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Sample records for field lysimeters mathematische

  1. Mathematical modelling of deuterium transport in field lysimeters; Mathematische Modellierung des Deuteriumtransports in Freilandlysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Maloszewski, P.; Klotz, D.; Trimborn, P. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie; Maciejewski, S. [Polish Academy of Sciences, Gdansk (Poland). Inst. of Hydroengineering

    1999-02-01

    The results yielded by the Variable Flow Model (VFDM) permitted determining water flow velocities and degrees of dispersiveness. It transpired that it is not possible to isolate immobile water, which is to say that the available measuring and modelling data permit no conclusion as to whether or not the system contains immobile water. Comparison with the results obtained with the Dispersion Model (DM) showed that the simpler DM model yields tracer concentration curves in the system output that are almost as good as those of the more complicated VFDM model while entailing less work. The two models yield very similar calculations of lysimeter water content. [Deutsch] Die Ergebnisse der Modellierung mit dem Variable-Flow-Modell (VFDM) ermoeglichten die Bestimmung von Wassergeschwindigkeiten des Wassers und Dispersivitaeten. Es wurde dabei festgestellt, dass eine Abtrennung des immobilen Wassers nicht moeglich ist. D.h. es kann nicht auf Grund vorhandener Messdaten und der Modellierung entschieden werden, ob das System immobiles Wasser beinhaltet oder nicht. Ein Vergleich der Ergebnisse nach dem Variable-Flow- und dem Dispersions-Modell (DM) zeigte, dass das einfache Modell DM mit weniger Aufwand fast so gute Tracerkonzentrationskurven im Output aus dem System liefert wie das komplizierte Modell mit VFDM. Die berechneten Wassergehalte der Lysimeter nach beiden Modellierungen sind sehr aehnlich. (orig.)

  2. The Precision Field Lysimeter Concept

    Science.gov (United States)

    Fank, J.

    2009-04-01

    The understanding and interpretation of leaching processes have improved significantly during the past decades. Unlike laboratory experiments, which are mostly performed under very controlled conditions (e.g. homogeneous, uniform packing of pre-treated test material, saturated steady-state flow conditions, and controlled uniform hydraulic conditions), lysimeter experiments generally simulate actual field conditions. Lysimeters may be classified according to different criteria such as type of soil block used (monolithic or reconstructed), drainage (drainage by gravity or vacuum or a water table may be maintained), or weighing or non-weighing lysimeters. In 2004 experimental investigations have been set up to assess the impact of different farming systems on groundwater quality of the shallow floodplain aquifer of the river Mur in Wagna (Styria, Austria). The sediment is characterized by a thin layer (30 - 100 cm) of sandy Dystric Cambisol and underlying gravel and sand. Three precisely weighing equilibrium tension block lysimeters have been installed in agricultural test fields to compare water flow and solute transport under (i) organic farming, (ii) conventional low input farming and (iii) extensification by mulching grass. Specific monitoring equipment is used to reduce the well known shortcomings of lysimeter investigations: The lysimeter core is excavated as an undisturbed monolithic block (circular, 1 m2 surface area, 2 m depth) to prevent destruction of the natural soil structure, and pore system. Tracing experiments have been achieved to investigate the occurrence of artificial preferential flow and transport along the walls of the lysimeters. The results show that such effects can be neglected. Precisely weighing load cells are used to constantly determine the weight loss of the lysimeter due to evaporation and transpiration and to measure different forms of precipitation. The accuracy of the weighing apparatus is 0.05 kg, or 0.05 mm water equivalent

  3. Field Lysimeter Test Facility for protective barriers: Experimental plan

    International Nuclear Information System (INIS)

    Kirkham, R.R.; Gee, G.W.; Downs, J.L.

    1987-12-01

    This document was first written in October 1986 and has been used to guide the design of the Field Lysimeter Test Facility (FLTF) and to promote discussions between research and engineering staff regarding the selection of barrier treatments for inclusion in the FLTF. The construction of the lysimeter facility was completed June 28, 1987. This document describes the facility, the treatments placed in each lysimeter, types of measurements made in each lysimeter, and a brief discussion of project activities related to quality assurance, safety, and funding requirements. The treatment description and figures have been updated to reflect the lysimeter facility as constructed. 12 refs., 6 figs., 5 tabs

  4. Radionuclide release from low-level waste in field lysimeters

    International Nuclear Information System (INIS)

    Oblath, S.B.

    1986-01-01

    A field program has been in operation for 8 years at the Savannah River Plant (SRP) to determine the leaching/migration behavior of low-level radioactive waste using lysimeters. The lysimeters are soil-filled caissons containing well characterized wastes, with each lysimeter serving as a model of a shallow land burial trench. Sampling and analysis of percolate water and vegetation from the lysimeters provide a determination of the release rates of the radionuclides from the waste/soil system. Vegetative uptake appears to be a major pathway for migration. Fractional release rates from the waste/soil system are less than 0.01% per year. Waste-to-soil leach rates up to 10% per year have been determined by coring several of the lysimeters. The leaching of solidified wasteforms under unsaturated field conditions has agreed well with static, immersion leaching of the same type waste in the laboratory. However, releases from the waste/soil system in the lysimeter may be greater than predicted based on leaching alone, due to complexation of the radionuclides by other components leached from the wastes to form mobile, anionic species

  5. Results of field testing of waste forms using lysimeters

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.

    1988-01-01

    The purpose of the field testing task, using lysimeter arrays, is to expose samples of solidified resin waste to the actual physical, chemical, and microbiological conditions of disposal enviroment. Wastes used in the experiment include a mixture of synthetic organic ion exchange resins and a mixture of organic exchange resins and an inorganic zeolite. Solidification agents used to produce the 4.8-by 7.6-cm cylindrical waste forms used in the study were Portland Type I-II cement and Dow vinyl ester-styrene. Seven of these waste forms were stacked end-to-end and inserted into each lysimeter to provide a 1-L volume. There are 10 lysimeters, 5 at ORNL and 5 at ANL-E. Lysimeters used in this study were designed to be self-contained units which will be disposed at the termination of the 20-year study. Each is a 0.91-by 3.12-m right-circular cylinder divided into an upper compartment, which contains fill material, waste forms, and instrumentation, and an empty lower compartment, which collects leachate. Four lysimeters at each site are filled with soil, while a fifth (used as a control) is filled with inert silica oxide sand. Instrumentation within each lysimeter includes porous cup soil-water samplers and soil moisture/temperature probes. The probes are connected to an on-site data acquisition and storage system (DAS) which also collects data from a field meteorological station located at each site. 9 refs

  6. Status of SRNL radiological field lysimeter experiment-Year 1

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bagwell, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2013-10-01

    The Savannah River National Laboratory (SRNL) Radiological Field Lysimeter Experiment is a one-of-a-kind field facility designed to study radionuclide geochemical processes at a larger spatial scale (from grams to tens of kilograms sediment) and temporal scale (from months to 10 years) than is readily afforded through laboratory studies. The lysimeter facility is intended to capture the natural heterogeneity of moisture and temperature regimes in the vadose zone, the unsaturated subsurface region between the surface soil and the underlying aquifer. The 48 lysimeter columns, which contain various radionuclides (and stable iodine), were opened to rainfall infiltration on July 5, 2012. The objective of this report is to provide a status of the lysimeter facility operations and to compile data collected during FY13, including leachate volume, rainfall, and soil moisture and temperature in situ probe data. Radiological leachate data are not presented in this document but will be the subject of a separate document.1 Leachate samples were collected quarterly and shipped to Clemson University for radiological analyses. Rainfall, leachate volume, moisture and temperature probe data were collected continuously. During operations of the facility this year, there were four safety or technical concerns that required additional maintenance: 1) radioactivity was detected in one of the overflow bottles (captured water collected from the secondary containment that does not come in contact with the radiological source material); 2) rainwater accumulated within the sample-bottle storage sheds; 3) overflow containers collected more liquid than anticipated; and 4) significant spider infestation occurred in the sample-bottle storage sheds. To address the first three concerns, each of the lysimeter columns was re-plumbed to improve and to minimize the number of joint unions. To address the fourth concern regarding spiders, new sample-bottle water sheds were purchased and a pest control

  7. Results of field testing of radioactive waste forms using lysimeters

    International Nuclear Information System (INIS)

    McConnell, J.W., Jr.; Rogers, R.D.; Jastrow, J.D.; Wickliff, D.S.

    1992-01-01

    The Field Lysimeter Investigation: Low-Level Waste Data Base Development Program is obtaining informaiton on the performance of radioactive waste in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-II prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. In this paper, radionuclide releases from waste forms in the first six years of sampling are presented and discussed. Application of lysimeter data to use in performance assessment models is presented. Initial results from use of data in a performance assessment model are discussed

  8. Fate of diuron and linuron in a field lysimeter experiment.

    Science.gov (United States)

    Guzzella, L; Capri, E; Di Corcia, A; Barra Caracciolo, A; Giuliano, G

    2006-01-01

    The environmental fate of herbicides can be studied at different levels: in the lab with disturbed or undisturbed soil columns or in the field with suction cup lysimeters or soil enclosure lysimeters. A field lysimeter experiment with 10 soil enclosures was performed to evaluate the mass balance in different environmental compartments of the phenylurea herbicides diuron [3-(3,4-diclorophenyl)-1,1-dimethyl-urea] and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea]. After application on the agricultural soil, the herbicides were searched for in soil, pore water, and air samples. Soil and water samples were collected at different depths of the soil profile and analyzed to determine residual concentrations of both the parent compounds and of their main transformation products, to verify their persistence and their leaching capacity. Air volatilization was calculated using the theoretical profile shape method. The herbicides were detected only in the surface layer (0-10 cm) of soil. In this layer, diuron was reduced to 50% of its initial concentration at the end of the experiment, while linuron was still 70% present after 245 d. The main metabolites detected were DCPMU [3-(3,4-dichlorophenyl)-1-methylurea] and DCA (3,4-dichloroaniline). In soil pore water, diuron and linuron were detected at depths of 20 and 40 cm, although in very low concentrations. Therefore the leaching of these herbicides was quite low in this experiment. Moreover, volatilization losses were inconsequential. The calculated total mass balance showed a high persistence of linuron and diuron in the soil, a low mobility in soil pore water (less than 0.5% in leachate water), and a negligible volatilization effect. The application of the Pesticide Leaching Model (PELMO) showed similar low mobility of the chemicals in soil and water, but overestimated their volatilization and their degradation to the metabolite DCPMU. In conclusion, the use of soil enclosure lysimeters proved to be a good

  9. Field Lysimeter Test Facility status report IV: FY 1993

    International Nuclear Information System (INIS)

    Gee, G.W.; Felmy, D.G.; Ritter, J.C.; Campbell, M.D.; Downs, J.L.; Fayer, M.J.; Kirkham, R.R.; Link, S.O.

    1993-10-01

    At the U.S. Department of Energy's Hanford Site near Richland, Washington, a unique facility, the Field Lysimeter Test Facility (FLTF) is used to measure drainage from and water storage in soil covers. Drainage has ranged from near zero amounts to more than 50% of the applied water, with the amount depending on vegetative cover and soil type. Drainage occurred from lysimeters with coarse soils and gravel covers, but did not occur from capillary barrier-type lysimeters (1.5 m silt loam soil over coarse sands and gravels) except under the most extreme condition tested. For capillary barriers that were irrigated and kept vegetation-free (bare surface), no drainage occurred in 5 of the past 6 years. However, this past year (1992--1993) a record snowfall of 1,425 mm occurred and water storage in the irrigated, bare-surfaced capillary barriers exceeded 500 mm resulting in drainage of more than 30 mm from these barriers. In contrast, capillary barriers, covered with native vegetation (i.e., shrubs and grasses) did not drain under any climatic condition (with or without irrigation). In FY 1994, the FLTF treatments will be increased from 11 to 17 with the addition of materials that will simulate portions of a prototype barrier planned for construction in 1994 at the Hanford Site. The 17 FLTF treatments are designed to test the expected range of surface soil, vegetation, and climatic conditions encountered at the Hanford Site and will assist in evaluating final surface barrier designs for a waste disposal facility

  10. Unsaturated zone moisture and vapor movement induced by temperature variations in asphalt barrier field lysimeters

    International Nuclear Information System (INIS)

    Holford, D.J.; Fayer, M.J.

    1990-08-01

    Protective barriers are being considered for use at the Hanford Site to enhance the isolation of radioactive wastes from water, plant, and animal intrusion. Lysimeters were constructed to evaluate the performance of asphalt barrier formulations under natural environmental conditions. These lysimeters were constructed of 1.7-m lengths of PVC pipe that have a diameter of 30 cm. The lysimeters were filled with layers of gravel, coarse sand, and asphalt. The sand and gravel placed under the asphalt barrier were wet when installed. TOUGH was used to conduct simulations to assess the effect of temperature variations on moisture and vapor movement beneath the asphalt layer in field test lysimeters. All variables in TOUGH were converted to double precision so that simulations could be run on a Sun-4 UNIX workstation. A radially symmetric grid was used to simulate the lysimeter. 8 refs., 9 figs

  11. The Field Lysimeter Test Facility (FLTF) at the Hanford Site: Installation and initial tests

    International Nuclear Information System (INIS)

    Gee, G.W.; Kirkham, R.R.; Downs, J.L.; Campbell, M.D.

    1989-02-01

    The objectives of this program are to test barrier design concepts and to demonstrate a barrier design that meets established performance criteria for use in isolating wastes disposed of near-surface at the Hanford Site. Specifically, the program is designed to assess how well the barriers perform in controlling biointrusion, water infiltration, and erosion, as well as evaluating interactions between environmental variables and design factors of the barriers. To assess barrier performance and design with respect to infiltration control, field lysimeters and small- and large-scale field plots are planned to test the performance of specific barrier designs under actual and modified (enhanced precipitation) climatic conditions. The Field Lysimeter Test Facility (FLTF) is located in the 600 Area of the Hanford Site just east of the 200 West Area and adjacent to the Hanford Meteorological Station. The FLTF data will be used to assess the effectiveness of selected protective barrier configurations in controlling water infiltration. The facility consists of 14 drainage lysimeters (2 m dia x 3 m deep) and four precision weighing lysimeters (1.5 m x 1.5 m x 1.7 m deep). The lysimeters are buried at grade and aligned in a parallel configuration, with nine lysimeters on each side of an underground instrument chamber. The lysimeters were filled with materials to simulate a multilayer protective barrier system. Data gathered from the FLTF will be used to compare key barrier components and to calibrate and test models for predicting long-term barrier performance

  12. Field lysimeter studies for performance evaluation of grouted Hanford defense wastes

    International Nuclear Information System (INIS)

    Last, G.V.; Serne, R.J.; LeGore, V.L.

    1995-02-01

    The Grout Waste Test Facility (GWTF) consisted of four large field lysimeters designed to test the leaching and migration rates of grout-solidified low-level radioactive wastes generated by Hanford Site operations. Each lysimeter was an 8-m-deep by 2-media closed-bottom caisson that was placed in the ground such that the uppermost rim remained just above grade. Two of these lysimeters were used; the other two remained empty. The two lysimeters that were used (A-1 and B-1) were backfilled with a two-layer soil profile representative of the proposed grout disposal site. The proposed grout disposal site (termed the Grout Treatment Facility Landfill) is located immediately east of the Hanford Site's 200 East Area. This soil profile consisted of a coarse sand into which the grout waste forms were placed and covered by 4 m of a very fine sand. The A-1 lysimeter was backfilled in March 1985, with a grout-solidified phosphate/sulfate liquid waste from N Reactor decontamination and ion exchange resin regeneration. The B-1 lysimeter was backfilled in September 1985 and received a grout-solidified simulated cladding removal waste representative of waste generated from fuel reprocessing operations at the head end of the Plutonium Uranium Extraction (PUREX) plant. Routine monitoring and leachate collection activities were conducted for over three years, terminating in January 1989. Drainage was collected sporadically between January 1989 and December 1992. Decontamination and decommissioning of these lysimeters during the summer of 1994, confirmed the presence of a 15 to 20-cm-long hairline crack in one of the bottom plate welds. This report discusses the design and construction of the GWTF, presents the routine data collected from this facility through January 1989 and subsequent data collected sporadically between 1989 and 1993, and provides a brief discussion concerning preliminary interpretation of the results

  13. Mathematical modelling of deuterium transport in field lysimeters

    International Nuclear Information System (INIS)

    Maloszewski, P.; Klotz, D.; Trimborn, P.; Maciejewski, S.

    1999-01-01

    The results yielded by the Variable Flow Model (VFDM) permitted determining water flow velocities and degrees of dispersiveness. It transpired that it is not possible to isolate immobile water, which is to say that the available measuring and modelling data permit no conclusion as to whether or not the system contains immobile water. Comparison with the results obtained with the Dispersion Model (DM) showed that the simpler DM model yields tracer concentration curves in the system output that are almost as good as those of the more complicated VFDM model while entailing less work. The two models yield very similar calculations of lysimeter water content [de

  14. Distribution of 15N fertilizer in field-lysimeters sown with garlic (Allium sativum) and foxtail millet (Setaria italica)

    International Nuclear Information System (INIS)

    Lazzari, M.A.

    1982-01-01

    We examined the distribution of residual 15 N and its uptake by a foxtail millet crop grown in field lysimeters following a previous garlic crop fertilized with either 15 N-urea or 15 N-ammonium sulphate. Garlic apparently removed more N from the lysimeters treated with urea-N than from those treated with (NH 4 ) 2 SO 4 . Fertilizer-N in the lysimeters was similar (ca. 32% of original) following millet harvest. About 16 per cent of both fertilizers in the lysimeters was removed by the millet. (orig.)

  15. Distribution of /sup 15/N fertilizer in field-lysimeters sown with garlic (Allium sativum) and foxtail millet (Setaria italica)

    Energy Technology Data Exchange (ETDEWEB)

    Lazzari, M.A. (Universidad Nacional del Sur, Bahia Blanca (Argentina). Dept. de Ciencas Agrarias)

    1982-01-01

    We examined the distribution of residual /sup 15/N and its uptake by a foxtail millet crop grown in field lysimeters following a previous garlic crop fertilized with either /sup 15/N-urea or /sup 15/N-ammonium sulphate. Garlic apparently removed more N from the lysimeters treated with urea-N than from those treated with (NH/sub 4/)/sub 2/SO/sub 4/. Fertilizer-N in the lysimeters was similar (ca. 32% of original) following millet harvest. About 16 per cent of both fertilizers in the lysimeters was removed by the millet.

  16. Field lysimeter facility for evaluating the performance of commercial solidified low-level waste

    International Nuclear Information System (INIS)

    Walter, M.B.; Graham, M.J.; Gee, G.W.

    1984-11-01

    Analyzing the potential migration of radionuclides from sites containing solid low-level wastes requires knowledge of contaminant concentrations in the soil solution surrounding the waste. This soil solution concentration is generally referred to as the source term and is determined by such factors as the concentration of radionuclides in the solid waste, the rate of leachate formation, the concentration of dissolved species in the leachate, any solubility reactions occurring when the leachate contacts the soil, and the rate of water flow in the soil surrounding the waste. A field lysimeter facility established at the Hanford site is being used to determine typical source terms in arid climates for commercial low-level wastes solidifed with cement, Dow polymer (vinyl ester-styrene), and bitumen. The field lysimeter facility consists of 10, 3-m-deep by 1.8-m-dia closed-bottom lysimeters situated around a 4-m-deep by 4-m-dia central instrument caisson. Commercial cement and Dow polymer waste samples were removed from 210-L drums and placed in 8 of the lysimeters. Two bitumen samples are planned to be emplaced in the facility's remaining 2 lysimeters during 1984. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste. Suction candles (ceramic cups) placed around the waste forms will be used to periodically collect soil-water samples for chemical analysis. Meteorological data, soil moisture content, and soil temperature are automatically monitored at the facility. Characterization of the soils and waste forms have been partially completed. These data consist of moisture release characteristics, particle-size distribution, and distributions and concentrations of radionuclides in the waste forms. 11 references, 12 figures, 5 tables

  17. Results after ten years of field testing low-level radioactive waste forms using lysimeters

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.; Jastrow, J.D.; Sanford, W.E.; Larsen, I.L.; Sullivan, T.M.

    1995-01-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms. Ion-exchange resins from a commercial nuclear power station were solidified into waste forms using portland cement and vinyl esterstyrene. These waste forms are being tested to: (a) obtain information on performance of waste forms in typical disposal environments, (b) compare field results with bench leach studies, (c) develop a low-level waste data base for use in performance assessment source term calculations, and (d) apply the DUST computer code to compare predicted cumulative release to actual field data. The program, funded by the Nuclear Regulatory Commission (NRC), includes observed radionuclide releases from waste forms in field lysimeters. The purpose of this paper is to present the experimental results of two lysimeter arrays over 10 years of operation, and to compare those results to bench test results and to DUST code predicted releases. Further analysis of soil cores taken to define the observed upward migration of radionuclides in one lysimeter is also presented

  18. Field Lysimeter Test Facility: Second year (FY 1989) test results

    International Nuclear Information System (INIS)

    Campbell, M.D.; Gee, G.W.; Kanyid, M.J.; Rockhold, M.L.

    1990-04-01

    The Record of Decision associated with the Hanford Defense Waste Environmental Impact Statement (53 FR 12449-53) commits to an evaluation of the use of protective barriers placed over near-surface wastes. The barrier must protect against wind and water erosion and limit plant and animal intrusion and infiltration of water. Successful conclusion of this program will yield the necessary protective barrier design for near-surface waste isolation. This report presents results from the second year of tests at the FLTF. The primary objective of testing protective barriers at the FLTF was to measure the water budgets within the various barriers and assess the effectiveness of their designs in limiting water intrusion into the zone beneath each barrier. Information obtained from these measurements is intended for use in refining barrier designs. Four elements of water budget were measured during the year: precipitation, evaporation, storage, and drainage. Run-off, which is a fifth element of a complete water budget, was made negligible by a lip on the lysimeters that protrudes 5 cm above the soil surface to prevent run-off. A secondary objective of testing protective barriers at the FLTF was to refine procedures and equipment to support data collection for verification of the computer model needed for long-term projections of barrier performance. 6 refs

  19. Moderne mathematische Methoden der Physik

    CERN Document Server

    Goldhorn, Karl-Heinz; Kraus, Margarita

    2010-01-01

    Der große Vorzug dieses Lehrbuchs liegt in seiner kompromisslosen Konzentration auf begriffliche Klarheit bei bewusstem Verzicht auf für Physiker irrelevante Details. Es richtet sich u.a. an Studierende von Master-, Aufbau-, Graduierten- und Promotionsstudiengängen im Bereich der theoretischen und mathematischen Physik. Die Auswahl des Stoffes deckt ein breites Spektrum mathematischer Konzepte und Methoden ab, die für die heutige Physik relevant sind. Dieser zweite Band konzentriert sich dabei auf mathematische Grundlagen der Quantenmechanik: Unbeschränkte Operatoren im Hilbertraum, Spektraltheorie sowie Symmetriegruppen und ihre Darstellungen mit besonderem Augenmerk auf Rotations- und Lorentzgruppe.

  20. Results after nine years of field testing low-level radioactive waste forms using lysimeters

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.; Jastrow, J.D.; Sanford, W.E.; Sullivan, T.M.

    1995-01-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms. Ion-exchange resins from a nuclear power station were solidified into waste forms using Portland cement and vinyl ester-styrene. These waste forms are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. This paper reviews radionuclide releases from those waste forms in the first 9 years of sampling. Included is a discussion of the recently discovered upward migration of radionuclides. Also, lysimeter data are applied to a performance assessment source term model, and initial results are presented

  1. Field Lysimeter Test Facility: Protective barrier test results (FY 1990, the third year)

    International Nuclear Information System (INIS)

    Campbell, M.D.; Gee, G.W.

    1990-11-01

    The Field Lysimeter Test Facility (FLTF) was constructed to test protective barriers for isolating low-level radioactive and hazardous wastes from the biosphere. Protective barriers are specially configured earth materials placed over near-surface wastes to prevent intrusion of water, plants, and animals. Low-level radioactive waste is stored in near-surface repositories at the Hanford Site and can be transported into the biosphere by water, plants, and animals. The purpose of the FLTF is to measure water balance within barriers as precipitation is partitioned to evaporation (including transpiration), storage, and drainage. Runoff was prevented by raised edges on the lysimeters. Water balance in protective barriers depends on the water-holding capacity of the soil, the gradient of a potential, and the conductivity of the underlying capillary barrier. Current barrier design uses soil with a high water storage capacity and a capillary barrier underlying the soil to increase its water storage capacity. This increased storage capacity is to hold water, which would normally drain, near the the surface where evaporation can cycle it back to the atmosphere. 7 refs., 23 figs., 5 tabs

  2. Field lysimeter investigations: Low-level waste data base development program for fiscal year 1996. Annual report; Volume 9

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.; Larsen, I.L.; Sanford, W.E.; Sullivan, T.M.; Fuhrmann, M.

    1997-08-01

    A data base development program, funded by the US Nuclear Regulatory Commission, is (a) studying the degradation effects in organic ion-exchange resins caused by radiation, (b) examining the adequacy of test procedures recommended in the Branch Technical Position on Waste Form to meet the requirements of 10 CFR 61 using solidified ion-exchange resins, (c) obtaining performance information on solidified ion-exchange resins in a disposal environment, and (d) determining the condition of liners used to dispose the ion-exchange resins. During the field testing experiments, both portland type 1--2 cement and Dow vinyl ester-styrene waste form samples were tested in lysimeter arrays located at Argonne National Laboratory-East (ANL-E) in Illinois and at Oak Ridge National Laboratory (ORNL). The study was designed to provide continuous data on nuclide release and movement, as well as environmental conditions, over an extended period. Those experiments have been shut down and are to be exhumed. This report discusses the plans for removal, sampling, and analysis of waste form and soil cores from the lysimeters. Results of partition coefficient determinations are presented, as well as application of a source term computer code using those coefficients to predict the lysimeter results. A study of radionuclide-containing colloids associated with the leachate waters removed from these lysimeters is described. An update of upward migration of radionuclides in the sand-filled lysimeter at ORNL is included

  3. Evaluating lysimeter drainage against soil deep percolation modeled with profile soil moisture, field tracer propagation, and lab measured soil hydraulic properties

    DEFF Research Database (Denmark)

    Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø

    them have been reported. To compare among methods, one year of four large-scale lysimeters drainage (D) was evaluated against modeled soil deep percolation using either profile soil moisture, bromide breakthrough curves from suction cups, or measured soil hydraulic properties in the laboratory....... Measured volumetric soil water content (q) was 3-4% higher inside lysimeters than in the field probably due to a zero tension lower boundary condition inside lysimeters. D from soil hydraulic properties measured in the laboratory resulted in a 15% higher evapotranspiration and 12% lower drainage...... predictions than the model calibrated with field measured q. Bromide (Br) breakthrough curves indicated high variability between lysimeters and field suction cups with mean Br velocities at first arrival time of 110 and 33 mm/d, respectively. D was 520 mm/yr with lysimeters, 613 mm/yr with the calibrated...

  4. Examination plan for the soils and low-level radioactive waste forms of the NRC field testing lysimeters

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.; Jastrow, J.D.

    1996-01-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms. These experiments were recently shut down and have been examined in accordance with a detailed waste form and soil sampling plan. Ion-exchange resins from a commercial nuclear power station were solidified into waste forms using portland cement and vinyl ester-styrene. These waste forms were tested to (a) obtain information on performance of waste forms in typical disposal environments, (b) compare field results with bench leach studies, (c) develop a low-level waste data base for use in performance assessment source term calculations, and (d) apply the DUST computer code to compare predicted cumulative release to actual field data. The program, funded by the Nuclear Regulatory Commission (NRC), includes observed radionuclide releases from waste forms at two test sites over 10 years of successful operation. Lysimeters are ideal systems for obtaining actual field test data because, when properly designed and operated, they can be used to isolate soil and waste systems under actual environmental conditions. The purpose of this paper is to present the experimental plan for the examination of the waste forms and soils of the two lysimeter arrays, which have now been shut down. Vertical soil cores have been taken from the soil columns and will be analyzed with radiochemistry to define movement of radionuclides after release from the waste forms. A comparison is made of the DUST-predicted releases to those previously determined and reported from the lysimeter leachate analyses. That comparison uses new partition coefficients (Kd) recently obtained from laboratory analysis of the lysimeter soils and sand. Those DUST code results also will be compared to actual radionuclide movements through the soil columns as determined from soil core analysis

  5. Plant-specific responses to zinc contamination in a semi-field lysimeter and on hydroponics

    International Nuclear Information System (INIS)

    Bernhard, Roland; Verkleij, Jos A.C.; Nelissen, Hans J.M.; Vink, Jos P.M.

    2005-01-01

    The species Agrostis stolonifera, Brassica napus and Trifolium repens representing different ecological strategies, were selected to study the effect of Zn contamination on Zn tolerance, uptake and accumulation patterns. Parallel tests were carried out with increasing concentrations of Zn in a semi-field lysimeter and hydroponics in the climate chamber. A significant reduction in biomass production or root length and an increase in shoot Zn concentration was observed for all species at increasing external Zn concentrations. However, shoot biomass production, Zn tolerance and Zn accumulation differed significantly among the tested species. The results in both experimental set-ups were quite similar concerning Zn tolerance and accumulation and improved the validity of the findings. The rather specific responses of the different plant species to Zn contamination interfere with the more generic approach used in risk assessment studies. Maximum amounts of Zn in shoot are not likely to cause a risk to herbivores. - Effects of Zn contamination showed different responses in uptake and accumulation patterns of site-specific plant species, which were similar in a semi-field experiment and under controlled conditions

  6. Plant-specific responses to zinc contamination in a semi-field lysimeter and on hydroponics

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard, Roland [Department of Ecology and Physiology of Plants, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam (Netherlands); Verkleij, Jos A.C. [Department of Ecology and Physiology of Plants, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam (Netherlands)]. E-mail: jos.verkleij@falw.vu.nl; Nelissen, Hans J.M. [Department of Ecology and Physiology of Plants, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam (Netherlands); Vink, Jos P.M. [Department of Chemistry and Ecotoxicology, RIZA, PO Box 17, NL-8200 AA Lelystad (Netherlands)

    2005-11-15

    The species Agrostis stolonifera, Brassica napus and Trifolium repens representing different ecological strategies, were selected to study the effect of Zn contamination on Zn tolerance, uptake and accumulation patterns. Parallel tests were carried out with increasing concentrations of Zn in a semi-field lysimeter and hydroponics in the climate chamber. A significant reduction in biomass production or root length and an increase in shoot Zn concentration was observed for all species at increasing external Zn concentrations. However, shoot biomass production, Zn tolerance and Zn accumulation differed significantly among the tested species. The results in both experimental set-ups were quite similar concerning Zn tolerance and accumulation and improved the validity of the findings. The rather specific responses of the different plant species to Zn contamination interfere with the more generic approach used in risk assessment studies. Maximum amounts of Zn in shoot are not likely to cause a risk to herbivores. - Effects of Zn contamination showed different responses in uptake and accumulation patterns of site-specific plant species, which were similar in a semi-field experiment and under controlled conditions.

  7. Radionuclide field lysimeter experiment (RadFLEx): geochemical and hydrological data for SRS performance assessments

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Powell, B. [Clemson Univ., SC (United States); Barber, K. [Clemson Univ., SC (United States); Devol, T. [Clemson Univ., SC (United States); Dixon, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Erdmann, B. [Clemson Univ., SC (United States); Maloubier, M. [Clemson Univ., SC (United States); Martinez, N. [Clemson Univ., SC (United States); Montgomery, D. [Clemson Univ., SC (United States); Peruski, K. [Clemson Univ., SC (United States); Roberts, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Witmer, M. [Clemson Univ., SC (United States)

    2017-12-12

    The SRNL Radiological Field Lysimeter Experiment (RadFLEx) is a one-of-a-kind test bed facility designed to study radionuclide geochemical processes in the Savannah River Site (SRS) vadose zone at a larger spatial scale (from grams to tens of kilograms of sediment) and temporal scale (from months to decade) than is readily afforded through laboratory studies. RadFLEx is a decade-long project that was initiated on July 5, 2012 and is funded by six different sources. The objective of this status report is as follows: 1) to report findings to date that have an impact on SRS performance assessment (PA) calculations, and 2) to provide performance metrics of the RadFLEx program. The PA results are focused on measurements of transport parameters, such as distribution coefficients (Kd values), solubility, and unsaturated flow values. As this is an interim report, additional information from subsequent research may influence our interpretation of current results. Research related to basic understanding of radionuclide geochemistry in these vadose zone soils and other source terms are not described here but are referenced for the interested reader.

  8. Studies on development of experimental system for trial manufacture of semi-field scale lysimeter

    International Nuclear Information System (INIS)

    Kamada, Hiroshi; Yukawa, Masae; Watabe, Teruhisa; Tanaka, Hirobumi; Ohwaku, Keiichi

    1978-01-01

    Because of difficulties in conduct of in situ experiments using the radiotracer method for this purpose, it is necessary to develope the technique on utilization of the results obtained by the laboratory works to resolve phenomenon in the actual environment. For this kind of extrapolation, optimum size of experimental model, designed as large as reasonable in scale to simulate the actual environment (defined as the term, 'semi-field scale experimental model' for convenience) was investigated. For this kind of extrapolation, optimum size of experimental model, designed as large as reasonable in scale to simulate the actual environment (defined as the term, 'semi-field scale experimental model' for convenience) was investigated. For this object, following experiments are especially conducted. The effects of vegetation to the mobility of transition elements in the surface layer of soil was studied by Wagner pot experiment. The vertical movement pattern of radionuclides in the deeper layer in the ground, especially transfer of long-lived-nuclides from soil into water, was investigated using radioactivity survey data of fallout. These results indicated the importance of information on the behaviour of contaminants in 'surface soil', 'Intermediate zone', 'capillary zone' and 'aquifer'. Therefore, an experimental mode, consisted of above four parts, was designed. The apparatus would include several substructures; an artificial rainfall apparatus, the Lysimeter, and receptive basin and so on. A regulation system for the fluctuation of hydraulic gradient in the aquifer would be also required. In order to get information on the above four parts of ground constitutions altogether, approximately 4 - 12 m depth was recommended for the model. (author)

  9. Lysimeter Research Group - A scientific community network for lysimeter research

    Science.gov (United States)

    Cepuder, Peter; Nolz, Reinhard; Bohner, Andreas; Baumgarten, Andreas; Klammler, Gernot; Murer, Erwin; Wimmer, Bernhard

    2014-05-01

    A lysimeter is a vessel that isolates a volume of soil between ground surface and a certain depth, and includes a sampling device for percolating water at its bottom. Lysimeters are traditionally used to study water and solute transport in the soil. Equipped with a weighing system, soil water sensors and temperature sensors, lysimeters are valuable instruments to investigate hydrological processes in the system soil-plant-atmosphere, especially fluxes across its boundary layers, e.g. infiltration, evapotranspiration and deep drainage. Modern lysimeter facilities measure water balance components with high precision and high temporal resolution. Hence, lysimeters are used in various research disciplines - such as hydrology, hydrogeology, soil science, agriculture, forestry, and climate change studies - to investigate hydrological, chemical and biological processes in the soil. The Lysimeter Research Group (LRG) was established in 1992 as a registered nonprofit association with free membership (ZVR number: 806128239, Austria). It is organized as an executive board with an international scientific steering committee. In the beginning the LRG focused mainly on nitrate contamination in Austria and its neighboring countries. Today the main intention of the LRG is to advance interdisciplinary exchange of information between researchers and users working in the field of lysimetry on an international level. The LRG also aims for the dissemination of scientific knowledge to the public and the support of decision makers. Main activities are the organization of a lysimeter conference every two years in Raumberg-Gumpenstein (Styria, Austria), the organization of excursions to lysimeter stations and related research sites around Europe, and the maintenance of a website (www.lysimeter.at). The website contains useful information about numerous European lysimeter stations regarding their infrastructure, instrumentation and operation, as well as related links and references which

  10. Hydroponics versus field lysimeter studies of urea, ammonium and nitrate uptake by oilseed rape (Brassica napus L.).

    Science.gov (United States)

    Arkoun, Mustapha; Sarda, Xavier; Jannin, Laëtitia; Laîné, Philippe; Etienne, Philippe; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain

    2012-09-01

    N-fertilizer use efficiencies are affected by their chemical composition and suffer from potential N-losses by volatilization. In a field lysimeter experiment, (15)N-labelled fertilizers were used to follow N uptake by Brassica napus L. and assess N-losses by volatilization. Use of urea with NBPT (urease inhibitor) showed the best efficiency with the lowest N losses (8% of N applied compared with 25% with urea alone). Plants receiving ammonium sulphate, had similar yield achieved through a better N mobilization from vegetative tissues to the seeds, despite a lower N uptake resulting from a higher volatilization (43% of applied N). Amounts of (15)N in the plant were also higher when plants were fertilized with ammonium nitrate but N-losses reached 23% of applied N. In parallel, hydroponic experiments showed a deleterious effect of ammonium and urea on the growth of oilseed rape. This was alleviated by the nitrate supply, which was preferentially taken up. B. napus was also characterized by a very low potential for urea uptake. BnDUR3 and BnAMT1, encoding urea and ammonium transporters, were up-regulated by urea, suggesting that urea-grown plants suffered from nitrogen deficiency. The results also suggested a role for nitrate as a signal for the expression of BnDUR3, in addition to its role as a major nutrient. Overall, the results of the hydroponic study showed that urea itself does not contribute significantly to the N nutrition of oilseed rape. Moreover, it may contribute indirectly since a better use efficiency for urea fertilizer, which was further increased by the application of a urease inhibitor, was observed in the lysimeter study.

  11. A lysimeter experiment to investigate the leaching of veterinary antibiotics through a clay soil and comparison with field data

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Paul [Cranfield Centre for EcoChemistry, Cranfield University, Shardlow Hall, Shardlow, Derby DE72 2GN (United Kingdom)]. E-mail: paul.kay@adas.co.uk; Blackwell, Paul A. [Cranfield Centre for EcoChemistry, Cranfield University, Shardlow Hall, Shardlow, Derby DE72 2GN (United Kingdom); Boxall, Alistair B.A. [Cranfield Centre for EcoChemistry, Cranfield University, Shardlow Hall, Shardlow, Derby DE72 2GN (United Kingdom)

    2005-03-01

    Pharmaceuticals used in livestock production may be present in manure and slurry as the parent compound and/or metabolites. The environment may therefore be exposed to these substances due to the application of organic fertilisers to agricultural land or deposition by grazing livestock. For other groups of substances that are applied to land (e.g. pesticides), preferential flow in clay soils has been identified as an extremely important mechanism by which surface water pollution can occur. This lysimeter study was therefore performed to investigate the fate of three antibiotics from the sulphonamide, tetracycline and macrolide groups in a clay soil. Only sulphachloropyridazine was detected in leachate and soil analysis at the end of the experiment showed that almost no antibiotic residues remained. These data were analysed alongside field data for the same compounds to show that soil tillage which breaks the connectivity of macropores formed over the summer months, prior to slurry application, significantly reduces chemical mobility. - This paper describes one of the first studies to investigate the fate of veterinary medicines in cracking clay soils.

  12. A lysimeter experiment to investigate the leaching of veterinary antibiotics through a clay soil and comparison with field data

    International Nuclear Information System (INIS)

    Kay, Paul; Blackwell, Paul A.; Boxall, Alistair B.A.

    2005-01-01

    Pharmaceuticals used in livestock production may be present in manure and slurry as the parent compound and/or metabolites. The environment may therefore be exposed to these substances due to the application of organic fertilisers to agricultural land or deposition by grazing livestock. For other groups of substances that are applied to land (e.g. pesticides), preferential flow in clay soils has been identified as an extremely important mechanism by which surface water pollution can occur. This lysimeter study was therefore performed to investigate the fate of three antibiotics from the sulphonamide, tetracycline and macrolide groups in a clay soil. Only sulphachloropyridazine was detected in leachate and soil analysis at the end of the experiment showed that almost no antibiotic residues remained. These data were analysed alongside field data for the same compounds to show that soil tillage which breaks the connectivity of macropores formed over the summer months, prior to slurry application, significantly reduces chemical mobility. - This paper describes one of the first studies to investigate the fate of veterinary medicines in cracking clay soils

  13. Activated carbon amendment to sequester PAHs in contaminated soil: a lysimeter field trial.

    Science.gov (United States)

    Hale, Sarah E; Elmquist, Marie; Brändli, Rahel; Hartnik, Thomas; Jakob, Lena; Henriksen, Thomas; Werner, David; Cornelissen, Gerard

    2012-04-01

    Activated carbon (AC) amendment is an innovative method for the in situ remediation of contaminated soils. A field-scale AC amendment of either 2% powder or granular AC (PAC and GAC) to a PAH contaminated soil was carried out in Norway. The PAH concentration in drainage water from the field plot was measured with a direct solvent extraction and by deploying polyoxymethylene (POM) passive samplers. In addition, POM samplers were dug directly in the AC amended and unamended soil in order to monitor the reduction in free aqueous PAH concentrations in the soil pore water. The total PAH concentration in the drainage water, measured by direct solvent extraction of the water, was reduced by 14% for the PAC amendment and by 59% for GAC, 12 months after amendment. Measurements carried out with POM showed a reduction of 93% for PAC and 56% for GAC. The free aqueous PAH concentration in soil pore water was reduced 93% and 76%, 17 and 28 months after PAC amendment, compared to 84% and 69% for GAC. PAC, in contrast to GAC, was more effective for reducing freely dissolved concentrations than total dissolved ones. This could tentatively be explained by leaching of microscopic AC particles from PAC. Secondary chemical effects of the AC amendment were monitored by considering concentration changes in dissolved organic carbon (DOC) and nutrients. DOC was bound by AC, while the concentrations of nutrients (NO(3), NO(2), NH(4), PO(4), P-total, K, Ca and Mg) were variable and likely affected by external environmental factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Summary: special waste form lysimeters - arid program

    International Nuclear Information System (INIS)

    Skaggs, R.L.; Walter, M.B.

    1987-01-01

    The purpose of the Special Waste Form Lysimeters - Arid Program is to determine the performance of solidified commercial low-level waste forms using a field-scale lysimeter facility constructed for measuring the release and migration of radionuclides from the waste forms. The performance of these waste forms, as measured by radionuclide concentrations in lysimeter effluent, will be compared to that predicted by laboratory characterization of the waste forms. Waste forms being tested include nuclear power reactor waste streams that have been solidified in cement, Dow polymer, and bitumen. To conduct the field leaching experiments a lysimeter facility was built to measure leachate under actual environmental conditions. Field-scale samples of waste were buried in lysimeters equipped to measure water balance components, effluent radionuclide concentrations, and to a limited extent, radionuclide concentrations in lysimeter soil samples. The waste forms are being characterized by standard laboratory leach tests to obtain estimates of radionuclide release. These estimates will be compared to leach rates observed in the field. Adsorption studies are being conducted to determine the amount of contaminant available for transport after the release. Theoretical solubility calculations will also be performed to investigate whether common solid phases could be controlling radionuclide release. 4 references, 8 figures, 1 table

  15. Field lysimeter investigations: Low-level waste data base development program for fiscal year 1995. Volume 8, Annual report, October 1994-- September 1995

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.; Larsen, I.L.; Jastrow, J.D.; Sanford, W.E.; Sullivan, T.M.

    1996-06-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program, funded by the U.S. Nuclear Regulatory Commission, is (a) studying the degradation effects in organic ion-exchange resins caused by radiation, (b) examining the adequacy of test procedures recommended in the Branch Technical Position on Waste Form to meet the requirements of 10 CFR 61 using solidified ion-exchange resins, (c) obtaining performance information on solidified ion- exchange resins in a disposal environment, and (d) determining the condition of liners used to dispose the ion-exchange resins. Compressive test results of 12-year-old cement and vinyl ester- styrene solidified waste form samples are presented, which show effects of aging and self-irradiation. Results of the tenth year of data acquisition from the field testing are presented and discussed. During the continuing field testing, both portland type I-II cement and Dow vinyl ester-styrene waste form samples are being tested in lysimeter arrays located at Argonne National Laboratory-East in Illinois and at Oak Ridge National Laboratory. The study is designed to provide continuous data on nuclide release and movement, as well as environmental conditions, over a 20-year period

  16. Field Lysimeter Investigations - test results: Low-Level Waste Data Base Development Program: Test results for fiscal years 1994-1995

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rodgers, R.D.; Hilton, L.D.; Neilson, R.M. Jr.

    1996-06-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program, funded by the U.S. Nuclear Regulatory Commission (NRC), is (1) studying the degradation effects in EPICOR-II organic ion-exchange resins caused by radiation, (2) examining the adequacy of test procedures recommended in the Branch Technical Position on Waste Form to meet the requirements of 10 CFR 61 using solidified EPICOR-II resins, (3) obtaining performance information on solidified EPICOR-II ion-exchange resins in a disposal environment, and (4) determining the condition of EPICOR-II liners. Results of the final 2 (10 total) years of data acquisition from operation of the field testing are presented and discussed. During the continuing field testing, both portland type I-II cement and Dow vinyl ester-styrene waste forms are being tested in lysimeter arrays located at Argonne National Laboratory-East in Illinois and at Oak Ridge National Laboratory. The experimental equipment is described and results of waste form characterization using tests recommended by the NRC's open-quotes Technical Position on Waste Formclose quotes are presented. The study is designed to provide continuous data on nuclide release and movement, as well as environmental conditions, over a 20-year period. At the end of the tenth year, the experiment was closed down. Examination of soil and waste forms is planned to be conducted next and will be reported later

  17. Special waste-form lysimeters: Arid

    International Nuclear Information System (INIS)

    Jones, T.L.; Serne, R.J.

    1987-08-01

    The release of contaminant from solidified low-level waste forms is being studied in a field lysimeter facility at the Hanford Site in southeastern Washington State. Duplicate samples of five different waste forms have been buried in 10 lysimeters since March 1984. Waste-form samples represent three different waste streams and four solidification agents (masonry cement, Portland III cement, Dow polymer /sup (a)/, and bitumen). Most precipitation at the Hanford Site arrives as winter snow; this contributes to a strong seasonal pattern in water storage and drainage observed in the lysimeters. The result is an annual range in the volumetric soil water content from 11% in late winter to 7% in the late summer and early fall, as well as annual changes in pore water velocities from approximately 1 cm/wk in early spring to less than 0.05 cm/wk in early fall. Measurable quantities of tritium and cobalt-60 are being collected in lysimeter drainage water. Approximately 30% of the original tritium inventory has been leached from two lysimeters originally containing tritium. Cobalt-60 is present in all waste forms; it is being collected in the leachate from five lysimeters. The total amount released varies, but in each case it is less than 0.1% of the original cobalt inventory of the waste sample. Nonradioactive constituents contained in the waste form, such as sodium, boron, and sulfate, are also being leached

  18. Influence of hydrologic factors on leaching of solidified low-level waste forms at an arid site field-scale lysimeter facility

    International Nuclear Information System (INIS)

    Jones, T.L.; Skaggs, R.L.

    1987-04-01

    Most of the precipitation at the Hanford Site arrives as winter snow; this contributes to a strong seasonal pattern in water storage and drainage observed in the lysimeters. This seasonal pattern in storage corresponds to an annual range in the volumetric soil water content of 11% in late winter to 7% in the late summer and early fall. Annual changes in drainage rates cause pore water velocities to vary annually by nearly two orders of magnitude. Rapid snowmelt and frozen soils in February 1985 caused runoff water from areas adjacent to the lysimeter facility to flood three of the lysimeters. This resulted in a temporary increase in soil water storage, and an additional 5 to 10 cm of drainage for these three lysimeters. Measurable quantities of tritium and cobalt-60 are being collected in lysimeter drainage water. Approximately 30% of the original tritium inventory has been leached from both lysimeters containing samples of this waste form. Cobalt-60 is consistently being leached from five lysimeters representing three of the five waste forms. Total cobalt-60 collected from each of the five lysimeters varies, but in each case is less than 0.1% of the original cobalt inventory of the waste sample. Comparisons of cobalt release among flooded and non-flooded lysimeters show no significant difference caused by the extra drainage

  19. Lysimeter literature review

    International Nuclear Information System (INIS)

    Rogers, R.D.; McConnell, J.W. Jr.

    1993-08-01

    Many reports have been published concerning the use of lysimeters to obtain data on the performance of buried radioactive waste. This document presents a review of some of those reports. This review includes lysimeter studies using radioactive waste forms at Savannah River Site, Hanford Site, Argonne National Laboratory, and Oak Ridge National Laboratory; radionuclide tracer studies at Whiteshell Nuclear Research Establishment and Los Alamos National Laboratory; and water movement studies at the Nuclear Regulatory Commission's Beltsville, Maryland site, at the Hanford Site, and at New Mexico State University. The tests, results, and conclusions of each report are summarized, and conclusions concerning lysimeter technology are presented from an overall analysis of the literature. 38 refs., 44 figs., 9 tabs

  20. Managing Salmonella Typhimurium and Escherichia coli O157:H7 in soil with hydrated lime - An outdoor study in lysimeters and field plots.

    Science.gov (United States)

    Nyberg, Karin A; Vinnerås, Björn; Albihn, Ann

    2014-01-01

    An outbreak of Salmonella Typhimurium or E. coli O157:H7 among domestic animals can have great financial consequences for an animal enterprise but also be a threat for public health as there is a risk for transmission of the infection through the environment. In order to minimize disease transmission, it is important to treat not only the affected animals but also the areas on which they have been kept. In the present study, the effect of hydrated lime as a treatment for Salmonella Typhimurium or E. coli O157:H7 contaminated soil was investigated. The study was performed outdoors, in a lysimeter system and in field plots. The soils were spiked with Salmonella Typhimurium and/or E. coli O157:H7 and hydrated lime was added at three different concentrations (0.5, 1 and 2%). Sampling was performed over one month, and the levels of bacteria were analyzed by standard culture methods. In addition, the soil pH was monitored throughout the study. The results showed that application of 0.5-1 kg hydrated lime per m(2) reduced both Salmonella Typhimurium and E. coli O157:H7 numbers to below the detection limit (2 log10 CFU g-1 soil) in 3-7 days. Lower application rates of hydrated lime did not reduce pathogen numbers in the lysimeter study, but in the field plots no E. coli O157:H7 was detected at the end of the four-week study period regardless of hydrated lime application. A recommended strategy for treating a Salmonella Typhimurium or E. coli O157:H7 contaminated soil could therefore be to monitor the pH over the time of treatment and to repeat hydrated lime application if a decrease in pH is observed.

  1. Comparison of different soil water extraction systems for the prognoses of solute transport at the field scale using numerical simulations, field and lysimeter experiments

    Energy Technology Data Exchange (ETDEWEB)

    Weihermueller, L

    2005-07-01

    To date, the understanding of processes, factors, and interactions that influence the amount of extracted water and the solute composition sampled with suction cups is limited. But this information is required for process description of solute transport in natural soils. Improved system understanding can lead to a low cost and easy to install water sampling system which can help to predict solute transport in natural soils for the benefit of environmental protection. The main objectives of this work were to perform numerical simulations with different boundary conditions and to implement the findings in the interpretation of the lysimeter and field experiments. In a first part of this thesis, theoretical considerations on the processes affecting the spatial influence of a suction cup in soil and changes in solute transport initiated by the suction cups are presented, including testing and validation of available model and experimental approaches. In the second part, a detailed experimental study was conducted to obtain data for the comparison of the different soil water sampling systems. Finally, the numerical experiments of the suction cup influence were used for the interpretation of the experimental data. The main goals are summarized as follows: - Characterization of the suction cup activity domain (SCAD), suction cup extraction domain (SCED) and suction cup sampling area (SCSA) of active suction cups (definitions are given in Chapter 6). - Determination of the boundary conditions and soil properties [e.g. infiltration, applied suction, duration of water extraction, soil hydraulic properties and soil heterogeneity] affecting the activity domain, extraction domain and sampling area of a suction cup. - Identification of processes that change the travel time and travel time variance of solutes extracted by suction cups. - Validation of the numerically derived data with analytical and experimental data from literature. - Comparison of the experimental data obtained

  2. Persistence of 14C-labeled atrazine and its residues in a field lysimeter soil after 22 years

    International Nuclear Information System (INIS)

    Jablonowski, Nicolai D.; Koeppchen, Stephan; Hofmann, Diana; Schaeffer, Andreas; Burauel, Peter

    2009-01-01

    Twenty-two years after the last application of ring- 14 C-labeled atrazine at customary rate (1.7 kg ha -1 ) on an agriculturally used outdoor lysimeter, atrazine is still detectable by means of accelerated solvent extraction and LC-MS/MS analysis. Extractions of the 0-10 cm soil layer yielded 60% of the residual 14 C-activity. The extracts contained atrazine (1.0 μg kg -1 ) and 2-hydroxy-atrazine (42.5 μg kg -1 ). Extractions of the material of the lowest layer 55-60 cm consisting of fine gravel yielded 93% of residual 14 C-activity, of which 3.4 μg kg -1 was detected as atrazine and 17.7 μg kg -1 was 2-hydroxy-atrazine. The detection of atrazine in the lowest layer was of almost four times higher mass than in the upper soil layer. These findings highlight the fact that atrazine is unexpectedly persistent in soil. The overall persistence of atrazine in the environment might represent a potential risk for successive groundwater contamination by leaching even after 22 years of environmental exposure. - Atrazine and its metabolite 2-hydroxy-atrazine are still present in soil after long-term aging.

  3. Measurement of precipitation using lysimeters

    Science.gov (United States)

    Fank, Johann; Klammler, Gernot

    2013-04-01

    Austria's alpine foothill aquifers contain important drinking water resources, but are also used intensively for agricultural production. These groundwater bodies are generally recharged by infiltrating precipitation. A sustainable water resources management of these aquifers requires quantifying real evapotranspiration (ET), groundwater recharge (GR), precipitation (P) and soil water storage change (ΔS). While GR and ΔS can be directly measured by weighable lysimeters and P by separate precipitation gauges, ET is determined by solving the climatic water balance ET = P GR ± ΔS. According to WMO (2008) measurement of rainfall is strongly influenced by precipitation gauge errors. Most significant errors result from wind loss, wetting loss, evaporation loss, and due to in- and out-splashing of water. Measuring errors can be reduced by a larger area of the measuring gaugés surface and positioning the collecting vessel at ground level. Modern weighable lysimeters commonly have a surface of 1 m², are integrated into their typical surroundings of vegetation cover (to avoid oasis effects) and allow scaling the mass change of monolithic soil columns in high measuring accuracy (0.01 mm water equivalent) and high temporal resolution. Thus, also precipitation can be quantified by measuring the positive mass changes of the lysimeter. According to Meissner et al. (2007) also dew, fog and rime can be determined by means of highly precise weighable lysimeters. Furthermore, measuring precipitation using lysimeters avoid common measuring errors (WMO 2008) at point scale. Though, this method implicates external effects (background noise, influence of vegetation and wind) which affect the mass time series. While the background noise of the weighing is rather well known and can be filtered out of the mass time series, the influence of wind, which blows through the vegetation and affects measured lysimeter mass, cannot be corrected easily since there is no clear relation between

  4. Evaluation and performance of the special wasteform lysimeters at a humid site

    International Nuclear Information System (INIS)

    Oblath, S.B.; Hoeffner, S.L.

    1985-09-01

    The Savannah River Laboratory has been evaluating the leaching/migration behavior of commercial power reactor wasteforms by the use of lysimeters operated under field conditions at a humid site. These lysimeters model the conditions in actual burial trenches. Wasteforms comprising Portland cement, masonry cement, and vinyl ester-styrene polymer wasteforms were emplaced in the lysimeters in March 1982. Effluent water has been analyzed on a regular basis since that time. Cs-137, Sr-90, and/or Co-60 have observed in the effluent water from the lysimeters, as well as in soil moisture samples collected from the unsaturated zone beneath the wasteforms. In March of 1984, horizontal cores were taken from one of the lysimeters containing a Portland cement wasteform to determine the vertical and radial profiles of radionuclides which might not have reached the lysimeter sump. Results from all of these sampling methods are discussed and interpreted. 6 refs., 3 figs., 3 tabs

  5. Experiences with the use of conservative tracers as an aid in transferring lysimeter results to the open field; Erfahrungen beim Einsatz von konservativen Tracern als Hilfsmittel zur Uebertragung von Lysimeterergebnissen auf Freilandflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, J.; Meissner, R.; Rupp, H. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Falkenberg (Germany). Lysimeterstation; Mueller, L.; Eulenstein, F. [Zentrum fuer Agrarlandschafts- und Landnutzungsforschung e.V. (ZALF), Muencheberg (Germany)

    1999-02-01

    Four lysimeter trials performed on an IS-type soil yielded an almost constant range of displacement of a tracer front (NO{sub 3} front) of 4.0 to 4.5 mm / l of seepage water (referred to a surface area of 1 m-2 and a depth of 1 m). This was experimental confirmation of a tentatively formulated simplified relationship between seepage water volume, vertical tracer displacement, and field capacity. The results were also in very good agreement with those of a control study in the open field carried out under similar hydrological, pedological, and agrotechnical conditions using lysimeters and Cl tracers for determining quantities of seepage water formation. As the present lysimeter trials mirror soil hydrological processes in the open field with sufficient accuracy, they appear well suited to take the place of the so often lacking territorial data as a means of validating mathematical models describing seepage-water-bound material export. [Deutsch] Auf der Basis von 4 Lysimeterversuchen konnte fuer die Bodenart IS ein nahezu konstanter Wertebereich fuer die Verlagerung einer Tracerfront (NO{sub 3}-Front) in Hoehe von 4,0 bis 4,5 mm/l Sickerwasser (bezogen auf eine Oberflaeche von 1 m{sup 2} und eine Tiefe von 1 m) ermittelt werden. Damit konnte die vereinfachte Beziehung zwischen Sickerwassermenge, Tracerverlagerungstiefe und Feldkapazitaet experimentell bestaetigt werden. Ein Vergleich zur Bestimmung der Sickerwassermengenbildung mit Hilfe von Lysimetern und durch Einsatz von Cl-Tracern unter aehnlich hydrologischen, pedologischen und agrotechnischen Bedingungen im Freiland wies eine hohe Uebereinstimmung auf. Da die hier durchgefuehrten Lysimeteruntersuchungen bodenhydrologische Prozesse von Freilandflaechen mit ausreichender Genauigkeit widerspieglen, erscheinen sie anstelle oft fehlender Gebietskenndaten zur Validierung von mathematischen Modellen zur Beschreibung sickerwassergebundener Stoffaustraege gut geeignet. (orig.)

  6. The estimation of soil water fluxes using lysimeter data

    Science.gov (United States)

    Wegehenkel, M.

    2009-04-01

    The validation of soil water balance models regarding soil water fluxes in the field is still a problem. This requires time series of measured model outputs. In our study, a soil water balance model was validated using lysimeter time series of measured model outputs. The soil water balance model used in our study was the Hydrus-1D-model. This model was tested by a comparison of simulated with measured daily rates of actual evapotranspiration, soil water storage, groundwater recharge and capillary rise. These rates were obtained from twelve weighable lysimeters with three different soils and two different lower boundary conditions for the time period from January 1, 1996 to December 31, 1998. In that period, grass vegetation was grown on all lysimeters. These lysimeters are located in Berlin, Germany. One potential source of error in lysimeter experiments is preferential flow caused by an artificial channeling of water due to the occurrence of air space between the soil monolith and the inside wall of the lysimeters. To analyse such sources of errors, Hydrus-1D was applied with different modelling procedures. The first procedure consists of a general uncalibrated appli-cation of Hydrus-1D. The second one includes a calibration of soil hydraulic parameters via inverse modelling of different percolation events with Hydrus-1D. In the third procedure, the model DUALP_1D was applied with the optimized hydraulic parameter set to test the hy-pothesis of the existence of preferential flow paths in the lysimeters. The results of the different modelling procedures indicated that, in addition to a precise determination of the soil water retention functions, vegetation parameters such as rooting depth should also be taken into account. Without such information, the rooting depth is a calibration parameter. However, in some cases, the uncalibrated application of both models also led to an acceptable fit between measured and simulated model outputs.

  7. Mathematical study of a lysimeter

    International Nuclear Information System (INIS)

    Gibson, D.K.

    1987-11-01

    In studies of the rehabilitation of mine overburden heaps at Rum Jungle in the Northern Territory of Australia, simple buried water collectors have been used as lysimeters to measure the infiltration into the heaps. This report describes the development and results of a study state finite difference computer code which calculates the movement of water in such systems. It is shown that the water collection efficiency of this type of lysimeter depends strongly on the hydraulic properties of the soil in which it is buried, as does the rate of capillary loss during periods of zero infiltration

  8. Lysimeter data as input to performance assessment models

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.

    1998-01-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-117 prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. The program includes reviewing radionuclide releases from those waste forms in the first 7 years of sampling and examining the relationship between code input parameters and lysimeter data. Also, lysimeter data are applied to performance assessment source term models, and initial results from use of data in two models are presented

  9. Large zero-tension plate lysimeters for soil water and solute collection in undisturbed soils

    Directory of Open Access Journals (Sweden)

    A. Peters

    2009-09-01

    Full Text Available Water collection from undisturbed unsaturated soils to estimate in situ water and solute fluxes in the field is a challenge, in particular if soils are heterogeneous. Large sampling devices are required if preferential flow paths are present. We present a modular plate system that allows installation of large zero-tension lysimeter plates under undisturbed soils in the field. To investigate the influence of the lysimeter on the water flow field in the soil, a numerical 2-D simulation study was conducted for homogeneous soils with uni- and bimodal pore-size distributions and stochastic Miller-Miller heterogeneity. The collection efficiency was found to be highly dependent on the hydraulic functions, infiltration rate, and lysimeter size, and was furthermore affected by the degree of heterogeneity. In homogeneous soils with high saturated conductivities the devices perform poorly and even large lysimeters (width 250 cm can be bypassed by the soil water. Heterogeneities of soil hydraulic properties result into a network of flow channels that enhance the sampling efficiency of the lysimeter plates. Solute breakthrough into zero-tension lysimeter occurs slightly retarded as compared to the free soil, but concentrations in the collected water are similar to the mean flux concentration in the undisturbed soil. To validate the results from the numerical study, a dual tracer study with seven lysimeters of 1.25×1.25 m area was conducted in the field. Three lysimeters were installed underneath a 1.2 m filling of contaminated silty sand, the others deeper in the undisturbed soil. The lysimeters directly underneath the filled soil material collected water with a collection efficiency of 45%. The deeper lysimeters did not collect any water. The arrival of the tracers showed that almost all collected water came from preferential flow paths.

  10. Leaching of transuranics observed in lysimeter experiments

    International Nuclear Information System (INIS)

    Erikson, A.; Fredriksson, L.

    1994-01-01

    A lysimeter installation, primarily designed for studies on plant uptake of transuranics from a number of Swedish soils, has been used also for studies on leaching of nuclides with drainage water from contaminated top soil layers in lysimeter vessels through 65 cm subsoil layers. Interception by ion exchanging resins simulated the nuclide transfer to a field drainage system. The study dealt with the contamination of agricultural land. The results obtained in the experiments have to be interpreted cautiously with regard to their bearing on field conditions. Also, the experimental period has been short when compared with the expected ecological half time of transuranic elements in the environment. However, the results indicate that over a first decade the leaching to drainage systems of transuranics in equilibrium with soil environments is of the same order as that of the crop uptake. The ranges assessed for leaching with an excess precipitation of 200 mm from a deposit in the plough layer to the drainage system during a decade are: for plutonium - 0.003-0.8%, for americium - 0.004-0.006% and for neptunium - 0.03-0.06%. The values for plutonium and americium are very similar except for the organic soil used which held the former nuclide very loosely bound. The leaching of neptunium seems to be ten times that for the other nuclides. It is higher on sandy soils than on organic and clay soils. (author)

  11. Integrating lysimeter drainage and eddy covariance flux measurements in a groundwater recharge model

    DEFF Research Database (Denmark)

    Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø

    2015-01-01

    Field scale water balance is difficult to characterize because controls exerted by soils and vegetation are mostly inferred from local scale measurements with relatively small support volumes. Eddy covariance flux and lysimeters have been used to infer and evaluate field scale water balances...... because they have larger footprint areas than local soil moisture measurements.. This study quantifies heterogeneity of soil deep drainage (D) in four 12.5 m2 repacked lysimeters, compares evapotranspiration from eddy covariance (ETEC) and mass balance residuals of lysimeters (ETwbLys), and models D...

  12. Special waste form lysimeters-arid. Annual report, 1985

    International Nuclear Information System (INIS)

    Walter, M.B.; Graham, M.J.

    1985-09-01

    The Special Waste Form Lysimeters-Arid program was initiated to determine typical source terms generated by commercial solidified low-level nuclear waste in an arid climate. Waste-form leaching tests are being conducted at a field facility at the Hanford site near Richland, Washington. A similar program is being conducted at a humid site. The field facility consists of 10 lysimeters placed around a central instrument caisson. The waste samples from boiling water and pressurized water reactors were emplaced in 1984, and the lysimeters are being monitored for movement of contaminants and water. Solidifying agents being tested include vinyl ester-styrene, bitumen, and cement. Laboratory leaching and geochemical modeling studies are being conducted to predict expected leach rates at the field site and to aid field-data interpretation. Small samples of the solidified waste forms were made for use in the laboratory leaching studies that include standard leach tests and leaching of solidified waste forms in soil columns. Complete chemical and radionuclide analyses are being conducted on the solid and liquid portions of the wastes. 2 refs

  13. Special Waste Form Lysimeters-Arid: annual report 1985

    International Nuclear Information System (INIS)

    Walter, M.B.; Graham, M.J.

    1986-01-01

    The Special Waste Form Lysimeters-Arid program was initiated to determine typical source terms generated by commercial solidified low-level nuclear waste in an arid climate. Waste-form leaching tests are being conducted at a field facility at the Hanford site near Richland, Washington. A similar program is being conducted at a humid site. The field facility consists of 10 lysimeters placed around a central instrument caisson. The waste samples from boiling water and pressurized water reactors were emplaced in 1984, and the lysimeters are being monitored for movement of contaminants and water. Solidifying agents being tested include vinyl ester-styrene, bitumen, and cement. Laboratory leaching and geochemical modeling studies are being conducted to predict expected leach rates at the field site and to aid field-data interpretation. Small samples of the solidified waste forms were made for use in the laboratory leaching studies that include standard leach tests and leaching of solidified waste forms in soil columns. Complete chemical and radionuclide analyses are being conducted on the solid and liquid portions of the wastes

  14. Lysimeter study of vegetative uptake from saltstone

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.E. Jr.

    1990-06-08

    At the Savannah River Site, liquid, low-level nuclear waste will be disposed of by incorporating the waste in concrete, a wasteform called saltstone. Saltstone monoliths will then be buried in the earth. To study the potential uptake of radionuclides by trees and other plants growing in the soil in the area containing buried saltstone, a lysimeter study has been in progress since 1984. Thirty two lysimeters were designed, constructed, and filled with soil. Saltstone samples, containing the liquid, low-level supernate from the tank 50 in-tank precipitation demonstration, were buried in some of the lysimeters. Other lysimeters, not containing saltstone, were used as controls. Crops, grass, and trees were planted in the lysimeters and sampled periodically to determine radionuclide concentrations. Water samples were also collected from the lysimeter sumps and analyzed for radionuclide content. This report documents the results of vegetative and lysimeter sump water measurements from the beginning of the project in November of 1984 through September of 1989. 6 refs., 22 figs., 6 tabs.

  15. Contributions of lysimeter data to the development of site specific performance assessment plans

    International Nuclear Information System (INIS)

    Rogers, R.D.; McConnell, J.W. Jr.; Jastrow, J.D.; Wickliff, D.S.

    1991-01-01

    Accurate data on the long-term performance of radioactive wastes in a disposal system are becoming a necessity in part because of restrictive federal and state regulations that are being promulgated. Data on the performance of buried radioactive waste forms can be obtained from lysimeter arrays. Lysimeters are ideal instruments for the acquisition of actual field test data. When properly designed and operated, lysimeters can be used to isolate and then study soil/waste systems under actual environmental conditions. The complexity of interactions occurring under field conditions can never by completely duplicated by standard laboratory testing. This paper provides data from two instrumented, operational lysimeter arrays containing waste forms fabricated with highly located exchange resin materials. The lysimeters have been in operation for five years and have been providing data for both meteorological events and radionuclide content of percolating water for the past four years. This paper provides data obtained from the lysimeters, a discussion of the data, and a manipulation of the database for calculating some code parameters that can be used as input into codes used to verify performance of buried radioactive waste forms

  16. Monitoring the performance of an alternative cover using caisson lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J.; Smith, G.M.; Mushovic, P.S.

    2004-02-29

    The U.S. Department of Energy (DOE) office in Grand Junction, Colorado, and the U.S. Environmental Protection Agency (EPA), Region 8, collaborated on a series of field lysimeter studies to design and monitor the performance of an alternative cover for a uranium mill tailings disposal cell at the Monticello, Utah, Superfund Site. Because groundwater recharge is naturally limited at Monticello in areas with thick loess soils, DOE and EPA chose to design a cover for Monticello using local soils and a native plant community to mimic this natural soilwater balance. Two large drainage lysimeters fabricated of corrugated steel culvert lined with high-density polyethylene were installed to evaluate the hydrological and ecological performance of an alternative cover design constructed in 2000 on the disposal cell. Unlike conventional, lowpermeability designs, this cover relies on (1) the water storage capacity of a 163-cm soil “sponge” layer overlying a sand-and-gravel capillary barrier to retain precipitation while plants are dormant and (2) native vegetation to remove precipitation during the growing season. The sponge layer consists of a clay loam subsoil compacted to 1.65 g/cm2 in one lysimeter and a loam topsoil compacted to 1.45 g/cm2 in the other lysimeter, representing the range of as-built conditions constructed in the nearby disposal cell cover. About 0.1 mm of drainage occurred in both lysimeters during an average precipitation year and before they were planted, an amount well below the EPA target of <3.0 mm/yr. However, the cover with less compacted loam topsoil sponge had a 40% greater water storage capacity than the cover with overly compacted clay loam subsoil sponge. The difference is attributable in part to higher green leaf area and water extraction by plants in the loam topsoil. The lesson learned is that seemingly subtle differences in soil types, sources, and compaction can result in salient differences in performance. Diverse, seeded communities of

  17. Lysimeter data as input to performance assessment source term codes

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Rogers, R.D.; Sullivan, T.

    1992-01-01

    The Field Lysimeter Investigation: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-II c prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. In this paper, radionuclide releases from waste forms in the first seven years of sampling are presented and discussed. Application of lysimeter data to be used in performance assessment source term models is presented. Initial results from use of data in two models are discussed

  18. Water transport monitoring in an unsaturated zone – Case study: lysimeter Selniška dobrava (Slovenia

    Directory of Open Access Journals (Sweden)

    Nina Mali

    2002-12-01

    Full Text Available Pollution transport in an aquifer depends on its structure, upper unsaturated zone and lower saturated zone. In order to understand processes in the unsaturated zone, several hydrogeological field measurements must be done. A field laboratory- lysimeter in Selni{kadobrava was installed for the improvement of field measurements, and explanation of the parameters and processes in the unsaturated zone. The problems, which can be solved by means of investigations in a lysimeter, are defined in this paper. Described are also:concept of investigation planning, construction and equipment of the lysimeter, measurements of unsaturated zone parameters and processes, water sampling for physical, chemical and isotope analysis.

  19. Investigations of pollutant migration using lysimeters

    International Nuclear Information System (INIS)

    Klotz, D.

    2002-01-01

    The third GSF Lysimeter Workshop focused on pollutant migration in underground strata, i.e. the dispersion of water constituents as referred to water transport on the basis of ideal tracer investigations [de

  20. Use of Long-Term Lysimeter Data in Support of Shallow Land Waste Disposal Cover Design

    International Nuclear Information System (INIS)

    Desotell, L.T.; Hudson, D.B.; Yucel, V.; Carilli, J.T.

    2006-01-01

    Water balance studies using two precision weighing lysimeters have been conducted at the Nevada Test Site in support of low-level radioactive waste disposal since 1994. The lysimeters are located in northern Frenchman Flat approximately 400 meters (m) from the southwest corner of the Area 5 Radioactive Waste Management Site. Frenchman Flat is in the northern Mojave Desert and has an average annual precipitation of 125 millimeters (mm). Each lysimeter consists of a 2 m by 4 m by 2 m deep steel tank filled with native alluvium, supported on a sensitive scale. The scale is instrumented with an electronic load-cell and data-logger for continuous measurement of total soil water storage with a precision of approximately ±800 grams or ±0.1 mm of soil water storage. Data-loggers are linked to cell phone modems for remote data acquisition. One lysimeter is vegetated with native creosote bush, four wing salt bush, and annual grass at the approximate density of the surrounding landscape while the other is maintained as bare soil. Since no drainage has been observed from the bottom of the lysimeters and run-on/run-off is precluded, the change in soil-water storage is equal to precipitation minus evaporation/evapotranspiration. After equilibration, the bare lysimeter contains approximately 20.2 centimeters (cm) of water (10.1 % volumetric water content) and the vegetated lysimeter contains approximately 11.6 cm of water (5.8 % volumetric water content). The finite difference code UNSAT-H was used to simulate the continuous water balance of the lysimeters. Calibrated one-dimensional model simulations were generally in agreement with field data. 30-year model simulations were conducted to evaluate long-term potential transport of radionuclides via the soil water migration pathway. A 30-year climate record was generated by repeating the existing data record. Simulations indicate a 2 m thick closure cover, in conjunction with native vegetation, will essentially eliminate drainage

  1. Determining water and nitrogen balances for beneficial management practices using lysimeters at Wagna test site (Austria).

    Science.gov (United States)

    Klammler, Gernot; Fank, Johann

    2014-11-15

    The shallow Murtal aquifer south of Graz, Austria, provides easily withdrawable groundwater, which is supplied as drinking water without any chemical treatment. The aquifer is also used intensively by agriculture. Common agricultural management practices are the main source for diffuse nitrogen leaching and high groundwater nitrate concentrations. To safeguard the coexisting use of these two important resources, lysimeters are operated at the agricultural test site Wagna, Austria, and the influence of two beneficial management practices--low nitrogen input and organic farming--on nitrogen leaching towards groundwater is investigated. The technical lysimeter design as presented here consists of: (1) high-resolution weighing cells, (2) a suction controlled lower boundary condition for sucking off seepage water, thus emulating undisturbed field conditions, (3) comparative soil temperature, water content and matrix potential measurements inside and outside the lysimeter at different depths, (4) an installation of the lysimeters directly into test plots and (5) a removable upper lysimeter ring enabling machinery soil tillage. Our results indicate that oasis effects or fringe effects of the lysimeter cylinder on unsaturated water flow did not occur. Another lysimeter cultivated with lawn is operated for observing grass-reference evapotranspiration, which resulted in good agreement with calculated grass-reference evapotranspiration according to the FAO-Penman-Monteith method. We conclude that lysimeters installed at Wagna test site did not show any fringe effects and, thus, are appropriate tools for measuring water balance elements and nitrogen leaching of arable and grass land at point scale. Furthermore, our results for the period of 2005 to 2011 show that beneficial management practices reduced nitrate leaching and, hence, may allow for a sustainable coexistence of drinking water supply and agriculture in the Murtal aquifer. Copyright © 2014 Elsevier B.V. All rights

  2. Geochemical Modeling of ILAW Lysimeter Water Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-22

    Geochemical modeling results of water extracts from simulated immobilized low-activity waste (ILAW) glasses, placed in lysimeters for eight years suggest that the secondary phase reaction network developed using product consistency test (PCT) results at 90°C may need to be modified for field conditions. For sediment samples that had been collected from near the glass samples, the impact of glass corrosion could be readily observed based upon the pH of their water extracts. For unimpacted sediments the pH ranged from 7.88 to 8.11 with an average of 8.04. Sediments that had observable impacts from glass corrosion exhibited elevated pH values (as high as 9.97). For lysimeter sediment samples that appear to have been impacted by glass corrosion to the greatest extent, saturation indices determined for analcime, calcite, and chalcedony in the 1:1 water extracts were near equilibrium and were consistent with the secondary phase reaction network developed using PCT results at 90°C. Fe(OH)3(s) also appears to be essentially at equilibrium in extracts impacted by glass corrosion, but with a solubility product (log Ksp) that is approximately 2.13 units lower than that used in the secondary phase reaction network developed using PCT results at 90°C. The solubilities of TiO2(am) and ZrO2(am) also appear to be much lower than that assumed in the secondary phase reaction network developed using PCT results at 90°C. The extent that the solubility of TiO2(am) and ZrO2(am) were reduced relative to that assumed in the secondary phase reaction network developed using PCT results at 90°C could not be quantified because the concentrations of Ti and Zr in the extracts were below the estimated quantification limit. Gibbsite was consistently highly oversaturated in the extract while dawsonite was at or near equilibrium. This suggests that dawsonite might be a more suitable phase for the secondary phase reaction network

  3. Leaching of pesticides through normal-tillage and low-tillage soil--a lysimeter study. I. Isoproturon.

    Science.gov (United States)

    Fomsgaard, Inge S; Spliid, Niels Henrik; Felding, Gitte

    2003-01-01

    Isoproturon is a herbicide, which was used in Denmark against grass weeds and broad-leaved weeds until 1998. Isoproturon has frequently been detected in ground water monitoring studies. Leaching of isoproturon (N,N-dimethyl-N'-(4-(1-methylethyl)-phenyl)urea) and its metabolites, N'-(4-isopropylphenyl)-N-methylurea and N'-(4-isopropylphenyl)urea was studied in four lysimetres, two of them being replicates from a low-tillage field (lysimeter 3 and 4), the other two being replicates from a normal tillage field (lysimeter 5 and 6). In both cases the soil was a sandy loam soil with 13-14% clay. The lysimetres had a surface area of 0.5 m2 and a depth of 110 cm. Lysimeter 3 and 4 were sprayed with unlabelled isoproturon while lysimeter 5 and 6 was sprayed with a mixture of 14C-labelled and unlabelled isoproturon. The total amount of isoproturon sprayed onto each lysimeter was 63 mg, corresponding to 1.25 kg active ingredient per ha. The lysimeters were sprayed with isoproturon on October 26, 1997. The lysimetres were installed in an outdoor system in Research Centre Flakkebjerg and were thus exposed to normal climatic conditions of the area. A mean of 360 l drainage water were collected from lysimeter 3 and 4 and a mean of 375 litres from lysimeter 5 and 6. Only negligible amounts of isoproturon and its primary metabolites were found in the drainage water samples, and thus no significant difference between the two lysimeter sets was shown. In a total of 82 drainage water samples, evenly distributed between the four lysimetres isoproturon was found in detectable amounts in two samples and N'-(4-isopropylphenyl)urea was found in detectable amounts in two other samples. The detection limit for all the compounds was 0.02 microg/l. 48% and 54% of the added radioactivity were recovered from the upper 10 cm soil layer in lysimeter 5 and 6, respectively, and 17 and 14% from 10-20 cm's depth. By extraction first with an aquatic CaCl2 solution 0.49% of the added radioactivity was

  4. Engineered surface barriers for waste disposal sites: lysimeter facility design and construction

    International Nuclear Information System (INIS)

    Phillips, S.J.; Ruben, M.S.; Kirkham, R.R.

    1988-01-01

    A facility to evaluate performance of engineered surface carriers for confinement of buried wastes has been designed, constructed, and operations initiated. The Field Lysimeter Test Facility is located at the US Department of Energy's Hanford Site in Richland, Washington. The facility consists of 18 one-dimensional drainage and weighing lysimeters used to evaluate 7 replicated barrier treatments. Distinct layers of natural earth materials were used to construct layered soil and rock barriers in each lysimeter. These barrier designs are capable in principal of significantly reducing or precluding infiltration of meteoric water through barriers into underlying contaminated zones. This paper summarizes salient facility design and construction features used in testing of the Hanford Site's engineered surface barriers

  5. Mathematisches Bewusstsein

    Science.gov (United States)

    Kaenders, Rainer; Kvasz, Ladislav

    Wenn jemand sagt, dass ein Bus um 9 Uhr abfährt - weiß man es dann? Angenommen, man ist darüber unterrichtet, dass die Busse unter der Woche immer zur vollen Stunde abfahren - von 7 Uhr morgens bis 7 Uhr abends, weiß man es dann mit dem Wissen um diese allgemeine Regel besser, dass der Bus um 9 Uhr abfährt? Macht es einen Unterschied, ob man den Fahrplan erstellt, den Bus lenkt oder nur mitfährt, um sich dieser Tatsache bewusst zu sein?

  6. Comparative investigations on the transferability of results from standardized vessel and lysimeter experiments on the actual field conditions with the example of the residue situation in plants after spraying with Goltix and Tribunil

    International Nuclear Information System (INIS)

    Hansper, M.

    1986-06-01

    The radioactivity values in the plant samples of the lysimeter and vessel experiments made it possible to calculate the material equivalent quantities in mg/kg of fresh or dry mass. The basis for the calculation was the specific 14 C activity of the applied materials. In these calculated material equivalent quantities one is dealing with compounds, which originate from a large number of material change processes including reassimilated in 14 CO 2 from decomposition processes in the ground. Within one test unit, with one exception, double quantities always led to residues of more than twice as much in the plants. (orig./PW) [de

  7. Leaching of transuranics observed in lysimeter experiments

    International Nuclear Information System (INIS)

    Eriksson, A.; Fredriksson, L.

    1994-01-01

    Transuranic elements in fallout are generally bound in oxide particles, size from submicron to several microns. During the fallout they can be intercepted on plant covers or reach the soil surface. The particles can be re-suspended to the air and reach other residence sites, be linked into the food chain or be redistributed in other ways (Cf Essington et al. 1976) before eventually being incorporated into the soil. The fate of such particles in the soil depends on the size and on the nature of the particulate matter and on environmental factors, the climate and the properties of the soil. In a dry climate the particles tend to be kept intact long time, (Schulz et al. 1976) and they are more easily redistributed than in a humid climate with plant covered moist and living soils. In the former the particles move more easily in the soil profile than in the latter, the particle matter is very slowly dissolved and the average availability of the deposited nuclides for plant uptake can be assumed to be comparatively low. The downward movements of the particles or nuclide compounds bound to small soil particles are enhanced by the swelling and shrinking of soil caused by absorption and depletion of water during the season. Cracks and fissures are created and closed several times a year in soils rich in colloidal material. Sandy soils with coarse material have less cracks, but in dry conditions the empty pore space may allow transport of fine particles. The coarser material also has less specific area and sorption capacity. The nuclide compounds leached with the drainage water in coarse soils should be less retarded than in clays (Cf. Rai and Serne, 1977; Nishita and Haug, 1979 and Rai et al., 1980). The lysimeter installation used for the study reported below was primarily designed to study the plant uptake of transuranics from a number of Swedish soils. However, as such an installation in many ways well simulate field conditions and at the same time is a closed system

  8. De AERA. Gedroomde machines en de praktijk van het rekenwerk aan het Mathematisch Centrum te Amsterdam

    Directory of Open Access Journals (Sweden)

    Gerard Alberts

    2008-06-01

    Full Text Available AERA. Dream machines and computing practices at the Mathematical Center  Dream machines may be just as effective as the ones materialised. Their symbolic thrust can be quite powerful. The Amsterdam ‘Mathematisch Centrum’ (Mathematical Center, founded February 11, 1946, created a Computing Department in an effort to realise its goal of serving society. When Aad van Wijngaarden was appointed as head of the Computing Department, however, he claimed space for scientific research and computer construction, next to computing as a service. Still, the computing service following the five stage style of Hartree’s numerical analysis remained a dominant chara c ter istic of the work of the Computing Department.The high level of ambition held by Aad van Wijngaarden lead to ever renewed projections of big automatic computers, symbolised by the never-built AERA. Even a machine that was actually constructed, the ARRA which followed A.D. Booth’s design of the ARC, never made it into real operation. It did serve Van Wijngaarden to bluff his way into the computer age by midsummer 1952. Not until January 1954 did the computing department have a working stored program computer, which for reasons of policy went under the same name: ARRA. After just one other machine, the ARMAC, had been produced, a separate company, Electrologica, was set up for the manufacture of computers, which produced the rather successful X1 computer.The combination of ambition and absence of a working machine lead to a high level of work on programming, way beyond the usual ideas of libraries of subroutines. Edsger W. Dijkstra in particular led the way to an emphasis on the duties of the programmer within the pattern of numerical analysis. Programs generating programs, known elsewhere as autocoding systems, were at the ‘Mathematisch Centrum’ called ‘superprograms’. Practical examples were usually called a ‘complex’, in Dutch, where in English one might say

  9. Special waste-form lysimeters-arid: Three-year monitoring report

    International Nuclear Information System (INIS)

    Jones, T.L.; Serne, R.J.; Toste, A.P.

    1988-04-01

    Regulations governing the disposal of commercial low-level waste require all liquid waste to be solidified before burial. Most waste must be solidified into a rigid matrix such as cement or plastic to prevent waste consolidation and site slumping after burial. These solidification processes affect the rate at which radionuclides and other solutes are released into the soil. In 1983, a program was initiated at Pacific Northwest Laboratory to study the release of waste from samples of low-level radioactive waste that had been commercially solidified. The primary method used by this program is to bury sample waste forms in field lysimeters and monitor leachate composition from the release and transport of solutes. The lysimeter facility consists of 10 lysimeters, each containing one sample of solidified waste. Five different waste forms are being tested, allowing duplicate samples of each one to be evaluated. The samples were obtained from operating nuclear power plants and are actual waste forms routinely generated at these facilities. All solidification was accomplished by commercial processes. Sample size is a partially filled 210-L drum. All containers were removed prior to burial leaving the bare waste form in contact with the lysimeter soil. 11 refs., 14 figs., 16 tabs

  10. Effects of biochar addition to soil on nitrogen fluxes in a winter wheat lysimeter experiment

    Science.gov (United States)

    Hüppi, Roman; Leifeld, Jens; Neftel, Albrecht; Conen, Franz; Six, Johan

    2014-05-01

    Biochar is a carbon-rich, porous residue from pyrolysis of biomass that potentially increases crop yields by reducing losses of nitrogen from soils and/or enhancing the uptake of applied fertiliser by the crops. Previous research is scarce about biochar's ability to increase wheat yields in temperate soils or how it changes nitrogen dynamics in the field. In a lysimeter system with two different soils (sandy/silt loam) nitrogen fluxes were traced by isotopic 15N enriched fertiliser to identify changes in nitrous oxide emissions, leaching and plant uptake after biochar addition. 20t/ha woodchip-waste biochar (pH=13) was applied to these soils in four lysimeters per soil type; the same number of lysimeters served as a control. The soils were cropped with winter wheat during the season 2012/2013. 170 kg-N/ha ammonium nitrate fertiliser with 10% 15N was applied in 3 events during the growing season and 15N concentrations where measured at different points in time in plant, soil, leachate and emitted nitrous oxide. After one year the lysimeter system showed no difference between biochar and control treatment in grain- and straw yield or nitrogen uptake. However biochar did reduce nitrous oxide emissions in the silt loam and losses of nitrate leaching in sandy loam. This study indicates potential reduction of nitrogen loss from cropland soil by biochar application but could not confirm increased yields in an intensive wheat production system.

  11. Assessment of soil hydrology variability of a new weighing lysimeter facility

    Science.gov (United States)

    Brown, S. E.; Wagner-Riddle, C.; Berg, A. A.

    2017-12-01

    Diversifying annual crop rotations is a strategy that mimics natural ecosystems and is postulated to increase agricultural resilience to climate change, soil quality and provision of soil ecosystem services. However, diverse cropping systems could increase soil mineral N levels and lead to greater leaching and/or N2O emissions; which raises the questions: (i) are diverse cropping systems actually beneficial for air and water quality? (ii) what are the trade-offs between soil, water, and air quality upon implementing a diverse cropping rotation? It can be difficult to fully evaluate the interactions between the two N-pollution pathways simultaneously in traditional field studies as drainage is largely unconstrained. Weighing lysimeters solve this issue by providing a closed system to measure N outputs via drainage and soil gas fluxes. A set of 18 weighting lysimeters were installed in Elora, Ontario, Canada in May 2016, to establish a long-term study of N-leaching and greenhouse gas emission from traditional and diverse cropping rotations for two different soil types. Each lysimeter is equipped with an automated chamber for continuous measurement of soil N2O and CO2 fluxes. A full characterization of variations of physical properties that may affect GHG emissions and N-leaching (e.g., soil temperature, moisture, drainage and evapotranspiration rates) amongst the lysimeters is required prior to application and assessment of the management treatments. Novel techniques such as wavelet analysis is required as standard statistical analyses are not applicable to the time series data. A full description of the lysimeters will be presented along with results of the characterization.

  12. Special wasteform lysimeter program at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    Oblath, S.B.; Stone, J.A.; Wiley, J.R.

    1983-01-01

    The Special Wasteform Lysimeter project at SRL is designed to measure performance of typical production-line, low-level, solid wasteforms produced at power reactors and emplaced in a himid SLB site. The use of lysimeters permits direct measurement of migration of radioactivity from these wasteforms to provide a technical basis for evaluating how well these forms will perform in an actual burial trench, and additionally allows comparison with unencapsulated defense waste. Cement and polymer wasteforms were place into 10 lysimeters in March 1982. By March, 1983, 60 Co from both types of wasteforms had been detected in te lysimeter sumps. 134 Cs, 137 Cs, and 60 Co were found in porous cup samplers located directly below the wasteforms. Measurements in mid-summer 1983 showed that 60 Co levels were 10 to 100 times greater in lysimeters containing the cement forms than in those containing the polymer. 5 references

  13. Special wasteform lysimeters initial three-year monitoring report

    International Nuclear Information System (INIS)

    Oblath, S.B.; Grant, M.W.

    1985-01-01

    Lysimeters containing ten typical commercial power reactor low-level wsteforms are in operation at the Savannah River Plant. This ten-year program is designed to measure the leaching and migration of radionuclides from these wasteforms under realistic burial ground conditions in a humid site. The data which the lysimeters provide serves as a technical basis for evaluating the performance of the wasteforms under actual burial conditions. Three years' operation of the lysimeters has demonstrated that all of the wasteforms perform excellently, with minimal releases of radioactivity. Cement-based wasteforms appear superior at retaining strontium. Polymer-based wasteforms appear superior at retaining cobalt and cesium isotopes. The releases of activity from the lysimeters are compared to the leaching behavior in immersion tests, with several differences noted. The conclusions drawn in this study are tentative, subject to the performance of the wasteforms after the lysimeters have been in operation for a longer period of time

  14. 1987 monitoring report for the defense waste lysimeters

    International Nuclear Information System (INIS)

    McIntyre, P.F.

    1987-01-01

    Low levels of radionuclides migrate through the soil to the sump. This report updates previous monitoring reports and discusses results obtained during the past year of operation. The effluents from the forty defense waste lysimeters continue to be analyzed on a monthly basis for gamma emitting radionuclides and quarterly for alpha emitting radionuclides and Sr-90. Cobalt-60, Sr-90, Sb-125, U-235, Pu-238, Pu-239 and Am-241 continue to be detected in sump effluent. Detectable levels of cobalt-60 and antimony-125 are each observed in only one lysimeter. Manganese-54, Ru-106 and Th-234 are no longer detected in effluent from any lysimeter. Significant levels of Sr-90 and Pu-238 are observed from several lysimeters, while others continue to show low levels of U-235, Pu-239 and Am-241. The release rates for transporting radionuclides through the soil to the sump indicate that migration is independent of whether a lysimeter is operated in a saturated or unsaturated mode. Pine trees continue to grow on the ten foot diameter lysimeters. No sampling of needles or woody stem portions was performed. The purpose of analyzing pine trees growing on lysimeters is to measure the amount of radionuclide uptake by the pine trees as their root systems come in contact with the waste material. 6 refs., 2 figs., 49 tabs

  15. Leaching of potassium in a lysimeter experiment

    International Nuclear Information System (INIS)

    Gerzabek, M.H.

    1996-11-01

    Leaching of potassium was studied in the lysimeter plant in Seibersdorf/Austria (Pannonian climate). Averaged over three years, gravitational water amounted to 15.7% of the sum of precipitation (mean 485 mm) and irrigation (mean 138 mm). Differences between the four soils with respect to drainage were explained by the specific percentage of the soil skeleton. The average yearly potassium leaching ranged from 3.64 kg K/ha·yr (Dystric-Cambisol) to 22.7 kg K/ha·yr (drained Gleysol). Correlation between gravitational water volume and potassium leaching were only significant for one out of four soil types. No correlation was observed between extractable potassium in the soil profiles and potassium leaching. (author)

  16. Integral Study of Atrazine Behaviour in Field Lysimeters in Argentinean Humid Pampas Soils Estudio Integral del Comportamiento de Atrazina en Lisímetros de Campo en Suelos de la Pampa Húmeda Argentina

    Directory of Open Access Journals (Sweden)

    Susana Hang

    2010-03-01

    Full Text Available Atrazine behavior during crop maize (Zea mays L. production in soils of Argentine humid pampas was investigated. Lysimeters (3.3 x 3.3 x 1.4 m with a Typic Argiudoll (Pergamino and others with a Typic Hapludoll (Junín were monitored for drainage water content and atrazine concentrations in soil and water. Soil profiles were sampled in four depths in three dates, and water drainage pooled in four periods. Most of atrazine loss in drainage occurred within 30 d of atrazine application being 0.13% and 0.03% of the total atrazine applied for Pergamino and Junín, respectively. Under laboratory conditions half-life average in both profiles was 16 d. Atrazine extractable residues (AER in lysimeters showed differences in quantity and distribution between both profiles. Extractable residues were 25.7 (Pergamino and 69.4 g ha-1 (Junín. At the 30th day of application, AER represented 25% of total AER in Junín and 88% in Pergamino in the first 30 cm. Occurrence of preferential flow through the Bt horizon (Pergamino may explain differences detected. High proportion of AER in Junín profile suggests low atrazine affinity and should be followed through time in order to evaluate actual stability of these residues and if they constitute a potential risk for aquifers.Se estudió el comportamiento de atrazina durante el ciclo de un cultivo de maíz (Zea mays L. en suelos de la pampa húmeda Argentina. Se monitoreó el total de agua drenada y la concentración de atrazina en suelo y agua, mediante el uso de seis lisímetros (3.3 x 3.3 x 1.4 m tres de ellos llenados con un Argiudoll Típico (Pergamino y otros tres con un Hapludoll Típico (Junín. Se tomaron muestras de cuatro horizontes en cada perfil de suelo en tres fechas y el agua drenada se agrupó en cuatro períodos. La mayor parte de las pérdidas de atrazina en el drenaje ocurrieron dentro de los primeros 30 días desde la aplicación de atrazina. Los porcentajes recuperados respecto de la cantidad

  17. Formation of secondary minerals in a lysimeter approach - A mineral-microbe interaction

    Science.gov (United States)

    Schäffner, F.; Merten, D.; De Giudici, G.; Beyer, A.; Akob, D. M.; Ricci, P. C.; Küsel, K.; Büchel, G.

    2012-04-01

    Heavy metal contamination of large areas due to uranium mining operations poses a serious long-term environmental problem. In the Ronneburg district (eastern Thuringia, Germany), leaching of low grade uranium bearing ores (uranium content metals, especially Cd, Ni, Co, Cu and Zn due to a residual contamination even after remediation efforts. To reveal the processes of secondary mineral precipitation in the field a laboratory lysimeter approach was set up under in situ-like conditions. Homogenized soil from the field site and pure quartz sand were used as substrates. In general, in situ measurements of redox potentials in the substrates showed highly oxidizing conditions (200-750 mV). Water was supplied to the lysimeter from below via a mariottés bottle containing contaminated groundwater from the field. Evaporation processes were allowed, providing a continuous flow of water. This led to precipitation of epsomite and probably aplowite on the top layer of substrate, similar to what is observed in field investigations. After 4 weeks, the first iron and manganese bearing secondary minerals became visible. Soil water samples were used to monitor the behaviour of metals within the lysimeter. Saturation indices (SI) for different secondary minerals were calculated with PHREEQC. The SI of goethite showed oversaturation with respect to the soil solution. SEM-EDX analyses and IR spectroscopy confirmed the formation of goethite. Geochemical data revealed that goethite formation was mainly dominated by Eh/pH processes and that heavy metals, e.g. Zn and U, could be enriched in this phase. Although Eh/pH data does not support formation of manganese minerals, Mn(II)-oxidizing bacteria (MOB) could be isolated from field soil samples, supporting the fact that microorganisms may influence this natural attenuation process. Laser ablation ICP-MS data reveal accumulation of manganese in MOB biomass on Mn(II)-containing agar plates. Furthermore, it was possible to show the importance

  18. Lysimeter study of vegetative uptake from saltstone. Part I. Design, installation, and data collection plan

    International Nuclear Information System (INIS)

    Johnson, T.L.

    1986-02-01

    A field test facility has been designed and installed to obtain data on the vegetative uptake of radionuclides from buried low-level radioactive waste. The waste is a cement-like, solidified salt solution known as saltstone. The facility consists of 32 lysimeters (containers 6 feet in diameter and 6 to 10 feet in depth) holding buried saltstone at varying depths, and with varying types of vegetation grown at the surface. Vegetation, soil, and groundwater samples will be analyzed for Tc-99, Sr-90, I-129, Cs-137, and other radionuclides. Groundwater will also be analyzed for other water quality parameters, including nitrates

  19. Instrumentation of Lysimeter Experiments and Monitoring of Soil Parameters

    International Nuclear Information System (INIS)

    Schmid, T.; Tallos, A.; Millan, R.; Vera, R.; Recreo, F.

    2004-01-01

    This study forms part of the project Mercurio and Recuperation de Terrenos Afectados por Mercurio Ambiental (RETAMA) , which determines the behaviour of mercury in the soil-plant system within the area of Almaden. The objective of this work is to instrument lysimeters with a set of electronic sensors to monitor physical and chemical soil parameters (moisture content, soil temperature, soil water matrix potential, Eh and pH) over a period of a complete vegetation cycle for selected crops. Physical and chemical soil analyses have been carried out on samples two soil profiles marking the extreme perimeter where the lysimeters were extracted. The monitoring data obtained every half hour show that the physicochemical conditions of the soils in the lysimeter can be correlated with the type of cultivation in the lysimeters. The results for parameters such as soil water matrix potential and the soil temperature reflect the diurnal changes; and fluctuations of the Eh can be related to the biological activities in the soils and are within oxid and sub oxid conditions. Slight fluctuations have been observed for the pH and constant volumetric moisture content is maintained during the period of no hydric stress. (Author) 16 refs

  20. Instrumentation of Lysimeter Experiments and Monitoring of Soil Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, T.; Tallos, A.; Millan, R.; Vera, R.; Recreo, F.

    2004-07-01

    This study forms part of the project Mercurio and Recuperation de Terrenos Afectados por Mercurio Ambiental (RETAMA), which determines the behaviour of mercury in the soil-plant system within the area of Almaden. The objective of this work is to instrument lysimeters with a set of electronic sensors to monitor physical and chemical soil parameters (moisture content, soil temperature, soil water matrix potential. Eh and pH) over a period of a complete vegetation cycle for selected crops. Physical and chemical soil analyses have been carried out on samples two soil profiles marking the extreme perimeter where the lysimeters were extracted. The monitoring data obtained every half hour show that the physicochemical conditions of the soils in the lysimeter can be correlated with the type of cultivation in the lysimeters. The results for parameters such as soil water matrix potential and the soil temperature reflect the diurnal changes; and fluctuations of the Eh can be related to the biological activities in the soils and are within oxid and suboxic conditions. Slight fluctuations have been observed for the pH and constant volumetric moisture content is maintained during the period of no hydric stress. (Author) 16 refs.

  1. Precipitation and evapotranspiration at the mountain lysimeter station Stoderzinken

    Science.gov (United States)

    Herndl, Markus; Winkler, Gerfried; Birk, Steffen

    2014-05-01

    Alpine water resources are highly important for the Austrian drinking water supply. In particular, the Northern Calcareous Alps contribute substantially to both the regional and the national drinking water supply. To analyse water balance, runoff and recharge in a representative mountain pasture area in the Northern Calcareous Alps a lysimeter station was established at the mountain Stoderzinken (1830 m a.s.l.) in 2005. This work examines the water balance at the lysimeter station during one summer period. Precipitation and evapotranspiration are determined using various approaches in order to identify potential errors in the measurement or interpretation of the data and thus to assess the uncertainties in the water balance components. For this purpose, data of rain gauges and a distrometer was compared with the precipitation calculated from the water balance of the lysimeter. Furthermore evapotranspiration was calculated using the HAUDE and PENMAN-MONTEITH equations for comparison. Already in previous seasons the distrometer was found to be prone to errors, which was confirmed when compared to the rain gauge data. In contrast, precipitation rates calculated from the lysimeter data were found to agree better with the rain gauge data but showed a trend to higher values. However, the approach to calculate precipitation from the lysimeter data turned out to be unsuitable for time periods with significant contribution of snow melt. Evapotranspiration calculated from lysimeter data are in good agreement with the results from the above-mentioned (semi-)empirical equations during dry periods. Furthermore the differences to the evapotranspiration calculated from the climate data correlate with the amount of precipitation. These results suggest that in alpine catchments the uncertainty in the precipitation data constitutes the major source of error in the calculation of evapotranspiration from the water balance of the lysimeter. However, it should be noted that these

  2. Revisiting hydraulic hysteresis based on long-term monitoring of hydraulic states in lysimeters

    Science.gov (United States)

    Hannes, M.; Wollschläger, U.; Wöhling, T.; Vogel, H.-J.

    2016-05-01

    Hysteretic processes have been recognized for decades as an important characteristic of soil hydraulic behavior. Several studies confirmed that wetting and drying periods cannot be described by a simple functional relationship, and that some nonequilibrium of the water retention characteristics has to be taken into account. A large number of models describing the hysteresis of the soil water retention characteristic were successfully tested on soil cores under controlled laboratory conditions. However, its relevance under field conditions under natural forcings has rarely been investigated. In practice, the modeling of field soils usually neglects the hysteretic nature of soil hydraulic properties. In this study, long-term observations of water content and matric potential in lysimeters of the lysimeter network TERENO-SoilCan are presented, clearly demonstrating the hysteretic behavior of field soils. We propose a classification into three categories related to different time scales. Based on synthetic and long-term monitoring data, three different models of hysteresis were applied to data sets showing different degrees of hysteresis. We found no single model to be superior to the others. The model ranking depended on the degree of hysteresis. All models were able to reflect the general structure of hysteresis in most cases but failed to reproduce the detailed trajectories of state variables especially under highly transient conditions. As an important result we found that the temporal dynamics of wetting and drying significantly affects these trajectories which should be accounted for in future model concepts.

  3. Large-scale demonstration of disposal of decontaminated salt as saltstone. Part I. Construction, loading, and capping of lysimeters

    International Nuclear Information System (INIS)

    Wolf, H.C.

    1984-06-01

    The installation phase of a large-scale demonstration of the disposal concept for decontaminated, low-level radioactive salt waste at the Savannah River Plant was completed in December 1983 and January 1984. The installation entailed immobilizing 7500 gallons of decontaminated salt solution with a blended cement formulation and pouring the resulting grout, saltstone, into three specially designed lysimeters for extended in-field leaching tests under natural conditions. 4 references, 35 figures, 4 tables

  4. Mathematical modelling of the performance of hydrodynamic couplings using hybrid models; Mathematische Modellierung des Betriebsverhaltens hydrodynamischer Kupplungen mit hybriden Modellansaetzen

    Energy Technology Data Exchange (ETDEWEB)

    Jaschke, P.

    2000-02-01

    Mathematical models of the dynamic performance of hydrodynamic couplings are developed using hybrid modelling, i.e. a combination of analytical physical modelling and black box identification. The models developed were verified by measurements on a model powertrain. [German] In dieser Arbeit werden mit Hilfe der hybriden Modellierung mathematische Modelle zur Beschreibung des dynamischen Betriebsverhaltens hydrodynamischer Kupplungen ermittelt. Die Hybride Modellierung stellt eine Kombination der analytisch physikalischen Modellierung und der Black-Box-Identifikation dar. Diese Modellierungsart ist ausgewaehlt worden, um die Vorteile der analytisch physikalischen Modellierung und der Black-Box-Identifikation hydrodynamischer Kupplungen zu verbinden und deren Nachteile gering zu halten. Auf dieser Basis ist eine Vorgehensweise vorgestellt worden, die die Ermittlung der Modelle mit wenig Aufwand ermoeglicht. Mit Hilfe der Modelltheorie wird gezeigt, wie die ermittelten mathematischen Modelle zur Simulation des dynamischen Betriebsverhaltens geometrisch aehnlicher Kupplungen unterschiedlicher Baugroessen verwendet werden koennen. Darueber hinaus wird dargelegt, wie die ermittelten Modelle mit Modellen anderer Antriebsstrangelemente gekoppelt werden koennen, um Antriebsstrangsimulationen zu ermoeglichen. Verifikationsmessungen an einem Modellantriebsstrang verdeutlichen die Guete und Verwendbarkeit der mathematischen Modelle. (orig.)

  5. Ground-penetrating radar (GPR) responses for sub-surface salt contamination and solid waste: modeling and controlled lysimeter studies.

    Science.gov (United States)

    Wijewardana, Y N S; Shilpadi, A T; Mowjood, M I M; Kawamoto, K; Galagedara, L W

    2017-02-01

    The assessment of polluted areas and municipal solid waste (MSW) sites using non-destructive geophysical methods is timely and much needed in the field of environmental monitoring and management. The objectives of this study are (i) to evaluate the ground-penetrating radar (GPR) wave responses as a result of different electrical conductivity (EC) in groundwater and (ii) to conduct MSW stratification using a controlled lysimeter and modeling approach. A GPR wave simulation was carried out using GprMax2D software, and the field test was done on two lysimeters that were filled with sand (Lysimeter-1) and MSW (Lysimeter-2). A Pulse EKKO-Pro GPR system with 200- and 500-MHz center frequency antennae was used to collect GPR field data. Amplitudes of GPR-reflected waves (sub-surface reflectors and water table) were studied under different EC levels injected to the water table. Modeling results revealed that the signal strength of the reflected wave decreases with increasing EC levels and the disappearance of the subsurface reflection and wave amplitude reaching zero at higher EC levels (when EC >0.28 S/m). Further, when the EC level was high, the plume thickness did not have a significant effect on the amplitude of the reflected wave. However, it was also found that reflected signal strength decreases with increasing plume thickness at a given EC level. 2D GPR profile images under wet conditions showed stratification of the waste layers and relative thickness, but it was difficult to resolve the waste layers under dry conditions. These results show that the GPR as a non-destructive method with a relatively larger sample volume can be used to identify highly polluted areas with inorganic contaminants in groundwater and waste stratification. The current methods of MSW dumpsite investigation are tedious, destructive, time consuming, costly, and provide only point-scale measurements. However, further research is needed to verify the results under heterogeneous aquifer

  6. Verification SEBAL and Hargreaves –Samani Models to Estimate Evapotranspiration by Lysimeter Data

    Directory of Open Access Journals (Sweden)

    Ali Morshedi

    2017-02-01

    Full Text Available Introduction: Evapotranspiration (ET is an important component of the hydrological cycle, energy equations at the surface and water balance. ET estimation is needed in various fields of science, such as hydrology, agriculture, forestry and pasture, and water resources management. Conventional methods used to estimate evapotranspiration from point measurements. Remote sensing models have the capability to estimate ET using surface albedo, surface temperature and vegetation indices in larger scales. Surface Energy Balance Algorithm for Land (SEBAL estimate ET at the moment of satellite path as a residual of energy balance equation for each pixel. In this study Hargreaves-Samani (HS and SEBAL models ET compared to an alfalfa lysimeter data’s, located in Shahrekord plain within the Karun basin. Satellite imageries were based on Landsat 7 ETM+ sensor data’s in seven satellite passes for path 164 and row 38 in the World Reference System, similar to lysimeter sampling data period, from April to October 2011. SEBAL uses the energy balance equation to estimate evapotranspiration. Equation No. 1 shows the energy balance equation for an evaporative surface: λET=Rn–G–H [1] In this equation Rn, H, G and λET represent the net radiation flux input to the surface (W/m2, Sensible heat flux (W/m2, soil heat flux (W/m2, and latent heat of vaporization (W/m2, respectively. In this equation the vertical flux considered and the horizontal fluxes of energy are neglected. The above equation must be used for large surfaces and uniformly full cover plant area. SEBAL is provided for estimating ET, using the minimum data measured by ground equipment. This model is applied and tested in more than 30 countries with an accuracy of about 85% at field scale, and 95 percent in the daily and seasonal scales. In Borkhar watershed (East of Isfahan, IRAN ASTER and MODIS satellite imageries were used for SEBAL to compare Penman-Monteith model. Results showed that estimated

  7. Device for applying organic chemicals to lysimeter surfaces; Applikationsvorrichtung fuer organische Chemikalien auf Lysimeteroberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Schroll, R. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Bodenoekologie

    1999-02-01

    One of the aims of environmental research at the GSF Research Centre for the Environment and Health is to determine the behaviour of environmentally consequential chemicals in terrestrial ecosystems under as natural conditions as possible. The GSF lysimeter plant in Neuherberg permits studying the environmental behaviour of organic chemicals in different soils. Collaborators at GSF have developed a means of applying -14-marked substances in field lysimeters so as to be able to refind released chemicals, identify their conversion products and set up mass balances for the chemicals. [Deutsch] Ein Ziel der Umweltforschung im GSF-Forschungszentrum fuer Umwelt und Gesundheit ist es, das Verhalten von Umweltchemikalien in terrestrischen Oekosystemen unter moeglichst natuerlichen Bedingungen zu bestimmen. In der GSF-Lysimeteranlage Neuherberg kann das Umweltverhalten von Organika in verschiedenen Boeden untersucht werden. Zur Wiedererkennung der ausgebrachten Chemikalie bzw. zur Identifizierung aus ihr entstandener Umwandlungsprodukte und letztendlich auch zur Erstellung einer Massenbilanz fuer das ausgebrachte Praeparat wurde in der GSF die Moeglichkeit geschaffen, {sup 14}C-markierte Substanzen in Freilandlysimetern applizieren zu koennen. (orig.)

  8. Upward migration of radio-cesium and strontium in a sand-filled lysimeter

    International Nuclear Information System (INIS)

    Sanford, W.E.; Larsen, I.L.; McConnell, J.W.; Rogers, R.D.

    1998-01-01

    The upward migration of 134 Cs, 137 Cs, and 90 Sr was observed in a silica sand-filled lysimeter at the Field Lysimeter Investigations: Low Level Waste Data Base Development experiment site at Oak Ridge National Laboratory. The source of the radionuclides first observed on the surface was identified from isotopic analysis as being from the buried waste. Cores of the sand were collected and analyzed for the vertical distribution of the radionuclides. Results of analyses revealed that pulses (elevated levels) in the activity of the Cs and Sr radioisotopes occurred at the same depths. During the sectioning of the sand core collected from directly above the buried waste form it was discovered that a fine root from an unidentified plant was present throughout all but the upper few centimeters of the core. Because the upward migration was unexpected, information that may lead to the determination of a definitive mechanism of migration was not preserved. The distribution of the radionuclides coupled with the presence of the root suggest that Cs and Sr migrated upward in the evapotranspiration stream of the root. Further study must be undertaken to confirm this phenomenon. Upward migration of radionuclides as observed here could result in direct exposures and offsite releases from underground storage facilities. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Construction and evaluation of simulated pilot scale landfill lysimeter in Bangladesh.

    Science.gov (United States)

    Rafizul, Islam M; Howlader, Milon Kanti; Alamgir, Muhammed

    2012-11-01

    This research concentrates the design, construction and evaluation of simulated pilot scale landfill lysimeter at KUET campus, Khulna, Bangladesh. Both the aerobic and anaerobic conditions having a base liner and two different types of cap liner were simulated. After the design of a reference cell, the construction of landfill lysimeter was started in January 2008 and completed in July 2008. In all construction process locally available civil construction materials were used. The municipal solid waste (MSW) of 2800-2985 kg having the total volume of 2.80 m(3) (height 1.6 m) and moisture content of 65% was deposited in each lysimeter by applying required compaction energy. In contrast, both the composition in terms of methane (CH(4)), carbon dioxide (CO(2)) and oxygen (O(2)) as well as the flow rate of landfill gas (LFG) generated from MSW in landfill lysimeter were measured and varied significantly in relation to the variation of lysimeter operational condition. Moreover, anaerobic lysimeter-C shows the highest composition of LFG in compare to the anaerobic lysimeter-B due to the providing of lower compaction of cap liner in anaerobic lysimeter-C. Here, it is interesting to note that in absence of compacted clay liner (CCL) and hence percolation of rainwater that facilitates rapid degradation of MSW in aerobic lysimeter-A has resulted in the highest settlement than that of anaerobic landfill lysimeter-B and C. Moreover, in case of anaerobic lysimeter-B and C, the leachate generation was lower than that of aerobic lysimeter-A due to the providing of cap liner in anaerobic lysimeter-B and C, played an important role to reduce the percolation of rainwater. The study also reveals that the leachate pollution index (LPI) has decreased in relation to the increasing of elapsed period as well as the LPI for collection system of aerobic lysimeter-A was higher than that of the collection system of anaerobic lysimeter-B and C. Finally, it can be depicted that LPI for lysimeter

  10. Tritium tracing in hydrogeochemical studies using model-lysimeters

    International Nuclear Information System (INIS)

    Matthess, G.; Pekdeger, A.; Schulz, H.D.; Rast, H.; Rauert, W.

    1978-01-01

    Tritium was used as a reference tracer for hydrogeochemical studies in the unsaturated zone. The investigators used different lysimeter types (25, 50, 100 cm), with and without suction plates filled with undisturbed soil monoliths of sandy podsol and loamy lessive. The tritium loss was greater than the evaporation amount determined. Water logging takes place in lysimeter bottoms increasing the evaporation in up to 100 cm lysimeters filled with loamy lessive and 25 cm with sandy podsol. After a 20 mm rain event seepage characteristics indicate 'by-passing' water besides intergranular seepage. Dispersion coefficients (8.5 x 10 -5 cm 2 s -1 ) are higher than molecular diffusion coefficient. Dispersion takes place mainly in top soil with wide ranging pore size distribution. Distribution coefficients of tritium in soil are rather low. Concentrations of anions and dissolved organic substance are different depending on residence time of seepage water in soil. Even a short residence time of seepage water in unsaturated soil is enough for cation exchange reactions to take place. (orig.) [de

  11. African Mahogany transpiration with Granier method and water table lysimeter

    Directory of Open Access Journals (Sweden)

    Ana C. O. Sérvulo

    Full Text Available ABSTRACT The thermal dissipation probe (Granier method is useful in the water deficit monitoring and irrigation management of African Mahogany, but its model needs proper adjustment. This paper aimed to adjust and validate the Granier sap flux model to estimate African Mahogany transpiration, measure transpiration using lysimeter and relate it to atmospheric water demand. Weather conditions, transpiration and sap flux were monitored in three units of 2.5-year-old African Mahogany trees in constant water table lysimeter, in Goiânia, GO. Sapwood area (SA, leaf area (LA, transpiration measured by lysimeter (TLYS and estimated by sap flux (TSF were evaluated. The SA comprised 55.24% of the trunk’s transversal section. The LA varied from 11.95 to 10.66 m2. TLYS and TSF varied from 2.94 to 29.31 and from 0.94 to 15.45 L d-1, respectively. The original model underestimated transpiration by 44.4%, being the adjusted equation F = 268.25 . k1.231. SA was significant (F < 0.05. Due the root confinement, the transpiration showed low correlation, but positive, with the atmospheric water demand.

  12. Design of top covers supporting aerobic in situ stabilization of old landfills - An experimental simulation in lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Hrad, Marlies [Institute of Waste Management, Department of Water-Atmosphere-Environment, University of Natural Resources and Life Sciences, Muthgasse 107, 1190 Vienna (Austria); Huber-Humer, Marion, E-mail: marion.huber-humer@boku.ac.at [Institute of Waste Management, Department of Water-Atmosphere-Environment, University of Natural Resources and Life Sciences, Muthgasse 107, 1190 Vienna (Austria); Wimmer, Bernhard; Reichenauer, Thomas G. [Health and Environment Department, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Tested engineered covers as surrogate to gas extraction during and after in situ aeration. Black-Right-Pointing-Pointer Examined how covers influence gas emissions, water balance and leachate generation. Black-Right-Pointing-Pointer Investigated effect of top covers on air-distribution in waste mass during aeration. Black-Right-Pointing-Pointer We suggest criteria and cover design to meet the demands during and after aeration. Black-Right-Pointing-Pointer Such cover systems may offer greenhouse gas emission reduction also after active aeration. - Abstract: Landfill aeration by means of low pressure air injection is a promising tool to reduce long term emissions from organic waste fractions through accelerated biological stabilization. Top covers that enhance methane oxidation could provide a simple and economic way to mitigate residual greenhouse gas emissions from in situ aerated landfills, and may replace off-gas extraction and treatment, particularly at smaller and older sites. In this respect the installation of a landfill cover system adjusted to the forced-aerated landfill body is of great significance. Investigations into large scale lysimeters (2 Multiplication-Sign 2 Multiplication-Sign 3 m) under field conditions have been carried out using different top covers including compost materials and natural soils as a surrogate to gas extraction during active low pressure aeration. In the present study, the emission behaviour as well as the water balance performance of the lysimeters has been investigated, both prior to and during the first months of in situ aeration. Results reveal that mature sewage sludge compost (SSC) placed in one lysimeter exhibits in principle optimal ambient conditions for methanotrophic bacteria to enhance methane oxidation. Under laboratory conditions the mature compost mitigated CH{sub 4} loadings up to 300 l CH{sub 4}/m{sup 2} d. In addition, the compost material provided high air permeability

  13. Characterization and tropical seasonal variation of leachate: results from landfill lysimeter studied.

    Science.gov (United States)

    Rafizul, Islam M; Alamgir, Muhammed

    2012-11-01

    This study aims to characterize the leachate and to investigate the tropical climatic influence on leachate characteristics of lysimeter studies under different seasonal variations at KUET campus, Bangladesh. Three different situations of landfill were considered here as well as both the open dump lysimeter-A having a base liner and sanitary landfill lysimeter-B and C at two different types of cap liner were simulated. The leachate characteristics, leachate generation and climatic influence parameter had been continually monitored since June 2008 to May 2010, these periods cover both the dry and rainy season. The leachate generation had followed the rainfall pattern and the open dump lysimeter-A without top cover was recorded to have highest leachate generation. Moreover, the open dump lysimeter-A had lower total kjeldahl nitrogen (TKN), ammonia nitrogen (NH(4)-N) and TKN load, while both the COD concentration and load was higher compared with sanitary landfill lysimeter-B and C. In addition, sanitary landfill lysimeter-B, not only had lowest leachate generation, but also produces reasonable low COD concentration and load compared with open dump lysimeter-A. Result reveals that lysimeter operational mode had direct effect on leachate quality. Finally, it can be concluded that the knowledge of leachate quality will be useful in planning and providing remedial measures of proper liner system in sanitary landfill design and leachate treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Annual Report for Gravity Collection Lysimeter Monitoring Plan - ERDF Cells 5 and 6

    International Nuclear Information System (INIS)

    Remsen, W.E.

    2006-01-01

    The objectives of the Annual Report are to: (1) describe changes in the volume of liquid seen in each lysimeter, (2) describe concentrations and changes or trends in the concentrations of leachate-indicator constituents in any liquids accumulated in each lysimeter, (3) summarize the finding in regard to the presence or absence of leachate in each lysimeter, (4) make recommendations, if any, limited to vadose-zone study-related variables. The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters.

  15. Upscaling of lysimeter measurements to regional groundwater nitrate distribution

    Science.gov (United States)

    Klammler, Gernot; Fank, Johann; Kupfersberger, Hans; Rock, Gerhard

    2015-04-01

    For many European countries nitrate leaching from the soil zone into the aquifer due to surplus application of mineral fertilizer and animal manure by farmers constitutes the most important threat to groundwater quality. This is a diffuse pollution situation and measures to change agricultural production have to be investigated at the aquifer scale to safeguard drinking water supply from shallow groundwater resources Lysimeters are state-of-the-art measurements for water and solute fluxes through the unsaturated zone towards groundwater at the point scale, but due to regional heterogeneities (especially concerning soil conditions) lysimeters cannot provide aquifer-wide groundwater recharge and solute leaching. Thus, in this work the numerical simulation model SIMWASER/STOTRASIM (Stenitzer, 1988; Feichtinger, 1998) for quantifying groundwater recharge and nitrate leaching at aquifer scale is applied. Nevertheless, according to Groenendijk et al. (2014) a model calibration by means of lysimeter measurements is essential, since uncalibrated models are generally far from acceptable. Thus, a lysimeter provides the basis for the parameterization of numerical simulation models. To quantify also the impact on regional nitrate distribution in the groundwater, we couple the unsaturated zone model SIMWASER/STOTRASIM with the saturated groundwater flow and solute transport model FELOW (Diersch, 2009) sequentially. In principal, the problem could be solved by the 3 dimensional equation describing variable saturated groundwater flow and solute transport. However, this is computationally prohibitive due to the temporal and spatial scope of the task, particularly in the framework of running numerous simulations to compromise between conflicting interests (i.e. good groundwater status and high agricultural yield). To account for the unknown regional distribution of crops grown and amount, timing and kind of fertilizers used a stochastic tool (Klammler et al, 2011) is developed that

  16. Construction and demolition waste: Comparison of standard up-flow column and down-flow lysimeter leaching tests.

    Science.gov (United States)

    Butera, Stefania; Hyks, Jiri; Christensen, Thomas H; Astrup, Thomas F

    2015-09-01

    Five samples of construction and demolition waste (C&DW) were investigated in order to quantify leaching of inorganic elements under percolation conditions according to two different experimental setups: standardised up-flow saturated columns (<4mm particle size) and unsaturated, intermittent down-flow lysimeters (<40mm particle size). While standardised column tests are meant primarily to provide basic information on characteristic leaching properties and mechanisms and not to reproduce field conditions, the lysimeters were intended to mimic the actual leaching conditions when C&DW is used in unbound geotechnical layers. In practice, results from standardised percolation tests are often interpreted as estimations of actual release from solid materials in percolation scenarios. In general, the two tests yielded fairly similar results in terms of cumulative release at liquid-to-solid ratio (L/S) 10l·kgTS; however, significant differences were observed for P, Pb, Ba, Mg and Zn. Further differences emerged in terms of concentration in the early eluates (L/S<5l·kg(-1)TS) for Al, As, Ba, Cd, Cu, DOC, Mg, Mn, Ni, P, Pb, Sb, Se, Si, Zn. Observed differences between tests are likely to be due to differences in pH related to crushing and exposure of fresh particle surfaces, as well as in equilibrium conditions. In the case of C&DW, the standardised column tests, which are more practical, are considered to acceptably describe cumulative releases at L/S 10l·kg(-1)TS in percolation scenarios. However, when the focus is on estimation of initial concentrations for (for example) risk assessment, data from standardised column tests may not be fully applicable, and data from lysimeters may be used for validation purposes. Se, Cr and, to a lesser extent, SO4 and Sb were leaching from C&DW in critical amounts compared with existing limit values. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Three-dimensional mathematical modelling of a proton-exchange membrane fuel cell (PEMFC); Dreidimensionale mathematische Modellierung einer Brennstoffzelle mit Protonen-Austausch-Membran (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Mosig, J

    1997-12-01

    physikochemischen Vorgaenge. Mathematische Simulationen koennen zu diesem Verstaendnis in erheblichem Masse beitragen. In der vorliegenden Arbeit wird ein mathematisches Modell vorgestellt, welches die Berechnung der Massen- und Ladungsstroeme in den unterschiedlichen Materialschichten einer rechteckigen, planaren PEM-Brennstoffzelle ermoeglicht und die entsprechenden dreidimensionalen Konzentrations- und Potentialverteilungen liefert. Die Simulationssoftware ermoeglicht die stationaere und isotherme Berechnung von Wasserstoff/Luft-Einzelzellen, denen Brenngas und Oxidans unter realitaetsnahen Bedingungen in Gleich-, Gegen- oder Kreuzstromfuehrung zugefuehrt werden koennen. Die mathematische Loesungsmethode basiert auf der Methode der finiten Volumenelemente. Die aus der Diskretisierung der Erhaltungsgleichungen resultierenden grossen, duennbesetzten Gleichungssysteme werden mittels eines Mehrgitterverfahrens sehr effizient geloest. Der Vergleich berechneter Stormdichte/Spannungskennlinien fuer eine Basisfallzelle mit gemessenen Stromdichte/Spannungskennlinien belegt die gute Qualitaet der Simulationsergebnisse. Parametervariationen zeigen die Abhaengigkeit der Elektrodenkinetik von der Zelltemperatur und von den Gasdruecken auf der Brenngas- und Luftseite auf. Weiterhin wird der Einfluss der Druckdifferenz zwischen Brenngas und Oxidans auf den Wasserhaushalt der Elektrolytmembran untersucht. Abschliessend zeigen Simulationsrechnungen fuer verschiedene Brennstoffzellenmaterialien und Verhaeltnisse von Gaskanal- zu Stegbreite den Einfluss konstruktiver Brennstoffzellenparameter auf die Leistungsfaehigkeit einer PEM-Brennstoffzelle. (orig.)

  18. Model validation studies of water flow and radionuclide transport in vegetated soils using lysimeter data

    Energy Technology Data Exchange (ETDEWEB)

    Butler, A.; Jining Chen [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [and others

    1996-09-01

    involved in tritium assessment, with the opportunity to test this component of their codes. In total six groups participated in the study, three groups undertaking solely hydrological simulations, the other three also including radionuclide transport. One factor which was soon identified was, owing to previous applications and development objectives, some of the models had structural forms which were inappropriate for the lysimeter scenario. In many cases participants found that they had difficulty applying the fixed water table and specified concentration boundary conditions to their models. This immediately introduced a degree of uncertainty into the model simulations. In other instances the onset of free drainage once the soil moisture reached a specified 'field capacity' led to marked discrepancies between simulated and observed hydrological data. In addition, the manner in which this free drainage mobilised radionuclides also had an important bearing on soil radioactivity profiles. The manner in which modelers selected parameter values was an important aspect of the user interpretation component of the study. Where appropriate, modelers sought to derive parameter values from the supplied data. However, in one instance a more generic approach to the identification of hydrological parameters resulted in model behaviour which was markedly different from the experimental data. This identified a discrepancy in the soil physical textural analysis and the measured hydraulic parameters compared with standard classification schemes. The effect of user interpretation on parameter selection was also clearly seen in the choice of the soil sorption K{sub d} values. One group tended to take a rather conservative view in order to provide a 'worst case' scenario, whereas in the other erred towards significantly higher values. The degree of discretization used by the various models played an important role in the dispersive transport of radionuclides up the soil

  19. Model validation studies of water flow and radionuclide transport in vegetated soils using lysimeter data

    International Nuclear Information System (INIS)

    Butler, A.; Jining Chen

    1996-09-01

    assessment, with the opportunity to test this component of their codes. In total six groups participated in the study, three groups undertaking solely hydrological simulations, the other three also including radionuclide transport. One factor which was soon identified was, owing to previous applications and development objectives, some of the models had structural forms which were inappropriate for the lysimeter scenario. In many cases participants found that they had difficulty applying the fixed water table and specified concentration boundary conditions to their models. This immediately introduced a degree of uncertainty into the model simulations. In other instances the onset of free drainage once the soil moisture reached a specified 'field capacity' led to marked discrepancies between simulated and observed hydrological data. In addition, the manner in which this free drainage mobilised radionuclides also had an important bearing on soil radioactivity profiles. The manner in which modelers selected parameter values was an important aspect of the user interpretation component of the study. Where appropriate, modelers sought to derive parameter values from the supplied data. However, in one instance a more generic approach to the identification of hydrological parameters resulted in model behaviour which was markedly different from the experimental data. This identified a discrepancy in the soil physical textural analysis and the measured hydraulic parameters compared with standard classification schemes. The effect of user interpretation on parameter selection was also clearly seen in the choice of the soil sorption K d values. One group tended to take a rather conservative view in order to provide a 'worst case' scenario, whereas in the other erred towards significantly higher values. The degree of discretization used by the various models played an important role in the dispersive transport of radionuclides up the soil profile. This, in turn, revealed a strong

  20. Mathematical modelling and laser measurement technique of combustion processes. Final report 1994-1996; Mathematische Modellierung und Lasermesstechnik von Verbrennungsvorgaengen. Abschlussbericht 1994 - 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    Due to financial boundary conditions and greater industrially orientated targets, the project was restructured in its third phase. The general theme `Mathematical modelling and laser measurement technique of combustion processes` was made more precise by the central questions of the Sub-heading `Modelling and validation`. It applies equally as target for the three part projects (a) Modelling process, (b) Standard flames (c) Coal and solid combustion, soot formation, radiation. Due to the preliminary work done, good progress was achieved in all projects, in some cases discoveries were made and new types of projects were developed. The quality and quantity of the basic data as input parameters for modelling and validation data as test parameters for the prediction of the models was expanded further by comparison of different methods of measurement. [Deutsch] Aufgrund der finanziellen Randbedingungen und der staerker industrieorientierten Zielsetzungen wurde das Projekt in seiner dritten Phase neu strukturiert. Das Generalthema `Mathematische Modellierung und Lasermesstechnik von Verbrennungsvorgaengen` wurde um die zentralen Fragestellungen als Zwischenueberschrift praezisiert: `Modellierung und Validierung`. Sie gilt fuer die drei Teilprojekt (a) Modellierungsverfahren (b) Standardflammen (c) Kohle- und Feststoffverbrennung, Russbildung, Strahlung in gleichem Mass als Zielsetzung. In allen Vorhaben konnten aufgrund der geleisteten Vorarbeit gute Fortschritte erzielt werden, in einigen Faellen Entdeckungen gemacht und neuartige Verfahren entwickelt werden. Die Qualitaet und Quantitaet der Basisdaten als Eingangsgroessen fuer die Modellierung und der Validierungsdaten als Testgroessen fuer die Voraussagen der Modelle konnten durch Vergleich unterschiedlicher Messmethoden generell weiter ausgebaut werden. (orig.)

  1. Performance of special wasteform lysimeters and waste migration at a humid site

    International Nuclear Information System (INIS)

    McIntyre, P.F.

    1986-01-01

    The special wasteform lysimeter (SWL) program at the Savannah River Laboratory (SRL) near Aiken, South Carolina, is designed to measure leaching behavior and radionuclide migration under realistic burial conditions at a humid site. A similar program at an arid site is being conducted at Hanford near Richland, Washington. The wasteforms were placed in the lysimeters in March 1982 and represent typical low-level waste from two commercial reactors. An extensive report covering the initial three years of operation was issued in November 1985. This report updates the results of that report and includes significant observations made during the past year of operation. The Waste Migration Program at SRL included continued monitoring of 40 defense waste lysimeters, radionuclide uptake by pine trees, and measurement of total organic carbon in the groundwater of the burial ground

  2. Performance of special wasteform lysimeters and waste migration at a humid site

    International Nuclear Information System (INIS)

    McIntyre, P.F.

    1987-01-01

    The special wasteform lysimeter (SWL) program at the Savannah River Laboratory (SRL) near Aiken, South Carolina is designed to measure leaching behavior and radionuclide migration under realistic burial conditions at a humid site. A similar program at an arid site is being conducted at Hanford near Richland, Washington. The wasteforms were placed in the lysimeters in March 1982 and represent typical low-level waste from two commercial reactors. An extensive report covering the initial three years of operation was issued in November 1985. This report updates the results of that report and includes significant observations made during the past year of operation. The Waste Migration Program at SRL included continued monitoring of 40 defense waste lysimeters, radionuclide uptake by pine trees, and measurement of total organic carbon in the ground water of the burial ground. 5 references, 2 figures, 5 tables

  3. The influence of the lysimeter filling on the soil monolith inside

    Science.gov (United States)

    Puetz, T.; Schilling, J.; Vereecken, H.

    2009-04-01

    In general, lysimeters are vessels containing disturbed or undisturbed soil blocks, for the most realistic scenario with regard to real outdoor conditions an undisturbed soil block so called soil monolith is preferable. The lower boundary condition was realized in two different ways: as a zero-tension lysimeter with a perforated bottom plate or as controlled lower boundary condition with a suction plate. The optimal surface area and the lysimeter length depend mainly on the scientific question. For cropped lysimeter experiments the lysimeter length has to reflect to a maximum root length. The base area is strongly connected to the scale of observation, whereby small-scale heterogeneity will be averaged using large base areas. For our experiments lysimeters with 2.5 m length, 2 m2 base area and with a wall thickness of the round vessel of 10 mm were used. A base frame weighted down by 120 t of concrete weights is necessary to press a lysimeter cylinder into the ground by the aid of a hydraulic press. The hydraulic press is connected with the base frame via chains. Because of the control of the four hydraulic cylinders a very precise vertical pressing process is guaranteed. To visualize the impact of the lysimeter filling on the intactness of the soil monolith a finite element computation was conducted. The finite element package ANSYS Release 11 was used to execute a nonlinear static analysis on a 2D-axisymmetric finite element model, to simulate the pressing process starting from a soil initial stress state and ending with the full length of the vessel driven into the soil, after which the hydraulic press and the concrete weights are deactivated and the vessel-surrounding soil is excavated. The numerical model of the pressing process considers among other things, a cap non-associative plasticity model with shear and volumetric hardening, soil to soil contact with cohesive zone modelling, soil to vessel contact with high friction, soil excavation using element birth

  4. Lysimeter experiments on the translocation of methabenzthiazuron and dissolved organic carbon in an orthic luvisol, construction of two climate measuring stations and investigations to validate the lysimeter system

    International Nuclear Information System (INIS)

    Puetz, T.

    1993-09-01

    To study the transfer of methabenzthiazuron into the soil solution and to investigate leaching in intensively cultivated orthic luvisol soil, 248 and 264 mg m -2 [phenyl-U- 14 C]methabenzthiazuron were applied to winter wheat in a w.p. 66.7% formulation by pre-emergence spraying in accordance with good agricultural practice on two lysimeters in November 1988. This corresponded to an application quantity of 3.7 and 4.0 kg ha -1 of Tribunil R . To study the translocation of dissolved organic carbon (DOC) in an orthic luvisol, 631 g m -2 14 C-labelled oat straw, corresponding to a practical application of 6-8 t ha -1 , was worked into the 0-5 cm of the soil of the third lysimeter in October 1988. After oat straw and methabenzthiazuron application, two suction candles were installed at each depth of 10, 20, 40 and 60 cm in two lysimeters for continuous soil solution sampling. (orig.)

  5. Ecotoxicity and fate of a silver nanomaterial in an outdoor lysimeter study.

    Science.gov (United States)

    Schlich, Karsten; Hoppe, Martin; Kraas, Marco; Fries, Elke; Hund-Rinke, Kerstin

    2017-08-01

    Sewage sludge is repeatedly applied as fertilizer on farmland due to its high nutrient content. This may lead to a significant increase of silver nanomaterials (AgNM) in soil over years. Therefore, our aim was to investigate the ecotoxicity and fate of AgNM under environmentally relevant conditions in outdoor lysimeters over 25 months. Two AgNM concentrations (1.7 and 8.0 mg/kg dry matter soil) were applied via sewage sludge into soil. In subsamples of the soil, incubated under laboratory conditions for 180 days, the comparability of outdoor and laboratory results regarding ecotoxicity was determined. The results from our long term lysimeter experiments show no detectable horizontal displacement in combination with very low remobilization to the percolate water. Thus, indicate that the sludge applied AgNM remains nearly immobile in the pathway between soils and leachate. However, Ag uptake to the roots of wheat and canola suggests that the chemical conditions in the rhizosphere induce AgNM remobilization from the incorporated sewage sludge even after two harvesting cycles. At the higher AgNM concentration a steady inhibition of the soil microflora was observed over 25 month in the lysimeter study, while there was no effect at the lower AgNM concentration. The results of the laboratory experiment reflect the findings of the lysimeter study and indicate that a risk assessment for AgNM based on data from laboratory tests is acceptable.

  6. Settlement behavior of municipal solid waste due to internal and external environmental factors in a lysimeter.

    Science.gov (United States)

    Melo, Márcio C; Caribé, Rômulo M; Ribeiro, Libânia S; Sousa, Raul B A; Monteiro, Veruschka E D; de Paiva, William

    2016-12-05

    Long-term settlement magnitude is influenced by changes in external and internal factors that control the microbiological activity in the landfill waste body. To improve the understanding of settlement phenomena, it is instructive to study lysimeters filled with MSW. This paper aims to understand the settlement behavior of MSW by correlating internal and external factors that influence waste biodegradation in a lysimeter. Thus, a lysimeter was built, instrumented and filled with MSW from the city of Campina Grande, the state of Paraíba, Brazil. Physicochemical analysis of the waste (from three levels of depth of the lysimeter) was carried out along with MSW settlement measurements. Statistical tools such as descriptive analysis and principal component analysis (PCA) were also performed. The settlement/compression, coefficient of variation and PCA results indicated the most intense rate of biodegradation in the top layer. The PCA results of intermediate and bottom levels presented fewer physicochemical and meteorological variables correlated with compression data in contrast with the top layer. It is possible to conclude that environmental conditions may influence internal indicators of MSW biodegradation, such as the settlement.

  7. Annual Report for Gravity Collection Lysimeter Monitoring Plan – ERDF Cells 5 and 6

    Energy Technology Data Exchange (ETDEWEB)

    M. L. Proctor

    2006-04-04

    The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date.

  8. Annual Report for Gravity Collection Lysimeter Monitoring Plan - ERDF Cells 5 and 6

    International Nuclear Information System (INIS)

    Remsen, W.E.

    2006-01-01

    The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date

  9. Annual Report for Gravity Collection Lysimeter Monitoring Plan - ERDF Cells 5 and 6

    International Nuclear Information System (INIS)

    Proctor, M.L.

    2006-01-01

    The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date.

  10. Lysimeter study to investigate the effect of rainfall patterns on leaching of isoproturon.

    Science.gov (United States)

    Beulke, Sabine; Brown, Colin D; Fryer, Christopher J; Walker, Allan

    2002-01-01

    The influence of five rainfall treatments on water and solute leaching through two contrasting soil types was investigated. Undisturbed lysimeters (diameter 0.25 m, length 0.5 m) from a sandy loam (Wick series) and a moderately structured clay loam (Hodnet series) received autumn applications of the radio-labelled pesticide isoproturon and bromide tracer. Target rainfall plus irrigation from the end of November 1997 to May 1998 ranged from drier to wetter than average (235 to 414 mm); monthly rainfall was varied according to a pre-selected pattern or kept constant (triplicate lysimeters per regime). Leachate was collected at intervals and concentrations of the solutes were determined. Total flow (0.27-0.94 pore volumes) and losses of bromide (3-80% of applied) increased with increasing inputs of water and were larger from the Wick sandy loam than from the Hodnet clay loam soil. Matrix flow appeared to be the main mechanism for transport of isoproturon through the Wick soil whereas there was a greater influence of preferential flow for the Hodnet lysimeters. The total leached load of isoproturon from the Wick lysimeters was 0.02-0.26% of that applied. There was no clear variation in transport processes between the rainfall treatments investigated for this soil and there was an approximately linear relationship (r2 = 0.81) between leached load and total flow. Losses of isoproturon from the Hodnet soil were 0.03-0.39% of applied and there was evidence of enhanced preferential flow in the driest and wettest treatments. Leaching of isoproturon was best described by an exponential relationship between load and total flow (r2 = 0.62). A 45% increase in flow between the two wettest treatments gave a 100% increase in leaching of isoproturon from the Wick soil. For the Hodnet lysimeters, a 35% increase in flow between the same treatments increased herbicide loss by 325%.

  11. Leaching of human pathogens in repacked soil lysimeters and contamination of potato tubers under subsurface drip irrigation in Denmark

    DEFF Research Database (Denmark)

    Forslund, Anita; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    The risk for contamination of potatoes and groundwater through subsurface drip irrigation with low quality water was explored in 30 large-scale lysimeters containing repacked coarse sand and sandy loam soils. The human pathogens, Salmonella Senftenberg, Campylobacter jejuni and Escherichia coli O......, phage 28B was detected in low concentrations (2 pfu ml1) in leachate from both sandy loam soil and coarse sand lysimeters. After 27 days, phage 28B continued to be present in similar concentrations in leachate from lysimeters containing coarse sand, while no phage were found in lysimeters with sandy....... The findings of bacterial pathogens and phage 28 on all potato samples suggest that the main risk associated with subsurface drip irrigation with low quality water is faecal contamination of root crops, in particular those consumed raw....

  12. Design and construction of a large weighing lysimeter in an almond orchard

    Energy Technology Data Exchange (ETDEWEB)

    Lorite, I. J.; Santos, C.; Testi, L.; Fereres, E.

    2012-11-01

    Effective water management is essential to ensure the sustainability of irrigated agriculture. The accurate determination of crop water requirements is the first step in this task. This paper describes the building of a one-tree weighing lysimeter (3 × 3 m and 2.15 m depth) located in an almond (Prunus dulcis cv. Guara) orchard, inside the experimental farm “Alameda del Obispo” in Córdoba, Spain, to measure orchard evapotranspiration (ETc). Following a review on lysimetry, the description of the construction of the weighing lysimeter is provided in detail, including considerations relative to system resolution and wind effects on the measurements. Finally, some preliminary results of the evaporation and transpiration of young almond trees are presented demonstrating that lysimetry in orchards provides accurate ETc values needed to determine irrigation water requirements. (Author) 72 refs.

  13. Automated Passive Capillary Lysimeters for Estimating Water Drainage in the Vadose Zone

    Science.gov (United States)

    Jabro, J.; Evans, R.

    2009-04-01

    In this study, we demonstrated and evaluated the performance and accuracy of an automated PCAP lysimeters that we designed for in-situ continuous measuring and estimating of drainage water below the rootzone of a sugarbeet-potato-barley rotation under two irrigation frequencies. Twelve automated PCAPs with sampling surface dimensions of 31 cm width * 91 cm long and 87 cm in height were placed 90 cm below the soil surface in a Lihen sandy loam. Our state-of-the-art design incorporated Bluetooth wireless technology to enable an automated datalogger to transmit drainage water data simultaneously every 15 minutes to a remote host and had a greater efficiency than other types of lysimeters. It also offered a significantly larger coverage area (2700 cm2) than similarly designed vadose zone lysimeters. The cumulative manually extracted drainage water was compared with the cumulative volume of drainage water recorded by the datalogger from the tipping bucket using several statistical methods. Our results indicated that our automated PCAPs are accurate and provided convenient means for estimating water drainage in the vadose zone without the need for costly and manually time-consuming supportive systems.

  14. Transport and modeling of estrogenic hormones in a dairy farm effluent through undisturbed soil lysimeters.

    Science.gov (United States)

    Steiner, Laure D; Bidwell, Vincent J; Di, Hong J; Cameron, Keith C; Northcott, Grant L

    2010-04-01

    The presence of endocrine-disrupting chemicals, including estrone (E1) and 17beta-estradiol (E2), in surface waters has been associated with physiological dysfunction in a number of aquatic organisms. One source of surface and groundwater contamination with E1 and E2 is the land application of animal wastes. The processes involved in the transport of these hormones in the soil, when applied with animal wastes, are still unclear. Therefore, a field-transport experiment was carried out, where a dairy farm effluent spiked with E1 and E2 was applied on large (50 cm diameter and 70 cm depth) undisturbed soil lysimeters. The concentrations of E1 and E2 in the leachate were monitored over a 3-month period, during which irrigation was applied. The experimental data suggest that E1 and E2 were transported through preferential/macropore flow pathways. The data from the experiment also show that E1 and E2 are leached earlier than the inert tracer (bromide). This observation can be explained either by the presence of antecedent concentrations in the soil or by an enhanced transport of E1 and E2 through the soil. A state-space mixing-cell model was further developed in order to describe the transport of E1 and E2 by three transport processes in parallel. The inverse modeling of the leaching data did not support the hypothesis that antecedent concentrations of estrogens could be responsible for the observed breakthrough curves but confirmed that estrogens were transported mainly via preferential/macropore flow and also via an enhanced transport. The parameter values that characterized this enhanced transport strongly suggest that this enhanced transport is mediated by colloids. For the first time, the simultaneous transport of E1 and E2 was modeled under transient conditions, taking into account the advection-dispersion, preferential/macropore flow, and colloidal-enhanced transport processes as well as E1 and E2 dissipation in the soil. These findings have major implications in

  15. Fluxes of N2O and CH4 from forest and grassland lysimeter soils in response to simulated climate change

    Science.gov (United States)

    Weymann, Daniel; Brueggemann, Nicolas; Puetz, Thomas; Vereecken, Harry

    2015-04-01

    Central Europe is expected to be exposed to altered temperature and hydrological conditions, which will affect the vulnerability of nitrogen and carbon cycling in soils and thus production and fluxes of climate relevant trace gases. However, knowledge of the response of greenhouse gas fluxes to climate change is limited so far, but will be an important basis for future climate projections. Here we present preliminary results of an ongoing lysimeter field study which aims to assess the impact of simulated climate change on N2O and CH4 fluxes from a forest and a fertilized grassland soil. The lysimeters are part of the Germany-wide research infrastructure TERENO, which investigates feedbacks of climate change to the pedosphere on a long-term scale. Lysimeters (A = 1m2) were established in 2010 at high elevated sites (HE, 500 and 600 m.a.s.l.) and subsequently transferred along an altitudinal gradient to a low elevated site (LE, 100 m.a.s.l.) within the Eifel / Lower Rhine Valley Observatory in Western Germany, thereby resulting in a temperature increase of 2.3 K whereas precipitation decreased by 160 mm during the present study period. Systematic monitoring of soil-atmosphere exchange of N2O and CH4 based on weekly manual closed chamber measurements at HE and LE sites has started in August 2013. Furthermore, we routinely determine dissolved N2O and CH4 concentrations in the seepage water using a headspace equilibration technique and record water discharge in order to quantify leaching losses of both greenhouse gases. Cumulative N2O fluxes clearly responded to simulated climate change conditions and increased by 250 % and 600 % for the forest and the grassland soil, respectively. This difference between the HE and LE sites was mainly caused by an exceptionally heavy precipitation event in July 2014 which turned the LE site sustainably to a consistently higher emission level. Nonetheless, emissions remained rather small and ranged between 20 and 40 μg m-2 h-1. In

  16. Lisímetro de pesagem de grande porte.: desenvolvimento e calibração A large-scale weighting lysimeter. part I: development and calibration

    Directory of Open Access Journals (Sweden)

    Luiz F. M. de S. Campeche

    2011-05-01

    Full Text Available A evapotranspiração de plantas frutíferas foi medida a partir da instalação e calibração de um lisímetro de pesagem de grande porte. O equipamento, composto por caçamba metálica em aço carbono, possui arquitetura circular com área de 5,72 m² e massa total de 10,5 toneladas. Uma muda de coqueiro anão-verde foi transplantada para o lisímetro e mantida sob as mesmas condições de solo e adubação do campo experimental. Na automação do processo foi utilizado o mecanismo de alívio de carga baseado em sistemas de alavancas e contrapesos, apoiado em uma célula de carga com capacidade de 200 kg e precisão de 0,02% de sua capacidade. Os dados de saída da célula de carga foram armazenados em um coletor automático de dados tipo data logger. A relação entre a variação de massa e a voltagem da célula de carga do lisímetro é descrita adequadamente por modelo linear com mínima histerese. A metodologia empregada na instalação e na calibração do lisímetro foi adequada, obtendo-se um coeficiente de determinação de 0,99 na equação de calibração. Os resultados ainda indicam que o lisímetro de pesagem pode ser utilizado com êxito na determinação de evapotranspiração de plantas frutíferas de grande porte.The objectives of present study were to develop and to calibrate a large-scale weighing lysimeter in order to estimate evapotranspiration of fruit plants. The equipment consisted of a metallic bucket (steel carbon of circular design with total area of 5.72 m² and total mass of 10.5 t. A seedling of dwarf-green coconut palm was transplanted in lysimeter and maintained under same fertilization conditions of experimental field. For automation of the process, a mechanism of load relief based on systems of levers and counterbalances was used, leaning in a load cell with capacity of 200 kg and precision of 0.02% of its capacity. The output data of load cell were stored in an automatic data acquisition system. The

  17. Nitrate Leaching from Winter Cereal Cover Crops Using Undisturbed Soil-Column Lysimeters.

    Science.gov (United States)

    Meisinger, John J; Ricigliano, Kristin A

    2017-05-01

    Cover crops are important management practices for reducing nitrogen (N) leaching, especially in the Chesapeake Bay watershed, which is under total maximum daily load (TMDL) restraints. Winter cereals are common cool-season crops in the Bay watershed, but studies have not directly compared nitrate-N (NO-N) leaching losses from these species. A 3-yr cover crop lysimeter study was conducted in Beltsville, MD, to directly compare NO-N leaching from a commonly grown cultivar of barley ( L.), rye ( L.), and wheat ( L.), along with a no-cover control, using eight tension-drained undisturbed soil column lysimeters in a completely randomized design with two replicates. The lysimeters were configured to exclude runoff and to estimate NO-N leaching and flow-weighted NO-N concentration (FWNC). The temporal pattern of NO-N leaching showed a consistent highly significant ( leaching with cover crops compared with no cover but showed only small and periodically significant ( leaching was more affected by the quantity of establishment-season (mid-October to mid-December) precipitation than by cover crop species. For example, compared with no cover, winter cereal covers reduced NO-N leaching 95% in a dry year and 50% in wet years, with corresponding reductions in FWNC of 92 and 43%, respectively. These results are important for scientists, nutrient managers, and policymakers because they directly compare NO-N leaching from winter cereal covers and expand knowledge for developing management practices for winter cereals that can improve water quality and increase N efficiency in cropping systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Flow through in situ reactors with suction lysimeter sampling capability and methods of using

    Science.gov (United States)

    Radtke, Corey W [Idaho Falls, ID; Blackwelder, D Brad [Blackfoot, ID; Hubbell, Joel M [Idaho Falls, ID

    2009-11-17

    An in situ reactor for use in a geological strata includes a liner defining a centrally disposed passageway and a sampling conduit received within the passageway. The sampling conduit may be used to receive a geological speciment derived from geological strata therein and a lysimeter is disposed within the sampling conduit in communication with the geological specimen. Fluid may be added to the geological specimen through the passageway defined by the liner, between an inside surface of the liner and an outside surface of the sampling conduit. A distal portion of the sampling conduit may be in fluid communication with the passageway.

  19. Mineralization and Transfer Processes of 14C-labeled Pesticides in Outdoor Lysimeters

    International Nuclear Information System (INIS)

    Grundmann, Sabine; Doerfler, Ulrike; Ruth, Bernhard; Loos, Christine; Wagner, Tobias; Karl, Heidrun; Munch, Jean Charles; Schroll, Reiner

    2008-01-01

    A recently designed two-chamber-lysimeter-test-system allows the detailed investigation of degradation, transport and transfer processes of 14 C-labeled substances in soil-plant-atmosphere-systems under outdoor conditions. With this test system it is feasible to distinguish between 14 C-emissions from soil surfaces and 14 C-emissions from plant surfaces in soil monoliths under real environmental conditions. Special soil humidity sensors allow the measurement of soil water content near to the soil surface, in 1 and 5 cm depth. The behavior of organic chemicals can be followed for a whole vegetation period and a mass balance for the applied chemical can be established. Some selected results of the herbicides isoproturon and glyphosate - using the two-chamber-lysimeter-test-system - are presented to demonstrate its applicability for the identification and quantification of the processes that govern pesticide behavior in soil-plant-systems. Mineralization of 14 C-isoproturon was very different in four different soils; the mineralization capacity of the soils ranged from 2 to 60%. Leaching of isoproturon in general was very low, but depending on the soil type and environmental conditions isoproturon and its metabolites could be leached via preferential flow, especially shortly after application. For the herbicide 14 C-glyphosate no accumulation of residues in the soil and no leaching of the residues to deeper soil layers could be observed after three applications. Glyphosate was rapidly degraded to AMPA in the soil. Glyphosate and AMPA were accumulated in soy bean nodules

  20. Leaching of 60Co, 137Cs and 226Ra in lysimeter experiments

    International Nuclear Information System (INIS)

    Gerzabek, M.H.; Mueck, K.; Steger, F.; Algader, S.M.

    1996-10-01

    The present report describes the first results obtained from lysimeter experiments started in 1990. The lysimeter plant consists of twelve soil monoliths from four different sites (three replicates each). Since 1990 the following agricultural crops were grown: endive, corn, winter wheat, mustard, sugar beet and potato. Gravitational water ranged from 3.9 % to 18.3 % of precipitation plus irrigation water, calculated as half years average values excluding the first six months of operation. The two Cambisols on sediments exhibited a mean percentage of approx. 10 %. The Dystric Cambisol on silicate rock and the Gleysol showed average values of 20 %. In 1990 the top layers (20 cm) were contaminated with three radionuclides. The leaching of the contaminants 60 Co, 137 Cs and 226 Ra differed distinctly between the elements. The lowest leaching rates were observed for 137 Cs, followed by 60 Co. The 226 Ra-concentrations in the gravitational water were clearly highest of all. However, the comparison of the 226 Ra/ 22 2 8 Ra ratios in deep soil layers and in gravitational water showed that the 226 Ra measured in the leachate originates from the natural contents in the subsoil and not from the artificial 226 Ra contamination of the topsoil. The mobility of the artificial radionuclides decreased therefore in the following order: 60 Co > ( 226 Ra) > 137 Cs. (author)

  1. LYSIMETER - A UNIQUE TOOL FOR MONITORING THE INTERACTIONS AMONG THE COMPONENTS OF ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivan Matušek

    2016-06-01

    Full Text Available Modern lysimeter facilities in connection with meteorological stations allow monitoring and evaluation of mutual basic components of the environment, such as water, air, soil and vegetation. Water is the most important component of the ecosystem and the component which connects all the other components. Therefore, we need to know the basic distribution and water balance in the different components of the environment to be able to interpret some processes in nature. Rainfall, which is the primary source of vital processes in the soil, is formed in the air. The amount of precipitation that gets into the soil and into the groundwater is affected by weather conditions. Primary distribution of rainwater is divided between infiltration, surface runoff, transpiration and evapotranspiration. The amount of water infiltrated into the soil and then evaporated by solar activity or activities of plants can be identified primarily by monitoring changes in weight. For this monitoring we use weighable lysimeter. This equipment with the monolith size of surface area 1 m2 and the depth of 1.5 m is able to follow online updates of weight of the 2 ton body with an accuracy of 100 g. When we add to quantification of leakages through the bottom layer, we obtain a comprehensive record of rainfall at the time in the natural environment of the individual components. The obtained data can be further interpreted in terms of the needs of hydrology, agriculture, and environmental studies, and according to the purpose and objectives for which we want to use them.

  2. Numerical simulation of water flow in lysimeters; Numerische Simulation des Wasserflusses in Lysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Honisch, M.; Klotz, D. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie

    1999-02-01

    A small-scale lysimeter plant on the premises of GSF has been dedicated to the study of water movement in sediments of Quaternary and Tertiary origin. The purpose of the present study was to describe water transport and non-reactive transport in the lysimeters under transient conditions and test the suitability of the numerical simulation programme Hydrus-2D for the unsaturated zone. The hydraulic characteristics and dispersiveness parameters were derived from earlier studies. The validity of these values was determined on the basis of a tracer experiment using the ideal tracer tritium water. [Deutsch] Zur Charakterisierung der Wasserbewegung in Sedimenten quartaeren und tertiaeren Ursprungs wird auf dem Gelaende der GSF eine Kleinlysimeteranlage betrieben. Ziel der vorliegenden Untersuchung war es, den Wasserfluss und nicht-reaktiven Transport in den Saeulen unter transienten Bedingungen zu beschreiben und hierbei die Eignung des numerischen Simulationsprogramms Hydrus-2D fuer die ungesaettigte Zone zu ueberpruefen. Die hydraulischen Kenngroessen und Dispersivitaetsparameter waren aus frueheren Untersuchungen abzuleiten. Die offene Frage hinsichtlich der Validitaet dieser Werte sollte auf der Grundlage eines Tracerexperiments mit tritiiertem Wasser als idealem Tracer ueberprueft werden. (orig.)

  3. Soil-plant transfer of Cs-137 and Sr-90 in digestate amended agricultural soils- a lysimeter scale experiment

    Science.gov (United States)

    Mehmood, Khalid; Berns, Anne E.; Pütz, Thomas; Burauel, Peter; Vereecken, Harry; Zoriy, Myroslav; Flucht, Reinhold; Opitz, Thorsten; Hofmann, Diana

    2014-05-01

    Radiocesium and radiostrontium are among the most problematic soil contaminants following nuclear fallout due to their long half-lives and high fission yields. Their chemical resemblance to potassium, ammonium and calcium facilitates their plant uptake and thus enhances their chance to reach humans through the food-chain dramatically. The plant uptake of both radionuclides is affected by the type of soil, the amount of organic matter and the concentration of competitive ions. In the present lysimeter scale experiment, soil-plant transfer of Cs-137 and Sr-90 was investigated in an agricultural silty soil amended with digestate, a residue from a biogas plant. The liquid fraction of the digestate, liquor, was used to have higher nutrient competition. Digestate application was done in accordance with the field practice with an application rate of 34 Mg/ha and mixing it in top 5 cm soil, yielding a final concentration of 38 g digestate/Kg soil. The top 5 cm soil of the non-amended reference soil was also submitted to the same mixing procedure to account for the physical disturbance of the top soil layer. Six months after the amendment of the soil, the soil contamination was done with water-soluble chloride salts of both radionuclides, resulting in a contamination density of 66 MBq/m2 for Cs-137 and 18 MBq/m2 for Sr-90 in separate experiments. Our results show that digestate application led to a detectable difference in soil-plant transfer of the investigated radionuclides, effect was more pronounced for Cs-137. A clear difference was observed in plant uptake of different plants. Pest plants displayed higher uptake of both radionuclides compared to wheat. Furthermore, lower activity values were recorded in ears compared to stems for both radionuclides.

  4. A Comparison of delO18 Composition of Water Extracted from Suction Lysimeters, Centrifugation, and Azeotropic Distillation

    Science.gov (United States)

    Figueroa, A.; Tindall, J. A.; Friedel, M. J.

    2005-12-01

    Concentration of delO18 in water samples extracted by suction lysimeters is compared to samples obtained by methods of centrifugation and azeotropic distillation. Intact soil cores (30 cm diameter by 40 cm height) were extracted from two different sites. Site 1 was rapid infiltration basin number 50, near Altamonte Springs in Seminole County, Florida on properties belonging to the Walt Disney World Resort Complex. Site 2 was the Missouri Management System Evaluation Area (MSEA) near Centralia in Boone County, Missouri. The delO18 water was analyzed on a mass spectrophotometer. Potassium Bromide (KBr) was also used as a tracer and analyzed by ion chromatography. A portion of the data obtained was modeled using CXTFIT. Water collected by centrifugation and azeotropic distillation data were about 2-5% more negative than that collected by suction lysimeter values from the Florida (sandy) soil and about 5-7 % more negative from the Missouri (well structured clay) soil. Results indicate that the majority of soil water in well structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. Also, it is plausible that evaporation caused some delO18 enrichment in the suction lysimeters. Suction lysimeters preferentially sampled water held at lower matric potentials, which may not represent total soil water. In cases where a sufficient volume of water has passed through the soil profile and displaced all previous pore water, suction lysimeters will however collect a representative sample of all the water at that depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeters be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The CXTFIT program worked well for Florida soils (a more homogeneous sand), but gave poor performance for Missouri soils (well structured clays) except for deeper depths where clay structure was less

  5. Status report for the Small-Tube Lysimeter Facility; Fiscal year 1992

    International Nuclear Information System (INIS)

    Sackschewsky, M.R.; Kemp, C.J.; Cadwell, L.L.

    1993-07-01

    Westinghouse Hanford Company and Pacific Northwest Laboratory are jointly developing earthen protective barriers for the near-surface disposal of radioactive and hazardous waste at the Hanford Site. The proposed barrier design consists of a blanket of fine-textured soil overlying a sequence of layers, varying from sand to basalt riprap. The experiments conducted at the Small-Tube Lysimeter Facility (STLF) were designed to measure the influence of erosion-control practices and alternate barrier layer configurations on water movement within the barrier, and extraction of water from the barrier. This report describes the results of data collected during the period from September 1988 through May 1992 at the STLF. Four concurrent experiments are being performed at this facility, each of these experiments are designed to test different components of the proposed barrier. The experiments are as follows

  6. Geochemical Results of Lysimeter Sampling at the Manning Canyon Repository in the Mercur Mining District, Utah

    Science.gov (United States)

    Earle, John; Choate, LaDonna

    2010-01-01

    This report presents chemical characteristics of transient unsaturated-zone water collected by lysimeter from the Manning Canyon repository site in Utah. Data collected by U.S. Geological Survey and U.S. Department of the Interior, Bureau of Land Management scientists under an intragovernmental order comprise the existing body of hydrochemical information on unsaturated-zone conditions at the site and represent the first effort to characterize the chemistry of the soil pore water surrounding the repository. Analyzed samples showed elevated levels of arsenic, barium, chromium, and strontium, which are typical of acidic mine drainage. The range of major-ion concentrations generally showed expected soil values. Although subsequent sampling is necessary to determine long-term effects of the repository, current results provide initial data concerning reactive processes of precipitation on the mine tailings and waste rock stored at the site and provide information on the effectiveness of reclamation operations at the Manning Canyon repository.

  7. Investigations of pollutant migration using lysimeters; Untersuchungen zur Schadstoff-Migration in Lysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, D. (ed.)

    2002-07-01

    The third GSF Lysimeter Workshop focused on pollutant migration in underground strata, i.e. the dispersion of water constituents as referred to water transport on the basis of ideal tracer investigations. [German] Der am 29./30.04.2002 stattgefundene Workshop 'Untersuchungen zur Schadstoffmigration in Lysimetern' war der dritte GSF-Lysimeterworkshop nach denen in den Jahren 1998 und 2000 veranstalteten. Nachdem in den Jahren 1998 und 2000 der Wassertransport und die Bestimmung der Sickerwassergeschwindigkeit in Lysimetern im Mittelpunkt standen, war 2002 die Schadstoffmigration im Untergrund der Schwerpunkt der Vortraege und Poster. Unter Migration wird das Ausbreitungsverhalten von Wasserinhalts-(Fremd-, Schad-)Stoffen bezogen auf den Wassertransport, bestimmt mit idealen Tracern, verstanden. (orig.)

  8. Mineralization and Transfer Processes of {sup 14}C-labeled Pesticides in Outdoor Lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Grundmann, Sabine; Doerfler, Ulrike, E-mail: doerfler@gsf.de; Ruth, Bernhard; Loos, Christine [GSF - National Research Center for Environment and Health, Institute of Soil Ecology (Germany); Wagner, Tobias [GSF - National Research Center for Environment and Health, Institute of Biochemical Plant Pathology (Germany); Karl, Heidrun; Munch, Jean Charles; Schroll, Reiner [GSF - National Research Center for Environment and Health, Institute of Soil Ecology (Germany)

    2008-04-15

    A recently designed two-chamber-lysimeter-test-system allows the detailed investigation of degradation, transport and transfer processes of {sup 14}C-labeled substances in soil-plant-atmosphere-systems under outdoor conditions. With this test system it is feasible to distinguish between {sup 14}C-emissions from soil surfaces and {sup 14}C-emissions from plant surfaces in soil monoliths under real environmental conditions. Special soil humidity sensors allow the measurement of soil water content near to the soil surface, in 1 and 5 cm depth. The behavior of organic chemicals can be followed for a whole vegetation period and a mass balance for the applied chemical can be established. Some selected results of the herbicides isoproturon and glyphosate - using the two-chamber-lysimeter-test-system - are presented to demonstrate its applicability for the identification and quantification of the processes that govern pesticide behavior in soil-plant-systems. Mineralization of {sup 14}C-isoproturon was very different in four different soils; the mineralization capacity of the soils ranged from 2 to 60%. Leaching of isoproturon in general was very low, but depending on the soil type and environmental conditions isoproturon and its metabolites could be leached via preferential flow, especially shortly after application. For the herbicide {sup 14}C-glyphosate no accumulation of residues in the soil and no leaching of the residues to deeper soil layers could be observed after three applications. Glyphosate was rapidly degraded to AMPA in the soil. Glyphosate and AMPA were accumulated in soy bean nodules.

  9. Multitracer studies for determining seepage water and anion movement in four types of soil using lysimeters with different functions and designs

    International Nuclear Information System (INIS)

    Knappe, S.; Russow, R.

    1999-01-01

    Lysimeter experiments based on the stable isotope tracer technique are a suitable means of examining the complex relationships governing water and material transport processes in the soil. The present paper reports on experiments in which water and nitrate movement was traced directly by means of lysimeters placed at different depths and using deuterium water and [ 15 N]N-nitrate for pulse marking. Extensive investigations carried out during the dissection of soil monoliths that had been used for many years in lysimeters offered an opportunity for stable isotope tracer studies aimed at determining seepage water and anion movement in undisturbed soils and, after dismantling the lysimeters, conducting soil analyses to find out more about the fate of nonpercolated tracers at various soil depths. Following other authors, bromide anions were additionally used as conservative tracers [de

  10. Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters

    Science.gov (United States)

    2009-12-01

    ER D C TR -0 9- 10 Strategic Environmental Research and Development Program Phytoremediation of Composition-B Derived TNT and RDX in...Program ERDC TR-09-10 December 2009 Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters Elly P. H...for U.S. Army Corps of Engineers Washington, DC 20314-1000 ERDC TR-09-10 ii Abstract: This report describes a study in which phytoremediation of

  11. EPICOR-II: a field leaching test of solidified radioactively loaded ion exchange resin

    International Nuclear Information System (INIS)

    Davis, E.C.; Marshall, D.S.; Todd, R.A.; Craig, P.M.

    1986-08-01

    As part of an ongoing research program investigating the disposal of radioactive solid wastes in the environment' the Oak Ridge National Laboratory (ORNL) is participating with Argonne National Laboratory, the Idaho National Engineering Laboratory, and the Nuclear Regulatory Commission in a study of the leachability of solidified EPICOR-II ion-exchange resin under simulated disposal conditions. To simulate disposal, a group of five 2-m 3 soil lysimeters has been installed in Solid Waste Storage Area Six at ORNL, with each lysimeter containing a small sample of solidified resin at its center. Two solidification techniques are being investigated: a Portland cement and a vinyl ester-styrene treatment. During construction, soil moisture temperature cells were placed in each lysimeter, along with five porous ceramic tubes for sampling water near the waste source. A meteorological station was set up at the study site to monitor climatic conditions (primarily precipitation and air temperature), and a data acquisition system was installed to keep daily records of these meteorological parameters as well as lysimeter soil moisture and temperature conditions. This report documents the first year of the long-term field study and includes discussions of lysimeter installation, calibration of soil moisture probes, installation of the site meteorological station, and the results of the first-quarter sampling for radionuclides in lysimeter leachate. In addition, the data collection and processing system developed for this study is documented, and the results of the first three months of data collection are summarized in Appendix D

  12. Lysimeter study with a cambric arenosol exposed to artificial acid rain: I. Concentrations of ions in leachate

    International Nuclear Information System (INIS)

    Sogn, T.A.; Abrahamsen, G.; Stuanes, A.O.

    1993-01-01

    The effects of artificial acid rain on soil leachate composition were studied in a lysimeter experiment. Cambic Arenosol (Typic Udipsamment) in monolith lysimeters was treated for 6 1/2 year with 125 mm yr -1 artificial rain in addition to natural precipitation. Artificial acid rain was produced from groundwater with H 2 SO 4 added. pH levels of 6.1, 4 and 3 were used. Increasing content of H 2 SO 4 in the artificial rain increased the concentration of Ca 2+ and Mg 2+ in the leachate significantly. The pH of the leachate was slightly reduced only by the most acidic treatment (pH 3). The H + retention was not accompanied by a proportionate increase in the Al ion concentration. A slight increase in the Al ion concentration was only observed in the leachate from the pH 3-treated lysimeter. It is concluded that cation exchange and/or weathering were the main buffer mechanisms in the soil. The study supports conclusions from other acidification studies, that acidic precipitation is likely to increase the leaching of Ca 2+ and Mg 2+ from soils. 25 refs., 3 figs., 7 tabs

  13. Comparison of lysimeter based and calculated ASCE reference evapotranspiration in a subhumid climate

    Science.gov (United States)

    Nolz, Reinhard; Cepuder, Peter; Eitzinger, Josef

    2016-04-01

    The standardized form of the well-known FAO Penman-Monteith equation, published by the Environmental and Water Resources Institute of the American Society of Civil Engineers (ASCE-EWRI), is recommended as a standard procedure for calculating reference evapotranspiration (ET ref) and subsequently plant water requirements. Applied and validated under different climatic conditions it generally achieved good results compared to other methods. However, several studies documented deviations between measured and calculated reference evapotranspiration depending on environmental and weather conditions. Therefore, it seems generally advisable to evaluate the model under local environmental conditions. In this study, reference evapotranspiration was determined at a subhumid site in northeastern Austria from 2005 to 2010 using a large weighing lysimeter (ET lys). The measured data were compared with ET ref calculations. Daily values differed slightly during a year, at which ET ref was generally overestimated at small values, whereas it was rather underestimated when ET was large, which is supported also by other studies. In our case, advection of sensible heat proved to have an impact, but it could not explain the differences exclusively. Obviously, there were also other influences, such as seasonal varying surface resistance or albedo. Generally, the ASCE-EWRI equation for daily time steps performed best at average weather conditions. The outcomes should help to correctly interpret ET ref data in the region and in similar environments and improve knowledge on the dynamics of influencing factors causing deviations.

  14. A comparative modeling study of a dual tracer experiment in a large lysimeter under atmospheric conditions

    Science.gov (United States)

    Stumpp, C.; Nützmann, G.; Maciejewski, S.; Maloszewski, P.

    2009-09-01

    SummaryIn this paper, five model approaches with different physical and mathematical concepts varying in their model complexity and requirements were applied to identify the transport processes in the unsaturated zone. The applicability of these model approaches were compared and evaluated investigating two tracer breakthrough curves (bromide, deuterium) in a cropped, free-draining lysimeter experiment under natural atmospheric boundary conditions. The data set consisted of time series of water balance, depth resolved water contents, pressure heads and resident concentrations measured during 800 days. The tracer transport parameters were determined using a simple stochastic (stream tube model), three lumped parameter (constant water content model, multi-flow dispersion model, variable flow dispersion model) and a transient model approach. All of them were able to fit the tracer breakthrough curves. The identified transport parameters of each model approach were compared. Despite the differing physical and mathematical concepts the resulting parameters (mean water contents, mean water flux, dispersivities) of the five model approaches were all in the same range. The results indicate that the flow processes are also describable assuming steady state conditions. Homogeneous matrix flow is dominant and a small pore volume with enhanced flow velocities near saturation was identified with variable saturation flow and transport approach. The multi-flow dispersion model also identified preferential flow and additionally suggested a third less mobile flow component. Due to high fitting accuracy and parameter similarity all model approaches indicated reliable results.

  15. Evaluation of evapotranspiration on paddy rice using non-weighting lysimeters under the different air temperature

    Science.gov (United States)

    Oh, D.; Ryu, J. H.; Cho, J.

    2017-12-01

    Estimation of the crop evapotranspiration (ETc), as a representative of crop water needs, is important for not only high crop productivity, but also improving irrigation water management. In farm lands crop coefficient (Kc), the ratio of ETc to potential ET, is often used to simply estiamte ETc. However, the traits of Kc under the global warming condition will different with current one because plant transpiration and surface evaporaiton will be changed by the alternative crop growth and evaporative energy. In this study, Non-Weighting Lysimeter (NWL) was used to directly estimate ETc under the warmed condition, particularly for paddy riace which has one of lower water use efficiency. The different air t emperature (Ta) conditions for the NWL were provided by Temperature Gradient Chamber (TGC), which was formed gradually warmed conditions. The water body evporation and paddy rice evapotransipiration in the NWL were at the two places of ambient Ta (AT) and AT+3° in the TGC. In addition, we installed Infra-Red thermometer (IRT) to understand the surface energy balance. The result was shown that the different partitioning of evaporation and transpiration of paddy rice at the AT+3°, comparing at AT. Further, the water use efficiency, the ratio of yield to total ET, was also decreased in the warmed condition. These experiments for paddy rice ET in the warmed conditions during growth period will be useful to understand the effect of global warming on the hydrological cycle and manamge the irrigation schedule for more efficient water use.

  16. Probabilistic risk assessment of nitrate groundwater contamination from greenhouses in Albenga plain (Liguria, Italy) using lysimeters.

    Science.gov (United States)

    Paladino, Ombretta; Seyedsalehi, Mahdi; Massabò, Marco

    2018-04-05

    The use of fertilizers in greenhouse-grown crops can pose a threat to groundwater quality and, consequently, to human beings and subterranean ecosystem, where intensive farming produces pollutants leaching. Albenga plain (Liguria, Italy) is an alluvial area of about 45km 2 historically devoted to farming. Recently the crops have evolved to greenhouses horticulture and floriculture production. In the area high levels of nitrates in groundwater have been detected. Lysimeters with three types of reconstituted soils (loamy sand, sandy clay loam and sandy loam) collected from different areas of Albenga plain were used in this study to evaluate the leaching loss of nitrate (NO 3 - ) over a period of 12weeks. Leaf lettuce (Lactuca sativa L.) was selected as a representative green-grown crop. Each of the soil samples was treated with a slow release fertilizer, simulating the real fertilizing strategy of the tillage. In order to estimate the potential risk for aquifers as well as for organisms exposed via pore water, nitrate concentrations in groundwater were evaluated by applying a simplified attenuation model to the experimental data. Results were refined and extended from comparison of single effects and exposure values (Tier I level) up to the evaluation of probabilistic distributions of exposure and related effects (Tier II, III IV levels). HHRA suggested HI >1 and about 20% probability of exceeding RfD for all the greenhouses, regardless of the soil. ERA suggested HQ>100 for all the greenhouses; 93% probability of PNEC exceedance for greenhouses containing sand clay loam. The probability of exceeding LC50 for 5% of the species was about 40% and the probability corresponding to DBQ of DEC/EC50>0.001 was >90% for all the greenhouses. The significantly high risk, related to the detected nitrate leaching loss, can be attributed to excessive and inappropriate fertigation strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. A Particle Smoother with Sequential Importance Resampling for soil hydraulic parameter estimation: A lysimeter experiment

    Science.gov (United States)

    Montzka, Carsten; Hendricks Franssen, Harrie-Jan; Moradkhani, Hamid; Pütz, Thomas; Han, Xujun; Vereecken, Harry

    2013-04-01

    An adequate description of soil hydraulic properties is essential for a good performance of hydrological forecasts. So far, several studies showed that data assimilation could reduce the parameter uncertainty by considering soil moisture observations. However, these observations and also the model forcings were recorded with a specific measurement error. It seems a logical step to base state updating and parameter estimation on observations made at multiple time steps, in order to reduce the influence of outliers at single time steps given measurement errors and unknown model forcings. Such outliers could result in erroneous state estimation as well as inadequate parameters. This has been one of the reasons to use a smoothing technique as implemented for Bayesian data assimilation methods such as the Ensemble Kalman Filter (i.e. Ensemble Kalman Smoother). Recently, an ensemble-based smoother has been developed for state update with a SIR particle filter. However, this method has not been used for dual state-parameter estimation. In this contribution we present a Particle Smoother with sequentially smoothing of particle weights for state and parameter resampling within a time window as opposed to the single time step data assimilation used in filtering techniques. This can be seen as an intermediate variant between a parameter estimation technique using global optimization with estimation of single parameter sets valid for the whole period, and sequential Monte Carlo techniques with estimation of parameter sets evolving from one time step to another. The aims are i) to improve the forecast of evaporation and groundwater recharge by estimating hydraulic parameters, and ii) to reduce the impact of single erroneous model inputs/observations by a smoothing method. In order to validate the performance of the proposed method in a real world application, the experiment is conducted in a lysimeter environment.

  18. Zero-tension lysimeters: An improved design to monitor colloid-facilitated contaminant transport in the vadose zone

    International Nuclear Information System (INIS)

    Thompson, M.L.; Scharf, R.L.; Shang, C.

    1995-01-01

    There is increasing evidence that mobile colloids facilitate the long-distance transport of contaminants. The mobility of fine particles and macromolecules has been linked to the movement of actinides, organic contaminants, and heavy metals through soil. Direct evidence for colloid mobility includes the presence of humic materials in deep aquifers as well as coatings of accumulated clay, organic matter, or sesquioxides on particle or aggregate surfaces in subsoil horizons of many soils. The potential for colloid-facilitated transport of contaminants from hazardous-waste sites requires adequate monitoring before, during, and after in-situ remediation treatments. Zero-tension lysimeters (ZTLs) are especially appropriate for sampling water as it moves through saturated soil, although some unsaturated flow events may be sampled as well. Because no ceramic barrier or fiberglass wick is involved to maintain tension on the water (as is the case with other lysimeters), particles suspended in the water as well as dissolved species may be sampled with ZTLs. In this report, a ZTL design is proposed that is more suitable for monitoring colloid-facilitated contaminant migration. The improved design consists of a cylinder made of polycarbonate or polytetrafluoroethylene (PTFE) that is placed below undisturbed soil material. In many soils, a hydraulically powered tube may be used to extract an undisturbed core of soil before placement of the lysimeter. In those cases, the design has significant advantages over conventional designs with respect to simplicity and speed of installation. Therefore, it will allow colloid-facilitated transport of contaminants to be monitored at more locations at a given site

  19. Evaporation studies on Themeda triandra under field conditions: a ...

    African Journals Online (AJOL)

    In the semi-arid regions of South Africa, the efficiency of water use by natural grazing plants is important and can be used to evaluate the production potentially of comparative grasses. Hydraulic non-floating lysimeters were designed and tested under field conditions and indicated that with accurate calibration for ...

  20. Evapotranspiration studies on Themeda triandra Forsk. under field ...

    African Journals Online (AJOL)

    Hydraulic non-floating lysimeters were used to determine the evapotranspiration (Et) of a Themeda triandra grass cover under field conditions. The highest evapotranspiration losses were recorded during December and January when the plants were in the reproductive phase, provided the soil moisture was not limiting.

  1. Validation of a simple evaporation-transpiration scheme (SETS) to estimate evaporation using micro-lysimeter measurements

    Science.gov (United States)

    Ghazanfari, Sadegh; Pande, Saket; Savenije, Hubert

    2014-05-01

    Several methods exist to estimate E and T. The Penman-Montieth or Priestly-Taylor methods along with the Jarvis scheme for estimating vegetation resistance are commonly used to estimate these fluxes as a function of land cover, atmospheric forcing and soil moisture content. In this study, a simple evaporation transpiration method is developed based on MOSAIC Land Surface Model that explicitly accounts for soil moisture. Soil evaporation and transpiration estimated by SETS is validated on a single column of soil profile with measured evaporation data from three micro-lysimeters located at Ferdowsi University of Mashhad synoptic station, Iran, for the year 2005. SETS is run using both implicit and explicit computational schemes. Results show that the implicit scheme estimates the vapor flux close to that by the explicit scheme. The mean difference between the implicit and explicit scheme is -0.03 mm/day. The paired T-test of mean difference (p-Value = 0.042 and t-Value = 2.04) shows that there is no significant difference between the two methods. The sum of soil evaporation and transpiration from SETS is also compared with P-M equation and micro-lysimeters measurements. The SETS predicts the actual evaporation with a lower bias (= 1.24mm/day) than P-M (= 1.82 mm/day) and with R2 value of 0.82.

  2. Field performance of alternative landfill covers vegetated with cottonwood and eucalyptus trees.

    Science.gov (United States)

    Abichou, Tarek; Musagasa, Jubily; Yuan, Lei; Chanton, Jeff; Tawfiq, Kamal; Rockwood, Donald; Licht, Louis

    2012-01-01

    A field study was conducted to assess the ability of landfill covers to control percolation into the waste. Performance of one conventional cover was compared to that of two evapotranspiration (ET) tree covers, using large (7 x 14 m) lined lysimeters at the Leon County Solid Waste management facility in Tallahassee, Florida. Additional unlined test sections were also constructed and monitored in order to compare soil water storage, soil temperature, and tree growth inside lysimeters and in unlined test sections. The unlined test sections were in direct contact with landfill gas. Surface runoff on the ET covers was a small proportion of the water balance (1% of precipitation) as compared to 13% in the conventional cover. Percolation in the ET covers averaged 17% and 24% of precipitation as compared to 33% in the conventional cover. On average, soil water storage was higher in the lined lysimeters (429 mm) compared to unlined test sections (408 mm). The average soil temperature in the lysimeters was lower than in the unlined test sections. The average tree height inside the lysimeters was not significantly lower (8.04 mfor eucalyptus and 7.11 mfor cottonwood) than outside (8.82 m for eucalyptus and 8.01 m for cottonwood). ET tree covers vegetated with cottonwood or eucalyptus are feasible for North Florida climate as an alternative to GCL covers.

  3. Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies - Effects of macrophytes

    DEFF Research Database (Denmark)

    Chen, Xijuan; Pauly, Udo; Rehfus, Stefan

    2009-01-01

    as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted...... into containers (lysimeters) with a size of 1 m × 1 m × 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under...... environmental conditions. The reduction is most likely due to degradation, since volatilization, uptake into plants and leaching are insignificant. No difference between the containers with different macrophyte species or the unplanted containers was observed. Considering the usual operation time of 10 years...

  4. A study of dissipation, degradation and binding of 14C-labeled endosulfan to soil in model lysimeter

    International Nuclear Information System (INIS)

    Gonzalez, J.E.; Ceballos, J.; Amor, A.; Saiz, E.B. de

    1999-01-01

    The degradation, dissipation and binding of α-endosulfan in two agricultural soils and sand was studied in lysimeter system under outdoor conditions, using 14 C labeled insecticide. Dissipation was rapid during the first few weeks after application. The half life of disappearance was 38 to 61 days for the soils from Cerro Punta and El Ejido, whereas, in sand it was 91 days. The insecticide degraded by oxidation at the sulfite group to the sulfate. The resultant product underwent further degradation to form 14 CO 2 and bound residues. Although a significant amount of 14 C leached through the sand, which contained less that 0.1% organic matter, there was no leaching of endosulfan through the other two types of soil, when leaching was started immediately after treatment. (author)

  5. Elemental Redistribution at the Onset of Soil Genesis from Basalt as Measured in a Soil Lysimeter System

    Science.gov (United States)

    Wang, Y.; Umanzor, M.; Alves Meira Neto, A.; Sengupta, A.; Amistadi, M. K.; Root, R.; Troch, P.; Chorover, J.

    2017-12-01

    Elemental translocation, resulting in enrichment or depletion relative to parent rock, is a consequence of mineral dissolution and precipitation reactions of soil genesis. Accurate measurement of translocation in natural systems is complicated by factors such as parent material heterogeneity and dust deposition. In the present work, a fully controlled and monitored 10° sloping soil lysimeter with known homogeneous initial conditions, was utilized to investigate initial stages of soil genesis from 1 m3 of crushed basalt. Throughout the two-year experiment, periodic irrigation coupled with sensor measurements enabled monitoring of changes in internal moisture states. A total 15-meter water influx resulted in distinct efflux patterns, wetting and drying cycles, as well as high volume water storage. Biological changes, such as algal and grass emergence, were visible on the soil surface, and microbial colonization throughout the profile was measured in a companion study, suggesting that biogeochemical hotspots may have formed. Forensic excavation and sampling of 324 voxels captured the final state heterogeneity of the lysimeter with respect to length and depth. Total elemental concentrations and a five-step sequential extraction (SE) scheme quantified elemental redistributions into operationally-defined pools including exchangeable, poorly-crystalline (hydr)oxides, and crystalline (hydr)oxides. Data were correlated to water flux and storage that was determined from sensor and tracer data over the two years of rock-water interaction; then used to map 2D cross-sections and identify geochemical hotspots. Total and SE Fe concentrations were used to establish a governing mass balance equation, and sub mass balance equations with unique partitioning coefficients of Fe were developed for each SE pool, respectively. The results help to explain elemental (e.g., Fe) lability and redistribution due to physical and geochemical weathering during the initial stages of soil genesis.

  6. Evaluation of field and lysimeter studies on the leaching of pesticides from soil using the PESTLA model

    NARCIS (Netherlands)

    Veen, van de J.R.; Boesten, J.J.T.I.

    1996-01-01

    The PESTLA model Version 2.4 is used to evaluate pesticide leaching from soil under Dutch agricultural conditions. A method is presented to translate the results of a leaching experiment into the standard scenario, using the ratio between measured andcomputed leaching for that experiment. An attempt

  7. Combined effect of capillary barrier and layered slope on water, solute and nanoparticle transfer in an unsaturated soil at lysimeter scale.

    Science.gov (United States)

    Prédélus, Dieuseul; Coutinho, Artur Paiva; Lassabatere, Laurent; Bien, Le Binh; Winiarski, Thierry; Angulo-Jaramillo, Rafael

    2015-10-01

    It is well recognized that colloidal nanoparticles are highly mobile in soils and can facilitate the transport of contaminants through the vadose zone. This work presents the combined effect of the capillary barrier and soil layer slope on the transport of water, bromide and nanoparticles through an unsaturated soil. Experiments were performed in a lysimeter (1×1×1.6m(3)) called LUGH (Lysimeter for Urban Groundwater Hydrology). The LUGH has 15 outputs that identify the temporal and spatial evolution of water flow, solute flux and nanoparticles in relation to the soil surface conditions and the 3D system configuration. Two different soil structures were set up in the lysimeter. The first structure comprises a layer of sand (0-0.2cm, in diameter) 35cm thick placed horizontally above a layer of bimodal mixture also 35cm thick to create a capillary barrier at the interface between the sand and bimodal material. The bimodal material is composed of a mixture 50% by weight of sand and gravel (0.4-1.1cm, in diameter). The second structure, using the same amount of sand and bimodal mixture as the first structure represents an interface with a 25% slope. A 3D numerical model based on Richards equation for flow and the convection dispersion equations coupled with a mechanical module for nanoparticle trapping was developed. The results showed that under the effect of the capillary barrier, water accumulated at the interface of the two materials. The sloped structure deflects flow in contrast to the structure with zero slope. Approximately 80% of nanoparticles are retained in the lysimeter, with a greater retention at the interface of two materials. Finally, the model makes a good reproduction of physical mechanisms observed and appears to be a useful tool for identifying key processes leading to a better understanding of the effect of capillary barrier on nanoparticle transfer in an unsaturated heterogeneous soil. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Lysimeter experiments to determine the ability of soil to reduce concentrations of BOD, available P and inorganic N in dirty water.

    Science.gov (United States)

    Brookman, S K E; Chadwick; Retter, A R

    2005-11-01

    Lysimeter experiments were conducted to determine the ability of different soils to reduce levels of biochemical oxygen demand (BOD) and concentrations of molybdate reactive phosphorus (MRP) and ammonium-N (NH4(+)-N) in dirty water and the impact of applications on nitrate leaching. An additional experiment investigated the effect of dirty water components on leaching quality. This information is required to assess the potential risk of dirty water applications on polluting groundwater and to assess the use of such soils in the development of treatment systems for dirty water. Intact and disturbed soil lysimeters, 0.5 and 1m deep were constructed from four soils; a coarse free-draining sandy loam, a sandy loam over soft sandstone, a calcareous silty clay over chalk and a sandy loam over granite. For the coarse free-draining sandy loam, lysimeters were also constructed from disturbed soil with and without the addition of lime, to assess if this could increase phosphorus immobilisation. Levels of BOD and concentrations of MRP, NH4(+)-N and nitrate (NO3(-)-N) of leachates were measured following dirty water applications at 2 and 8 mm day(-1) under laboratory conditions. Under the daily 2mm application, all soils were effective at treating dirty water, reducing concentrations of BOD, MRP and NH4(+)- N by > or = 98% but NO3(-)-N concentrations increased up to 80 mg l(-1) from the 0.5 m deep lysimeters of the sandy loam over granite. Soils were less effective at reducing levels of BOD, MRP and NH4(+)- N at the 8 mm daily rate of application, with maximum NO3(-)-N concentrations of leachates of 200 mg l(-1) from disturbed soils.

  9. Composition and properties of soil solution in the Podzolic soil of a green moss-spruce stand according to lysimeter data

    Energy Technology Data Exchange (ETDEWEB)

    Shilova, E I; Korovkina, L V

    1964-01-01

    Lysimeter water from an acid Podzolic soil in a green moss - spruce stand always contained free CO/sub 2/ and bicarbonates. Titrable acidity (as a result of CO/sub 2/) showed the following averages by horizons for the period of observation: 0.86 meq/liter. (A/sub 0/A/sub 1/), 0.67 meq/liter (A/sub 2/), and 0.98 meq per liter (B). The corresponding alkalinities were: 0.69, 0.51, and 2.50 meq/liter. Bicarbonates were the principal mineral components of the soil solution. Their concentration in the litter (A/sub 0/A/sub 1/) was relatively low; it reached a minimum in the Podzolic horizon, and then increased sharply in the illuvial horizon. The seasonal dynamics of bicarbonates in the lower part of the profile were not related to changes in bicarbonate content in the upper horizons. It followed the cycle of plant activity. The autumn lysimeter water, formed by displacement of the upper soil solution, showed maximum concentration of bicarbonates. The spring lysimeter water, and partly the summer water, which form following the period of winter anabiosis, showed the lowest concentration. As the plants absorb water, the roots evolve carbon dioxide. The higher the summer temperature, the more bicarbonates accumulate in the soil.

  10. Lysimeter studies on the behavior of persistant organic pollutants in the soil-plant-system (1989-1994). Vol. 2. The behavior of 14C fluoranthene and 14C benzo(a)pyrene and also 14C PCB 28 and 14C PCB 52 in the agroecosystem - lysimeter experiments with an orthic luvisol. Final report

    International Nuclear Information System (INIS)

    Schnoeder, F.; Mittelstaedt, W.; Fuehr, F.

    1995-11-01

    14 C-labelled PAH and PCB (benzo(a)pyrene/fluoranthene resp. PCB 28/PCB 52) were mixed into the A n horizon of the lysimeters containing soil cores of an Orthic Luvisol which had been removed undisturbed. Carrots (1990), winter wheat and spinach (1991), potatoes and kale (1992) were grown to harvest maturity. Radio-HPLC enabled the selective enrichment of radioactive substances from extracts of soil, plant and leachate samples in high-purity fractions for GC/MS analyses. Additionally degradation studies with benzo(a)pyrene and fluoranthene have been carried out. In the PAH-lysimeter the concentration of radioactivity in the soil dropped to less than 50% of the initial value after 4 months and after 28 months to about 30%. This can be attributed to mineralisation of fluoranthene. An increasing formation of bound residues was determined either in lysimeter as well as in the degradation study, which finally amounted to more than 50% of the 14 C activity persisting in the soil, of which 2/3 was located in the humin fraction and roughly equal fraction of the remainder in the fulvic and humic acids. Apart from the parent substances both in the lysimeter and degradation study three benzo(a)pyrene quinones were characterised and a non-polar metabolite of benzo(a)pyren with unknown structure was isolated. In the PCB-lysimeter the concentration of the radioactivity in the soil remained almost unchanged throughout 28 months. Metabolites of PCB could not be detected. A total of 0.58% (PCBs) and 0.16% (PAHs) of the radioactivity applied was recovered in the plants. The highest concentration has been determined in carrots, lower concentrations have been found in the subsequent crops and only the PCB cogeneres were detectable in small quantities ( [de

  11. Measurement of magnetic susceptibility on tailings cores report on cores obtained from the Ontario Research Foundation lysimeter experiment

    International Nuclear Information System (INIS)

    1984-10-01

    Bulk susceptibility and induced magnetic remanence results are reported for 40 cores obtained from the uranium tailings lysimeter experiment at the Ontario Research Foundation. Both methods indicate a broad threefold subdivision of the tailings pile. An upper zone is characterized by an enhanced susceptibility level, which is related to enhanced concentration of both magnetite and hematite. Depletion zones, where present, are of limited areal extent and strongly developed. An intermediate zone is characterized by a mixture of large areas of reduced susceptibility that separate smaller regions of slightly enhanced susceptibility. The zones of susceptibility depletion appear to define a dendritic drainage pattern. Locally in this zone magnetite is enhanced and hematite depleted. In the lowermost zone susceptibility levels are reduced over most of the tailings bed. Only in the upper most right hand corner is there any vestige of a positive susceptibility concentration. Both magnetite and hematite are strongly depleted in this lower zone. Visually it is apparent that this lowermost depleted zone correlates to the zones of strongest 'yellowcake' development

  12. Removal of personal care compounds from sewage sludge in reed bed container (lysimeter) studies--effects of macrophytes.

    Science.gov (United States)

    Chen, Xijuan; Pauly, Udo; Rehfus, Stefan; Bester, Kai

    2009-10-15

    Sludge reed beds have been used for dewatering (draining and evapotranspiration) and mineralisation of sludge in Europe since 1988. Although reed beds are considered as a low cost and low contamination method in reducing volume, breaking down organic matter and increasing the density of sludge, it is not yet clear whether this enhanced biological treatment is suitable for degradation of organic micro-pollutants such as personal care products. Within this project the effect of biological sludge treatment in a reed bed on reducing the concentrations of the fragrances HHCB, AHTN, OTNE was studied as on the bactericide Triclosan. Additionally, the capacity of different macrophytes species to affect the treatment process was examined. Three different macrophyte species were compared: bulrush (Typha latifolia), reed (Phragmites australis) and reed canary grass (Phalaris arundinacea). They were planted into containers (lysimeters) with a size of 1 m x 1 m x 1 m which were filled with 20 cm gravel at the bottom and 50 cm sludge on top, into which the macrophytes were planted. During the twelve months experiment reduction of 20-30% for HHCB and AHTN, 70% for Triclosan and 70% for OTNE were determined under environmental conditions. The reduction is most likely due to degradation, since volatilization, uptake into plants and leaching are insignificant. No difference between the containers with different macrophyte species or the unplanted containers was observed. Considering the usual operation time of 10 years for reed beds, an assessment was made for the whole life time.

  13. Nitrate leaching from winter cereal cover crops using undisturbed soil-column lysimeters

    Science.gov (United States)

    Cover crops are important management practices for reducing nitrogen (N) leaching in the Chesapeake Bay watershed, which is under Total Maximum Daily Load restraints. Cool-season annual grasses such as barley, rye, or wheat are common cover crops, but studies are needed to directly compare field ni...

  14. Large-scale lysimeter site St. Arnold, Germany: analysis of 40 years of precipitation, leachate and evapotranspiration

    Directory of Open Access Journals (Sweden)

    N. Harsch

    2009-03-01

    Full Text Available This study deals with a lysimetrical-meteorological data series collected on the large-scale lysimeter site "St. Arnold", Germany, from November 1965 to April 2007. The particular relevance of this data rests both upon its perdurability and upon the fact that the site is comprised of a grassland basin, an oak/beech and a pine basin.

    Apart from analyzing long term trends of the meteorological measurements, the primary objective of this study is to investigate the water balance in grassland and forested basins, in particular comparing the precipitation term to leachate quantities and potential and actual evapotranspiration. The latter are based upon the Penman and the Penman-Monteith approaches, respectively.

    The main results of this survey are that, on a long-term average, the grassland basin turns more than half (53% of its annually incoming precipitation into leachate and only 36% into water vapour, while the deciduous forest exhibits a ratio of 37% for leachate and 56% for evapotranspiration, and the evergreen coniferous forest shows the highest evaporation rate (65% and the lowest leachate rate (26%.

    Concerning these water balances, considerable differences both between basins and between seasons stand out. While summer periods exhibit high evapotranspiration rates for the forests and moderate ones for the grassland, winter periods are characterised by considerable leachate quantities for grassland and the deciduous forest and moderate ones for the coniferous forest. Following the analysis of the climatic development in St. Arnold, trends towards a milder and more humid regional climate were detected.

  15. Reatividade de corretivos da acidez e condicionadores de solo em colunas de lixiviação Reactivity of soil acidity correctives and conditioners in lysimeters

    Directory of Open Access Journals (Sweden)

    Lucélia Alves Ramos

    2006-10-01

    mobility and slow correction in the soil profile. Other products have been tested for acidity correction such as silicates or the reduction of acidity effects in deeper soil layers with gypsum. This study compared the effect of lime, gypsum and silicates to supply calcium, magnesium, silicate and to correct soil pH in deeper soil layers. Soil samples of an Ustoxic Quartzipsamment were used, collected under native forest, with low levels of exchangeable Ca and Mg and high acidity. Lysimeters were prepared, divided into 12 rings of 5cm and filled with the collected soil. In the top ring (0-5 cm the equivalent to 500 or 1.000 kg ha-1 calcium silicate (Wollastonite, Ca and Mg silicate, thermophosphate, commercial (calcitic lime, and agricultural gypsum were incorporated, in a randomized block design with 4 replications. The soil columns were incubated (moisture near field capacity for 40 days, irrigated with 2.000 mm distilled water (five times/week during the incubation period. Available silicon, exchangeable Ca and Mg and pH (CaCl2 were determined. Gypsum increased Ca levels throughout the soil profile, but did not correct the acidity. Silicates did correct soil acidity and were more effective than lime for soil pH correction and to increase exchangeable Ca levels. Use of calcium and magnesium silicate or of thermophosphate increased the soil magnesium concentration to a depth of 25 cm. The measured Silicon was transported to the deepest soil layer in the lysimeters (55 cm, independently of the tested Si source.

  16. fields

    Directory of Open Access Journals (Sweden)

    Brad J. Arnold

    2014-07-01

    Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

  17. Influence of a heavy rainfall event on the leaching of [{sup 14}C]isoproturon and its degradation products in outdoor lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Doerfler, Ulrike [GSF-National Research Centre for Environment and Health, Institute of Soil Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)]. E-mail: doerfler@gsf.de; Cao Guoyin [Chinese Academy of Agricultural Sciences, Beijing (China); Grundmann, Sabine [GSF-National Research Centre for Environment and Health, Institute of Soil Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Schroll, Reiner [GSF-National Research Centre for Environment and Health, Institute of Soil Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)

    2006-11-15

    In four different agricultural soils the long-term leaching behaviour of [{sup 14}C]isoproturon was studied in outdoor lysimeters (2 m length, 1 m{sup 2} surface area). The herbicide was applied in spring 1997 and spring 2001. At the end of the first 4-year-investigation period between 0.13% and 0.31% of the applied radioactivity was leached. Isoproturon or known metabolites could not be detected in the leachate. However, shortly after the second application isoproturon and its degradation products 2-hydroxy-isoproturon and monodemethyl-isoproturon were leached via preferential flow in one of the lysimeters (Mollic gleysol) in concentrations of 4.5 {mu}g L{sup -1}, 3.1 {mu}g L{sup -1} and 0.9 {mu}g L{sup -1}, respectively, thus considerably exceeding the EU threshold limit of 0.1 {mu}g L{sup -1} for ground and drinking water. The results indicate that in soils where mass flow transfer dominates, leaching of isoproturon to groundwater is of low probability whereas in highly structured soils which have the tendency to form macropores, isoproturon can be transported via preferential flow to the groundwater. - In a heavy clay soil isoproturon and its degradation products can be leached to the groundwater via preferential flow.

  18. Influence of a heavy rainfall event on the leaching of [14C]isoproturon and its degradation products in outdoor lysimeters.

    Science.gov (United States)

    Dörfler, Ulrike; Cao, Guoyin; Grundmann, Sabine; Schroll, Reiner

    2006-11-01

    In four different agricultural soils the long-term leaching behaviour of [14C]isoproturon was studied in outdoor lysimeters (2 m length, 1 m2 surface area). The herbicide was applied in spring 1997 and spring 2001. At the end of the first 4-year-investigation period between 0.13% and 0.31% of the applied radioactivity was leached. Isoproturon or known metabolites could not be detected in the leachate. However, shortly after the second application isoproturon and its degradation products 2-hydroxy-isoproturon and monodemethyl-isoproturon were leached via preferential flow in one of the lysimeters (Mollic gleysol) in concentrations of 4.5 microg L-1, 3.1 microg L-1 and 0.9 microg L-1, respectively, thus considerably exceeding the EU threshold limit of 0.1 microg L-1 for ground and drinking water. The results indicate that in soils where mass flow transfer dominates, leaching of isoproturon to groundwater is of low probability whereas in highly structured soils which have the tendency to form macropores, isoproturon can be transported via preferential flow to the groundwater.

  19. Influence of a heavy rainfall event on the leaching of [14C]isoproturon and its degradation products in outdoor lysimeters

    International Nuclear Information System (INIS)

    Doerfler, Ulrike; Cao Guoyin; Grundmann, Sabine; Schroll, Reiner

    2006-01-01

    In four different agricultural soils the long-term leaching behaviour of [ 14 C]isoproturon was studied in outdoor lysimeters (2 m length, 1 m 2 surface area). The herbicide was applied in spring 1997 and spring 2001. At the end of the first 4-year-investigation period between 0.13% and 0.31% of the applied radioactivity was leached. Isoproturon or known metabolites could not be detected in the leachate. However, shortly after the second application isoproturon and its degradation products 2-hydroxy-isoproturon and monodemethyl-isoproturon were leached via preferential flow in one of the lysimeters (Mollic gleysol) in concentrations of 4.5 μg L -1 , 3.1 μg L -1 and 0.9 μg L -1 , respectively, thus considerably exceeding the EU threshold limit of 0.1 μg L -1 for ground and drinking water. The results indicate that in soils where mass flow transfer dominates, leaching of isoproturon to groundwater is of low probability whereas in highly structured soils which have the tendency to form macropores, isoproturon can be transported via preferential flow to the groundwater. - In a heavy clay soil isoproturon and its degradation products can be leached to the groundwater via preferential flow

  20. Multitracer studies for determining seepage water and anion movement in four types of soil using lysimeters with different functions and designs; Multitracer-Untersuchungen zur Bestimmung der Sickerwasser- und Anionenbewegung in vier Bodenformen bei Lysimetern unterschiedlicher Nutzung und Bauart

    Energy Technology Data Exchange (ETDEWEB)

    Knappe, S.; Russow, R. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung; Seeger, J. [Lysimeterstation Falkenberg (Germany)

    1999-02-01

    Lysimeter experiments based on the stable isotope tracer technique are a suitable means of examining the complex relationships governing water and material transport processes in the soil. The present paper reports on experiments in which water and nitrate movement was traced directly by means of lysimeters placed at different depths and using deuterium water and [{sup 15}N]N-nitrate for pulse marking. Extensive investigations carried out during the dissection of soil monoliths that had been used for many years in lysimeters offered an opportunity for stable isotope tracer studies aimed at determining seepage water and anion movement in undisturbed soils and, after dismantling the lysimeters, conducting soil analyses to find out more about the fate of nonpercolated tracers at various soil depths. Following other authors, bromide anions were additionally used as conservative tracers. [Deutsch] Zur Untersuchung der komplexen Zusammenhaenge des Wasser- und Stofftransportes im Boden bieten sich Lysimeterversuche unter Nutzung der stabilisotopen Tracertechnik an. In der vorliegenden Arbeit wird zunaechst ueber die direkte Verfolgung der Wasser- und Nitrat-Bewegung in tiefengestaffelten Lysimetern durch Pulsmarkierung mit Deuteriumwasser und [{sup 15}N]Nitrat berichtet. Im Rahmen von umfangreichen Untersuchungen bei der Zerlegung von langjaehrig in Lysimetern genutzten Bodenmonolithen bestand des weiteren die Moeglichkeit, stabilisotope Traceruntersuchungen zur Bestimmung der Sickerwasser- und Anionenbewegung an ungestoerten Boeden durchzufuehren und nach der Zerlegung der Lysimeter ueber entsprechende Analysen des Bodens Aussagen zum Verbleib der nicht perkolierten Tracer in verschiedenen Bodentiefen zu treffen. Zusaetzlich wurde dabei das von anderen Autoren bereits genutzte Bromid-Anion als sogenannter konservativer Tracer eingesetzt. (orig.)

  1. Evaluation of Plant- Compost -Microorganisms Synergy for the Remediation of Diesel contaminated Soil: Success Stories from the Field Station

    Science.gov (United States)

    Hussain, Imran; Wimmer, Bernhard; Soja, Gerhard; Sessitsch, Angela; Reichenauer, Thomas G.

    2016-04-01

    Total petroleum hydrocarbons (TPH) contain a mixture of crude oil, gasoline, creosote and diesel is one of the most common groups of persistent organic pollutants. TPH enters into the ecosystem (soil, water and air) through leakage of underground storage tanks (LUST), accidental oil spills, transportation losses and industrial processes. Pollution associated with diesel oil and its refined products is of great concern worldwide due to its threats/damages for human and ecosystem health, soil structure and ground water quality. Extensive soils pollution with petroleum hydrocarbons results in extreme harsh surroundings, produce hydrophobic conditions and infertile soils that ultimately lead towards less plant and microorganisms growth. Among biological methods, bioremediation and phytoremediation are promising technologies that have both technical and ecological benefits as compared to convention methods. Within phytoremediation, rhizoremediation based on stimulation of degrading microorganism's population influenced by plant rhizospheric effect is known as main mechanism for phytoremediation of petroleum polluted soils. Composting along with rhizodegradtion was used to remediate freshly spilled soils at Lysimeter station Siebersdof, Austria. Experiment was started in July 2013 and will be monitored up to September 2016. Field station has 12 Lysimeter in total; each has length, width and depth of 100 cm respectively. Each Lysimeter was filled with normal agricultural soil from Siebersdof (0-70 cm), sand (70-85 cm) and stones (85-100cm). Sand and stones were added to support the normal leaching and percolation of water as we collected leachate samples after regular intervals. After filling, commercial diesel oil (2% w/w of 0-70 cm soil) was spilled on top of each Lysimeter as accidental spill occurs in filed. Compost was added at 0-15 cm layer (5% w/w of soil) to stimulate plant as well as microorganisms growth. Whole Lysimeter station was divided into three treatments

  2. Degradation and leaching behaviour of 14C-glufosinate in a silty sand soil. Experiments in outdoor lysimeters with undisturbed soil cores

    International Nuclear Information System (INIS)

    Kubiak, R.

    1996-12-01

    Degradation and leaching behaviour of 14 C-labelled glufosinate in a silty sand soil was investigated in two outdoor lysimeters after repeated application of 12.5 litres/hectare (1/ha) Basta (divided in 7.5 and 5 l/ha respectively). The 14 C-loss during application was 4.8-8.2%. The 14 C-content in the plants (vines and weeds) was 0.3% of that applied at the most. After 130 days, 25.9 and 25.5% of the applied material was found in the soil up to a depth of 40 cm. One year after the first application, this amount was still 18.5 and 18.6%. As a consequence of the renewed spraying, the detected amounts of 14 C were 44.3 and 43.1% some 107 days after the first application in the second experimental year. The additional investigation in lysimeter 2 after 373 days showed a decrease to 33.9%. Most of the detected radioactivity remained in the 0-10 cm soil layer. At the end of the experiment, the amount of 14 C in the 30-40 cm layer was 0.5%. The total residues in the 0-10 cm soil layer were less than 1 mg/kg at all dates of sampling, and only a small amount still represented the free acid of the active ingredient. The average values were 0.05 mg/kg after 130 days, 0.01 mg/kg after 363 days and 0.09 mg/kg at the following date of sampling. In the spring of the following year, no residues of the free acid were detectable. The radioactivity in the percolate amounted to a maximum of 0.11% of that applied and in no case represented the free acid of the ammonium salt. (author)

  3. Degradation and leaching behaviour of {sup 14}C-glufosinate in a silty sand soil. Experiments in outdoor lysimeters with undisturbed soil cores

    Energy Technology Data Exchange (ETDEWEB)

    Kubiak, R

    1996-12-01

    Degradation and leaching behaviour of {sup 14}C-labelled glufosinate in a silty sand soil was investigated in two outdoor lysimeters after repeated application of 12.5 litres/hectare (1/ha) Basta (divided in 7.5 and 5 l/ha respectively). The {sup 14}C-loss during application was 4.8-8.2%. The {sup 14}C-content in the plants (vines and weeds) was 0.3% of that applied at the most. After 130 days, 25.9 and 25.5% of the applied material was found in the soil up to a depth of 40 cm. One year after the first application, this amount was still 18.5 and 18.6%. As a consequence of the renewed spraying, the detected amounts of {sup 14}C were 44.3 and 43.1% some 107 days after the first application in the second experimental year. The additional investigation in lysimeter 2 after 373 days showed a decrease to 33.9%. Most of the detected radioactivity remained in the 0-10 cm soil layer. At the end of the experiment, the amount of {sup 14}C in the 30-40 cm layer was 0.5%. The total residues in the 0-10 cm soil layer were less than 1 mg/kg at all dates of sampling, and only a small amount still represented the free acid of the active ingredient. The average values were 0.05 mg/kg after 130 days, 0.01 mg/kg after 363 days and 0.09 mg/kg at the following date of sampling. In the spring of the following year, no residues of the free acid were detectable. The radioactivity in the percolate amounted to a maximum of 0.11% of that applied and in no case represented the free acid of the ammonium salt. (author)

  4. Accurate measurements of vadose zone fluxes using automated equilibrium tension plate lysimeters: A synopsis of results from the Spydia research facility, New Zealand.

    Science.gov (United States)

    Wöhling, Thomas; Barkle, Greg; Stenger, Roland; Moorhead, Brian; Wall, Aaron; Clague, Juliet

    2014-05-01

    Automated equilibrium tension plate lysimeters (AETLs) are arguably the most accurate method to measure unsaturated water and contaminant fluxes below the root zone at the scale of up to 1 m². The AETL technique utilizes a porous sintered stainless-steel plate to provide a comparatively large sampling area with a continuously controlled vacuum that is in "equilibrium" with the surrounding vadose zone matric pressure to ensure measured fluxes represent those under undisturbed conditions. This novel lysimeter technique was used at an intensive research site for investigations of contaminant pathways from the land surface to the groundwater on a sheep and beef farm under pastoral land use in the Tutaeuaua subcatchment, New Zealand. The Spydia research facility was constructed in 2005 and was fully operational between 2006 and 2011. Extending from a central access caisson, 15 separately controlled AETLs with 0.2 m² surface area were installed at five depths between 0.4 m and 5.1 m into the undisturbed volcanic vadose zone materials. The unique setup of the facility ensured minimum interference of the experimental equipment and external factors with the measurements. Over the period of more than five years, a comprehensive data set was collected at each of the 15 AETL locations which comprises of time series of soil water flux, pressure head, volumetric water contents, and soil temperature. The soil water was regularly analysed for EC, pH, dissolved carbon, various nitrogen compounds (including nitrate, ammonia, and organic N), phosphorus, bromide, chloride, sulphate, silica, and a range of other major ions, as well as for various metals. Climate data was measured directly at the site (rainfall) and a climate station at 500m distance. The shallow groundwater was sampled at three different depths directly from the Spydia caisson and at various observation wells surrounding the facility. Two tracer experiments were conducted at the site in 2009 and 2010. In the 2009

  5. Lysimeter experiments on root uptake of Co-60, Sr-90 and Cs-137 from soil into vine and apple trees and on the transfer into grapes and apples

    International Nuclear Information System (INIS)

    Steffens, W.; Foerstel, H.; Mittelstaedt, W.

    1993-01-01

    In lysimeters filled with two different soil types (Parabraunerde and Podzol) the transfer of 60 Co, 90 Sr and 137 Cs from soil into vine and apple trees was investigated over a time period of 5 years (1988-1992). The soil was contaminated in 1978, so that at the beginning of the experiment the radionuclides were already aged. Due to the low availability for root uptake, the transfer of 60 Co and 137 Cs into vine and apple trees was very low. 90 Sr was fairly available for root uptake which caused a considerable uptake and translocation into vegetative plant parts. The physiological behaviour of the radionuclides investigated determined generally a low transfer into must and apples. This was confirmed by the transfer factors variing between 0.001 and 0.029 for 60 Co, 0.01 and 0.036 for 90 Sr and 0.001 and 0.109 for 137 Cs, respectively. The corresponding values in apples were in the same order of magnitude. The influence of the soil type is shown by the higher incorporation of 60 Co, 90 Sr and 137 Cs into the single plant organs and by the higher transfer factors in must and apples grown on the podzolic soil. (orig.) [de

  6. Results of about a seven years lysimeter study to the quantification of the mobility of radionuclides into the system soil-water-plant

    International Nuclear Information System (INIS)

    Gerzabek, M.H.; Strebl, F.; Temmel, B.

    1999-04-01

    The result of seven years lysimeter experiments (twelve soil monoliths, four soil types) to determine the uptake of 60 Co, 137 Cs and 226 Ra into agricultural crops and the leaching behaviour are presented. The mobility of the artificial radionuclides in soil profiles decreased in the following order: 60 Co ≥ 22 6Ra > 137 Cs. Total median values of soil-plant transfer factors (dry matter basis) for the three radionuclides decreased from 226 Ra (0.068 kg kg -1 ) to 137 Cs (0.043 kg kg -1 ) and 60 Co (0.018 kg kg -1 ). The physical and chemical properties of the experimental soils resulted in significant differences in transfer factors or fluxes between the investigated soils for 137 Cs and 226 Ra, but not for 60 Co. Differences in transfer between plant species and plant parts are distinct, with graminaceous species showing 5.8 and 15 times lower values for 137 Cs and 60 Co than dicodyle-donean species. In model calculations radionuclide losses through the different pathways (physical decay, leaching plant uptake and removal) were quantified. (author)

  7. Sicherung mathematischer Grundkompetenzen am Beispiel des österreichischen Zentralabiturs

    Science.gov (United States)

    Peschek, Werner

    Der österreichische Nationalrat (Parlament) hat im Sommer 2009 eine Neugestaltung der Reifeprüfung (Abitur) beschlossen; die wesentlichste Änderung besteht darin, dass die Aufgabenstellungen der für alle Schülerinnen und Schüler verbindlichen schriftlichen Reifeprüfung (sRP) in den Fächern Deutsch, Mathematik und einer lebenden Fremdsprache zentral und nicht wie bisher durch die jeweilige Klassenlehrerin bzw. den Klassenlehrer erfolgen. Für die Allgemeinbildenden Höheren Schulen ("Gymnasien") soll diese neue Regelung ab dem Schuljahr 2013/14 gelten, für die Berufsbildenden Höheren Schulen (u. a. höhere technische oder kaufmännische Schulen mit Abitur) ab dem Schuljahr 2014/15.

  8. Determinación del consumo de agua del duraznero por lisimetría Determination of water use in peach trees with a lysimeter

    Directory of Open Access Journals (Sweden)

    Lucía Puppo

    2010-01-01

    Full Text Available En el año 2004 se instaló un lisímetro de compensación de 2 x 2 x 0,80 m con capa freática constante en un monte de durazneros, con el objetivo de estudiar el consumo de agua de ese cultivo en la región sur del Uruguay. Las mediciones se hicieron en las tres primeras temporadas de crecimiento. El consumo en la primera temporada alcanzó valores de 5 mm d-1, equivalente a 56 L en el marco de plantación. En la segunda temporada llegó a 6 mm d-1 (68 L, aunque alcanzó valores extremos de más de 7 mm d-1. Cuando el árbol alcanzó su tamaño adulto, el consumo máximo se mantuvo alrededor de los 6 mm d-1, aunque este valor se alcanzó más temprano que en la temporada anterior. Este adelanto se correspondió con un mayor índice de área foliar (IAF. El coeficiente de cultivo (Kc fue de alrededor de 1,2 en la primera temporada, y de 1,4 en las dos siguientes. Se calcularon los coeficientes de base (Kcb y su valor se ajustó por el modelo tri-segmentado. Su valor fue de 0,91 en la primera temporada, 1,04 en la segunda y 1,20 en la tercera. Se hacen algunas observaciones metodológicas sobre el uso de este lisímetro, proponiéndose incorporar la variación de agua en el suelo a la ecuación de balance de volúmenes y se propone adicionar riego desde la superficie.A compensation lysimeter with constant freatic water table of 2 x 2 x 0.80 m was installed in 2004 in a peach grove, in order to study the crop water consumption in the south of Uruguay. Measurements were taken in the first three growing seasons. Evapotranspiration at the first season reached 5 mm d-1, equivalent to 56 L in the whole area. In the second season, it went up to 6 mm d-1 (68 L, reaching extreme values of 7 mm d-1 and more. When the tree reached its adult size, the maximum consumption remained around 6 mm d-1, although this value was reached earlier than the season before. This early behavior came together with higher leaf area index (LAI. The crop coefficient (Kc was

  9. Effect of application of dairy manure, effluent and inorganic fertilizer on nitrogen leaching in clayey fluvo-aquic soil: A lysimeter study.

    Science.gov (United States)

    Fan, Jianling; Xiao, Jiao; Liu, Deyan; Ye, Guiping; Luo, Jiafa; Houlbrooke, David; Laurenson, Seth; Yan, Jing; Chen, Lvjun; Tian, Jinping; Ding, Weixin

    2017-08-15

    Dairy farm manure and effluent are applied to cropland in China to provide a source of plant nutrients, but there are concerns over its effect on nitrogen (N) leaching loss and groundwater quality. To investigate the effects of land application of dairy manure and effluent on potential N leaching loss, two lysimeter trials were set up in clayey fluvo-aquic soil in a winter wheat-summer maize rotation cropping system on the North China Plain. The solid dairy manure trial included control without N fertilization (CK), inorganic N fertilizer (SNPK), and fresh (RAW) and composted (COM) dairy manure. The liquid dairy effluent trial consisted of control without N fertilization (CF), inorganic N fertilizer (ENPK), and fresh (FDE) and stored (SDE) dairy effluent. The N application rate was 225kgNha -1 for inorganic N fertilizer, dairy manure, and effluent treatments in both seasons. Annual N leaching loss (ANLL) was highest in SNPK (53.02 and 16.21kgNha -1 in 2013/2014 and 2014/2015, respectively), which were 1.65- and 2.04-fold that of COM, and 1.59- and 1.26-fold that of RAW. In the effluent trial (2014/2015), ANLL for ENPK and SDE (16.22 and 16.86kgNha -1 , respectively) were significantly higher than CF and FDE (6.3 and 13.21kgNha -1 , respectively). NO 3 - contributed the most (34-92%) to total N leaching loss among all treatments, followed by dissolved organic N (14-57%). COM showed the lowest N leaching loss due to a reduction in NO 3 - loss. Yield-scaled N leaching in COM (0.35kgNMg -1 silage) was significantly (Pleaching loss while ensuring high crop yield in the North China Plain. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Leaching of saltstone: Laboratory and field testing and mathematical modeling

    International Nuclear Information System (INIS)

    Grant, M.W.; Langton, C.A.; Oblath, S.B.; Pepper, D.W.; Wallace, R.M.; Wilhite, E.L.; Yau, W.W.F.

    1987-01-01

    A low-level alkaline salt solution will be a byproduct in the processing of high-level waste at the Savannah River Plant (SRP). This solution will be incorporated into a wasteform, saltstone, and disposed of in surface vaults. Laboratory and field leach testing and mathematical modeling have demonstrated the predictability of contaminant release from cement wasteforms. Saltstone disposal in surface vaults will meet the design objective, which is to meet drinking water standards in shallow groundwater at the disposal area boundary. Diffusion is the predominant mechanism for release of contaminants to the environment. Leach testing in unsaturated soil, at soil moisture levels above 1 wt %, has shown no difference in leach rate compared to leaching in distilled water. Field leach testing of three thirty-ton blocks of saltstone in lysimeters has been underway since January 1984. Mathematical models were applied to assess design features for saltstone disposal. One dimensional infinite-composite and semi-infinite analytical models were developed for assessing diffusion of nitrate from saltstone through a cement barrier. Numerical models, both finite element and finite difference, were validated by comparison of model predictions with the saltstone lysimeter results. Validated models were used to assess the long-term performance of the saltstone stored in surface vaults. The maximum concentrations of all contaminants released from saltstone to shallow groundwater are predicted to be below drinking water standards at the disposal area boundary. 5 refs., 11 figs., 5 tabs

  11. Seepage water flow velocity in hydromorphic acid brown earth in northeast Germany - {sup 15}N studies in groundwater lysimeters; Sickerwassergeschwindigkeit in Hydromorphen Sauerbraunerden Nordostdeutschlands - {sup 15}N-Untersuchungen in Grundwasserlysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, A.; Hoelzel, D.; Schalitz, G. [ZALF Muencheberg, Paulinenaue (Germany). Forschungstation; Merbach, W. [ZALF Muencheberg, Paulinenaue (Germany). Inst. fuer Rhizosphaerenforschung und Pflanzenernaehrung

    1999-02-01

    Sandy soils occur widely in Brandenburg. These soils are usually characterised by a high permeability. In low-lying areas such the Havellaendische Luch their proximity to groundwater can pose problems, especially when nutrients such as nitrate are not fully absorbed by the plants and are leached into the ground. Lysimeter studies with stable isotope tracers are especially well suited for estimating the leaching loss attributable to mineral fertilisation. For one thing, lateral flow can largely be excluded in the closed system of a lysimeter. For another, one can reasonably suppose that the marked nitrogen does not behave essentially differently from normal nitrogen. [Deutsch] In Brandenburg kommen verbreitet sandige Boeden vor. Diese Boeden zeichnen sich meist durch hohe Durchlaessigkeiten aus. Dadurch kann in Niederungsgebieten, wie dem Havellaendischen Luch, die Grundwassernaehe zum Problem werden, insbesondere wenn Naehrstoffe wie Nitrat nicht vollstaendig von den Pflanzen aufgenommen werden und der Auswaschung anheimfallen. Zur Abschaetzung der Auswaschungsverluste, die tatsaechlich aus der Mineralduengung stammen, eignen sich besonders Lysimeteruntersuchungen mit stabilisotopen Tracern. Einerseits lassen sich hier, im geschlossenen System, laterale Stroemungen weitgehend ausschliessen, andererseits kann man davon ausgehen, dass sich der makierte Stickstoff im System Boden-Pflanze nicht grundsaetzlich anders verhaelt als herkoemmlicher Stickstoff. (orig.)

  12. Nitrogen Fertilizer Rate and Crop Management Effects on Nitrate Leaching from an Agricultural Field in Central Pennsylvania

    Directory of Open Access Journals (Sweden)

    Richard H. Fox

    2001-01-01

    Full Text Available Eighteen pan lysimeters were installed at a depth of 1.2 m in a Hagerstown silt loam soil in a corn field in central Pennsylvania in 1988. In 1995, wick lysimeters were also installed at 1.2 m depth in the same access pits. Treatments have included N fertilizer rates, use of manure, crop rotation (continuous corn, corn-soybean, alfalfa-corn, and tillage (chisel plow-disk, no-till. The leachate data were used to evaluate a number of nitrate leaching models. Some of the highlights of the 11 years of results include the following: 1 growing corn without organic N inputs at the economic optimum N rate (EON resulted in NO3–-N concentrations of 15 to 20 mg l-1 in leachate; 2 use of manure or previous alfalfa crop as partial source of N also resulted in 15 to 20 mg l-1 of NO3–-N in leachate below corn at EON; 3 NO3–-N concentration in leachate below alfalfa was approximately 4 mg l-1; 4 NO3–-N concentration in leachate below soybeans following corn was influenced by fertilizer N rate applied to corn; 5 the mass of NO3–-N leached below corn at the EON rate averaged 90 kg N ha-1 (approx. 40% of fertilizer N applied at EON; 6 wick lysimeters collected approximately 100% of leachate vs. 40–50% collected by pan lysimeters. Coefficients of variation of the collected leachate volumes for both lysimeter types were similar; 7 tillage did not markedly affect nitrate leaching losses; 8 tested leaching models could accurately predict leachate volumes and could be calibrated to match nitrate leaching losses in calibration years, but only one model (SOILN accurately predicted nitrate leaching losses in the majority of validation treatment years. Apparent problems with tested models: there was difficulty estimating sizes of organic N pools and their transformation rates, and the models either did not include a macropore flow component or did not handle macropore flow well.

  13. The impact of different flooding periods on the dynamics of pore water concentrations of As, Cr, Mo and V in a contaminated floodplain soil - results of a lysimeter study

    Science.gov (United States)

    Rupp, Holger; Meissner, Ralph; Shaheen, Sabry; Rinklebe, Jörg

    2014-05-01

    Trace elements and arsenic (As) were transported with water during inundation in floodplain ecosystems, where they settled down and accumulated predominantly in depressions and low-lying terraces. Highly variable hydrological conditions in floodplains can affect the dynamics of pollutants. The impact of different flooding/drying periods on the temporal dynamics of pore water concentrations of As, Cr, Mo and V as a function of soil EH/pH changes and dynamics of DOC, Fe, Mn and SO42- was studied in a contaminated floodplain soil collected at the Elbe River (Germany). A specific groundwater lysimeter technique with two separate small lysimeter vessels served as replicates was used for this study. The groundwater level inside the lysimeters was controlled to simulate long term and short term flooding/drying. The long term (LT) flooding scenario consists of 94 days of flooding followed by similar drying term. The short term (ST) flooding/drying scenario comprises 21 days and was six times repeated. The entire experimental period (LT_ST) was about 450 days. Flooding of the soil caused a significant decrease of EH and pH. Concentrations of soluble As, Cr, Fe, Mn, Mo and DOC were higher under reducing conditions than under oxidizing conditions in LT. However, As and Cr tended to be mobilized under oxidizing conditions during ST, which might be due to slow kinetics of the redox reaction of As and Cr. Dynamics of Mo were more affected by changes of EH/pH as compared to As, Cr and V and governed mainly by Fe-Mn chemistry. Concentrations of V in ST were higher than in LT and were controlled particularly by pH and chemistry of Fe. The interactions between the elements and carriers studied were stronger during long flood-dry-cycles than during short cycles, which confirmed our hypothesis. We conclude that the dynamics of As, Cr, Mo and V are determined by the length of time soils are exposed to flooding, because drivers of element mobility need a certain time to provoke

  14. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30–70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below...

  15. Field study plan for alternate barriers

    International Nuclear Information System (INIS)

    Freeman, H.D.; Gee, G.W.; Relyea, J.F.

    1989-05-01

    Pacific Northwest Laboratory (PNL) is providing technical assistance in selecting, designing, evaluating, and demonstrating protective barriers. As part of this technical assistance effort, asphalt, clay, and chemical grout will be evaluated for use as alternate barriers. The purpose of the subsurface layer is to reduce the likelihood that extreme events (i.e., 100-year maximum storms, etc.) will cause significant drainage through the barrier. The tests on alternate barriers will include laboratory and field analysis of the subsurface layer performance. This field test plan outlines the activities required to test and design subsurface moisture barriers. The test plan covers activities completed in FY 1988 and planned through FY 1992 and includes a field-scale test of one or more of the alternate barriers to demonstrate full-scale application techniques and to provide performance data on a larger scale. Tests on asphalt, clay, and chemical grout were initiated in FY 1988 in small (30.5 cm diameter) tube-layer lysimeters. The parameters used for testing the materials were different for each one. The tests had to take into account the differences in material characteristics and response to change in conditions, as well as information provided by previous studies. 33 refs., 8 figs., 1 tab

  16. Distribuição da concentração de potássio no solo em lisímetros cultivados com amendoim Distribution of the potassium concentration in soil with lysimeters cultivated with peanut

    Directory of Open Access Journals (Sweden)

    Jarbas H Miranda

    2010-04-01

    Full Text Available A aplicação de fertilizantes na agricultura pode provocar uma dinâmica de solutos no solo abaixo da zona radicular, podendo, além de provocar prejuízos econômicos, contaminar águas subterrâneas. O presente trabalho teve como objetivo acompanhar o processo de deslocamento do íon potássio (K+ em lisímetros preenchidos com solo de textura arenosa e cultivado com amendoim (Arachis hypogaea L., sob diferentes condições de atenuação da densidade de fluxo radiante, como a utilização de filmes plásticos com diferentes espessuras (100 e 150 micras. O deslocamento do íon potássio (K+ foi monitorado por extratores de solução instalados em diferentes profundidades (15 e 25 cm, e o manejo da fertirrigação foi realizado com a utilização de tensiômetros. Concluiu-se que a baixa radiação solar incidente nos dois ambientes com coberturas plásticas afetou negativamente a produtividade do amendoim; o período em que o amendoim demanda maior quantidade de potássio ocorre dos 30 aos 55 dias após a semeadura; as plantas de amendoim não apresentaram deficiência nutricional com menor lixiviação de K+ para as camadas mais profundas do solo; nos lisímetros com cobertura plástica de 100 e 150 micras, ocorreu maior concentração de K+ na superfície do solo.The application of fertilizers in agriculture produce some solute displacement below the root zone and this situation has provoked great impacts, besides the economic damages, causing groundwater contamination. The present work has as the objective of monitoring the displacement process of the potassium (K+ in lysimeters filled with soil, sandy texture and cultivated with peanuts (Arachis hypogaea L. under different conditions of reducing solar radiation by using plastic films with different thickness (100 and 150 µ. The potassium displacement was monitored by soil solution extractors installed in different depths (15 and 25 cm and the fertigation management was accomplished by

  17. Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, S.H.; Andersen, Mathias Neumann; Lærke, Poul Erik

    2011-01-01

    Nitrogen (N) uptake (kg ha-1) of field-grown potatoes was measured in 4.32 m2 lysimeters that were filled with coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

  18. Lisímetro de pesagem de grande porte. parte II: consumo hídrico do coqueiro anão verde irrigado Large-scale weighing lysimeter. part II: water requirements of the irrigated dwarf-green coconut

    Directory of Open Access Journals (Sweden)

    Inajá F. Sousa

    2011-05-01

    Full Text Available Este trabalho, como segunda parte de uma pesquisa realizada no Estado de Sergipe, objetiva determinar a evapotranspiração e o coeficiente de cultura na fase de crescimento do coqueiro anão-verde (Cocos nucifera L., com base em medições lisimétricas e no modelo do balanço de energia, segundo a razão de Bowen. Obteve-se a evapotranspiração de referência pelo método de Penman-Monteith, na escala diária em todo o período experimental. O sistema de aquisição de dados foi programado para a automação da coleta de todos os sensores necessários à obtenção dos componentes do balanço de energia. O consumo hídrico do coqueiro durante a fase de crescimento é de 1.263,30 mm, com média diária de 3,90 mm d-1. O coeficiente de cultura nessa fase fenológica da palmeira varia entre 0,50 e 1,80, com média de 0,96.This paper, as Part II of a research carried out in Sergipe state, aims to determine evapotranspiration and crop coefficient of dwarf-green coconut (Cocos nucifera L. based on lysimeter measurements and Bowen ratio-energy balance method. The reference evapotranspiration was obtained by the Penman-Monteith approach on daily-scale during the experimental period. The data acquisition system was used to obtain all data from the sensors necessary to determine the energy balance components. The water requirements of coconut palm during the phenological growth stage is 1263.30 mm, with daily average of 3.90 mm d-1. The crop coefficient during this phenological growth stage varies between 0.50 and 1.80, with daily mean of 0.96.

  19. Modeling the effect of soil structure on water flow and isoproturon dynamics in an agricultural field receiving repeated urban waste compost application.

    Science.gov (United States)

    Filipović, Vilim; Coquet, Yves; Pot, Valérie; Houot, Sabine; Benoit, Pierre

    2014-11-15

    Transport processes in soils are strongly affected by heterogeneity of soil hydraulic properties. Tillage practices and compost amendments can modify soil structure and create heterogeneity at the local scale within agricultural fields. The long-term field experiment QualiAgro (INRA-Veolia partnership 1998-2013) explores the impact of heterogeneity in soil structure created by tillage practices and compost application on transport processes. A modeling study was performed to evaluate how the presence of heterogeneity due to soil tillage and compost application affects water flow and pesticide dynamics in soil during a long-term period. The study was done on a plot receiving a co-compost of green wastes and sewage sludge (SGW) applied once every 2 years since 1998. The plot was cultivated with a biannual rotation of winter wheat-maize (except 1 year of barley) and a four-furrow moldboard plow was used for tillage. In each plot, wick lysimeter outflow and TDR probe data were collected at different depths from 2004, while tensiometer measurements were also conducted during 2007/2008. Isoproturon concentration was measured in lysimeter outflow since 2004. Detailed profile description was used to locate different soil structures in the profile, which was then implemented in the HYDRUS-2D model. Four zones were identified in the plowed layer: compacted clods with no visible macropores (Δ), non-compacted soil with visible macroporosity (Γ), interfurrows created by moldboard plowing containing crop residues and applied compost (IF), and the plow pan (PP) created by plowing repeatedly to the same depth. Isoproturon retention and degradation parameters were estimated from laboratory batch sorption and incubation experiments, respectively, for each structure independently. Water retention parameters were estimated from pressure plate laboratory measurements and hydraulic conductivity parameters were obtained from field tension infiltrometer experiments. Soil hydraulic

  20. Overview of the Bushland Evapotranspiration and Agricultural Remote sensing EXperiment 2008 (BEAREX08): A field experiment evaluating methods for quantifying ET at multiple scales

    Science.gov (United States)

    Evett, Steven R.; Kustas, William P.; Gowda, Prasanna H.; Anderson, Martha C.; Prueger, John H.; Howell, Terry A.

    2012-12-01

    In 2008, scientists from seven federal and state institutions worked together to investigate temporal and spatial variations of evapotranspiration (ET) and surface energy balance in a semi-arid irrigated and dryland agricultural region of the Southern High Plains in the Texas Panhandle. This Bushland Evapotranspiration and Agricultural Remote sensing EXperiment 2008 (BEAREX08) involved determination of micrometeorological fluxes (surface energy balance) in four weighing lysimeter fields (each 4.7 ha) containing irrigated and dryland cotton and in nearby bare soil, wheat stubble and rangeland fields using nine eddy covariance stations, three large aperture scintillometers, and three Bowen ratio systems. In coordination with satellite overpasses, flux and remote sensing aircraft flew transects over the surrounding fields and region encompassing an area contributing fluxes from 10 to 30 km upwind of the USDA-ARS lysimeter site. Tethered balloon soundings were conducted over the irrigated fields to investigate the effect of advection on local boundary layer development. Local ET was measured using four large weighing lysimeters, while field scale estimates were made by soil water balance with a network of neutron probe profile water sites and from the stationary flux systems. Aircraft and satellite imagery were obtained at different spatial and temporal resolutions. Plot-scale experiments dealt with row orientation and crop height effects on spatial and temporal patterns of soil surface temperature, soil water content, soil heat flux, evaporation from soil in the interrow, plant transpiration and canopy and soil radiation fluxes. The BEAREX08 field experiment was unique in its assessment of ET fluxes over a broad range in spatial scales; comparing direct and indirect methods at local scales with remote sensing based methods and models using aircraft and satellite imagery at local to regional scales, and comparing mass balance-based ET ground truth with eddy covariance

  1. Re-evaluation of the sorption behaviour of Bromide and Sulfamethazine under field conditions using leaching data and modelling methods

    Science.gov (United States)

    Gassmann, Matthias; Olsson, Oliver; Höper, Heinrich; Hamscher, Gerd; Kümmerer, Klaus

    2016-04-01

    The simulation of reactive transport in the aquatic environment is hampered by the ambiguity of environmental fate process conceptualizations for a specific substance in the literature. Concepts are usually identified by experimental studies and inverse modelling under controlled lab conditions in order to reduce environmental uncertainties such as uncertain boundary conditions and input data. However, since environmental conditions affect substance behaviour, a re-evaluation might be necessary under environmental conditions which might, in turn, be affected by uncertainties. Using a combination of experimental data and simulations of the leaching behaviour of the veterinary antibiotic Sulfamethazine (SMZ; synonym: sulfadimidine) and the hydrological tracer Bromide (Br) in a field lysimeter, we re-evaluated the sorption concepts of both substances under uncertain field conditions. Sampling data of a field lysimeter experiment in which both substances were applied twice a year with manure and sampled at the bottom of two lysimeters during three subsequent years was used for model set-up and evaluation. The total amount of leached SMZ and Br were 22 μg and 129 mg, respectively. A reactive transport model was parameterized to the conditions of the two lysimeters filled with monoliths (depth 2 m, area 1 m²) of a sandy soil showing a low pH value under which Bromide is sorptive. We used different sorption concepts such as constant and organic-carbon dependent sorption coefficients and instantaneous and kinetic sorption equilibrium. Combining the sorption concepts resulted in four scenarios per substance with different equations for sorption equilibrium and sorption kinetics. The GLUE (Generalized Likelihood Uncertainty Estimation) method was applied to each scenario using parameter ranges found in experimental and modelling studies. The parameter spaces for each scenario were sampled using a Latin Hypercube method which was refined around local model efficiency maxima

  2. Die Grundlagen der Arithmetik. Eine logisch mathematische Untersuchung über den Begriff der Zahl

    OpenAIRE

    Frege, Gottlob

    1996-01-01

    Auf die Frage, was die Zahl Eins sei, oder was das Zeichen 1 bedeute, wird man meistens die Antwort erhalten: nun, ein Ding. Und wenn man dann darauf aufmerksam macht, dass der Satz "die Zahl Eins ist ein Ding" keine Definition ist, weil auf der einen Seite der bestimmte Artikel, auf der andern der unbestimmte steht, dass er nur besagt, die Zahl Eins gehöre zu den Dingen, aber nicht, welches Ding sie sei, so wird man vielleicht aufgefordert, sich irgendein Ding zu wählen, das man Eins nenn...

  3. Mathematische simulaties van flankbotsingen van personenauto's met fietsers : ontwikkeling van een bij dergelijke botsingen `ideaal' autofront.

    NARCIS (Netherlands)

    Sluis, J. van der & Kampen, L.T.B. van

    1992-01-01

    The Dutch Ministry of Transport has commissioned SWOV Institute for Road Safety Research to carry out a simulation study into side collisions of cars against bicyclists. The aim of the study is to obtain a description of an ideal car front in terms of shape and stiffness. An ideal car front will

  4. The war of frogs and mice, or the crisis of the Mathematische Annalen

    NARCIS (Netherlands)

    Dalen, D. van

    1987-01-01

    On 27 October 1928, a curious telegram was delivered to L.E.J. Brouwer, a telegram that was to plunge him into a con ict that for some months threatened to split the German mathematical community. This telegram set into motion a train of events that was to lead to the end of

  5. Ammonia volatilization losses from paddy fields under controlled irrigation with different drainage treatments.

    Science.gov (United States)

    He, Yupu; Yang, Shihong; Xu, Junzeng; Wang, Yijiang; Peng, Shizhang

    2014-01-01

    The effect of controlled drainage (CD) on ammonia volatilization (AV) losses from paddy fields under controlled irrigation (CI) was investigated by managing water table control levels using a lysimeter. Three drainage treatments were implemented, namely, controlled water table depth 1 (CWT1), controlled water table depth 2 (CWT2), and controlled water table depth 3 (CWT3). As the water table control levels increased, irrigation water volumes in the CI paddy fields decreased. AV losses from paddy fields reduced due to the increases in water table control levels. Seasonal AV losses from CWT1, CWT2, and CWT3 were 59.8, 56.7, and 53.0 kg N ha(-1), respectively. AV losses from CWT3 were 13.1% and 8.4% lower than those from CWT1 and CWT2, respectively. A significant difference in the seasonal AV losses was confirmed between CWT1 and CWT3. Less weekly AV losses followed by TF and PF were also observed as the water table control levels increased. The application of CD by increasing water table control levels to a suitable level could effectively reduce irrigation water volumes and AV losses from CI paddy fields. The combination of CI and CD may be a feasible water management method of reducing AV losses from paddy fields.

  6. Field study of wastes from fluidized-bed combustion technologies

    International Nuclear Information System (INIS)

    Weinberg, A.; Holcombe, L.; Butler, R.

    1991-01-01

    The Department of Energy (DOE) has undertaken a research project to monitor advanced coal process wastes placed in natural geologic settings. The overall objective of the study is to gather field data on the engineering and environmental performance of disposed solid waste from various advanced coal processes. The coal ash from a fluidized-bed combustion unit is being studied as part of the DOE program. The unit is a 110-MW circulating fluidized bed (CFB) at Colorado Ute Electric Association's Nucla Steam Electric Station, which is being demonstrated with the support of the DOE Clean Coal Technology Program. The Electric Power Research Institute is cofunding the study. In June of 1989, a test cell approximately 100 feet square and 8 feet deep was constructed and filled with ash from the Colorado Ute CFB unit. The cell was instrumented with lysimeters and neutron probe access tubes to monitor water flow and leachate chemistry in the ash; groundwater wells and runoff collection devices were installed to determine the effects on groundwater and surface water quality, and a meteorological station was installed to determine the water balance. Additionally, tests are being performed to evaluate the chemical, physical, and mineralogical properties of the solid waste and geologic materials. Results from the first year of monitoring are presented

  7. Field evidence for the potential of Rhodobacter capsulatus as Biofertilizer for flooded rice.

    Science.gov (United States)

    Gamal-Eldin, Hosny; Elbanna, Khaled

    2011-02-01

    In a previous study, we evaluated the effects of inoculating rice plants with the phototrophic purple nonsulfur bacterium Rhodobacter capsulatus (Rc) on growth and yield of rice in pots and lysimeter experiments and the results obtained have been highly encouraging. In this study, we carried out two field experiments: one in the experimental farm of the Faculty of Agriculture, Fayoum University, and the second in a farmer's field in Kafr El-sheikh, to assess the effects of Rc on growth and yield of rice in comparison and in combination with chemical nitrogen fertilizer (CNF) and farmyard manure. The results indicated that both biological and grain yields in all the Rc inoculated treatments were significantly higher than those in the uninoculated corresponding treatments in both fields. With regard to grain yield, the major factor for determining the effectiveness of any agricultural treatment, inoculation with Rc in combination with 50% of the recommended CNF rate gave a grain yield that was statistically equivalent to that obtained with 100% of the recommended CNF rate. These results provide a clear evidence for the potential of Rc as biofertilizer for flooded rice under field conditions.

  8. Field transformations to multivalued fields

    Energy Technology Data Exchange (ETDEWEB)

    Kleinert, H [Institut fuer Theoretische Physik, Arnimallee 14, D-14195 Berlin (Germany)

    2007-05-15

    Changes of field variables may lead to multivalued fields which do not satisfy the Schwarz integrability conditions. Their quantum field theory needs special care as is shown in an application to the superfluid and superconducting phase transitions.

  9. The fate of 15N-labelled organic nitrogen in sheep manure applied to soils of different texture under field conditions

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.; Nielsen, N.E.

    1994-01-01

    The fate of nitrogen from N-15-labelled sheep manure and ammonium sulfate in small lysimeters and plots in the field was studied during two growth seasons. In April 1991, N-15-labelled sheep faeces (87 kg N ha(-1)) plus unlabelled (NH4)(2)SO4 (90 kg N ha(-1)), and ((NH4)-N-15)(2)SO4 (90 kg N ha(-1......-17% of the labelled manure N and 56% of the labelled (NH4)(2)SO4-N. After 18 months 30% of the labelled manure N and 65% of the labelled (NH4)(2)SO4-N were accumulated in barley, the succeeding ryegrass crop and in leachate collected below 45 cm of soil, irrespective of the soil-sand mixture. Calculating the barley...

  10. Development and field testing of an alternative latrine design utilizing basic oxygen furnace slag as a treatment media for pathogen removal

    Science.gov (United States)

    Stimson, J.; Suhogusoff, A. V.; Blowes, D. W.; Hirata, R. A.; Ptacek, C. J.; Robertson, W. D.; Emelko, M. B.

    2009-05-01

    In densely-populated communities in developing countries, appropriate setback distances for pit latrines often cannot be met. An alternative latrine was designed that incorporates two permeable reactive media to treat pathogens and nitrate from effluent. Basic oxygen furnace (BOF) slag in contact with wastewater effluent elevates pH to levels (> 11) that inactivate pathogens. Saturated woodchip creates reducing conditions that encourage the growth of denitrifying bacteria which remove NO3-. The field application was constructed in Santo Antônio, a peri-urban community located 25 km south of the city of São Paulo, Brazil. A 2-m diameter pit was excavated to a depth of 4 m into the sandy-clay unsaturated zone. A geotextile liner was emplaced to create saturated conditions in the 0.5-m thick woodchip barrier. Above the woodchip barrier, a 1-m thick layer of BOF slag mixed with pea gravel and sand was emplaced. A series of filter layers, grading upward from coarse sand to fine gravel, where placed above the BOF layer, and gravel was also infilled around the outer perimeter of the excavation, to ensure O2 diffusion into the design, the formation of biofilm, and degradation of organic material. A control latrine, constructed with similar hydraulic characteristics and nonreactive materials, was constructed at a locality 100 m away, in the same geological materials. Total coliform, thermotolerant coliform, and E. coli are removed by approximately 4-5 log concentration units in less than one meter of vertical transport through the BOF slag media. In the control latrine, comparable reductions in these pathogenic indicators are observed over three meters of vertical transport. Removal of sulphur-reducing Clostridia, Clostridium perfrigens and somatic coliphage are also achieved in the alternative design, but initial concentrations in effluent are low. Some measurable concentrations of pathogen indicators are measured in lysimeters below the BOF layer, but are associated

  11. Coeficiente de cultura da lima-ácida tahiti no outono-inverno determinado por lisimetria de pesagem em Piracicaba - SP Crop coefficient of acid lime tahiti during autumn-winter period determined by weighing lysimeter technique in Piracicaba - SP, Brazil

    Directory of Open Access Journals (Sweden)

    Cícero R. A. Barboza Júnior

    2008-12-01

    Full Text Available O Brasil é o maior produtor mundial de citros, com destaque para o Estado de São Paulo, maior produtor nacional. Recentes estudos mostram que a área irrigada de citros em São Paulo tem aumentado significativamente nos últimos anos. Porém, a falta de informações sobre o manejo eficiente da irrigação na cultura de citros é uma das principais dificuldades enfrentadas pelos produtores. Com o intuito de atender a essa necessidade, este trabalho teve como objetivos determinar a evapotranspiração de uma planta adulta de limeira-ácida 'Tahiti' (Citrus latifolia Tan. e o coeficiente de cultivo (Kc no período seco (outono-inverno, utilizando a técnica de lisimetria de pesagem. O experimento foi realizado na ESALQ/USP em Piracicaba - SP, em área irrigada por gotejamento, com plantas espaçadas de 7 x 4 m, sendo cada planta atendida por quatro pontos de molhamento no solo, distribuídos de forma equidistantes entre si. Foi realizado o monitoramento climático, utilizando estação meteorológica automatizada, e a determinação da evapotranspiração da cultura por lisímetro de pesagem. Durante o período de estudo, o Kc variou entre 0,82 e 1,18, e a ETc variou entre 1,2 e 5,6.Brazil is the largest world producer of citrus crop, with São Paulo state leading as the largest national producer. Recent studies show that irrigated areas of citrus in the state have been increasing significantly in the last few years. However, lack of information on irrigation management related to this crop is one of the main problems encountered by the farmers. In order to help solve the above problem, the objective of this work was to determine the evapotranspiration of acid lime adult plant variety 'Tahiti' (Citrus latifolia Tan. and the crop coefficient during dry period (autumn - winter using a weighing lysimeter technique. The experiment was carried out at ESALQ/USP in Piracicaba - SP, Brazil, in a drip irrigated area with plant spacing of 7 x 4 m. Each

  12. Visual field

    Science.gov (United States)

    ... your visual field. How the Test is Performed Confrontation visual field exam. This is a quick and ... to achieve this important distinction for online health information and services. Learn more about A.D.A. ...

  13. Physical transformations of iron oxide and silver nanoparticles from an intermediate scale field transport study

    Science.gov (United States)

    Emerson, Hilary P.; Hart, Ashley E.; Baldwin, Jonathon A.; Waterhouse, Tyler C.; Kitchens, Christopher L.; Mefford, O. Thompson; Powell, Brian A.

    2014-02-01

    In recent years, there has been increasing concern regarding the fate and transport of engineered nanoparticles (NPs) in environmental systems and the potential impacts on human and environmental health due to the exponential increase in commercial and industrial use worldwide. To date, there have been relatively few field-scale studies or laboratory-based studies on environmentally relevant soils examining the chemical/physical behavior of the NPs following release into natural systems. The objective of this research is to demonstrate the behavior and transformations of iron oxide and silver NPs with different capping ligands within the unsaturated zone. Here, we show that NP transport within the vadose zone is minimal primarily due to heteroaggregation with soil surface coatings with results that >99 % of the NPs remained within 5 cm of the original source after 1 year in intermediate-scale field lysimeters. These results suggest that transport may be overestimated when compared to previous laboratory-scale studies on pristine soils and pure minerals and that future work must incorporate more environmentally relevant parameters.

  14. Magnetic Field

    DEFF Research Database (Denmark)

    Olsen, Nils

    2015-01-01

    he Earth has a large and complicated magnetic field, the major part of which is produced by a self-sustaining dynamo operating in the fluid outer core. Magnetic field observations provide one of the few tools for remote sensing the Earth’s deep interior, especially regarding the dynamics...... of the fluid flow at the top of the core. However, what is measured at or near the surface of the Earth is the superposition of the core field and fields caused by magnetized rocks in the Earth’s crust, by electric currents flowing in the ionosphere, magnetosphere, and oceans, and by currents induced...... in the Earth by time-varying external fields. These sources have their specific characteristics in terms of spatial and temporal variations, and their proper separation, based on magnetic measurements, is a major challenge. Such a separation is a prerequisite for remote sensing by means of magnetic field...

  15. Phase field

    International Nuclear Information System (INIS)

    Radhakrishnan, B.; Gorti, S.B.; Clarno, K.; Tonks, M.R.

    2015-01-01

    In this work, the phase-field method and its application to microstructure evolution in reactor fuel and clad are discussed. The examples highlight the capability of the phase-field method to capture evolution processes that are influenced by both thermal and elastic stress fields that are caused by microstructural changes in the solid-state. The challenges that need to be overcome before the technique can become predictive and material-specific are discussed. (authors)

  16. Field Report

    DEFF Research Database (Denmark)

    Gorm Hansen, Louise Lyngfeldt

    2012-01-01

    This field report expresses perfectly the kind of confusion almost all of us experience when entering the field. How do we know whether what we’re doing is “right” or not? What in particular should we record when we don’t have time to write down everything among all the myriad impressions thrusting...

  17. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Andersen, Mathias Neumann; Plauborg, Finn

    2010-01-01

    Yield and water productivity of potatoes grown in 4.32 m2 lysimeters were measured in coarse sand, loamy sand, and sandy loam and imposed to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI after...

  18. Unsaturated flow dynamics during irrigation with wastewater: field and modelling study

    Science.gov (United States)

    Martinez-Hernandez, V.; de Miguel, A.; Meffe, R.; Leal, M.; González-Naranjo, V.; de Bustamante, I.

    2012-04-01

    . Data from the lysimeter and soil moisture probes were used to calibrate the model. The overall simulation time period included the dry (irrigation as main source of water) and the wet season (precipitation as main source of water). Future investigation concerning groundwater affections and contaminant transport at the field site will be based on the results obtained through the flow model developed in this study.

  19. Field Notes

    Data.gov (United States)

    US Agency for International Development — This is a mobile application for capturing images , data, and geolocation for USAID projects in the field. The data is then stored on a server in AllNet. The...

  20. Selfdecomposable Fields

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Sauri, Orimar; Szozda, Benedykt

    In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master Lévy measure and the associated Lévy-Itô representation. We give the dilation criterion for selfdecomposa......In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master Lévy measure and the associated Lévy-Itô representation. We give the dilation criterion...... for selfdecomposability analogous to the classical one. Next, we give necessary and sufficient conditions (in terms of the kernel functions) for a Volterra field driven by a Lévy basis to be selfdecomposable. In this context we also study the so-called Urbanik classes of random fields. We follow this with the study...... of existence and selfdecomposability of integrated Volterra fields. Finally, we introduce infinitely divisible field-valued Lévy processes, give the Lévy-Itô representation associated with them and study stochastic integration with respect to such processes. We provide examples in the form of Lévy...

  1. Selfdecomposable Fields

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Sauri, Orimar; Szozda, Benedykt

    In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master L\\'evy measure and the associated L\\'evy-It\\^o representation. We give the dilation criterion for selfdec......In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master L\\'evy measure and the associated L\\'evy-It\\^o representation. We give the dilation criterion...... for selfdecomposability analogous to the classical one. Next, we give necessary and sufficient conditions (in terms of the kernel functions) for a Volterra field driven by a L\\'evy basis to be selfdecomposable. In this context we also study the so-called Urbanik classes of random fields. We follow this with the study...... of existence and selfdecomposability of integrated Volterra fields. Finally, we introduce infinitely divisible field-valued L\\'evy processes, give the L\\'evy-It\\^o representation associated with them and study stochastic integration with respect to such processes. We provide examples in the form of L...

  2. Random Fields

    Science.gov (United States)

    Vanmarcke, Erik

    1983-03-01

    Random variation over space and time is one of the few attributes that might safely be predicted as characterizing almost any given complex system. Random fields or "distributed disorder systems" confront astronomers, physicists, geologists, meteorologists, biologists, and other natural scientists. They appear in the artifacts developed by electrical, mechanical, civil, and other engineers. They even underlie the processes of social and economic change. The purpose of this book is to bring together existing and new methodologies of random field theory and indicate how they can be applied to these diverse areas where a "deterministic treatment is inefficient and conventional statistics insufficient." Many new results and methods are included. After outlining the extent and characteristics of the random field approach, the book reviews the classical theory of multidimensional random processes and introduces basic probability concepts and methods in the random field context. It next gives a concise amount of the second-order analysis of homogeneous random fields, in both the space-time domain and the wave number-frequency domain. This is followed by a chapter on spectral moments and related measures of disorder and on level excursions and extremes of Gaussian and related random fields. After developing a new framework of analysis based on local averages of one-, two-, and n-dimensional processes, the book concludes with a chapter discussing ramifications in the important areas of estimation, prediction, and control. The mathematical prerequisite has been held to basic college-level calculus.

  3. Design and Installation of a Disposal Cell Cover Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Benson, C.H. [University of Wisconsin–Madison, Madison, Wisconsin; Waugh, W.J. [S.M. Stoller Corporation, Grand Junction, Colorado; Albright, W.H. [Desert Research Institute, Reno, Nevada; Smith, G.M. [Geo-Smith Engineering, Grand Junction, Colorado; Bush, R.P. [U.S. Department of Energy, Grand Junction, Colorado

    2011-02-27

    The U.S. Department of Energy’s Office of Legacy Management (LM) initiated a cover assessment project in September 2007 to evaluate an inexpensive approach to enhancing the hydrological performance of final covers for disposal cells. The objective is to accelerate and enhance natural processes that are transforming existing conventional covers, which rely on low-conductivity earthen barriers, into water balance covers, that store water in soil and release it as soil evaporation and plant transpiration. A low conductivity cover could be modified by deliberately blending the upper layers of the cover profile and planting native shrubs. A test facility was constructed at the Grand Junction, Colorado, Disposal Site to evaluate the proposed methodology. The test cover was constructed in two identical sections, each including a large drainage lysimeter. The test cover was constructed with the same design and using the same materials as the existing disposal cell in order to allow for a direct comparison of performance. One test section will be renovated using the proposed method; the other is a control. LM is using the lysimeters to evaluate the effectiveness of the renovation treatment by monitoring hydrologic conditions within the cover profile as well as all water entering and leaving the system. This paper describes the historical experience of final covers employing earthen barrier layers, the design and operation of the lysimeter test facility, testing conducted to characterize the as-built engineering and edaphic properties of the lysimeter soils, the calibration of instruments installed at the test facility, and monitoring data collected since the lysimeters were constructed.

  4. Field theories with subcanonical fields

    International Nuclear Information System (INIS)

    Bigi, I.I.Y.

    1976-01-01

    The properties of quantum field theories with spinor fields of dimension less than the canonical value of 3/2 are studied. As a starting point for the application of common perturbation theory we look for the linear version of these theories. A gange-interaction is introduced and with the aid of power counting the renormalizability of the theory is shown. It follows that in the case of a spinor-field with negative dimension renormalization can only be attained if the interaction has a further symmetry. By this symmetry the theory is determined in an unequivocal way. The gange-interaction introduced in the theory leads to a spontaneous breakdown of scale invariance whereby masses are produced. At the same time the spinor-field operators can now be separated in two orthogonal sections with opposite norm. It is proposed to use the section with negative (positive) norm to describe hadrons (leptons) respectively. (orig./WL) [de

  5. Subsurface transport of inorganic and organic solutes from experimental road spreading of oil-field brine

    International Nuclear Information System (INIS)

    Bair, E.S.; Digel, R.K.

    1990-01-01

    A study designed to evaluate ground water quality changes resulting from spreading oil-field brine on roads for ice and dust control was conducted using a gravel roadbed that received weekly applications of brine eight times during the winter phase and 11 times during the summer phase of the study. A network of 11 monitoring wells and five pressure-vacuum lysimeters was installed to obtain ground water and soil water samples. Thirteen sets of water-quality samples were collected and analyzed for major ions, trace metals, and volatile organic compounds. Two sets of samples were taken prior to brine spreading, four sets during winter-phase spreading, five sets during summer-phase spreading, and two sets during the interim between the winter and summer phases. A brine plume delineated by elevated specific-conductance values and elevated chloride concentrations in ground water samples to exceed US EPA public drinking-water standards by two-fold during the winter phase and five-fold during the summer phase. No other major ions, trace metals, or volatile organic compounds exceeded the standards during the winter or summer phases. More than 99% dilution of the solutes in the brine occurred between the roadbed surface and the local ground water flow system. Further attenuation of calcium, sodium, potassium, and strontium resulted from adsorption, whereas further attenuation of benzene resulted from volatilization and adsorption

  6. Monitoring soil moisture dynamics via ground-penetrating radar survey of agriculture fields after irrigation

    Science.gov (United States)

    Muro, G.

    2015-12-01

    It is possible to examine the quality of ground-penetrating radar (GPR) as a measure of soil moisture content in the shallow vadose zone, where roots are most abundant and water conservation best management practices are critical in active agricultural fields. By analyzing temporal samplings of 100 Mhz reflection profiles and common-midpoint (CMP) soundings over a full growing season, the variability of vertical soil moisture distribution directly after irrigation events are characterized throughout the lifecycle of a production crop. Reflection profiles produce high-resolution travel time data and summed results of CMP sounding data provide sampling depth estimates for the weak, but coherent reflections amid strong point scatterers. The high ratio of clay in the soil limits the resolution of downward propagation of infiltrating moisture after irrigation; synthetic data analysis compared against soil moisture lysimeter logs throughout the profile allow identification of the discrete soil moisture content variation in the measured GPR data. The nature of short duration irrigation events, evapotranspiration, and drainage behavior in relation to root depths observed in the GPR temporal data allow further examination and comparison with the variable saturation model HYDRUS-1D. After retrieving soil hydraulic properties derived from laboratory measured soil samples and simplified assumptions about boundary conditions, the project aims to achieve good agreement between simulated and measured soil moisture profiles without the need for excessive model calibration for GPR-derived soil moisture estimates in an agricultural setting.

  7. Controlled field release of a bioluminescent genetically engineered microorganism for bioremediation process monitoring and control

    Energy Technology Data Exchange (ETDEWEB)

    Ripp, S.; Nivens, D.E.; Ahn, Y.; Werner, C.; Jarrell, J. IV; Easter, J.P.; Cox, C.D.; Burlage, R.S.; Sayler, G.S.

    2000-03-01

    Pseudomonas fluorescens HK44 represents the first genetically engineered microorganism approved for field testing in the United States for bioremediation purposes. Strain HK44 harbors an introduced lux gene fused within a naphthalene degradative pathway, thereby allowing this recombinant microbe to bioluminescent as it degrades specific polyaromatic hydrocarbons such as naphthalene. The bioremediation process can therefore be monitored by the detection of light. P. fluorescens HK44 was inoculated into the vadose zone of intermediate-scale, semicontained soil lysimeters contaminated with naphthalene, anthracene, and phenanthrene, and the population dynamics were followed over an approximate 2-year period in order to assess the long-term efficacy of using strain HK44 for monitoring and controlling bioremediation processes. Results showed that P. fluorescens HK44 was capable of surviving initial inoculation into both hydrocarbon contaminated and uncontaminated soils and was recoverable from these soils 660 days post inoculation. It was also demonstrated that strain HK44 was capable of generating bioluminescence in response to soil hydrocarbon bioavailability. Bioluminescence approaching 166,000 counts/s was detected in fiber optic-based biosensor devices responding to volatile polyaromatic hydrocarbons, while a portable photomultiplier module detected bioluminescence at an average of 4300 counts/s directly from soil-borne HK44 cells within localized treatment areas. The utilization of lux-based bioreporter microorganisms therefore promises to be a viable option for in situ determination of environmental contaminant bioavailability and biodegradation process monitoring and control.

  8. Gauge fields

    International Nuclear Information System (INIS)

    Itzykson, C.

    1978-01-01

    In these notes the author provides some background on the theory of gauge fields, a subject of increasing popularity among particle physicists (and others). Detailed motivations and applications which are covered in the other lectures of this school are not presented. In particular the application to weak interactions is omitted by referring to the introduction given by J. Ilipoulos a year ago (CERN Report 76-11). The aim is rather to stress those aspects which suggest that gauge fields may play some role in a future theory of strong interactions. (Auth.)

  9. Rice evapotranspiration at the field and canopy scales under water-saving irrigation

    Science.gov (United States)

    Liu, Xiaoyin; Xu, Junzeng; Yang, Shihong; Zhang, Jiangang

    2018-04-01

    Evapotranspiration (ET) is an important process of land surface water and thermal cycling, with large temporal and spatial variability. To reveal the effect of water-saving irrigation (WSI) on rice ET at different spatial scales and understand the cross spatial scale difference, rice ET under WSI condition at canopy (ETCML) and field scale (ETEC) were measured simultaneously by mini-lysimeter and eddy covariance (EC) in the rice season of 2014. To overcome the shortage of energy balance deficit by EC system, and evaluate the influence of energy balance closure degree on ETEC, ETEC was corrected as {ET}_{EC}^{*} by energy balance closure correction according to the evaporative fraction. Seasonal average daily ETEC, {ET}_{EC}^{*} and ETCML of rice under WSI practice were estimated as 3.12, 4.03 and 4.35 mm day-1, smaller than the values reported in flooded paddy fields. Daily ETEC, {ET}_{EC}^{*} and ETCML varied in a similar trends and reached the maximum in late tillering, then decreased along with the crop growth in late season. The value of ETEC was much lower than ETCML, and was frequently 1-2 h lagged behind ETCML. It indicated that the energy balance deficit resulted in underestimation of crop ET by EC system. The corrected value of {ET}_{EC}^{*} matched ETCML much better than ETEC, with a smaller RMSE (0.086 mm h-1) and higher R 2 (0.843) and IOA (0.961). The time lapse between {ET}_{EC}^{*} and ETCML was mostly shortened to less than 0.5 h. The multiple stepwise regression analysis indicated that net radiation ( R n) is the dominant factor for rice ET, and soil moisture ( θ) is another significant factor ( p rice fields. The difference between ETCML and {ET}_{EC}^{*} ({ET}_{CML} - {ET}_{EC}^{*}) were significantly ( p rice ET in WSI fields, and for its cross scale conversion.

  10. Field theory

    CERN Multimedia

    1999-11-08

    In these lectures I will build up the concept of field theory using the language of Feynman diagrams. As a starting point, field theory in zero spacetime dimensions is used as a vehicle to develop all the necessary techniques: path integral, Feynman diagrams, Schwinger-Dyson equations, asymptotic series, effective action, renormalization etc. The theory is then extended to more dimensions, with emphasis on the combinatorial aspects of the diagrams rather than their particular mathematical structure. The concept of unitarity is used to, finally, arrive at the various Feynman rules in an actual, four-dimensional theory. The concept of gauge-invariance is developed, and the structure of a non-abelian gauge theory is discussed, again on the level of Feynman diagrams and Feynman rules.

  11. The 1996 thaw as a {sup 18}O tracer experiment at the lysimeter plant in Wagna; Die Schneeschmelze 1996 als {sup 18}O-Tracerversuch an der Lysimeteranlage in Wagna

    Energy Technology Data Exchange (ETDEWEB)

    Fank, J.; Zojer, H. [Forschungsgesellschaft Joanneum, Graz (Austria). Inst. fuer Geothermie und Hydrogeologie; Stichler, W. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie

    1999-02-01

    In the year 1991 a research site was set up in Wagna in the western Leibnitz Field (Styria) which permits an examination of seepage water movement and of material transport as a function of the permeability of the uppermost soil layers and the underlying more coarsly clastic sediments under locale-specific natural management systems. Research at this site is largely based on hydrochemical and isotope-hydrological analysis. The {sup 18}O isotope is an ideal natural tracer of water movement. Infiltration water from the thaw following a snowy winter was displaced downward into the unsaturated zone as a result of a major precipitation event of 85.5 mm from April 2 to 5, 1996. This displacement is evident in the {sup 18}O concentrations of the seepage water at various measuring depths. The displacement is associated with recharge events, thaw processes tending to produce dispersive flows and precipitation events leading to ``piston flow effects. Winter precipitation water reaches a depth of 60 to 70 cm by mid-April. The attenuated {sup 18}O concentration reveals the predominant flow characteristics in the different compartments of the unsaturated zone (finely clastic soils, gravels, and sands). [Deutsch] Im Jahre 1991 wurde in Wagna, im westlichen Leibnitzer Feld (Steiermark), eine Forschungsstation errichtet, die es erlaubt, unter ortsueblichen, natuerlichen Bewirtschaftungssystemen die Sickerwasserbewegung und den Transport von Stoffen in Abhaengigkeit von der Durchlaessigkeit der obersten Bodenschichten und der darunter folgenden groeberklastischen Sedimente vor allem auf Grundlage der hydrochemischen und isotopenhydrologischen Analytik zu untesuchen. Die Verwendung des {sup 18}O-Isotops als natuerlicher Tracer repraesentiert in idealer Weise die Bewegung des Wassers. Infiltrationswasser aus der Schneeschmelze nach einem schneereichen Winter wurde durch ein starkes Niederschlagsereignis von 85.6 mm zwischen 2. und 5. April 1996 in der ungesaettigten Zone

  12. Field test facility for monitoring water/radionuclide transport through partially saturated geologic media: design, construction, and preliminary description. Appendix I. Engineering drawings

    International Nuclear Information System (INIS)

    Phillips, S.J.; Campbell, A.C.; Campbell, M.D.; Gee, G.W.; Hoober, H.H.; Schwarzmiller, K.O.

    1979-11-01

    The engineering plans for a test facility to monitor radionuclide transport in water through partially saturated geological media are included. Drawings for the experimental set-up excavation plan and details, lysimeter, pad, access caisson, and caisson details are presented

  13. Gauge fields

    International Nuclear Information System (INIS)

    Mills, R.

    1989-01-01

    This article is a survey of the history and ideas of gauge theory. Described here are the gradual emergence of symmetry as a driving force in the shaping of physical theory; the elevation of Noether's theorem, relating symmetries to conservation laws, to a fundamental principle of nature; and the force of the idea (''the gauge principle'') that the symmetries of nature, like the interactions themselves, should be local in character. The fundamental role of gauge fields in mediating the interactions of physics springs from Noether's theorem and the gauge principle in a remarkably clean and elegant way, leaving, however, some tantalizing loose ends that might prove to be the clue to a future deeper level of understanding. The example of the electromagnetic field as the prototype gauge theory is discussed in some detail and serves as the basis for examining the similarities and differences that emerge in generalizing to non-Abelian gauge theories. The article concludes with a brief examination of the dream of total unification: all the forces of nature in a single unified gauge theory, with the differences among the forces due to the specific way in which the fundamental symmetries are broken in the local environment

  14. Field training

    International Nuclear Information System (INIS)

    Mumford, G.E.; Hadaway, E.H.

    1991-01-01

    Individualized, personal training can be used to increase an employee's awareness of the HSE program. Such training can stimulate personal commitment and provide personal skills that can be utilized for the benefit of the overall HSE effort. But, providing such training within our industry can be a difficult task due to the scheduling, travel arrangements, and cost associated with bringing employees from isolated, remote locations to centrally located training facilities. One method of overcoming these obstacles involves the use of field instructors to provide the training at the many, and varied number of individuals can be reached with minimal disruption to their work scheduling or to their time off. In fact, this type of on-site training is already used by some oil companies and drilling contractors with encouraging results. This paper describes one drilling contractor's experiences with such a training program. The results after eight years how that this program not only can provide and efficient, economical means of employee training, but also can have a direct application to employee motivation regarding a company's HSE effort

  15. Field and laboratory evaluation of the mobility of cobalt-60/EDTA in an arid environment

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Swanson, J.L.; Kirkham, R.R.

    1983-02-01

    The ability of the organic complexant EDTA to enhance the mobility of cobalt-60 was investigated in both laboratory and field experiments. Laboratory tests consisted of short term (approximately 7 day) column and batch adsorption tests using soil from the Hanford site as well as long term (approximately 70 day) batch tests with Hanford soil and soils from Oak Ridge and Savannah River. In addition, two large scale tracer tests were conducted using Hanford soil. One used a large (1.6 m) laboratory column, spiked with cobalt-60/EDTA and the other was a field test conducted in an 8 m deep lysimeter. Enhanced mobility decreased sorption were observed in both column and batch tests when the cobalt-60/EDTA solutions contacted Hanford and Oak Ridge soil for only a few days. When long contact times were allowed (months) the Hanford soil showed large increases in sorption with time. The low sorption exhibited initially by the Oak Ridge soil increased slightly over time, however, the high sorption observed with the Savannah River soil remained constant with time. The reduced mobility, with time, observed in Hanford soils was confirmed in both the large scale laboratory and breaking down when contacted with Hanford and Savannah River soil and to a lesser extent, the Oak Ridge soil. It is not known at this time why the complex is breaking down or why the kinetics are different among the soils tested. The implication to waste management is that the potential for transport of cobalt by EDTA complexation may not be as serious as once thought

  16. Simple weighing lysimeters for measuring reference and crop evapotranspiration

    Science.gov (United States)

    Knowledge of cotton crop evapotranspiration is important in scheduling irrigations, optimizing crop production, and modeling evapotranspiration and crop growth. The ability to measure, estimate, and predict evapotranspiration and cotton crop water requirements can result in better satisfying the cr...

  17. Predictive hydrogeochemical modelling of bauxite residue sand in field conditions.

    Science.gov (United States)

    Wissmeier, Laurin; Barry, David A; Phillips, Ian R

    2011-07-15

    The suitability of residue sand (the coarse fraction remaining from Bayer's process of bauxite refining) for constructing the surface cover of closed bauxite residue storage areas was investigated. Specifically, its properties as a medium for plant growth are of interest to ensure residue sand can support a sustainable ecosystem following site closure. The geochemical evolution of the residue sand under field conditions, its plant nutrient status and soil moisture retention were studied by integrated modelling of geochemical and hydrological processes. For the parameterization of mineral reactions, amounts and reaction kinetics of the mineral phases natron, calcite, tricalcium aluminate, sodalite, muscovite and analcime were derived from measured acid neutralization curves. The effective exchange capacity for ion adsorption was measured using three independent exchange methods. The geochemical model, which accounts for mineral reactions, cation exchange and activity corrected solution speciation, was formulated in the geochemical modelling framework PHREEQC, and partially validated in a saturated-flow column experiment. For the integration of variably saturated flow with multi-component solute transport in heterogeneous 2D domains, a coupling of PHREEQC with the multi-purpose finite-element solver COMSOL was established. The integrated hydrogeochemical model was applied to predict water availability and quality in a vertical flow lysimeter and a cover design for a storage facility using measured time series of rainfall and evaporation from southwest Western Australia. In both scenarios the sand was fertigated and gypsum-amended. Results show poor long-term retention of fertilizer ions and buffering of the pH around 10 for more than 5 y of leaching. It was concluded that fertigation, gypsum amendment and rainfall leaching alone were insufficient to render the geochemical conditions of residue sand suitable for optimal plant growth within the given timeframe. The

  18. An electric field in a gravitational field

    International Nuclear Information System (INIS)

    Harpaz, Amos

    2005-01-01

    The behaviour of an electric field in a gravitational field is analysed. It is found that due to the mass (energy) of the electric field, it is subjected to gravity and it falls in the gravitational field. This fall curves the electric field, a stress force (a reaction force) is created, and the interaction of this reaction force with the static charge gives rise to the creation of radiation

  19. Ammonia volatilization from a paddy field following applications of urea: rice plants are both an absorber and an emitter for atmospheric ammonia.

    Science.gov (United States)

    Hayashi, Kentaro; Nishimura, Seiichi; Yagi, Kazuyuki

    2008-02-15

    Ammonia (NH(3)) volatilization from a paddy field following applications of urea was measured. Two lysimeters of Gray Lowland soil with a pH (H(2)O) of 5.7 were used for the experiment. Urea was applied at a rate of 50 kg N ha(-1) by incorporation as the basal fertilization (BF) and at rates of 30 and 10 kg N ha(-1) by top-dressing as the first (SF1) and second (SF2) supplemental fertilizations, respectively. Two wind tunnels per lysimeter were installed just after BF; one was transplanted with rice plants (PR plot), and the other was without rice plants (NR plot). Weak volatilization was observed at the PR plots after BF. By contrast, strong volatilization was observed at the PR plots after SF1 with a maximum flux of 150 g N ha(-1) h(-1); however, almost no volatilization was observed after SF2. The NH(3) volatilization loss accounted for 2.1%, 20.9%, 0.5%, and 8.2% of the applied urea at each application, BF, SF1, SF2, and the total application, respectively, for which only the net fluxes as volatilization were accumulated. The NH(3) volatilization fluxes from the paddy water surface (F(vol)) at the NR plots were estimated using a film model for its verification. After confirmation of good correlation, the film model was applied to estimate F(vol) at the PR plots. The NH(3) exchange fluxes by rice plants (F(ric)) were obtained by subtracting F(vol) from the observed net NH(3) flux. The derived F(ric) showed that the rice plants emitted NH(3) remarkably just after SF1 when a relatively high rate of urea was applied, although they absorbed atmospheric NH(3) in the other periods. In conclusion, rice plants are essentially an absorber of atmospheric NH(3); however, they turn into an emitter of NH(3) under excess nutrition of ammoniacal nitrogen.

  20. Soil nitrogen balance under wastewater management: Field measurements and simulation results

    Science.gov (United States)

    Sophocleous, M.; Townsend, M.A.; Vocasek, F.; Ma, Liwang; KC, A.

    2009-01-01

    The use of treated wastewater for irrigation of crops could result in high nitrate-nitrogen (NO3-N) concentrations in the vadose zone and ground water. The goal of this 2-yr field-monitoring study in the deep silty clay loam soils south of Dodge City, Kansas, was to assess how and under what circumstances N from the secondary-treated, wastewater-irrigated corn reached the deep (20-45 m) water table of the underlying High Plains aquifer and what could be done to minimize this problem. We collected 15.2-m-deep soil cores for characterization of physical and chemical properties; installed neutron probe access tubes to measure soil-water content and suction lysimeters to sample soil water periodically; sampled monitoring, irrigation, and domestic wells in the area; and obtained climatic, crop, irrigation, and N application rate records for two wastewater-irrigated study sites. These data and additional information were used to run the Root Zone Water Quality Model to identify key parameters and processes that influence N losses in the study area. We demonstrated that NO3-N transport processes result in significant accumulations of N in the vadose zone and that NO3-N in the underlying ground water is increasing with time. Root Zone Water Quality Model simulations for two wastewater-irrigated study sites indicated that reducing levels of corn N fertilization by more than half to 170 kg ha-1 substantially increases N-use efficiency and achieves near-maximum crop yield. Combining such measures with a crop rotation that includes alfalfa should further reduce the accumulation and downward movement of NO3-N in the soil profile. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  1. Leaching of 14-Carbofuran into sub-surface water in vegetable agroecosystem

    International Nuclear Information System (INIS)

    Nashriyah Mat; Misman Sumin; Maizatul Akmam Mohd Nasir; Kubiak, R.

    2000-01-01

    An experimental setup was constructed to investigate leaching of 14C C arbofuran into sub-surface water through Bungor series sandy loam soil. The indoor lysimeter was constructed using homogenous and packed disturbed soil column. The outdoor lysimeter was constructed using undisturbed soil column. In the field, leachate production was influenced by rainfall intensity but tracer transport was independent of water transport to a certain degree. A high rainfall intensity at 39 DAA has not enhanced tracer leaching into sub-surface water in vegetable agroecosystem whereas a lower rainfall intensity at 21 DAA has enhanced its leaching. Indoor lysimeter behaved incoherently and showed non-parallel relationship between applied water and also volume of leachate produced with tracer transport. In both types of lysimeter, tracer transport and carbofuran transport generally correlated. Carbofuran and tracer were leached at a lower magnitude in outdoor lysimeter compared to the indoor lysimeter. The maximum total radioactivities leached were 1.1% and 0.4% of applied radio activities from indoor lysimeter and outdoor lysimeter at 35 and 21 DAA respectively. The maximum total carbofuran equivalent leached were 193.9 μg/L and 39.3 μg/L at 35 DAA and 21 DAA from indoor lysimeter and outdoor lysimeter respectively. (author)

  2. 11-year field study of Pu migration from Pu III, IV, and VI sources

    International Nuclear Information System (INIS)

    Kaplan, D.I.; Serkiz, S.M.; Demirkanli, D.I.; Gumapas, L.; Fjeld, R.A.; Molz, F.J.; Powell, B.A.

    2005-01-01

    Full text of publication follows: Understanding the processes controlling Pu mobility in the subsurface environment is important for estimating the amount of Pu waste that can be safely disposed in vadose zone burial sites. To study long-term Pu mobility, four 52-L lysimeters filled with sediment collected from the Savannah River Site near Aiken South Carolina were amended with well characterized solid Pu sources (Pu III Cl 3 , Pu IV (NO 3 ) 4 , Pu IV (C 2 O 4 ) 2 , and Pu VI O 2 (NO 3 ) 2 ) and left exposed to natural precipitation for 2 to 11 years. Pu oxidation state distribution in the Pu(III) and Pu(IV) lysimeters sediments (a red clayey sediment, pH = 6.3) were similar, consisting of 0% Pu(III), >92% Pu(IV), 1% Pu(V), 1% Pu(VI), and the remainder was a Pu polymer. These three lysimeters also had near identical sediment Pu concentration profiles, where >95% of the Pu remained within 1.25 cm of the source after 11 years; moving at an overall rate of 0.9 cm yr -1 . As expected, Pu moved more rapidly through the Pu(VI) lysimeter, at an overall rate of 12.5 cm yr -1 . Solute transport modeling of the sediment Pu concentration profile data in the Pu(VI) lysimeter indicated that some transformation of Pu into a much less mobile form, presumably Pu(IV), had occurred during the course of the two year study. This modeling also supported previous laboratory measurements showing that Pu(V) or Pu(VI) reduction was five orders of magnitude faster than corresponding Pu(III) or Pu(IV) oxidation. The slow oxidation rate (1 x 10-8 hr -1 ; t 1/2 = 8,000 yr) was not discernable from the Pu(VI) lysimeter data that reflected only two years of transport but was readily discernable from the Pu(III) and Pu(IV) lysimeter data that reflected 11 yr of transport. (authors)

  3. Effect of nitrogen and water availability of three soil types on yield, radiation use efficiency and evapotranspiration in field-grown quinoa

    DEFF Research Database (Denmark)

    Razzaghi, Fatemeh; Plauborg, Finn; Jacobsen, Sven-Erik

    2012-01-01

    Quinoa (Chenopodium quinoa Willd.) is believed to be tolerant to abiotic stress including salinity, drought and poor soil quality. To investigate the effect of soil type and soil-drying during the seed-filling phase on N-uptake, yield and water use, a Danish-bred cultivar (cv. Titicaca) was grown...... in field lysimeters with sand, sandy loam and sandy clay loam soil. Despite application of the same amount of nitrogen (120 kg N ha−1) to all plots, there were large differences in crop nitrogen-uptake for sandy clay loam (134 kg ha−1), sandy loam (102 kg ha−1) and sand (77 kg ha−1) under full irrigation....... This lead to higher interception of photosynthetic active radiation and higher seed yield on sandy clay loam (3.3 Mg ha−1) and sandy loam (3.0 Mg ha−1) than on sand (2.3 Mg ha−1). The soil with higher clay content had also the highest transpiration, crop evapotranspiration and yield due to the higher uptake...

  4. Remotely monitoring evaporation rate and soil water status using thermal imaging and "three-temperatures model (3T Model)" under field-scale conditions.

    Science.gov (United States)

    Qiu, Guo Yu; Zhao, Ming

    2010-03-01

    Remote monitoring of soil evaporation and soil water status is necessary for water resource and environment management. Ground based remote sensing can be the bridge between satellite remote sensing and ground-based point measurement. The primary object of this study is to provide an algorithm to estimate evaporation and soil water status by remote sensing and to verify its accuracy. Observations were carried out in a flat field with varied soil water content. High-resolution thermal images were taken with a thermal camera; soil evaporation was measured with a weighing lysimeter; weather data were recorded at a nearby meteorological station. Based on the thermal imaging and the three-temperatures model (3T model), we developed an algorithm to estimate soil evaporation and soil water status. The required parameters of the proposed method were soil surface temperature, air temperature, and solar radiation. By using the proposed method, daily variation in soil evaporation was estimated. Meanwhile, soil water status was remotely monitored by using the soil evaporation transfer coefficient. Results showed that the daily variation trends of measured and estimated evaporation agreed with each other, with a regression line of y = 0.92x and coefficient of determination R(2) = 0.69. The simplicity of the proposed method makes the 3T model a potentially valuable tool for remote sensing.

  5. Quantized fields in external field. Pt. 2

    International Nuclear Information System (INIS)

    Bellissard, J.

    1976-01-01

    The case of a charged scalar field is considered first. The existence of the corresponding Green's functions is proved. For weak fields, as well as pure electric or scalar external fields, the Bogoliubov S-operator is shown to be unitary, covariant, causal up-to-a-phase. These results are generalised to a class of higher spin quantized fields, 'nicely' coupled to external fields, which includes the Dirac theory, and in the case of minimal and magnetic dipole coupling, the spin one Petiau-Duffin-Kemmer theory. (orig.) [de

  6. Determination of correlation and scaling factors of radionuclides in the contaminated soils from experimental lysimetric field

    International Nuclear Information System (INIS)

    Dulanska, S.

    2009-04-01

    Correlation and regression analyses are often confused in evaluations of experimental results. However, the correlation analysis describes the influence of one variable level changes to changes of the other variable levels and holds for the variables measured quantitatively. It detects the existence and nature of dependencies, measures the goodness-of-fit of an actual model and tests the hypotheses of statistical significance of the model proposed. The y variable does not depend on the x variable but two random variables, x and y, vary jointly. The regression model, however, takes the independent variable x as a non-random variable and the dependent variable y as a random one, in contrast to the correlation model. There are a number of common difficulties associated with real datasets. The first involves the detection and elimination of outliers in the original data. We think of data as being divided into two classes (1) good observations (the majority of data) reflecting population scatter of data and (2) the outliers (if any) being a part of the so-called influential fatal points or noise. The goal of any outlier detection is to find this true partition and, thus, separate good from outlying observations. Regression diagnostics represent procedures for an examination of the regression triplet (data, model, method) for identification of (a) the data quality for a proposed model; (b) the model quality for a given set of data; (c) a fulfillment of all least-squares assumptions. Scheme and statistical evaluation of suitable scaling models for the monitoring of observed radionuclides 241 Am, 238 Pu and 239 , 240 Pu in real contaminated soils of experimental lysimetric field on the basis of experimental results were the objectives. Suitable scaling models for 241 Am, 238 Pu and 239 , 240 Pu radionuclide monitoring in contaminated soil samples placed in an experimental lysimeter have been proven by a regression triplet analysis. Estimates of and parameters for all

  7. Large-scale demonstration of waste solidification in saltstone

    International Nuclear Information System (INIS)

    McIntyre, P.F.; Oblath, S.B.; Wilhite, E.L.

    1988-05-01

    The saltstone lysimeters are a large scale demonstration of a disposal concept for decontaminated salt solution resulting from in-tank processing of defense waste. The lysimeter experiment has provided data on the leaching behavior of large saltstone monoliths under realistic field conditions. The results also will be used to compare the effect of capping the wasteform on contaminant release. Biweekly monitoring of sump leachate from three lysimeters has continued on a routine basis for approximately 3 years. An uncapped lysimeter has shown the highest levels of nitrate and 99 Tc release. Gravel and clay capped lysimeters have shown levels equivalent to or slightly higher than background rainwater levels. Mathematical model predictions have been compared to lysimeter results. The models will be applied to predict the impact of saltstone disposal on groundwater quality. 9 refs., 5 figs., 3 tabs

  8. Gravitation and vacuum field

    International Nuclear Information System (INIS)

    Tevikyan, R.V.

    1986-01-01

    This paper presents equations that describe particles with spins s = 0, 1/2, 1 completely and which also describe 2s + 2 limiting fields as E → ∞. It is shown that the ordinary Hilbert-Einstein action for the gravitation field must be augmented by the action for the Bose vacuum field. This means that one must introduce in the gravitational equations a cosmological term proportional to the square of the strength of the Bose vacuum field. It is shown that the theory of gravitation describes three realities: matter, field, and vacuum field. A new form of matter--the vacuum field--is introduced into field theory

  9. Fractal vector optical fields.

    Science.gov (United States)

    Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2016-07-15

    We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field.

  10. Electric Field Imaging

    Data.gov (United States)

    National Aeronautics and Space Administration — NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields....

  11. How fields vary.

    Science.gov (United States)

    Krause, Monika

    2018-03-01

    Field theorists have long insisted that research needs to pay attention to the particular properties of each field studied. But while much field-theoretical research is comparative, either explicitly or implicitly, scholars have only begun to develop the language for describing the dimensions along which fields can be similar to and different from each other. In this context, this paper articulates an agenda for the analysis of variable properties of fields. It discusses variation in the degree but also in the kind of field autonomy. It discusses different dimensions of variation in field structure: fields can be more or less contested, and more or less hierarchical. The structure of symbolic oppositions in a field may take different forms. Lastly, it analyses the dimensions of variation highlighted by research on fields on the sub- and transnational scale. Post-national analysis allows us to ask how fields relate to fields of the same kind on different scales, and how fields relate to fields on the same scale in other national contexts. It allows us to ask about the role resources from other scales play in structuring symbolic oppositions within fields. A more fine-tuned vocabulary for field variation can help us better describe particular fields and it is a precondition for generating hypotheses about the conditions under which we can expect to observe fields with specified characteristics. © London School of Economics and Political Science 2017.

  12. Magnetic Field Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity,...

  13. Magnetic field reconnexion in a sheared field

    International Nuclear Information System (INIS)

    Ugai, M.

    1981-01-01

    A nonlinear development of the Petschek mode in a sheared magnetic field where there is a field component Bsub(z) along an X line is numerically studied. It is found that finite-amplitude intermediate waves, adjacent to the slow shock, may eventually stand in the quasi-steady configuration; on the other hand, the fundamental characteristics of the Petschek-mode development are scarcely influenced, either qualitatively or quantitatively, by the Bsub(z) field. (author)

  14. Wake fields and wake field acceleration

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Wilson, P.B.; Weiland, T.

    1984-12-01

    In this lecture we introduce the concepts of wake fields and wake potentials, examine some basic properties of these functions, show how they can be calculated, and look briefly at a few important applications. One such application is wake field acceleration. The wake field accelerator is capable of producing the high gradients required for future very high energy e + e - linear colliders. The principles of wake field acceleration, and a brief description of experiments in progress in this area, are presented in the concluding section. 40 references, 27 figures

  15. On Jacobi-fields

    International Nuclear Information System (INIS)

    Bruening, E.

    1981-01-01

    The concept of a Jacobi-field is introduced as such a field for which the field-operators have the form of a generalized Jacobi-matrix with respect to the n-field-sector decomposition of the state-space. It is argued that the class of Jacobi-fields is of interest for relativistic quantum field theory for two reasons: (a) Jacobi-fields allow a direct association of particles (charges etc.) with fields. The concept of (generalized) creation- and annihilation-operators is thus available. (b) Jacobi-fields belong to that class of fields which can be characterized in terms of finitely many vacuum expectation values. A characterization of Jacobi-fields in terms of continuity and hermiticity properties of their system of vacuum expectation values is derived. Furthermore it is argued that all examples of relativistic quantum fields in a four-dimensional space-time are Jacobi-fields. This is evident for generalized free fields and Wick-powers of free fields, but is also true for a class of generalized Wick-powers of generalized free fields. (Auth.)

  16. Field Trips. Beginnings Workshop.

    Science.gov (United States)

    Cartwright, Sally; Aronson, Susan S.; Stacey, Susan; Winbush, Olga

    2001-01-01

    Five articles highlight benefits and organization of field trips: (1) "Field Trips Promote Child Learning at Its Best"; (2) "Planning for Maximum Benefit, Minimum Risk"; (3) "Coaching Community Hosts"; (4) "The Story of a Field Trip: Trash and Its Place within Children's Learning and Community"; and (5) "Field Trip Stories and Perspectives" (from…

  17. Field Campaign Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, J. W. [DOE ARM Climate Research Facility, Washington, DC (United States); Chapman, L. A. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-12-01

    This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

  18. The Galactic magnetic fields

    International Nuclear Information System (INIS)

    Han Jinlin

    2006-01-01

    A good progress has been made on studies of Galactic magnetic fields in last 10 years. I describe what we want to know about the Galactic magnetic fields, and then review we current knowledge about magnetic fields in the Galactic disk, the Galactic halo and the field strengths. I also listed many unsolved problems on this area

  19. Gauge fields in a torsion field

    International Nuclear Information System (INIS)

    Rosu, Ion

    2004-01-01

    In this paper we analyse the motion and the field equations in a non-null curvature and torsion space. In this 4-n dimensional space, the connection coefficients are γ bc a = 1/2S bc a + 1/2T bc a, where S bc a is the symmetrical part and T bc a are the components of the torsion tensor. We will consider that all the fields depend on x = x α , α = 1,2,3,4 and do not depend on y = y k , k=1,2,...,n. The factor S bc a depends on the components of the metric tensor g αβ (x) and on the gauge fields A ν s 0 (x) and the components of the torsion depend only on the gauge fields A ν s 0 (x). We take into consideration the particular case for which the geodesic equations coincide with the motion equations in the presence of the gravitational and the gauge fields. In this case the field equations are Einstein equations in a 4-n dimensional space. We show that both the geodesic equations and the field equations can be obtained from a variational principle. (author)

  20. Vinasse application to sugar cane fields. Effect on the unsaturated zone and groundwater at Valle del Cauca (Colombia).

    Science.gov (United States)

    Ortegón, Gloria Páez; Arboleda, Fernando Muñoz; Candela, Lucila; Tamoh, Karim; Valdes-Abellan, Javier

    2016-01-01

    Extensive application of vinasse, a subproduct from sugar cane plantations for bioethanol production, is currently taking place as a source of nutrients that forms part of agricultural management in different agroclimatic regions. Liquid vinasse composition is characterised by high variability of organic compounds and major ions, acid pH (4.7), high TDS concentration (117,416-599,400mgL(-1)) and elevated EC (14,350-64,099μScm(-1)). A large-scale sugar cane field application is taking place in Valle del Cauca (Colombia), where monitoring of soil, unsaturated zone and the aquifer underneath has been made since 2006 to evaluate possible impacts on three experimental plots. For this assessment, monitoring wells and piezometers were installed to determine groundwater flow and water samples were collected for chemical analysis. In the unsaturated zone, tensiometers were installed at different depths to determine flow patterns, while suction lysimeters were used for water sample chemical determinations. The findings show that in the sandy loam plot (Hacienda Real), the unsaturated zone is characterised by low water retention, showing a high transport capacity, while the other two plots of silty composition presented temporal saturation due to La Niña event (2010-2011). The strong La Niña effect on aquifer recharge which would dilute the infiltrated water during the monitoring period and, on the other hand dissolution of possible precipitated salts bringing them back into solution may occur. A slight increase in the concentration of major ions was observed in groundwater (~5% of TDS), which can be attributed to a combination of factors: vinasse dilution produced by water input and hydrochemical processes along with nutrient removal produced by sugar cane uptake. This fact may make the aquifer vulnerable to contamination. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Engineering field theory

    CERN Document Server

    Baden Fuller, A J

    2014-01-01

    Engineering Field Theory focuses on the applications of field theory in gravitation, electrostatics, magnetism, electric current flow, conductive heat transfer, fluid flow, and seepage.The manuscript first ponders on electric flux, electrical materials, and flux function. Discussions focus on field intensity at the surface of a conductor, force on a charged surface, atomic properties, doublet and uniform field, flux tube and flux line, line charge and line sink, field of a surface charge, field intensity, flux density, permittivity, and Coulomb's law. The text then takes a look at gravitation

  2. Ambient Field Analysis at Groningen Gas Field

    Science.gov (United States)

    Spica, Z.; Nakata, N.; Beroza, G. C.

    2016-12-01

    We analyze continuous ambient-field data at Groningen gas field (Netherlands) through cross-correlation processing. The Groningen array is composed of 75 shallow boreholes with 6 km spacing, which contain a 3C surface accelerometer and four 5-Hz 3C borehole geophones spaced at 50 m depth intervals. We successfully retrieve coherent waves from ambient seismic field on the 9 components between stations. Results show high SNR signal in the frequency range of 0.125-1 Hz, and the ZZ, ZR, RZ, RR and TT components show much stronger wave energy than other components as expected. This poster discuss the different type of waves retrieved, the utility of the combination of borehole and surface observations, future development as well as the importance to compute the 9 components of the Green's tensor to better understand the wave field propriety with ambient noise.

  3. Covariant Noncommutative Field Theory

    Energy Technology Data Exchange (ETDEWEB)

    Estrada-Jimenez, S [Licenciaturas en Fisica y en Matematicas, Facultad de Ingenieria, Universidad Autonoma de Chiapas Calle 4a Ote. Nte. 1428, Tuxtla Gutierrez, Chiapas (Mexico); Garcia-Compean, H [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN P.O. Box 14-740, 07000 Mexico D.F., Mexico and Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Monterrey Via del Conocimiento 201, Parque de Investigacion e Innovacion Tecnologica (PIIT) Autopista nueva al Aeropuerto km 9.5, Lote 1, Manzana 29, cp. 66600 Apodaca Nuevo Leon (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato P.O. Box E-143, 37150 Leon Gto. (Mexico); Ramirez, C [Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000 Puebla (Mexico)

    2008-07-02

    The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced.

  4. Covariant Noncommutative Field Theory

    International Nuclear Information System (INIS)

    Estrada-Jimenez, S.; Garcia-Compean, H.; Obregon, O.; Ramirez, C.

    2008-01-01

    The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced

  5. Understanding Vector Fields.

    Science.gov (United States)

    Curjel, C. R.

    1990-01-01

    Presented are activities that help students understand the idea of a vector field. Included are definitions, flow lines, tangential and normal components along curves, flux and work, field conservation, and differential equations. (KR)

  6. Magnetic Field Grid Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Properties Calculator will computes the estimated values of Earth's magnetic field(declination, inclination, vertical component, northerly...

  7. Gauge field copies

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

    1979-01-01

    The construction of field strength copies without any gauge constraint is discussed. Several examples are given, one of which is not only a field strength copy but also (at the same time) a 'current copy'. (author) [pt

  8. Cosmological magnetic fields - V

    Indian Academy of Sciences (India)

    Magnetic fields seem to be everywhere that we can look in the universe, from our own ... The field tensor is observer-independent, while the electric and magnetic .... based on string theory [11], in which vacuum fluctuations of the field are ...

  9. Unified field theory

    International Nuclear Information System (INIS)

    Prasad, R.

    1975-01-01

    Results of researches into Unified Field Theory over the past seven years are presented. The subject is dealt with in chapters entitled: the choice of affine connection, algebraic properties of the vector fields, field laws obtained from the affine connection based on the path integral method, application to quantum theory and cosmology, interpretation of physical theory in terms of geometry. (U.K.)

  10. Politics of aviation fields

    Science.gov (United States)

    Vivent, Jacques

    1922-01-01

    In short, the "politics of aviation" lies in a few propositions: the need of having as large a number of fields as possible and of sufficient area; the utilization of the larger part of the existing military fields; the selection of uncultivated or unproductive fields, whenever technical conditions permit; ability to disregard (save in exceptional cases) objections of an agricultural nature.

  11. Finite discrete field theory

    International Nuclear Information System (INIS)

    Souza, Manoelito M. de

    1997-01-01

    We discuss the physical meaning and the geometric interpretation of implementation in classical field theories. The origin of infinities and other inconsistencies in field theories is traced to fields defined with support on the light cone; a finite and consistent field theory requires a light-cone generator as the field support. Then, we introduce a classical field theory with support on the light cone generators. It results on a description of discrete (point-like) interactions in terms of localized particle-like fields. We find the propagators of these particle-like fields and discuss their physical meaning, properties and consequences. They are conformally invariant, singularity-free, and describing a manifestly covariant (1 + 1)-dimensional dynamics in a (3 = 1) spacetime. Remarkably this conformal symmetry remains even for the propagation of a massive field in four spacetime dimensions. We apply this formalism to Classical electrodynamics and to the General Relativity Theory. The standard formalism with its distributed fields is retrieved in terms of spacetime average of the discrete field. Singularities are the by-products of the averaging process. This new formalism enlighten the meaning and the problem of field theory, and may allow a softer transition to a quantum theory. (author)

  12. ZEPHYR - poloidal field system

    International Nuclear Information System (INIS)

    Seidel, U.

    1982-04-01

    The basics of the poloidal field system of the ZEPHYR experiment are considered. From the physical data the requirements for the poloidal field are derived. Hence an appropriate coil configuration consisting of coil locations and corresponding currents is obtained. A suitable electrical circuit feeding the coils is described. A preliminary assessment of the dynamic control of the poloidal field system is given. (orig.)

  13. Magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1985-02-01

    The basic properties of the Hamiltonian representation of magnetic fields in canonical form are reviewed. The theory of canonical magnetic perturbation theory is then developed and applied to the time evolution of a magnetic field embedded in a toroidal plasma. Finally, the extension of the energy principle to tearing modes, utilizing the magnetic field line Hamiltonian, is outlined

  14. Omnigenous magnetic fields

    International Nuclear Information System (INIS)

    Stupakov, G.V.

    1982-01-01

    In omnigenous magnetic fields particles' drift surfaces coincide with plasma magnetic surfaces. In this paper we formulate equations of omnigenous magnetic fields in natural curvilinear coordinates. An analysis of fields which are omnigenous only in the paraxial approximation is presented. (author)

  15. Far field acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  16. Cosmic Magnetic Fields

    Science.gov (United States)

    Sánchez Almeida, J.; Martínez González, M. J.

    2018-05-01

    Magnetic fields play an important role in many astrophysical processes. They are difficult to detect and characterize since often their properties have to be inferred through interpreting the polarization of the light. Magnetic fields are also challenging to model and understand. Magnetized plasmas behave following highly non-linear differential equations having no general solution, so that every astrophysical problem represents a special case to be studied independently. Hence, magnetic fields are often an inconvenient subject which is overlooked or simply neglected (the elephant in the room, as they are dubbed in poster of the school). Such difficulty burdens the research on magnetic fields, which has evolved to become a very technical subject, with many small disconnected communities studying specific aspects and details. The school tried to amend the situation by providing a unifying view of the subject. The students had a chance to understand the behavior of magnetic fields in all astrophysical contexts, from cosmology to the Sun, and from starbursts to AGNs. The school was planed to present a balanced yet complete review of our knowledge, with excursions into the unknown to point out present and future lines of research. The subject of Cosmic Magnetic Fields was split into seven different topics: cosmic magnetic field essentials, solar magnetic fields, stellar magnetic fields, the role of magnetic fields on AGN feedback, magnetic fields in galaxies, magnetic fields in galaxy clusters and at larger scales, and primordial magnetic fields and magnetic fields in the early Universe. The corresponding lectures were delivered by seven well known and experienced scientists that have played key roles in the major advances of the field during the last years: F. Cattaneo, P. Judge, O. Kochukhov, R. Keppens, R. Beck, K. Dolag, and F. Finelli. Their lectures were recorded and are freely available at the IAC website: http://iactalks.iac.es/talks/serie/19.

  17. Quantum field theory

    International Nuclear Information System (INIS)

    Ryder, L.H.

    1985-01-01

    This introduction to the ideas and techniques of quantum field theory presents the material as simply as possible and is designed for graduate research students. After a brief survey of particle physics, the quantum theory of scalar and spinor fields and then of gauge fields, is developed. The emphasis throughout is on functional methods, which have played a large part in modern field theory. The book concludes with a bridge survey of ''topological'' objects in field theory and assumes a knowledge of quantum mechanics and special relativity

  18. Unitary field theories

    International Nuclear Information System (INIS)

    Bergmann, P.G.

    1980-01-01

    A problem of construction of the unitary field theory is discussed. The preconditions of the theory are briefly described. The main attention is paid to the geometrical interpretation of physical fields. The meaning of the conceptions of diversity and exfoliation is elucidated. Two unitary field theories are described: the Weyl conformic geometry and Calitzy five-dimensioned theory. It is proposed to consider supersymmetrical theories as a new approach to the problem of a unitary field theory. It is noted that the supergravitational theories are really unitary theories, since the fields figuring there do not assume invariant expansion

  19. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  20. Strong Magnetic Field Characterisation

    Science.gov (United States)

    2012-04-01

    an advertised surface field of approximately 0.5 T were used to supply the static magnetic field source. The disc magnet had a diameter of 50 mm and... colour bar indicates the magnetic field strength set to an arbitrary 0.25 T. The white area has a field >0.25 T. The size of the arrow is proportional...9 shows the magnetic field strength along a slice in the XZ plane. The colours represent the total UNCLASSIFIED 10 UNCLASSIFIED DSTO-TR-2699

  1. Classical field theory

    CERN Document Server

    Franklin, Joel

    2017-01-01

    Classical field theory, which concerns the generation and interaction of fields, is a logical precursor to quantum field theory, and can be used to describe phenomena such as gravity and electromagnetism. Written for advanced undergraduates, and appropriate for graduate level classes, this book provides a comprehensive introduction to field theories, with a focus on their relativistic structural elements. Such structural notions enable a deeper understanding of Maxwell's equations, which lie at the heart of electromagnetism, and can also be applied to modern variants such as Chern–Simons and Born–Infeld. The structure of field theories and their physical predictions are illustrated with compelling examples, making this book perfect as a text in a dedicated field theory course, for self-study, or as a reference for those interested in classical field theory, advanced electromagnetism, or general relativity. Demonstrating a modern approach to model building, this text is also ideal for students of theoretic...

  2. Earth's electric field

    International Nuclear Information System (INIS)

    Kelley, M.C.

    1978-01-01

    The earth becomes charged during thunderstorm activity and discharges through the weak conducting atmosphere. Balloon and rocket studies infer that a high altitude electric field penetrates virtually unattenuated through the atmosphere, at least as far as balloon heights. The field has two primary sources. At low and mid latitudes, interaction between the earth's magnetic field and the neutral wind creates electric fields. At latitudes above 60 0 , the high altitude electrical structure is dominated by the interaction between the solar wind and the earth's magnetic field. The auroral light is emitted by atmospheric atoms and molecules excited by electrons with potentials of many thousands volts. The potentials are induced by the solar wind. Recent satellite data shows that the electrons get this energy by passing through a localized electric field about 6000 km above the auroral zone. Several rocket and satellite experiments used to study the earth's electric field are discussed

  3. Forces in electromagnetic field and gravitational field

    OpenAIRE

    Weng, Zihua

    2008-01-01

    The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in...

  4. Continuum gauge fields from lattice gauge fields

    International Nuclear Information System (INIS)

    Goeckeler, M.; Kronfeld, A.S.; Schierholz, G.; Wiese, U.J.

    1993-01-01

    On the lattice some of the salient features of pure gauge theories and of gauge theories with fermions in complex representations of the gauge group seem to be lost. These features can be recovered by considering part of the theory in the continuum. The prerequisite for that is the construction of continuum gauge fields from lattice gauge fields. Such a construction, which is gauge covariant and complies with geometrical constructions of the topological charge on the lattice, is given in this paper. The procedure is explicitly carried out in the U(1) theory in two dimensions, where it leads to simple results. (orig.)

  5. Polarimetry of random fields

    Science.gov (United States)

    Ellis, Jeremy

    On temporal, spatial and spectral scales which are small enough, all fields are fully polarized. In the optical regime, however, instantaneous fields can rarely be examined, and, instead, only average quantities are accessible. The study of polarimetry is concerned with both the description of electromagnetic fields and the characterization of media a field has interacted with. The polarimetric information is conventionally presented in terms of second order field correlations which are averaged over the ensemble of field realizations. Motivated by the deficiencies of classical polarimetry in dealing with specific practical situations, this dissertation expands the traditional polarimetric approaches to include higher order field correlations and the description of fields fluctuating in three dimensions. In relation to characterization of depolarizing media, a number of fourth-order correlations are introduced in this dissertation. Measurements of full polarization distributions, and the subsequent evaluation of Stokes vector element correlations and Complex Degree of Mutual Polarization demonstrate the use of these quantities for material discrimination and characterization. Recent advancements in detection capabilities allow access to fields near their sources and close to material boundaries, where a unique direction of propagation is not evident. Similarly, there exist classical situations such as overlapping beams, focusing, or diffusive scattering in which there is no unique transverse direction. In this dissertation, the correlation matrix formalism is expanded to describe three dimensional electromagnetic fields, providing a definition for the degree of polarization of such a field. It is also shown that, because of the dimensionality of the problem, a second parameter is necessary to fully describe the polarimetric properties of three dimensional fields. Measurements of second-order correlations of a three dimensional field are demonstrated, allowing the

  6. Covariant electromagnetic field lines

    Science.gov (United States)

    Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.

    2017-08-01

    Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.

  7. Partial Komori fields and imperative Komori fields

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2009-01-01

    This paper is concerned with the status of 1/0 and ways to deal with it. These matters are treated in the setting of Komori fields, also known as non-trivial cancellation meadows. Different viewpoints on the status of 1/0 exist in mathematics and theoretical computer science. We give a simple

  8. Field measurements of groundwater pollution from agricultural land use

    International Nuclear Information System (INIS)

    Cepuder, P.

    2000-01-01

    This study was carried out in a problem area located to the northeast of Vienna. Several devices were installed for collecting water samples from the soil profile to measure nitrate concentration: suction cups, soil-water samplers, tensiometers and small lysimeters. Measurements of N leaching from four levels of fertilizer application were made at Gross Enzersdorf under irrigated wheat using suction cups and lysimeters. In order to determine fertilizer-N uptake by plants and the amounts retained in the soil and leached, 15 N-enriched fertilizer was applied to micro-plots. The nitrate concentrations below the root zone were measured for winter wheat followed by a cover crop, using suction cups. Soil-water contents were measured in the soil profile with a neutron probe and gypsum blocks, and suctions were measured with tensiometers at four depths. The yields of crops together with total N in grain and straw from fertilizer and soil were calculated. Also presented are data on the mineralization, immobilization and actual fertilizer used by the crops. Winter wheat took up between 27% and 44% of the applied fertilizer. The storage of fertilizer N in soil ranged between 22% and 36%, and only a small fraction was leached. (author)

  9. UPWARD MOVEMENT OF PLUTONIUM TO SURFACE SEDIMENTS DURING AN 11-YEAR FIELD STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D.; Beals, D.; Cadieux, J.; Halverson, J.

    2010-01-25

    An 11-y lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The {sup 240}Pu/{sup 239}Pu and {sup 242}Pu/{sup 239}Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments.

  10. Nonlocal continuum field theories

    CERN Document Server

    2002-01-01

    Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...

  11. Simulated workplace neutron fields

    International Nuclear Information System (INIS)

    Lacoste, V.; Taylor, G.; Rottger, S.

    2011-01-01

    The use of simulated workplace neutron fields, which aim at replicating radiation fields at practical workplaces, is an alternative solution for the calibration of neutron dosemeters. They offer more appropriate calibration coefficients when the mean fluence-to-dose equivalent conversion coefficients of the simulated and practical fields are comparable. Intensive Monte Carlo modelling work has become quite indispensable for the design and/or the characterization of the produced mixed neutron/photon fields, and the use of Bonner sphere systems and proton recoil spectrometers is also mandatory for a reliable experimental determination of the neutron fluence energy distribution over the whole energy range. The establishment of a calibration capability with a simulated workplace neutron field is not an easy task; to date only few facilities are available as standard calibration fields. (authors)

  12. Nonequilibrium quantum field theories

    International Nuclear Information System (INIS)

    Niemi, A.J.

    1988-01-01

    Combining the Feynman-Vernon influence functional formalism with the real-time formulation of finite-temperature quantum field theories we present a general approach to relativistic quantum field theories out of thermal equilibrium. We clarify the physical meaning of the additional fields encountered in the real-time formulation of quantum statistics and outline diagrammatic rules for perturbative nonequilibrium computations. We derive a generalization of Boltzmann's equation which gives a complete characterization of relativistic nonequilibrium phenomena. (orig.)

  13. Organic magnetic field sensor

    Energy Technology Data Exchange (ETDEWEB)

    McCamey, Dane; Boehme, Christoph

    2017-01-24

    An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

  14. Elementary quantum field theory

    International Nuclear Information System (INIS)

    Thirring, W.; Henley, E.M.

    1975-01-01

    The first section of the book deals with the mathematical and physical description of a quantum field with the Bose-Einstein statistics and discusses observables, invariants of the field, and inner symmetries. The second section develops further methods for solvable interactions of a quantum field with static source. Section 3 explains with the aid of the Chew-Low model especially pion-nucleon scattering, static properties of nucleons, electromagnetic phenomena, and nuclear forces. (BJ/LN) [de

  15. Wake field accelerators

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1986-02-01

    In a wake field accelerator a high current driving bunch injected into a structure or plasma produces intense induced fields, which are in turn used to accelerate a trailing charge or bunch. The basic concepts of wake field acceleration are described. Wake potentials for closed cavities and periodic structures are derived, as are wake potentials on a collinear path with a charge distribution. Cylindrically symmetric structures excited by a beam in the form of a ring are considered

  16. Geomagnetic field, global pattern

    OpenAIRE

    Macmillan, Susan

    2011-01-01

    The geomagnetic field is generated in the fluid outer core region of the Earth by electrical currents flowing in the slowly moving molten iron. In addition to sources in the Earth’s core, the geomagnetic field observable on the Earth’s surface has sources in the crust and in the ionosphere and magnetosphere. The signal from the core dominates, accounting for over 95% of the field at the Earth’s surface. The geomagnetic field varies on a range of scales, both temporal and spatial; the...

  17. Effective quantum field theories

    International Nuclear Information System (INIS)

    Georgi, H.M.

    1993-01-01

    The most appropriate description of particle interactions in the language of quantum field theory depends on the energy at which the interactions are studied; the description is in terms of an ''effective field theory'' that contains explicit reference only to those particles that are actually important at the energy being studied. The various themes of the article are: local quantum field theory, quantum electrodynamics, new physics, dimensional parameters and renormalizability, socio-dynamics of particle theory, spontaneously broken gauge theories, scale dependence, grand unified and effective field theories. 2 figs

  18. Closed string field theory

    International Nuclear Information System (INIS)

    Strominger, A.

    1987-01-01

    A gauge invariant cubic action describing bosonic closed string field theory is constructed. The gauge symmetries include local spacetime diffeomorphisms. The conventional closed string spectrum and trilinear couplings are reproduced after spontaneous symmetry breaking. The action S is constructed from the usual ''open string'' field of ghost number minus one half. It is given by the associator of the string field product which is non-vanishing because of associativity anomalies. S does not describe open string propagation because open string states associate and can thereby be shifted away. A field theory of closed and open strings can be obtained by adding to S the cubic open string action. (orig.)

  19. Dielectrics in electric fields

    CERN Document Server

    Raju, Gorur G

    2003-01-01

    Discover nontraditional applications of dielectric studies in this exceptionally crafted field reference or text for seniors and graduate students in power engineering tracks. This text contains more than 800 display equations and discusses polarization phenomena in dielectrics, the complex dielectric constant in an alternating electric field, dielectric relaxation and interfacial polarization, the measurement of absorption and desorption currents in time domains, and high field conduction phenomena. Dielectrics in Electric Fields is an interdisciplinary reference and text for professionals and students in electrical and electronics, chemical, biochemical, and environmental engineering; physical, surface, and colloid chemistry; materials science; and chemical physics.

  20. Geomagnetic field of earth

    International Nuclear Information System (INIS)

    Delipetrev, Marjan; Delipetrev, Blagoj; Panovska, Sanja

    2008-01-01

    In this paper is introduced the theory of geomagnetic field of the Earth. A homogenous and isotropic sphere is taken for a model of Earth with a bar magnet at its center as a magnetic potential. The understanding of the real origin of geomagnetic field produced from differential rotation of inner core with respect to the outer core of Earth is here presented. Special attention is given to the latest observed data of the established net of geomagnetic repeat stations in the Republic of Macedonia. Finally, the maps of elements of geomagnetic field and the equation for calculation of normal magnetic field of Earth are provided. (Author)

  1. Fields, symmetries, and quarks

    International Nuclear Information System (INIS)

    Mosel, U.

    1989-01-01

    'Fields, symmetries, and quarks' covers elements of quantum field theory, symmetries, gauge field theories and phenomenological descriptions of hadrons, with special emphasis on topics relevant to nuclear physics. It is aimed at nuclear physicists in general and at scientists who need a working knowledge of field theory, symmetry principles of elementary particles and their interactions and the quark structure of hadrons. The book starts out with an elementary introduction into classical field theory and its quantization. As gauge field theories require a working knowledge of global symmetries in field theories this topic is then discussed in detail. The following part is concerned with the general structure of gauge field theories and contains a thorough discussion of the still less widely known features of Non-Abelian gauge field theories. Quantum Chromodynamics (QCD), which is important for the understanding of hadronic matter, is discussed in the next section together with the quark compositions of hadrons. The last two chapters give a detailed discussion of phenomenological bag-models. The MIT bag is discussed, so that all theoretical calculations can be followed step by step. Since in all other bag-models the calculational methods and steps are essentially identical, this chapter should enable the reader to actually perform such calculations unaided. A last chapter finally discusses the topological bag-models which have become quite popular over the last few years. (orig.)

  2. Effective field theories

    International Nuclear Information System (INIS)

    Mack, G.; Kalkreuter, T.; Palma, G.; Speh, M.

    1992-05-01

    Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low utraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight from the effective Lagrangean. Methods will be discussed how to compute an effective low energy action from a given fundamental action, either analytically or numerically, or by a combination of both methods. Basically, the idea is to integrate out the high frequency components of fields. This requires the choice of a 'blockspin', i.e. the specification af a low frequency field as a function of the fundamental fields. These blockspins will be fields of the effective field theory. The blockspin need not be a field of the same type as one of the fundamental fields, and it may be composite. Special features of blockspin in nonabelian gauge theories will be discussed in some detail. In analytical work and in multigrid updating schemes one needs interpolation kernels A from coarse to fine grid in addition to the averaging kernels C which determines the blockspin. A neural net strategy for finding optimal kernels is presented. Numerical methods are applicable to obtain actions of effective theories on lattices of finite volume. The special case of a 'lattice' with a single site (the constraint effective potential) is of particular interest. In a higgs model, the effective action reduces in this case to the free energy, considered as a function of a gauge covariant magnetization. Its shape determines the phase structure of the theory. Its loop expansion with and without gauge fields can be used to determine finite size corrections to numerical data. (orig.)

  3. Treated wastewater and Nitrate transport beneath irrigated fields near Dodge city, Kansas

    Science.gov (United States)

    Sophocleous, M.; Townsend, M.A.; Vocasek, F.; Ma, Liwang; Ashok, K.C.

    2010-01-01

    Use of secondary-treated municipal wastewater for crop irrigation south of Dodge City, Kansas, where the soils are mainly of silty clay loam texture, has raised a concern that it has resulted in high nitratenitrogen concentrations (10-50 mg/kg) in the soil and deeper vadose zone, and also in the underlying deep (20-45 m) ground water. The goal of this field-monitoring project was to assess how and under what circumstances nitrogen (N) nutrients under cultivated corn that is irrigated with this treated wastewater can reach the deep ground water of the underlying High Plains aquifer, and what can realistically be done to minimize this problem. We collected 15.2-m-deep cores for physical and chemical properties characterization; installed neutron moisture-probe access tubes and suction lysimeters for periodic measurements; sampled area monitoring, irrigation, and domestic wells; performed dye-tracer experiments to examine soil preferential-flow processes through macropores; and obtained climatic, crop, irrigation, and N-application rate records. These data and additional information were used in the comprehensive Root Zone Water Quality Model (RZWQM2) to identify key parameters and processes that influence N losses in the study area. We demonstrated that nitrate-N transport processes result in significant accumulations of N in the thick vadose zone. We also showed that nitrate-N in the underlying ground water is increasing with time and that the source of the nitrate is from the wastewater applications. RZWQM2 simulations indicated that macropore flow is generated particularly during heavy rainfall events, but during our 2005-06 simulations the total macropore flow was only about 3% of precipitation for one of two investigated sites, whereas it was more than 13% for the other site. Our calibrated model for the two wastewater-irrigated study sites indicated that reducing current levels of corn N fertilization by half or more to the level of 170 kg/ha substantially

  4. Mathematical modelling and simulation of solar-assisted drying of bulk farm products; Mathematische Modellierung und Simulation der solar unterstuetzten Trocknung landwirtschaftlicher Schuettgueter

    Energy Technology Data Exchange (ETDEWEB)

    Maltry, W.; Ziegler, T.; Richter, I.

    1997-04-01

    The report deals with problems associated with the harnessing of solar energy for drying bulk farm products: technical fundamentals, enthalpy diagrams, models for grain drying, experimental investigations, analysis of drying processes, benefits and applications of drying processes, advances. (HW) [Deutsch] Der Bericht behandelt die Probleme der Solarenergienutzung zur Trockung landwirtschaftlicher Massengueter: - Trocknungstechnische Grundlagen - Enthalpie-Diagramme - Modelle zur Koernertrocknung - experimentelle Untersuchungen - Analyse von Trocknungsprozesse - Nutzen und Verwertbarkeit der Trocknungsprozesse - Fortschritte. (HW)

  5. Mathematical model for optimizing the design extraction pressure of a condensation turbine with district heat extraction. Mathematisches Modell zur Optimierung des Auslegungsentnahmedruckes an einer Kondensationsturbine mit Fernwaermeauskopplung

    Energy Technology Data Exchange (ETDEWEB)

    Grkovic, V [Novi Sad Univ. (Yugoslavia)

    1991-11-01

    A mathematical calculation model is explained, which enables optimization of the design pressure at the steam extraction point of a condensation extraction turbine. The results obtained show that the additional thermodynamic losses, which occur during turbine operation on variation of the heat load, can be reduced to a minimum by optimization of the extraction pressure. The optimal pressures at the extraction point, as well as the size of the economic effect are dependent on the selected technical design of the turbine, its maximum heat output and the basic heat load factor. (orig.).

  6. Mathematical modelling of the gasification of cellulose-containing biomass using a zoning model; Mathematische Modellierung der Vergasung zellulosehaltiger Biomasse mit Hilfe eines Zonenmodells

    Energy Technology Data Exchange (ETDEWEB)

    Jung, K; Saller, G; Funk, G; Krumm, W [Siegen Univ. (Gesamthochschule) (Germany). Inst. fuer Energietechnik

    1998-09-01

    The composition of the product gas is decisive for the further process stages. In contrast to coal gasification, which has been investigated for more than a century, there is still a lack of theoretical and experimental knowledge on biomass gasification. The contribution presents a mathematical model that is to provide deeper knowledge of the constant-flow fixed-bed gasifier, which is still widely regarded as a `black box`. (orig./SR) [Deutsch] Einen wesentlichen Prozessschritt der thermochemischen Konversion stellt der Vergasungsprozess dar, da die Zusammensetzung des erhaltenen Gases fuer die weiteren Prozessschritte von entscheidender Bedeutung ist. Im Gegensatz zur Vergasung von Kohle, die bereits seit fast 100 Jahren untersucht wird, besteht bei der Vergasung von Biomasse ein starker Nachholbedarf in Bezug auf das theoretische und experimentelle Detailwissen. In diesem Beitrag wird im Rahmen eines mathematischen Modells ein Ansatz vorgestellt, in dem der Gleichstrom-Festbettvergaser, der bisher meist als `blackbox` betrachtet wurde, weiter aufgeschluesselt wird. (orig./SR)

  7. twistors and gauge fields

    Directory of Open Access Journals (Sweden)

    A. G. Sergeev

    1986-01-01

    Full Text Available We describe briefly the basic ideas and results of the twistor theory. The main points: twistor representation of Minkowsky space, Penrose correspondence and its geometrical properties, twistor interpretation of linear massless fields, Yang-Mills fields (including instantons and monopoles and Einstein-Hilbert equations.

  8. Hyperfunction quantum field theory

    International Nuclear Information System (INIS)

    Nagamachi, S.; Mugibayashi, N.

    1976-01-01

    The quantum field theory in terms of Fourier hyperfunctions is constructed. The test function space for hyperfunctions does not contain C infinitely functios with compact support. In spite of this defect the support concept of H-valued Fourier hyperfunctions allows to formulate the locality axiom for hyperfunction quantum field theory. (orig.) [de

  9. Mean field games

    KAUST Repository

    Gomes, Diogo A.

    2014-01-06

    In this talk we will report on new results concerning the existence of smooth solutions for time dependent mean-field games. This new result is established through a combination of various tools including several a-priori estimates for time-dependent mean-field games combined with new techniques for the regularity of Hamilton-Jacobi equations.

  10. Quantum field theory

    CERN Document Server

    Sadovskii, Michael V

    2013-01-01

    This book discusses the main concepts of the Standard Model of elementary particles in a compact and straightforward way. The work illustrates the unity of modern theoretical physics by combining approaches and concepts of the quantum field theory and modern condensed matter theory. The inductive approach allows a deep understanding of ideas and methods used for solving problems in this field.

  11. Killing fields; The politics

    Energy Technology Data Exchange (ETDEWEB)

    Philips, Alasdair

    1990-02-01

    An overview considers the NRPB guidelines on possible health effects of low-level alternating electrical and magnetic fields and examines work by individuals on the hazards of microwave radiation, overhead power lines and childhood cancer, and the problems caused by electromagnetic fields at 50 Hz frequency. (U.K.).

  12. Moving Field Guides

    Science.gov (United States)

    Cassie Meador; Mark Twery; Meagan. Leatherbury

    2011-01-01

    The Moving Field Guides (MFG) project is a creative take on site interpretation. Moving Field Guides provide an example of how scientific and artistic endeavors work in parallel. Both begin with keen observations that produce information that must be analyzed, understood, and interpreted. That interpretation then needs to be communicated to others to complete the...

  13. Respirator field performance factors

    International Nuclear Information System (INIS)

    Skaggs, B.J.; DeField, J.D.; Strandberg, S.W.; Sutcliffe, C.R.

    1985-01-01

    The Industrial Hygiene Group assisted OSHA and the NRC in measurements of respirator performance under field conditions. They reviewed problems associated with sampling aerosols within the respirator in order to determine fit factors (FFs) or field performance factor (FPF). In addition, they designed an environmental chamber study to determine the effects of temperature and humidity on a respirator wearer

  14. Magnetic field on board

    International Nuclear Information System (INIS)

    Estevez Radio, H.; Fernandez Arenal, C.A.

    1995-01-01

    Here, the calculation of the magnetic field on board ships is performed, using matrix calculus, in a similar way as when the magnetic field in matter is studied. Thus the final formulas are written in a more compact form and they are obtained through a simpler way, more suitable for the university education. (Author)

  15. Pregnancy and electromagnetic fields

    International Nuclear Information System (INIS)

    Bisseriex, Ch.; Laurent, P.; Cabaret, Ph.; Bonnet, C.; Marteau, E.; Le Berre, G.; Tirlemont, S.; Castro, H.; Becker, A.; Demaret, Ph.; Donati, M.; Ganem, Y.; Moureaux, P.

    2011-07-01

    This document briefly indicates the status of knowledge regarding the effect of magnetic fields on biological tissues and pregnancy, outlines the lack of data on some frequencies and the weakness of studies on long term effects on child development. It evokes the issue of exposure assessment and that of identification of workstations exposed to electromagnetic fields

  16. Magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1984-03-01

    The magnetic field line Hamiltonian and the associated canonical form for the magnetic field are important concepts both for understanding toroidal plasma physics and for practical calculations. A number of important properties of the canonical or Hamiltonian representation are derived and their importance is explained

  17. Fields From Markov Chains

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2005-01-01

    A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly.......A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly....

  18. Pulsed electric fields

    Science.gov (United States)

    The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular co...

  19. MAGNETIC FIELDS OF STARS

    OpenAIRE

    Bychkov, V. D.; Bychkova, L. V.; Madej, J.

    2008-01-01

    Now it is known about 1212 stars of the main sequence and giants (from them 610 stars - it is chemically peculiarity (CP) stars) for which direct measurements of magnetic fields were spent (Bychkov et al.,2008). Let's consider, what representations were generated about magnetic fields (MT) of stars on the basis of available observations data.

  20. Quantization and nonlocal fields

    International Nuclear Information System (INIS)

    Kolerov, G.I.

    1977-01-01

    A relation between the postulate of causality and quatization conditions is considered for the scalar field. A formalism of outer forms given on the functional space is used. A current commutator is obtained for nonlogical fields in the space-like region

  1. Mean field games

    KAUST Repository

    Gomes, Diogo A.

    2014-01-01

    In this talk we will report on new results concerning the existence of smooth solutions for time dependent mean-field games. This new result is established through a combination of various tools including several a-priori estimates for time-dependent mean-field games combined with new techniques for the regularity of Hamilton-Jacobi equations.

  2. Unified field theory

    International Nuclear Information System (INIS)

    Vollendorf, F.

    1976-01-01

    A theory is developed in which the gravitational as well as the electromagnetic field is described in a purely geometrical manner. In the case of a static central symmetric field Newton's law of gravitation and Schwarzschild's line element are derived by means of an action principle. The same principle leads to Fermat's law which defines the world lines of photons. (orig.) [de

  3. Pregnant Field Students' Guilt

    Science.gov (United States)

    Baum, Nehami

    2006-01-01

    This study examined guilt feelings among social work students who were pregnant for the first time during field work training. Semi-structured interviews were conducted either in the 9th month (n=5) or 2-12 months after delivery (n=5). Content analysis revealed 6 main triggers, illustrated by excerpts, which stimulated field students' guilt…

  4. Electromagnetic fields in biological systems

    National Research Council Canada - National Science Library

    Lin, James C

    2012-01-01

    "Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

  5. The Coriolis field

    Science.gov (United States)

    Costa, L. Filipe; Natário, José

    2016-05-01

    We present a pedagogical discussion of the Coriolis field, emphasizing its not-so-well-understood aspects. We show that this field satisfies the field equations of the so-called Newton-Cartan theory, a generalization of Newtonian gravity that is covariant under changes of arbitrarily rotating and accelerated frames. Examples of solutions of this theory are given, including the Newtonian analogue of the Gödel universe. We discuss how to detect the Coriolis field by its effect on gyroscopes, of which the gyrocompass is an example. Finally, using a similar framework, we discuss the Coriolis field generated by mass currents in general relativity, and its measurement by the gravity probe B and LAGEOS/LARES experiments.

  6. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...

  7. Finite fields and applications

    CERN Document Server

    Mullen, Gary L

    2007-01-01

    This book provides a brief and accessible introduction to the theory of finite fields and to some of their many fascinating and practical applications. The first chapter is devoted to the theory of finite fields. After covering their construction and elementary properties, the authors discuss the trace and norm functions, bases for finite fields, and properties of polynomials over finite fields. Each of the remaining chapters details applications. Chapter 2 deals with combinatorial topics such as the construction of sets of orthogonal latin squares, affine and projective planes, block designs, and Hadamard matrices. Chapters 3 and 4 provide a number of constructions and basic properties of error-correcting codes and cryptographic systems using finite fields. Each chapter includes a set of exercises of varying levels of difficulty which help to further explain and motivate the material. Appendix A provides a brief review of the basic number theory and abstract algebra used in the text, as well as exercises rel...

  8. Dual double field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bergshoeff, Eric A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University,Stony Brook, NY 11794-3636 (United States); Penas, Victor A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-06-06

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for “exotic' dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  9. Field theory and strings

    International Nuclear Information System (INIS)

    Bonara, L.; Cotta-Ramusino, P.; Rinaldi, M.

    1987-01-01

    It is well-known that type I and heterotic superstring theories have a zero mass spectrum which correspond to the field content of N=1 supergravity theory coupled to supersymmetric Yang-Mills theory in 10-D. The authors study the field theory ''per se'', in the hope that simple consistency requirements will determine the theory completely once one knows the field content inherited from string theory. The simplest consistency requirements are: N=1 supersymmetry; and absence of chiral anomalies. This is what the authors discuss in this paper here leaving undetermined the question of the range of validity of the resulting field theory. As is known, a model of N=1 supergravity (SUGRA) coupled to supersymmetric Yang-Mills (SYM) theory was known in the form given by Chapline and Manton. The coupling of SUGRA to SYM was determined by the definition of the ''field strength'' 3-form H in this paper

  10. Narrowing the field

    DEFF Research Database (Denmark)

    Knudsen, Bo Nissen

    characteristics and the sequence of information in the series. Adding to the challenge is the macrostructural variation: The areas covered in printed form are covered with shifting principles of selecting the names to be published. Finding the right balance between letting the algorithms structure this complex....... As of now, no less than 45 different database fields have been found necessary to structure the information found in a single place-name entry – some fields mandatory, some nonmandatory. And using a relational database structure, some fields have multiple occurrences within one entry (i.e. multiple source...... forms for one entry a.s.f.). Having made the conscious decision to split up the information into so many categories (i.e. fields) – instead of employing a broad 'other information' field – sophisticated algorithms have been developed in order to identify information category from typographical...

  11. Magnetic fields in cosmology

    International Nuclear Information System (INIS)

    Madsen, M.S.

    1989-01-01

    The possible role of a large-scale relic magnetic field in the history of the Universe is considered. The perturbation of the cosmic microwave back-ground radiation on large angular scales due to a homogeneous magnetic field is estimated in a simple relativistic model. This allows corresponding limits to be placed on the magnitude of any such large-scale relic magnetic field at the present time. These limits are essentially the strongest which can be set on the largest scales. A corresponding bound is obtained by use of the requirement that the field should not spoil the predictions of primordial nucleosynthesis. It is noted that the existence of large-scale cosmic magnetic fields would circumvent the limits previously set - also on the basis of nucleosynthesis considerations - on the large-scale anisotropy now present in the Universe. (author)

  12. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields.......The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...

  13. Alfalfa (Medicago sativa L.) is tolerant to higher levels of salinity than previous guidelines indicated: Implications of field and greenhouse studies

    Science.gov (United States)

    Putnam, Daniel H.; Benes, Sharon; Galdi, Giuliano; Hutmacher, Bob; Grattan, Steve

    2017-04-01

    Alfalfa (Medicago sativa L.) is the most widely grown leguminous forage crop in North America and is valued for high productivity, quality, economic value, and for dairy productivity. Alfalfa has historically been classified as moderately sensitive to saline conditions, with yield declines predicted at >2 dS/m in the saturated soil paste extract. However, greenhouse, sand tank, and field studies over the past five years have confirmed that alfalfa can be grown with limited negative effects at much higher salinity levels. A broad collection of alfalfa varieties has exhibited a range of resistance at irrigation water salinities >5 dS/m ECw in greenhouse trials, with significant variation due to variety. USDA-ARS sand tank studies indicated similar or greater tolerances closer to 8 dS/m in the soil water, in addition to confirmation of significant varietal differences. A three-year field study on clay loam soil with applications of 5-7 dS/m ECw irrigation water indicated normal yields and excellent stand survivability. A second field study in the same soil type with levels from 8-10 dS/m ECw showed yield reductions of 10-15% but economic yields were still achieved at those levels. Field and greenhouse studies were conducted with mixed salt saline sodic waters typical of the San Joaquin Valley of California. Field evaluation of variety performance was subject to greater variation due to secondary salinity-soil interactions including water infiltration and crusting problems, not only salinity per-se. Thus, adequate irrigation water availability to the crop may be as important as salinity in impacting yields under field conditions. Once established, the deep-rooted characteristics of alfalfa enable utilization of deeper subsurface moisture, even at moderate to high salinity levels, as documented by USDA lysimeter studies. Significant advantages to salinity-tolerant varieties have been observed. It will be important to consider specific management factors which may enable

  14. Gauge fields and inflation

    Science.gov (United States)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  15. The earth's magnetic field

    International Nuclear Information System (INIS)

    Merrill, R.T.

    1983-01-01

    After a historical introduction in Chapter 1, the more traditional aspects of geomagnetism relating to the present field and historical observations are presented in Chapter 2. The various methods and techniques and theoretical background of palaeomagnetism are given in Chapter 3. Chapters 4, 5 and 6 present the results of palaeomagnetic and archaeomagnetic studies in three topics. Chapter 4 relates to studies of the geomagnetic field roughly back to about 50,000 years ago. Chapter 5 is about reversals of the geomagnetic field and Chapter 6 presents studies of the field for times older than 50,000 years and on the geological time scale of millions or hundreds of millions of years. Chapters 7, 8 and 9 provide insight into dynamo theory. Chapter 7 is essentially a non-mathematical attempt to explain the physical basis of dynamo theories to palaeomagnetists. This is followed in Chapter 8 by a more advanced theoretical treatment. Chapter 9 explains theoretical aspects of secular variation and the origin of reversals of the geomagnetic field. Chapter 10 is our attempt to relate theory to experiment and vice versa. The final two chapters consider the magnetic fields of the moon, sun, planets and meteorites, in an attempt to determine the necessary and sufficient conditions for magnetic field generation in large solar system bodies. (author)

  16. The Juno Magnetic Field Investigation

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Benn, Mathias; Bjarnø, Jonas Bækby

    2017-01-01

    The Juno Magnetic Field investigation (MAG) characterizes Jupiter’s planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor ...

  17. Robotics Potential Fields

    Directory of Open Access Journals (Sweden)

    Jordi Lucero

    2009-01-01

    Full Text Available This problem was to calculate the path a robot would take to navigate an obstacle field and get to its goal. Three obstacles were given as negative potential fields which the robot avoided, and a goal was given a positive potential field that attracted the robot. The robot decided each step based on its distance, angle, and influence from every object. After each step, the robot recalculated and determined its next step until it reached its goal. The robot's calculations and steps were simulated with Microsoft Excel.

  18. International Geomagnetic Reference Field

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.

    2010-01-01

    The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V‐MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field...... model for epoch 2010.0, and a linear predictive secular variation model for 2010.0–2015.0. In this note the equations defining the IGRF model are provided along with the spherical harmonic coefficients for the eleventh generation. Maps of the magnetic declination, inclination and total intensity...

  19. Room Acoustical Fields

    CERN Document Server

    Mechel, Fridolin

    2013-01-01

    This book presents the theory of room acoustical fields and revises the Mirror Source Methods for practical computational use, emphasizing the wave character of acoustical fields.  The presented higher methods include the concepts of “Mirror Point Sources” and “Corner sources which allow for an excellent approximation of complex room geometries and even equipped rooms. In contrast to classical description, this book extends the theory of sound fields describing them by their complex sound pressure and the particle velocity. This approach enables accurate descriptions of interference and absorption phenomena.

  20. On the Schrodinger field

    International Nuclear Information System (INIS)

    Takahashi, Y.

    1986-01-01

    A brief but systematic discussion of the Schrodinger field is presented from the view point of quantized field theory. It is pointed out that the local momentum conservation equation is not of the usual continuity equation type when two-body potential interaction is presented and nevertheless the total momentum is globally conserved. The Schrodinger equation can be cast into a multicomponent equation containing only first order derivatives, depending on its spin contents. In case of spin 1/2, the g-factor is shown to be 2 even in purely non-relativistic Schrodinger field, in contrast with the general belief that g=2 is a relativistic effect

  1. Ridge and Furrow Fields

    DEFF Research Database (Denmark)

    Møller, Per Grau

    2016-01-01

    Ridge and furrow is a specific way of ploughing which makes fields of systematic ridges and furrows like a rubbing washboard. They are part of an overall openfield system, but the focus in this paper is on the functionality of the fields. There are many indications that agro-technological reasons...... systems and the establishment of basic structures like villages (with churches) and townships and states (in northern Europe). The fields can be considered as a resilient structure lasting for 800 years, along with the same basic physical structures in society....

  2. Waste migration studies at the Savannah River Plant burial ground

    International Nuclear Information System (INIS)

    Stone, J.A.; Oblath, S.B.; Hawkins, R.H.; Grant, M.W.; Hoeffner, S.L.; King, C.M.

    1985-01-01

    The low-level radioactive waste burial ground at the Savannah River Plant is a typical shallow-land-burial disposal site in a humid region. Studies of waste migration at this site provide generic data for designing other disposal facilities. A program of field, laboratory, and modeling studies for the SRP burial ground has been conducted for several years. Recent results of lysimeter tests, soil-water chemistry studies, and transport modeling are reported. The lysimeter experiments include ongoing tests with 40 lysimeters containing a variety of defense wastes, and recently concluded lysimeter tests with tritium and plutonium waste forms. The tritium lysimeter operated 12 years. In chemistry studies, measurements of soil-water distribution coefficients (K/sub d/) were concluded. Current emphasis is on identification of trace organic compounds in groundwater from the burial site. Development of the dose-to-man model was completed, and the computer code is available for routine use. 16 refs., 2 figs., 2 tabs

  3. Geophysical Field Theory

    International Nuclear Information System (INIS)

    Eloranta, E.

    2003-11-01

    The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

  4. Field Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Field Research Facility (FRF) located in Duck, N.C. was established in 1977 to support the U.S. Army Corps of Engineers' coastal engineering mission. The FRF is...

  5. Reversed field pinch diagnostics

    International Nuclear Information System (INIS)

    Weber, P.G.

    1986-01-01

    The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP

  6. Algebraic conformal field theory

    International Nuclear Information System (INIS)

    Fuchs, J.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1991-11-01

    Many conformal field theory features are special versions of structures which are present in arbitrary 2-dimensional quantum field theories. So it makes sense to describe 2-dimensional conformal field theories in context of algebraic theory of superselection sectors. While most of the results of the algebraic theory are rather abstract, conformal field theories offer the possibility to work out many formulae explicitly. In particular, one can construct the full algebra A-bar of global observables and the endomorphisms of A-bar which represent the superselection sectors. Some explicit results are presented for the level 1 so(N) WZW theories; the algebra A-bar is found to be the enveloping algebra of a Lie algebra L-bar which is an extension of the chiral symmetry algebra of the WZW theory. (author). 21 refs., 6 figs

  7. Earth's Magnetic Field

    DEFF Research Database (Denmark)

    This volume provides a comprehensive view on the different sources of the geomagnetic field both in the Earth’s interior and from the field’s interaction with the terrestrial atmosphere and the solar wind. It combines expertise from various relevant areas of geomagnetic and near Earth space...... research with the aim to better characterise the state and dynamics of Earth’s magnetic field. Advances in the exploitation of geomagnetic observations hold a huge potential not only for an improved quantitative description of the field source but also for a better understanding of the underlying processes...... and space observations, and on state-of-the-art empirical models and physics-based simulations. Thus, it provides an in-depth overview over recent achievements, current limitations and challenges, and future opportunities in the field of geomagnetism and space sciences....

  8. The master field revisited

    International Nuclear Information System (INIS)

    Gopakumar, R.

    1996-01-01

    We review recent work on the master field in large N theories. In particular the mathematical framework appropriate for its construction is sketched. The calculational utility of this framework is demonstrated in the case of QCD 2 . (orig.)

  9. Field Geology/Processes

    Science.gov (United States)

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

    1996-01-01

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

  10. Maine Field Station

    Data.gov (United States)

    Federal Laboratory Consortium — In 2000 NOAA's National Marine Fisheries Service established the Maine Field Station in Orono, ME to have more direct involvement in the conservation of the living...

  11. Assessing the performance of a cold region evapotranspiration landfill cover using lysimetry and electrical resistivity tomography.

    Science.gov (United States)

    Schnabel, William E; Munk, Jens; Abichou, Tarek; Barnes, David; Lee, William; Pape, Barbara

    2012-01-01

    In order to test the efficacy ofa cold-region evapotranspiration (ET) landfill cover against a conventional compacted clay (CCL) landfill cover, two pilot scale covers were constructed in side-by-side basin lysimeters (20m x 10m x 2m) at a site in Anchorage, Alaska. The primary basis of comparison between the two lysimeters was the percolation of moisture from the bottom of each lysimeter. Between 30 April 2005 and 16 May 2006, 51.5 mm of water percolated from the ET lysimeter, compared to 50.6 mm for the the CCL lysimeter. This difference was not found to be significant at the 95% confidence level. As part of the project, electrical resistivity tomography (ERT) was utilized to measure and map soil moisture in ET lysimeter cross sections. The ERT-generated cross sections were found to accurately predict the onset and duration of lysimeter percolation. Moreover, ERT-generated soil moisture values demonstrated a strong linear relationship to lysimeter percolation rates (R-Squared = 0.92). Consequently, ERT is proposed as a reliable tool for assessing the function of field scale ET covers in the absence of drainage measurement devices.

  12. Three dimensional field computation

    International Nuclear Information System (INIS)

    Trowbridge, C.W.

    1981-06-01

    Recent research work carried out at Rutherford and Appleton Laboratories into the Computation of Electromagnetic Fields is summarised. The topics covered include algorithms for integral and differential methods for the solution of 3D magnetostatic fields, comparison of results with experiment and an investigation into the strengths and weaknesses of both methods for an analytic problem. The paper concludes with a brief summary of the work in progress on the solution of 3D eddy currents using differential finite elements. (author)

  13. Magnetic field of Mercury

    International Nuclear Information System (INIS)

    Jackson, D.J.; Beard, D.B.

    1977-01-01

    The geomagnetic field, suitably scaled down and parameterized, is shown to give a very good fit to the magnetic field measurements taken on the first and third passes of the Mariner 10 space probe past Mercury. The excellence of the fit to a reliable planetary magnetospheric model is good evidence that the Mercury magnetosphere is formed by a simple, permanent, intrinsic planetary magnetic field distorted by the effects of the solar wind. The parameters used for a best fit to all the data are (depending slightly on the choice of data) 2.44--2.55 for the ratio of Mercury's magnetic field strength at the subsolar point to that of the earth's subsolar point field (this results in a dipole moment of 170 γR/sub M/ 3 (R/sub M/ is Mercury Radius), i.e., 2.41 x 10 22 G cm 3 in the same direction as the earth's dipole), approx.-113 γR/sub M/ 4 for the planetary quadrupole moment parallel to the dipole moment, 10degree--17degree for the tilt of the planet dipole toward the sun, 4.5degree for the tilt of the dipole toward dawn, and 2.5degree--7.6degree aberration angle for the shift in the tail axis from the planet-sun direction because of the planet's orbital velocity. The rms deviation overall for the entire data set compared with the theoretical fitted model for the magnetic field strength was 17 γ (approx.4% of the maximum field measured). If the data from the first pass that show presumed strong time variations are excluded, the overall rms deviation for the field magnitude is only 10 γ

  14. Magnetic field dosimeter development

    International Nuclear Information System (INIS)

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation

  15. DSM-5 field survey

    DEFF Research Database (Denmark)

    Lochner, Christine; Grant, Jon E; Odlaug, Brian Lawrence

    2012-01-01

    The aim of this multisite field survey was to examine the DSM-IV-TR criteria, proposed DSM-5 diagnostic criteria, as well as a number of possible additional diagnostic criteria, in patients with hair-pulling disorder (HPD, or trichotillomania).......The aim of this multisite field survey was to examine the DSM-IV-TR criteria, proposed DSM-5 diagnostic criteria, as well as a number of possible additional diagnostic criteria, in patients with hair-pulling disorder (HPD, or trichotillomania)....

  16. Collective field accelerator

    International Nuclear Information System (INIS)

    Luce, J.S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a ν/γ of approx. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam

  17. Controlling magnetic field profiles

    International Nuclear Information System (INIS)

    Freeman, J.R.

    1979-04-01

    A method for designing solenoid magnets with controlled field profiles is discussed. The method, originated by D.B. Montgomery, minimizes both the field errors and the power consumption. An NOS time-sharing computer program for the CDC-6600, entitled MAGCOR, was constructed to provide an interactive magnet design capability. Results obtained during the design of magnets for a radial line electron accelerator are presented. 9 figures

  18. Gauge field theories

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1981-01-01

    The book is intended to explain, in an elementary way, the basic notions and principles of gauge theories. Attention is centred on the Salem-Weinberg model of electro-weak interactions, as well as neutrino-lepton scattering and the parton model. Classical field theory, electromagnetic, Yang-Mills and gravitational gauge fields, weak interactions, Higgs mechanism and the SU(5) model of grand unification are also discussed. (U.K.)

  19. Radial Field Piezoelectric Diaphragms

    Science.gov (United States)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  20. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10 15 cm -3 . After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value

  1. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1979-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x10 15 cm -3 . After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)

  2. Magnetic field screens

    International Nuclear Information System (INIS)

    Mansfield, P.; Turner, R.; Chapman, B.L.W.; Bowley, R.M.

    1990-01-01

    A screen for a magnetic coil, for producing, for example, a homogeneous, gradient or RF field in nuclear magnetic resonance imaging, is described. It is provided by surround the coil with a set of electrical conductors. The currents within the conductors are controlled in such a manner that the field is neutralised in a specific region of space. The current distribution within the conductors is determined by calculating the current within a hypothetical superconductive shield which would have the effect of neutralising the field, the current through the conductors thereby being a substitute for the superconductive shield. The conductors may be evenly spaced and connected in parallel, their resistances being determined by thickness or composition to provide the desired current, or they may carry equal currents but be differently spaced. A further set or sets of controlled conductors outside the first set may ensure that the first set does not upset the field from the NMR coil. The shield may selectively reflect certain fields while transmitting others and may prevent acoustic vibration e.g. when switching gradient fields. An RF coil arrangement may consist of two orthogonal coils, one coil within the other for use as a transmit/receive set or as a double resonance transmitter; a shield between the coils is in series with, and formed from the same winding as, the inner coil. (author)

  3. Magnetic fields at Neptune

    International Nuclear Information System (INIS)

    Ness, N.F.; Acuna, M.H.; Burlaga, L.F.; Connerney, J.E.P.; Lepping, R.P.; Neubauer, F.M.

    1989-01-01

    The National Aeronautics and Space Administration Goddard Space Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong and complex intrinsic magnetic field of Neptune and an associated magnetosphere and magnetic tail. A maximum magnetic field of nearly 10,000 nanoteslas (1 nanotesla = 10 -5 gauss) was observed near closest approach, at a distance of 1.18 R N . The planetary magnetic field between 4 and 15 R N can be well represented by an offset tilted magnetic dipole (OTD), displaced from the center of Neptune by the surprisingly large amount of 0.55 R N and inclined by 47 degrees with respect to the rotation axis. Within 4 R N , the magnetic field representation must include localized sources or higher order magnetic multipoles, or both, which are not yet well determined. As the spacecraft exited the magnetosphere, the magnetic tail appeared to be monopolar, and no crossings of an imbedded magnetic field reversal or plasma neutral sheet were observed. The auroral zones are most likely located far from the rotation poles and may have a complicated geometry. The rings and all the known moons of Neptune are imbedded deep inside the magnetosphere, except for Nereid, which is outside when sunward of the planet. The radiation belts will have a complex structure owing to the absorption of energetic particles by the moons and rings of Neptune and losses associated with the significant changes in the diurnally varying magnetosphere configuration. In an astrophysical context, the magnetic field of Neptune, like that of Uranus, may be described as that of an oblique rotator

  4. Magnetic Fields Versus Gravity

    Science.gov (United States)

    Hensley, Kerry

    2018-04-01

    Deep within giant molecular clouds, hidden by dense gas and dust, stars form. Unprecedented data from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal the intricate magnetic structureswoven throughout one of the most massive star-forming regions in the Milky Way.How Stars Are BornThe Horsehead Nebulasdense column of gas and dust is opaque to visible light, but this infrared image reveals the young stars hidden in the dust. [NASA/ESA/Hubble Heritage Team]Simple theory dictates that when a dense clump of molecular gas becomes massive enough that its self-gravity overwhelms the thermal pressure of the cloud, the gas collapses and forms a star. In reality, however, star formation is more complicated than a simple give and take between gravity and pressure. Thedusty molecular gas in stellar nurseries is permeated with magnetic fields, which are thought to impede the inward pull of gravity and slow the rate of star formation.How can we learn about the magnetic fields of distant objects? One way is by measuring dust polarization. An elongated dust grain will tend to align itself with its short axis parallel to the direction of the magnetic field. This systematic alignment of the dust grains along the magnetic field lines polarizes the dust grains emission perpendicular to the local magnetic field. This allows us to infer the direction of the magnetic field from the direction of polarization.Magnetic field orientations for protostars e2 and e8 derived from Submillimeter Array observations (panels a through c) and ALMA observations (panels d and e). Click to enlarge. [Adapted from Koch et al. 2018]Tracing Magnetic FieldsPatrick Koch (Academia Sinica, Taiwan) and collaborators used high-sensitivity ALMA observations of dust polarization to learn more about the magnetic field morphology of Milky Way star-forming region W51. W51 is one of the largest star-forming regions in our galaxy, home to high-mass protostars e2, e8, and North.The ALMA observations reveal

  5. Theoretical physics. Field theory

    International Nuclear Information System (INIS)

    Landau, L.; Lifchitz, E.

    2004-01-01

    This book is the fifth French edition of the famous course written by Landau/Lifchitz and devoted to both the theory of electromagnetic fields and the gravity theory. The talk of the theory of electromagnetic fields is based on special relativity and relates to only the electrodynamics in vacuum and that of pointwise electric charges. On the basis of the fundamental notions of the principle of relativity and of relativistic mechanics, and by using variational principles, the authors develop the fundamental equations of the electromagnetic field, the wave equation and the processes of emission and propagation of light. The theory of gravitational fields, i.e. the general theory of relativity, is exposed in the last five chapters. The fundamentals of the tensor calculus and all that is related to it are progressively introduced just when needed (electromagnetic field tensor, energy-impulse tensor, or curve tensor...). The worldwide reputation of this book is generally allotted to clearness, to the simplicity and the rigorous logic of the demonstrations. (A.C.)

  6. Field error lottery

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C.J.; McVey, B. (Los Alamos National Lab., NM (USA)); Quimby, D.C. (Spectra Technology, Inc., Bellevue, WA (USA))

    1990-01-01

    The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.

  7. Multi-valued fields

    CERN Document Server

    Ershov, Yuri L

    2001-01-01

    For more than 30 years, the author has studied the model-theoretic aspects of the theory of valued fields and multi-valued fields. Many of the key results included in this book were obtained by the author whilst preparing the manuscript. Thus the unique overview of the theory, as developed in the book, has been previously unavailable. The book deals with the theory of valued fields and mutli-valued fields. The theory of Prüfer rings is discussed from the `geometric' point of view. The author shows that by introducing the Zariski topology on families of valuation rings, it is possible to distinguish two important subfamilies of Prüfer rings that correspond to Boolean and near Boolean families of valuation rings. Also, algebraic and model-theoretic properties of multi-valued fields with near Boolean families of valuation rings satisfying the local-global principle are studied. It is important that this principle is elementary, i.e., it can be expressed in the language of predicate calculus. The most important...

  8. Electromagnetic fields and cancer

    International Nuclear Information System (INIS)

    Singh, Neeta; Mathur, R.; Behari, J.

    1997-01-01

    Several studies in recent years have raised the possibility that exposure to electromagnetic fields (EMFs) may be hazardous to human health, in particular by promotion or initiation of cancer. Recent reports have indicated increased cancer risk from industrial and domestic exposure to environmental ELF fields and to RF fields that are amplitude modulated at ELF. EMF fields have been reported to affect biological systems in various ways, affecting changes in the morphology and or functional behavior of cells, which have been observed in a variety of tissues. Although the mechanism of interaction of EMFs with living cells are not known, it has been proposed that they have multiple effects and can affect cell signalling, including modification of plasma membrane permeability and ion transport. Our findings suggest that EMFs can affect post translational modification of proteins such as poly ADP-ribosylation by epigenetic mechanism and that the effect of EMFs are highly specific regarding both the cell type and the frequency and amplification of the applied field. (author)

  9. String field theory

    International Nuclear Information System (INIS)

    Kaku, M.

    1987-01-01

    In this article, the authors summarize the rapid progress in constructing string field theory actions, such as the development of the covariant BRST theory. They also present the newer geometric formulation of string field theory, from which the BRST theory and the older light cone theory can be derived from first principles. This geometric formulation allows us to derive the complete field theory of strings from two geometric principles, in the same way that general relativity and Yang-Mills theory can be derived from two principles based on global and local symmetry. The geometric formalism therefore reduces string field theory to a problem of finding an invariant under a new local gauge group they call the universal string group (USG). Thus, string field theory is the gauge theory of the universal string group in much the same way that Yang-Mills theory is the gauge theory of SU(N). The geometric formulation places superstring theory on the same rigorous group theoretical level as general relativity and gauge theory

  10. Cosmic magnetic fields

    CERN Document Server

    Kronberg, Philipp P

    2016-01-01

    Magnetic fields are important in the Universe and their effects contain the key to many astrophysical phenomena that are otherwise impossible to understand. This book presents an up-to-date overview of this fast-growing topic and its interconnections to plasma processes, astroparticle physics, high energy astrophysics, and cosmic evolution. The phenomenology and impact of magnetic fields are described in diverse astrophysical contexts within the Universe, from galaxies to the filaments and voids of the intergalactic medium, and out to the largest redshifts. The presentation of mathematical formulae is accessible and is designed to add insight into the broad range of topics discussed. Written for graduate students and researchers in astrophysics and related disciplines, this volume will inspire readers to devise new ways of thinking about magnetic fields in space on galaxy scales and beyond.

  11. Nonlocal quantum field theory

    International Nuclear Information System (INIS)

    Efimov, G.V.

    1976-01-01

    The basic ideas for creating the theory of nonlocal interactions of a scalar one-component field are presented. Lagrangian describing a non-interacting field is the ordinary one so that non-interacting particles are described by standard methods of the Fock space. Form factors introduced have been chosen from a class of analytic functionals and quantized. Conditions of microcausality have been considered in detail. The convergence of all integrals corresponding to the arbitrary Feynman diagrams in spinor electrodynamics is guaranteed in the frame of the rules formulated. It is noted in conclusion that the spinor electrodynamics with nonlocal interaction contains no ultraviolet divergencies and satisfies all the requirements of the quantum field theory; in this sense it is mathematically more consistent than its local version

  12. Collinear wake field acceleration

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Chen, P.; Wilson, P.B.

    1985-04-01

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  13. Gyrokinetic field theory

    International Nuclear Information System (INIS)

    Sugama, H.

    1999-08-01

    The Lagrangian formulation of the gyrokinetic theory is generalized in order to describe the particles' dynamics as well as the self-consistent behavior of the electromagnetic fields. The gyrokinetic equation for the particle distribution function and the gyrokinetic Maxwell's equations for the electromagnetic fields are both derived from the variational principle for the Lagrangian consisting of the parts of particles, fields, and their interaction. In this generalized Lagrangian formulation, the energy conservation property for the total nonlinear gyrokinetic system of equations is directly shown from the Noether's theorem. This formulation can be utilized in order to derive the nonlinear gyrokinetic system of equations and the rigorously conserved total energy for fluctuations with arbitrary frequency. (author)

  14. Electromagnetic fields and life

    CERN Document Server

    Presman, A S

    1970-01-01

    A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de­ creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also al­l most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio­ logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...

  15. Electromagnetic fields and waves

    CERN Document Server

    Iskander, Magdy F

    2013-01-01

    The latest edition of Electromagnetic Fields and Waves retains an authoritative, balanced approach, in-depth coverage, extensive analysis, and use of computational techniques to provide a complete understanding of electromagnetic—important to all electrical engineering students. An essential feature of this innovative text is the early introduction of Maxwell's equations, together with the quantifying experimental observations made by the pioneers who discovered electromagnetics. This approach directly links the mathematical relations in Maxwell's equations to real experiments and facilitates a fundamental understanding of wave propagation and use in modern practical applications, especially in today's wireless world. New and expanded topics include the conceptual relationship between Coulomb's law and Gauss's law for calculating electric fields, the relationship between Biot-Savart's and Ampere's laws and their use in calculating magnetic fields from current sources, the development of Faraday's law from e...

  16. Supersymmetric gauge field theories

    International Nuclear Information System (INIS)

    Slavnov, A.A.

    1976-01-01

    The paper is dealing with the role of supersymmetric gauge theories in the quantum field theory. Methods of manipulating the theories as well as possibilities of their application in elementary particle physics are presented. In particular, the necessity is explained of a theory in which there is symmetry between Fermi and Bose fields, in other words, of the supersymmetric gauge theory for construction of a scheme for the Higgs particle connecting parameters of scalar mesons with those of the rest fields. The mechanism of supersymmetry breaking is discussed which makes it possible to remain the symmetric procedure of renormalization intact. The above mechanism of spontaneous symmetry breaking is applied to demonstrate possibilities of constructing models of weak and electromagnetic interactions which would be acceptable from the point of view of experiments. It is noted that the supersymmetric gauge theories represent a natural technique for description of vector-like models

  17. Reversed field pinch experiments

    International Nuclear Information System (INIS)

    Roberston, S.

    1991-05-01

    The Reversatron RFP is usually operated with toroidal field windings which are a continuous helix of 144 turns. These windings produce a poloidal current which is uniform around the torus. The distribution of current is fixed by the geometry so that the applied field has only an m = 0, n = 0 component. The windings cannot act to stabilize an m = 0 mode with |n| > 0 or any m = 1 mode because these modes will excite no current in the windings. It has recently been suggested that parallel connected field coils might act as a shell by forcing the flux within each winding to be the same. Coils connected in parallel must have the same voltage at their terminals and thus must enclose the same volt-seconds or flux. Data from ZT-40 show that the discharges are more quiescent when parallel or series-parallel connected windings are used

  18. Energy of the field for the field

    International Nuclear Information System (INIS)

    2001-01-01

    Considering the problems that are presented in the field related with the lack of available energy is presented, the Biogas like energy alternative. This is a resulting product of the fermentation anaerobic (without air) of the organic residuals under appropriate conditions of humidity. It is a mixture of gases in which they prevail: Methane (CH 4 ) in a 55 to 70 percent, Dioxide of Carbon (CO 2 ) in a 28 to 43 percent and others as the hydro sulphide by 2 percent. The composition of the biogas depends of: the quality of the used material, of the biodigestor type, of the ambient temperature, of the adopted time of retention. Some of the advantages of the use of this alternative are: better sanitary conditions in the rural means. Decrease in the consumption of inorganic fertilizers. Increase of the agricultural productivity with the employment of the Bio fertilizing (20/25 bigger percent) in comparison with the fresh manure; conservation of natural resources as fuels, fossils and firewood; energy production in the own local consumption. Perfect ecological solution for the obtaining of renewable energy and bio fertilizing

  19. Microcanonical quantum field theory

    International Nuclear Information System (INIS)

    Strominger, A.

    1983-01-01

    Euclidean quantum field theory is equivalent to the equilibrium statistical mechanics of classical fields in 4+1 dimensions at temperature h. It is well known in statistical mechanics that the theory of systems at fixed temperature is embedded within the more general and fundamental theory of systems at fixed energy. We therefore develop, in precise analogy, a fixed action (macrocanonical) formulation of quantum field theory. For the case of ordinary renormalizable field theories, we show (with one exception) that the microcanonical is entirely equivalent to the canonical formulation. That is, for some particular fixed value of the total action, the Green's functions of the microcanonical theory are equal, in the bulk limit, to those of the canonical theory. The microcanonical perturbation expansion is developed in some detail for lambdaphi 4 . The particular value of the action for which the two formulations are equivalent can be calculated to all orders in perturbation theory. We prove, using Lehmann's Theorem, that this value is one-half Planck unit per degree of freedom, if fermionic degrees of freedom are counted negatively. This is the 4+1 dimensional analog of the equipartition theorem. The one exception to this is supersymmetric theories. A microcanonical formulation exists if and only if supersymmetry is broken. In statistical mechanics and in field theory there are systems for which the canonical description is pathological, but the microcanonical is not. An example of such a field theory is found in one dimension. A semiclassical expansion of the microcanonical theory is well defined, while an expansion of the canonical theory is hoplessly divergent

  20. Tripolar electric field Structure in guide field magnetic reconnection

    Science.gov (United States)

    Fu, Song; Huang, Shiyong; Zhou, Meng; Ni, Binbin; Deng, Xiaohua

    2018-03-01

    It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

  1. Tripolar electric field Structure in guide field magnetic reconnection

    Directory of Open Access Journals (Sweden)

    S. Fu

    2018-03-01

    Full Text Available It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection. In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg. Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

  2. Quaternionic quantum field theory

    International Nuclear Information System (INIS)

    Adler, S.L.

    1986-01-01

    In this paper the author describes a new kind of quantum mechanics or quantum field theory based on quaternions. Quaternionic quantum mechanics has a Schrodinger equation, a Dirac transformation theory, and a functional integral. Quaternionic quantum mechanics does not seem to have (except in the complex quantum mechanics specialization): A correspondence principle, and beyond this a commuting tensor product, asymptotic states, an S-matrix, a canonical formalism, coherent states or a Euclidean continuation. A new kind of quantum mechanics exists. There are many interesting formal questions to study, which should enable one to decide whether quaternionic quantum field theory is relevant for particle physics

  3. Quantum field theory

    CERN Document Server

    Mandl, Franz

    2010-01-01

    Following on from the successful first (1984) and revised (1993) editions, this extended and revised text is designed as a short and simple introduction to quantum field theory for final year physics students and for postgraduate students beginning research in theoretical and experimental particle physics. The three main objectives of the book are to: Explain the basic physics and formalism of quantum field theory To make the reader proficient in theory calculations using Feynman diagrams To introduce the reader to gauge theories, which play a central role in elementary particle physic

  4. Field studies courses open

    Science.gov (United States)

    Fourteen month-long courses combining applied academics with training in field research methodology are being offered this summer by the School for Field Studies. The courses, held in eight countries during May, June, July, and August, provide unique opportunities for participants to work as a team under primitive conditions.‘Our courses bind together the academic challenge of the research problem, the physical challenge of the site itself, and the interpersonal challenge of the expedition team in a dynamic way so that both cognitive and affective learning are accelerated,’ according to Jim Elder, the school's director.

  5. WORKSHOP: Thermal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-04-15

    The early history of the Universe is a crucial testing ground for theories of elementary particles. Speculative ideas about the constituents of matter and their interactions are reinforced if they are consistent with what we suppose happened near the beginning of time and discarded if they are not. The cosmological consequences of these theories are usually deduced using a general statistical approach called thermal field theory. Thus, 75 physicists from thirteen countries met in Cleveland, Ohio, last October for the first 'Workshop on Thermal Field Theories and their Applications'.

  6. Gauge field theories

    International Nuclear Information System (INIS)

    Pokorski, S.

    1987-01-01

    Quantum field theory forms the present theoretical framework for the understanding of the fundamental interactions of particle physics. This book examines gauge theories and their symmetries with an emphasis on their physical and technical aspects. The author discusses field-theoretical techniques and encourages the reader to perform many of the calculations presented. This book includes a brief introduction to perturbation theory, the renormalization programme, and the use of the renormalization group equation. Several topics of current research interest are covered, including chiral symmetry and its breaking, anomalies, and low energy effective lagrangians and some basics of supersymmetry

  7. Finite temperature field theory

    CERN Document Server

    Das, Ashok

    1997-01-01

    This book discusses all three formalisms used in the study of finite temperature field theory, namely the imaginary time formalism, the closed time formalism and thermofield dynamics. Applications of the formalisms are worked out in detail. Gauge field theories and symmetry restoration at finite temperature are among the practical examples discussed in depth. The question of gauge dependence of the effective potential and the Nielsen identities are explained. The nonrestoration of some symmetries at high temperature (such as supersymmetry) and theories on nonsimply connected space-times are al

  8. Interpolating string field theories

    International Nuclear Information System (INIS)

    Zwiebach, B.

    1992-01-01

    This paper reports that a minimal area problem imposing different length conditions on open and closed curves is shown to define a one-parameter family of covariant open-closed quantum string field theories. These interpolate from a recently proposed factorizable open-closed theory up to an extended version of Witten's open string field theory capable of incorporating on shell closed strings. The string diagrams of the latter define a new decomposition of the moduli spaces of Riemann surfaces with punctures and boundaries based on quadratic differentials with both first order and second order poles

  9. Gela offshore field

    Energy Technology Data Exchange (ETDEWEB)

    Pagliughi, G

    1965-06-01

    The field of Gela, off the southern shore of Sicily, is the only producing offshore field in the Mediterranean. It produces from Triassic dolimite limestones of 434-m thickness, water level at -3517 m. It is a water-drive reservoir producing 10/sup 0/F API oil and has 79 wells, some of them on shore. Most offshore wells are directional wells from shore; there are also 2 fixed platforms and a special mobile platform. The wells are on pump (stroke, 72 in.; capacity 200 tons per day). The crude goes directly to a combination refinery-petrochemical complex at Gela.

  10. DSM-5 field survey

    DEFF Research Database (Denmark)

    Lochner, Christine; Grant, Jon E; Odlaug, Brian Lawrence

    2012-01-01

    Pathologic skin picking (skin picking disorder [SPD]) is a prevalent and disabling condition, which has received increasing study. It is timely to consider including SPD in DSM-5. The aim of this field survey was to investigate possible diagnostic criteria for SPD.......Pathologic skin picking (skin picking disorder [SPD]) is a prevalent and disabling condition, which has received increasing study. It is timely to consider including SPD in DSM-5. The aim of this field survey was to investigate possible diagnostic criteria for SPD....

  11. Finite quantum field theories

    International Nuclear Information System (INIS)

    Lucha, W.; Neufeld, H.

    1986-01-01

    We investigate the relation between finiteness of a four-dimensional quantum field theory and global supersymmetry. To this end we consider the most general quantum field theory and analyse the finiteness conditions resulting from the requirement of the absence of divergent contributions to the renormalizations of the parameters of the theory. In addition to the gauge bosons, both fermions and scalar bosons turn out to be a necessary ingredient in a non-trivial finite gauge theory. In all cases discussed, the supersymmetric theory restricted by two well-known constraints on the dimensionless couplings proves to be the unique solution of the finiteness conditions. (Author)

  12. On vector fields having properties of Reeb fields

    OpenAIRE

    Hajduk, Boguslaw; Walczak, Rafal

    2011-01-01

    We study constructions of vector fields with properties which are characteristic to Reeb vector fields of contact forms. In particular, we prove that all closed oriented odd-dimensional manifold have geodesible vector fields.

  13. Electromagnetic fields and their impacts

    Science.gov (United States)

    Prša, M. A.; Kasaš-Lažetić, K. K.

    2018-01-01

    The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

  14. Tripolar electric field Structure in guide field magnetic reconnection

    OpenAIRE

    S. Fu; S. Huang; M. Zhou; B. Ni; X. Deng

    2018-01-01

    It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplit...

  15. Electromagnetic Fields and Cancer

    Science.gov (United States)

    ... and magnetic fields (1 Hz to 100 kHz) . Health Physics 2010; 99(6):818-36. doi: 10.1097/ ... and health: review of current status of research. Health Physics 2013; 105(6):561-75. [PubMed Abstract] AGNIR. ...

  16. Ultrasonogram in obstetric field

    International Nuclear Information System (INIS)

    Joo, K. B.; Song, C. H.; Lee, H. B.

    1980-01-01

    The clinical evaluation of 535 cases of sonogram from Mar. 1, 1979 to Oct. 30, 1979 in obstetric field at Department of Radiology and Ob. and Gy. Eul-Ji General Hospital. We present these cases: normal pregnancy, missed abortion, twin pregnancy, hydatidiform mole and ectopic pregnancy, with brief review of literature.

  17. Linking lab and field

    International Nuclear Information System (INIS)

    Cronje, P.B.

    1988-01-01

    The multitude of different supplements recommended for animals grazing natural pastures, which testifies to the need for a metabolic basis for supplementary feeding practices. The first approach to this problem was to simulate different feeding conditions in the laboratory, where the metabolic responses of body tissues to changes in the supply of purified nutrients could be studied using radioisotope techniques. The second step was to link these fundamental studies to field conditions. The results of these studies suggest that the efficiency of feed conversion and growth rates of ruminants grazing winter pastures in the highveld region of South Africa could be substantially improved by strategic supplementation with glucose precursors. Acetate clearance rate represents a valuable link in the process of applying information obtained from controlled laboratory experiments to field conditions. As this technique is inexpensive, quick and simple to carry out, it is ideally suited to application under field conditions where the use of isotopes is impractical. By providing a link with field conditions, it greatly extended the scope and practical application of isotope tracer techniques

  18. Warp Field Mechanics 101

    Science.gov (United States)

    White, Harold

    2011-01-01

    This paper will begin with a short review of the Alcubierre warp drive metric and describes how the phenomenon might work based on the original paper. The canonical form of the metric was developed and published in [6] which provided key insight into the field potential and boost for the field which remedied a critical paradox in the original Alcubierre concept of operations. A modified concept of operations based on the canonical form of the metric that remedies the paradox is presented and discussed. The idea of a warp drive in higher dimensional space-time (manifold) will then be briefly considered by comparing the null-like geodesics of the Alcubierre metric to the Chung-Freese metric to illustrate the mathematical role of hyperspace coordinates. The net effect of using a warp drive technology coupled with conventional propulsion systems on an exploration mission will be discussed using the nomenclature of early mission planning. Finally, an overview of the warp field interferometer test bed being implemented in the Advanced Propulsion Physics Laboratory: Eagleworks (APPL:E) at the Johnson Space Center will be detailed. While warp field mechanics has not had a Chicago Pile moment, the tools necessary to detect a modest instance of the phenomenon are near at hand.

  19. Parafermionic conformal field theory

    International Nuclear Information System (INIS)

    Kurak, V.

    1989-09-01

    Conformal parafermionic field theories are reviewed with emphasis on the computation of their OPE estructure constants. It is presented a simple computational of these for the Z(N) parafermions, unveilling their Lie algebra content. (A.C.A.S.) [pt

  20. What Are Electromagnetic Fields?

    Science.gov (United States)

    ... field causes a compass needle to orient in a North-South direction and is used by birds and fish for navigation. Human-made sources of ... and form the basis of telecommunications as well as radio and television ... In microwaves ovens, we use them to quickly heat food. At ...

  1. Superspace conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Quella, Thomas [Koeln Univ. (Germany). Inst. fuer Theoretische Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-15

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  2. Superspace conformal field theory

    International Nuclear Information System (INIS)

    Quella, Thomas

    2013-07-01

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  3. Field Guide to Radiometry

    CERN Document Server

    Grant, Barbara

    2011-01-01

    Written from a systems engineering perspective, this SPIE Field Guide covers topics in optical radiation propagation, material properties, sources, detectors, system components, measurement, calibration, and photometry. The book's organization and extensive collection of diagrams, tables, and graphs will enable the reader to efficiently identify and apply relevant information to radiometric problems arising amid the demands of today's fast-paced technical environment.

  4. Field ion microscopy

    International Nuclear Information System (INIS)

    Ramanathan, D.

    1975-01-01

    The basic features of the Field-Ion Microscope (FIM) and the theory of image formation are explained. Design parameters of the FIM, factors limiting its resolution, interpretation of the image, etc are briefly outlined. Relative merits of the various imaging gases and the applications of the FIM are also covered. (K.B.)

  5. Planetary plasmas and fields

    International Nuclear Information System (INIS)

    Roederer, J.G.

    1976-01-01

    The magnetospheres of earth, Jupiter, and Mercury are discussed. The main features and physical processes characteristic of the quiet time earth magnetosphere are examined. Jupiter's larger and more distant magnetosphere is compared with the earth's and recent findings are reviewed. The plasma and field environment of Mercury is also discussed and similarities with the earth's magnetosphere are noted

  6. Reflections on the Field.

    Science.gov (United States)

    Kauffman, James M.

    2003-01-01

    Reflections on the field of special education offer six ideas: (1) the value of science; (2) the continuing value of separate and special education for some students; (3) the continuing importance of prevention; (4) the importance of academic instruction; (5) the importance of social justice for the poor; and (6) a renewed emphasis on human…

  7. Axiomatic conformal field theory

    International Nuclear Information System (INIS)

    Gaberdiel, M.R.; Goddard, P.

    2000-01-01

    A new rigourous approach to conformal field theory is presented. The basic objects are families of complex-valued amplitudes, which define a meromorphic conformal field theory (or chiral algebra) and which lead naturally to the definition of topological vector spaces, between which vertex operators act as continuous operators. In fact, in order to develop the theory, Moebius invariance rather than full conformal invariance is required but it is shown that every Moebius theory can be extended to a conformal theory by the construction of a Virasoro field. In this approach, a representation of a conformal field theory is naturally defined in terms of a family of amplitudes with appropriate analytic properties. It is shown that these amplitudes can also be derived from a suitable collection of states in the meromorphic theory. Zhu's algebra then appears naturally as the algebra of conditions which states defining highest weight representations must satisfy. The relationship of the representations of Zhu's algebra to the classification of highest weight representations is explained. (orig.)

  8. NPOESS Field Terminal Updates

    Science.gov (United States)

    Heckmann, G.; Route, G.

    2009-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to NOAA and DoD processing centers operated by the United States government. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. IDPS also provides the software and requirements for the Field Terminal Segment (FTS). NPOESS provides support to deployed field terminals by providing mission data in the Low Rate and High Rate downlinks (LRD/HRD), mission support data needed to generate EDRs and decryption keys needed to decrypt mission data during Selective data Encryption (SDE). Mission support data consists of globally relevant data, geographically constrained data, and two line element sets. NPOESS provides these mission support data via the Internet accessible Mission Support Data Server and HRD/LRD downlinks. This presentation will illustrate and describe the NPOESS capabilities in support of Field Terminal users. This discussion will include the mission support data available to Field Terminal users, content of the direct broadcast HRD and LRD

  9. Gravitational Field Shielding by Scalar Field and Type II Superconductors

    Directory of Open Access Journals (Sweden)

    Zhang B. J.

    2013-01-01

    Full Text Available The gravitational field shielding by scalar field and type II superconductors are theoret- ically investigated. In accord with the well-developed five-dimensional fully covariant Kaluza-Klein theory with a scalar field, which unifies the Einsteinian general relativity and Maxwellian electromagnetic theory, the scalar field cannot only polarize the space as shown previously, but also flatten the space as indicated recently. The polariza- tion of space decreases the electromagnetic field by increasing the equivalent vacuum permittivity constant, while the flattening of space decreases the gravitational field by decreasing the equivalent gravitational constant. In other words, the scalar field can be also employed to shield the gravitational field. A strong scalar field significantly shield the gravitational field by largely decreasing the equivalent gravitational constant. According to the theory of gravitational field shielding by scalar field, the weight loss experimentally detected for a sample near a rotating ceramic disk at very low tempera- ture can be explained as the shielding of the Earth gravitational field by the Ginzburg- Landau scalar field, which is produced by the type II superconductors. The significant shielding of gravitational field by scalar field produced by superconductors may lead to a new spaceflight technology in future.

  10. Evaluate existing radiation fields

    International Nuclear Information System (INIS)

    Aldrich, J.M.; Haggard, D.L.; Endres, G.W.R.; Fix, J.J.

    1981-01-01

    Knowledge of the spectrum of energies for beta, gamma, and neutron radiation experienced in the field is crucial to the proper interpretation of personnel dose. Calibration sources and techniques are determined on the basis of their relationship to field exposure. Selected techniques were used to obtain neutron, photon, and beta energy spectra data at several Hanford locations. Four neutron energy spectra and dose measurement methods were used: (1) multisphere spectrometer system; (2) tissue equivalent proportional counter (TEPC); (3) RASCAL (9'' to 3'' sphere ratios); and (4) helium-3 neutron spectrometer. Gamma spectroscopy was done using standard techniques. A specially designed TLD dosimeter was used to obtain beta spectrum measurements. The design and use of each of these instruments is described in the body of this report. Data collected and analyzed for each of the Hanford locations are included

  11. Algebraic quantum field theory

    International Nuclear Information System (INIS)

    Foroutan, A.

    1996-12-01

    The basic assumption that the complete information relevant for a relativistic, local quantum theory is contained in the net structure of the local observables of this theory results first of all in a concise formulation of the algebraic structure of the superselection theory and an intrinsic formulation of charge composition, charge conjugation and the statistics of an algebraic quantum field theory. In a next step, the locality of massive particles together with their spectral properties are wed for the formulation of a selection criterion which opens the access to the massive, non-abelian quantum gauge theories. The role of the electric charge as a superselection rule results in the introduction of charge classes which in term lead to a set of quantum states with optimum localization properties. Finally, the asymptotic observables of quantum electrodynamics are investigated within the framework of algebraic quantum field theory. (author)

  12. Fisheyes in the field

    DEFF Research Database (Denmark)

    Jakobsen, Mikkel Rønne; Hornbæk, Kasper Anders Søren

    2009-01-01

    multiple methods (experience sampling, logging, thinking aloud, and interviews) to describe how the visualization is adopted and used. At the concrete level, our results suggest that the visualization was used as frequently as other tools in the programming environment. We also propose extensions......Information visualizations have been shown useful in numerous laboratory studies, but their adoption and use in real-life tasks are curiously under-researched. We present a field study of ten programmers who work with an editor extended with a fisheye view of source code. The study triangulates...... to the interface and discuss features that were not used in practice. At the methodological level, the study identifies contributions distinct to individual methods and to their combination, and discusses the relative benefits of laboratory studies and field studies for the evaluation of information visualizations....

  13. Field services experiences

    International Nuclear Information System (INIS)

    Colflesh, J.A.; Kruse, P.W.; Merluzzi, R.A.

    1985-01-01

    Combustion Engineering (C-E) is a large diversified manufacturer of products and services for the energy field. At this time, C-E has supplied the nuclear steam supply systems for eleven operating nuclear power plants with two additional units currently undergoing start-up testing. The focus of C-E's commitment in the nuclear power plant services area is the Nuclear Services organization within the Nuclear Power Systems Division. The Nuclear Services organization provides services on a timely cost efficient basis; and dedicates resources to developing new products and services which are truly responsive to the needs of operating power plants world wide. In the paper, C-E's capabilities and experience in the field of nuclear services are described. Highlighted are our capabilities in the areas of transition management services, operating services and engineering services

  14. Quantum field theory

    International Nuclear Information System (INIS)

    Mancini, F.

    1986-01-01

    Theoretical physicists, coming from different countries, working on different areas, gathered at Positano: the Proceedings contain all the lectures delivered as well as contributed papers. Many areas of physics are represented, elementary particles in high energy physics, quantum relativity, quantum geometry, condensed matter physics, statistical mechanics; but all works are concerned with the use of the methods of quantum field theory. The first motivation of the meeting was to pay homage to a great physicist and a great friend; it was also an occasion in which theoretical physicists got together to discuss and to compare results in different fields. The meeting was very intimate; the relaxed atmosphere allowed constructive discussions and contributed to a positive exchange of ideas. (orig.)

  15. Geologic Field Database

    Directory of Open Access Journals (Sweden)

    Katarina Hribernik

    2002-12-01

    Full Text Available The purpose of the paper is to present the field data relational database, which was compiled from data, gathered during thirty years of fieldwork on the Basic Geologic Map of Slovenia in scale1:100.000. The database was created using MS Access software. The MS Access environment ensures its stability and effective operation despite changing, searching, and updating the data. It also enables faster and easier user-friendly access to the field data. Last but not least, in the long-term, with the data transferred into the GISenvironment, it will provide the basis for the sound geologic information system that will satisfy a broad spectrum of geologists’ needs.

  16. Transmission line fields

    International Nuclear Information System (INIS)

    Jeffers, D.E.

    1991-01-01

    There were reports from Russia in the late 1960's and early 1970's that staff in new 500-kV and 750-kV substations were suffering from headaches and other symptoms broadly associated with fatigue. Whilst the Russian results were not confirmed by independent studies, they did serve to stimulate public concern. In 1979 published results of a study of childhood cancer in Denver, Colorado concentrated attention onto the magnetic rather than the electric field. Research programmes in the United Kingdom and elsewhere are briefly described. Although some studies suggest an association between exposure to 50/60 Hz fields and cancer, other studies do not. Having reviewed the evidence, the International Radiation Protection Association, the World Health Organisation, the U.S. Congress Office of Technology Assessment and the U.K. National Radiological Protection Board all consider that the relation is not established. (author)

  17. Quantum Field Theory

    CERN Document Server

    Zeidler, Eberhard

    This is the first volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists ranging from advanced undergraduate students to professional scientists. The book tries to bridge the existing gap between the different languages used by mathematicians and physicists. For students of mathematics it is shown that detailed knowledge of the physical background helps to motivate the mathematical subjects and to discover interesting interrelationships between quite different mathematical topics. For students of physics, fairly advanced mathematics is presented, which is beyond the usual curriculum in physics. It is the author's goal to present the state of the art of realizing Einstein's dream of a unified theory for the four fundamental forces in the universe (gravitational, electromagnetic, strong, and weak interaction). From the reviews: "… Quantum field theory is one of the great intellectual edifices in the history of human thought. … This volume differs from othe...

  18. Particles and quantum fields

    CERN Document Server

    Kleinert, Hagen

    2016-01-01

    This is an introductory book on elementary particles and their interactions. It starts out with many-body Schrödinger theory and second quantization and leads, via its generalization, to relativistic fields of various spins and to gravity. The text begins with the best known quantum field theory so far, the quantum electrodynamics of photon and electrons (QED). It continues by developing the theory of strong interactions between the elementary constituents of matter (quarks). This is possible due to the property called asymptotic freedom. On the way one has to tackle the problem of removing various infinities by renormalization. The divergent sums of infinitely many diagrams are performed with the renormalization group or by variational perturbation theory (VPT). The latter is an outcome of the Feynman-Kleinert variational approach to path integrals discussed in two earlier books of the author, one representing a comprehensive treatise on path integrals, the other dealing with critial phenomena. Unlike ordin...

  19. Wake field acceleration experiments

    International Nuclear Information System (INIS)

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics? I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs

  20. ISR Radial Field Magnet

    CERN Multimedia

    1983-01-01

    There were 37 (normal) + 3 (special) Radial Field magnets in the ISR to adjust vertically the closed orbit. Gap heights and strengths were 200 mm and .12 Tm in the normal magnets, 220 mm and .18 Tm in the special ones. The core length was 430 mm in both types. Due to their small length as compared to the gap heights the end fringe field errors were very important and had to be compensated by suitably shaping the poles. In order to save on cables, as these magnets were located very far from their power supplies, the coils of the normal type magnets were formed by many turns of solid cpper conductor with some interleaved layers of hollow conductor directly cooled by circulating water

  1. Education as "Dilemmatic Field"

    DEFF Research Database (Denmark)

    Tateo, Luca

    2018-01-01

    Psychology of education must discuss a number of relevant ethical, political and societal issues that cannot be simply overlooked as non pertinent to the discipline. For too long educational and developmental psychology have take divergent routes and have not enough dialogued with other fields...... such as pedagogy. I argue that it is first of all necessary to conceptualize the work of schooling, that is educational processes of teaching and learning in specific social contexts, as complex and dilemmatic fields. I discuss contributions from the past and current debate to support my claim that education...... is inherently ambivalent and dilemmatic, while educational psychology is too often normative and prescriptive. As many authors have discussed educational processes as battlefields between political and economic tendencies, we cannot avoid to discuss the relationship of such tendencies and the developmental...

  2. On Scale and Fields

    DEFF Research Database (Denmark)

    Kadish, David

    2017-01-01

    This paper explores thematic parallels between artistic and agricultural practices in the postwar period to establish a link to media art and cultural practices that are currently emerging in urban agriculture. Industrial agriculture has roots in the post-WWII abundance of mechanical and chemical...... equipment and research. These systems are highly mechanically efficient. With minimal physical labour, they extract ever staggering crop yields from ever poorer soils in shifting climatic conditions. However, the fact of mechanical efficiency is used to mask a set of problems with industrial......-scale agricultural systems that range from spreading pests and diseases to poor global distribution of concentrated regional food wealth. That the conversion of vegetatively diverse farmland into monochromatic fields was popularized at the same time as the arrival of colour field paintings like Barnett Newman...

  3. Microcontinuum field theories

    CERN Document Server

    Eringen, A Cemal

    1999-01-01

    Microcontinuum field theories constitute an extension of classical field theories -- of elastic bodies, deformations, electromagnetism, and the like -- to microscopic spaces and short time scales. Material bodies are here viewed as collections of large numbers of deformable particles, much as each volume element of a fluid in statistical mechanics is viewed as consisting of a large number of small particles for which statistical laws are valid. Classical continuum theories are valid when the characteristic length associated with external forces or stimuli is much larger than any internal scale of the body under consideration. When the characteristic lengths are comparable, however, the response of the individual constituents becomes important, for example, in considering the fluid or elastic properties of blood, porous media, polymers, liquid crystals, slurries, and composite materials. This volume is concerned with the kinematics of microcontinua. It begins with a discussion of strain, stress tensors, balanc...

  4. Effective quantum field theories

    International Nuclear Information System (INIS)

    Georgi, H.M.

    1989-01-01

    Certain dimensional parameters play a crucial role in the understanding of weak and strong interactions based on SU(2) x U(1) and SU(3) symmetry group theories and of grand unified theories (GUT's) based on SU(5). These parameters are the confinement scale of quantum chromodynamics and the breaking scales of SU(2) x U(1) and SU(5). The concepts of effective quantum field theories and renormalisability are discussed with reference to the economics and ethics of research. (U.K.)

  5. Noncommutative field theory

    International Nuclear Information System (INIS)

    Douglas, Michael R.; Nekrasov, Nikita A.

    2001-01-01

    This article reviews the generalization of field theory to space-time with noncommuting coordinates, starting with the basics and covering most of the active directions of research. Such theories are now known to emerge from limits of M theory and string theory and to describe quantum Hall states. In the last few years they have been studied intensively, and many qualitatively new phenomena have been discovered, on both the classical and the quantum level

  6. Energy from field crops

    Energy Technology Data Exchange (ETDEWEB)

    Zubr, J.

    1990-04-15

    At the Research Station of Royal Veterinary and Agricultural University, Copenhagen, Denmark, investigation concerning cultivation and exploitation of field crops for production of fuels was carried out during the period 1986-1989. High yielding crops, such as sugar beet - BETA VULGARIS, jerusalem artichoke - HELIANTHUS TUBEROSUS, rhubarb - RHEUM RHAPONTICUM, and comfrey - SYMPHYTUM ASPERUM, were grown experimentally in the field. Different cultivation methods for the crops were used and evaluated. Simultaneously with the field experiment, laboratory investigation was carried out to determine the energy potential of different products and by-products from the crops processes, such as alcoholic and methanogenic fermantation. Production expenses for the crops were determined, and cost of the fuels was estimated. The experimental results show that beet is a superior crop for the climatic conditions of Northern Europe. In the season 1986, yields exceeded 20 t TS/ha in the form of roots and tops, where achieved. A combined exploitation of beet roots and tops via alcoholic and methanogenic fermantation gave a gross energy corresponding to 80 hl OE/ha/yr. Using methanogenic fermentation exclusively, from ensiled beet roots and tops, gross energy yield corresponding to 85 hl IE/ha/yr, was achieved. The cost of energy in the form of alcohol from beet roots was estimated to be 5.17 DKK/1 OE (0.64 ECU/l OE). The cost of energy in the form of methane from ensiled beet tops, was estimated to be 2.68 DKK/l OE (0.33 ECU/l OE). At the present time, methane produced on the basis of ensiled beet roots and tops appears to be competitive with fossil fuels. Irrespective of the cost, however, the possibility of producing clean energy from field crops remains of interest for the future. (author) 27 refs.

  7. Quantized gauge field

    International Nuclear Information System (INIS)

    Arodz, H.

    1987-01-01

    The two formulations of quantum theory of the free electromagnetic field are presented. In the Coulomb gauge approach the independent dynamical variables have been identified and then, in order to quantize the theory, it has been sufficient to apply the straightforward canonical quantization. In the Gupta-Bleuler approach the auxilliary theory is first considered. The straightforward canonical quantization of it leads to the quantum theory defined in the space G with indefinite norm. 15 refs. (author)

  8. Affine field theories

    International Nuclear Information System (INIS)

    Cadavid, A.C.

    1989-01-01

    The author constructs a non-Abelian field theory by gauging a Kac-Moody algebra, obtaining an infinite tower of interacting vector fields and associated ghosts, that obey slightly modified Feynman rules. She discusses the spontaneous symmetry breaking of such theory via the Higgs mechanism. If the Higgs particle lies in the Cartan subalgebra of the Kac-Moody algebra, the previously massless vectors acquire a mass spectrum that is linear in the Kac-Moody index and has additional fine structure depending on the associated Lie algebra. She proceeds to show that there is no obstacle in implementing the affine extension of supersymmetric Yang-Mills theories. The result is valid in four, six and ten space-time dimensions. Then the affine extension of supergravity is investigated. She discusses only the loop algebra since the affine extension of the super-Poincare algebra appears inconsistent. The construction of the affine supergravity theory is carried out by the group manifold method and leads to an action describing infinite towers of spin 2 and spin 3/2 fields that interact subject to the symmetries of the loop algebra. The equations of motion satisfy the usual consistency check. Finally, she postulates a theory in which both the vector and scalar fields lie in the loop algebra of SO(3). This theory has an expanded soliton sector, and corresponding to the original 't Hooft-Polyakov solitonic solutions she now finds an infinite family of exact, special solutions of the new equations. She also proposes a perturbation method for obtaining an arbitrary solution of those equations for each level of the affine index

  9. Mobile Field Goniospectrometry

    Science.gov (United States)

    Peltoniemi, J. I.; Kaasalainen, S.; Näränen, J.

    2004-05-01

    Multiangle remote sensing needs multiangle models and multiangle ground reference data. The ground data can be measured using goniometers. Many targets are in difficult terrains and hard to bring into laboratory, which makes the ground data collection more complicated We have developed several field goniometers to measure the directional and spectral reflection signatures of various targets. The heaviest of the instruments is fully manual and very robust for field work. It can be transported using a light trailer and mounted in an hour. The new very light goniometer measures the BRDF automatically in few minutes. It can be carried by two persons even large distances to difficult places. Both of these instruments use the ASD Field Spec PRO FR spectrometer with a 4m light fibre allowing optics to be mounted up and the heavy parts down. The dimensions --- arm length about 2m --- and optics (1--8 degree view angles) limit the useful spot diameter to about 3, 10 or 30cm, making the system useful for small vegetation and soil. These two wide angle goniometers are complemented by a narrow angle backscattering goniometer utilising beamsplitters to measure up to exact backscattering direction and about 15 degree around. We present BRDF and spectra for undergrowth (lichen, moss, peat, twigs) from a field campaign in August 2003, and various grasses dry and wet. We recognise significant differences in the directional pattern between different species (factors of 2-10) and varying structural properties, making the use of directional signal for remote sensing very attractive. We are working with scattering models of snow and soil, and will continue with vegetation soon.

  10. Particles, fields, Universe

    International Nuclear Information System (INIS)

    Zeldovich, Ya. B.

    1984-01-01

    A general review is given on the historical development and on the present status of main physical ideas and theories. The concepts of particles, fields and interactions are discussed in detail including most recent developments. The present basic theories of physics: general relativity, gauge theory of electroweak interaction and quantum chromodynamics, their new results and their possible unification are analyzed. The author emphasizes the importance of knowledge as an inherent need of mankind. (D.Gy)

  11. Topics in field theory

    International Nuclear Information System (INIS)

    Velasco, E.S.

    1986-01-01

    This dissertation deals with several topics of field theory. Chapter I is a brief outline of the work presented in the next chapters. In chapter II, the Gauss-Bonnet-Chern theorem for manifolds with boundary is computed using the path integral representation of the Witten index for supersymmetric quantum mechanical systems. In chapter III the action of N = 2 (Poincare) supergravity is obtained in terms of N = 1 superfields. In chapter IV, N = 2 supergravity coupled to the (abelian) vector multiplet is projected into N - 1 superspace. There, the resulting set of constraints is solved in terms of unconstrained prepotential and the action in terms of N = 1 superfields is constructed. In chapter V the set of constraints for N = 2 conformal supergravity is projected into N = 1 superspace and solved in terms of N = 1 conformal supergravity fields a d matter prepotentials. In chapter VI the role of magnetic monopoles in the phase structure of the change one fixed length abelian Higgs model ins the latticer is investigated using analytic and numerical methods. The technique of monopole suppression is used to determine the phase transition lines that are monopole driven. Finally in chapter VII, the role of the charge of the Higgs field in the abelian Higgs model in the lattice is investigated

  12. Mapping the Field

    DEFF Research Database (Denmark)

    Goerres, Achim; Vanhuysse, Pieter

    2012-01-01

    Whereas the call for a political science based study of older people and ageing is not new (Cutler 1977; Heclo 1988), relatively little unified progress has been made so far. This chapter maps the field of generational politics and introduces our edited volume "Ageing Populations in Post-Industri......Whereas the call for a political science based study of older people and ageing is not new (Cutler 1977; Heclo 1988), relatively little unified progress has been made so far. This chapter maps the field of generational politics and introduces our edited volume "Ageing Populations in Post...... boxes by asking a number of central questions. How does population aging change political support for redistribution towards different age groups in society, including not just elderly people but also families with children? How, and when, do established parties in aging democracies implement policies......? The answers provided in this volume promise to be of major interest to scholars in fields such as political economy, political sociology, social policy, comparative politics, demography, and gerontology....

  13. Venus gravity fields

    Science.gov (United States)

    Sjogren, W. L.; Ananda, M.; Williams, B. G.; Birkeland, P. W.; Esposito, P. S.; Wimberly, R. N.; Ritke, S. J.

    1981-01-01

    Results of Pioneer Venus Orbiter observations concerning the gravity field of Venus are presented. The gravitational data was obtained from reductions of Doppler radio tracking data for the Orbiter, which is in a highly eccentric orbit with periapsis altitude varying from 145 to 180 km and nearly fixed periapsis latitude of 15 deg N. The global gravity field was obtained through the simultaneous estimation of the orbit state parameters and gravity coefficients from long-period variations in orbital element rates. The global field has been described with sixth degree and order spherical harmonic coefficients, which are capable of resolving the three major topographical features on Venus. Local anomalies have been mapped using line-of-sight accelerations derived from the Doppler residuals between 40 deg N and 10 deg S latitude at approximately 300 km spatial resolution. Gravitational data is observed to correspond to topographical data obtained by radar altimeter, with most of the gravitational anomalies about 20-30 milligals. Simulations evaluating the isostatic states of two topographic features indicate that at least partial isostasy prevails, with the possibility of complete compensation.

  14. Heavy fields and gravity

    Energy Technology Data Exchange (ETDEWEB)

    Goon, Garrett [Institute of Physics, Universiteit van Amsterdam,Science Park 904, Amsterdam, 1090 GL (Netherlands)

    2017-01-11

    We study the effects of heavy fields on 4D spacetimes with flat, de Sitter and anti-de Sitter asymptotics. At low energies, matter generates specific, calculable higher derivative corrections to the GR action which perturbatively alter the Schwarzschild-(A)dS family of solutions. The effects of massive scalars, Dirac spinors and gauge fields are each considered. The six-derivative operators they produce, such as ∼R{sup 3} terms, generate the leading corrections. The induced changes to horizon radii, Hawking temperatures and entropies are found. Modifications to the energy of large AdS black holes are derived by imposing the first law. An explicit demonstration of the replica trick is provided, as it is used to derive black hole and cosmological horizon entropies. Considering entropy bounds, it’s found that scalars and fermions increase the entropy one can store inside a region bounded by a sphere of fixed size, but vectors lead to a decrease, oddly. We also demonstrate, however, that many of the corrections fall below the resolving power of the effective field theory and are therefore untrustworthy. Defining properties of black holes, such as the horizon area and Hawking temperature, prove to be remarkably robust against higher derivative gravitational corrections.

  15. In-field analysis

    International Nuclear Information System (INIS)

    Stewart, Richard

    2010-01-01

    Full text: A new technology for in-field measurement of hydrocarbons in soil promises rapid results. Standard industry practice in Australia for measuring hydrocarbons in soil is to send a soil sample to an off-site accredited laboratory for analysis. This typically costs $25-50 per sample and takes 5-7 days to turnaround the results. While there are in-field hydrocarbon measurement technologies available in the US, most involve extracting the hydrocarbons from the soil and analysing the resulting liquid. These methods are time- consuming and often involve toxic solvents and clumsy equipment. A new technology developed by Ziltek and CSIRO allows for real-time me as-urement in the field. The user simply pulls the trigger on a hand-held infrared spectrometer and within a few seconds gets a digital read-out of the hydrocarbon concentration. The technology requires no toxic solvents or consumables, and sampling positions can also be logged automatically using GPS coordinates. A new technology developed by Ziltek and CSIRO allows for real-time measurement in the field. The user simply pulls the trigger on a hand-held infrared spectrometer and within a few seconds gets a digital read-out of the hydrocarbon concentration. The technology requires no toxic solvents or consumables, and sampling positions can also be logged automatically using GPS coordinates. The technology is essentially a software application that can be used with any third-party supplied hand-held infrared device. A working prototype has been tested at several contaminated sites across Australia, with very promising results. The site trials involved taking in-situ measurements using an infrared instrument before sending the soil to an external laboratory for conventional analysis - and comparing the results. Ziltek technical director Dr Ben Dearman noted at some sites the variation between the infrared results and lab results was less than 10 per cent.The technology gives a single concentration value in

  16. Introduction to gauge field theory

    International Nuclear Information System (INIS)

    Bailin, David; Love, Alexander

    1986-01-01

    The book is intended as an introduction to gauge field theory for the postgraduate student of theoretical particle physics. The topics discussed in the book include: path integrals, classical and quantum field theory, scattering amplitudes, feynman rules, renormalisation, gauge field theories, spontaneous symmetry breaking, grand unified theory, and field theories at finite temperature. (UK)

  17. Quantum fields in curved space

    International Nuclear Information System (INIS)

    Birrell, N.D.; Davies, P.C.W.

    1982-01-01

    The book presents a comprehensive review of the subject of gravitational effects in quantum field theory. Quantum field theory in Minkowski space, quantum field theory in curved spacetime, flat spacetime examples, curved spacetime examples, stress-tensor renormalization, applications of renormalization techniques, quantum black holes and interacting fields are all discussed in detail. (U.K.)

  18. Quality for quantum free fields

    International Nuclear Information System (INIS)

    Leyland, Pen; Roberts, John; Testard, Daniel; Centre National de la Recherche Scientifique, 13 - Marseille

    1978-07-01

    A proof is given concerning duality for the free neutral scalar boson field (abstract duality). Then real subspaces of a complex Hilbert space and the Von Neumann algebra associated with real subspaces are considered. Lastly duality for free fields (free electromagnetic field and free scalar field of any mass) is studied

  19. Stochastic quantization of Proca field

    International Nuclear Information System (INIS)

    Lim, S.C.

    1981-03-01

    We discuss the complications that arise in the application of Nelson's stochastic quantization scheme to classical Proca field. One consistent way to obtain spin-one massive stochastic field is given. It is found that the result of Guerra et al on the connection between ground state stochastic field and the corresponding Euclidean-Markov field extends to the spin-one case. (author)

  20. Covariant field equations in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Vanhecke, Bram [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium); Ghent University, Faculty of Physics, Gent (Belgium); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)

    2017-12-15

    Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Covariant field equations in supergravity

    International Nuclear Information System (INIS)

    Vanhecke, Bram; Proeyen, Antoine van

    2017-01-01

    Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Vector Fields on Product Manifolds

    OpenAIRE

    Kurz, Stefan

    2011-01-01

    This short report establishes some basic properties of smooth vector fields on product manifolds. The main results are: (i) On a product manifold there always exists a direct sum decomposition into horizontal and vertical vector fields. (ii) Horizontal and vertical vector fields are naturally isomorphic to smooth families of vector fields defined on the factors. Vector fields are regarded as derivations of the algebra of smooth functions.

  3. Unbalanced field RF electron gun

    Science.gov (United States)

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  4. Workplace photon radiation fields

    International Nuclear Information System (INIS)

    Burgess, P.H.; Bartlett, D.T.; Ambrosi, P.

    1999-01-01

    The knowledge of workplace radiation fields is essential for measures in radiation protection. Information about the energy and directional distribution of the incident photon radiation was obtained by several devices developed by the National Radiation Protection Board, United Kingdom, by the Statens Stralskyddsinstitut, Sweden, together with EURADOS and by the Physikalisch-Technische Bundesanstalt, Germany. The devices are described and some results obtained at workplaces in nuclear industry, medicine and science in the photon energy range from 20 keV to 7 MeV are given. (author)

  5. Near field communications handbook

    CERN Document Server

    Ahson, Syed A; Furht, Borko

    2011-01-01

    Near Field Communication, or NFC, is a short-range high frequency wireless communication technology that enables the exchange of data between devices over about a decimeter. The technology is a simple extension of the ISO 14443 proximity-card standard (contact less card, RFID) that combines the interface of a smart card and a reader into a single device with practical implications. A complete reference for NFC, this handbook provides technical information about all aspects of NFC, as well as applications. It covers basic concepts as well as research grade material and includes a discussion of

  6. Topics in field theory

    CERN Document Server

    Karpilovsky, G

    1989-01-01

    This monograph gives a systematic account of certain important topics pertaining to field theory, including the central ideas, basic results and fundamental methods.Avoiding excessive technical detail, the book is intended for the student who has completed the equivalent of a standard first-year graduate algebra course. Thus it is assumed that the reader is familiar with basic ring-theoretic and group-theoretic concepts. A chapter on algebraic preliminaries is included, as well as a fairly large bibliography of works which are either directly relevant to the text or offer supplementary material of interest.

  7. Geometrical description of fields

    International Nuclear Information System (INIS)

    Sokolik, H.

    1979-01-01

    The author suggests a purely algebraic interpretation of interaction. The main idea is to consider interaction as a deformation of an inhomogeneous algebra composed of momentum operators and an arbitrary group admitting the equation of the theory. The only difference between this approach and the conventional one is that the generalized momentum operators do not commute with aech other, due not merely to the introduction of some external interaction field, but to the change of the structure of the algebra from which the theory stems

  8. Holographic effective field theories

    Energy Technology Data Exchange (ETDEWEB)

    Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)

    2016-06-28

    We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

  9. High Field Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    A Workshop was held in Frascati at the end of September under the title 'Generation of High Fields for Particle Acceleration to Very High Energies'. It was organized by the CERN Accelerator School, the European Committee for Future Accelerators (ECFA) and the Italian INFN and was a further stage in the exploratory moves towards new techniques of acceleration. Such techniques might become necessary to respond to the needs of high energy physics some decades from now when the application of conventional techniques will probably have reached their limits.

  10. Beyond the field

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Lilleør, Helene Bie

    2014-01-01

    We estimate the impact of a Farmer Field School intervention among small-scale farmers in northern Tanzania on two main development objectives: food security and poverty. We employ a series of evaluation methodologies, including a Quasi-Difference-in-Difference setup, to account for potential...... selection into the project, despite lack of baseline data. We find strong positive effects on food security, but no effect on poverty. Investigating possible mechanisms for this result shows that reallocation of labor resources toward own agricultural production and improved production smoothing may have...

  11. Quantum fields and dissipation

    International Nuclear Information System (INIS)

    Henning, P.

    1996-06-01

    The description of thermal or non-equilibrium systems necessitates a quantum field theory which differs from the usual approach in two aspects: 1. The Hilbert space is doubled; 2. Stable quasi-particles do not exist in interacting systems. A mini-review of these two aspects is given from a practical viewpoint including two applications. For thermal states it is shown how infrared divergences occuring in perturbative quasi-particle theories are avoided, whereas for non-equilibrium states a memory effect is shown to arise in the thermalization. (orig.)

  12. Higgs Effective Field Theories

    CERN Document Server

    2016-01-01

    The main focus of this meeting is to present new theoretical advancements related to effective field theories, evaluate the impact of initial results from the LHC Run2, and discuss proposals for data interpretation/presentation during Run2. A crucial role of the meeting is to bring together theorists from different backgrounds and with different viewpoints and to extend bridges towards the experimental community. To this end, we would like to achieve a good balance between senior and junior speakers, enhancing the visibility of younger scientists while keeping some overview talks.

  13. The First Chandra Field

    Energy Technology Data Exchange (ETDEWEB)

    Weisskopf, Martin C.; /NASA, Marshall; Aldcroft, Thomas L.; /Harvard-Smithsonian Ctr. Astrophys.; Cameron, Robert A.; /Harvard-Smithsonian Ctr. Astrophys. /SLAC; Gandhi,; Foellmi, Cedric; /European Southern Obs., Chile; Elsner, Ronald F.; /NASA, Marshall; Patel, Sandeep K.; /USRA, Huntsville; Wu, Kinwah; /Mullard Space Sci. Lab.; O' Dell, Stephen; /NASA, Marshall

    2005-09-09

    Before the official first-light images, the Chandra X-ray Observatory obtained an X-ray image of the field to which its focal plane was first exposed. We describe this historic observation and report our study of the first Chandra field. Chandra's Advanced CCD Imaging Spectrometer (ACIS) detected 15 X-ray sources, the brightest being dubbed ''Leon X-1'' to honor the Chandra Telescope Scientist, Leon Van Speybroeck. Based upon our analysis of the X-ray data and spectroscopy at the European Southern Observatory (ESO; La Silla, Chile), we find that Leon X-1 is a Type-1 (unobscured) active galactic nucleus (AGN) at a redshift z = 0.3207. Leon X-1 exhibits strong Fe II emission and a broad-line Balmer decrement that is unusually flat for an AGN. Within the context of the Eigenvector-1 correlation space, these properties suggest that Leon X-1 may be a massive ({ge} 10{sup 9} M{sub {circle_dot}}) black hole, accreting at a rate approaching its Eddington limit.

  14. Measurement of radiofrequency fields

    International Nuclear Information System (INIS)

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs

  15. Gauge field theory

    International Nuclear Information System (INIS)

    Aref'eva, I.Ya.; Slavnov, A.A.

    1981-01-01

    This lecture is devoted to the discussion of gauge field theory permitting from the single point of view to describe all the interactions of elementary particles. The authors used electrodynamics and the Einstein theory of gravity to search for a renormgroup fixing a form of Lagrangian. It is shown that the gauge invariance added with the requirement of the minimum number of arbitraries in Lagrangian fixes unambigously the form of the electromagnetic interaction. The generalization of this construction for more complicate charge spaces results in the Yang-Mills theory. The interaction form in this theory is fixed with the relativity principle in the charge space. A quantum scheme of the Yang-Mills fields through the explicit separation of true dynamic variables is suggested. A comfortable relativistically invariant diagram technique for the calculation of a producing potential for the Green functions is described. The Ward generalized identities have been obtained and a procedure of the elimination of ultraviolet and infrared divergencies has been accomplished. Within the framework of QCD (quantum-chromodynamic) the phenomenon of the asymptotic freedom being the most successful prediction of the gauge theory of strong interactions was described. Working methods with QCD outside the framework of the perturbation theory have been described from a coupling constant. QCD is represented as a single theory possessing both the asymptotical freedom and the freedom retaining quarks [ru

  16. Coolside waste management research. Quarterly technical report, January 1--March 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The objective of this project is to produce sufficient information on the physical and chemical nature of Coolside wastes to design and construct physically stable and environmentally safe landfills. The report consists of three monthly progress reports which detail investigations of geotechnical properties and mineralogic reactions of Coolside fly ash, ash, and FGD sludges. Both laboratory and field lysimeters have been set up to gather leachates for testing. Results are presented on the laboratory leachates; field lysimeters have just begun to flow.

  17. Conformal invariant quantum field theory and composite field operators

    International Nuclear Information System (INIS)

    Kurak, V.

    1976-01-01

    The present status of conformal invariance in quantum field theory is reviewed from a non group theoretical point of view. Composite field operators dimensions are computed in some simple models and related to conformal symmetry

  18. UVIS Flat Field Uniformity

    Science.gov (United States)

    Quijano, Jessica Kim

    2009-07-01

    The stability and uniformity of the low-frequency flat fields {L-flat} of the UVIS detector will be assessed by using multiple-pointing observations of the globular clusters 47 Tucanae {NGC104} and Omega Centauri {NGC5139}, thus imaging moderately dense stellar fields. By placing the same star over different portions of the detector and measuring relative changes in its brightness, it will be possible to determine local variations in the response of the UVIS detector. Based on previous experience with STIS and ACS, it is deemed that a total of 9 different pointings will suffice to provide adequate characterization of the flat field stability in any given band. For each filter to be tested, the baseline consists of 9 pointings in a 3X3 box pattern with dither steps of about 25% of the FOV, or 40.5", in either the x or y direction {useful also for CTE measurements, if needed in the future}. During SMOV, the complement of filters to be tested is limited to the following 6 filters: F225W, F275W, F336W, for Omega Cen, and F438W, F606W, and F814W for 47 Tuc. Three long exposures for each target are arranged such that the initial dither position is observed with the appropriate filters for that target within one orbit at a single pointing, so that filter-to-filter differences in the observed star positions can be checked. In addition to the 9 baseline exposures, two sets of short exposures will be taken:a} one short exposure will be taken of OmegaCen with each of the visible filters {F438W, F606W and F814W} in order to check the geometric distortion solution to be obtained with the data from proposal 11444;b} for each target, a single short exposure will be taken with each filter to facilitate the study of the PSF as a function of position on the detector by providing unsaturated images of sparsely-spaced bright stars.This proposal corresponds to Activity Description ID WF39. It should execute only after the following proposal has executed:WF21 - 11434

  19. Electron-Cloud Wake Fields

    CERN Document Server

    Rumolo, Giovanni

    2002-01-01

    The electron cloud gives rise to coherent and incoherent single-bunch wake fields, both in the longitudinal and in the transverse direction, and to coherent coupled-bunch wakes. These wake fields can be computed using the simulation programs ECLOUD and HEADTAIL developed at CERN. We present the wake fields simulated for the LHC beam in the CERN SPS and at injection into the LHC in different magnetic field configurations (field-free region, dipole, and solenoid), where the magnetic field affects both the elec-tron motion during a bunch passage and the overall electron distribution in the beam pipe.

  20. The Emerging Strategic Entrepreneurship Field

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lyngsie, Jacob

    The field of strategic entrepreneurship is a fairly recent one. Its central idea is that opportunity-seeking and advantage-seeking — the former the central subject of the entrepreneurship field, the latter the central subject of the strategic management field — are processes that need...... to be considered jointly. The purpose of this brief chapter is to explain the emergence of SE theory field in terms of a response to research gaps in the neighboring fields of entrepreneurship and strategic management; describe the main tenets of SE theory; discuss its relations to neighboring fields; and finally...

  1. Magnetic fields in diffuse media

    CERN Document Server

    Pino, Elisabete; Melioli, Claudio

    2015-01-01

    This volume presents the current knowledge of magnetic fields in diffuse astrophysical media. Starting with an overview of 21st century instrumentation to observe astrophysical magnetic fields, the chapters cover observational techniques, origin of magnetic fields, magnetic turbulence, basic processes in magnetized fluids, the role of magnetic fields for cosmic rays, in the interstellar medium and for star formation. Written by a group of leading experts the book represents an excellent overview of the field. Nonspecialists will find sufficient background to enter the field and be able to appreciate the state of the art.

  2. Two field formulation of closed string field theory

    International Nuclear Information System (INIS)

    Bogojevic, A.R.

    1990-09-01

    A formulation of closed string field theory is presented that is based on a two field action. It represents a generalization of Witten's Chern-Simons formulation of 3d gravity. The action contains only 3 string interactions and no string field truncations, unlike the previous non-polynomial action of Zwiebach. The two field action is found to follow from a purely cubic, background independent action similar to the one for open strings. (orig.)

  3. Fractional Stochastic Field Theory

    Science.gov (United States)

    Honkonen, Juha

    2018-02-01

    Models describing evolution of physical, chemical, biological, social and financial processes are often formulated as differential equations with the understanding that they are large-scale equations for averages of quantities describing intrinsically random processes. Explicit account of randomness may lead to significant changes in the asymptotic behaviour (anomalous scaling) in such models especially in low spatial dimensions, which in many cases may be captured with the use of the renormalization group. Anomalous scaling and memory effects may also be introduced with the use of fractional derivatives and fractional noise. Construction of renormalized stochastic field theory with fractional derivatives and fractional noise in the underlying stochastic differential equations and master equations and the interplay between fluctuation-induced and built-in anomalous scaling behaviour is reviewed and discussed.

  4. Introduction to field theory

    CERN Multimedia

    CERN. Geneva; CERN. Geneva

    2001-01-01

    Starting from the notion of path integrals as developed by Feynman, we discuss field theory in zero spacetime dimensions. The concepts of perturbation expansions, connected amplitudes, Feynman diagrams, classical solutions, renormalization and the effective action are developed. The model is extended to four spacetime dimensions, and the full Feynman rules for relativisitc scalar theory derived. The S matrix and the concept of unitarity are discussed, leading to the amputation rules for S matrix elements from considerations of unitarity. The rules are extended to include particles with spin-1/2 and spin-1. The high-energy behaviour of the theory is discussed as a method to derive the gauge symmetry of the various models.

  5. High field electron linacs

    International Nuclear Information System (INIS)

    Le Duff, J.

    1985-12-01

    High field electron linacs are considered as potential candidates to provide very high energies beyond LEP. Since almost twenty years not much improvement has been made on linac technologies as they have been mostly kept at low and medium energies to be used as injectors for storage rings. Today, both their efficiency and their performances are being reconsidered, and for instance the pulse compression sheme developed at SLAC and introduced to upgrade the energy of that linac is a first step towards a new generation of linear accelerators. However this is not enough in terms of power consumption and more development is needed to improve both the efficiency of accelerating structures and the performances of RF power sources

  6. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  7. Fast harmonic field mapper

    International Nuclear Information System (INIS)

    Au, R.; Fowler, M.; Hanawa, H.; Riedel, J.; Qua, Z.G.

    1984-01-01

    In early 1983 it was decided to mount coils on arms separated by 120 degrees and buck them out so that the third harmonic dphi/dt component would be cancelled and thus the first and second field harmonics could be very accurately measured. The original intention was to do as others had done, namely, use fast ADC's to read the voltages, and computer process the result to get the Fourier components. However, because of the 100 to 1 dynamic range of the fast ADC's and the likelihood that noise would be a problem, the authors decided to do things differently. Using a fast Fourier transform analyzer was considered, but this instrument is very expensive, so they decided to use a completely electronic analog approach: The authors decided to use active bandpass filters to render the harmonic components

  8. Conflict field energy

    International Nuclear Information System (INIS)

    Krebsbach-Gnath, C.

    1981-01-01

    Violent social controversies characterize the treatment of the energy problem. Solutions of this conflict decisively depend on the knowledge and evaluation of the causes and the possible development. How is it possible to explain the opinions, views, and the attitude of the population to different kinds of energy. Which factors are decisive for the explosive effect and the stability of the conflict in the field of nulcear energy. What will happen when there arises a possible lack of energy. Which socio-political effects will such a lack have. Are there new proposals for solving problems in the nulcear-energy debate. The contributions of this book are results of scientific and empiric works. They provide perceptive approaches and analyses to the problems and by discussing them are useful in giving an orientation for political action. (orig.) [de

  9. Field theory of strings

    International Nuclear Information System (INIS)

    Ramond, P.

    1987-01-01

    We review the construction of the free equations of motion for open and closed strings in 26 dimensions, using the methods of the Florida Group. Differing from previous treatments, we argue that the constraint L 0 -anti L 0 =0 should not be imposed on all the fields of the closed string in the gauge invariant formalism; we show that it can be incorporated in the gauge invariant formalism at the price of being unable to extract the equations of motion from a Langrangian. We then describe our purely algebraic method to introduce interactions, which works equally well for open and closed strings. Quartic interactions are absent except in the Physical Gauge. Finally, we speculate on the role of the measure of the open string path functional. (orig.)

  10. Gauge field models

    International Nuclear Information System (INIS)

    Becchi, C.; Rouet, A.; Stora, R.

    1975-10-01

    Stora's analysis is continued in discussing the nonabelian (Yang-Mills) gauge field models (G.F.M.). The gauge independence of the physical scattering operator is discussed in some details and the connection between its unitary and the Slavnov symmetry outlined. Only the models involving semisimple gauge groups are considered. This greatly simplifies the analysis of the possible quantum corrections to the Quantum Action Principle which is reduced to the study of the cohomology group of the Lie algebra characterizing the gauge theory. The discussion is at the classical level for the algebraic properties of the SU(2) Higgs-Kibble-Englert-Brout-Faddeev-Popov lagrangian and its invariance under Slavnov identity transformations is exhibited. The renormalization of the Slavnov identity in the G.M.F. involving semisimple gauge groups is studied. The unitary and gauge independence of the physical S operator in the SU(2) H.K. model is dealt with [fr

  11. Strong field laser physics

    CERN Document Server

    2008-01-01

    Since the invention of the laser in the 1960s, people have strived to reach higher intensities and shorter pulse durations. High intensities and ultrashort pulse durations are intimately related. Recent developments have shown that high intensity lasers also open the way to realize pulses with the shortest durations to date, giving birth to the field of attosecond science (1 asec = 10-18s). This book is about high-intensity lasers and their applications. The goal is to give an up to date introduction to the technology behind these laser systems and to the broad range of intense laser applications. These applications include AMO (atomic molecular and optical) physics, x-ray science, attosecond science, plasma physics and particle acceleration, condensed matter science and laser micromachining, and finally even high-energy physics.

  12. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  13. A general field-covariant formulation of quantum field theory

    International Nuclear Information System (INIS)

    Anselmi, Damiano

    2013-01-01

    In all nontrivial cases renormalization, as it is usually formulated, is not a change of integration variables in the functional integral, plus parameter redefinitions, but a set of replacements, of actions and/or field variables and parameters. Because of this, we cannot write simple identities relating bare and renormalized generating functionals, or generating functionals before and after nonlinear changes of field variables. In this paper we investigate this issue and work out a general field-covariant approach to quantum field theory, which allows us to treat all perturbative changes of field variables, including the relation between bare and renormalized fields, as true changes of variables in the functional integral, under which the functionals Z and W=lnZ behave as scalars. We investigate the relation between composite fields and changes of field variables, and we show that, if J are the sources coupled to the elementary fields, all changes of field variables can be expressed as J-dependent redefinitions of the sources L coupled to the composite fields. We also work out the relation between the renormalization of variable-changes and the renormalization of composite fields. Using our transformation rules it is possible to derive the renormalization of a theory in a new variable frame from the renormalization in the old variable frame, without having to calculate it anew. We define several approaches, useful for different purposes, in particular a linear approach where all variable changes are described as linear source redefinitions. We include a number of explicit examples. (orig.)

  14. Chameleon field theories

    International Nuclear Information System (INIS)

    Khoury, Justin

    2013-01-01

    Chameleons are light scalar fields with remarkable properties. Through the interplay of self-interactions and coupling to matter, chameleon particles have a mass that depends on the ambient matter density. The manifestation of the fifth force mediated by chameleons therefore depends sensitively on their environment, which makes for a rich phenomenology. In this paper, we review two recent results on chameleon phenomenology. The first result a pair of no-go theorems limiting the cosmological impact of chameleons and their generalizations: (i) the range of the chameleon force at cosmological density today can be at most ∼Mpc; (ii) the conformal factor relating Einstein- and Jordan-frame scale factors is essentially constant over the last Hubble time. These theorems imply that chameleons have negligible effect on the linear growth of structure, and cannot account for the observed cosmic acceleration except as some form of dark energy. The second result pertains to the quantum stability of chameleon theories. We show how requiring that quantum corrections be small, so as to allow reliable predictions of fifth forces, leads to an upper bound of m −3 ) 1/3 eV for gravitational strength coupling, whereas fifth force experiments place a lower bound of m > 0.0042 eV. An improvement of less than a factor of 2 in the range of fifth force experiments could test all classical chameleon field theories whose quantum corrections are well-controlled and couple to matter with nearly gravitational strength regardless of the specific form of the chameleon potential. (paper)

  15. Field Audit Checklist Tool (FACT)

    Science.gov (United States)

    Download EPA's The Field Audit Checklist Tool (FACT). FACT is intended to help auditors perform field audits, to easily view monitoring plan, quality assurance and emissions data and provides access to data collected under MATS.

  16. Vacuum in intensive gauge fields

    International Nuclear Information System (INIS)

    Matinian, S.G.

    1977-12-01

    The behaviour of vacuum in a covariantly constant Yang-Mills field is considered. The expressions for the effective Lagrangian in an intensive field representing the asymptotic freedom of the theory are found

  17. Functional representations for quantized fields

    International Nuclear Information System (INIS)

    Jackiw, R.

    1988-01-01

    This paper provides information on Representing transformations in quantum theory bosonic quantum field theories: Schrodinger Picture; Represnting Transformations in Bosonic Quantum Field Theory; Two-Dimensional Conformal Transformations, Schrodinger picture representation, Fock space representation, Inequivalent Schrodinger picture representations; Discussion, Self-Dual and Other Models; Field Theory in de Sitter Space. Fermionic Quantum Field Theories: Schroedinger Picture; Schrodinger Picture Representation for Two-Dimensional; Conformal Transformations; Fock Space Dynamics in the Schrodinger Picture; Fock Space Evaluation of Anomalous Current and Conformal Commutators

  18. Geomagnetic Field During a Reversal

    Science.gov (United States)

    Heirtzler, J. R.

    2003-01-01

    It has frequently been suggested that only the geomagnetic dipole, rather than higher order poles, reverse during a geomagnetic field reversal. Under this assumption the geomagnetic field strength has been calculated for the surface of the Earth for various steps of the reversal process. Even without an eminent a reversal of the field, extrapolation of the present secular change (although problematic) shows that the field strength may become zero in some geographic areas within a few hundred years.

  19. TFTR magnetic field design analyses

    International Nuclear Information System (INIS)

    Davies, K.; Iwinski, E.; McWhirter, J.M.

    1975-11-01

    The three main magnetic field windings for the TFTR are the toroidal field (TF) windings, the ohmic heating (OH) winding, and the equilibrium field (EF) winding. The following information is provided for these windings: (1) descriptions, (2) functions, (3) magnetic designs, e.g., number and location of turns, (4) design methods, and (5) descriptions of resulting magnetic fields. This report does not deal with the thermal, mechanical support, or construction details of the windings

  20. Model of unified gauge fields

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1998-04-01

    In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author)

  1. Magnetic Field Topology in Jets

    Science.gov (United States)

    Gardiner, T. A.; Frank, A.

    2000-01-01

    We present results on the magnetic field topology in a pulsed radiative. jet. For initially helical magnetic fields and periodic velocity variations, we find that the magnetic field alternates along the, length of the jet from toroidally dominated in the knots to possibly poloidally dominated in the intervening regions.

  2. Quantization of fields with constraints

    Energy Technology Data Exchange (ETDEWEB)

    Gitman, D.M.; Tyutin, I.V.

    1990-01-01

    The quantization of singular field theories, in particular, gauge theories, is one of the key problems in quantum field theory. This book - which addresses the reader acquainted with the foundations of quantum field theory - provides a comprehensive analysis of this problem and techniques for its solution. The main topics are canonical and Lagrangian quantization and the path integral method. (orig.).

  3. High magnetic field MRI system

    International Nuclear Information System (INIS)

    Maeda, Hideaki; Urata, Masami; Satoh, Kozo

    1990-01-01

    A high field superconducting magnet, 4-5 T in central magnetic field, is required for magnetic resonance spectroscopic imaging (MRSI) on 31 P, essential nuclei for energy metabolism of human body. This paper reviews superconducting magnets for high field MRSI systems. Examples of the cross-sectional image and the spectrum of living animals are shown in the paper. (author)

  4. Field emission in RF cavities

    International Nuclear Information System (INIS)

    Bonin, B.

    1996-01-01

    Electron field emission limits the accelerating gradient in superconducting cavities. It is shown how and why it is an important problem. The phenomenology of field emission is then described, both in DC and RF regimes. Merits of a few plausible 'remedies' to field emission are discussed. (author)

  5. Estimation of Motion Vector Fields

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    1993-01-01

    This paper presents an approach to the estimation of 2-D motion vector fields from time varying image sequences. We use a piecewise smooth model based on coupled vector/binary Markov random fields. We find the maximum a posteriori solution by simulated annealing. The algorithm generate sample...... fields by means of stochastic relaxation implemented via the Gibbs sampler....

  6. Electric fields in the magnetosphere

    International Nuclear Information System (INIS)

    Falthammar, C.G.

    1989-01-01

    Electric field measurements on the satellites GEOS-1, GEOS-2, ISEE-1, and Viking have extended the empirical knowledge of electric fields in space so as to include the outer regions of the magnetosphere. While the measurements confirm some of the theoretically expected properties of the electric fields, they also reveal unexpected features and a high degree of complexity and variability. The existence of a magnetospheric dawn-to-dusk electric field, as expected on the basis of extrapolation from low altitude measurements, is confirmed in an average sense. However, the actual field exhibits large spatial and temporal variations, including strong fields of inductive origin. At the magnetopause, the average (dawn-to-dusk directed) tangential electric field component is typically obscured by irregular fluctuations of larger amplitude. The magnetic-field aligned component of the electric field, which is of particular importance for ionosphere-magnetosphere coupling and for auroral acceleration, is even now very difficult to measure directly. However, the data from electric field measurements provide further support for the conclusion, based on a variety of evidence, that a non-vanishing magnetic-field aligned electric field exists in the auroral acceleration region

  7. Characteristic of Rings. Prime Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-12-01

    Full Text Available The notion of the characteristic of rings and its basic properties are formalized [14], [39], [20]. Classification of prime fields in terms of isomorphisms with appropriate fields (ℚ or ℤ/p are presented. To facilitate reasonings within the field of rational numbers, values of numerators and denominators of basic operations over rationals are computed.

  8. Low field magnetic resonance imaging

    Science.gov (United States)

    Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

    2010-07-13

    A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

  9. Quantization of the Radiation Field

    Indian Academy of Sciences (India)

    field,quantization,Lamb shift. Avinash Khare ... actions as well as for theories beyond like grand unified theories. Further, the same ... cules as well as condensed matter physics, not to men- tion their ... of an electromagnetic field by a moving electron, and of the reaction of this field on the electron have not yet been touched.".

  10. Introduction to string field theory

    International Nuclear Information System (INIS)

    Horowitz, G.T.

    1989-01-01

    A light cone gauge superstring field theory is constructed. The BRST approach is described discussing generalizations to yield gauge invariant free superstring field theory and interacting theory for superstrings. The interaction term is explicitly expressed in terms of first quantized oscillators. A purily cubic action for superstring field theory is also derived. (author)

  11. Fields on a random lattice

    International Nuclear Information System (INIS)

    Itzykson, C.

    1983-10-01

    We review the formulation of field theory and statistical mechanics on a Poissonian random lattice. Topics discussed include random geometry, the construction of field equations for arbitrary spin, the free field spectrum and the question of localization illustrated in the one dimensional case

  12. Matching tomographic IMRT fields with static photon fields

    International Nuclear Information System (INIS)

    Sethi, A.; Leybovich, L.; Dogan, N.; Emami, B.

    2001-01-01

    The matching of abutting radiation fields presents a challenging problem in radiation therapy. Due to sharp penumbra of linear accelerator beams, small (1-2 mm) errors in field positioning can lead to large (>30%) hot or cold spots in the abutment region. With head and neck immobilization devices (thermoplastic mask/aquaplast) an average setup error of 3 mm has been reported. Therefore hot or cold spots approaching 50% of the prescription dose may occur along the matchline. Although abutting radiation fields have been investigated for static fields, there is no reported study regarding matching of tomographic IMRT and static fields. Compared to static fields, the matching of tomographic IMRT fields with static fields is more complicated. Since IMRT and static fields are planned on separate treatment planning computers, the dose in the abutment region is not specified. In addition, commonly used techniques for matching fields, such as feathering of junctions, are not practical. We have developed a method that substantially reduces dose inhomogeneity in the abutment region. In this method, a 'buffer zone' around the matchline was created and was included as part of the target for both IMRT and static field plans. In both fields, a small dose gradient (≤3%/mm) in the buffer zone was created. In the IMRT plan, the buffer zone was divided into three sections with dose varying from 83% to 25% of prescription dose. The static field dose profile was modified using either a specially designed physical (hard) or a dynamic (soft) wedge. When these modified fields were matched, the combined dose in the abutment region varied by ≤10% in the presence of setup errors spanning 4 mm (±2 mm) when the hard wedge was used and 10 mm (±5 mm) with the soft wedge

  13. Titan's Gravitational Field

    Science.gov (United States)

    Schubert, G.; Anderson, J. D.

    2013-12-01

    Titan's gravitational field is inferred from an analysis of archived radio Doppler data for six Cassini flybys. The analysis considers each flyby separately in contrast to the approach of lumping all the data together in a massive inversion. In this way it is possible to gain an improved understanding of the character of each flyby and its usefulness in constraining the gravitational coefficient C22 . Though our analysis is not yet complete and our final determination of C22 could differ from the result we report here by 1 or 2 sigma, we find a best-fit value of C22 equal to (13.21 × 0.17) × 10-6, significantly larger than the value of 10.0 × 10-6 obtained from an inversion of the lumped Cassini data. We also find no determination of the tidal Love number k2. The larger value of C22 implies a moment of inertia factor equal to 0.3819 × 0.0020 and a less differentiated Titan than is suggested by the smaller value. The larger value of C22 is consistent with an undifferentiated model of the satellite. While it is not possible to rule out either value of C22 , we prefer the larger value because its derivation results from a more hands on analysis of the data that extracts the weak hydrostatic signal while revealing the effects of gravity anomalies and unmodeled spacecraft accelerations on each of the six flybys.

  14. The North Field Development

    International Nuclear Information System (INIS)

    1993-01-01

    The Qatar Europe LNG Company's activities include gas production, gathering, treatment, liquefaction, shipping and marketing of Liquefied Natural Gas (LNG) and by-products. The (LNG) project to be developed by the Company shall be initially capable of processing 1200 mmscfd of raw gas and associated quantities of condensate from the North Field. Hydrocarbons produced will be delivered to shore in the industrial area (Ras Laffan) via a sub sea pipeline system. Raw gas is used as a feedstock into the liquefaction plant which is initially capable of producing 6.1 Million Tonnes Per Annum (MTPA) of (LNG). The initial quantity of (LNG) will be exported from (Ras Laffan) loading terminal to a receiving terminal located on the North East coast of Italy via a dedicated fleet of (LNG) carriers. The whole project (Upstream, Downstream and Shipping) shall be executed on an integrated scheme basis under the the direct control of the Qatar Europe LNG Company and in accordance with the overall Master Schedule in order to ensure a delivery of first shipment of (LNG) in the 2 nd half of 1997. 3 figs

  15. Superstring field theory

    International Nuclear Information System (INIS)

    Green, M.B.

    1984-01-01

    Superstring field theories are formulated in terms of light-cone-gauge superfields that are functionals of string coordinates chi(sigma) and theta(sigma). The formalism used preserves only the manifest SU(4) symmetry that corresponds to rotations among six of the eight transverse directions. In type I theories, which have one ten-dimensional supersymmetry and describe both open and closed strings, there are five interaction terms of two basic kinds. One kind is a breaking or joining interaction, which is a string generalization of a cubic Yang-Mills coupling. It is relevant to both the three open-string vertex and the open-string to closed-string transition vertex. The other kind is an exchange or crossing-over interaction, which is a string generalization of a cubic gravitational coupling. All the interactions can be uniquely determined by requiring continuity of the coordinates chi(sigma) and theta(sigma) (which implies local conservation of the conjugate momenta) and by imposing the global supersymmetry algebra. Specific local operators are identified for each of the two kinds of interactions. In type II theories, which have two ten-dimensional supersymmetries and contain closed strings only, the entire interaction hamiltonian consists of a single cubic vertex. The higher-order contact terms of the N=8 supergravity theory that arises in the low-energy limit give an effective description of the exchange of massive string modes. (orig.)

  16. Digestible quantum field theory

    CERN Document Server

    Smilga, Andrei

    2017-01-01

    This book gives an intermediate level treatment of quantum field theory, appropriate to a reader with a first degree in physics and a working knowledge of special relativity and quantum mechanics. It aims to give the reader some understanding of what QFT is all about, without delving deep into actual calculations of Feynman diagrams or similar. The author serves up a seven‐course menu, which begins with a brief introductory Aperitif. This is followed by the Hors d'oeuvres, which set the scene with a broad survey of the Universe, its theoretical description, and how the ideas of QFT developed during the last century. In the next course, the Art of Cooking, the author recaps on some basic facts of analytical mechanics, relativity, quantum mechanics and also presents some nutritious “extras” in mathematics (group theory at the elementary level) and in physics (theory of scattering). After these preparations, the reader should have a good appetite for the Entrées ‐ the central par t of the book where the...

  17. Logarithmic conformal field theory

    Science.gov (United States)

    Gainutdinov, Azat; Ridout, David; Runkel, Ingo

    2013-12-01

    Conformal field theory (CFT) has proven to be one of the richest and deepest subjects of modern theoretical and mathematical physics research, especially as regards statistical mechanics and string theory. It has also stimulated an enormous amount of activity in mathematics, shaping and building bridges between seemingly disparate fields through the study of vertex operator algebras, a (partial) axiomatisation of a chiral CFT. One can add to this that the successes of CFT, particularly when applied to statistical lattice models, have also served as an inspiration for mathematicians to develop entirely new fields: the Schramm-Loewner evolution and Smirnov's discrete complex analysis being notable examples. When the energy operator fails to be diagonalisable on the quantum state space, the CFT is said to be logarithmic. Consequently, a logarithmic CFT is one whose quantum space of states is constructed from a collection of representations which includes reducible but indecomposable ones. This qualifier arises because of the consequence that certain correlation functions will possess logarithmic singularities, something that contrasts with the familiar case of power law singularities. While such logarithmic singularities and reducible representations were noted by Rozansky and Saleur in their study of the U (1|1) Wess-Zumino-Witten model in 1992, the link between the non-diagonalisability of the energy operator and logarithmic singularities in correlators is usually ascribed to Gurarie's 1993 article (his paper also contains the first usage of the term 'logarithmic conformal field theory'). The class of CFTs that were under control at this time was quite small. In particular, an enormous amount of work from the statistical mechanics and string theory communities had produced a fairly detailed understanding of the (so-called) rational CFTs. However, physicists from both camps were well aware that applications from many diverse fields required significantly more

  18. Rydberg atoms in strong fields

    International Nuclear Information System (INIS)

    Kleppner, D.; Tsimmerman, M.

    1985-01-01

    Experimental and theoretical achievements in studying Rydberg atoms in external fields are considered. Only static (or quasistatic) fields and ''one-electron'' atoms, i.e. atoms that are well described by one-electron states, are discussed. Mainly behaviour of alkali metal atoms in electric field is considered. The state of theoretical investigations for hydrogen atom in magnetic field is described, but experimental data for atoms of alkali metals are presented as an illustration. Results of the latest experimental and theoretical investigations into the structure of Rydberg atoms in strong fields are presented

  19. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  20. Urban Fields in the making

    DEFF Research Database (Denmark)

    Hovgesen, Henrik Harder; Nielsen, Thomas Alexander Sick

    cities and accentuates the concept of the ?urban field? suggested by John Friedmann (1978). The concept of ?urban field? suggest that mobility has been democratizised and increased to a level where several cities can be part of the same functionally integrated urban field. As a consequence...... the significance of the single urban centre and the city as an entity will change markedly. This paper aims to analyse the development towards urban travel- and commuter fields in Denmark. The question asked is to what degree urban fields are emerging? ? And what is the speed of this development....

  1. Studies in quantum field theory

    International Nuclear Information System (INIS)

    Bender, C.M.; Mandula, J.E.; Shrauner, J.E.

    1982-01-01

    Washington University is currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large orders; quark condensation in QCD; chiral symmetry breaking; the l/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD

  2. Topics in quantum field theory

    International Nuclear Information System (INIS)

    Svaiter, N.F.

    2006-11-01

    This paper presents some important aspects on quantum field theory, covering the following aspects: the triumph and limitations of the quantum field theory; the field theory in curved spaces - Hawking and Unruh-Davies effects; the problem of divergent theory of the zero-point; the problem of the spinning detector and the Trocheries-Takeno vacuum; the field theory at finite temperature - symmetry breaking and phase transition; the problem of the summability of the perturbative series and the perturbative expansion for the strong coupling; quantized fields in presence of classical macroscopic structures; the Parisi-Wu stochastic quantization method

  3. Field reversal in mirror machines

    International Nuclear Information System (INIS)

    Pearlstein, L.D.; Anderson, D.V.; Boozer, A.H.

    1978-01-01

    This report discusses some of the physics issues anticipated in field-reversed mirrors. The effect of current cancellation due to electrons is described. An estimate is made of the required impurity level to maintain a field-reversed configuration. The SUPERLAYER code is used to simulate the high-β 2XIIB results, and favorable comparisons require inclusion of quasilinear RF turbulence. Impact of a quadrupole field on field-line closure and resonant transport is discussed. A simple self-consistent model of ion currents is presented. Conditions for stability of field-reversed configurations to E x B driven rotations are determined

  4. Field Model: An Object-Oriented Data Model for Fields

    Science.gov (United States)

    Moran, Patrick J.

    2001-01-01

    We present an extensible, object-oriented data model designed for field data entitled Field Model (FM). FM objects can represent a wide variety of fields, including fields of arbitrary dimension and node type. FM can also handle time-series data. FM achieves generality through carefully selected topological primitives and through an implementation that leverages the potential of templated C++. FM supports fields where the nodes values are paired with any cell type. Thus FM can represent data where the field nodes are paired with the vertices ("vertex-centered" data), fields where the nodes are paired with the D-dimensional cells in R(sup D) (often called "cell-centered" data), as well as fields where nodes are paired with edges or other cell types. FM is designed to effectively handle very large data sets; in particular FM employs a demand-driven evaluation strategy that works especially well with large field data. Finally, the interfaces developed for FM have the potential to effectively abstract field data based on adaptive meshes. We present initial results with a triangular adaptive grid in R(sup 2) and discuss how the same design abstractions would work equally well with other adaptive-grid variations, including meshes in R(sup 3).

  5. Neural fields theory and applications

    CERN Document Server

    Graben, Peter; Potthast, Roland; Wright, James

    2014-01-01

    With this book, the editors present the first comprehensive collection in neural field studies, authored by leading scientists in the field - among them are two of the founding-fathers of neural field theory. Up to now, research results in the field have been disseminated across a number of distinct journals from mathematics, computational neuroscience, biophysics, cognitive science and others. Starting with a tutorial for novices in neural field studies, the book comprises chapters on emergent patterns, their phase transitions and evolution, on stochastic approaches, cortical development, cognition, robotics and computation, large-scale numerical simulations, the coupling of neural fields to the electroencephalogram and phase transitions in anesthesia. The intended readership are students and scientists in applied mathematics, theoretical physics, theoretical biology, and computational neuroscience. Neural field theory and its applications have a long-standing tradition in the mathematical and computational ...

  6. Error field considerations for BPX

    International Nuclear Information System (INIS)

    LaHaye, R.J.

    1992-01-01

    Irregularities in the position of poloidal and/or toroidal field coils in tokamaks produce resonant toroidal asymmetries in the vacuum magnetic fields. Otherwise stable tokamak discharges become non-linearly unstable to disruptive locked modes when subjected to low level error fields. Because of the field errors, magnetic islands are produced which would not otherwise occur in tearing mode table configurations; a concomitant reduction of the total confinement can result. Poloidal and toroidal asymmetries arise in the heat flux to the divertor target. In this paper, the field errors from perturbed BPX coils are used in a field line tracing code of the BPX equilibrium to study these deleterious effects. Limits on coil irregularities for device design and fabrication are computed along with possible correcting coils for reducing such field errors

  7. Chameleons with Field Dependent Couplings

    CERN Document Server

    Brax, Philippe; Mota, David F; Nunes, Nelson J; Winther, Hans A

    2010-01-01

    Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power run-away potentials and field independent couplings to matter. In this paper we investigate field-theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for E\\"ot-Wash experiments, fifth-force searches and Casimir force experiments. Requiring that the scalar-field evades gravitational tests, we find that the coupling is sensitive to a mass-scale which is of order of the Hubble scale today.

  8. Hyperbolic-symmetry vector fields.

    Science.gov (United States)

    Gao, Xu-Zhen; Pan, Yue; Cai, Meng-Qiang; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2015-12-14

    We present and construct a new kind of orthogonal coordinate system, hyperbolic coordinate system. We present and design a new kind of local linearly polarized vector fields, which is defined as the hyperbolic-symmetry vector fields because the points with the same polarization form a series of hyperbolae. We experimentally demonstrate the generation of such a kind of hyperbolic-symmetry vector optical fields. In particular, we also study the modified hyperbolic-symmetry vector optical fields with the twofold and fourfold symmetric states of polarization when introducing the mirror symmetry. The tight focusing behaviors of these vector fields are also investigated. In addition, we also fabricate micro-structures on the K9 glass surfaces by several tightly focused (modified) hyperbolic-symmetry vector fields patterns, which demonstrate that the simulated tightly focused fields are in good agreement with the fabricated micro-structures.

  9. ATLAS cavern magnetic field calculations

    International Nuclear Information System (INIS)

    Vorojtsov, S.B.; Vorozhtsov, A.S.; Butin, F.; Price, M.

    2000-01-01

    A new approach has been adopted in an attempt to produce a complete ATLAS cavern B-field map using a more precise methodological approach (variable magnetisation, depending on the external field) and the latest design taking into account of the structural elements. The basic idea was to produce a dedicated basic TOSCA model and then to insert a series of ferromagnetic structure elements to monitor the perturbative effect on the basic field map. Eventually, it was found: the bedplate field perturbation is an order of magnitude above the permissible level; manufacturing of the bedplates from nonmagnetic material or careful evaluation of their field contribution in the event reconstruction codes is required; the field value at the rack positions is higher than the permissible one; the final position of racks should be chosen taking into account the detailed magnetic field distribution

  10. The logarithmic conformal field theories

    International Nuclear Information System (INIS)

    Rahimi Tabar, M.R.; Aghamohammadi, A.; Khorrami, M.

    1997-01-01

    We study the correlation functions of logarithmic conformal field theories. First, assuming conformal invariance, we explicitly calculate two- and three-point functions. This calculation is done for the general case of more than one logarithmic field in a block, and more than one set of logarithmic fields. Then we show that one can regard the logarithmic field as a formal derivative of the ordinary field with respect to its conformal weight. This enables one to calculate any n-point function containing the logarithmic field in terms of ordinary n-point functions. Finally, we calculate the operator product expansion (OPE) coefficients of a logarithmic conformal field theory, and show that these can be obtained from the corresponding coefficients of ordinary conformal theory by a simple derivation. (orig.)

  11. The Swarm Initial Field Model for the 2014 Geomagnetic Field

    Science.gov (United States)

    Olsen, Nils; Hulot, Gauthier; Lesur, Vincent; Finlay, Christopher C.; Beggan, Ciaran; Chulliat, Arnaud; Sabaka, Terence J.; Floberghagen, Rune; Friis-Christensen, Eigil; Haagmans, Roger

    2015-01-01

    Data from the first year of ESA's Swarm constellation mission are used to derive the Swarm Initial Field Model (SIFM), a new model of the Earth's magnetic field and its time variation. In addition to the conventional magnetic field observations provided by each of the three Swarm satellites, explicit advantage is taken of the constellation aspect by including east-west magnetic intensity gradient information from the lower satellite pair. Along-track differences in magnetic intensity provide further information concerning the north-south gradient. The SIFM static field shows excellent agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for east-west intensity differences between the lower satellite pair being only 0.12 nT.

  12. Field Science--the Nature and Utility of Scientific Fields.

    Science.gov (United States)

    Casadevall, Arturo; Fang, Ferric C

    2015-09-08

    Fields are the fundamental sociological units of science. Despite their importance, relatively little has been written about their emergence, composition, structure, and function in the scientific enterprise. This essay considers the nature of fields and their important role in maintaining information and providing normative standards for scientific work. We suggest that fields arise naturally as a consequence of increasing information and scientific specialization. New fields tend to emerge as research communities grow, which may reflect biologically determined optima for the size of human groups. The benefits of fields include the organization of scientists with similar interests into communities that collectively define the next important problems to pursue. In the discipline of microbiology, fields are often organized on the basis of phylogenetic differences between microorganisms being studied. Although fields are essential to the proper functioning of science, their emergence can restrict access by outsiders and sustain dogmas that hinder progress. We suggest mechanisms to improve the functioning of scientific fields and to promote interdisciplinary interaction between fields. Copyright © 2015 Casadevall and Fang.

  13. The gravity field and GGOS

    DEFF Research Database (Denmark)

    Forsberg, René; Sideris, M.G.; Shum, C.K.

    2005-01-01

    The gravity field of the earth is a natural element of the Global Geodetic Observing System (GGOS). Gravity field quantities are like spatial geodetic observations of potential very high accuracy, with measurements, currently at part-per-billion (ppb) accuracy, but gravity field quantities are also...... unique as they can be globally represented by harmonic functions (long-wavelength geopotential model primarily from satellite gravity field missions), or based on point sampling (airborne and in situ absolute and superconducting gravimetry). From a GGOS global perspective, one of the main challenges...... is to ensure the consistency of the global and regional geopotential and geoid models, and the temporal changes of the gravity field at large spatial scales. The International Gravity Field Service, an umbrella "level-2" IAG service (incorporating the International Gravity Bureau, International Geoid Service...

  14. Introduction to gauge field theory

    International Nuclear Information System (INIS)

    Bailin, D.; Love, A.

    1986-01-01

    This book provides a postgraduate level introduction to gauge field theory entirely from a path integral standpoint without any reliance on the more traditional method of canonical quantisation. The ideas are developed by quantising the self-interacting scalar field theory, and are then used to deal with all the gauge field theories relevant to particle physics, quantum electrodynamics, quantum chromodynamics, electroweak theory, grand unified theories, and field theories at non-zero temperature. The use of these theories to make precise experimental predictions requires the development of the renormalised theories. This book provides a knowledge of relativistic quantum mechanics, but not of quantum field theory. The topics covered form a foundation for a knowledge of modern relativistic quantum field theory, providing a comprehensive coverage with emphasis on the details of actual calculations rather than the phenomenology of the applications

  15. Gauge invariant fractional electromagnetic fields

    International Nuclear Information System (INIS)

    Lazo, Matheus Jatkoske

    2011-01-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  16. Gauge invariant fractional electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lazo, Matheus Jatkoske, E-mail: matheuslazo@furg.br [Instituto de Matematica, Estatistica e Fisica - FURG, Rio Grande, RS (Brazil)

    2011-09-26

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  17. Acoustic field modulation in regenerators

    Science.gov (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

    2016-12-01

    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  18. Local fields and their extensions

    CERN Document Server

    Fesenko, I B

    2002-01-01

    This book offers a modern presentation of local fields whose spectacular development was initiated almost one hundred years ago by K. Hensel. The volume consists of nine chapters divided into four parts: arithmetic properties of local fields, class field theory for various types of local fields and generalizations, explicit formulas for the Hilbert pairing, and Milnor K-groups of fields and of local fields. The first three parts essentially simplify, revise, and update the first edition. This second edition contains about sixty additional pages reflecting several aspects of the developments in local number theory in the last ten years. Exercises point to many other paths for exploration. The book is designed for graduate students and research mathematicians interested in local number theory and its applications in arithmetic algebraic geometry.

  19. Partially massless fields during inflation

    Science.gov (United States)

    Baumann, Daniel; Goon, Garrett; Lee, Hayden; Pimentel, Guilherme L.

    2018-04-01

    The representation theory of de Sitter space allows for a category of partially massless particles which have no flat space analog, but could have existed during inflation. We study the couplings of these exotic particles to inflationary perturbations and determine the resulting signatures in cosmological correlators. When inflationary perturbations interact through the exchange of these fields, their correlation functions inherit scalings that cannot be mimicked by extra massive fields. We discuss in detail the squeezed limit of the tensor-scalar-scalar bispectrum, and show that certain partially massless fields can violate the tensor consistency relation of single-field inflation. We also consider the collapsed limit of the scalar trispectrum, and find that the exchange of partially massless fields enhances its magnitude, while giving no contribution to the scalar bispectrum. These characteristic signatures provide clean detection channels for partially massless fields during inflation.

  20. Computers in field ion microscopy

    International Nuclear Information System (INIS)

    Suvorov, A.L.; Razinkova, T.L.; Sokolov, A.G.

    1980-01-01

    A review is presented of computer applications in field ion microscopy (FIM). The following topics are discussed in detail: (1) modeling field ion images in perfect crystals, (2) a general scheme of modeling, (3) modeling of the process of field evaporation, (4) crystal structure defects, (5) alloys, and (6) automation of FIM experiments and computer-assisted processing of real images. 146 references are given