. The results unexpectedly showed that groundwater quality varied widely in spatial terms for both allochthonous and autochthonous ions (e.g., HCO3- ranged from 2.03 to 4.43 meq L-1, NO3- ranged from 0.21 to 1.33 meq L-1). Principal component analysis indicated the impact of agricultural land use on water quality, with the intake of NO3- as well as SO42-, Cl- and Ca2+. Chalk groundwater geochemistry is compared with the nature and structure of the UZ. We highlight correlations (1) between thick clay-with-flints layers and the ions Mg2+ and K+, and (2) between UZ thickness and Na+. In conclusion, this paper identifies various ion sources (agriculture, clay-with-flints and Chalk) and demonstrates different processes in the UZ: dissolution, ionic exchange and solute storage.

  5. International Intercomparison Exercise for Nuclear Accident Dosimetry at the DAF Using GODIVA-IV

    SciTech Connect

    Hickman, David; Hudson, Becka

    2016-12-15

    The Nuclear Criticality Safety Program operated under the direction of Dr. Jerry McKamy completed the first NNSA Nuclear Accident Dosimetry exercise on May 27, 2016. Participants in the exercise were from Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), Savanah River Site (SRS), Pacific Northwest National Laboratory (PNNL), US Navy, the Atomic Weapons Establishment (United Kingdom) under the auspices of JOWOG 30, and the Institute for Radiological Protection and Nuclear Safety (France) by special invitation and NCSP memorandum of understanding. This exercise was the culmination of a series of Integral Experiment Requests (IER) that included the establishment of the Nuclear Criticality Experimental Research Center, (NCERC) the startup of the Godiva Reactor (IER-194), the establishment of a the Nuclear Accident Dosimetry Laboratory (NAD LAB) in Mercury, NV, and the determination of reference dosimetry values for the mixed neutron and photon radiation field of Godiva within NCERC.

  6. Results of 2001 Groundwater Sampling in Support of Conditional No Longer Contained-In Determination for the Snake River Plain Aquifer in the Vicinity of the Idaho Nuclear Technology and Engineering Center

    SciTech Connect

    Meachum, T.R.

    2002-04-26

    This report summarizes the results of sampling five groundwater monitoring wells in the vicinity of the Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory in 2001. Information on general sampling practices, quality assurance practices, parameter concentrations, representativeness of sampling results, and cumulative cancer risk are presented. The information is provided to support a conditional No Longer Contained-In Determination for the Snake River Plain Aquifer in the vicinity of the Idaho Nuclear Technology and Engineering Center.

  7. The flow mechanism in the Chalk based on radio-isotope analyses of groundwater in the London Basin

    USGS Publications Warehouse

    Downing, R.A.; Pearson, F.J.; Smith, D.B.

    1979-01-01

    14C analyses of groundwaters from the Chalk of the London Basin are re-interpreted and the age of the groundwater is revised. Radio-isotope analyses are used to examine the flow mechanism in the aquifer. The evidence supports the view that a network of micro-fissures and larger intergranular pores in the matrix provides a significant part of the water pumped from Chalk wells and the major fissures distribute the water to the wells. Most of the matrix is fine-grained and contains a very old water. This diffuses into the micro-fissures and larger pores and is carried to the wells by the major fissures. ?? 1979.

  8. Environmental resources and potential impacts for a nuclear energy center near Green River, Utah. Volume II. Maps

    SciTech Connect

    Not Available

    1981-01-01

    Maps are included for baseline studies for siting a nuclear energy park. Surface waters, ground water, water resources, forests, plant flora, land use, land ownership and mineral deposits are detailed. (PSB)

  9. The Haunted Physics Lab

    NASA Astrophysics Data System (ADS)

    Zepf, Thomas H.

    2004-10-01

    During the Halloween season at Creighton University, our students and the public are treated to a haunted physics laboratory. Visitors to the lab learn physics while having fun as they are confronted with a maze of exhibits that demonstrate optical, electrical, and mechanical phenomena in the context of Halloween.

  10. Lab with Dad

    ERIC Educational Resources Information Center

    Havers, Brenda; Delmotte, Karen

    2012-01-01

    Family science nights are fantastic, but planning one can be overwhelming, especially when one considers the already overloaded schedule of a classroom teacher. To overcome this challenge, the authors--colleagues with a mutual love of science--developed a much simpler annual event called "Lab With Dad." The purpose was for one target age group of…

  11. Inside Linden Lab

    ERIC Educational Resources Information Center

    Atkinson, Tom

    2008-01-01

    In this article, the author provides an overview of Second Life[trademark], or simply SL, which was developed at Linden Lab, a San Francisco-based corporation. SL is an online society within a threee-dimensional virtual world entirely built and owned by its residents, where they can explore, build, socialize and participate in their own economy.…

  12. Inside Linden Lab

    ERIC Educational Resources Information Center

    Atkinson, Tom

    2008-01-01

    In this article, the author provides an overview of Second Life[trademark], or simply SL, which was developed at Linden Lab, a San Francisco-based corporation. SL is an online society within a threee-dimensional virtual world entirely built and owned by its residents, where they can explore, build, socialize and participate in their own economy.…

  13. Walheim in US Lab

    NASA Image and Video Library

    2011-07-11

    S135-E-007434 (11 July 2011) --- NASA astronaut Rex Walheim, STS-135 mission specialist, is pictured in the U.S. lab or Destiny on the International Space Station during the fourth day in space for the Atlantis crew and the second day during which the two spacecraft are docked in Earth orbit. Photo credit: NASA

  14. Magnus in US Lab

    NASA Image and Video Library

    2011-07-11

    S135-E-007435 (11 July 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, is pictured in the U.S. lab or Destiny on the International Space Station during the fourth day in space for the Atlantis crew and the second day while the two spacecraft are docked in Earth orbit. Photo credit: NASA

  15. Elemental Chem Lab

    ERIC Educational Resources Information Center

    Franco Mariscal, Antonio Joaquin

    2008-01-01

    This educative material uses the symbols of 45 elements to spell the names of 32 types of laboratory equipment usually found in chemical labs. This teaching material has been divided into three puzzles according to the type of the laboratory equipment: (i) glassware as reaction vessels or containers; (ii) glassware for measuring, addition or…

  16. Modifying Cookbook Labs.

    ERIC Educational Resources Information Center

    Clark, Robert, L.; Clough, Michael P.; Berg, Craig A.

    2000-01-01

    Modifies an extended lab activity from a cookbook approach for determining the percent mass of water in copper sulfate pentahydrate crystals to one which incorporates students' prior knowledge, engenders active mental struggling with prior knowledge and new experiences, and encourages metacognition. (Contains 12 references.) (ASK)

  17. Serial Dilution Simulation Lab

    ERIC Educational Resources Information Center

    Keler, Cynthia; Balutis, Tabitha; Bergen, Kim; Laudenslager, Bryanna; Rubino, Deanna

    2010-01-01

    Serial dilution is often a difficult concept for students to understand. In this short dry lab exercise, students perform serial dilutions using seed beads. This exercise helps students gain skill at performing dilutions without using reagents, bacterial cultures, or viral cultures, while being able to visualize the process.

  18. Materials Lab Equipment

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The photo shows one of the waveguide setups in the Electromaganetic Properties Measurements Lab (EPML). This setup is for measuring permittivity and permeability of the materials at the L-band frequencies (1.12-1.7 ghz). The EMPL is in the Elecromagnetics Research Branch at NASA Langley.

  19. Modifying Cookbook Labs.

    ERIC Educational Resources Information Center

    Clark, Robert, L.; Clough, Michael P.; Berg, Craig A.

    2000-01-01

    Modifies an extended lab activity from a cookbook approach for determining the percent mass of water in copper sulfate pentahydrate crystals to one which incorporates students' prior knowledge, engenders active mental struggling with prior knowledge and new experiences, and encourages metacognition. (Contains 12 references.) (ASK)

  20. The Crime Lab Project.

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2003-01-01

    Describes the Crime Lab Project, which takes an economical, hands-on, interdisciplinary approach to studying the career of forensics in the middle or high school classroom. Includes step-by-step student requirements for the investigative procedure, a sample evidence request form, and an assessment rubric. (KHR)

  1. USDA gin lab updates

    USDA-ARS?s Scientific Manuscript database

    There are four USDA-ARS labs involved in cotton harvesting, processing & fiber quality research; The Southwestern Cotton Ginning Research Laboratory (Mesilla Park, NM); The Cotton Production and Processing Unit (Lubbock, TX); The Cotton Ginning Research Unit (Stoneville, MS); and The Cotton Structur...

  2. Writing Better Lab Reports

    ERIC Educational Resources Information Center

    Porter, Rhiannon; Guarienti, Kristy; Brydon, Barbara; Robb, Jeanine; Royston, Ann; Painter, Heidi; Sutherland, Alex; Passmore, Cynthia; Smith, Martin H.

    2010-01-01

    As science teachers at a suburban California high school, the authors were concerned about the lab report conclusions written by their upper-level chemistry, biology, and ecology students--which were consistently of poor quality. Their work lacked inferences derived from data and support for their concluding statements. Working as part of a…

  3. Computer Labs: New Perceptions.

    ERIC Educational Resources Information Center

    Prochaska, Nancy

    1989-01-01

    Describes the use of computer labs in a Texas high school. Highlights include word processing; a study skills course; software programs currently in use by English and English-as-a-Second-Language classes; physical layout, including security considerations and furniture; hardware, including printers; and guidelines for the selection of software.…

  4. Elemental Chem Lab

    ERIC Educational Resources Information Center

    Franco Mariscal, Antonio Joaquin

    2008-01-01

    This educative material uses the symbols of 45 elements to spell the names of 32 types of laboratory equipment usually found in chemical labs. This teaching material has been divided into three puzzles according to the type of the laboratory equipment: (i) glassware as reaction vessels or containers; (ii) glassware for measuring, addition or…

  5. A Big Bang Lab

    ERIC Educational Resources Information Center

    Scheider, Walter

    2005-01-01

    The February 2005 issue of The Science Teacher (TST) reminded everyone that by learning how scientists study stars, students gain an understanding of how science measures things that can not be set up in lab, either because they are too big, too far away, or happened in a very distant past. The authors of "How Far are the Stars?" show how the…

  6. A Big Bang Lab

    ERIC Educational Resources Information Center

    Scheider, Walter

    2005-01-01

    The February 2005 issue of The Science Teacher (TST) reminded everyone that by learning how scientists study stars, students gain an understanding of how science measures things that can not be set up in lab, either because they are too big, too far away, or happened in a very distant past. The authors of "How Far are the Stars?" show how the…

  7. The Crime Lab Project.

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2003-01-01

    Describes the Crime Lab Project, which takes an economical, hands-on, interdisciplinary approach to studying the career of forensics in the middle or high school classroom. Includes step-by-step student requirements for the investigative procedure, a sample evidence request form, and an assessment rubric. (KHR)

  8. Serial Dilution Simulation Lab

    ERIC Educational Resources Information Center

    Keler, Cynthia; Balutis, Tabitha; Bergen, Kim; Laudenslager, Bryanna; Rubino, Deanna

    2010-01-01

    Serial dilution is often a difficult concept for students to understand. In this short dry lab exercise, students perform serial dilutions using seed beads. This exercise helps students gain skill at performing dilutions without using reagents, bacterial cultures, or viral cultures, while being able to visualize the process.

  9. Magnus in US Lab

    NASA Image and Video Library

    2011-07-16

    S135-E-008732 (16 July 2011) --- NASA astronaut Sandy Magnus, STS-135 mission specialist, is pictured in the U.S. lab or Destiny on the International Space Station during the 11th day in space for the four crew members of the STS-135 Atlantis mission. Photo credit: NASA

  10. PRIME lab AMS performance, upgrades and research applications

    NASA Astrophysics Data System (ADS)

    Sharma, P.; Bourgeois, M.; Elmore, D.; Granger, D.; Lipschutz, M. E.; Ma, X.; Miller, T.; Mueller, K.; Rickey, F.; Simms, P.; Vogt, S.

    2000-10-01

    The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is a dedicated research and service facility for AMS that provides the scientific community with timely, reliable and high quality chemical processing (~600 samples/year) and AMS measurements (~3000 samples/year) of 10Be, 14C, 26Al, 36Cl, 41Ca and 129I. The AMS system is based on an upgraded FN (7 MV) tandem accelerator that has recently been modified to improve performance. The precision is 1% for 14C and it is 3-5% for the other nuclides for radioisotope/stable isotope ratios at the 10-12 levels. System background for 10Be, 14C, 26Al, 36Cl and 41Ca is 1-10×10-15 while for 129I the natural abundance limits it to 20×10-15. Research is being carried out in Earth, planetary, and biomedical sciences. Geoscience applications include determination of exposure ages of glacial moraines, volcanic eruptions, river terraces, and fault scarps. Burial histories of sand are being determined to decipher the timing of human expansion and climatic history. Environmental applications are tracing the release of radioactivity from nuclear fuel reprocessing plants, water tracing, and neutron dosimetry. The applications using meteoric nuclides are oil field brines, sediment subduction, radiocarbon dating, and groundwater 36Cl mapping. Radionuclide concentrations are also determined in meteorites and tektites for deciphering space and terrestrial exposure histories.

  11. Why national labs?

    SciTech Connect

    Wiley, H. S.

    2008-06-01

    Biologists are defined by both their field of investigation and where they work. When I was a tenured university professor in the pathology department of a medical school, my colleagues scientists seemed to understand what I did for a living. Now that I work at a national laboratory, I am more likely to be greeted with blank stares. The questions that I do get, such as whether I need to write research grants (I do) or whether I work on the energy problem (I don’t), indicates a pervasive lack of understanding of the nature of national labs and their important roles in biological research. The national labs were largely responsible for a new phase of biology. DOE started the Human Genome Project to understand the molecular basis of radiation damage. GenBank began at Los Alamos National Laboratory in the early 1980s to manage the increasing amounts of DNA sequence data. The high-intensity x-ray sources found at national labs began being used to rapidly solve protein structures. These projects required a level of technical sophistication and scale that were well beyond most universities. This, together with a lack of departmental boundaries and a tradition of multidisciplinary teamwork, made national labs an excellent environment for tackling challenging problems in biology. I believe that most academic scientists are unaware of the research that goes on at national labs, mostly due to our small size and general focus on advanced technology. Biology has traditionally been more labor intensive than technology dependent, which plays to the natural strengths of universities. However, this is likely to change in the next several years.

  12. Mechanical and chemical processes affecting the chalk during burial, insights from combined reflection seismics, well data and field work

    NASA Astrophysics Data System (ADS)

    Moreau, Julien; Boussaha, Myriam; Nielsen, Lars; Thibault, Nicolas; Stemmerik, Lars

    2014-05-01

    The chalk must undergo several phases of grain reorganisation and chemical reactions during its diagenetic evolution from a carbonaceous ooze to a sedimentary rock. Some of these transformations could be observed on structures from the kilometre- to the micrometre-scale with seismic reflection and cores analyses, respectively. However, few sites allow to combine all the different scale of observation for chalk diagenesis. Onshore and offshore high resolution seismics, two fully cored >350 m wells with wireline logging tools and very high quality exposures from a coastal cliff and a quarry form such an exceptional dataset in the Stevns peninsula area, eastern Danish Basin (Denmark). The studied chalk interval in the area is of Maastrichtian to Danian age. The chalk has been divided in 4 lithofacies, chalk-marl alternations, white chalk, white chalk with flint layers and bryozoan chalk. Advanced stratigraphic works have been performed with astronomical calibration based on stable isotope stratigraphy, wireline logs as well as several palaeontological proxies and detailed sedimentological analysis. Since a couple of decades, a specific kind of fractures has been described in the Chalk of Denmark, the so-called hairline fractures. They have recently been interpreted as compaction bands associated with the pore collapse of the chalk. We have observed these fractures on the field and on the cores in specific intervals. At depth, these fractures are in genetic relation with the formation of some stylolithes. The pressure-solution allows the formation of carbonate seams in the hairline fractures. At larger scale, on the field are observed faults which are sealed with flint precipitations. They slightly offset (<1 m) strata underlined by flint bands. On the onshore and offshore seismic reflection profiles, numerous strata-bound faults form noisy intervals as well as amplitude anomalies. Their normal offsets are less than 25 m. Their branching patterns, and their restriction

  13. Acoustic sensors for fission gas characterization: R and D skills devoted to innovative instrumentation in MTR, non-destructive devices in hot lab facilities and specific transducers for measurements of LWR rods in nuclear plants

    SciTech Connect

    Ferrandis, J.Y.; Leveque, G.; Rosenkrantz, E.; Augereau, F.; Combette, P.

    2015-07-01

    pressure and composition measurement by an acoustic sensor was conducted successfully between 2008 and 2010 on 5 high burn-up MOX fuel rods and 2 very high burn-up UO{sub 2} fuel rods in LECA Facility at Cadarache Centre. An improvement of this sensor has been proposed, allowing us to divide by two the uncertainty on the pressure measurement. In the case of hot-cell measurements, viscous liquid can be used to couple the sensor with the rod. For gas content with a pressure exceeding 15 bars and a 10% Xe/Kr ratio, such coupling may reduce relative acoustic method accuracy by ±7% for pressure measurement result and ±0.25 % for the assessment of gas composition. These results make it possible to demonstrate the feasibility of the technique on LWR fuel rods. The transducer and the associated methodology are now operational for non-destructive measurements in hot lab facilities and allow characterising the fission gas without puncturing the fuel rods. Up to now, any other non-destructive method can be proposed. A next step will be the development of an industrial application in a fuel storage pool in order to perform a large number of measurements on a fuel assembly in nuclear plants.

  14. Hydrological processes in the Chalk unsaturated zone - Insights from an intensive field monitoring programme

    NASA Astrophysics Data System (ADS)

    Ireson, A. M.; Wheater, H. S.; Butler, A. P.; Mathias, S. A.; Finch, J.; Cooper, J. D.

    2006-10-01

    As part of the NERC lowland catchment research programme (LOCAR), the Pang-Lambourn catchments (Berkshire, UK) have been extensively instrumented to provide an improved understanding of the hydrological processes in the unsaturated zone of the Chalk - a subject of much debate over the past 30 years. To quantify the movement of water through the unsaturated zone it is necessary to measure matric potential and water content (as well as input and output fluxes from precipitation, evapotranspiration and groundwater recharge). Previous studies have indicated the need for fine temporal resolution data to monitor this system effectively. Due to the challenges faced in meeting this objective, a monitoring scheme was designed that combines a variety of instrumentation to provide the required range, accuracy and spatial and temporal resolution of data. This paper firstly presents an overview of the monitoring programme and a critical discussion of the instrumentation used. Subsequently, the field data are used to characterise the hydrological properties of the unsaturated zone and to gain insight into recharge processes. The interpretation of the data presented in this paper indicate that, in the Chalk unsaturated zone at West Ilsley, matrix flow is the dominant recharge mechanism.

  15. Nanoscale Pore Imaging and Pore Scale Fluid Flow Modeling in Chalk

    SciTech Connect

    Tomutsa, Liviu; Silin, Dmitriy

    2004-08-19

    For many rocks of high economic interest such as chalk, diatomite, tight gas sands or coal, nanometer scale resolution is needed to resolve the 3D-pore structure, which controls the flow and trapping of fluids in the rocks. Such resolutions cannot be achieved with existing tomographic technologies. A new 3D imaging method, based on serial sectioning and using the Focused Ion Beam (FIB) technology has been developed. FIB allows for the milling of layers as thin as 10 nanometers by using accelerated Ga+ ions to sputter atoms from the sample surface. After each milling step, as a new surface is exposed, a 2D image of this surface is generated. Next, the 2D images are stacked to reconstruct the 3D pore or grain structure. Resolutions as high as 10 nm are achievable using such a technique. A new robust method of pore-scale fluid flow modeling has been developed and applied to sandstone and chalk samples. The method uses direct morphological analysis of the pore space to characterize the petrophysical properties of diverse formations. Not only petrophysical properties (porosity, permeability, relative permeability and capillary pressures) can be computed but also flow processes, such as those encountered in various IOR approaches, can be simulated. Petrophysical properties computed with the new method using the new FIB data will be presented. Present study is a part of the development of an Electronic Core Laboratory at LBNL/UCB.

  16. Hydrological role of karst in the Chalk aquifer of Upper Normandy, France

    NASA Astrophysics Data System (ADS)

    El Janyani, Sanae; Dupont, Jean-Paul; Massei, Nicolas; Slimani, Smail; Dörfliger, Nathalie

    2014-05-01

    The role of karst on large-scale groundwater flow is defined for the Chalk aquifer of Upper Normandy (western Paris Basin), France. In the regional context, chalk plateaus occupy the greater part of watersheds and are the main sites of groundwater recharge. Previous studies focused on karstic output systems in the valleys and less on water-level variations in the recharge zones upstream. This study assesses the relevant hydrogeological processes using time-series data (boreholes and springs) recorded along a down-gradient hydrologeological cross-section in two selected watersheds. These hydrological data are interpreted in the framework of previous descriptions of the morphological organization of the study area's karst network. The results highlight the hydrological role of (1) the input karst (vertical conduits) which drains recharging water, (2) the output karst (sub-horizontal conduits widely developed in the vicinity of valleys in the surface watersheds) which drains the output flows, and (3) the connections between these two (input and output) networks, which control the upstream water levels and allow quick transfer to springs, particularly after strong rainfall events. A conceptual model of the hydrological functioning of this covered karst aquifer is established, which should serve for the structuring and parameterization of a numerical model.

  17. Hydrological responses of the chalk aquifer to the regional climatic signal

    NASA Astrophysics Data System (ADS)

    El Janyani, Sanae; Massei, Nicolas; Dupont, Jean-Paul; Fournier, Matthieu; Dörfliger, Nathalie

    2012-09-01

    SummaryPiezometric variability was investigated using monthly time series from 40 piezometers in different areas across the Upper Normandy region, over the 1968-2009 period. The piezometers were classified according to their hydrological behaviour. This paper aimed at characterising the dominant modes explaining piezometric variability and at investigating the causes of this variability. Significant components in the piezometric signals were identified: the annual cycle and an interannual mode (4-12 years) with different variances for each observation borehole group. The influence of the morphostructural organisation of the Upper Normandy chalk plateau on the modalities of the water level variability in the chalk aquifer was defined. The relative contributions and standard deviations of each component found in the signal time series of the groundwater level was estimated. The highest values were recorded in the Northern study area, and clay-with-flints and aquifer thicknesses influence the transfer on an annual scale, while the loess thickness influences the transfer on a multi-year scale.

  18. Resolution dependence of petrophysical parameters derived from X-ray tomography of chalk

    SciTech Connect

    Müter, D.; Sørensen, H. O.; Jha, D.; Harti, R.; Dalby, K. N.; Stipp, S. L. S.; Suhonen, H.; Feidenhans'l, R.; Engstrøm, F.

    2014-07-28

    X-ray computed tomography data from chalk drill cuttings were taken over a series of voxel dimensions, ranging from 320 to 25 nm. From these data sets, standard petrophysical parameters (porosity, surface area, and permeability) were derived and we examined the effect of the voxel dimension (i.e., image resolution) on these properties. We found that for the higher voxel dimensions, they are severely over or underestimated, whereas for 50 and 25 nm voxel dimension, the resulting values (5%–30% porosity, 0.2–2 m{sup 2}/g specific surface area, and 0.06–0.34 mD permeability) are within the expected range for this type of rock. We compared our results to macroscopic measurements and in the case of surface area, also to measurements using the Brunauer-Emmett-Teller (BET) method and found that independent of the degree of compaction, the results from tomography amount to about 30% of the BET method. Finally, we concluded that at 25 nm voxel dimension, the essential features of the nanoscopic pore network in chalk are captured but better resolution is still needed to derive surface area.

  19. Environmental review of Potomac Electric Power Company's proposed Chalk Point combustion turbine facility

    SciTech Connect

    Mountain, D.; Peters, N.; Rafalko, L.; Roth, C.; Brower, R.

    1990-06-01

    The Potomac Electric Power Company (PEPCO) has submitted an application to the Maryland Public Service Commission (PSC) for a license to build four combustion turbines on the property of its Chalk Point Generating Station. Environmental impacts of the proposed project are expected to be minimal. The facility will be small relative to the existing Chalk Point station; further, the large size of the overall PEPCO property and the rural character of the vicinity will serve to buffer the effects of the facility. The report discusses PEPCO's requested appropriations for ground water to meet the water needs of the proposed plant, and recommends that limitations lower than those requested by the utility be placed on ground water withdrawals. It is recommended that PEPCO be required to create a 23-acre tree preservation zone, or alternatively undertake the reforestation of 23 acres of currently unforested land in the vicinity of the site. PEPCO should also be required to monitor ambient noise levels at the property boundary after construction of the new units is completed, and to coordinate efforts with Prince George's County to alleviate any traffic congestion that may result from construction activities at the plant site.

  20. Chalk-calcite-microfluidic experiments: construction and flooding of microsystems with reactive fluids

    NASA Astrophysics Data System (ADS)

    Neuville, Amélie; Thuy Luu, Thi; Dysthe, Dag Kristian; Vinningland, Jan Ludvig; Hiorth, Aksel

    2015-04-01

    Direct in situ observation of the pore structure changes that occur when chalk is flooded with brines could resolve many of the open questions that remain about the interactions between mineralogical alterations and oil-liberating mechanisms. Experiments on core scale and field tests that have been carried out the last decade have clearly shown that water chemistry affects the final oil recovery. However, there is generally no consensus in the scientific community of why additional oil is released. In this work, our aim is to focus on in-situ observations of single phase flow and interactions at the pore scale. To do so, we create several types of custom-made microsystems with chalk and calcite crystals. We then do experiments with reacting fluids in these microsystems. During these experiments, we realize in-situ observations (geometrical characteristics, reaction rate) using microsopy techniques (white light vertical/phase shift interferometric microscopy, and classical microscopy), and show how they vary as function as the water chemistry. In simple systems made of calcite, we obtain reactive rates that are coherent with the litterature and with numerical simulations based on Lattice-Boltzmann methods.

  1. ERLN Lab Compendium Fact Sheet

    EPA Pesticide Factsheets

    The Compendium is an online database of environmental testing laboratories nationwide. It enables labs to create profiles of their capabilities, so emergency responders can quickly identify a lab that will meet their support needs.

  2. Labs That Are a Blast.

    ERIC Educational Resources Information Center

    Hendrix, Laura

    1996-01-01

    Presents activities that use a simple homemade apparatus called "the cannon" to demonstrate Newton's Third Law. Reviews the chemistry concepts behind the ignition of the cannon and presents the Momentum Lab and the Projectile Motion Lab. (JRH)

  3. Labs That Are a Blast.

    ERIC Educational Resources Information Center

    Hendrix, Laura

    1996-01-01

    Presents activities that use a simple homemade apparatus called "the cannon" to demonstrate Newton's Third Law. Reviews the chemistry concepts behind the ignition of the cannon and presents the Momentum Lab and the Projectile Motion Lab. (JRH)

  4. FURTHER DEVELOPMENT OF MODIFIED MONOSODIUM TITANATE, AN IMPROVED SORBENT FOR PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Taylor-Pashow, K.; Hobbs, D.; Fondeur, F.; Fink, S.

    2011-01-12

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for Cs-137 removal, and sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239, and Pu-240. This paper describes recent results from the development of an improved titanate material that exhibits increased removal kinetics and effective capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.

  5. Size-dependent distribution of radiocesium in riverbed sediments and its relevance to the migration of radiocesium in river systems after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tanaka, Kazuya; Iwatani, Hokuto; Sakaguchi, Aya; Fan, Qiaohui; Takahashi, Yoshio

    2015-01-01

    We investigated the particle size distribution of radiocesium in riverbed sediments after the Fukushima Daiichi Nuclear Power Plant accident. Riverbed sediments were collected in the Abukuma River system in Fukushima and Miyagi Prefectures. The collected sediments were separated into 11 fractions, ranging from granular size (>2000 μm) to clay size (<2 μm) fractions. Cesium-137 concentrations were higher in the smaller particle size fractions, possibly reflecting specific surface areas and the mineralogy, in particular the clay mineral content. A gap in (137)Cs concentration was observed between the silt size and sand size fractions of riverbed sediments at downstream sites, whereas riverbed sediments at an upstream site did not show such a concentration gap. It is likely that selective transport of small particles in suspended state from upstream areas resulted in an accumulation of radiocesium in downstream areas.

  6. Nuclear DNA identification of migrating bull trout captured at the Puget Sound Energy diversion dam on the White River, Washington State.

    PubMed

    Baker, J D; Moran, P; Ladley, R

    2003-02-01

    Bull trout (Salvelinus confluentus) is a char listed as threatened under the United States Endangered Species Act throughout its range in the coterminous United States. Substantial morphological similarities between bull trout and Dolly Varden (S. malma) make field identification difficult. This has resulted in an incomplete understanding of their distribution and abundance in Washington State where these two species occur sympatrically. We used three diagnostic nuclear loci to determine the species of char collected at a trap on the White River in southern Puget Sound (Washington State, USA). Each of the 104 samples revealed the expected bull trout genotype at all three loci. This work presents three principle results: (i) the presence of a migratory bull trout population in southern Puget Sound; (ii) no evidence of migratory Dolly Varden over 3 years; and (iii) no evidence of hybridization was detected. These results also demonstrate how molecular markers can provide information essential to the conservation and management of these species.

  7. Frequencies of erythrocyte nuclear abnormalities and of leucocytes in the fish Barbus peloponnesius correlate with a pollution gradient in the River Bregalnica (Macedonia).

    PubMed

    Rebok, Katerina; Jordanova, Maja; Slavevska-Stamenković, Valentina; Ivanova, Lozenka; Kostov, Vasil; Stafilov, Trajče; Rocha, Eduardo

    2017-03-10

    Integrated chemical and biomarker approaches were performed to estimate if there is ongoing toxicity in the River Bregalnica, namely connected with the presence of metals. The study was performed in water, sediment, and barbel (Barbus peloponnesius), collected in two seasons, from two suspected polluted and one reference zones. The water analyses revealed higher mean values in polluted sites for most of the examined physicochemical parameters. Metal concentrations (Zn, Cu, Cd, Mn, Pb, and Fe) in water were more or less constant, whereas in sediment, they were higher at the two polluted locations. Condition factor (CF), as a general health indicator, revealed better overall condition in barbel from the reference site. In general, blood parameters revealed higher values in the polluted localities. Irrespective of sex and/or season, the frequency of micronuclei (MN) and vacuolated nuclei (VN) were with higher rates in polluted sites. Similarly, the frequencies of the leucocytes (Le), binuclei (BN), and irregularly shaped nuclei (ISN) were also significantly increased in the polluted localities, but they seemed prone to be influenced by sex and/or season. However, strong positive correlations between blood biomarkers and most water physicochemical parameters and metal in sediment were estimated. Our data support that the River Bregalnica's lower course receives significant genotoxic pollution, likely via metal industry effluents, agricultural runoff, and domestic sewage, and reinforced the utility of MN and other nuclear abnormalities as sensitive and suitable biomarkers for genotoxicity when used in monitoring studies.

  8. Reactivity impact of {sup 16}O thermal elastic-scattering nuclear data for some numerical and critical benchmark systems

    SciTech Connect

    Kozier, K. S.; Roubtsov, D.; Plompen, A. J. M.; Kopecky, S.

    2012-07-01

    The thermal neutron-elastic-scattering cross-section data for {sup 16}O used in various modern evaluated-nuclear-data libraries were reviewed and found to be generally too high compared with the best available experimental measurements. Some of the proposed revisions to the ENDF/B-VII.0 {sup 16}O data library and recent results from the TENDL system increase this discrepancy further. The reactivity impact of revising the {sup 16}O data downward to be consistent with the best measurements was tested using the JENDL-3.3 {sup 16}O cross-section values and was found to be very small in MCNP5 simulations of the UO{sub 2} and reactor-recycle MOX-fuel cases of the ANS Doppler-defect numerical benchmark. However, large reactivity differences of up to about 14 mk (1400 pcm) were observed using {sup 16}O data files from several evaluated-nuclear-data libraries in MCNP5 simulations of the Los Alamos National Laboratory HEU heavy-water solution thermal critical experiments, which were performed in the 1950's. The latter result suggests that new measurements using HEU in a heavy-water-moderated critical facility, such as the ZED-2 zero-power reactor at the Chalk River Laboratories, might help to resolve the discrepancy between the {sup 16}O thermal elastic-scattering cross-section values and thereby reduce or better define its uncertainty, although additional assessment work would be needed to confirm this. (authors)

  9. Mineral, chemical and textural relationships in rhythmic-bedded, hydrocarbon-productive chalk of the Niobrara Formation, Denver Basin, Colorado ( USA).

    USGS Publications Warehouse

    Pollastro, R.M.; Martinez, C.J.

    1985-01-01

    The types of hydrocarbons produced from these chalks are determined by the level of thermal maturity associated with present-day burial or paleoburial conditions. Detailed analyses of deeply-buried chalk from core of the Smoky Hill Chalk Member of the Niobrara Formation in the Champlin Petroleum 2 Boxelder Farms well combined with core data from other Niobrara wells have helped identify many depositional and diagenetic relationships. Porosity of the chalk is proportional to maximum burial depth and inversely proportional to the amount of non-carbonate material (acid- insoluble residue content) in the chalk. Total organic carbon content in the chalk is proportional to the amount of acid-insoluble residue and relative abundance of pyrite in the acid-insoluble fraction. Quartz is inversely proportional to the amount of insoluble material, and the amount of clay tends to increase as insolubles increase, suggesting that detritus in these chalks is greatly influenced by reworked, altered, volcanic products rather than siliceous clastics.-from Authors

  10. Dual FIB-SEM 3D imaging and lattice boltzmann modeling of porosimetry and multiphase flow in chalk.

    SciTech Connect

    Rinehart, Alex; Petrusak, Robin; Heath, Jason E.; Dewers, Thomas A.; Yoon, Hongkyu

    2010-12-01

    Mercury intrusion porosimetry (MIP) is an often-applied technique for determining pore throat distributions and seal analysis of fine-grained rocks. Due to closure effects, potential pore collapse, and complex pore network topologies, MIP data interpretation can be ambiguous, and often biased toward smaller pores in the distribution. We apply 3D imaging techniques and lattice-Boltzmann modeling in interpreting MIP data for samples of the Cretaceous Selma Group Chalk. In the Mississippi Interior Salt Basin, the Selma Chalk is the apparent seal for oil and gas fields in the underlying Eutaw Fm., and, where unfractured, the Selma Chalk is one of the regional-scale seals identified by the Southeast Regional Carbon Sequestration Partnership for CO2 injection sites. Dual focused ion - scanning electron beam and laser scanning confocal microscopy methods are used for 3D imaging of nanometer-to-micron scale microcrack and pore distributions in the Selma Chalk. A combination of image analysis software is used to obtain geometric pore body and throat distributions and other topological properties, which are compared to MIP results. 3D data sets of pore-microfracture networks are used in Lattice Boltzmann simulations of drainage (wetting fluid displaced by non-wetting fluid via the Shan-Chen algorithm), which in turn are used to model MIP procedures. Results are used in interpreting MIP results, understanding microfracture-matrix interaction during multiphase flow, and seal analysis for underground CO2 storage.

  11. A multidisciplinary approach to reservoir subdivision of the Maastrichtian chalk in the Dan field, Danish North Sea

    SciTech Connect

    Kristensen, L.; Dons, T.; Schioler, P.

    1995-11-01

    Correlation of wireline log data from the North Sea chalk reservoirs is frequently hampered by rather subtle log patterns in the chalk section due to the apparent monotonous nature of the chalk sediments, which may lead to ambiguous correlations. This study deals with a correlation technique based on an integration of biostratigraphic data, seismic interpretation, and wireline log correlation; this technique aims at producing a consistent reservoir subdivision that honors both the well data and the seismic data. This multidisciplinary approach has been used to subdivide and correlate the Maastrichtian chalk in the Dan field. The biostratigraphic subdivision is based on a new detailed dinoflagellate study of core samples from eight wells. Integrating the biostratigraphic results with three-dimensional seismic data allows recognition of four stratigraphic units within the Maastrichtian, bounded by assumed chronostratigraphic horizons. This subdivision is further refined by adding a seismic horizon and four horizons from wireline log correlations, establishing a total of nine reservoir units. The approximate chronostratigraphic nature of these units provides an improved interpretation of the depositional and structural patterns in this area. The three upper reservoir units pinch out and disappear in a northeasterly direction across the field. We interpret this stratal pattern as reflecting a relative sea level fall or regional basinal subsidence during the latest Maastrichtian, possibly combined with local synsedimentary uplift due to salt tectonics. Isochore maps indicate that the underlying six non-wedging units are unaffected by salt tectonics.

  12. An integrated modelling and multicriteria analysis approach to managing nitrate diffuse pollution: 2. A case study for a chalk catchment in England.

    PubMed

    Koo, B K; O'Connell, P E

    2006-04-01

    The site-specific land use optimisation methodology, suggested by the authors in the first part of this two-part paper, has been applied to the River Kennet catchment at Marlborough, Wiltshire, UK, for a case study. The Marlborough catchment (143 km(2)) is an agriculture-dominated rural area over a deep chalk aquifer that is vulnerable to nitrate pollution from agricultural diffuse sources. For evaluation purposes, the catchment was discretised into a network of 1 kmx1 km grid cells. For each of the arable-land grid cells, seven land use alternatives (four arable-land alternatives and three grassland alternatives) were evaluated for their environmental and economic potential. For environmental evaluation, nitrate leaching rates of land use alternatives were estimated using SHETRAN simulations and groundwater pollution potential was evaluated using the DRASTIC index. For economic evaluation, economic gross margins were estimated using a simple agronomic model based on nitrogen response functions and agricultural land classification grades. In order to see whether the site-specific optimisation is efficient at the catchment scale, land use optimisation was carried out for four optimisation schemes (i.e. using four sets of criterion weights). Consequently, four land use scenarios were generated and the site-specifically optimised land use scenario was evaluated as the best compromise solution between long term nitrate pollution and agronomy at the catchment scale.

  13. Marking petroglyphs with calcite and gypsum-based chalks: Interaction with granite under different simulated conditions and the effectiveness and harmfulness of cleaning methods.

    PubMed

    Pozo-Antonio, J S; Fernández-Rodríguez, S; Rocha, C S A; Carrera, F; Rivas, T

    2017-08-25

    Marking petroglyphs with chalk is a common practice to enhance them for documentation and reproduction. Although this procedure has started to be less frequently used, there is no knowledge about the interaction between the rock engravings nor about the effectiveness achieved by the common cleaning procedures of such markers considering the chalk extraction and the induced damage to the rock. This study evaluates the interaction between two chalks of different composition (calcite and gypsum) and a granite on which the majority of NW Iberian Peninsula-petroglyphs are carved. Granitic samples marked with these chalks were subjected to artificial rain events and high temperatures (700°C) related to fires. After each aging test, chemical and physical modifications on the rock were analysed by means of stereomicroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and colour spectrophotometry. Moreover, the evaluation of the effectiveness and harmfulness of several mechanical and chemical cleaning procedures commonly used in the field of cultural heritage conservation was carried out. Both chalks remained at different extent on the surface after the artificial rain events. Water would promote a different penetration-depth of the chalks into the stone, depending on their solubility. High temperatures led to mineral phase transformations of the chalks influencing the interaction with the rock. Regarding cleaning effectiveness, despite a few chalk remains were found in all the cleanings, chemical methods showed higher effectiveness than mechanical procedures even though some of them leave chemical contamination. Benzalkonium chloride can be considered as the cleaner with the best results to extract both types of chalk on granite. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. An aerial radiological survey of the Oyster Creek Nuclear Power Plant and surrounding area, Forked River, New Jersey. Date of survey: September 18--25, 1992

    SciTech Connect

    Hopkins, H.A.; McCall, K.A.

    1994-05-01

    An aerial radiological survey was conducted over the Oyster Creek Nuclear Power Plant in Forked River, New Jersey, during the period September 18 through September 24, 1992. The survey was conducted at an altitude of 150 feet (46 meters) over a 26-square-mile (67-square-kilometer) area centered on the power station. The purpose of the survey was to document the terrestrial gamma radiation environment of the Oyster Creek Nuclear Power plant and surrounding area. The results of the aerial survey are reported as inferred gamma radiation exposure rates at 1 meter above ground level in the form of a contour map. Outside the plant boundary, exposure rates were found to vary between 4 and 10 microroentgens per hour and were attributed to naturally-occurring uranium, thorium, and radioactive potassium gamma emitters. The aerial data were compared to ground-based benchmark exposure rate measurements and radionuclide assays of soil samples obtained within the survey boundary. The ground-based measurements were found to be in good agreement with those inferred from the aerial measuring system. A previous survey of the power plant was conducted in August 1969 during its initial startup phase. Exposure rates and radioactive isotopes revealed in both surveys were consistent and within normal terrestrial background levels.

  15. Evaluation of calabash chalk effect on femur bone morphometry and mineralization in young wistar rats: A pilot study

    PubMed Central

    Ekong, Moses B; Ekanem, Theresa B; Sunday, Abraham O; Aquaisua, Aquaisua N; Akpanabiatu, Monday I

    2012-01-01

    Background: Calabash chalk, a popularly consumed geophagic material in Nigeria has been reported to contain lead, arsenic, alpha lindane, endrin, and endosulfan 11 among other pollutants. Aim: The continuous exposure of young children to this chalk necessitated this study on the bone morphometry and mineralization in young Wistar rats. Materials and Methods: Fourteen young (weanling) Wistar rats of both sexes weighing 54-72 g were assigned into two groups of seven animals each. Group I served as control, while group II was the test group (TG). 40 mg/ml of C. chalk was administered as suspension to the test animals in group II. Animals in the control group were orally treated with 1ml of distilled water. Administration of the C. chalk in the animals lasted for 28 days, and the animals were sacrificed on day 29, using chloroform anaesthesia. The femur bones were dissected out, cleaned of flesh and sun-dried. The lengths and weights of the femur bones were measured using graphite furnace atomic mass spectrophotometer. Results: Results showed 1.6% decrease in body weight change in the TG, insignificant decreases in the weights and lengths of both the right and left femur bones, and significant decreased (P < 0.0126) organ-somatic index, and femur bones concentrations (mg/l) of zinc, phosphate, carbonate, calcium, sodium, and potassium (P < 0.05). Conclusion: In conclusion, this study showed that C. chalk may alter growth rate, and cause de-mineralization in the femur bone, hence, it may be detrimental to bone growth. PMID:23776822

  16. Conference on the topic: {open_quotes}Exploration and production of petroleum and gas from chalk reservoirs worldwide{close_quotes}

    SciTech Connect

    Kuznetsov, V.G.

    1995-07-01

    More than 170 delegates from 14 countries in Europe, North America, Africa, and Asia took part in a conference on the topic: Exploration and Production of Petroleum and Gas from Chalk Reservoirs Worldwide. The conference was held in Copenhagen, Denmark in September,1994, and was a joint meeting of the American Association of Petroleum Geologists (AAPG), and the European Association of Petroleum Geoscientists and Engineers (EAPG). In addition to the opening remarks, 25 oral and nine poster reports were presented. The topics included chalk deposits as reservoir rocks, the occurrence of chalk deposits worldwide, the North Sea oil and gas fields, and other related topics.

  17. Transport of radionuclides in an unconfined chalk aquifer inferred from U-series disequilibria

    NASA Astrophysics Data System (ADS)

    Hubert, Amélie; Bourdon, Bernard; Pili, Eric; Meynadier, Laure

    2006-11-01

    U-series disequilibria measured in waters and rocks from a chalk aquifer in France have been used as an analog for long-term radionuclide migration. Drill core samples from a range of depths in the vadose zone and in the saturated zone, as well as groundwater samples were analyzed for 238U, 234U, 232Th and 230Th to determine transport mechanisms at the water/rock interface and to quantify parameters controlling the migration of radionuclides. Isotope measurements in rocks were done by TIMS, whereas ( 234U/ 238U) and ( 230Th/ 232Th) activity ratios in water samples were measured by multi-collector-ICP-MS. Both depletion and enrichment in 234U relative to 238U were observed in carbonate rock samples resulting from chemical weathering in the unsaturated zone and calcite precipitation in the zone of water-table oscillation, respectively. The correlation between ( 230Th/ 232Th) activity ratios and 87Sr/ 86Sr ratios found in the chalk samples indicates that thorium is mainly contained in a minor silicate phase whose abundance is variable in chalk samples. Water samples are all characterized by ( 234U/ 238U) > 1 resulting from α-recoil effect of 234Th. Groundwaters are characterized by a more radiogenic signature in 87Sr/ 86Sr than the rocks. Moreover, ( 230Th/ 232Th) activity ratios in the waters are lower than in the rocks, and increase with distance from the water divide, which suggests that Th transport is controlled by colloids formed during water infiltration in the soil. A 1-D transport model has been developed in order to constrain the U-series nuclide transport considering a transient behavior of radionuclides in the aquifer and a time-dependent composition for the solid phase. This model permits a prediction of the time scale of equilibration of the system, and an estimation of parameters such as weathering rate, distribution coefficients and α-recoil fractions. Retardation factors of 10-35 and from 1 × 10 4 to 2 × 10 5 were predicted for U and Th

  18. Nuclear materials

    SciTech Connect

    Not Available

    1992-08-01

    The Department of Energy (DOE) processes plutonium for use in nuclear weapons. This fact sheet responds to your September 6, 1991, request, that we describe the methods and facilities for DOE's plutonium processing. Plutonium, which is used to make nuclear weapons, does not exist in nature and has to be produced. However, DOE no longer produces plutonium for use in nuclear weapons. Instead, DOE processes and recycles the plutonium from retired nuclear weapons and the plutonium that remains as scrap or residue from plutonium processing. This paper reports that DOE recovers plutonium through two basic processes-aqueous and pyrochemical-at four processing sites-Rocky Flats, Savannah River, Hanford, and Los Alamos. However, because of environmental and safety concerns and reductions in nuclear weapons, DOE has closed or may close most of the processing facilities. Only Los Alamos' processing facilities are currently operating.

  19. Study of a conceptual nuclear energy center at Green River, Utah. Power demand, load center assessment and transmission

    SciTech Connect

    Smith, D.R.; Thaik, A.; Pingel, P.

    1982-02-01

    This document constitutes a segment of a feasibility study investigating the ramification of constructing a nuclear energy center in an arid western region. In this phase of the study. The projected power demands and load center locations were reviewed and assessed. Alternative transmission systems were analysed and a conceptual transmission for bulk power transportation is proposed with potential line routes. Environmental impacts of the proposed transmission were also identified.

  20. HT to HTO conversion and field experiments near Darlington Nuclear Power Generating Station (DNPGS) site.

    PubMed

    Kim, S B; Stuart, M; Bredlaw, M; Festarini, A; Beaton, D

    2014-06-01

    The Canadian input parameters related to tritiated hydrogen gas (HT) used in tritium dose models are currently based on experiments performed at the Chalk River Laboratories (CRL) site in 1986, 1987 and 1994. There is uncertainty in how well other sites experiencing atmospheric HT releases are represented by these data. In order to address this uncertainty, HT to HTO conversion factors were evaluated at different locations near the Darlington Nuclear Power Generating Station (DNPGS) site using various experimental approaches. These were D2 gas exposure chamber experiments, atmospheric tritium measurements, and HTO and OBT measurements in vegetation and soil. In addition to these field experiments, chamber experiments were conducted using HT gas on field soil samples. The suggested Canadian input parameters for atmospheric tritium releases estimate the total fraction of HT oxidized in air and in soil, at the site, to be up to a maximum of 2.4%. Based on the more limited data obtained near DNPGS in early spring, this fraction would likely be closer to 0.5%. The result suggests that current parameters provide a conservative estimate for the DNPGS site.

  1. Italo-Swiss "Chalk and blackboard interactive 2-day workshop"-participants feedback.

    PubMed

    Camozzi, Pietro; Faré, Pietro B; Lavagno, Camilla; Milani, Gregorio P; Fossali, Emilio F; Bianchetti, Mario G; Lava, Sebastiano A G

    2015-08-20

    Ten "chalk and blackboard interactive workshops" have taken place between 2011 and 2015 in Southern Switzerland or Italy. Students, residents and expert pediatricians meet during 2 days and discuss 10-15 cases. Pediatricians promote reasoning, provide supporting information and correct statements. Emphasis is placed on history taking and examination, and on all participants being involved in a stimulating atmosphere. Thirty-seven participants were asked, ≥3 months after workshop-completion, to evaluate the workshop and a recent teaching session. Thirty answered and scored the workshop as excellent (N = 24) or above average (N = 6). The scores assigned to the workshop were higher (P < 0.001) than those assigned to the lecture-based teaching.

  2. Campanian ammonites from the Upper Cretaceous Gober Chalk of Lamar County, Texas

    USGS Publications Warehouse

    Cobban, W.A.; Kennedy, W.J.

    1992-01-01

    The Roxton Limestone Member at the top of the Gober Chalk in northeast Texas yields a rich fauna, dominated by Baculites haresi Reeside, 1927, and Inoceramus balticus Boehm, 1909, with sparse occurrences of pachydiscus cf. P. paulsoni (Young, 1963), Anapachydiscus sp.juv., Placenticeras placenta (DeKay, 1828), Hoplitoplacenticeras aff. H. plasticum (Paulcke, 1907), Menabites (Delawarella) delawarensis (Morton, 1830), M.(D.) danei (Young, 1963), M.(D.) aff. M.(D.) vanuxemi (Morton, 1830), Submortoniceras vandalinaense Young, 1963, Submortoniceras sp., Eubostrychoceras sp., and Scaphites hippocrepis (DeKay, 1828) III. The presence of S. hippocrepis III suggests a late early Campanian age assignment for the fauna. The assemblage includes species known from the Western Interior, Gulf Coast, Atlantic seaboard, and western Europe. -Authors

  3. Multi isotopic tools to understand selenium origins in groundwaters of the Chalk aquifer in Northern France

    NASA Astrophysics Data System (ADS)

    Cary, Lise; Gourcy, Laurence; Benabderraziq, Hind; Elkhattabi, Jamal; Laurent, Alexandra; Négrel, Philippe

    2013-04-01

    Four field wells exploiting the Chalk aquifer supply Lille city in water. The little catchment area is submitted to quantitative and qualitative pressure from industrial, urban and agriculture origins. Selenium (Se) concentrations are often higher than EU standards (0.12 µmol.L-1) for potable drinking water and can reach 0.4 μmol.L-1 leading to exploitation restrictions. An integrated study was settled to determine the water sources and dynamics of elements, with a focus on Se, with the goal of managing both water quality and quantity. After a large chemical characterisation of the system, a monthly sampling campaign was held in 2012 in four wells and in the close Deûle channel. In situ physical and chemical parameters, chemical analysis of major and trace elements with a special focus on redox-sensitive elements including SeIV, SeVI, FeII, stable water isotopes (δ18O, δ2H) and δ34S and δ18O of sulphates measures were undertaken. The chemical composition of solids sampled at various depths at vicinity of the four wells was analysed. Se concentrations in groundwaters and in the solid phase vary significantly. In the northern part of the Ansereuilles north of the Deûle channel, where the highest Se concentrations in solids was found in a 13 m alluvial clay deposit above the chalk, a first main type of waters can be defined with the variable and locally highest Se concentrations (0.19 to 0.4 µmol.L-1), relatively high and stable sulphate concentrations (2.5 µmol/L), no nitrates, dissolved Fe and Mn, negative δ34S (around -20 ‰) and δ18O typical of evaporated waters. A second main type of waters can be described at Houplin, south of the Deûle channel, where the geological profile show less than 1 mg/kg of Se, with intermediate Se concentrations (0.1 to 0.2 µmol/L), variable nitrate concentrations (0.4 to 1.2 mmol/L), not quantified dissolved Fe and Mn, sulphate concentrations close to 1.5 mmol/L, variable negative δ34S (-8 to -24 ‰) and δ18O in the

  4. Tracking selenium behaviour in chalk aquifer (northern France): Sr and 34S-sulphates isotopes constraints.

    NASA Astrophysics Data System (ADS)

    Cary, Lise; Benabderraziq, Hind; Elkhattabi, Jamal; Parmentier, Marc; Gourcy, Laurence; Négrel, Philippe

    2014-05-01

    Groundwaters in parts of the Paris Basin (France) are facing increasing selenium (Se) contents that can exceed the drinking water limit of 10 μg/L according to the European Framework Directive in the field of water policy (2000/60/EC). To better understand the groundwater origins and the selenium dynamics, the water chemistry of the Chalk aquifer supplying drinkable water to Lille city was studied. This area is submitted to quantitative and qualitative pressure from industrial, urban and agriculture origins. An integrated study was settled to determine the water sources and dynamics of elements, with a focus on Se. After a large chemical characterisation of the groundwater chemistry in the four field wells, a monthly monitoring was held in four wells and in the Deûle channel. Chemical analysis of major and trace elements, stable isotopes (δ18O, δ2H), strontium isotopes, and δ34S and δ18O of sulphates were realised. The chemical composition of solids sampled at various depths at vicinity of the four wells was also analysed. The specific geochemical signature of groundwater as revealed by Sr isotopes, in addition to element concentrations ratios like Mg/Sr and Se/Sr, highlighted mixture of three main groundwaters bodies: (1) the upstream groundwaters in the recharge area with the most radiogenic 87Sr/86Sr isotopic signature; (2) the confined groundwaters with high Sr concentrations due to water-rock interactions and the lowest 87Sr/86Sr isotopic signature close to the one of the chalk in Paris and London basins; (3) the Se-rich formations of Tertiary and Quaternary. The contents of Se, mainly present as SeV I (and locally as SeIV ), displayed spatial and temporal disparities that can be explained by geological and hydrogeological conditions. Se-rich clayed sediments originating from the dismantling of Se-rich tertiary formations (i.e. Ypresian) overlay the chalk formation and can be found in saturated conditions depending of the water table level. Oxidation of

  5. Water temperatures within spawning beds in two chalk streams and implications for salmonid egg development

    NASA Astrophysics Data System (ADS)

    Acornley, R. M.

    1999-02-01

    Water temperatures within brown trout (Salmo trutta L.) spawning gravels were measured in two Hampshire chalk streams from October 1995 to April 1996 inclusive. During the winter, mean intra-gravel water temperatures were higher than those in the stream, and increased with depth in the gravel bed. The amplitude of diel fluctuations in water temperature decreased with depth in the gravel bed, although diel fluctuations were still evident at a depth of 30 cm. Differences in intra-gravel temperature gradients between the two study sites were attributed to differences in the amplitude of stream water temperature fluctuations and there was no evidence that either of the study sites were located in zones of upwelling groundwater. Published equations are used to predict, from temperature, the timing of important stages in the development of brown trout embryos (eyeing, hatching and emergence) for eggs spawned in the autumn and winter and buried at different depths in the gravel bed.

  6. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of soil analysis on NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL will attempt to determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of the analytical procedure of NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL can determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Space Life Sciences Lab

    NASA Image and Video Library

    2003-10-09

    The Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL), is a state-of-the-art facility built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor is the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  9. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of soil analysis on NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL will attempt to determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  10. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of the analytical procedure of NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL can determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  11. e-Learning - Physics Labs

    NASA Astrophysics Data System (ADS)

    Mohottala, Hashini

    2014-03-01

    The general student population enrolled in any college level class is highly diverse. An increasing number of ``nontraditional'' students return to college and most of these students follow distance learning degree programs while engaging in their other commitments, work and family. However, those students tend to avoid taking science courses with labs, mostly because of the incapability of remotely completing the lab components in such courses. In order to address this issue, we have come across a method where introductory level physics labs can be taught remotely. In this process a lab kit with the critical lab components that can be easily accessible are conveniently packed into a box and distributed among students at the beginning of the semester. Once the students are given the apparatus they perform the experiments at home and gather data All communications with reference to the lab was done through an interactive user-friendly webpage - Wikispaces (WikiS). Students who create pages on WikiS can submit their lab write-ups, embed videos of the experiments they perform, post pictures and direct questions to the lab instructor. The students who are enrolled in the same lab can interact with each other through WikiS to discuss labs and even get assistance.

  12. Impact of microbial activity on the hydraulic properties of fractured chalk.

    PubMed

    Arnon, Shai; Adar, Eilon; Ronen, Zeev; Yakirevich, Alexander; Nativ, Ronit

    2005-02-01

    The impact of microbial activity on fractured chalk transmissivity was investigated on a laboratory scale. Long-term experiments were conducted on six fractured chalk cores (20 cm diameter, 23-44 cm long) containing a single natural fracture embedded in a porous matrix. Biodegradation experiments were conducted under various conditions, including several substrate and oxygen concentrations and flow rates. 2,4,6-Tribromophenol (TBP) was used as a model contaminant (substrate). TBP biodegradation efficiency depended mainly on the amount of oxygen. However, under constant oxygen concentration at the core inlet, elevating the flow rates increased the removal rate of TBP. Transmissivity reduction was clearly related to TBP removal rate, following an initial slow decline and a further sharp decrease with time. The fracture's transmissivity was reduced by as much as 97% relative to the initial value, with no leveling off of the clogging process. For the most extreme cases, reductions of 262 and 157 microm in the equivalent hydraulic apertures were recorded for fractures with initial apertures of 495 and 207 microm, respectively. The reductions in fracture transmissivity occurred primarily because of clogging by bacterial cells and extracellular polymeric substances (EPS) produced by the bacteria. Most of the biodegradation activity was concentrated near the fracture inlet, where the most suitable biodegradation conditions (nutrients and oxygen) prevailed, suggesting that the clogging had occurred in that vicinity. The clogging must have changed the structure of the fracture void, thereby reducing the active volume participating in flow and transport processes. This phenomenon caused accelerated transport of non-reactive tracers and doubled the fracture's dispersivity under constant flow rates.

  13. Anomalous magnetization in the Austin Chalk: implications for magnetic studies in rocks and sediments

    SciTech Connect

    Ellwood, B.B.; Balsam, W.L.

    1985-01-01

    Same day sampling and magnetic measurement of a one meter thick bed in a new road cut of the Upper Cretaceous Austin Chalk (northeastern Texas) has yielded a zone of anomalous magnetic behavior. Initial measurement of the anisotropy of magnetic susceptibility (AMS) indicated unusually high anisotropies and low bulk susceptibilities characteristic of a magnetocrystalline anisotropy which might be expected for the mineral siderite. Natural remanent magnetization (NRM) moments for these samples were low and directions were typical for samples which had acquired a normal geomagnetic field overprint at the site. Remeasurement of the NRM 3 days later yielded an increase in moment to >1 x 10/sup -3/ A/m for some samples and a direction parallel to the laboratory field. Isothermal remanent magnetization (IRM) of these samples indicates saturation at low induction values (<100 mT). AMS remeasurement over a period of weeks revealed a steady decrease in the anisotropy magnitudes and a change in direction. All of these results are consistent with the initial presence of siderite in the Austin Chalk samples. After sampling, exposure to the air, and subsequent oxidation in the laboratory, the siderite appears to have altered to ..gamma..Fe/sub 2/O/sub 3/ (maghemite), increasing the magnetic moment and changing NRM and AMS directions in these samples. It is predicted that changes will reflect the continued conversion from the less stable ..gamma..Fe/sub 2/O/sub 3/ to ..cap alpha..Fe/sub 2/O/sub 3/ (hematite). Evaluation of this possibility is currently in progress.

  14. Influences of space, soil, nematodes and plants on microbial community composition of chalk grassland soils.

    PubMed

    Yergeau, Etienne; Bezemer, T Martijn; Hedlund, Katarina; Mortimer, Simon R; Kowalchuk, George A; Van Der Putten, Wim H

    2010-08-01

    Microbial communities respond to a variety of environmental factors related to resources (e.g. plant and soil organic matter), habitat (e.g. soil characteristics) and predation (e.g. nematodes, protozoa and viruses). However, the relative contribution of these factors on microbial community composition is poorly understood. Here, we sampled soils from 30 chalk grassland fields located in three different chalk hill ridges of Southern England, using a spatially explicit sampling scheme. We assessed microbial communities via phospholipid fatty acid (PLFA) analyses and PCR-denaturing gradient gel electrophoresis (DGGE) and measured soil characteristics, as well as nematode and plant community composition. The relative influences of space, soil, vegetation and nematodes on soil microorganisms were contrasted using variation partitioning and path analysis. Results indicate that soil characteristics and plant community composition, representing habitat and resources, shape soil microbial community composition, whereas the influence of nematodes, a potential predation factor, appears to be relatively small. Spatial variation in microbial community structure was detected at broad (between fields) and fine (within fields) scales, suggesting that microbial communities exhibit biogeographic patterns at different scales. Although our analysis included several relevant explanatory data sets, a large part of the variation in microbial communities remained unexplained (up to 92% in some analyses). However, in several analyses, significant parts of the variation in microbial community structure could be explained. The results of this study contribute to our understanding of the relative importance of different environmental and spatial factors in driving the composition of soil-borne microbial communities. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.

  15. Physics with CLAS at Jefferson Lab

    SciTech Connect

    Michel Garcon

    2006-05-22

    The CLAS collaboration at Jefferson Lab is engaged in a wide range of experiments, covering mostly meson and baryon spectroscopy, nucleon structure through elastic and deep inelastic scattering, nuclear transparency and nucleon correlations in nuclei. These experiments use the CEBAF highly polarized electron beam, or the secondary tagged photon beam, together with the CLAS detector (CEBAF Large Acceptance Spectrometer), to which specific experiments bring additional equipment. In this talk, examples of recent results on subjects mentioned hereabove will be given, with special emphasis on nucleon structure. A short description of the planned upgrade from CLAS to CLAS12 is presented.

  16. Quark Hadron Duality - Recent Jefferson Lab Results

    SciTech Connect

    Niculescu, Maria Ioana

    2016-08-01

    The duality between the partonic and hadronic descriptions of electron--nucleon scattering is a remarkable feature of nuclear interactions. When averaged over appropriate energy intervals the cross section at low energy which is dominated by nucleon resonances resembles the smooth behavior expected from perturbative QCD. Recent Jefferson Lab results indicate that quark-hadron duality is present in a variety of observables, not just the proton F2 structure function. An overview of recent results, especially local quark-hadron duality on the neutron, are presented here.

  17. Guide to Savannah River Laboratory Analytical Services Group

    SciTech Connect

    Not Available

    1990-04-01

    The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary.

  18. Guide to Savannah River Laboratory Analytical Services Group

    SciTech Connect

    Not Available

    1990-04-01

    The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary.

  19. CHARACTERIZATION OF INDIVIDUAL CHEMICAL REACTIONS CONSUMING ACID DURING NUCLEAR WASTE PROCESSING AT THE SAVANNAH RIVER SITE - 136B

    SciTech Connect

    Koopman, D.; Pickenheim, B.; Lambert, D.; Newell, J.; Stone, M.

    2009-09-02

    Conversion of legacy radioactive high-level waste at the Savannah River Site into a stable glass waste form involves a chemical pretreatment process to prepare the waste for vitrification. Waste slurry is treated with nitric and formic acids to achieve certain goals. The total quantity of acid added to a batch of waste slurry is constrained by the catalytic activity of trace noble metal fission products in the waste that can convert formic acid into hydrogen gas at many hundreds of times the radiolytic hydrogen generation rate. A large block of experimental process simulations were performed to characterize the chemical reactions that consume acid prior to hydrogen generation. The analysis led to a new equation for predicting the quantity of acid required to process a given volume of waste slurry.

  20. Nuclear waste-form risk assessment for US Defense waste at Savannah River Plant. Annual report FY 1981

    SciTech Connect

    Cheung, H.; Edwards, L.L.; Harvey, T.F.; Jackson, D.D.; Revelli, M.A.

    1981-12-01

    Savannah River Plant has been supporting the Lawrence Livermore National Laboratory in its present effort to perform risk assessments of alternative waste forms for defense waste. This effort relates to choosing a suitable combination of solid form and geologic medium on the basis of risk of exposure to future generations; therefore, the focus is on post-closure considerations of deep geologic repositories. The waste forms being investigated include borosilicate glass, SYNROC, and others. Geologic media under consideration are bedded salt, basalt, and tuff. The results of our work during FY 1981 are presented in this, our second annual report. The two complementary tasks that comprise our program, analysis of waste-form dissolution and risk assessment, are described.

  1. The intestinal LABs.

    PubMed

    Vaughan, Elaine E; de Vries, Maaike C; Zoetendal, Erwin G; Ben-Amor, Kaouther; Akkermans, Antoon D L; de Vos, Willem M

    2002-08-01

    The complete gastrointestinal (GI) tract of humans is colonised soon after birth by a myriad of microbial species with a characteristic distribution depending on the location. GI-tract ecology has been experiencing a revival due to the development of molecular techniques, especially those based on 16S RNA (zRNA) genes. A richer ecosystem than previously imagined of novel species is being discovered that is significantly influenced by our host genotype. Special attention has been focused on the bifidobacteria and the lactic acid bacterial (LAB) populations, both those that are naturally present within this complex ecosystem and those that are ingested as probiotics in functional foods. Overall this interest stems from a increasing awareness of interplay between microflora, diet and the health of the host, and is further stimulated by an increasing incidence of gastrointestinal illnesses, and atopy. Substantial documentation of benefits to host health has especially distinguished the LAB for multidisciplinary research aimed to determine the molecular mechanisms involved. Recent advances in molecular technologies, including high-throughput genomics-based approaches, can significantly advance our understanding of the microbe--diet--host interactions and offer valuable information for design and application of health-targeted microbes.

  2. Inexpensive DAQ based physics labs

    NASA Astrophysics Data System (ADS)

    Lewis, Benjamin; Clark, Shane

    2015-11-01

    Quality Data Acquisition (DAQ) based physics labs can be designed using microcontrollers and very low cost sensors with minimal lab equipment. A prototype device with several sensors and documentation for a number of DAQ-based labs is showcased. The device connects to a computer through Bluetooth and uses a simple interface to control the DAQ and display real time graphs, storing the data in .txt and .xls formats. A full device including a larger number of sensors combined with software interface and detailed documentation would provide a high quality physics lab education for minimal cost, for instance in high schools lacking lab equipment or students taking online classes. An entire semester’s lab course could be conducted using a single device with a manufacturing cost of under $20.

  3. An Electron-Ion Collider at Jefferson lab

    SciTech Connect

    A.W. Thomas

    2009-10-01

    Long term plans for the investigation of the quark and gluon structure of matter have for some time focussed on the possibility of an electron-ion collider, with the nuclear physics communities associated with JLab and BNL being particularly active. We briefly outline the current thinking on this subject at Jefferson lab.

  4. How plate tectonics is recorded in chalk deposits along the eastern English Channel in Normandy (France) and Sussex (UK)

    NASA Astrophysics Data System (ADS)

    Duperret, Anne; Vandycke, Sara; Mortimore, Rory N.; Genter, Albert

    2012-12-01

    Intra-plate stresses that occurred in the Anglo-Paris Basin and English Channel during Upper Cretaceous and Cenozoic times are a consequence of the convergence between Eurasia and Africa and the opening of the North Atlantic area. This geodynamic re-organisation is recorded on each side of the English Channel, with the emergence of regional structures such as the the Weald-Artois anticline and the reactivation of large-scale strike-slip faults. We analyse the Anglo-Paris Basin Chalk fracture system, on each side of the eastern English Channel, using a set of 1600 meso-scale fractures data collected on coastal chalk cliffs in Normandy (NW France) and Sussex (UK). Meso-scale fracture system is precisely dated using chalk lithostratigraphy correlations within the basin. Moreover, an inversion method is used on fault slip data to evidence a paleostress chronology in the Anglo-Paris Basin. Three main Upper Cretaceous extensive events, characterized by normal faults and jointing are recorded in Normandy and two Cenozoic compressive and extensive events with strike-slip and normal faults appear in Sussex. Paleostress records vary on each part of the eastern English Channel. The meso-scale fracture system is thus used to better define the type of relationship between meso-scale and large-scale brittle deformation in the Chalk during Meso-Cenozoic. A first NE-SW extension is recorded in Normandy in relation with local anticlines structures and related to the Lower Rhine graben opening. A second event is a WNW-ESE extension of local origin in relation with the subsidence axis of the Paris Basin. The third event is a NNE-SSW extension, well marked in Normandy and related to the activation of E-W normal faults in the western approaches of the English Channel. This event is also recorded in Sussex and reactivates locally older fractures in strike-slip. The Oligocene N-S compression/E-W extension related to the Pyrenean tectonics and the last E-W extension relative to the North

  5. ERLN Technical Support for Labs

    EPA Pesticide Factsheets

    The Environmental Response Laboratory Network provides policies and guidance on lab and data requirements, Standardized Analytical Methods, and technical support for water and radiological sampling and analysis

  6. Lab at Home: Hardware Kits for a Digital Design Lab

    ERIC Educational Resources Information Center

    Oliver, J. P.; Haim, F.

    2009-01-01

    An innovative laboratory methodology for an introductory digital design course is presented. Instead of having traditional lab experiences, where students have to come to school classrooms, a "lab at home" concept is proposed. Students perform real experiments in their own homes, using hardware kits specially developed for this purpose. They…

  7. Propulsion Systems Lab

    NASA Image and Video Library

    2015-04-14

    NASA Glenn’s Propulsion Systems Lab (PSL) is conducting research to characterize ice crystal clouds that can create a hazard to aircraft engines in certain conditions. With specialized equipment, scientists can create a simulated ice crystal cloud with the set of bars in the back spraying out a mist. The red area includes lasers, which measure the intensity of the cloud and a series of probes to measure everything from humidity to air pressure. The isokinetic probe (in gold) samples particles and the robotic arm (in orange) has a test tube on the end that catches ice particles for further measuring. NASA Glenn’s PSL is the only place in the world which can create these kind of ice crystal cloud conditions.

  8. Alternatives to Traditional Labs: a Discovery Lab Based on Analogy

    NASA Astrophysics Data System (ADS)

    Liff, Mark I.

    2006-12-01

    In search for alternatives to traditional labs, it is worthwhile to turn to the creativity research. Analogy is believed by many to be at the heart of creativity. A discovery lab that requires use of analogy had been developed. A basis of the lab is a re-discovery of Gough-Joule effect of contraction of stretched rubber upon heating. The difficulties of designing an analogybased lab are discussed. The students' reaction to the unusual lab is analyzed. The data suggest that the students need to be provided with the base for analogy use. They also need to be given directions for the search of solution by changing and modification of analogies, and weeding out the misleading ones and selectively retaining productive analogies. This study shows that thought processes of divergent nature--commonly accessible only to experts--can be employed under the discussed conditions by novices as well.

  9. Tracer Sampling In The Arctic From The Nuclear Submarine USS L. Mendel Rivers During SCICEX 2000: Evidence Of Eddies

    NASA Astrophysics Data System (ADS)

    Kadko, D. C.; Aagaard, K.

    2006-12-01

    Observations suggest that the central Arctic Ocean is surprisingly energetic and variable, given the weak mean flow and the very strong halocline, which isolates the surface from the deeper ocean. One source of variability is numerous, generally anticyclonic eddies, many of which are centered in the halocline and likely generated within the boundary current. These and other eddies may be an important means of transporting properties in regions of weak mean flow, since they are found far from their origin, show anomalous water properties, and have a life time of years, mixing only slowly with ambient waters. Tracers additional to temperature and salinity will likely prove useful in identifying eddy sources and ages. Here we report radium isotope, temperature, and salinity data obtained from the USS L. Mendel Rivers - PACSUBICEX 3-00 SCICEX Accommodation cruise in October, 2000. The radium activity ratios are linked to shelf sources, and provide estimates of time elapsed since the waters left the shelf. The generally decreasing 228Ra/226Ra ratio in the halocline observed across the Canada Basin from Barrow to the North Pole is consistent with distance from Pacific shelf sources. Additionally, isolated anomalously high 228Ra/226Ra ratios within both the Canada and Eurasian basins suggest water parcels that have been rapidly (relative to the 5.77 year 228Ra half-life) transported from the shelves into the interior. The density field indicates that eddies are the means of this efficient transport of shelf properties into the central Arctic Ocean.

  10. Nuclear waste form risk assessment for US defense waste at Savannah River Plant. Annual report fiscal year 1980

    SciTech Connect

    Cheung, H.; Jackson, D.D.; Revelli, M.A.

    1981-07-01

    Waste form dissolution studies and preliminary performance analyses were carried out to contribute a part of the data needed for the selection of a waste form for the disposal of Savannah River Plant defense waste in a deep geologic repository. The first portion of this work provides descriptions of the chemical interactions between the waste form and the geologic environment. We reviewed critically the dissolution/leaching data for borosilicate glass and SYNROC. Both chemical kinetic and thermodynamic models were developed to describe the dissolution process of these candidate waste forms so as to establish a fundamental basis for interpretation of experimental data and to provide directions for future experiments. The complementary second portion of this work is an assessment of the impacts of alternate waste forms upon the consequences of disposal in various proposed geological media. Employing systems analysis methodology, we began to evaluate the performance of a generic waste form for the case of a high risk scenario for a bedded salt repository. Results of sensitivity analysis, uncertainty analyses, and sensitivity to uncertainty analysis are presented.

  11. Palaeoclimatic changes during the Upper Cretaceous of eastern Denmark: a study based on the Stevns-2 chalk core

    NASA Astrophysics Data System (ADS)

    Boussaha, M.; Stemmerik, L.; Thibault, N.

    2013-12-01

    The Stevns-2 core located in eastern Denmark penetrated close to 350 m of upper Campanian-Maastrichtian sediments of the upper Chalk Group (Stemmerik et al., 2006). The calcareous nannofossil biozonation spans the time interval from the UC16aBP from the upper Campanian to the NNT1 in the lowermost Danian. Carbon and Oxygen isotopes trends records climatic events occurring in the upper Cretaceous: (1) the Late Campanian warm climatic optimum, (2) the early Maastrichtian cooling event, (3) the mid-Maastrichtian warming event, and (4) the late Maastrichtian cooling event, also observed in the nearby Stevns-1 core (Thibault et al., 2011) . These climatic variations match closely those observed in the nearby Stevns-1 core and in the Atlantic, Pacific and Tethyan realms (Thibault & GARDIN, 2006; Thibault et al., 2011). Changes occurring in the number of observed Inoceramids prisms per meter of core section, in the abundance of calcareous nannofossils and in the visible trace fossils abundances seem to be linked to climatic changes as expressed in the δ18O of the bulk sediment. In addition to the sedimentological data show that the distribution of facies through time from: (1) cyclic marl alternating with mudstone-wackestone chalk and conglomerates, to (2) bioturbated white mudstone and wackestone chalk, then to (3) flint alternating with mudstone and wackestone chalk, ending with (5) bryozoans wackestone and packstone, and the sedimentation rate changes varying from 1.4 cm/kyr to 13.4 cm/kyr. Here we show how changes in the sedimentology of the chalk and abundances of different fossil group are influenced by global and regional mechanisms. Isotopic results mainly reflect global paleoclimatic changes, whereas the sedimentological record is mostly influenced by (1) local variations in paleoproductivity, (2) deep-water paleocurrents influencing the chalk deposition and the shape of the sea-floor, (3) and (4) the geodynamic activity and paleotopography of the Late

  12. Initial flux of sediment-associated radiocesium to the ocean from the largest river impacted by Fukushima Daiichi Nuclear Power Plant

    PubMed Central

    Yamashiki, Yosuke; Onda, Yuichi; Smith, Hugh G.; Blake, William H.; Wakahara, Taeko; Igarashi, Yasuhito; Matsuura, Yuki; Yoshimura, Kazuya

    2014-01-01

    This study aimed to quantify the flux of radiocesium in the Abukuma Basin (5,172 km2), the largest river system affected by fallout from the Fukushima Daiichi Nuclear Power Plant (FDNPP) event. In the period from 10 August 2011 to 11 May 2012 an estimated 84 to 92% of the total radiocesium transported in the basin's fluvial system was carried in particulate form. During this monitoring period Typhoon Roke (September 2011) was observed to induce a significant and temporally punctuated redistribution of radiocesium. The storm-mobilised radiocesium was an estimated 6.18 Terabecquerels corresponding to 61.4% of the total load delivered to the coastal zone during the observation period. The total flux of radiocesium into the Pacific Ocean estimated at the outlet station (basin area 5,172 km2) was 5.34 TBq for 137Cs, and 4.74 TBq for 134Cs, corresponding to 1.13% of the total estimated radiocesium fallout over the basin catchment (890 TBq). This was equivalent to the estimated amount of direct leakage from FDNPP to the ocean during June 2011 to September 2012 of 17 TBq and the Level 3 Scale Leakage on 21August 2013 (24 TBq). PMID:24429978

  13. Environmental parameters of the Tennessee River in Alabama. 2: Physical, chemical, and biological parameters. [biological and chemical effects of thermal pollution from nuclear power plants on water quality

    NASA Technical Reports Server (NTRS)

    Rosing, L. M.

    1976-01-01

    Physical, chemical and biological water quality data from five sites in the Tennessee River, two in Guntersville Reservoir and three in Wheeler Reservoir were correlated with climatological data for three annual cycles. Two of the annual cycles are for the years prior to the Browns Ferry Nuclear Power Plant operations and one is for the first 14 months of Plant operations. A comparison of the results of the annual cycles indicates that two distinct physical conditions in the reservoirs occur, one during the warm months when the reservoirs are at capacity and one during the colder winter months when the reservoirs have been drawn-down for water storage during the rainy months and for weed control. The wide variations of physical and chemical parameters to which the biological organisms are subjected on an annual basis control the biological organisms and their population levels. A comparison of the parameters of the site below the Power plant indicates that the heated effluent from the plant operating with two of the three reactors has not had any effect on the organisms at this site. Recommendations given include the development of prediction mathematical models (statistical analysis) for the physical and chemical parameters under specific climatological conditions which affect biological organisms. Tabulated data of chemical analysis of water and organism populations studied is given.

  14. 13C Nuclear Magnetic Resonance and Electron Paramagnetic Spectroscopic Comparison of Hydrophobic Acid, Transphilic Acid, and Reverse Osmosis May 2012 Isolates of Organic Matter from the Suwannee River

    PubMed Central

    Nwosu, Ugwumsinachi G.; Cook, Robert L.

    2015-01-01

    Abstract Dissolved organic matter (DOM) is found in most natural waters at concentrations low enough to make DOM isolation methodologies critical to full analytical characterization and preservation. During the last few decades, two major protocols have been developed for the extraction of DOM isolates from natural waters. These methods utilize XAD resins and reverse osmosis (RO). In this work, the hydrophobic acid (May 2012 HPOA) and transphilic acid (May 2012 TPIA) isolates from XAD-8 and XAD-4 resins, respectively, were compared with the RO (May 2012 RO) natural organic matter isolate of the Suwannee River water using 13C nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies. 13C NMR analysis showed that the May 2012 RO isolate could be viewed as a hybrid of the more hydrophobic May 2012 HPOA isolate and more hydrophilic May 2012 TPIA isolate. The May 2012 HPOA isolate is shown to be higher in alkyl and aromatic moieties, while the May 2012 TPIA isolate is higher in O-alkyl moieties. EPR analysis revealed that the May 2012 TPIA and, in particular, May 2012 HPOA isolates had higher radical concentrations than the May 2012 RO isolate. It is postulated that some of the radical concentrations came from the use of base during the isolation procedures, especially in the XAD method. PMID:25565761

  15. (13)C Nuclear Magnetic Resonance and Electron Paramagnetic Spectroscopic Comparison of Hydrophobic Acid, Transphilic Acid, and Reverse Osmosis May 2012 Isolates of Organic Matter from the Suwannee River.

    PubMed

    Nwosu, Ugwumsinachi G; Cook, Robert L

    2015-01-01

    Dissolved organic matter (DOM) is found in most natural waters at concentrations low enough to make DOM isolation methodologies critical to full analytical characterization and preservation. During the last few decades, two major protocols have been developed for the extraction of DOM isolates from natural waters. These methods utilize XAD resins and reverse osmosis (RO). In this work, the hydrophobic acid (May 2012 HPOA) and transphilic acid (May 2012 TPIA) isolates from XAD-8 and XAD-4 resins, respectively, were compared with the RO (May 2012 RO) natural organic matter isolate of the Suwannee River water using (13)C nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies. (13)C NMR analysis showed that the May 2012 RO isolate could be viewed as a hybrid of the more hydrophobic May 2012 HPOA isolate and more hydrophilic May 2012 TPIA isolate. The May 2012 HPOA isolate is shown to be higher in alkyl and aromatic moieties, while the May 2012 TPIA isolate is higher in O-alkyl moieties. EPR analysis revealed that the May 2012 TPIA and, in particular, May 2012 HPOA isolates had higher radical concentrations than the May 2012 RO isolate. It is postulated that some of the radical concentrations came from the use of base during the isolation procedures, especially in the XAD method.

  16. Initial flux of sediment-associated radiocesium to the ocean from the largest river impacted by Fukushima Daiichi Nuclear Power Plant.

    PubMed

    Yamashiki, Yosuke; Onda, Yuichi; Smith, Hugh G; Blake, William H; Wakahara, Taeko; Igarashi, Yasuhito; Matsuura, Yuki; Yoshimura, Kazuya

    2014-01-16

    This study aimed to quantify the flux of radiocesium in the Abukuma Basin (5,172 km(2)), the largest river system affected by fallout from the Fukushima Daiichi Nuclear Power Plant (FDNPP) event. In the period from 10 August 2011 to 11 May 2012 an estimated 84 to 92% of the total radiocesium transported in the basin's fluvial system was carried in particulate form. During this monitoring period Typhoon Roke (September 2011) was observed to induce a significant and temporally punctuated redistribution of radiocesium. The storm-mobilised radiocesium was an estimated 6.18 Terabecquerels corresponding to 61.4% of the total load delivered to the coastal zone during the observation period. The total flux of radiocesium into the Pacific Ocean estimated at the outlet station (basin area 5,172 km(2)) was 5.34 TBq for (137)Cs, and 4.74 TBq for (134)Cs, corresponding to 1.13% of the total estimated radiocesium fallout over the basin catchment (890 TBq). This was equivalent to the estimated amount of direct leakage from FDNPP to the ocean during June 2011 to September 2012 of 17 TBq and the Level 3 Scale Leakage on 21 August 2013 (24 TBq).

  17. Physics Labs with Flavor II

    ERIC Educational Resources Information Center

    Agrest, Mikhail M.

    2011-01-01

    This paper was inspired by the numerous requests from "TPT" readers to expand the number of examples of "recurrent study" lab exercises described in my previous paper "Physics Labs with Flavor." I recommend that readers examine it first in order to better understand this one as my attempt here is to be brief. In that paper, one can find details…

  18. Physics Labs with Flavor II

    ERIC Educational Resources Information Center

    Agrest, Mikhail M.

    2011-01-01

    This paper was inspired by the numerous requests from "TPT" readers to expand the number of examples of "recurrent study" lab exercises described in my previous paper "Physics Labs with Flavor." I recommend that readers examine it first in order to better understand this one as my attempt here is to be brief. In that paper, one can find details…

  19. Planning an Effective Math Lab.

    ERIC Educational Resources Information Center

    Brown, Donald E.

    In order for a remedial or supplemental mathematics laboratory program to be successful, several important elements must be present. Administrative support of the philosophy of the lab is essential before a sufficiently flexible budget will be provided. Student oriented personnel are the single most important factor in the success of the math lab.…

  20. TQM in a Computer Lab.

    ERIC Educational Resources Information Center

    Swanson, Dewey A.; Phillips, Julie A.

    At the Purdue University School of Technology (PST) at Columbus, Indiana, the Total Quality Management (TQM) philosophy was used in the computer laboratories to better meet student needs. A customer satisfaction survey was conducted to gather data on lab facilities, lab assistants, and hardware/software; other sections of the survey included…

  1. Science Lab: A Peer Approach.

    ERIC Educational Resources Information Center

    Ronca, Courtney C.

    The two goals of this program were to increase the number of classroom teachers using the lab and to increase the amount of time that the science lab was used. The solution strategy chosen was a combination of peer tutoring, orientation presentations, small group discovery experiments and activities, and individual science experiment stations. The…

  2. Report from the banding lab

    USGS Publications Warehouse

    Tautin, J.

    1995-01-01

    Mr. Tautin reported on the seemingly everchanging structure of biological science units within the Interior Department. Current Congressional proposals would either change the name of the Bird Banding Lab's parent agency or make it part of the Geological Survey. The current Congress has not looked favorably on science budgets within the Interior Department, and the Banding Lab's budget is being squeezed ever tighter.

  3. Mass-transport deposits and reservoir quality of Upper Cretaceous Chalk within the German Central Graben, North Sea

    NASA Astrophysics Data System (ADS)

    Arfai, Jashar; Lutz, Rüdiger; Franke, Dieter; Gaedicke, Christoph; Kley, Jonas

    2016-04-01

    The architecture of intra-chalk deposits in the `Entenschnabel' area of the German North Sea is studied based on 3D seismic data. Adapted from seismic reflection characteristics, four types of mass-transport deposits (MTDs) are distinguished, i.e. slumps, slides, channels and frontal splay deposits. The development of these systems can be linked to inversion tectonics and halotectonic movements of Zechstein salt. Tectonic uplift is interpreted to have caused repeated tilting of the sea floor. This triggered large-scale slump deposition during Turonian-Santonian times. Slump deposits are characterised by chaotic reflection patterns interpreted to result from significant stratal distortion. The south-eastern study area is characterised by a large-scale frontal splay complex. This comprises a network of shallow channel systems arranged in a distributive pattern. Several slide complexes are observed near the Top Chalk in Maastrichtian and Danian sediments. These slides are commonly associated with large incisions into the sediments below. Best reservoir properties with high producible porosities are found in the reworked chalk strata, e.g. Danish North Sea, therefore MTDs detected in the study area are regarded as potential hydrocarbon reservoirs and considered as exploration targets.

  4. Geologic models and evaluation of undiscovered conventional and continuous oil and gas resources: Upper Cretaceous Austin Chalk

    USGS Publications Warehouse

    Pearson, Krystal

    2012-01-01

    The Upper Cretaceous Austin Chalk forms a low-permeability, onshore Gulf of Mexico reservoir that produces oil and gas from major fractures oriented parallel to the underlying Lower Cretaceous shelf edge. Horizontal drilling links these fracture systems to create an interconnected network that drains the reservoir. Field and well locations along the production trend are controlled by fracture networks. Highly fractured chalk is present along both regional and local fault zones. Fractures are also genetically linked to movement of the underlying Jurassic Louann Salt with tensile fractures forming downdip of salt-related structures creating the most effective reservoirs. Undiscovered accumulations should also be associated with structure-controlled fracture systems because much of the Austin that overlies the Lower Cretaceous shelf edge remains unexplored. The Upper Cretaceous Eagle Ford Shale is the primary source rock for Austin Chalk hydrocarbons. This transgressive marine shale varies in thickness and lithology across the study area and contains both oil- and gas-prone kerogen. The Eagle Ford began generating oil and gas in the early Miocene, and vertical migration through fractures was sufficient to charge the Austin reservoirs.

  5. Integrating geophysical and hydrochemical borehole-log measurements to characterize the Chalk aquifer, Berkshire, United Kingdom

    NASA Astrophysics Data System (ADS)

    Schürch, Marc; Buckley, David

    2002-09-01

    Geophysical and hydrochemical borehole-logging techniques were integrated to characterize hydraulic and hydrogeochemical properties of the Chalk aquifer at boreholes in Berkshire, UK. The down-hole measurements were made to locate fissures in the chalk, their spatial extent between boreholes, and to determine the groundwater chemical quality of the water-bearing layers. The geophysical borehole logging methods used were caliper, focused resistivity, induction resistivity, gamma ray, fluid temperature, fluid electrical conductivity, impeller and heat-pulse flowmeter, together with borehole wall optical-imaging. A multiparameter data transmitter was used to measure groundwater temperature, electrical conductivity, dissolved oxygen, pH, and redox potential of the borehole fluid down-hole. High permeability developed at the Chalk Rock by groundwater circulation provides the major flow horizon at the Banterwick Barn study site and represents a conduit system that serves as an effective local hydraulic connection between the boreholes. The Chalk Rock includes several lithified solution-ridden layers, hardgrounds, which imply a gap in sedimentation possibly representing an unconformity. Lower groundwater temperature, high dissolved-oxygen content, and flowmeter evidence of preferential groundwater flow in the Chalk Rock indicated rapid groundwater circulation along this horizon. By repeating the logging at different times of the year under changing hydraulic conditions, other water-inflow horizons within the Chalk aquifer were recognized. Résumé. Des techniques géophysiques et hydrochimiques de diagraphies en forage ont été mises en oeuvre pour caractériser les propriétés hydrauliques et hydrogéochimiques de l'aquifère de la craie dans des forages du Berkshire (Grande-Bretagne). Les mesures en descente ont été faites pour localiser les fissures dans la craie et leur développement spatial entre forages, et pour déterminer la qualité de l'eau souterraine des

  6. Nuclear Waste Analytical Round Robins 1-6 summary report

    SciTech Connect

    Smith, G.L.; Marschman, S.C.

    1993-12-31

    The MCC has conducted six round robins for the waste management, research, and development community from 1987 to present. The laboratories participating regularly are Ames, Argonne, Catholic University, Lawrence Livermore, Pacific Northwest Laboratory, Savannah River, and West Valley Nuclear. Glass types analyzed in these round robins all have been simulated nuclear waste compositions expected from vitrification of high-level nuclear waste. A wide range of analytical procedures have been used by the participating laboratories including Atomic Absorption spectroscopy, inductively coupled plasma-atomic emission spectroscopy, direct current plasma-emission spectroscopy, and inductively coupled plasma-mass spectroscopy techniques. Consensus average relative error for Round Robins 1 through 6 is 5.4%, with values ranging from 9.4 to 1.1%. Trend on the average improved with each round robin. When the laboratories analyzed samples over longer periods of time, the intralaboratory variability increased. Lab-to-lab variation accounts for most of the total variability found in all the round robins. Participation in the radiochemistry portion has been minimal, and analytical results poor compared to nonradiochemistry portion. Additional radiochemical work is needed in future round robins.

  7. Characterization of Acid Mine Drainage Sources Using Stable and Radiogenic Isotopes, Chalk Creek, Colorado

    NASA Astrophysics Data System (ADS)

    Cordalis, D.; Michel, R.; Williams, M.; Wireman, M.

    2003-12-01

    Acid mine drainage (AMD) affects many streams throughout the western United States. Understanding flow dynamics and sources within a fractured rock setting is necessary in outlining a potential remediation strategy for AMD. Radiogenic and stable isotopes of water were used in the Mary Murphy Mine, Chalk Creek, Colorado, in order to characterize flowpaths and sourcewaters. By delineating the sources of the mine water, groundwater, and event water, we may be able to target remediation techniques for individual contamination sources. Moreover, results from this research provide insights into groundwater flow systems in mountain environments of the Colorado Rockies. Tritium, a cosmogenic isotope of hydrogen, has a half-life 12.43y and is useful for studying hydrologic processes at the decadal time scale and can be used as an effective tracer when traditional chemical tracers are non-conservative. Hydrometric information showed that discharge from the mine adit exhibited a hydrograph characteristic of snowmelt runoff. However, mixing models using stable water isotopes (D and 18O) found less than 7% of the mine's peak discharge was from snowmelt, suggesting a regional groundwater dominated system. Mine interior samples fell into two characteristic groupings: either from the extreme north side of the drift which contained most of the zinc contamination, and all other locations. The waters from the north drift, MVN-3 and MVN-4, had lower 18O values, -17.62 per mil and -17.17 per mil, respectively, than did any of the other locations, suggesting a seasonal snowmelt input. However, the tritium values associated with MVN-3 and MVN-4 suggest at least some mixing, with values of 13.4 TU and 12.5 TU, respectively. Surface water samples from Chalk Creek show average tritium values of 11.1 TU, and 18O values of -14.87 per mil. Groundwater samples were captured using monitoring wells, and plotted according to the depth of screening. Alluvial wells carried a seasonal signal similar

  8. Speciation and weathering of selenium in upper cretaceous chalk and shale from South Dakota and Wyoming, USA

    NASA Astrophysics Data System (ADS)

    Kulp, Thomas R.; Pratt, Lisa M.

    2004-09-01

    In geologic materials, petroleum, and the environment, selenium occurs in various oxidation states (VI, IV, 0, -II), mineralized forms, and organo-Se complexes. Each of these forms is characterized by specific chemical and biochemical properties that control the element's solubility, toxicity, and environmental behavior. The organic rich chalks and shales of the Upper Cretaceous Niobrara Formation and the Pierre Shale in South Dakota and Wyoming are bentoniferous stratigraphic intervals characterized by anomalously high concentrations of naturally occurring Se. Numerous environmental problems have been associated with Se derived from these geological units, including the development of seleniferous soils and vegetation that are toxic to livestock and the contamination of drinking water supplies by Se mobilized in groundwater. This study describes a sequential extraction protocol followed by speciation treatments and quantitative analysis by Hydride Generation-Atomic Absorption Spectroscopy. This protocol was utilized to investigate the geochemical forms and the oxidation states in which Se occurs in these geologic units. Organic Se and di-selenide minerals are the predominant forms of Se present in the chalks, shales, and bentonites, but distinctive variations in these forms were observed between different sample types. Chalks contain significantly greater proportions of Se in the form of di-selenide minerals (including Se associated with pyrite) than the shales where base-soluble, humic, organo-Se complexes are more prevalent. A comparison between unweathered samples collected from lithologic drill cores and weathered samples collected from outcrop suggest that the humic, organic-Se compounds in shale are formed during oxidative weathering and that Se oxidized by weathering is more likely to be retained by shale than by chalk. Selenium enrichment in bentonites is inferred to result from secondary processes including the adsorption of Se mobilized by groundwater

  9. Thinking Outside the Lab

    NASA Astrophysics Data System (ADS)

    Colter, Tabitha

    2017-01-01

    As an undergraduate physics major who spent 2015 deep in a quantum optics lab at Oak Ridge National Laboratory, I knew my 2016 experience with the House of Representatives Energy and Commerce Committee would be a completely new challenge. I have long had a passion for the bridge of communication between the technical and non-technical worlds but it was only through my AIP Mather internship this summer that I was able to see that passion come to life in the realm of science policy. Suddenly, I went from squeezing political philosophy classes into my packed schedule to witnessing the political process first-hand. I was thrilled to find that the skills of critical thinking and communicating complex issues I have developed throughout my training as a physicist were directly applicable to my work in Congress. Overall, my experience this summer has given me insight into the inner workings of the federal policy process, deepened my appreciation for the work of government employees to keep Congressional members informed on the pressing current issues, and exposed me to a whole range of alternative careers within science. AIP and SPS

  10. Fault and fracture patterns in low porosity chalk and their potential influence on sub-surface fluid flow-A case study from Flamborough Head, UK

    NASA Astrophysics Data System (ADS)

    Sagi, D. A.; De Paola, N.; McCaffrey, K. J. W.; Holdsworth, R. E.

    2016-10-01

    To better understand fault zone architecture and fluid flow in mesoscale fault zones, we studied normal faults in chalks with displacements up to 20 m, at two representative localities in Flamborough Head (UK). At the first locality, chalk contains cm-thick, interlayered marl horizons, whereas at the second locality marl horizons were largely absent. Cm-scale displacement faults at both localities display ramp-flat geometries. Mesoscale fault patterns in the marl-free chalk, including a larger displacement fault (20 m) containing multiple fault strands, show widespread evidence of hydraulically-brecciated rocks, whereas clays smears along fault planes, and injected into open fractures, and a simpler fault zone architecture is observed where marl horizons are present. Hydraulic brecciation and veins observed in the marl-free chalk units suggest that mesoscale fault patterns acted as localized fault conduit allowing for widespread fluid flow. On the other hand, mesoscale fault patterns developed in highly fractured chalk, which contains interlayered marl horizons can act as localized barriers to fluid flow, due to the sealing effect of clays smears along fault planes and introduced into open fractures in the damage zone. To support our field observations, quantitative analyses carried out on the large faults suggest a simple fault zone in the chalk with marl units with fracture density/connectivity decreasing towards the protolith. Where marls are absent, density is high throughout the fault zone, while connectivity is high only in domains nearest the fault core. We suggest that fluid flow in fractured chalk is especially influenced by the presence of marls. When present, it can smear onto fault planes, forming localised barriers. Fluid flow along relatively large displacement faults is additionally controlled by the complexity of the fault zone, especially the size/geometry of weakly and intensely connected damage zone domains.

  11. Contribution of piezometric measurement to knowledge and management of low water levels: examples on the chalk aquifer in the Champagne Ardennes region

    NASA Astrophysics Data System (ADS)

    Stollsteiner, P.; Bessiere, H.; Nicolas, J.; Allier, D.; Berthet, O.

    2015-04-01

    This article is based on a BRGM study on piezometric indicators, threshold values of discharge and groundwater levels for the assessment of potentially-exploitable water resources of chalky watersheds. A method for estimating low water levels based on groundwater levels is presented from three examples representing chalk aquifers with different cycles: annual, combined and interannual. The first is located in Picardy and the two others in the Champagne-Ardennes region. Piezometers with annual cycles, used in these examples, are supposed to be representative of the aquifer hydro-dynamics. Except for multi-annual systems, the analysis between discharge measurements at a hydrometric station and groundwater levels measured at a piezometer representative of the main aquifer, leads to relatively precise and satisfactory relationships within a chalky context. These relationships may be useful for monitoring, validation, extension or reconstruction of the low water flow data. On the one hand, they allow definition of the piezometric levels corresponding to the different alert thresholds of river discharges. On the other hand, they clarify the proportions of low surface water flow from runoff or drainage of the aquifer. Finally, these correlations give an assessment of the minimum flow for the coming weeks. However, these correlations cannot be used to optimize the value of the exploitable water resource because it seems to be difficult to integrate the value of the effective rainfall that could occur during the draining period. Moreover, in the case of multi-annual systems, the solution is to attempt a comprehensive system modelling and, if it is satisfactory, using the simulated values to get rid of parasites or running the model for forecasting purposes.

  12. Spaceport Processing System Development Lab

    NASA Technical Reports Server (NTRS)

    Dorsey, Michael

    2013-01-01

    The Spaceport Processing System Development Lab (SPSDL), developed and maintained by the Systems Hardware and Engineering Branch (NE-C4), is a development lab with its own private/restricted networks. A private/restricted network is a network with restricted or no communication with other networks. This allows users from different groups to work on their own projects in their own configured environment without interfering with others utilizing their resources in the lab. The different networks being used in the lab have no way to talk with each other due to the way they are configured, so how a user configures his software, operating system, or the equipment doesn't interfere or carry over on any of the other networks in the lab. The SPSDL is available for any project in KSC that is in need of a lab environment. My job in the SPSDL was to assist in maintaining the lab to make sure it's accessible for users. This includes, but is not limited to, making sure the computers in the lab are properly running and patched with updated hardware/software. In addition to this, I also was to assist users who had issues in utilizing the resources in the lab, which may include helping to configure a restricted network for their own environment. All of this was to ensure workers were able to use the SPSDL to work on their projects without difficulty which would in turn, benefit the work done throughout KSC. When I wasn't working in the SPSDL, I would instead help other coworkers with smaller tasks which included, but wasn't limited to, the proper disposal, moving of, or search for essential equipment. I also, during the free time I had, used NASA's resources to increase my knowledge and skills in a variety of subjects related to my major as a computer engineer, particularly in UNIX, Networking, and Embedded Systems.

  13. Valuing river characteristics using combined site choice and participation travel cost models.

    PubMed

    Johnstone, C; Markandya, A

    2006-08-01

    This paper presents new welfare measures for marginal changes in river quality in selected English rivers. The river quality indicators used include chemical, biological and habitat-level attributes. Economic values for recreational use of three types of river-upland, lowland and chalk-are presented. A survey of anglers was carried out and using these data, two travel cost models were estimated, one to predict the numbers of trips and the other to predict angling site choice. These models were then linked to estimate the welfare associated with marginal changes in river quality using the participation levels as estimated in the trip prediction model. The model results showed that higher flow rates, biological quality and nutrient pollution levels affect site choice and influence the likelihood of a fishing trip. Consumer surplus values per trip for a 10% change in river attributes range from pound 0.04 to pound 3.93 ( pound 2001) depending on the attribute.

  14. Neutron Transversity at Jefferson Lab

    SciTech Connect

    Jian-Ping Chen; Xiaodong Jiang; Jen-chieh Peng; Lingyan Zhu

    2005-09-07

    Nucleon transversity and single transverse spin asymmetries have been the recent focus of large efforts by both theorists and experimentalists. On-going and planned experiments from HERMES, COMPASS and RHIC are mostly on the proton or the deuteron. Presented here is a planned measurement of the neutron transversity and single target spin asymmetries at Jefferson Lab in Hall A using a transversely polarized {sup 3}He target. Also presented are the results and plans of other neutron transverse spin experiments at Jefferson Lab. Finally, the factorization for semi-inclusive DIS studies at Jefferson Lab is discussed.

  15. Two-dimensional distribution of microbial activity and flow patterns within naturally fractured chalk.

    PubMed

    Arnon, Shai; Ronen, Zeev; Adar, Eilon; Yakirevich, Alexander; Nativ, Ronit

    2005-10-01

    The two-dimensional distribution of flow patterns and their dynamic change due to microbial activity were investigated in naturally fractured chalk cores. Long-term biodegradation experiments were conducted in two cores ( approximately 20 cm diameter, 31 and 44 cm long), intersected by a natural fracture. 2,4,6-tribromophenol (TBP) was used as a model contaminant and as the sole carbon source for aerobic microbial activity. The transmissivity of the fractures was continuously reduced due to biomass accumulation in the fracture concurrent with TBP biodegradation. From multi-tracer experiments conducted prior to and following the microbial activity, it was found that biomass accumulation causes redistribution of the preferential flow channels. Zones of slow flow near the fracture inlet were clogged, thus further diverting the flow through zones of fast flow, which were also partially clogged. Quantitative evaluation of biodegradation and bacterial counts supported the results of the multi-tracer tests, indicating that most of the bacterial activity occurs close to the inlet. The changing flow patterns, which control the nutrient supply, resulted in variations in the concentrations of the chemical constituents (TBP, bromide and oxygen), used as indicators of biodegradation.

  16. Temporal variability of local abundance, sex ratio and activity in the Sardinian chalk hill blue butterfly

    USGS Publications Warehouse

    Casula, P.; Nichols, J.D.

    2003-01-01

    When capturing and marking of individuals is possible, the application of newly developed capture-recapture models can remove several sources of bias in the estimation of population parameters such as local abundance and sex ratio. For example, observation of distorted sex ratios in counts or captures can reflect either different abundances of the sexes or different sex-specific capture probabilities, and capture-recapture models can help distinguish between these two possibilities. Robust design models and a model selection procedure based on information-theoretic methods were applied to study the local population structure of the endemic Sardinian chalk hill blue butterfly, Polyommatus coridon gennargenti. Seasonal variations of abundance, plus daily and weather-related variations of active populations of males and females were investigated. Evidence was found of protandry and male pioneering of the breeding space. Temporary emigration probability, which describes the proportion of the population not exposed to capture (e.g. absent from the study area) during the sampling process, was estimated, differed between sexes, and was related to temperature, a factor known to influence animal activity. The correlation between temporary emigration and average daily temperature suggested interpreting temporary emigration as inactivity of animals. Robust design models were used successfully to provide a detailed description of the population structure and activity in this butterfly and are recommended for studies of local abundance and animal activity in the field.

  17. Long-term reactive transport modelling of Berea and chalk core flood experiment

    NASA Astrophysics Data System (ADS)

    Souza, A. V.; Godoy, J.; Tonietto, G.

    2013-12-01

    Carbon sequestration in geological structures establishes a long-term chemical system between the dissolved gas, fluids and rocks from the injection site. Thus, the time scale used to assess the progress of chemical reactions is normally between tens and hundreds of years. Geochemical modeling is used in a variety of fields, including environmental protection and remediation, the petroleum industry, and economic geology and it is one of the best alternatives to evaluate the reactions with geochemical data possible injection sites. In this work we used data presented in a recent article (SPE165500) in different scenarios injection with three scales 50, 100, 250 and 1000 years. The experimental data used were from core flood experiment Berea and chalk in a condition similar to those found in the reservoirs of the North Sea. (340 bar and 130 C). The approach used to the lack of appropriate kinetic parameter in reservoir conditions, was the use of experimental data collected in two different conditions (340 bar and 130 C) and (2 Bar at room temperature) after the rocky core. The numerical simulations carried out using the same conditions with two different geochemical softwares PHREEQC and TOUGHREACTS. The results provide a detailed understanding of the system resulting rock-fluid-CO2 in the medium and long term. However, the accuracy of the models is strongly dependent on the mineral primary and secondary cores found in rocks.

  18. Incrusting and boring bryozoans from the Dessau Chalk Formation (Cretaceous), Little Walnut Creek, Austin, Texas

    SciTech Connect

    Morris, P.A. )

    1990-09-01

    Four sections were measured along a 1/4 mi length of Little Walnut Creek. The first section was 165 ft north of the US. 290 bridge while the fourth was 1/4 mi upstream. Structurally, the stream follows the fault in this section. Small faults can be found perpendicular to the primary fault and apparently account not only for minor variation in local dip (8{degrees}SE, parallel to 5{degrees}NW) but also for the placement of at least one tributary. Megainvertebrate exoskeletons were found to have been inhabited by incrusting bryozoans, boring bryozoans, and sponges. These fossils were found on both interior and exterior surfaces of Exogyra laeviuscula E tigrina, and interior surfaces of Inoceramus. A low-energy environment allowed exposure of megainvertebrate exoskeletons after death but also prevented fracturing. Low siltation rates also extended exoskeleton availability after organismic death. The nonboring bryozoans are cheilostomes and at least one species, Pyripora, has been described from the Kansas Cretaceous as well as European Cretaceous sites. The boring bryozoans are primarily represented by Terebripora sp. In conclusion, this section of Dessau Chalk Formation, Upper Austin Group, was mostly a low-energy environment, shallow, limy mud platform. This substrate was probably not stable enough for bryozoan colonization as unattached colonies have not been found in sediments. Therefore, bryozoan substrates were limited to living and dead Exogyra sp. and dead Inoceramus sp. exoskeletons.

  19. Penetration of herbicides to groundwater in an unconfined chalk aquifer following normal soil applications.

    PubMed

    Johnson, A C; Besien, T J; Bhardwaj, C L; Dixon, A; Gooddy, D C; Haria, A H; White, C

    2001-12-01

    The persistence and penetration of the herbicides isoproturon and chlorotoluron in an unconfined chalk aquifer has been monitored over a 4-year period through soil sampling, shallow coring and groundwater monitoring. Chlorotoluron was applied on plots as a marker compound, having never been used previously on that, or surrounding fields. The fieldsite had a 5 degree slope with soil depths of 0.5 to 1.5 m and a water table between 20 and 5 m from the soil surface. Where the water table was deepest (9-20 m below surface (mbs)) little or no positive herbicide detections were made. However, where the water table was at only 4-5 mbs, a regular pesticide signal of around 0.1 microg/l for isoproturon and chlorotoluron could be distinguished. Over the winter recharge period automatic borehole samplers revealed a series of short-lived peaks of isoproturon and chlorotoluron reaching up to 0.8 microg/l. This is consistent with a preferential flow mechanism operating at this particular part of the field. Such peaks were occurring over 2 years after the last application of these compounds. Shallow coring failed to uncover any significant pesticide pulse moving through the deep unsaturated zone matrix at the fieldsite.

  20. Identification of unknown microcontaminants in Dutch river water by liquid chromatography-high resolution mass spectrometry and nuclear magnetic resonance spectroscopy.

    PubMed

    van Leerdam, J A; Vervoort, J; Stroomberg, G; de Voogt, P

    2014-11-04

    In the past decade during automated surface water monitoring in the river Meuse at border station Eijsden in The Netherlands, a set of unknown compounds were repeatedly detected by online liquid chromatography-diode-array detection in a relatively high signal intensity. Because of the unknown nature of the compounds, the consequently unknown fate of this mixture in water treatment processes, the location being close to the water inlet of a drinking water supply company and their possible adverse public health effects, it was deemed necessary to elucidate the identity of the compounds. No data are available for the occurrence of these unknowns at downstream locations. After concentration and fractionation of a sample by preparative Liquid Chromatography, identification experiments were performed using Liquid Chromatography-High Resolution Mass Spectrometry (LC-HR-MS) combined with High Resolution Nuclear Magnetic Resonance Spectroscopy (HR-NMR). Accurate mass determination of the unknown parent compound and its fragments obtained in MS/MS provided relevant information on the elemental composition of the unknown compounds. With the use of NMR techniques and the information about the elemental composition, the identity of the compounds in the different sample fractions was determined. Beside some regularly detected compounds in surface water, like caffeine and bisphenol-S, five dihydroxydiphenylmethane isomers were identified. The major unknown compound was identified as 4,4'-dihydroxy-3,5,3',5'-tetra(hydroxymethyl)diphenylmethane. This compound was confirmed by analysis of the pure reference compound. This is one of the first studies that employs the combination of high resolution MS with NMR for identification of truly unknown compounds in surface waters at the μg/L level. Five of the seven identified compounds are unexpected and not contained in the CAS database, while they can be presumed to be products generated during the production of resins.

  1. Proposed Holistic Strategy for the Closure of F-Area, A Large Nuclear Industrial Complex at the Savannah River Site, South Carolina

    SciTech Connect

    SHEDROW, CB

    2004-02-10

    F-Area is a large nuclear complex located near the center of the Department of Energy's (DOEs) Savannah River Site in South Carolina. The present closure strategy for F-Area is based on established SRS protocol for a site-specific, graded approach to deactivation and decommissioning. Uncontaminated facilities will be closed under the National Environmental Policy Act (NEPA). Facilities requiring removal or in-situ disposition of residual chemical and/or radiological inventories will be decommissioned under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The F-Area Tank Farm, which is permitted under the Clean Water Act, will be closed in accordance with an industrial wastewater closure plan. F-Area closure will also involve the near- and long-term remediation of contaminated soil and groundwater resources. The proposed holistic F-Area closure strategy would enhance the existing project-specific SRS closure protocol by incorporating a comprehensive area-wide groundwater modeling tool, or Composite Analysis. The use of this methodology would allow for the assessment of the relative impacts of individual projects, as well as the cumulative effect of all F-Area closure actions, on area groundwater resources. Other critical elements of the proposed strategy include (i) the consistent use of site-specific Risk Assessments (RAs) and Performance Assessments (PAs), (ii) the closer integration of selected soil and groundwater closure projects and near-term D and D projects, and (iii) the creation of an Area Core Team (ACT) consisting of DOE and selected regulator decision-makers to direct area D and D and environmental restoration activities. This holistic approach would facilitate the effective targeting of agency resources on high priority projects whose closure would have the greatest impact on achieving the desired area-wide risk-based end-state and accelerate delisting of F-Area from the National Priority List (NPL).

  2. Computation and Analysis of the Global Distribution of the Radioxenon Isotope 133Xe based on Emissions from Nuclear Power Plants and Radioisotope Production Facilities and its Relevance for the Verification of the Nuclear-Test-Ban Treaty

    NASA Astrophysics Data System (ADS)

    Wotawa, Gerhard; Becker, Andreas; Kalinowski, Martin; Saey, Paul; Tuma, Matthias; Zähringer, Matthias

    2010-05-01

    Monitoring of radioactive noble gases, in particular xenon isotopes, is a crucial element of the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The capability of the noble gas network, which is currently under construction, to detect signals from a nuclear explosion critically depends on the background created by other sources. Therefore, the global distribution of these isotopes based on emissions and transport patterns needs to be understood. A significant xenon background exists in the reactor regions of North America, Europe and Asia. An emission inventory of the four relevant xenon isotopes has recently been created, which specifies source terms for each power plant. As the major emitters of xenon isotopes worldwide, a few medical radioisotope production facilities have been recently identified, in particular the facilities in Chalk River (Canada), Fleurus (Belgium), Pelindaba (South Africa) and Petten (Netherlands). Emissions from these sites are expected to exceed those of the other sources by orders of magnitude. In this study, emphasis is put on 133Xe, which is the most prevalent xenon isotope. First, based on the emissions known, the resulting 133Xe concentration levels at all noble gas stations of the final CTBT verification network were calculated and found to be consistent with observations. Second, it turned out that emissions from the radioisotope facilities can explain a number of observed peaks, meaning that atmospheric transport modelling is an important tool for the categorization of measurements. Third, it became evident that Nuclear Power Plant emissions are more difficult to treat in the models, since their temporal variation is high and not generally reported. Fourth, there are indications that the assumed annual emissions may be underestimated by factors of two to ten, while the general emission patterns seem to be well understood. Finally, it became evident that 133Xe sources mainly influence the sensitivity of the

  3. Hospital labs go under microscope.

    PubMed

    Aston, Geri

    2014-05-01

    Financial pressures are hitting hospital clinical labs on both the inpatient and outpatient sides. To control expenses, hospitals are teaming up to buy supplies, centralizing services and improving blood management.

  4. State of the Lab 2012

    ScienceCinema

    King, Alex

    2016-07-12

    Ames Laboratory Director Alex King delivers the annual State of the Lab address on Thursday, May 17, 2012, the 65th Anniversary of the founding of The Ames Laboratory. This video contains highlights from the address.

  5. An Annotated Math Lab Inventory.

    ERIC Educational Resources Information Center

    Schussheim, Joan Yares

    1980-01-01

    A listing of mathematics laboratory material is organized as follows: learning kits, tape programs, manipulative learning materials, publications, math games, math lab library, and an alphabetized listing of publishers and/or companies offering materials. (MP)

  6. State of the Lab 2012

    SciTech Connect

    King, Alex

    2012-01-01

    Ames Laboratory Director Alex King delivers the annual State of the Lab address on Thursday, May 17, 2012, the 65th Anniversary of the founding of The Ames Laboratory. This video contains highlights from the address.

  7. Generalized Nanosatellite Avionics Testbed Lab

    NASA Technical Reports Server (NTRS)

    Frost, Chad R.; Sorgenfrei, Matthew C.; Nehrenz, Matt

    2015-01-01

    The Generalized Nanosatellite Avionics Testbed (G-NAT) lab at NASA Ames Research Center provides a flexible, easily accessible platform for developing hardware and software for advanced small spacecraft. A collaboration between the Mission Design Division and the Intelligent Systems Division, the objective of the lab is to provide testing data and general test protocols for advanced sensors, actuators, and processors for CubeSat-class spacecraft. By developing test schemes for advanced components outside of the standard mission lifecycle, the lab is able to help reduce the risk carried by advanced nanosatellite or CubeSat missions. Such missions are often allocated very little time for testing, and too often the test facilities must be custom-built for the needs of the mission at hand. The G-NAT lab helps to eliminate these problems by providing an existing suite of testbeds that combines easily accessible, commercial-offthe- shelf (COTS) processors with a collection of existing sensors and actuators.

  8. Early diagenesis and chalk-chert hardgrounds in the Coniacian-Campanian of central Jordan; implications for sedimentation on Late Cretaceous shallow pelagic ramps

    NASA Astrophysics Data System (ADS)

    Powell, J. H.; Moh'd, B. K.

    2009-04-01

    Hardgrounds and omission surfaces are rare in the predominantly hemi-pelagic chalk, chert and phosphorite association that comprises the Senonian Belqa Group in central Jordan. However, hardgrounds of regional extent are described from the base of the Dhiban Chalk Member (Santonian-Campanian) in Wadi Mujib, central Jordan, and at Jibal Khureij, southern Wadi Araba that reveal a complex pattern of sedimentation and early diagenesis. The chalk-chert-phosphorite succession was deposited in a shallow pelagic ramp setting in fluctuating water depths. Chalks represent high-stands, separated by a regressive chert-rich unit (Tafilah Member). Synchronous hardground successions traced over 100 km, reveal a complex diagenetic and depositional history of early lithification, phosphatisation, penecontemporaneous deformation, submarine bioerosion, colonisation by colonial corals and/or bivalves followed by deposition of turbid detrital chalk passing up to pelagic coccolith ooze. Variations in the hardground successions are attributed to their relative position on the pelagic ramp in overall response to a third order sea-level rise.

  9. The PRIME Lab biomedical program

    NASA Astrophysics Data System (ADS)

    Jackson, George S.; Elmore, David; Rickey, Frank A.; Musameh, Sharif M.; Sharma, Pankaj; Hillegonds, Darren; Coury, Louis; Kissinger, Peter

    2000-10-01

    The biomedical accelerator mass spectrometry (AMS) initiative at PRIME Lab including the status of equipment and sample preparation is described. Several biomedical projects are underway involving one or more of the nuclides: 14C, 26Al and 41Ca. Routine production of CaF 2 and graphite is taking place. Finally, the future direction and plans for improvement of the biomedical program at PRIME Lab are discussed.

  10. Virtual Labs and Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Boehler, Ted

    2006-12-01

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

  11. The history of Rhoton's Lab.

    PubMed

    Matsushima, Toshio; Richard Lister, J; Matsushima, Ken; de Oliveira, Evandro; Timurkaynak, Erdener; Peace, David A; Kobayashi, Shigeaki

    2017-09-06

    The work performed in Dr. Rhoton's Lab, represented by over 500 publications on microneurosurgical anatomy, greatly contributed to improving the level of neurosurgical treatment throughout the world. The authors reviewed the development and activities of the Lab over 40 years. Dr. Albert L. Rhoton Jr., the founder of, and leader in, this field, displayed great creativity and ingenuity during his life. He devoted himself to perfecting his study methodology, employing high-definition photos and slides to enhance the quality of his published papers. He dedicated his life to the education of neurosurgeons. His "lab team," which included microneuroanatomy research fellows, medical illustrators, lab directors, and secretaries, worked together under his leadership to develop the methods and techniques of anatomical study to complete over 160 microneurosurgical anatomy projects. The medical illustrators adapted computer technologies and integrated art and science in the field of microneurosurgical anatomy. Dr. Rhoton's fellows established methods of injecting colors and pursued a series of projects to innovate surgical approaches and instruments over a 40-year period. They also continued to help Dr. Rhoton to conduct international educational activities after returning to their home countries. Rhoton's Lab became a world-renowned anatomical lab as well as a microsurgical training center and generated the knowledge necessary to perform accurate, gentle, and safe surgery for the sake of patients.

  12. Jigsaw Cooperative Learning Improves Biology Lab Courses.

    ERIC Educational Resources Information Center

    Colosi, Joseph C.; Zales, Charlotte Rappe

    1998-01-01

    Describes how a jigsaw cooperative learning structure divides lab work in a constructive, efficient way and provides a mechanism for sharing information. Pre-lab lectures are replaced with focused student discussions about the lab exercises. Students become more involved with the lab exercises, take responsibility for their own learning, and are…

  13. The effect of aging, temperature and brine composition on the mechanical strength of chalk

    NASA Astrophysics Data System (ADS)

    Korsnes, Reidar Inge; Nermoen, Anders; Stødle, Trond; Vika Storm, Eirik; Vadla Madland, Merete

    2014-05-01

    Chalk strength has been of great focus for several research communities since the 1980s when the Ekofisk subsidence problem was discovered. Sea water injection was initiated in 1987 to improve the oil production and to re-pressurize the reservoirs to halt the subsidence. The oil production was improved significantly, but the reservoir compaction in the water saturated regions continued, in contrast to the regions with no water breakthrough. This observation indicates a water weakening effect of the chalk. Extensive studies have been performed during the last decades to enlighten how the brine chemistry alters the rock mechanical properties. These studies have shown that the elastic bulk modulus, yield strength, creep and the deformation rate at constant stress conditions depend on the pore fluid composition. In general, the injected brine is in non-equilibrium with the rock surface inducing alteration of the rock mineralogy. In this study we examined two aspects of the mechanical strength, namely the bulk modulus and the onset of yield during hydrostatic stress loading with 0.7 MPa pore pressure. The test program consisted of aged and un-aged cores, ambient and 130°C test temperature, and four brine compositions: MgCl2, NaCl, Na2SO4, and synthetic sea water (SSW) at ion strengths of 0.657 M. The aging was performed by submerging saturated cores in a closed container with the respective test brine for three weeks at 130°C. Un-aged cores were saturated the same day as they were tested. For each brine composition we present four test setups; (a) aged and tested at 130°C, (b) aged and tested at ambient temperature, (c) un-aged and tested at 130°C, and (d) un-aged and tested at ambient conditions. The main results from our study are: 1. By using NaCl and MgCl2 as saturating brines, neither the test temperature nor the aging procedure affected the yield stress and bulk modulus significantly. 2. Using Na2SO4, the yield point and bulk moduli were reduced if the core

  14. Fractional flow in fractured chalk; a flow and tracer test revisited.

    PubMed

    Odling, N E; West, L J; Hartmann, S; Kilpatrick, A

    2013-04-01

    A multi-borehole pumping and tracer test in fractured chalk is revisited and reinterpreted in the light of fractional flow. Pumping test data analyzed using a fractional flow model gives sub-spherical flow dimensions of 2.2-2.4 which are interpreted as due to the partially penetrating nature of the pumped borehole. The fractional flow model offers greater versatility than classical methods for interpreting pumping tests in fractured aquifers but its use has been hampered because the hydraulic parameters derived are hard to interpret. A method is developed to convert apparent transmissivity and storativity (L(4-n)/T and S(2-n)) to conventional transmissivity and storativity (L2/T and dimensionless) for the case where flow dimension, 2

  15. The magnetostratigraphy of Coniacian-Late Campanian chalk sequences in southern England

    NASA Astrophysics Data System (ADS)

    Montgomery, Paul; Hailwood, Ernie A.; Gale, Andy S.; Burnett, Jackie A.

    1998-03-01

    Magnetostratigraphic data are reported from the Coniacian to early Late Campanian chalk sequences at Culver Cliff and Scratchell's Bay on the Isle of Wight and Seaford Head in East Sussex, UK. Mean natural remanent magnetisation (NRM) intensity values for individual sample sites range from 0.0013 to 1.6008 mA/m, with an overall mean of 0.0165 mA/m. Reliable determination of the remanence of the very weakly magnetic units was achieved by carrying out replicate palaeomagnetic measurements on large volume samples, using a 2-G 'wholecore' cryogenic magnetometer. Palaeomagnetic measurements on other, standard-sized samples were made with a CCL 'discrete sample' cryogenic magnetometer. Incremental thermal and AF demagnetisation treatment was used to remove magnetic overprints and to isolate the characteristic remanent magnetisation (ChRM). A reliability classification scheme has been developed and applied in this study, to provide an objective assessment of the quality of the palaeomagnetic results. IRM acquisition experiments suggest that the dominant magnetic mineral in these sediments is magnetite, but mixtures of hematite and magnetite occur also. SEM and TEM studies of magnetic mineral extracts indicate the presence of magnetite and hematite, preserved as inclusions within silicate grains, together with abundant bacterial magnetite preserved as individual grains and chains in some samples. Samples containing the greatest proportions of bacterial magnetite generally have the highest NRM intensity. The composite magnetic polarity sequence, derived by combining the data from all three sections, is characterised by three principal magnetic polarity zones which can be correlated with geomagnetic Chrons C34n, C33r and C33n, respectively. The positions of the chron boundaries have been tied to macrofossil and nannofossil biostratigraphic zones in these sections. A series of previously undocumented short magnetic polarity sub-chrons has been identified within the longer

  16. Status of chemistry lab safety in Nepal

    PubMed Central

    Kandel, Krishna Prasad; Neupane, Bhanu Bhakta

    2017-01-01

    Chemistry labs can become a dangerous environment for students as the lab exercises involve hazardous chemicals, glassware, and equipment. Approximately one hundred thousand students take chemistry laboratory classes annually in Nepal. We conducted a survey on chemical lab safety issues across Nepal. In this paper, we assess the safety policy and equipment, protocols and procedures followed, and waste disposal in chemistry teaching labs. Significant population of the respondents believed that there is no monitoring of the lab safety in their lab (p<0.001). Even though many labs do not allow food and beverages inside lab and have first aid kits, they lack some basic safety equipment. There is no institutional mechanism to dispose lab waste and chemical waste is disposed haphazardly. Majority of the respondents believed that the safety training should be a part of educational training (p = 0.001) and they would benefit from short course and/or workshop on lab safety (p<0.001). PMID:28644869

  17. Status of chemistry lab safety in Nepal.

    PubMed

    Kandel, Krishna Prasad; Neupane, Bhanu Bhakta; Giri, Basant

    2017-01-01

    Chemistry labs can become a dangerous environment for students as the lab exercises involve hazardous chemicals, glassware, and equipment. Approximately one hundred thousand students take chemistry laboratory classes annually in Nepal. We conducted a survey on chemical lab safety issues across Nepal. In this paper, we assess the safety policy and equipment, protocols and procedures followed, and waste disposal in chemistry teaching labs. Significant population of the respondents believed that there is no monitoring of the lab safety in their lab (p<0.001). Even though many labs do not allow food and beverages inside lab and have first aid kits, they lack some basic safety equipment. There is no institutional mechanism to dispose lab waste and chemical waste is disposed haphazardly. Majority of the respondents believed that the safety training should be a part of educational training (p = 0.001) and they would benefit from short course and/or workshop on lab safety (p<0.001).

  18. An extensive study of the concentrations of particulate/dissolved radiocaesium derived from the Fukushima Dai-ichi Nuclear Power Plant accident in various river systems and their relationship with catchment inventory.

    PubMed

    Yoshimura, Kazuya; Onda, Yuichi; Sakaguchi, Aya; Yamamoto, Masayoshi; Matsuura, Yuki

    2015-01-01

    An extensive investigation of particulate radiocaesium in suspended solids and dissolved radiocaesium in river water was undertaken at 30 sites in Fukushima and Miyagi Prefectures in December 2012, and their relationships with catchment inventory and the solid/liquid distribution coefficient (Kd) were evaluated. Rivers located in the coastal region on the north side of the Fukushima Dai-ichi Nuclear Power Plant exhibited relatively higher particulate radiocaesium concentrations. Significant correlations were found between concentrations of particulate/dissolved radiocaesium and average catchment inventories, indicating that the concentrations of particulate/dissolved radiocaesium could be approximated from the catchment inventory. Particulate radiocaesium concentration was significantly correlated with dissolved radiocaesium concentration (with the exception of concentrations measured in estuaries), and the geometric mean Kd was calculated as 3.6 × 10(5) with a 95% confidence interval of 2.6-5.1 × 10(5).

  19. Draft Genome Sequence of a Thermophilic Cyanobacterium from the Family Oscillatoriales (Strain MTP1) from the Chalk River, Colorado.

    PubMed

    Hallenbeck, Patrick C; Grogger, Melanie; Mraz, Megan; Veverka, Donald

    2016-02-18

    The draft genome (57.7% GC, 7,647,882 bp) of the novel thermophilic cyanobacterium MTP1 was determined by metagenomics of an enrichment culture. The genome shows that it is in the family Oscillatoriales and encodes multiple heavy metal resistances as well as the capacity to make exopolysaccharides.

  20. The direct determination of the masses of unstable atoms with the chalk river on-line isotope separator

    NASA Astrophysics Data System (ADS)

    Sharma, K. S.; Schmeing, H.; Evans, H. C.; Hagberg, E.; Hardy, J. C.; Koslowsky, V. T.

    1989-02-01

    A new technique has been developed to measure the spacing of atomic mass doublets of radioactive isotopes directly with an on-line isotope separator. It relies not on ion detection but on observation of the specific radioactive signature of the isotopes under study. Consequently, line shapes and centroids can be determined, free of interference and with great accuracy, even if the corresponding beams strongly overlap or if they are contaminated by unwanted isobars or isomers. In particular, it is of no consequence if one or both members of the doublet are masked by stable background peaks. Doublets are peak matched as in a conventional mass spectrometer. The technique has been evaluated with beams of radioactive nuclides whose masses are known independently. Based on careful calibrations, two new mass values have been obtained: 72Br, 71 936 340 ± 430 μu and 63Ga, 62 939 570 ± 150 μu.

  1. Compaction of North-sea chalk by pore-failure and pressure solution in a producing reservoir

    NASA Astrophysics Data System (ADS)

    Keszthelyi, Daniel; Dysthe, Dag; Jamtveit, Bjorn

    2016-02-01

    The Ekofisk field, Norwegian North sea,is an example of compacting chalk reservoir with considerable subsequent seafloor subsidence due to petroleum production. Previously, a number of models were created to predict the compaction using different phenomenological approaches. Here we present a different approach, we use a new creep model based on microscopic mechanisms with no fitting parameters to predict strain rate at core scale and at reservoir scale. The model is able to reproduce creep experiments and the magnitude of the observed subsidence making it the first microstructural model which can explain the Ekofisk compaction.

  2. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  3. A Comparative Study on Real Lab and Simulation Lab in Communication Engineering from Students' Perspectives

    ERIC Educational Resources Information Center

    Balakrishnan, B.; Woods, P. C.

    2013-01-01

    Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised…

  4. A Comparative Study on Real Lab and Simulation Lab in Communication Engineering from Students' Perspectives

    ERIC Educational Resources Information Center

    Balakrishnan, B.; Woods, P. C.

    2013-01-01

    Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised…

  5. The behaviour and fate of Nitrate and Phosphate present in treated wastewater when discharged to the Chalk aquifer of SE England

    NASA Astrophysics Data System (ADS)

    Phillips, Richard; Smith, Martin; Pope, David

    2013-04-01

    The Chalk aquifer of South East England is a major groundwater resource and regionally supplies up to 70% of all water abstracted for potable purposes. The two main pressures on groundwater resources are considered to be climate change and population growth. As the demand for water increases, so does the volume of wastewater that has to be treated to acceptable levels before being discharged back into the environment. Aquifer storage and recovery (ASR) is form of groundwater resource management whereby water is pumped or injected into the ground and allowed to percolate through to the saturated zone before being abstracted at a later date. By injecting water into the ground during periods of high precipitation (i.e. winter months) an increased volume of water is made available for later abstraction (i.e. during summer months) helping water resource planners better manage the supply demand balance. In the case of using treated wastewater as a source for artificial recharge, there is little published research on the behaviour and fate of the main contaminants of concern that are found in treated wastewater when they are discharged to the principal aquifer (the Chalk) of SE England. Nitrate and Phosphate are listed (amongst others) as the main contaminants of concern that are present in treated wastewater and discharged to the Chalk aquifer when this practice occurs. The CLIMAWAT project is an EU-Regional Development Fund Interreg IV funded research programme to study the impacts of climate change on groundwater resources and groundwater quality from the Chalk aquifer of SE England. The use of treated wastewater for artificial recharge has been extensively studied in both the field and laboratory to better assess how sustainable this practice is in terms of risk of pollution to the groundwater body. The results of the laboratory programme include breakthrough curves for Nitrate and Phosphate in the Chalk matrix under unsaturated and saturated conditions. Whilst

  6. Big projects could threaten weapons labs` research base

    SciTech Connect

    Lawler, A.

    1996-05-24

    Every few seconds, a mushroom cloud explodes on Paul Cunningham`s Computer screen. The unsettling image is a screen saver in the office of the chief of nuclear materials and stockpile management at Los Alamos National Laboratory - and a wry reminder of the radical changes underway at the three US weapons labs. Now that the US has renounced underground nuclear testing, simulations are becoming the weapons designers chief tool for ensuring that the nuclear arsenal is reliable. The new approach to testing, stockpile stewardship, has triggered a fierce debate within the defense community. At issue is how to keep a balance between financing such new and costly stewardship projects as the $1.1 billion National Ignition Facility, which will simulate the conditions of nuclear detonation, and maintaining a critical mass of experienced weapons designers. This artical describes the debate and funding and political problems which go with it.

  7. Law enforcement tools available at the Savannah River Site

    SciTech Connect

    Hofstetter, K.J.

    2000-03-29

    A number of nuclear technologies developed and applied at the Savannah River Site in support of nuclear weapons material production and environmental remediation can be applied to problems in law enforcement. Techniques and equipment for high-sensitivity analyses of samples are available to identify and quantify trace elements and establish origins and histories of forensic evidence removed from crime scenes. While some of theses capabilities are available at local crime laboratories, state-of-the-art equipment and breakthroughs in analytical techniques are continually being developed at DOE laboratories. Extensive experience with the handling of radioactive samples at the DOE labs minimizes the chances of cross-contamination of evidence received from law enforcement. In addition to high-sensitivity analyses, many of the field techniques developed for use in a nuclear facility can assist law enforcement personnel in detecting illicit materials and operations, in retrieving of pertinent evidence and in surveying crime scenes. Some of these tools include chemical sniffers, hand-held detectors, thermal imaging, etc. In addition, mobile laboratories can be deployed to a crime scene to provide field screening of potential evidence. A variety of portable sensors can be deployed on vehicle, aerial, surface or submersible platforms to assist in the location of pertinent evidence or illicit operations. Several specific nuclear technologies available to law enforcement and their potential uses are discussed.

  8. Development and Implementation of a Comprehensive Program to Deal with Canada's Nuclear Legacy Liabilities

    SciTech Connect

    Brown, Peter; Metcalfe, Douglas; Blanchette, Marcia; Dolinar, George; Halpenny, Steven; Purdy, Chris; Smith, David; Kupferschmidt, William

    2008-01-15

    The Government of Canada nuclear legacy liabilities have resulted from 60 years of nuclear research and development (R and D) carried out on behalf of Canada by the National Research Council (1944 to 1952) and Atomic Energy of Canada Limited (AECL, 1952 to present). These liabilities are largely located at AECL research sites, and consist of shutdown research buildings (including several prototype and research reactors), a wide variety of buried and stored wastes, and contaminated lands. The shutdown buildings and contaminated lands need to be safely decommissioned to meet federal regulatory requirements, and long-term solutions need to be developed and implemented for management of the wastes. More than half of the liabilities are the result of Cold War activities during the 1940's, 50's and early 60's. The remaining liabilities stem from R and D for medical isotopes and nuclear reactor technology, as well as national science programs. About 70 percent of the liabilities are located at AECL's Chalk River Laboratories (CRL) in Ontario, and a further 20 percent are located at AECL's shutdown Whiteshell Laboratories in Manitoba. The remaining 10 percent relate largely to three shutdown prototype reactors in Ontario and Quebec, which were key to the developmental stage of Canada's CANDU reactor technology. The inventory of legacy waste includes spent fuel, high-level, intermediate-level and low-level solid and liquid radioactive waste, and wastes (largely contaminated soils) from site clean-up work across Canada. Most of the wastes are in raw, unconditioned form, and limited characterization information is available for the wastes generated in past decades. In many cases unique and potentially costly solutions will be required to recover, handle and process the wastes. In conclusion: the Government of Canada has initiated a program to deal with nuclear legacy liabilities dating back to the Cold War and the birth of nuclear technologies and medicine in Canada. The 5

  9. Infrared spectroscopy and density functional theory investigation of calcite, chalk, and coccoliths--do we observe the mineral surface?

    PubMed

    Andersson, M P; Hem, C P; Schultz, L N; Nielsen, J W; Pedersen, C S; Sand, K K; Okhrimenko, D V; Johnsson, A; Stipp, S L S

    2014-11-13

    We have measured infrared spectra from several types of calcite: chalk, freshly cultured coccoliths produced by three species of algae, natural calcite (Iceland Spar), and two types of synthetic calcite. The most intense infrared band, the asymmetric carbonate stretch vibration, is clearly asymmetric for the coccoliths and the synthetic calcite prepared using the carbonation method. It can be very well fitted by two peaks: a narrow Lorenzian at lower frequency and a broader Gaussian at higher frequency. These two samples both have a high specific surface area. Density functional theory for bulk calcite and several calcite surface systems allows for assignment of the infrared bands. The two peaks that make up the asymmetric carbonate stretch band come from the bulk (narrow Lorenzian) and from a combination of two effects (broad Gaussian): the surface or near surface of calcite and line broadening from macroscopic dielectric effects. We detect water adsorbed on the high surface area synthetic calcite, which permits observation of the chemistry of thin liquid films on calcite using transmission infrared spectroscopy. The combination of infrared spectroscopy and density functional theory also allowed us to quantify the amount of polysaccharides associated with the coccoliths. The amount of polysaccharides left in chalk, demonstrated to be present in other work, is below the IR detection limit, which is 0.5% by mass.

  10. Albanian violets of the section Melanium, their morphological variability, genetic similarity and their adaptations to serpentine or chalk soils.

    PubMed

    Słomka, Aneta; Godzik, Barbara; Szarek-Łukaszewska, Grażyna; Shuka, Lulëzim; Hoef-Emden, Kerstin; Bothe, Hermann

    2015-02-01

    Violets of the section Melanium from Albanian serpentine and chalk soils were examined for their taxonomic affiliations, their ability to accumulate heavy metals and their colonization by arbuscular mycorrhizal fungi (AMF). The sequence analysis of the ITS1-5.8S rDNA-ITS2 region showed that all the sampled six Albanian violets grouped between Viola lutea and Viola arvensis, but not with Viola tricolor. The fine resolution of the ITS sequences was not sufficient for a further delimitation of the Albanian violets within the V. lutea-V. arvensis clade. Therefore, the Albanian violets were classified by a set of morphological characters. Viola albanica, Viola dukadjinica and Viola raunsiensis from serpentine soils as well as Viola aetolica from a chalk meadow were unambiguously identified, whereas the samples of Viola macedonica showed high morphological variability. All the violets, in both roots and shoots contained less than or similar levels of heavy metals as their harboring soils, indicating that they were heavy metal excluders. All the violets were strongly colonized by AMF with the remarkable exception of V. albanica. This violet lived as a scree creeper in shallow serpentine soil where the concentration of heavy metals was high but those of P, K and N were scarce.

  11. Hydrochemical and isotopic effects associated with petroleum fuel biodegradation pathways in a chalk aquifer

    NASA Astrophysics Data System (ADS)

    Spence, Michael J.; Bottrell, Simon H.; Thornton, Steven F.; Richnow, Hans H.; Spence, Keith H.

    2005-09-01

    Hydrochemical data, compound specific carbon isotope analysis and isotopic enrichment trends in dissolved hydrocarbons and residual electron acceptors have been used to deduce BTEX and MTBE degradation pathways in a fractured chalk aquifer. BTEX compounds are mineralised sequentially within specific redox environments, with changes in electron acceptor utilisation being defined by the exhaustion of specific BTEX components. A zone of oxygen and nitrate exhaustion extends approximately 100 m downstream from the plume source, with residual sulphate, toluene, ethylbenzene and xylene. Within this zone complete removal of the TEX components occurs by bacterial sulphate reduction, with sulphur and oxygen isotopic enrichment of residual sulphate ( ɛs=- 14.4‰ to - 16.0‰). Towards the plume margins and at greater distance along the plume flow path nitrate concentrations increase with δ15N values of up to + 40‰ indicating extensive denitrification. Benzene and MTBE persist into the denitrification zone, with carbon isotope enrichment of benzene indicating biodegradation along the flow path. A Rayleigh kinetic isotope enrichment model for 13C-enrichment of residual benzene gives an apparent ɛ value of - 0.66‰. MTBE shows no significant isotopic enrichment ( δ13C = - 29.3‰ to - 30.7‰) and is isotopically similar to a refinery sample ( δ13C = - 30.1‰). No significant isotopic variation in dissolved MTBE implies that either the magnitude of any biodegradation-induced isotopic fractionation is small, or that relatively little degradation has taken place in the presence of BTEX hydrocarbons. It is possible, however, that MTBE degradation occurs under aerobic conditions in the absence of BTEX since no groundwater samples were taken with co-existing MTBE and oxygen. Low benzene δ13C values are correlated with high sulphate δ34S, indicating that little benzene degradation has occurred in the sulphate reduction zone. Benzene degradation may be associated with

  12. Comparative estimates of transpiration of ash and beech forest at a chalk site in southern Britain

    NASA Astrophysics Data System (ADS)

    Roberts, John; Rosier, Paul T. W.

    1994-11-01

    (1) During the dry summer of 1989 stomatal conductance ( gs), boundary-layer conductance ( ga), leaf water and osmotic potentials ( ψ1, ψπ) and leaf area index ( L∗) measurements were made in mature ash and beech stands growing on shallow soil over chalk near Winchester, Hampshire, UK. In addition measurements of gs and L∗ were made in the understorey layer in the ash stand, comprised mainly of dog's mercury, hazel and bramble. Automatic weather stations located (i) above the beech stand and (ii) at the understorey level (within the ash stand) provided hourly averages of weather variables. Changes in soil moisture deficit in both stands were determined from regular measurements made with a neutron probe. (2) Maximum values of gs (up to 0.3 mol m -2 s -1) were found at the top of the ash and beech canopies at the start of the day, while at the canopy base gs was about half of these values. At all canopy levels the value of gs was more closely associated with specific humidity deficit (at the time of measurement) than with any other weather variable, and there was no relationship between gs and soil mositure deficit or leaf water status, described by ψ1 and ψπ on the day of measurement. (3) Values of gs of the understorey plants were only half those of the tree species and changed less during the day. However, seasonal changes in gs of dog's mercury did seem to be associated with increased soil moisture deficit. (4) Estimates of L∗ in the ash and beech stands were made from leaf litter collections and partitioned into canopy layers using ratios determined by destructive sampling. L∗ of the beech stand was 5.3 and for the ash stand 2.7. L∗ of the understorey varied seasonally and rose to a peak of 3 in June falling gradually for the remainder of the summer period. (5) Hourly values of gs and ga in each stand for each canopy layer were scaled up to the canopy by using L∗ of the individual canopy layers (including the understorey level in the ash stand

  13. Initiation conditions for debris flows generated by runoff at Chalk Cliffs, central Colorado

    NASA Astrophysics Data System (ADS)

    Coe, Jeffrey A.; Kinner, David A.; Godt, Jonathan W.

    2008-04-01

    We have monitored initiation conditions for six debris flows between May 2004 and July 2006 in a 0.3 km 2 drainage basin at Chalk Cliffs; a band of hydrothermally-altered quartz monzonite in central Colorado. Debris flows were initiated by water runoff from colluvium and bedrock that entrained sediment from rills and channels with slopes ranging from about 14° to 45°. The availability of channel material is essentially unlimited because of thick channel fill and refilling following debris flows by rock fall and dry ravel processes. Rainfall exceeding I = 6.61( D) - 0.77 , where I is rainfall intensity (mm/h), and D is duration (h), was required for the initiation of debris flows in the drainage basin. The approximate minimum runoff discharge from the surface of bedrock required to initiate debris flows in the channels was 0.15 m 3/s. Colluvium in the basin was unsaturated immediately prior to (antecedent) and during debris flows. Antecedent, volumetric moisture levels in colluvium at depths of 1 cm and 29 cm ranged from 4-9%, and 4-7%, respectively. During debris flows, peak moisture levels in colluvium at depths of 1 cm and 29 cm ranged from 10-20%, and 4-12%, respectively. Channel sediment at a depth of 45 cm was unsaturated before and during debris flows; antecedent moisture ranged from 20-22%, and peak moisture ranged from 24-38%. Although we have no measurements from shallow rill or channel sediment, we infer that it was unsaturated before debris flows, and saturated by surface-water runoff during debris flows. Our results allow us to make the following general statements with regard to debris flows generated by runoff in semi-arid to arid mountainous regions: 1) high antecedent moisture levels in hillslope and channel sediment are not required for the initiation of debris flows by runoff, 2) locations of entrainment of sediment by successive runoff events can vary within a basin as a function of variations in the thickness of existing channel fill and the

  14. Lab Tracker and Copper Calculator

    MedlinePlus

    ... that you share this log of your treatment history with your physicians so that important trends in your health status can be noted. Patient Lab Tracker - Excel Version This format is downloadable to the Microsoft Excel program on your computer. Included are instructions and sample pages to assist ...

  15. State of the Lab Address

    ScienceCinema

    King, Alex

    2016-07-12

    In his third-annual State of the Lab address, Ames Laboratory Director Alex King called the past year one of "quiet but strong progress" and called for Ames Laboratory to continue to build on its strengths while responding to changing expectations for energy research.

  16. Safety Equipment in the Lab.

    ERIC Educational Resources Information Center

    Denham, Willard A.S.

    1964-01-01

    Findings of two recent surveys on safety equipment in laboratory facilities are presented. The first survey was a pilot study of emergency shower and eye wash equipment. This study was followed by a more comprehensive random survey of safety equipment in 2,820 labs. Among other findings, the surveys indicate that many plants are underequipped, or…

  17. Where Lab Tests Are Performed

    MedlinePlus

    ... labs also vary in complexity, the volume of tests performed, the technology utilized, and the number and type of professionals who conduct the testing . There are important differences among the various testing settings. This information will be useful in ... Proudly sponsored by ... Learn ...

  18. A Lab for All Reasons.

    ERIC Educational Resources Information Center

    Cronin-Jones, Linda L.

    1990-01-01

    Described is a demonstration science laboratory at the University of Florida. Discussed is laboratory design, including instructional space, lab stations, sink areas, safety areas, and a storage and distribution area. The impact of this type of design is cited. Diagrams and photographs are included. (CW)

  19. Fraud strikes top genome lab

    SciTech Connect

    Marshall, E.

    1996-11-08

    Francis Collins, head of NIH`s Human Genome Project has informed colleagues that a junior researcher in his lab facke data in five papers co-authored by Collins. This article describes the whole scenario, how it was discovered, and what the reprocussions are.

  20. Evaluating E-Labs' Experimentation

    ERIC Educational Resources Information Center

    Plaisent, Michel; Maguiraga, Lassana; Bernard, Prosper; Larhrib, Samir

    2004-01-01

    This communication discusses preliminary results on an experimentation of e-Learning with MIS students, mainly in order to cope with the logistics of lab organization. A learning management software was installed which changed completely the learning process, from content to logistics. Students have expressed their satisfaction with the e-Learning…

  1. A Simple, Successful Capacitor Lab

    ERIC Educational Resources Information Center

    Ennis, William

    2011-01-01

    Capacitors are a fundamental component of modern electronics. They appear in myriad devices and in an enormous range of sizes. Although our students are taught the function and analysis of capacitors, few have the opportunity to use them in our labs.

  2. Biodiversity Lab: Using Local Resources.

    ERIC Educational Resources Information Center

    Gillie, Lynn L.

    1997-01-01

    Examining living organisms in one's own backyard is a key first step toward appreciating the scope and importance of biological diversity throughout the world. The goals of this lab are to involve students in exploring the biodiversity around them, appreciating its scope, and asking questions of new organisms that they may never have noticed…

  3. A Lab for All Reasons.

    ERIC Educational Resources Information Center

    Cronin-Jones, Linda L.

    1990-01-01

    Described is a demonstration science laboratory at the University of Florida. Discussed is laboratory design, including instructional space, lab stations, sink areas, safety areas, and a storage and distribution area. The impact of this type of design is cited. Diagrams and photographs are included. (CW)

  4. A Simple, Successful Capacitor Lab

    ERIC Educational Resources Information Center

    Ennis, William

    2011-01-01

    Capacitors are a fundamental component of modern electronics. They appear in myriad devices and in an enormous range of sizes. Although our students are taught the function and analysis of capacitors, few have the opportunity to use them in our labs.

  5. Swanson in the US Lab

    NASA Image and Video Library

    2014-04-18

    ISS039-E-013158 (18 April 2014) --- In the U.S. lab Destiny on the Earth-orbiting International Space Station, Expedition 39 Flight Engineer Steve Swanson of NASA works on WRS condensate pumping, using the high flow water transfer pump.

  6. Assessment of undiscovered oil and gas resources of the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, Gulf Coast, 2010

    USGS Publications Warehouse

    Pearson, Krystal; Dubiel, R.F.; Pearson, O.N.; Pitman, J.K.

    2011-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 957 million barrels of undiscovered oil, 3.6 trillion cubic feet of undiscovered natural gas, and 363 million barrels of undiscovered natural gas liquids in the Austin Chalk and Tokio and Eutaw Formations in onshore lands and State waters of the Gulf Coast.

  7. Chalk Is Cheap: Nurturing Teachers in a Famine Culture Professional Starvation Is Gnawing Away At Teacher Motivation. Here Are Some Ways For Principals To Provide Needed Nutrition.

    ERIC Educational Resources Information Center

    Schmidt, Laurel

    2005-01-01

    Scarcity has been such a constant in education for so long that self-sufficient teachers routinely purchase classroom supplies at their own expense. Sometimes desperate measures are needed to obtain even the most basic equipment. I heard of a teacher whose chalkboard was so slick from years of use that it had become chalk-proof. Her first graders…

  8. Combined climatic and geological forcings on the spatio-temporal variability of piezometric levels in the chalk aquifer of Upper Normandy (France) at pluridecennal scale

    NASA Astrophysics Data System (ADS)

    Slimani, Smail; Massei, Nicolas; Mesquita, Johanna; Valdés, Danièle; Fournier, Matthieu; Laignel, Benoît; Dupont, Jean-Paul

    2009-12-01

    The temporal variability of water-level fluctuations in the chalk aquifer of Upper Normandy, France is constrained by natural climate fluctuations and is closely linked to the regional geological patterns. The chalk plateaus are covered with 5-50 m thick semi-permeable surficial formations; the thickness of the underlying chalk aquifer varies from 50 to 300 m. The relationship among climate oscillations, piezometric levels, and geologic structure were investigated by correlation, Fourier spectral, and continuous wavelet analyses of selected piezometric time-series data. Analysis focused on two piezometers located on the uplifted side of a major fault and two piezometers on the downthrown side. After generalization to other piezometers in the region, it was deduced that, in the downthrown compartments, a substantial aquifer and surficial formations thickness would imply a strong attenuation of annual variability, while multi-year variability is clearly expressed. Conversely, in the uplifted compartments, a thin layer of surficial formations and small thickness of the chalk authorizes strong variations on the annual mode with respect to the contribution of long-term climatic oscillations (multi-year variability). The results then demonstrated—and proposed a spatial determination of—the differential influence of geological patterns on the filtering of climate-induced oscillations in piezometric variability.

  9. Chalk Is Cheap: Nurturing Teachers in a Famine Culture Professional Starvation Is Gnawing Away At Teacher Motivation. Here Are Some Ways For Principals To Provide Needed Nutrition.

    ERIC Educational Resources Information Center

    Schmidt, Laurel

    2005-01-01

    Scarcity has been such a constant in education for so long that self-sufficient teachers routinely purchase classroom supplies at their own expense. Sometimes desperate measures are needed to obtain even the most basic equipment. I heard of a teacher whose chalkboard was so slick from years of use that it had become chalk-proof. Her first graders…

  10. Modelling of nitrate leaching from arable land into unsaturated soil and chalk 2. Model confirmation and application to agricultural and sewage sludge management

    NASA Astrophysics Data System (ADS)

    Andrews, R. J.; Lloyd, J. W.; Lerner, D. N.

    1997-12-01

    A layered deterministic N-leaching model, IMPACT, has been calibrated using data from two study sites on the unconfined Chalk aquilfer of East Anglia, UK. The model predicts nitrogen species movement resulting from the application of sewage sludges and fertilizers to arable land for different vegetation-soil-hydrogeological conditions. One site received sludge in the form of digested sewage cake (DSC) for the first time during the study period, whilst the other site had over 15 years history of liquid undigested sludge (LUS) applications at 3 year intervals. Site data included: 3-monthly concentration profiles at 0.3 m intervals to depths of up to 6 m for N-species and chloride; unsaturated potential measurements; water level and saturated groundwater solute concentrations, fertilizer and sludge input; daily recharge, and soil/chalk type and moisture content. The observed average movement rate for nitrate peaks in the Lower Chalk, measured at one site, was 0.2 m year -2. Leachate peaks were not observed annually but approximately every third year, being associated with large sludge applications and ploughing of grass crops. Significant correlation between observed and modelled nitrate profiles in soil and chalk were obtained which demonstrated applications. The relationship between crop demand, application times of fertilizers and sludge, nitrate availability and recharge was shown strongly to control the shape of nitrate profiles in the soil and chalk and the quantity of nitrate leached tochalk. The change in hydrogeological conditions at the soil-chalk contact and associated potential for denitrification was also shown to exert a significant control on the shape of the nitrate profile. Following calibration, different arable crop and sludge application regimes were examined for a 6 year period and ranked according to their nitrate leaching risk. Of the modelled cereal farming scenarios, the crop/sludge regime giving the least nitrate leaching was a late autumn

  11. Flexible HVAC System for Lab or Classroom.

    ERIC Educational Resources Information Center

    Friedan, Jonathan

    2001-01-01

    Discusses an effort to design a heating, ventilation, and air conditioning system flexible enough to accommodate an easy conversion of classrooms to laboratories and dry labs to wet labs. The design's energy efficiency and operations and maintenance are examined. (GR)

  12. Flexible HVAC System for Lab or Classroom.

    ERIC Educational Resources Information Center

    Friedan, Jonathan

    2001-01-01

    Discusses an effort to design a heating, ventilation, and air conditioning system flexible enough to accommodate an easy conversion of classrooms to laboratories and dry labs to wet labs. The design's energy efficiency and operations and maintenance are examined. (GR)

  13. Quantification of aquifer properties with surface nuclear magnetic resonance in the Platte River valley, central Nebraska, using a novel inversion method

    USGS Publications Warehouse

    Irons, Trevor P.; Hobza, Christopher M.; Steele, Gregory V.; Abraham, Jared D.; Cannia, James C.; Woodward, Duane D.

    2012-01-01

    Surface nuclear magnetic resonance, a noninvasive geophysical method, measures a signal directly related to the amount of water in the subsurface. This allows for low-cost quantitative estimates of hydraulic parameters. In practice, however, additional factors influence the signal, complicating interpretation. The U.S. Geological Survey, in cooperation with the Central Platte Natural Resources District, evaluated whether hydraulic parameters derived from surface nuclear magnetic resonance data could provide valuable input into groundwater models used for evaluating water-management practices. Two calibration sites in Dawson County, Nebraska, were chosen based on previous detailed hydrogeologic and geophysical investigations. At both sites, surface nuclear magnetic resonance data were collected, and derived parameters were compared with results from four constant-discharge aquifer tests previously conducted at those same sites. Additionally, borehole electromagnetic-induction flowmeter data were analyzed as a less-expensive surrogate for traditional aquifer tests. Building on recent work, a novel surface nuclear magnetic resonance modeling and inversion method was developed that incorporates electrical conductivity and effects due to magnetic-field inhomogeneities, both of which can have a substantial impact on the data. After comparing surface nuclear magnetic resonance inversions at the two calibration sites, the nuclear magnetic-resonance-derived parameters were compared with previously performed aquifer tests in the Central Platte Natural Resources District. This comparison served as a blind test for the developed method. The nuclear magnetic-resonance-derived aquifer parameters were in agreement with results of aquifer tests where the environmental noise allowed data collection and the aquifer test zones overlapped with the surface nuclear magnetic resonance testing. In some cases, the previously performed aquifer tests were not designed fully to characterize

  14. Updated version of an interim connection space LabPQR for spectral color reproduction: LabLab.

    PubMed

    Cao, Qian; Wan, Xiaoxia; Li, Junfeng; Liang, Jingxing

    2016-09-01

    In this paper, we propose a new interim connection space (ICS) called LabLab, which is an updated version of LabPQR, to overcome the drawback that the last three dimensions of LabPQR have no definite colorimetric meanings. We extended and improved the method by which the first three dimensions of LabPQR are deduced to obtain an ICS consisting of two sets of CIELAB values under different illuminants, and the reconstructed spectra from LabLab were obtained by minimizing colorimetric errors by means of the computational formula of the CIE-XYZ tristimulus values combined with least-squares best fit. The improvement obtained from the proposed method was tested to compress and reconstruct the reflectance spectra of the 1950 Natural Color System color chips and more than 50,000 ISO SOCS color patches as well as six multispectral images acquired by multispectral image acquisition systems using 1600 glossy Munsell color chips as training samples. The performance was evaluated by the mean values of color differences between the original and reconstructed spectra under the CIE 1931 standard colorimetric observer and the CIE standard illuminants D50, D55, D65, D75, F2, F7, F11, and A as well as five multichip white LED light sources. The mean and maximum values of the root mean square errors between the original and reconstructed spectra were also calculated. The experimental results show that the proposed three LabLab interim connection spaces significantly outperform principal component analysis, LabPQR, XYZLMS, Fairman-Brill, and LabRGB in colorimetric reconstruction accuracy at the cost of slight reduction of spectral reconstruction accuracy and illuminant independence of color differences of the suggested LabLab interim connection spaces outperform other interim connection spaces. In addition, the presented LabLab interim connection spaces could be quite compatible with the extensively used colorimetric management system since each dimension has definite colorimetric

  15. The Development of MSFC Usability Lab

    NASA Technical Reports Server (NTRS)

    Cheng, Yiwei; Richardson, Sally

    2010-01-01

    This conference poster reviews the development of the usability lab at Marshall Space Flight Center. The purpose of the lab was to integrate a fully functioning usability laboratory to provide a resource for future human factor assessments. and to implement preliminary usability testing on a MSFC website to validate the functionality of the lab.

  16. Experiences with Lab-Centric Instruction

    ERIC Educational Resources Information Center

    Titterton, Nathaniel; Lewis, Colleen M.; Clancy, Michael J.

    2010-01-01

    Lab-centric instruction emphasizes supervised, hands-on activities by substituting lab for lecture time. It combines a multitude of pedagogical techniques into the format of an extended, structured closed lab. We discuss the range of benefits for students, including increased staff interaction, frequent and varied self-assessments, integrated…

  17. The Effect of Microbial Activity on Flow and Transport of an Organic Contaminant in Naturally Fractured Chalk Cores

    NASA Astrophysics Data System (ADS)

    Arnon, S.; Adar, E.; Ronen, Z.; Yakirevich, A.; Nativ, R.

    2001-12-01

    Low-permeability rock formations, such as chalk, are being selected as hydrogeological barriers for waste disposal sites and industrial areas throughout the world. Many sites constructed on chalk formations have failed due to existing fractures. Subsurface natural or enhanced microbial activity is the main biological process that causes transformation of organic contaminants in groundwater. However, this beneficial activity may result in physical, chemical, geological and biological changes affecting the hydrological properties of the fractured domain. Whereas these effects have been extensively investigated in porous media, they are less familiar in fractured formations, the topic of this work. A set of experiments was designed to quantify 2-D flow distribution along a single fracture and to assess the effect of biodegradation on its hydraulic properties. The experiments were carried out using 20-cm diameter and 30-50-cm long chalk cores, each intersected by a single natural fracture. Flow across the fracture was defined through both direct measurements of the out flux under various (controlled) hydraulic gradients, and through 2-D multi-tracer tests. The 2-D-distribution of flow in the fracture was investigated by injecting four non-reactive tracers (fluorobenzoic acids), each along a different section of the fracture inlet. Similarly, the outflux was sampled from four vertically aligned segments at the fracture outlet. Tracer breakthrough curves, mixing ratios and fluxes were evaluated for quantitative assessment of the 2-D flow distribution within the fracture. Results from the flow experiments suggested deviation from a linear relationship between the flux and the hydraulic gradient for Reynolds numbers exceeding 8, probably due to the increase of inertial forces. In addition, although flow out of the fracture was evenly distributed along the fracture width, different mixing ratios of tracers in neighboring sections were observed probably due to hydrodynamic

  18. Real-time 4D ERT monitoring of river water intrusion into a former nuclear disposal site using a transient warping-mesh water table boundary (Invited)

    NASA Astrophysics Data System (ADS)

    Johnson, T.; Hammond, G. E.; Versteeg, R. J.; Zachara, J. M.

    2013-12-01

    The Hanford 300 Area, located adjacent to the Columbia River in south-central Washington, USA, is the site of former research and uranium fuel rod fabrication facilities. Waste disposal practices at site included discharging between 33 and 59 metric tons of uranium over a 40 year period into shallow infiltration galleries, resulting in persistent uranium contamination within the vadose and saturated zones. Uranium transport from the vadose zone to the saturated zone is intimately linked with water table fluctuations and river water intrusion driven by upstream dam operations. As river stage increases, the water table rises into the vadose zone and mobilizes contaminated pore water. At the same time, river water moves inland into the aquifer, and river water chemistry facilitates further mobilization by enabling uranium desorption from contaminated sediments. As river stage decreases, flow moves toward the river, ultimately discharging contaminated water at the river bed. River water specific conductance at the 300 Area varies around 0.018 S/m whereas groundwater specific conductance varies around 0.043 S/m. This contrast provides the opportunity to monitor groundwater/river water interaction by imaging changes in bulk conductivity within the saturated zone using time-lapse electrical resistivity tomography. Previous efforts have demonstrated this capability, but have also shown that disconnecting regularization constraints at the water table is critical for obtaining meaningful time-lapse images. Because the water table moves with time, the regularization constraints must also be transient to accommodate the water table boundary. This was previously accomplished with 2D time-lapse ERT imaging by using a finely discretized computational mesh within the water table interval, enabling a relatively smooth water table to be defined without modifying the mesh. However, in 3D this approach requires a computational mesh with an untenable number of elements. In order to

  19. New Features in ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Di Milia, G.; Luker, J.; Murray, S. S.

    2013-01-01

    The NASA Astrophysics Data System (ADS) has been working hard on updating its services and interfaces to better support our community's research needs. ADS Labs is a new interface built on the old tried-and-true ADS Abstract Databases, so all of ADS's content is available through it. In this presentation we highlight the new features that have been developed in ADS Labs over the last year: new recommendations, metrics, a citation tool and enhanced fulltext search. ADS Labs has long been providing article-level recommendations based on keyword similarity, co-readership and co-citation analysis of its corpus. We have now introduced personal recommendations, which provide a list of articles to be considered based on a individual user's readership history. A new metrics interface provides a summary of the basic impact indicators for a list of records. These include the total and normalized number of papers, citations, reads, and downloads. Also included are some of the popular indices such as the h, g and i10 index. The citation helper tool allows one to submit a set of records and obtain a list of top 10 papers which cite and/or are cited by papers in the original list (but which are not in it). The process closely resembles the network approach of establishing "friends of friends" via an analysis of the citation network. The full-text search service now covers more than 2.5 million documents, including all the major astronomy journals, as well as physics journals published by Springer, Elsevier, the American Physical Society, the American Geophysical Union, and all of the arXiv eprints. The full-text search interface interface allows users and librarians to dig deep and find words or phrases in the body of the indexed articles. ADS Labs is available at http://adslabs.org

  20. STS-115 Vitual Lab Training

    NASA Image and Video Library

    2005-06-07

    JSC2005-E-21192 (7 June 2005) --- Astronauts Christopher J. Ferguson (left), STS-115 pilot, and Daniel C. Burbank, mission specialist, use the virtual reality lab at the Johnson Space Center to train for their duties aboard the space shuttle. This type of computer interface, paired with virtual reality training hardware and software, helps to prepare the entire team for dealing with space station elements.