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.)

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...

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

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.

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.

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.

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

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%.

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

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

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.

Measurement of precipitation using lysimeters

Science.gov (United States)

Fank, Johann; Klammler, Gernot

2013-04-01

wind speeds and the measured outliers of lysimeter mass. Moreover, the influence of wind seems to be varying for different lysimeters. At the agricultural test site Wagna, Austria, two precipitation gauges in high temporal resolution (weighing-recording gauge and tipping-bucket gauge; both 200 cm² surface; measuring height 1.5 m) are installed. Furthermore, mass time series of various lysimeters cultivated with different vegetation is also available for the same location. Appropriate methods to compensate the influence of wind on measuring precipitation using lysimeters are investigated and results between the different measuring devices are compared. Results show that precipitation measured with lysimeters is generally higher, especially compared to the weighing-recording gauge. In addition it is detected that also the data interval of lysimeter mass time series used for quantifying precipitation (e.g., 1 day, 1 hour, 30 minutes, 10 minutes) is a crucial factor and influences the result. Summarizing, the potential of using highly precise weighable lysimeters for measuring precipitation at the point scale is rather high. However, methods used to compensate external effects on lysimeter weighing have to be enhanced for a global application of using lysimeters as precipitation gauges. Meissner, R., J. Seeger, H. Rupp, M. Seyfarth & H. Borg, 2007: Measurement of dew, fog, and rime with a high-precision gravitation Lysimeter. J. Plant Nutr. Soil Sci. 2007, 170, p. 335-344. WMO (World Meteorological Organization), 2008. Guide to Meteorological Instruments and Methods of Observation. WMO-No. 8, 140 pp.

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

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

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.)

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

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

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...

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

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

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

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.

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

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

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.

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.

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

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

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

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

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.)

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

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)

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

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

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

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

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.

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

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

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

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

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

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.

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

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.

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)

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

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.

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

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.

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.

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

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.

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.)

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.)

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.

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

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.

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

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.

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

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

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.)

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

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 K_sp) 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

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

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.

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

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.)

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.

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

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.

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.

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....

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

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

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

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.

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

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.

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.

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

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

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.

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

Model Uncertainty and Validation was one of the four themes of BIOMOVS II which had been identified by the programme's steering committee. It arose out of a concern that biosphere assessment models are generally simplified representations of highly complex environmental systems which, therefore, include a degree of uncertainty in their outputs. This uncertainty may be due to inadequate representations of the physical, chemical and biological processes; issues associated with scaling up highly non-linear systems; problems of model identification, in particular user interpretation. Therefore, during the course of the 5 year (1991-1996) BIOMOVS II programme a number of working sub-groups reestablished to address these issues. This document is the final report of the Prediction of Upward Migration of Radionuclides in Lysimeters sub-group which was established towards the end of the programme, late in 1994. It describes the 'blind' application of various hydrological and radiochemical transport models to experiment data derived from vegetated lysimeters. In order to investigate soil-to-plant transfer processes affecting the radionuclide migration from contaminated near surface water tables into arable crops, a lysimeter experiment has been undertaken at Imperial College, funded by UK Nirex Ltd. Detailed observations of climate, soil hydrology, plant growth and radiochemical migration were collected on the uptake of various radionuclides by a winter wheat crop. A selected set of data was made available to members of BIOMOVS II in order to allow them to test relevant components of current versions of assessment code. This was a challenging task owing to the rather unusual experimental design, in particular, the introduction of radionuclides at the base of the lysimeter, 5 cm below a fixed water table, and their subsequent upward migration through the soil. The comprehensive hydrological data set available provided various modelers, particularly those

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

Model Uncertainty and Validation was one of the four themes of BIOMOVS II which had been identified by the programme's steering committee. It arose out of a concern that biosphere assessment models are generally simplified representations of highly complex environmental systems which, therefore, include a degree of uncertainty in their outputs. This uncertainty may be due to inadequate representations of the physical, chemical and biological processes; issues associated with scaling up highly non-linear systems; problems of model identification, in particular user interpretation. Therefore, during the course of the 5 year (1991-1996) BIOMOVS II programme a number of working sub-groups reestablished to address these issues. This document is the final report of the Prediction of Upward Migration of Radionuclides in Lysimeters sub-group which was established towards the end of the programme, late in 1994. It describes the 'blind' application of various hydrological and radiochemical transport models to experiment data derived from vegetated lysimeters. In order to investigate soil-to-plant transfer processes affecting the radionuclide migration from contaminated near surface water tables into arable crops, a lysimeter experiment has been undertaken at Imperial College, funded by UK Nirex Ltd. Detailed observations of climate, soil hydrology, plant growth and radiochemical migration were collected on the uptake of various radionuclides by a winter wheat crop. A selected set of data was made available to members of BIOMOVS II in order to allow them to test relevant components of current versions of assessment code. This was a challenging task owing to the rather unusual experimental design, in particular, the introduction of radionuclides at the base of the lysimeter, 5 cm below a fixed water table, and their subsequent upward migration through the soil. The comprehensive hydrological data set available provided various modelers, particularly those involved in tritium

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)

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.

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

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.

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.

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.)

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.)

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

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

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

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

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.

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

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)

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.

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.

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.

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

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.

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.

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

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.

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.

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

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 ...

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.

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)

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)

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)

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.

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

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.

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

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.

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

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 ...

Treatment of log yard run-off by irrigation of grass and willows

International Nuclear Information System (INIS)

Jonsson, Maria; Dimitriou, Ioannis; Aronsson, Paer; Elowson, Torbjoern

2006-01-01

Log yard run-off is a potential environmental risk, among other things because it creates an oxygen deficiency in receiving watercourses. This study was conducted to investigate the purification efficiency of soil-plant systems with couchgrass (Elymus repens) and willows (Salix sp.) when intensively irrigated with run-off from an open sprinkling system at a Norway spruce (Picea abies) log yard. The purification efficiency was determined both at the field scale (couchgrass) and in 68-L lysimeters (couchgrass and willows). Groundwater in the field and drainage water from the lysimeters were analysed for Total Organic Carbon (TOC), distillable phenols, total P, and total N. Retention of TOC, phenols and P occurred but no difference between couchgrass and willows was observed. The system had better purification capacity at the field scale than in the lysimeters. -- By irrigating willow and couchgrass soil-plant systems with log yard run-off water, TOC, phenols, and phosphorus were reduced with 35% to 96% in the water

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.

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

Subsurface Investigations Program at the radioactive waste management complex of the Idaho National Engineering Laboratory. Annual progress report, FY-1985

International Nuclear Information System (INIS)

Hubbell, J.M.; Hull, L.C.; Humphrey, T.G.; Russell, B.F.; Pittman, J.R.; Cannon, K.M.

1985-12-01

This report describes work conducted in FY-85 in support of the Subsurface Investigation Program at the Radioactive Waste Management Complex of the Idaho National Engineering Laboratory. The work is part of a continuing effort to define and predict radionuclide migration from buried waste. The Subsurface Investigation Program is a cooperative study conducted by EG and G Idaho and the US Geological Survey, INEL Office. EG and G is responsible for the shallow drilling, solution chemistry, and net downward flux portions of this program, while the US Geological Survey is responsible for the weighing lysimeters and test trench. Data collection was initiated by drilling, sampling, and instrumenting shallow wells, continuing the installation of test trenches, and modifying the two weighing lysimeters. Twenty-one shallow auger holes were around the Radioactive Waste Management Complex (RWMC) to evaluate radionuclide content in the surficial sediments, to determine the geologic and hydrologic characteristics of the surficial sediments, and to provide as monitoring sites for moisture in these sediments. Eighteen porous cup lysimeters were installed in 12 auger holes to collect soil water samples from the surficial sediments. Fourteen auger holes were instrumented with tensiometers, gypsum blocks and/or psychrometers at various depths throughout the RWMC. Readings from these instruments are taken on a monthly basis

Limited transport of functionalized multi-walled carbon nanotubes in two natural soils

International Nuclear Information System (INIS)

Kasel, Daniela; Bradford, Scott A.; Šimůnek, Jiří; Pütz, Thomas; Vereecken, Harry; Klumpp, Erwin

2013-01-01

Column experiments were conducted in undisturbed and in repacked soil columns at water contents close to saturation (85–96%) to investigate the transport and retention of functionalized 14 C-labeled multi-walled carbon nanotubes (MWCNT) in two natural soils. Additionally, a field lysimeter experiment was performed to provide long-term information at a larger scale. In all experiments, no breakthrough of MWCNTs was detectable and more than 85% of the applied radioactivity was recovered in the soil profiles. The retention profiles exhibited a hyper-exponential shape with greater retention near the column or lysimeter inlet and were successfully simulated using a numerical model that accounted for depth-dependent retention. In conclusion, results indicated that the soils acted as a strong sink for MWCNTs. Little transport of MWCNTs is therefore likely to occur in the vadose zone, and this implies limited potential for groundwater contamination in the investigated soils. -- Highlights: •Investigation of undisturbed soil columns and lysimeter. •Transport experiments under water-unsaturated conditions. •Retention profiles were measured and numerically modeled. •Complete retention of MWCNT in undisturbed and repacked soil columns. -- In undisturbed columns and a lysimeter study, complete retention of functionalized multi-walled carbon nanotubes was found in two soils at environmentally relevant conditions

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.

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)

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

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

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.

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)

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)

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.

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

Fertilizer source effects on phosphate and nitrate leaching through simulated golf greens

International Nuclear Information System (INIS)

Shuman, L.M.

2003-01-01

In general, more P than N leached from both field and greenhouse lysimeters. - Phosphorus and nitrogen leached from high-porosity golf greens can adversely affect surface water and groundwater quality. Greenhouse and field lysimeter experiments were carried out to determine the effects of eight fertilizer sources on P and N leaching from simulated golf greens. Phosphorus appeared in the leachate later than nitrate-N, and the highest concentrations were for the soluble 20-20-20 and the 16-25-12 starter fertilizers. The other six sources resulted in lower P concentrations. The soluble 20-20-20 and the 16-25-12 sources each resulted in 43% of the added P eluting in the leachate, whereas the others varied from 15 to 25%. For nitrate-N the lowest cumulative mass was for the controlled-release 13-13-13 and sulfur-coated urea. A higher percentage of applied P than applied N leached from both field and greenhouse lysimeters. However, the amounts of P leached for the field lysimeters were lower than for the greenhouse columns

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

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...

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.

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.

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.

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

An electrical resistivity-based method for investigation of subsurface structure

Science.gov (United States)

Alves Meira Neto, A.; Litwin, D.; Troch, P. A. A.; Ferre, T. P. A.

2017-12-01

Resolving the spatial distribution of soil porosity within the subsurface is of great importance for understanding flow and transport within heterogeneous media. Additionally, porosity patterns can be associated with the availability of water and carbon dioxide that will drive geochemical reactions and constrain microbiological growth. The use of controlled experimentation has the potential to circumvent problems related to the external and internal variability of natural systems, while also allowing a higher degree of observability. In this study, we suggest an ERT-based method of retrieving porosity fields based on the application of Archie's law associated with an experimental procedure that can be used in laboratory-scale studies. We used a 2 cubic meter soil lysimeter, equipped with 238 electrodes distributed along its walls for testing the method. The lysimeter serves as a scaled-down version of the highly monitored artificial hillslopes at the Landscape Evolution Observatory (LEO) located at Biosphere 2 - University of Arizona. The capability of the ERT system in deriving spatially distributed patterns of porosity with respect to its several sources of uncertainty was numerically evaluated. The results will be used to produce an optimal experimental design and for assessing the reliability of experimental results. This novel approach has the potential to further resolve subsurface heterogeneity within the LEO project, and highlight the use of ERT-derived results for hydro-bio-geochemical studies.

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.)

The Juno Magnetic Field Investigation

Science.gov (United States)

Connerney, J. E. P.; Benn, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.; Murphy, S.; Odom, J.; Oliversen, R.; Schnurr, R.; Sheppard, D.; Smith, E. J.

2017-11-01

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 suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to ˜20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 × 106 nT per axis) with a resolution of ˜0.05 nT in the most sensitive dynamic range (±1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through the imager field of

Field investigation to assess nutrient emission from paddy field to surface water in river catchment

Science.gov (United States)

Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

2015-04-01

In order to maintain good river environment, it is remarkably important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. Our former research dealing with nutrient emission analysis in the Tone River basin area in Japan, in addition to urban and industrial waste water, nutrient emission from agricultural activity is dominant pollution source into the river system. Japanese style agriculture produces large amount of rice and paddy field occupies large areas in Japanese river basin areas. While paddy field can deteriorate river water quality by outflow of fertilizer, it is also suggested that paddy field has water purification function. As we carried out investigation in the Tone River Basin area, data were obtained which dissolved nitrogen concentration is lower in discharging water from paddy field than inflowing water into the field. Regarding to nutrient emission impact from paddy field, sufficient data are required to discuss quantitatively seasonal change of material behavior including flooding season and dry season, difference of climate condition, soil type, and rice species, to evaluate year round comprehensive impact from paddy field to the river system. In this research, field survey in paddy field and data collection relating rice production were carried out as a preliminary investigation to assess how Japanese style paddy field contributes year round on surface water quality. Study sites are three paddy fields located in upper reach of the Tone River basin area. The fields are flooded from June to September. In 2014, field investigations were carried out three times in flooding period and twice in dry period. To understand characteristics of each paddy field and seasonal tendency accompanying weather of agricultural event, short term investigations were conducted and we prepare for further long term investigation. Each study site has irrigation water inflow and outflow. Two sites have tile drainage system under the field and

Federal Bureau of Investigation (FBI) Field Office Jurisdiction/Divisions

Data.gov (United States)

Department of Homeland Security — This dataset represents the FBI (Federal Bureau of Investigations) national field office jurisdiction/divisional boundary locations. The field offices are centrally...

New technique of insitu soil moisture sampling for environmental isotope analysis applied at 'Pilat-dune' near Bordeaux

International Nuclear Information System (INIS)

Thoma, G.; Esser, N.; Sonntag, C.; Weiss, W.; Rudolph, J.; Leveque, P.

1978-01-01

A new soil-air suction method with soil water vapor adsorption by 4 A-molecular sieve provides soil moisture samples from various depths for environmental isotope analysis and yields soil temperature profiles. A field tritium tracer experiment shows that this insitu sampling method has an isotope profile resolution of about 5-10 cm only. Application of this method in the Pilat sand dune (Bordeaux/France) yielded deuterium and tritium profiles down to 25 meters depth. Bomb tritium measurements of monthly lysimeter percolate samples available since 1961 show that the tritium response has a mean delay of 5 months in case of a sand lysimeter and of 2.5 years for a loess loam lysimeter. A simple HETP model simulates the layered downward movement of soil water and the longitudinal dispersion in the lysimeters. Field capacity and evapotranspiration taken as open parameters yield tritium concentration values of the lysimeters' percolate which are in close agreement with the experimental results. Based on local meteorological data the HETP model applied to tritium tracer experiments in the unsaturated zone further yiels an individual prediction of the momentary tracer position and of the soil moisture distribution. This prediction can be checked experimentally at selected intervals by coring. (orig.) [de

New technique of in-situ soil-moisture sampling for environmental isotope analysis applied at Pilat sand dune near Bordeaux. HETP modelling of bomb tritium propagation in the unsaturated and saturated zones

International Nuclear Information System (INIS)

Thoma, G.; Esser, N.; Sonntag, C.; Weiss, W.; Rudolph, J.; Leveque, P.

1979-01-01

A new soil-air suction method with soil-water vapour adsorption by a 4-A molecular sieve provides soil-moisture samples from various depths for environmental isotope analysis and yields soil temperature profiles. A field tritium tracer experiment shows that this in-situ sampling method has an isotope profile resolution of about 5-10cm only. Application of this method in the Pilat sand dune (Bordeaux/France) yielded deuterium and tritium profiles down to 25m depth. Bomb tritium measurements of monthly lysimeter percolate samples available since 1961 show that the tritium response has a mean delay of five months in the case of a sand lysimeter and of 2.5 years for a loess loam lysimeter. A simple HETP model simulates the layered downward movement of soil water and the longitudinal dispersion in the lysimeters. Field capacity and evapotranspiration taken as open parameters yield tritium concentration values of the lysimeters' percolate which agree well with the experimental results. Based on local meteorological data the HETP model applied to tritium tracer experiments in the unsaturated zone yields in addition an individual prediction of the momentary tracer position and of the soil-moisture distribution. This prediction can be checked experimentally at selected intervals by coring. (author)

Shemya AFB, Alaska 1992 IRP field investigation report

Energy Technology Data Exchange (ETDEWEB)

1993-02-01

The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force's Installation Restoration Program (IRP). As a part of the IRP program, field investigations were performed in 1992 to obtain the information needed to assess what future actions willneed to be carried out at each site. The island's drinking water supply was also investigated. Activities completed at 10 selected sites during the 1992 field investigation included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. In addition, geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal to be avoided during drilling activities.

Effect of the Presence of Nonionic Surfactant Brij35 on the Mobility of Metribuzin in Soil

Directory of Open Access Journals (Sweden)

Eman M. ElSayed

2013-04-01

Full Text Available Given the water scarcity becoming endemic to a large portion of the globe, arid region irrigation has resorted to the use of treated, partially treated, or even untreated wastewaters. Such waters contain a number of pollutants, including surfactants. Applied to agricultural lands, these surfactants could affect the fate and transport of other chemicals in the soil, particularly pesticides. A field lysimeter study was undertaken to investigate the effect of nonionic surfactant, Brij35, on the in-soil fate and transport of a commonly used herbicide, metribuzin [4-amino-6-tert-butyl-3-(methylthio-1,2,4-triazin-5(4H-one]. Nine PVC lysimeters, 1.0 m long × 0.45 m diameter, were packed with a sandy soil to a bulk density of 1.35 mg m−3. Antibiotic-free cattle manure was applied (10 mg ha−1 at the surface of the lysimeters. Metribuzin was then applied to the soil surface of all lysimeters at a rate of 1.00 kg a.i. ha−1. Each of three aqueous Brij35 solutions, 0, 0.5 and 5 mg L−1 (i.e., “good”, “poor” and “very poor” quality irrigation water were each applied to the lysimeters in triplicate. Analysis for metribuzin residues in samples of both soil and leachate, collected over a 90-day period, showed the surfactant Brij35 to have increased the mobility of metribuzin in soil, indicating that continued use of poor quality water could influence pesticide transport in agricultural soils, and increase the risk of groundwater contamination.

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

Radiological field exercises for forensic investigators. Technical memorandum

International Nuclear Information System (INIS)

Larsson, C.L.; Clement, C.; Estan, D.; McDiarmid, C.; Tessier, M.

2006-06-01

A series of tabletop and field exercises were designed and executed to test traditional forensic investigation procedures in a crime scene with radioactive material present. This allowed for specific training needs of forensic identification specialists to be identified and revised procedures to be drafted. Two scenarios were exercised, first as tabletop discussions with the Royal Canadian Mounted Police (RCMP), the Canadian Nuclear Safety Commission (CNSC), and DRDC Ottawa, and then as field exercises with the participation of the RCMP and Ottawa Police Services (OPS) forensic investigators. These exercises produced a number of lessons learned with regard to protocols for forensic investigators and led to the development of a one-page fact sheet on performing forensic identification tasks in a radiation environment. (author)

The ARASE (ERG) magnetic field investigation

Science.gov (United States)

Matsuoka, Ayako; Teramoto, Mariko; Nomura, Reiko; Nosé, Masahito; Fujimoto, Akiko; Tanaka, Yoshimasa; Shinohara, Manabu; Nagatsuma, Tsutomu; Shiokawa, Kazuo; Obana, Yuki; Miyoshi, Yoshizumi; Mita, Makoto; Takashima, Takeshi; Shinohara, Iku

2018-03-01

The fluxgate magnetometer for the Arase (ERG) spacecraft mission was built to investigate particle acceleration processes in the inner magnetosphere. Precise measurements of the field intensity and direction are essential in studying the motion of particles, the properties of waves interacting with the particles, and magnetic field variations induced by electric currents. By observing temporal field variations, we will more deeply understand magnetohydrodynamic and electromagnetic ion-cyclotron waves in the ultra-low-frequency range, which can cause production and loss of relativistic electrons and ring-current particles. The hardware and software designs of the Magnetic Field Experiment (MGF) were optimized to meet the requirements for studying these phenomena. The MGF makes measurements at a sampling rate of 256 vectors/s, and the data are averaged onboard to fit the telemetry budget. The magnetometer switches the dynamic range between ± 8000 and ± 60,000 nT, depending on the local magnetic field intensity. The experiment is calibrated by preflight tests and through analysis of in-orbit data. MGF data are edited into files with a common data file format, archived on a data server, and made available to the science community. Magnetic field observation by the MGF will significantly improve our knowledge of the growth and decay of radiation belts and ring currents, as well as the dynamics of geospace storms.

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

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.

Laboratory and Field Investigations of Small Crater Repair Technologies

National Research Council Canada - National Science Library

Priddy, Lucy P; Tingle, Jeb S; McCaffrey, Timothy J; Rollings, Ray S

2007-01-01

.... This airfield damage repair (ADR) investigation consisted of laboratory testing of selected crater fill and capping materials, as well as full-scale field testing of small crater repairs to evaluate field mixing methods, installation...

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.

Evaluation of the performance of solidified commercial low-level wastes in an arid climate

International Nuclear Information System (INIS)

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

1984-01-01

Shallow land burial is being used as a disposal method for commercial low-level waste at waste disposal sites in arid (Hanford, Washington) and humid (Barnwell, South Carolina) climatic regions. A field lysimeter facility has been established at Hanford in which to conduct waste-form leaching tests. The primary objective of this research is to determine typical source terms generated by commercial solidified low-level wastes. The field lysimeter facility consists of 10, 3 M deep by 1.8 M diameter, closed-bottomed lysimeters around a central 4 M deep by 4 M diameter instrument caisson. Commercial cement and dow polymer waste samples were removed from 210 L drums and placed in the 1.8 M diameter lysimeters. Two bitumen samples are planned to be emplaced in the facility this year. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste forms. Suction candles (ceramic cups) placed around the waste will be used to periodically collect soil water samples for chemical analysis. Meteorological data, moisture content, and soil temperature are being 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, concentrations and distributions of radionuclides in the waste streams, and concentrations of hydrophilic organic species in one of the waste streams

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

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

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

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

Leaching and soil/groundwater transport of contaminants from coal combustion residues

International Nuclear Information System (INIS)

Hjelmar, O.; Hansen, E.A.; Larsen, F.; Thomassen, H.

1992-01-01

In this project the results of accelerated laboratory leaching tests on coal fly ash and flue gas desulfurization (FGD) products from the spray dryer absorption process (SDA) were evaluated by comparison to the results of large scale lysimeter leaching tests on the same residues. The mobility of chromium and molybdenum - two of the kev contaminants of coal combustion residue leachates - in various typical soil types was investigated by batch and column methods in the laboratory. Some of the results were confirmed by field observations at an old coal fly ash disposal site and by a lysimeter attenuation test with coal fly ash leachate on a clayed till. A large number of groundwater transport models and geochemical models were reviewed, and two of the models (Gove-Stollenwerk and CHMTRNS) were modified and adjusted and used to simulate column attenuation tests performed in the laboratory. One of the models (Grove-Stollenwerk) was used to illustrate a recommended method of environmental impact assessment, using lysimeter leaching data and laboratory column attenuation data to describe the emission and migration of Mo from a coal fly ash disposal site

Results of verification and investigation of wind velocity field forecast. Verification of wind velocity field forecast model

International Nuclear Information System (INIS)

Ogawa, Takeshi; Kayano, Mitsunaga; Kikuchi, Hideo; Abe, Takeo; Saga, Kyoji

1995-01-01

In Environmental Radioactivity Research Institute, the verification and investigation of the wind velocity field forecast model 'EXPRESS-1' have been carried out since 1991. In fiscal year 1994, as the general analysis, the validity of weather observation data, the local features of wind field, and the validity of the positions of monitoring stations were investigated. The EXPRESS which adopted 500 m mesh so far was improved to 250 m mesh, and the heightening of forecast accuracy was examined, and the comparison with another wind velocity field forecast model 'SPEEDI' was carried out. As the results, there are the places where the correlation with other points of measurement is high and low, and it was found that for the forecast of wind velocity field, by excluding the data of the points with low correlation or installing simplified observation stations to take their data in, the forecast accuracy is improved. The outline of the investigation, the general analysis of weather observation data and the improvements of wind velocity field forecast model and forecast accuracy are reported. (K.I.)

Evaluation of the performance of solidified commercial low-level wastes in an arid climate

International Nuclear Information System (INIS)

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

1984-09-01

Shallow land burial is being used as a disposal method for commercial low-level waste at waste disposal sites in arid (Hanford site near Richland, Washington) and humid (Barnwell, South Carolina) climatic regions. A field lysimeter facility has been established at the Hanford site in which to conduct waste-form leaching tests. The primary objective of this research is to determine typical source terms generated by commercial solidified low-level wastes. The field lysimeter facility consists of ten 3-m-deep by 1.8-m-diameter, closed-bottom lysimeters around a central instrument caisson, 4 m in diameter. Commercial cement and vinyl ester-styrene waste samples were removed from 210-L drums and placed in the 1.8-m-diameter lysimeters. Two bitumen samples are planned to be emplaced in the facility in 1984. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste forms. Suction candles (ceramic cups) placed around the waste will be used to periodically collect soil water samples for chemical analysis. Meteorological data, 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, concentrations and distributions of radionuclides in the waste forms, concentrations of radionuclides in the waste streams, and concentrations of hydrophilic organic species in one of the waste steams. 8 references, 3 figures, 5 tables

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.

Experimental Investigation of Integrated Optical Intensive Impulse Electric Field Sensors

International Nuclear Information System (INIS)

Bao, Sun; Fu-Shen, Chen

2009-01-01

We design and fabricate an integrated optical electric field sensor with segmented electrode for intensive impulse electric field measurement. The integrated optical sensor is based on a Mach–Zehnder interferometer with segmented electrodes. The output/input character of the sensing system is analysed and measured. The maximal detectable electric field range (−75 kV/m to 245 kV/m) is obtained by analysing the results. As a result, the integrated optics electric field sensing system is suitable for transient intensive electric field measurement investigation

Radionuclide migration studies at the Savannah River Plant humid shallow land burial site for low-level waste

International Nuclear Information System (INIS)

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

1984-01-01

A program of field, laboratory, and modeling studies for the Savannah River Plant low-level waste burial ground has been conducted for several years. The studies provide generic data on an operating shallow land burial site in a humid region. Recent results from individual studies on subsurface monitoring, lysimeter tests, soil-water chemistry, and transport modeling are reported. Monitoring continues to show little movement of radionuclides except tritium. Long-term lysimeter tests with a variety of defense wastes measure migration under controlled field conditions. One lysimeter was excavated to study radionuclide distribution on the soil column beneath the waste. New soil-water distribution coefficients (K/sub d/) were measured for Co-60, Sr-90, Ru-106, Sb-125, and I-129. Laboratory and field data are integrated by means of the SRL dose-to-man model, to evaluate effects of alternative disposal practices. The model recently has been used to evaluate TRU disposal criteria and to predict migration behavior of tritium, Tc-99, and I-129. 14 references, 2 tables

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...

Isotope Investigations of Groundwater Movement in a Coarse Gravel Unsaturated Zone

Energy Technology Data Exchange (ETDEWEB)

Mali, N. [Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia); Kozar-Logar, J. [Jozef Stefan Institute, Ljubljana (Slovenia); Leis, A. [Institute of Water Resources Management, Hydrogeology and Geophysics, Joanneum Research Forschungsgesellschaft mbH, Graz (Austria)

2013-07-15

The unsaturated zone above an aquifer serves as a water reservoir which discharges water and possible pollution to the saturated zone. This paper presents the application of oxygen-18 and tritium isotope methods in the study of groundwater transport processes in the unsaturated zone of Selniska Dobrava coarse gravel aquifer. The Selniska Dobrava gravel aquifer is an important water resource for Maribor and its surroundings, therefore the determination of transport processes in the unsaturated zone is important regarding its protection. Groundwater flow characteristics were estimated using isotopes and based on experimental work in a lysimeter. Tritium investigation results were compared with the results of long term oxygen-18 isotope investigation. In this paper the analytical approach, results and interpretation of {delta}{sup 18}O and tritium measurements in the unsaturated zone are presented. (author)

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.

Progress with field investigations at Stripa

International Nuclear Information System (INIS)

Witherspoon, P.A.; Cook, N.G.W.; Gale, J.E.

1980-02-01

It is generally agreed that the most practicable method of isolating nuclear wastes from the biosphere is by deep burial in suitable geologic formations. Such burial achieves a high degree of physical isolation but raises questions concerning the rate at which some of these wastes may return to the biosphere through transport by groundwater. Any suitable repository site will be disturbed first by the excavation of the repository and second by the thermal pulse caused by the radioactive decay of the wastes. To assess the effectiveness of geologic isolation it is necessary to develop the capability of predicting the response of a rock mass to such a thermal pulse. Ultimately, this requires field measurements at depths below surface and in media representative of those likely to be encountered at an actual repository. Access to a granitic rock mass adjacent to a defunct iron ore mine at Stripa in Sweden at a depth of about 350 m below surface has provided a unique opportunity to conduct a comprehensive suite of hydrological and thermo-mechanical experiments under such conditions virtually without delay. The results of these field tests have shown the importance of geologic structure and the functional dependence of the thermo-mechanical properties on temperature in developing a valid predictive model. The results have also demonstrated the vital importance of being able to carry out large scale investigations in a field test facility

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.

Numerical Investigation of Ultrafast interaction between THz Fields and Crystalline Materials

DEFF Research Database (Denmark)

Pedersen, Pernille Klarskov; Clark, Stewart J.; Jepsen, Peter Uhd

2014-01-01

We present a quantum - mechanical molecular dynamics investigation of the interaction between strong single - cyc le THz pulses and ionic crystals . We find nonlinearities in the response of the CsI crystals at field strengths higher than 10 MV/cm.......We present a quantum - mechanical molecular dynamics investigation of the interaction between strong single - cyc le THz pulses and ionic crystals . We find nonlinearities in the response of the CsI crystals at field strengths higher than 10 MV/cm....

Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

Energy Technology Data Exchange (ETDEWEB)

Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

1995-03-01

The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

Graphene as a local probe to investigate near-field properties of plasmonic nanostructures

Science.gov (United States)

Wasserroth, Sören; Bisswanger, Timo; Mueller, Niclas S.; Kusch, Patryk; Heeg, Sebastian; Clark, Nick; Schedin, Fredrik; Gorbachev, Roman; Reich, Stephanie

2018-04-01

Light interacting with metallic nanoparticles creates a strongly localized near-field around the particle that enhances inelastic light scattering by several orders of magnitude. Surface-enhanced Raman scattering describes the enhancement of the Raman intensity by plasmonic nanoparticles. We present an extensive Raman characterization of a plasmonic gold nanodimer covered with graphene. Its two-dimensional nature and energy-independent optical properties make graphene an excellent material for investigating local electromagnetic near-fields. We show the localization of the near-field of the plasmonic dimer by spatial Raman measurements. Energy- and polarization-dependent measurements reveal the local near-field resonance of the plasmonic system. To investigate the far-field resonance we perform dark-field spectroscopy and find that near-field and far-field resonance energies differ by 170 meV, much more than expected from the model of a damped oscillator (40 meV).

INVESTIGATION OF ELECTROMAGNETIC FIELDS IN RESIDENTIAL AREAS

Directory of Open Access Journals (Sweden)

Dušan MEDVEĎ

2017-09-01

Full Text Available This article is devoted to investigation of impact of electromagnetic fields around the electrical equipment used in a residential area and their impact on the human body. This paper was based on sets of measurements of magnetic induction B with magnetometer and on computational simulations in ANSYS for particular appliances often used in household. The results from measurements and simulations led to setting out the recommendations for practical action in the form of elimination of harmful electromagnetic radiation.

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.

A balloon-borne experiment to investigate the Martian magnetic field

Science.gov (United States)

Schwingenschuh, K.; Feldhofer, H.; Koren, W.; Jernej, I.; Stachel, M.; Riedler, W.; Slamanig, H.; Auster, H.-U.; Rustenbach, J.; Fornacon, H. K.; Schenk, H. J.; Hillenmaier, O.; Haerendel, G.; Yeroshenko, Ye.; Styashkin, V.; Zaroutzky, A.; Best, A.; Scholz, G.; Russell, C. T.; Means, J.; Pierce, D.; Luhmann, J. G.

1996-03-01

The Space Research Institute of the Austrian Academy, of Sciences (Graz, Austria) in cooperation with MPE (Berlin, Germany), GFZ Potsdam (Obs. Niemegk, Germany) IZMIRAN/IOFAN (Moscow, Russian) and IGPP/UCLA (Los Angeles, USA) is designing the magnetic field experiment MAGIBAL (MAGnetic field experiment aboard a martian BALloon) to investigate the magnetic field on the surface of Mars. The dual sensor fluxgate magnetometer is part of the MARS-98/MARS-TOGETHER balloon payload. During a ten days period the balloon will float over a distance of about 2000 km at altitudes between 0 and 4 km. Due to the limited power and telemetry allocation the magnetometer can transmit only one vector per ten seconds and spectral information in the frequency range from 2 - 25 Hz. The dynamic range is +/- 2000 nT. The main scientific objectives of the experiment are: • Determination of the magnetism of the Martian rocks • Investigation of the leakage of the solar wind induced magnetosphere using the correlation between orbiter and balloon observations • Measurement of the magnetic field profile between the orbiter and the surface of Mars during the descent phase of the balloon. Terrestrial test flights with a hot air balloon were performed in order to test the original MAGIBAL equipment under balloon flight conditions.

Poly-use multi-level sampling system for soil-gas transport analysis in the vadose zone.

Science.gov (United States)

Nauer, Philipp A; Chiri, Eleonora; Schroth, Martin H

2013-10-01

Soil-gas turnover is important in the global cycling of greenhouse gases. The analysis of soil-gas profiles provides quantitative information on below-ground turnover and fluxes. We developed a poly-use multi-level sampling system (PMLS) for soil-gas sampling, water-content and temperature measurement with high depth resolution and minimal soil disturbance. It is based on perforated access tubes (ATs) permanently installed in the soil. A multi-level sampler allows extraction of soil-gas samples from 20 locations within 1 m depth, while a capacitance probe is used to measure volumetric water contents. During idle times, the ATs are sealed and can be equipped with temperature sensors. Proof-of-concept experiments in a field lysimeter showed good agreement of soil-gas samples and water-content measurements compared with conventional techniques, while a successfully performed gas-tracer test demonstrated the feasibility of the PMLS to determine soil-gas diffusion coefficients in situ. A field application of the PMLS to quantify oxidation of atmospheric CH4 in a field lysimeter and in the forefield of a receding glacier yielded activity coefficients and soil-atmosphere fluxes well in agreement with previous studies. With numerous options for customization, the presented tool extends the methodological choices to investigate soil-gas transport in the vadose zone.

Investigation of acoustic field near to elastic thin plate using integral method

Directory of Open Access Journals (Sweden)

В.І. Токарев

2004-01-01

Full Text Available  Investigation of acoustic field near to elastic thin plate using  integral method The influence of boundary conditions on sound wave propagation, radiation and transmission through thin elastic plate is investigated. Necessary for that numerical model was found using the Helmholtz equation and equation of oscilated plate by means of integral formulation of the solution for acoustic fields near to elastic thin plate and for bending waves of small amplitudes.

The Vector Electric Field Investigation on the C/NOFS Satellite

Science.gov (United States)

Pfaff, R.; Acuna, M.; Kujawski, J.; Fourre, R.; Uribe, P.; Hunsaker, F.; Rowland, D.; Le, G.; Farrell, W.; Maynard, N.;

Improvements to measuring water flux in the vadose zone.

Science.gov (United States)

Masarik, Kevin C; Norman, John M; Brye, Kristofor R; Baker, John M

2004-01-01

Evaluating the impact of land use practices on ground water quality has been difficult because few techniques are capable of monitoring the quality and quantity of soil water flow below the root zone without disturbing the soil profile and affecting natural flow processes. A recently introduced method, known as equilibrium tension lysimetry, was a major improvement but it was not a true equilibrium since it still required manual intervention to maintain proper lysimeter suction. We addressed this issue by developing an automated equilibrium tension lysimeter (AETL) system that continuously matches lysimeter tension to soil-water matric potential of the surrounding soil. The soil-water matric potential of the bulk soil is measured with a heat-dissipation sensor, and a small DC pump is used to apply suction to a lysimeter. The improved automated approach reported here was tested in the field for a 12-mo period. Powered by a small 12-V rechargeable battery, the AETLs were able to continuously match lysimeter suction to soil-water matric potential for 2-wk periods with minimal human attention, along with the added benefit of collecting continuous soil-water matric potential data. We also demonstrated, in the laboratory, methods for continuous measurement of water depth in the AETL, a capability that quantifies drainage on a 10-min interval, making it a true water-flux meter. Equilibrium tension lysimeters have already been demonstrated to be a reliable method of measuring drainage flux, and the further improvements have created a more effective device for studying water drainage and chemical leaching through the soil matrix.

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...

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...

Investigation of material properties by NMR in low and high magnetic fields

International Nuclear Information System (INIS)

Rata, D.G.

2006-01-01

In this work the experiments have been performed at both low and high field. The experiments cover various domains from simple relaxation experiments in low field to diffusion and spin-diffusion in high field. The applications of low-field investigations are: - quality control of chemical products. - water content determination inside of the walls of buildings. - determination of multilayer polymer coatings on a concrete. In high-field NMR several alkane molecules swollen at equilibrium in cross-linked natural rubber samples have been investigated and analyzed based on the assumptions of the Vrentras theory. A small diffusion anisotropy of the order of 10% has been discovered because of a deformation of free volume under compression. The anisotropy increases with the cross-link density and the compression ratio. The results presented in this study show that the solvent size influences the anisotropy of the diffusion process through the size parameter. The spin-diffusion measurements have been performed on Stanyl samples with different aged samples, at controlled temperature conditions. (orig.)

Investigation of material properties by NMR in low and high magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Rata, D.G.

2006-07-10

In this work the experiments have been performed at both low and high field. The experiments cover various domains from simple relaxation experiments in low field to diffusion and spin-diffusion in high field. The applications of low-field investigations are: - quality control of chemical products. - water content determination inside of the walls of buildings. - determination of multilayer polymer coatings on a concrete. In high-field NMR several alkane molecules swollen at equilibrium in cross-linked natural rubber samples have been investigated and analyzed based on the assumptions of the Vrentras theory. A small diffusion anisotropy of the order of 10% has been discovered because of a deformation of free volume under compression. The anisotropy increases with the cross-link density and the compression ratio. The results presented in this study show that the solvent size influences the anisotropy of the diffusion process through the size parameter. The spin-diffusion measurements have been performed on Stanyl samples with different aged samples, at controlled temperature conditions. (orig.)

Loss pathways of N-nitrosodimethylamine (NDMA) in turfgrass soils.

Science.gov (United States)

Arienzo, M; Gan, J; Ernst, F; Qin, S; Bondarenko, S; Sedlak, D L

2006-01-01

N-nitrosodimethylamine (NDMA) is a potent carcinogen that is often present in municipal wastewater effluents. In a previous field study, it was observed that NDMA did not leach through turfgrass soils following 4 mo of intensive irrigation with NDMA-containing wastewater effluent. To better understand the loss pathways for NDMA in landscape irrigation systems, a mass balance approach was employed using in situ lysimeters treated with 14C-NDMA. When the lysimeters were subjected to irrigation and field conditions after NDMA application, very rapid dissipation of NDMA was observed for both types of soil used in the field plots. After only 4 h, total 14C activity in the lysimeters decreased to 19.1 to 26.1% of the applied amount, and less than 1% of the activity was detected below the 20-cm depth. Analysis of plant materials showed that less than 3% of the applied 14C was incorporated into the plants, suggesting only a minor role for plant uptake in removing NDMA from the vegetated soils. The rapid dissipation and limited downward movement of NDMA in the in situ lysimeters was consistent with the negligible leaching observed in the field study, and suggests volatilization as the only significant loss pathway. This conclusion was further corroborated by rapid NDMA volatilization found from water or a thin layer of soil under laboratory conditions. In a laboratory incubation experiment, prolonged wastewater irrigation did not result in enhanced NDMA degradation in the soil. Therefore, although NDMA may be present at relatively high levels in treated wastewater, gaseous diffusion and volatilization in unsaturated soils may effectively impede significant leaching of NDMA, minimizing the potential for ground water contamination from irrigation with treated wastewater.

Shemya AFB, Alaska 1992 IRP field investigation report

Energy Technology Data Exchange (ETDEWEB)

1993-02-01

The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force's Installation Restoration Program (IRP). Field investigations were performed in 1992 to obtain the information needed to assess what future actions will need to be carried out at each site. The island's drinking water supply was also investigated. Activities completed at 10 selected sites included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. Geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal to be avoided during drilling activities. This report, appendices B, C, and D contains information on the following: geophysical contour maps and profile plots; human health risk assessment; and ecological risk assessment.

Shemya AFB, Alaska 1992 IRP field investigation report

Energy Technology Data Exchange (ETDEWEB)

1993-02-01

The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force's Installation Restoration Program (IRP). Field investigations were performed in 1992 to obtain the information needed to assess what future actions will need to be carried out at each site. The island's drinking water supply was also investigated. Activities completed at 10 selected sites included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. In addition, geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal, to be avoided during drilling activities. This report contains appendices E and F with information on the following: soil boring logs, and data validation of samples analyzed.

Investigations of Tunneling for Field Effect Transistors

OpenAIRE

Matheu, Peter

2012-01-01

Over 40 years of scaling dimensions for new and continuing product cycles has introduced new challenges for transistor design. As the end of the technology roadmap for semiconductors approaches, new device structures are being investigated as possible replacements for traditional metal-oxide-semiconductor field effect transistors (MOSFETs). Band-to-band tunneling (BTBT) in semiconductors, often viewed as an adverse effect of short channel lengths in MOSFETs, has been discussed as a promising ...

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.

Performance of a buried radioactive high level waste (HLW) glass after 24 years

International Nuclear Information System (INIS)

Jantzen, Carol M.; Kaplan, Daniel I.; Bibler, Ned E.; Peeler, David K.; John Plodinec, M.

2008-01-01

A radioactive high level waste glass was made in 1980 with Savannah River Site (SRS) Tank 15 waste. This glass was buried in a lysimeter in the SRS burial ground for 24 years. Lysimeter leachate data was available for the first 8 years. The glass was exhumed in 2004. The glass was predicted to be very durable and laboratory tests confirmed this. Scanning electron microscopy of the glass burial surface showed no significant glass alteration consistent with results of other laboratory and field tests. Radionuclide profiling for alpha, beta, and 137 Cs indicated that Pu was not enriched in the soil while 137 Cs and 9 deg. C Sr were enriched in the first few centimeters surrounding the glass. Lysimeter leachate data indicated that 9 deg. C Sr and 137 Cs leaching from the glass was diffusion controlled

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.

Shemya AFB, Alaska 1992 IRP field investigation report. Volume 1: Final report

Energy Technology Data Exchange (ETDEWEB)

1993-02-01

The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force`s Installation Restoration Program (IRP). As a part of the IRP program, field investigations were performed in 1992 to obtain the information needed to assess what future actions willneed to be carried out at each site. The island`s drinking water supply was also investigated. Activities completed at 10 selected sites during the 1992 field investigation included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. In addition, geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal to be avoided during drilling activities.

[Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 5, Field Investigation report

Energy Technology Data Exchange (ETDEWEB)

1992-03-01

An environmental investigation of ground water conditions has been undertaken at Wright-Patterson Air Force Base (WPAFB), Ohio to obtain data to assist in the evaluation of a potential removal action to prevent, to the extent practicable, migration of the contaminated ground water across Base boundaries. Field investigations were limited to the central section of the southwestern boundary of Area C and the Springfield Pike boundary of Area B. Further, the study was limited to a maximum depth of 150 feet below grade. Three primary activities of the field investigation were: (1) installation of 22 monitoring wells, (2) collection and analysis of ground water from 71 locations, (3) measurement of ground water elevations at 69 locations. Volatile organic compounds including trichloroethylene, perchloroethylene, and/or vinyl chloride were detected in concentrations exceeding Maximum Contaminant Levels (MCL) at three locations within the Area C investigation area. Ground water at the Springfield Pike boundary of Area B occurs in two primary units, separated by a thicker-than-expected clay layers. One well within Area B was determined to exceed the MCL for trichloroethylene.

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.

Asteroseismic Investigation of Known Planet Hosts in the Kepler Field

DEFF Research Database (Denmark)

Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; Brown, T. M.

2010-01-01

Asteroseismic Investigation of Known Planet Hosts in the Kepler Field .a{background-color: #ffff88}.h{background-color: #ffff00}.b{background-color: #ccccff}.i{background-color: #3333ff}.c{background-color: #ffcccc}.j{background-color: #ff3333}.d{background-color: #bbffff}.k{background-color: #00...

Doping kinetics of organic semiconductors investigated by field-effect transistors

NARCIS (Netherlands)

Maddalena, F.; Meijer, E.J.; Asadi, K.; Leeuw, D.M. de; Blom, P.W.M.

2010-01-01

The kinetics of acid doping of the semiconductor regioregular poly-3-hexylthiophene with vaporized chlorosilane have been investigated using field-effect transistors. The dopant density has been derived as a function of temperature and exposure time from the shift in the pinch-off voltage, being the

Investigating oiled birds from oil field waste pits

International Nuclear Information System (INIS)

Gregory, D.G.; Edwards, W.C.

1991-01-01

Procedures and results of investigations concerning the oiling of inland raptors, migratory water-fowl and other birds are presented. Freon washings from the oiled birds and oil from the pits were analyzed by gas chromatography. In most instances the source of the oil could be established by chromatographic procedures. The numbers of birds involved (including many on the endangered species list) suggested the need for netting or closing oil field waste pits and mud disposal pits. Maintaining a proper chain of custody was important

Source evaluation report phase 2 investigation: Limited field investigation. Final report: United States Air Force Environmental Restoration Program, Eielson Air Force Base, Alaska

Energy Technology Data Exchange (ETDEWEB)

1994-10-01

This report describes the limited field investigation work done to address issues and answer unresolved questions regarding a collection of potential contaminant sources at Eielson Air Force Base (AFB), near Fairbanks, Alaska. These sources were listed in the Eielson AFB Federal Facility Agreement supporting the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) cleanup of the base. The limited field investigation began in 1993 to resolve all remaining technical issues and provide the data and analysis required to evaluate the environmental hazard associated with these sites. The objective of the limited field investigation was to allow the remedial project managers to sort each site into one of three categories: requiring remedial investigation/feasibility study, requiring interim removal action, or requiring no further remedial action.

Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact

DEFF Research Database (Denmark)

Larsen, Elfinn; Kjeldgaard, K.

1973-01-01

The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...

Investigation of drag effect using the field signature method

International Nuclear Information System (INIS)

Wan, Zhengjun; Liao, Junbi; Tian, Gui Yun; Cheng, Liang

2011-01-01

The potential drop (PD) method is an established non-destructive evaluation (NDE) technique. The monitoring of internal corrosion, erosion and cracks in piping systems, based on electrical field mapping or direct current potential drop array, is also known as the field signature method (FSM). The FSM has been applied in the field of submarine pipe monitoring and land-based oil and gas transmission pipes and containers. In the experimental studies, to detect and calculate the degree of pipe corrosion, the FSM analyses the relationships between the electrical resistance and pipe thickness using an electrode matrix. The relevant drag effect or trans-resistance will cause a large margin of error in the application of resistance arrays. It is the first time that the drag effect in the paper is investigated and analysed in resistance networks with the help of the FSM. Subsequently, a method to calculate the drag factors and eliminate its errors is proposed and presented. Theoretical analysis, simulation and experimental results show that the measurement accuracy can be improved by eliminating the errors caused by the drag effect

An overview of the geochemical code MINTEQ: Applications to performance assessment for low-level wastes

International Nuclear Information System (INIS)

Peterson, S.R.; Opitz, B.E.; Graham, M.J.; Eary, L.E.

1987-03-01

The MINTEQ geochemical computer code, developed at the Pacific Northwest Laboratory (PNL), integrates many of the capabilities of its two immediate predecessors, MINEQL and WATEQ3. The MINTEQ code will be used in the Special Waste Form Lysimeters-Arid program to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments of the interaction of ground water with solidified low-level wastes. The code can calculate ion speciation/solubilitya, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial, solidified low-level wastes. The wastes being evaluated include power-reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code was upgraded preparatory to performing the geochemical modeling. Thermodynamic data for solid phases and aqueous species containing Sb, Ce, Cs, or Co were added to the MINTEQ database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the waste forms predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partial field validation of the geochemical model

An investigation into the induced electric fields from transcranial magnetic stimulation

Science.gov (United States)

Hadimani, Ravi; Lee, Erik; Duffy, Walter; Waris, Mohammed; Siddiqui, Waquar; Islam, Faisal; Rajamani, Mahesh; Nathan, Ryan; Jiles, David; David C Jiles Team; Walter Duffy Collaboration

Transcranial magnetic stimulation (TMS) is a promising tool for noninvasive brain stimulation that has been approved by the FDA for the treatment of major depressive disorder. To stimulate the brain, TMS uses large, transient pulses of magnetic field to induce an electric field in the head. This transient magnetic field is large enough to cause the depolarization of cortical neurons and initiate a synaptic signal transmission. For this study, 50 unique head models were created from MRI images. Previous simulation studies have primarily used a single head model, and thus give a limited image of the induced electric field from TMS. This study uses finite element analysis simulations on 50 unique, heterogeneous head models to better investigate the relationship between TMS and the electric field induced in brain tissues. Results showed a significant variation in the strength of the induced electric field in the brain, which can be reasonably predicted by the distance from the TMS coil to the stimulated brain. Further, it was seen that some models had high electric field intensities in over five times as much brain volume as other models.

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.

Investigation of Condensed Media in Weak Fields by the Method of Nuclear Magnetic Resonance

Science.gov (United States)

Davydov, V. V.; Myazin, N. S.; Dudkin, V. I.; Velichko, E. N.

2018-05-01

A compact design of a rapid-response nuclear magnetic spectrometer for investigation of condensed media in weak fields is reported. As a result of investigation of different condensed media, special features of recording a nuclear magnetic resonance (NMR) signal in a weak magnetic field from a small volume of the medium under study are established. For the first time the NMR absorption spectra of condensed media in a weak field are collected. Based on the results of experimental studies, the potential of using a compact NMR-spectrometer for condensed media monitoring in a rapid response mode is determined.

Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

International Nuclear Information System (INIS)

Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A.; Patton, T. L.; Prasad, S.; Quinn, J.; Rosenblatt, D. H.; Vercellone, J.; Wang, Y. Y.

2000-01-01

This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field

Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

Energy Technology Data Exchange (ETDEWEB)

Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A.; Patton, T. L.; Prasad, S.; Quinn, J.; Rosenblatt, D. H.; Vercellone, J.; Wang, Y. Y.

2000-03-14

This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field.

Investigation of Vacuum Arc Voltage Characteristics Under Different Axial Magnetic Field Profiles

International Nuclear Information System (INIS)

Jia Shenli; Song Xiaochuan; Huo Xintao; Shi Zongqian; Wang Lijun

2010-01-01

Characteristics of the arc voltage under different profiles of axial magnetic field were investigated experimentally in a detachable vacuum chamber with five pairs of specially designed electrodes generating both bell-shaped and saddle-shaped magnetic field profile. The arc column and cathode spot images were photographed by a high speed digital camera. The dependence of the arc voltage on arcing evolution is analyzed. It is indicated that the axial magnetic field profile could affect the arc behaviors significantly, and the arc voltage is closely related to the arc light intensity.

Soil-plant-transfer factors for I-129 and pasture vegetation

International Nuclear Information System (INIS)

Haisch, A.; Schuettelkopf, H.

1993-07-01

The transfer factors for soil/plant, I-129 and I-127 and pasture vegetation have been measured with soils developed by wethering of granite, jura and cretaceous formations. Greenhouse (Karlsruhe) and field experiments (Munich) have been performed using lysimeters. Three ground water levels and the influence of a six weeks flooding was measured. About 90% of the transfer factors ranged from 0.000 to 0.020. The highest values have been determined with soils from granite wethering. The flooding of the lysimeters caused an important increase of the transfer factors after the end of flooding. (orig.) [de

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)

Rock sealing - large scale field test and accessory investigations

International Nuclear Information System (INIS)

Pusch, R.

1988-03-01

The experience from the pilot field test and the basic knowledge extracted from the lab experiments have formed the basis of the planning of a Large Scale Field Test. The intention is to find out how the 'instrument of rock sealing' can be applied to a number of practical cases, where cutting-off and redirection of groundwater flow in repositories are called for. Five field subtests, which are integrated mutually or with other Stripa projects (3D), are proposed. One of them concerns 'near-field' sealing, i.e. sealing of tunnel floors hosting deposition holes, while two involve sealing of 'disturbed' rock around tunnels. The fourth concerns sealing of a natural fracture zone in the 3D area, and this latter test has the expected spin-off effect of obtaining additional information on the general flow pattern around the northeastern wing of the 3D cross. The fifth test is an option of sealing structures in the Validation Drift. The longevity of major grout types is focussed on as the most important part of the 'Accessory Investigations', and detailed plans have been worked out for that purpose. It is foreseen that the continuation of the project, as outlined in this report, will yield suitable methods and grouts for effective and long-lasting sealing of rock for use at stategic points in repositories. (author)

Investigations on field-effect transistors based on two-dimensional materials

Energy Technology Data Exchange (ETDEWEB)

Finge, T.; Riederer, F.; Grap, T.; Knoch, J. [Institute of Semiconductor Electronics, RWTH Aachen University (Germany); Mueller, M.R. [Institute of Semiconductor Electronics, RWTH Aachen University (Germany); Infineon Technologies, Villach (Austria); Kallis, K. [Intelligent Microsystems Chair, TU Dortmund University (Germany)

2017-11-15

In the present article, experimental and theoretical investigations regarding field-effect transistors based on two-dimensional (2D) materials are presented. First, the properties of contacts between a metal and 2D material are discussed. To this end, metal-to-graphene contacts as well to transition metal dichalcogenides (TMD) are studied. Whereas metal-graphene contacts can be tuned with an appropriate back-gate, metal-TMD contacts exhibit strong Fermi level pinning showing substantially limited maximum possible drive current. Next, tungsten diselenide (WSe{sub 2}) field-effect transistors are presented. Employing buried-triple-gate substrates allows tuning source, channel and drain by applying appropriate gate voltages so that the device can be reconfigured to work as n-type, p-type and as so-called band-to-band tunnel field-effect transistor on the same WSe{sub 2} flake. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Installation for microwave investigations of high-temperature superconductivity in magnetic field

CERN Document Server

Akhvlediani, I G; Mamniashvili, G I; Chigvinadze, D G

2002-01-01

Paper describes advanced EPR-spectrometer RE 1306 designed to investigate into structure of magnetic flux in high-temperature superconductors (HTSC). To measure in low fields one uses power source generating current within 0-600 mA limits and 10-500 Gauss field. To ensure temperature studies of HTSC within up to approx 15 K range one used helium and nitrogen cold steam blowing through resonator of EPR-spectrometer. To stabilize specimen temperature prior to cold steams enter double tube one fixed one more heater

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

Evaluation of small scale laboratory and pot experiments to determine realistic transfer factors for the radionuclides 90Sr, 137Cs, 60Co and 54Mn

International Nuclear Information System (INIS)

Steffens, W.; Fuehr, F.; Mittelstaedt, W.

1980-01-01

Transfer factors for the root uptake of 90 Sr, 137 Cs, 60 Co and 54 Mn were compared using outdoor lysimeters, Kick-Brauckmann experimental pots under greenhouse conditions and Neubauer cups under growth chamber conditions. The uptake was studied in barley, potatoes, sugar beet and salad vegetables grown on either podsolic or loess soil. The transfer factors for these radionuclides under the specific conditions of the small scale Neubauer cup experiments differed greatly from those obtained from the outdoor lysimeter. In the pot experiments, the transfer factors for 90 Sr, 137 Cs and 54 Mn showed less deviation from the lysimeter results especially in crops grown on podsolic soil. For 60 Co, the transfer factors varied for the different crops grown. Transfer factors obtained in pot experiments can only be applicable to a limited extent to field conditions; factors influencing the transfer factors in pot experiments include soil volume, root density, root/shoot ratio, water supply and fertilizer application rate. (UK)

Migration studies at the Savannah River Plant shallow land burial site

International Nuclear Information System (INIS)

Stone, J.A.; Oblath, S.B.; Hawkins, R.H.; Emslie, R.H.; Ryan, J.P. Jr.; King, C.M.

1983-01-01

Radionuclide migration from the Savannah River Plant low-level waste burial ground was studied in ongoing programs that provide generic data on a shallow land burial site in a humid region and support local waste disposal operations. Field, laboratory, and theoretical work continued in four areas. (1) Subsurface Monitoring: Groundwater around the burial ground was monitored for traces of radioactivity and mercury. (2) Lysimeter Tests: Gamma-emitting radionuclides were identified by sensitive methods in defense waste lysimeter percolate waters. Results from these and other lysimeters containing tritium, I-129, or Pu-239 sources are given. (3) Soil-Water Chemistry: Experiments on specific factors affecting migration of Cs-137 showed that potassium significantly increases cesium mobility, thus confirming observations with trench waters. Distribution coefficients for ruthenium were measured. (4) Transport Modeling: Efforts to refine and validate the SRL dose-to-man model continued. Transport calculations were made for tritium, Sr-90, Tc-99, and TRU radionuclides. 12 references, 3 tables

Investigation of magnetic drift on transport of plasma across magnetic field

International Nuclear Information System (INIS)

Hazarika, Parismita; Chakraborty, Monojit; Das, Bidyut; Bandyopadhyay, Mainak

2015-01-01

When a metallic body is inserted inside plasma chamber it is always associated with sheath which depends on plasma and wall condition. The effect of sheath formed in the magnetic drift and magnetic field direction on cross field plasma transport has been investigated in a double Plasma device (DPD). The drifts exist inside the chamber in the transverse magnetic field (TMF) region in a direction perpendicular to both magnetic field direction and axis of the DPD chamber. The sheath are formed in the magnetic drift direction in the experimental chamber is due to the insertion of two metallic plates in these directions and in the magnetic field direction sheath is formed at the surface of the TMF channels. These metallic plates are inserted in order to obstruct the magnetic drift so that we can minimised the loss of plasma along drift direction and density in the target region is expected to increase due to the obstruction. It ultimately improves the negative ion formation parameters. The formation of sheath in the transverse magnetic field region is studied by applying electric field both parallel and antiparallel to drift direction. Data are acquired by Langmuir probe in source and target region of our chamber. (author)

Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

Energy Technology Data Exchange (ETDEWEB)

Hedenstroem, Anna [SGU, Uppsala (Sweden)

2003-04-01

The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003.

Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

International Nuclear Information System (INIS)

Hedenstroem, Anna

2003-04-01

The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003

Investigations of radial electric field and global circulation layer in limiter tokamaks

International Nuclear Information System (INIS)

Zagorski, R.; Gerhauser, H.; Lehnen, M.; Loarer, T.

2002-01-01

An updated version of the 2D multifluid code TECXY is used to study the radial electric field structure and the appearance of a global circulation layer (GCL) inside the separatrix of the limiter tokamaks TEXTOR-94 and Tore-Supra-CIEL. The dependence of the driving forces on device geometry, limiter position, magnetic field orientation, impurity content and other parameters is investigated. The centrifugal force in the vicinity of the limiter head always determines the direction of the poloidal velocity in the GCL. There is good agreement with experimentally measured profiles of the poloidal velocity at the TEXTOR low field side. (orig.)

Methane production from food waste leachate in laboratory-scale simulated landfill.

Science.gov (United States)

Behera, Shishir Kumar; Park, Jun Mo; Kim, Kyeong Ho; Park, Hung-Suck

2010-01-01

Due to the prohibition of food waste landfilling in Korea from 2005 and the subsequent ban on the marine disposal of organic sludge, including leachate generated from food waste recycling facilities from 2012, it is urgent to develop an innovative and sustainable disposal strategy that is eco-friendly, yet economically beneficial. In this study, methane production from food waste leachate (FWL) in landfill sites with landfill gas recovery facilities was evaluated in simulated landfill reactors (lysimeters) for a period of 90 d with four different inoculum-substrate ratios (ISRs) on volatile solid (VS) basis. Simultaneous biochemical methane potential batch experiments were also conducted at the same ISRs for 30 d to compare CH(4) yield obtained from lysimeter studies. Under the experimental conditions, a maximum CH(4) yield of 0.272 and 0.294 L/g VS was obtained in the batch and lysimeter studies, respectively, at ISR of 1:1. The biodegradability of FWL in batch and lysimeter experiments at ISR of 1:1 was 64% and 69%, respectively. The calculated data using the modified Gompertz equation for the cumulative CH(4) production showed good agreement with the experimental result obtained from lysimeter study. Based on the results obtained from this study, field-scale pilot test is required to re-evaluate the existing sanitary landfills with efficient leachate collection and gas recovery facilities as engineered bioreactors to treat non-hazardous liquid organic wastes for energy recovery with optimum utilization of facilities. 2010 Elsevier Ltd. All rights reserved.

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.

Performance of Evapotranspirative Covers Under Enhanced Precipitation: Preliminary Data

International Nuclear Information System (INIS)

David C. Anderson; Lloyd T. Desotell; David B. Hudson; Gregory J. Shott; Vefa Yucel

2007-01-01

Since January 2001, drainage lysimeter studies have been conducted at Yucca Flat, on the Nevada Test Site, in support of an evapotranspirative cover design. Yucca Flat has an arid climate with average precipitation of 16.5 cm annually. The facility consists of six drainage lysimeters 3 m in diameter, 2.4 m deep, and backfilled with a single layer of native soil. The bottom of each lysimeter is sealed and equipped with a small drain that enables direct measurement of saturated drainage. Each lysimeter has eight time-domain reflectometer probes to measure moisture content-depth profiles paired with eight heat-dissipation probes to measure soil-water potential depth profiles. Sensors are connected to dataloggers which are remotely accessed via a phone line. The six lysimeters have three different surface treatments: two are bare-soil; two were revegetated with native species (primarily shadscale, winterfat, ephedra, and Indian rice grass); and two were allowed to revegetate naturally with such species as Russian thistle, halogeton, tumblemustard and cheatgrass. Beginning in October 2003, one half of the paired cover treatments (one bare soil, one invader species, and one native species) were irrigated with an amount of water equal to two times the natural precipitation to achieve a three times natural precipitation treatment. From October 2003 through December 2005, all lysimeters received 52.8 cm precipitation, and the four irrigated lysimeters received an extra 105.6 cm of irrigation. No drainage has occurred from any of the nonirrigated lysimeters, but moisture has accumulated at the bottom of the bare-soil lysimeter and the native-plant lysimeter. All irrigated lysimeters had some drainage. The irrigated baresoil lysimeter had 48.3 cm of drainage or 26.4 percent of the combined precipitation and applied irrigation for the entire monitoring record. The irrigated invader species lysimeter had 5.8 cm of drainage, about 3.2 percent of the combined precipitation and

Steering Electromagnetic Fields in MRI: Investigating Radiofrequency Field Interactions with Endogenous and External Dielectric Materials for Improved Coil Performance at High Field

Science.gov (United States)

Vaidya, Manushka

Although 1.5 and 3 Tesla (T) magnetic resonance (MR) systems remain the clinical standard, the number of 7 T MR systems has increased over the past decade because of the promise of higher signal-to-noise ratio (SNR), which can translate to images with higher resolution, improved image quality and faster acquisition times. However, there are a number of technical challenges that have prevented exploiting the full potential of ultra-high field (≥ 7 T) MR imaging (MRI), such as the inhomogeneous distribution of the radiofrequency (RF) electromagnetic field and specific energy absorption rate (SAR), which can compromise image quality and patient safety. To better understand the origin of these issues, we first investigated the dependence of the spatial distribution of the magnetic field associated with a surface RF coil on the operating frequency and electrical properties of the sample. Our results demonstrated that the asymmetries between the transmit (B1+) and receive (B 1-) circularly polarized components of the magnetic field, which are in part responsible for RF inhomogeneity, depend on the electric conductivity of the sample. On the other hand, when sample conductivity is low, a high relative permittivity can result in an inhomogeneous RF field distribution, due to significant constructive and destructive interference patterns between forward and reflected propagating magnetic field within the sample. We then investigated the use of high permittivity materials (HPMs) as a method to alter the field distribution and improve transmit and receive coil performance in MRI. We showed that HPM placed at a distance from an RF loop coil can passively shape the field within the sample. Our results showed improvement in transmit and receive sensitivity overlap, extension of coil field-of-view, and enhancement in transmit/receive efficiency. We demonstrated the utility of this concept by employing HPM to improve performance of an existing commercial head coil for the

Investigation of Nursery Rhymes According to the Classification of Semantic Fields and Values

Science.gov (United States)

Dinçel, Betül Keray

2017-01-01

Nursery rhymes are quite important in terms of developing children's language skills. It was observed that there is a paucity of research looking at semantic fields and value regarding nursery rhymes; therefore, this study was intended to fill that gap in the literature by investigating nursery rhymes in terms of semantic fields and value. In this…

Control of water infiltration into near surface low-level waste disposal units. Final report on field experiments at a humid region site, Beltsville, Maryland

International Nuclear Information System (INIS)

Schulz, R.K.; Ridky, R.W.; O'Donnell, E.

1997-09-01

This study''s objective was to assess means for controlling water infiltration through waste disposal unit covers in humid regions. Experimental work was carried out in large-scale lysimeters 21.34 m x 13.72 m x 3.05 m (70 ft x 45 ft x 10 ft) at Beltsville, Maryland. Results of the assessment are applicable to disposal of low-level radioactive waste (LLW), uranium mill tailings, hazardous waste, and sanitary landfills. Three kinds of waste disposal unit covers or barriers to water infiltration were investigated: (1) resistive layer barrier, (2) conductive layer barrier, and (3) bioengineering management

Optical investigation of effective permeability of dilute magnetic dielectrics with magnetic field

Science.gov (United States)

Banerjee, Ananya; Sarkar, A.

2016-05-01

The prime objective of this paper is to investigate the magnetic nature of dilute magnetic dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano-sized Gadolinium Oxide as a DMD system. The observed experimental field variation of the effective magnetic permeability is analyzed results of optical experiment. The experiment records the variation of Brewster angle of incident polarized LASER beam from the surface of developed DMD specimen with applied out of plane external magnetic field. The effective refractive index and hence relative magnetic permeability were estimated following electro-magnetic theory. The overall results obtained and agreement between theory and experiment are good.

Investigation of different magnetic field configurations using an electrical, modular Zeeman slower

Energy Technology Data Exchange (ETDEWEB)

Ohayon, Ben; Ron, Guy, E-mail: gron@racah.phys.huji.ac.il [Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

2015-10-15

We present a method of constructing an automatically reconfigurable, modular, electronic Zeeman slower, which is remotely controlled. This setup is used to investigate the ability of different magnetic field profiles to slow thermal atoms to the capture velocity of a magneto-optical-trap. We show that a simple numerical optimization process yields better results than the commonly used approach for deciding on the appropriate field and comes close to the optimum field, found by utilizing a fast feedback loop which uses a genetic algorithm. Our new numerical method is easily adaptable to a variety of existing slower designs and may be beneficial where feedback is unavailable.

Optical investigation of effective permeability of dilute magnetic dielectrics with magnetic field

Energy Technology Data Exchange (ETDEWEB)

Banerjee, Ananya, E-mail: banerjee.ananya2008@gmail.com; Sarkar, A. [Dept. of Physics, Bijoy Krishna Girls’ College, 5/3 M.G. Road, Howrah 711101, W.B. (India)

2016-05-06

The prime objective of this paper is to investigate the magnetic nature of dilute magnetic dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano-sized Gadolinium Oxide as a DMD system. The observed experimental field variation of the effective magnetic permeability is analyzed results of optical experiment. The experiment records the variation of Brewster angle of incident polarized LASER beam from the surface of developed DMD specimen with applied out of plane external magnetic field. The effective refractive index and hence relative magnetic permeability were estimated following electro-magnetic theory. The overall results obtained and agreement between theory and experiment are good.

Estimation of water percolation by different methods using TDR

Directory of Open Access Journals (Sweden)

Alisson Jadavi Pereira da Silva

2014-02-01

Full Text Available Detailed knowledge on water percolation into the soil in irrigated areas is fundamental for solving problems of drainage, pollution and the recharge of underground aquifers. The aim of this study was to evaluate the percolation estimated by time-domain-reflectometry (TDR in a drainage lysimeter. We used Darcy's law with K(θ functions determined by field and laboratory methods and by the change in water storage in the soil profile at 16 points of moisture measurement at different time intervals. A sandy clay soil was saturated and covered with plastic sheet to prevent evaporation and an internal drainage trial in a drainage lysimeter was installed. The relationship between the observed and estimated percolation values was evaluated by linear regression analysis. The results suggest that percolation in the field or laboratory can be estimated based on continuous monitoring with TDR, and at short time intervals, of the variations in soil water storage. The precision and accuracy of this approach are similar to those of the lysimeter and it has advantages over the other evaluated methods, of which the most relevant are the possibility of estimating percolation in short time intervals and exemption from the predetermination of soil hydraulic properties such as water retention and hydraulic conductivity. The estimates obtained by the Darcy-Buckingham equation for percolation levels using function K(θ predicted by the method of Hillel et al. (1972 provided compatible water percolation estimates with those obtained in the lysimeter at time intervals greater than 1 h. The methods of Libardi et al. (1980, Sisson et al. (1980 and van Genuchten (1980 underestimated water percolation.

Migration of 226 Ra, 228 Ra, 210 Pb, U and Th from phosphogypsum

International Nuclear Information System (INIS)

Silva, Nivaldo Carlos da; Cipriani, Moacir; Taddei, Maria Helena T.

2002-01-01

The physico-chemical availability of radioactive elements ( 210 Pb, 226 Ra, 228 Ra, Th and U) in Brazilian phosphogypsum was investigated in a large scale leaching experiment carried out in lysimeters, using phosphogypsum samples (approximately 1.2 tons) from two phosphoric acid industries. Lysimeters were built using cylindrical concrete containers with 0.9 m inner diameter and 2 m depth. The bottom of the lysimeter was filled with a 10 cm layer of gravel covered with geomembrane sheet. Under this layer a pipe was designed to drain the percolated water. Three lysimeters were filled with phosphogypsum from each industry and a mixture of both. As percolated water comes exclusively from the rain, sample was collected daily when available. Samples were then pooled weekly, carefully prepared and submitted to radiochemical analysis. Radiochemical characterization of phosphogypsum and percolated water was performed by radiochemical separation followed by gross alpha and beta counting ( 226 Ra, 228 Ra and 210 Pb) and UV-Vis spectrophotometry with Arsenazo III (U and Th). This experiment was carried out from 12/01/1999 to 01/22/2001, with a precipitation of 2,732 mm. It was observed that approximately 40% (534 L) of the rain fall percolated through the lysimeter 1. The analysis of 22 samples of percolated water from lysimeter 1 showed mean radionuclides activities of 70±30 mBqL -1 , 70±50 mBqL -1 , 100±60 mBqL -1 and 110±55 mBqL -1 for U, 226 Ra, 228 Ra and 210 Pb, respectively. Thorium activities were below detection limit. (author)

High field Moessbauer and magnetic investigations of Pr0.73Fe4Sb12

International Nuclear Information System (INIS)

Reissner, Michael; Bauer, Ernst; Steiner, Walter; Rogl, Peter

2004-01-01

In accordance with the filling factor determined by X-ray investigations two Fe sites were identified in the in-field 57 Fe Moessbauer spectra. The derived internal fields at 4.2 K were small (0.35 and 1.45 T at external fields of 13.5 T), whereas from magnetic measurements μ eff ∼2.7 μ B was estimated for the Fe 4 Sb 12 -sublattice

Investigation of Radiation Fields at Aircraft Altitudes (invited paper)

International Nuclear Information System (INIS)

O'Sullivan, D.; Bartlett, D.; Grillmaier, R.; Heinrich, W.; Lindborg, L.; Schraube, H.; Silari, M.; Tommasino, L.; Zhou, D.

2000-01-01

Cosmic rays are believed to originate from several possible sources and recent research suggests that the bulk originate from the gas and dust of the interstellar medium and are accelerated by strong shock waves driven by supernova explosions. Cosmic ray particles are made up of γ98.5% hydrogen and helium and only 1.5% have charges greater than 2. Their average energy is about 1 GeV/nucleon and they lose energy through ionisation interactions and nuclear interactions with atoms of air as they penetrate deeply into the Earth's atmosphere. A very complicated radiation field develops as particles are generated by successive interaction of primary and secondary nuclei and a cascade of hadrons is produced in the atmosphere. The intensity of particles reaches a maximum at about 20 km above sea level (γ60 g.cm -2 ). The relative abundances of different particles change with depth within the atmosphere and mainly muons which are the decay products of charged mesons, reach sea level because of their weak interaction. The radiation field produced and consequently its effect on aircrew and frequent travellers is a matter of some concern. This paper outlines the results of investigations carried out to determine the characteristics of this radiation field and assess its impact on aircrew. (author)

Current status of investigations in the field of solid state science in central Kazakstan region

International Nuclear Information System (INIS)

Kuketaev, T.A.

1999-01-01

Investigations in the field of solid state science were initiated together with foundation of University in Karaganda. Historically general investigations in this field were conducted for scientific directions related to optical, luminescent and radiation properties of wide gap insulator. This activity was carried out according to appropriate plans of coordination counsels en-gaged in the physics of insulators, luminescent and radiation physics at the Academy of Science USSR and in the Committee on sciences and engineering of the Counsel of Ministers of the USSR. A number of works were coordinated by the Academy of Sciences of Kazakhstan Republic. Investigations in the field of solid state science, con-ducted in the Central Kazakstan and coordinated by the Institute of Physics and Engineering of Kazakhstan National Academy of Sciences, can be currently distinguished according to scientific directions. Currently, the following scientific directions in the field of solid state science exist in the Central Kazakstan: influence of polymorph phase transitions on electron excitation in wide-gap crystals, radiation malformation and recombination, dielectric spectroscopy of crystals with hydrogen link, spectral and luminescent properties and energy migration processes in disordered and partly ordered systems of organic molecules. It is necessary to note that all investigated objects, described in this report, were recovered by investigators. That is, the relevant hardware is available

Investigating Unsaturated Zone Travel Times with Tritium and Stable Isotopes

Science.gov (United States)

Visser, A.; Thaw, M.; Van der Velde, Y.

2017-12-01

Travel times in the unsaturated zone are notoriously difficult to assess. Travel time tracers relying on the conservative transport of dissolved (noble) gases (tritium-helium, CFCs or SF6) are not applicable. Large water volume requirements of other cosmogenic radioactive isotopes (sulfur-35, sodium-22) preclude application in the unsaturated zone. Prior investigations have relied on models, introduced tracers, profiles of stable isotopes or tritium, or a combination of these techniques. Significant unsaturated zone travel times (UZTT) complicate the interpretation of stream water travel time tracers by ranked StorAge Selection (rSAS) functions. Close examination of rSAS functions in a sloping soil lysimeter[1] show the effect of the UZTT on the shape of the rSAS cumulative distribution function. We studied the UZTT at the Southern Sierra Critical Zone Observatory (SS-CZO) using profiles of tritium and stable isotopes (18O and 2H) in the unsaturated zone, supported by soil water content data. Tritium analyses require 100-500 mL of soil water and therefore large soil samples (1-5L), and elaborate laboratory procedures (oven drying, degassing and noble gas mass spectrometry). The high seasonal and interannual variability in precipitation of the Mediterranean climate, variable snow pack and high annual ET/P ratios lead to a dynamic hydrology in the deep unsaturated soils and regolith and highly variable travel time distributions. Variability of the tritium concentration in precipitation further complicates direct age estimates. Observed tritium profiles (>3 m deep) are interpreted in terms of advective and dispersive vertical transport of the input variability and radioactive decay of tritium. Significant unsaturated zone travel times corroborate previously observed low activities of short-lived cosmogenic radioactive nuclides in stream water. Under these conditions, incorporating the UZTT is critical to adequately reconstruct stream water travel time distributions. 1

The magnetic field investigation on the ARASE (ERG) mission: Data characteristics and initial scientific results

Science.gov (United States)

Matsuoka, A.; Teramoto, M.; Nomura, R.; Nose, M.; Fujimoto, A.; Tanaka, Y.; Shinohara, M.; Nagatsuma, T.; Shiokawa, K.; Obana, Y.; Miyoshi, Y.; Takashima, T.; Shinohara, I.

2017-12-01

The ARASE (ERG) satellite was successfully launched on December 20 2016. A fluxgate magnetometer (MGF) was built for the ARASE satellite to measure DC and low-frequency magnetic field. The requirements to the magnetic field measurements by ARASE was defined as (1) accuracy of the absolute field intensity is within 5 nT (2) angular accuracy of the field direction is within 1 degree (3) measurement frequency range is from DC to 60Hz or wider. MGF measures the vector magnetic field with the original sampling frequency of 256 Hz. The dynamic range is switched between +/-8000nT and +/- 60000nT according to the background field intensity. The MGF initial checkout was carried on January 10th 2017, when the MGF normal performance and downlinked data were confirmed. The 5-m length MAST for the sensor was deployed on 17th January. The nominal operation of MGF started in March 2017. The MGF data are calibrated based on the results from the ground experiments and in-orbit data analysis. The MGF CDF files are distributed by the ARASE Science Center and available by Space Physics Environment Data Analysis Software (SPEDAS). The acceleration process of the charged particles in the inner magnetosphere is considered to be closely related to the deformation and perturbation of the magnetic field. Accurate measurement of the magnetic field is required to understand the acceleration mechanism of the charged particles, which is one of the major scientific objectives of the ARASE mission. We designed a fluxgate magnetometer which is optimized to investigate following topics; (1) accurate measurement of the background magnetic field - the deformation of the magnetic field and its relationship with the particle acceleration. (2) MHD waves - measurement of the ULF electromagnetic waves of frequencies about 1mHz (Pc4-5), and investigation of the radiation-belt electrons radially diffused by the resonance with the ULF waves. (3) EMIC waves - measurement of the electromagnetic ion

Investigation of the free electron laser with a guide magnetic field

International Nuclear Information System (INIS)

Kwan, T.; Dawson, J.M.

1979-01-01

The free electron laser with a static guide magnetic field has been investigated theoretically and by computer simulation using a fully relativistic electromagnetic particle code which has one spatial and three velocity dimensions. By passing a relativistic electron beam through a helical magnetic field, high frequency electromagnetic radiation is generated by its coupling to the negative energy electrostatic beam modes through the helical magnetic field. In the regime of strong guide field where Ω/sub c/e/γ>>k 0 v/sub 0z/, the dispersion relation is obtained by using a fluid model for the electron beam and the growth rates are solved for numerically. Reasonable agreement between the theory and the simulations has been obtained. It was found that the growth rate increases linearly with magnetic ripple strength but decreases with the strength of the guide field. In addition, the growth rates also increase slightly with the beam energy. For a reasonably strong guide field (e.g., Ω/sub c/e=6.0ω/sub p/e), the growth rate can be on the order of 0.1ω/sub p/e and the efficiency of radiation production has been found to be as high as 16%. However, the efficiency decreases with the strength of the guide field. A theory for the saturation level is developed which relates the efficiency to the continued growth of the electromagnetic wave after the onset of trapping by the electrostatic field. It is found that the growth continues for about one bounce time and the observed saturation levels are reasonably well explained

Investigations of dc breakdown fields

CERN Document Server

Ramsvik, Trond; Reginelli, Alessandra; Taborelli, Mauro

2006-01-01

The need for high accelerating gradients for the future 30 GHz multi-TeV e+e- Compact Linear Collider (CLIC) at CERN has triggered a comprehensive study of DC breakdown fields of metals in UHV. The study shows that molybdenum (Mo), tungsten (W), titanium (Ti) and TiVAl reach high breakdown fields, and are thus good candidates for the iris material of CLIC structures. A significant decrease in the saturated breakdown field (Esat) is observed for molybdenum and tungsten when exposed to air. Specifically, at air pressures of 10-5 mbar, the decrease in Esat is found to be 50% and 30% for molybdenum and tungsten, respectively. In addition, a 30% decrease is found when molybdenum is conditioned with a CO pressure of ~1-10-5 mbar. Surface analysis measurements and breakdown conditioning in O2 ambience imply that the origin of the decrease in Esat is closely linked to oxide formation on the cathode surface. "Ex-situ" treatments by ion bombardment of molybdenum effectively reduce the oxide layers, and improve the brea...

Experimental investigation of the velocity field in buoyant diffusion flames using PIV and TPIV algorithm

Science.gov (United States)

L. Sun; X. Zhou; S.M. Mahalingam; D.R. Weise

2005-01-01

We investigated a simultaneous temporally and spatially resolved 2-D velocity field above a burning circular pan of alcohol using particle image velocimetry (PIV). The results obtained from PIV were used to assess a thermal particle image velocimetry (TPIV) algorithm previously developed to approximate the velocity field using the temperature field, simultaneously...

FINESSE: Field Investigations to Enable Solar System Science and Exploration

Science.gov (United States)

Heldmann, Jennifer; Lim, Darlene; Colaprete, Anthony

2015-01-01

The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We follow the philosophy that "science enables exploration and exploration enables science." 1) FINESSE Science: Understand the effects of volcanism and impacts as dominant planetary processes on the Moon, NEAs, and Phobos & Deimos. 2) FINESSE Exploration: Understand which exploration concepts of operations (ConOps) and capabilities enable and enhance scientific return. To accomplish these objectives, we are conducting an integrated research program focused on scientifically-driven field exploration at Craters of the Moon National Monument and Preserve in Idaho and at the West Clearwater Lake Impact Structure in northern Canada. Field deployments aimed at reconnaissance geology and data acquisition were conducted in 2014 at Craters of the Moon National Monument and Preserve. Targets for data acquisition included selected sites at Kings Bowl eruptive fissure, lava field and blowout crater, Inferno Chasm vent and outflow channel, North Crater lava flow and Highway lava flow. Field investigation included (1) differential GPS (dGPS) measurements of lava flows, channels (and ejecta block at Kings Bowl); (2) LiDAR imaging of lava flow margins, surfaces and other selected features; (3) digital photographic documentation; (4) sampling for geochemical and petrographic analysis; (5) UAV aerial imagery of Kings Bowl and Inferno Chasm features; and (6) geologic assessment of targets and potential new targets. Over the course of the 5-week field FINESSE campaign to the West Clearwater Impact Structure (WCIS) in 2014, the team focused on several WCIS research topics, including impactites, central uplift formation, the impact-generated hydrothermal system, multichronometer

Investigation by perturbative and analytical method of electronic properties of square quantum well under electric field

Directory of Open Access Journals (Sweden)

Mustafa Kemal BAHAR

2010-06-01

Full Text Available In this study, the effects of applied electric field on the isolated square quantum well was investigated by analytic and perturbative method. The energy eigen values and wave functions in quantum well were found by perturbative method. Later, the electric field effects were investigated by analytic method, the results of perturbative and analytic method were compared. As well as both of results fit with each other, it was observed that externally applied electric field changed importantly electronic properties of the system.

Echoes from the Field: An Ethnographic Investigation of Outdoor Science Field Trips

Science.gov (United States)

Boxerman, Jonathan Zvi

As popular as field trips are, one might think they have been well-studied. Nonetheless, field trips have not been heavily studied, and little research has mapped what actually transpires during field trips. Accordingly, to address this research gap, I asked two related research questions. The first question is a descriptive one: What happens on field trips? The second question is explanatory: What field trip events are memorable and why? I employed design research and ethnographic methodologies to study learning in naturally occurring contexts. I collaborated with middle-school science teachers to design and implement more than a dozen field trips. The field trips were nested in particular biology and earth sciences focal units. Students were tasked with making scientific observations in the field and then analyzing this data during classroom activities. Audio and video recording devices captured what happened during the field trips, classroom activities and discussions, and the interviews. I conducted comparative microanalysis of videotaped interactions. I observed dozens of events during the field trips that reverberated across time and place. I characterize the features of these events and the objects that drew interest. Then, I trace the residue across contexts. This study suggests that field trips could be more than one-off experiences and have the potential to be resources to seed and enrich learning and to augment interest in the practice of science.

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...

Arsenic leaching and speciation in C&D debris landfills and the relationship with gypsum drywall content.

Science.gov (United States)

Zhang, Jianye; Kim, Hwidong; Dubey, Brajesh; Townsend, Timothy

2017-01-01

The effects of sulfide levels on arsenic leaching and speciation were investigated using leachate generated from laboratory-scale construction and demolition (C&D) debris landfills, which were simulated lysimeters containing various percentages of gypsum drywall. The drywall percentages in lysimeters were 0, 1, 6, and 12.4wt% (weight percent) respectively. With the exception of a control lysimeter that contained 12.4wt% of drywall, each lysimeter contained chromated copper arsenate (CCA) treated wood, which accounts for 10wt% of the C&D waste. During the period of study, lysimeters were mostly under anaerobic conditions. Leachate analysis results showed that sulfide levels increased as the percentage of drywall increased in landfills, but arsenic concentrations in leachate were not linearly correlated with sulfide levels. Instead, the arsenic concentrations decreased as sulfide increased up to approximately 1000μg/L, but had an increase with further increase in sulfide levels, forming a V-shape on the arsenic vs. sulfide plot. The analysis of arsenic speciation in leachate showed different species distribution as sulfide levels changed; the fraction of arsenite (As(III)) increased as the sulfide level increased, and thioarsenate anions (As(V)) were detected when the sulfide level further increased (>10 4 μg/L). The formation of insoluble arsenic sulfide minerals at a lower range of sulfide and soluble thioarsenic anionic species at a higher range of sulfide likely contributed to the decreasing and increasing trend of arsenic leaching. Copyright © 2016. Published by Elsevier Ltd.

Flow field investigations in rotating facilities by means of stationary PIV systems

International Nuclear Information System (INIS)

Armellini, A; Mucignat, C; Casarsa, L; Giannattasio, P

2012-01-01

The flow field inside rotating test sections can be investigated by means of particle image velocimetry (PIV) operated in the phase-locked mode. With this experimental approach, the measurement system is kept fixed and it is synchronized with the periodical passage of the test section. Therefore, the direct output of the PIV measurements is the absolute velocity field, while the relative one is indirectly obtained from proper data processing that relies on accurate knowledge of the peripheral velocity field. This work provides an uncertainty analysis about the evaluation of the peripheral displacement field in phase-locked PIV measurements. The analysis leads to the detection of the levels of accuracy required in the estimation of both the angular velocity and the position of the center of rotation to ensure correct evaluation of the peripheral displacement field. In this regard, a simple methodology is proposed to evaluate the center of rotation position with an accuracy below 1 px. Finally, a procedure to pre-process the PIV images by subtracting the peripheral displacement is described. The advantages of its implementation are highlighted by the comparison with the performance of a more standard methodology where the peripheral field is subtracted from the absolute velocity field and not directly from the PIV raw data

The Investigation of Field Plate Design in 500 V High Voltage NLDMOS

Directory of Open Access Journals (Sweden)

Donghua Liu

2015-01-01

Full Text Available This paper presents a 500 V high voltage NLDMOS with breakdown voltage (VBD improved by field plate technology. Effect of metal field plate (MFP and polysilicon field plate (PFP on breakdown voltage improvement of high voltage NLDMOS is studied. The coeffect of MFP and PFP on drain side has also been investigated. A 500 V NLDMOS is demonstrated with a 37 μm drift length and optimized MFP and PFP design. Finally the breakdown voltage 590 V and excellent on-resistance performance (Rsp = 7.88 ohm * mm2 are achieved.

Detailed Field Investigation of Vapor Intrusion Processes

Science.gov (United States)

2008-09-01

drinks are preferable to caffeinated beverages or soft drinks. Refrain from alcohol the night before field work. • While in the field drink...crude drug made from the plant Cannabis sativa. The main mind-altering (psychoactive) ingredient in marijuana is THC (delta-9-tetrahydrocannobinol... caffeinated beverages or soft drinks. Refrain from alcohol the night before field work. • In the field drink frequently. Numerous small drinks at a tepid

Field investigation of the drift shadow

International Nuclear Information System (INIS)

Su, Grace W.; Kneafsey, Timothy J.; Ghezzehei, Teamrat A.; Marshall, Brian D.; Cook, Paul J.

2005-01-01

A drift shadow is an area immediately beneath an underground void that, in theory, will be relatively drier than the surrounding rockmass. Numerical and analytical models of water flow through unsaturated rock predict the existence of a drift shadow, but field tests confirming its existence have yet to be performed. Proving the existence of drift shadows and understanding their hydrologic and transport characteristics could provide a better understanding of how contaminants move in the subsurface if released from waste emplacement drifts such as the proposed nuclear waste repository at Yucca Mountain, Nevada. We describe the field program that will be used to investigate the existence of a drift shadow and the corresponding hydrological process at the Hazel-Atlas silica-sandmine located at the Black Diamond Mines Regional Preserve in Antioch, California. The location and configuration of this mine makes it an excellent site to observe and measure drift shadow characteristics. The mine is located in a porous sandstone unit of the Domengine Formation, an approximately 230 meter thick series of interbedded Eocene-age shales, coals, and massive-bedded sandstones. The mining method used at the mine required the development of two parallel drifts, one above the other, driven along the strike of the mined sandstone stratum. This configuration provides the opportunity to introduce water into the rockmass in the upper drift and to observe and measure its flow around the underlying drift. The passive and active hydrologic tests to be performed are described. In the passive method, cores will be obtained in a radial pattern around a drift and will be sectioned and analyzed for in-situ water content and chemical constituents. With the active hydrologic test, water will be introduced into the upper drift of the two parallel drifts and the flow of the water will be tracked as it passes near the bottom drift. Tensiometers, electrical resistance probes, neutron probes, and ground

The erosion of carbonate stone by acid rain: Laboratory and field investigations

International Nuclear Information System (INIS)

Baedecker, P.A.; Reddy, M.M.

1993-01-01

This paper describes a laboratory experiment on the effects of acidic deposition on carbonate stone erosion. It can serve as the basis for an undergraduate (or pre college) experiment in environmental chemistry. Recent field investigations are described that provide measurements of carbonate stone dissolution and mechanical erosion under weathering conditions that are prevalent in the eastern US. The purpose of the laboratory work is to answer questions concerning the effects of hydrogen ion deposition on stone erosion processes that were difficult to resolve on the basis of field experiments alone

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

Investigating heterogeneous nucleation in peritectic materials via the phase-field method

International Nuclear Information System (INIS)

Emmerich, Heike; Siquieri, Ricardo

2006-01-01

Here we propose a phase-field approach to investigate the influence of convection on peritectic growth as well as the heterogeneous nucleation kinetics of peritectic systems. For this purpose we derive a phase-field model for peritectic growth taking into account fluid flow in the melt, which is convergent to the underlying sharp interface problem in the thin interface limit (Karma and Rappel 1996 Phys. Rev. E 53 R3017). Moreover, we employ our new phase-field model to study the heterogeneous nucleation kinetics of peritectic material systems. Our approach is based on a similar approach towards homogeneous nucleation in Granasy et al (2003 Interface and Transport Dynamics (Springer Lecture Notes in Computational Science and Engineering vol 32) ed Emmerich et al (Berlin: Springer) p 190). We applied our model successfully to extend the nucleation rate predicted by classical nucleation theory for an additional morphological term relevant for peritectic growth. Further applications to understand the mechanisms and consequences of heterogeneous nucleation kinetics in more detail are discussed

Field investigation of keyblock stability

International Nuclear Information System (INIS)

Yow, J.L. Jr.

1985-04-01

Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. This engineering problem is divided into two parts: block identification, and evaluation of block stability. One stable keyblock and thirteen fallen keyblocks were observed in field investigations at the Nevada Test Site. Nine blocks were measured in detail sufficient to allow back-analysis of their stability. Measurements included block geometry, and discontinuity roughness and compressive strength. Back-analysis correctly predicted stability or failure in all but two cases. These two exceptions involved situations that violated the stress assumptions of the stability calculations. Keyblock faces correlated well with known joint set orientations. The effect of tunnel orientation on keyblock frequency was apparent. Back-analysis of physical models successfully predicted block pullout force for two-dimensional models of unit thickness. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were examined. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls block displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender. Rock mass temperature decreases reduce the confining stress magnitudes and can lead to failure. The pattern of stresses affecting each block face explains conceptually the occurrence of pyramidal keyblocks that are truncated near their apex

Investigations of CuFeS{sub 2} semiconductor mineral from ocean rift hydrothermal vent fields by Cu NMR in a local field

Energy Technology Data Exchange (ETDEWEB)

Matukhin, V. L.; Pogoreltsev, A. I.; Gavrilenko, A. N., E-mail: ang-2000@mail.ru; Garkavyi, S. O.; Shmidt, E. V. [Kazan State Power University (Russian Federation); Babaeva, S. F. [All-Russia Research Institute of Geology and Mineral Resources of the World Ocean “VNIIOkeangeologiya” (Russian Federation); Sukhanova, A. A. [Saint-Petersburg Mining University (Russian Federation); Terukov, E. I. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2017-01-15

The results of investigating natural samples of chalcopyrite mineral CuFeS{sub 2} from massive oceanic sulfide ores of the Mid-Atlantic ridge by the {sup 63}Cu nuclear magnetic resonance (NMR {sup 63}Cu) in a local field at room temperature are presented. The significant width of the resonance lines found in the {sup 63}Cu NMR spectrum directly testifies to a wide distribution of local magnetic and electric fields in the investigated chalcopyrite samples. This distribution can be the consequence of an appreciable deviation of the structure of the investigated chalcopyrite samples from the stoichiometric one. The obtained results show that the pulsed {sup 63}Cu NMR can be an efficient method for studying the physical properties of deep-water polymetallic sulfides of the World Ocean.

Investigation on magnetic field dependent modulus of epoxidized natural rubber based magnetorheological elastomer

International Nuclear Information System (INIS)

Yunus, N. A.; Mazlan, S. A.; Ubaidillah; Aziz, S. A. A.; Khairi, M. H. Ahmad; Wahab, N. A. A.; Shilan, S. T.

2016-01-01

This paper presents an investigation on the use of epoxidized natural rubber (ENR) as a matrix of magnetorheological elastomers (MREs). Isotropic ENR-based MRE samples were synthesized by homogeneously mixed the ENR compound with carbonyl iron particles (CIPs). The microstructure of the sample was observed, and the magnetic field-dependent moduli were analyzed using rheometer. The influences of excitation frequency, CIPs content and magnetic field on the field-dependent moduli of ENR-based MREs were evaluated through dynamic shear test. The microstructure of MRE samples demonstrated the dispersed CIPs in the ENR matrix. The remarkable increment of storage and loss moduli of the ENR-based MREs has exhibited the magnetically controllable storage and loss moduli of the samples when exposed to the magnetic field. Consequently, the CIPs content, frequency and magnetic field were significantly influenced the dynamic moduli of the ENR-based MREs. (paper)

Theoretical and practical investigation of the electromagnetic radiation fields from the Sabborah radio broadcasting station

International Nuclear Information System (INIS)

Kharita, M. H.; Abo Kasem, I.; Kattab, A.

2008-01-01

This work has special importance as it aims at the investigation of the electromagnetic radiation from the Sabborah radio broadcasting station. The report includes general introduction to the physics of the electromagnetic fields and the biological effects of these fields and consequently its health effects. The bases of the recommended exposure limits according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) have been discussed in addition to the theoretical and practical investigations. This report summarizes the results of this study and the final recommendations. (author)

Control of water infiltration through SLB trench covers

International Nuclear Information System (INIS)

Schulz, R.K.; Ridky, R.W.

1986-01-01

A technique for control of water infiltration into waste burial trenches is described. Initial results show the procedure to be very promising. In essence, the technique combines engineered or positive control of run-off, along with a vegetative cover, and is named bioengineering management. To investigate control of infiltration, lysimeters are being used to make complete water balance measurements. The studies are underway at the Maxey Flats, Kentucky, low-level waste burial site. Where the original Maxey Flats site closure procedure is followed, it is necessary to pump large amounts of water out of the lysimeters to prevent the water table from rising closer than 2 meters from the surface. Using the fescue grass bioengineering management procedure, no pumping is required. Encouraged by the initial findings in the rather small-scale lysimeters, a large scale demonstration of the bioengineering management technique has been initiated in Beltsville, Maryland. 6 references, 14 figures

Investigation of an innovative technology for oil-field brine treatment

Energy Technology Data Exchange (ETDEWEB)

Miskovic, D; Dalmacija, B; Hain, Z; Karlovic, E; Maric, S; Uzelac, N [Inst. of Chemistry, Faculty of Sciences, V. Vlahovica 2 (YU)

1989-01-01

Various aspects of an innovative technology for oil field brine treatment were investigated on a laboratory scale. The both free and dispersed oily matter were separated by gravitation and sedimentation. Apart from the physico-chemical oil removal process, special attention was paid to different variants of improved microbiological treatment: dilution with fresh water and application of powdered activated carbon (PAC). Advanced treatment was carried out on granular biological activated carbon (GBAC). A technological scheme for complete treatment was proposed. (author).

Adjustment of nitrogen fertilization to the needs of plants and limitations posed by the risk of nitrate accumulation and pollution of the soil and subsoil

Energy Technology Data Exchange (ETDEWEB)

Muller, J C

1980-01-01

In chalky Champagne, nitrogen balance is study to adjust availability to plant response. For this, it is necessary to know some parameters whose measurement is obtained progressively; plants exportation, nitrogen transformations in terms of transport processes in soil system, kinetic of mineralization of soil organic nitrogen, plants residus and agricultural waste waters. Lysimeters with rotation of Champagne (wheat, sugarbeet, potatoes...) are used to measure losses of nitrogen and follow transport of nitrates by mean of soil solution captors. Comparisons with field results, lysimeters results and laboratory experimentations are used to adjust an experimental model. Two examples show: 1) Nitrogen fertilizer requirement for wheat. 2) Possibility of maximum application for agricultural waste waters.

The development of permanent isolation surface barriers: Hanford Site, Richland, Washington, U.S.A

International Nuclear Information System (INIS)

Wing, N.R.; Gee, G.W.

1993-01-01

Permanent isolation surface barriers are being developed to isolate wastes disposed of in situ (in place) at the US Department of Energy's Hanford Site in Washington State (USA). The current focus of development efforts is to design barriers that will function in a semiarid to subhumid climate, Emit infiltration and percolation of water through the waste zone to near-zero amounts, be maintenance free, and last up to 1000 years or more. A series of field tests, experiments, and lysimeter studies have been conducted for several years. The results of tests to date confirm that the Hanford barrier concepts are valid for both present and wetter climatic conditions. The data collected also have provided the foundation for the design of a large prototype barrier to be constructed later in 1993. This paper presents the results of some of the field tests, experiments, and lysimeter studies

Evaluating evapotranspiration for six sites in Benton, Spokane, and Yakima counties, Washington, May 1990 to September 1992

Science.gov (United States)

Tomlinson, S.A.

1996-01-01

This report evaluates evapotranspiration for six sites in Benton, Spokane, and Yakima Counties, Washington. Three sites were located on the Arid Lands Ecology Reserve in Benton County: one at a full-canopy grassland in Snively Basin (Snively Basin site), one at a sparse-canopy grassland adjacent to two weighing lysimeters (grass lysimeter site), and one at a sagebrush grassland adjacent to two weighing lysimeters (sage lysimeter site). Two sites were located on the Turnbull National Wildlife Refuge in Spokane County: one at a full-canopy grassland in a meadow (Turnbull meadow site), the other a full-canopy grassland near a marsh (Turnbull marsh site). The last site was located in a sagebrush grassland in the Black Rock Valley in Yakima County (Black Rock Valley site). The periods of study at the six sites varied, ranging from 5 months at the Black Rock Valley site to more than 2 years at the Snively Basin, grass lysimeter, and sage lysimeter sites. The periods of study were May 1990 to September 1992 for the Snively Basin, grass lysimeter, and sage lysimeter sites; May 1991 to September 1992 for the Turnbull meadow site; May 1991 to April 1992 for the Turnbull marsh site; and March to September 1992 for the Black Rock Valley site. Evapotranspiration and energy-budget fluxes were estimated for the Snively Basin site, the Turnbull meadow site, and the Black Rock Valley site using the Bowen-ratio and Penman-Monteith methods. Daily evapotranspiration for the Snively Basin site was also estimated using a deep-percolation model for the Columbia Basin. The Bowen-ratio method and weighing lysimeters were used at the grass and sage lysimeter sites. The Penman-Monteith method was used at the Turnbull marsh site. Daily evapotranspiration at the sites ranged from under 0.2 millimeter during very dry or cold periods to over 4\\x11millimeters after heavy rainfall or during periods of peak transpiration. At all sites, peak evapotranspiration occurred in spring, coinciding with

Investigation of local fields in different barium ferrite sublattices by means of nuclear magnetic resonance

International Nuclear Information System (INIS)

Utrecht, R.; Hankiewicz, J.

1995-01-01

The local fields on 57 Fe nuclei in ferrite (BaFe 12 O 19 ) polycrystals have been investigated by means of spin echo amplitudes measurements at 4.2 and 77 K. The magnetic moment orientation and local field intensity have been determined for five different ferrite sublattices

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

Control of water infiltration into near surface LLW disposal units. Progress report on field experiments at a humid region site, Beltsville, Maryland: Volume 7

International Nuclear Information System (INIS)

Schulz, R.K.; Ridky, R.W.; O'Donnell, E.

1994-12-01

The project objective is to assess means for controlling waste infiltration through waste disposal unit covers in humid regions. Experimental work is being performed in large scale lysimeters (70 ft x 45 ft x 10 ft) at Beltsville, MD and results of the assessment are applicable to disposal of LLW, uranium mill tailings, hazardous waste, and sanitary landfills. Three concepts are under investigation: (1) resistive layer barrier, (2) conductive layer barrier, and bioengineering water management. The resistive layer barrier consists of compacted earth (clay). The conductive layer barrier is a special case of the capillary barrier and it requires a flow layer (e.g. fine sandy loam) over a capillary break. As long as unsaturated conditions are maintained water is conducted by the flow layer to below the waste. This barrier is most efficient at low flow rates and is thus best placed below a resistive layer barrier. Such a combination of the resistive layer over the conductive layer barrier promises to be highly effective provided there is no appreciable subsidence. Bioengineering water management is a surface cover that is designed to accommodate subsidence. It consists of impermeable panels which enhance run-off and limit infiltration. Vegetation is planted in narrow openings between panels to transpire water from below the panels. This system has successfully dewatered two lysimeters thus demonstrating that this procedure could be used for remedial action (drying out) existing water-logged disposal sites at low cost

An experimental investigation of the internal magnetic field topography of an operating Hall thruster

International Nuclear Information System (INIS)

Peterson, Peter Y.; Gallimore, Alec D.; Haas, James M.

2002-01-01

Magnetic field measurements were made in the discharge channel of the 5 kW-class P5 laboratory-model Hall thruster to investigate what effect the Hall current has on the static, applied magnetic field topography. The P5 was operated at 1.6 and 3.0 kW with a discharge voltage of 300 V. A miniature inductive loop probe (B-Dot probe) was employed to measure the radial magnetic field profile inside the discharge channel of the P5 with and without the plasma discharge. These measurements are accomplished with minimal disturbance to thruster operation with the High-speed Axial Reciprocating Probe system. The results of the B-Dot probe measurements indicate a change in the magnetic field topography from that of the vacuum field measurements. The measured magnetic field profiles are then examined to determine the possible nature and source of the difference between the vacuum and plasma magnetic field profiles

Sources of the Geomagnetic Field and the Modern Data That Enable Their Investigation

DEFF Research Database (Denmark)

Olsen, Nils; Hulot, Gauthier; Sabaka, Terence J.

2014-01-01

has a large and complicated magnetic field, a major part of which is produced by a self-sustaining dynamo operating in the fluid outer core. What is measured at or near the surface of the Earth, however, is the superposition of the core field and of additional fields caused by magnetized rocks......The geomagnetic field one can measure at the Earth’s surface or on board satellites is the sum of contributions from many different sources. These sources have different physical origins and can be found both below (in the form of electrical currents and magnetized material) and above (only...... in the form of electrical currents) the Earth’s surface. Each source happens to produce a contribution with rather specific spatio-temporal properties. This fortunate situation is what makes the identification and investigation of the contribution of each source possible, provided appropriate observational...

FIELD INVESTIGATION OF THE DRIFT SHADOW

International Nuclear Information System (INIS)

G.W. Su; T.J. Kneafsey

2006-01-01

A drift shadow is an area immediately beneath an underground void that, in theory, will be relatively drier than the surrounding rock mass. Numerical and analytical models of water flow through unsaturated rock predict the existence of a drift shadow, but field tests confirming the existence of the drift shadow have yet to be performed. Proving the existence of drift shadows and understanding their hydrologic and transport characteristics could provide a better understanding of how contaminants move in the subsurface if released from waste emplacement drifts such as the proposed nuclear waste repository at Yucca Mountain, Nevada. We describe the field program that will be used to investigate the existence of a drift shadow--and the corresponding hydrological process at the Hazel-Atlas silica-sand mine located at the Black Diamond Mines Regional Preserve in Antioch, California. The location and configuration of this mine makes it an excellent site to observe and measure drift shadow characteristics. The mine is located in a porous sandstone unit of the Domengine formation, an approximately 230 meter thick series of interbedded Eocene-age shales, coals, and massive-bedded sandstones. The mining method used at the mine required the development of two parallel drifts, one above the other, driven along the strike of the mined sandstone stratum. This configuration provides the opportunity to introduce water into the rock mass in the upper drift and to observe and measure its flow around the underlying drift. The passive and active hydrologic tests to be performed are described. In the passive method, cores will be obtained in a radial pattern around a drift and will be sectioned and analyzed for in-situ water content using a gravimetric technique, as well as analyzed for chemistry. With the active hydrologic test, water will be introduced into the upper drift of the two parallel drifts and the flow of the water will be tracked as it passes near the bottom drift

Traversing field of view and AR-PIV for mid-field wake vortex investigation in a towing tank

Science.gov (United States)

Scarano, F.; van Wijk, C.; Veldhuis, L. L. M.

2002-08-01

Wake vortex flow experiments are performed in a water tank where a 1:48 scaled model of a large transport aircraft A340-300 is towed at the speed of 3 and 5 ms-1 with values of the angle of attack α={2°, 4°, 8°}. Particle image velocimetry (PIV) measurements are performed in a plane perpendicular to the towing direction describing the streamwise component of the wake vorticity. The instantaneous field of view (I-FOV) is traversed vertically with an underwater moving-camera device tracking the vortex core during the downward motion. An adaptive resolution (AR) image-processing technique is introduced that enhances the PIV interrogation in terms of spatial resolution and accuracy. The main objectives of the investigation are to demonstrate the applicability of PIV diagnostics in wake vortex research with towing-tank facilities. The specific implementation of the traversing field-of-view (T-FOV) technique and the AR image processing are driven by the need to characterize the vortex wake global properties as well as the vortex decay phenomenon in the mid- and far-field. Relevant aerodynamic information is obtained in the mid-field where the time evolution of the vortex structure (core radius and tangential velocity) and of the overall vortex wake (vortex trajectory, descent velocity, circulation) are discussed.

Crop coefficient, yield response to water stress and water productivity of teff (Eragrostis tef (Zucc.)

NARCIS (Netherlands)

Araya, A.; Stroosnijder, L.; Girmay, G.; Keesstra, S.D.

2011-01-01

In the semi-arid region of Tigray, Northen Ethiopia a two season experiment was conducted to measure evapotranspiration, estimate yield response to water stress and derive the crop coefficient of teff using the single crop coefficient approach with simple, locally made lysimeters and field plots.

Part 1: Logging residues in piles - Needle loss and fuel quality. Part 2: Nitrogen leaching under piles of logging residues

International Nuclear Information System (INIS)

Lehtikangas, P.; Lundkvist, H.

1991-01-01

Part 1: Experimental piles were built in three geographical locations during May-Sept. 1989. Logging residues consisted of 95% spruce and 5% pine. Height of the piles varied between 80 and 230 cm. Needles were collected by placing drawers under 40 randomely chosen piles. The drawers were emptied every two weeks during the storage period. Natural needle loss was between 18 and 32% of the total amount of needles after the first two months of storage. At the end of the storage period, 24-42% of the needles had fallen down to the drawers. At the end of the experiment the total needle fall was 95-100% in the shaken piles. According to the results of this study piles smaller than 150 cm had the most effective needle fall. Piles should be placed on open places where the air and sun heat penetrate and dry them. Needles were the most sensitive fraction to variations in precipitation compared to the other components, such as branches. Piles usually dried quickly, but they also rewet easily. This was especially true in the smaller piles. The lowest moisture content was measured at the end of June. The ash content in needles varied between 4 and 8%. 16 refs., 15 figs. Part 2: Three field experiments were equipped with no-tension humus lysimeters. Pairs of lysimeters with the same humus/field layer vegetation material were placed in pairs, one under a pile of felling residues and another in the open clear felling. Leaching of nitrogen as well as pH and electric conductivity in the leachate was followed through sampling of the leachate at regular intervals. The results from the investigation show that: * the amount of leachate was higher in lysimeters in the open clear felling, * pH in the leachate was initially lower under piles of felling residues, * the amount of nitrogen leached was higher in the open clear felling. Thus, storing of felling residues in piles during the summer season did not cause any increase in nitrogen leaching, which had been considered to be a risk

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...

Investigation of TC and TSS Removal Efficiencies at Ahvaz West WTP Effluent Using the Land‒plant Treatment Process

Directory of Open Access Journals (Sweden)

Afshin Takdastan

2015-12-01

Full Text Available Although the conventional (primary and secondary treatment processes are known to remove up to 95–99% of some micro-organisms, they do not provide adequate treatment to make the effluent suitable for direct reuse, mainly due to the presence of high concentrations of pathogenic microorganisms. Obtaining reusable effluents, therefore, requires the use of processes that can be justified both technical and economic grounds. One such indigenous, low cost option is the land-plant process that can be used for advanced wastewater treatment. It is the objective of the present study to determine the efficiency of the local soil in Ahvaz and that of the vetiver plant in reducing the microbial load in the effluent from municipal wastewater treatment plants. A pilot study was thus carried out including three Lysimeters installed in West Ahvaz Wastewater Treatment Plant. Local soil was used in one Lysimeter, local soil with vetiver plant in the second one, and an artificial assortment of soil comprising local soil, silica sand (0.5-1mm, and sand (15-30mm in the third. In addition, the effluent from the secondary settling outlet at the WTP was transferred by pumping at the three filtration rates of 0.2, 0.6, and 1 ml/min into the system with three replications for each rate and samples were collected from both inlet and outlet flows. The average removal efficiencies of Total Suspended Solids (TSS and Total Coliform (TC in the effluent from the three Lysimeters with local soil with vetiver, local soil without vetiver, and artificial soil assortment for the filtration rate of 0.2 ml/min were: 67.75% and 99.7%, 58.33% and 99.6%, and 56.25% and 99.5%, respectively. For a filtration rate of 0.6 ml/min, these values were: 53.33% and 98.93%, 48.8 and 98.77%, and 47.68% and 98.64%. Finally, the values obtained for a filtration rate of 0.6 ml/min were: 50% and 93.96%, 46.42 and 91.34%, and 44/04% and 88/81%, respectively. The results from the study showed that the

Subsurface Investigations Program at the Radioactive Waste Management Complex of the Idaho National Engineering Laboratory: Annual progress report, FY-1987

International Nuclear Information System (INIS)

Laney, P.T.; Minkin, S.C.; Baca, R.G.; McElroy, D.L.; Hubbell, J.M.; Hull, L.C.; Russell, B.F.; Stormberg, G.J.; Pittman, J.T.

1988-04-01

The Subsurface Investigations Program is obtaining program objectives of a field calibration of a model to predict long-term radionuclide migration and measurement of the actual migration to date. Three deep boreholes were drilled at the Radioactive Waste Management Complex (RWMC) to collect sample material for evaluation of radionuclide content in the interbeds, to determine geologic and hydrologic characteristics of the sediments, and to provide monitoring sites for moisture movement in these sediments. Suction lysimeters and heat dissipation sensors were installed in two deep boreholes to collect moisture data. Data from the moisture sensing instruments installed at the RWMC continued to be collected during FY-1987. Because of the large volume of collected data, the RWMC Data Management System was developed and implemented to facilitate the storage, retrieval, and manipulation of the database. Work on the Computer Model Development task focused on a detailed review of previous vadose zone modeling studies at INEL, acquisition and installation of a suite of computer models for unsaturated flow and contaminant transport, and preliminary applications of computer models using site-specific data. Computer models installed on the INEL CRAY computer for modeling transport through the subsurface pathway include SEMTRA, FEMTRA, TRACR3D, MAGNUM, and CHAINT. In addition to the major computer models, eight other codes, referred to as support codes and models, have been acquired and implemented. 27 refs., 70 figs., 22 tabs

Problem-based learning through field investigation: Boosting questioning skill, biological literacy, and academic achievement

Science.gov (United States)

Suwono, Hadi; Wibowo, Agung

2018-01-01

Biology learning emphasizes problem-based learning as a learning strategy to develop students ability in identifying and solving problems in the surrounding environment. Problem identification skills are closely correlated with questioning skills. By holding this skill, students tend to deliver a procedural question instead of the descriptive one. Problem-based learning through field investigation is an instruction model which directly exposes the students to problems or phenomena that occur in the environment, and then the students design the field investigation activities to solve these problems. The purpose of this research was to describe the improvement of undergraduate biology students on questioning skills, biological literacy, and academic achievement through problem-based learning through field investigation (PBFI) compared with the lecture-based instruction (LBI). This research was a time series quasi-experimental design. The research was conducted on August - December 2015 and involved 26 undergraduate biology students at the State University of Malang on the Freshwater Ecology course. The data were collected during the learning with LBI and PBFI, in which questioning skills, biological literacy, and academic achievement were collected 3 times in each learning model. The data showed that the procedural correlative and causal types of questions are produced by the students to guide them in conducting investigations and problem-solving in PBFI. The biological literacy and academic achievement of the students at PBFI are significantly higher than those at LBI. The results show that PBFI increases the questioning skill, biological literacy, and the academic achievement of undergraduate biology students.

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

Modelling Water Flow through Paddy Soils under Alternate Wetting and Drying Irrigation Practice

Science.gov (United States)

Shekhar, S.; Mailapalli, D. R.; Das, B. S.; Raghuwanshi, N. S.

2017-12-01

Alternate wetting and drying (AWD) irrigation practice in paddy cultivation requires an optimum soil moisture stress (OSMS) level at which irrigation water savings can be maximized without compromising the yield reduction. Determining OSMS experimentally is challenging and only possible with appropriate modeling tools. In this study, field experiments on paddy were conducted in thirty non-weighing type lysimeters during dry seasons of 2016 and 2017. Ten plots were irrigated using continuous flooding (CF) and the rest were irrigated with AWD practice at 40mb and 75mb soil moisture stress levels. Depth of ponding and soil suction at 10, 40 and 70 cm from the soil surface were measured daily from all lysimeter plots. The measured field data were used in calibration and validation of Hydrus-1D model and simulated the water flow for both AWD and CF plots. The Hydrus-1D is being used to estimate OSMS for AWD practice and compared the seasonal irrigation water input and deep percolation losses with CF practice.

The Investigation of Screening of Chromoelectric and Chromomagnetic Fields in QGP in Noncovariant Gauges

International Nuclear Information System (INIS)

Veliev, E.S.

2004-01-01

According to Thermal Quantum Chromodynamics (TQCD) hadron matter may be exist in different phase states, in particular, in the form of quark-gluon plasma (QGP). The aim of the present work is to investigate the screening of chromoelectric and chromomagnetic fields in QGP in temporal gauge. In temporal gauge gluon propagator has the unphysical poles. Hence, in the gluon self energy diagram calculations the singularities appear. In order to remove these singularities we used Leibbrandt-Mandelstam prescription. We obtained that chromoelectric fields are screened, but chromomagnetic fields are not screened. In coordinate space, the screening of chromoelectric fields reduces the range of gauge interactions. In momentum space, it contributes to regulate the infrared behavior of the various n-point Green functions. Also, it is shown that the obtained results are gauge invariant

The field investigation on thermal comfort of tent in early autumn of Tianjin

Directory of Open Access Journals (Sweden)

Yang Hao

2016-01-01

Full Text Available In a university campus in Tianjin, four tents were set up to investigate the thermal environment and thermal comfort. Both the field investigation and questionnaires were adopted in this experiment. Two hundred people were investigated, and two hundred questionnaires were gotten. The results show that the thermal comfort zone of officers and soldiers is 24°C to 28°C in early fall, it is a wide range. There is a big error between the PMV index and the actual survey results, PMV calculation index is not accurate in tents environment. The results will have a significant effect on improving the thermal comfort of tents..

Isotope geochemistry of sulfur in forest soils and in new groundwater below forest soils

International Nuclear Information System (INIS)

Mayer, B.

1993-04-01

The isotope geochemistry of sulphur in aerobic forest soils and new groundwater below forest soils was investigated for the purpose of investigating the transport and transformation behaviour of sulfate in the water-unsaturated zone. The effects of hydrodynamic and biogeochemical processes on the development of seepage water sulfate isotopes between depositions and groundwater were investigated by means of laboratory experiments, profile studies, lysimeter experiments, and field studies in order to determine the sulphur conversion processes. Dissolved sulphur from precipitates, seepage water, creek water and groundwater, as well as sulphur extracted from soil samples, were precipitated in the form of BaSO 4 or AgS 2 , decomposed thermally into SO 2 or CO 2 , and the 34 S/ 32 S and 18 O/ 16 O isotope ratios were determined by mass spectrometry. (orig.) [de

Limited field investigation report for the 100-DR-1 Operable Unit

International Nuclear Information System (INIS)

1994-06-01

This limited field investigation (LFI) report summarizes the data collection and analysis activities conducted during the 100-DR-1 Source Operable Unite LFI and the associated qualitative risk assessment (QRA), and makes recommendations on the continued candidacy of high-priority sites for interim remedial measures (IRM). The results and recommendations presented in this report are generally independent of future land use scenarios. The 100-DR-1 Operable Unit is one of four operable units associated with the 100 D/DR Area at the Hanford Site. The 100-DR-1 Operable Unit encompasses approximately 1.5 km 2 (0.59 mi 2 ) and is located immediately adjacent to the Columbia River shoreline. In general, it contains waste facilities associated with the original plant facilities constructed to support D Reactor facilities, as well as cooling water retention basin systems for both D and DR Reactors. The 100-DR-1 LFI began the investigative phase of the remedial investigation for a select number of high-priority sites. The LFI was performed to provide additional data needed to support selection, design and implementation of IRM, if needed. The LFI included data compilation, nonintrusive investigations, intrusive investigations, summarization of 100 Area aggregate studies, and data evaluation

Investigations about the effects of magnetic fields on QGP in heavy ion collisions

Energy Technology Data Exchange (ETDEWEB)

Inghirami, Gabriele; Bleicher, Marcus [FIAS, Frankfurt am Main (Germany); Goethe Universitaet, Frankfurt am Main (Germany); Del Zanna, Luca [Universita degli Studi di Firenze, Firenze (Italy); Osservatorio Astrofisico di Arcetri - INAF, Firenze (Italy); INFN, Sezione di Firenze (Italy); Haddadi, Mohsen [Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Becattini, Francesco [Universita degli Studi di Firenze, Firenze (Italy); INFN, Sezione di Firenze (Italy); Beraudo, Andrea [INFN, Sezione di Torino (Italy); Rolando, Valentina [Universita degli Studi di Ferrara, Ferrara (Italy); INFN, Sezione di Ferrara (Italy)

2016-07-01

Numerical hydrodynamic simulations of heavy ion collisions are constantly refined through the addition of effects that may significantly improve the matching with experimental data, like viscosity or fluctuating initial conditions, but, so far, electromagnetic interactions have been almost completely neglected. However, recent lattice QCD computations and classical electrodynamics estimates both suggest that the magnetic fields produced immediately after the collisions between nuclei may live long enough and with a strength sufficient to produce measurable effects. We would like to present the results of some preliminary investigations about the influence on the properties of the medium due the presence of a strong magnetic field.

Simulation of Quinoa (Chenopodium Quinoa Willd.) response to soil salinity using the saltmed model

DEFF Research Database (Denmark)

Razzaghi, Fatemeh; Plauborg, Finn; Ahmadi, Seyed Hamid

Quinoa (Chenopodium quinoa Willd.) is a crop with high tolerance to salinity and drought and its response to varying soil moisture and salinity levels was studied in a field lysimeter experiment. Quinoa (cv. Titicaca) was irrigated with different concentrations of saline water (0, 10, 20, 30 and 40...

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

Experimental investigation of flow field in a laboratory-scale compressor

Directory of Open Access Journals (Sweden)

Hongwei Ma

2017-02-01

Full Text Available The inner flow environment of turbomachinery presents strong three-dimensional, rotational, and unsteady characteristics. Consequently, a deep understanding of these flow phenomena will be the prerequisite to establish a state-of-the-art design system of turbomachinery. Currently the development of more accurate turbulence models and CFD tools is in urgent need for a high-quality database for validation, especially the advanced CFD tools, such as large eddy simulation (LES. Under this circumstance, this paper presents a detailed experimental investigation on the 3D unsteady flow field inside a laboratory-scale isolated-rotor with multiple advanced measurement techniques, including traditional aerodynamic probes, hotwire probes, unsteady endwall static pressure measurement, and stereo particle image velocimetry (SPIV. The inlet boundary layer profile is measured with both hotwire probe and aerodynamic probe. The steady and unsteady flow fields at the outlet of the rotor are measured with a mini five-hole probe and a single-slanted hotwire probe. The instantaneous flow field in the rotor tip region inside the passage is captured with SPIV, and then a statistical analysis of the spatial distribution of the instantaneous tip leakage vortex/flow is performed to understand its dynamic characteristics. Besides these, the uncertainty analysis of each measurement technique is described. This database is quite sufficient to validate the advanced numerical simulation with LES. The identification process of the tip leakage vortex core in the instantaneous frames obtained from SPIV is performed deliberately. It is concluded that the ensemble-averaged flow field could not represent the tip leakage vortex strength and the trajectory trace. The development of the tip leakage vortex could be clearly cataloged into three phases according to their statistical spatial distribution. The streamwise velocity loss induced by the tip leakage flow increases until the

Photoelastic and analytical investigation of stress in toroidal magnetic field coils

International Nuclear Information System (INIS)

Pih, H.; Gray, W.H.

1975-01-01

A series of two-dimensional photoelastic stress analyses on circular and oval toroidal magnetic field coils for fusion reactors were made. The circumferential variation of the coil's magnetic force was simulated by applying different pressures to sixteen segmented regions of the inner surface of the models. Isochromatics and isoclinics were measured at selected points on the loaded model in a transmission polariscope using a microphotometer. Separate principal stresses were obtained using the combination of photoelastic information and isopachic data measured from the solution of Laplace's equation by the electrical analog method. Analysis of the same coil geometries, loadings, and boundary conditions were made using the finite element method. General agreement between theory and experiment was realized. From this investigation several variations of coil geometry and methods of support were evaluated. Based upon this experiment, suggestions for optimum structural design of toroidal field coils are presented

Investigation of the magnetic field of the permanent magnet applied in the DIRAC experiment

CERN Document Server

Batyuk, P; Yazkov, V

2012-01-01

An analysis of the experimental data obtained during the run of 2011 has revealed the effect of degradation of the permanent magnet used. This effect is investigated, and average magnetic field is estimated for each day of the run.

Research review: Functional brain connectivity and child psychopathology--overview and methodological considerations for investigators new to the field.

Science.gov (United States)

Matthews, Marguerite; Fair, Damien A

2015-04-01

Functional connectivity MRI is an emerging technique that can be used to investigate typical and atypical brain function in developing and aging populations. Despite some of the current confounds in the field of functional connectivity MRI, the translational potential of the technique available to investigators may eventually be used to improve diagnosis, early disease detection, and therapy monitoring. Based on a comprehensive survey of the literature, this review offers an introduction of resting-state functional connectivity for new investigators to the field of resting-state functional connectivity. We discuss a brief history of the technique, various methods of analysis, the relationship of functional networks to behavior, as well as the translational potential of functional connectivity MRI to investigate neuropsychiatric disorders. We also address some considerations and limitations with data analysis and interpretation. The information provided in this review should serve as a foundation for investigators new to the field of resting-state functional connectivity. The discussion provides a means to better understand functional connectivity and its application to typical and atypical brain function. © 2014 Association for Child and Adolescent Mental Health.

Crystal-field investigations of rare-earth-doped wide band gap semiconductors

CERN Multimedia

Muller, S; Wahl, U

Crystal field investigations play a central role in the studies of rare earth doped semiconductors. Optical stark level spectroscopy and lattice location studies of radioactive rare earth isotopes implanted at ISOLDE have provided important insight into these systems during the last years. It has been shown that despite a major site preference of the probe atoms in the lattice, several defect configurations do exist. These sites are visible in the optical spectra but their origin and nature aren't deducible from these spectra alone. Hyperfine measurements on the other hand should reveal these defect configurations and yield the parameters necessary for a description of the optical properties at the atomic scale. In order to study the crystal field with this alternative approach, we propose a new concept for perturbed $\\gamma\\gamma$-angular correlation (PAC) experiments at ISOLDE based on digital signal processing in contrast to earlier analog setups. The general functionality of the spectrometer is explained ...

Engaging High School Students in Investigative STEM Activities Based on Field Research

Science.gov (United States)

Stevens, J.; Sheriff, M. M.; Washington, D. S.; Putnam, A. E.; Strand, P.; Radue, M. J.

2017-12-01

The lead author, an Environmental Science teacher at Gary Comer High School (GCHS), a public charter on the South Side of Chicago, accompanied two students over the course of two summers to conduct field research in remote mountain ranges of interior Asia. The expeditions were funded by the National Science Foundation and orchestrated collaboratively with PI Putnam with the purposes of bringing along high school students and teachers (1) to introduce students from urban areas to practical Earth Science and (2) to bolster the Environmental Science curriculum at GCHS by providing real world events to relate to classroom learning. During the first field trip, a student from GCHS and the lead author traveled to western Mongolia to participate in collecting samples for cosmogenic-nuclide dating of glacial landforms. The student performed all parts of sample collection and used the data to create a poster analyzing the rate of recession of the Potanin Glacier. She went on to present her findings at the AGU Fall Meeting 2016. At GCHS, she assisted the teacher in lessons about climate change. Next year she will be attending the University of Vermont to pursue a major in a STEM field. The second student traveled to the Tibetan Plateau in China and also participated fully in sampling activities. She plans on presenting her project on creating 3D models of sample boulders at the AGU Meeting in 2017. She will present her findings to the rest of the student body at GCHS, assist with pertinent Environmental Science lessons for Freshmen, and explain her experience at the Gary Comer Middle School. The lead author faced several restrictions in the classroom due to standardized testing requirements, leading to more focus on testing skills rather than investigative learning. Next year the focus will switch from ACT to SAT standards, allowing more freedom to pursue investigative lessons. The success of adding information on the field experience will be assessed at the end of the 2017

An Investigation of Hall Currents Associated with Tripolar Magnetic Fields During Magnetospheric Kelvin Helmholtz Waves

Science.gov (United States)

Sturner, A. P.; Eriksson, S.; Newman, D. L.; Lapenta, G.; Gershman, D. J.; Plaschke, F.; Ergun, R.; Wilder, F. D.; Torbert, R. B.; Giles, B. L.; Strangeway, R. J.; Russell, C. T.; Burch, J. L.

2016-12-01

Kinetic simulations and observations of magnetic reconnection suggest the Hall term of Ohm's Law is necessary for understanding fast reconnection in the Earth's magnetosphere. During high (>1) guide field plasma conditions in the solar wind and in Earth's magnetopause, tripolar variations in the guide magnetic field are often observed during current sheet crossings, and have been linked to reconnection Hall magnetic fields. Two proposed mechanisms for these tripolar variations are the presence of multiple nearby X-lines and magnetic island coalescence. We present results of an investigation into the structure of the electron currents supporting tripolar guide magnetic field variations during Kelvin-Helmholtz wave current sheet crossings using the Magnetosphere Multiscale (MMS) Mission, and compare with bipolar magnetic field structures and with kinetic simulations to understand how these tripolar structures may be used as tracers for magnetic islands.

Scientific investigation plan for initial engineered barrier system field tests

International Nuclear Information System (INIS)

Wunan Lin.

1993-02-01

The purpose of this Scientific Investigation Plan (SIP) is to describe tests known as Initial Engineered Barrier System Field Tests (IEBSFT) and identified by Work Breakdown Structure as WBS 1.2.2.2.4. The IEBSFT are precursors to the Engineered Barrier System Field Test (EBSFT), WBS 1.2.2.2.4, to be conducted in the Exploratory Study Facility (ESF) at Yucca Mountain. The EBSFT and IEBSFT are designed to provide information on the interaction between waste packages (simulated by heated containers) and the surrounding rock mass, its vadose water, and infiltrated water. Heater assemblies will be installed in drifts or boreholes openings and heated to measure moisture movement during heat-up and subsequent cool-down of the rock mass. In some of the tests, infiltration of water into the heated rock mass will be studied. Throughout the heating and cooling cycle, instruments installed in the rock will monitor such parameters as temperature, moisture content, concentration of some chemical species, and stress and strain. Rock permeability measurements, rock and fluid (water and gas) sampling, and fracture pattern measurements will also be made before and after the test

Experimental investigation on the repetitively nanosecond pulsed dielectric barrier discharge with the parallel magnetic field

Science.gov (United States)

Liu, Yidi; Yan, Huijie; Guo, Hongfei; Fan, Zhihui; Wang, Yuying; Ren, Chunsheng

2018-02-01

The effects of a parallel magnetic field on the unipolar positive nanosecond pulsed dielectric barrier discharge are experimentally investigated through electrical and spectral measurements. The discharge is produced between two parallel-plate electrodes in the ambient air with a parallel magnetic field of 1.4 T. Experimental results show that both the discharge intensity and uniformity are improved in the discharge with the parallel magnetic field. The intensity ratio of the spectrum at 371.1 nm and 380.5 nm, which describes the average electron density, is increased by the parallel magnetic field. Meanwhile, the intensity ratio of the spectrum at 391.4 nm and 337.1 nm, which describes the electron temperature, is also increased. It is speculated that both the average electron density and the electron temperature are increased by the parallel magnetic field. The aforementioned phenomena have been explained by the confinement effect of the parallel magnetic field on the electrons.

Energy balance concept in the evaluation of water table management effects on corn growth: experimental investigation

International Nuclear Information System (INIS)

Kalita, P.K.; Kanwar, R.S.

1992-01-01

The effects of water table management practices (WTMP) on corn growth in 1989 and 1990 at two field sites, Ames and Ankeny, Iowa, were evaluated by calculating crop water stress index (CWSI) and monitoring plant physiological parameters during the growing seasons. Experiments were conducted on field lysimeters at the Ames site by maintaining water tables at 0.3-, 0.6-, and 0.9-m depths and in a subirrigation field at the Ankeny site with 0.2-, 0.3-, 0.6-, 0.9-, and 1.1-m water table depths, and periodically measuring leaf and air temperature, transpiration rate, stomatal conductance, and photosynthetically active radiation (PAR) using leaf chamber techniques. Net radiation of canopy was estimated using the leaf energy balance equation and leaf chamber measurements and then correlated with PAR. Analysis of data revealed that net radiation, leaf air temperature differential, transpiration rate, stomatal conductance, and CWSI were strongly related to WTMP during vegetative and flowering stages of corn growth. Excess water in the root zone with a water table depth of 0.2 m caused the maximum crop water stress and ceased crop growth. Both water and oxygen could be adequately maintained for favorable crop growth by adopting the best WTMP. Results indicate that plant physiological parameters and CWSI could be used to evaluate the effectiveness of WTMP and develop the best WTMP for corn growth in the humid region

Investigations of solutions of Einstein's field equations close to λ-Taub-NUT

International Nuclear Information System (INIS)

Beyer, Florian

2008-01-01

We present investigations of a class of solutions of Einstein's field equations close to the family of λ-Taub-NUT spacetimes. The studies are done using a numerical code introduced by the author elsewhere. One of the main technical complications is due to the paragraph -topology of the Cauchy surfaces. Complementing these numerical results with heuristic arguments, we are able to yield some first insights into the strong cosmic censorship issue and the conjectures by Belinskii, Khalatnikov and Lifschitz in this class of spacetimes. In particular, the current investigations suggest that strong cosmic censorship holds in this class. We further identify open issues in our current approach and point to future research projects

Results of investigations at the Zunil geothermal field, Guatemala: Well logging and brine geochemistry

Energy Technology Data Exchange (ETDEWEB)

Adams, A.; Dennis, B.; Van Eeckhout, E.; Goff, F.; Lawton, R.; Trujillo, P.E.; Counce, D.; Archuleta, J. (Los Alamos National Lab., NM (USA)); Medina, V. (Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico)

1991-07-01

The well logging team from Los Alamos and its counterpart from Central America were tasked to investigate the condition of four producing geothermal wells in the Zunil Geothermal Field. The information obtained would be used to help evaluate the Zunil geothermal reservoir in terms of possible additional drilling and future power plant design. The field activities focused on downhole measurements in four production wells (ZCQ-3, ZCQ-4, ZCQ-5, and ZCQ-6). The teams took measurements of the wells in both static (shut-in) and flowing conditions, using the high-temperature well logging tools developed at Los Alamos National Laboratory. Two well logging missions were conducted in the Zunil field. In October 1988 measurements were made in well ZCQ-3, ZCQ-5, and ZCQ-6. In December 1989 the second field operation logged ZCQ-4 and repeated logs in ZCQ-3. Both field operations included not only well logging but the collecting of numerous fluid samples from both thermal and nonthermal waters. 18 refs., 22 figs., 7 tabs.

The influence of small-mammal burrowing activity on water storage at the Hanford Site

International Nuclear Information System (INIS)

Landeen, D.S.

1994-01-01

This paper summarizes the activities that were conducted in support of the long-term surface barrier development program by Westinghouse Hanford Company to determine the degree that small-mammal burrow systems affect the loss or retention of water in the soils at the Hanford Site in Washington state. An animal intrusion lysimeter facility was constructed, consisting of two outer boxes buried at grade, which served as receptacles for six animal intrusion lysimeters. Small burrowing animals common the Hanford Site were introduced over a 3- to 4-month period. Supplemental precipitation was added monthly to three of the lysimeters with a rainfall simulator (rainulator). Information collected from the five tests indicated that (1) during summer months, water was lost in all the lysimeters, including the supplemental precipitation added with the rainulator; and (2) during winter months, all lysimeters gained water. The data indicate little difference in the amount of water stored between control and animal lysimeters. The overall water loss was attributed to surface evaporation, a process that occurred equally in control and treatment lysimeters. Other causes of water loss are a result of (1) constant soil turnover and subsequent drying, and (2) burrow ventilation effects. This suggests that burrow systems will not contribute to any significant water storage at depth and, in fact, may enhance the removal of water from the soil

Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 3: Ecological risk assessment

Energy Technology Data Exchange (ETDEWEB)

Hlohowskyj, I.; Hayse, J.; Kuperman, R.; Van Lonkhuyzen, R.

2000-02-25

The Environmental Management Division of the U.S. Army Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation (RI) and feasibility study (FS) of the J-Field area at APG, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of that activity, Argonne National Laboratory (ANL) conducted an ecological risk assessment (ERA) of the J-Field site. This report presents the results of that assessment.

Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 3: Ecological risk assessment

International Nuclear Information System (INIS)

Hlohowskyj, I.; Hayse, J.; Kuperman, R.; Van Lonkhuyzen, R.

2000-01-01

The Environmental Management Division of the U.S. Army Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation (RI) and feasibility study (FS) of the J-Field area at APG, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of that activity, Argonne National Laboratory (ANL) conducted an ecological risk assessment (ERA) of the J-Field site. This report presents the results of that assessment

Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

Directory of Open Access Journals (Sweden)

Fuangpian Phanupong

2016-01-01

Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

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

International Field Research with Undergraduate Students: Investigating Active Tectonics of the Nicoya Peninsula, Costa Rica

Science.gov (United States)

Marshall, J. S.; Gardner, T. W.; Protti, M.

2005-12-01

Over the past eight years, 18 undergraduate students from 12 U.S. and Costa Rican universities and colleges have participated in field research projects investigating coastal tectonics on the Nicoya Peninsula, Costa Rica. These projects have been organized around two different models: 1) a month-long "field camp" with 10 students and 5 project faculty (Keck Geology Consortium Project, 1998), and 2) several two-week field projects with 1-3 students and one faculty advisor (Cal Poly Pomona University and Trinity University). Under the direction of the authors, each of these projects has been carefully designed to provide a new piece to a larger research puzzle. The Nicoya Peninsula lies along Costa Rica's northern Pacific coast inboard of the Middle America Trench where the Cocos and Caribbean plates converge at 10 cm/yr. In 1950, the peninsula was shaken by a ~M 7.7 subduction earthquake that produced widespread damage and 0.5-1.0 m of coseismic coastal uplift. With a large slip deficit since 1950, the Nicoya Peninsula is viewed as a high-potential seismic gap. Field study of uplifted Quaternary marine terraces along the Nicoya coastline provides undergraduate students with a unique opportunity to examine rapid forearc deformation related to large subduction earthquakes. The field research conducted by each of these students provides the basis for a senior thesis at their home institution. In most cases, the students have focused their individual work on separate, but adjacent field areas. Collectively, each of these projects has generated significant data that contribute toward of an ongoing investigation of fore arc tectonics and subduction cycle earthquakes along the Costa Rican Pacific margin.

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.

Investigating the Effect of Soil Texture and Fertility on Evapotranspiration and Crop Coefficient of Maize Forage

Directory of Open Access Journals (Sweden)

M. Ghorbanian Kerdabadi

2017-02-01

Full Text Available Introduction: Crop coefficient varies in different environmental conditions, such as deficit irrigation, salinity and intercropping. The effect of soil fertility and texture of crop coefficient and evapotranspiration of maize was investigated in this study. Low soil fertility and food shortages as a stressful environment for plants that makes it different evapotranspiration rates of evapotranspiration calculation is based on the FAO publication 56. Razzaghi et al. (2012 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. Zhang et al (2014 were investigated the Effect of adding different amounts of nitrogen during three years (from 2010 to 2012 on water use efficiency and crop evapotranspiration two varieties of winter wheat. The results of their study showed. The results indicated the following: (1 in this dry land farming system, increased N fertilization could raise wheat yield, and the drought-tolerant Changhan No. 58 showed a yield advantage in drought environments with high N fertilizer rates; (2 N application affected water consumption in different soil layers, and promoted wheat absorbing deeper soil water and so increased utilization of soil water; and (3 comprehensive consideration of yield and WUE of wheat indicated that the N rate of 270 kg/ha for Changhan No. 58 was better to avoid the risk of reduced production reduction due to lack of precipitation; however, under conditions of better soil moisture, the N rate of 180 kg/ha was more economic. Materials and Methods: The study was a factorial experiment in a completely randomized design with three soil texture treatment, including silty clay loam, loam and sandy-loam soil and three fertility treatment, including without fertilizer, one and two percent fertilizer( It was conducted at the experimental farm in

An isotopic view of water and nitrate transport through the vadose zone in Oregon's southern Willamette Valley's Groundwater Management Area

Science.gov (United States)

Brooks, J. R.; Pearlstein, S.; Hutchins, S.; Faulkner, B. R.; Rugh, W.; Willard, K.; Coulombe, R.; Compton, J.

2017-12-01

Groundwater nitrate contamination affects thousands of households in Oregon's southern Willamette Valley and many more across the USA. The southern Willamette Valley Groundwater Management Area (GWMA) was established in 2004 due to nitrate levels in the groundwater exceeding the human health standard of 10 mg nitrate-N L-1. Much of the nitrogen (N) inputs to the GWMA comes from agricultural fertilizers, and thus efforts to reduce N inputs to groundwater are focused upon improving N management. However, the effectiveness of these improvements on groundwater quality is unclear because of the complexity of nutrient transport through the vadose zone and long groundwater residence times. Our objective was to focus on vadose zone transport and understand the dynamics and timing of N and water movement below the rooting zone in relation to N management and water inputs. Stable isotopes are a powerful tool for tracking water movement, and understanding N transformations. In partnership with local farmers and state agencies, we established lysimeters and groundwater wells in multiple agricultural fields in the GWMA, and have monitored nitrate, nitrate isotopes, and water isotopes weekly for multiple years. Our results indicate that vadose zone transport is highly complex, and the residence time of water collected in lysimeters was much longer than expected. While input precipitation water isotopes were highly variable over time, lysimeter water isotopes were surprisingly consistent, more closely resembling long-term precipitation isotope means rather than recent precipitation isotopic signatures. However, some particularly large precipitation events with unique isotopic signatures revealed high spatial variability in transport, with some lysimeters showing greater proportions of recent precipitation inputs than others. In one installation where we have groundwater wells and lysimeters at multiple depths, nitrate/nitrite concentrations decreased with depth. N concentrations

Investigation on wind turbine wakes: wind tunnel tests and field experiments with LIDARs

Science.gov (United States)

Iungo, Giacomo; Wu, Ting; Cöeffé, Juliette; Porté-Agel, Fernando; WIRE Team

2011-11-01

An investigation on the interaction between atmospheric boundary layer flow and wind turbines is carried out with wind tunnel and LIDAR measurements. The former were carried out using hot-wire anemometry and multi-hole pressure probes in the wake of a three-bladed miniature wind turbine. The wind turbine wake is characterized by a strong velocity defect in the proximity of the rotor, and its recovery is found to depend on the characteristics of the incoming atmospheric boundary layer (mean velocity and turbulence intensity profiles). Field experiments were performed using three wind LIDARs. Bi-dimensional scans are performed in order to analyse the wake wind field with different atmospheric boundary layer conditions. Furthermore, simultaneous measurements with two or three LIDARs allow the reconstruction of multi-component velocity fields. Both LIDAR and wind tunnel measurements highlight an increased turbulence level at the wake boundary for heights comparable to the top-tip of the blades; this flow feature can produce dangerous fatigue loads on following wind turbines.

Rapid core field variations during the satellite era: Investigations using stochastic process based field models

DEFF Research Database (Denmark)

Finlay, Chris; Olsen, Nils; Gillet, Nicolas

We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to tradition...... physical hypotheses can be tested by asking questions of the entire ensemble of core field models, rather than by interpreting any single model.......We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to traditional...... regularization methods based on minimizing the square of second or third time derivative. We invert satellite and observatory data directly by adopting the external field and crustal field modelling framework of the CHAOS model, but apply the stochastic process method of Gillet et al. (2013) to the core field...

Investigation of the field dependent spin structure of exchange coupled magnetic heterostructures

International Nuclear Information System (INIS)

Gurieva, Tatiana

2016-05-01

This thesis describes the investigation of the field dependent magnetic spin structure of an antiferromagnetically (AF) coupled Fe/Cr heterostructure sandwiched between a hardmagnetic FePt buffer layer and a softmagnetic Fe top layer. The depth-resolved experimental studies of this system were performed via Magneto-optical Kerr effect (MOKE), Vibrating Sample Magnetometry (VSM) and various measuring methods based on nuclear resonant scattering (NRS) technique. Nucleation and evolution of the magnetic spiral structure in the AF coupled Fe/Cr multilayer structure in an azimuthally rotating external magnetic field were observed using NRS. During the experiment a number of time-dependent magnetic side effects (magnetic after-effect, domain-wall creep effect) caused by the non-ideal structure of a real sample were observed and later explained. Creation of the magnetic spiral structure in rotating external magnetic field was simulated using a one-dimensional micromagnetic model.The cross-sectional magnetic X-ray diffraction technique was conceived and is theoretically described in the present work. This method allows to determine the magnetization state of an individual layer in the magnetic heterostructure. It is also applicable in studies of the magnetic structure of tiny samples where conventional x-ray reflectometry fails.

Investigation of Workplace-like Calibration Fields via a Deuterium-Tritium (D-T) Neutron Generator.

Science.gov (United States)

Mozhayev, Andrey V; Piper, Roman K; Rathbone, Bruce A; McDonald, Joseph C

2017-04-01

Radiation survey meters and personal dosimeters are typically calibrated in reference neutron fields based on conventional radionuclide sources, such as americium-beryllium (Am-Be) or californium-252 (Cf), either unmodified or heavy-water moderated. However, these calibration neutron fields differ significantly from the workplace fields in which most of these survey meters and dosimeters are being used. Although some detectors are designed to yield an approximately dose-equivalent response over a particular neutron energy range, the response of other detectors is highly dependent upon neutron energy. This, in turn, can result in significant over- or underestimation of the intensity of neutron radiation and/or personal dose equivalent determined in the work environment. The use of simulated workplace neutron calibration fields that more closely match those present at the workplace could improve the accuracy of worker, and workplace, neutron dose assessment. This work provides an overview of the neutron fields found around nuclear power reactors and interim spent fuel storage installations based on available data. The feasibility of producing workplace-like calibration fields in an existing calibration facility has been investigated via Monte Carlo simulations. Several moderating assembly configurations, paired with a neutron generator using the deuterium tritium (D-T) fusion reaction, were explored.

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.

Overview of the geochemical code MINTEQ: applications to performance assessment for low-level wastes

International Nuclear Information System (INIS)

Graham, M.J.; Peterson, S.R.

1985-09-01

The MINTEQ geochemical computer code, developed at Pacific Northwest Laboratory, integrates many of the capabilities of its two immediate predecessors, WATEQ3 and MINEQL. MINTEQ can be used to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments or the interaction of ground water with solidified low-level wastes. The code is capable of performing calculations of ion speciation/solubility, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial solidified low-level wastes. The wastes being evaluated include power reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code is being upgraded before the geochemical modeling is performed. Thermodynamic data for cobalt, antimony, cerium, and cesium solid phases and aqueous species are being added to the database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the wastes predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partical field validation of the geochemical model. 28 refs

Barrier erosion control test plan: Gravel mulch, vegetation, and soil water interactions

Energy Technology Data Exchange (ETDEWEB)

Waugh, W.J.; Link, S.O. (Pacific Northwest Lab., Richland, WA (USA))

1988-07-01

Soil erosion could reduce the water storage capacity of barriers that have been proposed for the disposal of near-surface waste at the US Department of Energy's Hanford Site. Gravel mixed into the top soil surface may create a self-healing veneer that greatly retards soil loss. However, gravel admixtures may also enhance infiltration of rainwater, suppress plant growth and water extraction, and lead to the leaching of underlying waste. This report describes plans for two experiments that were designed to test hypotheses concerning the interactive effects of surface gravel admixtures, revegetation, and enhanced precipitation on soil water balance and plant abundance. The first experiment is a factorial field plot set up on the site selected as a soil borrow area for the eventual construction of barriers. The treatments, arranged in a a split-split-plot design structure, include two densities of gravel admix, a mixture of native and introduced grasses, and irrigation to simulate a wetter climate. Changes in soil water storage and plant cover are monitored with neutron moisture probes and point intercept sampling, respectively. The second experiment consists of an array of 80 lysimeters containing several different barrier prototypes. Surface treatments are similar to the field-plot experiment. Drainage is collected from a valve at the base of each lysimeter tube, and evapotranspiration is estimated by subtraction. The lysimeters are also designed to be coupled to a whole-plant gas exchange system that will be used to conduct controlled experiments on evapotranspiration for modeling purposes. 56 refs., 6 figs., 8 tabs.

Initial Results from the Vector Electric Field Investigation on the C/NOFS Satellite

Science.gov (United States)

Pfaff, R.; Rowland, D.; Acuna, M.; Le, G.; Farrell, W.; Holzworth, R.; Wilson, G.; Burke, W.; Freudenreich, H.; Bromund, K.;

An investigation of singular Lagrangians as field systems

International Nuclear Information System (INIS)

Rabei, E.M.

1995-07-01

The link between the treatment of singular Lagrangians as field systems and the general approach is studied. It is shown that singular Lagrangians as field systems are always in exact agreement with the general approach. Two examples and the singular Lagrangian with zero rank Hessian matrix are studied. The equations of motion in the field systems are equivalent to the equations which contain acceleration, and the constraints are equivalent to the equations which do not contain acceleration in the general approach treatment. (author). 10 refs

Annual report 1986 of the GSF Institute of Radiohydrometry

International Nuclear Information System (INIS)

1987-02-01

Sorption data of radionnuclides in cohesive materials are measured by batch experiments or by single-pass column experiments. New developments of equipment are explained, as for instance the H-2-uranium measuring device, the isotope dating of ground water with Ar-39, and measurement of Kr-35 in air. Field epxeriments are explained, such as studies of the fields of ground-water flow using tracer methods, hydrological methods and lysimeter techniques. (DG) [de

Investigations of the magnetic fields from ships due to corrosion and its countermeasures

Science.gov (United States)

Allan, Peter J.

Corrosion is one of the main concerns for the shipping industry. The enormous cost associated with the corrosion of ships means that operators are more than ever seeking methods to provide optimal protection. Another problem which results from the corrosion of ships is that the electric currents produced give rise to a corrosion related magnetic field which adds to the ships overall electromagnetic field which can trigger underwater mines. Hence for the Admiralty to protect their fleet, they need to understand, predict and reduce these electromagnetic signatures. This will also be a concern for operators of merchant ships if, as recently suggested, terrorists begin to target them. There are a number of factors contributing to the electromagnetic signature of a ship. The work presented in this study is concerned with the magnetic field arising due to corrosion and the countermeasures employed against it (namely Impressed Current Cathodic Protection (ICCP) systems]. This field is called the Corrosion Related Magnetic (CRM) field. Since this field is directly related to the rate of corrosion of a ship, it may also be used as an indicator as to the efficiency of the corrosion protection measures, This work presents a range of techniques which may be used to model the CRM field. Simple dipole models are used to investigate the general behaviour of a corroding ship in sea water. These investigations result in an expression for an approximation of the CRM field from a dipole-wire configuration which can be used to estimate the CRM field from a corroding ship with an active ICCP system. A second, more detailed, method was then developed using the Boundary Element Method (BEM) to model a ship corroding in a tank of sea water. The BEM uses a large set of simultaneous equations, the coefficients of which are calculated by numerical integration using a new method based around the moments of triangular surface elements which discretise the boundary of the domain. By using a

Risk analysis of bioprocesses based on genetically modified bacteria. Pathway and exposure modeling

Energy Technology Data Exchange (ETDEWEB)

Rein, A.; Bittens, M. [Tuebingen Univ. (Germany). Zentrum fuer Angewandte Geowissenschaften

2003-07-01

For soils contaminated with polychlorinated biphenyls (PCBs), a plant-microorganism system for in situ - bioremediation has been developed. It consists of genetically modified microorganisms (GMOs) in conjunction with plant roots. The GMOs are Pseudomonas fluorescens strains which are genetically engineered to degrade PCB congeners in situ. Their metabolism requires root exudates and is therefore tightly coupled to plant rhizospheres. Compared to wild type organisms, the genetically modified bacteria develop a specificity to PCB as a substrate and therefore foster biodegradation in a more efficient way. To evaluate the efficiency and impact of this bioremediation system for potential field application, lysimeter tests are carried out. The lysimeters are filled with contaminated soil from a PCB release site in Denmark and planted with GMO inoculated plants. On the basis of these experiments, a detailed risk analysis is carried out to obtain conclusions to field-conditions (potential deliberate GMO-release). A qualitative and quantitative assessment of actual or potential effects is performed, addressing transport, fate and exposure of PCBs, GMOs and specific degradation products in different environmental compartments. (orig.)

Impact of different plants on the gas profile of a landfill cover

International Nuclear Information System (INIS)

Reichenauer, Thomas G.; Watzinger, Andrea; Riesing, Johann; Gerzabek, Martin H.

2011-01-01

Research highlights: → Plants influence gas profile and methane oxidation in landfill covers. → Plants regulate water content and increase the availability of oxygen for methane oxidation. → Plant species with deep roots like alfalfa showed more stimulation of methane oxidation than plants with shallow root systems like grasses. - Abstract: Methane is an important greenhouse gas emitted from landfill sites and old waste dumps. Biological methane oxidation in landfill covers can help to reduce methane emissions. To determine the influence of different plant covers on this oxidation in a compost layer, we conducted a lysimeter study. We compared the effect of four different plant covers (grass, alfalfa + grass, miscanthus and black poplar) and of bare soil on the concentration of methane, carbon dioxide and oxygen in lysimeters filled with compost. Plants were essential for a sustainable reduction in methane concentrations, whereas in bare soil, methane oxidation declined already after 6 weeks. Enhanced microbial activity - expected in lysimeters with plants that were exposed to landfill gas - was supported by the increased temperature of the gas in the substrate and the higher methane oxidation potential. At the end of the first experimental year and from mid-April of the second experimental year, the methane concentration was most strongly reduced in the lysimeters containing alfalfa + grass, followed by poplar, miscanthus and grass. The observed differences probably reflect the different root morphology of the investigated plants, which influences oxygen transport to deeper compost layers and regulates the water content.

The investigation of fetal doses in mantle field irradiation

International Nuclear Information System (INIS)

Karacam, S. C; Gueralp, O. S; Oeksuez, D. C; Koca, A.; Cepni, I.; Cepni, K.; Bese, N.

2009-01-01

To determine clinically the fetal dose from irradiation of Hodgkin's disease during pregnancy and to quantify the components of fetal dose using phantom measurements. The fetal dose was measured with phantom measurements using thermoluminescent dosemeters (TLDs). Phantom measurements were performed by simulating the treatment conditions on an anthropomorphic phantom. TLDs were placed on the phantom 41, 44, 46.5 and 49.5 cm from the centre of the treatment field. Two TLDs were placed on the surface of the phantom. The estimated total dose to all the TLDs ranged from 8.8 to 13.2 cGy for treatment with 60 Co and from 8.2 to 11.8 cGy for 4 MV photons. It was concluded that the doses in different sections were evaluated to investigate dose changes in different points and depths of fetal tissues in phantom. Precise planning and the use of supplemental fetal shielding may help reduce fetal exposure. (authors)

Experimental and computational investigation of the NASA low-speed centrifugal compressor flow field

Science.gov (United States)

Hathaway, Michael D.; Chriss, Randall M.; Wood, Jerry R.; Strazisar, Anthony J.

1993-01-01

An experimental and computational investigation of the NASA Lewis Research Center's low-speed centrifugal compressor (LSCC) flow field was conducted using laser anemometry and Dawes' three-dimensional viscous code. The experimental configuration consisted of a backswept impeller followed by a vaneless diffuser. Measurements of the three-dimensional velocity field were acquired at several measurement planes through the compressor. The measurements describe both the throughflow and secondary velocity field along each measurement plane. In several cases the measurements provide details of the flow within the blade boundary layers. Insight into the complex flow physics within centrifugal compressors is provided by the computational fluid dynamics analysis (CFD), and assessment of the CFD predictions is provided by comparison with the measurements. Five-hole probe and hot-wire surveys at the inlet and exit to the impeller as well as surface flow visualization along the impeller blade surfaces provided independent confirmation of the laser measurement technique. The results clearly document the development of the throughflow velocity wake that is characteristic of unshrouded centrifugal compressors.

Alternative Landfill Cover and Monitoring Systems for Landfills in Arid Environments

International Nuclear Information System (INIS)

Rawlinson, S. E.

2002-01-01

In December 2000, a performance monitoring facility was constructed adjacent to the mixed waste disposal unit U-3ax/bl at the Area 3 Radioactive Waste Management Site at the Nevada Test Site. This facility consists of eight drainage lysimeters measuring 10 feet in diameter, 8 feet deep, and backfilled with native soil. The lysimeters have three different surface treatments: two were left bare, two were revegetated with native species, and two were allowed to revegetate with invader species (two are reserved for future studies). The lysimeters are instrumented with an array of soil water content and soil water potential sensors and have sealed bottoms so that any drainage can be measured. All sensors are working properly and indicate that the bare lysimeters are the wettest, as expected. The vegetated lysimeters, both seeded and those allowed to revegetate with invader species, are significantly drier than the bare cover treatments. No drainage has occurred in any of the lysimeters. The Accelerated Site Technology Deployment program under the U.S. Department of Energy's Office of Science and Technology provided the funding for this project with the objective of reducing the uncertainty associated with the performance of monolayer-evapotranspiration waste covers in arid regions such as the one deployed at U-3ax/bl

Investigation of air-assisted sprays submitted to high frequency transverse acoustic fields: Droplet clustering

Science.gov (United States)

Ficuciello, A.; Blaisot, J. B.; Richard, C.; Baillot, F.

2017-06-01

An experimental investigation of the effects of a high amplitude transverse acoustic field on coaxial jets is presented in this paper. Water and air are used as working fluids at ambient pressure. The coaxial injectors are placed on the top of a semi-open resonant cavity where the acoustic pressure fluctuations of the standing wave can reach a maximum peak-to-peak amplitude of 12 kPa at the forcing frequency of 1 kHz. Several test conditions are considered in order to quantify the influence of injection conditions, acoustic field amplitude, and injector position with respect to the standing wave acoustic field. A high speed back-light visualization technique is used to characterize the jet response. Image processing is used to obtain valuable information about the jet behavior. It is shown that the acoustic field drastically affects the atomization process for all atomization regimes. The position of the injector in the acoustic field determines the jet response, and a droplet-clustering phenomenon is highlighted in multi-point injection conditions and quantified by determining discrete droplet location distributions. A theoretical model based on nonlinear acoustics related to the spatial distribution of the radiation pressure exerted on an object explains the behavior observed.

[Fluorescence polarization used to investigate the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field].

Science.gov (United States)

Zhang, Ying; Zeng, Xin-An; Wen, Qi-Biao; Li, Lin

2008-01-01

To know the lethal mechanism of microorganisms under pulsed electric field treatment, the relationship between the inactivation of Saccharomyces cerevisiae (CICC1308) cell and the permeability and fluidity changes of its cell membrane treated by pulsed electric field (0-25 kV x cm(-1), 0-266 ms) was investigated. With 1,6-diphenyl-1,3,5-hexatriene (DPH) used as a probe, the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field was expressed by fluorescence polarization. Results showed that the cell membrane fluidity decreases when the electric flied strength is up to 5 kV x cm(-1), and decreases with the increase in electric field strength and treatment time. The plate counting method and ultraviolet spectrophotometer were used to determine the cell viability and to investigate the cell membrane permeability, respectively, treated by pulsed electric field. Results showed that the lethal ratio and the content of protein and nucleic acid leaked from intracellular plasma increased with the increase in the electric field strength and the extension of treatment time. Even in a quite lower electric field of 5 kV x cm(-1) with a tiny microorganism lethal level, the increase in UV absorption value and the decrease in fluidity were significant. It was demonstrated that the cell membrane fluidity decreases with the increase in lethal ratio and cell membrane permeability. The viscosity of cell membrane increases with the decrease in fluidity. These phenomena indicated that cell membrane is one of the most key sites during the pulsed electric field treatment, and the increased membrane permeability and the decreased cell membrane fluidity contribute to the cell death.

Theoretical investigation of performance of armchair graphene nanoribbon field effect transistors

Science.gov (United States)

Hur, Ji-Hyun; Kim, Deok-Kee

2018-05-01

In this paper, we theoretically investigate the highest possible expected performance for graphene nanoribbon field effect transistors (GNRFETs) for a wide range of operation voltages and device structure parameters, such as the width of the graphene nanoribbon and gate length. We formulated a self-consistent, non-equilibrium Green’s function method in conjunction with the Poisson equation and modeled the operation of nanometer sized GNRFETs, of which GNR channels have finite bandgaps so that the GNRFET can operate as a switch. We propose a metric for competing with the current silicon CMOS high performance or low power devices and explain that this can vary greatly depending on the GNRFET structure parameters.

100-FR-3 groundwater/soil gas supplemental limited field investigation report

International Nuclear Information System (INIS)

1996-04-01

In 1993, a Limited Field Investigation (LFI) was conducted for the 100-FR-3 Operable Unit which identified trichloroethylene (TCE) as a contaminant of potential concern (COPC) (DOE-RL 1994). In groundwater samples collected for the LFI, TCE was detected in well 199-177-1 at a concentration exceeding the U.S. Environmental Protection Agency (EPA) maximum contaminant level (5 μg/L) and Washington State groundwater criteria (3 μg/L). With the concurrence of the EPA and the Washington State Department of Ecology (Ecology), a supplemental LFI was conducted to determine the extent and potential source of TCE groundwater contamination associated with the 100-FR-3 Operable Unit. This report summarizes the activities and results of the groundwater/soil gas supplemental LFI for the 100-FR-3 Operable Unit. The primary objective of this investigation was to assess the lateral distribution of TCE in shallow (3 to 5 ft below the water table) groundwater associated with the 100-FR-3 Operable Unit. The second objective was to assess soil gas (3 to 5 concentrations in the study area in an attempt to identify potential sources of TCE and develop a correlation between soil gas and groundwater concentrations). Finally, the third objective of the investigation was to refine the site conceptual model

Medical investigation on the effects of radioactivity in the field of petrochemistry

International Nuclear Information System (INIS)

Li Xinluan; Gao Min; Shao Hua; Liu Wei; Li Qingjie; Hou Dianjun; Qiao Jianwei; Lin Haiqun; Shang Ximei

2005-01-01

Objective: To investigate the health condition of the people who work in the petrochemical field and to provide the basis for the policy-making of control and survey of the radiology disease. Methods: To measure the volume of radioactivity individual in the environment of the people who work in the field of petrochemistry and consequently to cheek and analysize the changes in physical and biochemistry. Results: The annual volume of radioactivity exposure individual is 5.667 mSv·a -1 , >50 mSv·a -1 20. Consequently, this volume can induce many abnormalities in human body. Compare to the control group, the abnormalities include high blood pressure of abnormal EKG, eye disease, low white blood ceels, the changed rate of CD 4 /CD 8 , distortion of DNA and appearances of higher micronucleus. Conclusion: Long time exposure to low volume of radiation will cause some of the abnormalities to humanbody. Therefore, the health protection measures should be strengthened. (authors)

Numerical investigation of magnetic field effect on pressure in cylindrical and hemispherical silicon CZ crystal growth

International Nuclear Information System (INIS)

Mokhtari, F.; Bouabdallah, A.; Merah, A.; Oualli, H.

2012-01-01

The effect of axial magnetic field of different intensities on pressure in silicon Czochralski crystal growth is investigated in cylindrical and hemispherical geometries with rotating crystal and crucible and thermocapillary convection. As one important thermodynamic variable, the pressure is found to be more sensitive than temperature to magnetic field with strong dependence upon the vorticity field. The pressure at the triple point is proposed as a convenient parameter to control the homogeneity of the grown crystal. With a gradual increase of the magnetic field intensity the convection effect can be reduced without thermal fluctuations in the silicon melt. An evaluation of the magnetic interaction parameter critical value corresponding to flow, pressure and temperature homogenization leads to the important result that a relatively low axial magnetic field is required for the spherical system comparatively to the cylindrical one. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Numerical investigation of magnetic field effect on pressure in cylindrical and hemispherical silicon CZ crystal growth

Energy Technology Data Exchange (ETDEWEB)

Mokhtari, F. [Universite Mouloud Mammeri de Tizi Ouzou (Algeria); LTSE Laboratory, University of Science and Technology. BP 32 Elalia, Babezzouar, Algiers (Algeria); Bouabdallah, A. [LTSE Laboratory, University of Science and Technology. BP 32 Elalia, Babezzouar, Algiers (Algeria); Merah, A. [LTSE Laboratory, University of Science and Technology. BP 32 Elalia, Babezzouar, Algiers (Algeria); M' hamed Bougara University, Boumerdes (Algeria); Oualli, H. [EMP, Bordj ElBahri, Algiers (Algeria)

2012-12-15

The effect of axial magnetic field of different intensities on pressure in silicon Czochralski crystal growth is investigated in cylindrical and hemispherical geometries with rotating crystal and crucible and thermocapillary convection. As one important thermodynamic variable, the pressure is found to be more sensitive than temperature to magnetic field with strong dependence upon the vorticity field. The pressure at the triple point is proposed as a convenient parameter to control the homogeneity of the grown crystal. With a gradual increase of the magnetic field intensity the convection effect can be reduced without thermal fluctuations in the silicon melt. An evaluation of the magnetic interaction parameter critical value corresponding to flow, pressure and temperature homogenization leads to the important result that a relatively low axial magnetic field is required for the spherical system comparatively to the cylindrical one. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Investigation of Magnetic Field in the Subway Station

Directory of Open Access Journals (Sweden)

Ctibor Henzl

2006-01-01

Full Text Available Paper deals with computing of magnetic field in the rails surroundings of subway (underground. The calculation of field is made by using of an analytical method in Excel VBA. There is also used commercial FEM software ANSYS and finite element method. Output results of the both methods are finally compared.

Animal intrusion status report for fiscal year 1990

International Nuclear Information System (INIS)

Landeen, D.S.

1991-03-01

The Protective Barrier and Warning Marker System Development Plan identified tasks that need to be completed to design a final protective barrier to implement in-place disposal of radioactive waste. This report summarizes the animal intrusion work conducted by Westinghouse Hanford Company in fiscal year 1990 regarding small mammals and water infiltration. An animal intrusion lysimeter facility was constructed and installed in fiscal year 1988. The facility consists of two outer boxes buried at grade that serve as receptacles for six animal intrusion lysimeters. Small burrowing mammals common to the Hanford Site environs are introduced over a 3- to 4-month period. Supplemental precipitation is added to three of the lysimeters with a rainulator at a rate equivalent to a 100-year storm. Soil moisture samples are taken before and after each test, and soil moisture measurements are also taken with a hydroprobe during the test period. During fiscal year 1990, tests three and four were completed and test five was initiated. Results of test three (summer treatment), which used Townsend ground squirrels and pocket gophers, indicated that the additional 1.5 inches of precipitation that was added with the rainulator was lost during this test. The plots that did not receive any additional precipitation all lost water (5 to 6 percent). Results from test four (winter treatment), which used pocket gophers and pocket mice, indicated that all of the lysimeters except one gained water. The two control lysimeters (rainulator plots and nonrainulator lysimeters with no animals) gained more water than their corresponding animal burrow lysimeters. 4 refs., 9 figs., 3 tabs

Investigation of parts and elements of technical reports in nuclear field in Japan

International Nuclear Information System (INIS)

Naramoto, Miyoko; Narui, Shigeko

1985-01-01

Presentation of parts and elements necessary for editing and publishing reports in accordance with SIST-09-1984 (Presentation of Scientific and Technical Reports) was investigated for 65 codes of technical reports in the nuclear field in Japan. English presentation of important elements was also investigated additionally. The investigation shows high presentation fractions (80 -- 100 %) for main bibliographic elements, and medium (66 %) and extremely low (3 %) for abntract and key word, respectively. (The bibliographic elements are described in various parts such as front cover, title page and front matter) and (the subject elements appear mainly in front matter). The title, author's name in Roman character, affiliation, publisher and abstract are described in English with fractions of 80 %, 66 %, 68 % and 62 %, respectively. It is hoped for more publishers and editors of technical reports to accept the standard SIST-09 for efficient processing of secondary information. (author)

A fully automated meltwater monitoring and collection system for spatially distributed isotope analysis in snowmelt-dominated catchments

Science.gov (United States)

Rücker, Andrea; Boss, Stefan; Von Freyberg, Jana; Zappa, Massimiliano; Kirchner, James

2016-04-01

In many mountainous catchments the seasonal snowpack stores a significant volume of water, which is released as streamflow during the melting period. The predicted change in future climate will bring new challenges in water resource management in snow-dominated headwater catchments and their receiving lowlands. To improve predictions of hydrologic extreme events, particularly summer droughts, it is important characterize the relationship between winter snowpack and summer (low) flows in such areas (e.g., Godsey et al., 2014). In this context, stable water isotopes (18O, 2H) are a powerful tool for fingerprinting the sources of streamflow and tracing water flow pathways. For this reason, we have established an isotope sampling network in the Alptal catchment (46.4 km2) in Central-Switzerland as part of the SREP-Drought project (Snow Resources and the Early Prediction of hydrological DROUGHT in mountainous streams). Samples of precipitation (daily), snow cores (weekly) and runoff (daily) are analyzed for their isotopic signature in a regular cycle. Precipitation is also sampled along a horizontal transect at the valley bottom, and along an elevational transect. Additionally, the analysis of snow meltwater is of importance. As the sample collection of snow meltwater in mountainous terrain is often impractical, we have developed a fully automatic snow lysimeter system, which measures meltwater volume and collects samples for isotope analysis at daily intervals. The system consists of three lysimeters built from Decagon-ECRN-100 High Resolution Rain Gauges as standard component that allows monitoring of meltwater flow. Each lysimeter leads the meltwater into a 10-liter container that is automatically sampled and then emptied daily. These water samples are replaced regularly and analyzed afterwards on their isotopic composition in the lab. Snow melt events as well as system status can be monitored in real time. In our presentation we describe the automatic snow lysimeter

Investigation of various cavity configurations for metamaterial-enhanced field-localizing wireless power transfer

Science.gov (United States)

Bui, Huu Nguyen; Pham, Thanh Son; Ngo, Viet; Lee, Jong-Wook

2017-09-01

Controlling power to an unintended area is an important issue for enabling wireless power transfer (WPT) systems. The control allows us to enhance efficiency as well as suppress unnecessary flux leakage. The flux leakage from WPT can be reduced effectively via selective field localization. To realize field localization, we propose the use of cavities formed on a single metamaterial slab that acts as a defected metasurface. The cavity is formed by strong field confinement using a hybridization bandgap (HBG), which is created by wave interaction with a two-dimensional array of local resonators on the metasurface. This approach using an HBG demonstrates strong field localization around the cavity regions. Motivated by this result, we further investigate various cavity configurations for different sizes of the transmitter (Tx) and receiver (Rx) resonators. Experiments show that the area of field localization increases with the number of cavities, confirming the successful control of different cavity configurations on the metasurface. Transmission measurements of different cavities show that the number of cavities is an important parameter for efficiency, and excess cavities do not enhance the efficiency but increase unnecessary power leakage. Thus, there exists an optimum number of cavities for a given size ratio between the Tx and Rx resonators. For a 6:1 size ratio, this approach achieves efficiency improvements of 3.69× and 1.59× compared to free space and a uniform metasurface, respectively. For 10:1 and 10:2 size ratios, the efficiency improvements are 3.26× and 1.98× compared to free space and a uniform metasurface, respectively.

Investigating Non-Equilibrium Fluctuations of Nanocolloids in a Magnetic Field Using Direct Imaging Methods

Science.gov (United States)

Rice, Ashley; Oprisan, Ana; Oprisan, Sorinel; Rice-Oprisan College of Charleston Team

Nanoparticles of iron oxide have a high surface area and can be controlled by an external magnetic field. Since they have a fast response to the applied magnetic field, these systems have been used for numerous in vivo applications, such as MRI contrast enhancement, tissue repair, immunoassay, detoxification of biological fluids, hyperthermia, drug delivery, and cell separation. We performed three direct imaging experiments in order to investigate the concentration-driven fluctuations using magnetic nanoparticles in the absence and in the presence of magnetic field. Our direct imaging experimental setup involved a glass cell filled with magnetic nanocolloidal suspension and water with the concentration gradient oriented against the gravitational field and a superluminescent diode (SLD) as the light source. Nonequilibrium concentration-driven fluctuations were recorded using a direct imaging technique. We used a dynamic structure factor algorithm for image processing in order to compute the structure factor and to find the power law exponents. We saw evidence of large concentration fluctuations and permanent magnetism. Further research will use the correlation time to approximate the diffusion coefficient for the free diffusion experiment. Funded by College of Charleston Department of Undergraduate Research and Creative Activities SURF grant.

Hanford protective barriers program: Status of asphalt barrier studies - FY 1989

International Nuclear Information System (INIS)

Freeman, H.D.; Gee, G.W.

1989-11-01

The Hanford Protective Barrier Program is evaluating alternate barriers to provide a means of meeting stringent water infiltration requirements. One type of alternate barrier being considered is an asphalt-based layer, 1.3 to 15 cm thick. Evaluations of these barriers were initiated in FY 1988, and, based on laboratory studies, two asphalt formulations were selected for further testing in small-tube lysimeters: a hot rubberized asphalt and an admixture of cationic asphalt emulsion and concrete sand containing 24 wt% residual asphalt. Eight lysimeters containing asphalt seals were installed as part of the Small Tube Lysimeter Test Facility on the Hanford Site. Two control lysimeters containing Hanford sand with a surface gravel treatment were also installed for comparison. 5 refs., 13 figs., 1 tab

Limited field investigation report for the 100-HR-3 operable unit

International Nuclear Information System (INIS)

1994-09-01

This limited field investigation (LFI) was conducted to assess the applicability of interim remedial measures (IRM) for reducing human health and environmental risks within the 100-HR-3 Groundwater Operable Unit. The 100-HR-3 Operable Unit is comprised of three subareas; the 100 D Area, the 100 H Area and those portions of the 600 Area between the two reactor areas. The operable unit is one of seven operable units associated with the 100 D and H Areas. Operable units 100-DR-1, 100-DR-2, 100-DR-3, 100-HR-1, 100-HR-2 and 100-IU-4 address contaminant sources while 100-HR-3 addresses contamination present in the underlying groundwater. The primary method of field investigation used during this LFI was the installation and sampling of monitoring wells. Samples were collected from the groundwater and soils, and submitted for laboratory analysis. Boreholes were surveyed for radiological contamination using downhole geophysical techniques to further delineate the locations and levels of contaminants. All samples were screened to ascertain the presence of volatile organic compounds and radionuclides. Analytical data were subjected to validation; all round one, two and three and a minimum of 10% of round four data associated with the LFI were validated. A screening method was used to identify contaminants of potential concern (COPC). This screening method eliminated from further consideration, constituents that were below background. Constituents which are considered non-toxic to humans were eliminated from the human health evaluation. Data consistency and blank contamination were also evaluated in the screening process. These COPC were then evaluated further in the qualitative risk assessment (QRA). A human health QRA was performed using conservative (maximum equilibrated contaminant levels from the LFI) analyses

Investigation of Horizontal Velocity Fields in Stirred Vessels with Helical Coils by PIV

Directory of Open Access Journals (Sweden)

Volker Bliem

2014-01-01

Full Text Available Horizontal velocity flow fields were measured by particle image velocimetry for a stirred vessel with baffles and two helical coils for enlargement of heat transfer area. The investigation was carried out in a cylindrical vessel with flat base and two different stirrers (radial-flow Rushton turbine and axial-flow propeller stirrer. Combined velocity plots for flow fields at different locations are presented. It was found that helical coils change the flow pattern significantly. Measurements for the axial-flow Rushton turbine showed a strong deflection by the coils, leading to a mainly tangential flow pattern. Behind baffles large areas of unused heat transfer area were found. First results for the axial-flow propeller reveal an extensive absence of fluid movement in the horizontal plane. Improved design considerations for enhanced heat transfer by more compatible equipment compilation are proposed.

Investigation and optimization of the magnetic field configuration in high-power impulse magnetron sputtering

International Nuclear Information System (INIS)

Yu, He; Meng, Liang; Szott, Matthew M; Meister, Jack T; Cho, Tae S; Ruzic, David N

2013-01-01

An effort to optimize the magnetic field configuration specifically for high-power impulse magnetron sputtering (HiPIMS) was made. Magnetic field configurations with different field strengths, race track widths and race track patterns were designed using COMSOL. Their influence on HiPIMS plasma properties was investigated using a 36 cm diameter copper target. The I–V discharge characteristics were measured. The temporal evolution of electron temperature (T e ) and density (n e ) was studied employing a triple Langmuir probe, which was also scanned in the whole discharge region to characterize the plasma distribution and transport. Based on the studies, a closed path for electrons to drift along was still essential in HiPIMS in order to efficiently confine electrons and achieve a high pulse current. Very dense plasmas (10 19 –10 20 m −3 ) were generated in front of the race tracks during the pulse, and expanded downstream afterwards. As the magnetic field strength increased from 200 to 800 G, the expansion became faster and less isotropic, i.e. more directional toward the substrate. The electric potential distribution accounted for these effects. Varied race track widths and patterns altered the plasma distribution from the target to the substrate. A spiral-shaped magnetic field design was able to produce superior plasma uniformity on the substrate in addition to improved target utilization. (paper)

Numerical Investigation of the Effect of Magnetic Field on Natural Convection in a Curved-Shape Enclosure

Directory of Open Access Journals (Sweden)

M. Sheikholeslami

2013-01-01

Full Text Available This investigation reports the magnetic field effect on natural convection heat transfer in a curved-shape enclosure. The numerical investigation is carried out using the control volume-based-finite element method (CVFEM. The numerical investigations are performed for various values of Hartmann number and Rayleigh number. The obtained results are depicted in terms of streamlines and isotherms which show the significant effects of Hartmann number on the fluid flow and temperature distribution inside the enclosure. Also, it was found that the Nusselt number decreases with an increase in the Hartmann number.

Remedial Investigation Work Plan for J-Field, Aberdeen Proving Ground, Maryland

Energy Technology Data Exchange (ETDEWEB)

Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Haffenden, R.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

1995-03-01

The purpose of an RI/FS is to characterize the nature and extent of the risks posed by contaminants present at a site and to develop and evaluate options for remedial actions. The overall objective of the RI is to provide a comprehensive evaluation of site conditions, types and quantities of contaminants present, release mechanisms and migration pathways, target populations, and risks to human health and the environment. The information developed during the RI provides the basis for the design and implementation of remedial actions during the FS. The purpose of this RI Work Plan is to define the tasks that will direct the remedial investigation of the J-Field site at APG.

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.

Policy Forum: Studying Eyewitness Investigations in the Field

Science.gov (United States)

Dawes, Robyn; Jacoby, Larry L.; Kahneman, Daniel; Lempert, Richard; Roediger, Henry L.; Rosenthal, Robert

2007-01-01

This article considers methodological issues arising from recent efforts to provide field tests of eyewitness identification procedures. We focus in particular on a field study (Mecklenburg 2006) that examined the “double blind, sequential” technique, and consider the implications of an acknowledged methodological confound in the study. We explain why the confound has severe consequences for assessing the real-world implications of this study. PMID:17610149

Attenuation of heavy metal leaching from hazardous wastes by co-disposal of wastes

Energy Technology Data Exchange (ETDEWEB)

Bae, Wookeun; Shin, Eung Bai [Hanyang Univ., Ansan (Korea, Republic of); Lee, Kil Chul; Kim, Jae Hyung [National Institute of Environmental Research, Seoul (Korea, Republic of)] [and others

1996-12-31

The potential hazard of landfill wastes was previously evaluated by examining the extraction procedures for individual waste, although various wastes were co-disposed of in actual landfills. This paper investigates the reduction of extraction-procedure toxicity by co-disposing various combinations of two wastes. When two wastes are mixed homogeneously, the extraction of heavy metals from the waste mixture is critically affected by the extract pH. Thus, co-disposal wastes will have a resultant pH between the pH values of its constituent. The lower the resultant pH, the lower the concentrations of heavy metals in the extract. When these wastes are extracted sequentially, the latter extracted waste has a stronger influence on the final concentration of heavy metals in the extract. Small-scale lysimeter experiments confirm that when heavy-metal-bearing leachates Generated from hazardous-waste lysimeters are passed through a nonhazardous-waste lysimeter filled with compost, briquette ash, or refuse-incineration ashes, the heavy-metal concentration in the final leachates decreases significantly. Thus, the heavy-metal leaching could be attenuated if a less extraction-procedure-toxic waste were placed at the bottom of a landfill. 3 refs., 4 figs., 5 tabs.

Septic systems as hot-spots of pollutants in the environment: Fate and mass balance of micropollutants in septic drainfields.

Science.gov (United States)

Yang, Yun-Ya; Toor, Gurpal S; Wilson, P Chris; Williams, Clinton F

2016-10-01

Septic systems, a common type of onsite wastewater treatment systems, can be an important source of micropollutants in the environment. We investigated the fate and mass balance of 17 micropollutants, including wastewater markers, hormones, pharmaceuticals and personal care products (PPCPs) in the drainfield of a septic system. Drainfields were replicated in lysimeters (1.5m length, 0.9m width, 0.9m height) and managed similar to the field practice. In each lysimeter, a drip line dispersed 9L of septic tank effluent (STE) per day (equivalent to 32.29L/m(2) per day). Fourteen micropollutants in the STE and 12 in the leachate from drainfields were detected over eight months. Concentrations of most micropollutants in the leachate were low (85% of the added micropollutants except for sucralose were attenuated in the drainfield. We discovered that sorption was the key mechanism for retention of carbamazepine and partially for sulfamethoxazole, whereas microbial degradation likely attenuated acetaminophen in the drainfield. This data suggests that sorption and microbial degradation limited transport of micropollutants from the drainfields. However, the leaching of small amounts of micropollutants indicate that septic systems are hot-spots of micropollutants in the environment and a better understanding of micropollutants in septic systems is needed to protect groundwater quality. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigation of defect-induced abnormal body current in fin field-effect-transistors

International Nuclear Information System (INIS)

Liu, Kuan-Ju; Tsai, Jyun-Yu; Lu, Ying-Hsin; Liu, Xi-Wen; Chang, Ting-Chang; Chen, Ching-En; Yang, Ren-Ya; Cheng, Osbert; Huang, Cheng-Tung

2015-01-01

This letter investigates the mechanism of abnormal body current at the linear region in n-channel high-k/metal gate stack fin field effect transistors. Unlike body current, which is generated by impact ionization at high drain voltages, abnormal body current was found to increase with decreasing drain voltages. Notably, the unusual body leakage only occurs in three-dimensional structure devices. Based on measurements under different operation conditions, the abnormal body current can be attributed to fin surface defect-induced leakage current, and the mechanism is electron tunneling to the fin via the defects, resulting in holes left at the body terminal

Integrated geophysical investigations in the Hisar geothermal field, Demirci, western Turkey

Energy Technology Data Exchange (ETDEWEB)

OEzuerlan, Guelcin [Istanbul Technical University, Maslak, Istanbul (Turkey). Faculty of Mines, Geophysical Engineering Department; Sahin, M. Huedavendigar [Department of Geophysics, General Directorate of Mineral Research and Exploration (MTA), Ankara (Turkey)

2006-04-15

The shallow, low-temperature geothermal field of Hisar, in western Turkey, was studied by means of vertical electrical sounding (VES), Wenner, self-potential (SP) and very low-frequency electromagnetic (VLF-EM) profiling surveys. The VES survey, conducted along the valley in an E-W direction, provided lithological and structural information that is in good agreement with the well data, and suggests that the field is characterized by low-resistivity values (=30Om). Because the resistivity structure in a N-S direction could not be investigated due to the rough topography towards the north, SP, Wenner and VLF-EM measurements were made to identify and characterize a possible hot-fluid carrying fault/fracture zone that forms one of the boundaries of the valley. There is a good correlation between the results of the SP, VLF-EM and Wenner surveys, which confirm the existence of the NE-SW striking fault zone that had been inferred from geologic information. Tensional fractures that developed perpendicular to the fault zone were also identified. Consistent with the results of the SP and Wenner profilings, the two-dimensional model derived from VLF-EM data and a Karous-Hjelt current density pseudo-section detected the conductive fault zones bearing the geothermal fluids. (author)

Evaluation of small scale laboratory and pot experiments to determine realistic transfer factors for the radionuclides Sr-90, Cs-137, Co-60 and Mn-54

International Nuclear Information System (INIS)

Steffens, W.; Fuhr, F.; Mittelstaedt, W.

1980-01-01

Lysimeter experiments were undertaken in a controlled experimental field to study the root uptake of Sr-90, Cs-137, Co-60 and Mn-54 under outdoor conditions. Parallel experiments were set up using the Kick - Brauckman experimental pots under greenhouse and the Neubauer cups under growth chamber conditions. The results obtained from the three types of experiments are compared. (H.K.)

Cycling of grain legume residue nitrogen

DEFF Research Database (Denmark)

Jensen, E.S.

1995-01-01

Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initial...... management methods in order to conserve grain legume residue N sources within the soil-plant system....

Experimental measurement and modeling of snow accumulation and snowmelt in a mountain microcatchment

Science.gov (United States)

Danko, Michal; Krajčí, Pavel; Hlavčo, Jozef; Kostka, Zdeněk; Holko, Ladislav

2016-04-01

Fieldwork is a very useful source of data in all geosciences. This naturally applies also to the snow hydrology. Snow accumulation and snowmelt are spatially very heterogeneous especially in non-forested, mountain environments. Direct field measurements provide the most accurate information about it. Quantification and understanding of processes, that cause these spatial differences are crucial in prediction and modelling of runoff volumes in spring snowmelt period. This study presents possibilities of detailed measurement and modeling of snow cover characteristics in a mountain experimental microcatchment located in northern part of Slovakia in Western Tatra mountains. Catchment area is 0.059 km2 and mean altitude is 1500 m a.s.l. Measurement network consists of 27 snow poles, 3 small snow lysimeters, discharge measurement device and standard automatic weather station. Snow depth and snow water equivalent (SWE) were measured twice a month near the snow poles. These measurements were used to estimate spatial differences in accumulation of SWE. Snowmelt outflow was measured by small snow lysimeters. Measurements were performed in winter 2014/2015. Snow water equivalent variability was very high in such a small area. Differences between particular measuring points reached 600 mm in time of maximum SWE. The results indicated good performance of a snow lysimeter in case of snowmelt timing identification. Increase of snowmelt measured by the snow lysimeter had the same timing as increase in discharge at catchment's outlet and the same timing as the increase in air temperature above the freezing point. Measured data were afterwards used in distributed rainfall-runoff model MIKE-SHE. Several methods were used for spatial distribution of precipitation and snow water equivalent. The model was able to simulate snow water equivalent and snowmelt timing in daily step reasonably well. Simulated discharges were slightly overestimated in later spring.

Seasonal Snowpack Dynamics and Runoff in a Maritime Forested Basin, Niigata, Japan

Science.gov (United States)

Whitaker, A. C.; Sugiyama, H.

2005-12-01

Seasonal snowpack dynamics are described through field measurements under contrasting canopy conditions for a mountainous catchment in the Japan Sea region. Microclimatic data, snow accumulation, albedo and lysimeter runoff is given through three complete winter seasons 2002-05 in: (1) mature cedar stand, (2) larch stand, and (3) regenerating cedar stand or opening. The accumulation and melt of seasonal snowpack strongly influences streamflow runoff during December to May, including winter base-flow, mid-winter melt, rain-on-snow, and diurnal peaks driven by radiation melt in spring. Lysimeter runoff at all sites is characterised by constant ground melt of 0.8-1.0 mm/day. Rapid response to mid-winter melt or rainfall shows that the snowpack remains in a ripe or near-ripe condition throughout the snowcover season. Hourly and daily lysimeter discharge was greatest during rain-on-snow with the majority of runoff due to rainfall passing through the snowpack as opposed to snowmelt. For both rain-on-snow and radiation melt events lysimeter discharge was generally greatest at the open site, although there were exceptions such as during interception melt events. During radiation melt instantaneous discharge was up to 4.0 times greater in the opening compared to the mature cedar, and 48-hour discharge was up to 2.5 times greater. Perhaps characteristic of maritime climates, forest interception melt is shown to be important in addition to sublimation in reducing snow accumulation beneath dense canopies. While sublimation represents a loss from the catchment water balance, interception melt percolates through the snowpack and contributes to soil moisture during the winter season. Strong differences in microclimate and snowpack albedo persisted between cedar, larch and open sites, and it is suggested further work is needed to account for this in hydrological simulation models.

Effect of temperature on Acoustic Evaluation of standing trees and logs: Part 2: Field Investigation

Science.gov (United States)

Shan Gao; Xiping Wang; Lihai Wang; R. Bruce Allison

2013-01-01

The objectives of this study were to investigate the effect of seasonal temperature changes on acoustic velocity measured on standing trees and green logs and to develop models for compensating temperature differences because acoustic measurements are performed in different climates and seasons. Field testing was conducted on 20 red pine (Pinus resinosa...

Aespoe hard rock laboratory. Field investigation methodology and instruments used in the preinvestigation phase, 1986-1990

International Nuclear Information System (INIS)

Almen, K.E.; Zellman, O.

1991-12-01

The Aespoe hard rock laboratory project started in 1986. The pre-investigation phase, 1986-1990, involved extensive field measurements from the surface as well as from boreholes, aimed at characterizing the rock formation with regard to geology, geohydrology, hydrochemistry and rock mechanics. The field investigation methodology used in the project was based on experience from and developments during the previous SKB study site investigation programme. However, in some respects the techniques were changed or modified. Major changes have been possible due to a new drilling technique, telescope-type drilling. This report describes the logistics of the investigation programme, characterized to a large extent by multi-purpose planning and performance of the activities in order to optimize the use of available resources; time, personnel and equipment. Preliminary hydraulic testing and groundwater sampling were conducted during the drilling of each borehole. When the drilling was completed an extensive set of singlehole investigations were carried out: geophysical logging, borehole radar, hydraulic tests of different kinds, water sampling and rock stress measurements. Multipackers were installed in the boreholes as soon as possible after the borehole investigations. The system enables monitoring of groundwater pressure, water sampling and groundwater flow measurements to be performed by means of dilution tests and tracer injection. Boreholes with such equipment were used as observation holes during interference pumping tests and long term hydraulic and tracer tests. The monitoring programme will continue during the subsequent phases of construction and operation of the Aespoe hard rock laboratory. (83 refs., 94 figs.) (au)

Fruit load governs transpiration of olive trees

NARCIS (Netherlands)

Bustan, Amnon; Dag, Arnon; Yermiyahu, Uri; Erel, Ran; Presnov, Eugene; Agam, Nurit; Kool, Dilia; Iwema, Joost; Zipori, Isaac; Ben-Gal, Alon

2016-01-01

We tested the hypothesis that whole-tree water consumption of olives (Olea europaea L.) is fruit load-dependent and investigated the driving physiological mechanisms. Fruit load was manipulated in mature olives grown in weighing-drainage lysimeters. Fruit was thinned or entirely removed from

Field investigation of skid resistance degradation of asphalt pavement during early service

Directory of Open Access Journals (Sweden)

Yinghao Miao

2016-07-01

Full Text Available This paper documents a field investigation into the skid resistance degradation of asphalt pavement during early service. Field tests were conducted 7 times during more than 2 years. There are 2 highway sections included in the field tests, which cover 4 asphalt surface types, i.e., dense asphalt concrete (DAC, rubber asphalt concrete (RAC, stone matrix asphalt (SMA, and ultra-thin wearing course (UTWC. Macrotexture and friction data were collected using the sand patch method and the dynamic friction tester respectively. The degradation of the mean texture depth (MTD and the friction coefficient at slip speed of 60 km/h (DFT60 were analyzed. The international friction index (IFI was also calculated using the friction coefficient at slip speed of 20 km/h (DFT20 with MTD to evaluate the skid resistance degradation. The UTWC has relatively good skid resistance even after 7.4 × 106 standard vehicle passes. The SMA has very stable friction performance which maintains almost the same friction level after 4.61 × 106 standard vehicle passes. The DAC and RAC have relatively poor friction performance while the RAC has better macrotexture. The changing trends of skid resistance with traffic wear can be fitted by a logarithmic model for all surface types. The SMA and UTWC have relatively clear relationship between DFT20 and MTD, while the RAC and the DAC show more complex. Keywords: Asphalt pavement, Skid resistance, Degradation, International friction index

An investigation of the performance of a coaxial HPGe detector operating in a magnetic resonance imaging field

Energy Technology Data Exchange (ETDEWEB)

Harkness, L.J., E-mail: ljh@ns.ph.liv.ac.u [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Boston, A.J.; Boston, H.C.; Cole, P.; Cresswell, J.R.; Filmer, F.; Jones, M.; Judson, D.S.; Nolan, P.J.; Oxley, D.C.; Sampson, J.A.; Scraggs, D.P.; Slee, M.J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Bimson, W.E.; Kemp, G.J. [MARIARC, University of Liverpool, Liverpool L69 3GE (United Kingdom); Groves, J.; Headspith, J.; Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Cooper, R.J. [Joint Institute for Heavy Ion Research, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6371 (United States)

2011-05-11

Nuclear medical imaging modalities such as positron emission tomography and single photon emission computed tomography are used to probe physiological functions of the body by detecting gamma rays emitted from biologically targeted radiopharmaceuticals. A system which is capable of simultaneous data acquisition for nuclear medical imaging and magnetic resonance imaging is highly sought after by the medical imaging community. Such a device could provide a more complete medical insight into the functions of the body within a well-defined structural context. However, acquiring simultaneous nuclear/MRI sequences are technically challenging due to the conventional photomultiplier tube readout employed by most existing scintillator detector systems. A promising solution is a nuclear imaging device composed of semiconductor detectors that can be operated with a standard MRI scanner. However, the influence of placing a semiconductor detector such as high purity germanium (HPGe) within or close to the bore of an MRI scanner, where high magnetic fields are present, is not well understood. In this paper, the performance of a HPGe detector operating in a high strength static (B{sub S}) MRI field along with fast switching gradient fields and radiofrequency from the MRI system has been assessed. The influence of the B{sub S} field on the energy resolution of the detector has been investigated for various positions and orientations of the detector within the magnetic field. The results have then been interpreted in terms of the influence of the B{sub S} field on the charge collection properties. MRI images have been acquired with the detector situated at the entrance of the MRI bore to investigate the effects of simultaneous data acquisition on detector performance and MRI imaging.

Investigating the sensitivity of PMMA optical fibres for use as an evanescent field absorption sensor in aqueous solutions

International Nuclear Information System (INIS)

Lye, P G; Boerkamp, M; Ernest, A; Lamb, D W

2005-01-01

Polymethylmethacrylate (PMMA) optical fibres are low-cost polymer fibres that are generally more physically robust than silica fibres, are more flexible, yet like silica fibres have the potential to be used for practical evanescent field absorption sensors in aqueous solutions. However, evanescent field absorption in aqueous solutions is influenced by more than just the specific absorptivity of the solution in question. The physical configuration of the optical fibre itself, as well as surface charge interactions between the fibre and the chromophore in the solution also significantly affects the sensitivity of the fibre to evanescent field absorption. This paper reports on an investigation of numerous physical phenomena that influence evanescent field absorption for PMMA fibres using an aqueous solution of the dye Amidoblack. Parameters investigated included fibre coiling configuration and bend radius, fibre interaction length, and effect of solution pH. Coiled fibres were found to be more sensitive to evanescent field absorption than straight (uncoiled) lengths, and sensitivity was found to increase with a further reduction in bend radius. At high solution pH, the absorption versus solution concentration proved to be linear whereas at low pH the absorption versus concentration relationship exhibited a clear deviation from linearity. The observed nonlinearity at low pH points to the importance of accounting for electrostatic interactions between chromophore and fibre surface when designing a PMMA sensor for evanescent field absorption measurements in aqueous solutions

Investigation of Polarization Phase Difference Related to Forest Fields Characterizations

Science.gov (United States)

Majidi, M.; Maghsoudi, Y.

2013-09-01

The information content of Synthetic Aperture Radar (SAR) data significantly included in the radiometric polarization channels, hence polarimetric SAR data should be analyzed in relation with target structure. The importance of the phase difference between two co-polarized scattered signals due to the possible association between the biophysical parameters and the measured Polarization Phase Difference (PPD) statistics of the backscattered signal recorded components has been recognized in geophysical remote sensing. This paper examines two Radarsat-2 images statistics of the phase difference to describe the feasibility of relationship with the physical properties of scattering targets and tries to understand relevance of PPD statistics with various types of forest fields. As well as variation of incidence angle due to affecting on PPD statistics is investigated. The experimental forest pieces that are used in this research are characterized white pine (Pinus strobus L.), red pine (Pinus resinosa Ait.), jack pine (Pinus banksiana Lamb.), white spruce (Picea glauca (Moench Voss), black spruce (Picea mariana (Mill) B.S.P.), poplar (Populus L.), red oak (Quercus rubra L.) , aspen and ground vegetation. The experimental results show that despite of biophysical parameters have a wide diversity, PPD statistics are almost the same. Forest fields distributions as distributed targets have close to zero means regardless of the incidence angle. Also, The PPD distribution are function of both target and sensor parameters, but for more appropriate examination related to PPD statistics the observations should made in the leaf-off season or in bands with lower frequencies.

INVESTIGATION OF POLARIZATION PHASE DIFFERENCE RELATED TO FOREST FIELDS CHARACTERIZATIONS

Directory of Open Access Journals (Sweden)

M. Majidi

2013-09-01

Full Text Available The information content of Synthetic Aperture Radar (SAR data significantly included in the radiometric polarization channels, hence polarimetric SAR data should be analyzed in relation with target structure. The importance of the phase difference between two co-polarized scattered signals due to the possible association between the biophysical parameters and the measured Polarization Phase Difference (PPD statistics of the backscattered signal recorded components has been recognized in geophysical remote sensing. This paper examines two Radarsat-2 images statistics of the phase difference to describe the feasibility of relationship with the physical properties of scattering targets and tries to understand relevance of PPD statistics with various types of forest fields. As well as variation of incidence angle due to affecting on PPD statistics is investigated. The experimental forest pieces that are used in this research are characterized white pine (Pinus strobus L., red pine (Pinus resinosa Ait., jack pine (Pinus banksiana Lamb., white spruce (Picea glauca (Moench Voss, black spruce (Picea mariana (Mill B.S.P., poplar (Populus L., red oak (Quercus rubra L. , aspen and ground vegetation. The experimental results show that despite of biophysical parameters have a wide diversity, PPD statistics are almost the same. Forest fields distributions as distributed targets have close to zero means regardless of the incidence angle. Also, The PPD distribution are function of both target and sensor parameters, but for more appropriate examination related to PPD statistics the observations should made in the leaf-off season or in bands with lower frequencies.

77 FR 16852 - Notice of Reclassification of Five Regional Offices to Investigative Field Offices: Seattle, WA...

Science.gov (United States)

2012-03-22

... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No. FR-5627-N-01] Notice of Reclassification of Five Regional Offices to Investigative Field Offices: Seattle, WA; New Orleans, LA; Baltimore, MD... legislative history of section 7(p) strongly suggests that the legislation is inapplicable to a...

Investigations of solutions of Einstein's field equations close to {lambda}-Taub-NUT

Energy Technology Data Exchange (ETDEWEB)

Beyer, Florian [KTH Matematik, 10044 Stockholm (Sweden)], E-mail: fbeyer@math.kth.se

2008-12-07

We present investigations of a class of solutions of Einstein's field equations close to the family of {lambda}-Taub-NUT spacetimes. The studies are done using a numerical code introduced by the author elsewhere. One of the main technical complications is due to the paragraph -topology of the Cauchy surfaces. Complementing these numerical results with heuristic arguments, we are able to yield some first insights into the strong cosmic censorship issue and the conjectures by Belinskii, Khalatnikov and Lifschitz in this class of spacetimes. In particular, the current investigations suggest that strong cosmic censorship holds in this class. We further identify open issues in our current approach and point to future research projects.

Apparatus for ground water chemistry investigations in field caissons

International Nuclear Information System (INIS)

Cokal, E.J.; Stallings, E.; Walker, R.; Nyhan, J.W.; Polzer, W.L.; Essington, E.H.

1985-01-01

Los Alamos is currently in its second season of ground water chemistry and hydrology experimentation in a field facility that incorporates clusters of six, 3-meter-diameter by 6-meter-deep, soil-filled caissons and required ancillaries. Initial experience gained during the 1983 field season indicated the need for further development of the technology of this type of experimentation supporting hydrologic waste management research. Uniform field application of water/matrix solutions to the caisson, matrix and tracer solution blending/storage, and devices for ground water sampling are discussed

An investigation of methods for neutron dose measurement in high temperature irradiation fields

Energy Technology Data Exchange (ETDEWEB)

Kosako, Toshisou; Sugiura, Nobuyuki [Tokyo Univ. (Japan); Kudo, Kazuhiko [Kyushu Univ., Fukuoka (Japan)] [and others

2000-10-01

The Japan Atomic Energy Research Institute (JAERI) has been conducting the innovative basic research on high temperature since 1994, which is a series of high temperature irradiation studies using the High Temperature Engineering Test Reactor (HTTR). 'The Task Group for Evaluation of Irradiation Dose under High Temperature Radiation' was founded in the HTTR Utilization Research Committee, which is the promoting body of the innovative basic research. The present report is a summary of investigation which has been made by the Task Group on the present status and subjects of research and development of neutron detectors in high temperature irradiation fields, in view of contributing to high temperature irradiation research using the HTTR. Detectors investigated here in the domestic survey are the following five kinds of in-core detectors: 1) small fission counter, 2) small fission chamber, 3) self-powered detector, 4) activation detector, and 5) optical fiber. In addition, the research and development status in Russia has been investigated. The present report will also be useful as nuclear instrumentation of high temperature gas-cooled reactors. (author)

Investigation of well redevelopment techniques for the MWD Well Field, Savannah River Site, South Carolina

International Nuclear Information System (INIS)

Kroening, D.E.; Snipes, D.S.; Falta, R.W.; Benson, S.M.

1994-01-01

Clemson University, in cooperation with the Savannah River Site (SRS) is investigating well treatment techniques at the Mixed Waste Disposal (MWD) Well Field at SRS. This well field consists of fifteen wells screened in three aquifers with a downward trending head gradient. Based on aquifer performance tests of the MWD wells, it has been determined that many of the wells exhibit low well efficiencies and high skin factors, indicative of damaged wells. Bacterial investigations show that the biological activity in these wells is low, probably due to a high pH environment. Evaluation of the Calcite Saturation Index for each well indicates that nearly all of the MWD wells have the potential for precipitating calcite and calcite deposits have been observed on downhole equipment. The calcite deposits may occur due to the dissolution of the grout mixtures by waters infiltrating down the well annulus driven by the downward head gradient with subsequent precipitation of calcite in the higher pH sand pack. Well rehabilitation techniques currently under investigation include acidification, hydraulic fracturing and traditional physical methods. In addition to treating the wells at MWD, the authors plan to perform aquifer performance tests and evaluate post-treatment skin factors. Further research into the long term effects of well treatment will be conducted, focusing on long term chemical changes brought about by the treatments

Experimental investigation of ion cyclotron range of frequencies heating scenarios for ITER's half-field hydrogen phase performed in JET

NARCIS (Netherlands)

Lerche, E.; Van Eester, D.; Johnson, T. J.; Hellsten, T.; Ongena, J.; Mayoral, M. L.; Frigione, D.; Sozzi, C.; Calabro, G.; Lennholm, M.; Beaumont, P.; Blackman, T.; Brennan, D.; Brett, A.; Cecconello, M.; Coffey, I.; Coyne, A.; Crombe, K.; Czarnecka, A.; Felton, R.; Giroud, C.; Gorini, G.; Hellesen, C.; Jacquet, P.; Kiptily, V.; Knipe, S.; Krasilnikov, A.; Maslov, M.; Monakhov, I.; Noble, C.; Nocente, M.; Pangioni, L.; Proverbio, I.; Sergienko, G.; Stamp, M.; Studholme, W.; Tardocchi, M.; Vdovin, V.; Versloot, T.; Voitsekhovitch, I.; Whitehurst, A.; Wooldridge, E.; Zoita, V.; JET-EFDA Contributors,

2012-01-01

Two ion cyclotron range of frequencies (ICRF) heating schemes proposed for the half-field operation phase of ITER in hydrogen plasmas—fundamental H majority and second harmonic 3 He ICRF heating—were recently investigated in JET. Although the same magnetic field and RF frequencies ( f ≈ 42 MHz and f

Experimental investigations of the neutron contamination in high-energy photon fields at medical linear accelerators

Energy Technology Data Exchange (ETDEWEB)

Brunckhorst, Elin

2009-02-26

The scope of this thesis was to develop a device for the detection of the photoneutron dose inside the high-energy photon field. The photoneutron contamination of a Siemens PRIMUS linear accelerator was investigated in detail in its 15 MV photon mode. The experimental examinations were performed with three ionisation chambers (a tissue equivalent chamber, a magnesium chamber and a {sup 10}B-coated magnesium chamber) and two types of thermoluminescence detectors (enriched with {sup 6}Li and {sup 7}Li, respectively). The detectors have different sensitivities to photons and neutrons and their combination allows the dose separation in a mixed neutron/photon field. The application of the ionisation chamber system, as well as the present TLD system for photoneutron detection in high-energy photon beams is a new approach. The TLD neutron sensitivity was found to be too low for a measurement inside the open photon field and the further investigation focused on the ionisation chambers. The three ionisation chambers were calibrated at different photon and neutron sources and a the borated magnesium chamber showed a very high response to thermal neutrons. For a cross check of the calibration, the three chambers were also used for dose separation of a boron neutron capture therapy beam where the exact determination of the thermal neutron dose is essential. Very accurate results were achieved for the thermal neutron dose component. At the linear accelerator the chamber system was reduced to a paired chamber system utilising the two magnesium chambers, since the fast neutron component was to small to be separated. The neutron calibration of the three chambers could not be applied, instead a conversion of measured thermal neutron signal by the borated chamber to Monte Carlo simulated total neutron dose was performed. Measurements for open fields in solid water and liquid water were performed with the paired chamber system. In larger depths the neutron dose could be determined

Experimental investigations of the neutron contamination in high-energy photon fields at medical linear accelerators

International Nuclear Information System (INIS)

Brunckhorst, Elin

2009-01-01

The scope of this thesis was to develop a device for the detection of the photoneutron dose inside the high-energy photon field. The photoneutron contamination of a Siemens PRIMUS linear accelerator was investigated in detail in its 15 MV photon mode. The experimental examinations were performed with three ionisation chambers (a tissue equivalent chamber, a magnesium chamber and a 10 B-coated magnesium chamber) and two types of thermoluminescence detectors (enriched with 6 Li and 7 Li, respectively). The detectors have different sensitivities to photons and neutrons and their combination allows the dose separation in a mixed neutron/photon field. The application of the ionisation chamber system, as well as the present TLD system for photoneutron detection in high-energy photon beams is a new approach. The TLD neutron sensitivity was found to be too low for a measurement inside the open photon field and the further investigation focused on the ionisation chambers. The three ionisation chambers were calibrated at different photon and neutron sources and a the borated magnesium chamber showed a very high response to thermal neutrons. For a cross check of the calibration, the three chambers were also used for dose separation of a boron neutron capture therapy beam where the exact determination of the thermal neutron dose is essential. Very accurate results were achieved for the thermal neutron dose component. At the linear accelerator the chamber system was reduced to a paired chamber system utilising the two magnesium chambers, since the fast neutron component was to small to be separated. The neutron calibration of the three chambers could not be applied, instead a conversion of measured thermal neutron signal by the borated chamber to Monte Carlo simulated total neutron dose was performed. Measurements for open fields in solid water and liquid water were performed with the paired chamber system. In larger depths the neutron dose could be determined with an

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

Numerical investigation of the contraction of neutral-charged diblock copolymer brushes in electric fields

International Nuclear Information System (INIS)

Chen, Yuwei; Li, Haiming; Zhu, Yuejin; Tong, Chaohui

2016-01-01

Using self-consistent field theory (SCFT), the contraction of neutral-charged A-B diblock copolymer brushes in electric fields generated by opposite surface charges on two parallel electrodes has been numerically investigated. The diblock copolymer chains were grafted with the free end of the neutral block to one electrode and immersed in a salt-free solution sandwiched between the two electrodes. The numerical results reveal that the charged monomers, A-B joint segment and the tail exhibit bimodal distributions under external electric fields, which are absent for homopolymer polyelectrolyte brushes. The dependences of the relative populations and peak positions of the two modes on various parameters such as block ratio, grafting density, chain length and strength of the applied electric field were systematically examined and the underlining mechanisms were elucidated. It was found in this study that, if the total amount of surface charges on the grafting electrode is no more than that of the counter-ions in the system, overall charge neutrality is generally maintained inside the brushes when including the contribution of surface charges on the grafting electrode. In such a case, the counter-ions expelled from the brushes are highly enriched in the immediate vicinity of the second electrode and an approximate charge balance between these expelled counter-ions and the opposite surface charges on the second electrode is achieved. (paper)

Migration barrier covers for radioactive and mixed waste landfills

International Nuclear Information System (INIS)

Hakonson, T.E.; Manies, K.L.; Warren, R.W.; Bostick, K.V.; Trujillo, G.; Kent, J.S.

1993-01-01

Migration barrier cover technology will likely serve as the remediation alternative of choice for most of DOE's radioactive and mixed waste landfills simply because human and ecological risks can be effectively managed without the use of more expensive alternatives. However, very little testing and evaluation has been done, either before or after installation, to monitor how effective they are in isolating waste or to develop data that can be used to evaluate model predictions of long term performance. Los Alamos National Laboratory has investigated the performance of a variety of landfill capping alternatives since 1981 using large field lysimeters to monitor the fate of precipitation falling on the cap surface. The objective of these studies is to provide the risk manager with a variety of field tested capping designs, of various complexities and costs, so that design alternatives can be matched to the need for hydrologic control at the site. Four different landfill cap designs, representing different complexities and costs, were constructed at Hill Air Force Base (AFB) in October and November, 1989. The designs were constructed in large lysimeters and instrumented to provide estimates of all components of water balance including precipitation, runoff (and soil erosion), infiltration, leachate production, evapotranspiration, and capillary/hydraulic barrier flow. The designs consisted of a typical soil cover to serve as a baseline, a modified EPA RCRA cover, and two versions of a Los Alamos design that contained erosion control measures, an improved vegetation cover to enhance evapotranspiration, and a capillary barrier to divert downward flow of soil water. A comprehensive summary of the Hill AFB demonstration will be available in October 1993, when the project is scheduled to terminate

Investigation of field emission properties of laser irradiated tungsten

International Nuclear Information System (INIS)

Akram, Mahreen; Bashir, Shazia; Hayat, Asma; Mahmood, Khaliq; Jalil, Sohail Abdul; Rafique, Muhammad Shahid

2018-01-01

Nd:YAG laser irradiation of Tungsten (W) has been performed in air at atmospheric pressure for four laser fluences ranging from 130 to 500 J/cm 2 . Scanning electron microscope analysis revealed the formation of micro and nanoscale surface features including cones, grains, mounds and pores. Field emission (FE) studies have been performed in a planar diode configuration under ultra-high vacuum conditions by recording I-V characteristics and plotting corresponding electric field (E) versus emission current density (J). The Fowler-Nordheim (FN) plots are found to be linear confirming the quantum mechanical tunneling phenomena for the structured targets. The irradiated samples at different fluences exhibit a turn-on field, field enhancement factor β and a maximum current density ranging from 5 to 8.5 V/μm, 1300 to 3490 and 107 to 350 μA/cm 2 , respectively. The difference in the FE properties is attributed to the variation in the nature and density of the grown structures at different fluences. (orig.)

An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes

International Nuclear Information System (INIS)

Ainsbury, Elizabeth A; Conein, Emma; Henshaw, Denis L

2005-01-01

Elliptically polarized magnetic fields induce higher currents in the body compared with their plane polarized counterparts. This investigation examines the degree of vector ellipticity of extremely low frequency magnetic fields (ELF-MFs) in the home, with regard to the adverse health effects reportedly associated with ELF-MFs, for instance childhood leukaemia. Tri-axial measurements of the magnitude and phase of the 0-3000 Hz magnetic fields, produced by 226 domestic mains-fed appliances of 32 different types, were carried out in 16 homes in Worcestershire in the summer of 2004. Magnetic field strengths were low, with average (RMS) values of 0.03 ± 0.02 μT across all residences. In contrast, background field ellipticities were high, on average 47 ± 11%. Microwave and electric ovens produced the highest ellipticities: mean respective values of 21 ± 21% and 21 ± 17% were observed 20 cm away from these appliances. There was a negative correlation between field strength and field polarization, which we attribute to the higher relative field contribution close to each individual (single-phase) appliance. The measurements demonstrate that domestic magnetic fields are extremely complex and cannot simply be characterized by traditional measurements such as time-weighted average or peak exposure levels. We conclude that ellipticity should become a relevant metric for future epidemiological studies of health and ELF-MF exposure

Investigation of optical nanostructures for photovoltaics with near-field scanning microscopy; Untersuchung optischer Nanostrukturen fuer die Photovoltaik mit Nahfeldmikroskopie

Energy Technology Data Exchange (ETDEWEB)

Beckers, Thomas

2011-09-26

Textured and rough surfaces are known to increase light trapping in solar cells significantly. The development and optimization of these nano-structures is essential to improve the energy conversion efficiency of thin-film solar cells. In the past, first research approaches covered classical and macroscopic investigations, e.g. determining the haze or angularly resolved scattering. These methods do not provide precise explanation for the optical improvement of the devices, because layer thicknesses and structure sizes in thin-film solar cells are smaller than the wavelength of visible light. The impact of local nano-structures and their contribution to the local absorption enhancement is not resolved by macroscopic measurements. In this thesis, near-field scanning optical microscopy is introduced as first near-field investigations of nano-structures for photovoltaics. This provides an insight into local optical effects for relevant surfaces of photovoltaic devices. Investigating the distribution of the electric fields in layer stacks is crucial to understand the absorption in solar cells. Evanescent fields, which occur due to total internal reflection at the interfaces, are measurable by near-field scanning optical microscopy and yield important information about local light trapping. Within the framework of this thesis, correlations between local surface structures and optical near-field effects are shown. In this case structure features of randomly textured surfaces, which optimize local light trapping, are identified. It paves the way to connect microscopic optical effects on the surface with the macroscopic performance of thin-film solar cells. Moreover, the measurement yields a 3D illustration of the electric field distribution over the sample surface. It is an important criterion to prove the results of rigorous diffraction theory. An excellent agreement between experiment and simulation is found. The simulations provide an insight into the material, which is

The behavior of a type-II superconductor Nb in a magnetic field as investigated in polarized-neutron transmission experiments

International Nuclear Information System (INIS)

Aksenov, V.L.; Dokukin, E.B.; Kozhevnikov, S.V.; Nikitenko, Yu.V.; Petrenko, A.V.

1995-01-01

The type-II superconducting polycrystal Nb was investigated on the SPN-1 polarized-neutron spectrometer at the high-intensity pulsed reactor IBR-2 at Dubna. In polarized-neutron transmission experiments the magnetic-field dependence of the neutron beam polarization was measured. Experiments were performed over a wide magnetic-field range from 0 to H c2 at a temperature of 4.8 K. A quasiperiodic variation of the neutron depolarization as a function of magnetic-field strength was observed. (orig.)

Investigation of a natural geochemical barrier

International Nuclear Information System (INIS)

1991-02-01

Groundwater data from lysimeters and monitor wells in the vicinity of the Bowman, North Dakota, Uranium Mill Tailings Remedial Action (UMTRA) Project site indicated that there is a mechanism in the subsurface which cleans up downward-percolating fluids. It was hypothesized that clays and organic materials in the sediments sequestered hazardous constituents from infiltrating fluids. A program was designed to collect sediment cores from various locations on and around the site and to analyze the sediments to determine whether there has been a build up of hazardous constituents in any specific type of sedimentary material. Materials that concentrate the hazardous constituents would be potential candidates to be used in constructed geochemical barriers. The water quality of the groundwater contained within the sedimentary section indicates that there is a transport of contaminants down through the sediments and that these contaminants are removed from solution by the iron-bearing minerals in the organic-rich lignite beds. The data gathered during the course of this investigation indicate that the lignite ashing operations have added very little of the hazardous constituents of concern--arsenic, chromium, molybdenum, selenium, or uranium--to the sediments beneath the UMTRA Project site. At both locations, the hazardous constituents are concentrated in the upper most lignite bed. These data offer a natural analog for laboratory tests in which sphagnum peat was used to sequester hazardous constituents. Constructed geochemical barriers are a viable mechanism for the clean-up of the majority of hazardous constituents from uranium mill tailings in groundwater

Investigations on magnetic field induced optical transparency in magnetic nanofluids

Science.gov (United States)

Mohapatra, Dillip Kumar; Philip, John

2018-02-01

We study the magnetic field induced optical transparency and its origin in magnetic nanoemulsion of droplets of average size ∼200 nm containing superparamagnetic iron oxide nanoparticles. Beyond a certain volume fraction (Φ > 0.0021) of magnetic nanoemulsion and a critical magnetic field (Hc1), the transmitted light intensity increases drastically and reaches a maximum at another critical magnetic field (Hc2), beyond which the transmitted light intensity decreases and reaches a plateau. Interestingly, the transmitted light intensity at Hc2 is found to increase linearly with Φ and the critical magnetic fields Hc1 and Hc2 follow power law decay with Φ (i.e. Hc ∼ Φ-x), with exponents 0.48 and 0.27, respectively. The light intensity recovers to its initial value when the magnetic field is switched off, indicating the perfect reversibility of the field induced transparency process. The observed straight line scattered patterns above Hc2, on a screen placed perpendicular to the incident beam, confirms the formation of rod like anisotropic nanostructures perpendicular to the direction of light propagation. The magneto-optical measurements in the emulsion confirm that the observed field induced transparency in magnetic emulsions for Φ > 0.0021 is due to the optical birefringence caused by the rod like nanostructures. The reduced birefringence is found to be proportional to the square of the applied magnetic field. This finding offers several possibilities in using magnetic nanofluids in tunable optical devices.

Investigation of high-current low pressure quasistationary volume discharge in cross-field ExH

International Nuclear Information System (INIS)

Bashutin, O.A.; Vovchenko, E.D.; Kirnev, G.S.

1995-01-01

Different types of high current discharge permitted to create large volume of high density homogeneous plasma are widely used in modern technique. Such discharges are applied as plasma emitters of charged particles and also in various technologies for sputtering, implantation and etching of materials. The results of a plasma electron density dynamics investigation of low pressure quasistationary volume discharge in cross-field E x H is described in this paper. The discharge was created in a quadrupole magnetic system with special form electrodes and has following characteristics current up to 1,8 kA, voltage on the interval 80-120 V, existence time up to 1,5 ms. The discharge conserves diffusive character of plasma and cathode layer on all current range. On a first research stage plasma parameters of discharge were determined by means of Langmuir probe, that could been used in central discharge region only, where magnetic field was equal to zero. An obtained plasma density was reached 1,5*10 15 cm -3 with electron temperature T e =10 eV. The research of discharge plasma in regions with magnetic field had required to use interferometric measurement technique

Numerical investigation of the heat transfer of a ferrofluid inside a tube in the presence of a non-uniform magnetic field

Science.gov (United States)

Hariri, Saman; Mokhtari, Mojtaba; Gerdroodbary, M. Barzegar; Fallah, Keivan

2017-02-01

In this article, a three-dimensional numerical investigation is performed to study the effect of a magnetic field on a ferrofluid inside a tube. This study comprehensively analyzes the influence of a non-uniform magnetic field in the heat transfer of a tube while a ferrofluid (water with 0.86 vol% nanoparticles (Fe3O4) is let flow. The SIMPLEC algorithm is used for obtaining the flow and heat transfer inside the tube. The influence of various parameters, such as concentration of nanoparticles, intensity of the magnetic field, wire distance and Reynolds number, on the heat transfer is investigated. According to the obtained results, the presence of a non-uniform magnetic field significantly increases the Nusselt number (more than 300%) inside the tube. Also, the magnetic field induced by the parallel wire affects the average velocity of the ferrofluid and forms two strong eddies in the tube. Our findings show that the diffusion also raises as the concentration of the nanoparticle is increased.

Limited field investigation report for the 100-HR-1 Operable Unit

International Nuclear Information System (INIS)

1994-08-01

This limited field investigation (LFI) report summarizes the data collection and analysis activities conducted during the 100-HR-1 Source Operable Unit LFI and the associated qualitative risk assessment (QRA) (WHC 1993a), and makes recommendations on the continued candidacy of high-priority sites for interim remedial measures (IRM). The results and recommendations presented in this report are generally independent of future land use scenarios. A LFI Report is required, in accordance with the HPPS, when waste sites are to be considered for IRMs. The LFI is an integral part of the remedial investigation/feasibility study (RI/FS) or Resource Conservation and Recovery Act (RCRA) facility investigation/corrective measures study (RFI/CMS) and process and functions as a focused RI or RFI for selection of IRMs. The purpose of the report is to identify those sites that are recommended to remain as candidates for IRMs, provide a preliminary summary of site characterization studies, refine the conceptual model as needed, identify contaminant- and location-specific applicable or relevant and appropriate requirements (ARA), and provide a qualitative assessment of the risks associated with the sites. This assessment includes consideration of whether contaminant concentrations pose an unacceptable risk that warrants action through IRMs. The 100-HR-1 unit encompasses approximately 100 acres adjacent to the Columbia River shoreline. It contains waste units associated with the original plant facilities constructed to support the H Reactor. The area also contains evaporation basins which received liquid process wastes and nonroutine deposits of chemical wastes from the 300 Area, where fuel elements for the N Reactor were produced

[Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio]. Volume 4, Health and Safety Plan (HSP); Phase 1, Task 4 Field Investigation report: Draft

Energy Technology Data Exchange (ETDEWEB)

1991-10-01

This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

Limited field investigation report for the 100-KR-4 Operable Unit

International Nuclear Information System (INIS)

1994-07-01

This limited field investigation (LFI) was conducted to optimize the use of interim remedial measures (IRM) for expediting clean up while maintaining a technically sound and cost-effective program. The 100-KR-4 Operable Unit is one of four operable units associated with the 100 K Area. Operable units KR-1, KR-2 and KR-3 address contaminant sources while 100-KR-4 addresses contamination present in the underlying groundwater. The IRM decision process for groundwater operable units is based on three aspects: (1) Is the concentration greater than Hanford background? (2) Does the concentration present a medium or high human-health risk? (3) Does the concentration exceed an ecologically based applicable, relevant and appropriate requirements (ARAR) or present an environmental hazard quotient > I? The primary methods of investigation used during this LFI were the installation of monitoring wells and sampling of groundwater. The samples collected from the groundwater and soils were submitted for laboratory analysis. Boreholes were surveyed for radiological contamination using downhole geophysical techniques to further delineate the location and degree of contamination. All soil samples were screened to ascertain the presence of volatile organic compounds and radionuclides. Analytical data were subjected to validation; all first round and a minimum of 10% of subsequent round data were validated

Dynamics of Nutrients Transport in Onsite Wastewater Treatment Systems

Science.gov (United States)

Toor, G.; De, M.

2013-05-01

Domestic wastewater is abundant in nutrients¬ that originate from various activities in the households. In developed countries, wastewater is largely managed by (1) centralized treatment where wastewater from large population is collected, treated, and discharged and (2) onsite treatment where wastewater is collected from an individual house, treated, and dispersed onsite; this system is commonly known as septic system or onsite wastewater treatment system (OWTS) and consist of a septic tank (collects wastewater) and drain-field (disperses wastewater in soil). In areas with porous sandy soils, the transport of nutrients from drain-field to shallow groundwater is accelerated. To overcome this limitation, elevated disposal fields (commonly called mounds) on top of the natural soil are constructed to provide unsaturated conditions for wastewater treatment. Our objective was to study the dynamics of nitrogen (N) and phosphorus (P) transport in the vadose zone and groundwater in traditional and advanced OWTS. Soil water samples were collected from the vadose zone by using suction cup lysimeters and groundwater samples were collected by using piezometers. Collected samples (wastewater, soil-water, groundwater) were analyzed for various water quality parameters. The pH (4.39-4.78) and EC (0.28-0.34 dS/m) of groundwater was much lower than both wastewater and soil-water. In contrast to >50 mg/L of ammonium-N in wastewater, concentrations in all lysimeters (0.02-0.81 mg/L) and piezometers (0.01-0.82 mg/L) were 99% disappeared (primarily nitrified) in the vadose zone (20 mg/L in the vadose zones of traditional systems (drip dispersal and gravel trench). Concentrations of chloride showed a distinct pattern of nitrate-N breakthrough in vadose zone and groundwater; the groundwater nitrate-N was elevated upto 19.2 mg/L after wastewater delivery in tradional systems. Total P in the wastewater was ~10 mg/L, but low in all lysimeters (0.046-1.72 mg/L) and piezometers (0.01-0.78 mg

A Strategy to Conduct an Analysis of the Long-Term Performance of Low-Activity Waste Glass in a Shallow Subsurface Disposal System at Hanford

Energy Technology Data Exchange (ETDEWEB)

BP McGrail, WL Ebert, DH Bacon, DM Strachan

1998-02-18

Privatized services are being procured to vitrify low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. Over 500,000 metric tons of low-activity waste glass will be generated, which is among the largest volumes of waste within the U.S. Department of Energy (DOE) complex and is one of the largest inventories of long-lived radionuclides planned for disposal in a low-level waste facility. Before immobilized waste can be disposed, DOE must approve a "performance assessment," which is a document that describes the impacts of the disposal facility on public health and environmental resources. Because the release rate of radionuclides from the glass waste form is a key factor determining these impacts, a sound scientific basis for determining their long-term release rates must be developed if this disposal action is to be accepted by regulatory agencies, stakeholders, and the public. In part, the scientific basis is determined from a sound testing strategy. The foundation of the proposed testing strategy is a well accepted mechanistic model that is being used to calculate the glass corrosion behavior over the geologic time scales required for performance assessment. This model requires that six parameters be determined, and the testing program is defined by an appropriate set of laboratory experiments to determine these parameters, and is combined with a set of field experiments to validate the model as a whole. Three general classes of laboratory tests are proposed in this strategy: 1) characterization, 2) accelerated, and 3) service condition. Characterization tests isolate and provide specific information about processes or parameters in theoretical models. Accelerated tests investigate corrosion behavior that will be important over the regulated service life of a disposal system within a laboratory time frame of a few years or less. Service condition tests verify that the techniques used in accelerated tests do not change

Theoretical investigation of field-line quality in a driven spheromak

International Nuclear Information System (INIS)

Cohen, R.H.; Cohen, B.I.; Berk, H.L.

2003-01-01

Theoretical studies aimed at predicting and diagnosing field-line quality in a spheromak are described. These include nonlinear 3-D MHD simulations, stability studies, analyses of confinement in spheromaks dominated by either open (stochastic) field lines or approximate flux surfaces, and a theory of fast electrons as a probe of field-line length. (author)

A multidisciplinary approach of workload assessment in real-job situations: Investigation in the field of aerospace activities

Directory of Open Access Journals (Sweden)

Claudine eMélan

2014-09-01

Full Text Available The present contribution presents two field studies combining tools and methods from cognitive psychology and from occupational psychology in order to perform a thorough investigation of workload in employees. Cognitive load theory proposes to distinguish different load categories of working memory, in a context of instruction. Intrinsic load is inherent to the task, extraneous load refers to components of a learning environment that may be modified to reduce total load, and germane load enables schemas construction and thus efficient learning. We showed previously that this theoretical framework may be successfully extended to working memory tasks in non instructional designs. Other theoretical models, issued from the field of occupational psychology, account for an individual’s perception of work demands or requirements in the context of different psychosocial features of the (work environment. Combining these approaches is difficult as workload assessment by job-perception questionnaires explore an individual’s overall job-perception over a large time-period, whereas cognitive load investigations in working memory tasks are typically performed within short time-periods. We proposed an original methodology enabling investigation of workload and load factors in a comparable time-frame. We report two field studies investigating workload on different shift-phases and between work-shifts, with two custom-made tools. The first one enabled workload assessment by manipulating intrinsic load (task difficulty and extraneous load (time pressure in a working-memory task. The second tool was a questionnaire based on the theoretical concepts of work-demands, control and psychosocial support. Two additional dimensions suspected to contribute to job-perception, i.e. work-family conflicts and availability of human and technical resources were also explored. Results of workload assessments were discussed in light of operators’ alertness and job-performance.

A multidisciplinary approach of workload assessment in real-job situations: investigation in the field of aerospace activities.

Science.gov (United States)

Mélan, Claudine; Cascino, Nadine

2014-01-01

The present contribution presents two field studies combining tools and methods from cognitive psychology and from occupational psychology in order to perform a thorough investigation of workload in employees. Cognitive load theory proposes to distinguish different load categories of working memory, in a context of instruction. Intrinsic load is inherent to the task, extraneous load refers to components of a learning environment that may be modified to reduce total load, and germane load enables schemas construction and thus efficient learning. We showed previously that this theoretical framework may be successfully extended to working memory tasks in non-instructional designs. Other theoretical models, issued from the field of occupational psychology, account for an individual's perception of work demands or requirements in the context of different psychosocial features of the (work) environment. Combining these approaches is difficult as workload assessment by job-perception questionnaires explore an individual's overall job-perception over a large time-period, whereas cognitive load investigations in working memory tasks are typically performed within short time-periods. We proposed an original methodology enabling investigation of workload and load factors in a comparable time-frame. We report two field studies investigating workload on different shift-phases and between work-shifts, with two custom-made tools. The first one enabled workload assessment by manipulating intrinsic load (task difficulty) and extraneous load (time pressure) in a working-memory task. The second tool was a questionnaire based on the theoretical concepts of work-demands, control, and psychosocial support. Two additional dimensions suspected to contribute to job-perception, i.e., work-family conflicts and availability of human and technical resources were also explored. Results of workload assessments were discussed in light of operators' alertness and job-performance.

Investigation on seasonal variation of thermal-induced strain in flexible pavements based on field and laboratory measurements

Directory of Open Access Journals (Sweden)

Simita Biswas

2016-09-01

Full Text Available Pavement temperature variation has a large influence on the structural response of flexible pavements. Daily and seasonal temperature fluctuation causes expansion and contraction of pavement material, which then leads to the generation of thermal strain. In this study, field observation and laboratory tests were conducted to investigate seasonal variation of thermal-induced strain in flexible pavement. Field observations were conducted at the Integrated Road Research Facility (IRRF’s test road in Edmonton, Alberta, Canada, which is fully equipped with structural and environmental monitoring instruments. The main objective of the field study was to compare the variation of thermal-induced strain in warm and cold seasons. Field results indicated that thermal-induced strain is 1.4–2.0 times greater in cold seasons than in warm seasons following the same pavement temperature variations; however, strain generation rate was greater in warm seasons. Laboratory testing of asphalt slab and cylindrical samples produced comparable ratios. Moreover, field observation and laboratory testing showed a similar trend of temperature and thermal strain variations. Keywords: Thermal-induced strain, Asphalt strain gauge, Field observation, Flexible pavement, Laboratory testing, Seasonal variation

Perturbation electric fields and disturbance currents investigated during the 25 September 1998 great storm

Science.gov (United States)

Horvath, Ildiko; Lovell, Brian C.

2014-10-01

This study investigates the ionosphere's response to the 25 September 1998 great storm and utilizes multi-instrument observations covering the Australian (140°E; geographic) and Indian (75°E) longitude sectors. Results show the domination of eastward (westward) electrojet at 140°E (75°E). Its causative net eastward (westward) perturbation electric (E) field drove the forward (reverse) plasma fountain, caused the presence (absence) of the equatorial ionization anomaly (EIA). These strong longitudinal differences were due to a combination of various LT-dependent, E field-driven, and competing mechanisms. Perturbation E fields are identified as prompt penetration E field (PPEF) and disturbance dynamo E field (DDEF). Due to the later (earlier) local time at 140°E (75°E), the undershielding PPEF was eastward (westward) directed early in the main phase. A series of periodic substorms occurred during the recovery phase. The substorm-related eastward PPEFs became overpowered by westward DDEFs over India but remained dominant in the Australian sector. Thus, eastward PPEFs (westward DDEFs) dominated at 140°E (75°E). At 140°E these eastward PPEFs exhibited a strong positive correlation with the variations of both the cross polar cap potential drop and the asymmetric ring current, significantly increased the net equatorial upward E × B drift and thus caused EIA development with plasma bubbles scintillating GPS signals. Based on the strong and independent correlation of these asymmetric ring current events with both the EIA development and the scintillation activity, we propose that the ASY-H index could provide a natural tool for modeling EIA development and scintillation episodes during severe storms characterized by periodic substorm-related eastward PPEFs.

Influences of clinoptilolite and surfactant-modified clinoptilolite zeolite on nitrate leaching and plant growth

International Nuclear Information System (INIS)

Malekian, Raheleh; Abedi-Koupai, Jahangir; Eslamian, Sayed Saeid

2011-01-01

The increasing demands for environmental protection and sustainable food production require an increase in the use of natural and non-toxic materials for agriculture. In this study, the feasibility of using surfactant-modified zeolite (SMZ) in comparison with zeolite clinoptilolite (Cp) application to reduce nitrate leaching and enhance crop growth was investigated. The effects of size (millimeter and nanometer) and application rate (20 g kg -1 and 60 g kg -1 ) of Cp and SMZ on nitrate leaching and crop response were also evaluated. Using soil lysimeters, it was determined that the maximum and mean nitrate concentration in the leachate of SMZ-amended soil were significantly (p 3 -N leached from SMZ- and Cp-amended lysimeters at the higher application rate (60 g kg -1 ) was approximately 26% and 22% lower, respectively, than that from the control system. The mean grain yield, grain nitrogen content, stover dry matter, and N uptake were significantly greater in Cp-amended than SMZ-amended lysimeters. There was no significant effect due to the particle size of the two soil amendments. The results implicitly suggest that plants may have a better response if Cp is used as a fertilizer carrier rather than SMZ when applied at a rate of 60 g kg -1 .

Numerical investigation of renormalization group equations in a model of vector field advected by anisotropic stochastic environment

International Nuclear Information System (INIS)

Busa, J.; Ajryan, Eh.A.; Jurcisinova, E.; Jurcisin, M.; Remecky, R.

2009-01-01

Using the field-theoretic renormalization group, the influence of strong uniaxial small-scale anisotropy on the stability of inertial-range scaling regimes in a model of passive transverse vector field advected by an incompressible turbulent flow is investigated. The velocity field is taken to have a Gaussian statistics with zero mean and defined noise with finite time correlations. It is shown that the inertial-range scaling regimes are given by the existence of infrared stable fixed points of the corresponding renormalization group equations with some angle integrals. The analysis of integrals is given. The problem is solved numerically and the borderline spatial dimension d e (1,3] below which the stability of the scaling regime is not present is found as a function of anisotropy parameters

Investigation on the optimal magnetic field of a cusp electron gun for a W-band gyro-TWA

Science.gov (United States)

Zhang, Liang; He, Wenlong; Donaldson, Craig R.; Cross, Adrian W.

2018-05-01

High efficiency and broadband operation of a gyrotron traveling wave amplifier (gyro-TWA) require a high-quality electron beam with low-velocity spreads. The beam velocity spreads are mainly due to the differences of the electric and magnetic fields that the electrons withstand the electron gun. This paper investigates the possibility to decouple the design of electron gun geometry and the magnet system while still achieving optimal results, through a case study of designing a cusp electron gun for a W-band gyro-TWA. A global multiple-objective optimization routing was used to optimize the electron gun geometry for different predefined magnetic field profiles individually. Their results were compared and the properties of the required magnetic field profile are summarized.

Investigations of Flare Gas Emissions in Taq Taq Oil Field on the Surrounding Land

Directory of Open Access Journals (Sweden)

Jafar A. Ali

2014-11-01

Full Text Available Environmental pollution caused by oil takes many different forms; one of the most damaging sources is simply the combustion of oil products, such as a well flare burn-off. This paper presents the results of a survey of the agriculture lands around the Taq Taq Oil Production Company. The aim of the survey was to determine the potential contamination caused by the gas emissions from the well flares. Taq Taq field is located in the Kurdistan Region of Iraq, 60 km north of the giant Kirkuk oil field, 85 km south-east of Erbil and 120 km north-west of Suleimani. Samples of soil were collected from several locations around the site and analyzed to determine the content of Polycyclic Aromatic Hydrocarbons PAH present. A gas chromatography linked to a mass spectrometry (GCMS machine was used for these measurements. The PAH contamination at each location of soil was determined and the 16-PAHs, as listed in the US Environmental Protection Agency (EPA documentation were investigated. The average content of total PAH in all samples of the agricultural soil was 0.654 mg·kg-1 with the concentrations ranging from 0.310 to 0.869 mg·kg-1. It was found that the PAH concentrations decreased with increasing distance from the TTOPCO oil field, indicating that pollution was evident, the area close to the field being more affected by the gas pollution.

Investigating excitation-dependent and fringe-field effects of electromagnet and permanent-magnet phase shifters for a crossed undulator

Energy Technology Data Exchange (ETDEWEB)

Chung, Ting-Yi, E-mail: chung.albert@nsrrc.org.tw [National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Yang, Chih-Sheng; Chu, Yun-Liang; Lin, Fu-Yuan; Jan, Jyh-Chyuan [National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Hwang, Ching-Shiang [National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Department of Electrophysics, National Chiao Tung University, Hsinchu 30050, Taiwan (China)

2017-04-01

To enhance the flux density or to control polarization, a phase shifter was designed and used to modulate the phase matching between segmented undulators. A larger hysteresis loop causes, however, a repeatability issue in the phase matching; the fringe field of the phase shifter creates an extra magnetic-field error. The design of the phase shifter must therefore minimize the hysteresis loop and fringe field to maintain the phases exact and to ignore the crosstalk effect. Two critical issues are the hysteresis-loop problem and the fringe-field effect, which determine the radiation performance and the stability of the ring. To investigate these issues, a phase shifter was constructed to operate in accordance with electromagnetic- and permanent-type magnets; the results from the field measurements and shims are discussed here. The shimming algorithm and a compact permanent-magnet phase shifter that eliminates the issues are also presented.

An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes

Science.gov (United States)

Ainsbury, Elizabeth A.; Conein, Emma; Henshaw, Denis L.

2005-07-01

Elliptically polarized magnetic fields induce higher currents in the body compared with their plane polarized counterparts. This investigation examines the degree of vector ellipticity of extremely low frequency magnetic fields (ELF-MFs) in the home, with regard to the adverse health effects reportedly associated with ELF-MFs, for instance childhood leukaemia. Tri-axial measurements of the magnitude and phase of the 0-3000 Hz magnetic fields, produced by 226 domestic mains-fed appliances of 32 different types, were carried out in 16 homes in Worcestershire in the summer of 2004. Magnetic field strengths were low, with average (RMS) values of 0.03 ± 0.02 µT across all residences. In contrast, background field ellipticities were high, on average 47 ± 11%. Microwave and electric ovens produced the highest ellipticities: mean respective values of 21 ± 21% and 21 ± 17% were observed 20 cm away from these appliances. There was a negative correlation between field strength and field polarization, which we attribute to the higher relative field contribution close to each individual (single-phase) appliance. The measurements demonstrate that domestic magnetic fields are extremely complex and cannot simply be characterized by traditional measurements such as time-weighted average or peak exposure levels. We conclude that ellipticity should become a relevant metric for future epidemiological studies of health and ELF-MF exposure. This work is supported by the charity CHILDREN with LEUKAEMIA, registered charity number 298405.

Geological investigation of hydrothermal alteration haloes in Toyoha geothermal field, Hakkaido

Energy Technology Data Exchange (ETDEWEB)

Igarashi, T; Furukawa, Y; Sugawara, K; Nishimura, S; Okabe, K

1978-01-01

In Toyoha geothermal field, the altered haloes are located along a tectonic line extending on a NW-SE direction along the Yunosawa River, east of the Toyoha Mine, a well known Neogene epithermal ore deposit. The investigation was carried out to clarify the stage of alteration, based on the altered haloes geologic structure, composition, and size. The Quaternary distribution at the eastern foot of Mt. Yotei was also studied. The field is covered by various kinds of Miocene sediments but the altered haloes are found only in an area covered by the Takinosawa formation and its older formations. Among the Yunosawa, Koyanagizawa and Takinosawa alteration haloes, the Yunosawa is the most important. It is composed of blocky silicified rock extending along a river and surrounding argillaceous rock. The silicified rock is composed primarily of quartz and subordinate alunite and opal, while the argillaceous rock consists chiefly of kaloin and is characterized by the occasional presence of sericite and montmorillinite. Fission-track and /sup 14/C methods were employed to determine the stage of alteration, but the results were unsatisfactory. The sublimation sulfur ore deposits in the Yunosawa and Koyanagizawa areas were comparatively small, but their original depositional features remain intact, indicating that geothermal activity continued until recently. Yunosawa is the most promising area as it is closely related to the tectonic line and also it has extraordinarily high ground temperature determined by a recent heat flow survey. Twenty-three references are provided.

Moessbauer investigation of magnetic hyperfine fields near bivalent Eu compounds under high pressure

International Nuclear Information System (INIS)

Abd Elmeguid, M.

1979-01-01

The paper deals with the pressure or volume dependence of hyperfine interactions of magnetically ordered, bivalent europium compounds. Emphasis is laid on the investigation of the pressure or volume dependence of magnetic hyperfine fields as they are found at the nuclear site of 151 Eu or of diamagnetic 119 Sn or 197 Au probe atoms. The measurements were carried out with the aid of the gamma resonance of 151 Eu (21.6 keV) 119 Sn (23.8 keV) and 167 Au (77.4 keV) at low temperatures and external pressures up to 65 kbar. (orig./WBU) [de

Quartz luminescence response to a mixed alpha-beta field: Investigations on Romanian loess

DEFF Research Database (Denmark)

Constantin, Daniela; Jain, Mayank; Murray, Andrew S.

2015-01-01

-OSL laboratory dose response curves do not reflect the growth of the OSL signal in nature. A main difference in coarse- and fine-grained quartz dating lies in the alpha irradiation history, but the effect of mixed alpha-beta fields has so far received little attention. In the present study we investigate whether...... the alpha dose experienced by fine grains over geological cycles of irradiation and bleaching may have an effect on the saturation characteristics of the laboratory dose response. By applying time resolved optically stimulated luminescence we confirm that the OSL signals induced in quartz by alpha and beta...

Ecological investigation of application of pesticides in rice fields

International Nuclear Information System (INIS)

Nouri, J.; Arjomandi, R.; Bayat, H.

2000-01-01

Among several pests of rice as one of the main agricultural products in Iran, rice borer, C hilo sarsaparilla is one of the most important pests of this crop. Use of pesticides coincided with the occurrence of this pest in the northern region of Iran in 1972. At present in order to control this pest, more than 12000 tones of pesticides granules are used annually. Ecological effects of pesticides application and the use of Trichograma sp. as a natural enemy, for assessing the impacts of pesticides in environments, especially on different living organisms on the plant, in irrigation water, and in 5 cm depth of surface soil, were investigated in two regions of Amol, named Osk. Mahalleh and Capik Field of Tashbandan. Results indicated that the two treatments were not different on crop loss. One the contrary, in the pesticide treatment, there was a considerable dec tease in the population of living organisms, particularly, no organism was observed in 5 cm depth of surface soil. It is recommended that in order to maintain the balance of environment, the use of chemicals for controlling rice borer must be with extreme care, only in the inevitable was with the use of principles of Integrated Pest Management

L'isotope stable 15N et le lysimètre, des outils complémentaires pour l'étude de la lixiviation de l'azote dans les sols agricoles

Directory of Open Access Journals (Sweden)

Destain JP.

2010-01-01

Full Text Available Stable 15N isotope and lysimeter, complementary tools in order to study the nitrogen leaching in agricultural soils. Stable 15N was used in lysimetric trials conducted with the aim to study nitrate leaching of agricultural soils. At Gembloux, a rate of 200 kg N.ha-1 as 15NH4 15NO3 with an isotopic abundance of 2.161 At%15N was applied in two lysimeters before a spinach crop, followed by beans and winter wheat; in the first lysimeter, total recovery by crops was less than 39.8% while in second lysimeter, recovery was 62.2%. Concentrations of N-NO3 - in leached water were always higher in lysimeter 2 than lysimeter 1, probably due to less microbial immobilization of nitrogen. At Remicourt and Omal, a simulated mineral residue of 150 kg N.ha-1 (rate of 15NH4 15NO3 applied in autumn has completely disappeared from the soil profile (0-90 cm already in July of the following year. At Omal, a winter crop has recovered no more than 9% of nitrogen rate applied in autumn. Measurement of N-NO3 - concentration in leached water has shown clearly higher levels at Remicourt (even more than 70 mg N.l-1 probably caused by an application of high rate of compost rich in nitrogen than is Omal. Stable 15N isotope could not be analyzed in leaching water probably due to a leak of sensitiveness of the analytical equipment.

Investigation of the validity of radiosity for sound-field prediction in cubic rooms

Science.gov (United States)

Nosal, Eva-Marie; Hodgson, Murray; Ashdown, Ian

2004-12-01

This paper explores acoustical (or time-dependent) radiosity using predictions made in four cubic enclosures. The methods and algorithms used are those presented in a previous paper by the same authors [Nosal, Hodgson, and Ashdown, J. Acoust. Soc. Am. 116(2), 970-980 (2004)]. First, the algorithm, methods, and conditions for convergence are investigated by comparison of numerous predictions for the four cubic enclosures. Here, variables and parameters used in the predictions are varied to explore the effect of absorption distribution, the necessary conditions for convergence of the numerical solution to the analytical solution, form-factor prediction methods, and the computational requirements. The predictions are also used to investigate the effect of absorption distribution on sound fields in cubic enclosures with diffusely reflecting boundaries. Acoustical radiosity is then compared to predictions made in the four enclosures by a ray-tracing model that can account for diffuse reflection. Comparisons are made of echograms, room-acoustical parameters, and discretized echograms. .

Development and Testing of UCLA's Electron Losses and Fields Investigation (ELFIN) Instrument Payload

Science.gov (United States)

Wilkins, C.; Bingley, L.; Angelopoulos, V.; Caron, R.; Cruce, P. R.; Chung, M.; Rowe, K.; Runov, A.; Liu, J.; Tsai, E.

2017-12-01

UCLA's Electron Losses and Fields Investigation (ELFIN) is a 3U+ CubeSat mission designed to study relativistic particle precipitation in Earth's polar regions from Low Earth Orbit. Upon its 2018 launch, ELFIN will aim to address an important open question in Space Physics: Are Electromagnetic Ion-Cyclotron (EMIC) waves the dominant source of pitch-angle scattering of high-energy radiation belt charged particles into Earth's atmosphere during storms and substorms? Previous studies have indicated these scattering events occur frequently during storms and substorms, and ELFIN will be the first mission to study this process in-situ.Paramount to ELFIN's success is its instrument suite consisting of an Energetic Particle Detector (EPD) and a Fluxgate Magnetometer (FGM). The EPD is comprised of two collimated solid-state detector stacks which will measure the incident flux of energetic electrons from 50 keV to 4 MeV and ions from 50 keV to 300 keV. The FGM is a 3-axis magnetic field sensor which will capture the local magnetic field and its variations at frequencies up to 5 Hz. The ELFIN spacecraft spins perpendicular to the geomagnetic field to provide 16 pitch-angle particle data sectors per revolution. Together these factors provide the capability to address the nature of radiation belt particle precipitation by pitch-angle scattering during storms and substorms.ELFIN's instrument development has progressed into the late Engineering Model (EM) phase and will soon enter Flight Model (FM) development. The instrument suite is currently being tested and calibrated at UCLA using a variety of methods including the use of radioactive sources and applied magnetics to simulate orbit conditions during spin sectoring. We present the methods and test results from instrument calibration and performance validation.

Dynamics of colloidal systems of magnetic nanoparticles under influence of magnetic fields investigated by XPCS

International Nuclear Information System (INIS)

Schavkan, Alexander

2017-05-01

This thesis investigates structural properties and the underlying microscopic dynamics of suspensions of α-FeOOH goethite platelets in water under the influence of magnetic fields. Goethite particles show unusual physical properties and a rich phase diagram, which makes their suspensions an object of high interest for research in the area of ''smart nanoparticles''. Five nanoparticle concentrations were chosen such that different liquid crystal phases could be studied. The suspensions of platelets of these chosen concentrations were exposed to magnetic fields of varying strength. Small angle X-ray scattering and X-ray photon correlation spectroscopy data were taken and evaluated. The appearing phases and phase transitions were studied as a function of concentration and applied magnetic field. For this purpose, order parameters, ellipticity, radial and azimuthal peak positions and widths of scattering features were investigated to clarify the structural properties in detail. For the analysis of the underlying dynamics, the relaxation rates and the shape of measured time correlation functions were evaluated. The results show that with increasing magnetic field a partial realignment of the platelets occurs. This realignment is connected to the magnetic properties of the particles. The dynamics of the corresponding phases revealed a dependence on the concentration of nanoparticles in the suspension. At a concentration of c=20 vol% the transition from the nematic to the anti-nematic phase traverses a mixed state. The nematic and anti-nematic phases show ballistic motion and very similar properties, even though a realignment of the particles from an orientation with the long axis parallel to the applied magnetic field in the nematic phase to an orientation with the long axis perpendicular to the magnetic field in the anti-nematic phase occurs. The mixed state of 20 vol%-suspension exhibits a diffusive motion of the particles and different characteristics. A significant

Dynamics of colloidal systems of magnetic nanoparticles under influence of magnetic fields investigated by XPCS

Energy Technology Data Exchange (ETDEWEB)

Schavkan, Alexander

2017-05-15

This thesis investigates structural properties and the underlying microscopic dynamics of suspensions of α-FeOOH goethite platelets in water under the influence of magnetic fields. Goethite particles show unusual physical properties and a rich phase diagram, which makes their suspensions an object of high interest for research in the area of ''smart nanoparticles''. Five nanoparticle concentrations were chosen such that different liquid crystal phases could be studied. The suspensions of platelets of these chosen concentrations were exposed to magnetic fields of varying strength. Small angle X-ray scattering and X-ray photon correlation spectroscopy data were taken and evaluated. The appearing phases and phase transitions were studied as a function of concentration and applied magnetic field. For this purpose, order parameters, ellipticity, radial and azimuthal peak positions and widths of scattering features were investigated to clarify the structural properties in detail. For the analysis of the underlying dynamics, the relaxation rates and the shape of measured time correlation functions were evaluated. The results show that with increasing magnetic field a partial realignment of the platelets occurs. This realignment is connected to the magnetic properties of the particles. The dynamics of the corresponding phases revealed a dependence on the concentration of nanoparticles in the suspension. At a concentration of c=20 vol% the transition from the nematic to the anti-nematic phase traverses a mixed state. The nematic and anti-nematic phases show ballistic motion and very similar properties, even though a realignment of the particles from an orientation with the long axis parallel to the applied magnetic field in the nematic phase to an orientation with the long axis perpendicular to the magnetic field in the anti-nematic phase occurs. The mixed state of 20 vol%-suspension exhibits a diffusive motion of the particles and different

Laboratory and field investigation of chemical disinfection of combined sewer overflow in Copenhagen area

DEFF Research Database (Denmark)

Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper

We investigated the possibility to apply performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA to Escherichia coli (E. coli) and enterococcus were studied in batch scale...... and pre-field experiment. In batch scale experiment 2.5 mg·L -1 PAA removed around 4 log unit of E. coli and enterococcus from CSO with long contact time. Removal of E. coli and enterococcus from CSO were always around or above 3 log unit using 2-4 mg·L -1 PFA with short contact time in batch scale...... and pre-field experiment. There were no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA, slight toxicological effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event. Disinfection...

Fate and Transport of Pharmaceutical Compounds Applied to Turf-Covered Soil

Science.gov (United States)

Young, M.; Green, R. L.; Devitt, D.; McCullough, M.; Wright, L.; Vanderford, B. J.; Snyder, S. A.

2012-12-01

In arid and semi-arid regions, the use of treated wastewater for landscape irrigation is becoming common practice and a significant asset to conserve potable water supplies. Public interest and lack of field-scale data are leading to a concern that compounds found in reuse water could persist in the environment and contaminate groundwater. As part of a larger study, 2-yr experiments were conducted in CA and NV, where reuse water was the primary source of non-ambient water input. A total of 13 compounds were studied, all originating in irrigation water applied to soil covered in turf or left bare. The target compounds included atenolol, atorvastatin, carbamazepine, diazepam, diclofenac, fluoxetine, gemfibrozil, ibuprofen, meprobamate, naproxen, primidone, sulfamethoxazole, triclosan, and trimethoprim. Analytical protocols for all compounds (detection at ng/L range) were established before the study commenced. The goals of the research were to increase available data on the fate and transport of these target compounds in turfgrass/soil systems, and to use these data to assess long-term risk from using water containing these compounds. Experiments conducted at two scales are discussed here: lysimeter-scale and field-scale. At the lysimeter-scale, 24 drainage lysimeters (120 cm thick) were exposed to treated wastewater as an irrigation source. Lysimeters varied by soil type (two types), soil cover (bare- versus turf-covered) and leaching fraction (5% and 25%). Upper and lower boundary conditions were monitored throughout the study. Water samples were collected periodically after water breakthrough. After the study, soil samples were analyzed for compound mass, allowing compound mass balance and removal to be assessed. At the field-scale, passive drain gages (Decagon Devices) were installed in triplicate in fairways at four operational golf courses, one in NV and three in CA, all with histories of using treated wastewater. The gages measure water fluxes through the 60

Evaluation of Upland Disposal of Oakland Harbor, California, Sediment; Volume I: Turning Basin Sediments

Science.gov (United States)

1992-10-01

infiltration studies ( Westerdahl and Skogerboe 1982). Extensive field 53 verification studies have been conducted with the WES Rainfall Simulator...Lysimeter System on a wide range of Corps project sites ( Westerdahl and Skogerboe 1982, Lee and Skogerboe 1984, Skogerboe et al. 1987). The WES Rain- fall...Vicksburg, MS. Winer, B. J. 1971. Statistical Principles in Experimental Design, McGraw- Hill Book Company, New York. Westerdahl , H. E., and Skogerboe, J

New Bedford Harbor Superfund Project, Acushnet River Estuary Engineering Feasibility Study of Dredging and Dredged Material Disposal Alternatives. Report 4. Surface Runoff Quality Evaluation for Confined Disposal

Science.gov (United States)

1988-01-01

infiltration studies ( Westerdahl and Skogerboe 1982). Exten- sive field verification studies have been conducted with the WES Rainfall Simulator...Lysimeter System on a wide range of USACE project sites ( Westerdahl and Skogerboe 1982, Lee and Skogerboe 1984, Skogerboe et al. 1987). The WES Rainfall...Criteria for Water 1986,"’ Criteria and Standards Division, Washington, DC. Westerdahl , H. E., and Skogerboe, J. G. 1982. "Realistic Rainfall and Water

Partnership to Improve Nutrient Efficiency

Science.gov (United States)

PINE began in 2013 by working with OSU Extension and producers to locate and test existing 1990s lysimeters in Benton, Linn and Lane counties. The team identified additional producers to install Prenart lysimeters at a total of 15 sites. Producers allow for soil and water samplin...

Numerical investigation of a plasma beam entering transverse magnetic fields

International Nuclear Information System (INIS)

Koga, J.; Geary, J.L.; Tajima, T.; Rostoker, N.

1988-11-01

We study plasma beam injection into transverse magnetic fields using both electrostatic and electromagnetic particle-in-cell (PIC) codes. In the case of small beam momentum or energy (low drift kinetic /beta/) we study both large and small ion gyroradius beams. Large ion gyroradius beams with a large dielectric constant /epsilon/ /muchreverse arrowgt/ (M/m)/sup /1/2// are found to propagate across the magnetic field via E /times/ B drifts at nearly the initial injection velocity, where /epsilon/ = 1 + (/omega//sup pi//sup 2/)/(/Omega//sub i//sup 2/) and (M/m) is the ion to electron mass ratio. Beam degradation and undulations are observed in agreement with previous experimental and analytical results. When /epsilon/ is on the order of (M/m)/sup /1/2//, the plasma beam propagates across field lines at only half its initial velocity and loses its coherent structure. When /epsilon/ is much less than (M/m)/sup /1/2//, the beam particles decouple at the magnetic field boundary, scattering the electrons and slightly deflecting the ions. For small ion gyroradius beam injection a flute type instability is observed at the beam magnetic fields interface. In the case of large beam momentum or energy (high drift kinetic /beta/) we observe good penetration of a plasma beam which shields the magnetic field from the interior of the beam (diagmagnetism). 25 refs., 13 figs., 1 tab

Investigating the impact of visuohaptic simulations for the conceptual understanding of electric field for distributed charges

Science.gov (United States)

Shaikh, Uzma Abdul Sattar

The present study assessed the benefits of a multisensory intervention on the conceptual understanding of electric field for distributed charges in engineering and technology undergraduate students. A novel visuohaptic intervention was proposed, which focused on exploring the forces around the different electric field configurations for distributed charges namely point, infinitely long line and uniformly charged ring. The before and after effects of the visuohaptic intervention are compared, wherein the intervention includes instructional scaffolding. Three single-group studies were conducted to investigate the effect among three different populations: (a) Undergraduate engineering students, (b) Undergraduate technology students and (c) Undergraduate engineering technology students from a different demographic setting. The findings from the three studies suggests that the haptic modality intervention provides beneficial effects by allowing students to improve their conceptual understanding of electric field for distributed charges, although students from groups (b) and (c) showed a statistically significant increase in the conceptual understanding. The findings also indicate a positive learning perception among all the three groups.

Investigation of Corner Effect and Identification of Tunneling Regimes in L-Shaped Tunnel Field-Effect-Transistor.

Science.gov (United States)

Najam, Faraz; Yu, Yun Seop

2018-09-01

Corner-effect existing in L-shaped tunnel field-effect-transistor (LTFET) was investigated using numerical simulations and band diagram analysis. It was found that the corner-effect is caused by the convergence of electric field in the sharp source corner present in an LTFET, thereby increasing the electric field in the sharp source corner region. It was found that in the corner-effect region tunneling starts early, as a function of applied bias, as compared to the rest of the channel not affected by corner-effect. Further, different tunneling regimes as a function of applied bias were identified in the LTFET including source to channel and channel to channel tunneling regimes. Presence of different tunneling regimes in LTFET was analytically justified with a set of equations developed to model source to channel, and channel to channel tunneling currents. Drain-current-gate-voltage (Ids-Vgs) characteristics obtained from the equations is in reasonable qualitative agreement with numerical simulation.

Overview of NASA Finesse (Field Investigations to Enable Solar System Science and Exploration) Science and Exploration Project

Science.gov (United States)

Heldmann, J. L.; Lim, D.S.S.; Hughes, S.; Nawotniak, S. Kobs; Garry, B.; Sears, D.; Neish, C.; Osinski, G. R.; Hodges, K.; Downs, M.;

Investigation of Interaction between Deferoxamine and Low Frequency Electromagnetic Field on Angiogenesis in Chick Embryo

Directory of Open Access Journals (Sweden)

Atena Dashtizadeh

2015-02-01

Full Text Available Background: Deferoxamine (DFO is an iron chelator. In the present research, the synergic effects of deferoxamine and electromagnetic field (with 50 H frequency and 100 Gauss intensity on angiogenesis of chick chorioallantoic membrane were investigated. Materials and Methods: In this experimental study 80 fertilized egg used and randomly divided 8 group: control group, laboratory control groups of 1 and 2, experimental group 1 (treatment with electromagnetic field, 2 and 3 (treatment with deferoxamine 10, 100 µmol, respectively, 4 and 5 (treatment both deferoxamine 10 and 100 µmol respectively and electromagnetic field. On 8th day of incubation, 2 and 4 groups were incubated with 10 µL deferoxamine and for 3 and 5 groups were incubated with 10 µL deferoxamine 100 µmol. On 10th day, 1, 4 and 5 groups were put in electromagnetic field. On 12th day, the number and length of vessels in all samples was measured by Image J software. Data were analyzed by SPSS-19, ANOVA and t-test. Results: The mean number and length of vessels in the control and experimental cases did not show any significant differences. Comparison between mean number of vessels in the control and group 2, 3, 4, 5 showed a significant decrease (p<0.05 and groups 2 and 4 was showed a significant decrease in the mean length of vessels compared with the controls (p<0.05. Conclusion: Using deferoxamine with low frequency electromagnetic field (50 Hz and 100 G cause inhibition of angiogenesis in chick embryo chorioallantoic membrane.

A Comparison of Soil-Water Sampling Techniques

Science.gov (United States)

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

2007-12-01

The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot identify the soil volume from which a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods to determine what portion of soil pore water is sampled by each method. Intact soil cores (30 centimeter (cm) diameter by 40 cm height) were extracted from two different sites - a sandy soil near Altamonte Springs, Florida and a clayey soil near Centralia in Boone County, Missouri. Isotopically labeled water (O18? - analyzed by mass spectrometry) and bromide concentrations (KBr- - measured using ion chromatography) from water samples taken by suction lysimeters was compared with samples obtained by direct extraction methods of centrifugation and azeotropic distillation. Water samples collected by direct extraction were about 0.25 ? more negative (depleted) than that collected by suction lysimeter values from a sandy soil and about 2-7 ? more negative from a well structured clayey 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. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter should be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also indicate that each extraction method be use to sample a different

INVESTIGATION OF SECONDARY MIXED RADIATION FIELD AROUND A MEDICAL LINEAR ACCELERATOR.

Science.gov (United States)

Tulik, Piotr; Tulik, Monika; Maciak, Maciej; Golnik, Natalia; Kabat, Damian; Byrski, Tomasz; Lesiak, Jan

2017-09-29

The aim of this study is to investigate secondary mixed radiation field around linac, as the first part of an overall assessment of out-of-field contribution of neutron dose for new advanced radiation dose delivery techniques. All measurements were performed around Varian Clinic 2300 C/D accelerator at Maria Sklodowska-Curie Memorial, Cancer Center and Institute of Oncology, Krakow Branch. Recombination chambers REM-2 and GW2 were used for recombination index of radiation quality Q4 determination (as an estimate of quality factor Q), measurement of total tissue dose Dt and calculation of gamma and neutron components to Dt. Estimation of Dt and Q4 allowed for the ambient dose equivalent H*(10) per monitor unit (MU) calculations. Measurements around linac were performed on the height of the middle of the linac's head (three positions) and on the height of the linac's isocentre (five positions). Estimation of secondary radiation level was carried out for seven different configurations of upper and lower jaws position and multileaf collimator set open or closed in each position. Study includes the use of two photon beam modes: 6 and 18 MV. Spatial distribution of ambient dose equivalent H*(10) per MU on the height of the linac's head and on the standard couch height for patients during the routine treatment, as well as relative contribution of gamma and neutron secondary radiation inside treatment room were evaluated. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Experimental investigation of axial plasma injection into a magnetic dipole field

DEFF Research Database (Denmark)

Jensen, Vagn Orla

1968-01-01

A high-density helium plasma, accelerated from a conical pinch, is injected axially into a magnetic dipole field. Magnetic probe measurements show that, near the axis, a compression of the field is super-imposed on the standard diamagnetic depression. The compression starts downstream and moves t...... towards the injector. Simultaneously with the compression, an increase in the electron temperature and reflection of a small amount of plasma are seen. The amount of plasma transmitted through the dipole field is found to be nearly independent of the field strength.......A high-density helium plasma, accelerated from a conical pinch, is injected axially into a magnetic dipole field. Magnetic probe measurements show that, near the axis, a compression of the field is super-imposed on the standard diamagnetic depression. The compression starts downstream and moves...

Investigation of the velocity field in a full-scale model of a cerebral aneurysm

International Nuclear Information System (INIS)

Roloff, Christoph; Bordás, Róbert; Nickl, Rosa; Mátrai, Zsolt; Szaszák, Norbert; Szilárd, Szabó; Thévenin, Dominique

2013-01-01

Highlights: • We investigate flow fields inside a phantom model of a full-scale cerebral aneurysm. • An artificial blood fluid is used matching viscosity and density of real blood. • We present Particle Tracking results of fluorescent tracer particles. • Instantaneous model inlet velocity profiles and volume flow rates are derived. • Trajectory fields at three of six measurement planes are presented. -- Abstract: Due to improved and now widely used imaging methods in clinical surgery practise, detection of unruptured cerebral aneurysms becomes more and more frequent. For the selection and development of a low-risk and highly effective treatment option, the understanding of the involved hemodynamic mechanisms is of great importance. Computational Fluid Dynamics (CFD), in vivo angiographic imaging and in situ experimental investigations of flow behaviour are powerful tools which could deliver the needed information. Hence, the aim of this contribution is to experimentally characterise the flow in a full-scale phantom model of a realistic cerebral aneurysm. The acquired experimental data will then be used for a quantitative validation of companion numerical simulations. The experimental methodology relies on the large-field velocimetry technique PTV (Particle Tracking Velocimetry), processing high speed images of fluorescent tracer particles added to the flow of a blood-mimicking fluid. First, time-resolved planar PTV images were recorded at 4500 fps and processed by a complex, in-house algorithm. The resulting trajectories are used to identify Lagrangian flow structures, vortices and recirculation zones in two-dimensional measurement slices within the aneurysm sac. The instantaneous inlet velocity distribution, needed as boundary condition for the numerical simulations, has been measured with the same technique but using a higher frame rate of 20,000 fps in order to avoid ambiguous particle assignment. From this velocity distribution, the time

Investigation of Resonance Effect Caused by Local Exposure of Extremely Low Frequency Magnetic Field on Brain Signals: A Randomize Clinical Trial

Directory of Open Access Journals (Sweden)

Rasul Zadeh Tabataba’ei K

2011-03-01

Full Text Available Background and Objectives: Some studies have investigated the effects of extremely low frequency magnetic fields (ELF-MFs on brain signals, but only few of them have reported that humans exposed to magnetic fields exhibit changes in brain signals at the frequency of stimulation, i.e. resonance effect. In most investigations, researchers usually take advantage of a uniform field which encompasses the head. The aim of present study was to expose different parts of the brain to ELF-MFs locally and to investigate variation of brain signal and resonance effect.Methods: The subjects consisting of 19 male-students with the mean age of 25.6±1.6 years participated in this study. Local ELF-MFs with 3, 5, 10, 17 and 45Hz frequencies and 240 μT intensity was applied on five points (T3, T4, Cz, F3 and F4 of participants scalp Separately in 10-20 system. In the end, relative power over this points in common frequency bands and at the frequency of magnetic fields was evaluated by paired t-test.Results: Exposure of Central area by local magnetic field caused significant change (p<0.05 in the forehead alpha band. Reduction in the alpha band over central area was observed when temporal area was exposed to ELF MF.Conclusion: The results showed that resonance effect in the brain signals caused by local magnetic field exposure was not observed and change in every part of the relative power spectrum might occur. The changes in the EEG bands were not limited necessarily to the exposure point.

Investigation of mechanical field weakening of axial flux permanent magnet motor

Science.gov (United States)

Syaifuddin Mohd, M.; Aziz, A. Rashid A.; Syafiq Mohd, M.

2015-12-01

An investigation of axial flux permanent magnet motor (AFPM) characteristics was conducted with a proposed mechanical field weakening control mechanisms (by means of stator-rotor force manipulation) on the motor through modeling and experimentation. By varying the air gap between at least two bistable positions, the peak torque and top speed of the motor can be extended. The motor high efficiency region can also be extended to cover greater part of the motor operating points. An analytical model of the motor had been developed to study the correlation between the total attraction force (between the rotor and the stator) and the operating parameters of the motor. The test results shows that the motor output complies with the prediction of the research hypothesis and it is likely that a spring locking mechanism can be built to dynamically adjust the air gap of the motor to increase the operating range and could be applied in electric drivetrain applications to improve overall efficiency of electric and hybrid electric vehicles.

77 FR 16850 - Notice of Reclassification of One Investigative Field Office to Regional Office: Denver, CO

Science.gov (United States)

2012-03-22

...This notice advises the public that the HUD/OIG Office of Investigation plans to reclassify its Denver, Colorado field office as a regional office. The planned reorganization is intended to: 1. Improve the alignment of limited investigative resources, to promote more efficient responses to HUD or Congressional requests involving critical program issues; 2. Redeploy resources to prevent and detect fraud in new program delivery of CPD, FHA and other HUD programs; and 3. Improve management control and effectiveness, and reduce travel costs of management by reducing region size. 4. Return to the traditional Regional alignment of HUD OIG Regional offices and HUD Regional offices.

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

Rover-Based Instrumentation and Scientific Investigations During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

Science.gov (United States)

Graham, L. D.; Graff, T. G.

2013-01-01

Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) were recently completed on Mauna Kea Volcano, Hawaii. Scientific investigations, scientific input, and operational constraints were tested in the context of existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration [1]. Several investigations were conducted by the rover mounted instruments to determine key geophysical and geochemical properties of the site, as well as capture the geological context of the area and the samples investigated. The rover traverse and associated science investigations were conducted over a three day period on the southeast flank of the Mauna Kea Volcano, Hawaii. The test area was at an elevation of 11,500 feet and is known as "Apollo Valley" (Fig. 1). Here we report the integration and operation of the rover-mounted instruments, as well as the scientific investigations that were conducted.

Investigation of Physics Teacher Candidates' Cognitive Structures about "Electric Field": A Free Word Association Test Study

Science.gov (United States)

Türkkan, Ercan

2017-01-01

The aim of this study is to investigate the cognitive structures of physics teacher candidates about "electric field." Phenomenographic research method, one of the qualitative research patterns, was used in the study. The data of the study was collected from 91 physics teacher candidates who had taken General Physics II course at…

FIELD INVESTIGATION OF BIOLOGICAL TOILET SYSTEMS AND GREY WATER TREATMENT

Science.gov (United States)

The objective of the field program was to determine the operational characteristics and overall acceptability of popular models of biological toilets and a few select grey water systems. A field observation scheme was devised to take advantage of in-use sites throughout the State...

Phosphorus leaching from cow manure patches on soil columns

NARCIS (Netherlands)

Chardon, W.J.; Aalderink, G.H.; Salm, van der C.

2007-01-01

The loss of P in overland flow or leachate from manure patches can impair surface water quality. We studied leaching of P from 10-cmhigh lysimeters filled with intact grassland soil or with acid-washed sand. A manure patch was created on two grassland and two sandfilled lysimeters, and an additional

Investigations in thermal fields and stress fields induced by electron beam welding

International Nuclear Information System (INIS)

Basile, G.

1979-12-01

This document presents the thermal study of electron beam welding and identifies stresses and strains from welding: description of the operating principles of the electron gun and characterization of various welding parameters, examination of the temperature fields during electron beam welding development of various mathematic models and comparison with experimental results, measurement and calculation of stresses and strains in the medium plane of the welding assembly, residual stresses analysis [fr

Temperature field investigation of the industrial autoclave ASCAMAT-230

Directory of Open Access Journals (Sweden)

Stolyanov A. V.

2017-09-01

Full Text Available Heterogeneity of the temperature field in the sterilization chambers of industrial autoclaves during heating and cooling phase is one of the problems in the development of new regime for product heat treatment on the preliminary selection and laboratory testing stages. This is the reason of studying the temperature field of the industrial autoclave ASCAMAT-230. The autoclave ASCAMAT-230 is a vertical autoclave of 230 liters capacity heated by three tubular electric heaters. Determination of temperature field parameters has been carried out according to the method for studying the temperature field of periodic devices' heating medium for sterilizing canned food. Six Thermochron iButton temperature loggers have been used to measure the temperatures in the sterilization chamber of the ASCAMAT-230 autoclave. Logger 1 has been put in the place of the standard thermometer installation, loggers 2 and 3, 5 and 6 – in the center and on periphery of the lower and upper parts of the autoclave respectively, logger 4 – in the center of the middle part of the autoclave's sterilization chamber. Temperature measurement in cans with the product has been carried out by temperature loggers from the Ellab TrackSense PRO complex. The loggers have been installed in two cans with homogeneous product located in the upper and lower parts of the autoclave. The time temperature dependences for the entire sterilization process, as well as for the heating and cooling stages have been constructed according to the acquired information. Based on these data conclusions about the uniformity of the temperature field inside the sterilization chamber of the autoclave ASCAMAT-230 during the heating, sterilization and cooling stages have been developed. Some recommendations for using the autoclave ASCAMAT-230 in the preliminary selection and verification of sterilization regimes for canned foods from hydrobionts, and also for the creation of an industrial autoclave control system

Investigation on the hot melting temperature field simulation of HDPE water supply pipeline in gymnasium pool

Science.gov (United States)

Cai, Zhiqiang; Dai, Hongbin; Fu, Xibin

2018-06-01

In view of the special needs of the water supply and drainage system of swimming pool in gymnasium, the correlation of high density polyethylene (HDPE) pipe and the temperature field distribution during welding was investigated. It showed that the temperature field distribution has significant influence on the quality of welding. Moreover, the mechanical properties of the welded joint were analyzed by the bending test of the weld joint, and the micro-structure of the welded joint was evaluated by scanning electron microscope (SEM). The one-dimensional unsteady heat transfer model of polyethylene pipe welding joints was established by MARC. The temperature field distribution during welding process was simulated, and the temperature field changes during welding were also detected and compared by the thermo-couple temperature automatic acquisition system. Results indicated that the temperature of the end surface of the pipe does not reach the maximum value, when it is at the end of welding heating. Instead, it reaches the maximum value at 300 sand latent heat occurs during the welding process. It concludes that the weld quality is the highest when the welding pressure is 0.2 MPa, and the heating temperature of HDPE heat fusion welding is in the range of 210 °C-230 °C.

Stud arc welding in a magnetic field – Investigation of the influences on the arc motion

International Nuclear Information System (INIS)

Hartz-Behrend, K; Forster, G; Schein, J; Marqués, J L; Jenicek, A; Müller, M; Cramer, H; Jilg, A; Soyer, H

2014-01-01

Stud arc welding is widely used in the construction industry. For welding of studs with a diameter larger than 14 mm a ceramic ferrule is usually necessary in order to protect the weld pool. Disadvantages of using such a ferrule are that more metal is molten than necessary for a high quality welded joint and that the ferrule is a consumable generally thrown away after the welding operation. Investigations show that the ferrule can be omitted when the welding is carried out in a radially symmetric magnetic field within a shielding gas atmosphere. Due to the Lorentz force the arc is laterally shifted so that a very uniform and controlled melting of the stud contact surface as well as of the work piece can be achieved. In this paper a simplified physical model is presented describing how the parameters welding current, flux density of the magnetic field, radius of the arc and mass density of the shielding gas influence the velocity of the arc motion. The resulting equation is subsequently verified by comparing it to optical measurements of the arc motion. The proposed model can be used to optimize the required field distribution for the magnetic field stud welding process

Leaching of chromated copper arsenate (CCA)-treated wood in a simulated monofill and its potential impacts to landfill leachate

Energy Technology Data Exchange (ETDEWEB)

Jambeck, Jenna R. [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States); Townsend, Timothy [Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL 32611-6450 (United States)]. E-mail: ttown@ufl.edu; Solo-Gabriele, Helena [Department of Civil, Architectural, and Environmental Engineering, University of Miami, Coral Gables, FL 33146-0630 (United States)

2006-07-31

The proper end-of-life management of chromated copper arsenate (CCA)-treated wood, which contains arsenic, copper, and chromium, is a concern to the solid waste management community. Landfills are often the final repository of this waste stream, and the impacts of CCA preservative metals on leachate quality are not well understood. Monofills are a type of landfill designed and operated to dispose a single waste type, such as ash, tires, mining waste, or wood. The feasibility of managing CCA-treated wood in monofills was examined using a simulated landfill (a leaching lysimeter) that contained a mix of new and weathered CCA-treated wood. The liquid to solid ratio (LS) reached in the experiment was 0.63:1. Arsenic, chromium, and copper leached from the lysimeter at average concentrations of 42 mg/L for arsenic, 9.4 mg/L for chromium, and 2.4 mg/L for copper. Complementary batch leaching studies using deionized water were performed on similar CCA-treated wood samples at LS of 5:1 and 10:1. When results from the lysimeter were compared to the batch test results, copper and chromium leachability appeared to be reduced in the lysimeter disposal environment. Of the three metals, arsenic leached to the greatest extent and was found to have the best correlation between the batch and the lysimeter experiments.

Effects of increased temperature and CO{sub 2} on soil quality

Energy Technology Data Exchange (ETDEWEB)

Ogner, G.

1996-03-01

This paper was read at the workshop ``The Norwegian Climate and Ozone Research Programme`` held on 11-12 March 1996. The Norwegian Forest Research Institute has studied the effects of increased CO{sub 2} and temperature on forest soil, soil leachate and plants in an open top chamber experiment. The purpose was to analyze the changes in soil parameters and the leaching of elements. Nitrate and aluminium received special attention. The growth of Norway spruce and birch was followed, and its impact on the soil parameters. Preliminary results indicate that the temperature increase of the soil and consequently an increased turnover of soil organic matter had the major effect on the quality of soil leachates. CO{sub 2} was less important. Leaching of NO{sub 3}{sup -} was high from control lysimeters with moss cover. Lysimeters with birch hardly leached NO{sub 3}{sup -} at all. Spruce is in an intermediate position. Increased leaching of Al{sup n+} is found for moss lysimeters. Leachates from birch lysimeters have high concentrations of Al{sup n+} only at the end of the growth seasons. Plant growth is to some extent increased by the CO{sub 2} treatment. Birch grew well in all lysimeters and all treatments, spruce developed clear symptoms of stress. This result does not fit with the increased availability of nutrients in soil solution

Experimental Investigation of Properties of Foam Concrete for Industrial Floors in Testing Field

Science.gov (United States)

Vlcek, Jozef; Drusa, Marian; Scherfel, Walter; Sedlar, Bronislav

2017-12-01

Foam concrete (FC), as a mixture of cement, water, additives and technical foam, is well known for more than 30 years. It is building material with good mechanical properties, low thermal conductivity, simple and even high technological treatment. Foam concrete contains closed void pores, what allows achieving low bulk density and spare of raw materials. Thanks to its properties, it is usable as a replacement of conventional subbase layers of the industrial floors, the transport areas or as a part of the foundation structures of the buildings. Paper presents the preparation of the testing field (physical model) which was created for experimental investigation of the foam concrete subbase layer of the industrial floor in a real scale.

Field site investigation: Effect of mine seismicity on groundwater hydrology

International Nuclear Information System (INIS)

Ofoegbu, G.I.; Hsiung, S.; Chowdhury, A.H.

1995-04-01

The results of a field investigation on the groundwater-hydrologic effect of mining-induced earthquakes are presented in this report. The investigation was conducted at the Lucky Friday Mine, a silver-lead-zinc mine in the Coeur d'Alene Mining District of Idaho. The groundwater pressure in sections of three fracture zones beneath the water table was monitored over a 24-mo period. The fracture zones were accessed through a 360-m-long inclined borehole, drilled from the 5,700 level station of the mine. The magnitude, source location, and associated ground motions of mining-induced seismic events were also monitored during the same period, using an existing seismic instrumentation network for the mine, augmented with additional instruments installed specifically for the project by the center for Nuclear Waste Regulatory Analyses (CNWRA). More than 50 seismic events of Richter magnitude 1.0 or larger occurred during the monitoring period. Several of these events caused the groundwater pressure to increase, whereas a few caused it to decrease. Generally, the groundwater pressure increased as the magnitude of seismic event increased; for an event of a given magnitude, the groundwater pressure increased by a smaller amount as the distance of the observation point from the source of the event increased. The data was examined using regression analysis. Based on these results, it is suggested that the effect of earthquakes on groundwater flow may be better understood through mechanistic modeling. The mechanical processes and material behavior that would need to be incorporated in such a model are examined. They include a description of the effect of stress change on the permeability and water storage capacity of a fracture rock mass; transient fluid flow; and the generation and transmission of seismic waves through the rock mass

Investigation of the electric field in irradiated diamond sensors

Energy Technology Data Exchange (ETDEWEB)

Kassel, Florian; Barvich, Tobias; Boer, Wim de; Dierlamm, Alexander; Eber, Robert; Nuernberg, Andreas; Steck, Pia [Institut fuer Experimentelle Kernphysik (IEKP), Karlsruher Institut fuer Technologie (KIT) (Germany); Dabrowski, Anne; Guthoff, Moritz [CERN (Switzerland)

2015-07-01

The Beam Condition Monitoring Leakage (BCML) system is a beam monitoring device in the CMS experiment at the LHC. As detectors 32 poly-crystalline CVD diamond sensors are positioned in a ring around the beam pipe at a distance of +/-1.8 m and +/-14.4 m from the interaction point. The radiation hardness of the diamond sensors in terms of measured signal during operation was significantly lower than expected based on laboratory measurements. At high particle rates, like they occur during the operation of the LHC, charge carriers can be trapped in defects created by radiation. This space charge is expected to modify the electrical field in the sensor bulk and hence to reduce the charge collection efficiency. This modified electrical field has been indirectly measured in the laboratory using the Transient Current Technique (TCT) method in irradiated single crystal CVD diamond. This rate dependent effect was simulated with the software 'SILVACO ATLAS' and the obtained electrical field was used to calculate a TCT measurement pulse. The results of the TCT measurements will be compared to the simulation.

Effect of synthesis parameters on morphology of polyaniline (PANI) and field emission investigation of PANI nanotubes

Energy Technology Data Exchange (ETDEWEB)

Bankar, Prashant K.; More, Mahendra A., E-mail: mam@physics.unipune.ac.in [Center for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune-411007 (India); Patil, Sandip S. [Department of Physics, Modern College of Arts, Science and Commerce, Shivajinagar, Pune-411005. India (India)

2015-06-24

Polyaniline (PANI) nanostructures have been synthesized by simple chemical oxidation route at different monomer concentration along with variation in synthesis temperature. The effect of variation of synthesis parameters has been revealed using different characterization techniques. The structural and morphological characterization of the synthesized PANI nanostructures was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), whereas Fourier Transform Infrared spectroscopy (FTIR) has been used to reveal the chemical properties. With the variation in the synthesis temperature and monomer concentration, various morphologies characterized by formation of PANI nanoparticles, nanofibres, nanotubes and nanospheres, are revealed from the SEM analysis. The FTIR analysis reveals the formation of conducting state of PANI under prevailing experimental conditions. The field emission investigation of the conducting PANI nanotubes was performed in all metal UHV system at base pressure of 1x10{sup −8} mbar. The turn on field required to draw emission of 1 nA current was observed to be ∼ 2.2 V/μm and threshold field (corresponding to emission current density of 1 µA/cm2) was found to be 3.2 V/μm. The emission current was observed to be stable for more than three hours at a preset value 1 µA. The simple synthesis route and good field emission characteristics indicate potential of PANI nanofibres as a promising emitter for field emission based micro/nano devices.

Investigation of Oriented Magnetic Field Effects on Entropy Generation in an Inclined Channel Filled with Ferrofluids

Directory of Open Access Journals (Sweden)

Elgiz Baskaya

2017-07-01

Full Text Available Dispersion of super-paramagnetic nanoparticles in nonmagnetic carrier fluids, known as ferrofluids, offers the advantages of tunable thermo-physical properties and eliminate the need for moving parts to induce flow. This study investigates ferrofluid flow characteristics in an inclined channel under inclined magnetic field and constant pressure gradient. The ferrofluid considered in this work is comprised of Cu particles as the nanoparticles and water as the base fluid. The governing differential equations including viscous dissipation are non-dimensionalised and discretized with Generalized Differential Quadrature Method. The resulting algebraic set of equations are solved via Newton-Raphson Method. The work done here contributes to the literature by searching the effects of magnetic field angle and channel inclination separately on the entropy generation of the ferrofluid filled inclined channel system in order to achieve best design parameter values so called entropy generation minimization is implemented. Furthermore, the effect of magnetic field, inclination angle of the channel and volume fraction of nanoparticles on velocity and temperature profiles are examined and represented by figures to give a thorough understanding of the system behavior.

EIS Field Investigation in an Archaeological Site

DEFF Research Database (Denmark)

Hilbert, Lisbeth Rischel

2000-01-01

and metal objects. The area has been anaerobic and the corrosion rate has been very low for the metal objects to be preserved for so long, but it is now a major concern, whether the artefacts will further on be preserved in the area or will now corrode away. The National Museum is now monitoring...... measurements, electrical resistance corrosion rate measurements and weight loss data from the initial 15 months exposure will be presented and discussed as well as some practical aspects of field monitoring....

Site investigations for the disposal of spent fuel - investigation program

International Nuclear Information System (INIS)

Aeikaes, Timo

1985-11-01

The Industrial Power Company Ltd (TVO) is making preparations for the final disposal of spent nuclear fuel into the Finnish bedrock. The revised site investigation program for the years 1986-2010 is presented in this report. The objectives and activities in the near future are described in more detail. The main objectives and frame programs for the investigations in the more distant future are described. The program planning of these investigations are being developed in the preceding site investigations. The investigations for the site selection are divided into four phases: 1983-1985 selection of the investigation areas, preparations for the field investigations, drilling and investigations in a deep test borehole; 1986-1992 preliminary site investigations in 5-10 investigation areas; 1993-2000 detailed site investigations in 2-3 investigation areas. Site selection in the year 2000; 2001-2010 complementary investigations on the selected site. The first investigation phase will be carried out as planned. In this phase a 1001 m deep test borehole was drilled at Lavia in western Finland. With the investigations in the borehole and related development work, preparations were made for the future field investigations. The equipment and investigation methods are being developed during the site investigations. The equipment for taking groundwater samples and the unit for hydraulic testing have been developed. In the future the emphasis in the work will be in developing equipment for monitoring of the hydraulic head and measuring the volumetric flow. In groundwater sampling the present procedure can be improved by adding the test for the in-situ measurements. The results of the field investigations will be stored and processed in a centralized data base. The data base will transmit the results for the interpretation and then the interpreted results transmitted for model calculations and reporting. The cost estimate for the investigations in 1986-2010 is 110-125 million

An evaluation of SEBAL algorithm using high resolution aircraft data acquired during BEAREX07

Science.gov (United States)

Paul, G.; Gowda, P. H.; Prasad, V. P.; Howell, T. A.; Staggenborg, S.

2010-12-01

Surface Energy Balance Algorithm for Land (SEBAL) computes spatially distributed surface energy fluxes and evapotranspiration (ET) rates using a combination of empirical and deterministic equations executed in a strictly hierarchical sequence. Over the past decade SEBAL has been tested over various regions and has found its application in solving water resources and irrigation problems. This research combines high resolution remote sensing data and field measurements of the surface radiation and agro-meteorological variables to review various SEBAL steps for mapping ET in the Texas High Plains (THP). High resolution aircraft images (0.5-1.8 m) acquired during the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment 2007 (BEAREX07) conducted at the USDA-ARS Conservation and Production Research Laboratory in Bushland, Texas, was utilized to evaluate the SEBAL. Accuracy of individual relationships and predicted ET were investigated using observed hourly ET rates from 4 large weighing lysimeters, each located at the center of 4.7 ha field. The uniqueness and the strength of this study come from the fact that it evaluates the SEBAL for irrigated and dryland conditions simultaneously with each lysimeter field planted to irrigated forage sorghum, irrigated forage corn, dryland clumped grain sorghum, and dryland row sorghum. Improved coefficients for the local conditions were developed for the computation of roughness length for momentum transport. The decision involved in selection of dry and wet pixels, which essentially determines the partitioning of the available energy between sensible (H) and latent (LE) heat fluxes has been discussed. The difference in roughness length referred to as the kB-1 parameter was modified in the current study. Performance of the SEBAL was evaluated using mean bias error (MBE) and root mean square error (RMSE). An RMSE of ±37.68 W m-2 and ±0.11 mm h-1 was observed for the net radiation and hourly actual ET, respectively

Numerical investigation on splitting of ferrofluid microdroplets in T-junctions using an asymmetric magnetic field with proposed correlation

Science.gov (United States)

Aboutalebi, Mohammad; Bijarchi, Mohamad Ali; Shafii, Mohammad Behshad; Kazemzadeh Hannani, Siamak

2018-02-01

The studies surrounding the concept of microdroplets have seen a dramatic increase in recent years. Microdroplets have applications in different fields such as chemical synthesis, biology, separation processes and micro-pumps. This study numerically investigates the effect of different parameters such as Capillary number, Length of droplets, and Magnetic Bond number on the splitting process of ferrofluid microdroplets in symmetric T-junctions using an asymmetric magnetic field. The use of said field that is applied asymmetrically to the T-junction center helps us control the splitting of ferrofluid microdroplets. During the process of numerical simulation, a magnetic field with various strengths from a dipole located at a constant distance from the center of the T-junction was applied. The main advantage of this design is its control over the splitting ratio of daughter droplets and reaching various microdroplet sizes in a T-junction by adjusting the magnetic field strength. The results showed that by increasing the strength of the magnetic field, the possibility of asymmetric splitting of microdroplets increases in a way that for high values of field strength, high splitting ratios can be reached. Also, by using the obtained results at various Magnetic Bond numbers and performing curve fitting, a correlation is derived that can be used to accurately predict the borderline between splitting and non-splitting zones of microdroplets flow in micro T-junctions.

Effect of gamma-irradiation on cereal DNA investigated by pulsed-field gel electrophoresis

International Nuclear Information System (INIS)